Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sysctl.c
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1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Mike Karels at Berkeley Software Design, Inc. 7 * 8 * Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD 9 * project, to make these variables more userfriendly. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)kern_sysctl.c 8.4 (Berkeley) 4/14/94 36 */ 37 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD: releng/9.2/sys/kern/kern_sysctl.c 248034 2013-03-08 11:25:52Z marius $"); 40 41 #include "opt_capsicum.h" 42 #include "opt_compat.h" 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/fail.h> 47 #include <sys/systm.h> 48 #include <sys/capability.h> 49 #include <sys/kernel.h> 50 #include <sys/sysctl.h> 51 #include <sys/malloc.h> 52 #include <sys/priv.h> 53 #include <sys/proc.h> 54 #include <sys/jail.h> 55 #include <sys/lock.h> 56 #include <sys/mutex.h> 57 #include <sys/sbuf.h> 58 #include <sys/sx.h> 59 #include <sys/sysproto.h> 60 #include <sys/uio.h> 61 #ifdef KTRACE 62 #include <sys/ktrace.h> 63 #endif 64 65 #include <net/vnet.h> 66 67 #include <security/mac/mac_framework.h> 68 69 #include <vm/vm.h> 70 #include <vm/vm_extern.h> 71 72 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic"); 73 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids"); 74 static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer"); 75 76 /* 77 * The sysctllock protects the MIB tree. It also protects sysctl 78 * contexts used with dynamic sysctls. The sysctl_register_oid() and 79 * sysctl_unregister_oid() routines require the sysctllock to already 80 * be held, so the sysctl_lock() and sysctl_unlock() routines are 81 * provided for the few places in the kernel which need to use that 82 * API rather than using the dynamic API. Use of the dynamic API is 83 * strongly encouraged for most code. 84 * 85 * The sysctlmemlock is used to limit the amount of user memory wired for 86 * sysctl requests. This is implemented by serializing any userland 87 * sysctl requests larger than a single page via an exclusive lock. 88 */ 89 static struct sx sysctllock; 90 static struct sx sysctlmemlock; 91 92 #define SYSCTL_XLOCK() sx_xlock(&sysctllock) 93 #define SYSCTL_XUNLOCK() sx_xunlock(&sysctllock) 94 #define SYSCTL_ASSERT_XLOCKED() sx_assert(&sysctllock, SA_XLOCKED) 95 #define SYSCTL_INIT() sx_init(&sysctllock, "sysctl lock") 96 #define SYSCTL_SLEEP(ch, wmesg, timo) \ 97 sx_sleep(ch, &sysctllock, 0, wmesg, timo) 98 99 static int sysctl_root(SYSCTL_HANDLER_ARGS); 100 101 struct sysctl_oid_list sysctl__children; /* root list */ 102 103 static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, 104 int recurse); 105 106 static struct sysctl_oid * 107 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list) 108 { 109 struct sysctl_oid *oidp; 110 111 SYSCTL_ASSERT_XLOCKED(); 112 SLIST_FOREACH(oidp, list, oid_link) { 113 if (strcmp(oidp->oid_name, name) == 0) { 114 return (oidp); 115 } 116 } 117 return (NULL); 118 } 119 120 /* 121 * Initialization of the MIB tree. 122 * 123 * Order by number in each list. 124 */ 125 void 126 sysctl_lock(void) 127 { 128 129 SYSCTL_XLOCK(); 130 } 131 132 void 133 sysctl_unlock(void) 134 { 135 136 SYSCTL_XUNLOCK(); 137 } 138 139 void 140 sysctl_register_oid(struct sysctl_oid *oidp) 141 { 142 struct sysctl_oid_list *parent = oidp->oid_parent; 143 struct sysctl_oid *p; 144 struct sysctl_oid *q; 145 146 /* 147 * First check if another oid with the same name already 148 * exists in the parent's list. 149 */ 150 SYSCTL_ASSERT_XLOCKED(); 151 p = sysctl_find_oidname(oidp->oid_name, parent); 152 if (p != NULL) { 153 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 154 p->oid_refcnt++; 155 return; 156 } else { 157 printf("can't re-use a leaf (%s)!\n", p->oid_name); 158 return; 159 } 160 } 161 /* 162 * If this oid has a number OID_AUTO, give it a number which 163 * is greater than any current oid. 164 * NOTE: DO NOT change the starting value here, change it in 165 * <sys/sysctl.h>, and make sure it is at least 256 to 166 * accomodate e.g. net.inet.raw as a static sysctl node. 167 */ 168 if (oidp->oid_number == OID_AUTO) { 169 static int newoid = CTL_AUTO_START; 170 171 oidp->oid_number = newoid++; 172 if (newoid == 0x7fffffff) 173 panic("out of oids"); 174 } 175 #if 0 176 else if (oidp->oid_number >= CTL_AUTO_START) { 177 /* do not panic; this happens when unregistering sysctl sets */ 178 printf("static sysctl oid too high: %d", oidp->oid_number); 179 } 180 #endif 181 182 /* 183 * Insert the oid into the parent's list in order. 