Annotation of loncom/loncnew, revision 1.90
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: #
1.90 ! foxr 5: # $Id: loncnew,v 1.89 2010/06/14 13:29:27 www 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;
1.67 albertel 63: use Fcntl qw(:flock);
1.1 foxr 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:
1.83 albertel 75: my %ChildPid; # by pid -> host.
76: my %ChildHost; # by host.
1.62 foxr 77: my %listening_to; # Socket->host table for who the parent
78: # is listening to.
79: my %parent_dispatchers; # host-> listener watcher events.
1.1 foxr 80:
1.65 foxr 81: my %parent_handlers; # Parent signal handlers...
82:
1.9 foxr 83: my $MaxConnectionCount = 10; # Will get from config later.
1.1 foxr 84: my $ClientConnection = 0; # Uniquifier for client events.
85:
1.9 foxr 86: my $DebugLevel = 0;
1.29 foxr 87: my $NextDebugLevel= 2; # So Sigint can toggle this.
1.89 www 88: my $IdleTimeout= 7200; # Wait two hours before pruning connections.
1.1 foxr 89:
1.39 foxr 90: my $LogTransactions = 0; # When True, all transactions/replies get logged.
1.65 foxr 91: my $executable = $0; # Get the full path to me.
1.39 foxr 92:
1.1 foxr 93: #
94: # The variables below are only used by the child processes.
95: #
96: my $RemoteHost; # Name of host child is talking to.
1.81 albertel 97: my $RemoteHostId; # default lonid of host child is talking to.
1.82 albertel 98: my @all_host_ids;
1.20 albertel 99: my $UnixSocketDir= $perlvar{'lonSockDir'};
1.1 foxr 100: my $IdleConnections = Stack->new(); # Set of idle connections
101: my %ActiveConnections; # Connections to the remote lond.
1.7 foxr 102: my %ActiveTransactions; # LondTransactions in flight.
1.1 foxr 103: my %ActiveClients; # Serial numbers of active clients by socket.
104: my $WorkQueue = Queue->new(); # Queue of pending transactions.
105: my $ConnectionCount = 0;
1.4 foxr 106: my $IdleSeconds = 0; # Number of seconds idle.
1.9 foxr 107: my $Status = ""; # Current status string.
1.14 foxr 108: my $RecentLogEntry = "";
1.72 albertel 109: my $ConnectionRetries=5; # Number of connection retries allowed.
110: my $ConnectionRetriesLeft=5; # Number of connection retries remaining.
1.40 foxr 111: my $LondVersion = "unknown"; # Version of lond we talk with.
1.49 foxr 112: my $KeyMode = ""; # e.g. ssl, local, insecure from last connect.
1.54 foxr 113: my $LondConnecting = 0; # True when a connection is being built.
1.1 foxr 114:
1.60 foxr 115:
116:
1.62 foxr 117: my $I_am_child = 0; # True if this is the child process.
1.57 foxr 118:
1.1 foxr 119: #
1.9 foxr 120: # The hash below gives the HTML format for log messages
121: # given a severity.
122: #
123: my %LogFormats;
124:
1.45 albertel 125: $LogFormats{"CRITICAL"} = "<font color='red'>CRITICAL: %s</font>";
126: $LogFormats{"SUCCESS"} = "<font color='green'>SUCCESS: %s</font>";
127: $LogFormats{"INFO"} = "<font color='yellow'>INFO: %s</font>";
128: $LogFormats{"WARNING"} = "<font color='blue'>WARNING: %s</font>";
1.9 foxr 129: $LogFormats{"DEFAULT"} = " %s ";
130:
1.10 foxr 131:
1.57 foxr 132: # UpdateStatus;
133: # Update the idle status display to show how many connections
134: # are left, retries and other stuff.
135: #
136: sub UpdateStatus {
137: if ($ConnectionRetriesLeft > 0) {
138: ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
139: ." Retries remaining: ".$ConnectionRetriesLeft
140: ." ($KeyMode)");
141: } else {
142: ShowStatus(GetServerHost()." >> DEAD <<");
143: }
144: }
145:
1.10 foxr 146:
147: =pod
148:
149: =head2 LogPerm
150:
151: Makes an entry into the permanent log file.
152:
153: =cut
1.69 matthew 154:
1.10 foxr 155: sub LogPerm {
156: my $message=shift;
157: my $execdir=$perlvar{'lonDaemons'};
158: my $now=time;
159: my $local=localtime($now);
160: my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
1.86 albertel 161: chomp($message);
1.10 foxr 162: print $fh "$now:$message:$local\n";
163: }
1.9 foxr 164:
165: =pod
166:
167: =head2 Log
168:
169: Logs a message to the log file.
170: Parameters:
171:
172: =item severity
173:
174: One of CRITICAL, WARNING, INFO, SUCCESS used to select the
175: format string used to format the message. if the severity is
176: not a defined severity the Default format string is used.
177:
178: =item message
179:
180: The base message. In addtion to the format string, the message
181: will be appended to a string containing the name of our remote
182: host and the time will be formatted into the message.
183:
184: =cut
185:
186: sub Log {
1.47 foxr 187:
188: my ($severity, $message) = @_;
189:
1.9 foxr 190: if(!$LogFormats{$severity}) {
191: $severity = "DEFAULT";
192: }
193:
194: my $format = $LogFormats{$severity};
195:
196: # Put the window dressing in in front of the message format:
197:
198: my $now = time;
199: my $local = localtime($now);
200: my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
1.76 albertel 201: $finalformat = $finalformat.$format."\n";
1.9 foxr 202:
203: # open the file and put the result.
204:
205: my $execdir = $perlvar{'lonDaemons'};
206: my $fh = IO::File->new(">>$execdir/logs/lonc.log");
207: my $msg = sprintf($finalformat, $message);
1.14 foxr 208: $RecentLogEntry = $msg;
1.9 foxr 209: print $fh $msg;
210:
1.10 foxr 211:
1.9 foxr 212: }
1.6 foxr 213:
1.3 albertel 214:
1.1 foxr 215: =pod
1.3 albertel 216:
217: =head2 GetPeerName
218:
219: Returns the name of the host that a socket object is connected to.
220:
1.1 foxr 221: =cut
222:
223: sub GetPeername {
1.47 foxr 224:
225:
226: my ($connection, $AdrFamily) = @_;
227:
1.1 foxr 228: my $peer = $connection->peername();
229: my $peerport;
230: my $peerip;
231: if($AdrFamily == AF_INET) {
232: ($peerport, $peerip) = sockaddr_in($peer);
1.23 foxr 233: my $peername = gethostbyaddr($peerip, $AdrFamily);
1.1 foxr 234: return $peername;
235: } elsif ($AdrFamily == AF_UNIX) {
236: my $peerfile;
237: ($peerfile) = sockaddr_un($peer);
238: return $peerfile;
239: }
240: }
241: =pod
1.3 albertel 242:
1.1 foxr 243: =head2 Debug
1.3 albertel 244:
245: Invoked to issue a debug message.
246:
1.1 foxr 247: =cut
1.3 albertel 248:
1.1 foxr 249: sub Debug {
1.47 foxr 250:
251: my ($level, $message) = @_;
252:
1.1 foxr 253: if ($level <= $DebugLevel) {
1.23 foxr 254: Log("INFO", "-Debug- $message host = $RemoteHost");
1.1 foxr 255: }
256: }
257:
258: sub SocketDump {
1.47 foxr 259:
260: my ($level, $socket) = @_;
261:
1.1 foxr 262: if($level <= $DebugLevel) {
1.48 foxr 263: $socket->Dump(-1); # Ensure it will get dumped.
1.1 foxr 264: }
265: }
1.3 albertel 266:
1.1 foxr 267: =pod
1.3 albertel 268:
1.5 foxr 269: =head2 ShowStatus
270:
271: Place some text as our pid status.
1.10 foxr 272: and as what we return in a SIGUSR1
1.5 foxr 273:
274: =cut
1.69 matthew 275:
1.5 foxr 276: sub ShowStatus {
1.10 foxr 277: my $state = shift;
278: my $now = time;
279: my $local = localtime($now);
280: $Status = $local.": ".$state;
281: $0='lonc: '.$state.' '.$local;
1.5 foxr 282: }
283:
284: =pod
285:
1.69 matthew 286: =head2 SocketTimeout
1.15 foxr 287:
288: Called when an action on the socket times out. The socket is
289: destroyed and any active transaction is failed.
290:
291:
292: =cut
1.69 matthew 293:
1.15 foxr 294: sub SocketTimeout {
295: my $Socket = shift;
1.38 foxr 296: Log("WARNING", "A socket timeout was detected");
1.52 foxr 297: Debug(5, " SocketTimeout called: ");
1.48 foxr 298: $Socket->Dump(0);
1.42 foxr 299: if(exists($ActiveTransactions{$Socket})) {
1.43 albertel 300: FailTransaction($ActiveTransactions{$Socket});
1.42 foxr 301: }
1.22 foxr 302: KillSocket($Socket); # A transaction timeout also counts as
303: # a connection failure:
304: $ConnectionRetriesLeft--;
1.42 foxr 305: if($ConnectionRetriesLeft <= 0) {
1.52 foxr 306: Log("CRITICAL", "Host marked DEAD: ".GetServerHost());
1.56 foxr 307: $LondConnecting = 0;
1.42 foxr 308: }
309:
1.15 foxr 310: }
1.80 albertel 311:
1.64 foxr 312: #
313: # This function should be called by the child in all cases where it must
1.80 albertel 314: # exit. The child process must create a lock file for the AF_UNIX socket
315: # in order to prevent connection requests from lonnet in the time between
316: # process exit and the parent picking up the listen again.
317: #
1.64 foxr 318: # Parameters:
319: # exit_code - Exit status value, however see the next parameter.
320: # message - If this optional parameter is supplied, the exit
321: # is via a die with this message.
322: #
323: sub child_exit {
324: my ($exit_code, $message) = @_;
325:
326: # Regardless of how we exit, we may need to do the lock thing:
327:
1.80 albertel 328: #
329: # Create a lock file since there will be a time window
330: # between our exit and the parent's picking up the listen
331: # during which no listens will be done on the
332: # lonnet client socket.
333: #
334: my $lock_file = &GetLoncSocketPath().".lock";
335: open(LOCK,">$lock_file");
336: print LOCK "Contents not important";
337: close(LOCK);
1.81 albertel 338: unlink(&GetLoncSocketPath());
1.64 foxr 339:
1.80 albertel 340: if ($message) {
341: die($message);
1.64 foxr 342: } else {
343: exit($exit_code);
344: }
345: }
1.35 foxr 346: #----------------------------- Timer management ------------------------
1.15 foxr 347:
348: =pod
349:
1.1 foxr 350: =head2 Tick
1.3 albertel 351:
352: Invoked each timer tick.
353:
1.1 foxr 354: =cut
355:
1.5 foxr 356:
1.1 foxr 357: sub Tick {
1.52 foxr 358: my ($Event) = @_;
359: my $clock_watcher = $Event->w;
360:
1.1 foxr 361: my $client;
1.57 foxr 362: UpdateStatus();
363:
1.4 foxr 364: # Is it time to prune connection count:
365:
366:
367: if($IdleConnections->Count() &&
368: ($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
1.52 foxr 369: $IdleSeconds++;
1.4 foxr 370: if($IdleSeconds > $IdleTimeout) { # Prune a connection...
