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_compat.h" 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/fail.h> 46 #include <sys/systm.h> 47 #include <sys/kernel.h> 48 #include <sys/sysctl.h> 49 #include <sys/malloc.h> 50 #include <sys/priv.h> 51 #include <sys/proc.h> 52 #include <sys/jail.h> 53 #include <sys/lock.h> 54 #include <sys/mutex.h> 55 #include <sys/sbuf.h> 56 #include <sys/sx.h> 57 #include <sys/sysproto.h> 58 #include <sys/uio.h> 59 #ifdef KTRACE 60 #include <sys/ktrace.h> 61 #endif 62 63 #include <net/vnet.h> 64 65 #include <security/mac/mac_framework.h> 66 67 #include <vm/vm.h> 68 #include <vm/vm_extern.h> 69 70 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic"); 71 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids"); 72 static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer"); 73 74 /* 75 * The sysctllock protects the MIB tree. It also protects sysctl 76 * contexts used with dynamic sysctls. The sysctl_register_oid() and 77 * sysctl_unregister_oid() routines require the sysctllock to already 78 * be held, so the sysctl_lock() and sysctl_unlock() routines are 79 * provided for the few places in the kernel which need to use that 80 * API rather than using the dynamic API. Use of the dynamic API is 81 * strongly encouraged for most code. 82 * 83 * The sysctlmemlock is used to limit the amount of user memory wired for 84 * sysctl requests. This is implemented by serializing any userland 85 * sysctl requests larger than a single page via an exclusive lock. 86 */ 87 static struct sx sysctllock; 88 static struct sx sysctlmemlock; 89 90 #define SYSCTL_XLOCK() sx_xlock(&sysctllock) 91 #define SYSCTL_XUNLOCK() sx_xunlock(&sysctllock) 92 #define SYSCTL_ASSERT_XLOCKED() sx_assert(&sysctllock, SA_XLOCKED) 93 #define SYSCTL_INIT() sx_init(&sysctllock, "sysctl lock") 94 #define SYSCTL_SLEEP(ch, wmesg, timo) \ 95 sx_sleep(ch, &sysctllock, 0, wmesg, timo) 96 97 static int sysctl_root(SYSCTL_HANDLER_ARGS); 98 99 struct sysctl_oid_list sysctl__children; /* root list */ 100 101 static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, 102 int recurse); 103 104 static struct sysctl_oid * 105 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list) 106 { 107 struct sysctl_oid *oidp; 108 109 SYSCTL_ASSERT_XLOCKED(); 110 SLIST_FOREACH(oidp, list, oid_link) { 111 if (strcmp(oidp->oid_name, name) == 0) { 112 return (oidp); 113 } 114 } 115 return (NULL); 116 } 117 118 /* 119 * Initialization of the MIB tree. 120 * 121 * Order by number in each list. 122 */ 123 void 124 sysctl_lock(void) 125 { 126 127 SYSCTL_XLOCK(); 128 } 129 130 void 131 sysctl_unlock(void) 132 { 133 134 SYSCTL_XUNLOCK(); 135 } 136 137 void 138 sysctl_register_oid(struct sysctl_oid *oidp) 139 { 140 struct sysctl_oid_list *parent = oidp->oid_parent; 141 struct sysctl_oid *p; 142 struct sysctl_oid *q; 143 144 /* 145 * First check if another oid with the same name already 146 * exists in the parent's list. 147 */ 148 SYSCTL_ASSERT_XLOCKED(); 149 p = sysctl_find_oidname(oidp->oid_name, parent); 150 if (p != NULL) { 151 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 152 p->oid_refcnt++; 153 return; 154 } else { 155 printf("can't re-use a leaf (%s)!\n", p->oid_name); 156 return; 157 } 158 } 159 /* 160 * If this oid has a number OID_AUTO, give it a number which 161 * is greater than any current oid. 162 * NOTE: DO NOT change the starting value here, change it in 163 * <sys/sysctl.h>, and make sure it is at least 256 to 164 * accomodate e.g. net.inet.raw as a static sysctl node. 165 */ 166 if (oidp->oid_number == OID_AUTO) { 167 static int newoid = CTL_AUTO_START; 168 169 oidp->oid_number = newoid++; 170 if (newoid == 0x7fffffff) 171 panic("out of oids"); 172 } 173 #if 0 174 else if (oidp->oid_number >= CTL_AUTO_START) { 175 /* do not panic; this happens when unregistering sysctl sets */ 176 printf("static sysctl oid too high: %d", oidp->oid_number); 177 } 178 #endif 179 180 /* 181 * Insert the oid into the parent's list in order. 182 */ 183 q = NULL; 184 SLIST_FOREACH(p, parent, oid_link) { 185 if (oidp->oid_number < p->oid_number) 186 break; 187 q = p; 188 } 189 if (q) 190 SLIST_INSERT_AFTER(q, oidp, oid_link); 191 else 192 SLIST_INSERT_HEAD(parent, oidp, oid_link); 193 } 194 195 void 196 sysctl_unregister_oid(struct sysctl_oid *oidp) 197 { 198 struct sysctl_oid *p; 199 int error; 200 201 SYSCTL_ASSERT_XLOCKED(); 202 error = ENOENT; 203 if (oidp->oid_number == OID_AUTO) { 204 error = EINVAL; 205 } else { 206 SLIST_FOREACH(p, oidp->oid_parent, oid_link) { 207 if (p == oidp) { 208 SLIST_REMOVE(oidp->oid_parent, oidp, 209 sysctl_oid, oid_link); 210 error = 0; 211 break; 212 } 213 } 214 } 215 216 /* 217 * This can happen when a module fails to register and is 218 * being unloaded afterwards. It should not be a panic() 219 * for normal use. 220 */ 221 if (error) 222 printf("%s: failed to unregister sysctl\n", __func__); 223 } 224 225 /* Initialize a new context to keep track of dynamically added sysctls. */ 226 int 227 sysctl_ctx_init(struct sysctl_ctx_list *c) 228 { 229 230 if (c == NULL) { 231 return (EINVAL); 232 } 233 234 /* 235 * No locking here, the caller is responsible for not adding 236 * new nodes to a context until after this function has 237 * returned. 