Annotation of loncom/loncnew, revision 1.64
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: #
1.64 ! foxr 5: # $Id: loncnew,v 1.63 2004/10/04 11:30:45 foxr Exp $
1.2 albertel 6: #
7: # Copyright Michigan State University Board of Trustees
8: #
9: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
1.17 foxr 10: ## LON-CAPA is free software; you can redistribute it and/or modify
1.2 albertel 11: # it under the terms of the GNU General Public License as published by
12: # the Free Software Foundation; either version 2 of the License, or
13: # (at your option) any later version.
14: #
15: # LON-CAPA is distributed in the hope that it will be useful,
16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18: # GNU General Public License for more details.
19: #
20: # You should have received a copy of the GNU General Public License
21: # along with LON-CAPA; if not, write to the Free Software
22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23: #
24: # /home/httpd/html/adm/gpl.txt
25: #
26: # http://www.lon-capa.org/
27: #
1.1 foxr 28: #
1.15 foxr 29: # new lonc handles n request out bver m connections to londs.
1.1 foxr 30: # This module is based on the Event class.
31: # Development iterations:
32: # - Setup basic event loop. (done)
33: # - Add timer dispatch. (done)
34: # - Add ability to accept lonc UNIX domain sockets. (done)
35: # - Add ability to create/negotiate lond connections (done).
1.7 foxr 36: # - Add general logic for dispatching requests and timeouts. (done).
37: # - Add support for the lonc/lond requests. (done).
1.38 foxr 38: # - Add logging/status monitoring. (done)
39: # - Add Signal handling - HUP restarts. USR1 status report. (done)
1.7 foxr 40: # - Add Configuration file I/O (done).
1.38 foxr 41: # - Add management/status request interface. (done)
1.8 foxr 42: # - Add deferred request capability. (done)
1.38 foxr 43: # - Detect transmission timeouts. (done)
1.7 foxr 44: #
45:
1.23 foxr 46: use strict;
1.1 foxr 47: use lib "/home/httpd/lib/perl/";
48: use Event qw(:DEFAULT );
49: use POSIX qw(:signal_h);
1.12 foxr 50: use POSIX;
1.1 foxr 51: use IO::Socket;
52: use IO::Socket::INET;
53: use IO::Socket::UNIX;
1.9 foxr 54: use IO::File;
1.6 foxr 55: use IO::Handle;
1.1 foxr 56: use Socket;
57: use Crypt::IDEA;
58: use LONCAPA::Queue;
59: use LONCAPA::Stack;
60: use LONCAPA::LondConnection;
1.7 foxr 61: use LONCAPA::LondTransaction;
1.1 foxr 62: use LONCAPA::Configuration;
63: use LONCAPA::HashIterator;
64:
65:
66: # Read the httpd configuration file to get perl variables
67: # normally set in apache modules:
68:
69: my $perlvarref = LONCAPA::Configuration::read_conf('loncapa.conf');
70: my %perlvar = %{$perlvarref};
71:
72: #
73: # parent and shared variables.
74:
75: my %ChildHash; # by pid -> host.
1.26 foxr 76: my %HostToPid; # By host -> pid.
77: my %HostHash; # by loncapaname -> IP.
1.62 foxr 78: my %listening_to; # Socket->host table for who the parent
79: # is listening to.
80: my %parent_dispatchers; # host-> listener watcher events.
1.1 foxr 81:
1.9 foxr 82: my $MaxConnectionCount = 10; # Will get from config later.
1.1 foxr 83: my $ClientConnection = 0; # Uniquifier for client events.
84:
1.9 foxr 85: my $DebugLevel = 0;
1.29 foxr 86: my $NextDebugLevel= 2; # So Sigint can toggle this.
1.50 albertel 87: my $IdleTimeout= 600; # Wait 10 minutes before pruning connections.
1.1 foxr 88:
1.39 foxr 89: my $LogTransactions = 0; # When True, all transactions/replies get logged.
90:
1.1 foxr 91: #
92: # The variables below are only used by the child processes.
93: #
94: my $RemoteHost; # Name of host child is talking to.
1.20 albertel 95: my $UnixSocketDir= $perlvar{'lonSockDir'};
1.1 foxr 96: my $IdleConnections = Stack->new(); # Set of idle connections
97: my %ActiveConnections; # Connections to the remote lond.
1.7 foxr 98: my %ActiveTransactions; # LondTransactions in flight.
1.1 foxr 99: my %ActiveClients; # Serial numbers of active clients by socket.
100: my $WorkQueue = Queue->new(); # Queue of pending transactions.
101: my $ConnectionCount = 0;
1.4 foxr 102: my $IdleSeconds = 0; # Number of seconds idle.
1.9 foxr 103: my $Status = ""; # Current status string.
1.14 foxr 104: my $RecentLogEntry = "";
1.30 foxr 105: my $ConnectionRetries=2; # Number of connection retries allowed.
106: my $ConnectionRetriesLeft=2; # Number of connection retries remaining.
1.40 foxr 107: my $LondVersion = "unknown"; # Version of lond we talk with.
1.49 foxr 108: my $KeyMode = ""; # e.g. ssl, local, insecure from last connect.
1.54 foxr 109: my $LondConnecting = 0; # True when a connection is being built.
1.1 foxr 110:
1.60 foxr 111:
112: # DO NOT SET THE NEXT VARIABLE TO NON ZERO!!!!!!!!!!!!!!!
113:
1.57 foxr 114: my $DieWhenIdle = 0; # When true children die when trimmed -> 0.
1.62 foxr 115: my $I_am_child = 0; # True if this is the child process.
1.57 foxr 116:
1.1 foxr 117: #
1.9 foxr 118: # The hash below gives the HTML format for log messages
119: # given a severity.
120: #
121: my %LogFormats;
122:
1.45 albertel 123: $LogFormats{"CRITICAL"} = "<font color='red'>CRITICAL: %s</font>";
124: $LogFormats{"SUCCESS"} = "<font color='green'>SUCCESS: %s</font>";
125: $LogFormats{"INFO"} = "<font color='yellow'>INFO: %s</font>";
126: $LogFormats{"WARNING"} = "<font color='blue'>WARNING: %s</font>";
1.9 foxr 127: $LogFormats{"DEFAULT"} = " %s ";
128:
1.10 foxr 129:
1.57 foxr 130: # UpdateStatus;
131: # Update the idle status display to show how many connections
132: # are left, retries and other stuff.
133: #
134: sub UpdateStatus {
135: if ($ConnectionRetriesLeft > 0) {
136: ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
137: ." Retries remaining: ".$ConnectionRetriesLeft
138: ." ($KeyMode)");
139: } else {
140: ShowStatus(GetServerHost()." >> DEAD <<");
141: }
142: }
143:
1.10 foxr 144:
145: =pod
146:
147: =head2 LogPerm
148:
149: Makes an entry into the permanent log file.
150:
151: =cut
152: sub LogPerm {
153: my $message=shift;
154: my $execdir=$perlvar{'lonDaemons'};
155: my $now=time;
156: my $local=localtime($now);
157: my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
158: print $fh "$now:$message:$local\n";
159: }
1.9 foxr 160:
161: =pod
162:
163: =head2 Log
164:
165: Logs a message to the log file.
166: Parameters:
167:
168: =item severity
169:
170: One of CRITICAL, WARNING, INFO, SUCCESS used to select the
171: format string used to format the message. if the severity is
172: not a defined severity the Default format string is used.
173:
174: =item message
175:
176: The base message. In addtion to the format string, the message
177: will be appended to a string containing the name of our remote
178: host and the time will be formatted into the message.
179:
180: =cut
181:
182: sub Log {
1.47 foxr 183:
184: my ($severity, $message) = @_;
185:
1.9 foxr 186: if(!$LogFormats{$severity}) {
187: $severity = "DEFAULT";
188: }
189:
190: my $format = $LogFormats{$severity};
191:
192: # Put the window dressing in in front of the message format:
193:
194: my $now = time;
195: my $local = localtime($now);
196: my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
197: my $finalformat = $finalformat.$format."\n";
198:
199: # open the file and put the result.
200:
201: my $execdir = $perlvar{'lonDaemons'};
202: my $fh = IO::File->new(">>$execdir/logs/lonc.log");
203: my $msg = sprintf($finalformat, $message);
1.14 foxr 204: $RecentLogEntry = $msg;
1.9 foxr 205: print $fh $msg;
206:
1.10 foxr 207:
1.9 foxr 208: }
1.6 foxr 209:
1.3 albertel 210:
1.1 foxr 211: =pod
1.3 albertel 212:
213: =head2 GetPeerName
214:
215: Returns the name of the host that a socket object is connected to.
216:
1.1 foxr 217: =cut
218:
219: sub GetPeername {
1.47 foxr 220:
221:
222: my ($connection, $AdrFamily) = @_;
223:
1.1 foxr 224: my $peer = $connection->peername();
225: my $peerport;
226: my $peerip;
227: if($AdrFamily == AF_INET) {
228: ($peerport, $peerip) = sockaddr_in($peer);
1.23 foxr 229: my $peername = gethostbyaddr($peerip, $AdrFamily);
1.1 foxr 230: return $peername;
231: } elsif ($AdrFamily == AF_UNIX) {
232: my $peerfile;
233: ($peerfile) = sockaddr_un($peer);
234: return $peerfile;
235: }
236: }
237: =pod
1.3 albertel 238:
1.1 foxr 239: =head2 Debug
1.3 albertel 240:
241: Invoked to issue a debug message.
242:
1.1 foxr 243: =cut
1.3 albertel 244:
1.1 foxr 245: sub Debug {
1.47 foxr 246:
247: my ($level, $message) = @_;
248:
1.1 foxr 249: if ($level <= $DebugLevel) {
1.23 foxr 250: Log("INFO", "-Debug- $message host = $RemoteHost");
1.1 foxr 251: }
252: }
253:
254: sub SocketDump {
1.47 foxr 255:
256: my ($level, $socket) = @_;
257:
1.1 foxr 258: if($level <= $DebugLevel) {
1.48 foxr 259: $socket->Dump(-1); # Ensure it will get dumped.
1.1 foxr 260: }
261: }
1.3 albertel 262:
1.1 foxr 263: =pod
1.3 albertel 264:
1.5 foxr 265: =head2 ShowStatus
266:
267: Place some text as our pid status.
1.10 foxr 268: and as what we return in a SIGUSR1
1.5 foxr 269:
270: =cut
271: sub ShowStatus {
1.10 foxr 272: my $state = shift;
273: my $now = time;
274: my $local = localtime($now);
275: $Status = $local.": ".$state;
276: $0='lonc: '.$state.' '.$local;
1.5 foxr 277: }
278:
279: =pod
280:
1.15 foxr 281: =head 2 SocketTimeout
282:
283: Called when an action on the socket times out. The socket is
284: destroyed and any active transaction is failed.
