C4/SIP/SIPServer.pm

   1 #!/usr/bin/perl
   2 package C4::SIP::SIPServer;
   3
   4 use strict;
   5 use warnings;
   6 use FindBin qw($Bin);
   7 use lib "$Bin";
   8 use Sys::Syslog qw(syslog);
   9 use Net::Server::PreFork;
  10 use IO::Socket::INET;
  11 use Socket qw(:DEFAULT :crlf);
  12 require UNIVERSAL::require;
  13
  14 use C4::Context;
  15 use C4::SIP::Sip::Constants qw(:all);
  16 use C4::SIP::Sip::Configuration;
  17 use C4::SIP::Sip::Checksum qw(checksum verify_cksum);
  18 use C4::SIP::Sip::MsgType qw( handle login_core );
  19
  20 use base qw(Net::Server::PreFork);
  21
  22 use constant LOG_SIP => "local6"; # Local alias for the logging facility
  23
  24 #
  25 # Main  # not really, since package SIPServer
  26 #
  27 # FIXME: Is this a module or a script?
  28 # A script with no MAIN namespace?
  29 # A module that takes command line args?
  30
  31 # Set interface to 'sip'
  32 C4::Context->interface('sip');
  33
  34 my %transports = (
  35     RAW    => \&raw_transport,
  36     telnet => \&telnet_transport,
  37 );
  38
  39 #
  40 # Read configuration
  41 #
  42 my $config = C4::SIP::Sip::Configuration->new( $ARGV[0] );
  43 my @parms;
  44
  45 #
  46 # Ports to bind
  47 #
  48 foreach my $svc (keys %{$config->{listeners}}) {
  49     push @parms, "port=" . $svc;
  50 }
  51
  52 #
  53 # Logging
  54 #
  55 # Log lines look like this:
  56 # Jun 16 21:21:31 server08 steve_sip[19305]: ILS::Transaction::Checkout performing checkout...
  57 # [  TIMESTAMP  ] [ HOST ] [ IDENT ]  PID  : Message...
  58 #
  59 # The IDENT is determined by config file 'server-params' arguments
  60
  61
  62 #
  63 # Server Management: set parameters for the Net::Server::PreFork
  64 # module.  The module silently ignores parameters that it doesn't
  65 # recognize, and complains about invalid values for parameters
  66 # that it does.
  67 #
  68 if (defined($config->{'server-params'})) {
  69     while (my ($key, $val) = each %{$config->{'server-params'}}) {
  70                 push @parms, $key . '=' . $val;
  71     }
  72 }
  73
  74
  75 #
  76 # This is the main event.
  77 __PACKAGE__ ->run(@parms);
  78
  79 #
  80 # Child
  81 #
  82
  83 # process_request is the callback used by Net::Server to handle
  84 # an incoming connection request.
  85
  86 sub process_request {
  87     my $self = shift;
  88     my $service;
  89     my ($sockaddr, $port, $proto);
  90     my $transport;
  91
  92     $self->{config} = $config;
  93
  94     my $sockname = getsockname(STDIN);
  95
  96     # Check if socket connection is IPv6 before resolving address
  97     my $family = Socket::sockaddr_family($sockname);
  98     if ($family == AF_INET6) {
  99       ($port, $sockaddr) = sockaddr_in6($sockname);
 100       $sockaddr = Socket::inet_ntop(AF_INET6, $sockaddr);
 101     } else {
 102       ($port, $sockaddr) = sockaddr_in($sockname);
 103       $sockaddr = inet_ntoa($sockaddr);
 104     }
 105     $proto = $self->{server}->{client}->NS_proto();
 106
 107     $self->{service} = $config->find_service($sockaddr, $port, $proto);
 108
 109     if (!defined($self->{service})) {
 110                 syslog("LOG_ERR", "process_request: Unknown recognized server connection: %s:%s/%s", $sockaddr, $port, $proto);
 111                 die "process_request: Bad server connection";
 112     }
 113
 114     $transport = $transports{$self->{service}->{transport}};
 115
 116     if (!defined($transport)) {
 117                 syslog("LOG_WARNING", "Unknown transport '%s', dropping", $service->{transport});
 118                 return;
 119     } else {
 120                 &$transport($self);
 121     }
 122     return;
 123 }
 124
 125 #
 126 # Transports
 127 #
 128
 129 sub raw_transport {
 130     my $self = shift;
 131     my $input;
 132     my $service = $self->{service};
 133     # If using Net::Server::PreFork you may already have account set from a previous session
 134     # Ensure you dont
 135     if ($self->{account}) {
 136         delete $self->{account};
 137     }
 138
 139     # Timeout the while loop if we get stuck in it
 140     # In practice it should only iterate once but be prepared
 141     local $SIG{ALRM} = sub { die 'raw transport Timed Out!' };
 142     my $timeout = $self->get_timeout({ transport => 1 });
 143     syslog('LOG_DEBUG', "raw_transport: timeout is $timeout");
 144     alarm $timeout;
 145     while (!$self->{account}) {
 146         $input = read_request();
 147         if (!$input) {
 148             # EOF on the socket
 149             syslog("LOG_INFO", "raw_transport: shutting down: EOF during login");
 150             return;
 151         }
 152         $input =~ s/[\r\n]+$//sm; # Strip off trailing line terminator(s)
