ipv4: Maintain redirect and PMTU info in struct rtable again.

Maintaining this in the inetpeer entries was not the right way to do
this at all.

Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 41 insertions, 154 deletions

diff --git a/include/net/inetpeer.h b/include/net/inetpeer.h
index 1119f6f6cdb4..53f464d7cddc 100644
--- a/include/net/inetpeer.h
+++ b/include/net/inetpeer.h
@@ -36,10 +36,6 @@ struct inet_peer {
         u32                     metrics[RTAX_MAX];
         u32                     rate_tokens;    /* rate limiting for ICMP */
         unsigned long           rate_last;
-        unsigned long           pmtu_expires;
-        u32                     pmtu_orig;
-        u32                     pmtu_learned;
-        struct inetpeer_addr_base redirect_learned;
         union {
                 struct list_head        gc_list;
                 struct rcu_head     gc_rcu;
diff --git a/include/net/route.h b/include/net/route.h
index 635d7a99d199..c27449466d18 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -65,7 +65,7 @@ struct rtable {
         __be32                  rt_gateway;
 
         /* Miscellaneous cached information */
-        u32                     rt_peer_genid;
+        u32                     rt_pmtu;
         unsigned long           _peer; /* long-living peer info */
         struct fib_info         *fi; /* for client ref to shared metrics */
 };
diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c
index f457bcb41350..e1e0a4e8fd34 100644
--- a/net/ipv4/inetpeer.c
+++ b/net/ipv4/inetpeer.c
@@ -511,9 +511,6 @@ relookup:
                 p->metrics[RTAX_LOCK-1] = INETPEER_METRICS_NEW;
                 p->rate_tokens = 0;
                 p->rate_last = 0;
-                p->pmtu_expires = 0;
-                p->pmtu_orig = 0;
-                memset(&p->redirect_learned, 0, sizeof(p->redirect_learned));
                 INIT_LIST_HEAD(&p->gc_list);
 
                 /* Link the node. */
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 67b08745daf9..677d65253e4c 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -669,7 +669,7 @@ static inline int rt_fast_clean(struct rtable *rth)
 static inline int rt_valuable(struct rtable *rth)
 {
         return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
-                (rt_has_peer(rth) && rt_peer_ptr(rth)->pmtu_expires);
+                rth->dst.expires;
 }
 
 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
@@ -1242,13 +1242,6 @@ skip_hashing:
         return rt;
 }
 
-static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
-
-static u32 rt_peer_genid(void)
-{
-        return atomic_read(&__rt_peer_genid);
-}
-
 void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
 {
         struct inet_peer_base *base;
@@ -1262,8 +1255,6 @@ void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
         if (peer) {
                 if (!rt_set_peer(rt, peer))
                         inet_putpeer(peer);
-                else
-                        rt->rt_peer_genid = rt_peer_genid();
         }
 }
 
@@ -1323,30 +1314,6 @@ static void rt_del(unsigned int hash, struct rtable *rt)
         spin_unlock_bh(rt_hash_lock_addr(hash));
 }
 
-static void check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
-{
-        struct rtable *rt = (struct rtable *) dst;
-        __be32 orig_gw = rt->rt_gateway;
-        struct neighbour *n;
-
-        dst_confirm(&rt->dst);
-
-        rt->rt_gateway = peer->redirect_learned.a4;
-
-        n = ipv4_neigh_lookup(&rt->dst, NULL, &rt->rt_gateway);
-        if (!n) {
-                rt->rt_gateway = orig_gw;
-                return;
-        }
-        if (!(n->nud_state & NUD_VALID)) {
-                neigh_event_send(n, NULL);
-        } else {
-                rt->rt_flags |= RTCF_REDIRECTED;
-                call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
-        }
-        neigh_release(n);
-}
-
 /* called in rcu_read_lock() section */
 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
                     __be32 saddr, struct net_device *dev)
@@ -1355,7 +1322,6 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
         struct in_device *in_dev = __in_dev_get_rcu(dev);
         __be32 skeys[2] = { saddr, 0 };
         int    ikeys[2] = { dev->ifindex, 0 };
-        struct inet_peer *peer;
         struct net *net;
 
         if (!in_dev)
@@ -1388,6 +1354,8 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
                         rthp = &rt_hash_table[hash].chain;
 
                         while ((rt = rcu_dereference(*rthp)) != NULL) {
+                                struct neighbour *n;
+
                                 rthp = &rt->dst.rt_next;
 
                                 if (rt->rt_key_dst != daddr ||
@@ -1401,13 +1369,16 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
                                     rt->rt_gateway != old_gw)
                                         continue;
 
-                                peer = rt_get_peer_create(rt, rt->rt_dst);
-                                if (peer) {
-                                        if (peer->redirect_learned.a4 != new_gw) {
-                                                peer->redirect_learned.a4 = new_gw;
-                                                atomic_inc(&__rt_peer_genid);
+                                n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
+                                if (n) {
+                                        if (!(n->nud_state & NUD_VALID)) {
+                                                neigh_event_send(n, NULL);
+                                        } else {
+                                                rt->rt_gateway = new_gw;
+                                                rt->rt_flags |= RTCF_REDIRECTED;
+                                                call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
                                         }
-                                        check_peer_redir(&rt->dst, peer);
+                                        neigh_release(n);
                                 }
                         }
                 }
@@ -1425,23 +1396,6 @@ reject_redirect:
         ;
 }
 
