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/10.3/sys/kern/kern_sysctl.c 283171 2015-05-21 06:30:44Z hselasky $"); 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 * accomodate 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 occured. 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("can't remove non-dynamic nodes!\n"); 433 return (EINVAL); 434 } 435 /* 436 * WARNING: normal method to do this should be through 437 * sysctl_ctx_free(). Use recursing as the last resort 438 * method to purge your sysctl tree of leftovers... 439 * However, if some other code still references these nodes, 440 * it will panic. 441 */ 442 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 443 if (oidp->oid_refcnt == 1) { 444 SLIST_FOREACH_SAFE(p, 445 SYSCTL_CHILDREN(oidp), oid_link, tmp) { 446 if (!recurse) { 447 printf("Warning: failed attempt to " 448 "remove oid %s with child %s\n", 449 oidp->oid_name, p->oid_name); 450 return (ENOTEMPTY); 451 } 452 error = sysctl_remove_oid_locked(p, del, 453 recurse); 454 if (error) 455 return (error); 456 } 457 if (del) 458 free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID); 459 } 460 } 461 if (oidp->oid_refcnt > 1 ) { 462 oidp->oid_refcnt--; 463 } else { 464 if (oidp->oid_refcnt == 0) { 465 printf("Warning: bad oid_refcnt=%u (%s)!\n", 466 oidp->oid_refcnt, oidp->oid_name); 467 return (EINVAL); 468 } 469 sysctl_unregister_oid(oidp); 470 if (del) { 471 /* 472 * Wait for all threads running the handler to drain. 473 * This preserves the previous behavior when the 474 * sysctl lock was held across a handler invocation, 475 * and is necessary for module unload correctness. 476 */ 477 while (oidp->oid_running > 0) { 478 oidp->oid_kind |= CTLFLAG_DYING; 479 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0); 480 } 481 if (oidp->oid_descr) 482 free(__DECONST(char *, oidp->oid_descr), 483 M_SYSCTLOID); 484 free(__DECONST(char *, oidp->oid_name), M_SYSCTLOID); 485 free(oidp, M_SYSCTLOID); 486 } 487 } 488 return (0); 489 } 490 /* 491 * Create new sysctls at run time. 492 * clist may point to a valid context initialized with sysctl_ctx_init(). 493 */ 494 struct sysctl_oid * 495 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, 496 int number, const char *name, int kind, void *arg1, intptr_t arg2, 497 int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr) 498 { 499 struct sysctl_oid *oidp; 500 501 /* You have to hook up somewhere.. */ 502 if (parent == NULL) 503 return(NULL); 504 /* Check if the node already exists, otherwise create it */ 505 SYSCTL_XLOCK(); 506 oidp = sysctl_find_oidname(name, parent); 507 if (oidp != NULL) { 508 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 509 oidp->oid_refcnt++; 510 /* Update the context */ 511 if (clist != NULL) 512 sysctl_ctx_entry_add(clist, oidp); 513 SYSCTL_XUNLOCK(); 514 return (oidp); 515 } else { 516 SYSCTL_XUNLOCK(); 517 printf("can't re-use a leaf (%s)!\n", name); 518 return (NULL); 519 } 520 } 521 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO); 522 oidp->oid_parent = parent; 523 SLIST_NEXT(oidp, oid_link) = NULL; 524 oidp->oid_number = number; 525 oidp->oid_refcnt = 1; 526 oidp->oid_name = strdup(name, M_SYSCTLOID); 527 oidp->oid_handler = handler; 528 oidp->oid_kind = CTLFLAG_DYN | kind; 529 if ((kind & CTLTYPE) == CTLTYPE_NODE) { 530 /* Allocate space for children */ 531 SYSCTL_CHILDREN_SET(oidp, malloc(sizeof(struct sysctl_oid_list), 532 M_SYSCTLOID, M_WAITOK)); 533 SLIST_INIT(SYSCTL_CHILDREN(oidp)); 534 oidp->oid_arg2 = arg2; 535 } else { 536 oidp->oid_arg1 = arg1; 537 oidp->oid_arg2 = arg2; 538 } 539 oidp->oid_fmt = fmt; 540 if (descr) 541 oidp->oid_descr = strdup(descr, M_SYSCTLOID); 542 /* Update the context, if used */ 543 if (clist != NULL) 544 sysctl_ctx_entry_add(clist, oidp); 545 /* Register this oid */ 546 sysctl_register_oid(oidp); 547 SYSCTL_XUNLOCK(); 548 return (oidp); 549 } 550 551 /* 552 * Rename an existing oid. 553 */ 554 void 555 