inet: Pass flowi to ->queue_xmit().

This allows us to acquire the exact route keying information from the
protocol, however that might be managed.

It handles all of the possibilities, from the simplest case of storing
the key in inet->cork.fl to the more complex setup SCTP has where
individual transports determine the flow.

Signed-off-by: David S. Miller <[e-mail]>

include/net/inet6_connection_sock.h

···
 
 extern void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
 
-extern int inet6_csk_xmit(struct sk_buff *skb);
+extern int inet6_csk_xmit(struct sk_buff *skb, struct flowi *fl);
 #endif /* _INET6_CONNECTION_SOCK_H */

include/net/inet_connection_sock.h

···
  * (i.e. things that depend on the address family)
  */
 struct inet_connection_sock_af_ops {
-	int	    (*queue_xmit)(struct sk_buff *skb);
+	int	    (*queue_xmit)(struct sk_buff *skb, struct flowi *fl);
 	void	    (*send_check)(struct sock *sk, struct sk_buff *skb);
 	int	    (*rebuild_header)(struct sock *sk);
 	int	    (*conn_request)(struct sock *sk, struct sk_buff *skb);

include/net/ip.h

···
 extern void		ip_send_check(struct iphdr *ip);
 extern int		__ip_local_out(struct sk_buff *skb);
 extern int		ip_local_out(struct sk_buff *skb);
-extern int		ip_queue_xmit(struct sk_buff *skb);
+extern int		ip_queue_xmit(struct sk_buff *skb, struct flowi *fl);
 extern void		ip_init(void);
 extern int		ip_append_data(struct sock *sk,
 				       int getfrag(void *from, char *to, int offset, int len,

net/dccp/output.c

···
 static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
 {
 	if (likely(skb != NULL)) {
-		const struct inet_sock *inet = inet_sk(sk);
+		struct inet_sock *inet = inet_sk(sk);
 		const struct inet_connection_sock *icsk = inet_csk(sk);
 		struct dccp_sock *dp = dccp_sk(sk);
 		struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
···
 
 		DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
 
-		err = icsk->icsk_af_ops->queue_xmit(skb);
+		err = icsk->icsk_af_ops->queue_xmit(skb, &inet->cork.fl);
 		return net_xmit_eval(err);
 	}
 	return -ENOBUFS;

net/ipv4/ip_output.c

···
 			    !(IPCB(skb)->flags & IPSKB_REROUTED));
 }
 
-int ip_queue_xmit(struct sk_buff *skb)
+int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl)
 {
 	struct sock *sk = skb->sk;
 	struct inet_sock *inet = inet_sk(sk);
···
 		goto packet_routed;
 
 	/* Make sure we can route this packet. */
-	fl4 = &inet->cork.fl.u.ip4;
+	fl4 = &fl->u.ip4;
 	rt = (struct rtable *)__sk_dst_check(sk, 0);
 	if (rt == NULL) {
 		__be32 daddr;

net/ipv4/tcp_output.c

···
 		TCP_ADD_STATS(sock_net(sk), TCP_MIB_OUTSEGS,
 			      tcp_skb_pcount(skb));
 
-	err = icsk->icsk_af_ops->queue_xmit(skb);
+	err = icsk->icsk_af_ops->queue_xmit(skb, &inet->cork.fl);
 	if (likely(err <= 0))
 		return err;
 

net/ipv6/inet6_connection_sock.c

···
 	return dst;
 }
 
-int inet6_csk_xmit(struct sk_buff *skb)
+int inet6_csk_xmit(struct sk_buff *skb, struct flowi *fl_unused)
 {
 	struct sock *sk = skb->sk;
 	struct inet_sock *inet = inet_sk(sk);

net/l2tp/l2tp_core.c

···
 }
 
 static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb,
-			  size_t data_len)
+			  struct flowi *fl, size_t data_len)
 {
 	struct l2tp_tunnel *tunnel = session->tunnel;
 	unsigned int len = skb->len;
···
 
 	/* Queue the packet to IP for output */
 	skb->local_df = 1;
-	error = ip_queue_xmit(skb);
+	error = ip_queue_xmit(skb, fl);
 
 	/* Update stats */
 	if (error >= 0) {
···
 	int data_len = skb->len;
 	struct l2tp_tunnel *tunnel = session->tunnel;
 	struct sock *sk = tunnel->sock;
+	struct flowi *fl;
 	struct udphdr *uh;
 	struct inet_sock *inet;
 	__wsum csum;
···
 	skb_dst_drop(skb);
 	skb_dst_set(skb, dst_clone(__sk_dst_get(sk)));
 
+	inet = inet_sk(sk);
+	fl = &inet->cork.fl;
 	switch (tunnel->encap) {
 	case L2TP_ENCAPTYPE_UDP:
 		/* Setup UDP header */
-		inet = inet_sk(sk);
 		__skb_push(skb, sizeof(*uh));
 		skb_reset_transport_header(skb);
 		uh = udp_hdr(skb);
···
 
 	l2tp_skb_set_owner_w(skb, sk);
 
-	l2tp_xmit_core(session, skb, data_len);
+	l2tp_xmit_core(session, skb, fl, data_len);
 out_unlock:
 	bh_unlock_sock(sk);
 

net/l2tp/l2tp_ip.c

···
 	skb_dst_set(skb, dst_clone(&rt->dst));
 
 	/* Queue the packet to IP for output */
-	rc = ip_queue_xmit(skb);
+	rc = ip_queue_xmit(skb, &inet->cork.fl);
 
 error:
 	/* Update stats */

net/sctp/protocol.c

···
 			 IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
 
 	SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
-	return ip_queue_xmit(skb);
+	return ip_queue_xmit(skb, &transport->fl);
 }
 
 static struct sctp_af sctp_af_inet;