1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Mike Karels at Berkeley Software Design, Inc. 7 * 8 * Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD 9 * project, to make these variables more userfriendly. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)kern_sysctl.c 8.4 (Berkeley) 4/14/94 36 */ 37 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include "opt_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((void *)(uintptr_t)(const void *)oidp->oid_descr, M_SYSCTLOID); 448 free((void *)(uintptr_t)(const void *)oidp->oid_name, 449 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 ssize_t len; 466 char *newname; 467 468 /* You have to hook up somewhere.. */ 469 if (parent == NULL) 470 return(NULL); 471 /* Check if the node already exists, otherwise create it */ 472 SYSCTL_XLOCK(); 473 oidp = sysctl_find_oidname(name, parent); 474 if (oidp != NULL) { 475 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 476 oidp->oid_refcnt++; 477 /* Update the context */ 478 if (clist != NULL) 479 sysctl_ctx_entry_add(clist, oidp); 480 SYSCTL_XUNLOCK(); 481 return (oidp); 482 } else { 483 SYSCTL_XUNLOCK(); 484 printf("can't re-use a leaf (%s)!\n", name); 485 return (NULL); 486 } 487 } 488 oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO); 489 oidp->oid_parent = parent; 490 SLIST_NEXT(oidp, oid_link) = NULL; 491 oidp->oid_number = number; 492 oidp->oid_refcnt = 1; 493 len = strlen(name); 494 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK); 495 bcopy(name, newname, len + 1); 496 newname[len] = '\0'; 497 oidp->oid_name = newname; 498 oidp->oid_handler = handler; 499 oidp->oid_kind = CTLFLAG_DYN | kind; 500 if ((kind & CTLTYPE) == CTLTYPE_NODE) { 501 /* Allocate space for children */ 502 SYSCTL_CHILDREN_SET(oidp, malloc(sizeof(struct sysctl_oid_list), 503 M_SYSCTLOID, M_WAITOK)); 504 SLIST_INIT(SYSCTL_CHILDREN(oidp)); 505 oidp->oid_arg2 = arg2; 506 } else { 507 oidp->oid_arg1 = arg1; 508 oidp->oid_arg2 = arg2; 509 } 510 oidp->oid_fmt = fmt; 511 if (descr) { 512 int len = strlen(descr) + 1; 513 oidp->oid_descr = malloc(len, M_SYSCTLOID, M_WAITOK); 514 if (oidp->oid_descr) 515 strcpy((char *)(uintptr_t)(const void *)oidp->oid_descr, descr); 516 } 517 /* Update the context, if used */ 518 if (clist != NULL) 519 sysctl_ctx_entry_add(clist, oidp); 520 /* Register this oid */ 521 sysctl_register_oid(oidp); 522 SYSCTL_XUNLOCK(); 523 return (oidp); 524 } 525 526 /* 527 * Rename an existing oid. 528 */ 529 void 530 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) 531 { 532 ssize_t len; 533 char *newname; 534 void *oldname; 535 536 len = strlen(name); 537 newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK); 538 bcopy(name, newname, len + 1); 539 newname[len] = '\0'; 540 SYSCTL_XLOCK(); 541 oldname = (void *)(uintptr_t)(const void *)oidp->oid_name; 542 oidp->oid_name = newname; 543 SYSCTL_XUNLOCK(); 544 free(oldname, M_SYSCTLOID); 545 } 546 547 /* 548 * Reparent an existing oid. 549 */ 550 int 551 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent) 552 { 553 struct sysctl_oid *oidp; 554 555 SYSCTL_XLOCK(); 556 if (oid->oid_parent == parent) { 557 SYSCTL_XUNLOCK(); 558 return (0); 559 } 560 oidp = sysctl_find_oidname(oid->oid_name, parent); 561 if (oidp != NULL) { 562 SYSCTL_XUNLOCK(); 563 return (EEXIST); 564 } 565 sysctl_unregister_oid(oid); 566 oid->oid_parent = parent; 567 oid->oid_number = OID_AUTO; 568 sysctl_register_oid(oid); 569 SYSCTL_XUNLOCK(); 570 return (0); 571 } 572 573 /* 574 * Register the kernel's oids on startup. 