Annotation of loncom/loncnew, revision 1.13
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: #
1.12 foxr 5: # $Id: loncnew,v 1.11 2003/06/25 01:54:44 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).
10: #
11: # LON-CAPA is free software; you can redistribute it and/or modify
12: # it under the terms of the GNU General Public License as published by
13: # the Free Software Foundation; either version 2 of the License, or
14: # (at your option) any later version.
15: #
16: # LON-CAPA is distributed in the hope that it will be useful,
17: # but WITHOUT ANY WARRANTY; without even the implied warranty of
18: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19: # GNU General Public License for more details.
20: #
21: # You should have received a copy of the GNU General Public License
22: # along with LON-CAPA; if not, write to the Free Software
23: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24: #
25: # /home/httpd/html/adm/gpl.txt
26: #
27: # http://www.lon-capa.org/
28: #
1.1 foxr 29: #
30: # new lonc handles n requestors spread out bver m connections to londs.
31: # This module is based on the Event class.
32: # Development iterations:
33: # - Setup basic event loop. (done)
34: # - Add timer dispatch. (done)
35: # - Add ability to accept lonc UNIX domain sockets. (done)
36: # - Add ability to create/negotiate lond connections (done).
1.7 foxr 37: # - Add general logic for dispatching requests and timeouts. (done).
38: # - Add support for the lonc/lond requests. (done).
1.1 foxr 39: # - Add logging/status monitoring.
40: # - Add Signal handling - HUP restarts. USR1 status report.
1.7 foxr 41: # - Add Configuration file I/O (done).
1.1 foxr 42: # - Add management/status request interface.
1.8 foxr 43: # - Add deferred request capability. (done)
1.9 foxr 44: # - Detect transmission timeouts.
1.7 foxr 45: #
46:
47: # Change log:
1.8 foxr 48: # $Log: loncnew,v $
1.12 foxr 49: # Revision 1.11 2003/06/25 01:54:44 foxr
50: # Fix more problems with transaction failure.
51: #
1.11 foxr 52: # Revision 1.10 2003/06/24 02:46:04 foxr
53: # Put a limit on the number of times we'll retry a connection.
54: # Start getting the signal stuff put in as well...note that need to get signals
55: # going or else 6the client will permanently give up on dead servers.
56: #
1.10 foxr 57: # Revision 1.9 2003/06/13 02:38:43 foxr
58: # Add logging in 'expected format'
59: #
1.9 foxr 60: # Revision 1.8 2003/06/11 02:04:35 foxr
61: # Support delayed transactions... this is done uniformly by encapsulating
62: # transactions in an object ... a LondTransaction that is implemented by
63: # LondTransaction.pm
64: #
1.8 foxr 65: # Revision 1.7 2003/06/03 01:59:39 foxr
66: # complete coding to support deferred transactions.
67: #
1.7 foxr 68: #
1.1 foxr 69:
70: use lib "/home/httpd/lib/perl/";
71: use lib "/home/foxr/newloncapa/types";
72: use Event qw(:DEFAULT );
73: use POSIX qw(:signal_h);
1.12 foxr 74: use POSIX;
1.1 foxr 75: use IO::Socket;
76: use IO::Socket::INET;
77: use IO::Socket::UNIX;
1.9 foxr 78: use IO::File;
1.6 foxr 79: use IO::Handle;
1.1 foxr 80: use Socket;
81: use Crypt::IDEA;
82: use LONCAPA::Queue;
83: use LONCAPA::Stack;
84: use LONCAPA::LondConnection;
1.7 foxr 85: use LONCAPA::LondTransaction;
1.1 foxr 86: use LONCAPA::Configuration;
87: use LONCAPA::HashIterator;
88:
89:
90: #
91: # Disable all signals we might receive from outside for now.
92: #
93: $SIG{QUIT} = IGNORE;
94: $SIG{HUP} = IGNORE;
95: $SIG{USR1} = IGNORE;
96: $SIG{INT} = IGNORE;
97: $SIG{CHLD} = IGNORE;
98: $SIG{__DIE__} = IGNORE;
99:
100:
101: # Read the httpd configuration file to get perl variables
102: # normally set in apache modules:
103:
104: my $perlvarref = LONCAPA::Configuration::read_conf('loncapa.conf');
105: my %perlvar = %{$perlvarref};
106:
107: #
108: # parent and shared variables.
109:
110: my %ChildHash; # by pid -> host.
111:
112:
1.9 foxr 113: my $MaxConnectionCount = 10; # Will get from config later.
1.1 foxr 114: my $ClientConnection = 0; # Uniquifier for client events.
115:
1.9 foxr 116: my $DebugLevel = 0;
1.1 foxr 117: my $IdleTimeout= 3600; # Wait an hour before pruning connections.
118:
119: #
120: # The variables below are only used by the child processes.
121: #
122: my $RemoteHost; # Name of host child is talking to.
123: my $UnixSocketDir= "/home/httpd/sockets";
124: my $IdleConnections = Stack->new(); # Set of idle connections
125: my %ActiveConnections; # Connections to the remote lond.
1.7 foxr 126: my %ActiveTransactions; # LondTransactions in flight.
1.1 foxr 127: my %ActiveClients; # Serial numbers of active clients by socket.
128: my $WorkQueue = Queue->new(); # Queue of pending transactions.
129: my $ConnectionCount = 0;
1.4 foxr 130: my $IdleSeconds = 0; # Number of seconds idle.
1.9 foxr 131: my $Status = ""; # Current status string.
1.10 foxr 132: my $ConnectionRetries=5; # Number of connection retries allowed.
133: my $ConnectionRetriesLeft=5; # Number of connection retries remaining.
1.1 foxr 134:
135: #
1.9 foxr 136: # The hash below gives the HTML format for log messages
137: # given a severity.
138: #
139: my %LogFormats;
140:
141: $LogFormats{"CRITICAL"} = "<font color=red>CRITICAL: %s</font>";
142: $LogFormats{"SUCCESS"} = "<font color=green>SUCCESS: %s</font>";
143: $LogFormats{"INFO"} = "<font color=yellow>INFO: %s</font>";
144: $LogFormats{"WARNING"} = "<font color=blue>WARNING: %s</font>";
145: $LogFormats{"DEFAULT"} = " %s ";
146:
1.10 foxr 147:
148:
149: =pod
150:
151: =head2 LogPerm
152:
153: Makes an entry into the permanent log file.
