1 files changed, 70 insertions, 35 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index b2ba5581d2ae..cb562fdd9b9a 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -90,6 +90,7 @@
 #include <linux/jhash.h>
 #include <linux/rcupdate.h>
 #include <linux/times.h>
+#include <linux/slab.h>
 #include <net/dst.h>
 #include <net/net_namespace.h>
 #include <net/protocol.h>
@@ -146,7 +147,6 @@ static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
 static void              ipv4_link_failure(struct sk_buff *skb);
 static void              ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
 static int rt_garbage_collect(struct dst_ops *ops);
-static void rt_emergency_hash_rebuild(struct net *net);
 
 
 static struct dst_ops ipv4_dst_ops = {
@@ -780,11 +780,30 @@ static void rt_do_flush(int process_context)
 #define FRACT_BITS 3
 #define ONE (1UL << FRACT_BITS)
 
+/*
+ * Given a hash chain and an item in this hash chain,
+ * find if a previous entry has the same hash_inputs
+ * (but differs on tos, mark or oif)
+ * Returns 0 if an alias is found.
+ * Returns ONE if rth has no alias before itself.
+ */
+static int has_noalias(const struct rtable *head, const struct rtable *rth)
+{
+        const struct rtable *aux = head;
+
+        while (aux != rth) {
+                if (compare_hash_inputs(&aux->fl, &rth->fl))
+                        return 0;
+                aux = aux->u.dst.rt_next;
+        }
+        return ONE;
+}
+
 static void rt_check_expire(void)
 {
         static unsigned int rover;
         unsigned int i = rover, goal;
-        struct rtable *rth, *aux, **rthp;
+        struct rtable *rth, **rthp;
         unsigned long samples = 0;
         unsigned long sum = 0, sum2 = 0;
         unsigned long delta;
@@ -835,15 +854,7 @@ nofree:
                                          * attributes don't unfairly skew
                                          * the length computation
                                          */
-                                        for (aux = rt_hash_table[i].chain;;) {
-                                                if (aux == rth) {
-                                                        length += ONE;
-                                                        break;
-                                                }
-                                                if (compare_hash_inputs(&aux->fl, &rth->fl))
-                                                        break;
-                                                aux = aux->u.dst.rt_next;
-                                        }
+                                        length += has_noalias(rt_hash_table[i].chain, rth);
                                         continue;
                                 }
                         } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout))
@@ -922,10 +933,8 @@ static void rt_secret_rebuild_oneshot(struct net *net)
 {
         del_timer_sync(&net->ipv4.rt_secret_timer);
         rt_cache_invalidate(net);
-        if (ip_rt_secret_interval) {
-                net->ipv4.rt_secret_timer.expires += ip_rt_secret_interval;
-                add_timer(&net->ipv4.rt_secret_timer);
-        }
+        if (ip_rt_secret_interval)
+                mod_timer(&net->ipv4.rt_secret_timer, jiffies + ip_rt_secret_interval);
 }
 
 static void rt_emergency_hash_rebuild(struct net *net)
@@ -1073,8 +1082,23 @@ work_done:
 out:    return 0;
 }
 
+/*
+ * Returns number of entries in a hash chain that have different hash_inputs
+ */
+static int slow_chain_length(const struct rtable *head)
+{
+        int length = 0;
+        const struct rtable *rth = head;
+
+        while (rth) {
+                length += has_noalias(head, rth);
+                rth = rth->u.dst.rt_next;
+        }
+        return length >> FRACT_BITS;
+}
+
 static int rt_intern_hash(unsigned hash, struct rtable *rt,
-                          struct rtable **rp, struct sk_buff *skb)
+                          struct rtable **rp, struct sk_buff *skb, int ifindex)
 {
         struct rtable   *rth, **rthp;
         unsigned long   now;
@@ -1185,14 +1209,20 @@ restart:
                         rt_free(cand);
                 }
         } else {
-                if (chain_length > rt_chain_length_max) {
+                if (chain_length > rt_chain_length_max &&
+                    slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
                         struct net *net = dev_net(rt->u.dst.dev);
                         int num = ++net->ipv4.current_rt_cache_rebuild_count;
-                        if (!rt_caching(dev_net(rt->u.dst.dev))) {
+                        if (!rt_caching(net)) {
                                 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
                                         rt->u.dst.dev->name, num);
                         }
-                        rt_emergency_hash_rebuild(dev_net(rt->u.dst.dev));
+                        rt_emergency_hash_rebuild(net);
+                        spin_unlock_bh(rt_hash_lock_addr(hash));
+
+                        hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
+                                        ifindex, rt_genid(net));
+                        goto restart;
                 }
         }
 
