sys/kern/kern_sysctl.c

   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/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/rmlock.h>
  58 #include <sys/sbuf.h>
  59 #include <sys/sx.h>
  60 #include <sys/sysproto.h>
  61 #include <sys/uio.h>
  62 #ifdef KTRACE
  63 #include <sys/ktrace.h>
  64 #endif
  65
  66 #include <net/vnet.h>
  67
  68 #include <security/mac/mac_framework.h>
  69
  70 #include <vm/vm.h>
  71 #include <vm/vm_extern.h>
  72
  73 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic");
  74 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids");
  75 static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer");
  76
  77 /*
  78  * The sysctllock protects the MIB tree.  It also protects sysctl
  79  * contexts used with dynamic sysctls.  The sysctl_register_oid() and
  80  * sysctl_unregister_oid() routines require the sysctllock to already
  81  * be held, so the sysctl_wlock() and sysctl_wunlock() routines are
  82  * provided for the few places in the kernel which need to use that
  83  * API rather than using the dynamic API.  Use of the dynamic API is
  84  * strongly encouraged for most code.
  85  *
  86  * The sysctlmemlock is used to limit the amount of user memory wired for
  87  * sysctl requests.  This is implemented by serializing any userland
  88  * sysctl requests larger than a single page via an exclusive lock.
  89  */
  90 static struct rmlock sysctllock;
  91 static struct sx sysctlmemlock;
  92
  93 #define SYSCTL_WLOCK()          rm_wlock(&sysctllock)
  94 #define SYSCTL_WUNLOCK()        rm_wunlock(&sysctllock)
  95 #define SYSCTL_RLOCK(tracker)   rm_rlock(&sysctllock, (tracker))
  96 #define SYSCTL_RUNLOCK(tracker) rm_runlock(&sysctllock, (tracker))
  97 #define SYSCTL_WLOCKED()        rm_wowned(&sysctllock)
  98 #define SYSCTL_ASSERT_LOCKED()  rm_assert(&sysctllock, RA_LOCKED)
  99 #define SYSCTL_ASSERT_WLOCKED() rm_assert(&sysctllock, RA_WLOCKED)
 100 #define SYSCTL_ASSERT_RLOCKED() rm_assert(&sysctllock, RA_RLOCKED)
 101 #define SYSCTL_INIT()           rm_init_flags(&sysctllock, "sysctl lock", \
 102                                     RM_SLEEPABLE)
 103 #define SYSCTL_SLEEP(ch, wmesg, timo)                                   \
 104                                 rm_sleep(ch, &sysctllock, 0, wmesg, timo)
 105
 106 static int sysctl_root(SYSCTL_HANDLER_ARGS);
 107
 108 /* Root list */
 109 struct sysctl_oid_list sysctl__children = SLIST_HEAD_INITIALIZER(&sysctl__children);
 110
 111 static int      sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del,
 112                     int recurse);
 113 static int      sysctl_old_kernel(struct sysctl_req *, const void *, size_t);
 114 static int      sysctl_new_kernel(struct sysctl_req *, void *, size_t);
 115
 116 static struct sysctl_oid *
 117 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list)
 118 {
 119         struct sysctl_oid *oidp;
 120
 121         SYSCTL_ASSERT_LOCKED();
 122         SLIST_FOREACH(oidp, list, oid_link) {
 123                 if (strcmp(oidp->oid_name, name) == 0) {
 124                         return (oidp);
 125                 }
 126         }
 127         return (NULL);
 128 }
 129
 130 /*
 131  * Initialization of the MIB tree.
 132  *
 133  * Order by number in each list.
