Annotation of loncom/loncnew, revision 1.88
1.1 foxr 1: #!/usr/bin/perl
1.2 albertel 2: # The LearningOnline Network with CAPA
3: # lonc maintains the connections to remote computers
4: #
1.88 ! foxr 5: # $Id: loncnew,v 1.87 2007/06/18 22:49:52 albertel Exp $
1.2 albertel 6: #
7: # Copyright Michigan State University Board of Trustees
8: #
9: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
1.17 foxr 10: ## LON-CAPA is free software; you can redistribute it and/or modify
1.2 albertel 11: # it under the terms of the GNU General Public License as published by
12: # the Free Software Foundation; either version 2 of the License, or
13: # (at your option) any later version.
14: #
15: # LON-CAPA is distributed in the hope that it will be useful,
16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18: # GNU General Public License for more details.
19: #
20: # You should have received a copy of the GNU General Public License
21: # along with LON-CAPA; if not, write to the Free Software
22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23: #
24: # /home/httpd/html/adm/gpl.txt
25: #
26: # http://www.lon-capa.org/
27: #
1.1 foxr 28: #
1.15 foxr 29: # new lonc handles n request out bver m connections to londs.
1.1 foxr 30: # This module is based on the Event class.
31: # Development iterations:
32: # - Setup basic event loop. (done)
33: # - Add timer dispatch. (done)
34: # - Add ability to accept lonc UNIX domain sockets. (done)
35: # - Add ability to create/negotiate lond connections (done).
1.7 foxr 36: # - Add general logic for dispatching requests and timeouts. (done).
37: # - Add support for the lonc/lond requests. (done).
1.38 foxr 38: # - Add logging/status monitoring. (done)
39: # - Add Signal handling - HUP restarts. USR1 status report. (done)
1.7 foxr 40: # - Add Configuration file I/O (done).
1.38 foxr 41: # - Add management/status request interface. (done)
1.8 foxr 42: # - Add deferred request capability. (done)
1.38 foxr 43: # - Detect transmission timeouts. (done)
1.7 foxr 44: #
45:
1.23 foxr 46: use strict;
1.1 foxr 47: use lib "/home/httpd/lib/perl/";
48: use Event qw(:DEFAULT );
49: use POSIX qw(:signal_h);
1.12 foxr 50: use POSIX;
1.1 foxr 51: use IO::Socket;
52: use IO::Socket::INET;
53: use IO::Socket::UNIX;
1.9 foxr 54: use IO::File;
1.6 foxr 55: use IO::Handle;
1.1 foxr 56: use Socket;
57: use Crypt::IDEA;
58: use LONCAPA::Queue;
59: use LONCAPA::Stack;
60: use LONCAPA::LondConnection;
1.7 foxr 61: use LONCAPA::LondTransaction;
1.1 foxr 62: use LONCAPA::Configuration;
1.67 albertel 63: use Fcntl qw(:flock);
1.1 foxr 64:
65:
66: # Read the httpd configuration file to get perl variables
67: # normally set in apache modules:
68:
69: my $perlvarref = LONCAPA::Configuration::read_conf('loncapa.conf');
70: my %perlvar = %{$perlvarref};
71:
72: #
73: # parent and shared variables.
74:
1.83 albertel 75: my %ChildPid; # by pid -> host.
76: my %ChildHost; # by host.
1.62 foxr 77: my %listening_to; # Socket->host table for who the parent
78: # is listening to.
79: my %parent_dispatchers; # host-> listener watcher events.
1.1 foxr 80:
1.65 foxr 81: my %parent_handlers; # Parent signal handlers...
82:
1.9 foxr 83: my $MaxConnectionCount = 10; # Will get from config later.
1.1 foxr 84: my $ClientConnection = 0; # Uniquifier for client events.
85:
1.9 foxr 86: my $DebugLevel = 0;
1.29 foxr 87: my $NextDebugLevel= 2; # So Sigint can toggle this.
1.50 albertel 88: my $IdleTimeout= 600; # Wait 10 minutes before pruning connections.
1.1 foxr 89:
1.39 foxr 90: my $LogTransactions = 0; # When True, all transactions/replies get logged.
1.65 foxr 91: my $executable = $0; # Get the full path to me.
1.39 foxr 92:
1.1 foxr 93: #
94: # The variables below are only used by the child processes.
95: #
96: my $RemoteHost; # Name of host child is talking to.
1.81 albertel 97: my $RemoteHostId; # default lonid of host child is talking to.
1.82 albertel 98: my @all_host_ids;
1.20 albertel 99: my $UnixSocketDir= $perlvar{'lonSockDir'};
1.1 foxr 100: my $IdleConnections = Stack->new(); # Set of idle connections
101: my %ActiveConnections; # Connections to the remote lond.
1.7 foxr 102: my %ActiveTransactions; # LondTransactions in flight.
1.1 foxr 103: my %ActiveClients; # Serial numbers of active clients by socket.
104: my $WorkQueue = Queue->new(); # Queue of pending transactions.
105: my $ConnectionCount = 0;
1.4 foxr 106: my $IdleSeconds = 0; # Number of seconds idle.
1.9 foxr 107: my $Status = ""; # Current status string.
1.14 foxr 108: my $RecentLogEntry = "";
1.72 albertel 109: my $ConnectionRetries=5; # Number of connection retries allowed.
110: my $ConnectionRetriesLeft=5; # Number of connection retries remaining.
1.40 foxr 111: my $LondVersion = "unknown"; # Version of lond we talk with.
1.49 foxr 112: my $KeyMode = ""; # e.g. ssl, local, insecure from last connect.
1.54 foxr 113: my $LondConnecting = 0; # True when a connection is being built.
1.1 foxr 114:
1.60 foxr 115:
116:
1.62 foxr 117: my $I_am_child = 0; # True if this is the child process.
1.57 foxr 118:
1.1 foxr 119: #
1.9 foxr 120: # The hash below gives the HTML format for log messages
121: # given a severity.
122: #
123: my %LogFormats;
124:
1.45 albertel 125: $LogFormats{"CRITICAL"} = "<font color='red'>CRITICAL: %s</font>";
126: $LogFormats{"SUCCESS"} = "<font color='green'>SUCCESS: %s</font>";
127: $LogFormats{"INFO"} = "<font color='yellow'>INFO: %s</font>";
128: $LogFormats{"WARNING"} = "<font color='blue'>WARNING: %s</font>";
1.9 foxr 129: $LogFormats{"DEFAULT"} = " %s ";
130:
1.10 foxr 131:
1.57 foxr 132: # UpdateStatus;
133: # Update the idle status display to show how many connections
134: # are left, retries and other stuff.
135: #
136: sub UpdateStatus {
137: if ($ConnectionRetriesLeft > 0) {
138: ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
139: ." Retries remaining: ".$ConnectionRetriesLeft
140: ." ($KeyMode)");
141: } else {
142: ShowStatus(GetServerHost()." >> DEAD <<");
143: }
144: }
145:
1.10 foxr 146:
147: =pod
148:
149: =head2 LogPerm
150:
151: Makes an entry into the permanent log file.
152:
153: =cut
1.69 matthew 154:
1.10 foxr 155: sub LogPerm {
156: my $message=shift;
157: my $execdir=$perlvar{'lonDaemons'};
158: my $now=time;
159: my $local=localtime($now);
160: my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
1.86 albertel 161: chomp($message);
1.10 foxr 162: print $fh "$now:$message:$local\n";
163: }
1.9 foxr 164:
165: =pod
166:
167: =head2 Log
168:
169: Logs a message to the log file.
170: Parameters:
171:
172: =item severity
173:
174: One of CRITICAL, WARNING, INFO, SUCCESS used to select the
175: format string used to format the message. if the severity is
176: not a defined severity the Default format string is used.
177:
178: =item message
179:
180: The base message. In addtion to the format string, the message
181: will be appended to a string containing the name of our remote
182: host and the time will be formatted into the message.
183:
184: =cut
185:
186: sub Log {
1.47 foxr 187:
188: my ($severity, $message) = @_;
189:
1.9 foxr 190: if(!$LogFormats{$severity}) {
191: $severity = "DEFAULT";
192: }
193:
194: my $format = $LogFormats{$severity};
195:
196: # Put the window dressing in in front of the message format:
197:
198: my $now = time;
199: my $local = localtime($now);
200: my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
1.76 albertel 201: $finalformat = $finalformat.$format."\n";
1.9 foxr 202:
203: # open the file and put the result.
204:
205: my $execdir = $perlvar{'lonDaemons'};
206: my $fh = IO::File->new(">>$execdir/logs/lonc.log");
207: my $msg = sprintf($finalformat, $message);
1.14 foxr 208: $RecentLogEntry = $msg;
1.9 foxr 209: print $fh $msg;
210:
1.10 foxr 211:
1.9 foxr 212: }
1.6 foxr 213:
1.3 albertel 214:
1.1 foxr 215: =pod
1.3 albertel 216:
217: =head2 GetPeerName
218:
219: Returns the name of the host that a socket object is connected to.
220:
1.1 foxr 221: =cut
222:
223: sub GetPeername {
1.47 foxr 224:
225:
226: my ($connection, $AdrFamily) = @_;
227:
1.1 foxr 228: my $peer = $connection->peername();
229: my $peerport;
230: my $peerip;
231: if($AdrFamily == AF_INET) {
232: ($peerport, $peerip) = sockaddr_in($peer);
1.23 foxr 233: my $peername = gethostbyaddr($peerip, $AdrFamily);
1.1 foxr 234: return $peername;
235: } elsif ($AdrFamily == AF_UNIX) {
236: my $peerfile;
237: ($peerfile) = sockaddr_un($peer);
238: return $peerfile;
239: }
240: }
241: =pod
1.3 albertel 242:
1.1 foxr 243: =head2 Debug
1.3 albertel 244:
245: Invoked to issue a debug message.
246:
1.1 foxr 247: =cut
1.3 albertel 248:
1.1 foxr 249: sub Debug {
1.47 foxr 250:
251: my ($level, $message) = @_;
252:
1.1 foxr 253: if ($level <= $DebugLevel) {
1.23 foxr 254: Log("INFO", "-Debug- $message host = $RemoteHost");
1.1 foxr 255: }
256: }
257:
258: sub SocketDump {
1.47 foxr 259:
260: my ($level, $socket) = @_;
261:
1.1 foxr 262: if($level <= $DebugLevel) {
1.48 foxr 263: $socket->Dump(-1); # Ensure it will get dumped.
1.1 foxr 264: }
265: }
1.3 albertel 266:
1.1 foxr 267: =pod
1.3 albertel 268:
1.5 foxr 269: =head2 ShowStatus
270:
271: Place some text as our pid status.
1.10 foxr 272: and as what we return in a SIGUSR1
1.5 foxr 273:
274: =cut
1.69 matthew 275:
1.5 foxr 276: sub ShowStatus {
1.10 foxr 277: my $state = shift;
278: my $now = time;
279: my $local = localtime($now);
280: $Status = $local.": ".$state;
281: $0='lonc: '.$state.' '.$local;
1.5 foxr 282: }
283:
284: =pod
285:
1.69 matthew 286: =head2 SocketTimeout
1.15 foxr 287:
288: Called when an action on the socket times out. The socket is
289: destroyed and any active transaction is failed.
290:
291:
292: =cut
1.69 matthew 293:
1.15 foxr 294: sub SocketTimeout {
295: my $Socket = shift;
1.38 foxr 296: Log("WARNING", "A socket timeout was detected");
1.52 foxr 297: Debug(5, " SocketTimeout called: ");
1.48 foxr 298: $Socket->Dump(0);
1.42 foxr 299: if(exists($ActiveTransactions{$Socket})) {
1.43 albertel 300: FailTransaction($ActiveTransactions{$Socket});
1.42 foxr 301: }
1.22 foxr 302: KillSocket($Socket); # A transaction timeout also counts as
303: # a connection failure:
304: $ConnectionRetriesLeft--;
1.42 foxr 305: if($ConnectionRetriesLeft <= 0) {
1.52 foxr 306: Log("CRITICAL", "Host marked DEAD: ".GetServerHost());
1.56 foxr 307: $LondConnecting = 0;
1.42 foxr 308: }
309:
1.15 foxr 310: }
1.80 albertel 311:
1.64 foxr 312: #
313: # This function should be called by the child in all cases where it must
1.80 albertel 314: # exit. The child process must create a lock file for the AF_UNIX socket
315: # in order to prevent connection requests from lonnet in the time between
316: # process exit and the parent picking up the listen again.
