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 int oid_number; 300 int timeout = 2; 301 302 /* 303 * First check if another oid with the same name already 304 * exists in the parent's list. 305 */ 306 SYSCTL_ASSERT_XLOCKED(); 307 p = sysctl_find_oidname(oidp->oid_name, parent); 308 if (p != NULL) { 309 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 310 p->oid_refcnt++; 311 return; 312 } else { 313 printf("can't re-use a leaf (%s)!\n", p->oid_name); 314 return; 315 } 316 } 317 /* get current OID number */ 318 oid_number = oidp->oid_number; 319 320 #if (OID_AUTO >= 0) 321 #error "OID_AUTO is expected to be a negative value" 322 #endif 323 /* 324 * Any negative OID number qualifies as OID_AUTO. Valid OID 325 * numbers should always be positive. 326 * 327 * NOTE: DO NOT change the starting value here, change it in 328 * <sys/sysctl.h>, and make sure it is at least 256 to 329 * accomodate e.g. net.inet.raw as a static sysctl node. 330 */ 331 if (oid_number < 0) { 332 static int newoid; 333 334 /* 335 * By decrementing the next OID number we spend less 336 * time inserting the OIDs into a sorted list. 337 */ 338 if (--newoid < CTL_AUTO_START) 339 newoid = 0x7fffffff; 340 341 oid_number = newoid; 342 } 343 344 /* 345 * Insert the OID into the parent's list sorted by OID number. 346 */ 347 retry: 348 q = NULL; 349 SLIST_FOREACH(p, parent, oid_link) { 350 /* check if the current OID number is in use */ 351 if (oid_number == p->oid_number) { 352 /* get the next valid OID number */ 353 if (oid_number < CTL_AUTO_START || 354 oid_number == 0x7fffffff) { 355 /* wraparound - restart */ 356 oid_number = CTL_AUTO_START; 357 /* don't loop forever */ 358 if (!timeout--) 359 panic("sysctl: Out of OID numbers\n"); 360 goto retry; 361 } else { 362 oid_number++; 363 } 364 } else if (oid_number < p->oid_number) 365 break; 366 q = p; 367 } 368 /* check for non-auto OID number collision */ 369 if (oidp->oid_number >= 0 && oidp->oid_number < CTL_AUTO_START && 370 oid_number >= CTL_AUTO_START) { 371 printf("sysctl: OID number(%d) is already in use for '%s'\n", 372 oidp->oid_number, oidp->oid_name); 373 } 374 /* update the OID number, if any */ 375 oidp->oid_number = oid_number; 376 if (q != NULL) 377 SLIST_INSERT_AFTER(q, oidp, oid_link); 378 else 379 SLIST_INSERT_HEAD(parent, oidp, oid_link); 380 381 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE && 382 #ifdef VIMAGE 383 (oidp->oid_kind & CTLFLAG_VNET) == 0 && 384 #endif 385 (oidp->oid_kind & CTLFLAG_TUN) != 0 && 386 (oidp->oid_kind & CTLFLAG_NOFETCH) == 0) { 387 /* only fetch value once */ 388 oidp->oid_kind |= CTLFLAG_NOFETCH; 389 /* try to fetch value from kernel environment */ 390 sysctl_load_tunable_by_oid_locked(oidp); 391 } 392 } 393 394 void 395 sysctl_unregister_oid(struct sysctl_oid *oidp) 396 { 397 struct sysctl_oid *p; 398 int error; 399 400 SYSCTL_ASSERT_XLOCKED(); 401 error = ENOENT; 402 if (oidp->oid_number == OID_AUTO) { 403 error = EINVAL; 404 } else { 405 SLIST_FOREACH(p, oidp->oid_parent, oid_link) { 406 if (p == oidp) { 407 SLIST_REMOVE(oidp->oid_parent, oidp, 408 sysctl_oid, oid_link); 409 error = 0; 410 break; 411 } 412 } 413 } 414 415 /* 416 * This can happen when a module fails to register and is 417 * being unloaded afterwards. It should not be a panic() 418 * for normal use. 419 */ 420 if (error) 421 printf("%s: failed to unregister sysctl\n", __func__); 422 } 423 424 /* Initialize a new context to keep track of dynamically added sysctls. */ 425 int 426 sysctl_ctx_init(struct sysctl_ctx_list *c) 427 { 428 429 if (c == NULL) { 430 return (EINVAL); 431 } 432 433 /* 434 * No locking here, the caller is responsible for not adding 435 * new nodes to a context until after this function has 436 * returned. 437 */ 438 TAILQ_INIT(c); 439 return (0); 440 } 441 442 /* Free the context, and destroy all dynamic oids registered in this context */ 443 int 444 sysctl_ctx_free(struct sysctl_ctx_list *clist) 445 { 446 struct sysctl_ctx_entry *e, *e1; 447 int error; 448 449 error = 0; 450 /* 451 * First perform a "dry run" to check if it's ok to remove oids. 452 * XXX FIXME 453 * XXX This algorithm is a hack. But I don't know any 454 * XXX better solution for now... 455 */ 456 SYSCTL_XLOCK(); 457 TAILQ_FOREACH(e, clist, link) { 458 error = sysctl_remove_oid_locked(e->entry, 0, 0); 459 if (error) 460 break; 461 } 462 /* 463 * Restore deregistered entries, either from the end, 464 * or from the place where error occured. 