C4/SIP/SIPServer.pm

   1 #!/usr/bin/perl
   2 package 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 Sip::Constants qw(:all);
  15 use Sip::Configuration;
  16 use Sip::Checksum qw(checksum verify_cksum);
  17 use Sip::MsgType;
  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 = new Sip::Configuration $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 }
 119
 120 #
 121 # Transports
 122 #
 123
 124 sub raw_transport {
 125     my $self = shift;
 126     my ($input);
 127     my $service = $self->{service};
 128
 129     while (!$self->{account}) {
 130     local $SIG{ALRM} = sub { die "raw_transport Timed Out!\n"; };
 131     syslog("LOG_DEBUG", "raw_transport: timeout is %d", $service->{timeout});
 132     $input = Sip::read_SIP_packet(*STDIN);
 133     if (!$input) {
 134         # EOF on the socket
 135         syslog("LOG_INFO", "raw_transport: shutting down: EOF during login");
 136         return;
 137     }
 138     $input =~ s/[\r\n]+$//sm;   # Strip off trailing line terminator(s)
 139     last if Sip::MsgType::handle($input, $self, LOGIN);
 140     }
 141
 142     syslog("LOG_DEBUG", "raw_transport: uname/inst: '%s/%s'",
 143            $self->{account}->{id},
 144            $self->{account}->{institution});
 145
 146     $self->sip_protocol_loop();
 147     syslog("LOG_INFO", "raw_transport: shutting down");
 148 }
 149
 150 sub get_clean_string {
 151         my $string = shift;
 152         if (defined $string) {
 153                 syslog("LOG_DEBUG", "get_clean_string  pre-clean(length %s): %s", length($string), $string);
 154                 chomp($string);
 155                 $string =~ s/^[^A-z0-9]+//;
 156                 $string =~ s/[^A-z0-9]+$//;
 157                 syslog("LOG_DEBUG", "get_clean_string post-clean(length %s): %s", length($string), $string);
 158         } else {
 159                 syslog("LOG_INFO", "get_clean_string called on undefined");
 160         }
 161         return $string;
 162 }
 163
 164 sub get_clean_input {
 165         local $/ = "\012";
 166         my $in = <STDIN>;
 167         $in = get_clean_string($in);
 168         while (my $extra = <STDIN>){
 169                 syslog("LOG_ERR", "get_clean_input got extra lines: %s", $extra);
 170         }
 171         return $in;
 172 }
 173
 174 sub telnet_transport {
 175     my $self = shift;
 176     my ($uid, $pwd);
 177     my $strikes = 3;
 178     my $account = undef;
 179     my $input;
 180     my $config  = $self->{config};
 181         my $timeout = $self->{service}->{timeout} || $config->{timeout} || 30;
 182         syslog("LOG_DEBUG", "telnet_transport: timeout is %s", $timeout);
 183
 184     eval {
 185         local $SIG{ALRM} = sub { die "telnet_transport: Timed Out ($timeout seconds)!\n"; };
 186         local $| = 1;                   # Unbuffered output
 187         $/ = "\015";            # Internet Record Separator (lax version)
 188     # Until the terminal has logged in, we don't trust it
 189     # so use a timeout to protect ourselves from hanging.
