Annotation of loncom/loncnew, revision 1.39
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: #
1.39 ! foxr 5: # $Id: loncnew,v 1.38 2004/01/05 09:29:36 foxr 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;
63: use LONCAPA::HashIterator;
64:
65:
66: #
67: # Disable all signals we might receive from outside for now.
68: #
69:
70:
71: # Read the httpd configuration file to get perl variables
72: # normally set in apache modules:
73:
74: my $perlvarref = LONCAPA::Configuration::read_conf('loncapa.conf');
75: my %perlvar = %{$perlvarref};
76:
77: #
78: # parent and shared variables.
79:
80: my %ChildHash; # by pid -> host.
1.26 foxr 81: my %HostToPid; # By host -> pid.
82: my %HostHash; # by loncapaname -> IP.
1.1 foxr 83:
84:
1.9 foxr 85: my $MaxConnectionCount = 10; # Will get from config later.
1.1 foxr 86: my $ClientConnection = 0; # Uniquifier for client events.
87:
1.9 foxr 88: my $DebugLevel = 0;
1.29 foxr 89: my $NextDebugLevel= 2; # So Sigint can toggle this.
1.1 foxr 90: my $IdleTimeout= 3600; # Wait an hour before pruning connections.
91:
1.39 ! foxr 92: my $LogTransactions = 0; # When True, all transactions/replies get logged.
! 93:
1.1 foxr 94: #
95: # The variables below are only used by the child processes.
96: #
97: my $RemoteHost; # Name of host child is talking to.
1.20 albertel 98: my $UnixSocketDir= $perlvar{'lonSockDir'};
1.1 foxr 99: my $IdleConnections = Stack->new(); # Set of idle connections
100: my %ActiveConnections; # Connections to the remote lond.
1.7 foxr 101: my %ActiveTransactions; # LondTransactions in flight.
1.1 foxr 102: my %ActiveClients; # Serial numbers of active clients by socket.
103: my $WorkQueue = Queue->new(); # Queue of pending transactions.
104: my $ConnectionCount = 0;
1.4 foxr 105: my $IdleSeconds = 0; # Number of seconds idle.
1.9 foxr 106: my $Status = ""; # Current status string.
1.14 foxr 107: my $RecentLogEntry = "";
1.30 foxr 108: my $ConnectionRetries=2; # Number of connection retries allowed.
109: my $ConnectionRetriesLeft=2; # Number of connection retries remaining.
1.1 foxr 110:
111: #
1.9 foxr 112: # The hash below gives the HTML format for log messages
113: # given a severity.
114: #
115: my %LogFormats;
116:
117: $LogFormats{"CRITICAL"} = "<font color=red>CRITICAL: %s</font>";
118: $LogFormats{"SUCCESS"} = "<font color=green>SUCCESS: %s</font>";
119: $LogFormats{"INFO"} = "<font color=yellow>INFO: %s</font>";
120: $LogFormats{"WARNING"} = "<font color=blue>WARNING: %s</font>";
121: $LogFormats{"DEFAULT"} = " %s ";
122:
1.10 foxr 123:
124:
125: =pod
126:
127: =head2 LogPerm
128:
129: Makes an entry into the permanent log file.
130:
131: =cut
132: sub LogPerm {
133: my $message=shift;
134: my $execdir=$perlvar{'lonDaemons'};
135: my $now=time;
136: my $local=localtime($now);
137: my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
138: print $fh "$now:$message:$local\n";
139: }
1.9 foxr 140:
141: =pod
142:
143: =head2 Log
144:
145: Logs a message to the log file.
146: Parameters:
147:
148: =item severity
149:
150: One of CRITICAL, WARNING, INFO, SUCCESS used to select the
151: format string used to format the message. if the severity is
152: not a defined severity the Default format string is used.
153:
154: =item message
155:
156: The base message. In addtion to the format string, the message
157: will be appended to a string containing the name of our remote
158: host and the time will be formatted into the message.
159:
160: =cut
161:
162: sub Log {
163: my $severity = shift;
164: my $message = shift;
165:
166: if(!$LogFormats{$severity}) {
167: $severity = "DEFAULT";
168: }
169:
170: my $format = $LogFormats{$severity};
171:
172: # Put the window dressing in in front of the message format:
173:
174: my $now = time;
175: my $local = localtime($now);
176: my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
177: my $finalformat = $finalformat.$format."\n";
178:
179: # open the file and put the result.
180:
181: my $execdir = $perlvar{'lonDaemons'};
182: my $fh = IO::File->new(">>$execdir/logs/lonc.log");
183: my $msg = sprintf($finalformat, $message);
1.14 foxr 184: $RecentLogEntry = $msg;
1.9 foxr 185: print $fh $msg;
186:
1.10 foxr 187:
1.9 foxr 188: }
1.6 foxr 189:
1.3 albertel 190:
1.1 foxr 191: =pod
1.3 albertel 192:
193: =head2 GetPeerName
194:
195: Returns the name of the host that a socket object is connected to.
196:
1.1 foxr 197: =cut
198:
199: sub GetPeername {
200: my $connection = shift;
201: my $AdrFamily = shift;
202: my $peer = $connection->peername();
203: my $peerport;
204: my $peerip;
205: if($AdrFamily == AF_INET) {
206: ($peerport, $peerip) = sockaddr_in($peer);
1.23 foxr 207: my $peername = gethostbyaddr($peerip, $AdrFamily);
1.1 foxr 208: return $peername;
209: } elsif ($AdrFamily == AF_UNIX) {
210: my $peerfile;
211: ($peerfile) = sockaddr_un($peer);
212: return $peerfile;
213: }
214: }
215: =pod
1.3 albertel 216:
1.1 foxr 217: =head2 Debug
1.3 albertel 218:
219: Invoked to issue a debug message.
220:
1.1 foxr 221: =cut
1.3 albertel 222:
1.1 foxr 223: sub Debug {
224: my $level = shift;
225: my $message = shift;
226: if ($level <= $DebugLevel) {
1.23 foxr 227: Log("INFO", "-Debug- $message host = $RemoteHost");
1.1 foxr 228: }
229: }
230:
231: sub SocketDump {
232: my $level = shift;
233: my $socket= shift;
234: if($level <= $DebugLevel) {
235: $socket->Dump();
236: }
237: }
1.3 albertel 238:
1.1 foxr 239: =pod
1.3 albertel 240:
1.5 foxr 241: =head2 ShowStatus
242:
243: Place some text as our pid status.
1.10 foxr 244: and as what we return in a SIGUSR1
1.5 foxr 245:
246: =cut
247: sub ShowStatus {
1.10 foxr 248: my $state = shift;
249: my $now = time;
250: my $local = localtime($now);
251: $Status = $local.": ".$state;
252: $0='lonc: '.$state.' '.$local;
1.5 foxr 253: }
254:
255: =pod
256:
1.15 foxr 257: =head 2 SocketTimeout
258:
259: Called when an action on the socket times out. The socket is
260: destroyed and any active transaction is failed.
261:
262:
263: =cut
264: sub SocketTimeout {
265: my $Socket = shift;
1.38 foxr 266: Log("WARNING", "A socket timeout was detected");
267: Debug(0, " SocketTimeout called: ");
268: $Socket->Dump();
1.22 foxr 269: KillSocket($Socket); # A transaction timeout also counts as
270: # a connection failure:
271: $ConnectionRetriesLeft--;
1.15 foxr 272: }
1.35 foxr 273: #----------------------------- Timer management ------------------------
1.15 foxr 274:
275: =pod
276:
1.1 foxr 277: =head2 Tick
1.3 albertel 278:
279: Invoked each timer tick.
280:
1.1 foxr 281: =cut
282:
1.5 foxr 283:
1.1 foxr 284: sub Tick {
285: my $client;
1.22 foxr 286: if($ConnectionRetriesLeft > 0) {
287: ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
288: ." Retries remaining: ".$ConnectionRetriesLeft);
289: } else {
290: ShowStatus(GetServerHost()." >> DEAD <<");
291: }
1.4 foxr 292: # Is it time to prune connection count:
293:
294:
295: if($IdleConnections->Count() &&
296: ($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
297: $IdleSeconds++;
298: if($IdleSeconds > $IdleTimeout) { # Prune a connection...