1.23 foxr 371: my $Socket = $IdleConnections->pop();
1.6 foxr 372: KillSocket($Socket);
1.54 foxr 373: $IdleSeconds = 0; # Otherwise all connections get trimmed to fast.
1.57 foxr 374: UpdateStatus();
1.80 albertel 375: if(($ConnectionCount == 0)) {
1.64 foxr 376: &child_exit(0);
377:
1.57 foxr 378: }
1.4 foxr 379: }
380: } else {
381: $IdleSeconds = 0; # Reset idle count if not idle.
382: }
1.15 foxr 383: #
384: # For each inflight transaction, tick down its timeout counter.
385: #
1.35 foxr 386:
1.34 albertel 387: foreach my $item (keys %ActiveConnections) {
388: my $State = $ActiveConnections{$item}->data->GetState();
1.35 foxr 389: if ($State ne 'Idle') {
1.34 albertel 390: Debug(5,"Ticking Socket $State $item");
391: $ActiveConnections{$item}->data->Tick();
392: }
1.15 foxr 393: }
1.5 foxr 394: # Do we have work in the queue, but no connections to service them?
395: # If so, try to make some new connections to get things going again.
396: #
1.57 foxr 397: # Note this code is dead now...
398: #
1.5 foxr 399: my $Requests = $WorkQueue->Count();
1.56 foxr 400: if (($ConnectionCount == 0) && ($Requests > 0) && (!$LondConnecting)) {
1.10 foxr 401: if ($ConnectionRetriesLeft > 0) {
1.56 foxr 402: Debug(5,"Work but no connections, Make a new one");
403: my $success;
404: $success = &MakeLondConnection;
405: if($success == 0) { # All connections failed:
1.29 foxr 406: Debug(5,"Work in queue failed to make any connectiouns\n");
1.22 foxr 407: EmptyQueue(); # Fail pending transactions with con_lost.
1.42 foxr 408: CloseAllLondConnections(); # Should all be closed but....
1.10 foxr 409: }
410: } else {
1.56 foxr 411: $LondConnecting = 0;
1.22 foxr 412: ShowStatus(GetServerHost()." >>> DEAD!!! <<<");
1.29 foxr 413: Debug(5,"Work in queue, but gave up on connections..flushing\n");
1.10 foxr 414: EmptyQueue(); # Connections can't be established.
1.42 foxr 415: CloseAllLondConnections(); # Should all already be closed but...
1.5 foxr 416: }
417:
418: }
1.49 foxr 419: if ($ConnectionCount == 0) {
420: $KeyMode = "";
1.52 foxr 421: $clock_watcher->cancel();
1.49 foxr 422: }
1.66 albertel 423: &UpdateStatus();
1.1 foxr 424: }
425:
426: =pod
1.3 albertel 427:
1.1 foxr 428: =head2 SetupTimer
429:
1.3 albertel 430: Sets up a 1 per sec recurring timer event. The event handler is used to:
1.1 foxr 431:
1.3 albertel 432: =item
433:
434: Trigger timeouts on communications along active sockets.
435:
436: =item
437:
438: Trigger disconnections of idle sockets.
1.1 foxr 439:
440: =cut
441:
442: sub SetupTimer {
1.52 foxr 443: Debug(6, "SetupTimer");
444: Event->timer(interval => 1, cb => \&Tick );
1.1 foxr 445: }
1.3 albertel 446:
1.1 foxr 447: =pod
1.3 albertel 448:
1.1 foxr 449: =head2 ServerToIdle
1.3 albertel 450:
451: This function is called when a connection to the server is
452: ready for more work.
453:
454: If there is work in the Work queue the top element is dequeued
1.1 foxr 455: and the connection will start to work on it. If the work queue is
456: empty, the connection is pushed on the idle connection stack where
457: it will either get another work unit, or alternatively, if it sits there
458: long enough, it will be shut down and released.
459:
1.3 albertel 460: =cut
1.1 foxr 461:
462: sub ServerToIdle {
463: my $Socket = shift; # Get the socket.
1.49 foxr 464: $KeyMode = $Socket->{AuthenticationMode};
1.7 foxr 465: delete($ActiveTransactions{$Socket}); # Server has no transaction
1.1 foxr 466:
1.29 foxr 467: &Debug(5, "Server to idle");
1.1 foxr 468:
469: # If there's work to do, start the transaction:
470:
1.23 foxr 471: my $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
1.29 foxr 472: if ($reqdata ne undef) {
473: Debug(5, "Queue gave request data: ".$reqdata->getRequest());
1.7 foxr 474: &StartRequest($Socket, $reqdata);
1.8 foxr 475:
1.1 foxr 476: } else {
477:
478: # There's no work waiting, so push the server to idle list.
1.29 foxr 479: &Debug(5, "No new work requests, server connection going idle");
1.1 foxr 480: $IdleConnections->push($Socket);
481: }
482: }
1.3 albertel 483:
1.1 foxr 484: =pod
1.3 albertel 485:
1.1 foxr 486: =head2 ClientWritable
1.3 albertel 487:
488: Event callback for when a client socket is writable.
489:
490: This callback is established when a transaction reponse is
491: avaiable from lond. The response is forwarded to the unix socket
492: as it becomes writable in this sub.
493:
1.1 foxr 494: Parameters:
495:
1.3 albertel 496: =item Event
497:
498: The event that has been triggered. Event->w->data is
499: the data and Event->w->fd is the socket to write.
1.1 foxr 500:
501: =cut
1.3 albertel 502:
1.1 foxr 503: sub ClientWritable {
504: my $Event = shift;
505: my $Watcher = $Event->w;
1.84 albertel 506: if (!defined($Watcher)) {
507: &child_exit(-1,'No watcher for event in ClientWritable');
508: }
1.1 foxr 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!!
1.52 foxr 547: # Log("INFO", "lonc pipe client hung up on us!");
1.15 foxr 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.
1.84 albertel 572: return;
1.1 foxr 573: }
574: }
575:
576: =pod
1.3 albertel 577:
1.1 foxr 578: =head2 CompleteTransaction
1.3 albertel 579:
580: Called when the reply data has been received for a lond
1.1 foxr 581: transaction. The reply data must now be sent to the
582: ultimate client on the other end of the Unix socket. This is
583: done by setting up a writable event for the socket with the
584: data the reply data.
1.3 albertel 585:
1.1 foxr 586: Parameters:
1.3 albertel 587:
588: =item Socket
589:
590: Socket on which the lond transaction occured. This is a
591: LondConnection. The data received is in the TransactionReply member.
592:
1.7 foxr 593: =item Transaction
1.3 albertel 594:
1.7 foxr 595: The transaction that is being completed.
1.1 foxr 596:
597: =cut
1.3 albertel 598:
1.1 foxr 599: sub CompleteTransaction {
1.29 foxr 600: &Debug(5,"Complete transaction");
1.47 foxr 601:
602: my ($Socket, $Transaction) = @_;
1.1 foxr 603:
1.7 foxr 604: if (!$Transaction->isDeferred()) { # Normal transaction
605: my $data = $Socket->GetReply(); # Data to send.
1.39 foxr 606: if($LogTransactions) {
607: Log("SUCCESS", "Reply from lond: '$data'");
608: }
1.7 foxr 609: StartClientReply($Transaction, $data);
610: } else { # Delete deferred transaction file.
1.9 foxr 611: Log("SUCCESS", "A delayed transaction was completed");
1.86 albertel 612: LogPerm("S:".$Transaction->getClient().":".$Transaction->getRequest());
613: unlink($Transaction->getFile());
1.7 foxr 614: }
1.6 foxr 615: }
1.42 foxr 616:
1.6 foxr 617: =pod
1.42 foxr 618:
1.6 foxr 619: =head1 StartClientReply
620:
621: Initiates a reply to a client where the reply data is a parameter.
622:
1.7 foxr 623: =head2 parameters:
624:
625: =item Transaction
626:
627: The transaction for which we are responding to the client.
628:
629: =item data
630:
631: The data to send to apached client.
632:
1.6 foxr 633: =cut
1.42 foxr 634:
1.6 foxr 635: sub StartClientReply {
1.1 foxr 636:
1.47 foxr 637: my ($Transaction, $data) = @_;
1.12 foxr 638:
1.7 foxr 639: my $Client = $Transaction->getClient();
640:
1.1 foxr 641: &Debug(8," Reply was: ".$data);
642: my $Serial = $ActiveClients{$Client};
643: my $desc = sprintf("Connection to lonc client %d",
644: $Serial);
645: Event->io(fd => $Client,
646: poll => "w",
647: desc => $desc,
648: cb => \&ClientWritable,
649: data => $data);
650: }
1.42 foxr 651:
1.4 foxr 652: =pod
1.42 foxr 653:
1.4 foxr 654: =head2 FailTransaction
655:
656: Finishes a transaction with failure because the associated lond socket
1.7 foxr 657: disconnected. There are two possibilities:
658: - The transaction is deferred: in which case we just quietly
659: delete the transaction since there is no client connection.
660: - The transaction is 'live' in which case we initiate the sending
661: of "con_lost" to the client.
662:
1.42 foxr 663: Deleting the transaction means killing it from the %ActiveTransactions hash.
1.4 foxr 664:
665: Parameters:
666:
667: =item client
668:
1.7 foxr 669: The LondTransaction we are failing.
670:
1.42 foxr 671:
1.4 foxr 672: =cut
673:
674: sub FailTransaction {
1.7 foxr 675: my $transaction = shift;
1.52 foxr 676:
677: # If the socket is dead, that's already logged.
678:
679: if ($ConnectionRetriesLeft > 0) {
680: Log("WARNING", "Failing transaction "
1.71 albertel 681: .$transaction->getLoggableRequest());
1.52 foxr 682: }
1.71 albertel 683: Debug(1, "Failing transaction: ".$transaction->getLoggableRequest());
1.10 foxr 684: if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
1.11 foxr 685: my $client = $transaction->getClient();
1.30 foxr 686: Debug(1," Replying con_lost to ".$transaction->getRequest());
1.11 foxr 687: StartClientReply($transaction, "con_lost\n");
1.7 foxr 688: }
1.4 foxr 689:
690: }
691:
692: =pod
1.69 matthew 693:
1.6 foxr 694: =head1 EmptyQueue
1.7 foxr 695:
1.6 foxr 696: Fails all items in the work queue with con_lost.
1.7 foxr 697: Note that each item in the work queue is a transaction.
698:
1.6 foxr 699: =cut
1.69 matthew 700:
1.6 foxr 701: sub EmptyQueue {
1.22 foxr 702: $ConnectionRetriesLeft--; # Counts as connection failure too.
1.6 foxr 703: while($WorkQueue->Count()) {
1.10 foxr 704: my $request = $WorkQueue->dequeue(); # This is a transaction
1.7 foxr 705: FailTransaction($request);
1.6 foxr 706: }
707: }
708:
709: =pod
1.4 foxr 710:
1.9 foxr 711: =head2 CloseAllLondConnections
712:
713: Close all connections open on lond prior to exit e.g.
