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/10.4/sys/kern/kern_sysctl.c 316127 2017-03-29 08:00:11Z ngie $"); 40 41 #include "opt_capsicum.h" 42 #include "opt_compat.h" 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/fail.h> 47 #include <sys/systm.h> 48 #include <sys/capsicum.h> 49 #include <sys/kernel.h> 50 #include <sys/sysctl.h> 51 #include <sys/malloc.h> 52 #include <sys/priv.h> 53 #include <sys/proc.h> 54 #include <sys/jail.h> 55 #include <sys/lock.h> 56 #include <sys/mutex.h> 57 #include <sys/sbuf.h> 58 #include <sys/sx.h> 59 #include <sys/sysproto.h> 60 #include <sys/uio.h> 61 #ifdef KTRACE 62 #include <sys/ktrace.h> 63 #endif 64 65 #include <net/vnet.h> 66 67 #include <security/mac/mac_framework.h> 68 69 #include <vm/vm.h> 70 #include <vm/vm_extern.h> 71 72 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic"); 73 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids"); 74 static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer"); 75 76 /* 77 * The sysctllock protects the MIB tree. It also protects sysctl 78 * contexts used with dynamic sysctls. The sysctl_register_oid() and 79 * sysctl_unregister_oid() routines require the sysctllock to already 80 * be held, so the sysctl_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 int oid_number; 146 int timeout = 2; 147 148 /* 149 * First check if another oid with the same name already 150 * exists in the parent's list. 151 */ 152 SYSCTL_ASSERT_XLOCKED(); 153 p = sysctl_find_oidname(oidp->oid_name, parent); 154 if (p != NULL) { 155 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 156 p->oid_refcnt++; 157 return; 158 } else { 159 printf("can't re-use a leaf (%s)!\n", p->oid_name); 160 return; 161 } 162 } 163 /* get current OID number */ 164 oid_number = oidp->oid_number; 165 166 #if (OID_AUTO >= 0) 167 #error "OID_AUTO is expected to be a negative value" 168 #endif 169 /* 170 * Any negative OID number qualifies as OID_AUTO. Valid OID 171 * numbers should always be positive. 172 * 173 * NOTE: DO NOT change the starting value here, change it in 174 * <sys/sysctl.h>, and make sure it is at least 256 to 175 * accommodate e.g. net.inet.raw as a static sysctl node. 176 */ 177 if (oid_number < 0) { 178 static int newoid; 179 180 /* 181 * By decrementing the next OID number we spend less 182 * time inserting the OIDs into a sorted list. 183 */ 184 if (--newoid < CTL_AUTO_START) 185 newoid = 0x7fffffff; 186 187 oid_number = newoid; 188 } 189 190 /* 191 * Insert the OID into the parent's list sorted by OID number. 192 */ 193 retry: 194 q = NULL; 195 SLIST_FOREACH(p, parent, oid_link) { 196 /* check if the current OID number is in use */ 197 if (oid_number == p->oid_number) { 198 /* get the next valid OID number */ 199 if (oid_number < CTL_AUTO_START || 200 oid_number == 0x7fffffff) { 201 /* wraparound - restart */ 202 oid_number = CTL_AUTO_START; 203 /* don't loop forever */ 204 if (!timeout--) 205 panic("sysctl: Out of OID numbers\n"); 206 goto retry; 207 } else { 208 oid_number++; 209 } 210 } else if (oid_number < p->oid_number) 211 break; 212 q = p; 213 } 214 /* check for non-auto OID number collision */ 215 if (oidp->oid_number >= 0 && oidp->oid_number < CTL_AUTO_START && 216 oid_number >= CTL_AUTO_START) { 217 printf("sysctl: OID number(%d) is already in use for '%s'\n", 218 oidp->oid_number, oidp->oid_name); 219 } 220 /* update the OID number, if any */ 221 oidp->oid_number = oid_number; 222 if (q != NULL) 223 SLIST_INSERT_AFTER(q, oidp, oid_link); 224 else 225 SLIST_INSERT_HEAD(parent, oidp, oid_link); 226 } 227 228 void 229 sysctl_unregister_oid(struct sysctl_oid *oidp) 230 { 231 struct sysctl_oid *p; 232 int error; 233 234 SYSCTL_ASSERT_XLOCKED(); 235 error = ENOENT; 236 if (oidp->oid_number == OID_AUTO) { 237 error = EINVAL; 238 } else { 239 SLIST_FOREACH(p, oidp->oid_parent, oid_link) { 240 if (p == oidp) { 241 SLIST_REMOVE(oidp->oid_parent, oidp, 242 sysctl_oid, oid_link); 243 error = 0; 244 break; 245 } 246 } 247 } 248 249 /* 250 * This can happen when a module fails to register and is 251 * being unloaded afterwards. It should not be a panic() 252 * for normal use. 253 */ 254 if (error) 255 printf("%s: failed to unregister sysctl\n", __func__); 256 } 257 258 /* Initialize a new context to keep track of dynamically added sysctls. */ 259 int 260 sysctl_ctx_init(struct sysctl_ctx_list *c) 261 { 262 263 if (c == NULL) { 264 return (EINVAL); 265 } 266 267 /* 268 * No locking here, the caller is responsible for not adding 269 * new nodes to a context until after this function has 270 * returned. 271 */ 272 TAILQ_INIT(c); 273 return (0); 274 } 275 276 /* Free the context, and destroy all dynamic oids registered in this context */ 277 int 278 sysctl_ctx_free(struct sysctl_ctx_list *clist) 279 { 280 struct sysctl_ctx_entry *e, *e1; 281 int error; 282 283 error = 0; 284 /* 285 * First perform a "dry run" to check if it's ok to remove oids. 286 * XXX FIXME 287 * XXX This algorithm is a hack. But I don't know any 288 * XXX better solution for now... 289 */ 290 SYSCTL_XLOCK(); 291 TAILQ_FOREACH(e, clist, link) { 292 error = sysctl_remove_oid_locked(e->entry, 0, 0); 293 if (error) 294 break; 295 } 296 /* 297 * Restore deregistered entries, either from the end, 298 * or from the place where error occurred. 