From 9fdec5ec64644ce4f4081e045dfbcd7518276edb Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 1 Dec 2011 13:38:59 -0500 Subject: ipv4: Perform peer validation on cached route lookup. [ Upstream commit efbc368dcc6426d5430b9b8eeda944cf2cb74b8c, incorporating a follow-on change to prevent an OOPS ] Otherwise we won't notice the peer GENID change. Reported-by: Steffen Klassert Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/route.c | 41 ++++++++++++++++++++++------------------- 1 file changed, 22 insertions(+), 19 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 65d25725448..5c9b20ff748 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1311,7 +1311,7 @@ static void rt_del(unsigned hash, struct rtable *rt) spin_unlock_bh(rt_hash_lock_addr(hash)); } -static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer) +static void check_peer_redir(struct dst_entry *dst, struct inet_peer *peer) { struct rtable *rt = (struct rtable *) dst; __be32 orig_gw = rt->rt_gateway; @@ -1322,21 +1322,19 @@ static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer) rt->rt_gateway = peer->redirect_learned.a4; n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway); - if (IS_ERR(n)) - return PTR_ERR(n); + if (IS_ERR(n)) { + rt->rt_gateway = orig_gw; + return; + } old_n = xchg(&rt->dst._neighbour, n); if (old_n) neigh_release(old_n); - if (!n || !(n->nud_state & NUD_VALID)) { - if (n) - neigh_event_send(n, NULL); - rt->rt_gateway = orig_gw; - return -EAGAIN; + if (!(n->nud_state & NUD_VALID)) { + neigh_event_send(n, NULL); } else { rt->rt_flags |= RTCF_REDIRECTED; call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); } - return 0; } /* called in rcu_read_lock() section */ @@ -1694,12 +1692,8 @@ static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu) } -static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) +static void ipv4_validate_peer(struct rtable *rt) { - struct rtable *rt = (struct rtable *) dst; - - if (rt_is_expired(rt)) - return NULL; if (rt->rt_peer_genid != rt_peer_genid()) { struct inet_peer *peer; @@ -1708,19 +1702,26 @@ static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) peer = rt->peer; if (peer) { - check_peer_pmtu(dst, peer); + check_peer_pmtu(&rt->dst, peer); if (peer->redirect_genid != redirect_genid) peer->redirect_learned.a4 = 0; if (peer->redirect_learned.a4 && - peer->redirect_learned.a4 != rt->rt_gateway) { - if (check_peer_redir(dst, peer)) - return NULL; - } + peer->redirect_learned.a4 != rt->rt_gateway) + check_peer_redir(&rt->dst, peer); } rt->rt_peer_genid = rt_peer_genid(); } +} + +static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) +{ + struct rtable *rt = (struct rtable *) dst; + + if (rt_is_expired(rt)) + return NULL; + ipv4_validate_peer(rt); return dst; } @@ -2370,6 +2371,7 @@ int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr, rth->rt_mark == skb->mark && net_eq(dev_net(rth->dst.dev), net) && !rt_is_expired(rth)) { + ipv4_validate_peer(rth); if (noref) { dst_use_noref(&rth->dst, jiffies); skb_dst_set_noref(skb, &rth->dst); @@ -2745,6 +2747,7 @@ struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4) (IPTOS_RT_MASK | RTO_ONLINK)) && net_eq(dev_net(rth->dst.dev), net) && !rt_is_expired(rth)) { + ipv4_validate_peer(rth); dst_use(&rth->dst, jiffies); RT_CACHE_STAT_INC(out_hit); rcu_read_unlock_bh(); -- cgit v1.2.3