285:
286:
287: =cut
288: sub SocketTimeout {
289: my $Socket = shift;
1.38 foxr 290: Log("WARNING", "A socket timeout was detected");
1.52 foxr 291: Debug(5, " SocketTimeout called: ");
1.48 foxr 292: $Socket->Dump(0);
1.42 foxr 293: if(exists($ActiveTransactions{$Socket})) {
1.43 albertel 294: FailTransaction($ActiveTransactions{$Socket});
1.42 foxr 295: }
1.22 foxr 296: KillSocket($Socket); # A transaction timeout also counts as
297: # a connection failure:
298: $ConnectionRetriesLeft--;
1.42 foxr 299: if($ConnectionRetriesLeft <= 0) {
1.52 foxr 300: Log("CRITICAL", "Host marked DEAD: ".GetServerHost());
1.56 foxr 301: $LondConnecting = 0;
1.42 foxr 302: }
303:
1.15 foxr 304: }
1.64 ! foxr 305: #
! 306: # This function should be called by the child in all cases where it must
! 307: # exit. If the child process is running with the DieWhenIdle turned on
! 308: # it must create a lock file for the AF_UNIX socket in order to prevent
! 309: # connection requests from lonnet in the time between process exit
! 310: # and the parent picking up the listen again.
! 311: # Parameters:
! 312: # exit_code - Exit status value, however see the next parameter.
! 313: # message - If this optional parameter is supplied, the exit
! 314: # is via a die with this message.
! 315: #
! 316: sub child_exit {
! 317: my ($exit_code, $message) = @_;
! 318:
! 319: # Regardless of how we exit, we may need to do the lock thing:
! 320:
! 321: if($DieWhenIdle) {
! 322: #
! 323: # Create a lock file since there will be a time window
! 324: # between our exit and the parent's picking up the listen
! 325: # during which no listens will be done on the
! 326: # lonnet client socket.
! 327: #
! 328: my $lock_file = GetLoncSocketPath().".lock";
! 329: open(LOCK,">$lock_file");
! 330: print LOCK "Contents not important";
! 331: close(LOCK);
! 332:
! 333: exit(0);
! 334: }
! 335: # Now figure out how we exit:
! 336:
! 337: if($message) {
! 338: die $message;
! 339: } else {
! 340: exit($exit_code);
! 341: }
! 342: }
1.35 foxr 343: #----------------------------- Timer management ------------------------
1.15 foxr 344:
345: =pod
346:
1.1 foxr 347: =head2 Tick
1.3 albertel 348:
349: Invoked each timer tick.
350:
1.1 foxr 351: =cut
352:
1.5 foxr 353:
1.1 foxr 354: sub Tick {
1.52 foxr 355: my ($Event) = @_;
356: my $clock_watcher = $Event->w;
357:
1.1 foxr 358: my $client;
1.57 foxr 359: UpdateStatus();
360:
1.4 foxr 361: # Is it time to prune connection count:
362:
363:
364: if($IdleConnections->Count() &&
365: ($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
1.52 foxr 366: $IdleSeconds++;
1.4 foxr 367: if($IdleSeconds > $IdleTimeout) { # Prune a connection...
1.23 foxr 368: my $Socket = $IdleConnections->pop();
1.6 foxr 369: KillSocket($Socket);
1.54 foxr 370: $IdleSeconds = 0; # Otherwise all connections get trimmed to fast.
1.57 foxr 371: UpdateStatus();
372: if(($ConnectionCount == 0) && $DieWhenIdle) {
1.64 ! foxr 373: &child_exit(0);
! 374:
1.57 foxr 375: }
1.4 foxr 376: }
377: } else {
378: $IdleSeconds = 0; # Reset idle count if not idle.
379: }
1.15 foxr 380: #
381: # For each inflight transaction, tick down its timeout counter.
382: #
1.35 foxr 383:
1.34 albertel 384: foreach my $item (keys %ActiveConnections) {
385: my $State = $ActiveConnections{$item}->data->GetState();
1.35 foxr 386: if ($State ne 'Idle') {
1.34 albertel 387: Debug(5,"Ticking Socket $State $item");
388: $ActiveConnections{$item}->data->Tick();
389: }
1.15 foxr 390: }
1.5 foxr 391: # Do we have work in the queue, but no connections to service them?
392: # If so, try to make some new connections to get things going again.
393: #
1.57 foxr 394: # Note this code is dead now...
395: #
1.5 foxr 396: my $Requests = $WorkQueue->Count();
1.56 foxr 397: if (($ConnectionCount == 0) && ($Requests > 0) && (!$LondConnecting)) {
1.10 foxr 398: if ($ConnectionRetriesLeft > 0) {
1.56 foxr 399: Debug(5,"Work but no connections, Make a new one");
400: my $success;
401: $success = &MakeLondConnection;
402: if($success == 0) { # All connections failed:
1.29 foxr 403: Debug(5,"Work in queue failed to make any connectiouns\n");
1.22 foxr 404: EmptyQueue(); # Fail pending transactions with con_lost.
1.42 foxr 405: CloseAllLondConnections(); # Should all be closed but....
1.10 foxr 406: }
407: } else {
1.56 foxr 408: $LondConnecting = 0;
1.22 foxr 409: ShowStatus(GetServerHost()." >>> DEAD!!! <<<");
1.29 foxr 410: Debug(5,"Work in queue, but gave up on connections..flushing\n");
1.10 foxr 411: EmptyQueue(); # Connections can't be established.
1.42 foxr 412: CloseAllLondConnections(); # Should all already be closed but...
1.5 foxr 413: }
414:
415: }
1.49 foxr 416: if ($ConnectionCount == 0) {
417: $KeyMode = "";
1.52 foxr 418: $clock_watcher->cancel();
1.49 foxr 419: }
1.1 foxr 420: }
421:
422: =pod
1.3 albertel 423:
1.1 foxr 424: =head2 SetupTimer
425:
1.3 albertel 426: Sets up a 1 per sec recurring timer event. The event handler is used to:
1.1 foxr 427:
1.3 albertel 428: =item
429:
430: Trigger timeouts on communications along active sockets.
431:
432: =item
433:
434: Trigger disconnections of idle sockets.
1.1 foxr 435:
436: =cut
437:
438: sub SetupTimer {
1.52 foxr 439: Debug(6, "SetupTimer");
440: Event->timer(interval => 1, cb => \&Tick );
1.1 foxr 441: }
1.3 albertel 442:
1.1 foxr 443: =pod
1.3 albertel 444:
1.1 foxr 445: =head2 ServerToIdle
1.3 albertel 446:
447: This function is called when a connection to the server is
448: ready for more work.
449:
450: If there is work in the Work queue the top element is dequeued
1.1 foxr 451: and the connection will start to work on it. If the work queue is
452: empty, the connection is pushed on the idle connection stack where
453: it will either get another work unit, or alternatively, if it sits there
454: long enough, it will be shut down and released.
455:
1.3 albertel 456: =cut
1.1 foxr 457:
458: sub ServerToIdle {
459: my $Socket = shift; # Get the socket.
1.49 foxr 460: $KeyMode = $Socket->{AuthenticationMode};
1.7 foxr 461: delete($ActiveTransactions{$Socket}); # Server has no transaction
1.1 foxr 462:
1.29 foxr 463: &Debug(5, "Server to idle");
1.1 foxr 464:
465: # If there's work to do, start the transaction:
466:
1.23 foxr 467: my $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
1.29 foxr 468: if ($reqdata ne undef) {
469: Debug(5, "Queue gave request data: ".$reqdata->getRequest());
1.7 foxr 470: &StartRequest($Socket, $reqdata);
1.8 foxr 471:
1.1 foxr 472: } else {
473:
474: # There's no work waiting, so push the server to idle list.
1.29 foxr 475: &Debug(5, "No new work requests, server connection going idle");
1.1 foxr 476: $IdleConnections->push($Socket);
477: }
478: }
1.3 albertel 479:
1.1 foxr 480: =pod
1.3 albertel 481:
1.1 foxr 482: =head2 ClientWritable
1.3 albertel 483:
484: Event callback for when a client socket is writable.
485:
486: This callback is established when a transaction reponse is
487: avaiable from lond. The response is forwarded to the unix socket
488: as it becomes writable in this sub.
489:
1.1 foxr 490: Parameters:
491:
1.3 albertel 492: =item Event
493:
494: The event that has been triggered. Event->w->data is
495: the data and Event->w->fd is the socket to write.
1.1 foxr 496:
497: =cut
1.3 albertel 498:
1.1 foxr 499: sub ClientWritable {
500: my $Event = shift;
501: my $Watcher = $Event->w;
502: my $Data = $Watcher->data;
503: my $Socket = $Watcher->fd;
504:
505: # Try to send the data:
506:
507: &Debug(6, "ClientWritable writing".$Data);
508: &Debug(9, "Socket is: ".$Socket);
509:
1.6 foxr 510: if($Socket->connected) {
511: my $result = $Socket->send($Data, 0);
512:
513: # $result undefined: the write failed.
514: # otherwise $result is the number of bytes written.
515: # Remove that preceding string from the data.
516: # If the resulting data is empty, destroy the watcher
517: # and set up a read event handler to accept the next
518: # request.
519:
520: &Debug(9,"Send result is ".$result." Defined: ".defined($result));
1.29 foxr 521: if($result ne undef) {
1.6 foxr 522: &Debug(9, "send result was defined");
523: if($result == length($Data)) { # Entire string sent.
524: &Debug(9, "ClientWritable data all written");
525: $Watcher->cancel();
526: #
527: # Set up to read next request from socket:
528:
529: my $descr = sprintf("Connection to lonc client %d",
530: $ActiveClients{$Socket});
531: Event->io(cb => \&ClientRequest,
532: poll => 'r',
533: desc => $descr,
534: data => "",
535: fd => $Socket);
536:
537: } else { # Partial string sent.
538: $Watcher->data(substr($Data, $result));
1.15 foxr 539: if($result == 0) { # client hung up on us!!
1.52 foxr 540: # Log("INFO", "lonc pipe client hung up on us!");
1.15 foxr 541: $Watcher->cancel;
542: $Socket->shutdown(2);
543: $Socket->close();
544: }
1.6 foxr 545: }
546:
547: } else { # Error of some sort...
548:
549: # Some errnos are possible:
550: my $errno = $!;
551: if($errno == POSIX::EWOULDBLOCK ||
552: $errno == POSIX::EAGAIN ||
553: $errno == POSIX::EINTR) {
554: # No action taken?
555: } else { # Unanticipated errno.
556: &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
557: $Watcher->cancel; # Stop the watcher.
