/* * net/tipc/socket.c: TIPC socket API * * Copyright (c) 2001-2006, Ericsson AB * Copyright (c) 2004-2005, Wind River Systems * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the names of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include <linux/module.h> #include <linux/types.h> #include <linux/net.h> #include <linux/socket.h> #include <linux/errno.h> #include <linux/mm.h> #include <linux/slab.h> #include <linux/poll.h> #include <linux/fcntl.h> #include <asm/semaphore.h> #include <asm/string.h> #include <asm/atomic.h> #include <net/sock.h> #include <linux/tipc.h> #include <linux/tipc_config.h> #include <net/tipc/tipc_msg.h> #include <net/tipc/tipc_port.h> #include "core.h" #define SS_LISTENING -1 /* socket is listening */ #define SS_READY -2 /* socket is connectionless */ #define OVERLOAD_LIMIT_BASE 5000 struct tipc_sock { struct sock sk; struct tipc_port *p; struct semaphore sem; }; #define tipc_sk(sk) ((struct tipc_sock*)sk) static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf); static void wakeupdispatch(struct tipc_port *tport); static struct proto_ops packet_ops; static struct proto_ops stream_ops; static struct proto_ops msg_ops; static struct proto tipc_proto; static int sockets_enabled = 0; static atomic_t tipc_queue_size = ATOMIC_INIT(0); /* * sock_lock(): Lock a port/socket pair. lock_sock() can * not be used here, since the same lock must protect ports * with non-socket interfaces. * See net.c for description of locking policy. */ static void sock_lock(struct tipc_sock* tsock) { spin_lock_bh(tsock->p->lock); } /* * sock_unlock(): Unlock a port/socket pair */ static void sock_unlock(struct tipc_sock* tsock) { spin_unlock_bh(tsock->p->lock); } /** * pollmask - determine the current set of poll() events for a socket * @sock: socket structure * * TIPC sets the returned events as follows: * a) POLLRDNORM and POLLIN are set if the socket's receive queue is non-empty * or if a connection-oriented socket is does not have an active connection * (i.e. a read operation will not block). * b) POLLOUT is set except when a socket's connection has been terminated * (i.e. a write operation will not block). * c) POLLHUP is set when a socket's connection has been terminated. * * IMPORTANT: The fact that a read or write operation will not block does NOT * imply that the operation will succeed! * * Returns pollmask value */ static u32 pollmask(struct socket *sock) { u32 mask; if ((skb_queue_len(&sock->sk->sk_receive_queue) != 0) || (sock->state == SS_UNCONNECTED) || (sock->state == SS_DISCONNECTING)) mask = (POLLRDNORM | POLLIN); else mask = 0; if (sock->state == SS_DISCONNECTING) mask |= POLLHUP; else mask |= POLLOUT; return mask; } /** * advance_queue - discard first buffer in queue * @tsock: TIPC socket */ static void advance_queue(struct tipc_sock *tsock) { sock_lock(tsock); buf_discard(skb_dequeue(&tsock->sk.sk_receive_queue)); sock_unlock(tsock); atomic_dec(&tipc_queue_size); } /** * tipc_create - create a TIPC socket * @sock: pre-allocated socket structure * @protocol: protocol indicator (must be 0) * * This routine creates and attaches a 'struct sock' to the 'struct socket', * then create and attaches a TIPC port to the 'struct sock' part. * * Returns 0 on success, errno otherwise */ static int tipc_create(struct socket *sock, int protocol) { struct tipc_sock *tsock; struct tipc_port *port; struct sock *sk; u32 ref; if (unlikely(protocol != 0)) return -EPROTONOSUPPORT; ref = tipc_createport_raw(NULL, &dispatch, &wakeupdispatch, TIPC_LOW_IMPORTANCE); if (unlikely(!ref)) return -ENOMEM; sock->state = SS_UNCONNECTED; switch (sock->type) { case SOCK_STREAM: sock->ops = &stream_ops; break; case SOCK_SEQPACKET: sock->ops = &packet_ops; break; case SOCK_DGRAM: tipc_set_portunreliable(ref, 1); /* fall through */ case SOCK_RDM: tipc_set_portunreturnable(ref, 1); sock->ops = &msg_ops; sock->state = SS_READY; break; default: tipc_deleteport(ref); return -EPROTOTYPE; } sk = sk_alloc(AF_TIPC, GFP_KERNEL, &tipc_proto, 1); if (!sk) { tipc_deleteport(ref); return -ENOMEM; } sock_init_data(sock, sk); init_waitqueue_head(sk->sk_sleep); sk->sk_rcvtimeo = 8 * HZ; /* default connect timeout = 8s */ tsock = tipc_sk(sk); port = tipc_get_port(ref); tsock->p = port; port->usr_handle = tsock; init_MUTEX(&tsock->sem); dbg("sock_create: %x\n",tsock); atomic_inc(&tipc_user_count); return 0; } /** * release - destroy a TIPC socket * @sock: socket to destroy * * This routine cleans up any messages that are still queued on the socket. * For DGRAM and RDM socket types, all queued messages are rejected. * For SEQPACKET and STREAM socket types, the first message is rejected * and any others are discarded. (If the first message on a STREAM