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: stable/12/sys/sys/unpcb.h 366488 2020-10-06 14:03:59Z markj $ 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 * Locking key: 70 * (a) Atomic 71 * (c) Constant 72 * (g) Locked using linkage lock 73 * (l) Locked using list lock 74 * (p) Locked using pcb lock 75 */ 76 LIST_HEAD(unp_head, unpcb); 77 78 struct unpcb { 79 /* Cache line 1 */ 80 struct mtx unp_mtx; /* PCB mutex */ 81 struct unpcb *unp_conn; /* (p) connected socket */ 82 volatile u_int unp_refcount; /* (a, p) atomic refcount */ 83 short unp_flags; /* (p) PCB flags */ 84 short unp_gcflag; /* (g) Garbage collector flags */ 85 struct sockaddr_un *unp_addr; /* (p) bound address of socket */ 86 struct socket *unp_socket; /* (c) pointer back to socket */ 87 /* Cache line 2 */ 88 u_int unp_pairbusy; /* (p) threads acquiring peer locks */ 89 struct vnode *unp_vnode; /* (p) associated file if applicable */ 90 struct xucred unp_peercred; /* (p) peer credentials if applicable */ 91 LIST_ENTRY(unpcb) unp_reflink; /* (l) link in unp_refs list */ 92 LIST_ENTRY(unpcb) unp_link; /* (g) glue on list of all PCBs */ 93 struct unp_head unp_refs; /* (l) referencing socket linked list */ 94 unp_gen_t unp_gencnt; /* (g) generation count of this item */ 95 struct file *unp_file; /* (g) back-pointer to file for gc */ 96 u_int unp_msgcount; /* (g) references from message queue */ 97 ino_t unp_ino; /* (g) fake inode number */ 98 LIST_ENTRY(unpcb) unp_dead; /* (g) link in dead list */ 99 } __aligned(CACHE_LINE_SIZE); 100 101 /* 102 * Flags in unp_flags. 103 * 104 * UNP_HAVEPC - indicates that the unp_peercred member is filled in 105 * and is really the credentials of the connected peer. This is used 106 * to determine whether the contents should be sent to the user or 107 * not. 108 */ 109 #define UNP_HAVEPC 0x001 110 #define UNP_WANTCRED 0x004 /* credentials wanted */ 111 #define UNP_CONNWAIT 0x008 /* connect blocks until accepted */ 112 113 /* 114 * These flags are used to handle non-atomicity in connect() and bind() 115 * operations on a socket: in particular, to avoid races between multiple 116 * threads or processes operating simultaneously on the same socket. 117 */ 118 #define UNP_CONNECTING 0x010 /* Currently connecting. */ 119 #define UNP_BINDING 0x020 /* Currently binding. */ 120 #define UNP_WAITING 0x040 /* Peer state is changing. */ 121 122 /* 123 * Flags in unp_gcflag. 124 */ 125 #define UNPGC_REF 0x1 /* unpcb has external ref. */ 126 #define UNPGC_DEAD 0x2 /* unpcb might be dead. */ 127 #define UNPGC_SCANNED 0x4 /* Has been scanned. */ 128 #define UNPGC_IGNORE_RIGHTS 0x8 /* Attached rights are freed */ 129 130 #define sotounpcb(so) ((struct unpcb *)((so)->so_pcb)) 131 132 #endif /* _KERNEL || _WANT_UNPCB */ 133 134 /* 135 * UNPCB structure exported to user-land via sysctl(3). 136 * 137 * Fields prefixed with "xu_" are unique to the export structure, and fields 138 * with "unp_" or other prefixes match corresponding fields of 'struct unpcb'. 139 * 140 * Legend: 141 * (s) - used by userland utilities in src 142 * (p) - used by utilities in ports 143 * (3) - is known to be used by third party software not in ports 144 * (n) - no known usage 145 * 146 * Evil hack: declare only if sys/socketvar.h have been included. 147 */ 148 #ifdef _SYS_SOCKETVAR_H_ 149 struct xunpcb { 150 ksize_t xu_len; /* length of this structure */ 151 kvaddr_t xu_unpp; /* to help netstat, fstat */ 152 kvaddr_t unp_vnode; /* (s) */ 153 kvaddr_t unp_conn; /* (s) */ 154 kvaddr_t xu_firstref; /* (s) */ 155 kvaddr_t xu_nextref; /* (s) */ 156 unp_gen_t unp_gencnt; /* (s) */ 157 int64_t xu_spare64[8]; 158 int32_t xu_spare32[8]; 159 union { 160 struct sockaddr_un xu_addr; /* our bound address */ 161 char xu_dummy1[256]; 162 }; 163 union { 164 struct sockaddr_un xu_caddr; /* their bound address */ 165 char xu_dummy2[256]; 166 }; 167 struct xsocket xu_socket; 168 } __aligned(MAX(8, sizeof(void *))); 169 170 struct xunpgen { 171 ksize_t xug_len; 172 u_int xug_count; 173 unp_gen_t xug_gen; 174 so_gen_t xug_sogen; 175 } __aligned(8);; 176 #endif /* _SYS_SOCKETVAR_H_ */ 177 178 #if defined(_KERNEL) 179 struct thread; 180 181 /* In uipc_userreq.c */ 182 void 183 unp_copy_peercred(struct thread *td, struct unpcb *client_unp, 184 struct unpcb *server_unp, struct unpcb *listen_unp); 185 #endif 186 187 #endif /* _SYS_UNPCB_H_ */ 188