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