On 2013/11/19 23:38, Vlad Yasevich wrote:
> On 11/19/2013 05:51 AM, Daniel Borkmann wrote:
>> Wang reported an issue that lksctp's test_getname_v6 seems to fail.
>>
>> The issue is that we do not copy sk_v6_rcv_saddr over to the new
>> socket, although the comment above says so regarding rcv_saddr.
>>
>> Commit 914e1c8b6980 ("sctp: Inherit all socket options from parent
>> correctly.") originally moved that over to sctp_copy_sock(), but
>> after commit efe4208f47f9 ("ipv6: make lookups simpler and faster")
>> this no longer holds and the actual value of sk_v6_rcv_saddr was
>> no longer being migrated.
>>
>> With this patch, the lksctp test suite passes again for IPv6.
>>
>> Fixes: efe4208f47f9 ("ipv6: make lookups simpler and faster")
>> Signed-off-by: Daniel Borkmann <dborkman@xxxxxxxxxx>
>> Signed-off-by: Wang Weidong <wangweidong1@xxxxxxxxxx>
>> Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
>> ---
>> net/sctp/ipv6.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
>> index 7567e6f..be08592 100644
>> --- a/net/sctp/ipv6.c
>> +++ b/net/sctp/ipv6.c
>> @@ -661,6 +661,7 @@ static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
>> * and getpeername().
>> */
>> sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
>> + newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
>>
>> sk_refcnt_debug_inc(newsk);
>>
>>
>
> This fixes the issue for the accept() case, but the bug is still there
> in the peeloff case.
>
> I think you should make sctp_copy_sock() use sock_copy() for now. It
> looks like it will catch all the cases.
>
I copied the part of the sock_copy() codes into sctp_v6_create_accept_sk instead of
sctp_copy_sock for testing. Like this:
--------------
@@ -645,7 +645,11 @@ static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
sock_init_data(NULL, newsk);
- sctp_copy_sock(newsk, sk, asoc);
+ memcpy(newsk, sk, offsetof(struct sock, sk_dontcopy_begin));
+
+ memcpy(&newsk->sk_dontcopy_end, &sk->sk_dontcopy_end,
+ sk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
+
sock_reset_flag(sk, SOCK_ZAPPED);
newsctp6sk = (struct sctp6_sock *)newsk;
--------------
when I did the test_getname_v6 of lksctp tools. It would hang. And I used the ps aux,
I can see the process got a D+ STAT.
BTW, I test it in the virtual machine.
So I think: when we use the sock_copy or which calls it, maybe we will get the problem here.
Is there I do something wrong?
Thanks.
> We can then look at possibly getting rid of sctp_copy_sock() for net-next.
>
> -vlad
>
>
>
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