1 /* $NetBSD: sysv_ipc.c,v 1.21 2008/04/28 20:24:05 martin 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 1.21 2008/04/28 20:24:05 martin Exp $"); 34 35 #include "opt_sysv.h" 36 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/malloc.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 /* 59 * Check for ipc permission 60 */ 61 62 int 63 ipcperm(kauth_cred_t cred, struct ipc_perm *perm, int mode) 64 { 65 mode_t mask; 66 int ismember = 0; 67 68 if (kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER, NULL) == 0) 69 return (0); 70 71 if (mode == IPC_M) { 72 if (kauth_cred_geteuid(cred) == perm->uid || 73 kauth_cred_geteuid(cred) == perm->cuid) 74 return (0); 75 return (EPERM); 76 } 77 78 mask = 0; 79 80 if (kauth_cred_geteuid(cred) == perm->uid || 81 kauth_cred_geteuid(cred) == perm->cuid) { 82 if (mode & IPC_R) 83 mask |= S_IRUSR; 84 if (mode & IPC_W) 85 mask |= S_IWUSR; 86 return ((perm->mode & mask) == mask ? 0 : EACCES); 87 } 88 89 if (kauth_cred_getegid(cred) == perm->gid || 90 (kauth_cred_ismember_gid(cred, perm->gid, &ismember) == 0 && ismember) || 91 kauth_cred_getegid(cred) == perm->cgid || 92 (kauth_cred_ismember_gid(cred, perm->cgid, &ismember) == 0 && ismember)) { 93 if (mode & IPC_R) 94 mask |= S_IRGRP; 95 if (mode & IPC_W) 96 mask |= S_IWGRP; 97 return ((perm->mode & mask) == mask ? 0 : EACCES); 98 } 99 100 if (mode & IPC_R) 101 mask |= S_IROTH; 102 if (mode & IPC_W) 103 mask |= S_IWOTH; 104 return ((perm->mode & mask) == mask ? 0 : EACCES); 105 } 106 107 /* 108 * sysctl helper routine for kern.ipc.sysvipc_info subtree. 109 */ 110 111 #define FILL_PERM(src, dst) do { \ 112 (dst)._key = (src)._key; \ 113 (dst).uid = (src).uid; \ 114 (dst).gid = (src).gid; \ 115 (dst).cuid = (src).cuid; \ 116 (dst).cgid = (src).cgid; \ 117 (dst).mode = (src).mode; \ 118 (dst)._seq = (src)._seq; \ 119 } while (/*CONSTCOND*/ 0); 120 121 #define FILL_MSG(src, dst) do { \ 122 FILL_PERM((src).msg_perm, (dst).msg_perm); \ 123 (dst).msg_qnum = (src).msg_qnum; \ 124 (dst).msg_qbytes = (src).msg_qbytes; \ 125 (dst)._msg_cbytes = (src)._msg_cbytes; \ 126 (dst).msg_lspid = (src).msg_lspid; \ 127 (dst).msg_lrpid = (src).msg_lrpid; \ 128 (dst).msg_stime = (src).msg_stime; \ 129 (dst).msg_rtime = (src).msg_rtime; \ 130 (dst).msg_ctime = (src).msg_ctime; \ 131 } while (/*CONSTCOND*/ 0) 132 133 #define FILL_SEM(src, dst) do { \ 134 FILL_PERM((src).sem_perm, (dst).sem_perm); \ 135 (dst).sem_nsems = (src).sem_nsems; \ 136 (dst).sem_otime = (src).sem_otime; \ 137 (dst).sem_ctime = (src).sem_ctime; \ 138 } while (/*CONSTCOND*/ 0) 139 140 #define FILL_SHM(src, dst) do { \ 141 FILL_PERM((src).shm_perm, (dst).shm_perm); \ 142 (dst).shm_segsz = (src).shm_segsz; \ 143 (dst).shm_lpid = (src).shm_lpid; \ 144 (dst).shm_cpid = (src).shm_cpid; \ 145 (dst).shm_atime = (src).shm_atime; \ 146 (dst).shm_dtime = (src).shm_dtime; \ 147 (dst).shm_ctime = (src).shm_ctime; \ 148 (dst).shm_nattch = (src).shm_nattch; \ 149 } while (/*CONSTCOND*/ 0) 150 151 static int 152 sysctl_kern_sysvipc(SYSCTLFN_ARGS) 153 { 154 void *where = oldp; 155 size_t *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 if (namelen != 1) 172 return EINVAL; 173 174 start = where; 175 buflen = *sizep; 176 177 switch (*name) { 178 case KERN_SYSVIPC_MSG_INFO: 179 #ifdef SYSVMSG 180 infosize = sizeof(msgsi->msginfo); 181 nds = msginfo.msgmni; 182 dssize = sizeof(msgsi->msgids[0]); 183 break; 184 #else 185 return EINVAL; 186 #endif 187 case KERN_SYSVIPC_SEM_INFO: 188 #ifdef SYSVSEM 189 infosize = sizeof(semsi->seminfo); 190 nds = seminfo.semmni; 191 dssize = sizeof(semsi->semids[0]); 192 break; 193 #else 194 return EINVAL; 195 #endif 196 case KERN_SYSVIPC_SHM_INFO: 197 #ifdef SYSVSHM 198 infosize = sizeof(shmsi->shminfo); 199 nds = shminfo.shmmni; 200 dssize = sizeof(shmsi->shmids[0]); 201 break; 202 #else 203 return EINVAL; 204 #endif 205 default: 206 return EINVAL; 207 } 208 /* 209 * Round infosize to 64 bit boundary if requesting more than just 210 * the info structure or getting the total data size. 211 */ 212 if (where == NULL || *sizep > infosize) 213 infosize = roundup(infosize, sizeof(quad_t)); 214 tsize = infosize + nds * dssize; 215 216 /* Return just the total size required. */ 217 if (where == NULL) { 218 *sizep = tsize; 219 return 0; 220 } 221 222 /* Not enough room for even the info struct. */ 223 if (buflen < infosize) { 224 *sizep = 0; 225 return ENOMEM; 226 } 227 bf = malloc(min(tsize, buflen), M_TEMP, M_WAITOK | M_ZERO); 228 229 switch (*name) { 230 #ifdef SYSVMSG 231 case KERN_SYSVIPC_MSG_INFO: 232 msgsi = (struct msg_sysctl_info *)bf; 233 msgsi->msginfo = msginfo; 234 break; 235 #endif 236 #ifdef SYSVSEM 237 case KERN_SYSVIPC_SEM_INFO: 238 semsi = (struct sem_sysctl_info *)bf; 239 semsi->seminfo = seminfo; 240 break; 241 #endif 242 #ifdef SYSVSHM 243 case KERN_SYSVIPC_SHM_INFO: 244 shmsi = (struct shm_sysctl_info *)bf; 245 shmsi->shminfo = shminfo; 246 break; 247 #endif 248 } 249 buflen -= infosize; 250 251 ret = 0; 252 if (buflen > 0) { 253 /* Fill in the IPC data structures. */ 254 for (i = 0; i < nds; i++) { 255 if (buflen < dssize) { 256 ret = ENOMEM; 257 break; 258 } 259 switch (*name) { 260 #ifdef SYSVMSG 261 case KERN_SYSVIPC_MSG_INFO: 262 mutex_enter(&msgmutex); 263 FILL_MSG(msqs[i].msq_u, msgsi->msgids[i]); 264 mutex_exit(&msgmutex); 265 break; 266 #endif 267 #ifdef SYSVSEM 268 case KERN_SYSVIPC_SEM_INFO: 269 FILL_SEM(sema[i], semsi->semids[i]); 270 break; 271 #endif 272 #ifdef SYSVSHM 273 case KERN_SYSVIPC_SHM_INFO: 274 FILL_SHM(shmsegs[i], shmsi->shmids[i]); 275 break; 276 #endif 277 } 278 buflen -= dssize; 279 } 280 } 281 *sizep -= buflen; 282 error = copyout(bf, start, *sizep); 283 /* If copyout succeeded, use return code set earlier. */ 284 if (error == 0) 285 error = ret; 286 if (bf) 287 free(bf, M_TEMP); 288 return error; 289 } 290 291 #undef FILL_PERM 292 #undef FILL_MSG 293 #undef FILL_SEM 294 #undef FILL_SHM 295 296 SYSCTL_SETUP(sysctl_ipc_setup, "sysctl kern.ipc subtree setup") 297 { 298 sysctl_createv(clog, 0, NULL, NULL, 299 CTLFLAG_PERMANENT, 300 CTLTYPE_NODE, "kern", NULL, 301 NULL, 0, NULL, 0, 302 CTL_KERN, CTL_EOL); 303 304 sysctl_createv(clog, 0, NULL, NULL, 305 CTLFLAG_PERMANENT, 306 CTLTYPE_NODE, "ipc", 307 SYSCTL_DESCR("SysV IPC options"), 308 NULL, 0, NULL, 0, 309 CTL_KERN, KERN_SYSVIPC, CTL_EOL); 310 311 sysctl_createv(clog, 0, NULL, NULL, 312 CTLFLAG_PERMANENT, 313 CTLTYPE_STRUCT, "sysvipc_info", 314 SYSCTL_DESCR("System V style IPC information"), 315 sysctl_kern_sysvipc, 0, NULL, 0, 316 CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_INFO, CTL_EOL); 317 } 318