* Fix unlocked accesses to feature_list. The feature_list is now also
authorRichard Mudgett <rmudgett@digium.com>
Wed, 10 Apr 2013 23:03:30 +0000 (23:03 +0000)
committerRichard Mudgett <rmudgett@digium.com>
Wed, 10 Apr 2013 23:03:30 +0000 (23:03 +0000)
protected by the features_lock.

* Made all calls to ast_find_call_feature() have the features_lock held.

* Fixed set_config_flags() to actually use find_group() to look for
feature groups in DYNAMIC_FEATURES.  The code originally assumed all
feature groups were listed in DYNAMIC_FEATURES.

* Make everyone use ast_rdlock_call_features(),
ast_unlock_call_features(), and new ast_wrlock_call_features() instead of
directly calling the rwlock API on features_lock.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@385277 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/features.c
main/manager.c

index 6859863..1130ba7 100644 (file)
@@ -3126,6 +3126,25 @@ static int builtin_atxfer(struct ast_channel *chan, struct ast_channel *peer, st
 
 AST_RWLOCK_DEFINE_STATIC(features_lock);
 
+/*! \note This is protected by features_lock. */
+static AST_LIST_HEAD_NOLOCK_STATIC(feature_list, ast_call_feature);
+
+static void ast_wrlock_call_features(void)
+{
+       ast_rwlock_wrlock(&features_lock);
+}
+
+void ast_rdlock_call_features(void)
+{
+       ast_rwlock_rdlock(&features_lock);
+}
+
+void ast_unlock_call_features(void)
+{
+       ast_rwlock_unlock(&features_lock);
+}
+
+/*! \note This is protected by features_lock. */
 static struct ast_call_feature builtin_features[] = {
        { AST_FEATURE_REDIRECT, "Blind Transfer", "blindxfer", "#", "#", builtin_blindtransfer, AST_FEATURE_FLAG_NEEDSDTMF, "" },
        { AST_FEATURE_REDIRECT, "Attended Transfer", "atxfer", "", "", builtin_atxfer, AST_FEATURE_FLAG_NEEDSDTMF, "" },
@@ -3135,10 +3154,7 @@ static struct ast_call_feature builtin_features[] = {
        { AST_FEATURE_AUTOMIXMON, "One Touch MixMonitor", "automixmon", "", "", builtin_automixmonitor, AST_FEATURE_FLAG_NEEDSDTMF, "" },
 };
 
-
-static AST_RWLIST_HEAD_STATIC(feature_list, ast_call_feature);
-
-/*! \brief register new feature into feature_list*/
+/*! \brief register new feature into feature_list */
 void ast_register_feature(struct ast_call_feature *feature)
 {
        if (!feature) {
@@ -3146,9 +3162,9 @@ void ast_register_feature(struct ast_call_feature *feature)
                return;
        }
 
-       AST_RWLIST_WRLOCK(&feature_list);
-       AST_RWLIST_INSERT_HEAD(&feature_list,feature,feature_entry);
-       AST_RWLIST_UNLOCK(&feature_list);
+       ast_wrlock_call_features();
+       AST_LIST_INSERT_HEAD(&feature_list, feature, feature_entry);
+       ast_unlock_call_features();
 
        ast_verb(2, "Registered Feature '%s'\n",feature->sname);
 }
@@ -3225,9 +3241,9 @@ void ast_unregister_feature(struct ast_call_feature *feature)
                return;
        }
 
-       AST_RWLIST_WRLOCK(&feature_list);
-       AST_RWLIST_REMOVE(&feature_list, feature, feature_entry);
-       AST_RWLIST_UNLOCK(&feature_list);
+       ast_wrlock_call_features();
+       AST_LIST_REMOVE(&feature_list, feature, feature_entry);
+       ast_unlock_call_features();
 
        ast_free(feature);
 }
@@ -3237,19 +3253,23 @@ static void ast_unregister_features(void)
 {
        struct ast_call_feature *feature;
 
-       AST_RWLIST_WRLOCK(&feature_list);
-       while ((feature = AST_RWLIST_REMOVE_HEAD(&feature_list, feature_entry))) {
+       ast_wrlock_call_features();
+       while ((feature = AST_LIST_REMOVE_HEAD(&feature_list, feature_entry))) {
                ast_free(feature);
        }
-       AST_RWLIST_UNLOCK(&feature_list);
+       ast_unlock_call_features();
 }
 
-/*! \brief find a call feature by name */
+/*!
+ * \internal
+ * \brief find a dynamic call feature by name
+ * \pre Expects features_lock to be at least readlocked
+ */
 static struct ast_call_feature *find_dynamic_feature(const char *name)
 {
        struct ast_call_feature *tmp;
 
