pjsip_scheduler.c: Fix ao2 usage errors.

* Removed several invalid uses of OBJ_NOLOCK.  These uses resulted in the
'tasks' container being accessed without a lock in a multi-threaded
environment.  A recipe for crashes.

* Removed needlessly obtaining schtd object references.  If the caller
providing you a pointer to an object doesn't have a valid reference then
you cannot safely get one from it.

* Getting a ref to 'tasks' when you aren't copying the pointer into
another location is useless.  The 'tasks' container pointer is global.

* Removed many unnecessary uses of RAII_VAR.

* Make ast_sip_schedule_task() name parameter const.

ASTERISK_26806

Change-Id: I5c62488e651314e2a1dbc01f5b078a15512d73db

diff --git a/include/asterisk/res_pjsip.h b/include/asterisk/res_pjsip.h
index 8cb428f6ee3139f856249ae11b35e0228a98dece..d091f9a51a0e016ddee29e3f6bbe543c90f936d4 100644 (file)
--- a/include/asterisk/res_pjsip.h
+++ b/include/asterisk/res_pjsip.h
@@ -1702,7 +1702,7 @@ struct ast_sip_sched_task;
  *
  */
 struct ast_sip_sched_task *ast_sip_schedule_task(struct ast_taskprocessor *serializer,
-       int interval, ast_sip_task sip_task, char *name, void *task_data,
+       int interval, ast_sip_task sip_task, const char *name, void *task_data,
        enum ast_sip_scheduler_task_flags flags);
 
 /*!

diff --git a/res/res_pjsip/pjsip_scheduler.c b/res/res_pjsip/pjsip_scheduler.c
index 7520db8c5f90bfc5aa263d486ccb87fe220690b1..43a9f59cb5c69518ce474096b357f61785548711 100644 (file)
--- a/res/res_pjsip/pjsip_scheduler.c
+++ b/res/res_pjsip/pjsip_scheduler.c
@@ -62,7 +62,7 @@ struct ast_sip_sched_task {
        enum ast_sip_scheduler_task_flags flags;
        /*! the serializer to be used (if any) */
        struct ast_taskprocessor *serializer;
-       /* A name to be associated with the task */
+       /*! A name to be associated with the task */
        char name[0];
 };
 
@@ -115,7 +115,7 @@ static int run_task(void *data)
                delay = schtd->interval - (ast_tvdiff_ms(schtd->last_end, schtd->last_start) % schtd->interval);
        }
 
-       schtd->current_scheduler_id = ast_sched_add(scheduler_context, delay, push_to_serializer, (const void *)schtd);
+       schtd->current_scheduler_id = ast_sched_add(scheduler_context, delay, push_to_serializer, schtd);
        if (schtd->current_scheduler_id < 0) {
                schtd->interval = 0;
                ao2_unlock(schtd);
@@ -166,28 +166,28 @@ int ast_sip_sched_task_cancel(struct ast_sip_sched_task *schtd)
 
 int ast_sip_sched_task_cancel_by_name(const char *name)
 {
-       RAII_VAR(struct ast_sip_sched_task *, schtd, NULL, ao2_cleanup);
+       int res;
+       struct ast_sip_sched_task *schtd;
 
        if (ast_strlen_zero(name)) {
                return -1;
        }
 
-       schtd = ao2_find(tasks, name, OBJ_SEARCH_KEY | OBJ_NOLOCK);
+       schtd = ao2_find(tasks, name, OBJ_SEARCH_KEY);
        if (!schtd) {
                return -1;
        }
 
-       return ast_sip_sched_task_cancel(schtd);
+       res = ast_sip_sched_task_cancel(schtd);
+       ao2_ref(schtd, -1);
+       return res;
 }
 
 
 int ast_sip_sched_task_get_times(struct ast_sip_sched_task *schtd,
        struct timeval *queued, struct timeval *last_start, struct timeval *last_end)
 {
-       if (!ao2_ref_and_lock(schtd)) {
-               return -1;
-       }
-
+       ao2_lock(schtd);
        if (queued) {
                memcpy(queued, &schtd->when_queued, sizeof(struct timeval));
        }
@@ -197,8 +197,7 @@ int ast_sip_sched_task_get_times(struct ast_sip_sched_task *schtd,
        if (last_end) {
                memcpy(last_end, &schtd->last_end, sizeof(struct timeval));
        }
-
-       ao2_unlock_and_unref(schtd);
+       ao2_unlock(schtd);
 
