Annotation of loncom/loncnew, revision 1.38
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: #
1.38 ! foxr 5: # $Id: loncnew,v 1.37 2003/12/16 16:12:19 albertel Exp $
1.2 albertel 6: #
7: # Copyright Michigan State University Board of Trustees
8: #
9: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
1.17 foxr 10: ## LON-CAPA is free software; you can redistribute it and/or modify
1.2 albertel 11: # it under the terms of the GNU General Public License as published by
12: # the Free Software Foundation; either version 2 of the License, or
13: # (at your option) any later version.
14: #
15: # LON-CAPA is distributed in the hope that it will be useful,
16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18: # GNU General Public License for more details.
19: #
20: # You should have received a copy of the GNU General Public License
21: # along with LON-CAPA; if not, write to the Free Software
22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23: #
24: # /home/httpd/html/adm/gpl.txt
25: #
26: # http://www.lon-capa.org/
27: #
1.1 foxr 28: #
1.15 foxr 29: # new lonc handles n request out bver m connections to londs.
1.1 foxr 30: # This module is based on the Event class.
31: # Development iterations:
32: # - Setup basic event loop. (done)
33: # - Add timer dispatch. (done)
34: # - Add ability to accept lonc UNIX domain sockets. (done)
35: # - Add ability to create/negotiate lond connections (done).
1.7 foxr 36: # - Add general logic for dispatching requests and timeouts. (done).
37: # - Add support for the lonc/lond requests. (done).
1.38 ! foxr 38: # - Add logging/status monitoring. (done)
! 39: # - Add Signal handling - HUP restarts. USR1 status report. (done)
1.7 foxr 40: # - Add Configuration file I/O (done).
1.38 ! foxr 41: # - Add management/status request interface. (done)
1.8 foxr 42: # - Add deferred request capability. (done)
1.38 ! foxr 43: # - Detect transmission timeouts. (done)
1.7 foxr 44: #
45:
1.23 foxr 46: use strict;
1.1 foxr 47: use lib "/home/httpd/lib/perl/";
48: use Event qw(:DEFAULT );
49: use POSIX qw(:signal_h);
1.12 foxr 50: use POSIX;
1.1 foxr 51: use IO::Socket;
52: use IO::Socket::INET;
53: use IO::Socket::UNIX;
1.9 foxr 54: use IO::File;
1.6 foxr 55: use IO::Handle;
1.1 foxr 56: use Socket;
57: use Crypt::IDEA;
58: use LONCAPA::Queue;
59: use LONCAPA::Stack;
60: use LONCAPA::LondConnection;
1.7 foxr 61: use LONCAPA::LondTransaction;
1.1 foxr 62: use LONCAPA::Configuration;
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:
92: #
93: # The variables below are only used by the child processes.
94: #
95: my $RemoteHost; # Name of host child is talking to.
1.20 albertel 96: my $UnixSocketDir= $perlvar{'lonSockDir'};
1.1 foxr 97: my $IdleConnections = Stack->new(); # Set of idle connections
98: my %ActiveConnections; # Connections to the remote lond.
1.7 foxr 99: my %ActiveTransactions; # LondTransactions in flight.
1.1 foxr 100: my %ActiveClients; # Serial numbers of active clients by socket.
101: my $WorkQueue = Queue->new(); # Queue of pending transactions.
102: my $ConnectionCount = 0;
1.4 foxr 103: my $IdleSeconds = 0; # Number of seconds idle.
1.9 foxr 104: my $Status = ""; # Current status string.
1.14 foxr 105: my $RecentLogEntry = "";
1.30 foxr 106: my $ConnectionRetries=2; # Number of connection retries allowed.
107: my $ConnectionRetriesLeft=2; # Number of connection retries remaining.
1.1 foxr 108:
109: #
1.9 foxr 110: # The hash below gives the HTML format for log messages
111: # given a severity.
112: #
113: my %LogFormats;
114:
115: $LogFormats{"CRITICAL"} = "<font color=red>CRITICAL: %s</font>";
116: $LogFormats{"SUCCESS"} = "<font color=green>SUCCESS: %s</font>";
117: $LogFormats{"INFO"} = "<font color=yellow>INFO: %s</font>";
118: $LogFormats{"WARNING"} = "<font color=blue>WARNING: %s</font>";
119: $LogFormats{"DEFAULT"} = " %s ";
120:
1.10 foxr 121:
122:
123: =pod
124:
125: =head2 LogPerm
126:
127: Makes an entry into the permanent log file.
128:
129: =cut
130: sub LogPerm {
131: my $message=shift;
132: my $execdir=$perlvar{'lonDaemons'};
133: my $now=time;
134: my $local=localtime($now);
135: my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
136: print $fh "$now:$message:$local\n";
137: }
1.9 foxr 138:
139: =pod
140:
141: =head2 Log
142:
143: Logs a message to the log file.
144: Parameters:
145:
146: =item severity
147:
148: One of CRITICAL, WARNING, INFO, SUCCESS used to select the
149: format string used to format the message. if the severity is
150: not a defined severity the Default format string is used.
151:
152: =item message
153:
154: The base message. In addtion to the format string, the message
155: will be appended to a string containing the name of our remote
156: host and the time will be formatted into the message.
157:
158: =cut
159:
160: sub Log {
161: my $severity = shift;
162: my $message = shift;
163:
164: if(!$LogFormats{$severity}) {
165: $severity = "DEFAULT";
166: }
167:
168: my $format = $LogFormats{$severity};
169:
170: # Put the window dressing in in front of the message format:
171:
172: my $now = time;
173: my $local = localtime($now);
174: my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
175: my $finalformat = $finalformat.$format."\n";
176:
177: # open the file and put the result.
178:
179: my $execdir = $perlvar{'lonDaemons'};
180: my $fh = IO::File->new(">>$execdir/logs/lonc.log");
181: my $msg = sprintf($finalformat, $message);
1.14 foxr 182: $RecentLogEntry = $msg;
1.9 foxr 183: print $fh $msg;
184:
1.10 foxr 185:
1.9 foxr 186: }
1.6 foxr 187:
1.3 albertel 188:
1.1 foxr 189: =pod
1.3 albertel 190:
191: =head2 GetPeerName
192:
193: Returns the name of the host that a socket object is connected to.
194:
1.1 foxr 195: =cut
196:
197: sub GetPeername {
198: my $connection = shift;
199: my $AdrFamily = shift;
200: my $peer = $connection->peername();
201: my $peerport;
202: my $peerip;
203: if($AdrFamily == AF_INET) {
204: ($peerport, $peerip) = sockaddr_in($peer);
1.23 foxr 205: my $peername = gethostbyaddr($peerip, $AdrFamily);
1.1 foxr 206: return $peername;
207: } elsif ($AdrFamily == AF_UNIX) {
208: my $peerfile;
209: ($peerfile) = sockaddr_un($peer);
210: return $peerfile;
211: }
212: }
213: =pod
1.3 albertel 214:
1.1 foxr 215: =head2 Debug
1.3 albertel 216:
217: Invoked to issue a debug message.
218:
1.1 foxr 219: =cut
1.3 albertel 220:
1.1 foxr 221: sub Debug {
222: my $level = shift;
223: my $message = shift;
224: if ($level <= $DebugLevel) {
1.23 foxr 225: Log("INFO", "-Debug- $message host = $RemoteHost");
1.1 foxr 226: }
227: }
228:
229: sub SocketDump {
230: my $level = shift;
231: my $socket= shift;
232: if($level <= $DebugLevel) {
233: $socket->Dump();
234: }
235: }
1.3 albertel 236:
1.1 foxr 237: =pod
1.3 albertel 238:
1.5 foxr 239: =head2 ShowStatus
240:
241: Place some text as our pid status.
1.10 foxr 242: and as what we return in a SIGUSR1
1.5 foxr 243:
244: =cut
245: sub ShowStatus {
1.10 foxr 246: my $state = shift;
247: my $now = time;
248: my $local = localtime($now);
249: $Status = $local.": ".$state;
250: $0='lonc: '.$state.' '.$local;
1.5 foxr 251: }
252:
253: =pod
254:
1.15 foxr 255: =head 2 SocketTimeout
256:
257: Called when an action on the socket times out. The socket is
258: destroyed and any active transaction is failed.