-       AST_RWLIST_TRAVERSE(&feature_list, tmp, feature_entry) {
+       AST_LIST_TRAVERSE(&feature_list, tmp, feature_entry) {
                if (!strcasecmp(tmp->sname, name)) {
                        break;
                }
@@ -3295,19 +3315,9 @@ static struct feature_group *find_group(const char *name)
        return fg;
 }
 
-void ast_rdlock_call_features(void)
-{
-       ast_rwlock_rdlock(&features_lock);
-}
-
-void ast_unlock_call_features(void)
-{
-       ast_rwlock_unlock(&features_lock);
-}
-
 /*!
  * \internal
- * \pre Expects feature_lock to be readlocked
+ * \pre Expects features_lock to be at least readlocked
  */
 struct ast_call_feature *ast_find_call_feature(const char *name)
 {
@@ -3453,7 +3463,7 @@ static struct ast_datastore *get_feature_chan_ds(struct ast_channel *chan)
  * \internal
  * \brief Get the extension for a given builtin feature
  *
- * \pre expects feature_lock to be readlocked
+ * \pre expects features_lock to be readlocked
  *
  * \retval 0 success
  * \retval non-zero failiure
@@ -3570,17 +3580,17 @@ static void unmap_features(void)
 {
        int x;
 
-       ast_rwlock_wrlock(&features_lock);
+       ast_wrlock_call_features();
        for (x = 0; x < FEATURES_COUNT; x++)
                strcpy(builtin_features[x].exten, builtin_features[x].default_exten);
-       ast_rwlock_unlock(&features_lock);
+       ast_unlock_call_features();
 }
 
 static int remap_feature(const char *name, const char *value)
 {
        int x, res = -1;
 
-       ast_rwlock_wrlock(&features_lock);
+       ast_wrlock_call_features();
        for (x = 0; x < FEATURES_COUNT; x++) {
                if (strcasecmp(builtin_features[x].sname, name))
                        continue;
@@ -3589,7 +3599,7 @@ static int remap_feature(const char *name, const char *value)
                res = 0;
                break;
        }
-       ast_rwlock_unlock(&features_lock);
+       ast_unlock_call_features();
 
        return res;
 }
@@ -3620,7 +3630,7 @@ static int feature_interpret_helper(struct ast_channel *chan, struct ast_channel
                return -1; /* can not run feature operation */
        }
 
-       ast_rwlock_rdlock(&features_lock);
+       ast_rdlock_call_features();
        for (x = 0; x < FEATURES_COUNT; x++) {
                char feature_exten[FEATURE_MAX_LEN] = "";
 
@@ -3662,7 +3672,7 @@ static int feature_interpret_helper(struct ast_channel *chan, struct ast_channel
                                "Result: fail");
        }
 
-       ast_rwlock_unlock(&features_lock);
+       ast_unlock_call_features();
 
        if (!dynamic_features_buf || !ast_str_strlen(dynamic_features_buf) || feature_detected) {
                return res;
@@ -3672,9 +3682,7 @@ static int feature_interpret_helper(struct ast_channel *chan, struct ast_channel
 
        while ((tok = strsep(&tmp, "#"))) {
                AST_RWLIST_RDLOCK(&feature_groups);
-
                fg = find_group(tok);
-
                if (fg) {
                        AST_LIST_TRAVERSE(&fg->features, fge, entry) {
                                if (!strcmp(fge->exten, code)) {
@@ -3697,13 +3705,12 @@ static int feature_interpret_helper(struct ast_channel *chan, struct ast_channel
                                break;
                        }
                }
-
                AST_RWLIST_UNLOCK(&feature_groups);
 
-               AST_RWLIST_RDLOCK(&feature_list);
+               ast_rdlock_call_features();
 
                if (!(tmpfeature = find_dynamic_feature(tok))) {
-                       AST_RWLIST_UNLOCK(&feature_list);
+                       ast_unlock_call_features();
                        continue;
                }
 
@@ -3719,14 +3726,14 @@ static int feature_interpret_helper(struct ast_channel *chan, struct ast_channel
                                memcpy(feature, tmpfeature, sizeof(*feature));
                        }
                        if (res != AST_FEATURE_RETURN_KEEPTRYING) {
-                               AST_RWLIST_UNLOCK(&feature_list);
+                               ast_unlock_call_features();
                                break;
                        }
                        res = AST_FEATURE_RETURN_PASSDIGITS;
                } else if (!strncmp(tmpfeature->exten, code, strlen(code)))
                        res = AST_FEATURE_RETURN_STOREDIGITS;
 
