net: sctp: implement rfc6458, 5.3.4. SCTP_SNDINFO cmsg support

This patch implements section 5.3.4. of RFC6458, that is, support
for 'SCTP Send Information Structure' (SCTP_SNDINFO) which can be
placed into ancillary data cmsghdr structure for sendmsg() calls.

The sctp_sndinfo structure is defined as per RFC as below ...

  struct sctp_sndinfo {
    uint16_t snd_sid;
    uint16_t snd_flags;
    uint32_t snd_ppid;
    uint32_t snd_context;
    sctp_assoc_t snd_assoc_id;
  };

... and supplied under cmsg_level IPPROTO_SCTP, cmsg_type
SCTP_SNDINFO, while cmsg_data[] contains struct sctp_sndinfo.
An sctp_sndinfo item always corresponds to the data in msg_iov.

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>
This commit is contained in:
Geir Ola Vaagland
2014-07-12 20:30:36 +02:00
committed by David S. Miller
parent 1a98c69af1
commit 63b949382c
3 changed files with 79 additions and 23 deletions

View File

@@ -154,6 +154,22 @@ struct sctp_sndrcvinfo {
sctp_assoc_t sinfo_assoc_id;
};
/* 5.3.4 SCTP Send Information Structure (SCTP_SNDINFO)
*
* This cmsghdr structure specifies SCTP options for sendmsg().
*
* cmsg_level cmsg_type cmsg_data[]
* ------------ ------------ -------------------
* IPPROTO_SCTP SCTP_SNDINFO struct sctp_sndinfo
*/
struct sctp_sndinfo {
__u16 snd_sid;
__u16 snd_flags;
__u32 snd_ppid;
__u32 snd_context;
sctp_assoc_t snd_assoc_id;
};
/*
* sinfo_flags: 16 bits (unsigned integer)
*
@@ -177,10 +193,12 @@ typedef union {
/* These are cmsg_types. */
typedef enum sctp_cmsg_type {
SCTP_INIT, /* 5.2.1 SCTP Initiation Structure */
SCTP_INIT, /* 5.2.1 SCTP Initiation Structure */
#define SCTP_INIT SCTP_INIT
SCTP_SNDRCV, /* 5.2.2 SCTP Header Information Structure */
SCTP_SNDRCV, /* 5.2.2 SCTP Header Information Structure */
#define SCTP_SNDRCV SCTP_SNDRCV
SCTP_SNDINFO, /* 5.3.4 SCTP Send Information Structure */
#define SCTP_SNDINFO SCTP_SNDINFO
} sctp_cmsg_t;
/*