 190
 191         while ($strikes--) {
 192             print "login: ";
 193                 alarm $timeout;
 194                 # $uid = &get_clean_input;
 195                 $uid = <STDIN>;
 196             print "password: ";
 197             # $pwd = &get_clean_input || '';
 198                 $pwd = <STDIN>;
 199                 alarm 0;
 200
 201                 syslog("LOG_DEBUG", "telnet_transport 1: uid length %s, pwd length %s", length($uid), length($pwd));
 202                 $uid = get_clean_string ($uid);
 203                 $pwd = get_clean_string ($pwd);
 204                 syslog("LOG_DEBUG", "telnet_transport 2: uid length %s, pwd length %s", length($uid), length($pwd));
 205
 206             if (exists ($config->{accounts}->{$uid})
 207                 && ($pwd eq $config->{accounts}->{$uid}->password())) {
 208                         $account = $config->{accounts}->{$uid};
 209                         Sip::MsgType::login_core($self,$uid,$pwd) and last;
 210             }
 211                 syslog("LOG_WARNING", "Invalid login attempt: '%s'", ($uid||''));
 212                 print("Invalid login$CRLF");
 213         }
 214     }; # End of eval
 215
 216     if ($@) {
 217                 syslog("LOG_ERR", "telnet_transport: Login timed out");
 218                 die "Telnet Login Timed out";
 219     } elsif (!defined($account)) {
 220                 syslog("LOG_ERR", "telnet_transport: Login Failed");
 221                 die "Login Failure";
 222     } else {
 223                 print "Login OK.  Initiating SIP$CRLF";
 224     }
 225
 226     $self->{account} = $account;
 227     syslog("LOG_DEBUG", "telnet_transport: uname/inst: '%s/%s'", $account->{id}, $account->{institution});
 228     $self->sip_protocol_loop();
 229     syslog("LOG_INFO", "telnet_transport: shutting down");
 230 }
 231
 232 #
 233 # The terminal has logged in, using either the SIP login process
 234 # over a raw socket, or via the pseudo-unix login provided by the
 235 # telnet transport.  From that point on, both the raw and the telnet
 236 # processes are the same:
 237 sub sip_protocol_loop {
 238         my $self = shift;
 239         my $service = $self->{service};
 240         my $config  = $self->{config};
 241     my $timeout = $self->{service}->{timeout} || $config->{timeout} || 30;
 242         my $input;
 243
 244     # The spec says the first message will be:
 245         #       SIP v1: SC_STATUS
 246         #       SIP v2: LOGIN (or SC_STATUS via telnet?)
 247     # But it might be SC_REQUEST_RESEND.  As long as we get
 248     # SC_REQUEST_RESEND, we keep waiting.
 249
 250     # Comprise reports that no other ILS actually enforces this
 251     # constraint, so we'll relax about it too.
 252     # Using the SIP "raw" login process, rather than telnet,
 253     # requires the LOGIN message and forces SIP 2.00.  In that
 254         # case, the LOGIN message has already been processed (above).
 255         #
 256         # In short, we'll take any valid message here.
 257         #my $expect = SC_STATUS;
 258     local $SIG{ALRM} = sub { die "SIP Timed Out!\n"; };
 259     my $expect = '';
 260     while (1) {
 261         alarm $timeout;
 262         $input = Sip::read_SIP_packet(*STDIN);
 263         unless ($input) {
 264             return;             # EOF
 265         }
 266                 # begin input hacks ...  a cheap stand in for better Telnet layer
 267                 $input =~ s/^[^A-z0-9]+//s;     # Kill leading bad characters... like Telnet handshakers
 268                 $input =~ s/[^A-z0-9]+$//s;     # Same on the end, should get DOSsy ^M line-endings too.
 269                 while (chomp($input)) {warn "Extra line ending on input";}
 270                 unless ($input) {
 271             syslog("LOG_ERR", "sip_protocol_loop: empty input skipped");
 272             print("96$CR");
 273             next;
 274                 }
 275                 # end cheap input hacks
 276                 my $status = Sip::MsgType::handle($input, $self, $expect);
 277                 if (!$status) {
 278                         syslog("LOG_ERR", "sip_protocol_loop: failed to handle %s",substr($input,0,2));
 279                 }
 280                 next if $status eq REQUEST_ACS_RESEND;
 281                 if ($expect && ($status ne $expect)) {
 282                         # We received a non-"RESEND" that wasn't what we were expecting.
 283                     syslog("LOG_ERR", "sip_protocol_loop: expected %s, received %s, exiting", $expect, $input);
 284                 }
 285                 # We successfully received and processed what we were expecting
 286                 $expect = '';
 287     alarm 0;
 288         }
 289 }
 290
 291 1;
 292 __END__