Re: [PATCH net-next 1/3] ipv4: properly refresh rtable entries on pmtu/redirect events
From: Julian Anastasov <ja@ssi.bg>
Date: 2013-05-28 08:22:20
Hello, On Tue, 28 May 2013, Timo Teräs wrote:
This reverts commit 05ab86c5 (xfrm4: Invalidate all ipv4 routes on IPsec pmtu events). Flushing all cached entries is not needed. Instead, invalidate only the related next hop dsts to recheck for the added next hop exception where needed. This also fixes a subtle race due to bumping generation id's before updating the pmtu. Cc: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Timo Teräs <redacted> ---
quoted hunk ↗ jump to hunk
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 550781a..561a378 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c@@ -594,11 +594,25 @@ static inline u32 fnhe_hashfun(__be32 daddr) return hval & (FNHE_HASH_SIZE - 1); } +static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) +{ + rt->rt_pmtu = fnhe->fnhe_pmtu; + rt->dst.expires = fnhe->fnhe_expires;
The 'if (time_before' ... dst_set_expires() logic from rt_bind_exception() is removed, may be it should be moved here, i.e. fnhe_pmtu should be ignored if expired.
quoted hunk ↗ jump to hunk
@@ -627,8 +641,12 @@ static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, fnhe->fnhe_gw = gw; if (pmtu) { fnhe->fnhe_pmtu = pmtu; - fnhe->fnhe_expires = expires; + fnhe->fnhe_expires = max(1UL, expires); } + /* Update all cached dsts too */ + rt = rcu_dereference(fnhe->fnhe_rth);
rt = rcu_dereference_protected(fnhe->fnhe_rth, 1); Regards -- Julian Anastasov [off-list ref]