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) 556 { 557 char *newname; 558 char *oldname; 559 560 newname = strdup(name, M_SYSCTLOID); 561 SYSCTL_XLOCK(); 562 oldname = __DECONST(char *, oidp->oid_name); 563 oidp->oid_name = newname; 564 SYSCTL_XUNLOCK(); 565 free(oldname, M_SYSCTLOID); 566 } 567 568 /* 569 * Reparent an existing oid. 570 */ 571 int 572 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent) 573 { 574 struct sysctl_oid *oidp; 575 576 SYSCTL_XLOCK(); 577 if (oid->oid_parent == parent) { 578 SYSCTL_XUNLOCK(); 579 return (0); 580 } 581 oidp = sysctl_find_oidname(oid->oid_name, parent); 582 if (oidp != NULL) { 583 SYSCTL_XUNLOCK(); 584 return (EEXIST); 585 } 586 sysctl_unregister_oid(oid); 587 oid->oid_parent = parent; 588 oid->oid_number = OID_AUTO; 589 sysctl_register_oid(oid); 590 SYSCTL_XUNLOCK(); 591 return (0); 592 } 593 594 /* 595 * Register the kernel's oids on startup. 596 */ 597 SET_DECLARE(sysctl_set, struct sysctl_oid); 598 599 static void 600 sysctl_register_all(void *arg) 601 { 602 struct sysctl_oid **oidp; 603 604 sx_init(&sysctlmemlock, "sysctl mem"); 605 SYSCTL_INIT(); 606 SYSCTL_XLOCK(); 607 SET_FOREACH(oidp, sysctl_set) 608 sysctl_register_oid(*oidp); 609 SYSCTL_XUNLOCK(); 610 } 611 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0); 612 613 /* 614 * "Staff-functions" 615 * 616 * These functions implement a presently undocumented interface 617 * used by the sysctl program to walk the tree, and get the type 618 * so it can print the value. 619 * This interface is under work and consideration, and should probably 620 * be killed with a big axe by the first person who can find the time. 621 * (be aware though, that the proper interface isn't as obvious as it 622 * may seem, there are various conflicting requirements. 623 * 624 * {0,0} printf the entire MIB-tree. 625 * {0,1,...} return the name of the "..." OID. 626 * {0,2,...} return the next OID. 627 * {0,3} return the OID of the name in "new" 628 * {0,4,...} return the kind & format info for the "..." OID. 629 * {0,5,...} return the description the "..." OID. 630 */ 631 632 #ifdef SYSCTL_DEBUG 633 static void 634 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 635 { 636 int k; 637 struct sysctl_oid *oidp; 638 639 SYSCTL_ASSERT_XLOCKED(); 640 SLIST_FOREACH(oidp, l, oid_link) { 641 642 for (k=0; k<i; k++) 643 printf(" "); 644 645 printf("%d %s ", oidp->oid_number, oidp->oid_name); 646 647 printf("%c%c", 648 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 649 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 650 651 if (oidp->oid_handler) 652 printf(" *Handler"); 653 654 switch (oidp->oid_kind & CTLTYPE) { 655 case CTLTYPE_NODE: 656 printf(" Node\n"); 657 if (!oidp->oid_handler) { 658 sysctl_sysctl_debug_dump_node( 659 oidp->oid_arg1, i+2); 660 } 661 break; 662 case CTLTYPE_INT: printf(" Int\n"); break; 663 case CTLTYPE_UINT: printf(" u_int\n"); break; 664 case CTLTYPE_LONG: printf(" Long\n"); break; 665 case CTLTYPE_ULONG: printf(" u_long\n"); break; 666 case CTLTYPE_STRING: printf(" String\n"); break; 667 case CTLTYPE_U64: printf(" uint64_t\n"); break; 668 case CTLTYPE_S64: printf(" int64_t\n"); break; 669 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break; 670 default: printf("\n"); 671 } 672 673 } 674 } 675 676 static int 677 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 678 { 679 int error; 680 681 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 682 if (error) 683 return (error); 684 SYSCTL_XLOCK(); 685 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 686 SYSCTL_XUNLOCK(); 687 return (ENOENT); 688 } 689 690 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD, 691 0, 0, sysctl_sysctl_debug, "-", ""); 692 #endif 693 694 static int 695 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 696 { 697 int *name = (int *) arg1; 698 u_int namelen = arg2; 699 int error = 0; 700 struct sysctl_oid *oid; 701 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 