Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sysctl.c
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1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Mike Karels at Berkeley Software Design, Inc. 7 * 8 * Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD 9 * project, to make these variables more userfriendly. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)kern_sysctl.c 8.4 (Berkeley) 4/14/94 36 */ 37 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD: releng/11.1/sys/kern/kern_sysctl.c 316128 2017-03-29 08:00:13Z ngie $"); 40 41 #include "opt_capsicum.h" 42 #include "opt_compat.h" 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/fail.h> 47 #include <sys/systm.h> 48 #include <sys/capsicum.h> 49 #include <sys/kernel.h> 50 #include <sys/sysctl.h> 51 #include <sys/malloc.h> 52 #include <sys/priv.h> 53 #include <sys/proc.h> 54 #include <sys/jail.h> 55 #include <sys/lock.h> 56 #include <sys/mutex.h> 57 #include <sys/rmlock.h> 58 #include <sys/sbuf.h> 59 #include <sys/sx.h> 60 #include <sys/sysproto.h> 61 #include <sys/uio.h> 62 #ifdef KTRACE 63 #include <sys/ktrace.h> 64 #endif 65 66 #include <net/vnet.h> 67 68 #include <security/mac/mac_framework.h> 69 70 #include <vm/vm.h> 71 #include <vm/vm_extern.h> 72 73 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic"); 74 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids"); 75 static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer"); 76 77 /* 78 * The sysctllock protects the MIB tree. It also protects sysctl 79 * contexts used with dynamic sysctls. The sysctl_register_oid() and 80 * sysctl_unregister_oid() routines require the sysctllock to already 81 * be held, so the sysctl_wlock() and sysctl_wunlock() routines are 82 * provided for the few places in the kernel which need to use that 83 * API rather than using the dynamic API. Use of the dynamic API is 84 * strongly encouraged for most code. 85 * 86 * The sysctlmemlock is used to limit the amount of user memory wired for 87 * sysctl requests. This is implemented by serializing any userland 88 * sysctl requests larger than a single page via an exclusive lock. 89 */ 90 static struct rmlock sysctllock; 91 static struct sx sysctlmemlock; 92 93 #define SYSCTL_WLOCK() rm_wlock(&sysctllock) 94 #define SYSCTL_WUNLOCK() rm_wunlock(&sysctllock) 95 #define SYSCTL_RLOCK(tracker) rm_rlock(&sysctllock, (tracker)) 96 #define SYSCTL_RUNLOCK(tracker) rm_runlock(&sysctllock, (tracker)) 97 #define SYSCTL_WLOCKED() rm_wowned(&sysctllock) 98 #define SYSCTL_ASSERT_LOCKED() rm_assert(&sysctllock, RA_LOCKED) 99 #define SYSCTL_ASSERT_WLOCKED() rm_assert(&sysctllock, RA_WLOCKED) 100 #define SYSCTL_ASSERT_RLOCKED() rm_assert(&sysctllock, RA_RLOCKED) 101 #define SYSCTL_INIT() rm_init_flags(&sysctllock, "sysctl lock", \ 102 RM_SLEEPABLE) 103 #define SYSCTL_SLEEP(ch, wmesg, timo) \ 104 rm_sleep(ch, &sysctllock, 0, wmesg, timo) 105 106 static int sysctl_root(SYSCTL_HANDLER_ARGS); 107 108 /* Root list */ 109 struct sysctl_oid_list sysctl__children = SLIST_HEAD_INITIALIZER(&sysctl__children); 110 111 static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, 112 int recurse); 113 static int sysctl_old_kernel(struct sysctl_req *, const void *, size_t); 114 static int sysctl_new_kernel(struct sysctl_req *, void *, size_t); 115 116 static struct sysctl_oid * 117 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list) 118 { 119 struct sysctl_oid *oidp; 120 121 SYSCTL_ASSERT_LOCKED(); 122 SLIST_FOREACH(oidp, list, oid_link) { 123 if (strcmp(oidp->oid_name, name) == 0) { 124 return (oidp); 125 } 126 } 127 return (NULL); 128 } 129 130 /* 131 * Initialization of the MIB tree. 132 * 133 * Order by number in each list. 134 */ 135 void 136 sysctl_wlock(void) 137 { 138 139 SYSCTL_WLOCK(); 140 } 141 142 void 143 sysctl_wunlock(void) 144 { 145 146 SYSCTL_WUNLOCK(); 147 } 148 149 static int 150 sysctl_root_handler_locked(struct sysctl_oid *oid, void *arg1, intmax_t arg2, 151 struct sysctl_req *req, struct rm_priotracker *tracker) 152 { 153 int error; 154 155 if (oid->oid_kind & CTLFLAG_DYN) 156 atomic_add_int(&oid->oid_running, 1); 157 158 if (tracker != NULL) 159 SYSCTL_RUNLOCK(tracker); 160 else 161 SYSCTL_WUNLOCK(); 162 163 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 164 mtx_lock(&Giant); 165 error = oid->oid_handler(oid, arg1, arg2, req); 166 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 167 mtx_unlock(&Giant); 168 169 KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error); 170 171 if (tracker != NULL) 172 SYSCTL_RLOCK(tracker); 173 else 174 SYSCTL_WLOCK(); 175 176 if (oid->oid_kind & CTLFLAG_DYN) { 177 if (atomic_fetchadd_int(&oid->oid_running, -1) == 1 && 178 (oid->oid_kind & CTLFLAG_DYING) != 0) 179 wakeup(&oid->oid_running); 180 } 181 182 return (error); 183 } 184 185 static void 186 sysctl_load_tunable_by_oid_locked(struct sysctl_oid *oidp) 187 { 188 struct sysctl_req req; 189 struct sysctl_oid *curr; 190 char *penv = NULL; 191 char path[64]; 192 ssize_t rem = sizeof(path); 193 ssize_t len; 194 uint8_t val_8; 195 uint16_t val_16; 196 uint32_t val_32; 197 int val_int; 198 long val_long; 199 int64_t val_64; 200 quad_t val_quad; 201 int error; 202 203 path[--rem] = 0; 204 205 for (curr = oidp; curr != NULL; curr = SYSCTL_PARENT(curr)) { 206 len = strlen(curr->oid_name); 207 rem -= len; 208 if (curr != oidp) 209 rem -= 1; 210 if (rem < 0) { 211 printf("OID path exceeds %d bytes\n", (int)sizeof(path)); 212 return; 213 } 214 memcpy(path + rem, curr->oid_name, len); 215 if (curr != oidp) 216 path[rem + len] = '.'; 217 } 218 219 memset(&req, 0, sizeof(req)); 220 221 req.td = curthread; 222 req.oldfunc = sysctl_old_kernel; 223 req.newfunc = sysctl_new_kernel; 224 req.lock = REQ_UNWIRED; 225 226 switch (oidp->oid_kind & CTLTYPE) { 227 case CTLTYPE_INT: 228 if (getenv_int(path + rem, &val_int) == 0) 229 return; 230 req.newlen = sizeof(val_int); 231 req.newptr = &val_int; 232 break; 233 case CTLTYPE_UINT: 234 if (getenv_uint(path + rem, (unsigned int *)&val_int) == 0) 235 return; 236 req.newlen = sizeof(val_int); 237 req.newptr = &val_int; 238 break; 239 case CTLTYPE_LONG: 240 if (getenv_long(path + rem, &val_long) == 0) 241 return; 242 req.newlen = sizeof(val_long); 243 req.newptr = &val_long; 244 break; 245 case CTLTYPE_ULONG: 246 if (getenv_ulong(path + rem, (unsigned long *)&val_long) == 0) 247 return; 248 