net: skb->dst accessors

Define three accessors to get/set dst attached to a skb

struct dst_entry *skb_dst(const struct sk_buff *skb)

void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)

void skb_dst_drop(struct sk_buff *skb)
This one should replace occurrences of :
dst_release(skb->dst)
skb->dst = NULL;

Delete skb->dst field

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

69 files changed, 354 insertions, 344 deletions

diff --git a/net/atm/br2684.c b/net/atm/br2684.c
index bfa8fa9894f..2912665fc58 100644
--- a/net/atm/br2684.c
+++ b/net/atm/br2684.c
@@ -228,7 +228,7 @@ static int br2684_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	struct br2684_dev *brdev = BRPRIV(dev);
 	struct br2684_vcc *brvcc;
 
-	pr_debug("br2684_start_xmit, skb->dst=%p\n", skb->dst);
+	pr_debug("br2684_start_xmit, skb_dst(skb)=%p\n", skb_dst(skb));
 	read_lock(&devs_lock);
 	brvcc = pick_outgoing_vcc(skb, brdev);
 	if (brvcc == NULL) {
diff --git a/net/atm/clip.c b/net/atm/clip.c
index fb7623c080f..e65a3b1477f 100644
--- a/net/atm/clip.c
+++ b/net/atm/clip.c
@@ -369,16 +369,16 @@ static int clip_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	unsigned long flags;
 
 	pr_debug("clip_start_xmit (skb %p)\n", skb);
-	if (!skb->dst) {
-		printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
+	if (!skb_dst(skb)) {
+		printk(KERN_ERR "clip_start_xmit: skb_dst(skb) == NULL\n");
 		dev_kfree_skb(skb);
 		dev->stats.tx_dropped++;
 		return 0;
 	}
-	if (!skb->dst->neighbour) {
+	if (!skb_dst(skb)->neighbour) {
 #if 0
-		skb->dst->neighbour = clip_find_neighbour(skb->dst, 1);
-		if (!skb->dst->neighbour) {
+		skb_dst(skb)->neighbour = clip_find_neighbour(skb_dst(skb), 1);
+		if (!skb_dst(skb)->neighbour) {
 			dev_kfree_skb(skb);	/* lost that one */
 			dev->stats.tx_dropped++;
 			return 0;
@@ -389,7 +389,7 @@ static int clip_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		dev->stats.tx_dropped++;
 		return 0;
 	}
-	entry = NEIGH2ENTRY(skb->dst->neighbour);
+	entry = NEIGH2ENTRY(skb_dst(skb)->neighbour);
 	if (!entry->vccs) {
 		if (time_after(jiffies, entry->expires)) {
 			/* should be resolved */
@@ -406,7 +406,7 @@ static int clip_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	}
 	pr_debug("neigh %p, vccs %p\n", entry, entry->vccs);
 	ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
-	pr_debug("using neighbour %p, vcc %p\n", skb->dst->neighbour, vcc);
+	pr_debug("using neighbour %p, vcc %p\n", skb_dst(skb)->neighbour, vcc);
 	if (entry->vccs->encap) {
 		void *here;
 
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index e0ceb66a9ec..d22f611e400 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -242,7 +242,7 @@ static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb)
 		return 0;
 	}
 	dst_hold(&rt->u.dst);
-	skb->dst = &rt->u.dst;
+	skb_dst_set(skb, &rt->u.dst);
 
 	skb->dev = nf_bridge->physindev;
 	nf_bridge_push_encap_header(skb);
@@ -322,7 +322,7 @@ static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb)
 
 	skb->dev = bridge_parent(skb->dev);
 	if (skb->dev) {
-		struct dst_entry *dst = skb->dst;
+		struct dst_entry *dst = skb_dst(skb);
 
 		nf_bridge_pull_encap_header(skb);
 