-static bool peer_pmtu_expired(struct inet_peer *peer)
-{
-        unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
-
-        return orig &&
-               time_after_eq(jiffies, orig) &&
-               cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
-}
-
-static bool peer_pmtu_cleaned(struct inet_peer *peer)
-{
-        unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
-
-        return orig &&
-               cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
-}
-
 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
 {
         struct rtable *rt = (struct rtable *)dst;
@@ -1451,16 +1405,13 @@ static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
                 if (dst->obsolete > 0) {
                         ip_rt_put(rt);
                         ret = NULL;
-                } else if (rt->rt_flags & RTCF_REDIRECTED) {
+                } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
+                           rt->dst.expires) {
                         unsigned int hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
                                                 rt->rt_oif,
                                                 rt_genid(dev_net(dst->dev)));
                         rt_del(hash, rt);
                         ret = NULL;
-                } else if (rt_has_peer(rt)) {
-                        struct inet_peer *peer = rt_peer_ptr(rt);
-                        if (peer_pmtu_expired(peer))
-                                dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
                 }
         }
         return ret;
@@ -1604,50 +1555,17 @@ out:	kfree_skb(skb);
         return 0;
 }
 
-static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
-{
-        unsigned long expires = ACCESS_ONCE(peer->pmtu_expires);
-
-        if (!expires)
-                return;
-        if (time_before(jiffies, expires)) {
-                u32 orig_dst_mtu = dst_mtu(dst);
-                if (peer->pmtu_learned < orig_dst_mtu) {
-                        if (!peer->pmtu_orig)
-                                peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
-                        dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
-                }
-        } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
-                dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
-}
-
 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
 {
         struct rtable *rt = (struct rtable *) dst;
-        struct inet_peer *peer;
 
         dst_confirm(dst);
 
-        peer = rt_get_peer_create(rt, rt->rt_dst);
-        if (peer) {
-                unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires);
-
-                if (mtu < ip_rt_min_pmtu)
-                        mtu = ip_rt_min_pmtu;
-                if (!pmtu_expires || mtu < peer->pmtu_learned) {
-
-                        pmtu_expires = jiffies + ip_rt_mtu_expires;
-                        if (!pmtu_expires)
-                                pmtu_expires = 1UL;
-
-                        peer->pmtu_learned = mtu;
-                        peer->pmtu_expires = pmtu_expires;
+        if (mtu < ip_rt_min_pmtu)
+                mtu = ip_rt_min_pmtu;
 
-                        atomic_inc(&__rt_peer_genid);
-                        rt->rt_peer_genid = rt_peer_genid();
-                }
-                check_peer_pmtu(dst, peer);
-        }
+        rt->rt_pmtu = mtu;
+        dst_set_expires(&rt->dst, ip_rt_mtu_expires);
 }
 
 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
@@ -1679,30 +1597,12 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
 }
 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
 
-static void ipv4_validate_peer(struct rtable *rt)
-{
-        if (rt->rt_peer_genid != rt_peer_genid()) {
-                struct inet_peer *peer = rt_get_peer(rt, rt->rt_dst);
-
-                if (peer) {
-                        check_peer_pmtu(&rt->dst, peer);
-
-                        if (peer->redirect_learned.a4 &&
-                            peer->redirect_learned.a4 != rt->rt_gateway)
-                                check_peer_redir(&rt->dst, peer);
-                }
-
-                rt->rt_peer_genid = rt_peer_genid();
-        }
-}
-
 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
 {
         struct rtable *rt = (struct rtable *) dst;
 
         if (rt_is_expired(rt))
                 return NULL;
-        ipv4_validate_peer(rt);
         return dst;
 }
 
@@ -1728,11 +1628,8 @@ static void ipv4_link_failure(struct sk_buff *skb)
         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
 
         rt = skb_rtable(skb);
-        if (rt && rt_has_peer(rt)) {
-                struct inet_peer *peer = rt_peer_ptr(rt);
-                if (peer_pmtu_cleaned(peer))
-                        dst_metric_set(&rt->dst, RTAX_MTU, peer->pmtu_orig);
-        }
+        if (rt)
+                dst_set_expires(&rt->dst, 0);
 }
 
 static int ip_rt_bug(struct sk_buff *skb)
@@ -1812,7 +1709,13 @@ static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
 static unsigned int ipv4_mtu(const struct dst_entry *dst)
 {
         const struct rtable *rt = (const struct rtable *) dst;
-        unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
+        unsigned int mtu = rt->rt_pmtu;
+
+        if (mtu && time_after_eq(jiffies, rt->dst.expires))
+                mtu = 0;
+
+        if (!mtu)
+                mtu = dst_metric_raw(dst, RTAX_MTU);
 