702 char buf[10]; 703 704 SYSCTL_XLOCK(); 705 while (namelen) { 706 if (!lsp) { 707 snprintf(buf,sizeof(buf),"%d",*name); 708 if (req->oldidx) 709 error = SYSCTL_OUT(req, ".", 1); 710 if (!error) 711 error = SYSCTL_OUT(req, buf, strlen(buf)); 712 if (error) 713 goto out; 714 namelen--; 715 name++; 716 continue; 717 } 718 lsp2 = 0; 719 SLIST_FOREACH(oid, lsp, oid_link) { 720 if (oid->oid_number != *name) 721 continue; 722 723 if (req->oldidx) 724 error = SYSCTL_OUT(req, ".", 1); 725 if (!error) 726 error = SYSCTL_OUT(req, oid->oid_name, 727 strlen(oid->oid_name)); 728 if (error) 729 goto out; 730 731 namelen--; 732 name++; 733 734 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 735 break; 736 737 if (oid->oid_handler) 738 break; 739 740 lsp2 = SYSCTL_CHILDREN(oid); 741 break; 742 } 743 lsp = lsp2; 744 } 745 error = SYSCTL_OUT(req, "", 1); 746 out: 747 SYSCTL_XUNLOCK(); 748 return (error); 749 } 750 751 /* 752 * XXXRW/JA: Shouldn't return name data for nodes that we don't permit in 753 * capability mode. 754 */ 755 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_CAPRD, 756 sysctl_sysctl_name, ""); 757 758 static int 759 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 760 int *next, int *len, int level, struct sysctl_oid **oidpp) 761 { 762 struct sysctl_oid *oidp; 763 764 SYSCTL_ASSERT_XLOCKED(); 765 *len = level; 766 SLIST_FOREACH(oidp, lsp, oid_link) { 767 *next = oidp->oid_number; 768 *oidpp = oidp; 769 770 if (oidp->oid_kind & CTLFLAG_SKIP) 771 continue; 772 773 if (!namelen) { 774 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 775 return (0); 776 if (oidp->oid_handler) 777 /* We really should call the handler here...*/ 778 return (0); 779 lsp = SYSCTL_CHILDREN(oidp); 780 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 781 len, level+1, oidpp)) 782 return (0); 783 goto emptynode; 784 } 785 786 if (oidp->oid_number < *name) 787 continue; 788 789 if (oidp->oid_number > *name) { 790 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 791 return (0); 792 if (oidp->oid_handler) 793 return (0); 794 lsp = SYSCTL_CHILDREN(oidp); 795 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 796 next+1, len, level+1, oidpp)) 797 return (0); 798 goto next; 799 } 800 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 801 continue; 802 803 if (oidp->oid_handler) 804 continue; 805 806 lsp = SYSCTL_CHILDREN(oidp); 807 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 808 len, level+1, oidpp)) 809 return (0); 810 next: 811 namelen = 1; 812 emptynode: 813 *len = level; 814 } 815 return (1); 816 } 817 818 static int 819 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 820 { 821 int *name = (int *) arg1; 822 u_int namelen = arg2; 823 int i, j, error; 824 struct sysctl_oid *oid; 825 struct sysctl_oid_list *lsp = &sysctl__children; 826 int newoid[CTL_MAXNAME]; 827 828 SYSCTL_XLOCK(); 829 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 830 SYSCTL_XUNLOCK(); 831 if (i) 832 return (ENOENT); 833 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 834 return (error); 835 } 836 837 /* 838 * XXXRW/JA: Shouldn't return next data for nodes that we don't permit in 839 * capability mode. 840 */ 841 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_CAPRD, 842 sysctl_sysctl_next, ""); 843 844 static int 845 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) 846 { 847 struct sysctl_oid *oidp; 848 struct sysctl_oid_list *lsp = &sysctl__children; 849 char *p; 850 851 SYSCTL_ASSERT_XLOCKED(); 852 853 for (*len = 0; *len < CTL_MAXNAME;) { 854 p = strsep(&name, "."); 855 856 oidp = SLIST_FIRST(lsp); 857 for (;; oidp = SLIST_NEXT(oidp, oid_link)) { 858 if (oidp == NULL) 859 return (ENOENT); 860 if (strcmp(p, oidp->oid_name) == 0) 861 break; 862 } 863 *oid++ = oidp->oid_number; 864 (*len)++; 865 866 if (name == NULL || *name == '\0') { 867 if (oidpp) 868 *oidpp = oidp; 869 return (0); 870 } 871 872 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 