575 */ 576 SET_DECLARE(sysctl_set, struct sysctl_oid); 577 578 static void 579 sysctl_register_all(void *arg) 580 { 581 struct sysctl_oid **oidp; 582 583 sx_init(&sysctlmemlock, "sysctl mem"); 584 SYSCTL_INIT(); 585 SYSCTL_XLOCK(); 586 SET_FOREACH(oidp, sysctl_set) 587 sysctl_register_oid(*oidp); 588 SYSCTL_XUNLOCK(); 589 } 590 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0); 591 592 /* 593 * "Staff-functions" 594 * 595 * These functions implement a presently undocumented interface 596 * used by the sysctl program to walk the tree, and get the type 597 * so it can print the value. 598 * This interface is under work and consideration, and should probably 599 * be killed with a big axe by the first person who can find the time. 600 * (be aware though, that the proper interface isn't as obvious as it 601 * may seem, there are various conflicting requirements. 602 * 603 * {0,0} printf the entire MIB-tree. 604 * {0,1,...} return the name of the "..." OID. 605 * {0,2,...} return the next OID. 606 * {0,3} return the OID of the name in "new" 607 * {0,4,...} return the kind & format info for the "..." OID. 608 * {0,5,...} return the description the "..." OID. 609 */ 610 611 #ifdef SYSCTL_DEBUG 612 static void 613 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) 614 { 615 int k; 616 struct sysctl_oid *oidp; 617 618 SYSCTL_ASSERT_XLOCKED(); 619 SLIST_FOREACH(oidp, l, oid_link) { 620 621 for (k=0; k<i; k++) 622 printf(" "); 623 624 printf("%d %s ", oidp->oid_number, oidp->oid_name); 625 626 printf("%c%c", 627 oidp->oid_kind & CTLFLAG_RD ? 'R':' ', 628 oidp->oid_kind & CTLFLAG_WR ? 'W':' '); 629 630 if (oidp->oid_handler) 631 printf(" *Handler"); 632 633 switch (oidp->oid_kind & CTLTYPE) { 634 case CTLTYPE_NODE: 635 printf(" Node\n"); 636 if (!oidp->oid_handler) { 637 sysctl_sysctl_debug_dump_node( 638 oidp->oid_arg1, i+2); 639 } 640 break; 641 case CTLTYPE_INT: printf(" Int\n"); break; 642 case CTLTYPE_UINT: printf(" u_int\n"); break; 643 case CTLTYPE_LONG: printf(" Long\n"); break; 644 case CTLTYPE_ULONG: printf(" u_long\n"); break; 645 case CTLTYPE_STRING: printf(" String\n"); break; 646 case CTLTYPE_U64: printf(" uint64_t\n"); break; 647 case CTLTYPE_S64: printf(" int64_t\n"); break; 648 case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break; 649 default: printf("\n"); 650 } 651 652 } 653 } 654 655 static int 656 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) 657 { 658 int error; 659 660 error = priv_check(req->td, PRIV_SYSCTL_DEBUG); 661 if (error) 662 return (error); 663 SYSCTL_XLOCK(); 664 sysctl_sysctl_debug_dump_node(&sysctl__children, 0); 665 SYSCTL_XUNLOCK(); 666 return (ENOENT); 667 } 668 669 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD, 670 0, 0, sysctl_sysctl_debug, "-", ""); 671 #endif 672 673 static int 674 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) 675 { 676 int *name = (int *) arg1; 677 u_int namelen = arg2; 678 int error = 0; 679 struct sysctl_oid *oid; 680 struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; 681 char buf[10]; 682 683 SYSCTL_XLOCK(); 684 while (namelen) { 685 if (!lsp) { 686 snprintf(buf,sizeof(buf),"%d",*name); 687 if (req->oldidx) 688 error = SYSCTL_OUT(req, ".", 1); 689 if (!error) 690 error = SYSCTL_OUT(req, buf, strlen(buf)); 691 if (error) 692 goto out; 693 namelen--; 694 name++; 695 continue; 696 } 697 lsp2 = 0; 698 SLIST_FOREACH(oid, lsp, oid_link) { 699 if (oid->oid_number != *name) 700 continue; 701 702 if (req->oldidx) 703 error = SYSCTL_OUT(req, ".", 1); 704 if (!error) 705 error = SYSCTL_OUT(req, oid->oid_name, 706 strlen(oid->oid_name)); 707 if (error) 708 goto out; 709 710 namelen--; 711 name++; 712 713 if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 714 break; 715 716 if (oid->oid_handler) 717 break; 718 719 lsp2 = SYSCTL_CHILDREN(oid); 720 break; 721 } 722 lsp = lsp2; 723 } 724 error = SYSCTL_OUT(req, "", 1); 725 out: 726 SYSCTL_XUNLOCK(); 727 return (error); 728 } 729 730 /* 731 * XXXRW/JA: Shouldn't