[PATCH v2] server: Derive protocol in create_socket if not given

[Robin Ebert]

The protocol entry of a sock structure should not be 0 if either SOCK_STREAM or SOCK_DGRAM are used
because this leads to an invalid behaviour of
ws2_32's WS_getsockopt(..., SOL_SOCKET, SO_PROTOCOL_INFOW, ..., ...)

Signed-off-by: Robin Ebert <ebertrobin2002(a)gmail.com>
---
 server/sock.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/server/sock.c b/server/sock.c
index 1a53ce4..c37624b 100644
--- a/server/sock.c
+++ b/server/sock.c
@@ -38,6 +38,9 @@
 #ifdef HAVE_SYS_SOCKET_H
 # include <sys/socket.h>
 #endif
+#ifdef HAVE_NETINET_IN_H
+# include <netinet/in.h>
+#endif
 #ifdef HAVE_SYS_IOCTL_H
 #include <sys/ioctl.h>
 #endif
@@ -659,6 +662,7 @@ static struct object *create_socket( int family, int type, int protocol, unsigne
 {
     struct sock *sock;
     int sockfd;
+    int proto, protolen;
 
     sockfd = socket( family, type, protocol );
     if (sockfd == -1)
@@ -676,7 +680,19 @@ static struct object *create_socket( int family, int type, int protocol, unsigne
     init_sock( sock );
     sock->state  = (type != SOCK_STREAM) ? (FD_READ|FD_WRITE) : 0;
     sock->flags  = flags;
-    sock->proto  = protocol;
+    if(!protocol)
+    {
+        /* if protocol is 0 get it from the kernel */
+        protolen = sizeof(int);
+        if(getsockopt(sockfd, SOL_SOCKET, SO_PROTOCOL, &proto, &protolen))
+        {
+            release_object( sock );
+            return NULL;
+        }
+        sock->proto = proto;
+    }
+    else
+        sock->proto  = protocol;
     sock->type   = type;
     sock->family = family;
 
-- 
2.20.1