linux/include/net/sctp
Xin Long a1dd2cf2f1 sctp: allow changing transport encap_port by peer packets
As rfc6951#section-5.4 says:

  "After finding the SCTP association (which
   includes checking the verification tag), the UDP source port MUST be
   stored as the encapsulation port for the destination address the SCTP
   packet is received from (see Section 5.1).

   When a non-encapsulated SCTP packet is received by the SCTP stack,
   the encapsulation of outgoing packets belonging to the same
   association and the corresponding destination address MUST be
   disabled."

transport encap_port should be updated by a validated incoming packet's
udp src port.

We save the udp src port in sctp_input_cb->encap_port, and then update
the transport in two places:

  1. right after vtag is verified, which is required by RFC, and this
     allows the existent transports to be updated by the chunks that
     can only be processed on an asoc.

  2. right before processing the 'init' where the transports are added,
     and this allows building a sctp over udp connection by client with
     the server not knowing the remote encap port.

  3. when processing ootb_pkt and creating the temporary transport for
     the reply pkt.

Note that sctp_input_cb->header is removed, as it's not used any more
in sctp.

v1->v2:
  - Change encap_port as __be16 for sctp_input_cb.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-30 15:24:16 -07:00
..
auth.h sctp: add sctp_auth_init and sctp_auth_free 2019-08-19 18:27:29 -07:00
checksum.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-31 10:49:43 -07:00
command.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
constants.h sctp: create udp4 sock and add its encap_rcv 2020-10-30 15:23:52 -07:00
sctp.h sctp: create udp4 sock and add its encap_rcv 2020-10-30 15:23:52 -07:00
sm.h sctp: allow changing transport encap_port by peer packets 2020-10-30 15:24:16 -07:00
stream_interleave.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
stream_sched.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
structs.h sctp: allow changing transport encap_port by peer packets 2020-10-30 15:24:16 -07:00
tsnmap.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00
ulpevent.h sctp: fix typo sctp_ulpevent_nofity_peer_addr_change 2020-05-27 15:08:02 -07:00
ulpqueue.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104 2019-05-24 17:39:00 +02:00