sysv_ipc.c revision 1.32.16.1
1 /* $NetBSD: sysv_ipc.c,v 1.32.16.1 2018/03/09 01:27:50 pgoyette 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 1.32.16.1 2018/03/09 01:27:50 pgoyette Exp $"); 34 35 #ifdef _KERNEL_OPT 36 #include "opt_sysv.h" 37 #include "opt_compat_netbsd.h" 38 #endif 39 40 #include <sys/syscall.h> 41 #include <sys/syscallargs.h> 42 #include <sys/syscallvar.h> 43 #include <sys/param.h> 44 #include <sys/kernel.h> 45 #include <sys/proc.h> 46 #include <sys/ipc.h> 47 #ifdef SYSVMSG 48 #include <sys/msg.h> 49 #endif 50 #ifdef SYSVSEM 51 #include <sys/sem.h> 52 #endif 53 #ifdef SYSVSHM 54 #include <sys/shm.h> 55 #endif 56 #include <sys/systm.h> 57 #include <sys/kmem.h> 58 #include <sys/module.h> 59 #include <sys/mount.h> 60 #include <sys/vnode.h> 61 #include <sys/stat.h> 62 #include <sys/sysctl.h> 63 #include <sys/kauth.h> 64 65 #include <compat/common/sysv_ipc_mod.h> /* for sysctl routine vector */ 66 67 /* 68 * Values in support of System V compatible shared memory. XXX 69 * (originally located in sys/conf/param.c) 70 */ 71 #ifdef SYSVSHM 72 #if !defined(SHMMAX) && defined(SHMMAXPGS) 73 #define SHMMAX SHMMAXPGS /* shminit() performs a `*= PAGE_SIZE' */ 74 #elif !defined(SHMMAX) 75 #define SHMMAX 0 76 #endif 77 #ifndef SHMMIN 78 #define SHMMIN 1 79 #endif 80 #ifndef SHMMNI 81 #define SHMMNI 128 /* <64k, see IPCID_TO_IX in ipc.h */ 82 #endif 83 #ifndef SHMSEG 84 #define SHMSEG 128 85 #endif 86 87 struct shminfo shminfo = { 88 SHMMAX, 89 SHMMIN, 90 SHMMNI, 91 SHMSEG, 92 0 93 }; 94 #endif 95 96 /* 97 * Values in support of System V compatible semaphores. 98 */ 99 #ifdef SYSVSEM 100 struct seminfo seminfo = { 101 SEMMAP, /* # of entries in semaphore map */ 102 SEMMNI, /* # of semaphore identifiers */ 103 SEMMNS, /* # of semaphores in system */ 104 SEMMNU, /* # of undo structures in system */ 105 SEMMSL, /* max # of semaphores per id */ 106 SEMOPM, /* max # of operations per semop call */ 107 SEMUME, /* max # of undo entries per process */ 108 SEMUSZ, /* size in bytes of undo structure */ 109 SEMVMX, /* semaphore maximum value */ 110 SEMAEM /* adjust on exit max value */ 111 }; 112 #endif 113 114 /* 115 * Values in support of System V compatible messages. 116 */ 117 #ifdef SYSVMSG 118 struct msginfo msginfo = { 119 MSGMAX, /* max chars in a message */ 120 MSGMNI, /* # of message queue identifiers */ 121 MSGMNB, /* max chars in a queue */ 122 MSGTQL, /* max messages in system */ 123 MSGSSZ, /* size of a message segment */ 124 /* (must be small power of 2 greater than 4) */ 125 MSGSEG /* number of message segments */ 126 }; 127 #endif 128 129 MODULE(MODULE_CLASS_EXEC, sysv_ipc, NULL); 130 131 SYSCTL_SETUP_PROTO(sysctl_ipc_setup); 132 133 static struct sysctllog *sysctl_sysvipc_clog = NULL; 134 135 static const struct syscall_package sysvipc_syscalls[] = { 136 #if defined(SYSVSHM) 137 { SYS___shmctl50, 0, (sy_call_t *)sys___shmctl50 }, 138 { SYS_shmat, 0, (sy_call_t *)sys_shmat }, 139 { SYS_shmdt, 0, (sy_call_t *)sys_shmdt }, 140 { SYS_shmget, 0, (sy_call_t *)sys_shmget }, 141 #endif /* SYSVSHM */ 142 143 #if defined(SYSVSEM) 144 { SYS_____semctl50, 0, (sy_call_t *)sys_____semctl50 }, 145 { SYS_semget, 0, (sy_call_t *)sys_semget }, 146 { SYS_semop, 0, (sy_call_t *)sys_semop }, 147 { SYS_semconfig, 0, (sy_call_t *)sys_semconfig }, 148 #endif /* SYSVSEM */ 149 150 #if defined(SYSVMSG) 151 { SYS___msgctl50, 0, (sy_call_t *)sys___msgctl50 }, 152 { SYS_msgget, 0, (sy_call_t *)sys_msgget }, 153 { SYS_msgsnd, 0, (sy_call_t *)sys_msgsnd }, 154 { SYS_msgrcv, 0, (sy_call_t *)sys_msgrcv }, 155 #endif /* SYSVMSG */ 156 { 0, 0, NULL } 157 }; 158 159 static int 160 sysv_ipc_modcmd(modcmd_t cmd, void *arg) 161 { 162 int error = 0; 163 164 switch (cmd) { 165 case MODULE_CMD_INIT: 166 /* Set up the kauth listener */ 167 sysvipcinit(); 168 169 #ifdef _MODULE 170 /* Set up the common sysctl tree */ 171 sysctl_ipc_setup(&sysctl_sysvipc_clog); 172 #endif 173 174 /* Link the system calls */ 175 error = syscall_establish(NULL, sysvipc_syscalls); 176 if (error) 177 sysvipcfini(); 178 179 /* 180 * Initialize each sub-component, including their 181 * sysctl data 182 */ 183 #ifdef SYSVSHM 184 shminit(&sysctl_sysvipc_clog); 185 #endif 186 #ifdef SYSVSEM 187 seminit(&sysctl_sysvipc_clog); 188 #endif 189 #ifdef SYSVMSG 190 msginit(&sysctl_sysvipc_clog); 191 #endif 192 break; 193 case MODULE_CMD_FINI: 194 /* 195 * Make sure no subcomponents are active. Each one 196 * tells us if it is busy, and if it was _not_ busy, 197 * we assume it has already done its own clean-up. 198 * So we might need to re-init any components that 199 * are successfully fini'd if we find one that is 200 * still busy. 201 */ 202 #ifdef SYSVSHM 203 if (shmfini()) { 204 return EBUSY; 205 } 206 #endif 207 #ifdef SYSVSEM 208 if (semfini()) { 209 #ifdef SYSVSHM 210 shminit(NULL); 211 #endif 212 return EBUSY; 213 } 214 #endif 215 #ifdef SYSVMSG 216 if (msgfini()) { 217 #ifdef SYSVSEM 218 seminit(NULL); 219 #endif 220 #ifdef SYSVSHM 221 shminit(NULL); 222 #endif 223 return EBUSY; 224 } 225 #endif 226 227 /* Unlink the system calls. */ 228 error = syscall_disestablish(NULL, sysvipc_syscalls); 229 if (error) 230 return error; 231 232 #ifdef _MODULE 233 /* Remove the sysctl sub-trees */ 234 sysctl_teardown(&sysctl_sysvipc_clog); 235 #endif 236 237 /* Remove the kauth listener */ 238 sysvipcfini(); 239 break; 240 default: 241 return ENOTTY; 242 } 243 return error; 244 } 245 246 static kauth_listener_t sysvipc_listener = NULL; 247 248 static int 249 sysvipc_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 250 void *arg0, void *arg1, void *arg2, void *arg3) 251 { 252 mode_t mask; 253 int ismember = 0; 254 struct ipc_perm *perm; 255 int mode; 256 enum kauth_system_req req; 257 258 req = (enum kauth_system_req)arg0; 259 260 if (!