req.newlen = sizeof(val_long); 249 req.newptr = &val_long; 250 break; 251 case CTLTYPE_S8: 252 if (getenv_int(path + rem, &val_int) == 0) 253 return; 254 val_8 = val_int; 255 req.newlen = sizeof(val_8); 256 req.newptr = &val_8; 257 break; 258 case CTLTYPE_S16: 259 if (getenv_int(path + rem, &val_int) == 0) 260 return; 261 val_16 = val_int; 262 req.newlen = sizeof(val_16); 263 req.newptr = &val_16; 264 break; 265 case CTLTYPE_S32: 266 if (getenv_long(path + rem, &val_long) == 0) 267 return; 268 val_32 = val_long; 269 req.newlen = sizeof(val_32); 270 req.newptr = &val_32; 271 break; 272 case CTLTYPE_S64: 273 if (getenv_quad(path + rem, &val_quad) == 0) 274 return; 275 val_64 = val_quad; 276 req.newlen = sizeof(val_64); 277 req.newptr = &val_64; 278 break; 279 case CTLTYPE_U8: 280 if (getenv_uint(path + rem, (unsigned int *)&val_int) == 0) 281 return; 282 val_8 = val_int; 283 req.newlen = sizeof(val_8); 284 req.newptr = &val_8; 285 break; 286 case CTLTYPE_U16: 287 if (getenv_uint(path + rem, (unsigned int *)&val_int) == 0) 288 return; 289 val_16 = val_int; 290 req.newlen = sizeof(val_16); 291 req.newptr = &val_16; 292 break; 293 case CTLTYPE_U32: 294 if (getenv_ulong(path + rem, (unsigned long *)&val_long) == 0) 295 return; 296 val_32 = val_long; 297 req.newlen = sizeof(val_32); 298 req.newptr = &val_32; 299 break; 300 case CTLTYPE_U64: 301 /* XXX there is no getenv_uquad() */ 302 if (getenv_quad(path + rem, &val_quad) == 0) 303 return; 304 val_64 = val_quad; 305 req.newlen = sizeof(val_64); 306 req.newptr = &val_64; 307 break; 308 case CTLTYPE_STRING: 309 penv = kern_getenv(path + rem); 310 if (penv == NULL) 311 return; 312 req.newlen = strlen(penv); 313 req.newptr = penv; 314 break; 315 default: 316 return; 317 } 318 error = sysctl_root_handler_locked(oidp, oidp->oid_arg1, 319 oidp->oid_arg2, &req, NULL); 320 if (error != 0) 321 printf("Setting sysctl %s failed: %d\n", path + rem, error); 322 if (penv != NULL) 323 freeenv(penv); 324 } 325 326 void 327 sysctl_register_oid(struct sysctl_oid *oidp) 328 { 329 struct sysctl_oid_list *parent = oidp->oid_parent; 330 struct sysctl_oid *p; 331 struct sysctl_oid *q; 332 int oid_number; 333 int timeout = 2; 334 335 /* 336 * First check if another oid with the same name already 337 * exists in the parent's list. 338 */ 339 SYSCTL_ASSERT_WLOCKED(); 340 p = sysctl_find_oidname(oidp->oid_name, parent); 341 if (p != NULL) { 342 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 343 p->oid_refcnt++; 344 return; 345 } else { 346 printf("can't re-use a leaf (%s)!\n", p->oid_name); 347 return; 348 } 349 } 350 /* get current OID number */ 351 oid_number = oidp->oid_number; 352 353 #if (OID_AUTO >= 0) 354 #error "OID_AUTO is expected to be a negative value" 355 #endif 356 /* 357 * Any negative OID number qualifies as OID_AUTO. Valid OID 358 * numbers should always be positive. 359 * 360 * NOTE: DO NOT change the starting value here, change it in 361 * <sys/sysctl.h>, and make sure it is at least 256 to 362 * accommodate e.g. net.inet.raw as a static sysctl node. 363 */ 364 if (oid_number < 0) { 365 static int newoid; 366 367 /* 368 * By decrementing the next OID number we spend less 369 * time inserting the OIDs into a sorted list. 370 */ 371 if (--newoid < CTL_AUTO_START) 372 newoid = 0x7fffffff; 373 374 oid_number = newoid; 375 } 376 377 /* 378 * Insert the OID into the parent's list sorted by OID number. 379 */ 380 retry: 381 q = NULL; 382 SLIST_FOREACH(p, parent, oid_link) { 383 /* check if the current OID number is in use */ 384 if (oid_number == p->oid_number) { 385 /* get the next valid OID number */ 386 if (oid_number < CTL_AUTO_START || 387 oid_number == 0x7fffffff) { 388 /* wraparound - restart */ 389 oid_number = CTL_AUTO_START; 390 /* don't loop forever */ 391 if (!timeout--) 392 panic("sysctl: Out of OID numbers\n"); 393 goto retry; 394 } else { 395 oid_number++; 396 } 397 } else if (oid_number < p->oid_number) 398 break; 399 q = p; 400 } 401 /* check for non-auto OID number collision */ 402 if (oidp->oid_number >= 0 && oidp->oid_number < CTL_AUTO_START && 403 oid_number >= CTL_AUTO_START) { 404 printf("sysctl: OID number(%d) is already in use for '%s'\n", 405 oidp->oid_number, oidp->oid_name); 406 } 407 /* update the OID number, if any */ 408 oidp->oid_number = oid_number; 409 if (q != NULL) 410 SLIST_INSERT_AFTER(q, oidp, oid_link); 411 else 412 SLIST_INSERT_HEAD(parent, oidp, oid_link); 413 414 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE && 415 #ifdef VIMAGE 416 (oidp->oid_kind & CTLFLAG_VNET) == 0 && 417 #endif 418 (oidp->oid_kind & CTLFLAG_TUN) != 0 && 419 (oidp->oid_kind & CTLFLAG_NOFETCH) == 0) { 420 /* only fetch value once */ 421 oidp->oid_kind |= CTLFLAG_NOFETCH; 422 /* try to fetch value from kernel environment */ 423 sysctl_load_tunable_by_oid_locked(oidp); 424 } 425 } 426 427 void 428 sysctl_unregister_oid(struct sysctl_oid *oidp) 429 { 430 struct sysctl_oid *p; 431 int error; 432 433 SYSCTL_ASSERT_WLOCKED(); 434 error = ENOENT; 435 if (oidp->oid_number == OID_AUTO) { 436 error = EINVAL; 437 } else { 438 SLIST_FOREACH(p, oidp->oid_parent, oid_link) { 439 if (p == oidp) { 440 SLIST_REMOVE(oidp->oid_parent, oidp, 441 sysctl_oid, oid_link); 442 error = 0; 443 break; 444 } 445 } 446 } 447 448 /* 449 * This can happen when a module fails to register and is 450 * being unloaded afterwards. It should not be a panic() 451 * for normal use. 452 */ 453 if (error) 454 printf("%s: failed to unregister sysctl\n", __func__); 455 } 456 457 /* Initialize a new context to keep track of dynamically added sysctls. */ 458 int 459 sysctl_ctx_init(struct sysctl_ctx_list *c) 460 { 461 462 if (c == NULL) { 463 return (EINVAL); 464 } 465 466 /* 467 * No locking here, the caller is responsible for not adding 468 * new nodes to a context until after this function has 469 * returned. 470 */ 471 TAILQ_INIT(c); 472 return (0); 473 } 474 475 /* Free the context, and destroy all dynamic oids registered in this context */ 476 int 477 sysctl_ctx_free(struct sysctl_ctx_list *clist) 478 { 479 struct sysctl_ctx_entry *e, *e1; 480 int error; 481 482 error = 0; 483 /* 484 * First perform a "dry run" to check if it's ok to remove oids. 485 * XXX FIXME 486 * XXX This algorithm is a hack. But I don't know any 487 * XXX better solution for now... 488 */ 489 SYSCTL_WLOCK(); 490 TAILQ_FOREACH(e, clist, link) { 491 error = sysctl_remove_oid_locked(e->entry, 0, 0); 492 if (error) 493 break; 494 } 495 /* 496 * Restore deregistered entries, either from the end, 497 * or from the place where error occurred. 