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| author | Geir Ola Vaagland <geirola@gmail.com> | 2014-07-12 22:30:38 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-07-17 01:40:03 +0400 |
| commit | 2347c80ff127b94ddaa675e2b78ab4cef46dc905 (patch) | |
| tree | 5fe57c8b7814f629cb773bbea0c1a9f8eba035d0 /net/sctp/ulpevent.c | |
| parent | 0d3a421d284812d07970b4ccee74d4fa38737e4d (diff) | |
| download | linux-2347c80ff127b94ddaa675e2b78ab4cef46dc905.tar.xz | |
net: sctp: implement rfc6458, 5.3.6. SCTP_NXTINFO cmsg support
This patch implements section 5.3.6. of RFC6458, that is, support
for 'SCTP Next Receive Information Structure' (SCTP_NXTINFO) which
is placed into ancillary data cmsghdr structure for each recvmsg()
call, if this information is already available when delivering the
current message.
This option can be enabled/disabled via setsockopt(2) on SOL_SCTP
level by setting an int value with 1/0 for SCTP_RECVNXTINFO in
user space applications as per RFC6458, section 8.1.30.
The sctp_nxtinfo structure is defined as per RFC as below ...
struct sctp_nxtinfo {
uint16_t nxt_sid;
uint16_t nxt_flags;
uint32_t nxt_ppid;
uint32_t nxt_length;
sctp_assoc_t nxt_assoc_id;
};
... and provided under cmsg_level IPPROTO_SCTP, cmsg_type
SCTP_NXTINFO, while cmsg_data[] contains struct sctp_nxtinfo.
Joint work with Daniel Borkmann.
Signed-off-by: Geir Ola Vaagland <geirola@gmail.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sctp/ulpevent.c')
| -rw-r--r-- | net/sctp/ulpevent.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/net/sctp/ulpevent.c b/net/sctp/ulpevent.c index b31f365f18ab..e049298ecfa0 100644 --- a/net/sctp/ulpevent.c +++ b/net/sctp/ulpevent.c @@ -911,6 +911,44 @@ void sctp_ulpevent_read_rcvinfo(const struct sctp_ulpevent *event, sizeof(rinfo), &rinfo); } +/* RFC6458, Section 5.3.6. SCTP Next Receive Information Structure + * (SCTP_NXTINFO) + */ +static void __sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event, + struct msghdr *msghdr, + const struct sk_buff *skb) +{ + struct sctp_nxtinfo nxtinfo; + + memset(&nxtinfo, 0, sizeof(nxtinfo)); + nxtinfo.nxt_sid = event->stream; + nxtinfo.nxt_ppid = event->ppid; + nxtinfo.nxt_flags = event->flags; + if (sctp_ulpevent_is_notification(event)) + nxtinfo.nxt_flags |= SCTP_NOTIFICATION; + nxtinfo.nxt_length = skb->len; + nxtinfo.nxt_assoc_id = sctp_assoc2id(event->asoc); + + put_cmsg(msghdr, IPPROTO_SCTP, SCTP_NXTINFO, + sizeof(nxtinfo), &nxtinfo); +} + +void sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event, + struct msghdr *msghdr, + struct sock *sk) +{ + struct sk_buff *skb; + int err; + + skb = sctp_skb_recv_datagram(sk, MSG_PEEK, 1, &err); + if (skb != NULL) { + __sctp_ulpevent_read_nxtinfo(sctp_skb2event(skb), + msghdr, skb); + /* Just release refcount here. */ + kfree_skb(skb); + } +} + /* Do accounting for bytes received and hold a reference to the association * for each skb. */ |