Re: [PATCH] ipv6: Fix problem with expired dst cache
From: Eric Dumazet <hidden>
Date: 2012-02-24 06:51:18
Le vendredi 24 février 2012 à 14:20 +0800, Gao feng a écrit :
if the ipv6 dst cache copy from the dst witch generated by ICMPV6 RA packet. this dst cache will not be checked expire because it has no RTF_EXPIRES flag So this dst cache always be used until the dst gc run. add a pointer in struct rt6_info,point to where the dst cache copy from. in func rt6_check_expired check if rt6->info->rt6i_copy is expired.
Sorry, I really dont understand what you are saying. Also, adding a pointer to a structure without holding a reference on it is suspicious.
quoted hunk ↗ jump to hunk
Signed-off-by: Gao feng <redacted> --- include/net/ip6_fib.h | 1 + net/ipv6/route.c | 16 ++++++++++++++-- 2 files changed, 15 insertions(+), 2 deletions(-)diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index b26bb81..3da4d58c 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h@@ -106,6 +106,7 @@ struct rt6_info { u32 rt6i_metric; u32 rt6i_peer_genid; + struct rt6_info *rt6i_copy; struct inet6_dev *rt6i_idev; struct inet_peer *rt6i_peer;diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 8c2e3ab..939d06a 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c@@ -316,8 +316,15 @@ static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, static __inline__ int rt6_check_expired(const struct rt6_info *rt) { - return (rt->rt6i_flags & RTF_EXPIRES) && - time_after(jiffies, rt->dst.expires); + if ((rt->rt6i_flags & RTF_EXPIRES) && + time_after(jiffies, rt->dst.expires)) + return 1; + + if (rt->rt6i_copy && (rt->rt6i_copy->rt6i_flags & RTF_EXPIRES) && + time_after(jiffies, rt->rt6i_copy->dst.expires)) + return 1; + + return 0; } static inline int rt6_need_strict(const struct in6_addr *daddr)@@ -1804,6 +1811,11 @@ static struct rt6_info *ip6_rt_copy(const struct rt6_info *ort, rt->rt6i_gateway = ort->rt6i_gateway; rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES; rt->rt6i_metric = 0; + + if (ort->rt6i_copy) + rt->rt6i_copy = ort->rt6i_copy; + else + rt->rt6i_copy = ort; #ifdef CONFIG_IPV6_SUBTREES memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));