Annotation of loncom/loncnew, revision 1.15
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: #
1.15 ! foxr 5: # $Id: loncnew,v 1.14 2003/07/03 02:10:18 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: #
1.15 ! foxr 30: # new lonc handles n request out bver m connections to londs.
1.1 foxr 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 $
1.15 ! foxr 49: # Revision 1.14 2003/07/03 02:10:18 foxr
! 50: # Get all of the signals to work correctly.
! 51: #
1.14 foxr 52: # Revision 1.13 2003/07/02 01:31:55 foxr
53: # Added kill -HUP logic (restart).
54: #
1.12 foxr 55: # Revision 1.11 2003/06/25 01:54:44 foxr
56: # Fix more problems with transaction failure.
57: #
1.11 foxr 58: # Revision 1.10 2003/06/24 02:46:04 foxr
59: # Put a limit on the number of times we'll retry a connection.
60: # Start getting the signal stuff put in as well...note that need to get signals
61: # going or else 6the client will permanently give up on dead servers.
62: #
1.10 foxr 63: # Revision 1.9 2003/06/13 02:38:43 foxr
64: # Add logging in 'expected format'
65: #
1.9 foxr 66: # Revision 1.8 2003/06/11 02:04:35 foxr
67: # Support delayed transactions... this is done uniformly by encapsulating
68: # transactions in an object ... a LondTransaction that is implemented by
69: # LondTransaction.pm
70: #
1.8 foxr 71: # Revision 1.7 2003/06/03 01:59:39 foxr
72: # complete coding to support deferred transactions.
73: #
1.7 foxr 74: #
1.1 foxr 75:
76: use lib "/home/httpd/lib/perl/";
77: use lib "/home/foxr/newloncapa/types";
78: use Event qw(:DEFAULT );
79: use POSIX qw(:signal_h);
1.12 foxr 80: use POSIX;
1.1 foxr 81: use IO::Socket;
82: use IO::Socket::INET;
83: use IO::Socket::UNIX;
1.9 foxr 84: use IO::File;
1.6 foxr 85: use IO::Handle;
1.1 foxr 86: use Socket;
87: use Crypt::IDEA;
88: use LONCAPA::Queue;
89: use LONCAPA::Stack;
90: use LONCAPA::LondConnection;
1.7 foxr 91: use LONCAPA::LondTransaction;
1.1 foxr 92: use LONCAPA::Configuration;
93: use LONCAPA::HashIterator;
94:
95:
96: #
97: # Disable all signals we might receive from outside for now.
98: #
1.14 foxr 99: #$SIG{QUIT} = IGNORE;
100: #$SIG{HUP} = IGNORE;
101: #$SIG{USR1} = IGNORE;
102: #$SIG{INT} = IGNORE;
103: #$SIG{CHLD} = IGNORE;
104: #$SIG{__DIE__} = IGNORE;
1.1 foxr 105:
106:
107: # Read the httpd configuration file to get perl variables
108: # normally set in apache modules:
109:
110: my $perlvarref = LONCAPA::Configuration::read_conf('loncapa.conf');
111: my %perlvar = %{$perlvarref};
112:
113: #
114: # parent and shared variables.
115:
116: my %ChildHash; # by pid -> host.
117:
118:
1.9 foxr 119: my $MaxConnectionCount = 10; # Will get from config later.
1.1 foxr 120: my $ClientConnection = 0; # Uniquifier for client events.
121:
1.9 foxr 122: my $DebugLevel = 0;
1.1 foxr 123: my $IdleTimeout= 3600; # Wait an hour before pruning connections.
124:
125: #
126: # The variables below are only used by the child processes.
127: #
128: my $RemoteHost; # Name of host child is talking to.
129: my $UnixSocketDir= "/home/httpd/sockets";
130: my $IdleConnections = Stack->new(); # Set of idle connections
131: my %ActiveConnections; # Connections to the remote lond.
1.7 foxr 132: my %ActiveTransactions; # LondTransactions in flight.
1.1 foxr 133: my %ActiveClients; # Serial numbers of active clients by socket.
134: my $WorkQueue = Queue->new(); # Queue of pending transactions.
135: my $ConnectionCount = 0;
1.4 foxr 136: my $IdleSeconds = 0; # Number of seconds idle.
1.9 foxr 137: my $Status = ""; # Current status string.
1.14 foxr 138: my $RecentLogEntry = "";
1.10 foxr 139: my $ConnectionRetries=5; # Number of connection retries allowed.
140: my $ConnectionRetriesLeft=5; # Number of connection retries remaining.
1.1 foxr 141:
142: #
1.9 foxr 143: # The hash below gives the HTML format for log messages
144: # given a severity.
145: #
146: my %LogFormats;
147:
148: $LogFormats{"CRITICAL"} = "<font color=red>CRITICAL: %s</font>";
149: $LogFormats{"SUCCESS"} = "<font color=green>SUCCESS: %s</font>";
150: $LogFormats{"INFO"} = "<font color=yellow>INFO: %s</font>";
151: $LogFormats{"WARNING"} = "<font color=blue>WARNING: %s</font>";
152: $LogFormats{"DEFAULT"} = " %s ";
153:
1.10 foxr 154:
155:
156: =pod
157:
158: =head2 LogPerm
159:
160: Makes an entry into the permanent log file.
161:
162: =cut
163: sub LogPerm {
164: my $message=shift;
165: my $execdir=$perlvar{'lonDaemons'};
166: my $now=time;
167: my $local=localtime($now);
168: my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
169: print $fh "$now:$message:$local\n";
170: }
1.9 foxr 171:
172: =pod
173:
174: =head2 Log
175:
176: Logs a message to the log file.
177: Parameters:
178:
179: =item severity
180:
181: One of CRITICAL, WARNING, INFO, SUCCESS used to select the
182: format string used to format the message. if the severity is
183: not a defined severity the Default format string is used.
184:
185: =item message
186:
187: The base message. In addtion to the format string, the message
188: will be appended to a string containing the name of our remote
189: host and the time will be formatted into the message.
190:
191: =cut
192:
193: sub Log {
194: my $severity = shift;
195: my $message = shift;
196:
197: if(!$LogFormats{$severity}) {
198: $severity = "DEFAULT";
199: }
200:
201: my $format = $LogFormats{$severity};
202:
203: # Put the window dressing in in front of the message format:
204:
205: my $now = time;
206: my $local = localtime($now);
207: my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
208: my $finalformat = $finalformat.$format."\n";
209:
210: # open the file and put the result.
211:
212: my $execdir = $perlvar{'lonDaemons'};
213: my $fh = IO::File->new(">>$execdir/logs/lonc.log");
214: my $msg = sprintf($finalformat, $message);
1.14 foxr 215: $RecentLogEntry = $msg;
1.9 foxr 216: print $fh $msg;
217:
1.10 foxr 218:
1.9 foxr 219: }
1.6 foxr 220:
1.3 albertel 221:
1.1 foxr 222: =pod
1.3 albertel 223:
224: =head2 GetPeerName
225:
226: Returns the name of the host that a socket object is connected to.
