forked from Minki/linux
3721 lines
86 KiB
C
3721 lines
86 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* NET4: Implementation of BSD Unix domain sockets.
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*
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* Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk>
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*
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* Fixes:
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* Linus Torvalds : Assorted bug cures.
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* Niibe Yutaka : async I/O support.
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* Carsten Paeth : PF_UNIX check, address fixes.
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* Alan Cox : Limit size of allocated blocks.
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* Alan Cox : Fixed the stupid socketpair bug.
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* Alan Cox : BSD compatibility fine tuning.
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* Alan Cox : Fixed a bug in connect when interrupted.
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* Alan Cox : Sorted out a proper draft version of
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* file descriptor passing hacked up from
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* Mike Shaver's work.
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* Marty Leisner : Fixes to fd passing
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* Nick Nevin : recvmsg bugfix.
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* Alan Cox : Started proper garbage collector
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* Heiko EiBfeldt : Missing verify_area check
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* Alan Cox : Started POSIXisms
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* Andreas Schwab : Replace inode by dentry for proper
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* reference counting
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* Kirk Petersen : Made this a module
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* Christoph Rohland : Elegant non-blocking accept/connect algorithm.
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* Lots of bug fixes.
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* Alexey Kuznetosv : Repaired (I hope) bugs introduces
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* by above two patches.
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* Andrea Arcangeli : If possible we block in connect(2)
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* if the max backlog of the listen socket
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* is been reached. This won't break
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* old apps and it will avoid huge amount
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* of socks hashed (this for unix_gc()
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* performances reasons).
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* Security fix that limits the max
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* number of socks to 2*max_files and
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* the number of skb queueable in the
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* dgram receiver.
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* Artur Skawina : Hash function optimizations
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* Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8)
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* Malcolm Beattie : Set peercred for socketpair
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* Michal Ostrowski : Module initialization cleanup.
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* Arnaldo C. Melo : Remove MOD_{INC,DEC}_USE_COUNT,
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* the core infrastructure is doing that
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* for all net proto families now (2.5.69+)
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*
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* Known differences from reference BSD that was tested:
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*
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* [TO FIX]
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* ECONNREFUSED is not returned from one end of a connected() socket to the
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* other the moment one end closes.
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* fstat() doesn't return st_dev=0, and give the blksize as high water mark
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* and a fake inode identifier (nor the BSD first socket fstat twice bug).
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* [NOT TO FIX]
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* accept() returns a path name even if the connecting socket has closed
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* in the meantime (BSD loses the path and gives up).
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* accept() returns 0 length path for an unbound connector. BSD returns 16
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* and a null first byte in the path (but not for gethost/peername - BSD bug ??)
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* socketpair(...SOCK_RAW..) doesn't panic the kernel.
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* BSD af_unix apparently has connect forgetting to block properly.
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* (need to check this with the POSIX spec in detail)
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*
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* Differences from 2.0.0-11-... (ANK)
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* Bug fixes and improvements.
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* - client shutdown killed server socket.
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* - removed all useless cli/sti pairs.
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*
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* Semantic changes/extensions.
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* - generic control message passing.
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* - SCM_CREDENTIALS control message.
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* - "Abstract" (not FS based) socket bindings.
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* Abstract names are sequences of bytes (not zero terminated)
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* started by 0, so that this name space does not intersect
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* with BSD names.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/signal.h>
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#include <linux/sched/signal.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/stat.h>
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#include <linux/dcache.h>
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#include <linux/namei.h>
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#include <linux/socket.h>
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#include <linux/un.h>
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#include <linux/fcntl.h>
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#include <linux/filter.h>
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#include <linux/termios.h>
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#include <linux/sockios.h>
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#include <linux/net.h>
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#include <linux/in.h>
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <linux/skbuff.h>
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#include <linux/netdevice.h>
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#include <net/net_namespace.h>
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#include <net/sock.h>
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#include <net/tcp_states.h>
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#include <net/af_unix.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <net/scm.h>
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#include <linux/init.h>
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#include <linux/poll.h>
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#include <linux/rtnetlink.h>
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#include <linux/mount.h>
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#include <net/checksum.h>
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#include <linux/security.h>
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#include <linux/freezer.h>
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#include <linux/file.h>
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#include <linux/btf_ids.h>
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#include "scm.h"
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spinlock_t unix_table_locks[2 * UNIX_HASH_SIZE];
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EXPORT_SYMBOL_GPL(unix_table_locks);
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struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE];
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EXPORT_SYMBOL_GPL(unix_socket_table);
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static atomic_long_t unix_nr_socks;
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/* SMP locking strategy:
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* hash table is protected with spinlock unix_table_locks
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* each socket state is protected by separate spin lock.
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*/
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static unsigned int unix_unbound_hash(struct sock *sk)
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{
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unsigned long hash = (unsigned long)sk;
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hash ^= hash >> 16;
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hash ^= hash >> 8;
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hash ^= sk->sk_type;
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return UNIX_HASH_SIZE + (hash & (UNIX_HASH_SIZE - 1));
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}
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static unsigned int unix_bsd_hash(struct inode *i)
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{
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return i->i_ino & (UNIX_HASH_SIZE - 1);
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}
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static unsigned int unix_abstract_hash(struct sockaddr_un *sunaddr,
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int addr_len, int type)
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{
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__wsum csum = csum_partial(sunaddr, addr_len, 0);
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unsigned int hash;
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hash = (__force unsigned int)csum_fold(csum);
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hash ^= hash >> 8;
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hash ^= type;
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return hash & (UNIX_HASH_SIZE - 1);
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}
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static void unix_table_double_lock(unsigned int hash1, unsigned int hash2)
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{
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/* hash1 and hash2 is never the same because
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* one is between 0 and UNIX_HASH_SIZE - 1, and
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* another is between UNIX_HASH_SIZE and UNIX_HASH_SIZE * 2.
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*/
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if (hash1 > hash2)
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swap(hash1, hash2);
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spin_lock(&unix_table_locks[hash1]);
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spin_lock_nested(&unix_table_locks[hash2], SINGLE_DEPTH_NESTING);
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}
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static void unix_table_double_unlock(unsigned int hash1, unsigned int hash2)
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{
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spin_unlock(&unix_table_locks[hash1]);
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spin_unlock(&unix_table_locks[hash2]);
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}
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#ifdef CONFIG_SECURITY_NETWORK
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static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
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{
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UNIXCB(skb).secid = scm->secid;
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}
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static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
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{
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scm->secid = UNIXCB(skb).secid;
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}
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static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb)
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{
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return (scm->secid == UNIXCB(skb).secid);
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}
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#else
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static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
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{ }
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static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
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{ }
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static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb)
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{
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return true;
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}
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#endif /* CONFIG_SECURITY_NETWORK */
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#define unix_peer(sk) (unix_sk(sk)->peer)
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static inline int unix_our_peer(struct sock *sk, struct sock *osk)
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{
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return unix_peer(osk) == sk;
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}
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static inline int unix_may_send(struct sock *sk, struct sock *osk)
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{
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return unix_peer(osk) == NULL || unix_our_peer(sk, osk);
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}
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static inline int unix_recvq_full(const struct sock *sk)
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{
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return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog;
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}
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static inline int unix_recvq_full_lockless(const struct sock *sk)
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{
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return skb_queue_len_lockless(&sk->sk_receive_queue) >
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READ_ONCE(sk->sk_max_ack_backlog);
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}
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struct sock *unix_peer_get(struct sock *s)
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{
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struct sock *peer;
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unix_state_lock(s);
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peer = unix_peer(s);
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if (peer)
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sock_hold(peer);
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unix_state_unlock(s);
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return peer;
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}
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EXPORT_SYMBOL_GPL(unix_peer_get);
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static struct unix_address *unix_create_addr(struct sockaddr_un *sunaddr,
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int addr_len)
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{
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struct unix_address *addr;
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addr = kmalloc(sizeof(*addr) + addr_len, GFP_KERNEL);
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if (!addr)
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return NULL;
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refcount_set(&addr->refcnt, 1);
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addr->len = addr_len;
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memcpy(addr->name, sunaddr, addr_len);
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return addr;
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}
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static inline void unix_release_addr(struct unix_address *addr)
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{
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if (refcount_dec_and_test(&addr->refcnt))
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kfree(addr);
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}
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/*
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* Check unix socket name:
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* - should be not zero length.
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* - if started by not zero, should be NULL terminated (FS object)
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* - if started by zero, it is abstract name.
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*/
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static int unix_validate_addr(struct sockaddr_un *sunaddr, int addr_len)
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{
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if (addr_len <= offsetof(struct sockaddr_un, sun_path) ||
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addr_len > sizeof(*sunaddr))
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return -EINVAL;
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if (sunaddr->sun_family != AF_UNIX)
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return -EINVAL;
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return 0;
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}
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static void unix_mkname_bsd(struct sockaddr_un *sunaddr, int addr_len)
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{
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/* This may look like an off by one error but it is a bit more
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* subtle. 108 is the longest valid AF_UNIX path for a binding.
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* sun_path[108] doesn't as such exist. However in kernel space
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* we are guaranteed that it is a valid memory location in our
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* kernel address buffer because syscall functions always pass
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* a pointer of struct sockaddr_storage which has a bigger buffer
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* than 108.
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*/
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((char *)sunaddr)[addr_len] = 0;
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}
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static void __unix_remove_socket(struct sock *sk)
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{
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sk_del_node_init(sk);
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}
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static void __unix_insert_socket(struct sock *sk)
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{
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WARN_ON(!sk_unhashed(sk));
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sk_add_node(sk, &unix_socket_table[sk->sk_hash]);
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}
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static void __unix_set_addr_hash(struct sock *sk, struct unix_address *addr,
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unsigned int hash)
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{
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__unix_remove_socket(sk);
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smp_store_release(&unix_sk(sk)->addr, addr);
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sk->sk_hash = hash;
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__unix_insert_socket(sk);
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}
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static void unix_remove_socket(struct sock *sk)
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{
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spin_lock(&unix_table_locks[sk->sk_hash]);
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__unix_remove_socket(sk);
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spin_unlock(&unix_table_locks[sk->sk_hash]);
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}
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static void unix_insert_unbound_socket(struct sock *sk)
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{
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spin_lock(&unix_table_locks[sk->sk_hash]);
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__unix_insert_socket(sk);
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spin_unlock(&unix_table_locks[sk->sk_hash]);
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}
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static struct sock *__unix_find_socket_byname(struct net *net,
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struct sockaddr_un *sunname,
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int len, unsigned int hash)
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{
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struct sock *s;
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sk_for_each(s, &unix_socket_table[hash]) {
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struct unix_sock *u = unix_sk(s);
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if (!net_eq(sock_net(s), net))
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continue;
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if (u->addr->len == len &&
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!memcmp(u->addr->name, sunname, len))
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return s;
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}
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return NULL;
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}
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static inline struct sock *unix_find_socket_byname(struct net *net,
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struct sockaddr_un *sunname,
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int len, unsigned int hash)
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{
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struct sock *s;
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spin_lock(&unix_table_locks[hash]);
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s = __unix_find_socket_byname(net, sunname, len, hash);
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if (s)
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sock_hold(s);
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spin_unlock(&unix_table_locks[hash]);
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return s;
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}
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static struct sock *unix_find_socket_byinode(struct inode *i)
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{
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unsigned int hash = unix_bsd_hash(i);
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struct sock *s;
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spin_lock(&unix_table_locks[hash]);
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sk_for_each(s, &unix_socket_table[hash]) {
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struct dentry *dentry = unix_sk(s)->path.dentry;
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if (dentry && d_backing_inode(dentry) == i) {
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sock_hold(s);
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spin_unlock(&unix_table_locks[hash]);
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return s;
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}
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}
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spin_unlock(&unix_table_locks[hash]);
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return NULL;
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}
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/* Support code for asymmetrically connected dgram sockets
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*
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* If a datagram socket is connected to a socket not itself connected
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* to the first socket (eg, /dev/log), clients may only enqueue more
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* messages if the present receive queue of the server socket is not
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* "too large". This means there's a second writeability condition
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* poll and sendmsg need to test. The dgram recv code will do a wake
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* up on the peer_wait wait queue of a socket upon reception of a
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* datagram which needs to be propagated to sleeping would-be writers
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* since these might not have sent anything so far. This can't be
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* accomplished via poll_wait because the lifetime of the server
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* socket might be less than that of its clients if these break their
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* association with it or if the server socket is closed while clients
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* are still connected to it and there's no way to inform "a polling
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* implementation" that it should let go of a certain wait queue
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*
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* In order to propagate a wake up, a wait_queue_entry_t of the client
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* socket is enqueued on the peer_wait queue of the server socket
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* whose wake function does a wake_up on the ordinary client socket
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* wait queue. This connection is established whenever a write (or
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* poll for write) hit the flow control condition and broken when the
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* association to the server socket is dissolved or after a wake up
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* was relayed.
