Add service maintenance message support

This is the companion commit to libpri r732. Service messages are now supported
for switch types 4ess/5ess. A new option service_message_support has been added
to chan_dahdi.conf and is noted in the sample config file. The service message
support is turned off by default. The current implementation relies on AstDB
to keep track of channel state, which allows the statuses to be preserved
across Asterisk restarts. Below is a description of the storage format.

The state and reason for the service state are in the form <state>:<reason>,
where:
<state> ::= { 'O' }  // 'O' – Out Of Service
<reason> ::= { '0' | '1' | '2' | '3' }, where:
'0' – No reason (backwards compatibility)
'1' – NEAR END
'2' – FAR END
'3' – both NEAR and FAR END

The new CLI commands to handle channel service state are:
pri service disable channel <chan>
pri service enable channel <chan>

Many people contributed to the development of this functionality. Because I
entered at the very end I do not know the exact history. Special thanks to 
all who moved the bug forward one way or another:
cmaj, PCadach, markster, mattf, drmac, MikeJ, serge-v, murf, kanelbullar, Seb7,
tilghman, lmadsen, and especially dhubbard (he answered lots of my questions
and did a large portion of the work)

(closes issue #3450)
Reported by: cmaj



git-svn-id: http://svn.digium.com/svn/asterisk/trunk@188342 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 2 insertions, 0 deletions

diff --git a/configure.ac b/configure.ac
index ac129accc..00220d238 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1404,6 +1404,8 @@ AST_EXT_LIB_CHECK([PRI_PROG_W_CAUSE], [pri], [pri_progress_with_cause], [libpri.
 
 AST_EXT_LIB_CHECK([PRI_INBANDDISCONNECT], [pri], [pri_set_inbanddisconnect], [libpri.h])
 
+AST_EXT_LIB_CHECK([PRI_SERVICE_MESSAGES], [pri], [pri_maintenance_service], [libpri.h])
+
 AST_EXT_LIB_CHECK([RESAMPLE], [resample], [resample_open], [libresample.h], [-lm])
 
 AST_C_COMPILE_CHECK([SPANDSP], [