1: #!/usr/bin/perl
2:
3: # The LearningOnline Network
4: # lonc - LON TCP-Client Domain-Socket-Server
5: # provides persistent TCP connections to the other servers in the network
6: # through multiplexed domain sockets
7: #
8: # $Id: lonc,v 1.28 2002/02/19 22:51:13 www Exp $
9: #
10: # Copyright Michigan State University Board of Trustees
11: #
12: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
13: #
14: # LON-CAPA is free software; you can redistribute it and/or modify
15: # it under the terms of the GNU General Public License as published by
16: # the Free Software Foundation; either version 2 of the License, or
17: # (at your option) any later version.
18: #
19: # LON-CAPA is distributed in the hope that it will be useful,
20: # but WITHOUT ANY WARRANTY; without even the implied warranty of
21: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22: # GNU General Public License for more details.
23: #
24: # You should have received a copy of the GNU General Public License
25: # along with LON-CAPA; if not, write to the Free Software
26: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
27: #
28: # /home/httpd/html/adm/gpl.txt
29: #
30: # http://www.lon-capa.org/
31: #
32: # PID in subdir logs/lonc.pid
33: # kill kills
34: # HUP restarts
35: # USR1 tries to open connections again
36:
37: # 6/4/99,6/5,6/7,6/8,6/9,6/10,6/11,6/12,7/14,7/19,
38: # 10/8,10/9,10/15,11/18,12/22,
39: # 2/8,7/25 Gerd Kortemeyer
40: # 12/05 Scott Harrison
41: # 12/05 Gerd Kortemeyer
42: # YEAR=2001
43: # 01/10/01 Scott Harrison
44: # 03/14/01,03/15,06/12,11/26,11/27,11/28 Gerd Kortemeyer
45: # 12/20 Scott Harrison
46: # YEAR=2002
47: # 2/19/02
48: #
49: # based on nonforker from Perl Cookbook
50: # - server who multiplexes without forking
51:
52: use POSIX;
53: use IO::Socket;
54: use IO::Select;
55: use IO::File;
56: use Socket;
57: use Fcntl;
58: use Tie::RefHash;
59: use Crypt::IDEA;
60: use Net::Ping;
61: use LWP::UserAgent();
62:
63: my $status='';
64: my $lastlog='';
65:
66: # grabs exception and records it to log before exiting
67: sub catchexception {
68: my ($signal)=@_;
69: $SIG{'QUIT'}='DEFAULT';
70: $SIG{__DIE__}='DEFAULT';
71: &logthis("<font color=red>CRITICAL: "
72: ."ABNORMAL EXIT. Child $$ for server $wasserver died through "
73: ."\"$signal\" with this parameter->[$@]</font>");
74: die($@);
75: }
76:
77: $childmaxattempts=5;
78:
79: # -------------------------------------- Routines to see if other box available
80:
81: sub online {
82: my $host=shift;
83: my $p=Net::Ping->new("tcp",20);
84: my $online=$p->ping("$host");
85: $p->close();
86: undef ($p);
87: return $online;
88: }
89:
90: sub connected {
91: my ($local,$remote)=@_;
92: $local=~s/\W//g;
93: $remote=~s/\W//g;
94:
95: unless ($hostname{$local}) { return 'local_unknown'; }
96: unless ($hostname{$remote}) { return 'remote_unknown'; }
97:
98: unless (&online($hostname{$local})) { return 'local_offline'; }
99:
100: my $ua=new LWP::UserAgent;
101:
102: my $request=new HTTP::Request('GET',
103: "http://".$hostname{$local}.'/cgi-bin/ping.pl?'.$remote);
104:
105: my $response=$ua->request($request);
106:
107: unless ($response->is_success) { return 'local_error'; }
108:
109: my $reply=$response->content;
110: $reply=(split("\n",$reply))[0];
111: $reply=~s/\W//g;
112: if ($reply ne $remote) { return $reply; }
113: return 'ok';
114: }
115:
116:
117: # -------------------------------- Set signal handlers to record abnormal exits
118:
119: $SIG{QUIT}=\&catchexception;
120: $SIG{__DIE__}=\&catchexception;
121:
122: # ------------------------------------ Read httpd access.conf and get variables
123:
124: open (CONFIG,"/etc/httpd/conf/access.conf") || die "Can't read access.conf";
125:
126: while ($configline=<CONFIG>) {
127: if ($configline =~ /PerlSetVar/) {
128: my ($dummy,$varname,$varvalue)=split(/\s+/,$configline);
129: chomp($varvalue);
130: $perlvar{$varname}=$varvalue;
131: }
132: }
133: close(CONFIG);