498 * e contains the entry that was not unregistered 499 */ 500 if (error) 501 e1 = TAILQ_PREV(e, sysctl_ctx_list, link); 502 else 503 e1 = TAILQ_LAST(clist, sysctl_ctx_list); 504 while (e1 != NULL) { 505 sysctl_register_oid(e1->entry); 506 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link); 507 } 508 if (error) { 509 SYSCTL_WUNLOCK(); 510 return(EBUSY); 511 } 512 /* Now really delete the entries */ 513 e = TAILQ_FIRST(clist); 514 while (e != NULL) { 515 e1 = TAILQ_NEXT(e, link); 516 error = sysctl_remove_oid_locked(e->entry, 1, 0); 517 if (error) 518 panic("sysctl_remove_oid: corrupt tree, entry: %s", 519 e->entry->oid_name); 520 free(e, M_SYSCTLOID); 521 e = e1; 522 } 523 SYSCTL_WUNLOCK(); 524 return (error); 525 } 526 527 /* Add an entry to the context */ 528 struct sysctl_ctx_entry * 529 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 530 { 531 struct sysctl_ctx_entry *e; 532 533 SYSCTL_ASSERT_WLOCKED(); 534 if (clist == NULL || oidp == NULL) 535 return(NULL); 536 e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK); 537 e->entry = oidp; 538 TAILQ_INSERT_HEAD(clist, e, link); 539 return (e); 540 } 541 542 /* Find an entry in the context */ 543 struct sysctl_ctx_entry * 544 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 545 { 546 struct sysctl_ctx_entry *e; 547 548 SYSCTL_ASSERT_WLOCKED(); 549 if (clist == NULL || oidp == NULL) 550 return(NULL); 551 TAILQ_FOREACH(e, clist, link) { 552 if(e->entry == oidp) 553 return(e); 554 } 555 return (e); 556 } 557 558 /* 559 * Delete an entry from the context. 560 * NOTE: this function doesn't free oidp! You have to remove it 561 * with sysctl_remove_oid(). 562 */ 563 int 564 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 565 { 566 struct sysctl_ctx_entry *e; 567 568 if (clist == NULL || oidp == NULL) 569 return (EINVAL); 570 SYSCTL_WLOCK(); 571 e = sysctl_ctx_entry_find(clist, oidp); 572 if (e != NULL) { 573 TAILQ_REMOVE(clist, e, link); 574 SYSCTL_WUNLOCK(); 575 free(e, M_SYSCTLOID); 576 return (0); 577 } else { 578 SYSCTL_WUNLOCK(); 579 return (ENOENT); 580 } 581 } 582 583 /* 584 * Remove dynamically created sysctl trees. 585 * oidp - top of the tree to be removed 586 * del - if 0 - just deregister, otherwise free up entries as well 587 * recurse - if != 0 traverse the subtree to be deleted 588 */ 589 int 590 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse) 591 { 592 int error; 593 594 SYSCTL_WLOCK(); 595 error = sysctl_remove_oid_locked(oidp, del, recurse); 596 SYSCTL_WUNLOCK(); 597 return (error); 598 } 599 600 int 601 sysctl_remove_name(struct sysctl_oid *parent, const char *name, 602 int del, int recurse) 603 { 604 struct sysctl_oid *p, *tmp; 605 int error; 606 607 error = ENOENT; 608 SYSCTL_WLOCK(); 609 SLIST_FOREACH_SAFE(p, SYSCTL_CHILDREN(parent), oid_link, tmp) { 610 if (strcmp(p->oid_name, name) == 0) { 611 error = sysctl_remove_oid_locked(p, del, recurse); 612 break; 613 } 614 } 615 SYSCTL_WUNLOCK(); 616 617 return (error); 618 } 619 620 621 static int 622 sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse) 623 { 624 struct sysctl_oid *p, *tmp; 625 int error; 626 627 SYSCTL_ASSERT_WLOCKED(); 628 if (oidp == NULL) 629 return(EINVAL); 630 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) { 631 printf("Warning: can't remove non-dynamic nodes (%s)!\n", 632 oidp->oid_name); 633 return (EINVAL); 634 } 635 /* 636 * WARNING: normal method to do this should be through 637 * sysctl_ctx_free(). Use recursing as the last resort 638 * method to purge your sysctl tree of leftovers... 639 * However, if some other code still references these nodes, 640 * it will panic. 641 */ 642 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 643 if (oidp->oid_refcnt == 1) { 644 SLIST_FOREACH_SAFE(p, 645 SYSCTL_CHILDREN(oidp), oid_link, tmp) { 646 if (!recurse) { 647 printf("Warning: failed attempt to " 648 "remove oid %s with child %s\n", 649 oidp->oid_name, p->oid_name); 650 return (ENOTEMPTY); 651 } 652 error = sysctl_remove_oid_locked(p, del, 653 recurse); 654 if (error) 655 return (error); 656 } 657 } 658 } 659 if (oidp->oid_refcnt > 1 ) { 660 oidp->oid_refcnt--; 661 } else { 662 if (oidp->oid_refcnt == 0) { 663 printf("Warning: bad oid_refcnt=%u (%s)!\n", 664 oidp->oid_refcnt, oidp->oid_name); 665 return (EINVAL); 666 } 667 sysctl_unregister_oid(oidp); 668 if (del) { 669 /* 670 * Wait for all threads running the handler to drain. 671 * This preserves the previous behavior when the 672 * sysctl lock was held across a handler invocation, 673 * and is necessary for module unload correctness. 674 */ 675 while (oidp->oid_running > 0) { 676 oidp->oid_kind |= CTLFLAG_DYING; 677 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0); 678 } 679 if (oidp->oid_descr) 680 free(__DECONST(char *, oidp->oid_descr), 681 M_SYSCTLOID); 682 free(__DECONST(char *, oidp->oid_name), M_SYSCTLOID); 683 free(oidp, M_SYSCTLOID); 684 } 685 } 686 return (0); 687 } 688 /* 689 * Create new sysctls at run time. 690 * clist may point to a valid context initialized with sysctl_ctx_init(). 691 */ 692 struct sysctl_oid * 693 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, 694 int number, const char *name, int kind, void *arg1, intmax_t arg2, 695 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr) 696 { 697 struct sysctl_oid *oidp; 698 699 /* You have to hook up somewhere.. */ 700 if (parent == NULL) 701 return(NULL); 702 /* Check if the node already exists, otherwise create it */ 703 SYSCTL_WLOCK(); 704 oidp = sysctl_find_oidname(name, parent); 705 if (oidp != NULL) { 706 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 707 oidp->oid_refcnt++; 708 /* Update the context */ 709 if (clist != NULL) 710 sysctl_ctx_entry_add(clist, oidp); 711 SYSCTL_WUNLOCK(); 712 return (oidp); 713 } else { 714 SYSCTL_WUNLOCK(); 715 printf("can't re-use a leaf (%s)!