259:
260:
261: =cut
262: sub SocketTimeout {
263: my $Socket = shift;
1.38 ! foxr 264: Log("WARNING", "A socket timeout was detected");
! 265: Debug(0, " SocketTimeout called: ");
! 266: $Socket->Dump();
1.22 foxr 267: KillSocket($Socket); # A transaction timeout also counts as
268: # a connection failure:
269: $ConnectionRetriesLeft--;
1.15 foxr 270: }
1.35 foxr 271: #----------------------------- Timer management ------------------------
1.15 foxr 272:
273: =pod
274:
1.1 foxr 275: =head2 Tick
1.3 albertel 276:
277: Invoked each timer tick.
278:
1.1 foxr 279: =cut
280:
1.5 foxr 281:
1.1 foxr 282: sub Tick {
283: my $client;
1.22 foxr 284: if($ConnectionRetriesLeft > 0) {
285: ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
286: ." Retries remaining: ".$ConnectionRetriesLeft);
287: } else {
288: ShowStatus(GetServerHost()." >> DEAD <<");
289: }
1.4 foxr 290: # Is it time to prune connection count:
291:
292:
293: if($IdleConnections->Count() &&
294: ($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
295: $IdleSeconds++;
296: if($IdleSeconds > $IdleTimeout) { # Prune a connection...
1.23 foxr 297: my $Socket = $IdleConnections->pop();
1.6 foxr 298: KillSocket($Socket);
1.4 foxr 299: }
300: } else {
301: $IdleSeconds = 0; # Reset idle count if not idle.
302: }
1.15 foxr 303: #
304: # For each inflight transaction, tick down its timeout counter.
305: #
1.35 foxr 306:
1.34 albertel 307: foreach my $item (keys %ActiveConnections) {
308: my $State = $ActiveConnections{$item}->data->GetState();
1.35 foxr 309: if ($State ne 'Idle') {
1.34 albertel 310: Debug(5,"Ticking Socket $State $item");
311: $ActiveConnections{$item}->data->Tick();
312: }
1.15 foxr 313: }
1.5 foxr 314: # Do we have work in the queue, but no connections to service them?
315: # If so, try to make some new connections to get things going again.
316: #
317:
318: my $Requests = $WorkQueue->Count();
1.10 foxr 319: if (($ConnectionCount == 0) && ($Requests > 0)) {
320: if ($ConnectionRetriesLeft > 0) {
321: my $Connections = ($Requests <= $MaxConnectionCount) ?
322: $Requests : $MaxConnectionCount;
1.29 foxr 323: Debug(5,"Work but no connections, start ".$Connections." of them");
1.22 foxr 324: my $successCount = 0;
1.23 foxr 325: for (my $i =0; $i < $Connections; $i++) {
1.22 foxr 326: $successCount += MakeLondConnection();
327: }
328: if($successCount == 0) { # All connections failed:
1.29 foxr 329: Debug(5,"Work in queue failed to make any connectiouns\n");
1.22 foxr 330: EmptyQueue(); # Fail pending transactions with con_lost.
1.10 foxr 331: }
332: } else {
1.22 foxr 333: ShowStatus(GetServerHost()." >>> DEAD!!! <<<");
1.29 foxr 334: Debug(5,"Work in queue, but gave up on connections..flushing\n");
1.10 foxr 335: EmptyQueue(); # Connections can't be established.
1.5 foxr 336: }
337:
338: }
1.1 foxr 339: }
340:
341: =pod
1.3 albertel 342:
1.1 foxr 343: =head2 SetupTimer
344:
1.3 albertel 345: Sets up a 1 per sec recurring timer event. The event handler is used to:
1.1 foxr 346:
1.3 albertel 347: =item
348:
349: Trigger timeouts on communications along active sockets.
350:
351: =item
352:
353: Trigger disconnections of idle sockets.
1.1 foxr 354:
355: =cut
356:
357: sub SetupTimer {
358: Debug(6, "SetupTimer");
1.33 foxr 359: Event->timer(interval => 1, cb => \&Tick );
1.1 foxr 360: }
1.3 albertel 361:
1.1 foxr 362: =pod
1.3 albertel 363:
1.1 foxr 364: =head2 ServerToIdle
1.3 albertel 365:
366: This function is called when a connection to the server is
367: ready for more work.
368:
369: If there is work in the Work queue the top element is dequeued
1.1 foxr 370: and the connection will start to work on it. If the work queue is
371: empty, the connection is pushed on the idle connection stack where
372: it will either get another work unit, or alternatively, if it sits there
373: long enough, it will be shut down and released.
374:
1.3 albertel 375: =cut
1.1 foxr 376:
377: sub ServerToIdle {
378: my $Socket = shift; # Get the socket.
1.7 foxr 379: delete($ActiveTransactions{$Socket}); # Server has no transaction
1.1 foxr 380:
1.29 foxr 381: &Debug(5, "Server to idle");
1.1 foxr 382:
383: # If there's work to do, start the transaction:
384:
1.23 foxr 385: my $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
1.29 foxr 386: if ($reqdata ne undef) {
387: Debug(5, "Queue gave request data: ".$reqdata->getRequest());
1.7 foxr 388: &StartRequest($Socket, $reqdata);
1.8 foxr 389:
1.1 foxr 390: } else {
391:
392: # There's no work waiting, so push the server to idle list.
1.29 foxr 393: &Debug(5, "No new work requests, server connection going idle");
1.1 foxr 394: $IdleConnections->push($Socket);
395: }
396: }
1.3 albertel 397:
1.1 foxr 398: =pod
1.3 albertel 399:
1.1 foxr 400: =head2 ClientWritable
1.3 albertel 401:
402: Event callback for when a client socket is writable.
403:
404: This callback is established when a transaction reponse is
405: avaiable from lond. The response is forwarded to the unix socket
406: as it becomes writable in this sub.
407:
1.1 foxr 408: Parameters:
409:
1.3 albertel 410: =item Event
411:
412: The event that has been triggered. Event->w->data is
413: the data and Event->w->fd is the socket to write.
1.1 foxr 414:
415: =cut
1.3 albertel 416:
1.1 foxr 417: sub ClientWritable {
418: my $Event = shift;
419: my $Watcher = $Event->w;
420: my $Data = $Watcher->data;
421: my $Socket = $Watcher->fd;
422:
423: # Try to send the data:
424:
425: &Debug(6, "ClientWritable writing".$Data);
426: &Debug(9, "Socket is: ".$Socket);
427:
1.6 foxr 428: if($Socket->connected) {
429: my $result = $Socket->send($Data, 0);
430:
431: # $result undefined: the write failed.
432: # otherwise $result is the number of bytes written.
433: # Remove that preceding string from the data.
434: # If the resulting data is empty, destroy the watcher
435: # and set up a read event handler to accept the next
436: # request.
437:
438: &Debug(9,"Send result is ".$result." Defined: ".defined($result));
1.29 foxr 439: if($result ne undef) {
1.6 foxr 440: &Debug(9, "send result was defined");
441: if($result == length($Data)) { # Entire string sent.
442: &Debug(9, "ClientWritable data all written");
443: $Watcher->cancel();
444: #
445: # Set up to read next request from socket:
446:
447: my $descr = sprintf("Connection to lonc client %d",
448: $ActiveClients{$Socket});
449: Event->io(cb => \&ClientRequest,
450: poll => 'r',
451: desc => $descr,
452: data => "",
453: fd => $Socket);
454:
455: } else { # Partial string sent.
456: $Watcher->data(substr($Data, $result));
1.15 foxr 457: if($result == 0) { # client hung up on us!!
458: Log("INFO", "lonc pipe client hung up on us!");
459: $Watcher->cancel;
460: $Socket->shutdown(2);
461: $Socket->close();
462: }
1.6 foxr 463: }
464:
465: } else { # Error of some sort...
466:
467: # Some errnos are possible:
468: my $errno = $!;
469: if($errno == POSIX::EWOULDBLOCK ||
470: $errno == POSIX::EAGAIN ||
471: $errno == POSIX::EINTR) {
472: # No action taken?
473: } else { # Unanticipated errno.
474: &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
475: $Watcher->cancel; # Stop the watcher.
