| /* |
| * NET4: Implementation of BSD Unix domain sockets. |
| * |
| * Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk> |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Fixes: |
| * Linus Torvalds : Assorted bug cures. |
| * Niibe Yutaka : async I/O support. |
| * Carsten Paeth : PF_UNIX check, address fixes. |
| * Alan Cox : Limit size of allocated blocks. |
| * Alan Cox : Fixed the stupid socketpair bug. |
| * Alan Cox : BSD compatibility fine tuning. |
| * Alan Cox : Fixed a bug in connect when interrupted. |
| * Alan Cox : Sorted out a proper draft version of |
| * file descriptor passing hacked up from |
| * Mike Shaver's work. |
| * Marty Leisner : Fixes to fd passing |
| * Nick Nevin : recvmsg bugfix. |
| * Alan Cox : Started proper garbage collector |
| * Heiko EiBfeldt : Missing verify_area check |
| * Alan Cox : Started POSIXisms |
| * Andreas Schwab : Replace inode by dentry for proper |
| * reference counting |
| * Kirk Petersen : Made this a module |
| * Christoph Rohland : Elegant non-blocking accept/connect algorithm. |
| * Lots of bug fixes. |
| * Alexey Kuznetosv : Repaired (I hope) bugs introduces |
| * by above two patches. |
| * Andrea Arcangeli : If possible we block in connect(2) |
| * if the max backlog of the listen socket |
| * is been reached. This won't break |
| * old apps and it will avoid huge amount |
| * of socks hashed (this for unix_gc() |
| * performances reasons). |
| * Security fix that limits the max |
| * number of socks to 2*max_files and |
| * the number of skb queueable in the |
| * dgram receiver. |
| * Artur Skawina : Hash function optimizations |
| * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8) |
| * Malcolm Beattie : Set peercred for socketpair |
| * Michal Ostrowski : Module initialization cleanup. |
| * Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT, |
| * the core infrastructure is doing that |
| * for all net proto families now (2.5.69+) |
| * |
| * |
| * Known differences from reference BSD that was tested: |
| * |
| * [TO FIX] |
| * ECONNREFUSED is not returned from one end of a connected() socket to the |
| * other the moment one end closes. |
| * fstat() doesn't return st_dev=0, and give the blksize as high water mark |
| * and a fake inode identifier (nor the BSD first socket fstat twice bug). |
| * [NOT TO FIX] |
| * accept() returns a path name even if the connecting socket has closed |
| * in the meantime (BSD loses the path and gives up). |
| * accept() returns 0 length path for an unbound connector. BSD returns 16 |
| * and a null first byte in the path (but not for gethost/peername - BSD bug ??) |
| * socketpair(...SOCK_RAW..) doesn't panic the kernel. |
| * BSD af_unix apparently has connect forgetting to block properly. |
| * (need to check this with the POSIX spec in detail) |
| * |
| * Differences from 2.0.0-11-... (ANK) |
| * Bug fixes and improvements. |
| * - client shutdown killed server socket. |
| * - removed all useless cli/sti pairs. |
| * |
| * Semantic changes/extensions. |
| * - generic control message passing. |
| * - SCM_CREDENTIALS control message. |
| * - "Abstract" (not FS based) socket bindings. |
| * Abstract names are sequences of bytes (not zero terminated) |
| * started by 0, so that this name space does not intersect |
| * with BSD names. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/signal.h> |
| #include <linux/sched.h> |
| #include <linux/errno.h> |
| #include <linux/string.h> |
| #include <linux/stat.h> |
| #include <linux/dcache.h> |
| #include <linux/namei.h> |
| #include <linux/socket.h> |
| #include <linux/un.h> |
| #include <linux/fcntl.h> |
| #include <linux/termios.h> |
| #include <linux/sockios.h> |
| #include <linux/net.h> |
| #include <linux/in.h> |
| #include <linux/fs.h> |
| #include <linux/slab.h> |
| #include <asm/uaccess.h> |
| #include <linux/skbuff.h> |
| #include <linux/netdevice.h> |
| #include <net/net_namespace.h> |
| #include <net/sock.h> |
| #include <net/tcp_states.h> |
| #include <net/af_unix.h> |
| #include <linux/proc_fs.h> |
| #include <linux/seq_file.h> |
| #include <net/scm.h> |
| #include <linux/init.h> |
| #include <linux/poll.h> |
| #include <linux/rtnetlink.h> |
| #include <linux/mount.h> |
| #include <net/checksum.h> |
| #include <linux/security.h> |
| #include <linux/freezer.h> |
| |
| struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1]; |
| EXPORT_SYMBOL_GPL(unix_socket_table); |
| DEFINE_SPINLOCK(unix_table_lock); |
| EXPORT_SYMBOL_GPL(unix_table_lock); |
| static atomic_long_t unix_nr_socks; |
| |
| #define unix_sockets_unbound (&unix_socket_table[UNIX_HASH_SIZE]) |
| |
| #define UNIX_ABSTRACT(sk) (unix_sk(sk)->addr->hash != UNIX_HASH_SIZE) |
| |
| #ifdef CONFIG_SECURITY_NETWORK |
| static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
| { |
| memcpy(UNIXSID(skb), &scm->secid, sizeof(u32)); |
| } |
| |
| static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
| { |
| scm->secid = *UNIXSID(skb); |
| } |
| #else |
| static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
| { } |
| |
| static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb) |
| { } |
| #endif /* CONFIG_SECURITY_NETWORK */ |
| |
| /* |
| * SMP locking strategy: |
| * hash table is protected with spinlock unix_table_lock |
| * each socket state is protected by separate spin lock. |
| */ |
| |
| static inline unsigned unix_hash_fold(__wsum n) |
| { |
| unsigned hash = (__force unsigned)n; |
| hash ^= hash>>16; |
| hash ^= hash>>8; |
| return hash&(UNIX_HASH_SIZE-1); |
| } |
| |
| #define unix_peer(sk) (unix_sk(sk)->peer) |
| |
| static inline int unix_our_peer(struct sock *sk, struct sock *osk) |
| { |
| return unix_peer(osk) == sk; |
| } |
| |
| static inline int unix_may_send(struct sock *sk, struct sock *osk) |
| { |
| return unix_peer(osk) == NULL || unix_our_peer(sk, osk); |
| } |
| |
| static inline int unix_recvq_full(struct sock const *sk) |
| { |
| return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog; |
| } |
| |
| struct sock *unix_peer_get(struct sock *s) |
| { |
| struct sock *peer; |
| |
| unix_state_lock(s); |
| peer = unix_peer(s); |
| if (peer) |
| sock_hold(peer); |
| unix_state_unlock(s); |
| return peer; |
| } |
| EXPORT_SYMBOL_GPL(unix_peer_get); |
| |
| static inline void unix_release_addr(struct unix_address *addr) |
| { |
| if (atomic_dec_and_test(&addr->refcnt)) |
| kfree(addr); |
| } |
| |
| /* |
| * Check unix socket name: |
| * - should be not zero length. |
| * - if started by not zero, should be NULL terminated (FS object) |
| * - if started by zero, it is abstract name. |
| */ |
| |
| static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned *hashp) |
| { |
| if (len <= sizeof(short) || len > sizeof(*sunaddr)) |
| return -EINVAL; |
| if (!sunaddr || sunaddr->sun_family != AF_UNIX) |
| return -EINVAL; |
| if (sunaddr->sun_path[0]) { |
| /* |
| * This may look like an off by one error but it is a bit more |
| * subtle. 108 is the longest valid AF_UNIX path for a binding. |
| * sun_path[108] doesn't as such exist. However in kernel space |
| * we are guaranteed that it is a valid memory location in our |
| * kernel address buffer. |
| */ |
| ((char *)sunaddr)[len] = 0; |
| len = strlen(sunaddr->sun_path)+1+sizeof(short); |
| return len; |
| } |
| |
| *hashp = unix_hash_fold(csum_partial(sunaddr, len, 0)); |
| return len; |
| } |
| |
| static void __unix_remove_socket(struct sock *sk) |
| { |
| sk_del_node_init(sk); |
| } |
| |
| static void __unix_insert_socket(struct hlist_head *list, struct sock *sk) |
| { |
| WARN_ON(!sk_unhashed(sk)); |
| sk_add_node(sk, list); |
| } |
| |
| static inline void unix_remove_socket(struct sock *sk) |
| { |
| spin_lock(&unix_table_lock); |
| __unix_remove_socket(sk); |
| spin_unlock(&unix_table_lock); |
| } |
| |
| static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk) |
| { |
| spin_lock(&unix_table_lock); |
| __unix_insert_socket(list, sk); |