558: $Socket->shutdown(2); # Kill connection
559: $Socket->close(); # Close the socket.
560: }
1.1 foxr 561:
562: }
1.6 foxr 563: } else {
564: $Watcher->cancel(); # A delayed request...just cancel.
1.1 foxr 565: }
566: }
567:
568: =pod
1.3 albertel 569:
1.1 foxr 570: =head2 CompleteTransaction
1.3 albertel 571:
572: Called when the reply data has been received for a lond
1.1 foxr 573: transaction. The reply data must now be sent to the
574: ultimate client on the other end of the Unix socket. This is
575: done by setting up a writable event for the socket with the
576: data the reply data.
1.3 albertel 577:
1.1 foxr 578: Parameters:
1.3 albertel 579:
580: =item Socket
581:
582: Socket on which the lond transaction occured. This is a
583: LondConnection. The data received is in the TransactionReply member.
584:
1.7 foxr 585: =item Transaction
1.3 albertel 586:
1.7 foxr 587: The transaction that is being completed.
1.1 foxr 588:
589: =cut
1.3 albertel 590:
1.1 foxr 591: sub CompleteTransaction {
1.29 foxr 592: &Debug(5,"Complete transaction");
1.47 foxr 593:
594: my ($Socket, $Transaction) = @_;
1.1 foxr 595:
1.7 foxr 596: if (!$Transaction->isDeferred()) { # Normal transaction
597: my $data = $Socket->GetReply(); # Data to send.
1.39 foxr 598: if($LogTransactions) {
599: Log("SUCCESS", "Reply from lond: '$data'");
600: }
1.7 foxr 601: StartClientReply($Transaction, $data);
602: } else { # Delete deferred transaction file.
1.9 foxr 603: Log("SUCCESS", "A delayed transaction was completed");
1.23 foxr 604: LogPerm("S:$Transaction->getClient() :".$Transaction->getRequest());
1.7 foxr 605: unlink $Transaction->getFile();
606: }
1.6 foxr 607: }
1.42 foxr 608:
1.6 foxr 609: =pod
1.42 foxr 610:
1.6 foxr 611: =head1 StartClientReply
612:
613: Initiates a reply to a client where the reply data is a parameter.
614:
1.7 foxr 615: =head2 parameters:
616:
617: =item Transaction
618:
619: The transaction for which we are responding to the client.
620:
621: =item data
622:
623: The data to send to apached client.
624:
1.6 foxr 625: =cut
1.42 foxr 626:
1.6 foxr 627: sub StartClientReply {
1.1 foxr 628:
1.47 foxr 629: my ($Transaction, $data) = @_;
1.12 foxr 630:
1.7 foxr 631: my $Client = $Transaction->getClient();
632:
1.1 foxr 633: &Debug(8," Reply was: ".$data);
634: my $Serial = $ActiveClients{$Client};
635: my $desc = sprintf("Connection to lonc client %d",
636: $Serial);
637: Event->io(fd => $Client,
638: poll => "w",
639: desc => $desc,
640: cb => \&ClientWritable,
641: data => $data);
642: }
1.42 foxr 643:
1.4 foxr 644: =pod
1.42 foxr 645:
1.4 foxr 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:
1.42 foxr 655: Deleting the transaction means killing it from the %ActiveTransactions hash.
1.4 foxr 656:
657: Parameters:
658:
659: =item client
660:
1.7 foxr 661: The LondTransaction we are failing.
662:
1.42 foxr 663:
1.4 foxr 664: =cut
665:
666: sub FailTransaction {
1.7 foxr 667: my $transaction = shift;
1.52 foxr 668:
669: # If the socket is dead, that's already logged.
670:
671: if ($ConnectionRetriesLeft > 0) {
672: Log("WARNING", "Failing transaction "
673: .$transaction->getRequest());
674: }
1.30 foxr 675: Debug(1, "Failing transaction: ".$transaction->getRequest());
1.10 foxr 676: if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
1.11 foxr 677: my $client = $transaction->getClient();
1.30 foxr 678: Debug(1," Replying con_lost to ".$transaction->getRequest());
1.11 foxr 679: StartClientReply($transaction, "con_lost\n");
1.7 foxr 680: }
1.4 foxr 681:
682: }
683:
684: =pod
1.6 foxr 685: =head1 EmptyQueue
1.7 foxr 686:
1.6 foxr 687: Fails all items in the work queue with con_lost.
1.7 foxr 688: Note that each item in the work queue is a transaction.
689:
1.6 foxr 690: =cut
691: sub EmptyQueue {
1.22 foxr 692: $ConnectionRetriesLeft--; # Counts as connection failure too.
1.6 foxr 693: while($WorkQueue->Count()) {
1.10 foxr 694: my $request = $WorkQueue->dequeue(); # This is a transaction
1.7 foxr 695: FailTransaction($request);
1.6 foxr 696: }
697: }
698:
699: =pod
1.4 foxr 700:
1.9 foxr 701: =head2 CloseAllLondConnections
702:
703: Close all connections open on lond prior to exit e.g.
704:
705: =cut
706: sub CloseAllLondConnections {
1.23 foxr 707: foreach my $Socket (keys %ActiveConnections) {
1.42 foxr 708: if(exists($ActiveTransactions{$Socket})) {
709: FailTransaction($ActiveTransactions{$Socket});
710: }
711: KillSocket($Socket);
1.9 foxr 712: }
713: }
714: =cut
715:
716: =pod
717:
1.4 foxr 718: =head2 KillSocket
719:
720: Destroys a socket. This function can be called either when a socket
721: has died of 'natural' causes or because a socket needs to be pruned due to
722: idleness. If the socket has died naturally, if there are no longer any
723: live connections a new connection is created (in case there are transactions
724: in the queue). If the socket has been pruned, it is never re-created.
725:
726: Parameters:
1.1 foxr 727:
1.4 foxr 728: =item Socket
729:
730: The socket to kill off.
731:
732: =item Restart
733:
734: nonzero if we are allowed to create a new connection.
735:
736:
737: =cut
738: sub KillSocket {
739: my $Socket = shift;
740:
1.17 foxr 741: Log("WARNING", "Shutting down a socket");
1.9 foxr 742: $Socket->Shutdown();
743:
1.7 foxr 744: # If the socket came from the active connection set,
745: # delete its transaction... note that FailTransaction should
746: # already have been called!!!
747: # otherwise it came from the idle set.
748: #
1.4 foxr 749:
750: if(exists($ActiveTransactions{$Socket})) {
751: delete ($ActiveTransactions{$Socket});
752: }
753: if(exists($ActiveConnections{$Socket})) {
754: delete($ActiveConnections{$Socket});
1.37 albertel 755: $ConnectionCount--;
756: if ($ConnectionCount < 0) { $ConnectionCount = 0; }
1.4 foxr 757: }
1.6 foxr 758: # If the connection count has gone to zero and there is work in the
759: # work queue, the work all gets failed with con_lost.
760: #
761: if($ConnectionCount == 0) {
1.22 foxr 762: EmptyQueue();
1.42 foxr 763: CloseAllLondConnections; # Should all already be closed but...
1.4 foxr 764: }
765: }
1.1 foxr 766:
767: =pod
1.3 albertel 768:
1.1 foxr 769: =head2 LondReadable
1.3 albertel 770:
1.1 foxr 771: This function is called whenever a lond connection
772: is readable. The action is state dependent:
773:
1.3 albertel 774: =head3 State=Initialized
775:
776: We''re waiting for the challenge, this is a no-op until the
1.1 foxr 777: state changes.
1.3 albertel 778:
1.1 foxr 779: =head3 State=Challenged
1.3 albertel 780:
781: The challenge has arrived we need to transition to Writable.
1.1 foxr 782: The connection must echo the challenge back.
1.3 albertel 783:
1.1 foxr 784: =head3 State=ChallengeReplied
1.3 albertel 785:
786: The challenge has been replied to. The we are receiveing the
1.1 foxr 787: 'ok' from the partner.
1.3 albertel 788:
1.40 foxr 789: =head3 State=ReadingVersionString
790:
791: We have requested the lond version and are reading the
792: version back. Upon completion, we'll store the version away
793: for future use(?).
794:
795: =head3 State=HostSet
796:
797: We have selected the domain name of our peer (multhomed hosts)
798: and are getting the reply (presumably ok) back.
799:
1.1 foxr 800: =head3 State=RequestingKey
1.3 albertel 801:
802: The ok has been received and we need to send the request for
1.1 foxr 803: an encryption key. Transition to writable for that.
1.3 albertel 804:
1.1 foxr 805: =head3 State=ReceivingKey
1.3 albertel 806:
807: The the key has been requested, now we are reading the new key.
808:
1.1 foxr 809: =head3 State=Idle
1.3 albertel 810:
811: The encryption key has been negotiated or we have finished
1.1 foxr 812: reading data from the a transaction. If the callback data has
813: a client as well as the socket iformation, then we are
814: doing a transaction and the data received is relayed to the client
815: before the socket is put on the idle list.
1.3 albertel 816:
1.1 foxr 817: =head3 State=SendingRequest
1.3 albertel 818:
819: I do not think this state can be received here, but if it is,
1.1 foxr 820: the appropriate thing to do is to transition to writable, and send
821: the request.
1.3 albertel 822:
1.1 foxr 823: =head3 State=ReceivingReply
1.3 albertel 824:
825: We finished sending the request to the server and now transition
1.1 foxr 826: to readable to receive the reply.
827:
828: The parameter to this function are:
1.3 albertel 829:
1.1 foxr 830: The event. Implicit in this is the watcher and its data. The data
831: contains at least the lond connection object and, if a
832: transaction is in progress, the socket attached to the local client.
833:
1.3 albertel 834: =cut
1.1 foxr 835:
836: sub LondReadable {
1.8 foxr 837:
1.41 albertel 838: my $Event = shift;
839: my $Watcher = $Event->w;
840: my $Socket = $Watcher->data;
841: my $client = undef;
1.40 foxr 842:
1.41 albertel 843: &Debug(6,"LondReadable called state = ".$Socket->GetState());
1.40 foxr 844:
845:
1.41 albertel 846: my $State = $Socket->GetState(); # All action depends on the state.
1.40 foxr 847:
1.41 albertel 848: SocketDump(6, $Socket);
849: my $status = $Socket->Readable();
1.40 foxr 850:
1.41 albertel 851: &Debug(2, "Socket->Readable returned: $status");
1.40 foxr 852:
1.41 albertel 853: if($status != 0) {
854: # bad return from socket read. Currently this means that
855: # The socket has become disconnected. We fail the transaction.
1.40 foxr 856:
1.41 albertel 857: Log("WARNING",
858: "Lond connection lost.");
859: if(exists($ActiveTransactions{$Socket})) {
860: FailTransaction($ActiveTransactions{$Socket});
1.56 foxr 861: } else {
862: # Socket is connecting and failed... need to mark
863: # no longer connecting.