238 */ 239 TAILQ_INIT(c); 240 return (0); 241 } 242 243 /* Free the context, and destroy all dynamic oids registered in this context */ 244 int 245 sysctl_ctx_free(struct sysctl_ctx_list *clist) 246 { 247 struct sysctl_ctx_entry *e, *e1; 248 int error; 249 250 error = 0; 251 /* 252 * First perform a "dry run" to check if it's ok to remove oids. 253 * XXX FIXME 254 * XXX This algorithm is a hack. But I don't know any 255 * XXX better solution for now... 256 */ 257 SYSCTL_XLOCK(); 258 TAILQ_FOREACH(e, clist, link) { 259 error = sysctl_remove_oid_locked(e->entry, 0, 0); 260 if (error) 261 break; 262 } 263 /* 264 * Restore deregistered entries, either from the end, 265 * or from the place where error occured. 266 * e contains the entry that was not unregistered 267 */ 268 if (error) 269 e1 = TAILQ_PREV(e, sysctl_ctx_list, link); 270 else 271 e1 = TAILQ_LAST(clist, sysctl_ctx_list); 272 while (e1 != NULL) { 273 sysctl_register_oid(e1->entry); 274 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link); 275 } 276 if (error) { 277 SYSCTL_XUNLOCK(); 278 return(EBUSY); 279 } 280 /* Now really delete the entries */ 281 e = TAILQ_FIRST(clist); 282 while (e != NULL) { 283 e1 = TAILQ_NEXT(e, link); 284 error = sysctl_remove_oid_locked(e->entry, 1, 0); 285 if (error) 286 panic("sysctl_remove_oid: corrupt tree, entry: %s", 287 e->entry->oid_name); 288 free(e, M_SYSCTLOID); 289 e = e1; 290 } 291 SYSCTL_XUNLOCK(); 292 return (error); 293 } 294 295 /* Add an entry to the context */ 296 struct sysctl_ctx_entry * 297 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 298 { 299 struct sysctl_ctx_entry *e; 300 301 SYSCTL_ASSERT_XLOCKED(); 302 if (clist == NULL || oidp == NULL) 303 return(NULL); 304 e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK); 305 e->entry = oidp; 306 TAILQ_INSERT_HEAD(clist, e, link); 307 return (e); 308 } 309 310 /* Find an entry in the context */ 311 struct sysctl_ctx_entry * 312 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 313 { 314 struct sysctl_ctx_entry *e; 315 316 SYSCTL_ASSERT_XLOCKED(); 317 if (clist == NULL || oidp == NULL) 318 return(NULL); 319 TAILQ_FOREACH(e, clist, link) { 320 if(e->entry == oidp) 321 return(e); 322 } 323 return (e); 324 } 325 326 /* 327 * Delete an entry from the context. 328 * NOTE: this function doesn't free oidp! You have to remove it 329 * with sysctl_remove_oid(). 330 */ 331 int 332 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 333 { 334 struct sysctl_ctx_entry *e; 335 336 if (clist == NULL || oidp == NULL) 337 return (EINVAL); 338 SYSCTL_XLOCK(); 339 e = sysctl_ctx_entry_find(clist, oidp); 340 if (e != NULL) { 341 TAILQ_REMOVE(clist, e, link); 342 SYSCTL_XUNLOCK(); 343 free(e, M_SYSCTLOID); 344 return (0); 345 } else { 346 SYSCTL_XUNLOCK(); 347 return (ENOENT); 348 } 349 } 350 351 /* 352 * Remove dynamically created sysctl trees. 353 * oidp - top of the tree to be removed 354 * del - if 0 - just deregister, otherwise free up entries as well 355 * recurse - if != 0 traverse the subtree to be deleted 356 */ 357 int 358 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse) 359 { 360 int error; 361 362 SYSCTL_XLOCK(); 363 error = sysctl_remove_oid_locked(oidp, del, recurse); 364 SYSCTL_XUNLOCK(); 365 return (error); 366 } 367 368 int 369 sysctl_remove_name(struct sysctl_oid *parent, const char *name, 370 int del, int recurse) 371 { 372 struct sysctl_oid *p, *tmp; 373 int error; 374 375 error = ENOENT; 376 SYSCTL_XLOCK(); 377 SLIST_FOREACH_SAFE(p, SYSCTL_CHILDREN(parent), oid_link, tmp) { 378 if (strcmp(p->oid_name, name) == 0) { 379 error = sysctl_remove_oid_locked(p, del, recurse); 380 break; 381 } 382 } 383 SYSCTL_XUNLOCK(); 384 385 return (error); 386 } 387 388 389 static int 390 sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse) 391 { 392 struct sysctl_oid *p, *tmp; 393 int error; 394 395 SYSCTL_ASSERT_XLOCKED(); 396 if (oidp == NULL) 397 return(EINVAL); 398 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) { 399 printf("can't remove non-dynamic nodes!\n"); 400 return (EINVAL); 401 } 402 /* 403 * WARNING: normal method to do this should be through 404 * sysctl_ctx_free(). Use recursing as the last resort 405 * method to purge your sysctl tree of leftovers... 406 * However, if some other code still references these nodes, 407 * it will panic. 408 */ 409 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 410 if (oidp->oid_refcnt == 1) { 411 SLIST_FOREACH_SAFE(p, 412 SYSCTL_CHILDREN(oidp), oid_link, tmp) { 413 if (!recurse) 414 return (ENOTEMPTY); 415 error = sysctl_remove_oid_locked(p, del, 416 recurse); 417 if (error) 418 return (error); 419 } 420 if (del) 421 free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID); 422 } 423 } 424 if (oidp->oid_refcnt > 1 ) { 425 oidp->oid_refcnt--; 426 } else { 427 if (oidp->oid_refcnt == 0) { 428 printf("Warning: bad oid_refcnt=%u (%s)!