@@ -375,7 +375,7 @@ static int br_nf_pre_routing_finish(struct sk_buff *skb)
 				/* - Bridged-and-DNAT'ed traffic doesn't
 				 *   require ip_forwarding. */
 				if (((struct dst_entry *)rt)->dev == dev) {
-					skb->dst = (struct dst_entry *)rt;
+					skb_dst_set(skb, (struct dst_entry *)rt);
 					goto bridged_dnat;
 				}
 				/* we are sure that forwarding is disabled, so printing
@@ -389,7 +389,7 @@ free_skb:
 			kfree_skb(skb);
 			return 0;
 		} else {
-			if (skb->dst->dev == dev) {
+			if (skb_dst(skb)->dev == dev) {
 bridged_dnat:
 				/* Tell br_nf_local_out this is a
 				 * bridged frame */
@@ -412,7 +412,7 @@ bridged_dnat:
 			return 0;
 		}
 		dst_hold(&rt->u.dst);
-		skb->dst = &rt->u.dst;
+		skb_dst_set(skb, &rt->u.dst);
 	}
 
 	skb->dev = nf_bridge->physindev;
@@ -633,10 +633,8 @@ static unsigned int br_nf_local_in(unsigned int hook, struct sk_buff *skb,
 {
 	struct rtable *rt = skb_rtable(skb);
 
-	if (rt && rt == bridge_parent_rtable(in)) {
-		dst_release(&rt->u.dst);
-		skb->dst = NULL;
-	}
+	if (rt && rt == bridge_parent_rtable(in))
+		skb_dst_drop(skb);
 
 	return NF_ACCEPT;
 }
@@ -851,7 +849,7 @@ static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff *skb,
 		return NF_ACCEPT;
 
 #ifdef CONFIG_NETFILTER_DEBUG
-	if (skb->dst == NULL) {
+	if (skb_dst(skb) == NULL) {
 		printk(KERN_INFO "br_netfilter post_routing: skb->dst == NULL\n");
 		goto print_error;
 	}
diff --git a/net/core/dev.c b/net/core/dev.c
index e2fcc5f1017..34b49a6a22f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1693,10 +1693,9 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
 		 * If device doesnt need skb->dst, release it right now while
 		 * its hot in this cpu cache
 		 */
-		if ((dev->priv_flags & IFF_XMIT_DST_RELEASE) && skb->dst) {
-			dst_release(skb->dst);
-			skb->dst = NULL;
-		}
+		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
+			skb_dst_drop(skb);
+
 		rc = ops->ndo_start_xmit(skb, dev);
 		if (rc == 0)
 			txq_trans_update(txq);
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index a1cbce7fdae..c54229befcf 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1088,8 +1088,8 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
 			struct neighbour *n1 = neigh;
 			write_unlock_bh(&neigh->lock);
 			/* On shaper/eql skb->dst->neighbour != neigh :( */
-			if (skb->dst && skb->dst->neighbour)
-				n1 = skb->dst->neighbour;
+			if (skb_dst(skb) && skb_dst(skb)->neighbour)
+				n1 = skb_dst(skb)->neighbour;
 			n1->output(skb);
 			write_lock_bh(&neigh->lock);
 		}
@@ -1182,7 +1182,7 @@ EXPORT_SYMBOL(neigh_compat_output);
 
 int neigh_resolve_output(struct sk_buff *skb)
 {
-	struct dst_entry *dst = skb->dst;
+	struct dst_entry *dst = skb_dst(skb);
 	struct neighbour *neigh;
 	int rc = 0;
 
@@ -1229,7 +1229,7 @@ EXPORT_SYMBOL(neigh_resolve_output);
 int neigh_connected_output(struct sk_buff *skb)
 {
 	int err;
-	struct dst_entry *dst = skb->dst;
+	struct dst_entry *dst = skb_dst(skb);
 	struct neighbour *neigh = dst->neighbour;
 	struct net_device *dev = neigh->dev;
 
