From f39925dbde7788cfb96419c0f092b086aa325c0f Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 9 Feb 2011 22:00:16 -0800 Subject: [PATCH] ipv4: Cache learned redirect information in inetpeer. Note that we do not generate the redirect netevent any longer, because we don't create a new cached route. Instead, once the new neighbour is bound to the cached route, we emit a neigh update event instead. Signed-off-by: David S. Miller --- net/ipv4/route.c | 136 +++++++++++++++-------------------------------- 1 file changed, 42 insertions(+), 94 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 11faf14c7430..756f5443b5f7 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1294,13 +1294,8 @@ static void rt_del(unsigned hash, struct rtable *rt) void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, __be32 saddr, struct net_device *dev) { - int i, k; struct in_device *in_dev = __in_dev_get_rcu(dev); - struct rtable *rth; - struct rtable __rcu **rthp; - __be32 skeys[2] = { saddr, 0 }; - int ikeys[2] = { dev->ifindex, 0 }; - struct netevent_redirect netevent; + struct inet_peer *peer; struct net *net; if (!in_dev) @@ -1312,9 +1307,6 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, ipv4_is_zeronet(new_gw)) goto reject_redirect; - if (!rt_caching(net)) - goto reject_redirect; - if (!IN_DEV_SHARED_MEDIA(in_dev)) { if (!inet_addr_onlink(in_dev, new_gw, old_gw)) goto reject_redirect; @@ -1325,93 +1317,13 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, goto reject_redirect; } - for (i = 0; i < 2; i++) { - for (k = 0; k < 2; k++) { - unsigned hash = rt_hash(daddr, skeys[i], ikeys[k], - rt_genid(net)); - - rthp = &rt_hash_table[hash].chain; - - while ((rth = rcu_dereference(*rthp)) != NULL) { - struct rtable *rt; - - if (rth->fl.fl4_dst != daddr || - rth->fl.fl4_src != skeys[i] || - rth->fl.oif != ikeys[k] || - rt_is_input_route(rth) || - rt_is_expired(rth) || - !net_eq(dev_net(rth->dst.dev), net)) { - rthp = &rth->dst.rt_next; - continue; - } - - if (rth->rt_dst != daddr || - rth->rt_src != saddr || - rth->dst.error || - rth->rt_gateway != old_gw || - rth->dst.dev != dev) - break; - - dst_hold(&rth->dst); - - rt = dst_alloc(&ipv4_dst_ops); - if (rt == NULL) { - ip_rt_put(rth); - return; - } - - /* Copy all the information. */ - *rt = *rth; - rt->dst.__use = 1; - atomic_set(&rt->dst.__refcnt, 1); - rt->dst.child = NULL; - if (rt->dst.dev) - dev_hold(rt->dst.dev); - rt->dst.obsolete = -1; - rt->dst.lastuse = jiffies; - rt->dst.path = &rt->dst; - rt->dst.neighbour = NULL; - rt->dst.hh = NULL; -#ifdef CONFIG_XFRM - rt->dst.xfrm = NULL; -#endif - rt->rt_genid = rt_genid(net); - rt->rt_flags |= RTCF_REDIRECTED; - - /* Gateway is different ... */ - rt->rt_gateway = new_gw; - - /* Redirect received -> path was valid */ - dst_confirm(&rth->dst); - - if (rt->peer) - atomic_inc(&rt->peer->refcnt); - if (rt->fi) - atomic_inc(&rt->fi->fib_clntref); - - if (arp_bind_neighbour(&rt->dst) || - !(rt->dst.neighbour->nud_state & - NUD_VALID)) { - if (rt->dst.neighbour) - neigh_event_send(rt->dst.neighbour, NULL); - ip_rt_put(rth); - rt_drop(rt); - goto do_next; - } + peer = inet_getpeer_v4(daddr, 1); + if (peer) { + peer->redirect_learned.a4 = new_gw; - netevent.old = &rth->dst; - netevent.new = &rt->dst; - call_netevent_notifiers(NETEVENT_REDIRECT, - &netevent); + inet_putpeer(peer); - rt_del(hash, rth); - if (!rt_intern_hash(hash, rt, &rt, NULL, rt->fl.oif)) - ip_rt_put(rt); - goto do_next; - } - do_next: - ; - } + atomic_inc(&__rt_peer_genid); } return; @@ -1678,6 +1590,31 @@ static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu) } } +static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer) +{ + struct rtable *rt = (struct rtable *) dst; + __be32 orig_gw = rt->rt_gateway; + + dst_confirm(&rt->dst); + + neigh_release(rt->dst.neighbour); + rt->dst.neighbour = NULL; + + rt->rt_gateway = peer->redirect_learned.a4; + if (arp_bind_neighbour(&rt->dst) || + !(rt->dst.neighbour->nud_state & NUD_VALID)) { + if (rt->dst.neighbour) + neigh_event_send(rt->dst.neighbour, NULL); + rt->rt_gateway = orig_gw; + return -EAGAIN; + } else { + rt->rt_flags |= RTCF_REDIRECTED; + call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, + rt->dst.neighbour); + } + return 0; +} + static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) { struct rtable *rt = (struct rtable *) dst; @@ -1694,6 +1631,12 @@ static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) if (peer && peer->pmtu_expires) check_peer_pmtu(dst, peer); + if (peer && peer->redirect_learned.a4 && + peer->redirect_learned.a4 != rt->rt_gateway) { + if (check_peer_redir(dst, peer)) + return NULL; + } + rt->rt_peer_genid = rt_peer_genid(); } return dst; @@ -1830,6 +1773,11 @@ static void rt_init_metrics(struct rtable *rt, struct fib_info *fi) if (peer->pmtu_expires) check_peer_pmtu(&rt->dst, peer); + if (peer->redirect_learned.a4 && + peer->redirect_learned.a4 != rt->rt_gateway) { + rt->rt_gateway = peer->redirect_learned.a4; + rt->rt_flags |= RTCF_REDIRECTED; + } } else { if (fi->fib_metrics != (u32 *) dst_default_metrics) { rt->fi = fi; -- GitLab