--- loncom/lond 2003/09/09 20:47:46 1.142 +++ loncom/lond 2003/09/23 11:23:31 1.147 @@ -2,7 +2,7 @@ # The LearningOnline Network # lond "LON Daemon" Server (port "LOND" 5663) # -# $Id: lond,v 1.142 2003/09/09 20:47:46 www Exp $ +# $Id: lond,v 1.147 2003/09/23 11:23:31 foxr Exp $ # # Copyright Michigan State University Board of Trustees # @@ -60,6 +60,28 @@ # 09/08/2003 Ron Fox: Told lond to take care of change logging so we # don't have to remember it: # $Log: lond,v $ +# Revision 1.147 2003/09/23 11:23:31 foxr +# Comlplete implementation of reinit functionality. Must still implement +# the actual initialization functionality, but the process can now +# receive the request and either invoke the appropriate internal function or +# signal the correct lonc. +# +# Revision 1.146 2003/09/16 10:28:14 foxr +# ReinitProcess - decode the process selector and produce the associated pid +# filename. Note: While it is possible to test that valid process selectors are +# handled properly I am not able to test that invalid process selectors produce +# the appropriate error as lonManage also blocks the use of invalid process selectors. +# +# Revision 1.145 2003/09/16 10:13:20 foxr +# Added ReinitProcess function to oversee the parsing and processing of the +# reinit: client request. +# +# Revision 1.144 2003/09/16 09:47:01 foxr +# Added skeletal support for SIGUSR2 (update hosts.tab) +# +# Revision 1.143 2003/09/15 10:03:52 foxr +# Completed and tested code for pushfile. +# # Revision 1.142 2003/09/09 20:47:46 www # Permanently store chatroom entries in chatroom.log # @@ -87,13 +109,14 @@ use Authen::Krb4; use Authen::Krb5; use lib '/home/httpd/lib/perl/'; use localauth; +use File::Copy; my $DEBUG = 0; # Non zero to enable debug log entries. my $status=''; my $lastlog=''; -my $VERSION='$Revision: 1.142 $'; #' stupid emacs +my $VERSION='$Revision: 1.147 $'; #' stupid emacs my $remoteVERSION; my $currenthostid; my $currentdomainid; @@ -186,6 +209,97 @@ sub ValidManager { } } # +# CopyFile: Called as part of the process of installing a +# new configuration file. This function copies an existing +# file to a backup file. +# Parameters: +# oldfile - Name of the file to backup. +# newfile - Name of the backup file. +# Return: +# 0 - Failure (errno has failure reason). +# 1 - Success. +# +sub CopyFile { + my $oldfile = shift; + my $newfile = shift; + + # The file must exist: + + if(-e $oldfile) { + + # Read the old file. + + my $oldfh = IO::File->new("< $oldfile"); + if(!$oldfh) { + return 0; + } + my @contents = <$oldfh>; # Suck in the entire file. + + # write the backup file: + + my $newfh = IO::File->new("> $newfile"); + if(!(defined $newfh)){ + return 0; + } + my $lines = scalar @contents; + for (my $i =0; $i < $lines; $i++) { + print $newfh ($contents[$i]); + } + + $oldfh->close; + $newfh->close; + + chmod(0660, $newfile); + + return 1; + + } else { + return 0; + } +} + +# +# InstallFile: Called to install an administrative file: +# - The file is created with .tmp +# - The .tmp file is then mv'd to +# This lugubrious procedure is done to ensure that we are never without +# a valid, even if dated, version of the file regardless of who crashes +# and when the crash occurs. +# +# Parameters: +# Name of the file +# File Contents. +# Return: +# nonzero - success. +# 0 - failure and $! has an errno. +# +sub InstallFile { + my $Filename = shift; + my $Contents = shift; + my $TempFile = $Filename.".tmp"; + + # Open the file for write: + + my $fh = IO::File->new("> $TempFile"); # Write to temp. + if(!(defined $fh)) { + &logthis(' Unable to create '.