Merge "res_pjsip: Patch for res_pjsip_* module load/reload crash" into 16

include/asterisk/res_pjsip_session.h

@@ -580,9 +580,13 @@ void ast_sip_session_unregister_sdp_handler(struct ast_sip_session_sdp_handler *
  * set channel data based on headers in an incoming message. Similarly,
  * a module could reject an incoming request if desired.
  *
+ * \param module Referenced module(NULL safe)
  * \param supplement The supplement to register
  */
-void ast_sip_session_register_supplement(struct ast_sip_session_supplement *supplement);
+void ast_sip_session_register_supplement_with_module(struct ast_module *module, struct ast_sip_session_supplement *supplement);
+
+#define ast_sip_session_register_supplement(supplement) \
+		ast_sip_session_register_supplement_with_module(AST_MODULE_SELF, supplement)
 
 /*!
  * \brief Unregister a an supplement to SIP session processing
@@ -598,6 +602,13 @@ void ast_sip_session_unregister_supplement(struct ast_sip_session_supplement *su
  */
 int ast_sip_session_add_supplements(struct ast_sip_session *session);
 
+/*!
+ * \brief Remove supplements from a SIP session
+ *
+ * \param session The session to remove
+ */
+void ast_sip_session_remove_supplements(struct ast_sip_session *session);
+
 /*!
  * \brief Alternative for ast_datastore_alloc()
  *

res/res_pjsip/pjsip_message_filter.c

@@ -24,6 +24,7 @@
 #include "asterisk/res_pjsip.h"
 #include "asterisk/res_pjsip_session.h"
 #include "include/res_pjsip_private.h"
+#include "asterisk/module.h"
 
 #define MOD_DATA_RESTRICTIONS "restrictions"
 

res/res_pjsip/pjsip_session.c

@@ -29,22 +29,50 @@
 #include "asterisk/lock.h"
 #include "asterisk/module.h"
 
-
 AST_RWLIST_HEAD_STATIC(session_supplements, ast_sip_session_supplement);
 
-void ast_sip_session_register_supplement(struct ast_sip_session_supplement *supplement)
+/* This structure is used to support module references without
+ * breaking the ABI of the public struct ast_sip_session_supplement. */
+struct private_sip_session_supplement {
+	/*! \brief This will be added to the session_supplements list.
+	 *
+	 * This field must be at offset 0 to enable retrieval of this
+	 * structure from session_supplements.
+	 */
+	struct ast_sip_session_supplement copy;
+	/*! Users of this session supplement will hold a reference to the module. */
+	struct ast_module *module;
+	/*! Pointer to the static variable for unregister comparisons. */
+	struct ast_sip_session_supplement *original;
+};
+
+void ast_sip_session_register_supplement_with_module(struct ast_module *module, struct ast_sip_session_supplement *supplement)
 {
 	struct ast_sip_session_supplement *iter;
+	struct private_sip_session_supplement *priv;
 	int inserted = 0;
 	SCOPED_LOCK(lock, &session_supplements, AST_RWLIST_WRLOCK, AST_RWLIST_UNLOCK);
 
+	ast_assert(supplement != NULL);
+
 	if (!supplement->response_priority) {
 		supplement->response_priority = AST_SIP_SESSION_BEFORE_MEDIA;
 	}
 
+	priv = ast_calloc(1, sizeof(*priv));
+	if (!priv) {
+		/* Really can't do anything here, just assert and return. */
+		ast_assert(priv != NULL);
+		return;
+	}
+
+	priv->copy = *supplement;
+	priv->module = module;
+	priv->original = supplement;
+
 	AST_RWLIST_TRAVERSE_SAFE_BEGIN(&session_supplements, iter, next) {
 		if (iter->priority > supplement->priority) {
-			AST_RWLIST_INSERT_BEFORE_CURRENT(supplement, next);
+			AST_RWLIST_INSERT_BEFORE_CURRENT(&priv->copy, next);
 			inserted = 1;
 			break;
 		}
@@ -52,7 +80,7 @@ void ast_sip_session_register_supplement(struct ast_sip_session_supplement *supp
 	AST_RWLIST_TRAVERSE_SAFE_END;
 
 	if (!inserted) {
-		AST_RWLIST_INSERT_TAIL(&session_supplements, supplement, next);
+		AST_RWLIST_INSERT_TAIL(&session_supplements, &priv->copy, next);
 	}
 }
 
