Diff for /loncom/lond between versions 1.178.2.3 and 1.224

version 1.178.2.3, 2004/02/24 11:22:41 version 1.224, 2004/08/06 10:27:53
Line 20 Line 20
 #  #
 # You should have received a copy of the GNU General Public License  # You should have received a copy of the GNU General Public License
 # along with LON-CAPA; if not, write to the Free Software  # along with LON-CAPA; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA      # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 #  #
 # /home/httpd/html/adm/gpl.txt  # /home/httpd/html/adm/gpl.txt
 #  #
Line 45  use Authen::Krb4; Line 45  use Authen::Krb4;
 use Authen::Krb5;  use Authen::Krb5;
 use lib '/home/httpd/lib/perl/';  use lib '/home/httpd/lib/perl/';
 use localauth;  use localauth;
   use localenroll;
 use File::Copy;  use File::Copy;
 use LONCAPA::ConfigFileEdit;  use LONCAPA::ConfigFileEdit;
   use LONCAPA::lonlocal;
   use LONCAPA::lonssl;
   use Fcntl qw(:flock);
   
 my $DEBUG = 1;       # Non zero to enable debug log entries.  my $DEBUG = 1;       # Non zero to enable debug log entries.
   
Line 55  my $lastlog=''; Line 59  my $lastlog='';
   
 my $VERSION='$Revision$'; #' stupid emacs  my $VERSION='$Revision$'; #' stupid emacs
 my $remoteVERSION;  my $remoteVERSION;
 my $currenthostid;  my $currenthostid="default";
 my $currentdomainid;  my $currentdomainid;
   
 my $client;  my $client;
 my $clientip;  my $clientip; # IP address of client.
 my $clientname;  my $clientdns; # DNS name of client.
   my $clientname; # LonCAPA name of client.
 my $cipher; # Cipher key negotiated with client.  
 my $tmpsnum = 0;; # Id of tmpputs.  
   
 my $server;  my $server;
 my $thisserver;  my $thisserver; # DNS of us.
   
   my $keymode;
   
   my $cipher; # Cipher key negotiated with client
   my $tmpsnum = 0; # Id of tmpputs.
   
 #   # 
 #   Connection type is:  #   Connection type is:
Line 77  my $thisserver; Line 84  my $thisserver;
   
 my $ConnectionType;  my $ConnectionType;
   
 my %hostid;  my %hostid; # ID's for hosts in cluster by ip.
 my %hostdom;  my %hostdom; # LonCAPA domain for hosts in cluster.
 my %hostip;  my %hostip; # IPs for hosts in cluster.
   my %hostdns; # ID's of hosts looked up by DNS name.
   
 my %managers; # Ip -> manager names  my %managers; # Ip -> manager names
   
Line 98  my $CLIENT_OK  = 1; Line 106  my $CLIENT_OK  = 1;
 my $MANAGER_OK = 2;  my $MANAGER_OK = 2;
 my %Dispatcher;  my %Dispatcher;
   
   
 #  #
 #  The array below are password error strings."  #  The array below are password error strings."
 #  #
Line 113  my @passwderrors = ("ok", Line 122  my @passwderrors = ("ok",
    "lcpasswd Cannot set new passwd.",     "lcpasswd Cannot set new passwd.",
    "lcpasswd Username has invalid characters",     "lcpasswd Username has invalid characters",
    "lcpasswd Invalid characters in password",     "lcpasswd Invalid characters in password",
     "11", "12",     "lcpasswd User already exists", 
     "lcpasswd Password mismatch");                     "lcpasswd Something went wrong with user addition.",
       "lcpasswd Password mismatch",
       "lcpasswd Error filename is invalid");
   
   
 #  The array below are lcuseradd error strings.:  #  The array below are lcuseradd error strings.:
Line 135  my @adderrors    = ("ok", Line 146  my @adderrors    = ("ok",
     "lcuseradd Could not add user.",      "lcuseradd Could not add user.",
     "lcuseradd Password mismatch");      "lcuseradd Password mismatch");
   
   
   
 #  #
 #   Statistics that are maintained and dislayed in the status line.  #   Statistics that are maintained and dislayed in the status line.
 #  #
 my $Transactions; # Number of attempted transactions.  my $Transactions = 0; # Number of attempted transactions.
 my $Failures; # Number of transcations failed.  my $Failures     = 0; # Number of transcations failed.
   
 #   ResetStatistics:   #   ResetStatistics: 
 #      Resets the statistics counters:  #      Resets the statistics counters:
Line 149  sub ResetStatistics { Line 162  sub ResetStatistics {
     $Failures     = 0;      $Failures     = 0;
 }  }
   
 #  
 #   Return true if client is a manager.  
 #  
 sub isManager {  
     return (($ConnectionType eq "manager") || ($ConnectionType eq "both"));  
 }  
 #  
 #   Return tru if client can do client functions  
 #  
 sub isClient {  
     return (($ConnectionType eq "client") || ($ConnectionType eq "both"));  
 }  
   
   
   #------------------------------------------------------------------------
 #  #
 #   Get a Request:  #   LocalConnection
 #   Gets a Request message from the client.  The transaction  #     Completes the formation of a locally authenticated connection.
 #   is defined as a 'line' of text.  We remove the new line  #     This function will ensure that the 'remote' client is really the
 #   from the text line.    #     local host.  If not, the connection is closed, and the function fails.
 #     #     If so, initcmd is parsed for the name of a file containing the
 sub GetRequest {  #     IDEA session key.  The fie is opened, read, deleted and the session
     my $input = <$client>;  #     key returned to the caller.
     chomp($input);  
   
     Debug("Request = $input\n");  
   
     &status('Processing '.$clientname.':'.$input);  
   
     return $input;  
 }  
 #  
 #   Decipher encoded traffic  
 #  Parameters:  
 #     input      - Encoded data.  
 #  Returns:  
 #     Decoded data or undef if encryption key was not yet negotiated.  
 #  Implicit input:  
 #     cipher  - This global holds the negotiated encryption key.  
 #  
 sub Decipher {  
    my $input  = shift;  
    my $output = '';  
      
      
    if($cipher) {  
       my($enc, $enclength, $encinput) = split(/:/, $input);  
       for(my $encidx = 0; $encidx < length($encinput); $encidx += 16) {  
          $output .=   
             $cipher->decrypt(pack("H16", substr($encinput, $encidx, 16)));  
       }  
       return substr($output, 0, $enclength);  
    } else {  
       return undef;  
    }  
      
 }  
   
 #  #
 #   Register a command processor.  This function is invoked to register a sub  
 #   to process a request.  Once registered, the ProcessRequest sub can automatically  
 #   dispatch requests to an appropriate sub, and do the top level validity checking  
 #   as well:  
 #    - Is the keyword recognized.  
 #    - Is the proper client type attempting the request.  
 #    - Is the request encrypted if it has to be.  
 #   Parameters:  
 #    $RequestName         - Name of the request being registered.  
 #                           This is the command request that will match  
 #                           against the hash keywords to lookup the information  
 #                           associated with the dispatch information.  
 #    $Procedure           - Reference to a sub to call to process the request.  
 #                           All subs get called as follows:  
 #                             Procedure($cmd, $tail, $replyfd, $key)  
 #                             $cmd    - the actual keyword that invoked us.  
 #                             $tail   - the tail of the request that invoked us.  
 #                             $replyfd- File descriptor connected to the client  
 #    $MustEncode          - True if the request must be encoded to be good.  
 #    $ClientOk            - True if it's ok for a client to request this.  
 #    $ManagerOk           - True if it's ok for a manager to request this.  
 # Side effects:  
 #      - On success, the Dispatcher hash has an entry added for the key $RequestName  
 #      - On failure, the program will die as it's a bad internal bug to try to   
 #        register a duplicate command handler.  
 #  
 sub RegisterHandler {  
    my $RequestName    = shift;  
    my $Procedure      = shift;  
    my $MustEncode     = shift;  
    my $ClientOk       = shift;  
    my $ManagerOk      = shift;  
      
    #  Don't allow duplication#  
      
    if (defined $Dispatcher{$RequestName}) {  
       die "Attempting to define a duplicate request handler for $RequestName\n";  
    }  
    #   Build the client type mask:  
      
    my $ClientTypeMask = 0;  
    if($ClientOk) {  
       $ClientTypeMask  |= $CLIENT_OK;  
    }  
    if($ManagerOk) {  
       $ClientTypeMask  |= $MANAGER_OK;  
    }  
      
    #  Enter the hash:  
         
    my @entry = ($Procedure, $MustEncode, $ClientTypeMask);  
      
    $Dispatcher{$RequestName} = \@entry;  
      
      
 }  
   
 #--------------------- Request Handlers --------------------------------------------  
 #  
 #   By convention each request handler registers itself prior to the sub declaration:  
 #  
   
 #  Handles ping requests.  
 #  Parameters:  
 #      $cmd    - the actual keyword that invoked us.  
 #      $tail   - the tail of the request that invoked us.  
 #      $replyfd- File descriptor connected to the client  
 #  Implicit Inputs:  
 #      $currenthostid - Global variable that carries the name of the host we are  
 #                       known as.  
 #  Returns:  
 #      1       - Ok to continue processing.  
 #      0       - Program should exit.  
 #  Side effects:  
 #      Reply information is sent to the client.  
   
 sub PingHandler {  
    my $cmd    = shift;  
    my $tail   = shift;  
    my $client = shift;  
      
    Reply( $client,"$currenthostid\n","$cmd:$tail");  
      
    return 1;  
 }  
 RegisterHandler("ping", \&PingHandler, 0, 1, 1);       # Ping unencoded, client or manager.  
 #  
 # Handles pong reequests:  
 # Parameters:  # Parameters:
 #      $cmd    - the actual keyword that invoked us.  #   $Socket      - Socket open on client.
 #      $tail   - the tail of the request that invoked us.  #   $initcmd     - The full text of the init command.
 #      $replyfd- File descriptor connected to the client  
 #  Implicit Inputs:  
 #      $currenthostid - Global variable that carries the name of the host we are  
 #                       connected to.  
 #  Returns:  
 #      1       - Ok to continue processing.  
 #      0       - Program should exit.  
 #  Side effects:  
 #      Reply information is sent to the client.  
   
 sub PongHandler {  
    my $cmd     = shift;  
    my $tail    = shift;  
    my $replyfd = shift;  
   
    my $reply=&reply("ping",$clientname);  
    Reply( $replyfd, "$currenthostid:$reply\n", "$cmd:$tail");   
    return 1;  
 }  
 RegisterHandler("pong", \&PongHandler, 0, 1, 1);       # Pong unencoded, client or manager  
   
 #  
 #   EstablishKeyHandler:  
 #      Called to establish an encrypted session key with the remote client.  
 #  
 # Parameters:  
 #      $cmd    - the actual keyword that invoked us.  
 #      $tail   - the tail of the request that invoked us.  
 #      $replyfd- File descriptor connected to the client  
 #  Implicit Inputs:  
 #      $currenthostid - Global variable that carries the name of the host  
 #                       known as.  
 #      $clientname    - Global variable that carries the name of the hsot we're connected to.  
 #  Returns:  
 #      1       - Ok to continue processing.  
 #      0       - Program should exit.  
 #  Implicit Outputs:  
 #      Reply information is sent to the client.  
 #      $cipher is set with a reference to a new IDEA encryption object.  
 #  
 sub EstablishKeyHandler {  
    my $cmd      = shift;  
    my $tail     = shift;  
    my $replyfd  = shift;  
   
    my $buildkey=time.$$.int(rand 100000);  
    $buildkey=~tr/1-6/A-F/;  
    $buildkey=int(rand 100000).$buildkey.int(rand 100000);  
    my $key=$currenthostid.$clientname;  
    $key=~tr/a-z/A-Z/;  
    $key=~tr/G-P/0-9/;  
    $key=~tr/Q-Z/0-9/;  
    $key=$key.$buildkey.$key.$buildkey.$key.$buildkey;  
    $key=substr($key,0,32);  
    my $cipherkey=pack("H32",$key);  
    $cipher=new IDEA $cipherkey;  
    Reply($replyfd, "$buildkey\n", "$cmd:$tail");   
      
    return 1;  
   
 }  
 RegisterHandler("ekey", \&EstablishKeyHandler, 0, 1,1);  
   
 #  LoadHandler:  
 #     Handler for the load command.  Returns the current system load average  
 #     to the requestor.  
 #  
 # Parameters:  
 #      $cmd    - the actual keyword that invoked us.  
 #      $tail   - the tail of the request that invoked us.  
 #      $replyfd- File descriptor connected to the client  
 #  Implicit Inputs:  
 #      $currenthostid - Global variable that carries the name of the host  
 #                       known as.  
 #      $clientname    - Global variable that carries the name of the hsot we're connected to.  
 #  Returns:  
 #      1       - Ok to continue processing.  
 #      0       - Program should exit.  
 #  Side effects:  
 #      Reply information is sent to the client.  
 sub LoadHandler {  
    my $cmd     = shift;  
    my $tail    = shift;  
    my $replyfd = shift;  
   
    # Get the load average from /proc/loadavg and calculate it as a percentage of  
    # the allowed load limit as set by the perl global variable lonLoadLim  
   
    my $loadavg;  
    my $loadfile=IO::File->new('/proc/loadavg');  
      
    $loadavg=<$loadfile>;  
    $loadavg =~ s/\s.*//g;                       # Extract the first field only.  
      
    my $loadpercent=100*$loadavg/$perlvar{'lonLoadLim'};  
   
    Reply( $replyfd, "$loadpercent\n", "$cmd:$tail");  
      
    return 1;  
 }  
 RegisterHandler("load", \&LoadHandler, 0, 1, 0);  
   
   
 #  
 #   Process the userload request.  This sub returns to the client the current  
 #  user load average.  It can be invoked either by clients or managers.  
 #  #
 # Parameters:  
 #      $cmd    - the actual keyword that invoked us.  
 #      $tail   - the tail of the request that invoked us.  
 #      $replyfd- File descriptor connected to the client  
 #  Implicit Inputs:  
 #      $currenthostid - Global variable that carries the name of the host  
 #                       known as.  
 #      $clientname    - Global variable that carries the name of the hsot we're connected to.  
 #  Returns:  
 #      1       - Ok to continue processing.  
 #      0       - Program should exit  
 # Implicit inputs:  # Implicit inputs:
 #     whatever the userload() function requires.  #    $clientdns  - The DNS name of the remote client.
 #  Implicit outputs:  #    $thisserver - Our DNS name.
 #     the reply is written to the client.  
 #  
 sub UserLoadHandler {  
    my $cmd     = shift;  
    my $tail    = shift;  
    my $replyfd = shift;  
   
    my $userloadpercent=&userload();  
    Reply($replyfd, "$userloadpercent\n", "$cmd:$tail");  
   
    return 1;  
 }  
 RegisterHandler("userload", \&UserLoadHandler, 0, 1, 0);  
   
 #   Process a request for the authorization type of a user:  
 #   (userauth).  
 #  
 # Parameters:  
 #      $cmd    - the actual keyword that invoked us.  
 #      $tail   - the tail of the request that invoked us.  
 #      $replyfd- File descriptor connected to the client  
 #  Returns:  
 #      1       - Ok to continue processing.  
 #      0       - Program should exit  
 # Implicit outputs:  
 #    The user authorization type is written to the client.  
 #  
 sub UserAuthorizationType {  
    my $cmd     = shift;  
    my $tail    = shift;  
    my $replyfd = shift;  
      
    my $userinput = "$cmd:$tail";  
      
    #  Pull the domain and username out of the command tail.  
    # and call GetAuthType to determine the authentication type.  
      
    my ($udom,$uname)=split(/:/,$tail);  
    my $result = GetAuthType($udom, $uname);  
    if($result eq "nouser") {  
       Failure( $replyfd, "unknown_user\n", $userinput);  
    } else {  
       Reply( $replyfd, "$result\n", $userinput);  
    }  
     
    return 1;  
 }  
 RegisterHandler("currentauth", \&UserAuthorizationType, 1, 1, 0);  
 #  
 #   Process a request by a manager to push a hosts or domain table   
 #   to us.  We pick apart the command and pass it on to the subs  
 #   that already exist to do this.  
 #  
 # Parameters:  
 #      $cmd    - the actual keyword that invoked us.  
 #      $tail   - the tail of the request that invoked us.  
 #      $client - File descriptor connected to the client  
 #  Returns:  
 #      1       - Ok to continue processing.  
 #      0       - Program should exit  
 # Implicit Output:  
 #    a reply is written to the client.  
   
 sub PushFileHandler {  
    my $cmd    = shift;  
    my $tail   = shift;  
    my $client = shift;  
   
    my $userinput = "$cmd:$tail";  
   
    # At this time we only know that the IP of our partner is a valid manager  
    # the code below is a hook to do further authentication (e.g. to resolve  
    # spoofing).  
   
    my $cert = GetCertificate($userinput);  
    if(ValidManager($cert)) {   
   
       # Now presumably we have the bona fides of both the peer host and the  
       # process making the request.  
         
       my $reply = PushFile($userinput);  
       Reply($client, "$reply\n", $userinput);  
   
    } else {  
       Failure( $client, "refused\n", $userinput);  
    }   
 }  
 RegisterHandler("pushfile", \&PushFileHandler, 1, 0, 1);  
   
   
   
 #   Process a reinit request.  Reinit requests that either  
 #   lonc or lond be reinitialized so that an updated   
 #   host.tab or domain.tab can be processed.  
 #  
 # Parameters:  
 #      $cmd    - the actual keyword that invoked us.  
 #      $tail   - the tail of the request that invoked us.  
 #      $client - File descriptor connected to the client  
 #  Returns:  
 #      1       - Ok to continue processing.  
 #      0       - Program should exit  
 #  Implicit output:  
 #     a reply is sent to the client.  
 #  
 sub ReinitProcessHandler {  
    my $cmd    = shift;  
    my $tail   = shift;  
    my $client = shift;  
      
    my $userinput = "$cmd:$tail";  
      
    my $cert = GetCertificate($userinput);  
    if(ValidManager($cert)) {  
       chomp($userinput);  
       my $reply = ReinitProcess($userinput);  
       Reply( $client,  "$reply\n", $userinput);  
    } else {  
       Failure( $client, "refused\n", $userinput);  
  }  
    return 1;  
 }  
   
 RegisterHandler("reinit", \&ReinitProcessHandler, 1, 0, 1);  
   
 #  Process the editing script for a table edit operation.  
 #  the editing operation must be encrypted and requested by  
 #  a manager host.  
 #  
 # Parameters:  
 #      $cmd    - the actual keyword that invoked us.  
 #      $tail   - the tail of the request that invoked us.  
 #      $client - File descriptor connected to the client  
 #  Returns:  
 #      1       - Ok to continue processing.  
 #      0       - Program should exit  
 #  Implicit output:  
 #     a reply is sent to the client.  
 #  
 sub EditTableHandler {  
    my $command    = shift;  
    my $tail       = shift;  
    my $client     = shift;  
      
    my $userinput = "$command:$tail";  
   
    my $cert = GetCertificate($userinput);  
    if(ValidManager($cert)) {  
       my($filetype, $script) = split(/:/, $tail);  
       if (($filetype eq "hosts") ||   
           ($filetype eq "domain")) {  
          if($script ne "") {  
             Reply($client,            # BUGBUG - EditFile  
                   EditFile($userinput), #   could fail.  
                   $userinput);  
          } else {  
             Failure($client,"refused\n",$userinput);  
          }  
       } else {  
          Failure($client,"refused\n",$userinput);  
       }  
    } else {  
       Failure($client,"refused\n",$userinput);  
    }  
    return 1;  
 }  
 RegisterHandler("edit", \&EditTableHandler, 1, 0, 1);  
   
   
 #  
 #   Authenticate a user against the LonCAPA authentication  
 #   database.  Note that there are several authentication  
 #   possibilities:  
 #   - unix     - The user can be authenticated against the unix  
 #                password file.  
 #   - internal - The user can be authenticated against a purely   
 #                internal per user password file.  
 #   - kerberos - The user can be authenticated against either a kerb4 or kerb5  
 #                ticket granting authority.  
 #   - user     - The person tailoring LonCAPA can supply a user authentication mechanism  
 #                that is per system.  
 #  
 # Parameters:  
 #    $cmd      - The command that got us here.  
 #    $tail     - Tail of the command (remaining parameters).  
 #    $client   - File descriptor connected to client.  
 # Returns  
 #     0        - Requested to exit, caller should shut down.  
 #     1        - Continue processing.  
 # Implicit inputs:  
 #    The authentication systems describe above have their own forms of implicit  
 #    input into the authentication process that are described above.  
 #  
 sub AuthenticateHandler {  
    my $cmd        = shift;  
    my $tail       = shift;  
    my $client     = shift;  
      
    #  Regenerate the full input line   
      
    my $userinput  = $cmd.":".$tail;  
   
    #  udom    - User's domain.  
    #  uname   - Username.  
    #  upass   - User's password.  
      
    my ($udom,$uname,$upass)=split(/:/,$tail);  
    Debug(" Authenticate domain = $udom, user = $uname, password = $upass");  
    chomp($upass);  
    $upass=unescape($upass);  
    my $proname=propath($udom,$uname);  
    my $passfilename="$proname/passwd";  
      
    #   The user's 'personal' loncapa passworrd file describes how to authenticate:  
      
    if (-e $passfilename) {  
      Debug("Located password file: $passfilename");  
   
       my $pf = IO::File->new($passfilename);  
       my $realpasswd=<$pf>;  
       chomp($realpasswd);  
       my ($howpwd,$contentpwd)=split(/:/,$realpasswd);  
       my $pwdcorrect=0;  
       #  
       #   Authenticate against password stored in the internal file.  
       #  
      Debug("Authenticating via $howpwd");  
       if ($howpwd eq 'internal') {  
          &Debug("Internal auth");  
          $pwdcorrect= (crypt($upass,$contentpwd) eq $contentpwd);  
       #  
       #   Authenticate against the unix password file.  
       #  
       } elsif ($howpwd eq 'unix') {  
          &Debug("Unix auth");  
          if((getpwnam($uname))[1] eq "") { #no such user!  
             $pwdcorrect = 0;  
          } else {  
             $contentpwd=(getpwnam($uname))[1];  
             my $pwauth_path="/usr/local/sbin/pwauth";  
             unless ($contentpwd eq 'x') {  
                $pwdcorrect= (crypt($upass,$contentpwd) eq $contentpwd);  
             } elsif (-e $pwauth_path) {  
                open PWAUTH, "|$pwauth_path" or  
                   die "Cannot invoke authentication";  
                print PWAUTH "$uname\n$upass\n";  
                close PWAUTH;  
                $pwdcorrect=!$?;  
             }  
          }  
       #  
       #   Authenticate against a Kerberos 4 server:  
       #  
       } elsif ($howpwd eq 'krb4') {  
          my $null=pack("C",0);  
          unless ($upass=~/$null/) {  
             my $krb4_error = &Authen::Krb4::get_pw_in_tkt($uname,  
                                                           "",  
                                                           $contentpwd,  
                                                           'krbtgt',  
                                                          $contentpwd,  
                                                          1,  
                                                          $upass);  
             if (!$krb4_error) {  
                $pwdcorrect = 1;  
             } else {   
                $pwdcorrect=0;   
                # log error if it is not a bad password  
                if ($krb4_error != 62) {  
                   &logthis('krb4:'.$uname.','.$contentpwd.','.  
                            &Authen::Krb4::get_err_txt($Authen::Krb4::error));  
                }  
             }  
          }  
       #  
       #   Authenticate against a Kerberos 5 server:  
       #  
       } elsif ($howpwd eq 'krb5') {  
          my $null=pack("C",0);  
          unless ($upass=~/$null/) {  
             my $krbclient=&Authen::Krb5::parse_name($uname.'@'.$contentpwd);  
             my $krbservice="krbtgt/".$contentpwd."\@".$contentpwd;  
             my $krbserver=&Authen::Krb5::parse_name($krbservice);  
             my $credentials=&Authen::Krb5::cc_default();  
             $credentials->initialize($krbclient);  
             my $krbreturn = &Authen::Krb5::get_in_tkt_with_password(  
                                                                     $krbclient,  
                                                                     $krbserver,  
                                                                     $upass,  
                                                                     $credentials);  
             $pwdcorrect = ($krbreturn == 1);  
          } else {   
             $pwdcorrect=0;   
          }  
       #  
       #  Finally, the user may have written in an authentication module.  
       #  in that case, if requested, authenticate against it.  
       #  
       } elsif ($howpwd eq 'localauth') {  
          $pwdcorrect=&localauth::localauth($uname,$upass,$contentpwd);  
       }  
       #  
       #   Successfully authorized.  
       #  
       if ($pwdcorrect) {  
          Reply( $client, "authorized\n", $userinput);  
       #  
       #  Bad credentials: Failed to authorize  
       #  
       } else {  
          Failure( $client, "non_authorized\n", $userinput);  
       }  
    #  
    #  User bad... note it may be bad security practice to differntiate to the  
    #  caller a bad user from a  bad passwd... since that supplies covert channel  
    #  information (you have a good user but bad password e.g.) to guessers.  
    #  
    } else {  
       Failure( $client, "unknown_user\n", $userinput);  
    }  
    return 1;  
 }  
 RegisterHandler("auth", \&AuthenticateHandler, 1, 1, 0);  
   
 #  
 #   Change a user's password.  Note that this function is complicated by  
 #   the fact that a user may be authenticated in more than one way:  
 #   At present, we are not able to change the password for all types of  
 #   authentication methods.  Only for:  
 #      unix    - unix password or shadow passoword style authentication.  
 #      local   - Locally written authentication mechanism.  
 #   For now, kerb4 and kerb5 password changes are not supported and result  
 #   in an error.  
 # FUTURE WORK:  
 #    Support kerberos passwd changes?  
 # Parameters:  
 #    $cmd      - The command that got us here.  
 #    $tail     - Tail of the command (remaining parameters).  
 #    $client   - File descriptor connected to client.  
 # Returns  
 #     0        - Requested to exit, caller should shut down.  
 #     1        - Continue processing.  
 # Implicit inputs:  
 #    The authentication systems describe above have their own forms of implicit  
 #    input into the authentication process that are described above.  
 sub ChangePasswordHandler {  
    my $cmd     = shift;  
    my $tail    = shift;  
    my $client  = shift;  
      
    my $userinput = $cmd.":".$tail;           # Reconstruct client's string.  
   