465 * e contains the entry that was not unregistered 466 */ 467 if (error) 468 e1 = TAILQ_PREV(e, sysctl_ctx_list, link); 469 else 470 e1 = TAILQ_LAST(clist, sysctl_ctx_list); 471 while (e1 != NULL) { 472 sysctl_register_oid(e1->entry); 473 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link); 474 } 475 if (error) { 476 SYSCTL_XUNLOCK(); 477 return(EBUSY); 478 } 479 /* Now really delete the entries */ 480 e = TAILQ_FIRST(clist); 481 while (e != NULL) { 482 e1 = TAILQ_NEXT(e, link); 483 error = sysctl_remove_oid_locked(e->entry, 1, 0); 484 if (error) 485 panic("sysctl_remove_oid: corrupt tree, entry: %s", 486 e->entry->oid_name); 487 free(e, M_SYSCTLOID); 488 e = e1; 489 } 490 SYSCTL_XUNLOCK(); 491 return (error); 492 } 493 494 /* Add an entry to the context */ 495 struct sysctl_ctx_entry * 496 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 497 { 498 struct sysctl_ctx_entry *e; 499 500 SYSCTL_ASSERT_XLOCKED(); 501 if (clist == NULL || oidp == NULL) 502 return(NULL); 503 e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK); 504 e->entry = oidp; 505 TAILQ_INSERT_HEAD(clist, e, link); 506 return (e); 507 } 508 509 /* Find an entry in the context */ 510 struct sysctl_ctx_entry * 511 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 512 { 513 struct sysctl_ctx_entry *e; 514 515 SYSCTL_ASSERT_XLOCKED(); 516 if (clist == NULL || oidp == NULL) 517 return(NULL); 518 TAILQ_FOREACH(e, clist, link) { 519 if(e->entry == oidp) 520 return(e); 521 } 522 return (e); 523 } 524 525 /* 526 * Delete an entry from the context. 527 * NOTE: this function doesn't free oidp! You have to remove it 528 * with sysctl_remove_oid(). 529 */ 530 int 531 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 532 { 533 struct sysctl_ctx_entry *e; 534 535 if (clist == NULL || oidp == NULL) 536 return (EINVAL); 537 SYSCTL_XLOCK(); 538 e = sysctl_ctx_entry_find(clist, oidp); 539 if (e != NULL) { 540 TAILQ_REMOVE(clist, e, link); 541 SYSCTL_XUNLOCK(); 542 free(e, M_SYSCTLOID); 543 return (0); 544 } else { 545 SYSCTL_XUNLOCK(); 546 return (ENOENT); 547 } 548 } 549 550 /* 551 * Remove dynamically created sysctl trees. 552 * oidp - top of the tree to be removed 553 * del - if 0 - just deregister, otherwise free up entries as well 554 * recurse - if != 0 traverse the subtree to be deleted 555 */ 556 int 557 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse) 558 { 559 int error; 560 561 SYSCTL_XLOCK(); 562 error = sysctl_remove_oid_locked(oidp, del, recurse); 563 SYSCTL_XUNLOCK(); 564 return (error); 565 } 566 567 int 568 sysctl_remove_name(struct sysctl_oid *parent, const char *name, 569 int del, int recurse) 570 { 571 struct sysctl_oid *p, *tmp; 572 int error; 573 574 error = ENOENT; 575 SYSCTL_XLOCK(); 576 SLIST_FOREACH_SAFE(p, SYSCTL_CHILDREN(parent), oid_link, tmp) { 577 if (strcmp(p->oid_name, name) == 0) { 578 error = sysctl_remove_oid_locked(p, del, recurse); 579 break; 580 } 581 } 582 SYSCTL_XUNLOCK(); 583 584 return (error); 585 } 586 587 588 static int 589 sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse) 590 { 591 struct sysctl_oid *p, *tmp; 592 int error; 593 594 SYSCTL_ASSERT_XLOCKED(); 595 if (oidp == NULL) 596 return(EINVAL); 597 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) { 598 printf("can't remove non-dynamic nodes!\n"); 599 return (EINVAL); 600 } 601 /* 602 * WARNING: normal method to do this should be through 603 * sysctl_ctx_free(). Use recursing as the last resort 604 * method to purge your sysctl tree of leftovers... 605 * However, if some other code still references these nodes, 606 * it will panic. 607 */ 608 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 609 if (oidp->oid_refcnt == 1) { 610 SLIST_FOREACH_SAFE(p, 611 SYSCTL_CHILDREN(oidp), oid_link, tmp) { 612 if (!recurse) { 613 printf("Warning: failed attempt to " 614 "remove oid %s with child %s\n", 615 oidp->oid_name, p->oid_name); 616 return (ENOTEMPTY); 617 } 618 error = sysctl_remove_oid_locked(p, del, 619 recurse); 620 if (error) 621 return (error); 622 } 623 } 624 } 625 if (oidp->oid_refcnt > 1 ) { 626 oidp->oid_refcnt--; 627 } else { 628 if (oidp->oid_refcnt == 0) { 629 printf("Warning: bad oid_refcnt=%u (%s)!\n", 630 oidp->oid_refcnt, oidp->oid_name); 631 return (EINVAL); 632 } 633 sysctl_unregister_oid(oidp); 634 if (del) { 635 /* 636 * Wait for all threads running the handler to drain. 637 * This preserves the previous behavior when the 638 * sysctl lock was held across a handler invocation, 639 * and is necessary for module unload correctness. 640 */ 641 while (oidp->oid_running > 0) { 642 oidp->oid_kind |= CTLFLAG_DYING; 643 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0); 644 } 645 if (oidp->oid_descr) 646 free(__DECONST(char *, oidp->oid_descr), 647 M_SYSCTLOID); 648 free(__DECONST(char *, oidp->oid_name), M_SYSCTLOID); 649 free(oidp, M_SYSCTLOID); 650 } 651 } 652 return (0); 653 } 654 /* 655 * Create new sysctls at run time. 656 * clist may point to a valid context initialized with sysctl_ctx_init(). 