ipv4: route non-local sources for raw socket

The raw sockets can provide source address for
routing but their privileges are not considered. We
can provide non-local source address, make sure the
FLOWI_FLAG_ANYSRC flag is set if socket has privileges
for this, i.e. based on hdrincl (IP_HDRINCL) and
transparent flags.
Signed-off-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/inet_sock.h

@@ -238,7 +238,7 @@ static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
 {
 	__u8 flags = 0;
 
-	if (inet_sk(sk)->transparent)
+	if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
 		flags |= FLOWI_FLAG_ANYSRC;
 	if (sk->sk_protocol == IPPROTO_TCP)
 		flags |= FLOWI_FLAG_PRECOW_METRICS;

net/ipv4/raw.c

@@ -563,7 +563,8 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
 			   RT_SCOPE_UNIVERSE,
 			   inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
-			   FLOWI_FLAG_CAN_SLEEP, daddr, saddr, 0, 0);
+			   inet_sk_flowi_flags(sk) | FLOWI_FLAG_CAN_SLEEP,
+			   daddr, saddr, 0, 0);
 
 	if (!inet->hdrincl) {
 		err = raw_probe_proto_opt(&fl4, msg);