socket * is partially-read, it is discarded and the next one is rejected instead.) * * NOTE: Rejected messages are not necessarily returned to the sender! They * are returned or discarded according to the "destination droppable" setting * specified for the message by the sender. * * Returns 0 on success, errno otherwise */ static int release(struct socket *sock) { struct tipc_sock *tsock = tipc_sk(sock->sk); struct sock *sk = sock->sk; int res = TIPC_OK; struct sk_buff *buf; dbg("sock_delete: %x\n",tsock); if (!tsock) return 0; down_interruptible(&tsock->sem); if (!sock->sk) { up(&tsock->sem); return 0; } /* Reject unreceived messages, unless no longer connected */ while (sock->state != SS_DISCONNECTING) { sock_lock(tsock); buf = skb_dequeue(&sk->sk_receive_queue); if (!buf) tsock->p->usr_handle = NULL; sock_unlock(tsock); if (!buf) break; if (TIPC_SKB_CB(buf)->handle != msg_data(buf_msg(buf))) buf_discard(buf); else tipc_reject_msg(buf, TIPC_ERR_NO_PORT); atomic_dec(&tipc_queue_size); } /* Delete TIPC port */ res = tipc_deleteport(tsock->p->ref); sock->sk = NULL; /* Discard any remaining messages */ while ((buf = skb_dequeue(&sk->sk_receive_queue))) { buf_discard(buf); atomic_dec(&tipc_queue_size); } up(&tsock->sem); sock_put(sk); atomic_dec(&tipc_user_count); return res; } /** * bind - associate or disassocate TIPC name(s) with a socket * @sock: socket structure * @uaddr: socket address describing name(s) and desired operation * @uaddr_len: size of socket address data structure * * Name and name sequence binding is indicated using a positive scope value; * a negative scope value unbinds the specified name. Specifying no name * (i.e. a socket address length of 0) unbinds all names from the socket. * * Returns 0 on success, errno otherwise */ static int bind(struct socket *sock, struct sockaddr *uaddr, int uaddr_len) { struct tipc_sock *tsock = tipc_sk(sock->sk); struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr; int res; if (down_interruptible(&tsock->sem)) return -ERESTARTSYS; if (unlikely(!uaddr_len)) { res = tipc_withdraw(tsock->p->ref, 0, NULL); goto exit; } if (uaddr_len < sizeof(struct sockaddr_tipc)) { res = -EINVAL; goto exit; } if (addr->family != AF_TIPC) { res = -EAFNOSUPPORT; goto exit; } if (addr->addrtype == TIPC_ADDR_NAME) addr->addr.nameseq.upper = addr->addr.nameseq.lower; else if (addr->addrtype != TIPC_ADDR_NAMESEQ) { res = -EAFNOSUPPORT; goto exit; } if (addr->scope > 0) res = tipc_publish(tsock->p->ref, addr->scope, &addr->addr.nameseq); else res = tipc_withdraw(tsock->p->ref, -addr->scope, &addr->addr.nameseq); exit: up(&tsock->sem); return res; } /** * get_name - get port ID of socket or peer socket * @sock: socket structure * @uaddr: area for returned socket address * @uaddr_len: area for returned length of socket address * @peer: 0 to obtain socket name, 1 to obtain peer socket name * * Returns 0 on success, errno otherwise */ static int get_name(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) { struct tipc_sock *tsock = tipc_sk(sock->sk); struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr; u32 res; if (down_interruptible(&tsock->sem)) return -ERESTARTSYS; *uaddr_len = sizeof(*addr); addr->addrtype = TIPC_ADDR_ID; addr->family = AF_TIPC; addr->scope = 0; if (peer) res = tipc_peer(tsock->p->ref, &addr->addr.id); else res = tipc_ownidentity(tsock->p->ref, &addr->addr.id); addr->addr.name.domain = 0; up(&tsock->sem); return res; } /** * poll - read and possibly block on pollmask * @file: file structure associated with the socket * @sock: socket for which to calculate the poll bits * @wait: ??? * * Returns the pollmask */ static unsigned int poll(struct file *file, struct socket *sock, poll_table *wait) { poll_wait(file, sock->sk->sk_sleep, wait); /* NEED LOCK HERE? */ return pollmask(sock); } /** * dest_name_check - verify user is permitted to send to specified port name * @dest: destination address * @m: descriptor for message to be sent * * Prevents restricted configuration commands from being issued by * unauthorized users. * * Returns 0 if permission is granted, otherwise errno */ static int dest_name_check(struct sockaddr_tipc *dest, struct msghdr *m) { struct tipc_cfg_msg_hdr hdr; if (likely(dest->addr.name.name.type >= TIPC_RESERVED_TYPES)) return 0; if (likely(dest->addr.name.name.type == TIPC_TOP_SRV)) return 0; if (likely(dest->addr.name.name.type != TIPC_CFG_SRV)) return -EACCES; if (copy_from_user(&hdr, m->msg_iov[0].iov_base, sizeof(hdr))) return -EFAULT; if ((ntohs(hdr.tcm_type) & 0xC000) && (!capable(CAP_NET_ADMIN))) return -EACCES; return 0; } /** * send_msg - send message in connectionless manner * @iocb: (unused) * @sock: socket structure * @m: message to send * @total_len: length of message * * Message must have an destination specified explicitly. * Used for SOCK_RDM and SOCK_DGRAM messages, * and for 'SYN' messages on SOCK_SEQPACKET and SOCK_STREAM connections. * (Note: 'SYN+' is prohibited on SOCK_STREAM.) * * Returns the number of bytes sent on success, or errno otherwise */ static int send_msg(struct kiocb *iocb, struct socket *sock, struct msghdr *m, size_t total_len) { struct tipc_sock *tsock = tipc_sk(sock->sk); struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name; struct sk_buff *buf; int needs_conn; int res = -EINVAL; if (unlikely(!dest)) return -EDESTADDRREQ; if (unlikely((m->msg_namelen < sizeof(*dest)) || (dest->family != AF_TIPC))) return -EINVAL; needs_conn = (sock->state != SS_READY); if (unlikely(needs_conn)) { if (sock->state == SS_LISTENING) return -EPIPE; if (sock->state != SS_UNCONNECTED) return -EISCONN; if ((tsock->p->published) || ((sock->type == SOCK_STREAM) && (total_len != 0))) return -EOPNOTSUPP; if (dest->addrtype == TIPC_ADDR_NAME) { tsock->p->conn_type = dest->addr.name.name.type; tsock->p->conn_instance = dest->addr.name.name.instance; } } if (down_interruptible(&tsock->sem)) return -ERESTARTSYS; if (needs_conn) { /* Abort any pending connection attempts (very unlikely) */ while ((buf = skb_dequeue(&sock->sk->sk_receive_queue))) { tipc_reject_msg(buf, TIPC_ERR_NO_PORT); atomic_dec(&tipc_queue_size); } sock->state = SS_CONNECTING; } do { if (dest->addrtype == TIPC_ADDR_NAME) { if ((res = dest_name_check(dest, m))) goto exit; res = tipc_send2name(tsock->p->ref, &dest->addr.name.name, dest->addr.name.domain, m->msg_iovlen, m->msg_iov); } else if (dest->addrtype == TIPC_ADDR_ID) { res = tipc_send2port(tsock->p->ref, &dest->addr.id, m->msg_iovlen, m->msg_iov); } else if (dest->addrtype == TIPC_ADDR_MCAST) { if (needs_conn) { res = -EOPNOTSUPP; goto exit; } if ((res = dest_name_check(dest, m))) goto exit; res = tipc_multicast(tsock->p->ref, &dest->addr.nameseq, 0, m->msg_iovlen, m->msg_iov); } if (likely(res != -ELINKCONG)) { exit: up(&tsock->sem); return res; } if (m->msg_flags & MSG_DONTWAIT) { res = -EWOULDBLOCK; goto exit; } if (wait_event_interruptible(*sock->sk->sk_sleep, !tsock->p->congested)) { res = -ERESTARTSYS; goto exit; } } while (1); } /** * send_packet - send a connection-oriented message * @iocb: (unused) * @sock: socket structure * @m: message to send * @total_len: length of message * * Used for SOCK_SEQPACKET messages and SOCK_STREAM data. * * Returns the number of bytes sent on success, or errno otherwise */ static int send_packet(struct kiocb *iocb, struct socket *sock, struct msghdr *m, size_t total_len) { struct tipc_sock *tsock = tipc_sk(sock->sk); struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name; int res; /* Handle implied connection establishment */ if (unlikely(dest)) return send_msg(iocb, sock, m, total_len); if (down_interruptible(&tsock->sem)) { return -ERESTARTSYS; } do { if (unlikely(sock->state != SS_CONNECTED)) { if (sock->state == SS_DISCONNECTING) res = -EPIPE; else res = -ENOTCONN; goto exit; } res = tipc_send(tsock->p->ref, m->msg_iovlen, m->msg_iov); if (likely(res != -ELINKCONG)) { exit: up(&tsock->sem); return res; } if (m->msg_flags & MSG_DONTWAIT) { res = -EWOULDBLOCK; goto exit; } if (wait_event_interruptible(*sock->sk->sk_sleep, !tsock->p->congested)) { res = -ERESTARTSYS; goto exit; } } while (1); } /** * send_stream - send stream-oriented data * @iocb: (unused) * @sock: socket structure * @m: data to send * @total_len: total length of data to be sent * * Used for SOCK_STREAM data. * * Returns the number of bytes sent on success (or partial success), * or errno if no data sent */ static int send_stream(struct kiocb *iocb, struct socket *sock, struct msghdr *m, size_t total_len) { struct msghdr my_msg; struct iovec my_iov; struct iovec *curr_iov; int curr_iovlen; char __user *curr_start; int curr_left; int bytes_to_send; int bytes_sent; int res; if (likely(total_len <= TIPC_MAX_USER_MSG_SIZE)) return send_packet(iocb, sock, m, total_len); /* Can only send large data streams if already connected */ if (unlikely(sock->state != SS_CONNECTED)) { if (sock->state == SS_DISCONNECTING) return -EPIPE; else return -ENOTCONN; } /* * Send each iovec entry using one or more messages * * Note: This algorithm is good for the most likely case * (i.e. one large iovec entry), but could be improved to pass sets * of small iovec entries into send_packet(). */ curr_iov = m->msg_iov; curr_iovlen = m->msg_iovlen; my_msg.msg_iov = &my_iov; my_msg.msg_iovlen = 1; bytes_sent = 0; while (curr_iovlen--) { curr_start = curr_iov->iov_base; curr_left = curr_iov->iov_len; while (curr_left) { bytes_to_send = (curr_left < TIPC_MAX_USER_MSG_SIZE) ? curr_left : TIPC_MAX_USER_MSG_SIZE; my_iov.iov_base = curr_start; my_iov.iov_len = bytes_to_send; if ((res = send_packet(iocb, sock, &my_msg, 0)) < 0) { return bytes_sent ? bytes_sent : res; } curr_left -= bytes_to_send; curr_start += bytes_to_send; bytes_sent += bytes_to_send; } curr_iov++; } return bytes_sent; } /** * auto_connect - complete connection setup to a remote port * @sock: socket structure * @tsock: TIPC-specific socket structure * @msg: peer's response message * * Returns 0 on success, errno otherwise */ static int auto_connect(struct socket *sock, struct tipc_sock *tsock, struct tipc_msg *msg) { struct tipc_portid peer; if (msg_errcode(msg)) { sock->state = SS_DISCONNECTING; return -ECONNREFUSED; } peer.ref = msg_origport(msg); peer.node = msg_orignode(msg); tipc_connect2port(tsock->p->ref, &peer); tipc_set_portimportance(tsock->p->ref, msg_importance(msg)); sock->state = SS_CONNECTED; return 0; } /** * set_orig_addr - capture sender's address for received message * @m: descriptor for message info * @msg: received message header * * Note: Address is not captured if not requested by receiver. */ static void set_orig_addr(struct msghdr *m, struct tipc_msg *msg) { struct sockaddr_tipc *addr = (struct sockaddr_tipc *)m->msg_name; if (addr) { addr->family = AF_TIPC; addr->addrtype = TIPC_ADDR_ID; addr->addr.id.ref = msg_origport(msg); addr->addr.id.node = msg_orignode(msg); addr->addr.name.domain = 0; /* could leave uninitialized */ addr->scope = 0; /* could leave uninitialized */ m->msg_namelen = sizeof(struct sockaddr_tipc); } } /** * anc_data_recv - optionally capture ancillary data for received message * @m: descriptor for message info * @msg: received message header * @tport: TIPC port associated with message * * Note: Ancillary data is not captured if not requested by receiver. * * Returns 0 if successful, otherwise errno */ static int anc_data_recv(struct msghdr *m, struct tipc_msg *msg, struct tipc_port *tport) { u32 anc_data[3]; u32 err; u32 dest_type; int has_name; int res; if (likely(m->msg_controllen == 0)) return 0; /* Optionally capture errored message object(s) */ err = msg ? msg_errcode(msg) : 0; if (unlikely(err)) { anc_data[0] = err; anc_data[1] = msg_data_sz(msg); if ((res = put_cmsg(m, SOL_TIPC, TIPC_ERRINFO, 8, anc_data))) return res; if (anc_data[1] && (res = put_cmsg(m, SOL_TIPC, TIPC_RETDATA, anc_data[1], msg_data(msg)))) return res; } /* Optionally capture message destination object */ dest_type = msg ? msg_type(msg) : TIPC_DIRECT_MSG; switch (dest_type) { case TIPC_NAMED_MSG: has_name = 1; anc_data[0] = msg_nametype(msg); anc_data[1] = msg_namelower(msg); anc_data[2] = msg_namelower(msg); break; case TIPC_MCAST_MSG: has_name = 1; anc_data[0] = msg_nametype(msg); anc_data[1] = msg_namelower(msg); anc_data[2] = msg_nameupper(msg); break; case TIPC_CONN_MSG: has_name = (tport->conn_type != 0); anc_data[0] = tport->conn_type; anc_data[1] = tport->conn_instance; anc_data[2] = tport->conn_instance; break; default: has_name = 0; } if (has_name && (res = put_cmsg(m, SOL_TIPC, TIPC_DESTNAME, 12, anc_data))) return res; return 0; } /** * recv_msg - receive packet-oriented message * @iocb: (unused) * @m: descriptor for message info * @buf_len: total size of user buffer area * @flags: receive flags * * Used for SOCK_DGRAM, SOCK_RDM, and SOCK_SEQPACKET messages. * If the complete message doesn't fit in user area, truncate it. * * Returns size of returned message data, errno otherwise */ static int recv_msg(struct kiocb *iocb, struct socket *sock, struct msghdr *m, size_t buf_len, int flags) { struct tipc_sock *tsock = tipc_sk(sock->sk); struct sk_buff *buf; struct tipc_msg *msg; unsigned int q_len; unsigned int sz; u32 err; int res; /* Currently doesn't support receiving into multiple iovec entries */ if (m->msg_iovlen != 1) return -EOPNOTSUPP; /* Catch invalid receive attempts */ if (unlikely(!buf_len)) return -EINVAL; if (sock->type == SOCK_SEQPACKET) { if (unlikely(sock->state == SS_UNCONNECTED)) return -ENOTCONN; if (unlikely((sock->state == SS_DISCONNECTING) && (skb_queue_len(&sock->sk->sk_receive_queue) == 0))) return -ENOTCONN; } /* Look for a message in receive queue; wait if necessary */ if (unlikely(down_interruptible(&tsock->sem))) return -ERESTARTSYS; restart: if (unlikely((skb_queue_len(&sock->sk->sk_receive_queue) == 0) && (flags & MSG_DONTWAIT))) { res = -EWOULDBLOCK; goto exit; } if ((res = wait_event_interruptible( *sock->sk->sk_sleep, ((q_len = skb_queue_len(&sock->sk->sk_receive_queue)) || (sock->state == SS_DISCONNECTING))) )) { goto exit; } /* Catch attempt to receive on an already terminated connection */ /* [THIS CHECK MAY OVERLAP WITH AN EARLIER CHECK] */ if (!q_len) { res = -ENOTCONN; goto exit; } /* Get access to first message in receive queue */ buf = skb_peek(&sock->sk->sk_receive_queue); msg = buf_msg(buf); sz = msg_data_sz(msg); err = msg_errcode(msg); /* Complete connection setup for an implied connect */ if (unlikely(sock->state == SS_CONNECTING)) { if ((res = auto_connect(sock, tsock, msg))) goto exit; } /* Discard an empty non-errored message & try again */ if ((!sz) && (!err)) { advance_queue(tsock); goto restart; } /* Capture sender's address (optional) */ set_orig_addr(m, msg); /* Capture ancillary data (optional) */ if ((res = anc_data_recv(m, msg, tsock->p))) goto exit; /* Capture message data (if valid) & compute return value (always) */ if (!err) { if (unlikely(buf_len < sz)) { sz = buf_len; m->msg_flags |= MSG_TRUNC; } if (unlikely(copy_to_user(m->msg_iov->iov_base, msg_data(msg), sz))) { res = -EFAULT; goto exit; } res = sz; } else { if ((sock->state == SS_READY) || ((err == TIPC_CONN_SHUTDOWN) || m->msg_control)) res = 0; else res = -ECONNRESET; } /* Consume received message (optional) */ if (likely(!(flags & MSG_PEEK))) { if (unlikely(++tsock->p->conn_unacked >= TIPC_FLOW_CONTROL_WIN)) tipc_acknowledge(tsock->p->ref, tsock->p->conn_unacked); advance_queue(tsock); } exit: up(&tsock->sem); return res; } /** * recv_stream - receive stream-oriented data * @iocb: (unused) * @m: descriptor for message info * @buf_len: total size of user buffer area * @flags: receive flags * * Used for SOCK_STREAM messages only. If not enough data is available * will optionally wait for more; never truncates data. * * Returns size of returned message data, errno otherwise */ static int recv_stream(struct kiocb *iocb, struct socket *sock, struct msghdr *m, size_t buf_len, int flags) { struct tipc_sock *tsock = tipc_sk(sock->sk); struct sk_buff *buf; struct tipc_msg *msg; unsigned int q_len; unsigned int sz; int sz_to_copy; int sz_copied = 0; int needed; char *crs = m->msg_iov->iov_base; unsigned char *buf_crs; u32 err; int res; /* Currently doesn't support receiving into multiple iovec entries */ if (m->msg_iovlen != 1) return -EOPNOTSUPP; /* Catch invalid receive attempts */ if (unlikely(!buf_len)) return -EINVAL; if (unlikely(sock->state == SS_DISCONNECTING)) { if (skb_queue_len(&sock->sk->sk_receive_queue) == 0) return -ENOTCONN; } else if (unlikely(sock->state != SS_CONNECTED)) return -ENOTCONN; /* Look for a message in receive queue; wait if necessary */ if (unlikely(down_interruptible(&tsock->sem))) return -ERESTARTSYS; restart: if (unlikely((skb_queue_len(&sock->sk->sk_receive_queue) == 0) && (flags & MSG_DONTWAIT))) { res = -EWOULDBLOCK; goto exit; } if ((res = wait_event_interruptible( *sock->sk->sk_sleep, ((q_len = skb_queue_len(&sock->sk->sk_receive_queue)) || (sock->state == SS_DISCONNECTING))) )) { goto exit; } /* Catch attempt to receive on an already terminated connection */ /* [THIS CHECK MAY OVERLAP WITH AN EARLIER CHECK] */ if (!q_len) { res = -ENOTCONN; goto exit; } /* Get access to first message in receive queue */ buf = skb_peek(&sock->sk->sk_receive_queue); msg = buf_msg(buf); sz = msg_data_sz(msg); err = msg_errcode(msg); /* Discard an empty non-errored message & try again */ if ((!sz) && (!err)) { advance_queue(tsock); goto restart; } /* Optionally capture sender's address & ancillary data of first msg */ if (sz_copied == 0) { set_orig_addr(m, msg); if ((res = anc_data_recv(m, msg, tsock->p))) goto exit; } /* Capture message data (if valid) & compute return value (always) */ if (!err) { buf_crs = (unsigned char *)(TIPC_SKB_CB(buf)->handle); sz = buf->tail - buf_crs; needed = (buf_len - sz_copied); sz_to_copy = (sz <= needed) ? sz : needed; if (unlikely(copy_to_user(crs, buf_crs, sz_to_copy))) { res = -EFAULT; goto exit; } sz_copied += sz_to_copy; if (sz_to_copy < sz) { if (!(flags & MSG_PEEK)) TIPC_SKB_CB(buf)->handle = buf_crs + sz_to_copy; goto exit; } crs += sz_to_copy; } else { if (sz_copied != 0) goto exit; /* can't add error msg to valid data */ if ((err == TIPC_CONN_SHUTDOWN) || m->msg_control) res = 0; else res = -ECONNRESET; } /* Consume received message (optional) */ if (likely(!(flags & MSG_PEEK))) { if (unlikely(++tsock->p->conn_unacked >= TIPC_FLOW_CONTROL_WIN)) tipc_acknowledge(tsock->p->ref, tsock->p->conn_unacked); advance_queue(tsock); } /* Loop around if more data is required */ if ((sz_copied < buf_len) /* didn't get all requested data */ && (flags & MSG_WAITALL) /* ... and need to wait for more */ && (!