1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Mike Karels at Berkeley Software Design, Inc. 9 * 10 * Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD 11 * project, to make these variables more userfriendly. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)kern_sysctl.c 8.4 (Berkeley) 4/14/94 38 */ 39 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD$"); 42 43 #include "opt_capsicum.h" 44 #include "opt_ktrace.h" 45 46 #include <sys/param.h> 47 #include <sys/fail.h> 48 #include <sys/systm.h> 49 #include <sys/capsicum.h> 50 #include <sys/kernel.h> 51 #include <sys/sysctl.h> 52 #include <sys/malloc.h> 53 #include <sys/priv.h> 54 #include <sys/proc.h> 55 #include <sys/jail.h> 56 #include <sys/lock.h> 57 #include <sys/mutex.h> 58 #include <sys/rmlock.h> 59 #include <sys/sbuf.h> 60 #include <sys/sx.h> 61 #include <sys/sysproto.h> 62 #include <sys/uio.h> 63 #ifdef KTRACE 64 #include <sys/ktrace.h> 65 #endif 66 67 #include <net/vnet.h> 68 69 #include <security/mac/mac_framework.h> 70 71 #include <vm/vm.h> 72 #include <vm/vm_extern.h> 73 74 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic"); 75 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids"); 76 static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer"); 77 78 /* 79 * The sysctllock protects the MIB tree. It also protects sysctl 80 * contexts used with dynamic sysctls. The sysctl_register_oid() and 81 * sysctl_unregister_oid() routines require the sysctllock to already 82 * be held, so the sysctl_wlock() and sysctl_wunlock() routines are 83 * provided for the few places in the kernel which need to use that 84 * API rather than using the dynamic API. Use of the dynamic API is 85 * strongly encouraged for most code. 86 * 87 * The sysctlmemlock is used to limit the amount of user memory wired for 88 * sysctl requests. This is implemented by serializing any userland 89 * sysctl requests larger than a single page via an exclusive lock. 90 */ 91 static struct rmlock sysctllock; 92 static struct sx __exclusive_cache_line sysctlmemlock; 93 94 #define SYSCTL_WLOCK() rm_wlock(&sysctllock) 95 #define SYSCTL_WUNLOCK() rm_wunlock(&sysctllock) 96 #define SYSCTL_RLOCK(tracker) rm_rlock(&sysctllock, (tracker)) 97 #define SYSCTL_RUNLOCK(tracker) rm_runlock(&sysctllock, (tracker)) 98 #define SYSCTL_WLOCKED() rm_wowned(&sysctllock) 99 #define SYSCTL_ASSERT_LOCKED() rm_assert(&sysctllock, RA_LOCKED) 100 #define SYSCTL_ASSERT_WLOCKED() rm_assert(&sysctllock, RA_WLOCKED) 101 #define SYSCTL_ASSERT_RLOCKED() rm_assert(&sysctllock, RA_RLOCKED) 102 #define SYSCTL_INIT() rm_init_flags(&sysctllock, "sysctl lock", \ 103 RM_SLEEPABLE) 104 #define SYSCTL_SLEEP(ch, wmesg, timo) \ 105 rm_sleep(ch, &sysctllock, 0, wmesg, timo) 106 107 static int sysctl_root(SYSCTL_HANDLER_ARGS); 108 109 /* Root list */ 110 struct sysctl_oid_list sysctl__children = SLIST_HEAD_INITIALIZER(&sysctl__children); 111 112 static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, 113 int recurse); 114 static int sysctl_old_kernel(struct sysctl_req *, const void *, size_t); 115 static int sysctl_new_kernel(struct sysctl_req *, void *, size_t); 116 117 static struct sysctl_oid * 118 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list) 119 { 120 struct sysctl_oid *oidp; 121 122 SYSCTL_ASSERT_LOCKED(); 123 SLIST_FOREACH(oidp, list, oid_link) { 124 if (strcmp(oidp->oid_name, name) == 0) { 125 return (oidp); 126 } 127 } 128 return (NULL); 129 } 130 131 /* 132 * Initialization of the MIB tree. 133 * 134 * Order by number in each list. 135 */ 136 void 137 sysctl_wlock(void) 138 { 139 140 SYSCTL_WLOCK(); 141 } 142 143 void 144 sysctl_wunlock(void) 145 { 146 147 SYSCTL_WUNLOCK(); 148 } 149 150 static int 151 sysctl_root_handler_locked(struct sysctl_oid *oid, void *arg1, intmax_t arg2, 152 struct sysctl_req *req, struct rm_priotracker *tracker) 153 { 154 int error; 155 156 if (oid->oid_kind & CTLFLAG_DYN) 157 atomic_add_int(&oid->oid_running, 1); 158 159 if (tracker != NULL) 160 SYSCTL_RUNLOCK(tracker); 161 else 162 SYSCTL_WUNLOCK(); 163 164 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 165 mtx_lock(&Giant); 166 error = oid->oid_handler(oid, arg1, arg2, req); 167 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 168 mtx_unlock(&Giant); 169 170 KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error); 171 172 if (tracker != NULL) 173 SYSCTL_RLOCK(tracker); 174 else 175 SYSCTL_WLOCK(); 176 177 if (oid->oid_kind & CTLFLAG_DYN) { 178 if (atomic_fetchadd_int(&oid->oid_running, -1) == 1 && 179 (oid->oid_kind & CTLFLAG_DYING) != 0) 180 wakeup(&oid->oid_running); 181 } 182 183 return (error); 184 } 185 186 static void 187 sysctl_load_tunable_by_oid_locked(struct sysctl_oid *oidp) 188 { 189 struct sysctl_req req; 190 struct sysctl_oid *curr; 191 char *penv = NULL; 192 char path[96]; 193 ssize_t rem = sizeof(path); 194 ssize_t len; 195 uint8_t data[512] __aligned(sizeof(uint64_t)); 196 int size; 197 int error; 198 199 path[--rem] = 0; 200 201 for (curr = oidp; curr != NULL; curr = SYSCTL_PARENT(curr)) { 202 len = strlen(curr->oid_name); 203 rem -= len; 204 if (curr != oidp) 205 rem -= 1; 206 if (rem < 0) { 207 printf("OID path exceeds %d bytes\n", (int)sizeof(path)); 208 return; 209 } 210 memcpy(path + rem, curr->oid_name, len); 211 if (curr != oidp) 212 path[rem + len] = '.'; 213 } 214 215 memset(&req, 0, sizeof(req)); 216 217 req.td = curthread; 218 req.oldfunc = sysctl_old_kernel; 219 req.newfunc = sysctl_new_kernel; 220 req.lock = REQ_UNWIRED; 221 222 switch (oidp->oid_kind & CTLTYPE) { 223 case CTLTYPE_INT: 224 if (getenv_array(path + rem, data, sizeof(data), &size, 225 sizeof(int), GETENV_SIGNED) == 0) 226 return; 227 req.newlen = size; 228 req.newptr = data; 229 break; 230 case CTLTYPE_UINT: 231 if (getenv_array(path + rem, data, sizeof(data), &size, 232 sizeof(int), GETENV_UNSIGNED) == 0) 233 return; 234 req.newlen = size; 235 req.newptr = data; 236 break; 237 case CTLTYPE_LONG: 238 if (getenv_array(path + rem, data, sizeof(data), &size, 239 sizeof(long), GETENV_SIGNED) == 0) 240 return; 241 req.newlen = size; 242 req.newptr = data; 243 break; 244 case CTLTYPE_ULONG: 245 if (getenv_array(path + rem, data, sizeof(data), &size, 246 sizeof(long), GETENV_UNSIGNED) == 0) 247 return; 248 req.newlen = size; 249 req.newptr = data; 250 break; 251 case CTLTYPE_S8: 252 if (getenv_array(path + rem, data, sizeof(data), &size, 253 sizeof(int8_t), GETENV_SIGNED) == 0) 254 return; 255 req.newlen = size; 256 req.newptr = data; 257 break; 258 case CTLTYPE_S16: 259 if (getenv_array(path + rem, data, sizeof(data), &size, 260 sizeof(int16_t), GETENV_SIGNED) == 0) 261 return; 262 req.newlen = size; 263 req.newptr = data; 264 break; 265 case CTLTYPE_S32: 266 if (getenv_array(path + rem, data, sizeof(data), &size, 267 sizeof(int32_t), GETENV_SIGNED) == 0) 268 return; 269 req.newlen = size; 270 req.newptr = data; 