Commit Graph

639 Commits

Author SHA1 Message Date
Christoph Hellwig
3f49f72035 sctp: pass a kernel pointer to sctp_setsockopt_reconfig_supported
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:43 -07:00
Christoph Hellwig
ac37435bfe sctp: pass a kernel pointer to sctp_setsockopt_default_prinfo
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:43 -07:00
Christoph Hellwig
4a97fa4f09 sctp: pass a kernel pointer to sctp_setsockopt_pr_supported
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:43 -07:00
Christoph Hellwig
cfa6fde266 sctp: pass a kernel pointer to sctp_setsockopt_recvnxtinfo
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:43 -07:00
Christoph Hellwig
a98af7c84a sctp: pass a kernel pointer to sctp_setsockopt_recvrcvinfo
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:43 -07:00
Christoph Hellwig
b0ac3bb894 sctp: pass a kernel pointer to sctp_setsockopt_paddr_thresholds
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:43 -07:00
Christoph Hellwig
c9abc2c1c2 sctp: pass a kernel pointer to sctp_setsockopt_auto_asconf
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:43 -07:00
Christoph Hellwig
76b3d0c445 sctp: pass a kernel pointer to sctp_setsockopt_deactivate_key
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:43 -07:00
Christoph Hellwig
97dc9f2e3e sctp: pass a kernel pointer to sctp_setsockopt_del_key
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:43 -07:00
Christoph Hellwig
dcab0a7a57 sctp: pass a kernel pointer to sctp_setsockopt_active_key
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:43 -07:00
Christoph Hellwig
534d13d07e sctp: pass a kernel pointer to sctp_setsockopt_auth_key
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.  Adapt sctp_setsockopt to use a
kzfree for this case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
89fae01eef sctp: switch sctp_setsockopt_auth_key to use memzero_explicit
Switch from kzfree to sctp_setsockopt_auth_key + kfree to prepare for
moving the kfree to common code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
3564ef442a sctp: pass a kernel pointer to sctp_setsockopt_hmac_ident
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
88266d31b8 sctp: pass a kernel pointer to sctp_setsockopt_auth_chunk
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
f5bee0adb1 sctp: pass a kernel pointer to sctp_setsockopt_maxburst
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
1031cea001 sctp: pass a kernel pointer to sctp_setsockopt_fragment_interleave
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
722eca9eca sctp: pass a kernel pointer to sctp_setsockopt_context
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
07e5035c6f sctp: pass a kernel pointer to sctp_setsockopt_adaptation_layer
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
dcd0357580 sctp: pass a kernel pointer to sctp_setsockopt_maxseg
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
ffc08f086a sctp: pass a kernel pointer to sctp_setsockopt_mappedv4
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
5b864c8dab sctp: pass a kernel pointer to sctp_setsockopt_associnfo
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
af5ae60e42 sctp: pass a kernel pointer to sctp_setsockopt_rtoinfo
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
f87ddbc0c0 sctp: pass a kernel pointer to sctp_setsockopt_nodelay
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
46a0ae9de3 sctp: pass a kernel pointer to sctp_setsockopt_peer_primary_addr
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
1eec695804 sctp: pass a kernel pointer to sctp_setsockopt_primary_addr
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
8a2409d356 sctp: pass a kernel pointer to sctp_setsockopt_default_sndinfo
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
c23ad6d2b7 sctp: pass a kernel pointer to sctp_setsockopt_default_send_param
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:42 -07:00
Christoph Hellwig
9dfa6f0494 sctp: pass a kernel pointer to sctp_setsockopt_initmsg
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:41 -07:00
Christoph Hellwig
bb13d647d9 sctp: pass a kernel pointer to sctp_setsockopt_partial_delivery_point
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:41 -07:00
Christoph Hellwig
ebb25defdc sctp: pass a kernel pointer to sctp_setsockopt_delayed_ack
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:41 -07:00
Christoph Hellwig
9b7b0d1a39 sctp: pass a kernel pointer to sctp_setsockopt_peer_addr_params
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:41 -07:00
Christoph Hellwig
0b49a65c77 sctp: pass a kernel pointer to sctp_setsockopt_autoclose
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:41 -07:00
Christoph Hellwig
a98d21a173 sctp: pass a kernel pointer to sctp_setsockopt_events
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:41 -07:00
Christoph Hellwig
1083582558 sctp: pass a kernel pointer to sctp_setsockopt_disable_fragments
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:41 -07:00
Christoph Hellwig
ce5b2f8929 sctp: pass a kernel pointer to __sctp_setsockopt_connectx
Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:41 -07:00
Christoph Hellwig
8c7517f54c sctp: pass a kernel pointer to sctp_setsockopt_bindx
Rename sctp_setsockopt_bindx_kernel back to sctp_setsockopt_bindx,
and use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer in the old sctp_setsockopt_bindx.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:41 -07:00
Christoph Hellwig
ca84bd058d sctp: copy the optval from user space in sctp_setsockopt
Prepare for for moving the copy_from_user from the individual sockopts
to the main setsockopt helper.  As of this commit the kopt variable
is not used yet, but the following commits will start using it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:26:41 -07:00
Christoph Hellwig
c0425a4249 net: add a new bind_add method
The SCTP protocol allows to bind multiple address to a socket.  That
feature is currently only exposed as a socket option.  Add a bind_add
method struct proto that allows to bind additional addresses, and
switch the dlm code to use the method instead of going through the
socket option from kernel space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-29 13:10:39 -07:00
Christoph Hellwig
05bfd36614 sctp: refactor sctp_setsockopt_bindx
Split out a sctp_setsockopt_bindx_kernel that takes a kernel pointer
to the sockaddr and make sctp_setsockopt_bindx a small wrapper around
it.  This prepares for adding a new bind_add proto op.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-29 13:10:39 -07:00
David S. Miller
5a470b1a63 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-30 20:48:43 -07:00
Qiujun Huang
5c3e82fe15 sctp: fix refcount bug in sctp_wfree
We should iterate over the datamsgs to move
all chunks(skbs) to newsk.

