sysv_ipc.c revision 1.31
1 /* $NetBSD: sysv_ipc.c,v 1.31 2015/12/03 02:51:00 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 1.31 2015/12/03 02:51:00 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 /* 66 * Values in support of System V compatible shared memory. XXX 67 * (originally located in sys/conf/param.c) 68 */ 69 #ifdef SYSVSHM 70 #if !defined(SHMMAX) && defined(SHMMAXPGS) 71 #define SHMMAX SHMMAXPGS /* shminit() performs a `*= PAGE_SIZE' */ 72 #elif !defined(SHMMAX) 73 #define SHMMAX 0 74 #endif 75 #ifndef SHMMIN 76 #define SHMMIN 1 77 #endif 78 #ifndef SHMMNI 79 #define SHMMNI 128 /* <64k, see IPCID_TO_IX in ipc.h */ 80 #endif 81 #ifndef SHMSEG 82 #define SHMSEG 128 83 #endif 84 85 struct shminfo shminfo = { 86 SHMMAX, 87 SHMMIN, 88 SHMMNI, 89 SHMSEG, 90 0 91 }; 92 #endif 93 94 /* 95 * Values in support of System V compatible semaphores. 96 */ 97 #ifdef SYSVSEM 98 struct seminfo seminfo = { 99 SEMMAP, /* # of entries in semaphore map */ 100 SEMMNI, /* # of semaphore identifiers */ 101 SEMMNS, /* # of semaphores in system */ 102 SEMMNU, /* # of undo structures in system */ 103 SEMMSL, /* max # of semaphores per id */ 104 SEMOPM, /* max # of operations per semop call */ 105 SEMUME, /* max # of undo entries per process */ 106 SEMUSZ, /* size in bytes of undo structure */ 107 SEMVMX, /* semaphore maximum value */ 108 SEMAEM /* adjust on exit max value */ 109 }; 110 #endif 111 112 /* 113 * Values in support of System V compatible messages. 114 */ 115 #ifdef SYSVMSG 116 struct msginfo msginfo = { 117 MSGMAX, /* max chars in a message */ 118 MSGMNI, /* # of message queue identifiers */ 119 MSGMNB, /* max chars in a queue */ 120 MSGTQL, /* max messages in system */ 121 MSGSSZ, /* size of a message segment */ 122 /* (must be small power of 2 greater than 4) */ 123 MSGSEG /* number of message segments */ 124 }; 125 #endif 126 127 #if defined(COMPAT_50) 128 int sysctl_kern_sysvipc50(SYSCTLFN_PROTO); 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 #if defined(COMPAT_10) && !defined(_LP64) 144 { SYS_compat_10_oshmsys, 0, (sy_call_t *)compat_10_sys_shmsys }, 145 #endif 146 #if defined(COMPAT_14) 147 { SYS_compat_14_shmctl, 0, (sy_call_t *)compat_14_sys_shmctl }, 148 #endif 149 #if defined(COMPAT_50) 150 { SYS_compat_50___shmctl13, 0, (sy_call_t *)compat_50_sys___shmctl13 }, 151 #endif 152 #endif /* SYSVSHM */ 153 154 #if defined(SYSVSEM) 155 { SYS_____semctl50, 0, (sy_call_t *)sys_____semctl50 }, 156 { SYS_semget, 0, (sy_call_t *)sys_semget }, 157 { SYS_semop, 0, (sy_call_t *)sys_semop }, 158 { SYS_semconfig, 0, (sy_call_t *)sys_semconfig }, 159 #if defined(COMPAT_10) && !defined(_LP64) 160 { SYS_compat_10_osemsys, 0, (sy_call_t *)compat_10_sys_semsys }, 161 #endif 162 #if defined(COMPAT_14) 163 { SYS_compat_14___semctl, 0, (sy_call_t *)compat_14_sys___semctl }, 164 #endif 165 #if defined(COMPAT_50) 166 { SYS_compat_50_____semctl13, 0, (sy_call_t *)compat_50_sys_____semctl13 }, 167 #endif 168 #endif /* SYSVSEM */ 169 170 #if defined(SYSVMSG) 171 { SYS___msgctl50, 0, (sy_call_t *)sys___msgctl50 }, 172 { SYS_msgget, 0, (sy_call_t *)sys_msgget }, 173 { SYS_msgsnd, 0, (sy_call_t *)sys_msgsnd }, 174 { SYS_msgrcv, 0, (sy_call_t *)sys_msgrcv }, 175 #if defined(COMPAT_10) && !defined(_LP64) 176 { SYS_compat_10_omsgsys, 0, (sy_call_t *)compat_10_sys_msgsys }, 177 #endif 178 #if defined(COMPAT_14) 179 { SYS_compat_14_msgctl, 0, (sy_call_t *)compat_14_sys_msgctl }, 180 #endif 181 #if defined(COMPAT_50) 182 { SYS_compat_50___msgctl13, 0, (sy_call_t *)compat_50_sys___msgctl13 }, 183 #endif 184 #endif /* SYSVMSG */ 185 { 0, 0, NULL } 186 }; 187 188 static int 189 sysv_ipc_modcmd(modcmd_t cmd, void *arg) 190 { 191 int error = 0; 192 193 switch (cmd) { 194 case MODULE_CMD_INIT: 195 /* Set up the kauth listener */ 196 sysvipcinit(); 197 198 #ifdef _MODULE 199 /* Set up the common sysctl tree */ 200 sysctl_ipc_setup(&sysctl_sysvipc_clog); 201 #endif 202 203 /* Link the system calls */ 204 error = syscall_establish(NULL, sysvipc_syscalls); 205 if (error) 206 sysvipcfini(); 207 208 /* 209 * Initialize each sub-component, including their 210 * sysctl data 211 */ 212 #ifdef SYSVSHM 213 shminit(&sysctl_sysvipc_clog); 214 #endif 215 #ifdef SYSVSEM 216 seminit(&sysctl_sysvipc_clog); 217 #endif 218 #ifdef SYSVMSG 219 msginit(&sysctl_sysvipc_clog); 220 #endif 221 break; 222 case MODULE_CMD_FINI: 223 /* 224 * Make sure no subcomponents are active. Each one 225 * tells us if it is busy, and if it was _not_ busy, 226 * we assume it has already done its own clean-up. 227 * So we might need to re-init any components that 228 * are successfully fini'd if we find one that is 229 * still busy. 230 */ 231 #ifdef SYSVSHM 232 if (shmfini()) { 233 return EBUSY; 234 } 235 #endif 236 #ifdef SYSVSEM 237 if (semfini()) { 238 #ifdef SYSVSHM 239 shminit(NULL); 240 #endif 241 return EBUSY; 242 } 243 #endif 244 #ifdef SYSVMSG 245 if (msgfini()) { 246 #ifdef SYSVSEM 247 seminit(NULL); 248 #endif 249 #ifdef SYSVSHM 250 shminit(NULL); 251 #endif 252 return EBUSY; 253 } 254 #endif 255 256 /* Unlink the system calls. */ 257 error = syscall_disestablish(NULL, sysvipc_syscalls); 258 if (error) 259 return error; 260 261 #ifdef _MODULE 262 /* Remove the sysctl sub-trees */ 263 sysctl_teardown(&sysctl_sysvipc_clog); 264 #endif 265 266 /* Remove the kauth listener */ 267 sysvipcfini(); 268 break; 269 default: 270 return ENOTTY; 271 } 272 return error; 273 } 274 275 static kauth_listener_t sysvipc_listener = NULL; 276 277 static int 278 sysvipc_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 279 void *arg0, void *arg1, void *arg2, void *arg3) 280 { 281 mode_t mask; 282 int ismember = 0; 283 struct ipc_perm *perm; 284 int mode; 285 enum kauth_system_req req; 286 287 req = (enum kauth_system_req)arg0; 288 289 if (!