Annotation of loncom/loncnew, revision 1.29
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: #
1.29 ! foxr 5: # $Id: loncnew,v 1.28 2003/10/14 15:36:21 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).
1.1 foxr 38: # - Add logging/status monitoring.
39: # - Add Signal handling - HUP restarts. USR1 status report.
1.7 foxr 40: # - Add Configuration file I/O (done).
1.1 foxr 41: # - Add management/status request interface.
1.8 foxr 42: # - Add deferred request capability. (done)
1.9 foxr 43: # - Detect transmission timeouts.
1.7 foxr 44: #
45:
46: # Change log:
1.8 foxr 47: # $Log: loncnew,v $
1.29 ! foxr 48: # Revision 1.28 2003/10/14 15:36:21 albertel
! 49: # - making it easier to run loncnew,
! 50: # /etc/init.d/loncontrol startnew
! 51: # /etc/init.d/loncontrol restartnew
! 52: # will now start loncnew in place of lonc
! 53: #
1.28 albertel 54: # Revision 1.27 2003/10/07 11:23:03 foxr
55: # Installed and tested code to process reinit in parent server.
56: #
1.27 foxr 57: # Revision 1.26 2003/09/30 11:11:17 foxr
58: # Add book-keeping hashes to support the re-init procedure.
59: #
1.26 foxr 60: # Revision 1.25 2003/09/23 11:22:14 foxr
61: # Tested ability to receive sigusr2 This is now logged and must be
62: # properly implemented as a re-read of hosts and re-init of appropriate
63: # children.
64: #
1.25 foxr 65: # Revision 1.24 2003/09/16 09:46:42 foxr
66: # Added skeletal infrastructure to support SIGUSR2 update hosts request.
67: #
1.24 foxr 68: # Revision 1.23 2003/09/15 09:24:49 foxr
69: # Add use strict and fix all the fallout from that.
70: #
1.23 foxr 71: # Revision 1.22 2003/09/02 10:34:47 foxr
72: # - Fix errors in host dead detection logic (too many cases where the
73: # retries left were not getting incremented or just not checked).
74: # - Added some additional status to the ps axuww display:
75: # o Remaining retries on a host.
76: # o >>> DEAD <<< indicator if I've given up on a host.
77: # - Tested the SIGHUP will reset the retries remaining count (thanks to
78: # the above status stuff, and get allow the loncnew to re-try again
79: # on the host (thanks to the log).
80: #
1.22 foxr 81: # Revision 1.21 2003/08/26 09:19:51 foxr
82: # How embarrassing... put in the SocketTimeout function in loncnew and forgot
83: # to actually hook it into the LondTransaction. Added this to MakeLondConnection
84: # where it belongs... hopefully transactions (not just connection attempts) will
85: # timeout more speedily than the socket errors will catch it.
86: #
1.21 foxr 87: # Revision 1.20 2003/08/25 18:48:11 albertel
88: # - fixing a forgotten ;
89: #
1.20 albertel 90: # Revision 1.19 2003/08/19 09:31:46 foxr
91: # Get socket directory from configuration rather than the old hard coded test
92: # way that I forgot to un-hard code.
93: #
1.19 foxr 94: # Revision 1.18 2003/08/06 09:52:29 foxr
95: # Also needed to remember to fail in-flight transactions if their sends fail.
96: #
1.18 foxr 97: # Revision 1.17 2003/08/03 00:44:31 foxr
98: # 1. Correct handling of connection failure: Assume it means the host is
99: # unreachable and fail all of the queued transactions. Note that the
100: # inflight transactions should fail on their own time due either to timeout
101: # or send/receive failures.
102: # 2. Correct handling of logs for forced death signals. Pull the signal
103: # from the event watcher.
104: #
1.17 foxr 105: # Revision 1.16 2003/07/29 02:33:05 foxr
106: # Add SIGINT processing to child processes to toggle annoying trace mode
107: # on/off.. will try to use this to isolate the compute boud process issue.
108: #
1.16 foxr 109: # Revision 1.15 2003/07/15 02:07:05 foxr
110: # Added code for lonc/lond transaction timeouts. Who knows if it works right.
111: # The intent is for a timeout to fail any transaction in progress and kill
112: # off the sockt that timed out.
113: #
1.15 foxr 114: # Revision 1.14 2003/07/03 02:10:18 foxr
115: # Get all of the signals to work correctly.
116: #
1.14 foxr 117: # Revision 1.13 2003/07/02 01:31:55 foxr
118: # Added kill -HUP logic (restart).
119: #
1.12 foxr 120: # Revision 1.11 2003/06/25 01:54:44 foxr
121: # Fix more problems with transaction failure.
122: #
1.11 foxr 123: # Revision 1.10 2003/06/24 02:46:04 foxr
124: # Put a limit on the number of times we'll retry a connection.
125: # Start getting the signal stuff put in as well...note that need to get signals
1.22 foxr 126: # going or else the client will permanently give up on dead servers.
1.11 foxr 127: #
1.10 foxr 128: # Revision 1.9 2003/06/13 02:38:43 foxr
129: # Add logging in 'expected format'
130: #
1.9 foxr 131: # Revision 1.8 2003/06/11 02:04:35 foxr
132: # Support delayed transactions... this is done uniformly by encapsulating
133: # transactions in an object ... a LondTransaction that is implemented by
134: # LondTransaction.pm
135: #
1.8 foxr 136: # Revision 1.7 2003/06/03 01:59:39 foxr
137: # complete coding to support deferred transactions.
138: #
1.7 foxr 139: #
1.23 foxr 140: use strict;
1.1 foxr 141: use lib "/home/httpd/lib/perl/";
142: use lib "/home/foxr/newloncapa/types";
143: use Event qw(:DEFAULT );
144: use POSIX qw(:signal_h);
1.12 foxr 145: use POSIX;
1.1 foxr 146: use IO::Socket;
147: use IO::Socket::INET;
148: use IO::Socket::UNIX;
1.9 foxr 149: use IO::File;
1.6 foxr 150: use IO::Handle;
1.1 foxr 151: use Socket;
152: use Crypt::IDEA;
153: use LONCAPA::Queue;
154: use LONCAPA::Stack;
155: use LONCAPA::LondConnection;
1.7 foxr 156: use LONCAPA::LondTransaction;
1.1 foxr 157: use LONCAPA::Configuration;
158: use LONCAPA::HashIterator;
159:
160:
161: #
162: # Disable all signals we might receive from outside for now.
163: #
164:
165:
166: # Read the httpd configuration file to get perl variables
167: # normally set in apache modules:
168:
169: my $perlvarref = LONCAPA::Configuration::read_conf('loncapa.conf');
170: my %perlvar = %{$perlvarref};
171:
172: #
173: # parent and shared variables.
174:
175: my %ChildHash; # by pid -> host.
1.26 foxr 176: my %HostToPid; # By host -> pid.
177: my %HostHash; # by loncapaname -> IP.
1.1 foxr 178:
179:
1.9 foxr 180: my $MaxConnectionCount = 10; # Will get from config later.
1.1 foxr 181: my $ClientConnection = 0; # Uniquifier for client events.
182:
1.9 foxr 183: my $DebugLevel = 0;
1.29 ! foxr 184: my $NextDebugLevel= 2; # So Sigint can toggle this.
1.1 foxr 185: my $IdleTimeout= 3600; # Wait an hour before pruning connections.
186:
187: #
188: # The variables below are only used by the child processes.
189: #
190: my $RemoteHost; # Name of host child is talking to.
1.20 albertel 191: my $UnixSocketDir= $perlvar{'lonSockDir'};
1.1 foxr 192: my $IdleConnections = Stack->new(); # Set of idle connections
193: my %ActiveConnections; # Connections to the remote lond.
1.7 foxr 194: my %ActiveTransactions; # LondTransactions in flight.
1.1 foxr 195: my %ActiveClients; # Serial numbers of active clients by socket.
196: my $WorkQueue = Queue->new(); # Queue of pending transactions.
197: my $ConnectionCount = 0;
1.4 foxr 198: my $IdleSeconds = 0; # Number of seconds idle.
1.9 foxr 199: my $Status = ""; # Current status string.
1.14 foxr 200: my $RecentLogEntry = "";
1.10 foxr 201: my $ConnectionRetries=5; # Number of connection retries allowed.
202: my $ConnectionRetriesLeft=5; # Number of connection retries remaining.
1.1 foxr 203:
204: #
1.9 foxr 205: # The hash below gives the HTML format for log messages
206: # given a severity.
