From e47a185b31dd2acd424fac7dc0efb96fc5b31a33 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 11 Jul 2012 20:55:47 -0700 Subject: ipv4: Generalize ip_do_redirect() and hook into new dst_ops->redirect. All of the redirect acceptance policy is now contained within. Signed-off-by: David S. Miller --- include/net/dst_ops.h | 1 + net/ipv4/route.c | 94 +++++++++++++++++++++++++++++---------------------- 2 files changed, 55 insertions(+), 40 deletions(-) diff --git a/include/net/dst_ops.h b/include/net/dst_ops.h index 4badc86e45d1..085931fa7ce0 100644 --- a/include/net/dst_ops.h +++ b/include/net/dst_ops.h @@ -25,6 +25,7 @@ struct dst_ops { struct dst_entry * (*negative_advice)(struct dst_entry *); void (*link_failure)(struct sk_buff *); void (*update_pmtu)(struct dst_entry *dst, u32 mtu); + void (*redirect)(struct dst_entry *dst, struct sk_buff *skb); int (*local_out)(struct sk_buff *skb); struct neighbour * (*neigh_lookup)(const struct dst_entry *dst, struct sk_buff *skb, diff --git a/net/ipv4/route.c b/net/ipv4/route.c index f8921b448c39..f3d25656ddb0 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -149,6 +149,7 @@ static void ipv4_dst_destroy(struct dst_entry *dst); 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 void ip_do_redirect(struct dst_entry *dst, struct sk_buff *skb); static int rt_garbage_collect(struct dst_ops *ops); static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, @@ -179,6 +180,7 @@ static struct dst_ops ipv4_dst_ops = { .negative_advice = ipv4_negative_advice, .link_failure = ipv4_link_failure, .update_pmtu = ip_rt_update_pmtu, + .redirect = ip_do_redirect, .local_out = __ip_local_out, .neigh_lookup = ipv4_neigh_lookup, }; @@ -1271,42 +1273,18 @@ static void rt_del(unsigned int hash, struct rtable *rt) spin_unlock_bh(rt_hash_lock_addr(hash)); } -static void ip_do_redirect(struct rtable *rt, __be32 old_gw, __be32 new_gw) -{ - struct neighbour *n; - - if (rt->rt_gateway != old_gw) - return; - - n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw); - if (n) { - if (!(n->nud_state & NUD_VALID)) { - neigh_event_send(n, NULL); - } else { - rt->rt_gateway = new_gw; - rt->rt_flags |= RTCF_REDIRECTED; - call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); - } - neigh_release(n); - } -} - -/* called in rcu_read_lock() section */ -void ip_rt_redirect(struct sk_buff *skb, __be32 new_gw) +static void ip_do_redirect(struct dst_entry *dst, struct sk_buff *skb) { const struct iphdr *iph = (const struct iphdr *) skb->data; + __be32 new_gw = icmp_hdr(skb)->un.gateway; __be32 old_gw = ip_hdr(skb)->saddr; + struct net_device *dev = skb->dev; __be32 daddr = iph->daddr; __be32 saddr = iph->saddr; - struct net_device *dev = skb->dev; - struct in_device *in_dev = __in_dev_get_rcu(dev); - int ikeys[2] = { dev->ifindex, 0 }; - __be32 skeys[2] = { saddr, 0 }; + struct in_device *in_dev; + struct neighbour *n; + struct rtable *rt; struct net *net; - int s, i; - - if (!in_dev) - return; switch (icmp_hdr(skb)->code & 7) { case ICMP_REDIR_NET: @@ -1319,6 +1297,14 @@ void ip_rt_redirect(struct sk_buff *skb, __be32 new_gw) return; } + rt = (struct rtable *) dst; + if (rt->rt_gateway != old_gw) + return; + + in_dev = __in_dev_get_rcu(dev); + if (!in_dev) + return; + net = dev_net(dev); if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || @@ -1335,6 +1321,43 @@ void ip_rt_redirect(struct sk_buff *skb, __be32 new_gw) goto reject_redirect; } + n = ipv4_neigh_lookup(dst, NULL, &new_gw); + if (n) { + if (!(n->nud_state & NUD_VALID)) { + neigh_event_send(n, NULL); + } else { + rt->rt_gateway = new_gw; + rt->rt_flags |= RTCF_REDIRECTED; + call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); + } + neigh_release(n); + } + return; + +reject_redirect: +#ifdef CONFIG_IP_ROUTE_VERBOSE + if (IN_DEV_LOG_MARTIANS(in_dev)) + net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" + " Advised path = %pI4 -> %pI4\n", + &old_gw, dev->name, &new_gw, + &saddr, &daddr); +#endif + ; +} + +/* called in rcu_read_lock() section */ +void ip_rt_redirect(struct sk_buff *skb, __be32 new_gw) +{ + const struct iphdr *iph = (const struct iphdr *) skb->data; + __be32 daddr = iph->daddr; + __be32 saddr = iph->saddr; + struct net_device *dev = skb->dev; + int ikeys[2] = { dev->ifindex, 0 }; + __be32 skeys[2] = { saddr, 0 }; + struct net *net; + int s, i; + + net = dev_net(dev); for (s = 0; s < 2; s++) { for (i = 0; i < 2; i++) { unsigned int hash; @@ -1358,21 +1381,12 @@ void ip_rt_redirect(struct sk_buff *skb, __be32 new_gw) rt->dst.dev != dev) continue; - ip_do_redirect(rt, old_gw, new_gw); + ip_do_redirect(&rt->dst, skb); } } } return; -reject_redirect: -#ifdef CONFIG_IP_ROUTE_VERBOSE - if (IN_DEV_LOG_MARTIANS(in_dev)) - net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" - " Advised path = %pI4 -> %pI4\n", - &old_gw, dev->name, &new_gw, - &saddr, &daddr); -#endif - ; } static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) -- cgit v1.2.3-59-g8ed1b