mbox series

[v5,net-next,0/4] Improve bind(addr, 0) behaviour.

Message ID 20200310080527.70180-1-kuniyu@amazon.co.jp
Headers show
Series Improve bind(addr, 0) behaviour. | expand

Message

Kuniyuki Iwashima March 10, 2020, 8:05 a.m. UTC 
Currently we fail to bind sockets to ephemeral ports when all of the ports
are exhausted even if all sockets have SO_REUSEADDR enabled. In this case,
we still have a chance to connect to the different remote hosts.

These patches add net.ipv4.ip_autobind_reuse option and fix the behaviour
to fully utilize all space of the local (addr, port) tuples.

---
Changes in v5:
  - Add more description to documents.
  - Fix sysctl option to use proc_dointvec_minmax.
  - Remove the Fixes: tag and squash two commits.

Changes in v4:
  - Add net.ipv4.ip_autobind_reuse option to not change the current behaviour.
  - Modify .gitignore for test.
  https://lore.kernel.org/netdev/20200308181615.90135-1-kuniyu@amazon.co.jp/

Changes in v3:
  - Change the title and write more specific description of the 3rd patch.
  - Add a test in tools/testing/selftests/net/ as the 4th patch.
  https://lore.kernel.org/netdev/20200229113554.78338-1-kuniyu@amazon.co.jp/

Changes in v2:
  - Change the description of the 2nd patch ('localhost' -> 'address').
  - Correct the description and the if statement of the 3rd patch.
  https://lore.kernel.org/netdev/20200226074631.67688-1-kuniyu@amazon.co.jp/

v1 with tests:
  https://lore.kernel.org/netdev/20200220152020.13056-1-kuniyu@amazon.co.jp/
---

Kuniyuki Iwashima (4):
  tcp: Remove unnecessary conditions in inet_csk_bind_conflict().
  tcp: bind(0) remove the SO_REUSEADDR restriction when ephemeral ports
    are exhausted.
  tcp: Forbid to bind more than one sockets haveing SO_REUSEADDR and
    SO_REUSEPORT per EUID.
  selftests: net: Add SO_REUSEADDR test to check if 4-tuples are fully
    utilized.

 Documentation/networking/ip-sysctl.txt        |   9 +
 include/net/netns/ipv4.h                      |   1 +
 net/ipv4/inet_connection_sock.c               |  36 ++--
 net/ipv4/sysctl_net_ipv4.c                    |   9 +
 tools/testing/selftests/net/.gitignore        |   1 +
 tools/testing/selftests/net/Makefile          |   2 +
 .../selftests/net/reuseaddr_ports_exhausted.c | 162 ++++++++++++++++++
 .../net/reuseaddr_ports_exhausted.sh          |  35 ++++
 8 files changed, 243 insertions(+), 12 deletions(-)
 create mode 100644 tools/testing/selftests/net/reuseaddr_ports_exhausted.c
 create mode 100755 tools/testing/selftests/net/reuseaddr_ports_exhausted.sh