207: #
208: my %LogFormats;
209:
210: $LogFormats{"CRITICAL"} = "<font color=red>CRITICAL: %s</font>";
211: $LogFormats{"SUCCESS"} = "<font color=green>SUCCESS: %s</font>";
212: $LogFormats{"INFO"} = "<font color=yellow>INFO: %s</font>";
213: $LogFormats{"WARNING"} = "<font color=blue>WARNING: %s</font>";
214: $LogFormats{"DEFAULT"} = " %s ";
215:
1.10 foxr 216:
217:
218: =pod
219:
220: =head2 LogPerm
221:
222: Makes an entry into the permanent log file.
223:
224: =cut
225: sub LogPerm {
226: my $message=shift;
227: my $execdir=$perlvar{'lonDaemons'};
228: my $now=time;
229: my $local=localtime($now);
230: my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
231: print $fh "$now:$message:$local\n";
232: }
1.9 foxr 233:
234: =pod
235:
236: =head2 Log
237:
238: Logs a message to the log file.
239: Parameters:
240:
241: =item severity
242:
243: One of CRITICAL, WARNING, INFO, SUCCESS used to select the
244: format string used to format the message. if the severity is
245: not a defined severity the Default format string is used.
246:
247: =item message
248:
249: The base message. In addtion to the format string, the message
250: will be appended to a string containing the name of our remote
251: host and the time will be formatted into the message.
252:
253: =cut
254:
255: sub Log {
256: my $severity = shift;
257: my $message = shift;
258:
259: if(!$LogFormats{$severity}) {
260: $severity = "DEFAULT";
261: }
262:
263: my $format = $LogFormats{$severity};
264:
265: # Put the window dressing in in front of the message format:
266:
267: my $now = time;
268: my $local = localtime($now);
269: my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
270: my $finalformat = $finalformat.$format."\n";
271:
272: # open the file and put the result.
273:
274: my $execdir = $perlvar{'lonDaemons'};
275: my $fh = IO::File->new(">>$execdir/logs/lonc.log");
276: my $msg = sprintf($finalformat, $message);
1.14 foxr 277: $RecentLogEntry = $msg;
1.9 foxr 278: print $fh $msg;
279:
1.10 foxr 280:
1.9 foxr 281: }
1.6 foxr 282:
1.3 albertel 283:
1.1 foxr 284: =pod
1.3 albertel 285:
286: =head2 GetPeerName
287:
288: Returns the name of the host that a socket object is connected to.
289:
1.1 foxr 290: =cut
291:
292: sub GetPeername {
293: my $connection = shift;
294: my $AdrFamily = shift;
295: my $peer = $connection->peername();
296: my $peerport;
297: my $peerip;
298: if($AdrFamily == AF_INET) {
299: ($peerport, $peerip) = sockaddr_in($peer);
1.23 foxr 300: my $peername = gethostbyaddr($peerip, $AdrFamily);
1.1 foxr 301: return $peername;
302: } elsif ($AdrFamily == AF_UNIX) {
303: my $peerfile;
304: ($peerfile) = sockaddr_un($peer);
305: return $peerfile;
306: }
307: }
308: #----------------------------- Timer management ------------------------
309: =pod
1.3 albertel 310:
1.1 foxr 311: =head2 Debug
1.3 albertel 312:
313: Invoked to issue a debug message.
314:
1.1 foxr 315: =cut
1.3 albertel 316:
1.1 foxr 317: sub Debug {
318: my $level = shift;
319: my $message = shift;
320: if ($level <= $DebugLevel) {
1.23 foxr 321: Log("INFO", "-Debug- $message host = $RemoteHost");
1.1 foxr 322: }
323: }
324:
325: sub SocketDump {
326: my $level = shift;
327: my $socket= shift;
328: if($level <= $DebugLevel) {
329: $socket->Dump();
330: }
331: }
1.3 albertel 332:
1.1 foxr 333: =pod
1.3 albertel 334:
1.5 foxr 335: =head2 ShowStatus
336:
337: Place some text as our pid status.
1.10 foxr 338: and as what we return in a SIGUSR1
1.5 foxr 339:
340: =cut
341: sub ShowStatus {
1.10 foxr 342: my $state = shift;
343: my $now = time;
344: my $local = localtime($now);
345: $Status = $local.": ".$state;
346: $0='lonc: '.$state.' '.$local;
1.5 foxr 347: }
348:
349: =pod
350:
1.15 foxr 351: =head 2 SocketTimeout
352:
353: Called when an action on the socket times out. The socket is
354: destroyed and any active transaction is failed.
355:
356:
357: =cut
358: sub SocketTimeout {
359: my $Socket = shift;
360:
1.22 foxr 361: KillSocket($Socket); # A transaction timeout also counts as
362: # a connection failure:
363: $ConnectionRetriesLeft--;
1.15 foxr 364: }
365:
366: =pod
367:
1.1 foxr 368: =head2 Tick
1.3 albertel 369:
370: Invoked each timer tick.
371:
1.1 foxr 372: =cut
373:
1.5 foxr 374:
1.1 foxr 375: sub Tick {
376: my $client;
1.22 foxr 377: if($ConnectionRetriesLeft > 0) {
378: ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
379: ." Retries remaining: ".$ConnectionRetriesLeft);
380: } else {
381: ShowStatus(GetServerHost()." >> DEAD <<");
382: }
1.4 foxr 383: # Is it time to prune connection count:
384:
385:
386: if($IdleConnections->Count() &&
387: ($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
388: $IdleSeconds++;
389: if($IdleSeconds > $IdleTimeout) { # Prune a connection...
1.23 foxr 390: my $Socket = $IdleConnections->pop();
1.6 foxr 391: KillSocket($Socket);
1.4 foxr 392: }
393: } else {
394: $IdleSeconds = 0; # Reset idle count if not idle.
395: }
1.15 foxr 396: #
397: # For each inflight transaction, tick down its timeout counter.
398: #
1.23 foxr 399: foreach my $item (keys %ActiveTransactions) {
1.15 foxr 400: my $Socket = $ActiveTransactions{$item}->getServer();
401: $Socket->Tick();
402: }
1.5 foxr 403: # Do we have work in the queue, but no connections to service them?
404: # If so, try to make some new connections to get things going again.
405: #
406:
407: my $Requests = $WorkQueue->Count();
1.10 foxr 408: if (($ConnectionCount == 0) && ($Requests > 0)) {
409: if ($ConnectionRetriesLeft > 0) {
410: my $Connections = ($Requests <= $MaxConnectionCount) ?
411: $Requests : $MaxConnectionCount;
1.29 ! foxr 412: Debug(5,"Work but no connections, start ".$Connections." of them");
1.22 foxr 413: my $successCount = 0;
1.23 foxr 414: for (my $i =0; $i < $Connections; $i++) {
1.22 foxr 415: $successCount += MakeLondConnection();
416: }
417: if($successCount == 0) { # All connections failed:
1.29 ! foxr 418: Debug(5,"Work in queue failed to make any connectiouns\n");
1.22 foxr 419: EmptyQueue(); # Fail pending transactions with con_lost.
1.10 foxr 420: }
421: } else {
1.22 foxr 422: ShowStatus(GetServerHost()." >>> DEAD!!! <<<");
1.29 ! foxr 423: Debug(5,"Work in queue, but gave up on connections..flushing\n");
1.10 foxr 424: EmptyQueue(); # Connections can't be established.
1.5 foxr 425: }
426:
427: }
1.1 foxr 428: }
429:
430: =pod
1.3 albertel 431:
1.1 foxr 432: =head2 SetupTimer
433:
1.3 albertel 434: Sets up a 1 per sec recurring timer event. The event handler is used to:
1.1 foxr 435:
1.3 albertel 436: =item
437:
438: Trigger timeouts on communications along active sockets.
439:
440: =item
441:
442: Trigger disconnections of idle sockets.
1.1 foxr 443:
444: =cut
445:
446: sub SetupTimer {
447: Debug(6, "SetupTimer");
448: Event->timer(interval => 1, debug => 1, cb => \&Tick );
449: }
1.3 albertel 450:
1.1 foxr 451: =pod
1.3 albertel 452:
1.1 foxr 453: =head2 ServerToIdle
1.3 albertel 454:
455: This function is called when a connection to the server is
456: ready for more work.
457:
458: If there is work in the Work queue the top element is dequeued
1.1 foxr 459: and the connection will start to work on it. If the work queue is
460: empty, the connection is pushed on the idle connection stack where
461: it will either get another work unit, or alternatively, if it sits there
462: long enough, it will be shut down and released.
463:
1.3 albertel 464: =cut
1.1 foxr 465:
466: sub ServerToIdle {
467: my $Socket = shift; # Get the socket.