184 */ 185 q = NULL; 186 SLIST_FOREACH(p, parent, oid_link) { 187 if (oidp->oid_number < p->oid_number) 188 break; 189 q = p; 190 } 191 if (q) 192 SLIST_INSERT_AFTER(q, oidp, oid_link); 193 else 194 SLIST_INSERT_HEAD(parent, oidp, oid_link); 195 } 196 197 void 198 sysctl_unregister_oid(struct sysctl_oid *oidp) 199 { 200 struct sysctl_oid *p; 201 int error; 202 203 SYSCTL_ASSERT_XLOCKED(); 204 error = ENOENT; 205 if (oidp->oid_number == OID_AUTO) { 206 error = EINVAL; 207 } else { 208 SLIST_FOREACH(p, oidp->oid_parent, oid_link) { 209 if (p == oidp) { 210 SLIST_REMOVE(oidp->oid_parent, oidp, 211 sysctl_oid, oid_link); 212 error = 0; 213 break; 214 } 215 } 216 } 217 218 /* 219 * This can happen when a module fails to register and is 220 * being unloaded afterwards. It should not be a panic() 221 * for normal use. 222 */ 223 if (error) 224 printf("%s: failed to unregister sysctl\n", __func__); 225 } 226 227 /* Initialize a new context to keep track of dynamically added sysctls. */ 228 int 229 sysctl_ctx_init(struct sysctl_ctx_list *c) 230 { 231 232 if (c == NULL) { 233 return (EINVAL); 234 } 235 236 /* 237 * No locking here, the caller is responsible for not adding 238 * new nodes to a context until after this function has 239 * returned. 240 */ 241 TAILQ_INIT(c); 242 return (0); 243 } 244 245 /* Free the context, and destroy all dynamic oids registered in this context */ 246 int 247 sysctl_ctx_free(struct sysctl_ctx_list *clist) 248 { 249 struct sysctl_ctx_entry *e, *e1; 250 int error; 251 252 error = 0; 253 /* 254 * First perform a "dry run" to check if it's ok to remove oids. 255 * XXX FIXME 256 * XXX This algorithm is a hack. But I don't know any 257 * XXX better solution for now... 258 */ 259 SYSCTL_XLOCK(); 260 TAILQ_FOREACH(e, clist, link) { 261 error = sysctl_remove_oid_locked(e->entry, 0, 0); 262 if (error) 263 break; 264 } 265 /* 266 * Restore deregistered entries, either from the end, 267 * or from the place where error occured. 268 * e contains the entry that was not unregistered 269 */ 270 if (error) 271 e1 = TAILQ_PREV(e, sysctl_ctx_list, link); 272 else 273 e1 = TAILQ_LAST(clist, sysctl_ctx_list); 274 while (e1 != NULL) { 275 sysctl_register_oid(e1->entry); 276 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link); 277 } 278 if (error) { 279 SYSCTL_XUNLOCK(); 280 return(EBUSY); 281 } 282 /* Now really delete the entries */ 283 e = TAILQ_FIRST(clist); 284 while (e != NULL) { 285 e1 = TAILQ_NEXT(e, link); 286 error = sysctl_remove_oid_locked(e->entry, 1, 0); 287 if (error) 288 panic("sysctl_remove_oid: corrupt tree, entry: %s", 289 e->entry->oid_name); 290 free(e, M_SYSCTLOID); 291 e = e1; 292 } 293 SYSCTL_XUNLOCK(); 294 return (error); 295 } 296 297 /* Add an entry to the context */ 298 struct sysctl_ctx_entry * 299 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 300 { 301 struct sysctl_ctx_entry *e; 302 303 SYSCTL_ASSERT_XLOCKED(); 304 if (clist == NULL || oidp == NULL) 305 return(NULL); 306 e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK); 307 e->entry = oidp; 308 TAILQ_INSERT_HEAD(clist, e, link); 309 return (e); 310 } 311 312 /* Find an entry in the context */ 313 struct sysctl_ctx_entry * 314 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 315 { 316 struct sysctl_ctx_entry *e; 317 318 SYSCTL_ASSERT_XLOCKED(); 319 if (clist == NULL || oidp == NULL) 320 return(NULL); 321 TAILQ_FOREACH(e, clist, link) { 322 if(e->entry == oidp) 323 return(e); 324 } 325 return (e); 326 } 327 328 /* 329 * Delete an entry from the context. 330 * NOTE: this function doesn't free oidp! You have to remove it 331 * with sysctl_remove_oid(). 332 */ 333 int 334 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 335 { 336 struct sysctl_ctx_entry *e; 337 338 if (clist == NULL || oidp == NULL) 339 return (EINVAL); 340 SYSCTL_XLOCK(); 341 e = sysctl_ctx_entry_find(clist, oidp); 342 if (e != NULL) { 343 TAILQ_REMOVE(clist, e, link); 344 SYSCTL_XUNLOCK(); 345 free(e, M_SYSCTLOID); 346 return (0); 347 } else { 348 SYSCTL_XUNLOCK(); 349 return (ENOENT); 350 } 351 } 352 353 /* 354 * Remove dynamically created sysctl trees. 355 * oidp - top of the tree to be removed 356 * del - if 0 - just deregister, otherwise free up entries as well 357 * recurse - if != 0 traverse the subtree to be deleted 358 */ 359 int 360 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse) 361 { 362 int error; 363 364 SYSCTL_XLOCK(); 365 error = sysctl_remove_oid_locked(oidp, del, recurse); 366 SYSCTL_XUNLOCK(); 367 return (error); 368 } 369 370 int 371 sysctl_remove_name(struct sysctl_oid *parent, const char *name, 372 int del, int recurse) 373 { 374 struct sysctl_oid *p, *tmp; 375 int error; 376 377 error = ENOENT; 378 SYSCTL_XLOCK(); 379 SLIST_FOREACH_SAFE(p, SYSCTL_CHILDREN(parent), oid_link, tmp) { 380 if (strcmp(p->oid_name, name) == 0) { 381 error = sysctl_remove_oid_locked(p, del, recurse); 382 break; 383 } 384 } 385 SYSCTL_XUNLOCK(); 386 387 return (error); 388 } 389 390 391 static int 392 sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse) 393 { 394 struct sysctl_oid *p, *tmp; 395 int error; 396 397 SYSCTL_ASSERT_XLOCKED(); 398 if (oidp == NULL) 399 return(EINVAL); 400 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) { 401 printf("can't remove non-dynamic nodes!\n"); 402 return (EINVAL); 403 } 404 /* 405 * WARNING: normal method to do this should be through 406 * sysctl_ctx_free(). Use recursing as the last resort 407 * method to purge your sysctl tree of leftovers... 