271 break; 272 case CTLTYPE_S64: 273 if (getenv_array(path + rem, data, sizeof(data), &size, 274 sizeof(int64_t), GETENV_SIGNED) == 0) 275 return; 276 req.newlen = size; 277 req.newptr = data; 278 break; 279 case CTLTYPE_U8: 280 if (getenv_array(path + rem, data, sizeof(data), &size, 281 sizeof(uint8_t), GETENV_UNSIGNED) == 0) 282 return; 283 req.newlen = size; 284 req.newptr = data; 285 break; 286 case CTLTYPE_U16: 287 if (getenv_array(path + rem, data, sizeof(data), &size, 288 sizeof(uint16_t), GETENV_UNSIGNED) == 0) 289 return; 290 req.newlen = size; 291 req.newptr = data; 292 break; 293 case CTLTYPE_U32: 294 if (getenv_array(path + rem, data, sizeof(data), &size, 295 sizeof(uint32_t), GETENV_UNSIGNED) == 0) 296 return; 297 req.newlen = size; 298 req.newptr = data; 299 break; 300 case CTLTYPE_U64: 301 if (getenv_array(path + rem, data, sizeof(data), &size, 302 sizeof(uint64_t), GETENV_UNSIGNED) == 0) 303 return; 304 req.newlen = size; 305 req.newptr = data; 306 break; 307 case CTLTYPE_STRING: 308 penv = kern_getenv(path + rem); 309 if (penv == NULL) 310 return; 311 req.newlen = strlen(penv); 312 req.newptr = penv; 313 break; 314 default: 315 return; 316 } 317 error = sysctl_root_handler_locked(oidp, oidp->oid_arg1, 318 oidp->oid_arg2, &req, NULL); 319 if (error != 0) 320 printf("Setting sysctl %s failed: %d\n", path + rem, error); 321 if (penv != NULL) 322 freeenv(penv); 323 } 324 325 static int 326 sbuf_printf_drain(void *arg __unused, const char *data, int len) 327 { 328 329 return (printf("%.*s", len, data)); 330 } 331 332 /* 333 * Locate the path to a given oid. Returns the length of the resulting path, 334 * or -1 if the oid was not found. nodes must have room for CTL_MAXNAME 335 * elements and be NULL initialized. 336 */ 337 static int 338 sysctl_search_oid(struct sysctl_oid **nodes, struct sysctl_oid *needle) 339 { 340 int indx; 341 342 SYSCTL_ASSERT_LOCKED(); 343 indx = 0; 344 while (indx < CTL_MAXNAME && indx >= 0) { 345 if (nodes[indx] == NULL && indx == 0) 346 nodes[indx] = SLIST_FIRST(&sysctl__children); 347 else if (nodes[indx] == NULL) 348 nodes[indx] = SLIST_FIRST(&nodes[indx - 1]->oid_children); 349 else 350 nodes[indx] = SLIST_NEXT(nodes[indx], oid_link); 351 352 if (nodes[indx] == needle) 353 return (indx + 1); 354 355 if (nodes[indx] == NULL) { 356 indx--; 357 continue; 358 } 359 360 if ((nodes[indx]->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 361 indx++; 362 continue; 363 } 364 } 365 return (-1); 366 } 367 368 static void 369 sysctl_warn_reuse(const char *func, struct sysctl_oid *leaf) 370 { 371 struct sysctl_oid *nodes[CTL_MAXNAME]; 372 char buf[128]; 373 struct sbuf sb; 374 int rc, i; 375 376 (void)sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN | SBUF_INCLUDENUL); 377 sbuf_set_drain(&sb, sbuf_printf_drain, NULL); 378 379 sbuf_printf(&sb, "%s: can't re-use a leaf (", __func__); 380 381 memset(nodes, 0, sizeof(nodes)); 382 rc = sysctl_search_oid(nodes, leaf); 383 if (rc > 0) { 384 for (i = 0; i < rc; i++) 385 sbuf_printf(&sb, "%s%.*s", nodes[i]->oid_name, 386 i != (rc - 1), "."); 387 } else { 388 sbuf_printf(&sb, "%s", leaf->oid_name); 389 } 390 sbuf_printf(&sb, ")!\n"); 391 392 (void)sbuf_finish(&sb); 393 } 394 395 #ifdef SYSCTL_DEBUG 396 static int 397 sysctl_reuse_test(SYSCTL_HANDLER_ARGS) 398 { 399 struct rm_priotracker tracker; 400 401 SYSCTL_RLOCK(&tracker); 402 sysctl_warn_reuse(__func__, oidp); 403 SYSCTL_RUNLOCK(&tracker); 404 return (0); 405 } 406 SYSCTL_PROC(_sysctl, 0, reuse_test, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE, 407 0, 0, sysctl_reuse_test, "-", ""); 408 #endif 409 410 void 411 sysctl_register_oid(struct sysctl_oid *oidp) 412 { 413 struct sysctl_oid_list *parent = oidp->oid_parent; 414 struct sysctl_oid *p; 415 struct sysctl_oid *q; 416 int oid_number; 417 int timeout = 2; 418 419 /* 420 * First check if another oid with the same name already 421 * exists in the parent's list. 422 */ 423 SYSCTL_ASSERT_WLOCKED(); 424 p = sysctl_find_oidname(oidp->oid_name, parent); 425 if (p != NULL) { 426 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 427 p->oid_refcnt++; 428 return; 429 } else { 430 sysctl_warn_reuse(__func__, p); 431 return; 432 } 433 } 434 /* get current OID number */ 435 oid_number = oidp->oid_number; 436 437 #if (OID_AUTO >= 0) 438 #error "OID_AUTO is expected to be a negative value" 439 #endif 440 /* 441 * Any negative OID number qualifies as OID_AUTO. Valid OID 442 * numbers should always be positive. 443 * 444 * NOTE: DO NOT change the starting value here, change it in 445 * <sys/sysctl.h>, and make sure it is at least 256 to 446 * accommodate e.g. net.inet.raw as a static sysctl node. 447 */ 448 if (oid_number < 0) { 449 static int newoid; 450 451 /* 452 * By decrementing the next OID number we spend less 453 * time inserting the OIDs into a sorted list. 454 */ 455 if (--newoid < CTL_AUTO_START) 456 newoid = 0x7fffffff; 457 458 oid_number = newoid; 459 } 460 461 /* 462 * Insert the OID into the parent's list sorted by OID number. 463 */ 464 retry: 465 q = NULL; 466 SLIST_FOREACH(p, parent, oid_link) { 467 /* check if the current OID number is in use */ 468 if (oid_number == p->oid_number) { 469 /* get the next valid OID number */ 470 if (oid_number < CTL_AUTO_START || 471 oid_number == 0x7fffffff) { 472 /* wraparound - restart */ 473 oid_number = CTL_AUTO_START; 474 /* don't loop forever */ 475 if (!timeout--) 476 panic("sysctl: Out of OID numbers\n"); 477 goto retry; 478 } else { 479 oid_number++; 480 } 481 } else if (oid_number < p->oid_number) 482 break; 483 q = p; 484 } 485 /* check for non-auto OID number collision */ 486 if (oidp->oid_number >= 0 && oidp->oid_number < CTL_AUTO_START && 487 oid_number >= CTL_AUTO_START) { 488 printf("sysctl: OID number(%d) is already in use for '%s'\n", 489 oidp->oid_number, oidp->oid_name); 490 } 491 /* update the OID number, if any */ 492 oidp->oid_number = oid_number; 493 if (q != NULL) 494 SLIST_INSERT_AFTER(q, oidp, oid_link); 495 else 496 SLIST_INSERT_HEAD(parent, oidp, oid_link); 497 498 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE && 499 #ifdef VIMAGE 500 (oidp->oid_kind & CTLFLAG_VNET) == 0 && 501 #endif 502 (oidp->oid_kind & CTLFLAG_TUN) != 0 && 503 (oidp->oid_kind & CTLFLAG_NOFETCH) == 0) { 504 /* only fetch value once */ 505 oidp->oid_kind |= CTLFLAG_NOFETCH; 506 /* try to fetch value from kernel environment */ 507 sysctl_load_tunable_by_oid_locked(oidp); 508 } 509 } 510 511 void 512 sysctl_register_disabled_oid(struct sysctl_oid *oidp) 513 { 514 515 /* 516 * Mark the leaf as dormant if it's not to be immediately enabled. 