ipv4: Update MTU to all related cache entries in ip_rt_frag_needed()
Add struct net_device parameter to ip_rt_frag_needed() and update MTU to
cache entries where ifindex is specified. This is similar to what is
already done in ip_rt_redirect().
Signed-off-by: Timo Teras <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index ce25a13..5e3685c 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1430,11 +1430,13 @@
}
unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph,
- unsigned short new_mtu)
+ unsigned short new_mtu,
+ struct net_device *dev)
{
- int i;
+ int i, k;
unsigned short old_mtu = ntohs(iph->tot_len);
struct rtable *rth;
+ int ikeys[2] = { dev->ifindex, 0 };
__be32 skeys[2] = { iph->saddr, 0, };
__be32 daddr = iph->daddr;
unsigned short est_mtu = 0;
@@ -1442,22 +1444,26 @@
if (ipv4_config.no_pmtu_disc)
return 0;
- for (i = 0; i < 2; i++) {
- unsigned hash = rt_hash(daddr, skeys[i], 0);
+ for (k = 0; k < 2; k++) {
+ for (i = 0; i < 2; i++) {
+ unsigned hash = rt_hash(daddr, skeys[i], ikeys[k]);
- rcu_read_lock();
- for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
- rth = rcu_dereference(rth->u.dst.rt_next)) {
- if (rth->fl.fl4_dst == daddr &&
- rth->fl.fl4_src == skeys[i] &&
- rth->rt_dst == daddr &&
- rth->rt_src == iph->saddr &&
- rth->fl.iif == 0 &&
- !(dst_metric_locked(&rth->u.dst, RTAX_MTU)) &&
- net_eq(dev_net(rth->u.dst.dev), net) &&
- rth->rt_genid == atomic_read(&rt_genid)) {
+ rcu_read_lock();
+ for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
+ rth = rcu_dereference(rth->u.dst.rt_next)) {
unsigned short mtu = new_mtu;
+ if (rth->fl.fl4_dst != daddr ||
+ rth->fl.fl4_src != skeys[i] ||
+ rth->rt_dst != daddr ||
+ rth->rt_src != iph->saddr ||
+ rth->fl.oif != ikeys[k] ||
+ rth->fl.iif != 0 ||
+ dst_metric_locked(&rth->u.dst, RTAX_MTU) ||
+ !net_eq(dev_net(rth->u.dst.dev), net) ||
+ rth->rt_genid != atomic_read(&rt_genid))
+ continue;
+
if (new_mtu < 68 || new_mtu >= old_mtu) {
/* BSD 4.2 compatibility hack :-( */
@@ -1483,8 +1489,8 @@
est_mtu = mtu;
}
}
+ rcu_read_unlock();
}
- rcu_read_unlock();
}
return est_mtu ? : new_mtu;
}