Koha/C4/SIP/Sip.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

217 lines
5.4 KiB
Perl

#
# Sip.pm: General Sip utility functions
#
package Sip;
use strict;
use warnings;
use English;
use Exporter;
use Sys::Syslog qw(syslog);
use POSIX qw(strftime);
use Socket qw(:crlf);
use Sip::Constants qw(SIP_DATETIME);
use Sip::Checksum qw(checksum);
use vars qw($VERSION @ISA @EXPORT_OK %EXPORT_TAGS);
BEGIN {
$VERSION = 1.00;
@ISA = qw(Exporter);
@EXPORT_OK = qw(y_or_n timestamp add_field maybe_add add_count
denied sipbool boolspace write_msg read_SIP_packet
$error_detection $protocol_version $field_delimiter
$last_response);
%EXPORT_TAGS = (
all => [qw(y_or_n timestamp add_field maybe_add
add_count denied sipbool boolspace write_msg
read_SIP_packet
$error_detection $protocol_version
$field_delimiter $last_response)]);
}
our $error_detection = 0;
our $protocol_version = 1;
our $field_delimiter = '|'; # Protocol Default
# We need to keep a copy of the last message we sent to the SC,
# in case there's a transmission error and the SC sends us a
# REQUEST_ACS_RESEND. If we receive a REQUEST_ACS_RESEND before
# we've ever sent anything, then we are to respond with a
# REQUEST_SC_RESEND (p.16)
our $last_response = '';
sub timestamp {
my $time = $_[0] || time();
return strftime(SIP_DATETIME, localtime($time));
}
#
# add_field(field_id, value)
# return constructed field value
#
sub add_field {
my ($field_id, $value) = @_;
my ($i, $ent);
if (!defined($value)) {
syslog("LOG_DEBUG", "add_field: Undefined value being added to '%s'",
$field_id);
$value = '';
}
# Replace any occurences of the field delimiter in the
# field value with the HTML character entity
$ent = sprintf("&#%d;", ord($field_delimiter));
while (($i = index($value, $field_delimiter)) != ($[-1)) {
substr($value, $i, 1) = $ent;
}
return $field_id . $value . $field_delimiter;
}
#
# maybe_add(field_id, value):
# If value is defined and non-empty, then return the
# constructed field value, otherwise return the empty string
#
sub maybe_add {
my ($fid, $value) = @_;
return (defined($value) && $value) ? add_field($fid, $value) : '';
}
#
# add_count() produce fixed four-character count field,
# or a string of four spaces if the count is invalid for some
# reason
#
sub add_count {
my ($label, $count) = @_;
# If the field is unsupported, it will be undef, return blanks
# as per the spec.
if (!defined($count)) {
return ' ' x 4;
}
$count = sprintf("%04d", $count);
if (length($count) != 4) {
syslog("LOG_WARNING", "handle_patron_info: %s wrong size: '%s'",
$label, $count);
$count = ' ' x 4;
}
return $count;
}
#
# denied($bool)
# if $bool is false, return true. This is because SIP statuses
# are inverted: we report that something has been denied, not that
# it's permitted. For example, 'renewal priv. denied' of 'Y' means
# that the user's not permitted to renew. I assume that the ILS has
# real positive tests.
#
sub denied {
my $bool = shift;
return boolspace(!$bool);
}
sub sipbool {
my $bool = shift;
return $bool ? 'Y' : 'N';
}
#
# boolspace: ' ' is false, 'Y' is true. (don't ask)
#
sub boolspace {
my $bool = shift;
return $bool ? 'Y' : ' ';
}
# Read a packet from $file, using the correct record separator
#
sub read_SIP_packet {
my $record;
my $fh = shift or syslog("LOG_ERR", "read_SIP_packet: no filehandle argument!");
my $len1 = 999;
# local $/ = "\012"; # Internet Record Separator (lax version)
{ # adapted from http://perldoc.perl.org/5.8.8/functions/readline.html
for (my $tries=1; $tries<=3; $tries++) {
undef $!;
$record = readline($fh);
if (defined($record)) {
while(chomp($record)){1;}
$len1 = length($record);
syslog("LOG_DEBUG", "read_SIP_packet, INPUT MSG: '$record'");
$record =~ s/^\s*[^A-z0-9]+//s;
$record =~ s/[^A-z0-9]+$//s;
$record =~ s/\015?\012//g;
$record =~ s/\015?\012//s;
$record =~ s/\015*\012*$//s; # treat as one line to include the extra linebreaks we are trying to remove!
while(chomp($record)){1;}
if ($record) {
last; # success
}
} else {
if ($!) {
syslog("LOG_DEBUG", "read_SIP_packet (try #$tries) ERROR: $!");
# die "read_SIP_packet ERROR: $!";
warn "read_SIP_packet ERROR: $!";
}
}
}
}
if ($record) {
my $len2 = length($record);
syslog("LOG_INFO", "read_SIP_packet, INPUT MSG: '$record'") if $record;
($len1 != $len2) and syslog("LOG_DEBUG", "read_SIP_packet, trimmed %s character(s) (after chomps).", $len1-$len2);
} else {
syslog("LOG_WARNING", "read_SIP_packet input %s, end of input.", (defined($record)? "empty ($record)" : 'undefined'));
}
return $record;
}
#
# write_msg($msg, $file)
#
# Send $msg to the SC. If error detection is active, then
# add the sequence number (if $seqno is non-zero) and checksum
# to the message, and save the whole thing as $last_response
#
# If $file is set, then it's a file handle: write to it, otherwise
# just write to the default destination.
#
sub write_msg {
my ($self, $msg, $file) = @_;
my $cksum;
if ($error_detection) {
if (defined($self->{seqno})) {
$msg .= 'AY' . $self->{seqno};
}
$msg .= 'AZ';
$cksum = checksum($msg);
$msg .= sprintf('%04.4X', $cksum);
}
if ($file) {
print $file "$msg$CRLF";
syslog("LOG_DEBUG", "write_msg outputting to $file");
} else {
print "$msg$CRLF";
}
syslog("LOG_INFO", "OUTPUT MSG: '$msg'");
$last_response = $msg;
}
1;