154:
155: =cut
156: sub LogPerm {
157: my $message=shift;
158: my $execdir=$perlvar{'lonDaemons'};
159: my $now=time;
160: my $local=localtime($now);
161: my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
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 {
187: my $severity = shift;
188: my $message = shift;
189:
190: if(!$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] ";
201: my $finalformat = $finalformat.$format."\n";
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);
208: print $fh $msg;
209:
1.10 foxr 210:
1.9 foxr 211: }
1.6 foxr 212:
1.3 albertel 213:
1.1 foxr 214: =pod
1.3 albertel 215:
216: =head2 GetPeerName
217:
218: Returns the name of the host that a socket object is connected to.
219:
1.1 foxr 220: =cut
221:
222: sub GetPeername {
223: my $connection = shift;
224: my $AdrFamily = shift;
225: my $peer = $connection->peername();
226: my $peerport;
227: my $peerip;
228: if($AdrFamily == AF_INET) {
229: ($peerport, $peerip) = sockaddr_in($peer);
230: my $peername = gethostbyaddr($iaddr, $AdrFamily);
231: return $peername;
232: } elsif ($AdrFamily == AF_UNIX) {
233: my $peerfile;
234: ($peerfile) = sockaddr_un($peer);
235: return $peerfile;
236: }
237: }
238: #----------------------------- Timer management ------------------------
239: =pod
1.3 albertel 240:
1.1 foxr 241: =head2 Debug
1.3 albertel 242:
243: Invoked to issue a debug message.
244:
1.1 foxr 245: =cut
1.3 albertel 246:
1.1 foxr 247: sub Debug {
248: my $level = shift;
249: my $message = shift;
250: if ($level <= $DebugLevel) {
251: print $message." host = ".$RemoteHost."\n";
252: }
253: }
254:
255: sub SocketDump {
256: my $level = shift;
257: my $socket= shift;
258: if($level <= $DebugLevel) {
259: $socket->Dump();
260: }
261: }
1.3 albertel 262:
1.1 foxr 263: =pod
1.3 albertel 264:
1.5 foxr 265: =head2 ShowStatus
266:
267: Place some text as our pid status.
1.10 foxr 268: and as what we return in a SIGUSR1
1.5 foxr 269:
270: =cut
271: sub ShowStatus {
1.10 foxr 272: my $state = shift;
273: my $now = time;
274: my $local = localtime($now);
275: $Status = $local.": ".$state;
276: $0='lonc: '.$state.' '.$local;
1.5 foxr 277: }
278:
279: =pod
280:
1.1 foxr 281: =head2 Tick
1.3 albertel 282:
283: Invoked each timer tick.
284:
1.1 foxr 285: =cut
286:
1.5 foxr 287:
1.1 foxr 288: sub Tick {
289: my $client;
1.5 foxr 290: ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount);
1.12 foxr 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...
299: $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: }
1.5 foxr 305:
306: # Do we have work in the queue, but no connections to service them?
307: # If so, try to make some new connections to get things going again.
308: #
309:
310: my $Requests = $WorkQueue->Count();
1.10 foxr 311: if (($ConnectionCount == 0) && ($Requests > 0)) {
312: if ($ConnectionRetriesLeft > 0) {
313: my $Connections = ($Requests <= $MaxConnectionCount) ?
314: $Requests : $MaxConnectionCount;
315: Debug(1,"Work but no connections, start ".$Connections." of them");
316: for ($i =0; $i < $Connections; $i++) {
317: MakeLondConnection();
318: }
319: } else {
320: Debug(1,"Work in queue, but gave up on connections..flushing\n");
321: EmptyQueue(); # Connections can't be established.
1.5 foxr 322: }
323:
324: }
1.1 foxr 325: }
326:
327: =pod
1.3 albertel 328:
1.1 foxr 329: =head2 SetupTimer
330:
1.3 albertel 331: Sets up a 1 per sec recurring timer event. The event handler is used to:
1.1 foxr 332:
1.3 albertel 333: =item
334:
335: Trigger timeouts on communications along active sockets.
336:
337: =item
338:
339: Trigger disconnections of idle sockets.
1.1 foxr 340:
341: =cut
342:
343: sub SetupTimer {
344: Debug(6, "SetupTimer");
345: Event->timer(interval => 1, debug => 1, cb => \&Tick );
346: }
1.3 albertel 347:
1.1 foxr 348: =pod
1.3 albertel 349:
1.1 foxr 350: =head2 ServerToIdle
1.3 albertel 351:
352: This function is called when a connection to the server is
353: ready for more work.
354:
355: If there is work in the Work queue the top element is dequeued
1.1 foxr 356: and the connection will start to work on it. If the work queue is
357: empty, the connection is pushed on the idle connection stack where
358: it will either get another work unit, or alternatively, if it sits there
359: long enough, it will be shut down and released.
360:
1.3 albertel 361: =cut
1.1 foxr 362:
363: sub ServerToIdle {
364: my $Socket = shift; # Get the socket.
1.7 foxr 365: delete($ActiveTransactions{$Socket}); # Server has no transaction
1.1 foxr 366:
367: &Debug(6, "Server to idle");
368:
369: # If there's work to do, start the transaction:
370:
1.7 foxr 371: $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
1.1 foxr 372: unless($reqdata eq undef) {
1.7 foxr 373: Debug(9, "Queue gave request data: ".$reqdata->getRequest());
374: &StartRequest($Socket, $reqdata);
1.8 foxr 375:
1.1 foxr 376: } else {
377:
378: # There's no work waiting, so push the server to idle list.
379: &Debug(8, "No new work requests, server connection going idle");
380: $IdleConnections->push($Socket);
381: }
382: }
1.3 albertel 383:
1.1 foxr 384: =pod
1.3 albertel 385:
1.1 foxr 386: =head2 ClientWritable
1.3 albertel 387:
388: Event callback for when a client socket is writable.
389:
390: This callback is established when a transaction reponse is
391: avaiable from lond. The response is forwarded to the unix socket
392: as it becomes writable in this sub.
393:
1.1 foxr 394: Parameters:
395:
1.3 albertel 396: =item Event
397:
398: The event that has been triggered. Event->w->data is
399: the data and Event->w->fd is the socket to write.
1.1 foxr 400:
401: =cut
1.3 albertel 402:
1.1 foxr 403: sub ClientWritable {
404: my $Event = shift;
405: my $Watcher = $Event->w;
406: my $Data = $Watcher->data;
407: my $Socket = $Watcher->fd;
408:
409: # Try to send the data:
410:
411: &Debug(6, "ClientWritable writing".$Data);
412: &Debug(9, "Socket is: ".$Socket);
413:
1.6 foxr 414: if($Socket->connected) {
415: my $result = $Socket->send($Data, 0);
416:
417: # $result undefined: the write failed.
418: # otherwise $result is the number of bytes written.
419: # Remove that preceding string from the data.
420: # If the resulting data is empty, destroy the watcher
421: # and set up a read event handler to accept the next
422: # request.