476: $Socket->shutdown(2); # Kill connection
477: $Socket->close(); # Close the socket.
478: }
1.1 foxr 479:
480: }
1.6 foxr 481: } else {
482: $Watcher->cancel(); # A delayed request...just cancel.
1.1 foxr 483: }
484: }
485:
486: =pod
1.3 albertel 487:
1.1 foxr 488: =head2 CompleteTransaction
1.3 albertel 489:
490: Called when the reply data has been received for a lond
1.1 foxr 491: transaction. The reply data must now be sent to the
492: ultimate client on the other end of the Unix socket. This is
493: done by setting up a writable event for the socket with the
494: data the reply data.
1.3 albertel 495:
1.1 foxr 496: Parameters:
1.3 albertel 497:
498: =item Socket
499:
500: Socket on which the lond transaction occured. This is a
501: LondConnection. The data received is in the TransactionReply member.
502:
1.7 foxr 503: =item Transaction
1.3 albertel 504:
1.7 foxr 505: The transaction that is being completed.
1.1 foxr 506:
507: =cut
1.3 albertel 508:
1.1 foxr 509: sub CompleteTransaction {
1.29 foxr 510: &Debug(5,"Complete transaction");
1.1 foxr 511: my $Socket = shift;
1.7 foxr 512: my $Transaction = shift;
1.1 foxr 513:
1.7 foxr 514: if (!$Transaction->isDeferred()) { # Normal transaction
515: my $data = $Socket->GetReply(); # Data to send.
516: StartClientReply($Transaction, $data);
517: } else { # Delete deferred transaction file.
1.9 foxr 518: Log("SUCCESS", "A delayed transaction was completed");
1.23 foxr 519: LogPerm("S:$Transaction->getClient() :".$Transaction->getRequest());
1.7 foxr 520: unlink $Transaction->getFile();
521: }
1.6 foxr 522: }
523: =pod
524: =head1 StartClientReply
525:
526: Initiates a reply to a client where the reply data is a parameter.
527:
1.7 foxr 528: =head2 parameters:
529:
530: =item Transaction
531:
532: The transaction for which we are responding to the client.
533:
534: =item data
535:
536: The data to send to apached client.
537:
1.6 foxr 538: =cut
539: sub StartClientReply {
1.7 foxr 540: my $Transaction = shift;
1.6 foxr 541: my $data = shift;
1.1 foxr 542:
1.12 foxr 543:
1.7 foxr 544: my $Client = $Transaction->getClient();
545:
1.1 foxr 546: &Debug(8," Reply was: ".$data);
547: my $Serial = $ActiveClients{$Client};
548: my $desc = sprintf("Connection to lonc client %d",
549: $Serial);
550: Event->io(fd => $Client,
551: poll => "w",
552: desc => $desc,
553: cb => \&ClientWritable,
554: data => $data);
555: }
1.4 foxr 556: =pod
557: =head2 FailTransaction
558:
559: Finishes a transaction with failure because the associated lond socket
1.7 foxr 560: disconnected. There are two possibilities:
561: - The transaction is deferred: in which case we just quietly
562: delete the transaction since there is no client connection.
563: - The transaction is 'live' in which case we initiate the sending
564: of "con_lost" to the client.
565:
566: Deleting the transaction means killing it from the
567: %ActiveTransactions hash.
1.4 foxr 568:
569: Parameters:
570:
571: =item client
572:
1.7 foxr 573: The LondTransaction we are failing.
574:
1.4 foxr 575: =cut
576:
577: sub FailTransaction {
1.7 foxr 578: my $transaction = shift;
1.17 foxr 579: Log("WARNING", "Failing transaction ".$transaction->getRequest());
1.30 foxr 580: Debug(1, "Failing transaction: ".$transaction->getRequest());
1.10 foxr 581: if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
1.11 foxr 582: my $client = $transaction->getClient();
1.30 foxr 583: Debug(1," Replying con_lost to ".$transaction->getRequest());
1.11 foxr 584: StartClientReply($transaction, "con_lost\n");
1.7 foxr 585: }
1.22 foxr 586: if($ConnectionRetriesLeft <= 0) {
587: Log("CRITICAL", "Host marked dead: ".GetServerHost());
588: }
1.4 foxr 589:
590: }
591:
592: =pod
1.6 foxr 593: =head1 EmptyQueue
1.7 foxr 594:
1.6 foxr 595: Fails all items in the work queue with con_lost.
1.7 foxr 596: Note that each item in the work queue is a transaction.
597:
1.6 foxr 598: =cut
599: sub EmptyQueue {
1.22 foxr 600: $ConnectionRetriesLeft--; # Counts as connection failure too.
1.6 foxr 601: while($WorkQueue->Count()) {
1.10 foxr 602: my $request = $WorkQueue->dequeue(); # This is a transaction
1.7 foxr 603: FailTransaction($request);
1.6 foxr 604: }
605: }
606:
607: =pod
1.4 foxr 608:
1.9 foxr 609: =head2 CloseAllLondConnections
610:
611: Close all connections open on lond prior to exit e.g.
612:
613: =cut
614: sub CloseAllLondConnections {
1.23 foxr 615: foreach my $Socket (keys %ActiveConnections) {
1.9 foxr 616: KillSocket($Socket);
617: }
618: }
619: =cut
620:
621: =pod
622:
1.4 foxr 623: =head2 KillSocket
624:
625: Destroys a socket. This function can be called either when a socket
626: has died of 'natural' causes or because a socket needs to be pruned due to
627: idleness. If the socket has died naturally, if there are no longer any
628: live connections a new connection is created (in case there are transactions
629: in the queue). If the socket has been pruned, it is never re-created.
630:
631: Parameters:
1.1 foxr 632:
1.4 foxr 633: =item Socket
634:
635: The socket to kill off.
636:
637: =item Restart
638:
639: nonzero if we are allowed to create a new connection.
640:
641:
642: =cut
643: sub KillSocket {
644: my $Socket = shift;
645:
1.17 foxr 646: Log("WARNING", "Shutting down a socket");
1.9 foxr 647: $Socket->Shutdown();
648:
1.7 foxr 649: # If the socket came from the active connection set,
650: # delete its transaction... note that FailTransaction should
651: # already have been called!!!
652: # otherwise it came from the idle set.
653: #
1.4 foxr 654:
655: if(exists($ActiveTransactions{$Socket})) {
656: delete ($ActiveTransactions{$Socket});
657: }
658: if(exists($ActiveConnections{$Socket})) {
659: delete($ActiveConnections{$Socket});
1.37 albertel 660: $ConnectionCount--;
661: if ($ConnectionCount < 0) { $ConnectionCount = 0; }
1.4 foxr 662: }
1.6 foxr 663: # If the connection count has gone to zero and there is work in the
664: # work queue, the work all gets failed with con_lost.
665: #
666: if($ConnectionCount == 0) {
1.22 foxr 667: EmptyQueue();
1.4 foxr 668: }
669: }
1.1 foxr 670:
671: =pod
1.3 albertel 672:
1.1 foxr 673: =head2 LondReadable
1.3 albertel 674:
1.1 foxr 675: This function is called whenever a lond connection
676: is readable. The action is state dependent:
677:
1.3 albertel 678: =head3 State=Initialized
679:
680: We''re waiting for the challenge, this is a no-op until the
1.1 foxr 681: state changes.
1.3 albertel 682:
1.1 foxr 683: =head3 State=Challenged
1.3 albertel 684:
685: The challenge has arrived we need to transition to Writable.
1.1 foxr 686: The connection must echo the challenge back.
1.3 albertel 687:
1.1 foxr 688: =head3 State=ChallengeReplied
1.3 albertel 689:
690: The challenge has been replied to. The we are receiveing the
1.1 foxr 691: 'ok' from the partner.
1.3 albertel 692:
1.1 foxr 693: =head3 State=RequestingKey
1.3 albertel 694:
695: The ok has been received and we need to send the request for
1.1 foxr 696: an encryption key. Transition to writable for that.
1.3 albertel 697:
1.1 foxr 698: =head3 State=ReceivingKey
1.3 albertel 699:
700: The the key has been requested, now we are reading the new key.