1.7 foxr 468: delete($ActiveTransactions{$Socket}); # Server has no transaction
1.1 foxr 469:
1.29 ! foxr 470: &Debug(5, "Server to idle");
1.1 foxr 471:
472: # If there's work to do, start the transaction:
473:
1.23 foxr 474: my $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
1.29 ! foxr 475: if ($reqdata ne undef) {
! 476: Debug(5, "Queue gave request data: ".$reqdata->getRequest());
1.7 foxr 477: &StartRequest($Socket, $reqdata);
1.8 foxr 478:
1.1 foxr 479: } else {
480:
481: # There's no work waiting, so push the server to idle list.
1.29 ! foxr 482: &Debug(5, "No new work requests, server connection going idle");
1.1 foxr 483: $IdleConnections->push($Socket);
484: }
485: }
1.3 albertel 486:
1.1 foxr 487: =pod
1.3 albertel 488:
1.1 foxr 489: =head2 ClientWritable
1.3 albertel 490:
491: Event callback for when a client socket is writable.
492:
493: This callback is established when a transaction reponse is
494: avaiable from lond. The response is forwarded to the unix socket
495: as it becomes writable in this sub.
496:
1.1 foxr 497: Parameters:
498:
1.3 albertel 499: =item Event
500:
501: The event that has been triggered. Event->w->data is
502: the data and Event->w->fd is the socket to write.
1.1 foxr 503:
504: =cut
1.3 albertel 505:
1.1 foxr 506: sub ClientWritable {
507: my $Event = shift;
508: my $Watcher = $Event->w;
509: my $Data = $Watcher->data;
510: my $Socket = $Watcher->fd;
511:
512: # Try to send the data:
513:
514: &Debug(6, "ClientWritable writing".$Data);
515: &Debug(9, "Socket is: ".$Socket);
516:
1.6 foxr 517: if($Socket->connected) {
518: my $result = $Socket->send($Data, 0);
519:
520: # $result undefined: the write failed.
521: # otherwise $result is the number of bytes written.
522: # Remove that preceding string from the data.
523: # If the resulting data is empty, destroy the watcher
524: # and set up a read event handler to accept the next
525: # request.
526:
527: &Debug(9,"Send result is ".$result." Defined: ".defined($result));
1.29 ! foxr 528: if($result ne undef) {
1.6 foxr 529: &Debug(9, "send result was defined");
530: if($result == length($Data)) { # Entire string sent.
531: &Debug(9, "ClientWritable data all written");
532: $Watcher->cancel();
533: #
534: # Set up to read next request from socket:
535:
536: my $descr = sprintf("Connection to lonc client %d",
537: $ActiveClients{$Socket});
538: Event->io(cb => \&ClientRequest,
539: poll => 'r',
540: desc => $descr,
541: data => "",
542: fd => $Socket);
543:
544: } else { # Partial string sent.
545: $Watcher->data(substr($Data, $result));
1.15 foxr 546: if($result == 0) { # client hung up on us!!
547: Log("INFO", "lonc pipe client hung up on us!");
548: $Watcher->cancel;
549: $Socket->shutdown(2);
550: $Socket->close();
551: }
1.6 foxr 552: }
553:
554: } else { # Error of some sort...
555:
556: # Some errnos are possible:
557: my $errno = $!;
558: if($errno == POSIX::EWOULDBLOCK ||
559: $errno == POSIX::EAGAIN ||
560: $errno == POSIX::EINTR) {
561: # No action taken?
562: } else { # Unanticipated errno.
563: &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
564: $Watcher->cancel; # Stop the watcher.
565: $Socket->shutdown(2); # Kill connection
566: $Socket->close(); # Close the socket.
567: }
1.1 foxr 568:
569: }
1.6 foxr 570: } else {
571: $Watcher->cancel(); # A delayed request...just cancel.
1.1 foxr 572: }
573: }
574:
575: =pod
1.3 albertel 576:
1.1 foxr 577: =head2 CompleteTransaction
1.3 albertel 578:
579: Called when the reply data has been received for a lond
1.1 foxr 580: transaction. The reply data must now be sent to the
581: ultimate client on the other end of the Unix socket. This is
582: done by setting up a writable event for the socket with the
583: data the reply data.
1.3 albertel 584:
1.1 foxr 585: Parameters:
1.3 albertel 586:
587: =item Socket
588:
589: Socket on which the lond transaction occured. This is a
590: LondConnection. The data received is in the TransactionReply member.
591:
1.7 foxr 592: =item Transaction
1.3 albertel 593:
1.7 foxr 594: The transaction that is being completed.
1.1 foxr 595:
596: =cut
1.3 albertel 597:
1.1 foxr 598: sub CompleteTransaction {
1.29 ! foxr 599: &Debug(5,"Complete transaction");
1.1 foxr 600: my $Socket = shift;
1.7 foxr 601: my $Transaction = shift;
1.1 foxr 602:
1.7 foxr 603: if (!$Transaction->isDeferred()) { # Normal transaction
604: my $data = $Socket->GetReply(); # Data to send.
605: StartClientReply($Transaction, $data);
606: } else { # Delete deferred transaction file.
1.9 foxr 607: Log("SUCCESS", "A delayed transaction was completed");
1.23 foxr 608: LogPerm("S:$Transaction->getClient() :".$Transaction->getRequest());
1.7 foxr 609: unlink $Transaction->getFile();
610: }
1.6 foxr 611: }
612: =pod
613: =head1 StartClientReply
614:
615: Initiates a reply to a client where the reply data is a parameter.
616:
1.7 foxr 617: =head2 parameters:
618:
619: =item Transaction
620:
621: The transaction for which we are responding to the client.
622:
623: =item data
624:
625: The data to send to apached client.
626:
1.6 foxr 627: =cut
628: sub StartClientReply {
1.7 foxr 629: my $Transaction = shift;
1.6 foxr 630: my $data = shift;
1.1 foxr 631:
1.12 foxr 632:
1.7 foxr 633: my $Client = $Transaction->getClient();
634:
1.1 foxr 635: &Debug(8," Reply was: ".$data);
636: my $Serial = $ActiveClients{$Client};
637: my $desc = sprintf("Connection to lonc client %d",
638: $Serial);
639: Event->io(fd => $Client,
640: poll => "w",
641: desc => $desc,
642: cb => \&ClientWritable,
643: data => $data);
644: }
1.4 foxr 645: =pod
646: =head2 FailTransaction
647:
648: Finishes a transaction with failure because the associated lond socket
1.7 foxr 649: disconnected. There are two possibilities:
650: - The transaction is deferred: in which case we just quietly
651: delete the transaction since there is no client connection.
652: - The transaction is 'live' in which case we initiate the sending
653: of "con_lost" to the client.
654:
655: Deleting the transaction means killing it from the
656: %ActiveTransactions hash.
1.4 foxr 657:
658: Parameters:
659:
660: =item client
661:
1.7 foxr 662: The LondTransaction we are failing.
663:
1.4 foxr 664: =cut
665:
666: sub FailTransaction {
1.7 foxr 667: my $transaction = shift;
1.17 foxr 668: Log("WARNING", "Failing transaction ".$transaction->getRequest());
1.29 ! foxr 669: Debug(5, "Failing transaction: ".$transaction->getRequest());
1.10 foxr 670: if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
1.11 foxr 671: my $client = $transaction->getClient();
1.29 ! foxr 672: Debug(5," Replying con_lost to ".$transaction->getRequest());
1.11 foxr 673: StartClientReply($transaction, "con_lost\n");
1.7 foxr 674: }
1.22 foxr 675: if($ConnectionRetriesLeft <= 0) {
676: Log("CRITICAL", "Host marked dead: ".GetServerHost());
677: }
1.4 foxr 678:
679: }
680:
681: =pod
1.6 foxr 682: =head1 EmptyQueue
1.7 foxr 683:
1.6 foxr 684: Fails all items in the work queue with con_lost.
1.7 foxr 685: Note that each item in the work queue is a transaction.
686:
1.6 foxr 687: =cut
688: sub EmptyQueue {
1.22 foxr 689: $ConnectionRetriesLeft--; # Counts as connection failure too.
1.6 foxr 690: while($WorkQueue->Count()) {
1.10 foxr 691: my $request = $WorkQueue->dequeue(); # This is a transaction
1.7 foxr 692: FailTransaction($request);
1.6 foxr 693: }
694: }
695:
696: =pod
1.4 foxr 697:
1.9 foxr 698: =head2 CloseAllLondConnections
699:
700: Close all connections open on lond prior to exit e.g.