517 * We do not disable nodes as they can be shared between modules 518 * and it is always safe to access a node. 519 */ 520 KASSERT((oidp->oid_kind & CTLFLAG_DORMANT) == 0, 521 ("internal flag is set in oid_kind")); 522 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 523 oidp->oid_kind |= CTLFLAG_DORMANT; 524 sysctl_register_oid(oidp); 525 } 526 527 void 528 sysctl_enable_oid(struct sysctl_oid *oidp) 529 { 530 531 SYSCTL_ASSERT_WLOCKED(); 532 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 533 KASSERT((oidp->oid_kind & CTLFLAG_DORMANT) == 0, 534 ("sysctl node is marked as dormant")); 535 return; 536 } 537 KASSERT((oidp->oid_kind & CTLFLAG_DORMANT) != 0, 538 ("enabling already enabled sysctl oid")); 539 oidp->oid_kind &= ~CTLFLAG_DORMANT; 540 } 541 542 void 543 sysctl_unregister_oid(struct sysctl_oid *oidp) 544 { 545 struct sysctl_oid *p; 546 int error; 547 548 SYSCTL_ASSERT_WLOCKED(); 549 error = ENOENT; 550 if (oidp->oid_number == OID_AUTO) { 551 error = EINVAL; 552 } else { 553 SLIST_FOREACH(p, oidp->oid_parent, oid_link) { 554 if (p == oidp) { 555 SLIST_REMOVE(oidp->oid_parent, oidp, 556 sysctl_oid, oid_link); 557 error = 0; 558 break; 559 } 560 } 561 } 562 563 /* 564 * This can happen when a module fails to register and is 565 * being unloaded afterwards. It should not be a panic() 566 * for normal use. 567 */ 568 if (error) 569 printf("%s: failed to unregister sysctl\n", __func__); 570 } 571 572 /* Initialize a new context to keep track of dynamically added sysctls. */ 573 int 574 sysctl_ctx_init(struct sysctl_ctx_list *c) 575 { 576 577 if (c == NULL) { 578 return (EINVAL); 579 } 580 581 /* 582 * No locking here, the caller is responsible for not adding 583 * new nodes to a context until after this function has 584 * returned. 585 */ 586 TAILQ_INIT(c); 587 return (0); 588 } 589 590 /* Free the context, and destroy all dynamic oids registered in this context */ 591 int 592 sysctl_ctx_free(struct sysctl_ctx_list *clist) 593 { 594 struct sysctl_ctx_entry *e, *e1; 595 int error; 596 597 error = 0; 598 /* 599 * First perform a "dry run" to check if it's ok to remove oids. 600 * XXX FIXME 601 * XXX This algorithm is a hack. But I don't know any 602 * XXX better solution for now... 603 */ 604 SYSCTL_WLOCK(); 605 TAILQ_FOREACH(e, clist, link) { 606 error = sysctl_remove_oid_locked(e->entry, 0, 0); 607 if (error) 608 break; 609 } 610 /* 611 * Restore deregistered entries, either from the end, 612 * or from the place where error occurred. 613 * e contains the entry that was not unregistered 614 */ 615 if (error) 616 e1 = TAILQ_PREV(e, sysctl_ctx_list, link); 617 else 618 e1 = TAILQ_LAST(clist, sysctl_ctx_list); 619 while (e1 != NULL) { 620 sysctl_register_oid(e1->entry); 621 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link); 622 } 623 if (error) { 624 SYSCTL_WUNLOCK(); 625 return(EBUSY); 626 } 627 /* Now really delete the entries */ 628 e = TAILQ_FIRST(clist); 629 while (e != NULL) { 630 e1 = TAILQ_NEXT(e, link); 631 error = sysctl_remove_oid_locked(e->entry, 1, 0); 632 if (error) 633 panic("sysctl_remove_oid: corrupt tree, entry: %s", 634 e->entry->oid_name); 635 free(e, M_SYSCTLOID); 636 e = e1; 637 } 638 SYSCTL_WUNLOCK(); 639 return (error); 640 } 641 642 /* Add an entry to the context */ 643 struct sysctl_ctx_entry * 644 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 645 { 646 struct sysctl_ctx_entry *e; 647 648 SYSCTL_ASSERT_WLOCKED(); 649 if (clist == NULL || oidp == NULL) 650 return(NULL); 651 e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK); 652 e->entry = oidp; 653 TAILQ_INSERT_HEAD(clist, e, link); 654 return (e); 655 } 656 657 /* Find an entry in the context */ 658 struct sysctl_ctx_entry * 659 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 660 { 661 struct sysctl_ctx_entry *e; 662 663 SYSCTL_ASSERT_WLOCKED(); 664 if (clist == NULL || oidp == NULL) 665 return(NULL); 666 TAILQ_FOREACH(e, clist, link) { 667 if(e->entry == oidp) 668 return(e); 669 } 670 return (e); 671 } 672 673 /* 674 * Delete an entry from the context. 675 * NOTE: this function doesn't free oidp! You have to remove it 676 * with sysctl_remove_oid(). 677 */ 678 int 679 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 680 { 681 struct sysctl_ctx_entry *e; 682 683 if (clist == NULL || oidp == NULL) 684 return (EINVAL); 685 SYSCTL_WLOCK(); 686 e = sysctl_ctx_entry_find(clist, oidp); 687 if (e != NULL) { 688 TAILQ_REMOVE(clist, e, link); 689 SYSCTL_WUNLOCK(); 690 free(e, M_SYSCTLOID); 691 return (0); 692 } else { 693 SYSCTL_WUNLOCK(); 694 return (ENOENT); 695 } 696 } 697 698 /* 699 * Remove dynamically created sysctl trees. 700 * oidp - top of the tree to be removed 701 * del - if 0 - just deregister, otherwise free up entries as well 702 * recurse - if != 0 traverse the subtree to be deleted 703 */ 704 int 705 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse) 706 { 707 int error; 708 709 SYSCTL_WLOCK(); 710 error = sysctl_remove_oid_locked(oidp, del, recurse); 711 SYSCTL_WUNLOCK(); 712 return (error); 713 } 714 715 int 716 sysctl_remove_name(struct sysctl_oid *parent, const char *name, 717 int del, int recurse) 718 { 719 struct sysctl_oid *p, *tmp; 720 int error; 721 722 error = ENOENT; 723 SYSCTL_WLOCK(); 724 SLIST_FOREACH_SAFE(p, SYSCTL_CHILDREN(parent), oid_link, tmp) { 725 if (strcmp(p->oid_name, name) == 0) { 726 error = sysctl_remove_oid_locked(p, del, recurse); 727 break; 728 } 729 } 730 SYSCTL_WUNLOCK(); 731 732 return (error); 733 } 734 735 736 static int 737 sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse) 738 { 739 struct sysctl_oid *p, *tmp; 740 int error; 741 742 SYSCTL_ASSERT_WLOCKED(); 743 if (oidp == NULL) 744 return(EINVAL); 745 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) { 746 printf("Warning: can't remove non-dynamic nodes (%s)!\n", 747 oidp->oid_name); 748 return (EINVAL); 749 } 750 /* 751 * WARNING: normal method to do this should be through 752 * sysctl_ctx_free(). Use recursing as the last resort 753 * method to purge your sysctl tree of leftovers... 754 * However, if some other code still references these nodes, 755 * it will panic. 756 */ 757 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 758 if (oidp->oid_refcnt == 1) { 759 SLIST_FOREACH_SAFE(p, 760 SYSCTL_CHILDREN(oidp), oid_link, tmp) { 761 if (!recurse) { 762 printf("Warning: failed attempt to " 763 "remove oid %s with child %s\n", 764 oidp->oid_name, p->oid_name); 765 return (ENOTEMPTY); 766 } 767 error = sysctl_remove_oid_locked(p, del, 768 recurse); 769 if (error) 770 return (error); 771 } 772 } 773 } 774 if (oidp->oid_refcnt > 1 ) { 775 oidp->oid_refcnt--; 776 } else { 777 if (oidp->oid_refcnt == 0) { 778 printf("Warning: bad oid_refcnt=%u (%s)!\n", 779 oidp->oid_refcnt, oidp->oid_name); 780 return (EINVAL); 781 } 782 sysctl_unregister_oid(oidp); 783 if (del) { 784 /* 785 * Wait for all threads running the handler to drain. 786 * This preserves the previous behavior when the 787 * sysctl lock was held across a handler invocation, 788 * and is necessary for module unload correctness. 