1.23 foxr 299: my $Socket = $IdleConnections->pop();
1.6 foxr 300: KillSocket($Socket);
1.4 foxr 301: }
302: } else {
303: $IdleSeconds = 0; # Reset idle count if not idle.
304: }
1.15 foxr 305: #
306: # For each inflight transaction, tick down its timeout counter.
307: #
1.35 foxr 308:
1.34 albertel 309: foreach my $item (keys %ActiveConnections) {
310: my $State = $ActiveConnections{$item}->data->GetState();
1.35 foxr 311: if ($State ne 'Idle') {
1.34 albertel 312: Debug(5,"Ticking Socket $State $item");
313: $ActiveConnections{$item}->data->Tick();
314: }
1.15 foxr 315: }
1.5 foxr 316: # Do we have work in the queue, but no connections to service them?
317: # If so, try to make some new connections to get things going again.
318: #
319:
320: my $Requests = $WorkQueue->Count();
1.10 foxr 321: if (($ConnectionCount == 0) && ($Requests > 0)) {
322: if ($ConnectionRetriesLeft > 0) {
323: my $Connections = ($Requests <= $MaxConnectionCount) ?
324: $Requests : $MaxConnectionCount;
1.29 foxr 325: Debug(5,"Work but no connections, start ".$Connections." of them");
1.22 foxr 326: my $successCount = 0;
1.23 foxr 327: for (my $i =0; $i < $Connections; $i++) {
1.22 foxr 328: $successCount += MakeLondConnection();
329: }
330: if($successCount == 0) { # All connections failed:
1.29 foxr 331: Debug(5,"Work in queue failed to make any connectiouns\n");
1.22 foxr 332: EmptyQueue(); # Fail pending transactions with con_lost.
1.10 foxr 333: }
334: } else {
1.22 foxr 335: ShowStatus(GetServerHost()." >>> DEAD!!! <<<");
1.29 foxr 336: Debug(5,"Work in queue, but gave up on connections..flushing\n");
1.10 foxr 337: EmptyQueue(); # Connections can't be established.
1.5 foxr 338: }
339:
340: }
1.1 foxr 341: }
342:
343: =pod
1.3 albertel 344:
1.1 foxr 345: =head2 SetupTimer
346:
1.3 albertel 347: Sets up a 1 per sec recurring timer event. The event handler is used to:
1.1 foxr 348:
1.3 albertel 349: =item
350:
351: Trigger timeouts on communications along active sockets.
352:
353: =item
354:
355: Trigger disconnections of idle sockets.
1.1 foxr 356:
357: =cut
358:
359: sub SetupTimer {
360: Debug(6, "SetupTimer");
1.33 foxr 361: Event->timer(interval => 1, cb => \&Tick );
1.1 foxr 362: }
1.3 albertel 363:
1.1 foxr 364: =pod
1.3 albertel 365:
1.1 foxr 366: =head2 ServerToIdle
1.3 albertel 367:
368: This function is called when a connection to the server is
369: ready for more work.
370:
371: If there is work in the Work queue the top element is dequeued
1.1 foxr 372: and the connection will start to work on it. If the work queue is
373: empty, the connection is pushed on the idle connection stack where
374: it will either get another work unit, or alternatively, if it sits there
375: long enough, it will be shut down and released.
376:
1.3 albertel 377: =cut
1.1 foxr 378:
379: sub ServerToIdle {
380: my $Socket = shift; # Get the socket.
1.7 foxr 381: delete($ActiveTransactions{$Socket}); # Server has no transaction
1.1 foxr 382:
1.29 foxr 383: &Debug(5, "Server to idle");
1.1 foxr 384:
385: # If there's work to do, start the transaction:
386:
1.23 foxr 387: my $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
1.29 foxr 388: if ($reqdata ne undef) {
389: Debug(5, "Queue gave request data: ".$reqdata->getRequest());
1.7 foxr 390: &StartRequest($Socket, $reqdata);
1.8 foxr 391:
1.1 foxr 392: } else {
393:
394: # There's no work waiting, so push the server to idle list.
1.29 foxr 395: &Debug(5, "No new work requests, server connection going idle");
1.1 foxr 396: $IdleConnections->push($Socket);
397: }
398: }
1.3 albertel 399:
1.1 foxr 400: =pod
1.3 albertel 401:
1.1 foxr 402: =head2 ClientWritable
1.3 albertel 403:
404: Event callback for when a client socket is writable.
405:
406: This callback is established when a transaction reponse is
407: avaiable from lond. The response is forwarded to the unix socket
408: as it becomes writable in this sub.
409:
1.1 foxr 410: Parameters:
411:
1.3 albertel 412: =item Event
413:
414: The event that has been triggered. Event->w->data is
415: the data and Event->w->fd is the socket to write.
1.1 foxr 416:
417: =cut
1.3 albertel 418:
1.1 foxr 419: sub ClientWritable {
420: my $Event = shift;
421: my $Watcher = $Event->w;
422: my $Data = $Watcher->data;
423: my $Socket = $Watcher->fd;
424:
425: # Try to send the data:
426:
427: &Debug(6, "ClientWritable writing".$Data);
428: &Debug(9, "Socket is: ".$Socket);
429:
1.6 foxr 430: if($Socket->connected) {
431: my $result = $Socket->send($Data, 0);
432:
433: # $result undefined: the write failed.
434: # otherwise $result is the number of bytes written.
435: # Remove that preceding string from the data.
436: # If the resulting data is empty, destroy the watcher
437: # and set up a read event handler to accept the next
438: # request.
439:
440: &Debug(9,"Send result is ".$result." Defined: ".defined($result));
1.29 foxr 441: if($result ne undef) {
1.6 foxr 442: &Debug(9, "send result was defined");
443: if($result == length($Data)) { # Entire string sent.
444: &Debug(9, "ClientWritable data all written");
445: $Watcher->cancel();
446: #
447: # Set up to read next request from socket:
448:
449: my $descr = sprintf("Connection to lonc client %d",
450: $ActiveClients{$Socket});
451: Event->io(cb => \&ClientRequest,
452: poll => 'r',
453: desc => $descr,
454: data => "",
455: fd => $Socket);
456:
457: } else { # Partial string sent.
458: $Watcher->data(substr($Data, $result));
1.15 foxr 459: if($result == 0) { # client hung up on us!!
460: Log("INFO", "lonc pipe client hung up on us!");
461: $Watcher->cancel;
462: $Socket->shutdown(2);
463: $Socket->close();
464: }
1.6 foxr 465: }
466:
467: } else { # Error of some sort...
468:
469: # Some errnos are possible:
470: my $errno = $!;
471: if($errno == POSIX::EWOULDBLOCK ||
472: $errno == POSIX::EAGAIN ||
473: $errno == POSIX::EINTR) {
474: # No action taken?
475: } else { # Unanticipated errno.
476: &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
477: $Watcher->cancel; # Stop the watcher.
478: $Socket->shutdown(2); # Kill connection
479: $Socket->close(); # Close the socket.
480: }
1.1 foxr 481:
482: }
1.6 foxr 483: } else {
484: $Watcher->cancel(); # A delayed request...just cancel.
1.1 foxr 485: }
486: }
487:
488: =pod
1.3 albertel 489:
1.1 foxr 490: =head2 CompleteTransaction
1.3 albertel 491:
492: Called when the reply data has been received for a lond
1.1 foxr 493: transaction. The reply data must now be sent to the
494: ultimate client on the other end of the Unix socket. This is
495: done by setting up a writable event for the socket with the
496: data the reply data.
1.3 albertel 497:
1.1 foxr 498: Parameters:
1.3 albertel 499:
500: =item Socket
501:
502: Socket on which the lond transaction occured. This is a
503: LondConnection. The data received is in the TransactionReply member.
504:
1.7 foxr 505: =item Transaction
1.3 albertel 506:
1.7 foxr 507: The transaction that is being completed.
1.1 foxr 508:
509: =cut
1.3 albertel 510:
1.1 foxr 511: sub CompleteTransaction {
1.29 foxr 512: &Debug(5,"Complete transaction");
1.1 foxr 513: my $Socket = shift;
1.7 foxr 514: my $Transaction = shift;
1.1 foxr 515:
1.7 foxr 516: if (!$Transaction->isDeferred()) { # Normal transaction
517: my $data = $Socket->GetReply(); # Data to send.