227:
1.1 foxr 228: =cut
229:
230: sub GetPeername {
231: my $connection = shift;
232: my $AdrFamily = shift;
233: my $peer = $connection->peername();
234: my $peerport;
235: my $peerip;
236: if($AdrFamily == AF_INET) {
237: ($peerport, $peerip) = sockaddr_in($peer);
238: my $peername = gethostbyaddr($iaddr, $AdrFamily);
239: return $peername;
240: } elsif ($AdrFamily == AF_UNIX) {
241: my $peerfile;
242: ($peerfile) = sockaddr_un($peer);
243: return $peerfile;
244: }
245: }
246: #----------------------------- Timer management ------------------------
247: =pod
1.3 albertel 248:
1.1 foxr 249: =head2 Debug
1.3 albertel 250:
251: Invoked to issue a debug message.
252:
1.1 foxr 253: =cut
1.3 albertel 254:
1.1 foxr 255: sub Debug {
256: my $level = shift;
257: my $message = shift;
258: if ($level <= $DebugLevel) {
259: print $message." host = ".$RemoteHost."\n";
260: }
261: }
262:
263: sub SocketDump {
264: my $level = shift;
265: my $socket= shift;
266: if($level <= $DebugLevel) {
267: $socket->Dump();
268: }
269: }
1.3 albertel 270:
1.1 foxr 271: =pod
1.3 albertel 272:
1.5 foxr 273: =head2 ShowStatus
274:
275: Place some text as our pid status.
1.10 foxr 276: and as what we return in a SIGUSR1
1.5 foxr 277:
278: =cut
279: sub ShowStatus {
1.10 foxr 280: my $state = shift;
281: my $now = time;
282: my $local = localtime($now);
283: $Status = $local.": ".$state;
284: $0='lonc: '.$state.' '.$local;
1.5 foxr 285: }
286:
287: =pod
288:
1.15 ! foxr 289: =head 2 SocketTimeout
! 290:
! 291: Called when an action on the socket times out. The socket is
! 292: destroyed and any active transaction is failed.
! 293:
! 294:
! 295: =cut
! 296: sub SocketTimeout {
! 297: my $Socket = shift;
! 298:
! 299: KillSocket($Socket);
! 300: }
! 301:
! 302: =pod
! 303:
1.1 foxr 304: =head2 Tick
1.3 albertel 305:
306: Invoked each timer tick.
307:
1.1 foxr 308: =cut
309:
1.5 foxr 310:
1.1 foxr 311: sub Tick {
312: my $client;
1.5 foxr 313: ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount);
1.12 foxr 314:
1.4 foxr 315: # Is it time to prune connection count:
316:
317:
318: if($IdleConnections->Count() &&
319: ($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
320: $IdleSeconds++;
321: if($IdleSeconds > $IdleTimeout) { # Prune a connection...
322: $Socket = $IdleConnections->pop();
1.6 foxr 323: KillSocket($Socket);
1.4 foxr 324: }
325: } else {
326: $IdleSeconds = 0; # Reset idle count if not idle.
327: }
1.15 ! foxr 328: #
! 329: # For each inflight transaction, tick down its timeout counter.
! 330: #
! 331: foreach $item (keys %ActiveTransactions) {
! 332: my $Socket = $ActiveTransactions{$item}->getServer();
! 333: $Socket->Tick();
! 334: }
1.5 foxr 335: # Do we have work in the queue, but no connections to service them?
336: # If so, try to make some new connections to get things going again.
337: #
338:
339: my $Requests = $WorkQueue->Count();
1.10 foxr 340: if (($ConnectionCount == 0) && ($Requests > 0)) {
341: if ($ConnectionRetriesLeft > 0) {
342: my $Connections = ($Requests <= $MaxConnectionCount) ?
343: $Requests : $MaxConnectionCount;
344: Debug(1,"Work but no connections, start ".$Connections." of them");
345: for ($i =0; $i < $Connections; $i++) {
346: MakeLondConnection();
347: }
348: } else {
349: Debug(1,"Work in queue, but gave up on connections..flushing\n");
350: EmptyQueue(); # Connections can't be established.
1.5 foxr 351: }
352:
353: }
1.1 foxr 354: }
355:
356: =pod
1.3 albertel 357:
1.1 foxr 358: =head2 SetupTimer
359:
1.3 albertel 360: Sets up a 1 per sec recurring timer event. The event handler is used to:
1.1 foxr 361:
1.3 albertel 362: =item
363:
364: Trigger timeouts on communications along active sockets.
365:
366: =item
367:
368: Trigger disconnections of idle sockets.
1.1 foxr 369:
370: =cut
371:
372: sub SetupTimer {
373: Debug(6, "SetupTimer");
374: Event->timer(interval => 1, debug => 1, cb => \&Tick );
375: }
1.3 albertel 376:
1.1 foxr 377: =pod
1.3 albertel 378:
1.1 foxr 379: =head2 ServerToIdle
1.3 albertel 380:
381: This function is called when a connection to the server is
382: ready for more work.
383:
384: If there is work in the Work queue the top element is dequeued
1.1 foxr 385: and the connection will start to work on it. If the work queue is
386: empty, the connection is pushed on the idle connection stack where
387: it will either get another work unit, or alternatively, if it sits there
388: long enough, it will be shut down and released.
389:
1.3 albertel 390: =cut
1.1 foxr 391:
392: sub ServerToIdle {
393: my $Socket = shift; # Get the socket.
1.7 foxr 394: delete($ActiveTransactions{$Socket}); # Server has no transaction
1.1 foxr 395:
396: &Debug(6, "Server to idle");
397:
398: # If there's work to do, start the transaction:
399:
1.7 foxr 400: $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
1.1 foxr 401: unless($reqdata eq undef) {
1.7 foxr 402: Debug(9, "Queue gave request data: ".$reqdata->getRequest());
403: &StartRequest($Socket, $reqdata);
1.8 foxr 404:
1.1 foxr 405: } else {
406:
407: # There's no work waiting, so push the server to idle list.
408: &Debug(8, "No new work requests, server connection going idle");
409: $IdleConnections->push($Socket);
410: }
411: }
1.3 albertel 412:
1.1 foxr 413: =pod
1.3 albertel 414:
1.1 foxr 415: =head2 ClientWritable
1.3 albertel 416:
417: Event callback for when a client socket is writable.
418:
419: This callback is established when a transaction reponse is
420: avaiable from lond. The response is forwarded to the unix socket
421: as it becomes writable in this sub.
422:
1.1 foxr 423: Parameters:
424:
1.3 albertel 425: =item Event
426:
427: The event that has been triggered. Event->w->data is
428: the data and Event->w->fd is the socket to write.
1.1 foxr 429:
430: =cut
1.3 albertel 431:
1.1 foxr 432: sub ClientWritable {
433: my $Event = shift;
434: my $Watcher = $Event->w;
435: my $Data = $Watcher->data;
436: my $Socket = $Watcher->fd;
437:
438: # Try to send the data:
439:
440: &Debug(6, "ClientWritable writing".$Data);
441: &Debug(9, "Socket is: ".$Socket);
442:
1.6 foxr 443: if($Socket->connected) {
444: my $result = $Socket->send($Data, 0);
445:
446: # $result undefined: the write failed.
447: # otherwise $result is the number of bytes written.
448: # Remove that preceding string from the data.
449: # If the resulting data is empty, destroy the watcher
450: # and set up a read event handler to accept the next
451: # request.