-               AST_RWLIST_UNLOCK(&feature_list);
+               ast_unlock_call_features();
        }
 
        return res;
@@ -3809,7 +3816,7 @@ static void set_config_flags(struct ast_channel *chan, struct ast_bridge_config
 
        ast_clear_flag(config, AST_FLAGS_ALL);
 
-       ast_rwlock_rdlock(&features_lock);
+       ast_rdlock_call_features();
        for (x = 0; x < FEATURES_COUNT; x++) {
                if (!ast_test_flag(builtin_features + x, AST_FEATURE_FLAG_NEEDSDTMF))
                        continue;
@@ -3820,7 +3827,7 @@ static void set_config_flags(struct ast_channel *chan, struct ast_bridge_config
                if (ast_test_flag(&(config->features_callee), builtin_features[x].feature_mask))
                        ast_set_flag(config, AST_BRIDGE_DTMF_CHANNEL_1);
        }
-       ast_rwlock_unlock(&features_lock);
+       ast_unlock_call_features();
 
        if (!(ast_test_flag(config, AST_BRIDGE_DTMF_CHANNEL_0) && ast_test_flag(config, AST_BRIDGE_DTMF_CHANNEL_1))) {
                const char *dynamic_features = pbx_builtin_getvar_helper(chan, "DYNAMIC_FEATURES");
@@ -3835,7 +3842,8 @@ static void set_config_flags(struct ast_channel *chan, struct ast_bridge_config
                                struct feature_group *fg;
 
                                AST_RWLIST_RDLOCK(&feature_groups);
-                               AST_RWLIST_TRAVERSE(&feature_groups, fg, entry) {
+                               fg = find_group(tok);
+                               if (fg) {
                                        struct feature_group_exten *fge;
 
                                        AST_LIST_TRAVERSE(&fg->features, fge, entry) {
@@ -3849,7 +3857,7 @@ static void set_config_flags(struct ast_channel *chan, struct ast_bridge_config
                                }
                                AST_RWLIST_UNLOCK(&feature_groups);
 
-                               AST_RWLIST_RDLOCK(&feature_list);
+                               ast_rdlock_call_features();
                                if ((feature = find_dynamic_feature(tok)) && ast_test_flag(feature, AST_FEATURE_FLAG_NEEDSDTMF)) {
                                        if (ast_test_flag(feature, AST_FEATURE_FLAG_BYCALLER)) {
                                                ast_set_flag(config, AST_BRIDGE_DTMF_CHANNEL_0);
@@ -3858,7 +3866,7 @@ static void set_config_flags(struct ast_channel *chan, struct ast_bridge_config
                                                ast_set_flag(config, AST_BRIDGE_DTMF_CHANNEL_1);
                                        }
                                }
-                               AST_RWLIST_UNLOCK(&feature_list);
+                               ast_unlock_call_features();
                        }
                }
        }
@@ -3974,7 +3982,7 @@ static struct ast_channel *feature_request_and_dial(struct ast_channel *caller,
        }
 
        /* support dialing of the featuremap disconnect code while performing an attended tranfer */
-       ast_rwlock_rdlock(&features_lock);
+       ast_rdlock_call_features();
        for (x = 0; x < FEATURES_COUNT; x++) {
                if (strcasecmp(builtin_features[x].sname, "disconnect"))
                        continue;
@@ -3985,7 +3993,7 @@ static struct ast_channel *feature_request_and_dial(struct ast_channel *caller,
                memset(dialed_code, 0, len);
                break;
        }
-       ast_rwlock_unlock(&features_lock);
+       ast_unlock_call_features();
        x = 0;
        started = ast_tvnow();
        to = timeout;
@@ -6247,14 +6255,14 @@ static void process_applicationmap_line(struct ast_variable *var)
                return;
        }
 
-       AST_RWLIST_RDLOCK(&feature_list);
+       ast_rdlock_call_features();
        if (find_dynamic_feature(var->name)) {
-               AST_RWLIST_UNLOCK(&feature_list);
+               ast_unlock_call_features();
                ast_log(LOG_WARNING, "Dynamic Feature '%s' specified more than once!\n",
                        var->name);
                return;
        }
-       AST_RWLIST_UNLOCK(&feature_list);
+       ast_unlock_call_features();
 
        if (!(feature = ast_calloc(1, sizeof(*feature)))) {
                return;
@@ -6456,14 +6464,13 @@ static int process_config(struct ast_config *cfg)
                for (var = ast_variable_browse(cfg, ctg); var; var = var->next) {
                        struct ast_call_feature *feature;
 