1.39 ! foxr 518: if($LogTransactions) {
! 519: Log("SUCCESS", "Reply from lond: '$data'");
! 520: }
1.7 foxr 521: StartClientReply($Transaction, $data);
522: } else { # Delete deferred transaction file.
1.9 foxr 523: Log("SUCCESS", "A delayed transaction was completed");
1.23 foxr 524: LogPerm("S:$Transaction->getClient() :".$Transaction->getRequest());
1.7 foxr 525: unlink $Transaction->getFile();
526: }
1.6 foxr 527: }
528: =pod
529: =head1 StartClientReply
530:
531: Initiates a reply to a client where the reply data is a parameter.
532:
1.7 foxr 533: =head2 parameters:
534:
535: =item Transaction
536:
537: The transaction for which we are responding to the client.
538:
539: =item data
540:
541: The data to send to apached client.
542:
1.6 foxr 543: =cut
544: sub StartClientReply {
1.7 foxr 545: my $Transaction = shift;
1.6 foxr 546: my $data = shift;
1.1 foxr 547:
1.12 foxr 548:
1.7 foxr 549: my $Client = $Transaction->getClient();
550:
1.1 foxr 551: &Debug(8," Reply was: ".$data);
552: my $Serial = $ActiveClients{$Client};
553: my $desc = sprintf("Connection to lonc client %d",
554: $Serial);
555: Event->io(fd => $Client,
556: poll => "w",
557: desc => $desc,
558: cb => \&ClientWritable,
559: data => $data);
560: }
1.4 foxr 561: =pod
562: =head2 FailTransaction
563:
564: Finishes a transaction with failure because the associated lond socket
1.7 foxr 565: disconnected. There are two possibilities:
566: - The transaction is deferred: in which case we just quietly
567: delete the transaction since there is no client connection.
568: - The transaction is 'live' in which case we initiate the sending
569: of "con_lost" to the client.
570:
571: Deleting the transaction means killing it from the
572: %ActiveTransactions hash.
1.4 foxr 573:
574: Parameters:
575:
576: =item client
577:
1.7 foxr 578: The LondTransaction we are failing.
579:
1.4 foxr 580: =cut
581:
582: sub FailTransaction {
1.7 foxr 583: my $transaction = shift;
1.17 foxr 584: Log("WARNING", "Failing transaction ".$transaction->getRequest());
1.30 foxr 585: Debug(1, "Failing transaction: ".$transaction->getRequest());
1.10 foxr 586: if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
1.11 foxr 587: my $client = $transaction->getClient();
1.30 foxr 588: Debug(1," Replying con_lost to ".$transaction->getRequest());
1.11 foxr 589: StartClientReply($transaction, "con_lost\n");
1.7 foxr 590: }
1.22 foxr 591: if($ConnectionRetriesLeft <= 0) {
592: Log("CRITICAL", "Host marked dead: ".GetServerHost());
593: }
1.4 foxr 594:
595: }
596:
597: =pod
1.6 foxr 598: =head1 EmptyQueue
1.7 foxr 599:
1.6 foxr 600: Fails all items in the work queue with con_lost.
1.7 foxr 601: Note that each item in the work queue is a transaction.
602:
1.6 foxr 603: =cut
604: sub EmptyQueue {
1.22 foxr 605: $ConnectionRetriesLeft--; # Counts as connection failure too.
1.6 foxr 606: while($WorkQueue->Count()) {
1.10 foxr 607: my $request = $WorkQueue->dequeue(); # This is a transaction
1.7 foxr 608: FailTransaction($request);
1.6 foxr 609: }
610: }
611:
612: =pod
1.4 foxr 613:
1.9 foxr 614: =head2 CloseAllLondConnections
615:
616: Close all connections open on lond prior to exit e.g.
617:
618: =cut
619: sub CloseAllLondConnections {
1.23 foxr 620: foreach my $Socket (keys %ActiveConnections) {
1.9 foxr 621: KillSocket($Socket);
622: }
623: }
624: =cut
625:
626: =pod
627:
1.4 foxr 628: =head2 KillSocket
629:
630: Destroys a socket. This function can be called either when a socket
631: has died of 'natural' causes or because a socket needs to be pruned due to
632: idleness. If the socket has died naturally, if there are no longer any
633: live connections a new connection is created (in case there are transactions
634: in the queue). If the socket has been pruned, it is never re-created.
635:
636: Parameters:
1.1 foxr 637:
1.4 foxr 638: =item Socket
639:
640: The socket to kill off.
641:
642: =item Restart
643:
644: nonzero if we are allowed to create a new connection.
645:
646:
647: =cut
648: sub KillSocket {
649: my $Socket = shift;
650:
1.17 foxr 651: Log("WARNING", "Shutting down a socket");
1.9 foxr 652: $Socket->Shutdown();
653:
1.7 foxr 654: # If the socket came from the active connection set,
655: # delete its transaction... note that FailTransaction should
656: # already have been called!!!
657: # otherwise it came from the idle set.
658: #
1.4 foxr 659:
660: if(exists($ActiveTransactions{$Socket})) {
661: delete ($ActiveTransactions{$Socket});
662: }
663: if(exists($ActiveConnections{$Socket})) {
664: delete($ActiveConnections{$Socket});
1.37 albertel 665: $ConnectionCount--;
666: if ($ConnectionCount < 0) { $ConnectionCount = 0; }
1.4 foxr 667: }
1.6 foxr 668: # If the connection count has gone to zero and there is work in the
669: # work queue, the work all gets failed with con_lost.
670: #
671: if($ConnectionCount == 0) {
1.22 foxr 672: EmptyQueue();
1.4 foxr 673: }
674: }
1.1 foxr 675:
676: =pod
1.3 albertel 677:
1.1 foxr 678: =head2 LondReadable
1.3 albertel 679:
1.1 foxr 680: This function is called whenever a lond connection
681: is readable. The action is state dependent:
682:
1.3 albertel 683: =head3 State=Initialized
684:
685: We''re waiting for the challenge, this is a no-op until the
1.1 foxr 686: state changes.
1.3 albertel 687:
1.1 foxr 688: =head3 State=Challenged
1.3 albertel 689:
690: The challenge has arrived we need to transition to Writable.
1.1 foxr 691: The connection must echo the challenge back.
1.3 albertel 692:
1.1 foxr 693: =head3 State=ChallengeReplied
1.3 albertel 694:
695: The challenge has been replied to. The we are receiveing the
1.1 foxr 696: 'ok' from the partner.
1.3 albertel 697:
1.1 foxr 698: =head3 State=RequestingKey
1.3 albertel 699:
700: The ok has been received and we need to send the request for
1.1 foxr 701: an encryption key. Transition to writable for that.
1.3 albertel 702:
1.1 foxr 703: =head3 State=ReceivingKey
1.3 albertel 704:
705: The the key has been requested, now we are reading the new key.
706:
1.1 foxr 707: =head3 State=Idle
1.3 albertel 708:
709: The encryption key has been negotiated or we have finished
1.1 foxr 710: reading data from the a transaction. If the callback data has
711: a client as well as the socket iformation, then we are
712: doing a transaction and the data received is relayed to the client
713: before the socket is put on the idle list.
1.3 albertel 714:
1.1 foxr 715: =head3 State=SendingRequest
1.3 albertel 716:
717: I do not think this state can be received here, but if it is,
1.1 foxr 718: the appropriate thing to do is to transition to writable, and send
719: the request.
1.3 albertel 720:
1.1 foxr 721: =head3 State=ReceivingReply
1.3 albertel 722:
723: We finished sending the request to the server and now transition
1.1 foxr 724: to readable to receive the reply.
725:
726: The parameter to this function are:
1.3 albertel 727:
1.1 foxr 728: The event. Implicit in this is the watcher and its data. The data
729: contains at least the lond connection object and, if a
730: transaction is in progress, the socket attached to the local client.
