sysv_ipc.c revision 1.32.16.4
1 /* $NetBSD: sysv_ipc.c,v 1.32.16.4 2018/04/17 21:59:27 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 1.32.16.4 2018/04/17 21:59:27 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/compat_sysv_mod.h> /* for sysctl routine vector */ 66 67 int (*vec_sysvipc50_sysctl)(SYSCTLFN_PROTO); 68 69 /* 70 * Values in support of System V compatible shared memory. XXX 71 * (originally located in sys/conf/param.c) 72 */ 73 #ifdef SYSVSHM 74 #if !defined(SHMMAX) && defined(SHMMAXPGS) 75 #define SHMMAX SHMMAXPGS /* shminit() performs a `*= PAGE_SIZE' */ 76 #elif !defined(SHMMAX) 77 #define SHMMAX 0 78 #endif 79 #ifndef SHMMIN 80 #define SHMMIN 1 81 #endif 82 #ifndef SHMMNI 83 #define SHMMNI 128 /* <64k, see IPCID_TO_IX in ipc.h */ 84 #endif 85 #ifndef SHMSEG 86 #define SHMSEG 128 87 #endif 88 89 struct shminfo shminfo = { 90 SHMMAX, 91 SHMMIN, 92 SHMMNI, 93 SHMSEG, 94 0 95 }; 96 #endif 97 98 /* 99 * Values in support of System V compatible semaphores. 100 */ 101 #ifdef SYSVSEM 102 struct seminfo seminfo = { 103 SEMMAP, /* # of entries in semaphore map */ 104 SEMMNI, /* # of semaphore identifiers */ 105 SEMMNS, /* # of semaphores in system */ 106 SEMMNU, /* # of undo structures in system */ 107 SEMMSL, /* max # of semaphores per id */ 108 SEMOPM, /* max # of operations per semop call */ 109 SEMUME, /* max # of undo entries per process */ 110 SEMUSZ, /* size in bytes of undo structure */ 111 SEMVMX, /* semaphore maximum value */ 112 SEMAEM /* adjust on exit max value */ 113 }; 114 #endif 115 116 /* 117 * Values in support of System V compatible messages. 118 */ 119 #ifdef SYSVMSG 120 struct msginfo msginfo = { 121 MSGMAX, /* max chars in a message */ 122 MSGMNI, /* # of message queue identifiers */ 123 MSGMNB, /* max chars in a queue */ 124 MSGTQL, /* max messages in system */ 125 MSGSSZ, /* size of a message segment */ 126 /* (must be small power of 2 greater than 4) */ 127 MSGSEG /* number of message segments */ 128 }; 129 #endif 130 131 MODULE(MODULE_CLASS_EXEC, sysv_ipc, NULL); 132 133 SYSCTL_SETUP_PROTO(sysctl_ipc_setup); 134 135 static struct sysctllog *sysctl_sysvipc_clog = NULL; 136 137 static const struct syscall_package sysvipc_syscalls[] = { 138 #if defined(SYSVSHM) 139 { SYS___shmctl50, 0, (sy_call_t *)sys___shmctl50 }, 140 { SYS_shmat, 0, (sy_call_t *)sys_shmat }, 141 { SYS_shmdt, 0, (sy_call_t *)sys_shmdt }, 142 { SYS_shmget, 0, (sy_call_t *)sys_shmget }, 143 #endif /* SYSVSHM */ 144 145 #if defined(SYSVSEM) 146 { SYS_____semctl50, 0, (sy_call_t *)sys_____semctl50 }, 147 { SYS_semget, 0, (sy_call_t *)sys_semget }, 148 { SYS_semop, 0, (sy_call_t *)sys_semop }, 149 { SYS_semconfig, 0, (sy_call_t *)sys_semconfig }, 150 #endif /* SYSVSEM */ 151 152 #if defined(SYSVMSG) 153 { SYS___msgctl50, 0, (sy_call_t *)sys___msgctl50 }, 154 { SYS_msgget, 0, (sy_call_t *)sys_msgget }, 155 { SYS_msgsnd, 0, (sy_call_t *)sys_msgsnd }, 156 { SYS_msgrcv, 0, (sy_call_t *)sys_msgrcv }, 157 #endif /* SYSVMSG */ 158 { 0, 0, NULL } 159 }; 160 161 static int 162 sysv_ipc_modcmd(modcmd_t cmd, void *arg) 163 { 164 int error = 0; 165 166 switch (cmd) { 167 case MODULE_CMD_INIT: 168 /* Set up the kauth listener */ 169 sysvipcinit(); 170 171 #ifdef _MODULE 172 /* Set up the common sysctl tree */ 173 sysctl_ipc_setup(&sysctl_sysvipc_clog); 174 #endif 175 176 /* Link the system calls */ 177 error = syscall_establish(NULL, sysvipc_syscalls); 178 if (error) 179 sysvipcfini(); 180 181 /* 182 * Initialize each sub-component, including their 183 * sysctl data 184 */ 185 #ifdef SYSVSHM 186 shminit(&sysctl_sysvipc_clog); 187 #endif 188 #ifdef SYSVSEM 189 seminit(&sysctl_sysvipc_clog); 190 #endif 191 #ifdef SYSVMSG 192 msginit(&sysctl_sysvipc_clog); 193 #endif 194 break; 195 case MODULE_CMD_FINI: 196 /* 197 * Make sure no subcomponents are active. Each one 198 * tells us if it is busy, and if it was _not_ busy, 199 * we assume it has already done its own clean-up. 200 * So we might need to re-init any components that 201 * are successfully fini'd if we find one that is 202 * still busy. 203 */ 204 #ifdef SYSVSHM 205 if (shmfini()) { 206 return EBUSY; 207 } 208 #endif 209 #ifdef SYSVSEM 210 if (semfini()) { 211 #ifdef SYSVSHM 212 shminit(NULL); 213 #endif 214 return EBUSY; 215 } 216 #endif 217 #ifdef SYSVMSG 218 if (msgfini()) { 219 #ifdef SYSVSEM 220 seminit(NULL); 221 #endif 222 #ifdef SYSVSHM 223 shminit(NULL); 224 #endif 225 return EBUSY; 226 } 227 #endif 228 229 /* Unlink the system calls. */ 230 error = syscall_disestablish(NULL, sysvipc_syscalls); 231 if (error) 232 return error; 233 234 #ifdef _MODULE 235 /* Remove the sysctl sub-trees */ 236 sysctl_teardown(&sysctl_sysvipc_clog); 237 #endif 238 239 /* Remove the kauth listener */ 240 sysvipcfini(); 241 break; 242 default: 243 return ENOTTY; 244 } 245 return error; 246 } 247 248 static kauth_listener_t sysvipc_listener = NULL; 249 250 static int 251 sysvipc_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 252 void *arg0, void *arg1, void *arg2, void *arg3) 253 { 254 mode_t mask; 255 int ismember = 0; 256 struct ipc_perm *perm; 257 int mode; 258 enum kauth_system_req req; 259 260 req = (enum kauth_system_req)arg0; 261 262 if (!(action == KAUTH_SYSTEM_SYSVIPC && 263 req == KAUTH_REQ_SYSTEM_SYSVIPC_BYPASS)) 264 return KAUTH_RESULT_DEFER; 265 266 perm = arg1; 267 mode = (int)(uintptr_t)arg2; 268 269 if (mode == IPC_M) { 270 if (kauth_cred_geteuid(cred) == perm->uid || 271 kauth_cred_geteuid(cred) == perm->cuid) 272 return (KAUTH_RESULT_ALLOW); 273 return (KAUTH_RESULT_DEFER); /* EPERM */ 274 } 275 276 mask = 0; 277 278 if (kauth_cred_geteuid(cred) == perm->uid || 279 kauth_cred_geteuid(cred) == perm->cuid) { 280 if (mode & IPC_R) 281 mask |= S_IRUSR; 282 if (mode & IPC_W) 283 mask |= S_IWUSR; 284 