423:
424: &Debug(9,"Send result is ".$result." Defined: ".defined($result));
425: if(defined($result)) {
426: &Debug(9, "send result was defined");
427: if($result == length($Data)) { # Entire string sent.
428: &Debug(9, "ClientWritable data all written");
429: $Watcher->cancel();
430: #
431: # Set up to read next request from socket:
432:
433: my $descr = sprintf("Connection to lonc client %d",
434: $ActiveClients{$Socket});
435: Event->io(cb => \&ClientRequest,
436: poll => 'r',
437: desc => $descr,
438: data => "",
439: fd => $Socket);
440:
441: } else { # Partial string sent.
442: $Watcher->data(substr($Data, $result));
443: }
444:
445: } else { # Error of some sort...
446:
447: # Some errnos are possible:
448: my $errno = $!;
449: if($errno == POSIX::EWOULDBLOCK ||
450: $errno == POSIX::EAGAIN ||
451: $errno == POSIX::EINTR) {
452: # No action taken?
453: } else { # Unanticipated errno.
454: &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
455: $Watcher->cancel; # Stop the watcher.
456: $Socket->shutdown(2); # Kill connection
457: $Socket->close(); # Close the socket.
458: }
1.1 foxr 459:
460: }
1.6 foxr 461: } else {
462: $Watcher->cancel(); # A delayed request...just cancel.
1.1 foxr 463: }
464: }
465:
466: =pod
1.3 albertel 467:
1.1 foxr 468: =head2 CompleteTransaction
1.3 albertel 469:
470: Called when the reply data has been received for a lond
1.1 foxr 471: transaction. The reply data must now be sent to the
472: ultimate client on the other end of the Unix socket. This is
473: done by setting up a writable event for the socket with the
474: data the reply data.
1.3 albertel 475:
1.1 foxr 476: Parameters:
1.3 albertel 477:
478: =item Socket
479:
480: Socket on which the lond transaction occured. This is a
481: LondConnection. The data received is in the TransactionReply member.
482:
1.7 foxr 483: =item Transaction
1.3 albertel 484:
1.7 foxr 485: The transaction that is being completed.
1.1 foxr 486:
487: =cut
1.3 albertel 488:
1.1 foxr 489: sub CompleteTransaction {
490: &Debug(6,"Complete transaction");
491: my $Socket = shift;
1.7 foxr 492: my $Transaction = shift;
1.1 foxr 493:
1.7 foxr 494: if (!$Transaction->isDeferred()) { # Normal transaction
495: my $data = $Socket->GetReply(); # Data to send.
496: StartClientReply($Transaction, $data);
497: } else { # Delete deferred transaction file.
1.9 foxr 498: Log("SUCCESS", "A delayed transaction was completed");
1.10 foxr 499: LogPerm("S:$Client:".$Transaction->getRequest());
1.7 foxr 500: unlink $Transaction->getFile();
501: }
1.6 foxr 502: }
503: =pod
504: =head1 StartClientReply
505:
506: Initiates a reply to a client where the reply data is a parameter.
507:
1.7 foxr 508: =head2 parameters:
509:
510: =item Transaction
511:
512: The transaction for which we are responding to the client.
513:
514: =item data
515:
516: The data to send to apached client.
517:
1.6 foxr 518: =cut
519: sub StartClientReply {
1.7 foxr 520: my $Transaction = shift;
1.6 foxr 521: my $data = shift;
1.1 foxr 522:
1.12 foxr 523:
1.7 foxr 524: my $Client = $Transaction->getClient();
525:
1.1 foxr 526: &Debug(8," Reply was: ".$data);
527: my $Serial = $ActiveClients{$Client};
528: my $desc = sprintf("Connection to lonc client %d",
1.6 foxr 529:
1.1 foxr 530: $Serial);
531: Event->io(fd => $Client,
532: poll => "w",
533: desc => $desc,
534: cb => \&ClientWritable,
535: data => $data);
536: }
1.4 foxr 537: =pod
538: =head2 FailTransaction
539:
540: Finishes a transaction with failure because the associated lond socket
1.7 foxr 541: disconnected. There are two possibilities:
542: - The transaction is deferred: in which case we just quietly
543: delete the transaction since there is no client connection.
544: - The transaction is 'live' in which case we initiate the sending
545: of "con_lost" to the client.
546:
547: Deleting the transaction means killing it from the
548: %ActiveTransactions hash.
1.4 foxr 549:
550: Parameters:
551:
552: =item client
553:
1.7 foxr 554: The LondTransaction we are failing.
555:
1.4 foxr 556: =cut
557:
558: sub FailTransaction {
1.7 foxr 559: my $transaction = shift;
1.10 foxr 560: Debug(1, "Failing transaction: ".$transaction->getRequest());
561: if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
1.11 foxr 562: my $client = $transaction->getClient();
1.10 foxr 563: Debug(1," Replying con_lost to ".$transaction->getRequest());
1.11 foxr 564: StartClientReply($transaction, "con_lost\n");
1.7 foxr 565: }
1.4 foxr 566:
567: }
568:
569: =pod
1.6 foxr 570: =head1 EmptyQueue
1.7 foxr 571:
1.6 foxr 572: Fails all items in the work queue with con_lost.
1.7 foxr 573: Note that each item in the work queue is a transaction.
574:
1.6 foxr 575: =cut
576: sub EmptyQueue {
577: while($WorkQueue->Count()) {
1.10 foxr 578: my $request = $WorkQueue->dequeue(); # This is a transaction
1.7 foxr 579: FailTransaction($request);
1.6 foxr 580: }
581: }
582:
583: =pod
1.4 foxr 584:
1.9 foxr 585: =head2 CloseAllLondConnections
586:
587: Close all connections open on lond prior to exit e.g.
588:
589: =cut
590: sub CloseAllLondConnections {
591: foreach $Socket (keys %ActiveConnections) {
592: KillSocket($Socket);
593: }
594: }
595: =cut
596:
597: =pod
598:
1.4 foxr 599: =head2 KillSocket
600:
601: Destroys a socket. This function can be called either when a socket
602: has died of 'natural' causes or because a socket needs to be pruned due to
603: idleness. If the socket has died naturally, if there are no longer any
604: live connections a new connection is created (in case there are transactions
605: in the queue). If the socket has been pruned, it is never re-created.
606:
607: Parameters:
1.1 foxr 608:
1.4 foxr 609: =item Socket
610:
611: The socket to kill off.
612:
613: =item Restart
614:
615: nonzero if we are allowed to create a new connection.
616:
617:
618: =cut
619: sub KillSocket {
620: my $Socket = shift;
621:
1.9 foxr 622: $Socket->Shutdown();
623:
1.7 foxr 624: # If the socket came from the active connection set,
625: # delete its transaction... note that FailTransaction should
626: # already have been called!!!