701:
702: =cut
703: sub CloseAllLondConnections {
1.23 foxr 704: foreach my $Socket (keys %ActiveConnections) {
1.9 foxr 705: KillSocket($Socket);
706: }
707: }
708: =cut
709:
710: =pod
711:
1.4 foxr 712: =head2 KillSocket
713:
714: Destroys a socket. This function can be called either when a socket
715: has died of 'natural' causes or because a socket needs to be pruned due to
716: idleness. If the socket has died naturally, if there are no longer any
717: live connections a new connection is created (in case there are transactions
718: in the queue). If the socket has been pruned, it is never re-created.
719:
720: Parameters:
1.1 foxr 721:
1.4 foxr 722: =item Socket
723:
724: The socket to kill off.
725:
726: =item Restart
727:
728: nonzero if we are allowed to create a new connection.
729:
730:
731: =cut
732: sub KillSocket {
733: my $Socket = shift;
734:
1.17 foxr 735: Log("WARNING", "Shutting down a socket");
1.9 foxr 736: $Socket->Shutdown();
737:
1.7 foxr 738: # If the socket came from the active connection set,
739: # delete its transaction... note that FailTransaction should
740: # already have been called!!!
741: # otherwise it came from the idle set.
742: #
1.4 foxr 743:
744: if(exists($ActiveTransactions{$Socket})) {
745: delete ($ActiveTransactions{$Socket});
746: }
747: if(exists($ActiveConnections{$Socket})) {
748: delete($ActiveConnections{$Socket});
749: }
750: $ConnectionCount--;
1.6 foxr 751:
752: # If the connection count has gone to zero and there is work in the
753: # work queue, the work all gets failed with con_lost.
754: #
755: if($ConnectionCount == 0) {
1.22 foxr 756: EmptyQueue();
1.4 foxr 757: }
758: }
1.1 foxr 759:
760: =pod
1.3 albertel 761:
1.1 foxr 762: =head2 LondReadable
1.3 albertel 763:
1.1 foxr 764: This function is called whenever a lond connection
765: is readable. The action is state dependent:
766:
1.3 albertel 767: =head3 State=Initialized
768:
769: We''re waiting for the challenge, this is a no-op until the
1.1 foxr 770: state changes.
1.3 albertel 771:
1.1 foxr 772: =head3 State=Challenged
1.3 albertel 773:
774: The challenge has arrived we need to transition to Writable.
1.1 foxr 775: The connection must echo the challenge back.
1.3 albertel 776:
1.1 foxr 777: =head3 State=ChallengeReplied
1.3 albertel 778:
779: The challenge has been replied to. The we are receiveing the
1.1 foxr 780: 'ok' from the partner.
1.3 albertel 781:
1.1 foxr 782: =head3 State=RequestingKey
1.3 albertel 783:
784: The ok has been received and we need to send the request for
1.1 foxr 785: an encryption key. Transition to writable for that.
1.3 albertel 786:
1.1 foxr 787: =head3 State=ReceivingKey
1.3 albertel 788:
789: The the key has been requested, now we are reading the new key.
790:
1.1 foxr 791: =head3 State=Idle
1.3 albertel 792:
793: The encryption key has been negotiated or we have finished
1.1 foxr 794: reading data from the a transaction. If the callback data has
795: a client as well as the socket iformation, then we are
796: doing a transaction and the data received is relayed to the client
797: before the socket is put on the idle list.
1.3 albertel 798:
1.1 foxr 799: =head3 State=SendingRequest
1.3 albertel 800:
801: I do not think this state can be received here, but if it is,
1.1 foxr 802: the appropriate thing to do is to transition to writable, and send
803: the request.
1.3 albertel 804:
1.1 foxr 805: =head3 State=ReceivingReply
1.3 albertel 806:
807: We finished sending the request to the server and now transition
1.1 foxr 808: to readable to receive the reply.
809:
810: The parameter to this function are:
1.3 albertel 811:
1.1 foxr 812: The event. Implicit in this is the watcher and its data. The data
813: contains at least the lond connection object and, if a
814: transaction is in progress, the socket attached to the local client.
815:
1.3 albertel 816: =cut
1.1 foxr 817:
818: sub LondReadable {
1.8 foxr 819:
1.1 foxr 820: my $Event = shift;
821: my $Watcher = $Event->w;
822: my $Socket = $Watcher->data;
823: my $client = undef;
824:
1.23 foxr 825: &Debug(6,"LondReadable called state = ".$Socket->GetState());
1.8 foxr 826:
1.1 foxr 827:
828: my $State = $Socket->GetState(); # All action depends on the state.
829:
830: SocketDump(6, $Socket);
1.12 foxr 831: my $status = $Socket->Readable();
1.17 foxr 832:
1.12 foxr 833: &Debug(2, "Socket->Readable returned: $status");
1.1 foxr 834:
1.12 foxr 835: if($status != 0) {
1.4 foxr 836: # bad return from socket read. Currently this means that
837: # The socket has become disconnected. We fail the transaction.
838:
1.17 foxr 839: Log("WARNING",
840: "Lond connection lost.");
1.4 foxr 841: if(exists($ActiveTransactions{$Socket})) {
842: FailTransaction($ActiveTransactions{$Socket});
843: }
844: $Watcher->cancel();
1.6 foxr 845: KillSocket($Socket);
1.22 foxr 846: $ConnectionRetriesLeft--; # Counts as connection failure
1.4 foxr 847: return;
1.1 foxr 848: }
849: SocketDump(6,$Socket);
850:
851: $State = $Socket->GetState(); # Update in case of transition.
852: &Debug(6, "After read, state is ".$State);
853:
854: if($State eq "Initialized") {
855:
856:
857: } elsif ($State eq "ChallengeReceived") {
858: # The challenge must be echoed back; The state machine
859: # in the connection takes care of setting that up. Just
860: # need to transition to writable:
861:
1.8 foxr 862: $Watcher->cb(\&LondWritable);
1.1 foxr 863: $Watcher->poll("w");
864:
865: } elsif ($State eq "ChallengeReplied") {
866:
867:
868: } elsif ($State eq "RequestingKey") {
869: # The ok was received. Now we need to request the key
870: # That requires us to be writable:
871:
1.8 foxr 872: $Watcher->cb(\&LondWritable);
1.1 foxr 873: $Watcher->poll("w");
874:
875: } elsif ($State eq "ReceivingKey") {
876:
877: } elsif ($State eq "Idle") {
878: # If necessary, complete a transaction and then go into the
879: # idle queue.
1.22 foxr 880: # Note that a trasition to idle indicates a live lond
881: # on the other end so reset the connection retries.
882: #
883: $ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
1.8 foxr 884: $Watcher->cancel();
1.1 foxr 885: if(exists($ActiveTransactions{$Socket})) {
1.29 ! foxr 886: Debug(5,"Completing transaction!!");
1.1 foxr 887: CompleteTransaction($Socket,
888: $ActiveTransactions{$Socket});
1.9 foxr 889: } else {
890: Log("SUCCESS", "Connection ".$ConnectionCount." to "
891: .$RemoteHost." now ready for action");
1.1 foxr 892: }
893: ServerToIdle($Socket); # Next work unit or idle.
1.6 foxr 894:
1.1 foxr 895: } elsif ($State eq "SendingRequest") {
896: # We need to be writable for this and probably don't belong
897: # here inthe first place.
898:
899: Deubg(6, "SendingRequest state encountered in readable");
900: $Watcher->poll("w");
901: $Watcher->cb(\&LondWritable);
902:
903: } elsif ($State eq "ReceivingReply") {
904:
905:
906: } else {
907: # Invalid state.
908: Debug(4, "Invalid state in LondReadable");
909: }
910: }
1.3 albertel 911:
1.1 foxr 912: =pod
1.3 albertel 913:
1.1 foxr 914: =head2 LondWritable
1.3 albertel 915:
1.1 foxr 916: This function is called whenever a lond connection
917: becomes writable while there is a writeable monitoring
918: event. The action taken is very state dependent:
1.3 albertel 919:
1.1 foxr 920: =head3 State = Connected
1.3 albertel 921:
922: The connection is in the process of sending the 'init' hailing to the
923: lond on the remote end. The connection object''s Writable member is
924: called. On error, ConnectionError is called to destroy the connection
925: and remove it from the ActiveConnections hash
926:
1.1 foxr 927: =head3 Initialized
1.3 albertel 928:
929: 'init' has been sent, writability monitoring is removed and
930: readability monitoring is started with LondReadable as the callback.
931:
1.1 foxr 932: =head3 ChallengeReceived
1.3 albertel 933:
934: The connection has received the who are you challenge from the remote
935: system, and is in the process of sending the challenge
936: response. Writable is called.
937:
1.1 foxr 938: =head3 ChallengeReplied
1.3 albertel 939:
940: The connection has replied to the initial challenge The we switch to
941: monitoring readability looking for the server to reply with 'ok'.