731:
1.3 albertel 732: =cut
1.1 foxr 733:
734: sub LondReadable {
1.8 foxr 735:
1.1 foxr 736: my $Event = shift;
737: my $Watcher = $Event->w;
738: my $Socket = $Watcher->data;
739: my $client = undef;
740:
1.23 foxr 741: &Debug(6,"LondReadable called state = ".$Socket->GetState());
1.8 foxr 742:
1.1 foxr 743:
744: my $State = $Socket->GetState(); # All action depends on the state.
745:
746: SocketDump(6, $Socket);
1.12 foxr 747: my $status = $Socket->Readable();
1.17 foxr 748:
1.12 foxr 749: &Debug(2, "Socket->Readable returned: $status");
1.1 foxr 750:
1.12 foxr 751: if($status != 0) {
1.4 foxr 752: # bad return from socket read. Currently this means that
753: # The socket has become disconnected. We fail the transaction.
754:
1.17 foxr 755: Log("WARNING",
756: "Lond connection lost.");
1.4 foxr 757: if(exists($ActiveTransactions{$Socket})) {
758: FailTransaction($ActiveTransactions{$Socket});
759: }
760: $Watcher->cancel();
1.6 foxr 761: KillSocket($Socket);
1.22 foxr 762: $ConnectionRetriesLeft--; # Counts as connection failure
1.4 foxr 763: return;
1.1 foxr 764: }
765: SocketDump(6,$Socket);
766:
767: $State = $Socket->GetState(); # Update in case of transition.
768: &Debug(6, "After read, state is ".$State);
769:
770: if($State eq "Initialized") {
771:
772:
773: } elsif ($State eq "ChallengeReceived") {
774: # The challenge must be echoed back; The state machine
775: # in the connection takes care of setting that up. Just
776: # need to transition to writable:
777:
1.8 foxr 778: $Watcher->cb(\&LondWritable);
1.1 foxr 779: $Watcher->poll("w");
780:
781: } elsif ($State eq "ChallengeReplied") {
782:
783:
784: } elsif ($State eq "RequestingKey") {
785: # The ok was received. Now we need to request the key
786: # That requires us to be writable:
787:
1.8 foxr 788: $Watcher->cb(\&LondWritable);
1.1 foxr 789: $Watcher->poll("w");
790:
791: } elsif ($State eq "ReceivingKey") {
792:
793: } elsif ($State eq "Idle") {
794: # If necessary, complete a transaction and then go into the
795: # idle queue.
1.22 foxr 796: # Note that a trasition to idle indicates a live lond
797: # on the other end so reset the connection retries.
798: #
799: $ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
1.8 foxr 800: $Watcher->cancel();
1.1 foxr 801: if(exists($ActiveTransactions{$Socket})) {
1.29 foxr 802: Debug(5,"Completing transaction!!");
1.1 foxr 803: CompleteTransaction($Socket,
804: $ActiveTransactions{$Socket});
1.9 foxr 805: } else {
806: Log("SUCCESS", "Connection ".$ConnectionCount." to "
807: .$RemoteHost." now ready for action");
1.1 foxr 808: }
809: ServerToIdle($Socket); # Next work unit or idle.
1.6 foxr 810:
1.1 foxr 811: } elsif ($State eq "SendingRequest") {
812: # We need to be writable for this and probably don't belong
813: # here inthe first place.
814:
815: Deubg(6, "SendingRequest state encountered in readable");
816: $Watcher->poll("w");
817: $Watcher->cb(\&LondWritable);
818:
819: } elsif ($State eq "ReceivingReply") {
820:
821:
822: } else {
823: # Invalid state.
824: Debug(4, "Invalid state in LondReadable");
825: }
826: }
1.3 albertel 827:
1.1 foxr 828: =pod
1.3 albertel 829:
1.1 foxr 830: =head2 LondWritable
1.3 albertel 831:
1.1 foxr 832: This function is called whenever a lond connection
833: becomes writable while there is a writeable monitoring
834: event. The action taken is very state dependent:
1.3 albertel 835:
1.1 foxr 836: =head3 State = Connected
1.3 albertel 837:
838: The connection is in the process of sending the 'init' hailing to the
839: lond on the remote end. The connection object''s Writable member is
840: called. On error, ConnectionError is called to destroy the connection
841: and remove it from the ActiveConnections hash
842:
1.1 foxr 843: =head3 Initialized
1.3 albertel 844:
845: 'init' has been sent, writability monitoring is removed and
846: readability monitoring is started with LondReadable as the callback.
847:
1.1 foxr 848: =head3 ChallengeReceived
1.3 albertel 849:
850: The connection has received the who are you challenge from the remote
851: system, and is in the process of sending the challenge
852: response. Writable is called.
853:
1.1 foxr 854: =head3 ChallengeReplied
1.3 albertel 855:
856: The connection has replied to the initial challenge The we switch to
857: monitoring readability looking for the server to reply with 'ok'.
858:
1.1 foxr 859: =head3 RequestingKey
1.3 albertel 860:
861: The connection is in the process of requesting its encryption key.
862: Writable is called.
863:
1.1 foxr 864: =head3 ReceivingKey
1.3 albertel 865:
866: The connection has sent the request for a key. Switch to readability
867: monitoring to accept the key
868:
1.1 foxr 869: =head3 SendingRequest
1.3 albertel 870:
871: The connection is in the process of sending a request to the server.
872: This request is part of a client transaction. All the states until
873: now represent the client setup protocol. Writable is called.
874:
1.1 foxr 875: =head3 ReceivingReply
876:
1.3 albertel 877: The connection has sent a request. Now it must receive a reply.
878: Readability monitoring is requested.
879:
880: This function is an event handler and therefore receives as
1.1 foxr 881: a parameter the event that has fired. The data for the watcher
882: of this event is a reference to a list of one or two elements,
883: depending on state. The first (and possibly only) element is the
884: socket. The second (present only if a request is in progress)
885: is the socket on which to return a reply to the caller.
886:
887: =cut
1.3 albertel 888:
1.1 foxr 889: sub LondWritable {
890: my $Event = shift;
891: my $Watcher = $Event->w;
1.8 foxr 892: my $Socket = $Watcher->data;
893: my $State = $Socket->GetState();
1.1 foxr 894:
1.8 foxr 895: Debug(6,"LondWritable State = ".$State."\n");
1.1 foxr 896:
1.8 foxr 897:
1.1 foxr 898: # Figure out what to do depending on the state of the socket:
899:
900:
901:
902:
903: SocketDump(6,$Socket);
904:
905: if ($State eq "Connected") {
906:
907: if ($Socket->Writable() != 0) {
908: # The write resulted in an error.
1.4 foxr 909: # We'll treat this as if the socket got disconnected:
1.9 foxr 910: Log("WARNING", "Connection to ".$RemoteHost.
911: " has been disconnected");
1.18 foxr 912: FailTransaction($ActiveTransactions{$Socket});
1.4 foxr 913: $Watcher->cancel();
1.6 foxr 914: KillSocket($Socket);
1.4 foxr 915: return;
1.1 foxr 916: }
1.4 foxr 917: # "init" is being sent...
918:
1.1 foxr 919:
920: } elsif ($State eq "Initialized") {
921:
922: # Now that init was sent, we switch
923: # to watching for readability:
924:
1.8 foxr 925: $Watcher->cb(\&LondReadable);
1.1 foxr 926: $Watcher->poll("r");
927:
928: } elsif ($State eq "ChallengeReceived") {
929: # We received the challenge, now we
930: # are echoing it back. This is a no-op,
931: # we're waiting for the state to change
932:
933: if($Socket->Writable() != 0) {
1.5 foxr 934:
935: $Watcher->cancel();
1.6 foxr 936: KillSocket($Socket);
1.5 foxr 937: return;
1.1 foxr 938: }
939:
940: } elsif ($State eq "ChallengeReplied") {
941: # The echo was sent back, so we switch
942: # to watching readability.
943:
1.8 foxr 944: $Watcher->cb(\&LondReadable);
1.1 foxr 945: $Watcher->poll("r");
946:
947: } elsif ($State eq "RequestingKey") {
948: # At this time we're requesting the key.
949: # again, this is essentially a no-op.
950: # we'll write the next chunk until the
951: # state changes.