627: # otherwise it came from the idle set.
628: #
1.4 foxr 629:
630: if(exists($ActiveTransactions{$Socket})) {
631: delete ($ActiveTransactions{$Socket});
632: }
633: if(exists($ActiveConnections{$Socket})) {
634: delete($ActiveConnections{$Socket});
635: }
636: $ConnectionCount--;
1.6 foxr 637:
638: # If the connection count has gone to zero and there is work in the
639: # work queue, the work all gets failed with con_lost.
640: #
641: if($ConnectionCount == 0) {
642: EmptyQueue;
1.4 foxr 643: }
644: }
1.1 foxr 645:
646: =pod
1.3 albertel 647:
1.1 foxr 648: =head2 LondReadable
1.3 albertel 649:
1.1 foxr 650: This function is called whenever a lond connection
651: is readable. The action is state dependent:
652:
1.3 albertel 653: =head3 State=Initialized
654:
655: We''re waiting for the challenge, this is a no-op until the
1.1 foxr 656: state changes.
1.3 albertel 657:
1.1 foxr 658: =head3 State=Challenged
1.3 albertel 659:
660: The challenge has arrived we need to transition to Writable.
1.1 foxr 661: The connection must echo the challenge back.
1.3 albertel 662:
1.1 foxr 663: =head3 State=ChallengeReplied
1.3 albertel 664:
665: The challenge has been replied to. The we are receiveing the
1.1 foxr 666: 'ok' from the partner.
1.3 albertel 667:
1.1 foxr 668: =head3 State=RequestingKey
1.3 albertel 669:
670: The ok has been received and we need to send the request for
1.1 foxr 671: an encryption key. Transition to writable for that.
1.3 albertel 672:
1.1 foxr 673: =head3 State=ReceivingKey
1.3 albertel 674:
675: The the key has been requested, now we are reading the new key.
676:
1.1 foxr 677: =head3 State=Idle
1.3 albertel 678:
679: The encryption key has been negotiated or we have finished
1.1 foxr 680: reading data from the a transaction. If the callback data has
681: a client as well as the socket iformation, then we are
682: doing a transaction and the data received is relayed to the client
683: before the socket is put on the idle list.
1.3 albertel 684:
1.1 foxr 685: =head3 State=SendingRequest
1.3 albertel 686:
687: I do not think this state can be received here, but if it is,
1.1 foxr 688: the appropriate thing to do is to transition to writable, and send
689: the request.
1.3 albertel 690:
1.1 foxr 691: =head3 State=ReceivingReply
1.3 albertel 692:
693: We finished sending the request to the server and now transition
1.1 foxr 694: to readable to receive the reply.
695:
696: The parameter to this function are:
1.3 albertel 697:
1.1 foxr 698: The event. Implicit in this is the watcher and its data. The data
699: contains at least the lond connection object and, if a
700: transaction is in progress, the socket attached to the local client.
701:
1.3 albertel 702: =cut
1.1 foxr 703:
704: sub LondReadable {
1.8 foxr 705:
1.1 foxr 706: my $Event = shift;
707: my $Watcher = $Event->w;
708: my $Socket = $Watcher->data;
709: my $client = undef;
710:
1.8 foxr 711: &Debug(6,"LondReadable called state = ".$State);
712:
1.1 foxr 713:
714: my $State = $Socket->GetState(); # All action depends on the state.
715:
716: SocketDump(6, $Socket);
1.12 foxr 717: my $status = $Socket->Readable();
718: &Debug(2, "Socket->Readable returned: $status");
1.1 foxr 719:
1.12 foxr 720: if($status != 0) {
1.4 foxr 721: # bad return from socket read. Currently this means that
722: # The socket has become disconnected. We fail the transaction.
723:
724: if(exists($ActiveTransactions{$Socket})) {
725: Debug(3,"Lond connection lost failing transaction");
726: FailTransaction($ActiveTransactions{$Socket});
727: }
728: $Watcher->cancel();
1.6 foxr 729: KillSocket($Socket);
1.4 foxr 730: return;
1.1 foxr 731: }
732: SocketDump(6,$Socket);
733:
734: $State = $Socket->GetState(); # Update in case of transition.
735: &Debug(6, "After read, state is ".$State);
736:
737: if($State eq "Initialized") {
738:
739:
740: } elsif ($State eq "ChallengeReceived") {
741: # The challenge must be echoed back; The state machine
742: # in the connection takes care of setting that up. Just
743: # need to transition to writable:
744:
1.8 foxr 745: $Watcher->cb(\&LondWritable);
1.1 foxr 746: $Watcher->poll("w");
747:
748: } elsif ($State eq "ChallengeReplied") {
749:
750:
751: } elsif ($State eq "RequestingKey") {
752: # The ok was received. Now we need to request the key
753: # That requires us to be writable:
754:
1.8 foxr 755: $Watcher->cb(\&LondWritable);
1.1 foxr 756: $Watcher->poll("w");
757:
758: } elsif ($State eq "ReceivingKey") {
759:
760: } elsif ($State eq "Idle") {
761: # If necessary, complete a transaction and then go into the
762: # idle queue.
1.8 foxr 763: $Watcher->cancel();
1.1 foxr 764: if(exists($ActiveTransactions{$Socket})) {
765: Debug(8,"Completing transaction!!");
766: CompleteTransaction($Socket,
767: $ActiveTransactions{$Socket});
1.9 foxr 768: } else {
769: Log("SUCCESS", "Connection ".$ConnectionCount." to "
770: .$RemoteHost." now ready for action");
1.1 foxr 771: }
772: ServerToIdle($Socket); # Next work unit or idle.
1.6 foxr 773:
1.1 foxr 774: } elsif ($State eq "SendingRequest") {
775: # We need to be writable for this and probably don't belong
776: # here inthe first place.
777:
778: Deubg(6, "SendingRequest state encountered in readable");
779: $Watcher->poll("w");
780: $Watcher->cb(\&LondWritable);
781:
782: } elsif ($State eq "ReceivingReply") {
783:
784:
785: } else {
786: # Invalid state.
787: Debug(4, "Invalid state in LondReadable");
788: }
789: }
1.3 albertel 790:
1.1 foxr 791: =pod
1.3 albertel 792:
1.1 foxr 793: =head2 LondWritable
1.3 albertel 794:
1.1 foxr 795: This function is called whenever a lond connection
796: becomes writable while there is a writeable monitoring
797: event. The action taken is very state dependent:
1.3 albertel 798:
1.1 foxr 799: =head3 State = Connected
1.3 albertel 800:
801: The connection is in the process of sending the 'init' hailing to the
802: lond on the remote end. The connection object''s Writable member is
803: called. On error, ConnectionError is called to destroy the connection
804: and remove it from the ActiveConnections hash
805:
1.1 foxr 806: =head3 Initialized
1.3 albertel 807:
808: 'init' has been sent, writability monitoring is removed and
809: readability monitoring is started with LondReadable as the callback.