134:
135: # ----------------------------- Make sure this process is running from user=www
136: my $wwwid=getpwnam('www');
137: if ($wwwid!=$<) {
138: $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
139: $subj="LON: $perlvar{'lonHostID'} User ID mismatch";
140: system("echo 'User ID mismatch. lonc must be run as user www.' |\
141: mailto $emailto -s '$subj' > /dev/null");
142: exit 1;
143: }
144:
145: # --------------------------------------------- Check if other instance running
146:
147: my $pidfile="$perlvar{'lonDaemons'}/logs/lonc.pid";
148:
149: if (-e $pidfile) {
150: my $lfh=IO::File->new("$pidfile");
151: my $pide=<$lfh>;
152: chomp($pide);
153: if (kill 0 => $pide) { die "already running"; }
154: }
155:
156: # ------------------------------------------------------------- Read hosts file
157:
158: open (CONFIG,"$perlvar{'lonTabDir'}/hosts.tab") || die "Can't read host file";
159:
160: while ($configline=<CONFIG>) {
161: my ($id,$domain,$role,$name,$ip)=split(/:/,$configline);
162: chomp($ip);
163: if ($ip) {
164: $hostip{$id}=$ip;
165: $hostname{$id}=$name;
166: }
167: }
168:
169: close(CONFIG);
170:
171: # -------------------------------------------------------- Routines for forking
172:
173: %children = (); # keys are current child process IDs,
174: # values are hosts
175: %childpid = (); # the other way around
176:
177: %childatt = (); # number of attempts to start server
178: # for ID
179:
180: sub REAPER { # takes care of dead children
181: $SIG{CHLD} = \&REAPER;
182: my $pid = wait;
183: my $wasserver=$children{$pid};
184: &logthis("<font color=red>CRITICAL: "
185: ."Child $pid for server $wasserver died ($childatt{$wasserver})</font>");
186: delete $children{$pid};
187: delete $childpid{$wasserver};
188: my $port = "$perlvar{'lonSockDir'}/$wasserver";
189: unlink($port);
190: }
191:
192: sub hangup {
193: foreach (keys %children) {
194: $wasserver=$children{$_};
195: &status("Closing $wasserver");
196: &logthis('Closing '.$wasserver.': '.&subreply('exit',$wasserver));
197: &status("Kill PID $_ for $wasserver");
198: kill ('INT',$_);
199: }
200: }
201:
202: sub HUNTSMAN { # signal handler for SIGINT
203: local($SIG{CHLD}) = 'IGNORE'; # we're going to kill our children
204: &hangup();
205: my $execdir=$perlvar{'lonDaemons'};
206: unlink("$execdir/logs/lonc.pid");
207: &logthis("<font color=red>CRITICAL: Shutting down</font>");
208: exit; # clean up with dignity
209: }
210:
211: sub HUPSMAN { # signal handler for SIGHUP
212: local($SIG{CHLD}) = 'IGNORE'; # we're going to kill our children
213: &hangup();
214: &logthis("<font color=red>CRITICAL: Restarting</font>");
215: unlink("$execdir/logs/lonc.pid");
216: my $execdir=$perlvar{'lonDaemons'};
217: exec("$execdir/lonc"); # here we go again
218: }
219:
220: sub checkchildren {
221: &initnewstatus();
222: &logstatus();
223: &logthis('Going to check on the children');
224: foreach (sort keys %children) {
225: sleep 1;
226: unless (kill 'USR1' => $_) {
227: &logthis ('Child '.$_.' is dead');
228: &logstatus($$.' is dead');
229: }
230: }
231: }
232:
233: sub USRMAN {
234: &logthis("USR1: Trying to establish connections again");
235: %childatt=();
236: &checkchildren();
237: }
238:
239: # -------------------------------------------------- Non-critical communication
240: sub subreply {
241: my ($cmd,$server)=@_;
242: my $answer='';
243: if ($server ne $perlvar{'lonHostID'}) {
244: my $peerfile="$perlvar{'lonSockDir'}/$server";
245: my $sclient=IO::Socket::UNIX->new(Peer =>"$peerfile",
246: Type => SOCK_STREAM,
247: Timeout => 10)
248: or return "con_lost";
249:
250:
251: $SIG{ALRM}=sub { die "timeout" };
252: $SIG{__DIE__}='DEFAULT';
253: eval {
254: alarm(10);
255: print $sclient "$cmd\n";
256: $answer=<$sclient>;
257: chomp($answer);
258: alarm(0);
259: };
260: if ((!$answer) || ($@=~/timeout/)) { $answer="con_lost"; }
261: $SIG{ALRM}='DEFAULT';
262: $SIG{__DIE__}=\&catchexception;
