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_sysvipc.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/sem.h> 47 #include <sys/shm.h> 48 #include <sys/ipc.h> 49 #include <sys/priv.h> 50 #include <sys/proc.h> 51 #include <sys/ucred.h> 52 53 #ifndef SYSVSHM 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(struct proc *p1, struct proc *p2) 60 { 61 if (shmfork_hook != NULL) 62 shmfork_hook(p1, p2); 63 } 64 65 /* called from kern_exit.c */ 66 void 67 shmexit(struct vmspace *vm) 68 { 69 if (shmexit_hook != NULL) 70 shmexit_hook(vm); 71 } 72 #endif 73 74 /* 75 * Check for IPC permission. 76 * 77 * Note: The MAC Framework does not require any modifications to the 78 * ipcperm() function, as access control checks are performed throughout the 79 * implementation of each primitive. Those entry point calls complement the 80 * ipcperm() discertionary checks. Unlike file system discretionary access 81 * control, the original create of an object is given the same rights as the 82 * current owner. 83 */ 84 int 85 ipcperm(struct thread *td, struct ipc_perm *perm, int acc_mode) 86 { 87 struct ucred *cred = td->td_ucred; 88 int error, obj_mode, dac_granted, priv_granted; 89 90 dac_granted = 0; 91 if (cred->cr_uid == perm->cuid || cred->cr_uid == perm->uid) { 92 obj_mode = perm->mode; 93 dac_granted |= IPC_M; 94 } else if (groupmember(perm->gid, cred) || 95 groupmember(perm->cgid, cred)) { 96 obj_mode = perm->mode; 97 obj_mode <<= 3; 98 } else { 99 obj_mode = perm->mode; 100 obj_mode <<= 6; 101 } 102 103 /* 104 * While the System V IPC permission model allows IPC_M to be 105 * granted, as part of the mode, our implementation requires 106 * privilege to adminster the object if not the owner or creator. 107 */ 108 #if 0 109 if (obj_mode & IPC_M) 110 dac_granted |= IPC_M; 111 #endif 112 if (obj_mode & IPC_R) 113 dac_granted |= IPC_R; 114 if (obj_mode & IPC_W) 115 dac_granted |= IPC_W; 116 117 /* 118 * Simple case: all required rights are granted by DAC. 119 */ 120 if ((dac_granted & acc_mode) == acc_mode) 121 return (0); 122 123 /* 124 * Privilege is required to satisfy the request. 125 */ 126 priv_granted = 0; 127 if ((acc_mode & IPC_M) && !(dac_granted & IPC_M)) { 128 error = priv_check(td, PRIV_IPC_ADMIN); 129 if (error == 0) 130 priv_granted |= IPC_M; 131 } 132 133 if ((acc_mode & IPC_R) && !(dac_granted & IPC_R)) { 134 error = priv_check(td, PRIV_IPC_READ); 135 if (error == 0) 136 priv_granted |= IPC_R; 137 } 138 139 if ((acc_mode & IPC_W) && !(dac_granted & IPC_W)) { 140 error = priv_check(td, PRIV_IPC_WRITE); 141 if (error == 0) 142 priv_granted |= IPC_W; 143 } 144 145 if (((dac_granted | priv_granted) & acc_mode) == acc_mode) 146 return (0); 147 else 148 return (EACCES); 149 } 150 151 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 152 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 153 void 154 ipcperm_old2new(struct ipc_perm_old *old, struct ipc_perm *new) 155 { 156 157 new->cuid = old->cuid; 158 new->cgid = old->cgid; 159 new->uid = old->uid; 160 new->gid = old->gid; 161 new->mode = old->mode; 162 new->seq = old->seq; 163 new->key = old->key; 164 } 165 166 void 167 ipcperm_new2old(struct ipc_perm *new, struct ipc_perm_old *old) 168 { 169 170 /* XXX: How to handle ID's > USHORT_MAX? */ 171 old->cuid = new->cuid; 172 old->cgid = new->cgid; 173 old->uid = new->uid; 174 old->gid = new->gid; 175 old->mode = new->mode; 176 old->seq = new->seq; 177 old->key = new->key; 178 } 179 #endif 180 181 #ifdef COMPAT_FREEBSD32 182 #include <sys/mount.h> 183 #include <sys/socket.h> 184 #include <compat/freebsd32/freebsd32.h> 185 #include <compat/freebsd32/freebsd32_ipc.h> 186 #include <compat/freebsd32/freebsd32_proto.h> 187 #include <compat/freebsd32/freebsd32_signal.h> 188 #include <compat/freebsd32/freebsd32_syscall.h> 189 #include <compat/freebsd32/freebsd32_util.h> 190 191 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 192 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 193 void 194 freebsd32_ipcperm_old_in(struct ipc_perm_old32 *ip32, struct ipc_perm *ip) 195 { 196 197 CP(*ip32, *ip, cuid); 198 CP(*ip32, *ip, cgid); 199 CP(*ip32, *ip, uid); 200 CP(*ip32, *ip, gid); 201 CP(*ip32, *ip, mode); 202 CP(*ip32, *ip, seq); 203 CP(*ip32, *ip, key); 204 } 205 206 void 207 freebsd32_ipcperm_old_out(struct ipc_perm *ip, struct ipc_perm_old32 *ip32) 208 { 209 210 CP(*ip, *ip32, cuid); 211 CP(*ip, *ip32, cgid); 212 CP(*ip, *ip32, uid); 213 CP(*ip, *ip32, gid); 214 CP(*ip, *ip32, mode); 215 CP(*ip, *ip32, seq); 216 CP(*ip, *ip32, key); 217 } 218 #endif 219 220 void 221 freebsd32_ipcperm_in(struct ipc_perm32 *ip32, struct ipc_perm *ip) 222 { 223 224 CP(*ip32, *ip, cuid); 225 CP(*ip32, *ip, cgid); 226 CP(*ip32, *ip, uid); 227 CP(*ip32, *ip, gid); 228 CP(*ip32, *ip, mode); 229 CP(*ip32, *ip, seq); 230 CP(*ip32, *ip, key); 231 } 232 233 void 234 freebsd32_ipcperm_out(struct ipc_perm *ip, struct ipc_perm32 *ip32) 235 { 236 237 CP(*ip, *ip32, cuid); 238 CP(*ip, *ip32, cgid); 239 CP(*ip, *ip32, uid); 240 CP(*ip, *ip32, gid); 241 CP(*ip, *ip32, mode); 242 CP(*ip, *ip32, seq); 243 CP(*ip, *ip32, key); 244 } 245 #endif 246