return name data for nodes that we don't permit in 732 * capability mode. 733 */ 734 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_CAPRD, 735 sysctl_sysctl_name, ""); 736 737 static int 738 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 739 int *next, int *len, int level, struct sysctl_oid **oidpp) 740 { 741 struct sysctl_oid *oidp; 742 743 SYSCTL_ASSERT_XLOCKED(); 744 *len = level; 745 SLIST_FOREACH(oidp, lsp, oid_link) { 746 *next = oidp->oid_number; 747 *oidpp = oidp; 748 749 if (oidp->oid_kind & CTLFLAG_SKIP) 750 continue; 751 752 if (!namelen) { 753 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 754 return (0); 755 if (oidp->oid_handler) 756 /* We really should call the handler here...*/ 757 return (0); 758 lsp = SYSCTL_CHILDREN(oidp); 759 if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 760 len, level+1, oidpp)) 761 return (0); 762 goto emptynode; 763 } 764 765 if (oidp->oid_number < *name) 766 continue; 767 768 if (oidp->oid_number > *name) { 769 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 770 return (0); 771 if (oidp->oid_handler) 772 return (0); 773 lsp = SYSCTL_CHILDREN(oidp); 774 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 775 next+1, len, level+1, oidpp)) 776 return (0); 777 goto next; 778 } 779 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 780 continue; 781 782 if (oidp->oid_handler) 783 continue; 784 785 lsp = SYSCTL_CHILDREN(oidp); 786 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 787 len, level+1, oidpp)) 788 return (0); 789 next: 790 namelen = 1; 791 emptynode: 792 *len = level; 793 } 794 return (1); 795 } 796 797 static int 798 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) 799 { 800 int *name = (int *) arg1; 801 u_int namelen = arg2; 802 int i, j, error; 803 struct sysctl_oid *oid; 804 struct sysctl_oid_list *lsp = &sysctl__children; 805 int newoid[CTL_MAXNAME]; 806 807 SYSCTL_XLOCK(); 808 i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); 809 SYSCTL_XUNLOCK(); 810 if (i) 811 return (ENOENT); 812 error = SYSCTL_OUT(req, newoid, j * sizeof (int)); 813 return (error); 814 } 815 816 /* 817 * XXXRW/JA: Shouldn't return next data for nodes that we don't permit in 818 * capability mode. 819 */ 820 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_CAPRD, 821 sysctl_sysctl_next, ""); 822 823 static int 824 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) 825 { 826 int i; 827 struct sysctl_oid *oidp; 828 struct sysctl_oid_list *lsp = &sysctl__children; 829 char *p; 830 831 SYSCTL_ASSERT_XLOCKED(); 832 833 if (!*name) 834 return (ENOENT); 835 836 p = name + strlen(name) - 1 ; 837 if (*p == '.') 838 *p = '\0'; 839 840 *len = 0; 841 842 for (p = name; *p && *p != '.'; p++) 843 ; 844 i = *p; 845 if (i == '.') 846 *p = '\0'; 847 848 oidp = SLIST_FIRST(lsp); 849 850 while (oidp && *len < CTL_MAXNAME) { 851 if (strcmp(name, oidp->oid_name)) { 852 oidp = SLIST_NEXT(oidp, oid_link); 853 continue; 854 } 855 *oid++ = oidp->oid_number; 856 (*len)++; 857 858 if (!i) { 859 if (oidpp) 860 *oidpp = oidp; 861 return (0); 862 } 863 864 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 865 break; 866 867 if (oidp->oid_handler) 868 break; 869 870 lsp = SYSCTL_CHILDREN(oidp); 871 oidp = SLIST_FIRST(lsp); 872 name = p+1; 873 for (p = name; *p && *p != '.'; p++) 874 ; 875 i = *p; 876 if (i == '.') 