408 * However, if some other code still references these nodes, 409 * it will panic. 410 */ 411 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 412 if (oidp->oid_refcnt == 1) { 413 SLIST_FOREACH_SAFE(p, 414 SYSCTL_CHILDREN(oidp), oid_link, tmp) { 415 if (!recurse) 416 return (ENOTEMPTY); 417 error = sysctl_remove_oid_locked(p, del, 418 recurse); 419 if (error) 420 return (error); 421 } 422 if (del) 423 free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID); 424 } 425 } 426 if (oidp->oid_refcnt > 1 ) { 427 oidp->oid_refcnt--; 428 } else { 429 if (oidp->oid_refcnt == 0) { 430 printf("Warning: bad oid_refcnt=%u (%s)!\n", 431 oidp->oid_refcnt, oidp->oid_name); 432 return (EINVAL); 433 } 434 sysctl_unregister_oid(oidp); 435 if (del) { 436 /* 437 * Wait for all threads running the handler to drain. 438 * This preserves the previous behavior when the 439 * sysctl lock was held across a handler invocation, 440 * and is necessary for module unload correctness. 441 */ 442 while (oidp->oid_running > 0) { 443 oidp->oid_kind |= CTLFLAG_DYING; 444 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0); 445 } 446 if (oidp->oid_descr) 447 free(__DECONST(char *, oidp->oid_descr), 448 M_SYSCTLOID); 449 free(__DECONST(char *, oidp->oid_name), M_SYSCTLOID); 450 free(oidp, M_SYSCTLOID); 451 } 452 } 453 return (0); 454 } 455 /* 456 * Create new sysctls at run time. 457 * clist may point to a valid context initialized with sysctl_ctx_init(). 458 */ 459 struct sysctl_oid * 460 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, 461 int number, const char *name, int kind, void *arg1, intptr_t arg2, 462 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr) 463 { 464 struct sysctl_oid *oidp; 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 oidp->oid_name = strdup(name, M_SYSCTLOID); 492 oidp->oid_handler = handler; 493 oidp->oid_kind = CTLFLAG_DYN | kind; 494 if ((kind & CTLTYPE) == CTLTYPE_NODE) { 495 /* Allocate space for children */ 496 SYSCTL_CHILDREN_SET(oidp, malloc(sizeof(struct sysctl_oid_list), 497 M_SYSCTLOID, M_WAITOK)); 498 SLIST_INIT(SYSCTL_CHILDREN(oidp)); 499 oidp->oid_arg2 = arg2; 500 } else { 501 oidp->oid_arg1 = arg1; 502 oidp->oid_arg2 = arg2; 503 } 504 oidp->oid_fmt = fmt; 505 if (descr) 506 oidp->oid_descr = strdup(descr, M_SYSCTLOID); 507 /* Update the context, if used */ 508 if (clist != NULL) 509 sysctl_ctx_entry_add(clist, oidp); 510 /* Register this oid */ 511 sysctl_register_oid(oidp); 512 SYSCTL_XUNLOCK(); 513 return (oidp); 514 } 515 516 /* 517 * Rename an existing oid. 518 */ 519 void 520 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) 521 { 522 char *newname; 523 char *oldname; 524 525 newname = strdup(name, M_SYSCTLOID); 526 SYSCTL_XLOCK(); 527 oldname = __DECONST(char *, oidp->oid_name); 528 oidp->oid_name = newname; 529 SYSCTL_XUNLOCK(); 530 free(oldname, M_SYSCTLOID); 531 } 532 533 /* 534 * Reparent an existing oid. 535 */ 536 int 537 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent) 538 { 539 struct sysctl_oid *oidp; 540 541 SYSCTL_XLOCK(); 542 if (oid->oid_parent == parent) { 543 SYSCTL_XUNLOCK(); 544 return (0); 545 } 546 oidp = sysctl_find_oidname(oid->oid_name, parent); 547 if (oidp != NULL) { 548 SYSCTL_XUNLOCK(); 549 return (EEXIST); 550 } 551 sysctl_unregister_oid(oid); 552 oid->oid_parent = parent; 553 oid->oid_number = OID_AUTO; 554 sysctl_register_oid(oid); 555 SYSCTL_XUNLOCK(); 556 return (0); 557 } 558 559 /* 560 * Register the kernel's oids on startup. 561 */ 562 SET_DECLARE(sysctl_set, struct sysctl_oid); 563 564 static void 565 sysctl_register_all(void *arg) 566 { 567 struct sysctl_oid **oidp; 568 569 sx_init(&sysctlmemlock, "sysctl mem"); 570 SYSCTL_INIT(); 571 SYSCTL_XLOCK(); 572 SET_FOREACH(oidp, sysctl_set) 573 sysctl_register_oid(*oidp); 574 SYSCTL_XUNLOCK(); 575 } 576 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0); 577 578 /* 579 * "Staff-functions" 580 * 581 * These functions implement a presently undocumented interface 582 * used by the sysctl program to walk the tree, and get the type 583 * so it can print the value. 584 * This interface is under work and consideration, and should probably 585 * be killed with a big axe by the first person who can find the time. 586 * (be aware though, that the proper interface isn't as obvious as it 587 * may seem, there are various conflicting requirements. 588 * 589 * {0,0} printf the entire MIB-tree. 590 * {0,1,...} return the name of the "..." OID. 591 * {0,2,...} return the next OID. 592 * {0,3} return the OID of the name in "new" 593 * {0,4,...} return the kind & format info for the "..." OID. 594 * {0,5,...