From aef587be42925f92418083f08852d0011b2766ca Mon Sep 17 00:00:00 2001 From: Xin Long Date: Fri, 8 Nov 2019 13:20:32 +0800 Subject: 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 Acked-by: Neil Horman Signed-off-by: David S. Miller --- net/sctp/protocol.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'net/sctp/protocol.c') diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c index 08d14d86ecfb..f86be7bf0972 100644 --- a/net/sctp/protocol.c +++ b/net/sctp/protocol.c @@ -1220,6 +1220,9 @@ static int __net_init sctp_defaults_init(struct net *net) /* Enable pf state by default */ net->sctp.pf_enable = 1; + /* Ignore pf exposure feature by default */ + net->sctp.pf_expose = SCTP_PF_EXPOSE_UNSET; + /* Association.Max.Retrans - 10 attempts * Path.Max.Retrans - 5 attempts (per destination address) * Max.Init.Retransmits - 8 attempts -- cgit v1.2.3-58-ga151