873 break; 874 875 if (oidp->oid_handler) 876 break; 877 878 lsp = SYSCTL_CHILDREN(oidp); 879 } 880 return (ENOENT); 881 } 882 883 static int 884 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 885 { 886 char *p; 887 int error, oid[CTL_MAXNAME], len = 0; 888 struct sysctl_oid *op = 0; 889 890 if (!req->newlen) 891 return (ENOENT); 892 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 893 return (ENAMETOOLONG); 894 895 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK); 896 897 error = SYSCTL_IN(req, p, req->newlen); 898 if (error) { 899 free(p, M_SYSCTL); 900 return (error); 901 } 902 903 p [req->newlen] = '\0'; 904 905 SYSCTL_XLOCK(); 906 error = name2oid(p, oid, &len, &op); 907 SYSCTL_XUNLOCK(); 908 909 free(p, M_SYSCTL); 910 911 if (error) 912 return (error); 913 914 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 915 return (error); 916 } 917 918 /* 919 * XXXRW/JA: Shouldn't return name2oid data for nodes that we don't permit in 920 * capability mode. 921 */ 922 SYSCTL_PROC(_sysctl, 3, name2oid, 923 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE 924 | CTLFLAG_CAPRW, 0, 0, sysctl_sysctl_name2oid, "I", ""); 925 926 static int 927 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 928 { 929 struct sysctl_oid *oid; 930 int error; 931 932 SYSCTL_XLOCK(); 933 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 934 if (error) 935 goto out; 936 937 if (oid->oid_fmt == NULL) { 938 error = ENOENT; 939 goto out; 940 } 941 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 942 if (error) 943 goto out; 944 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 945 out: 946 SYSCTL_XUNLOCK(); 947 return (error); 948 } 949 950 951 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD, 952 sysctl_sysctl_oidfmt, ""); 953 954 static int 955 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 956 { 957 struct sysctl_oid *oid; 958 int error; 959 960 SYSCTL_XLOCK(); 961 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 962 if (error) 963 goto out; 964 965 if (oid->oid_descr == NULL) { 966 error = ENOENT; 967 goto out; 968 } 969 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 970 out: 971 SYSCTL_XUNLOCK(); 972 return (error); 973 } 974 975 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_CAPRD, 976 sysctl_sysctl_oiddescr, ""); 977 978 /* 979 * Default "handler" functions. 980 */ 981 982 /* 983 * Handle an int, signed or unsigned. 984 * Two cases: 985 * a variable: point arg1 at it. 986 * a constant: pass it in arg2. 987 */ 988 989 int 990 sysctl_handle_int(SYSCTL_HANDLER_ARGS) 991 { 992 int tmpout, error = 0; 993 994 /* 995 * Attempt to get a coherent snapshot by making a copy of the data. 996 */ 997 if (arg1) 998 tmpout = *(int *)arg1; 999 else 1000 tmpout = arg2; 1001 error = SYSCTL_OUT(req, &tmpout, sizeof(int)); 1002 1003 if (error || !req->newptr) 1004 return (error); 1005 1006 if (!arg1) 1007 error = EPERM; 1008 else 1009 error = SYSCTL_IN(req, arg1, sizeof(int)); 1010 return (error); 1011 } 1012 1013 /* 1014 * Based on on sysctl_handle_int() convert milliseconds into ticks. 1015 * Note: this is used by TCP. 1016 */ 1017 1018 int 1019 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) 1020 { 1021 int error, s, tt; 1022 1023 tt = *(int *)arg1; 1024 s = (int)((int64_t)tt * 1000 / hz); 1025 1026 error = sysctl_handle_int(oidp, &s, 0, req); 1027 if (error || !req->newptr) 1028 return (error); 1029 1030 tt = (int)((int64_t)s * hz / 1000); 1031 if (tt < 1) 1032 return (EINVAL); 1033 1034 *(int *)arg1 = tt; 1035 return (0); 1036 } 1037 1038 1039 /* 1040 * Handle a long, signed or unsigned. 1041 * Two cases: 1042 * a variable: point arg1 at it. 1043 * a constant: pass it in arg2. 