864:
865: $LondConnecting = 0;
1.41 albertel 866: }
867: $Watcher->cancel();
868: KillSocket($Socket);
869: $ConnectionRetriesLeft--; # Counts as connection failure
870: return;
871: }
872: SocketDump(6,$Socket);
1.17 foxr 873:
1.41 albertel 874: $State = $Socket->GetState(); # Update in case of transition.
875: &Debug(6, "After read, state is ".$State);
1.1 foxr 876:
1.41 albertel 877: if($State eq "Initialized") {
1.1 foxr 878:
879:
1.41 albertel 880: } elsif ($State eq "ChallengeReceived") {
1.1 foxr 881: # The challenge must be echoed back; The state machine
882: # in the connection takes care of setting that up. Just
883: # need to transition to writable:
1.41 albertel 884:
885: $Watcher->cb(\&LondWritable);
886: $Watcher->poll("w");
1.1 foxr 887:
1.41 albertel 888: } elsif ($State eq "ChallengeReplied") {
1.1 foxr 889:
1.41 albertel 890: } elsif ($State eq "RequestingVersion") {
891: # Need to ask for the version... that is writiability:
1.1 foxr 892:
1.41 albertel 893: $Watcher->cb(\&LondWritable);
894: $Watcher->poll("w");
895:
896: } elsif ($State eq "ReadingVersionString") {
897: # Read the rest of the version string...
898: } elsif ($State eq "SetHost") {
899: # Need to request the actual domain get set...
900:
901: $Watcher->cb(\&LondWritable);
902: $Watcher->poll("w");
903: } elsif ($State eq "HostSet") {
904: # Reading the 'ok' from the peer.
905:
906: } elsif ($State eq "RequestingKey") {
1.1 foxr 907: # The ok was received. Now we need to request the key
908: # That requires us to be writable:
909:
1.41 albertel 910: $Watcher->cb(\&LondWritable);
911: $Watcher->poll("w");
1.1 foxr 912:
1.41 albertel 913: } elsif ($State eq "ReceivingKey") {
1.1 foxr 914:
1.41 albertel 915: } elsif ($State eq "Idle") {
1.40 foxr 916:
1.41 albertel 917: # This is as good a spot as any to get the peer version
918: # string:
1.40 foxr 919:
1.41 albertel 920: if($LondVersion eq "unknown") {
921: $LondVersion = $Socket->PeerVersion();
922: Log("INFO", "Connected to lond version: $LondVersion");
923: }
1.1 foxr 924: # If necessary, complete a transaction and then go into the
925: # idle queue.
1.22 foxr 926: # Note that a trasition to idle indicates a live lond
927: # on the other end so reset the connection retries.
928: #
1.41 albertel 929: $ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
930: $Watcher->cancel();
931: if(exists($ActiveTransactions{$Socket})) {
932: Debug(5,"Completing transaction!!");
933: CompleteTransaction($Socket,
934: $ActiveTransactions{$Socket});
935: } else {
936: Log("SUCCESS", "Connection ".$ConnectionCount." to "
937: .$RemoteHost." now ready for action");
938: }
939: ServerToIdle($Socket); # Next work unit or idle.
1.54 foxr 940:
941: #
942: $LondConnecting = 0; # Best spot I can think of for this.
943: #
1.6 foxr 944:
1.41 albertel 945: } elsif ($State eq "SendingRequest") {
1.1 foxr 946: # We need to be writable for this and probably don't belong
947: # here inthe first place.
948:
1.41 albertel 949: Deubg(6, "SendingRequest state encountered in readable");
950: $Watcher->poll("w");
951: $Watcher->cb(\&LondWritable);
1.1 foxr 952:
1.41 albertel 953: } elsif ($State eq "ReceivingReply") {
1.1 foxr 954:
955:
1.41 albertel 956: } else {
957: # Invalid state.
958: Debug(4, "Invalid state in LondReadable");
959: }
1.1 foxr 960: }
1.3 albertel 961:
1.1 foxr 962: =pod
1.3 albertel 963:
1.1 foxr 964: =head2 LondWritable
1.3 albertel 965:
1.1 foxr 966: This function is called whenever a lond connection
967: becomes writable while there is a writeable monitoring
968: event. The action taken is very state dependent:
1.3 albertel 969:
1.1 foxr 970: =head3 State = Connected
1.3 albertel 971:
972: The connection is in the process of sending the 'init' hailing to the
973: lond on the remote end. The connection object''s Writable member is
974: called. On error, ConnectionError is called to destroy the connection
975: and remove it from the ActiveConnections hash
976:
1.1 foxr 977: =head3 Initialized
1.3 albertel 978:
979: 'init' has been sent, writability monitoring is removed and
980: readability monitoring is started with LondReadable as the callback.
981:
1.1 foxr 982: =head3 ChallengeReceived
1.3 albertel 983:
984: The connection has received the who are you challenge from the remote
985: system, and is in the process of sending the challenge
986: response. Writable is called.
987:
1.1 foxr 988: =head3 ChallengeReplied
1.3 albertel 989:
990: The connection has replied to the initial challenge The we switch to
991: monitoring readability looking for the server to reply with 'ok'.
992:
1.1 foxr 993: =head3 RequestingKey
1.3 albertel 994:
995: The connection is in the process of requesting its encryption key.
996: Writable is called.
997:
1.1 foxr 998: =head3 ReceivingKey
1.3 albertel 999:
1000: The connection has sent the request for a key. Switch to readability
1001: monitoring to accept the key
1002:
1.1 foxr 1003: =head3 SendingRequest
1.3 albertel 1004:
1005: The connection is in the process of sending a request to the server.
1006: This request is part of a client transaction. All the states until
1007: now represent the client setup protocol. Writable is called.
1008:
1.1 foxr 1009: =head3 ReceivingReply
1010:
1.3 albertel 1011: The connection has sent a request. Now it must receive a reply.
1012: Readability monitoring is requested.
1013:
1014: This function is an event handler and therefore receives as
1.1 foxr 1015: a parameter the event that has fired. The data for the watcher
1016: of this event is a reference to a list of one or two elements,
1017: depending on state. The first (and possibly only) element is the
1018: socket. The second (present only if a request is in progress)
1019: is the socket on which to return a reply to the caller.
1020:
1021: =cut
1.3 albertel 1022:
1.1 foxr 1023: sub LondWritable {
1024: my $Event = shift;
1025: my $Watcher = $Event->w;
1.8 foxr 1026: my $Socket = $Watcher->data;
1027: my $State = $Socket->GetState();
1.1 foxr 1028:
1.8 foxr 1029: Debug(6,"LondWritable State = ".$State."\n");
1.1 foxr 1030:
1.8 foxr 1031:
1.1 foxr 1032: # Figure out what to do depending on the state of the socket:
1033:
1034:
1035:
1036:
1037: SocketDump(6,$Socket);
1038:
1.42 foxr 1039: # If the socket is writable, we must always write.
1040: # Only by writing will we undergo state transitions.
1041: # Old logic wrote in state specific code below, however
1042: # That forces us at least through another invocation of
1043: # this function after writability is possible again.
1044: # This logic also factors out common code for handling
1045: # write failures... in all cases, write failures
1046: # Kill the socket.
1047: # This logic makes the branches of the >big< if below
1048: # so that the writing states are actually NO-OPs.
1049:
1050: if ($Socket->Writable() != 0) {
1.43 albertel 1051: # The write resulted in an error.
1052: # We'll treat this as if the socket got disconnected:
1053: Log("WARNING", "Connection to ".$RemoteHost.
1054: " has been disconnected");
1055: if(exists($ActiveTransactions{$Socket})) {
1056: FailTransaction($ActiveTransactions{$Socket});
1.56 foxr 1057: } else {
1058: # In the process of conneting, so need to turn that off.
1059:
1060: $LondConnecting = 0;
1.43 albertel 1061: }
1062: $Watcher->cancel();
1063: KillSocket($Socket);
1064: return;
1.42 foxr 1065: }
1066:
1067:
1068:
1.41 albertel 1069: if ($State eq "Connected") {
1.1 foxr 1070:
1.41 albertel 1071: # "init" is being sent...
1.42 foxr 1072:
1.41 albertel 1073: } elsif ($State eq "Initialized") {
1.4 foxr 1074:
1.41 albertel 1075: # Now that init was sent, we switch
1076: # to watching for readability:
1.1 foxr 1077:
1.41 albertel 1078: $Watcher->cb(\&LondReadable);
1079: $Watcher->poll("r");
1080:
1081: } elsif ($State eq "ChallengeReceived") {
1082: # We received the challenge, now we
1083: # are echoing it back. This is a no-op,
1084: # we're waiting for the state to change
1.1 foxr 1085:
1.41 albertel 1086: } elsif ($State eq "ChallengeReplied") {
1087: # The echo was sent back, so we switch
1088: # to watching readability.
1089:
1090: $Watcher->cb(\&LondReadable);
1091: $Watcher->poll("r");
1092: } elsif ($State eq "RequestingVersion") {
1093: # Sending the peer a version request...
1.42 foxr 1094:
1.41 albertel 1095: } elsif ($State eq "ReadingVersionString") {
1096: # Transition to read since we have sent the
1097: # version command and now just need to read the
1098: # version string from the peer:
1.40 foxr 1099:
1.41 albertel 1100: $Watcher->cb(\&LondReadable);
1101: $Watcher->poll("r");
1.40 foxr 1102:
1.41 albertel 1103: } elsif ($State eq "SetHost") {
1104: # Setting the remote domain...
1.42 foxr 1105:
1.41 albertel 1106: } elsif ($State eq "HostSet") {
1107: # Back to readable to get the ok.
1.40 foxr 1108:
1.41 albertel 1109: $Watcher->cb(\&LondReadable);
1110: $Watcher->poll("r");
1.40 foxr 1111:
1112:
1.41 albertel 1113: } elsif ($State eq "RequestingKey") {
1114: # At this time we're requesting the key.
1115: # again, this is essentially a no-op.
1116:
1117: } elsif ($State eq "ReceivingKey") {
1118: # Now we need to wait for the key
1119: # to come back from the peer:
1120:
1121: $Watcher->cb(\&LondReadable);
1122: $Watcher->poll("r");
1123:
1124: } elsif ($State eq "SendingRequest") {
1.40 foxr 1125:
1.41 albertel 1126: # At this time we are sending a request to the
1.1 foxr 1127: # peer... write the next chunk:
1128:
1.41 albertel 1129:
1130: } elsif ($State eq "ReceivingReply") {
1131: # The send has completed. Wait for the
1132: # data to come in for a reply.
