* Following the example of the PJSIP channel driver, the channel
  technology specific documentation has been moved to the respective
  channel drivers that provide that functionality. This has the benefit
  of locating the documentation of items with those modules that provide
  it.

* Examples of using the CHANNEL function for both standard items as well
  as for PJSIP have been added.

* The 'max_forwards' standard item has been documented.

Change-Id: Ifaa79a232c8ac99cf8da6ef6cc7815d398b1b79b

Errors during startup result in an exit.  These error branches should be
calling ast_run_atexit(0) to ensure mandatory cleanup is run.

ASTERISK-26267 #close

Change-Id: If226f2326ae2df7add20040696132214cf2bb680

When compact_headers was set, we were sending a zero-length header name
for PAI and RPID because we always forced the short header name length
to 0.  We did this because we cloned the header from "From" and wanted
to clear "f" from the sname.  By cloning however, we bypass pjproject's
automatic logic that sets sname to name if there's no compact form of
the header, which there isn't for PAI and RPID.  So now we force sname
to be the same as name right after we set name.

res_pjsip_diversion needed the same treatment for the Diversion header.

ASTERISK-26241 #close

Change-Id: I633ec139630cd83809aae00336cee4a10077e467

When a call forward attempt is made from a Queue member, the current
code will hang up the forwarding channel in an off-nominal condition
prior to raising the Stasis events informing the rest of Asterisk that
the call was forwarded. This will result in a slew of dreaded FRACKs,
most likely leading to a crash.

This patch modifies the code such that we don't hang up the forwarding
channel even in an off-nominal condition until we've safely raised the
Stasis messages.

ASTERISK-25797 #close

Change-Id: Ife5abed351691fd79105321636eaa8ea8dcdba38

If debug was specified in the global configuration but left blank,
the logger would treat it as a wildcard and log all hosts.  If
default_from_user was empty, a crash would result.

The global apply handler now checks for empty strings.

ASTERISK-26239 #close
ASTERISK-26238 #close

Change-Id: Ie75727f5cd5808845d92cc81f5713842fb203336

* Eliminated RAII_VAR() usage in
ast_sip_persistent_endpoint_update_state().

* Added a missing allocation failure check to
persistent_endpoint_find_or_create().

* Made persistent_endpoint_find_or_create() create the new object without
a lock as it isn't needed.

* Cleaned up some ao2 container allocation idioms.

* Reordered res_pjsip_mwi.c load_module() and unload_module()

Change-Id: If8ce88fbd82a0c72a37a2388f74f77237a6a36a8

* Eliminated most RAII_VAR() usage.

* Added several missing allocation failure checks.

* Made ast_sip_for_each_contact() allocate the wrapper ao2 object without
a lock as it is not needed.

Change-Id: Ie20913365156c95dd79e5d471cfd25e99ae880bc

Make it clear that we're talking about device state hints and add
an entry to the sample config.

Change-Id: Iaef58ffb960191a21b713e8e0b51ce1fcd47e433

* The high water check in ast_taskprocessor_alert_set_levels() would
trigger immediately if the new high water level is zero and the queue was
empty.

* The high water check in taskprocessor_push() was off by one.

Change-Id: I687729fb4efa6a0ba38ec9c1c133c4d407bc3d5d

The named aor lock was always being locked for writes so a rwlock adds no
benefit and may be slower because rwlocks are biased toward read locking.

Change-Id: I8c5c2c780eb30ce5441832257beeb3506fd12b28

Change-Id: I932ab2cea845e534d9ff318035b6de39972d3b28

The non-module libs libasteriskssl.dylib and libasteriskpj.dylib have
long been missing the AST_NOT_MODULE compile flag. This was mostly
okay, until a recent fix to improve compiler warnings when the
AST_MODULE_SELF_SYM is missing broke the build on OS X/macOS/whatever
they are calling it these days.

Change-Id: I2cb51c890824f001280a5114f2e775f97c163516

A new identify_by option was added recently, auth_username. However, this
setting was not added as an allowable choice in the database enumeration
value.

This patch updates the current enumeration, adding in the new setting.