    #  
    #  udom  - user's domain.  
    #  uname - Username.  
    #  upass - Current password.  
    #  npass - New password.  
      
    my ($udom,$uname,$upass,$npass)=split(/:/,$tail);  
    chomp($npass);  
    $upass=&unescape($upass);  
    $npass=&unescape($npass);  
    &Debug("Trying to change password for $uname");  
    my $proname=propath($udom,$uname);  
    my $passfilename="$proname/passwd";  
    if (-e $passfilename) {  
       my $realpasswd;  
       {   
          my $pf = IO::File->new($passfilename);  
          $realpasswd=<$pf>;   
       }  
       chomp($realpasswd);  
       my ($howpwd,$contentpwd)=split(/:/,$realpasswd);  
       if ($howpwd eq 'internal') {  
          &Debug("internal auth");  
          if (crypt($upass,$contentpwd) eq $contentpwd) {  
             my $salt=time;  
             $salt=substr($salt,6,2);  
             my $ncpass=crypt($npass,$salt);  
                {  
                   my $pf = IO::File->new(">$passfilename");  
                   if ($pf) {  
                      print $pf "internal:$ncpass\n";  
                      &logthis("Result of password change for "  
                               ."$uname: pwchange_success");  
                      Reply($client, "ok\n", $userinput);  
                   } else {  
                      &logthis("Unable to open $uname passwd "                 
                               ."to change password");  
                      Failure( $client, "non_authorized\n",$userinput);  
                   }  
                }               
          } else {  
             Failure($client, "non_authorized\n", $userinput);  
          }  
       } elsif ($howpwd eq 'unix') {  
          # Unix means we have to access /etc/password  
          # one way or another.  
          # First: Make sure the current password is  
          #        correct  
          &Debug("auth is unix");  
          $contentpwd=(getpwnam($uname))[1];  
          my $pwdcorrect = "0";  
          my $pwauth_path="/usr/local/sbin/pwauth";  
          unless ($contentpwd eq 'x') {  
             $pwdcorrect= (crypt($upass,$contentpwd) eq $contentpwd);  
          } elsif (-e $pwauth_path) {  
             open PWAUTH, "|$pwauth_path" or  
                die "Cannot invoke authentication";  
             print PWAUTH "$uname\n$upass\n";  
             close PWAUTH;  
             &Debug("exited pwauth with $? ($uname,$upass) ");  
             $pwdcorrect=($? == 0);  
          }  
          if ($pwdcorrect) {  
             my $execdir=$perlvar{'lonDaemons'};  
             &Debug("Opening lcpasswd pipeline");  
             my $pf = IO::File->new("|$execdir/lcpasswd > "  
                                     ."$perlvar{'lonDaemons'}"  
                                     ."/logs/lcpasswd.log");  
             print $pf "$uname\n$npass\n$npass\n";  
             close $pf;  
             my $err = $?;  
             my $result = ($err>0 ? 'pwchange_failure' : 'ok');  
             &logthis("Result of password change for $uname: ".  
             &lcpasswdstrerror($?));  
             Reply($client, "$result\n", $userinput);  
          } else {  
             Reply($client, "non_authorized\n", $userinput);  
          }  
       } else {  
          Reply( $client, "auth_mode_error\n", $userinput);  
       }    
    } else {  
             Reply( $client, "unknown_user\n", $userinput);  
    }  
    return 1;  
 }  
 RegisterHandler("passwd", \&ChangePasswordHandler, 1, 1, 0);  
   
 #  
 #   Create a new user.  User in this case means a lon-capa user.  
 #   The user must either already exist in some authentication realm  
 #   like kerberos or the /etc/passwd.  If not, a user completely local to  
 #   this loncapa system is created.  
 #  
 # Parameters:  
 #    $cmd      - The command that got us here.  
 #    $tail     - Tail of the command (remaining parameters).  
 #    $client   - File descriptor connected to client.  
 # Returns  
 #     0        - Requested to exit, caller should shut down.  
 #     1        - Continue processing.  
 # Implicit inputs:  
 #    The authentication systems describe above have their own forms of implicit  
 #    input into the authentication process that are described above.  
 sub AddUserHandler {  
    my $cmd     = shift;  
    my $tail    = shift;  
    my $client  = shift;  
      
    my $userinput = $cmd.":".$tail;     
   
    my $oldumask=umask(0077);  
    my ($udom,$uname,$umode,$npass)=split(/:/,$tail);  
    &Debug("cmd =".$cmd." $udom =".$udom." uname=".$uname);  
    chomp($npass);  
    $npass=&unescape($npass);  
    my $proname=propath($udom,$uname);  
    my $passfilename="$proname/passwd";  
    &Debug("Password file created will be:".$passfilename);  
    if (-e $passfilename) {  
       Failure( $client, "already_exists\n", $userinput);  
    } elsif ($udom ne $currentdomainid) {  
       Failure($client, "not_right_domain\n", $userinput);  
    } else {  
       my @fpparts=split(/\//,$proname);  
       my $fpnow=$fpparts[0].'/'.$fpparts[1].'/'.$fpparts[2];  
       my $fperror='';  
       for (my $i=3;$i<=$#fpparts;$i++) {  
          $fpnow.='/'.$fpparts[$i];   
          unless (-e $fpnow) {  
             unless (mkdir($fpnow,0777)) {  
                $fperror="error: ".($!+0)." mkdir failed while attempting "  
                        ."makeuser";  
             }  
          }  
       }  
       unless ($fperror) {  
          my $result=&make_passwd_file($uname, $umode,$npass, $passfilename);  
          Reply($client, $result, $userinput);     #BUGBUG - could be fail  
       } else {  
          Failure($client, "$fperror\n", $userinput);  
       }  
    }  
    umask($oldumask);  
    return 1;  
   
 }  
 RegisterHandler("makeuser", \&AddUserHandler, 1, 1, 0);  
   
 #  
 #   Change the authentication method of a user.  Note that this may  
 #   also implicitly change the user's password if, for example, the user is  
 #   joining an existing authentication realm.  Known authentication realms at  
 #   this time are:  
 #    internal   - Purely internal password file (only loncapa knows this user)  
 #    local      - Institutionally written authentication module.  
 #    unix       - Unix user (/etc/passwd with or without /etc/shadow).  
 #    kerb4      - kerberos version 4  
 #    kerb5      - kerberos version 5  
 #  
 # Parameters:  
 #    $cmd      - The command that got us here.  
 #    $tail     - Tail of the command (remaining parameters).  
 #    $client   - File descriptor connected to client.  
 # Returns  
 #     0        - Requested to exit, caller should shut down.  
 #     1        - Continue processing.  
 # Implicit inputs:  
 #    The authentication systems describe above have their own forms of implicit  
 #    input into the authentication process that are described above.  
 #  
 sub ChangeAuthenticationHandler {  
    my $cmd     = shift;  
    my $tail    = shift;  
    my $client  = shift;  
      
    my $userinput  = "$cmd:$tail";              # Reconstruct user input.  
   
    my ($udom,$uname,$umode,$npass)=split(/:/,$tail);  
    chomp($npass);  
    &Debug("cmd = ".$cmd." domain= ".$udom."uname =".$uname." umode= ".$umode);  
    $npass=&unescape($npass);  
    my $proname=&propath($udom,$uname);  
    my $passfilename="$proname/passwd";  
    if ($udom ne $currentdomainid) {  
       Failure( $client, "not_right_domain\n", $client);  
    } else {  
       my $result=&make_passwd_file($uname, $umode,$npass,$passfilename);  
       Reply($client, $result, $userinput);  
    }  
    return 1;  
 }  
 RegisterHandler("changeuserauth", \&ChangeAuthenticationHandler, 1,1, 0);  
   
 #  
 #   Determines if this is the home server for a user.  The home server  
 #   for a user will have his/her lon-capa passwd file.  Therefore all we need  
 #   to do is determine if this file exists.  
 #  
 # Parameters:  
 #    $cmd      - The command that got us here.  
 #    $tail     - Tail of the command (remaining parameters).  
 #    $client   - File descriptor connected to client.  
 # Returns  
 #     0        - Requested to exit, caller should shut down.  
 #     1        - Continue processing.  
 # Implicit inputs:  
 #    The authentication systems describe above have their own forms of implicit  
 #    input into the authentication process that are described above.  
 #  
 sub IsHomeHandler {  
    my $cmd     = shift;  
    my $tail    = shift;  
    my $client  = shift;  
      
    my $userinput  = "$cmd:$tail";  
      
    my ($udom,$uname)=split(/:/,$tail);  
    chomp($uname);  
    my $proname=propath($udom,$uname);  
    if (-e $proname) {  
       Reply( $client, "found\n", $userinput);  
    } else {  
       Failure($client, "not_found\n", $userinput);  
    }  
    return 1;  
 }  
 RegisterHandler("home", \&IsHomeHandler, 0,1,0);  
 #  
 #   Process an update request for a resource?? I think what's going on here is  
 #   that a resource has been modified that we hold a subscription to.  
 #   If the resource is not local, then we must update, or at least invalidate our  
 #   cached copy of the resource.   
 #   FUTURE WORK:  
 #      I need to look at this logic carefully.  My druthers would be to follow  
 #      typical caching logic, and simple invalidate the cache, drop any subscription  
 #      an let the next fetch start the ball rolling again... however that may  
 #      actually be more difficult than it looks given the complex web of  
 #      proxy servers.  
 # Parameters:  
 #    $cmd      - The command that got us here.  
 #    $tail     - Tail of the command (remaining parameters).  
 #    $client   - File descriptor connected to client.  
 # Returns  
 #     0        - Requested to exit, caller should shut down.  
 #     1        - Continue processing.  
 # Implicit inputs:  
 #    The authentication systems describe above have their own forms of implicit  
 #    input into the authentication process that are described above.  
 #  
 sub UpdateResourceHandler {  
    my $cmd    = shift;  
    my $tail   = shift;  
    my $client = shift;  
      
    my $userinput = "$cmd:$tail";  
      
    my $fname=$tail;  
    my $ownership=ishome($fname);  
    if ($ownership eq 'not_owner') {  
       if (-e $fname) {  
          my ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,  
              $atime,$mtime,$ctime,$blksize,$blocks)=stat($fname);  
          my $now=time;  
          my $since=$now-$atime;  
          if ($since>$perlvar{'lonExpire'}) {  
             my $reply=&reply("unsub:$fname","$clientname");  
             unlink("$fname");  
          } else {  
             my $transname="$fname.in.transfer";  
             my $remoteurl=&reply("sub:$fname","$clientname");  
             my $response;  
             alarm(120);  
             {  
                my $ua=new LWP::UserAgent;  
                my $request=new HTTP::Request('GET',"$remoteurl");  
                $response=$ua->request($request,$transname);  
             }  
             alarm(0);  
             if ($response->is_error()) {  
                unlink($transname);  
                my $message=$response->status_line;  
                &logthis("LWP GET: $message for $fname ($remoteurl)");  
             } else {  
                if ($remoteurl!~/\.meta$/) {  
                   alarm(120);  
                   {  
                      my $ua=new LWP::UserAgent;  
                      my $mrequest=new HTTP::Request('GET',$remoteurl.'.meta');  
                      my $mresponse=$ua->request($mrequest,$fname.'.meta');  
                      if ($mresponse->is_error()) {  
                         unlink($fname.'.meta');  
                      }  
                   }  
                   alarm(0);  
                }  
                rename($transname,$fname);  
             }  
          }  
                Reply( $client, "ok\n", $userinput);  
       } else {  
          Failure($client, "not_found\n", $userinput);  
       }  
    } else {  
       Failure($client, "rejected\n", $userinput);  
    }  
    return 1;  
 }  
 RegisterHandler("update", \&UpdateResourceHandler, 0 ,1, 0);  
   
 #  
 #   Fetch a user file from a remote server:  
 # Parameters:  
 #    $cmd      - The command that got us here.  
 #    $tail     - Tail of the command (remaining parameters).  
 #    $client   - File descriptor connected to client.  
 # Returns  
 #     0        - Requested to exit, caller should shut down.  
 #     1        - Continue processing.  
 #  
 sub FetchUserFileHandler {  
    my $cmd     = shift;  
    my $tail    = shift;  
    my $client  = shift;  
      
    my $userinput = "$cmd:$tail";  
    my $fname           = $tail;  
    my ($udom,$uname,$ufile)=split(/\//,$fname);  
    my $udir=propath($udom,$uname).'/userfiles';  
    unless (-e $udir) {  
       mkdir($udir,0770);   
    }  
    if (-e $udir) {  
       $ufile=~s/^[\.\~]+//;  
       $ufile=~s/\///g;  
       my $destname=$udir.'/'.$ufile;  
       my $transname=$udir.'/'.$ufile.'.in.transit';  
       my $remoteurl='http://'.$clientip.'/userfiles/'.$fname;  
       my $response;  
       alarm(120);  
       {  
          my $ua=new LWP::UserAgent;  
          my $request=new HTTP::Request('GET',"$remoteurl");  
          $response=$ua->request($request,$transname);  
       }  
       alarm(0);  
       if ($response->is_error()) {  
          unlink($transname);  
          my $message=$response->status_line;  
          &logthis("LWP GET: $message for $fname ($remoteurl)");  
          Failure($client, "failed\n", $userinput);  
       } else {  
          if (!rename($transname,$destname)) {  
             &logthis("Unable to move $transname to $destname");  
             unlink($transname);  
             Failure($client, "failed\n", $userinput);  
          } else {  
             Reply($client, "ok\n", $userinput);  
          }  
       }     
    } else {  
       Failure($client, "not_home\n", $userinput);  
    }  
    return 1;  
 }  
 RegisterHandler("fetchuserfile", \&FetchUserFileHandler, 0, 1, 0);  
 #  
 #   Authenticate access to a user file.  Question?   The token for athentication  
 #   is allowed to be sent as cleartext is this really what we want?  This token  
 #   represents the user's session id.  Once it is forged does this allow too much access??  
 #  
 # Parameters:  
 #    $cmd      - The command that got us here.  
 #    $tail     - Tail of the command (remaining parameters).  
 #    $client   - File descriptor connected to client.  
 # Returns  
 #     0        - Requested to exit, caller should shut down.  
 #     1        - Continue processing.  
 sub AuthenticateUserFileAccess {  
    my $cmd   = shift;  
    my $tail    = shift;  
    my $client = shift;  
    my $userinput = "$cmd:$tail";  
   
    my ($fname,$session)=split(/:/,$tail);  
    chomp($session);  
    my $reply='non_auth';  
    if (open(ENVIN,$perlvar{'lonIDsDir'}.'/'.$session.'.id')) {  
       while (my $line=<ENVIN>) {  
          if ($line=~/userfile\.$fname\=/) {   
             $reply='ok';   
          }  
       }  
       close(ENVIN);  
       Reply($client, $reply."\n", $userinput);  
    } else {  
       Failure($client, "invalid_token\n", $userinput);  
    }  
    return 1;  
      
 }  
 RegisterHandler("tokenauthuserfile", \&AuthenticateUserFileAccess, 0, 1, 0);  
 #  
 #   Unsubscribe from a resource.  
 #  #
 # Parameters:  
 #    $cmd      - The command that got us here.  
 #    $tail     - Tail of the command (remaining parameters).  
 #    $client   - File descriptor connected to client.  
 # Returns  
 #     0        - Requested to exit, caller should shut down.  
 #     1        - Continue processing.  
 #  
 sub UnsubscribeHandler {  
    my $cmd      = shift;  
    my $tail     = shift;  
    my $client   = shift;  
    my $userinput= "$cmd:$tail";  
   
    my $fname = $tail;  
    if (-e $fname) {  
       Reply($client, &unsub($client,$fname,$clientip), $userinput);  
    } else {  
       Failure($client, "not_found\n", $userinput);  
    }  
    return 1;  
 }  
 RegisterHandler("unusb", \&UnsubscribeHandler, 0, 1, 0);  
   
 #   Subscribe to a resource.  
 #  
 # Parameters:  
 #    $cmd      - The command that got us here.  
 #    $tail     - Tail of the command (remaining parameters).  
 #    $client   - File descriptor connected to client.  
 # Returns  
 #     0        - Requested to exit, caller should shut down.  
 #     1        - Continue processing.  
 #  
 sub SubscribeHandler {  
    my $cmd        = shift;  
    my $tail       = shift;  
    my $client     = shift;  
    my $userinput  = "$cmd:$tail";  
   
    Reply( $client, &subscribe($userinput,$clientip), $userinput);  
    
    return 1;  
 }  
 RegisterHandler("sub", \&SubscribeHandler, 0, 1, 0);  
   
 #  
 #   Determine the version of a resource (?) Or is it return  
 #   the top version of the resource?  Not yet clear from the  
 #   code in currentversion.  
 #  
 # Parameters:  
 #    $cmd      - The command that got us here.  
 #    $tail     - Tail of the command (remaining parameters).  
 #    $client   - File descriptor connected to client.  
 # Returns  
 #     0        - Requested to exit, caller should shut down.  
 #     1        - Continue processing.  
 #  
 sub CurrentVersionHandler {  
    my $cmd      = shift;  
    my $tail     = shift;  
    my $client   = shift;  
    my $userinput= "$cmd:$tail";  
      
    my $fname   = $tail;  
    Reply( $client, &currentversion($fname)."\n", $userinput);  
    return 1;  
   
 }  
 RegisterHandler("currentversion", \&CurrentVersionHandler, 0, 1, 0);  
   
   
 #  Make an entry in a user's activity log.  
 #  
 # Parameters:  
 #    $cmd      - The command that got us here.  
 #    $tail     - Tail of the command (remaining parameters).  
 #    $client   - File descriptor connected to client.  
 # Returns  
 #     0        - Requested to exit, caller should shut down.  
 #     1        - Continue processing.  
 #  
 sub ActivityLogEntryHandler {  
    my $cmd      = shift;  
    my $tail     = shift;  
    my $client   = shift;  
    my $userinput= "$cmd:$tail";  
   
    my ($udom,$uname,$what)=split(/:/,$tail);  
    chomp($what);  
    my $proname=propath($udom,$uname);  
    my $now=time;  
    my $hfh;  
    if ($hfh=IO::File->new(">>$proname/activity.log")) {   
       print $hfh "$now:$clientname:$what\n";  
       Reply( $client, "ok\n", $userinput);   
    } else {  
       Reply($client, "error: ".($!+0)." IO::File->new Failed "  
             ."while attempting log\n",   
             $userinput);  
    }  
   
    return 1;  
 }  
 RegisterHandler("log", \&ActivityLogEntryHandler, 0, 1, 0);  
 #  
 #   Put a namespace entry in a user profile hash.  
 #   My druthers would be for this to be an encrypted interaction too.  
 #   anything that might be an inadvertent covert channel about either  
 #   user authentication or user personal information....  
 #  
 # Parameters:  
 #    $cmd      - The command that got us here.  
 #    $tail     - Tail of the command (remaining parameters).  
 #    $client   - File descriptor connected to client.  
 # Returns  
 #     0        - Requested to exit, caller should shut down.  
 #     1        - Continue processing.  
 #  
 sub PutUserProfileEntry {  
    my $cmd       = shift;  
    my $tail      = shift;  
    my $client    = shift;  
    my $userinput = "$cmd:$tail";  
   
    my ($udom,$uname,$namespace,$what) =split(/:/,$tail);  
    $namespace=~s/\//\_/g;  
    $namespace=~s/\W//g;  
    if ($namespace ne 'roles') {  
       chomp($what);  
       my $proname=propath($udom,$uname);  
       my $now=time;  
       unless ($namespace=~/^nohist\_/) {  
          my $hfh;  
          if ($hfh=IO::File->new(">>$proname/$namespace.hist")) {   
             print $hfh "P:$now:$what\n";   
          }  
       }  
       my @pairs=split(/\&/,$what);  
       my %hash;  
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",  
                   &GDBM_WRCREAT(),0640)) {  
          foreach my $pair (@pairs) {  
             my ($key,$value)=split(/=/,$pair);  
             $hash{$key}=$value;  
          }  
          if (untie(%hash)) {  
             Reply( $client, "ok\n", $userinput);  
          } else {  
             Failure($client, "error: ".($!+0)." untie(GDBM) failed ".  
                   "while attempting put\n",   
                   $userinput);  
          }  
       } else {  
          Failure( $client, "error: ".($!)." tie(GDBM) Failed ".  
          "while attempting put\n", $userinput);  
       }  
    } else {  
       Failure( $client, "refused\n", $userinput);  
    }  
      
    return 1;  
 }  
 RegisterHandler("put", \&PutUserProfileEntry, 0, 1, 0);  
   
 #   
 #   Increment a profile entry in the user history file.  
 #   The history contains keyword value pairs.  In this case,  
 #   The value itself is a pair of numbers.  The first, the current value  
 #   the second an increment that this function applies to the current  
 #   value.  
 #  
 # Parameters:  
 #    $cmd      - The command that got us here.  
 #    $tail     - Tail of the command (remaining parameters).  
 #    $client   - File descriptor connected to client.  
 # Returns  
 #     0        - Requested to exit, caller should shut down.  
 #     1        - Continue processing.  
 #  
 sub IncrementUserValueHandler {  
    my $cmd         = shift;  
    my $tail        = shift;  
    my $client      = shift;  
    my $userinput   = shift;  
   
    my ($udom,$uname,$namespace,$what) =split(/:/,$tail);  
    $namespace=~s/\//\_/g;  
    $namespace=~s/\W//g;  
    if ($namespace ne 'roles') {  
       chomp($what);  
       my $proname=propath($udom,$uname);  
       my $now=time;  
       unless ($namespace=~/^nohist\_/) {  
          my $hfh;  
          if ($hfh=IO::File->new(">>$proname/$namespace.hist")) {   
             print $hfh "P:$now:$what\n";  
          }  
       }  
       my @pairs=split(/\&/,$what);  
       my %hash;  
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT(),  
                0640)) {  
          foreach my $pair (@pairs) {  
             my ($key,$value)=split(/=/,$pair);  
             # We could check that we have a number...  
             if (! defined($value) || $value eq '') {  
                $value = 1;  
             }  
             $hash{$key}+=$value;  
          }  
          if (untie(%hash)) {  
             Reply( $client, "ok\n", $userinput);  
          } else {  
             Failure($client, "error: ".($!+0)." untie(GDBM) failed ".  
                      "while attempting put\n", $userinput);  
          }  
       } else {  
          Failure($client, "error: ".($!+0)." tie(GDBM) Failed ".  
                   "while attempting put\n", $userinput);  
       }  
    } else {  
       Failure($client, "refused\n", $userinput);  
    }  
   
    return 1;  
 }  
 RegisterHandler("inc", \&IncrementUserValueHandler, 0, 1, 0);  
 #  
 #   Put a new role for a user.  Roles are LonCAPA's packaging of permissions.  
 #   Each 'role' a user has implies a set of permissions.  Adding a new role  
 #   for a person grants the permissions packaged with that role  
 #   to that user when the role is selected.  
 #  
 # Parameters:  
 #    $cmd       - The command string (rolesput).  
 #    $tail      - The remainder of the request line.  For rolesput this  
 #                 consists of a colon separated list that contains:  
 #                 The domain and user that is granting the role (logged).  
 #                 The domain and user that is getting the role.  
 #                 The roles being granted as a set of & separated pairs.  
 #                 each pair a key value pair.  
 #    $client    - File descriptor connected to the client.  
 # Returns:  # Returns:
 #     0         - If the daemon should exit  #     IDEA session key on success.
 #     1         - To continue processing.  #     undef on failure.
 #  
 #  
 sub RolesPutHandler {  
    my $cmd        = shift;  
    my $tail       = shift;  
    my $client     = shift;  
    my $userinput  = "$cmd:$tail";  
      
    my ($exedom,$exeuser,$udom,$uname,$what)   =split(/:/,$tail);  
    &Debug("cmd = ".$cmd." exedom= ".$exedom."user = ".$exeuser." udom=".$udom.  
           "what = ".$what);  
    my $namespace='roles';  
    chomp($what);  
    my $proname=propath($udom,$uname);  
    my $now=time;  
    #  
    #  Log the attempt to set a role.  The {}'s here ensure that the file   
    #  handle is open for the minimal amount of time.  Since the flush  
    #  is done on close this improves the chances the log will be an un-  
    #  corrupted ordered thing.  
    {  
       my $hfh;  
       if ($hfh=IO::File->new(">>$proname/$namespace.hist")) {   
          print $hfh "P:$now:$exedom:$exeuser:$what\n";  
       }  
    }  
    my @pairs=split(/\&/,$what);  
    my %hash;  
    if (tie(%hash,'GDBM_File',"$proname/$namespace.db", &GDBM_WRCREAT(),0640)) {  
       foreach my $pair (@pairs) {  
          my ($key,$value)=split(/=/,$pair);  
             &ManagePermissions($key, $udom, $uname,  
                                &GetAuthType( $udom, $uname));  
             $hash{$key}=$value;  
       }  
       if (untie(%hash)) {  
          Reply($client, "ok\n", $userinput);  
       } else {  
          Failure( $client, "error: ".($!+0)." untie(GDBM) Failed ".  
                          "while attempting rolesput\n", $userinput);  
       }  
    } else {  
       Failure( $client, "error: ".($!+0)." tie(GDBM) Failed ".  
                         "while attempting rolesput\n", $userinput);  
    }  
    return 1;  
 }  
 RegisterHandler("rolesput", \&RolesPutHandler, 1,1,0);  # Encoded client only.  
 #  
 #   Deletes (removes) a role for a user.   This is equivalent to removing  
 #  a permissions package associated with the role from the user's profile.  
 #  #
 # Parameters:  sub LocalConnection {
 #     $cmd                 - The command (rolesdel)      my ($Socket, $initcmd) = @_;
 #     $tail                - The remainder of the request line. This consists      Debug("Attempting local connection: $initcmd client: $clientdns me: $thisserver");
 #                             of:      if($clientdns ne $thisserver) {
 #                             The domain and user requesting the change (logged)   &logthis('<font color="red"> LocalConnection rejecting non local: '
 #                             The domain and user being changed.   ."$clientdns ne $thisserver </font>");
 #                             The roles being revoked.  These are shipped to us   close $Socket;
 #                             as a bunch of & separated role name keywords.   return undef;
 #     $client              - The file handle open on the client.      }  else {
 # Returns:   chomp($initcmd); # Get rid of \n in filename.
 #     1                    - Continue processing   my ($init, $type, $name) = split(/:/, $initcmd);
 #     0                    - Exit.   Debug(" Init command: $init $type $name ");
 #  
 sub RolesDeleteHandler {   # Require that $init = init, and $type = local:  Otherwise
    my $cmd          = shift;   # the caller is insane:
    my $tail         = shift;  
    my $client       = shift;   if(($init ne "init") && ($type ne "local")) {
    my $userinput    = "$cmd:$tail";      &logthis('<font color = "red"> LocalConnection: caller is insane! '
           ."init = $init, and type = $type </font>");
    my ($exedom,$exeuser,$udom,$uname,$what)=split(/:/,$tail);      close($Socket);;
    &Debug("cmd = ".$cmd." exedom= ".$exedom."user = ".$exeuser." udom=".$udom.      return undef;
           "what = ".$what);  
    my $namespace='roles';  
    chomp($what);  
    my $proname=propath($udom,$uname);  
    my $now=time;  
    #  
    #   Log the attempt. This {}'ing is done to ensure that the  
    #   logfile is flushed and closed as quickly as possible.  Hopefully  
    #   this preserves both time ordering and reduces the probability that  
    #   messages will be interleaved.  
    #  
    {  
       my $hfh;  
       if ($hfh=IO::File->new(">>$proname/$namespace.hist")) {   
          print $hfh "D:$now:$exedom:$exeuser:$what\n";  
       }  
    }  
    my @rolekeys=split(/\&/,$what);  
    my %hash;  
    if (tie(%hash,'GDBM_File',"$proname/$namespace.db", &GDBM_WRCREAT(),0640)) {  
       foreach my $key (@rolekeys) {  
          delete $hash{$key};  
       }  
       if (untie(%hash)) {  
          Reply($client, "ok\n", $userinput);  
       } else {  
          Failure( $client, "error: ".($!+0)." untie(GDBM) Failed ".  
                            "while attempting rolesdel\n", $userinput);  
       }  
    } else {  
       Failure( $client, "error: ".($!+0)." tie(GDBM) Failed ".  
                         "while attempting rolesdel\n", $userinput);  
    }  
   
    return 1;  
 }  
 RegisterHandler("rolesdel", \&RolesDeleteHandler, 1,1, 0); # Encoded client only  
   
