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 */ 33 34 #ifndef _SYS_UNPCB_H_ 35 #define _SYS_UNPCB_H_ 36 37 typedef uint64_t unp_gen_t; 38 39 #if defined(_KERNEL) || defined(_WANT_UNPCB) 40 #include <sys/queue.h> 41 #include <sys/ucred.h> 42 43 /* 44 * Protocol control block for an active 45 * instance of a UNIX internal protocol. 46 * 47 * A socket may be associated with a vnode in the 48 * filesystem. If so, the unp_vnode pointer holds 49 * a reference count to this vnode, which should be irele'd 50 * when the socket goes away. 51 * 52 * A socket may be connected to another socket, in which 53 * case the control block of the socket to which it is connected 54 * is given by unp_conn. 55 * 56 * A socket may be referenced by a number of sockets (e.g. several 57 * sockets may be connected to a datagram socket.) These sockets 58 * are in a linked list starting with unp_refs, linked through 59 * unp_nextref and null-terminated. Note that a socket may be referenced 60 * by a number of other sockets and may also reference a socket (not 61 * necessarily one which is referencing it). This generates 62 * the need for unp_refs and unp_nextref to be separate fields. 63 * 64 * Stream sockets keep copies of receive sockbuf sb_cc and sb_mbcnt 65 * so that changes in the sockbuf may be computed to modify 66 * back pressure on the sender accordingly. 67 * 68 * Locking key: 69 * (a) Atomic 70 * (c) Constant 71 * (g) Locked using linkage lock 72 * (l) Locked using list lock 73 * (p) Locked using pcb lock 74 */ 75 LIST_HEAD(unp_head, unpcb); 76 77 struct unpcb { 78 /* Cache line 1 */ 79 struct mtx unp_mtx; /* PCB mutex */ 80 struct unpcb *unp_conn; /* (p) connected socket */ 81 volatile u_int unp_refcount; /* (a, p) atomic refcount */ 82 short unp_flags; /* (p) PCB flags */ 83 short unp_gcflag; /* (g) Garbage collector flags */ 84 struct sockaddr_un *unp_addr; /* (p) bound address of socket */ 85 struct socket *unp_socket; /* (c) pointer back to socket */ 86 /* Cache line 2 */ 87 u_int unp_pairbusy; /* (p) threads acquiring peer locks */ 88 struct vnode *unp_vnode; /* (p) associated file if applicable */ 89 struct xucred unp_peercred; /* (p) peer credentials if applicable */ 90 LIST_ENTRY(unpcb) unp_reflink; /* (l) link in unp_refs list */ 91 LIST_ENTRY(unpcb) unp_link; /* (g) glue on list of all PCBs */ 92 struct unp_head unp_refs; /* (l) referencing socket linked list */ 93 unp_gen_t unp_gencnt; /* (g) generation count of this item */ 94 struct file *unp_file; /* (g) back-pointer to file for gc */ 95 u_int unp_msgcount; /* (g) references from message queue */ 96 u_int unp_gcrefs; /* (g) garbage collector refcount */ 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_ALWAYS 0x002 /* credentials wanted always */ 111 #define UNP_WANTCRED_ONESHOT 0x004 /* credentials wanted once */ 112 #define UNP_CONNWAIT 0x008 /* connect blocks until accepted */ 113 114 #define UNP_WANTCRED_MASK (UNP_WANTCRED_ONESHOT | UNP_WANTCRED_ALWAYS) 115 116 /* 117 * These flags are used to handle non-atomicity in connect() and bind() 118 * operations on a socket: in particular, to avoid races between multiple 119 * threads or processes operating simultaneously on the same socket. 120 */ 121 #define UNP_CONNECTING 0x010 /* Currently connecting. */ 122 #define UNP_BINDING 0x020 /* Currently binding. */ 123 #define UNP_WAITING 0x040 /* Peer state is changing. */ 124 125 /* 126 * Flags in unp_gcflag. 127 */ 128 #define UNPGC_DEAD 0x1 /* unpcb might be dead. */ 129 #define UNPGC_IGNORE_RIGHTS 0x2 /* Attached rights are freed */ 130 131 #define sotounpcb(so) ((struct unpcb *)((so)->so_pcb)) 132 133 #endif /* _KERNEL || _WANT_UNPCB */ 134 135 /* 136 * UNPCB structure exported to user-land via sysctl(3). 137 * 138 * Fields prefixed with "xu_" are unique to the export structure, and fields 139 * with "unp_" or other prefixes match corresponding fields of 'struct unpcb'. 140 * 141 * Legend: 142 * (s) - used by userland utilities in src 143 * (p) - used by utilities in ports 144 * (3) - is known to be used by third party software not in ports 145 * (n) - no known usage 146 * 147 * Evil hack: declare only if sys/socketvar.h have been included. 148 */ 149 #ifdef _SYS_SOCKETVAR_H_ 150 struct xunpcb { 151 ksize_t xu_len; /* length of this structure */ 152 kvaddr_t xu_unpp; /* to help netstat, fstat */ 153 kvaddr_t unp_vnode; /* (s) */ 154 kvaddr_t unp_conn; /* (s) */ 155 kvaddr_t xu_firstref; /* (s) */ 156 kvaddr_t xu_nextref; /* (s) */ 157 unp_gen_t unp_gencnt; /* (s) */ 158 int64_t xu_spare64[8]; 159 int32_t xu_spare32[8]; 160 union { 161 struct sockaddr_un xu_addr; /* our bound address */ 162 char xu_dummy1[256]; 163 }; 164 union { 165 struct sockaddr_un xu_caddr; /* their bound address */ 166 char xu_dummy2[256]; 167 }; 168 struct xsocket xu_socket; 169 } __aligned(MAX(8, sizeof(void *))); 170 171 struct xunpgen { 172 ksize_t xug_len; 173 u_int xug_count; 174 unp_gen_t xug_gen; 175 so_gen_t xug_sogen; 176 } __aligned(8); 177 #endif /* _SYS_SOCKETVAR_H_ */ 178 179 #if defined(_KERNEL) 180 struct thread; 181 182 /* In uipc_userreq.c */ 183 void 184 unp_copy_peercred(struct thread *td, struct unpcb *client_unp, 185 struct unpcb *server_unp, struct unpcb *listen_unp); 186 #endif 187 188 #endif /* _SYS_UNPCB_H_ */ 189