{
struct rt6_info *rt6 = (struct rt6_info*)dst;
+ dst_confirm(dst);
if (mtu < dst_mtu(dst) && rt6->rt6i_dst.plen == 128) {
+ struct net *net = dev_net(dst->dev);
+
rt6->rt6i_flags |= RTF_MODIFIED;
if (mtu < IPV6_MIN_MTU) {
u32 features = dst_metric(dst, RTAX_FEATURES);
dst_metric_set(dst, RTAX_FEATURES, features);
}
dst_metric_set(dst, RTAX_MTU, mtu);
+ rt6_update_expires(rt6, net->ipv6.sysctl.ip6_rt_mtu_expires);
}
}
+void ip6_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
+ int oif, __be32 mark)
+{
+ const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
+ struct dst_entry *dst;
+ struct flowi6 fl6;
+
+ memset(&fl6, 0, sizeof(fl6));
+ fl6.flowi6_oif = oif;
+ fl6.flowi6_mark = mark;
+ fl6.flowi6_flags = FLOWI_FLAG_PRECOW_METRICS;
+ fl6.daddr = iph->daddr;
+ fl6.saddr = iph->saddr;
+ fl6.flowlabel = (*(__be32 *) iph) & IPV6_FLOWINFO_MASK;
+
+ dst = ip6_route_output(net, NULL, &fl6);
+ if (!dst->error)
+ ip6_rt_update_pmtu(dst, ntohl(mtu));
+ dst_release(dst);
+}
+EXPORT_SYMBOL_GPL(ip6_update_pmtu);
+
+void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
+{
+ ip6_update_pmtu(skb, sock_net(sk), mtu,
+ sk->sk_bound_dev_if, sk->sk_mark);
+}
+EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
+
static unsigned int ip6_default_advmss(const struct dst_entry *dst)
{
struct net_device *dev = dst->dev;
dst_release(&rt->dst);
}
-/*
- * Handle ICMP "packet too big" messages
- * i.e. Path MTU discovery
- */
-
-static void rt6_do_pmtu_disc(const struct in6_addr *daddr, const struct in6_addr *saddr,
- struct net *net, u32 pmtu, int ifindex)
-{
- struct rt6_info *rt, *nrt;
- int allfrag = 0;
-again:
- rt = rt6_lookup(net, daddr, saddr, ifindex, 0);
- if (!rt)
- return;
-
- if (rt6_check_expired(rt)) {
- ip6_del_rt(rt);
- goto again;
- }
-
- if (pmtu >= dst_mtu(&rt->dst))
- goto out;
-
- if (pmtu < IPV6_MIN_MTU) {
- /*
- * According to RFC2460, PMTU is set to the IPv6 Minimum Link
- * MTU (1280) and a fragment header should always be included
- * after a node receiving Too Big message reporting PMTU is
- * less than the IPv6 Minimum Link MTU.
- */
- pmtu = IPV6_MIN_MTU;
- allfrag = 1;
- }
-
- /* New mtu received -> path was valid.
- They are sent only in response to data packets,
- so that this nexthop apparently is reachable. --ANK
- */
- dst_confirm(&rt->dst);
-
- /* Host route. If it is static, it would be better
- not to override it, but add new one, so that
- when cache entry will expire old pmtu
- would return automatically.
- */
- if (rt->rt6i_flags & RTF_CACHE) {
- dst_metric_set(&rt->dst, RTAX_MTU, pmtu);
- if (allfrag) {
- u32 features = dst_metric(&rt->dst, RTAX_FEATURES);
- features |= RTAX_FEATURE_ALLFRAG;
- dst_metric_set(&rt->dst, RTAX_FEATURES, features);
- }
- rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
- rt->rt6i_flags |= RTF_MODIFIED;
- goto out;
- }
-
- /* Network route.
- Two cases are possible:
- 1. It is connected route. Action: COW
- 2. It is gatewayed route or NONEXTHOP route. Action: clone it.
- */
- if (!dst_get_neighbour_noref_raw(&rt->dst) && !(rt->rt6i_flags & RTF_NONEXTHOP))
- nrt = rt6_alloc_cow(rt, daddr, saddr);
- else
- nrt = rt6_alloc_clone(rt, daddr);
-
- if (nrt) {
- dst_metric_set(&nrt->dst, RTAX_MTU, pmtu);
- if (allfrag) {
- u32 features = dst_metric(&nrt->dst, RTAX_FEATURES);
- features |= RTAX_FEATURE_ALLFRAG;
- dst_metric_set(&nrt->dst, RTAX_FEATURES, features);
- }
-
- /* According to RFC 1981, detecting PMTU increase shouldn't be
- * happened within 5 mins, the recommended timer is 10 mins.
- * Here this route expiration time is set to ip6_rt_mtu_expires
- * which is 10 mins. After 10 mins the decreased pmtu is expired
- * and detecting PMTU increase will be automatically happened.
- */
- rt6_update_expires(nrt, net->ipv6.sysctl.ip6_rt_mtu_expires);
- nrt->rt6i_flags |= RTF_DYNAMIC;
- ip6_ins_rt(nrt);
- }
-out:
- dst_release(&rt->dst);
-}
-
-void rt6_pmtu_discovery(const struct in6_addr *daddr, const struct in6_addr *saddr,
- struct net_device *dev, u32 pmtu)
-{
- struct net *net = dev_net(dev);
-
- /*
- * RFC 1981 states that a node "MUST reduce the size of the packets it
- * is sending along the path" that caused the Packet Too Big message.
- * Since it's not possible in the general case to determine which
- * interface was used to send the original packet, we update the MTU
- * on the interface that will be used to send future packets. We also
- * update the MTU on the interface that received the Packet Too Big in
- * case the original packet was forced out that interface with
- * SO_BINDTODEVICE or similar. This is the next best thing to the
- * correct behaviour, which would be to update the MTU on all
- * interfaces.
- */
- rt6_do_pmtu_disc(daddr, saddr, net, pmtu, 0);
- rt6_do_pmtu_disc(daddr, saddr, net, pmtu, dev->ifindex);
-}
-
/*
* Misc support functions
*/
projects / karo-tx-linux.git / commitdiff