 # Unencrypted get from a user's profile database.  See   
 # GetProfileEntryEncrypted for a version that does end-to-end encryption.  
 # This function retrieves a keyed item from a specific named database in the  
 # user's directory.  
 #  
 # Parameters:  
 #   $cmd             - Command request keyword (get).  
 #   $tail            - Tail of the command.  This is a colon separated list  
 #                      consisting of the domain and username that uniquely  
 #                      identifies the profile,  
 #                      The 'namespace' which selects the gdbm file to   
 #                      do the lookup in,   
 #                      & separated list of keys to lookup.  Note that  
 #                      the values are returned as an & separated list too.  
 #   $client          - File descriptor open on the client.  
 # Returns:  
 #   1       - Continue processing.  
 #   0       - Exit.  
 #  
 sub GetProfileEntry {  
    my $cmd      = shift;  
    my $tail     = shift;  
    my $client   = shift;  
    my $userinput= "$cmd:$tail";  
      
    my ($udom,$uname,$namespace,$what) = split(/:/,$tail);  
    $namespace=~s/\//\_/g;  
    $namespace=~s/\W//g;  
    chomp($what);  
    my @queries=split(/\&/,$what);  
    my $proname=propath($udom,$uname);  
    my $qresult='';  
    my %hash;  
    if (tie(%hash,'GDBM_File',"$proname/$namespace.db", &GDBM_READER(),0640)) {  
       for (my $i=0;$i<=$#queries;$i++) {  
          $qresult.="$hash{$queries[$i]}&";    # Presumably failure gives empty string.  
       }  
       if (untie(%hash)) {  
          $qresult=~s/\&$//;              # Remove trailing & from last lookup.  
          Reply($client, "$qresult\n", $userinput);  
       } else {  
          Failure($client, "error: ".($!+0)." untie(GDBM) Failed ".  
                           "while attempting get\n", $userinput);  
       }  
    } else {  
       if ($!+0 == 2) {                # +0 coerces errno -> number 2 is ENOENT  
          Failure($client, "error:No such file or ".  
                           "GDBM reported bad block error\n", $userinput);  
       } else {                        # Some other undifferentiated err.  
          Failure($client, "error: ".($!+0)." tie(GDBM) Failed ".  
                            "while attempting get\n", $userinput);  
       }  
    }  
    return 1;  
 }  
 RegisterHandler("get", \&GetProfileEntry, 0,1,0);  
 #  
 #  Process the encrypted get request.  Note that the request is sent  
 #  in clear, but the reply is encrypted.  This is a small covert channel:  
 #  information about the sensitive keys is given to the snooper.  Just not  
 #  information about the values of the sensitive key.  Hmm if I wanted to  
 #  know these I'd snoop for the egets. Get the profile item names from them  
 #  and then issue a get for them since there's no enforcement of the  
 #  requirement of an encrypted get for particular profile items.  If I  
 #  were re-doing this, I'd force the request to be encrypted as well as the  
 #  reply.  I'd also just enforce encrypted transactions for all gets since  
 #  that would prevent any covert channel snooping.  
 #  
 #  Parameters:  
 #     $cmd               - Command keyword of request (eget).  
 #     $tail              - Tail of the command.  See GetProfileEntry #                          for more information about this.  
 #     $client            - File open on the client.  
 #  Returns:  
 #     1      - Continue processing  
 #     0      - server should exit.  
 sub GetProfileEntryEncrypted {  
    my $cmd       = shift;  
    my $tail      = shift;  
    my $client    = shift;  
    my $userinput = "$cmd:$tail";  
      
    my ($cmd,$udom,$uname,$namespace,$what) = split(/:/,$userinput);  
    $namespace=~s/\//\_/g;  
    $namespace=~s/\W//g;  
    chomp($what);  
    my @queries=split(/\&/,$what);  
    my $proname=propath($udom,$uname);  
    my $qresult='';  
    my %hash;  
    if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) {  
       for (my $i=0;$i<=$#queries;$i++) {  
          $qresult.="$hash{$queries[$i]}&";  
       }  
       if (untie(%hash)) {  
          $qresult=~s/\&$//;  
          if ($cipher) {  
             my $cmdlength=length($qresult);  
             $qresult.="         ";  
             my $encqresult='';  
             for(my $encidx=0;$encidx<=$cmdlength;$encidx+=8) {  
                $encqresult.= unpack("H16", $cipher->encrypt(substr($qresult,  
                                                                    $encidx,  
                                                                    8)));  
             }  
             Reply( $client, "enc:$cmdlength:$encqresult\n", $userinput);  
          } else {  
             Failure( $client, "error:no_key\n", $userinput);  
          }  
       } else {  
          Failure($client, "error: ".($!+0)." untie(GDBM) Failed ".  
                               "while attempting eget\n", $userinput);  
       }  
    } else {  
       Failure($client, "error: ".($!+0)." tie(GDBM) Failed ".  
                        "while attempting eget\n", $userinput);  
    }  
            
    return 1;  
 }  
 RegisterHandler("eget", \&GetProfileEncrypted, 0, 1, 0);  
   
 #  
 #   Deletes a key in a user profile database.  
 #     
 #   Parameters:  
 #       $cmd                  - Command keyword (del).  
 #       $tail                 - Command tail.  IN this case a colon  
 #                               separated list containing:  
 #                               The domain and user that identifies uniquely  
 #                               the identity of the user.  
 #                               The profile namespace (name of the profile  
 #                               database file).  
 #                               & separated list of keywords to delete.  
 #       $client              - File open on client socket.  
 # Returns:  
 #     1   - Continue processing  
 #     0   - Exit server.  
 #  
 #  
 sub DeletProfileEntry {  
    my $cmd      = shift;  
    my $tail     = shift;  
    my $client   = shift;  
    my $userinput = "cmd:$tail";  
   
    my ($udom,$uname,$namespace,$what) = split(/:/,$tail);  
    $namespace=~s/\//\_/g;  
    $namespace=~s/\W//g;  
    chomp($what);  
    my $proname=propath($udom,$uname);  
    my $now=time;  
    unless ($namespace=~/^nohist\_/) {  
       my $hfh;  
       if ($hfh=IO::File->new(">>$proname/$namespace.hist")) {   
          print $hfh "D:$now:$what\n";   
       }  
    }  
    my @keys=split(/\&/,$what);  
    my %hash;  
    if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT(),0640)) {  
       foreach my $key (@keys) {  
          delete($hash{$key});  
       }  
       if (untie(%hash)) {  
          Reply($client, "ok\n", $userinput);  
       } else {  
          Failure($client, "error: ".($!+0)." untie(GDBM) Failed ".  
                            "while attempting del\n", $userinput);  
       }  
    } else {  
       Failure( $client, "error: ".($!+0)." tie(GDBM) Failed ".  
                         "while attempting del\n", $userinput);  
    }  
    return 1;  
 }  
 RegisterHandler("del", \&DeleteProfileEntry, 0, 1, 0);  
 #  
 #  List the set of keys that are defined in a profile database file.  
 #  A successful reply from this will contain an & separated list of  
 #  the keys.   
 # Parameters:  
 #     $cmd              - Command request (keys).  
 #     $tail             - Remainder of the request, a colon separated  
 #                         list containing domain/user that identifies the  
 #                         user being queried, and the database namespace  
 #                         (database filename essentially).  
 #     $client           - File open on the client.  
 #  Returns:  
 #    1    - Continue processing.  
 #    0    - Exit the server.  
 #  
 sub GetProfileKeys {  
    my $cmd       = shift;  
    my $tail      = shift;  
    my $client    = shift;  
    my $userinput = "$cmd:$tail";  
   
    my ($udom,$uname,$namespace)=split(/:/,$tail);  
    $namespace=~s/\//\_/g;  
    $namespace=~s/\W//g;  
    my $proname=propath($udom,$uname);  
    my $qresult='';  
    my %hash;  
    if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) {  
       foreach my $key (keys %hash) {  
           $qresult.="$key&";  
       }  
       if (untie(%hash)) {  
          $qresult=~s/\&$//;  
          Reply($client, "$qresult\n", $userinput);  
       } else {  
          Failure($client, "error: ".($!+0)." untie(GDBM) Failed ".  
                           "while attempting keys\n", $userinput);  
       }  
    } else {  
       Failure( $client, "error: ".($!+0)." tie(GDBM) Failed ".  
                         "while attempting keys\n", $userinput);  
    }  
      
    return 1;  
 }  
 RegisterHandler("keys", \&GetProfileKeys, 0, 1, 0);  
 #  
 #   Dump the contents of a user profile database.  
 #   Note that this constitutes a very large covert channel too since  
 #   the dump will return sensitive information that is not encrypted.  
 #   The naive security assumption is that the session negotiation ensures  
 #   our client is trusted and I don't believe that's assured at present.  
 #   Sure want badly to go to ssl or tls.  Of course if my peer isn't really  
 #   a LonCAPA node they could have negotiated an encryption key too so >sigh<.  
 #   
 #  Parameters:  
 #     $cmd           - The command request keyword (currentdump).  
 #     $tail          - Remainder of the request, consisting of a colon  
 #                      separated list that has the domain/username and  
 #                      the namespace to dump (database file).  
 #     $client        - file open on the remote client.  
 # Returns:  
 #     1    - Continue processing.  
 #     0    - Exit the server.  
 #  
 sub DumpProfileDatabase {  
    my $cmd       = shift;  
    my $tail      = shift;  
    my $client    = shift;  
    my $userinput = "$cmd:$tail";  
      
    my ($udom,$uname,$namespace) = split(/:/,$tail);  
    $namespace=~s/\//\_/g;  
    $namespace=~s/\W//g;  
    my $qresult='';  
    my $proname=propath($udom,$uname);  
    my %hash;  
    if (tie(%hash,'GDBM_File',"$proname/$namespace.db", &GDBM_READER(),0640)) {  
       # Structure of %data:  
       # $data{$symb}->{$parameter}=$value;  
       # $data{$symb}->{'v.'.$parameter}=$version;  
       # since $parameter will be unescaped, we do not  
       # have to worry about silly parameter names...  
       my %data = ();                     # A hash of anonymous hashes..  
       while (my ($key,$value) = each(%hash)) {  
          my ($v,$symb,$param) = split(/:/,$key);  
          next if ($v eq 'version' || $symb eq 'keys');  
          next if (exists($data{$symb}) &&   
                   exists($data{$symb}->{$param}) &&  
                   $data{$symb}->{'v.'.$param} > $v);  
          $data{$symb}->{$param}=$value;  
          $data{$symb}->{'v.'.$param}=$v;  
       }  
       if (untie(%hash)) {  
          while (my ($symb,$param_hash) = each(%data)) {  
             while(my ($param,$value) = each (%$param_hash)){  
                next if ($param =~ /^v\./);       # Ignore versions...  
                #  
                #   Just dump the symb=value pairs separated by &  
                #  
                $qresult.=$symb.':'.$param.'='.$value.'&';  
             }  
          }  
          chop($qresult);  
          Reply($client , "$qresult\n", $userinput);  
       } else {  
          Failure( $client, "error: ".($!+0)." untie(GDBM) Failed ".  
                            "while attempting currentdump\n", $userinput);  
       }  
    } else {  
       Failure($client, "error: ".($!+0)." tie(GDBM) Failed ".  
                         "while attempting currentdump\n", $userinput);  
    }  
   
    return 1;  
 }  
 RegisterHandler("currentdump", \&DumpProfileDatabase, 0, 1, 0);  
 #  
 #   Dump a profile database with an optional regular expression  
 #   to match against the keys.  In this dump, no effort is made  
 #   to separate symb from version information. Presumably the  
 #   databases that are dumped by this command are of a different  
 #   structure.  Need to look at this and improve the documentation of  
 #   both this and the currentdump handler.  
 # Parameters:  
 #    $cmd                     - The command keyword.  
 #    $tail                    - All of the characters after the $cmd:  
 #                               These are expected to be a colon  
 #                               separated list containing:  
 #                               domain/user - identifying the user.  
 #                               namespace   - identifying the database.  
 #                               regexp      - optional regular expression  
 #                                             that is matched against  
 #                                             database keywords to do  
 #                                             selective dumps.  
 #   $client                   - Channel open on the client.  
 # Returns:  
 #    1    - Continue processing.  
 # Side effects:  
 #    response is written to $client.  
 #  
 sub DumpWithRegexp {  
   my $cmd    = shift;  
   my $tail   = shift;  
   my $client = shift;  
   
   my $userinput = "$cmd:$tail";  
   
   my ($udom,$uname,$namespace,$regexp)=split(/:/,$tail);  
   $namespace=~s/\//\_/g;  
   $namespace=~s/\W//g;  
   if (defined($regexp)) {  
     $regexp=&unescape($regexp);  
   } else {  
     $regexp='.';  
   }  
   my $qresult='';  
   my $proname=propath($udom,$uname);  
   my %hash;  
   if (tie(%hash,'GDBM_File',"$proname/$namespace.db",  
   &GDBM_READER(),0640)) {  
     study($regexp);  
     while (my ($key,$value) = each(%hash)) {  
       if ($regexp eq '.') {  
  $qresult.=$key.'='.$value.'&';  
       } else {  
  my $unescapeKey = &unescape($key);  
  if (eval('$unescapeKey=~/$regexp/')) {  
   $qresult.="$key=$value&";  
  }   }
       }   #  Now get the key filename:
     }  
     if (untie(%hash)) {  
       chop($qresult);  
       Reply($client, "$qresult\n", $userinput);  
     } else {  
       Failure( $client, "error: ".($!+0)." untie(GDBM) Failed ".  
        "while attempting dump\n", $userinput);  
     }  
   } else {  
     Failure($client, "error: ".($!+0)." tie(GDBM) Failed ".  
     "while attempting dump\n", $userinput);  
   }  
   
     return 1;  
 }  
 RegisterHandler("dump", \&DumpWithRegexp, 0, 1, 0);  
   
 #  Store an aitem in any database but the roles database.  
 #  
 #  Parameters:  
 #    $cmd                - Request command keyword.  
 #    $tail               - Tail of the request.  This is a colon  
 #                          separated list containing:  
 #                          domain/user - User and authentication domain.  
 #                          namespace   - Name of the database being modified  
 #                          rid         - Resource keyword to modify.  
 #                          what        - new value associated with rid.  
 #  
 #    $client             - Socket open on the client.  
 #  
 #  
 #  Returns:  
 #      1 (keep on processing).  
 #  Side-Effects:  
 #    Writes to the client  
 sub StoreHandler {  
   my $cmd    = shift;  
   my $tail   = shift;  
   my $client = shift;  
    
   my $userinput = "$cmd:$tail";  
   
   my ($udom,$uname,$namespace,$rid,$what) =split(/:/,$tail);   my $IDEAKey = lonlocal::ReadKeyFile($name);
   $namespace=~s/\//\_/g;   return $IDEAKey;
   $namespace=~s/\W//g;  
   if ($namespace ne 'roles') {  
     chomp($what);  
     my $proname=propath($udom,$uname);  
     my $now=time;  
     unless ($namespace=~/^nohist\_/) {  
       my $hfh;  
       if ($hfh=IO::File->new(">>$proname/$namespace.hist")) {  
  print $hfh "P:$now:$rid:$what\n";   
       }  
     }  
     my @pairs=split(/\&/,$what);  
     my %hash;  
     if (tie(%hash,'GDBM_File',"$proname/$namespace.db",  
     &GDBM_WRCREAT(),0640)) {  
       my @previouskeys=split(/&/,$hash{"keys:$rid"});  
       my $key;  
       $hash{"version:$rid"}++;  
       my $version=$hash{"version:$rid"};  
       my $allkeys='';   
       foreach my $pair (@pairs) {  
  my ($key,$value)=split(/=/,$pair);  
  $allkeys.=$key.':';  
  $hash{"$version:$rid:$key"}=$value;  
       }  
       $hash{"$version:$rid:timestamp"}=$now;  
       $allkeys.='timestamp';  
       $hash{"$version:keys:$rid"}=$allkeys;  
       if (untie(%hash)) {  
  Reply($client, "ok\n", $userinput);  
       } else {  
  Failure($client, "error: ".($!+0)." untie(GDBM) Failed ".  
  "while attempting store\n", $userinput);  
       }  
     } else {  
       Failure( $client, "error: ".($!+0)." tie(GDBM) Failed ".  
        "while attempting store\n", $userinput);  
     }      }
   } else {  
     Failure($client, "refused\n", $userinput);  
   }  
   
   return 1;  
 }  
 RegisterHandler("store", \&StoreHandler, 0, 1, 0);  
 #  
 #   Restore a prior version of a resource.  
 #  
 #  Parameters:  
 #     $cmd               - Command keyword.  
 #     $tail              - Remainder of the request which consists of:  
 #                          domain/user   - User and auth. domain.  
 #                          namespace     - name of resource database.  
 #                          rid           - Resource id.  
 #    $client             - socket open on the client.  
 #  
 # Returns:  
 #      1  indicating the caller should not yet exit.  
 # Side-effects:  
 #   Writes a reply to the client.  
 #  
 sub RestoreHandler {  
   my $cmd     = shift;  
   my $tail    = shift;  
   my $client  = shift;  
   
   my $userinput = "$cmd:$tail"; # Only used for logging purposes.  
   
   my ($cmd,$udom,$uname,$namespace,$rid) = split(/:/,$userinput);  
   $namespace=~s/\//\_/g;  
   $namespace=~s/\W//g;  
   chomp($rid);  
   my $proname=propath($udom,$uname);  
   my $qresult='';  
   my %hash;  
   if (tie(%hash,'GDBM_File',"$proname/$namespace.db",  
   &GDBM_READER(),0640)) {  
     my $version=$hash{"version:$rid"};  
     $qresult.="version=$version&";  
     my $scope;  
     for ($scope=1;$scope<=$version;$scope++) {  
       my $vkeys=$hash{"$scope:keys:$rid"};  
  my @keys=split(/:/,$vkeys);  
       my $key;  
       $qresult.="$scope:keys=$vkeys&";  
       foreach $key (@keys) {  
  $qresult.="$scope:$key=".$hash{"$scope:$rid:$key"}."&";  
       }                                    
     }  
      if (untie(%hash)) {  
        $qresult=~s/\&$//;  
        Reply( $client, "$qresult\n", $userinput);  
      } else {  
        Failure($client, "error: ".($!+0)." untie(GDBM) Failed ".  
        "while attempting restore\n", $userinput);  
      }  
   } else {  
     Failure($client, "error: ".($!+0)." tie(GDBM) Failed ".  
     "while attempting restore\n", $userinput);  
   }  
     
   return 1;  
   
   
 }  
 RegisterHandler("restor", \&RestoreHandler, 0,1,0);  
   
 #  
 #   Add a chat message to to a discussion board.  
 #  
 # Parameters:  
 #    $cmd                - Request keyword.  
 #    $tail               - Tail of the command. A colon separated list  
 #                          containing:  
 #                          cdom    - Domain on which the chat board lives  
 #                          cnum    - Identifier of the discussion group.  
 #                          post    - Body of the posting.  
 #   $client              - Socket open on the client.  
 # Returns:  
 #   1    - Indicating caller should keep on processing.  
 #  
 # Side-effects:  
 #   writes a reply to the client.  
 #  
 #  
 sub SendChatHandler {  
   my $cmd     = shift;  
   my $tail    = shift;  
   my $client  = shift;  
   
   my $userinput = "$cmd:$tail";  
   
   my ($cdom,$cnum,$newpost)=split(/\:/,$tail);  
   &chatadd($cdom,$cnum,$newpost);  
   Reply($client, "ok\n", $userinput);  
   
   return 1;  
 }  
 RegisterHandler("chatsend", \&SendChatHandler, 0, 1, 0);  
 #  
 #   Retrieve the set of chat messagss from a discussion board.  
 #  
 #  Parameters:  
 #    $cmd             - Command keyword that initiated the request.  
 #    $tail            - Remainder of the request after the command  
 #                       keyword.  In this case a colon separated list of  
 #                       chat domain    - Which discussion board.  
 #                       chat id        - Discussion thread(?)  
 #                       domain/user    - Authentication domain and username  
 #                                        of the requesting person.  
 #   $client           - Socket open on the client program.  
 # Returns:  
 #    1     - continue processing  
 # Side effects:  
 #    Response is written to the client.  
 #  
 sub RetrieveChatHandler {  
   my $cmd      = shift;  
   my $tail     = shift;  
   my $client   = shift;  
   
   my $userinput = "$cmd:$tail";  
   
   my ($cdom,$cnum,$udom,$uname)=split(/\:/,$tail);  
   my $reply='';  
   foreach (&getchat($cdom,$cnum,$udom,$uname)) {  
     $reply.=&escape($_).':';  
   }  
   $reply=~s/\:$//;  
   Reply($client, $reply."\n", $userinput);  
   
   
   return 1;  
 }  }
 RegisterHandler("chatretr", \&RetrieveChatHandler, 0, 1, 0);  #------------------------------------------------------------------------------
 #  #
 #  Initiate a query of an sql database.  SQL query repsonses get put in  #  SSLConnection
 #  a file for later retrieval.  This prevents sql query results from  #   Completes the formation of an ssh authenticated connection. The
 #  bottlenecking the system.  Note that with loncnew, perhaps this is  #   socket is promoted to an ssl socket.  If this promotion and the associated
 #  less of an issue since multiple outstanding requests can be concurrently  #   certificate exchange are successful, the IDEA key is generated and sent
 #  serviced.  #   to the remote peer via the SSL tunnel. The IDEA key is also returned to
   #   the caller after the SSL tunnel is torn down.
 #  #
 #  Parameters:  
 #     $cmd       - COmmand keyword that initiated the request.  
 #     $tail      - Remainder of the command after the keyword.  
 #                  For this function, this consists of a query and  
 #                  3 arguments that are self-documentingly labelled  
 #                  in the original arg1, arg2, arg3.  
 #     $client    - Socket open on the client.  
 # Return:  
 #    1   - Indicating processing should continue.  
 # Side-effects:  
 #    a reply is written to $client.  
 #  
 sub SendQueryHandler {  
   my $cmd     = shift;  
   my $tail    = shift;  
   my $client  = shift;  
   
   my $userinput = "$cmd:$tail";  
   
   my ($query,$arg1,$arg2,$arg3)=split(/\:/,$tail);  
   $query=~s/\n*$//g;  
   Reply($client, "". sqlreply("$clientname\&$query".  
       "\&$arg1"."\&$arg2"."\&$arg3")."\n",  
  $userinput);  
   
   return 1;  
 }  
 RegisterHandler("querysend", \&SendQueryHandler, 0, 1, 0);  
   
