[IPV4,IPV6]: Share cork.rt between IPv4 and IPv6.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

include/linux/ipv6.h

@@ -315,7 +315,6 @@ struct ipv6_pinfo {
 	struct sk_buff		*pktoptions;
 	struct {
 		struct ipv6_txoptions *opt;
-		struct rt6_info	*rt;
 		int hop_limit;
 		int tclass;
 	} cork;

include/net/inet_sock.h

@@ -136,7 +136,7 @@ struct inet_sock {
 		unsigned int		flags;
 		unsigned int		fragsize;
 		struct ip_options	*opt;
-		struct rtable		*rt;
+		struct dst_entry	*dst;
 		int			length; /* Total length of all frames */
 		__be32			addr;
 		struct flowi		fl;

net/ipv4/ip_output.c

@@ -825,7 +825,7 @@ int ip_append_data(struct sock *sk,
 		inet->cork.fragsize = mtu = inet->pmtudisc == IP_PMTUDISC_PROBE ?
 					    rt->u.dst.dev->mtu :
 					    dst_mtu(rt->u.dst.path);
-		inet->cork.rt = rt;
+		inet->cork.dst = &rt->u.dst;
 		inet->cork.length = 0;
 		sk->sk_sndmsg_page = NULL;
 		sk->sk_sndmsg_off = 0;
@@ -834,7 +834,7 @@ int ip_append_data(struct sock *sk,
 			transhdrlen += exthdrlen;
 		}
 	} else {
-		rt = inet->cork.rt;
+		rt = (struct rtable *)inet->cork.dst;
 		if (inet->cork.flags & IPCORK_OPT)
 			opt = inet->cork.opt;
 
@@ -1083,7 +1083,7 @@ ssize_t	ip_append_page(struct sock *sk, struct page *page,
 	if (skb_queue_empty(&sk->sk_write_queue))
 		return -EINVAL;
 
-	rt = inet->cork.rt;
+	rt = (struct rtable *)inet->cork.dst;
 	if (inet->cork.flags & IPCORK_OPT)
 		opt = inet->cork.opt;
 
@@ -1208,10 +1208,8 @@ static void ip_cork_release(struct inet_sock *inet)
 	inet->cork.flags &= ~IPCORK_OPT;
 	kfree(inet->cork.opt);
 	inet->cork.opt = NULL;
-	if (inet->cork.rt) {
-		ip_rt_put(inet->cork.rt);
-		inet->cork.rt = NULL;
-	}
+	dst_release(inet->cork.dst);
+	inet->cork.dst = NULL;
 }
 
 /*
@@ -1224,7 +1222,7 @@ int ip_push_pending_frames(struct sock *sk)
 	struct sk_buff **tail_skb;
 	struct inet_sock *inet = inet_sk(sk);
 	struct ip_options *opt = NULL;
-	struct rtable *rt = inet->cork.rt;
+	struct rtable *rt = (struct rtable *)inet->cork.dst;
 	struct iphdr *iph;
 	__be16 df = 0;
 	__u8 ttl;

net/ipv6/ip6_output.c

@@ -1115,7 +1115,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
 			/* need source address above miyazawa*/
 		}
 		dst_hold(&rt->u.dst);
-		np->cork.rt = rt;
+		inet->cork.dst = &rt->u.dst;
 		inet->cork.fl = *fl;
 		np->cork.hop_limit = hlimit;
 		np->cork.tclass = tclass;
@@ -1136,7 +1136,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
 		length += exthdrlen;
 		transhdrlen += exthdrlen;
 	} else {
-		rt = np->cork.rt;
+		rt = (struct rt6_info *)inet->cork.dst;
 		fl = &inet->cork.fl;
 		if (inet->cork.flags & IPCORK_OPT)
 			opt = np->cork.opt;
@@ -1381,9 +1381,9 @@ static void ip6_cork_release(struct inet_sock *inet, struct ipv6_pinfo *np)
 	inet->cork.flags &= ~IPCORK_OPT;
 	kfree(np->cork.opt);
 	np->cork.opt = NULL;
-	if (np->cork.rt) {
-		dst_release(&np->cork.rt->u.dst);
-		np->cork.rt = NULL;
+	if (inet->cork.dst) {
+		dst_release(inet->cork.dst);
+		inet->cork.dst = NULL;
 		inet->cork.flags &= ~IPCORK_ALLFRAG;
 	}
 	memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
@@ -1398,7 +1398,7 @@ int ip6_push_pending_frames(struct sock *sk)
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	struct ipv6hdr *hdr;
 	struct ipv6_txoptions *opt = np->cork.opt;
-	struct rt6_info *rt = np->cork.rt;
+	struct rt6_info *rt = (struct rt6_info *)inet->cork.dst;
 	struct flowi *fl = &inet->cork.fl;
 	unsigned char proto = fl->proto;
 	int err = 0;