ipv4: Allow binding to non-local addresses if IP_TRANSPARENT is set

Setting IP_TRANSPARENT is not really useful without allowing non-local
binds for the socket. To make user-space code simpler we allow these
binds even if IP_TRANSPARENT is set but IP_FREEBIND is not.
Signed-off-by: NTóth László Attila <panther@balabit.hu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/af_inet.c

@@ -469,7 +469,7 @@ int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	 */
 	err = -EADDRNOTAVAIL;
 	if (!sysctl_ip_nonlocal_bind &&
-	    !inet->freebind &&
+	    !(inet->freebind || inet->transparent) &&
 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
 	    chk_addr_ret != RTN_LOCAL &&
 	    chk_addr_ret != RTN_MULTICAST &&