Annotation of loncom/lonc, revision 1.6
1.1 albertel 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: # PID in subdir logs/lonc.pid
9: # kill kills
10: # HUP restarts
11: # USR1 tries to open connections again
12:
1.2 www 13: # 6/4/99,6/5,6/7,6/8,6/9,6/10,6/11,6/12,7/14,7/19,
1.5 www 14: # 10/8,10/9,10/15,11/18,12/22,
15: # 2/8 Gerd Kortemeyer
1.1 albertel 16: # based on nonforker from Perl Cookbook
17: # - server who multiplexes without forking
18:
19: use POSIX;
20: use IO::Socket;
21: use IO::Select;
22: use IO::File;
23: use Socket;
24: use Fcntl;
25: use Tie::RefHash;
26: use Crypt::IDEA;
27:
1.5 www 28: $childmaxattempts=10;
29:
1.1 albertel 30: # ------------------------------------ Read httpd access.conf and get variables
31:
32: open (CONFIG,"/etc/httpd/conf/access.conf") || die "Can't read access.conf";
33:
34: while ($configline=<CONFIG>) {
35: if ($configline =~ /PerlSetVar/) {
36: my ($dummy,$varname,$varvalue)=split(/\s+/,$configline);
1.4 www 37: chomp($varvalue);
1.1 albertel 38: $perlvar{$varname}=$varvalue;
39: }
40: }
41: close(CONFIG);
42:
43: # ------------------------------------------------------------- Read hosts file
44:
45: open (CONFIG,"$perlvar{'lonTabDir'}/hosts.tab") || die "Can't read host file";
46:
47: while ($configline=<CONFIG>) {
48: my ($id,$domain,$role,$name,$ip)=split(/:/,$configline);
49: chomp($ip);
50: $hostip{$id}=$ip;
51: }
52: close(CONFIG);
53:
54: # -------------------------------------------------------- Routines for forking
55:
56: %children = (); # keys are current child process IDs,
57: # values are hosts
58: %childpid = (); # the other way around
59:
60: %childatt = (); # number of attempts to start server
61: # for ID
62:
63: sub REAPER { # takes care of dead children
64: $SIG{CHLD} = \&REAPER;
65: my $pid = wait;
66: my $wasserver=$children{$pid};
1.6 ! www 67: &logthis("<font color=red>CRITICAL: "
! 68: ."Child $pid for server $wasserver died ($childatt{$wasserver})</font>");
1.1 albertel 69: delete $children{$pid};
70: delete $childpid{$wasserver};
71: my $port = "$perlvar{'lonSockDir'}/$wasserver";
72: unlink($port);
73: }
74:
75: sub HUNTSMAN { # signal handler for SIGINT
76: local($SIG{CHLD}) = 'IGNORE'; # we're going to kill our children
77: kill 'INT' => keys %children;
78: my $execdir=$perlvar{'lonDaemons'};
79: unlink("$execdir/logs/lonc.pid");
1.5 www 80: &logthis("<font color=red>CRITICAL: Shutting down</font>");
1.1 albertel 81: exit; # clean up with dignity
82: }
83:
84: sub HUPSMAN { # signal handler for SIGHUP
85: local($SIG{CHLD}) = 'IGNORE'; # we're going to kill our children
86: kill 'INT' => keys %children;
1.5 www 87: &logthis("<font color=red>CRITICAL: Restarting</font>");
1.1 albertel 88: my $execdir=$perlvar{'lonDaemons'};
89: exec("$execdir/lonc"); # here we go again
90: }
91:
92: sub USRMAN {
93: &logthis("USR1: Trying to establish connections again");
94: foreach $thisserver (keys %hostip) {
95: $answer=subreply("ping",$thisserver);
1.6 ! www 96: &logthis("USR1: Ping $thisserver "
! 97: ."(pid >$childpid{$thisserver}<, $childatt{thisserver} attempts): "
! 98: ." >$answer<");
1.1 albertel 99: }
1.6 ! www 100: %childatt=();
1.1 albertel 101: }
102:
103: # -------------------------------------------------- Non-critical communication
104: sub subreply {
105: my ($cmd,$server)=@_;
1.5 www 106: my $answer='';
1.1 albertel 107: if ($server ne $perlvar{'lonHostID'}) {
