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/11.0/sys/kern/kern_sysctl.c 300718 2016-05-26 08:41:55Z hselasky $"); 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("can't remove non-dynamic nodes!\n"); 632 return (EINVAL); 633 } 634 /* 635 * WARNING: normal method to do this should be through 636 * sysctl_ctx_free(). Use recursing as the last resort 637 * method to purge your sysctl tree of leftovers... 638 * However, if some other code still references these nodes, 639 * it will panic. 640 */ 641 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 642 if (oidp->oid_refcnt == 1) { 643 SLIST_FOREACH_SAFE(p, 644 SYSCTL_CHILDREN(oidp), oid_link, tmp) { 645 if (!recurse) { 646 printf("Warning: failed attempt to " 647 "remove oid %s with child %s\n", 648 oidp->oid_name, p->oid_name); 649 return (ENOTEMPTY); 650 } 651 error = sysctl_remove_oid_locked(p, del, 652 recurse); 653 if (error) 654 return (error); 655 } 656 } 657 } 658 if (oidp->oid_refcnt > 1 ) { 659 oidp->oid_refcnt--; 660 } else { 661 if (oidp->oid_refcnt == 0) { 662 printf("Warning: bad oid_refcnt=%u (%s)!\n", 663 oidp->oid_refcnt, oidp->oid_name); 664 return (EINVAL); 665 } 666 sysctl_unregister_oid(oidp); 667 if (del) { 668 /* 669 * Wait for all threads running the handler to drain. 670 * This preserves the previous behavior when the 671 * sysctl lock was held across a handler invocation, 672 * and is necessary for module unload correctness. 673 */ 674 while (oidp->oid_running > 0) { 675 oidp->oid_kind |= CTLFLAG_DYING; 676 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0); 677 } 678 if (oidp->oid_descr) 679 free(__DECONST(char *, oidp->oid_descr), 680 M_SYSCTLOID); 681 free(__DECONST(char *, oidp->oid_name), M_SYSCTLOID); 682 free(oidp, M_SYSCTLOID); 683 } 684 } 685 return (0); 686 } 687 /* 688 * Create new sysctls at run time. 689 * clist may point to a valid context initialized with sysctl_ctx_init(). 690 */ 691 struct sysctl_oid * 692 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, 693 int number, const char *name, int kind, void *arg1, intmax_t arg2, 694 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr) 695 { 696 struct sysctl_oid *oidp; 697 698 /* You have to hook up somewhere.. */ 699 if (parent == NULL) 700 return(NULL); 701 /* Check if the node already exists, otherwise create it */ 702 SYSCTL_WLOCK(); 703 oidp = sysctl_find_oidname(name, parent); 704 if (oidp != NULL) { 705 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 706 oidp->oid_refcnt++; 707 /* Update the context */ 708 if (clist != NULL) 709 sysctl_ctx_entry_add(clist, oidp); 710 SYSCTL_WUNLOCK(); 711 return (oidp); 712 } else { 713 SYSCTL_WUNLOCK(); 714 printf("can't re-use a leaf (%s)!\n", name); 715 return (NULL); 716 } 717 } 718 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO); 719 oidp->oid_parent = parent; 720 SLIST_INIT(&oidp->oid_children); 721 oidp->oid_number = number; 722 oidp->oid_refcnt = 1; 723 oidp->oid_name = strdup(name, M_SYSCTLOID); 724 oidp->oid_handler = handler; 725 oidp->oid_kind = CTLFLAG_DYN | kind; 726 oidp->oid_arg1 = arg1; 727 oidp->oid_arg2 = arg2; 728 oidp->oid_fmt = fmt; 729 if (descr != NULL) 730 oidp->oid_descr = strdup(descr, M_SYSCTLOID); 731 /* Update the context, if used */ 732 if (clist != NULL) 733 sysctl_ctx_entry_add(clist, oidp); 734 /* Register this oid */ 735 sysctl_register_oid(oidp); 736 SYSCTL_WUNLOCK(); 737 return (oidp); 738 } 739 740 /* 741 * Rename an existing oid. 742 */ 743 void 744 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) 745 { 746 char *newname; 747 char *oldname; 748 749 newname = strdup(name, M_SYSCTLOID); 750 SYSCTL_WLOCK(); 751 oldname = __DECONST(char *, oidp->oid_name); 752 oidp->oid_name = newname; 753 SYSCTL_WUNLOCK(); 754 free(oldname, M_SYSCTLOID); 755 } 756 757 /* 758 * Reparent an existing oid. 759 */ 760 int 761 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent) 762 { 763 struct sysctl_oid *oidp; 764 765 SYSCTL_WLOCK(); 766 if (oid->oid_parent == parent) { 767 SYSCTL_WUNLOCK(); 768 return (0); 769 } 770 oidp = sysctl_find_oidname(oid->oid_name, parent); 771 if (oidp != NULL) { 772 SYSCTL_WUNLOCK(); 773 return (EEXIST); 774 } 775 sysctl_unregister_oid(oid); 776 oid->oid_parent = parent; 777 oid->oid_number = OID_AUTO; 778 sysctl_register_oid(oid); 779 SYSCTL_WUNLOCK(); 780 return (0); 781 } 782 783 /* 784 * Register the kernel's oids on startup. 