1044 */ 1045 1046 int 1047 sysctl_handle_long(SYSCTL_HANDLER_ARGS) 1048 { 1049 int error = 0; 1050 long tmplong; 1051 #ifdef SCTL_MASK32 1052 int tmpint; 1053 #endif 1054 1055 /* 1056 * Attempt to get a coherent snapshot by making a copy of the data. 1057 */ 1058 if (arg1) 1059 tmplong = *(long *)arg1; 1060 else 1061 tmplong = arg2; 1062 #ifdef SCTL_MASK32 1063 if (req->flags & SCTL_MASK32) { 1064 tmpint = tmplong; 1065 error = SYSCTL_OUT(req, &tmpint, sizeof(int)); 1066 } else 1067 #endif 1068 error = SYSCTL_OUT(req, &tmplong, sizeof(long)); 1069 1070 if (error || !req->newptr) 1071 return (error); 1072 1073 if (!arg1) 1074 error = EPERM; 1075 #ifdef SCTL_MASK32 1076 else if (req->flags & SCTL_MASK32) { 1077 error = SYSCTL_IN(req, &tmpint, sizeof(int)); 1078 *(long *)arg1 = (long)tmpint; 1079 } 1080 #endif 1081 else 1082 error = SYSCTL_IN(req, arg1, sizeof(long)); 1083 return (error); 1084 } 1085 1086 /* 1087 * Handle a 64 bit int, signed or unsigned. 1088 * Two cases: 1089 * a variable: point arg1 at it. 1090 * a constant: pass it in arg2. 1091 */ 1092 int 1093 sysctl_handle_64(SYSCTL_HANDLER_ARGS) 1094 { 1095 int error = 0; 1096 uint64_t tmpout; 1097 1098 /* 1099 * Attempt to get a coherent snapshot by making a copy of the data. 1100 */ 1101 if (arg1) 1102 tmpout = *(uint64_t *)arg1; 1103 else 1104 tmpout = arg2; 1105 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t)); 1106 1107 if (error || !req->newptr) 1108 return (error); 1109 1110 if (!arg1) 1111 error = EPERM; 1112 else 1113 error = SYSCTL_IN(req, arg1, sizeof(uint64_t)); 1114 return (error); 1115 } 1116 1117 /* 1118 * Handle our generic '\0' terminated 'C' string. 1119 * Two cases: 1120 * a variable string: point arg1 at it, arg2 is max length. 1121 * a constant string: point arg1 at it, arg2 is zero. 1122 */ 1123 1124 int 1125 sysctl_handle_string(SYSCTL_HANDLER_ARGS) 1126 { 1127 int error=0; 1128 char *tmparg; 1129 size_t outlen; 1130 1131 /* 1132 * Attempt to get a coherent snapshot by copying to a 1133 * temporary kernel buffer. 1134 */ 1135 retry: 1136 outlen = strlen((char *)arg1)+1; 1137 tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK); 1138 1139 if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) { 1140 free(tmparg, M_SYSCTLTMP); 1141 goto retry; 1142 } 1143 1144 error = SYSCTL_OUT(req, tmparg, outlen); 1145 free(tmparg, M_SYSCTLTMP); 1146 1147 if (error || !req->newptr) 1148 return (error); 1149 1150 if ((req->newlen - req->newidx) >= arg2) { 1151 error = EINVAL; 1152 } else { 1153 arg2 = (req->newlen - req->newidx); 1154 error = SYSCTL_IN(req, arg1, arg2); 1155 ((char *)arg1)[arg2] = '\0'; 1156 } 1157 1158 return (error); 1159 } 1160 1161 /* 1162 * Handle any kind of opaque data. 1163 * arg1 points to it, arg2 is the size. 1164 */ 1165 1166 int 1167 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 1168 { 1169 int error, tries; 1170 u_int generation; 1171 struct sysctl_req req2; 1172 1173 /* 1174 * Attempt to get a coherent snapshot, by using the thread 1175 * pre-emption counter updated from within mi_switch() to 1176 * determine if we were pre-empted during a bcopy() or 1177 * copyout(). Make 3 attempts at doing this before giving up. 1178 * If we encounter an error, stop immediately. 1179 */ 1180 tries = 0; 1181 req2 = *req; 1182 retry: 1183 generation = curthread->td_generation; 1184 error = SYSCTL_OUT(req, arg1, arg2); 1185 if (error) 1186 return (error); 1187 tries++; 1188 if (generation != curthread->td_generation && tries < 3) { 1189 *req = req2; 1190 goto retry; 1191 } 1192 1193 error = SYSCTL_IN(req, arg1, arg2); 1194 1195 return (error); 1196 } 1197 1198 /* 1199 * Transfer functions to/from kernel space. 