701:
1.1 foxr 702: =head3 State=Idle
1.3 albertel 703:
704: The encryption key has been negotiated or we have finished
1.1 foxr 705: reading data from the a transaction. If the callback data has
706: a client as well as the socket iformation, then we are
707: doing a transaction and the data received is relayed to the client
708: before the socket is put on the idle list.
1.3 albertel 709:
1.1 foxr 710: =head3 State=SendingRequest
1.3 albertel 711:
712: I do not think this state can be received here, but if it is,
1.1 foxr 713: the appropriate thing to do is to transition to writable, and send
714: the request.
1.3 albertel 715:
1.1 foxr 716: =head3 State=ReceivingReply
1.3 albertel 717:
718: We finished sending the request to the server and now transition
1.1 foxr 719: to readable to receive the reply.
720:
721: The parameter to this function are:
1.3 albertel 722:
1.1 foxr 723: The event. Implicit in this is the watcher and its data. The data
724: contains at least the lond connection object and, if a
725: transaction is in progress, the socket attached to the local client.
726:
1.3 albertel 727: =cut
1.1 foxr 728:
729: sub LondReadable {
1.8 foxr 730:
1.1 foxr 731: my $Event = shift;
732: my $Watcher = $Event->w;
733: my $Socket = $Watcher->data;
734: my $client = undef;
735:
1.23 foxr 736: &Debug(6,"LondReadable called state = ".$Socket->GetState());
1.8 foxr 737:
1.1 foxr 738:
739: my $State = $Socket->GetState(); # All action depends on the state.
740:
741: SocketDump(6, $Socket);
1.12 foxr 742: my $status = $Socket->Readable();
1.17 foxr 743:
1.12 foxr 744: &Debug(2, "Socket->Readable returned: $status");
1.1 foxr 745:
1.12 foxr 746: if($status != 0) {
1.4 foxr 747: # bad return from socket read. Currently this means that
748: # The socket has become disconnected. We fail the transaction.
749:
1.17 foxr 750: Log("WARNING",
751: "Lond connection lost.");
1.4 foxr 752: if(exists($ActiveTransactions{$Socket})) {
753: FailTransaction($ActiveTransactions{$Socket});
754: }
755: $Watcher->cancel();
1.6 foxr 756: KillSocket($Socket);
1.22 foxr 757: $ConnectionRetriesLeft--; # Counts as connection failure
1.4 foxr 758: return;
1.1 foxr 759: }
760: SocketDump(6,$Socket);
761:
762: $State = $Socket->GetState(); # Update in case of transition.
763: &Debug(6, "After read, state is ".$State);
764:
765: if($State eq "Initialized") {
766:
767:
768: } elsif ($State eq "ChallengeReceived") {
769: # The challenge must be echoed back; The state machine
770: # in the connection takes care of setting that up. Just
771: # need to transition to writable:
772:
1.8 foxr 773: $Watcher->cb(\&LondWritable);
1.1 foxr 774: $Watcher->poll("w");
775:
776: } elsif ($State eq "ChallengeReplied") {
777:
778:
779: } elsif ($State eq "RequestingKey") {
780: # The ok was received. Now we need to request the key
781: # That requires us to be writable:
782:
1.8 foxr 783: $Watcher->cb(\&LondWritable);
1.1 foxr 784: $Watcher->poll("w");
785:
786: } elsif ($State eq "ReceivingKey") {
787:
788: } elsif ($State eq "Idle") {
789: # If necessary, complete a transaction and then go into the
790: # idle queue.
1.22 foxr 791: # Note that a trasition to idle indicates a live lond
792: # on the other end so reset the connection retries.
793: #
794: $ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
1.8 foxr 795: $Watcher->cancel();
1.1 foxr 796: if(exists($ActiveTransactions{$Socket})) {
1.29 foxr 797: Debug(5,"Completing transaction!!");
1.1 foxr 798: CompleteTransaction($Socket,
799: $ActiveTransactions{$Socket});
1.9 foxr 800: } else {
801: Log("SUCCESS", "Connection ".$ConnectionCount." to "
802: .$RemoteHost." now ready for action");
1.1 foxr 803: }
804: ServerToIdle($Socket); # Next work unit or idle.
1.6 foxr 805:
1.1 foxr 806: } elsif ($State eq "SendingRequest") {
807: # We need to be writable for this and probably don't belong
808: # here inthe first place.
809:
810: Deubg(6, "SendingRequest state encountered in readable");
811: $Watcher->poll("w");
812: $Watcher->cb(\&LondWritable);
813:
814: } elsif ($State eq "ReceivingReply") {
815:
816:
817: } else {
818: # Invalid state.
819: Debug(4, "Invalid state in LondReadable");
820: }
821: }
1.3 albertel 822:
1.1 foxr 823: =pod
1.3 albertel 824:
1.1 foxr 825: =head2 LondWritable
1.3 albertel 826:
1.1 foxr 827: This function is called whenever a lond connection
828: becomes writable while there is a writeable monitoring
829: event. The action taken is very state dependent:
1.3 albertel 830:
1.1 foxr 831: =head3 State = Connected
1.3 albertel 832:
833: The connection is in the process of sending the 'init' hailing to the
834: lond on the remote end. The connection object''s Writable member is
835: called. On error, ConnectionError is called to destroy the connection
836: and remove it from the ActiveConnections hash
837:
1.1 foxr 838: =head3 Initialized
1.3 albertel 839:
840: 'init' has been sent, writability monitoring is removed and
841: readability monitoring is started with LondReadable as the callback.
842:
1.1 foxr 843: =head3 ChallengeReceived
1.3 albertel 844:
845: The connection has received the who are you challenge from the remote
846: system, and is in the process of sending the challenge
847: response. Writable is called.
848:
1.1 foxr 849: =head3 ChallengeReplied
1.3 albertel 850:
851: The connection has replied to the initial challenge The we switch to
852: monitoring readability looking for the server to reply with 'ok'.
853:
1.1 foxr 854: =head3 RequestingKey
1.3 albertel 855:
856: The connection is in the process of requesting its encryption key.
857: Writable is called.
858:
1.1 foxr 859: =head3 ReceivingKey
1.3 albertel 860:
861: The connection has sent the request for a key. Switch to readability
862: monitoring to accept the key
863:
1.1 foxr 864: =head3 SendingRequest
1.3 albertel 865:
866: The connection is in the process of sending a request to the server.
867: This request is part of a client transaction. All the states until
868: now represent the client setup protocol. Writable is called.
869:
1.1 foxr 870: =head3 ReceivingReply
871:
1.3 albertel 872: The connection has sent a request. Now it must receive a reply.
873: Readability monitoring is requested.
874:
875: This function is an event handler and therefore receives as
1.1 foxr 876: a parameter the event that has fired. The data for the watcher
877: of this event is a reference to a list of one or two elements,
878: depending on state. The first (and possibly only) element is the
879: socket. The second (present only if a request is in progress)
880: is the socket on which to return a reply to the caller.
881:
882: =cut
1.3 albertel 883:
1.1 foxr 884: sub LondWritable {
885: my $Event = shift;
886: my $Watcher = $Event->w;
1.8 foxr 887: my $Socket = $Watcher->data;
888: my $State = $Socket->GetState();
1.1 foxr 889:
1.8 foxr 890: Debug(6,"LondWritable State = ".$State."\n");
1.1 foxr 891:
1.8 foxr 892:
1.1 foxr 893: # Figure out what to do depending on the state of the socket:
894:
895:
896:
897:
898: SocketDump(6,$Socket);
899:
900: if ($State eq "Connected") {
901:
902: if ($Socket->Writable() != 0) {
903: # The write resulted in an error.
1.4 foxr 904: # We'll treat this as if the socket got disconnected:
1.9 foxr 905: Log("WARNING", "Connection to ".$RemoteHost.
906: " has been disconnected");
1.18 foxr 907: FailTransaction($ActiveTransactions{$Socket});
1.4 foxr 908: $Watcher->cancel();
1.6 foxr 909: KillSocket($Socket);
1.4 foxr 910: return;
1.1 foxr 911: }
1.4 foxr 912: # "init" is being sent...