 134  */
 135 void
 136 sysctl_wlock(void)
 137 {
 138
 139         SYSCTL_WLOCK();
 140 }
 141
 142 void
 143 sysctl_wunlock(void)
 144 {
 145
 146         SYSCTL_WUNLOCK();
 147 }
 148
 149 static int
 150 sysctl_root_handler_locked(struct sysctl_oid *oid, void *arg1, intmax_t arg2,
 151     struct sysctl_req *req, struct rm_priotracker *tracker)
 152 {
 153         int error;
 154
 155         if (oid->oid_kind & CTLFLAG_DYN)
 156                 atomic_add_int(&oid->oid_running, 1);
 157
 158         if (tracker != NULL)
 159                 SYSCTL_RUNLOCK(tracker);
 160         else
 161                 SYSCTL_WUNLOCK();
 162
 163         if (!(oid->oid_kind & CTLFLAG_MPSAFE))
 164                 mtx_lock(&Giant);
 165         error = oid->oid_handler(oid, arg1, arg2, req);
 166         if (!(oid->oid_kind & CTLFLAG_MPSAFE))
 167                 mtx_unlock(&Giant);
 168
 169         KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error);
 170
 171         if (tracker != NULL)
 172                 SYSCTL_RLOCK(tracker);
 173         else
 174                 SYSCTL_WLOCK();
 175
 176         if (oid->oid_kind & CTLFLAG_DYN) {
 177                 if (atomic_fetchadd_int(&oid->oid_running, -1) == 1 &&
 178                     (oid->oid_kind & CTLFLAG_DYING) != 0)
 179                         wakeup(&oid->oid_running);
 180         }
 181
 182         return (error);
 183 }
 184
 185 static void
 186 sysctl_load_tunable_by_oid_locked(struct sysctl_oid *oidp)
 187 {
 188         struct sysctl_req req;
 189         struct sysctl_oid *curr;
 190         char *penv = NULL;
 191         char path[64];
 192         ssize_t rem = sizeof(path);
 193         ssize_t len;
 194         uint8_t val_8;
 195         uint16_t val_16;
 196         uint32_t val_32;
 197         int val_int;
 198         long val_long;
 199         int64_t val_64;
 200         quad_t val_quad;
 201         int error;
 202
 203         path[--rem] = 0;
 204
 205         for (curr = oidp; curr != NULL; curr = SYSCTL_PARENT(curr)) {
 206                 len = strlen(curr->oid_name);
 207                 rem -= len;
 208                 if (curr != oidp)
 209                         rem -= 1;
 210                 if (rem < 0) {
 211                         printf("OID path exceeds %d bytes\n", (int)sizeof(path));
 212                         return;
 213                 }
 214                 memcpy(path + rem, curr->oid_name, len);
 215                 if (curr != oidp)
 216                         path[rem + len] = '.';
 217         }
 218
 219         memset(&req, 0, sizeof(req));
 220
 221         req.td = curthread;
 222         req.oldfunc = sysctl_old_kernel;
 223         req.newfunc = sysctl_new_kernel;
 224         req.lock = REQ_UNWIRED;
 225
 226         switch (oidp->oid_kind & CTLTYPE) {
 227         case CTLTYPE_INT:
 228                 if (getenv_int(path + rem, &val_int) == 0)
 229                         return;
 230                 req.newlen = sizeof(val_int);
 231                 req.newptr = &val_int;
 232                 break;
 233         case CTLTYPE_UINT:
 234                 if (getenv_uint(path + rem, (unsigned int *)&val_int) == 0)
 235                         return;
 236                 req.newlen = sizeof(val_int);
 237                 req.newptr = &val_int;
 238                 break;
 239         case CTLTYPE_LONG:
 240                 if (getenv_long(path + rem, &val_long) == 0)
 241                         return;
 242                 req.newlen = sizeof(val_long);
 243                 req.newptr = &val_long;
 244                 break;
 245         case CTLTYPE_ULONG:
 246                 if (getenv_ulong(path + rem, (unsigned long *)&val_long) == 0)
 247                         return;
 248                 req.newlen = sizeof(val_long);
 249                 req.newptr = &val_long;
 250                 break;
 251         case CTLTYPE_S8:
 252                 if (getenv_int(path + rem, &val_int) == 0)
 253                         return;
 254                 val_8 = val_int;
