chan_pjsip: Add 'pjsip show channelstats'

Added the ability to show channel statistics to chan_pjsip (cli_functions.c)

Moved the existing 'pjsip show channel(s)' functionality from
pjsip_configuration to cli_functions.c.  The stats needed chan_pjsip's
private header so it made sense to move the existing channel commands as well.

Now using stasis_cache_dump to get the channel snapshots rather than retrieving
all endpoints, then getting each one's channel snapshots.  Much more efficient.

Change-Id: I03b114522126d27434030b285bf6d531ddd79869

CHANGES

@@ -8,6 +8,14 @@
 ===
 ==============================================================================
 
+------------------------------------------------------------------------------
+--- Functionality changes from Asterisk 13.8.0 to Asterisk 13.9.0 ------------
+------------------------------------------------------------------------------
+
+chan_pjsip
+------------------
+ * Added 'pjsip show channelstats' CLI command.
+
 ------------------------------------------------------------------------------
 --- Functionality changes from Asterisk 13.7.0 to Asterisk 13.8.0 ------------
 ------------------------------------------------------------------------------

channels/chan_pjsip.c

@@ -69,6 +69,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 
 #include "pjsip/include/chan_pjsip.h"
 #include "pjsip/include/dialplan_functions.h"
+#include "pjsip/include/cli_functions.h"
 
 AST_THREADSTORAGE(uniqueid_threadbuf);
 #define UNIQUEID_BUFSIZE 256
@@ -2419,6 +2420,15 @@ static int load_module(void)
 		goto end;
 	}
 
+	if (pjsip_channel_cli_register()) {
+		ast_log(LOG_ERROR, "Unable to register PJSIP Channel CLI\n");
+		ast_sip_session_unregister_supplement(&chan_pjsip_ack_supplement);
+		ast_sip_session_unregister_supplement(&pbx_start_supplement);
+		ast_sip_session_unregister_supplement(&chan_pjsip_supplement);
+		ast_sip_session_unregister_supplement(&call_pickup_supplement);
+		goto end;
+	}
+
 	/* since endpoints are loaded before the channel driver their device
 	   states get set to 'invalid', so they need to be updated */
 	if ((endpoints = ast_sip_get_endpoints())) {
@@ -2445,6 +2455,8 @@ static int unload_module(void)
 	ao2_cleanup(pjsip_uids_onhold);
 	pjsip_uids_onhold = NULL;
 
+	pjsip_channel_cli_unregister();
+
 	ast_sip_session_unregister_supplement(&chan_pjsip_supplement);
 	ast_sip_session_unregister_supplement(&pbx_start_supplement);
 	ast_sip_session_unregister_supplement(&chan_pjsip_ack_supplement);