From: Jakub Sitnicki <jakub@cloudflare.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org,
duanxiongchun@bytedance.com, wangdongdong.6@bytedance.com,
jiang.wang@bytedance.com, Cong Wang <cong.wang@bytedance.com>,
John Fastabend <john.fastabend@gmail.com>,
Daniel Borkmann <daniel@iogearbox.net>,
Lorenz Bauer <lmb@cloudflare.com>
Subject: Re: [Patch bpf-next v8 10/16] sock: introduce sk->sk_prot->psock_update_sk_prot()
Date: Fri, 02 Apr 2021 12:16:36 +0200 [thread overview]
Message-ID: <87sg492dq3.fsf@cloudflare.com> (raw)
In-Reply-To: <20210331023237.41094-11-xiyou.wangcong@gmail.com>
On Wed, Mar 31, 2021 at 04:32 AM CEST, Cong Wang wrote:
> From: Cong Wang <cong.wang@bytedance.com>
>
> Currently sockmap calls into each protocol to update the struct
> proto and replace it. This certainly won't work when the protocol
> is implemented as a module, for example, AF_UNIX.
>
> Introduce a new ops sk->sk_prot->psock_update_sk_prot(), so each
> protocol can implement its own way to replace the struct proto.
> This also helps get rid of symbol dependencies on CONFIG_INET.
>
> Cc: John Fastabend <john.fastabend@gmail.com>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Jakub Sitnicki <jakub@cloudflare.com>
> Cc: Lorenz Bauer <lmb@cloudflare.com>
> Signed-off-by: Cong Wang <cong.wang@bytedance.com>
> ---
[...]
> diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
> index 4a0478b17243..38952aaee3a1 100644
> --- a/net/ipv4/udp.c
> +++ b/net/ipv4/udp.c
> @@ -2849,6 +2849,9 @@ struct proto udp_prot = {
> .unhash = udp_lib_unhash,
> .rehash = udp_v4_rehash,
> .get_port = udp_v4_get_port,
> +#ifdef CONFIG_BPF_SYSCALL
> + .psock_update_sk_prot = udp_bpf_update_proto,
> +#endif
> .memory_allocated = &udp_memory_allocated,
> .sysctl_mem = sysctl_udp_mem,
> .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
> diff --git a/net/ipv4/udp_bpf.c b/net/ipv4/udp_bpf.c
> index 7a94791efc1a..6001f93cd3a0 100644
> --- a/net/ipv4/udp_bpf.c
> +++ b/net/ipv4/udp_bpf.c
> @@ -41,12 +41,23 @@ static int __init udp_bpf_v4_build_proto(void)
> }
> core_initcall(udp_bpf_v4_build_proto);
>
> -struct proto *udp_bpf_get_proto(struct sock *sk, struct sk_psock *psock)
> +int udp_bpf_update_proto(struct sock *sk, bool restore)
> {
> int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6;
> + struct sk_psock *psock = sk_psock(sk);
> +
> + if (restore) {
> + sk->sk_write_space = psock->saved_write_space;
> + /* Pairs with lockless read in sk_clone_lock() */
Just to clarify. UDP sockets don't get cloned, so the above comment
apply.
> + WRITE_ONCE(sk->sk_prot, psock->sk_proto);
> + return 0;
> + }
>
> if (sk->sk_family == AF_INET6)
> udp_bpf_check_v6_needs_rebuild(psock->sk_proto);
>
> - return &udp_bpf_prots[family];
> + /* Pairs with lockless read in sk_clone_lock() */
> + WRITE_ONCE(sk->sk_prot, &udp_bpf_prots[family]);
> + return 0;
> }
> +EXPORT_SYMBOL_GPL(udp_bpf_update_proto);
[...]
next prev parent reply other threads:[~2021-04-02 10:16 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-31 2:32 [Patch bpf-next v8 00/16] sockmap: introduce BPF_SK_SKB_VERDICT and support UDP Cong Wang
2021-03-31 2:32 ` [Patch bpf-next v8 01/16] skmsg: lock ingress_skb when purging Cong Wang
2021-03-31 22:00 ` John Fastabend
2021-03-31 2:32 ` [Patch bpf-next v8 02/16] skmsg: introduce a spinlock to protect ingress_msg Cong Wang
2021-03-31 2:32 ` [Patch bpf-next v8 03/16] net: introduce skb_send_sock() for sock_map Cong Wang
2021-04-01 8:10 ` Jakub Sitnicki
2021-03-31 2:32 ` [Patch bpf-next v8 04/16] skmsg: avoid lock_sock() in sk_psock_backlog() Cong Wang
2021-03-31 2:32 ` [Patch bpf-next v8 05/16] skmsg: use rcu work for destroying psock Cong Wang
2021-03-31 2:32 ` [Patch bpf-next v8 06/16] skmsg: use GFP_KERNEL in sk_psock_create_ingress_msg() Cong Wang
2021-03-31 2:32 ` [Patch bpf-next v8 07/16] sock_map: simplify sock_map_link() a bit Cong Wang
2021-04-01 5:48 ` John Fastabend
2021-03-31 2:32 ` [Patch bpf-next v8 08/16] sock_map: kill sock_map_link_no_progs() Cong Wang
2021-03-31 2:32 ` [Patch bpf-next v8 09/16] sock_map: introduce BPF_SK_SKB_VERDICT Cong Wang
2021-04-01 5:51 ` John Fastabend
2021-03-31 2:32 ` [Patch bpf-next v8 10/16] sock: introduce sk->sk_prot->psock_update_sk_prot() Cong Wang
2021-04-02 10:16 ` Jakub Sitnicki [this message]
2021-04-03 5:13 ` Cong Wang
2021-04-05 8:25 ` Eric Dumazet
2021-04-06 18:12 ` John Fastabend
2021-04-06 18:30 ` Cong Wang
2021-04-06 21:07 ` John Fastabend
2021-03-31 2:32 ` [Patch bpf-next v8 11/16] udp: implement ->read_sock() for sockmap Cong Wang
2021-04-01 6:00 ` John Fastabend
2021-04-03 5:08 ` Cong Wang
2021-04-03 6:45 ` Alexei Starovoitov
2021-03-31 2:32 ` [Patch bpf-next v8 12/16] skmsg: extract __tcp_bpf_recvmsg() and tcp_bpf_wait_data() Cong Wang
2021-04-01 16:36 ` John Fastabend
2021-03-31 2:32 ` [Patch bpf-next v8 13/16] udp: implement udp_bpf_recvmsg() for sockmap Cong Wang
2021-04-01 16:24 ` John Fastabend
2021-03-31 2:32 ` [Patch bpf-next v8 14/16] sock_map: update sock type checks for UDP Cong Wang
2021-04-01 6:02 ` John Fastabend
2021-03-31 2:32 ` [Patch bpf-next v8 15/16] selftests/bpf: add a test case for udp sockmap Cong Wang
2021-03-31 2:32 ` [Patch bpf-next v8 16/16] selftests/bpf: add a test case for loading BPF_SK_SKB_VERDICT Cong Wang
2021-04-01 16:51 ` [Patch bpf-next v8 00/16] sockmap: introduce BPF_SK_SKB_VERDICT and support UDP John Fastabend
2021-04-01 18:03 ` Alexei Starovoitov
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