        return 0;
 }
@@ -206,18 +205,21 @@ int ast_sip_sched_task_get_times(struct ast_sip_sched_task *schtd,
 int ast_sip_sched_task_get_times_by_name(const char *name,
        struct timeval *queued, struct timeval *last_start, struct timeval *last_end)
 {
-       RAII_VAR(struct ast_sip_sched_task *, schtd, NULL, ao2_cleanup);
+       int res;
+       struct ast_sip_sched_task *schtd;
 
        if (ast_strlen_zero(name)) {
                return -1;
        }
 
-       schtd = ao2_find(tasks, name, OBJ_SEARCH_KEY | OBJ_NOLOCK);
+       schtd = ao2_find(tasks, name, OBJ_SEARCH_KEY);
        if (!schtd) {
                return -1;
        }
 
-       return ast_sip_sched_task_get_times(schtd, queued, last_start, last_end);
+       res = ast_sip_sched_task_get_times(schtd, queued, last_start, last_end);
+       ao2_ref(schtd, -1);
+       return res;
 }
 
 int ast_sip_sched_task_get_name(struct ast_sip_sched_task *schtd, char *name, size_t maxlen)
@@ -226,13 +228,9 @@ int ast_sip_sched_task_get_name(struct ast_sip_sched_task *schtd, char *name, si
                return -1;
        }
 
-       if (!ao2_ref_and_lock(schtd)) {
-               return -1;
-       }
-
+       ao2_lock(schtd);
        ast_copy_string(name, schtd->name, maxlen);
-
-       ao2_unlock_and_unref(schtd);
+       ao2_unlock(schtd);
 
        return 0;
 }
@@ -243,9 +241,7 @@ int ast_sip_sched_task_get_next_run(struct ast_sip_sched_task *schtd)
        struct timeval since_when;
        struct timeval now;
 
-       if (!ao2_ref_and_lock(schtd)) {
-               return -1;
-       }
+       ao2_lock(schtd);
 
        if (schtd->interval) {
                delay = schtd->interval;
@@ -264,50 +260,52 @@ int ast_sip_sched_task_get_next_run(struct ast_sip_sched_task *schtd)
                delay = -1;
        }
 
-       ao2_unlock_and_unref(schtd);
+       ao2_unlock(schtd);
 
        return delay;
 }
 
 int ast_sip_sched_task_get_next_run_by_name(const char *name)
 {
-       RAII_VAR(struct ast_sip_sched_task *, schtd, NULL, ao2_cleanup);
+       int next_run;
+       struct ast_sip_sched_task *schtd;
 
        if (ast_strlen_zero(name)) {
                return -1;
        }
 
-       schtd = ao2_find(tasks, name, OBJ_SEARCH_KEY | OBJ_NOLOCK);
+       schtd = ao2_find(tasks, name, OBJ_SEARCH_KEY);
        if (!schtd) {
                return -1;
        }
 
-       return ast_sip_sched_task_get_next_run(schtd);
+       next_run = ast_sip_sched_task_get_next_run(schtd);
+       ao2_ref(schtd, -1);
+       return next_run;
 }
 
 int ast_sip_sched_is_task_running(struct ast_sip_sched_task *schtd)
 {
-       if (!schtd) {
-               return 0;
-       }
-
-       return schtd->is_running;
+       return schtd ? schtd->is_running : 0;
 }
 
 int ast_sip_sched_is_task_running_by_name(const char *name)
 {
-       RAII_VAR(struct ast_sip_sched_task *, schtd, NULL, ao2_cleanup);
+       int is_running;
+       struct ast_sip_sched_task *schtd;
 
        if (ast_strlen_zero(name)) {
                return 0;
        }
 
-       schtd = ao2_find(tasks, name, OBJ_SEARCH_KEY | OBJ_NOLOCK);
+       schtd = ao2_find(tasks, name, OBJ_SEARCH_KEY);
        if (!schtd) {
                return 0;
        }
 