| spin_unlock(&unix_table_lock); |
| } |
| |
| static struct sock *__unix_find_socket_byname(struct net *net, |
| struct sockaddr_un *sunname, |
| int len, int type, unsigned hash) |
| { |
| struct sock *s; |
| struct hlist_node *node; |
| |
| sk_for_each(s, node, &unix_socket_table[hash ^ type]) { |
| struct unix_sock *u = unix_sk(s); |
| |
| if (!net_eq(sock_net(s), net)) |
| continue; |
| |
| if (u->addr->len == len && |
| !memcmp(u->addr->name, sunname, len)) |
| goto found; |
| } |
| s = NULL; |
| found: |
| return s; |
| } |
| |
| static inline struct sock *unix_find_socket_byname(struct net *net, |
| struct sockaddr_un *sunname, |
| int len, int type, |
| unsigned hash) |
| { |
| struct sock *s; |
| |
| spin_lock(&unix_table_lock); |
| s = __unix_find_socket_byname(net, sunname, len, type, hash); |
| if (s) |
| sock_hold(s); |
| spin_unlock(&unix_table_lock); |
| return s; |
| } |
| |
| static struct sock *unix_find_socket_byinode(struct inode *i) |
| { |
| struct sock *s; |
| struct hlist_node *node; |
| |
| spin_lock(&unix_table_lock); |
| sk_for_each(s, node, |
| &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) { |
| struct dentry *dentry = unix_sk(s)->path.dentry; |
| |
| if (dentry && dentry->d_inode == i) { |
| sock_hold(s); |
| goto found; |
| } |
| } |
| s = NULL; |
| found: |
| spin_unlock(&unix_table_lock); |
| return s; |
| } |
| |
| static inline int unix_writable(struct sock *sk) |
| { |
| return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf; |
| } |
| |
| static void unix_write_space(struct sock *sk) |
| { |
| struct socket_wq *wq; |
| |
| rcu_read_lock(); |
| if (unix_writable(sk)) { |
| wq = rcu_dereference(sk->sk_wq); |
| if (wq_has_sleeper(wq)) |
| wake_up_interruptible_sync_poll(&wq->wait, |
| POLLOUT | POLLWRNORM | POLLWRBAND); |
| sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); |
| } |
| rcu_read_unlock(); |
| } |
| |
| /* When dgram socket disconnects (or changes its peer), we clear its receive |
| * queue of packets arrived from previous peer. First, it allows to do |
| * flow control based only on wmem_alloc; second, sk connected to peer |
| * may receive messages only from that peer. */ |
| static void unix_dgram_disconnected(struct sock *sk, struct sock *other) |
| { |
| if (!skb_queue_empty(&sk->sk_receive_queue)) { |
| skb_queue_purge(&sk->sk_receive_queue); |
| wake_up_interruptible_all(&unix_sk(sk)->peer_wait); |
| |
| /* If one link of bidirectional dgram pipe is disconnected, |
| * we signal error. Messages are lost. Do not make this, |
| * when peer was not connected to us. |
| */ |
| if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) { |
| other->sk_err = ECONNRESET; |
| other->sk_error_report(other); |
| } |
| } |
| } |
| |
| static void unix_sock_destructor(struct sock *sk) |
| { |
| struct unix_sock *u = unix_sk(sk); |
| |
| skb_queue_purge(&sk->sk_receive_queue); |
| |
| WARN_ON(atomic_read(&sk->sk_wmem_alloc)); |
| WARN_ON(!sk_unhashed(sk)); |
| WARN_ON(sk->sk_socket); |
| if (!sock_flag(sk, SOCK_DEAD)) { |
| WARN(1, "Attempt to release alive unix socket: %p\n", sk); |
| return; |
| } |
| |
| if (u->addr) |
| unix_release_addr(u->addr); |
| |
| atomic_long_dec(&unix_nr_socks); |
| local_bh_disable(); |
| sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); |
| local_bh_enable(); |
| #ifdef UNIX_REFCNT_DEBUG |
| printk(KERN_DEBUG "UNIX %p is destroyed, %ld are still alive.\n", sk, |
| atomic_long_read(&unix_nr_socks)); |
| #endif |
| } |
| |
| static void unix_release_sock(struct sock *sk, int embrion) |
| { |
| struct unix_sock *u = unix_sk(sk); |
| struct path path; |
| struct sock *skpair; |
| struct sk_buff *skb; |
| int state; |
| |
| unix_remove_socket(sk); |
| |
| /* Clear state */ |
| unix_state_lock(sk); |
| sock_orphan(sk); |
| sk->sk_shutdown = SHUTDOWN_MASK; |
| path = u->path; |
| u->path.dentry = NULL; |
| u->path.mnt = NULL; |
| state = sk->sk_state; |
| sk->sk_state = TCP_CLOSE; |
| unix_state_unlock(sk); |
| |
| wake_up_interruptible_all(&u->peer_wait); |
| |
| skpair = unix_peer(sk); |
| |
| if (skpair != NULL) { |
| if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) { |
| unix_state_lock(skpair); |
| /* No more writes */ |
| skpair->sk_shutdown = SHUTDOWN_MASK; |
| if (!skb_queue_empty(&sk->sk_receive_queue) || embrion) |
| skpair->sk_err = ECONNRESET; |
| unix_state_unlock(skpair); |
| skpair->sk_state_change(skpair); |
| sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP); |
| } |
| sock_put(skpair); /* It may now die */ |
| unix_peer(sk) = NULL; |
| } |
| |
| /* Try to flush out this socket. Throw out buffers at least */ |
| |
| while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { |
| if (state == TCP_LISTEN) |
| unix_release_sock(skb->sk, 1); |
| /* passed fds are erased in the kfree_skb hook */ |
| kfree_skb(skb); |
| } |
| |
| if (path.dentry) |
| path_put(&path); |
| |
| sock_put(sk); |
| |
| /* ---- Socket is dead now and most probably destroyed ---- */ |
| |
| /* |
| * Fixme: BSD difference: In BSD all sockets connected to use get |
| * ECONNRESET and we die on the spot. In Linux we behave |
| * like files and pipes do and wait for the last |
| * dereference. |
| * |
| * Can't we simply set sock->err? |
| * |
| * What the above comment does talk about? --ANK(980817) |
| */ |
| |
| if (unix_tot_inflight) |
| unix_gc(); /* Garbage collect fds */ |
| } |
| |
| static void init_peercred(struct sock *sk) |
| { |
| put_pid(sk->sk_peer_pid); |
| if (sk->sk_peer_cred) |
| put_cred(sk->sk_peer_cred); |
| sk->sk_peer_pid = get_pid(task_tgid(current)); |
| sk->sk_peer_cred = get_current_cred(); |
| } |
| |
| static void copy_peercred(struct sock *sk, struct sock *peersk) |
| { |
| put_pid(sk->sk_peer_pid); |
| if (sk->sk_peer_cred) |
| put_cred(sk->sk_peer_cred); |
| sk->sk_peer_pid = get_pid(peersk->sk_peer_pid); |
| sk->sk_peer_cred = get_cred(peersk->sk_peer_cred); |
| } |
| |
| static int unix_listen(struct socket *sock, int backlog) |
| { |
| int err; |
| struct sock *sk = sock->sk; |
| struct unix_sock *u = unix_sk(sk); |
| struct pid *old_pid = NULL; |
| const struct cred *old_cred = NULL; |
| |
| err = -EOPNOTSUPP; |
| if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
| goto out; /* Only stream/seqpacket sockets accept */ |
| err = -EINVAL; |
| if (!u->addr) |
| goto out; /* No listens on an unbound socket */ |
| unix_state_lock(sk); |
| if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) |
| goto out_unlock; |
| if (backlog > sk->sk_max_ack_backlog) |
| wake_up_interruptible_all(&u->peer_wait); |
| sk->sk_max_ack_backlog = backlog; |
| sk->sk_state = TCP_LISTEN; |
| /* set credentials so connect can copy them */ |
| init_peercred(sk); |
| err = 0; |
| |
| out_unlock: |
| unix_state_unlock(sk); |
| put_pid(old_pid); |
| if (old_cred) |
| put_cred(old_cred); |
| out: |
| return err; |
| } |
| |
| static int unix_release(struct socket *); |
| static int unix_bind(struct socket *, struct sockaddr *, int); |
| static int unix_stream_connect(struct socket *, struct sockaddr *, |
| int addr_len, int flags); |
| static int unix_socketpair(struct socket *, struct socket *); |
| static int unix_accept(struct socket *, struct socket *, int); |
| static int unix_getname(struct socket *, struct sockaddr *, int *, int); |
| static unsigned int unix_poll(struct file *, struct socket *, poll_table *); |
| static unsigned int unix_dgram_poll(struct file *, struct socket *, |
| poll_table *); |
| static int unix_ioctl(struct socket *, unsigned int, unsigned long); |
| static int unix_shutdown(struct socket *, int); |
| static int unix_stream_sendmsg(struct kiocb *, struct socket *, |
| struct msghdr *, size_t); |
| static int unix_stream_recvmsg(struct kiocb *, struct socket *, |
| struct msghdr *, size_t, int); |
| static int unix_dgram_sendmsg(struct kiocb *, struct socket *, |
| struct msghdr *, size_t); |
| static int unix_dgram_recvmsg(struct kiocb *, struct socket *, |