263: } else { $answer='self_reply'; }
264: return $answer;
265: }
266:
267: # --------------------------------------------------------------------- Logging
268:
269: sub logthis {
270: my $message=shift;
271: my $execdir=$perlvar{'lonDaemons'};
272: my $fh=IO::File->new(">>$execdir/logs/lonc.log");
273: my $now=time;
274: my $local=localtime($now);
275: $lastlog=$local.': '.$message;
276: print $fh "$local ($$): $message\n";
277: }
278:
279:
280: sub logperm {
281: my $message=shift;
282: my $execdir=$perlvar{'lonDaemons'};
283: my $now=time;
284: my $local=localtime($now);
285: my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
286: print $fh "$now:$message:$local\n";
287: }
288: # ------------------------------------------------------------------ Log status
289:
290: sub logstatus {
291: my $docdir=$perlvar{'lonDocRoot'};
292: my $fh=IO::File->new(">>$docdir/lon-status/loncstatus.txt");
293: print $fh $$."\t".$status."\t".$lastlog."\n";
294: }
295:
296: sub initnewstatus {
297: my $docdir=$perlvar{'lonDocRoot'};
298: my $fh=IO::File->new(">$docdir/lon-status/loncstatus.txt");
299: my $now=time;
300: my $local=localtime($now);
301: print $fh "LONC status $local - parent $$\n\n";
302: }
303:
304: # -------------------------------------------------------------- Status setting
305:
306: sub status {
307: my $what=shift;
308: my $now=time;
309: my $local=localtime($now);
310: $status=$local.': '.$what;
311: }
312:
313:
314: # ---------------------------------------------------- Fork once and dissociate
315:
316: $fpid=fork;
317: exit if $fpid;
318: die "Couldn't fork: $!" unless defined ($fpid);
319:
320: POSIX::setsid() or die "Can't start new session: $!";
321:
322: # ------------------------------------------------------- Write our PID on disk
323:
324: $execdir=$perlvar{'lonDaemons'};
325: open (PIDSAVE,">$execdir/logs/lonc.pid");
326: print PIDSAVE "$$\n";
327: close(PIDSAVE);
328: &logthis("<font color=red>CRITICAL: ---------- Starting ----------</font>");
329:
330: # ----------------------------- Ignore signals generated during initial startup
331: $SIG{HUP}=$SIG{USR1}='IGNORE';
332: # ------------------------------------------------------- Now we are on our own
333:
334: # Fork off our children, one for every server
335:
336: &status("Forking ...");
337:
338: foreach $thisserver (keys %hostip) {
339: if (&online($hostname{$thisserver})) {
340: make_new_child($thisserver);
341: }
342: }
343:
344: &logthis("Done starting initial servers");
345: # ----------------------------------------------------- Install signal handlers
346:
347: $SIG{CHLD} = \&REAPER;
348: $SIG{INT} = $SIG{TERM} = \&HUNTSMAN;
349: $SIG{HUP} = \&HUPSMAN;
350: $SIG{USR1} = \&USRMAN;
351:
352: # And maintain the population.
353: while (1) {
354: &status("Sleeping");
355: sleep; # wait for a signal (i.e., child's death)
356: # See who died and start new one
357: &status("Woke up");
358: foreach $thisserver (keys %hostip) {
359: if (!$childpid{$thisserver}) {
360: if (($childatt{$thisserver}<$childmaxattempts) &&
361: (&online($hostname{$thisserver}))) {
362: $childatt{$thisserver}++;
363: &logthis(
364: "<font color=yellow>INFO: Trying to reconnect for $thisserver "
365: ."($childatt{$thisserver} of $childmaxattempts attempts)</font>");
366: make_new_child($thisserver);
367: } else {
368: &logthis(
369: "<font color=yellow>INFO: Skipping $thisserver "
370: ."($childatt{$thisserver} of $childmaxattempts attempts)</font>");
371: }
372:
373: }
374: }
375: }
376:
377:
378: sub make_new_child {
379:
380: my $conserver=shift;
381: my $pid;
382: my $sigset;
383: &logthis("Attempting to start child for server $conserver");
384: # block signal for fork
385: $sigset = POSIX::SigSet->new(SIGINT);
386: sigprocmask(SIG_BLOCK, $sigset)
387: or die "Can't block SIGINT for fork: $!\n";
388:
389: die "fork: $!" unless defined ($pid = fork);
390:
391: if ($pid) {
392: # Parent records the child's birth and returns.