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 285 } 286 287 if (kauth_cred_getegid(cred) == perm->gid || 288 (kauth_cred_ismember_gid(cred, perm->gid, &ismember) == 0 && ismember) || 289 kauth_cred_getegid(cred) == perm->cgid || 290 (kauth_cred_ismember_gid(cred, perm->cgid, &ismember) == 0 && ismember)) { 291 if (mode & IPC_R) 292 mask |= S_IRGRP; 293 if (mode & IPC_W) 294 mask |= S_IWGRP; 295 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 296 } 297 298 if (mode & IPC_R) 299 mask |= S_IROTH; 300 if (mode & IPC_W) 301 mask |= S_IWOTH; 302 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 303 } 304 305 /* 306 * Check for ipc permission 307 */ 308 309 int 310 ipcperm(kauth_cred_t cred, struct ipc_perm *perm, int mode) 311 { 312 int error; 313 314 error = kauth_authorize_system(cred, KAUTH_SYSTEM_SYSVIPC, 315 KAUTH_REQ_SYSTEM_SYSVIPC_BYPASS, perm, KAUTH_ARG(mode), NULL); 316 if (error == 0) 317 return (0); 318 319 /* Adjust EPERM and EACCES errors until there's a better way to do this. */ 320 if (mode != IPC_M) 321 error = EACCES; 322 323 return error; 324 } 325 326 void 327 sysvipcfini(void) 328 { 329 330 KASSERT(sysvipc_listener != NULL); 331 kauth_unlisten_scope(sysvipc_listener); 332 sysvipc_listener = NULL; 333 } 334 335 void 336 sysvipcinit(void) 337 { 338 339 KASSERT(sysvipc_listener == NULL); 340 341 sysvipc_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM, 342 sysvipc_listener_cb, NULL); 343 } 344 345 /* Vector the old 50 sysctl stuff */ 346 347 static int stub_sysvipc50_sysctl(SYSCTLFN_PROTO); 348 int (*vec_sysvipc50_sysctl)(SYSCTLFN_PROTO) = stub_sysvipc50_sysctl; 349 350 static int 351 stub_sysvipc50_sysctl(SYSCTLFN_ARGS) 352 { 353 return EPASSTHROUGH; 354 } 355 356 static int 357 sysctl_kern_sysvipc(SYSCTLFN_ARGS) 358 { 359 void *where = oldp; 360 size_t sz, *sizep = oldlenp; 361 #ifdef SYSVMSG 362 struct msg_sysctl_info *msgsi = NULL; 363 #endif 364 #ifdef SYSVSEM 365 struct sem_sysctl_info *semsi = NULL; 366 #endif 367 #ifdef SYSVSHM 368 struct shm_sysctl_info *shmsi = NULL; 369 #endif 370 size_t infosize, dssize, tsize, buflen; 371 void *bf = NULL; 372 char *start; 373 int32_t nds; 374 int i, error, ret; 375 376 /* 377 * If present, call the compat sysctl() code. If it handles the request 378 * completely (either success or error), return. Otherwise fallthrough 379 * to the non-compat sysctl code. 380 */ 381 382 error = (*vec_sysvipc50_sysctl)(SYSCTLFN_CALL(rnode)); 383 if (error != EPASSTHROUGH) 384 return error; 385 386 if (namelen != 1) 387 return EINVAL; 388 389 start = where; 390 buflen = *sizep; 391 392 switch (*name) { 393 case KERN_SYSVIPC_MSG_INFO: 394 #ifdef SYSVMSG 395 infosize = sizeof(msgsi->msginfo); 396 nds = msginfo.msgmni; 397 dssize = sizeof(msgsi->msgids[0]); 398 break; 399 #else 400 return EINVAL; 401 #endif 402 case KERN_SYSVIPC_SEM_INFO: 403 #ifdef SYSVSEM 404 infosize = sizeof(semsi->seminfo); 405 nds = seminfo.semmni; 406 dssize = sizeof(semsi->semids[0]); 407 break; 408 #else 409 return EINVAL; 410 #endif 411 case KERN_SYSVIPC_SHM_INFO: 412 #ifdef SYSVSHM 413 infosize = sizeof(shmsi->shminfo); 414 nds = shminfo.shmmni; 415 dssize = sizeof(shmsi->shmids[0]); 416 break; 417 #else 418 return EINVAL; 419 #endif 420 default: 421 return EINVAL; 422 } 423 /* 424 * Round infosize to 64 bit boundary if requesting more than just 425 * the info structure or getting the total data size. 426 */ 427 if (where == NULL || *sizep > infosize) 428 infosize = roundup(infosize, sizeof(quad_t)); 429 tsize = infosize + nds * dssize; 430 431 /* Return just the total size required. */ 432 if (where == NULL) { 433 *sizep = tsize; 434 return 0; 435 } 436 437 /* Not enough room for even the info struct. */ 438 if (buflen < infosize) { 439 *sizep = 0; 440 return ENOMEM; 441 } 442 sz = min(tsize, buflen); 443 bf = kmem_zalloc(sz, KM_SLEEP); 444 445 switch (*name) { 446 #ifdef SYSVMSG 447 case KERN_SYSVIPC_MSG_INFO: 448 msgsi = (struct msg_sysctl_info *)bf; 449 msgsi->msginfo = msginfo; 450 break; 451 #endif 452 #ifdef SYSVSEM 453 case KERN_SYSVIPC_SEM_INFO: 454 semsi = (struct sem_sysctl_info *)bf; 455 semsi->seminfo = seminfo; 456 break; 457 #endif 458 #ifdef SYSVSHM 459 case KERN_SYSVIPC_SHM_INFO: 460 shmsi = (struct shm_sysctl_info *)bf; 461 shmsi->shminfo = shminfo; 462 break; 463 #endif 464 } 465 buflen -= infosize; 466 467 ret = 0; 468 if (buflen > 0) { 469 /* Fill in the IPC data structures. */ 470 for (i = 0; i < nds; i++) { 471 if (buflen < dssize) { 472 ret = ENOMEM; 473 break; 474 } 475 switch (*name) { 476 #ifdef SYSVMSG 477 case KERN_SYSVIPC_MSG_INFO: 478 mutex_enter(&msgmutex); 479 SYSCTL_FILL_MSG(msqs[i].msq_u, msgsi->msgids[i]); 480 mutex_exit(&msgmutex); 481 break; 482 #endif 483 #ifdef SYSVSEM 484 case KERN_SYSVIPC_SEM_INFO: 485 SYSCTL_FILL_SEM(sema[i], semsi->semids[i]); 486 break; 487 #endif 488 #ifdef SYSVSHM 489 case KERN_SYSVIPC_SHM_INFO: 490 SYSCTL_FILL_SHM(shmsegs[i], shmsi->shmids[i]); 491 break; 492 #endif 493 } 494 buflen -= dssize; 495 } 496 } 497 *sizep -= buflen; 498 error = copyout(bf, start, *sizep); 499 /* If copyout succeeded, use return code set earlier. */ 500 if (error == 0) 501 error = ret; 502 if (bf) 503 kmem_free(bf, sz); 504 return error; 505 } 506 507 SYSCTL_SETUP(sysctl_ipc_setup, "sysctl kern.ipc subtree setup") 508 { 509 510 sysctl_createv(clog, 0, NULL, NULL, 511 CTLFLAG_PERMANENT, 512 CTLTYPE_NODE, "ipc", 513 SYSCTL_DESCR("SysV IPC options"), 514 NULL, 0, NULL, 0, 515 CTL_KERN, KERN_SYSVIPC, CTL_EOL); 516 517 sysctl_createv(clog, 0, NULL, NULL, 518 CTLFLAG_PERMANENT, 519 CTLTYPE_STRUCT, "sysvipc_info", 520 SYSCTL_DESCR("System V style IPC information"), 521 sysctl_kern_sysvipc, 0, NULL, 0, 522 CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_INFO, CTL_EOL); 523 } 524
Indexes created Wed Sep 24 05:09:52 GMT 2025