The following case cause the bug:
for the trouble SKB, it was in outq->transmitted list

sctp_outq_sack
        sctp_check_transmitted
                SKB was moved to outq->sacked list
        then throw away the sack queue
                SKB was deleted from outq->sacked
(but it was held by datamsg at sctp_datamsg_to_asoc
So, sctp_wfree was not called here)

then migrate happened

        sctp_for_each_tx_datachunk(
        sctp_clear_owner_w);
        sctp_assoc_migrate();
        sctp_for_each_tx_datachunk(
        sctp_set_owner_w);
SKB was not in the outq, and was not changed to newsk

finally

__sctp_outq_teardown
        sctp_chunk_put (for another skb)
                sctp_datamsg_put
                        __kfree_skb(msg->frag_list)
                                sctp_wfree (for SKB)
	SKB->sk was still oldsk (skb->sk != asoc->base.sk).

Reported-and-tested-by: syzbot+cea71eec5d6de256d54d@syzkaller.appspotmail.com
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Acked-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 21:57:30 -07:00
Jules Irenge
b77b4f634e sctp: Add missing annotation for sctp_transport_walk_stop()
Sparse reports a warning at sctp_transport_walk_stop()

warning: context imbalance in sctp_transport_walk_stop
	- wrong count at exit

The root cause is the missing annotation at sctp_transport_walk_stop()
Add the missing __releases(RCU) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-24 13:26:49 -08:00
Jules Irenge
6c72b7740c sctp: Add missing annotation for sctp_transport_walk_start()
Sparse reports a warning at sctp_transport_walk_start()

warning: context imbalance in sctp_transport_walk_start
	- wrong count at exit

The root cause is the missing annotation at sctp_transport_walk_start()
Add the missing __acquires(RCU) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-24 13:26:48 -08:00
Xin Long
4e7696d90b sctp: get netns from asoc and ep base
Commit 312434617c ("sctp: cache netns in sctp_ep_common") set netns
in asoc and ep base since they're created, and it will never change.
It's a better way to get netns from asoc and ep base, comparing to
calling sock_net().

This patch is to replace them.

v1->v2:
  - no change.

Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-09 20:14:01 -08:00
Maciej Żenczykowski
82f31ebf61 net: port < inet_prot_sock(net) --> inet_port_requires_bind_service(net, port)
Note that the sysctl write accessor functions guarantee that:
  net->ipv4.sysctl_ip_prot_sock <= net->ipv4.ip_local_ports.range[0]
invariant is maintained, and as such the max() in selinux hooks is actually spurious.

ie. even though
  if (snum < max(inet_prot_sock(sock_net(sk)), low) || snum > high) {
per logic is the same as
  if ((snum < inet_prot_sock(sock_net(sk)) && snum < low) || snum > high) {
it is actually functionally equivalent to:
  if (snum < low || snum > high) {
which is equivalent to:
  if (snum < inet_prot_sock(sock_net(sk)) || snum < low || snum > high) {
even though the first clause is spurious.

But we want to hold on to it in case we ever want to change what what
inet_port_requires_bind_service() means (for example by changing
it from a, by default, [0..1024) range to some sort of set).

Test: builds, git 'grep inet_prot_sock' finds no other references
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-26 13:20:46 -08:00
Maciej Żenczykowski
fb8223888e net-sctp: replace some sock_net(sk) with just 'net'
It already existed in part of the function, but move it
to a higher level and use it consistently throughout.

Safe since sk is never written to.