789 */ 790 while (oidp->oid_running > 0) { 791 oidp->oid_kind |= CTLFLAG_DYING; 792 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0); 793 } 794 if (oidp->oid_descr) 795 free(__DECONST(char *, oidp->oid_descr), 796 M_SYSCTLOID); 797 if (oidp->oid_label) 798 free(__DECONST(char *, oidp->oid_label), 799 M_SYSCTLOID); 800 free(__DECONST(char *, oidp->oid_name), M_SYSCTLOID); 801 free(oidp, M_SYSCTLOID); 802 } 803 } 804 return (0); 805 } 806 /* 807 * Create new sysctls at run time. 808 * clist may point to a valid context initialized with sysctl_ctx_init(). 809 */ 810 struct sysctl_oid * 811 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, 812 int number, const char *name, int kind, void *arg1, intmax_t arg2, 813 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr, 814 const char *label) 815 { 816 struct sysctl_oid *oidp; 817 818 /* You have to hook up somewhere.. */ 819 if (parent == NULL) 820 return(NULL); 821 /* Check if the node already exists, otherwise create it */ 822 SYSCTL_WLOCK(); 823 oidp = sysctl_find_oidname(name, parent); 824 if (oidp != NULL) { 825 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 826 oidp->oid_refcnt++; 827 /* Update the context */ 828 if (clist != NULL) 829 sysctl_ctx_entry_add(clist, oidp); 830 SYSCTL_WUNLOCK(); 831 return (oidp); 832 } else { 833 sysctl_warn_reuse(__func__, oidp); 834 SYSCTL_WUNLOCK(); 835 return (NULL); 836 } 837 } 838 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO); 839 oidp->oid_parent = parent; 840 SLIST_INIT(&oidp->oid_children); 841 oidp->oid_number = number; 842 oidp->oid_refcnt = 1; 843 oidp->oid_name = strdup(name, M_SYSCTLOID); 844 oidp->oid_handler = handler; 845 oidp->oid_kind = CTLFLAG_DYN | kind; 846 oidp->oid_arg1 = arg1; 847 oidp->oid_arg2 = arg2; 848 oidp->oid_fmt = fmt; 849 if (descr != NULL) 850 oidp->oid_descr = strdup(descr, M_SYSCTLOID); 851 if (label != NULL) 852 oidp->oid_label = strdup(label, M_SYSCTLOID); 853 /* Update the context, if used */ 854 if (clist != NULL) 855 sysctl_ctx_entry_add(clist, oidp); 856 /* Register this oid */ 857 sysctl_register_oid(oidp); 858 SYSCTL_WUNLOCK(); 859 return (oidp); 860 } 861 862 /* 863 * Rename an existing oid. 864 */ 865 void 866 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) 867 { 868 char *newname; 869 char *oldname; 870 871 newname = strdup(name, M_SYSCTLOID); 872 SYSCTL_WLOCK(); 873 oldname = __DECONST(char *, oidp->oid_name); 874 oidp->oid_name = newname; 875 SYSCTL_WUNLOCK(); 876 free(oldname, M_SYSCTLOID); 877 } 878 879 /* 880 * Reparent an existing oid. 881 */ 882 int 883 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent) 884 { 885 struct sysctl_oid *oidp; 886 887 SYSCTL_WLOCK(); 888 if (oid->oid_parent == parent) { 889 SYSCTL_WUNLOCK(); 890 return (0); 891 } 892 oidp = sysctl_find_oidname(oid->oid_name, parent); 893 if (oidp != NULL) { 894 SYSCTL_WUNLOCK(); 895 return (EEXIST); 896 } 897 sysctl_unregister_oid(oid); 898 oid->oid_parent = parent; 899 oid->oid_number = OID_AUTO; 900 sysctl_register_oid(oid); 901 SYSCTL_WUNLOCK(); 902 return (0); 903 } 904 905 /* 906 * Register the kernel's oids on startup. 907 */ 908 SET_DECLARE(sysctl_set, struct sysctl_oid); 909 910 static void 911 sysctl_register_all(void *arg) 912 { 913 struct sysctl_oid **oidp; 914 915 sx_init(&sysctlmemlock, "sysctl mem"); 916 SYSCTL_INIT(); 917 SYSCTL_WLOCK(); 918 SET_FOREACH(oidp, sysctl_set) 919 sysctl_register_oid(*oidp); 920 SYSCTL_WUNLOCK(); 921 } 922 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_FIRST, sysctl_register_all, NULL); 923 924 /* 925 * "Staff-functions" 926 * 927 * These functions implement a presently undocumented interface 928 * used by the sysctl program to walk the tree, and get the type 929 * so it can print the value. 930 * This interface is under work and consideration, and should probably 931 * be killed with a big axe by the first person who can find the time. 932 * (be aware though, that the proper interface isn't as obvious as it 933 * may seem, there are various conflicting requirements. 934 * 935 * {0,0} printf the entire MIB-tree. 936 * {0,1,...} return the name of the "..." OID. 937 * {0,2,...} return the next OID. 938 * {0,3} return the OID of the name in "new" 939 * {0,4,...} return the kind & format info for the "..." OID. 940 * {0,5,...} return the description of the "..." OID. 941 * {0,6,...} return the aggregation label of the "..." OID. 942 */ 943 944 #ifdef SYSCTL_DEBUG 945 static void 946 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 947 { 948 int k; 949 struct sysctl_oid *oidp; 950 951 SYSCTL_ASSERT_LOCKED(); 952 SLIST_FOREACH(oidp, l, oid_link) { 953 954 for (k=0; k<i; k++) 955 printf(" "); 956 957 printf("%d %s ", oidp->oid_number, oidp->oid_name); 958 959 printf("%c%c", 960 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 961 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 962 963 if (oidp->oid_handler) 964 printf(" *Handler"); 965 966 switch (oidp->oid_kind & CTLTYPE) { 967 case CTLTYPE_NODE: 968 printf(" Node\n"); 969 if (!oidp->oid_handler) { 970 sysctl_sysctl_debug_dump_node( 971 SYSCTL_CHILDREN(oidp), i + 2); 972 } 973 break; 974 case CTLTYPE_INT: printf(" Int\n"); break; 975 case CTLTYPE_UINT: printf(" u_int\n"); break; 976 case CTLTYPE_LONG: printf(" Long\n"); break; 977 case CTLTYPE_ULONG: printf(" u_long\n"); break; 978 case CTLTYPE_STRING: printf(" String\n"); break; 979 case CTLTYPE_S8: printf(" int8_t\n"); break; 980 case CTLTYPE_S16: printf(" int16_t\n"); break; 981 case CTLTYPE_S32: printf(" int32_t\n"); break; 982 case CTLTYPE_S64: printf(" int64_t\n"); break; 983 case CTLTYPE_U8: printf(" uint8_t\n"); break; 984 case CTLTYPE_U16: printf(" uint16_t\n"); break; 985 case CTLTYPE_U32: printf(" uint32_t\n"); break; 986 case CTLTYPE_U64: printf(" uint64_t\n"); break; 987 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break; 988 default: printf("\n"); 989 } 990 991 } 992 } 993 994 static int 995 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 996 { 997 struct rm_priotracker tracker; 998 int error; 999 1000 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 1001 if (error) 1002 return (error); 1003 SYSCTL_RLOCK(&tracker); 1004 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 1005 SYSCTL_RUNLOCK(&tracker); 1006 return (ENOENT); 1007 } 1008 1009 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE, 1010 0, 0, sysctl_sysctl_debug, "-", ""); 1011 #endif 1012 1013 static int 1014 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 1015 { 1016 int *name = (int *) arg1; 1017 u_int namelen = arg2; 1018 int error = 0; 1019 struct sysctl_oid *oid; 1020 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 1021 struct rm_priotracker tracker; 1022 char buf[10]; 1023 1024 SYSCTL_RLOCK(&tracker); 1025 while (namelen) { 1026 if (!lsp) { 1027 snprintf(buf,sizeof(buf),"%d",*name); 1028 if (req->oldidx) 1029 error = SYSCTL_OUT(req, ".", 1); 1030 if (!error) 1031 error = SYSCTL_OUT(req, buf, strlen(buf)); 1032 if (error) 1033 goto out; 1034 namelen--; 1035 name++; 1036 continue; 1037 } 1038 lsp2 = NULL; 1039 SLIST_FOREACH(oid, lsp, oid_link) { 1040 if (oid->oid_number != *name) 1041 continue; 1042 1043 if (req->oldidx) 1044 error = SYSCTL_OUT(req, ".", 1); 1045 if (!error) 1046 error = SYSCTL_OUT(req, oid->oid_name, 1047 strlen(oid->oid_name)); 1048 if (error) 1049 goto out; 1050 1051 namelen--; 1052 name++; 1053 1054 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 1055 break; 1056 1057 if (oid->oid_handler) 1058 break; 1059 1060 lsp2 = SYSCTL_CHILDREN(oid); 1061 break; 1062 } 1063 lsp = lsp2; 1064 } 1065 error = SYSCTL_OUT(req, "", 1); 1066 out: 1067 SYSCTL_RUNLOCK(&tracker); 1068 return (error); 1069 } 1070 1071 /* 1072 * XXXRW/JA: Shouldn't return name data for nodes that we don't permit in 1073 * capability mode. 1074 */ 1075 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, 1076 sysctl_sysctl_name, ""); 1077 1078 static int 1079 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 1080 int *next, int *len, int level, struct sysctl_oid **oidpp) 1081 { 1082 struct sysctl_oid *oidp; 1083 1084 SYSCTL_ASSERT_LOCKED(); 1085 *len = level; 1086 SLIST_FOREACH(oidp, lsp, oid_link) { 1087 *next = oidp->oid_number; 1088 *oidpp = oidp; 1089 1090 if ((oidp->oid_kind & (CTLFLAG_SKIP | CTLFLAG_DORMANT)) != 0) 1091 continue; 1092 1093 if (!namelen) { 1094 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 1095 return (0); 1096 if (oidp->oid_handler) 1097 /* We really should call the handler here...*/ 1098 return (0); 1099 lsp = SYSCTL_CHILDREN(oidp); 1100 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 1101 len, level+1, oidpp)) 1102 return (0); 1103 goto emptynode; 1104 } 1105 1106 if (oidp->oid_number < *name) 1107 continue; 1108 1109 if (oidp->oid_number > *name) { 1110 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 1111 return (0); 1112 if (oidp->oid_handler) 1113 return (0); 1114 lsp = SYSCTL_CHILDREN(oidp); 1115 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 1116 next+1, len, level+1, oidpp)) 1117 return (0); 1118 goto next; 1119 } 1120 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 1121 continue; 1122 1123 if (oidp->oid_handler) 1124 continue; 1125 1126 lsp = SYSCTL_CHILDREN(oidp); 1127 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 1128 len, level+1, oidpp)) 1129 return (0); 1130 next: 1131 namelen = 1; 1132 emptynode: 1133 *len = level; 1134 } 1135 return (1); 1136 } 1137 1138 static int 1139 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 1140 { 1141 int *name = (int *) arg1; 1142 u_int namelen = arg2; 1143 int i, j, error; 1144 struct sysctl_oid *oid; 1145 struct sysctl_oid_list *lsp = &sysctl__children; 1146 struct rm_priotracker tracker; 1147 int newoid[CTL_MAXNAME]; 1148 1149 SYSCTL_RLOCK(&tracker); 1150 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 1151 SYSCTL_RUNLOCK(&tracker); 1152 if (i) 1153 return (ENOENT); 1154 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 1155 return (error); 1156 } 1157 1158 /* 1159 * XXXRW/JA: Shouldn't return next data for nodes that we don't permit in 1160 * capability mode. 1161 */ 1162 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, 1163 sysctl_sysctl_next, ""); 1164 1165 static int 1166 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) 1167 { 1168 struct sysctl_oid *oidp; 1169 struct sysctl_oid_list *lsp = &sysctl__children; 1170 char *p; 1171 1172 SYSCTL_ASSERT_LOCKED(); 1173 1174 for (*len = 0; *len < CTL_MAXNAME;) { 1175 p = strsep(&name, "."); 1176 1177 oidp = SLIST_FIRST(lsp); 1178 for (;; oidp = SLIST_NEXT(oidp, oid_link)) { 1179 if (oidp == NULL) 1180 return (ENOENT); 1181 if (strcmp(p, oidp->oid_name) == 0) 1182 break; 1183 } 1184 *oid++ = oidp->oid_number; 1185 (*len)++; 1186 1187 if (name == NULL || *name == '\0') { 1188 if (oidpp) 1189 *oidpp = oidp; 1190 return (0); 1191 } 1192 1193 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 1194 break; 1195 1196 if (oidp->oid_handler) 1197 break; 1198 1199 lsp = SYSCTL_CHILDREN(oidp); 1200 } 1201 return (ENOENT); 1202 } 1203 1204 static int 1205 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 1206 { 1207 char *p; 1208 int error, oid[CTL_MAXNAME], len = 0; 1209 struct sysctl_oid *op = NULL; 1210 struct rm_priotracker tracker; 1211 char buf[32]; 1212 1213 if (!req->newlen) 1214 return (ENOENT); 1215 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 1216 return (ENAMETOOLONG); 1217 1218 p = buf; 1219 if (req->newlen >= sizeof(buf)) 1220 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK); 1221 1222 error = SYSCTL_IN(req, p, req->newlen); 1223 if (error) { 1224 if (p != buf) 1225 free(p, M_SYSCTL); 1226 return (error); 1227 } 1228 1229 p [req->newlen] = '\0'; 1230 1231 SYSCTL_RLOCK(&tracker); 1232 error = name2oid(p, oid, &len, &op); 1233 SYSCTL_RUNLOCK(&tracker); 1234 1235 if (p != buf) 1236 free(p, M_SYSCTL); 1237 1238 if (error) 1239 return (error); 1240 1241 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 1242 return (error); 1243 } 1244 1245 /* 1246 * XXXRW/JA: Shouldn't return name2oid data for nodes that we don't permit in 1247 * capability mode. 1248 */ 1249 SYSCTL_PROC(_sysctl, 3, name2oid, 1250 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE 1251 | CTLFLAG_CAPRW, 0, 0, sysctl_sysctl_name2oid, "I", ""); 1252 1253 static int 1254 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 1255 { 1256 struct sysctl_oid *oid; 1257 struct rm_priotracker tracker; 1258 int error; 1259 1260 SYSCTL_RLOCK(&tracker); 1261 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 1262 if (error) 1263 goto out; 1264 1265 if (oid->oid_fmt == NULL) { 1266 error = ENOENT; 1267 goto out; 1268 } 1269 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 1270 if (error) 1271 goto out; 1272 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 1273 out: 1274 SYSCTL_RUNLOCK(&tracker); 1275 return (error); 1276 } 1277 1278 1279 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD, 1280 sysctl_sysctl_oidfmt, ""); 1281 1282 static int 1283 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 1284 { 1285 struct sysctl_oid *oid; 1286 struct rm_priotracker tracker; 1287 int error; 1288 1289 SYSCTL_RLOCK(&tracker); 1290 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 1291 if (error) 1292 goto out; 1293 1294 if (oid->oid_descr == NULL) { 1295 error = ENOENT; 1296 goto out; 1297 } 1298 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 1299 out: 1300 SYSCTL_RUNLOCK(&tracker); 1301 return (error); 1302 } 1303 1304 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD, 1305 sysctl_sysctl_oiddescr, ""); 1306 1307 static int 1308 sysctl_sysctl_oidlabel(SYSCTL_HANDLER_ARGS) 1309 { 1310 struct sysctl_oid *oid; 1311 struct rm_priotracker tracker; 1312 int error; 1313 1314 SYSCTL_RLOCK(&tracker); 1315 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 1316 if (error) 1317 goto out; 1318 1319 if (oid->oid_label == NULL) { 1320 error = ENOENT; 1321 goto out; 1322 } 1323 error = SYSCTL_OUT(req, oid->oid_label, strlen(oid->oid_label) + 1); 1324 out: 1325 SYSCTL_RUNLOCK(&tracker); 1326 return (error); 1327 } 1328 1329 static SYSCTL_NODE(_sysctl, 6, oidlabel, 1330 CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, sysctl_sysctl_oidlabel, ""); 1331 1332 /* 1333 * Default "handler" functions. 