 #  
 #   Add a reply to an sql query.  SQL queries are done asyncrhonously.  
 #   The query is submitted via a "querysend" transaction.  
 #   There it is passed on to the lonsql daemon, queued and issued to  
 #   mysql.  
 #     This transaction is invoked when the sql transaction is complete  
 #   it stores the query results in flie and indicates query completion.  
 #   presumably local software then fetches this response... I'm guessing  
 #   the sequence is: lonc does a querysend, we ask lonsql to do it.  
 #   lonsql on completion of the query interacts with the lond of our  
 #   client to do a query reply storing two files:  
 #    - id     - The results of the query.  
 #    - id.end - Indicating the transaction completed.   
 #    NOTE: id is a unique id assigned to the query and querysend time.  
 # Parameters:  # Parameters:
 #    $cmd        - Command keyword that initiated this request.  #   Name              Type             Purpose
 #    $tail       - Remainder of the tail.  In this case that's a colon  #   $Socket          IO::Socket::INET  Plaintext socket.
 #                  separated list containing the query Id and the   
 #                  results of the query.  
 #    $client     - Socket open on the client.  
 # Return:  
 #    1           - Indicating that we should continue processing.  
 # Side effects:  
 #    ok written to the client.  
 #  
 sub ReplyQueryHandler {  
   my $cmd    = shift;  
   my $tail   = shift;  
   my $client = shift;  
   
   my $userinput = "$cmd:$tail";  
   
   my ($cmd,$id,$reply)=split(/:/,$userinput);   
   my $store;  
   my $execdir=$perlvar{'lonDaemons'};  
   if ($store=IO::File->new(">$execdir/tmp/$id")) {  
     $reply=~s/\&/\n/g;  
          print $store $reply;  
     close $store;  
     my $store2=IO::File->new(">$execdir/tmp/$id.end");  
     print $store2 "done\n";  
     close $store2;  
     Reply($client, "ok\n", $userinput);  
   }  
   else {  
     Failure($client, "error: ".($!+0)  
     ." IO::File->new Failed ".  
     "while attempting queryreply\n", $userinput);  
   }  
    
   
   return 1;  
 }  
 RegisterHandler("queryreply", \&ReplyQueryHandler, 0, 1, 0);  
 #  
 #  Process the courseidput query.  Not quite sure what this means  
 #  at the system level sense.  It appears a gdbm file in the   
 #  /home/httpd/lonUsers/$domain/nohist_courseids is tied and  
 #  a set of entries made in that database.  
 #  #
 # Parameters:  
 #   $cmd      - The command keyword that initiated this request.  
 #   $tail     - Tail of the command.  In this case consists of a colon  
 #               separated list contaning the domain to apply this to and  
 #               an ampersand separated list of keyword=value pairs.  
 #   $client   - Socket open on the client.  
 # Returns:  # Returns:
 #   1    - indicating that processing should continue  #    IDEA key on success.
 #  #    undef on failure.
 # Side effects:  
 #   reply is written to the client.  
 #  #
 sub PutCourseIdHandler {  sub SSLConnection {
   my $cmd    = shift;      my $Socket   = shift;
   my $tail   = shift;  
   my $client = shift;  
   
   my $userinput = "$cmd:$tail";  
   
   my ($udom,$what)=split(/:/,$tail);  
   chomp($what);  
   $udom=~s/\W//g;  
   my $proname=  
     "$perlvar{'lonUsersDir'}/$udom/nohist_courseids";  
   my $now=time;  
   my @pairs=split(/\&/,$what);  
   my %hash;  
   if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_WRCREAT(),0640)) {  
     foreach my $pair (@pairs) {  
       my ($key,$value)=split(/=/,$pair);  
       $hash{$key}=$value.':'.$now;  
     }  
     if (untie(%hash)) {  
       Reply($client, "ok\n", $userinput);  
     } else {  
       Failure( $client, "error: ".($!+0)  
        ." untie(GDBM) Failed ".  
        "while attempting courseidput\n", $userinput);  
     }  
   } else {  
     Failure( $client, "error: ".($!+0)  
      ." tie(GDBM) Failed ".  
      "while attempting courseidput\n", $userinput);  
   }  
   
   return 1;  
 }  
 RegisterHandler("courseidput", \&PutCourseIdHandler, 0, 1, 0);  
   
 #  Retrieves the value of a course id resource keyword pattern      Debug("SSLConnection: ");
 #  defined since a starting date.  Both the starting date and the      my $KeyFile         = lonssl::KeyFile();
 #  keyword pattern are optional.  If the starting date is not supplied it      if(!$KeyFile) {
 #  is treated as the beginning of time.  If the pattern is not found,   my $err = lonssl::LastError();
 #  it is treatred as "." matching everything.   &logthis("<font color=\"red\"> CRITICAL"
 #   ."Can't get key file $err </font>");
 #  Parameters:   return undef;
 #     $cmd     - Command keyword that resulted in us being dispatched.  
 #     $tail    - The remainder of the command that, in this case, consists  
 #                of a colon separated list of:  
 #                 domain   - The domain in which the course database is   
 #                            defined.  
 #                 since    - Optional parameter describing the minimum  
 #                            time of definition(?) of the resources that  
 #                            will match the dump.  
 #                 description - regular expression that is used to filter  
 #                            the dump.  Only keywords matching this regexp  
 #                            will be used.  
 #     $client  - The socket open on the client.  
 # Returns:  
 #    1     - Continue processing.  
 # Side Effects:  
 #   a reply is written to $client.  
 sub DumpCourseIdHandler {  
   my $cmd    = shift;  
   my $tail   = shift;  
   my $client = shift;  
   
   my $userinput = "$cmd:$tail";  
   
   my ($udom,$since,$description) =split(/:/,$tail);  
   if (defined($description)) {  
     $description=&unescape($description);  
   } else {  
     $description='.';  
   }  
   unless (defined($since)) { $since=0; }  
   my $qresult='';  
   my $proname = "$perlvar{'lonUsersDir'}/$udom/nohist_courseids";  
   my %hash;  
   if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_READER(),0640)) {  
     while (my ($key,$value) = each(%hash)) {  
       my ($descr,$lasttime)=split(/\:/,$value);  
       if ($lasttime<$since) {   
  next;   
       }  
       if ($description eq '.') {  
  $qresult.=$key.'='.$descr.'&';  
       } else {  
  my $unescapeVal = &unescape($descr);  
  if (eval('$unescapeVal=~/$description/i')) {  
   $qresult.="$key=$descr&";  
  }  
       }  
     }  
     if (untie(%hash)) {  
       chop($qresult);  
       Reply($client, "$qresult\n", $userinput);  
     } else {  
       Failure($client, "error: ".($!+0)." untie(GDBM) Failed ".  
       "while attempting courseiddump\n", $userinput);  
     }      }
   } else {      my ($CACertificate,
     Failure($client, "error: ".($!+0)." tie(GDBM) Failed ".   $Certificate) = lonssl::CertificateFile();
     "while attempting courseiddump\n", $userinput);  
   }  
   
   
   return 1;      # If any of the key, certificate or certificate authority 
 }      # certificate filenames are not defined, this can't work.
 RegisterHandler("courseiddump", \&DumpCourseIdHandler, 0, 1, 0);  
 #  
 #  Puts an id to a domains id database.   
 #  
 #  Parameters:  
 #   $cmd     - The command that triggered us.  
 #   $tail    - Remainder of the request other than the command. This is a   
 #              colon separated list containing:  
 #              $domain  - The domain for which we are writing the id.  
 #              $pairs  - The id info to write... this is and & separated list  
 #                        of keyword=value.  
 #   $client  - Socket open on the client.  
 #  Returns:  
 #    1   - Continue processing.  
 #  Side effects:  
 #     reply is written to $client.  
 #  
 sub PutIdHandler {  
   my $cmd    = shift;  
   my $tail   = shift;  
   my $client = shift;  
   
   my $userinput = "$cmd:$tail";  
   
   my ($udom,$what)=split(/:/,$tail);  
   chomp($what);  
   $udom=~s/\W//g;  
   my $proname="$perlvar{'lonUsersDir'}/$udom/ids";  
   my $now=time;  
   {  
     my $hfh;  
     if ($hfh=IO::File->new(">>$proname.hist")) {   
       print $hfh "P:$now:$what\n";   
     }  
   }  
   my @pairs=split(/\&/,$what);  
   my %hash;  
   if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_WRCREAT(),0640)) {  
     foreach my $pair (@pairs) {  
       my ($key,$value)=split(/=/,$pair);  
       $hash{$key}=$value;  
     }  
     if (untie(%hash)) {  
       Reply($client, "ok\n", $userinput);  
     } else {  
       Failure($client, "error: ".($!+0)." untie(GDBM) Failed ".  
       "while attempting idput\n", $userinput);  
     }  
   } else {  
     Failure( $client, "error: ".($!+0)." tie(GDBM) Failed ".  
      "while attempting idput\n", $userinput);  
   }  
   
   return 1;      if((!$Certificate) || (!$CACertificate)) {
 }   my $err = lonssl::LastError();
    &logthis("<font color=\"red\"> CRITICAL"
    ."Can't get certificates: $err </font>");
   
 RegisterHandler("idput", \&PutIdHandler, 0, 1, 0);   return undef;
 #  
 #  Retrieves a set of id values from the id database.  
 #  Returns an & separated list of results, one for each requested id to the  
 #  client.  
 #  
 # Parameters:  
 #   $cmd       - Command keyword that caused us to be dispatched.  
 #   $tail      - Tail of the command.  Consists of a colon separated:  
 #               domain - the domain whose id table we dump  
 #               ids      Consists of an & separated list of  
 #                        id keywords whose values will be fetched.  
 #                        nonexisting keywords will have an empty value.  
 #   $client    - Socket open on the client.  
 #  
 # Returns:  
 #    1 - indicating processing should continue.  
 # Side effects:  
 #   An & separated list of results is written to $client.  
 #  
 sub GetIdHandler {  
   my $cmd    = shift;  
   my $tail   = shift;  
   my $client = shift;  
   
   my $userinput = "$client:$tail";  
   
   my ($udom,$what)=split(/:/,$tail);  
   chomp($what);  
   $udom=~s/\W//g;  
   my $proname="$perlvar{'lonUsersDir'}/$udom/ids";  
   my @queries=split(/\&/,$what);  
   my $qresult='';  
   my %hash;  
   if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_READER(),0640)) {  
     for (my $i=0;$i<=$#queries;$i++) {  
       $qresult.="$hash{$queries[$i]}&";  
     }  
     if (untie(%hash)) {  
       $qresult=~s/\&$//;  
       Reply($client, "$qresult\n", $userinput);  
     } else {  
       Failure( $client, "error: ".($!+0)." untie(GDBM) Failed ".  
        "while attempting idget\n",$userinput);  
     }      }
   } else {      Debug("Key: $KeyFile CA: $CACertificate Cert: $Certificate");
     Failure($client, "error: ".($!+0)." tie(GDBM) Failed ".  
                         "while attempting idget\n",$userinput);  
   }  
   
   return 1;  
 }  
   
 RegisterHandler("idget", \&GetIdHandler, 0, 1, 0);  
 #  
 #  Process the tmpput command I'm not sure what this does.. Seems to  
 #  create a file in the lonDaemons/tmp directory of the form $id.tmp  
 # where Id is the client's ip concatenated with a sequence number.  
 # The file will contain some value that is passed in.  Is this e.g.  
 # a login token?  
 #  
 # Parameters:  
 #    $cmd     - The command that got us dispatched.  
 #    $tail    - The remainder of the request following $cmd:  
 #               In this case this will be the contents of the file.  
 #    $client  - Socket connected to the client.  
 # Returns:  
 #    1 indicating processing can continue.  
 # Side effects:  
 #   A file is created in the local filesystem.  
 #   A reply is sent to the client.  
 sub TmpPutHandler {  
   my $cmd       = shift;  
   my $what      = shift;  
   my $client    = shift;  
   
   my $userinput = "$cmd:$what"; # Reconstruct for logging.  
   
   
   my $store;  
   $tmpsnum++;  
   my $id=$$.'_'.$clientip.'_'.$tmpsnum;  
   $id=~s/\W/\_/g;  
   $what=~s/\n//g;  
   my $execdir=$perlvar{'lonDaemons'};  
   if ($store=IO::File->new(">$execdir/tmp/$id.tmp")) {  
     print $store $what;  
     close $store;  
     Reply($client, "$id\n", $userinput);  
   }  
   else {  
     Failure( $client, "error: ".($!+0)."IO::File->new Failed ".  
      "while attempting tmpput\n", $userinput);  
   }  
   return 1;  
     
 }  
 RegisterHandler("tmpput", \&TmpPutHandler, 0, 1, 0);  
   
 #   Processes the tmpget command.  This command returns the contents  
 #  of a temporary resource file(?) created via tmpput.  
 #  
 # Paramters:  
 #    $cmd      - Command that got us dispatched.  
 #    $id       - Tail of the command, contain the id of the resource  
 #                we want to fetch.  
 #    $client   - socket open on the client.  
 # Return:  
 #    1         - Inidcating processing can continue.  
 # Side effects:  
 #   A reply is sent to the client.  
   
 #      # Indicate to our peer that we can procede with
 sub TmpGetHandler {      # a transition to ssl authentication:
   my $cmd       = shift;  
   my $id        = shift;  
   my $client    = shift;  
   my $userinput = "$cmd:$id";   
   
   chomp($id);  
   $id=~s/\W/\_/g;  
   my $store;  
   my $execdir=$perlvar{'lonDaemons'};  
   if ($store=IO::File->new("$execdir/tmp/$id.tmp")) {  
     my $reply=<$store>;  
     Reply( $client, "$reply\n", $userinput);  
     close $store;  
   }  
   else {  
     Failure( $client, "error: ".($!+0)."IO::File->new Failed ".  
      "while attempting tmpget\n", $userinput);  
   }  
   
   return 1;  
 }  
 RegisterHandler("tmpget", \&TmpGetHandler, 0, 1, 0);  
 #  
 #  Process the tmpdel command.  This command deletes a temp resource  
 #  created by the tmpput command.  
 #  
 # Parameters:  
 #   $cmd      - Command that got us here.  
 #   $id       - Id of the temporary resource created.  
 #   $client   - socket open on the client process.  
 #  
 # Returns:  
 #   1     - Indicating processing should continue.  
 # Side Effects:  
 #   A file is deleted  
 #   A reply is sent to the client.  
 sub TmpDelHandler {  
   my $cmd      = shift;  
   my $id       = shift;  
   my $client   = shift;  
   
   my $userinput= "$cmd:$id";  
   
   chomp($id);  
   $id=~s/\W/\_/g;  
   my $execdir=$perlvar{'lonDaemons'};  
   if (unlink("$execdir/tmp/$id.tmp")) {  
     Reply($client, "ok\n", $userinput);  
   } else {  
     Failure( $client, "error: ".($!+0)."Unlink tmp Failed ".  
      "while attempting tmpdel\n", $userinput);  
   }  
   
   return 1;      print $Socket "ok:ssl\n";
   
 }      Debug("Approving promotion -> ssl");
 RegisterHandler("tmpdel", \&TmpDelHandler, 0, 1, 0);      #  And do so:
 #  
 #   ls  - list the contents of a directory.  For each file in the      my $SSLSocket = lonssl::PromoteServerSocket($Socket,
 #    selected directory the filename followed by the full output of   $CACertificate,
 #    the stat function is returned.  The returned info for each   $Certificate,
 #    file are separated by ':'.  The stat fields are separated by &'s.   $KeyFile);
 # Parameters:      if(! ($SSLSocket) ) { # SSL socket promotion failed.
 #    $cmd        - The command that dispatched us (ls).   my $err = lonssl::LastError();
 #    $ulsdir     - The directory path to list... I'm not sure what this   &logthis("<font color=\"red\"> CRITICAL "
 #                  is relative as things like ls:. return e.g.   ."SSL Socket promotion failed: $err </font>");
 #                  no_such_dir.   return undef;
 #    $client     - Socket open on the client.  
 # Returns:  
 #     1 - indicating that the daemon should not disconnect.  
 # Side Effects:  
 #   The reply is written to  $client.  
 #  
 sub LsHandler {  
   my $cmd     = shift;  
   my $ulsdir  = shift;  
   my $client  = shift;  
   
   my $userinput = "$cmd:$ulsdir";  
   
   my $ulsout='';  
   my $ulsfn;  
   if (-e $ulsdir) {  
     if(-d $ulsdir) {  
       if (opendir(LSDIR,$ulsdir)) {  
  while ($ulsfn=readdir(LSDIR)) {  
   my @ulsstats=stat($ulsdir.'/'.$ulsfn);  
   $ulsout.=$ulsfn.'&'.  
     join('&',@ulsstats).':';  
  }  
  closedir(LSDIR);  
       }  
     } else {  
       my @ulsstats=stat($ulsdir);  
       $ulsout.=$ulsfn.'&'.join('&',@ulsstats).':';  
     }      }
   } else {      Debug("SSL Promotion successful");
     $ulsout='no_such_dir';  
   }  
   if ($ulsout eq '') { $ulsout='empty'; }  
   Reply($client, "$ulsout\n", $userinput);  
   
   
   return 1;  
 }  
 RegisterHandler("ls", \&LsHandler, 0, 1, 0);  
   
   
 #  
 #   Processes the setannounce command.  This command  
 #   creates a file named announce.txt in the top directory of  
 #   the documentn root and sets its contents.  The announce.txt file is  
 #   printed in its entirety at the LonCAPA login page.  Note:  
 #   once the announcement.txt fileis created it cannot be deleted.  
 #   However, setting the contents of the file to empty removes the  
 #   announcement from the login page of loncapa so who cares.  
 #  
 # Parameters:  
 #    $cmd          - The command that got us dispatched.  
 #    $announcement - The text of the announcement.  
 #    $client       - Socket open on the client process.  
 # Retunrns:  
 #   1             - Indicating request processing should continue  
 # Side Effects:  
 #   The file {DocRoot}/announcement.txt is created.  
 #   A reply is sent to $client.  
 #  
 sub SetAnnounceHandler {  
   my $cmd          = shift;  
   my $announcement = shift;  
   my $client       = shift;  
     
   my $userinput    = "$cmd:$announcement";  
   
   chomp($announcement);      # 
   $announcement=&unescape($announcement);      #  The only thing we'll use the socket for is to send the IDEA key
   if (my $store=IO::File->new('>'.$perlvar{'lonDocRoot'}.      #  to the peer:
       '/announcement.txt')) {  
     print $store $announcement;  
     close $store;  
     Reply($client, "ok\n", $userinput);  
   } else {  
     Failure($client, "error: ".($!+0)."\n", $userinput);  
   }  
   
   return 1;  
 }  
 RegisterHandler("setannounce", \&SetAnnounceHandler, 0, 1, 0);  
   
 #      my $Key = lonlocal::CreateCipherKey();
 #  Return the version of the daemon.  This can be used to determine      print $SSLSocket "$Key\n";
 #  the compatibility of cross version installations or, alternatively to  
 #  simply know who's out of date and who isn't.  Note that the version  
 #  is returned concatenated with the tail.  
 # Parameters:  
 #   $cmd        - the request that dispatched to us.  
 #   $tail       - Tail of the request (client's version?).  
 #   $client     - Socket open on the client.  
 #Returns:  
 #   1 - continue processing requests.  
 # Side Effects:  
 #   Replies with version to $client.  
 sub GetVersionHandler {  
   my $client     = shift;  
   my $tail       = shift;  
   my $client     = shift;  
   my $userinput  = $client;  
   
   Reply($client, &version($userinput)."\n", $userinput);  
   
   
   return 1;  
 }  
 RegisterHandler("version", \&GetVersionHandler, 0, 1, 0);  
   
 #  Set the current host and domain.  This is used to support  
 #  multihomed systems.  Each IP of the system, or even separate daemons  
 #  on the same IP can be treated as handling a separate lonCAPA virtual  
 #  machine.  This command selects the virtual lonCAPA.  The client always  
 #  knows the right one since it is lonc and it is selecting the domain/system  
 #  from the hosts.tab file.  
 # Parameters:  
 #    $cmd      - Command that dispatched us.  
 #    $tail     - Tail of the command (domain/host requested).  
 #    $socket   - Socket open on the client.  
 #  
 # Returns:  
 #     1   - Indicates the program should continue to process requests.  
 # Side-effects:  
 #     The default domain/system context is modified for this daemon.  
 #     a reply is sent to the client.  
 #  
 sub SelectHostHandler {  
   my $cmd        = shift;  
   my $tail       = shift;  
   my $socket     = shift;  
     
   my $userinput  ="$cmd:$tail";  
   
   Reply($client, &sethost($userinput)."\n", $userinput);      lonssl::Close($SSLSocket); 
   
       Debug("Key exchange complete: $Key");
   
   return 1;      return $Key;
 }  }
 RegisterHandler("sethost", \&SelectHostHandler, 0, 1, 0);  
   
 #  Process a request to exit:  
 #   - "bye" is sent to the client.  
 #   - The client socket is shutdown and closed.  
 #   - We indicate to the caller that we should exit.  
 # Formal Parameters:  
 #   $cmd                - The command that got us here.  
 #   $tail               - Tail of the command (empty).  
 #   $client             - Socket open on the tail.  
 # Returns:  
 #   0      - Indicating the program should exit!!  
 #  #
 sub ExitHandler {  #     InsecureConnection: 
   my $cmd     = shift;  #        If insecure connections are allowd,
   my $tail    = shift;  #        exchange a challenge with the client to 'validate' the
   my $client  = shift;  #        client (not really, but that's the protocol):
   #        We produce a challenge string that's sent to the client.
   my $userinput = "$cmd:$tail";  #        The client must then echo the challenge verbatim to us.
   
   &logthis("Client $clientip ($clientname) hanging up: $userinput");  
   Reply($client, "bye\n", $userinput);  
   $client->shutdown(2);        # shutdown the socket forcibly.  
   $client->close();  
   
   return 0;  
 }  
 RegisterHandler("exit", \&ExitHandler, 0, 1,1);  
 RegisterHandler("init", \&ExitHandler, 0, 1,1); # RE-init is like exit.  
 RegisterHandler("quit", \&ExitHandler, 0, 1,1); # I like this too!  
 #------------------------------------------------------------------------------------  
 #  
 #   Process a Request.  Takes a request from the client validates  
 #   it and performs the operation requested by it.  Returns  
 #   a response to the client.  
 #  #
 #  Parameters:  #  Parameter:
 #      request      - A string containing the user's request.  #      Socket      - Socket open on the client.
 #  Returns:  #  Returns:
 #      0            - Requested to exit, caller should shut down.  #      1           - success.
 #      1            - Accept additional requests from the client.  #      0           - failure (e.g.mismatch or insecure not allowed).
 #  #
 sub ProcessRequest {  sub InsecureConnection {
    my $Request      = shift;      my $Socket  =  shift;
    my $KeepGoing    = 1; # Assume we're not asked to stop.  
       
    my $wasenc=0;  
    my $userinput = $Request;   # for compatibility with oldcode <yeach>  
   
   
 # ------------------------------------------------------------ See if encrypted  
      
    if($userinput =~ /^enc/) {  
       $wasenc = 1;  
       $userinput = Decipher($userinput);  
       if(! $userinput) {  
          Failure($client,"error:Encrypted data without negotiating key");  
          return 0;                      # Break off with this imposter.  
       }  
    }  
    # Split off the request keyword from the rest of the stuff.  
      
    my ($command, $tail) = split(/:/, $userinput, 2);  
   
    Debug("Command received: $command, encoded = $wasenc");      #   Don't even start if insecure connections are not allowed.
   
      
 # ------------------------------------------------------------- Normal commands  
   
    #   
    #   If the command is in the hash, then execute it via the hash dispatch:  
    #  
    if(defined $Dispatcher{$command}) {  
   
       my $DispatchInfo = $Dispatcher{$command};  
       my $Handler      = $$DispatchInfo[0];  
       my $NeedEncode   = $$DispatchInfo[1];  
       my $ClientTypes  = $$DispatchInfo[2];  
       Debug("Matched dispatch hash: mustencode: $NeedEncode ClientType $ClientTypes");  
         
       #  Validate the request:  
         
       my $ok = 1;  
       my $requesterprivs = 0;  
       if(isClient()) {  
  $requesterprivs |= $CLIENT_OK;  
       }  
       if(isManager()) {  
  $requesterprivs |= $MANAGER_OK;  
       }  
       if($NeedEncode && (!$wasenc)) {  
  Debug("Must encode but wasn't: $NeedEncode $wasenc");  
          $ok = 0;  
       }  
       if(($ClientTypes & $requesterprivs) == 0) {  
  Debug("Client not privileged to do this operation");  
  $ok = 0;  
       }  
   
       if($ok) {  
  Debug("Dispatching to handler $command $tail");  
          $KeepGoing = &$Handler($command, $tail, $client);  
       } else {  
  Debug("Refusing to dispatch because ok is false");  
  Failure($client, "refused", $userinput);  
       }  
   
       if(! $perlvar{londAllowInsecure}) { # Insecure connections not allowed.
    return 0;
       }
   
 # ------------------------------------------------------------- unknown command      #   Fabricate a challenge string and send it..
   