317: #
1.64 foxr 318: # Parameters:
319: # exit_code - Exit status value, however see the next parameter.
320: # message - If this optional parameter is supplied, the exit
321: # is via a die with this message.
322: #
323: sub child_exit {
324: my ($exit_code, $message) = @_;
325:
326: # Regardless of how we exit, we may need to do the lock thing:
327:
1.80 albertel 328: #
329: # Create a lock file since there will be a time window
330: # between our exit and the parent's picking up the listen
331: # during which no listens will be done on the
332: # lonnet client socket.
333: #
334: my $lock_file = &GetLoncSocketPath().".lock";
335: open(LOCK,">$lock_file");
336: print LOCK "Contents not important";
337: close(LOCK);
1.81 albertel 338: unlink(&GetLoncSocketPath());
1.64 foxr 339:
1.80 albertel 340: if ($message) {
341: die($message);
1.64 foxr 342: } else {
343: exit($exit_code);
344: }
345: }
1.35 foxr 346: #----------------------------- Timer management ------------------------
1.15 foxr 347:
348: =pod
349:
1.1 foxr 350: =head2 Tick
1.3 albertel 351:
352: Invoked each timer tick.
353:
1.1 foxr 354: =cut
355:
1.5 foxr 356:
1.1 foxr 357: sub Tick {
1.52 foxr 358: my ($Event) = @_;
359: my $clock_watcher = $Event->w;
360:
1.1 foxr 361: my $client;
1.57 foxr 362: UpdateStatus();
363:
1.4 foxr 364: # Is it time to prune connection count:
365:
366:
367: if($IdleConnections->Count() &&
368: ($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
1.52 foxr 369: $IdleSeconds++;
1.4 foxr 370: if($IdleSeconds > $IdleTimeout) { # Prune a connection...
1.23 foxr 371: my $Socket = $IdleConnections->pop();
1.6 foxr 372: KillSocket($Socket);
1.54 foxr 373: $IdleSeconds = 0; # Otherwise all connections get trimmed to fast.
1.57 foxr 374: UpdateStatus();
1.80 albertel 375: if(($ConnectionCount == 0)) {
1.64 foxr 376: &child_exit(0);
377:
1.57 foxr 378: }
1.4 foxr 379: }
380: } else {
381: $IdleSeconds = 0; # Reset idle count if not idle.
382: }
1.15 foxr 383: #
384: # For each inflight transaction, tick down its timeout counter.
385: #
1.35 foxr 386:
1.34 albertel 387: foreach my $item (keys %ActiveConnections) {
388: my $State = $ActiveConnections{$item}->data->GetState();
1.35 foxr 389: if ($State ne 'Idle') {
1.34 albertel 390: Debug(5,"Ticking Socket $State $item");
391: $ActiveConnections{$item}->data->Tick();
392: }
1.15 foxr 393: }
1.5 foxr 394: # Do we have work in the queue, but no connections to service them?
395: # If so, try to make some new connections to get things going again.
396: #
1.57 foxr 397: # Note this code is dead now...
398: #
1.5 foxr 399: my $Requests = $WorkQueue->Count();
1.56 foxr 400: if (($ConnectionCount == 0) && ($Requests > 0) && (!$LondConnecting)) {
1.10 foxr 401: if ($ConnectionRetriesLeft > 0) {
1.56 foxr 402: Debug(5,"Work but no connections, Make a new one");
403: my $success;
404: $success = &MakeLondConnection;
405: if($success == 0) { # All connections failed:
1.29 foxr 406: Debug(5,"Work in queue failed to make any connectiouns\n");
1.22 foxr 407: EmptyQueue(); # Fail pending transactions with con_lost.
1.42 foxr 408: CloseAllLondConnections(); # Should all be closed but....
1.10 foxr 409: }
410: } else {
1.56 foxr 411: $LondConnecting = 0;
1.22 foxr 412: ShowStatus(GetServerHost()." >>> DEAD!!! <<<");
1.29 foxr 413: Debug(5,"Work in queue, but gave up on connections..flushing\n");
1.10 foxr 414: EmptyQueue(); # Connections can't be established.
1.42 foxr 415: CloseAllLondConnections(); # Should all already be closed but...
1.5 foxr 416: }
417:
418: }
1.49 foxr 419: if ($ConnectionCount == 0) {
420: $KeyMode = "";
1.52 foxr 421: $clock_watcher->cancel();
1.49 foxr 422: }
1.66 albertel 423: &UpdateStatus();
1.1 foxr 424: }
425:
426: =pod
1.3 albertel 427:
1.1 foxr 428: =head2 SetupTimer
429:
1.3 albertel 430: Sets up a 1 per sec recurring timer event. The event handler is used to:
1.1 foxr 431:
1.3 albertel 432: =item
433:
434: Trigger timeouts on communications along active sockets.
435:
436: =item
437:
438: Trigger disconnections of idle sockets.
1.1 foxr 439:
440: =cut
441:
442: sub SetupTimer {
1.52 foxr 443: Debug(6, "SetupTimer");
444: Event->timer(interval => 1, cb => \&Tick );
1.1 foxr 445: }
1.3 albertel 446:
1.1 foxr 447: =pod
1.3 albertel 448:
1.1 foxr 449: =head2 ServerToIdle
1.3 albertel 450:
451: This function is called when a connection to the server is
452: ready for more work.
453:
454: If there is work in the Work queue the top element is dequeued
1.1 foxr 455: and the connection will start to work on it. If the work queue is
456: empty, the connection is pushed on the idle connection stack where
457: it will either get another work unit, or alternatively, if it sits there
458: long enough, it will be shut down and released.
459:
1.3 albertel 460: =cut
1.1 foxr 461:
462: sub ServerToIdle {
463: my $Socket = shift; # Get the socket.
1.49 foxr 464: $KeyMode = $Socket->{AuthenticationMode};
1.7 foxr 465: delete($ActiveTransactions{$Socket}); # Server has no transaction
1.1 foxr 466:
1.29 foxr 467: &Debug(5, "Server to idle");
1.1 foxr 468:
469: # If there's work to do, start the transaction:
470:
1.23 foxr 471: my $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
1.29 foxr 472: if ($reqdata ne undef) {
473: Debug(5, "Queue gave request data: ".$reqdata->getRequest());
1.7 foxr 474: &StartRequest($Socket, $reqdata);
1.8 foxr 475:
1.1 foxr 476: } else {
477:
478: # There's no work waiting, so push the server to idle list.
1.29 foxr 479: &Debug(5, "No new work requests, server connection going idle");
1.1 foxr 480: $IdleConnections->push($Socket);
481: }
482: }
1.3 albertel 483:
1.1 foxr 484: =pod
1.3 albertel 485:
1.1 foxr 486: =head2 ClientWritable
1.3 albertel 487:
488: Event callback for when a client socket is writable.
489:
490: This callback is established when a transaction reponse is
491: avaiable from lond. The response is forwarded to the unix socket
492: as it becomes writable in this sub.
493:
1.1 foxr 494: Parameters:
495:
1.3 albertel 496: =item Event
497:
498: The event that has been triggered. Event->w->data is
499: the data and Event->w->fd is the socket to write.
1.1 foxr 500:
501: =cut
1.3 albertel 502:
1.1 foxr 503: sub ClientWritable {
504: my $Event = shift;
505: my $Watcher = $Event->w;
1.84 albertel 506: if (!defined($Watcher)) {
507: &child_exit(-1,'No watcher for event in ClientWritable');
508: }
1.1 foxr 509: my $Data = $Watcher->data;
510: my $Socket = $Watcher->fd;
511:
512: # Try to send the data:
513:
514: &Debug(6, "ClientWritable writing".$Data);
515: &Debug(9, "Socket is: ".$Socket);
516:
1.6 foxr 517: if($Socket->connected) {
518: my $result = $Socket->send($Data, 0);
519:
520: # $result undefined: the write failed.
521: # otherwise $result is the number of bytes written.
522: # Remove that preceding string from the data.
523: # If the resulting data is empty, destroy the watcher
524: # and set up a read event handler to accept the next
525: # request.
526:
527: &Debug(9,"Send result is ".$result." Defined: ".defined($result));
1.29 foxr 528: if($result ne undef) {
1.6 foxr 529: &Debug(9, "send result was defined");
530: if($result == length($Data)) { # Entire string sent.
531: &Debug(9, "ClientWritable data all written");
532: $Watcher->cancel();
533: #
534: # Set up to read next request from socket:
535:
536: my $descr = sprintf("Connection to lonc client %d",
537: $ActiveClients{$Socket});
538: Event->io(cb => \&ClientRequest,
539: poll => 'r',
540: desc => $descr,
541: data => "",
542: fd => $Socket);
543:
544: } else { # Partial string sent.
545: $Watcher->data(substr($Data, $result));
1.15 foxr 546: if($result == 0) { # client hung up on us!!
1.52 foxr 547: # Log("INFO", "lonc pipe client hung up on us!");
1.15 foxr 548: $Watcher->cancel;
549: $Socket->shutdown(2);
550: $Socket->close();
551: }
1.6 foxr 552: }
553:
554: } else { # Error of some sort...
555:
556: # Some errnos are possible:
557: my $errno = $!;
558: if($errno == POSIX::EWOULDBLOCK ||
559: $errno == POSIX::EAGAIN ||
560: $errno == POSIX::EINTR) {
561: # No action taken?
562: } else { # Unanticipated errno.
563: &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
564: $Watcher->cancel; # Stop the watcher.
565: $Socket->shutdown(2); # Kill connection
566: $Socket->close(); # Close the socket.
567: }
1.1 foxr 568:
569: }
1.6 foxr 570: } else {
571: $Watcher->cancel(); # A delayed request...just cancel.
1.84 albertel 572: return;
1.1 foxr 573: }
574: }
575:
576: =pod
1.3 albertel 577:
1.1 foxr 578: =head2 CompleteTransaction
1.3 albertel 579:
580: Called when the reply data has been received for a lond
1.1 foxr 581: transaction. The reply data must now be sent to the
582: ultimate client on the other end of the Unix socket. This is
583: done by setting up a writable event for the socket with the
584: data the reply data.
1.3 albertel 585:
1.1 foxr 586: Parameters:
1.3 albertel 587:
588: =item Socket
589:
590: Socket on which the lond transaction occured. This is a
591: LondConnection. The data received is in the TransactionReply member.
592:
1.7 foxr 593: =item Transaction
1.3 albertel 594:
1.7 foxr 595: The transaction that is being completed.
1.1 foxr 596:
597: =cut
1.3 albertel 598:
1.1 foxr 599: sub CompleteTransaction {
1.29 foxr 600: &Debug(5,"Complete transaction");
1.47 foxr 601:
602: my ($Socket, $Transaction) = @_;
1.1 foxr 603:
1.7 foxr 604: if (!$Transaction->isDeferred()) { # Normal transaction
605: my $data = $Socket->GetReply(); # Data to send.
1.39 foxr 606: if($LogTransactions) {
607: Log("SUCCESS", "Reply from lond: '$data'");
608: }
1.7 foxr 609: StartClientReply($Transaction, $data);
610: } else { # Delete deferred transaction file.
1.9 foxr 611: Log("SUCCESS", "A delayed transaction was completed");
1.86 albertel 612: LogPerm("S:".$Transaction->getClient().":".$Transaction->getRequest());
613: unlink($Transaction->getFile());
1.7 foxr 614: }
1.6 foxr 615: }
1.42 foxr 616:
1.6 foxr 617: =pod
1.42 foxr 618:
1.6 foxr 619: =head1 StartClientReply
620:
621: Initiates a reply to a client where the reply data is a parameter.
