在 2019/12/20 18:31, Pablo Neira Ayuso 写道:
> On Fri, Dec 20, 2019 at 05:19:12PM +0800, wenxu wrote:
>> On 12/20/2019 5:13 PM, Pablo Neira Ayuso wrote:
>>> On Fri, Dec 20, 2019 at 11:53:38AM +0800, wenxu wrote:
>>>> Maybe the patch your suggestion is not correct?
>>>>
>>>> On 12/20/2019 6:18 AM, Pablo Neira Ayuso wrote:
>>>>> diff --git a/net/netfilter/nf_flow_table_offload.c b/net/netfilter/nf_flow_table_offload.c
>>>>> index 506aaaf8151d..8680fc56cd7c 100644
>>>>> --- a/net/netfilter/nf_flow_table_offload.c
>>>>> +++ b/net/netfilter/nf_flow_table_offload.c
>>>>> @@ -156,14 +156,14 @@ static int flow_offload_eth_dst(struct net *net,
>>>>> enum flow_offload_tuple_dir dir,
>>>>> struct nf_flow_rule *flow_rule)
>>>>> {
>>>>> - const struct flow_offload_tuple *tuple = &flow->tuplehash[dir].tuple;
>>>>> + const struct flow_offload_tuple *tuple = &flow->tuplehash[!dir].tuple;
>>>>> struct flow_action_entry *entry0 = flow_action_entry_next(flow_rule);
>>>>> struct flow_action_entry *entry1 = flow_action_entry_next(flow_rule);
>>>>> struct neighbour *n;
>>>>> u32 mask, val;
>>>>> u16 val16;
>>>>>
>>>>> - n = dst_neigh_lookup(tuple->dst_cache, &tuple->dst_v4);
>>>>> + n = dst_neigh_lookup(tuple->dst_cache, &tuple->src_v4);
>>>> The dst_cache should be flow->tuplehash[dir].tuple.dst_cache but not peer dir's;
>>> Hm, I think this is like your patch, but without the two extra new lines
>>> and new variable definitions.
>> There is a little bit different. The dst_cache should get from flow->tuplehash[dir].tuple.dst_cache
>>
>> but not flow->tuplehash[!dir].tuple.dst_cache
> SNAT mangling ether dst
> original A -> B C -> B [!dir].src
> reply B -> C B -> A [!dir].src
>
> DNAT mangling
> original A -> C A -> B [!dir].src
> reply B -> A C -> A [!dir].src
>
> SNAT+DNAT mangling
> original A -> C2 C1 -> B [!dir].src
> reply B -> C1 C2 -> A [!dir].src
yes, The daddr should always set as [!dir].src .
The problem I point out is the first parameters of dst_neigh_lookup, the
dst_entry used to find the gateway or daddr neighbor through dst_entry->dev.
This dst_entry should alway set as [dir].dst_entry.
For example :
DNAT mangling
original A -> C A -> B [!dir].src
reply B -> A C -> A [!dir].src
for the original dir: device receive from D1 and forward to D2,
So the mangle addr B([!dir].src) should do neigh lookup on D2([dir].dst_entry->dev)
BR
wenxu
>