@@ -62,17 +90,20 @@ void ast_sip_session_unregister_supplement(struct ast_sip_session_supplement *su
 	SCOPED_LOCK(lock, &session_supplements, AST_RWLIST_WRLOCK, AST_RWLIST_UNLOCK);
 
 	AST_RWLIST_TRAVERSE_SAFE_BEGIN(&session_supplements, iter, next) {
-		if (supplement == iter) {
+		struct private_sip_session_supplement *priv = (void*)iter;
+
+		if (supplement == priv->original) {
 			AST_RWLIST_REMOVE_CURRENT(next);
+			ast_free(priv);
 			break;
 		}
 	}
 	AST_RWLIST_TRAVERSE_SAFE_END;
 }
 
-static struct ast_sip_session_supplement *supplement_dup(const struct ast_sip_session_supplement *src)
+static struct private_sip_session_supplement *supplement_dup(const struct private_sip_session_supplement *src)
 {
-	struct ast_sip_session_supplement *dst = ast_calloc(1, sizeof(*dst));
+	struct private_sip_session_supplement *dst = ast_calloc(1, sizeof(*dst));
 
 	if (!dst) {
 		return NULL;
@@ -89,13 +120,47 @@ int ast_sip_session_add_supplements(struct ast_sip_session *session)
 	SCOPED_LOCK(lock, &session_supplements, AST_RWLIST_RDLOCK, AST_RWLIST_UNLOCK);
 
 	AST_RWLIST_TRAVERSE(&session_supplements, iter, next) {
-		struct ast_sip_session_supplement *copy = supplement_dup(iter);
+		struct private_sip_session_supplement *dup = supplement_dup((void*)iter);
 
-		if (!copy) {
+		if (!dup) {
 			return -1;
 		}
-		AST_LIST_INSERT_TAIL(&session->supplements, copy, next);
+
+		/* referenced session created. increasing module reference. */
+		ast_module_ref(dup->module);
+
+		AST_LIST_INSERT_TAIL(&session->supplements, &dup->copy, next);
 	}
 
 	return 0;
 }
+
+void ast_sip_session_remove_supplements(struct ast_sip_session *session)
+{
+	struct ast_sip_session_supplement *iter;
+
+	if (!session) {
+		return;
+	}
+
+	/* free the supplements */
+	while ((iter = AST_LIST_REMOVE_HEAD(&session->supplements, next))) {
+		struct private_sip_session_supplement *priv = (void*)iter;
+		if (priv->module) {
+			/* referenced session closed. decreasing module reference. */
+			ast_module_unref(priv->module);
+		}
+
+		ast_free(iter);
+	}
+
+	return;
+}
+
+/* This stub is for ABI compatibility. */
+#undef ast_sip_session_register_supplement
+void ast_sip_session_register_supplement(struct ast_sip_session_supplement *supplement);
+void ast_sip_session_register_supplement(struct ast_sip_session_supplement *supplement)
+{
+	ast_sip_session_register_supplement_with_module(NULL, supplement);
+}

res/res_pjsip_session.c

@@ -58,6 +58,9 @@
 #define DEFAULT_NUM_SESSION_MEDIA 2
 
 /* Some forward declarations */
+static void handle_session_begin(struct ast_sip_session *session);
+static void handle_session_end(struct ast_sip_session *session);
+static void handle_session_destroy(struct ast_sip_session *session);
 static void handle_incoming_request(struct ast_sip_session *session, pjsip_rx_data *rdata);
 static void handle_incoming_response(struct ast_sip_session *session, pjsip_rx_data *rdata,
 		enum ast_sip_session_response_priority response_priority);
@@ -2088,7 +2091,6 @@ static int datastore_cmp(void *obj, void *arg, int flags)
 static void session_destructor(void *obj)
 {
 	struct ast_sip_session *session = obj;
-	struct ast_sip_session_supplement *supplement;
 	struct ast_sip_session_delayed_request *delay;
 	const char *endpoint_name = session->endpoint ?
 		ast_sorcery_object_get_id(session->endpoint) : "<none>";
@@ -2104,19 +2106,18 @@ static void session_destructor(void *obj)
 		, session->contact ? ast_sorcery_object_get_id(session->contact) : "<none>"
 		);
 
