FS-11557: [mod_sofia] add support for RFC 7989 Session-ID header

(enable with sofia profile param rfc-7989=true)

FS-11557 [mod_sofia, mod_conference, core] Add support for re-INVITE when setting Session-ID in conference after call has been answered.

FS-11557 [mod_conference] Missed a spot where APP_SESSION_ID needed to be set.

FS-11557: set session id for outbound (initial requests)

FS-11557: [mod_sofia] rename vars and functions "session id" -> "session uuid" to reflect the real meaning for rfc7989.

FS-11557: fix bug - colliding chan var names (session_id)

FS-11557: check nil session uuid

FS-11557 : replace CS_NEW with CS_INIT for when originating calls, generate new uuid.

FS-11557: handle inbound (UAS mode, one leg)

FS-11557: generic param handling and filter via new sip profile option "rfc-7989-filter", eg:
<param name="rfc-7989-filter" value="logme, sec-agree, privacy" />

FS-11557: renamed chan vars (reflect meaning only for RFC7989)

FS-11557: fallback to RFC7329 - "old" Session-ID

FS-11557: distinguish between request and replies when we read the header
(to provide compatibility with old RFC7329 - section 11 of RFC7989)
FS-11557: change more vars/consts names

FS-11557: move compat flag on the channel.

FS-11557: add Session-ID header in REFER

FS-11557: needs extra condition on received initial request

FS-11557: handle NOTIFY

FS-11557: support answer() in dialplan - it was sending back a 200 OK with Session-ID invalid, eg: A=NIL;B=X

FS-11557: add Session-ID for NOTIFY (more cases)

FS-11557: handle reply to SIP INFO (add Session-ID header)

FS-11557: handle case of BYE after REFER, when the channel is destroyed already (save the uuid on sofia_private)

FS-11557: handle more SIP reply cases (eg: 202 Accepted , more negative replies)

FS-11557: handle ACK (UAS role)

FS-11557: added "rfc-7989-force-old" profile param - to enforce old rfc7329 for the UAC role. default off.
enabled with "<param name="rfc-7989-force-old" value="true" />".

FS-11557: fallback to rfc7329 fixes.

FS-11557: set flag CF_RFC7329_COMPAT on partner channel where needed

FS-11557: fix crash (mod_conference)

src/include/switch_types.h

@@ -225,6 +225,10 @@ SWITCH_BEGIN_EXTERN_C
 #define SWITCH_EXEC_AFTER_BRIDGE_APP_VARIABLE "exec_after_bridge_app"
 #define SWITCH_EXEC_AFTER_BRIDGE_ARG_VARIABLE "exec_after_bridge_arg"
 #define SWITCH_MAX_FORWARDS_VARIABLE "max_forwards"
+#define SWITCH_RFC7989_SESSION_ID_VARIABLE "session_uuid"
+#define SWITCH_RFC7989_REMOTE_SESSION_ID_VARIABLE "remote_session_uuid"
+#define SWITCH_RFC7989_APP_SESSION_ID_VARIABLE "app_session_uuid"
+#define SWITCH_RFC7989_GENERIC_PARAM_VARIABLE "generic_param_session_uuid"
 #define SWITCH_MAX_SESSION_TRANSFERS_VARIABLE "max_session_transfers"
 #define SWITCH_DISABLE_APP_LOG_VARIABLE "disable_app_log"
 #define SWITCH_SPEECH_KEY "speech"
@@ -1159,6 +1163,7 @@ typedef enum {
 	SWITCH_MESSAGE_RING_EVENT,
 	SWITCH_MESSAGE_RESAMPLE_EVENT,
 	SWITCH_MESSAGE_HEARTBEAT_EVENT,
+	SWITCH_MESSAGE_INDICATE_SESSION_ID,
 	SWITCH_MESSAGE_INVALID
 } switch_core_session_message_types_t;
 
@@ -1607,6 +1612,7 @@ typedef enum {
 	CF_ARRANGED_BRIDGE,
 	CF_STATE_REPEAT,
 	CF_WANT_DTLSv1_2,
+	CF_RFC7329_COMPAT,
 	/* WARNING: DO NOT ADD ANY FLAGS BELOW THIS LINE */
 	/* IF YOU ADD NEW ONES CHECK IF THEY SHOULD PERSIST OR ZERO THEM IN switch_core_session.c switch_core_session_request_xml() */
 	CF_FLAG_MAX

src/mod/applications/mod_conference/mod_conference.c

@@ -1911,8 +1911,8 @@ SWITCH_STANDARD_APP(conference_function)
 
 	switch_channel_set_flag(channel, CF_CONFERENCE);
 