299 * e contains the entry that was not unregistered 300 */ 301 if (error) 302 e1 = TAILQ_PREV(e, sysctl_ctx_list, link); 303 else 304 e1 = TAILQ_LAST(clist, sysctl_ctx_list); 305 while (e1 != NULL) { 306 sysctl_register_oid(e1->entry); 307 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link); 308 } 309 if (error) { 310 SYSCTL_XUNLOCK(); 311 return(EBUSY); 312 } 313 /* Now really delete the entries */ 314 e = TAILQ_FIRST(clist); 315 while (e != NULL) { 316 e1 = TAILQ_NEXT(e, link); 317 error = sysctl_remove_oid_locked(e->entry, 1, 0); 318 if (error) 319 panic("sysctl_remove_oid: corrupt tree, entry: %s", 320 e->entry->oid_name); 321 free(e, M_SYSCTLOID); 322 e = e1; 323 } 324 SYSCTL_XUNLOCK(); 325 return (error); 326 } 327 328 /* Add an entry to the context */ 329 struct sysctl_ctx_entry * 330 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 331 { 332 struct sysctl_ctx_entry *e; 333 334 SYSCTL_ASSERT_XLOCKED(); 335 if (clist == NULL || oidp == NULL) 336 return(NULL); 337 e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK); 338 e->entry = oidp; 339 TAILQ_INSERT_HEAD(clist, e, link); 340 return (e); 341 } 342 343 /* Find an entry in the context */ 344 struct sysctl_ctx_entry * 345 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 346 { 347 struct sysctl_ctx_entry *e; 348 349 SYSCTL_ASSERT_XLOCKED(); 350 if (clist == NULL || oidp == NULL) 351 return(NULL); 352 TAILQ_FOREACH(e, clist, link) { 353 if(e->entry == oidp) 354 return(e); 355 } 356 return (e); 357 } 358 359 /* 360 * Delete an entry from the context. 361 * NOTE: this function doesn't free oidp! You have to remove it 362 * with sysctl_remove_oid(). 363 */ 364 int 365 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) 366 { 367 struct sysctl_ctx_entry *e; 368 369 if (clist == NULL || oidp == NULL) 370 return (EINVAL); 371 SYSCTL_XLOCK(); 372 e = sysctl_ctx_entry_find(clist, oidp); 373 if (e != NULL) { 374 TAILQ_REMOVE(clist, e, link); 375 SYSCTL_XUNLOCK(); 376 free(e, M_SYSCTLOID); 377 return (0); 378 } else { 379 SYSCTL_XUNLOCK(); 380 return (ENOENT); 381 } 382 } 383 384 /* 385 * Remove dynamically created sysctl trees. 386 * oidp - top of the tree to be removed 387 * del - if 0 - just deregister, otherwise free up entries as well 388 * recurse - if != 0 traverse the subtree to be deleted 389 */ 390 int 391 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse) 392 { 393 int error; 394 395 SYSCTL_XLOCK(); 396 error = sysctl_remove_oid_locked(oidp, del, recurse); 397 SYSCTL_XUNLOCK(); 398 return (error); 399 } 400 401 int 402 sysctl_remove_name(struct sysctl_oid *parent, const char *name, 403 int del, int recurse) 404 { 405 struct sysctl_oid *p, *tmp; 406 int error; 407 408 error = ENOENT; 409 SYSCTL_XLOCK(); 410 SLIST_FOREACH_SAFE(p, SYSCTL_CHILDREN(parent), oid_link, tmp) { 411 if (strcmp(p->oid_name, name) == 0) { 412 error = sysctl_remove_oid_locked(p, del, recurse); 413 break; 414 } 415 } 416 SYSCTL_XUNLOCK(); 417 418 return (error); 419 } 420 421 422 static int 423 sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse) 424 { 425 struct sysctl_oid *p, *tmp; 426 int error; 427 428 SYSCTL_ASSERT_XLOCKED(); 429 if (oidp == NULL) 430 return(EINVAL); 431 if ((oidp->oid_kind & CTLFLAG_DYN) == 0) { 432 printf("Warning: can't remove non-dynamic nodes (%s)!\n", 433 oidp->oid_name); 434 return (EINVAL); 435 } 436 /* 437 * WARNING: normal method to do this should be through 438 * sysctl_ctx_free(). Use recursing as the last resort 439 * method to purge your sysctl tree of leftovers... 440 * However, if some other code still references these nodes, 441 * it will panic. 442 */ 443 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 444 if (oidp->oid_refcnt == 1) { 445 SLIST_FOREACH_SAFE(p, 446 SYSCTL_CHILDREN(oidp), oid_link, tmp) { 447 if (!recurse) { 448 printf("Warning: failed attempt to " 449 "remove oid %s with child %s\n", 450 oidp->oid_name, p->oid_name); 451 return (ENOTEMPTY); 452 } 453 error = sysctl_remove_oid_locked(p, del, 454 recurse); 455 if (error) 456 return (error); 457 } 458 if (del) 459 free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID); 460 } 461 } 462 if (oidp->oid_refcnt > 1 ) { 463 oidp->oid_refcnt--; 464 } else { 465 if (oidp->oid_refcnt == 0) { 466 printf("Warning: bad oid_refcnt=%u (%s)!\n", 467 oidp->oid_refcnt, oidp->oid_name); 468 return (EINVAL); 469 } 470 sysctl_unregister_oid(oidp); 471 if (del) { 472 /* 473 * Wait for all threads running the handler to drain. 474 * This preserves the previous behavior when the 475 * sysctl lock was held across a handler invocation, 476 * and is necessary for module unload correctness. 