108: my $peerfile="$perlvar{'lonSockDir'}/$server";
109: my $sclient=IO::Socket::UNIX->new(Peer =>"$peerfile",
110: Type => SOCK_STREAM,
111: Timeout => 10)
112: or return "con_lost";
113: print $sclient "$cmd\n";
114: my $answer=<$sclient>;
115: chomp($answer);
116: if (!$answer) { $answer="con_lost"; }
117: } else { $answer='self_reply'; }
118: return $answer;
119: }
120:
121: # --------------------------------------------------------------------- Logging
122:
123: sub logthis {
124: my $message=shift;
125: my $execdir=$perlvar{'lonDaemons'};
126: my $fh=IO::File->new(">>$execdir/logs/lonc.log");
127: my $now=time;
128: my $local=localtime($now);
129: print $fh "$local ($$): $message\n";
130: }
131:
1.3 www 132:
133: sub logperm {
134: my $message=shift;
135: my $execdir=$perlvar{'lonDaemons'};
136: my $now=time;
137: my $local=localtime($now);
138: my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
139: print $fh "$now:$message:$local\n";
140: }
141:
1.1 albertel 142: # ---------------------------------------------------- Fork once and dissociate
143:
144: $fpid=fork;
145: exit if $fpid;
146: die "Couldn't fork: $!" unless defined ($fpid);
147:
148: POSIX::setsid() or die "Can't start new session: $!";
149:
150: # ------------------------------------------------------- Write our PID on disk
151:
152: $execdir=$perlvar{'lonDaemons'};
153: open (PIDSAVE,">$execdir/logs/lonc.pid");
154: print PIDSAVE "$$\n";
155: close(PIDSAVE);
1.5 www 156: &logthis("<font color=red>CRITICAL: ---------- Starting ----------</font>");
1.1 albertel 157:
158: # ----------------------------- Ignore signals generated during initial startup
159: $SIG{HUP}=$SIG{USR1}='IGNORE';
160: # ------------------------------------------------------- Now we are on our own
161:
162: # Fork off our children, one for every server
163:
164: foreach $thisserver (keys %hostip) {
165: make_new_child($thisserver);
166: }
167:
168: &logthis("Done starting initial servers");
169: # ----------------------------------------------------- Install signal handlers
170:
171: $SIG{CHLD} = \&REAPER;
172: $SIG{INT} = $SIG{TERM} = \&HUNTSMAN;
173: $SIG{HUP} = \&HUPSMAN;
174: $SIG{USR1} = \&USRMAN;
175:
176: # And maintain the population.
177: while (1) {
178: sleep; # wait for a signal (i.e., child's death)
179: # See who died and start new one
180: foreach $thisserver (keys %hostip) {
181: if (!$childpid{$thisserver}) {
1.6 ! www 182: if ($childatt{$thisserver}<=$childmaxattempts) {
! 183: $childatt{$thisserver}++;
1.5 www 184: &logthis(
185: "<font color=yellow>INFO: Trying to reconnect for $thisserver "
1.6 ! www 186: ."($childatt{$thisserver} of $childmaxattempts attempts)</font>");
1.1 albertel 187: make_new_child($thisserver);
188: }
189: }
190: }
191: }
192:
193:
194: sub make_new_child {
195:
196: my $conserver=shift;
197: my $pid;
198: my $sigset;
199: &logthis("Attempting to start child for server $conserver");
200: # block signal for fork
201: $sigset = POSIX::SigSet->new(SIGINT);
202: sigprocmask(SIG_BLOCK, $sigset)
203: or die "Can't block SIGINT for fork: $!\n";
204:
205: die "fork: $!" unless defined ($pid = fork);
206:
207: if ($pid) {
208: # Parent records the child's birth and returns.
209: sigprocmask(SIG_UNBLOCK, $sigset)
210: or die "Can't unblock SIGINT for fork: $!\n";
211: $children{$pid} = $conserver;
212: $childpid{$conserver} = $pid;
213: return;
214: } else {
215: # Child can *not* return from this subroutine.