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*/
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static int unix_dgram_peer_wake_relay(wait_queue_entry_t *q, unsigned mode, int flags,
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void *key)
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{
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struct unix_sock *u;
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wait_queue_head_t *u_sleep;
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u = container_of(q, struct unix_sock, peer_wake);
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__remove_wait_queue(&unix_sk(u->peer_wake.private)->peer_wait,
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q);
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u->peer_wake.private = NULL;
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/* relaying can only happen while the wq still exists */
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u_sleep = sk_sleep(&u->sk);
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if (u_sleep)
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wake_up_interruptible_poll(u_sleep, key_to_poll(key));
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return 0;
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}
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static int unix_dgram_peer_wake_connect(struct sock *sk, struct sock *other)
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{
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struct unix_sock *u, *u_other;
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int rc;
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u = unix_sk(sk);
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u_other = unix_sk(other);
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rc = 0;
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spin_lock(&u_other->peer_wait.lock);
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if (!u->peer_wake.private) {
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u->peer_wake.private = other;
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__add_wait_queue(&u_other->peer_wait, &u->peer_wake);
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rc = 1;
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}
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spin_unlock(&u_other->peer_wait.lock);
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return rc;
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}
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static void unix_dgram_peer_wake_disconnect(struct sock *sk,
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struct sock *other)
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{
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struct unix_sock *u, *u_other;
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u = unix_sk(sk);
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u_other = unix_sk(other);
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spin_lock(&u_other->peer_wait.lock);
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if (u->peer_wake.private == other) {
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__remove_wait_queue(&u_other->peer_wait, &u->peer_wake);
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u->peer_wake.private = NULL;
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}
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spin_unlock(&u_other->peer_wait.lock);
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}
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static void unix_dgram_peer_wake_disconnect_wakeup(struct sock *sk,
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struct sock *other)
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{
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unix_dgram_peer_wake_disconnect(sk, other);
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wake_up_interruptible_poll(sk_sleep(sk),
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EPOLLOUT |
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EPOLLWRNORM |
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EPOLLWRBAND);
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}
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/* preconditions:
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* - unix_peer(sk) == other
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* - association is stable
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*/
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static int unix_dgram_peer_wake_me(struct sock *sk, struct sock *other)
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{
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int connected;
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connected = unix_dgram_peer_wake_connect(sk, other);
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/* If other is SOCK_DEAD, we want to make sure we signal
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* POLLOUT, such that a subsequent write() can get a
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* -ECONNREFUSED. Otherwise, if we haven't queued any skbs
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* to other and its full, we will hang waiting for POLLOUT.
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*/
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if (unix_recvq_full(other) && !sock_flag(other, SOCK_DEAD))
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return 1;
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if (connected)
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unix_dgram_peer_wake_disconnect(sk, other);
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return 0;
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}
|
|
|
|
static int unix_writable(const struct sock *sk)
|
|
{
|
|
return sk->sk_state != TCP_LISTEN &&
|
|
(refcount_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 (skwq_has_sleeper(wq))
|
|
wake_up_interruptible_sync_poll(&wq->wait,
|
|
EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND);
|
|
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;
|
|
sk_error_report(other);
|
|
}
|
|
}
|
|
other->sk_state = TCP_CLOSE;
|
|
}
|
|
|
|
static void unix_sock_destructor(struct sock *sk)
|
|
{
|
|
struct unix_sock *u = unix_sk(sk);
|
|
|
|
skb_queue_purge(&sk->sk_receive_queue);
|
|
|
|
#if IS_ENABLED(CONFIG_AF_UNIX_OOB)
|
|
if (u->oob_skb) {
|
|
kfree_skb(u->oob_skb);
|
|
u->oob_skb = NULL;
|
|
}
|
|
#endif
|
|
WARN_ON(refcount_read(&sk->sk_wmem_alloc));
|
|
WARN_ON(!sk_unhashed(sk));
|
|
WARN_ON(sk->sk_socket);
|
|
if (!sock_flag(sk, SOCK_DEAD)) {
|
|
pr_info("Attempt to release alive unix socket: %p\n", sk);
|
|
return;
|
|
}
|
|
|
|
if (u->addr)
|
|
unix_release_addr(u->addr);
|
|
|
|
atomic_long_dec(&unix_nr_socks);
|
|
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
|
|
#ifdef UNIX_REFCNT_DEBUG
|
|
pr_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;
|
|
|
|
skpair = unix_peer(sk);
|
|
unix_peer(sk) = NULL;
|
|
|
|
unix_state_unlock(sk);
|
|
|
|
wake_up_interruptible_all(&u->peer_wait);
|
|
|
|
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);
|
|
}
|
|
|
|
unix_dgram_peer_wake_disconnect(sk, skpair);
|
|
sock_put(skpair); /* It may now die */
|
|
}
|
|
|
|
/* 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 */
|
|
UNIXCB(skb).consumed = skb->len;
|
|
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 us 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)
|
|
{
|
|
const struct cred *old_cred;
|
|
struct pid *old_pid;
|
|
|
|
spin_lock(&sk->sk_peer_lock);
|
|
old_pid = sk->sk_peer_pid;
|
|
old_cred = sk->sk_peer_cred;
|
|
sk->sk_peer_pid = get_pid(task_tgid(current));
|
|
sk->sk_peer_cred = get_current_cred();
|
|
spin_unlock(&sk->sk_peer_lock);
|
|
|
|
put_pid(old_pid);
|
|
put_cred(old_cred);
|
|
}
|
|
|
|
static void copy_peercred(struct sock *sk, struct sock *peersk)
|
|
{
|
|
const struct cred *old_cred;
|
|
struct pid *old_pid;
|
|
|
|
if (sk < peersk) {
|
|
spin_lock(&sk->sk_peer_lock);
|
|
spin_lock_nested(&peersk->sk_peer_lock, SINGLE_DEPTH_NESTING);
|
|
} else {
|
|
spin_lock(&peersk->sk_peer_lock);
|
|
spin_lock_nested(&sk->sk_peer_lock, SINGLE_DEPTH_NESTING);
|
|
}
|
|
old_pid = sk->sk_peer_pid;
|
|
old_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);
|
|
|
|
spin_unlock(&sk->sk_peer_lock);
|
|
spin_unlock(&peersk->sk_peer_lock);
|
|
|
|
put_pid(old_pid);
|
|
put_cred(old_cred);
|
|
}
|
|
|
|
static int unix_listen(struct socket *sock, int backlog)
|
|
{
|
|
int err;
|
|
struct sock *sk = sock->sk;
|
|
struct unix_sock *u = unix_sk(sk);
|
|
|
|
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);
|
|
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, bool);
|
|
static int unix_getname(struct socket *, struct sockaddr *, int);
|
|
static __poll_t unix_poll(struct file *, struct socket *, poll_table *);
|
|
static __poll_t unix_dgram_poll(struct file *, struct socket *,
|
|
poll_table *);
|
|
static int unix_ioctl(struct socket *, unsigned int, unsigned long);
|
|
#ifdef CONFIG_COMPAT
|
|
static int unix_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
|
|
#endif
|
|
static int unix_shutdown(struct socket *, int);
|
|
static int unix_stream_sendmsg(struct socket *, struct msghdr *, size_t);
|
|
static int unix_stream_recvmsg(struct socket *, struct msghdr *, size_t, int);
|
|
static ssize_t unix_stream_sendpage(struct socket *, struct page *, int offset,
|
|
size_t size, int flags);
|
|
static ssize_t unix_stream_splice_read(struct socket *, loff_t *ppos,
|
|
struct pipe_inode_info *, size_t size,
|
|
unsigned int flags);
|
|
static int unix_dgram_sendmsg(struct socket *, struct msghdr *, size_t);
|
|
static int unix_dgram_recvmsg(struct socket *, struct msghdr *, size_t, int);
|
|
static int unix_read_sock(struct sock *sk, read_descriptor_t *desc,
|
|
sk_read_actor_t recv_actor);
|
|
static int unix_stream_read_sock(struct sock *sk, read_descriptor_t *desc,
|
|
sk_read_actor_t recv_actor);
|
|
static int unix_dgram_connect(struct socket *, struct sockaddr *,
|
|
int, int);
|
|
static int unix_seqpacket_sendmsg(struct socket *, struct msghdr *, size_t);
|
|
static int unix_seqpacket_recvmsg(struct socket *, struct msghdr *, size_t,
|
|
int);
|
|
|
|
static int unix_set_peek_off(struct sock *sk, int val)
|
|
{
|
|
struct unix_sock *u = unix_sk(sk);
|
|
|
|
if (mutex_lock_interruptible(&u->iolock))
|
|
return -EINTR;
|
|
|
|
sk->sk_peek_off = val;
|
|
mutex_unlock(&u->iolock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
static void unix_show_fdinfo(struct seq_file *m, struct socket *sock)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct unix_sock *u;
|
|
|
|
if (sk) {
|
|
u = unix_sk(sock->sk);
|
|
seq_printf(m, "scm_fds: %u\n",
|
|
atomic_read(&u->scm_stat.nr_fds));
|
|
}
|
|
}
|
|
#else
|
|
#define unix_show_fdinfo NULL
|
|
#endif
|
|
|
|
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,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = unix_compat_ioctl,
|
|
#endif
|
|
.listen = unix_listen,
|
|
.shutdown = unix_shutdown,
|
|
.sendmsg = unix_stream_sendmsg,
|
|
.recvmsg = unix_stream_recvmsg,
|
|
.read_sock = unix_stream_read_sock,
|
|
.mmap = sock_no_mmap,
|
|
.sendpage = unix_stream_sendpage,
|
|
.splice_read = unix_stream_splice_read,
|
|
.set_peek_off = unix_set_peek_off,
|
|
.show_fdinfo = unix_show_fdinfo,
|
|
};
|
|
|
|
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,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = unix_compat_ioctl,
|
|
#endif
|
|
.listen = sock_no_listen,
|
|
.shutdown = unix_shutdown,
|
|
.sendmsg = unix_dgram_sendmsg,
|
|
.read_sock = unix_read_sock,
|
|
.recvmsg = unix_dgram_recvmsg,
|
|
.mmap = sock_no_mmap,
|
|
.sendpage = sock_no_sendpage,
|
|
.set_peek_off = unix_set_peek_off,
|
|
.show_fdinfo = unix_show_fdinfo,
|
|
};
|
|
|
|
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,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = unix_compat_ioctl,
|
|
#endif
|
|
.listen = unix_listen,
|
|
.shutdown = unix_shutdown,
|
|
.sendmsg = unix_seqpacket_sendmsg,
|
|
.recvmsg = unix_seqpacket_recvmsg,
|
|
.mmap = sock_no_mmap,
|
|
.sendpage = sock_no_sendpage,
|
|
.set_peek_off = unix_set_peek_off,
|
|
.show_fdinfo = unix_show_fdinfo,
|
|
};
|
|
|
|
static void unix_close(struct sock *sk, long timeout)
|
|
{
|
|
/* Nothing to do here, unix socket does not need a ->close().
|
|
* This is merely for sockmap.
|
|
*/
|
|
}
|
|
|
|
static void unix_unhash(struct sock *sk)
|
|
{
|
|
/* Nothing to do here, unix socket does not need a ->unhash().
|
|
* This is merely for sockmap.