@@ -1298,8 +1298,7 @@ void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
 		if (time_before(tbl->proxy_timer.expires, sched_next))
 			sched_next = tbl->proxy_timer.expires;
 	}
-	dst_release(skb->dst);
-	skb->dst = NULL;
+	skb_dst_drop(skb);
 	dev_hold(skb->dev);
 	__skb_queue_tail(&tbl->proxy_queue, skb);
 	mod_timer(&tbl->proxy_timer, sched_next);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 8e815e685f2..6adf19ec95c 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -381,7 +381,7 @@ static void kfree_skbmem(struct sk_buff *skb)
 
 static void skb_release_head_state(struct sk_buff *skb)
 {
-	dst_release(skb->dst);
+	skb_dst_drop(skb);
 #ifdef CONFIG_XFRM
 	secpath_put(skb->sp);
 #endif
@@ -521,7 +521,7 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
 	new->transport_header	= old->transport_header;
 	new->network_header	= old->network_header;
 	new->mac_header		= old->mac_header;
-	new->dst		= dst_clone(old->dst);
+	skb_dst_set(new, dst_clone(skb_dst(old)));
 #ifdef CONFIG_XFRM
 	new->sp			= secpath_get(old->sp);
 #endif
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 2cf48ba0dbb..a0a36c9e6cc 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -507,7 +507,7 @@ static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
 	const struct iphdr *rxiph;
 	struct sk_buff *skb;
 	struct dst_entry *dst;
-	struct net *net = dev_net(rxskb->dst->dev);
+	struct net *net = dev_net(skb_dst(rxskb)->dev);
 	struct sock *ctl_sk = net->dccp.v4_ctl_sk;
 
 	/* Never send a reset in response to a reset. */
@@ -528,7 +528,7 @@ static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
 	rxiph = ip_hdr(rxskb);
 	dccp_hdr(skb)->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
 								 rxiph->daddr);
-	skb->dst = dst_clone(dst);
+	skb_dst_set(skb, dst_clone(dst));
 
 	bh_lock_sock(ctl_sk);
 	err = ip_build_and_send_pkt(skb, ctl_sk,
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index b963f35c65f..05ea7440d9e 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -314,8 +314,9 @@ static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
 	struct ipv6hdr *rxip6h;
 	struct sk_buff *skb;
 	struct flowi fl;
-	struct net *net = dev_net(rxskb->dst->dev);
+	struct net *net = dev_net(skb_dst(rxskb)->dev);
 	struct sock *ctl_sk = net->dccp.v6_ctl_sk;
+	struct dst_entry *dst;
 
 	if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
 		return;
@@ -342,8 +343,9 @@ static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
 	security_skb_classify_flow(rxskb, &fl);
 
 	/* sk = NULL, but it is safe for now. RST socket required. */
-	if (!ip6_dst_lookup(ctl_sk, &skb->dst, &fl)) {
-		if (xfrm_lookup(net, &skb->dst, &fl, NULL, 0) >= 0) {
+	if (!ip6_dst_lookup(ctl_sk, &dst, &fl)) {
+		if (xfrm_lookup(net, &dst, &fl, NULL, 0) >= 0) {
+			skb_dst_set(skb, dst);
 			ip6_xmit(ctl_sk, skb, &fl, NULL, 0);
 			DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
 			DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
diff --git a/net/dccp/output.c b/net/dccp/output.c
index 36bcc00654d..c0e88c16d08 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -350,7 +350,7 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
 	/* Reserve space for headers. */
 	skb_reserve(skb, sk->sk_prot->max_header);
 
-	skb->dst = dst_clone(dst);
+	skb_dst_set(skb, dst_clone(dst));
 
 	dreq = dccp_rsk(req);
 	if (inet_rsk(req)->acked)	/* increase ISS upon retransmission */
diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c
index bccb3887773..a5e3a593e47 100644
--- a/net/decnet/af_decnet.c
+++ b/net/decnet/af_decnet.c
@@ -1075,6 +1075,7 @@ static int dn_accept(struct socket *sock, struct socket *newsock, int flags)
 	int err = 0;
 	unsigned char type;
 	long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
+	struct dst_entry *dst;
 
 	lock_sock(sk);
 
@@ -1102,8 +1103,9 @@ static int dn_accept(struct socket *sock, struct socket *newsock, int flags)
 	}
 	release_sock(sk);
 
-	dst_release(xchg(&newsk->sk_dst_cache, skb->dst));
-	skb->dst = NULL;
+	dst = skb_dst(skb);
+	dst_release(xchg(&newsk->sk_dst_cache, dst));
+	skb_dst_set(skb, NULL);
 