913:
1.1 foxr 914:
915: } elsif ($State eq "Initialized") {
916:
917: # Now that init was sent, we switch
918: # to watching for readability:
919:
1.8 foxr 920: $Watcher->cb(\&LondReadable);
1.1 foxr 921: $Watcher->poll("r");
922:
923: } elsif ($State eq "ChallengeReceived") {
924: # We received the challenge, now we
925: # are echoing it back. This is a no-op,
926: # we're waiting for the state to change
927:
928: if($Socket->Writable() != 0) {
1.5 foxr 929:
930: $Watcher->cancel();
1.6 foxr 931: KillSocket($Socket);
1.5 foxr 932: return;
1.1 foxr 933: }
934:
935: } elsif ($State eq "ChallengeReplied") {
936: # The echo was sent back, so we switch
937: # to watching readability.
938:
1.8 foxr 939: $Watcher->cb(\&LondReadable);
1.1 foxr 940: $Watcher->poll("r");
941:
942: } elsif ($State eq "RequestingKey") {
943: # At this time we're requesting the key.
944: # again, this is essentially a no-op.
945: # we'll write the next chunk until the
946: # state changes.
947:
948: if($Socket->Writable() != 0) {
949: # Write resulted in an error.
1.5 foxr 950:
951: $Watcher->cancel();
1.6 foxr 952: KillSocket($Socket);
1.5 foxr 953: return;
954:
1.1 foxr 955: }
956: } elsif ($State eq "ReceivingKey") {
957: # Now we need to wait for the key
958: # to come back from the peer:
959:
1.8 foxr 960: $Watcher->cb(\&LondReadable);
1.1 foxr 961: $Watcher->poll("r");
962:
963: } elsif ($State eq "SendingRequest") {
964: # At this time we are sending a request to the
965: # peer... write the next chunk:
966:
967: if($Socket->Writable() != 0) {
968:
1.5 foxr 969: if(exists($ActiveTransactions{$Socket})) {
970: Debug(3, "Lond connection lost, failing transactions");
971: FailTransaction($ActiveTransactions{$Socket});
972: }
973: $Watcher->cancel();
1.6 foxr 974: KillSocket($Socket);
1.5 foxr 975: return;
976:
1.1 foxr 977: }
978:
979: } elsif ($State eq "ReceivingReply") {
980: # The send has completed. Wait for the
981: # data to come in for a reply.
982: Debug(8,"Writable sent request/receiving reply");
1.8 foxr 983: $Watcher->cb(\&LondReadable);
1.1 foxr 984: $Watcher->poll("r");
985:
986: } else {
987: # Control only passes here on an error:
988: # the socket state does not match any
989: # of the known states... so an error
990: # must be logged.
991:
992: &Debug(4, "Invalid socket state ".$State."\n");
993: }
994:
995: }
1.6 foxr 996: =pod
997:
998: =cut
999: sub QueueDelayed {
1.8 foxr 1000: Debug(3,"QueueDelayed called");
1001:
1.6 foxr 1002: my $path = "$perlvar{'lonSockDir'}/delayed";
1.8 foxr 1003:
1004: Debug(4, "Delayed path: ".$path);
1.6 foxr 1005: opendir(DIRHANDLE, $path);
1.8 foxr 1006:
1.23 foxr 1007: my @alldelayed = grep /\.$RemoteHost$/, readdir DIRHANDLE;
1.6 foxr 1008: closedir(DIRHANDLE);
1009: my $dfname;
1.8 foxr 1010: my $reqfile;
1011: foreach $dfname (sort @alldelayed) {
1012: $reqfile = "$path/$dfname";
1013: Debug(4, "queueing ".$reqfile);
1.6 foxr 1014: my $Handle = IO::File->new($reqfile);
1015: my $cmd = <$Handle>;
1.8 foxr 1016: chomp $cmd; # There may or may not be a newline...
1.12 foxr 1017: $cmd = $cmd."\n"; # now for sure there's exactly one newline.
1.7 foxr 1018: my $Transaction = LondTransaction->new($cmd);
1019: $Transaction->SetDeferred($reqfile);
1020: QueueTransaction($Transaction);
1.6 foxr 1021: }
1022:
1023: }
1.1 foxr 1024:
1025: =pod
1.3 albertel 1026:
1.1 foxr 1027: =head2 MakeLondConnection
1.3 albertel 1028:
1029: Create a new lond connection object, and start it towards its initial
1030: idleness. Once idle, it becomes elligible to receive transactions
1031: from the work queue. If the work queue is not empty when the
1032: connection is completed and becomes idle, it will dequeue an entry and
1033: start off on it.
1034:
1.1 foxr 1035: =cut
1.3 albertel 1036:
1.1 foxr 1037: sub MakeLondConnection {
1038: Debug(4,"MakeLondConnection to ".GetServerHost()." on port "
1039: .GetServerPort());
1040:
1041: my $Connection = LondConnection->new(&GetServerHost(),
1042: &GetServerPort());
1043:
1.30 foxr 1044: if($Connection eq undef) { # Needs to be more robust later.
1.9 foxr 1045: Log("CRITICAL","Failed to make a connection with lond.");
1.10 foxr 1046: $ConnectionRetriesLeft--;
1047: return 0; # Failure.
1.5 foxr 1048: } else {
1.22 foxr 1049:
1.5 foxr 1050: # The connection needs to have writability
1051: # monitored in order to send the init sequence
1052: # that starts the whole authentication/key
1053: # exchange underway.
1054: #
1055: my $Socket = $Connection->GetSocket();
1.30 foxr 1056: if($Socket eq undef) {
1.5 foxr 1057: die "did not get a socket from the connection";
1058: } else {
1059: &Debug(9,"MakeLondConnection got socket: ".$Socket);
1060: }
1.1 foxr 1061:
1.21 foxr 1062: $Connection->SetTimeoutCallback(\&SocketTimeout);
1063:
1.23 foxr 1064: my $event = Event->io(fd => $Socket,
1.5 foxr 1065: poll => 'w',
1066: cb => \&LondWritable,
1.8 foxr 1067: data => $Connection,
1.5 foxr 1068: desc => 'Connection to lond server');
1069: $ActiveConnections{$Connection} = $event;
1070:
1071: $ConnectionCount++;
1.8 foxr 1072: Debug(4, "Connection count = ".$ConnectionCount);
1.6 foxr 1073: if($ConnectionCount == 1) { # First Connection:
1074: QueueDelayed;
1075: }
1.9 foxr 1076: Log("SUCESS", "Created connection ".$ConnectionCount
1077: ." to host ".GetServerHost());
1.10 foxr 1078: return 1; # Return success.
1.1 foxr 1079: }
1080:
1081: }
1.3 albertel 1082:
1.1 foxr 1083: =pod
1.3 albertel 1084:
1.1 foxr 1085: =head2 StartRequest
1.3 albertel 1086:
1087: Starts a lond request going on a specified lond connection.
1088: parameters are:
1089:
1090: =item $Lond
1091:
1092: Connection to the lond that will send the transaction and receive the
1093: reply.
1094:
1095: =item $Client
1096:
1097: Connection to the client that is making this request We got the
1098: request from this socket, and when the request has been relayed to
1099: lond and we get a reply back from lond it will get sent to this
1100: socket.
1101:
1102: =item $Request
1103:
1104: The text of the request to send.
1105:
1.1 foxr 1106: =cut
1107:
1108: sub StartRequest {
1109: my $Lond = shift;
1.7 foxr 1110: my $Request = shift; # This is a LondTransaction.
1.1 foxr 1111:
1.7 foxr 1112: Debug(6, "StartRequest: ".$Request->getRequest());
1.1 foxr 1113:
1114: my $Socket = $Lond->GetSocket();
1115:
1.7 foxr 1116: $Request->Activate($Lond);
1117: $ActiveTransactions{$Lond} = $Request;
1.1 foxr 1118:
1.7 foxr 1119: $Lond->InitiateTransaction($Request->getRequest());
1.23 foxr 1120: my $event = Event->io(fd => $Socket,
1.1 foxr 1121: poll => "w",
1122: cb => \&LondWritable,
1123: data => $Lond,
1124: desc => "lond transaction connection");
1125: $ActiveConnections{$Lond} = $event;
1126: Debug(8," Start Request made watcher data with ".$event->data."\n");
1127: }
1128:
1129: =pod
1.3 albertel 1130:
1.1 foxr 1131: =head2 QueueTransaction
1.3 albertel 1132:
1133: If there is an idle lond connection, it is put to work doing this
1134: transaction. Otherwise, the transaction is placed in the work queue.