785 */ 786 SET_DECLARE(sysctl_set, struct sysctl_oid); 787 788 static void 789 sysctl_register_all(void *arg) 790 { 791 struct sysctl_oid **oidp; 792 793 sx_init(&sysctlmemlock, "sysctl mem"); 794 SYSCTL_INIT(); 795 SYSCTL_WLOCK(); 796 SET_FOREACH(oidp, sysctl_set) 797 sysctl_register_oid(*oidp); 798 SYSCTL_WUNLOCK(); 799 } 800 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_FIRST, sysctl_register_all, 0); 801 802 /* 803 * "Staff-functions" 804 * 805 * These functions implement a presently undocumented interface 806 * used by the sysctl program to walk the tree, and get the type 807 * so it can print the value. 808 * This interface is under work and consideration, and should probably 809 * be killed with a big axe by the first person who can find the time. 810 * (be aware though, that the proper interface isn't as obvious as it 811 * may seem, there are various conflicting requirements. 812 * 813 * {0,0} printf the entire MIB-tree. 814 * {0,1,...} return the name of the "..." OID. 815 * {0,2,...} return the next OID. 816 * {0,3} return the OID of the name in "new" 817 * {0,4,...} return the kind & format info for the "..." OID. 818 * {0,5,...} return the description the "..." OID. 819 */ 820 821 #ifdef SYSCTL_DEBUG 822 static void 823 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 824 { 825 int k; 826 struct sysctl_oid *oidp; 827 828 SYSCTL_ASSERT_LOCKED(); 829 SLIST_FOREACH(oidp, l, oid_link) { 830 831 for (k=0; k<i; k++) 832 printf(" "); 833 834 printf("%d %s ", oidp->oid_number, oidp->oid_name); 835 836 printf("%c%c", 837 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 838 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 839 840 if (oidp->oid_handler) 841 printf(" *Handler"); 842 843 switch (oidp->oid_kind & CTLTYPE) { 844 case CTLTYPE_NODE: 845 printf(" Node\n"); 846 if (!oidp->oid_handler) { 847 sysctl_sysctl_debug_dump_node( 848 SYSCTL_CHILDREN(oidp), i + 2); 849 } 850 break; 851 case CTLTYPE_INT: printf(" Int\n"); break; 852 case CTLTYPE_UINT: printf(" u_int\n"); break; 853 case CTLTYPE_LONG: printf(" Long\n"); break; 854 case CTLTYPE_ULONG: printf(" u_long\n"); break; 855 case CTLTYPE_STRING: printf(" String\n"); break; 856 case CTLTYPE_S8: printf(" int8_t\n"); break; 857 case CTLTYPE_S16: printf(" int16_t\n"); break; 858 case CTLTYPE_S32: printf(" int32_t\n"); break; 859 case CTLTYPE_S64: printf(" int64_t\n"); break; 860 case CTLTYPE_U8: printf(" uint8_t\n"); break; 861 case CTLTYPE_U16: printf(" uint16_t\n"); break; 862 case CTLTYPE_U32: printf(" uint32_t\n"); break; 863 case CTLTYPE_U64: printf(" uint64_t\n"); break; 864 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break; 865 default: printf("\n"); 866 } 867 868 } 869 } 870 871 static int 872 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 873 { 874 struct rm_priotracker tracker; 875 int error; 876 877 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 878 if (error) 879 return (error); 880 SYSCTL_RLOCK(&tracker); 881 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 882 SYSCTL_RUNLOCK(&tracker); 883 return (ENOENT); 884 } 885 886 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE, 887 0, 0, sysctl_sysctl_debug, "-", ""); 888 #endif 889 890 static int 891 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 892 { 893 int *name = (int *) arg1; 894 u_int namelen = arg2; 895 int error = 0; 896 struct sysctl_oid *oid; 897 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 898 struct rm_priotracker tracker; 899 char buf[10]; 900 901 SYSCTL_RLOCK(&tracker); 902 while (namelen) { 903 if (!lsp) { 904 snprintf(buf,sizeof(buf),"%d",*name); 905 if (req->oldidx) 906 error = SYSCTL_OUT(req, ".", 1); 907 if (!error) 908 error = SYSCTL_OUT(req, buf, strlen(buf)); 909 if (error) 910 goto out; 911 namelen--; 912 name++; 913 continue; 914 } 915 lsp2 = NULL; 916 SLIST_FOREACH(oid, lsp, oid_link) { 917 if (oid->oid_number != *name) 918 continue; 919 920 if (req->oldidx) 921 error = SYSCTL_OUT(req, ".", 1); 922 if (!error) 923 error = SYSCTL_OUT(req, oid->oid_name, 924 strlen(oid->oid_name)); 925 if (error) 926 goto out; 927 928 namelen--; 929 name++; 930 931 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 932 break; 933 934 if (oid->oid_handler) 935 break; 936 937 lsp2 = SYSCTL_CHILDREN(oid); 938 break; 939 } 940 lsp = lsp2; 941 } 942 error = SYSCTL_OUT(req, "", 1); 943 out: 944 SYSCTL_RUNLOCK(&tracker); 945 return (error); 946 } 947 948 /* 949 * XXXRW/JA: Shouldn't return name data for nodes that we don't permit in 950 * capability mode. 951 */ 952 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, 953 sysctl_sysctl_name, ""); 954 955 static int 956 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 957 int *next, int *len, int level, struct sysctl_oid **oidpp) 958 { 959 struct sysctl_oid *oidp; 960 961 SYSCTL_ASSERT_LOCKED(); 962 *len = level; 963 SLIST_FOREACH(oidp, lsp, oid_link) { 964 *next = oidp->oid_number; 965 *oidpp = oidp; 966 967 if (oidp->oid_kind & CTLFLAG_SKIP) 968 continue; 969 970 if (!namelen) { 971 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 972 return (0); 973 if (oidp->oid_handler) 974 /* We really should call the handler here...*/ 975 return (0); 976 lsp = SYSCTL_CHILDREN(oidp); 977 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 978 len, level+1, oidpp)) 979 return (0); 980 goto emptynode; 981 } 982 983 if (oidp->oid_number < *name) 984 continue; 985 986 if (oidp->oid_number > *name) { 987 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 988 return (0); 989 if (oidp->oid_handler) 990 return (0); 991 lsp = SYSCTL_CHILDREN(oidp); 992 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 993 next+1, len, level+1, oidpp)) 994 return (0); 995 goto next; 996 } 997 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 998 continue; 999 1000 if (oidp->oid_handler) 1001 continue; 1002 1003 lsp = SYSCTL_CHILDREN(oidp); 1004 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 1005 len, level+1, oidpp)) 1006 return (0); 1007 next: 1008 namelen = 1; 1009 emptynode: 1010 *len = level; 1011 } 1012 return (1); 1013 } 1014 1015 static int 1016 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 1017 { 1018 int *name = (int *) arg1; 1019 u_int namelen = arg2; 1020 int i, j, error; 1021 struct sysctl_oid *oid; 1022 struct sysctl_oid_list *lsp = &sysctl__children; 1023 struct rm_priotracker tracker; 1024 int newoid[CTL_MAXNAME]; 1025 1026 SYSCTL_RLOCK(&tracker); 1027 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 1028 SYSCTL_RUNLOCK(&tracker); 1029 if (i) 1030 return (ENOENT); 1031 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 1032 return (error); 1033 } 1034 1035 /* 1036 * XXXRW/JA: Shouldn't return next data for nodes that we don't permit in 1037 * capability mode. 1038 */ 1039 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, 1040 sysctl_sysctl_next, ""); 1041 1042 static int 1043 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) 1044 { 1045 struct sysctl_oid *oidp; 1046 struct sysctl_oid_list *lsp = &sysctl__children; 1047 char *p; 1048 1049 SYSCTL_ASSERT_LOCKED(); 1050 1051 for (*len = 0; *len < CTL_MAXNAME;) { 1052 p = strsep(&name, "."); 1053 1054 oidp = SLIST_FIRST(lsp); 1055 for (;; oidp = SLIST_NEXT(oidp, oid_link)) { 1056 if (oidp == NULL) 1057 return (ENOENT); 1058 if (strcmp(p, oidp->oid_name) == 0) 1059 break; 1060 } 1061 *oid++ = oidp->oid_number; 1062 (*len)++; 1063 1064 if (name == NULL || *name == '\0') { 1065 if (oidpp) 1066 *oidpp = oidp; 1067 return (0); 1068 } 1069 1070 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 1071 break; 1072 1073 if (oidp->oid_handler) 1074 break; 1075 1076 lsp = SYSCTL_CHILDREN(oidp); 1077 } 1078 return (ENOENT); 1079 } 1080 1081 static int 1082 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 1083 { 1084 char *p; 1085 int error, oid[CTL_MAXNAME], len = 0; 1086 struct sysctl_oid *op = NULL; 1087 struct rm_priotracker tracker; 1088 1089 if (!req->newlen) 1090 return (ENOENT); 1091 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 1092 return (ENAMETOOLONG); 1093 1094 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK); 1095 1096 error = SYSCTL_IN(req, p, req->newlen); 1097 if (error) { 1098 free(p, M_SYSCTL); 1099 return (error); 1100 } 1101 1102 p [req->newlen] = '\0'; 1103 1104 SYSCTL_RLOCK(&tracker); 1105 error = name2oid(p, oid, &len, &op); 1106 SYSCTL_RUNLOCK(&tracker); 1107 1108 free(p, M_SYSCTL); 1109 1110 if (error) 1111 return (error); 1112 1113 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 1114 return (error); 1115 } 1116 1117 /* 1118 * XXXRW/JA: Shouldn't return name2oid data for nodes that we don't permit in 1119 * capability mode. 1120 */ 1121 SYSCTL_PROC(_sysctl, 