} return the description the "..." OID. 595 */ 596 597 #ifdef SYSCTL_DEBUG 598 static void 599 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 600 { 601 int k; 602 struct sysctl_oid *oidp; 603 604 SYSCTL_ASSERT_XLOCKED(); 605 SLIST_FOREACH(oidp, l, oid_link) { 606 607 for (k=0; k<i; k++) 608 printf(" "); 609 610 printf("%d %s ", oidp->oid_number, oidp->oid_name); 611 612 printf("%c%c", 613 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 614 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 615 616 if (oidp->oid_handler) 617 printf(" *Handler"); 618 619 switch (oidp->oid_kind & CTLTYPE) { 620 case CTLTYPE_NODE: 621 printf(" Node\n"); 622 if (!oidp->oid_handler) { 623 sysctl_sysctl_debug_dump_node( 624 oidp->oid_arg1, i+2); 625 } 626 break; 627 case CTLTYPE_INT: printf(" Int\n"); break; 628 case CTLTYPE_UINT: printf(" u_int\n"); break; 629 case CTLTYPE_LONG: printf(" Long\n"); break; 630 case CTLTYPE_ULONG: printf(" u_long\n"); break; 631 case CTLTYPE_STRING: printf(" String\n"); break; 632 case CTLTYPE_U64: printf(" uint64_t\n"); break; 633 case CTLTYPE_S64: printf(" int64_t\n"); break; 634 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break; 635 default: printf("\n"); 636 } 637 638 } 639 } 640 641 static int 642 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 643 { 644 int error; 645 646 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 647 if (error) 648 return (error); 649 SYSCTL_XLOCK(); 650 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 651 SYSCTL_XUNLOCK(); 652 return (ENOENT); 653 } 654 655 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD, 656 0, 0, sysctl_sysctl_debug, "-", ""); 657 #endif 658 659 static int 660 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 661 { 662 int *name = (int *) arg1; 663 u_int namelen = arg2; 664 int error = 0; 665 struct sysctl_oid *oid; 666 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 667 char buf[10]; 668 669 SYSCTL_XLOCK(); 670 while (namelen) { 671 if (!lsp) { 672 snprintf(buf,sizeof(buf),"%d",*name); 673 if (req->oldidx) 674 error = SYSCTL_OUT(req, ".", 1); 675 if (!error) 676 error = SYSCTL_OUT(req, buf, strlen(buf)); 677 if (error) 678 goto out; 679 namelen--; 680 name++; 681 continue; 682 } 683 lsp2 = 0; 684 SLIST_FOREACH(oid, lsp, oid_link) { 685 if (oid->oid_number != *name) 686 continue; 687 688 if (req->oldidx) 689 error = SYSCTL_OUT(req, ".", 1); 690 if (!error) 691 error = SYSCTL_OUT(req, oid->oid_name, 692 strlen(oid->oid_name)); 693 if (error) 694 goto out; 695 696 namelen--; 697 name++; 698 699 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 700 break; 701 702 if (oid->oid_handler) 703 break; 704 705 lsp2 = SYSCTL_CHILDREN(oid); 706 break; 707 } 708 lsp = lsp2; 709 } 710 error = SYSCTL_OUT(req, "", 1); 711 out: 712 SYSCTL_XUNLOCK(); 713 return (error); 714 } 715 716 /* 717 * XXXRW/JA: Shouldn't return name data for nodes that we don't permit in 718 * capability mode. 719 */ 720 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_CAPRD, 721 sysctl_sysctl_name, ""); 722 723 static int 724 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 725 int *next, int *len, int level, struct sysctl_oid **oidpp) 726 { 727 struct sysctl_oid *oidp; 728 729 SYSCTL_ASSERT_XLOCKED(); 730 *len = level; 731 SLIST_FOREACH(oidp, lsp, oid_link) { 732 *next = oidp->oid_number; 733 *oidpp = oidp; 734 735 if (oidp->oid_kind & CTLFLAG_SKIP) 736 continue; 737 738 if (!namelen) { 739 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 740 return (0); 741 if (oidp->oid_handler) 742 /* We really should call the handler here...*/ 743 return (0); 744 lsp = SYSCTL_CHILDREN(oidp); 745 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 746 len, level+1, oidpp)) 747 return (0); 748 goto emptynode; 749 } 750 751 if (oidp->oid_number < *name) 752 continue; 753 754 if (oidp->oid_number > *name) { 755 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 756 return (0); 757 if (oidp->oid_handler) 758 return (0); 759 lsp = SYSCTL_CHILDREN(oidp); 760 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 761 next+1, len, level+1, oidpp)) 762 return (0); 763 goto next; 764 } 765 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 766 continue; 767 768 if (oidp->oid_handler) 769 continue; 770 771 lsp = SYSCTL_CHILDREN(oidp); 772 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 773 len, level+1, oidpp)) 774 return (0); 775 next: 776 namelen = 1; 777 emptynode: 778 *len = level; 779 } 780 return (1); 781 } 782 783 static int 784 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 785 { 786 int *name = (int *) arg1; 787 u_int namelen = arg2; 788 int i, j, error; 789 struct sysctl_oid *oid; 790 struct sysctl_oid_list *lsp = &sysctl__children; 791 int newoid[CTL_MAXNAME]; 792 793 SYSCTL_XLOCK(); 794 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 795 SYSCTL_XUNLOCK(); 796 if (i) 797 return (ENOENT); 798 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 799 return (error); 800 } 801 802 /* 803 * XXXRW/JA: Shouldn't return next data for nodes that we don't permit in 804 * capability mode. 805 */ 806 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_CAPRD, 807 sysctl_sysctl_next, ""); 808 809 static int 810 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) 811 { 812 struct sysctl_oid *oidp; 813 struct sysctl_oid_list *lsp = &sysctl__children; 814 char *p; 815 816 