877 *p = '\0'; 878 } 879 return (ENOENT); 880 } 881 882 static int 883 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) 884 { 885 char *p; 886 int error, oid[CTL_MAXNAME], len = 0; 887 struct sysctl_oid *op = 0; 888 889 if (!req->newlen) 890 return (ENOENT); 891 if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ 892 return (ENAMETOOLONG); 893 894 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK); 895 896 error = SYSCTL_IN(req, p, req->newlen); 897 if (error) { 898 free(p, M_SYSCTL); 899 return (error); 900 } 901 902 p [req->newlen] = '\0'; 903 904 SYSCTL_XLOCK(); 905 error = name2oid(p, oid, &len, &op); 906 SYSCTL_XUNLOCK(); 907 908 free(p, M_SYSCTL); 909 910 if (error) 911 return (error); 912 913 error = SYSCTL_OUT(req, oid, len * sizeof *oid); 914 return (error); 915 } 916 917 /* 918 * XXXRW/JA: Shouldn't return name2oid data for nodes that we don't permit in 919 * capability mode. 920 */ 921 SYSCTL_PROC(_sysctl, 3, name2oid, 922 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE 923 | CTLFLAG_CAPRW, 0, 0, sysctl_sysctl_name2oid, "I", ""); 924 925 static int 926 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) 927 { 928 struct sysctl_oid *oid; 929 int error; 930 931 SYSCTL_XLOCK(); 932 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 933 if (error) 934 goto out; 935 936 if (oid->oid_fmt == NULL) { 937 error = ENOENT; 938 goto out; 939 } 940 error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); 941 if (error) 942 goto out; 943 error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); 944 out: 945 SYSCTL_XUNLOCK(); 946 return (error); 947 } 948 949 950 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD, 951 sysctl_sysctl_oidfmt, ""); 952 953 static int 954 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) 955 { 956 struct sysctl_oid *oid; 957 int error; 958 959 SYSCTL_XLOCK(); 960 error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); 961 if (error) 962 goto out; 963 964 if (oid->oid_descr == NULL) { 965 error = ENOENT; 966 goto out; 967 } 968 error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); 969 out: 970 SYSCTL_XUNLOCK(); 971 return (error); 972 } 973 974 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_CAPRD, 975 sysctl_sysctl_oiddescr, ""); 976 977 /* 978 * Default "handler" functions. 979 */ 980 981 /* 982 * Handle an int, signed or unsigned. 983 * Two cases: 984 * a variable: point arg1 at it. 985 * a constant: pass it in arg2. 986 */ 987 988 int 989 sysctl_handle_int(SYSCTL_HANDLER_ARGS) 990 { 991 int tmpout, error = 0; 992 993 /* 994 * Attempt to get a coherent snapshot by making a copy of the data. 995 */ 996 if (arg1) 997 tmpout = *(int *)arg1; 998 else 999 tmpout = arg2; 1000 error = SYSCTL_OUT(req, &tmpout, sizeof(int)); 1001 1002 if (error || !req->newptr) 1003 return (error); 1004 1005 if (!arg1) 1006 error = EPERM; 1007 else 1008 error = SYSCTL_IN(req, arg1, sizeof(int)); 1009 return (error); 1010 } 1011 1012 /* 1013 * Based on on sysctl_handle_int() convert milliseconds into ticks. 1014 * Note: this is used by TCP. 1015 */ 1016 1017 int 1018 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) 1019 { 1020 int error, s, tt; 1021 1022 tt = *(int *)arg1; 1023 s = (int)((int64_t)tt * 1000 / hz); 1024 1025 error = sysctl_handle_int(oidp, &s, 0, req); 1026 if (error || !req->newptr) 1027 return (error); 1028 1029 tt = (int)((int64_t)s * hz / 1000); 1030 if (tt < 1) 1031 return (EINVAL); 1032 1033 *(int *)arg1 = tt; 1034 return (0); 1035 } 1036 1037 1038 /* 1039 * Handle a long, signed or unsigned. arg1 points to it. 1040 */ 1041 1042 int 1043 sysctl_handle_long(SYSCTL_HANDLER_ARGS) 1044 { 1045 int error = 0; 1046 long tmplong; 1047 #ifdef SCTL_MASK32 1048 int tmpint; 1049 #endif 1050 1051 /* 1052 * Attempt to get a coherent snapshot by making a copy of the data. 1053 */ 1054 if (!arg1) 1055 return (EINVAL); 1056 tmplong = *(long *)arg1; 1057 #ifdef SCTL_MASK32 1058 if (req->flags & SCTL_MASK32) { 1059 tmpint = tmplong; 1060 error = SYSCTL_OUT(req, &tmpint, sizeof(int)); 1061 } else 1062 #endif 1063 error = SYSCTL_OUT(req, &tmplong, sizeof(long)); 1064 1065 if (error || !req->newptr) 1066 return (error); 