[PATCH v4 net-next 0/5] udp: Introduce optional per-netns hash table.

[Kuniyuki Iwashima <kuniyu@amazon.com>]

This series is the UDP version of the per-netns ehash series [0],
which were initially in the same patch set. [1]

The notable difference with TCP is the max table size is 64K and the min
size is 128.  This is because the possible hash range by udp_hashfn()
always fits in 64K within the same netns and because we want to keep a
bitmap in udp_lib_get_port() on the stack.  Also, the UDP per-netns table
isolates both 1-tuple and 2-tuple tables.

For details, please see the last patch.

  patch 1 - 4: prep for per-netns hash table
  patch     5: add per-netns hash table

[0]: https://lore.kernel.org/netdev/20220908011022.45342-1-kuniyu@amazon.com/
[1]: https://lore.kernel.org/netdev/20220826000445.46552-1-kuniyu@amazon.com/


Changes:
  v4:
    * Drop a change to allcate bitmaps dynamically
    * Patch 5
      * Set the min size to 128 and keep the bitmap on stack (Paolo Abeni)
      * Add memset() in the proc handler (Paolo Abeni)

  v3: https://lore.kernel.org/netdev/20221111040034.29736-1-kuniyu@amazon.com/
    * Drop get_port() fix (posted separately later)
    * Patch 3
      * Fix CONFIG_PROC_FS=n build failure
    * Patch 5
      * Allocate bitmap when creating netns (Paolo Abeni)

  v2: https://lore.kernel.org/netdev/20221104190612.24206-1-kuniyu@amazon.com/

  v1: [1]


Kuniyuki Iwashima (5):
  udp: Clean up some functions.
  udp: Set NULL to sk->sk_prot->h.udp_table.
  udp: Set NULL to udp_seq_afinfo.udp_table.
  udp: Access &udp_table via net.
  udp: Introduce optional per-netns hash table.

 Documentation/networking/ip-sysctl.rst |  27 ++++
 include/linux/udp.h                    |   2 +
 include/net/netns/ipv4.h               |   3 +
 net/core/filter.c                      |   4 +-
 net/ipv4/sysctl_net_ipv4.c             |  40 +++++
 net/ipv4/udp.c                         | 196 ++++++++++++++++++++-----
 net/ipv4/udp_diag.c                    |   6 +-
 net/ipv4/udp_offload.c                 |   5 +-
 net/ipv6/udp.c                         |  31 ++--
 net/ipv6/udp_offload.c                 |   5 +-
 10 files changed, 261 insertions(+), 58 deletions(-)

-- 
2.30.2