SYSCTL_ASSERT_XLOCKED(); 817 818 for (*len = 0; *len < CTL_MAXNAME;) { 819 p = strsep(&name, "."); 820 821 oidp = SLIST_FIRST(lsp); 822 for (;; oidp = SLIST_NEXT(oidp, oid_link)) { 823 if (oidp == NULL) 824 return (ENOENT); 825 if (strcmp(p, oidp->oid_name) == 0) 826 break; 827 } 828 *oid++ = oidp->oid_number; 829 (*len)++; 830 831 if (name == NULL || *name == '\0') { 832 if (oidpp) 833 *oidpp = oidp; 834 return (0); 835 } 836 837 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 838 break; 839 840 if (oidp->oid_handler) 841 break; 842 843 lsp = SYSCTL_CHILDREN(oidp); 844 } 845 return (ENOENT); 846 } 847 848 static int 849 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 850 { 851 char *p; 852 int error, oid[CTL_MAXNAME], len = 0; 853 struct sysctl_oid *op = 0; 854 855 if (!req->newlen) 856 return (ENOENT); 857 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 858 return (ENAMETOOLONG); 859 860 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK); 861 862 error = SYSCTL_IN(req, p, req->newlen); 863 if (error) { 864 free(p, M_SYSCTL); 865 return (error); 866 } 867 868 p [req->newlen] = '\0'; 869 870 SYSCTL_XLOCK(); 871 error = name2oid(p, oid, &len, &op); 872 SYSCTL_XUNLOCK(); 873 874 free(p, M_SYSCTL); 875 876 if (error) 877 return (error); 878 879 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 880 return (error); 881 } 882 883 /* 884 * XXXRW/JA: Shouldn't return name2oid data for nodes that we don't permit in 885 * capability mode. 886 */ 887 SYSCTL_PROC(_sysctl, 3, name2oid, 888 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE 889 | CTLFLAG_CAPRW, 0, 0, sysctl_sysctl_name2oid, "I", ""); 890 891 static int 892 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 893 { 894 struct sysctl_oid *oid; 895 int error; 896 897 SYSCTL_XLOCK(); 898 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 899 if (error) 900 goto out; 901 902 if (oid->oid_fmt == NULL) { 903 error = ENOENT; 904 goto out; 905 } 906 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 907 if (error) 908 goto out; 909 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 910 out: 911 SYSCTL_XUNLOCK(); 912 return (error); 913 } 914 915 916 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD, 917 sysctl_sysctl_oidfmt, ""); 918 919 static int 920 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 921 { 922 struct sysctl_oid *oid; 923 int error; 924 925 SYSCTL_XLOCK(); 926 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 927 if (error) 928 goto out; 929 930 if (oid->oid_descr == NULL) { 931 error = ENOENT; 932 goto out; 933 } 934 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 935 out: 936 SYSCTL_XUNLOCK(); 937 return (error); 938 } 939 940 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_CAPRD, 941 sysctl_sysctl_oiddescr, ""); 942 943 /* 944 * Default "handler" functions. 945 */ 946 947 /* 948 * Handle an int, signed or unsigned. 949 * Two cases: 950 * a variable: point arg1 at it. 951 * a constant: pass it in arg2. 952 */ 953 954 int 955 sysctl_handle_int(SYSCTL_HANDLER_ARGS) 956 { 957 int tmpout, error = 0; 958 959 /* 960 * Attempt to get a coherent snapshot by making a copy of the data. 961 */ 962 if (arg1) 963 tmpout = *(int *)arg1; 964 else 965 tmpout = arg2; 966 error = SYSCTL_OUT(req, &tmpout, sizeof(int)); 967 968 if (error || !req->newptr) 969 return (error); 970 971 if (!arg1) 972 error = EPERM; 973 else 974 error = SYSCTL_IN(req, arg1, sizeof(int)); 975 return (error); 976 } 977 978 /* 979 * Based on on sysctl_handle_int() convert milliseconds into ticks. 980 * Note: this is used by TCP. 981 */ 982 983 int 984 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) 985 { 986 int error, s, tt; 987 988 tt = *(int *)arg1; 989 s = (int)((int64_t)tt * 1000 / hz); 990 991 error = sysctl_handle_int(oidp, &s, 0, req); 992 if (error || !req->newptr) 993 return (error); 994 995 tt = (int)((int64_t)s * hz / 1000); 996 if (tt < 1) 997 return (EINVAL); 998 999 *(int *)arg1 = tt; 1000 return (0); 1001 } 1002 1003 1004 /* 1005 * Handle a long, signed or unsigned. 1006 * Two cases: 1007 * a variable: point arg1 at it. 1008 * a constant: pass it in arg2. 1009 */ 1010 1011 int 1012 sysctl_handle_long(SYSCTL_HANDLER_ARGS) 1013 { 1014 int error = 0; 1015 long tmplong; 1016 #ifdef SCTL_MASK32 1017 int tmpint; 1018 #endif 1019 1020 /* 1021 * Attempt to get a coherent snapshot by making a copy of the data. 1022 */ 1023 if (arg1) 1024 tmplong = *(long *)arg1; 1025 else 1026 tmplong = arg2; 1027 #ifdef SCTL_MASK32 1028 if (req->flags & SCTL_MASK32) { 1029 tmpint = tmplong; 1030 error = SYSCTL_OUT(req, &tmpint, sizeof(int)); 1031 } else 1032 #endif 1033 error = SYSCTL_OUT(req, &tmplong, sizeof(long)); 1034 1035 if (error || !req->newptr) 1036 return (error); 1037 1038 if (!arg1) 1039 error = EPERM; 1040 #ifdef SCTL_MASK32 1041 else if (req->flags & SCTL_MASK32) { 1042 error = SYSCTL_IN(req, &tmpint, sizeof(int)); 1043 *(long *)arg1 = (long)tmpint; 1044 } 1045 #endif 1046 else 1047 error = SYSCTL_IN(req, arg1, sizeof(long)); 1048 return (error); 1049 } 1050 1051 /* 1052 * Handle a 64 bit int, signed or unsigned. 