952:
953: if($Socket->Writable() != 0) {
954: # Write resulted in an error.
1.5 foxr 955:
956: $Watcher->cancel();
1.6 foxr 957: KillSocket($Socket);
1.5 foxr 958: return;
959:
1.1 foxr 960: }
961: } elsif ($State eq "ReceivingKey") {
962: # Now we need to wait for the key
963: # to come back from the peer:
964:
1.8 foxr 965: $Watcher->cb(\&LondReadable);
1.1 foxr 966: $Watcher->poll("r");
967:
968: } elsif ($State eq "SendingRequest") {
969: # At this time we are sending a request to the
970: # peer... write the next chunk:
971:
972: if($Socket->Writable() != 0) {
973:
1.5 foxr 974: if(exists($ActiveTransactions{$Socket})) {
975: Debug(3, "Lond connection lost, failing transactions");
976: FailTransaction($ActiveTransactions{$Socket});
977: }
978: $Watcher->cancel();
1.6 foxr 979: KillSocket($Socket);
1.5 foxr 980: return;
981:
1.1 foxr 982: }
983:
984: } elsif ($State eq "ReceivingReply") {
985: # The send has completed. Wait for the
986: # data to come in for a reply.
987: Debug(8,"Writable sent request/receiving reply");
1.8 foxr 988: $Watcher->cb(\&LondReadable);
1.1 foxr 989: $Watcher->poll("r");
990:
991: } else {
992: # Control only passes here on an error:
993: # the socket state does not match any
994: # of the known states... so an error
995: # must be logged.
996:
997: &Debug(4, "Invalid socket state ".$State."\n");
998: }
999:
1000: }
1.6 foxr 1001: =pod
1002:
1003: =cut
1004: sub QueueDelayed {
1.8 foxr 1005: Debug(3,"QueueDelayed called");
1006:
1.6 foxr 1007: my $path = "$perlvar{'lonSockDir'}/delayed";
1.8 foxr 1008:
1009: Debug(4, "Delayed path: ".$path);
1.6 foxr 1010: opendir(DIRHANDLE, $path);
1.8 foxr 1011:
1.23 foxr 1012: my @alldelayed = grep /\.$RemoteHost$/, readdir DIRHANDLE;
1.6 foxr 1013: closedir(DIRHANDLE);
1014: my $dfname;
1.8 foxr 1015: my $reqfile;
1016: foreach $dfname (sort @alldelayed) {
1017: $reqfile = "$path/$dfname";
1018: Debug(4, "queueing ".$reqfile);
1.6 foxr 1019: my $Handle = IO::File->new($reqfile);
1020: my $cmd = <$Handle>;
1.8 foxr 1021: chomp $cmd; # There may or may not be a newline...
1.12 foxr 1022: $cmd = $cmd."\n"; # now for sure there's exactly one newline.
1.7 foxr 1023: my $Transaction = LondTransaction->new($cmd);
1024: $Transaction->SetDeferred($reqfile);
1025: QueueTransaction($Transaction);
1.6 foxr 1026: }
1027:
1028: }
1.1 foxr 1029:
1030: =pod
1.3 albertel 1031:
1.1 foxr 1032: =head2 MakeLondConnection
1.3 albertel 1033:
1034: Create a new lond connection object, and start it towards its initial
1035: idleness. Once idle, it becomes elligible to receive transactions
1036: from the work queue. If the work queue is not empty when the
1037: connection is completed and becomes idle, it will dequeue an entry and
1038: start off on it.
1039:
1.1 foxr 1040: =cut
1.3 albertel 1041:
1.1 foxr 1042: sub MakeLondConnection {
1043: Debug(4,"MakeLondConnection to ".GetServerHost()." on port "
1044: .GetServerPort());
1045:
1046: my $Connection = LondConnection->new(&GetServerHost(),
1047: &GetServerPort());
1048:
1.30 foxr 1049: if($Connection eq undef) { # Needs to be more robust later.
1.9 foxr 1050: Log("CRITICAL","Failed to make a connection with lond.");
1.10 foxr 1051: $ConnectionRetriesLeft--;
1052: return 0; # Failure.
1.5 foxr 1053: } else {
1.22 foxr 1054:
1.5 foxr 1055: # The connection needs to have writability
1056: # monitored in order to send the init sequence
1057: # that starts the whole authentication/key
1058: # exchange underway.
1059: #
1060: my $Socket = $Connection->GetSocket();
1.30 foxr 1061: if($Socket eq undef) {
1.5 foxr 1062: die "did not get a socket from the connection";
1063: } else {
1064: &Debug(9,"MakeLondConnection got socket: ".$Socket);
1065: }
1.1 foxr 1066:
1.21 foxr 1067: $Connection->SetTimeoutCallback(\&SocketTimeout);
1068:
1.23 foxr 1069: my $event = Event->io(fd => $Socket,
1.5 foxr 1070: poll => 'w',
1071: cb => \&LondWritable,
1.8 foxr 1072: data => $Connection,
1.5 foxr 1073: desc => 'Connection to lond server');
1074: $ActiveConnections{$Connection} = $event;
1075:
1076: $ConnectionCount++;
1.8 foxr 1077: Debug(4, "Connection count = ".$ConnectionCount);
1.6 foxr 1078: if($ConnectionCount == 1) { # First Connection:
1079: QueueDelayed;
1080: }
1.9 foxr 1081: Log("SUCESS", "Created connection ".$ConnectionCount
1082: ." to host ".GetServerHost());
1.10 foxr 1083: return 1; # Return success.
1.1 foxr 1084: }
1085:
1086: }
1.3 albertel 1087:
1.1 foxr 1088: =pod
1.3 albertel 1089:
1.1 foxr 1090: =head2 StartRequest
1.3 albertel 1091:
1092: Starts a lond request going on a specified lond connection.
1093: parameters are:
1094:
1095: =item $Lond
1096:
1097: Connection to the lond that will send the transaction and receive the
1098: reply.
1099:
1100: =item $Client
1101:
1102: Connection to the client that is making this request We got the
1103: request from this socket, and when the request has been relayed to
1104: lond and we get a reply back from lond it will get sent to this
1105: socket.
1106:
1107: =item $Request
1108:
1109: The text of the request to send.
1110:
1.1 foxr 1111: =cut
1112:
1113: sub StartRequest {
1114: my $Lond = shift;
1.7 foxr 1115: my $Request = shift; # This is a LondTransaction.
1.1 foxr 1116:
1.7 foxr 1117: Debug(6, "StartRequest: ".$Request->getRequest());
1.1 foxr 1118:
1119: my $Socket = $Lond->GetSocket();
1120:
1.7 foxr 1121: $Request->Activate($Lond);
1122: $ActiveTransactions{$Lond} = $Request;
1.1 foxr 1123:
1.7 foxr 1124: $Lond->InitiateTransaction($Request->getRequest());
1.23 foxr 1125: my $event = Event->io(fd => $Socket,
1.1 foxr 1126: poll => "w",
1127: cb => \&LondWritable,
1128: data => $Lond,
1129: desc => "lond transaction connection");
1130: $ActiveConnections{$Lond} = $event;
1131: Debug(8," Start Request made watcher data with ".$event->data."\n");
1132: }
1133:
1134: =pod
1.3 albertel 1135:
1.1 foxr 1136: =head2 QueueTransaction
1.3 albertel 1137:
1138: If there is an idle lond connection, it is put to work doing this
1139: transaction. Otherwise, the transaction is placed in the work queue.
1140: If placed in the work queue and the maximum number of connections has
1141: not yet been created, a new connection will be started. Our goal is
1142: to eventually have a sufficient number of connections that the work
1143: queue will typically be empty. parameters are:
1144:
1145: =item Socket
1146:
1147: open on the lonc client.
1148:
1149: =item Request
1150:
1151: data to send to the lond.
1.1 foxr 1152:
1153: =cut
1.3 albertel 1154:
1.1 foxr 1155: sub QueueTransaction {
1156:
1.7 foxr 1157: my $requestData = shift; # This is a LondTransaction.
1158: my $cmd = $requestData->getRequest();
1159:
1160: Debug(6,"QueueTransaction: ".$cmd);
1.1 foxr 1161:
1162: my $LondSocket = $IdleConnections->pop();
1163: if(!defined $LondSocket) { # Need to queue request.