942:
1.1 foxr 943: =head3 RequestingKey
1.3 albertel 944:
945: The connection is in the process of requesting its encryption key.
946: Writable is called.
947:
1.1 foxr 948: =head3 ReceivingKey
1.3 albertel 949:
950: The connection has sent the request for a key. Switch to readability
951: monitoring to accept the key
952:
1.1 foxr 953: =head3 SendingRequest
1.3 albertel 954:
955: The connection is in the process of sending a request to the server.
956: This request is part of a client transaction. All the states until
957: now represent the client setup protocol. Writable is called.
958:
1.1 foxr 959: =head3 ReceivingReply
960:
1.3 albertel 961: The connection has sent a request. Now it must receive a reply.
962: Readability monitoring is requested.
963:
964: This function is an event handler and therefore receives as
1.1 foxr 965: a parameter the event that has fired. The data for the watcher
966: of this event is a reference to a list of one or two elements,
967: depending on state. The first (and possibly only) element is the
968: socket. The second (present only if a request is in progress)
969: is the socket on which to return a reply to the caller.
970:
971: =cut
1.3 albertel 972:
1.1 foxr 973: sub LondWritable {
974: my $Event = shift;
975: my $Watcher = $Event->w;
1.8 foxr 976: my $Socket = $Watcher->data;
977: my $State = $Socket->GetState();
1.1 foxr 978:
1.8 foxr 979: Debug(6,"LondWritable State = ".$State."\n");
1.1 foxr 980:
1.8 foxr 981:
1.1 foxr 982: # Figure out what to do depending on the state of the socket:
983:
984:
985:
986:
987: SocketDump(6,$Socket);
988:
989: if ($State eq "Connected") {
990:
991: if ($Socket->Writable() != 0) {
992: # The write resulted in an error.
1.4 foxr 993: # We'll treat this as if the socket got disconnected:
1.9 foxr 994: Log("WARNING", "Connection to ".$RemoteHost.
995: " has been disconnected");
1.18 foxr 996: FailTransaction($ActiveTransactions{$Socket});
1.4 foxr 997: $Watcher->cancel();
1.6 foxr 998: KillSocket($Socket);
1.4 foxr 999: return;
1.1 foxr 1000: }
1.4 foxr 1001: # "init" is being sent...
1002:
1.1 foxr 1003:
1004: } elsif ($State eq "Initialized") {
1005:
1006: # Now that init was sent, we switch
1007: # to watching for readability:
1008:
1.8 foxr 1009: $Watcher->cb(\&LondReadable);
1.1 foxr 1010: $Watcher->poll("r");
1011:
1012: } elsif ($State eq "ChallengeReceived") {
1013: # We received the challenge, now we
1014: # are echoing it back. This is a no-op,
1015: # we're waiting for the state to change
1016:
1017: if($Socket->Writable() != 0) {
1.5 foxr 1018:
1019: $Watcher->cancel();
1.6 foxr 1020: KillSocket($Socket);
1.5 foxr 1021: return;
1.1 foxr 1022: }
1023:
1024: } elsif ($State eq "ChallengeReplied") {
1025: # The echo was sent back, so we switch
1026: # to watching readability.
1027:
1.8 foxr 1028: $Watcher->cb(\&LondReadable);
1.1 foxr 1029: $Watcher->poll("r");
1030:
1031: } elsif ($State eq "RequestingKey") {
1032: # At this time we're requesting the key.
1033: # again, this is essentially a no-op.
1034: # we'll write the next chunk until the
1035: # state changes.
1036:
1037: if($Socket->Writable() != 0) {
1038: # Write resulted in an error.
1.5 foxr 1039:
1040: $Watcher->cancel();
1.6 foxr 1041: KillSocket($Socket);
1.5 foxr 1042: return;
1043:
1.1 foxr 1044: }
1045: } elsif ($State eq "ReceivingKey") {
1046: # Now we need to wait for the key
1047: # to come back from the peer:
1048:
1.8 foxr 1049: $Watcher->cb(\&LondReadable);
1.1 foxr 1050: $Watcher->poll("r");
1051:
1052: } elsif ($State eq "SendingRequest") {
1053: # At this time we are sending a request to the
1054: # peer... write the next chunk:
1055:
1056: if($Socket->Writable() != 0) {
1057:
1.5 foxr 1058: if(exists($ActiveTransactions{$Socket})) {
1059: Debug(3, "Lond connection lost, failing transactions");
1060: FailTransaction($ActiveTransactions{$Socket});
1061: }
1062: $Watcher->cancel();
1.6 foxr 1063: KillSocket($Socket);
1.5 foxr 1064: return;
1065:
1.1 foxr 1066: }
1067:
1068: } elsif ($State eq "ReceivingReply") {
1069: # The send has completed. Wait for the
1070: # data to come in for a reply.
1071: Debug(8,"Writable sent request/receiving reply");
1.8 foxr 1072: $Watcher->cb(\&LondReadable);
1.1 foxr 1073: $Watcher->poll("r");
1074:
1075: } else {
1076: # Control only passes here on an error:
1077: # the socket state does not match any
1078: # of the known states... so an error
1079: # must be logged.
1080:
1081: &Debug(4, "Invalid socket state ".$State."\n");
1082: }
1083:
1084: }
1.6 foxr 1085: =pod
1086:
1087: =cut
1088: sub QueueDelayed {
1.8 foxr 1089: Debug(3,"QueueDelayed called");
1090:
1.6 foxr 1091: my $path = "$perlvar{'lonSockDir'}/delayed";
1.8 foxr 1092:
1093: Debug(4, "Delayed path: ".$path);
1.6 foxr 1094: opendir(DIRHANDLE, $path);
1.8 foxr 1095:
1.23 foxr 1096: my @alldelayed = grep /\.$RemoteHost$/, readdir DIRHANDLE;
1.6 foxr 1097: closedir(DIRHANDLE);
1098: my $dfname;
1.8 foxr 1099: my $reqfile;
1100: foreach $dfname (sort @alldelayed) {
1101: $reqfile = "$path/$dfname";
1102: Debug(4, "queueing ".$reqfile);
1.6 foxr 1103: my $Handle = IO::File->new($reqfile);
1104: my $cmd = <$Handle>;
1.8 foxr 1105: chomp $cmd; # There may or may not be a newline...
1.12 foxr 1106: $cmd = $cmd."\n"; # now for sure there's exactly one newline.
1.7 foxr 1107: my $Transaction = LondTransaction->new($cmd);
1108: $Transaction->SetDeferred($reqfile);
1109: QueueTransaction($Transaction);
1.6 foxr 1110: }
1111:
1112: }
1.1 foxr 1113:
1114: =pod
1.3 albertel 1115:
1.1 foxr 1116: =head2 MakeLondConnection
1.3 albertel 1117:
1118: Create a new lond connection object, and start it towards its initial
1119: idleness. Once idle, it becomes elligible to receive transactions
1120: from the work queue. If the work queue is not empty when the
1121: connection is completed and becomes idle, it will dequeue an entry and
1122: start off on it.
1123:
1.1 foxr 1124: =cut
1.3 albertel 1125:
1.1 foxr 1126: sub MakeLondConnection {
1127: Debug(4,"MakeLondConnection to ".GetServerHost()." on port "
1128: .GetServerPort());
1129:
1130: my $Connection = LondConnection->new(&GetServerHost(),
1131: &GetServerPort());
1132:
1133: if($Connection == undef) { # Needs to be more robust later.
1.9 foxr 1134: Log("CRITICAL","Failed to make a connection with lond.");
1.10 foxr 1135: $ConnectionRetriesLeft--;
1136: return 0; # Failure.
1.5 foxr 1137: } else {
1.22 foxr 1138:
1.5 foxr 1139: # The connection needs to have writability
1140: # monitored in order to send the init sequence
1141: # that starts the whole authentication/key
1142: # exchange underway.
1143: #
1144: my $Socket = $Connection->GetSocket();
1145: if($Socket == undef) {
1146: die "did not get a socket from the connection";
1147: } else {
1148: &Debug(9,"MakeLondConnection got socket: ".$Socket);
1149: }
1.1 foxr 1150:
1.21 foxr 1151: $Connection->SetTimeoutCallback(\&SocketTimeout);
1152:
1.23 foxr 1153: my $event = Event->io(fd => $Socket,
1.5 foxr 1154: poll => 'w',
1155: cb => \&LondWritable,
1.8 foxr 1156: data => $Connection,
1.5 foxr 1157: desc => 'Connection to lond server');
1158: $ActiveConnections{$Connection} = $event;
1159:
1160: $ConnectionCount++;
1.8 foxr 1161: Debug(4, "Connection count = ".$ConnectionCount);
1.6 foxr 1162: if($ConnectionCount == 1) { # First Connection:
1163: QueueDelayed;
1164: }
1.9 foxr 1165: Log("SUCESS", "Created connection ".$ConnectionCount
1166: ." to host ".GetServerHost());
1.10 foxr 1167: return 1; # Return success.