477 */ 478 while (oidp->oid_running > 0) { 479 oidp->oid_kind |= CTLFLAG_DYING; 480 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0); 481 } 482 if (oidp->oid_descr) 483 free(__DECONST(char *, oidp->oid_descr), 484 M_SYSCTLOID); 485 free(__DECONST(char *, oidp->oid_name), M_SYSCTLOID); 486 free(oidp, M_SYSCTLOID); 487 } 488 } 489 return (0); 490 } 491 /* 492 * Create new sysctls at run time. 493 * clist may point to a valid context initialized with sysctl_ctx_init(). 494 */ 495 struct sysctl_oid * 496 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, 497 int number, const char *name, int kind, void *arg1, intptr_t arg2, 498 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr) 499 { 500 struct sysctl_oid *oidp; 501 502 /* You have to hook up somewhere.. */ 503 if (parent == NULL) 504 return(NULL); 505 /* Check if the node already exists, otherwise create it */ 506 SYSCTL_XLOCK(); 507 oidp = sysctl_find_oidname(name, parent); 508 if (oidp != NULL) { 509 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 510 oidp->oid_refcnt++; 511 /* Update the context */ 512 if (clist != NULL) 513 sysctl_ctx_entry_add(clist, oidp); 514 SYSCTL_XUNLOCK(); 515 return (oidp); 516 } else { 517 SYSCTL_XUNLOCK(); 518 printf("can't re-use a leaf (%s)!\n", name); 519 return (NULL); 520 } 521 } 522 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO); 523 oidp->oid_parent = parent; 524 SLIST_NEXT(oidp, oid_link) = NULL; 525 oidp->oid_number = number; 526 oidp->oid_refcnt = 1; 527 oidp->oid_name = strdup(name, M_SYSCTLOID); 528 oidp->oid_handler = handler; 529 oidp->oid_kind = CTLFLAG_DYN | kind; 530 if ((kind & CTLTYPE) == CTLTYPE_NODE) { 531 /* Allocate space for children */ 532 SYSCTL_CHILDREN_SET(oidp, malloc(sizeof(struct sysctl_oid_list), 533 M_SYSCTLOID, M_WAITOK)); 534 SLIST_INIT(SYSCTL_CHILDREN(oidp)); 535 oidp->oid_arg2 = arg2; 536 } else { 537 oidp->oid_arg1 = arg1; 538 oidp->oid_arg2 = arg2; 539 } 540 oidp->oid_fmt = fmt; 541 if (descr) 542 oidp->oid_descr = strdup(descr, M_SYSCTLOID); 543 /* Update the context, if used */ 544 if (clist != NULL) 545 sysctl_ctx_entry_add(clist, oidp); 546 /* Register this oid */ 547 sysctl_register_oid(oidp); 548 SYSCTL_XUNLOCK(); 549 return (oidp); 550 } 551 552 /* 553 * Rename an existing oid. 554 */ 555 void 556 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) 557 { 558 char *newname; 559 char *oldname; 560 561 newname = strdup(name, M_SYSCTLOID); 562 SYSCTL_XLOCK(); 563 oldname = __DECONST(char *, oidp->oid_name); 564 oidp->oid_name = newname; 565 SYSCTL_XUNLOCK(); 566 free(oldname, M_SYSCTLOID); 567 } 568 569 /* 570 * Reparent an existing oid. 571 */ 572 int 573 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent) 574 { 575 struct sysctl_oid *oidp; 576 577 SYSCTL_XLOCK(); 578 if (oid->oid_parent == parent) { 579 SYSCTL_XUNLOCK(); 580 return (0); 581 } 582 oidp = sysctl_find_oidname(oid->oid_name, parent); 583 if (oidp != NULL) { 584 SYSCTL_XUNLOCK(); 585 return (EEXIST); 586 } 587 sysctl_unregister_oid(oid); 588 oid->oid_parent = parent; 589 oid->oid_number = OID_AUTO; 590 sysctl_register_oid(oid); 591 SYSCTL_XUNLOCK(); 592 return (0); 593 } 594 595 /* 596 * Register the kernel's oids on startup. 597 */ 598 SET_DECLARE(sysctl_set, struct sysctl_oid); 599 600 static void 601 sysctl_register_all(void *arg) 602 { 603 struct sysctl_oid **oidp; 604 605 sx_init(&sysctlmemlock, "sysctl mem"); 606 SYSCTL_INIT(); 607 SYSCTL_XLOCK(); 608 SET_FOREACH(oidp, sysctl_set) 609 sysctl_register_oid(*oidp); 610 SYSCTL_XUNLOCK(); 611 } 612 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0); 613 614 /* 615 * "Staff-functions" 616 * 617 * These functions implement a presently undocumented interface 618 * used by the sysctl program to walk the tree, and get the type 619 * so it can print the value. 620 * This interface is under work and consideration, and should probably 621 * be killed with a big axe by the first person who can find the time. 622 * (be aware though, that the proper interface isn't as obvious as it 623 * may seem, there are various conflicting requirements. 624 * 625 * {0,0} printf the entire MIB-tree. 626 * {0,1,...} return the name of the "..." OID. 627 * {0,2,...} return the next OID. 628 * {0,3} return the OID of the name in "new" 629 * {0,4,...} return the kind & format info for the "..." OID. 630 * {0,5,...