| struct msghdr *, size_t, int); |
| static int unix_dgram_connect(struct socket *, struct sockaddr *, |
| int, int); |
| static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *, |
| struct msghdr *, size_t); |
| static int unix_seqpacket_recvmsg(struct kiocb *, struct socket *, |
| struct msghdr *, size_t, int); |
| |
| static void unix_set_peek_off(struct sock *sk, int val) |
| { |
| struct unix_sock *u = unix_sk(sk); |
| |
| mutex_lock(&u->readlock); |
| sk->sk_peek_off = val; |
| mutex_unlock(&u->readlock); |
| } |
| |
| |
| static const struct proto_ops unix_stream_ops = { |
| .family = PF_UNIX, |
| .owner = THIS_MODULE, |
| .release = unix_release, |
| .bind = unix_bind, |
| .connect = unix_stream_connect, |
| .socketpair = unix_socketpair, |
| .accept = unix_accept, |
| .getname = unix_getname, |
| .poll = unix_poll, |
| .ioctl = unix_ioctl, |
| .listen = unix_listen, |
| .shutdown = unix_shutdown, |
| .setsockopt = sock_no_setsockopt, |
| .getsockopt = sock_no_getsockopt, |
| .sendmsg = unix_stream_sendmsg, |
| .recvmsg = unix_stream_recvmsg, |
| .mmap = sock_no_mmap, |
| .sendpage = sock_no_sendpage, |
| .set_peek_off = unix_set_peek_off, |
| }; |
| |
| static const struct proto_ops unix_dgram_ops = { |
| .family = PF_UNIX, |
| .owner = THIS_MODULE, |
| .release = unix_release, |
| .bind = unix_bind, |
| .connect = unix_dgram_connect, |
| .socketpair = unix_socketpair, |
| .accept = sock_no_accept, |
| .getname = unix_getname, |
| .poll = unix_dgram_poll, |
| .ioctl = unix_ioctl, |
| .listen = sock_no_listen, |
| .shutdown = unix_shutdown, |
| .setsockopt = sock_no_setsockopt, |
| .getsockopt = sock_no_getsockopt, |
| .sendmsg = unix_dgram_sendmsg, |
| .recvmsg = unix_dgram_recvmsg, |
| .mmap = sock_no_mmap, |
| .sendpage = sock_no_sendpage, |
| .set_peek_off = unix_set_peek_off, |
| }; |
| |
| static const struct proto_ops unix_seqpacket_ops = { |
| .family = PF_UNIX, |
| .owner = THIS_MODULE, |
| .release = unix_release, |
| .bind = unix_bind, |
| .connect = unix_stream_connect, |
| .socketpair = unix_socketpair, |
| .accept = unix_accept, |
| .getname = unix_getname, |
| .poll = unix_dgram_poll, |
| .ioctl = unix_ioctl, |
| .listen = unix_listen, |
| .shutdown = unix_shutdown, |
| .setsockopt = sock_no_setsockopt, |
| .getsockopt = sock_no_getsockopt, |
| .sendmsg = unix_seqpacket_sendmsg, |
| .recvmsg = unix_seqpacket_recvmsg, |
| .mmap = sock_no_mmap, |
| .sendpage = sock_no_sendpage, |
| .set_peek_off = unix_set_peek_off, |
| }; |
| |
| static struct proto unix_proto = { |
| .name = "UNIX", |
| .owner = THIS_MODULE, |
| .obj_size = sizeof(struct unix_sock), |
| }; |
| |
| /* |
| * AF_UNIX sockets do not interact with hardware, hence they |
| * dont trigger interrupts - so it's safe for them to have |
| * bh-unsafe locking for their sk_receive_queue.lock. Split off |
| * this special lock-class by reinitializing the spinlock key: |
| */ |
| static struct lock_class_key af_unix_sk_receive_queue_lock_key; |
| |
| static struct sock *unix_create1(struct net *net, struct socket *sock) |
| { |
| struct sock *sk = NULL; |
| struct unix_sock *u; |
| |
| atomic_long_inc(&unix_nr_socks); |
| if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files()) |
| goto out; |
| |
| sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto); |
| if (!sk) |
| goto out; |
| |
| sock_init_data(sock, sk); |
| lockdep_set_class(&sk->sk_receive_queue.lock, |
| &af_unix_sk_receive_queue_lock_key); |
| |
| sk->sk_write_space = unix_write_space; |
| sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen; |
| sk->sk_destruct = unix_sock_destructor; |
| u = unix_sk(sk); |
| u->path.dentry = NULL; |
| u->path.mnt = NULL; |
| spin_lock_init(&u->lock); |
| atomic_long_set(&u->inflight, 0); |
| INIT_LIST_HEAD(&u->link); |
| mutex_init(&u->readlock); /* single task reading lock */ |
| init_waitqueue_head(&u->peer_wait); |
| unix_insert_socket(unix_sockets_unbound, sk); |
| out: |
| if (sk == NULL) |
| atomic_long_dec(&unix_nr_socks); |
| else { |
| local_bh_disable(); |
| sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); |
| local_bh_enable(); |
| } |
| return sk; |
| } |
| |
| static int unix_create(struct net *net, struct socket *sock, int protocol, |
| int kern) |
| { |
| if (protocol && protocol != PF_UNIX) |
| return -EPROTONOSUPPORT; |
| |
| sock->state = SS_UNCONNECTED; |
| |
| switch (sock->type) { |
| case SOCK_STREAM: |
| sock->ops = &unix_stream_ops; |
| break; |
| /* |
| * Believe it or not BSD has AF_UNIX, SOCK_RAW though |
| * nothing uses it. |
| */ |
| case SOCK_RAW: |
| sock->type = SOCK_DGRAM; |
| case SOCK_DGRAM: |
| sock->ops = &unix_dgram_ops; |
| break; |
| case SOCK_SEQPACKET: |
| sock->ops = &unix_seqpacket_ops; |
| break; |
| default: |
| return -ESOCKTNOSUPPORT; |
| } |
| |
| return unix_create1(net, sock) ? 0 : -ENOMEM; |
| } |
| |
| static int unix_release(struct socket *sock) |
| { |
| struct sock *sk = sock->sk; |
| |
| if (!sk) |
| return 0; |
| |
| unix_release_sock(sk, 0); |
| sock->sk = NULL; |
| |
| return 0; |
| } |
| |
| static int unix_autobind(struct socket *sock) |
| { |
| struct sock *sk = sock->sk; |
| struct net *net = sock_net(sk); |
| struct unix_sock *u = unix_sk(sk); |
| static u32 ordernum = 1; |
| struct unix_address *addr; |
| int err; |
| unsigned int retries = 0; |
| |
| mutex_lock(&u->readlock); |
| |
| err = 0; |
| if (u->addr) |
| goto out; |
| |
| err = -ENOMEM; |
| addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); |
| if (!addr) |
| goto out; |
| |
| addr->name->sun_family = AF_UNIX; |
| atomic_set(&addr->refcnt, 1); |
| |
| retry: |
| addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); |
| addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0)); |
| |
| spin_lock(&unix_table_lock); |
| ordernum = (ordernum+1)&0xFFFFF; |
| |
| if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type, |
| addr->hash)) { |
| spin_unlock(&unix_table_lock); |
| /* |
| * __unix_find_socket_byname() may take long time if many names |
| * are already in use. |
| */ |
| cond_resched(); |
| /* Give up if all names seems to be in use. */ |
| if (retries++ == 0xFFFFF) { |
| err = -ENOSPC; |
| kfree(addr); |
| goto out; |
| } |
| goto retry; |
| } |
| addr->hash ^= sk->sk_type; |
| |
| __unix_remove_socket(sk); |
| u->addr = addr; |
| __unix_insert_socket(&unix_socket_table[addr->hash], sk); |
| spin_unlock(&unix_table_lock); |
| err = 0; |
| |
| out: mutex_unlock(&u->readlock); |
| return err; |
| } |
| |
| static struct sock *unix_find_other(struct net *net, |
| struct sockaddr_un *sunname, int len, |
| int type, unsigned hash, int *error) |
| { |
| struct sock *u; |
| struct path path; |
| int err = 0; |
| |
| if (sunname->sun_path[0]) { |
| struct inode *inode; |
| err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path); |
| if (err) |
| goto fail; |
| inode = path.dentry->d_inode; |
| err = inode_permission(inode, MAY_WRITE); |
| if (err) |
| goto put_fail; |
| |
| err = -ECONNREFUSED; |
| if (!S_ISSOCK(inode->i_mode)) |
| goto put_fail; |
| u = unix_find_socket_byinode(inode); |
| if (!u) |
| goto put_fail; |
| |
| if (u->sk_type == type) |
| touch_atime(&path); |
| |
| path_put(&path); |
| |
| err = -EPROTOTYPE; |
| if (u->sk_type != type) { |
| sock_put(u); |
| goto fail; |
| } |
| } else { |
| err = -ECONNREFUSED; |
| u = unix_find_socket_byname(net, sunname, len, type, hash); |
| if (u) { |
| struct dentry *dentry; |
| dentry = unix_sk(u)->path.dentry; |
| if (dentry) |
| touch_atime(&unix_sk(u)->path); |
| } else |
| goto fail; |
| } |
| return u; |
| |
| put_fail: |
| path_put(&path); |
| fail: |
| *error = err; |
| return NULL; |
| } |
| |
| |
| static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) |
| { |
| struct sock *sk = sock->sk; |
| struct net *net = sock_net(sk); |
| struct unix_sock *u = unix_sk(sk); |
| struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
| char *sun_path = sunaddr->sun_path; |
