res_hep_{pjsip|rtcp}: Decline module loads if res_hep had not loaded

A crash can occur in res_hep_pjsip or res_hep_rtcp if res_hep has not
loaded and does not have a configuration file. Previously when this
occurred, checks were put in to see if the configuration was loaded
successfully. While this is a good idea - and has been added to the
offending function in res_hep - the reality is res_hep_pjsip and
res_hep_rtcp have no business running if res_hep isn't also running.

As such, this patch also adds a function to res_hep that returns whether
or not it successfully loaded. Oddly enough, ast_module_check returns
"everything is peachy" even if a module declined its load - so it cannot
be solely relied on. res_hep_pjsip and res_hep_rtcp now also check this
function to see if they should continue to load; if it fails, they
decline their load as well.

ASTERISK-26096 #close

Change-Id: I007e535fcc2e51c2ca48534f48c5fc2ac38935ea

4 files changed, 22 insertions, 0 deletions

diff --git a/res/res_hep.c b/res/res_hep.c
index 723b27df8..15e779012 100644
--- a/res/res_hep.c
+++ b/res/res_hep.c
@@ -409,9 +409,21 @@ enum hep_uuid_type hepv3_get_uuid_type(void)
 {
 	RAII_VAR(struct module_config *, config, ao2_global_obj_ref(global_config), ao2_cleanup);
 
+	if (!config) {
+		/* Well, that's unfortunate. Return something. */
+		return HEP_UUID_TYPE_CALL_ID;
+	}
+
 	return config->general->uuid_type;
 }
 
+int hepv3_is_loaded(void)
+{
+	RAII_VAR(struct module_config *, config, ao2_global_obj_ref(global_config), ao2_cleanup);
+
+	return (config != NULL) ? 1 : 0;
+}
+
 struct hepv3_capture_info *hepv3_create_capture_info(const void *payload, size_t len)
 {
 	struct hepv3_capture_info *info;
diff --git a/res/res_hep.exports.in b/res/res_hep.exports.in
index df0f2b4f7..e318ac97f 100644
--- a/res/res_hep.exports.in
+++ b/res/res_hep.exports.in
@@ -3,6 +3,7 @@
 		LINKER_SYMBOL_PREFIX*hepv3_send_packet;
 		LINKER_SYMBOL_PREFIX*hepv3_create_capture_info;
 		LINKER_SYMBOL_PREFIX*hepv3_get_uuid_type;
+		LINKER_SYMBOL_PREFIX*hepv3_is_loaded;
 	local:
 		*;
 };
diff --git a/res/res_hep_pjsip.c b/res/res_hep_pjsip.c
index 936db9300..8f5baa2cb 100644
--- a/res/res_hep_pjsip.c
+++ b/res/res_hep_pjsip.c
@@ -210,6 +210,11 @@ static int load_module(void)
 {
 	CHECK_PJSIP_MODULE_LOADED();
 
+	if (!ast_module_check("res_hep.so") || !hepv3_is_loaded()) {
+		ast_log(AST_LOG_WARNING, "res_hep is not loaded or running; declining module load\n");
+		return AST_MODULE_LOAD_DECLINE;
+	}
+
 	ast_sip_register_service(&logging_module);
 	return AST_MODULE_LOAD_SUCCESS;
 }
diff --git a/res/res_hep_rtcp.c b/res/res_hep_rtcp.c
index 49a92539f..d77b19c92 100644
--- a/res/res_hep_rtcp.c
+++ b/res/res_hep_rtcp.c
@@ -149,6 +149,10 @@ static void rtp_topic_handler(void *data, struct stasis_subscription *sub, struc
 
 static int load_module(void)
 {
+	if (!ast_module_check("res_hep.so") || !hepv3_is_loaded()) {
+		ast_log(AST_LOG_WARNING, "res_hep is not loaded or running; declining module load\n");
+		return AST_MODULE_LOAD_DECLINE;
+	}
 
 	stasis_rtp_subscription = stasis_subscribe(ast_rtp_topic(),
 		rtp_topic_handler, NULL);