1133: Debug(8,"Writable sent request/receiving reply");
1134: $Watcher->cb(\&LondReadable);
1135: $Watcher->poll("r");
1.1 foxr 1136:
1.41 albertel 1137: } else {
1138: # Control only passes here on an error:
1139: # the socket state does not match any
1140: # of the known states... so an error
1141: # must be logged.
1.1 foxr 1142:
1.41 albertel 1143: &Debug(4, "Invalid socket state ".$State."\n");
1144: }
1.1 foxr 1145:
1146: }
1.6 foxr 1147: =pod
1148:
1149: =cut
1150: sub QueueDelayed {
1.8 foxr 1151: Debug(3,"QueueDelayed called");
1152:
1.6 foxr 1153: my $path = "$perlvar{'lonSockDir'}/delayed";
1.8 foxr 1154:
1155: Debug(4, "Delayed path: ".$path);
1.6 foxr 1156: opendir(DIRHANDLE, $path);
1.8 foxr 1157:
1.23 foxr 1158: my @alldelayed = grep /\.$RemoteHost$/, readdir DIRHANDLE;
1.6 foxr 1159: closedir(DIRHANDLE);
1160: my $dfname;
1.8 foxr 1161: my $reqfile;
1162: foreach $dfname (sort @alldelayed) {
1163: $reqfile = "$path/$dfname";
1164: Debug(4, "queueing ".$reqfile);
1.6 foxr 1165: my $Handle = IO::File->new($reqfile);
1166: my $cmd = <$Handle>;
1.8 foxr 1167: chomp $cmd; # There may or may not be a newline...
1.12 foxr 1168: $cmd = $cmd."\n"; # now for sure there's exactly one newline.
1.7 foxr 1169: my $Transaction = LondTransaction->new($cmd);
1170: $Transaction->SetDeferred($reqfile);
1171: QueueTransaction($Transaction);
1.6 foxr 1172: }
1173:
1174: }
1.1 foxr 1175:
1176: =pod
1.3 albertel 1177:
1.1 foxr 1178: =head2 MakeLondConnection
1.3 albertel 1179:
1180: Create a new lond connection object, and start it towards its initial
1181: idleness. Once idle, it becomes elligible to receive transactions
1182: from the work queue. If the work queue is not empty when the
1183: connection is completed and becomes idle, it will dequeue an entry and
1184: start off on it.
1185:
1.1 foxr 1186: =cut
1.3 albertel 1187:
1.1 foxr 1188: sub MakeLondConnection {
1189: Debug(4,"MakeLondConnection to ".GetServerHost()." on port "
1190: .GetServerPort());
1191:
1192: my $Connection = LondConnection->new(&GetServerHost(),
1193: &GetServerPort());
1194:
1.30 foxr 1195: if($Connection eq undef) { # Needs to be more robust later.
1.9 foxr 1196: Log("CRITICAL","Failed to make a connection with lond.");
1.10 foxr 1197: $ConnectionRetriesLeft--;
1198: return 0; # Failure.
1.5 foxr 1199: } else {
1.22 foxr 1200:
1.5 foxr 1201: # The connection needs to have writability
1202: # monitored in order to send the init sequence
1203: # that starts the whole authentication/key
1204: # exchange underway.
1205: #
1206: my $Socket = $Connection->GetSocket();
1.30 foxr 1207: if($Socket eq undef) {
1.64 ! foxr 1208: &child_exit(-1, "did not get a socket from the connection");
1.5 foxr 1209: } else {
1210: &Debug(9,"MakeLondConnection got socket: ".$Socket);
1211: }
1.1 foxr 1212:
1.21 foxr 1213: $Connection->SetTimeoutCallback(\&SocketTimeout);
1214:
1.23 foxr 1215: my $event = Event->io(fd => $Socket,
1.5 foxr 1216: poll => 'w',
1217: cb => \&LondWritable,
1.8 foxr 1218: data => $Connection,
1.5 foxr 1219: desc => 'Connection to lond server');
1220: $ActiveConnections{$Connection} = $event;
1.52 foxr 1221: if ($ConnectionCount == 0) {
1222: &SetupTimer; # Need to handle timeouts with connections...
1223: }
1.5 foxr 1224: $ConnectionCount++;
1.8 foxr 1225: Debug(4, "Connection count = ".$ConnectionCount);
1.6 foxr 1226: if($ConnectionCount == 1) { # First Connection:
1227: QueueDelayed;
1228: }
1.9 foxr 1229: Log("SUCESS", "Created connection ".$ConnectionCount
1230: ." to host ".GetServerHost());
1.54 foxr 1231: $LondConnecting = 1; # Connection in progress.
1.10 foxr 1232: return 1; # Return success.
1.1 foxr 1233: }
1234:
1235: }
1.3 albertel 1236:
1.1 foxr 1237: =pod
1.3 albertel 1238:
1.1 foxr 1239: =head2 StartRequest
1.3 albertel 1240:
1241: Starts a lond request going on a specified lond connection.
1242: parameters are:
1243:
1244: =item $Lond
1245:
1246: Connection to the lond that will send the transaction and receive the
1247: reply.
1248:
1249: =item $Client
1250:
1251: Connection to the client that is making this request We got the
1252: request from this socket, and when the request has been relayed to
1253: lond and we get a reply back from lond it will get sent to this
1254: socket.
1255:
1256: =item $Request
1257:
1258: The text of the request to send.
1259:
1.1 foxr 1260: =cut
1261:
1262: sub StartRequest {
1.47 foxr 1263:
1264: my ($Lond, $Request) = @_;
1.1 foxr 1265:
1.7 foxr 1266: Debug(6, "StartRequest: ".$Request->getRequest());
1.1 foxr 1267:
1268: my $Socket = $Lond->GetSocket();
1269:
1.7 foxr 1270: $Request->Activate($Lond);
1271: $ActiveTransactions{$Lond} = $Request;
1.1 foxr 1272:
1.7 foxr 1273: $Lond->InitiateTransaction($Request->getRequest());
1.23 foxr 1274: my $event = Event->io(fd => $Socket,
1.1 foxr 1275: poll => "w",
1276: cb => \&LondWritable,
1277: data => $Lond,
1278: desc => "lond transaction connection");
1279: $ActiveConnections{$Lond} = $event;
1280: Debug(8," Start Request made watcher data with ".$event->data."\n");
1281: }
1282:
1283: =pod
1.3 albertel 1284:
1.1 foxr 1285: =head2 QueueTransaction
1.3 albertel 1286:
1287: If there is an idle lond connection, it is put to work doing this
1288: transaction. Otherwise, the transaction is placed in the work queue.
1289: If placed in the work queue and the maximum number of connections has
1290: not yet been created, a new connection will be started. Our goal is
1291: to eventually have a sufficient number of connections that the work
1292: queue will typically be empty. parameters are:
1293:
1294: =item Socket
1295:
1296: open on the lonc client.
1297:
1298: =item Request
1299:
1300: data to send to the lond.
1.1 foxr 1301:
1302: =cut
1.3 albertel 1303:
1.1 foxr 1304: sub QueueTransaction {
1305:
1.7 foxr 1306: my $requestData = shift; # This is a LondTransaction.
1307: my $cmd = $requestData->getRequest();
1308:
1309: Debug(6,"QueueTransaction: ".$cmd);
1.1 foxr 1310:
1311: my $LondSocket = $IdleConnections->pop();
1312: if(!defined $LondSocket) { # Need to queue request.
1.29 foxr 1313: Debug(5,"Must queue...");
1.1 foxr 1314: $WorkQueue->enqueue($requestData);
1.56 foxr 1315: Debug(5, "Queue Transaction startnew $ConnectionCount $LondConnecting");
1316: if(($ConnectionCount < $MaxConnectionCount) && (! $LondConnecting)) {
1317:
1.22 foxr 1318: if($ConnectionRetriesLeft > 0) {
1.29 foxr 1319: Debug(5,"Starting additional lond connection");
1.56 foxr 1320: if(&MakeLondConnection() == 0) {
1.22 foxr 1321: EmptyQueue(); # Fail transactions, can't make connection.
1.42 foxr 1322: CloseAllLondConnections; # Should all be closed but...
1.22 foxr 1323: }
1324: } else {
1325: ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
1.56 foxr 1326: $LondConnecting = 0;
1.22 foxr 1327: EmptyQueue(); # It's worse than that ... he's dead Jim.
1.42 foxr 1328: CloseAllLondConnections; # Should all be closed but..
1.17 foxr 1329: }
1.1 foxr 1330: }
1331: } else { # Can start the request:
1332: Debug(8,"Can start...");
1.7 foxr 1333: StartRequest($LondSocket, $requestData);
1.1 foxr 1334: }
1335: }
1336:
1337: #-------------------------- Lonc UNIX socket handling ---------------------
1.3 albertel 1338:
1.1 foxr 1339: =pod
1.3 albertel 1340:
1.1 foxr 1341: =head2 ClientRequest
1.3 albertel 1342: Callback that is called when data can be read from the UNIX domain
1343: socket connecting us with an apache server process.
1.1 foxr 1344:
1345: =cut
1346:
1347: sub ClientRequest {
1348: Debug(6, "ClientRequest");
1349: my $event = shift;
1350: my $watcher = $event->w;
1351: my $socket = $watcher->fd;
1352: my $data = $watcher->data;
1353: my $thisread;
1354:
1355: Debug(9, " Watcher named: ".$watcher->desc);
1356:
1357: my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
1358: Debug(8, "rcv: data length = ".length($thisread)
1359: ." read =".$thisread);
1.29 foxr 1360: unless (defined $rv && length($thisread)) {
1.1 foxr 1361: # Likely eof on socket.
1362: Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
1363: close($socket);
1364: $watcher->cancel();
1365: delete($ActiveClients{$socket});
1.10 foxr 1366: return;
1.1 foxr 1367: }
1368: Debug(8,"Data: ".$data." this read: ".$thisread);
1369: $data = $data.$thisread; # Append new data.
1370: $watcher->data($data);
1.44 albertel 1371: if($data =~ /\n$/) { # Request entirely read.
1.10 foxr 1372: if($data eq "close_connection_exit\n") {
1.9 foxr 1373: Log("CRITICAL",
1374: "Request Close Connection ... exiting");
1375: CloseAllLondConnections();
1376: exit;
1377: }
1.1 foxr 1378: Debug(8, "Complete transaction received: ".$data);
1.39 foxr 1379: if($LogTransactions) {
1380: Log("SUCCESS", "Transaction: '$data'"); # Transaction has \n.
1381: }
1.8 foxr 1382: my $Transaction = LondTransaction->new($data);
1.7 foxr 1383: $Transaction->SetClient($socket);
1384: QueueTransaction($Transaction);
1.1 foxr 1385: $watcher->cancel(); # Done looking for input data.
