From: Denis Osvald <denis.osvald@sartura.hr>
Date: Mon, 2 Jan 2017 16:33:26 +0000 (+0100)
Subject: server: check listen(2) return value
X-Git-Tag: upstream/2.3.0~278
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9b129c137ae4cb1232076ff2e3e43f6fdd2989a1;p=platform%2Fupstream%2Flibwebsockets.git

server: check listen(2) return value

The `listen` call can fail with EADDRINUSE after bind() succeeds, for
example because another process called listen on that port in the
meantime, or under some circumstances with IPv6-mapped-IPv4. This was
causing EINVAL on accept, with an infinite loop in case of libuv.

A reproducible example was to run nc -l -p 5555 ( OpenBSD netcat (Debian
patchlevel 1)) before starting test-server

Signed-off-by: Denis Osvald <denis.osvald@sartura.hr>
---

diff --git a/lib/server.c b/lib/server.c
index 8f6652ca..02b04afb 100644
--- a/lib/server.c
+++ b/lib/server.c
@@ -164,7 +164,14 @@ lws_context_init_server(struct lws_context_creation_info *info,
 	vhost->lserv_wsi = wsi;
 
 #if LWS_POSIX
-	listen(wsi->sock, LWS_SOMAXCONN);
+	n = listen(wsi->sock, LWS_SOMAXCONN);
+	if (n < 0) {
+		lwsl_err("listen failed with error %d\n", LWS_ERRNO);
+		vhost->lserv_wsi = NULL;
+		vhost->context->count_wsi_allocated--;
+		remove_wsi_socket_from_fds(wsi);
+		goto bail;
+	}
 	} /* for each thread able to independently listen */
 #else
 #if defined(LWS_WITH_ESP8266)