| struct dentry *dentry = NULL; |
| struct path path; |
| int err; |
| unsigned hash; |
| struct unix_address *addr; |
| struct hlist_head *list; |
| |
| err = -EINVAL; |
| if (sunaddr->sun_family != AF_UNIX) |
| goto out; |
| |
| if (addr_len == sizeof(short)) { |
| err = unix_autobind(sock); |
| goto out; |
| } |
| |
| err = unix_mkname(sunaddr, addr_len, &hash); |
| if (err < 0) |
| goto out; |
| addr_len = err; |
| |
| mutex_lock(&u->readlock); |
| |
| err = -EINVAL; |
| if (u->addr) |
| goto out_up; |
| |
| err = -ENOMEM; |
| addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL); |
| if (!addr) |
| goto out_up; |
| |
| memcpy(addr->name, sunaddr, addr_len); |
| addr->len = addr_len; |
| addr->hash = hash ^ sk->sk_type; |
| atomic_set(&addr->refcnt, 1); |
| |
| if (sun_path[0]) { |
| umode_t mode; |
| err = 0; |
| /* |
| * Get the parent directory, calculate the hash for last |
| * component. |
| */ |
| dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0); |
| err = PTR_ERR(dentry); |
| if (IS_ERR(dentry)) |
| goto out_mknod_parent; |
| |
| /* |
| * All right, let's create it. |
| */ |
| mode = S_IFSOCK | |
| (SOCK_INODE(sock)->i_mode & ~current_umask()); |
| err = security_path_mknod(&path, dentry, mode, 0); |
| if (err) |
| goto out_mknod_drop_write; |
| err = vfs_mknod(path.dentry->d_inode, dentry, mode, 0); |
| out_mknod_drop_write: |
| if (err) |
| goto out_mknod_dput; |
| mntget(path.mnt); |
| dget(dentry); |
| done_path_create(&path, dentry); |
| path.dentry = dentry; |
| |
| addr->hash = UNIX_HASH_SIZE; |
| } |
| |
| spin_lock(&unix_table_lock); |
| |
| if (!sun_path[0]) { |
| err = -EADDRINUSE; |
| if (__unix_find_socket_byname(net, sunaddr, addr_len, |
| sk->sk_type, hash)) { |
| unix_release_addr(addr); |
| goto out_unlock; |
| } |
| |
| list = &unix_socket_table[addr->hash]; |
| } else { |
| list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)]; |
| u->path = path; |
| } |
| |
| err = 0; |
| __unix_remove_socket(sk); |
| u->addr = addr; |
| __unix_insert_socket(list, sk); |
| |
| out_unlock: |
| spin_unlock(&unix_table_lock); |
| out_up: |
| mutex_unlock(&u->readlock); |
| out: |
| return err; |
| |
| out_mknod_dput: |
| done_path_create(&path, dentry); |
| out_mknod_parent: |
| if (err == -EEXIST) |
| err = -EADDRINUSE; |
| unix_release_addr(addr); |
| goto out_up; |
| } |
| |
| static void unix_state_double_lock(struct sock *sk1, struct sock *sk2) |
| { |
| if (unlikely(sk1 == sk2) || !sk2) { |
| unix_state_lock(sk1); |
| return; |
| } |
| if (sk1 < sk2) { |
| unix_state_lock(sk1); |
| unix_state_lock_nested(sk2); |
| } else { |
| unix_state_lock(sk2); |
| unix_state_lock_nested(sk1); |
| } |
| } |
| |
| static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2) |
| { |
| if (unlikely(sk1 == sk2) || !sk2) { |
| unix_state_unlock(sk1); |
| return; |
| } |
| unix_state_unlock(sk1); |
| unix_state_unlock(sk2); |
| } |
| |
| static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, |
| int alen, int flags) |
| { |
| struct sock *sk = sock->sk; |
| struct net *net = sock_net(sk); |
| struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr; |
| struct sock *other; |
| unsigned hash; |
| int err; |
| |
| if (addr->sa_family != AF_UNSPEC) { |
| err = unix_mkname(sunaddr, alen, &hash); |
| if (err < 0) |
| goto out; |
| alen = err; |
| |
| if (test_bit(SOCK_PASSCRED, &sock->flags) && |
| !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0) |
| goto out; |
| |
| restart: |
| other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err); |
| if (!other) |
| goto out; |
| |
| unix_state_double_lock(sk, other); |
| |
| /* Apparently VFS overslept socket death. Retry. */ |
| if (sock_flag(other, SOCK_DEAD)) { |
| unix_state_double_unlock(sk, other); |
| sock_put(other); |
| goto restart; |
| } |
| |
| err = -EPERM; |
| if (!unix_may_send(sk, other)) |
| goto out_unlock; |
| |
| err = security_unix_may_send(sk->sk_socket, other->sk_socket); |
| if (err) |
| goto out_unlock; |
| |
| } else { |
| /* |
| * 1003.1g breaking connected state with AF_UNSPEC |
| */ |
| other = NULL; |
| unix_state_double_lock(sk, other); |
| } |
| |
| /* |
| * If it was connected, reconnect. |
| */ |
| if (unix_peer(sk)) { |
| struct sock *old_peer = unix_peer(sk); |
| unix_peer(sk) = other; |
| unix_state_double_unlock(sk, other); |
| |
| if (other != old_peer) |
| unix_dgram_disconnected(sk, old_peer); |
| sock_put(old_peer); |
| } else { |
| unix_peer(sk) = other; |
| unix_state_double_unlock(sk, other); |
| } |
| return 0; |
| |
| out_unlock: |
| unix_state_double_unlock(sk, other); |
| sock_put(other); |
| out: |
| return err; |
| } |
| |
| static long unix_wait_for_peer(struct sock *other, long timeo) |
| { |
| struct unix_sock *u = unix_sk(other); |
| int sched; |
| DEFINE_WAIT(wait); |
| |
| prepare_to_wait_exclusive(&u->peer_wait, &wait, TASK_INTERRUPTIBLE); |
| |
| sched = !sock_flag(other, SOCK_DEAD) && |
| !(other->sk_shutdown & RCV_SHUTDOWN) && |
| unix_recvq_full(other); |
| |
| unix_state_unlock(other); |
| |
| if (sched) |
| timeo = schedule_timeout(timeo); |
| |
| finish_wait(&u->peer_wait, &wait); |
| return timeo; |
| } |
| |
| static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, |
| int addr_len, int flags) |
| { |
| struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr; |
| struct sock *sk = sock->sk; |
| struct net *net = sock_net(sk); |
| struct unix_sock *u = unix_sk(sk), *newu, *otheru; |
| struct sock *newsk = NULL; |
| struct sock *other = NULL; |
| struct sk_buff *skb = NULL; |
| unsigned hash; |
| int st; |
| int err; |
| long timeo; |
| |
| err = unix_mkname(sunaddr, addr_len, &hash); |
| if (err < 0) |
| goto out; |
| addr_len = err; |
| |
| if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr && |
| (err = unix_autobind(sock)) != 0) |
| goto out; |
| |
| timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); |
| |
| /* First of all allocate resources. |
| If we will make it after state is locked, |
| we will have to recheck all again in any case. |
| */ |
| |
| err = -ENOMEM; |
| |
| /* create new sock for complete connection */ |
| newsk = unix_create1(sock_net(sk), NULL); |
| if (newsk == NULL) |
| goto out; |
| |
| /* Allocate skb for sending to listening sock */ |
| skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL); |
| if (skb == NULL) |
| goto out; |
| |
| restart: |
| /* Find listening sock. */ |
| other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err); |
| if (!other) |
| goto out; |
| |
| /* Latch state of peer */ |
| unix_state_lock(other); |
| |
| /* Apparently VFS overslept socket death. Retry. */ |
| if (sock_flag(other, SOCK_DEAD)) { |
| unix_state_unlock(other); |
| sock_put(other); |
| goto restart; |
| } |
| |
| err = -ECONNREFUSED; |
| if (other->sk_state != TCP_LISTEN) |
| goto out_unlock; |
| if (other->sk_shutdown & RCV_SHUTDOWN) |
| goto out_unlock; |
| |
| if (unix_recvq_full(other)) { |
| err = -EAGAIN; |
| if (!timeo) |
| goto out_unlock; |
| |
| timeo = unix_wait_for_peer(other, timeo); |
| |
| err = sock_intr_errno(timeo); |
| if (signal_pending(current)) |
| goto out; |
| sock_put(other); |
| goto restart; |
| } |
| |
| /* Latch our state. |
| |
| It is tricky place. We need to grab our state lock and cannot |
| drop lock on peer. It is dangerous because deadlock is |
| possible. Connect to self case and simultaneous |
| attempt to connect are eliminated by checking socket |
| state. other is TCP_LISTEN, if sk is TCP_LISTEN we |
| check this before attempt to grab lock. |
| |
| Well, and we have to recheck the state after socket locked. |
| */ |
| st = sk->sk_state; |
| |
| switch (st) { |
| case TCP_CLOSE: |
| /* This is ok... continue with connect */ |
| break; |
| case TCP_ESTABLISHED: |
| /* Socket is already connected */ |
| err = -EISCONN; |
| goto out_unlock; |
| default: |
| err = -EINVAL; |
| goto out_unlock; |
| } |
| |
| unix_state_lock_nested(sk); |
| |
| if (sk->sk_state != st) { |
