C4/SIP/Sip.pm

   1 #
   2 # Sip.pm: General Sip utility functions
   3 #
   4
   5 package C4::SIP::Sip;
   6
   7 use strict;
   8 use warnings;
   9 use Exporter;
  10 use Encode;
  11 use Sys::Syslog qw(syslog);
  12 use POSIX qw(strftime);
  13 use Socket qw(:crlf);
  14 use IO::Handle;
  15
  16 use C4::SIP::Sip::Constants qw(SIP_DATETIME FID_SCREEN_MSG);
  17 use C4::SIP::Sip::Checksum qw(checksum);
  18
  19 use vars qw(@ISA @EXPORT_OK %EXPORT_TAGS);
  20
  21 BEGIN {
  22         @ISA = qw(Exporter);
  23
  24         @EXPORT_OK = qw(y_or_n timestamp add_field maybe_add add_count
  25                     denied sipbool boolspace write_msg read_SIP_packet
  26                     $error_detection $protocol_version $field_delimiter
  27                     $last_response);
  28
  29         %EXPORT_TAGS = (
  30                     all => [qw(y_or_n timestamp add_field maybe_add
  31                                add_count denied sipbool boolspace write_msg
  32                                read_SIP_packet
  33                                $error_detection $protocol_version
  34                                $field_delimiter $last_response)]);
  35 }
  36
  37 our $error_detection = 0;
  38 our $protocol_version = 1;
  39 our $field_delimiter = '|'; # Protocol Default
  40
  41 # We need to keep a copy of the last message we sent to the SC,
  42 # in case there's a transmission error and the SC sends us a
  43 # REQUEST_ACS_RESEND.  If we receive a REQUEST_ACS_RESEND before
  44 # we've ever sent anything, then we are to respond with a
  45 # REQUEST_SC_RESEND (p.16)
  46
  47 our $last_response = '';
  48
  49 sub timestamp {
  50     my $time = $_[0] || time();
  51     if ( ref $time eq 'DateTime') {
  52         return $time->strftime(SIP_DATETIME);
  53     } elsif ($time=~m/^(\d{4})\-(\d{2})\-(\d{2})/) {
  54         # passing a db returned date as is + bogus time
  55         return sprintf( '%04d%02d%02d    235900', $1, $2, $3);
  56     }
  57     return strftime(SIP_DATETIME, localtime($time));
  58 }
  59
  60 #
  61 # add_field(field_id, value)
  62 #    return constructed field value
  63 #
  64 sub add_field {
  65     my ($field_id, $value) = @_;
  66     my ($i, $ent);
  67
  68     if (!defined($value)) {
  69         syslog("LOG_DEBUG", "add_field: Undefined value being added to '%s'",
  70                $field_id);
  71                 $value = '';
  72     }
  73     $value=~s/\r/ /g; # CR terminates a sip message
  74                       # Protect against them in sip text fields
  75
  76     # Replace any occurrences of the field delimiter in the
  77     # field value with the HTML character entity
  78     $ent = sprintf("&#%d;", ord($field_delimiter));
  79
  80     while (($i = index($value, $field_delimiter)) != ($[-1)) {
  81                 substr($value, $i, 1) = $ent;
  82     }
  83
  84     return $field_id . $value . $field_delimiter;
  85 }
  86 #
  87 # maybe_add(field_id, value):
  88 #    If value is defined and non-empty, then return the
  89 #    constructed field value, otherwise return the empty string.
  90 #    NOTE: if zero is a valid value for your field, don't use maybe_add!
  91 #
  92 sub maybe_add {
  93     my ($fid, $value, $server) = @_;
  94
  95     if ( $fid eq FID_SCREEN_MSG && $server->{account}->{screen_msg_regex} ) {
  96         foreach my $regex (
  97             ref $server->{account}->{screen_msg_regex} eq "ARRAY"
  98             ? @{ $server->{account}->{screen_msg_regex} }
  99             : $server->{account}->{screen_msg_regex} )
 100         {
 101             $value =~ s/$regex->{find}/$regex->{replace}/g;
 102         }
 103     }
 104
 105     return (defined($value) && $value) ? add_field($fid, $value) : '';
 106 }
 107
 108 #
 109 # add_count()  produce fixed four-character count field,
 110 # or a string of four spaces if the count is invalid for some
 111 # reason
 112 #
 113 sub add_count {
 114     my ($label, $count) = @_;
 115
 116     # If the field is unsupported, it will be undef, return blanks
 117     # as per the spec.
 118     if (!defined($count)) {
 119                 return ' ' x 4;
 120     }
 121
 122     $count = sprintf("%04d", $count);
 123     if (length($count) != 4) {
 124                 syslog("LOG_WARNING", "handle_patron_info: %s wrong size: '%s'",
 125                $label, $count);
 126                 $count = ' ' x 4;
 127     }
 128     return $count;
 129 }
 130
 131 #
 132 # denied($bool)
 133 # if $bool is false, return true.  This is because SIP statuses
 134 # are inverted:  we report that something has been denied, not that
 135 # it's permitted.  For example, 'renewal priv. denied' of 'Y' means
 136 # that the user's not permitted to renew.  I assume that the ILS has
 137 # real positive tests.
