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 __FBSDID("$FreeBSD$"); 41 42 #include "opt_compat.h" 43 #include "opt_sysvipc.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/sem.h> 48 #include <sys/shm.h> 49 #include <sys/ipc.h> 50 #include <sys/priv.h> 51 #include <sys/proc.h> 52 #include <sys/ucred.h> 53 54 void (*shmfork_hook)(struct proc *, struct proc *) = NULL; 55 void (*shmexit_hook)(struct vmspace *) = NULL; 56 57 /* called from kern_fork.c */ 58 void 59 shmfork(p1, p2) 60 struct proc *p1, *p2; 61 { 62 63 if (shmfork_hook != NULL) 64 shmfork_hook(p1, p2); 65 return; 66 } 67 68 /* called from kern_exit.c */ 69 void 70 shmexit(struct vmspace *vm) 71 { 72 73 if (shmexit_hook != NULL) 74 shmexit_hook(vm); 75 return; 76 } 77 78 /* 79 * Check for IPC permission. 80 * 81 * Note: The MAC Framework does not require any modifications to the 82 * ipcperm() function, as access control checks are performed throughout the 83 * implementation of each primitive. Those entry point calls complement the 84 * ipcperm() discertionary checks. Unlike file system discretionary access 85 * control, the original create of an object is given the same rights as the 86 * current owner. 87 */ 88 int 89 ipcperm(struct thread *td, struct ipc_perm *perm, int acc_mode) 90 { 91 struct ucred *cred = td->td_ucred; 92 int error, obj_mode, dac_granted, priv_granted; 93 94 dac_granted = 0; 95 if (cred->cr_uid == perm->cuid || cred->cr_uid == perm->uid) { 96 obj_mode = perm->mode; 97 dac_granted |= IPC_M; 98 } else if (groupmember(perm->gid, cred) || 99 groupmember(perm->cgid, cred)) { 100 obj_mode = perm->mode; 101 obj_mode <<= 3; 102 } else { 103 obj_mode = perm->mode; 104 obj_mode <<= 6; 105 } 106 107 /* 108 * While the System V IPC permission model allows IPC_M to be 109 * granted, as part of the mode, our implementation requires 110 * privilege to adminster the object if not the owner or creator. 111 */ 112 #if 0 113 if (obj_mode & IPC_M) 114 dac_granted |= IPC_M; 115 #endif 116 if (obj_mode & IPC_R) 117 dac_granted |= IPC_R; 118 if (obj_mode & IPC_W) 119 dac_granted |= IPC_W; 120 121 /* 122 * Simple case: all required rights are granted by DAC. 123 */ 124 if ((dac_granted & acc_mode) == acc_mode) 125 return (0); 126 127 /* 128 * Privilege is required to satisfy the request. 129 */ 130 priv_granted = 0; 131 if ((acc_mode & IPC_M) && !(dac_granted & IPC_M)) { 132 error = priv_check(td, PRIV_IPC_ADMIN); 133 if (error == 0) 134 priv_granted |= IPC_M; 135 } 136 137 if ((acc_mode & IPC_R) && !(dac_granted & IPC_R)) { 138 error = priv_check(td, PRIV_IPC_READ); 139 if (error == 0) 140 priv_granted |= IPC_R; 141 } 142 143 if ((acc_mode & IPC_W) && !(dac_granted & IPC_W)) { 144 error = priv_check(td, PRIV_IPC_WRITE); 145 if (error == 0) 146 priv_granted |= IPC_W; 147 } 148 149 if (((dac_granted | priv_granted) & acc_mode) == acc_mode) 150 return (0); 151 else 152 return (EACCES); 153 } 154 155 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 156 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 157 void 158 ipcperm_old2new(struct ipc_perm_old *old, struct ipc_perm *new) 159 { 160 161 new->cuid = old->cuid; 162 new->cgid = old->cgid; 163 new->uid = old->uid; 164 new->gid = old->gid; 165 new->mode = old->mode; 166 new->seq = old->seq; 167 new->key = old->key; 168 } 169 170 void 171 ipcperm_new2old(struct ipc_perm *new, struct ipc_perm_old *old) 172 { 173 174 /* XXX: How to handle ID's > USHORT_MAX? */ 175 old->cuid = new->cuid; 176 old->cgid = new->cgid; 177 old->uid = new->uid; 178 old->gid = new->gid; 179 old->mode = new->mode; 180 old->seq = new->seq; 181 old->key = new->key; 182 } 183 #endif 184 185 #ifdef COMPAT_FREEBSD32 186 #include <sys/mount.h> 187 #include <sys/socket.h> 188 #include <compat/freebsd32/freebsd32.h> 189 #include <compat/freebsd32/freebsd32_ipc.h> 190 #include <compat/freebsd32/freebsd32_proto.h> 191 #include <compat/freebsd32/freebsd32_signal.h> 192 #include <compat/freebsd32/freebsd32_syscall.h> 193 #include <compat/freebsd32/freebsd32_util.h> 194 195 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 196 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 197 void 198 freebsd32_ipcperm_old_in(struct ipc_perm32_old *ip32, struct ipc_perm *ip) 199 { 200 201 CP(*ip32, *ip, cuid); 202 CP(*ip32, *ip, cgid); 203 CP(*ip32, *ip, uid); 204 CP(*ip32, *ip, gid); 205 CP(*ip32, *ip, mode); 206 CP(*ip32, *ip, seq); 207 CP(*ip32, *ip, key); 208 } 209 210 void 211 freebsd32_ipcperm_old_out(struct ipc_perm *ip, struct ipc_perm32_old *ip32) 212 { 213 214 CP(*ip, *ip32, cuid); 215 CP(*ip, *ip32, cgid); 216 CP(*ip, *ip32, uid); 217 CP(*ip, *ip32, gid); 218 CP(*ip, *ip32, mode); 219 CP(*ip, *ip32, seq); 220 CP(*ip, *ip32, key); 221 } 222 #endif 223 224 void 225 freebsd32_ipcperm_in(struct ipc_perm32 *ip32, struct ipc_perm *ip) 226 { 227 228 CP(*ip32, *ip, cuid); 229 CP(*ip32, *ip, cgid); 230 CP(*ip32, *ip, uid); 231 CP(*ip32, *ip, gid); 232 CP(*ip32, *ip, mode); 233 CP(*ip32, *ip, seq); 234 CP(*ip32, *ip, key); 235 } 236 237 void 238 freebsd32_ipcperm_out(struct ipc_perm *ip, struct ipc_perm32 *ip32) 239 { 240 241 CP(*ip, *ip32, cuid); 242 CP(*ip, *ip32, cgid); 243 CP(*ip, *ip32, uid); 244 CP(*ip, *ip32, gid); 245 CP(*ip, *ip32, mode); 246 CP(*ip, *ip32, seq); 247 CP(*ip, *ip32, key); 248 } 249 #endif 250