xref: /linux/include/net/af_unix.h (revision 4b660dbd9ee2059850fd30e0df420ca7a38a1856)
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 #if IS_ENABLED(CONFIG_UNIX)
12 struct unix_sock *unix_get_socket(struct file *filp);
13 #else
14 static inline struct unix_sock *unix_get_socket(struct file *filp)
15 {
16 	return NULL;
17 }
18 #endif
19 
20 extern spinlock_t unix_gc_lock;
21 extern unsigned int unix_tot_inflight;
22 
23 void unix_inflight(struct user_struct *user, struct file *fp);
24 void unix_notinflight(struct user_struct *user, struct file *fp);
25 void unix_gc(void);
26 void wait_for_unix_gc(struct scm_fp_list *fpl);
27 
28 struct sock *unix_peer_get(struct sock *sk);
29 
30 #define UNIX_HASH_MOD	(256 - 1)
31 #define UNIX_HASH_SIZE	(256 * 2)
32 #define UNIX_HASH_BITS	8
33 
34 struct unix_address {
35 	refcount_t	refcnt;
36 	int		len;
37 	struct sockaddr_un name[];
38 };
39 
40 struct unix_skb_parms {
41 	struct pid		*pid;		/* Skb credentials	*/
42 	kuid_t			uid;
43 	kgid_t			gid;
44 	struct scm_fp_list	*fp;		/* Passed files		*/
45 #ifdef CONFIG_SECURITY_NETWORK
46 	u32			secid;		/* Security ID		*/
47 #endif
48 	u32			consumed;
49 } __randomize_layout;
50 
51 struct scm_stat {
52 	atomic_t nr_fds;
53 };
54 
55 #define UNIXCB(skb)	(*(struct unix_skb_parms *)&((skb)->cb))
56 
57 /* The AF_UNIX socket */
58 struct unix_sock {
59 	/* WARNING: sk has to be the first member */
60 	struct sock		sk;
61 	struct unix_address	*addr;
62 	struct path		path;
63 	struct mutex		iolock, bindlock;
64 	struct sock		*peer;
65 	struct list_head	link;
66 	unsigned long		inflight;
67 	spinlock_t		lock;
68 	unsigned long		gc_flags;
69 #define UNIX_GC_CANDIDATE	0
70 #define UNIX_GC_MAYBE_CYCLE	1
71 	struct socket_wq	peer_wq;
72 	wait_queue_entry_t	peer_wake;
73 	struct scm_stat		scm_stat;
74 #if IS_ENABLED(CONFIG_AF_UNIX_OOB)
75 	struct sk_buff		*oob_skb;
76 #endif
77 };
78 
79 #define unix_sk(ptr) container_of_const(ptr, struct unix_sock, sk)
80 #define unix_peer(sk) (unix_sk(sk)->peer)
81 
82 #define unix_state_lock(s)	spin_lock(&unix_sk(s)->lock)
83 #define unix_state_unlock(s)	spin_unlock(&unix_sk(s)->lock)
84 enum unix_socket_lock_class {
85 	U_LOCK_NORMAL,
86 	U_LOCK_SECOND,	/* for double locking, see unix_state_double_lock(). */
87 	U_LOCK_DIAG, /* used while dumping icons, see sk_diag_dump_icons(). */
88 };
89 
90 static inline void unix_state_lock_nested(struct sock *sk,
91 				   enum unix_socket_lock_class subclass)
92 {
93 	spin_lock_nested(&unix_sk(sk)->lock, subclass);
94 }
95 
96 #define peer_wait peer_wq.wait
97 
98 long unix_inq_len(struct sock *sk);
99 long unix_outq_len(struct sock *sk);
100 
101 int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
102 			 int flags);
103 int __unix_stream_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
104 			  int flags);
105 #ifdef CONFIG_SYSCTL
106 int unix_sysctl_register(struct net *net);
107 void unix_sysctl_unregister(struct net *net);
108 #else
109 static inline int unix_sysctl_register(struct net *net) { return 0; }
110 static inline void unix_sysctl_unregister(struct net *net) {}
111 #endif
112 
113 #ifdef CONFIG_BPF_SYSCALL
114 extern struct proto unix_dgram_proto;
115 extern struct proto unix_stream_proto;
116 
117 int unix_dgram_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
118 int unix_stream_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
119 void __init unix_bpf_build_proto(void);
120 #else
121 static inline void __init unix_bpf_build_proto(void)
122 {}
123 #endif
124 #endif
125