 138 #
 139 sub denied {
 140     my $bool = shift;
 141     return boolspace(!$bool);
 142 }
 143
 144 sub sipbool {
 145     my $bool = shift;
 146     return $bool ? 'Y' : 'N';
 147 }
 148
 149 #
 150 # boolspace: ' ' is false, 'Y' is true. (don't ask)
 151 #
 152 sub boolspace {
 153     my $bool = shift;
 154     return $bool ? 'Y' : ' ';
 155 }
 156
 157
 158 # read_SIP_packet($file)
 159 #
 160 # Read a packet from $file, using the correct record separator
 161 #
 162 sub read_SIP_packet {
 163     my $record;
 164     my $fh = shift or syslog("LOG_ERR", "read_SIP_packet: no filehandle argument!");
 165     my $len1 = 999;
 166
 167     # local $/ = "\r";      # don't need any of these here.  use whatever the prevailing $/ is.
 168     local $/ = "\015";    # proper SPEC: (octal) \015 = (hex) x0D = (dec) 13 = (ascii) carriage return
 169     {    # adapted from http://perldoc.perl.org/5.8.8/functions/readline.html
 170             undef $!;
 171             $record = readline($fh);
 172             if ( defined($record) ) {
 173                 while ( chomp($record) ) { 1; }
 174                 $len1 = length($record);
 175                 syslog( "LOG_DEBUG", "read_SIP_packet, INPUT MSG: '$record'" );
 176                 $record =~ s/^\s*[^A-z0-9]+//s; # Every line must start with a "real" character.  Not whitespace, control chars, etc.
 177                 $record =~ s/[^A-z0-9]+$//s;    # Same for the end.  Note this catches the problem some clients have sending empty fields at the end, like |||
 178                 $record =~ s/\015?\012//g;      # Extra line breaks must die
 179                 $record =~ s/\015?\012//s;      # Extra line breaks must die
 180                 $record =~ s/\015*\012*$//s;    # treat as one line to include the extra linebreaks we are trying to remove!
 181                 while ( chomp($record) ) { 1; }
 182
 183                 $record and last;    # success
 184             }
 185     }
 186     if ($record) {
 187         my $len2 = length($record);
 188         syslog("LOG_INFO", "read_SIP_packet, INPUT MSG: '$record'") if $record;
 189         ($len1 != $len2) and syslog("LOG_DEBUG", "read_SIP_packet, trimmed %s character(s) (after chomps).", $len1-$len2);
 190     } else {
 191         syslog("LOG_WARNING", "read_SIP_packet input %s, end of input.", (defined($record) ? "empty ($record)" : 'undefined'));
 192     }
 193     #
 194     # Cen-Tec self-check terminals transmit '\r\n' line terminators.
 195     # This is actually very hard to deal with in perl in a reasonable
 196     # since every OTHER piece of hardware out there gets the protocol
 197     # right.
 198     #
 199     # The incorrect line terminator presents as a \r at the end of the
 200     # first record, and then a \n at the BEGINNING of the next record.
 201     # So, the simplest thing to do is just throw away a leading newline
 202     # on the input.
 203     #
 204     # This is now handled by the vigorous cleansing above.
 205     # syslog("LOG_INFO", encode_utf8("INPUT MSG: '$record'")) if $record;
 206     syslog("LOG_INFO", "INPUT MSG: '$record'") if $record;
 207     return $record;
 208 }
 209
 210 #
 211 # write_msg($msg, $file)
 212 #
 213 # Send $msg to the SC.  If error detection is active, then
 214 # add the sequence number (if $seqno is non-zero) and checksum
 215 # to the message, and save the whole thing as $last_response
 216 #
 217 # If $file is set, then it's a file handle: write to it, otherwise
 218 # just write to the default destination.
 219 #
 220
 221 sub write_msg {
 222     my ($self, $msg, $file, $terminator, $encoding) = @_;
 223
 224     $terminator ||= q{};
 225     $terminator = ( $terminator eq 'CR' ) ? $CR : $CRLF;
 226
 227     $msg = encode($encoding, $msg) if ( $encoding );
 228
 229     my $cksum;
 230
 231     # $msg = encode_utf8($msg);
 232     if ($error_detection) {
 233         if (defined($self->{seqno})) {
 234             $msg .= 'AY' . $self->{seqno};
 235         }
 236         $msg .= 'AZ';
 237         $cksum = checksum($msg);
 238         $msg .= sprintf('%04.4X', $cksum);
 239     }
 240
 241
 242     if ($file) {
 243         $file->autoflush(1);
 244         print $file $msg, $terminator;
 245     } else {
 246         STDOUT->autoflush(1);
 247         print $msg, $terminator;
 248         syslog("LOG_INFO", "OUTPUT MSG: '$msg'");
 249     }
 250
 251     $last_response = $msg;
 252 }
 253
 254 1;