sctp: add support for SCTP AUTH Information for sendmsg

This patch is to add support for SCTP AUTH Information for sendmsg,
as described in section 5.3.8 of RFC6458.

With this option, you can provide shared key identifier used for
sending the user message.

It's also a necessary send info for sctp_sendv.

Note that it reuses sinfo->sinfo_tsn to indicate if this option is
set and sinfo->sinfo_ssn to save the shkey ID which can be 0.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xin Long 2018-03-14 19:05:31 +08:00 committed by David S. Miller
parent 1b1e0bc994
commit 3ff547c06a
4 changed files with 47 additions and 2 deletions

View File

@ -2118,6 +2118,7 @@ struct sctp_cmsgs {
struct sctp_sndrcvinfo *srinfo;
struct sctp_sndinfo *sinfo;
struct sctp_prinfo *prinfo;
struct sctp_authinfo *authinfo;
struct msghdr *addrs_msg;
};

View File

@ -273,6 +273,18 @@ struct sctp_prinfo {
__u32 pr_value;
};
/* 5.3.8 SCTP AUTH Information Structure (SCTP_AUTHINFO)
*
* This cmsghdr structure specifies SCTP options for sendmsg().
*
* cmsg_level cmsg_type cmsg_data[]
* ------------ ------------ -------------------
* IPPROTO_SCTP SCTP_AUTHINFO struct sctp_authinfo
*/
struct sctp_authinfo {
__u16 auth_keynumber;
};
/*
* sinfo_flags: 16 bits (unsigned integer)
*
@ -310,7 +322,7 @@ typedef enum sctp_cmsg_type {
#define SCTP_NXTINFO SCTP_NXTINFO
SCTP_PRINFO, /* 5.3.7 SCTP PR-SCTP Information Structure */
#define SCTP_PRINFO SCTP_PRINFO
SCTP_AUTHINFO, /* 5.3.8 SCTP AUTH Information Structure (RESERVED) */
SCTP_AUTHINFO, /* 5.3.8 SCTP AUTH Information Structure */
#define SCTP_AUTHINFO SCTP_AUTHINFO
SCTP_DSTADDRV4, /* 5.3.9 SCTP Destination IPv4 Address Structure */
#define SCTP_DSTADDRV4 SCTP_DSTADDRV4

View File

@ -206,8 +206,17 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
max_data -= SCTP_PAD4(sizeof(struct sctp_auth_chunk) +
hmac_desc->hmac_len);
if (sinfo->sinfo_tsn &&
sinfo->sinfo_ssn != asoc->active_key_id) {
shkey = sctp_auth_get_shkey(asoc, sinfo->sinfo_ssn);
if (!shkey) {
err = -EINVAL;
goto errout;
}
} else {
shkey = asoc->shkey;
}
}
/* Check what's our max considering the above */
max_data = min_t(size_t, max_data, asoc->frag_point);

View File

@ -1987,6 +1987,14 @@ static void sctp_sendmsg_update_sinfo(struct sctp_association *asoc,
if (!cmsgs->srinfo && !cmsgs->prinfo)
sinfo->sinfo_timetolive = asoc->default_timetolive;
if (cmsgs->authinfo) {
/* Reuse sinfo_tsn to indicate that authinfo was set and
* sinfo_ssn to save the keyid on tx path.
*/
sinfo->sinfo_tsn = 1;
sinfo->sinfo_ssn = cmsgs->authinfo->auth_keynumber;
}
}
static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
@ -7874,6 +7882,21 @@ static int sctp_msghdr_parse(const struct msghdr *msg, struct sctp_cmsgs *cmsgs)
if (cmsgs->prinfo->pr_policy == SCTP_PR_SCTP_NONE)
cmsgs->prinfo->pr_value = 0;
break;
case SCTP_AUTHINFO:
/* SCTP Socket API Extension
* 5.3.8 SCTP AUTH Information Structure (SCTP_AUTHINFO)
*
* This cmsghdr structure specifies SCTP options for sendmsg().
*
* cmsg_level cmsg_type cmsg_data[]
* ------------ ------------ ---------------------
* IPPROTO_SCTP SCTP_AUTHINFO struct sctp_authinfo
*/
if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct sctp_authinfo)))
return -EINVAL;
cmsgs->authinfo = CMSG_DATA(cmsg);
break;
case SCTP_DSTADDRV4:
case SCTP_DSTADDRV6:
/* SCTP Socket API Extension