Koha/C4/SIP/SIPServer.pm
Joe Atzberger (siptest 5aecb46ad0 SIP - Lots of regexp hacking of input streams and verbose debugging feedback.
The basic problem is that the SIP logic doesn't know where the
input is coming from.  It might be a RAW socket, and it might
be telnet.  If it is telnet, although the specs declare a
character set (from MS, unfortunately), they do not specify a telnet
implementation.  So you might get telnet handshaking or
renegotiations in the middle of an otherwise peaceful session and
these should not be taken as SIP commands.  Patches include a move
towards using $CRLF from Socket to avoid problems w/ foreign platform
mapping \n and \r to \015 or \012.

Signed-off-by: Joshua Ferraro <jmf@liblime.com>
2008-06-20 06:12:42 -05:00

307 lines
8.8 KiB
Perl

package SIPServer;
use strict;
use warnings;
# use Exporter;
use Sys::Syslog qw(syslog);
use Net::Server::PreFork;
use IO::Socket::INET;
use Socket qw(:DEFAULT :crlf);
use Data::Dumper; # For debugging
require UNIVERSAL::require;
#use Sip qw(readline);
use Sip::Constants qw(:all);
use Sip::Configuration;
use Sip::Checksum qw(checksum verify_cksum);
use Sip::MsgType;
use constant LOG_SIP => "local6"; # Local alias for the logging facility
use vars qw(@ISA $VERSION);
BEGIN {
$VERSION = 1.01;
@ISA = qw(Net::Server::PreFork);
}
#
# Main # not really, since package SIPServer
#
# FIXME: Is this a module or a script?
# A script with no MAIN namespace?
# A module that takes command line args?
my %transports = (
RAW => \&raw_transport,
telnet => \&telnet_transport,
# http => \&http_transport, # for http just use the OPAC
);
#
# Read configuration
#
my $config = new Sip::Configuration $ARGV[0];
print STDERR "SIPServer config: \n" . Dumper($config) . "\nEND SIPServer config.\n";
my @parms;
#
# Ports to bind
#
foreach my $svc (keys %{$config->{listeners}}) {
push @parms, "port=" . $svc;
}
#
# Logging
#
push @parms, "log_file=Sys::Syslog", "syslog_ident=acs-server",
"syslog_facility=" . LOG_SIP;
#
# Server Management: set parameters for the Net::Server::PreFork
# module. The module silently ignores parameters that it doesn't
# recognize, and complains about invalid values for parameters
# that it does.
#
if (defined($config->{'server-params'})) {
while (my ($key, $val) = each %{$config->{'server-params'}}) {
push @parms, $key . '=' . $val;
}
}
print "Params for Net::Server::PreFork : \n" . Dumper(\@parms);
#
# This is the main event.
__PACKAGE__ ->run(@parms);
#
# Child
#
# process_request is the callback used by Net::Server to handle
# an incoming connection request.
sub process_request {
my $self = shift;
my $service;
my ($sockaddr, $port, $proto);
my $transport;
$self->{config} = $config;
my $sockname = getsockname(STDIN);
($port, $sockaddr) = sockaddr_in($sockname);
$sockaddr = inet_ntoa($sockaddr);
$proto = $self->{server}->{client}->NS_proto();
$self->{service} = $config->find_service($sockaddr, $port, $proto);
if (!defined($self->{service})) {
syslog("LOG_ERR", "process_request: Unknown recognized server connection: %s:%s/%s", $sockaddr, $port, $proto);
die "process_request: Bad server connection";
}
$transport = $transports{$self->{service}->{transport}};
if (!defined($transport)) {
syslog("LOG_WARNING", "Unknown transport '%s', dropping", $service->{transport});
return;
} else {
&$transport($self);
}
}
#
# Transports
#
sub raw_transport {
my $self = shift;
my ($input);
my $service = $self->{service};
my $strikes = 3;
eval {
local $SIG{ALRM} = sub { die "raw_transport Timed Out!\n"; };
syslog("LOG_DEBUG", "raw_transport: timeout is %d", $service->{timeout});
while ($strikes--) {
alarm $service->{timeout};
$input = Sip::read_SIP_packet(*STDIN);
alarm 0;
if (!$input) {
# EOF on the socket
syslog("LOG_INFO", "raw_transport: shutting down: EOF during login");
return;
}
$input =~ s/[\r\n]+$//sm; # Strip off trailing line terminator(s)
last if Sip::MsgType::handle($input, $self, LOGIN);
}
};
if (length $@) {
syslog("LOG_ERR", "raw_transport: LOGIN ERROR: '$@'");
die "raw_transport: login error (timeout? $@), exiting";
} elsif (!$self->{account}) {
syslog("LOG_ERR", "raw_transport: LOGIN FAILED");
die "raw_transport: Login failed (no account), exiting";
}
syslog("LOG_DEBUG", "raw_transport: uname/inst: '%s/%s'",
$self->{account}->{id},
$self->{account}->{institution});
$self->sip_protocol_loop();
syslog("LOG_INFO", "raw_transport: shutting down");
}
sub get_clean_string ($) {
my $string = shift;
if (defined $string) {
syslog("LOG_DEBUG", "get_clean_string pre-clean(length %s): %s", length($string), $string);
chomp($string);
$string =~ s/^[^A-z0-9]+//;
$string =~ s/[^A-z0-9]+$//;
