Add a generic function to set the bridged call PVT unique id string

as a channel variable BRIDGEPVTCALLID

This is important for call tracing in log files and CDRs, so that
the SIP callID can be traced along servers.

The CHANNEL dialplan function won't work here, since the outbound
channel is gone when we need the Call-ID.

Other channel drivers may now implement the same function :-),
but this patch only supports chan_sip.so.

Inspired by (issue #11816)
Reported by: ctooley

Patch by oej



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@99644 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -1676,6 +1676,7 @@ static int sip_transfer(struct ast_channel *ast, const char *dest);
 static int sip_fixup(struct ast_channel *oldchan, struct ast_channel *newchan);
 static int sip_senddigit_begin(struct ast_channel *ast, char digit);
 static int sip_senddigit_end(struct ast_channel *ast, char digit, unsigned int duration);
+static char *sip_get_callid(struct ast_channel *chan);
 
 static int handle_request_do(struct sip_request *req, struct sockaddr_in *sin);
 static int sip_standard_port(struct sip_socket s);
@@ -2036,6 +2037,7 @@ static const struct ast_channel_tech sip_tech = {
 	.early_bridge = ast_rtp_early_bridge,
 	.send_text = sip_sendtext,		/* called with chan locked */
 	.func_channel_read = acf_channel_read,
+	.get_pvt_uniqueid = sip_get_callid,
 };
 
 /*! \brief This version of the sip channel tech has no send_digit_begin
@@ -3238,6 +3240,15 @@ static int sip_sendhtml(struct ast_channel *chan, int subclass, const char *data
 	return 0;
 }
 
+/*! \brief Deliver SIP call ID for the call */
+static char *sip_get_callid(struct ast_channel *chan)
+{
+	struct sip_pvt *p = chan->tech_pvt;
+	if (!p)
+		return "";
+	return ((char *)p->callid);
+}
+
 /*! \brief Send SIP MESSAGE text within a call
 	Called from PBX core sendtext() application */
 static int sip_sendtext(struct ast_channel *ast, const char *text)
@@ -14381,6 +14392,10 @@ static void handle_response_invite(struct sip_pvt *p, int resp, char *rest, stru
 					manager_event(EVENT_FLAG_SYSTEM, "ChannelUpdate",
 						"Channel: %s\r\nChanneltype: %s\r\nUniqueid: %s\r\nSIPcallid: %s\r\nSIPfullcontact: %s\r\nPeername: %s\r\n",
 						p->owner->name, p->owner->uniqueid, "SIP", p->callid, p->fullcontact, p->peername);
+				/* Set bridged channel variable */
+				bridgepeer = ast_bridged_channel(p->owner);
+				if (bridgepeer)
+					pbx_builtin_setvar_helper(bridgepeer, "SIP_BRIDGED_CALLID", p->callid);
 			} else {	/* RE-invite */
 				ast_queue_frame(p->owner, &ast_null_frame);
 			}

include/asterisk/channel.h

@@ -335,6 +335,9 @@ struct ast_channel_tech {
 	
 	/*! \brief Set base channel (agent and local) */
 	int (* set_base_channel)(struct ast_channel *chan, struct ast_channel *base);
+
+	/*! \brief Get the unique identifier for the PVT, i.e. SIP call-ID for SIP */
+	char * (* get_pvt_uniqueid)(struct ast_channel *chan);
 };
 
 struct ast_epoll_data;

main/channel.c

@@ -4222,6 +4222,10 @@ enum ast_bridge_result ast_channel_bridge(struct ast_channel *c0, struct ast_cha
 			pbx_builtin_setvar_helper(c0, "BRIDGEPEER", c1->name);
 		if (!ast_strlen_zero(pbx_builtin_getvar_helper(c1, "BRIDGEPEER")))
 			pbx_builtin_setvar_helper(c1, "BRIDGEPEER", c0->name);
+		if (c0->tech->get_pvt_uniqueid)
+			pbx_builtin_setvar_helper(c1, "BRIDGEPVTCALLID", c0->tech->get_pvt_uniqueid(c0));
+		if (c1->tech->get_pvt_uniqueid)
+			pbx_builtin_setvar_helper(c0, "BRIDGEPVTCALLID", c1->tech->get_pvt_uniqueid(c1));
 		
 		if (c0->tech->bridge &&
 		    (config->timelimit == 0) &&