From mboxrd@z Thu Jan 1 00:00:00 1970 From: wangweidong Subject: Re: [PATCH net] net: sctp: fix copying sk_v6_rcv_saddr in sctp_v6_create_accept_sk Date: Thu, 21 Nov 2013 14:49:57 +0800 Message-ID: <528DAD15.20901@huawei.com> References: <1384858284-2246-1-git-send-email-dborkman@redhat.com> <528B85E2.5080403@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Cc: , , Eric Dumazet To: Vlad Yasevich , Daniel Borkmann , Return-path: Received: from szxga01-in.huawei.com ([119.145.14.64]:11149 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750805Ab3KUGuY (ORCPT ); Thu, 21 Nov 2013 01:50:24 -0500 In-Reply-To: <528B85E2.5080403@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: 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 >> Signed-off-by: Wang Weidong >> Cc: Eric Dumazet >> --- >> 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 > > >