810:
1.1 foxr 811: =head3 ChallengeReceived
1.3 albertel 812:
813: The connection has received the who are you challenge from the remote
814: system, and is in the process of sending the challenge
815: response. Writable is called.
816:
1.1 foxr 817: =head3 ChallengeReplied
1.3 albertel 818:
819: The connection has replied to the initial challenge The we switch to
820: monitoring readability looking for the server to reply with 'ok'.
821:
1.1 foxr 822: =head3 RequestingKey
1.3 albertel 823:
824: The connection is in the process of requesting its encryption key.
825: Writable is called.
826:
1.1 foxr 827: =head3 ReceivingKey
1.3 albertel 828:
829: The connection has sent the request for a key. Switch to readability
830: monitoring to accept the key
831:
1.1 foxr 832: =head3 SendingRequest
1.3 albertel 833:
834: The connection is in the process of sending a request to the server.
835: This request is part of a client transaction. All the states until
836: now represent the client setup protocol. Writable is called.
837:
1.1 foxr 838: =head3 ReceivingReply
839:
1.3 albertel 840: The connection has sent a request. Now it must receive a reply.
841: Readability monitoring is requested.
842:
843: This function is an event handler and therefore receives as
1.1 foxr 844: a parameter the event that has fired. The data for the watcher
845: of this event is a reference to a list of one or two elements,
846: depending on state. The first (and possibly only) element is the
847: socket. The second (present only if a request is in progress)
848: is the socket on which to return a reply to the caller.
849:
850: =cut
1.3 albertel 851:
1.1 foxr 852: sub LondWritable {
853: my $Event = shift;
854: my $Watcher = $Event->w;
1.8 foxr 855: my $Socket = $Watcher->data;
856: my $State = $Socket->GetState();
1.1 foxr 857:
1.8 foxr 858: Debug(6,"LondWritable State = ".$State."\n");
1.1 foxr 859:
1.8 foxr 860:
1.1 foxr 861: # Figure out what to do depending on the state of the socket:
862:
863:
864:
865:
866: SocketDump(6,$Socket);
867:
868: if ($State eq "Connected") {
869:
870: if ($Socket->Writable() != 0) {
871: # The write resulted in an error.
1.4 foxr 872: # We'll treat this as if the socket got disconnected:
1.9 foxr 873: Log("WARNING", "Connection to ".$RemoteHost.
874: " has been disconnected");
1.4 foxr 875: $Watcher->cancel();
1.6 foxr 876: KillSocket($Socket);
1.4 foxr 877: return;
1.1 foxr 878: }
1.4 foxr 879: # "init" is being sent...
880:
1.1 foxr 881:
882: } elsif ($State eq "Initialized") {
883:
884: # Now that init was sent, we switch
885: # to watching for readability:
886:
1.8 foxr 887: $Watcher->cb(\&LondReadable);
1.1 foxr 888: $Watcher->poll("r");
889:
890: } elsif ($State eq "ChallengeReceived") {
891: # We received the challenge, now we
892: # are echoing it back. This is a no-op,
893: # we're waiting for the state to change
894:
895: if($Socket->Writable() != 0) {
1.5 foxr 896:
897: $Watcher->cancel();
1.6 foxr 898: KillSocket($Socket);
1.5 foxr 899: return;
1.1 foxr 900: }
901:
902: } elsif ($State eq "ChallengeReplied") {
903: # The echo was sent back, so we switch
904: # to watching readability.
905:
1.8 foxr 906: $Watcher->cb(\&LondReadable);
1.1 foxr 907: $Watcher->poll("r");
908:
909: } elsif ($State eq "RequestingKey") {
910: # At this time we're requesting the key.
911: # again, this is essentially a no-op.
912: # we'll write the next chunk until the
913: # state changes.
914:
915: if($Socket->Writable() != 0) {
916: # Write resulted in an error.
1.5 foxr 917:
918: $Watcher->cancel();
1.6 foxr 919: KillSocket($Socket);
1.5 foxr 920: return;
921:
1.1 foxr 922: }
923: } elsif ($State eq "ReceivingKey") {
924: # Now we need to wait for the key
925: # to come back from the peer:
926:
1.8 foxr 927: $Watcher->cb(\&LondReadable);
1.1 foxr 928: $Watcher->poll("r");
929:
930: } elsif ($State eq "SendingRequest") {
931: # At this time we are sending a request to the
932: # peer... write the next chunk:
933:
934: if($Socket->Writable() != 0) {
935:
1.5 foxr 936: if(exists($ActiveTransactions{$Socket})) {
937: Debug(3, "Lond connection lost, failing transactions");
938: FailTransaction($ActiveTransactions{$Socket});
939: }
940: $Watcher->cancel();
1.6 foxr 941: KillSocket($Socket);
1.5 foxr 942: return;
943:
1.1 foxr 944: }
945:
946: } elsif ($State eq "ReceivingReply") {
947: # The send has completed. Wait for the
948: # data to come in for a reply.
949: Debug(8,"Writable sent request/receiving reply");
1.8 foxr 950: $Watcher->cb(\&LondReadable);
1.1 foxr 951: $Watcher->poll("r");
952:
953: } else {
954: # Control only passes here on an error:
955: # the socket state does not match any
956: # of the known states... so an error
957: # must be logged.
958:
959: &Debug(4, "Invalid socket state ".$State."\n");
960: }
961:
962: }
1.6 foxr 963: =pod
964:
965: =cut
966: sub QueueDelayed {
1.8 foxr 967: Debug(3,"QueueDelayed called");
968:
1.6 foxr 969: my $path = "$perlvar{'lonSockDir'}/delayed";
1.8 foxr 970:
971: Debug(4, "Delayed path: ".$path);
1.6 foxr 972: opendir(DIRHANDLE, $path);
1.8 foxr 973:
1.6 foxr 974: @alldelayed = grep /\.$RemoteHost$/, readdir DIRHANDLE;
1.8 foxr 975: Debug(4, "Got ".$alldelayed." delayed files");
1.6 foxr 976: closedir(DIRHANDLE);
977: my $dfname;
1.8 foxr 978: my $reqfile;
979: foreach $dfname (sort @alldelayed) {
980: $reqfile = "$path/$dfname";
981: Debug(4, "queueing ".$reqfile);
1.6 foxr 982: my $Handle = IO::File->new($reqfile);
983: my $cmd = <$Handle>;
1.8 foxr 984: chomp $cmd; # There may or may not be a newline...
