Commit 2347c80f authored by Geir Ola Vaagland's avatar Geir Ola Vaagland Committed by David S. Miller
Browse files

net: sctp: implement rfc6458, 5.3.6. SCTP_NXTINFO cmsg support 



This patch implements section 5.3.6. of RFC6458, that is, support
for 'SCTP Next Receive Information Structure' (SCTP_NXTINFO) which
is placed into ancillary data cmsghdr structure for each recvmsg()
call, if this information is already available when delivering the
current message.

This option can be enabled/disabled via setsockopt(2) on SOL_SCTP
level by setting an int value with 1/0 for SCTP_RECVNXTINFO in
user space applications as per RFC6458, section 8.1.30.

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

  struct sctp_nxtinfo {
    uint16_t nxt_sid;
    uint16_t nxt_flags;
    uint32_t nxt_ppid;
    uint32_t nxt_length;
    sctp_assoc_t nxt_assoc_id;
  };

... and provided under cmsg_level IPPROTO_SCTP, cmsg_type
SCTP_NXTINFO, while cmsg_data[] contains struct sctp_nxtinfo.

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 0d3a421d

include/net/sctp/sctp.h

+1 −0
Original line number Diff line number Diff line
@@ -109,6 +109,7 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk, 
		    struct sctp_association *asoc);

extern struct percpu_counter sctp_sockets_allocated;

int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);

struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);



/*

 * sctp/primitive.c

include/net/sctp/structs.h

+1 −0
Original line number Diff line number Diff line
@@ -218,6 +218,7 @@ struct sctp_sock { 
	__u32 adaptation_ind;

	__u32 pd_point;

	__u8 recvrcvinfo;

	__u8 recvnxtinfo;



	atomic_t pd_mode;

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

include/net/sctp/ulpevent.h

+2 −7
Original line number Diff line number Diff line
@@ -132,6 +132,8 @@ void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event, 
				   struct msghdr *);

void sctp_ulpevent_read_rcvinfo(const struct sctp_ulpevent *event,

				struct msghdr *);

void sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,

				struct msghdr *, struct sock *sk);



__u16 sctp_ulpevent_get_notification_type(const struct sctp_ulpevent *event);
@@ -158,10 +160,3 @@ static inline int sctp_ulpevent_is_enabled(const struct sctp_ulpevent *event, 
}



#endif /* __sctp_ulpevent_h__ */

include/uapi/linux/sctp.h

+35 −12
Original line number Diff line number Diff line
@@ -96,6 +96,7 @@ typedef __s32 sctp_assoc_t; 
#define SCTP_AUTO_ASCONF       30

#define SCTP_PEER_ADDR_THLDS	31

#define SCTP_RECVRCVINFO	32

#define SCTP_RECVNXTINFO	33



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

 * implemented using these socket options.
@@ -111,6 +112,13 @@ typedef __s32 sctp_assoc_t; 
#define SCTP_SOCKOPT_CONNECTX3	111	/* CONNECTX requests (updated) */

#define SCTP_GET_ASSOC_STATS	112	/* Read only */



/* These are bit fields for msghdr->msg_flags.  See section 5.1.  */

/* On user space Linux, these live in <bits/socket.h> as an enum.  */

enum sctp_msg_flags {

	MSG_NOTIFICATION = 0x8000,

#define MSG_NOTIFICATION MSG_NOTIFICATION

};



/* 5.3.1 SCTP Initiation Structure (SCTP_INIT)

 *

 *   This cmsghdr structure provides information for initializing new
@@ -187,6 +195,25 @@ struct sctp_rcvinfo { 
	sctp_assoc_t rcv_assoc_id;

};



/* 5.3.6 SCTP Next Receive Information Structure (SCTP_NXTINFO)

 *

 *   This cmsghdr structure describes SCTP receive information

 *   of the next message that will be delivered through recvmsg()

 *   if this information is already available when delivering

 *   the current message.

