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set fake_rtable's dst to NULL to avoid kernel Oops.

PATCH Superseded Peter Huang(Peng) 2 participants 2 messages Apr 18, 2012

Subsystems (4)
Networking Network drivers netfilter Ethernet bridge

v2 of 4 Superseded Latest is v4 →

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Peter Huang(Peng)

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#0 lore raw

PATCH v2 1/1 set fake_rtable's dst to NULL to avoid kernel Oops.

Add new flag DST_FAKE_RTABLE to dst_entry struct.

Acked-by Eric Dumazet <[email protected]>
Signed-off-by Peter Huang <[email protected]>
---
 include/linux/netfilter_bridge.h |    8 ++++++++
 include/net/dst.h                |    1 +
 net/bridge/br_forward.c          |    1 +
 net/bridge/br_netfilter.c        |    8 ++------
 4 files changed, 12 insertions(+), 6 deletions(-)
include/linux/netfilter_bridge.h +8 -0
index 0ddd161..eb09e3b 100644
@@ -104,9 +104,17 @@ struct bridge_skb_cb {
        } daddr;
 };
 
+static inline void br_drop_fake_rtable(struct sk_buff *skb) {
+       struct dst_entry *dst = skb_dst(skb);
+       /* abuse fact that only fake_rtable has DST_FAKE_RTABLE set */
+       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)               (0)
 #endif /* CONFIG_BRIDGE_NETFILTER */
 
 #endif /* __KERNEL__ */
include/net/dst.h +1 -0
index 59c5d18..b094030 100644
@@ -55,6 +55,7 @@ struct dst_entry {
 #define DST_NOCACHE            0x0010
 #define DST_NOCOUNT            0x0020
 #define DST_NOPEER             0x0040
+#define DST_FAKE_RTABLE                0x0080
 
        short                   error;
        short                   obsolete;
net/bridge/br_forward.c +1 -0
index 61f6534..a2098e3 100644
@@ -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);
        }
net/bridge/br_netfilter.c +2 -6
index dec4f38..d7f49b6 100644
@@ -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;
 }
#1 lore raw
Quoted 2 lines · Peter Huang(Peng)

Add new flag DST_FAKE_RTABLE to dst_entry struct.

Your changelog is not very helpful. Please add all the information you provided in your previous mails. (stack trace and all)

Quoted 14 lines
Acked-by Eric Dumazet <[email protected]>
Signed-off-by Peter Huang <[email protected]>
---
  include/linux/netfilter_bridge.h |    8 ++++++++
  include/net/dst.h                |    1 +
  net/bridge/br_forward.c          |    1 +
  net/bridge/br_netfilter.c        |    8 ++------
  4 files changed, 12 insertions(+), 6 deletions(-)
include/linux/netfilter_bridge.h +0 -0
index 0ddd161..eb09e3b 100644

include/linux/netfilter_bridge.h struct bridge_skb_cb { · line 109

Quoted 6 lines
include/linux/netfilter_bridge.h +3 -0
@@ -104,9 +104,17 @@ struct bridge_skb_cb {
         } daddr;
  };
 
+static inline void br_drop_fake_rtable(struct sk_buff *skb) {
+       struct dst_entry *dst = skb_dst(skb);
+       /* abuse fact that only fake_rtable has DST_FAKE_RTABLE set */

You are kidding ? I said "Remove this comment, and leave an empty line"

include/linux/netfilter_bridge.h struct bridge_skb_cb { · line 112

Quoted 3 lines
include/linux/netfilter_bridge.h +3 -0
+       if (dst && (dst->flags & DST_FAKE_RTABLE))
+               skb_dst_drop(skb);
+}

Patch mangled, tabulations were replaced by spaces.

Please, please please read again Documentation/email-clients.txt, as I already mentioned (privately)

Double check _everything_ before your next submission

This is the last time I even care

Thanks