From de68dca1816660b0d3ac89fa59ffb410007a143f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 26 Nov 2011 12:13:44 +0000 Subject: inet: add a redirect generation id in inetpeer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Now inetpeer is the place where we cache redirect information for ipv4 destinations, we must be able to invalidate informations when a route is added/removed on host. As inetpeer is not yet namespace aware, this patch adds a shared redirect_genid, and a per inetpeer redirect_genid. This might be changed later if inetpeer becomes ns aware. Cache information for one inerpeer is valid as long as its redirect_genid has the same value than global redirect_genid. Reported-by: Arkadiusz Miśkiewicz Tested-by: Arkadiusz Miśkiewicz Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/route.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'net/ipv4/route.c') diff --git a/net/ipv4/route.c b/net/ipv4/route.c index fb47c8f0cd86..5c2847247f51 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -131,6 +131,7 @@ static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; static int ip_rt_min_advmss __read_mostly = 256; static int rt_chain_length_max __read_mostly = 20; +static int redirect_genid; /* * Interface to generic destination cache. @@ -837,6 +838,7 @@ static void rt_cache_invalidate(struct net *net) get_random_bytes(&shuffle, sizeof(shuffle)); atomic_add(shuffle + 1U, &net->ipv4.rt_genid); + redirect_genid++; } /* @@ -1391,8 +1393,10 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, peer = rt->peer; if (peer) { - if (peer->redirect_learned.a4 != new_gw) { + if (peer->redirect_learned.a4 != new_gw || + peer->redirect_genid != redirect_genid) { peer->redirect_learned.a4 = new_gw; + peer->redirect_genid = redirect_genid; atomic_inc(&__rt_peer_genid); } check_peer_redir(&rt->dst, peer); @@ -1701,6 +1705,8 @@ static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) if (peer) { check_peer_pmtu(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)) @@ -1857,6 +1863,8 @@ static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4, dst_init_metrics(&rt->dst, peer->metrics, false); 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) { rt->rt_gateway = peer->redirect_learned.a4; -- cgit v1.2.3 From 218fa90f072e4aeff9003d57e390857f4f35513e Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 29 Nov 2011 20:05:55 +0000 Subject: ipv4: fix lockdep splat in rt_cache_seq_show After commit f2c31e32b378 (fix NULL dereferences in check_peer_redir()), dst_get_neighbour() should be guarded by rcu_read_lock() / rcu_read_unlock() section. Reported-by: Miles Lane Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/route.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/ipv4/route.c') diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 5c2847247f51..57e01bc60947 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -417,9 +417,13 @@ static int rt_cache_seq_show(struct seq_file *seq, void *v) else { struct rtable *r = v; struct neighbour *n; - int len; + int len, HHUptod; + rcu_read_lock(); n = dst_get_neighbour(&r->dst); + HHUptod = (n && (n->nud_state & NUD_CONNECTED)) ? 1 : 0; + rcu_read_unlock(); + seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t" "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n", r->dst.dev ? r->dst.dev->name : "*", @@ -433,7 +437,7 @@ static int rt_cache_seq_show(struct seq_file *seq, void *v) dst_metric(&r->dst, RTAX_RTTVAR)), r->rt_key_tos, -1, - (n && (n->nud_state & NUD_CONNECTED)) ? 1 : 0, + HHUptod, r->rt_spec_dst, &len); seq_printf(seq, "%*s\n", 127 - len, ""); -- cgit v1.2.3 From efbc368dcc6426d5430b9b8eeda944cf2cb74b8c 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. Otherwise we won't notice the peer GENID change. Reported-by: Steffen Klassert Signed-off-by: David S. Miller --- net/ipv4/route.c | 26 +++++++++++++++++++------- 1 file changed, 19 insertions(+), 7 deletions(-) (limited to 'net/ipv4/route.c') diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 57e01bc60947..ca5e237df029 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1693,12 +1693,8 @@ 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 struct rtable *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; @@ -1707,19 +1703,29 @@ 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)) + if (check_peer_redir(&rt->dst, peer)) return NULL; } } rt->rt_peer_genid = rt_peer_genid(); } + return rt; +} + +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; + dst = (struct dst_entry *) ipv4_validate_peer(rt); return dst; } @@ -2374,6 +2380,9 @@ 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)) { + rth = ipv4_validate_peer(rth); + if (!rth) + continue; if (noref) { dst_use_noref(&rth->dst, jiffies); skb_dst_set_noref(skb, &rth->dst); @@ -2749,6 +2758,9 @@ 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)) { + rth = ipv4_validate_peer(rth); + if (!rth) + continue; dst_use(&rth->dst, jiffies); RT_CACHE_STAT_INC(out_hit); rcu_read_unlock_bh(); -- cgit v1.2.3