\n", name); 716 return (NULL); 717 } 718 } 719 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO); 720 oidp->oid_parent = parent; 721 SLIST_INIT(&oidp->oid_children); 722 oidp->oid_number = number; 723 oidp->oid_refcnt = 1; 724 oidp->oid_name = strdup(name, M_SYSCTLOID); 725 oidp->oid_handler = handler; 726 oidp->oid_kind = CTLFLAG_DYN | kind; 727 oidp->oid_arg1 = arg1; 728 oidp->oid_arg2 = arg2; 729 oidp->oid_fmt = fmt; 730 if (descr != NULL) 731 oidp->oid_descr = strdup(descr, M_SYSCTLOID); 732 /* Update the context, if used */ 733 if (clist != NULL) 734 sysctl_ctx_entry_add(clist, oidp); 735 /* Register this oid */ 736 sysctl_register_oid(oidp); 737 SYSCTL_WUNLOCK(); 738 return (oidp); 739 } 740 741 /* 742 * Rename an existing oid. 743 */ 744 void 745 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) 746 { 747 char *newname; 748 char *oldname; 749 750 newname = strdup(name, M_SYSCTLOID); 751 SYSCTL_WLOCK(); 752 oldname = __DECONST(char *, oidp->oid_name); 753 oidp->oid_name = newname; 754 SYSCTL_WUNLOCK(); 755 free(oldname, M_SYSCTLOID); 756 } 757 758 /* 759 * Reparent an existing oid. 760 */ 761 int 762 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent) 763 { 764 struct sysctl_oid *oidp; 765 766 SYSCTL_WLOCK(); 767 if (oid->oid_parent == parent) { 768 SYSCTL_WUNLOCK(); 769 return (0); 770 } 771 oidp = sysctl_find_oidname(oid->oid_name, parent); 772 if (oidp != NULL) { 773 SYSCTL_WUNLOCK(); 774 return (EEXIST); 775 } 776 sysctl_unregister_oid(oid); 777 oid->oid_parent = parent; 778 oid->oid_number = OID_AUTO; 779 sysctl_register_oid(oid); 780 SYSCTL_WUNLOCK(); 781 return (0); 782 } 783 784 /* 785 * Register the kernel's oids on startup. 786 */ 787 SET_DECLARE(sysctl_set, struct sysctl_oid); 788 789 static void 790 sysctl_register_all(void *arg) 791 { 792 struct sysctl_oid **oidp; 793 794 sx_init(&sysctlmemlock, "sysctl mem"); 795 SYSCTL_INIT(); 796 SYSCTL_WLOCK(); 797 SET_FOREACH(oidp, sysctl_set) 798 sysctl_register_oid(*oidp); 799 SYSCTL_WUNLOCK(); 800 } 801 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_FIRST, sysctl_register_all, 0); 802 803 /* 804 * "Staff-functions" 805 * 806 * These functions implement a presently undocumented interface 807 * used by the sysctl program to walk the tree, and get the type 808 * so it can print the value. 809 * This interface is under work and consideration, and should probably 810 * be killed with a big axe by the first person who can find the time. 811 * (be aware though, that the proper interface isn't as obvious as it 812 * may seem, there are various conflicting requirements. 813 * 814 * {0,0} printf the entire MIB-tree. 815 * {0,1,...} return the name of the "..." OID. 816 * {0,2,...} return the next OID. 817 * {0,3} return the OID of the name in "new" 818 * {0,4,...} return the kind & format info for the "..." OID. 819 * {0,5,...} return the description the "..." OID. 820 */ 821 822 #ifdef SYSCTL_DEBUG 823 static void 824 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 825 { 826 int k; 827 struct sysctl_oid *oidp; 828 829 SYSCTL_ASSERT_LOCKED(); 830 SLIST_FOREACH(oidp, l, oid_link) { 831 832 for (k=0; k<i; k++) 833 printf(" "); 834 835 printf("%d %s ", oidp->oid_number, oidp->oid_name); 836 837 printf("%c%c", 838 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 839 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 840 841 if (oidp->oid_handler) 842 printf(" *Handler"); 843 844 switch (oidp->oid_kind & CTLTYPE) { 845 case CTLTYPE_NODE: 846 printf(" Node\n"); 847 if (!oidp->oid_handler) { 848 sysctl_sysctl_debug_dump_node( 849 SYSCTL_CHILDREN(oidp), i + 2); 850 } 851 break; 852 case CTLTYPE_INT: printf(" Int\n"); break; 853 case CTLTYPE_UINT: printf(" u_int\n"); break; 854 case CTLTYPE_LONG: printf(" Long\n"); break; 855 case CTLTYPE_ULONG: printf(" u_long\n"); break; 856 case CTLTYPE_STRING: printf(" String\n"); break; 857 case CTLTYPE_S8: printf(" int8_t\n"); break; 858 case CTLTYPE_S16: printf(" int16_t\n"); break; 859 case CTLTYPE_S32: printf(" int32_t\n"); break; 860 case CTLTYPE_S64: printf(" int64_t\n"); break; 861 case CTLTYPE_U8: printf(" uint8_t\n"); break; 862 case CTLTYPE_U16: printf(" uint16_t\n"); break; 863 case CTLTYPE_U32: printf(" uint32_t\n"); break; 864 case CTLTYPE_U64: printf(" uint64_t\n"); break; 865 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break; 866 default: printf("\n"); 867 } 868 869 } 870 } 871 872 static int 873 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 874 { 875 struct rm_priotracker tracker; 876 int error; 877 878 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 879 if (error) 880 return (error); 881 SYSCTL_RLOCK(&tracker); 882 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 883 SYSCTL_RUNLOCK(&tracker); 884 return (ENOENT); 885 } 886 887 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE, 888 0, 0, sysctl_sysctl_debug, "-", ""); 889 #endif 890 891 static int 892 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 893 { 894 int *name = (int *) arg1; 895 u_int namelen = arg2; 896 int error = 0; 897 struct sysctl_oid *oid; 898 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 899 struct rm_priotracker tracker; 900 char buf[10]; 901 902 SYSCTL_RLOCK(&tracker); 903 while (namelen) { 904 if (!lsp) { 905 snprintf(buf,sizeof(buf),"%d",*name); 906 if (req->oldidx) 907 error = SYSCTL_OUT(req, ".", 1); 908 if (!error) 909 error = SYSCTL_OUT(req, buf, strlen(buf)); 910 if (error) 911 goto out; 912 namelen--; 913 name++; 914 continue; 915 } 916 lsp2 = NULL; 917 SLIST_FOREACH(oid, lsp, oid_link) { 918 if (oid->oid_number != *name) 919 continue; 920 921 if (req->oldidx) 922 error = SYSCTL_OUT(req, ".", 1); 923 if (!error) 924 error = SYSCTL_OUT(req, oid->oid_name, 925 strlen(oid->oid_name)); 926 if (error) 927 goto out; 928 929 namelen--; 930 name++; 931 932 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 933 break; 934 935 if (oid->oid_handler) 936 break; 937 938 lsp2 = SYSCTL_CHILDREN(oid); 939 break; 940 } 941 lsp = lsp2; 942 } 943 error = SYSCTL_OUT(req, "", 1); 944 out: 945 SYSCTL_RUNLOCK(&tracker); 946 return (error); 947 } 948 949 /* 950 * XXXRW/JA: Shouldn't return name data for nodes that we don't permit in 951 * capability mode. 952 */ 953 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, 954 sysctl_sysctl_name, ""); 955 956 static int 957 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 958 int *next, int *len, int level, struct sysctl_oid **oidpp) 959 { 960 struct sysctl_oid *oidp; 961 962 SYSCTL_ASSERT_LOCKED(); 963 *len = level; 964 SLIST_FOREACH(oidp, lsp, oid_link) { 965 *next = oidp->oid_number; 966 *oidpp = oidp; 967 968 if (oidp->oid_kind & CTLFLAG_SKIP) 969 continue; 970 971 if (!namelen) { 972 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 973 return (0); 974 if (oidp->oid_handler) 975 /* We really should call the handler here...