1334 */ 1335 1336 /* 1337 * Handle a bool. 1338 * Two cases: 1339 * a variable: point arg1 at it. 1340 * a constant: pass it in arg2. 1341 */ 1342 1343 int 1344 sysctl_handle_bool(SYSCTL_HANDLER_ARGS) 1345 { 1346 uint8_t temp; 1347 int error; 1348 1349 /* 1350 * Attempt to get a coherent snapshot by making a copy of the data. 1351 */ 1352 if (arg1) 1353 temp = *(bool *)arg1 ? 1 : 0; 1354 else 1355 temp = arg2 ? 1 : 0; 1356 1357 error = SYSCTL_OUT(req, &temp, sizeof(temp)); 1358 if (error || !req->newptr) 1359 return (error); 1360 1361 if (!arg1) 1362 error = EPERM; 1363 else { 1364 error = SYSCTL_IN(req, &temp, sizeof(temp)); 1365 if (!error) 1366 *(bool *)arg1 = temp ? 1 : 0; 1367 } 1368 return (error); 1369 } 1370 1371 /* 1372 * Handle an int8_t, signed or unsigned. 1373 * Two cases: 1374 * a variable: point arg1 at it. 1375 * a constant: pass it in arg2. 1376 */ 1377 1378 int 1379 sysctl_handle_8(SYSCTL_HANDLER_ARGS) 1380 { 1381 int8_t tmpout; 1382 int error = 0; 1383 1384 /* 1385 * Attempt to get a coherent snapshot by making a copy of the data. 1386 */ 1387 if (arg1) 1388 tmpout = *(int8_t *)arg1; 1389 else 1390 tmpout = arg2; 1391 error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout)); 1392 1393 if (error || !req->newptr) 1394 return (error); 1395 1396 if (!arg1) 1397 error = EPERM; 1398 else 1399 error = SYSCTL_IN(req, arg1, sizeof(tmpout)); 1400 return (error); 1401 } 1402 1403 /* 1404 * Handle an int16_t, signed or unsigned. 1405 * Two cases: 1406 * a variable: point arg1 at it. 1407 * a constant: pass it in arg2. 1408 */ 1409 1410 int 1411 sysctl_handle_16(SYSCTL_HANDLER_ARGS) 1412 { 1413 int16_t tmpout; 1414 int error = 0; 1415 1416 /* 1417 * Attempt to get a coherent snapshot by making a copy of the data. 1418 */ 1419 if (arg1) 1420 tmpout = *(int16_t *)arg1; 1421 else 1422 tmpout = arg2; 1423 error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout)); 1424 1425 if (error || !req->newptr) 1426 return (error); 1427 1428 if (!arg1) 1429 error = EPERM; 1430 else 1431 error = SYSCTL_IN(req, arg1, sizeof(tmpout)); 1432 return (error); 1433 } 1434 1435 /* 1436 * Handle an int32_t, signed or unsigned. 1437 * Two cases: 1438 * a variable: point arg1 at it. 1439 * a constant: pass it in arg2. 1440 */ 1441 1442 int 1443 sysctl_handle_32(SYSCTL_HANDLER_ARGS) 1444 { 1445 int32_t tmpout; 1446 int error = 0; 1447 1448 /* 1449 * Attempt to get a coherent snapshot by making a copy of the data. 1450 */ 1451 if (arg1) 1452 tmpout = *(int32_t *)arg1; 1453 else 1454 tmpout = arg2; 1455 error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout)); 1456 1457 if (error || !req->newptr) 1458 return (error); 1459 1460 if (!arg1) 1461 error = EPERM; 1462 else 1463 error = SYSCTL_IN(req, arg1, sizeof(tmpout)); 1464 return (error); 1465 } 1466 1467 /* 1468 * Handle an int, signed or unsigned. 1469 * Two cases: 1470 * a variable: point arg1 at it. 1471 * a constant: pass it in arg2. 1472 */ 1473 1474 int 1475 sysctl_handle_int(SYSCTL_HANDLER_ARGS) 1476 { 1477 int tmpout, error = 0; 1478 1479 /* 1480 * Attempt to get a coherent snapshot by making a copy of the data. 1481 */ 1482 if (arg1) 1483 tmpout = *(int *)arg1; 1484 else 1485 tmpout = arg2; 1486 error = SYSCTL_OUT(req, &tmpout, sizeof(int)); 1487 1488 if (error || !req->newptr) 1489 return (error); 1490 1491 if (!arg1) 1492 error = EPERM; 1493 else 1494 error = SYSCTL_IN(req, arg1, sizeof(int)); 1495 return (error); 1496 } 1497 1498 /* 1499 * Based on on sysctl_handle_int() convert milliseconds into ticks. 1500 * Note: this is used by TCP. 1501 */ 1502 1503 int 1504 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) 1505 { 1506 int error, s, tt; 1507 1508 tt = *(int *)arg1; 1509 s = (int)((int64_t)tt * 1000 / hz); 1510 1511 error = sysctl_handle_int(oidp, &s, 0, req); 1512 if (error || !req->newptr) 1513 return (error); 1514 1515 tt = (int)((int64_t)s * hz / 1000); 1516 if (tt < 1) 1517 return (EINVAL); 1518 1519 *(int *)arg1 = tt; 1520 return (0); 1521 } 1522 1523 1524 /* 1525 * Handle a long, signed or unsigned. 1526 * Two cases: 1527 * a variable: point arg1 at it. 1528 * a constant: pass it in arg2. 1529 */ 1530 1531 int 1532 sysctl_handle_long(SYSCTL_HANDLER_ARGS) 1533 { 1534 int error = 0; 1535 long tmplong; 1536 #ifdef SCTL_MASK32 1537 int tmpint; 1538 #endif 1539 1540 /* 1541 * Attempt to get a coherent snapshot by making a copy of the data. 1542 */ 1543 if (arg1) 1544 tmplong = *(long *)arg1; 1545 else 1546 tmplong = arg2; 1547 #ifdef SCTL_MASK32 1548 if (req->flags & SCTL_MASK32) { 1549 tmpint = tmplong; 1550 error = SYSCTL_OUT(req, &tmpint, sizeof(int)); 1551 } else 1552 #endif 1553 error = SYSCTL_OUT(req, &tmplong, sizeof(long)); 1554 1555 if (error || !req->newptr) 1556 return (error); 1557 1558 if (!arg1) 1559 error = EPERM; 1560 #ifdef SCTL_MASK32 1561 else if (req->flags & SCTL_MASK32) { 1562 error = SYSCTL_IN(req, &tmpint, sizeof(int)); 1563 *(long *)arg1 = (long)tmpint; 1564 } 1565 #endif 1566 else 1567 error = SYSCTL_IN(req, arg1, sizeof(long)); 1568 return (error); 1569 } 1570 1571 /* 1572 * Handle a 64 bit int, signed or unsigned. 1573 * Two cases: 1574 * a variable: point arg1 at it. 1575 * a constant: pass it in arg2. 1576 */ 1577 int 1578 sysctl_handle_64(SYSCTL_HANDLER_ARGS) 1579 { 1580 int error = 0; 1581 uint64_t tmpout; 1582 1583 /* 1584 * Attempt to get a coherent snapshot by making a copy of the data. 1585 */ 1586 if (arg1) 1587 tmpout = *(uint64_t *)arg1; 1588 else 1589 tmpout = arg2; 1590 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t)); 1591 1592 if (error || !req->newptr) 1593 return (error); 1594 1595 if (!arg1) 1596 error = EPERM; 1597 else 1598 error = SYSCTL_IN(req, arg1, sizeof(uint64_t)); 1599 return (error); 1600 } 1601 1602 /* 1603 * Handle our generic '\0' terminated 'C' string. 1604 * Two cases: 1605 * a variable string: point arg1 at it, arg2 is max length. 