1.29 foxr 1164: Debug(5,"Must queue...");
1.1 foxr 1165: $WorkQueue->enqueue($requestData);
1166: if($ConnectionCount < $MaxConnectionCount) {
1.22 foxr 1167: if($ConnectionRetriesLeft > 0) {
1.29 foxr 1168: Debug(5,"Starting additional lond connection");
1.22 foxr 1169: if(MakeLondConnection() == 0) {
1170: EmptyQueue(); # Fail transactions, can't make connection.
1171: }
1172: } else {
1173: ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
1174: EmptyQueue(); # It's worse than that ... he's dead Jim.
1.17 foxr 1175: }
1.1 foxr 1176: }
1177: } else { # Can start the request:
1178: Debug(8,"Can start...");
1.7 foxr 1179: StartRequest($LondSocket, $requestData);
1.1 foxr 1180: }
1181: }
1182:
1183: #-------------------------- Lonc UNIX socket handling ---------------------
1.3 albertel 1184:
1.1 foxr 1185: =pod
1.3 albertel 1186:
1.1 foxr 1187: =head2 ClientRequest
1.3 albertel 1188: Callback that is called when data can be read from the UNIX domain
1189: socket connecting us with an apache server process.
1.1 foxr 1190:
1191: =cut
1192:
1193: sub ClientRequest {
1194: Debug(6, "ClientRequest");
1195: my $event = shift;
1196: my $watcher = $event->w;
1197: my $socket = $watcher->fd;
1198: my $data = $watcher->data;
1199: my $thisread;
1200:
1201: Debug(9, " Watcher named: ".$watcher->desc);
1202:
1203: my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
1204: Debug(8, "rcv: data length = ".length($thisread)
1205: ." read =".$thisread);
1.29 foxr 1206: unless (defined $rv && length($thisread)) {
1.1 foxr 1207: # Likely eof on socket.
1208: Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
1209: close($socket);
1210: $watcher->cancel();
1211: delete($ActiveClients{$socket});
1.10 foxr 1212: return;
1.1 foxr 1213: }
1214: Debug(8,"Data: ".$data." this read: ".$thisread);
1215: $data = $data.$thisread; # Append new data.
1216: $watcher->data($data);
1217: if($data =~ /(.*\n)/) { # Request entirely read.
1.10 foxr 1218: if($data eq "close_connection_exit\n") {
1.9 foxr 1219: Log("CRITICAL",
1220: "Request Close Connection ... exiting");
1221: CloseAllLondConnections();
1222: exit;
1223: }
1.1 foxr 1224: Debug(8, "Complete transaction received: ".$data);
1.39 ! foxr 1225: if($LogTransactions) {
! 1226: Log("SUCCESS", "Transaction: '$data'"); # Transaction has \n.
! 1227: }
1.8 foxr 1228: my $Transaction = LondTransaction->new($data);
1.7 foxr 1229: $Transaction->SetClient($socket);
1230: QueueTransaction($Transaction);
1.1 foxr 1231: $watcher->cancel(); # Done looking for input data.
1232: }
1233:
1234: }
1235:
1236:
1237: =pod
1.3 albertel 1238:
1.1 foxr 1239: =head2 NewClient
1.3 albertel 1240:
1241: Callback that is called when a connection is received on the unix
1242: socket for a new client of lonc. The callback is parameterized by the
1243: event.. which is a-priori assumed to be an io event, and therefore has
1244: an fd member that is the Listener socket. We Accept the connection
1245: and register a new event on the readability of that socket:
1246:
1.1 foxr 1247: =cut
1.3 albertel 1248:
1.1 foxr 1249: sub NewClient {
1250: Debug(6, "NewClient");
1251: my $event = shift; # Get the event parameters.
1252: my $watcher = $event->w;
1253: my $socket = $watcher->fd; # Get the event' socket.
1254: my $connection = $socket->accept(); # Accept the client connection.
1255: Debug(8,"Connection request accepted from "
1256: .GetPeername($connection, AF_UNIX));
1257:
1258:
1259: my $description = sprintf("Connection to lonc client %d",
1260: $ClientConnection);
1261: Debug(9, "Creating event named: ".$description);
1262: Event->io(cb => \&ClientRequest,
1263: poll => 'r',
1264: desc => $description,
1265: data => "",
1266: fd => $connection);
1267: $ActiveClients{$connection} = $ClientConnection;
1268: $ClientConnection++;
1269: }
1.3 albertel 1270:
1271: =pod
1272:
1273: =head2 GetLoncSocketPath
1274:
1275: Returns the name of the UNIX socket on which to listen for client
1276: connections.
1.1 foxr 1277:
1278: =cut
1.3 albertel 1279:
1.1 foxr 1280: sub GetLoncSocketPath {
1281: return $UnixSocketDir."/".GetServerHost();
1282: }
1283:
1.3 albertel 1284: =pod
1285:
1286: =head2 GetServerHost
1287:
1288: Returns the host whose lond we talk with.
1289:
1.1 foxr 1290: =cut
1.3 albertel 1291:
1.7 foxr 1292: sub GetServerHost {
1.1 foxr 1293: return $RemoteHost; # Setup by the fork.
1294: }
1.3 albertel 1295:
1296: =pod
1297:
1298: =head2 GetServerPort
1299:
1300: Returns the lond port number.
1301:
1.1 foxr 1302: =cut
1.3 albertel 1303:
1.7 foxr 1304: sub GetServerPort {
1.1 foxr 1305: return $perlvar{londPort};
1306: }
1.3 albertel 1307:
1308: =pod
1309:
1310: =head2 SetupLoncListener
1311:
1312: Setup a lonc listener event. The event is called when the socket
1313: becomes readable.. that corresponds to the receipt of a new
1314: connection. The event handler established will accept the connection
1315: (creating a communcations channel), that int turn will establish
1316: another event handler to subess requests.
1.1 foxr 1317:
1318: =cut
1.3 albertel 1319:
1.1 foxr 1320: sub SetupLoncListener {
1321:
1322: my $socket;
1323: my $SocketName = GetLoncSocketPath();
1324: unlink($SocketName);
1.7 foxr 1325: unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,
1.1 foxr 1326: Listen => 10,
1327: Type => SOCK_STREAM)) {
1328: die "Failed to create a lonc listner socket";
1329: }
1330: Event->io(cb => \&NewClient,
1331: poll => 'r',
1332: desc => 'Lonc listener Unix Socket',
1333: fd => $socket);
1334: }
1335:
1.39 ! foxr 1336: #
! 1337: # Toggle transaction logging.
! 1338: # Implicit inputs:
! 1339: # LogTransactions
! 1340: # Implicit Outputs:
! 1341: # LogTransactions
! 1342: sub ToggleTransactionLogging {
! 1343: print STDERR "Toggle transaction logging...\n";
! 1344: if(!$LogTransactions) {
! 1345: $LogTransactions = 1;
! 1346: } else {
! 1347: $LogTransactions = 0;
! 1348: }
! 1349:
! 1350:
! 1351: Log("SUCCESS", "Toggled transaction logging: $LogTransactions \n");
! 1352: }
! 1353:
1.14 foxr 1354: =pod
1355:
1356: =head2 ChildStatus
1357:
1358: Child USR1 signal handler to report the most recent status
1359: into the status file.
1360:
1.22 foxr 1361: We also use this to reset the retries count in order to allow the
1362: client to retry connections with a previously dead server.
1.14 foxr 1363: =cut
1364: sub ChildStatus {
1365: my $event = shift;
1366: my $watcher = $event->w;
1367:
1368: Debug(2, "Reporting child status because : ".$watcher->data);
1369: my $docdir = $perlvar{'lonDocRoot'};
1370: my $fh = IO::File->new(">>$docdir/lon-status/loncstatus.txt");
1371: print $fh $$."\t".$RemoteHost."\t".$Status."\t".
