sysv_ipc.c revision 1.25.6.2
1 /* $NetBSD: sysv_ipc.c,v 1.25.6.2 2015/12/27 12:10:05 skrll 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 1.25.6.2 2015/12/27 12:10:05 skrll 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 sysvipc_listener = NULL; 360 } 361 362 void 363 sysvipcinit(void) 364 { 365 366 KASSERT(sysvipc_listener == NULL); 367 368 sysvipc_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM, 369 sysvipc_listener_cb, NULL); 370 } 371 372 static int 373 sysctl_kern_sysvipc(SYSCTLFN_ARGS) 374 { 375 void *where = oldp; 376 size_t sz, *sizep = oldlenp; 377 #ifdef SYSVMSG 378 struct msg_sysctl_info *msgsi = NULL; 379 #endif 380 #ifdef SYSVSEM 381 struct sem_sysctl_info *semsi = NULL; 382 #endif 383 #ifdef SYSVSHM 384 struct shm_sysctl_info *shmsi = NULL; 385 #endif 386 size_t infosize, dssize, tsize, buflen; 387 void *bf = NULL; 388 char *start; 389 int32_t nds; 390 int i, error, ret; 391 392 /* 393 * If present, call the compat sysctl() code. If it handles the request 394 * completely (either success or error), return. Otherwise fallthrough 395 * to the non-compat sysctl code. 396 */ 397 398 #if defined(COMPAT_50) 399 error = sysctl_kern_sysvipc50(SYSCTLFN_CALL(rnode)); 400 if (error != EPASSTHROUGH) 401 return error; 402 #endif 403 404 if (namelen != 1) 405 return EINVAL; 406 407 start = where; 408 buflen = *sizep; 409 410 switch (*name) { 411 case KERN_SYSVIPC_MSG_INFO: 412 #ifdef SYSVMSG 413 infosize = sizeof(msgsi->msginfo); 414 nds = msginfo.msgmni; 415 dssize = sizeof(msgsi->msgids[0]); 416 break; 417 #else 418 return EINVAL; 419 #endif 420 case KERN_SYSVIPC_SEM_INFO: 421 #ifdef SYSVSEM 422 infosize = sizeof(semsi->seminfo); 423 nds = seminfo.semmni; 424 dssize = sizeof(semsi->semids[0]); 425 break; 426 #else 427 return EINVAL; 428 #endif 429 case KERN_SYSVIPC_SHM_INFO: 430 #ifdef SYSVSHM 431 infosize = sizeof(shmsi->shminfo); 432 nds = shminfo.shmmni; 433 dssize = sizeof(shmsi->shmids[0]); 434 break; 435 #else 436 return EINVAL; 437 #endif 438 default: 439 return EINVAL; 440 } 441 /* 442 * Round infosize to 64 bit boundary if requesting more than just 443 * the info structure or getting the total data size. 444 */ 445 if (where == NULL || *sizep > infosize) 446 infosize = roundup(infosize, sizeof(quad_t)); 447 tsize = infosize + nds * dssize; 448 449 /* Return just the total size required. */ 450 if (where == NULL) { 451 *sizep = tsize; 452 return 0; 453 } 454 455 /* Not enough room for even the info struct. */ 456 if (buflen < infosize) { 457 *sizep = 0; 458 return ENOMEM; 459 } 460 sz = min(tsize, buflen); 461 bf = kmem_zalloc(sz, KM_SLEEP); 462 463 switch (*name) { 464 #ifdef SYSVMSG 465 case KERN_SYSVIPC_MSG_INFO: 466 msgsi = (struct msg_sysctl_info *)bf; 467 msgsi->msginfo = msginfo; 468 break; 469 #endif 470 #ifdef SYSVSEM 471 case KERN_SYSVIPC_SEM_INFO: 472 semsi = (struct sem_sysctl_info *)bf; 473 semsi->seminfo = seminfo; 474 break; 475 #endif 476 #ifdef SYSVSHM 477 case KERN_SYSVIPC_SHM_INFO: 478 shmsi = (struct shm_sysctl_info *)bf; 479 shmsi->shminfo = shminfo; 480 break; 481 #endif 482 } 483 buflen -= infosize; 484 485 ret = 0; 486 if (buflen > 0) { 487 /* Fill in the IPC data structures. */ 488 for (i = 0; i < nds; i++) { 489 if (buflen < dssize) { 490 ret = ENOMEM; 491 break; 492 } 493 switch (*name) { 494 #ifdef SYSVMSG 495 case KERN_SYSVIPC_MSG_INFO: 496 mutex_enter(&msgmutex); 497 SYSCTL_FILL_MSG(msqs[i].msq_u, msgsi->msgids[i]); 498 mutex_exit(&msgmutex); 499 break; 500 #endif 501 #ifdef SYSVSEM 502 case KERN_SYSVIPC_SEM_INFO: 503 SYSCTL_FILL_SEM(sema[i], semsi->semids[i]); 504 break; 505 #endif 506 #ifdef SYSVSHM 507 case KERN_SYSVIPC_SHM_INFO: 508 SYSCTL_FILL_SHM(shmsegs[i], shmsi->shmids[i]); 509 break; 510 #endif 511 } 512 buflen -= dssize; 513 } 514 } 515 *sizep -= buflen; 516 error = copyout(bf, start, *sizep); 517 /* If copyout succeeded, use return code set earlier. */ 518 if (error == 0) 519 error = ret; 520 if (bf) 521 kmem_free(bf, sz); 522 return error; 523 } 524 525 SYSCTL_SETUP(sysctl_ipc_setup, "sysctl kern.ipc subtree setup") 526 { 527 528 sysctl_createv(clog, 0, NULL, NULL, 529 CTLFLAG_PERMANENT, 530 CTLTYPE_NODE, "ipc", 531 SYSCTL_DESCR("SysV IPC options"), 532 NULL, 0, NULL, 0, 533 CTL_KERN, KERN_SYSVIPC, CTL_EOL); 534 535 sysctl_createv(clog, 0, NULL, NULL, 536 CTLFLAG_PERMANENT, 537 CTLTYPE_STRUCT, "sysvipc_info", 538 SYSCTL_DESCR("System V style IPC information"), 539 sysctl_kern_sysvipc, 0, NULL, 0, 540 CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_INFO, CTL_EOL); 541 } 542
Indexes created Wed Sep 24 15:09:51 GMT 2025