452:
453: &Debug(9,"Send result is ".$result." Defined: ".defined($result));
454: if(defined($result)) {
455: &Debug(9, "send result was defined");
456: if($result == length($Data)) { # Entire string sent.
457: &Debug(9, "ClientWritable data all written");
458: $Watcher->cancel();
459: #
460: # Set up to read next request from socket:
461:
462: my $descr = sprintf("Connection to lonc client %d",
463: $ActiveClients{$Socket});
464: Event->io(cb => \&ClientRequest,
465: poll => 'r',
466: desc => $descr,
467: data => "",
468: fd => $Socket);
469:
470: } else { # Partial string sent.
471: $Watcher->data(substr($Data, $result));
1.15 ! foxr 472: if($result == 0) { # client hung up on us!!
! 473: Log("INFO", "lonc pipe client hung up on us!");
! 474: $Watcher->cancel;
! 475: $Socket->shutdown(2);
! 476: $Socket->close();
! 477: }
1.6 foxr 478: }
479:
480: } else { # Error of some sort...
481:
482: # Some errnos are possible:
483: my $errno = $!;
484: if($errno == POSIX::EWOULDBLOCK ||
485: $errno == POSIX::EAGAIN ||
486: $errno == POSIX::EINTR) {
487: # No action taken?
488: } else { # Unanticipated errno.
489: &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
490: $Watcher->cancel; # Stop the watcher.
491: $Socket->shutdown(2); # Kill connection
492: $Socket->close(); # Close the socket.
493: }
1.1 foxr 494:
495: }
1.6 foxr 496: } else {
497: $Watcher->cancel(); # A delayed request...just cancel.
1.1 foxr 498: }
499: }
500:
501: =pod
1.3 albertel 502:
1.1 foxr 503: =head2 CompleteTransaction
1.3 albertel 504:
505: Called when the reply data has been received for a lond
1.1 foxr 506: transaction. The reply data must now be sent to the
507: ultimate client on the other end of the Unix socket. This is
508: done by setting up a writable event for the socket with the
509: data the reply data.
1.3 albertel 510:
1.1 foxr 511: Parameters:
1.3 albertel 512:
513: =item Socket
514:
515: Socket on which the lond transaction occured. This is a
516: LondConnection. The data received is in the TransactionReply member.
517:
1.7 foxr 518: =item Transaction
1.3 albertel 519:
1.7 foxr 520: The transaction that is being completed.
1.1 foxr 521:
522: =cut
1.3 albertel 523:
1.1 foxr 524: sub CompleteTransaction {
525: &Debug(6,"Complete transaction");
526: my $Socket = shift;
1.7 foxr 527: my $Transaction = shift;
1.1 foxr 528:
1.7 foxr 529: if (!$Transaction->isDeferred()) { # Normal transaction
530: my $data = $Socket->GetReply(); # Data to send.
531: StartClientReply($Transaction, $data);
532: } else { # Delete deferred transaction file.
1.9 foxr 533: Log("SUCCESS", "A delayed transaction was completed");
1.10 foxr 534: LogPerm("S:$Client:".$Transaction->getRequest());
1.7 foxr 535: unlink $Transaction->getFile();
536: }
1.6 foxr 537: }
538: =pod
539: =head1 StartClientReply
540:
541: Initiates a reply to a client where the reply data is a parameter.
542:
1.7 foxr 543: =head2 parameters:
544:
545: =item Transaction
546:
547: The transaction for which we are responding to the client.
548:
549: =item data
550:
551: The data to send to apached client.
552:
1.6 foxr 553: =cut
554: sub StartClientReply {
1.7 foxr 555: my $Transaction = shift;
1.6 foxr 556: my $data = shift;
1.1 foxr 557:
1.12 foxr 558:
1.7 foxr 559: my $Client = $Transaction->getClient();
560:
1.1 foxr 561: &Debug(8," Reply was: ".$data);
562: my $Serial = $ActiveClients{$Client};
563: my $desc = sprintf("Connection to lonc client %d",
1.6 foxr 564:
1.1 foxr 565: $Serial);
566: Event->io(fd => $Client,
567: poll => "w",
568: desc => $desc,
569: cb => \&ClientWritable,
570: data => $data);
571: }
1.4 foxr 572: =pod
573: =head2 FailTransaction
574:
575: Finishes a transaction with failure because the associated lond socket
1.7 foxr 576: disconnected. There are two possibilities:
577: - The transaction is deferred: in which case we just quietly
578: delete the transaction since there is no client connection.
579: - The transaction is 'live' in which case we initiate the sending
580: of "con_lost" to the client.
581:
582: Deleting the transaction means killing it from the
583: %ActiveTransactions hash.
1.4 foxr 584:
585: Parameters:
586:
587: =item client
588:
1.7 foxr 589: The LondTransaction we are failing.
590:
1.4 foxr 591: =cut
592:
593: sub FailTransaction {
1.7 foxr 594: my $transaction = shift;
1.10 foxr 595: Debug(1, "Failing transaction: ".$transaction->getRequest());
596: if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
1.11 foxr 597: my $client = $transaction->getClient();
1.10 foxr 598: Debug(1," Replying con_lost to ".$transaction->getRequest());
1.11 foxr 599: StartClientReply($transaction, "con_lost\n");
1.7 foxr 600: }
1.4 foxr 601:
602: }
603:
604: =pod
1.6 foxr 605: =head1 EmptyQueue
1.7 foxr 606:
1.6 foxr 607: Fails all items in the work queue with con_lost.
1.7 foxr 608: Note that each item in the work queue is a transaction.
609:
1.6 foxr 610: =cut
611: sub EmptyQueue {
612: while($WorkQueue->Count()) {
1.10 foxr 613: my $request = $WorkQueue->dequeue(); # This is a transaction
1.7 foxr 614: FailTransaction($request);
1.6 foxr 615: }
616: }
617:
618: =pod
1.4 foxr 619:
1.9 foxr 620: =head2 CloseAllLondConnections
621:
622: Close all connections open on lond prior to exit e.g.
623:
624: =cut
625: sub CloseAllLondConnections {
626: foreach $Socket (keys %ActiveConnections) {
627: KillSocket($Socket);
628: }
629: }
630: =cut
631:
632: =pod
633:
1.4 foxr 634: =head2 KillSocket
635:
636: Destroys a socket. This function can be called either when a socket
637: has died of 'natural' causes or because a socket needs to be pruned due to
638: idleness. If the socket has died naturally, if there are no longer any
639: live connections a new connection is created (in case there are transactions
640: in the queue). If the socket has been pruned, it is never re-created.
641:
642: Parameters:
1.1 foxr 643:
1.4 foxr 644: =item Socket
645:
646: The socket to kill off.
647:
648: =item Restart
649:
650: nonzero if we are allowed to create a new connection.
651:
652:
653: =cut
654: sub KillSocket {
655: my $Socket = shift;
656:
1.9 foxr 657: $Socket->Shutdown();
658:
1.7 foxr 659: # If the socket came from the active connection set,
660: # delete its transaction... note that FailTransaction should
661: # already have been called!!!
662: # otherwise it came from the idle set.
