Hi Christian,

I attach the first attempt on SO_REUSEPORT. The patch is available
either at https://github.com/foxik/libmicrohttpd/commit/9ce9422742e10458f87275ea202a982e00c2b88c
or attached. (It is against the version with
MHD_DAEMON_OPTION_CURRENT_CONNECTIONS, but I can rebase it to current
SVN HEAD if you want.)

It seems that a reasonably multiplatform way of detecting SO_REUSEPORT is
  #ifdef SO_REPOSEPORT
which is used for example by Perl. For SO_EXCLUSIVEADDRUSE, the same
strategy seems to work too, according to Windows SDK headers and MinGW
WinAPI headers.

The current patch adds an option to allowing/disallowing address:port
reuse. One remark:
- currently both nonexisting SO_xxx and setsockopt failure are fatal and
  MHD_start_daemon fails. That may be too harsh -- maybe the
  MHD_OPTION_LISTENING_ADDRESS_REUSE should be only a hint.

  Nevertheless, as one can freely not use
  MHD_OPTION_LISTENING_ADDRESS_REUSE option, I chose the "fail on error"
  behaviour.

Thanks,
cheers,
Milan Straka

Original patch modified to get rid of some redundant USE_DEBUG
checks, fix indentation, and #ifndef SO_REUSEPORT on Linux,
we try be #defining it to 15 ourselves.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/microhttpd/connection_https.c b/src/microhttpd/connection_https.c
index b566d83c..0d7d5980 100644
--- a/src/microhttpd/connection_https.c
+++ b/src/microhttpd/connection_https.c
@@ -134,8 +134,10 @@ MHD_tls_connection_handle_idle (struct MHD_Connection *connection)
   unsigned int timeout;
 
 #if DEBUG_STATES
-  MHD_DLOG (connection->daemon, "%s: state: %s\n",
-            __FUNCTION__, MHD_state_to_string (connection->state));
+  MHD_DLOG (connection->daemon,
+            "%s: state: %s\n",
+            __FUNCTION__,
+            MHD_state_to_string (connection->state));
 #endif
   timeout = connection->connection_timeout;
   if ( (timeout != 0) && (timeout <= (MHD_monotonic_time() - connection->last_activity)))