From 0d3a421d284812d07970b4ccee74d4fa38737e4d Mon Sep 17 00:00:00 2001 From: Geir Ola Vaagland Date: Sat, 12 Jul 2014 20:30:37 +0200 Subject: net: sctp: implement rfc6458, 5.3.5. SCTP_RCVINFO cmsg support This patch implements section 5.3.5. of RFC6458, that is, support for 'SCTP Receive Information Structure' (SCTP_RCVINFO) which is placed into ancillary data cmsghdr structure for each recvmsg() call. This option can be enabled/disabled via setsockopt(2) on SOL_SCTP level by setting an int value with 1/0 for SCTP_RECVRCVINFO in user space applications as per RFC6458, section 8.1.29. The sctp_rcvinfo structure is defined as per RFC as below ... struct sctp_rcvinfo { uint16_t rcv_sid; uint16_t rcv_ssn; uint16_t rcv_flags; <-- 2 bytes hole --> uint32_t rcv_ppid; uint32_t rcv_tsn; uint32_t rcv_cumtsn; uint32_t rcv_context; sctp_assoc_t rcv_assoc_id; }; ... and provided under cmsg_level IPPROTO_SCTP, cmsg_type SCTP_RCVINFO, while cmsg_data[] contains struct sctp_rcvinfo. An sctp_rcvinfo item always corresponds to the data in msg_iov. Joint work with Daniel Borkmann. Signed-off-by: Geir Ola Vaagland Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller --- net/sctp/ulpevent.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'net/sctp/ulpevent.c') diff --git a/net/sctp/ulpevent.c b/net/sctp/ulpevent.c index b6842fdb53d4..b31f365f18ab 100644 --- a/net/sctp/ulpevent.c +++ b/net/sctp/ulpevent.c @@ -886,6 +886,31 @@ void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event, sizeof(sinfo), &sinfo); } +/* RFC6458, Section 5.3.5 SCTP Receive Information Structure + * (SCTP_SNDRCV) + */ +void sctp_ulpevent_read_rcvinfo(const struct sctp_ulpevent *event, + struct msghdr *msghdr) +{ + struct sctp_rcvinfo rinfo; + + if (sctp_ulpevent_is_notification(event)) + return; + + memset(&rinfo, 0, sizeof(struct sctp_rcvinfo)); + rinfo.rcv_sid = event->stream; + rinfo.rcv_ssn = event->ssn; + rinfo.rcv_ppid = event->ppid; + rinfo.rcv_flags = event->flags; + rinfo.rcv_tsn = event->tsn; + rinfo.rcv_cumtsn = event->cumtsn; + rinfo.rcv_assoc_id = sctp_assoc2id(event->asoc); + rinfo.rcv_context = event->asoc->default_rcv_context; + + put_cmsg(msghdr, IPPROTO_SCTP, SCTP_RCVINFO, + sizeof(rinfo), &rinfo); +} + /* Do accounting for bytes received and hold a reference to the association * for each skb. */ -- cgit v1.2.3