663: #
1.4 foxr 664:
665: if(exists($ActiveTransactions{$Socket})) {
666: delete ($ActiveTransactions{$Socket});
667: }
668: if(exists($ActiveConnections{$Socket})) {
669: delete($ActiveConnections{$Socket});
670: }
671: $ConnectionCount--;
1.6 foxr 672:
673: # If the connection count has gone to zero and there is work in the
674: # work queue, the work all gets failed with con_lost.
675: #
676: if($ConnectionCount == 0) {
677: EmptyQueue;
1.4 foxr 678: }
679: }
1.1 foxr 680:
681: =pod
1.3 albertel 682:
1.1 foxr 683: =head2 LondReadable
1.3 albertel 684:
1.1 foxr 685: This function is called whenever a lond connection
686: is readable. The action is state dependent:
687:
1.3 albertel 688: =head3 State=Initialized
689:
690: We''re waiting for the challenge, this is a no-op until the
1.1 foxr 691: state changes.
1.3 albertel 692:
1.1 foxr 693: =head3 State=Challenged
1.3 albertel 694:
695: The challenge has arrived we need to transition to Writable.
1.1 foxr 696: The connection must echo the challenge back.
1.3 albertel 697:
1.1 foxr 698: =head3 State=ChallengeReplied
1.3 albertel 699:
700: The challenge has been replied to. The we are receiveing the
1.1 foxr 701: 'ok' from the partner.
1.3 albertel 702:
1.1 foxr 703: =head3 State=RequestingKey
1.3 albertel 704:
705: The ok has been received and we need to send the request for
1.1 foxr 706: an encryption key. Transition to writable for that.
1.3 albertel 707:
1.1 foxr 708: =head3 State=ReceivingKey
1.3 albertel 709:
710: The the key has been requested, now we are reading the new key.
711:
1.1 foxr 712: =head3 State=Idle
1.3 albertel 713:
714: The encryption key has been negotiated or we have finished
1.1 foxr 715: reading data from the a transaction. If the callback data has
716: a client as well as the socket iformation, then we are
717: doing a transaction and the data received is relayed to the client
718: before the socket is put on the idle list.
1.3 albertel 719:
1.1 foxr 720: =head3 State=SendingRequest
1.3 albertel 721:
722: I do not think this state can be received here, but if it is,
1.1 foxr 723: the appropriate thing to do is to transition to writable, and send
724: the request.
1.3 albertel 725:
1.1 foxr 726: =head3 State=ReceivingReply
1.3 albertel 727:
728: We finished sending the request to the server and now transition
1.1 foxr 729: to readable to receive the reply.
730:
731: The parameter to this function are:
1.3 albertel 732:
1.1 foxr 733: The event. Implicit in this is the watcher and its data. The data
734: contains at least the lond connection object and, if a
735: transaction is in progress, the socket attached to the local client.
736:
1.3 albertel 737: =cut
1.1 foxr 738:
739: sub LondReadable {
1.8 foxr 740:
1.1 foxr 741: my $Event = shift;
742: my $Watcher = $Event->w;
743: my $Socket = $Watcher->data;
744: my $client = undef;
745:
1.8 foxr 746: &Debug(6,"LondReadable called state = ".$State);
747:
1.1 foxr 748:
749: my $State = $Socket->GetState(); # All action depends on the state.
750:
751: SocketDump(6, $Socket);
1.12 foxr 752: my $status = $Socket->Readable();
753: &Debug(2, "Socket->Readable returned: $status");
1.1 foxr 754:
1.12 foxr 755: if($status != 0) {
1.4 foxr 756: # bad return from socket read. Currently this means that
757: # The socket has become disconnected. We fail the transaction.
758:
759: if(exists($ActiveTransactions{$Socket})) {
760: Debug(3,"Lond connection lost failing transaction");
761: FailTransaction($ActiveTransactions{$Socket});
762: }
763: $Watcher->cancel();
1.6 foxr 764: KillSocket($Socket);
1.4 foxr 765: return;
1.1 foxr 766: }
767: SocketDump(6,$Socket);
768:
769: $State = $Socket->GetState(); # Update in case of transition.
770: &Debug(6, "After read, state is ".$State);
771:
772: if($State eq "Initialized") {
773:
774:
775: } elsif ($State eq "ChallengeReceived") {
776: # The challenge must be echoed back; The state machine
777: # in the connection takes care of setting that up. Just
778: # need to transition to writable:
779:
1.8 foxr 780: $Watcher->cb(\&LondWritable);
1.1 foxr 781: $Watcher->poll("w");
782:
783: } elsif ($State eq "ChallengeReplied") {
784:
785:
786: } elsif ($State eq "RequestingKey") {
787: # The ok was received. Now we need to request the key
788: # That requires us to be writable:
789:
1.8 foxr 790: $Watcher->cb(\&LondWritable);
1.1 foxr 791: $Watcher->poll("w");
792:
793: } elsif ($State eq "ReceivingKey") {
794:
795: } elsif ($State eq "Idle") {
796: # If necessary, complete a transaction and then go into the
797: # idle queue.
1.8 foxr 798: $Watcher->cancel();
1.1 foxr 799: if(exists($ActiveTransactions{$Socket})) {
800: Debug(8,"Completing transaction!!");
801: CompleteTransaction($Socket,
802: $ActiveTransactions{$Socket});
1.9 foxr 803: } else {
804: Log("SUCCESS", "Connection ".$ConnectionCount." to "
805: .$RemoteHost." now ready for action");
1.1 foxr 806: }
807: ServerToIdle($Socket); # Next work unit or idle.
1.6 foxr 808:
1.1 foxr 809: } elsif ($State eq "SendingRequest") {
810: # We need to be writable for this and probably don't belong
811: # here inthe first place.
812:
813: Deubg(6, "SendingRequest state encountered in readable");
814: $Watcher->poll("w");
815: $Watcher->cb(\&LondWritable);
816:
817: } elsif ($State eq "ReceivingReply") {
818:
819:
820: } else {
821: # Invalid state.
822: Debug(4, "Invalid state in LondReadable");
823: }
824: }
1.3 albertel 825:
1.1 foxr 826: =pod
1.3 albertel 827:
1.1 foxr 828: =head2 LondWritable
1.3 albertel 829:
1.1 foxr 830: This function is called whenever a lond connection
831: becomes writable while there is a writeable monitoring
832: event. The action taken is very state dependent:
1.3 albertel 833:
1.1 foxr 834: =head3 State = Connected
1.3 albertel 835:
836: The connection is in the process of sending the 'init' hailing to the
837: lond on the remote end. The connection object''s Writable member is
838: called. On error, ConnectionError is called to destroy the connection
839: and remove it from the ActiveConnections hash
840:
1.1 foxr 841: =head3 Initialized
1.3 albertel 842:
843: 'init' has been sent, writability monitoring is removed and
844: readability monitoring is started with LondReadable as the callback.
845:
1.1 foxr 846: =head3 ChallengeReceived
1.3 albertel 847:
848: The connection has received the who are you challenge from the remote
849: system, and is in the process of sending the challenge
850: response. Writable is called.
851:
1.1 foxr 852: =head3 ChallengeReplied
1.3 albertel 853:
854: The connection has replied to the initial challenge The we switch to
855: monitoring readability looking for the server to reply with 'ok'.
