/* * net/tipc/socket.c: TIPC socket API * * Copyright (c) 2001-2007, Ericsson AB * Copyright (c) 2004-2008, 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "core.h" #define SS_LISTENING -1 /* socket is listening */ #define SS_READY -2 /* socket is connectionless */ #define OVERLOAD_LIMIT_BASE 5000 #define CONN_TIMEOUT_DEFAULT 8000 /* default connect timeout = 8s */ struct tipc_sock { struct sock sk; struct tipc_port *p; struct tipc_portid peer_name; }; #define tipc_sk(sk) ((struct tipc_sock *)(sk)) #define tipc_sk_port(sk) ((struct tipc_port *)(tipc_sk(sk)->p)) static int backlog_rcv(struct sock *sk, struct sk_buff *skb); static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf); static void wakeupdispatch(struct tipc_port *tport); static const struct proto_ops packet_ops; static const struct proto_ops stream_ops; static const struct proto_ops msg_ops; static struct proto tipc_proto; static int sockets_enabled = 0; static atomic_t tipc_queue_size = ATOMIC_INIT(0); /* * Revised TIPC socket locking policy: * * Most socket operations take the standard socket lock when they start * and hold it until they finish (or until they need to sleep). Acquiring * this lock grants the owner exclusive access to the fields of the socket * data structures, with the exception of the backlog queue. A few socket * operations can be done without taking the socket lock because they only * read socket information that never changes during the life of the socket. * * Socket operations may acquire the lock for the associated TIPC port if they * need to perform an operation on the port. If any routine needs to acquire * both the socket lock and the port lock it must take the socket lock first * to avoid the risk of deadlock. * * The dispatcher handling incoming messages cannot grab the socket lock in * the standard fashion, since invoked it runs at the BH level and cannot block. * Instead, it checks to see if the socket lock is currently owned by someone, * and either handles the message itself or adds it to the socket's backlog * queue; in the latter case the queued message is processed once the process * owning the socket lock releases it. * * NOTE: Releasing the socket lock while an operation is sleeping overcomes * the problem of a blocked socket operation preventing any other operations * from occurring. However, applications must be careful if they have * multiple threads trying to send (or receive) on the same socket, as these * operations might interfere with each other. For example, doing a connect * and a receive at the same time might allow the receive to consume the * ACK message meant for the connect. While additional work could be done * to try and overcome this, it doesn't seem to be worthwhile at the present. * * NOTE: Releasing the socket lock while an operation is sleeping also ensures * that another operation that must be performed in a non-blocking manner is * not delayed for very long because the lock has already been taken. * * NOTE: This code assumes that certain fields of a port/socket pair are * constant over its lifetime; such fields can be examined without taking * the socket lock and/or port lock, and do not need to be re-read even * after resuming processing after waiting. These fields include: * - socket type * - pointer to socket sk structure (aka tipc_sock structure) * - pointer to port structure * - port reference */ /** * advance_rx_queue - discard first buffer in socket receive queue * * Caller must hold socket lock */ static void advance_rx_queue(struct sock *sk) { buf_discard(__skb_dequeue(&sk->sk_receive_queue)); atomic_dec(&tipc_queue_size); } /** * discard_rx_queue - discard all buffers in socket receive queue * * Caller must hold socket lock */ static void discard_rx_queue(struct sock *sk) { struct sk_buff *buf; while ((buf = __skb_dequeue(&sk->sk_receive_queue))) { atomic_dec(&tipc_queue_size); buf_discard(buf); } } /** * reject_rx_queue - reject all buffers in socket receive queue * * Caller must hold socket lock */ static void reject_rx_queue(struct sock *sk) { struct sk_buff *buf; while ((buf = __skb_dequeue(&sk->sk_receive_queue))) { tipc_reject_msg(buf, TIPC_ERR_NO_PORT); atomic_dec(&tipc_queue_size); } } /** * tipc_create - create a TIPC socket * @net: network namespace (must be default network) * @sock: pre-allocated socket structure * @protocol: protocol indicator (must be 0) * @kern: caused by kernel or by userspace? * * This routine creates additional data structures used by the TIPC socket, * initializes them, and links them together. * * Returns 0 on success, errno otherwise */ static int tipc_create(struct net *net, struct socket *sock, int protocol, int kern) { const struct proto_ops *ops; socket_state state; struct sock *sk; struct tipc_port *tp_ptr; /* Validate arguments */ if (!net_eq(net, &init_net)) return -EAFNOSUPPORT; if (unlikely(protocol != 0)) return -EPROTONOSUPPORT; switch (sock->type) { case SOCK_STREAM: ops = &stream_ops; state = SS_UNCONNECTED; break; case SOCK_SEQPACKET: ops = &packet_ops; state = SS_UNCONNECTED; break; case SOCK_DGRAM: case SOCK_RDM: ops = &msg_ops; state = SS_READY; break; default: return -EPROTOTYPE; } /* Allocate socket's protocol area */ sk = sk_alloc(net, AF_TIPC, GFP_KERNEL, &tipc_proto); if (sk == NULL) return -ENOMEM; /* Allocate TIPC port for socket to use */ tp_ptr = tipc_createport_raw(sk, &dispatch, &wakeupdispatch, TIPC_LOW_IMPORTANCE); if (unlikely(!tp_ptr)) { sk_free(sk); return -ENOMEM; } /* Finish initializing socket data structures */ sock->ops = ops; sock->state = state; sock_init_data(sock, sk); sk->sk_rcvtimeo = msecs_to_jiffies(CONN_TIMEOUT_DEFAULT); sk->sk_backlog_rcv = backlog_rcv; tipc_sk(sk)->p = tp_ptr; spin_unlock_bh(tp_ptr->lock); if (sock->state == SS_READY) { tipc_set_portunreturnable(tp_ptr->ref, 1); if (sock->type == SOCK_DGRAM) tipc_set_portunreliable(tp_ptr->ref, 1); } 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 sock *sk = sock->sk; struct tipc_port *tport; struct sk_buff *buf; int res; /* * Exit if socket isn't fully initialized (occurs when a failed accept() * releases a pre-allocated child socket that was never used) */ if (sk == NULL) return 0; tport = tipc_sk_port(sk); lock_sock(sk); /* * Reject all unreceived messages, except on an active connection * (which disconnects locally & sends a 'FIN+' to peer) */ while (sock->state != SS_DISCONNECTING) { buf = __skb_dequeue(&sk->sk_receive_queue); if (buf == NULL) break; atomic_dec(&tipc_queue_size); if (TIPC_SKB_CB(buf)->handle != msg_data(buf_msg(buf))) buf_discard(buf); else { if ((sock->state == SS_CONNECTING) || (sock->state == SS_CONNECTED)) { sock->state = SS_DISCONNECTING; tipc_disconnect(tport->ref); } tipc_reject_msg(buf, TIPC_ERR_NO_PORT); } } /* * Delete TIPC port; this ensures no more messages are queued * (also disconnects an active connection & sends a 'FIN-' to peer) */ res = tipc_deleteport(tport->ref); /* Discard any remaining (connection-based) messages in receive queue */ discard_rx_queue(sk); /* Reject any messages that accumulated in backlog queue */ sock->state = SS_DISCONNECTING; release_sock(sk); sock_put(sk); sock->sk = NULL; 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 * * NOTE: This routine doesn't need to take the socket lock since it doesn't * access any non-constant socket information. */ static int bind(struct socket *sock, struct sockaddr *uaddr, int uaddr_len) { struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr; u32 portref = tipc_sk_port(sock->sk)->ref; if (unlikely(!uaddr_len)) return tipc_withdraw(portref, 0, NULL); if (uaddr_len < sizeof(struct sockaddr_tipc)) return -EINVAL; if (addr->family != AF_TIPC) return -EAFNOSUPPORT; if (addr->addrtype == TIPC_ADDR_NAME) addr->addr.nameseq.upper = addr->addr.nameseq.lower; else if (addr->addrtype != TIPC_ADDR_NAMESEQ) return -EAFNOSUPPORT; return (addr->scope > 0) ? tipc_publish(portref, addr->scope, &addr->addr.nameseq) : tipc_withdraw(portref, -addr->scope, &addr->addr.nameseq); } /** * 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 = own ID, 1 = current peer ID, 2 = current/former peer ID * * Returns 0 on success, errno otherwise * * NOTE: This routine doesn't need to take the socket lock since it only * accesses socket information that is unchanging (or which changes in * a completely predictable manner). */ static int get_name(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) { struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr; struct tipc_sock *tsock = tipc_sk(sock->sk); if (peer) { if ((sock->state != SS_CONNECTED) && ((peer != 2) || (sock->state != SS_DISCONNECTING))) return -ENOTCONN; addr->addr.id.ref = tsock->peer_name.ref; addr->addr.id.node = tsock->peer_name.node; } else { tipc_ownidentity(tsock->p->ref, &addr->addr.id); } *uaddr_len = sizeof(*addr); addr->addrtype = TIPC_ADDR_ID; addr->family = AF_TIPC; addr->scope = 0; addr->addr.name.domain = 0; return 0; } /** * 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 pollmask value * * COMMENTARY: * It appears that the usual socket locking mechanisms are not useful here * since the pollmask info is potentially out-of-date the moment this routine * exits. TCP and other protocols seem to rely on higher level poll routines * to handle any preventable race conditions, so TIPC will do the same ... * * 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! */ static unsigned int poll(struct file *file, struct socket *sock, poll_table *wait) { struct sock *sk = sock->sk; u32 mask; poll_wait(file, sk->sk_sleep, wait); if (!skb_queue_empty(&sk->sk_receive_queue) || (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; } /** * 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: if NULL, indicates that socket lock is already held * @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 sock *sk = sock->sk; struct tipc_port *tport = tipc_sk_port(sk); struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name; int needs_conn; int res = -EINVAL; if (unlikely(!dest)) return -EDESTADDRREQ; if (unlikely((m->msg_namelen < sizeof(*dest)) || (dest->family != AF_TIPC))) return -EINVAL; if (iocb) lock_sock(sk); needs_conn = (sock->state != SS_READY); if (unlikely(needs_conn)) { if (sock->state == SS_LISTENING) { res = -EPIPE; goto exit; } if (sock->state != SS_UNCONNECTED) { res = -EISCONN; goto exit; } if ((tport->published) || ((sock->type == SOCK_STREAM) && (total_len != 0))) { res = -EOPNOTSUPP; goto exit; } if (dest->addrtype == TIPC_ADDR_NAME) { tport->conn_type = dest->addr.name.name.type; tport->conn_instance = dest->addr.name.name.instance; } /* Abort any pending connection attempts (very unlikely) */ reject_rx_queue(sk); } do { if (dest->addrtype == TIPC_ADDR_NAME) { if ((res = dest_name_check(dest, m))) break; res = tipc_send2name(tport->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(tport->ref, &dest->addr.id, m->msg_iovlen, m->msg_iov); } else if (dest->addrtype == TIPC_ADDR_MCAST) { if (needs_conn) { res = -EOPNOTSUPP; break; } if ((res = dest_name_check(dest, m))) break; res = tipc_multicast(tport->ref, &dest->addr.nameseq, 0, m->msg_iovlen, m->msg_iov); } if (likely(res != -ELINKCONG)) { if (needs_conn && (res >= 0)) { sock->state = SS_CONNECTING; } break; } if (m->msg_flags & MSG_DONTWAIT) { res = -EWOULDBLOCK; break; } release_sock(sk); res = wait_event_interruptible(*sk->sk_sleep, !tport->congested); lock_sock(sk); if (res) break; } while (1); exit: if (iocb) release_sock(sk); return res; } /** * send_packet - send a connection-oriented message * @iocb: if NULL, indicates that socket lock is already held * @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 sock *sk = sock->sk; struct tipc_port *tport = tipc_sk_port(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 (iocb) lock_sock(sk); do { if (unlikely(sock->state != SS_CONNECTED)) { if (sock->state == SS_DISCONNECTING) res = -EPIPE; else res = -ENOTCONN; break; } res = tipc_send(tport->ref, m->msg_iovlen, m->msg_iov); if (likely(res != -ELINKCONG)) { break; } if (m->msg_flags & MSG_DONTWAIT) { res = -EWOULDBLOCK; break; } release_sock(sk); res = wait_event_interruptible(*sk->sk_sleep, (!tport->congested || !tport->connected)); lock_sock(sk); if (res) break; } while (1); if (iocb) release_sock(sk); return res; } /** * 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 sock *sk = sock->sk; struct tipc_port *tport = tipc_sk_port(sk); struct msghdr my_msg; struct iovec my_iov; struct iovec *curr_iov; int curr_iovlen; char __user *curr_start; u32 hdr_size; int curr_left; int bytes_to_send; int bytes_sent; int res; lock_sock(sk); /* Handle special cases where there is no connection */ if (unlikely(sock->state != SS_CONNECTED)) { if (sock->state == SS_UNCONNECTED) { res = send_packet(NULL, sock, m, total_len); goto exit; } else if (sock->state == SS_DISCONNECTING) { res = -EPIPE; goto exit; } else { res = -ENOTCONN; goto exit; } } if (unlikely(m->msg_name)) { res = -EISCONN; goto exit; } /* * 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; my_msg.msg_flags = m->msg_flags; my_msg.msg_name = NULL; bytes_sent = 0; hdr_size = msg_hdr_sz(&tport->phdr); while (curr_iovlen--) { curr_start = curr_iov->iov_base; curr_left = curr_iov->iov_len; while (curr_left) { bytes_to_send = tport->max_pkt - hdr_size; if (bytes_to_send > TIPC_MAX_USER_MSG_SIZE) bytes_to_send = TIPC_MAX_USER_MSG_SIZE; if (curr_left < bytes_to_send) bytes_to_send = curr_left; my_iov.iov_base = curr_start; my_iov.iov_len = bytes_to_send; if ((res = send_packet(NULL, sock, &my_msg, 0)) < 0) { if (bytes_sent) res = bytes_sent; goto exit; } curr_left -= bytes_to_send; curr_start += bytes_to_send; bytes_sent += bytes_to_send; } curr_iov++; } res = bytes_sent; exit: release_sock(sk); return res; } /** * auto_connect - complete connection setup to a remote port * @sock: socket structure * @msg: peer's response message * * Returns 0 on success, errno otherwise */ static int auto_connect(struct socket *sock, struct tipc_msg *msg) { struct tipc_sock *tsock = tipc_sk(sock->sk); if (msg_errcode(msg)) { sock->state = SS_DISCONNECTING; return -ECONNREFUSED; } tsock->peer_name.ref = msg_origport(msg); tsock->peer_name.node = msg_orignode(msg); tipc_connect2port(tsock->p->ref, &tsock->peer_name); 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 sock *sk = sock->sk; struct tipc_port *tport = tipc_sk_port(sk); struct sk_buff *buf; struct tipc_msg *msg; unsigned int sz; u32 err; int res; /* Catch