622:
1.7 foxr 623: =head2 parameters:
624:
625: =item Transaction
626:
627: The transaction for which we are responding to the client.
628:
629: =item data
630:
631: The data to send to apached client.
632:
1.6 foxr 633: =cut
1.42 foxr 634:
1.6 foxr 635: sub StartClientReply {
1.1 foxr 636:
1.47 foxr 637: my ($Transaction, $data) = @_;
1.12 foxr 638:
1.7 foxr 639: my $Client = $Transaction->getClient();
640:
1.1 foxr 641: &Debug(8," Reply was: ".$data);
642: my $Serial = $ActiveClients{$Client};
643: my $desc = sprintf("Connection to lonc client %d",
644: $Serial);
645: Event->io(fd => $Client,
646: poll => "w",
647: desc => $desc,
648: cb => \&ClientWritable,
649: data => $data);
650: }
1.42 foxr 651:
1.4 foxr 652: =pod
1.42 foxr 653:
1.4 foxr 654: =head2 FailTransaction
655:
656: Finishes a transaction with failure because the associated lond socket
1.7 foxr 657: disconnected. There are two possibilities:
658: - The transaction is deferred: in which case we just quietly
659: delete the transaction since there is no client connection.
660: - The transaction is 'live' in which case we initiate the sending
661: of "con_lost" to the client.
662:
1.42 foxr 663: Deleting the transaction means killing it from the %ActiveTransactions hash.
1.4 foxr 664:
665: Parameters:
666:
667: =item client
668:
1.7 foxr 669: The LondTransaction we are failing.
670:
1.42 foxr 671:
1.4 foxr 672: =cut
673:
674: sub FailTransaction {
1.7 foxr 675: my $transaction = shift;
1.52 foxr 676:
677: # If the socket is dead, that's already logged.
678:
679: if ($ConnectionRetriesLeft > 0) {
680: Log("WARNING", "Failing transaction "
1.71 albertel 681: .$transaction->getLoggableRequest());
1.52 foxr 682: }
1.71 albertel 683: Debug(1, "Failing transaction: ".$transaction->getLoggableRequest());
1.10 foxr 684: if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
1.11 foxr 685: my $client = $transaction->getClient();
1.30 foxr 686: Debug(1," Replying con_lost to ".$transaction->getRequest());
1.11 foxr 687: StartClientReply($transaction, "con_lost\n");
1.7 foxr 688: }
1.4 foxr 689:
690: }
691:
692: =pod
1.69 matthew 693:
1.6 foxr 694: =head1 EmptyQueue
1.7 foxr 695:
1.6 foxr 696: Fails all items in the work queue with con_lost.
1.7 foxr 697: Note that each item in the work queue is a transaction.
698:
1.6 foxr 699: =cut
1.69 matthew 700:
1.6 foxr 701: sub EmptyQueue {
1.22 foxr 702: $ConnectionRetriesLeft--; # Counts as connection failure too.
1.6 foxr 703: while($WorkQueue->Count()) {
1.10 foxr 704: my $request = $WorkQueue->dequeue(); # This is a transaction
1.7 foxr 705: FailTransaction($request);
1.6 foxr 706: }
707: }
708:
709: =pod
1.4 foxr 710:
1.9 foxr 711: =head2 CloseAllLondConnections
712:
713: Close all connections open on lond prior to exit e.g.
714:
715: =cut
1.69 matthew 716:
1.9 foxr 717: sub CloseAllLondConnections {
1.23 foxr 718: foreach my $Socket (keys %ActiveConnections) {
1.42 foxr 719: if(exists($ActiveTransactions{$Socket})) {
720: FailTransaction($ActiveTransactions{$Socket});
721: }
722: KillSocket($Socket);
1.9 foxr 723: }
724: }
725:
726: =pod
727:
1.4 foxr 728: =head2 KillSocket
729:
730: Destroys a socket. This function can be called either when a socket
731: has died of 'natural' causes or because a socket needs to be pruned due to
732: idleness. If the socket has died naturally, if there are no longer any
733: live connections a new connection is created (in case there are transactions
734: in the queue). If the socket has been pruned, it is never re-created.
735:
736: Parameters:
1.1 foxr 737:
1.4 foxr 738: =item Socket
739:
740: The socket to kill off.
741:
742: =item Restart
743:
744: nonzero if we are allowed to create a new connection.
745:
1.69 matthew 746: =cut
1.4 foxr 747:
748: sub KillSocket {
749: my $Socket = shift;
750:
1.17 foxr 751: Log("WARNING", "Shutting down a socket");
1.9 foxr 752: $Socket->Shutdown();
753:
1.7 foxr 754: # If the socket came from the active connection set,
755: # delete its transaction... note that FailTransaction should
756: # already have been called!!!
757: # otherwise it came from the idle set.
758: #
1.4 foxr 759:
760: if(exists($ActiveTransactions{$Socket})) {
761: delete ($ActiveTransactions{$Socket});
762: }
763: if(exists($ActiveConnections{$Socket})) {
764: delete($ActiveConnections{$Socket});
1.37 albertel 765: $ConnectionCount--;
766: if ($ConnectionCount < 0) { $ConnectionCount = 0; }
1.4 foxr 767: }
1.6 foxr 768: # If the connection count has gone to zero and there is work in the
769: # work queue, the work all gets failed with con_lost.
770: #
771: if($ConnectionCount == 0) {
1.22 foxr 772: EmptyQueue();
1.42 foxr 773: CloseAllLondConnections; # Should all already be closed but...
1.4 foxr 774: }
775: }
1.1 foxr 776:
777: =pod
1.3 albertel 778:
1.1 foxr 779: =head2 LondReadable
1.3 albertel 780:
1.1 foxr 781: This function is called whenever a lond connection
782: is readable. The action is state dependent:
783:
1.3 albertel 784: =head3 State=Initialized
785:
786: We''re waiting for the challenge, this is a no-op until the
1.1 foxr 787: state changes.
1.3 albertel 788:
1.1 foxr 789: =head3 State=Challenged
1.3 albertel 790:
791: The challenge has arrived we need to transition to Writable.
1.1 foxr 792: The connection must echo the challenge back.
1.3 albertel 793:
1.1 foxr 794: =head3 State=ChallengeReplied
1.3 albertel 795:
796: The challenge has been replied to. The we are receiveing the
1.1 foxr 797: 'ok' from the partner.
1.3 albertel 798:
1.40 foxr 799: =head3 State=ReadingVersionString
800:
801: We have requested the lond version and are reading the
802: version back. Upon completion, we'll store the version away
803: for future use(?).
804:
805: =head3 State=HostSet
806:
807: We have selected the domain name of our peer (multhomed hosts)
808: and are getting the reply (presumably ok) back.
809:
1.1 foxr 810: =head3 State=RequestingKey
1.3 albertel 811:
812: The ok has been received and we need to send the request for
1.1 foxr 813: an encryption key. Transition to writable for that.
1.3 albertel 814:
1.1 foxr 815: =head3 State=ReceivingKey
1.3 albertel 816:
817: The the key has been requested, now we are reading the new key.
818:
1.1 foxr 819: =head3 State=Idle
1.3 albertel 820:
821: The encryption key has been negotiated or we have finished
1.1 foxr 822: reading data from the a transaction. If the callback data has
823: a client as well as the socket iformation, then we are
824: doing a transaction and the data received is relayed to the client
825: before the socket is put on the idle list.
1.3 albertel 826:
1.1 foxr 827: =head3 State=SendingRequest
1.3 albertel 828:
829: I do not think this state can be received here, but if it is,
1.1 foxr 830: the appropriate thing to do is to transition to writable, and send
831: the request.
1.3 albertel 832:
1.1 foxr 833: =head3 State=ReceivingReply
1.3 albertel 834:
835: We finished sending the request to the server and now transition
1.1 foxr 836: to readable to receive the reply.
837:
838: The parameter to this function are:
1.3 albertel 839:
1.1 foxr 840: The event. Implicit in this is the watcher and its data. The data
841: contains at least the lond connection object and, if a
842: transaction is in progress, the socket attached to the local client.
843:
1.3 albertel 844: =cut
1.1 foxr 845:
846: sub LondReadable {
1.8 foxr 847:
1.41 albertel 848: my $Event = shift;
849: my $Watcher = $Event->w;
850: my $Socket = $Watcher->data;
851: my $client = undef;
1.40 foxr 852:
1.41 albertel 853: &Debug(6,"LondReadable called state = ".$Socket->GetState());
1.40 foxr 854:
855:
1.41 albertel 856: my $State = $Socket->GetState(); # All action depends on the state.
1.40 foxr 857:
1.41 albertel 858: SocketDump(6, $Socket);
859: my $status = $Socket->Readable();
1.40 foxr 860:
1.41 albertel 861: &Debug(2, "Socket->Readable returned: $status");
1.40 foxr 862:
1.41 albertel 863: if($status != 0) {
864: # bad return from socket read. Currently this means that
865: # The socket has become disconnected. We fail the transaction.
1.40 foxr 866:
1.41 albertel 867: Log("WARNING",
868: "Lond connection lost.");
869: if(exists($ActiveTransactions{$Socket})) {
870: FailTransaction($ActiveTransactions{$Socket});
1.56 foxr 871: } else {
872: # Socket is connecting and failed... need to mark
873: # no longer connecting.
874:
875: $LondConnecting = 0;
1.41 albertel 876: }
877: $Watcher->cancel();
878: KillSocket($Socket);
879: $ConnectionRetriesLeft--; # Counts as connection failure
880: return;
881: }
882: SocketDump(6,$Socket);
1.17 foxr 883:
1.41 albertel 884: $State = $Socket->GetState(); # Update in case of transition.
885: &Debug(6, "After read, state is ".$State);
1.1 foxr 886:
1.41 albertel 887: if($State eq "Initialized") {
1.1 foxr 888:
889:
1.41 albertel 890: } elsif ($State eq "ChallengeReceived") {
1.1 foxr 891: # The challenge must be echoed back; The state machine
892: # in the connection takes care of setting that up. Just
893: # need to transition to writable:
1.41 albertel 894:
895: $Watcher->cb(\&LondWritable);
896: $Watcher->poll("w");
1.1 foxr 897:
1.41 albertel 898: } elsif ($State eq "ChallengeReplied") {
1.1 foxr 899:
1.41 albertel 900: } elsif ($State eq "RequestingVersion") {
901: # Need to ask for the version... that is writiability:
1.1 foxr 902:
1.41 albertel 903: $Watcher->cb(\&LondWritable);
904: $Watcher->poll("w");
905:
906: } elsif ($State eq "ReadingVersionString") {
907: # Read the rest of the version string...
908: } elsif ($State eq "SetHost") {
909: # Need to request the actual domain get set...
910:
911: $Watcher->cb(\&LondWritable);
912: $Watcher->poll("w");
913: } elsif ($State eq "HostSet") {
914: # Reading the 'ok' from the peer.
915:
916: } elsif ($State eq "RequestingKey") {
1.1 foxr 917: # The ok was received. Now we need to request the key
918: # That requires us to be writable:
919:
1.41 albertel 920: $Watcher->cb(\&LondWritable);
921: $Watcher->poll("w");
1.1 foxr 922:
1.41 albertel 923: } elsif ($State eq "ReceivingKey") {
1.1 foxr 924:
1.41 albertel 925: } elsif ($State eq "Idle") {
1.40 foxr 926:
1.41 albertel 927: # This is as good a spot as any to get the peer version
928: # string:
1.40 foxr 929:
1.41 albertel 930: if($LondVersion eq "unknown") {
931: $LondVersion = $Socket->PeerVersion();
932: Log("INFO", "Connected to lond version: $LondVersion");
933: }
1.1 foxr 934: # If necessary, complete a transaction and then go into the
935: # idle queue.