657 */ 658 struct sysctl_oid * 659 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, 660 int number, const char *name, int kind, void *arg1, intptr_t arg2, 661 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr) 662 { 663 struct sysctl_oid *oidp; 664 665 /* You have to hook up somewhere.. */ 666 if (parent == NULL) 667 return(NULL); 668 /* Check if the node already exists, otherwise create it */ 669 SYSCTL_XLOCK(); 670 oidp = sysctl_find_oidname(name, parent); 671 if (oidp != NULL) { 672 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 673 oidp->oid_refcnt++; 674 /* Update the context */ 675 if (clist != NULL) 676 sysctl_ctx_entry_add(clist, oidp); 677 SYSCTL_XUNLOCK(); 678 return (oidp); 679 } else { 680 SYSCTL_XUNLOCK(); 681 printf("can't re-use a leaf (%s)!\n", name); 682 return (NULL); 683 } 684 } 685 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO); 686 oidp->oid_parent = parent; 687 SLIST_INIT(&oidp->oid_children); 688 oidp->oid_number = number; 689 oidp->oid_refcnt = 1; 690 oidp->oid_name = strdup(name, M_SYSCTLOID); 691 oidp->oid_handler = handler; 692 oidp->oid_kind = CTLFLAG_DYN | kind; 693 oidp->oid_arg1 = arg1; 694 oidp->oid_arg2 = arg2; 695 oidp->oid_fmt = fmt; 696 if (descr != NULL) 697 oidp->oid_descr = strdup(descr, M_SYSCTLOID); 698 /* Update the context, if used */ 699 if (clist != NULL) 700 sysctl_ctx_entry_add(clist, oidp); 701 /* Register this oid */ 702 sysctl_register_oid(oidp); 703 SYSCTL_XUNLOCK(); 704 return (oidp); 705 } 706 707 /* 708 * Rename an existing oid. 709 */ 710 void 711 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) 712 { 713 char *newname; 714 char *oldname; 715 716 newname = strdup(name, M_SYSCTLOID); 717 SYSCTL_XLOCK(); 718 oldname = __DECONST(char *, oidp->oid_name); 719 oidp->oid_name = newname; 720 SYSCTL_XUNLOCK(); 721 free(oldname, M_SYSCTLOID); 722 } 723 724 /* 725 * Reparent an existing oid. 726 */ 727 int 728 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent) 729 { 730 struct sysctl_oid *oidp; 731 732 SYSCTL_XLOCK(); 733 if (oid->oid_parent == parent) { 734 SYSCTL_XUNLOCK(); 735 return (0); 736 } 737 oidp = sysctl_find_oidname(oid->oid_name, parent); 738 if (oidp != NULL) { 739 SYSCTL_XUNLOCK(); 740 return (EEXIST); 741 } 742 sysctl_unregister_oid(oid); 743 oid->oid_parent = parent; 744 oid->oid_number = OID_AUTO; 745 sysctl_register_oid(oid); 746 SYSCTL_XUNLOCK(); 747 return (0); 748 } 749 750 /* 751 * Register the kernel's oids on startup. 752 */ 753 SET_DECLARE(sysctl_set, struct sysctl_oid); 754 755 static void 756 sysctl_register_all(void *arg) 757 { 758 struct sysctl_oid **oidp; 759 760 sx_init(&sysctlmemlock, "sysctl mem"); 761 SYSCTL_INIT(); 762 SYSCTL_XLOCK(); 763 SET_FOREACH(oidp, sysctl_set) 764 sysctl_register_oid(*oidp); 765 SYSCTL_XUNLOCK(); 766 } 767 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_FIRST, sysctl_register_all, 0); 768 769 /* 770 * "Staff-functions" 771 * 772 * These functions implement a presently undocumented interface 773 * used by the sysctl program to walk the tree, and get the type 774 * so it can print the value. 775 * This interface is under work and consideration, and should probably 776 * be killed with a big axe by the first person who can find the time. 777 * (be aware though, that the proper interface isn't as obvious as it 778 * may seem, there are various conflicting requirements. 779 * 780 * {0,0} printf the entire MIB-tree. 781 * {0,1,...} return the name of the "..." OID. 782 * {0,2,...} return the next OID. 783 * {0,3} return the OID of the name in "new" 784 * {0,4,...} return the kind & format info for the "..." OID. 785 * {0,5,...} return the description the "..." OID. 786 */ 787 788 #ifdef SYSCTL_DEBUG 789 static void 790 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 791 { 792 int k; 793 struct sysctl_oid *oidp; 794 795 SYSCTL_ASSERT_LOCKED(); 796 SLIST_FOREACH(oidp, l, oid_link) { 797 798 for (k=0; k<i; k++) 799 printf(" "); 800 801 printf("%d %s ", oidp->oid_number, oidp->oid_name); 802 803 printf("%c%c", 804 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 805 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 806 807 if (oidp->oid_handler) 808 printf(" *Handler"); 809 810 switch (oidp->oid_kind & CTLTYPE) { 811 case CTLTYPE_NODE: 812 printf(" Node\n"); 813 if (!oidp->oid_handler) { 814 sysctl_sysctl_debug_dump_node( 815 SYSCTL_CHILDREN(oidp), i + 2); 816 } 817 break; 818 case CTLTYPE_INT: printf(" Int\n"); break; 819 case CTLTYPE_UINT: printf(" u_int\n"); break; 820 case CTLTYPE_LONG: printf(" Long\n"); break; 821 case CTLTYPE_ULONG: printf(" u_long\n"); break; 822 case CTLTYPE_STRING: printf(" String\n"); break; 823 case CTLTYPE_U64: printf(" uint64_t\n"); break; 824 case CTLTYPE_S64: printf(" int64_t\n"); break; 825 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break; 826 default: printf("\n"); 827 } 828 829 } 830 } 831 832 static int 833 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 834 { 835 int error; 836 837 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 838 if (error) 839 return (error); 840 SYSCTL_SLOCK(); 841 