} return the description the "..." OID. 631 */ 632 633 #ifdef SYSCTL_DEBUG 634 static void 635 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 636 { 637 int k; 638 struct sysctl_oid *oidp; 639 640 SYSCTL_ASSERT_XLOCKED(); 641 SLIST_FOREACH(oidp, l, oid_link) { 642 643 for (k=0; k<i; k++) 644 printf(" "); 645 646 printf("%d %s ", oidp->oid_number, oidp->oid_name); 647 648 printf("%c%c", 649 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 650 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 651 652 if (oidp->oid_handler) 653 printf(" *Handler"); 654 655 switch (oidp->oid_kind & CTLTYPE) { 656 case CTLTYPE_NODE: 657 printf(" Node\n"); 658 if (!oidp->oid_handler) { 659 sysctl_sysctl_debug_dump_node( 660 oidp->oid_arg1, i+2); 661 } 662 break; 663 case CTLTYPE_INT: printf(" Int\n"); break; 664 case CTLTYPE_UINT: printf(" u_int\n"); break; 665 case CTLTYPE_LONG: printf(" Long\n"); break; 666 case CTLTYPE_ULONG: printf(" u_long\n"); break; 667 case CTLTYPE_STRING: printf(" String\n"); break; 668 case CTLTYPE_U64: printf(" uint64_t\n"); break; 669 case CTLTYPE_S64: printf(" int64_t\n"); break; 670 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break; 671 default: printf("\n"); 672 } 673 674 } 675 } 676 677 static int 678 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 679 { 680 int error; 681 682 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 683 if (error) 684 return (error); 685 SYSCTL_XLOCK(); 686 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 687 SYSCTL_XUNLOCK(); 688 return (ENOENT); 689 } 690 691 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD, 692 0, 0, sysctl_sysctl_debug, "-", ""); 693 #endif 694 695 static int 696 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 697 { 698 int *name = (int *) arg1; 699 u_int namelen = arg2; 700 int error = 0; 701 struct sysctl_oid *oid; 702 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 703 char buf[10]; 704 705 SYSCTL_XLOCK(); 706 while (namelen) { 707 if (!lsp) { 708 snprintf(buf,sizeof(buf),"%d",*name); 709 if (req->oldidx) 710 error = SYSCTL_OUT(req, ".", 1); 711 if (!error) 712 error = SYSCTL_OUT(req, buf, strlen(buf)); 713 if (error) 714 goto out; 715 namelen--; 716 name++; 717 continue; 718 } 719 lsp2 = 0; 720 SLIST_FOREACH(oid, lsp, oid_link) { 721 if (oid->oid_number != *name) 722 continue; 723 724 if (req->oldidx) 725 error = SYSCTL_OUT(req, ".", 1); 726 if (!error) 727 error = SYSCTL_OUT(req, oid->oid_name, 728 strlen(oid->oid_name)); 729 if (error) 730 goto out; 731 732 namelen--; 733 name++; 734 735 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 736 break; 737 738 if (oid->oid_handler) 739 break; 740 741 lsp2 = SYSCTL_CHILDREN(oid); 742 break; 743 } 744 lsp = lsp2; 745 } 746 error = SYSCTL_OUT(req, "", 1); 747 out: 748 SYSCTL_XUNLOCK(); 749 return (error); 750 } 751 752 /* 753 * XXXRW/JA: Shouldn't return name data for nodes that we don't permit in 754 * capability mode. 755 */ 756 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_CAPRD, 757 sysctl_sysctl_name, ""); 758 759 static int 760 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 761 int *next, int *len, int level, struct sysctl_oid **oidpp) 762 { 763 struct sysctl_oid *oidp; 764 765 SYSCTL_ASSERT_XLOCKED(); 766 *len = level; 767 SLIST_FOREACH(oidp, lsp, oid_link) { 768 *next = oidp->oid_number; 769 *oidpp = oidp; 770 771 if (oidp->oid_kind & CTLFLAG_SKIP) 772 continue; 773 774 if (!namelen) { 775 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 776 return (0); 777 if (oidp->oid_handler) 778 /* We really should call the handler here...*/ 779 return (0); 780 lsp = SYSCTL_CHILDREN(oidp); 781 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 782 len, level+1, oidpp)) 783 return (0); 784 goto emptynode; 785 } 786 787 if (oidp->oid_number < *name) 788 continue; 789 790 if (oidp->oid_number > *name) { 791 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 792 return (0); 793 if (oidp->oid_handler) 794 return (0); 795 lsp = SYSCTL_CHILDREN(oidp); 796 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 797 next+1, len, level+1, oidpp)) 798 return (0); 799 goto next; 800 } 801 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 802 continue; 803 804 if (oidp->oid_handler) 805 continue; 806 807 lsp = SYSCTL_CHILDREN(oidp); 808 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 809 len, level+1, oidpp)) 810 return (0); 811 next: 812 namelen = 1; 813 emptynode: 814 *len = level; 815 } 816 return (1); 817 } 818 819 static int 820 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 821 { 822 int *name = (int *) arg1; 823 u_int namelen = arg2; 824 int i, j, error; 825 struct sysctl_oid *oid; 826 struct sysctl_oid_list *lsp = &sysctl__children; 827 int newoid[CTL_MAXNAME]; 828 829 SYSCTL_XLOCK(); 830 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 831 SYSCTL_XUNLOCK(); 832 if (i) 833 return (ENOENT); 834 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 835 return (error); 836 } 837 838 /* 839 * XXXRW/JA: Shouldn't return next data for nodes that we don't permit in 840 * capability mode. 841 */ 842 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_CAPRD, 843 sysctl_sysctl_next, ""); 844 845 static int 846 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) 847 { 848 struct sysctl_oid *oidp; 849 struct sysctl_oid_list *lsp = &sysctl__children; 850 char *p; 851 852 SYSCTL_ASSERT_XLOCKED(); 853 854 for (*len = 0; *len < CTL_MAXNAME;) { 855 p = strsep(&name, "."); 856 857 oidp = SLIST_FIRST(lsp); 858 for (;; oidp = SLIST_NEXT(oidp, oid_link)) { 859 if (oidp == NULL) 860 return (ENOENT); 861 if (strcmp(p, oidp->oid_name) == 0) 862 break; 863 } 864 *oid++ = oidp->oid_number; 