xref: /linux/include/net/af_unix.h (revision 249ebf3f65f8530beb2cbfb91bff1d83ba88d23c)
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 unsigned int unix_tot_inflight;
21 void unix_add_edges(struct scm_fp_list *fpl, struct unix_sock *receiver);
22 void unix_del_edges(struct scm_fp_list *fpl);
23 void unix_update_edges(struct unix_sock *receiver);
24 int unix_prepare_fpl(struct scm_fp_list *fpl);
25 void unix_destroy_fpl(struct scm_fp_list *fpl);
26 void unix_gc(void);
27 void wait_for_unix_gc(struct scm_fp_list *fpl);
28 
29 struct unix_vertex {
30 	struct list_head edges;
31 	struct list_head entry;
32 	struct list_head scc_entry;
33 	unsigned long out_degree;
34 	unsigned long index;
35 	unsigned long scc_index;
36 };
37 
38 struct unix_edge {
39 	struct unix_sock *predecessor;
40 	struct unix_sock *successor;
41 	struct list_head vertex_entry;
42 	struct list_head stack_entry;
43 };
44 
45 struct sock *unix_peer_get(struct sock *sk);
46 
47 #define UNIX_HASH_MOD	(256 - 1)
48 #define UNIX_HASH_SIZE	(256 * 2)
49 #define UNIX_HASH_BITS	8
50 
51 struct unix_address {
52 	refcount_t	refcnt;
53 	int		len;
54 	struct sockaddr_un name[];
55 };
56 
57 struct unix_skb_parms {
58 	struct pid		*pid;		/* Skb credentials	*/
59 	kuid_t			uid;
60 	kgid_t			gid;
61 	struct scm_fp_list	*fp;		/* Passed files		*/
62 #ifdef CONFIG_SECURITY_NETWORK
63 	u32			secid;		/* Security ID		*/
64 #endif
65 	u32			consumed;
66 } __randomize_layout;
67 
68 struct scm_stat {
69 	atomic_t nr_fds;
70 	unsigned long nr_unix_fds;
71 };
72 
73 #define UNIXCB(skb)	(*(struct unix_skb_parms *)&((skb)->cb))
74 
75 /* The AF_UNIX socket */
76 struct unix_sock {
77 	/* WARNING: sk has to be the first member */
78 	struct sock		sk;
79 	struct unix_address	*addr;
80 	struct path		path;
81 	struct mutex		iolock, bindlock;
82 	struct sock		*peer;
83 	struct sock		*listener;
84 	struct unix_vertex	*vertex;
85 	spinlock_t		lock;
86 	struct socket_wq	peer_wq;
87 	wait_queue_entry_t	peer_wake;
88 	struct scm_stat		scm_stat;
89 #if IS_ENABLED(CONFIG_AF_UNIX_OOB)
90 	struct sk_buff		*oob_skb;
91 #endif
92 };
93 
94 #define unix_sk(ptr) container_of_const(ptr, struct unix_sock, sk)
95 #define unix_peer(sk) (unix_sk(sk)->peer)
96 
97 #define unix_state_lock(s)	spin_lock(&unix_sk(s)->lock)
98 #define unix_state_unlock(s)	spin_unlock(&unix_sk(s)->lock)
99 enum unix_socket_lock_class {
100 	U_LOCK_NORMAL,
101 	U_LOCK_SECOND,	/* for double locking, see unix_state_double_lock(). */
102 	U_LOCK_DIAG, /* used while dumping icons, see sk_diag_dump_icons(). */
103 	U_LOCK_GC_LISTENER, /* used for listening socket while determining gc
104 			     * candidates to close a small race window.
105 			     */
106 };
107 
108 static inline void unix_state_lock_nested(struct sock *sk,
109 				   enum unix_socket_lock_class subclass)
110 {
111 	spin_lock_nested(&unix_sk(sk)->lock, subclass);
112 }
113 
114 #define peer_wait peer_wq.wait
115 
116 long unix_inq_len(struct sock *sk);
117 long unix_outq_len(struct sock *sk);
118 
119 int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
120 			 int flags);
121 int __unix_stream_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
122 			  int flags);
123 #ifdef CONFIG_SYSCTL
124 int unix_sysctl_register(struct net *net);
125 void unix_sysctl_unregister(struct net *net);
126 #else
127 static inline int unix_sysctl_register(struct net *net) { return 0; }
128 static inline void unix_sysctl_unregister(struct net *net) {}
129 #endif
130 
131 #ifdef CONFIG_BPF_SYSCALL
132 extern struct proto unix_dgram_proto;
133 extern struct proto unix_stream_proto;
134 
135 int unix_dgram_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
136 int unix_stream_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
137 void __init unix_bpf_build_proto(void);
138 #else
139 static inline void __init unix_bpf_build_proto(void)
140 {}
141 #endif
142 #endif
143