On Wed, Mar 14, 2018 at 07:05:31PM +0800, Xin Long wrote:
> 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....@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leit...@gmail.com>
> ---
> include/net/sctp/structs.h | 1 +
> include/uapi/linux/sctp.h | 14 +++++++++++++-
> net/sctp/chunk.c | 11 ++++++++++-
> net/sctp/socket.c | 23 +++++++++++++++++++++++
> 4 files changed, 47 insertions(+), 2 deletions(-)
>
> diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
> index 49ad67b..012fb3e 100644
> --- a/include/net/sctp/structs.h
> +++ b/include/net/sctp/structs.h
> @@ -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;
> };
>
> diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
> index e94b6d2..47e781e 100644
> --- a/include/uapi/linux/sctp.h
> +++ b/include/uapi/linux/sctp.h
> @@ -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
> diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
> index 9f28a9a..f889a84 100644
> --- a/net/sctp/chunk.c
> +++ b/net/sctp/chunk.c
> @@ -206,7 +206,16 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct
> sctp_association *asoc,
> max_data -= SCTP_PAD4(sizeof(struct sctp_auth_chunk) +
> hmac_desc->hmac_len);
>
> - shkey = asoc->shkey;
> + 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 */
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index 003a4ad..9ffdecb 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -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
> --
> 2.1.0
>
