qemu-sockets: Fix compiler warning (regression for MinGW)

setsockopt needs a type cast for MinGW. That type cast is missing in
a recent commit which results in a compiler warning.

Like for other socket related functions which have the same problem,
we add a 'qemu_setsockopt' macro which provides that type cast where
needed and use the new macro to avoid the warning.

A 'qemu_getsockopt' is also added and can be used for future
modifications.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>

qemu-common.h

@@ -223,11 +223,19 @@ int qemu_pipe(int pipefd[2]);
 #endif
 
 #ifdef _WIN32
-/* MinGW needs a type cast for the 'buf' argument. */
+/* MinGW needs type casts for the 'buf' and 'optval' arguments. */
+#define qemu_getsockopt(sockfd, level, optname, optval, optlen) \
+    getsockopt(sockfd, level, optname, (void *)optval, optlen)
+#define qemu_setsockopt(sockfd, level, optname, optval, optlen) \
+    setsockopt(sockfd, level, optname, (const void *)optval, optlen)
 #define qemu_recv(sockfd, buf, len, flags) recv(sockfd, (void *)buf, len, flags)
 #define qemu_sendto(sockfd, buf, len, flags, destaddr, addrlen) \
     sendto(sockfd, (const void *)buf, len, flags, destaddr, addrlen)
 #else
+#define qemu_getsockopt(sockfd, level, optname, optval, optlen) \
+    getsockopt(sockfd, level, optname, optval, optlen)
+#define qemu_setsockopt(sockfd, level, optname, optval, optlen) \
+    setsockopt(sockfd, level, optname, optval, optlen)
 #define qemu_recv(sockfd, buf, len, flags) recv(sockfd, buf, len, flags)
 #define qemu_sendto(sockfd, buf, len, flags, destaddr, addrlen) \
     sendto(sockfd, buf, len, flags, destaddr, addrlen)

qemu-sockets.c

@@ -282,7 +282,7 @@ static int inet_connect_addr(struct addrinfo *addr, bool *in_progress,
                 inet_strfamily(addr->ai_family), strerror(errno));
         return -1;
     }
-    setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+    qemu_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
     if (connect_state != NULL) {
         socket_set_nonblock(sock);
     }