(flags & MSG_PEEK)) /* ... and aren't just peeking at data */ && (!err) /* ... and haven't reached a FIN */ ) goto restart; exit: up(&tsock->sem); return sz_copied ? sz_copied : res; } /** * queue_overloaded - test if queue overload condition exists * @queue_size: current size of queue * @base: nominal maximum size of queue * @msg: message to be added to queue * * Returns 1 if queue is currently overloaded, 0 otherwise */ static int queue_overloaded(u32 queue_size, u32 base, struct tipc_msg *msg) { u32 threshold; u32 imp = msg_importance(msg); if (imp == TIPC_LOW_IMPORTANCE) threshold = base; else if (imp == TIPC_MEDIUM_IMPORTANCE) threshold = base * 2; else if (imp == TIPC_HIGH_IMPORTANCE) threshold = base * 100; else return 0; if (msg_connected(msg)) threshold *= 4; return (queue_size > threshold); } /** * async_disconnect - wrapper function used to disconnect port * @portref: TIPC port reference (passed as pointer-sized value) */ static void async_disconnect(unsigned long portref) { tipc_disconnect((u32)portref); } /** * dispatch - handle arriving message * @tport: TIPC port that received message * @buf: message * * Called with port locked. Must not take socket lock to avoid deadlock risk. * * Returns TIPC error status code (TIPC_OK if message is not to be rejected) */ static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf) { struct tipc_msg *msg = buf_msg(buf); struct tipc_sock *tsock = (struct tipc_sock *)tport->usr_handle; struct socket *sock; u32 recv_q_len; /* Reject message if socket is closing */ if (!tsock) return TIPC_ERR_NO_PORT; /* Reject message if it is wrong sort of message for socket */ /* * WOULD IT BE BETTER TO JUST DISCARD THESE MESSAGES INSTEAD? * "NO PORT" ISN'T REALLY THE RIGHT ERROR CODE, AND THERE MAY * BE SECURITY IMPLICATIONS INHERENT IN REJECTING INVALID TRAFFIC */ sock = tsock->sk.sk_socket; if (sock->state == SS_READY) { if (msg_connected(msg)) { msg_dbg(msg, "dispatch filter 1\n"); return TIPC_ERR_NO_PORT; } } else { if (msg_mcast(msg)) { msg_dbg(msg, "dispatch filter 2\n"); return TIPC_ERR_NO_PORT; } if (sock->state == SS_CONNECTED) { if (!msg_connected(msg)) { msg_dbg(msg, "dispatch filter 3\n"); return TIPC_ERR_NO_PORT; } } else if (sock->state == SS_CONNECTING) { if (!msg_connected(msg) && (msg_errcode(msg) == 0)) { msg_dbg(msg, "dispatch filter 4\n"); return TIPC_ERR_NO_PORT; } } else if (sock->state == SS_LISTENING) { if (msg_connected(msg) || msg_errcode(msg)) { msg_dbg(msg, "dispatch filter 5\n"); return TIPC_ERR_NO_PORT; } } else if (sock->state == SS_DISCONNECTING) { msg_dbg(msg, "dispatch filter 6\n"); return TIPC_ERR_NO_PORT; } else /* (sock->state == SS_UNCONNECTED) */ { if (msg_connected(msg) || msg_errcode(msg)) { msg_dbg(msg, "dispatch filter 7\n"); return TIPC_ERR_NO_PORT; } } } /* Reject message if there isn't room to queue it */ if (unlikely((u32)atomic_read(&tipc_queue_size) > OVERLOAD_LIMIT_BASE)) { if (queue_overloaded(atomic_read(&tipc_queue_size), OVERLOAD_LIMIT_BASE, msg)) return TIPC_ERR_OVERLOAD; } recv_q_len = skb_queue_len(&tsock->sk.sk_receive_queue); if (unlikely(recv_q_len > (OVERLOAD_LIMIT_BASE / 2))) { if (queue_overloaded(recv_q_len, OVERLOAD_LIMIT_BASE / 2, msg)) return TIPC_ERR_OVERLOAD; } /* Initiate connection termination for an incoming 'FIN' */ if (unlikely(msg_errcode(msg) && (sock->state == SS_CONNECTED))) { sock->state = SS_DISCONNECTING; /* Note: Use signal since port lock is already taken! */ tipc_k_signal((Handler)async_disconnect, tport->ref); } /* Enqueue message (finally!) */ msg_dbg(msg,"<DISP<: "); TIPC_SKB_CB(buf)->handle = msg_data(msg); atomic_inc(&tipc_queue_size); skb_queue_tail(&sock->sk->sk_receive_queue, buf); wake_up_interruptible(sock->sk->sk_sleep); return TIPC_OK; } /** * wakeupdispatch - wake up port after congestion * @tport: port to wakeup * * Called with port lock on. */ static void wakeupdispatch(struct tipc_port *tport) { struct tipc_sock *tsock = (struct tipc_sock *)tport->usr_handle; wake_up_interruptible(tsock->sk.sk_sleep); } /** * connect - establish a connection to another TIPC port * @sock: socket structure * @dest: socket address for destination port * @destlen: size of socket address data structure * @flags: (unused) * * Returns 0 on success, errno otherwise */ static int connect(struct socket *sock, struct sockaddr *dest, int destlen, int flags) { struct tipc_sock *tsock = tipc_sk(sock->sk); struct sockaddr_tipc *dst = (struct sockaddr_tipc *)dest; struct msghdr m = {NULL,}; struct sk_buff *buf; struct tipc_msg *msg; int res; /* For now, TIPC does not allow use of connect() with DGRAM or RDM types */ if (sock->state == SS_READY) return -EOPNOTSUPP; /* Issue Posix-compliant error code if socket is in the wrong state */ if (sock->state == SS_LISTENING) return -EOPNOTSUPP; if (sock->state == SS_CONNECTING) return -EALREADY; if (sock->state != SS_UNCONNECTED) return -EISCONN; /* * Reject connection attempt using multicast address * * Note: send_msg() validates