 153         my $reg = qr/^${\(LOGIN)}/;
 154         last if $input !~ $reg ||
 155             C4::SIP::Sip::MsgType::handle($input, $self, LOGIN);
 156     }
 157     alarm 0;
 158
 159     syslog("LOG_DEBUG", "raw_transport: uname/inst: '%s/%s'",
 160         $self->{account}->{id},
 161         $self->{account}->{institution});
 162     if (! $self->{account}->{id}) {
 163         syslog("LOG_ERR","Login failed shutting down");
 164         return;
 165     }
 166
 167     $self->sip_protocol_loop();
 168     syslog("LOG_INFO", "raw_transport: shutting down");
 169     return;
 170 }
 171
 172 sub get_clean_string {
 173         my $string = shift;
 174         if (defined $string) {
 175                 syslog("LOG_DEBUG", "get_clean_string  pre-clean(length %s): %s", length($string), $string);
 176                 chomp($string);
 177                 $string =~ s/^[^A-z0-9]+//;
 178                 $string =~ s/[^A-z0-9]+$//;
 179                 syslog("LOG_DEBUG", "get_clean_string post-clean(length %s): %s", length($string), $string);
 180         } else {
 181                 syslog("LOG_INFO", "get_clean_string called on undefined");
 182         }
 183         return $string;
 184 }
 185
 186 sub get_clean_input {
 187         local $/ = "\012";
 188         my $in = <STDIN>;
 189         $in = get_clean_string($in);
 190         while (my $extra = <STDIN>){
 191                 syslog("LOG_ERR", "get_clean_input got extra lines: %s", $extra);
 192         }
 193         return $in;
 194 }
 195
 196 sub telnet_transport {
 197     my $self = shift;
 198     my ($uid, $pwd);
 199     my $strikes = 3;
 200     my $account = undef;
 201     my $input;
 202     my $config  = $self->{config};
 203     my $timeout = $self->get_timeout({ transport => 1 });
 204     syslog("LOG_DEBUG", "telnet_transport: timeout is $timeout");
 205
 206     eval {
 207         local $SIG{ALRM} = sub { die "telnet_transport: Timed Out ($timeout seconds)!\n"; };
 208         local $| = 1;                   # Unbuffered output
 209         $/ = "\015";            # Internet Record Separator (lax version)
 210     # Until the terminal has logged in, we don't trust it
 211     # so use a timeout to protect ourselves from hanging.
 212
 213         while ($strikes--) {
 214             print "login: ";
 215                 alarm $timeout;
 216                 # $uid = &get_clean_input;
 217                 $uid = <STDIN>;
 218             print "password: ";
 219             # $pwd = &get_clean_input || '';
 220                 $pwd = <STDIN>;
 221                 alarm 0;
 222
 223                 syslog("LOG_DEBUG", "telnet_transport 1: uid length %s, pwd length %s", length($uid), length($pwd));
 224                 $uid = get_clean_string ($uid);
 225                 $pwd = get_clean_string ($pwd);
 226                 syslog("LOG_DEBUG", "telnet_transport 2: uid length %s, pwd length %s", length($uid), length($pwd));
 227
 228             if (exists ($config->{accounts}->{$uid})
 229                 && ($pwd eq $config->{accounts}->{$uid}->{password})) {
 230                         $account = $config->{accounts}->{$uid};
 231                         if ( C4::SIP::Sip::MsgType::login_core($self,$uid,$pwd) ) {
 232                 last;
 233             }
 234             }
 235                 syslog("LOG_WARNING", "Invalid login attempt: '%s'", ($uid||''));
 236                 print("Invalid login$CRLF");
 237         }
 238     }; # End of eval
 239
 240     if ($@) {
 241                 syslog("LOG_ERR", "telnet_transport: Login timed out");
 242                 die "Telnet Login Timed out";
 243     } elsif (!defined($account)) {
 244                 syslog("LOG_ERR", "telnet_transport: Login Failed");
 245                 die "Login Failure";
 246     } else {
 247                 print "Login OK.  Initiating SIP$CRLF";
 248     }
 249
 250     $self->{account} = $account;
 251     syslog("LOG_DEBUG", "telnet_transport: uname/inst: '%s/%s'", $account->{id}, $account->{institution});
 252     $self->sip_protocol_loop();
 253     syslog("LOG_INFO", "telnet_transport: shutting down");
 254     return;
 255 }
 256
 257 #
 258 # The terminal has logged in, using either the SIP login process
 259 # over a raw socket, or via the pseudo-unix login provided by the
 260 # telnet transport.  From that point on, both the raw and the telnet
 261 # processes are the same:
 262 sub sip_protocol_loop {
 263     my $self = shift;
 264     my $service = $self->{service};
 265     my $config  = $self->{config};
 266     my $timeout = $self->get_timeout({ client => 1 });
 267
 268     # The spec says the first message will be:
 269     #     SIP v1: SC_STATUS
 270     #     SIP v2: LOGIN (or SC_STATUS via telnet?)