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 842 SYSCTL_SUNLOCK(); 843 return (ENOENT); 844 } 845 846 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE, 847 0, 0, sysctl_sysctl_debug, "-", ""); 848 #endif 849 850 static int 851 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 852 { 853 int *name = (int *) arg1; 854 u_int namelen = arg2; 855 int error = 0; 856 struct sysctl_oid *oid; 857 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 858 char buf[10]; 859 860 SYSCTL_SLOCK(); 861 while (namelen) { 862 if (!lsp) { 863 snprintf(buf,sizeof(buf),"%d",*name); 864 if (req->oldidx) 865 error = SYSCTL_OUT(req, ".", 1); 866 if (!error) 867 error = SYSCTL_OUT(req, buf, strlen(buf)); 868 if (error) 869 goto out; 870 namelen--; 871 name++; 872 continue; 873 } 874 lsp2 = 0; 875 SLIST_FOREACH(oid, lsp, oid_link) { 876 if (oid->oid_number != *name) 877 continue; 878 879 if (req->oldidx) 880 error = SYSCTL_OUT(req, ".", 1); 881 if (!error) 882 error = SYSCTL_OUT(req, oid->oid_name, 883 strlen(oid->oid_name)); 884 if (error) 885 goto out; 886 887 namelen--; 888 name++; 889 890 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 891 break; 892 893 if (oid->oid_handler) 894 break; 895 896 lsp2 = SYSCTL_CHILDREN(oid); 897 break; 898 } 899 lsp = lsp2; 900 } 901 error = SYSCTL_OUT(req, "", 1); 902 out: 903 SYSCTL_SUNLOCK(); 904 return (error); 905 } 906 907 /* 908 * XXXRW/JA: Shouldn't return name data for nodes that we don't permit in 909 * capability mode. 910 */ 911 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, 912 sysctl_sysctl_name, ""); 913 914 static int 915 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 916 int *next, int *len, int level, struct sysctl_oid **oidpp) 917 { 918 struct sysctl_oid *oidp; 919 920 SYSCTL_ASSERT_LOCKED(); 921 *len = level; 922 SLIST_FOREACH(oidp, lsp, oid_link) { 923 *next = oidp->oid_number; 924 *oidpp = oidp; 925 926 if (oidp->oid_kind & CTLFLAG_SKIP) 927 continue; 928 929 if (!namelen) { 930 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 931 return (0); 932 if (oidp->oid_handler) 933 /* We really should call the handler here...*/ 934 return (0); 935 lsp = SYSCTL_CHILDREN(oidp); 936 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 937 len, level+1, oidpp)) 938 return (0); 939 goto emptynode; 940 } 941 942 if (oidp->oid_number < *name) 943 continue; 944 945 if (oidp->oid_number > *name) { 946 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 947 return (0); 948 if (oidp->oid_handler) 949 return (0); 950 lsp = SYSCTL_CHILDREN(oidp); 951 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 952 next+1, len, level+1, oidpp)) 953 return (0); 954 goto next; 955 } 956 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 957 continue; 958 959 if (oidp->oid_handler) 960 continue; 961 962 lsp = SYSCTL_CHILDREN(oidp); 963 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 964 len, level+1, oidpp)) 965 return (0); 966 next: 967 namelen = 1; 968 emptynode: 969 *len = level; 970 } 971 return (1); 972 } 973 974 static int 975 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 976 { 977 int *name = (int *) arg1; 978 u_int namelen = arg2; 979 int i, j, error; 980 struct sysctl_oid *oid; 981 struct sysctl_oid_list *lsp = &sysctl__children; 982 int newoid[CTL_MAXNAME]; 983 984 SYSCTL_SLOCK(); 985 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 986 SYSCTL_SUNLOCK(); 987 if (i) 988 return (ENOENT); 989 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 990 return (error); 991 } 992 993 /* 994 * XXXRW/JA: Shouldn't return next data for nodes that we don't permit in 995 * capability mode. 996 */ 997 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, 998 sysctl_sysctl_next, ""); 999 1000 static int 1001 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) 1002 { 1003 struct sysctl_oid *oidp; 1004 struct sysctl_oid_list *lsp = &sysctl__children; 1005 char *p; 1006 1007 SYSCTL_ASSERT_LOCKED(); 1008 1009 for (*len = 0; *len < CTL_MAXNAME;) { 1010 p = strsep(&name, "."); 1011 1012 oidp = SLIST_FIRST(lsp); 1013 for (;; oidp = SLIST_NEXT(oidp, oid_link)) { 1014 if (oidp == NULL) 1015 return (ENOENT); 1016 if (strcmp(p, oidp->oid_name) == 0) 1017 break; 1018 } 1019 *oid++ = oidp->oid_number; 1020 (*len)++; 1021 1022 if (name == NULL || *name == '\0') { 1023 if (oidpp) 1024 *oidpp = oidp; 1025 return (0); 1026 } 1027 1028 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 1029 break; 1030 1031 if (oidp->oid_handler) 1032 break; 1033 1034 lsp = SYSCTL_CHILDREN(oidp); 1035 } 1036 return (ENOENT); 1037 } 1038 1039 static int 1040 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 1041 { 1042 char *p; 1043 int error, oid[CTL_MAXNAME], len = 0; 1044 struct sysctl_oid *op = 0; 1045 1046 if (!req->newlen) 1047 return (ENOENT); 1048 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 1049 return (ENAMETOOLONG); 1050 