1053 * Two cases: 1054 * a variable: point arg1 at it. 1055 * a constant: pass it in arg2. 1056 */ 1057 int 1058 sysctl_handle_64(SYSCTL_HANDLER_ARGS) 1059 { 1060 int error = 0; 1061 uint64_t tmpout; 1062 1063 /* 1064 * Attempt to get a coherent snapshot by making a copy of the data. 1065 */ 1066 if (arg1) 1067 tmpout = *(uint64_t *)arg1; 1068 else 1069 tmpout = arg2; 1070 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t)); 1071 1072 if (error || !req->newptr) 1073 return (error); 1074 1075 if (!arg1) 1076 error = EPERM; 1077 else 1078 error = SYSCTL_IN(req, arg1, sizeof(uint64_t)); 1079 return (error); 1080 } 1081 1082 /* 1083 * Handle our generic '\0' terminated 'C' string. 1084 * Two cases: 1085 * a variable string: point arg1 at it, arg2 is max length. 1086 * a constant string: point arg1 at it, arg2 is zero. 1087 */ 1088 1089 int 1090 sysctl_handle_string(SYSCTL_HANDLER_ARGS) 1091 { 1092 int error=0; 1093 char *tmparg; 1094 size_t outlen; 1095 1096 /* 1097 * Attempt to get a coherent snapshot by copying to a 1098 * temporary kernel buffer. 1099 */ 1100 retry: 1101 outlen = strlen((char *)arg1)+1; 1102 tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK); 1103 1104 if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) { 1105 free(tmparg, M_SYSCTLTMP); 1106 goto retry; 1107 } 1108 1109 error = SYSCTL_OUT(req, tmparg, outlen); 1110 free(tmparg, M_SYSCTLTMP); 1111 1112 if (error || !req->newptr) 1113 return (error); 1114 1115 if ((req->newlen - req->newidx) >= arg2) { 1116 error = EINVAL; 1117 } else { 1118 arg2 = (req->newlen - req->newidx); 1119 error = SYSCTL_IN(req, arg1, arg2); 1120 ((char *)arg1)[arg2] = '\0'; 1121 } 1122 1123 return (error); 1124 } 1125 1126 /* 1127 * Handle any kind of opaque data. 1128 * arg1 points to it, arg2 is the size. 1129 */ 1130 1131 int 1132 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 1133 { 1134 int error, tries; 1135 u_int generation; 1136 struct sysctl_req req2; 1137 1138 /* 1139 * Attempt to get a coherent snapshot, by using the thread 1140 * pre-emption counter updated from within mi_switch() to 1141 * determine if we were pre-empted during a bcopy() or 1142 * copyout(). Make 3 attempts at doing this before giving up. 1143 * If we encounter an error, stop immediately. 1144 */ 1145 tries = 0; 1146 req2 = *req; 1147 retry: 1148 generation = curthread->td_generation; 1149 error = SYSCTL_OUT(req, arg1, arg2); 1150 if (error) 1151 return (error); 1152 tries++; 1153 if (generation != curthread->td_generation && tries < 3) { 1154 *req = req2; 1155 goto retry; 1156 } 1157 1158 error = SYSCTL_IN(req, arg1, arg2); 1159 1160 return (error); 1161 } 1162 1163 /* 1164 * Transfer functions to/from kernel space. 1165 * XXX: rather untested at this point 1166 */ 1167 static int 1168 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 1169 { 1170 size_t i = 0; 1171 1172 if (req->oldptr) { 1173 i = l; 1174 if (req->oldlen <= req->oldidx) 1175 i = 0; 1176 else 1177 if (i > req->oldlen - req->oldidx) 1178 i = req->oldlen - req->oldidx; 1179 if (i > 0) 1180 bcopy(p, (char *)req->oldptr + req->oldidx, i); 1181 } 1182 req->oldidx += l; 1183 if (req->oldptr && i != l) 1184 return (ENOMEM); 1185 return (0); 1186 } 1187 1188 static int 1189 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 1190 { 1191 if (!req->newptr) 1192 return (0); 1193 if (req->newlen - req->newidx < l) 1194 return (EINVAL); 1195 bcopy((char *)req->newptr + req->newidx, p, l); 1196 req->newidx += l; 1197 return (0); 1198 } 1199 1200 int 1201 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1202 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags) 1203 { 1204 int error = 0; 1205 struct sysctl_req req; 1206 1207 bzero(&req, sizeof req); 1208 1209 req.td = td; 1210 req.flags = flags; 1211 1212 if (oldlenp) { 1213 req.oldlen = *oldlenp; 1214 } 1215 req.validlen = req.oldlen; 1216 1217 if (old) { 1218 req.oldptr= old; 1219 } 1220 1221 if (new != NULL) { 1222 req.newlen = newlen; 1223 req.newptr = new; 1224 } 1225 1226 req.oldfunc = sysctl_old_kernel; 1227 req.newfunc = sysctl_new_kernel; 1228 req.lock = REQ_UNWIRED; 1229 1230 SYSCTL_XLOCK(); 1231 error = sysctl_root(0, name, namelen, &req); 1232 SYSCTL_XUNLOCK(); 1233 1234 if (req.lock == REQ_WIRED && req.validlen > 0) 1235 vsunlock(req.oldptr, req.validlen); 1236 1237 if (error && error != ENOMEM) 1238 return (error); 1239 1240 if (retval) { 1241 if (req.oldptr && req.oldidx > req.validlen) 1242 *retval = req.validlen; 1243 else 1244 *retval = req.oldidx; 1245 } 1246 return (error); 1247 } 1248 1249 int 1250 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp, 1251 void *new, size_t newlen, size_t *retval, int flags) 1252 { 1253 int oid[CTL_MAXNAME]; 1254 size_t oidlen, plen; 1255 int error; 1256 1257 oid[0] = 0; /* sysctl internal magic */ 1258 oid[1] = 3; /* name2oid */ 1259 oidlen = sizeof(oid); 1260 1261 error = kernel_sysctl(td, oid, 2, oid, &oidlen, 1262 (void *)name, strlen(name), &plen, flags); 1263 if (error) 1264 return (error); 1265 1266 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp, 1267 new, newlen, retval, flags); 1268 return (error); 1269 } 1270 1271 /* 1272 * Transfer function to/from user space. 