1.12 foxr 985: $cmd = $cmd."\n"; # now for sure there's exactly one newline.
1.7 foxr 986: my $Transaction = LondTransaction->new($cmd);
987: $Transaction->SetDeferred($reqfile);
988: QueueTransaction($Transaction);
1.6 foxr 989: }
990:
991: }
1.1 foxr 992:
993: =pod
1.3 albertel 994:
1.1 foxr 995: =head2 MakeLondConnection
1.3 albertel 996:
997: Create a new lond connection object, and start it towards its initial
998: idleness. Once idle, it becomes elligible to receive transactions
999: from the work queue. If the work queue is not empty when the
1000: connection is completed and becomes idle, it will dequeue an entry and
1001: start off on it.
1002:
1.1 foxr 1003: =cut
1.3 albertel 1004:
1.1 foxr 1005: sub MakeLondConnection {
1006: Debug(4,"MakeLondConnection to ".GetServerHost()." on port "
1007: .GetServerPort());
1008:
1009: my $Connection = LondConnection->new(&GetServerHost(),
1010: &GetServerPort());
1011:
1012: if($Connection == undef) { # Needs to be more robust later.
1.9 foxr 1013: Log("CRITICAL","Failed to make a connection with lond.");
1.10 foxr 1014: $ConnectionRetriesLeft--;
1015: return 0; # Failure.
1.5 foxr 1016: } else {
1.10 foxr 1017: $ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
1.5 foxr 1018: # The connection needs to have writability
1019: # monitored in order to send the init sequence
1020: # that starts the whole authentication/key
1021: # exchange underway.
1022: #
1023: my $Socket = $Connection->GetSocket();
1024: if($Socket == undef) {
1025: die "did not get a socket from the connection";
1026: } else {
1027: &Debug(9,"MakeLondConnection got socket: ".$Socket);
1028: }
1.1 foxr 1029:
1.5 foxr 1030:
1031: $event = Event->io(fd => $Socket,
1032: poll => 'w',
1033: cb => \&LondWritable,
1.8 foxr 1034: data => $Connection,
1.5 foxr 1035: desc => 'Connection to lond server');
1036: $ActiveConnections{$Connection} = $event;
1037:
1038: $ConnectionCount++;
1.8 foxr 1039: Debug(4, "Connection count = ".$ConnectionCount);
1.6 foxr 1040: if($ConnectionCount == 1) { # First Connection:
1041: QueueDelayed;
1042: }
1.9 foxr 1043: Log("SUCESS", "Created connection ".$ConnectionCount
1044: ." to host ".GetServerHost());
1.10 foxr 1045: return 1; # Return success.
1.1 foxr 1046: }
1047:
1048: }
1.3 albertel 1049:
1.1 foxr 1050: =pod
1.3 albertel 1051:
1.1 foxr 1052: =head2 StartRequest
1.3 albertel 1053:
1054: Starts a lond request going on a specified lond connection.
1055: parameters are:
1056:
1057: =item $Lond
1058:
1059: Connection to the lond that will send the transaction and receive the
1060: reply.
1061:
1062: =item $Client
1063:
1064: Connection to the client that is making this request We got the
1065: request from this socket, and when the request has been relayed to
1066: lond and we get a reply back from lond it will get sent to this
1067: socket.
1068:
1069: =item $Request
1070:
1071: The text of the request to send.
1072:
1.1 foxr 1073: =cut
1074:
1075: sub StartRequest {
1076: my $Lond = shift;
1.7 foxr 1077: my $Request = shift; # This is a LondTransaction.
1.1 foxr 1078:
1.7 foxr 1079: Debug(6, "StartRequest: ".$Request->getRequest());
1.1 foxr 1080:
1081: my $Socket = $Lond->GetSocket();
1082:
1.7 foxr 1083: $Request->Activate($Lond);
1084: $ActiveTransactions{$Lond} = $Request;
1.1 foxr 1085:
1.7 foxr 1086: $Lond->InitiateTransaction($Request->getRequest());
1.8 foxr 1087: $event = Event->io(fd => $Socket,
1.1 foxr 1088: poll => "w",
1089: cb => \&LondWritable,
1090: data => $Lond,
1091: desc => "lond transaction connection");
1092: $ActiveConnections{$Lond} = $event;
1093: Debug(8," Start Request made watcher data with ".$event->data."\n");
1094: }
1095:
1096: =pod
1.3 albertel 1097:
1.1 foxr 1098: =head2 QueueTransaction
1.3 albertel 1099:
1100: If there is an idle lond connection, it is put to work doing this
1101: transaction. Otherwise, the transaction is placed in the work queue.
1102: If placed in the work queue and the maximum number of connections has
1103: not yet been created, a new connection will be started. Our goal is
1104: to eventually have a sufficient number of connections that the work
1105: queue will typically be empty. parameters are:
1106:
1107: =item Socket
1108:
1109: open on the lonc client.
1110:
1111: =item Request
1112:
1113: data to send to the lond.
1.1 foxr 1114:
1115: =cut
1.3 albertel 1116:
1.1 foxr 1117: sub QueueTransaction {
1118:
1.7 foxr 1119: my $requestData = shift; # This is a LondTransaction.
1120: my $cmd = $requestData->getRequest();
1121:
1122: Debug(6,"QueueTransaction: ".$cmd);
1.1 foxr 1123:
1124: my $LondSocket = $IdleConnections->pop();
1125: if(!defined $LondSocket) { # Need to queue request.
1126: Debug(8,"Must queue...");
1127: $WorkQueue->enqueue($requestData);
1128: if($ConnectionCount < $MaxConnectionCount) {
1129: Debug(4,"Starting additional lond connection");
1130: MakeLondConnection();
1131: }
1132: } else { # Can start the request:
1133: Debug(8,"Can start...");
1.7 foxr 1134: StartRequest($LondSocket, $requestData);
1.1 foxr 1135: }
1136: }
1137:
1138: #-------------------------- Lonc UNIX socket handling ---------------------
1.3 albertel 1139:
1.1 foxr 1140: =pod
1.3 albertel 1141:
1.1 foxr 1142: =head2 ClientRequest
1.3 albertel 1143: Callback that is called when data can be read from the UNIX domain
1144: socket connecting us with an apache server process.
1.1 foxr 1145:
1146: =cut
1147:
1148: sub ClientRequest {
1149: Debug(6, "ClientRequest");
1150: my $event = shift;
1151: my $watcher = $event->w;
1152: my $socket = $watcher->fd;
1153: my $data = $watcher->data;
1154: my $thisread;
1155:
1156: Debug(9, " Watcher named: ".$watcher->desc);
1157:
1158: my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
1159: Debug(8, "rcv: data length = ".length($thisread)
1160: ." read =".$thisread);
1161: unless (defined $rv && length($thisread)) {
1162: # Likely eof on socket.