1.1 foxr 1168: }
1169:
1170: }
1.3 albertel 1171:
1.1 foxr 1172: =pod
1.3 albertel 1173:
1.1 foxr 1174: =head2 StartRequest
1.3 albertel 1175:
1176: Starts a lond request going on a specified lond connection.
1177: parameters are:
1178:
1179: =item $Lond
1180:
1181: Connection to the lond that will send the transaction and receive the
1182: reply.
1183:
1184: =item $Client
1185:
1186: Connection to the client that is making this request We got the
1187: request from this socket, and when the request has been relayed to
1188: lond and we get a reply back from lond it will get sent to this
1189: socket.
1190:
1191: =item $Request
1192:
1193: The text of the request to send.
1194:
1.1 foxr 1195: =cut
1196:
1197: sub StartRequest {
1198: my $Lond = shift;
1.7 foxr 1199: my $Request = shift; # This is a LondTransaction.
1.1 foxr 1200:
1.7 foxr 1201: Debug(6, "StartRequest: ".$Request->getRequest());
1.1 foxr 1202:
1203: my $Socket = $Lond->GetSocket();
1204:
1.7 foxr 1205: $Request->Activate($Lond);
1206: $ActiveTransactions{$Lond} = $Request;
1.1 foxr 1207:
1.7 foxr 1208: $Lond->InitiateTransaction($Request->getRequest());
1.23 foxr 1209: my $event = Event->io(fd => $Socket,
1.1 foxr 1210: poll => "w",
1211: cb => \&LondWritable,
1212: data => $Lond,
1213: desc => "lond transaction connection");
1214: $ActiveConnections{$Lond} = $event;
1215: Debug(8," Start Request made watcher data with ".$event->data."\n");
1216: }
1217:
1218: =pod
1.3 albertel 1219:
1.1 foxr 1220: =head2 QueueTransaction
1.3 albertel 1221:
1222: If there is an idle lond connection, it is put to work doing this
1223: transaction. Otherwise, the transaction is placed in the work queue.
1224: If placed in the work queue and the maximum number of connections has
1225: not yet been created, a new connection will be started. Our goal is
1226: to eventually have a sufficient number of connections that the work
1227: queue will typically be empty. parameters are:
1228:
1229: =item Socket
1230:
1231: open on the lonc client.
1232:
1233: =item Request
1234:
1235: data to send to the lond.
1.1 foxr 1236:
1237: =cut
1.3 albertel 1238:
1.1 foxr 1239: sub QueueTransaction {
1240:
1.7 foxr 1241: my $requestData = shift; # This is a LondTransaction.
1242: my $cmd = $requestData->getRequest();
1243:
1244: Debug(6,"QueueTransaction: ".$cmd);
1.1 foxr 1245:
1246: my $LondSocket = $IdleConnections->pop();
1247: if(!defined $LondSocket) { # Need to queue request.
1.29 ! foxr 1248: Debug(5,"Must queue...");
1.1 foxr 1249: $WorkQueue->enqueue($requestData);
1250: if($ConnectionCount < $MaxConnectionCount) {
1.22 foxr 1251: if($ConnectionRetriesLeft > 0) {
1.29 ! foxr 1252: Debug(5,"Starting additional lond connection");
1.22 foxr 1253: if(MakeLondConnection() == 0) {
1254: EmptyQueue(); # Fail transactions, can't make connection.
1255: }
1256: } else {
1257: ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
1258: EmptyQueue(); # It's worse than that ... he's dead Jim.
1.17 foxr 1259: }
1.1 foxr 1260: }
1261: } else { # Can start the request:
1262: Debug(8,"Can start...");
1.7 foxr 1263: StartRequest($LondSocket, $requestData);
1.1 foxr 1264: }
1265: }
1266:
1267: #-------------------------- Lonc UNIX socket handling ---------------------
1.3 albertel 1268:
1.1 foxr 1269: =pod
1.3 albertel 1270:
1.1 foxr 1271: =head2 ClientRequest
1.3 albertel 1272: Callback that is called when data can be read from the UNIX domain
1273: socket connecting us with an apache server process.
1.1 foxr 1274:
1275: =cut
1276:
1277: sub ClientRequest {
1278: Debug(6, "ClientRequest");
1279: my $event = shift;
1280: my $watcher = $event->w;
1281: my $socket = $watcher->fd;
1282: my $data = $watcher->data;
1283: my $thisread;
1284:
1285: Debug(9, " Watcher named: ".$watcher->desc);
1286:
1287: my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
1288: Debug(8, "rcv: data length = ".length($thisread)
1289: ." read =".$thisread);
1.29 ! foxr 1290: unless (defined $rv && length($thisread)) {
1.1 foxr 1291: # Likely eof on socket.
1292: Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
1293: close($socket);
1294: $watcher->cancel();
1295: delete($ActiveClients{$socket});
1.10 foxr 1296: return;
1.1 foxr 1297: }
1298: Debug(8,"Data: ".$data." this read: ".$thisread);
1299: $data = $data.$thisread; # Append new data.
1300: $watcher->data($data);
1301: if($data =~ /(.*\n)/) { # Request entirely read.
1.10 foxr 1302: if($data eq "close_connection_exit\n") {
1.9 foxr 1303: Log("CRITICAL",
1304: "Request Close Connection ... exiting");
1305: CloseAllLondConnections();
1306: exit;
1307: }
1.1 foxr 1308: Debug(8, "Complete transaction received: ".$data);
1.8 foxr 1309: my $Transaction = LondTransaction->new($data);
1.7 foxr 1310: $Transaction->SetClient($socket);
1311: QueueTransaction($Transaction);
1.1 foxr 1312: $watcher->cancel(); # Done looking for input data.
1313: }
1314:
1315: }
1316:
1317:
1318: =pod
1.3 albertel 1319:
1.1 foxr 1320: =head2 NewClient
1.3 albertel 1321:
1322: Callback that is called when a connection is received on the unix
1323: socket for a new client of lonc. The callback is parameterized by the
1324: event.. which is a-priori assumed to be an io event, and therefore has
1325: an fd member that is the Listener socket. We Accept the connection
1326: and register a new event on the readability of that socket:
1327:
1.1 foxr 1328: =cut
1.3 albertel 1329:
1.1 foxr 1330: sub NewClient {
1331: Debug(6, "NewClient");
1332: my $event = shift; # Get the event parameters.
1333: my $watcher = $event->w;
1334: my $socket = $watcher->fd; # Get the event' socket.
1335: my $connection = $socket->accept(); # Accept the client connection.
1336: Debug(8,"Connection request accepted from "
1337: .GetPeername($connection, AF_UNIX));
1338:
1339:
1340: my $description = sprintf("Connection to lonc client %d",
1341: $ClientConnection);
1342: Debug(9, "Creating event named: ".$description);
1343: Event->io(cb => \&ClientRequest,
1344: poll => 'r',
1345: desc => $description,
1346: data => "",
1347: fd => $connection);
1348: $ActiveClients{$connection} = $ClientConnection;
1349: $ClientConnection++;
1350: }
1.3 albertel 1351:
1352: =pod
1353:
1354: =head2 GetLoncSocketPath
1355:
1356: Returns the name of the UNIX socket on which to listen for client
1357: connections.
1.1 foxr 1358:
1359: =cut
1.3 albertel 1360:
1.1 foxr 1361: sub GetLoncSocketPath {
1362: return $UnixSocketDir."/".GetServerHost();
1363: }
1364:
1.3 albertel 1365: =pod
1366:
1367: =head2 GetServerHost
1368:
1369: Returns the host whose lond we talk with.
1370:
1.1 foxr 1371: =cut
1.3 albertel 1372:
1.7 foxr 1373: sub GetServerHost {
1.1 foxr 1374: return $RemoteHost; # Setup by the fork.
1375: }
1.3 albertel 1376:
1377: =pod
1378:
1379: =head2 GetServerPort
1380:
1381: Returns the lond port number.
1382:
1.1 foxr 1383: =cut
1.3 albertel 1384:
1.7 foxr 1385: sub GetServerPort {
1.1 foxr 1386: return $perlvar{londPort};
1387: }
1.3 albertel 1388:
1389: =pod
1390:
1391: =head2 SetupLoncListener
1392:
1393: Setup a lonc listener event. The event is called when the socket
1394: becomes readable.. that corresponds to the receipt of a new
1395: connection. The event handler established will accept the connection
1396: (creating a communcations channel), that int turn will establish
1397: another event handler to subess requests.