714:
715: =cut
1.69 matthew 716:
1.9 foxr 717: sub CloseAllLondConnections {
1.23 foxr 718: foreach my $Socket (keys %ActiveConnections) {
1.42 foxr 719: if(exists($ActiveTransactions{$Socket})) {
720: FailTransaction($ActiveTransactions{$Socket});
721: }
722: KillSocket($Socket);
1.9 foxr 723: }
724: }
725:
726: =pod
727:
1.4 foxr 728: =head2 KillSocket
729:
730: Destroys a socket. This function can be called either when a socket
731: has died of 'natural' causes or because a socket needs to be pruned due to
732: idleness. If the socket has died naturally, if there are no longer any
733: live connections a new connection is created (in case there are transactions
734: in the queue). If the socket has been pruned, it is never re-created.
735:
736: Parameters:
1.1 foxr 737:
1.4 foxr 738: =item Socket
739:
740: The socket to kill off.
741:
742: =item Restart
743:
744: nonzero if we are allowed to create a new connection.
745:
1.69 matthew 746: =cut
1.4 foxr 747:
748: sub KillSocket {
749: my $Socket = shift;
750:
1.17 foxr 751: Log("WARNING", "Shutting down a socket");
1.9 foxr 752: $Socket->Shutdown();
753:
1.7 foxr 754: # If the socket came from the active connection set,
755: # delete its transaction... note that FailTransaction should
756: # already have been called!!!
757: # otherwise it came from the idle set.
758: #
1.4 foxr 759:
760: if(exists($ActiveTransactions{$Socket})) {
761: delete ($ActiveTransactions{$Socket});
762: }
763: if(exists($ActiveConnections{$Socket})) {
1.90 ! foxr 764: $ActiveConnections{$Socket}->cancel;
1.4 foxr 765: delete($ActiveConnections{$Socket});
1.37 albertel 766: $ConnectionCount--;
767: if ($ConnectionCount < 0) { $ConnectionCount = 0; }
1.4 foxr 768: }
1.6 foxr 769: # If the connection count has gone to zero and there is work in the
770: # work queue, the work all gets failed with con_lost.
771: #
772: if($ConnectionCount == 0) {
1.22 foxr 773: EmptyQueue();
1.42 foxr 774: CloseAllLondConnections; # Should all already be closed but...
1.4 foxr 775: }
1.90 ! foxr 776: UpdateStatus();
1.4 foxr 777: }
1.1 foxr 778:
779: =pod
1.3 albertel 780:
1.1 foxr 781: =head2 LondReadable
1.3 albertel 782:
1.1 foxr 783: This function is called whenever a lond connection
784: is readable. The action is state dependent:
785:
1.3 albertel 786: =head3 State=Initialized
787:
788: We''re waiting for the challenge, this is a no-op until the
1.1 foxr 789: state changes.
1.3 albertel 790:
1.1 foxr 791: =head3 State=Challenged
1.3 albertel 792:
793: The challenge has arrived we need to transition to Writable.
1.1 foxr 794: The connection must echo the challenge back.
1.3 albertel 795:
1.1 foxr 796: =head3 State=ChallengeReplied
1.3 albertel 797:
798: The challenge has been replied to. The we are receiveing the
1.1 foxr 799: 'ok' from the partner.
1.3 albertel 800:
1.40 foxr 801: =head3 State=ReadingVersionString
802:
803: We have requested the lond version and are reading the
804: version back. Upon completion, we'll store the version away
805: for future use(?).
806:
807: =head3 State=HostSet
808:
809: We have selected the domain name of our peer (multhomed hosts)
810: and are getting the reply (presumably ok) back.
811:
1.1 foxr 812: =head3 State=RequestingKey
1.3 albertel 813:
814: The ok has been received and we need to send the request for
1.1 foxr 815: an encryption key. Transition to writable for that.
1.3 albertel 816:
1.1 foxr 817: =head3 State=ReceivingKey
1.3 albertel 818:
819: The the key has been requested, now we are reading the new key.
820:
1.1 foxr 821: =head3 State=Idle
1.3 albertel 822:
823: The encryption key has been negotiated or we have finished
1.1 foxr 824: reading data from the a transaction. If the callback data has
825: a client as well as the socket iformation, then we are
826: doing a transaction and the data received is relayed to the client
827: before the socket is put on the idle list.
1.3 albertel 828:
1.1 foxr 829: =head3 State=SendingRequest
1.3 albertel 830:
831: I do not think this state can be received here, but if it is,
1.1 foxr 832: the appropriate thing to do is to transition to writable, and send
833: the request.
1.3 albertel 834:
1.1 foxr 835: =head3 State=ReceivingReply
1.3 albertel 836:
837: We finished sending the request to the server and now transition
1.1 foxr 838: to readable to receive the reply.
839:
840: The parameter to this function are:
1.3 albertel 841:
1.1 foxr 842: The event. Implicit in this is the watcher and its data. The data
843: contains at least the lond connection object and, if a
844: transaction is in progress, the socket attached to the local client.
845:
1.3 albertel 846: =cut
1.1 foxr 847:
848: sub LondReadable {
1.8 foxr 849:
1.41 albertel 850: my $Event = shift;
851: my $Watcher = $Event->w;
852: my $Socket = $Watcher->data;
853: my $client = undef;
1.40 foxr 854:
1.41 albertel 855: &Debug(6,"LondReadable called state = ".$Socket->GetState());
1.40 foxr 856:
857:
1.41 albertel 858: my $State = $Socket->GetState(); # All action depends on the state.
1.40 foxr 859:
1.41 albertel 860: SocketDump(6, $Socket);
861: my $status = $Socket->Readable();
1.40 foxr 862:
1.41 albertel 863: &Debug(2, "Socket->Readable returned: $status");
1.40 foxr 864:
1.41 albertel 865: if($status != 0) {
866: # bad return from socket read. Currently this means that
867: # The socket has become disconnected. We fail the transaction.
1.40 foxr 868:
1.41 albertel 869: Log("WARNING",
870: "Lond connection lost.");
871: if(exists($ActiveTransactions{$Socket})) {
872: FailTransaction($ActiveTransactions{$Socket});
1.56 foxr 873: } else {
874: # Socket is connecting and failed... need to mark
875: # no longer connecting.
876:
877: $LondConnecting = 0;
1.41 albertel 878: }
879: $Watcher->cancel();
880: KillSocket($Socket);
881: $ConnectionRetriesLeft--; # Counts as connection failure
882: return;
883: }
884: SocketDump(6,$Socket);
1.17 foxr 885:
1.41 albertel 886: $State = $Socket->GetState(); # Update in case of transition.
887: &Debug(6, "After read, state is ".$State);
1.1 foxr 888:
1.41 albertel 889: if($State eq "Initialized") {
1.1 foxr 890:
891:
1.41 albertel 892: } elsif ($State eq "ChallengeReceived") {
1.1 foxr 893: # The challenge must be echoed back; The state machine
894: # in the connection takes care of setting that up. Just
895: # need to transition to writable:
1.41 albertel 896:
897: $Watcher->cb(\&LondWritable);
898: $Watcher->poll("w");
1.1 foxr 899:
1.41 albertel 900: } elsif ($State eq "ChallengeReplied") {
1.1 foxr 901:
1.41 albertel 902: } elsif ($State eq "RequestingVersion") {
903: # Need to ask for the version... that is writiability:
1.1 foxr 904:
1.41 albertel 905: $Watcher->cb(\&LondWritable);
906: $Watcher->poll("w");
907:
908: } elsif ($State eq "ReadingVersionString") {
909: # Read the rest of the version string...
910: } elsif ($State eq "SetHost") {
911: # Need to request the actual domain get set...
912:
913: $Watcher->cb(\&LondWritable);
914: $Watcher->poll("w");
915: } elsif ($State eq "HostSet") {
916: # Reading the 'ok' from the peer.
917:
918: } elsif ($State eq "RequestingKey") {
1.1 foxr 919: # The ok was received. Now we need to request the key
920: # That requires us to be writable:
921:
1.41 albertel 922: $Watcher->cb(\&LondWritable);
923: $Watcher->poll("w");
1.1 foxr 924:
1.41 albertel 925: } elsif ($State eq "ReceivingKey") {
1.1 foxr 926:
1.41 albertel 927: } elsif ($State eq "Idle") {
1.40 foxr 928:
1.41 albertel 929: # This is as good a spot as any to get the peer version
930: # string:
1.40 foxr 931:
1.41 albertel 932: if($LondVersion eq "unknown") {
933: $LondVersion = $Socket->PeerVersion();
934: Log("INFO", "Connected to lond version: $LondVersion");
935: }
1.1 foxr 936: # If necessary, complete a transaction and then go into the
937: # idle queue.
1.22 foxr 938: # Note that a trasition to idle indicates a live lond
939: # on the other end so reset the connection retries.
940: #
1.41 albertel 941: $ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
942: $Watcher->cancel();
943: if(exists($ActiveTransactions{$Socket})) {
944: Debug(5,"Completing transaction!!");
945: CompleteTransaction($Socket,
946: $ActiveTransactions{$Socket});
947: } else {
948: Log("SUCCESS", "Connection ".$ConnectionCount." to "
949: .$RemoteHost." now ready for action");
950: }
951: ServerToIdle($Socket); # Next work unit or idle.
1.54 foxr 952:
953: #
954: $LondConnecting = 0; # Best spot I can think of for this.
955: #
1.6 foxr 956:
1.41 albertel 957: } elsif ($State eq "SendingRequest") {
1.1 foxr 958: # We need to be writable for this and probably don't belong
959: # here inthe first place.
960:
1.73 albertel 961: Debug(6, "SendingRequest state encountered in readable");
1.41 albertel 962: $Watcher->poll("w");
963: $Watcher->cb(\&LondWritable);
1.1 foxr 964:
1.41 albertel 965: } elsif ($State eq "ReceivingReply") {
1.1 foxr 966:
967:
1.41 albertel 968: } else {
969: # Invalid state.
970: Debug(4, "Invalid state in LondReadable");
971: }
1.1 foxr 972: }
1.3 albertel 973:
1.1 foxr 974: =pod
1.3 albertel 975:
1.1 foxr 976: =head2 LondWritable
1.3 albertel 977:
1.1 foxr 978: This function is called whenever a lond connection
979: becomes writable while there is a writeable monitoring
980: event. The action taken is very state dependent:
1.3 albertel 981:
1.1 foxr 982: =head3 State = Connected
1.3 albertel 983:
984: The connection is in the process of sending the 'init' hailing to the
985: lond on the remote end. The connection object''s Writable member is
986: called. On error, ConnectionError is called to destroy the connection
987: and remove it from the ActiveConnections hash
988:
1.1 foxr 989: =head3 Initialized
1.3 albertel 990:
991: 'init' has been sent, writability monitoring is removed and
992: readability monitoring is started with LondReadable as the callback.
993:
1.1 foxr 994: =head3 ChallengeReceived
1.3 albertel 995:
996: The connection has received the who are you challenge from the remote
997: system, and is in the process of sending the challenge
998: response. Writable is called.
999:
1.1 foxr 1000: =head3 ChallengeReplied
1.3 albertel 1001:
1002: The connection has replied to the initial challenge The we switch to
1003: monitoring readability looking for the server to reply with 'ok'.
1004:
1.1 foxr 1005: =head3 RequestingKey
1.3 albertel 1006:
1007: The connection is in the process of requesting its encryption key.
