From 1716a96101c49186bb0b8491922fd3e69030235f Mon Sep 17 00:00:00 2001 From: Gao feng Date: Fri, 6 Apr 2012 00:13:10 +0000 Subject: ipv6: fix problem with expired dst cache If the ipv6 dst cache which copy from the dst generated by ICMPV6 RA packet. this dst cache will not check expire because it has no RTF_EXPIRES flag. So this dst cache will always be used until the dst gc run. Change the struct dst_entry,add a union contains new pointer from and expires. When rt6_info.rt6i_flags has no RTF_EXPIRES flag,the dst.expires has no use. we can use this field to point to where the dst cache copy from. The dst.from is only used in IPV6. rt6_check_expired check if rt6_info.dst.from is expired. ip6_rt_copy only set dst.from when the ort has flag RTF_ADDRCONF and RTF_DEFAULT.then hold the ort. ip6_dst_destroy release the ort. Add some functions to operate the RTF_EXPIRES flag and expires(from) together. and change the code to use these new adding functions. Changes from v5: modify ip6_route_add and ndisc_router_discovery to use new adding functions. Only set dst.from when the ort has flag RTF_ADDRCONF and RTF_DEFAULT.then hold the ort. Signed-off-by: Gao feng Signed-off-by: David S. Miller --- include/net/dst.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'include/net/dst.h') diff --git a/include/net/dst.h b/include/net/dst.h index 59c5d18cc38..ff4da42fcfc 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -36,7 +36,11 @@ struct dst_entry { struct net_device *dev; struct dst_ops *ops; unsigned long _metrics; - unsigned long expires; + union { + unsigned long expires; + /* point to where the dst_entry copied from */ + struct dst_entry *from; + }; struct dst_entry *path; struct neighbour __rcu *_neighbour; #ifdef CONFIG_XFRM -- cgit v1.2.3-70-g09d2 From a881e963c7fe1f226e991ee9bbe8907acda93294 Mon Sep 17 00:00:00 2001 From: "Peter Huang (Peng)" Date: Thu, 19 Apr 2012 20:12:51 +0000 Subject: set fake_rtable's dst to NULL to avoid kernel Oops bridge: set fake_rtable's dst to NULL to avoid kernel Oops when bridge is deleted before tap/vif device's delete, kernel may encounter an oops because of NULL reference to fake_rtable's dst. Set fake_rtable's dst to NULL before sending packets out can solve this problem. v4 reformat, change br_drop_fake_rtable(skb) to {} v3 enrich commit header v2 introducing new flag DST_FAKE_RTABLE to dst_entry struct. [ Use "do { } while (0)" for nop br_drop_fake_rtable() implementation -DaveM ] Acked-by: Eric Dumazet Signed-off-by: Peter Huang Signed-off-by: David S. Miller --- include/linux/netfilter_bridge.h | 9 +++++++++ include/net/dst.h | 1 + net/bridge/br_forward.c | 1 + net/bridge/br_netfilter.c | 8 ++------ 4 files changed, 13 insertions(+), 6 deletions(-) (limited to 'include/net/dst.h') diff --git a/include/linux/netfilter_bridge.h b/include/linux/netfilter_bridge.h index 0ddd161f3b0..31d2844e657 100644 --- a/include/linux/netfilter_bridge.h +++ b/include/linux/netfilter_bridge.h @@ -104,9 +104,18 @@ struct bridge_skb_cb { } daddr; }; +static inline void br_drop_fake_rtable(struct sk_buff *skb) +{ + struct dst_entry *dst = skb_dst(skb); + + if (dst && (dst->flags & DST_FAKE_RTABLE)) + skb_dst_drop(skb); +} + #else #define nf_bridge_maybe_copy_header(skb) (0) #define nf_bridge_pad(skb) (0) +#define br_drop_fake_rtable(skb) do { } while (0) #endif /* CONFIG_BRIDGE_NETFILTER */ #endif /* __KERNEL__ */ diff --git a/include/net/dst.h b/include/net/dst.h index ff4da42fcfc..bed833d9796 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -59,6 +59,7 @@ struct dst_entry { #define DST_NOCACHE 0x0010 #define DST_NOCOUNT 0x0020 #define DST_NOPEER 0x0040 +#define DST_FAKE_RTABLE 0x0080 short error; short obsolete; diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c index 61f65344e71..a2098e3de50 100644 --- a/net/bridge/br_forward.c +++ b/net/bridge/br_forward.c @@ -47,6 +47,7 @@ int br_dev_queue_push_xmit(struct sk_buff *skb) kfree_skb(skb); } else { skb_push(skb, ETH_HLEN); + br_drop_fake_rtable(skb); dev_queue_xmit(skb); } diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index dec4f381713..d7f49b63ab0 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -156,7 +156,7 @@ void br_netfilter_rtable_init(struct net_bridge *br) rt->dst.dev = br->dev; rt->dst.path = &rt->dst; dst_init_metrics(&rt->dst, br_dst_default_metrics, true); - rt->dst.flags = DST_NOXFRM | DST_NOPEER; + rt->dst.flags = DST_NOXFRM | DST_NOPEER | DST_FAKE_RTABLE; rt->dst.ops = &fake_dst_ops; } @@ -694,11 +694,7 @@ static unsigned int br_nf_local_in(unsigned int hook, struct sk_buff *skb, const struct net_device *out, int (*okfn)(struct sk_buff *)) { - struct rtable *rt = skb_rtable(skb); - - if (rt && rt == bridge_parent_rtable(in)) - skb_dst_drop(skb); - + br_drop_fake_rtable(skb); return NF_ACCEPT; } -- cgit v1.2.3-70-g09d2