invalid receive requests */ if (m->msg_iovlen != 1) return -EOPNOTSUPP; /* Don't do multiple iovec entries yet */ if (unlikely(!buf_len)) return -EINVAL; lock_sock(sk); if (unlikely(sock->state == SS_UNCONNECTED)) { res = -ENOTCONN; goto exit; } restart: /* Look for a message in receive queue; wait if necessary */ while (skb_queue_empty(&sk->sk_receive_queue)) { if (sock->state == SS_DISCONNECTING) { res = -ENOTCONN; goto exit; } if (flags & MSG_DONTWAIT) { res = -EWOULDBLOCK; goto exit; } release_sock(sk); res = wait_event_interruptible(*sk->sk_sleep, (!skb_queue_empty(&sk->sk_receive_queue) || (sock->state == SS_DISCONNECTING))); lock_sock(sk); if (res) goto exit; } /* Look at first message in receive queue */ buf = skb_peek(&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)) { res = auto_connect(sock, msg); if (res) goto exit; } /* Discard an empty non-errored message & try again */ if ((!sz) && (!err)) { advance_rx_queue(sk); goto restart; } /* Capture sender's address (optional) */ set_orig_addr(m, msg); /* Capture ancillary data (optional) */ res = anc_data_recv(m, msg, tport); if (res) 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 ((sock->state != SS_READY) && (++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN)) tipc_acknowledge(tport->ref, tport->conn_unacked); advance_rx_queue(sk); } exit: release_sock(sk); 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 sock *sk = sock->sk; struct tipc_port *tport = tipc_sk_port(sk); struct sk_buff *buf; struct tipc_msg *msg; unsigned int sz; int sz_to_copy; int sz_copied = 0; int needed; char __user *crs = m->msg_iov->iov_base; unsigned char *buf_crs; u32 err; int res = 0; /* Catch invalid receive attempts */ if (m->msg_iovlen != 1) return -EOPNOTSUPP; /* Don't do multiple iovec entries yet */ if (unlikely(!buf_len)) return -EINVAL; lock_sock(sk); if (unlikely((sock->state == SS_UNCONNECTED) || (sock->state == SS_CONNECTING))) { res = -ENOTCONN; goto exit; } restart: /* Look for a message in receive queue; wait if necessary */ while (skb_queue_empty(&sk->sk_receive_queue)) { if (sock->state == SS_DISCONNECTING) { res = -ENOTCONN; goto exit; } if (flags & MSG_DONTWAIT) { res = -EWOULDBLOCK; goto exit; } release_sock(sk); res = wait_event_interruptible(*sk->sk_sleep, (!skb_queue_empty(&sk->sk_receive_queue) || (sock->state == SS_DISCONNECTING))); lock_sock(sk); if (res) goto exit; } /* Look at first message in receive queue */ buf = skb_peek(&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_rx_queue(sk); goto restart; } /* Optionally capture sender's address & ancillary data of first msg */ if (sz_copied == 0) { set_orig_addr(m, msg); res = anc_data_recv(m, msg, tport); if (res) goto exit; } /* Capture message data (if valid) & compute return value (always) */ if (!err) { buf_crs = (unsigned char *)(TIPC_SKB_CB(buf)->handle); sz = (unsigned char *)msg + msg_size(msg) - 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(++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN)) tipc_acknowledge(tport->ref, tport->conn_unacked); advance_rx_queue(sk); } /* Loop around if more data is required */ if ((sz_copied < buf_len) && /* didn't get all requested data */ (!skb_queue_empty(&sk->sk_receive_queue) || (flags & MSG_WAITALL)) && /* and more is ready or required */ (!