1008: Writable is called.
1009:
1.1 foxr 1010: =head3 ReceivingKey
1.3 albertel 1011:
1012: The connection has sent the request for a key. Switch to readability
1013: monitoring to accept the key
1014:
1.1 foxr 1015: =head3 SendingRequest
1.3 albertel 1016:
1017: The connection is in the process of sending a request to the server.
1018: This request is part of a client transaction. All the states until
1019: now represent the client setup protocol. Writable is called.
1020:
1.1 foxr 1021: =head3 ReceivingReply
1022:
1.3 albertel 1023: The connection has sent a request. Now it must receive a reply.
1024: Readability monitoring is requested.
1025:
1026: This function is an event handler and therefore receives as
1.1 foxr 1027: a parameter the event that has fired. The data for the watcher
1028: of this event is a reference to a list of one or two elements,
1029: depending on state. The first (and possibly only) element is the
1030: socket. The second (present only if a request is in progress)
1031: is the socket on which to return a reply to the caller.
1032:
1033: =cut
1.3 albertel 1034:
1.1 foxr 1035: sub LondWritable {
1036: my $Event = shift;
1037: my $Watcher = $Event->w;
1.8 foxr 1038: my $Socket = $Watcher->data;
1039: my $State = $Socket->GetState();
1.1 foxr 1040:
1.8 foxr 1041: Debug(6,"LondWritable State = ".$State."\n");
1.1 foxr 1042:
1.8 foxr 1043:
1.1 foxr 1044: # Figure out what to do depending on the state of the socket:
1045:
1046:
1047:
1048:
1049: SocketDump(6,$Socket);
1050:
1.42 foxr 1051: # If the socket is writable, we must always write.
1052: # Only by writing will we undergo state transitions.
1053: # Old logic wrote in state specific code below, however
1054: # That forces us at least through another invocation of
1055: # this function after writability is possible again.
1056: # This logic also factors out common code for handling
1057: # write failures... in all cases, write failures
1058: # Kill the socket.
1059: # This logic makes the branches of the >big< if below
1060: # so that the writing states are actually NO-OPs.
1061:
1062: if ($Socket->Writable() != 0) {
1.43 albertel 1063: # The write resulted in an error.
1064: # We'll treat this as if the socket got disconnected:
1065: Log("WARNING", "Connection to ".$RemoteHost.
1066: " has been disconnected");
1067: if(exists($ActiveTransactions{$Socket})) {
1068: FailTransaction($ActiveTransactions{$Socket});
1.56 foxr 1069: } else {
1070: # In the process of conneting, so need to turn that off.
1071:
1072: $LondConnecting = 0;
1.43 albertel 1073: }
1074: $Watcher->cancel();
1075: KillSocket($Socket);
1076: return;
1.42 foxr 1077: }
1078:
1079:
1080:
1.41 albertel 1081: if ($State eq "Connected") {
1.1 foxr 1082:
1.41 albertel 1083: # "init" is being sent...
1.42 foxr 1084:
1.41 albertel 1085: } elsif ($State eq "Initialized") {
1.4 foxr 1086:
1.41 albertel 1087: # Now that init was sent, we switch
1088: # to watching for readability:
1.1 foxr 1089:
1.41 albertel 1090: $Watcher->cb(\&LondReadable);
1091: $Watcher->poll("r");
1092:
1093: } elsif ($State eq "ChallengeReceived") {
1094: # We received the challenge, now we
1095: # are echoing it back. This is a no-op,
1096: # we're waiting for the state to change
1.1 foxr 1097:
1.41 albertel 1098: } elsif ($State eq "ChallengeReplied") {
1099: # The echo was sent back, so we switch
1100: # to watching readability.
1101:
1102: $Watcher->cb(\&LondReadable);
1103: $Watcher->poll("r");
1104: } elsif ($State eq "RequestingVersion") {
1105: # Sending the peer a version request...
1.42 foxr 1106:
1.41 albertel 1107: } elsif ($State eq "ReadingVersionString") {
1108: # Transition to read since we have sent the
1109: # version command and now just need to read the
1110: # version string from the peer:
1.40 foxr 1111:
1.41 albertel 1112: $Watcher->cb(\&LondReadable);
1113: $Watcher->poll("r");
1.40 foxr 1114:
1.41 albertel 1115: } elsif ($State eq "SetHost") {
1116: # Setting the remote domain...
1.42 foxr 1117:
1.41 albertel 1118: } elsif ($State eq "HostSet") {
1119: # Back to readable to get the ok.
1.40 foxr 1120:
1.41 albertel 1121: $Watcher->cb(\&LondReadable);
1122: $Watcher->poll("r");
1.40 foxr 1123:
1124:
1.41 albertel 1125: } elsif ($State eq "RequestingKey") {
1126: # At this time we're requesting the key.
1127: # again, this is essentially a no-op.
1128:
1129: } elsif ($State eq "ReceivingKey") {
1130: # Now we need to wait for the key
1131: # to come back from the peer:
1132:
1133: $Watcher->cb(\&LondReadable);
1134: $Watcher->poll("r");
1135:
1136: } elsif ($State eq "SendingRequest") {
1.40 foxr 1137:
1.41 albertel 1138: # At this time we are sending a request to the
1.1 foxr 1139: # peer... write the next chunk:
1140:
1.41 albertel 1141:
1142: } elsif ($State eq "ReceivingReply") {
1143: # The send has completed. Wait for the
1144: # data to come in for a reply.
1145: Debug(8,"Writable sent request/receiving reply");
1146: $Watcher->cb(\&LondReadable);
1147: $Watcher->poll("r");
1.1 foxr 1148:
1.41 albertel 1149: } else {
1150: # Control only passes here on an error:
1151: # the socket state does not match any
1152: # of the known states... so an error
1153: # must be logged.
1.1 foxr 1154:
1.41 albertel 1155: &Debug(4, "Invalid socket state ".$State."\n");
1156: }
1.1 foxr 1157:
1158: }
1.81 albertel 1159:
1.6 foxr 1160: =pod
1161:
1162: =cut
1.69 matthew 1163:
1.81 albertel 1164:
1.6 foxr 1165: sub QueueDelayed {
1.8 foxr 1166: Debug(3,"QueueDelayed called");
1167:
1.6 foxr 1168: my $path = "$perlvar{'lonSockDir'}/delayed";
1.8 foxr 1169:
1170: Debug(4, "Delayed path: ".$path);
1.6 foxr 1171: opendir(DIRHANDLE, $path);
1.75 albertel 1172:
1.82 albertel 1173: my $host_id_re = '(?:'.join('|',map {quotemeta($_)} (@all_host_ids)).')';
1.75 albertel 1174: my @alldelayed = grep(/\.$host_id_re$/, readdir(DIRHANDLE));
1.6 foxr 1175: closedir(DIRHANDLE);
1.75 albertel 1176: foreach my $dfname (sort(@alldelayed)) {
1177: my $reqfile = "$path/$dfname";
1178: my ($host_id) = ($dfname =~ /\.([^.]*)$/);
1179: Debug(4, "queueing ".$reqfile." for $host_id");
1.6 foxr 1180: my $Handle = IO::File->new($reqfile);
1181: my $cmd = <$Handle>;
1.8 foxr 1182: chomp $cmd; # There may or may not be a newline...
1.12 foxr 1183: $cmd = $cmd."\n"; # now for sure there's exactly one newline.
1.75 albertel 1184: my $Transaction = LondTransaction->new("sethost:$host_id:$cmd");
1.7 foxr 1185: $Transaction->SetDeferred($reqfile);
1186: QueueTransaction($Transaction);
1.6 foxr 1187: }
1188:
1189: }
1.1 foxr 1190:
1191: =pod
1.3 albertel 1192:
1.1 foxr 1193: =head2 MakeLondConnection
1.3 albertel 1194:
1195: Create a new lond connection object, and start it towards its initial
1196: idleness. Once idle, it becomes elligible to receive transactions
1197: from the work queue. If the work queue is not empty when the
1198: connection is completed and becomes idle, it will dequeue an entry and
1199: start off on it.
1200:
1.1 foxr 1201: =cut
1.3 albertel 1202:
1.1 foxr 1203: sub MakeLondConnection {
1204: Debug(4,"MakeLondConnection to ".GetServerHost()." on port "
1205: .GetServerPort());
1206:
1207: my $Connection = LondConnection->new(&GetServerHost(),
1.81 albertel 1208: &GetServerPort(),
1209: &GetHostId());
1.1 foxr 1210:
1.90 ! foxr 1211: if($Connection eq undef) {
1.9 foxr 1212: Log("CRITICAL","Failed to make a connection with lond.");
1.10 foxr 1213: $ConnectionRetriesLeft--;
1214: return 0; # Failure.
1.5 foxr 1215: } else {
1.22 foxr 1216:
1.82 albertel 1217: $LondConnecting = 1; # Connection in progress.
1.5 foxr 1218: # The connection needs to have writability
1219: # monitored in order to send the init sequence
1220: # that starts the whole authentication/key
1221: # exchange underway.
1222: #
1223: my $Socket = $Connection->GetSocket();
1.30 foxr 1224: if($Socket eq undef) {
1.64 foxr 1225: &child_exit(-1, "did not get a socket from the connection");
1.5 foxr 1226: } else {
1227: &Debug(9,"MakeLondConnection got socket: ".$Socket);
1228: }
1.1 foxr 1229:
1.21 foxr 1230: $Connection->SetTimeoutCallback(\&SocketTimeout);
1231:
1.23 foxr 1232: my $event = Event->io(fd => $Socket,
1.5 foxr 1233: poll => 'w',
1234: cb => \&LondWritable,
1.8 foxr 1235: data => $Connection,
1.5 foxr 1236: desc => 'Connection to lond server');
1237: $ActiveConnections{$Connection} = $event;
1.52 foxr 1238: if ($ConnectionCount == 0) {
1239: &SetupTimer; # Need to handle timeouts with connections...
1240: }
1.5 foxr 1241: $ConnectionCount++;
1.8 foxr 1242: Debug(4, "Connection count = ".$ConnectionCount);
1.6 foxr 1243: if($ConnectionCount == 1) { # First Connection:
1244: QueueDelayed;
1245: }
1.9 foxr 1246: Log("SUCESS", "Created connection ".$ConnectionCount
1247: ." to host ".GetServerHost());
1.10 foxr 1248: return 1; # Return success.
1.1 foxr 1249: }
1250:
1251: }
1.3 albertel 1252:
1.1 foxr 1253: =pod
1.3 albertel 1254:
1.1 foxr 1255: =head2 StartRequest
1.3 albertel 1256:
1257: Starts a lond request going on a specified lond connection.
1258: parameters are:
1259:
1260: =item $Lond
1261:
1262: Connection to the lond that will send the transaction and receive the
1263: reply.
1264:
1265: =item $Client
1266:
1267: Connection to the client that is making this request We got the
1268: request from this socket, and when the request has been relayed to
1269: lond and we get a reply back from lond it will get sent to this
1270: socket.
1271:
1272: =item $Request
1273:
1274: The text of the request to send.