3, name2oid, 1122 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE 1123 | CTLFLAG_CAPRW, 0, 0, sysctl_sysctl_name2oid, "I", ""); 1124 1125 static int 1126 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 1127 { 1128 struct sysctl_oid *oid; 1129 struct rm_priotracker tracker; 1130 int error; 1131 1132 SYSCTL_RLOCK(&tracker); 1133 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 1134 if (error) 1135 goto out; 1136 1137 if (oid->oid_fmt == NULL) { 1138 error = ENOENT; 1139 goto out; 1140 } 1141 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 1142 if (error) 1143 goto out; 1144 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 1145 out: 1146 SYSCTL_RUNLOCK(&tracker); 1147 return (error); 1148 } 1149 1150 1151 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD, 1152 sysctl_sysctl_oidfmt, ""); 1153 1154 static int 1155 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 1156 { 1157 struct sysctl_oid *oid; 1158 struct rm_priotracker tracker; 1159 int error; 1160 1161 SYSCTL_RLOCK(&tracker); 1162 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 1163 if (error) 1164 goto out; 1165 1166 if (oid->oid_descr == NULL) { 1167 error = ENOENT; 1168 goto out; 1169 } 1170 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 1171 out: 1172 SYSCTL_RUNLOCK(&tracker); 1173 return (error); 1174 } 1175 1176 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD, 1177 sysctl_sysctl_oiddescr, ""); 1178 1179 /* 1180 * Default "handler" functions. 1181 */ 1182 1183 /* 1184 * Handle a bool. 1185 * Two cases: 1186 * a variable: point arg1 at it. 1187 * a constant: pass it in arg2. 1188 */ 1189 1190 int 1191 sysctl_handle_bool(SYSCTL_HANDLER_ARGS) 1192 { 1193 uint8_t temp; 1194 int error; 1195 1196 /* 1197 * Attempt to get a coherent snapshot by making a copy of the data. 1198 */ 1199 if (arg1) 1200 temp = *(bool *)arg1 ? 1 : 0; 1201 else 1202 temp = arg2 ? 1 : 0; 1203 1204 error = SYSCTL_OUT(req, &temp, sizeof(temp)); 1205 if (error || !req->newptr) 1206 return (error); 1207 1208 if (!arg1) 1209 error = EPERM; 1210 else { 1211 error = SYSCTL_IN(req, &temp, sizeof(temp)); 1212 if (!error) 1213 *(bool *)arg1 = temp ? 1 : 0; 1214 } 1215 return (error); 1216 } 1217 1218 /* 1219 * Handle an int8_t, signed or unsigned. 1220 * Two cases: 1221 * a variable: point arg1 at it. 1222 * a constant: pass it in arg2. 1223 */ 1224 1225 int 1226 sysctl_handle_8(SYSCTL_HANDLER_ARGS) 1227 { 1228 int8_t tmpout; 1229 int error = 0; 1230 1231 /* 1232 * Attempt to get a coherent snapshot by making a copy of the data. 1233 */ 1234 if (arg1) 1235 tmpout = *(int8_t *)arg1; 1236 else 1237 tmpout = arg2; 1238 error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout)); 1239 1240 if (error || !req->newptr) 1241 return (error); 1242 1243 if (!arg1) 1244 error = EPERM; 1245 else 1246 error = SYSCTL_IN(req, arg1, sizeof(tmpout)); 1247 return (error); 1248 } 1249 1250 /* 1251 * Handle an int16_t, signed or unsigned. 1252 * Two cases: 1253 * a variable: point arg1 at it. 1254 * a constant: pass it in arg2. 1255 */ 1256 1257 int 1258 sysctl_handle_16(SYSCTL_HANDLER_ARGS) 1259 { 1260 int16_t tmpout; 1261 int error = 0; 1262 1263 /* 1264 * Attempt to get a coherent snapshot by making a copy of the data. 1265 */ 1266 if (arg1) 1267 tmpout = *(int16_t *)arg1; 1268 else 1269 tmpout = arg2; 1270 error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout)); 1271 1272 if (error || !req->newptr) 1273 return (error); 1274 1275 if (!arg1) 1276 error = EPERM; 1277 else 1278 error = SYSCTL_IN(req, arg1, sizeof(tmpout)); 1279 return (error); 1280 } 1281 1282 /* 1283 * Handle an int32_t, signed or unsigned. 1284 * Two cases: 1285 * a variable: point arg1 at it. 1286 * a constant: pass it in arg2. 1287 */ 1288 1289 int 1290 sysctl_handle_32(SYSCTL_HANDLER_ARGS) 1291 { 1292 int32_t tmpout; 1293 int error = 0; 1294 1295 /* 1296 * Attempt to get a coherent snapshot by making a copy of the data. 1297 */ 1298 if (arg1) 1299 tmpout = *(int32_t *)arg1; 1300 else 1301 tmpout = arg2; 1302 error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout)); 1303 1304 if (error || !req->newptr) 1305 return (error); 1306 1307 if (!arg1) 1308 error = EPERM; 1309 else 1310 error = SYSCTL_IN(req, arg1, sizeof(tmpout)); 1311 return (error); 1312 } 1313 1314 /* 1315 * Handle an int, signed or unsigned. 