1372: $RecentLogEntry."\n";
1.38 foxr 1373: #
1374: # Write out information about each of the connections:
1375: #
1376: print $fh "Active connection statuses: \n";
1377: my $i = 1;
1378: print STDERR "================================= Socket Status Dump:\n";
1379: foreach my $item (keys %ActiveConnections) {
1380: my $Socket = $ActiveConnections{$item}->data;
1381: my $state = $Socket->GetState();
1382: print $fh "Connection $i State: $state\n";
1383: print STDERR "---------------------- Connection $i \n";
1384: $Socket->Dump();
1385: $i++;
1386: }
1.22 foxr 1387: $ConnectionRetriesLeft = $ConnectionRetries;
1.14 foxr 1388: }
1389:
1.1 foxr 1390: =pod
1.3 albertel 1391:
1.10 foxr 1392: =head2 SignalledToDeath
1393:
1394: Called in response to a signal that causes a chid process to die.
1395:
1396: =cut
1397:
1398:
1399: sub SignalledToDeath {
1.14 foxr 1400: my $event = shift;
1401: my $watcher= $event->w;
1402:
1403: Debug(2,"Signalled to death! via ".$watcher->data);
1.17 foxr 1404: my ($signal) = $watcher->data;
1.10 foxr 1405: chomp($signal);
1406: Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "
1407: ."died through "."\"$signal\"");
1408: LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
1409: ."\"$signal\"");
1.12 foxr 1410: exit 0;
1.10 foxr 1411:
1412: }
1.16 foxr 1413:
1414: =head2 ToggleDebug
1415:
1416: This sub toggles trace debugging on and off.
1417:
1418: =cut
1419:
1420: sub ToggleDebug {
1421: my $Current = $DebugLevel;
1422: $DebugLevel = $NextDebugLevel;
1423: $NextDebugLevel = $Current;
1424:
1425: Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel");
1426:
1427: }
1428:
1.1 foxr 1429: =head2 ChildProcess
1430:
1431: This sub implements a child process for a single lonc daemon.
1432:
1433: =cut
1434:
1435: sub ChildProcess {
1436:
1437:
1.14 foxr 1438: #
1439: # Signals must be handled by the Event framework...
1440: #
1441:
1442: Event->signal(signal => "QUIT",
1443: cb => \&SignalledToDeath,
1444: data => "QUIT");
1445: Event->signal(signal => "HUP",
1446: cb => \&ChildStatus,
1447: data => "HUP");
1448: Event->signal(signal => "USR1",
1449: cb => \&ChildStatus,
1450: data => "USR1");
1.39 ! foxr 1451: Event->signal(signal => "USR2",
! 1452: cb => \&ToggleTransactionLogging);
1.16 foxr 1453: Event->signal(signal => "INT",
1454: cb => \&ToggleDebug,
1455: data => "INT");
1.1 foxr 1456:
1457: SetupTimer();
1458:
1459: SetupLoncListener();
1460:
1461: $Event::Debuglevel = $DebugLevel;
1462:
1463: Debug(9, "Making initial lond connection for ".$RemoteHost);
1464:
1465: # Setup the initial server connection:
1466:
1.14 foxr 1467: # &MakeLondConnection(); // let first work requirest do it.
1.10 foxr 1468:
1.5 foxr 1469:
1.1 foxr 1470: Debug(9,"Entering event loop");
1471: my $ret = Event::loop(); # Start the main event loop.
1472:
1473:
1474: die "Main event loop exited!!!";
1475: }
1476:
1477: # Create a new child for host passed in:
1478:
1479: sub CreateChild {
1.12 foxr 1480: my $sigset = POSIX::SigSet->new(SIGINT);
1481: sigprocmask(SIG_BLOCK, $sigset);
1.1 foxr 1482: my $host = shift;
1483: $RemoteHost = $host;
1.9 foxr 1484: Log("CRITICAL", "Forking server for ".$host);
1.23 foxr 1485: my $pid = fork;
1.1 foxr 1486: if($pid) { # Parent
1.17 foxr 1487: $RemoteHost = "Parent";
1.27 foxr 1488: $ChildHash{$pid} = $host;
1.26 foxr 1489: $HostToPid{$host}= $pid;
1.12 foxr 1490: sigprocmask(SIG_UNBLOCK, $sigset);
1491:
1.1 foxr 1492: } else { # child.
1.5 foxr 1493: ShowStatus("Connected to ".$RemoteHost);
1.23 foxr 1494: $SIG{INT} = 'DEFAULT';
1.12 foxr 1495: sigprocmask(SIG_UNBLOCK, $sigset);
1496: ChildProcess; # Does not return.
1.1 foxr 1497: }
1498:
1499: }
1500: #
1501: # Parent process logic pass 1:
1502: # For each entry in the hosts table, we will
1503: # fork off an instance of ChildProcess to service the transactions
1504: # to that host. Each pid will be entered in a global hash
1505: # with the value of the key, the host.
1506: # The parent will then enter a loop to wait for process exits.
1507: # Each exit gets logged and the child gets restarted.
1508: #
1509:
1.5 foxr 1510: #
1511: # Fork and start in new session so hang-up isn't going to
1512: # happen without intent.
1513: #
1514:
1515:
1.6 foxr 1516:
1517:
1.8 foxr 1518:
1.6 foxr 1519:
1520: ShowStatus("Forming new session");
1521: my $childpid = fork;
1522: if ($childpid != 0) {
1523: sleep 4; # Give child a chacne to break to
1524: exit 0; # a new sesion.
1525: }
1.8 foxr 1526: #
1527: # Write my pid into the pid file so I can be located
1528: #
1529:
1530: ShowStatus("Parent writing pid file:");
1.23 foxr 1531: my $execdir = $perlvar{'lonDaemons'};
1.8 foxr 1532: open (PIDSAVE, ">$execdir/logs/lonc.pid");
1533: print PIDSAVE "$$\n";
1534: close(PIDSAVE);
1.6 foxr 1535:
1.17 foxr 1536:
1537:
1.6 foxr 1538: if (POSIX::setsid() < 0) {
1539: print "Could not create new session\n";
1540: exit -1;
1541: }
1.5 foxr 1542:
1543: ShowStatus("Forking node servers");
1544:
1.9 foxr 1545: Log("CRITICAL", "--------------- Starting children ---------------");
1546:
1.31 foxr 1547: LondConnection::ReadConfig; # Read standard config files.
1.1 foxr 1548: my $HostIterator = LondConnection::GetHostIterator;
1549: while (! $HostIterator->end()) {
1550:
1.23 foxr 1551: my $hostentryref = $HostIterator->get();
1.1 foxr 1552: CreateChild($hostentryref->[0]);
1.26 foxr 1553: $HostHash{$hostentryref->[0]} = $hostentryref->[4];
1.1 foxr 1554: $HostIterator->next();
1555: }
1.12 foxr 1556: $RemoteHost = "Parent Server";
1.1 foxr 1557:
1558: # Maintain the population:
1.5 foxr 1559:
1560: ShowStatus("Parent keeping the flock");
1.1 foxr 1561:
1.10 foxr 1562: #
1563: # Set up parent signals:
1564: #
1.12 foxr 1565:
1.14 foxr 1566: $SIG{INT} = \&Terminate;
1567: $SIG{TERM} = \&Terminate;
1.13 foxr 1568: $SIG{HUP} = \&Restart;
1.14 foxr 1569: $SIG{USR1} = \&CheckKids;
1.24 foxr 1570: $SIG{USR2} = \&UpdateKids; # LonManage update request.
1.10 foxr 1571:
1.1 foxr 1572: while(1) {
1.23 foxr 1573: my $deadchild = wait();
1.1 foxr 1574: if(exists $ChildHash{$deadchild}) { # need to restart.
1.23 foxr 1575: my $deadhost = $ChildHash{$deadchild};
1.26 foxr 1576: delete($HostToPid{$deadhost});
1.1 foxr 1577: delete($ChildHash{$deadchild});
1.9 foxr 1578: Log("WARNING","Lost child pid= ".$deadchild.
1.1 foxr 1579: "Connected to host ".$deadhost);
1.9 foxr 1580: Log("INFO", "Restarting child procesing ".$deadhost);
1.1 foxr 1581: CreateChild($deadhost);
1582: }
1.13 foxr 1583: }
1584:
1.14 foxr 1585:
1586:
1587: =pod
1588:
1589: =head1 CheckKids
1590:
1591: Since kids do not die as easily in this implementation
1592: as the previous one, there is no need to restart the
1593: dead ones (all dead kids get restarted when they die!!)
