diff options
Diffstat (limited to 'net/ipv6/route.c')
| -rw-r--r-- | net/ipv6/route.c | 143 |
1 files changed, 33 insertions, 110 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 58a3ec2..0d41f68 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1049,7 +1049,10 @@ static void ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu) { 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); @@ -1058,9 +1061,39 @@ static void ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu) 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; @@ -1704,116 +1737,6 @@ out: } /* - * 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 */ |
