From c065427ebe89dd2dc64938bc37edf43f18290ca1 Mon Sep 17 00:00:00 2001
From: Simon Goldschmidt <goldsimon@gmx.de>
Date: Tue, 11 Mar 2014 20:53:44 +0100
Subject: [PATCH] fixed bug #35928 BSD sockets functions must set errno for
 POSIX-compliance (patch by Mason)

---
 CHANGELOG              | 4 ++++
 src/api/sockets.c      | 6 +++---
 src/include/lwip/opt.h | 7 +++++++
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 61c5862a..c932ba07 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -96,6 +96,10 @@ HISTORY
 
  ++ Bugfixes:
 
+  2014-03-11: Simon Goldschmidt (patch by Mason)
+  * opt.h, sockets.c: fixed bug #35928 BSD sockets functions must set errno for
+    POSIX-compliance
+
   2014-02-27: Simon Goldschmidt
   * dhcp.c: fixed bug #40303 DHCP xid renewed when sending a DHCPREQUEST
 
diff --git a/src/api/sockets.c b/src/api/sockets.c
index afa30f05..19edfc57 100644
--- a/src/api/sockets.c
+++ b/src/api/sockets.c
@@ -223,13 +223,13 @@ static const int err_to_errno_table[] = {
   ((unsigned)(-(err)) < ERR_TO_ERRNO_TABLE_SIZE ? \
     err_to_errno_table[-(err)] : EIO)
 
-#ifdef ERRNO
+#if LWIP_SOCKET_SET_ERRNO
 #ifndef set_errno
 #define set_errno(err) do { if (err) { errno = (err); } } while(0)
 #endif
-#else /* ERRNO */
+#else /* LWIP_SOCKET_SET_ERRNO */
 #define set_errno(err)
-#endif /* ERRNO */
+#endif /* LWIP_SOCKET_SET_ERRNO */
 
 #define sock_set_errno(sk, e) do { \
   sk->err = (e); \
diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index ccb0aa05..7db6b4ad 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -1493,6 +1493,13 @@
 #define LWIP_SOCKET                     1
 #endif
 
+/* LWIP_SOCKET_SET_ERRNO==1: Set errno when socket functions cannot complete
+ * successfully, as required by POSIX. Default is POSIX-compliant.
+ */
+#ifndef LWIP_SOCKET_SET_ERRNO
+#define LWIP_SOCKET_SET_ERRNO           1
+#endif
+
 /**
  * LWIP_COMPAT_SOCKETS==1: Enable BSD-style sockets functions names.
  * (only used if you use sockets.c)