From: Jakub Sitnicki <jakub@cloudflare.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: 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>,
Daniel Borkmann <daniel@iogearbox.net>,
Lorenz Bauer <lmb@cloudflare.com>,
John Fastabend <john.fastabend@gmail.com>
Subject: Re: [Patch bpf-next v6 4/8] skmsg: move sk_redir from TCP_SKB_CB to skb
Date: Tue, 23 Feb 2021 19:36:57 +0100 [thread overview]
Message-ID: <874ki24omu.fsf@cloudflare.com> (raw)
In-Reply-To: <CAM_iQpWofNM=erfyP8b_qrezJN6d51UDW5bfgo2LHkPOTXqm8Q@mail.gmail.com>
On Tue, Feb 23, 2021 at 07:04 PM CET, Cong Wang wrote:
> On Tue, Feb 23, 2021 at 9:53 AM Jakub Sitnicki <jakub@cloudflare.com> wrote:
>> Based on what I've seen around, mask for sanitizing tagged pointers is
>> usually derived from the flag(s). For instance:
>>
>> #define SKB_DST_NOREF 1UL
>> #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
>>
>> #define SK_USER_DATA_NOCOPY 1UL
>> #define SK_USER_DATA_BPF 2UL /* Managed by BPF */
>> #define SK_USER_DATA_PTRMASK ~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF)
>>
>> Using ~(BPF_F_INGRESS) expression would be like substituting mask
>> definition.
>
> Yes, that is why I said we need a mask.
OK
>
>>
>> Alternatively we could clear _skb_refdest after clone, but before
>> enqueuing the skb in ingress_skb. And only for when we're redirecting.
>>
>> I believe that would be in sk_psock_skb_redirect, right before skb_queue_tail.
>
> Hmm? We definitely cannot clear skb->_sk_redir there, as it is used after
> enqueued in ingress_skb, that is in sk_psock_backlog().
You're right. I focused on the sk pointer and forgot it also carries the
ingress flag.
next prev parent reply other threads:[~2021-02-23 18:37 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-20 5:29 [Patch bpf-next v6 0/8] sock_map: clean up and refactor code for BPF_SK_SKB_VERDICT Cong Wang
2021-02-20 5:29 ` [Patch bpf-next v6 1/8] bpf: clean up sockmap related Kconfigs Cong Wang
2021-02-22 8:51 ` Jakub Sitnicki
2021-02-22 23:23 ` Cong Wang
2021-02-20 5:29 ` [Patch bpf-next v6 2/8] skmsg: get rid of struct sk_psock_parser Cong Wang
2021-02-20 5:29 ` [Patch bpf-next v6 3/8] bpf: compute data_end dynamically with JIT code Cong Wang
2021-02-20 5:29 ` [Patch bpf-next v6 4/8] skmsg: move sk_redir from TCP_SKB_CB to skb Cong Wang
2021-02-22 12:20 ` Jakub Sitnicki
2021-02-22 19:27 ` Cong Wang
2021-02-23 17:52 ` Jakub Sitnicki
2021-02-23 18:04 ` Cong Wang
2021-02-23 18:36 ` Jakub Sitnicki [this message]
2021-02-20 5:29 ` [Patch bpf-next v6 5/8] sock_map: rename skb_parser and skb_verdict Cong Wang
2021-02-22 12:28 ` Jakub Sitnicki
2021-02-22 19:32 ` Cong Wang
2021-02-20 5:29 ` [Patch bpf-next v6 6/8] sock_map: make sock_map_prog_update() static Cong Wang
2021-02-22 12:29 ` Jakub Sitnicki
2021-02-20 5:29 ` [Patch bpf-next v6 7/8] skmsg: make __sk_psock_purge_ingress_msg() static Cong Wang
2021-02-22 12:30 ` Jakub Sitnicki
2021-02-20 5:29 ` [Patch bpf-next v6 8/8] skmsg: get rid of sk_psock_bpf_run() Cong Wang
2021-02-22 12:31 ` Jakub Sitnicki
2021-02-22 12:32 ` [Patch bpf-next v6 0/8] sock_map: clean up and refactor code for BPF_SK_SKB_VERDICT Jakub Sitnicki
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=874ki24omu.fsf@cloudflare.com \
--to=jakub@cloudflare.com \
--cc=bpf@vger.kernel.org \
--cc=cong.wang@bytedance.com \
--cc=daniel@iogearbox.net \
--cc=duanxiongchun@bytedance.com \
--cc=jiang.wang@bytedance.com \
--cc=john.fastabend@gmail.com \
--cc=lmb@cloudflare.com \
--cc=netdev@vger.kernel.org \
--cc=wangdongdong.6@bytedance.com \
--cc=xiyou.wangcong@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.