1051 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK); 1052 1053 error = SYSCTL_IN(req, p, req->newlen); 1054 if (error) { 1055 free(p, M_SYSCTL); 1056 return (error); 1057 } 1058 1059 p [req->newlen] = '\0'; 1060 1061 SYSCTL_SLOCK(); 1062 error = name2oid(p, oid, &len, &op); 1063 SYSCTL_SUNLOCK(); 1064 1065 free(p, M_SYSCTL); 1066 1067 if (error) 1068 return (error); 1069 1070 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 1071 return (error); 1072 } 1073 1074 /* 1075 * XXXRW/JA: Shouldn't return name2oid data for nodes that we don't permit in 1076 * capability mode. 1077 */ 1078 SYSCTL_PROC(_sysctl, 3, name2oid, 1079 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE 1080 | CTLFLAG_CAPRW, 0, 0, sysctl_sysctl_name2oid, "I", ""); 1081 1082 static int 1083 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 1084 { 1085 struct sysctl_oid *oid; 1086 int error; 1087 1088 SYSCTL_SLOCK(); 1089 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 1090 if (error) 1091 goto out; 1092 1093 if (oid->oid_fmt == NULL) { 1094 error = ENOENT; 1095 goto out; 1096 } 1097 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 1098 if (error) 1099 goto out; 1100 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 1101 out: 1102 SYSCTL_SUNLOCK(); 1103 return (error); 1104 } 1105 1106 1107 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD, 1108 sysctl_sysctl_oidfmt, ""); 1109 1110 static int 1111 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 1112 { 1113 struct sysctl_oid *oid; 1114 int error; 1115 1116 SYSCTL_SLOCK(); 1117 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 1118 if (error) 1119 goto out; 1120 1121 if (oid->oid_descr == NULL) { 1122 error = ENOENT; 1123 goto out; 1124 } 1125 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 1126 out: 1127 SYSCTL_SUNLOCK(); 1128 return (error); 1129 } 1130 1131 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD, 1132 sysctl_sysctl_oiddescr, ""); 1133 1134 /* 1135 * Default "handler" functions. 1136 */ 1137 1138 /* 1139 * Handle an int, signed or unsigned. 1140 * Two cases: 1141 * a variable: point arg1 at it. 1142 * a constant: pass it in arg2. 1143 */ 1144 1145 int 1146 sysctl_handle_int(SYSCTL_HANDLER_ARGS) 1147 { 1148 int tmpout, error = 0; 1149 1150 /* 1151 * Attempt to get a coherent snapshot by making a copy of the data. 1152 */ 1153 if (arg1) 1154 tmpout = *(int *)arg1; 1155 else 1156 tmpout = arg2; 1157 error = SYSCTL_OUT(req, &tmpout, sizeof(int)); 1158 1159 if (error || !req->newptr) 1160 return (error); 1161 1162 if (!arg1) 1163 error = EPERM; 1164 else 1165 error = SYSCTL_IN(req, arg1, sizeof(int)); 1166 return (error); 1167 } 1168 1169 /* 1170 * Based on on sysctl_handle_int() convert milliseconds into ticks. 1171 * Note: this is used by TCP. 1172 */ 1173 1174 int 1175 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) 1176 { 1177 int error, s, tt; 1178 1179 tt = *(int *)arg1; 1180 s = (int)((int64_t)tt * 1000 / hz); 1181 1182 error = sysctl_handle_int(oidp, &s, 0, req); 1183 if (error || !req->newptr) 1184 return (error); 1185 1186 tt = (int)((int64_t)s * hz / 1000); 1187 if (tt < 1) 1188 return (EINVAL); 1189 1190 *(int *)arg1 = tt; 1191 return (0); 1192 } 1193 1194 1195 /* 1196 * Handle a long, signed or unsigned. 1197 * Two cases: 1198 * a variable: point arg1 at it. 1199 * a constant: pass it in arg2. 1200 */ 1201 1202 int 1203 sysctl_handle_long(SYSCTL_HANDLER_ARGS) 1204 { 1205 int error = 0; 1206 long tmplong; 1207 #ifdef SCTL_MASK32 1208 int tmpint; 1209 #endif 1210 1211 /* 1212 * Attempt to get a coherent snapshot by making a copy of the data. 1213 */ 1214 if (arg1) 1215 tmplong = *(long *)arg1; 1216 else 1217 tmplong = arg2; 1218 #ifdef SCTL_MASK32 1219 if (req->flags & SCTL_MASK32) { 1220 tmpint = tmplong; 1221 error = SYSCTL_OUT(req, &tmpint, sizeof(int)); 1222 } else 1223 #endif 1224 error = SYSCTL_OUT(req, &tmplong, sizeof(long)); 1225 1226 if (error || !req->newptr) 1227 return (error); 1228 1229 if (!arg1) 1230 error = EPERM; 1231 #ifdef SCTL_MASK32 1232 else if (req->flags & SCTL_MASK32) { 1233 error = SYSCTL_IN(req, &tmpint, sizeof(int)); 1234 *(long *)arg1 = (long)tmpint; 1235 } 1236 #endif 1237 else 1238 error = SYSCTL_IN(req, arg1, sizeof(long)); 1239 return (error); 1240 } 1241 1242 /* 1243 * Handle a 64 bit int, signed or unsigned. 1244 * Two cases: 1245 * a variable: point arg1 at it. 1246 * a constant: pass it in arg2. 1247 */ 1248 int 1249 sysctl_handle_64(SYSCTL_HANDLER_ARGS) 1250 { 1251 int error = 0; 1252 uint64_t tmpout; 1253 1254 /* 1255 * Attempt to get a coherent snapshot by making a copy of the data. 1256 */ 1257 if (arg1) 1258 tmpout = *(uint64_t *)arg1; 1259 else 1260 tmpout = arg2; 1261 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t)); 1262 1263 if (error || !req->newptr) 1264 return (error); 1265 1266 if (!arg1) 1267 error = EPERM; 1268 else 1269 error = SYSCTL_IN(req, arg1, sizeof(uint64_t)); 1270 return (error); 1271 } 1272 1273 /* 1274 * Handle our generic '\0' terminated 'C' string. 