sysv_ipc.c revision 1.24.2.1
1 /* $NetBSD: sysv_ipc.c,v 1.24.2.1 2014/08/20 00:04:29 tls Exp $ */ 2 3 /*- 4 * Copyright (c) 1998, 2007 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Charles M. Hannum. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: sysv_ipc.c,v 1.24.2.1 2014/08/20 00:04:29 tls Exp $"); 34 35 #include "opt_sysv.h" 36 #include "opt_compat_netbsd.h" 37 #include <sys/param.h> 38 #include <sys/kernel.h> 39 #include <sys/proc.h> 40 #include <sys/ipc.h> 41 #ifdef SYSVMSG 42 #include <sys/msg.h> 43 #endif 44 #ifdef SYSVSEM 45 #include <sys/sem.h> 46 #endif 47 #ifdef SYSVSHM 48 #include <sys/shm.h> 49 #endif 50 #include <sys/systm.h> 51 #include <sys/kmem.h> 52 #include <sys/mount.h> 53 #include <sys/vnode.h> 54 #include <sys/stat.h> 55 #include <sys/sysctl.h> 56 #include <sys/kauth.h> 57 58 #ifdef COMPAT_50 59 #include <compat/sys/ipc.h> 60 #endif 61 62 static kauth_listener_t sysvipc_listener = NULL; 63 64 static int 65 sysvipc_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 66 void *arg0, void *arg1, void *arg2, void *arg3) 67 { 68 mode_t mask; 69 int ismember = 0; 70 struct ipc_perm *perm; 71 int mode; 72 enum kauth_system_req req; 73 74 req = (enum kauth_system_req)arg0; 75 76 if (!(action == KAUTH_SYSTEM_SYSVIPC && 77 req == KAUTH_REQ_SYSTEM_SYSVIPC_BYPASS)) 78 return KAUTH_RESULT_DEFER; 79 80 perm = arg1; 81 mode = (int)(uintptr_t)arg2; 82 83 if (mode == IPC_M) { 84 if (kauth_cred_geteuid(cred) == perm->uid || 85 kauth_cred_geteuid(cred) == perm->cuid) 86 return (KAUTH_RESULT_ALLOW); 87 return (KAUTH_RESULT_DEFER); /* EPERM */ 88 } 89 90 mask = 0; 91 92 if (kauth_cred_geteuid(cred) == perm->uid || 93 kauth_cred_geteuid(cred) == perm->cuid) { 94 if (mode & IPC_R) 95 mask |= S_IRUSR; 96 if (mode & IPC_W) 97 mask |= S_IWUSR; 98 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 99 } 100 101 if (kauth_cred_getegid(cred) == perm->gid || 102 (kauth_cred_ismember_gid(cred, perm->gid, &ismember) == 0 && ismember) || 103 kauth_cred_getegid(cred) == perm->cgid || 104 (kauth_cred_ismember_gid(cred, perm->cgid, &ismember) == 0 && ismember)) { 105 if (mode & IPC_R) 106 mask |= S_IRGRP; 107 if (mode & IPC_W) 108 mask |= S_IWGRP; 109 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 110 } 111 112 if (mode & IPC_R) 113 mask |= S_IROTH; 114 if (mode & IPC_W) 115 mask |= S_IWOTH; 116 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 117 } 118 119 /* 120 * Check for ipc permission 121 */ 122 123 int 124 ipcperm(kauth_cred_t cred, struct ipc_perm *perm, int mode) 125 { 126 int error; 127 128 error = kauth_authorize_system(cred, KAUTH_SYSTEM_SYSVIPC, 129 KAUTH_REQ_SYSTEM_SYSVIPC_BYPASS, perm, KAUTH_ARG(mode), NULL); 130 if (error == 0) 131 return (0); 132 133 /* Adjust EPERM and EACCES errors until there's a better way to do this. */ 134 if (mode != IPC_M) 135 error = EACCES; 136 137 return error; 138 } 139 140 void 141 sysvipcinit(void) 142 { 143 144 if (sysvipc_listener != NULL) 145 return; 146 147 sysvipc_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM, 148 sysvipc_listener_cb, NULL); 149 } 150 151 static int 152 sysctl_kern_sysvipc(SYSCTLFN_ARGS) 153 { 154 void *where = oldp; 155 size_t sz, *sizep = oldlenp; 156 #ifdef SYSVMSG 157 struct msg_sysctl_info *msgsi = NULL; 158 #endif 159 #ifdef SYSVSEM 160 struct sem_sysctl_info *semsi = NULL; 161 #endif 162 #ifdef SYSVSHM 163 struct shm_sysctl_info *shmsi = NULL; 164 #endif 165 size_t infosize, dssize, tsize, buflen; 166 void *bf = NULL; 167 char *start; 168 int32_t nds; 169 int