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/socket.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++- net/sctp/ulpevent.c | 25 +++++++++++++++++++++++++ 2 files changed, 73 insertions(+), 1 deletion(-) (limited to 'net/sctp') diff --git a/net/sctp/socket.c b/net/sctp/socket.c index d61729e99856..9c193887c5cd 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -2112,9 +2112,13 @@ static int sctp_recvmsg(struct kiocb *iocb, struct sock *sk, sp->pf->skb_msgname(skb, msg->msg_name, addr_len); } + /* Check if we allow SCTP_RCVINFO. */ + if (sp->recvrcvinfo) + sctp_ulpevent_read_rcvinfo(event, msg); /* Check if we allow SCTP_SNDRCVINFO. */ if (sp->subscribe.sctp_data_io_event) sctp_ulpevent_read_sndrcvinfo(event, msg); + #if 0 /* FIXME: we should be calling IP/IPv6 layers. */ if (sk->sk_protinfo.af_inet.cmsg_flags) @@ -3541,7 +3545,6 @@ static int sctp_setsockopt_auto_asconf(struct sock *sk, char __user *optval, return 0; } - /* * SCTP_PEER_ADDR_THLDS * @@ -3592,6 +3595,22 @@ static int sctp_setsockopt_paddr_thresholds(struct sock *sk, return 0; } +static int sctp_setsockopt_recvrcvinfo(struct sock *sk, + char __user *optval, + unsigned int optlen) +{ + int val; + + if (optlen < sizeof(int)) + return -EINVAL; + if (get_user(val, (int __user *) optval)) + return -EFAULT; + + sctp_sk(sk)->recvrcvinfo = (val == 0) ? 0 : 1; + + return 0; +} + /* API 6.2 setsockopt(), getsockopt() * * Applications use setsockopt() and getsockopt() to set or retrieve @@ -3743,6 +3762,9 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname, case SCTP_PEER_ADDR_THLDS: retval = sctp_setsockopt_paddr_thresholds(sk, optval, optlen); break; + case SCTP_RECVRCVINFO: + retval = sctp_setsockopt_recvrcvinfo(sk, optval, optlen); + break; default: retval = -ENOPROTOOPT; break; @@ -3989,6 +4011,8 @@ static int sctp_init_sock(struct sock *sk) /* Enable Nagle algorithm by default. */ sp->nodelay = 0; + sp->recvrcvinfo = 0; + /* Enable by default. */ sp->v4mapped = 1; @@ -5770,6 +5794,26 @@ static int sctp_getsockopt_assoc_stats(struct sock *sk, int len, return 0; } +static int sctp_getsockopt_recvrcvinfo(struct sock *sk, int len, + char __user *optval, + int __user *optlen) +{ + int val = 0; + + if (len < sizeof(int)) + return -EINVAL; + + len = sizeof(int); + if (sctp_sk(sk)->recvrcvinfo) + val = 1; + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, &val, len)) + return -EFAULT; + + return 0; +} + static int sctp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen) { @@ -5913,6 +5957,9 @@ static int sctp_getsockopt(struct sock *sk, int level, int optname, case SCTP_GET_ASSOC_STATS: retval = sctp_getsockopt_assoc_stats(sk, len, optval, optlen); break; + case SCTP_RECVRCVINFO: + retval = sctp_getsockopt_recvrcvinfo(sk, len, optval, optlen); + break; default: retval = -ENOPROTOOPT; break; 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