1.1 foxr 1398:
1399: =cut
1.3 albertel 1400:
1.1 foxr 1401: sub SetupLoncListener {
1402:
1403: my $socket;
1404: my $SocketName = GetLoncSocketPath();
1405: unlink($SocketName);
1.7 foxr 1406: unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,
1.1 foxr 1407: Listen => 10,
1408: Type => SOCK_STREAM)) {
1409: die "Failed to create a lonc listner socket";
1410: }
1411: Event->io(cb => \&NewClient,
1412: poll => 'r',
1413: desc => 'Lonc listener Unix Socket',
1414: fd => $socket);
1415: }
1416:
1.14 foxr 1417: =pod
1418:
1419: =head2 ChildStatus
1420:
1421: Child USR1 signal handler to report the most recent status
1422: into the status file.
1423:
1.22 foxr 1424: We also use this to reset the retries count in order to allow the
1425: client to retry connections with a previously dead server.
1.14 foxr 1426: =cut
1427: sub ChildStatus {
1428: my $event = shift;
1429: my $watcher = $event->w;
1430:
1431: Debug(2, "Reporting child status because : ".$watcher->data);
1432: my $docdir = $perlvar{'lonDocRoot'};
1433: my $fh = IO::File->new(">>$docdir/lon-status/loncstatus.txt");
1434: print $fh $$."\t".$RemoteHost."\t".$Status."\t".
1435: $RecentLogEntry."\n";
1.22 foxr 1436: $ConnectionRetriesLeft = $ConnectionRetries;
1.14 foxr 1437: }
1438:
1.1 foxr 1439: =pod
1.3 albertel 1440:
1.10 foxr 1441: =head2 SignalledToDeath
1442:
1443: Called in response to a signal that causes a chid process to die.
1444:
1445: =cut
1446:
1447:
1448: sub SignalledToDeath {
1.14 foxr 1449: my $event = shift;
1450: my $watcher= $event->w;
1451:
1452: Debug(2,"Signalled to death! via ".$watcher->data);
1.17 foxr 1453: my ($signal) = $watcher->data;
1.10 foxr 1454: chomp($signal);
1455: Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "
1456: ."died through "."\"$signal\"");
1457: LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
1458: ."\"$signal\"");
1.12 foxr 1459: exit 0;
1.10 foxr 1460:
1461: }
1.16 foxr 1462:
1463: =head2 ToggleDebug
1464:
1465: This sub toggles trace debugging on and off.
1466:
1467: =cut
1468:
1469: sub ToggleDebug {
1470: my $Current = $DebugLevel;
1471: $DebugLevel = $NextDebugLevel;
1472: $NextDebugLevel = $Current;
1473:
1474: Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel");
1475:
1476: }
1477:
1.1 foxr 1478: =head2 ChildProcess
1479:
1480: This sub implements a child process for a single lonc daemon.
1481:
1482: =cut
1483:
1484: sub ChildProcess {
1485:
1486:
1.14 foxr 1487: #
1488: # Signals must be handled by the Event framework...
1489: #
1490:
1491: Event->signal(signal => "QUIT",
1492: cb => \&SignalledToDeath,
1493: data => "QUIT");
1494: Event->signal(signal => "HUP",
1495: cb => \&ChildStatus,
1496: data => "HUP");
1497: Event->signal(signal => "USR1",
1498: cb => \&ChildStatus,
1499: data => "USR1");
1.16 foxr 1500: Event->signal(signal => "INT",
1501: cb => \&ToggleDebug,
1502: data => "INT");
1.1 foxr 1503:
1504: SetupTimer();
1505:
1506: SetupLoncListener();
1507:
1508: $Event::Debuglevel = $DebugLevel;
1509:
1510: Debug(9, "Making initial lond connection for ".$RemoteHost);
1511:
1512: # Setup the initial server connection:
1513:
1.14 foxr 1514: # &MakeLondConnection(); // let first work requirest do it.
1.10 foxr 1515:
1.5 foxr 1516:
1.1 foxr 1517: Debug(9,"Entering event loop");
1518: my $ret = Event::loop(); # Start the main event loop.
1519:
1520:
1521: die "Main event loop exited!!!";
1522: }
1523:
1524: # Create a new child for host passed in:
1525:
1526: sub CreateChild {
1.12 foxr 1527: my $sigset = POSIX::SigSet->new(SIGINT);
1528: sigprocmask(SIG_BLOCK, $sigset);
1.1 foxr 1529: my $host = shift;
1530: $RemoteHost = $host;
1.9 foxr 1531: Log("CRITICAL", "Forking server for ".$host);
1.23 foxr 1532: my $pid = fork;
1.1 foxr 1533: if($pid) { # Parent
1.17 foxr 1534: $RemoteHost = "Parent";
1.27 foxr 1535: $ChildHash{$pid} = $host;
1.26 foxr 1536: $HostToPid{$host}= $pid;
1.12 foxr 1537: sigprocmask(SIG_UNBLOCK, $sigset);
1538:
1.1 foxr 1539: } else { # child.
1.5 foxr 1540: ShowStatus("Connected to ".$RemoteHost);
1.23 foxr 1541: $SIG{INT} = 'DEFAULT';
1.12 foxr 1542: sigprocmask(SIG_UNBLOCK, $sigset);
1543: ChildProcess; # Does not return.
1.1 foxr 1544: }
1545:
1546: }
1547: #
1548: # Parent process logic pass 1:
1549: # For each entry in the hosts table, we will
1550: # fork off an instance of ChildProcess to service the transactions
1551: # to that host. Each pid will be entered in a global hash
1552: # with the value of the key, the host.
1553: # The parent will then enter a loop to wait for process exits.
1554: # Each exit gets logged and the child gets restarted.
1555: #
1556:
1.5 foxr 1557: #
1558: # Fork and start in new session so hang-up isn't going to
1559: # happen without intent.
1560: #
1561:
1562:
1.6 foxr 1563:
1564:
1.8 foxr 1565:
1.6 foxr 1566:
1567: ShowStatus("Forming new session");
1568: my $childpid = fork;
1569: if ($childpid != 0) {
1570: sleep 4; # Give child a chacne to break to
1571: exit 0; # a new sesion.
1572: }
1.8 foxr 1573: #
1574: # Write my pid into the pid file so I can be located
1575: #
1576:
1577: ShowStatus("Parent writing pid file:");
1.23 foxr 1578: my $execdir = $perlvar{'lonDaemons'};
1.8 foxr 1579: open (PIDSAVE, ">$execdir/logs/lonc.pid");
1580: print PIDSAVE "$$\n";
1581: close(PIDSAVE);
1.6 foxr 1582:
1.17 foxr 1583:
1584:
1.6 foxr 1585: if (POSIX::setsid() < 0) {
1586: print "Could not create new session\n";
1587: exit -1;
1588: }
1.5 foxr 1589:
1590: ShowStatus("Forking node servers");
1591:
1.9 foxr 1592: Log("CRITICAL", "--------------- Starting children ---------------");
1593:
1.1 foxr 1594: my $HostIterator = LondConnection::GetHostIterator;
1595: while (! $HostIterator->end()) {
1596:
1.23 foxr 1597: my $hostentryref = $HostIterator->get();
1.1 foxr 1598: CreateChild($hostentryref->[0]);
1.26 foxr 1599: $HostHash{$hostentryref->[0]} = $hostentryref->[4];
1.1 foxr 1600: $HostIterator->next();
1601: }
1.12 foxr 1602: $RemoteHost = "Parent Server";
1.1 foxr 1603:
1604: # Maintain the population:
1.5 foxr 1605:
1606: ShowStatus("Parent keeping the flock");
1.1 foxr 1607:
1.10 foxr 1608: #
1609: # Set up parent signals:
1610: #
1.12 foxr 1611:
1.14 foxr 1612: $SIG{INT} = \&Terminate;
1613: $SIG{TERM} = \&Terminate;
1.13 foxr 1614: $SIG{HUP} = \&Restart;
1.14 foxr 1615: $SIG{USR1} = \&CheckKids;
1.24 foxr 1616: $SIG{USR2} = \&UpdateKids; # LonManage update request.
1.10 foxr 1617:
1.1 foxr 1618: while(1) {
1.23 foxr 1619: my $deadchild = wait();
1.1 foxr 1620: if(exists $ChildHash{$deadchild}) { # need to restart.
1.23 foxr 1621: my $deadhost = $ChildHash{$deadchild};
1.26 foxr 1622: delete($HostToPid{$deadhost});
1.1 foxr 1623: delete($ChildHash{$deadchild});
1.9 foxr 1624: Log("WARNING","Lost child pid= ".$deadchild.