1067 1068 #ifdef SCTL_MASK32 1069 if (req->flags & SCTL_MASK32) { 1070 error = SYSCTL_IN(req, &tmpint, sizeof(int)); 1071 *(long *)arg1 = (long)tmpint; 1072 } else 1073 #endif 1074 error = SYSCTL_IN(req, arg1, sizeof(long)); 1075 return (error); 1076 } 1077 1078 /* 1079 * Handle a 64 bit int, signed or unsigned. arg1 points to it. 1080 */ 1081 int 1082 sysctl_handle_64(SYSCTL_HANDLER_ARGS) 1083 { 1084 int error = 0; 1085 uint64_t tmpout; 1086 1087 /* 1088 * Attempt to get a coherent snapshot by making a copy of the data. 1089 */ 1090 if (!arg1) 1091 return (EINVAL); 1092 tmpout = *(uint64_t *)arg1; 1093 error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t)); 1094 1095 if (error || !req->newptr) 1096 return (error); 1097 1098 error = SYSCTL_IN(req, arg1, sizeof(uint64_t)); 1099 return (error); 1100 } 1101 1102 /* 1103 * Handle our generic '\0' terminated 'C' string. 1104 * Two cases: 1105 * a variable string: point arg1 at it, arg2 is max length. 1106 * a constant string: point arg1 at it, arg2 is zero. 1107 */ 1108 1109 int 1110 sysctl_handle_string(SYSCTL_HANDLER_ARGS) 1111 { 1112 int error=0; 1113 char *tmparg; 1114 size_t outlen; 1115 1116 /* 1117 * Attempt to get a coherent snapshot by copying to a 1118 * temporary kernel buffer. 1119 */ 1120 retry: 1121 outlen = strlen((char *)arg1)+1; 1122 tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK); 1123 1124 if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) { 1125 free(tmparg, M_SYSCTLTMP); 1126 goto retry; 1127 } 1128 1129 error = SYSCTL_OUT(req, tmparg, outlen); 1130 free(tmparg, M_SYSCTLTMP); 1131 1132 if (error || !req->newptr) 1133 return (error); 1134 1135 if ((req->newlen - req->newidx) >= arg2) { 1136 error = EINVAL; 1137 } else { 1138 arg2 = (req->newlen - req->newidx); 1139 error = SYSCTL_IN(req, arg1, arg2); 1140 ((char *)arg1)[arg2] = '\0'; 1141 } 1142 1143 return (error); 1144 } 1145 1146 /* 1147 * Handle any kind of opaque data. 1148 * arg1 points to it, arg2 is the size. 1149 */ 1150 1151 int 1152 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) 1153 { 1154 int error, tries; 1155 u_int generation; 1156 struct sysctl_req req2; 1157 1158 /* 1159 * Attempt to get a coherent snapshot, by using the thread 1160 * pre-emption counter updated from within mi_switch() to 1161 * determine if we were pre-empted during a bcopy() or 1162 * copyout(). Make 3 attempts at doing this before giving up. 1163 * If we encounter an error, stop immediately. 1164 */ 1165 tries = 0; 1166 req2 = *req; 1167 retry: 1168 generation = curthread->td_generation; 1169 error = SYSCTL_OUT(req, arg1, arg2); 1170 if (error) 1171 return (error); 1172 tries++; 1173 if (generation != curthread->td_generation && tries < 3) { 1174 *req = req2; 1175 goto retry; 1176 } 1177 1178 error = SYSCTL_IN(req, arg1, arg2); 1179 1180 return (error); 1181 } 1182 1183 /* 1184 * Transfer functions to/from kernel space. 1185 * XXX: rather untested at this point 1186 */ 1187 static int 1188 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) 1189 { 1190 size_t i = 0; 1191 1192 if (req->oldptr) { 1193 i = l; 1194 if (req->oldlen <= req->oldidx) 1195 i = 0; 1196 else 1197 if (i > req->oldlen - req->oldidx) 1198 i = req->oldlen - req->oldidx; 1199 if (i > 0) 1200 bcopy(p, (char *)req->oldptr + req->oldidx, i); 1201 } 1202 req->oldidx += l; 1203 if (req->oldptr && i != l) 1204 return (ENOMEM); 1205 return (0); 1206 } 1207 1208 static int 1209 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) 1210 { 1211 if (!req->newptr) 1212 return (0); 1213 if (req->newlen - req->newidx < l) 1214 return (EINVAL); 1215 bcopy((char *)req->newptr + req->newidx, p, l); 1216 req->newidx += l; 1217 return (0); 1218 } 1219 1220 int 1221 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1222 