|
|
*/
|
|
}
|
|
|
|
struct proto unix_dgram_proto = {
|
|
.name = "UNIX",
|
|
.owner = THIS_MODULE,
|
|
.obj_size = sizeof(struct unix_sock),
|
|
.close = unix_close,
|
|
#ifdef CONFIG_BPF_SYSCALL
|
|
.psock_update_sk_prot = unix_dgram_bpf_update_proto,
|
|
#endif
|
|
};
|
|
|
|
struct proto unix_stream_proto = {
|
|
.name = "UNIX-STREAM",
|
|
.owner = THIS_MODULE,
|
|
.obj_size = sizeof(struct unix_sock),
|
|
.close = unix_close,
|
|
.unhash = unix_unhash,
|
|
#ifdef CONFIG_BPF_SYSCALL
|
|
.psock_update_sk_prot = unix_stream_bpf_update_proto,
|
|
#endif
|
|
};
|
|
|
|
static struct sock *unix_create1(struct net *net, struct socket *sock, int kern, int type)
|
|
{
|
|
struct unix_sock *u;
|
|
struct sock *sk;
|
|
int err;
|
|
|
|
atomic_long_inc(&unix_nr_socks);
|
|
if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files()) {
|
|
err = -ENFILE;
|
|
goto err;
|
|
}
|
|
|
|
if (type == SOCK_STREAM)
|
|
sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_stream_proto, kern);
|
|
else /*dgram and seqpacket */
|
|
sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_dgram_proto, kern);
|
|
|
|
if (!sk) {
|
|
err = -ENOMEM;
|
|
goto err;
|
|
}
|
|
|
|
sock_init_data(sock, sk);
|
|
|
|
sk->sk_hash = unix_unbound_hash(sk);
|
|
sk->sk_allocation = GFP_KERNEL_ACCOUNT;
|
|
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->iolock); /* single task reading lock */
|
|
mutex_init(&u->bindlock); /* single task binding lock */
|
|
init_waitqueue_head(&u->peer_wait);
|
|
init_waitqueue_func_entry(&u->peer_wake, unix_dgram_peer_wake_relay);
|
|
memset(&u->scm_stat, 0, sizeof(struct scm_stat));
|
|
unix_insert_unbound_socket(sk);
|
|
|
|
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
|
|
|
|
return sk;
|
|
|
|
err:
|
|
atomic_long_dec(&unix_nr_socks);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
static int unix_create(struct net *net, struct socket *sock, int protocol,
|
|
int kern)
|
|
{
|
|
struct sock *sk;
|
|
|
|
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;
|
|
fallthrough;
|
|
case SOCK_DGRAM:
|
|
sock->ops = &unix_dgram_ops;
|
|
break;
|
|
case SOCK_SEQPACKET:
|
|
sock->ops = &unix_seqpacket_ops;
|
|
break;
|
|
default:
|
|
return -ESOCKTNOSUPPORT;
|
|
}
|
|
|
|
sk = unix_create1(net, sock, kern, sock->type);
|
|
if (IS_ERR(sk))
|
|
return PTR_ERR(sk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int unix_release(struct socket *sock)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
|
|
if (!sk)
|
|
return 0;
|
|
|
|
sk->sk_prot->close(sk, 0);
|
|
unix_release_sock(sk, 0);
|
|
sock->sk = NULL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct sock *unix_find_bsd(struct net *net, struct sockaddr_un *sunaddr,
|
|
int addr_len, int type)
|
|
{
|
|
struct inode *inode;
|
|
struct path path;
|
|
struct sock *sk;
|
|
int err;
|
|
|
|
unix_mkname_bsd(sunaddr, addr_len);
|
|
err = kern_path(sunaddr->sun_path, LOOKUP_FOLLOW, &path);
|
|
if (err)
|
|
goto fail;
|
|
|
|
err = path_permission(&path, MAY_WRITE);
|
|
if (err)
|
|
goto path_put;
|
|
|
|
err = -ECONNREFUSED;
|
|
inode = d_backing_inode(path.dentry);
|
|
if (!S_ISSOCK(inode->i_mode))
|
|
goto path_put;
|
|
|
|
sk = unix_find_socket_byinode(inode);
|
|
if (!sk)
|
|
goto path_put;
|
|
|
|
err = -EPROTOTYPE;
|
|
if (sk->sk_type == type)
|
|
touch_atime(&path);
|
|
else
|
|
goto sock_put;
|
|
|
|
path_put(&path);
|
|
|
|
return sk;
|
|
|
|
sock_put:
|
|
sock_put(sk);
|
|
path_put:
|
|
path_put(&path);
|
|
fail:
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
static struct sock *unix_find_abstract(struct net *net,
|
|
struct sockaddr_un *sunaddr,
|
|
int addr_len, int type)
|
|
{
|
|
unsigned int hash = unix_abstract_hash(sunaddr, addr_len, type);
|
|
struct dentry *dentry;
|
|
struct sock *sk;
|
|
|
|
sk = unix_find_socket_byname(net, sunaddr, addr_len, hash);
|
|
if (!sk)
|
|
return ERR_PTR(-ECONNREFUSED);
|
|
|
|
dentry = unix_sk(sk)->path.dentry;
|
|
if (dentry)
|
|
touch_atime(&unix_sk(sk)->path);
|
|
|
|
return sk;
|
|
}
|
|
|
|
static struct sock *unix_find_other(struct net *net,
|
|
struct sockaddr_un *sunaddr,
|
|
int addr_len, int type)
|
|
{
|
|
struct sock *sk;
|
|
|
|
if (sunaddr->sun_path[0])
|
|
sk = unix_find_bsd(net, sunaddr, addr_len, type);
|
|
else
|
|
sk = unix_find_abstract(net, sunaddr, addr_len, type);
|
|
|
|
return sk;
|
|
}
|
|
|
|
static int unix_autobind(struct sock *sk)
|
|
{
|
|
unsigned int new_hash, old_hash = sk->sk_hash;
|
|
struct unix_sock *u = unix_sk(sk);
|
|
struct unix_address *addr;
|
|
u32 lastnum, ordernum;
|
|
int err;
|
|
|
|
err = mutex_lock_interruptible(&u->bindlock);
|
|
if (err)
|
|
return err;
|
|
|
|
if (u->addr)
|
|
goto out;
|
|
|
|
err = -ENOMEM;
|
|
addr = kzalloc(sizeof(*addr) +
|
|
offsetof(struct sockaddr_un, sun_path) + 16, GFP_KERNEL);
|
|
if (!addr)
|
|
goto out;
|
|
|
|
addr->len = offsetof(struct sockaddr_un, sun_path) + 6;
|
|
addr->name->sun_family = AF_UNIX;
|
|
refcount_set(&addr->refcnt, 1);
|
|
|
|
ordernum = prandom_u32();
|
|
lastnum = ordernum & 0xFFFFF;
|
|
retry:
|
|
ordernum = (ordernum + 1) & 0xFFFFF;
|
|
sprintf(addr->name->sun_path + 1, "%05x", ordernum);
|
|
|
|
new_hash = unix_abstract_hash(addr->name, addr->len, sk->sk_type);
|
|
unix_table_double_lock(old_hash, new_hash);
|
|
|
|
if (__unix_find_socket_byname(sock_net(sk), addr->name, addr->len,
|
|
new_hash)) {
|
|
unix_table_double_unlock(old_hash, new_hash);
|
|
|
|
/* __unix_find_socket_byname() may take long time if many names
|
|
* are already in use.
|
|
*/
|
|
cond_resched();
|
|
|
|
if (ordernum == lastnum) {
|
|
/* Give up if all names seems to be in use. */
|
|
err = -ENOSPC;
|
|
unix_release_addr(addr);
|
|
goto out;
|
|
}
|
|
|
|
goto retry;
|
|
}
|
|
|
|
__unix_set_addr_hash(sk, addr, new_hash);
|
|
unix_table_double_unlock(old_hash, new_hash);
|
|
err = 0;
|
|
|
|
out: mutex_unlock(&u->bindlock);
|
|
return err;
|
|
}
|
|
|
|
static int unix_bind_bsd(struct sock *sk, struct sockaddr_un *sunaddr,
|
|
int addr_len)
|
|
{
|
|
umode_t mode = S_IFSOCK |
|
|
(SOCK_INODE(sk->sk_socket)->i_mode & ~current_umask());
|
|
unsigned int new_hash, old_hash = sk->sk_hash;
|
|
struct unix_sock *u = unix_sk(sk);
|
|
struct user_namespace *ns; // barf...
|
|
struct unix_address *addr;
|
|
struct dentry *dentry;
|
|
struct path parent;
|
|
int err;
|
|
|
|
unix_mkname_bsd(sunaddr, addr_len);
|
|
addr_len = strlen(sunaddr->sun_path) +
|
|
offsetof(struct sockaddr_un, sun_path) + 1;
|
|
|
|
addr = unix_create_addr(sunaddr, addr_len);
|
|
if (!addr)
|
|
return -ENOMEM;
|
|
|
|
/*
|
|
* Get the parent directory, calculate the hash for last
|
|
* component.
|
|
*/
|
|
dentry = kern_path_create(AT_FDCWD, addr->name->sun_path, &parent, 0);
|
|
if (IS_ERR(dentry)) {
|
|
err = PTR_ERR(dentry);
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* All right, let's create it.
|
|
*/
|
|
ns = mnt_user_ns(parent.mnt);
|
|
err = security_path_mknod(&parent, dentry, mode, 0);
|
|
if (!err)
|
|
err = vfs_mknod(ns, d_inode(parent.dentry), dentry, mode, 0);
|
|
if (err)
|
|
goto out_path;
|
|
err = mutex_lock_interruptible(&u->bindlock);
|
|
if (err)
|
|
goto out_unlink;
|
|
if (u->addr)
|
|
goto out_unlock;
|
|
|
|
new_hash = unix_bsd_hash(d_backing_inode(dentry));
|
|
unix_table_double_lock(old_hash, new_hash);
|
|
u->path.mnt = mntget(parent.mnt);
|
|
u->path.dentry = dget(dentry);
|
|
__unix_set_addr_hash(sk, addr, new_hash);
|
|
unix_table_double_unlock(old_hash, new_hash);
|
|
mutex_unlock(&u->bindlock);
|
|
done_path_create(&parent, dentry);
|
|
return 0;
|
|
|
|
out_unlock:
|
|
mutex_unlock(&u->bindlock);
|
|
err = -EINVAL;
|
|
out_unlink:
|
|
/* failed after successful mknod? unlink what we'd created... */
|
|
vfs_unlink(ns, d_inode(parent.dentry), dentry, NULL);
|
|
out_path:
|
|
done_path_create(&parent, dentry);
|
|
out:
|
|
unix_release_addr(addr);
|
|
return err == -EEXIST ? -EADDRINUSE : err;
|
|
}
|
|
|
|
static int unix_bind_abstract(struct sock *sk, struct sockaddr_un *sunaddr,
|
|
int addr_len)
|
|
{
|
|
unsigned int new_hash, old_hash = sk->sk_hash;
|
|
struct unix_sock *u = unix_sk(sk);
|
|
struct unix_address *addr;
|
|
int err;
|
|
|
|
addr = unix_create_addr(sunaddr, addr_len);
|
|
if (!addr)
|
|
return -ENOMEM;
|
|
|
|
err = mutex_lock_interruptible(&u->bindlock);
|
|
if (err)
|
|
goto out;
|
|
|
|
if (u->addr) {
|
|
err = -EINVAL;
|
|
goto out_mutex;
|
|
}
|
|
|
|
new_hash = unix_abstract_hash(addr->name, addr->len, sk->sk_type);
|
|
unix_table_double_lock(old_hash, new_hash);
|
|
|
|
if (__unix_find_socket_byname(sock_net(sk), addr->name, addr->len,
|
|
new_hash))
|
|
goto out_spin;
|
|
|
|
__unix_set_addr_hash(sk, addr, new_hash);
|
|
unix_table_double_unlock(old_hash, new_hash);
|
|
mutex_unlock(&u->bindlock);
|
|
return 0;
|
|
|
|
out_spin:
|
|
unix_table_double_unlock(old_hash, new_hash);
|
|
err = -EADDRINUSE;
|
|
out_mutex:
|
|
mutex_unlock(&u->bindlock);
|
|
out:
|
|
unix_release_addr(addr);
|
|
return err;
|
|
}
|
|
|
|
static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
|
|
{
|
|
struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
|
|
struct sock *sk = sock->sk;
|
|
int err;
|
|
|
|
if (addr_len == offsetof(struct sockaddr_un, sun_path) &&
|
|
sunaddr->sun_family == AF_UNIX)
|
|
return unix_autobind(sk);
|
|
|
|
err = unix_validate_addr(sunaddr, addr_len);
|
|
if (err)
|
|
return err;
|
|
|
|
if (sunaddr->sun_path[0])
|
|
err = unix_bind_bsd(sk, sunaddr, addr_len);
|
|
else
|
|
err = unix_bind_abstract(sk, sunaddr, addr_len);
|
|
|
|
return err;
|
|
}
|
|
|
|
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;
|
|
int err;
|
|
|
|
err = -EINVAL;
|
|
if (alen < offsetofend(struct sockaddr, sa_family))
|
|
goto out;
|
|
|
|
if (addr->sa_family != AF_UNSPEC) {
|
|
err = unix_validate_addr(sunaddr, alen);
|
|
if (err)
|
|
goto out;
|
|
|
|
if (test_bit(SOCK_PASSCRED, &sock->flags) &&
|
|
!unix_sk(sk)->addr) {
|
|
err = unix_autobind(sk);
|
|
if (err)
|
|
goto out;
|
|
}
|
|
|
|
restart:
|
|
other = unix_find_other(net, sunaddr, alen, sock->type);
|
|
if (IS_ERR(other)) {
|
|
err = PTR_ERR(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;
|
|
|
|
sk->sk_state = other->sk_state = TCP_ESTABLISHED;
|
|
} 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;
|
|
if (!other)
|
|
sk->sk_state = TCP_CLOSE;
|
|
unix_dgram_peer_wake_disconnect_wakeup(sk, old_peer);
|
|
|
|
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)
|
|
__releases(&unix_sk(other)->lock)
|
|
{
|
|
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;
|
|
int st;
|
|
int err;
|
|
long timeo;
|
|
|
|
err = unix_validate_addr(sunaddr, addr_len);
|
|
if (err)
|
|
goto out;
|
|
|
|
if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr) {
|
|
err = unix_autobind(sk);
|
|
if (err)
|
|
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.