865 (*len)++; 866 867 if (name == NULL || *name == '\0') { 868 if (oidpp) 869 *oidpp = oidp; 870 return (0); 871 } 872 873 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 874 break; 875 876 if (oidp->oid_handler) 877 break; 878 879 lsp = SYSCTL_CHILDREN(oidp); 880 } 881 return (ENOENT); 882 } 883 884 static int 885 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 886 { 887 char *p; 888 int error, oid[CTL_MAXNAME], len = 0; 889 struct sysctl_oid *op = 0; 890 891 if (!req->newlen) 892 return (ENOENT); 893 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 894 return (ENAMETOOLONG); 895 896 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK); 897 898 error = SYSCTL_IN(req, p, req->newlen); 899 if (error) { 900 free(p, M_SYSCTL); 901 return (error); 902 } 903 904 p [req->newlen] = '\0'; 905 906 SYSCTL_XLOCK(); 907 error = name2oid(p, oid, &len, &op); 908 SYSCTL_XUNLOCK(); 909 910 free(p, M_SYSCTL); 911 912 if (error) 913 return (error); 914 915 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 916 return (error); 917 } 918 919 /* 920 * XXXRW/JA: Shouldn't return name2oid data for nodes that we don't permit in 921 * capability mode. 922 */ 923 SYSCTL_PROC(_sysctl, 3, name2oid, 924 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE 925 | CTLFLAG_CAPRW, 0, 0, sysctl_sysctl_name2oid, "I", ""); 926 927 static int 928 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 929 { 930 struct sysctl_oid *oid; 931 int error; 932 933 SYSCTL_XLOCK(); 934 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 935 if (error) 936 goto out; 937 938 if (oid->oid_fmt == NULL) { 939 error = ENOENT; 940 goto out; 941 } 942 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 943 if (error) 944 goto out; 945 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 946 out: 947 SYSCTL_XUNLOCK(); 948 return (error); 949 } 950 951 952 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD, 953 sysctl_sysctl_oidfmt, ""); 954 955 static int 956 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 957 { 958 struct sysctl_oid *oid; 959 int error; 960 961 SYSCTL_XLOCK(); 962 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 963 if (error) 964 goto out; 965 966 if (oid->oid_descr == NULL) { 967 error = ENOENT; 968 goto out; 969 } 970 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 971 out: 972 SYSCTL_XUNLOCK(); 973 return (error); 974 } 975 976 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_CAPRD, 977 sysctl_sysctl_oiddescr, ""); 978 979 /* 980 * Default "handler" functions. 981 */ 982 983 /* 984 * Handle an int, signed or unsigned. 985 * Two cases: 986 * a variable: point arg1 at it. 987 * a constant: pass it in arg2. 988 */ 989 990 int 991 sysctl_handle_int(SYSCTL_HANDLER_ARGS) 992 { 993 int tmpout, error = 0; 994 995 /* 996 * Attempt to get a coherent snapshot by making a copy of the data. 997 */ 998 if (arg1) 999 tmpout = *(int *)arg1; 1000 else 1001 tmpout = arg2; 1002 error = SYSCTL_OUT(req, &tmpout, sizeof(int)); 1003 1004 if (error || !req->newptr) 1005 return (error); 1006 1007 if (!arg1) 1008 error = EPERM; 1009 else 1010 error = SYSCTL_IN(req, arg1, sizeof(int)); 1011 return (error); 1012 } 1013 1014 /* 1015 * Based on on sysctl_handle_int() convert milliseconds into ticks. 1016 * Note: this is used by TCP. 1017 */ 1018 1019 int 1020 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) 1021 { 1022 int error, s, tt; 1023 1024 tt = *(int *)arg1; 1025 s = (int)((int64_t)tt * 1000 / hz); 1026 1027 error = sysctl_handle_int(oidp, &s, 0, req); 1028 if (error || !req->newptr) 1029 return (error); 1030 1031 tt = (int)((int64_t)s * hz / 1000); 1032 if (tt < 1) 1033 return (EINVAL); 1034 1035 *(int *)arg1 = tt; 1036 return (0); 1037 } 1038 1039 1040 /* 1041 * Handle a long, signed or unsigned. 1042 * Two cases: 1043 * a variable: point arg1 at it. 1044 * a constant: pass it in arg2. 1045 */ 1046 1047 int 1048 sysctl_handle_long(SYSCTL_HANDLER_ARGS) 1049 { 1050 int error = 0; 1051 long tmplong; 1052 #ifdef SCTL_MASK32 1053 int tmpint; 1054 #endif 1055 1056 /* 1057 * Attempt to get a coherent snapshot by making a copy of the data. 1058 */ 1059 if (arg1) 1060 tmplong = *(long *)arg1; 1061 else 1062 tmplong = arg2; 1063 #ifdef SCTL_MASK32 1064 if (req->flags & SCTL_MASK32) { 1065 tmpint = tmplong; 1066 error = SYSCTL_OUT(req, &tmpint, sizeof(int)); 1067 } else 1068 #endif 1069 error = SYSCTL_OUT(req, &tmplong, sizeof(long)); 1070 1071 if (error || !req->newptr) 1072 return (error); 1073 1074 if (!arg1) 1075 error = EPERM; 1076 #ifdef SCTL_MASK32 1077 else if (req->flags & SCTL_MASK32) { 1078 error = SYSCTL_IN(req, &tmpint, sizeof(int)); 1079 *(long *)arg1 = (long)tmpint; 1080 } 1081 #endif 1082 else 1083 error = SYSCTL_IN(req, arg1, sizeof(long)); 1084 return (error); 1085 } 1086 1087 /* 1088 * Handle a 64 bit int, signed or unsigned. 1089 * Two cases: 1090 * a variable: point arg1 at it. 1091 * a constant: pass it in arg2. 