mwolff44 / callweaver

Callweaver is/was an old fork of Asterisk 1.2 from the days when the newer Asterisk 1.4 was still pursuing stability. A number of fixes and improvements were made by a small community of coders.

Today callweaver is unused even by me. I've put it here simply because, to the best of my knowledge, it doesn't exist anywhere else and there is some potentially interesting code to be found in it.

• It contains example use of Steve Underwood's SpanDSP library to implement native FAX send and receive over both RTP (network) and TDM (fixed line telephony) circuits.

• I undertook a major rewrite of the dialplan handling to remove many issues.

• I added auto-backoff and blacklisting to the SIP channel to mitigate the impact of the continuous script-kiddie probing that every exposed SIP server experiences.

• I added IPv6 support to the SIP channel - along with many other changes to make it (slightly?) more conformant to the RFCs.

• I extended printf with format specifiers for network addresses using both the glibc extension hooks and a transparent workaround for other environments.

• I added a C implementation of dynamic strings in include/callweaver/dynstr.h and corelib/dynstr.c (including support for sprinf'ing into them).

• I (ab)used the preprocessor to implement a variant of printf that allows complex formats to be expressed in a user friendly format but which collects the components together into a single format string at compile time. This makes much of the message handling much clearer. e.g.

      cw_dynstr_tprintf(ds_p, 3,
          cw_fmtval("-- General --\n"),
          cw_fmtval("Name: %s\n",           chan->name),
          cw_fmtval("Type: %s\n",           chan->type));
  

  which compiles as

  cw_dynstr_printf("-- General --\nName: %s\nType: %s\n", chan->name, chan->type);
  

• I added a C implementation of dynamic arrays in include/callweaver/dynarray.h that is templated via preprocessor defines so that you can use dynamic arrays of whatever type you choose.

• I added a C implementation of reference counted objects (entities rather than Objects in the modern OOP sense - it's C not C++!) in include/callweaver/object.h that uses atomic ops. This is heavily used throughout callweaver to avoid locking issues arising from the old code design.

I have been known to dust it off occasionally and use it for testing various ideas but since I have neither used SIP nor owned a PC that would take my old TDM cards for many years you should not expect callweaver to be stable or even usable anymore!