-       return schtd->is_running;
+       is_running = schtd->is_running;
+       ao2_ref(schtd, -1);
+       return is_running;
 }
 
 static void schtd_destructor(void *data)
@@ -323,7 +321,8 @@ static void schtd_destructor(void *data)
 }
 
 struct ast_sip_sched_task *ast_sip_schedule_task(struct ast_taskprocessor *serializer,
-       int interval, ast_sip_task sip_task, char *name, void *task_data, enum ast_sip_scheduler_task_flags flags)
+       int interval, ast_sip_task sip_task, const char *name, void *task_data,
+       enum ast_sip_scheduler_task_flags flags)
 {
 #define ID_LEN 13 /* task_deadbeef */
        struct ast_sip_sched_task *schtd;
@@ -354,7 +353,7 @@ struct ast_sip_sched_task *ast_sip_schedule_task(struct ast_taskprocessor *seria
        if (flags & AST_SIP_SCHED_TASK_DATA_AO2) {
                ao2_ref(task_data, +1);
        }
-       res = ast_sched_add(scheduler_context, interval, push_to_serializer, (const void *)schtd);
+       res = ast_sched_add(scheduler_context, interval, push_to_serializer, schtd);
        if (res < 0) {
                ao2_ref(schtd, -1);
                return NULL;
@@ -371,14 +370,14 @@ static char *cli_show_tasks(struct ast_cli_entry *e, int cmd, struct ast_cli_arg
 {
        struct ao2_iterator i;
        struct ast_sip_sched_task *schtd;
-       const char *log_format = ast_logger_get_dateformat();
+       const char *log_format;
        struct ast_tm tm;
        char queued[32];
        char last_start[32];
        char next_start[32];
        int datelen;
-       struct timeval now = ast_tvnow();
-       const char *separator = "======================================";
+       struct timeval now;
+       static const char separator[] = "======================================";
 
        switch (cmd) {
        case CLI_INIT:
@@ -394,6 +393,9 @@ static char *cli_show_tasks(struct ast_cli_entry *e, int cmd, struct ast_cli_arg
                return CLI_SHOWUSAGE;
        }
 
+       now = ast_tvnow();
+       log_format = ast_logger_get_dateformat();
+
        ast_localtime(&now, &tm, NULL);
        datelen = ast_strftime(queued, sizeof(queued), log_format, &tm);
 
@@ -408,12 +410,16 @@ static char *cli_show_tasks(struct ast_cli_entry *e, int cmd, struct ast_cli_arg
                datelen, separator, separator, datelen + 8, separator);
 
 
-       ao2_ref(tasks, +1);
        ao2_rdlock(tasks);
-       i = ao2_iterator_init(tasks, 0);
+       i = ao2_iterator_init(tasks, AO2_ITERATOR_DONTLOCK);
        while ((schtd = ao2_iterator_next(&i))) {
-               int next_run_sec = ast_sip_sched_task_get_next_run(schtd) / 1000;
-               struct timeval next = ast_tvadd(now, (struct timeval) {next_run_sec, 0});
+               int next_run_sec;
+               struct timeval next;
+
+               ao2_lock(schtd);
+
+               next_run_sec = ast_sip_sched_task_get_next_run(schtd) / 1000;
+               next = ast_tvadd(now, (struct timeval) {next_run_sec, 0});
 
                ast_localtime(&schtd->when_queued, &tm, NULL);
                ast_strftime(queued, sizeof(queued), log_format, &tm);
@@ -436,11 +442,12 @@ static char *cli_show_tasks(struct ast_cli_entry *e, int cmd, struct ast_cli_arg
                        datelen, queued, last_start,
                        next_start,
                        next_run_sec);
+               ao2_unlock(schtd);
+
                ao2_cleanup(schtd);
        }
        ao2_iterator_destroy(&i);
        ao2_unlock(tasks);
-       ao2_ref(tasks, -1);
        ast_cli(a->fd, "\n");
 
        return CLI_SUCCESS;
@@ -463,8 +470,9 @@ int ast_sip_initialize_scheduler(void)
                return -1;
        }
 
-       tasks = ao2_container_alloc_hash(AO2_ALLOC_OPT_LOCK_RWLOCK, AO2_CONTAINER_ALLOC_OPT_DUPS_REJECT,
-               TASK_BUCKETS, ast_sip_sched_task_hash_fn, ast_sip_sched_task_sort_fn, ast_sip_sched_task_cmp_fn);
+       tasks = ao2_container_alloc_hash(AO2_ALLOC_OPT_LOCK_RWLOCK,
+               AO2_CONTAINER_ALLOC_OPT_DUPS_REJECT, TASK_BUCKETS, ast_sip_sched_task_hash_fn,
+               ast_sip_sched_task_sort_fn, ast_sip_sched_task_cmp_fn);
        if (!tasks) {
                ast_log(LOG_ERROR, "Failed to allocate task container. Aborting load\n");
                ast_sched_context_destroy(scheduler_context);