\n", 429 oidp->oid_refcnt, oidp->oid_name); 430 return (EINVAL); 431 } 432 sysctl_unregister_oid(oidp); 433 if (del) { 434 /* 435 * Wait for all threads running the handler to drain. 436 * This preserves the previous behavior when the 437 * sysctl lock was held across a handler invocation, 438 * and is necessary for module unload correctness. 439 */ 440 while (oidp->oid_running > 0) { 441 oidp->oid_kind |= CTLFLAG_DYING; 442 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0); 443 } 444 if (oidp->oid_descr) 445 free((void *)(uintptr_t)(const void *)oidp->oid_descr, M_SYSCTLOID); 446 free((void *)(uintptr_t)(const void *)oidp->oid_name, 447 M_SYSCTLOID); 448 free(oidp, M_SYSCTLOID); 449 } 450 } 451 return (0); 452 } 453 /* 454 * Create new sysctls at run time. 455 * clist may point to a valid context initialized with sysctl_ctx_init(). 456 */ 457 struct sysctl_oid * 458 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, 459 int number, const char *name, int kind, void *arg1, intptr_t arg2, 460 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr) 461 { 462 struct sysctl_oid *oidp; 463 ssize_t len; 464 char *newname; 465 466 /* You have to hook up somewhere.. */ 467 if (parent == NULL) 468 return(NULL); 469 /* Check if the node already exists, otherwise create it */ 470 SYSCTL_XLOCK(); 471 oidp = sysctl_find_oidname(name, parent); 472 if (oidp != NULL) { 473 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 474 oidp->oid_refcnt++; 475 /* Update the context */ 476 if (clist != NULL) 477 sysctl_ctx_entry_add(clist, oidp); 478 SYSCTL_XUNLOCK(); 479 return (oidp); 480 } else { 481 SYSCTL_XUNLOCK(); 482 printf("can't re-use a leaf (%s)!\n", name); 483 return (NULL); 484 } 485 } 486 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO); 487 oidp->oid_parent = parent; 488 SLIST_NEXT(oidp, oid_link) = NULL; 489 oidp->oid_number = number; 490 oidp->oid_refcnt = 1; 491 len = strlen(name); 492 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK); 493 bcopy(name, newname, len + 1); 494 newname[len] = '\0'; 495 oidp->oid_name = newname; 496 oidp->oid_handler = handler; 497 oidp->oid_kind = CTLFLAG_DYN | kind; 498 if ((kind & CTLTYPE) == CTLTYPE_NODE) { 499 /* Allocate space for children */ 500 SYSCTL_CHILDREN_SET(oidp, malloc(sizeof(struct sysctl_oid_list), 501 M_SYSCTLOID, M_WAITOK)); 502 SLIST_INIT(SYSCTL_CHILDREN(oidp)); 503 oidp->oid_arg2 = arg2; 504 } else { 505 oidp->oid_arg1 = arg1; 506 oidp->oid_arg2 = arg2; 507 } 508 oidp->oid_fmt = fmt; 509 if (descr) { 510 int len = strlen(descr) + 1; 511 oidp->oid_descr = malloc(len, M_SYSCTLOID, M_WAITOK); 512 if (oidp->oid_descr) 513 strcpy((char *)(uintptr_t)(const void *)oidp->oid_descr, descr); 514 } 515 /* Update the context, if used */ 516 if (clist != NULL) 517 sysctl_ctx_entry_add(clist, oidp); 518 /* Register this oid */ 519 sysctl_register_oid(oidp); 520 SYSCTL_XUNLOCK(); 521 return (oidp); 522 } 523 524 /* 525 * Rename an existing oid. 526 */ 527 void 528 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) 529 { 530 ssize_t len; 531 char *newname; 532 void *oldname; 533 534 len = strlen(name); 535 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK); 536 bcopy(name, newname, len + 1); 537 newname[len] = '\0'; 538 SYSCTL_XLOCK(); 539 oldname = (void *)(uintptr_t)(const void *)oidp->oid_name; 540 oidp->oid_name = newname; 541 SYSCTL_XUNLOCK(); 542 free(oldname, M_SYSCTLOID); 543 } 544 545 /* 546 * Reparent an existing oid. 547 */ 548 int 549 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent) 550 { 551 struct sysctl_oid *oidp; 552 553 SYSCTL_XLOCK(); 554 if (oid->oid_parent == parent) { 555 SYSCTL_XUNLOCK(); 556 return (0); 557 } 558 oidp = sysctl_find_oidname(oid->oid_name, parent); 559 if (oidp != NULL) { 560 SYSCTL_XUNLOCK(); 561 return (EEXIST); 562 } 563 sysctl_unregister_oid(oid); 564 oid->oid_parent = parent; 565 oid->oid_number = OID_AUTO; 566 sysctl_register_oid(oid); 567 SYSCTL_XUNLOCK(); 568 return (0); 569 } 570 571 /* 572 * Register the kernel's oids on startup. 573 */ 574 SET_DECLARE(sysctl_set, struct sysctl_oid); 575 576 static void 577 sysctl_register_all(void *arg) 578 { 579 struct sysctl_oid **oidp; 580 581 sx_init(&sysctlmemlock, "sysctl mem"); 582 SYSCTL_INIT(); 583 SYSCTL_XLOCK(); 584 SET_FOREACH(oidp, sysctl_set) 585 sysctl_register_oid(*oidp); 586 SYSCTL_XUNLOCK(); 587 } 588 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0); 589 590 /* 591 * "Staff-functions" 592 * 593 * These functions implement a presently undocumented interface 594 * used by the sysctl program to walk the tree, and get the type 595 * so it can print the value. 596 * This interface is under work and consideration, and should probably 597 * be killed with a big axe by the first person who can find the time. 598 * (be aware though, that the proper interface isn't as obvious as it 599 * may seem, there are various conflicting requirements. 