856:
1.1 foxr 857: =head3 RequestingKey
1.3 albertel 858:
859: The connection is in the process of requesting its encryption key.
860: Writable is called.
861:
1.1 foxr 862: =head3 ReceivingKey
1.3 albertel 863:
864: The connection has sent the request for a key. Switch to readability
865: monitoring to accept the key
866:
1.1 foxr 867: =head3 SendingRequest
1.3 albertel 868:
869: The connection is in the process of sending a request to the server.
870: This request is part of a client transaction. All the states until
871: now represent the client setup protocol. Writable is called.
872:
1.1 foxr 873: =head3 ReceivingReply
874:
1.3 albertel 875: The connection has sent a request. Now it must receive a reply.
876: Readability monitoring is requested.
877:
878: This function is an event handler and therefore receives as
1.1 foxr 879: a parameter the event that has fired. The data for the watcher
880: of this event is a reference to a list of one or two elements,
881: depending on state. The first (and possibly only) element is the
882: socket. The second (present only if a request is in progress)
883: is the socket on which to return a reply to the caller.
884:
885: =cut
1.3 albertel 886:
1.1 foxr 887: sub LondWritable {
888: my $Event = shift;
889: my $Watcher = $Event->w;
1.8 foxr 890: my $Socket = $Watcher->data;
891: my $State = $Socket->GetState();
1.1 foxr 892:
1.8 foxr 893: Debug(6,"LondWritable State = ".$State."\n");
1.1 foxr 894:
1.8 foxr 895:
1.1 foxr 896: # Figure out what to do depending on the state of the socket:
897:
898:
899:
900:
901: SocketDump(6,$Socket);
902:
903: if ($State eq "Connected") {
904:
905: if ($Socket->Writable() != 0) {
906: # The write resulted in an error.
1.4 foxr 907: # We'll treat this as if the socket got disconnected:
1.9 foxr 908: Log("WARNING", "Connection to ".$RemoteHost.
909: " has been disconnected");
1.4 foxr 910: $Watcher->cancel();
1.6 foxr 911: KillSocket($Socket);
1.4 foxr 912: return;
1.1 foxr 913: }
1.4 foxr 914: # "init" is being sent...
915:
1.1 foxr 916:
917: } elsif ($State eq "Initialized") {
918:
919: # Now that init was sent, we switch
920: # to watching for readability:
921:
1.8 foxr 922: $Watcher->cb(\&LondReadable);
1.1 foxr 923: $Watcher->poll("r");
924:
925: } elsif ($State eq "ChallengeReceived") {
926: # We received the challenge, now we
927: # are echoing it back. This is a no-op,
928: # we're waiting for the state to change
929:
930: if($Socket->Writable() != 0) {
1.5 foxr 931:
932: $Watcher->cancel();
1.6 foxr 933: KillSocket($Socket);
1.5 foxr 934: return;
1.1 foxr 935: }
936:
937: } elsif ($State eq "ChallengeReplied") {
938: # The echo was sent back, so we switch
939: # to watching readability.
940:
1.8 foxr 941: $Watcher->cb(\&LondReadable);
1.1 foxr 942: $Watcher->poll("r");
943:
944: } elsif ($State eq "RequestingKey") {
945: # At this time we're requesting the key.
946: # again, this is essentially a no-op.
947: # we'll write the next chunk until the
948: # state changes.
949:
950: if($Socket->Writable() != 0) {
951: # Write resulted in an error.
1.5 foxr 952:
953: $Watcher->cancel();
1.6 foxr 954: KillSocket($Socket);
1.5 foxr 955: return;
956:
1.1 foxr 957: }
958: } elsif ($State eq "ReceivingKey") {
959: # Now we need to wait for the key
960: # to come back from the peer:
961:
1.8 foxr 962: $Watcher->cb(\&LondReadable);
1.1 foxr 963: $Watcher->poll("r");
964:
965: } elsif ($State eq "SendingRequest") {
966: # At this time we are sending a request to the
967: # peer... write the next chunk:
968:
969: if($Socket->Writable() != 0) {
970:
1.5 foxr 971: if(exists($ActiveTransactions{$Socket})) {
972: Debug(3, "Lond connection lost, failing transactions");
973: FailTransaction($ActiveTransactions{$Socket});
974: }
975: $Watcher->cancel();
1.6 foxr 976: KillSocket($Socket);
1.5 foxr 977: return;
978:
1.1 foxr 979: }
980:
981: } elsif ($State eq "ReceivingReply") {
982: # The send has completed. Wait for the
983: # data to come in for a reply.
984: Debug(8,"Writable sent request/receiving reply");
1.8 foxr 985: $Watcher->cb(\&LondReadable);
1.1 foxr 986: $Watcher->poll("r");
987:
988: } else {
989: # Control only passes here on an error:
990: # the socket state does not match any
991: # of the known states... so an error
992: # must be logged.
993:
994: &Debug(4, "Invalid socket state ".$State."\n");
995: }
996:
997: }
1.6 foxr 998: =pod
999:
1000: =cut
1001: sub QueueDelayed {
1.8 foxr 1002: Debug(3,"QueueDelayed called");
1003:
1.6 foxr 1004: my $path = "$perlvar{'lonSockDir'}/delayed";
1.8 foxr 1005:
1006: Debug(4, "Delayed path: ".$path);
1.6 foxr 1007: opendir(DIRHANDLE, $path);
1.8 foxr 1008:
1.6 foxr 1009: @alldelayed = grep /\.$RemoteHost$/, readdir DIRHANDLE;
1.8 foxr 1010: Debug(4, "Got ".$alldelayed." delayed files");
1.6 foxr 1011: closedir(DIRHANDLE);
1012: my $dfname;
1.8 foxr 1013: my $reqfile;
1014: foreach $dfname (sort @alldelayed) {
1015: $reqfile = "$path/$dfname";
1016: Debug(4, "queueing ".$reqfile);
1.6 foxr 1017: my $Handle = IO::File->new($reqfile);
1018: my $cmd = <$Handle>;
1.8 foxr 1019: chomp $cmd; # There may or may not be a newline...
1.12 foxr 1020: $cmd = $cmd."\n"; # now for sure there's exactly one newline.
1.7 foxr 1021: my $Transaction = LondTransaction->new($cmd);
1022: $Transaction->SetDeferred($reqfile);
1023: QueueTransaction($Transaction);
1.6 foxr 1024: }
1025:
1026: }
1.1 foxr 1027:
1028: =pod
1.3 albertel 1029:
1.1 foxr 1030: =head2 MakeLondConnection
1.3 albertel 1031:
1032: Create a new lond connection object, and start it towards its initial
1033: idleness. Once idle, it becomes elligible to receive transactions
1034: from the work queue. If the work queue is not empty when the
1035: connection is completed and becomes idle, it will dequeue an entry and
1036: start off on it.
1037:
1.1 foxr 1038: =cut
1.3 albertel 1039:
1.1 foxr 1040: sub MakeLondConnection {
1041: Debug(4,"MakeLondConnection to ".GetServerHost()." on port "
1042: .GetServerPort());
1043:
1044: my $Connection = LondConnection->new(&GetServerHost(),
1045: &GetServerPort());
1046:
1047: if($Connection == undef) { # Needs to be more robust later.
