--- loncom/Attic/lonc 2002/03/20 03:42:45 1.33
+++ loncom/Attic/lonc 2003/07/02 01:28:12 1.50
@@ -5,7 +5,7 @@
# provides persistent TCP connections to the other servers in the network
# through multiplexed domain sockets
#
-# $Id: lonc,v 1.33 2002/03/20 03:42:45 foxr Exp $
+# $Id: lonc,v 1.50 2003/07/02 01:28:12 foxr Exp $
#
# Copyright Michigan State University Board of Trustees
#
@@ -37,18 +37,18 @@
# 6/4/99,6/5,6/7,6/8,6/9,6/10,6/11,6/12,7/14,7/19,
# 10/8,10/9,10/15,11/18,12/22,
# 2/8,7/25 Gerd Kortemeyer
-# 12/05 Scott Harrison
# 12/05 Gerd Kortemeyer
# YEAR=2001
-# 01/10/01 Scott Harrison
# 03/14/01,03/15,06/12,11/26,11/27,11/28 Gerd Kortemeyer
-# 12/20 Scott Harrison
# YEAR=2002
# 2/19/02,02/22/02,02/25/02 Gerd Kortemeyer
# 3/07/02 Ron Fox
# based on nonforker from Perl Cookbook
# - server who multiplexes without forking
+use lib '/home/httpd/lib/perl/';
+use LONCAPA::Configuration;
+
use POSIX;
use IO::Socket;
use IO::Select;
@@ -64,25 +64,19 @@ $status='';
$lastlog='';
$conserver='SHELL';
$DEBUG = 0; # Set to 1 for annoyingly complete logs.
-
+$VERSION='$Revison$'; #' stupid emacs
+$remoteVERSION;
# -------------------------------- Set signal handlers to record abnormal exits
&status("Init exception handlers");
$SIG{QUIT}=\&catchexception;
$SIG{__DIE__}=\&catchexception;
-# ------------------------------------ Read httpd access.conf and get variables
-&status("Read access.conf");
-open (CONFIG,"/etc/httpd/conf/access.conf") || die "Can't read access.conf";
-
-while ($configline=<CONFIG>) {
- if ($configline =~ /PerlSetVar/) {
- my ($dummy,$varname,$varvalue)=split(/\s+/,$configline);
- chomp($varvalue);
- $perlvar{$varname}=$varvalue;
- }
-}
-close(CONFIG);
+# ---------------------------------- Read loncapa_apache.conf and loncapa.conf
+&status("Read loncapa.conf and loncapa_apache.conf");
+my $perlvarref=LONCAPA::Configuration::read_conf('loncapa.conf');
+my %perlvar=%{$perlvarref};
+undef $perlvarref;
# ----------------------------- Make sure this process is running from user=www
&status("Check user ID");
@@ -175,7 +169,14 @@ $SIG{USR1} = \&USRMAN;
# And maintain the population.
while (1) {
my $deadpid = wait; # Wait for the next child to die.
- # See who died and start new one
+ # See who died and start new one
+ # or a signal (e.g. USR1 for restart).
+ # if a signal, the wait will fail
+ # This is ordinarily detected by
+ # checking for the existence of the
+ # pid index inthe children hash since
+ # the return value from a failed wait is -1
+ # which is an impossible PID.
&status("Woke up");
my $skipping='';
@@ -255,7 +256,7 @@ unlink($port);
@allbuffered=grep /\.$conserver$/, readdir DIRHANDLE;
closedir(DIRHANDLE);
my $dfname;
- foreach (@allbuffered) {
+ foreach (sort @allbuffered) {
&status("Sending delayed: $_");
$dfname="$path/$_";
if($DEBUG) { &logthis('Sending '.$dfname); }
@@ -314,114 +315,292 @@ unless (
%inbuffer = ();
%outbuffer = ();
%ready = ();
+%servers = (); # To be compatible with make filevector. indexed by
+ # File ids, values are sockets.
+ # note that the accept socket is omitted.
tie %ready, 'Tie::RefHash';
-nonblock($server);
-$select = IO::Select->new($server);
+# nonblock($server);
+# $select = IO::Select->new($server);
# Main loop: check reads/accepts, check writes, check ready to process
+
+status("Main loop $conserver");
while (1) {
my $client;
my $rv;
my $data;
- # check for new information on the connections we have
+ my $infdset; # bit vec of fd's to select on input.
- # anything to read or accept?
+ my $outfdset; # Bit vec of fd's to select on output.
- foreach $client ($select->can_read(100.0)) {
- if ($client == $server) {
- # accept a new connection
- &status("Accept new connection: $conserver");
- $client = $server->accept();
- $select->add($client);
- nonblock($client);
- } else {
- # read data
- $data = '';
- $rv = $client->recv($data, POSIX::BUFSIZ, 0);
-
- unless (defined($rv) && length $data) {
- # This would be the end of file, so close the client
- delete $inbuffer{$client};
- delete $outbuffer{$client};
- delete $ready{$client};
-
- &status("Idle");
- $select->remove($client);
- close $client;
- next;
- }
- $inbuffer{$client} .= $data;
+ $infdset = MakeFileVector(\%servers);
+ $outfdset= MakeFileVector(\%outbuffer);
+ vec($infdset, $server->fileno, 1) = 1;
+ if($DEBUG) {
+ &logthis("Adding ".$server->fileno.
+ " to input select vector (listner)".
+ unpack("b*",$infdset)."\n");
+ }
+ DoSelect(\$infdset, \$outfdset); # Wait for input.
+ if($DEBUG) {
+ &logthis("Doselect completed!");
+ &logthis("ins = ".unpack("b*",$infdset)."\n");
+ &logthis("outs= ".unpack("b*",$outfdset)."\n");
+
+ }
+ # Checkfor new connections:
+ if (vec($infdset, $server->fileno, 1)) {
+ if($DEBUG) {
+ &logthis("New connection established");
+ }
+ # accept a new connection
+ &status("Accept new connection: $conserver");
+ $client = $server->accept();
+ if($DEBUG) {
+ &logthis("New client fd = ".$client->fileno."\n");
+ }
+ $servers{$client->fileno} = $client;
+ nonblock($client);
+ $client->sockopt(SO_KEEPALIVE, 1);# Enable monitoring of
+ # connection liveness.
+ }
+ HandleInput($infdset, \%servers, \%inbuffer, \%outbuffer, \%ready);
+ HandleOutput($outfdset, \%servers, \%outbuffer, \%inbuffer,
+ \%ready);
+# -------------------------------------------------------- Wow, connection lost
- # test whether the data in the buffer or the data we
- # just read means there is a complete request waiting
- # to be fulfilled. If there is, set $ready{$client}
- # to the requests waiting to be fulfilled.
- while ($inbuffer{$client} =~ s/(.*\n)//) {
- push( @{$ready{$client}}, $1 );
- }
- }
+}
+
}
-
- # Any complete requests to process?
- foreach $client (keys %ready) {
- handle($client);
+}
+
+# ------------------------------------------------------- End of make_new_child
+
+
+#
+# Make a vector of file descriptors to wait for in a select.
+# parameters:
+# \%fdhash -reference to a hash which has IO::Socket's as indices.
+# We only care about the indices, not the values.
+# A select vector is created from all indices of the hash.
+
+sub MakeFileVector
+{
+ my $fdhash = shift;
+ my $selvar = "";
+
+ foreach $socket (keys %$fdhash) {
+ if($DEBUG) {
+ &logthis("Adding ".$socket.
+ "to select vector. (client)\n");
+ }
+ vec($selvar, $socket, 1) = 1;
}
-
- # Buffers to flush?
- foreach $client ($select->can_write(1)) {
- # Skip this client if we have nothing to say
- next unless exists $outbuffer{$client};
-
- $rv = $client->send($outbuffer{$client}, 0);
-
- unless ($outbuffer{$client} eq "con_lost\n") {
- unless (defined $rv) {
- # Whine, but move on.
- &logthis("I was told I could write, but I can't.\n");
- next;
- }
- $errno=$!;
- if (($rv == length $outbuffer{$client}) ||
- ($errno == POSIX::EWOULDBLOCK) || ($errno == 0)) {
- substr($outbuffer{$client}, 0, $rv) = '';
- delete $outbuffer{$client} unless length $outbuffer{$client};
- } else {
- # Couldn't write all the data, and it wasn't because
- # it would have blocked. Shutdown and move on.
+ return $selvar;
+}
- &logthis("Dropping data with ".$errno.": ".
- length($outbuffer{$client}).", $rv");
- delete $inbuffer{$client};
- delete $outbuffer{$client};
- delete $ready{$client};
-
- $select->remove($client);
- close($client);
- next;
- }
- } else {
-# -------------------------------------------------------- Wow, connection lost
- &logthis(
- "<font color=red>CRITICAL: Closing connection</font>");
- &status("Connection lost");
- $remotesock->shutdown(2);
- &logthis("Attempting to open new connection");
- &openremote($conserver);
- }
+#
+# HandleOutput:
+# Processes output on a buffered set of file descriptors which are
+# ready to be read.
+# Parameters:
+# $selvector - Vector of file descriptors which are writable.
+# \%sockets - Vector of socket references indexed by socket.
+# \%buffers - Reference to a hash containing output buffers.
+# Hashes are indexed by sockets. The file descriptors of some
+# of those sockets will be present in $selvector.
+# For each one of those, we will attempt to write the output
+# buffer to the socket. Note that we will assume that
+# the sockets are being run in non blocking mode.
+# \%inbufs - Reference to hash containing input buffers.
+# \%readys - Reference to hash containing flags for items with complete
+# requests.
+#
+sub HandleOutput
+{
+ my $selvector = shift;
+ my $sockets = shift;
+ my $buffers = shift;
+ my $inbufs = shift;
+ my $readys = shift;
+ my $sock;
+
+ if($DEBUG) {
+ &logthis("HandleOutput entered\n");
}
-
+
+ foreach $sock (keys %$sockets) {
+ my $socket = $sockets->{$sock};
+ if(vec($selvector, $sock, 1)) { # $socket is writable.
+ if($DEBUG) {
+ &logthis("Sending $buffers->{$sock} \n");
+ }
+ my $rv = $socket->send($buffers->{$sock}, 0);
+ $errno = $!;
+ unless ($buffers->{$sock} eq "con_lost\n") {
+ unless (defined $rv) { # Write failed... could be EINTR
+ unless ($errno == POSIX::EINTR) {
+ &logthis("Write failed on writable socket");
+ } # EINTR is not an error .. just retry.
+ next;
+ }
+ if( ($rv == length $buffers->{$sock}) ||
+ ($errno == POSIX::EWOULDBLOCK) ||
+ ($errno == POSIX::EAGAIN) || # same as above.
+ ($errno == POSIX::EINTR) || # signal during IO
+ ($errno == 0)) {
+ substr($buffers->{$sock}, 0, $rv)=""; # delete written part
+ delete $buffers->{$sock} unless length $buffers->{$sock};
+ } else {
+ # For some reason the write failed with an error code
+ # we didn't look for. Shutdown the socket.
+ &logthis("Unable to write data with ".$errno.": ".
+ "Dropping data: ".length($buffers->{$sock}).
+ ", $rv");
+ #
+ # kill off the buffers in the hash:
+
+ delete $buffers->{$sock};
+ delete $inbufs->{$sock};
+ delete $readys->{$sock};
+
+ close($socket); # Close the client socket.
+ next;
+ }
+ } else { # Kludgy way to mark lond connection lost.
+ &logthis(
+ "<font color=red>CRITICAL lond connection lost</font>");
+ status("Connection lost");
+ $remotesock->shutdown(2);
+ &logthis("Attempting to open a new connection");
+ &openremote($conserver);
+ }
+
+ }
+ }
+
}
+#
+# HandleInput - Deals with input on client sockets.
+# Each socket has an associated input buffer.
+# For each readable socket, the currently available
+# data is appended to this buffer.
+# If necessary, the buffer is created.
+# On various failures, we may shutdown the client.
+# Parameters:
+# $selvec - Vector of readable sockets.
+# \%sockets - Refers to the Hash of sockets indexed by sockets.
+# Each of these may or may not have it's fd bit set
+# in the $selvec.
+# \%ibufs - Refers to the hash of input buffers indexed by socket.
+# \%obufs - Hash of output buffers indexed by socket.
+# \%ready - Hash of ready flags indicating the existence of a completed
+# Request.
+sub HandleInput
+{
+
+ # Marshall the parameters. Note that the hashes are actually
+ # references not values.
+
+ my $selvec = shift;
+ my $sockets = shift;
+ my $ibufs = shift;
+ my $obufs = shift;
+ my $ready = shift;
+ my $sock;
+
+ if($DEBUG) {
+ &logthis("Entered HandleInput\n");
+ }
+ foreach $sock (keys %$sockets) {
+ my $socket = $sockets->{$sock};
+ if(vec($selvec, $sock, 1)) { # Socket which is readable.
+
+ # Attempt to read the data and do error management.
+ my $data = '';
+ my $rv = $socket->recv($data, POSIX::BUFSIZ, 0);
+ if($DEBUG) {
+ &logthis("Received $data from socket");
+ }
+ unless (defined($rv) && length $data) {
+
+ # Read an end of file.. this is a disconnect from the peer.
+
+ delete $sockets->{$sock};
+ delete $ibufs->{$sock};
+ delete $obufs->{$sock};
+ delete $ready->{$sock};
+
+ status("Idle");
+ close $socket;
+ next;
+ }
+ # Append the read data to the input buffer. If the buffer
+ # now contains a \n the request is complete and we can
+ # mark this in the $ready hash (one request for each \n.)
+
+ $ibufs->{$sock} .= $data;
+ while($ibufs->{$sock} =~ s/(.*\n)//) {
+ push(@{$ready->{$sock}}, $1);
+ }
+
+ }
+ }
+ # Now handle any requests which are ready:
+
+ foreach $client (keys %ready) {
+ handle($client);
+ }
}
-# ------------------------------------------------------- End of make_new_child
+# DoSelect: does a select with no timeout. On signal (errno == EINTR),
+# the select is retried until there are items in the returned
+# vectors.
+#
+# Parameters:
+# \$readvec - Reference to a vector of file descriptors to
+# check for readability.
+# \$writevec - Reference to a vector of file descriptors to check for
+# writability.
+# On exit, the referents are modified with vectors indicating which
+# file handles are readable/writable.
+#
+sub DoSelect {
+ my $readvec = shift;
+ my $writevec= shift;
+ my $outs;
+ my $ins;
+
+ while (1) {
+ my $nfds = select( $ins = $$readvec, $outs = $$writevec, undef, undef);
+ if($nfds) {
+ if($DEBUG) {
+ &logthis("select exited with ".$nfds." fds\n");
+ &logthis("ins = ".unpack("b*",$ins).
+ " readvec = ".unpack("b*",$$readvec)."\n");
+ &logthis("outs = ".unpack("b*",$outs).
+ " writevec = ".unpack("b*",$$writevec)."\n");
+ }
+ $$readvec = $ins;
+ $$writevec = $outs;
+ return;
+ } else {
+ if($DEBUG) {
+ &logthis("Select exited with no bits set in mask\n");
+ }
+ die "Select failed" unless $! == EINTR;
+ }
+ }
+}
# handle($socket) deals with all pending requests for $client
+#
sub handle {
# requests are in $ready{$client}
# send output to $outbuffer{$client}
@@ -505,7 +684,6 @@ sub handle {
}
}
# ---------------------------------------------------------- End make_new_child
-}
# nonblock($socket) puts socket into nonblocking mode
sub nonblock {
@@ -525,75 +703,89 @@ sub openremote {
my $conserver=shift;
-&status("Opening TCP");
+ &status("Opening TCP $conserver");
my $st=120+int(rand(240)); # Sleep before opening:
-unless (
- $remotesock = IO::Socket::INET->new(PeerAddr => $hostip{$conserver},
- PeerPort => $perlvar{'londPort'},
- Proto => "tcp",
- Type => SOCK_STREAM)
- ) {
-
- &logthis(
-"<font color=blue>WARNING: Couldn't connect to $conserver ($st secs): </font>");
- sleep($st);
- exit;
- };
+ unless (
+ $remotesock = IO::Socket::INET->new(PeerAddr => $hostip{$conserver},
+ PeerPort => $perlvar{'londPort'},
+ Proto => "tcp",
+ Type => SOCK_STREAM)
+ ) {
+
+ &logthis(
+ "<font color=blue>WARNING: Couldn't connect to $conserver ($st secs): </font>");
+ sleep($st);
+ exit;
+ };
# ----------------------------------------------------------------- Init dialog
-&logthis("<font color=green>INFO Connected to $conserver, initing </font>");
-&status("Init dialogue: $conserver");
+ &logthis("<font color=green>INFO Connected to $conserver, initing</font>");
+ &status("Init dialogue: $conserver");
$answer = londtransaction($remotesock, "init", 60);
chomp($answer);
$answer = londtransaction($remotesock, $answer, 60);
chomp($answer);
-
- if ($@=~/timeout/) {
- &logthis("Timed out during init.. exiting");
- exit;
- }
-if ($answer ne 'ok') {
- &logthis("Init reply: >$answer<");
- my $st=120+int(rand(240));
- &logthis(
-"<font color=blue>WARNING: Init failed ($st secs)</font>");
- sleep($st);
- exit;
-}
+ if ($@=~/timeout/) {
+ &logthis("Timed out during init.. exiting");
+ exit;
+ }
-sleep 5;
-&status("Ponging");
-print $remotesock "pong\n";
-$answer=<$remotesock>;
-chomp($answer);
-if ($answer!~/^$conserver/) {
- &logthis("Pong reply: >$answer<");
-}
+ if ($answer ne 'ok') {
+ &logthis("Init reply: >$answer<");
+ my $st=120+int(rand(240));
+ &logthis("<font color=blue>WARNING: Init failed ($st secs)</font>");
+ sleep($st);
+ exit;
+ }
+
+ $answer = londtransaction($remotesock,"sethost:$conserver",60);
+ chomp($answer);
+ if ( $answer ne 'ok') {
+ &logthis('<font color="blue">WARNING: unable to specify remote host'.
+ $answer.'</font>');
+ }
+
+ $answer = londtransaction($remotesock,"version:$VERSION",60);
+ chomp($answer);
+ if ($answer =~ /^version:/) {
+ $remoteVERSION=(split(/:/,$answer))[1];
+ } else {
+ &logthis('<font color="blue">WARNING: request remote version failed :'.
+ $answer.': my version is :'.$VERSION.':</font>');
+ }
+
+ sleep 5;
+ &status("Ponging $conserver");
+ print $remotesock "pong\n";
+ $answer=<$remotesock>;
+ chomp($answer);
+ if ($answer!~/^$conserver/) {
+ &logthis("Pong reply: >$answer<");
+ }
# ----------------------------------------------------------- Initialize cipher
-&status("Initialize cipher");
-print $remotesock "ekey\n";
-my $buildkey=<$remotesock>;
-my $key=$conserver.$perlvar{'lonHostID'};
-$key=~tr/a-z/A-Z/;
-$key=~tr/G-P/0-9/;
-$key=~tr/Q-Z/0-9/;
-$key=$key.$buildkey.$key.$buildkey.$key.$buildkey;
-$key=substr($key,0,32);
-my $cipherkey=pack("H32",$key);
-if ($cipher=new IDEA $cipherkey) {
- &logthis("Secure connection initialized");
-} else {
- my $st=120+int(rand(240));
- &logthis(
- "<font color=blue>WARNING: ".
- "Could not establish secure connection ($st secs)!</font>");
- sleep($st);
- exit;
-}
+ &status("Initialize cipher");
+ print $remotesock "ekey\n";
+ my $buildkey=<$remotesock>;
+ my $key=$conserver.$perlvar{'lonHostID'};
+ $key=~tr/a-z/A-Z/;
+ $key=~tr/G-P/0-9/;
+ $key=~tr/Q-Z/0-9/;
+ $key=$key.$buildkey.$key.$buildkey.$key.$buildkey;
+ $key=substr($key,0,32);
+ my $cipherkey=pack("H32",$key);
+ if ($cipher=new IDEA $cipherkey) {
+ &logthis("Secure connection initialized");
+ } else {
+ my $st=120+int(rand(240));
+ &logthis("<font color=blue>WARNING: ".
+ "Could not establish secure connection ($st secs)!</font>");
+ sleep($st);
+ exit;
+ }
&logthis("<font color=green> Remote open success </font>");
}
@@ -675,8 +867,8 @@ sub HUPSMAN { # sig
local($SIG{CHLD}) = 'IGNORE'; # we're going to kill our children
&hangup();
&logthis("<font color=red>CRITICAL: Restarting</font>");
- unlink("$execdir/logs/lonc.pid");
my $execdir=$perlvar{'lonDaemons'};
+ unlink("$execdir/logs/lonc.pid");
exec("$execdir/lonc"); # here we go again
}
@@ -695,8 +887,25 @@ sub checkchildren {
sub USRMAN {
&logthis("USR1: Trying to establish connections again");
- %childatt=();
- &checkchildren();
+ #
+ # It is really important not to just clear the childatt hash or we will
+ # lose all memory of the children. What we really want to do is this:
+ # For each index where childatt is >= $childmaxattempts
+ # Zero the associated counter and do a make_child for the host.
+ # Regardles, the childatt entry is zeroed:
+ my $host;
+ foreach $host (keys %childatt) {
+ if ($childatt{$host} >= $childmaxattempts) {
+ $childatt{$host} = 0;
+ &logthis("<font color=green>INFO: Restarting child for server: "
+ .$host."</font>\n");
+ make_new_child($host);
+ }
+ else {
+ $childatt{$host} = 0;
+ }
+ }
+ &checkchildren(); # See if any children are still dead...
}
# -------------------------------------------------- Non-critical communication
@@ -781,12 +990,12 @@ sub londtransaction {
alarm(0);
};
} else {
- if($DEBUG) {
- &logthis("Timeout on send in londtransaction");
- }
+ &logthis("lonc - suiciding on send Timeout");
+ die("lonc - suiciding on send Timeout");
}
- if( ($@ =~ /timeout/) && ($DEBUG)) {
- &logthis("Timeout on receive in londtransaction");
+ if ($@ =~ /timeout/) {
+ &logthis("lonc - suiciding on read Timeout");
+ die("lonc - suiciding on read Timeout");
}
#
# Restore the initial sigmask set.
@@ -841,6 +1050,7 @@ sub status {
my $now=time;
my $local=localtime($now);
$status=$local.': '.$what;
+ $0='lonc: '.$what.' '.$local;
}