1.22 foxr 936: # Note that a trasition to idle indicates a live lond
937: # on the other end so reset the connection retries.
938: #
1.41 albertel 939: $ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
940: $Watcher->cancel();
941: if(exists($ActiveTransactions{$Socket})) {
942: Debug(5,"Completing transaction!!");
943: CompleteTransaction($Socket,
944: $ActiveTransactions{$Socket});
945: } else {
946: Log("SUCCESS", "Connection ".$ConnectionCount." to "
947: .$RemoteHost." now ready for action");
948: }
949: ServerToIdle($Socket); # Next work unit or idle.
1.54 foxr 950:
951: #
952: $LondConnecting = 0; # Best spot I can think of for this.
953: #
1.6 foxr 954:
1.41 albertel 955: } elsif ($State eq "SendingRequest") {
1.1 foxr 956: # We need to be writable for this and probably don't belong
957: # here inthe first place.
958:
1.73 albertel 959: Debug(6, "SendingRequest state encountered in readable");
1.41 albertel 960: $Watcher->poll("w");
961: $Watcher->cb(\&LondWritable);
1.1 foxr 962:
1.41 albertel 963: } elsif ($State eq "ReceivingReply") {
1.1 foxr 964:
965:
1.41 albertel 966: } else {
967: # Invalid state.
968: Debug(4, "Invalid state in LondReadable");
969: }
1.1 foxr 970: }
1.3 albertel 971:
1.1 foxr 972: =pod
1.3 albertel 973:
1.1 foxr 974: =head2 LondWritable
1.3 albertel 975:
1.1 foxr 976: This function is called whenever a lond connection
977: becomes writable while there is a writeable monitoring
978: event. The action taken is very state dependent:
1.3 albertel 979:
1.1 foxr 980: =head3 State = Connected
1.3 albertel 981:
982: The connection is in the process of sending the 'init' hailing to the
983: lond on the remote end. The connection object''s Writable member is
984: called. On error, ConnectionError is called to destroy the connection
985: and remove it from the ActiveConnections hash
986:
1.1 foxr 987: =head3 Initialized
1.3 albertel 988:
989: 'init' has been sent, writability monitoring is removed and
990: readability monitoring is started with LondReadable as the callback.
991:
1.1 foxr 992: =head3 ChallengeReceived
1.3 albertel 993:
994: The connection has received the who are you challenge from the remote
995: system, and is in the process of sending the challenge
996: response. Writable is called.
997:
1.1 foxr 998: =head3 ChallengeReplied
1.3 albertel 999:
1000: The connection has replied to the initial challenge The we switch to
1001: monitoring readability looking for the server to reply with 'ok'.
1002:
1.1 foxr 1003: =head3 RequestingKey
1.3 albertel 1004:
1005: The connection is in the process of requesting its encryption key.
1006: Writable is called.
1007:
1.1 foxr 1008: =head3 ReceivingKey
1.3 albertel 1009:
1010: The connection has sent the request for a key. Switch to readability
1011: monitoring to accept the key
1012:
1.1 foxr 1013: =head3 SendingRequest
1.3 albertel 1014:
1015: The connection is in the process of sending a request to the server.
1016: This request is part of a client transaction. All the states until
1017: now represent the client setup protocol. Writable is called.
1018:
1.1 foxr 1019: =head3 ReceivingReply
1020:
1.3 albertel 1021: The connection has sent a request. Now it must receive a reply.
1022: Readability monitoring is requested.
1023:
1024: This function is an event handler and therefore receives as
1.1 foxr 1025: a parameter the event that has fired. The data for the watcher
1026: of this event is a reference to a list of one or two elements,
1027: depending on state. The first (and possibly only) element is the
1028: socket. The second (present only if a request is in progress)
1029: is the socket on which to return a reply to the caller.
1030:
1031: =cut
1.3 albertel 1032:
1.1 foxr 1033: sub LondWritable {
1034: my $Event = shift;
1035: my $Watcher = $Event->w;
1.8 foxr 1036: my $Socket = $Watcher->data;
1037: my $State = $Socket->GetState();
1.1 foxr 1038:
1.8 foxr 1039: Debug(6,"LondWritable State = ".$State."\n");
1.1 foxr 1040:
1.8 foxr 1041:
1.1 foxr 1042: # Figure out what to do depending on the state of the socket:
1043:
1044:
1045:
1046:
1047: SocketDump(6,$Socket);
1048:
1.42 foxr 1049: # If the socket is writable, we must always write.
1050: # Only by writing will we undergo state transitions.
1051: # Old logic wrote in state specific code below, however
1052: # That forces us at least through another invocation of
1053: # this function after writability is possible again.
1054: # This logic also factors out common code for handling
1055: # write failures... in all cases, write failures
1056: # Kill the socket.
1057: # This logic makes the branches of the >big< if below
1058: # so that the writing states are actually NO-OPs.
1059:
1060: if ($Socket->Writable() != 0) {
1.43 albertel 1061: # The write resulted in an error.
1062: # We'll treat this as if the socket got disconnected:
1063: Log("WARNING", "Connection to ".$RemoteHost.
1064: " has been disconnected");
1065: if(exists($ActiveTransactions{$Socket})) {
1066: FailTransaction($ActiveTransactions{$Socket});
1.56 foxr 1067: } else {
1068: # In the process of conneting, so need to turn that off.
1069:
1070: $LondConnecting = 0;
1.43 albertel 1071: }
1072: $Watcher->cancel();
1073: KillSocket($Socket);
1074: return;
1.42 foxr 1075: }
1076:
1077:
1078:
1.41 albertel 1079: if ($State eq "Connected") {
1.1 foxr 1080:
1.41 albertel 1081: # "init" is being sent...
1.42 foxr 1082:
1.41 albertel 1083: } elsif ($State eq "Initialized") {
1.4 foxr 1084:
1.41 albertel 1085: # Now that init was sent, we switch
1086: # to watching for readability:
1.1 foxr 1087:
1.41 albertel 1088: $Watcher->cb(\&LondReadable);
1089: $Watcher->poll("r");
1090:
1091: } elsif ($State eq "ChallengeReceived") {
1092: # We received the challenge, now we
1093: # are echoing it back. This is a no-op,
1094: # we're waiting for the state to change
1.1 foxr 1095:
1.41 albertel 1096: } elsif ($State eq "ChallengeReplied") {
1097: # The echo was sent back, so we switch
1098: # to watching readability.
1099:
1100: $Watcher->cb(\&LondReadable);
1101: $Watcher->poll("r");
1102: } elsif ($State eq "RequestingVersion") {
1103: # Sending the peer a version request...
1.42 foxr 1104:
1.41 albertel 1105: } elsif ($State eq "ReadingVersionString") {
1106: # Transition to read since we have sent the
1107: # version command and now just need to read the
1108: # version string from the peer:
1.40 foxr 1109:
1.41 albertel 1110: $Watcher->cb(\&LondReadable);
1111: $Watcher->poll("r");
1.40 foxr 1112:
1.41 albertel 1113: } elsif ($State eq "SetHost") {
1114: # Setting the remote domain...
1.42 foxr 1115:
1.41 albertel 1116: } elsif ($State eq "HostSet") {
1117: # Back to readable to get the ok.
1.40 foxr 1118:
1.41 albertel 1119: $Watcher->cb(\&LondReadable);
1120: $Watcher->poll("r");
1.40 foxr 1121:
1122:
1.41 albertel 1123: } elsif ($State eq "RequestingKey") {
1124: # At this time we're requesting the key.
1125: # again, this is essentially a no-op.
1126:
1127: } elsif ($State eq "ReceivingKey") {
1128: # Now we need to wait for the key
1129: # to come back from the peer:
1130:
1131: $Watcher->cb(\&LondReadable);
1132: $Watcher->poll("r");
1133:
1134: } elsif ($State eq "SendingRequest") {
1.40 foxr 1135:
1.41 albertel 1136: # At this time we are sending a request to the
1.1 foxr 1137: # peer... write the next chunk:
1138:
1.41 albertel 1139:
1140: } elsif ($State eq "ReceivingReply") {
1141: # The send has completed. Wait for the
1142: # data to come in for a reply.
1143: Debug(8,"Writable sent request/receiving reply");
1144: $Watcher->cb(\&LondReadable);
1145: $Watcher->poll("r");
1.1 foxr 1146:
1.41 albertel 1147: } else {
1148: # Control only passes here on an error:
1149: # the socket state does not match any
1150: # of the known states... so an error
1151: # must be logged.
1.1 foxr 1152:
1.41 albertel 1153: &Debug(4, "Invalid socket state ".$State."\n");
1154: }
1.1 foxr 1155:
1156: }
1.81 albertel 1157:
1.6 foxr 1158: =pod
1159:
1160: =cut
1.69 matthew 1161:
1.81 albertel 1162:
1.6 foxr 1163: sub QueueDelayed {
1.8 foxr 1164: Debug(3,"QueueDelayed called");
1165:
1.6 foxr 1166: my $path = "$perlvar{'lonSockDir'}/delayed";
1.8 foxr 1167:
1168: Debug(4, "Delayed path: ".$path);
1.6 foxr 1169: opendir(DIRHANDLE, $path);
1.75 albertel 1170:
1.82 albertel 1171: my $host_id_re = '(?:'.join('|',map {quotemeta($_)} (@all_host_ids)).')';
1.75 albertel 1172: my @alldelayed = grep(/\.$host_id_re$/, readdir(DIRHANDLE));
1.6 foxr 1173: closedir(DIRHANDLE);
1.75 albertel 1174: foreach my $dfname (sort(@alldelayed)) {
1175: my $reqfile = "$path/$dfname";
1176: my ($host_id) = ($dfname =~ /\.([^.]*)$/);
1177: Debug(4, "queueing ".$reqfile." for $host_id");
1.6 foxr 1178: my $Handle = IO::File->new($reqfile);
1179: my $cmd = <$Handle>;
1.8 foxr 1180: chomp $cmd; # There may or may not be a newline...
1.12 foxr 1181: $cmd = $cmd."\n"; # now for sure there's exactly one newline.
1.75 albertel 1182: my $Transaction = LondTransaction->new("sethost:$host_id:$cmd");
1.7 foxr 1183: $Transaction->SetDeferred($reqfile);
1184: QueueTransaction($Transaction);
1.6 foxr 1185: }
1186:
1187: }
1.1 foxr 1188:
1189: =pod
1.3 albertel 1190:
1.1 foxr 1191: =head2 MakeLondConnection
1.3 albertel 1192:
1193: Create a new lond connection object, and start it towards its initial
1194: idleness. Once idle, it becomes elligible to receive transactions
1195: from the work queue. If the work queue is not empty when the
1196: connection is completed and becomes idle, it will dequeue an entry and
1197: start off on it.
1198:
1.1 foxr 1199: =cut
1.3 albertel 1200:
1.1 foxr 1201: sub MakeLondConnection {
1202: Debug(4,"MakeLondConnection to ".GetServerHost()." on port "
1203: .GetServerPort());
1204:
1205: my $Connection = LondConnection->new(&GetServerHost(),
1.81 albertel 1206: &GetServerPort(),
1207: &GetHostId());
1.1 foxr 1208:
1.30 foxr 1209: if($Connection eq undef) { # Needs to be more robust later.
1.9 foxr 1210: Log("CRITICAL","Failed to make a connection with lond.");
1.10 foxr 1211: $ConnectionRetriesLeft--;
1212: return 0; # Failure.
1.5 foxr 1213: } else {
1.22 foxr 1214:
1.82 albertel 1215: $LondConnecting = 1; # Connection in progress.
1.5 foxr 1216: # The connection needs to have writability
1217: # monitored in order to send the init sequence
1218: # that starts the whole authentication/key
1219: # exchange underway.