| unix_state_unlock(sk); |
| unix_state_unlock(other); |
| sock_put(other); |
| goto restart; |
| } |
| |
| err = security_unix_stream_connect(sk, other, newsk); |
| if (err) { |
| unix_state_unlock(sk); |
| goto out_unlock; |
| } |
| |
| /* The way is open! Fastly set all the necessary fields... */ |
| |
| sock_hold(sk); |
| unix_peer(newsk) = sk; |
| newsk->sk_state = TCP_ESTABLISHED; |
| newsk->sk_type = sk->sk_type; |
| init_peercred(newsk); |
| newu = unix_sk(newsk); |
| RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq); |
| otheru = unix_sk(other); |
| |
| /* copy address information from listening to new sock*/ |
| if (otheru->addr) { |
| atomic_inc(&otheru->addr->refcnt); |
| newu->addr = otheru->addr; |
| } |
| if (otheru->path.dentry) { |
| path_get(&otheru->path); |
| newu->path = otheru->path; |
| } |
| |
| /* Set credentials */ |
| copy_peercred(sk, other); |
| |
| sock->state = SS_CONNECTED; |
| sk->sk_state = TCP_ESTABLISHED; |
| sock_hold(newsk); |
| |
| smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */ |
| unix_peer(sk) = newsk; |
| |
| unix_state_unlock(sk); |
| |
| /* take ten and and send info to listening sock */ |
| spin_lock(&other->sk_receive_queue.lock); |
| __skb_queue_tail(&other->sk_receive_queue, skb); |
| spin_unlock(&other->sk_receive_queue.lock); |
| unix_state_unlock(other); |
| other->sk_data_ready(other, 0); |
| sock_put(other); |
| return 0; |
| |
| out_unlock: |
| if (other) |
| unix_state_unlock(other); |
| |
| out: |
| kfree_skb(skb); |
| if (newsk) |
| unix_release_sock(newsk, 0); |
| if (other) |
| sock_put(other); |
| return err; |
| } |
| |
| static int unix_socketpair(struct socket *socka, struct socket *sockb) |
| { |
| struct sock *ska = socka->sk, *skb = sockb->sk; |
| |
| /* Join our sockets back to back */ |
| sock_hold(ska); |
| sock_hold(skb); |
| unix_peer(ska) = skb; |
| unix_peer(skb) = ska; |
| init_peercred(ska); |
| init_peercred(skb); |
| |
| if (ska->sk_type != SOCK_DGRAM) { |
| ska->sk_state = TCP_ESTABLISHED; |
| skb->sk_state = TCP_ESTABLISHED; |
| socka->state = SS_CONNECTED; |
| sockb->state = SS_CONNECTED; |
| } |
| return 0; |
| } |
| |
| static void unix_sock_inherit_flags(const struct socket *old, |
| struct socket *new) |
| { |
| if (test_bit(SOCK_PASSCRED, &old->flags)) |
| set_bit(SOCK_PASSCRED, &new->flags); |
| if (test_bit(SOCK_PASSSEC, &old->flags)) |
| set_bit(SOCK_PASSSEC, &new->flags); |
| } |
| |
| static int unix_accept(struct socket *sock, struct socket *newsock, int flags) |
| { |
| struct sock *sk = sock->sk; |
| struct sock *tsk; |
| struct sk_buff *skb; |
| int err; |
| |
| err = -EOPNOTSUPP; |
| if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET) |
| goto out; |
| |
| err = -EINVAL; |
| if (sk->sk_state != TCP_LISTEN) |
| goto out; |
| |
| /* If socket state is TCP_LISTEN it cannot change (for now...), |
| * so that no locks are necessary. |
| */ |
| |
| skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); |
| if (!skb) { |
| /* This means receive shutdown. */ |
| if (err == 0) |
| err = -EINVAL; |
| goto out; |
| } |
| |
| tsk = skb->sk; |
| skb_free_datagram(sk, skb); |
| wake_up_interruptible(&unix_sk(sk)->peer_wait); |
| |
| /* attach accepted sock to socket */ |
| unix_state_lock(tsk); |
| newsock->state = SS_CONNECTED; |
| unix_sock_inherit_flags(sock, newsock); |
| sock_graft(tsk, newsock); |
| unix_state_unlock(tsk); |
| return 0; |
| |
| out: |
| return err; |
| } |
| |
| |
| static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) |
| { |
| struct sock *sk = sock->sk; |
| struct unix_sock *u; |
| DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr); |
| int err = 0; |
| |
| if (peer) { |
| sk = unix_peer_get(sk); |
| |
| err = -ENOTCONN; |
| if (!sk) |
| goto out; |
| err = 0; |
| } else { |
| sock_hold(sk); |
| } |
| |
| u = unix_sk(sk); |
| unix_state_lock(sk); |
| if (!u->addr) { |
| sunaddr->sun_family = AF_UNIX; |
| sunaddr->sun_path[0] = 0; |
| *uaddr_len = sizeof(short); |
| } else { |
| struct unix_address *addr = u->addr; |
| |
| *uaddr_len = addr->len; |
| memcpy(sunaddr, addr->name, *uaddr_len); |
| } |
| unix_state_unlock(sk); |
| sock_put(sk); |
| out: |
| return err; |
| } |
| |
| static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) |
| { |
| int i; |
| |
| scm->fp = UNIXCB(skb).fp; |
| UNIXCB(skb).fp = NULL; |
| |
| for (i = scm->fp->count-1; i >= 0; i--) |
| unix_notinflight(scm->fp->user, scm->fp->fp[i]); |
| } |
| |
| static void unix_destruct_scm(struct sk_buff *skb) |
| { |
| struct scm_cookie scm; |
| memset(&scm, 0, sizeof(scm)); |
| scm.pid = UNIXCB(skb).pid; |
| scm.cred = UNIXCB(skb).cred; |
| if (UNIXCB(skb).fp) |
| unix_detach_fds(&scm, skb); |
| |
| /* Alas, it calls VFS */ |
| /* So fscking what? fput() had been SMP-safe since the last Summer */ |
| scm_destroy(&scm); |
| sock_wfree(skb); |
| } |
| |
| /* |
| * The "user->unix_inflight" variable is protected by the garbage |
| * collection lock, and we just read it locklessly here. If you go |
| * over the limit, there might be a tiny race in actually noticing |
| * it across threads. Tough. |
| */ |
| static inline bool too_many_unix_fds(struct task_struct *p) |
| { |
| struct user_struct *user = current_user(); |
| |
| if (unlikely(user->unix_inflight > task_rlimit(p, RLIMIT_NOFILE))) |
| return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN); |
| return false; |
| } |
| |
| #define MAX_RECURSION_LEVEL 4 |
| |
| static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) |
| { |
| int i; |
| unsigned char max_level = 0; |
| int unix_sock_count = 0; |
| |
| if (too_many_unix_fds(current)) |
| return -ETOOMANYREFS; |
| |
| for (i = scm->fp->count - 1; i >= 0; i--) { |
| struct sock *sk = unix_get_socket(scm->fp->fp[i]); |
| |
| if (sk) { |
| unix_sock_count++; |
| max_level = max(max_level, |
| unix_sk(sk)->recursion_level); |
| } |
| } |
| if (unlikely(max_level > MAX_RECURSION_LEVEL)) |
| return -ETOOMANYREFS; |
| |
| /* |
| * Need to duplicate file references for the sake of garbage |
| * collection. Otherwise a socket in the fps might become a |
| * candidate for GC while the skb is not yet queued. |
| */ |
| UNIXCB(skb).fp = scm_fp_dup(scm->fp); |
| if (!UNIXCB(skb).fp) |
| return -ENOMEM; |
| |
| for (i = scm->fp->count - 1; i >= 0; i--) |
| unix_inflight(scm->fp->user, scm->fp->fp[i]); |
| return max_level; |
| } |
| |
| static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds) |
| { |
| int err = 0; |
| |
| UNIXCB(skb).pid = get_pid(scm->pid); |
| if (scm->cred) |
| UNIXCB(skb).cred = get_cred(scm->cred); |
| UNIXCB(skb).fp = NULL; |
| if (scm->fp && send_fds) |
| err = unix_attach_fds(scm, skb); |
| |
| skb->destructor = unix_destruct_scm; |
| return err; |
| } |
| |
| /* |
| * Some apps rely on write() giving SCM_CREDENTIALS |
| * We include credentials if source or destination socket |
| * asserted SOCK_PASSCRED. |
| */ |
| static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock, |
| const struct sock *other) |
| { |
| if (UNIXCB(skb).cred) |
| return; |
| if (test_bit(SOCK_PASSCRED, &sock->flags) || |
| !other->sk_socket || |
| test_bit(SOCK_PASSCRED, &other->sk_socket->flags)) { |
| UNIXCB(skb).pid = get_pid(task_tgid(current)); |
| UNIXCB(skb).cred = get_current_cred(); |
| } |
| } |
| |
| /* |
| * Send AF_UNIX data. |
| */ |
| |
| static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, |
| struct msghdr *msg, size_t len) |
| { |
| struct sock_iocb *siocb = kiocb_to_siocb(kiocb); |
| struct sock *sk = sock->sk; |
| struct net *net = sock_net(sk); |
| struct unix_sock *u = unix_sk(sk); |
| struct sockaddr_un *sunaddr = msg->msg_name; |
| struct sock *other = NULL; |
| int namelen = 0; /* fake GCC */ |
| int err; |
| unsigned hash; |
| struct sk_buff *skb; |
| long timeo; |
| struct scm_cookie tmp_scm; |
| int max_level; |
| |
| if (NULL == siocb->scm) |
| siocb->scm = &tmp_scm; |
| wait_for_unix_gc(); |
