xref: /linux/include/net/af_unix.h (revision a4eb44a6435d6d8f9e642407a4a06f65eb90ca04)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_NET_AFUNIX_H
3 #define __LINUX_NET_AFUNIX_H
4 
5 #include <linux/socket.h>
6 #include <linux/un.h>
7 #include <linux/mutex.h>
8 #include <linux/refcount.h>
9 #include <net/sock.h>
10 
11 void unix_inflight(struct user_struct *user, struct file *fp);
12 void unix_notinflight(struct user_struct *user, struct file *fp);
13 void unix_destruct_scm(struct sk_buff *skb);
14 void unix_gc(void);
15 void wait_for_unix_gc(void);
16 struct sock *unix_get_socket(struct file *filp);
17 struct sock *unix_peer_get(struct sock *sk);
18 
19 #define UNIX_HASH_SIZE	256
20 #define UNIX_HASH_BITS	8
21 
22 extern unsigned int unix_tot_inflight;
23 extern spinlock_t unix_table_locks[2 * UNIX_HASH_SIZE];
24 extern struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE];
25 
26 struct unix_address {
27 	refcount_t	refcnt;
28 	int		len;
29 	struct sockaddr_un name[];
30 };
31 
32 struct unix_skb_parms {
33 	struct pid		*pid;		/* Skb credentials	*/
34 	kuid_t			uid;
35 	kgid_t			gid;
36 	struct scm_fp_list	*fp;		/* Passed files		*/
37 #ifdef CONFIG_SECURITY_NETWORK
38 	u32			secid;		/* Security ID		*/
39 #endif
40 	u32			consumed;
41 } __randomize_layout;
42 
43 struct scm_stat {
44 	atomic_t nr_fds;
45 };
46 
47 #define UNIXCB(skb)	(*(struct unix_skb_parms *)&((skb)->cb))
48 
49 #define unix_state_lock(s)	spin_lock(&unix_sk(s)->lock)
50 #define unix_state_unlock(s)	spin_unlock(&unix_sk(s)->lock)
51 #define unix_state_lock_nested(s) \
52 				spin_lock_nested(&unix_sk(s)->lock, \
53 				SINGLE_DEPTH_NESTING)
54 
55 /* The AF_UNIX socket */
56 struct unix_sock {
57 	/* WARNING: sk has to be the first member */
58 	struct sock		sk;
59 	struct unix_address	*addr;
60 	struct path		path;
61 	struct mutex		iolock, bindlock;
62 	struct sock		*peer;
63 	struct list_head	link;
64 	atomic_long_t		inflight;
65 	spinlock_t		lock;
66 	unsigned long		gc_flags;
67 #define UNIX_GC_CANDIDATE	0
68 #define UNIX_GC_MAYBE_CYCLE	1
69 	struct socket_wq	peer_wq;
70 	wait_queue_entry_t	peer_wake;
71 	struct scm_stat		scm_stat;
72 #if IS_ENABLED(CONFIG_AF_UNIX_OOB)
73 	struct sk_buff		*oob_skb;
74 #endif
75 };
76 
77 static inline struct unix_sock *unix_sk(const struct sock *sk)
78 {
79 	return (struct unix_sock *)sk;
80 }
81 
82 #define peer_wait peer_wq.wait
83 
84 long unix_inq_len(struct sock *sk);
85 long unix_outq_len(struct sock *sk);
86 
87 int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
88 			 int flags);
89 int __unix_stream_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
90 			  int flags);
91 #ifdef CONFIG_SYSCTL
92 int unix_sysctl_register(struct net *net);
93 void unix_sysctl_unregister(struct net *net);
94 #else
95 static inline int unix_sysctl_register(struct net *net) { return 0; }
96 static inline void unix_sysctl_unregister(struct net *net) {}
97 #endif
98 
99 #ifdef CONFIG_BPF_SYSCALL
100 extern struct proto unix_dgram_proto;
101 extern struct proto unix_stream_proto;
102 
103 int unix_dgram_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
104 int unix_stream_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
105 void __init unix_bpf_build_proto(void);
106 #else
107 static inline void __init unix_bpf_build_proto(void)
108 {}
109 #endif
110 #endif
111