1220: #
1221: my $Socket = $Connection->GetSocket();
1.30 foxr 1222: if($Socket eq undef) {
1.64 foxr 1223: &child_exit(-1, "did not get a socket from the connection");
1.5 foxr 1224: } else {
1225: &Debug(9,"MakeLondConnection got socket: ".$Socket);
1226: }
1.1 foxr 1227:
1.21 foxr 1228: $Connection->SetTimeoutCallback(\&SocketTimeout);
1229:
1.23 foxr 1230: my $event = Event->io(fd => $Socket,
1.5 foxr 1231: poll => 'w',
1232: cb => \&LondWritable,
1.8 foxr 1233: data => $Connection,
1.5 foxr 1234: desc => 'Connection to lond server');
1235: $ActiveConnections{$Connection} = $event;
1.52 foxr 1236: if ($ConnectionCount == 0) {
1237: &SetupTimer; # Need to handle timeouts with connections...
1238: }
1.5 foxr 1239: $ConnectionCount++;
1.8 foxr 1240: Debug(4, "Connection count = ".$ConnectionCount);
1.6 foxr 1241: if($ConnectionCount == 1) { # First Connection:
1242: QueueDelayed;
1243: }
1.9 foxr 1244: Log("SUCESS", "Created connection ".$ConnectionCount
1245: ." to host ".GetServerHost());
1.10 foxr 1246: return 1; # Return success.
1.1 foxr 1247: }
1248:
1249: }
1.3 albertel 1250:
1.1 foxr 1251: =pod
1.3 albertel 1252:
1.1 foxr 1253: =head2 StartRequest
1.3 albertel 1254:
1255: Starts a lond request going on a specified lond connection.
1256: parameters are:
1257:
1258: =item $Lond
1259:
1260: Connection to the lond that will send the transaction and receive the
1261: reply.
1262:
1263: =item $Client
1264:
1265: Connection to the client that is making this request We got the
1266: request from this socket, and when the request has been relayed to
1267: lond and we get a reply back from lond it will get sent to this
1268: socket.
1269:
1270: =item $Request
1271:
1272: The text of the request to send.
1273:
1.1 foxr 1274: =cut
1275:
1276: sub StartRequest {
1.47 foxr 1277:
1278: my ($Lond, $Request) = @_;
1.1 foxr 1279:
1.7 foxr 1280: Debug(6, "StartRequest: ".$Request->getRequest());
1.1 foxr 1281:
1282: my $Socket = $Lond->GetSocket();
1283:
1.7 foxr 1284: $Request->Activate($Lond);
1285: $ActiveTransactions{$Lond} = $Request;
1.1 foxr 1286:
1.7 foxr 1287: $Lond->InitiateTransaction($Request->getRequest());
1.23 foxr 1288: my $event = Event->io(fd => $Socket,
1.1 foxr 1289: poll => "w",
1290: cb => \&LondWritable,
1291: data => $Lond,
1292: desc => "lond transaction connection");
1293: $ActiveConnections{$Lond} = $event;
1294: Debug(8," Start Request made watcher data with ".$event->data."\n");
1295: }
1296:
1297: =pod
1.3 albertel 1298:
1.1 foxr 1299: =head2 QueueTransaction
1.3 albertel 1300:
1301: If there is an idle lond connection, it is put to work doing this
1302: transaction. Otherwise, the transaction is placed in the work queue.
1303: If placed in the work queue and the maximum number of connections has
1304: not yet been created, a new connection will be started. Our goal is
1305: to eventually have a sufficient number of connections that the work
1306: queue will typically be empty. parameters are:
1307:
1308: =item Socket
1309:
1310: open on the lonc client.
1311:
1312: =item Request
1313:
1314: data to send to the lond.
1.1 foxr 1315:
1316: =cut
1.3 albertel 1317:
1.1 foxr 1318: sub QueueTransaction {
1319:
1.7 foxr 1320: my $requestData = shift; # This is a LondTransaction.
1321: my $cmd = $requestData->getRequest();
1322:
1323: Debug(6,"QueueTransaction: ".$cmd);
1.1 foxr 1324:
1325: my $LondSocket = $IdleConnections->pop();
1326: if(!defined $LondSocket) { # Need to queue request.
1.29 foxr 1327: Debug(5,"Must queue...");
1.1 foxr 1328: $WorkQueue->enqueue($requestData);
1.56 foxr 1329: Debug(5, "Queue Transaction startnew $ConnectionCount $LondConnecting");
1330: if(($ConnectionCount < $MaxConnectionCount) && (! $LondConnecting)) {
1331:
1.22 foxr 1332: if($ConnectionRetriesLeft > 0) {
1.29 foxr 1333: Debug(5,"Starting additional lond connection");
1.56 foxr 1334: if(&MakeLondConnection() == 0) {
1.22 foxr 1335: EmptyQueue(); # Fail transactions, can't make connection.
1.42 foxr 1336: CloseAllLondConnections; # Should all be closed but...
1.22 foxr 1337: }
1338: } else {
1339: ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
1.56 foxr 1340: $LondConnecting = 0;
1.22 foxr 1341: EmptyQueue(); # It's worse than that ... he's dead Jim.
1.42 foxr 1342: CloseAllLondConnections; # Should all be closed but..
1.17 foxr 1343: }
1.1 foxr 1344: }
1345: } else { # Can start the request:
1346: Debug(8,"Can start...");
1.7 foxr 1347: StartRequest($LondSocket, $requestData);
1.1 foxr 1348: }
1349: }
1350:
1351: #-------------------------- Lonc UNIX socket handling ---------------------
1.3 albertel 1352:
1.1 foxr 1353: =pod
1.3 albertel 1354:
1.1 foxr 1355: =head2 ClientRequest
1.3 albertel 1356: Callback that is called when data can be read from the UNIX domain
1357: socket connecting us with an apache server process.
1.1 foxr 1358:
1359: =cut
1360:
1361: sub ClientRequest {
1362: Debug(6, "ClientRequest");
1363: my $event = shift;
1364: my $watcher = $event->w;
1365: my $socket = $watcher->fd;
1366: my $data = $watcher->data;
1367: my $thisread;
1368:
1369: Debug(9, " Watcher named: ".$watcher->desc);
1370:
1371: my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
1372: Debug(8, "rcv: data length = ".length($thisread)
1373: ." read =".$thisread);
1.29 foxr 1374: unless (defined $rv && length($thisread)) {
1.1 foxr 1375: # Likely eof on socket.
1376: Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
1377: close($socket);
1378: $watcher->cancel();
1379: delete($ActiveClients{$socket});
1.10 foxr 1380: return;
1.1 foxr 1381: }
1382: Debug(8,"Data: ".$data." this read: ".$thisread);
1383: $data = $data.$thisread; # Append new data.
1384: $watcher->data($data);
1.44 albertel 1385: if($data =~ /\n$/) { # Request entirely read.
1.87 albertel 1386: if ($data eq "close_connection_exit\n") {
1.9 foxr 1387: Log("CRITICAL",
1388: "Request Close Connection ... exiting");
1389: CloseAllLondConnections();
1390: exit;
1.87 albertel 1391: } elsif ($data eq "reset_retries\n") {
1392: Log("INFO", "Resetting Connection Retries.");
1393: $ConnectionRetriesLeft = $ConnectionRetries;
1394: &UpdateStatus();
1395: my $Transaction = LondTransaction->new($data);
1396: $Transaction->SetClient($socket);
1397: StartClientReply($Transaction, "ok\n");
1398: $watcher->cancel();
1399: return;
1.9 foxr 1400: }
1.1 foxr 1401: Debug(8, "Complete transaction received: ".$data);
1.87 albertel 1402: if ($LogTransactions) {
1.39 foxr 1403: Log("SUCCESS", "Transaction: '$data'"); # Transaction has \n.
1404: }
1.8 foxr 1405: my $Transaction = LondTransaction->new($data);
1.7 foxr 1406: $Transaction->SetClient($socket);
1407: QueueTransaction($Transaction);
1.1 foxr 1408: $watcher->cancel(); # Done looking for input data.
1409: }
1410:
1411: }
1412:
1.62 foxr 1413: #
1414: # Accept a connection request for a client (lonc child) and
1415: # start up an event watcher to keep an eye on input from that
1416: # Event. This can be called both from NewClient and from
1.80 albertel 1417: # ChildProcess.
1.62 foxr 1418: # Parameters:
1419: # $socket - The listener socket.
1420: # Returns:
1421: # NONE
1422: # Side Effects:
1423: # An event is made to watch the accepted connection.
1424: # Active clients hash is updated to reflect the new connection.
1425: # The client connection count is incremented.
1426: #
1427: sub accept_client {
1428: my ($socket) = @_;
1429:
1430: Debug(8, "Entering accept for lonc UNIX socket\n");
1431: my $connection = $socket->accept(); # Accept the client connection.
1432: Debug(8,"Connection request accepted from "
1433: .GetPeername($connection, AF_UNIX));
1434:
1435:
1436: my $description = sprintf("Connection to lonc client %d",
1437: $ClientConnection);
1438: Debug(9, "Creating event named: ".$description);
1439: Event->io(cb => \&ClientRequest,
1440: poll => 'r',
1441: desc => $description,
1442: data => "",
1443: fd => $connection);
1444: $ActiveClients{$connection} = $ClientConnection;
1445: $ClientConnection++;
1446: }
1.1 foxr 1447:
1448: =pod
1.3 albertel 1449:
1.1 foxr 1450: =head2 NewClient
1.3 albertel 1451:
1452: Callback that is called when a connection is received on the unix
1453: socket for a new client of lonc. The callback is parameterized by the
1454: event.. which is a-priori assumed to be an io event, and therefore has
1455: an fd member that is the Listener socket. We Accept the connection
1456: and register a new event on the readability of that socket:
1457:
1.1 foxr 1458: =cut
1.3 albertel 1459:
1.1 foxr 1460: sub NewClient {
1461: Debug(6, "NewClient");
1462: my $event = shift; # Get the event parameters.
1463: my $watcher = $event->w;
1464: my $socket = $watcher->fd; # Get the event' socket.
1465:
1.62 foxr 1466: &accept_client($socket);
1.1 foxr 1467: }
1.3 albertel 1468:
1469: =pod
1470:
1471: =head2 GetLoncSocketPath
1472:
1473: Returns the name of the UNIX socket on which to listen for client
1474: connections.
1.1 foxr 1475:
1.58 foxr 1476: =head2 Parameters:
1477:
1478: host (optional) - Name of the host socket to return.. defaults to
1479: the return from GetServerHost().
1480:
1.1 foxr 1481: =cut
1.3 albertel 1482:
1.1 foxr 1483: sub GetLoncSocketPath {
1.58 foxr 1484:
1485: my $host = GetServerHost(); # Default host.
1486: if (@_) {
1487: ($host) = @_; # Override if supplied.
1488: }
1489: return $UnixSocketDir."/".$host;
1.1 foxr 1490: }
1491:
1.3 albertel 1492: =pod
1493:
1494: =head2 GetServerHost
1495:
1496: Returns the host whose lond we talk with.
1497:
1.1 foxr 1498: =cut
1.3 albertel 1499:
1.7 foxr 1500: sub GetServerHost {
1.1 foxr 1501: return $RemoteHost; # Setup by the fork.
1502: }
1.3 albertel 1503:
1504: =pod
1505:
1.81 albertel 1506: =head2 GetServerId
1507:
1508: Returns the hostid whose lond we talk with.
1509:
1510: =cut
1511:
1512: sub GetHostId {
1513: return $RemoteHostId; # Setup by the fork.
1514: }
1515:
1516: =pod
1517:
1.3 albertel 1518: =head2 GetServerPort
1519:
1520: Returns the lond port number.
1521:
1.1 foxr 1522: =cut
1.3 albertel 1523:
1.7 foxr 1524: sub GetServerPort {
1.1 foxr 1525: return $perlvar{londPort};
1526: }
1.3 albertel 1527:
1528: =pod
1529:
1530: =head2 SetupLoncListener
1531:
1532: Setup a lonc listener event. The event is called when the socket
1533: becomes readable.. that corresponds to the receipt of a new
1534: connection. The event handler established will accept the connection
1535: (creating a communcations channel), that int turn will establish
1536: another event handler to subess requests.