|
|
*/
|
|
|
|
/* create new sock for complete connection */
|
|
newsk = unix_create1(sock_net(sk), NULL, 0, sock->type);
|
|
if (IS_ERR(newsk)) {
|
|
err = PTR_ERR(newsk);
|
|
newsk = NULL;
|
|
goto out;
|
|
}
|
|
|
|
err = -ENOMEM;
|
|
|
|
/* 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);
|
|
if (IS_ERR(other)) {
|
|
err = PTR_ERR(other);
|
|
other = NULL;
|
|
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
|
|
*
|
|
* The contents of *(otheru->addr) and otheru->path
|
|
* are seen fully set up here, since we have found
|
|
* otheru in hash under unix_table_locks. Insertion
|
|
* into the hash chain we'd found it in had been done
|
|
* in an earlier critical area protected by unix_table_locks,
|
|
* the same one where we'd set *(otheru->addr) contents,
|
|
* as well as otheru->path and otheru->addr itself.
|
|
*
|
|
* Using smp_store_release() here to set newu->addr
|
|
* is enough to make those stores, as well as stores
|
|
* to newu->path visible to anyone who gets newu->addr
|
|
* by smp_load_acquire(). IOW, the same warranties
|
|
* as for unix_sock instances bound in unix_bind() or
|
|
* in unix_autobind().
|
|
*/
|
|
if (otheru->path.dentry) {
|
|
path_get(&otheru->path);
|
|
newu->path = otheru->path;
|
|
}
|
|
refcount_inc(&otheru->addr->refcnt);
|
|
smp_store_release(&newu->addr, otheru->addr);
|
|
|
|
/* Set credentials */
|
|
copy_peercred(sk, other);
|
|
|
|
sock->state = SS_CONNECTED;
|
|
sk->sk_state = TCP_ESTABLISHED;
|
|
sock_hold(newsk);
|
|
|
|
smp_mb__after_atomic(); /* sock_hold() does an atomic_inc() */
|
|
unix_peer(sk) = newsk;
|
|
|
|
unix_state_unlock(sk);
|
|
|
|
/* take ten 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);
|
|
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);
|
|
|
|
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,
|
|
bool kern)
|
|
{
|
|
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 peer)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct unix_address *addr;
|
|
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);
|
|
}
|
|
|
|
addr = smp_load_acquire(&unix_sk(sk)->addr);
|
|
if (!addr) {
|
|
sunaddr->sun_family = AF_UNIX;
|
|
sunaddr->sun_path[0] = 0;
|
|
err = offsetof(struct sockaddr_un, sun_path);
|
|
} else {
|
|
err = addr->len;
|
|
memcpy(sunaddr, addr->name, addr->len);
|
|
}
|
|
sock_put(sk);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static void unix_peek_fds(struct scm_cookie *scm, struct sk_buff *skb)
|
|
{
|
|
scm->fp = scm_fp_dup(UNIXCB(skb).fp);
|
|
|
|
/*
|
|
* Garbage collection of unix sockets starts by selecting a set of
|
|
* candidate sockets which have reference only from being in flight
|
|
* (total_refs == inflight_refs). This condition is checked once during
|
|
* the candidate collection phase, and candidates are marked as such, so
|
|
* that non-candidates can later be ignored. While inflight_refs is
|
|
* protected by unix_gc_lock, total_refs (file count) is not, hence this
|
|
* is an instantaneous decision.
|
|
*
|
|
* Once a candidate, however, the socket must not be reinstalled into a
|
|
* file descriptor while the garbage collection is in progress.
|
|
*
|
|
* If the above conditions are met, then the directed graph of
|
|
* candidates (*) does not change while unix_gc_lock is held.
|
|
*
|
|
* Any operations that changes the file count through file descriptors
|
|
* (dup, close, sendmsg) does not change the graph since candidates are
|
|
* not installed in fds.
|
|
*
|
|
* Dequeing a candidate via recvmsg would install it into an fd, but
|
|
* that takes unix_gc_lock to decrement the inflight count, so it's
|
|
* serialized with garbage collection.
|
|
*
|
|
* MSG_PEEK is special in that it does not change the inflight count,
|
|
* yet does install the socket into an fd. The following lock/unlock
|
|
* pair is to ensure serialization with garbage collection. It must be
|
|
* done between incrementing the file count and installing the file into
|
|
* an fd.
|
|
*
|
|
* If garbage collection starts after the barrier provided by the
|
|
* lock/unlock, then it will see the elevated refcount and not mark this
|
|
* as a candidate. If a garbage collection is already in progress
|
|
* before the file count was incremented, then the lock/unlock pair will
|
|
* ensure that garbage collection is finished before progressing to
|
|
* installing the fd.
|
|
*
|
|
* (*) A -> B where B is on the queue of A or B is on the queue of C
|
|
* which is on the queue of listening socket A.
|
|
*/
|
|
spin_lock(&unix_gc_lock);
|
|
spin_unlock(&unix_gc_lock);
|
|
}
|
|
|
|
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);
|
|
UNIXCB(skb).uid = scm->creds.uid;
|
|
UNIXCB(skb).gid = scm->creds.gid;
|
|
UNIXCB(skb).fp = NULL;
|
|
unix_get_secdata(scm, skb);
|
|
if (scm->fp && send_fds)
|
|
err = unix_attach_fds(scm, skb);
|
|
|
|
skb->destructor = unix_destruct_scm;
|
|
return err;
|
|
}
|
|
|
|
static bool unix_passcred_enabled(const struct socket *sock,
|
|
const struct sock *other)
|
|
{
|
|
return test_bit(SOCK_PASSCRED, &sock->flags) ||
|
|
!other->sk_socket ||
|
|
test_bit(SOCK_PASSCRED, &other->sk_socket->flags);
|
|
}
|
|
|
|
/*
|
|
* 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).pid)
|
|
return;
|
|
if (unix_passcred_enabled(sock, other)) {
|
|
UNIXCB(skb).pid = get_pid(task_tgid(current));
|
|
current_uid_gid(&UNIXCB(skb).uid, &UNIXCB(skb).gid);
|
|
}
|
|
}
|
|
|
|
static int maybe_init_creds(struct scm_cookie *scm,
|
|
struct socket *socket,
|
|
const struct sock *other)
|
|
{
|
|
int err;
|
|
struct msghdr msg = { .msg_controllen = 0 };
|
|
|
|
err = scm_send(socket, &msg, scm, false);
|
|
if (err)
|
|
return err;
|
|
|
|
if (unix_passcred_enabled(socket, other)) {
|
|
scm->pid = get_pid(task_tgid(current));
|
|
current_uid_gid(&scm->creds.uid, &scm->creds.gid);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static bool unix_skb_scm_eq(struct sk_buff *skb,
|
|
struct scm_cookie *scm)
|
|
{
|
|
const struct unix_skb_parms *u = &UNIXCB(skb);
|
|
|
|
return u->pid == scm->pid &&
|
|
uid_eq(u->uid, scm->creds.uid) &&
|
|
gid_eq(u->gid, scm->creds.gid) &&
|
|
unix_secdata_eq(scm, skb);
|
|
}
|
|
|
|
static void scm_stat_add(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct scm_fp_list *fp = UNIXCB(skb).fp;
|
|
struct unix_sock *u = unix_sk(sk);
|
|
|
|
if (unlikely(fp && fp->count))
|
|
atomic_add(fp->count, &u->scm_stat.nr_fds);
|
|
}
|
|
|
|
static void scm_stat_del(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct scm_fp_list *fp = UNIXCB(skb).fp;
|
|
struct unix_sock *u = unix_sk(sk);
|
|
|
|
if (unlikely(fp && fp->count))
|
|
atomic_sub(fp->count, &u->scm_stat.nr_fds);
|
|
}
|
|
|
|
/*
|
|
* Send AF_UNIX data.
|
|
*/
|
|
|
|
static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
|
|
size_t len)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct net *net = sock_net(sk);
|
|
struct unix_sock *u = unix_sk(sk);
|
|
DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name);
|
|
struct sock *other = NULL;
|
|
int err;
|
|
struct sk_buff *skb;
|
|
long timeo;
|
|
struct scm_cookie scm;
|
|
int data_len = 0;
|
|
int sk_locked;
|
|
|
|
wait_for_unix_gc();
|
|
err = scm_send(sock, msg, &scm, false);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
err = -EOPNOTSUPP;
|
|
if (msg->msg_flags&MSG_OOB)
|
|
goto out;
|
|
|
|
if (msg->msg_namelen) {
|
|
err = unix_validate_addr(sunaddr, msg->msg_namelen);
|
|
if (err)
|
|
goto out;
|
|
} 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(sk);
|
|
if (err)
|
|
goto out;
|
|
}
|
|
|
|
err = -EMSGSIZE;
|
|
if (len > sk->sk_sndbuf - 32)
|
|
goto out;
|
|
|
|
if (len > SKB_MAX_ALLOC) {
|
|
data_len = min_t(size_t,
|
|
len - SKB_MAX_ALLOC,
|
|
MAX_SKB_FRAGS * PAGE_SIZE);
|
|
data_len = PAGE_ALIGN(data_len);
|
|
|
|
BUILD_BUG_ON(SKB_MAX_ALLOC < PAGE_SIZE);
|
|
}
|
|
|
|
skb = sock_alloc_send_pskb(sk, len - data_len, data_len,
|
|
msg->msg_flags & MSG_DONTWAIT, &err,
|
|
PAGE_ALLOC_COSTLY_ORDER);
|
|
if (skb == NULL)
|
|
goto out;
|
|
|
|
err = unix_scm_to_skb(&scm, skb, true);
|
|
if (err < 0)
|
|
goto out_free;
|
|
|
|
skb_put(skb, len - data_len);
|
|
skb->data_len = data_len;
|
|
skb->len = len;
|
|
err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, 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, msg->msg_namelen,
|
|
sk->sk_type);
|
|
if (IS_ERR(other)) {
|
|
err = PTR_ERR(other);
|
|
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;
|
|
}
|
|
|
|
sk_locked = 0;
|
|
unix_state_lock(other);
|
|
restart_locked:
|
|
err = -EPERM;
|
|
if (!unix_may_send(sk, other))
|
|
goto out_unlock;
|
|
|
|
if (unlikely(sock_flag(other, SOCK_DEAD))) {
|
|
/*
|
|
* Check with 1003.1g - what should
|
|
* datagram error
|
|
*/
|
|
unix_state_unlock(other);
|
|
sock_put(other);
|
|
|
|
if (!sk_locked)
|
|
unix_state_lock(sk);
|
|
|
|
err = 0;
|
|
if (unix_peer(sk) == other) {
|
|
unix_peer(sk) = NULL;
|
|
unix_dgram_peer_wake_disconnect_wakeup(sk, other);
|
|
|
|
unix_state_unlock(sk);
|
|
|
|
sk->sk_state = TCP_CLOSE;
|
|
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;
|
|
}
|
|
|
|
/* other == sk && unix_peer(other) != sk if
|
|
* - unix_peer(sk) == NULL, destination address bound to sk
|
|
* - unix_peer(sk) == sk by time of get but disconnected before lock
|
|
*/
|
|
if (other != sk &&
|
|
unlikely(unix_peer(other) != sk &&
|
|
unix_recvq_full_lockless(other))) {
|
|
if (timeo) {
|
|
timeo = unix_wait_for_peer(other, timeo);
|
|
|
|
err = sock_intr_errno(timeo);
|
|
if (signal_pending(current))
|
|
goto out_free;
|
|
|
|
goto restart;
|
|
}
|
|
|
|
if (!sk_locked) {
|
|
unix_state_unlock(other);
|
|
unix_state_double_lock(sk, other);
|
|
}
|
|
|
|
if (unix_peer(sk) != other ||
|
|
unix_dgram_peer_wake_me(sk, other)) {
|
|
err = -EAGAIN;
|
|
sk_locked = 1;
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (!sk_locked) {
|
|
sk_locked = 1;
|
|
goto restart_locked;
|
|
}
|
|
}
|
|
|
|
if (unlikely(sk_locked))
|
|
unix_state_unlock(sk);
|
|
|
|
if (sock_flag(other, SOCK_RCVTSTAMP))
|
|
__net_timestamp(skb);
|
|
maybe_add_creds(skb, sock, other);
|
|
scm_stat_add(other, skb);
|
|
skb_queue_tail(&other->sk_receive_queue, skb);
|
|
unix_state_unlock(other);
|
|
other->sk_data_ready(other);
|
|
sock_put(other);
|
|
scm_destroy(&scm);
|
|
return len;
|
|
|
|
out_unlock:
|
|
if (sk_locked)
|
|
unix_state_unlock(sk);
|
|
unix_state_unlock(other);
|
|
out_free:
|
|
kfree_skb(skb);
|
|
out:
|
|
if (other)
|
|
sock_put(other);
|
|
scm_destroy(&scm);
|
|
return err;
|
|
}
|
|
|
|
/* We use paged skbs for stream sockets, and limit occupancy to 32768
|
|
* bytes, and a minimum of a full page.