1135: If placed in the work queue and the maximum number of connections has
1136: not yet been created, a new connection will be started. Our goal is
1137: to eventually have a sufficient number of connections that the work
1138: queue will typically be empty. parameters are:
1139:
1140: =item Socket
1141:
1142: open on the lonc client.
1143:
1144: =item Request
1145:
1146: data to send to the lond.
1.1 foxr 1147:
1148: =cut
1.3 albertel 1149:
1.1 foxr 1150: sub QueueTransaction {
1151:
1.7 foxr 1152: my $requestData = shift; # This is a LondTransaction.
1153: my $cmd = $requestData->getRequest();
1154:
1155: Debug(6,"QueueTransaction: ".$cmd);
1.1 foxr 1156:
1157: my $LondSocket = $IdleConnections->pop();
1158: if(!defined $LondSocket) { # Need to queue request.
1.29 foxr 1159: Debug(5,"Must queue...");
1.1 foxr 1160: $WorkQueue->enqueue($requestData);
1161: if($ConnectionCount < $MaxConnectionCount) {
1.22 foxr 1162: if($ConnectionRetriesLeft > 0) {
1.29 foxr 1163: Debug(5,"Starting additional lond connection");
1.22 foxr 1164: if(MakeLondConnection() == 0) {
1165: EmptyQueue(); # Fail transactions, can't make connection.
1166: }
1167: } else {
1168: ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
1169: EmptyQueue(); # It's worse than that ... he's dead Jim.
1.17 foxr 1170: }
1.1 foxr 1171: }
1172: } else { # Can start the request:
1173: Debug(8,"Can start...");
1.7 foxr 1174: StartRequest($LondSocket, $requestData);
1.1 foxr 1175: }
1176: }
1177:
1178: #-------------------------- Lonc UNIX socket handling ---------------------
1.3 albertel 1179:
1.1 foxr 1180: =pod
1.3 albertel 1181:
1.1 foxr 1182: =head2 ClientRequest
1.3 albertel 1183: Callback that is called when data can be read from the UNIX domain
1184: socket connecting us with an apache server process.
1.1 foxr 1185:
1186: =cut
1187:
1188: sub ClientRequest {
1189: Debug(6, "ClientRequest");
1190: my $event = shift;
1191: my $watcher = $event->w;
1192: my $socket = $watcher->fd;
1193: my $data = $watcher->data;
1194: my $thisread;
1195:
1196: Debug(9, " Watcher named: ".$watcher->desc);
1197:
1198: my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
1199: Debug(8, "rcv: data length = ".length($thisread)
1200: ." read =".$thisread);
1.29 foxr 1201: unless (defined $rv && length($thisread)) {
1.1 foxr 1202: # Likely eof on socket.
1203: Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
1204: close($socket);
1205: $watcher->cancel();
1206: delete($ActiveClients{$socket});
1.10 foxr 1207: return;
1.1 foxr 1208: }
1209: Debug(8,"Data: ".$data." this read: ".$thisread);
1210: $data = $data.$thisread; # Append new data.
1211: $watcher->data($data);
1212: if($data =~ /(.*\n)/) { # Request entirely read.
1.10 foxr 1213: if($data eq "close_connection_exit\n") {
1.9 foxr 1214: Log("CRITICAL",
1215: "Request Close Connection ... exiting");
1216: CloseAllLondConnections();
1217: exit;
1218: }
1.1 foxr 1219: Debug(8, "Complete transaction received: ".$data);
1.8 foxr 1220: my $Transaction = LondTransaction->new($data);
1.7 foxr 1221: $Transaction->SetClient($socket);
1222: QueueTransaction($Transaction);
1.1 foxr 1223: $watcher->cancel(); # Done looking for input data.
1224: }
1225:
1226: }
1227:
1228:
1229: =pod
1.3 albertel 1230:
1.1 foxr 1231: =head2 NewClient
1.3 albertel 1232:
1233: Callback that is called when a connection is received on the unix
1234: socket for a new client of lonc. The callback is parameterized by the
1235: event.. which is a-priori assumed to be an io event, and therefore has
1236: an fd member that is the Listener socket. We Accept the connection
1237: and register a new event on the readability of that socket:
1238:
1.1 foxr 1239: =cut
1.3 albertel 1240:
1.1 foxr 1241: sub NewClient {
1242: Debug(6, "NewClient");
1243: my $event = shift; # Get the event parameters.
1244: my $watcher = $event->w;
1245: my $socket = $watcher->fd; # Get the event' socket.
1246: my $connection = $socket->accept(); # Accept the client connection.
1247: Debug(8,"Connection request accepted from "
1248: .GetPeername($connection, AF_UNIX));
1249:
1250:
1251: my $description = sprintf("Connection to lonc client %d",
1252: $ClientConnection);
1253: Debug(9, "Creating event named: ".$description);
1254: Event->io(cb => \&ClientRequest,
1255: poll => 'r',
1256: desc => $description,
1257: data => "",
1258: fd => $connection);
1259: $ActiveClients{$connection} = $ClientConnection;
1260: $ClientConnection++;
1261: }
1.3 albertel 1262:
1263: =pod
1264:
1265: =head2 GetLoncSocketPath
1266:
1267: Returns the name of the UNIX socket on which to listen for client
1268: connections.
1.1 foxr 1269:
1270: =cut
1.3 albertel 1271:
1.1 foxr 1272: sub GetLoncSocketPath {
1273: return $UnixSocketDir."/".GetServerHost();
1274: }
1275:
1.3 albertel 1276: =pod
1277:
1278: =head2 GetServerHost
1279:
1280: Returns the host whose lond we talk with.
1281:
1.1 foxr 1282: =cut
1.3 albertel 1283:
1.7 foxr 1284: sub GetServerHost {
1.1 foxr 1285: return $RemoteHost; # Setup by the fork.
1286: }
1.3 albertel 1287:
1288: =pod
1289:
1290: =head2 GetServerPort
1291:
1292: Returns the lond port number.
1293:
1.1 foxr 1294: =cut
1.3 albertel 1295:
1.7 foxr 1296: sub GetServerPort {
1.1 foxr 1297: return $perlvar{londPort};
1298: }
1.3 albertel 1299:
1300: =pod
1301:
1302: =head2 SetupLoncListener
1303:
1304: Setup a lonc listener event. The event is called when the socket
1305: becomes readable.. that corresponds to the receipt of a new
1306: connection. The event handler established will accept the connection
1307: (creating a communcations channel), that int turn will establish
1308: another event handler to subess requests.
1.1 foxr 1309:
1310: =cut
1.3 albertel 1311:
1.1 foxr 1312: sub SetupLoncListener {
1313:
1314: my $socket;
1315: my $SocketName = GetLoncSocketPath();
1316: unlink($SocketName);
1.7 foxr 1317: unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,
1.1 foxr 1318: Listen => 10,
1319: Type => SOCK_STREAM)) {
1320: die "Failed to create a lonc listner socket";
1321: }
1322: Event->io(cb => \&NewClient,
1323: poll => 'r',
1324: desc => 'Lonc listener Unix Socket',
1325: fd => $socket);
1326: }
1327:
1.14 foxr 1328: =pod
1329:
1330: =head2 ChildStatus
1331:
1332: Child USR1 signal handler to report the most recent status
1333: into the status file.
1334:
1.22 foxr 1335: We also use this to reset the retries count in order to allow the
1336: client to retry connections with a previously dead server.
1.14 foxr 1337: =cut
1338: sub ChildStatus {
1339: my $event = shift;
1340: my $watcher = $event->w;
1341:
1342: Debug(2, "Reporting child status because : ".$watcher->data);
1343: my $docdir = $perlvar{'lonDocRoot'};
1344: my $fh = IO::File->new(">>$docdir/lon-status/loncstatus.txt");
1345: print $fh $$."\t".$RemoteHost."\t".$Status."\t".