(flags & MSG_PEEK)) && /* and aren't just peeking at data */ (!err)) /* and haven't reached a FIN */ goto restart; exit: release_sock(sk); return sz_copied ? sz_copied : res; } /** * rx_queue_full - determine if receive queue can accept another message * @msg: message to be added to queue * @queue_size: current size of queue * @base: nominal maximum size of queue * * Returns 1 if queue is unable to accept message, 0 otherwise */ static int rx_queue_full(struct tipc_msg *msg, u32 queue_size, u32 base) { 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); } /** * filter_rcv - validate incoming message * @sk: socket * @buf: message * * Enqueues message on receive queue if acceptable; optionally handles * disconnect indication for a connected socket. * * Called with socket lock already taken; port lock may also be taken. * * Returns TIPC error status code (TIPC_OK if message is not to be rejected) */ static u32 filter_rcv(struct sock *sk, struct sk_buff *buf) { struct socket *sock = sk->sk_socket; struct tipc_msg *msg = buf_msg(buf); u32 recv_q_len; /* 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 */ 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 */ recv_q_len = (u32)atomic_read(&tipc_queue_size); if (unlikely(recv_q_len >= OVERLOAD_LIMIT_BASE)) { if (rx_queue_full(msg, recv_q_len, OVERLOAD_LIMIT_BASE)) return TIPC_ERR_OVERLOAD; } recv_q_len = skb_queue_len(&sk->sk_receive_queue); if (unlikely(recv_q_len >= (OVERLOAD_LIMIT_BASE / 2))) { if (rx_queue_full(msg, recv_q_len, OVERLOAD_LIMIT_BASE / 2)) return TIPC_ERR_OVERLOAD; } /* Enqueue message (finally!) */ msg_dbg(msg, "handle = msg_data(msg); atomic_inc(&tipc_queue_size); __skb_queue_tail(&sk->sk_receive_queue, buf); /* Initiate connection termination for an incoming 'FIN' */ if (unlikely(msg_errcode(msg) && (sock->state == SS_CONNECTED))) { sock->state = SS_DISCONNECTING; tipc_disconnect_port(tipc_sk_port(sk)); } if (waitqueue_active(sk->sk_sleep)) wake_up_interruptible(sk->sk_sleep); return TIPC_OK; } /** * backlog_rcv - handle incoming message from backlog queue * @sk: socket * @buf: message * * Caller must hold socket lock, but not port lock. * * Returns 0 */ static int backlog_rcv(struct sock *sk, struct sk_buff *buf) { u32 res; res = filter_rcv(sk, buf); if (res) tipc_reject_msg(buf, res); return 0; } /** * dispatch - handle incoming message * @tport: TIPC port that received message * @buf: message * * Called with port lock already taken. * * 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 sock *sk = (struct sock *)tport->usr_handle; u32 res; /* * Process message if socket is unlocked; otherwise add to backlog queue * * This code is based on sk_receive_skb(), but must be distinct from it * since a TIPC-specific filter/reject mechanism is utilized */ bh_lock_sock(sk); if (!sock_owned_by_user(sk)) { res = filter_rcv(sk, buf); } else { if (sk_add_backlog_limited(sk, buf)) res = TIPC_ERR_OVERLOAD; else res = TIPC_OK; } bh_unlock_sock(sk); return res; } /** * wakeupdispatch - wake up port after congestion * @tport: port to wakeup * * Called with port lock already taken. */ static void wakeupdispatch(struct tipc_port *tport) { struct sock *sk = (struct sock *)tport->usr_handle; if (waitqueue_active(sk->sk_sleep)) wake_up_interruptible(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: file-related flags associated with socket * * Returns 0 on success, errno otherwise */ static int connect(struct socket *sock, struct sockaddr *dest, int destlen, int flags) { struct sock *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; lock_sock(sk); /* For now, TIPC does not allow use of connect() with DGRAM/RDM types */ if (sock->state == SS_READY) { res = -EOPNOTSUPP; goto exit; } /* For now, TIPC does not support the non-blocking form of connect() */ if (flags & O_NONBLOCK) { res = -EWOULDBLOCK; goto exit; } /* Issue Posix-compliant error code if socket is in the wrong state */ if (sock->state == SS_LISTENING) { res = -EOPNOTSUPP; goto exit; } if (sock->state == SS_CONNECTING) { res = -EALREADY; goto exit; } if (sock->state != SS_UNCONNECTED) { res = -EISCONN; goto exit; } /* * 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) { res = -EINVAL; goto exit; } /* Reject any messages already in receive queue (very unlikely) */ reject_rx_queue(sk); /* Send a 'SYN-' to destination */ m.msg_name = dest; m.msg_namelen = destlen; res = send_msg(NULL, sock, &m, 0); if (res < 0) { goto exit; } /* Wait until an 'ACK' or 'RST' arrives, or a timeout occurs */ release_sock(sk); res = wait_event_interruptible_timeout(*sk->sk_sleep, (!skb_queue_empty(&sk->sk_receive_queue) || (sock->state != SS_CONNECTING)), sk->sk_rcvtimeo); lock_sock(sk); if (res > 0) { buf = skb_peek(&sk->sk_receive_queue); if (buf != NULL) { msg = buf_msg(buf); res = auto_connect(sock, msg); if (!res) { if (!msg_data_sz(msg)) advance_rx_queue(sk); } } else { if (sock->state == SS_CONNECTED) { res = -EISCONN; } else { res = -ECONNREFUSED; } } } else { if (res == 0) res = -ETIMEDOUT; else ; /* leave "res" unchanged */ sock->state = SS_DISCONNECTING; } exit: release_sock(sk); 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) { struct sock *sk = sock->sk; int res; lock_sock(sk); if (sock->state == SS_READY) res = -EOPNOTSUPP; else if (sock->state != SS_UNCONNECTED) res = -EINVAL; else { sock->state = SS_LISTENING; res = 0; } release_sock(sk); return res; } /** * 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 *new_sock, int flags) { struct sock *sk = sock->sk; struct sk_buff *buf; int res; lock_sock(sk); if (sock->state == SS_READY) { res = -EOPNOTSUPP; goto exit; } if (sock->state != SS_LISTENING) { res = -EINVAL; goto exit; } while (skb_queue_empty(&sk->sk_receive_queue)) { if (flags & O_NONBLOCK) { res = -EWOULDBLOCK; goto exit; } release_sock(sk); res = wait_event_interruptible(*sk->sk_sleep, (!skb_queue_empty(&sk->sk_receive_queue))); lock_sock(sk); if (res) goto exit; } buf = skb_peek(&sk->sk_receive_queue); res = tipc_create(sock_net(sock->sk), new_sock, 0, 0); if (!res) { struct sock *new_sk = new_sock->sk; struct tipc_sock *new_tsock = tipc_sk(new_sk); struct tipc_port *new_tport = new_tsock->p; u32 new_ref = new_tport->ref; struct tipc_msg *msg = buf_msg(buf); lock_sock(new_sk); /* * Reject any stray messages received by new socket * before the socket lock was taken (very, very unlikely) */ reject_rx_queue(new_sk); /* Connect new socket to it's peer */ new_tsock->peer_name.ref = msg_origport(msg); new_tsock->peer_name.node = msg_orignode(msg); tipc_connect2port(new_ref, &new_tsock->peer_name); new_sock->state = SS_CONNECTED; tipc_set_portimportance(new_ref, msg_importance(msg)); if (msg_named(msg)) { new_tport->conn_type = msg_nametype(msg); new_tport->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,"sk_receive_queue); __skb_queue_head(&new_sk->sk_receive_queue, buf); } release_sock(new_sk); } exit: release_sock(sk); return res; } /** * shutdown - shutdown socket connection * @sock: socket structure * @how: direction to close (must be SHUT_RDWR) * * 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 sock *sk = sock->sk; struct tipc_port *tport = tipc_sk_port(sk); struct sk_buff *buf; int res; if (how != SHUT_RDWR) return -EINVAL; lock_sock(sk); switch (sock->state) { case SS_CONNECTING: case SS_CONNECTED: /* Disconnect and send a 'FIN+' or 'FIN-' message to peer */ restart: buf = __skb_dequeue(&sk->sk_receive_queue); if (buf) { atomic_dec(&tipc_queue_size); if (TIPC_SKB_CB(buf)->handle != msg_data(buf_msg(buf))) { buf_discard(buf); goto