1316 * Two cases: 1317 * a variable: point arg1 at it. 1318 * a constant: pass it in arg2. 1319 */ 1320 1321 int 1322 sysctl_handle_int(SYSCTL_HANDLER_ARGS) 1323 { 1324 int tmpout, error = 0; 1325 1326 /* 1327 * Attempt to get a coherent snapshot by making a copy of the data. 1328 */ 1329 if (arg1) 1330 tmpout = *(int *)arg1; 1331 else 1332 tmpout = arg2; 1333 error = SYSCTL_OUT(req, &tmpout, sizeof(int)); 1334 1335 if (error || !req->newptr) 1336 return (error); 1337 1338 if (!arg1) 1339 error = EPERM; 1340 else 1341 error = SYSCTL_IN(req, arg1, sizeof(int)); 1342 return (error); 1343 } 1344 1345 /* 1346 * Based on on sysctl_handle_int() convert milliseconds into ticks. 1347 * Note: this is used by TCP. 1348 */ 1349 1350 int 1351 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) 1352 { 1353 int error, s, tt; 1354 1355 tt = *(int *)arg1; 1356 s = (int)((int64_t)tt * 1000 / hz); 1357 1358 error = sysctl_handle_int(oidp, &s, 0, req); 1359 if (error || !req->newptr) 1360 return (error); 1361 1362 tt = (int)((int64_t)s * hz / 1000); 1363 if (tt < 1) 1364 return (EINVAL); 1365 1366 *(int *)arg1 = tt; 1367 return (0); 1368 } 1369 1370 1371 /* 1372 * Handle a long, signed or unsigned. 1373 * Two cases: 1374 * a variable: point arg1 at it. 1375 * a constant: pass it in arg2. 1376 */ 1377 1378 int 1379 sysctl_handle_long(SYSCTL_HANDLER_ARGS) 1380 { 1381 int error = 0; 1382 long tmplong; 1383 #ifdef SCTL_MASK32 1384 int tmpint; 1385 #endif 1386 1387 /* 1388 * Attempt to get a coherent snapshot by making a copy of the data. 1389 */ 1390 if (arg1) 1391 tmplong = *(long *)arg1; 1392 else 1393 tmplong = arg2; 1394 #ifdef SCTL_MASK32 1395 if (req->flags & SCTL_MASK32) { 1396 tmpint = tmplong; 1397 error = SYSCTL_OUT(req, &tmpint, sizeof(int)); 1398 } else 1399 #endif 1400 error = SYSCTL_OUT(req, &tmplong, sizeof(long)); 1401 1402 if (error || !req->newptr) 1403 return (error); 1404 1405 if (!arg1) 1406 error = EPERM; 1407 #ifdef SCTL_MASK32 1408 else if (req->flags & SCTL_MASK32) { 1409 error = SYSCTL_IN(req, &tmpint, sizeof(int)); 1410 *(long *)arg1 = (long)tmpint; 1411 } 1412 #endif 1413 else 1414 error = SYSCTL_IN(req, arg1, sizeof(long)); 1415 return (error); 1416 } 1417 1418 /* 1419 * Handle a 64 bit int, signed or unsigned. 1420 * Two cases: 1421 * a variable: point arg1 at it. 1422 * a constant: pass it in arg2. 1423 */ 1424 int 1425 sysctl_handle_64(SYSCTL_HANDLER_ARGS) 1426 { 1427 int error = 0; 1428 uint64_t tmpout; 1429 1430 /* 1431 * Attempt to get a coherent snapshot by making a copy of the data. 1432 */ 1433 if (arg1) 1434 tmpout = *(uint64_t *)arg1; 1435 else 1436 tmpout = arg2; 1437 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t)); 1438 1439 if (error || !req->newptr) 1440 return (error); 1441 1442 if (!arg1) 1443 error = EPERM; 1444 else 1445 error = SYSCTL_IN(req, arg1, sizeof(uint64_t)); 1446 return (error); 1447 } 1448 1449 /* 1450 * Handle our generic '\0' terminated 'C' string. 1451 * Two cases: 1452 * a variable string: point arg1 at it, arg2 is max length. 1453 * a constant string: point arg1 at it, arg2 is zero. 1454 */ 1455 1456 int 1457 sysctl_handle_string(SYSCTL_HANDLER_ARGS) 1458 { 1459 size_t outlen; 1460 int error = 0, ro_string = 0; 1461 1462 /* 1463 * A zero-length buffer indicates a fixed size read-only 1464 * string: 1465 */ 1466 if (arg2 == 0) { 1467 arg2 = strlen((char *)arg1) + 1; 1468 ro_string = 1; 1469 } 1470 1471 if (req->oldptr != NULL) { 1472 char *tmparg; 1473 1474 if (ro_string) { 1475 tmparg = arg1; 1476 } else { 1477 /* try to make a coherent snapshot of the string */ 1478 tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK); 1479 memcpy(tmparg, arg1, arg2); 1480 } 1481 1482 outlen = strnlen(tmparg, arg2 - 1) + 1; 1483 error = SYSCTL_OUT(req, tmparg, outlen); 1484 1485 if (!ro_string) 1486 free(tmparg, M_SYSCTLTMP); 1487 } else { 1488 outlen = strnlen((char *)arg1, arg2 - 1) + 1; 1489 error = SYSCTL_OUT(req, NULL, outlen); 1490 } 1491 if (error || !req->newptr) 1492 return (error); 1493 1494 if ((req->newlen - req->newidx) >= arg2) { 1495 error = EINVAL; 1496 } else { 1497 arg2 = (req->newlen - req->newidx); 1498 error = SYSCTL_IN(req, arg1, arg2); 1499 ((char *)arg1)[arg2] = '\0'; 1500 } 1501 return (error); 1502 } 1503 1504 /* 1505 * Handle any kind of opaque data. 1506 * arg1 points to it, arg2 is the size. 1507 */ 1508 1509 int 1510 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 1511 { 1512 int error, tries; 1513 u_int generation; 1514 struct sysctl_req req2; 1515 1516 /* 1517 * Attempt to get a coherent snapshot, by using the thread 1518 * pre-emption counter updated from within mi_switch() to 1519 * determine if we were pre-empted during a bcopy() or 1520 * copyout(). Make 3 attempts at doing this before giving up. 1521 * If we encounter an error, stop immediately. 