 	DN_SK(newsk)->state        = DN_CR;
 	DN_SK(newsk)->addrrem      = cb->src_port;
diff --git a/net/decnet/dn_neigh.c b/net/decnet/dn_neigh.c
index 05b5aa05e50..923786bd6d0 100644
--- a/net/decnet/dn_neigh.c
+++ b/net/decnet/dn_neigh.c
@@ -204,7 +204,7 @@ static void dn_short_error_report(struct neighbour *neigh, struct sk_buff *skb)
 
 static int dn_neigh_output_packet(struct sk_buff *skb)
 {
-	struct dst_entry *dst = skb->dst;
+	struct dst_entry *dst = skb_dst(skb);
 	struct dn_route *rt = (struct dn_route *)dst;
 	struct neighbour *neigh = dst->neighbour;
 	struct net_device *dev = neigh->dev;
@@ -224,7 +224,7 @@ static int dn_neigh_output_packet(struct sk_buff *skb)
 
 static int dn_long_output(struct sk_buff *skb)
 {
-	struct dst_entry *dst = skb->dst;
+	struct dst_entry *dst = skb_dst(skb);
 	struct neighbour *neigh = dst->neighbour;
 	struct net_device *dev = neigh->dev;
 	int headroom = dev->hard_header_len + sizeof(struct dn_long_packet) + 3;
@@ -270,7 +270,7 @@ static int dn_long_output(struct sk_buff *skb)
 
 static int dn_short_output(struct sk_buff *skb)
 {
-	struct dst_entry *dst = skb->dst;
+	struct dst_entry *dst = skb_dst(skb);
 	struct neighbour *neigh = dst->neighbour;
 	struct net_device *dev = neigh->dev;
 	int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
@@ -313,7 +313,7 @@ static int dn_short_output(struct sk_buff *skb)
  */
 static int dn_phase3_output(struct sk_buff *skb)
 {
-	struct dst_entry *dst = skb->dst;
+	struct dst_entry *dst = skb_dst(skb);
 	struct neighbour *neigh = dst->neighbour;
 	struct net_device *dev = neigh->dev;
 	int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
diff --git a/net/decnet/dn_nsp_out.c b/net/decnet/dn_nsp_out.c
index da04f459337..a65e929ce76 100644
--- a/net/decnet/dn_nsp_out.c
+++ b/net/decnet/dn_nsp_out.c
@@ -85,7 +85,7 @@ static void dn_nsp_send(struct sk_buff *skb)
 	dst = sk_dst_check(sk, 0);
 	if (dst) {
 try_again:
-		skb->dst = dst;
+		skb_dst_set(skb, dst);
 		dst_output(skb);
 		return;
 	}
@@ -582,7 +582,7 @@ static __inline__ void dn_nsp_do_disc(struct sock *sk, unsigned char msgflg,
 	 * to be able to send disc packets out which have no socket
 	 * associations.
 	 */
-	skb->dst = dst_clone(dst);
+	skb_dst_set(skb, dst_clone(dst));
 	dst_output(skb);
 }
 
@@ -611,7 +611,7 @@ void dn_nsp_return_disc(struct sk_buff *skb, unsigned char msgflg,
 	int ddl = 0;
 	gfp_t gfp = GFP_ATOMIC;
 
-	dn_nsp_do_disc(NULL, msgflg, reason, gfp, skb->dst, ddl,
+	dn_nsp_do_disc(NULL, msgflg, reason, gfp, skb_dst(skb), ddl,
 			NULL, cb->src_port, cb->dst_port);
 }
 
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 0cc4394117d..1d6ca8a98dc 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -678,7 +678,7 @@ out:
 
 static int dn_output(struct sk_buff *skb)
 {
-	struct dst_entry *dst = skb->dst;
+	struct dst_entry *dst = skb_dst(skb);
 	struct dn_route *rt = (struct dn_route *)dst;
 	struct net_device *dev = dst->dev;
 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
@@ -717,7 +717,7 @@ error:
 static int dn_forward(struct sk_buff *skb)
 {
 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
-	struct dst_entry *dst = skb->dst;
+	struct dst_entry *dst = skb_dst(skb);
 	struct dn_dev *dn_db = dst->dev->dn_ptr;
 	struct dn_route *rt;
 	struct neighbour *neigh = dst->neighbour;
@@ -730,7 +730,7 @@ static int dn_forward(struct sk_buff *skb)
 		goto drop;
 