1594: The only thing this function does is to pass USR1 to the
1595: kids so that they report their status.
1596:
1597: =cut
1598:
1599: sub CheckKids {
1600: Debug(2, "Checking status of children");
1601: my $docdir = $perlvar{'lonDocRoot'};
1602: my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt");
1603: my $now=time;
1604: my $local=localtime($now);
1605: print $fh "LONC status $local - parent $$ \n\n";
1.23 foxr 1606: foreach my $pid (keys %ChildHash) {
1.14 foxr 1607: Debug(2, "Sending USR1 -> $pid");
1608: kill 'USR1' => $pid; # Tell Child to report status.
1609: sleep 1; # Wait so file doesn't intermix.
1610: }
1611: }
1.24 foxr 1612:
1613: =pod
1614:
1615: =head1 UpdateKids
1616:
1.25 foxr 1617: parent's SIGUSR2 handler. This handler:
1.24 foxr 1618:
1619: =item
1620:
1621: Rereads the hosts file.
1622:
1623: =item
1624:
1625: Kills off (via sigint) children for hosts that have disappeared.
1626:
1627: =item
1628:
1.27 foxr 1629: QUITs children for hosts that already exist (this just forces a status display
1.24 foxr 1630: and resets the connection retry count for that host.
1631:
1632: =item
1633:
1634: Starts new children for hosts that have been added to the hosts.tab file since
1635: the start of the master program and maintains them.
1636:
1637: =cut
1638:
1639: sub UpdateKids {
1.27 foxr 1640:
1.25 foxr 1641: Log("INFO", "Updating connections via SIGUSR2");
1.27 foxr 1642:
1643: # Just in case we need to kill our own lonc, we wait a few seconds to
1644: # give it a chance to receive and relay lond's response to the
1645: # re-init command.
1646: #
1647:
1648: sleep(2); # Wait a couple of seconds.
1649:
1650: my %hosts; # Indexed by loncapa hostname, value=ip.
1651:
1652: # Need to re-read the host table:
1653:
1654:
1655: LondConnection::ReadConfig();
1656: my $I = LondConnection::GetHostIterator;
1657: while (! $I->end()) {
1658: my $item = $I->get();
1659: $hosts{$item->[0]} = $item->[4];
1660: $I->next();
1661: }
1662:
1663: # The logic below is written for clarity not for efficiency.
1664: # Since I anticipate that this function is only rarely called, that's
1665: # appropriate. There are certainly ways to combine the loops below,
1666: # and anyone wishing to obscure the logic is welcome to go for it.
1667: # Note that we don't re-direct sigchild. Instead we do what's needed
1668: # to the data structures that keep track of children to ensure that
1669: # when sigchild is honored, no new child is born.
1670: #
1671:
1672: # For each existing child; if it's host doesn't exist, kill the child.
1673:
1674: foreach my $child (keys %ChildHash) {
1675: my $oldhost = $ChildHash{$child};
1676: if (!(exists $hosts{$oldhost})) {
1677: Log("CRITICAL", "Killing child for $oldhost host no longer exists");
1678: delete $ChildHash{$child};
1679: delete $HostToPid{$oldhost};
1680: kill 'QUIT' => $child;
1681: }
1682: }
1683: # For each remaining existing child; if it's host's ip has changed,
1684: # Restart the child on the new IP.
1685:
1686: foreach my $child (keys %ChildHash) {
1687: my $oldhost = $ChildHash{$child};
1688: my $oldip = $HostHash{$oldhost};
1689: if ($hosts{$oldhost} ne $oldip) {
1690:
1691: # kill the old child.
1692:
1693: Log("CRITICAL", "Killing child for $oldhost host ip has changed...");
1694: delete $ChildHash{$child};
1695: delete $HostToPid{$oldhost};
1696: kill 'QUIT' => $child;
1697:
1698: # Do the book-keeping needed to start a new child on the
1699: # new ip.
1700:
1701: $HostHash{$oldhost} = $hosts{$oldhost};
1702: CreateChild($oldhost);
1703: }
1704: }
1705: # Finally, for each new host, not in the host hash, create a
1706: # enter the host and create a new child.
1707: # Force a status display of any existing process.
1708:
1709: foreach my $host (keys %hosts) {
1710: if(!(exists $HostHash{$host})) {
1711: Log("INFO", "New host $host discovered in hosts.tab...");
1712: $HostHash{$host} = $hosts{$host};
1713: CreateChild($host);
1714: } else {
1715: kill 'HUP' => $HostToPid{$host}; # status display.
1716: }
1717: }
1.24 foxr 1718: }
1719:
1.14 foxr 1720:
1.13 foxr 1721: =pod
1722:
1723: =head1 Restart
1724:
1725: Signal handler for HUP... all children are killed and
1726: we self restart. This is an el-cheapo way to re read
1727: the config file.
1728:
1729: =cut
1730:
1731: sub Restart {
1.23 foxr 1732: &KillThemAll; # First kill all the children.
1.13 foxr 1733: Log("CRITICAL", "Restarting");
1734: my $execdir = $perlvar{'lonDaemons'};
1735: unlink("$execdir/logs/lonc.pid");
1.28 albertel 1736: exec("$execdir/loncnew");
1.10 foxr 1737: }
1.12 foxr 1738:
1739: =pod
1740:
1741: =head1 KillThemAll
1742:
1743: Signal handler that kills all children by sending them a
1.17 foxr 1744: SIGHUP. Responds to sigint and sigterm.
1.12 foxr 1745:
1746: =cut
1747:
1.10 foxr 1748: sub KillThemAll {
1.12 foxr 1749: Debug(2, "Kill them all!!");
1750: local($SIG{CHLD}) = 'IGNORE'; # Our children >will< die.
1.23 foxr 1751: foreach my $pid (keys %ChildHash) {
1.12 foxr 1752: my $serving = $ChildHash{$pid};
1753: Debug(2, "Killing lonc for $serving pid = $pid");
1754: ShowStatus("Killing lonc for $serving pid = $pid");
1755: Log("CRITICAL", "Killing lonc for $serving pid = $pid");
1.17 foxr 1756: kill 'QUIT' => $pid;
1757: delete($ChildHash{$pid});
1.12 foxr 1758: }
1.14 foxr 1759: my $execdir = $perlvar{'lonDaemons'};
1760: unlink("$execdir/logs/lonc.pid");
1.17 foxr 1761:
1.1 foxr 1762: }
1.12 foxr 1763:
1.14 foxr 1764: =pod
1765:
1766: =head1 Terminate
1767:
1768: Terminate the system.
1769:
1770: =cut
1771:
1772: sub Terminate {
1773: KillThemAll;
1.17 foxr 1774: Log("CRITICAL","Master process exiting");
1775: exit 0;
1.14 foxr 1776:
1777: }
1.12 foxr 1778: =pod
1.1 foxr 1779:
1780: =head1 Theory
1.3 albertel 1781:
1782: The event class is used to build this as a single process with an
1783: event driven model. The following events are handled:
1.1 foxr 1784:
1785: =item UNIX Socket connection Received
1786:
1787: =item Request data arrives on UNIX data transfer socket.
1788:
1789: =item lond connection becomes writable.
1790:
1791: =item timer fires at 1 second intervals.
1792:
1793: All sockets are run in non-blocking mode. Timeouts managed by the timer
1794: handler prevents hung connections.
1795:
1796: Key data structures:
1797:
1.3 albertel 1798: =item RequestQueue
1799:
1800: A queue of requests received from UNIX sockets that are
1801: waiting for a chance to be forwarded on a lond connection socket.
1802:
1803: =item ActiveConnections
1804:
1805: A hash of lond connections that have transactions in process that are
1806: available to be timed out.
1807:
1808: =item ActiveTransactions
1809:
1810: A hash indexed by lond connections that contain the client reply
1811: socket for each connection that has an active transaction on it.
1812:
1813: =item IdleConnections
1814:
1815: A hash of lond connections that have no work to do. These connections
1816: can be closed if they are idle for a long enough time.
1.1 foxr 1817:
1818: =cut
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