*/ 976 return (0); 977 lsp = SYSCTL_CHILDREN(oidp); 978 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 979 len, level+1, oidpp)) 980 return (0); 981 goto emptynode; 982 } 983 984 if (oidp->oid_number < *name) 985 continue; 986 987 if (oidp->oid_number > *name) { 988 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 989 return (0); 990 if (oidp->oid_handler) 991 return (0); 992 lsp = SYSCTL_CHILDREN(oidp); 993 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 994 next+1, len, level+1, oidpp)) 995 return (0); 996 goto next; 997 } 998 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 999 continue; 1000 1001 if (oidp->oid_handler) 1002 continue; 1003 1004 lsp = SYSCTL_CHILDREN(oidp); 1005 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 1006 len, level+1, oidpp)) 1007 return (0); 1008 next: 1009 namelen = 1; 1010 emptynode: 1011 *len = level; 1012 } 1013 return (1); 1014 } 1015 1016 static int 1017 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 1018 { 1019 int *name = (int *) arg1; 1020 u_int namelen = arg2; 1021 int i, j, error; 1022 struct sysctl_oid *oid; 1023 struct sysctl_oid_list *lsp = &sysctl__children; 1024 struct rm_priotracker tracker; 1025 int newoid[CTL_MAXNAME]; 1026 1027 SYSCTL_RLOCK(&tracker); 1028 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 1029 SYSCTL_RUNLOCK(&tracker); 1030 if (i) 1031 return (ENOENT); 1032 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 1033 return (error); 1034 } 1035 1036 /* 1037 * XXXRW/JA: Shouldn't return next data for nodes that we don't permit in 1038 * capability mode. 1039 */ 1040 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, 1041 sysctl_sysctl_next, ""); 1042 1043 static int 1044 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) 1045 { 1046 struct sysctl_oid *oidp; 1047 struct sysctl_oid_list *lsp = &sysctl__children; 1048 char *p; 1049 1050 SYSCTL_ASSERT_LOCKED(); 1051 1052 for (*len = 0; *len < CTL_MAXNAME;) { 1053 p = strsep(&name, "."); 1054 1055 oidp = SLIST_FIRST(lsp); 1056 for (;; oidp = SLIST_NEXT(oidp, oid_link)) { 1057 if (oidp == NULL) 1058 return (ENOENT); 1059 if (strcmp(p, oidp->oid_name) == 0) 1060 break; 1061 } 1062 *oid++ = oidp->oid_number; 1063 (*len)++; 1064 1065 if (name == NULL || *name == '\0') { 1066 if (oidpp) 1067 *oidpp = oidp; 1068 return (0); 1069 } 1070 1071 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 1072 break; 1073 1074 if (oidp->oid_handler) 1075 break; 1076 1077 lsp = SYSCTL_CHILDREN(oidp); 1078 } 1079 return (ENOENT); 1080 } 1081 1082 static int 1083 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 1084 { 1085 char *p; 1086 int error, oid[CTL_MAXNAME], len = 0; 1087 struct sysctl_oid *op = NULL; 1088 struct rm_priotracker tracker; 1089 1090 if (!req->newlen) 1091 return (ENOENT); 1092 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 1093 return (ENAMETOOLONG); 1094 1095 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK); 1096 1097 error = SYSCTL_IN(req, p, req->newlen); 1098 if (error) { 1099 free(p, M_SYSCTL); 1100 return (error); 1101 } 1102 1103 p [req->newlen] = '\0'; 1104 1105 SYSCTL_RLOCK(&tracker); 1106 error = name2oid(p, oid, &len, &op); 1107 SYSCTL_RUNLOCK(&tracker); 1108 1109 free(p, M_SYSCTL); 1110 1111 if (error) 1112 return (error); 1113 1114 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 1115 return (error); 1116 } 1117 1118 /* 1119 * XXXRW/JA: Shouldn't return name2oid data for nodes that we don't permit in 1120 * capability mode. 1121 */ 1122 SYSCTL_PROC(_sysctl, 3, name2oid, 1123 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE 1124 | CTLFLAG_CAPRW, 0, 0, sysctl_sysctl_name2oid, "I", ""); 1125 1126 static int 1127 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 1128 { 1129 struct sysctl_oid *oid; 1130 struct rm_priotracker tracker; 1131 int error; 1132 1133 SYSCTL_RLOCK(&tracker); 1134 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 1135 if (error) 1136 goto out; 1137 1138 if (oid->oid_fmt == NULL) { 1139 error = ENOENT; 1140 goto out; 1141 } 1142 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 1143 if (error) 1144 goto out; 1145 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 1146 out: 1147 SYSCTL_RUNLOCK(&tracker); 1148 return (error); 1149 } 1150 1151 1152 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD, 1153 sysctl_sysctl_oidfmt, ""); 1154 1155 static int 1156 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 1157 { 1158 struct sysctl_oid *oid; 1159 struct rm_priotracker tracker; 1160 int error; 1161 1162 SYSCTL_RLOCK(&tracker); 1163 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 1164 if (error) 1165 goto out; 1166 1167 if (oid->oid_descr == NULL) { 1168 error = ENOENT; 1169 goto out; 1170 } 1171 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 1172 out: 1173 SYSCTL_RUNLOCK(&tracker); 1174 return (error); 1175 } 1176 1177 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD, 1178 sysctl_sysctl_oiddescr, ""); 1179 1180 /* 1181 * Default "handler" functions. 1182 */ 1183 1184 /* 1185 * Handle a bool. 1186 * Two cases: 1187 * a variable: point arg1 at it. 1188 * a constant: pass it in arg2. 1189 */ 1190 1191 int 1192 sysctl_handle_bool(SYSCTL_HANDLER_ARGS) 1193 { 1194 uint8_t temp; 1195 int error; 1196 1197 /* 1198 * Attempt to get a coherent snapshot by making a copy of the data. 1199 */ 1200 if (arg1) 1201 temp = *(bool *)arg1 ? 1 : 0; 1202 else 1203 temp = arg2 ? 1 : 0; 1204 1205 error = SYSCTL_OUT(req, &temp, sizeof(temp)); 1206 if (error || !req->newptr) 1207 return (error); 1208 1209 if (!arg1) 1210 error = EPERM; 1211 else { 1212 error = SYSCTL_IN(req, &temp, sizeof(temp)); 1213 if (!error) 1214 *(bool *)arg1 = temp ? 1 : 0; 1215 } 1216 return (error); 1217 } 1218 1219 /* 1220 * Handle an int8_t, signed or unsigned. 1221 * Two cases: 1222 * a variable: point arg1 at it. 1223 * a constant: pass it in arg2. 1224 */ 1225 1226 int 1227 sysctl_handle_8(SYSCTL_HANDLER_ARGS) 1228 { 1229 int8_t tmpout; 1230 int error = 0; 1231 1232 /* 1233 * Attempt to get a coherent snapshot by making a copy of the data. 1234 */ 1235 if (arg1) 1236 tmpout = *(int8_t *)arg1; 1237 else 1238 tmpout = arg2; 1239 error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout)); 1240 1241 if (error || !req->newptr) 1242 return (error); 1243 1244 if (!arg1) 1245 error = EPERM; 1246 else 1247 error = SYSCTL_IN(req, arg1, sizeof(tmpout)); 1248 return (error); 1249 } 1250 1251 /* 1252 * Handle an int16_t, signed or unsigned. 