utils: fix memory leak + some small fixes

refs #2137

Change-Id: Iacb0825ef124ca033105010655947a1282844123

src/libknot/tsig-op.c

@@ -826,7 +826,6 @@ int knot_tsig_client_check_next(const knot_rrset_t *tsig_rr,
 	return knot_tsig_check_digest(tsig_rr, wire, size, prev_digest,
 	                              prev_digest_len, tsig_key,
 	                              prev_time_signed, 1);
-	return KNOT_ENOTSUP;
 }
 
 int knot_tsig_add(uint8_t *msg, size_t *msg_len, size_t msg_max_len,

src/utils/common/exec.h

@@ -115,6 +115,9 @@ void free_sign_context(sign_context_t *ctx);
  * \param pkt		Packet to sign.
  * \param sign_ctx	Sign context.
  * \param key_params	Key parameters.
+ *
+ * \retval KNOT_EOK	if success.
+ * \retval error code	if error.
  */
 int sign_packet(knot_packet_t           *pkt,
                 sign_context_t          *sign_ctx,
@@ -126,6 +129,9 @@ int sign_packet(knot_packet_t           *pkt,
  * \param pkt		Packet verify sign.
  * \param sign_ctx	Sign context.
  * \param key_params	Key parameters.
+ *
+ * \retval KNOT_EOK	if success.
+ * \retval error code	if error.
  */
 int verify_packet(const knot_packet_t     *pkt,
                   const sign_context_t    *sign_ctx,

src/utils/common/netio.c

@@ -48,6 +48,11 @@ server_t* server_create(const char *name, const char *service)
 	server->name = strdup(name);
 	server->service = strdup(service);
 
+	if (server->name == NULL || server->service == NULL) {
+		server_free(server);
+		return NULL;
+	}
+
 	// Return result.
 	return server;
 }
@@ -206,6 +211,9 @@ int net_connect(const server_t *local,
 			WARN("can't bind to %s#%s\n",
 			     local->name, local->service);
 		}
+
+		// Free getaddrr data.
+		freeaddrinfo(lres);
 	}
 
 	// Connect using socket.