1.1 foxr 1625: "Connected to host ".$deadhost);
1.9 foxr 1626: Log("INFO", "Restarting child procesing ".$deadhost);
1.1 foxr 1627: CreateChild($deadhost);
1628: }
1.13 foxr 1629: }
1630:
1.14 foxr 1631:
1632:
1633: =pod
1634:
1635: =head1 CheckKids
1636:
1637: Since kids do not die as easily in this implementation
1638: as the previous one, there is no need to restart the
1639: dead ones (all dead kids get restarted when they die!!)
1640: The only thing this function does is to pass USR1 to the
1641: kids so that they report their status.
1642:
1643: =cut
1644:
1645: sub CheckKids {
1646: Debug(2, "Checking status of children");
1647: my $docdir = $perlvar{'lonDocRoot'};
1648: my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt");
1649: my $now=time;
1650: my $local=localtime($now);
1651: print $fh "LONC status $local - parent $$ \n\n";
1.23 foxr 1652: foreach my $pid (keys %ChildHash) {
1.14 foxr 1653: Debug(2, "Sending USR1 -> $pid");
1654: kill 'USR1' => $pid; # Tell Child to report status.
1655: sleep 1; # Wait so file doesn't intermix.
1656: }
1657: }
1.24 foxr 1658:
1659: =pod
1660:
1661: =head1 UpdateKids
1662:
1.25 foxr 1663: parent's SIGUSR2 handler. This handler:
1.24 foxr 1664:
1665: =item
1666:
1667: Rereads the hosts file.
1668:
1669: =item
1670:
1671: Kills off (via sigint) children for hosts that have disappeared.
1672:
1673: =item
1674:
1.27 foxr 1675: QUITs children for hosts that already exist (this just forces a status display
1.24 foxr 1676: and resets the connection retry count for that host.
1677:
1678: =item
1679:
1680: Starts new children for hosts that have been added to the hosts.tab file since
1681: the start of the master program and maintains them.
1682:
1683: =cut
1684:
1685: sub UpdateKids {
1.27 foxr 1686:
1.25 foxr 1687: Log("INFO", "Updating connections via SIGUSR2");
1.27 foxr 1688:
1689: # Just in case we need to kill our own lonc, we wait a few seconds to
1690: # give it a chance to receive and relay lond's response to the
1691: # re-init command.
1692: #
1693:
1694: sleep(2); # Wait a couple of seconds.
1695:
1696: my %hosts; # Indexed by loncapa hostname, value=ip.
1697:
1698: # Need to re-read the host table:
1699:
1700:
1701: LondConnection::ReadConfig();
1702: my $I = LondConnection::GetHostIterator;
1703: while (! $I->end()) {
1704: my $item = $I->get();
1705: $hosts{$item->[0]} = $item->[4];
1706: $I->next();
1707: }
1708:
1709: # The logic below is written for clarity not for efficiency.
1710: # Since I anticipate that this function is only rarely called, that's
1711: # appropriate. There are certainly ways to combine the loops below,
1712: # and anyone wishing to obscure the logic is welcome to go for it.
1713: # Note that we don't re-direct sigchild. Instead we do what's needed
1714: # to the data structures that keep track of children to ensure that
1715: # when sigchild is honored, no new child is born.
1716: #
1717:
1718: # For each existing child; if it's host doesn't exist, kill the child.
1719:
1720: foreach my $child (keys %ChildHash) {
1721: my $oldhost = $ChildHash{$child};
1722: if (!(exists $hosts{$oldhost})) {
1723: Log("CRITICAL", "Killing child for $oldhost host no longer exists");
1724: delete $ChildHash{$child};
1725: delete $HostToPid{$oldhost};
1726: kill 'QUIT' => $child;
1727: }
1728: }
1729: # For each remaining existing child; if it's host's ip has changed,
1730: # Restart the child on the new IP.
1731:
1732: foreach my $child (keys %ChildHash) {
1733: my $oldhost = $ChildHash{$child};
1734: my $oldip = $HostHash{$oldhost};
1735: if ($hosts{$oldhost} ne $oldip) {
1736:
1737: # kill the old child.
1738:
1739: Log("CRITICAL", "Killing child for $oldhost host ip has changed...");
1740: delete $ChildHash{$child};
1741: delete $HostToPid{$oldhost};
1742: kill 'QUIT' => $child;
1743:
1744: # Do the book-keeping needed to start a new child on the
1745: # new ip.
1746:
1747: $HostHash{$oldhost} = $hosts{$oldhost};
1748: CreateChild($oldhost);
1749: }
1750: }
1751: # Finally, for each new host, not in the host hash, create a
1752: # enter the host and create a new child.
1753: # Force a status display of any existing process.
1754:
1755: foreach my $host (keys %hosts) {
1756: if(!(exists $HostHash{$host})) {
1757: Log("INFO", "New host $host discovered in hosts.tab...");
1758: $HostHash{$host} = $hosts{$host};
1759: CreateChild($host);
1760: } else {
1761: kill 'HUP' => $HostToPid{$host}; # status display.
1762: }
1763: }
1.24 foxr 1764: }
1765:
1.14 foxr 1766:
1.13 foxr 1767: =pod
1768:
1769: =head1 Restart
1770:
1771: Signal handler for HUP... all children are killed and
1772: we self restart. This is an el-cheapo way to re read
1773: the config file.
1774:
1775: =cut
1776:
1777: sub Restart {
1.23 foxr 1778: &KillThemAll; # First kill all the children.
1.13 foxr 1779: Log("CRITICAL", "Restarting");
1780: my $execdir = $perlvar{'lonDaemons'};
1781: unlink("$execdir/logs/lonc.pid");
1.28 albertel 1782: exec("$execdir/loncnew");
1.10 foxr 1783: }
1.12 foxr 1784:
1785: =pod
1786:
1787: =head1 KillThemAll
1788:
1789: Signal handler that kills all children by sending them a
1.17 foxr 1790: SIGHUP. Responds to sigint and sigterm.
1.12 foxr 1791:
1792: =cut
1793:
1.10 foxr 1794: sub KillThemAll {
1.12 foxr 1795: Debug(2, "Kill them all!!");
1796: local($SIG{CHLD}) = 'IGNORE'; # Our children >will< die.
1.23 foxr 1797: foreach my $pid (keys %ChildHash) {
1.12 foxr 1798: my $serving = $ChildHash{$pid};
1799: Debug(2, "Killing lonc for $serving pid = $pid");
1800: ShowStatus("Killing lonc for $serving pid = $pid");
1801: Log("CRITICAL", "Killing lonc for $serving pid = $pid");
1.17 foxr 1802: kill 'QUIT' => $pid;
1803: delete($ChildHash{$pid});
1.12 foxr 1804: }
1.14 foxr 1805: my $execdir = $perlvar{'lonDaemons'};
1806: unlink("$execdir/logs/lonc.pid");
1.17 foxr 1807:
1.1 foxr 1808: }
1.12 foxr 1809:
1.14 foxr 1810: =pod
1811:
1812: =head1 Terminate
1813:
1814: Terminate the system.
1815:
1816: =cut
1817:
1818: sub Terminate {
1819: KillThemAll;
1.17 foxr 1820: Log("CRITICAL","Master process exiting");
1821: exit 0;
1.14 foxr 1822:
1823: }
1.12 foxr 1824: =pod
1.1 foxr 1825:
1826: =head1 Theory
1.3 albertel 1827:
1828: The event class is used to build this as a single process with an
1829: event driven model. The following events are handled:
1.1 foxr 1830:
1831: =item UNIX Socket connection Received
1832:
1833: =item Request data arrives on UNIX data transfer socket.
1834:
1835: =item lond connection becomes writable.
1836:
1837: =item timer fires at 1 second intervals.
1838:
1839: All sockets are run in non-blocking mode. Timeouts managed by the timer
1840: handler prevents hung connections.
1841:
1842: Key data structures:
1843:
1.3 albertel 1844: =item RequestQueue
1845:
1846: A queue of requests received from UNIX sockets that are
1847: waiting for a chance to be forwarded on a lond connection socket.
1848:
1849: =item ActiveConnections
1850:
1851: A hash of lond connections that have transactions in process that are
1852: available to be timed out.
1853:
1854: =item ActiveTransactions
1855:
1856: A hash indexed by lond connections that contain the client reply
1857: socket for each connection that has an active transaction on it.
1858:
1859: =item IdleConnections
1860:
1861: A hash of lond connections that have no work to do. These connections
1862: can be closed if they are idle for a long enough time.
1.1 foxr 1863:
1864: =cut
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