 	/* Ensure that we have enough space for headers */
-	rt = (struct dn_route *)skb->dst;
+	rt = (struct dn_route *)skb_dst(skb);
 	header_len = dn_db->use_long ? 21 : 6;
 	if (skb_cow(skb, LL_RESERVED_SPACE(rt->u.dst.dev)+header_len))
 		goto drop;
@@ -1392,7 +1392,8 @@ make_route:
 		goto e_neighbour;
 
 	hash = dn_hash(rt->fl.fld_src, rt->fl.fld_dst);
-	dn_insert_route(rt, hash, (struct dn_route **)&skb->dst);
+	dn_insert_route(rt, hash, &rt);
+	skb_dst_set(skb, &rt->u.dst);
 
 done:
 	if (neigh)
@@ -1424,7 +1425,7 @@ static int dn_route_input(struct sk_buff *skb)
 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
 	unsigned hash = dn_hash(cb->src, cb->dst);
 
-	if (skb->dst)
+	if (skb_dst(skb))
 		return 0;
 
 	rcu_read_lock();
@@ -1437,7 +1438,7 @@ static int dn_route_input(struct sk_buff *skb)
 		    (rt->fl.iif == cb->iif)) {
 			dst_use(&rt->u.dst, jiffies);
 			rcu_read_unlock();
-			skb->dst = (struct dst_entry *)rt;
+			skb_dst_set(skb, (struct dst_entry *)rt);
 			return 0;
 		}
 	}
@@ -1449,7 +1450,7 @@ static int dn_route_input(struct sk_buff *skb)
 static int dn_rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
 			   int event, int nowait, unsigned int flags)
 {
-	struct dn_route *rt = (struct dn_route *)skb->dst;
+	struct dn_route *rt = (struct dn_route *)skb_dst(skb);
 	struct rtmsg *r;
 	struct nlmsghdr *nlh;
 	unsigned char *b = skb_tail_pointer(skb);
@@ -1554,7 +1555,7 @@ static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void
 		err = dn_route_input(skb);
 		local_bh_enable();
 		memset(cb, 0, sizeof(struct dn_skb_cb));
-		rt = (struct dn_route *)skb->dst;
+		rt = (struct dn_route *)skb_dst(skb);
 		if (!err && -rt->u.dst.error)
 			err = rt->u.dst.error;
 	} else {
@@ -1570,7 +1571,7 @@ static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void
 	skb->dev = NULL;
 	if (err)
 		goto out_free;
-	skb->dst = &rt->u.dst;
+	skb_dst_set(skb, &rt->u.dst);
 	if (rtm->rtm_flags & RTM_F_NOTIFY)
 		rt->rt_flags |= RTCF_NOTIFY;
 
@@ -1622,15 +1623,15 @@ int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
 			rt = rcu_dereference(rt->u.dst.dn_next), idx++) {
 			if (idx < s_idx)
 				continue;
-			skb->dst = dst_clone(&rt->u.dst);
+			skb_dst_set(skb, dst_clone(&rt->u.dst));
 			if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
 					cb->nlh->nlmsg_seq, RTM_NEWROUTE,
 					1, NLM_F_MULTI) <= 0) {
-				dst_release(xchg(&skb->dst, NULL));
+				skb_dst_drop(skb);
 				rcu_read_unlock_bh();
 				goto done;
 			}
-			dst_release(xchg(&skb->dst, NULL));
+			skb_dst_drop(skb);
 		}
 		rcu_read_unlock_bh();
 	}
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 816494f271a..8a3881e28ac 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -468,7 +468,7 @@ int arp_find(unsigned char *haddr, struct sk_buff *skb)
 	__be32 paddr;
 	struct neighbour *n;
 
-	if (!skb->dst) {
+	if (!skb_dst(skb)) {
 		printk(KERN_DEBUG "arp_find is called with dst==NULL\n");
 		kfree_skb(skb);
 		return 1;
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 94f75efae93..97c410e8438 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -591,13 +591,13 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 				goto relookup_failed;
 
 			/* Ugh! */