1386: }
1387:
1388: }
1389:
1.62 foxr 1390: #
1391: # Accept a connection request for a client (lonc child) and
1392: # start up an event watcher to keep an eye on input from that
1393: # Event. This can be called both from NewClient and from
1394: # ChildProcess if we are started in DieWhenIdle mode.
1395: # Parameters:
1396: # $socket - The listener socket.
1397: # Returns:
1398: # NONE
1399: # Side Effects:
1400: # An event is made to watch the accepted connection.
1401: # Active clients hash is updated to reflect the new connection.
1402: # The client connection count is incremented.
1403: #
1404: sub accept_client {
1405: my ($socket) = @_;
1406:
1407: Debug(8, "Entering accept for lonc UNIX socket\n");
1408: my $connection = $socket->accept(); # Accept the client connection.
1409: Debug(8,"Connection request accepted from "
1410: .GetPeername($connection, AF_UNIX));
1411:
1412:
1413: my $description = sprintf("Connection to lonc client %d",
1414: $ClientConnection);
1415: Debug(9, "Creating event named: ".$description);
1416: Event->io(cb => \&ClientRequest,
1417: poll => 'r',
1418: desc => $description,
1419: data => "",
1420: fd => $connection);
1421: $ActiveClients{$connection} = $ClientConnection;
1422: $ClientConnection++;
1423: }
1.1 foxr 1424:
1425: =pod
1.3 albertel 1426:
1.1 foxr 1427: =head2 NewClient
1.3 albertel 1428:
1429: Callback that is called when a connection is received on the unix
1430: socket for a new client of lonc. The callback is parameterized by the
1431: event.. which is a-priori assumed to be an io event, and therefore has
1432: an fd member that is the Listener socket. We Accept the connection
1433: and register a new event on the readability of that socket:
1434:
1.1 foxr 1435: =cut
1.3 albertel 1436:
1.1 foxr 1437: sub NewClient {
1438: Debug(6, "NewClient");
1439: my $event = shift; # Get the event parameters.
1440: my $watcher = $event->w;
1441: my $socket = $watcher->fd; # Get the event' socket.
1442:
1.62 foxr 1443: &accept_client($socket);
1.1 foxr 1444: }
1.3 albertel 1445:
1446: =pod
1447:
1448: =head2 GetLoncSocketPath
1449:
1450: Returns the name of the UNIX socket on which to listen for client
1451: connections.
1.1 foxr 1452:
1.58 foxr 1453: =head2 Parameters:
1454:
1455: host (optional) - Name of the host socket to return.. defaults to
1456: the return from GetServerHost().
1457:
1.1 foxr 1458: =cut
1.3 albertel 1459:
1.1 foxr 1460: sub GetLoncSocketPath {
1.58 foxr 1461:
1462: my $host = GetServerHost(); # Default host.
1463: if (@_) {
1464: ($host) = @_; # Override if supplied.
1465: }
1466: return $UnixSocketDir."/".$host;
1.1 foxr 1467: }
1468:
1.3 albertel 1469: =pod
1470:
1471: =head2 GetServerHost
1472:
1473: Returns the host whose lond we talk with.
1474:
1.1 foxr 1475: =cut
1.3 albertel 1476:
1.7 foxr 1477: sub GetServerHost {
1.1 foxr 1478: return $RemoteHost; # Setup by the fork.
1479: }
1.3 albertel 1480:
1481: =pod
1482:
1483: =head2 GetServerPort
1484:
1485: Returns the lond port number.
1486:
1.1 foxr 1487: =cut
1.3 albertel 1488:
1.7 foxr 1489: sub GetServerPort {
1.1 foxr 1490: return $perlvar{londPort};
1491: }
1.3 albertel 1492:
1493: =pod
1494:
1495: =head2 SetupLoncListener
1496:
1497: Setup a lonc listener event. The event is called when the socket
1498: becomes readable.. that corresponds to the receipt of a new
1499: connection. The event handler established will accept the connection
1500: (creating a communcations channel), that int turn will establish
1501: another event handler to subess requests.
1.1 foxr 1502:
1.58 foxr 1503: =head2 Parameters:
1504:
1505: host (optional) Name of the host to set up a unix socket to.
1506:
1.1 foxr 1507: =cut
1.3 albertel 1508:
1.1 foxr 1509: sub SetupLoncListener {
1510:
1.58 foxr 1511: my $host = GetServerHost(); # Default host.
1512: if (@_) {
1513: ($host) = @_ # Override host with parameter.
1514: }
1515:
1.1 foxr 1516: my $socket;
1.58 foxr 1517: my $SocketName = GetLoncSocketPath($host);
1.1 foxr 1518: unlink($SocketName);
1.7 foxr 1519: unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,
1.55 albertel 1520: Listen => 250,
1.1 foxr 1521: Type => SOCK_STREAM)) {
1.64 ! foxr 1522: if($I_am_child) {
! 1523: &child_exit(-1, "Failed to create a lonc listener socket");
! 1524: } else {
! 1525: die "Failed to create a lonc listner socket";
! 1526: }
1.1 foxr 1527: }
1.59 foxr 1528: return $socket;
1.1 foxr 1529: }
1530:
1.39 foxr 1531: #
1532: # Toggle transaction logging.
1533: # Implicit inputs:
1534: # LogTransactions
1535: # Implicit Outputs:
1536: # LogTransactions
1537: sub ToggleTransactionLogging {
1538: print STDERR "Toggle transaction logging...\n";
1539: if(!$LogTransactions) {
1540: $LogTransactions = 1;
1541: } else {
1542: $LogTransactions = 0;
1543: }
1544:
1545:
1546: Log("SUCCESS", "Toggled transaction logging: $LogTransactions \n");
1547: }
1548:
1.14 foxr 1549: =pod
1550:
1551: =head2 ChildStatus
1552:
1553: Child USR1 signal handler to report the most recent status
1554: into the status file.
1555:
1.22 foxr 1556: We also use this to reset the retries count in order to allow the
1557: client to retry connections with a previously dead server.
1.14 foxr 1558: =cut
1.46 albertel 1559:
1.14 foxr 1560: sub ChildStatus {
1561: my $event = shift;
1562: my $watcher = $event->w;
1563:
1564: Debug(2, "Reporting child status because : ".$watcher->data);
1565: my $docdir = $perlvar{'lonDocRoot'};
1566: my $fh = IO::File->new(">>$docdir/lon-status/loncstatus.txt");
1567: print $fh $$."\t".$RemoteHost."\t".$Status."\t".
1568: $RecentLogEntry."\n";
1.38 foxr 1569: #
1570: # Write out information about each of the connections:
1571: #
1.46 albertel 1572: if ($DebugLevel > 2) {
1573: print $fh "Active connection statuses: \n";
1574: my $i = 1;
1575: print STDERR "================================= Socket Status Dump:\n";
1576: foreach my $item (keys %ActiveConnections) {
1577: my $Socket = $ActiveConnections{$item}->data;
1578: my $state = $Socket->GetState();
1579: print $fh "Connection $i State: $state\n";
1580: print STDERR "---------------------- Connection $i \n";
1.48 foxr 1581: $Socket->Dump(-1); # Ensure it gets dumped..
1.46 albertel 1582: $i++;
1583: }
1.38 foxr 1584: }
1.22 foxr 1585: $ConnectionRetriesLeft = $ConnectionRetries;
1.14 foxr 1586: }
1587:
1.1 foxr 1588: =pod
1.3 albertel 1589:
1.10 foxr 1590: =head2 SignalledToDeath
1591:
1592: Called in response to a signal that causes a chid process to die.
1593:
1594: =cut
1595:
1596:
1597: sub SignalledToDeath {
1.14 foxr 1598: my $event = shift;
1599: my $watcher= $event->w;
1600:
1601: Debug(2,"Signalled to death! via ".$watcher->data);
1.17 foxr 1602: my ($signal) = $watcher->data;
1.10 foxr 1603: chomp($signal);
1604: Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "
1605: ."died through "."\"$signal\"");
1606: LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
1607: ."\"$signal\"");
1.12 foxr 1608: exit 0;
1.10 foxr 1609:
1610: }
1.16 foxr 1611:
1612: =head2 ToggleDebug
1613:
1614: This sub toggles trace debugging on and off.
1615:
1616: =cut
1617:
1618: sub ToggleDebug {
1619: my $Current = $DebugLevel;
1620: $DebugLevel = $NextDebugLevel;
1621: $NextDebugLevel = $Current;
1622:
1623: Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel");
1624:
1625: }
1626:
1.1 foxr 1627: =head2 ChildProcess
1628:
1629: This sub implements a child process for a single lonc daemon.
1.61 foxr 1630: Optional parameter:
1631: $socket - if provided, this is a socket already open for listen
1632: on the client socket. Otherwise, a new listen is set up.
1.1 foxr 1633:
1634: =cut
1635:
1636: sub ChildProcess {
1.62 foxr 1637: # If we are in DieWhenIdle mode, we've inherited all the
1638: # events of our parent and those have to be cancelled or else
1639: # all holy bloody chaos will result.. trust me, I already made
1640: # >that< mistake.
1641:
1642: my $host = GetServerHost();
1643: foreach my $listener (keys %parent_dispatchers) {
1644: my $watcher = $parent_dispatchers{$listener};
1645: my $s = $watcher->fd;
1646: if ($listener ne $host) { # Close everyone but me.
1647: Debug(5, "Closing listen socket for $listener");
1648: $s->close();
1649: }
1650: Debug(5, "Killing watcher for $listener");
1651:
1652: $watcher->cancel();
1653: undef $parent_dispatchers{$listener};
1654:
1655: }
1.64 ! foxr 1656: $I_am_child = 1; # Seems like in spite of it all I may still getting
! 1657: # parent event dispatches.. flag I'm a child.
1.1 foxr 1658:
1659:
1.14 foxr 1660: #
1661: # Signals must be handled by the Event framework...
1.61 foxr 1662: #
1.14 foxr 1663:
1664: Event->signal(signal => "QUIT",
1665: cb => \&SignalledToDeath,
1666: data => "QUIT");
1667: Event->signal(signal => "HUP",
1668: cb => \&ChildStatus,
1669: data => "HUP");
1670: Event->signal(signal => "USR1",
1671: cb => \&ChildStatus,
1672: data => "USR1");
1.39 foxr 1673: Event->signal(signal => "USR2",
1674: cb => \&ToggleTransactionLogging);
1.16 foxr 1675: Event->signal(signal => "INT",
1676: cb => \&ToggleDebug,
1677: data => "INT");
1.1 foxr 1678:
1.62 foxr 1679: # Figure out if we got passed a socket or need to open one to listen for
1680: # client requests.