| err = scm_send(sock, msg, siocb->scm, false); |
| if (err < 0) |
| return err; |
| |
| err = -EOPNOTSUPP; |
| if (msg->msg_flags&MSG_OOB) |
| goto out; |
| |
| if (msg->msg_namelen) { |
| err = unix_mkname(sunaddr, msg->msg_namelen, &hash); |
| if (err < 0) |
| goto out; |
| namelen = err; |
| } else { |
| sunaddr = NULL; |
| err = -ENOTCONN; |
| other = unix_peer_get(sk); |
| if (!other) |
| goto out; |
| } |
| |
| if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr |
| && (err = unix_autobind(sock)) != 0) |
| goto out; |
| |
| err = -EMSGSIZE; |
| if (len > sk->sk_sndbuf - 32) |
| goto out; |
| |
| skb = sock_alloc_send_skb(sk, len, msg->msg_flags&MSG_DONTWAIT, &err); |
| if (skb == NULL) |
| goto out; |
| |
| err = unix_scm_to_skb(siocb->scm, skb, true); |
| if (err < 0) |
| goto out_free; |
| max_level = err + 1; |
| unix_get_secdata(siocb->scm, skb); |
| |
| skb_reset_transport_header(skb); |
| err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); |
| if (err) |
| goto out_free; |
| |
| timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); |
| |
| restart: |
| if (!other) { |
| err = -ECONNRESET; |
| if (sunaddr == NULL) |
| goto out_free; |
| |
| other = unix_find_other(net, sunaddr, namelen, sk->sk_type, |
| hash, &err); |
| if (other == NULL) |
| goto out_free; |
| } |
| |
| if (sk_filter(other, skb) < 0) { |
| /* Toss the packet but do not return any error to the sender */ |
| err = len; |
| goto out_free; |
| } |
| |
| unix_state_lock(other); |
| err = -EPERM; |
| if (!unix_may_send(sk, other)) |
| goto out_unlock; |
| |
| if (sock_flag(other, SOCK_DEAD)) { |
| /* |
| * Check with 1003.1g - what should |
| * datagram error |
| */ |
| unix_state_unlock(other); |
| sock_put(other); |
| |
| err = 0; |
| unix_state_lock(sk); |
| if (unix_peer(sk) == other) { |
| unix_peer(sk) = NULL; |
| unix_state_unlock(sk); |
| |
| unix_dgram_disconnected(sk, other); |
| sock_put(other); |
| err = -ECONNREFUSED; |
| } else { |
| unix_state_unlock(sk); |
| } |
| |
| other = NULL; |
| if (err) |
| goto out_free; |
| goto restart; |
| } |
| |
| err = -EPIPE; |
| if (other->sk_shutdown & RCV_SHUTDOWN) |
| goto out_unlock; |
| |
| if (sk->sk_type != SOCK_SEQPACKET) { |
| err = security_unix_may_send(sk->sk_socket, other->sk_socket); |
| if (err) |
| goto out_unlock; |
| } |
| |
| if (unix_peer(other) != sk && unix_recvq_full(other)) { |
| if (!timeo) { |
| err = -EAGAIN; |
| goto out_unlock; |
| } |
| |
| timeo = unix_wait_for_peer(other, timeo); |
| |
| err = sock_intr_errno(timeo); |
| if (signal_pending(current)) |
| goto out_free; |
| |
| goto restart; |
| } |
| |
| if (sock_flag(other, SOCK_RCVTSTAMP)) |
| __net_timestamp(skb); |
| maybe_add_creds(skb, sock, other); |
| skb_queue_tail(&other->sk_receive_queue, skb); |
| if (max_level > unix_sk(other)->recursion_level) |
| unix_sk(other)->recursion_level = max_level; |
| unix_state_unlock(other); |
| other->sk_data_ready(other, len); |
| sock_put(other); |
| scm_destroy(siocb->scm); |
| return len; |
| |
| out_unlock: |
| unix_state_unlock(other); |
| out_free: |
| kfree_skb(skb); |
| out: |
| if (other) |
| sock_put(other); |
| scm_destroy(siocb->scm); |
| return err; |
| } |
| |
| |
| static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, |
| struct msghdr *msg, size_t len) |
| { |
| struct sock_iocb *siocb = kiocb_to_siocb(kiocb); |
| struct sock *sk = sock->sk; |
| struct sock *other = NULL; |
| int err, size; |
| struct sk_buff *skb; |
| int sent = 0; |
| struct scm_cookie tmp_scm; |
| bool fds_sent = false; |
| int max_level; |
| |
| if (NULL == siocb->scm) |
| siocb->scm = &tmp_scm; |
| wait_for_unix_gc(); |
| err = scm_send(sock, msg, siocb->scm, false); |
| if (err < 0) |
| return err; |
| |
| err = -EOPNOTSUPP; |
| if (msg->msg_flags&MSG_OOB) |
| goto out_err; |
| |
| if (msg->msg_namelen) { |
| err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; |
| goto out_err; |
| } else { |
| err = -ENOTCONN; |
| other = unix_peer(sk); |
| if (!other) |
| goto out_err; |
| } |
| |
| if (sk->sk_shutdown & SEND_SHUTDOWN) |
| goto pipe_err; |
| |
| while (sent < len) { |
| /* |
| * Optimisation for the fact that under 0.01% of X |
| * messages typically need breaking up. |
| */ |
| |
| size = len-sent; |
| |
| /* Keep two messages in the pipe so it schedules better */ |
| if (size > ((sk->sk_sndbuf >> 1) - 64)) |
| size = (sk->sk_sndbuf >> 1) - 64; |
| |
| if (size > SKB_MAX_ALLOC) |
| size = SKB_MAX_ALLOC; |
| |
| /* |
| * Grab a buffer |
| */ |
| |
| skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT, |
| &err); |
| |
| if (skb == NULL) |
| goto out_err; |
| |
| /* |
| * If you pass two values to the sock_alloc_send_skb |
| * it tries to grab the large buffer with GFP_NOFS |
| * (which can fail easily), and if it fails grab the |
| * fallback size buffer which is under a page and will |
| * succeed. [Alan] |
| */ |
| size = min_t(int, size, skb_tailroom(skb)); |
| |
| |
| /* Only send the fds in the first buffer */ |
| err = unix_scm_to_skb(siocb->scm, skb, !fds_sent); |
| if (err < 0) { |
| kfree_skb(skb); |
| goto out_err; |
| } |
| max_level = err + 1; |
| fds_sent = true; |
| |
| err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); |
| if (err) { |
| kfree_skb(skb); |
| goto out_err; |
| } |
| |
| unix_state_lock(other); |
| |
| if (sock_flag(other, SOCK_DEAD) || |
| (other->sk_shutdown & RCV_SHUTDOWN)) |
| goto pipe_err_free; |
| |
| maybe_add_creds(skb, sock, other); |
| skb_queue_tail(&other->sk_receive_queue, skb); |
| if (max_level > unix_sk(other)->recursion_level) |
| unix_sk(other)->recursion_level = max_level; |
| unix_state_unlock(other); |
| other->sk_data_ready(other, size); |
| sent += size; |
| } |
| |
| scm_destroy(siocb->scm); |
| siocb->scm = NULL; |
| |
| return sent; |
| |
| pipe_err_free: |
| unix_state_unlock(other); |
| kfree_skb(skb); |
| pipe_err: |
| if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) |
| send_sig(SIGPIPE, current, 0); |
| err = -EPIPE; |
| out_err: |
| scm_destroy(siocb->scm); |
| siocb->scm = NULL; |
| return sent ? : err; |
| } |
| |
| static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock, |
| struct msghdr *msg, size_t len) |
| { |
| int err; |
| struct sock *sk = sock->sk; |
| |
| err = sock_error(sk); |
| if (err) |
| return err; |
| |
| if (sk->sk_state != TCP_ESTABLISHED) |
| return -ENOTCONN; |
| |
| if (msg->msg_namelen) |
| msg->msg_namelen = 0; |
| |
| return unix_dgram_sendmsg(kiocb, sock, msg, len); |
| } |
| |
| static int unix_seqpacket_recvmsg(struct kiocb *iocb, struct socket *sock, |
| struct msghdr *msg, size_t size, |
| int flags) |
| { |
| struct sock *sk = sock->sk; |
| |
| if (sk->sk_state != TCP_ESTABLISHED) |
| return -ENOTCONN; |
| |
| return unix_dgram_recvmsg(iocb, sock, msg, size, flags); |
| } |
| |
| static void unix_copy_addr(struct msghdr *msg, struct sock *sk) |
| { |
| struct unix_sock *u = unix_sk(sk); |
| |
| msg->msg_namelen = 0; |
| if (u->addr) { |
| msg->msg_namelen = u->addr->len; |
| memcpy(msg->msg_name, u->addr->name, u->addr->len); |
| } |
| } |
| |
| static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, |
| struct msghdr *msg, size_t size, |
| int flags) |
| { |
| struct sock_iocb *siocb = kiocb_to_siocb(iocb); |
| struct scm_cookie tmp_scm; |
| struct sock *sk = sock->sk; |
| struct unix_sock *u = unix_sk(sk); |
| int noblock = flags & MSG_DONTWAIT; |
| struct sk_buff *skb; |
| int err; |
| int peeked, skip; |
| |
| err = -EOPNOTSUPP; |
| if (flags&MSG_OOB) |
| goto out; |
| |
| msg->msg_namelen = 0; |
| |
| err = mutex_lock_interruptible(&u->readlock); |
| if (err) { |
| err = sock_intr_errno(sock_rcvtimeo(sk, noblock)); |
| goto out; |
| } |
| |
| skip = sk_peek_offset(sk, flags); |
| |
| skb = __skb_recv_datagram(sk, flags, &peeked, &skip, &err); |
| if (!skb) { |
| unix_state_lock(sk); |
| /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ |
| if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && |
| (sk->sk_shutdown & RCV_SHUTDOWN)) |
| err = 0; |
| unix_state_unlock(sk); |
| goto out_unlock; |
| } |
| |
| wake_up_interruptible_sync_poll(&u->peer_wait, |
| POLLOUT | POLLWRNORM | POLLWRBAND); |
| |
| if (msg->msg_name) |
| unix_copy_addr(msg, skb->sk); |
| |
| if (size > skb->len - skip) |
| size = skb->len - skip; |
| else if (size < skb->len - skip) |
| msg->msg_flags |= MSG_TRUNC; |
| |
| err = skb_copy_datagram_iovec(skb, skip, msg->msg_iov, size); |
| if (err) |
| goto out_free; |
| |
| if (sock_flag(sk, SOCK_RCVTSTAMP)) |
| __sock_recv_timestamp(msg, sk, skb); |
| |
| if (!siocb->scm) { |
| siocb->scm = &tmp_scm; |
| memset(&tmp_scm, 0, sizeof(tmp_scm)); |
| } |
| scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred); |
| unix_set_secdata(siocb->scm, skb); |
| |
| if (!(flags & MSG_PEEK)) { |
| if (UNIXCB(skb).fp) |
| unix_detach_fds(siocb->scm, skb); |
| |
| sk_peek_offset_bwd(sk, skb->len); |
| } else { |
| /* It is questionable: on PEEK we could: |
| - do not return fds - good, but too simple 8) |
| - return fds, and do not return them on read (old strategy, |
| apparently wrong) |
| - clone fds (I chose it for now, it is the most universal |
| solution) |
| |
| POSIX 1003.1g does not actually define this clearly |
| at all. POSIX 1003.1g doesn't define a lot of things |
| clearly however! |
| |
| */ |
| |
| sk_peek_offset_fwd(sk, size); |
| |
| if (UNIXCB(skb).fp) |
| siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); |
| } |
| err = (flags & MSG_TRUNC) ? skb->len - skip : size; |
| |
| scm_recv(sock, msg, siocb->scm, flags); |
| |
| out_free: |
| skb_free_datagram(sk, skb); |
| out_unlock: |
| mutex_unlock(&u->readlock); |
| out: |
| return err; |
| } |
| |
| /* |
| * Sleep until data has arrive. But check for races.. |
| */ |
| |
| static long unix_stream_data_wait(struct sock *sk, long timeo) |
| { |
| DEFINE_WAIT(wait); |
| |
| unix_state_lock(sk); |
| |
| for (;;) { |
| prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); |
| |
| if (!skb_queue_empty(&sk->sk_receive_queue) || |
| sk->sk_err || |
| (sk->sk_shutdown & RCV_SHUTDOWN) || |
| signal_pending(current) || |
| !timeo) |
| break; |
| |
| set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); |
| unix_state_unlock(sk); |
| timeo = freezable_schedule_timeout(timeo); |
| unix_state_lock(sk); |
| clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); |
| } |
| |
| finish_wait(sk_sleep(sk), &wait); |
| unix_state_unlock(sk); |
| return timeo; |
| } |
| |
| |
| |
| static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, |
| struct msghdr *msg, size_t size, |
| int flags) |
| { |
| struct sock_iocb *siocb = kiocb_to_siocb(iocb); |
| struct scm_cookie tmp_scm; |
| struct sock *sk = sock->sk; |
| struct unix_sock *u = unix_sk(sk); |
| struct sockaddr_un *sunaddr = msg->msg_name; |
| int copied = 0; |
| int check_creds = 0; |
| int target; |
| int err = 0; |
| long timeo; |
| int skip; |
| |
| err = -EINVAL; |
| if (sk->sk_state != TCP_ESTABLISHED) |
| goto out; |
| |
| err = -EOPNOTSUPP; |
| if (flags&MSG_OOB) |
| goto out; |
| |
| target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); |
| timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); |
| |
| msg->msg_namelen = 0; |
| |
| /* Lock the socket to prevent queue disordering |
| * while sleeps in memcpy_tomsg |
| */ |
| |
| if (!siocb->scm) { |
| siocb->scm = &tmp_scm; |
| memset(&tmp_scm, 0, sizeof(tmp_scm)); |
| } |
| |
| err = mutex_lock_interruptible(&u->readlock); |
| if (err) { |
| err = sock_intr_errno(timeo); |
| goto out; |
| } |
| |
| skip = sk_peek_offset(sk, flags); |
| |
| do { |
| int chunk; |
| struct sk_buff *skb; |
| |
| unix_state_lock(sk); |
| skb = skb_peek(&sk->sk_receive_queue); |
| again: |
| if (skb == NULL) { |
| unix_sk(sk)->recursion_level = 0; |
| if (copied >= target) |
| goto unlock; |
| |
| /* |
| * POSIX 1003.1g mandates this order. |
| */ |
| |
| err = sock_error(sk); |
| if (err) |
| goto unlock; |
| if (sk->sk_shutdown & RCV_SHUTDOWN) |
| goto unlock; |
| |
| unix_state_unlock(sk); |
| err = -EAGAIN; |
| if (!timeo) |
| break; |
| mutex_unlock(&u->readlock); |
| |
| timeo = unix_stream_data_wait(sk, timeo); |
| |
| if (signal_pending(current) |
| || mutex_lock_interruptible(&u->readlock)) { |
| err = sock_intr_errno(timeo); |
| goto out; |
| } |
| |
| continue; |
| unlock: |
| unix_state_unlock(sk); |
| break; |
| } |
| |
| if (skip >= skb->len) { |
| skip -= skb->len; |
| skb = skb_peek_next(skb, &sk->sk_receive_queue); |
| goto again; |
| } |
| |
| unix_state_unlock(sk); |
| |
| if (check_creds) { |
| /* Never glue messages from different writers */ |
| if ((UNIXCB(skb).pid != siocb->scm->pid) || |
| (UNIXCB(skb).cred != siocb->scm->cred)) |
| break; |
| } else if (test_bit(SOCK_PASSCRED, &sock->flags)) { |
| /* Copy credentials */ |
| scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred); |
| check_creds = 1; |
| } |
| |
| /* Copy address just once */ |
| if (sunaddr) { |
| unix_copy_addr(msg, skb->sk); |
| sunaddr = NULL; |
| } |
| |
| chunk = min_t(unsigned int, skb->len - skip, size); |
| if (memcpy_toiovec(msg->msg_iov, skb->data + skip, chunk)) { |
| if (copied == 0) |
| copied = -EFAULT; |
| break; |
| } |
| copied += chunk; |
| size -= chunk; |
| |
| /* Mark read part of skb as used */ |
| if (!(flags & MSG_PEEK)) { |
| skb_pull(skb, chunk); |
| |
| sk_peek_offset_bwd(sk, chunk); |
| |
| if (UNIXCB(skb).fp) |
| unix_detach_fds(siocb->scm, skb); |
| |
| if (skb->len) |
| break; |
| |
| skb_unlink(skb, &sk->sk_receive_queue); |
| consume_skb(skb); |
| |
| if (siocb->scm->fp) |
| break; |
| } else { |
| /* It is questionable, see note in unix_dgram_recvmsg. |
| */ |
| if (UNIXCB(skb).fp) |
| siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); |
| |
| sk_peek_offset_fwd(sk, chunk); |
| |
| break; |
| } |
| } while (size); |
| |
| mutex_unlock(&u->readlock); |
| scm_recv(sock, msg, siocb->scm, flags); |
| out: |
| return copied ? : err; |
| } |
| |
| static int unix_shutdown(struct socket *sock, int mode) |
| { |
| struct sock *sk = sock->sk; |
| struct sock *other; |
| |
| mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN); |
| |
| if (!mode) |
| return 0; |
| |
| unix_state_lock(sk); |
| sk->sk_shutdown |= mode; |
| other = unix_peer(sk); |
| if (other) |
| sock_hold(other); |
| unix_state_unlock(sk); |
| sk->sk_state_change(sk); |
| |
| if (other && |
| (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) { |
| |
| int peer_mode = 0; |
| |
| if (mode&RCV_SHUTDOWN) |
| peer_mode |= SEND_SHUTDOWN; |
| if (mode&SEND_SHUTDOWN) |
| peer_mode |= RCV_SHUTDOWN; |
| unix_state_lock(other); |
| other->sk_shutdown |= peer_mode; |
| unix_state_unlock(other); |
| other->sk_state_change(other); |
| if (peer_mode == SHUTDOWN_MASK) |
| sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP); |
| else if (peer_mode & RCV_SHUTDOWN) |
| sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN); |
| } |
| if (other) |
| sock_put(other); |
| |
| return 0; |
| } |
| |
| long unix_inq_len(struct sock *sk) |
| { |
| struct sk_buff *skb; |
| long amount = 0; |
| |
| if (sk->sk_state == TCP_LISTEN) |
| return -EINVAL; |
| |
| spin_lock(&sk->sk_receive_queue.lock); |
| if (sk->sk_type == SOCK_STREAM || |
| sk->sk_type == SOCK_SEQPACKET) { |
| skb_queue_walk(&sk->sk_receive_queue, skb) |
| amount += skb->len; |
| } else { |
| skb = skb_peek(&sk->sk_receive_queue); |
| if (skb) |
| amount = skb->len; |
| } |
| spin_unlock(&sk->sk_receive_queue.lock); |
| |
| return amount; |
| } |
| EXPORT_SYMBOL_GPL(unix_inq_len); |
| |
| long unix_outq_len(struct sock *sk) |
| { |
| return sk_wmem_alloc_get(sk); |
| } |
| EXPORT_SYMBOL_GPL(unix_outq_len); |
| |
| static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
| { |
| struct sock *sk = sock->sk; |
| long amount = 0; |
| int err; |
| |
| switch (cmd) { |
| case SIOCOUTQ: |
| amount = unix_outq_len(sk); |
| err = put_user(amount, (int __user *)arg); |