1522 */ 1523 tries = 0; 1524 req2 = *req; 1525 retry: 1526 generation = curthread->td_generation; 1527 error = SYSCTL_OUT(req, arg1, arg2); 1528 if (error) 1529 return (error); 1530 tries++; 1531 if (generation != curthread->td_generation && tries < 3) { 1532 *req = req2; 1533 goto retry; 1534 } 1535 1536 error = SYSCTL_IN(req, arg1, arg2); 1537 1538 return (error); 1539 } 1540 1541 /* 1542 * Transfer functions to/from kernel space. 1543 * XXX: rather untested at this point 1544 */ 1545 static int 1546 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 1547 { 1548 size_t i = 0; 1549 1550 if (req->oldptr) { 1551 i = l; 1552 if (req->oldlen <= req->oldidx) 1553 i = 0; 1554 else 1555 if (i > req->oldlen - req->oldidx) 1556 i = req->oldlen - req->oldidx; 1557 if (i > 0) 1558 bcopy(p, (char *)req->oldptr + req->oldidx, i); 1559 } 1560 req->oldidx += l; 1561 if (req->oldptr && i != l) 1562 return (ENOMEM); 1563 return (0); 1564 } 1565 1566 static int 1567 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 1568 { 1569 if (!req->newptr) 1570 return (0); 1571 if (req->newlen - req->newidx < l) 1572 return (EINVAL); 1573 bcopy((char *)req->newptr + req->newidx, p, l); 1574 req->newidx += l; 1575 return (0); 1576 } 1577 1578 int 1579 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1580 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags) 1581 { 1582 int error = 0; 1583 struct sysctl_req req; 1584 1585 bzero(&req, sizeof req); 1586 1587 req.td = td; 1588 req.flags = flags; 1589 1590 if (oldlenp) { 1591 req.oldlen = *oldlenp; 1592 } 1593 req.validlen = req.oldlen; 1594 1595 if (old) { 1596 req.oldptr= old; 1597 } 1598 1599 if (new != NULL) { 1600 req.newlen = newlen; 1601 req.newptr = new; 1602 } 1603 1604 req.oldfunc = sysctl_old_kernel; 1605 req.newfunc = sysctl_new_kernel; 1606 req.lock = REQ_UNWIRED; 1607 1608 error = sysctl_root(0, name, namelen, &req); 1609 1610 if (req.lock == REQ_WIRED && req.validlen > 0) 1611 vsunlock(req.oldptr, req.validlen); 1612 1613 if (error && error != ENOMEM) 1614 return (error); 1615 1616 if (retval) { 1617 if (req.oldptr && req.oldidx > req.validlen) 1618 *retval = req.validlen; 1619 else 1620 *retval = req.oldidx; 1621 } 1622 return (error); 1623 } 1624 1625 int 1626 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp, 1627 void *new, size_t newlen, size_t *retval, int flags) 1628 { 1629 int oid[CTL_MAXNAME]; 1630 size_t oidlen, plen; 1631 int error; 1632 1633 oid[0] = 0; /* sysctl internal magic */ 1634 oid[1] = 3; /* name2oid */ 1635 oidlen = sizeof(oid); 1636 1637 error = kernel_sysctl(td, oid, 2, oid, &oidlen, 1638 (void *)name, strlen(name), &plen, flags); 1639 if (error) 1640 return (error); 1641 1642 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp, 1643 new, newlen, retval, flags); 1644 return (error); 1645 } 1646 1647 /* 1648 * Transfer function to/from user space. 1649 */ 1650 static int 1651 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1652 { 1653 size_t i, len, origidx; 1654 int error; 1655 1656 origidx = req->oldidx; 1657 req->oldidx += l; 1658 if (req->oldptr == NULL) 1659 return (0); 1660 /* 1661 * If we have not wired the user supplied buffer and we are currently 1662 * holding locks, drop a witness warning, as it's possible that 1663 * write operations to the user page can sleep. 1664 */ 1665 if (req->lock != REQ_WIRED) 1666 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1667 "sysctl_old_user()"); 1668 i = l; 1669 len = req->validlen; 1670 if (len <= origidx) 1671 i = 0; 1672 else { 1673 if (i > len - origidx) 1674 i = len - origidx; 1675 if (req->lock == REQ_WIRED) { 1676 error = copyout_nofault(p, (char *)req->oldptr + 1677 origidx, i); 1678 } else 1679 error = copyout(p, (char *)req->oldptr + origidx, i); 1680 if (error != 0) 1681 return (error); 1682 } 1683 if (i < l) 1684 return (ENOMEM); 1685 return (0); 1686 } 1687 1688 static int 1689 sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1690 { 1691 int error; 1692 1693 if (!req->newptr) 1694 return (0); 1695 if (req->newlen - req->newidx < l) 1696 return (EINVAL); 1697 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1698 "sysctl_new_user()"); 1699 error = copyin((char *)req->newptr + req->newidx, p, l); 1700 req->newidx += l; 1701 return (error); 1702 } 1703 1704 /* 1705 * Wire the user space destination buffer. If set to a value greater than 1706 * zero, the len parameter limits the maximum amount of wired memory. 