216: $SIG{INT} = 'DEFAULT'; # make SIGINT kill us as it did before
217:
218: # unblock signals
219: sigprocmask(SIG_UNBLOCK, $sigset)
220: or die "Can't unblock SIGINT for fork: $!\n";
221:
222: # ----------------------------- This is the modified main program of non-forker
223:
224: $port = "$perlvar{'lonSockDir'}/$conserver";
225:
226: unlink($port);
227: # ---------------------------------------------------- Client to network server
228: unless (
229: $remotesock = IO::Socket::INET->new(PeerAddr => $hostip{$conserver},
230: PeerPort => $perlvar{'londPort'},
231: Proto => "tcp",
232: Type => SOCK_STREAM)
1.5 www 233: ) {
234: my $st=120+int(rand(240));
235: &logthis(
236: "<font color=blue>WARNING: Couldn't connect $conserver ($st secs): $@</font>");
237: sleep($st);
1.1 albertel 238: exit;
239: };
240: # --------------------------------------- Send a ping to make other end do USR1
1.2 www 241: print $remotesock "init\n";
242: $answer=<$remotesock>;
243: print $remotesock "$answer";
1.1 albertel 244: $answer=<$remotesock>;
245: chomp($answer);
1.2 www 246: &logthis("Init reply for $conserver: >$answer<");
1.1 albertel 247: sleep 5;
248: print $remotesock "pong\n";
249: $answer=<$remotesock>;
250: chomp($answer);
251: &logthis("Pong reply for $conserver: >$answer<");
252: # ----------------------------------------------------------- Initialize cipher
253:
254: print $remotesock "ekey\n";
255: my $buildkey=<$remotesock>;
256: my $key=$conserver.$perlvar{'lonHostID'};
257: $key=~tr/a-z/A-Z/;
258: $key=~tr/G-P/0-9/;
259: $key=~tr/Q-Z/0-9/;
260: $key=$key.$buildkey.$key.$buildkey.$key.$buildkey;
261: $key=substr($key,0,32);
262: my $cipherkey=pack("H32",$key);
263: if ($cipher=new IDEA $cipherkey) {
264: &logthis("Secure connection inititalized: $conserver");
265: } else {
1.5 www 266: my $st=120+int(rand(240));
267: &logthis(
268: "<font color=blue>WARNING: ".
269: "Could not establish secure connection, $conserver ($st secs)!</font>");
270: sleep($st);
271: exit;
1.1 albertel 272: }
273:
1.3 www 274: # ----------------------------------------- We're online, send delayed messages
275:
1.4 www 276: my @allbuffered;
1.3 www 277: my $path="$perlvar{'lonSockDir'}/delayed";
1.4 www 278: opendir(DIRHANDLE,$path);
279: @allbuffered=grep /\.$conserver$/, readdir DIRHANDLE;
280: closedir(DIRHANDLE);
1.3 www 281: my $dfname;
1.4 www 282: map {
283: $dfname="$path/$_";
284: &logthis($dfname);
1.3 www 285: my $wcmd;
286: {
287: my $dfh=IO::File->new($dfname);
1.4 www 288: $cmd=<$dfh>;
1.3 www 289: }
290: chomp($cmd);
291: my $bcmd=$cmd;
292: if ($cmd =~ /^encrypt\:/) {
293: my $rcmd=$cmd;
294: $rcmd =~ s/^encrypt\://;
295: chomp($rcmd);
296: my $cmdlength=length($rcmd);
297: $rcmd.=" ";
298: my $encrequest='';
299: for (my $encidx=0;$encidx<=$cmdlength;$encidx+=8) {
300: $encrequest.=
301: unpack("H16",$cipher->encrypt(substr($rcmd,$encidx,8)));
302: }
303: $cmd="enc:$cmdlength:$encrequest\n";
304: }
305:
306: print $remotesock "$cmd\n";
307: $answer=<$remotesock>;
308: chomp($answer);
309: if ($answer ne '') {
310: unlink("$dfname");
1.4 www 311: &logthis("Delayed $cmd to $conserver: >$answer<");
1.3 www 312: &logperm("S:$conserver:$bcmd");
313: }
1.4 www 314: } @allbuffered;
1.1 albertel 315:
316: # ------------------------------------------------------- Listen to UNIX socket
317: unless (
318: $server = IO::Socket::UNIX->new(Local => $port,
319: Type => SOCK_STREAM,
320: Listen => 10 )
1.5 www 321: ) {
322: my $st=120+int(rand(240));
323: &logthis(
324: "<font color=blue>WARNING: ".
325: "Can't make server socket $conserver ($st secs): $@</font>");
326: sleep($st);
1.1 albertel 327: exit;
328: };
329:
330: # -----------------------------------------------------------------------------
331:
1.5 www 332: &logthis("<font color=green>$conserver online</font>");
333:
334: # -----------------------------------------------------------------------------
1.1 albertel 335: # begin with empty buffers
336: %inbuffer = ();
337: %outbuffer = ();
338: %ready = ();
339:
340: tie %ready, 'Tie::RefHash';
341:
342: nonblock($server);
343: $select = IO::Select->new($server);
344:
345: # Main loop: check reads/accepts, check writes, check ready to process
346: while (1) {
347: my $client;
348: my $rv;
349: my $data;
350:
351: # check for new information on the connections we have
352:
353: # anything to read or accept?