1275 * Two cases: 1276 * a variable string: point arg1 at it, arg2 is max length. 1277 * a constant string: point arg1 at it, arg2 is zero. 1278 */ 1279 1280 int 1281 sysctl_handle_string(SYSCTL_HANDLER_ARGS) 1282 { 1283 size_t outlen; 1284 int error = 0, ro_string = 0; 1285 1286 /* 1287 * A zero-length buffer indicates a fixed size read-only 1288 * string: 1289 */ 1290 if (arg2 == 0) { 1291 arg2 = strlen((char *)arg1) + 1; 1292 ro_string = 1; 1293 } 1294 1295 if (req->oldptr != NULL) { 1296 char *tmparg; 1297 1298 if (ro_string) { 1299 tmparg = arg1; 1300 } else { 1301 /* try to make a coherent snapshot of the string */ 1302 tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK); 1303 memcpy(tmparg, arg1, arg2); 1304 } 1305 1306 outlen = strnlen(tmparg, arg2 - 1) + 1; 1307 error = SYSCTL_OUT(req, tmparg, outlen); 1308 1309 if (!ro_string) 1310 free(tmparg, M_SYSCTLTMP); 1311 } else { 1312 outlen = strnlen((char *)arg1, arg2 - 1) + 1; 1313 error = SYSCTL_OUT(req, NULL, outlen); 1314 } 1315 if (error || !req->newptr) 1316 return (error); 1317 1318 if ((req->newlen - req->newidx) >= arg2) { 1319 error = EINVAL; 1320 } else { 1321 arg2 = (req->newlen - req->newidx); 1322 error = SYSCTL_IN(req, arg1, arg2); 1323 ((char *)arg1)[arg2] = '\0'; 1324 } 1325 return (error); 1326 } 1327 1328 /* 1329 * Handle any kind of opaque data. 1330 * arg1 points to it, arg2 is the size. 1331 */ 1332 1333 int 1334 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 1335 { 1336 int error, tries; 1337 u_int generation; 1338 struct sysctl_req req2; 1339 1340 /* 1341 * Attempt to get a coherent snapshot, by using the thread 1342 * pre-emption counter updated from within mi_switch() to 1343 * determine if we were pre-empted during a bcopy() or 1344 * copyout(). Make 3 attempts at doing this before giving up. 1345 * If we encounter an error, stop immediately. 1346 */ 1347 tries = 0; 1348 req2 = *req; 1349 retry: 1350 generation = curthread->td_generation; 1351 error = SYSCTL_OUT(req, arg1, arg2); 1352 if (error) 1353 return (error); 1354 tries++; 1355 if (generation != curthread->td_generation && tries < 3) { 1356 *req = req2; 1357 goto retry; 1358 } 1359 1360 error = SYSCTL_IN(req, arg1, arg2); 1361 1362 return (error); 1363 } 1364 1365 /* 1366 * Transfer functions to/from kernel space. 1367 * XXX: rather untested at this point 1368 */ 1369 static int 1370 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 1371 { 1372 size_t i = 0; 1373 1374 if (req->oldptr) { 1375 i = l; 1376 if (req->oldlen <= req->oldidx) 1377 i = 0; 1378 else 1379 if (i > req->oldlen - req->oldidx) 1380 i = req->oldlen - req->oldidx; 1381 if (i > 0) 1382 bcopy(p, (char *)req->oldptr + req->oldidx, i); 1383 } 1384 req->oldidx += l; 1385 if (req->oldptr && i != l) 1386 return (ENOMEM); 1387 return (0); 1388 } 1389 1390 static int 1391 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 1392 { 1393 if (!req->newptr) 1394 return (0); 1395 if (req->newlen - req->newidx < l) 1396 return (EINVAL); 1397 bcopy((char *)req->newptr + req->newidx, p, l); 1398 req->newidx += l; 1399 return (0); 1400 } 1401 1402 int 1403 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1404 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags) 1405 { 1406 int error = 0; 1407 struct sysctl_req req; 1408 1409 bzero(&req, sizeof req); 1410 1411 req.td = td; 1412 req.flags = flags; 1413 1414 if (oldlenp) { 1415 req.oldlen = *oldlenp; 1416 } 1417 req.validlen = req.oldlen; 1418 1419 if (old) { 1420 req.oldptr= old; 1421 } 1422 1423 if (new != NULL) { 1424 req.newlen = newlen; 1425 req.newptr = new; 1426 } 1427 1428 req.oldfunc = sysctl_old_kernel; 1429 req.newfunc = sysctl_new_kernel; 1430 req.lock = REQ_UNWIRED; 1431 1432 SYSCTL_SLOCK(); 1433 error = sysctl_root(0, name, namelen, &req); 1434 SYSCTL_SUNLOCK(); 1435 1436 if (req.lock == REQ_WIRED && req.validlen > 0) 1437 vsunlock(req.oldptr, req.validlen); 1438 1439 if (error && error != ENOMEM) 1440 return (error); 1441 1442 if (retval) { 1443 if (req.oldptr && req.oldidx > req.validlen) 1444 *retval = req.validlen; 1445 else 1446 *retval = req.oldidx; 1447 } 1448 return (error); 1449 } 1450 1451 int 1452 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp, 1453 void *new, size_t newlen, size_t *retval, int flags) 1454 { 1455 int oid[CTL_MAXNAME]; 1456 size_t oidlen, plen; 1457 int error; 1458 1459 oid[0] = 0; /* sysctl internal magic */ 1460 oid[1] = 3; /* name2oid */ 1461 oidlen = sizeof(oid); 1462 1463 error = kernel_sysctl(td, oid, 2, oid, &oidlen, 1464 (void *)name, strlen(name), &plen, flags); 1465 if (error) 1466 return (error); 1467 1468 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp, 1469 new, newlen, retval, flags); 1470 return (error); 1471 } 1472 1473 /* 1474 * Transfer function to/from user space. 