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Commit 0d3a421d authored by Geir Ola Vaagland's avatar Geir Ola Vaagland Committed by David S. Miller
Browse files

net: sctp: implement rfc6458, 5.3.5. SCTP_RCVINFO cmsg support 



This patch implements section 5.3.5. of RFC6458, that is, support
for 'SCTP Receive Information Structure' (SCTP_RCVINFO) which is
placed into ancillary data cmsghdr structure for each recvmsg()
call.

This option can be enabled/disabled via setsockopt(2) on SOL_SCTP
level by setting an int value with 1/0 for SCTP_RECVRCVINFO in user
space applications as per RFC6458, section 8.1.29.

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

  struct sctp_rcvinfo {
    uint16_t rcv_sid;
    uint16_t rcv_ssn;
    uint16_t rcv_flags;
    <-- 2 bytes hole  -->
    uint32_t rcv_ppid;
    uint32_t rcv_tsn;
    uint32_t rcv_cumtsn;
    uint32_t rcv_context;
    sctp_assoc_t rcv_assoc_id;
  };

... and provided under cmsg_level IPPROTO_SCTP, cmsg_type
SCTP_RCVINFO, while cmsg_data[] contains struct sctp_rcvinfo.
An sctp_rcvinfo item always corresponds to the data in msg_iov.

Joint work with Daniel Borkmann.

Signed-off-by: default avatarGeir Ola Vaagland <geirola@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 63b94938

include/net/sctp/structs.h

+3 −0
Original line number Diff line number Diff line
@@ -207,7 +207,9 @@ struct sctp_sock { 
	struct sctp_paddrparams paddrparam;

	struct sctp_event_subscribe subscribe;

	struct sctp_assocparams assocparams;



	int user_frag;



	__u32 autoclose;

	__u8 nodelay;

	__u8 disable_fragments;
@@ -215,6 +217,7 @@ struct sctp_sock { 
	__u8 frag_interleave;

	__u32 adaptation_ind;

	__u32 pd_point;

	__u8 recvrcvinfo;



	atomic_t pd_mode;

	/* Receive to here while partial delivery is in effect. */

include/net/sctp/ulpevent.h

+4 −1
Original line number Diff line number Diff line
@@ -130,6 +130,9 @@ struct sctp_ulpevent *sctp_ulpevent_make_sender_dry_event( 


void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event,

				   struct msghdr *);

void sctp_ulpevent_read_rcvinfo(const struct sctp_ulpevent *event,

				struct msghdr *);



__u16 sctp_ulpevent_get_notification_type(const struct sctp_ulpevent *event);



/* Is this event type enabled? */

include/uapi/linux/sctp.h

+25 −7
Original line number Diff line number Diff line
@@ -95,6 +95,7 @@ typedef __s32 sctp_assoc_t; 
#define SCTP_GET_ASSOC_ID_LIST	29	/* Read only */

#define SCTP_AUTO_ASCONF       30

#define SCTP_PEER_ADDR_THLDS	31

#define SCTP_RECVRCVINFO	32



/* Internal Socket Options. Some of the sctp library functions are

 * implemented using these socket options.
@@ -110,8 +111,7 @@ typedef __s32 sctp_assoc_t; 
#define SCTP_SOCKOPT_CONNECTX3	111	/* CONNECTX requests (updated) */

#define SCTP_GET_ASSOC_STATS	112	/* Read only */



/*

 * 5.2.1 SCTP Initiation Structure (SCTP_INIT)

/* 5.3.1 SCTP Initiation Structure (SCTP_INIT)

 *

 *   This cmsghdr structure provides information for initializing new

 *   SCTP associations with sendmsg().  The SCTP_INITMSG socket option
@@ -121,7 +121,6 @@ typedef __s32 sctp_assoc_t; 
 *   cmsg_level    cmsg_type      cmsg_data[]

 *   ------------  ------------   ----------------------

 *   IPPROTO_SCTP  SCTP_INIT      struct sctp_initmsg

 *

 */

struct sctp_initmsg {

	__u16 sinit_num_ostreams;
@@ -130,8 +129,7 @@ struct sctp_initmsg { 
	__u16 sinit_max_init_timeo;

};



/*

 * 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)

/* 5.3.2 SCTP Header Information Structure (SCTP_SNDRCV)

 *

 *   This cmsghdr structure specifies SCTP options for sendmsg() and

 *   describes SCTP header information about a received message through
@@ -140,7 +138,6 @@ struct sctp_initmsg { 
 *   cmsg_level    cmsg_type      cmsg_data[]

 *   ------------  ------------   ----------------------

 *   IPPROTO_SCTP  SCTP_SNDRCV    struct sctp_sndrcvinfo

 *

 */

struct sctp_sndrcvinfo {

	__u16 sinfo_stream;
@@ -170,13 +167,32 @@ struct sctp_sndinfo { 
	sctp_assoc_t snd_assoc_id;

};



/* 5.3.5 SCTP Receive Information Structure (SCTP_RCVINFO)

 *

 *   This cmsghdr structure describes SCTP receive information

 *   about a received message through recvmsg().

 *

 *   cmsg_level    cmsg_type      cmsg_data[]

 *   ------------  ------------   -------------------

 *   IPPROTO_SCTP  SCTP_RCVINFO   struct sctp_rcvinfo

 */

struct sctp_rcvinfo {

	__u16 rcv_sid;

	__u16 rcv_ssn;

	__u16 rcv_flags;

	__u32 rcv_ppid;

	__u32 rcv_tsn;

	__u32 rcv_cumtsn;

	__u32 rcv_context;

	sctp_assoc_t rcv_assoc_id;

};



/*

 *  sinfo_flags: 16 bits (unsigned integer)

 *

 *   This field may contain any of the following flags and is composed of

 *   a bitwise OR of these values.