size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags) 1223 { 1224 int error = 0; 1225 struct sysctl_req req; 1226 1227 bzero(&req, sizeof req); 1228 1229 req.td = td; 1230 req.flags = flags; 1231 1232 if (oldlenp) { 1233 req.oldlen = *oldlenp; 1234 } 1235 req.validlen = req.oldlen; 1236 1237 if (old) { 1238 req.oldptr= old; 1239 } 1240 1241 if (new != NULL) { 1242 req.newlen = newlen; 1243 req.newptr = new; 1244 } 1245 1246 req.oldfunc = sysctl_old_kernel; 1247 req.newfunc = sysctl_new_kernel; 1248 req.lock = REQ_UNWIRED; 1249 1250 SYSCTL_XLOCK(); 1251 error = sysctl_root(0, name, namelen, &req); 1252 SYSCTL_XUNLOCK(); 1253 1254 if (req.lock == REQ_WIRED && req.validlen > 0) 1255 vsunlock(req.oldptr, req.validlen); 1256 1257 if (error && error != ENOMEM) 1258 return (error); 1259 1260 if (retval) { 1261 if (req.oldptr && req.oldidx > req.validlen) 1262 *retval = req.validlen; 1263 else 1264 *retval = req.oldidx; 1265 } 1266 return (error); 1267 } 1268 1269 int 1270 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp, 1271 void *new, size_t newlen, size_t *retval, int flags) 1272 { 1273 int oid[CTL_MAXNAME]; 1274 size_t oidlen, plen; 1275 int error; 1276 1277 oid[0] = 0; /* sysctl internal magic */ 1278 oid[1] = 3; /* name2oid */ 1279 oidlen = sizeof(oid); 1280 1281 error = kernel_sysctl(td, oid, 2, oid, &oidlen, 1282 (void *)name, strlen(name), &plen, flags); 1283 if (error) 1284 return (error); 1285 1286 error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp, 1287 new, newlen, retval, flags); 1288 return (error); 1289 } 1290 1291 /* 1292 * Transfer function to/from user space. 1293 */ 1294 static int 1295 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) 1296 { 1297 int error = 0; 1298 size_t i, len, origidx; 1299 1300 origidx = req->oldidx; 1301 req->oldidx += l; 1302 if (req->oldptr == NULL) 1303 return (0); 1304 /* 1305 * If we have not wired the user supplied buffer and we are currently 1306 * holding locks, drop a witness warning, as it's possible that 1307 * write operations to the user page can sleep. 1308 */ 1309 if (req->lock != REQ_WIRED) 1310 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1311 "sysctl_old_user()"); 1312 i = l; 1313 len = req->validlen; 1314 if (len <= origidx) 1315 i = 0; 1316 else { 1317 if (i > len - origidx) 1318 i = len - origidx; 1319 error = copyout(p, (char *)req->oldptr + origidx, i); 1320 } 1321 if (error) 1322 return (error); 1323 if (i < l) 1324 return (ENOMEM); 1325 return (0); 1326 } 1327 1328 static int 1329 sysctl_new_user(struct sysctl_req *req, void *p, size_t l) 1330 { 1331 int error; 1332 1333 if (!req->newptr) 1334 return (0); 1335 if (req->newlen - req->newidx < l) 1336 return (EINVAL); 1337 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 1338 "sysctl_new_user()"); 1339 error = copyin((char *)req->newptr + req->newidx, p, l); 1340 req->newidx += l; 1341 return (error); 1342 } 1343 1344 /* 1345 * Wire the user space destination buffer. If set to a value greater than 1346 * zero, the len parameter limits the maximum amount of wired memory. 1347 */ 1348 int 1349 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len) 1350 { 1351 int ret; 1352 size_t wiredlen; 1353 1354 wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen; 1355 ret = 0; 1356 if (req->lock != REQ_WIRED && req->oldptr && 1357 req->oldfunc == sysctl_old_user) { 1358 if (wiredlen != 0) { 1359 ret = vslock(req->oldptr, wiredlen); 1360 if (ret != 0) { 1361 if (ret != ENOMEM) 1362 return (ret); 1363 wiredlen = 0; 1364 } 1365 } 1366 req->lock = REQ_WIRED; 1367 req->validlen = wiredlen; 1368 } 1369 return (0); 1370 } 1371 1372 int 1373 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, 1374 int *nindx, struct sysctl_req *req) 1375 { 1376 struct sysctl_oid_list *lsp; 1377 struct sysctl_oid *oid; 1378 int indx; 1379 1380 SYSCTL_ASSERT_XLOCKED(); 1381 lsp = &sysctl__children; 1382 indx = 0; 1383 while (indx < CTL_MAXNAME) { 1384 SLIST_FOREACH(oid, lsp, oid_link) { 1385 if (oid->oid_number == name[indx]) 1386 break; 1387 } 1388 if (oid == NULL) 1389 return (ENOENT); 1390 1391 indx++; 1392 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1393 if (oid->oid_handler != NULL || indx == namelen) { 1394 *noid = oid; 1395 if (nindx != NULL) 1396 *nindx = indx; 1397 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1398 ("%s found DYING node %p", __func__, oid)); 1399 return (0); 1400 } 1401 lsp = SYSCTL_CHILDREN(oid); 1402 } else if (indx == namelen) { 1403 *noid = oid; 1404 if (nindx != NULL) 1405 *nindx = indx; 1406 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, 1407 ("%s found DYING node %p", __func__, oid)); 1408 return (0); 1409 } else { 1410 return (ENOTDIR); 1411 } 1412 } 1413 return (ENOENT); 1414 } 1415 1416 /* 1417 * Traverse our tree, and find the right node, execute whatever it points 1418 * to, and return the resulting error code. 1419 */ 1420 1421 static int 1422 sysctl_root(SYSCTL_HANDLER_ARGS) 1423 { 1424 struct sysctl_oid *oid; 1425 int error, indx, lvl; 1426 1427 SYSCTL_ASSERT_XLOCKED(); 1428 1429 error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); 1430 if (error) 1431 return (error); 1432 1433 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1434 /* 1435 * You can't call a sysctl when it's a node, but has 1436 * no handler. Inform the user that it's a node. 1437 * The indx may or may not be the same as namelen. 1438 */ 1439 if (oid->oid_handler == NULL) 1440 return (EISDIR); 1441 } 1442 1443 /* Is this sysctl writable? */ 1444 if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) 1445 return (EPERM); 1446 1447 KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL")); 1448 1449 #ifdef CAPABILITY_MODE 1450 /* 1451 * If the process is in capability mode, then don't permit reading or 1452 * writing unless specifically granted for the node. 1453 */ 1454 if (IN_CAPABILITY_MODE(req->td)) { 1455 if (req->oldptr && !(oid->oid_kind & CTLFLAG_CAPRD)) 1456 return (EPERM); 1457 if (req->newptr && !(oid->oid_kind & CTLFLAG_CAPWR)) 1458 return (EPERM); 1459 } 1460 #endif 1461 1462 /* Is this sysctl sensitive to securelevels? */ 1463 if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) { 1464 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE; 1465 error = securelevel_gt(req->td->td_ucred, lvl); 1466 if (error) 1467 return (error); 1468 } 1469 1470 /* Is this sysctl writable by only privileged users? */ 1471 if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) { 1472 int priv; 1473 1474 if (oid->oid_kind & CTLFLAG_PRISON) 1475 priv = PRIV_SYSCTL_WRITEJAIL; 1476 #ifdef VIMAGE 1477 else if ((oid->oid_kind & CTLFLAG_VNET) && 1478 prison_owns_vnet(req->td->td_ucred)) 1479 priv = PRIV_SYSCTL_WRITEJAIL; 1480 #endif 1481 else 1482 priv = PRIV_SYSCTL_WRITE; 1483 error = priv_check(req->td, priv); 1484 if (error) 1485 return (error); 1486 } 1487 1488 if (!oid->oid_handler) 1489 return (EINVAL); 1490 1491 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { 1492 arg1 = (int *)arg1 + indx; 1493 arg2 -= indx; 1494 } else { 1495 arg1 = oid->oid_arg1; 1496 arg2 = oid->oid_arg2; 1497 } 1498 #ifdef MAC 1499 error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2, 1500 req); 1501 if (error != 0) 1502 return (error); 1503 #endif 1504 oid->oid_running++; 1505 SYSCTL_XUNLOCK(); 1506 1507 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 1508 mtx_lock(&Giant); 1509 error = oid->oid_handler(oid, arg1, arg2, req); 1510 if (!