1.9 foxr 1048: Log("CRITICAL","Failed to make a connection with lond.");
1.10 foxr 1049: $ConnectionRetriesLeft--;
1050: return 0; # Failure.
1.5 foxr 1051: } else {
1.10 foxr 1052: $ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
1.5 foxr 1053: # The connection needs to have writability
1054: # monitored in order to send the init sequence
1055: # that starts the whole authentication/key
1056: # exchange underway.
1057: #
1058: my $Socket = $Connection->GetSocket();
1059: if($Socket == undef) {
1060: die "did not get a socket from the connection";
1061: } else {
1062: &Debug(9,"MakeLondConnection got socket: ".$Socket);
1063: }
1.1 foxr 1064:
1.5 foxr 1065:
1066: $event = Event->io(fd => $Socket,
1067: poll => 'w',
1068: cb => \&LondWritable,
1.8 foxr 1069: data => $Connection,
1.5 foxr 1070: desc => 'Connection to lond server');
1071: $ActiveConnections{$Connection} = $event;
1072:
1073: $ConnectionCount++;
1.8 foxr 1074: Debug(4, "Connection count = ".$ConnectionCount);
1.6 foxr 1075: if($ConnectionCount == 1) { # First Connection:
1076: QueueDelayed;
1077: }
1.9 foxr 1078: Log("SUCESS", "Created connection ".$ConnectionCount
1079: ." to host ".GetServerHost());
1.10 foxr 1080: return 1; # Return success.
1.1 foxr 1081: }
1082:
1083: }
1.3 albertel 1084:
1.1 foxr 1085: =pod
1.3 albertel 1086:
1.1 foxr 1087: =head2 StartRequest
1.3 albertel 1088:
1089: Starts a lond request going on a specified lond connection.
1090: parameters are:
1091:
1092: =item $Lond
1093:
1094: Connection to the lond that will send the transaction and receive the
1095: reply.
1096:
1097: =item $Client
1098:
1099: Connection to the client that is making this request We got the
1100: request from this socket, and when the request has been relayed to
1101: lond and we get a reply back from lond it will get sent to this
1102: socket.
1103:
1104: =item $Request
1105:
1106: The text of the request to send.
1107:
1.1 foxr 1108: =cut
1109:
1110: sub StartRequest {
1111: my $Lond = shift;
1.7 foxr 1112: my $Request = shift; # This is a LondTransaction.
1.1 foxr 1113:
1.7 foxr 1114: Debug(6, "StartRequest: ".$Request->getRequest());
1.1 foxr 1115:
1116: my $Socket = $Lond->GetSocket();
1117:
1.7 foxr 1118: $Request->Activate($Lond);
1119: $ActiveTransactions{$Lond} = $Request;
1.1 foxr 1120:
1.7 foxr 1121: $Lond->InitiateTransaction($Request->getRequest());
1.8 foxr 1122: $event = Event->io(fd => $Socket,
1.1 foxr 1123: poll => "w",
1124: cb => \&LondWritable,
1125: data => $Lond,
1126: desc => "lond transaction connection");
1127: $ActiveConnections{$Lond} = $event;
1128: Debug(8," Start Request made watcher data with ".$event->data."\n");
1129: }
1130:
1131: =pod
1.3 albertel 1132:
1.1 foxr 1133: =head2 QueueTransaction
1.3 albertel 1134:
1135: If there is an idle lond connection, it is put to work doing this
1136: transaction. Otherwise, the transaction is placed in the work queue.
1137: If placed in the work queue and the maximum number of connections has
1138: not yet been created, a new connection will be started. Our goal is
1139: to eventually have a sufficient number of connections that the work
1140: queue will typically be empty. parameters are:
1141:
1142: =item Socket
1143:
1144: open on the lonc client.
1145:
1146: =item Request
1147:
1148: data to send to the lond.
1.1 foxr 1149:
1150: =cut
1.3 albertel 1151:
1.1 foxr 1152: sub QueueTransaction {
1153:
1.7 foxr 1154: my $requestData = shift; # This is a LondTransaction.
1155: my $cmd = $requestData->getRequest();
1156:
1157: Debug(6,"QueueTransaction: ".$cmd);
1.1 foxr 1158:
1159: my $LondSocket = $IdleConnections->pop();
1160: if(!defined $LondSocket) { # Need to queue request.
1161: Debug(8,"Must queue...");
1162: $WorkQueue->enqueue($requestData);
1163: if($ConnectionCount < $MaxConnectionCount) {
1164: Debug(4,"Starting additional lond connection");
1165: MakeLondConnection();
1166: }
1167: } else { # Can start the request:
1168: Debug(8,"Can start...");
1.7 foxr 1169: StartRequest($LondSocket, $requestData);
1.1 foxr 1170: }
1171: }
1172:
1173: #-------------------------- Lonc UNIX socket handling ---------------------
1.3 albertel 1174:
1.1 foxr 1175: =pod
1.3 albertel 1176:
1.1 foxr 1177: =head2 ClientRequest
1.3 albertel 1178: Callback that is called when data can be read from the UNIX domain
1179: socket connecting us with an apache server process.
1.1 foxr 1180:
1181: =cut
1182:
1183: sub ClientRequest {
1184: Debug(6, "ClientRequest");
1185: my $event = shift;
1186: my $watcher = $event->w;
1187: my $socket = $watcher->fd;
1188: my $data = $watcher->data;
1189: my $thisread;
1190:
1191: Debug(9, " Watcher named: ".$watcher->desc);
1192:
1193: my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
1194: Debug(8, "rcv: data length = ".length($thisread)
1195: ." read =".$thisread);
1196: unless (defined $rv && length($thisread)) {
1197: # Likely eof on socket.
1198: Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
1199: close($socket);
1200: $watcher->cancel();
1201: delete($ActiveClients{$socket});
1.10 foxr 1202: return;
1.1 foxr 1203: }
1204: Debug(8,"Data: ".$data." this read: ".$thisread);
1205: $data = $data.$thisread; # Append new data.
1206: $watcher->data($data);
1207: if($data =~ /(.*\n)/) { # Request entirely read.
1.10 foxr 1208: if($data eq "close_connection_exit\n") {
1.9 foxr 1209: Log("CRITICAL",
1210: "Request Close Connection ... exiting");
1211: CloseAllLondConnections();
1212: exit;
1213: }
1.1 foxr 1214: Debug(8, "Complete transaction received: ".$data);
1.8 foxr 1215: my $Transaction = LondTransaction->new($data);
1.7 foxr 1216: $Transaction->SetClient($socket);
1217: QueueTransaction($Transaction);
1.1 foxr 1218: $watcher->cancel(); # Done looking for input data.
1219: }
1220:
1221: }
1222:
1223:
1224: =pod
1.3 albertel 1225:
1.1 foxr 1226: =head2 NewClient
1.3 albertel 1227:
1228: Callback that is called when a connection is received on the unix
1229: socket for a new client of lonc. The callback is parameterized by the
1230: event.. which is a-priori assumed to be an io event, and therefore has
1231: an fd member that is the Listener socket. We Accept the connection
1232: and register a new event on the readability of that socket:
1233:
1.1 foxr 1234: =cut
1.3 albertel 1235:
1.1 foxr 1236: sub NewClient {
1237: Debug(6, "NewClient");
1238: my $event = shift; # Get the event parameters.