1200 * XXX: rather untested at this point 1201 */ 1202 static int 1203 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 1204 { 1205 size_t i = 0; 1206 1207 if (req->oldptr) { 1208 i = l; 1209 if (req->oldlen <= req->oldidx) 1210 i = 0; 1211 else 1212 if (i > req->oldlen - req->oldidx) 1213 i = req->oldlen - req->oldidx; 1214 if (i > 0) 1215 bcopy(p, (char *)req->oldptr + req->oldidx, i); 1216 } 1217 req->oldidx += l; 1218 if (req->oldptr && i != l) 1219 return (ENOMEM); 1220 return (0); 1221 } 1222 1223 static int 1224 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 1225 { 1226 if (!req->newptr) 1227 return (0); 1228 if (req->newlen - req->newidx < l) 1229 return (EINVAL); 1230 bcopy((char *)req->newptr + req->newidx, p, l); 1231 req->newidx += l; 1232 return (0); 1233 } 1234 1235 int 1236 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1237 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags) 1238 { 1239 int error = 0; 1240 struct sysctl_req req; 1241 1242 bzero(&req, sizeof req); 1243 1244 req.td = td; 1245 req.flags = flags; 1246 1247 if (oldlenp) { 1248 req.oldlen = *oldlenp; 1249 } 1250 req.validlen = req.oldlen; 1251 1252 if (old) { 1253 req.oldptr= old; 1254 } 1255 1256 if (new != NULL) { 1257 req.newlen = newlen; 1258 req.newptr = new; 1259 } 1260 1261 req.oldfunc = sysctl_old_kernel; 1262 req.newfunc = sysctl_new_kernel; 1263 req.lock = REQ_UNWIRED; 1264 1265 SYSCTL_XLOCK(); 1266 error = sysctl_root(0, name, namelen, &req); 1267 SYSCTL_XUNLOCK(); 1268 1269 if (req.lock == REQ_WIRED && req.validlen > 0) 1270 vsunlock(req.oldptr, req.validlen); 1271 1272 if (error && error != ENOMEM) 1273 return (error); 1274 1275 if (retval) { 1276 if (req.oldptr && req.oldidx > req.validlen) 1277 *retval = req.validlen; 1278 else 1279 *retval = req.oldidx; 1280 } 1281 return (error); 1282 } 1283 1284 int 1285 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp, 1286 void *new, size_t newlen, size_t *retval, int flags) 1287 { 1288 int oid[CTL_MAXNAME]; 1289 size_t oidlen, plen; 1290 int error; 1291 1292 oid[0] = 0; /* sysctl internal magic */ 1293 oid[1] = 3; /* name2oid */ 1294 oidlen = sizeof(oid); 1295 1296 error = kernel_sysctl(td, oid, 2, oid, &oidlen, 1297 (void *)name, strlen(name), &plen, flags); 1298 if (error) 1299 return (error); 1300 1301 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp, 1302 new, newlen, retval, flags); 1303 return (error); 1304 } 1305 1306 /* 1307 * Transfer function to/from user space. 1308 */ 1309 static int 1310 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1311 { 1312 size_t i, len, origidx; 1313 int error; 1314 1315 origidx = req->oldidx; 1316 req->oldidx += l; 1317 if (req->oldptr == NULL) 1318 return (0); 1319 /* 1320 * If we have not wired the user supplied buffer and we are currently 1321 * holding locks, drop a witness warning, as it's possible that 1322 * write operations to the user page can sleep. 1323 */ 1324 if (req->lock != REQ_WIRED) 1325 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1326 "sysctl_old_user()"); 1327 i = l; 1328 len = req->validlen; 1329 if (len <= origidx) 1330 i = 0; 1331 else { 1332 if (i > len - origidx) 1333 i = len - origidx; 1334 if (req->lock == REQ_WIRED) { 1335 error = copyout_nofault(p, (char *)req->oldptr + 1336 origidx, i); 1337 } else 1338 error = copyout(p, (char *)req->oldptr + origidx, i); 1339 if (error != 0) 1340 return (error); 1341 } 1342 if (i < l) 1343 return (ENOMEM); 1344 return (0); 1345 } 1346 1347 static int 1348 sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1349 { 1350 int error; 1351 1352 if (!req->newptr) 1353 return (0); 1354 if (req->newlen - req->newidx < l) 1355 return (EINVAL); 1356 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1357 "sysctl_new_user()"); 1358 error = copyin((char *)req->newptr + req->newidx, p, l); 1359 req->newidx += l; 1360 return (error); 1361 } 1362 1363 /* 1364 * Wire the user space destination buffer. If set to a value greater than 1365 * zero, the len parameter limits the maximum amount of wired memory. 