-	if (switch_channel_answer(channel) != SWITCH_STATUS_SUCCESS) {
-		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Channel answer failed.\n");
+	if (switch_channel_pre_answer(channel) != SWITCH_STATUS_SUCCESS) {
+		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Channel pre answer failed.\n");
 		goto end;
 	}
 
@@ -2060,6 +2060,7 @@ SWITCH_STANDARD_APP(conference_function)
 		locked = 0;
 
 		switch_channel_set_variable(channel, "conference_name", conference->name);
+		switch_channel_set_variable(channel, SWITCH_RFC7989_APP_SESSION_ID_VARIABLE, conference->uuid_str);
 
 		/* Set the minimum number of members (once you go above it you cannot go below it) */
 		conference->min = 2;
@@ -2144,6 +2145,7 @@ SWITCH_STANDARD_APP(conference_function)
 			}
 
 			switch_channel_set_variable(channel, "conference_name", conference->name);
+			switch_channel_set_variable(channel, SWITCH_RFC7989_APP_SESSION_ID_VARIABLE, conference->uuid_str);
 
 			/* Set MOH from variable if not set */
 			if (zstr(conference->moh_sound)) {
@@ -2210,6 +2212,7 @@ SWITCH_STANDARD_APP(conference_function)
 			switch_channel_api_on(channel, "api_on_conference_create");
 		} else {				/* setup user variable */
 			switch_channel_set_variable(channel, "conference_name", conference->name);
+			switch_channel_set_variable(channel, SWITCH_RFC7989_APP_SESSION_ID_VARIABLE, conference->uuid_str);
 			rl++;
 		}
 
@@ -2223,6 +2226,12 @@ SWITCH_STANDARD_APP(conference_function)
 			mdpin = conference->mpin;
 		}
 
+		/* Tell the channel we have a new Session-ID */
+		msg.from = __FILE__;
+		msg.message_id = SWITCH_MESSAGE_INDICATE_SESSION_ID;
+		switch_core_session_receive_message(session, &msg);
+
+		switch_channel_answer(channel);
 
 		/* if this is not an outbound call, deal with conference pins */
 		if (enforce_security && (!zstr(dpin) || !zstr(mdpin))) {
@@ -2233,9 +2242,6 @@ SWITCH_STANDARD_APP(conference_function)
 			switch_status_t status = SWITCH_STATUS_SUCCESS;
 			char *supplied_pin_value;
 
-			/* Answer the channel */
-			switch_channel_answer(channel);
-
 			/* look for PIN in channel variable first.  If not present or invalid revert to prompting user */
 			supplied_pin_value = switch_core_strdup(conference->pool, switch_channel_get_variable(channel, "supplied_pin"));
 			if (!zstr(supplied_pin_value)) {

src/mod/endpoints/mod_sofia/mod_sofia.h

@@ -192,6 +192,7 @@ struct sofia_private {
 	int is_call;
 	int is_static;
 	switch_time_t ping_sent;
+	char *rfc7989_uuid;
 };
 
 #define set_param(ptr,val) if (ptr) {free(ptr) ; ptr = NULL;} if (val) {ptr = strdup(val);}
@@ -310,6 +311,8 @@ typedef enum {
 	PFLAG_FIRE_BYE_RESPONSE_EVENTS,
 	PFLAG_AUTO_INVITE_100,
 	PFLAG_UPDATE_REFRESHER,
+	PFLAG_RFC7989_SESSION_ID,
+	PFLAG_RFC7989_FORCE_OLD,
 	PFLAG_AUTH_REQUIRE_USER,
 	PFLAG_AUTH_CALLS_ACL_ONLY,
 	PFLAG_USE_PORT_FOR_ACL_CHECK,
@@ -790,6 +793,7 @@ struct sofia_profile {
 	int bind_attempt_interval;
 	char *proxy_notify_events;
 	char *proxy_info_content_types;
+	char *rfc7989_filter;
 	char *acl_inbound_x_token_header;
 	char *acl_proxy_x_token_header;
 };
@@ -989,6 +993,13 @@ void launch_sofia_profile_thread(sofia_profile_t *profile);
 
 switch_status_t sofia_presence_chat_send(switch_event_t *message_event);
 
+#define RFC7989_SESSION_UUID_LEN 32
+#define RFC7989_SESSION_UUID_NULL "00000000000000000000000000000000"
+
+int sofia_glue_is_valid_session_id(const char *session_id);
+void sofia_glue_store_session_id(switch_core_session_t *session, sofia_profile_t *profile, sip_t const *sip, switch_bool_t is_reply);
+char *sofia_glue_session_id_header(switch_core_session_t *session, sofia_profile_t *profile);
+
 /*
  * \brief Sets the "ep_codec_string" channel variable, parsing r_sdp and taing codec_string in consideration
  * \param channel Current channel