1275:
1.1 foxr 1276: =cut
1277:
1278: sub StartRequest {
1.47 foxr 1279:
1280: my ($Lond, $Request) = @_;
1.1 foxr 1281:
1.7 foxr 1282: Debug(6, "StartRequest: ".$Request->getRequest());
1.1 foxr 1283:
1284: my $Socket = $Lond->GetSocket();
1285:
1.7 foxr 1286: $Request->Activate($Lond);
1287: $ActiveTransactions{$Lond} = $Request;
1.1 foxr 1288:
1.7 foxr 1289: $Lond->InitiateTransaction($Request->getRequest());
1.23 foxr 1290: my $event = Event->io(fd => $Socket,
1.1 foxr 1291: poll => "w",
1292: cb => \&LondWritable,
1293: data => $Lond,
1294: desc => "lond transaction connection");
1295: $ActiveConnections{$Lond} = $event;
1296: Debug(8," Start Request made watcher data with ".$event->data."\n");
1297: }
1298:
1299: =pod
1.3 albertel 1300:
1.1 foxr 1301: =head2 QueueTransaction
1.3 albertel 1302:
1303: If there is an idle lond connection, it is put to work doing this
1304: transaction. Otherwise, the transaction is placed in the work queue.
1305: If placed in the work queue and the maximum number of connections has
1306: not yet been created, a new connection will be started. Our goal is
1307: to eventually have a sufficient number of connections that the work
1308: queue will typically be empty. parameters are:
1309:
1310: =item Socket
1311:
1312: open on the lonc client.
1313:
1314: =item Request
1315:
1316: data to send to the lond.
1.1 foxr 1317:
1318: =cut
1.3 albertel 1319:
1.1 foxr 1320: sub QueueTransaction {
1321:
1.7 foxr 1322: my $requestData = shift; # This is a LondTransaction.
1323: my $cmd = $requestData->getRequest();
1324:
1325: Debug(6,"QueueTransaction: ".$cmd);
1.1 foxr 1326:
1327: my $LondSocket = $IdleConnections->pop();
1328: if(!defined $LondSocket) { # Need to queue request.
1.29 foxr 1329: Debug(5,"Must queue...");
1.1 foxr 1330: $WorkQueue->enqueue($requestData);
1.56 foxr 1331: Debug(5, "Queue Transaction startnew $ConnectionCount $LondConnecting");
1332: if(($ConnectionCount < $MaxConnectionCount) && (! $LondConnecting)) {
1333:
1.22 foxr 1334: if($ConnectionRetriesLeft > 0) {
1.29 foxr 1335: Debug(5,"Starting additional lond connection");
1.56 foxr 1336: if(&MakeLondConnection() == 0) {
1.22 foxr 1337: EmptyQueue(); # Fail transactions, can't make connection.
1.42 foxr 1338: CloseAllLondConnections; # Should all be closed but...
1.22 foxr 1339: }
1340: } else {
1341: ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
1.56 foxr 1342: $LondConnecting = 0;
1.22 foxr 1343: EmptyQueue(); # It's worse than that ... he's dead Jim.
1.42 foxr 1344: CloseAllLondConnections; # Should all be closed but..
1.17 foxr 1345: }
1.1 foxr 1346: }
1347: } else { # Can start the request:
1348: Debug(8,"Can start...");
1.7 foxr 1349: StartRequest($LondSocket, $requestData);
1.1 foxr 1350: }
1351: }
1352:
1353: #-------------------------- Lonc UNIX socket handling ---------------------
1.3 albertel 1354:
1.1 foxr 1355: =pod
1.3 albertel 1356:
1.1 foxr 1357: =head2 ClientRequest
1.3 albertel 1358: Callback that is called when data can be read from the UNIX domain
1359: socket connecting us with an apache server process.
1.1 foxr 1360:
1361: =cut
1362:
1363: sub ClientRequest {
1364: Debug(6, "ClientRequest");
1365: my $event = shift;
1366: my $watcher = $event->w;
1367: my $socket = $watcher->fd;
1368: my $data = $watcher->data;
1369: my $thisread;
1370:
1371: Debug(9, " Watcher named: ".$watcher->desc);
1372:
1373: my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
1374: Debug(8, "rcv: data length = ".length($thisread)
1375: ." read =".$thisread);
1.29 foxr 1376: unless (defined $rv && length($thisread)) {
1.1 foxr 1377: # Likely eof on socket.
1378: Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
1379: close($socket);
1380: $watcher->cancel();
1381: delete($ActiveClients{$socket});
1.10 foxr 1382: return;
1.1 foxr 1383: }
1384: Debug(8,"Data: ".$data." this read: ".$thisread);
1385: $data = $data.$thisread; # Append new data.
1386: $watcher->data($data);
1.44 albertel 1387: if($data =~ /\n$/) { # Request entirely read.
1.87 albertel 1388: if ($data eq "close_connection_exit\n") {
1.9 foxr 1389: Log("CRITICAL",
1390: "Request Close Connection ... exiting");
1391: CloseAllLondConnections();
1392: exit;
1.87 albertel 1393: } elsif ($data eq "reset_retries\n") {
1394: Log("INFO", "Resetting Connection Retries.");
1395: $ConnectionRetriesLeft = $ConnectionRetries;
1396: &UpdateStatus();
1397: my $Transaction = LondTransaction->new($data);
1398: $Transaction->SetClient($socket);
1399: StartClientReply($Transaction, "ok\n");
1400: $watcher->cancel();
1401: return;
1.9 foxr 1402: }
1.1 foxr 1403: Debug(8, "Complete transaction received: ".$data);
1.87 albertel 1404: if ($LogTransactions) {
1.39 foxr 1405: Log("SUCCESS", "Transaction: '$data'"); # Transaction has \n.
1406: }
1.8 foxr 1407: my $Transaction = LondTransaction->new($data);
1.7 foxr 1408: $Transaction->SetClient($socket);
1409: QueueTransaction($Transaction);
1.1 foxr 1410: $watcher->cancel(); # Done looking for input data.
1411: }
1412:
1413: }
1414:
1.62 foxr 1415: #
1416: # Accept a connection request for a client (lonc child) and
1417: # start up an event watcher to keep an eye on input from that
1418: # Event. This can be called both from NewClient and from
1.80 albertel 1419: # ChildProcess.
1.62 foxr 1420: # Parameters:
1421: # $socket - The listener socket.
1422: # Returns:
1423: # NONE
1424: # Side Effects:
1425: # An event is made to watch the accepted connection.
1426: # Active clients hash is updated to reflect the new connection.
1427: # The client connection count is incremented.
1428: #
1429: sub accept_client {
1430: my ($socket) = @_;
1431:
1432: Debug(8, "Entering accept for lonc UNIX socket\n");
1433: my $connection = $socket->accept(); # Accept the client connection.
1434: Debug(8,"Connection request accepted from "
1435: .GetPeername($connection, AF_UNIX));
1436:
1437:
1438: my $description = sprintf("Connection to lonc client %d",
1439: $ClientConnection);
1440: Debug(9, "Creating event named: ".$description);
1441: Event->io(cb => \&ClientRequest,
1442: poll => 'r',
1443: desc => $description,
1444: data => "",
1445: fd => $connection);
1446: $ActiveClients{$connection} = $ClientConnection;
1447: $ClientConnection++;
1448: }
1.1 foxr 1449:
1450: =pod
1.3 albertel 1451:
1.1 foxr 1452: =head2 NewClient
1.3 albertel 1453:
1454: Callback that is called when a connection is received on the unix
1455: socket for a new client of lonc. The callback is parameterized by the
1456: event.. which is a-priori assumed to be an io event, and therefore has
1457: an fd member that is the Listener socket. We Accept the connection
1458: and register a new event on the readability of that socket:
1459:
1.1 foxr 1460: =cut
1.3 albertel 1461:
1.1 foxr 1462: sub NewClient {
1463: Debug(6, "NewClient");
1464: my $event = shift; # Get the event parameters.
1465: my $watcher = $event->w;
1466: my $socket = $watcher->fd; # Get the event' socket.
1467:
1.62 foxr 1468: &accept_client($socket);
1.1 foxr 1469: }
1.3 albertel 1470:
1471: =pod
1472:
1473: =head2 GetLoncSocketPath
1474:
1475: Returns the name of the UNIX socket on which to listen for client
1476: connections.
1.1 foxr 1477:
1.58 foxr 1478: =head2 Parameters:
1479:
1480: host (optional) - Name of the host socket to return.. defaults to
1481: the return from GetServerHost().
1482:
1.1 foxr 1483: =cut
1.3 albertel 1484:
1.1 foxr 1485: sub GetLoncSocketPath {
1.58 foxr 1486:
1487: my $host = GetServerHost(); # Default host.
1488: if (@_) {
1489: ($host) = @_; # Override if supplied.
1490: }
1491: return $UnixSocketDir."/".$host;
1.1 foxr 1492: }
1493:
1.3 albertel 1494: =pod
1495:
1496: =head2 GetServerHost
1497:
1498: Returns the host whose lond we talk with.
1499:
1.1 foxr 1500: =cut
1.3 albertel 1501:
1.7 foxr 1502: sub GetServerHost {
1.1 foxr 1503: return $RemoteHost; # Setup by the fork.
1504: }
1.3 albertel 1505:
1506: =pod
1507:
1.81 albertel 1508: =head2 GetServerId
1509:
1510: Returns the hostid whose lond we talk with.
1511:
1512: =cut
1513:
1514: sub GetHostId {
1515: return $RemoteHostId; # Setup by the fork.
1516: }
1517:
1518: =pod
1519:
1.3 albertel 1520: =head2 GetServerPort
1521:
1522: Returns the lond port number.
1523:
1.1 foxr 1524: =cut
1.3 albertel 1525:
1.7 foxr 1526: sub GetServerPort {
1.1 foxr 1527: return $perlvar{londPort};
1528: }
1.3 albertel 1529:
1530: =pod
1531:
1532: =head2 SetupLoncListener
1533:
1534: Setup a lonc listener event. The event is called when the socket
1535: becomes readable.. that corresponds to the receipt of a new
1536: connection. The event handler established will accept the connection
1537: (creating a communcations channel), that int turn will establish
1538: another event handler to subess requests.
1.1 foxr 1539:
1.58 foxr 1540: =head2 Parameters:
1541:
1542: host (optional) Name of the host to set up a unix socket to.
1543:
1.1 foxr 1544: =cut
1.3 albertel 1545:
1.1 foxr 1546: sub SetupLoncListener {
1.78 albertel 1547: my ($host,$SocketName) = @_;
1548: if (!$host) { $host = &GetServerHost(); }
1549: if (!$SocketName) { $SocketName = &GetLoncSocketPath($host); }
1.1 foxr 1550:
1.78 albertel 1551:
1552: unlink($SocketName);
1.58 foxr 1553:
1.1 foxr 1554: my $socket;
1.7 foxr 1555: unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,
1.55 albertel 1556: Listen => 250,
1.1 foxr 1557: Type => SOCK_STREAM)) {
1.64 foxr 1558: if($I_am_child) {
1559: &child_exit(-1, "Failed to create a lonc listener socket");
1560: } else {
1561: die "Failed to create a lonc listner socket";
1562: }
1.1 foxr 1563: }
1.59 foxr 1564: return $socket;
1.1 foxr 1565: }
1566:
1.39 foxr 1567: #
1568: # Toggle transaction logging.