Signed-off-by: Maciej Żenczykowski <maze@google.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-26 13:18:32 -08:00
Xin Long
d467ac0a38 sctp: add SCTP_PEER_ADDR_THLDS_V2 sockopt
Section 7.2 of rfc7829: "Peer Address Thresholds (SCTP_PEER_ADDR_THLDS)
Socket Option" extends 'struct sctp_paddrthlds' with 'spt_pathcpthld'
added to allow a user to change ps_retrans per sock/asoc/transport, as
other 2 paddrthlds: pf_retrans, pathmaxrxt.

Note: to not break the user's program, here to support pf_retrans dump
and setting by adding a new sockopt SCTP_PEER_ADDR_THLDS_V2, and a new
structure sctp_paddrthlds_v2 instead of extending sctp_paddrthlds.

Also, when setting ps_retrans, the value is not allowed to be greater
than pf_retrans.

v1->v2:
  - use SCTP_PEER_ADDR_THLDS_V2 to set/get pf_retrans instead,
    as Marcelo and David Laight suggested.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-08 14:18:32 -08:00
Xin Long
34515e94c9 sctp: add support for Primary Path Switchover
This is a new feature defined in section 5 of rfc7829: "Primary Path
Switchover". By introducing a new tunable parameter:

  Primary.Switchover.Max.Retrans (PSMR)

The primary path will be changed to another active path when the path
error counter on the old primary path exceeds PSMR, so that "the SCTP
sender is allowed to continue data transmission on a new working path
even when the old primary destination address becomes active again".

This patch is to add this tunable parameter, 'ps_retrans' per netns,
sock, asoc and transport. It also allows a user to change ps_retrans
per netns by sysctl, and ps_retrans per sock/asoc/transport will be
initialized with it.

The check will be done in sctp_do_8_2_transport_strike() when this
feature is enabled.

Note this feature is disabled by initializing 'ps_retrans' per netns
as 0xffff by default, and its value can't be less than 'pf_retrans'
when changing by sysctl.

v3->v4:
  - add define SCTP_PS_RETRANS_MAX 0xffff, and use it on extra2 of
    sysctl 'ps_retrans'.
  - add a new entry for ps_retrans on ip-sysctl.txt.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-08 14:18:32 -08:00
Xin Long
8d2a6935d8 sctp: add SCTP_EXPOSE_POTENTIALLY_FAILED_STATE sockopt
This is a sockopt defined in section 7.3 of rfc7829: "Exposing
the Potentially Failed Path State", by which users can change
pf_expose per sock and asoc.

The new sockopt SCTP_EXPOSE_POTENTIALLY_FAILED_STATE is also
known as SCTP_EXPOSE_PF_STATE for short.

v2->v3:
  - return -EINVAL if params.assoc_value > SCTP_PF_EXPOSE_MAX.
  - define SCTP_EXPOSE_PF_STATE SCTP_EXPOSE_POTENTIALLY_FAILED_STATE.
v3->v4:
  - improve changelog.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-08 14:18:32 -08:00
Xin Long
aef587be42 sctp: add pf_expose per netns and sock and asoc
As said in rfc7829, section 3, point 12:

  The SCTP stack SHOULD expose the PF state of its destination
  addresses to the ULP as well as provide the means to notify the
  ULP of state transitions of its destination addresses from
  active to PF, and vice versa.  However, it is recommended that
  an SCTP stack implementing SCTP-PF also allows for the ULP to be
  kept ignorant of the PF state of its destinations and the
  associated state transitions, thus allowing for retention of the
  simpler state transition model of [RFC4960] in the ULP.

Not only does it allow to expose the PF state to ULP, but also
allow to ignore sctp-pf to ULP.

So this patch is to add pf_expose per netns, sock and asoc. And in
sctp_assoc_control_transport(), ulp_notify will be set to false if
asoc->expose is not 'enabled' in next patch.

It also allows a user to change pf_expose per netns by sysctl, and
pf_expose per sock and asoc will be initialized with it.

Note that pf_expose also works for SCTP_GET_PEER_ADDR_INFO sockopt,
to not allow a user to query the state of a sctp-pf peer address
when pf_expose is 'disabled', as said in section 7.3.

v1->v2:
  - Fix a build warning noticed by Nathan Chancellor.
v2->v3:
  - set pf_expose to UNUSED by default to keep compatible with old
    applications.
v3->v4:
  - add a new entry for pf_expose on ip-sysctl.txt, as Marcelo suggested.
  - change this patch to 1/5, and move sctp_assoc_control_transport
    change into 2/5, as Marcelo suggested.
  - use SCTP_PF_EXPOSE_UNSET instead of SCTP_PF_EXPOSE_UNUSED, and
    set SCTP_PF_EXPOSE_UNSET to 0 in enum, as Marcelo suggested.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-08 14:18:32 -08:00