From 3ff547c06a7d75d72d37dae2c064fcf0672e56c0 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Wed, 14 Mar 2018 19:05:31 +0800 Subject: [PATCH] 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 Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- 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 49ad67bbdbb5..012fb3e2f4cf 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 e94b6d297ad9..47e781ebde05 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 9f28a9aae976..f889a84f264d 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 003a4ad89c01..9ffdecbc3531 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 -- 2.45.2