1092 */ 1093 int 1094 sysctl_handle_64(SYSCTL_HANDLER_ARGS) 1095 { 1096 int error = 0; 1097 uint64_t tmpout; 1098 1099 /* 1100 * Attempt to get a coherent snapshot by making a copy of the data. 1101 */ 1102 if (arg1) 1103 tmpout = *(uint64_t *)arg1; 1104 else 1105 tmpout = arg2; 1106 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t)); 1107 1108 if (error || !req->newptr) 1109 return (error); 1110 1111 if (!arg1) 1112 error = EPERM; 1113 else 1114 error = SYSCTL_IN(req, arg1, sizeof(uint64_t)); 1115 return (error); 1116 } 1117 1118 /* 1119 * Handle our generic '\0' terminated 'C' string. 1120 * Two cases: 1121 * a variable string: point arg1 at it, arg2 is max length. 1122 * a constant string: point arg1 at it, arg2 is zero. 1123 */ 1124 1125 int 1126 sysctl_handle_string(SYSCTL_HANDLER_ARGS) 1127 { 1128 int error=0; 1129 char *tmparg; 1130 size_t outlen; 1131 1132 /* 1133 * Attempt to get a coherent snapshot by copying to a 1134 * temporary kernel buffer. 1135 */ 1136 retry: 1137 outlen = strlen((char *)arg1)+1; 1138 tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK); 1139 1140 if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) { 1141 free(tmparg, M_SYSCTLTMP); 1142 goto retry; 1143 } 1144 1145 error = SYSCTL_OUT(req, tmparg, outlen); 1146 free(tmparg, M_SYSCTLTMP); 1147 1148 if (error || !req->newptr) 1149 return (error); 1150 1151 if ((req->newlen - req->newidx) >= arg2) { 1152 error = EINVAL; 1153 } else { 1154 arg2 = (req->newlen - req->newidx); 1155 error = SYSCTL_IN(req, arg1, arg2); 1156 ((char *)arg1)[arg2] = '\0'; 1157 } 1158 1159 return (error); 1160 } 1161 1162 /* 1163 * Handle any kind of opaque data. 1164 * arg1 points to it, arg2 is the size. 1165 */ 1166 1167 int 1168 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 1169 { 1170 int error, tries; 1171 u_int generation; 1172 struct sysctl_req req2; 1173 1174 /* 1175 * Attempt to get a coherent snapshot, by using the thread 1176 * pre-emption counter updated from within mi_switch() to 1177 * determine if we were pre-empted during a bcopy() or 1178 * copyout(). Make 3 attempts at doing this before giving up. 1179 * If we encounter an error, stop immediately. 1180 */ 1181 tries = 0; 1182 req2 = *req; 1183 retry: 1184 generation = curthread->td_generation; 1185 error = SYSCTL_OUT(req, arg1, arg2); 1186 if (error) 1187 return (error); 1188 tries++; 1189 if (generation != curthread->td_generation && tries < 3) { 1190 *req = req2; 1191 goto retry; 1192 } 1193 1194 error = SYSCTL_IN(req, arg1, arg2); 1195 1196 return (error); 1197 } 1198 1199 /* 1200 * Transfer functions to/from kernel space. 1201 * XXX: rather untested at this point 1202 */ 1203 static int 1204 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 1205 { 1206 size_t i = 0; 1207 1208 if (req->oldptr) { 1209 i = l; 1210 if (req->oldlen <= req->oldidx) 1211 i = 0; 1212 else 1213 if (i > req->oldlen - req->oldidx) 1214 i = req->oldlen - req->oldidx; 1215 if (i > 0) 1216 bcopy(p, (char *)req->oldptr + req->oldidx, i); 1217 } 1218 req->oldidx += l; 1219 if (req->oldptr && i != l) 1220 return (ENOMEM); 1221 return (0); 1222 } 1223 1224 static int 1225 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 1226 { 1227 if (!req->newptr) 1228 return (0); 1229 if (req->newlen - req->newidx < l) 1230 return (EINVAL); 1231 bcopy((char *)req->newptr + req->newidx, p, l); 1232 req->newidx += l; 1233 return (0); 1234 } 1235 1236 int 1237 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1238 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags) 1239 { 1240 int error = 0; 1241 struct sysctl_req req; 1242 1243 bzero(&req, sizeof req); 1244 1245 req.td = td; 1246 req.flags = flags; 1247 1248 if (oldlenp) { 1249 req.oldlen = *oldlenp; 1250 } 1251 req.validlen = req.oldlen; 1252 1253 if (old) { 1254 req.oldptr= old; 1255 } 1256 1257 if (new != NULL) { 1258 req.newlen = newlen; 1259 req.newptr = new; 1260 } 1261 1262 req.oldfunc = sysctl_old_kernel; 1263 req.newfunc = sysctl_new_kernel; 1264 req.lock = REQ_UNWIRED; 1265 1266 SYSCTL_XLOCK(); 1267 error = sysctl_root(0, name, namelen, &req); 1268 SYSCTL_XUNLOCK(); 1269 1270 if (req.lock == REQ_WIRED && req.validlen > 0) 1271 vsunlock(req.oldptr, req.validlen); 1272 1273 if (error && error != ENOMEM) 1274 return (error); 1275 1276 if (retval) { 1277 if (req.oldptr && req.oldidx > req.validlen) 1278 *retval = req.validlen; 1279 else 1280 *retval = req.oldidx; 1281 } 1282 return (error); 1283 } 1284 1285 int 1286 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp, 1287 void *new, size_t newlen, size_t *retval, int flags) 1288 { 1289 int oid[CTL_MAXNAME]; 1290 size_t oidlen, plen; 1291 int error; 1292 1293 oid[0] = 0; /* sysctl internal magic */ 1294 oid[1] = 3; /* name2oid */ 1295 oidlen = sizeof(oid); 1296 1297 error = kernel_sysctl(td, oid, 2, oid, &oidlen, 1298 (void *)name, strlen(name), &plen, flags); 1299 if (error) 1300 return (error); 1301 1302 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp, 1303 new, newlen, retval, flags); 1304 return (error); 1305 } 1306 1307 /* 1308 * Transfer function to/from user space. 