1253 * Two cases: 1254 * a variable: point arg1 at it. 1255 * a constant: pass it in arg2. 1256 */ 1257 1258 int 1259 sysctl_handle_16(SYSCTL_HANDLER_ARGS) 1260 { 1261 int16_t tmpout; 1262 int error = 0; 1263 1264 /* 1265 * Attempt to get a coherent snapshot by making a copy of the data. 1266 */ 1267 if (arg1) 1268 tmpout = *(int16_t *)arg1; 1269 else 1270 tmpout = arg2; 1271 error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout)); 1272 1273 if (error || !req->newptr) 1274 return (error); 1275 1276 if (!arg1) 1277 error = EPERM; 1278 else 1279 error = SYSCTL_IN(req, arg1, sizeof(tmpout)); 1280 return (error); 1281 } 1282 1283 /* 1284 * Handle an int32_t, signed or unsigned. 1285 * Two cases: 1286 * a variable: point arg1 at it. 1287 * a constant: pass it in arg2. 1288 */ 1289 1290 int 1291 sysctl_handle_32(SYSCTL_HANDLER_ARGS) 1292 { 1293 int32_t tmpout; 1294 int error = 0; 1295 1296 /* 1297 * Attempt to get a coherent snapshot by making a copy of the data. 1298 */ 1299 if (arg1) 1300 tmpout = *(int32_t *)arg1; 1301 else 1302 tmpout = arg2; 1303 error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout)); 1304 1305 if (error || !req->newptr) 1306 return (error); 1307 1308 if (!arg1) 1309 error = EPERM; 1310 else 1311 error = SYSCTL_IN(req, arg1, sizeof(tmpout)); 1312 return (error); 1313 } 1314 1315 /* 1316 * Handle an int, signed or unsigned. 1317 * Two cases: 1318 * a variable: point arg1 at it. 1319 * a constant: pass it in arg2. 1320 */ 1321 1322 int 1323 sysctl_handle_int(SYSCTL_HANDLER_ARGS) 1324 { 1325 int tmpout, error = 0; 1326 1327 /* 1328 * Attempt to get a coherent snapshot by making a copy of the data. 1329 */ 1330 if (arg1) 1331 tmpout = *(int *)arg1; 1332 else 1333 tmpout = arg2; 1334 error = SYSCTL_OUT(req, &tmpout, sizeof(int)); 1335 1336 if (error || !req->newptr) 1337 return (error); 1338 1339 if (!arg1) 1340 error = EPERM; 1341 else 1342 error = SYSCTL_IN(req, arg1, sizeof(int)); 1343 return (error); 1344 } 1345 1346 /* 1347 * Based on on sysctl_handle_int() convert milliseconds into ticks. 1348 * Note: this is used by TCP. 1349 */ 1350 1351 int 1352 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) 1353 { 1354 int error, s, tt; 1355 1356 tt = *(int *)arg1; 1357 s = (int)((int64_t)tt * 1000 / hz); 1358 1359 error = sysctl_handle_int(oidp, &s, 0, req); 1360 if (error || !req->newptr) 1361 return (error); 1362 1363 tt = (int)((int64_t)s * hz / 1000); 1364 if (tt < 1) 1365 return (EINVAL); 1366 1367 *(int *)arg1 = tt; 1368 return (0); 1369 } 1370 1371 1372 /* 1373 * Handle a long, signed or unsigned. 1374 * Two cases: 1375 * a variable: point arg1 at it. 1376 * a constant: pass it in arg2. 1377 */ 1378 1379 int 1380 sysctl_handle_long(SYSCTL_HANDLER_ARGS) 1381 { 1382 int error = 0; 1383 long tmplong; 1384 #ifdef SCTL_MASK32 1385 int tmpint; 1386 #endif 1387 1388 /* 1389 * Attempt to get a coherent snapshot by making a copy of the data. 1390 */ 1391 if (arg1) 1392 tmplong = *(long *)arg1; 1393 else 1394 tmplong = arg2; 1395 #ifdef SCTL_MASK32 1396 if (req->flags & SCTL_MASK32) { 1397 tmpint = tmplong; 1398 error = SYSCTL_OUT(req, &tmpint, sizeof(int)); 1399 } else 1400 #endif 1401 error = SYSCTL_OUT(req, &tmplong, sizeof(long)); 1402 1403 if (error || !req->newptr) 1404 return (error); 1405 1406 if (!arg1) 1407 error = EPERM; 1408 #ifdef SCTL_MASK32 1409 else if (req->flags & SCTL_MASK32) { 1410 error = SYSCTL_IN(req, &tmpint, sizeof(int)); 1411 *(long *)arg1 = (long)tmpint; 1412 } 1413 #endif 1414 else 1415 error = SYSCTL_IN(req, arg1, sizeof(long)); 1416 return (error); 1417 } 1418 1419 /* 1420 * Handle a 64 bit int, signed or unsigned. 1421 * Two cases: 1422 * a variable: point arg1 at it. 1423 * a constant: pass it in arg2. 1424 */ 1425 int 1426 sysctl_handle_64(SYSCTL_HANDLER_ARGS) 1427 { 1428 int error = 0; 1429 uint64_t tmpout; 1430 1431 /* 1432 * Attempt to get a coherent snapshot by making a copy of the data. 1433 */ 1434 if (arg1) 1435 tmpout = *(uint64_t *)arg1; 1436 else 1437 tmpout = arg2; 1438 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t)); 1439 1440 if (error || !req->newptr) 1441 return (error); 1442 1443 if (!arg1) 1444 error = EPERM; 1445 else 1446 error = SYSCTL_IN(req, arg1, sizeof(uint64_t)); 1447 return (error); 1448 } 1449 1450 /* 1451 * Handle our generic '\0' terminated 'C' string. 1452 * Two cases: 1453 * a variable string: point arg1 at it, arg2 is max length. 1454 * a constant string: point arg1 at it, arg2 is zero. 1455 */ 1456 1457 int 1458 sysctl_handle_string(SYSCTL_HANDLER_ARGS) 1459 { 1460 size_t outlen; 1461 int error = 0, ro_string = 0; 1462 1463 /* 1464 * A zero-length buffer indicates a fixed size read-only 1465 * string: 1466 */ 1467 if (arg2 == 0) { 1468 arg2 = strlen((char *)arg1) + 1; 1469 ro_string = 1; 1470 } 1471 1472 if (req->oldptr != NULL) { 1473 char *tmparg; 1474 1475 if (ro_string) { 1476 tmparg = arg1; 1477 } else { 1478 /* try to make a coherent snapshot of the string */ 1479 tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK); 1480 memcpy(tmparg, arg1, arg2); 1481 } 1482 1483 outlen = strnlen(tmparg, arg2 - 1) + 1; 1484 error = SYSCTL_OUT(req, tmparg, outlen); 1485 1486 if (!ro_string) 1487 free(tmparg, M_SYSCTLTMP); 1488 } else { 1489 outlen = strnlen((char *)arg1, arg2 - 1) + 1; 1490 error = SYSCTL_OUT(req, NULL, outlen); 1491 } 1492 if (error || !req->newptr) 1493 return (error); 1494 1495 if ((req->newlen - req->newidx) >= arg2) { 1496 error = EINVAL; 1497 } else { 1498 arg2 = (req->newlen - req->newidx); 1499 error = SYSCTL_IN(req, arg1, arg2); 1500 ((char *)arg1)[arg2] = '\0'; 1501 } 1502 return (error); 1503 } 1504 1505 /* 1506 * Handle any kind of opaque data. 1507 * arg1 points to it, arg2 is the size. 1508 */ 1509 1510 int 1511 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 1512 { 1513 int error, tries; 1514 u_int generation; 1515 struct sysctl_req req2; 1516 1517 /* 1518 * Attempt to get a coherent snapshot, by using the thread 1519 * pre-emption counter updated from within mi_switch() to 1520 * determine if we were pre-empted during a bcopy() or 1521 * copyout(). Make 3 attempts at doing this before giving up. 1522 * If we encounter an error, stop immediately. 