600 * 601 * {0,0} printf the entire MIB-tree. 602 * {0,1,...} return the name of the "..." OID. 603 * {0,2,...} return the next OID. 604 * {0,3} return the OID of the name in "new" 605 * {0,4,...} return the kind & format info for the "..." OID. 606 * {0,5,...} return the description the "..." OID. 607 */ 608 609 #ifdef SYSCTL_DEBUG 610 static void 611 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 612 { 613 int k; 614 struct sysctl_oid *oidp; 615 616 SYSCTL_ASSERT_XLOCKED(); 617 SLIST_FOREACH(oidp, l, oid_link) { 618 619 for (k=0; k<i; k++) 620 printf(" "); 621 622 printf("%d %s ", oidp->oid_number, oidp->oid_name); 623 624 printf("%c%c", 625 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 626 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 627 628 if (oidp->oid_handler) 629 printf(" *Handler"); 630 631 switch (oidp->oid_kind & CTLTYPE) { 632 case CTLTYPE_NODE: 633 printf(" Node\n"); 634 if (!oidp->oid_handler) { 635 sysctl_sysctl_debug_dump_node( 636 oidp->oid_arg1, i+2); 637 } 638 break; 639 case CTLTYPE_INT: printf(" Int\n"); break; 640 case CTLTYPE_UINT: printf(" u_int\n"); break; 641 case CTLTYPE_LONG: printf(" Long\n"); break; 642 case CTLTYPE_ULONG: printf(" u_long\n"); break; 643 case CTLTYPE_STRING: printf(" String\n"); break; 644 case CTLTYPE_U64: printf(" uint64_t\n"); break; 645 case CTLTYPE_S64: printf(" int64_t\n"); break; 646 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break; 647 default: printf("\n"); 648 } 649 650 } 651 } 652 653 static int 654 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 655 { 656 int error; 657 658 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 659 if (error) 660 return (error); 661 SYSCTL_XLOCK(); 662 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 663 SYSCTL_XUNLOCK(); 664 return (ENOENT); 665 } 666 667 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD, 668 0, 0, sysctl_sysctl_debug, "-", ""); 669 #endif 670 671 static int 672 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 673 { 674 int *name = (int *) arg1; 675 u_int namelen = arg2; 676 int error = 0; 677 struct sysctl_oid *oid; 678 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 679 char buf[10]; 680 681 SYSCTL_XLOCK(); 682 while (namelen) { 683 if (!lsp) { 684 snprintf(buf,sizeof(buf),"%d",*name); 685 if (req->oldidx) 686 error = SYSCTL_OUT(req, ".", 1); 687 if (!error) 688 error = SYSCTL_OUT(req, buf, strlen(buf)); 689 if (error) 690 goto out; 691 namelen--; 692 name++; 693 continue; 694 } 695 lsp2 = 0; 696 SLIST_FOREACH(oid, lsp, oid_link) { 697 if (oid->oid_number != *name) 698 continue; 699 700 if (req->oldidx) 701 error = SYSCTL_OUT(req, ".", 1); 702 if (!error) 703 error = SYSCTL_OUT(req, oid->oid_name, 704 strlen(oid->oid_name)); 705 if (error) 706 goto out; 707 708 namelen--; 709 name++; 710 711 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 712 break; 713 714 if (oid->oid_handler) 715 break; 716 717 lsp2 = SYSCTL_CHILDREN(oid); 718 break; 719 } 720 lsp = lsp2; 721 } 722 error = SYSCTL_OUT(req, "", 1); 723 out: 724 SYSCTL_XUNLOCK(); 725 return (error); 726 } 727 728 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, ""); 729 730 static int 731 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 732 int *next, int *len, int level, struct sysctl_oid **oidpp) 733 { 734 struct sysctl_oid *oidp; 735 736 SYSCTL_ASSERT_XLOCKED(); 737 *len = level; 738 SLIST_FOREACH(oidp, lsp, oid_link) { 739 *next = oidp->oid_number; 740 *oidpp = oidp; 741 742 if (oidp->oid_kind & CTLFLAG_SKIP) 743 continue; 744 745 if (!namelen) { 746 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 747 return (0); 748 if (oidp->oid_handler) 749 /* We really should call the handler here...*/ 750 return (0); 751 lsp = SYSCTL_CHILDREN(oidp); 752 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 753 len, level+1, oidpp)) 754 return (0); 755 goto emptynode; 756 } 757 758 if (oidp->oid_number < *name) 759 continue; 760 761 if (oidp->oid_number > *name) { 762 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 763 return (0); 764 if (oidp->oid_handler) 765 return (0); 766 lsp = SYSCTL_CHILDREN(oidp); 767 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 768 next+1, len, level+1, oidpp)) 769 return (0); 770 goto next; 771 } 772 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 773 continue; 774 775 if (oidp->oid_handler) 776 continue; 777 778 lsp = SYSCTL_CHILDREN(oidp); 779 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 780 len, level+1, oidpp)) 781 return (0); 782 next: 783 namelen = 1; 784 emptynode: 785 *len = level; 786 } 787 return (1); 788 } 789 790 static int 791 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 792 { 793 int *name = (int *) arg1; 794 u_int namelen = arg2; 795 int i, j, error; 796 struct sysctl_oid *oid; 797 struct sysctl_oid_list *lsp = &sysctl__children; 798 int newoid[CTL_MAXNAME]; 799 800 SYSCTL_XLOCK(); 801 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 802 SYSCTL_XUNLOCK(); 803 if (i) 804 return (ENOENT); 805 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 806 return (error); 807 } 808 809 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, ""); 810 811 static int 812 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) 813 { 814 int i; 815 struct sysctl_oid *oidp; 816 struct sysctl_oid_list *lsp = &sysctl__children; 817 char *p; 818 819 SYSCTL_ASSERT_XLOCKED(); 820 821 if (!