mbox series

[net-next,v2,0/2] Add IP_LOCAL_PORT_RANGE socket option

Message ID 20221221-sockopt-port-range-v2-0-1d5f114bf627@cloudflare.com (mailing list archive)
Headers show
Series Add IP_LOCAL_PORT_RANGE socket option | expand

Message

Jakub Sitnicki Jan. 10, 2023, 1:37 p.m. UTC 
This patch set is a follow up to the "How to share IPv4 addresses by
partitioning the port space" talk given at LPC 2022 [1].

Please see patch #1 for the motivation & the use case description.
Patch #2 adds tests exercising the new option in various scenarios.

Documentation
-------------

Proposed update to the ip(7) man-page:

       IP_LOCAL_PORT_RANGE (since Linux X.Y)
              Set or get the per-socket default local port range. This
              option  can  be used to clamp down the global local port
              range, defined by the ip_local_port_range  /proc  inter‐
              face described below, for a given socket.

              The option takes an uint32_t value with the high 16 bits
              set to the upper range bound, and the low 16 bits set to
              the lower range bound. Range bounds are inclusive.

              The lower bound has to be less than the upper bound when
              both bounds are not zero. Otherwise, setting the  option
              fails with EINVAL.

              If  either  bound  is  outside  of the global local port
              range, or is zero, then that bound has no effect.

              To reset the setting, pass zero as both  the  upper  and
              the lower bound.

Changelog:
---------

v1 -> v2:
v1: https://lore.kernel.org/netdev/20221221-sockopt-port-range-v1-0-e2b094b60ffd@cloudflare.com/

 * Fix the corner case when the per-socket range doesn't overlap with the
   per-netns range. Fallback correctly to the per-netns range. (Kuniyuki)

 * selftests: Instead of iterating over socket families (ip4, ip6) and types
   (tcp, udp), generate tests for each combo from a template. This keeps the
   code indentation level down and makes tests more granular.

 * Rewrite man-page prose:
   - explain how to unset the option,
   - document when EINVAL is returned.

RFC -> v1
RFC: https://lore.kernel.org/netdev/20220912225308.93659-1-jakub@cloudflare.com/

 * Allow either the high bound or the low bound, or both, to be zero
 * Add getsockopt support
 * Add selftests

Links:
------

[1]: https://lpc.events/event/16/contributions/1349/

To: netdev@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: kernel-team@cloudflare.com
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>

---
Jakub Sitnicki (2):
      inet: Add IP_LOCAL_PORT_RANGE socket option
      selftests/net: Cover the IP_LOCAL_PORT_RANGE socket option

 include/net/inet_sock.h                            |   4 +
 include/net/ip.h                                   |   3 +-
 include/uapi/linux/in.h                            |   1 +
 net/ipv4/inet_connection_sock.c                    |  25 +-
 net/ipv4/inet_hashtables.c                         |   2 +-
 net/ipv4/ip_sockglue.c                             |  18 +
 net/ipv4/udp.c                                     |   2 +-
 tools/testing/selftests/net/Makefile               |   2 +
 tools/testing/selftests/net/ip_local_port_range.c  | 439 +++++++++++++++++++++
 tools/testing/selftests/net/ip_local_port_range.sh |   5 +
 10 files changed, 496 insertions(+), 5 deletions(-)
---
base-commit: a3ae16030a0320229df10cedfeff1f80df26ee76
change-id: 20221221-sockopt-port-range-e142de700f4d

Best regards,