| break; |
| case SIOCINQ: |
| amount = unix_inq_len(sk); |
| if (amount < 0) |
| err = amount; |
| else |
| err = put_user(amount, (int __user *)arg); |
| break; |
| default: |
| err = -ENOIOCTLCMD; |
| break; |
| } |
| return err; |
| } |
| |
| static unsigned int unix_poll(struct file *file, struct socket *sock, poll_table *wait) |
| { |
| struct sock *sk = sock->sk; |
| unsigned int mask; |
| |
| sock_poll_wait(file, sk_sleep(sk), wait); |
| mask = 0; |
| |
| /* exceptional events? */ |
| if (sk->sk_err) |
| mask |= POLLERR; |
| if (sk->sk_shutdown == SHUTDOWN_MASK) |
| mask |= POLLHUP; |
| if (sk->sk_shutdown & RCV_SHUTDOWN) |
| mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
| |
| /* readable? */ |
| if (!skb_queue_empty(&sk->sk_receive_queue)) |
| mask |= POLLIN | POLLRDNORM; |
| |
| /* Connection-based need to check for termination and startup */ |
| if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) && |
| sk->sk_state == TCP_CLOSE) |
| mask |= POLLHUP; |
| |
| /* |
| * we set writable also when the other side has shut down the |
| * connection. This prevents stuck sockets. |
| */ |
| if (unix_writable(sk)) |
| mask |= POLLOUT | POLLWRNORM | POLLWRBAND; |
| |
| return mask; |
| } |
| |
| static unsigned int unix_dgram_poll(struct file *file, struct socket *sock, |
| poll_table *wait) |
| { |
| struct sock *sk = sock->sk, *other; |
| unsigned int mask, writable; |
| |
| sock_poll_wait(file, sk_sleep(sk), wait); |
| mask = 0; |
| |
| /* exceptional events? */ |
| if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) |
| mask |= POLLERR; |
| if (sk->sk_shutdown & RCV_SHUTDOWN) |
| mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
| if (sk->sk_shutdown == SHUTDOWN_MASK) |
| mask |= POLLHUP; |
| |
| /* readable? */ |
| if (!skb_queue_empty(&sk->sk_receive_queue)) |
| mask |= POLLIN | POLLRDNORM; |
| |
| /* Connection-based need to check for termination and startup */ |
| if (sk->sk_type == SOCK_SEQPACKET) { |
| if (sk->sk_state == TCP_CLOSE) |
| mask |= POLLHUP; |
| /* connection hasn't started yet? */ |
| if (sk->sk_state == TCP_SYN_SENT) |
| return mask; |
| } |
| |
| /* No write status requested, avoid expensive OUT tests. */ |
| if (!(poll_requested_events(wait) & (POLLWRBAND|POLLWRNORM|POLLOUT))) |
| return mask; |
| |
| writable = unix_writable(sk); |
| other = unix_peer_get(sk); |
| if (other) { |
| if (unix_peer(other) != sk) { |
| sock_poll_wait(file, &unix_sk(other)->peer_wait, wait); |
| if (unix_recvq_full(other)) |
| writable = 0; |
| } |
| sock_put(other); |
| } |
| |
| if (writable) |
| mask |= POLLOUT | POLLWRNORM | POLLWRBAND; |
| else |
| set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); |
| |
| return mask; |
| } |
| |
| #ifdef CONFIG_PROC_FS |
| static struct sock *first_unix_socket(int *i) |
| { |
| for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) { |
| if (!hlist_empty(&unix_socket_table[*i])) |
| return __sk_head(&unix_socket_table[*i]); |
| } |
| return NULL; |
| } |
| |
| static struct sock *next_unix_socket(int *i, struct sock *s) |
| { |
| struct sock *next = sk_next(s); |
| /* More in this chain? */ |
| if (next) |
| return next; |
| /* Look for next non-empty chain. */ |
| for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) { |
| if (!hlist_empty(&unix_socket_table[*i])) |
| return __sk_head(&unix_socket_table[*i]); |
| } |
| return NULL; |
| } |
| |
| struct unix_iter_state { |
| struct seq_net_private p; |
| int i; |
| }; |
| |
| static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos) |
| { |
| struct unix_iter_state *iter = seq->private; |
| loff_t off = 0; |
| struct sock *s; |
| |
| for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) { |
| if (sock_net(s) != seq_file_net(seq)) |
| continue; |
| if (off == pos) |
| return s; |
| ++off; |
| } |
| return NULL; |
| } |
| |
| static void *unix_seq_start(struct seq_file *seq, loff_t *pos) |
| __acquires(unix_table_lock) |
| { |
| spin_lock(&unix_table_lock); |
| return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN; |
| } |
| |
| static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
| { |
| struct unix_iter_state *iter = seq->private; |
| struct sock *sk = v; |
| ++*pos; |
| |
| if (v == SEQ_START_TOKEN) |
| sk = first_unix_socket(&iter->i); |
| else |
| sk = next_unix_socket(&iter->i, sk); |
| while (sk && (sock_net(sk) != seq_file_net(seq))) |
| sk = next_unix_socket(&iter->i, sk); |
| return sk; |
| } |
| |
| static void unix_seq_stop(struct seq_file *seq, void *v) |
| __releases(unix_table_lock) |
| { |
| spin_unlock(&unix_table_lock); |
| } |
| |
| static int unix_seq_show(struct seq_file *seq, void *v) |
| { |
| |
| if (v == SEQ_START_TOKEN) |
| seq_puts(seq, "Num RefCount Protocol Flags Type St " |
| "Inode Path\n"); |
| else { |
| struct sock *s = v; |
| struct unix_sock *u = unix_sk(s); |
| unix_state_lock(s); |
| |
| seq_printf(seq, "%pK: %08X %08X %08X %04X %02X %5lu", |
| s, |
| atomic_read(&s->sk_refcnt), |
| 0, |
| s->sk_state == TCP_LISTEN ? __SO_ACCEPTCON : 0, |
| s->sk_type, |
| s->sk_socket ? |
| (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) : |
| (s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING), |
| sock_i_ino(s)); |
| |
| if (u->addr) { |
| int i, len; |
| seq_putc(seq, ' '); |
| |
| i = 0; |
| len = u->addr->len - sizeof(short); |
| if (!UNIX_ABSTRACT(s)) |
| len--; |
| else { |
| seq_putc(seq, '@'); |
| i++; |
| } |
| for ( ; i < len; i++) |
| seq_putc(seq, u->addr->name->sun_path[i]); |
| } |
| unix_state_unlock(s); |
| seq_putc(seq, '\n'); |
| } |
| |
| return 0; |
| } |
| |
| static const struct seq_operations unix_seq_ops = { |
| .start = unix_seq_start, |
| .next = unix_seq_next, |
| .stop = unix_seq_stop, |
| .show = unix_seq_show, |
| }; |
| |
| static int unix_seq_open(struct inode *inode, struct file *file) |
| { |
| return seq_open_net(inode, file, &unix_seq_ops, |
| sizeof(struct unix_iter_state)); |
| } |
| |
| static const struct file_operations unix_seq_fops = { |
| .owner = THIS_MODULE, |
| .open = unix_seq_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release_net, |
| }; |
| |
| #endif |
| |
| static const struct net_proto_family unix_family_ops = { |
| .family = PF_UNIX, |
| .create = unix_create, |
| .owner = THIS_MODULE, |
| }; |
| |
| |
| static int __net_init unix_net_init(struct net *net) |
| { |
| int error = -ENOMEM; |
| |
| net->unx.sysctl_max_dgram_qlen = 10; |
| if (unix_sysctl_register(net)) |
| goto out; |
| |
| #ifdef CONFIG_PROC_FS |
| if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops)) { |
| unix_sysctl_unregister(net); |
| goto out; |
| } |
| #endif |
| error = 0; |
| out: |
| return error; |
| } |
| |
| static void __net_exit unix_net_exit(struct net *net) |
| { |
| unix_sysctl_unregister(net); |
| proc_net_remove(net, "unix"); |
| } |
| |
| static struct pernet_operations unix_net_ops = { |
| .init = unix_net_init, |
| .exit = unix_net_exit, |
| }; |
| |
| static int __init af_unix_init(void) |
| { |
| int rc = -1; |
| struct sk_buff *dummy_skb; |
| |
| BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb)); |
| |
| rc = proto_register(&unix_proto, 1); |
| if (rc != 0) { |
| printk(KERN_CRIT "%s: Cannot create unix_sock SLAB cache!\n", |
| __func__); |
| goto out; |
| } |
| |
| sock_register(&unix_family_ops); |
| register_pernet_subsys(&unix_net_ops); |
| out: |
| return rc; |
| } |
| |
| static void __exit af_unix_exit(void) |
| { |
| sock_unregister(PF_UNIX); |
| proto_unregister(&unix_proto); |
| unregister_pernet_subsys(&unix_net_ops); |
| } |
| |
| /* Earlier than device_initcall() so that other drivers invoking |
| request_module() don't end up in a loop when modprobe tries |
| to use a UNIX socket. But later than subsys_initcall() because |
| we depend on stuff initialised there */ |
| fs_initcall(af_unix_init); |
| module_exit(af_unix_exit); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS_NETPROTO(PF_UNIX); |