(oid->oid_kind & CTLFLAG_MPSAFE)) 1511 mtx_unlock(&Giant); 1512 1513 KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error); 1514 1515 SYSCTL_XLOCK(); 1516 oid->oid_running--; 1517 if (oid->oid_running == 0 && (oid->oid_kind & CTLFLAG_DYING) != 0) 1518 wakeup(&oid->oid_running); 1519 return (error); 1520 } 1521 1522 #ifndef _SYS_SYSPROTO_H_ 1523 struct sysctl_args { 1524 int *name; 1525 u_int namelen; 1526 void *old; 1527 size_t *oldlenp; 1528 void *new; 1529 size_t newlen; 1530 }; 1531 #endif 1532 int 1533 sys___sysctl(struct thread *td, struct sysctl_args *uap) 1534 { 1535 int error, i, name[CTL_MAXNAME]; 1536 size_t j; 1537 1538 if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) 1539 return (EINVAL); 1540 1541 error = copyin(uap->name, &name, uap->namelen * sizeof(int)); 1542 if (error) 1543 return (error); 1544 1545 error = userland_sysctl(td, name, uap->namelen, 1546 uap->old, uap->oldlenp, 0, 1547 uap->new, uap->newlen, &j, 0); 1548 if (error && error != ENOMEM) 1549 return (error); 1550 if (uap->oldlenp) { 1551 i = copyout(&j, uap->oldlenp, sizeof(j)); 1552 if (i) 1553 return (i); 1554 } 1555 return (error); 1556 } 1557 1558 /* 1559 * This is used from various compatibility syscalls too. That's why name 1560 * must be in kernel space. 1561 */ 1562 int 1563 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old, 1564 size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval, 1565 int flags) 1566 { 1567 int error = 0, memlocked; 1568 struct sysctl_req req; 1569 1570 bzero(&req, sizeof req); 1571 1572 req.td = td; 1573 req.flags = flags; 1574 1575 if (oldlenp) { 1576 if (inkernel) { 1577 req.oldlen = *oldlenp; 1578 } else { 1579 error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); 1580 if (error) 1581 return (error); 1582 } 1583 } 1584 req.validlen = req.oldlen; 1585 1586 if (old) { 1587 if (!useracc(old, req.oldlen, VM_PROT_WRITE)) 1588 return (EFAULT); 1589 req.oldptr= old; 1590 } 1591 1592 if (new != NULL) { 1593 if (!useracc(new, newlen, VM_PROT_READ)) 1594 return (EFAULT); 1595 req.newlen = newlen; 1596 req.newptr = new; 1597 } 1598 1599 req.oldfunc = sysctl_old_user; 1600 req.newfunc = sysctl_new_user; 1601 req.lock = REQ_UNWIRED; 1602 1603 #ifdef KTRACE 1604 if (KTRPOINT(curthread, KTR_SYSCTL)) 1605 ktrsysctl(name, namelen); 1606 #endif 1607 1608 if (req.oldlen > PAGE_SIZE) { 1609 memlocked = 1; 1610 sx_xlock(&sysctlmemlock); 1611 } else 1612 memlocked = 0; 1613 CURVNET_SET(TD_TO_VNET(td)); 1614 1615 for (;;) { 1616 req.oldidx = 0; 1617 req.newidx = 0; 1618 SYSCTL_XLOCK(); 1619 error = sysctl_root(0, name, namelen, &req); 1620 SYSCTL_XUNLOCK(); 1621 if (error != EAGAIN) 1622 break; 1623 kern_yield(PRI_USER); 1624 } 1625 1626 CURVNET_RESTORE(); 1627 1628 if (req.lock == REQ_WIRED && req.validlen > 0) 1629 vsunlock(req.oldptr, req.validlen); 1630 if (memlocked) 1631 sx_xunlock(&sysctlmemlock); 1632 1633 if (error && error != ENOMEM) 1634 return (error); 1635 1636 if (retval) { 1637 if (req.oldptr && req.oldidx > req.validlen) 1638 *retval = req.validlen; 1639 else 1640 *retval = req.oldidx; 1641 } 1642 return (error); 1643 } 1644 1645 /* 1646 * Drain into a sysctl struct. The user buffer should be wired if a page 1647 * fault would cause issue. 1648 */ 1649 static int 1650 sbuf_sysctl_drain(void *arg, const char *data, int len) 1651 { 1652 struct sysctl_req *req = arg; 1653 int error; 1654 1655 error = SYSCTL_OUT(req, data, len); 1656 KASSERT(error >= 0, ("Got unexpected negative value %d", error)); 1657 return (error == 0 ? len : -error); 1658 } 1659 1660 struct sbuf * 1661 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length, 1662 struct sysctl_req *req) 1663 { 1664 1665 s = sbuf_new(s, buf, length, SBUF_FIXEDLEN); 1666 sbuf_set_drain(s, sbuf_sysctl_drain, req); 1667 return (s); 1668 } 1669