1239: my $watcher = $event->w;
1240: my $socket = $watcher->fd; # Get the event' socket.
1241: my $connection = $socket->accept(); # Accept the client connection.
1242: Debug(8,"Connection request accepted from "
1243: .GetPeername($connection, AF_UNIX));
1244:
1245:
1246: my $description = sprintf("Connection to lonc client %d",
1247: $ClientConnection);
1248: Debug(9, "Creating event named: ".$description);
1249: Event->io(cb => \&ClientRequest,
1250: poll => 'r',
1251: desc => $description,
1252: data => "",
1253: fd => $connection);
1254: $ActiveClients{$connection} = $ClientConnection;
1255: $ClientConnection++;
1256: }
1.3 albertel 1257:
1258: =pod
1259:
1260: =head2 GetLoncSocketPath
1261:
1262: Returns the name of the UNIX socket on which to listen for client
1263: connections.
1.1 foxr 1264:
1265: =cut
1.3 albertel 1266:
1.1 foxr 1267: sub GetLoncSocketPath {
1268: return $UnixSocketDir."/".GetServerHost();
1269: }
1270:
1.3 albertel 1271: =pod
1272:
1273: =head2 GetServerHost
1274:
1275: Returns the host whose lond we talk with.
1276:
1.1 foxr 1277: =cut
1.3 albertel 1278:
1.7 foxr 1279: sub GetServerHost {
1.1 foxr 1280: return $RemoteHost; # Setup by the fork.
1281: }
1.3 albertel 1282:
1283: =pod
1284:
1285: =head2 GetServerPort
1286:
1287: Returns the lond port number.
1288:
1.1 foxr 1289: =cut
1.3 albertel 1290:
1.7 foxr 1291: sub GetServerPort {
1.1 foxr 1292: return $perlvar{londPort};
1293: }
1.3 albertel 1294:
1295: =pod
1296:
1297: =head2 SetupLoncListener
1298:
1299: Setup a lonc listener event. The event is called when the socket
1300: becomes readable.. that corresponds to the receipt of a new
1301: connection. The event handler established will accept the connection
1302: (creating a communcations channel), that int turn will establish
1303: another event handler to subess requests.
1.1 foxr 1304:
1305: =cut
1.3 albertel 1306:
1.1 foxr 1307: sub SetupLoncListener {
1308:
1309: my $socket;
1310: my $SocketName = GetLoncSocketPath();
1311: unlink($SocketName);
1.7 foxr 1312: unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,
1.1 foxr 1313: Listen => 10,
1314: Type => SOCK_STREAM)) {
1315: die "Failed to create a lonc listner socket";
1316: }
1317: Event->io(cb => \&NewClient,
1318: poll => 'r',
1319: desc => 'Lonc listener Unix Socket',
1320: fd => $socket);
1321: }
1322:
1.14 foxr 1323: =pod
1324:
1325: =head2 ChildStatus
1326:
1327: Child USR1 signal handler to report the most recent status
1328: into the status file.
1329:
1330: =cut
1331: sub ChildStatus {
1332: my $event = shift;
1333: my $watcher = $event->w;
1334:
1335: Debug(2, "Reporting child status because : ".$watcher->data);
1336: my $docdir = $perlvar{'lonDocRoot'};
1337: my $fh = IO::File->new(">>$docdir/lon-status/loncstatus.txt");
1338: print $fh $$."\t".$RemoteHost."\t".$Status."\t".
1339: $RecentLogEntry."\n";
1340: }
1341:
1.1 foxr 1342: =pod
1.3 albertel 1343:
1.10 foxr 1344: =head2 SignalledToDeath
1345:
1346: Called in response to a signal that causes a chid process to die.
1347:
1348: =cut
1349:
1350:
1351: sub SignalledToDeath {
1.14 foxr 1352: my $event = shift;
1353: my $watcher= $event->w;
1354:
1355: Debug(2,"Signalled to death! via ".$watcher->data);
1.10 foxr 1356: my ($signal) = @_;
1357: chomp($signal);
1358: Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "
1359: ."died through "."\"$signal\"");
1360: LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
1361: ."\"$signal\"");
1362: die("Signal abnormal end");
1.12 foxr 1363: exit 0;
1.10 foxr 1364:
1365: }
1.1 foxr 1366: =head2 ChildProcess
1367:
1368: This sub implements a child process for a single lonc daemon.
1369:
1370: =cut
1371:
1372: sub ChildProcess {
1373:
1374:
1.14 foxr 1375: #
1376: # Signals must be handled by the Event framework...
1377: #
1378: # $SIG{QUIT} = \&SignalledToDeath;
1379: # $SIG{HUP} = \&ChildStatus;
1380: # $SIG{USR1} = IGNORE;
1381: # $SIG{INT} = DEFAULT;
1382: # $SIG{CHLD} = IGNORE;
1383: # $SIG{__DIE__} = \&SignalledToDeath;
1384:
1385: Event->signal(signal => "QUIT",
1386: cb => \&SignalledToDeath,
1387: data => "QUIT");
1388: Event->signal(signal => "HUP",
1389: cb => \&ChildStatus,
1390: data => "HUP");
1391: Event->signal(signal => "USR1",
1392: cb => \&ChildStatus,
1393: data => "USR1");
1.1 foxr 1394:
1395: SetupTimer();
1396:
1397: SetupLoncListener();
1398:
1399: $Event::Debuglevel = $DebugLevel;
1400:
1401: Debug(9, "Making initial lond connection for ".$RemoteHost);
1402:
1403: # Setup the initial server connection:
1404:
1.14 foxr 1405: # &MakeLondConnection(); // let first work requirest do it.
1.10 foxr 1406:
1.5 foxr 1407:
1.1 foxr 1408: Debug(9,"Entering event loop");
1409: my $ret = Event::loop(); # Start the main event loop.
1410:
1411:
1412: die "Main event loop exited!!!";
1413: }
1414:
1415: # Create a new child for host passed in:
1416:
1417: sub CreateChild {
1.12 foxr 1418: my $sigset = POSIX::SigSet->new(SIGINT);
1419: sigprocmask(SIG_BLOCK, $sigset);
1.1 foxr 1420: my $host = shift;
1421: $RemoteHost = $host;
1.9 foxr 1422: Log("CRITICAL", "Forking server for ".$host);
1.1 foxr 1423: $pid = fork;
1424: if($pid) { # Parent
1425: $ChildHash{$pid} = $RemoteHost;
1.12 foxr 1426: sigprocmask(SIG_UNBLOCK, $sigset);
1427:
1.1 foxr 1428: } else { # child.
1.5 foxr 1429: ShowStatus("Connected to ".$RemoteHost);
1.12 foxr 1430: $SIG{INT} = DEFAULT;
1431: sigprocmask(SIG_UNBLOCK, $sigset);
1432: ChildProcess; # Does not return.
1.1 foxr 1433: }
1434:
1435: }
1436: #
1437: # Parent process logic pass 1:
1438: # For each entry in the hosts table, we will
1439: # fork off an instance of ChildProcess to service the transactions
1440: # to that host. Each pid will be entered in a global hash
1441: # with the value of the key, the host.