i, error, ret; 170 171 #ifdef COMPAT_50 172 switch ((error = sysctl_kern_sysvipc50(SYSCTLFN_CALL(rnode)))) { 173 case 0: 174 return 0; 175 case EPASSTHROUGH: 176 break; 177 default: 178 return error; 179 } 180 #endif 181 if (namelen != 1) 182 return EINVAL; 183 184 start = where; 185 buflen = *sizep; 186 187 switch (*name) { 188 case KERN_SYSVIPC_MSG_INFO: 189 #ifdef SYSVMSG 190 infosize = sizeof(msgsi->msginfo); 191 nds = msginfo.msgmni; 192 dssize = sizeof(msgsi->msgids[0]); 193 break; 194 #else 195 return EINVAL; 196 #endif 197 case KERN_SYSVIPC_SEM_INFO: 198 #ifdef SYSVSEM 199 infosize = sizeof(semsi->seminfo); 200 nds = seminfo.semmni; 201 dssize = sizeof(semsi->semids[0]); 202 break; 203 #else 204 return EINVAL; 205 #endif 206 case KERN_SYSVIPC_SHM_INFO: 207 #ifdef SYSVSHM 208 infosize = sizeof(shmsi->shminfo); 209 nds = shminfo.shmmni; 210 dssize = sizeof(shmsi->shmids[0]); 211 break; 212 #else 213 return EINVAL; 214 #endif 215 default: 216 return EINVAL; 217 } 218 /* 219 * Round infosize to 64 bit boundary if requesting more than just 220 * the info structure or getting the total data size. 221 */ 222 if (where == NULL || *sizep > infosize) 223 infosize = roundup(infosize, sizeof(quad_t)); 224 tsize = infosize + nds * dssize; 225 226 /* Return just the total size required. */ 227 if (where == NULL) { 228 *sizep = tsize; 229 return 0; 230 } 231 232 /* Not enough room for even the info struct. */ 233 if (buflen < infosize) { 234 *sizep = 0; 235 return ENOMEM; 236 } 237 sz = min(tsize, buflen); 238 bf = kmem_zalloc(sz, KM_SLEEP); 239 240 switch (*name) { 241 #ifdef SYSVMSG 242 case KERN_SYSVIPC_MSG_INFO: 243 msgsi = (struct msg_sysctl_info *)bf; 244 msgsi->msginfo = msginfo; 245 break; 246 #endif 247 #ifdef SYSVSEM 248 case KERN_SYSVIPC_SEM_INFO: 249 semsi = (struct sem_sysctl_info *)bf; 250 semsi->seminfo = seminfo; 251 break; 252 #endif 253 #ifdef SYSVSHM 254 case KERN_SYSVIPC_SHM_INFO: 255 shmsi = (struct shm_sysctl_info *)bf; 256 shmsi->shminfo = shminfo; 257 break; 258 #endif 259 } 260 buflen -= infosize; 261 262 ret = 0; 263 if (buflen > 0) { 264 /* Fill in the IPC data structures. */ 265 for (i = 0; i < nds; i++) { 266 if (buflen < dssize) { 267 ret = ENOMEM; 268 break; 269 } 270 switch (*name) { 271 #ifdef SYSVMSG 272 case KERN_SYSVIPC_MSG_INFO: 273 mutex_enter(&msgmutex); 274 SYSCTL_FILL_MSG(msqs[i].msq_u, msgsi->msgids[i]); 275 mutex_exit(&msgmutex); 276 break; 277 #endif 278 #ifdef SYSVSEM 279 case KERN_SYSVIPC_SEM_INFO: 280 SYSCTL_FILL_SEM(sema[i], semsi->semids[i]); 281 break; 282 #endif 283 #ifdef SYSVSHM 284 case KERN_SYSVIPC_SHM_INFO: 285 SYSCTL_FILL_SHM(shmsegs[i], shmsi->shmids[i]); 286 break; 287 #endif 288 } 289 buflen -= dssize; 290 } 291 } 292 *sizep -= buflen; 293 error = copyout(bf, start, *sizep); 294 /* If copyout succeeded, use return code set earlier. */ 295 if (error == 0) 296 error = ret; 297 if (bf) 298 kmem_free(bf, sz); 299 return error; 300 } 301 302 SYSCTL_SETUP(sysctl_ipc_setup, "sysctl kern.ipc subtree setup") 303 { 304 305 sysctl_createv(clog, 0, NULL, NULL, 306 CTLFLAG_PERMANENT, 307 CTLTYPE_NODE, "ipc", 308 SYSCTL_DESCR("SysV IPC options"), 309 NULL, 0, NULL, 0, 310 CTL_KERN, KERN_SYSVIPC, CTL_EOL); 311 312 sysctl_createv(clog, 0, NULL, NULL, 313 CTLFLAG_PERMANENT, 314 CTLTYPE_STRUCT, "sysvipc_info", 315 SYSCTL_DESCR("System V style IPC information"), 316 sysctl_kern_sysvipc, 0, NULL, 0, 317 CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_INFO, CTL_EOL); 318 } 319
Indexes created Wed Sep 24 22:09:59 GMT 2025