    } else {      my $challenge = "$$".time; # pid + time.
  # unknown command      print $Socket "$challenge\n";
       Failure($client, "unknown_cmd\n", $userinput);      &status("Waiting for challenge reply");
    }  
       my $answer = <$Socket>;
       $answer    =~s/\W//g;
       if($challenge eq $answer) {
    return 1;
       } else {
    logthis("<font color='blue'>WARNING client did not respond to challenge</font>");
    &status("No challenge reqply");
    return 0;
       }
       
   
     return $KeepGoing;  
 }  }
   
   
 #  #
 #   GetCertificate: Given a transaction that requires a certificate,  #   GetCertificate: Given a transaction that requires a certificate,
 #   this function will extract the certificate from the transaction  #   this function will extract the certificate from the transaction
Line 2825  sub GetCertificate { Line 351  sub GetCertificate {
     return $clientip;      return $clientip;
 }  }
   
   #
   #   Return true if client is a manager.
   #
   sub isManager {
       return (($ConnectionType eq "manager") || ($ConnectionType eq "both"));
   }
   #
   #   Return tru if client can do client functions
   #
   sub isClient {
       return (($ConnectionType eq "client") || ($ConnectionType eq "both"));
   }
   
   
 #  #
Line 2851  sub ReadManagerTable { Line 389  sub ReadManagerTable {
    while(my $host = <MANAGERS>) {     while(my $host = <MANAGERS>) {
       chomp($host);        chomp($host);
       if ($host =~ "^#") {                  # Comment line.        if ($host =~ "^#") {                  # Comment line.
          logthis('<font color="green"> Skipping line: '. "$host</font>\n");  
          next;           next;
       }        }
       if (!defined $hostip{$host}) { # This is a non cluster member        if (!defined $hostip{$host}) { # This is a non cluster member
Line 2901  sub ValidManager { Line 438  sub ValidManager {
 #     1   - Success.  #     1   - Success.
 #  #
 sub CopyFile {  sub CopyFile {
     my $oldfile = shift;  
     my $newfile = shift;      my ($oldfile, $newfile) = @_;
   
     #  The file must exist:      #  The file must exist:
   
Line 3002  sub AdjustHostContents { Line 539  sub AdjustHostContents {
 #      0       - failure and $! has an errno.  #      0       - failure and $! has an errno.
 #  #
 sub InstallFile {  sub InstallFile {
     my $Filename = shift;  
     my $Contents = shift;      my ($Filename, $Contents) = @_;
     my $TempFile = $Filename.".tmp";      my $TempFile = $Filename.".tmp";
   
     #  Open the file for write:      #  Open the file for write:
Line 3026  sub InstallFile { Line 563  sub InstallFile {
   
     return 1;      return 1;
 }  }
   
   
 #  #
 #   ConfigFileFromSelector: converts a configuration file selector  #   ConfigFileFromSelector: converts a configuration file selector
 #                 (one of host or domain at this point) into a   #                 (one of host or domain at this point) into a 
Line 3115  sub PushFile { Line 654  sub PushFile {
  &logthis('<font color="red"> Pushfile: unable to install '   &logthis('<font color="red"> Pushfile: unable to install '
  .$tablefile." $! </font>");   .$tablefile." $! </font>");
  return "error:$!";   return "error:$!";
     }      } else {
     else {  
  &logthis('<font color="green"> Installed new '.$tablefile   &logthis('<font color="green"> Installed new '.$tablefile
  ."</font>");   ."</font>");
   
Line 3240  sub isValidEditCommand { Line 778  sub isValidEditCommand {
 #                  file being edited.  #                  file being edited.
 #  #
 sub ApplyEdit {  sub ApplyEdit {
     my $directive   = shift;  
     my $editor      = shift;      my ($directive, $editor) = @_;
   
     # Break the directive down into its command and its parameters      # Break the directive down into its command and its parameters
     # (at most two at this point.  The meaning of the parameters, if in fact      # (at most two at this point.  The meaning of the parameters, if in fact
Line 3325  sub AdjustOurHost { Line 863  sub AdjustOurHost {
 #        editor     - Editor containing the file.  #        editor     - Editor containing the file.
 #  #
 sub ReplaceConfigFile {  sub ReplaceConfigFile {
     my $filename  = shift;      
     my $editor    = shift;      my ($filename, $editor) = @_;
   
     CopyFile ($filename, $filename.".old");      CopyFile ($filename, $filename.".old");
   
Line 3395  sub EditFile { Line 933  sub EditFile {
   
     return "ok\n";      return "ok\n";
 }  }
   
   #---------------------------------------------------------------
   #
   # Manipulation of hash based databases (factoring out common code
   # for later use as we refactor.
   #
   #  Ties a domain level resource file to a hash.
   #  If requested a history entry is created in the associated hist file.
   #
   #  Parameters:
   #     domain    - Name of the domain in which the resource file lives.
   #     namespace - Name of the hash within that domain.
   #     how       - How to tie the hash (e.g. GDBM_WRCREAT()).
   #     loghead   - Optional parameter, if present a log entry is created
   #                 in the associated history file and this is the first part
   #                  of that entry.
   #     logtail   - Goes along with loghead,  The actual logentry is of the
   #                 form $loghead:<timestamp>:logtail.
   # Returns:
   #    Reference to a hash bound to the db file or alternatively undef
   #    if the tie failed.
   #
   sub tie_domain_hash {
       my ($domain,$namespace,$how,$loghead,$logtail) = @_;
       
       # Filter out any whitespace in the domain name:
       
       $domain =~ s/\W//g;
       
       # We have enough to go on to tie the hash:
       
       my $user_top_dir   = $perlvar{'lonUsersDir'};
       my $domain_dir     = $user_top_dir."/$domain";
       my $resource_file  = $domain_dir."/$namespace.db";
       my %hash;
       if(tie(%hash, 'GDBM_File', $resource_file, $how, 0640)) {
    if (defined($loghead)) { # Need to log the operation.
       my $logFh = IO::File->new(">>$domain_dir/$namespace.hist");
       if($logFh) {
    my $timestamp = time;
    print $logFh "$loghead:$timestamp:$logtail\n";
       }
       $logFh->close;
    }
    return \%hash; # Return the tied hash.
       } else {
    return undef; # Tie failed.
       }
   }
   
   #
   #   Ties a user's resource file to a hash.  
   #   If necessary, an appropriate history
   #   log file entry is made as well.
   #   This sub factors out common code from the subs that manipulate
   #   the various gdbm files that keep keyword value pairs.
   # Parameters:
   #   domain       - Name of the domain the user is in.
   #   user         - Name of the 'current user'.
   #   namespace    - Namespace representing the file to tie.
   #   how          - What the tie is done to (e.g. GDBM_WRCREAT().
   #   loghead      - Optional first part of log entry if there may be a
   #                  history file.
   #   what         - Optional tail of log entry if there may be a history
   #                  file.
   # Returns:
   #   hash to which the database is tied.  It's up to the caller to untie.
   #   undef if the has could not be tied.
   #
   sub tie_user_hash {
       my ($domain,$user,$namespace,$how,$loghead,$what) = @_;
   
       $namespace=~s/\//\_/g; # / -> _
       $namespace=~s/\W//g; # whitespace eliminated.
       my $proname     = propath($domain, $user);
      
       #  Tie the database.
       
       my %hash;
       if(tie(%hash, 'GDBM_File', "$proname/$namespace.db",
      $how, 0640)) {
    # If this is a namespace for which a history is kept,
    # make the history log entry:    
    if (($namespace =~/^nohist\_/) && (defined($loghead))) {
       my $args = scalar @_;
       Debug(" Opening history: $namespace $args");
       my $hfh = IO::File->new(">>$proname/$namespace.hist"); 
       if($hfh) {
    my $now = time;
    print $hfh "$loghead:$now:$what\n";
       }
       $hfh->close;
    }
    return \%hash;
       } else {
    return undef;
       }
       
   }
   
   #--------------------- Request Handlers --------------------------------------------
   #
   #   By convention each request handler registers itself prior to the sub 
   #   declaration:
   #
   
   #++
   #
   #  Handles ping requests.
   #  Parameters:
   #      $cmd    - the actual keyword that invoked us.
   #      $tail   - the tail of the request that invoked us.
   #      $replyfd- File descriptor connected to the client
   #  Implicit Inputs:
   #      $currenthostid - Global variable that carries the name of the host we are
   #                       known as.
   #  Returns:
   #      1       - Ok to continue processing.
   #      0       - Program should exit.
   #  Side effects:
   #      Reply information is sent to the client.
   
   sub ping_handler {
       my ($cmd, $tail, $client) = @_;
       Debug("$cmd $tail $client .. $currenthostid:");
      
       Reply( $client,"$currenthostid\n","$cmd:$tail");
      
       return 1;
   }
   &register_handler("ping", \&ping_handler, 0, 1, 1);       # Ping unencoded, client or manager.
   
   #++
   #
   # Handles pong requests.  Pong replies with our current host id, and
   #                         the results of a ping sent to us via our lonc.
   #
   # Parameters:
   #      $cmd    - the actual keyword that invoked us.
   #      $tail   - the tail of the request that invoked us.
   #      $replyfd- File descriptor connected to the client
   #  Implicit Inputs:
   #      $currenthostid - Global variable that carries the name of the host we are
   #                       connected to.
   #  Returns:
   #      1       - Ok to continue processing.
   #      0       - Program should exit.
   #  Side effects:
   #      Reply information is sent to the client.
   
   sub pong_handler {
       my ($cmd, $tail, $replyfd) = @_;
   
       my $reply=&reply("ping",$clientname);
       &Reply( $replyfd, "$currenthostid:$reply\n", "$cmd:$tail"); 
       return 1;
   }
   &register_handler("pong", \&pong_handler, 0, 1, 1);       # Pong unencoded, client or manager
   
   #++
   #      Called to establish an encrypted session key with the remote client.
   #      Note that with secure lond, in most cases this function is never
   #      invoked.  Instead, the secure session key is established either
   #      via a local file that's locked down tight and only lives for a short
   #      time, or via an ssl tunnel...and is generated from a bunch-o-random
   #      bits from /dev/urandom, rather than the predictable pattern used by
   #      by this sub.  This sub is only used in the old-style insecure
   #      key negotiation.
   # Parameters:
   #      $cmd    - the actual keyword that invoked us.
   #      $tail   - the tail of the request that invoked us.
   #      $replyfd- File descriptor connected to the client
   #  Implicit Inputs:
   #      $currenthostid - Global variable that carries the name of the host
   #                       known as.
   #      $clientname    - Global variable that carries the name of the hsot we're connected to.
   #  Returns:
   #      1       - Ok to continue processing.
   #      0       - Program should exit.
   #  Implicit Outputs:
   #      Reply information is sent to the client.
   #      $cipher is set with a reference to a new IDEA encryption object.
   #
   sub establish_key_handler {
       my ($cmd, $tail, $replyfd) = @_;
   
       my $buildkey=time.$$.int(rand 100000);
       $buildkey=~tr/1-6/A-F/;
       $buildkey=int(rand 100000).$buildkey.int(rand 100000);
       my $key=$currenthostid.$clientname;
       $key=~tr/a-z/A-Z/;
       $key=~tr/G-P/0-9/;
       $key=~tr/Q-Z/0-9/;
       $key=$key.$buildkey.$key.$buildkey.$key.$buildkey;
       $key=substr($key,0,32);
       my $cipherkey=pack("H32",$key);
       $cipher=new IDEA $cipherkey;
       &Reply($replyfd, "$buildkey\n", "$cmd:$tail"); 
      
       return 1;
   
   }
   &register_handler("ekey", \&establish_key_handler, 0, 1,1);
   
   
   #     Handler for the load command.  Returns the current system load average
   #     to the requestor.
   #
   # Parameters:
   #      $cmd    - the actual keyword that invoked us.
   #      $tail   - the tail of the request that invoked us.
   #      $replyfd- File descriptor connected to the client
   #  Implicit Inputs:
   #      $currenthostid - Global variable that carries the name of the host
   #                       known as.
   #      $clientname    - Global variable that carries the name of the hsot we're connected to.
   #  Returns:
   #      1       - Ok to continue processing.
   #      0       - Program should exit.
   #  Side effects:
   #      Reply information is sent to the client.
   sub load_handler {
       my ($cmd, $tail, $replyfd) = @_;
   
      # Get the load average from /proc/loadavg and calculate it as a percentage of
      # the allowed load limit as set by the perl global variable lonLoadLim
   
       my $loadavg;
       my $loadfile=IO::File->new('/proc/loadavg');
      
       $loadavg=<$loadfile>;
       $loadavg =~ s/\s.*//g;                      # Extract the first field only.
      
       my $loadpercent=100*$loadavg/$perlvar{'lonLoadLim'};
   
       &Reply( $replyfd, "$loadpercent\n", "$cmd:$tail");
      
       return 1;
   }
   register_handler("load", \&load_handler, 0, 1, 0);
   
   #
   #   Process the userload request.  This sub returns to the client the current
   #  user load average.  It can be invoked either by clients or managers.
   #
   # Parameters:
   #      $cmd    - the actual keyword that invoked us.
   #      $tail   - the tail of the request that invoked us.
   #      $replyfd- File descriptor connected to the client
   #  Implicit Inputs:
   #      $currenthostid - Global variable that carries the name of the host
   #                       known as.
   #      $clientname    - Global variable that carries the name of the hsot we're connected to.
   #  Returns:
   #      1       - Ok to continue processing.
   #      0       - Program should exit
   # Implicit inputs:
   #     whatever the userload() function requires.
   #  Implicit outputs:
   #     the reply is written to the client.
   #
   sub user_load_handler {
       my ($cmd, $tail, $replyfd) = @_;
   
       my $userloadpercent=&userload();
       &Reply($replyfd, "$userloadpercent\n", "$cmd:$tail");
       
       return 1;
   }
   register_handler("userload", \&user_load_handler, 0, 1, 0);
   
   #   Process a request for the authorization type of a user:
   #   (userauth).
   #
   # Parameters:
   #      $cmd    - the actual keyword that invoked us.
   #      $tail   - the tail of the request that invoked us.
   #      $replyfd- File descriptor connected to the client
   #  Returns:
   #      1       - Ok to continue processing.
   #      0       - Program should exit
   # Implicit outputs:
   #    The user authorization type is written to the client.
   #
   sub user_authorization_type {
       my ($cmd, $tail, $replyfd) = @_;
      
       my $userinput = "$cmd:$tail";
      
       #  Pull the domain and username out of the command tail.
       # and call get_auth_type to determine the authentication type.
      
       my ($udom,$uname)=split(/:/,$tail);
       my $result = &get_auth_type($udom, $uname);
       if($result eq "nouser") {
    &Failure( $replyfd, "unknown_user\n", $userinput);
       } else {
    #
    # We only want to pass the second field from get_auth_type
    # for ^krb.. otherwise we'll be handing out the encrypted
    # password for internals e.g.
    #
    my ($type,$otherinfo) = split(/:/,$result);
    if($type =~ /^krb/) {
       $type = $result;
    }
    &Reply( $replyfd, "$type:\n", $userinput);
       }
     
       return 1;
   }
   &register_handler("currentauth", \&user_authorization_type, 1, 1, 0);
   
   #   Process a request by a manager to push a hosts or domain table 
   #   to us.  We pick apart the command and pass it on to the subs
   #   that already exist to do this.
   #
   # Parameters:
   #      $cmd    - the actual keyword that invoked us.
   #      $tail   - the tail of the request that invoked us.
   #      $client - File descriptor connected to the client
   #  Returns:
   #      1       - Ok to continue processing.
   #      0       - Program should exit
   # Implicit Output:
   #    a reply is written to the client.
   
   sub push_file_handler {
       my ($cmd, $tail, $client) = @_;
   
       my $userinput = "$cmd:$tail";
   
       # At this time we only know that the IP of our partner is a valid manager
       # the code below is a hook to do further authentication (e.g. to resolve
       # spoofing).
   
       my $cert = &GetCertificate($userinput);
       if(&ValidManager($cert)) { 
   
    # Now presumably we have the bona fides of both the peer host and the
    # process making the request.
         
    my $reply = &PushFile($userinput);
    &Reply($client, "$reply\n", $userinput);
   
       } else {
    &Failure( $client, "refused\n", $userinput);
       } 
       return 1;
   }
   &register_handler("pushfile", \&push_file_handler, 1, 0, 1);
   
   
   
   #   Process a reinit request.  Reinit requests that either
   #   lonc or lond be reinitialized so that an updated 
   #   host.tab or domain.tab can be processed.
   #
   # Parameters:
   #      $cmd    - the actual keyword that invoked us.
   #      $tail   - the tail of the request that invoked us.
   #      $client - File descriptor connected to the client
   #  Returns:
   #      1       - Ok to continue processing.
   #      0       - Program should exit
   #  Implicit output:
   #     a reply is sent to the client.
   #
   sub reinit_process_handler {
       my ($cmd, $tail, $client) = @_;
      
       my $userinput = "$cmd:$tail";
      
       my $cert = &GetCertificate($userinput);
       if(&ValidManager($cert)) {
    chomp($userinput);
    my $reply = &ReinitProcess($userinput);
    &Reply( $client,  "$reply\n", $userinput);
       } else {
    &Failure( $client, "refused\n", $userinput);
       }
       return 1;
   }
   
   &register_handler("reinit", \&reinit_process_handler, 1, 0, 1);
   
   #  Process the editing script for a table edit operation.
   #  the editing operation must be encrypted and requested by
   #  a manager host.
   #
   # Parameters:
   #      $cmd    - the actual keyword that invoked us.
   #      $tail   - the tail of the request that invoked us.
   #      $client - File descriptor connected to the client
   #  Returns:
   #      1       - Ok to continue processing.
   #      0       - Program should exit
   #  Implicit output:
   #     a reply is sent to the client.
   #
   sub edit_table_handler {
       my ($command, $tail, $client) = @_;
      
       my $userinput = "$command:$tail";
   
       my $cert = &GetCertificate($userinput);
       if(&ValidManager($cert)) {
    my($filetype, $script) = split(/:/, $tail);
    if (($filetype eq "hosts") || 
       ($filetype eq "domain")) {
       if($script ne "") {
    &Reply($client,              # BUGBUG - EditFile
         &EditFile($userinput), #   could fail.
         $userinput);
       } else {
    &Failure($client,"refused\n",$userinput);
       }
    } else {
       &Failure($client,"refused\n",$userinput);
    }
       } else {
    &Failure($client,"refused\n",$userinput);
       }
       return 1;
   }
   register_handler("edit", \&edit_table_handler, 1, 0, 1);
   
   
   #
   #   Authenticate a user against the LonCAPA authentication
   #   database.  Note that there are several authentication
   #   possibilities:
   #   - unix     - The user can be authenticated against the unix
   #                password file.
   #   - internal - The user can be authenticated against a purely 
   #                internal per user password file.
   #   - kerberos - The user can be authenticated against either a kerb4 or kerb5
   #                ticket granting authority.
   #   - user     - The person tailoring LonCAPA can supply a user authentication
   #                mechanism that is per system.
   #
   # Parameters:
   #    $cmd      - The command that got us here.
   #    $tail     - Tail of the command (remaining parameters).
   #    $client   - File descriptor connected to client.
   # Returns
   #     0        - Requested to exit, caller should shut down.
   #     1        - Continue processing.
   # Implicit inputs:
   #    The authentication systems describe above have their own forms of implicit
   #    input into the authentication process that are described above.
   #
   sub authenticate_handler {
       my ($cmd, $tail, $client) = @_;
   
       
       #  Regenerate the full input line 
       
       my $userinput  = $cmd.":".$tail;
       
       #  udom    - User's domain.
       #  uname   - Username.
       #  upass   - User's password.
       
       my ($udom,$uname,$upass)=split(/:/,$tail);
       &Debug(" Authenticate domain = $udom, user = $uname, password = $upass");
       chomp($upass);
       $upass=&unescape($upass);
   
       my $pwdcorrect = &validate_user($udom, $uname, $upass);
       if($pwdcorrect) {
    &Reply( $client, "authorized\n", $userinput);
    #
    #  Bad credentials: Failed to authorize
    #
       } else {
    &Failure( $client, "non_authorized\n", $userinput);
       }
   
       return 1;
   }
   
   register_handler("auth", \&authenticate_handler, 1, 1, 0);
   
   #
   #   Change a user's password.  Note that this function is complicated by
   #   the fact that a user may be authenticated in more than one way:
   #   At present, we are not able to change the password for all types of
   #   authentication methods.  Only for:
   #      unix    - unix password or shadow passoword style authentication.
   #      local   - Locally written authentication mechanism.
   #   For now, kerb4 and kerb5 password changes are not supported and result
   #   in an error.
   # FUTURE WORK:
   #    Support kerberos passwd changes?
   # Parameters:
   #    $cmd      - The command that got us here.
   #    $tail     - Tail of the command (remaining parameters).
   #    $client   - File descriptor connected to client.
   # Returns
   #     0        - Requested to exit, caller should shut down.
   #     1        - Continue processing.
   # Implicit inputs:
   #    The authentication systems describe above have their own forms of implicit
   #    input into the authentication process that are described above.
   sub change_password_handler {
       my ($cmd, $tail, $client) = @_;
   
       my $userinput = $cmd.":".$tail;           # Reconstruct client's string.
   
       #
       #  udom  - user's domain.
       #  uname - Username.
       #  upass - Current password.
       #  npass - New password.
      
       my ($udom,$uname,$upass,$npass)=split(/:/,$tail);
   
       $upass=&unescape($upass);
       $npass=&unescape($npass);
       &Debug("Trying to change password for $uname");
   
       # First require that the user can be authenticated with their
       # old password:
   
       my $validated = &validate_user($udom, $uname, $upass);
       if($validated) {
    my $realpasswd  = &get_auth_type($udom, $uname); # Defined since authd.
   
    my ($howpwd,$contentpwd)=split(/:/,$realpasswd);
    if ($howpwd eq 'internal') {
       &Debug("internal auth");
       my $salt=time;
       $salt=substr($salt,6,2);
       my $ncpass=crypt($npass,$salt);
       if(&rewrite_password_file($udom, $uname, "internal:$ncpass")) {
    &logthis("Result of password change for "
    ."$uname: pwchange_success");
    &Reply($client, "ok\n", $userinput);
       } else {
    &logthis("Unable to open $uname passwd "               
    ."to change password");
    &Failure( $client, "non_authorized\n",$userinput);
       }
    } elsif ($howpwd eq 'unix') {
       # Unix means we have to access /etc/password
       &Debug("auth is unix");
       my $execdir=$perlvar{'lonDaemons'};
       &Debug("Opening lcpasswd pipeline");
       my $pf = IO::File->new("|$execdir/lcpasswd > "
      ."$perlvar{'lonDaemons'}"
      ."/logs/lcpasswd.log");
       print $pf "$uname\n$npass\n$npass\n";
       close $pf;
       my $err = $?;
       my $result = ($err>0 ? 'pwchange_failure' : 'ok');
       &logthis("Result of password change for $uname: ".
        &lcpasswdstrerror($?));
       &Reply($client, "$result\n", $userinput);
    } else {
       # this just means that the current password mode is not
       # one we know how to change (e.g the kerberos auth modes or
       # locally written auth handler).
       #
       &Failure( $client, "auth_mode_error\n", $userinput);
    }  
   
       } else {
    &Failure( $client, "non_authorized\n", $userinput);
       }
   
       return 1;
   }
   register_handler("passwd", \&change_password_handler, 1, 1, 0);
   
   
   #---------------------------------------------------------------
   #
   #   Getting, decoding and dispatching requests:
   #
   
   #
   #   Get a Request:
   #   Gets a Request message from the client.  The transaction
   #   is defined as a 'line' of text.  We remove the new line
   #   from the text line.  
   #   
   sub get_request {
       my $input = <$client>;
       chomp($input);
   
       Debug("get_request: Request = $input\n");
   
       &status('Processing '.$clientname.':'.$input);
   
       return $input;
   }
   #---------------------------------------------------------------
   #
   #  Process a request.  This sub should shrink as each action
   #  gets farmed out into a separat sub that is registered 
   #  with the dispatch hash.  
   #
   # Parameters:
   #    user_input   - The request received from the client (lonc).
   # Returns:
   #    true to keep processing, false if caller should exit.
   #
   sub process_request {
       my ($userinput) = @_;      # Easier for now to break style than to
                                   # fix all the userinput -> user_input.
       my $wasenc    = 0; # True if request was encrypted.
   # ------------------------------------------------------------ See if encrypted
       if ($userinput =~ /^enc/) {
    $userinput = decipher($userinput);
    $wasenc=1;
    if(!$userinput) { # Cipher not defined.
       &Failure($client, "error: Encrypted data without negotated key");
       return 0;
    }
       }
       Debug("process_request: $userinput\n");
       
       #  
       #   The 'correct way' to add a command to lond is now to
       #   write a sub to execute it and Add it to the command dispatch
       #   hash via a call to register_handler..  The comments to that
       #   sub should give you enough to go on to show how to do this
       #   along with the examples that are building up as this code
       #   is getting refactored.   Until all branches of the
       #   if/elseif monster below have been factored out into
       #   separate procesor subs, if the dispatch hash is missing
       #   the command keyword, we will fall through to the remainder
       #   of the if/else chain below in order to keep this thing in 
       #   working order throughout the transmogrification.
   
       my ($command, $tail) = split(/:/, $userinput, 2);
       chomp($command);
       chomp($tail);
       $tail =~ s/(\r)//; # This helps people debugging with e.g. telnet.
       $command =~ s/(\r)//; # And this too for parameterless commands.
       if(!$tail) {
    $tail =""; # defined but blank.
       }
   
       &Debug("Command received: $command, encoded = $wasenc");
   
       if(defined $Dispatcher{$command}) {
   
    my $dispatch_info = $Dispatcher{$command};
    my $handler       = $$dispatch_info[0];
    my $need_encode   = $$dispatch_info[1];
    my $client_types  = $$dispatch_info[2];
    Debug("Matched dispatch hash: mustencode: $need_encode "
         ."ClientType $client_types");
         
    #  Validate the request:
         
    my $ok = 1;
    my $requesterprivs = 0;
    if(&isClient()) {
       $requesterprivs |= $CLIENT_OK;
    }
    if(&isManager()) {
       $requesterprivs |= $MANAGER_OK;
    }
    if($need_encode && (!$wasenc)) {
       Debug("Must encode but wasn't: $need_encode $wasenc");
       $ok = 0;
    }
    if(($client_types & $requesterprivs) == 0) {
       Debug("Client not privileged to do this operation");
       $ok = 0;
    }
   
    if($ok) {
       Debug("Dispatching to handler $command $tail");
       my $keep_going = &$handler($command, $tail, $client);
       return $keep_going;
    } else {
       Debug("Refusing to dispatch because client did not match requirements");
       Failure($client, "refused\n", $userinput);
       return 1;
    }
   
       }    
   
   #------------------- Commands not yet in spearate handlers. --------------
   
   
   