1273 */ 1274 static int 1275 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1276 { 1277 size_t i, len, origidx; 1278 int error; 1279 1280 origidx = req->oldidx; 1281 req->oldidx += l; 1282 if (req->oldptr == NULL) 1283 return (0); 1284 /* 1285 * If we have not wired the user supplied buffer and we are currently 1286 * holding locks, drop a witness warning, as it's possible that 1287 * write operations to the user page can sleep. 1288 */ 1289 if (req->lock != REQ_WIRED) 1290 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1291 "sysctl_old_user()"); 1292 i = l; 1293 len = req->validlen; 1294 if (len <= origidx) 1295 i = 0; 1296 else { 1297 if (i > len - origidx) 1298 i = len - origidx; 1299 if (req->lock == REQ_WIRED) { 1300 error = copyout_nofault(p, (char *)req->oldptr + 1301 origidx, i); 1302 } else 1303 error = copyout(p, (char *)req->oldptr + origidx, i); 1304 if (error != 0) 1305 return (error); 1306 } 1307 if (i < l) 1308 return (ENOMEM); 1309 return (0); 1310 } 1311 1312 static int 1313 sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1314 { 1315 int error; 1316 1317 if (!req->newptr) 1318 return (0); 1319 if (req->newlen - req->newidx < l) 1320 return (EINVAL); 1321 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1322 "sysctl_new_user()"); 1323 error = copyin((char *)req->newptr + req->newidx, p, l); 1324 req->newidx += l; 1325 return (error); 1326 } 1327 1328 /* 1329 * Wire the user space destination buffer. If set to a value greater than 1330 * zero, the len parameter limits the maximum amount of wired memory. 1331 */ 1332 int 1333 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len) 1334 { 1335 int ret; 1336 size_t wiredlen; 1337 1338 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen; 1339 ret = 0; 1340 if (req->lock != REQ_WIRED && req->oldptr && 1341 req->oldfunc == sysctl_old_user) { 1342 if (wiredlen != 0) { 1343 ret = vslock(req->oldptr, wiredlen); 1344 if (ret != 0) { 1345 if (ret != ENOMEM) 1346 return (ret); 1347 wiredlen = 0; 1348 } 1349 } 1350 req->lock = REQ_WIRED; 1351 req->validlen = wiredlen; 1352 } 1353 return (0); 1354 } 1355 1356 int 1357 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1358 int *nindx, struct sysctl_req *req) 1359 { 1360 struct sysctl_oid_list *lsp; 1361 struct sysctl_oid *oid; 1362 int indx; 1363 1364 SYSCTL_ASSERT_XLOCKED(); 1365 lsp = &sysctl__children; 1366 indx = 0; 1367 while (indx < CTL_MAXNAME) { 1368 SLIST_FOREACH(oid, lsp, oid_link) { 1369 if (oid->oid_number == name[indx]) 1370 break; 1371 } 1372 if (oid == NULL) 1373 return (ENOENT); 1374 1375 indx++; 1376 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1377 if (oid->oid_handler != NULL || indx == namelen) { 1378 *noid = oid; 1379 if (nindx != NULL) 1380 *nindx = indx; 1381 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1382 ("%s found DYING node %p", __func__, oid)); 1383 return (0); 1384 } 1385 lsp = SYSCTL_CHILDREN(oid); 1386 } else if (indx == namelen) { 1387 *noid = oid; 1388 if (nindx != NULL) 1389 *nindx = indx; 1390 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1391 ("%s found DYING node %p", __func__, oid)); 1392 return (0); 1393 } else { 1394 return (ENOTDIR); 1395 } 1396 } 1397 return (ENOENT); 1398 } 1399 1400 /* 1401 * Traverse our tree, and find the right node, execute whatever it points 1402 * to, and return the resulting error code. 1403 */ 1404 1405 static int 1406 sysctl_root(SYSCTL_HANDLER_ARGS) 1407 { 1408 struct sysctl_oid *oid; 1409 int error, indx, lvl; 1410 1411 SYSCTL_ASSERT_XLOCKED(); 1412 1413 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1414 if (error) 1415 return (error); 1416 1417 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1418 /* 1419 * You can't call a sysctl when it's a node, but has 1420 * no handler. Inform the user that it's a node. 1421 * The indx may or may not be the same as namelen. 1422 */ 1423 if (oid->oid_handler == NULL) 1424 return (EISDIR); 1425 } 1426 1427 /* Is this sysctl writable? */ 1428 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) 1429 return (EPERM); 1430 1431 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL")); 1432 1433 #ifdef CAPABILITY_MODE 1434 /* 1435 * If the process is in capability mode, then don't permit reading or 1436 * writing unless specifically granted for the node. 1437 */ 1438 if (IN_CAPABILITY_MODE(req->td)) { 1439 if (req->oldptr && !(oid->oid_kind & CTLFLAG_CAPRD)) 1440 return (EPERM); 1441 if (req->newptr && !