From: John Fastabend <john.fastabend@gmail.com>
To: Cong Wang <xiyou.wangcong@gmail.com>, netdev@vger.kernel.org
Cc: 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>,
Jakub Sitnicki <jakub@cloudflare.com>,
Lorenz Bauer <lmb@cloudflare.com>
Subject: RE: [Patch bpf-next v8 11/16] udp: implement ->read_sock() for sockmap
Date: Wed, 31 Mar 2021 23:00:58 -0700 [thread overview]
Message-ID: <6065619aa26d1_938bb2085e@john-XPS-13-9370.notmuch> (raw)
In-Reply-To: <20210331023237.41094-12-xiyou.wangcong@gmail.com>
Cong Wang wrote:
> From: Cong Wang <cong.wang@bytedance.com>
>
> This is similar to tcp_read_sock(), except we do not need
> to worry about connections, we just need to retrieve skb
> from UDP receive queue.
>
> Note, the return value of ->read_sock() is unused in
> sk_psock_verdict_data_ready(), and UDP still does not
> support splice() due to lack of ->splice_read(), so users
> can not reach udp_read_sock() directly.
>
> 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>
> ---
Thanks this is easier to read IMO. One nit below.
Acked-by: John Fastabend <john.fastabend@gmail.com>
[...]
>
> +int udp_read_sock(struct sock *sk, read_descriptor_t *desc,
> + sk_read_actor_t recv_actor)
> +{
> + int copied = 0;
> +
> + while (1) {
> + struct sk_buff *skb;
> + int err, used;
> +
> + skb = skb_recv_udp(sk, 0, 1, &err);
> + if (!skb)
> + return err;
> + used = recv_actor(desc, skb, 0, skb->len);
> + if (used <= 0) {
> + if (!copied)
> + copied = used;
> + break;
> + } else if (used <= skb->len) {
> + copied += used;
> + }
This 'else if' is always true if above is false right? Would be
impler and clearer IMO as,
if (used <= 0) {
if (!copied)
copied = used;
break;
}
copied += used;
I don't see anyway for used to be great than skb->len.
> +
> + if (!desc->count)
> + break;
> + }
> +
> + return copied;
> +}
> +EXPORT_SYMBOL(udp_read_sock);
> +
next prev parent reply other threads:[~2021-04-01 6:01 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
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 [this message]
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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