b2b_logic: don't crash when searching inexistent tuple by key

Searching the current tuple by key for accessing the logic context
should not cause a crash. As the hash is not locked or the structure
ref counted, there is a distinct possibility that the tuple cannot
be found anymore.

Related to #3117

(cherry picked from commit d05d408)

modules/b2b_logic/b2b_logic_ctx.c

@@ -25,8 +25,8 @@ static b2bl_tuple_t *b2bl_ctx_get_tuple(str *key)
 {
 	b2bl_tuple_t *tuple = b2bl_get_tuple(key);
 	if (!tuple) {
-		LM_BUG("could not find logic tuple [%.*s]\n", key->len, key->s);
-		abort();
+		LM_ERR("could not find logic tuple [%.*s]\n", key->len, key->s);
+		return NULL;
 	}
 	return tuple;
 }
@@ -55,20 +55,38 @@ int b2bl_ctx_register_ptr(context_destroy_f f)
 void b2bl_ctx_put_int(str *key, int pos, int data)
 {
 	b2bl_tuple_t *tuple = b2bl_ctx_get_tuple(key);
+
+	if (!tuple) {
+		LM_ERR("Failed to store data in b2b logic context\n");
+		return;
+	}
+
 	context_put_int(CONTEXT_B2B_LOGIC, context_of(tuple), pos, data);
 	b2bl_ctx_release_tuple(tuple);
 }
 
 void b2bl_ctx_put_str(str *key, int pos, str *data)
 {
 	b2bl_tuple_t *tuple = b2bl_ctx_get_tuple(key);
+
+	if (!tuple) {
+		LM_ERR("Failed to store data in b2b logic context\n");
+		return;
+	}
+
 	context_put_str(CONTEXT_B2B_LOGIC, context_of(tuple), pos, data);
 	b2bl_ctx_release_tuple(tuple);
 }
 
 void b2bl_ctx_put_ptr(str *key, int pos, void *data)
 {
 	b2bl_tuple_t *tuple = b2bl_ctx_get_tuple(key);
+
+	if (!tuple) {
+		LM_ERR("Failed to store data in b2b logic context\n");
+		return;
+	}
+
 	context_put_ptr(CONTEXT_B2B_LOGIC, context_of(tuple), pos, data);
 	b2bl_ctx_release_tuple(tuple);
 }
@@ -77,6 +95,12 @@ int b2bl_ctx_get_int(str *key, int pos)
 {
 	int ret;
 	b2bl_tuple_t *tuple = b2bl_ctx_get_tuple(key);
+
+	if (!tuple) {
+		LM_ERR("Failed to retrieve data from b2b logic context\n");
+		return 0;
+	}
+
 	ret = context_get_int(CONTEXT_B2B_LOGIC, context_of(tuple), pos);
 	b2bl_ctx_release_tuple(tuple);
 	return ret;
@@ -86,6 +110,12 @@ str *b2bl_ctx_get_str(str *key, int pos)
 {
 	str *ret;
 	b2bl_tuple_t *tuple = b2bl_ctx_get_tuple(key);
+
+	if (!tuple) {
+		LM_ERR("Failed to retrieve data from b2b logic context\n");
+		return &STR_NULL;
+	}
+
 	ret = context_get_str(CONTEXT_B2B_LOGIC, context_of(tuple), pos);
 	b2bl_ctx_release_tuple(tuple);
 	return ret;
@@ -95,6 +125,12 @@ void *b2bl_ctx_get_ptr(str *key, int pos)
 {
 	void *ret;
 	b2bl_tuple_t *tuple = b2bl_ctx_get_tuple(key);
+
+	if (!tuple) {
+		LM_ERR("Failed to retrieve data from b2b logic context\n");
+		return NULL;
+	}
+
 	ret = context_get_ptr(CONTEXT_B2B_LOGIC, context_of(tuple), pos);
 	b2bl_ctx_release_tuple(tuple);
 	return ret;