(action == KAUTH_SYSTEM_SYSVIPC && 261 req == KAUTH_REQ_SYSTEM_SYSVIPC_BYPASS)) 262 return KAUTH_RESULT_DEFER; 263 264 perm = arg1; 265 mode = (int)(uintptr_t)arg2; 266 267 if (mode == IPC_M) { 268 if (kauth_cred_geteuid(cred) == perm->uid || 269 kauth_cred_geteuid(cred) == perm->cuid) 270 return (KAUTH_RESULT_ALLOW); 271 return (KAUTH_RESULT_DEFER); /* EPERM */ 272 } 273 274 mask = 0; 275 276 if (kauth_cred_geteuid(cred) == perm->uid || 277 kauth_cred_geteuid(cred) == perm->cuid) { 278 if (mode & IPC_R) 279 mask |= S_IRUSR; 280 if (mode & IPC_W) 281 mask |= S_IWUSR; 282 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 283 } 284 285 if (kauth_cred_getegid(cred) == perm->gid || 286 (kauth_cred_ismember_gid(cred, perm->gid, &ismember) == 0 && ismember) || 287 kauth_cred_getegid(cred) == perm->cgid || 288 (kauth_cred_ismember_gid(cred, perm->cgid, &ismember) == 0 && ismember)) { 289 if (mode & IPC_R) 290 mask |= S_IRGRP; 291 if (mode & IPC_W) 292 mask |= S_IWGRP; 293 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 294 } 295 296 if (mode & IPC_R) 297 mask |= S_IROTH; 298 if (mode & IPC_W) 299 mask |= S_IWOTH; 300 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 301 } 302 303 /* 304 * Check for ipc permission 305 */ 306 307 int 308 ipcperm(kauth_cred_t cred, struct ipc_perm *perm, int mode) 309 { 310 int error; 311 312 error = kauth_authorize_system(cred, KAUTH_SYSTEM_SYSVIPC, 313 KAUTH_REQ_SYSTEM_SYSVIPC_BYPASS, perm, KAUTH_ARG(mode), NULL); 314 if (error == 0) 315 return (0); 316 317 /* Adjust EPERM and EACCES errors until there's a better way to do this. */ 318 if (mode != IPC_M) 319 error = EACCES; 320 321 return error; 322 } 323 324 void 325 sysvipcfini(void) 326 { 327 328 KASSERT(sysvipc_listener != NULL); 329 kauth_unlisten_scope(sysvipc_listener); 330 sysvipc_listener = NULL; 331 } 332 333 void 334 sysvipcinit(void) 335 { 336 337 KASSERT(sysvipc_listener == NULL); 338 339 sysvipc_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM, 340 sysvipc_listener_cb, NULL); 341 } 342 343 /* Vector the old 50 sysctl stuff */ 344 345 static int stub_sysvipc50_sysctl(SYSCTLFN_PROTO); 346 int (*vec_sysvipc50_sysctl)(SYSCTLFN_PROTO) = stub_sysvipc50_sysctl; 347 348 static int 349 stub_sysvipc50_sysctl(SYSCTLFN_ARGS) 350 { 351 return EPASSTHROUGH; 352 } 353 354 static int 355 sysctl_kern_sysvipc(SYSCTLFN_ARGS) 356 { 357 void *where = oldp; 358 size_t sz, *sizep = oldlenp; 359 #ifdef SYSVMSG 360 struct msg_sysctl_info *msgsi = NULL; 361 #endif 362 #ifdef SYSVSEM 363 struct sem_sysctl_info *semsi = NULL; 364 #endif 365 #ifdef SYSVSHM 366 struct shm_sysctl_info *shmsi = NULL; 367 #endif 368 size_t infosize, dssize, tsize, buflen; 369 void *bf = NULL; 370 char *start; 371 int32_t nds; 372 int i, error, ret; 373 374 /* 375 * If present, call the compat sysctl() code. If it handles the request 376 * completely (either success or error), return. Otherwise fallthrough 377 * to the non-compat sysctl code. 378 */ 379 380 error = (*vec_sysvipc50_sysctl)(SYSCTLFN_CALL(rnode)); 381 if (error != EPASSTHROUGH) 382 return error; 383 384 if (namelen != 1) 385 return EINVAL; 386 387 start = where; 388 buflen = *sizep; 389 390 switch (*name) { 391 case KERN_SYSVIPC_MSG_INFO: 392 #ifdef SYSVMSG 393 infosize = sizeof(msgsi->msginfo); 394 nds = msginfo.msgmni; 395 dssize = sizeof(msgsi->msgids[0]); 