1346: $RecentLogEntry."\n";
1.38 ! foxr 1347: #
! 1348: # Write out information about each of the connections:
! 1349: #
! 1350: print $fh "Active connection statuses: \n";
! 1351: my $i = 1;
! 1352: print STDERR "================================= Socket Status Dump:\n";
! 1353: foreach my $item (keys %ActiveConnections) {
! 1354: my $Socket = $ActiveConnections{$item}->data;
! 1355: my $state = $Socket->GetState();
! 1356: print $fh "Connection $i State: $state\n";
! 1357: print STDERR "---------------------- Connection $i \n";
! 1358: $Socket->Dump();
! 1359: $i++;
! 1360: }
1.22 foxr 1361: $ConnectionRetriesLeft = $ConnectionRetries;
1.14 foxr 1362: }
1363:
1.1 foxr 1364: =pod
1.3 albertel 1365:
1.10 foxr 1366: =head2 SignalledToDeath
1367:
1368: Called in response to a signal that causes a chid process to die.
1369:
1370: =cut
1371:
1372:
1373: sub SignalledToDeath {
1.14 foxr 1374: my $event = shift;
1375: my $watcher= $event->w;
1376:
1377: Debug(2,"Signalled to death! via ".$watcher->data);
1.17 foxr 1378: my ($signal) = $watcher->data;
1.10 foxr 1379: chomp($signal);
1380: Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "
1381: ."died through "."\"$signal\"");
1382: LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
1383: ."\"$signal\"");
1.12 foxr 1384: exit 0;
1.10 foxr 1385:
1386: }
1.16 foxr 1387:
1388: =head2 ToggleDebug
1389:
1390: This sub toggles trace debugging on and off.
1391:
1392: =cut
1393:
1394: sub ToggleDebug {
1395: my $Current = $DebugLevel;
1396: $DebugLevel = $NextDebugLevel;
1397: $NextDebugLevel = $Current;
1398:
1399: Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel");
1400:
1401: }
1402:
1.1 foxr 1403: =head2 ChildProcess
1404:
1405: This sub implements a child process for a single lonc daemon.
1406:
1407: =cut
1408:
1409: sub ChildProcess {
1410:
1411:
1.14 foxr 1412: #
1413: # Signals must be handled by the Event framework...
1414: #
1415:
1416: Event->signal(signal => "QUIT",
1417: cb => \&SignalledToDeath,
1418: data => "QUIT");
1419: Event->signal(signal => "HUP",
1420: cb => \&ChildStatus,
1421: data => "HUP");
1422: Event->signal(signal => "USR1",
1423: cb => \&ChildStatus,
1424: data => "USR1");
1.16 foxr 1425: Event->signal(signal => "INT",
1426: cb => \&ToggleDebug,
1427: data => "INT");
1.1 foxr 1428:
1429: SetupTimer();
1430:
1431: SetupLoncListener();
1432:
1433: $Event::Debuglevel = $DebugLevel;
1434:
1435: Debug(9, "Making initial lond connection for ".$RemoteHost);
1436:
1437: # Setup the initial server connection:
1438:
1.14 foxr 1439: # &MakeLondConnection(); // let first work requirest do it.
1.10 foxr 1440:
1.5 foxr 1441:
1.1 foxr 1442: Debug(9,"Entering event loop");
1443: my $ret = Event::loop(); # Start the main event loop.
1444:
1445:
1446: die "Main event loop exited!!!";
1447: }
1448:
1449: # Create a new child for host passed in:
1450:
1451: sub CreateChild {
1.12 foxr 1452: my $sigset = POSIX::SigSet->new(SIGINT);
1453: sigprocmask(SIG_BLOCK, $sigset);
1.1 foxr 1454: my $host = shift;
1455: $RemoteHost = $host;
1.9 foxr 1456: Log("CRITICAL", "Forking server for ".$host);
1.23 foxr 1457: my $pid = fork;
1.1 foxr 1458: if($pid) { # Parent
1.17 foxr 1459: $RemoteHost = "Parent";
1.27 foxr 1460: $ChildHash{$pid} = $host;
1.26 foxr 1461: $HostToPid{$host}= $pid;
1.12 foxr 1462: sigprocmask(SIG_UNBLOCK, $sigset);
1463:
1.1 foxr 1464: } else { # child.
1.5 foxr 1465: ShowStatus("Connected to ".$RemoteHost);
1.23 foxr 1466: $SIG{INT} = 'DEFAULT';
1.12 foxr 1467: sigprocmask(SIG_UNBLOCK, $sigset);
1468: ChildProcess; # Does not return.
1.1 foxr 1469: }
1470:
1471: }
1472: #
1473: # Parent process logic pass 1:
1474: # For each entry in the hosts table, we will
1475: # fork off an instance of ChildProcess to service the transactions
1476: # to that host. Each pid will be entered in a global hash
1477: # with the value of the key, the host.
1478: # The parent will then enter a loop to wait for process exits.
1479: # Each exit gets logged and the child gets restarted.
1480: #
1481:
1.5 foxr 1482: #
1483: # Fork and start in new session so hang-up isn't going to
1484: # happen without intent.
1485: #
1486:
1487:
1.6 foxr 1488:
1489:
1.8 foxr 1490:
1.6 foxr 1491:
1492: ShowStatus("Forming new session");
1493: my $childpid = fork;
1494: if ($childpid != 0) {
1495: sleep 4; # Give child a chacne to break to
1496: exit 0; # a new sesion.
1497: }
1.8 foxr 1498: #
1499: # Write my pid into the pid file so I can be located
1500: #
1501:
1502: ShowStatus("Parent writing pid file:");
1.23 foxr 1503: my $execdir = $perlvar{'lonDaemons'};
1.8 foxr 1504: open (PIDSAVE, ">$execdir/logs/lonc.pid");
1505: print PIDSAVE "$$\n";
1506: close(PIDSAVE);
1.6 foxr 1507:
1.17 foxr 1508:
1509:
1.6 foxr 1510: if (POSIX::setsid() < 0) {
1511: print "Could not create new session\n";
1512: exit -1;
1513: }
1.5 foxr 1514:
1515: ShowStatus("Forking node servers");
1516:
1.9 foxr 1517: Log("CRITICAL", "--------------- Starting children ---------------");
1518:
1.31 foxr 1519: LondConnection::ReadConfig; # Read standard config files.
1.1 foxr 1520: my $HostIterator = LondConnection::GetHostIterator;
1521: while (! $HostIterator->end()) {
1522:
1.23 foxr 1523: my $hostentryref = $HostIterator->get();
1.1 foxr 1524: CreateChild($hostentryref->[0]);
1.26 foxr 1525: $HostHash{$hostentryref->[0]} = $hostentryref->[4];
1.1 foxr 1526: $HostIterator->next();
1527: }
1.12 foxr 1528: $RemoteHost = "Parent Server";
1.1 foxr 1529:
1530: # Maintain the population:
1.5 foxr 1531:
1532: ShowStatus("Parent keeping the flock");
1.1 foxr 1533:
1.10 foxr 1534: #
1535: # Set up parent signals:
1536: #
1.12 foxr 1537:
1.14 foxr 1538: $SIG{INT} = \&Terminate;
1539: $SIG{TERM} = \&Terminate;
1.13 foxr 1540: $SIG{HUP} = \&Restart;
1.14 foxr 1541: $SIG{USR1} = \&CheckKids;
1.24 foxr 1542: $SIG{USR2} = \&UpdateKids; # LonManage update request.
1.10 foxr 1543:
1.1 foxr 1544: while(1) {
1.23 foxr 1545: my $deadchild = wait();
1.1 foxr 1546: if(exists $ChildHash{$deadchild}) { # need to restart.
1.23 foxr 1547: my $deadhost = $ChildHash{$deadchild};
1.26 foxr 1548: delete($HostToPid{$deadhost});
1.1 foxr 1549: delete($ChildHash{$deadchild});
1.9 foxr 1550: Log("WARNING","Lost child pid= ".$deadchild.
1.1 foxr 1551: "Connected to host ".$deadhost);
1.9 foxr 1552: Log("INFO", "Restarting child procesing ".$deadhost);
1.1 foxr 1553: CreateChild($deadhost);
1554: }
1.13 foxr 1555: }
1556:
1.14 foxr 1557:
1558:
1559: =pod
1560:
1561: =head1 CheckKids
1562:
1563: Since kids do not die as easily in this implementation
1564: as the previous one, there is no need to restart the
1565: dead ones (all dead kids get restarted when they die!!)