1442: # The parent will then enter a loop to wait for process exits.
1443: # Each exit gets logged and the child gets restarted.
1444: #
1445:
1.5 foxr 1446: #
1447: # Fork and start in new session so hang-up isn't going to
1448: # happen without intent.
1449: #
1450:
1451:
1.6 foxr 1452:
1453:
1.8 foxr 1454:
1.6 foxr 1455:
1456: ShowStatus("Forming new session");
1457: my $childpid = fork;
1458: if ($childpid != 0) {
1459: sleep 4; # Give child a chacne to break to
1460: exit 0; # a new sesion.
1461: }
1.8 foxr 1462: #
1463: # Write my pid into the pid file so I can be located
1464: #
1465:
1466: ShowStatus("Parent writing pid file:");
1467: $execdir = $perlvar{'lonDaemons'};
1468: open (PIDSAVE, ">$execdir/logs/lonc.pid");
1469: print PIDSAVE "$$\n";
1470: close(PIDSAVE);
1.6 foxr 1471:
1472: if (POSIX::setsid() < 0) {
1473: print "Could not create new session\n";
1474: exit -1;
1475: }
1.5 foxr 1476:
1477: ShowStatus("Forking node servers");
1478:
1.9 foxr 1479: Log("CRITICAL", "--------------- Starting children ---------------");
1480:
1.1 foxr 1481: my $HostIterator = LondConnection::GetHostIterator;
1482: while (! $HostIterator->end()) {
1483:
1484: $hostentryref = $HostIterator->get();
1485: CreateChild($hostentryref->[0]);
1486: $HostIterator->next();
1487: }
1.12 foxr 1488: $RemoteHost = "Parent Server";
1.1 foxr 1489:
1490: # Maintain the population:
1.5 foxr 1491:
1492: ShowStatus("Parent keeping the flock");
1.1 foxr 1493:
1.10 foxr 1494: #
1495: # Set up parent signals:
1496: #
1.12 foxr 1497:
1.14 foxr 1498: $SIG{INT} = \&Terminate;
1499: $SIG{TERM} = \&Terminate;
1.13 foxr 1500: $SIG{HUP} = \&Restart;
1.14 foxr 1501: $SIG{USR1} = \&CheckKids;
1.10 foxr 1502:
1.1 foxr 1503: while(1) {
1504: $deadchild = wait();
1505: if(exists $ChildHash{$deadchild}) { # need to restart.
1506: $deadhost = $ChildHash{$deadchild};
1507: delete($ChildHash{$deadchild});
1.9 foxr 1508: Log("WARNING","Lost child pid= ".$deadchild.
1.1 foxr 1509: "Connected to host ".$deadhost);
1.9 foxr 1510: Log("INFO", "Restarting child procesing ".$deadhost);
1.1 foxr 1511: CreateChild($deadhost);
1512: }
1.13 foxr 1513: }
1514:
1.14 foxr 1515:
1516:
1517: =pod
1518:
1519: =head1 CheckKids
1520:
1521: Since kids do not die as easily in this implementation
1522: as the previous one, there is no need to restart the
1523: dead ones (all dead kids get restarted when they die!!)
1524: The only thing this function does is to pass USR1 to the
1525: kids so that they report their status.
1526:
1527: =cut
1528:
1529: sub CheckKids {
1530: Debug(2, "Checking status of children");
1531: my $docdir = $perlvar{'lonDocRoot'};
1532: my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt");
1533: my $now=time;
1534: my $local=localtime($now);
1535: print $fh "LONC status $local - parent $$ \n\n";
1536: foreach $pid (keys %ChildHash) {
1537: Debug(2, "Sending USR1 -> $pid");
1538: kill 'USR1' => $pid; # Tell Child to report status.
1539: sleep 1; # Wait so file doesn't intermix.
1540: }
1541: }
1542:
1.13 foxr 1543: =pod
1544:
1545: =head1 Restart
1546:
1547: Signal handler for HUP... all children are killed and
1548: we self restart. This is an el-cheapo way to re read
1549: the config file.
1550:
1551: =cut
1552:
1553: sub Restart {
1554: KillThemAll; # First kill all the children.
1555: Log("CRITICAL", "Restarting");
1556: my $execdir = $perlvar{'lonDaemons'};
1557: unlink("$execdir/logs/lonc.pid");
1558: exec("$execdir/lonc");
1.10 foxr 1559: }
1.12 foxr 1560:
1561: =pod
1562:
1563: =head1 KillThemAll
1564:
1565: Signal handler that kills all children by sending them a
1566: SIGINT. Responds to sigint and sigterm.
1567:
1568: =cut
1569:
1.10 foxr 1570: sub KillThemAll {
1.12 foxr 1571: Debug(2, "Kill them all!!");
1572: local($SIG{CHLD}) = 'IGNORE'; # Our children >will< die.
1573: foreach $pid (keys %ChildHash) {
1574: my $serving = $ChildHash{$pid};
1575: Debug(2, "Killing lonc for $serving pid = $pid");
1576: ShowStatus("Killing lonc for $serving pid = $pid");
1577: Log("CRITICAL", "Killing lonc for $serving pid = $pid");
1578: kill('INT', $pid);
1.14 foxr 1579: delete($ChildeHash{$pid});
1.12 foxr 1580: }
1.14 foxr 1581: my $execdir = $perlvar{'lonDaemons'};
1582: unlink("$execdir/logs/lonc.pid");
1583: ShowStatus("Killing the master process");
1.12 foxr 1584: Log("CRITICAL", "Killing the master process.");
1.1 foxr 1585: }
1.12 foxr 1586:
1.14 foxr 1587: =pod
1588:
1589: =head1 Terminate
1590:
1591: Terminate the system.
1592:
1593: =cut
1594:
1595: sub Terminate {
1596: KillThemAll;
1597: exit;
1598:
1599: }
1.12 foxr 1600: =pod
1.1 foxr 1601:
1602: =head1 Theory
1.3 albertel 1603:
1604: The event class is used to build this as a single process with an
1605: event driven model. The following events are handled:
1.1 foxr 1606:
1607: =item UNIX Socket connection Received
1608:
1609: =item Request data arrives on UNIX data transfer socket.
1610:
1611: =item lond connection becomes writable.
1612:
1613: =item timer fires at 1 second intervals.
1614:
1615: All sockets are run in non-blocking mode. Timeouts managed by the timer
1616: handler prevents hung connections.
1617:
1618: Key data structures:
1619:
1.3 albertel 1620: =item RequestQueue
1621:
1622: A queue of requests received from UNIX sockets that are
1623: waiting for a chance to be forwarded on a lond connection socket.
1624:
1625: =item ActiveConnections
1626:
1627: A hash of lond connections that have transactions in process that are
1628: available to be timed out.
1629:
1630: =item ActiveTransactions
1631:
1632: A hash indexed by lond connections that contain the client reply
1633: socket for each connection that has an active transaction on it.
1634:
1635: =item IdleConnections
1636:
1637: A hash of lond connections that have no work to do. These connections
1638: can be closed if they are idle for a long enough time.
1.1 foxr 1639:
1640: =cut
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/back.gif){kind=icon}
Return to loncnew CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [LON-CAPA] / loncom