net: skb->rtable accessor

Define skb_rtable(const struct sk_buff *skb) accessor to get rtable from skb

Delete skb->rtable field

Setting rtable is not allowed, just set dst instead as rtable is an alias.

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

1 files changed, 22 insertions, 15 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 28205e5bfa9b..f20060ac2f09 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1064,7 +1064,8 @@ work_done:
 out:    return 0;
 }
 
-static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp)
+static int rt_intern_hash(unsigned hash, struct rtable *rt,
+                          struct rtable **rp, struct sk_buff *skb)
 {
         struct rtable   *rth, **rthp;
         unsigned long   now;
@@ -1114,7 +1115,10 @@ restart:
                         spin_unlock_bh(rt_hash_lock_addr(hash));
 
                         rt_drop(rt);
-                        *rp = rth;
+                        if (rp)
+                                *rp = rth;
+                        else
+                                skb->dst = &rth->u.dst;
                         return 0;
                 }
 
@@ -1210,7 +1214,10 @@ restart:
         rcu_assign_pointer(rt_hash_table[hash].chain, rt);
 
         spin_unlock_bh(rt_hash_lock_addr(hash));
-        *rp = rt;
+        if (rp)
+                *rp = rt;
+        else
+                skb->dst = &rt->u.dst;
         return 0;
 }
 
@@ -1407,7 +1414,7 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
                                                         &netevent);
 
                                 rt_del(hash, rth);
-                                if (!rt_intern_hash(hash, rt, &rt))
+                                if (!rt_intern_hash(hash, rt, &rt, NULL))
                                         ip_rt_put(rt);
                                 goto do_next;
                         }
@@ -1473,7 +1480,7 @@ static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
 
 void ip_rt_send_redirect(struct sk_buff *skb)
 {
-        struct rtable *rt = skb->rtable;
+        struct rtable *rt = skb_rtable(skb);
         struct in_device *in_dev = in_dev_get(rt->u.dst.dev);
 
         if (!in_dev)
@@ -1521,7 +1528,7 @@ out:
 
 static int ip_error(struct sk_buff *skb)
 {
-        struct rtable *rt = skb->rtable;
+        struct rtable *rt = skb_rtable(skb);
         unsigned long now;
         int code;
 
@@ -1698,7 +1705,7 @@ static void ipv4_link_failure(struct sk_buff *skb)
 
         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
 
-        rt = skb->rtable;
+        rt = skb_rtable(skb);
         if (rt)
                 dst_set_expires(&rt->u.dst, 0);
 }
@@ -1858,7 +1865,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 
         in_dev_put(in_dev);
         hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
-        return rt_intern_hash(hash, rth, &skb->rtable);
+        return rt_intern_hash(hash, rth, NULL, skb);
 
 e_nobufs:
         in_dev_put(in_dev);
@@ -2019,7 +2026,7 @@ static int ip_mkroute_input(struct sk_buff *skb,
         /* put it into the cache */
         hash = rt_hash(daddr, saddr, fl->iif,
                        rt_genid(dev_net(rth->u.dst.dev)));
-        return rt_intern_hash(hash, rth, &skb->rtable);
+        return rt_intern_hash(hash, rth, NULL, skb);
 }
 
 /*
@@ -2175,7 +2182,7 @@ local_input:
         }
         rth->rt_type    = res.type;
         hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net));
-        err = rt_intern_hash(hash, rth, &skb->rtable);
+        err = rt_intern_hash(hash, rth, NULL, skb);
         goto done;
 
 no_route:
@@ -2244,7 +2251,7 @@ int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
                         dst_use(&rth->u.dst, jiffies);
                         RT_CACHE_STAT_INC(in_hit);
                         rcu_read_unlock();
-                        skb->rtable = rth;
+                        skb->dst = &rth->u.dst;
                         return 0;
                 }
                 RT_CACHE_STAT_INC(in_hlist_search);
@@ -2420,7 +2427,7 @@ static int ip_mkroute_output(struct rtable **rp,
         if (err == 0) {
                 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif,
                                rt_genid(dev_net(dev_out)));
-                err = rt_intern_hash(hash, rth, rp);
+                err = rt_intern_hash(hash, rth, rp, NULL);
         }
 
         return err;
@@ -2763,7 +2770,7 @@ static int rt_fill_info(struct net *net,
                         struct sk_buff *skb, u32 pid, u32 seq, int event,
                         int nowait, unsigned int flags)
 {
-        struct rtable *rt = skb->rtable;
+        struct rtable *rt = skb_rtable(skb);
         struct rtmsg *r;
         struct nlmsghdr *nlh;
         long expires;
@@ -2907,7 +2914,7 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void
                 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
                 local_bh_enable();
 
-                rt = skb->rtable;
+                rt = skb_rtable(skb);
                 if (err == 0 && rt->u.dst.error)
                         err = -rt->u.dst.error;
         } else {
@@ -2927,7 +2934,7 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void
         if (err)
                 goto errout_free;
 
-        skb->rtable = rt;
+        skb->dst = &rt->u.dst;
         if (rtm->rtm_flags & RTM_F_NOTIFY)
                 rt->rt_flags |= RTCF_NOTIFY;