ipv4: Show that ip_send_reply() is purely unicast routine.

Rename it to ip_send_unicast_reply() and add explicit 'saddr'
argument.

This removed one of the few users of rt->rt_spec_dst.
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip.h

@@ -158,8 +158,9 @@ static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
 	return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
 }
 
-void ip_send_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr,
-		   const struct ip_reply_arg *arg, unsigned int len);
+void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr,
+			   __be32 saddr, const struct ip_reply_arg *arg,
+			   unsigned int len);
 
 struct ipv4_config {
 	int	log_martians;

net/ipv4/ip_output.c

@@ -1459,13 +1459,14 @@ static int ip_reply_glue_bits(void *dptr, char *to, int offset,
 
 /*
  *	Generic function to send a packet as reply to another packet.
- *	Used to send TCP resets so far. ICMP should use this function too.
+ *	Used to send TCP resets so far.
  *
  *	Should run single threaded per socket because it uses the sock
  *     	structure to pass arguments.
  */
-void ip_send_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr,
-		   const struct ip_reply_arg *arg, unsigned int len)
+void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr,
+			   __be32 saddr, const struct ip_reply_arg *arg,
+			   unsigned int len)
 {
 	struct inet_sock *inet = inet_sk(sk);
 	struct ip_options_data replyopts;
@@ -1491,7 +1492,7 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr,
 			   RT_TOS(arg->tos),
 			   RT_SCOPE_UNIVERSE, sk->sk_protocol,
 			   ip_reply_arg_flowi_flags(arg),
-			   daddr, rt->rt_spec_dst,
+			   daddr, saddr,
 			   tcp_hdr(skb)->source, tcp_hdr(skb)->dest);
 	security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
 	rt = ip_route_output_key(sock_net(sk), &fl4);

net/ipv4/tcp_ipv4.c

@@ -698,8 +698,8 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
 
 	net = dev_net(skb_dst(skb)->dev);
 	arg.tos = ip_hdr(skb)->tos;
-	ip_send_reply(net->ipv4.tcp_sock, skb, ip_hdr(skb)->saddr,
-		      &arg, arg.iov[0].iov_len);
+	ip_send_unicast_reply(net->ipv4.tcp_sock, skb, ip_hdr(skb)->saddr,
+			      ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len);
 
 	TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 	TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
@@ -781,8 +781,8 @@ static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
 	if (oif)
 		arg.bound_dev_if = oif;
 	arg.tos = tos;
-	ip_send_reply(net->ipv4.tcp_sock, skb, ip_hdr(skb)->saddr,
-		      &arg, arg.iov[0].iov_len);
+	ip_send_unicast_reply(net->ipv4.tcp_sock, skb, ip_hdr(skb)->saddr,
+			      ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len);
 
 	TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 }