1523 */ 1524 tries = 0; 1525 req2 = *req; 1526 retry: 1527 generation = curthread->td_generation; 1528 error = SYSCTL_OUT(req, arg1, arg2); 1529 if (error) 1530 return (error); 1531 tries++; 1532 if (generation != curthread->td_generation && tries < 3) { 1533 *req = req2; 1534 goto retry; 1535 } 1536 1537 error = SYSCTL_IN(req, arg1, arg2); 1538 1539 return (error); 1540 } 1541 1542 /* 1543 * Transfer functions to/from kernel space. 1544 * XXX: rather untested at this point 1545 */ 1546 static int 1547 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 1548 { 1549 size_t i = 0; 1550 1551 if (req->oldptr) { 1552 i = l; 1553 if (req->oldlen <= req->oldidx) 1554 i = 0; 1555 else 1556 if (i > req->oldlen - req->oldidx) 1557 i = req->oldlen - req->oldidx; 1558 if (i > 0) 1559 bcopy(p, (char *)req->oldptr + req->oldidx, i); 1560 } 1561 req->oldidx += l; 1562 if (req->oldptr && i != l) 1563 return (ENOMEM); 1564 return (0); 1565 } 1566 1567 static int 1568 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 1569 { 1570 if (!req->newptr) 1571 return (0); 1572 if (req->newlen - req->newidx < l) 1573 return (EINVAL); 1574 bcopy((char *)req->newptr + req->newidx, p, l); 1575 req->newidx += l; 1576 return (0); 1577 } 1578 1579 int 1580 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1581 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags) 1582 { 1583 int error = 0; 1584 struct sysctl_req req; 1585 1586 bzero(&req, sizeof req); 1587 1588 req.td = td; 1589 req.flags = flags; 1590 1591 if (oldlenp) { 1592 req.oldlen = *oldlenp; 1593 } 1594 req.validlen = req.oldlen; 1595 1596 if (old) { 1597 req.oldptr= old; 1598 } 1599 1600 if (new != NULL) { 1601 req.newlen = newlen; 1602 req.newptr = new; 1603 } 1604 1605 req.oldfunc = sysctl_old_kernel; 1606 req.newfunc = sysctl_new_kernel; 1607 req.lock = REQ_UNWIRED; 1608 1609 error = sysctl_root(0, name, namelen, &req); 1610 1611 if (req.lock == REQ_WIRED && req.validlen > 0) 1612 vsunlock(req.oldptr, req.validlen); 1613 1614 if (error && error != ENOMEM) 1615 return (error); 1616 1617 if (retval) { 1618 if (req.oldptr && req.oldidx > req.validlen) 1619 *retval = req.validlen; 1620 else 1621 *retval = req.oldidx; 1622 } 1623 return (error); 1624 } 1625 1626 int 1627 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp, 1628 void *new, size_t newlen, size_t *retval, int flags) 1629 { 1630 int oid[CTL_MAXNAME]; 1631 size_t oidlen, plen; 1632 int error; 1633 1634 oid[0] = 0; /* sysctl internal magic */ 1635 oid[1] = 3; /* name2oid */ 1636 oidlen = sizeof(oid); 1637 1638 error = kernel_sysctl(td, oid, 2, oid, &oidlen, 1639 (void *)name, strlen(name), &plen, flags); 1640 if (error) 1641 return (error); 1642 1643 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp, 1644 new, newlen, retval, flags); 1645 return (error); 1646 } 1647 1648 /* 1649 * Transfer function to/from user space. 1650 */ 1651 static int 1652 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1653 { 1654 size_t i, len, origidx; 1655 int error; 1656 1657 origidx = req->oldidx; 1658 req->oldidx += l; 1659 if (req->oldptr == NULL) 1660 return (0); 1661 /* 1662 * If we have not wired the user supplied buffer and we are currently 1663 * holding locks, drop a witness warning, as it's possible that 1664 * write operations to the user page can sleep. 1665 */ 1666 if (req->lock != REQ_WIRED) 1667 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1668 "sysctl_old_user()"); 1669 i = l; 1670 len = req->validlen; 1671 if (len <= origidx) 1672 i = 0; 1673 else { 1674 if (i > len - origidx) 1675 i = len - origidx; 1676 if (req->lock == REQ_WIRED) { 1677 error = copyout_nofault(p, (char *)req->oldptr + 1678 origidx, i); 1679 } else 1680 error = copyout(p, (char *)req->oldptr + origidx, i); 1681 if (error != 0) 1682 return (error); 1683 } 1684 if (i < l) 1685 return (ENOMEM); 1686 return (0); 1687 } 1688 1689 static int 1690 sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1691 { 1692 int error; 1693 1694 if (!req->newptr) 1695 return (0); 1696 if (req->newlen - req->newidx < l) 1697 return (EINVAL); 1698 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1699 "sysctl_new_user()"); 1700 error = copyin((char *)req->newptr + req->newidx, p, l); 1701 req->newidx += l; 1702 return (error); 1703 } 1704 1705 /* 1706 * Wire the user space destination buffer. If set to a value greater than 1707 * zero, the len parameter limits the maximum amount of wired memory. 1708 */ 1709 int 1710 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len) 1711 { 1712 int ret; 1713 size_t wiredlen; 1714 1715 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen; 1716 ret = 0; 1717 if (req->lock != REQ_WIRED && req->oldptr && 1718 req->oldfunc == sysctl_old_user) { 1719 if (wiredlen != 0) { 1720 ret = vslock(req->oldptr, wiredlen); 1721 if (ret != 0) { 1722 if (ret != ENOMEM) 1723 return (ret); 1724 wiredlen = 0; 1725 } 1726 } 1727 req->lock = REQ_WIRED; 1728 req->validlen = wiredlen; 1729 } 1730 return (0); 1731 } 1732 1733 int 1734 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1735 int *nindx, struct sysctl_req *req) 1736 { 1737 struct sysctl_oid_list *lsp; 1738 struct sysctl_oid *oid; 1739 int indx; 1740 1741 SYSCTL_ASSERT_LOCKED(); 1742 lsp = &sysctl__children; 1743 indx = 0; 1744 while (indx < CTL_MAXNAME) { 1745 SLIST_FOREACH(oid, lsp, oid_link) { 1746 if (oid->oid_number == name[indx]) 1747 break; 1748 } 1749 if (oid == NULL) 1750 return (ENOENT); 1751 1752 indx++; 1753 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1754 if (oid->oid_handler != NULL || indx == namelen) { 1755 *noid = oid; 1756 if (nindx != NULL) 1757 *nindx = indx; 1758 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1759 ("%s found DYING node %p", __func__, oid)); 1760 return (0); 1761 } 1762 lsp = SYSCTL_CHILDREN(oid); 1763 } else if (indx == namelen) { 1764 *noid = oid; 1765 if (nindx != NULL) 1766 *nindx = indx; 1767 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1768 ("%s found DYING node %p", __func__, oid)); 1769 return (0); 1770 } else { 1771 return (ENOTDIR); 1772 } 1773 } 1774 return (ENOENT); 1775 } 1776 1777 /* 1778 * Traverse our tree, and find the right node, execute whatever it points 1779 * to, and return the resulting error code. 1780 */ 1781 1782 static int 1783 sysctl_root(SYSCTL_HANDLER_ARGS) 1784 { 1785 struct sysctl_oid *oid; 1786 struct rm_priotracker tracker; 1787 int error, indx, lvl; 1788 1789 SYSCTL_RLOCK(&tracker); 1790 1791 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1792 if (error) 1793 goto out; 1794 1795 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1796 /* 1797 * You can't call a sysctl when it's a node, but has 1798 * no handler. Inform the user that it's a node. 1799 * The indx may or may not be the same as namelen. 