*name) 822 return (ENOENT); 823 824 p = name + strlen(name) - 1 ; 825 if (*p == '.') 826 *p = '\0'; 827 828 *len = 0; 829 830 for (p = name; *p && *p != '.'; p++) 831 ; 832 i = *p; 833 if (i == '.') 834 *p = '\0'; 835 836 oidp = SLIST_FIRST(lsp); 837 838 while (oidp && *len < CTL_MAXNAME) { 839 if (strcmp(name, oidp->oid_name)) { 840 oidp = SLIST_NEXT(oidp, oid_link); 841 continue; 842 } 843 *oid++ = oidp->oid_number; 844 (*len)++; 845 846 if (!i) { 847 if (oidpp) 848 *oidpp = oidp; 849 return (0); 850 } 851 852 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 853 break; 854 855 if (oidp->oid_handler) 856 break; 857 858 lsp = SYSCTL_CHILDREN(oidp); 859 oidp = SLIST_FIRST(lsp); 860 name = p+1; 861 for (p = name; *p && *p != '.'; p++) 862 ; 863 i = *p; 864 if (i == '.') 865 *p = '\0'; 866 } 867 return (ENOENT); 868 } 869 870 static int 871 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 872 { 873 char *p; 874 int error, oid[CTL_MAXNAME], len = 0; 875 struct sysctl_oid *op = 0; 876 877 if (!req->newlen) 878 return (ENOENT); 879 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 880 return (ENAMETOOLONG); 881 882 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK); 883 884 error = SYSCTL_IN(req, p, req->newlen); 885 if (error) { 886 free(p, M_SYSCTL); 887 return (error); 888 } 889 890 p [req->newlen] = '\0'; 891 892 SYSCTL_XLOCK(); 893 error = name2oid(p, oid, &len, &op); 894 SYSCTL_XUNLOCK(); 895 896 free(p, M_SYSCTL); 897 898 if (error) 899 return (error); 900 901 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 902 return (error); 903 } 904 905 SYSCTL_PROC(_sysctl, 3, name2oid, 906 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE, 907 0, 0, sysctl_sysctl_name2oid, "I", ""); 908 909 static int 910 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 911 { 912 struct sysctl_oid *oid; 913 int error; 914 915 SYSCTL_XLOCK(); 916 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 917 if (error) 918 goto out; 919 920 if (oid->oid_fmt == NULL) { 921 error = ENOENT; 922 goto out; 923 } 924 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 925 if (error) 926 goto out; 927 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 928 out: 929 SYSCTL_XUNLOCK(); 930 return (error); 931 } 932 933 934 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE, 935 sysctl_sysctl_oidfmt, ""); 936 937 static int 938 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 939 { 940 struct sysctl_oid *oid; 941 int error; 942 943 SYSCTL_XLOCK(); 944 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 945 if (error) 946 goto out; 947 948 if (oid->oid_descr == NULL) { 949 error = ENOENT; 950 goto out; 951 } 952 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 953 out: 954 SYSCTL_XUNLOCK(); 955 return (error); 956 } 957 958 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD, sysctl_sysctl_oiddescr, ""); 959 960 /* 961 * Default "handler" functions. 962 */ 963 964 /* 965 * Handle an int, signed or unsigned. 966 * Two cases: 967 * a variable: point arg1 at it. 968 * a constant: pass it in arg2. 969 */ 970 971 int 972 sysctl_handle_int(SYSCTL_HANDLER_ARGS) 973 { 974 int tmpout, error = 0; 975 976 /* 977 * Attempt to get a coherent snapshot by making a copy of the data. 978 */ 979 if (arg1) 980 tmpout = *(int *)arg1; 981 else 982 tmpout = arg2; 983 error = SYSCTL_OUT(req, &tmpout, sizeof(int)); 984 985 if (error || !req->newptr) 986 return (error); 987 988 if (!arg1) 989 error = EPERM; 990 else 991 error = SYSCTL_IN(req, arg1, sizeof(int)); 992 return (error); 993 } 994 995 /* 996 * Based on on sysctl_handle_int() convert milliseconds into ticks. 997 * Note: this is used by TCP. 998 */ 999 1000 int 1001 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) 1002 { 1003 int error, s, tt; 1004 1005 tt = *(int *)arg1; 1006 s = (int)((int64_t)tt * 1000 / hz); 1007 1008 error = sysctl_handle_int(oidp, &s, 0, req); 1009 if (error || !req->newptr) 1010 return (error); 1011 1012 tt = (int)((int64_t)s * hz / 1000); 1013 if (tt < 1) 1014 return (EINVAL); 1015 1016 *(int *)arg1 = tt; 1017 return (0); 1018 } 1019 1020 1021 /* 1022 * Handle a long, signed or unsigned. arg1 points to it. 1023 */ 1024 1025 int 1026 sysctl_handle_long(SYSCTL_HANDLER_ARGS) 1027 { 1028 int error = 0; 1029 long tmplong; 1030 #ifdef SCTL_MASK32 1031 int tmpint; 1032 #endif 1033 1034 /* 1035 * Attempt to get a coherent snapshot by making a copy of the data. 1036 */ 1037 if (!arg1) 1038 return (EINVAL); 1039 tmplong = *(long *)arg1; 1040 #ifdef SCTL_MASK32 1041 if (req->flags & SCTL_MASK32) { 1042 tmpint = tmplong; 1043 error = SYSCTL_OUT(req, &tmpint, sizeof(int)); 1044 } else 1045 #endif 1046 error = SYSCTL_OUT(req, &tmplong, sizeof(long)); 1047 1048 if (error || !req->newptr) 1049 return (error); 1050 1051 #ifdef SCTL_MASK32 1052 if (req->flags & SCTL_MASK32) { 1053 error = SYSCTL_IN(req, &tmpint, sizeof(int)); 1054 *(long *)arg1 = (long)tmpint; 1055 } else 1056 #endif 1057 error = SYSCTL_IN(req, arg1, sizeof(long)); 1058 return (error); 1059 } 1060 1061 /* 1062 * Handle a 64 bit int, signed or unsigned. arg1 points to it. 1063 */ 1064 int 1065 sysctl_handle_64(SYSCTL_HANDLER_ARGS) 1066 { 1067 int error = 0; 1068 uint64_t tmpout; 1069 1070 /* 1071 * Attempt to get a coherent snapshot by making a copy of the data. 1072 */ 1073 if (!arg1) 1074 return (EINVAL); 1075 tmpout = *(uint64_t *)arg1; 1076 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t)); 1077 1078 if (error || !req->newptr) 1079 return (error); 1080 1081 error = SYSCTL_IN(req, arg1, sizeof(uint64_t)); 1082 return (error); 1083 } 1084 1085 /* 1086 * Handle our generic '\0' terminated 'C' string. 1087 * Two cases: 1088 * a variable string: point arg1 at it, arg2 is max length. 1089 * a constant string: point arg1 at it, arg2 is zero. 1090 */ 1091 1092 int 1093 sysctl_handle_string(SYSCTL_HANDLER_ARGS) 1094 { 1095 int error=0; 1096 char *tmparg; 1097 size_t outlen; 1098 1099 /* 1100 * Attempt to get a coherent snapshot by copying to a 1101 * temporary kernel buffer. 1102 */ 1103 retry: 1104 outlen = strlen((char *)arg1)+1; 1105 tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK); 1106 1107 if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) { 1108 free(tmparg, M_SYSCTLTMP); 1109 goto retry; 1110 } 1111 1112 error = SYSCTL_OUT(req, tmparg, outlen); 1113 free(tmparg, M_SYSCTLTMP); 1114 1115 if (error || !req->newptr) 1116 return (error); 1117 1118 if ((req->newlen - req->newidx) >= arg2) { 1119 error = EINVAL; 1120 } else { 1121 arg2 = (req->newlen - req->newidx); 1122 error = SYSCTL_IN(req, arg1, arg2); 1123 ((char *)arg1)[arg2] = '\0'; 1124 } 1125 1126 return (error); 1127 } 1128 1129 /* 1130 * Handle any kind of opaque data. 1131 * arg1 points to it, arg2 is the size. 1132 */ 1133 1134 int 1135 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 1136 { 1137 int error, tries; 1138 u_int generation; 1139 struct sysctl_req req2; 1140 1141 /* 1142 * Attempt to get a coherent snapshot, by using the thread 1143 * pre-emption counter updated from within mi_switch() to 1144 * determine if we were pre-empted during a bcopy() or 1145 * copyout(). Make 3 attempts at doing this before giving up. 1146 * If we encounter an error, stop immediately. 1147 */ 1148 tries = 0; 1149 req2 = *req; 1150 retry: 1151 generation = curthread->td_generation; 1152 error = SYSCTL_OUT(req, arg1, arg2); 1153 if (error) 1154 return (error); 1155 tries++; 1156 if (generation != curthread->td_generation && tries < 3) { 1157 *req = req2; 1158 goto retry; 1159 } 1160 1161 error = SYSCTL_IN(req, arg1, arg2); 1162 1163 return (error); 1164 } 1165 1166 /* 1167 * Transfer functions to/from kernel space. 1168 * XXX: rather untested at this point 1169 */ 1170 static int 1171 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 1172 { 1173 size_t i = 0; 1174 1175 if (req->oldptr) { 1176 i = l; 1177 if (req->oldlen <= req->oldidx) 1178 i = 0; 1179 else 1180 if (i > req->oldlen - req->oldidx) 1181 i = req->oldlen - req->oldidx; 1182 if (i > 0) 1183 bcopy(p, (char *)req->oldptr + req->oldidx, i); 1184 } 1185 req->oldidx += l; 1186 if (req->oldptr && i != l) 1187 return (ENOMEM); 1188 return (0); 1189 } 1190 1191 static int 1192 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 1193 { 1194 if (!req->newptr) 1195 return (0); 1196 if (req->newlen - req->newidx < l) 1197 return (EINVAL); 1198 bcopy((char *)req->newptr + req->newidx, p, l); 1199 req->newidx += l; 1200 return (0); 1201 } 1202 1203 int 1204 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1205 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags) 1206 { 1207 int error = 0; 1208 struct sysctl_req req; 1209 1210 bzero(&req, sizeof req); 1211 1212 req.td = td; 1213 req.flags = flags; 1214 1215 if (oldlenp) { 1216 req.oldlen = *oldlenp; 1217 } 1218 req.validlen = req.oldlen; 1219 1220 if (old) { 1221 req.oldptr= old; 1222 } 1223 1224 if (new != NULL) { 1225 req.newlen = newlen; 1226 req.newptr = new; 1227 } 1228 1229 req.oldfunc = sysctl_old_kernel; 1230 req.newfunc = sysctl_new_kernel; 1231 req.lock = REQ_UNWIRED; 1232 1233 SYSCTL_XLOCK(); 1234 error = sysctl_root(0, name, namelen, &req); 1235 SYSCTL_XUNLOCK(); 1236 1237 if (req.lock == REQ_WIRED && req.validlen > 0) 1238 vsunlock(req.oldptr, req.validlen); 1239 1240 if (error && error != ENOMEM) 1241 return (error); 1242 1243 if (retval) { 1244 if (req.oldptr && req.oldidx > req.validlen) 