393: sigprocmask(SIG_UNBLOCK, $sigset)
394: or die "Can't unblock SIGINT for fork: $!\n";
395: $children{$pid} = $conserver;
396: $childpid{$conserver} = $pid;
397: return;
398: } else {
399: # Child can *not* return from this subroutine.
400: $SIG{INT} = 'DEFAULT'; # make SIGINT kill us as it did before
401: $SIG{USR1}= \&logstatus;
402:
403: # unblock signals
404: sigprocmask(SIG_UNBLOCK, $sigset)
405: or die "Can't unblock SIGINT for fork: $!\n";
406:
407: # ----------------------------- This is the modified main program of non-forker
408:
409: $port = "$perlvar{'lonSockDir'}/$conserver";
410:
411: unlink($port);
412:
413: # ---------------------------------------------------- Client to network server
414:
415: &status("Opening TCP: $conserver");
416:
417: unless (
418: $remotesock = IO::Socket::INET->new(PeerAddr => $hostip{$conserver},
419: PeerPort => $perlvar{'londPort'},
420: Proto => "tcp",
421: Type => SOCK_STREAM)
422: ) {
423: my $st=120+int(rand(240));
424: &logthis(
425: "<font color=blue>WARNING: Couldn't connect $conserver ($st secs): $@</font>");
426: sleep($st);
427: exit;
428: };
429: # ----------------------------------------------------------------- Init dialog
430:
431: &status("Init dialogue: $conserver");
432:
433: $SIG{ALRM}=sub { die "timeout" };
434: $SIG{__DIE__}='DEFAULT';
435: eval {
436: alarm(60);
437: print $remotesock "init\n";
438: $answer=<$remotesock>;
439: print $remotesock "$answer";
440: $answer=<$remotesock>;
441: chomp($answer);
442: alarm(0);
443: };
444: $SIG{ALRM}='DEFAULT';
445: $SIG{__DIE__}=\&catchexception;
446:
447: if ($@=~/timeout/) {
448: &logthis("Timed out during init: $conserver");
449: exit;
450: }
451:
452:
453: &logthis("Init reply for $conserver: >$answer<");
454: if ($answer ne 'ok') {
455: my $st=120+int(rand(240));
456: &logthis(
457: "<font color=blue>WARNING: Init failed $conserver ($st secs)</font>");
458: sleep($st);
459: exit;
460: }
461: sleep 5;
462: &status("Ponging $conserver");
463: print $remotesock "pong\n";
464: $answer=<$remotesock>;
465: chomp($answer);
466: &logthis("Pong reply for $conserver: >$answer<");
467: # ----------------------------------------------------------- Initialize cipher
468:
469: &status("Initialize cipher: $conserver");
470: print $remotesock "ekey\n";
471: my $buildkey=<$remotesock>;
472: my $key=$conserver.$perlvar{'lonHostID'};
473: $key=~tr/a-z/A-Z/;
474: $key=~tr/G-P/0-9/;
475: $key=~tr/Q-Z/0-9/;
476: $key=$key.$buildkey.$key.$buildkey.$key.$buildkey;
477: $key=substr($key,0,32);
478: my $cipherkey=pack("H32",$key);
479: if ($cipher=new IDEA $cipherkey) {
480: &logthis("Secure connection initialized: $conserver");
481: } else {
482: my $st=120+int(rand(240));
483: &logthis(
484: "<font color=blue>WARNING: ".
