Fix worker thread resource leak in SIP TCP/TLS.

The SIP TCP/TLS worker threads were created joinable but noone could join
them if they died on their own.

* Fix the SIP TCP/TLS worker threads to not be created joinable.

* _sip_tcp_helper_thread() only needs one parameter since the pvt
parameter is only passed in as NULL and never used.

(closes issue ASTERISK-19203)
Reported by: Steve Davies

Review: https://reviewboard.asterisk.org/r/1714/
........

Merged revisions 356677 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 356690 from http://svn.asterisk.org/svn/asterisk/branches/10

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@356697 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index cb43652..417e7e3 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -1510,7 +1510,7 @@ static int get_domain(const char *str, char *domain, int len);
 static void get_realm(struct sip_pvt *p, const struct sip_request *req);
 
 /*-- TCP connection handling ---*/
-static void *_sip_tcp_helper_thread(struct sip_pvt *pvt, struct ast_tcptls_session_instance *tcptls_session);
+static void *_sip_tcp_helper_thread(struct ast_tcptls_session_instance *tcptls_session);
 static void *sip_tcp_worker_fn(void *);
 
 /*--- Constructing requests and responses */
@@ -2488,7 +2488,7 @@ static void *sip_tcp_worker_fn(void *data)
 {
        struct ast_tcptls_session_instance *tcptls_session = data;
 
-       return _sip_tcp_helper_thread(NULL, tcptls_session);
+       return _sip_tcp_helper_thread(tcptls_session);
 }
 
 /*! \brief Check if the authtimeout has expired.
@@ -2519,7 +2519,7 @@ static int sip_check_authtimeout(time_t start)
 /*! \brief SIP TCP thread management function
        This function reads from the socket, parses the packet into a request
 */
-static void *_sip_tcp_helper_thread(struct sip_pvt *pvt, struct ast_tcptls_session_instance *tcptls_session)
+static void *_sip_tcp_helper_thread(struct ast_tcptls_session_instance *tcptls_session)
 {
        int res, cl, timeout = -1, authenticated = 0, flags, after_poll = 0, need_poll = 1;
        time_t start;
@@ -26483,6 +26483,7 @@ static int sip_prepare_socket(struct sip_pvt *p)
        struct ast_tcptls_session_instance *tcptls_session;
        struct ast_tcptls_session_args *ca;
        struct ast_sockaddr sa_tmp;
+       pthread_t launched;
 
        /* check to see if a socket is already active */
        if ((s->fd != -1) && (s->type == SIP_TRANSPORT_UDP)) {
@@ -26507,7 +26508,7 @@ static int sip_prepare_socket(struct sip_pvt *p)
        }
 
        /* At this point we are dealing with a TCP/TLS connection
-        * 1. We need to check to see if a connectin thread exists
+        * 1. We need to check to see if a connection thread exists
         *    for this address, if so use that.
         * 2. If a thread does not exist for this address, but the tcptls_session
         *    exists on the socket, the connection was closed.
@@ -26578,7 +26579,7 @@ static int sip_prepare_socket(struct sip_pvt *p)
        /* Give the new thread a reference to the tcptls_session */
        ao2_ref(s->tcptls_session, +1);
 
-       if (ast_pthread_create_background(&ca->master, NULL, sip_tcp_worker_fn, s->tcptls_session)) {
+       if (ast_pthread_create_detached_background(&launched, NULL, sip_tcp_worker_fn, s->tcptls_session)) {
                ast_debug(1, "Unable to launch '%s'.", ca->name);
                ao2_ref(s->tcptls_session, -1); /* take away the thread ref we just gave it */
                goto create_tcptls_session_fail;
@@ -31578,6 +31579,7 @@ static int unload_module(void)
        struct sip_threadinfo *th;
        struct ast_context *con;
        struct ao2_iterator i;
+       int wait_count;
 
        network_change_event_unsubscribe();
 