-	while ((supplement = AST_LIST_REMOVE_HEAD(&session->supplements, next))) {
-		if (supplement->session_destroy) {
-			supplement->session_destroy(session);
-		}
-		ast_free(supplement);
-	}
+	/* fire session destroy handler */
+	handle_session_destroy(session);
+
+	/* remove all registered supplements */
+	ast_sip_session_remove_supplements(session);
+	AST_LIST_HEAD_DESTROY(&session->supplements);
 
 	ast_taskprocessor_unreference(session->serializer);
 	ao2_cleanup(session->datastores);
 	ast_sip_session_media_state_free(session->active_media_state);
 	ast_sip_session_media_state_free(session->pending_media_state);
 
-	AST_LIST_HEAD_DESTROY(&session->supplements);
 	while ((delay = AST_LIST_REMOVE_HEAD(&session->delayed_requests, next))) {
 		delayed_request_free(delay);
 	}
@@ -2165,7 +2166,6 @@ struct ast_sip_session *ast_sip_session_alloc(struct ast_sip_endpoint *endpoint,
 {
 	RAII_VAR(struct ast_sip_session *, session, NULL, ao2_cleanup);
 	struct ast_sip_session *ret_session;
-	struct ast_sip_session_supplement *iter;
 	int dsp_features = 0;
 
 	session = ao2_alloc(sizeof(*session), session_destructor);
@@ -2247,11 +2247,9 @@ struct ast_sip_session *ast_sip_session_alloc(struct ast_sip_endpoint *endpoint,
 		ao2_ref(session, -1);
 		return NULL;
 	}
-	AST_LIST_TRAVERSE(&session->supplements, iter, next) {
-		if (iter->session_begin) {
-			iter->session_begin(session);
-		}
-	}
+
+	/* Fire seesion begin handlers */
+	handle_session_begin(session);
 
 	/* Avoid unnecessary ref manipulation to return a session */
 	ret_session = session;
@@ -3316,6 +3314,40 @@ static void handle_incoming_request(struct ast_sip_session *session, pjsip_rx_da
 	}
 }
 
+static void handle_session_begin(struct ast_sip_session *session)
+{
+	struct ast_sip_session_supplement *iter;
+
+	AST_LIST_TRAVERSE(&session->supplements, iter, next) {
+		if (iter->session_begin) {
+			iter->session_begin(session);
+		}
+	}
+}
+
+static void handle_session_destroy(struct ast_sip_session *session)
+{
+	struct ast_sip_session_supplement *iter;
+
+	AST_LIST_TRAVERSE(&session->supplements, iter, next) {
+		if (iter->session_destroy) {
+			iter->session_destroy(session);
+		}
+	}
+}
+
+static void handle_session_end(struct ast_sip_session *session)
+{
+	struct ast_sip_session_supplement *iter;
+
+	/* Session is dead.  Notify the supplements. */
+	AST_LIST_TRAVERSE(&session->supplements, iter, next) {
+		if (iter->session_end) {
+			iter->session_end(session);
+		}
+	}
+}
+
 static void handle_incoming_response(struct ast_sip_session *session, pjsip_rx_data *rdata,
 		enum ast_sip_session_response_priority response_priority)
 {
@@ -3388,17 +3420,13 @@ static void handle_outgoing_response(struct ast_sip_session *session, pjsip_tx_d
 static int session_end(void *vsession)
 {
 	struct ast_sip_session *session = vsession;
-	struct ast_sip_session_supplement *iter;
 
 	/* Stop the scheduled termination */
 	sip_session_defer_termination_stop_timer(session);
 
 	/* Session is dead.  Notify the supplements. */
-	AST_LIST_TRAVERSE(&session->supplements, iter, next) {
-		if (iter->session_end) {
-			iter->session_end(session);
-		}
-	}
+	handle_session_end(session);
+
 	return 0;
 }