485: "Could not establish secure connection, $conserver ($st secs)!</font>");
486: sleep($st);
487: exit;
488: }
489:
490: # ----------------------------------------- We're online, send delayed messages
491: &status("Checking for delayed messages");
492: my @allbuffered;
493: my $path="$perlvar{'lonSockDir'}/delayed";
494: opendir(DIRHANDLE,$path);
495: @allbuffered=grep /\.$conserver$/, readdir DIRHANDLE;
496: closedir(DIRHANDLE);
497: my $dfname;
498: foreach (@allbuffered) {
499: &status("Sending delayed $conserver $_");
500: $dfname="$path/$_";
501: &logthis($dfname);
502: my $wcmd;
503: {
504: my $dfh=IO::File->new($dfname);
505: $cmd=<$dfh>;
506: }
507: chomp($cmd);
508: my $bcmd=$cmd;
509: if ($cmd =~ /^encrypt\:/) {
510: my $rcmd=$cmd;
511: $rcmd =~ s/^encrypt\://;
512: chomp($rcmd);
513: my $cmdlength=length($rcmd);
514: $rcmd.=" ";
515: my $encrequest='';
516: for (my $encidx=0;$encidx<=$cmdlength;$encidx+=8) {
517: $encrequest.=
518: unpack("H16",$cipher->encrypt(substr($rcmd,$encidx,8)));
519: }
520: $cmd="enc:$cmdlength:$encrequest\n";
521: }
522: $SIG{ALRM}=sub { die "timeout" };
523: $SIG{__DIE__}='DEFAULT';
524: eval {
525: alarm(60);
526: print $remotesock "$cmd\n";
527: $answer=<$remotesock>;
528: chomp($answer);
529: alarm(0);
530: };
531: $SIG{ALRM}='DEFAULT';
532: $SIG{__DIE__}=\&catchexception;
533:
534: if (($answer ne '') && ($@!~/timeout/)) {
535: unlink("$dfname");
536: &logthis("Delayed $cmd to $conserver: >$answer<");
537: &logperm("S:$conserver:$bcmd");
538: }
539: }
540:
541: # ------------------------------------------------------- Listen to UNIX socket
542: &status("Opening socket $conserver");
543: unless (
544: $server = IO::Socket::UNIX->new(Local => $port,
545: Type => SOCK_STREAM,
546: Listen => 10 )
547: ) {
548: my $st=120+int(rand(240));
549: &logthis(
550: "<font color=blue>WARNING: ".
551: "Can't make server socket $conserver ($st secs): $@</font>");
552: sleep($st);
553: exit;
554: };
555:
556: # -----------------------------------------------------------------------------
557:
558: &logthis("<font color=green>$conserver online</font>");
559:
560: # -----------------------------------------------------------------------------
561: # begin with empty buffers
562: %inbuffer = ();
563: %outbuffer = ();
564: %ready = ();
565:
566: tie %ready, 'Tie::RefHash';
567:
568: nonblock($server);
569: $select = IO::Select->new($server);
570:
571: # Main loop: check reads/accepts, check writes, check ready to process
572: while (1) {
573: my $client;
574: my $rv;
575: my $data;
576:
577: # check for new information on the connections we have
578:
579: # anything to read or accept?
580: foreach $client ($select->can_read(0.1)) {
581:
582: if ($client == $server) {
583: # accept a new connection
584: &status("Accept new connection: $conserver");
585: $client = $server->accept();
586: $select->add($client);
587: nonblock($client);
588: } else {
589: # read data
590: $data = '';
591: $rv = $client->recv($data, POSIX::BUFSIZ, 0);
592:
593: unless (defined($rv) && length $data) {
594: # This would be the end of file, so close the client
595: delete $inbuffer{$client};
596: delete $outbuffer{$client};
597: delete $ready{$client};
598:
599: &status("Idle $conserver");
600: $select->remove($client);
601: close $client;
602: next;
603: }
604:
605: $inbuffer{$client} .= $data;
606:
607: # test whether the data in the buffer or the data we
608: # just read means there is a complete request waiting
609: # to be fulfilled. If there is, set $ready{$client}
610: # to the requests waiting to be fulfilled.
611: while ($inbuffer{$client} =~ s/(.*\n)//) {
612: push( @{$ready{$client}}, $1 );
613: }
614: }
615: }
616:
617: # Any complete requests to process?
618: foreach $client (keys %ready) {
619: handle($client);
620: }
621:
622: # Buffers to flush?
623: foreach $client ($select->can_write(1)) {
624: # Skip this client if we have nothing to say
625: next unless exists $outbuffer{$client};
626:
627: $rv = $client->send($outbuffer{$client}, 0);
628: unless (defined $rv) {
629: # Whine, but move on.
630: &logthis("I was told I could write, but I can't.\n");
631: next;
632: }
633: $errno=$!;
634: if (($rv == length $outbuffer{$client}) ||
635: ($errno == POSIX::EWOULDBLOCK) || ($errno == 0)) {
636: substr($outbuffer{$client}, 0, $rv) = '';
637: delete $outbuffer{$client} unless length $outbuffer{$client};
638: } else {
639: # Couldn't write all the data, and it wasn't because
640: # it would have blocked. Shutdown and move on.