1163: Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
1164: close($socket);
1165: $watcher->cancel();
1166: delete($ActiveClients{$socket});
1.10 foxr 1167: return;
1.1 foxr 1168: }
1169: Debug(8,"Data: ".$data." this read: ".$thisread);
1170: $data = $data.$thisread; # Append new data.
1171: $watcher->data($data);
1172: if($data =~ /(.*\n)/) { # Request entirely read.
1.10 foxr 1173: if($data eq "close_connection_exit\n") {
1.9 foxr 1174: Log("CRITICAL",
1175: "Request Close Connection ... exiting");
1176: CloseAllLondConnections();
1177: exit;
1178: }
1.1 foxr 1179: Debug(8, "Complete transaction received: ".$data);
1.8 foxr 1180: my $Transaction = LondTransaction->new($data);
1.7 foxr 1181: $Transaction->SetClient($socket);
1182: QueueTransaction($Transaction);
1.1 foxr 1183: $watcher->cancel(); # Done looking for input data.
1184: }
1185:
1186: }
1187:
1188:
1189: =pod
1.3 albertel 1190:
1.1 foxr 1191: =head2 NewClient
1.3 albertel 1192:
1193: Callback that is called when a connection is received on the unix
1194: socket for a new client of lonc. The callback is parameterized by the
1195: event.. which is a-priori assumed to be an io event, and therefore has
1196: an fd member that is the Listener socket. We Accept the connection
1197: and register a new event on the readability of that socket:
1198:
1.1 foxr 1199: =cut
1.3 albertel 1200:
1.1 foxr 1201: sub NewClient {
1202: Debug(6, "NewClient");
1203: my $event = shift; # Get the event parameters.
1204: my $watcher = $event->w;
1205: my $socket = $watcher->fd; # Get the event' socket.
1206: my $connection = $socket->accept(); # Accept the client connection.
1207: Debug(8,"Connection request accepted from "
1208: .GetPeername($connection, AF_UNIX));
1209:
1210:
1211: my $description = sprintf("Connection to lonc client %d",
1212: $ClientConnection);
1213: Debug(9, "Creating event named: ".$description);
1214: Event->io(cb => \&ClientRequest,
1215: poll => 'r',
1216: desc => $description,
1217: data => "",
1218: fd => $connection);
1219: $ActiveClients{$connection} = $ClientConnection;
1220: $ClientConnection++;
1221: }
1.3 albertel 1222:
1223: =pod
1224:
1225: =head2 GetLoncSocketPath
1226:
1227: Returns the name of the UNIX socket on which to listen for client
1228: connections.
1.1 foxr 1229:
1230: =cut
1.3 albertel 1231:
1.1 foxr 1232: sub GetLoncSocketPath {
1233: return $UnixSocketDir."/".GetServerHost();
1234: }
1235:
1.3 albertel 1236: =pod
1237:
1238: =head2 GetServerHost
1239:
1240: Returns the host whose lond we talk with.
1241:
1.1 foxr 1242: =cut
1.3 albertel 1243:
1.7 foxr 1244: sub GetServerHost {
1.1 foxr 1245: return $RemoteHost; # Setup by the fork.
1246: }
1.3 albertel 1247:
1248: =pod
1249:
1250: =head2 GetServerPort
1251:
1252: Returns the lond port number.
1253:
1.1 foxr 1254: =cut
1.3 albertel 1255:
1.7 foxr 1256: sub GetServerPort {
1.1 foxr 1257: return $perlvar{londPort};
1258: }
1.3 albertel 1259:
1260: =pod
1261:
1262: =head2 SetupLoncListener
1263:
1264: Setup a lonc listener event. The event is called when the socket
1265: becomes readable.. that corresponds to the receipt of a new
1266: connection. The event handler established will accept the connection
1267: (creating a communcations channel), that int turn will establish
1268: another event handler to subess requests.
1.1 foxr 1269:
1270: =cut
1.3 albertel 1271:
1.1 foxr 1272: sub SetupLoncListener {
1273:
1274: my $socket;
1275: my $SocketName = GetLoncSocketPath();
1276: unlink($SocketName);
1.7 foxr 1277: unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,
1.1 foxr 1278: Listen => 10,
1279: Type => SOCK_STREAM)) {
1280: die "Failed to create a lonc listner socket";
1281: }
1282: Event->io(cb => \&NewClient,
1283: poll => 'r',
1284: desc => 'Lonc listener Unix Socket',
1285: fd => $socket);
1286: }
1287:
1288: =pod
1.3 albertel 1289:
1.10 foxr 1290: =head2 SignalledToDeath
1291:
1292: Called in response to a signal that causes a chid process to die.
1293:
1294: =cut
1295:
1296:
1297: sub SignalledToDeath {
1.12 foxr 1298: Debug(2,"Signalled to death!");
1.10 foxr 1299: my ($signal) = @_;
1300: chomp($signal);
1301: Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "
1302: ."died through "."\"$signal\"");
1303: LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
1304: ."\"$signal\"");
1305: die("Signal abnormal end");
1.12 foxr 1306: exit 0;
1.10 foxr 1307:
1308: }
1.1 foxr 1309: =head2 ChildProcess
1310:
1311: This sub implements a child process for a single lonc daemon.
1312:
1313: =cut
1314:
1315: sub ChildProcess {
1316:
1317:
1318: # For now turn off signals.
1319:
1.10 foxr 1320: $SIG{QUIT} = \&SignalledToDeath;
1.1 foxr 1321: $SIG{HUP} = IGNORE;
1322: $SIG{USR1} = IGNORE;
1.12 foxr 1323: $SIG{INT} = DEFAULT;
1.1 foxr 1324: $SIG{CHLD} = IGNORE;
1.10 foxr 1325: $SIG{__DIE__} = \&SignalledToDeath;
1.1 foxr 1326:
1327: SetupTimer();
1328:
1329: SetupLoncListener();
1330:
1331: $Event::Debuglevel = $DebugLevel;
1332:
1333: Debug(9, "Making initial lond connection for ".$RemoteHost);
1334:
1335: # Setup the initial server connection:
1336:
1.10 foxr 1337: # &MakeLondConnection(); // let first work requirest do it.
1338:
1.5 foxr 1339:
1.1 foxr 1340: Debug(9,"Entering event loop");
1341: my $ret = Event::loop(); # Start the main event loop.