1569: # Implicit inputs:
1570: # LogTransactions
1571: # Implicit Outputs:
1572: # LogTransactions
1573: sub ToggleTransactionLogging {
1574: print STDERR "Toggle transaction logging...\n";
1575: if(!$LogTransactions) {
1576: $LogTransactions = 1;
1577: } else {
1578: $LogTransactions = 0;
1579: }
1580:
1581:
1582: Log("SUCCESS", "Toggled transaction logging: $LogTransactions \n");
1583: }
1584:
1.14 foxr 1585: =pod
1586:
1587: =head2 ChildStatus
1588:
1589: Child USR1 signal handler to report the most recent status
1590: into the status file.
1591:
1.22 foxr 1592: We also use this to reset the retries count in order to allow the
1593: client to retry connections with a previously dead server.
1.69 matthew 1594:
1.14 foxr 1595: =cut
1.46 albertel 1596:
1.14 foxr 1597: sub ChildStatus {
1598: my $event = shift;
1599: my $watcher = $event->w;
1600:
1601: Debug(2, "Reporting child status because : ".$watcher->data);
1602: my $docdir = $perlvar{'lonDocRoot'};
1.67 albertel 1603:
1604: open(LOG,">>$docdir/lon-status/loncstatus.txt");
1605: flock(LOG,LOCK_EX);
1606: print LOG $$."\t".$RemoteHost."\t".$Status."\t".
1.14 foxr 1607: $RecentLogEntry."\n";
1.38 foxr 1608: #
1609: # Write out information about each of the connections:
1610: #
1.46 albertel 1611: if ($DebugLevel > 2) {
1.67 albertel 1612: print LOG "Active connection statuses: \n";
1.46 albertel 1613: my $i = 1;
1614: print STDERR "================================= Socket Status Dump:\n";
1615: foreach my $item (keys %ActiveConnections) {
1616: my $Socket = $ActiveConnections{$item}->data;
1617: my $state = $Socket->GetState();
1.67 albertel 1618: print LOG "Connection $i State: $state\n";
1.46 albertel 1619: print STDERR "---------------------- Connection $i \n";
1.48 foxr 1620: $Socket->Dump(-1); # Ensure it gets dumped..
1.46 albertel 1621: $i++;
1622: }
1.38 foxr 1623: }
1.67 albertel 1624: flock(LOG,LOCK_UN);
1625: close(LOG);
1.22 foxr 1626: $ConnectionRetriesLeft = $ConnectionRetries;
1.70 albertel 1627: UpdateStatus();
1.14 foxr 1628: }
1629:
1.1 foxr 1630: =pod
1.3 albertel 1631:
1.10 foxr 1632: =head2 SignalledToDeath
1633:
1634: Called in response to a signal that causes a chid process to die.
1635:
1636: =cut
1637:
1638:
1639: sub SignalledToDeath {
1.14 foxr 1640: my $event = shift;
1641: my $watcher= $event->w;
1642:
1643: Debug(2,"Signalled to death! via ".$watcher->data);
1.17 foxr 1644: my ($signal) = $watcher->data;
1.10 foxr 1645: chomp($signal);
1646: Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "
1647: ."died through "."\"$signal\"");
1.68 albertel 1648: #LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
1649: # ."\"$signal\"");
1.12 foxr 1650: exit 0;
1.10 foxr 1651:
1652: }
1.16 foxr 1653:
1.69 matthew 1654: =pod
1655:
1.16 foxr 1656: =head2 ToggleDebug
1657:
1658: This sub toggles trace debugging on and off.
1659:
1660: =cut
1661:
1662: sub ToggleDebug {
1663: my $Current = $DebugLevel;
1664: $DebugLevel = $NextDebugLevel;
1665: $NextDebugLevel = $Current;
1666:
1667: Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel");
1668:
1669: }
1670:
1.69 matthew 1671: =pod
1672:
1.1 foxr 1673: =head2 ChildProcess
1674:
1675: This sub implements a child process for a single lonc daemon.
1.61 foxr 1676: Optional parameter:
1677: $socket - if provided, this is a socket already open for listen
1678: on the client socket. Otherwise, a new listen is set up.
1.1 foxr 1679:
1680: =cut
1681:
1682: sub ChildProcess {
1.80 albertel 1683: # We've inherited all the
1.62 foxr 1684: # events of our parent and those have to be cancelled or else
1685: # all holy bloody chaos will result.. trust me, I already made
1686: # >that< mistake.
1687:
1688: my $host = GetServerHost();
1689: foreach my $listener (keys %parent_dispatchers) {
1690: my $watcher = $parent_dispatchers{$listener};
1691: my $s = $watcher->fd;
1692: if ($listener ne $host) { # Close everyone but me.
1693: Debug(5, "Closing listen socket for $listener");
1694: $s->close();
1695: }
1696: Debug(5, "Killing watcher for $listener");
1697:
1698: $watcher->cancel();
1.65 foxr 1699: delete($parent_dispatchers{$listener});
1.62 foxr 1700:
1701: }
1.65 foxr 1702:
1703: # kill off the parent's signal handlers too!
1704: #
1705:
1706: for my $handler (keys %parent_handlers) {
1707: my $watcher = $parent_handlers{$handler};
1708: $watcher->cancel();
1709: delete($parent_handlers{$handler});
1710: }
1711:
1.64 foxr 1712: $I_am_child = 1; # Seems like in spite of it all I may still getting
1713: # parent event dispatches.. flag I'm a child.
1.1 foxr 1714:
1715:
1.14 foxr 1716: #
1717: # Signals must be handled by the Event framework...
1.61 foxr 1718: #
1.14 foxr 1719:
1720: Event->signal(signal => "QUIT",
1721: cb => \&SignalledToDeath,
1722: data => "QUIT");
1723: Event->signal(signal => "HUP",
1724: cb => \&ChildStatus,
1725: data => "HUP");
1726: Event->signal(signal => "USR1",
1727: cb => \&ChildStatus,
1728: data => "USR1");
1.39 foxr 1729: Event->signal(signal => "USR2",
1730: cb => \&ToggleTransactionLogging);
1.16 foxr 1731: Event->signal(signal => "INT",
1732: cb => \&ToggleDebug,
1733: data => "INT");
1.1 foxr 1734:
1.62 foxr 1735: # Figure out if we got passed a socket or need to open one to listen for
1736: # client requests.
1737:
1.61 foxr 1738: my ($socket) = @_;
1739: if (!$socket) {
1740:
1741: $socket = SetupLoncListener();
1742: }
1.62 foxr 1743: # Establish an event to listen for client connection requests.
1744:
1745:
1.59 foxr 1746: Event->io(cb => \&NewClient,
1747: poll => 'r',
1748: desc => 'Lonc Listener Unix Socket',
1749: fd => $socket);
1.1 foxr 1750:
1.76 albertel 1751: $Event::DebugLevel = $DebugLevel;
1.1 foxr 1752:
1753: Debug(9, "Making initial lond connection for ".$RemoteHost);
1754:
1755: # Setup the initial server connection:
1756:
1.62 foxr 1757: # &MakeLondConnection(); // let first work request do it.
1.10 foxr 1758:
1.80 albertel 1759: # need to accept the connection since the event may not fire.
1.62 foxr 1760:
1.80 albertel 1761: &accept_client($socket);
1.5 foxr 1762:
1.1 foxr 1763: Debug(9,"Entering event loop");
1764: my $ret = Event::loop(); # Start the main event loop.
1765:
1766:
1.64 foxr 1767: &child_exit (-1,"Main event loop exited!!!");
1.1 foxr 1768: }
1769:
1770: # Create a new child for host passed in:
1771:
1772: sub CreateChild {
1.81 albertel 1773: my ($host, $hostid) = @_;
1.52 foxr 1774:
1.12 foxr 1775: my $sigset = POSIX::SigSet->new(SIGINT);
1776: sigprocmask(SIG_BLOCK, $sigset);
1.1 foxr 1777: $RemoteHost = $host;
1.9 foxr 1778: Log("CRITICAL", "Forking server for ".$host);
1.23 foxr 1779: my $pid = fork;
1.1 foxr 1780: if($pid) { # Parent
1.17 foxr 1781: $RemoteHost = "Parent";
1.83 albertel 1782: $ChildPid{$pid} = $host;
1.12 foxr 1783: sigprocmask(SIG_UNBLOCK, $sigset);
1.82 albertel 1784: undef(@all_host_ids);
1.1 foxr 1785: } else { # child.
1.81 albertel 1786: $RemoteHostId = $hostid;
1.5 foxr 1787: ShowStatus("Connected to ".$RemoteHost);
1.23 foxr 1788: $SIG{INT} = 'DEFAULT';
1.12 foxr 1789: sigprocmask(SIG_UNBLOCK, $sigset);
1.81 albertel 1790: &ChildProcess(); # Does not return.
1.1 foxr 1791: }
1.61 foxr 1792: }
1.1 foxr 1793:
1.61 foxr 1794: # parent_client_connection:
1795: # Event handler that processes client connections for the parent process.
1796: # This sub is called when the parent is listening on a socket and
1797: # a connection request arrives. We must:
1798: # Start a child process to accept the connection request.
1799: # Kill our listen on the socket.
1800: # Parameter:
1801: # event - The event object that was created to monitor this socket.
1802: # event->w->fd is the socket.
1803: # Returns:
1804: # NONE
1805: #
1806: sub parent_client_connection {
1.62 foxr 1807: if ($I_am_child) {
1808: # Should not get here, but seem to anyway:
1809: &Debug(5," Child caught parent client connection event!!");
1810: my ($event) = @_;
1811: my $watcher = $event->w;
1812: $watcher->cancel(); # Try to kill it off again!!
1813: } else {
1814: &Debug(9, "parent_client_connection");
1815: my ($event) = @_;
1816: my $watcher = $event->w;
1817: my $socket = $watcher->fd;
1.81 albertel 1818: my $connection = $socket->accept(); # Accept the client connection.
1819: Event->io(cb => \&get_remote_hostname,
1820: poll => 'r',
1821: data => "",
1822: fd => $connection);
1.77 albertel 1823: }
1824: }
1825:
1826: sub get_remote_hostname {
1.82 albertel 1827: my ($event) = @_;
1828: my $watcher = $event->w;
1829: my $socket = $watcher->fd;
1830:
1831: my $thisread;
1832: my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
1833: Debug(8, "rcv: data length = ".length($thisread)." read =".$thisread);
1834: if (!defined($rv) || length($thisread) == 0) {
1835: # Likely eof on socket.
1836: Debug(5,"Client Socket closed on lonc for p_c_c");
1837: close($socket);
1838: $watcher->cancel();
1839: return;
1840: }
1841:
1842: my $data = $watcher->data().$thisread;
1843: $watcher->data($data);
1844: if($data =~ /\n$/) { # Request entirely read.
1845: chomp($data);
1846: } else {
1847: return;
1848: }
1.77 albertel 1849:
1.82 albertel 1850: &Debug(5,"Creating child for $data (parent_client_connection)");
1851: (my $hostname,my $lonid,@all_host_ids) = split(':',$data);
1.83 albertel 1852: $ChildHost{$hostname}++;
1853: if ($ChildHost{$hostname} == 1) {
1854: &CreateChild($hostname,$lonid);
1855: } else {
1856: &Log('WARNING',"Request for a second child on $hostname");
1857: }
1.82 albertel 1858: # Clean up the listen since now the child takes over until it exits.