1475 */ 1476 static int 1477 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1478 { 1479 size_t i, len, origidx; 1480 int error; 1481 1482 origidx = req->oldidx; 1483 req->oldidx += l; 1484 if (req->oldptr == NULL) 1485 return (0); 1486 /* 1487 * If we have not wired the user supplied buffer and we are currently 1488 * holding locks, drop a witness warning, as it's possible that 1489 * write operations to the user page can sleep. 1490 */ 1491 if (req->lock != REQ_WIRED) 1492 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1493 "sysctl_old_user()"); 1494 i = l; 1495 len = req->validlen; 1496 if (len <= origidx) 1497 i = 0; 1498 else { 1499 if (i > len - origidx) 1500 i = len - origidx; 1501 if (req->lock == REQ_WIRED) { 1502 error = copyout_nofault(p, (char *)req->oldptr + 1503 origidx, i); 1504 } else 1505 error = copyout(p, (char *)req->oldptr + origidx, i); 1506 if (error != 0) 1507 return (error); 1508 } 1509 if (i < l) 1510 return (ENOMEM); 1511 return (0); 1512 } 1513 1514 static int 1515 sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1516 { 1517 int error; 1518 1519 if (!req->newptr) 1520 return (0); 1521 if (req->newlen - req->newidx < l) 1522 return (EINVAL); 1523 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1524 "sysctl_new_user()"); 1525 error = copyin((char *)req->newptr + req->newidx, p, l); 1526 req->newidx += l; 1527 return (error); 1528 } 1529 1530 /* 1531 * Wire the user space destination buffer. If set to a value greater than 1532 * zero, the len parameter limits the maximum amount of wired memory. 1533 */ 1534 int 1535 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len) 1536 { 1537 int ret; 1538 size_t wiredlen; 1539 1540 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen; 1541 ret = 0; 1542 if (req->lock != REQ_WIRED && req->oldptr && 1543 req->oldfunc == sysctl_old_user) { 1544 if (wiredlen != 0) { 1545 ret = vslock(req->oldptr, wiredlen); 1546 if (ret != 0) { 1547 if (ret != ENOMEM) 1548 return (ret); 1549 wiredlen = 0; 1550 } 1551 } 1552 req->lock = REQ_WIRED; 1553 req->validlen = wiredlen; 1554 } 1555 return (0); 1556 } 1557 1558 int 1559 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1560 int *nindx, struct sysctl_req *req) 1561 { 1562 struct sysctl_oid_list *lsp; 1563 struct sysctl_oid *oid; 1564 int indx; 1565 1566 SYSCTL_ASSERT_LOCKED(); 1567 lsp = &sysctl__children; 1568 indx = 0; 1569 while (indx < CTL_MAXNAME) { 1570 SLIST_FOREACH(oid, lsp, oid_link) { 1571 if (oid->oid_number == name[indx]) 1572 break; 1573 } 1574 if (oid == NULL) 1575 return (ENOENT); 1576 1577 indx++; 1578 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1579 if (oid->oid_handler != NULL || indx == namelen) { 1580 *noid = oid; 1581 if (nindx != NULL) 1582 *nindx = indx; 1583 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1584 ("%s found DYING node %p", __func__, oid)); 1585 return (0); 1586 } 1587 lsp = SYSCTL_CHILDREN(oid); 1588 } else if (indx == namelen) { 1589 *noid = oid; 1590 if (nindx != NULL) 1591 *nindx = indx; 1592 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1593 ("%s found DYING node %p", __func__, oid)); 1594 return (0); 1595 } else { 1596 return (ENOTDIR); 1597 } 1598 } 1599 return (ENOENT); 1600 } 1601 1602 /* 1603 * Traverse our tree, and find the right node, execute whatever it points 1604 * to, and return the resulting error code. 1605 */ 1606 1607 static int 1608 sysctl_root(SYSCTL_HANDLER_ARGS) 1609 { 1610 struct sysctl_oid *oid; 1611 int error, indx, lvl; 1612 1613 SYSCTL_ASSERT_SLOCKED(); 1614 1615 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1616 if (error) 1617 return (error); 1618 1619 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1620 /* 1621 * You can't call a sysctl when it's a node, but has 1622 * no handler. Inform the user that it's a node. 1623 * The indx may or may not be the same as namelen. 1624 */ 1625 if (oid->oid_handler == NULL) 1626 return (EISDIR); 1627 } 1628 1629 /* Is this sysctl writable? */ 1630 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) 1631 return (EPERM); 1632 1633 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL")); 1634 1635 #ifdef CAPABILITY_MODE 1636 /* 1637 * If the process is in capability mode, then don't permit reading or 1638 * writing unless specifically granted for the node. 1639 */ 1640 if (IN_CAPABILITY_MODE(req->td)) { 1641 if (req->oldptr && !(oid->oid_kind & CTLFLAG_CAPRD)) 1642 return (EPERM); 1643 if (req->newptr && !