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 32 #ifndef _SYS_UNPCB_H_ 33 #define _SYS_UNPCB_H_ 34 35 typedef uint64_t unp_gen_t; 36 37 #if defined(_KERNEL) || defined(_WANT_UNPCB) 38 #include <sys/queue.h> 39 #include <sys/ucred.h> 40 41 /* 42 * Protocol control block for an active 43 * instance of a UNIX internal protocol. 44 * 45 * A socket may be associated with a vnode in the 46 * filesystem. If so, the unp_vnode pointer holds 47 * a reference count to this vnode, which should be irele'd 48 * when the socket goes away. 49 * 50 * A socket may be connected to another socket, in which 51 * case the control block of the socket to which it is connected 52 * is given by unp_conn. 53 * 54 * A socket may be referenced by a number of sockets (e.g. several 55 * sockets may be connected to a datagram socket.) These sockets 56 * are in a linked list starting with unp_refs, linked through 57 * unp_nextref and null-terminated. Note that a socket may be referenced 58 * by a number of other sockets and may also reference a socket (not 59 * necessarily one which is referencing it). This generates 60 * the need for unp_refs and unp_nextref to be separate fields. 61 * 62 * Stream sockets keep copies of receive sockbuf sb_cc and sb_mbcnt 63 * so that changes in the sockbuf may be computed to modify 64 * back pressure on the sender accordingly. 65 * 66 * Locking key: 67 * (a) Atomic 68 * (c) Constant 69 * (g) Locked using linkage lock 70 * (l) Locked using list lock 71 * (p) Locked using pcb lock 72 */ 73 LIST_HEAD(unp_head, unpcb); 74 75 struct unpcb { 76 /* Cache line 1 */ 77 struct mtx unp_mtx; /* PCB mutex */ 78 struct unpcb *unp_conn; /* (p) connected socket */ 79 volatile u_int unp_refcount; /* (a, p) atomic refcount */ 80 short unp_flags; /* (p) PCB flags */ 81 short unp_gcflag; /* (g) Garbage collector flags */ 82 struct sockaddr_un *unp_addr; /* (p) bound address of socket */ 83 struct socket *unp_socket; /* (c) pointer back to socket */ 84 /* Cache line 2 */ 85 u_int unp_pairbusy; /* (p) threads acquiring peer locks */ 86 struct vnode *unp_vnode; /* (p) associated file if applicable */ 87 struct xucred unp_peercred; /* (p) peer credentials if applicable */ 88 LIST_ENTRY(unpcb) unp_reflink; /* (l) link in unp_refs list */ 89 LIST_ENTRY(unpcb) unp_link; /* (g) glue on list of all PCBs */ 90 struct unp_head unp_refs; /* (l) referencing socket linked list */ 91 unp_gen_t unp_gencnt; /* (g) generation count of this item */ 92 struct file *unp_file; /* (g) back-pointer to file for gc */ 93 u_int unp_msgcount; /* (g) references from message queue */ 94 u_int unp_gcrefs; /* (g) garbage collector refcount */ 95 ino_t unp_ino; /* (g) fake inode number */ 96 LIST_ENTRY(unpcb) unp_dead; /* (g) link in dead list */ 97 } __aligned(CACHE_LINE_SIZE); 98 99 /* 100 * Flags in unp_flags. 101 * 102 * UNP_HAVEPC - indicates that the unp_peercred member is filled in 103 * and is really the credentials of the connected peer. This is used 104 * to determine whether the contents should be sent to the user or 105 * not. 106 */ 107 #define UNP_HAVEPC 0x001 108 #define UNP_WANTCRED_ALWAYS 0x002 /* credentials wanted always */ 109 #define UNP_WANTCRED_ONESHOT 0x004 /* credentials wanted once */ 110 #define UNP_WANTCRED_MASK (UNP_WANTCRED_ONESHOT | UNP_WANTCRED_ALWAYS) 111 112 /* 113 * These flags are used to handle non-atomicity in connect() and bind() 114 * operations on a socket: in particular, to avoid races between multiple 115 * threads or processes operating simultaneously on the same socket. 116 */ 117 #define UNP_CONNECTING 0x010 /* Currently connecting. */ 118 #define UNP_BINDING 0x020 /* Currently binding. */ 119 #define UNP_WAITING 0x040 /* Peer state is changing. */ 120 121 /* 122 * Flags in unp_gcflag. 123 */ 124 #define UNPGC_DEAD 0x1 /* unpcb might be dead. */ 125 #define UNPGC_IGNORE_RIGHTS 0x2 /* Attached rights are freed */ 126 127 #define sotounpcb(so) ((struct unpcb *)((so)->so_pcb)) 128 129 #endif /* _KERNEL || _WANT_UNPCB */ 130 131 /* 132 * UNPCB structure exported to user-land via sysctl(3). 133 * 134 * Fields prefixed with "xu_" are unique to the export structure, and fields 135 * with "unp_" or other prefixes match corresponding fields of 'struct unpcb'. 136 * 137 * Legend: 138 * (s) - used by userland utilities in src 139 * (p) - used by utilities in ports 140 * (3) - is known to be used by third party software not in ports 141 * (n) - no known usage 142 * 143 * Evil hack: declare only if sys/socketvar.h have been included. 144 */ 145 #ifdef _SYS_SOCKETVAR_H_ 146 struct xunpcb { 147 ksize_t xu_len; /* length of this structure */ 148 kvaddr_t xu_unpp; /* to help netstat, fstat */ 149 kvaddr_t unp_vnode; /* (s) */ 150 kvaddr_t unp_conn; /* (s) */ 151 kvaddr_t xu_firstref; /* (s) */ 152 kvaddr_t xu_nextref; /* (s) */ 153 unp_gen_t unp_gencnt; /* (s) */ 154 int64_t xu_spare64[8]; 155 int32_t xu_spare32[8]; 156 union { 157 struct sockaddr_un xu_addr; /* our bound address */ 158 char xu_dummy1[256]; 159 }; 160 union { 161 struct sockaddr_un xu_caddr; /* their bound address */ 162 char xu_dummy2[256]; 163 }; 164 struct xsocket xu_socket; 165 } __aligned(MAX(8, sizeof(void *))); 166 167 struct xunpgen { 168 ksize_t xug_len; 169 u_int xug_count; 170 unp_gen_t xug_gen; 171 so_gen_t xug_sogen; 172 } __aligned(8); 173 #endif /* _SYS_SOCKETVAR_H_ */ 174 175 #if defined(_KERNEL) 176 struct thread; 177 178 /* In uipc_userreq.c */ 179 void 180 unp_copy_peercred(struct thread *td, struct unpcb *client_unp, 181 struct unpcb *server_unp, struct unpcb *listen_unp); 182 #endif 183 184 #endif /* _SYS_UNPCB_H_ */ 185