   # -------------------------------------------------------------------- makeuser
       if ($userinput =~ /^makeuser/) { # encoded and client.
    &Debug("Make user received");
    my $oldumask=umask(0077);
    if (($wasenc==1) && isClient) {
       my 
    ($cmd,$udom,$uname,$umode,$npass)=split(/:/,$userinput);
       &Debug("cmd =".$cmd." $udom =".$udom.
      " uname=".$uname);
       chomp($npass);
       $npass=&unescape($npass);
       my $proname=propath($udom,$uname);
       my $passfilename="$proname/passwd";
       &Debug("Password file created will be:".
      $passfilename);
       if (-e $passfilename) {
    print $client "already_exists\n";
       } elsif ($udom ne $currentdomainid) {
    print $client "not_right_domain\n";
       } else {
    my @fpparts=split(/\//,$proname);
    my $fpnow=$fpparts[0].'/'.$fpparts[1].'/'.$fpparts[2];
    my $fperror='';
    for (my $i=3;$i<=$#fpparts;$i++) {
       $fpnow.='/'.$fpparts[$i]; 
       unless (-e $fpnow) {
    unless (mkdir($fpnow,0777)) {
       $fperror="error: ".($!+0)
    ." mkdir failed while attempting "
    ."makeuser";
    }
       }
    }
    unless ($fperror) {
       my $result=&make_passwd_file($uname, $umode,$npass,
    $passfilename);
       print $client $result;
    } else {
       print $client "$fperror\n";
    }
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
    umask($oldumask);
   # -------------------------------------------------------------- changeuserauth
       } elsif ($userinput =~ /^changeuserauth/) { # encoded & client
    &Debug("Changing authorization");
    if (($wasenc==1) && isClient) {
       my 
    ($cmd,$udom,$uname,$umode,$npass)=split(/:/,$userinput);
       chomp($npass);
       &Debug("cmd = ".$cmd." domain= ".$udom.
      "uname =".$uname." umode= ".$umode);
       $npass=&unescape($npass);
       my $proname=&propath($udom,$uname);
       my $passfilename="$proname/passwd";
       if ($udom ne $currentdomainid) {
    print $client "not_right_domain\n";
       } else {
    my $result=&make_passwd_file($uname, $umode,$npass,
        $passfilename);
    Reply($client, $result, $userinput);
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ------------------------------------------------------------------------ home
       } elsif ($userinput =~ /^home/) { # client clear or encoded
    if(isClient) {
       my ($cmd,$udom,$uname)=split(/:/,$userinput);
       chomp($uname);
       my $proname=propath($udom,$uname);
       if (-e $proname) {
    print $client "found\n";
       } else {
    print $client "not_found\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ---------------------------------------------------------------------- update
       } elsif ($userinput =~ /^update/) { # client clear or encoded.
    if(isClient) {
       my ($cmd,$fname)=split(/:/,$userinput);
       my $ownership=ishome($fname);
       if ($ownership eq 'not_owner') {
    if (-e $fname) {
       my ($dev,$ino,$mode,$nlink,
    $uid,$gid,$rdev,$size,
    $atime,$mtime,$ctime,
    $blksize,$blocks)=stat($fname);
       my $now=time;
       my $since=$now-$atime;
       if ($since>$perlvar{'lonExpire'}) {
    my $reply=
       &reply("unsub:$fname","$clientname");
       unlink("$fname");
       } else {
    my $transname="$fname.in.transfer";
    my $remoteurl=
       &reply("sub:$fname","$clientname");
    my $response;
    {
       my $ua=new LWP::UserAgent;
       my $request=new HTTP::Request('GET',"$remoteurl");
       $response=$ua->request($request,$transname);
    }
    if ($response->is_error()) {
       unlink($transname);
       my $message=$response->status_line;
       &logthis(
        "LWP GET: $message for $fname ($remoteurl)");
    } else {
       if ($remoteurl!~/\.meta$/) {
    my $ua=new LWP::UserAgent;
    my $mrequest=
       new HTTP::Request('GET',$remoteurl.'.meta');
    my $mresponse=
       $ua->request($mrequest,$fname.'.meta');
    if ($mresponse->is_error()) {
       unlink($fname.'.meta');
    }
       }
       rename($transname,$fname);
    }
       }
       print $client "ok\n";
    } else {
       print $client "not_found\n";
    }
       } else {
    print $client "rejected\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # -------------------------------------- fetch a user file from a remote server
       } elsif ($userinput =~ /^fetchuserfile/) { # Client clear or enc.
    if(isClient) {
       my ($cmd,$fname)=split(/:/,$userinput);
       my ($udom,$uname,$ufile) = ($fname =~ m|^([^/]+)/([^/]+)/(.+)$|);
       my $udir=propath($udom,$uname).'/userfiles';
       unless (-e $udir) { mkdir($udir,0770); }
       if (-e $udir) {
    $ufile=~s/^[\.\~]+//;
    my $path = $udir;
    if ($ufile =~m|(.+)/([^/]+)$|) {
       my @parts=split('/',$1);
       foreach my $part (@parts) {
    $path .= '/'.$part;
    if ((-e $path)!=1) {
       mkdir($path,0770);
    }
       }
    }
    my $destname=$udir.'/'.$ufile;
    my $transname=$udir.'/'.$ufile.'.in.transit';
    my $remoteurl='http://'.$clientip.'/userfiles/'.$fname;
    my $response;
    {
       my $ua=new LWP::UserAgent;
       my $request=new HTTP::Request('GET',"$remoteurl");
       $response=$ua->request($request,$transname);
    }
    if ($response->is_error()) {
       unlink($transname);
       my $message=$response->status_line;
       &logthis("LWP GET: $message for $fname ($remoteurl)");
       print $client "failed\n";
    } else {
       if (!rename($transname,$destname)) {
    &logthis("Unable to move $transname to $destname");
    unlink($transname);
    print $client "failed\n";
       } else {
    print $client "ok\n";
       }
    }
       } else {
    print $client "not_home\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
    }
   # --------------------------------------------------------- remove a user file 
       } elsif ($userinput =~ /^removeuserfile/) { # Client clear or enc.
    if(isClient) {
       my ($cmd,$fname)=split(/:/,$userinput);
       my ($udom,$uname,$ufile) = ($fname =~ m|^([^/]+)/([^/]+)/(.+)$|);
       &logthis("$udom - $uname - $ufile");
       if ($ufile =~m|/\.\./|) {
    # any files paths with /../ in them refuse 
    # to deal with
    print $client "refused\n";
       } else {
    my $udir=propath($udom,$uname);
    if (-e $udir) {
       my $file=$udir.'/userfiles/'.$ufile;
       if (-e $file) {
    unlink($file);
    if (-e $file) {
       print $client "failed\n";
    } else {
       print $client "ok\n";
    }
       } else {
    print $client "not_found\n";
       }
    } else {
       print $client "not_home\n";
    }
       }
    } else {
       Reply($client, "refused\n", $userinput);
    }
   # ------------------------------------------ authenticate access to a user file
       } elsif ($userinput =~ /^tokenauthuserfile/) { # Client only
    if(isClient) {
       my ($cmd,$fname,$session)=split(/:/,$userinput);
       chomp($session);
       my $reply='non_auth';
       if (open(ENVIN,$perlvar{'lonIDsDir'}.'/'.
        $session.'.id')) {
    while (my $line=<ENVIN>) {
       if ($line=~ m|userfile\.\Q$fname\E\=|) { $reply='ok'; }
       }
    close(ENVIN);
    print $client $reply."\n";
       } else {
    print $client "invalid_token\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ----------------------------------------------------------------- unsubscribe
       } elsif ($userinput =~ /^unsub/) {
    if(isClient) {
       my ($cmd,$fname)=split(/:/,$userinput);
       if (-e $fname) {
    print $client &unsub($fname,$clientip);
       } else {
    print $client "not_found\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ------------------------------------------------------------------- subscribe
       } elsif ($userinput =~ /^sub/) {
    if(isClient) {
       print $client &subscribe($userinput,$clientip);
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ------------------------------------------------------------- current version
       } elsif ($userinput =~ /^currentversion/) {
    if(isClient) {
       my ($cmd,$fname)=split(/:/,$userinput);
       print $client &currentversion($fname)."\n";
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ------------------------------------------------------------------------- log
       } elsif ($userinput =~ /^log/) {
    if(isClient) {
       my ($cmd,$udom,$uname,$what)=split(/:/,$userinput);
       chomp($what);
       my $proname=propath($udom,$uname);
       my $now=time;
       {
    my $hfh;
    if ($hfh=IO::File->new(">>$proname/activity.log")) { 
       print $hfh "$now:$clientname:$what\n";
       print $client "ok\n"; 
    } else {
       print $client "error: ".($!+0)
    ." IO::File->new Failed "
    ."while attempting log\n";
    }
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ------------------------------------------------------------------------- put
       } elsif ($userinput =~ /^put/) {
    if(isClient) {
       my ($cmd,$udom,$uname,$namespace,$what)
    =split(/:/,$userinput,5);
       $namespace=~s/\//\_/g;
       $namespace=~s/\W//g;
       if ($namespace ne 'roles') {
    chomp($what);
    my $proname=propath($udom,$uname);
    my $now=time;
    my @pairs=split(/\&/,$what);
    my %hash;
    if (tie(%hash,'GDBM_File',
    "$proname/$namespace.db",
    &GDBM_WRCREAT(),0640)) {
       unless ($namespace=~/^nohist\_/) {
    my $hfh;
    if ($hfh=IO::File->new(">>$proname/$namespace.hist")) { print $hfh "P:$now:$what\n"; }
       }
       
       foreach my $pair (@pairs) {
    my ($key,$value)=split(/=/,$pair);
    $hash{$key}=$value;
       }
       if (untie(%hash)) {
    print $client "ok\n";
       } else {
    print $client "error: ".($!+0)
       ." untie(GDBM) failed ".
       "while attempting put\n";
       }
    } else {
       print $client "error: ".($!)
    ." tie(GDBM) Failed ".
    "while attempting put\n";
    }
       } else {
    print $client "refused\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ------------------------------------------------------------------- inc
       } elsif ($userinput =~ /^inc:/) {
    if(isClient) {
       my ($cmd,$udom,$uname,$namespace,$what)
    =split(/:/,$userinput);
       $namespace=~s/\//\_/g;
       $namespace=~s/\W//g;
       if ($namespace ne 'roles') {
    chomp($what);
    my $proname=propath($udom,$uname);
    my $now=time;
    my @pairs=split(/\&/,$what);
    my %hash;
    if (tie(%hash,'GDBM_File',
    "$proname/$namespace.db",
    &GDBM_WRCREAT(),0640)) {
       unless ($namespace=~/^nohist\_/) {
    my $hfh;
    if ($hfh=IO::File->new(">>$proname/$namespace.hist")) { print $hfh "P:$now:$what\n"; }
       }
       foreach my $pair (@pairs) {
    my ($key,$value)=split(/=/,$pair);
    # We could check that we have a number...
    if (! defined($value) || $value eq '') {
       $value = 1;
    }
    $hash{$key}+=$value;
       }
       if (untie(%hash)) {
    print $client "ok\n";
       } else {
    print $client "error: ".($!+0)
       ." untie(GDBM) failed ".
       "while attempting inc\n";
       }
    } else {
       print $client "error: ".($!)
    ." tie(GDBM) Failed ".
    "while attempting inc\n";
    }
       } else {
    print $client "refused\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # -------------------------------------------------------------------- rolesput
       } elsif ($userinput =~ /^rolesput/) {
    if(isClient) {
       &Debug("rolesput");
       if ($wasenc==1) {
    my ($cmd,$exedom,$exeuser,$udom,$uname,$what)
       =split(/:/,$userinput);
    &Debug("cmd = ".$cmd." exedom= ".$exedom.
          "user = ".$exeuser." udom=".$udom.
          "what = ".$what);
    my $namespace='roles';
    chomp($what);
    my $proname=propath($udom,$uname);
    my $now=time;
    my @pairs=split(/\&/,$what);
    my %hash;
    if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT(),0640)) {
       {
    my $hfh;
    if ($hfh=IO::File->new(">>$proname/$namespace.hist")) { 
       print $hfh "P:$now:$exedom:$exeuser:$what\n";
    }
       }
       
       foreach my $pair (@pairs) {
    my ($key,$value)=split(/=/,$pair);
    &ManagePermissions($key, $udom, $uname,
      &get_auth_type( $udom, 
    $uname));
    $hash{$key}=$value;
       }
       if (untie(%hash)) {
    print $client "ok\n";
       } else {
    print $client "error: ".($!+0)
       ." untie(GDBM) Failed ".
       "while attempting rolesput\n";
       }
    } else {
       print $client "error: ".($!+0)
    ." tie(GDBM) Failed ".
    "while attempting rolesput\n";
       }
       } else {
    print $client "refused\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # -------------------------------------------------------------------- rolesdel
       } elsif ($userinput =~ /^rolesdel/) {
    if(isClient) {
       &Debug("rolesdel");
       if ($wasenc==1) {
    my ($cmd,$exedom,$exeuser,$udom,$uname,$what)
       =split(/:/,$userinput);
    &Debug("cmd = ".$cmd." exedom= ".$exedom.
          "user = ".$exeuser." udom=".$udom.
          "what = ".$what);
    my $namespace='roles';
    chomp($what);
    my $proname=propath($udom,$uname);
    my $now=time;
    my @rolekeys=split(/\&/,$what);
    my %hash;
    if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT(),0640)) {
       {
    my $hfh;
    if ($hfh=IO::File->new(">>$proname/$namespace.hist")) { 
       print $hfh "D:$now:$exedom:$exeuser:$what\n";
    }
       }
       foreach my $key (@rolekeys) {
    delete $hash{$key};
       }
       if (untie(%hash)) {
    print $client "ok\n";
       } else {
    print $client "error: ".($!+0)
       ." untie(GDBM) Failed ".
       "while attempting rolesdel\n";
       }
    } else {
       print $client "error: ".($!+0)
    ." tie(GDBM) Failed ".
    "while attempting rolesdel\n";
    }
       } else {
    print $client "refused\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ------------------------------------------------------------------------- get
       } elsif ($userinput =~ /^get/) {
    if(isClient) {
       my ($cmd,$udom,$uname,$namespace,$what)
    =split(/:/,$userinput);
       $namespace=~s/\//\_/g;
       $namespace=~s/\W//g;
       chomp($what);
       my @queries=split(/\&/,$what);
       my $proname=propath($udom,$uname);
       my $qresult='';
       my %hash;
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) {
    for (my $i=0;$i<=$#queries;$i++) {
       $qresult.="$hash{$queries[$i]}&";
    }
    if (untie(%hash)) {
       $qresult=~s/\&$//;
       print $client "$qresult\n";
    } else {
       print $client "error: ".($!+0)
    ." untie(GDBM) Failed ".
    "while attempting get\n";
    }
       } else {
    if ($!+0 == 2) {
       print $client "error:No such file or ".
    "GDBM reported bad block error\n";
    } else {
       print $client "error: ".($!+0)
    ." tie(GDBM) Failed ".
    "while attempting get\n";
    }
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ------------------------------------------------------------------------ eget
       } elsif ($userinput =~ /^eget/) {
    if (isClient) {
       my ($cmd,$udom,$uname,$namespace,$what)
    =split(/:/,$userinput);
       $namespace=~s/\//\_/g;
       $namespace=~s/\W//g;
       chomp($what);
       my @queries=split(/\&/,$what);
       my $proname=propath($udom,$uname);
       my $qresult='';
       my %hash;
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) {
    for (my $i=0;$i<=$#queries;$i++) {
       $qresult.="$hash{$queries[$i]}&";
    }
    if (untie(%hash)) {
       $qresult=~s/\&$//;
       if ($cipher) {
    my $cmdlength=length($qresult);
    $qresult.="         ";
    my $encqresult='';
    for 
       (my $encidx=0;$encidx<=$cmdlength;$encidx+=8) {
    $encqresult.=
       unpack("H16",
      $cipher->encrypt(substr($qresult,$encidx,8)));
       }
    print $client "enc:$cmdlength:$encqresult\n";
       } else {
    print $client "error:no_key\n";
       }
    } else {
       print $client "error: ".($!+0)
    ." untie(GDBM) Failed ".
    "while attempting eget\n";
    }
       } else {
    print $client "error: ".($!+0)
       ." tie(GDBM) Failed ".
       "while attempting eget\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ------------------------------------------------------------------------- del
       } elsif ($userinput =~ /^del/) {
    if(isClient) {
       my ($cmd,$udom,$uname,$namespace,$what)
    =split(/:/,$userinput);
       $namespace=~s/\//\_/g;
       $namespace=~s/\W//g;
       chomp($what);
       my $proname=propath($udom,$uname);
       my $now=time;
       my @keys=split(/\&/,$what);
       my %hash;
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT(),0640)) {
    unless ($namespace=~/^nohist\_/) {
       my $hfh;
       if ($hfh=IO::File->new(">>$proname/$namespace.hist")) { print $hfh "D:$now:$what\n"; }
    }
    foreach my $key (@keys) {
       delete($hash{$key});
    }
    if (untie(%hash)) {
       print $client "ok\n";
    } else {
       print $client "error: ".($!+0)
    ." untie(GDBM) Failed ".
    "while attempting del\n";
    }
       } else {
    print $client "error: ".($!+0)
       ." tie(GDBM) Failed ".
       "while attempting del\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ------------------------------------------------------------------------ keys
       } elsif ($userinput =~ /^keys/) {
    if(isClient) {
       my ($cmd,$udom,$uname,$namespace)
    =split(/:/,$userinput);
       $namespace=~s/\//\_/g;
       $namespace=~s/\W//g;
       my $proname=propath($udom,$uname);
       my $qresult='';
       my %hash;
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) {
    foreach my $key (keys %hash) {
       $qresult.="$key&";
    }
    if (untie(%hash)) {
       $qresult=~s/\&$//;
       print $client "$qresult\n";
    } else {
       print $client "error: ".($!+0)
    ." untie(GDBM) Failed ".
    "while attempting keys\n";
    }
       } else {
    print $client "error: ".($!+0)
       ." tie(GDBM) Failed ".
       "while attempting keys\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ----------------------------------------------------------------- dumpcurrent
       } elsif ($userinput =~ /^currentdump/) {
    if (isClient) {
       my ($cmd,$udom,$uname,$namespace)
    =split(/:/,$userinput);
       $namespace=~s/\//\_/g;
       $namespace=~s/\W//g;
       my $qresult='';
       my $proname=propath($udom,$uname);
       my %hash;
       if (tie(%hash,'GDBM_File',
       "$proname/$namespace.db",
       &GDBM_READER(),0640)) {
       # Structure of %data:
    # $data{$symb}->{$parameter}=$value;
    # $data{$symb}->{'v.'.$parameter}=$version;
    # since $parameter will be unescaped, we do not
    # have to worry about silly parameter names...
    my %data = ();
    while (my ($key,$value) = each(%hash)) {
       my ($v,$symb,$param) = split(/:/,$key);
       next if ($v eq 'version' || $symb eq 'keys');
       next if (exists($data{$symb}) && 
        exists($data{$symb}->{$param}) &&
        $data{$symb}->{'v.'.$param} > $v);
       $data{$symb}->{$param}=$value;
       $data{$symb}->{'v.'.$param}=$v;
    }
    if (untie(%hash)) {
       while (my ($symb,$param_hash) = each(%data)) {
    while(my ($param,$value) = each (%$param_hash)){
       next if ($param =~ /^v\./);
       $qresult.=$symb.':'.$param.'='.$value.'&';
    }
       }
       chop($qresult);
       print $client "$qresult\n";
    } else {
       print $client "error: ".($!+0)
    ." untie(GDBM) Failed ".
    "while attempting currentdump\n";
    }
       } else {
    print $client "error: ".($!+0)
       ." tie(GDBM) Failed ".
       "while attempting currentdump\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
    }
   # ------------------------------------------------------------------------ dump
       } elsif ($userinput =~ /^dump/) {
    if(isClient) {
       my ($cmd,$udom,$uname,$namespace,$regexp)
    =split(/:/,$userinput);
       $namespace=~s/\//\_/g;
       $namespace=~s/\W//g;
       if (defined($regexp)) {
    $regexp=&unescape($regexp);
       } else {
    $regexp='.';
       }
       my $qresult='';
       my $proname=propath($udom,$uname);
       my %hash;
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) {
    while (my ($key,$value) = each(%hash)) {
       if ($regexp eq '.') {
    $qresult.=$key.'='.$value.'&';
       } else {
    my $unescapeKey = &unescape($key);
    if (eval('$unescapeKey=~/$regexp/')) {
       $qresult.="$key=$value&";
    }
       }
    }
    if (untie(%hash)) {
       chop($qresult);
       print $client "$qresult\n";
    } else {
       print $client "error: ".($!+0)
    ." untie(GDBM) Failed ".
    "while attempting dump\n";
    }
       } else {
    print $client "error: ".($!+0)
       ." tie(GDBM) Failed ".
       "while attempting dump\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ----------------------------------------------------------------------- store
       } elsif ($userinput =~ /^store/) {
    if(isClient) {
       my ($cmd,$udom,$uname,$namespace,$rid,$what)
    =split(/:/,$userinput);
       $namespace=~s/\//\_/g;
       $namespace=~s/\W//g;
       if ($namespace ne 'roles') {
    chomp($what);
    my $proname=propath($udom,$uname);
    my $now=time;
    my @pairs=split(/\&/,$what);
    my %hash;
    if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT(),0640)) {
       unless ($namespace=~/^nohist\_/) {
    my $hfh;
    if ($hfh=IO::File->new(">>$proname/$namespace.hist")) {
       print $hfh "P:$now:$rid:$what\n";
    }
       }
       my @previouskeys=split(/&/,$hash{"keys:$rid"});
       my $key;
       $hash{"version:$rid"}++;
       my $version=$hash{"version:$rid"};
       my $allkeys=''; 
       foreach my $pair (@pairs) {
    my ($key,$value)=split(/=/,$pair);
    $allkeys.=$key.':';
    $hash{"$version:$rid:$key"}=$value;
       }
       $hash{"$version:$rid:timestamp"}=$now;
       $allkeys.='timestamp';
       $hash{"$version:keys:$rid"}=$allkeys;
       if (untie(%hash)) {
    print $client "ok\n";
       } else {
    print $client "error: ".($!+0)
       ." untie(GDBM) Failed ".
       "while attempting store\n";
    }
    } else {
       print $client "error: ".($!+0)
    ." tie(GDBM) Failed ".
    "while attempting store\n";
    }
       } else {
    print $client "refused\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # --------------------------------------------------------------------- restore
       } elsif ($userinput =~ /^restore/) {
    if(isClient) {
       my ($cmd,$udom,$uname,$namespace,$rid)
    =split(/:/,$userinput);
       $namespace=~s/\//\_/g;
       $namespace=~s/\W//g;
       chomp($rid);
       my $proname=propath($udom,$uname);
       my $qresult='';
       my %hash;
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) {
    my $version=$hash{"version:$rid"};
    $qresult.="version=$version&";
    my $scope;
    for ($scope=1;$scope<=$version;$scope++) {
       my $vkeys=$hash{"$scope:keys:$rid"};
       my @keys=split(/:/,$vkeys);
       my $key;
       $qresult.="$scope:keys=$vkeys&";
       foreach $key (@keys) {
    $qresult.="$scope:$key=".$hash{"$scope:$rid:$key"}."&";
       }                                  
    }
    if (untie(%hash)) {
       $qresult=~s/\&$//;
       print $client "$qresult\n";
    } else {
       print $client "error: ".($!+0)
    ." untie(GDBM) Failed ".
    "while attempting restore\n";
    }
       } else {
    print $client "error: ".($!+0)
       ." tie(GDBM) Failed ".
       "while attempting restore\n";
       }
    } else  {
       Reply($client, "refused\n", $userinput);
       