(action == KAUTH_SYSTEM_SYSVIPC && 290 req == KAUTH_REQ_SYSTEM_SYSVIPC_BYPASS)) 291 return KAUTH_RESULT_DEFER; 292 293 perm = arg1; 294 mode = (int)(uintptr_t)arg2; 295 296 if (mode == IPC_M) { 297 if (kauth_cred_geteuid(cred) == perm->uid || 298 kauth_cred_geteuid(cred) == perm->cuid) 299 return (KAUTH_RESULT_ALLOW); 300 return (KAUTH_RESULT_DEFER); /* EPERM */ 301 } 302 303 mask = 0; 304 305 if (kauth_cred_geteuid(cred) == perm->uid || 306 kauth_cred_geteuid(cred) == perm->cuid) { 307 if (mode & IPC_R) 308 mask |= S_IRUSR; 309 if (mode & IPC_W) 310 mask |= S_IWUSR; 311 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 312 } 313 314 if (kauth_cred_getegid(cred) == perm->gid || 315 (kauth_cred_ismember_gid(cred, perm->gid, &ismember) == 0 && ismember) || 316 kauth_cred_getegid(cred) == perm->cgid || 317 (kauth_cred_ismember_gid(cred, perm->cgid, &ismember) == 0 && ismember)) { 318 if (mode & IPC_R) 319 mask |= S_IRGRP; 320 if (mode & IPC_W) 321 mask |= S_IWGRP; 322 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 323 } 324 325 if (mode & IPC_R) 326 mask |= S_IROTH; 327 if (mode & IPC_W) 328 mask |= S_IWOTH; 329 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 330 } 331 332 /* 333 * Check for ipc permission 334 */ 335 336 int 337 ipcperm(kauth_cred_t cred, struct ipc_perm *perm, int mode) 338 { 339 int error; 340 341 error = kauth_authorize_system(cred, KAUTH_SYSTEM_SYSVIPC, 342 KAUTH_REQ_SYSTEM_SYSVIPC_BYPASS, perm, KAUTH_ARG(mode), NULL); 343 if (error == 0) 344 return (0); 345 346 /* Adjust EPERM and EACCES errors until there's a better way to do this. */ 347 if (mode != IPC_M) 348 error = EACCES; 349 350 return error; 351 } 352 353 void 354 sysvipcfini(void) 355 { 356 357 KASSERT(sysvipc_listener != NULL); 358 kauth_unlisten_scope(sysvipc_listener); 359 } 360 361 void 362 sysvipcinit(void) 363 { 364 365 KASSERT(sysvipc_listener == NULL); 366 367 sysvipc_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM, 368 sysvipc_listener_cb, NULL); 369 } 370 371 static int 372 sysctl_kern_sysvipc(SYSCTLFN_ARGS) 373 { 374 void *where = oldp; 375 size_t sz, *sizep = oldlenp; 376 #ifdef SYSVMSG 377 struct msg_sysctl_info *msgsi = NULL; 378 #endif 379 #ifdef SYSVSEM 380 struct sem_sysctl_info *semsi = NULL; 381 #endif 382 #ifdef SYSVSHM 383 struct shm_sysctl_info *shmsi = NULL; 384 #endif 385 size_t infosize, dssize, tsize, buflen; 386 void *bf = NULL; 387 char *start; 388 int32_t nds; 389 int i, error, ret; 390 391 /* 392 * If present, call the compat sysctl() code. If it handles the request 393 * completely (either success or error), return. Otherwise fallthrough 394 * to the non-compat sysctl code. 395 */ 396 397 #if defined(COMPAT_50) 398 error = sysctl_kern_sysvipc50(SYSCTLFN_CALL(rnode)); 399 if (error != EPASSTHROUGH) 400 return error; 401 #endif 402 403 if (namelen != 1) 404 return EINVAL; 405 406 start = where; 407 buflen = *sizep; 408 409 switch (*name) { 410 case KERN_SYSVIPC_MSG_INFO: 411 #ifdef SYSVMSG 412 infosize = sizeof(msgsi->msginfo); 413 nds = msginfo.msgmni; 414 dssize = sizeof(msgsi->msgids[0]); 415 break; 416 #else 417 return EINVAL; 418 #endif 419 case