chan_pjsip: Add support for picking up calls in the configured pickup group.

AST-1363

Review: https://reviewboard.asterisk.org/r/3478/
........

Merged revisions 413117 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@413118 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_pjsip.c

@@ -58,6 +58,8 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/stasis_channels.h"
 #include "asterisk/indications.h"
 #include "asterisk/threadstorage.h"
+#include "asterisk/features_config.h"
+#include "asterisk/pickup.h"
 
 #include "asterisk/res_pjsip.h"
 #include "asterisk/res_pjsip_session.h"
@@ -1967,6 +1969,49 @@ static int chan_pjsip_incoming_request(struct ast_sip_session *session, struct p
 	return 0;
 }
 
+static int call_pickup_incoming_request(struct ast_sip_session *session, pjsip_rx_data *rdata)
+{
+	struct ast_features_pickup_config *pickup_cfg = ast_get_chan_features_pickup_config(session->channel);
+	struct ast_channel *chan;
+
+	if (!pickup_cfg) {
+		ast_log(LOG_ERROR, "Unable to retrieve pickup configuration options. Unable to detect call pickup extension.\n");
+		return 0;
+	}
+
+	if (strcmp(session->exten, pickup_cfg->pickupexten)) {
+		ao2_ref(pickup_cfg, -1);
+		return 0;
+	}
+	ao2_ref(pickup_cfg, -1);
+
+	/* We can't directly use session->channel because the pickup operation will cause a masquerade to occur,
+	 * changing the channel pointer in session to a different channel. To ensure we work on the right channel
+	 * we store a pointer locally before we begin and keep a reference so it remains valid no matter what.
+	 */
+	chan = ast_channel_ref(session->channel);
+	if (ast_pickup_call(chan)) {
+		ast_channel_hangupcause_set(chan, AST_CAUSE_CALL_REJECTED);
+	} else {
+		ast_channel_hangupcause_set(chan, AST_CAUSE_NORMAL_CLEARING);
+	}
+	/* A hangup always occurs because the pickup operation will have either failed resulting in the call
+	 * needing to be hung up OR the pickup operation was a success and the channel we now have is actually
+	 * the channel that was replaced, which should be hung up since it is literally in limbo not connected
+	 * to anything at all.
+	 */
+	ast_hangup(chan);
+	ast_channel_unref(chan);
+
+	return 1;
+}
+
+static struct ast_sip_session_supplement call_pickup_supplement = {
+	.method = "INVITE",
+	.priority = AST_SIP_SUPPLEMENT_PRIORITY_LAST - 1,
+	.incoming_request = call_pickup_incoming_request,
+};
+
 static int pbx_start_incoming_request(struct ast_sip_session *session, pjsip_rx_data *rdata)
 {
 	int res;
@@ -2106,9 +2151,16 @@ static int load_module(void)
 		goto end;
 	}
 
+	if (ast_sip_session_register_supplement(&call_pickup_supplement)) {
+		ast_log(LOG_ERROR, "Unable to register PJSIP call pickup supplement\n");
+		ast_sip_session_unregister_supplement(&chan_pjsip_supplement);
+		goto end;
+	}
+
 	if (ast_sip_session_register_supplement(&pbx_start_supplement)) {
 		ast_log(LOG_ERROR, "Unable to register PJSIP pbx start supplement\n");
 		ast_sip_session_unregister_supplement(&chan_pjsip_supplement);
+		ast_sip_session_unregister_supplement(&call_pickup_supplement);
 		goto end;
 	}
 
@@ -2116,6 +2168,7 @@ static int load_module(void)
 		ast_log(LOG_ERROR, "Unable to register PJSIP ACK supplement\n");
 		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;
 	}
 
@@ -2154,6 +2207,7 @@ static int unload_module(void)
 	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);
+	ast_sip_session_unregister_supplement(&call_pickup_supplement);
 
 	ast_custom_function_unregister(&media_offer_function);
 	ast_custom_function_unregister(&chan_pjsip_dial_contacts_function);

res/res_pjsip_session.c

@@ -43,6 +43,8 @@
 #include "asterisk/sdp_srtp.h"
 #include "asterisk/dsp.h"
 #include "asterisk/acl.h"
+#include "asterisk/features_config.h"
+#include "asterisk/pickup.h"
 
 #define SDP_HANDLER_BUCKETS 11
 
@@ -1349,12 +1351,27 @@ static enum sip_get_destination_result get_destination(struct ast_sip_session *s
 {
 	pjsip_uri *ruri = rdata->msg_info.msg->line.req.uri;
 	pjsip_sip_uri *sip_ruri;
+	struct ast_features_pickup_config *pickup_cfg;
+	const char *pickupexten;
+
 	if (!PJSIP_URI_SCHEME_IS_SIP(ruri) && !PJSIP_URI_SCHEME_IS_SIPS(ruri)) {
 		return SIP_GET_DEST_UNSUPPORTED_URI;
 	}
+
 	sip_ruri = pjsip_uri_get_uri(ruri);
 	ast_copy_pj_str(session->exten, &sip_ruri->user, sizeof(session->exten));
-	if (ast_exists_extension(NULL, session->endpoint->context, session->exten, 1, NULL)) {
+
+	pickup_cfg = ast_get_chan_features_pickup_config(session->channel);
+	if (!pickup_cfg) {
+		ast_log(LOG_ERROR, "Unable to retrieve pickup configuration options. Unable to detect call pickup extension\n");
+		pickupexten = "";
+	} else {
+		pickupexten = ast_strdupa(pickup_cfg->pickupexten);
+		ao2_ref(pickup_cfg, -1);
+	}
+
+	if (!strcmp(session->exten, pickupexten) ||
+		ast_exists_extension(NULL, session->endpoint->context, session->exten, 1, NULL)) {
 		return SIP_GET_DEST_EXTEN_FOUND;
 	}
 	/* XXX In reality, we'll likely have further options so that partial matches