354: foreach $client ($select->can_read(1)) {
355:
356: if ($client == $server) {
357: # accept a new connection
358:
359: $client = $server->accept();
360: $select->add($client);
361: nonblock($client);
362: } else {
363: # read data
364: $data = '';
365: $rv = $client->recv($data, POSIX::BUFSIZ, 0);
366:
367: unless (defined($rv) && length $data) {
368: # This would be the end of file, so close the client
369: delete $inbuffer{$client};
370: delete $outbuffer{$client};
371: delete $ready{$client};
372:
373: $select->remove($client);
374: close $client;
375: next;
376: }
377:
378: $inbuffer{$client} .= $data;
379:
380: # test whether the data in the buffer or the data we
381: # just read means there is a complete request waiting
382: # to be fulfilled. If there is, set $ready{$client}
383: # to the requests waiting to be fulfilled.
384: while ($inbuffer{$client} =~ s/(.*\n)//) {
385: push( @{$ready{$client}}, $1 );
386: }
387: }
388: }
389:
390: # Any complete requests to process?
391: foreach $client (keys %ready) {
392: handle($client);
393: }
394:
395: # Buffers to flush?
396: foreach $client ($select->can_write(1)) {
397: # Skip this client if we have nothing to say
398: next unless exists $outbuffer{$client};
399:
400: $rv = $client->send($outbuffer{$client}, 0);
401: unless (defined $rv) {
402: # Whine, but move on.
403: warn "I was told I could write, but I can't.\n";
404: next;
405: }
406: if (($rv == length $outbuffer{$client}) ||
407: ($! == POSIX::EWOULDBLOCK)) {
408: substr($outbuffer{$client}, 0, $rv) = '';
409: delete $outbuffer{$client} unless length $outbuffer{$client};
410: } else {
411: # Couldn't write all the data, and it wasn't because
412: # it would have blocked. Shutdown and move on.
413: delete $inbuffer{$client};
414: delete $outbuffer{$client};
415: delete $ready{$client};
416:
417: $select->remove($client);
418: close($client);
419: next;
420: }
421: }
422: }
423: }
424:
425: # ------------------------------------------------------- End of make_new_child
426:
427: # handle($socket) deals with all pending requests for $client
428: sub handle {
429: # requests are in $ready{$client}
430: # send output to $outbuffer{$client}
431: my $client = shift;
432: my $request;
433:
434: foreach $request (@{$ready{$client}}) {
435: # ============================================================= Process request
436: # $request is the text of the request
437: # put text of reply into $outbuffer{$client}
438: # -----------------------------------------------------------------------------
439: if ($request =~ /^encrypt\:/) {
440: my $cmd=$request;
441: $cmd =~ s/^encrypt\://;
442: chomp($cmd);
443: my $cmdlength=length($cmd);
444: $cmd.=" ";
445: my $encrequest='';
446: for (my $encidx=0;$encidx<=$cmdlength;$encidx+=8) {
447: $encrequest.=
448: unpack("H16",$cipher->encrypt(substr($cmd,$encidx,8)));
449: }
450: $request="enc:$cmdlength:$encrequest\n";
451: }
452: print $remotesock "$request";
453: $answer=<$remotesock>;
454: if ($answer) {
455: if ($answer =~ /^enc/) {
456: my ($cmd,$cmdlength,$encinput)=split(/:/,$answer);
457: chomp($encinput);
458: $answer='';
459: for (my $encidx=0;$encidx<length($encinput);$encidx+=16) {
460: $answer.=$cipher->decrypt(
461: pack("H16",substr($encinput,$encidx,16))
462: );
463: }
464: $answer=substr($answer,0,$cmdlength);
465: $answer.="\n";
466: }
467: $outbuffer{$client} .= $answer;
468: } else {
469: $outbuffer{$client} .= "con_lost\n";
470: }
471:
472: # ===================================================== Done processing request
473: }
474: delete $ready{$client};
475: # -------------------------------------------------------------- End non-forker
476: }
477: # ---------------------------------------------------------- End make_new_child
478: }
479:
480: # nonblock($socket) puts socket into nonblocking mode
481: sub nonblock {
482: my $socket = shift;
483: my $flags;
484:
485:
486: $flags = fcntl($socket, F_GETFL, 0)
487: or die "Can't get flags for socket: $!\n";
488: fcntl($socket, F_SETFL, $flags | O_NONBLOCK)
489: or die "Can't make socket nonblocking: $!\n";
490: }
491:
492:
493:
494:
495:
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/back.gif){kind=icon}
Return to lonc CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [LON-CAPA] / loncom