1800 */ 1801 if (oid->oid_handler == NULL) { 1802 error = EISDIR; 1803 goto out; 1804 } 1805 } 1806 1807 /* Is this sysctl writable? */ 1808 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) { 1809 error = EPERM; 1810 goto out; 1811 } 1812 1813 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL")); 1814 1815 #ifdef CAPABILITY_MODE 1816 /* 1817 * If the process is in capability mode, then don't permit reading or 1818 * writing unless specifically granted for the node. 1819 */ 1820 if (IN_CAPABILITY_MODE(req->td)) { 1821 if ((req->oldptr && !(oid->oid_kind & CTLFLAG_CAPRD)) || 1822 (req->newptr && !(oid->oid_kind & CTLFLAG_CAPWR))) { 1823 error = EPERM; 1824 goto out; 1825 } 1826 } 1827 #endif 1828 1829 /* Is this sysctl sensitive to securelevels? */ 1830 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) { 1831 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE; 1832 error = securelevel_gt(req->td->td_ucred, lvl); 1833 if (error) 1834 goto out; 1835 } 1836 1837 /* Is this sysctl writable by only privileged users? */ 1838 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) { 1839 int priv; 1840 1841 if (oid->oid_kind & CTLFLAG_PRISON) 1842 priv = PRIV_SYSCTL_WRITEJAIL; 1843 #ifdef VIMAGE 1844 else if ((oid->oid_kind & CTLFLAG_VNET) && 1845 prison_owns_vnet(req->td->td_ucred)) 1846 priv = PRIV_SYSCTL_WRITEJAIL; 1847 #endif 1848 else 1849 priv = PRIV_SYSCTL_WRITE; 1850 error = priv_check(req->td, priv); 1851 if (error) 1852 goto out; 1853 } 1854 1855 if (!oid->oid_handler) { 1856 error = EINVAL; 1857 goto out; 1858 } 1859 1860 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1861 arg1 = (int *)arg1 + indx; 1862 arg2 -= indx; 1863 } else { 1864 arg1 = oid->oid_arg1; 1865 arg2 = oid->oid_arg2; 1866 } 1867 #ifdef MAC 1868 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2, 1869 req); 1870 if (error != 0) 1871 goto out; 1872 #endif 1873 #ifdef VIMAGE 1874 if ((oid->oid_kind & CTLFLAG_VNET) && arg1 != NULL) 1875 arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1); 1876 #endif 1877 error = sysctl_root_handler_locked(oid, arg1, arg2, req, &tracker); 1878 1879 out: 1880 SYSCTL_RUNLOCK(&tracker); 1881 return (error); 1882 } 1883 1884 #ifndef _SYS_SYSPROTO_H_ 1885 struct sysctl_args { 1886 int *name; 1887 u_int namelen; 1888 void *old; 1889 size_t *oldlenp; 1890 void *new; 1891 size_t newlen; 1892 }; 1893 #endif 1894 int 1895 sys___sysctl(struct thread *td, struct sysctl_args *uap) 1896 { 1897 int error, i, name[CTL_MAXNAME]; 1898 size_t j; 1899 1900 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 1901 return (EINVAL); 1902 1903 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 1904 if (error) 1905 return (error); 1906 1907 error = userland_sysctl(td, name, uap->namelen, 1908 uap->old, uap->oldlenp, 0, 1909 uap->new, uap->newlen, &j, 0); 1910 if (error && error != ENOMEM) 1911 return (error); 1912 if (uap->oldlenp) { 1913 i = copyout(&j, uap->oldlenp, sizeof(j)); 1914 if (i) 1915 return (i); 1916 } 1917 return (error); 1918 } 1919 1920 /* 1921 * This is used from various compatibility syscalls too. That's why name 1922 * must be in kernel space. 1923 */ 1924 int 1925 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1926 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval, 1927 int flags) 1928 { 1929 int error = 0, memlocked; 1930 struct sysctl_req req; 1931 1932 bzero(&req, sizeof req); 1933 1934 req.td = td; 1935 req.flags = flags; 1936 1937 if (oldlenp) { 1938 if (inkernel) { 1939 req.oldlen = *oldlenp; 1940 } else { 1941 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 1942 if (error) 1943 return (error); 1944 } 1945 } 1946 req.validlen = req.oldlen; 1947 1948 if (old) { 1949 if (!useracc(old, req.oldlen, VM_PROT_WRITE)) 1950 return (EFAULT); 1951 req.oldptr= old; 1952 } 1953 1954 if (new != NULL) { 1955 if (!useracc(new, newlen, VM_PROT_READ)) 1956 return (EFAULT); 1957 req.newlen = newlen; 1958 req.newptr = new; 1959 } 1960 1961 req.oldfunc = sysctl_old_user; 1962 req.newfunc = sysctl_new_user; 1963 req.lock = REQ_UNWIRED; 1964 1965 #ifdef KTRACE 1966 if (KTRPOINT(curthread, KTR_SYSCTL)) 1967 ktrsysctl(name, namelen); 1968 #endif 1969 1970 if (req.oldptr && req.oldlen > PAGE_SIZE) { 1971 memlocked = 1; 1972 sx_xlock(&sysctlmemlock); 1973 } else 1974 memlocked = 0; 1975 CURVNET_SET(TD_TO_VNET(td)); 1976 1977 for (;;) { 1978 req.oldidx = 0; 1979 req.newidx = 0; 1980 error = sysctl_root(0, name, namelen, &req); 1981 if (error != EAGAIN) 1982 break; 1983 kern_yield(PRI_USER); 1984 } 1985 1986 CURVNET_RESTORE(); 1987 1988 if (req.lock == REQ_WIRED && req.validlen > 0) 1989 vsunlock(req.oldptr, req.validlen); 1990 if (memlocked) 1991 sx_xunlock(&sysctlmemlock); 1992 1993 if (error && error != ENOMEM) 1994 return (error); 1995 1996 if (retval) { 1997 if (req.oldptr && req.oldidx > req.validlen) 1998 *retval = req.validlen; 1999 else 2000 *retval = req.oldidx; 2001 } 2002 return (error); 2003 } 2004 2005 /* 2006 * Drain into a sysctl struct. The user buffer should be wired if a page 2007 * fault would cause issue. 2008 */ 2009 static int 2010 sbuf_sysctl_drain(void *arg, const char *data, int len) 2011 { 2012 struct sysctl_req *req = arg; 2013 int error; 2014 2015 error = SYSCTL_OUT(req, data, len); 2016 KASSERT(error >= 0, ("Got unexpected negative value %d", error)); 2017 return (error == 0 ? len : -error); 2018 } 2019 2020 struct sbuf * 2021 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length, 2022 struct sysctl_req *req) 2023 { 2024 2025 /* Supply a default buffer size if none given. */ 2026 if (buf == NULL && length == 0) 2027 length = 64; 2028 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN | SBUF_INCLUDENUL); 2029 sbuf_set_drain(s, sbuf_sysctl_drain, req); 2030 return (s); 2031 }
Cache object: 5f3eff33c4fb93c211779e5dc32c74fd
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