1681:
1.61 foxr 1682: my ($socket) = @_;
1683: if (!$socket) {
1684:
1685: $socket = SetupLoncListener();
1686: }
1.62 foxr 1687: # Establish an event to listen for client connection requests.
1688:
1689:
1.59 foxr 1690: Event->io(cb => \&NewClient,
1691: poll => 'r',
1692: desc => 'Lonc Listener Unix Socket',
1693: fd => $socket);
1.1 foxr 1694:
1695: $Event::Debuglevel = $DebugLevel;
1696:
1697: Debug(9, "Making initial lond connection for ".$RemoteHost);
1698:
1699: # Setup the initial server connection:
1700:
1.62 foxr 1701: # &MakeLondConnection(); // let first work request do it.
1.10 foxr 1702:
1.62 foxr 1703: # If We are in diwhenidle, need to accept the connection since the
1704: # event may not fire.
1705:
1706: if ($DieWhenIdle) {
1707: &accept_client($socket);
1708: }
1.5 foxr 1709:
1.1 foxr 1710: Debug(9,"Entering event loop");
1711: my $ret = Event::loop(); # Start the main event loop.
1712:
1713:
1.64 ! foxr 1714: &child_exit (-1,"Main event loop exited!!!");
1.1 foxr 1715: }
1716:
1717: # Create a new child for host passed in:
1718:
1719: sub CreateChild {
1.62 foxr 1720: my ($host, $socket) = @_;
1.52 foxr 1721:
1.12 foxr 1722: my $sigset = POSIX::SigSet->new(SIGINT);
1723: sigprocmask(SIG_BLOCK, $sigset);
1.1 foxr 1724: $RemoteHost = $host;
1.9 foxr 1725: Log("CRITICAL", "Forking server for ".$host);
1.23 foxr 1726: my $pid = fork;
1.1 foxr 1727: if($pid) { # Parent
1.17 foxr 1728: $RemoteHost = "Parent";
1.27 foxr 1729: $ChildHash{$pid} = $host;
1.26 foxr 1730: $HostToPid{$host}= $pid;
1.12 foxr 1731: sigprocmask(SIG_UNBLOCK, $sigset);
1732:
1.1 foxr 1733: } else { # child.
1.5 foxr 1734: ShowStatus("Connected to ".$RemoteHost);
1.23 foxr 1735: $SIG{INT} = 'DEFAULT';
1.12 foxr 1736: sigprocmask(SIG_UNBLOCK, $sigset);
1.62 foxr 1737: if(defined $socket) {
1738: &ChildProcess($socket);
1739: } else {
1740: ChildProcess; # Does not return.
1741: }
1.1 foxr 1742: }
1.61 foxr 1743: }
1.1 foxr 1744:
1.61 foxr 1745: # parent_client_connection:
1746: # Event handler that processes client connections for the parent process.
1747: # This sub is called when the parent is listening on a socket and
1748: # a connection request arrives. We must:
1749: # Start a child process to accept the connection request.
1750: # Kill our listen on the socket.
1751: # Parameter:
1752: # event - The event object that was created to monitor this socket.
1753: # event->w->fd is the socket.
1754: # Returns:
1755: # NONE
1756: #
1757: sub parent_client_connection {
1.62 foxr 1758: if ($I_am_child) {
1759: # Should not get here, but seem to anyway:
1760: &Debug(5," Child caught parent client connection event!!");
1761: my ($event) = @_;
1762: my $watcher = $event->w;
1763: $watcher->cancel(); # Try to kill it off again!!
1764: } else {
1765: &Debug(9, "parent_client_connection");
1766: my ($event) = @_;
1767: my $watcher = $event->w;
1768: my $socket = $watcher->fd;
1769:
1770: # Lookup the host associated with this socket:
1771:
1772: my $host = $listening_to{$socket};
1773:
1774: # Start the child:
1775:
1776:
1777:
1778: &Debug(9,"Creating child for $host (parent_client_connection)");
1779: &CreateChild($host, $socket);
1780:
1781: # Clean up the listen since now the child takes over until it exits.
1782:
1783: $watcher->cancel(); # Nolonger listening to this event
1784: delete($listening_to{$socket});
1785: delete($parent_dispatchers{$host});
1786: $socket->close();
1787: }
1.61 foxr 1788: }
1789:
1790: # parent_listen:
1791: # Opens a socket and starts a listen for the parent process on a client UNIX
1792: # domain socket.
1793: #
1794: # This involves:
1795: # Creating a socket for listen.
1796: # Removing any socket lock file
1797: # Adding an event handler for this socket becoming readable
1798: # To the parent's event dispatcher.
1799: # Parameters:
1800: # loncapa_host - LonCAPA cluster name of the host represented by the client
1801: # socket.
1802: # Returns:
1803: # NONE
1804: #
1805: sub parent_listen {
1806: my ($loncapa_host) = @_;
1807: Debug(5, "parent_listen: $loncapa_host");
1808:
1809: my $socket = &SetupLoncListener($loncapa_host);
1.62 foxr 1810: $listening_to{$socket} = $loncapa_host;
1.61 foxr 1811: if (!$socket) {
1812: die "Unable to create a listen socket for $loncapa_host";
1813: }
1814:
1.62 foxr 1815: my $lock_file = &GetLoncSocketPath($loncapa_host).".lock";
1.61 foxr 1816: unlink($lock_file); # No problem if it doesn't exist yet [startup e.g.]
1817:
1.62 foxr 1818: my $watcher = Event->io(cb => \&parent_client_connection,
1.61 foxr 1819: poll => 'r',
1.62 foxr 1820: desc => "Parent listener unix socket ($loncapa_host)",
1.61 foxr 1821: fd => $socket);
1.62 foxr 1822: $parent_dispatchers{$loncapa_host} = $watcher;
1.61 foxr 1823:
1824: }
1825:
1826:
1827: # listen_on_all_unix_sockets:
1828: # This sub initiates a listen on all unix domain lonc client sockets.
1829: # This will be called in the case where we are trimming idle processes.
1830: # When idle processes are trimmed, loncnew starts up with no children,
1831: # and only spawns off children when a connection request occurs on the
1832: # client unix socket. The spawned child continues to run until it has
1833: # been idle a while at which point it eventually exits and once more
1834: # the parent picks up the listen.
1835: #
1836: # Parameters:
1837: # NONE
1838: # Implicit Inputs:
1839: # The configuration file that has been read in by LondConnection.
1840: # Returns:
1841: # NONE
1842: #
1843: sub listen_on_all_unix_sockets {
1844: Debug(5, "listen_on_all_unix_sockets");
1845: my $host_iterator = &LondConnection::GetHostIterator();
1846: while (!$host_iterator->end()) {
1847: my $host_entry_ref = $host_iterator->get();
1848: my $host_name = $host_entry_ref->[0];
1849: Debug(9, "Listen for $host_name");
1850: &parent_listen($host_name);
1851: $host_iterator->next();
1852: }
1.1 foxr 1853: }
1.61 foxr 1854:
1.63 foxr 1855: # server_died is called whenever a child process exits.
1856: # Since this is dispatched via a signal, we must process all
1857: # dead children until there are no more left. The action
1858: # is to:
1859: # - Remove the child from the bookeeping hashes
1860: # - Re-establish a listen on the unix domain socket associated
1861: # with that host.
1862: # Parameters:
1863: # The event, but we don't actually care about it.
1864: sub server_died {
1865: &Debug(9, "server_died called...");
1866:
1867: while(1) { # Loop until waitpid nowait fails.
1868: my $pid = waitpid(-1, WNOHANG);
1869: if($pid <= 0) {
1870: return; # Nothing left to wait for.
1871: }
1872: # need the host to restart:
1873:
1874: my $host = $ChildHash{$pid};
1875: if($host) { # It's for real...
1876: &Debug(9, "Caught sigchild for $host");
1877: delete($ChildHash{$pid});
1878: delete($HostToPid{$host});
1879: &parent_listen($host);
1880:
1881: } else {
1882: &Debug(5, "Caught sigchild for pid not in hosts hash: $pid");
1883: }
1884: }
1885:
1886: }
1887:
1.1 foxr 1888: #
1889: # Parent process logic pass 1:
1890: # For each entry in the hosts table, we will
1891: # fork off an instance of ChildProcess to service the transactions
1892: # to that host. Each pid will be entered in a global hash
1893: # with the value of the key, the host.
1894: # The parent will then enter a loop to wait for process exits.
1895: # Each exit gets logged and the child gets restarted.
1896: #
1897:
1.5 foxr 1898: #
1899: # Fork and start in new session so hang-up isn't going to
1900: # happen without intent.
1901: #
1902:
1903:
1.6 foxr 1904:
1905:
1.8 foxr 1906:
1.6 foxr 1907:
1908: ShowStatus("Forming new session");
1909: my $childpid = fork;
1910: if ($childpid != 0) {
1911: sleep 4; # Give child a chacne to break to
1912: exit 0; # a new sesion.
1913: }
1.8 foxr 1914: #
1915: # Write my pid into the pid file so I can be located
1916: #
1917:
1918: ShowStatus("Parent writing pid file:");
1.23 foxr 1919: my $execdir = $perlvar{'lonDaemons'};
1.8 foxr 1920: open (PIDSAVE, ">$execdir/logs/lonc.pid");
1921: print PIDSAVE "$$\n";
1922: close(PIDSAVE);
1.6 foxr 1923:
1.17 foxr 1924:
1925:
1.6 foxr 1926: if (POSIX::setsid() < 0) {
1927: print "Could not create new session\n";
1928: exit -1;
1929: }
1.5 foxr 1930:
1931: ShowStatus("Forking node servers");
1932:
1.9 foxr 1933: Log("CRITICAL", "--------------- Starting children ---------------");
1934:
1.31 foxr 1935: LondConnection::ReadConfig; # Read standard config files.
1.1 foxr 1936: my $HostIterator = LondConnection::GetHostIterator;
1937:
1.60 foxr 1938: if ($DieWhenIdle) {
1.61 foxr 1939: $RemoteHost = "[parent]";
1940: &listen_on_all_unix_sockets();
1.60 foxr 1941: } else {
1942:
1943: while (! $HostIterator->end()) {
1944:
1945: my $hostentryref = $HostIterator->get();
1946: CreateChild($hostentryref->[0]);
1947: $HostHash{$hostentryref->[0]} = $hostentryref->[4];
1948: $HostIterator->next();
1949: }
1.1 foxr 1950: }
1.60 foxr 1951:
1.12 foxr 1952: $RemoteHost = "Parent Server";
1.1 foxr 1953:
1954: # Maintain the population:
1.5 foxr 1955:
1956: ShowStatus("Parent keeping the flock");
1.1 foxr 1957:
1.12 foxr 1958:
1.60 foxr 1959: if ($DieWhenIdle) {
1.63 foxr 1960: # We need to setup a SIGChild event to handle the exit (natural or otherwise)
1961: # of the children.
