res_pjsip_pubsub.c: Fix body generator registration race.

Change-Id: Id8752073ef06472a2fd96080f4009fac42843e67

diff --git a/res/res_pjsip_pubsub.c b/res/res_pjsip_pubsub.c
index 6700475672780b7321c64a063a0b5b9d22e9b428..e744bad4fb5f46036c7ed92349261a781c4a7fc9 100644 (file)
--- a/res/res_pjsip_pubsub.c
+++ b/res/res_pjsip_pubsub.c
@@ -2541,20 +2541,28 @@ void ast_sip_unregister_subscription_handler(struct ast_sip_subscription_handler
        AST_RWLIST_TRAVERSE_SAFE_END;
 }
 
-static struct ast_sip_pubsub_body_generator *find_body_generator_type_subtype(const char *content_type,
-               const char *content_subtype)
+static struct ast_sip_pubsub_body_generator *find_body_generator_type_subtype_nolock(const char *type, const char *subtype)
 {
-       struct ast_sip_pubsub_body_generator *iter;
-       SCOPED_LOCK(lock, &body_generators, AST_RWLIST_RDLOCK, AST_RWLIST_UNLOCK);
+       struct ast_sip_pubsub_body_generator *gen;
 
-       AST_LIST_TRAVERSE(&body_generators, iter, list) {
-               if (!strcmp(iter->type, content_type) &&
-                               !strcmp(iter->subtype, content_subtype)) {
+       AST_LIST_TRAVERSE(&body_generators, gen, list) {
+               if (!strcmp(gen->type, type)
+                       && !strcmp(gen->subtype, subtype)) {
                        break;
                }
-       };
+       }
 
-       return iter;
+       return gen;
+}
+
+static struct ast_sip_pubsub_body_generator *find_body_generator_type_subtype(const char *type, const char *subtype)
+{
+       struct ast_sip_pubsub_body_generator *gen;
+
+       AST_RWLIST_RDLOCK(&body_generators);
+       gen = find_body_generator_type_subtype_nolock(type, subtype);
+       AST_RWLIST_UNLOCK(&body_generators);
+       return gen;
 }
 
 static struct ast_sip_pubsub_body_generator *find_body_generator_accept(const char *accept)
@@ -3092,14 +3100,14 @@ int ast_sip_pubsub_register_body_generator(struct ast_sip_pubsub_body_generator
        pj_str_t accept;
        pj_size_t accept_len;
 
-       existing = find_body_generator_type_subtype(generator->type, generator->subtype);
+       AST_RWLIST_WRLOCK(&body_generators);
+       existing = find_body_generator_type_subtype_nolock(generator->type, generator->subtype);
        if (existing) {
-               ast_log(LOG_WARNING, "Cannot register body generator of %s/%s."
-                               "One is already registered.\n", generator->type, generator->subtype);
+               AST_RWLIST_UNLOCK(&body_generators);
+               ast_log(LOG_WARNING, "A body generator for %s/%s is already registered.\n",
+                       generator->type, generator->subtype);
                return -1;
        }
-
-       AST_RWLIST_WRLOCK(&body_generators);
        AST_LIST_INSERT_HEAD(&body_generators, generator, list);
        AST_RWLIST_UNLOCK(&body_generators);