On Mon, Mar 05, 2018 at 08:44:18PM +0800, Xin Long wrote:
> This patch is to add support for PR-SCTP Information for sendmsg,
> as described in section 5.3.7 of RFC6458.
>
> With this option, you can specify pr_policy and pr_value for user
> data in sendmsg.
>
> It's also a necessary send info for sctp_sendv.
>
> 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 | 15 +++++++++++++++
> net/sctp/socket.c | 31 ++++++++++++++++++++++++++++++-
> 3 files changed, 46 insertions(+), 1 deletion(-)
>
> diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
> index 03e92dd..d40a2a3 100644
> --- a/include/net/sctp/structs.h
> +++ b/include/net/sctp/structs.h
> @@ -2112,6 +2112,7 @@ struct sctp_cmsgs {
> struct sctp_initmsg *init;
> struct sctp_sndrcvinfo *srinfo;
> struct sctp_sndinfo *sinfo;
> + struct sctp_prinfo *prinfo;
> };
>
> /* Structure for tracking memory objects */
> diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
> index 4c4db14..0dd1f82 100644
> --- a/include/uapi/linux/sctp.h
> +++ b/include/uapi/linux/sctp.h
> @@ -260,6 +260,19 @@ struct sctp_nxtinfo {
> sctp_assoc_t nxt_assoc_id;
> };
>
> +/* 5.3.7 SCTP PR-SCTP Information Structure (SCTP_PRINFO)
> + *
> + * This cmsghdr structure specifies SCTP options for sendmsg().
> + *
> + * cmsg_level cmsg_type cmsg_data[]
> + * ------------ ------------ -------------------
> + * IPPROTO_SCTP SCTP_PRINFO struct sctp_prinfo
> + */
> +struct sctp_prinfo {
> + __u16 pr_policy;
> + __u32 pr_value;
> +};
> +
> /*
> * sinfo_flags: 16 bits (unsigned integer)
> *
> @@ -293,6 +306,8 @@ typedef enum sctp_cmsg_type {
> #define SCTP_RCVINFO SCTP_RCVINFO
> SCTP_NXTINFO, /* 5.3.6 SCTP Next Receive Information
> Structure */
> #define SCTP_NXTINFO SCTP_NXTINFO
> + SCTP_PRINFO, /* 5.3.7 SCTP PR-SCTP Information Structure */
> +#define SCTP_PRINFO SCTP_PRINFO
> } sctp_cmsg_t;
>
> /*
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index 7fa7603..fdde697 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -1644,6 +1644,12 @@ static int sctp_sendmsg_parse(struct sock *sk, struct
> sctp_cmsgs *cmsgs,
> srinfo->sinfo_assoc_id = cmsgs->sinfo->snd_assoc_id;
> }
>
> + if (cmsgs->prinfo) {
> + srinfo->sinfo_timetolive = cmsgs->prinfo->pr_value;
> + SCTP_PR_SET_POLICY(srinfo->sinfo_flags,
> + cmsgs->prinfo->pr_policy);
> + }
> +
> sflags = srinfo->sinfo_flags;
> if (!sflags && msg_len)
> return 0;
> @@ -1901,9 +1907,12 @@ static void sctp_sendmsg_update_sinfo(struct
> sctp_association *asoc,
> sinfo->sinfo_ppid = asoc->default_ppid;
> sinfo->sinfo_context = asoc->default_context;
> sinfo->sinfo_assoc_id = sctp_assoc2id(asoc);
> +
> + if (!cmsgs->prinfo)
> + sinfo->sinfo_flags = asoc->default_flags;
> }
>
> - if (!cmsgs->srinfo)
> + if (!cmsgs->srinfo && !cmsgs->prinfo)
> sinfo->sinfo_timetolive = asoc->default_timetolive;
> }
>
> @@ -7749,6 +7758,26 @@ static int sctp_msghdr_parse(const struct msghdr *msg,
> struct sctp_cmsgs *cmsgs)
> SCTP_ABORT | SCTP_EOF))
> return -EINVAL;
> break;
> + case SCTP_PRINFO:
> + /* SCTP Socket API Extension
> + * 5.3.7 SCTP PR-SCTP Information Structure
> (SCTP_PRINFO)
> + *
> + * This cmsghdr structure specifies SCTP options for
> sendmsg().
> + *
> + * cmsg_level cmsg_type cmsg_data[]
> + * ------------ ------------ ---------------------
> + * IPPROTO_SCTP SCTP_PRINFO struct sctp_prinfo
> + */
> + if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct
> sctp_prinfo)))
> + return -EINVAL;
> +
> + cmsgs->prinfo = CMSG_DATA(cmsg);
> + if (cmsgs->prinfo->pr_policy & ~SCTP_PR_SCTP_MASK)
> + return -EINVAL;
> +
> + if (cmsgs->prinfo->pr_policy == SCTP_PR_SCTP_NONE)
> + cmsgs->prinfo->pr_value = 0;
> + break;
> default:
> return -EINVAL;
> }
> --
> 2.1.0
>