1309 */ 1310 static int 1311 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1312 { 1313 size_t i, len, origidx; 1314 int error; 1315 1316 origidx = req->oldidx; 1317 req->oldidx += l; 1318 if (req->oldptr == NULL) 1319 return (0); 1320 /* 1321 * If we have not wired the user supplied buffer and we are currently 1322 * holding locks, drop a witness warning, as it's possible that 1323 * write operations to the user page can sleep. 1324 */ 1325 if (req->lock != REQ_WIRED) 1326 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1327 "sysctl_old_user()"); 1328 i = l; 1329 len = req->validlen; 1330 if (len <= origidx) 1331 i = 0; 1332 else { 1333 if (i > len - origidx) 1334 i = len - origidx; 1335 if (req->lock == REQ_WIRED) { 1336 error = copyout_nofault(p, (char *)req->oldptr + 1337 origidx, i); 1338 } else 1339 error = copyout(p, (char *)req->oldptr + origidx, i); 1340 if (error != 0) 1341 return (error); 1342 } 1343 if (i < l) 1344 return (ENOMEM); 1345 return (0); 1346 } 1347 1348 static int 1349 sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1350 { 1351 int error; 1352 1353 if (!req->newptr) 1354 return (0); 1355 if (req->newlen - req->newidx < l) 1356 return (EINVAL); 1357 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1358 "sysctl_new_user()"); 1359 error = copyin((char *)req->newptr + req->newidx, p, l); 1360 req->newidx += l; 1361 return (error); 1362 } 1363 1364 /* 1365 * Wire the user space destination buffer. If set to a value greater than 1366 * zero, the len parameter limits the maximum amount of wired memory. 1367 */ 1368 int 1369 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len) 1370 { 1371 int ret; 1372 size_t wiredlen; 1373 1374 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen; 1375 ret = 0; 1376 if (req->lock != REQ_WIRED && req->oldptr && 1377 req->oldfunc == sysctl_old_user) { 1378 if (wiredlen != 0) { 1379 ret = vslock(req->oldptr, wiredlen); 1380 if (ret != 0) { 1381 if (ret != ENOMEM) 1382 return (ret); 1383 wiredlen = 0; 1384 } 1385 } 1386 req->lock = REQ_WIRED; 1387 req->validlen = wiredlen; 1388 } 1389 return (0); 1390 } 1391 1392 int 1393 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1394 int *nindx, struct sysctl_req *req) 1395 { 1396 struct sysctl_oid_list *lsp; 1397 struct sysctl_oid *oid; 1398 int indx; 1399 1400 SYSCTL_ASSERT_XLOCKED(); 1401 lsp = &sysctl__children; 1402 indx = 0; 1403 while (indx < CTL_MAXNAME) { 1404 SLIST_FOREACH(oid, lsp, oid_link) { 1405 if (oid->oid_number == name[indx]) 1406 break; 1407 } 1408 if (oid == NULL) 1409 return (ENOENT); 1410 1411 indx++; 1412 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1413 if (oid->oid_handler != NULL || indx == namelen) { 1414 *noid = oid; 1415 if (nindx != NULL) 1416 *nindx = indx; 1417 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1418 ("%s found DYING node %p", __func__, oid)); 1419 return (0); 1420 } 1421 lsp = SYSCTL_CHILDREN(oid); 1422 } else if (indx == namelen) { 1423 *noid = oid; 1424 if (nindx != NULL) 1425 *nindx = indx; 1426 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1427 ("%s found DYING node %p", __func__, oid)); 1428 return (0); 1429 } else { 1430 return (ENOTDIR); 1431 } 1432 } 1433 return (ENOENT); 1434 } 1435 1436 /* 1437 * Traverse our tree, and find the right node, execute whatever it points 1438 * to, and return the resulting error code. 1439 */ 1440 1441 static int 1442 sysctl_root(SYSCTL_HANDLER_ARGS) 1443 { 1444 struct sysctl_oid *oid; 1445 int error, indx, lvl; 1446 1447 SYSCTL_ASSERT_XLOCKED(); 1448 1449 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1450 if (error) 1451 return (error); 1452 1453 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1454 /* 1455 * You can't call a sysctl when it's a node, but has 1456 * no handler. Inform the user that it's a node. 1457 * The indx may or may not be the same as namelen. 1458 */ 1459 if (oid->oid_handler == NULL) 1460 return (EISDIR); 1461 } 1462 1463 /* Is this sysctl writable? */ 1464 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) 1465 return (EPERM); 1466 1467 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL")); 1468 1469 #ifdef CAPABILITY_MODE 1470 /* 1471 * If the process is in capability mode, then don't permit reading or 1472 * writing unless specifically granted for the node. 1473 */ 1474 if (IN_CAPABILITY_MODE(req->td)) { 1475 if (req->oldptr && !(oid->oid_kind & CTLFLAG_CAPRD)) 1476 return (EPERM); 1477 if (req->newptr && !