1245 *retval = req.validlen; 1246 else 1247 *retval = req.oldidx; 1248 } 1249 return (error); 1250 } 1251 1252 int 1253 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp, 1254 void *new, size_t newlen, size_t *retval, int flags) 1255 { 1256 int oid[CTL_MAXNAME]; 1257 size_t oidlen, plen; 1258 int error; 1259 1260 oid[0] = 0; /* sysctl internal magic */ 1261 oid[1] = 3; /* name2oid */ 1262 oidlen = sizeof(oid); 1263 1264 error = kernel_sysctl(td, oid, 2, oid, &oidlen, 1265 (void *)name, strlen(name), &plen, flags); 1266 if (error) 1267 return (error); 1268 1269 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp, 1270 new, newlen, retval, flags); 1271 return (error); 1272 } 1273 1274 /* 1275 * Transfer function to/from user space. 1276 */ 1277 static int 1278 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1279 { 1280 int error = 0; 1281 size_t i, len, origidx; 1282 1283 origidx = req->oldidx; 1284 req->oldidx += l; 1285 if (req->oldptr == NULL) 1286 return (0); 1287 /* 1288 * If we have not wired the user supplied buffer and we are currently 1289 * holding locks, drop a witness warning, as it's possible that 1290 * write operations to the user page can sleep. 1291 */ 1292 if (req->lock != REQ_WIRED) 1293 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1294 "sysctl_old_user()"); 1295 i = l; 1296 len = req->validlen; 1297 if (len <= origidx) 1298 i = 0; 1299 else { 1300 if (i > len - origidx) 1301 i = len - origidx; 1302 error = copyout(p, (char *)req->oldptr + origidx, i); 1303 } 1304 if (error) 1305 return (error); 1306 if (i < l) 1307 return (ENOMEM); 1308 return (0); 1309 } 1310 1311 static int 1312 sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1313 { 1314 int error; 1315 1316 if (!req->newptr) 1317 return (0); 1318 if (req->newlen - req->newidx < l) 1319 return (EINVAL); 1320 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1321 "sysctl_new_user()"); 1322 error = copyin((char *)req->newptr + req->newidx, p, l); 1323 req->newidx += l; 1324 return (error); 1325 } 1326 1327 /* 1328 * Wire the user space destination buffer. If set to a value greater than 1329 * zero, the len parameter limits the maximum amount of wired memory. 1330 */ 1331 int 1332 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len) 1333 { 1334 int ret; 1335 size_t wiredlen; 1336 1337 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen; 1338 ret = 0; 1339 if (req->lock != REQ_WIRED && req->oldptr && 1340 req->oldfunc == sysctl_old_user) { 1341 if (wiredlen != 0) { 1342 ret = vslock(req->oldptr, wiredlen); 1343 if (ret != 0) { 1344 if (ret != ENOMEM) 1345 return (ret); 1346 wiredlen = 0; 1347 } 1348 } 1349 req->lock = REQ_WIRED; 1350 req->validlen = wiredlen; 1351 } 1352 return (0); 1353 } 1354 1355 int 1356 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1357 int *nindx, struct sysctl_req *req) 1358 { 1359 struct sysctl_oid_list *lsp; 1360 struct sysctl_oid *oid; 1361 int indx; 1362 1363 SYSCTL_ASSERT_XLOCKED(); 1364 lsp = &sysctl__children; 1365 indx = 0; 1366 while (indx < CTL_MAXNAME) { 1367 SLIST_FOREACH(oid, lsp, oid_link) { 1368 if (oid->oid_number == name[indx]) 1369 break; 1370 } 1371 if (oid == NULL) 1372 return (ENOENT); 1373 1374 indx++; 1375 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1376 if (oid->oid_handler != NULL || indx == namelen) { 1377 *noid = oid; 1378 if (nindx != NULL) 1379 *nindx = indx; 1380 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1381 ("%s found DYING node %p", __func__, oid)); 1382 return (0); 1383 } 1384 lsp = SYSCTL_CHILDREN(oid); 1385 } else if (indx == namelen) { 1386 *noid = oid; 1387 if (nindx != NULL) 1388 *nindx = indx; 1389 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1390 ("%s found DYING node %p", __func__, oid)); 1391 return (0); 1392 } else { 1393 return (ENOTDIR); 1394 } 1395 } 1396 return (ENOENT); 1397 } 1398 1399 /* 1400 * Traverse our tree, and find the right node, execute whatever it points 1401 * to, and return the resulting error code. 1402 */ 1403 1404 static int 1405 sysctl_root(SYSCTL_HANDLER_ARGS) 1406 { 1407 struct sysctl_oid *oid; 1408 int error, indx, lvl; 1409 1410 SYSCTL_ASSERT_XLOCKED(); 1411 1412 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1413 if (error) 1414 return (error); 1415 1416 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1417 /* 1418 * You can't call a sysctl when it's a node, but has 1419 * no handler. Inform the user that it's a node. 1420 * The indx may or may not be the same as namelen. 