sysv_ipc.c revision 1.32.10.1
1 /* $NetBSD: sysv_ipc.c,v 1.32.10.1 2019/04/10 07:39:31 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 1.32.10.1 2019/04/10 07:39:31 martin Exp $"); 34 35 #ifdef _KERNEL_OPT 36 #include "opt_sysv.h" 37 #include "opt_sysvparam.h" 38 #include "opt_compat_netbsd.h" 39 #endif 40 41 #include <sys/syscall.h> 42 #include <sys/syscallargs.h> 43 #include <sys/syscallvar.h> 44 #include <sys/param.h> 45 #include <sys/kernel.h> 46 #include <sys/proc.h> 47 #include <sys/ipc.h> 48 #ifdef SYSVMSG 49 #include <sys/msg.h> 50 #endif 51 #ifdef SYSVSEM 52 #include <sys/sem.h> 53 #endif 54 #ifdef SYSVSHM 55 #include <sys/shm.h> 56 #endif 57 #include <sys/systm.h> 58 #include <sys/kmem.h> 59 #include <sys/module.h> 60 #include <sys/mount.h> 61 #include <sys/vnode.h> 62 #include <sys/stat.h> 63 #include <sys/sysctl.h> 64 #include <sys/kauth.h> 65 66 /* 67 * Values in support of System V compatible shared memory. XXX 68 * (originally located in sys/conf/param.c) 69 */ 70 #ifdef SYSVSHM 71 #if !defined(SHMMAX) && defined(SHMMAXPGS) 72 #define SHMMAX SHMMAXPGS /* shminit() performs a `*= PAGE_SIZE' */ 73 #elif !defined(SHMMAX) 74 #define SHMMAX 0 75 #endif 76 #ifndef SHMMIN 77 #define SHMMIN 1 78 #endif 79 #ifndef SHMMNI 80 #define SHMMNI 128 /* <64k, see IPCID_TO_IX in ipc.h */ 81 #endif 82 #ifndef SHMSEG 83 #define SHMSEG 128 84 #endif 85 86 struct shminfo shminfo = { 87 SHMMAX, 88 SHMMIN, 89 SHMMNI, 90 SHMSEG, 91 0 92 }; 93 #endif 94 95 /* 96 * Values in support of System V compatible semaphores. 97 */ 98 #ifdef SYSVSEM 99 struct seminfo seminfo = { 100 SEMMAP, /* # of entries in semaphore map */ 101 SEMMNI, /* # of semaphore identifiers */ 102 SEMMNS, /* # of semaphores in system */ 103 SEMMNU, /* # of undo structures in system */ 104 SEMMSL, /* max # of semaphores per id */ 105 SEMOPM, /* max # of operations per semop call */ 106 SEMUME, /* max # of undo entries per process */ 107 SEMUSZ, /* size in bytes of undo structure */ 108 SEMVMX, /* semaphore maximum value */ 109 SEMAEM /* adjust on exit max value */ 110 }; 111 #endif 112 113 /* 114 * Values in support of System V compatible messages. 115 */ 116 #ifdef SYSVMSG 117 struct msginfo msginfo = { 118 MSGMAX, /* max chars in a message */ 119 MSGMNI, /* # of message queue identifiers */ 120 MSGMNB, /* max chars in a queue */ 121 MSGTQL, /* max messages in system */ 122 MSGSSZ, /* size of a message segment */ 123 /* (must be small power of 2 greater than 4) */ 124 MSGSEG /* number of message segments */ 125 }; 126 #endif 127 128 #if defined(COMPAT_50) 129 int sysctl_kern_sysvipc50(SYSCTLFN_PROTO); 130 #endif 131 132 MODULE(MODULE_CLASS_EXEC, sysv_ipc, NULL); 133 134 SYSCTL_SETUP_PROTO(sysctl_ipc_setup); 135 136 static struct sysctllog *sysctl_sysvipc_clog = NULL; 137 138 static const struct syscall_package sysvipc_syscalls[] = { 139 #if defined(SYSVSHM) 140 { SYS___shmctl50, 0, (sy_call_t *)sys___shmctl50 }, 141 { SYS_shmat, 0, (sy_call_t *)sys_shmat }, 142 { SYS_shmdt, 0, (sy_call_t *)sys_shmdt }, 143 { SYS_shmget, 0, (sy_call_t *)sys_shmget }, 144 #if defined(COMPAT_10) && !defined(_LP64) 145 { SYS_compat_10_oshmsys, 0, (sy_call_t *)compat_10_sys_shmsys }, 146 #endif 147 #if defined(COMPAT_14) 148 { SYS_compat_14_shmctl, 