1.1 foxr 1537:
1.58 foxr 1538: =head2 Parameters:
1539:
1540: host (optional) Name of the host to set up a unix socket to.
1541:
1.1 foxr 1542: =cut
1.3 albertel 1543:
1.1 foxr 1544: sub SetupLoncListener {
1.78 albertel 1545: my ($host,$SocketName) = @_;
1546: if (!$host) { $host = &GetServerHost(); }
1547: if (!$SocketName) { $SocketName = &GetLoncSocketPath($host); }
1.1 foxr 1548:
1.78 albertel 1549:
1550: unlink($SocketName);
1.58 foxr 1551:
1.1 foxr 1552: my $socket;
1.7 foxr 1553: unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,
1.55 albertel 1554: Listen => 250,
1.1 foxr 1555: Type => SOCK_STREAM)) {
1.64 foxr 1556: if($I_am_child) {
1557: &child_exit(-1, "Failed to create a lonc listener socket");
1558: } else {
1559: die "Failed to create a lonc listner socket";
1560: }
1.1 foxr 1561: }
1.59 foxr 1562: return $socket;
1.1 foxr 1563: }
1564:
1.39 foxr 1565: #
1566: # Toggle transaction logging.
1567: # Implicit inputs:
1568: # LogTransactions
1569: # Implicit Outputs:
1570: # LogTransactions
1571: sub ToggleTransactionLogging {
1572: print STDERR "Toggle transaction logging...\n";
1573: if(!$LogTransactions) {
1574: $LogTransactions = 1;
1575: } else {
1576: $LogTransactions = 0;
1577: }
1578:
1579:
1580: Log("SUCCESS", "Toggled transaction logging: $LogTransactions \n");
1581: }
1582:
1.14 foxr 1583: =pod
1584:
1585: =head2 ChildStatus
1586:
1587: Child USR1 signal handler to report the most recent status
1588: into the status file.
1589:
1.22 foxr 1590: We also use this to reset the retries count in order to allow the
1591: client to retry connections with a previously dead server.
1.69 matthew 1592:
1.14 foxr 1593: =cut
1.46 albertel 1594:
1.14 foxr 1595: sub ChildStatus {
1596: my $event = shift;
1597: my $watcher = $event->w;
1598:
1599: Debug(2, "Reporting child status because : ".$watcher->data);
1600: my $docdir = $perlvar{'lonDocRoot'};
1.67 albertel 1601:
1602: open(LOG,">>$docdir/lon-status/loncstatus.txt");
1603: flock(LOG,LOCK_EX);
1604: print LOG $$."\t".$RemoteHost."\t".$Status."\t".
1.14 foxr 1605: $RecentLogEntry."\n";
1.38 foxr 1606: #
1607: # Write out information about each of the connections:
1608: #
1.46 albertel 1609: if ($DebugLevel > 2) {
1.67 albertel 1610: print LOG "Active connection statuses: \n";
1.46 albertel 1611: my $i = 1;
1612: print STDERR "================================= Socket Status Dump:\n";
1613: foreach my $item (keys %ActiveConnections) {
1614: my $Socket = $ActiveConnections{$item}->data;
1615: my $state = $Socket->GetState();
1.67 albertel 1616: print LOG "Connection $i State: $state\n";
1.46 albertel 1617: print STDERR "---------------------- Connection $i \n";
1.48 foxr 1618: $Socket->Dump(-1); # Ensure it gets dumped..
1.46 albertel 1619: $i++;
1620: }
1.38 foxr 1621: }
1.67 albertel 1622: flock(LOG,LOCK_UN);
1623: close(LOG);
1.22 foxr 1624: $ConnectionRetriesLeft = $ConnectionRetries;
1.70 albertel 1625: UpdateStatus();
1.14 foxr 1626: }
1627:
1.1 foxr 1628: =pod
1.3 albertel 1629:
1.10 foxr 1630: =head2 SignalledToDeath
1631:
1632: Called in response to a signal that causes a chid process to die.
1633:
1634: =cut
1635:
1636:
1637: sub SignalledToDeath {
1.14 foxr 1638: my $event = shift;
1639: my $watcher= $event->w;
1640:
1641: Debug(2,"Signalled to death! via ".$watcher->data);
1.17 foxr 1642: my ($signal) = $watcher->data;
1.10 foxr 1643: chomp($signal);
1644: Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "
1645: ."died through "."\"$signal\"");
1.68 albertel 1646: #LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
1647: # ."\"$signal\"");
1.12 foxr 1648: exit 0;
1.10 foxr 1649:
1650: }
1.16 foxr 1651:
1.69 matthew 1652: =pod
1653:
1.16 foxr 1654: =head2 ToggleDebug
1655:
1656: This sub toggles trace debugging on and off.
1657:
1658: =cut
1659:
1660: sub ToggleDebug {
1661: my $Current = $DebugLevel;
1662: $DebugLevel = $NextDebugLevel;
1663: $NextDebugLevel = $Current;
1664:
1665: Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel");
1666:
1667: }
1668:
1.69 matthew 1669: =pod
1670:
1.1 foxr 1671: =head2 ChildProcess
1672:
1673: This sub implements a child process for a single lonc daemon.
1.61 foxr 1674: Optional parameter:
1675: $socket - if provided, this is a socket already open for listen
1676: on the client socket. Otherwise, a new listen is set up.
1.1 foxr 1677:
1678: =cut
1679:
1680: sub ChildProcess {
1.80 albertel 1681: # We've inherited all the
1.62 foxr 1682: # events of our parent and those have to be cancelled or else
1683: # all holy bloody chaos will result.. trust me, I already made
1684: # >that< mistake.
1685:
1686: my $host = GetServerHost();
1687: foreach my $listener (keys %parent_dispatchers) {
1688: my $watcher = $parent_dispatchers{$listener};
1689: my $s = $watcher->fd;
1690: if ($listener ne $host) { # Close everyone but me.
1691: Debug(5, "Closing listen socket for $listener");
1692: $s->close();
1693: }
1694: Debug(5, "Killing watcher for $listener");
1695:
1696: $watcher->cancel();
1.65 foxr 1697: delete($parent_dispatchers{$listener});
1.62 foxr 1698:
1699: }
1.65 foxr 1700:
1701: # kill off the parent's signal handlers too!
1702: #
1703:
1704: for my $handler (keys %parent_handlers) {
1705: my $watcher = $parent_handlers{$handler};
1706: $watcher->cancel();
1707: delete($parent_handlers{$handler});
1708: }
1709:
1.64 foxr 1710: $I_am_child = 1; # Seems like in spite of it all I may still getting
1711: # parent event dispatches.. flag I'm a child.
1.1 foxr 1712:
1713:
1.14 foxr 1714: #
1715: # Signals must be handled by the Event framework...
1.61 foxr 1716: #
1.14 foxr 1717:
1718: Event->signal(signal => "QUIT",
1719: cb => \&SignalledToDeath,
1720: data => "QUIT");
1721: Event->signal(signal => "HUP",
1722: cb => \&ChildStatus,
1723: data => "HUP");
1724: Event->signal(signal => "USR1",
1725: cb => \&ChildStatus,
1726: data => "USR1");
1.39 foxr 1727: Event->signal(signal => "USR2",
1728: cb => \&ToggleTransactionLogging);
1.16 foxr 1729: Event->signal(signal => "INT",
1730: cb => \&ToggleDebug,
1731: data => "INT");
1.1 foxr 1732:
1.62 foxr 1733: # Figure out if we got passed a socket or need to open one to listen for
1734: # client requests.
1735:
1.61 foxr 1736: my ($socket) = @_;
1737: if (!$socket) {
1738:
1739: $socket = SetupLoncListener();
1740: }
1.62 foxr 1741: # Establish an event to listen for client connection requests.
1742:
1743:
1.59 foxr 1744: Event->io(cb => \&NewClient,
1745: poll => 'r',
1746: desc => 'Lonc Listener Unix Socket',
1747: fd => $socket);
1.1 foxr 1748:
1.76 albertel 1749: $Event::DebugLevel = $DebugLevel;
1.1 foxr 1750:
1751: Debug(9, "Making initial lond connection for ".$RemoteHost);
1752:
1753: # Setup the initial server connection:
1754:
1.62 foxr 1755: # &MakeLondConnection(); // let first work request do it.
1.10 foxr 1756:
1.80 albertel 1757: # need to accept the connection since the event may not fire.
1.62 foxr 1758:
1.80 albertel 1759: &accept_client($socket);
1.5 foxr 1760:
1.1 foxr 1761: Debug(9,"Entering event loop");
1762: my $ret = Event::loop(); # Start the main event loop.
1763:
1764:
1.64 foxr 1765: &child_exit (-1,"Main event loop exited!!!");
1.1 foxr 1766: }
1767:
1768: # Create a new child for host passed in:
1769:
1770: sub CreateChild {
1.81 albertel 1771: my ($host, $hostid) = @_;
1.52 foxr 1772:
1.12 foxr 1773: my $sigset = POSIX::SigSet->new(SIGINT);
1774: sigprocmask(SIG_BLOCK, $sigset);
1.1 foxr 1775: $RemoteHost = $host;
1.9 foxr 1776: Log("CRITICAL", "Forking server for ".$host);
1.23 foxr 1777: my $pid = fork;
1.1 foxr 1778: if($pid) { # Parent
1.17 foxr 1779: $RemoteHost = "Parent";
1.83 albertel 1780: $ChildPid{$pid} = $host;
1.12 foxr 1781: sigprocmask(SIG_UNBLOCK, $sigset);
1.82 albertel 1782: undef(@all_host_ids);
1.1 foxr 1783: } else { # child.
1.81 albertel 1784: $RemoteHostId = $hostid;
1.5 foxr 1785: ShowStatus("Connected to ".$RemoteHost);
1.23 foxr 1786: $SIG{INT} = 'DEFAULT';
1.12 foxr 1787: sigprocmask(SIG_UNBLOCK, $sigset);
1.81 albertel 1788: &ChildProcess(); # Does not return.
1.1 foxr 1789: }
1.61 foxr 1790: }
1.1 foxr 1791:
1.61 foxr 1792: # parent_client_connection:
1793: # Event handler that processes client connections for the parent process.
1794: # This sub is called when the parent is listening on a socket and
1795: # a connection request arrives. We must:
1796: # Start a child process to accept the connection request.
1797: # Kill our listen on the socket.
1798: # Parameter:
1799: # event - The event object that was created to monitor this socket.
1800: # event->w->fd is the socket.
1801: # Returns:
1802: # NONE
1803: #
1804: sub parent_client_connection {
1.62 foxr 1805: if ($I_am_child) {
1806: # Should not get here, but seem to anyway:
1807: &Debug(5," Child caught parent client connection event!!");
1808: my ($event) = @_;
1809: my $watcher = $event->w;
1810: $watcher->cancel(); # Try to kill it off again!!
1811: } else {
1812: &Debug(9, "parent_client_connection");
1813: my ($event) = @_;
1814: my $watcher = $event->w;
1815: my $socket = $watcher->fd;
1.81 albertel 1816: my $connection = $socket->accept(); # Accept the client connection.
1817: Event->io(cb => \&get_remote_hostname,
1818: poll => 'r',
1819: data => "",
1820: fd => $connection);
1.77 albertel 1821: }
1822: }
1823:
1824: sub get_remote_hostname {
1.82 albertel 1825: my ($event) = @_;
1826: my $watcher = $event->w;
1827: my $socket = $watcher->fd;
1828:
1829: my $thisread;
1830: my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
1831: Debug(8, "rcv: data length = ".length($thisread)." read =".$thisread);
1832: if (!defined($rv) || length($thisread) == 0) {
1833: # Likely eof on socket.
1834: Debug(5,"Client Socket closed on lonc for p_c_c");
1835: close($socket);
1836: $watcher->cancel();
1837: return;
1838: }
1839:
1840: my $data = $watcher->data().$thisread;
1841: $watcher->data($data);
1842: if($data =~ /\n$/) { # Request entirely read.
