netdev - Re: [Patch net-next] sock_map: dump socket map id via diag

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <32ab89e1-84e9-75f1-18c1-81db9a40d0bb@meta.com>
Date:   Sun, 12 Feb 2023 22:29:11 -0800
From:   Yonghong Song <yhs@...a.com>
To:     Cong Wang <xiyou.wangcong@...il.com>, netdev@...r.kernel.org
Cc:     bpf@...r.kernel.org, Cong Wang <cong.wang@...edance.com>,
        John Fastabend <john.fastabend@...il.com>,
        Jakub Sitnicki <jakub@...udflare.com>
Subject: Re: [Patch net-next] sock_map: dump socket map id via diag



On 2/11/23 12:19 PM, Cong Wang wrote:
> From: Cong Wang <cong.wang@...edance.com>
> 
> Currently there is no way to know which sockmap a socket has been added
> to from outside, especially for that a socket can be added to multiple
> sockmap's. We could dump this via socket diag, as shown below.
> 
> Sample output:
> 
>    # ./iproute2/misc/ss -tnaie --sockmap
>    ESTAB  0      344329     127.0.0.1:1234     127.0.0.1:40912 ino:21098 sk:5 cgroup:/user.slice/user-0.slice/session-c1.scope <-> sockmap: 1
> 
>    # bpftool map
>    1: sockmap  flags 0x0
>    	key 4B  value 4B  max_entries 2  memlock 4096B
> 	pids echo-sockmap(549)
>    4: array  name pid_iter.rodata  flags 0x480
> 	key 4B  value 4B  max_entries 1  memlock 4096B
> 	btf_id 10  frozen
> 	pids bpftool(624)
> 
> In the future, we could dump other sockmap related stats too, hence I
> make it a nested attribute.

Have you considered to implement a sockmap iterator? This will be
similar to existing hash/array/sk_local_storage map iterators. The
link below is the kernel implementation for sk_local_storage map
iterator which iterates through all sockets.
    https://lore.kernel.org/bpf/20200723184116.590602-1-yhs@fb.com

This way, in the future, if you want to print out more information
from the socket, no kernel change is needed and you can just adjust
your bpf program.

> 
> Cc: John Fastabend <john.fastabend@...il.com>
> Cc: Jakub Sitnicki <jakub@...udflare.com>
> Signed-off-by: Cong Wang <cong.wang@...edance.com>
> ---
>   include/linux/bpf.h            |  1 +
>   include/uapi/linux/inet_diag.h |  1 +
>   include/uapi/linux/sock_diag.h |  8 ++++++
>   include/uapi/linux/unix_diag.h |  1 +
>   net/core/sock_map.c            | 49 ++++++++++++++++++++++++++++++++++
>   net/ipv4/inet_diag.c           |  5 ++++
>   net/unix/diag.c                |  6 +++++
>   7 files changed, 71 insertions(+)
> 
[...]