    }
   # -------------------------------------------------------------------- chatsend
       } elsif ($userinput =~ /^chatsend/) {
    if(isClient) {
       my ($cmd,$cdom,$cnum,$newpost)=split(/\:/,$userinput);
       &chatadd($cdom,$cnum,$newpost);
       print $client "ok\n";
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # -------------------------------------------------------------------- chatretr
       } elsif ($userinput =~ /^chatretr/) {
    if(isClient) {
       my 
    ($cmd,$cdom,$cnum,$udom,$uname)=split(/\:/,$userinput);
       my $reply='';
       foreach (&getchat($cdom,$cnum,$udom,$uname)) {
    $reply.=&escape($_).':';
       }
       $reply=~s/\:$//;
       print $client $reply."\n";
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ------------------------------------------------------------------- querysend
       } elsif ($userinput =~ /^querysend/) {
    if (isClient) {
       my ($cmd,$query,
    $arg1,$arg2,$arg3)=split(/\:/,$userinput);
       $query=~s/\n*$//g;
       print $client "".
    sqlreply("$clientname\&$query".
    "\&$arg1"."\&$arg2"."\&$arg3")."\n";
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ------------------------------------------------------------------ queryreply
       } elsif ($userinput =~ /^queryreply/) {
    if(isClient) {
       my ($cmd,$id,$reply)=split(/:/,$userinput); 
       my $store;
       my $execdir=$perlvar{'lonDaemons'};
       if ($store=IO::File->new(">$execdir/tmp/$id")) {
    $reply=~s/\&/\n/g;
    print $store $reply;
    close $store;
    my $store2=IO::File->new(">$execdir/tmp/$id.end");
    print $store2 "done\n";
    close $store2;
    print $client "ok\n";
       } else {
    print $client "error: ".($!+0)
       ." IO::File->new Failed ".
       "while attempting queryreply\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ----------------------------------------------------------------- courseidput
       } elsif ($userinput =~ /^courseidput/) {
    if(isClient) {
       my ($cmd,$udom,$what)=split(/:/,$userinput);
       chomp($what);
    $udom=~s/\W//g;
       my $proname=
    "$perlvar{'lonUsersDir'}/$udom/nohist_courseids";
       my $now=time;
       my @pairs=split(/\&/,$what);
       my %hash;
       if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_WRCREAT(),0640)) {
    foreach my $pair (@pairs) {
       my ($key,$descr,$inst_code)=split(/=/,$pair);
       $hash{$key}=$descr.':'.$inst_code.':'.$now;
    }
    if (untie(%hash)) {
       print $client "ok\n";
    } else {
       print $client "error: ".($!+0)
    ." untie(GDBM) Failed ".
    "while attempting courseidput\n";
    }
       } else {
    print $client "error: ".($!+0)
       ." tie(GDBM) Failed ".
       "while attempting courseidput\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ---------------------------------------------------------------- courseiddump
       } elsif ($userinput =~ /^courseiddump/) {
    if(isClient) {
       my ($cmd,$udom,$since,$description)
    =split(/:/,$userinput);
       if (defined($description)) {
    $description=&unescape($description);
       } else {
    $description='.';
       }
       unless (defined($since)) { $since=0; }
       my $qresult='';
       my $proname=
    "$perlvar{'lonUsersDir'}/$udom/nohist_courseids";
       my %hash;
       if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_READER(),0640)) {
    while (my ($key,$value) = each(%hash)) {
       my ($descr,$lasttime,$inst_code);
       if ($value =~ m/^([^\:]*):([^\:]*):(\d+)$/) {
    ($descr,$inst_code,$lasttime)=($1,$2,$3);
       } else {
    ($descr,$lasttime) = split(/\:/,$value);
       }
       if ($lasttime<$since) { next; }
       if ($description eq '.') {
    $qresult.=$key.'='.$descr.':'.$inst_code.'&';
       } else {
    my $unescapeVal = &unescape($descr);
    if (eval('$unescapeVal=~/\Q$description\E/i')) {
       $qresult.=$key.'='.$descr.':'.$inst_code.'&';
    }
       }
    }
    if (untie(%hash)) {
       chop($qresult);
       print $client "$qresult\n";
    } else {
       print $client "error: ".($!+0)
    ." untie(GDBM) Failed ".
    "while attempting courseiddump\n";
    }
       } else {
    print $client "error: ".($!+0)
       ." tie(GDBM) Failed ".
       "while attempting courseiddump\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ----------------------------------------------------------------------- idput
       } elsif ($userinput =~ /^idput/) {
    if(isClient) {
       my ($cmd,$udom,$what)=split(/:/,$userinput);
       chomp($what);
       $udom=~s/\W//g;
       my $proname="$perlvar{'lonUsersDir'}/$udom/ids";
       my $now=time;
       my @pairs=split(/\&/,$what);
       my %hash;
       if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_WRCREAT(),0640)) {
    {
       my $hfh;
       if ($hfh=IO::File->new(">>$proname.hist")) {
    print $hfh "P:$now:$what\n";
       }
    }
    foreach my $pair (@pairs) {
       my ($key,$value)=split(/=/,$pair);
       $hash{$key}=$value;
    }
    if (untie(%hash)) {
       print $client "ok\n";
    } else {
       print $client "error: ".($!+0)
    ." untie(GDBM) Failed ".
    "while attempting idput\n";
    }
       } else {
    print $client "error: ".($!+0)
       ." tie(GDBM) Failed ".
       "while attempting idput\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ----------------------------------------------------------------------- idget
       } elsif ($userinput =~ /^idget/) {
    if(isClient) {
       my ($cmd,$udom,$what)=split(/:/,$userinput);
       chomp($what);
       $udom=~s/\W//g;
       my $proname="$perlvar{'lonUsersDir'}/$udom/ids";
       my @queries=split(/\&/,$what);
       my $qresult='';
       my %hash;
       if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_READER(),0640)) {
    for (my $i=0;$i<=$#queries;$i++) {
       $qresult.="$hash{$queries[$i]}&";
    }
    if (untie(%hash)) {
       $qresult=~s/\&$//;
       print $client "$qresult\n";
    } else {
       print $client "error: ".($!+0)
    ." untie(GDBM) Failed ".
    "while attempting idget\n";
    }
       } else {
    print $client "error: ".($!+0)
       ." tie(GDBM) Failed ".
       "while attempting idget\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ---------------------------------------------------------------------- tmpput
       } elsif ($userinput =~ /^tmpput/) {
    if(isClient) {
       my ($cmd,$what)=split(/:/,$userinput);
       my $store;
       $tmpsnum++;
       my $id=$$.'_'.$clientip.'_'.$tmpsnum;
       $id=~s/\W/\_/g;
       $what=~s/\n//g;
       my $execdir=$perlvar{'lonDaemons'};
       if ($store=IO::File->new(">$execdir/tmp/$id.tmp")) {
    print $store $what;
    close $store;
    print $client "$id\n";
       }
       else {
    print $client "error: ".($!+0)
       ."IO::File->new Failed ".
       "while attempting tmpput\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   
   # ---------------------------------------------------------------------- tmpget
       } elsif ($userinput =~ /^tmpget/) {
    if(isClient) {
       my ($cmd,$id)=split(/:/,$userinput);
       chomp($id);
       $id=~s/\W/\_/g;
       my $store;
       my $execdir=$perlvar{'lonDaemons'};
       if ($store=IO::File->new("$execdir/tmp/$id.tmp")) {
    my $reply=<$store>;
       print $client "$reply\n";
    close $store;
       }
       else {
    print $client "error: ".($!+0)
       ."IO::File->new Failed ".
       "while attempting tmpget\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ---------------------------------------------------------------------- tmpdel
       } elsif ($userinput =~ /^tmpdel/) {
    if(isClient) {
       my ($cmd,$id)=split(/:/,$userinput);
       chomp($id);
       $id=~s/\W/\_/g;
       my $execdir=$perlvar{'lonDaemons'};
       if (unlink("$execdir/tmp/$id.tmp")) {
    print $client "ok\n";
       } else {
    print $client "error: ".($!+0)
       ."Unlink tmp Failed ".
       "while attempting tmpdel\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ----------------------------------------- portfolio directory list (portls)
       } elsif ($userinput =~ /^portls/) {
    if(isClient) {
       my ($cmd,$uname,$udom)=split(/:/,$userinput);
       my $udir=propath($udom,$uname).'/userfiles/portfolio';
       my $dirLine='';
       my $dirContents='';
       if (opendir(LSDIR,$udir.'/')){
    while ($dirLine = readdir(LSDIR)){
       $dirContents = $dirContents.$dirLine.'<br />';
    }
       } else {
    $dirContents = "No directory found\n";
       }
       print $client $dirContents."\n";
    } else {
       Reply($client, "refused\n", $userinput);
    }
   # -------------------------------------------------------------------------- ls
       } elsif ($userinput =~ /^ls/) {
    if(isClient) {
       my $obs;
       my $rights;
       my ($cmd,$ulsdir)=split(/:/,$userinput);
       my $ulsout='';
       my $ulsfn;
       if (-e $ulsdir) {
    if(-d $ulsdir) {
       if (opendir(LSDIR,$ulsdir)) {
    while ($ulsfn=readdir(LSDIR)) {
       undef $obs, $rights; 
       my @ulsstats=stat($ulsdir.'/'.$ulsfn);
       #We do some obsolete checking here
       if(-e $ulsdir.'/'.$ulsfn.".meta") { 
    open(FILE, $ulsdir.'/'.$ulsfn.".meta");
    my @obsolete=<FILE>;
    foreach my $obsolete (@obsolete) {
       if($obsolete =~ m|(<obsolete>)(on)|) { $obs = 1; } 
       if($obsolete =~ m|(<copyright>)(default)|) { $rights = 1; }
    }
       }
       $ulsout.=$ulsfn.'&'.join('&',@ulsstats);
       if($obs eq '1') { $ulsout.="&1"; }
       else { $ulsout.="&0"; }
       if($rights eq '1') { $ulsout.="&1:"; }
       else { $ulsout.="&0:"; }
    }
    closedir(LSDIR);
       }
    } else {
       my @ulsstats=stat($ulsdir);
       $ulsout.=$ulsfn.'&'.join('&',@ulsstats).':';
    }
       } else {
    $ulsout='no_such_dir';
       }
       if ($ulsout eq '') { $ulsout='empty'; }
       print $client "$ulsout\n";
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ----------------------------------------------------------------- setannounce
       } elsif ($userinput =~ /^setannounce/) {
    if (isClient) {
       my ($cmd,$announcement)=split(/:/,$userinput);
       chomp($announcement);
       $announcement=&unescape($announcement);
       if (my $store=IO::File->new('>'.$perlvar{'lonDocRoot'}.
    '/announcement.txt')) {
    print $store $announcement;
    close $store;
    print $client "ok\n";
       } else {
    print $client "error: ".($!+0)."\n";
       }
    } else {
       Reply($client, "refused\n", $userinput);
       
    }
   # ------------------------------------------------------------------ Hanging up
       } elsif (($userinput =~ /^exit/) ||
        ($userinput =~ /^init/)) { # no restrictions.
    &logthis(
    "Client $clientip ($clientname) hanging up: $userinput");
    print $client "bye\n";
    $client->shutdown(2);        # shutdown the socket forcibly.
    $client->close();
    return 0;
   
   # ---------------------------------- set current host/domain
       } elsif ($userinput =~ /^sethost:/) {
    if (isClient) {
       print $client &sethost($userinput)."\n";
    } else {
       print $client "refused\n";
    }
   #---------------------------------- request file (?) version.
       } elsif ($userinput =~/^version:/) {
    if (isClient) {
       print $client &version($userinput)."\n";
    } else {
       print $client "refused\n";
    }
   #------------------------------- is auto-enrollment enabled?
       } elsif ($userinput =~/^autorun:/) {
    if (isClient) {
       my ($cmd,$cdom) = split(/:/,$userinput);
       my $outcome = &localenroll::run($cdom);
       print $client "$outcome\n";
    } else {
       print $client "0\n";
    }
   #------------------------------- get official sections (for auto-enrollment).
       } elsif ($userinput =~/^autogetsections:/) {
    if (isClient) {
       my ($cmd,$coursecode,$cdom)=split(/:/,$userinput);
       my @secs = &localenroll::get_sections($coursecode,$cdom);
       my $seclist = &escape(join(':',@secs));
       print $client "$seclist\n";
    } else {
       print $client "refused\n";
    }
   #----------------------- validate owner of new course section (for auto-enrollment).
       } elsif ($userinput =~/^autonewcourse:/) {
    if (isClient) {
       my ($cmd,$inst_course_id,$owner,$cdom)=split(/:/,$userinput);
       my $outcome = &localenroll::new_course($inst_course_id,$owner,$cdom);
       print $client "$outcome\n";
    } else {
       print $client "refused\n";
    }
   #-------------- validate course section in schedule of classes (for auto-enrollment).
       } elsif ($userinput =~/^autovalidatecourse:/) {
    if (isClient) {
       my ($cmd,$inst_course_id,$cdom)=split(/:/,$userinput);
       my $outcome=&localenroll::validate_courseID($inst_course_id,$cdom);
       print $client "$outcome\n";
    } else {
       print $client "refused\n";
    }
   #--------------------------- create password for new user (for auto-enrollment).
       } elsif ($userinput =~/^autocreatepassword:/) {
    if (isClient) {
       my ($cmd,$authparam,$cdom)=split(/:/,$userinput);
       my ($create_passwd,$authchk);
       ($authparam,$create_passwd,$authchk) = &localenroll::create_password($authparam,$cdom);
       print $client &escape($authparam.':'.$create_passwd.':'.$authchk)."\n";
    } else {
       print $client "refused\n";
    }
   #---------------------------  read and remove temporary files (for auto-enrollment).
       } elsif ($userinput =~/^autoretrieve:/) {
    if (isClient) {
       my ($cmd,$filename) = split(/:/,$userinput);
       my $source = $perlvar{'lonDaemons'}.'/tmp/'.$filename;
       if ( (-e $source) && ($filename ne '') ) {
    my $reply = '';
    if (open(my $fh,$source)) {
       while (<$fh>) {
    chomp($_);
    $_ =~ s/^\s+//g;
    $_ =~ s/\s+$//g;
    $reply .= $_;
       }
       close($fh);
       print $client &escape($reply)."\n";
   #                                unlink($source);
    } else {
       print $client "error\n";
    }
       } else {
    print $client "error\n";
       }
    } else {
       print $client "refused\n";
    }
   #---------------------  read and retrieve institutional code format (for support form).
       } elsif ($userinput =~/^autoinstcodeformat:/) {
    if (isClient) {
       my $reply;
       my($cmd,$cdom,$course) = split(/:/,$userinput);
       my @pairs = split/\&/,$course;
       my %instcodes = ();
       my %codes = ();
       my @codetitles = ();
       my %cat_titles = ();
       my %cat_order = ();
       foreach (@pairs) {
    my ($key,$value) = split/=/,$_;
    $instcodes{&unescape($key)} = &unescape($value);
       }
       my $formatreply = &localenroll::instcode_format($cdom,\%instcodes,\%codes,\@codetitles,\%cat_titles,\%cat_order);
       if ($formatreply eq 'ok') {
    my $codes_str = &hash2str(%codes);
    my $codetitles_str = &array2str(@codetitles);
    my $cat_titles_str = &hash2str(%cat_titles);
    my $cat_order_str = &hash2str(%cat_order);
    print $client $codes_str.':'.$codetitles_str.':'.$cat_titles_str.':'.$cat_order_str."\n";
       }
    } else {
       print $client "refused\n";
    }
   # ------------------------------------------------------------- unknown command
   
       } else {
    # unknown command
    print $client "unknown_cmd\n";
       }
   # -------------------------------------------------------------------- complete
       Debug("process_request - returning 1");
       return 1;
   }
   #
   #   Decipher encoded traffic
   #  Parameters:
   #     input      - Encoded data.
   #  Returns:
   #     Decoded data or undef if encryption key was not yet negotiated.
   #  Implicit input:
   #     cipher  - This global holds the negotiated encryption key.
   #
   sub decipher {
       my ($input)  = @_;
       my $output = '';
       
       
       if($cipher) {
    my($enc, $enclength, $encinput) = split(/:/, $input);
    for(my $encidx = 0; $encidx < length($encinput); $encidx += 16) {
       $output .= 
    $cipher->decrypt(pack("H16", substr($encinput, $encidx, 16)));
    }
    return substr($output, 0, $enclength);
       } else {
    return undef;
       }
   }
   
   #
   #   Register a command processor.  This function is invoked to register a sub
   #   to process a request.  Once registered, the ProcessRequest sub can automatically
   #   dispatch requests to an appropriate sub, and do the top level validity checking
   #   as well:
   #    - Is the keyword recognized.
   #    - Is the proper client type attempting the request.
   #    - Is the request encrypted if it has to be.
   #   Parameters:
   #    $request_name         - Name of the request being registered.
   #                           This is the command request that will match
   #                           against the hash keywords to lookup the information
   #                           associated with the dispatch information.
   #    $procedure           - Reference to a sub to call to process the request.
   #                           All subs get called as follows:
   #                             Procedure($cmd, $tail, $replyfd, $key)
   #                             $cmd    - the actual keyword that invoked us.
   #                             $tail   - the tail of the request that invoked us.
   #                             $replyfd- File descriptor connected to the client
   #    $must_encode          - True if the request must be encoded to be good.
   #    $client_ok            - True if it's ok for a client to request this.
   #    $manager_ok           - True if it's ok for a manager to request this.
   # Side effects:
   #      - On success, the Dispatcher hash has an entry added for the key $RequestName
   #      - On failure, the program will die as it's a bad internal bug to try to 
   #        register a duplicate command handler.
   #
   sub register_handler {
       my ($request_name,$procedure,$must_encode, $client_ok,$manager_ok)   = @_;
   
       #  Don't allow duplication#
      
       if (defined $Dispatcher{$request_name}) {
    die "Attempting to define a duplicate request handler for $request_name\n";
       }
       #   Build the client type mask:
       
       my $client_type_mask = 0;
       if($client_ok) {
    $client_type_mask  |= $CLIENT_OK;
       }
       if($manager_ok) {
    $client_type_mask  |= $MANAGER_OK;
       }
      
       #  Enter the hash:
         
       my @entry = ($procedure, $must_encode, $client_type_mask);
      
       $Dispatcher{$request_name} = \@entry;
      
      
   }
   
   
   #------------------------------------------------------------------
   
   
   
   
 #  #
 #  Convert an error return code from lcpasswd to a string value.  #  Convert an error return code from lcpasswd to a string value.
 #  #
Line 3425  sub catchexception { Line 3044  sub catchexception {
     $SIG{'QUIT'}='DEFAULT';      $SIG{'QUIT'}='DEFAULT';
     $SIG{__DIE__}='DEFAULT';      $SIG{__DIE__}='DEFAULT';
     &status("Catching exception");      &status("Catching exception");
     &logthis("<font color=red>CRITICAL: "      &logthis("<font color='red'>CRITICAL: "
      ."ABNORMAL EXIT. Child $$ for server $thisserver died through "       ."ABNORMAL EXIT. Child $$ for server $thisserver died through "
      ."a crash with this error msg->[$error]</font>");       ."a crash with this error msg->[$error]</font>");
     &logthis('Famous last words: '.$status.' - '.$lastlog);      &logthis('Famous last words: '.$status.' - '.$lastlog);
Line 3436  sub catchexception { Line 3055  sub catchexception {
   
 sub timeout {  sub timeout {
     &status("Handling Timeout");      &status("Handling Timeout");
     &logthis("<font color=ref>CRITICAL: TIME OUT ".$$."</font>");      &logthis("<font color='red'>CRITICAL: TIME OUT ".$$."</font>");
     &catchexception('Timeout');      &catchexception('Timeout');
 }  }
 # -------------------------------- Set signal handlers to record abnormal exits  # -------------------------------- Set signal handlers to record abnormal exits
Line 3488  $server = IO::Socket::INET->new(LocalPor Line 3107  $server = IO::Socket::INET->new(LocalPor
 # global variables  # global variables
   
 my %children               = ();       # keys are current child process IDs  my %children               = ();       # keys are current child process IDs
 my $children               = 0;        # current number of children  
   
 sub REAPER {                        # takes care of dead children  sub REAPER {                        # takes care of dead children
     $SIG{CHLD} = \&REAPER;      $SIG{CHLD} = \&REAPER;
     &status("Handling child death");      &status("Handling child death");
     my $pid = wait;      my $pid;
     if (defined($children{$pid})) {      do {
  &logthis("Child $pid died");   $pid = waitpid(-1,&WNOHANG());
  $children --;   if (defined($children{$pid})) {
  delete $children{$pid};      &logthis("Child $pid died");
     } else {      delete($children{$pid});
  &logthis("Unknown Child $pid died");   } elsif ($pid > 0) {
       &logthis("Unknown Child $pid died");
    }
       } while ( $pid > 0 );
       foreach my $child (keys(%children)) {
    $pid = waitpid($child,&WNOHANG());
    if ($pid > 0) {
       &logthis("Child $child - $pid looks like we missed it's death");
       delete($children{$pid});
    }
     }      }
     &status("Finished Handling child death");      &status("Finished Handling child death");
 }  }
Line 3511  sub HUNTSMAN {                      # si Line 3138  sub HUNTSMAN {                      # si
     &logthis("Free socket: ".shutdown($server,2)); # free up socket      &logthis("Free socket: ".shutdown($server,2)); # free up socket
     my $execdir=$perlvar{'lonDaemons'};      my $execdir=$perlvar{'lonDaemons'};
     unlink("$execdir/logs/lond.pid");      unlink("$execdir/logs/lond.pid");
     &logthis("<font color=red>CRITICAL: Shutting down</font>");      &logthis("<font color='red'>CRITICAL: Shutting down</font>");
     &status("Done killing children");      &status("Done killing children");
     exit;                           # clean up with dignity      exit;                           # clean up with dignity
 }  }
Line 3521  sub HUPSMAN {                      # sig Line 3148  sub HUPSMAN {                      # sig
     &status("Killing children for restart (HUP)");      &status("Killing children for restart (HUP)");
     kill 'INT' => keys %children;      kill 'INT' => keys %children;
     &logthis("Free socket: ".shutdown($server,2)); # free up socket      &logthis("Free socket: ".shutdown($server,2)); # free up socket
     &logthis("<font color=red>CRITICAL: Restarting</font>");      &logthis("<font color='red'>CRITICAL: Restarting</font>");
     my $execdir=$perlvar{'lonDaemons'};      my $execdir=$perlvar{'lonDaemons'};
     unlink("$execdir/logs/lond.pid");      unlink("$execdir/logs/lond.pid");
     &status("Restarting self (HUP)");      &status("Restarting self (HUP)");
Line 3531  sub HUPSMAN {                      # sig Line 3158  sub HUPSMAN {                      # sig
 #  #
 #    Kill off hashes that describe the host table prior to re-reading it.  #    Kill off hashes that describe the host table prior to re-reading it.
 #    Hashes affected are:  #    Hashes affected are:
 #       %hostid, %hostdom %hostip  #       %hostid, %hostdom %hostip %hostdns.
 #  #
 sub KillHostHashes {  sub KillHostHashes {
     foreach my $key (keys %hostid) {      foreach my $key (keys %hostid) {
Line 3543  sub KillHostHashes { Line 3170  sub KillHostHashes {
     foreach my $key (keys %hostip) {      foreach my $key (keys %hostip) {
  delete $hostip{$key};   delete $hostip{$key};
     }      }
       foreach my $key (keys %hostdns) {
    delete $hostdns{$key};
       }
 }  }
 #  #
 #   Read in the host table from file and distribute it into the various hashes:  #   Read in the host table from file and distribute it into the various hashes:
Line 3553  sub KillHostHashes { Line 3183  sub KillHostHashes {
 sub ReadHostTable {  sub ReadHostTable {
   
     open (CONFIG,"$perlvar{'lonTabDir'}/hosts.tab") || die "Can't read host file";      open (CONFIG,"$perlvar{'lonTabDir'}/hosts.tab") || die "Can't read host file";
           my $myloncapaname = $perlvar{'lonHostID'};
       Debug("My loncapa name is : $myloncapaname");
     while (my $configline=<CONFIG>) {      while (my $configline=<CONFIG>) {
  my ($id,$domain,$role,$name,$ip)=split(/:/,$configline);   if (!($configline =~ /^\s*\#/)) {
  chomp($ip); $ip=~s/\D+$//;      my ($id,$domain,$role,$name,$ip)=split(/:/,$configline);
  $hostid{$ip}=$id;      chomp($ip); $ip=~s/\D+$//;
  $hostdom{$id}=$domain;      $hostid{$ip}=$id;         # LonCAPA name of host by IP.
  $hostip{$id}=$ip;      $hostdom{$id}=$domain;    # LonCAPA domain name of host. 
  if ($id eq $perlvar{'lonHostID'}) { $thisserver=$name; }      $hostip{$id}=$ip;      # IP address of host.
       $hostdns{$name} = $id;    # LonCAPA name of host by DNS.
   
       if ($id eq $perlvar{'lonHostID'}) { 
    Debug("Found me in the host table: $name");
    $thisserver=$name; 
       }
    }
     }      }
     close(CONFIG);      close(CONFIG);
 }  }
Line 3622  sub checkchildren { Line 3260  sub checkchildren {
     &logthis('Going to check on the children');      &logthis('Going to check on the children');
     my $docdir=$perlvar{'lonDocRoot'};      my $docdir=$perlvar{'lonDocRoot'};
     foreach (sort keys %children) {      foreach (sort keys %children) {
  sleep 1;   #sleep 1;
         unless (kill 'USR1' => $_) {          unless (kill 'USR1' => $_) {
     &logthis ('Child '.$_.' is dead');      &logthis ('Child '.$_.' is dead');
             &logstatus($$.' is dead');              &logstatus($$.' is dead');
       delete($children{$_});
         }           } 
     }      }
     sleep 5;      sleep 5;
     $SIG{ALRM} = sub { die "timeout" };      $SIG{ALRM} = sub { Debug("timeout"); 
          die "timeout";  };
     $SIG{__DIE__} = 'DEFAULT';      $SIG{__DIE__} = 'DEFAULT';
     &status("Checking on the children (waiting for reports)");      &status("Checking on the children (waiting for reports)");
     foreach (sort keys %children) {      foreach (sort keys %children) {
Line 3643  sub checkchildren { Line 3283  sub checkchildren {
     #my $result=`echo 'Killed lond process $_.' | mailto $emailto -s '$subj' > /dev/null`;      #my $result=`echo 'Killed lond process $_.' | mailto $emailto -s '$subj' > /dev/null`;
     #$execdir=$perlvar{'lonDaemons'};      #$execdir=$perlvar{'lonDaemons'};
     #$result=`/bin/cp $execdir/logs/lond.log $execdir/logs/lond.log.$_`;      #$result=`/bin/cp $execdir/logs/lond.log $execdir/logs/lond.log.$_`;
       delete($children{$_});
     alarm(0);      alarm(0);
   }    }
         }          }
Line 3650  sub checkchildren { Line 3291  sub checkchildren {
     $SIG{ALRM} = 'DEFAULT';      $SIG{ALRM} = 'DEFAULT';
     $SIG{__DIE__} = \&catchexception;      $SIG{__DIE__} = \&catchexception;
     &status("Finished checking children");      &status("Finished checking children");
       &logthis('Finished Checking children');
 }  }
   
 # --------------------------------------------------------------------- Logging  # --------------------------------------------------------------------- Logging
Line 3680  sub Debug { Line 3322  sub Debug {
 #     reply   - Text to send to client.  #     reply   - Text to send to client.
 #     request - Original request from client.  #     request - Original request from client.
 #  #
 #  Note: This increments Transactions  
 #  
 sub Reply {  sub Reply {
     alarm(120);      my ($fd, $reply, $request) = @_;
     my $fd      = shift;  
     my $reply   = shift;  
     my $request = shift;  
   
     print $fd $reply;      print $fd $reply;
     Debug("Request was $request  Reply was $reply");      Debug("Request was $request  Reply was $reply");
   
     $Transactions++;      $Transactions++;
     alarm(0);  
   
   
 }  }
   
   
 #  #
 #    Sub to report a failure.  #    Sub to report a failure.
 #    This function:  #    This function:
Line 3712  sub Reply { Line 3349  sub Reply {
 #    client:  #    client:
 #  #
 sub Failure {  sub Failure {
    my $fd      = shift;      my $fd      = shift;
    my $reply   = shift;      my $reply   = shift;
    my $request = shift;      my $request = shift;
         
    $Failures++;      $Failures++;
    Reply($fd, $reply, $request);      # That's simple eh?      Reply($fd, $reply, $request);      # That's simple eh?
 }  }
 # ------------------------------------------------------------------ Log status  # ------------------------------------------------------------------ Log status
   
 sub logstatus {  sub logstatus {
    &status("Doing logging");      &status("Doing logging");
    my $docdir=$perlvar{'lonDocRoot'};      my $docdir=$perlvar{'lonDocRoot'};
    {      {
       my $fh=IO::File->new(">>$docdir/lon-status/londstatus.txt");   my $fh=IO::File->new(">$docdir/lon-status/londchld/$$.txt");
       print $fh $$."\t".$currenthostid."\t".$status."\t".$lastlog."\n";          print $fh $status."\n".$lastlog."\n".time."\n$keymode";
       $fh->close();          $fh->close();
    }      }
    &status("Finished londstatus.txt");      &status("Finished $$.txt");
    {      {
       my $fh=IO::File->new(">$docdir/lon-status/londchld/$$.txt");   open(LOG,">>$docdir/lon-status/londstatus.txt");
       print $fh $status."\n".$lastlog."\n".time;   flock(LOG,LOCK_EX);
       $fh->close();   print LOG $$."\t".$clientname."\t".$currenthostid."\t"
    }      .$status."\t".$lastlog."\t $keymode\n";
    ResetStatistics;   flock(DB,LOCK_UN);
    &status("Finished logging");   close(LOG);
          }
       &status("Finished logging");
 }  }
   
 sub initnewstatus {  sub initnewstatus {
Line 3759  sub status { Line 3397  sub status {
     my $what=shift;      my $what=shift;
     my $now=time;      my $now=time;
     my $local=localtime($now);      my $local=localtime($now);
     my $status = "lond: $what $local ";      $status=$local.': '.$what;
     if($Transactions) {      $0='lond: '.$what.' '.$local;
        $status .= " Transactions: $Transactions Failed; $Failures";  
     }  
     $0=$status;  
 }  }
   
