mbox series

[liburing,v2,00/12] Introducing t_bind_ephemeral_port() function

Message ID 20220902071153.3168814-1-ammar.faizi@intel.com (mailing list archive)
Headers show
Series Introducing t_bind_ephemeral_port() function | expand

Message

Ammar Faizi Sept. 2, 2022, 7:14 a.m. UTC 
From: Ammar Faizi <ammarfaizi2@gnuweeb.org>

Hi,

This is revision v2 of "Introducing t_bind_ephemeral_port() function".
After discussing an intermittent bind() issue with Dylan, I decided to
introduce a new helper function, t_bind_ephemeral_port().

## Problem:
We have many places where we need to bind() a socket to any unused port
number. To achieve that, the current approach does one of the following
mechanisms:

  1) Randomly brute force the port number until the bind() syscall
     succeeds.

  2) Use a static port at compile time (randomly chosen too).

This is not reliable and it results in an intermittent issue (test
fails when the selected port is in use).

## Solution:
Setting @addr->sin_port to zero on a bind() syscall lets the kernel
choose a port number that is not in use. The caller then can know the
port number to be bound by invoking a getsockname() syscall after
bind() succeeds.

Wrap this procedure in a new function called t_bind_ephemeral_port().
The selected port will be returned into @addr->sin_port, the caller
can use it later to connect() or whatever they need.

## Patchset summary:
There are 12 patches in this series, summary:
1) Patch #1 introduces a new helper function t_bind_ephemeral_port().
2) Patch #2 to #6 get rid of the port number brute force mechanism.
3) Patch #7 to #12 stop using a static port number.

## Changelog

  v1 -> v2:
    - Fix variable placement in patch #2.
    - Append Reviewed-by tags from Alviro.
    - Append Tested-by tags from Alviro.

Link: https://lore.kernel.org/r/918facd1-78ba-2de7-693a-5f8c65ea2fcd@gnuweeb.org
Cc: Dylan Yudaken <dylany@fb.com>
Cc: Facebook Kernel Team <kernel-team@fb.com>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
---

Ammar Faizi (12):
  test/helpers: Add `t_bind_ephemeral_port()` function
  t/poll-link: Don't brute force the port number
  t/socket-rw: Don't brute force the port number
  t/socket-rw-eagain: Don't brute force the port number
  t/socket-rw-offset: Don't brute force the port number
  t/files-exit-hang-poll: Don't brute force the port number
  t/socket: Don't use a static port number
  t/connect: Don't use a static port number
  t/shutdown: Don't use a static port number
  t/recv-msgall: Don't use a static port number
  t/232c93d07b74: Don't use a static port number
  t/recv-msgall-stream: Don't use a static port number

 test/232c93d07b74.c         | 10 ++++------
 test/accept.c               |  5 +----
 test/files-exit-hang-poll.c | 23 +++--------------------
 test/helpers.c              | 18 ++++++++++++++++++
 test/helpers.h              |  7 +++++++
 test/poll-link.c            | 27 +++++++++------------------
 test/recv-msgall-stream.c   | 22 ++++++++++------------
 test/recv-msgall.c          | 10 ++++------
 test/shutdown.c             |  7 +++----
 test/socket-rw-eagain.c     | 14 ++------------
 test/socket-rw-offset.c     | 13 ++-----------
 test/socket-rw.c            | 13 ++-----------
 test/socket.c               | 11 ++++++-----
 13 files changed, 71 insertions(+), 109 deletions(-)


base-commit: b8c37f02662faa4f2b61840b123201ccc5678fb1

Comments

Jens Axboe Sept. 2, 2022, 11:57 a.m. UTC | #1 
On Fri, 2 Sep 2022 14:14:53 +0700, Ammar Faizi wrote:
> From: Ammar Faizi <ammarfaizi2@gnuweeb.org>
> 
> Hi,
> 
> This is revision v2 of "Introducing t_bind_ephemeral_port() function".
> After discussing an intermittent bind() issue with Dylan, I decided to
> introduce a new helper function, t_bind_ephemeral_port().
> 
> [...]

Applied, thanks!

[01/12] test/helpers: Add `t_bind_ephemeral_port()` function
        commit: 0a2d0af5c1d7daa77bacc203d28a7a79662a928e
[02/12] t/poll-link: Don't brute force the port number
        commit: 6341145b6fe368d123ced2ba9857b3105673f644
[03/12] t/socket-rw: Don't brute force the port number
        commit: e0f0f04de43447c69f442532f5c4d72e9a833481
[04/12] t/socket-rw-eagain: Don't brute force the port number
        commit: 156ef697a9af0efd2e2e0d210de43e45e620fc76
[05/12] t/socket-rw-offset: Don't brute force the port number
        commit: ac7f81db44fc658bb7b99cceb1bee738890a317e
[06/12] t/files-exit-hang-poll: Don't brute force the port number
        commit: ce419aa629af36c0e0b19c155ef385e58bd8f9c8
[07/12] t/socket: Don't use a static port number
        commit: 875630a00f64ede24bf3cd7b3df4a37c45de65e0
[08/12] t/connect: Don't use a static port number
        commit: 7ce01375835e57a47c46be9646f773be1a8d8c3c
[09/12] t/shutdown: Don't use a static port number
        commit: 4736c9392bb910ae5a7d965f1019070864f831d3
[10/12] t/recv-msgall: Don't use a static port number
        commit: 2f8d4bb4259c6e3b6c519c03385c86f14e619ed9
[11/12] t/232c93d07b74: Don't use a static port number
        commit: fab19e78737fd65a411a446b848d427af6706c0e
[12/12] t/recv-msgall-stream: Don't use a static port number
        commit: c93f347ccaeb68c1aa4b377658555f0c7c2576b2

Best regards,