@@ -1417,7 +1447,7 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
                                         dev_hold(rt->u.dst.dev);
                                 if (rt->idev)
                                         in_dev_hold(rt->idev);
-                                rt->u.dst.obsolete      = 0;
+                                rt->u.dst.obsolete      = -1;
                                 rt->u.dst.lastuse       = jiffies;
                                 rt->u.dst.path          = &rt->u.dst;
                                 rt->u.dst.neighbour     = NULL;
@@ -1453,7 +1483,7 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
                                                         &netevent);
 
                                 rt_del(hash, rth);
-                                if (!rt_intern_hash(hash, rt, &rt, NULL))
+                                if (!rt_intern_hash(hash, rt, &rt, NULL, rt->fl.oif))
                                         ip_rt_put(rt);
                                 goto do_next;
                         }
@@ -1482,11 +1512,12 @@ static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
         struct dst_entry *ret = dst;
 
         if (rt) {
-                if (dst->obsolete) {
+                if (dst->obsolete > 0) {
                         ip_rt_put(rt);
                         ret = NULL;
                 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
-                           rt->u.dst.expires) {
+                           (rt->u.dst.expires &&
+                            time_after_eq(jiffies, rt->u.dst.expires))) {
                         unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
                                                 rt->fl.oif,
                                                 rt_genid(dev_net(dst->dev)));
@@ -1702,7 +1733,9 @@ static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
 
 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
 {
-        return NULL;
+        if (rt_is_expired((struct rtable *)dst))
+                return NULL;
+        return dst;
 }
 
 static void ipv4_dst_destroy(struct dst_entry *dst)
@@ -1864,7 +1897,8 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
         if (!rth)
                 goto e_nobufs;
 
-        rth->u.dst.output= ip_rt_bug;
+        rth->u.dst.output = ip_rt_bug;
+        rth->u.dst.obsolete = -1;
 
         atomic_set(&rth->u.dst.__refcnt, 1);
         rth->u.dst.flags= DST_HOST;
@@ -1903,7 +1937,7 @@ 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, NULL, skb);
+        return rt_intern_hash(hash, rth, NULL, skb, dev->ifindex);
 
 e_nobufs:
         in_dev_put(in_dev);
@@ -2030,6 +2064,7 @@ static int __mkroute_input(struct sk_buff *skb,
         rth->fl.oif     = 0;
         rth->rt_spec_dst= spec_dst;
 
+        rth->u.dst.obsolete = -1;
         rth->u.dst.input = ip_forward;
         rth->u.dst.output = ip_output;
         rth->rt_genid = rt_genid(dev_net(rth->u.dst.dev));
@@ -2069,7 +2104,7 @@ 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, NULL, skb);
+        return rt_intern_hash(hash, rth, NULL, skb, fl->iif);
 }
 
 /*
@@ -2194,6 +2229,7 @@ local_input:
                 goto e_nobufs;
 
         rth->u.dst.output= ip_rt_bug;
+        rth->u.dst.obsolete = -1;
         rth->rt_genid = rt_genid(net);
 
         atomic_set(&rth->u.dst.__refcnt, 1);
@@ -2225,7 +2261,7 @@ local_input:
         }
         rth->rt_type    = res.type;
         hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net));
-        err = rt_intern_hash(hash, rth, NULL, skb);
+        err = rt_intern_hash(hash, rth, NULL, skb, fl.iif);
         goto done;
 
 no_route:
@@ -2420,6 +2456,7 @@ static int __mkroute_output(struct rtable **result,
         rth->rt_spec_dst= fl->fl4_src;
 
         rth->u.dst.output=ip_output;
+        rth->u.dst.obsolete = -1;
         rth->rt_genid = rt_genid(dev_net(dev_out));
 
         RT_CACHE_STAT_INC(out_slow_tot);
@@ -2471,7 +2508,7 @@ 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, NULL);
+                err = rt_intern_hash(hash, rth, rp, NULL, oldflp->oif);
         }
 
         return err;
@@ -3077,22 +3114,20 @@ static void rt_secret_reschedule(int old)
         rtnl_lock();
         for_each_net(net) {
                 int deleted = del_timer_sync(&net->ipv4.rt_secret_timer);
+                long time;
 
                 if (!new)
                         continue;
 
                 if (deleted) {
-                        long time = net->ipv4.rt_secret_timer.expires - jiffies;
+                        time = net->ipv4.rt_secret_timer.expires - jiffies;
 
                         if (time <= 0 || (time += diff) <= 0)
                                 time = 0;
-
-                        net->ipv4.rt_secret_timer.expires = time;
                 } else
-                        net->ipv4.rt_secret_timer.expires = new;
+                        time = new;
 
-                net->ipv4.rt_secret_timer.expires += jiffies;
-                add_timer(&net->ipv4.rt_secret_timer);
+                mod_timer(&net->ipv4.rt_secret_timer, jiffies + time);
         }
         rtnl_unlock();
 }