From de68dca1816660b0d3ac89fa59ffb410007a143f Mon Sep 17 00:00:00 2001
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Sat, 26 Nov 2011 12:13:44 +0000
Subject: [PATCH] inet: add a redirect generation id in inetpeer
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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 <a.miskiewicz@gmail.com>
Tested-by: Arkadiusz Miśkiewicz <a.miskiewicz@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/net/inetpeer.h | 1 +
net/ipv4/route.c | 10 +++++++++-
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/include/net/inetpeer.h b/include/net/inetpeer.h
index 78c83e62218fb..e9ff3fc5e6886 100644
--- a/include/net/inetpeer.h
+++ b/include/net/inetpeer.h
@@ -35,6 +35,7 @@ struct inet_peer {
u32 metrics[RTAX_MAX];
u32 rate_tokens; /* rate limiting for ICMP */
+ int redirect_genid;
unsigned long rate_last;
unsigned long pmtu_expires;
u32 pmtu_orig;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index fb47c8f0cd86f..5c2847247f51b 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;
--
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