1843: chomp($data);
1844: } else {
1845: return;
1846: }
1.77 albertel 1847:
1.82 albertel 1848: &Debug(5,"Creating child for $data (parent_client_connection)");
1849: (my $hostname,my $lonid,@all_host_ids) = split(':',$data);
1.83 albertel 1850: $ChildHost{$hostname}++;
1851: if ($ChildHost{$hostname} == 1) {
1852: &CreateChild($hostname,$lonid);
1853: } else {
1854: &Log('WARNING',"Request for a second child on $hostname");
1855: }
1.82 albertel 1856: # Clean up the listen since now the child takes over until it exits.
1857: $watcher->cancel(); # Nolonger listening to this event
1858: $socket->send("done\n");
1859: $socket->close();
1.61 foxr 1860: }
1861:
1862: # parent_listen:
1863: # Opens a socket and starts a listen for the parent process on a client UNIX
1864: # domain socket.
1865: #
1866: # This involves:
1867: # Creating a socket for listen.
1868: # Removing any socket lock file
1869: # Adding an event handler for this socket becoming readable
1870: # To the parent's event dispatcher.
1871: # Parameters:
1872: # loncapa_host - LonCAPA cluster name of the host represented by the client
1873: # socket.
1874: # Returns:
1875: # NONE
1876: #
1877: sub parent_listen {
1878: my ($loncapa_host) = @_;
1879: Debug(5, "parent_listen: $loncapa_host");
1880:
1.78 albertel 1881: my ($socket,$file);
1882: if (!$loncapa_host) {
1883: $loncapa_host = 'common_parent';
1884: $file = $perlvar{'lonSockCreate'};
1885: } else {
1886: $file = &GetLoncSocketPath($loncapa_host);
1887: }
1888: $socket = &SetupLoncListener($loncapa_host,$file);
1889:
1.62 foxr 1890: $listening_to{$socket} = $loncapa_host;
1.61 foxr 1891: if (!$socket) {
1892: die "Unable to create a listen socket for $loncapa_host";
1893: }
1894:
1.78 albertel 1895: my $lock_file = $file.".lock";
1.61 foxr 1896: unlink($lock_file); # No problem if it doesn't exist yet [startup e.g.]
1897:
1.77 albertel 1898: my $watcher =
1899: Event->io(cb => \&parent_client_connection,
1900: poll => 'r',
1901: desc => "Parent listener unix socket ($loncapa_host)",
1902: data => "",
1903: fd => $socket);
1.62 foxr 1904: $parent_dispatchers{$loncapa_host} = $watcher;
1.61 foxr 1905:
1906: }
1907:
1.77 albertel 1908: sub parent_clean_up {
1909: my ($loncapa_host) = @_;
1.87 albertel 1910: Debug(1, "parent_clean_up: $loncapa_host");
1.77 albertel 1911:
1912: my $socket_file = &GetLoncSocketPath($loncapa_host);
1913: unlink($socket_file); # No problem if it doesn't exist yet [startup e.g.]
1914: my $lock_file = $socket_file.".lock";
1915: unlink($lock_file); # No problem if it doesn't exist yet [startup e.g.]
1916: }
1917:
1.61 foxr 1918:
1.83 albertel 1919:
1920: # This sub initiates a listen on the common unix domain lonc client socket.
1921: # loncnew starts up with no children, and only spawns off children when a
1922: # connection request occurs on the common client unix socket. The spawned
1923: # child continues to run until it has been idle a while at which point it
1924: # eventually exits and once more the parent picks up the listen.
1.61 foxr 1925: #
1926: # Parameters:
1927: # NONE
1928: # Implicit Inputs:
1929: # The configuration file that has been read in by LondConnection.
1930: # Returns:
1931: # NONE
1932: #
1.77 albertel 1933: sub listen_on_common_socket {
1934: Debug(5, "listen_on_common_socket");
1.78 albertel 1935: &parent_listen();
1.77 albertel 1936: }
1937:
1.63 foxr 1938: # server_died is called whenever a child process exits.
1939: # Since this is dispatched via a signal, we must process all
1940: # dead children until there are no more left. The action
1941: # is to:
1942: # - Remove the child from the bookeeping hashes
1943: # - Re-establish a listen on the unix domain socket associated
1944: # with that host.
1945: # Parameters:
1946: # The event, but we don't actually care about it.
1947: sub server_died {
1948: &Debug(9, "server_died called...");
1949:
1950: while(1) { # Loop until waitpid nowait fails.
1951: my $pid = waitpid(-1, WNOHANG);
1952: if($pid <= 0) {
1953: return; # Nothing left to wait for.
1954: }
1955: # need the host to restart:
1956:
1.83 albertel 1957: my $host = $ChildPid{$pid};
1.63 foxr 1958: if($host) { # It's for real...
1959: &Debug(9, "Caught sigchild for $host");
1.83 albertel 1960: delete($ChildPid{$pid});
1961: delete($ChildHost{$host});
1.81 albertel 1962: &parent_clean_up($host);
1963:
1.63 foxr 1964: } else {
1965: &Debug(5, "Caught sigchild for pid not in hosts hash: $pid");
1966: }
1967: }
1968:
1969: }
1970:
1.1 foxr 1971: #
1972: # Parent process logic pass 1:
1973: # For each entry in the hosts table, we will
1974: # fork off an instance of ChildProcess to service the transactions
1975: # to that host. Each pid will be entered in a global hash
1976: # with the value of the key, the host.
1977: # The parent will then enter a loop to wait for process exits.
1978: # Each exit gets logged and the child gets restarted.
1979: #
1980:
1.5 foxr 1981: #
1982: # Fork and start in new session so hang-up isn't going to
1983: # happen without intent.
1984: #
1985:
1986:
1.6 foxr 1987:
1988:
1.8 foxr 1989:
1.6 foxr 1990:
1991: ShowStatus("Forming new session");
1992: my $childpid = fork;
1993: if ($childpid != 0) {
1994: sleep 4; # Give child a chacne to break to
1995: exit 0; # a new sesion.
1996: }
1.8 foxr 1997: #
1998: # Write my pid into the pid file so I can be located
1999: #
2000:
2001: ShowStatus("Parent writing pid file:");
1.23 foxr 2002: my $execdir = $perlvar{'lonDaemons'};
1.8 foxr 2003: open (PIDSAVE, ">$execdir/logs/lonc.pid");
2004: print PIDSAVE "$$\n";
2005: close(PIDSAVE);
1.6 foxr 2006:
1.17 foxr 2007:
2008:
1.6 foxr 2009: if (POSIX::setsid() < 0) {
2010: print "Could not create new session\n";
2011: exit -1;
2012: }
1.5 foxr 2013:
2014: ShowStatus("Forking node servers");
2015:
1.9 foxr 2016: Log("CRITICAL", "--------------- Starting children ---------------");
2017:
1.31 foxr 2018: LondConnection::ReadConfig; # Read standard config files.
1.1 foxr 2019:
1.80 albertel 2020: $RemoteHost = "[parent]";
1.81 albertel 2021: &listen_on_common_socket();
1.60 foxr 2022:
1.12 foxr 2023: $RemoteHost = "Parent Server";
1.1 foxr 2024:
2025: # Maintain the population:
1.5 foxr 2026:
2027: ShowStatus("Parent keeping the flock");
1.1 foxr 2028:
1.12 foxr 2029:
1.80 albertel 2030: # We need to setup a SIGChild event to handle the exit (natural or otherwise)
2031: # of the children.
1.61 foxr 2032:
1.80 albertel 2033: Event->signal(cb => \&server_died,
2034: desc => "Child exit handler",
2035: signal => "CHLD");
2036:
2037:
2038: # Set up all the other signals we set up.
2039:
2040: $parent_handlers{INT} = Event->signal(cb => \&Terminate,
2041: desc => "Parent INT handler",
2042: signal => "INT");
2043: $parent_handlers{TERM} = Event->signal(cb => \&Terminate,
2044: desc => "Parent TERM handler",
2045: signal => "TERM");
1.81 albertel 2046: $parent_handlers{HUP} = Event->signal(cb => \&KillThemAll,
2047: desc => "Parent HUP handler.",
2048: signal => "HUP");
1.80 albertel 2049: $parent_handlers{USR1} = Event->signal(cb => \&CheckKids,
2050: desc => "Parent USR1 handler",
2051: signal => "USR1");
2052: $parent_handlers{USR2} = Event->signal(cb => \&UpdateKids,
2053: desc => "Parent USR2 handler.",
2054: signal => "USR2");
2055:
2056: # Start procdesing events.
2057:
2058: $Event::DebugLevel = $DebugLevel;
2059: Debug(9, "Parent entering event loop");
2060: my $ret = Event::loop();
2061: die "Main Event loop exited: $ret";
1.14 foxr 2062:
2063: =pod
2064:
2065: =head1 CheckKids
2066:
2067: Since kids do not die as easily in this implementation
2068: as the previous one, there is no need to restart the
2069: dead ones (all dead kids get restarted when they die!!)
2070: The only thing this function does is to pass USR1 to the
2071: kids so that they report their status.
2072:
2073: =cut
2074:
2075: sub CheckKids {
2076: Debug(2, "Checking status of children");
2077: my $docdir = $perlvar{'lonDocRoot'};
2078: my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt");
2079: my $now=time;
2080: my $local=localtime($now);
2081: print $fh "LONC status $local - parent $$ \n\n";
1.65 foxr 2082: foreach my $host (keys %parent_dispatchers) {
2083: print $fh "LONC Parent process listening for $host\n";
2084: }
1.83 albertel 2085: foreach my $pid (keys %ChildPid) {
1.14 foxr 2086: Debug(2, "Sending USR1 -> $pid");
2087: kill 'USR1' => $pid; # Tell Child to report status.
2088: }
1.65 foxr 2089:
1.14 foxr 2090: }
1.24 foxr 2091:
2092: =pod
2093:
2094: =head1 UpdateKids
2095:
1.25 foxr 2096: parent's SIGUSR2 handler. This handler:
1.24 foxr 2097:
2098: =item
2099:
2100: Rereads the hosts file.
2101:
2102: =item
2103:
2104: Kills off (via sigint) children for hosts that have disappeared.
2105:
2106: =item
2107:
1.27 foxr 2108: QUITs children for hosts that already exist (this just forces a status display
1.24 foxr 2109: and resets the connection retry count for that host.
2110:
2111: =item
2112:
2113: Starts new children for hosts that have been added to the hosts.tab file since
2114: the start of the master program and maintains them.
2115:
2116: =cut
2117:
2118: sub UpdateKids {
1.27 foxr 2119:
1.25 foxr 2120: Log("INFO", "Updating connections via SIGUSR2");
1.27 foxr 2121:
1.65 foxr 2122: # I'm not sure what I was thinking in the first implementation.
2123: # someone will have to work hard to convince me the effect is any
2124: # different than Restart, especially now that we don't start up
2125: # per host servers automatically, may as well just restart.
2126: # The down side is transactions that are in flight will get timed out
2127: # (lost unless they are critical).
1.27 foxr 2128:
1.81 albertel 2129: &KillThemAll();
1.24 foxr 2130: }
2131:
1.14 foxr 2132:
1.13 foxr 2133: =pod
2134:
2135: =head1 Restart
2136:
2137: Signal handler for HUP... all children are killed and
2138: we self restart. This is an el-cheapo way to re read
2139: the config file.
2140:
2141: =cut
2142:
2143: sub Restart {
1.23 foxr 2144: &KillThemAll; # First kill all the children.
1.13 foxr 2145: Log("CRITICAL", "Restarting");
2146: my $execdir = $perlvar{'lonDaemons'};
2147: unlink("$execdir/logs/lonc.pid");
1.65 foxr 2148: exec("$executable");
1.10 foxr 2149: }
1.12 foxr 2150:
2151: =pod
2152:
2153: =head1 KillThemAll
2154:
2155: Signal handler that kills all children by sending them a
1.17 foxr 2156: SIGHUP. Responds to sigint and sigterm.