(oid->oid_kind & CTLFLAG_CAPWR)) 1478 return (EPERM); 1479 } 1480 #endif 1481 1482 /* Is this sysctl sensitive to securelevels? */ 1483 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) { 1484 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE; 1485 error = securelevel_gt(req->td->td_ucred, lvl); 1486 if (error) 1487 return (error); 1488 } 1489 1490 /* Is this sysctl writable by only privileged users? */ 1491 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) { 1492 int priv; 1493 1494 if (oid->oid_kind & CTLFLAG_PRISON) 1495 priv = PRIV_SYSCTL_WRITEJAIL; 1496 #ifdef VIMAGE 1497 else if ((oid->oid_kind & CTLFLAG_VNET) && 1498 prison_owns_vnet(req->td->td_ucred)) 1499 priv = PRIV_SYSCTL_WRITEJAIL; 1500 #endif 1501 else 1502 priv = PRIV_SYSCTL_WRITE; 1503 error = priv_check(req->td, priv); 1504 if (error) 1505 return (error); 1506 } 1507 1508 if (!oid->oid_handler) 1509 return (EINVAL); 1510 1511 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1512 arg1 = (int *)arg1 + indx; 1513 arg2 -= indx; 1514 } else { 1515 arg1 = oid->oid_arg1; 1516 arg2 = oid->oid_arg2; 1517 } 1518 #ifdef MAC 1519 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2, 1520 req); 1521 if (error != 0) 1522 return (error); 1523 #endif 1524 oid->oid_running++; 1525 SYSCTL_XUNLOCK(); 1526 #ifdef VIMAGE 1527 if ((oid->oid_kind & CTLFLAG_VNET) && arg1 != NULL) 1528 arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1); 1529 #endif 1530 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 1531 mtx_lock(&Giant); 1532 error = oid->oid_handler(oid, arg1, arg2, req); 1533 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 1534 mtx_unlock(&Giant); 1535 1536 KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error); 1537 1538 SYSCTL_XLOCK(); 1539 oid->oid_running--; 1540 if (oid->oid_running == 0 && (oid->oid_kind & CTLFLAG_DYING) != 0) 1541 wakeup(&oid->oid_running); 1542 return (error); 1543 } 1544 1545 #ifndef _SYS_SYSPROTO_H_ 1546 struct sysctl_args { 1547 int *name; 1548 u_int namelen; 1549 void *old; 1550 size_t *oldlenp; 1551 void *new; 1552 size_t newlen; 1553 }; 1554 #endif 1555 int 1556 sys___sysctl(struct thread *td, struct sysctl_args *uap) 1557 { 1558 int error, i, name[CTL_MAXNAME]; 1559 size_t j; 1560 1561 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 1562 return (EINVAL); 1563 1564 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 1565 if (error) 1566 return (error); 1567 1568 error = userland_sysctl(td, name, uap->namelen, 1569 uap->old, uap->oldlenp, 0, 1570 uap->new, uap->newlen, &j, 0); 1571 if (error && error != ENOMEM) 1572 return (error); 1573 if (uap->oldlenp) { 1574 i = copyout(&j, uap->oldlenp, sizeof(j)); 1575 if (i) 1576 return (i); 1577 } 1578 return (error); 1579 } 1580 1581 /* 1582 * This is used from various compatibility syscalls too. That's why name 1583 * must be in kernel space. 1584 */ 1585 int 1586 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1587 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval, 1588 int flags) 1589 { 1590 int error = 0, memlocked; 1591 struct sysctl_req req; 1592 1593 bzero(&req, sizeof req); 1594 1595 req.td = td; 1596 req.flags = flags; 1597 1598 if (oldlenp) { 1599 if (inkernel) { 1600 req.oldlen = *oldlenp; 1601 } else { 1602 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 1603 if (error) 1604 return (error); 1605 } 1606 } 1607 req.validlen = req.oldlen; 1608 1609 if (old) { 1610 if (!useracc(old, req.oldlen, VM_PROT_WRITE)) 1611 return (EFAULT); 1612 req.oldptr= old; 1613 } 1614 1615 if (new != NULL) { 1616 if (!useracc(new, newlen, VM_PROT_READ)) 1617 return (EFAULT); 1618 req.newlen = newlen; 1619 req.newptr = new; 1620 } 1621 1622 req.oldfunc = sysctl_old_user; 1623 req.newfunc = sysctl_new_user; 1624 req.lock = REQ_UNWIRED; 1625 1626 #ifdef KTRACE 1627 if (KTRPOINT(curthread, KTR_SYSCTL)) 1628 ktrsysctl(name, namelen); 1629 #endif 1630 1631 if (req.oldlen > PAGE_SIZE) { 1632 memlocked = 1; 1633 sx_xlock(&sysctlmemlock); 1634 } else 1635 memlocked = 0; 1636 CURVNET_SET(TD_TO_VNET(td)); 1637 1638 for (;;) { 1639 req.oldidx = 0; 1640 req.newidx = 0; 1641 SYSCTL_XLOCK(); 1642 error = sysctl_root(0, name, namelen, &req); 1643 SYSCTL_XUNLOCK(); 1644 if (error != EAGAIN) 1645 break; 1646 kern_yield(PRI_USER); 1647 } 1648 1649 CURVNET_RESTORE(); 1650 1651 if (req.lock == REQ_WIRED && req.validlen > 0) 1652 vsunlock(req.oldptr, req.validlen); 1653 if (memlocked) 1654 sx_xunlock(&sysctlmemlock); 1655 1656 if (error && error != ENOMEM) 1657 return (error); 1658 1659 if (retval) { 1660 if (req.oldptr && req.oldidx > req.validlen) 1661 *retval = req.validlen; 1662 else 1663 *retval = req.oldidx; 1664 } 1665 return (error); 1666 } 1667 1668 /* 1669 * Drain into a sysctl struct. The user buffer should be wired if a page 1670 * fault would cause issue. 1671 */ 1672 static int 1673 sbuf_sysctl_drain(void *arg, const char *data, int len) 1674 { 1675 struct sysctl_req *req = arg; 1676 int error; 1677 1678 error = SYSCTL_OUT(req, data, len); 1679 KASSERT(error >= 0, ("Got unexpected negative value %d", error)); 1680 return (error == 0 ? len : -error); 1681 } 1682 1683 struct sbuf * 1684 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length, 1685 struct sysctl_req *req) 1686 { 1687 1688 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN); 1689 sbuf_set_drain(s, sbuf_sysctl_drain, req); 1690 return (s); 1691 }
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