1342:
1343:
1344: die "Main event loop exited!!!";
1345: }
1346:
1347: # Create a new child for host passed in:
1348:
1349: sub CreateChild {
1.12 foxr 1350: my $sigset = POSIX::SigSet->new(SIGINT);
1351: sigprocmask(SIG_BLOCK, $sigset);
1.1 foxr 1352: my $host = shift;
1353: $RemoteHost = $host;
1.9 foxr 1354: Log("CRITICAL", "Forking server for ".$host);
1.1 foxr 1355: $pid = fork;
1356: if($pid) { # Parent
1357: $ChildHash{$pid} = $RemoteHost;
1.12 foxr 1358: sigprocmask(SIG_UNBLOCK, $sigset);
1359:
1.1 foxr 1360: } else { # child.
1.5 foxr 1361: ShowStatus("Connected to ".$RemoteHost);
1.12 foxr 1362: $SIG{INT} = DEFAULT;
1363: sigprocmask(SIG_UNBLOCK, $sigset);
1364: ChildProcess; # Does not return.
1.1 foxr 1365: }
1366:
1367: }
1368: #
1369: # Parent process logic pass 1:
1370: # For each entry in the hosts table, we will
1371: # fork off an instance of ChildProcess to service the transactions
1372: # to that host. Each pid will be entered in a global hash
1373: # with the value of the key, the host.
1374: # The parent will then enter a loop to wait for process exits.
1375: # Each exit gets logged and the child gets restarted.
1376: #
1377:
1.5 foxr 1378: #
1379: # Fork and start in new session so hang-up isn't going to
1380: # happen without intent.
1381: #
1382:
1383:
1.6 foxr 1384:
1385:
1.8 foxr 1386:
1.6 foxr 1387:
1388: ShowStatus("Forming new session");
1389: my $childpid = fork;
1390: if ($childpid != 0) {
1391: sleep 4; # Give child a chacne to break to
1392: exit 0; # a new sesion.
1393: }
1.8 foxr 1394: #
1395: # Write my pid into the pid file so I can be located
1396: #
1397:
1398: ShowStatus("Parent writing pid file:");
1399: $execdir = $perlvar{'lonDaemons'};
1400: open (PIDSAVE, ">$execdir/logs/lonc.pid");
1401: print PIDSAVE "$$\n";
1402: close(PIDSAVE);
1.6 foxr 1403:
1404: if (POSIX::setsid() < 0) {
1405: print "Could not create new session\n";
1406: exit -1;
1407: }
1.5 foxr 1408:
1409: ShowStatus("Forking node servers");
1410:
1.9 foxr 1411: Log("CRITICAL", "--------------- Starting children ---------------");
1412:
1.1 foxr 1413: my $HostIterator = LondConnection::GetHostIterator;
1414: while (! $HostIterator->end()) {
1415:
1416: $hostentryref = $HostIterator->get();
1417: CreateChild($hostentryref->[0]);
1418: $HostIterator->next();
1419: }
1.12 foxr 1420: $RemoteHost = "Parent Server";
1.1 foxr 1421:
1422: # Maintain the population:
1.5 foxr 1423:
1424: ShowStatus("Parent keeping the flock");
1.1 foxr 1425:
1.10 foxr 1426: #
1427: # Set up parent signals:
1428: #
1.12 foxr 1429:
1430: $SIG{INT} = \&KillThemAll;
1431: $SIG{TERM} = \&KillThemAll;
1.13 ! foxr 1432: $SIG{HUP} = \&Restart;
1.10 foxr 1433:
1.1 foxr 1434: while(1) {
1435: $deadchild = wait();
1436: if(exists $ChildHash{$deadchild}) { # need to restart.
1437: $deadhost = $ChildHash{$deadchild};
1438: delete($ChildHash{$deadchild});
1.9 foxr 1439: Log("WARNING","Lost child pid= ".$deadchild.
1.1 foxr 1440: "Connected to host ".$deadhost);
1.9 foxr 1441: Log("INFO", "Restarting child procesing ".$deadhost);
1.1 foxr 1442: CreateChild($deadhost);
1443: }
1.13 ! foxr 1444: }
! 1445:
! 1446: =pod
! 1447:
! 1448: =head1 Restart
! 1449:
! 1450: Signal handler for HUP... all children are killed and
! 1451: we self restart. This is an el-cheapo way to re read
! 1452: the config file.
! 1453:
! 1454: =cut
! 1455:
! 1456: sub Restart {
! 1457: KillThemAll; # First kill all the children.
! 1458: Log("CRITICAL", "Restarting");
! 1459: my $execdir = $perlvar{'lonDaemons'};
! 1460: unlink("$execdir/logs/lonc.pid");
! 1461: exec("$execdir/lonc");
1.10 foxr 1462: }
1.12 foxr 1463:
1464: =pod
1465:
1466: =head1 KillThemAll
1467:
1468: Signal handler that kills all children by sending them a
1469: SIGINT. Responds to sigint and sigterm.
1470:
1471: =cut
1472:
1.10 foxr 1473: sub KillThemAll {
1.12 foxr 1474: Debug(2, "Kill them all!!");
1475: local($SIG{CHLD}) = 'IGNORE'; # Our children >will< die.
1476: foreach $pid (keys %ChildHash) {
1477: my $serving = $ChildHash{$pid};
1478: Debug(2, "Killing lonc for $serving pid = $pid");
1479: ShowStatus("Killing lonc for $serving pid = $pid");
1480: Log("CRITICAL", "Killing lonc for $serving pid = $pid");
1481: kill('INT', $pid);
1482: }
1483: Log("CRITICAL", "Killing the master process.");
1484: exit
1.1 foxr 1485: }
1.12 foxr 1486:
1487: =pod
1.1 foxr 1488:
1489: =head1 Theory
1.3 albertel 1490:
1491: The event class is used to build this as a single process with an
1492: event driven model. The following events are handled:
1.1 foxr 1493:
1494: =item UNIX Socket connection Received
1495:
1496: =item Request data arrives on UNIX data transfer socket.
1497:
1498: =item lond connection becomes writable.
1499:
1500: =item timer fires at 1 second intervals.
1501:
1502: All sockets are run in non-blocking mode. Timeouts managed by the timer
1503: handler prevents hung connections.
1504:
1505: Key data structures:
1506:
1.3 albertel 1507: =item RequestQueue
1508:
1509: A queue of requests received from UNIX sockets that are
1510: waiting for a chance to be forwarded on a lond connection socket.
1511:
1512: =item ActiveConnections
1513:
1514: A hash of lond connections that have transactions in process that are
1515: available to be timed out.
1516:
1517: =item ActiveTransactions
1518:
1519: A hash indexed by lond connections that contain the client reply
1520: socket for each connection that has an active transaction on it.
1521:
1522: =item IdleConnections
1523:
1524: A hash of lond connections that have no work to do. These connections
1525: can be closed if they are idle for a long enough time.
1.1 foxr 1526:
1527: =cut
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