Commit 2347c80f authored by Geir Ola Vaagland's avatar Geir Ola Vaagland Committed by David S. Miller
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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
......@@ -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
......
......@@ -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. */
......
......@@ -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__ */
......@@ -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)
*
......@@ -194,11 +221,12 @@ 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_EOF=MSG_FIN, /* Initiate graceful shutdown process. */
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. */
};
typedef union {
......@@ -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()
*
......
......@@ -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;
......@@ -6602,8 +6646,8 @@ static int sctp_wait_for_packet(struct sock *sk, int *err, long *timeo_p)
* 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,
int noblock, int *err)
struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags,
int noblock, int *err)
{
int error;
struct sk_buff *skb;
......
......@@ -911,6 +911,44 @@ void sctp_ulpevent_read_rcvinfo(const struct sctp_ulpevent *event,
sizeof(rinfo), &rinfo);
}
/* RFC6458, Section 5.3.6. SCTP Next Receive Information Structure
* (SCTP_NXTINFO)
*/
static void __sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,
struct msghdr *msghdr,
const struct sk_buff *skb)
{
struct sctp_nxtinfo nxtinfo;
memset(&nxtinfo, 0, sizeof(nxtinfo));
nxtinfo.nxt_sid = event->stream;
nxtinfo.nxt_ppid = event->ppid;
nxtinfo.nxt_flags = event->flags;
if (sctp_ulpevent_is_notification(event))
nxtinfo.nxt_flags |= SCTP_NOTIFICATION;
nxtinfo.nxt_length = skb->len;
nxtinfo.nxt_assoc_id = sctp_assoc2id(event->asoc);
put_cmsg(msghdr, IPPROTO_SCTP, SCTP_NXTINFO,
sizeof(nxtinfo), &nxtinfo);
}
void sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,
struct msghdr *msghdr,
struct sock *sk)
{
struct sk_buff *skb;
int err;
skb = sctp_skb_recv_datagram(sk, MSG_PEEK, 1, &err);
if (skb != NULL) {
__sctp_ulpevent_read_nxtinfo(sctp_skb2event(skb),
msghdr, skb);
/* Just release refcount here. */
kfree_skb(skb);
}
}
/* Do accounting for bytes received and hold a reference to the association
* for each skb.
*/
......
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