ASTERISK-26268 #close

Change-Id: Ib4788e8485e4cd40172ec0abbf5810a147ab8bf8

A patch made to the master branch (Now the 14 branch) inadvertently made
libsrtp a required dependency in order to compile Asterisk.  Rather than
create dummy defines to substitute for the defines supplied by libsrtp
when libsrtp is not available, most of the code in sdp_srtp.c is moved
into res_srtp.c.  This gets more code out of Asterisk's core that isn't
used when SRTP is not available.  This also makes another inadvertent
required dependency on libsrtp by Asterisk's core unlikely.

ASTERISK-26253 #close
Reported by: Ben Merrills

Change-Id: I0a46cde81501c0405399c2588633ae32706d1ee7

If both channels which should be masqueraded
are in the same serializer:
1st channel will be locked waiting condition 'complete'
2nd channel will be locked waiting condition 'suspended'

On heavy load system a chance that both channels will be in
the same serializer 'pjsip/distibutor' is very high.

To reproduce compile res_pjsip/pjsip_distributor.c with
DISTRIBUTOR_POOL_SIZE=1

Steps to reproduce:
1. Party A calls Party B (bridged call 'AB')
2. Party B places Party A on hold
3. Party B calls Voicemail app (non-bridged call 'BV')
4. Party B attended transfers Party A to voicemail using REFER.
5. When asterisk masquerades calls 'AB' and 'BV',
   a deadlock is happened.

This patch adds a suspension indicator to the taskprocessor.
When a session suspends/unsuspends the serializer
it sets the indicator to the appropriate state.
The session checks the suspension indicator before
suspend the serializer.

ASTERISK-26145 #close

Change-Id: Iaaebee60013a58c942ba47b1b4930a63e686663b

The extensions table defined two columns (id and priority) as primary key
autoincrement columns. However only one is allowed when defining the primary
key.

This patch removes the autoincrement attribute from the priority column since
it does not need to be as such and really should not have been on there in the
first place.

This patch also removes 'context', 'exten', and 'priority' from the primary key
index and creates a new combined unique contraint index on them.

ASTERISK-26183 #close

Change-Id: Ib9c712c612a4d7ec1edb0dcb77f1bae0905a470b

libunbound at version 1.4.20 (which CentOS still uses) declared all
of their string function parameters as as 'char *'.  1.4.21 changed
them all to 'const char *'.  Thankfully 1.4.21 also introduced the
UNBOUND_VERSION_MAJOR define so configure now checks for that and
sets HAVE_UNBOUND_CONST_PARAMS.  res_resolver_unbound then checks
that and casts away the 'const' if it's not set.

Tested compile and testsuite on CentOS6 (1.4.20), Ubuntu14 (1.4.22) and
Fedora24 (1.5.4).  There are a few failing tests to be addressed though.

ASTERISK-26283 #close

Change-Id: Ib708b19b706c5d0ba7b7d5473e6df339d9ae4148

This patch adds a new PJSIP specific dialplan function,
PJSIP_SEND_SESSION_REFRESH. When invoked on a PJSIP channel, the media
session will be refreshed via either an UPDATE or re-INVITE request.
When used in conjunction with the PJSIP_MEDIA_OFFER dialplan function,
the formats in use on a PJSIP channel can be re-negotiated and changed
dynamically after call setup.

ASTERISK-26277 #close

Change-Id: Ib98fe09ba889aafe26d58d32f0fd1323f8fd9b1b
(cherry picked from commit eec60dd7)

When an RTCP packet is sent or received, res_rtp_asterisk generates a
Stasis event that contains the RTCP report as well as the local and
remote addresses that the report pertains to.

The addresses are determined using ast_find_ourip(). For the local
address, this will typically result in a lookup of the hostname of the
server, and then a DNS lookup of that hostname. If you do not have the
host in /etc/hosts, then this results in a full DNS lookup, which can
potentially block for some time.

This is especially problematic when performing RTCP reads, since those
are done on the same thread responsible for reading and writing media.

This patch addresses the issue by performing a lookup of the local
address when RTCP is allocated. We then use this cached local address
for the Stasis events when necessary.

ASTERISK-26280 #close
Reported by Mark Michelson

Change-Id: I3dd61882c2e57036f09f0c390cf38f7c87e9b556