|
|
*/
|
|
#define UNIX_SKB_FRAGS_SZ (PAGE_SIZE << get_order(32768))
|
|
|
|
#if IS_ENABLED(CONFIG_AF_UNIX_OOB)
|
|
static int queue_oob(struct socket *sock, struct msghdr *msg, struct sock *other)
|
|
{
|
|
struct unix_sock *ousk = unix_sk(other);
|
|
struct sk_buff *skb;
|
|
int err = 0;
|
|
|
|
skb = sock_alloc_send_skb(sock->sk, 1, msg->msg_flags & MSG_DONTWAIT, &err);
|
|
|
|
if (!skb)
|
|
return err;
|
|
|
|
skb_put(skb, 1);
|
|
err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, 1);
|
|
|
|
if (err) {
|
|
kfree_skb(skb);
|
|
return err;
|
|
}
|
|
|
|
unix_state_lock(other);
|
|
|
|
if (sock_flag(other, SOCK_DEAD) ||
|
|
(other->sk_shutdown & RCV_SHUTDOWN)) {
|
|
unix_state_unlock(other);
|
|
kfree_skb(skb);
|
|
return -EPIPE;
|
|
}
|
|
|
|
maybe_add_creds(skb, sock, other);
|
|
skb_get(skb);
|
|
|
|
if (ousk->oob_skb)
|
|
consume_skb(ousk->oob_skb);
|
|
|
|
WRITE_ONCE(ousk->oob_skb, skb);
|
|
|
|
scm_stat_add(other, skb);
|
|
skb_queue_tail(&other->sk_receive_queue, skb);
|
|
sk_send_sigurg(other);
|
|
unix_state_unlock(other);
|
|
other->sk_data_ready(other);
|
|
|
|
return err;
|
|
}
|
|
#endif
|
|
|
|
static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg,
|
|
size_t len)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct sock *other = NULL;
|
|
int err, size;
|
|
struct sk_buff *skb;
|
|
int sent = 0;
|
|
struct scm_cookie scm;
|
|
bool fds_sent = false;
|
|
int data_len;
|
|
|
|
wait_for_unix_gc();
|
|
err = scm_send(sock, msg, &scm, false);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
err = -EOPNOTSUPP;
|
|
if (msg->msg_flags & MSG_OOB) {
|
|
#if IS_ENABLED(CONFIG_AF_UNIX_OOB)
|
|
if (len)
|
|
len--;
|
|
else
|
|
#endif
|
|
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) {
|
|
size = len - sent;
|
|
|
|
/* Keep two messages in the pipe so it schedules better */
|
|
size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64);
|
|
|
|
/* allow fallback to order-0 allocations */
|
|
size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ);
|
|
|
|
data_len = max_t(int, 0, size - SKB_MAX_HEAD(0));
|
|
|
|
data_len = min_t(size_t, size, PAGE_ALIGN(data_len));
|
|
|
|
skb = sock_alloc_send_pskb(sk, size - data_len, data_len,
|
|
msg->msg_flags & MSG_DONTWAIT, &err,
|
|
get_order(UNIX_SKB_FRAGS_SZ));
|
|
if (!skb)
|
|
goto out_err;
|
|
|
|
/* Only send the fds in the first buffer */
|
|
err = unix_scm_to_skb(&scm, skb, !fds_sent);
|
|
if (err < 0) {
|
|
kfree_skb(skb);
|
|
goto out_err;
|
|
}
|
|
fds_sent = true;
|
|
|
|
skb_put(skb, size - data_len);
|
|
skb->data_len = data_len;
|
|
skb->len = size;
|
|
err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, 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);
|
|
scm_stat_add(other, skb);
|
|
skb_queue_tail(&other->sk_receive_queue, skb);
|
|
unix_state_unlock(other);
|
|
other->sk_data_ready(other);
|
|
sent += size;
|
|
}
|
|
|
|
#if IS_ENABLED(CONFIG_AF_UNIX_OOB)
|
|
if (msg->msg_flags & MSG_OOB) {
|
|
err = queue_oob(sock, msg, other);
|
|
if (err)
|
|
goto out_err;
|
|
sent++;
|
|
}
|
|
#endif
|
|
|
|
scm_destroy(&scm);
|
|
|
|
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(&scm);
|
|
return sent ? : err;
|
|
}
|
|
|
|
static ssize_t unix_stream_sendpage(struct socket *socket, struct page *page,
|
|
int offset, size_t size, int flags)
|
|
{
|
|
int err;
|
|
bool send_sigpipe = false;
|
|
bool init_scm = true;
|
|
struct scm_cookie scm;
|
|
struct sock *other, *sk = socket->sk;
|
|
struct sk_buff *skb, *newskb = NULL, *tail = NULL;
|
|
|
|
if (flags & MSG_OOB)
|
|
return -EOPNOTSUPP;
|
|
|
|
other = unix_peer(sk);
|
|
if (!other || sk->sk_state != TCP_ESTABLISHED)
|
|
return -ENOTCONN;
|
|
|
|
if (false) {
|
|
alloc_skb:
|
|
unix_state_unlock(other);
|
|
mutex_unlock(&unix_sk(other)->iolock);
|
|
newskb = sock_alloc_send_pskb(sk, 0, 0, flags & MSG_DONTWAIT,
|
|
&err, 0);
|
|
if (!newskb)
|
|
goto err;
|
|
}
|
|
|
|
/* we must acquire iolock as we modify already present
|
|
* skbs in the sk_receive_queue and mess with skb->len
|
|
*/
|
|
err = mutex_lock_interruptible(&unix_sk(other)->iolock);
|
|
if (err) {
|
|
err = flags & MSG_DONTWAIT ? -EAGAIN : -ERESTARTSYS;
|
|
goto err;
|
|
}
|
|
|
|
if (sk->sk_shutdown & SEND_SHUTDOWN) {
|
|
err = -EPIPE;
|
|
send_sigpipe = true;
|
|
goto err_unlock;
|
|
}
|
|
|
|
unix_state_lock(other);
|
|
|
|
if (sock_flag(other, SOCK_DEAD) ||
|
|
other->sk_shutdown & RCV_SHUTDOWN) {
|
|
err = -EPIPE;
|
|
send_sigpipe = true;
|
|
goto err_state_unlock;
|
|
}
|
|
|
|
if (init_scm) {
|
|
err = maybe_init_creds(&scm, socket, other);
|
|
if (err)
|
|
goto err_state_unlock;
|
|
init_scm = false;
|
|
}
|
|
|
|
skb = skb_peek_tail(&other->sk_receive_queue);
|
|
if (tail && tail == skb) {
|
|
skb = newskb;
|
|
} else if (!skb || !unix_skb_scm_eq(skb, &scm)) {
|
|
if (newskb) {
|
|
skb = newskb;
|
|
} else {
|
|
tail = skb;
|
|
goto alloc_skb;
|
|
}
|
|
} else if (newskb) {
|
|
/* this is fast path, we don't necessarily need to
|
|
* call to kfree_skb even though with newskb == NULL
|
|
* this - does no harm
|
|
*/
|
|
consume_skb(newskb);
|
|
newskb = NULL;
|
|
}
|
|
|
|
if (skb_append_pagefrags(skb, page, offset, size)) {
|
|
tail = skb;
|
|
goto alloc_skb;
|
|
}
|
|
|
|
skb->len += size;
|
|
skb->data_len += size;
|
|
skb->truesize += size;
|
|
refcount_add(size, &sk->sk_wmem_alloc);
|
|
|
|
if (newskb) {
|
|
err = unix_scm_to_skb(&scm, skb, false);
|
|
if (err)
|
|
goto err_state_unlock;
|
|
spin_lock(&other->sk_receive_queue.lock);
|
|
__skb_queue_tail(&other->sk_receive_queue, newskb);
|
|
spin_unlock(&other->sk_receive_queue.lock);
|
|
}
|
|
|
|
unix_state_unlock(other);
|
|
mutex_unlock(&unix_sk(other)->iolock);
|
|
|
|
other->sk_data_ready(other);
|
|
scm_destroy(&scm);
|
|
return size;
|
|
|
|
err_state_unlock:
|
|
unix_state_unlock(other);
|
|
err_unlock:
|
|
mutex_unlock(&unix_sk(other)->iolock);
|
|
err:
|
|
kfree_skb(newskb);
|
|
if (send_sigpipe && !(flags & MSG_NOSIGNAL))
|
|
send_sig(SIGPIPE, current, 0);
|
|
if (!init_scm)
|
|
scm_destroy(&scm);
|
|
return err;
|
|
}
|
|
|
|
static int unix_seqpacket_sendmsg(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(sock, msg, len);
|
|
}
|
|
|
|
static int unix_seqpacket_recvmsg(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(sock, msg, size, flags);
|
|
}
|
|
|
|
static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
|
|
{
|
|
struct unix_address *addr = smp_load_acquire(&unix_sk(sk)->addr);
|
|
|
|
if (addr) {
|
|
msg->msg_namelen = addr->len;
|
|
memcpy(msg->msg_name, addr->name, addr->len);
|
|
}
|
|
}
|
|
|
|
int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
|
|
int flags)
|
|
{
|
|
struct scm_cookie scm;
|
|
struct socket *sock = sk->sk_socket;
|
|
struct unix_sock *u = unix_sk(sk);
|
|
struct sk_buff *skb, *last;
|
|
long timeo;
|
|
int skip;
|
|
int err;
|
|
|
|
err = -EOPNOTSUPP;
|
|
if (flags&MSG_OOB)
|
|
goto out;
|
|
|
|
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
|
|
|
|
do {
|
|
mutex_lock(&u->iolock);
|
|
|
|
skip = sk_peek_offset(sk, flags);
|
|
skb = __skb_try_recv_datagram(sk, &sk->sk_receive_queue, flags,
|
|
&skip, &err, &last);
|
|
if (skb) {
|
|
if (!(flags & MSG_PEEK))
|
|
scm_stat_del(sk, skb);
|
|
break;
|
|
}
|
|
|
|
mutex_unlock(&u->iolock);
|
|
|
|
if (err != -EAGAIN)
|
|
break;
|
|
} while (timeo &&
|
|
!__skb_wait_for_more_packets(sk, &sk->sk_receive_queue,
|
|
&err, &timeo, last));
|
|
|
|
if (!skb) { /* implies iolock unlocked */
|
|
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;
|
|
}
|
|
|
|
if (wq_has_sleeper(&u->peer_wait))
|
|
wake_up_interruptible_sync_poll(&u->peer_wait,
|
|
EPOLLOUT | EPOLLWRNORM |
|
|
EPOLLWRBAND);
|
|
|
|
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_msg(skb, skip, msg, size);
|
|
if (err)
|
|
goto out_free;
|
|
|
|
if (sock_flag(sk, SOCK_RCVTSTAMP))
|
|
__sock_recv_timestamp(msg, sk, skb);
|
|
|
|
memset(&scm, 0, sizeof(scm));
|
|
|
|
scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
|
|
unix_set_secdata(&scm, skb);
|
|
|
|
if (!(flags & MSG_PEEK)) {
|
|
if (UNIXCB(skb).fp)
|
|
unix_detach_fds(&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)
|
|
unix_peek_fds(&scm, skb);
|
|
}
|
|
err = (flags & MSG_TRUNC) ? skb->len - skip : size;
|
|
|
|
scm_recv(sock, msg, &scm, flags);
|
|
|
|
out_free:
|
|
skb_free_datagram(sk, skb);
|
|
mutex_unlock(&u->iolock);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
|
|
int flags)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
|
|
#ifdef CONFIG_BPF_SYSCALL
|
|
const struct proto *prot = READ_ONCE(sk->sk_prot);
|
|
|
|
if (prot != &unix_dgram_proto)
|
|
return prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
|
|
flags & ~MSG_DONTWAIT, NULL);
|
|
#endif
|
|
return __unix_dgram_recvmsg(sk, msg, size, flags);
|
|
}
|
|
|
|
static int unix_read_sock(struct sock *sk, read_descriptor_t *desc,
|
|
sk_read_actor_t recv_actor)
|
|
{
|
|
int copied = 0;
|
|
|
|
while (1) {
|
|
struct unix_sock *u = unix_sk(sk);
|
|
struct sk_buff *skb;
|
|
int used, err;
|
|
|
|
mutex_lock(&u->iolock);
|
|
skb = skb_recv_datagram(sk, 0, 1, &err);
|
|
mutex_unlock(&u->iolock);
|
|
if (!skb)
|
|
return err;
|
|
|
|
used = recv_actor(desc, skb, 0, skb->len);
|
|
if (used <= 0) {
|
|
if (!copied)
|
|
copied = used;
|
|
kfree_skb(skb);
|
|
break;
|
|
} else if (used <= skb->len) {
|
|
copied += used;
|
|
}
|
|
|
|
kfree_skb(skb);
|
|
if (!desc->count)
|
|
break;
|
|
}
|
|
|
|
return copied;
|
|
}
|
|
|
|
/*
|
|
* Sleep until more data has arrived. But check for races..