1962:
1963: Event->signal(cb => \&server_died,
1964: desc => "Child exit handler",
1965: signal => "CHLD");
1966:
1967:
1.61 foxr 1968: $Event::DebugLevel = $DebugLevel;
1969: Debug(9, "Parent entering event loop");
1970: my $ret = Event::loop();
1971: die "Main Event loop exited: $ret";
1972:
1973:
1.60 foxr 1974: } else {
1.61 foxr 1975: #
1976: # Set up parent signals:
1977: #
1.60 foxr 1978:
1979: $SIG{INT} = \&Terminate;
1980: $SIG{TERM} = \&Terminate;
1981: $SIG{HUP} = \&Restart;
1982: $SIG{USR1} = \&CheckKids;
1983: $SIG{USR2} = \&UpdateKids; # LonManage update request.
1984:
1985: while(1) {
1986: my $deadchild = wait();
1987: if(exists $ChildHash{$deadchild}) { # need to restart.
1988: my $deadhost = $ChildHash{$deadchild};
1989: delete($HostToPid{$deadhost});
1990: delete($ChildHash{$deadchild});
1991: Log("WARNING","Lost child pid= ".$deadchild.
1992: "Connected to host ".$deadhost);
1993: Log("INFO", "Restarting child procesing ".$deadhost);
1994: CreateChild($deadhost);
1995: }
1.1 foxr 1996: }
1.13 foxr 1997: }
1998:
1.14 foxr 1999:
2000: =pod
2001:
2002: =head1 CheckKids
2003:
2004: Since kids do not die as easily in this implementation
2005: as the previous one, there is no need to restart the
2006: dead ones (all dead kids get restarted when they die!!)
2007: The only thing this function does is to pass USR1 to the
2008: kids so that they report their status.
2009:
2010: =cut
2011:
2012: sub CheckKids {
2013: Debug(2, "Checking status of children");
2014: my $docdir = $perlvar{'lonDocRoot'};
2015: my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt");
2016: my $now=time;
2017: my $local=localtime($now);
2018: print $fh "LONC status $local - parent $$ \n\n";
1.23 foxr 2019: foreach my $pid (keys %ChildHash) {
1.14 foxr 2020: Debug(2, "Sending USR1 -> $pid");
2021: kill 'USR1' => $pid; # Tell Child to report status.
2022: sleep 1; # Wait so file doesn't intermix.
2023: }
2024: }
1.24 foxr 2025:
2026: =pod
2027:
2028: =head1 UpdateKids
2029:
1.25 foxr 2030: parent's SIGUSR2 handler. This handler:
1.24 foxr 2031:
2032: =item
2033:
2034: Rereads the hosts file.
2035:
2036: =item
2037:
2038: Kills off (via sigint) children for hosts that have disappeared.
2039:
2040: =item
2041:
1.27 foxr 2042: QUITs children for hosts that already exist (this just forces a status display
1.24 foxr 2043: and resets the connection retry count for that host.
2044:
2045: =item
2046:
2047: Starts new children for hosts that have been added to the hosts.tab file since
2048: the start of the master program and maintains them.
2049:
2050: =cut
2051:
2052: sub UpdateKids {
1.27 foxr 2053:
1.25 foxr 2054: Log("INFO", "Updating connections via SIGUSR2");
1.27 foxr 2055:
2056: # Just in case we need to kill our own lonc, we wait a few seconds to
2057: # give it a chance to receive and relay lond's response to the
2058: # re-init command.
2059: #
2060:
2061: sleep(2); # Wait a couple of seconds.
2062:
2063: my %hosts; # Indexed by loncapa hostname, value=ip.
2064:
2065: # Need to re-read the host table:
2066:
2067:
2068: LondConnection::ReadConfig();
2069: my $I = LondConnection::GetHostIterator;
2070: while (! $I->end()) {
2071: my $item = $I->get();
2072: $hosts{$item->[0]} = $item->[4];
2073: $I->next();
2074: }
2075:
2076: # The logic below is written for clarity not for efficiency.
2077: # Since I anticipate that this function is only rarely called, that's
2078: # appropriate. There are certainly ways to combine the loops below,
2079: # and anyone wishing to obscure the logic is welcome to go for it.
2080: # Note that we don't re-direct sigchild. Instead we do what's needed
2081: # to the data structures that keep track of children to ensure that
2082: # when sigchild is honored, no new child is born.
2083: #
2084:
2085: # For each existing child; if it's host doesn't exist, kill the child.
2086:
2087: foreach my $child (keys %ChildHash) {
2088: my $oldhost = $ChildHash{$child};
2089: if (!(exists $hosts{$oldhost})) {
2090: Log("CRITICAL", "Killing child for $oldhost host no longer exists");
2091: delete $ChildHash{$child};
2092: delete $HostToPid{$oldhost};
2093: kill 'QUIT' => $child;
2094: }
2095: }
2096: # For each remaining existing child; if it's host's ip has changed,
2097: # Restart the child on the new IP.
2098:
2099: foreach my $child (keys %ChildHash) {
2100: my $oldhost = $ChildHash{$child};
2101: my $oldip = $HostHash{$oldhost};
2102: if ($hosts{$oldhost} ne $oldip) {
2103:
2104: # kill the old child.
2105:
2106: Log("CRITICAL", "Killing child for $oldhost host ip has changed...");
2107: delete $ChildHash{$child};
2108: delete $HostToPid{$oldhost};
2109: kill 'QUIT' => $child;
2110:
2111: # Do the book-keeping needed to start a new child on the
2112: # new ip.
2113:
2114: $HostHash{$oldhost} = $hosts{$oldhost};
2115: CreateChild($oldhost);
2116: }
2117: }
2118: # Finally, for each new host, not in the host hash, create a
2119: # enter the host and create a new child.
2120: # Force a status display of any existing process.
2121:
2122: foreach my $host (keys %hosts) {
2123: if(!(exists $HostHash{$host})) {
2124: Log("INFO", "New host $host discovered in hosts.tab...");
2125: $HostHash{$host} = $hosts{$host};
2126: CreateChild($host);
2127: } else {
2128: kill 'HUP' => $HostToPid{$host}; # status display.
2129: }
2130: }
1.24 foxr 2131: }
2132:
1.14 foxr 2133:
1.13 foxr 2134: =pod
2135:
2136: =head1 Restart
2137:
2138: Signal handler for HUP... all children are killed and
2139: we self restart. This is an el-cheapo way to re read
2140: the config file.
2141:
2142: =cut
2143:
2144: sub Restart {
1.23 foxr 2145: &KillThemAll; # First kill all the children.
1.13 foxr 2146: Log("CRITICAL", "Restarting");
2147: my $execdir = $perlvar{'lonDaemons'};
2148: unlink("$execdir/logs/lonc.pid");
1.28 albertel 2149: exec("$execdir/loncnew");
1.10 foxr 2150: }
1.12 foxr 2151:
2152: =pod
2153:
2154: =head1 KillThemAll
2155:
2156: Signal handler that kills all children by sending them a
1.17 foxr 2157: SIGHUP. Responds to sigint and sigterm.
1.12 foxr 2158:
2159: =cut
2160:
1.10 foxr 2161: sub KillThemAll {
1.12 foxr 2162: Debug(2, "Kill them all!!");
2163: local($SIG{CHLD}) = 'IGNORE'; # Our children >will< die.
1.23 foxr 2164: foreach my $pid (keys %ChildHash) {
1.12 foxr 2165: my $serving = $ChildHash{$pid};
1.52 foxr 2166: ShowStatus("Nicely Killing lonc for $serving pid = $pid");
2167: Log("CRITICAL", "Nicely Killing lonc for $serving pid = $pid");
1.17 foxr 2168: kill 'QUIT' => $pid;
1.12 foxr 2169: }
1.52 foxr 2170:
1.17 foxr 2171:
1.1 foxr 2172: }
1.12 foxr 2173:
1.52 foxr 2174:
2175: #
2176: # Kill all children via KILL. Just in case the
2177: # first shot didn't get them.
2178:
2179: sub really_kill_them_all_dammit
2180: {
2181: Debug(2, "Kill them all Dammit");
2182: local($SIG{CHLD} = 'IGNORE'); # In case some purist reenabled them.
2183: foreach my $pid (keys %ChildHash) {
2184: my $serving = $ChildHash{$pid};
2185: &ShowStatus("Nastily killing lonc for $serving pid = $pid");
2186: Log("CRITICAL", "Nastily killing lonc for $serving pid = $pid");
2187: kill 'KILL' => $pid;
2188: delete($ChildHash{$pid});
2189: my $execdir = $perlvar{'lonDaemons'};
2190: unlink("$execdir/logs/lonc.pid");
2191: }
2192: }
1.14 foxr 2193: =pod
2194:
2195: =head1 Terminate
2196:
2197: Terminate the system.
2198:
2199: =cut
2200:
2201: sub Terminate {
1.52 foxr 2202: &Log("CRITICAL", "Asked to kill children.. first be nice...");
2203: &KillThemAll;
2204: #
2205: # By now they really should all be dead.. but just in case
2206: # send them all SIGKILL's after a bit of waiting:
2207:
2208: sleep(4);
2209: &Log("CRITICAL", "Now kill children nasty");
2210: &really_kill_them_all_dammit;
1.17 foxr 2211: Log("CRITICAL","Master process exiting");
2212: exit 0;
1.14 foxr 2213:
2214: }
1.12 foxr 2215: =pod
1.1 foxr 2216:
2217: =head1 Theory
1.3 albertel 2218:
2219: The event class is used to build this as a single process with an
2220: event driven model. The following events are handled:
1.1 foxr 2221:
2222: =item UNIX Socket connection Received
2223:
2224: =item Request data arrives on UNIX data transfer socket.
2225:
2226: =item lond connection becomes writable.
2227:
2228: =item timer fires at 1 second intervals.
2229:
2230: All sockets are run in non-blocking mode. Timeouts managed by the timer
2231: handler prevents hung connections.
2232:
2233: Key data structures:
2234:
1.3 albertel 2235: =item RequestQueue
2236:
2237: A queue of requests received from UNIX sockets that are
2238: waiting for a chance to be forwarded on a lond connection socket.
2239:
2240: =item ActiveConnections
2241:
2242: A hash of lond connections that have transactions in process that are
2243: available to be timed out.
2244:
2245: =item ActiveTransactions
2246:
2247: A hash indexed by lond connections that contain the client reply
2248: socket for each connection that has an active transaction on it.
2249:
2250: =item IdleConnections
2251:
2252: A hash of lond connections that have no work to do. These connections
2253: can be closed if they are idle for a long enough time.
1.1 foxr 2254:
2255: =cut
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