the rest of the address fields, * so there's no need to do it here */ if (dst->addrtype == TIPC_ADDR_MCAST) return -EINVAL; /* Send a 'SYN-' to destination */ m.msg_name = dest; m.msg_namelen = destlen; if ((res = send_msg(NULL, sock, &m, 0)) < 0) { sock->state = SS_DISCONNECTING; return res; } if (down_interruptible(&tsock->sem)) return -ERESTARTSYS; /* Wait for destination's 'ACK' response */ res = wait_event_interruptible_timeout(*sock->sk->sk_sleep, skb_queue_len(&sock->sk->sk_receive_queue), sock->sk->sk_rcvtimeo); buf = skb_peek(&sock->sk->sk_receive_queue); if (res > 0) { msg = buf_msg(buf); res = auto_connect(sock, tsock, msg); if (!res) { if (!msg_data_sz(msg)) advance_queue(tsock); } } else { if (res == 0) { res = -ETIMEDOUT; } else { /* leave "res" unchanged */ } sock->state = SS_DISCONNECTING; } up(&tsock->sem); return res; } /** * listen - allow socket to listen for incoming connections * @sock: socket structure * @len: (unused) * * Returns 0 on success, errno otherwise */ static int listen(struct socket *sock, int len) { /* REQUIRES SOCKET LOCKING OF SOME SORT? */ if (sock->state == SS_READY) return -EOPNOTSUPP; if (sock->state != SS_UNCONNECTED) return -EINVAL; sock->state = SS_LISTENING; return 0; } /** * accept - wait for connection request * @sock: listening socket * @newsock: new socket that is to be connected * @flags: file-related flags associated with socket * * Returns 0 on success, errno otherwise */ static int accept(struct socket *sock, struct socket *newsock, int flags) { struct tipc_sock *tsock = tipc_sk(sock->sk); struct sk_buff *buf; int res = -EFAULT; if (sock->state == SS_READY) return -EOPNOTSUPP; if (sock->state != SS_LISTENING) return -EINVAL; if (unlikely((skb_queue_len(&sock->sk->sk_receive_queue) == 0) && (flags & O_NONBLOCK))) return -EWOULDBLOCK; if (down_interruptible(&tsock->sem)) return -ERESTARTSYS; if (wait_event_interruptible(*sock->sk->sk_sleep, skb_queue_len(&sock->sk->sk_receive_queue))) { res = -ERESTARTSYS; goto exit; } buf = skb_peek(&sock->sk->sk_receive_queue); res = tipc_create(newsock, 0); if (!res) { struct tipc_sock *new_tsock = tipc_sk(newsock->sk); struct tipc_portid id; struct tipc_msg *msg = buf_msg(buf); u32 new_ref = new_tsock->p->ref; id.ref = msg_origport(msg); id.node = msg_orignode(msg); tipc_connect2port(new_ref, &id); newsock->state = SS_CONNECTED; tipc_set_portimportance(new_ref, msg_importance(msg)); if (msg_named(msg)) { new_tsock->p->conn_type = msg_nametype(msg); new_tsock->p->conn_instance = msg_nameinst(msg); } /* * Respond to 'SYN-' by discarding it & returning 'ACK'-. * Respond to 'SYN+' by queuing it on new socket. */ msg_dbg(msg,"<ACC<: "); if (!msg_data_sz(msg)) { struct msghdr m = {NULL,}; send_packet(NULL, newsock, &m, 0); advance_queue(tsock); } else { sock_lock(tsock); skb_dequeue(&sock->sk->sk_receive_queue); sock_unlock(tsock); skb_queue_head(&newsock->sk->sk_receive_queue, buf); } } exit: up(&tsock->sem); return res; } /** * shutdown - shutdown socket connection * @sock: socket structure * @how: direction to close (unused; always treated as read + write) * * Terminates connection (if necessary), then purges socket's receive queue. * * Returns 0 on success, errno otherwise */ static int shutdown(struct socket *sock, int how) { struct tipc_sock* tsock = tipc_sk(sock->sk); struct sk_buff *buf; int res; /* Could return -EINVAL for an invalid "how", but why bother? */ if (down_interruptible(&tsock->sem)) return -ERESTARTSYS; sock_lock(tsock); switch (sock->state) { case SS_CONNECTED: /* Send 'FIN+' or 'FIN-' message to peer */ sock_unlock(tsock); restart: if ((buf = skb_dequeue(&sock->sk->sk_receive_queue))) { atomic_dec(&tipc_queue_size); if (TIPC_SKB_CB(buf)->handle != msg_data(buf_msg(buf))) { buf_discard(buf); goto restart; } tipc_reject_msg(buf, TIPC_CONN_SHUTDOWN); } else { tipc_shutdown(tsock->p->ref); } sock_lock(tsock); /* fall through */ case SS_DISCONNECTING: /* Discard any unreceived messages */ while ((buf = skb_dequeue(&sock->sk->sk_receive_queue))) { atomic_dec(&tipc_queue_size); buf_discard(buf); } tsock->p->conn_unacked = 0; /* fall through */ case SS_CONNECTING: sock->state = SS_DISCONNECTING; res = 0; break; default: res = -ENOTCONN; } sock_unlock(tsock); up(&tsock->sem); return res; } /** * setsockopt - set socket option * @sock: socket structure * @lvl: option level * @opt: option identifier * @ov: pointer to new option value * @ol: length of option value * * For stream sockets only, accepts and ignores all IPPROTO_TCP options * (to ease compatibility). * * Returns 0 on success, errno otherwise */ static int setsockopt(struct socket *sock, int lvl, int opt, char __user *ov, int ol) { struct tipc_sock *tsock = tipc_sk(sock->sk); u32 value; int res; if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM)) return 0; if (lvl != SOL_TIPC) return -ENOPROTOOPT; if (ol < sizeof(value)) return -EINVAL; if ((res = get_user(value, (u32 *)ov))) return res; if (down_interruptible(&tsock->sem)) return -ERESTARTSYS; switch (opt) { case TIPC_IMPORTANCE: res = tipc_set_portimportance(tsock->p->ref, value); break; case TIPC_SRC_DROPPABLE: if (sock->type != SOCK_STREAM) res = tipc_set_portunreliable(tsock->p->ref, value); else res = -ENOPROTOOPT; break; case TIPC_DEST_DROPPABLE: res = tipc_set_portunreturnable(tsock->p->ref, value); break; case TIPC_CONN_TIMEOUT: sock->sk->sk_rcvtimeo = (value * HZ / 1000); break; default: res = -EINVAL; } up(&tsock->sem); return res; } /** * getsockopt - get socket option * @sock: socket structure * @lvl: option level * @opt: option identifier * @ov: receptacle for option value * @ol: receptacle for length of option value * * For stream sockets only, returns 0 length result for all IPPROTO_TCP options * (to ease compatibility). * * Returns 0 on success, errno otherwise */ static int getsockopt(struct socket *sock, int lvl, int opt, char __user *ov, int *ol) { struct tipc_sock *tsock = tipc_sk(sock->sk); int len; u32 value; int res; if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM)) return put_user(0, ol); if (lvl != SOL_TIPC) return -ENOPROTOOPT; if ((res = get_user(len, ol))) return res; if (down_interruptible(&tsock->sem)) return -ERESTARTSYS; switch (opt) { case TIPC_IMPORTANCE: res = tipc_portimportance(tsock->p->ref, &value); break; case TIPC_SRC_DROPPABLE: res = tipc_portunreliable(tsock->p->ref, &value); break; case TIPC_DEST_DROPPABLE: res = tipc_portunreturnable(tsock->p->ref, &value); break; case TIPC_CONN_TIMEOUT: value = (sock->sk->sk_rcvtimeo * 1000) / HZ; break; default: res = -EINVAL; } if (res) { /* "get" failed */ } else if (len < sizeof(value)) { res = -EINVAL; } else if ((res = copy_to_user(ov, &value, sizeof(value)))) { /* couldn't return value */ } else { res = put_user(sizeof(value), ol); } up(&tsock->sem); return res; } /** * Placeholders for non-implemented functionality * * Returns error code (POSIX-compliant where defined) */ static int ioctl(struct socket *s, u32 cmd, unsigned long arg) { return -EINVAL; } static int no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma) { return -EINVAL; } static ssize_t no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags) { return -EINVAL; } static int no_skpair(struct socket *s1, struct socket *s2) { return -EOPNOTSUPP; } /** * Protocol switches for the various types of TIPC sockets */ static struct proto_ops msg_ops = { .owner = THIS_MODULE, .family = AF_TIPC, .release = release, .bind = bind, .connect = connect, .socketpair = no_skpair, .accept = accept, .getname = get_name, .poll = poll, .ioctl = ioctl, .listen = listen, .shutdown = shutdown, .setsockopt = setsockopt, .getsockopt = getsockopt, .sendmsg = send_msg, .recvmsg = recv_msg, .mmap = no_mmap, .sendpage = no_sendpage }; static struct proto_ops packet_ops = { .owner = THIS_MODULE, .family = AF_TIPC, .release = release, .bind = bind, .connect = connect, .socketpair = no_skpair, .accept = accept, .getname = get_name, .poll = poll, .ioctl = ioctl, .listen = listen, .shutdown = shutdown, .setsockopt = setsockopt, .getsockopt = getsockopt, .sendmsg = send_packet, .recvmsg = recv_msg, .mmap = no_mmap, .sendpage = no_sendpage }; static struct proto_ops stream_ops = { .owner = THIS_MODULE, .family = AF_TIPC, .release = release, .bind = bind, .connect = connect, .socketpair = no_skpair, .accept = accept, .getname = get_name, .poll = poll, .ioctl = ioctl, .listen = listen, .shutdown = shutdown, .setsockopt = setsockopt, .getsockopt = getsockopt, .sendmsg = send_stream, .recvmsg = recv_stream, .mmap = no_mmap, .sendpage = no_sendpage }; static struct net_proto_family tipc_family_ops = { .owner = THIS_MODULE, .family = AF_TIPC, .create = tipc_create }; static struct proto tipc_proto = { .name = "TIPC", .owner = THIS_MODULE, .obj_size = sizeof(struct tipc_sock) }; /** * tipc_socket_init - initialize TIPC socket interface * * Returns 0 on success, errno otherwise */ int tipc_socket_init(void) { int res; res = proto_register(&tipc_proto, 1); if (res) { err("Failed to register TIPC protocol type\n"); goto out; } res = sock_register(&tipc_family_ops); if (res) { err("Failed to register TIPC socket type\n"); proto_unregister(&tipc_proto); goto out; } sockets_enabled = 1; out: return res; } /** * tipc_socket_stop - stop TIPC socket interface */ void tipc_socket_stop(void) { if (!sockets_enabled) return; sockets_enabled = 0; sock_unregister(tipc_family_ops.family); proto_unregister(&tipc_proto); }