1566: The only thing this function does is to pass USR1 to the
1567: kids so that they report their status.
1568:
1569: =cut
1570:
1571: sub CheckKids {
1572: Debug(2, "Checking status of children");
1573: my $docdir = $perlvar{'lonDocRoot'};
1574: my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt");
1575: my $now=time;
1576: my $local=localtime($now);
1577: print $fh "LONC status $local - parent $$ \n\n";
1.23 foxr 1578: foreach my $pid (keys %ChildHash) {
1.14 foxr 1579: Debug(2, "Sending USR1 -> $pid");
1580: kill 'USR1' => $pid; # Tell Child to report status.
1581: sleep 1; # Wait so file doesn't intermix.
1582: }
1583: }
1.24 foxr 1584:
1585: =pod
1586:
1587: =head1 UpdateKids
1588:
1.25 foxr 1589: parent's SIGUSR2 handler. This handler:
1.24 foxr 1590:
1591: =item
1592:
1593: Rereads the hosts file.
1594:
1595: =item
1596:
1597: Kills off (via sigint) children for hosts that have disappeared.
1598:
1599: =item
1600:
1.27 foxr 1601: QUITs children for hosts that already exist (this just forces a status display
1.24 foxr 1602: and resets the connection retry count for that host.
1603:
1604: =item
1605:
1606: Starts new children for hosts that have been added to the hosts.tab file since
1607: the start of the master program and maintains them.
1608:
1609: =cut
1610:
1611: sub UpdateKids {
1.27 foxr 1612:
1.25 foxr 1613: Log("INFO", "Updating connections via SIGUSR2");
1.27 foxr 1614:
1615: # Just in case we need to kill our own lonc, we wait a few seconds to
1616: # give it a chance to receive and relay lond's response to the
1617: # re-init command.
1618: #
1619:
1620: sleep(2); # Wait a couple of seconds.
1621:
1622: my %hosts; # Indexed by loncapa hostname, value=ip.
1623:
1624: # Need to re-read the host table:
1625:
1626:
1627: LondConnection::ReadConfig();
1628: my $I = LondConnection::GetHostIterator;
1629: while (! $I->end()) {
1630: my $item = $I->get();
1631: $hosts{$item->[0]} = $item->[4];
1632: $I->next();
1633: }
1634:
1635: # The logic below is written for clarity not for efficiency.
1636: # Since I anticipate that this function is only rarely called, that's
1637: # appropriate. There are certainly ways to combine the loops below,
1638: # and anyone wishing to obscure the logic is welcome to go for it.
1639: # Note that we don't re-direct sigchild. Instead we do what's needed
1640: # to the data structures that keep track of children to ensure that
1641: # when sigchild is honored, no new child is born.
1642: #
1643:
1644: # For each existing child; if it's host doesn't exist, kill the child.
1645:
1646: foreach my $child (keys %ChildHash) {
1647: my $oldhost = $ChildHash{$child};
1648: if (!(exists $hosts{$oldhost})) {
1649: Log("CRITICAL", "Killing child for $oldhost host no longer exists");
1650: delete $ChildHash{$child};
1651: delete $HostToPid{$oldhost};
1652: kill 'QUIT' => $child;
1653: }
1654: }
1655: # For each remaining existing child; if it's host's ip has changed,
1656: # Restart the child on the new IP.
1657:
1658: foreach my $child (keys %ChildHash) {
1659: my $oldhost = $ChildHash{$child};
1660: my $oldip = $HostHash{$oldhost};
1661: if ($hosts{$oldhost} ne $oldip) {
1662:
1663: # kill the old child.
1664:
1665: Log("CRITICAL", "Killing child for $oldhost host ip has changed...");
1666: delete $ChildHash{$child};
1667: delete $HostToPid{$oldhost};
1668: kill 'QUIT' => $child;
1669:
1670: # Do the book-keeping needed to start a new child on the
1671: # new ip.
1672:
1673: $HostHash{$oldhost} = $hosts{$oldhost};
1674: CreateChild($oldhost);
1675: }
1676: }
1677: # Finally, for each new host, not in the host hash, create a
1678: # enter the host and create a new child.
1679: # Force a status display of any existing process.
1680:
1681: foreach my $host (keys %hosts) {
1682: if(!(exists $HostHash{$host})) {
1683: Log("INFO", "New host $host discovered in hosts.tab...");
1684: $HostHash{$host} = $hosts{$host};
1685: CreateChild($host);
1686: } else {
1687: kill 'HUP' => $HostToPid{$host}; # status display.
1688: }
1689: }
1.24 foxr 1690: }
1691:
1.14 foxr 1692:
1.13 foxr 1693: =pod
1694:
1695: =head1 Restart
1696:
1697: Signal handler for HUP... all children are killed and
1698: we self restart. This is an el-cheapo way to re read
1699: the config file.
1700:
1701: =cut
1702:
1703: sub Restart {
1.23 foxr 1704: &KillThemAll; # First kill all the children.
1.13 foxr 1705: Log("CRITICAL", "Restarting");
1706: my $execdir = $perlvar{'lonDaemons'};
1707: unlink("$execdir/logs/lonc.pid");
1.28 albertel 1708: exec("$execdir/loncnew");
1.10 foxr 1709: }
1.12 foxr 1710:
1711: =pod
1712:
1713: =head1 KillThemAll
1714:
1715: Signal handler that kills all children by sending them a
1.17 foxr 1716: SIGHUP. Responds to sigint and sigterm.
1.12 foxr 1717:
1718: =cut
1719:
1.10 foxr 1720: sub KillThemAll {
1.12 foxr 1721: Debug(2, "Kill them all!!");
1722: local($SIG{CHLD}) = 'IGNORE'; # Our children >will< die.
1.23 foxr 1723: foreach my $pid (keys %ChildHash) {
1.12 foxr 1724: my $serving = $ChildHash{$pid};
1725: Debug(2, "Killing lonc for $serving pid = $pid");
1726: ShowStatus("Killing lonc for $serving pid = $pid");
1727: Log("CRITICAL", "Killing lonc for $serving pid = $pid");
1.17 foxr 1728: kill 'QUIT' => $pid;
1729: delete($ChildHash{$pid});
1.12 foxr 1730: }
1.14 foxr 1731: my $execdir = $perlvar{'lonDaemons'};
1732: unlink("$execdir/logs/lonc.pid");
1.17 foxr 1733:
1.1 foxr 1734: }
1.12 foxr 1735:
1.14 foxr 1736: =pod
1737:
1738: =head1 Terminate
1739:
1740: Terminate the system.
1741:
1742: =cut
1743:
1744: sub Terminate {
1745: KillThemAll;
1.17 foxr 1746: Log("CRITICAL","Master process exiting");
1747: exit 0;
1.14 foxr 1748:
1749: }
1.12 foxr 1750: =pod
1.1 foxr 1751:
1752: =head1 Theory
1.3 albertel 1753:
1754: The event class is used to build this as a single process with an
1755: event driven model. The following events are handled:
1.1 foxr 1756:
1757: =item UNIX Socket connection Received
1758:
1759: =item Request data arrives on UNIX data transfer socket.
1760:
1761: =item lond connection becomes writable.
1762:
1763: =item timer fires at 1 second intervals.
1764:
1765: All sockets are run in non-blocking mode. Timeouts managed by the timer
1766: handler prevents hung connections.
1767:
1768: Key data structures:
1769:
1.3 albertel 1770: =item RequestQueue
1771:
1772: A queue of requests received from UNIX sockets that are
1773: waiting for a chance to be forwarded on a lond connection socket.
1774:
1775: =item ActiveConnections
1776:
1777: A hash of lond connections that have transactions in process that are
1778: available to be timed out.
1779:
1780: =item ActiveTransactions
1781:
1782: A hash indexed by lond connections that contain the client reply
1783: socket for each connection that has an active transaction on it.
1784:
1785: =item IdleConnections
1786:
1787: A hash of lond connections that have no work to do. These connections
1788: can be closed if they are idle for a long enough time.
1.1 foxr 1789:
1790: =cut
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