FreeBSD/Linux Kernel Cross Reference
sys/sys/unpcb.h
1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * @(#)unpcb.h 8.1 (Berkeley) 6/2/93
32 * $FreeBSD: releng/12.0/sys/sys/unpcb.h 337222 2018-08-03 01:37:00Z asomers $
33 */
34
35 #ifndef _SYS_UNPCB_H_
36 #define _SYS_UNPCB_H_
37
38 typedef uint64_t unp_gen_t;
39
40 #if defined(_KERNEL) || defined(_WANT_UNPCB)
41 #include <sys/queue.h>
42 #include <sys/ucred.h>
43
44 /*
45 * Protocol control block for an active
46 * instance of a UNIX internal protocol.
47 *
48 * A socket may be associated with a vnode in the
49 * filesystem. If so, the unp_vnode pointer holds
50 * a reference count to this vnode, which should be irele'd
51 * when the socket goes away.
52 *
53 * A socket may be connected to another socket, in which
54 * case the control block of the socket to which it is connected
55 * is given by unp_conn.
56 *
57 * A socket may be referenced by a number of sockets (e.g. several
58 * sockets may be connected to a datagram socket.) These sockets
59 * are in a linked list starting with unp_refs, linked through
60 * unp_nextref and null-terminated. Note that a socket may be referenced
61 * by a number of other sockets and may also reference a socket (not
62 * necessarily one which is referencing it). This generates
63 * the need for unp_refs and unp_nextref to be separate fields.
64 *
65 * Stream sockets keep copies of receive sockbuf sb_cc and sb_mbcnt
66 * so that changes in the sockbuf may be computed to modify
67 * back pressure on the sender accordingly.
68 */
69 LIST_HEAD(unp_head, unpcb);
70
71 struct unpcb {
72 /* Cache line 1 */
73 struct mtx unp_mtx; /* mutex */
74 struct unpcb *unp_conn; /* control block of connected socket */
75 volatile u_int unp_refcount;
76 short unp_flags; /* flags */
77 short unp_gcflag; /* Garbage collector flags. */
78 struct sockaddr_un *unp_addr; /* bound address of socket */
79 struct socket *unp_socket; /* pointer back to socket */
80 /* Cache line 2 */
81 struct vnode *unp_vnode; /* if associated with file */
82 struct xucred unp_peercred; /* peer credentials, if applicable */
83 LIST_ENTRY(unpcb) unp_reflink; /* link in unp_refs list */
84 LIST_ENTRY(unpcb) unp_link; /* glue on list of all PCBs */
85 struct unp_head unp_refs; /* referencing socket linked list */
86 unp_gen_t unp_gencnt; /* generation count of this instance */
87 struct file *unp_file; /* back-pointer to file for gc. */
88 u_int unp_msgcount; /* references from message queue */
89 ino_t unp_ino; /* fake inode number */
90 } __aligned(CACHE_LINE_SIZE);
91
92 /*
93 * Flags in unp_flags.
94 *
95 * UNP_HAVEPC - indicates that the unp_peercred member is filled in
96 * and is really the credentials of the connected peer. This is used
97 * to determine whether the contents should be sent to the user or
98 * not.
99 */
100 #define UNP_HAVEPC 0x001
101 #define UNP_WANTCRED 0x004 /* credentials wanted */
102 #define UNP_CONNWAIT 0x008 /* connect blocks until accepted */
103
104 /*
105 * These flags are used to handle non-atomicity in connect() and bind()
106 * operations on a socket: in particular, to avoid races between multiple
107 * threads or processes operating simultaneously on the same socket.
108 */
109 #define UNP_CONNECTING 0x010 /* Currently connecting. */
110 #define UNP_BINDING 0x020 /* Currently binding. */
111 #define UNP_NASCENT 0x040 /* Newborn child socket. */
112
113 /*
114 * Flags in unp_gcflag.
115 */
116 #define UNPGC_REF 0x1 /* unpcb has external ref. */
117 #define UNPGC_DEAD 0x2 /* unpcb might be dead. */
118 #define UNPGC_SCANNED 0x4 /* Has been scanned. */
119 #define UNPGC_IGNORE_RIGHTS 0x8 /* Attached rights are freed */
120
121 #define sotounpcb(so) ((struct unpcb *)((so)->so_pcb))
122
123 #endif /* _KERNEL || _WANT_UNPCB */
124
125 /*
126 * UNPCB structure exported to user-land via sysctl(3).
127 *
128 * Fields prefixed with "xu_" are unique to the export structure, and fields
129 * with "unp_" or other prefixes match corresponding fields of 'struct unpcb'.
130 *
131 * Legend:
132 * (s) - used by userland utilities in src
133 * (p) - used by utilities in ports
134 * (3) - is known to be used by third party software not in ports
135 * (n) - no known usage
136 *
137 * Evil hack: declare only if sys/socketvar.h have been included.
138 */
139 #ifdef _SYS_SOCKETVAR_H_
140 struct xunpcb {
141 ksize_t xu_len; /* length of this structure */
142 kvaddr_t xu_unpp; /* to help netstat, fstat */
143 kvaddr_t unp_vnode; /* (s) */
144 kvaddr_t unp_conn; /* (s) */
145 kvaddr_t xu_firstref; /* (s) */
146 kvaddr_t xu_nextref; /* (s) */
147 unp_gen_t unp_gencnt; /* (s) */
148 int64_t xu_spare64[8];
149 int32_t xu_spare32[8];
150 union {
151 struct sockaddr_un xu_addr; /* our bound address */
152 char xu_dummy1[256];
153 };
154 union {
155 struct sockaddr_un xu_caddr; /* their bound address */
156 char xu_dummy2[256];
157 };
158 struct xsocket xu_socket;
159 } __aligned(8);
160
161 struct xunpgen {
162 ksize_t xug_len;
163 u_int xug_count;
164 unp_gen_t xug_gen;
165 so_gen_t xug_sogen;
166 } __aligned(8);;
167 #endif /* _SYS_SOCKETVAR_H_ */
168
169 #if defined(_KERNEL)
170 struct thread;
171
172 /* In uipc_userreq.c */
173 void
174 unp_copy_peercred(struct thread *td, struct unpcb *client_unp,
175 struct unpcb *server_unp, struct unpcb *listen_unp);
176 #endif
177
178 #endif /* _SYS_UNPCB_H_ */
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