-                       AST_RWLIST_RDLOCK(&feature_list);
-                       if (!(feature = find_dynamic_feature(var->name)) &&
-                           !(feature = ast_find_call_feature(var->name))) {
-                               AST_RWLIST_UNLOCK(&feature_list);
+                       ast_rdlock_call_features();
+                       feature = ast_find_call_feature(var->name);
+                       ast_unlock_call_features();
+                       if (!feature) {
                                ast_log(LOG_WARNING, "Feature '%s' was not found.\n", var->name);
                                continue;
                        }
-                       AST_RWLIST_UNLOCK(&feature_list);
 
                        register_group_feature(fg, var->value, feature);
                }
@@ -7263,41 +7270,41 @@ static char *handle_feature_show(struct ast_cli_entry *e, int cmd, struct ast_cl
 
        ast_cli(a->fd, HFS_FORMAT, "Pickup", "*8", ast_pickup_ext());          /* default hardcoded above, so we'll hardcode it here */
 
-       ast_rwlock_rdlock(&features_lock);
+       ast_rdlock_call_features();
        for (i = 0; i < FEATURES_COUNT; i++)
                ast_cli(a->fd, HFS_FORMAT, builtin_features[i].fname, builtin_features[i].default_exten, builtin_features[i].exten);
-       ast_rwlock_unlock(&features_lock);
+       ast_unlock_call_features();
 
        ast_cli(a->fd, "\n");
        ast_cli(a->fd, HFS_FORMAT, "Dynamic Feature", "Default", "Current");
        ast_cli(a->fd, HFS_FORMAT, "---------------", "-------", "-------");
-       if (AST_RWLIST_EMPTY(&feature_list)) {
+       ast_rdlock_call_features();
+       if (AST_LIST_EMPTY(&feature_list)) {
                ast_cli(a->fd, "(none)\n");
        } else {
-               AST_RWLIST_RDLOCK(&feature_list);
-               AST_RWLIST_TRAVERSE(&feature_list, feature, feature_entry) {
+               AST_LIST_TRAVERSE(&feature_list, feature, feature_entry) {
                        ast_cli(a->fd, HFS_FORMAT, feature->sname, "no def", feature->exten);
                }
-               AST_RWLIST_UNLOCK(&feature_list);
        }
+       ast_unlock_call_features();
 
        ast_cli(a->fd, "\nFeature Groups:\n");
        ast_cli(a->fd, "---------------\n");
+       AST_RWLIST_RDLOCK(&feature_groups);
        if (AST_RWLIST_EMPTY(&feature_groups)) {
                ast_cli(a->fd, "(none)\n");
        } else {
                struct feature_group *fg;
                struct feature_group_exten *fge;
 
-               AST_RWLIST_RDLOCK(&feature_groups);
                AST_RWLIST_TRAVERSE(&feature_groups, fg, entry) {
                        ast_cli(a->fd, "===> Group: %s\n", fg->gname);
                        AST_LIST_TRAVERSE(&fg->features, fge, entry) {
                                ast_cli(a->fd, "===> --> %s (%s)\n", fge->feature->sname, fge->exten);
                        }
                }
-               AST_RWLIST_UNLOCK(&feature_groups);
        }
+       AST_RWLIST_UNLOCK(&feature_groups);
 
        iter = ao2_iterator_init(parkinglots, 0);
        while ((curlot = ao2_iterator_next(&iter))) {
@@ -7667,7 +7674,7 @@ static int manager_parkinglot_list(struct mansession *s, const struct message *m
        return RESULT_SUCCESS;
 }
 
-/*! 
+/*!
  * \brief Dump parking lot status
  * \param s
  * \param m
@@ -9079,8 +9086,12 @@ static int featuremap_write(struct ast_channel *chan, const char *cmd, char *dat
 {
        struct feature_datastore *feature_ds;
        struct feature_exten *fe;
+       struct ast_call_feature *feat;
 
-       if (!ast_find_call_feature(data)) {
+       ast_rdlock_call_features();
+       feat = ast_find_call_feature(data);
+       ast_unlock_call_features();
+       if (!feat) {
                ast_log(LOG_WARNING, "Invalid argument '%s' to FEATUREMAP()\n", data);
                return -1;
        }
index f5314af..dd920e2 100644 (file)
@@ -3902,7 +3902,10 @@ static int action_atxfer(struct mansession *s, const struct message *m)
                return 0;
        }
 
-       if (!(atxfer_feature = ast_find_call_feature("atxfer"))) {
+       ast_rdlock_call_features();
+       atxfer_feature = ast_find_call_feature("atxfer");
+       ast_unlock_call_features();
+       if (!atxfer_feature) {
                astman_send_error(s, m, "No attended transfer feature found");
                return 0;
        }