 *

 *   cmsg_level    cmsg_type      cmsg_data[]

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

 *   IPPROTO_SCTP  SCTP_NXTINFO   struct sctp_nxtinfo

 */

struct sctp_nxtinfo {

	__u16 nxt_sid;

	__u16 nxt_flags;

	__u32 nxt_ppid;

	__u32 nxt_length;

	sctp_assoc_t nxt_assoc_id;

};



/*

 *  sinfo_flags: 16 bits (unsigned integer)

 *
@@ -194,10 +221,11 @@ struct sctp_rcvinfo { 
 *   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. */

	SCTP_ABORT=4,        /* Send an ABORT message to the peer. */

	SCTP_SACK_IMMEDIATELY = 8,	/* SACK should be sent without delay */

	SCTP_UNORDERED		= (1 << 0), /* Send/receive message unordered. */

	SCTP_ADDR_OVER		= (1 << 1), /* Override the primary destination. */

	SCTP_ABORT		= (1 << 2), /* Send an ABORT message to the peer. */

	SCTP_SACK_IMMEDIATELY	= (1 << 3), /* SACK should be sent without delay. */

	SCTP_NOTIFICATION	= MSG_NOTIFICATION, /* Next message is not user msg but notification. */

	SCTP_EOF		= MSG_FIN,  /* Initiate graceful shutdown process. */

};
@@ -217,6 +245,8 @@ typedef enum sctp_cmsg_type { 
#define SCTP_SNDINFO	SCTP_SNDINFO

	SCTP_RCVINFO,		/* 5.3.5 SCTP Receive Information Structure */

#define SCTP_RCVINFO	SCTP_RCVINFO

	SCTP_NXTINFO,		/* 5.3.6 SCTP Next Receive Information Structure */

#define SCTP_NXTINFO	SCTP_NXTINFO

} sctp_cmsg_t;



/*
@@ -844,13 +874,6 @@ struct sctp_assoc_stats { 
	__u64		sas_ictrlchunks; /* Control chunks received */

};



/* These are bit fields for msghdr->msg_flags.  See section 5.1.  */

/* On user space Linux, these live in <bits/socket.h> as an enum.  */

enum sctp_msg_flags {

	MSG_NOTIFICATION = 0x8000,

#define MSG_NOTIFICATION MSG_NOTIFICATION

};



/*

 * 8.1 sctp_bindx()

 *

net/sctp/socket.c

+48 −4
Original line number Diff line number Diff line
@@ -2060,8 +2060,6 @@ static int sctp_skb_pull(struct sk_buff *skb, int len) 
 *  flags   - flags sent or received with the user message, see Section

 *            5 for complete description of the flags.

 */

static struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);



static int sctp_recvmsg(struct kiocb *iocb, struct sock *sk,

			struct msghdr *msg, size_t len, int noblock,

			int flags, int *addr_len)
@@ -2112,6 +2110,9 @@ 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_NXTINFO. */

	if (sp->recvnxtinfo)

		sctp_ulpevent_read_nxtinfo(event, msg, sk);

	/* Check if we allow SCTP_RCVINFO. */

	if (sp->recvrcvinfo)

		sctp_ulpevent_read_rcvinfo(event, msg);
@@ -3611,6 +3612,22 @@ static int sctp_setsockopt_recvrcvinfo(struct sock *sk, 
	return 0;

}



static int sctp_setsockopt_recvnxtinfo(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)->recvnxtinfo = (val == 0) ? 0 : 1;



	return 0;

}



/* API 6.2 setsockopt(), getsockopt()

 *

 * Applications use setsockopt() and getsockopt() to set or retrieve
@@ -3765,6 +3782,9 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname, 
	case SCTP_RECVRCVINFO:

		retval = sctp_setsockopt_recvrcvinfo(sk, optval, optlen);

		break;

	case SCTP_RECVNXTINFO:

		retval = sctp_setsockopt_recvnxtinfo(sk, optval, optlen);

		break;

	default:

		retval = -ENOPROTOOPT;

		break;
@@ -4012,6 +4032,7 @@ static int sctp_init_sock(struct sock *sk) 
	sp->nodelay           = 0;



	sp->recvrcvinfo = 0;

	sp->recvnxtinfo = 0;



	/* Enable by default. */

	sp->v4mapped          = 1;
@@ -5814,6 +5835,26 @@ static int sctp_getsockopt_recvrcvinfo(struct sock *sk, int len, 
	return 0;

}



static int sctp_getsockopt_recvnxtinfo(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)->recvnxtinfo)

		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)

{
@@ -5960,6 +6001,9 @@ static int sctp_getsockopt(struct sock *sk, int level, int optname, 
	case SCTP_RECVRCVINFO:

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

		break;

	case SCTP_RECVNXTINFO:

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

		break;

	default:

		retval = -ENOPROTOOPT;

		break;
@@ -6602,7 +6646,7 @@ out: 
 * Note: This is pretty much the same routine as in core/datagram.c

 * with a few changes to make lksctp work.

 */

static struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags,

struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags,

				       int noblock, int *err)

{

	int error;

CRA Git | Maintained and supported by SUSTech CRA and CCSE