|
|
*/
|
|
static long unix_stream_data_wait(struct sock *sk, long timeo,
|
|
struct sk_buff *last, unsigned int last_len,
|
|
bool freezable)
|
|
{
|
|
struct sk_buff *tail;
|
|
DEFINE_WAIT(wait);
|
|
|
|
unix_state_lock(sk);
|
|
|
|
for (;;) {
|
|
prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
|
|
|
|
tail = skb_peek_tail(&sk->sk_receive_queue);
|
|
if (tail != last ||
|
|
(tail && tail->len != last_len) ||
|
|
sk->sk_err ||
|
|
(sk->sk_shutdown & RCV_SHUTDOWN) ||
|
|
signal_pending(current) ||
|
|
!timeo)
|
|
break;
|
|
|
|
sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
|
|
unix_state_unlock(sk);
|
|
if (freezable)
|
|
timeo = freezable_schedule_timeout(timeo);
|
|
else
|
|
timeo = schedule_timeout(timeo);
|
|
unix_state_lock(sk);
|
|
|
|
if (sock_flag(sk, SOCK_DEAD))
|
|
break;
|
|
|
|
sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
|
|
}
|
|
|
|
finish_wait(sk_sleep(sk), &wait);
|
|
unix_state_unlock(sk);
|
|
return timeo;
|
|
}
|
|
|
|
static unsigned int unix_skb_len(const struct sk_buff *skb)
|
|
{
|
|
return skb->len - UNIXCB(skb).consumed;
|
|
}
|
|
|
|
struct unix_stream_read_state {
|
|
int (*recv_actor)(struct sk_buff *, int, int,
|
|
struct unix_stream_read_state *);
|
|
struct socket *socket;
|
|
struct msghdr *msg;
|
|
struct pipe_inode_info *pipe;
|
|
size_t size;
|
|
int flags;
|
|
unsigned int splice_flags;
|
|
};
|
|
|
|
#if IS_ENABLED(CONFIG_AF_UNIX_OOB)
|
|
static int unix_stream_recv_urg(struct unix_stream_read_state *state)
|
|
{
|
|
struct socket *sock = state->socket;
|
|
struct sock *sk = sock->sk;
|
|
struct unix_sock *u = unix_sk(sk);
|
|
int chunk = 1;
|
|
struct sk_buff *oob_skb;
|
|
|
|
mutex_lock(&u->iolock);
|
|
unix_state_lock(sk);
|
|
|
|
if (sock_flag(sk, SOCK_URGINLINE) || !u->oob_skb) {
|
|
unix_state_unlock(sk);
|
|
mutex_unlock(&u->iolock);
|
|
return -EINVAL;
|
|
}
|
|
|
|
oob_skb = u->oob_skb;
|
|
|
|
if (!(state->flags & MSG_PEEK))
|
|
WRITE_ONCE(u->oob_skb, NULL);
|
|
|
|
unix_state_unlock(sk);
|
|
|
|
chunk = state->recv_actor(oob_skb, 0, chunk, state);
|
|
|
|
if (!(state->flags & MSG_PEEK)) {
|
|
UNIXCB(oob_skb).consumed += 1;
|
|
kfree_skb(oob_skb);
|
|
}
|
|
|
|
mutex_unlock(&u->iolock);
|
|
|
|
if (chunk < 0)
|
|
return -EFAULT;
|
|
|
|
state->msg->msg_flags |= MSG_OOB;
|
|
return 1;
|
|
}
|
|
|
|
static struct sk_buff *manage_oob(struct sk_buff *skb, struct sock *sk,
|
|
int flags, int copied)
|
|
{
|
|
struct unix_sock *u = unix_sk(sk);
|
|
|
|
if (!unix_skb_len(skb) && !(flags & MSG_PEEK)) {
|
|
skb_unlink(skb, &sk->sk_receive_queue);
|
|
consume_skb(skb);
|
|
skb = NULL;
|
|
} else {
|
|
if (skb == u->oob_skb) {
|
|
if (copied) {
|
|
skb = NULL;
|
|
} else if (sock_flag(sk, SOCK_URGINLINE)) {
|
|
if (!(flags & MSG_PEEK)) {
|
|
WRITE_ONCE(u->oob_skb, NULL);
|
|
consume_skb(skb);
|
|
}
|
|
} else if (!(flags & MSG_PEEK)) {
|
|
skb_unlink(skb, &sk->sk_receive_queue);
|
|
consume_skb(skb);
|
|
skb = skb_peek(&sk->sk_receive_queue);
|
|
}
|
|
}
|
|
}
|
|
return skb;
|
|
}
|
|
#endif
|
|
|
|
static int unix_stream_read_sock(struct sock *sk, read_descriptor_t *desc,
|
|
sk_read_actor_t recv_actor)
|
|
{
|
|
if (unlikely(sk->sk_state != TCP_ESTABLISHED))
|
|
return -ENOTCONN;
|
|
|
|
return unix_read_sock(sk, desc, recv_actor);
|
|
}
|
|
|
|
static int unix_stream_read_generic(struct unix_stream_read_state *state,
|
|
bool freezable)
|
|
{
|
|
struct scm_cookie scm;
|
|
struct socket *sock = state->socket;
|
|
struct sock *sk = sock->sk;
|
|
struct unix_sock *u = unix_sk(sk);
|
|
int copied = 0;
|
|
int flags = state->flags;
|
|
int noblock = flags & MSG_DONTWAIT;
|
|
bool check_creds = false;
|
|
int target;
|
|
int err = 0;
|
|
long timeo;
|
|
int skip;
|
|
size_t size = state->size;
|
|
unsigned int last_len;
|
|
|
|
if (unlikely(sk->sk_state != TCP_ESTABLISHED)) {
|
|
err = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (unlikely(flags & MSG_OOB)) {
|
|
err = -EOPNOTSUPP;
|
|
#if IS_ENABLED(CONFIG_AF_UNIX_OOB)
|
|
err = unix_stream_recv_urg(state);
|
|
#endif
|
|
goto out;
|
|
}
|
|
|
|
target = sock_rcvlowat(sk, flags & MSG_WAITALL, size);
|
|
timeo = sock_rcvtimeo(sk, noblock);
|
|
|
|
memset(&scm, 0, sizeof(scm));
|
|
|
|
/* Lock the socket to prevent queue disordering
|
|
* while sleeps in memcpy_tomsg
|
|
*/
|
|
mutex_lock(&u->iolock);
|
|
|
|
skip = max(sk_peek_offset(sk, flags), 0);
|
|
|
|
do {
|
|
int chunk;
|
|
bool drop_skb;
|
|
struct sk_buff *skb, *last;
|
|
|
|
redo:
|
|
unix_state_lock(sk);
|
|
if (sock_flag(sk, SOCK_DEAD)) {
|
|
err = -ECONNRESET;
|
|
goto unlock;
|
|
}
|
|
last = skb = skb_peek(&sk->sk_receive_queue);
|
|
last_len = last ? last->len : 0;
|
|
|
|
#if IS_ENABLED(CONFIG_AF_UNIX_OOB)
|
|
if (skb) {
|
|
skb = manage_oob(skb, sk, flags, copied);
|
|
if (!skb) {
|
|
unix_state_unlock(sk);
|
|
if (copied)
|
|
break;
|
|
goto redo;
|
|
}
|
|
}
|
|
#endif
|
|
again:
|
|
if (skb == NULL) {
|
|
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);
|
|
if (!timeo) {
|
|
err = -EAGAIN;
|
|
break;
|
|
}
|
|
|
|
mutex_unlock(&u->iolock);
|
|
|
|
timeo = unix_stream_data_wait(sk, timeo, last,
|
|
last_len, freezable);
|
|
|
|
if (signal_pending(current)) {
|
|
err = sock_intr_errno(timeo);
|
|
scm_destroy(&scm);
|
|
goto out;
|
|
}
|
|
|
|
mutex_lock(&u->iolock);
|
|
goto redo;
|
|
unlock:
|
|
unix_state_unlock(sk);
|
|
break;
|
|
}
|
|
|
|
while (skip >= unix_skb_len(skb)) {
|
|
skip -= unix_skb_len(skb);
|
|
last = skb;
|
|
last_len = skb->len;
|
|
skb = skb_peek_next(skb, &sk->sk_receive_queue);
|
|
if (!skb)
|
|
goto again;
|
|
}
|
|
|
|
unix_state_unlock(sk);
|
|
|
|
if (check_creds) {
|
|
/* Never glue messages from different writers */
|
|
if (!unix_skb_scm_eq(skb, &scm))
|
|
break;
|
|
} else if (test_bit(SOCK_PASSCRED, &sock->flags)) {
|
|
/* Copy credentials */
|
|
scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
|
|
unix_set_secdata(&scm, skb);
|
|
check_creds = true;
|
|
}
|
|
|
|
/* Copy address just once */
|
|
if (state->msg && state->msg->msg_name) {
|
|
DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr,
|
|
state->msg->msg_name);
|
|
unix_copy_addr(state->msg, skb->sk);
|
|
sunaddr = NULL;
|
|
}
|
|
|
|
chunk = min_t(unsigned int, unix_skb_len(skb) - skip, size);
|
|
skb_get(skb);
|
|
chunk = state->recv_actor(skb, skip, chunk, state);
|
|
drop_skb = !unix_skb_len(skb);
|
|
/* skb is only safe to use if !drop_skb */
|
|
consume_skb(skb);
|
|
if (chunk < 0) {
|
|
if (copied == 0)
|
|
copied = -EFAULT;
|
|
break;
|
|
}
|
|
copied += chunk;
|
|
size -= chunk;
|
|
|
|
if (drop_skb) {
|
|
/* the skb was touched by a concurrent reader;
|
|
* we should not expect anything from this skb
|
|
* anymore and assume it invalid - we can be
|
|
* sure it was dropped from the socket queue
|
|
*
|
|
* let's report a short read
|
|
*/
|
|
err = 0;
|
|
break;
|
|
}
|
|
|
|
/* Mark read part of skb as used */
|
|
if (!(flags & MSG_PEEK)) {
|
|
UNIXCB(skb).consumed += chunk;
|
|
|
|
sk_peek_offset_bwd(sk, chunk);
|
|
|
|
if (UNIXCB(skb).fp) {
|
|
scm_stat_del(sk, skb);
|
|
unix_detach_fds(&scm, skb);
|
|
}
|
|
|
|
if (unix_skb_len(skb))
|
|
break;
|
|
|
|
skb_unlink(skb, &sk->sk_receive_queue);
|
|
consume_skb(skb);
|
|
|
|
if (scm.fp)
|
|
break;
|
|
} else {
|
|
/* It is questionable, see note in unix_dgram_recvmsg.