1366 */ 1367 int 1368 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len) 1369 { 1370 int ret; 1371 size_t wiredlen; 1372 1373 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen; 1374 ret = 0; 1375 if (req->lock != REQ_WIRED && req->oldptr && 1376 req->oldfunc == sysctl_old_user) { 1377 if (wiredlen != 0) { 1378 ret = vslock(req->oldptr, wiredlen); 1379 if (ret != 0) { 1380 if (ret != ENOMEM) 1381 return (ret); 1382 wiredlen = 0; 1383 } 1384 } 1385 req->lock = REQ_WIRED; 1386 req->validlen = wiredlen; 1387 } 1388 return (0); 1389 } 1390 1391 int 1392 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1393 int *nindx, struct sysctl_req *req) 1394 { 1395 struct sysctl_oid_list *lsp; 1396 struct sysctl_oid *oid; 1397 int indx; 1398 1399 SYSCTL_ASSERT_XLOCKED(); 1400 lsp = &sysctl__children; 1401 indx = 0; 1402 while (indx < CTL_MAXNAME) { 1403 SLIST_FOREACH(oid, lsp, oid_link) { 1404 if (oid->oid_number == name[indx]) 1405 break; 1406 } 1407 if (oid == NULL) 1408 return (ENOENT); 1409 1410 indx++; 1411 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1412 if (oid->oid_handler != NULL || indx == namelen) { 1413 *noid = oid; 1414 if (nindx != NULL) 1415 *nindx = indx; 1416 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1417 ("%s found DYING node %p", __func__, oid)); 1418 return (0); 1419 } 1420 lsp = SYSCTL_CHILDREN(oid); 1421 } else if (indx == namelen) { 1422 *noid = oid; 1423 if (nindx != NULL) 1424 *nindx = indx; 1425 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1426 ("%s found DYING node %p", __func__, oid)); 1427 return (0); 1428 } else { 1429 return (ENOTDIR); 1430 } 1431 } 1432 return (ENOENT); 1433 } 1434 1435 /* 1436 * Traverse our tree, and find the right node, execute whatever it points 1437 * to, and return the resulting error code. 1438 */ 1439 1440 static int 1441 sysctl_root(SYSCTL_HANDLER_ARGS) 1442 { 1443 struct sysctl_oid *oid; 1444 int error, indx, lvl; 1445 1446 SYSCTL_ASSERT_XLOCKED(); 1447 1448 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1449 if (error) 1450 return (error); 1451 1452 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1453 /* 1454 * You can't call a sysctl when it's a node, but has 1455 * no handler. Inform the user that it's a node. 1456 * The indx may or may not be the same as namelen. 1457 */ 1458 if (oid->oid_handler == NULL) 1459 return (EISDIR); 1460 } 1461 1462 /* Is this sysctl writable? */ 1463 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) 1464 return (EPERM); 1465 1466 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL")); 1467 1468 #ifdef CAPABILITY_MODE 1469 /* 1470 * If the process is in capability mode, then don't permit reading or 1471 * writing unless specifically granted for the node. 1472 */ 1473 if (IN_CAPABILITY_MODE(req->td)) { 1474 if (req->oldptr && !(oid->oid_kind & CTLFLAG_CAPRD)) 1475 return (EPERM); 1476 if (req->newptr && !(oid->oid_kind & CTLFLAG_CAPWR)) 1477 return (EPERM); 1478 } 1479 #endif 1480 1481 /* Is this sysctl sensitive to securelevels? */ 1482 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) { 1483 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE; 1484 error = securelevel_gt(req->td->td_ucred, lvl); 1485 if (error) 1486 return (error); 1487 } 1488 1489 /* Is this sysctl writable by only privileged users? */ 1490 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) { 1491 int priv; 1492 1493 if (oid->oid_kind & CTLFLAG_PRISON) 1494 priv = PRIV_SYSCTL_WRITEJAIL; 1495 #ifdef VIMAGE 1496 else if ((oid->oid_kind & CTLFLAG_VNET) && 1497 prison_owns_vnet(req->td->td_ucred)) 1498 priv = PRIV_SYSCTL_WRITEJAIL; 1499 #endif 1500 else 1501 priv = PRIV_SYSCTL_WRITE; 1502 error = priv_check(req->td, priv); 1503 if (error) 1504 return (error); 1505 } 1506 1507 if (!oid->oid_handler) 1508 return (EINVAL); 1509 1510 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1511 arg1 = (int *)arg1 + indx; 1512 arg2 -= indx; 1513 } else { 1514 arg1 = oid->oid_arg1; 1515 arg2 = oid->oid_arg2; 1516 } 1517 #ifdef MAC 1518 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2, 1519 req); 1520 if (error != 0) 1521 return (error); 1522 #endif 1523 oid->oid_running++; 1524 SYSCTL_XUNLOCK(); 1525 #ifdef VIMAGE 1526 if ((oid->oid_kind & CTLFLAG_VNET) && arg1 != NULL) 1527 arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1); 1528 #endif 1529 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 