0, (sy_call_t *)compat_14_sys_shmctl }, 149 #endif 150 #if defined(COMPAT_50) 151 { SYS_compat_50___shmctl13, 0, (sy_call_t *)compat_50_sys___shmctl13 }, 152 #endif 153 #endif /* SYSVSHM */ 154 155 #if defined(SYSVSEM) 156 { SYS_____semctl50, 0, (sy_call_t *)sys_____semctl50 }, 157 { SYS_semget, 0, (sy_call_t *)sys_semget }, 158 { SYS_semop, 0, (sy_call_t *)sys_semop }, 159 { SYS_semconfig, 0, (sy_call_t *)sys_semconfig }, 160 #if defined(COMPAT_10) && !defined(_LP64) 161 { SYS_compat_10_osemsys, 0, (sy_call_t *)compat_10_sys_semsys }, 162 #endif 163 #if defined(COMPAT_14) 164 { SYS_compat_14___semctl, 0, (sy_call_t *)compat_14_sys___semctl }, 165 #endif 166 #if defined(COMPAT_50) 167 { SYS_compat_50_____semctl13, 0, (sy_call_t *)compat_50_sys_____semctl13 }, 168 #endif 169 #endif /* SYSVSEM */ 170 171 #if defined(SYSVMSG) 172 { SYS___msgctl50, 0, (sy_call_t *)sys___msgctl50 }, 173 { SYS_msgget, 0, (sy_call_t *)sys_msgget }, 174 { SYS_msgsnd, 0, (sy_call_t *)sys_msgsnd }, 175 { SYS_msgrcv, 0, (sy_call_t *)sys_msgrcv }, 176 #if defined(COMPAT_10) && !defined(_LP64) 177 { SYS_compat_10_omsgsys, 0, (sy_call_t *)compat_10_sys_msgsys }, 178 #endif 179 #if defined(COMPAT_14) 180 { SYS_compat_14_msgctl, 0, (sy_call_t *)compat_14_sys_msgctl }, 181 #endif 182 #if defined(COMPAT_50) 183 { SYS_compat_50___msgctl13, 0, (sy_call_t *)compat_50_sys___msgctl13 }, 184 #endif 185 #endif /* SYSVMSG */ 186 { 0, 0, NULL } 187 }; 188 189 static int 190 sysv_ipc_modcmd(modcmd_t cmd, void *arg) 191 { 192 int error = 0; 193 194 switch (cmd) { 195 case MODULE_CMD_INIT: 196 /* Set up the kauth listener */ 197 sysvipcinit(); 198 199 #ifdef _MODULE 200 /* Set up the common sysctl tree */ 201 sysctl_ipc_setup(&sysctl_sysvipc_clog); 202 #endif 203 204 /* Link the system calls */ 205 error = syscall_establish(NULL, sysvipc_syscalls); 206 if (error) 207 sysvipcfini(); 208 209 /* 210 * Initialize each sub-component, including their 211 * sysctl data 212 */ 213 #ifdef SYSVSHM 214 shminit(&sysctl_sysvipc_clog); 215 #endif 216 #ifdef SYSVSEM 217 seminit(&sysctl_sysvipc_clog); 218 #endif 219 #ifdef SYSVMSG 220 msginit(&sysctl_sysvipc_clog); 221 #endif 222 break; 223 case MODULE_CMD_FINI: 224 /* 225 * Make sure no subcomponents are active. Each one 226 * tells us if it is busy, and if it was _not_ busy, 227 * we assume it has already done its own clean-up. 228 * So we might need to re-init any components that 229 * are successfully fini'd if we find one that is 230 * still busy. 231 */ 232 #ifdef SYSVSHM 233 if (shmfini()) { 234 return EBUSY; 235 } 236 #endif 237 #ifdef SYSVSEM 238 if (semfini()) { 239 #ifdef SYSVSHM 240 shminit(NULL); 241 #endif 242 return EBUSY; 243 } 244 #endif 245 #ifdef SYSVMSG 246 if (msgfini()) { 247 #ifdef SYSVSEM 248 seminit(NULL); 249 #endif 250 #ifdef SYSVSHM 251 shminit(NULL); 252 #endif 253 return EBUSY; 254 } 255 #endif 256 257 /* Unlink the system calls. */ 258 error = syscall_disestablish(NULL, sysvipc_syscalls); 259 if (error) 260 return error; 261 262 #ifdef _MODULE 263 /* Remove the sysctl sub-trees */ 264 sysctl_teardown(&sysctl_sysvipc_clog); 265 #endif 266 267 /* Remove the kauth listener */ 268 sysvipcfini(); 269 break; 270 default: 271 return ENOTTY; 272 } 273 return error; 274 } 275 276 static kauth_listener_t sysvipc_listener = NULL; 277 278 static int 279 sysvipc_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 280 void *arg0, void *arg1, void *arg2, void *arg3) 281 { 282 mode_t mask; 283 int ismember = 0; 284 struct ipc_perm *perm; 285 int mode; 286 enum kauth_system_req req; 287 288 req = (enum kauth_system_req)arg0; 289 290 if (!