From: Cong Wang <xiyou.wangcong@gmail.com>
To: John Fastabend <john.fastabend@gmail.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Linux Kernel Network Developers <netdev@vger.kernel.org>,
bpf <bpf@vger.kernel.org>,
duanxiongchun@bytedance.com,
Dongdong Wang <wangdongdong.6@bytedance.com>,
Jiang Wang <jiang.wang@bytedance.com>,
Cong Wang <cong.wang@bytedance.com>
Subject: Re: [Patch bpf-next v7 00/13] sockmap: introduce BPF_SK_SKB_VERDICT and support UDP
Date: Mon, 29 Mar 2021 09:57:38 -0700 [thread overview]
Message-ID: <CAM_iQpV3d6_RMcuwF6BmR635og0=FUy7siN-0MNchR9_sXz2cg@mail.gmail.com> (raw)
In-Reply-To: <6061ec2bc63e0_3673a20848@john-XPS-13-9370.notmuch>
On Mon, Mar 29, 2021 at 8:03 AM John Fastabend <john.fastabend@gmail.com> wrote:
>
> Alexei Starovoitov wrote:
> > On Sun, Mar 28, 2021 at 01:20:00PM -0700, Cong Wang wrote:
> > > From: Cong Wang <cong.wang@bytedance.com>
> > >
> > > We have thousands of services connected to a daemon on every host
> > > via AF_UNIX dgram sockets, after they are moved into VM, we have to
> > > add a proxy to forward these communications from VM to host, because
> > > rewriting thousands of them is not practical. This proxy uses an
> > > AF_UNIX socket connected to services and a UDP socket to connect to
> > > the host. It is inefficient because data is copied between kernel
> > > space and user space twice, and we can not use splice() which only
> > > supports TCP. Therefore, we want to use sockmap to do the splicing
> > > without going to user-space at all (after the initial setup).
> > >
> > > Currently sockmap only fully supports TCP, UDP is partially supported
> > > as it is only allowed to add into sockmap. This patchset, as the second
> > > part of the original large patchset, extends sockmap with:
> > > 1) cross-protocol support with BPF_SK_SKB_VERDICT; 2) full UDP support.
> > >
> > > On the high level, ->read_sock() is required for each protocol to support
> > > sockmap redirection, and in order to do sock proto update, a new ops
> > > ->psock_update_sk_prot() is introduced, which is also required. And the
> > > BPF ->recvmsg() is also needed to replace the original ->recvmsg() to
> > > retrieve skmsg. To make life easier, we have to get rid of lock_sock()
> > > in sk_psock_handle_skb(), otherwise we would have to implement
> > > ->sendmsg_locked() on top of ->sendmsg(), which is ugly.
> > >
> > > Please see each patch for more details.
> > >
> > > To see the big picture, the original patchset is available here:
> > > https://github.com/congwang/linux/tree/sockmap
> > > this patchset is also available:
> > > https://github.com/congwang/linux/tree/sockmap2
> > >
> > > ---
> > > v7: use work_mutex to protect psock->work
> > > return err in udp_read_sock()
> > > add patch 6/13
> > > clean up test case
> >
> > The feature looks great to me.
> > I think the selftest is a bit light in terms of coverage, but it's acceptable.
>
> +1
Well, the first half of this patchset still focuses on the existing code, which
is already covered by existing test cases. The second half adds
BPF_SK_SKB_VERDICT and UDP support, which are already covered by
my new test case. And apparently UDP will never support other sockmap
programs like TCP, for example, BPF_SK_SKB_STREAM_PARSER, hence
it of course has much less test cases than TCP. Cross-protocol test case
will be added in the next patchset when AF_UNIX comes in.
If I miss anything, please be specific. Just saying the test case is light does
not help me to understand what I need to add.
Thanks.
prev parent reply other threads:[~2021-03-29 16:58 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-28 20:20 [Patch bpf-next v7 00/13] sockmap: introduce BPF_SK_SKB_VERDICT and support UDP Cong Wang
2021-03-28 20:20 ` [Patch bpf-next v7 01/13] skmsg: lock ingress_skb when purging Cong Wang
2021-03-28 20:20 ` [Patch bpf-next v7 02/13] skmsg: introduce a spinlock to protect ingress_msg Cong Wang
2021-03-29 19:11 ` John Fastabend
2021-03-28 20:20 ` [Patch bpf-next v7 03/13] net: introduce skb_send_sock() for sock_map Cong Wang
2021-03-28 20:20 ` [Patch bpf-next v7 04/13] skmsg: avoid lock_sock() in sk_psock_backlog() Cong Wang
2021-03-29 19:41 ` John Fastabend
2021-03-28 20:20 ` [Patch bpf-next v7 05/13] skmsg: use rcu work for destroying psock Cong Wang
2021-03-29 19:42 ` John Fastabend
2021-03-28 20:20 ` [Patch bpf-next v7 06/13] skmsg: use GFP_KERNEL in sk_psock_create_ingress_msg() Cong Wang
2021-03-29 19:44 ` John Fastabend
2021-03-28 20:20 ` [Patch bpf-next v7 07/13] sock_map: introduce BPF_SK_SKB_VERDICT Cong Wang
2021-03-29 20:09 ` John Fastabend
2021-03-30 1:27 ` Cong Wang
2021-03-28 20:20 ` [Patch bpf-next v7 08/13] sock: introduce sk->sk_prot->psock_update_sk_prot() Cong Wang
2021-03-28 20:20 ` [Patch bpf-next v7 09/13] udp: implement ->read_sock() for sockmap Cong Wang
2021-03-29 20:54 ` John Fastabend
2021-03-30 5:39 ` Cong Wang
2021-03-30 6:23 ` John Fastabend
2021-03-30 6:36 ` Cong Wang
2021-03-30 6:45 ` John Fastabend
2021-03-28 20:20 ` [Patch bpf-next v7 10/13] skmsg: extract __tcp_bpf_recvmsg() and tcp_bpf_wait_data() Cong Wang
2021-03-28 20:20 ` [Patch bpf-next v7 11/13] udp: implement udp_bpf_recvmsg() for sockmap Cong Wang
2021-03-28 20:20 ` [Patch bpf-next v7 12/13] sock_map: update sock type checks for UDP Cong Wang
2021-03-29 23:10 ` John Fastabend
2021-03-30 5:47 ` Cong Wang
2021-03-28 20:20 ` [Patch bpf-next v7 13/13] selftests/bpf: add a test case for udp sockmap Cong Wang
2021-03-28 23:27 ` [Patch bpf-next v7 00/13] sockmap: introduce BPF_SK_SKB_VERDICT and support UDP Alexei Starovoitov
2021-03-29 15:03 ` John Fastabend
2021-03-29 16:57 ` Cong Wang [this message]
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