396 break; 397 #else 398 return EINVAL; 399 #endif 400 case KERN_SYSVIPC_SEM_INFO: 401 #ifdef SYSVSEM 402 infosize = sizeof(semsi->seminfo); 403 nds = seminfo.semmni; 404 dssize = sizeof(semsi->semids[0]); 405 break; 406 #else 407 return EINVAL; 408 #endif 409 case KERN_SYSVIPC_SHM_INFO: 410 #ifdef SYSVSHM 411 infosize = sizeof(shmsi->shminfo); 412 nds = shminfo.shmmni; 413 dssize = sizeof(shmsi->shmids[0]); 414 break; 415 #else 416 return EINVAL; 417 #endif 418 default: 419 return EINVAL; 420 } 421 /* 422 * Round infosize to 64 bit boundary if requesting more than just 423 * the info structure or getting the total data size. 424 */ 425 if (where == NULL || *sizep > infosize) 426 infosize = roundup(infosize, sizeof(quad_t)); 427 tsize = infosize + nds * dssize; 428 429 /* Return just the total size required. */ 430 if (where == NULL) { 431 *sizep = tsize; 432 return 0; 433 } 434 435 /* Not enough room for even the info struct. */ 436 if (buflen < infosize) { 437 *sizep = 0; 438 return ENOMEM; 439 } 440 sz = min(tsize, buflen); 441 bf = kmem_zalloc(sz, KM_SLEEP); 442 443 switch (*name) { 444 #ifdef SYSVMSG 445 case KERN_SYSVIPC_MSG_INFO: 446 msgsi = (struct msg_sysctl_info *)bf; 447 msgsi->msginfo = msginfo; 448 break; 449 #endif 450 #ifdef SYSVSEM 451 case KERN_SYSVIPC_SEM_INFO: 452 semsi = (struct sem_sysctl_info *)bf; 453 semsi->seminfo = seminfo; 454 break; 455 #endif 456 #ifdef SYSVSHM 457 case KERN_SYSVIPC_SHM_INFO: 458 shmsi = (struct shm_sysctl_info *)bf; 459 shmsi->shminfo = shminfo; 460 break; 461 #endif 462 } 463 buflen -= infosize; 464 465 ret = 0; 466 if (buflen > 0) { 467 /* Fill in the IPC data structures. */ 468 for (i = 0; i < nds; i++) { 469 if (buflen < dssize) { 470 ret = ENOMEM; 471 break; 472 } 473 switch (*name) { 474 #ifdef SYSVMSG 475 case KERN_SYSVIPC_MSG_INFO: 476 mutex_enter(&msgmutex); 477 SYSCTL_FILL_MSG(msqs[i].msq_u, msgsi->msgids[i]); 478 mutex_exit(&msgmutex); 479 break; 480 #endif 481 #ifdef SYSVSEM 482 case KERN_SYSVIPC_SEM_INFO: 483 SYSCTL_FILL_SEM(sema[i], semsi->semids[i]); 484 break; 485 #endif 486 #ifdef SYSVSHM 487 case KERN_SYSVIPC_SHM_INFO: 488 SYSCTL_FILL_SHM(shmsegs[i], shmsi->shmids[i]); 489 break; 490 #endif 491 } 492 buflen -= dssize; 493 } 494 } 495 *sizep -= buflen; 496 error = copyout(bf, start, *sizep); 497 /* If copyout succeeded, use return code set earlier. */ 498 if (error == 0) 499 error = ret; 500 if (bf) 501 kmem_free(bf, sz); 502 return error; 503 } 504 505 SYSCTL_SETUP(sysctl_ipc_setup, "sysctl kern.ipc subtree setup") 506 { 507 508 sysctl_createv(clog, 0, NULL, NULL, 509 CTLFLAG_PERMANENT, 510 CTLTYPE_NODE, "ipc", 511 SYSCTL_DESCR("SysV IPC options"), 512 NULL, 0, NULL, 0, 513 CTL_KERN, KERN_SYSVIPC, CTL_EOL); 514 515 sysctl_createv(clog, 0, NULL, NULL, 516 CTLFLAG_PERMANENT, 517 CTLTYPE_STRUCT, "sysvipc_info", 518 SYSCTL_DESCR("System V style IPC information"), 519 sysctl_kern_sysvipc, 0, NULL, 0, 520 CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_INFO, CTL_EOL); 521 } 522
Indexes created Wed Sep 24 15:09:51 GMT 2025