1530 mtx_lock(&Giant); 1531 error = oid->oid_handler(oid, arg1, arg2, req); 1532 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 1533 mtx_unlock(&Giant); 1534 1535 KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error); 1536 1537 SYSCTL_XLOCK(); 1538 oid->oid_running--; 1539 if (oid->oid_running == 0 && (oid->oid_kind & CTLFLAG_DYING) != 0) 1540 wakeup(&oid->oid_running); 1541 return (error); 1542 } 1543 1544 #ifndef _SYS_SYSPROTO_H_ 1545 struct sysctl_args { 1546 int *name; 1547 u_int namelen; 1548 void *old; 1549 size_t *oldlenp; 1550 void *new; 1551 size_t newlen; 1552 }; 1553 #endif 1554 int 1555 sys___sysctl(struct thread *td, struct sysctl_args *uap) 1556 { 1557 int error, i, name[CTL_MAXNAME]; 1558 size_t j; 1559 1560 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 1561 return (EINVAL); 1562 1563 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 1564 if (error) 1565 return (error); 1566 1567 error = userland_sysctl(td, name, uap->namelen, 1568 uap->old, uap->oldlenp, 0, 1569 uap->new, uap->newlen, &j, 0); 1570 if (error && error != ENOMEM) 1571 return (error); 1572 if (uap->oldlenp) { 1573 i = copyout(&j, uap->oldlenp, sizeof(j)); 1574 if (i) 1575 return (i); 1576 } 1577 return (error); 1578 } 1579 1580 /* 1581 * This is used from various compatibility syscalls too. That's why name 1582 * must be in kernel space. 1583 */ 1584 int 1585 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1586 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval, 1587 int flags) 1588 { 1589 int error = 0, memlocked; 1590 struct sysctl_req req; 1591 1592 bzero(&req, sizeof req); 1593 1594 req.td = td; 1595 req.flags = flags; 1596 1597 if (oldlenp) { 1598 if (inkernel) { 1599 req.oldlen = *oldlenp; 1600 } else { 1601 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 1602 if (error) 1603 return (error); 1604 } 1605 } 1606 req.validlen = req.oldlen; 1607 1608 if (old) { 1609 if (!useracc(old, req.oldlen, VM_PROT_WRITE)) 1610 return (EFAULT); 1611 req.oldptr= old; 1612 } 1613 1614 if (new != NULL) { 1615 if (!useracc(new, newlen, VM_PROT_READ)) 1616 return (EFAULT); 1617 req.newlen = newlen; 1618 req.newptr = new; 1619 } 1620 1621 req.oldfunc = sysctl_old_user; 1622 req.newfunc = sysctl_new_user; 1623 req.lock = REQ_UNWIRED; 1624 1625 #ifdef KTRACE 1626 if (KTRPOINT(curthread, KTR_SYSCTL)) 1627 ktrsysctl(name, namelen); 1628 #endif 1629 1630 if (req.oldlen > PAGE_SIZE) { 1631 memlocked = 1; 1632 sx_xlock(&sysctlmemlock); 1633 } else 1634 memlocked = 0; 1635 CURVNET_SET(TD_TO_VNET(td)); 1636 1637 for (;;) { 1638 req.oldidx = 0; 1639 req.newidx = 0; 1640 SYSCTL_XLOCK(); 1641 error = sysctl_root(0, name, namelen, &req); 1642 SYSCTL_XUNLOCK(); 1643 if (error != EAGAIN) 1644 break; 1645 kern_yield(PRI_USER); 1646 } 1647 1648 CURVNET_RESTORE(); 1649 1650 if (req.lock == REQ_WIRED && req.validlen > 0) 1651 vsunlock(req.oldptr, req.validlen); 1652 if (memlocked) 1653 sx_xunlock(&sysctlmemlock); 1654 1655 if (error && error != ENOMEM) 1656 return (error); 1657 1658 if (retval) { 1659 if (req.oldptr && req.oldidx > req.validlen) 1660 *retval = req.validlen; 1661 else 1662 *retval = req.oldidx; 1663 } 1664 return (error); 1665 } 1666 1667 /* 1668 * Drain into a sysctl struct. The user buffer should be wired if a page 1669 * fault would cause issue. 1670 */ 1671 static int 1672 sbuf_sysctl_drain(void *arg, const char *data, int len) 1673 { 1674 struct sysctl_req *req = arg; 1675 int error; 1676 1677 error = SYSCTL_OUT(req, data, len); 1678 KASSERT(error >= 0, ("Got unexpected negative value %d", error)); 1679 return (error == 0 ? len : -error); 1680 } 1681 1682 struct sbuf * 1683 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length, 1684 struct sysctl_req *req) 1685 { 1686 1687 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN); 1688 sbuf_set_drain(s, sbuf_sysctl_drain, req); 1689 return (s); 1690 }
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