Siproxd - a masquerading SIP Proxy Server
OVERVIEW
Siproxd is a proxy/masquerading daemon for the SIP protocol. It handles registrations of SIP clients on a private IP network and performs rewriting of the SIP message bodies to make SIP connections work via an masquerading firewall (NAT). It allows SIP software clients (like kphone, linphone) or SIP hardware clients (Voice over IP phones which are SIP-compatible, such as those from Cisco, Grandstream or Snom) to work behind an IP masquerading firewall or NAT router.
SIP (Session Initiation Protocol, RFC3261) is the protocol of
choice for most VoIP (Voice over IP) phones to initiate
communication. By itself, SIP does not work via masquerading
firewalls as the transfered data contains IP addresses and
port numbers. There do exist other solutions to traverse NAT existing
(like STUN, or SIP aware NAT routers), but such a solutions has its
disadvantages or may not be applicable to a given situation.
Siproxd does not aim to be a replacement for these solutions,
however in some situations siproxd may bring advantages.
PREREQUISITES
Siproxd runs on a variety of Unix derivates. Currently known to work are:- Linux
- FreeBSD
- OpenBSD
- SunOS
- Mac OS X
- pfSense
HOW TO GET STARTED
Either download a ready made package for your favorite distribution (there are quite some around) or do it from scratch:- make sure libosip2 is installed
If your libposip2 libraries are installed in /usr/local/lib, be sure to include this library path to /etc/ld.so.conf - $ ./configure
- $ make
- $ make install
- edit /usr/etc/siproxd.conf according to your situation.
At least configure 'if_inbound' and 'if_outbound'. They must represent the interface names (e.g. on Linux: ppp0, eth1) for the inbound and outbound interface. - edit /usr/etc/siproxd_passwd.cfg if you enable client authentication in siproxd.conf
- start siproxd (siproxd does not require root privileges)
$ siproxd
SENDING A PATCH
If you send a patch, please make the diff using "diff -Naur" and include the version of siproxd you used to patch. This makes it a lot easier for me to merge it.PROBLEM REPORTING
If you encounter problems/crashes and ask for support, please include as much information as possible. Very helpful is a debug log that has been recorded at the time of the misbehavior. Also include the exact versions of the siproxd package and libosip2 that you are using. You should also include your siproxd.conf.The easiest way to generate a debug log is:
- make sure siproxd is not started as daemon.
-> 'daemonize = 0' in the config file. - start siproxd:
$ ./siproxd -d -1 2>debug.log - reproduce the error
- include the file debug.log in your error report.
- edit configuration file:
-> 'daemonize = 1' have siproxd started as daemon
-> 'silence_log' should be set to 1
-> 'debug_level = -1'
-> 'debug_port = 5050' (or any other TCP port you like) - have siproxd started the usual way
- connect from a remote machine and write into a file:
$ netcat <IP_of_siproxd> <port> > debug.log - reproduce the error
- include the file debug.log in your error report.
- start siproxd in the debugger (daemonize set to 0):
$ gdb ./src/siproxd
(gdb) set args -c /path/to/siproxd.conf
(gdb) run - reproduce the crash
- use gdb to print the stack backtrace:
(gdb) info thread
...
(gdb) bt
#0 0x400ec9ee in __select ()
#1 0xbffff6f8 in ?? ()
#2 0x804a5c2 in main (argc=3, argv=0xbffffc54) at siproxd.c:186
#3 0x4005bcb3 in __libc_start_main (main=0x804a30c <main>, argc=3,
argv=0xbffffc54, init=0x8049a08 <_init>, fini=0x804edac <_fini>,
rtld_fini=0x4000a350 <_dl_fini>, stack_end=0xbffffc4c)
at ../sysdeps/generic/libc-start.c:78
(gdb) - copy-paste all the output and include it in your error report.