1421 */ 1422 if (oid->oid_handler == NULL) 1423 return (EISDIR); 1424 } 1425 1426 /* Is this sysctl writable? */ 1427 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) 1428 return (EPERM); 1429 1430 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL")); 1431 1432 /* Is this sysctl sensitive to securelevels? */ 1433 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) { 1434 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE; 1435 error = securelevel_gt(req->td->td_ucred, lvl); 1436 if (error) 1437 return (error); 1438 } 1439 1440 /* Is this sysctl writable by only privileged users? */ 1441 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) { 1442 int priv; 1443 1444 if (oid->oid_kind & CTLFLAG_PRISON) 1445 priv = PRIV_SYSCTL_WRITEJAIL; 1446 #ifdef VIMAGE 1447 else if ((oid->oid_kind & CTLFLAG_VNET) && 1448 prison_owns_vnet(req->td->td_ucred)) 1449 priv = PRIV_SYSCTL_WRITEJAIL; 1450 #endif 1451 else 1452 priv = PRIV_SYSCTL_WRITE; 1453 error = priv_check(req->td, priv); 1454 if (error) 1455 return (error); 1456 } 1457 1458 if (!oid->oid_handler) 1459 return (EINVAL); 1460 1461 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1462 arg1 = (int *)arg1 + indx; 1463 arg2 -= indx; 1464 } else { 1465 arg1 = oid->oid_arg1; 1466 arg2 = oid->oid_arg2; 1467 } 1468 #ifdef MAC 1469 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2, 1470 req); 1471 if (error != 0) 1472 return (error); 1473 #endif 1474 oid->oid_running++; 1475 SYSCTL_XUNLOCK(); 1476 1477 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 1478 mtx_lock(&Giant); 1479 error = oid->oid_handler(oid, arg1, arg2, req); 1480 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 1481 mtx_unlock(&Giant); 1482 1483 KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error); 1484 1485 SYSCTL_XLOCK(); 1486 oid->oid_running--; 1487 if (oid->oid_running == 0 && (oid->oid_kind & CTLFLAG_DYING) != 0) 1488 wakeup(&oid->oid_running); 1489 return (error); 1490 } 1491 1492 #ifndef _SYS_SYSPROTO_H_ 1493 struct sysctl_args { 1494 int *name; 1495 u_int namelen; 1496 void *old; 1497 size_t *oldlenp; 1498 void *new; 1499 size_t newlen; 1500 }; 1501 #endif 1502 int 1503 __sysctl(struct thread *td, struct sysctl_args *uap) 1504 { 1505 int error, i, name[CTL_MAXNAME]; 1506 size_t j; 1507 1508 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 1509 return (EINVAL); 1510 1511 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 1512 if (error) 1513 return (error); 1514 1515 error = userland_sysctl(td, name, uap->namelen, 1516 uap->old, uap->oldlenp, 0, 1517 uap->new, uap->newlen, &j, 0); 1518 if (error && error != ENOMEM) 1519 return (error); 1520 if (uap->oldlenp) { 1521 i = copyout(&j, uap->oldlenp, sizeof(j)); 1522 if (i) 1523 return (i); 1524 } 1525 return (error); 1526 } 1527 1528 /* 1529 * This is used from various compatibility syscalls too. That's why name 1530 * must be in kernel space. 1531 */ 1532 int 1533 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1534 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval, 1535 int flags) 1536 { 1537 int error = 0, memlocked; 1538 struct sysctl_req req; 1539 1540 bzero(&req, sizeof req); 1541 1542 req.td = td; 1543 req.flags = flags; 1544 1545 if (oldlenp) { 1546 if (inkernel) { 1547 req.oldlen = *oldlenp; 1548 } else { 1549 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 1550 if (error) 1551 return (error); 1552 } 1553 } 1554 req.validlen = req.oldlen; 1555 1556 if (old) { 1557 if (!useracc(old, req.oldlen, VM_PROT_WRITE)) 1558 return (EFAULT); 1559 req.oldptr= old; 1560 } 1561 1562 if (new != NULL) { 1563 if (!useracc(new, newlen, VM_PROT_READ)) 1564 return (EFAULT); 1565 req.newlen = newlen; 1566 req.newptr = new; 1567 } 1568 1569 req.oldfunc = sysctl_old_user; 1570 req.newfunc = sysctl_new_user; 1571 req.lock = REQ_UNWIRED; 1572 1573 #ifdef KTRACE 1574 if (KTRPOINT(curthread, KTR_SYSCTL)) 1575 ktrsysctl(name, namelen); 1576 #endif 1577 1578 if (req.oldlen > PAGE_SIZE) { 1579 memlocked = 1; 1580 sx_xlock(&sysctlmemlock); 1581 } else 1582 memlocked = 0; 1583 CURVNET_SET(TD_TO_VNET(td)); 1584 1585 for (;;) { 1586 req.oldidx = 0; 1587 req.newidx = 0; 1588 SYSCTL_XLOCK(); 1589 error = sysctl_root(0, name, namelen, &req); 1590 SYSCTL_XUNLOCK(); 1591 if (error != EAGAIN) 1592 break; 1593 kern_yield(PRI_USER); 1594 } 1595 1596 CURVNET_RESTORE(); 1597 1598 if (req.lock == REQ_WIRED && req.validlen > 0) 1599 vsunlock(req.oldptr, req.validlen); 1600 if (memlocked) 1601 sx_xunlock(&sysctlmemlock); 1602 1603 if (error && error != ENOMEM) 1604 return (error); 1605 1606 if (retval) { 1607 if (req.oldptr && req.oldidx > req.validlen) 1608 *retval = req.validlen; 1609 else 1610 *retval = req.oldidx; 1611 } 1612 return (error); 1613 } 1614 1615 /* 1616 * Drain into a sysctl struct. The user buffer should be wired if a page 1617 * fault would cause issue. 1618 */ 1619 static int 1620 sbuf_sysctl_drain(void *arg, const char *data, int len) 1621 { 1622 struct sysctl_req *req = arg; 1623 int error; 1624 1625 error = SYSCTL_OUT(req, data, len); 1626 KASSERT(error >= 0, ("Got unexpected negative value %d", error)); 1627 return (error == 0 ? len : -error); 1628 } 1629 1630 struct sbuf * 1631 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length, 1632 struct sysctl_req *req) 1633 { 1634 1635 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN); 1636 sbuf_set_drain(s, sbuf_sysctl_drain, req); 1637 return (s); 1638 } 1639