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