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Diffstat (limited to 'net/ipv4/route.c')
-rw-r--r--net/ipv4/route.c94
1 files changed, 61 insertions, 33 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 04762d3bef7..32d396196df 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -146,7 +146,6 @@ 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 = {
@@ -287,12 +286,12 @@ static struct rtable *rt_cache_get_first(struct seq_file *seq)
if (!rt_hash_table[st->bucket].chain)
continue;
rcu_read_lock_bh();
- r = rcu_dereference(rt_hash_table[st->bucket].chain);
+ r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
while (r) {
if (dev_net(r->u.dst.dev) == seq_file_net(seq) &&
r->rt_genid == st->genid)
return r;
- r = rcu_dereference(r->u.dst.rt_next);
+ r = rcu_dereference_bh(r->u.dst.rt_next);
}
rcu_read_unlock_bh();
}
@@ -314,7 +313,7 @@ static struct rtable *__rt_cache_get_next(struct seq_file *seq,
rcu_read_lock_bh();
r = rt_hash_table[st->bucket].chain;
}
- return rcu_dereference(r);
+ return rcu_dereference_bh(r);
}
static struct rtable *rt_cache_get_next(struct seq_file *seq,
@@ -780,11 +779,30 @@ 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 +853,7 @@ 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 +932,8 @@ 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)
@@ -1073,6 +1081,21 @@ 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)
{
@@ -1185,7 +1208,8 @@ 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))) {
@@ -1417,7 +1441,7 @@ 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;
@@ -1482,7 +1506,7 @@ 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) ||
@@ -1702,7 +1726,9 @@ 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 +1890,8 @@ 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;
@@ -2030,6 +2057,7 @@ 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));
@@ -2194,6 +2222,7 @@ 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);
@@ -2420,6 +2449,7 @@ 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);
@@ -2694,8 +2724,8 @@ int __ip_route_output_key(struct net *net, struct rtable **rp,
hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net));
rcu_read_lock_bh();
- for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
- rth = rcu_dereference(rth->u.dst.rt_next)) {
+ for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
+ rth = rcu_dereference_bh(rth->u.dst.rt_next)) {
if (rth->fl.fl4_dst == flp->fl4_dst &&
rth->fl.fl4_src == flp->fl4_src &&
rth->fl.iif == 0 &&
@@ -3013,8 +3043,8 @@ int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
if (!rt_hash_table[h].chain)
continue;
rcu_read_lock_bh();
- for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt;
- rt = rcu_dereference(rt->u.dst.rt_next), idx++) {
+ for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
+ rt = rcu_dereference_bh(rt->u.dst.rt_next), idx++) {
if (!net_eq(dev_net(rt->u.dst.dev), net) || idx < s_idx)
continue;
if (rt_is_expired(rt))
@@ -3077,22 +3107,20 @@ 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();
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-01-31 10:08:59 +0000