|
|
*/
|
|
if (UNIXCB(skb).fp)
|
|
unix_peek_fds(&scm, skb);
|
|
|
|
sk_peek_offset_fwd(sk, chunk);
|
|
|
|
if (UNIXCB(skb).fp)
|
|
break;
|
|
|
|
skip = 0;
|
|
last = skb;
|
|
last_len = skb->len;
|
|
unix_state_lock(sk);
|
|
skb = skb_peek_next(skb, &sk->sk_receive_queue);
|
|
if (skb)
|
|
goto again;
|
|
unix_state_unlock(sk);
|
|
break;
|
|
}
|
|
} while (size);
|
|
|
|
mutex_unlock(&u->iolock);
|
|
if (state->msg)
|
|
scm_recv(sock, state->msg, &scm, flags);
|
|
else
|
|
scm_destroy(&scm);
|
|
out:
|
|
return copied ? : err;
|
|
}
|
|
|
|
static int unix_stream_read_actor(struct sk_buff *skb,
|
|
int skip, int chunk,
|
|
struct unix_stream_read_state *state)
|
|
{
|
|
int ret;
|
|
|
|
ret = skb_copy_datagram_msg(skb, UNIXCB(skb).consumed + skip,
|
|
state->msg, chunk);
|
|
return ret ?: chunk;
|
|
}
|
|
|
|
int __unix_stream_recvmsg(struct sock *sk, struct msghdr *msg,
|
|
size_t size, int flags)
|
|
{
|
|
struct unix_stream_read_state state = {
|
|
.recv_actor = unix_stream_read_actor,
|
|
.socket = sk->sk_socket,
|
|
.msg = msg,
|
|
.size = size,
|
|
.flags = flags
|
|
};
|
|
|
|
return unix_stream_read_generic(&state, true);
|
|
}
|
|
|
|
static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg,
|
|
size_t size, int flags)
|
|
{
|
|
struct unix_stream_read_state state = {
|
|
.recv_actor = unix_stream_read_actor,
|
|
.socket = sock,
|
|
.msg = msg,
|
|
.size = size,
|
|
.flags = flags
|
|
};
|
|
|
|
#ifdef CONFIG_BPF_SYSCALL
|
|
struct sock *sk = sock->sk;
|
|
const struct proto *prot = READ_ONCE(sk->sk_prot);
|
|
|
|
if (prot != &unix_stream_proto)
|
|
return prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
|
|
flags & ~MSG_DONTWAIT, NULL);
|
|
#endif
|
|
return unix_stream_read_generic(&state, true);
|
|
}
|
|
|
|
static int unix_stream_splice_actor(struct sk_buff *skb,
|
|
int skip, int chunk,
|
|
struct unix_stream_read_state *state)
|
|
{
|
|
return skb_splice_bits(skb, state->socket->sk,
|
|
UNIXCB(skb).consumed + skip,
|
|
state->pipe, chunk, state->splice_flags);
|
|
}
|
|
|
|
static ssize_t unix_stream_splice_read(struct socket *sock, loff_t *ppos,
|
|
struct pipe_inode_info *pipe,
|
|
size_t size, unsigned int flags)
|
|
{
|
|
struct unix_stream_read_state state = {
|
|
.recv_actor = unix_stream_splice_actor,
|
|
.socket = sock,
|
|
.pipe = pipe,
|
|
.size = size,
|
|
.splice_flags = flags,
|
|
};
|
|
|
|
if (unlikely(*ppos))
|
|
return -ESPIPE;
|
|
|
|
if (sock->file->f_flags & O_NONBLOCK ||
|
|
flags & SPLICE_F_NONBLOCK)
|
|
state.flags = MSG_DONTWAIT;
|
|
|
|
return unix_stream_read_generic(&state, false);
|
|
}
|
|
|
|
static int unix_shutdown(struct socket *sock, int mode)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct sock *other;
|
|
|
|
if (mode < SHUT_RD || mode > SHUT_RDWR)
|
|
return -EINVAL;
|
|
/* This maps:
|
|
* SHUT_RD (0) -> RCV_SHUTDOWN (1)
|
|
* SHUT_WR (1) -> SEND_SHUTDOWN (2)
|
|
* SHUT_RDWR (2) -> SHUTDOWN_MASK (3)
|
|
*/
|
|
++mode;
|
|
|
|
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;
|
|
const struct proto *prot = READ_ONCE(other->sk_prot);
|
|
|
|
if (prot->unhash)
|
|
prot->unhash(other);
|
|
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 += unix_skb_len(skb);
|
|
} 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_open_file(struct sock *sk)
|
|
{
|
|
struct path path;
|
|
struct file *f;
|
|
int fd;
|
|
|
|
if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
|
|
return -EPERM;
|
|
|
|
if (!smp_load_acquire(&unix_sk(sk)->addr))
|
|
return -ENOENT;
|
|
|
|
path = unix_sk(sk)->path;
|
|
if (!path.dentry)
|
|
return -ENOENT;
|
|
|
|
path_get(&path);
|
|
|
|
fd = get_unused_fd_flags(O_CLOEXEC);
|
|
if (fd < 0)
|
|
goto out;
|
|
|
|
f = dentry_open(&path, O_PATH, current_cred());
|
|
if (IS_ERR(f)) {
|
|
put_unused_fd(fd);
|
|
fd = PTR_ERR(f);
|
|
goto out;
|
|
}
|
|
|
|
fd_install(fd, f);
|
|
out:
|
|
path_put(&path);
|
|
|
|
return fd;
|
|
}
|
|
|
|
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;
|
|
case SIOCUNIXFILE:
|
|
err = unix_open_file(sk);
|
|
break;
|
|
#if IS_ENABLED(CONFIG_AF_UNIX_OOB)
|
|
case SIOCATMARK:
|
|
{
|
|
struct sk_buff *skb;
|
|
int answ = 0;
|
|
|
|
skb = skb_peek(&sk->sk_receive_queue);
|
|
if (skb && skb == READ_ONCE(unix_sk(sk)->oob_skb))
|
|
answ = 1;
|
|
err = put_user(answ, (int __user *)arg);
|
|
}
|
|
break;
|
|
#endif
|
|
default:
|
|
err = -ENOIOCTLCMD;
|
|
break;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static int unix_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
|
|
{
|
|
return unix_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
|
|
}
|
|
#endif
|
|
|
|
static __poll_t unix_poll(struct file *file, struct socket *sock, poll_table *wait)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
__poll_t mask;
|
|
|
|
sock_poll_wait(file, sock, wait);
|
|
mask = 0;
|
|
|
|
/* exceptional events? */
|
|
if (sk->sk_err)
|
|
mask |= EPOLLERR;
|
|
if (sk->sk_shutdown == SHUTDOWN_MASK)
|
|
mask |= EPOLLHUP;
|
|
if (sk->sk_shutdown & RCV_SHUTDOWN)
|
|
mask |= EPOLLRDHUP | EPOLLIN | EPOLLRDNORM;
|
|
|
|
/* readable? */
|
|
if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
|
|
mask |= EPOLLIN | EPOLLRDNORM;
|
|
if (sk_is_readable(sk))
|
|
mask |= EPOLLIN | EPOLLRDNORM;
|
|
#if IS_ENABLED(CONFIG_AF_UNIX_OOB)
|
|
if (READ_ONCE(unix_sk(sk)->oob_skb))
|
|
mask |= EPOLLPRI;
|
|
#endif
|
|
|
|
/* 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 |= EPOLLHUP;
|
|
|
|
/*
|
|
* we set writable also when the other side has shut down the
|
|
* connection. This prevents stuck sockets.
|
|
*/
|
|
if (unix_writable(sk))
|
|
mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
|
|
|
|
return mask;
|
|
}
|
|
|
|
static __poll_t unix_dgram_poll(struct file *file, struct socket *sock,
|
|
poll_table *wait)
|
|
{
|
|
struct sock *sk = sock->sk, *other;
|
|
unsigned int writable;
|
|
__poll_t mask;
|
|
|
|
sock_poll_wait(file, sock, wait);
|
|
mask = 0;
|
|
|
|
/* exceptional events? */
|
|
if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
|
|
mask |= EPOLLERR |
|
|
(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);
|
|
|
|
if (sk->sk_shutdown & RCV_SHUTDOWN)
|
|
mask |= EPOLLRDHUP | EPOLLIN | EPOLLRDNORM;
|
|
if (sk->sk_shutdown == SHUTDOWN_MASK)
|
|
mask |= EPOLLHUP;
|
|
|
|
/* readable? */
|
|
if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
|
|
mask |= EPOLLIN | EPOLLRDNORM;
|
|
if (sk_is_readable(sk))
|
|
mask |= EPOLLIN | EPOLLRDNORM;
|
|
|
|
/* Connection-based need to check for termination and startup */
|
|
if (sk->sk_type == SOCK_SEQPACKET) {
|
|
if (sk->sk_state == TCP_CLOSE)
|
|
mask |= EPOLLHUP;
|
|
/* 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) & (EPOLLWRBAND|EPOLLWRNORM|EPOLLOUT)))
|
|
return mask;
|
|
|
|
writable = unix_writable(sk);
|
|
if (writable) {
|
|
unix_state_lock(sk);
|
|
|
|
other = unix_peer(sk);
|
|
if (other && unix_peer(other) != sk &&
|
|
unix_recvq_full_lockless(other) &&
|
|
unix_dgram_peer_wake_me(sk, other))
|
|
writable = 0;
|
|
|
|
unix_state_unlock(sk);
|
|
}
|
|
|
|
if (writable)
|
|
mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
|
|
else
|
|
sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
|
|
|
|
return mask;
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
|
|
#define BUCKET_SPACE (BITS_PER_LONG - (UNIX_HASH_BITS + 1) - 1)
|
|
|
|
#define get_bucket(x) ((x) >> BUCKET_SPACE)
|
|
#define get_offset(x) ((x) & ((1UL << BUCKET_SPACE) - 1))
|
|
#define set_bucket_offset(b, o) ((b) << BUCKET_SPACE | (o))
|
|
|
|
static struct sock *unix_from_bucket(struct seq_file *seq, loff_t *pos)
|
|
{
|
|
unsigned long offset = get_offset(*pos);
|
|
unsigned long bucket = get_bucket(*pos);
|
|
struct sock *sk;
|
|
unsigned long count = 0;
|
|
|
|
for (sk = sk_head(&unix_socket_table[bucket]); sk; sk = sk_next(sk)) {
|
|
if (sock_net(sk) != seq_file_net(seq))
|
|
continue;
|
|
if (++count == offset)
|
|
break;
|
|
}
|
|
|
|
return sk;
|
|
}
|
|
|
|
static struct sock *unix_get_first(struct seq_file *seq, loff_t *pos)
|
|
{
|
|
unsigned long bucket = get_bucket(*pos);
|
|
struct sock *sk;
|
|
|
|
while (bucket < ARRAY_SIZE(unix_socket_table)) {
|
|
spin_lock(&unix_table_locks[bucket]);
|
|
|
|
sk = unix_from_bucket(seq, pos);
|
|
if (sk)
|
|
return sk;
|
|
|
|
spin_unlock(&unix_table_locks[bucket]);
|
|
|
|
*pos = set_bucket_offset(++bucket, 1);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static struct sock *unix_get_next(struct seq_file *seq, struct sock *sk,
|
|
loff_t *pos)
|
|
{
|
|
unsigned long bucket = get_bucket(*pos);
|
|
|
|
for (sk = sk_next(sk); sk; sk = sk_next(sk))
|
|
if (sock_net(sk) == seq_file_net(seq))
|
|
return sk;
|
|
|
|
spin_unlock(&unix_table_locks[bucket]);
|
|
|
|
*pos = set_bucket_offset(++bucket, 1);
|
|
|
|
return unix_get_first(seq, pos);
|
|
}
|
|
|
|
static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
|
|
{
|
|
if (!*pos)
|
|
return SEQ_START_TOKEN;
|
|
|
|
return unix_get_first(seq, pos);
|
|
}
|
|
|
|
static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
|
{
|