@@ -31636,7 +31638,6 @@ static int unload_module(void)
                pthread_t thread = th->threadid;
                th->stop = 1;
                pthread_kill(thread, SIGURG);
-               pthread_join(thread, NULL);
                ao2_t_ref(th, -1, "decrement ref from iterator");
        }
        ao2_iterator_destroy(&i);
@@ -31682,21 +31683,11 @@ static int unload_module(void)
        sip_epa_unregister_all();
        destroy_escs();
 
-       if (default_tls_cfg.certfile) {
-               ast_free(default_tls_cfg.certfile);
-       }
-       if (default_tls_cfg.pvtfile) {
-               ast_free(default_tls_cfg.pvtfile);
-       }
-       if (default_tls_cfg.cipher) {
-               ast_free(default_tls_cfg.cipher);
-       }
-       if (default_tls_cfg.cafile) {
-               ast_free(default_tls_cfg.cafile);
-       }
-       if (default_tls_cfg.capath) {
-               ast_free(default_tls_cfg.capath);
-       }
+       ast_free(default_tls_cfg.certfile);
+       ast_free(default_tls_cfg.pvtfile);
+       ast_free(default_tls_cfg.cipher);
+       ast_free(default_tls_cfg.cafile);
+       ast_free(default_tls_cfg.capath);
 
        cleanup_all_regs();
        ASTOBJ_CONTAINER_DESTROYALL(&regl, sip_registry_destroy);
@@ -31714,6 +31705,21 @@ static int unload_module(void)
        ASTOBJ_CONTAINER_DESTROYALL(&submwil, sip_subscribe_mwi_destroy);
        ASTOBJ_CONTAINER_DESTROY(&submwil);
 
+       /*
+        * Wait awhile for the TCP/TLS thread container to become empty.
+        *
+        * XXX This is a hack, but the worker threads cannot be created
+        * joinable.  They can die on their own and remove themselves
+        * from the container thus resulting in a huge memory leak.
+        */
+       wait_count = 1000;
+       while (ao2_container_count(threadt) && --wait_count) {
+               sched_yield();
+       }
+       if (!wait_count) {
+               ast_debug(2, "TCP/TLS thread container did not become empty :(\n");
+       }
+
        ao2_t_ref(peers, -1, "unref the peers table");
        ao2_t_ref(peers_by_ip, -1, "unref the peers_by_ip table");
        ao2_t_ref(dialogs, -1, "unref the dialogs table");

diff --git a/channels/sip/include/sip.h b/channels/sip/include/sip.h
index 0ae8be8..2f9beff 100644 (file)
--- a/channels/sip/include/sip.h
+++ b/channels/sip/include/sip.h
@@ -1393,6 +1393,7 @@ struct tcptls_packet {
 };
 /*! \brief Definition of a thread that handles a socket */
 struct sip_threadinfo {
+       /*! TRUE if the thread needs to kill itself.  (The module is being unloaded.) */
        int stop;
        int alert_pipe[2];          /*! Used to alert tcptls thread when packet is ready to be written */
        pthread_t threadid;

diff --git a/include/asterisk/tcptls.h b/include/asterisk/tcptls.h
index e9b2371..c605013 100644 (file)
--- a/include/asterisk/tcptls.h
+++ b/include/asterisk/tcptls.h
@@ -136,6 +136,7 @@ struct ast_tcptls_session_args {
        struct ast_tls_config *tls_cfg; /*!< points to the SSL configuration if any */
        int accept_fd;
        int poll_timeout;
+       /*! Server accept_fn thread ID used for external shutdown requests. */
        pthread_t master;
        void *(*accept_fn)(void *); /*!< the function in charge of doing the accept */
        void (*periodic_fn)(void *);/*!< something we may want to run before after select on the accept socket */
@@ -154,6 +155,7 @@ struct ast_tcptls_session_instance {
        int client;
        struct ast_sockaddr remote_address;
        struct ast_tcptls_session_args *parent;
+       /*! \todo XXX Why do we still use this lock when this struct is allocated as an ao2 object which has its own lock? */
        ast_mutex_t lock;
 };