1707 */ 1708 int 1709 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len) 1710 { 1711 int ret; 1712 size_t wiredlen; 1713 1714 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen; 1715 ret = 0; 1716 if (req->lock != REQ_WIRED && req->oldptr && 1717 req->oldfunc == sysctl_old_user) { 1718 if (wiredlen != 0) { 1719 ret = vslock(req->oldptr, wiredlen); 1720 if (ret != 0) { 1721 if (ret != ENOMEM) 1722 return (ret); 1723 wiredlen = 0; 1724 } 1725 } 1726 req->lock = REQ_WIRED; 1727 req->validlen = wiredlen; 1728 } 1729 return (0); 1730 } 1731 1732 int 1733 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1734 int *nindx, struct sysctl_req *req) 1735 { 1736 struct sysctl_oid_list *lsp; 1737 struct sysctl_oid *oid; 1738 int indx; 1739 1740 SYSCTL_ASSERT_LOCKED(); 1741 lsp = &sysctl__children; 1742 indx = 0; 1743 while (indx < CTL_MAXNAME) { 1744 SLIST_FOREACH(oid, lsp, oid_link) { 1745 if (oid->oid_number == name[indx]) 1746 break; 1747 } 1748 if (oid == NULL) 1749 return (ENOENT); 1750 1751 indx++; 1752 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1753 if (oid->oid_handler != NULL || indx == namelen) { 1754 *noid = oid; 1755 if (nindx != NULL) 1756 *nindx = indx; 1757 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1758 ("%s found DYING node %p", __func__, oid)); 1759 return (0); 1760 } 1761 lsp = SYSCTL_CHILDREN(oid); 1762 } else if (indx == namelen) { 1763 *noid = oid; 1764 if (nindx != NULL) 1765 *nindx = indx; 1766 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1767 ("%s found DYING node %p", __func__, oid)); 1768 return (0); 1769 } else { 1770 return (ENOTDIR); 1771 } 1772 } 1773 return (ENOENT); 1774 } 1775 1776 /* 1777 * Traverse our tree, and find the right node, execute whatever it points 1778 * to, and return the resulting error code. 1779 */ 1780 1781 static int 1782 sysctl_root(SYSCTL_HANDLER_ARGS) 1783 { 1784 struct sysctl_oid *oid; 1785 struct rm_priotracker tracker; 1786 int error, indx, lvl; 1787 1788 SYSCTL_RLOCK(&tracker); 1789 1790 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1791 if (error) 1792 goto out; 1793 1794 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1795 /* 1796 * You can't call a sysctl when it's a node, but has 1797 * no handler. Inform the user that it's a node. 1798 * The indx may or may not be the same as namelen. 1799 */ 1800 if (oid->oid_handler == NULL) { 1801 error = EISDIR; 1802 goto out; 1803 } 1804 } 1805 1806 /* Is this sysctl writable? */ 1807 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) { 1808 error = EPERM; 1809 goto out; 1810 } 1811 1812 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL")); 1813 1814 #ifdef CAPABILITY_MODE 1815 /* 1816 * If the process is in capability mode, then don't permit reading or 1817 * writing unless specifically granted for the node. 1818 */ 1819 if (IN_CAPABILITY_MODE(req->td)) { 1820 if ((req->oldptr && !(oid->oid_kind & CTLFLAG_CAPRD)) || 1821 (req->newptr && !(oid->oid_kind & CTLFLAG_CAPWR))) { 1822 error = EPERM; 1823 goto out; 1824 } 1825 } 1826 #endif 1827 1828 /* Is this sysctl sensitive to securelevels? */ 1829 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) { 1830 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE; 1831 error = securelevel_gt(req->td->td_ucred, lvl); 1832 if (error) 1833 goto out; 1834 } 1835 1836 /* Is this sysctl writable by only privileged users? */ 1837 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) { 1838 int priv; 1839 1840 if (oid->oid_kind & CTLFLAG_PRISON) 1841 priv = PRIV_SYSCTL_WRITEJAIL; 1842 #ifdef VIMAGE 1843 else if ((oid->oid_kind & CTLFLAG_VNET) && 1844 prison_owns_vnet(req->td->td_ucred)) 1845 priv = PRIV_SYSCTL_WRITEJAIL; 1846 #endif 1847 else 1848 priv = PRIV_SYSCTL_WRITE; 1849 error = priv_check(req->td, priv); 1850 if (error) 1851 goto out; 1852 } 1853 1854 if (!oid->oid_handler) { 1855 error = EINVAL; 1856 goto out; 1857 } 1858 1859 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1860 arg1 = (int *)arg1 + indx; 1861 arg2 -= indx; 1862 } else { 1863 arg1 = oid->oid_arg1; 1864 arg2 = oid->oid_arg2; 1865 } 1866 #ifdef MAC 1867 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2, 1868 req); 1869 if (error != 0) 1870 goto out; 1871 #endif 1872 #ifdef VIMAGE 1873 if ((oid->oid_kind & CTLFLAG_VNET) && arg1 != NULL) 1874 arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1); 1875 #endif 1876 error = sysctl_root_handler_locked(oid, arg1, arg2, req, &tracker); 1877 1878 out: 1879 SYSCTL_RUNLOCK(&tracker); 1880 return (error); 1881 } 1882 1883 #ifndef _SYS_SYSPROTO_H_ 1884 struct sysctl_args { 1885 int *name; 1886 u_int namelen; 1887 void *old; 1888 size_t *oldlenp; 1889 void *new; 1890 size_t newlen; 1891 }; 1892 #endif 1893 int 1894 sys___sysctl(struct thread *td, struct sysctl_args *uap) 1895 { 1896 int error, i, name[CTL_MAXNAME]; 1897 size_t j; 1898 1899 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 1900 return (EINVAL); 1901 1902 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 1903 if (error) 1904 return (error); 1905 1906 error = userland_sysctl(td, name, uap->namelen, 1907 uap->old, uap->oldlenp, 0, 1908 uap->new, uap->newlen, &j, 0); 1909 if (error && error != ENOMEM) 1910 return (error); 1911 if (uap->oldlenp) { 1912 i = copyout(&j, uap->oldlenp, sizeof(j)); 1913 if (i) 1914 return (i); 1915 } 1916 return (error); 1917 } 1918 1919 /* 1920 * This is used from various compatibility syscalls too. That's why name 1921 * must be in kernel space. 1922 */ 1923 int 1924 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1925 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval, 1926 int flags) 1927 { 1928 int error = 0, memlocked; 1929 struct sysctl_req req; 1930 1931 bzero(&req, sizeof req); 1932 1933 req.td = td; 1934 req.flags = flags; 1935 1936 if (oldlenp) { 1937 if (inkernel) { 1938 req.oldlen = *oldlenp; 1939 } else { 1940 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 1941 if (error) 1942 return (error); 1943 } 1944 } 1945 req.validlen = req.oldlen; 1946 1947 if (old) { 1948 if (!useracc(old, req.oldlen, VM_PROT_WRITE)) 1949 return (EFAULT); 1950 req.oldptr= old; 1951 } 1952 1953 if (new != NULL) { 1954 if (!useracc(new, newlen, VM_PROT_READ)) 1955 return (EFAULT); 1956 req.newlen = newlen; 1957 req.newptr = new; 1958 } 1959 1960 req.oldfunc = sysctl_old_user; 1961 req.newfunc = sysctl_new_user; 1962 req.lock = REQ_UNWIRED; 1963 1964 #ifdef KTRACE 1965 if (KTRPOINT(curthread, KTR_SYSCTL)) 1966 ktrsysctl(name, namelen); 1967 #endif 1968 1969 if (req.oldptr && req.oldlen > PAGE_SIZE) { 1970 memlocked = 1; 1971 sx_xlock(&sysctlmemlock); 1972 } else 1973 memlocked = 0; 1974 CURVNET_SET(TD_TO_VNET(td)); 1975 1976 for (;;) { 1977 req.oldidx = 0; 1978 req.newidx = 0; 1979 error = sysctl_root(0, name, namelen, &req); 1980 if (error != EAGAIN) 1981 break; 1982 kern_yield(PRI_USER); 1983 } 1984 1985 CURVNET_RESTORE(); 1986 1987 if (req.lock == REQ_WIRED && req.validlen > 0) 1988 vsunlock(req.oldptr, req.validlen); 1989 if (memlocked) 1990 sx_xunlock(&sysctlmemlock); 1991 1992 if (error && error != ENOMEM) 1993 return (error); 1994 1995 if (retval) { 1996 if (req.oldptr && req.oldidx > req.validlen) 1997 *retval = req.validlen; 1998 else 1999 *retval = req.oldidx; 2000 } 2001 return (error); 2002 } 2003 2004 /* 2005 * Drain into a sysctl struct. The user buffer should be wired if a page 2006 * fault would cause issue. 2007 */ 2008 static int 2009 sbuf_sysctl_drain(void *arg, const char *data, int len) 2010 { 2011 struct sysctl_req *req = arg; 2012 int error; 2013 2014 error = SYSCTL_OUT(req, data, len); 2015 KASSERT(error >= 0, ("Got unexpected negative value %d", error)); 2016 return (error == 0 ? len : -error); 2017 } 2018 2019 struct sbuf * 2020 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length, 2021 struct sysctl_req *req) 2022 { 2023 2024 /* Supply a default buffer size if none given. */ 2025 if (buf == NULL && length == 0) 2026 length = 64; 2027 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN | SBUF_INCLUDENUL); 2028 sbuf_set_drain(s, sbuf_sysctl_drain, req); 2029 return (s); 2030 }
Cache object: c7b2be6c6a02ec95cd1c2519cab0824d
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