1.12 foxr 2157:
2158: =cut
2159:
1.10 foxr 2160: sub KillThemAll {
1.12 foxr 2161: Debug(2, "Kill them all!!");
1.85 albertel 2162:
2163: #local($SIG{CHLD}) = 'IGNORE';
2164: # Our children >will< die.
2165: # but we need to catch their death and cleanup after them in case this is
2166: # a restart set of kills
2167: my @allpids = keys(%ChildPid);
2168: foreach my $pid (@allpids) {
1.83 albertel 2169: my $serving = $ChildPid{$pid};
1.52 foxr 2170: ShowStatus("Nicely Killing lonc for $serving pid = $pid");
2171: Log("CRITICAL", "Nicely Killing lonc for $serving pid = $pid");
1.17 foxr 2172: kill 'QUIT' => $pid;
1.12 foxr 2173: }
1.85 albertel 2174: ShowStatus("Finished killing child processes off.");
1.1 foxr 2175: }
1.12 foxr 2176:
1.52 foxr 2177:
2178: #
2179: # Kill all children via KILL. Just in case the
2180: # first shot didn't get them.
2181:
2182: sub really_kill_them_all_dammit
2183: {
2184: Debug(2, "Kill them all Dammit");
2185: local($SIG{CHLD} = 'IGNORE'); # In case some purist reenabled them.
1.83 albertel 2186: foreach my $pid (keys %ChildPid) {
2187: my $serving = $ChildPid{$pid};
1.52 foxr 2188: &ShowStatus("Nastily killing lonc for $serving pid = $pid");
2189: Log("CRITICAL", "Nastily killing lonc for $serving pid = $pid");
2190: kill 'KILL' => $pid;
1.83 albertel 2191: delete($ChildPid{$pid});
1.52 foxr 2192: my $execdir = $perlvar{'lonDaemons'};
2193: unlink("$execdir/logs/lonc.pid");
2194: }
2195: }
1.69 matthew 2196:
1.14 foxr 2197: =pod
2198:
2199: =head1 Terminate
2200:
2201: Terminate the system.
2202:
2203: =cut
2204:
2205: sub Terminate {
1.52 foxr 2206: &Log("CRITICAL", "Asked to kill children.. first be nice...");
2207: &KillThemAll;
2208: #
2209: # By now they really should all be dead.. but just in case
2210: # send them all SIGKILL's after a bit of waiting:
2211:
2212: sleep(4);
2213: &Log("CRITICAL", "Now kill children nasty");
2214: &really_kill_them_all_dammit;
1.17 foxr 2215: Log("CRITICAL","Master process exiting");
2216: exit 0;
1.14 foxr 2217:
2218: }
1.81 albertel 2219:
2220: sub my_hostname {
2221: use Sys::Hostname;
2222: my $name = &hostname();
2223: &Debug(9,"Name is $name");
2224: return $name;
2225: }
2226:
1.12 foxr 2227: =pod
1.1 foxr 2228:
2229: =head1 Theory
1.3 albertel 2230:
2231: The event class is used to build this as a single process with an
2232: event driven model. The following events are handled:
1.1 foxr 2233:
2234: =item UNIX Socket connection Received
2235:
2236: =item Request data arrives on UNIX data transfer socket.
2237:
2238: =item lond connection becomes writable.
2239:
2240: =item timer fires at 1 second intervals.
2241:
2242: All sockets are run in non-blocking mode. Timeouts managed by the timer
2243: handler prevents hung connections.
2244:
2245: Key data structures:
2246:
1.3 albertel 2247: =item RequestQueue
2248:
2249: A queue of requests received from UNIX sockets that are
2250: waiting for a chance to be forwarded on a lond connection socket.
2251:
2252: =item ActiveConnections
2253:
2254: A hash of lond connections that have transactions in process that are
2255: available to be timed out.
2256:
2257: =item ActiveTransactions
2258:
2259: A hash indexed by lond connections that contain the client reply
2260: socket for each connection that has an active transaction on it.
2261:
2262: =item IdleConnections
2263:
2264: A hash of lond connections that have no work to do. These connections
2265: can be closed if they are idle for a long enough time.
1.1 foxr 2266:
2267: =cut
1.88 ! foxr 2268:
! 2269: =pod
! 2270:
! 2271: =head1 Log messages
! 2272:
! 2273: The following is a list of log messages that can appear in the
! 2274: lonc.log file. Each log file has a severity and a message.
! 2275:
! 2276: =over 2
! 2277:
! 2278: =item Warning A socket timeout was detected
! 2279:
! 2280: If there are pending transactions in the socket's queue,
! 2281: they are failed (saved if critical). If the connection
! 2282: retry count gets exceeded by this, the
! 2283: remote host is marked as dead.
! 2284: Called when timeouts occured during the connection and
! 2285: connection dialog with a remote host.
! 2286:
! 2287: =item Critical Host makred DEAD <hostname>
! 2288:
! 2289: The numer of retry counts for contacting a host was
! 2290: exceeded. The host is marked dead an no
! 2291: further attempts will be made by that child.
! 2292:
! 2293: =item Info lonc pipe client hung up on us
! 2294:
! 2295: Write to the client pipe indicated no data transferred
! 2296: Socket to remote host is shut down. Reply to the client
! 2297: is discarded. Note: This is commented out in &ClientWriteable
! 2298:
! 2299: =item Success Reply from lond: <data>
! 2300:
! 2301: Can be enabled for debugging by setting LogTransactions to nonzero.
! 2302: Indicates a successful transaction with lond, <data> is the data received
! 2303: from the remote lond.
! 2304:
! 2305: =item Success A delayed transaction was completed
! 2306:
! 2307: A transaction that must be reliable was executed and completed
! 2308: as lonc restarted. This is followed by a mesage of the form
! 2309:
! 2310: S: client-name : request
! 2311:
! 2312: =item WARNING Failing transaction <cmd>:<subcmd>
! 2313:
! 2314: Transaction failed on a socket, but the failure retry count for the remote
! 2315: node has not yet been exhausted (the node is not yet marked dead).
! 2316: cmd is the command, subcmd is the subcommand. This results from a con_lost
! 2317: when communicating with lond.
! 2318:
! 2319: =item WARNING Shutting down a socket
! 2320:
! 2321: Called when a socket is being closed to lond. This is emitted both when
! 2322: idle pruning is being done and when the socket has been disconnected by the remote.
! 2323:
! 2324: =item WARNING Lond connection lost.
! 2325:
! 2326: Called when a read from lond's socket failed indicating lond has closed the
! 2327: connection or died. This should be followed by one or more
! 2328:
! 2329: "WARNING Failing transaction..." msgs for each in-flight or queued transaction.
! 2330:
! 2331: =item INFO Connected to lond version: <version>
! 2332:
! 2333: When connection negotiation is complete, the lond version is requested and logged here.
! 2334:
! 2335: =item SUCCESS Connection n to host now ready for action
! 2336:
! 2337: Emitted when connection has been completed with lond. n is then number of
! 2338: concurrent connections and host, the host to which the connection has just
! 2339: been established.
! 2340:
! 2341: =item WARNING Connection to host has been disconnected
! 2342:
! 2343: Write to a lond resulted in failure status. Connection to lond is dropped.
! 2344:
! 2345: =item SUCCESS Created connection n to host host
! 2346:
! 2347: Initial connection request to host..(before negotiation).
! 2348:
! 2349: =item CRITICAL Request Close Connection ... exiting
! 2350:
! 2351: Client has sent "close_connection_exit" The loncnew server is exiting.
! 2352:
! 2353: =item INFO Resetting Connection Retries
! 2354:
! 2355: Client has sent "reset_retries" The lond connection retries are reset to zero for the
! 2356: corresponding lond.
! 2357:
! 2358: =item SUCCESS Transaction <data>
! 2359:
! 2360: Only emitted if the global variable $LogTransactions was set to true.
! 2361: A client has requested a lond transaction <data> is the contents of the request.
! 2362:
! 2363: =item SUCCESS Toggled transaction logging <LogTransactions>
! 2364:
! 2365: The state of the $LogTransactions global has been toggled, and its current value
! 2366: (after being toggled) is displayed. When non zero additional logging of transactions
! 2367: is enabled for debugging purposes. Transaction logging is toggled on receipt of a USR2
! 2368: signal.
! 2369:
! 2370: =item CRITICAL Abnormal exit. Child <pid> for <host> died thorugh signal.
! 2371:
! 2372: QUIT signal received. lonc child process is exiting.
! 2373:
! 2374: =item SUCCESS New debugging level for <RemoteHost> now <DebugLevel>
! 2375:
! 2376: Debugging toggled for the host loncnew is talking with.
! 2377: Currently debugging is a level based scheme with higher number
! 2378: conveying more information. The daemon starts out at
! 2379: DebugLevel 0 and can toggle back and forth between that and
! 2380: DebugLevel 2 These are controlled by
! 2381: the global variables $DebugLevel and $NextDebugLevel
! 2382: The debug level can go up to 9.
! 2383: SIGINT toggles the debug level. The higher the debug level the
! 2384: more debugging information is spewed. See the Debug
! 2385: sub in loncnew.
! 2386:
! 2387: =item CRITICAL Forking server for host
! 2388:
! 2389: A child is being created to service requests for the specified host.
! 2390:
! 2391:
! 2392: =item WARNING Request for a second child on hostname
! 2393:
! 2394: Somehow loncnew was asked to start a second child on a host that already had a child
! 2395: servicing it. This request is not honored, but themessage is emitted. This could happen
! 2396: due to a race condition. When a client attempts to contact loncnew for a new host, a child
! 2397: is forked off to handle the requests for that server. The parent then backs off the Unix
! 2398: domain socket leaving it for the child to service all requests. If in the time between
! 2399: creating the child, and backing off, a new connection request comes in to the unix domain
! 2400: socket, this could trigger (unlikely but remotely possible),.
! 2401:
! 2402: =item CRITICAL ------ Starting Children ----
! 2403:
! 2404: This message should probably be changed to "Entering event loop" as the loncnew only starts
! 2405: children as needed. This message is emitted as new events are established and
! 2406: the event processing loop is entered.
! 2407:
! 2408: =item INFO Updating connections via SIGUSR2
! 2409:
! 2410: SIGUSR2 received. The original code would kill all clients, re-read the host file,
! 2411: then restart children for each host. Now that childrean aree started on demand, this
! 2412: just kills all child processes and lets requests start them as needed again.
! 2413:
! 2414:
! 2415: =item CRITICAL Restarting
! 2416:
! 2417: SigHUP received. all the children are killed and the script exec's itself to start again.
! 2418:
! 2419: =item CRITICAL Nicely killing lonc for host pid = <pid>
! 2420:
! 2421: Attempting to kill the child that is serving the specified host (pid given) cleanly via
! 2422: SIGQUIT The child should handle that, clean up nicely and exit.
! 2423:
! 2424: =item CRITICAL Nastily killing lonc for host pid = <pid>
! 2425:
! 2426: The child specified did not die when requested via SIGQUIT. Therefore it is killed
! 2427: via SIGKILL.
! 2428:
! 2429: =item CRITICAL Asked to kill children.. first be nice..
! 2430:
! 2431: In the parent's INT handler. INT kills the child processes. This inidicate loncnew
! 2432: is about to attempt to kill all known children via SIGQUIT. This message should be followed
! 2433: by one "Nicely killing" message for each extant child.
! 2434:
! 2435: =item CRITICAL Now kill children nasty
! 2436:
! 2437: In the parent's INT handler. remaining children are about to be killed via
! 2438: SIGKILL. Should be followed by a Nastily killing... for each lonc child that
! 2439: refused to die.
! 2440:
! 2441: =item CRITICAL Master process exiting
! 2442:
! 2443: In the parent's INT handler. just prior to the exit 0 call.
! 2444:
! 2445: =back
! 2446:
! 2447: =cut
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