         if (mtu && rt_is_output_route(rt))
                 return mtu;
@@ -1843,19 +1746,10 @@ static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
         peer = inet_getpeer_v4(base, rt->rt_dst, 0);
         if (peer) {
                 __rt_set_peer(rt, peer);
-                rt->rt_peer_genid = rt_peer_genid();
                 if (inet_metrics_new(peer))
                         memcpy(peer->metrics, fi->fib_metrics,
                                sizeof(u32) * RTAX_MAX);
                 dst_init_metrics(&rt->dst, peer->metrics, false);
-
-                check_peer_pmtu(&rt->dst, peer);
-
-                if (peer->redirect_learned.a4 &&
-                    peer->redirect_learned.a4 != rt->rt_gateway) {
-                        rt->rt_gateway = peer->redirect_learned.a4;
-                        rt->rt_flags |= RTCF_REDIRECTED;
-                }
         } else {
                 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
                         rt->fi = fi;
@@ -1955,8 +1849,8 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
         rth->rt_iif     = dev->ifindex;
         rth->rt_oif     = 0;
         rth->rt_mark    = skb->mark;
+        rth->rt_pmtu    = 0;
         rth->rt_gateway = daddr;
-        rth->rt_peer_genid = 0;
         rt_init_peer(rth, dev_net(dev)->ipv4.peers);
         rth->fi = NULL;
         if (our) {
@@ -2081,8 +1975,8 @@ static int __mkroute_input(struct sk_buff *skb,
         rth->rt_iif     = in_dev->dev->ifindex;
         rth->rt_oif     = 0;
         rth->rt_mark    = skb->mark;
+        rth->rt_pmtu    = 0;
         rth->rt_gateway = daddr;
-        rth->rt_peer_genid = 0;
         rt_init_peer(rth, &res->table->tb_peers);
         rth->fi = NULL;
 
@@ -2260,8 +2154,8 @@ local_input:
         rth->rt_iif     = dev->ifindex;
         rth->rt_oif     = 0;
         rth->rt_mark    = skb->mark;
+        rth->rt_pmtu    = 0;
         rth->rt_gateway = daddr;
-        rth->rt_peer_genid = 0;
         rt_init_peer(rth, net->ipv4.peers);
         rth->fi = NULL;
         if (res.type == RTN_UNREACHABLE) {
@@ -2337,7 +2231,6 @@ int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
                     rth->rt_mark == skb->mark &&
                     net_eq(dev_net(rth->dst.dev), net) &&
                     !rt_is_expired(rth)) {
-                        ipv4_validate_peer(rth);
                         if (noref) {
                                 dst_use_noref(&rth->dst, jiffies);
                                 skb_dst_set_noref(skb, &rth->dst);
@@ -2459,8 +2352,8 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
         rth->rt_iif     = orig_oif ? : dev_out->ifindex;
         rth->rt_oif     = orig_oif;
         rth->rt_mark    = fl4->flowi4_mark;
+        rth->rt_pmtu    = 0;
         rth->rt_gateway = fl4->daddr;
-        rth->rt_peer_genid = 0;
         rt_init_peer(rth, (res->table ?
                            &res->table->tb_peers :
                            dev_net(dev_out)->ipv4.peers));
@@ -2717,7 +2610,6 @@ struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
                             (IPTOS_RT_MASK | RTO_ONLINK)) &&
                     net_eq(dev_net(rth->dst.dev), net) &&
                     !rt_is_expired(rth)) {
-                        ipv4_validate_peer(rth);
                         dst_use(&rth->dst, jiffies);
                         RT_CACHE_STAT_INC(out_hit);
                         rcu_read_unlock_bh();
@@ -2794,6 +2686,7 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or
                 rt->rt_iif = ort->rt_iif;
                 rt->rt_oif = ort->rt_oif;
                 rt->rt_mark = ort->rt_mark;
+                rt->rt_pmtu = ort->rt_pmtu;
 
                 rt->rt_genid = rt_genid(net);
                 rt->rt_flags = ort->rt_flags;
@@ -2896,13 +2789,13 @@ static int rt_fill_info(struct net *net,
                 const struct inet_peer *peer = rt_peer_ptr(rt);
                 inet_peer_refcheck(peer);
                 id = atomic_read(&peer->ip_id_count) & 0xffff;
-                expires = ACCESS_ONCE(peer->pmtu_expires);
-                if (expires) {
-                        if (time_before(jiffies, expires))
-                                expires -= jiffies;
-                        else
-                                expires = 0;
-                }
+        }
+        expires = rt->dst.expires;
+        if (expires) {
+                if (time_before(jiffies, expires))
+                        expires -= jiffies;
+                else
+                        expires = 0;
         }
 
         if (rt_is_input_route(rt)) {
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 9815ea0bca7f..951bcf35b21c 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -100,6 +100,7 @@ static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
         xdst->u.rt.rt_src = rt->rt_src;
         xdst->u.rt.rt_dst = rt->rt_dst;
         xdst->u.rt.rt_gateway = rt->rt_gateway;
+        xdst->u.rt.rt_pmtu = rt->rt_pmtu;
 
         return 0;
 }