linux/include/net/sctp
Xin Long b0e9a2fe3f sctp: add support for SCTP_REUSE_PORT sockopt
This feature is actually already supported by sk->sk_reuse which can be
set by socket level opt SO_REUSEADDR. But it's not working exactly as
RFC6458 demands in section 8.1.27, like:

  - This option only supports one-to-one style SCTP sockets
  - This socket option must not be used after calling bind()
    or sctp_bindx().

Besides, SCTP_REUSE_PORT sockopt should be provided for user's programs.
Otherwise, the programs with SCTP_REUSE_PORT from other systems will not
work in linux.

To separate it from the socket level version, this patch adds 'reuse' in
sctp_sock and it works pretty much as sk->sk_reuse, but with some extra
setup limitations that are needed when it is being enabled.

"It should be noted that the behavior of the socket-level socket option
to reuse ports and/or addresses for SCTP sockets is unspecified", so it
leaves SO_REUSEADDR as is for the compatibility.

Note that the name SCTP_REUSE_PORT is somewhat confusing, as its
functionality is nearly identical to SO_REUSEADDR, but with some
extra restrictions. Here it uses 'reuse' in sctp_sock instead of
'reuseport'. As for sk->sk_reuseport support for SCTP, it will be
added in another patch.

Thanks to Neil to make this clear.

v1->v2:
  - add sctp_sk->reuse to separate it from the socket level version.
v2->v3:
  - improve changelog according to Marcelo's suggestion.

Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-29 22:20:55 +09:00
..
auth.h sctp: add sockopt SCTP_AUTH_DEACTIVATE_KEY 2018-03-14 13:48:27 -04:00
checksum.h sctp: force the params with right types for sctp csum apis 2017-11-28 11:00:13 -05:00
command.h sctp: add SCTP_AUTH_NO_AUTH type for AUTHENTICATION_EVENT 2018-03-14 13:48:27 -04:00
constants.h sctp: remove old and unused SCTP_MIN_PMTU 2018-04-27 14:35:22 -04:00
sctp.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
sm.h sctp: allow sctp_init_cause to return errors 2018-05-01 12:09:35 -04:00
stream_interleave.h sctp: implement handle_ftsn for sctp_stream_interleave 2017-12-15 13:52:22 -05:00
stream_sched.h sctp: remove extern from stream sched 2017-11-28 11:00:13 -05:00
structs.h sctp: add support for SCTP_REUSE_PORT sockopt 2018-06-29 22:20:55 +09:00
tsnmap.h
ulpevent.h sctp: implement abort_pd for sctp_stream_interleave 2017-12-11 11:23:05 -05:00
ulpqueue.h sctp: add support for the process of unordered idata 2017-12-11 11:23:05 -05:00