1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1994 Herb Peyerl <hpeyerl@novatel.ca> 5 * Copyright (c) 2006 nCircle Network Security, Inc. 6 * All rights reserved. 7 * 8 * This software was developed by Robert N. M. Watson for the TrustedBSD 9 * Project under contract to nCircle Network Security, Inc. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by Herb Peyerl. 22 * 4. The name of Herb Peyerl may not be used to endorse or promote products 23 * derived from this software without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 28 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 29 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 30 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 34 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 35 * 36 * $NetBSD: sysv_ipc.c,v 1.9 1995/06/02 19:04:22 mycroft Exp $ 37 */ 38 39 #include <sys/cdefs.h> 40 #include "opt_sysvipc.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/sem.h> 45 #include <sys/shm.h> 46 #include <sys/ipc.h> 47 #include <sys/priv.h> 48 #include <sys/proc.h> 49 #include <sys/ucred.h> 50 51 #ifndef SYSVSHM 52 void (*shmfork_hook)(struct proc *, struct proc *) = NULL; 53 void (*shmexit_hook)(struct vmspace *) = NULL; 54 55 /* called from kern_fork.c */ 56 void 57 shmfork(struct proc *p1, struct proc *p2) 58 { 59 if (shmfork_hook != NULL) 60 shmfork_hook(p1, p2); 61 } 62 63 /* called from kern_exit.c */ 64 void 65 shmexit(struct vmspace *vm) 66 { 67 if (shmexit_hook != NULL) 68 shmexit_hook(vm); 69 } 70 #endif 71 72 /* 73 * Check for IPC permission. 74 * 75 * Note: The MAC Framework does not require any modifications to the 76 * ipcperm() function, as access control checks are performed throughout the 77 * implementation of each primitive. Those entry point calls complement the 78 * ipcperm() discertionary checks. Unlike file system discretionary access 79 * control, the original create of an object is given the same rights as the 80 * current owner. 81 */ 82 int 83 ipcperm(struct thread *td, struct ipc_perm *perm, int acc_mode) 84 { 85 struct ucred *cred = td->td_ucred; 86 int error, obj_mode, dac_granted, priv_granted; 87 88 dac_granted = 0; 89 if (cred->cr_uid == perm->cuid || cred->cr_uid == perm->uid) { 90 obj_mode = perm->mode; 91 dac_granted |= IPC_M; 92 } else if (groupmember(perm->gid, cred) || 93 groupmember(perm->cgid, cred)) { 94 obj_mode = perm->mode; 95 obj_mode <<= 3; 96 } else { 97 obj_mode = perm->mode; 98 obj_mode <<= 6; 99 } 100 101 /* 102 * While the System V IPC permission model allows IPC_M to be 103 * granted, as part of the mode, our implementation requires 104 * privilege to adminster the object if not the owner or creator. 105 */ 106 #if 0 107 if (obj_mode & IPC_M) 108 dac_granted |= IPC_M; 109 #endif 110 if (obj_mode & IPC_R) 111 dac_granted |= IPC_R; 112 if (obj_mode & IPC_W) 113 dac_granted |= IPC_W; 114 115 /* 116 * Simple case: all required rights are granted by DAC. 117 */ 118 if ((dac_granted & acc_mode) == acc_mode) 119 return (0); 120 121 /* 122 * Privilege is required to satisfy the request. 123 */ 124 priv_granted = 0; 125 if ((acc_mode & IPC_M) && !(dac_granted & IPC_M)) { 126 error = priv_check(td, PRIV_IPC_ADMIN); 127 if (error == 0) 128 priv_granted |= IPC_M; 129 } 130 131 if ((acc_mode & IPC_R) && !(dac_granted & IPC_R)) { 132 error = priv_check(td, PRIV_IPC_READ); 133 if (error == 0) 134 priv_granted |= IPC_R; 135 } 136 137 if ((acc_mode & IPC_W) && !(dac_granted & IPC_W)) { 138 error = priv_check(td, PRIV_IPC_WRITE); 139 if (error == 0) 140 priv_granted |= IPC_W; 141 } 142 143 if (((dac_granted | priv_granted) & acc_mode) == acc_mode) 144 return (0); 145 else 146 return (EACCES); 147 } 148 149 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 150 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 151 void 152 ipcperm_old2new(struct ipc_perm_old *old, struct ipc_perm *new) 153 { 154 155 new->cuid = old->cuid; 156 new->cgid = old->cgid; 157 new->uid = old->uid; 158 new->gid = old->gid; 159 new->mode = old->mode; 160 new->seq = old->seq; 161 new->key = old->key; 162 } 163 164 void 165 ipcperm_new2old(struct ipc_perm *new, struct ipc_perm_old *old) 166 { 167 168 /* XXX: How to handle ID's > USHORT_MAX? */ 169 old->cuid = new->cuid; 170 old->cgid = new->cgid; 171 old->uid = new->uid; 172 old->gid = new->gid; 173 old->mode = new->mode; 174 old->seq = new->seq; 175 old->key = new->key; 176 } 177 #endif 178 179 #ifdef COMPAT_FREEBSD32 180 #include <sys/mount.h> 181 #include <sys/socket.h> 182 #include <compat/freebsd32/freebsd32.h> 183 #include <compat/freebsd32/freebsd32_ipc.h> 184 #include <compat/freebsd32/freebsd32_proto.h> 185 #include <compat/freebsd32/freebsd32_signal.h> 186 #include <compat/freebsd32/freebsd32_syscall.h> 187 #include <compat/freebsd32/freebsd32_util.h> 188 189 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 190 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 191 void 192 freebsd32_ipcperm_old_in(struct ipc_perm_old32 *ip32, struct ipc_perm *ip) 193 { 194 195 CP(*ip32, *ip, cuid); 196 CP(*ip32, *ip, cgid); 197 CP(*ip32, *ip, uid); 198 CP(*ip32, *ip, gid); 199 CP(*ip32, *ip, mode); 200 CP(*ip32, *ip, seq); 201 CP(*ip32, *ip, key); 202 } 203 204 void 205 freebsd32_ipcperm_old_out(struct ipc_perm *ip, struct ipc_perm_old32 *ip32) 206 { 207 208 CP(*ip, *ip32, cuid); 209 CP(*ip, *ip32, cgid); 210 CP(*ip, *ip32, uid); 211 CP(*ip, *ip32, gid); 212 CP(*ip, *ip32, mode); 213 CP(*ip, *ip32, seq); 214 CP(*ip, *ip32, key); 215 } 216 #endif 217 218 void 219 freebsd32_ipcperm_in(struct ipc_perm32 *ip32, struct ipc_perm *ip) 220 { 221 222 CP(*ip32, *ip, cuid); 223 CP(*ip32, *ip, cgid); 224 CP(*ip32, *ip, uid); 225 CP(*ip32, *ip, gid); 226 CP(*ip32, *ip, mode); 227 CP(*ip32, *ip, seq); 228 CP(*ip32, *ip, key); 229 } 230 231 void 232 freebsd32_ipcperm_out(struct ipc_perm *ip, struct ipc_perm32 *ip32) 233 { 234 235 CP(*ip, *ip32, cuid); 236 CP(*ip, *ip32, cgid); 237 CP(*ip, *ip32, uid); 238 CP(*ip, *ip32, gid); 239 CP(*ip, *ip32, mode); 240 CP(*ip, *ip32, seq); 241 CP(*ip, *ip32, key); 242 } 243 #endif 244