|
++*pos;
|
|
|
|
if (v == SEQ_START_TOKEN)
|
|
return unix_get_first(seq, pos);
|
|
|
|
return unix_get_next(seq, v, pos);
|
|
}
|
|
|
|
static void unix_seq_stop(struct seq_file *seq, void *v)
|
|
{
|
|
struct sock *sk = v;
|
|
|
|
if (sk)
|
|
spin_unlock(&unix_table_locks[sk->sk_hash]);
|
|
}
|
|
|
|
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,
|
|
refcount_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) { // under unix_table_locks here
|
|
int i, len;
|
|
seq_putc(seq, ' ');
|
|
|
|
i = 0;
|
|
len = u->addr->len -
|
|
offsetof(struct sockaddr_un, sun_path);
|
|
if (u->addr->name->sun_path[0]) {
|
|
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,
|
|
};
|
|
|
|
#if IS_BUILTIN(CONFIG_UNIX) && defined(CONFIG_BPF_SYSCALL)
|
|
struct bpf_unix_iter_state {
|
|
struct seq_net_private p;
|
|
unsigned int cur_sk;
|
|
unsigned int end_sk;
|
|
unsigned int max_sk;
|
|
struct sock **batch;
|
|
bool st_bucket_done;
|
|
};
|
|
|
|
struct bpf_iter__unix {
|
|
__bpf_md_ptr(struct bpf_iter_meta *, meta);
|
|
__bpf_md_ptr(struct unix_sock *, unix_sk);
|
|
uid_t uid __aligned(8);
|
|
};
|
|
|
|
static int unix_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta,
|
|
struct unix_sock *unix_sk, uid_t uid)
|
|
{
|
|
struct bpf_iter__unix ctx;
|
|
|
|
meta->seq_num--; /* skip SEQ_START_TOKEN */
|
|
ctx.meta = meta;
|
|
ctx.unix_sk = unix_sk;
|
|
ctx.uid = uid;
|
|
return bpf_iter_run_prog(prog, &ctx);
|
|
}
|
|
|
|
static int bpf_iter_unix_hold_batch(struct seq_file *seq, struct sock *start_sk)
|
|
|
|
{
|
|
struct bpf_unix_iter_state *iter = seq->private;
|
|
unsigned int expected = 1;
|
|
struct sock *sk;
|
|
|
|
sock_hold(start_sk);
|
|
iter->batch[iter->end_sk++] = start_sk;
|
|
|
|
for (sk = sk_next(start_sk); sk; sk = sk_next(sk)) {
|
|
if (sock_net(sk) != seq_file_net(seq))
|
|
continue;
|
|
|
|
if (iter->end_sk < iter->max_sk) {
|
|
sock_hold(sk);
|
|
iter->batch[iter->end_sk++] = sk;
|
|
}
|
|
|
|
expected++;
|
|
}
|
|
|
|
spin_unlock(&unix_table_locks[start_sk->sk_hash]);
|
|
|
|
return expected;
|
|
}
|
|
|
|
static void bpf_iter_unix_put_batch(struct bpf_unix_iter_state *iter)
|
|
{
|
|
while (iter->cur_sk < iter->end_sk)
|
|
sock_put(iter->batch[iter->cur_sk++]);
|
|
}
|
|
|
|
static int bpf_iter_unix_realloc_batch(struct bpf_unix_iter_state *iter,
|
|
unsigned int new_batch_sz)
|
|
{
|
|
struct sock **new_batch;
|
|
|
|
new_batch = kvmalloc(sizeof(*new_batch) * new_batch_sz,
|
|
GFP_USER | __GFP_NOWARN);
|
|
if (!new_batch)
|
|
return -ENOMEM;
|
|
|
|
bpf_iter_unix_put_batch(iter);
|
|
kvfree(iter->batch);
|
|
iter->batch = new_batch;
|
|
iter->max_sk = new_batch_sz;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct sock *bpf_iter_unix_batch(struct seq_file *seq,
|
|
loff_t *pos)
|
|
{
|
|
struct bpf_unix_iter_state *iter = seq->private;
|
|
unsigned int expected;
|
|
bool resized = false;
|
|
struct sock *sk;
|
|
|
|
if (iter->st_bucket_done)
|
|
*pos = set_bucket_offset(get_bucket(*pos) + 1, 1);
|
|
|
|
again:
|
|
/* Get a new batch */
|
|
iter->cur_sk = 0;
|
|
iter->end_sk = 0;
|
|
|
|
sk = unix_get_first(seq, pos);
|
|
if (!sk)
|
|
return NULL; /* Done */
|
|
|
|
expected = bpf_iter_unix_hold_batch(seq, sk);
|
|
|
|
if (iter->end_sk == expected) {
|
|
iter->st_bucket_done = true;
|
|
return sk;
|
|
}
|
|
|
|
if (!resized && !bpf_iter_unix_realloc_batch(iter, expected * 3 / 2)) {
|
|
resized = true;
|
|
goto again;
|
|
}
|
|
|
|
return sk;
|
|
}
|
|
|
|
static void *bpf_iter_unix_seq_start(struct seq_file *seq, loff_t *pos)
|
|
{
|
|
if (!*pos)
|
|
return SEQ_START_TOKEN;
|
|
|
|
/* bpf iter does not support lseek, so it always
|
|
* continue from where it was stop()-ped.
|
|
*/
|
|
return bpf_iter_unix_batch(seq, pos);
|
|
}
|
|
|
|
static void *bpf_iter_unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
|
{
|
|
struct bpf_unix_iter_state *iter = seq->private;
|
|
struct sock *sk;
|
|
|
|
/* Whenever seq_next() is called, the iter->cur_sk is
|
|
* done with seq_show(), so advance to the next sk in
|
|
* the batch.
|
|
*/
|
|
if (iter->cur_sk < iter->end_sk)
|
|
sock_put(iter->batch[iter->cur_sk++]);
|
|
|
|
++*pos;
|
|
|
|
if (iter->cur_sk < iter->end_sk)
|
|
sk = iter->batch[iter->cur_sk];
|
|
else
|
|
sk = bpf_iter_unix_batch(seq, pos);
|
|
|
|
return sk;
|
|
}
|
|
|
|
static int bpf_iter_unix_seq_show(struct seq_file *seq, void *v)
|
|
{
|
|
struct bpf_iter_meta meta;
|
|
struct bpf_prog *prog;
|
|
struct sock *sk = v;
|
|
uid_t uid;
|
|
bool slow;
|
|
int ret;
|
|
|
|
if (v == SEQ_START_TOKEN)
|
|
return 0;
|
|
|
|
slow = lock_sock_fast(sk);
|
|
|
|
if (unlikely(sk_unhashed(sk))) {
|
|
ret = SEQ_SKIP;
|
|
goto unlock;
|
|
}
|
|
|
|
uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk));
|
|
meta.seq = seq;
|
|
prog = bpf_iter_get_info(&meta, false);
|
|
ret = unix_prog_seq_show(prog, &meta, v, uid);
|
|
unlock:
|
|
unlock_sock_fast(sk, slow);
|
|
return ret;
|
|
}
|
|
|
|
static void bpf_iter_unix_seq_stop(struct seq_file *seq, void *v)
|
|
{
|
|
struct bpf_unix_iter_state *iter = seq->private;
|
|
struct bpf_iter_meta meta;
|
|
struct bpf_prog *prog;
|
|
|
|
if (!v) {
|
|
meta.seq = seq;
|
|
prog = bpf_iter_get_info(&meta, true);
|
|
if (prog)
|
|
(void)unix_prog_seq_show(prog, &meta, v, 0);
|
|
}
|
|
|
|
if (iter->cur_sk < iter->end_sk)
|
|
bpf_iter_unix_put_batch(iter);
|
|
}
|
|
|
|
static const struct seq_operations bpf_iter_unix_seq_ops = {
|
|
.start = bpf_iter_unix_seq_start,
|
|
.next = bpf_iter_unix_seq_next,
|
|
.stop = bpf_iter_unix_seq_stop,
|
|
.show = bpf_iter_unix_seq_show,
|
|
};
|
|
#endif
|
|
#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_create_net("unix", 0, net->proc_net, &unix_seq_ops,
|
|
sizeof(struct seq_net_private))) {
|
|
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);
|
|
remove_proc_entry("unix", net->proc_net);
|
|
}
|
|
|
|
static struct pernet_operations unix_net_ops = {
|
|
.init = unix_net_init,
|
|
.exit = unix_net_exit,
|
|
};
|
|
|
|
#if IS_BUILTIN(CONFIG_UNIX) && defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
|
|
DEFINE_BPF_ITER_FUNC(unix, struct bpf_iter_meta *meta,
|
|
struct unix_sock *unix_sk, uid_t uid)
|
|
|
|
#define INIT_BATCH_SZ 16
|
|
|
|
static int bpf_iter_init_unix(void *priv_data, struct bpf_iter_aux_info *aux)
|
|
{
|
|
struct bpf_unix_iter_state *iter = priv_data;
|
|
int err;
|
|
|
|
err = bpf_iter_init_seq_net(priv_data, aux);
|
|
if (err)
|
|
return err;
|
|
|
|
err = bpf_iter_unix_realloc_batch(iter, INIT_BATCH_SZ);
|
|
if (err) {
|
|
bpf_iter_fini_seq_net(priv_data);
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void bpf_iter_fini_unix(void *priv_data)
|
|
{
|
|
struct bpf_unix_iter_state *iter = priv_data;
|
|
|
|
bpf_iter_fini_seq_net(priv_data);
|
|
kvfree(iter->batch);
|
|
}
|
|
|
|
static const struct bpf_iter_seq_info unix_seq_info = {
|
|
.seq_ops = &bpf_iter_unix_seq_ops,
|
|
.init_seq_private = bpf_iter_init_unix,
|
|
.fini_seq_private = bpf_iter_fini_unix,
|
|
.seq_priv_size = sizeof(struct bpf_unix_iter_state),
|
|
};
|
|
|
|
static const struct bpf_func_proto *
|
|
bpf_iter_unix_get_func_proto(enum bpf_func_id func_id,
|
|
const struct bpf_prog *prog)
|
|
{
|
|
switch (func_id) {
|
|
case BPF_FUNC_setsockopt:
|
|
return &bpf_sk_setsockopt_proto;
|
|
case BPF_FUNC_getsockopt:
|
|
return &bpf_sk_getsockopt_proto;
|
|
default:
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
static struct bpf_iter_reg unix_reg_info = {
|
|
.target = "unix",
|
|
.ctx_arg_info_size = 1,
|
|
.ctx_arg_info = {
|
|
{ offsetof(struct bpf_iter__unix, unix_sk),
|
|
PTR_TO_BTF_ID_OR_NULL },
|
|
},
|
|
.get_func_proto = bpf_iter_unix_get_func_proto,
|
|
.seq_info = &unix_seq_info,
|
|
};
|
|
|
|
static void __init bpf_iter_register(void)
|
|
{
|
|
unix_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_UNIX];
|
|
if (bpf_iter_reg_target(&unix_reg_info))
|
|
pr_warn("Warning: could not register bpf iterator unix\n");
|
|
}
|
|
#endif
|
|
|
|
static int __init af_unix_init(void)
|
|
{
|
|
int i, rc = -1;
|
|
|
|
BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof_field(struct sk_buff, cb));
|
|
|
|
for (i = 0; i < 2 * UNIX_HASH_SIZE; i++)
|
|
spin_lock_init(&unix_table_locks[i]);
|
|
|
|
rc = proto_register(&unix_dgram_proto, 1);
|
|
if (rc != 0) {
|
|
pr_crit("%s: Cannot create unix_sock SLAB cache!\n", __func__);
|
|
goto out;
|
|
}
|
|
|
|
rc = proto_register(&unix_stream_proto, 1);
|
|
if (rc != 0) {
|
|
pr_crit("%s: Cannot create unix_sock SLAB cache!\n", __func__);
|
|
goto out;
|
|
}
|
|
|
|
sock_register(&unix_family_ops);
|
|
register_pernet_subsys(&unix_net_ops);
|
|
unix_bpf_build_proto();
|
|
|
|
#if IS_BUILTIN(CONFIG_UNIX) && defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
|
|
bpf_iter_register();
|
|
#endif
|
|
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
static void __exit af_unix_exit(void)
|
|
{
|
|
sock_unregister(PF_UNIX);
|
|
proto_unregister(&unix_dgram_proto);
|
|
proto_unregister(&unix_stream_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);
|