 271     # But it might be SC_REQUEST_RESEND.  As long as we get
 272     # SC_REQUEST_RESEND, we keep waiting.
 273
 274     # Comprise reports that no other ILS actually enforces this
 275     # constraint, so we'll relax about it too.
 276     # Using the SIP "raw" login process, rather than telnet,
 277     # requires the LOGIN message and forces SIP 2.00.  In that
 278     # case, the LOGIN message has already been processed (above).
 279
 280     # In short, we'll take any valid message here.
 281     eval {
 282         local $SIG{ALRM} = sub {
 283             syslog( 'LOG_DEBUG', 'Inactive: timed out' );
 284             die "Timed Out!\n";
 285         };
 286         my $previous_alarm = alarm($timeout);
 287
 288         while ( my $inputbuf = read_request() ) {
 289             if ( !defined $inputbuf ) {
 290                 return;    #EOF
 291             }
 292             alarm($timeout);
 293
 294             unless ($inputbuf) {
 295                 syslog( "LOG_ERR", "sip_protocol_loop: empty input skipped" );
 296                 print("96$CR");
 297                 next;
 298             }
 299
 300             my $status = C4::SIP::Sip::MsgType::handle( $inputbuf, $self, q{} );
 301             if ( !$status ) {
 302                 syslog(
 303                     "LOG_ERR",
 304                     "sip_protocol_loop: failed to handle %s",
 305                     substr( $inputbuf, 0, 2 )
 306                 );
 307             }
 308             next if $status eq REQUEST_ACS_RESEND;
 309         }
 310         alarm($previous_alarm);
 311         return;
 312     };
 313     if ( $@ =~ m/timed out/i ) {
 314         return;
 315     }
 316     return;
 317 }
 318
 319 sub read_request {
 320       my $raw_length;
 321       local $/ = "\015";
 322
 323     # proper SPEC: (octal) \015 = (hex) x0D = (dec) 13 = (ascii) carriage return
 324       my $buffer = <STDIN>;
 325       if ( defined $buffer ) {
 326           STDIN->flush();    # clear an extra linefeed
 327           chomp $buffer;
 328           $raw_length = length $buffer;
 329           $buffer =~ s/^\s*[^A-z0-9]+//s;
 330 # Every line must start with a "real" character.  Not whitespace, control chars, etc.
 331           $buffer =~ s/[^A-z0-9]+$//s;
 332
 333 # Same for the end.  Note this catches the problem some clients have sending empty fields at the end, like |||
 334           $buffer =~ s/\015?\012//g;    # Extra line breaks must die
 335           $buffer =~ s/\015?\012//s;    # Extra line breaks must die
 336           $buffer =~ s/\015*\012*$//s;
 337
 338     # treat as one line to include the extra linebreaks we are trying to remove!
 339       }
 340       else {
 341           syslog( 'LOG_DEBUG', 'EOF returned on read' );
 342           return;
 343       }
 344       my $len = length $buffer;
 345       if ( $len != $raw_length ) {
 346           my $trim = $raw_length - $len;
 347           syslog( 'LOG_DEBUG', "read_request trimmed $trim character(s) " );
 348       }
 349
 350       syslog( 'LOG_INFO', "INPUT MSG: '$buffer'" );
 351       return $buffer;
 352 }
 353
 354 # $server->get_timeout({ $type => 1, fallback => $fallback });
 355 #     where $type is transport | client | policy
 356 #
 357 # Centralizes all timeout logic.
 358 # Transport refers to login process, client to active connections.
 359 # Policy timeout is transaction timeout (used in ACS status message).
 360 #
 361 # Fallback is optional. If you do not pass transport, client or policy,
 362 # you will get fallback or hardcoded default.
 363
 364 sub get_timeout {
 365     my ( $server, $params ) = @_;
 366     my $fallback = $params->{fallback} || 30;
 367     my $service = $server->{service} // {};
 368     my $config = $server->{config} // {};
 369
 370     if( $params->{transport} ||
 371         ( $params->{client} && !exists $service->{client_timeout} )) {
 372         # We do not allow zero values here.
 373         # Note: config/timeout seems to be deprecated.
 374         return $service->{timeout} || $config->{timeout} || $fallback;
 375
 376     } elsif( $params->{client} ) {
 377         # We know that client_timeout exists now.
 378         # We do allow zero values here to indicate no timeout.
 379         return 0 if $service->{client_timeout} =~ /^0+$|\D/;
 380         return $service->{client_timeout};
 381
 382     } elsif( $params->{policy} ) {
 383         my $policy = $server->{policy} // {};
 384         my $rv = sprintf( "%03d", $policy->{timeout} // 0 );
 385         if( length($rv) != 3 ) {
 386             syslog( "LOG_ERR", "Policy timeout has wrong size: '%s'", $rv );
 387             return '000';
 388         }
 389         return $rv;
 390
 391     } else {
 392         return $fallback;
 393     }
 394 }
 395
 396 1;
 397
 398 __END__