641:
642: &logthis("Dropping data with ".$errno.": ".
643: length($outbuffer{$client}).", $rv");
644:
645: delete $inbuffer{$client};
646: delete $outbuffer{$client};
647: delete $ready{$client};
648:
649: $select->remove($client);
650: close($client);
651: next;
652: }
653: }
654: }
655: }
656:
657: # ------------------------------------------------------- End of make_new_child
658:
659: # handle($socket) deals with all pending requests for $client
660: sub handle {
661: # requests are in $ready{$client}
662: # send output to $outbuffer{$client}
663: my $client = shift;
664: my $request;
665:
666: foreach $request (@{$ready{$client}}) {
667: # ============================================================= Process request
668: # $request is the text of the request
669: # put text of reply into $outbuffer{$client}
670: # -----------------------------------------------------------------------------
671: if ($request =~ /^encrypt\:/) {
672: my $cmd=$request;
673: $cmd =~ s/^encrypt\://;
674: chomp($cmd);
675: my $cmdlength=length($cmd);
676: $cmd.=" ";
677: my $encrequest='';
678: for (my $encidx=0;$encidx<=$cmdlength;$encidx+=8) {
679: $encrequest.=
680: unpack("H16",$cipher->encrypt(substr($cmd,$encidx,8)));
681: }
682: $request="enc:$cmdlength:$encrequest\n";
683: }
684: # --------------------------------------------------------------- Main exchange
685: $SIG{ALRM}=sub { die "timeout" };
686: $SIG{__DIE__}='DEFAULT';
687: eval {
688: alarm(300);
689: &status("Sending $conserver: $request");
690: print $remotesock "$request";
691: &status("Waiting for reply from $conserver: $request");
692: $answer=<$remotesock>;
693: &status("Received reply: $request");
694: alarm(0);
695: };
696: if ($@=~/timeout/) {
697: $answer='';
698: &logthis(
699: "<font color=red>CRITICAL: Timeout $conserver: $request</font>");
700: }
701: $SIG{ALRM}='DEFAULT';
702: $SIG{__DIE__}=\&catchexception;
703:
704:
705: if ($answer) {
706: if ($answer =~ /^enc/) {
707: my ($cmd,$cmdlength,$encinput)=split(/:/,$answer);
708: chomp($encinput);
709: $answer='';
710: for (my $encidx=0;$encidx<length($encinput);$encidx+=16) {
711: $answer.=$cipher->decrypt(
712: pack("H16",substr($encinput,$encidx,16))
713: );
714: }
715: $answer=substr($answer,0,$cmdlength);
716: $answer.="\n";
717: }
718: $outbuffer{$client} .= $answer;
719: } else {
720: $outbuffer{$client} .= "con_lost\n";
721: }
722:
723: # ===================================================== Done processing request
724: }
725: delete $ready{$client};
726: &status("Completed $conserver: $request");
727: # -------------------------------------------------------------- End non-forker
728: }
729: # ---------------------------------------------------------- End make_new_child
730: }
731:
732: # nonblock($socket) puts socket into nonblocking mode
733: sub nonblock {
734: my $socket = shift;
735: my $flags;
736:
737:
738: $flags = fcntl($socket, F_GETFL, 0)
739: or die "Can't get flags for socket: $!\n";
740: fcntl($socket, F_SETFL, $flags | O_NONBLOCK)
741: or die "Can't make socket nonblocking: $!\n";
742: }
743:
744: # ----------------------------------- POD (plain old documentation, CPAN style)
745:
746: =head1 NAME
747:
748: lonc - LON TCP-MySQL-Server Daemon for handling database requests.
749:
750: =head1 SYNOPSIS
751:
752: Should only be run as user=www. This is a command-line script which
753: is invoked by loncron.
754:
755: =head1 DESCRIPTION
756:
757: Provides persistent TCP connections to the other servers in the network
758: through multiplexed domain sockets
759:
760: PID in subdir logs/lonc.pid
761: kill kills
762: HUP restarts
763: USR1 tries to open connections again
764:
765: =head1 README
766:
767: Not yet written.
768:
769: =head1 PREREQUISITES
770:
771: POSIX
772: IO::Socket
773: IO::Select
774: IO::File
775: Socket
776: Fcntl
777: Tie::RefHash
778: Crypt::IDEA
779:
780: =head1 COREQUISITES
781:
782: =head1 OSNAMES
783:
784: linux
785:
786: =head1 SCRIPT CATEGORIES
787:
788: Server/Process
789:
790: =cut
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