$TempFile.""); + return 0; + } + # write the contents of the file: + + print $fh ($Contents); + $fh->close; # In case we ever have a filesystem w. locking + + chmod(0660, $TempFile); + + # Now we can move install the file in position. + + move($TempFile, $Filename); + + return 1; +} + +# # PushFile: Called to do an administrative push of a file. # - Ensure the file being pushed is one we support. # - Backup the old file to @@ -229,19 +343,79 @@ sub PushFile { # my $backupfile = $tablefile; $backupfile =~ s/\.tab$/.old/; - # CopyFile($tablefile, $backupfile); + if(!CopyFile($tablefile, $backupfile)) { + &logthis(' CopyFile from '.$tablefile." to ".$backupfile." failed "); + return "error:$!"; + } &logthis(' Pushfile: backed up ' .$tablefile." to $backupfile"); # Install the new file: - # InstallFile($tablefile, $contents); + if(!InstallFile($tablefile, $contents)) { + &logthis(' Pushfile: unable to install ' + .$tablefile." $! "); + return "error:$!"; + } + else { + &logthis(' Installed new '.$tablefile + .""); + + } + # Indicate success: return "ok"; } + +# +# Called to re-init either lonc or lond. +# +# Parameters: +# request - The full request by the client. This is of the form +# reinit: +# where is allowed to be either of +# lonc or lond +# +# Returns: +# The string to be sent back to the client either: +# ok - Everything worked just fine. +# error:why - There was a failure and why describes the reason. +# +# +sub ReinitProcess { + my $request = shift; + + + # separate the request (reinit) from the process identifier and + # validate it producing the name of the .pid file for the process. + # + # + my ($junk, $process) = split(":", $request); + my $processpidfile = $perlvar{'lonDaemons'}.'/logs/'; + if($process eq 'lonc') { + $processpidfile = $processpidfile."lonc.pid"; + if (!open(PIDFILE, "< $processpidfile")) { + return "error:Open failed for $processpidfile"; + } + my $loncpid = ; + close(PIDFILE); + logthis(' Reinitializing lonc pid='.$loncpid + .""); + kill("USR2", $loncpid); + } elsif ($process eq 'lond') { + logthis(' Reinitializing self (lond) '); + &UpdateHosts; # Lond is us!! + } else { + &logthis('"); + return "error:Invalid process identifier $process"; + } + return 'ok'; +} + # # Convert an error return code from lcpasswd to a string value. # @@ -377,6 +551,20 @@ sub HUPSMAN { # sig exec("$execdir/lond"); # here we go again } +# +# Called in response to a USR2 signal. +# - Reread hosts.tab +# - All children connected to hosts that were removed from hosts.tab +# are killed via SIGINT +# - All children connected to previously existing hosts are sent SIGUSR1 +# - Our internal hosts hash is updated to reflect the new contents of +# hosts.tab causing connections from hosts added to hosts.tab to +# now be honored. +# +sub UpdateHosts { + logthis(' Updating connections '); +} + sub checkchildren { &initnewstatus(); &logstatus(); @@ -619,7 +807,7 @@ $SIG{CHLD} = \&REAPER; $SIG{INT} = $SIG{TERM} = \&HUNTSMAN; $SIG{HUP} = \&HUPSMAN; $SIG{USR1} = \&checkchildren; - +$SIG{USR2} = \&UpdateHosts; # -------------------------------------------------------------- @@ -828,7 +1016,9 @@ sub make_new_child { if ($wasenc == 1) { my $cert = GetCertificate($userinput); if(ValidManager($cert)) { - print $client "ok\n"; + chomp($userinput); + my $reply = ReinitProcess($userinput); + print $client "$reply\n"; } else { print $client "refused\n"; } @@ -2393,6 +2583,17 @@ each connection is logged. =item * +SIGUSR2 + +Parent Signal assignment: + $SIG{USR2} = \&UpdateHosts + +Child signal assignment: + NONE + + +=item * + SIGCHLD Parent signal assignment: