--- loncom/LondConnection.pm 2003/06/13 02:56:45 1.6 +++ loncom/LondConnection.pm 2004/03/02 22:38:07 1.29 @@ -1,7 +1,7 @@ # This module defines and implements a class that represents # a connection to a lond daemon. # -# $Id: LondConnection.pm,v 1.6 2003/06/13 02:56:45 foxr Exp $ +# $Id: LondConnection.pm,v 1.29 2004/03/02 22:38:07 albertel Exp $ # # Copyright Michigan State University Board of Trustees # @@ -25,8 +25,10 @@ # # http://www.lon-capa.org/ # + package LondConnection; +use strict; use IO::Socket; use IO::Socket::INET; use IO::Handle; @@ -34,23 +36,76 @@ use IO::File; use Fcntl; use POSIX; use Crypt::IDEA; -use LONCAPA::Configuration; -use LONCAPA::HashIterator; + + + + my $DebugLevel=0; +my %hostshash; +my %perlvar; + +# +# Set debugging level +# +sub SetDebug { + $DebugLevel = shift; +} + +# +# The config read is done in this way to support the read of +# the non-default configuration file in the +# event we are being used outside of loncapa. +# + +my $ConfigRead = 0; # Read the configuration file for apache to get the perl # variable set. -my $perlvarref = LONCAPA::Configuration::read_conf('loncapa.conf'); -my %perlvar = %{$perlvarref}; -my $hoststab = - LONCAPA::Configuration::read_hosts( - "$perlvar{'lonTabDir'}/hosts.tab") || - die "Can't read host table!!"; -my %hostshash = %{$hoststab}; +sub ReadConfig { + my $perlvarref = read_conf('loncapa.conf'); + %perlvar = %{$perlvarref}; + my $hoststab = read_hosts( + "$perlvar{lonTabDir}/hosts.tab") || + die "Can't read host table!!"; + %hostshash = %{$hoststab}; + $ConfigRead = 1; + +} + +# +# Read a foreign configuration. +# This sub is intended for the cases where the package +# will be read from outside the LonCAPA environment, in that case +# the client will need to explicitly provide: +# - A file in hosts.tab format. +# - Some idea of the 'lonCAPA' name of the local host (for building +# the encryption key). +# +# Parameters: +# MyHost - Name of this host as far as LonCAPA is concerned. +# Filename - Name of a hosts.tab formatted file that will be used +# to build up the hosts table. +# +sub ReadForeignConfig { + my $MyHost = shift; + my $Filename = shift; + + &Debug(4, "ReadForeignConfig $MyHost $Filename\n"); + + $perlvar{lonHostID} = $MyHost; # Rmember my host. + my $hosttab = read_hosts($Filename) || + die "Can't read hosts table!!"; + %hostshash = %{$hosttab}; + if($DebugLevel > 3) { + foreach my $host (keys %hostshash) { + print "host $host => $hostshash{$host}\n"; + } + } + $ConfigRead = 1; -close(CONFIG); +} sub Debug { my $level = shift; @@ -64,17 +119,19 @@ sub Debug { =head2 Dump -Dump the internal state of the object: For debugging purposes. +Dump the internal state of the object: For debugging purposes, to stderr. =cut sub Dump { my $self = shift; - print "Dumping LondConnectionObject:\n"; + my $key; + my $value; + print STDERR "Dumping LondConnectionObject:\n"; while(($key, $value) = each %$self) { - print "$key -> $value\n"; + print STDERR "$key -> $value\n"; } - print "-------------------------------\n"; + print STDERR "-------------------------------\n"; } =pod @@ -97,6 +154,7 @@ sub Transition { } + =pod =head2 new @@ -119,6 +177,11 @@ sub new { my $class = shift; # class name. my $Hostname = shift; # Name of host to connect to. my $Port = shift; # Port to connect + + if (!$ConfigRead) { + ReadConfig(); + $ConfigRead = 1; + } &Debug(4,$class."::new( ".$Hostname.",".$Port.")\n"); # The host must map to an entry in the hosts table: @@ -128,6 +191,7 @@ sub new { # LoncapaHim fields of the object respectively. # if (!exists $hostshash{$Hostname}) { + &Debug(8, "No Such host $Hostname"); return undef; # No such host!!! } my @ConfigLine = @{$hostshash{$Hostname}}; @@ -135,25 +199,27 @@ sub new { Debug(5, "Connecting to ".$DnsName); # Now create the object... my $self = { Host => $DnsName, - LoncapaHim => $Hostname, - Port => $Port, - State => "Initialized", - TransactionRequest => "", - TransactionReply => "", - InformReadable => 0, - InformWritable => 0, - TimeoutCallback => undef, - TransitionCallback => undef, - Timeoutable => 0, - TimeoutValue => 60, - TimeoutRemaining => 0, - CipherKey => "", - Cipher => undef}; + LoncapaHim => $Hostname, + Port => $Port, + State => "Initialized", + TransactionRequest => "", + TransactionReply => "", + InformReadable => 0, + InformWritable => 0, + TimeoutCallback => undef, + TransitionCallback => undef, + Timeoutable => 0, + TimeoutValue => 30, + TimeoutRemaining => 0, + CipherKey => "", + LondVersion => "Unknown", + Cipher => undef}; bless($self, $class); unless ($self->{Socket} = IO::Socket::INET->new(PeerHost => $self->{Host}, PeerPort => $self->{Port}, Type => SOCK_STREAM, - Proto => "tcp")) { + Proto => "tcp", + Timeout => 3)) { return undef; # Inidicates the socket could not be made. } # @@ -161,13 +227,14 @@ sub new { # $self->Transition("Connected"); $self->{InformWritable} = 1; # When socket is writable we send init + $self->{Timeoutable} = 1; # Timeout allowed during startup negotiation. $self->{TransactionRequest} = "init\n"; # # Set socket to nonblocking I/O. # my $socket = $self->{Socket}; - $flags = fcntl($socket->fileno, F_GETFL,0); + my $flags = fcntl($socket->fileno, F_GETFL,0); if($flags == -1) { $socket->close; return undef; @@ -212,14 +279,21 @@ sub Readable { my $self = shift; my $socket = $self->{Socket}; my $data = ''; - my $rv = $socket->recv($data, POSIX::BUFSIZ, 0); + my $rv; + if ($socket) { + eval { + $rv = $socket->recv($data, POSIX::BUFSIZ, 0); + } + } else { + $self->Transition("Disconnected"); + return -1; + } my $errno = $! + 0; # Force numeric context. - unless (defined($rv) && length($data)) { # Read failed, + unless (defined($rv) && length $data) {# Read failed, if(($errno == POSIX::EWOULDBLOCK) || ($errno == POSIX::EAGAIN) || - ($errno == POSIX::EINTR) || - ($errno == 0)) { + ($errno == POSIX::EINTR)) { return 0; } @@ -234,10 +308,10 @@ sub Readable { &Debug(9,"Received from host: ".$data); $self->{TransactionReply} .= $data; - if($self->{TransactionReply} =~ /(.*\n)/) { + if($self->{TransactionReply} =~ m/\n$/) { &Debug(8,"Readable End of line detected"); if ($self->{State} eq "Initialized") { # We received the challenge: - if($self->{TransactionReply} eq "refused") { # Remote doesn't have + if($self->{TransactionReply} eq "refused\n") { # Remote doesn't have $self->Transition("Disconnected"); # in host tables. $socket->close(); @@ -251,8 +325,27 @@ sub Readable { $self->Transition("ChallengeReceived"); $self->{TimeoutRemaining} = $self->{TimeoutValue}; return 0; - } elsif ($self->{State} eq "ChallengeReplied") { # should be ok. - if($self->{TransactionReply} != "ok\n") { + } elsif ($self->{State} eq "ChallengeReplied") { + if($self->{TransactionReply} ne "ok\n") { + $self->Transition("Disconnected"); + $socket->close(); + return -1; + } + $self->Transition("RequestingVersion"); + $self->{InformReadable} = 0; + $self->{InformWritable} = 1; + $self->{TransactionRequest} = "version\n"; + return 0; + } elsif ($self->{State} eq "ReadingVersionString") { + $self->{LondVersion} = chomp($self->{TransactionReply}); + $self->Transition("SetHost"); + $self->{InformReadable} = 0; + $self->{InformWritable} = 1; + my $peer = $self->{LoncapaHim}; + $self->{TransactionRequest}= "sethost:$peer\n"; + return 0; + } elsif ($self->{State} eq "HostSet") { # should be ok. + if($self->{TransactionReply} ne "ok\n") { $self->Transition("Disconnected"); $socket->close(); return -1; @@ -272,7 +365,7 @@ sub Readable { $key=substr($key,0,32); my $cipherkey=pack("H32",$key); $self->{Cipher} = new IDEA $cipherkey; - if($self->{Cipher} == undef) { + if($self->{Cipher} eq undef) { $self->Transition("Disconnected"); $socket->close(); return -1; @@ -328,7 +421,18 @@ Returns 0 if successful, or -1 if not. sub Writable { my $self = shift; # Get reference to the object. my $socket = $self->{Socket}; - my $nwritten = $socket->send($self->{TransactionRequest}, 0); + my $nwritten; + if ($socket) { + eval { + $nwritten = $socket->send($self->{TransactionRequest}, 0); + } + } else { + # For whatever reason, there's no longer a socket left. + + + $self->Transition("Disconnected"); + return -1; + } my $errno = $! + 0; unless (defined $nwritten) { if($errno != POSIX::EINTR) { @@ -337,41 +441,45 @@ sub Writable { } } - if (($rv >= 0) || + if (($nwritten >= 0) || ($errno == POSIX::EWOULDBLOCK) || ($errno == POSIX::EAGAIN) || ($errno == POSIX::EINTR) || ($errno == 0)) { substr($self->{TransactionRequest}, 0, $nwritten) = ""; # rmv written part - if(length $self->{TransactionRequest} == 0) { - $self->{InformWritable} = 0; - $self->{InformReadable} = 1; - $self->{TransactionReply} = ''; - # - # Figure out the next state: - # - if($self->{State} eq "Connected") { - $self->Transition("Initialized"); - } elsif($self->{State} eq "ChallengeReceived") { - $self->Transition("ChallengeReplied"); - } elsif($self->{State} eq "RequestingKey") { - $self->Transition("ReceivingKey"); - $self->{InformWritable} = 0; - $self->{InformReadable} = 1; - $self->{TransactionReply} = ''; - } elsif ($self->{State} eq "SendingRequest") { - $self->Transition("ReceivingReply"); - $self->{TimeoutRemaining} = $self->{TimeoutValue}; - } elsif ($self->{State} eq "Disconnected") { - return -1; - } - return 0; - } - } else { # The write failed (e.g. partner disconnected). - $self->Transition("Disconnected"); - $socket->close(); - return -1; - } + if(length $self->{TransactionRequest} == 0) { + $self->{InformWritable} = 0; + $self->{InformReadable} = 1; + $self->{TransactionReply} = ''; + # + # Figure out the next state: + # + if($self->{State} eq "Connected") { + $self->Transition("Initialized"); + } elsif($self->{State} eq "ChallengeReceived") { + $self->Transition("ChallengeReplied"); + } elsif($self->{State} eq "RequestingVersion") { + $self->Transition("ReadingVersionString"); + } elsif ($self->{State} eq "SetHost") { + $self->Transition("HostSet"); + } elsif($self->{State} eq "RequestingKey") { + $self->Transition("ReceivingKey"); +# $self->{InformWritable} = 0; +# $self->{InformReadable} = 1; +# $self->{TransactionReply} = ''; + } elsif ($self->{State} eq "SendingRequest") { + $self->Transition("ReceivingReply"); + $self->{TimeoutRemaining} = $self->{TimeoutValue}; + } elsif ($self->{State} eq "Disconnected") { + return -1; + } + return 0; + } + } else { # The write failed (e.g. partner disconnected). + $self->Transition("Disconnected"); + $socket->close(); + return -1; + } } =pod @@ -497,7 +605,15 @@ Shuts down the socket. sub Shutdown { my $self = shift; my $socket = $self->GetSocket(); - $socket->shutdown(2); + Debug(5,"socket is -$socket-"); + if ($socket) { + # Ask lond to exit too. Non blocking so + # there is no cost for failure. + eval { + $socket->send("exit\n", 0); + $socket->shutdown(2); + } + } } =pod @@ -654,7 +770,7 @@ sub Decrypt { # Decode the data in 8 byte blocks. The string is encoded # as hex digits so there are two characters per byte: - $decrpyted = ""; + my $decrypted = ""; for(my $index = 0; $index < length($EncryptedString); $index += 16) { $decrypted .= $self->{Cipher}->decrypt( @@ -685,7 +801,7 @@ are used as follows: [1] - LonCapa domain name. [2] - Loncapa role (e.g. library or access). [3] - DNS name server hostname. - [4] - IP address (result of e.g. nslooup [3]). + [4] - IP address (result of e.g. nslookup [3]). [5] - Maximum connection count. [6] - Idle timeout for reducing connection count. [7] - Minimum connection count. @@ -697,6 +813,104 @@ sub GetHostIterator { return HashIterator->new(\%hostshash); } +########################################################### +# +# The following is an unashamed kludge that is here to +# allow LondConnection to be used outside of the +# loncapa environment (e.g. by lonManage). +# +# This is a textual inclusion of pieces of the +# Configuration.pm module. +# + + +my $confdir='/etc/httpd/conf/'; + +# ------------------- Subroutine read_conf: read LON-CAPA server configuration. +# This subroutine reads PerlSetVar values out of specified web server +# configuration files. +sub read_conf + { + my (@conf_files)=@_; + my %perlvar; + foreach my $filename (@conf_files,'loncapa_apache.conf') + { + if($DebugLevel > 3) { + print("Going to read $confdir.$filename\n"); + } + open(CONFIG,'<'.$confdir.$filename) or + die("Can't read $confdir$filename"); + while (my $configline=) + { + if ($configline =~ /^[^\#]*PerlSetVar/) + { + my ($unused,$varname,$varvalue)=split(/\s+/,$configline); + chomp($varvalue); + $perlvar{$varname}=$varvalue; + } + } + close(CONFIG); + } + if($DebugLevel > 3) { + print "Dumping perlvar:\n"; + foreach my $var (keys %perlvar) { + print "$var = $perlvar{$var}\n"; + } + } + my $perlvarref=\%perlvar; + return $perlvarref; +} + +#---------------------- Subroutine read_hosts: Read a LON-CAPA hosts.tab +# formatted configuration file. +# +my $RequiredCount = 5; # Required item count in hosts.tab. +my $DefaultMaxCon = 5; # Default value for maximum connections. +my $DefaultIdle = 1000; # Default connection idle time in seconds. +my $DefaultMinCon = 0; # Default value for minimum connections. + +sub read_hosts { + my $Filename = shift; + my %HostsTab; + + open(CONFIG,'<'.$Filename) or die("Can't read $Filename"); + while (my $line = ) { + if (!($line =~ /^\s*\#/)) { + my @items = split(/:/, $line); + if(scalar @items >= $RequiredCount) { + if (scalar @items == $RequiredCount) { # Only required items: + $items[$RequiredCount] = $DefaultMaxCon; + } + if(scalar @items == $RequiredCount + 1) { # up through maxcon. + $items[$RequiredCount+1] = $DefaultIdle; + } + if(scalar @items == $RequiredCount + 2) { # up through idle. + $items[$RequiredCount+2] = $DefaultMinCon; + } + { + my @list = @items; # probably not needed but I'm unsure of + # about the scope of item so... + $HostsTab{$list[0]} = \@list; + } + } + } + } + close(CONFIG); + my $hostref = \%HostsTab; + return ($hostref); +} +# +# Get the version of our peer. Note that this is only well +# defined if the state machine has hit the idle state at least +# once (well actually if it has transitioned out of +# ReadingVersionString The member data LondVersion is returned. +# +sub PeerVersion { + my $self = shift; + + return $self->{LondVersion}; +} + 1; =pod