1606 * a constant string: point arg1 at it, arg2 is zero. 1607 */ 1608 1609 int 1610 sysctl_handle_string(SYSCTL_HANDLER_ARGS) 1611 { 1612 size_t outlen; 1613 int error = 0, ro_string = 0; 1614 1615 /* 1616 * A zero-length buffer indicates a fixed size read-only 1617 * string: 1618 */ 1619 if (arg2 == 0) { 1620 arg2 = strlen((char *)arg1) + 1; 1621 ro_string = 1; 1622 } 1623 1624 if (req->oldptr != NULL) { 1625 char *tmparg; 1626 1627 if (ro_string) { 1628 tmparg = arg1; 1629 } else { 1630 /* try to make a coherent snapshot of the string */ 1631 tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK); 1632 memcpy(tmparg, arg1, arg2); 1633 } 1634 1635 outlen = strnlen(tmparg, arg2 - 1) + 1; 1636 error = SYSCTL_OUT(req, tmparg, outlen); 1637 1638 if (!ro_string) 1639 free(tmparg, M_SYSCTLTMP); 1640 } else { 1641 outlen = strnlen((char *)arg1, arg2 - 1) + 1; 1642 error = SYSCTL_OUT(req, NULL, outlen); 1643 } 1644 if (error || !req->newptr) 1645 return (error); 1646 1647 if ((req->newlen - req->newidx) >= arg2) { 1648 error = EINVAL; 1649 } else { 1650 arg2 = (req->newlen - req->newidx); 1651 error = SYSCTL_IN(req, arg1, arg2); 1652 ((char *)arg1)[arg2] = '\0'; 1653 } 1654 return (error); 1655 } 1656 1657 /* 1658 * Handle any kind of opaque data. 1659 * arg1 points to it, arg2 is the size. 1660 */ 1661 1662 int 1663 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 1664 { 1665 int error, tries; 1666 u_int generation; 1667 struct sysctl_req req2; 1668 1669 /* 1670 * Attempt to get a coherent snapshot, by using the thread 1671 * pre-emption counter updated from within mi_switch() to 1672 * determine if we were pre-empted during a bcopy() or 1673 * copyout(). Make 3 attempts at doing this before giving up. 1674 * If we encounter an error, stop immediately. 1675 */ 1676 tries = 0; 1677 req2 = *req; 1678 retry: 1679 generation = curthread->td_generation; 1680 error = SYSCTL_OUT(req, arg1, arg2); 1681 if (error) 1682 return (error); 1683 tries++; 1684 if (generation != curthread->td_generation && tries < 3) { 1685 *req = req2; 1686 goto retry; 1687 } 1688 1689 error = SYSCTL_IN(req, arg1, arg2); 1690 1691 return (error); 1692 } 1693 1694 /* 1695 * Transfer functions to/from kernel space. 1696 * XXX: rather untested at this point 1697 */ 1698 static int 1699 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 1700 { 1701 size_t i = 0; 1702 1703 if (req->oldptr) { 1704 i = l; 1705 if (req->oldlen <= req->oldidx) 1706 i = 0; 1707 else 1708 if (i > req->oldlen - req->oldidx) 1709 i = req->oldlen - req->oldidx; 1710 if (i > 0) 1711 bcopy(p, (char *)req->oldptr + req->oldidx, i); 1712 } 1713 req->oldidx += l; 1714 if (req->oldptr && i != l) 1715 return (ENOMEM); 1716 return (0); 1717 } 1718 1719 static int 1720 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 1721 { 1722 if (!req->newptr) 1723 return (0); 1724 if (req->newlen - req->newidx < l) 1725 return (EINVAL); 1726 bcopy((char *)req->newptr + req->newidx, p, l); 1727 req->newidx += l; 1728 return (0); 1729 } 1730 1731 int 1732 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1733 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags) 1734 { 1735 int error = 0; 1736 struct sysctl_req req; 1737 1738 bzero(&req, sizeof req); 1739 1740 req.td = td; 1741 req.flags = flags; 1742 1743 if (oldlenp) { 1744 req.oldlen = *oldlenp; 1745 } 1746 req.validlen = req.oldlen; 1747 1748 if (old) { 1749 req.oldptr= old; 1750 } 1751 1752 if (new != NULL) { 1753 req.newlen = newlen; 1754 req.newptr = new; 1755 } 1756 1757 req.oldfunc = sysctl_old_kernel; 1758 req.newfunc = sysctl_new_kernel; 1759 req.lock = REQ_UNWIRED; 1760 1761 error = sysctl_root(0, name, namelen, &req); 1762 1763 if (req.lock == REQ_WIRED && req.validlen > 0) 1764 vsunlock(req.oldptr, req.validlen); 1765 1766 if (error && error != ENOMEM) 1767 return (error); 1768 1769 if (retval) { 1770 if (req.oldptr && req.oldidx > req.validlen) 1771 *retval = req.validlen; 1772 else 1773 *retval = req.oldidx; 1774 } 1775 return (error); 1776 } 1777 1778 int 1779 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp, 1780 void *new, size_t newlen, size_t *retval, int flags) 1781 { 1782 int oid[CTL_MAXNAME]; 1783 size_t oidlen, plen; 1784 int error; 1785 1786 oid[0] = 0; /* sysctl internal magic */ 1787 oid[1] = 3; /* name2oid */ 1788 oidlen = sizeof(oid); 1789 1790 error = kernel_sysctl(td, oid, 2, oid, &oidlen, 1791 (void *)name, strlen(name), &plen, flags); 1792 if (error) 1793 return (error); 1794 1795 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp, 1796 new, newlen, retval, flags); 1797 return (error); 1798 } 1799 1800 /* 1801 * Transfer function to/from user space. 1802 */ 1803 static int 1804 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1805 { 1806 size_t i, len, origidx; 1807 int error; 1808 1809 origidx = req->oldidx; 1810 req->oldidx += l; 1811 if (req->oldptr == NULL) 1812 return (0); 1813 /* 1814 * If we have not wired the user supplied buffer and we are currently 1815 * holding locks, drop a witness warning, as it's possible that 1816 * write operations to the user page can sleep. 1817 */ 1818 if (req->lock != REQ_WIRED) 1819 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1820 "sysctl_old_user()"); 1821 i = l; 1822 len = req->validlen; 1823 if (len <= origidx) 1824 i = 0; 1825 else { 1826 if (i > len - origidx) 1827 i = len - origidx; 1828 if (req->lock == REQ_WIRED) { 1829 error = copyout_nofault(p, (char *)req->oldptr + 1830 origidx, i); 1831 } else 1832 error = copyout(p, (char *)req->oldptr + origidx, i); 1833 if (error != 0) 1834 return (error); 1835 } 1836 if (i < l) 1837 return (ENOMEM); 1838 return (0); 1839 } 1840 1841 static int 1842 sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1843 { 1844 int error; 1845 1846 if (!req->newptr) 1847 return (0); 1848 if (req->newlen - req->newidx < l) 1849 return (EINVAL); 1850 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1851 "sysctl_new_user()"); 1852 error = copyin((char *)req->newptr + req->newidx, p, l); 1853 req->newidx += l; 1854 return (error); 1855 } 1856 1857 /* 1858 * Wire the user space destination buffer. If set to a value greater than 1859 * zero, the len parameter limits the maximum amount of wired memory. 1860 */ 1861 int 1862 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len) 1863 { 1864 int ret; 1865 size_t wiredlen; 1866 1867 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen; 1868 ret = 0; 1869 if (req->lock != REQ_WIRED && req->oldptr && 1870 req->oldfunc == sysctl_old_user) { 1871 if (wiredlen != 0) { 1872 ret = vslock(req->oldptr, wiredlen); 1873 if (ret != 0) { 1874 if (ret != ENOMEM) 1875 return (ret); 1876 wiredlen = 0; 1877 } 1878 } 1879 req->lock = REQ_WIRED; 1880 req->validlen = wiredlen; 1881 } 1882 return (0); 1883 } 1884 1885 int 1886 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1887 int *nindx, struct sysctl_req *req) 1888 { 1889 struct sysctl_oid_list *lsp; 1890 struct sysctl_oid *oid; 1891 int indx; 1892 1893 SYSCTL_ASSERT_LOCKED(); 1894 lsp = &sysctl__children; 1895 indx = 0; 1896 while (indx < CTL_MAXNAME) { 1897 SLIST_FOREACH(oid, lsp, oid_link) { 1898 if (oid->oid_number == name[indx]) 1899 break; 1900 } 1901 if (oid == NULL) 1902 return (ENOENT); 1903 1904 indx++; 1905 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1906 if (oid->oid_handler != NULL || indx == namelen) { 