restart; } tipc_disconnect(tport->ref); tipc_reject_msg(buf, TIPC_CONN_SHUTDOWN); } else { tipc_shutdown(tport->ref); } sock->state = SS_DISCONNECTING; /* fall through */ case SS_DISCONNECTING: /* Discard any unreceived messages; wake up sleeping tasks */ discard_rx_queue(sk); if (waitqueue_active(sk->sk_sleep)) wake_up_interruptible(sk->sk_sleep); res = 0; break; default: res = -ENOTCONN; } release_sock(sk); 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, unsigned int ol) { struct sock *sk = sock->sk; struct tipc_port *tport = tipc_sk_port(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 __user *)ov))) return res; lock_sock(sk); switch (opt) { case TIPC_IMPORTANCE: res = tipc_set_portimportance(tport->ref, value); break; case TIPC_SRC_DROPPABLE: if (sock->type != SOCK_STREAM) res = tipc_set_portunreliable(tport->ref, value); else res = -ENOPROTOOPT; break; case TIPC_DEST_DROPPABLE: res = tipc_set_portunreturnable(tport->ref, value); break; case TIPC_CONN_TIMEOUT: sk->sk_rcvtimeo = msecs_to_jiffies(value); /* no need to set "res", since already 0 at this point */ break; default: res = -EINVAL; } release_sock(sk); 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 __user *ol) { struct sock *sk = sock->sk; struct tipc_port *tport = tipc_sk_port(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; lock_sock(sk); switch (opt) { case TIPC_IMPORTANCE: res = tipc_portimportance(tport->ref, &value); break; case TIPC_SRC_DROPPABLE: res = tipc_portunreliable(tport->ref, &value); break; case TIPC_DEST_DROPPABLE: res = tipc_portunreturnable(tport->ref, &value); break; case TIPC_CONN_TIMEOUT: value = jiffies_to_msecs(sk->sk_rcvtimeo); /* no need to set "res", since already 0 at this point */ break; case TIPC_NODE_RECVQ_DEPTH: value = (u32)atomic_read(&tipc_queue_size); break; case TIPC_SOCK_RECVQ_DEPTH: value = skb_queue_len(&sk->sk_receive_queue); break; default: res = -EINVAL; } release_sock(sk); if (res) { /* "get" failed */ } else if (len < sizeof(value)) { res = -EINVAL; } else if (copy_to_user(ov, &value, sizeof(value))) { res = -EFAULT; } else { res = put_user(sizeof(value), ol); } return res; } /** * Protocol switches for the various types of TIPC sockets */ static const struct proto_ops msg_ops = { .owner = THIS_MODULE, .family = AF_TIPC, .release = release, .bind = bind, .connect = connect, .socketpair = sock_no_socketpair, .accept = accept, .getname = get_name, .poll = poll, .ioctl = sock_no_ioctl, .listen = listen, .shutdown = shutdown, .setsockopt = setsockopt, .getsockopt = getsockopt, .sendmsg = send_msg, .recvmsg = recv_msg, .mmap = sock_no_mmap, .sendpage = sock_no_sendpage }; static const struct proto_ops packet_ops = { .owner = THIS_MODULE, .family = AF_TIPC, .release = release, .bind = bind, .connect = connect, .socketpair = sock_no_socketpair, .accept = accept, .getname = get_name, .poll = poll, .ioctl = sock_no_ioctl, .listen = listen, .shutdown = shutdown, .setsockopt = setsockopt, .getsockopt = getsockopt, .sendmsg = send_packet, .recvmsg = recv_msg, .mmap = sock_no_mmap, .sendpage = sock_no_sendpage }; static const struct proto_ops stream_ops = { .owner = THIS_MODULE, .family = AF_TIPC, .release = release, .bind = bind, .connect = connect, .socketpair = sock_no_socketpair, .accept = accept, .getname = get_name, .poll = poll, .ioctl = sock_no_ioctl, .listen = listen, .shutdown = shutdown, .setsockopt = setsockopt, .getsockopt = getsockopt, .sendmsg = send_stream, .recvmsg = recv_stream, .mmap = sock_no_mmap, .sendpage = sock_no_sendpage }; static const 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); }