 # -------------------------------------------------------- Escape Special Chars  # -------------------------------------------------------- Escape Special Chars
Line 3796  sub reconlonc { Line 3431  sub reconlonc {
             kill USR1 => $loncpid;              kill USR1 => $loncpid;
         } else {          } else {
     &logthis(      &logthis(
               "<font color=red>CRITICAL: "                "<font color='red'>CRITICAL: "
              ."lonc at pid $loncpid not responding, giving up</font>");               ."lonc at pid $loncpid not responding, giving up</font>");
         }          }
     } else {      } else {
       &logthis('<font color=red>CRITICAL: lonc not running, giving up</font>');        &logthis('<font color="red">CRITICAL: lonc not running, giving up</font>');
     }      }
 }  }
   
Line 3904  my $execdir=$perlvar{'lonDaemons'}; Line 3539  my $execdir=$perlvar{'lonDaemons'};
 open (PIDSAVE,">$execdir/logs/lond.pid");  open (PIDSAVE,">$execdir/logs/lond.pid");
 print PIDSAVE "$$\n";  print PIDSAVE "$$\n";
 close(PIDSAVE);  close(PIDSAVE);
 &logthis("<font color=red>CRITICAL: ---------- Starting ----------</font>");  &logthis("<font color='red'>CRITICAL: ---------- Starting ----------</font>");
 &status('Starting');  &status('Starting');
   
   
Line 3922  $SIG{USR2} = \&UpdateHosts; Line 3557  $SIG{USR2} = \&UpdateHosts;
   
 ReadHostTable;  ReadHostTable;
   
   
 # --------------------------------------------------------------  # --------------------------------------------------------------
 #   Accept connections.  When a connection comes in, it is validated  #   Accept connections.  When a connection comes in, it is validated
 #   and if good, a child process is created to process transactions  #   and if good, a child process is created to process transactions
Line 3938  while (1) { Line 3572  while (1) {
   
 sub make_new_child {  sub make_new_child {
     my $pid;      my $pid;
   #    my $cipher;     # Now global
     my $sigset;      my $sigset;
   
     $client = shift;      $client = shift;
Line 3959  sub make_new_child { Line 3594  sub make_new_child {
     #  the pid hash.      #  the pid hash.
     #      #
     my $caller = getpeername($client);      my $caller = getpeername($client);
     my ($port,$iaddr)=unpack_sockaddr_in($caller);      my ($port,$iaddr);
     $clientip=inet_ntoa($iaddr);      if (defined($caller) && length($caller) > 0) {
    ($port,$iaddr)=unpack_sockaddr_in($caller);
       } else {
    &logthis("Unable to determine who caller was, getpeername returned nothing");
       }
       if (defined($iaddr)) {
    $clientip  = inet_ntoa($iaddr);
    Debug("Connected with $clientip");
    $clientdns = gethostbyaddr($iaddr, AF_INET);
    Debug("Connected with $clientdns by name");
       } else {
    &logthis("Unable to determine clientip");
    $clientip='Unavailable';
       }
           
     if ($pid) {      if ($pid) {
         # Parent records the child's birth and returns.          # Parent records the child's birth and returns.
         sigprocmask(SIG_UNBLOCK, $sigset)          sigprocmask(SIG_UNBLOCK, $sigset)
             or die "Can't unblock SIGINT for fork: $!\n";              or die "Can't unblock SIGINT for fork: $!\n";
         $children{$pid} = $clientip;          $children{$pid} = $clientip;
         $children++;  
         &status('Started child '.$pid);          &status('Started child '.$pid);
         return;          return;
     } else {      } else {
Line 3984  sub make_new_child { Line 3631  sub make_new_child {
         sigprocmask(SIG_UNBLOCK, $sigset)          sigprocmask(SIG_UNBLOCK, $sigset)
             or die "Can't unblock SIGINT for fork: $!\n";              or die "Can't unblock SIGINT for fork: $!\n";
   
   #        my $tmpsnum=0;            # Now global
   #---------------------------------------------------- kerberos 5 initialization
         &Authen::Krb5::init_context();          &Authen::Krb5::init_context();
         &Authen::Krb5::init_ets();          &Authen::Krb5::init_ets();
   
Line 3993  sub make_new_child { Line 3640  sub make_new_child {
 # =============================================================================  # =============================================================================
             # do something with the connection              # do something with the connection
 # -----------------------------------------------------------------------------  # -----------------------------------------------------------------------------
  # see if we know client and check for spoof IP by challenge   # see if we know client and 'check' for spoof IP by ineffective challenge
   
  ReadManagerTable; # May also be a manager!!   ReadManagerTable; # May also be a manager!!
   
Line 4011  sub make_new_child { Line 3658  sub make_new_child {
     $clientname = $managers{$clientip};      $clientname = $managers{$clientip};
  }   }
  my $clientok;   my $clientok;
   
  if ($clientrec || $ismanager) {   if ($clientrec || $ismanager) {
     &status("Waiting for init from $clientip $clientname");      &status("Waiting for init from $clientip $clientname");
     &logthis('<font color="yellow">INFO: Connection, '.      &logthis('<font color="yellow">INFO: Connection, '.
Line 4018  sub make_new_child { Line 3666  sub make_new_child {
   " ($clientname) connection type = $ConnectionType </font>" );    " ($clientname) connection type = $ConnectionType </font>" );
     &status("Connecting $clientip  ($clientname))");       &status("Connecting $clientip  ($clientname))"); 
     my $remotereq=<$client>;      my $remotereq=<$client>;
     $remotereq=~s/[^\w:]//g;      chomp($remotereq);
       Debug("Got init: $remotereq");
       my $inikeyword = split(/:/, $remotereq);
     if ($remotereq =~ /^init/) {      if ($remotereq =~ /^init/) {
  &sethost("sethost:$perlvar{'lonHostID'}");   &sethost("sethost:$perlvar{'lonHostID'}");
  my $challenge="$$".time;   #
  print $client "$challenge\n";   #  If the remote is attempting a local init... give that a try:
  &status(   #
  "Waiting for challenge reply from $clientip ($clientname)");    my ($i, $inittype) = split(/:/, $remotereq);
  $remotereq=<$client>;  
  $remotereq=~s/\W//g;   # If the connection type is ssl, but I didn't get my
  if ($challenge eq $remotereq) {   # certificate files yet, then I'll drop  back to 
     $clientok=1;   # insecure (if allowed).
     print $client "ok\n";  
    if($inittype eq "ssl") {
       my ($ca, $cert) = lonssl::CertificateFile;
       my $kfile       = lonssl::KeyFile;
       if((!$ca)   || 
          (!$cert) || 
          (!$kfile)) {
    $inittype = ""; # This forces insecure attempt.
    &logthis("<font color=\"blue\"> Certificates not "
    ."installed -- trying insecure auth</font>");
       } else { # SSL certificates are in place so
       } # Leave the inittype alone.
    }
   
    if($inittype eq "local") {
       my $key = LocalConnection($client, $remotereq);
       if($key) {
    Debug("Got local key $key");
    $clientok     = 1;
    my $cipherkey = pack("H32", $key);
    $cipher       = new IDEA($cipherkey);
    print $client "ok:local\n";
    &logthis('<font color="green"'
    . "Successful local authentication </font>");
    $keymode = "local"
       } else {
    Debug("Failed to get local key");
    $clientok = 0;
    shutdown($client, 3);
    close $client;
       }
    } elsif ($inittype eq "ssl") {
       my $key = SSLConnection($client);
       if ($key) {
    $clientok = 1;
    my $cipherkey = pack("H32", $key);
    $cipher       = new IDEA($cipherkey);
    &logthis('<font color="green">'
    ."Successfull ssl authentication with $clientname </font>");
    $keymode = "ssl";
        
       } else {
    $clientok = 0;
    close $client;
       }
      
  } else {   } else {
     &logthis(      my $ok = InsecureConnection($client);
      "<font color=blue>WARNING: $clientip did not reply challenge</font>");      if($ok) {
     &status('No challenge reply '.$clientip);   $clientok = 1;
    &logthis('<font color="green">'
    ."Successful insecure authentication with $clientname </font>");
    print $client "ok\n";
    $keymode = "insecure";
       } else {
    &logthis('<font color="yellow">'
     ."Attempted insecure connection disallowed </font>");
    close $client;
    $clientok = 0;
   
       }
  }   }
     } else {      } else {
  &logthis(   &logthis(
  "<font color=blue>WARNING: "   "<font color='blue'>WARNING: "
  ."$clientip failed to initialize: >$remotereq< </font>");   ."$clientip failed to initialize: >$remotereq< </font>");
  &status('No init '.$clientip);   &status('No init '.$clientip);
     }      }
       
  } else {   } else {
     &logthis(      &logthis(
      "<font color=blue>WARNING: Unknown client $clientip</font>");       "<font color='blue'>WARNING: Unknown client $clientip</font>");
     &status('Hung up on '.$clientip);      &status('Hung up on '.$clientip);
  }   }
    
  if ($clientok) {   if ($clientok) {
 # ---------------- New known client connecting, could mean machine online again  # ---------------- New known client connecting, could mean machine online again
           
Line 4057  sub make_new_child { Line 3765  sub make_new_child {
  }   }
  &reconlonc("$perlvar{'lonSockDir'}/$id");   &reconlonc("$perlvar{'lonSockDir'}/$id");
     }      }
     &logthis("<font color=green>Established connection: $clientname</font>");      &logthis("<font color='green'>Established connection: $clientname</font>");
     &status('Will listen to '.$clientname);      &status('Will listen to '.$clientname);
   
     ResetStatistics();  
   
 # ------------------------------------------------------------ Process requests  # ------------------------------------------------------------ Process requests
     my $KeepGoing = 1;      my $keep_going = 1;
     while ((my $userinput=GetRequest) && $KeepGoing) {      my $user_input;
  $KeepGoing = ProcessRequest($userinput);      while(($user_input = get_request) && $keep_going) {
 # -------------------------------------------------------------------- complete   alarm(120);
    Debug("Main: Got $user_input\n");
  &status('Listening to '.$clientname);   $keep_going = &process_request($user_input);
    alarm(0);
    &status('Listening to '.$clientname." ($keymode)");   
     }      }
   
 # --------------------------------------------- client unknown or fishy, refuse  # --------------------------------------------- client unknown or fishy, refuse
  } else {   }  else {
     print $client "refused\n";      print $client "refused\n";
     $client->close();      $client->close();
     &logthis("<font color=blue>WARNING: "      &logthis("<font color='blue'>WARNING: "
      ."Rejected client $clientip, closing connection</font>");       ."Rejected client $clientip, closing connection</font>");
  }   }
     }                   }            
           
 # =============================================================================  # =============================================================================
           
     &logthis("<font color=red>CRITICAL: "      &logthis("<font color='red'>CRITICAL: "
      ."Disconnect from $clientip ($clientname)</font>");           ."Disconnect from $clientip ($clientname)</font>");    
           
           
Line 4106  sub make_new_child { Line 3814  sub make_new_child {
 #  #
 sub ManagePermissions  sub ManagePermissions
 {  {
     my $request = shift;  
     my $domain  = shift;      my ($request, $domain, $user, $authtype) = @_;
     my $user    = shift;  
     my $authtype= shift;  
   
     # See if the request is of the form /$domain/_au      # See if the request is of the form /$domain/_au
     &logthis("ruequest is $request");  
     if($request =~ /^(\/$domain\/_au)$/) { # It's an author rolesput...      if($request =~ /^(\/$domain\/_au)$/) { # It's an author rolesput...
  my $execdir = $perlvar{'lonDaemons'};   my $execdir = $perlvar{'lonDaemons'};
  my $userhome= "/home/$user" ;   my $userhome= "/home/$user" ;
Line 4120  sub ManagePermissions Line 3825  sub ManagePermissions
  system("$execdir/lchtmldir $userhome $user $authtype");   system("$execdir/lchtmldir $userhome $user $authtype");
     }      }
 }  }
   
   
   #
   #  Return the full path of a user password file, whether it exists or not.
   # Parameters:
   #   domain     - Domain in which the password file lives.
   #   user       - name of the user.
   # Returns:
   #    Full passwd path:
   #
   sub password_path {
       my ($domain, $user) = @_;
   
   
       my $path   = &propath($domain, $user);
       $path  .= "/passwd";
   
       return $path;
   }
   
   #   Password Filename
   #   Returns the path to a passwd file given domain and user... only if
   #  it exists.
   # Parameters:
   #   domain    - Domain in which to search.
   #   user      - username.
   # Returns:
   #   - If the password file exists returns its path.
   #   - If the password file does not exist, returns undefined.
   #
   sub password_filename {
       my ($domain, $user) = @_;
   
       Debug ("PasswordFilename called: dom = $domain user = $user");
   
       my $path  = &password_path($domain, $user);
       Debug("PasswordFilename got path: $path");
       if(-e $path) {
    return $path;
       } else {
    return undef;
       }
   }
   
   #
   #   Rewrite the contents of the user's passwd file.
   #  Parameters:
   #    domain    - domain of the user.
   #    name      - User's name.
   #    contents  - New contents of the file.
   # Returns:
   #   0    - Failed.
   #   1    - Success.
   #
   sub rewrite_password_file {
       my ($domain, $user, $contents) = @_;
   
       my $file = &password_filename($domain, $user);
       if (defined $file) {
    my $pf = IO::File->new(">$file");
    if($pf) {
       print $pf "$contents\n";
       return 1;
    } else {
       return 0;
    }
       } else {
    return 0;
       }
   
   }
   
 #  #
 #   GetAuthType - Determines the authorization type of a user in a domain.  #   get_auth_type - Determines the authorization type of a user in a domain.
   
 #     Returns the authorization type or nouser if there is no such user.  #     Returns the authorization type or nouser if there is no such user.
 #  #
 sub GetAuthType   sub get_auth_type 
 {  {
     my $domain = shift;  
     my $user   = shift;  
   
     Debug("GetAuthType( $domain, $user ) \n");      my ($domain, $user)  = @_;
   
       Debug("get_auth_type( $domain, $user ) \n");
     my $proname    = &propath($domain, $user);       my $proname    = &propath($domain, $user); 
     my $passwdfile = "$proname/passwd";      my $passwdfile = "$proname/passwd";
     if( -e $passwdfile ) {      if( -e $passwdfile ) {
Line 4146  sub GetAuthType Line 3923  sub GetAuthType
  }   }
   
  return "$authtype:$availinfo";   return "$authtype:$availinfo";
     }      } else {
     else {  
  Debug("Returning nouser");   Debug("Returning nouser");
  return "nouser";   return "nouser";
     }      }
 }  }
   
   #
   #  Validate a user given their domain, name and password.  This utility
   #  function is used by both  AuthenticateHandler and ChangePasswordHandler
   #  to validate the login credentials of a user.
   # Parameters:
   #    $domain    - The domain being logged into (this is required due to
   #                 the capability for multihomed systems.
   #    $user      - The name of the user being validated.
   #    $password  - The user's propoposed password.
   #
   # Returns:
   #     1        - The domain,user,pasword triplet corresponds to a valid
   #                user.
   #     0        - The domain,user,password triplet is not a valid user.
   #
   sub validate_user {
       my ($domain, $user, $password) = @_;
   
   
       # Why negative ~pi you may well ask?  Well this function is about
       # authentication, and therefore very important to get right.
       # I've initialized the flag that determines whether or not I've 
       # validated correctly to a value it's not supposed to get.
       # At the end of this function. I'll ensure that it's not still that
       # value so we don't just wind up returning some accidental value
       # as a result of executing an unforseen code path that
       # did not set $validated.
   
       my $validated = -3.14159;
   
       #  How we authenticate is determined by the type of authentication
       #  the user has been assigned.  If the authentication type is
       #  "nouser", the user does not exist so we will return 0.
   
       my $contents = &get_auth_type($domain, $user);
       my ($howpwd, $contentpwd) = split(/:/, $contents);
   
       my $null = pack("C",0); # Used by kerberos auth types.
   
       if ($howpwd ne 'nouser') {
   
    if($howpwd eq "internal") { # Encrypted is in local password file.
       $validated = (crypt($password, $contentpwd) eq $contentpwd);
    }
    elsif ($howpwd eq "unix") { # User is a normal unix user.
       $contentpwd = (getpwnam($user))[1];
       if($contentpwd) {
    if($contentpwd eq 'x') { # Shadow password file...
       my $pwauth_path = "/usr/local/sbin/pwauth";
       open PWAUTH,  "|$pwauth_path" or
    die "Cannot invoke authentication";
       print PWAUTH "$user\n$password\n";
       close PWAUTH;
       $validated = ! $?;
   
    } else {         # Passwords in /etc/passwd. 
       $validated = (crypt($password,
    $contentpwd) eq $contentpwd);
    }
       } else {
    $validated = 0;
       }
    }
    elsif ($howpwd eq "krb4") { # user is in kerberos 4 auth. domain.
       if(! ($password =~ /$null/) ) {
    my $k4error = &Authen::Krb4::get_pw_in_tkt($user,
      "",
      $contentpwd,,
      'krbtgt',
      $contentpwd,
      1,
      $password);
    if(!$k4error) {
       $validated = 1;
    } else {
       $validated = 0;
       &logthis('krb4: '.$user.', '.$contentpwd.', '.
        &Authen::Krb4::get_err_txt($Authen::Krb4::error));
    }
       } else {
    $validated = 0; # Password has a match with null.
       }
    } elsif ($howpwd eq "krb5") { # User is in kerberos 5 auth. domain.
       if(!($password =~ /$null/)) { # Null password not allowed.
    my $krbclient = &Authen::Krb5::parse_name($user.'@'
     .$contentpwd);
    my $krbservice = "krbtgt/".$contentpwd."\@".$contentpwd;
    my $krbserver  = &Authen::Krb5::parse_name($krbservice);
    my $credentials= &Authen::Krb5::cc_default();
    $credentials->initialize($krbclient);
    my $krbreturn  = &Authen::KRb5::get_in_tkt_with_password($krbclient,
    $krbserver,
    $password,
    $credentials);
    $validated = ($krbreturn == 1);
       } else {
    $validated = 0;
       }
    } elsif ($howpwd eq "localauth") { 
       #  Authenticate via installation specific authentcation method:
       $validated = &localauth::localauth($user, 
          $password, 
          $contentpwd);
    } else { # Unrecognized auth is also bad.
       $validated = 0;
    }
       } else {
    $validated = 0;
       }
       #
       #  $validated has the correct stat of the authentication:
       #
   
       unless ($validated != -3.14159) {
    die "ValidateUser - failed to set the value of validated";
       }
       return $validated;
   }
   
   
 sub addline {  sub addline {
     my ($fname,$hostid,$ip,$newline)=@_;      my ($fname,$hostid,$ip,$newline)=@_;
     my $contents;      my $contents;
Line 4237  sub chatadd { Line 4133  sub chatadd {
 sub unsub {  sub unsub {
     my ($fname,$clientip)=@_;      my ($fname,$clientip)=@_;
     my $result;      my $result;
       my $unsubs = 0; # Number of successful unsubscribes:
   
   
       # An old way subscriptions were handled was to have a 
       # subscription marker file:
   
       Debug("Attempting unlink of $fname.$clientname");
     if (unlink("$fname.$clientname")) {      if (unlink("$fname.$clientname")) {
  $result="ok\n";   $unsubs++; # Successful unsub via marker file.
     } else {      } 
  $result="not_subscribed\n";  
     }      # The more modern way to do it is to have a subscription list
       # file:
   
     if (-e "$fname.subscription") {      if (-e "$fname.subscription") {
  my $found=&addline($fname,$clientname,$clientip,'');   my $found=&addline($fname,$clientname,$clientip,'');
  if ($found) { $result="ok\n"; }   if ($found) { 
       $unsubs++;
    }
       } 
   
       #  If either or both of these mechanisms succeeded in unsubscribing a 
       #  resource we can return ok:
   
       if($unsubs) {
    $result = "ok\n";
     } else {      } else {
  if ($result != "ok\n") { $result="not_subscribed\n"; }   $result = "not_subscribed\n";
     }      }
   
     return $result;      return $result;
 }  }
   
Line 4369  sub make_passwd_file { Line 4284  sub make_passwd_file {
  }   }
     } elsif ($umode eq 'unix') {      } elsif ($umode eq 'unix') {
  {   {
     my $execpath="$perlvar{'lonDaemons'}/"."lcuseradd";      #
       #  Don't allow the creation of privileged accounts!!! that would
       #  be real bad!!!
       #
       my $uid = getpwnam($uname);
       if((defined $uid) && ($uid == 0)) {
    &logthis(">>>Attempted to create privilged account blocked");
    return "no_priv_account_error\n";
       }
   
       my $execpath       ="$perlvar{'lonDaemons'}/"."lcuseradd";
   
       my $lc_error_file  = $execdir."/tmp/lcuseradd".$$.".status";
     {      {
  &Debug("Executing external: ".$execpath);   &Debug("Executing external: ".$execpath);
  &Debug("user  = ".$uname.", Password =". $npass);   &Debug("user  = ".$uname.", Password =". $npass);
Line 4377  sub make_passwd_file { Line 4304  sub make_passwd_file {
  print $se "$uname\n";   print $se "$uname\n";
  print $se "$npass\n";   print $se "$npass\n";
  print $se "$npass\n";   print $se "$npass\n";
    print $se "$lc_error_file\n"; # Status -> unique file.
     }      }
     my $useraddok = $?;      my $error = IO::File->new("< $lc_error_file");
       my $useraddok = <$error>;
       $error->close;
       unlink($lc_error_file);
   
       chomp $useraddok;
   
     if($useraddok > 0) {      if($useraddok > 0) {
  &logthis("Failed lcuseradd: ".&lcuseraddstrerror($useraddok));   my $error_text = &lcuseraddstrerror($useraddok);
    &logthis("Failed lcuseradd: $error_text");
    $result = "lcuseradd_failed:$error_text\n";
       }  else {
    my $pf = IO::File->new(">$passfilename");
    print $pf "unix:\n";
     }      }
     my $pf = IO::File->new(">$passfilename");  
     print $pf "unix:\n";  
  }   }
     } elsif ($umode eq 'none') {      } elsif ($umode eq 'none') {
  {   {
     my $pf = IO::File->new(">$passfilename");      my $pf = IO::File->new("> $passfilename");
     print $pf "none:\n";      print $pf "none:\n";
  }   }
     } else {      } else {
Line 4401  sub sethost { Line 4338  sub sethost {
     my (undef,$hostid)=split(/:/,$remotereq);      my (undef,$hostid)=split(/:/,$remotereq);
     if (!defined($hostid)) { $hostid=$perlvar{'lonHostID'}; }      if (!defined($hostid)) { $hostid=$perlvar{'lonHostID'}; }
     if ($hostip{$perlvar{'lonHostID'}} eq $hostip{$hostid}) {      if ($hostip{$perlvar{'lonHostID'}} eq $hostip{$hostid}) {
  $currenthostid=$hostid;   $currenthostid  =$hostid;
  $currentdomainid=$hostdom{$hostid};   $currentdomainid=$hostdom{$hostid};
  &logthis("Setting hostid to $hostid, and domain to $currentdomainid");   &logthis("Setting hostid to $hostid, and domain to $currentdomainid");
     } else {      } else {
Line 4417  sub version { Line 4354  sub version {
     $remoteVERSION=(split(/:/,$userinput))[1];      $remoteVERSION=(split(/:/,$userinput))[1];
     return "version:$VERSION";      return "version:$VERSION";
 }  }
 ############## >>>>>>>>>>>>>>>>>>>>>>>>>> FUTUREWORK <<<<<<<<<<<<<<<<<<<<<<<<<<<<  
 #There is a copy of this in lonnet.pm  #There is a copy of this in lonnet.pm
 #   Can we hoist these lil' things out into common places?  
 #  
 sub userload {  sub userload {
     my $numusers=0;      my $numusers=0;
     {      {
Line 4443  sub userload { Line 4378  sub userload {
     return $userloadpercent;      return $userloadpercent;
 }  }
   
   # Routines for serializing arrays and hashes (copies from lonnet)
   
   sub array2str {
     my (@array) = @_;
     my $result=&arrayref2str(\@array);
     $result=~s/^__ARRAY_REF__//;
     $result=~s/__END_ARRAY_REF__$//;
     return $result;
   }
                                                                                    
   sub arrayref2str {
     my ($arrayref) = @_;
     my $result='__ARRAY_REF__';
     foreach my $elem (@$arrayref) {
       if(ref($elem) eq 'ARRAY') {
         $result.=&arrayref2str($elem).'&';
       } elsif(ref($elem) eq 'HASH') {
         $result.=&hashref2str($elem).'&';
       } elsif(ref($elem)) {
         #print("Got a ref of ".(ref($elem))." skipping.");
       } else {
         $result.=&escape($elem).'&';
       }
     }
     $result=~s/\&$//;
     $result .= '__END_ARRAY_REF__';
     return $result;
   }
                                                                                    
   sub hash2str {
     my (%hash) = @_;
     my $result=&hashref2str(\%hash);
     $result=~s/^__HASH_REF__//;
     $result=~s/__END_HASH_REF__$//;
     return $result;
   }
                                                                                    
   sub hashref2str {
     my ($hashref)=@_;
     my $result='__HASH_REF__';
     foreach (sort(keys(%$hashref))) {
       if (ref($_) eq 'ARRAY') {
         $result.=&arrayref2str($_).'=';
       } elsif (ref($_) eq 'HASH') {
         $result.=&hashref2str($_).'=';
       } elsif (ref($_)) {
         $result.='=';
         #print("Got a ref of ".(ref($_))." skipping.");
       } else {
           if ($_) {$result.=&escape($_).'=';} else { last; }
       }
   
       if(ref($hashref->{$_}) eq 'ARRAY') {
         $result.=&arrayref2str($hashref->{$_}).'&';
       } elsif(ref($hashref->{$_}) eq 'HASH') {
         $result.=&hashref2str($hashref->{$_}).'&';
       } elsif(ref($hashref->{$_})) {
          $result.='&';
         #print("Got a ref of ".(ref($hashref->{$_}))." skipping.");
       } else {
         $result.=&escape($hashref->{$_}).'&';
       }
     }
     $result=~s/\&$//;
     $result .= '__END_HASH_REF__';
     return $result;
   }
   
 # ----------------------------------- POD (plain old documentation, CPAN style)  # ----------------------------------- POD (plain old documentation, CPAN style)
   
 =head1 NAME  =head1 NAME

Removed from v.1.178.2.3  
changed lines
  Added in v.1.224


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