(oid->oid_kind & CTLFLAG_CAPWR)) 1644 return (EPERM); 1645 } 1646 #endif 1647 1648 /* Is this sysctl sensitive to securelevels? */ 1649 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) { 1650 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE; 1651 error = securelevel_gt(req->td->td_ucred, lvl); 1652 if (error) 1653 return (error); 1654 } 1655 1656 /* Is this sysctl writable by only privileged users? */ 1657 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) { 1658 int priv; 1659 1660 if (oid->oid_kind & CTLFLAG_PRISON) 1661 priv = PRIV_SYSCTL_WRITEJAIL; 1662 #ifdef VIMAGE 1663 else if ((oid->oid_kind & CTLFLAG_VNET) && 1664 prison_owns_vnet(req->td->td_ucred)) 1665 priv = PRIV_SYSCTL_WRITEJAIL; 1666 #endif 1667 else 1668 priv = PRIV_SYSCTL_WRITE; 1669 error = priv_check(req->td, priv); 1670 if (error) 1671 return (error); 1672 } 1673 1674 if (!oid->oid_handler) 1675 return (EINVAL); 1676 1677 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1678 arg1 = (int *)arg1 + indx; 1679 arg2 -= indx; 1680 } else { 1681 arg1 = oid->oid_arg1; 1682 arg2 = oid->oid_arg2; 1683 } 1684 #ifdef MAC 1685 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2, 1686 req); 1687 if (error != 0) 1688 return (error); 1689 #endif 1690 #ifdef VIMAGE 1691 if ((oid->oid_kind & CTLFLAG_VNET) && arg1 != NULL) 1692 arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1); 1693 #endif 1694 error = sysctl_root_handler_locked(oid, arg1, arg2, req); 1695 1696 KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error); 1697 1698 return (error); 1699 } 1700 1701 #ifndef _SYS_SYSPROTO_H_ 1702 struct sysctl_args { 1703 int *name; 1704 u_int namelen; 1705 void *old; 1706 size_t *oldlenp; 1707 void *new; 1708 size_t newlen; 1709 }; 1710 #endif 1711 int 1712 sys___sysctl(struct thread *td, struct sysctl_args *uap) 1713 { 1714 int error, i, name[CTL_MAXNAME]; 1715 size_t j; 1716 1717 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 1718 return (EINVAL); 1719 1720 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 1721 if (error) 1722 return (error); 1723 1724 error = userland_sysctl(td, name, uap->namelen, 1725 uap->old, uap->oldlenp, 0, 1726 uap->new, uap->newlen, &j, 0); 1727 if (error && error != ENOMEM) 1728 return (error); 1729 if (uap->oldlenp) { 1730 i = copyout(&j, uap->oldlenp, sizeof(j)); 1731 if (i) 1732 return (i); 1733 } 1734 return (error); 1735 } 1736 1737 /* 1738 * This is used from various compatibility syscalls too. That's why name 1739 * must be in kernel space. 1740 */ 1741 int 1742 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1743 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval, 1744 int flags) 1745 { 1746 int error = 0, memlocked; 1747 struct sysctl_req req; 1748 1749 bzero(&req, sizeof req); 1750 1751 req.td = td; 1752 req.flags = flags; 1753 1754 if (oldlenp) { 1755 if (inkernel) { 1756 req.oldlen = *oldlenp; 1757 } else { 1758 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 1759 if (error) 1760 return (error); 1761 } 1762 } 1763 req.validlen = req.oldlen; 1764 1765 if (old) { 1766 if (!useracc(old, req.oldlen, VM_PROT_WRITE)) 1767 return (EFAULT); 1768 req.oldptr= old; 1769 } 1770 1771 if (new != NULL) { 1772 if (!useracc(new, newlen, VM_PROT_READ)) 1773 return (EFAULT); 1774 req.newlen = newlen; 1775 req.newptr = new; 1776 } 1777 1778 req.oldfunc = sysctl_old_user; 1779 req.newfunc = sysctl_new_user; 1780 req.lock = REQ_UNWIRED; 1781 1782 #ifdef KTRACE 1783 if (KTRPOINT(curthread, KTR_SYSCTL)) 1784 ktrsysctl(name, namelen); 1785 #endif 1786 1787 if (req.oldlen > PAGE_SIZE) { 1788 memlocked = 1; 1789 sx_xlock(&sysctlmemlock); 1790 } else 1791 memlocked = 0; 1792 CURVNET_SET(TD_TO_VNET(td)); 1793 1794 for (;;) { 1795 req.oldidx = 0; 1796 req.newidx = 0; 1797 SYSCTL_SLOCK(); 1798 error = sysctl_root(0, name, namelen, &req); 1799 SYSCTL_SUNLOCK(); 1800 if (error != EAGAIN) 1801 break; 1802 kern_yield(PRI_USER); 1803 } 1804 1805 CURVNET_RESTORE(); 1806 1807 if (req.lock == REQ_WIRED && req.validlen > 0) 1808 vsunlock(req.oldptr, req.validlen); 1809 if (memlocked) 1810 sx_xunlock(&sysctlmemlock); 1811 1812 if (error && error != ENOMEM) 1813 return (error); 1814 1815 if (retval) { 1816 if (req.oldptr && req.oldidx > req.validlen) 1817 *retval = req.validlen; 1818 else 1819 *retval = req.oldidx; 1820 } 1821 return (error); 1822 } 1823 1824 /* 1825 * Drain into a sysctl struct. The user buffer should be wired if a page 1826 * fault would cause issue. 1827 */ 1828 static int 1829 sbuf_sysctl_drain(void *arg, const char *data, int len) 1830 { 1831 struct sysctl_req *req = arg; 1832 int error; 1833 1834 error = SYSCTL_OUT(req, data, len); 1835 KASSERT(error >= 0, ("Got unexpected negative value %d", error)); 1836 return (error == 0 ? len : -error); 1837 } 1838 1839 struct sbuf * 1840 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length, 1841 struct sysctl_req *req) 1842 { 1843 1844 /* Supply a default buffer size if none given. */ 1845 if (buf == NULL && length == 0) 1846 length = 64; 1847 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN | SBUF_INCLUDENUL); 1848 sbuf_set_drain(s, sbuf_sysctl_drain, req); 1849 return (s); 1850 } 1851