 */



enum sctp_sinfo_flags {

	SCTP_UNORDERED = 1,  /* Send/receive message unordered. */

	SCTP_ADDR_OVER = 2,  /* Override the primary destination. */
@@ -199,6 +215,8 @@ typedef enum sctp_cmsg_type { 
#define SCTP_SNDRCV	SCTP_SNDRCV

	SCTP_SNDINFO,		/* 5.3.4 SCTP Send Information Structure */

#define SCTP_SNDINFO	SCTP_SNDINFO

	SCTP_RCVINFO,		/* 5.3.5 SCTP Receive Information Structure */

#define SCTP_RCVINFO	SCTP_RCVINFO

} sctp_cmsg_t;



/*

net/sctp/socket.c

+48 −1
Original line number Diff line number Diff line
@@ -2112,9 +2112,13 @@ static int sctp_recvmsg(struct kiocb *iocb, struct sock *sk, 
		sp->pf->skb_msgname(skb, msg->msg_name, addr_len);

	}



	/* Check if we allow SCTP_RCVINFO. */

	if (sp->recvrcvinfo)

		sctp_ulpevent_read_rcvinfo(event, msg);

	/* Check if we allow SCTP_SNDRCVINFO. */

	if (sp->subscribe.sctp_data_io_event)

		sctp_ulpevent_read_sndrcvinfo(event, msg);



#if 0

	/* FIXME: we should be calling IP/IPv6 layers.  */

	if (sk->sk_protinfo.af_inet.cmsg_flags)
@@ -3541,7 +3545,6 @@ static int sctp_setsockopt_auto_asconf(struct sock *sk, char __user *optval, 
	return 0;

}





/*

 * SCTP_PEER_ADDR_THLDS

 *
@@ -3592,6 +3595,22 @@ static int sctp_setsockopt_paddr_thresholds(struct sock *sk, 
	return 0;

}



static int sctp_setsockopt_recvrcvinfo(struct sock *sk,

				       char __user *optval,

				       unsigned int optlen)

{

	int val;



	if (optlen < sizeof(int))

		return -EINVAL;

	if (get_user(val, (int __user *) optval))

		return -EFAULT;



	sctp_sk(sk)->recvrcvinfo = (val == 0) ? 0 : 1;



	return 0;

}



/* API 6.2 setsockopt(), getsockopt()

 *

 * Applications use setsockopt() and getsockopt() to set or retrieve
@@ -3743,6 +3762,9 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname, 
	case SCTP_PEER_ADDR_THLDS:

		retval = sctp_setsockopt_paddr_thresholds(sk, optval, optlen);

		break;

	case SCTP_RECVRCVINFO:

		retval = sctp_setsockopt_recvrcvinfo(sk, optval, optlen);

		break;

	default:

		retval = -ENOPROTOOPT;

		break;
@@ -3989,6 +4011,8 @@ static int sctp_init_sock(struct sock *sk) 
	/* Enable Nagle algorithm by default.  */

	sp->nodelay           = 0;



	sp->recvrcvinfo = 0;



	/* Enable by default. */

	sp->v4mapped          = 1;
@@ -5770,6 +5794,26 @@ static int sctp_getsockopt_assoc_stats(struct sock *sk, int len, 
	return 0;

}



static int sctp_getsockopt_recvrcvinfo(struct sock *sk,	int len,

				       char __user *optval,

				       int __user *optlen)

{

	int val = 0;



	if (len < sizeof(int))

		return -EINVAL;



	len = sizeof(int);

	if (sctp_sk(sk)->recvrcvinfo)

		val = 1;

	if (put_user(len, optlen))

		return -EFAULT;

	if (copy_to_user(optval, &val, len))

		return -EFAULT;



	return 0;

}



static int sctp_getsockopt(struct sock *sk, int level, int optname,

			   char __user *optval, int __user *optlen)

{
@@ -5913,6 +5957,9 @@ static int sctp_getsockopt(struct sock *sk, int level, int optname, 
	case SCTP_GET_ASSOC_STATS:

		retval = sctp_getsockopt_assoc_stats(sk, len, optval, optlen);

		break;

	case SCTP_RECVRCVINFO:

		retval = sctp_getsockopt_recvrcvinfo(sk, len, optval, optlen);

		break;

	default:

		retval = -ENOPROTOOPT;

		break;

net/sctp/ulpevent.c

+25 −0
Original line number Diff line number Diff line
@@ -886,6 +886,31 @@ void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event, 
		 sizeof(sinfo), &sinfo);

}



/* RFC6458, Section 5.3.5 SCTP Receive Information Structure

 * (SCTP_SNDRCV)

 */

void sctp_ulpevent_read_rcvinfo(const struct sctp_ulpevent *event,

				struct msghdr *msghdr)

{

	struct sctp_rcvinfo rinfo;



	if (sctp_ulpevent_is_notification(event))

		return;



	memset(&rinfo, 0, sizeof(struct sctp_rcvinfo));

	rinfo.rcv_sid = event->stream;

	rinfo.rcv_ssn = event->ssn;

	rinfo.rcv_ppid = event->ppid;

	rinfo.rcv_flags = event->flags;

	rinfo.rcv_tsn = event->tsn;

	rinfo.rcv_cumtsn = event->cumtsn;

	rinfo.rcv_assoc_id = sctp_assoc2id(event->asoc);

	rinfo.rcv_context = event->asoc->default_rcv_context;



	put_cmsg(msghdr, IPPROTO_SCTP, SCTP_RCVINFO,

		 sizeof(rinfo), &rinfo);

}



/* Do accounting for bytes received and hold a reference to the association

 * for each skb.

 */