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>

3 files changed, 8 insertions, 6 deletions

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 2cf48ba0dbb1..a0a36c9e6cce 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 b963f35c65f6..05ea7440d9e5 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 36bcc00654d3..c0e88c16d088 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 */