interceptor: check for invalid fd

Author: lws-team

include/libwebsockets/lws-network-helper.h

@@ -103,7 +103,7 @@ lws_canonical_hostname(struct lws_context *context);
  *	truncated if there is not enough room.  If either cannot be
  *	determined, they will be returned as valid zero-length strings.
  */
-LWS_VISIBLE LWS_EXTERN void
+LWS_VISIBLE LWS_EXTERN int LWS_WARN_UNUSED_RESULT
 lws_get_peer_addresses(struct lws *wsi, lws_sockfd_type fd, char *name,
 		       int name_len, char *rip, int rip_len);
 

lib/core-net/network.c

@@ -105,8 +105,12 @@ lws_get_addresses(struct lws_vhost *vh, void *ads, char *name,
 	struct addrinfo ai, *res;
 	struct sockaddr_in addr4;
 
+	if (!rip)
+		return -1;
+
 	rip[0] = '\0';
-	name[0] = '\0';
+	if (name)
+		name[0] = '\0';
 	addr4.sin_family = AF_UNSPEC;
 
 #ifdef LWS_WITH_IPV6
@@ -212,7 +216,7 @@ lws_get_peer_simple(struct lws *wsi, char *name, size_t namelen)
 }
 #endif
 
-void
+int
 lws_get_peer_addresses(struct lws *wsi, lws_sockfd_type fd, char *name,
 		       int name_len, char *rip, int rip_len)
 {
@@ -224,8 +228,13 @@ lws_get_peer_addresses(struct lws *wsi, lws_sockfd_type fd, char *name,
 	struct sockaddr_in sin4;
 	void *p;
 
-	rip[0] = '\0';
-	name[0] = '\0';
+	if (!lws_socket_is_valid(fd))
+		return 1;
+
+	if (rip)
+		rip[0] = '\0';
+	if (name)
+		name[0] = '\0';
 
 #ifdef LWS_WITH_IPV6
 	if (LWS_IPV6_ENABLED(wsi->a.vhost)) {
@@ -245,19 +254,20 @@ lws_get_peer_addresses(struct lws *wsi, lws_sockfd_type fd, char *name,
 		lwsl_wsi_warn(wsi, "getpeername: %s",
 			lws_errno_describe(LWS_ERRNO, t16, sizeof(t16)));
 #endif
-		goto bail;
+		return 1;
 	}
 
-	lws_get_addresses(wsi->a.vhost, p, name, name_len, rip, rip_len);
+	return lws_get_addresses(wsi->a.vhost, p, name, name_len, rip, rip_len);
 
-bail:
-#endif
+#else
 	(void)wsi;
 	(void)fd;
 	(void)name;
 	(void)name_len;
 	(void)rip;
 	(void)rip_len;
+	return 0;
+#endif
 }
 
 

lib/roles/http/server/interceptor.c

@@ -285,8 +285,13 @@ lws_interceptor_check(struct lws *wsi, const struct lws_protocols *prot)
 		lws_sockaddr46 sa46;
 		int allow = 0;
 
-		lws_get_peer_addresses(wsi, lws_get_socket_fd(wsi),
-				NULL, 0, ip, sizeof(ip));
+		lws_sockfd_type fd = lws_get_socket_fd(wsi);
+
+		if (lws_get_peer_addresses(wsi, fd,
+				NULL, 0, ip, sizeof(ip))) {
+			lwsl_err("%s: get peer ads fail\n", __func__);
+			return 1;
+		}
 
 		if (!lws_sa46_parse_numeric_address(ip, &sa46)) {
 			while (cidr) {