(action == KAUTH_SYSTEM_SYSVIPC && 291 req == KAUTH_REQ_SYSTEM_SYSVIPC_BYPASS)) 292 return KAUTH_RESULT_DEFER; 293 294 perm = arg1; 295 mode = (int)(uintptr_t)arg2; 296 297 if (mode == IPC_M) { 298 if (kauth_cred_geteuid(cred) == perm->uid || 299 kauth_cred_geteuid(cred) == perm->cuid) 300 return (KAUTH_RESULT_ALLOW); 301 return (KAUTH_RESULT_DEFER); /* EPERM */ 302 } 303 304 mask = 0; 305 306 if (kauth_cred_geteuid(cred) == perm->uid || 307 kauth_cred_geteuid(cred) == perm->cuid) { 308 if (mode & IPC_R) 309 mask |= S_IRUSR; 310 if (mode & IPC_W) 311 mask |= S_IWUSR; 312 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 313 } 314 315 if (kauth_cred_getegid(cred) == perm->gid || 316 (kauth_cred_ismember_gid(cred, perm->gid, &ismember) == 0 && ismember) || 317 kauth_cred_getegid(cred) == perm->cgid || 318 (kauth_cred_ismember_gid(cred, perm->cgid, &ismember) == 0 && ismember)) { 319 if (mode & IPC_R) 320 mask |= S_IRGRP; 321 if (mode & IPC_W) 322 mask |= S_IWGRP; 323 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 324 } 325 326 if (mode & IPC_R) 327 mask |= S_IROTH; 328 if (mode & IPC_W) 329 mask |= S_IWOTH; 330 return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); 331 } 332 333 /* 334 * Check for ipc permission 335 */ 336 337 int 338 ipcperm(kauth_cred_t cred, struct ipc_perm *perm, int mode) 339 { 340 int error; 341 342 error = kauth_authorize_system(cred, KAUTH_SYSTEM_SYSVIPC, 343 KAUTH_REQ_SYSTEM_SYSVIPC_BYPASS, perm, KAUTH_ARG(mode), NULL); 344 if (error == 0) 345 return (0); 346 347 /* Adjust EPERM and EACCES errors until there's a better way to do this. */ 348 if (mode != IPC_M) 349 error = EACCES; 350 351 return error; 352 } 353 354 void 355 sysvipcfini(void) 356 { 357 358 KASSERT(sysvipc_listener != NULL); 359 kauth_unlisten_scope(sysvipc_listener); 360 sysvipc_listener = NULL; 361 } 362 363 void 364 sysvipcinit(void) 365 { 366 367 KASSERT(sysvipc_listener == NULL); 368 369 sysvipc_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM, 370 sysvipc_listener_cb, NULL); 371 } 372 373 static int 374 sysctl_kern_sysvipc(SYSCTLFN_ARGS) 375 { 376 void *where = oldp; 377 size_t sz, *sizep = oldlenp; 378 #ifdef SYSVMSG 379 struct msg_sysctl_info *msgsi = NULL; 380 #endif 381 #ifdef SYSVSEM 382 struct sem_sysctl_info *semsi = NULL; 383 #endif 384 #ifdef SYSVSHM 385 struct shm_sysctl_info *shmsi = NULL; 386 #endif 387 size_t infosize, dssize, tsize, buflen; 388 void *bf = NULL; 389 char *start; 390 int32_t nds; 391 int i, error, ret; 392 393 /* 394 * If present, call the compat sysctl() code. If it handles the request 395 * completely (either success or error), return. Otherwise fallthrough 396 * to the non-compat sysctl code. 397 */ 398 399 #if defined(COMPAT_50) 400 error = sysctl_kern_sysvipc50(SYSCTLFN_CALL(rnode)); 401 if (error != EPASSTHROUGH) 402 return error; 403 #endif 404 405 if (namelen != 1) 406 return EINVAL; 407 408 start = where; 409 buflen = *sizep; 410 411 switch (*name) { 412 case KERN_SYSVIPC_MSG_INFO: 413 #ifdef SYSVMSG 414 infosize = sizeof(msgsi->msginfo); 415 nds = msginfo.msgmni; 416 dssize = sizeof(msgsi->msgids[0]); 417 break; 418 #else 419 return EINVAL; 420 #endif 421 case KERN_SYSVIPC_SEM_INFO: 422 #ifdef SYSVSEM 423 infosize = sizeof(semsi->seminfo); 424 nds = seminfo.semmni; 425 dssize = sizeof(semsi->semids[0]); 426 break; 427 #else 428 return EINVAL; 429 #endif 430 case KERN_SYSVIPC_SHM_INFO: 431 #ifdef SYSVSHM 432 infosize = sizeof(shmsi->shminfo); 433 nds = shminfo.shmmni; 434 dssize = sizeof(shmsi->shmids[0]); 435 break; 436 #else 437 return EINVAL; 438 #endif 439 default: 440 return EINVAL; 441 } 442 /* 443 * Round infosize to 64 bit boundary if requesting more than just 444 * the info structure or getting the total data size. 445 */ 446 if (where == NULL || *sizep > infosize) 447 infosize = roundup(infosize, sizeof(quad_t)); 448 tsize = infosize + nds * dssize; 449 450 /* Return just the total size required. */ 451 if (where == NULL) { 452 *sizep = tsize; 453 return 0; 454 } 455 456 /* Not enough room for even the info struct. */ 457 if (buflen < infosize) { 458 *sizep = 0; 459 return ENOMEM; 460 } 461 sz = min(tsize, buflen); 462 bf = kmem_zalloc(sz, KM_SLEEP); 463 464 switch (*name) { 465 #ifdef SYSVMSG 466 case KERN_SYSVIPC_MSG_INFO: 467 msgsi = (struct msg_sysctl_info *)bf; 468 msgsi->msginfo = msginfo; 469 break; 470 #endif 471 #ifdef SYSVSEM 472 case KERN_SYSVIPC_SEM_INFO: 473 semsi = (struct sem_sysctl_info *)bf; 474 semsi->seminfo = seminfo; 475 break; 476 #endif 477 #ifdef SYSVSHM 478 case KERN_SYSVIPC_SHM_INFO: 479 shmsi = (struct shm_sysctl_info *)bf; 480 shmsi->shminfo = shminfo; 481 break; 482 #endif 483 } 484 buflen -= infosize; 485 486 ret = 0; 487 if (buflen > 0) { 488 /* Fill in the IPC data structures. */ 489 for (i = 0; i < nds; i++) { 490 if (buflen < dssize) { 491 ret = ENOMEM; 492 break; 493 } 494 switch (*name) { 495 #ifdef SYSVMSG 496 case KERN_SYSVIPC_MSG_INFO: 497 mutex_enter(&msgmutex); 498 SYSCTL_FILL_MSG(msqs[i].msq_u, msgsi->msgids[i]); 499 mutex_exit(&msgmutex); 500 break; 501 #endif 502 #ifdef SYSVSEM 503 case KERN_SYSVIPC_SEM_INFO: 504 SYSCTL_FILL_SEM(sema[i], semsi->semids[i]); 505 break; 506 #endif 507 #ifdef SYSVSHM 508 case KERN_SYSVIPC_SHM_INFO: 509 SYSCTL_FILL_SHM(shmsegs[i], shmsi->shmids[i]); 510 break; 511 #endif 512 } 513 buflen -= dssize; 514 } 515 } 516 *sizep -= buflen; 517 error = copyout(bf, start, *sizep); 518 /* If copyout succeeded, use return code set earlier. */ 519 if (error == 0) 520 error = ret; 521 if (bf) 522 kmem_free(bf, sz); 523 return error; 524 } 525 526 SYSCTL_SETUP(sysctl_ipc_setup, "sysctl kern.ipc subtree setup") 527 { 528 529 sysctl_createv(clog, 0, NULL, NULL, 530 CTLFLAG_PERMANENT, 531 CTLTYPE_NODE, "ipc", 532 SYSCTL_DESCR("SysV IPC options"), 533 NULL, 0, NULL, 0, 534 CTL_KERN, KERN_SYSVIPC, CTL_EOL); 535 536 sysctl_createv(clog, 0, NULL, NULL, 537 CTLFLAG_PERMANENT, 538 CTLTYPE_STRUCT, "sysvipc_info", 539 SYSCTL_DESCR("System V style IPC information"), 540 sysctl_kern_sysvipc, 0, NULL, 0, 541 CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_INFO, CTL_EOL); 542 } 543
Indexes created Wed Sep 24 15:09:51 GMT 2025