From 2347c80ff127b94ddaa675e2b78ab4cef46dc905 Mon Sep 17 00:00:00 2001 From: Geir Ola Vaagland Date: Sat, 12 Jul 2014 20:30:38 +0200 Subject: [PATCH] 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: Geir Ola Vaagland Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller --- include/net/sctp/sctp.h | 1 + include/net/sctp/structs.h | 1 + include/net/sctp/ulpevent.h | 9 ++----- include/uapi/linux/sctp.h | 47 ++++++++++++++++++++++++--------- net/sctp/socket.c | 52 ++++++++++++++++++++++++++++++++++--- net/sctp/ulpevent.c | 38 +++++++++++++++++++++++++++ 6 files changed, 125 insertions(+), 23 deletions(-) diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index c2035c96a2ee..90c1cccd164d 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -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 diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 11d5df015370..7741d1b66967 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -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. */ diff --git a/include/net/sctp/ulpevent.h b/include/net/sctp/ulpevent.h index e8095f973e94..cccdcfd14973 100644 --- a/include/net/sctp/ulpevent.h +++ b/include/net/sctp/ulpevent.h @@ -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__ */ - - - - - - - diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h index 29b81bbfc53d..222f82ffeca4 100644 --- a/include/uapi/linux/sctp.h +++ b/include/uapi/linux/sctp.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 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 as an enum. */ -enum sctp_msg_flags { - MSG_NOTIFICATION = 0x8000, -#define MSG_NOTIFICATION MSG_NOTIFICATION -}; - /* * 8.1 sctp_bindx() * diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 9c193887c5cd..9bca87ee5152 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -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 @@ 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, - 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; diff --git a/net/sctp/ulpevent.c b/net/sctp/ulpevent.c index b31f365f18ab..e049298ecfa0 100644 --- a/net/sctp/ulpevent.c +++ b/net/sctp/ulpevent.c @@ -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. */ -- 2.39.5