1859: $watcher->cancel(); # Nolonger listening to this event
1860: $socket->send("done\n");
1861: $socket->close();
1.61 foxr 1862: }
1863:
1864: # parent_listen:
1865: # Opens a socket and starts a listen for the parent process on a client UNIX
1866: # domain socket.
1867: #
1868: # This involves:
1869: # Creating a socket for listen.
1870: # Removing any socket lock file
1871: # Adding an event handler for this socket becoming readable
1872: # To the parent's event dispatcher.
1873: # Parameters:
1874: # loncapa_host - LonCAPA cluster name of the host represented by the client
1875: # socket.
1876: # Returns:
1877: # NONE
1878: #
1879: sub parent_listen {
1880: my ($loncapa_host) = @_;
1881: Debug(5, "parent_listen: $loncapa_host");
1882:
1.78 albertel 1883: my ($socket,$file);
1884: if (!$loncapa_host) {
1885: $loncapa_host = 'common_parent';
1886: $file = $perlvar{'lonSockCreate'};
1887: } else {
1888: $file = &GetLoncSocketPath($loncapa_host);
1889: }
1890: $socket = &SetupLoncListener($loncapa_host,$file);
1891:
1.62 foxr 1892: $listening_to{$socket} = $loncapa_host;
1.61 foxr 1893: if (!$socket) {
1894: die "Unable to create a listen socket for $loncapa_host";
1895: }
1896:
1.78 albertel 1897: my $lock_file = $file.".lock";
1.61 foxr 1898: unlink($lock_file); # No problem if it doesn't exist yet [startup e.g.]
1899:
1.77 albertel 1900: my $watcher =
1901: Event->io(cb => \&parent_client_connection,
1902: poll => 'r',
1903: desc => "Parent listener unix socket ($loncapa_host)",
1904: data => "",
1905: fd => $socket);
1.62 foxr 1906: $parent_dispatchers{$loncapa_host} = $watcher;
1.61 foxr 1907:
1908: }
1909:
1.77 albertel 1910: sub parent_clean_up {
1911: my ($loncapa_host) = @_;
1.87 albertel 1912: Debug(1, "parent_clean_up: $loncapa_host");
1.77 albertel 1913:
1914: my $socket_file = &GetLoncSocketPath($loncapa_host);
1915: unlink($socket_file); # No problem if it doesn't exist yet [startup e.g.]
1916: my $lock_file = $socket_file.".lock";
1917: unlink($lock_file); # No problem if it doesn't exist yet [startup e.g.]
1918: }
1919:
1.61 foxr 1920:
1.83 albertel 1921:
1922: # This sub initiates a listen on the common unix domain lonc client socket.
1923: # loncnew starts up with no children, and only spawns off children when a
1924: # connection request occurs on the common client unix socket. The spawned
1925: # child continues to run until it has been idle a while at which point it
1926: # eventually exits and once more the parent picks up the listen.
1.61 foxr 1927: #
1928: # Parameters:
1929: # NONE
1930: # Implicit Inputs:
1931: # The configuration file that has been read in by LondConnection.
1932: # Returns:
1933: # NONE
1934: #
1.77 albertel 1935: sub listen_on_common_socket {
1936: Debug(5, "listen_on_common_socket");
1.78 albertel 1937: &parent_listen();
1.77 albertel 1938: }
1939:
1.63 foxr 1940: # server_died is called whenever a child process exits.
1941: # Since this is dispatched via a signal, we must process all
1942: # dead children until there are no more left. The action
1943: # is to:
1944: # - Remove the child from the bookeeping hashes
1945: # - Re-establish a listen on the unix domain socket associated
1946: # with that host.
1947: # Parameters:
1948: # The event, but we don't actually care about it.
1949: sub server_died {
1950: &Debug(9, "server_died called...");
1951:
1952: while(1) { # Loop until waitpid nowait fails.
1953: my $pid = waitpid(-1, WNOHANG);
1954: if($pid <= 0) {
1955: return; # Nothing left to wait for.
1956: }
1957: # need the host to restart:
1958:
1.83 albertel 1959: my $host = $ChildPid{$pid};
1.63 foxr 1960: if($host) { # It's for real...
1961: &Debug(9, "Caught sigchild for $host");
1.83 albertel 1962: delete($ChildPid{$pid});
1963: delete($ChildHost{$host});
1.81 albertel 1964: &parent_clean_up($host);
1965:
1.63 foxr 1966: } else {
1967: &Debug(5, "Caught sigchild for pid not in hosts hash: $pid");
1968: }
1969: }
1970:
1971: }
1972:
1.1 foxr 1973: #
1974: # Parent process logic pass 1:
1975: # For each entry in the hosts table, we will
1976: # fork off an instance of ChildProcess to service the transactions
1977: # to that host. Each pid will be entered in a global hash
1978: # with the value of the key, the host.
1979: # The parent will then enter a loop to wait for process exits.
1980: # Each exit gets logged and the child gets restarted.
1981: #
1982:
1.5 foxr 1983: #
1984: # Fork and start in new session so hang-up isn't going to
1985: # happen without intent.
1986: #
1987:
1988:
1.6 foxr 1989:
1990:
1.8 foxr 1991:
1.6 foxr 1992:
1993: ShowStatus("Forming new session");
1994: my $childpid = fork;
1995: if ($childpid != 0) {
1996: sleep 4; # Give child a chacne to break to
1997: exit 0; # a new sesion.
1998: }
1.8 foxr 1999: #
2000: # Write my pid into the pid file so I can be located
2001: #
2002:
2003: ShowStatus("Parent writing pid file:");
1.23 foxr 2004: my $execdir = $perlvar{'lonDaemons'};
1.8 foxr 2005: open (PIDSAVE, ">$execdir/logs/lonc.pid");
2006: print PIDSAVE "$$\n";
2007: close(PIDSAVE);
1.6 foxr 2008:
1.17 foxr 2009:
2010:
1.6 foxr 2011: if (POSIX::setsid() < 0) {
2012: print "Could not create new session\n";
2013: exit -1;
2014: }
1.5 foxr 2015:
2016: ShowStatus("Forking node servers");
2017:
1.9 foxr 2018: Log("CRITICAL", "--------------- Starting children ---------------");
2019:
1.31 foxr 2020: LondConnection::ReadConfig; # Read standard config files.
1.1 foxr 2021:
1.80 albertel 2022: $RemoteHost = "[parent]";
1.81 albertel 2023: &listen_on_common_socket();
1.60 foxr 2024:
1.12 foxr 2025: $RemoteHost = "Parent Server";
1.1 foxr 2026:
2027: # Maintain the population:
1.5 foxr 2028:
2029: ShowStatus("Parent keeping the flock");
1.1 foxr 2030:
1.12 foxr 2031:
1.80 albertel 2032: # We need to setup a SIGChild event to handle the exit (natural or otherwise)
2033: # of the children.
1.61 foxr 2034:
1.80 albertel 2035: Event->signal(cb => \&server_died,
2036: desc => "Child exit handler",
2037: signal => "CHLD");
2038:
2039:
2040: # Set up all the other signals we set up.
2041:
2042: $parent_handlers{INT} = Event->signal(cb => \&Terminate,
2043: desc => "Parent INT handler",
2044: signal => "INT");
2045: $parent_handlers{TERM} = Event->signal(cb => \&Terminate,
2046: desc => "Parent TERM handler",
2047: signal => "TERM");
1.81 albertel 2048: $parent_handlers{HUP} = Event->signal(cb => \&KillThemAll,
2049: desc => "Parent HUP handler.",
2050: signal => "HUP");
1.80 albertel 2051: $parent_handlers{USR1} = Event->signal(cb => \&CheckKids,
2052: desc => "Parent USR1 handler",
2053: signal => "USR1");
2054: $parent_handlers{USR2} = Event->signal(cb => \&UpdateKids,
2055: desc => "Parent USR2 handler.",
2056: signal => "USR2");
2057:
2058: # Start procdesing events.
2059:
2060: $Event::DebugLevel = $DebugLevel;
2061: Debug(9, "Parent entering event loop");
2062: my $ret = Event::loop();
2063: die "Main Event loop exited: $ret";
1.14 foxr 2064:
2065: =pod
2066:
2067: =head1 CheckKids
2068:
2069: Since kids do not die as easily in this implementation
2070: as the previous one, there is no need to restart the
2071: dead ones (all dead kids get restarted when they die!!)
2072: The only thing this function does is to pass USR1 to the
2073: kids so that they report their status.
2074:
2075: =cut
2076:
2077: sub CheckKids {
2078: Debug(2, "Checking status of children");
2079: my $docdir = $perlvar{'lonDocRoot'};
2080: my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt");
2081: my $now=time;
2082: my $local=localtime($now);
2083: print $fh "LONC status $local - parent $$ \n\n";
1.65 foxr 2084: foreach my $host (keys %parent_dispatchers) {
2085: print $fh "LONC Parent process listening for $host\n";
2086: }
1.83 albertel 2087: foreach my $pid (keys %ChildPid) {
1.14 foxr 2088: Debug(2, "Sending USR1 -> $pid");
2089: kill 'USR1' => $pid; # Tell Child to report status.
2090: }
1.65 foxr 2091:
1.14 foxr 2092: }
1.24 foxr 2093:
2094: =pod
2095:
2096: =head1 UpdateKids
2097:
1.25 foxr 2098: parent's SIGUSR2 handler. This handler:
1.24 foxr 2099:
2100: =item
2101:
2102: Rereads the hosts file.
2103:
2104: =item
2105:
2106: Kills off (via sigint) children for hosts that have disappeared.
2107:
2108: =item
2109:
1.27 foxr 2110: QUITs children for hosts that already exist (this just forces a status display
1.24 foxr 2111: and resets the connection retry count for that host.
2112:
2113: =item
2114:
2115: Starts new children for hosts that have been added to the hosts.tab file since
2116: the start of the master program and maintains them.
2117:
2118: =cut
2119:
2120: sub UpdateKids {
1.27 foxr 2121:
1.25 foxr 2122: Log("INFO", "Updating connections via SIGUSR2");
1.27 foxr 2123:
1.65 foxr 2124: # I'm not sure what I was thinking in the first implementation.
2125: # someone will have to work hard to convince me the effect is any
2126: # different than Restart, especially now that we don't start up
2127: # per host servers automatically, may as well just restart.
2128: # The down side is transactions that are in flight will get timed out
2129: # (lost unless they are critical).
1.27 foxr 2130:
1.81 albertel 2131: &KillThemAll();
1.24 foxr 2132: }
2133:
1.14 foxr 2134:
1.13 foxr 2135: =pod
2136:
2137: =head1 Restart
2138:
2139: Signal handler for HUP... all children are killed and
2140: we self restart. This is an el-cheapo way to re read
2141: the config file.
2142:
2143: =cut
2144:
2145: sub Restart {
1.23 foxr 2146: &KillThemAll; # First kill all the children.