(oid->oid_kind & CTLFLAG_CAPWR)) 1442 return (EPERM); 1443 } 1444 #endif 1445 1446 /* Is this sysctl sensitive to securelevels? */ 1447 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) { 1448 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE; 1449 error = securelevel_gt(req->td->td_ucred, lvl); 1450 if (error) 1451 return (error); 1452 } 1453 1454 /* Is this sysctl writable by only privileged users? */ 1455 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) { 1456 int priv; 1457 1458 if (oid->oid_kind & CTLFLAG_PRISON) 1459 priv = PRIV_SYSCTL_WRITEJAIL; 1460 #ifdef VIMAGE 1461 else if ((oid->oid_kind & CTLFLAG_VNET) && 1462 prison_owns_vnet(req->td->td_ucred)) 1463 priv = PRIV_SYSCTL_WRITEJAIL; 1464 #endif 1465 else 1466 priv = PRIV_SYSCTL_WRITE; 1467 error = priv_check(req->td, priv); 1468 if (error) 1469 return (error); 1470 } 1471 1472 if (!oid->oid_handler) 1473 return (EINVAL); 1474 1475 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1476 arg1 = (int *)arg1 + indx; 1477 arg2 -= indx; 1478 } else { 1479 arg1 = oid->oid_arg1; 1480 arg2 = oid->oid_arg2; 1481 } 1482 #ifdef MAC 1483 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2, 1484 req); 1485 if (error != 0) 1486 return (error); 1487 #endif 1488 oid->oid_running++; 1489 SYSCTL_XUNLOCK(); 1490 1491 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 1492 mtx_lock(&Giant); 1493 error = oid->oid_handler(oid, arg1, arg2, req); 1494 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 1495 mtx_unlock(&Giant); 1496 1497 KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error); 1498 1499 SYSCTL_XLOCK(); 1500 oid->oid_running--; 1501 if (oid->oid_running == 0 && (oid->oid_kind & CTLFLAG_DYING) != 0) 1502 wakeup(&oid->oid_running); 1503 return (error); 1504 } 1505 1506 #ifndef _SYS_SYSPROTO_H_ 1507 struct sysctl_args { 1508 int *name; 1509 u_int namelen; 1510 void *old; 1511 size_t *oldlenp; 1512 void *new; 1513 size_t newlen; 1514 }; 1515 #endif 1516 int 1517 sys___sysctl(struct thread *td, struct sysctl_args *uap) 1518 { 1519 int error, i, name[CTL_MAXNAME]; 1520 size_t j; 1521 1522 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 1523 return (EINVAL); 1524 1525 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 1526 if (error) 1527 return (error); 1528 1529 error = userland_sysctl(td, name, uap->namelen, 1530 uap->old, uap->oldlenp, 0, 1531 uap->new, uap->newlen, &j, 0); 1532 if (error && error != ENOMEM) 1533 return (error); 1534 if (uap->oldlenp) { 1535 i = copyout(&j, uap->oldlenp, sizeof(j)); 1536 if (i) 1537 return (i); 1538 } 1539 return (error); 1540 } 1541 1542 /* 1543 * This is used from various compatibility syscalls too. That's why name 1544 * must be in kernel space. 1545 */ 1546 int 1547 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1548 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval, 1549 int flags) 1550 { 1551 int error = 0, memlocked; 1552 struct sysctl_req req; 1553 1554 bzero(&req, sizeof req); 1555 1556 req.td = td; 1557 req.flags = flags; 1558 1559 if (oldlenp) { 1560 if (inkernel) { 1561 req.oldlen = *oldlenp; 1562 } else { 1563 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 1564 if (error) 1565 return (error); 1566 } 1567 } 1568 req.validlen = req.oldlen; 1569 1570 if (old) { 1571 if (!useracc(old, req.oldlen, VM_PROT_WRITE)) 1572 return (EFAULT); 1573 req.oldptr= old; 1574 } 1575 1576 if (new != NULL) { 1577 if (!useracc(new, newlen, VM_PROT_READ)) 1578 return (EFAULT); 1579 req.newlen = newlen; 1580 req.newptr = new; 1581 } 1582 1583 req.oldfunc = sysctl_old_user; 1584 req.newfunc = sysctl_new_user; 1585 req.lock = REQ_UNWIRED; 1586 1587 #ifdef KTRACE 1588 if (KTRPOINT(curthread, KTR_SYSCTL)) 1589 ktrsysctl(name, namelen); 1590 #endif 1591 1592 if (req.oldlen > PAGE_SIZE) { 1593 memlocked = 1; 1594 sx_xlock(&sysctlmemlock); 1595 } else 1596 memlocked = 0; 1597 CURVNET_SET(TD_TO_VNET(td)); 1598 1599 for (;;) { 1600 req.oldidx = 0; 1601 req.newidx = 0; 1602 SYSCTL_XLOCK(); 1603 error = sysctl_root(0, name, namelen, &req); 1604 SYSCTL_XUNLOCK(); 1605 if (error != EAGAIN) 1606 break; 1607 kern_yield(PRI_USER); 1608 } 1609 1610 CURVNET_RESTORE(); 1611 1612 if (req.lock == REQ_WIRED && req.validlen > 0) 1613 vsunlock(req.oldptr, req.validlen); 1614 if (memlocked) 1615 sx_xunlock(&sysctlmemlock); 1616 1617 if (error && error != ENOMEM) 1618 return (error); 1619 1620 if (retval) { 1621 if (req.oldptr && req.oldidx > req.validlen) 1622 *retval = req.validlen; 1623 else 1624 *retval = req.oldidx; 1625 } 1626 return (error); 1627 } 1628 1629 /* 1630 * Drain into a sysctl struct. The user buffer should be wired if a page 1631 * fault would cause issue. 1632 */ 1633 static int 1634 sbuf_sysctl_drain(void *arg, const char *data, int len) 1635 { 1636 struct sysctl_req *req = arg; 1637 int error; 1638 1639 error = SYSCTL_OUT(req, data, len); 1640 KASSERT(error >= 0, ("Got unexpected negative value %d", error)); 1641 return (error == 0 ? len : -error); 1642 } 1643 1644 struct sbuf * 1645 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length, 1646 struct sysctl_req *req) 1647 { 1648 1649 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN); 1650 sbuf_set_drain(s, sbuf_sysctl_drain, req); 1651 return (s); 1652 }
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