KERN_SYSVIPC_SEM_INFO: 420 #ifdef SYSVSEM 421 infosize = sizeof(semsi->seminfo); 422 nds = seminfo.semmni; 423 dssize = sizeof(semsi->semids[0]); 424 break; 425 #else 426 return EINVAL; 427 #endif 428 case KERN_SYSVIPC_SHM_INFO: 429 #ifdef SYSVSHM 430 infosize = sizeof(shmsi->shminfo); 431 nds = shminfo.shmmni; 432 dssize = sizeof(shmsi->shmids[0]); 433 break; 434 #else 435 return EINVAL; 436 #endif 437 default: 438 return EINVAL; 439 } 440 /* 441 * Round infosize to 64 bit boundary if requesting more than just 442 * the info structure or getting the total data size. 443 */ 444 if (where == NULL || *sizep > infosize) 445 infosize = roundup(infosize, sizeof(quad_t)); 446 tsize = infosize + nds * dssize; 447 448 /* Return just the total size required. */ 449 if (where == NULL) { 450 *sizep = tsize; 451 return 0; 452 } 453 454 /* Not enough room for even the info struct. */ 455 if (buflen < infosize) { 456 *sizep = 0; 457 return ENOMEM; 458 } 459 sz = min(tsize, buflen); 460 bf = kmem_zalloc(sz, KM_SLEEP); 461 462 switch (*name) { 463 #ifdef SYSVMSG 464 case KERN_SYSVIPC_MSG_INFO: 465 msgsi = (struct msg_sysctl_info *)bf; 466 msgsi->msginfo = msginfo; 467 break; 468 #endif 469 #ifdef SYSVSEM 470 case KERN_SYSVIPC_SEM_INFO: 471 semsi = (struct sem_sysctl_info *)bf; 472 semsi->seminfo = seminfo; 473 break; 474 #endif 475 #ifdef SYSVSHM 476 case KERN_SYSVIPC_SHM_INFO: 477 shmsi = (struct shm_sysctl_info *)bf; 478 shmsi->shminfo = shminfo; 479 break; 480 #endif 481 } 482 buflen -= infosize; 483 484 ret = 0; 485 if (buflen > 0) { 486 /* Fill in the IPC data structures. */ 487 for (i = 0; i < nds; i++) { 488 if (buflen < dssize) { 489 ret = ENOMEM; 490 break; 491 } 492 switch (*name) { 493 #ifdef SYSVMSG 494 case KERN_SYSVIPC_MSG_INFO: 495 mutex_enter(&msgmutex); 496 SYSCTL_FILL_MSG(msqs[i].msq_u, msgsi->msgids[i]); 497 mutex_exit(&msgmutex); 498 break; 499 #endif 500 #ifdef SYSVSEM 501 case KERN_SYSVIPC_SEM_INFO: 502 SYSCTL_FILL_SEM(sema[i], semsi->semids[i]); 503 break; 504 #endif 505 #ifdef SYSVSHM 506 case KERN_SYSVIPC_SHM_INFO: 507 SYSCTL_FILL_SHM(shmsegs[i], shmsi->shmids[i]); 508 break; 509 #endif 510 } 511 buflen -= dssize; 512 } 513 } 514 *sizep -= buflen; 515 error = copyout(bf, start, *sizep); 516 /* If copyout succeeded, use return code set earlier. */ 517 if (error == 0) 518 error = ret; 519 if (bf) 520 kmem_free(bf, sz); 521 return error; 522 } 523 524 SYSCTL_SETUP(sysctl_ipc_setup, "sysctl kern.ipc subtree setup") 525 { 526 527 sysctl_createv(clog, 0, NULL, NULL, 528 CTLFLAG_PERMANENT, 529 CTLTYPE_NODE, "ipc", 530 SYSCTL_DESCR("SysV IPC options"), 531 NULL, 0, NULL, 0, 532 CTL_KERN, KERN_SYSVIPC, CTL_EOL); 533 534 sysctl_createv(clog, 0, NULL, NULL, 535 CTLFLAG_PERMANENT, 536 CTLTYPE_STRUCT, "sysvipc_info", 537 SYSCTL_DESCR("System V style IPC information"), 538 sysctl_kern_sysvipc, 0, NULL, 0, 539 CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_INFO, CTL_EOL); 540 } 541
Indexes created Thu Sep 25 02:09:54 GMT 2025