syslog("LOG_DEBUG", "get_clean_string post-clean(length %s): %s", length($string), $string);
} else {
syslog("LOG_INFO", "get_clean_string called on undefined");
}
return $string;
}
sub get_clean_input {
local $/ = "\012";
my $in = <STDIN>;
$in = get_clean_string($in);
while (my $extra = <STDIN>){
syslog("LOG_ERR", "get_clean_input got extra lines: %s", $extra);
}
return $in;
}
sub telnet_transport {
my $self = shift;
my ($uid, $pwd);
my $strikes = 3;
my $account = undef;
my $input;
my $config = $self->{config};
my $timeout = $self->{service}->{timeout} || $config->{timeout} || 30;
syslog("LOG_DEBUG", "telnet_transport: timeout is %s", $timeout);
eval {
local $SIG{ALRM} = sub { die "telnet_transport: Timed Out ($timeout seconds)!\n"; };
local $| = 1; # Unbuffered output
$/ = "\015"; # Internet Record Separator (lax version)
# Until the terminal has logged in, we don't trust it
# so use a timeout to protect ourselves from hanging.
while ($strikes--) {
print "login: ";
alarm $timeout;
# $uid = &get_clean_input;
$uid = <STDIN>;
print "password: ";
# $pwd = &get_clean_input || '';
$pwd = <STDIN>;
alarm 0;
syslog("LOG_DEBUG", "telnet_transport 1: uid length %s, pwd length %s", length($uid), length($pwd));
$uid = get_clean_string ($uid);
$pwd = get_clean_string ($pwd);
syslog("LOG_DEBUG", "telnet_transport 2: uid length %s, pwd length %s", length($uid), length($pwd));
# $uid =~ s/^\s+//; #
# $pwd =~ s/^\s+//; #
# $uid =~ s/[\r\n]+$//gms; #
# $pwd =~ s/[\r\n]+$//gms; #
# $uid =~ s/[[:cntrl:]]//g; #
# $pwd =~ s/[[:cntrl:]]//g; #
# syslog("LOG_DEBUG", "telnet_transport 3: uid length %s, pwd length %s", length($uid), length($pwd));
if (exists ($config->{accounts}->{$uid})
&& ($pwd eq $config->{accounts}->{$uid}->password())) {
$account = $config->{accounts}->{$uid};
Sip::MsgType::login_core($self,$uid,$pwd) and last;
}
syslog("LOG_WARNING", "Invalid login attempt: '%s'", ($uid||''));
print("Invalid login$CRLF");
}
}; # End of eval
if ($@) {
syslog("LOG_ERR", "telnet_transport: Login timed out");
die "Telnet Login Timed out";
} elsif (!defined($account)) {
syslog("LOG_ERR", "telnet_transport: Login Failed");
die "Login Failure";
} else {
print "Login OK. Initiating SIP$CRLF";
}
$self->{account} = $account;
syslog("LOG_DEBUG", "telnet_transport: uname/inst: '%s/%s'", $account->{id}, $account->{institution});
$self->sip_protocol_loop();
syslog("LOG_INFO", "telnet_transport: shutting down");
}
#
# The terminal has logged in, using either the SIP login process
# over a raw socket, or via the pseudo-unix login provided by the
# telnet transport. From that point on, both the raw and the telnet
# processes are the same:
sub sip_protocol_loop {
my $self = shift;
my $service = $self->{service};
my $config = $self->{config};
my $input;
# The spec says the first message will be:
# SIP v1: SC_STATUS
# SIP v2: LOGIN (or SC_STATUS via telnet?)
# But it might be SC_REQUEST_RESEND. As long as we get
# SC_REQUEST_RESEND, we keep waiting.
# Comprise reports that no other ILS actually enforces this
# constraint, so we'll relax about it too.
# Using the SIP "raw" login process, rather than telnet,
# requires the LOGIN message and forces SIP 2.00. In that
# case, the LOGIN message has already been processed (above).
#
# In short, we'll take any valid message here.
#my $expect = SC_STATUS;
my $expect = '';
my $strikes = 3;
while ($input = Sip::read_SIP_packet(*STDIN)) {
# begin input hacks ... a cheap stand in for better Telnet layer
$input =~ s/^[^A-z0-9]+//s; # Kill leading bad characters... like Telnet handshakers
$input =~ s/[^A-z0-9]+$//s; # Same on the end, should get DOSsy ^M line-endings too.
while (chomp($input)) {warn "Extra line ending on input";}
unless ($input) {
if ($strikes--) {
syslog("LOG_ERR", "sip_protocol_loop: empty input skipped");
next;
} else {
syslog("LOG_ERR", "sip_protocol_loop: quitting after too many errors");
die "sip_protocol_loop: quitting after too many errors";
}
}
# end cheap input hacks
my $status = Sip::MsgType::handle($input, $self, $expect);
if (!$status) {
syslog("LOG_ERR", "sip_protocol_loop: failed to handle %s",substr($input,0,2));
die "sip_protocol_loop: failed Sip::MsgType::handle('$input', $self, '$expect')";
}
next if $status eq REQUEST_ACS_RESEND;
if ($expect && ($status ne $expect)) {
# We received a non-"RESEND" that wasn't what we were expecting.
syslog("LOG_ERR", "sip_protocol_loop: expected %s, received %s, exiting", $expect, $input);
die "sip_protocol_loop: exiting: expected '$expect', received '$status'";
}
# We successfully received and processed what we were expecting
$expect = '';
}
}
1;
__END__