1907 *noid = oid; 1908 if (nindx != NULL) 1909 *nindx = indx; 1910 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1911 ("%s found DYING node %p", __func__, oid)); 1912 return (0); 1913 } 1914 lsp = SYSCTL_CHILDREN(oid); 1915 } else if (indx == namelen) { 1916 if ((oid->oid_kind & CTLFLAG_DORMANT) != 0) 1917 return (ENOENT); 1918 *noid = oid; 1919 if (nindx != NULL) 1920 *nindx = indx; 1921 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1922 ("%s found DYING node %p", __func__, oid)); 1923 return (0); 1924 } else { 1925 return (ENOTDIR); 1926 } 1927 } 1928 return (ENOENT); 1929 } 1930 1931 /* 1932 * Traverse our tree, and find the right node, execute whatever it points 1933 * to, and return the resulting error code. 1934 */ 1935 1936 static int 1937 sysctl_root(SYSCTL_HANDLER_ARGS) 1938 { 1939 struct sysctl_oid *oid; 1940 struct rm_priotracker tracker; 1941 int error, indx, lvl; 1942 1943 SYSCTL_RLOCK(&tracker); 1944 1945 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1946 if (error) 1947 goto out; 1948 1949 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1950 /* 1951 * You can't call a sysctl when it's a node, but has 1952 * no handler. Inform the user that it's a node. 1953 * The indx may or may not be the same as namelen. 1954 */ 1955 if (oid->oid_handler == NULL) { 1956 error = EISDIR; 1957 goto out; 1958 } 1959 } 1960 1961 /* Is this sysctl writable? */ 1962 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) { 1963 error = EPERM; 1964 goto out; 1965 } 1966 1967 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL")); 1968 1969 #ifdef CAPABILITY_MODE 1970 /* 1971 * If the process is in capability mode, then don't permit reading or 1972 * writing unless specifically granted for the node. 1973 */ 1974 if (IN_CAPABILITY_MODE(req->td)) { 1975 if ((req->oldptr && !(oid->oid_kind & CTLFLAG_CAPRD)) || 1976 (req->newptr && !(oid->oid_kind & CTLFLAG_CAPWR))) { 1977 error = EPERM; 1978 goto out; 1979 } 1980 } 1981 #endif 1982 1983 /* Is this sysctl sensitive to securelevels? */ 1984 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) { 1985 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE; 1986 error = securelevel_gt(req->td->td_ucred, lvl); 1987 if (error) 1988 goto out; 1989 } 1990 1991 /* Is this sysctl writable by only privileged users? */ 1992 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) { 1993 int priv; 1994 1995 if (oid->oid_kind & CTLFLAG_PRISON) 1996 priv = PRIV_SYSCTL_WRITEJAIL; 1997 #ifdef VIMAGE 1998 else if ((oid->oid_kind & CTLFLAG_VNET) && 1999 prison_owns_vnet(req->td->td_ucred)) 2000 priv = PRIV_SYSCTL_WRITEJAIL; 2001 #endif 2002 else 2003 priv = PRIV_SYSCTL_WRITE; 2004 error = priv_check(req->td, priv); 2005 if (error) 2006 goto out; 2007 } 2008 2009 if (!oid->oid_handler) { 2010 error = EINVAL; 2011 goto out; 2012 } 2013 2014 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 2015 arg1 = (int *)arg1 + indx; 2016 arg2 -= indx; 2017 } else { 2018 arg1 = oid->oid_arg1; 2019 arg2 = oid->oid_arg2; 2020 } 2021 #ifdef MAC 2022 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2, 2023 req); 2024 if (error != 0) 2025 goto out; 2026 #endif 2027 #ifdef VIMAGE 2028 if ((oid->oid_kind & CTLFLAG_VNET) && arg1 != NULL) 2029 arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1); 2030 #endif 2031 error = sysctl_root_handler_locked(oid, arg1, arg2, req, &tracker); 2032 2033 out: 2034 SYSCTL_RUNLOCK(&tracker); 2035 return (error); 2036 } 2037 2038 #ifndef _SYS_SYSPROTO_H_ 2039 struct sysctl_args { 2040 int *name; 2041 u_int namelen; 2042 void *old; 2043 size_t *oldlenp; 2044 void *new; 2045 size_t newlen; 2046 }; 2047 #endif 2048 int 2049 sys___sysctl(struct thread *td, struct sysctl_args *uap) 2050 { 2051 int error, i, name[CTL_MAXNAME]; 2052 size_t j; 2053 2054 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 2055 return (EINVAL); 2056 2057 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 2058 if (error) 2059 return (error); 2060 2061 error = userland_sysctl(td, name, uap->namelen, 2062 uap->old, uap->oldlenp, 0, 2063 uap->new, uap->newlen, &j, 0); 2064 if (error && error != ENOMEM) 2065 return (error); 2066 if (uap->oldlenp) { 2067 i = copyout(&j, uap->oldlenp, sizeof(j)); 2068 if (i) 2069 return (i); 2070 } 2071 return (error); 2072 } 2073 2074 /* 2075 * This is used from various compatibility syscalls too. That's why name 2076 * must be in kernel space. 2077 */ 2078 int 2079 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old, 2080 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval, 2081 int flags) 2082 { 2083 int error = 0, memlocked; 2084 struct sysctl_req req; 2085 2086 bzero(&req, sizeof req); 2087 2088 req.td = td; 2089 req.flags = flags; 2090 2091 if (oldlenp) { 2092 if (inkernel) { 2093 req.oldlen = *oldlenp; 2094 } else { 2095 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 2096 if (error) 2097 return (error); 2098 } 2099 } 2100 req.validlen = req.oldlen; 2101 req.oldptr = old; 2102 2103 if (new != NULL) { 2104 req.newlen = newlen; 2105 req.newptr = new; 2106 } 2107 2108 req.oldfunc = sysctl_old_user; 2109 req.newfunc = sysctl_new_user; 2110 req.lock = REQ_UNWIRED; 2111 2112 #ifdef KTRACE 2113 if (KTRPOINT(curthread, KTR_SYSCTL)) 2114 ktrsysctl(name, namelen); 2115 #endif 2116 memlocked = 0; 2117 if (req.oldptr && req.oldlen > 4 * PAGE_SIZE) { 2118 memlocked = 1; 2119 sx_xlock(&sysctlmemlock); 2120 } 2121 CURVNET_SET(TD_TO_VNET(td)); 2122 2123 for (;;) { 2124 req.oldidx = 0; 2125 req.newidx = 0; 2126 error = sysctl_root(0, name, namelen, &req); 2127 if (error != EAGAIN) 2128 break; 2129 kern_yield(PRI_USER); 2130 } 2131 2132 CURVNET_RESTORE(); 2133 2134 if (req.lock == REQ_WIRED && req.validlen > 0) 2135 vsunlock(req.oldptr, req.validlen); 2136 if (memlocked) 2137 sx_xunlock(&sysctlmemlock); 2138 2139 if (error && error != ENOMEM) 2140 return (error); 2141 2142 if (retval) { 2143 if (req.oldptr && req.oldidx > req.validlen) 2144 *retval = req.validlen; 2145 else 2146 *retval = req.oldidx; 2147 } 2148 return (error); 2149 } 2150 2151 /* 2152 * Drain into a sysctl struct. The user buffer should be wired if a page 2153 * fault would cause issue. 2154 */ 2155 static int 2156 sbuf_sysctl_drain(void *arg, const char *data, int len) 2157 { 2158 struct sysctl_req *req = arg; 2159 int error; 2160 2161 error = SYSCTL_OUT(req, data, len); 2162 KASSERT(error >= 0, ("Got unexpected negative value %d", error)); 2163 return (error == 0 ? len : -error); 2164 } 2165 2166 struct sbuf * 2167 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length, 2168 struct sysctl_req *req) 2169 { 2170 2171 /* Supply a default buffer size if none given. */ 2172 if (buf == NULL && length == 0) 2173 length = 64; 2174 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN | SBUF_INCLUDENUL); 2175 sbuf_set_drain(s, sbuf_sysctl_drain, req); 2176 return (s); 2177 } 2178