1.13 foxr 2147: Log("CRITICAL", "Restarting");
2148: my $execdir = $perlvar{'lonDaemons'};
2149: unlink("$execdir/logs/lonc.pid");
1.65 foxr 2150: exec("$executable");
1.10 foxr 2151: }
1.12 foxr 2152:
2153: =pod
2154:
2155: =head1 KillThemAll
2156:
2157: Signal handler that kills all children by sending them a
1.17 foxr 2158: SIGHUP. Responds to sigint and sigterm.
1.12 foxr 2159:
2160: =cut
2161:
1.10 foxr 2162: sub KillThemAll {
1.12 foxr 2163: Debug(2, "Kill them all!!");
1.85 albertel 2164:
2165: #local($SIG{CHLD}) = 'IGNORE';
2166: # Our children >will< die.
2167: # but we need to catch their death and cleanup after them in case this is
2168: # a restart set of kills
2169: my @allpids = keys(%ChildPid);
2170: foreach my $pid (@allpids) {
1.83 albertel 2171: my $serving = $ChildPid{$pid};
1.52 foxr 2172: ShowStatus("Nicely Killing lonc for $serving pid = $pid");
2173: Log("CRITICAL", "Nicely Killing lonc for $serving pid = $pid");
1.17 foxr 2174: kill 'QUIT' => $pid;
1.12 foxr 2175: }
1.85 albertel 2176: ShowStatus("Finished killing child processes off.");
1.1 foxr 2177: }
1.12 foxr 2178:
1.52 foxr 2179:
2180: #
2181: # Kill all children via KILL. Just in case the
2182: # first shot didn't get them.
2183:
2184: sub really_kill_them_all_dammit
2185: {
2186: Debug(2, "Kill them all Dammit");
2187: local($SIG{CHLD} = 'IGNORE'); # In case some purist reenabled them.
1.83 albertel 2188: foreach my $pid (keys %ChildPid) {
2189: my $serving = $ChildPid{$pid};
1.52 foxr 2190: &ShowStatus("Nastily killing lonc for $serving pid = $pid");
2191: Log("CRITICAL", "Nastily killing lonc for $serving pid = $pid");
2192: kill 'KILL' => $pid;
1.83 albertel 2193: delete($ChildPid{$pid});
1.52 foxr 2194: my $execdir = $perlvar{'lonDaemons'};
2195: unlink("$execdir/logs/lonc.pid");
2196: }
2197: }
1.69 matthew 2198:
1.14 foxr 2199: =pod
2200:
2201: =head1 Terminate
2202:
2203: Terminate the system.
2204:
2205: =cut
2206:
2207: sub Terminate {
1.52 foxr 2208: &Log("CRITICAL", "Asked to kill children.. first be nice...");
2209: &KillThemAll;
2210: #
2211: # By now they really should all be dead.. but just in case
2212: # send them all SIGKILL's after a bit of waiting:
2213:
2214: sleep(4);
2215: &Log("CRITICAL", "Now kill children nasty");
2216: &really_kill_them_all_dammit;
1.17 foxr 2217: Log("CRITICAL","Master process exiting");
2218: exit 0;
1.14 foxr 2219:
2220: }
1.81 albertel 2221:
2222: sub my_hostname {
2223: use Sys::Hostname;
2224: my $name = &hostname();
2225: &Debug(9,"Name is $name");
2226: return $name;
2227: }
2228:
1.12 foxr 2229: =pod
1.1 foxr 2230:
2231: =head1 Theory
1.3 albertel 2232:
2233: The event class is used to build this as a single process with an
2234: event driven model. The following events are handled:
1.1 foxr 2235:
2236: =item UNIX Socket connection Received
2237:
2238: =item Request data arrives on UNIX data transfer socket.
2239:
2240: =item lond connection becomes writable.
2241:
2242: =item timer fires at 1 second intervals.
2243:
2244: All sockets are run in non-blocking mode. Timeouts managed by the timer
2245: handler prevents hung connections.
2246:
2247: Key data structures:
2248:
1.3 albertel 2249: =item RequestQueue
2250:
2251: A queue of requests received from UNIX sockets that are
2252: waiting for a chance to be forwarded on a lond connection socket.
2253:
2254: =item ActiveConnections
2255:
2256: A hash of lond connections that have transactions in process that are
2257: available to be timed out.
2258:
2259: =item ActiveTransactions
2260:
2261: A hash indexed by lond connections that contain the client reply
2262: socket for each connection that has an active transaction on it.
2263:
2264: =item IdleConnections
2265:
2266: A hash of lond connections that have no work to do. These connections
2267: can be closed if they are idle for a long enough time.
1.1 foxr 2268:
2269: =cut
1.88 foxr 2270:
2271: =pod
2272:
2273: =head1 Log messages
2274:
2275: The following is a list of log messages that can appear in the
2276: lonc.log file. Each log file has a severity and a message.
2277:
2278: =over 2
2279:
2280: =item Warning A socket timeout was detected
2281:
2282: If there are pending transactions in the socket's queue,
2283: they are failed (saved if critical). If the connection
2284: retry count gets exceeded by this, the
2285: remote host is marked as dead.
2286: Called when timeouts occured during the connection and
2287: connection dialog with a remote host.
2288:
2289: =item Critical Host makred DEAD <hostname>
2290:
2291: The numer of retry counts for contacting a host was
2292: exceeded. The host is marked dead an no
2293: further attempts will be made by that child.
2294:
2295: =item Info lonc pipe client hung up on us
2296:
2297: Write to the client pipe indicated no data transferred
2298: Socket to remote host is shut down. Reply to the client
2299: is discarded. Note: This is commented out in &ClientWriteable
2300:
2301: =item Success Reply from lond: <data>
2302:
2303: Can be enabled for debugging by setting LogTransactions to nonzero.
2304: Indicates a successful transaction with lond, <data> is the data received
2305: from the remote lond.
2306:
2307: =item Success A delayed transaction was completed
2308:
2309: A transaction that must be reliable was executed and completed
2310: as lonc restarted. This is followed by a mesage of the form
2311:
2312: S: client-name : request
2313:
2314: =item WARNING Failing transaction <cmd>:<subcmd>
2315:
2316: Transaction failed on a socket, but the failure retry count for the remote
2317: node has not yet been exhausted (the node is not yet marked dead).
2318: cmd is the command, subcmd is the subcommand. This results from a con_lost
2319: when communicating with lond.
2320:
2321: =item WARNING Shutting down a socket
2322:
2323: Called when a socket is being closed to lond. This is emitted both when
2324: idle pruning is being done and when the socket has been disconnected by the remote.
2325:
2326: =item WARNING Lond connection lost.
2327:
2328: Called when a read from lond's socket failed indicating lond has closed the
2329: connection or died. This should be followed by one or more
2330:
2331: "WARNING Failing transaction..." msgs for each in-flight or queued transaction.
2332:
2333: =item INFO Connected to lond version: <version>
2334:
2335: When connection negotiation is complete, the lond version is requested and logged here.
2336:
2337: =item SUCCESS Connection n to host now ready for action
2338:
2339: Emitted when connection has been completed with lond. n is then number of
2340: concurrent connections and host, the host to which the connection has just
2341: been established.
2342:
2343: =item WARNING Connection to host has been disconnected
2344:
2345: Write to a lond resulted in failure status. Connection to lond is dropped.
2346:
2347: =item SUCCESS Created connection n to host host
2348:
2349: Initial connection request to host..(before negotiation).
2350:
2351: =item CRITICAL Request Close Connection ... exiting
2352:
2353: Client has sent "close_connection_exit" The loncnew server is exiting.
2354:
2355: =item INFO Resetting Connection Retries
2356:
2357: Client has sent "reset_retries" The lond connection retries are reset to zero for the
2358: corresponding lond.
2359:
2360: =item SUCCESS Transaction <data>
2361:
2362: Only emitted if the global variable $LogTransactions was set to true.
2363: A client has requested a lond transaction <data> is the contents of the request.
2364:
2365: =item SUCCESS Toggled transaction logging <LogTransactions>
2366:
2367: The state of the $LogTransactions global has been toggled, and its current value
2368: (after being toggled) is displayed. When non zero additional logging of transactions
2369: is enabled for debugging purposes. Transaction logging is toggled on receipt of a USR2
2370: signal.
2371:
2372: =item CRITICAL Abnormal exit. Child <pid> for <host> died thorugh signal.
2373:
2374: QUIT signal received. lonc child process is exiting.
2375:
2376: =item SUCCESS New debugging level for <RemoteHost> now <DebugLevel>
2377:
2378: Debugging toggled for the host loncnew is talking with.
2379: Currently debugging is a level based scheme with higher number
2380: conveying more information. The daemon starts out at
2381: DebugLevel 0 and can toggle back and forth between that and
2382: DebugLevel 2 These are controlled by
2383: the global variables $DebugLevel and $NextDebugLevel
2384: The debug level can go up to 9.
2385: SIGINT toggles the debug level. The higher the debug level the
2386: more debugging information is spewed. See the Debug
2387: sub in loncnew.
2388:
2389: =item CRITICAL Forking server for host
2390:
2391: A child is being created to service requests for the specified host.
2392:
2393:
2394: =item WARNING Request for a second child on hostname
2395:
2396: Somehow loncnew was asked to start a second child on a host that already had a child
2397: servicing it. This request is not honored, but themessage is emitted. This could happen
2398: due to a race condition. When a client attempts to contact loncnew for a new host, a child
2399: is forked off to handle the requests for that server. The parent then backs off the Unix
2400: domain socket leaving it for the child to service all requests. If in the time between
2401: creating the child, and backing off, a new connection request comes in to the unix domain
2402: socket, this could trigger (unlikely but remotely possible),.
2403:
2404: =item CRITICAL ------ Starting Children ----
2405:
2406: This message should probably be changed to "Entering event loop" as the loncnew only starts
2407: children as needed. This message is emitted as new events are established and
2408: the event processing loop is entered.
2409:
2410: =item INFO Updating connections via SIGUSR2
2411:
2412: SIGUSR2 received. The original code would kill all clients, re-read the host file,
2413: then restart children for each host. Now that childrean aree started on demand, this
2414: just kills all child processes and lets requests start them as needed again.
2415:
2416:
2417: =item CRITICAL Restarting
2418:
2419: SigHUP received. all the children are killed and the script exec's itself to start again.
2420:
2421: =item CRITICAL Nicely killing lonc for host pid = <pid>
2422:
2423: Attempting to kill the child that is serving the specified host (pid given) cleanly via
2424: SIGQUIT The child should handle that, clean up nicely and exit.
2425:
2426: =item CRITICAL Nastily killing lonc for host pid = <pid>
2427:
2428: The child specified did not die when requested via SIGQUIT. Therefore it is killed
2429: via SIGKILL.
2430:
2431: =item CRITICAL Asked to kill children.. first be nice..
2432:
2433: In the parent's INT handler. INT kills the child processes. This inidicate loncnew
2434: is about to attempt to kill all known children via SIGQUIT. This message should be followed
2435: by one "Nicely killing" message for each extant child.
2436:
2437: =item CRITICAL Now kill children nasty
2438:
2439: In the parent's INT handler. remaining children are about to be killed via
2440: SIGKILL. Should be followed by a Nastily killing... for each lonc child that
2441: refused to die.
2442:
2443: =item CRITICAL Master process exiting
2444:
2445: In the parent's INT handler. just prior to the exit 0 call.
2446:
2447: =back
2448:
2449: =cut
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