 255                 req.newlen = sizeof(val_8);
 256                 req.newptr = &val_8;
 257                 break;
 258         case CTLTYPE_S16:
 259                 if (getenv_int(path + rem, &val_int) == 0)
 260                         return;
 261                 val_16 = val_int;
 262                 req.newlen = sizeof(val_16);
 263                 req.newptr = &val_16;
 264                 break;
 265         case CTLTYPE_S32:
 266                 if (getenv_long(path + rem, &val_long) == 0)
 267                         return;
 268                 val_32 = val_long;
 269                 req.newlen = sizeof(val_32);
 270                 req.newptr = &val_32;
 271                 break;
 272         case CTLTYPE_S64:
 273                 if (getenv_quad(path + rem, &val_quad) == 0)
 274                         return;
 275                 val_64 = val_quad;
 276                 req.newlen = sizeof(val_64);
 277                 req.newptr = &val_64;
 278                 break;
 279         case CTLTYPE_U8:
 280                 if (getenv_uint(path + rem, (unsigned int *)&val_int) == 0)
 281                         return;
 282                 val_8 = val_int;
 283                 req.newlen = sizeof(val_8);
 284                 req.newptr = &val_8;
 285                 break;
 286         case CTLTYPE_U16:
 287                 if (getenv_uint(path + rem, (unsigned int *)&val_int) == 0)
 288                         return;
 289                 val_16 = val_int;
 290                 req.newlen = sizeof(val_16);
 291                 req.newptr = &val_16;
 292                 break;
 293         case CTLTYPE_U32:
 294                 if (getenv_ulong(path + rem, (unsigned long *)&val_long) == 0)
 295                         return;
 296                 val_32 = val_long;
 297                 req.newlen = sizeof(val_32);
 298                 req.newptr = &val_32;
 299                 break;
 300         case CTLTYPE_U64:
 301                 /* XXX there is no getenv_uquad() */
 302                 if (getenv_quad(path + rem, &val_quad) == 0)
 303                         return;
 304                 val_64 = val_quad;
 305                 req.newlen = sizeof(val_64);
 306                 req.newptr = &val_64;
 307                 break;
 308         case CTLTYPE_STRING:
 309                 penv = kern_getenv(path + rem);
 310                 if (penv == NULL)
 311                         return;
 312                 req.newlen = strlen(penv);
 313                 req.newptr = penv;
 314                 break;
 315         default:
 316                 return;
 317         }
 318         error = sysctl_root_handler_locked(oidp, oidp->oid_arg1,
 319             oidp->oid_arg2, &req, NULL);
 320         if (error != 0)
 321                 printf("Setting sysctl %s failed: %d\n", path + rem, error);
 322         if (penv != NULL)
 323                 freeenv(penv);
 324 }
 325
 326 void
 327 sysctl_register_oid(struct sysctl_oid *oidp)
 328 {
 329         struct sysctl_oid_list *parent = oidp->oid_parent;
 330         struct sysctl_oid *p;
 331         struct sysctl_oid *q;
 332         int oid_number;
 333         int timeout = 2;
 334
 335         /*
 336          * First check if another oid with the same name already
 337          * exists in the parent's list.
 338          */
 339         SYSCTL_ASSERT_WLOCKED();
 340         p = sysctl_find_oidname(oidp->oid_name, parent);
 341         if (p != NULL) {
 342                 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
 343                         p->oid_refcnt++;
 344                         return;
 345                 } else {
 346                         printf("can't re-use a leaf (%s)!\n", p->oid_name);
 347                         return;
 348                 }
 349         }
 350         /* get current OID number */
 351         oid_number = oidp->oid_number;
 352
 353 #if (OID_AUTO >= 0)
 354 #error "OID_AUTO is expected to be a negative value"
 355 #endif
 356         /*
 357          * Any negative OID number qualifies as OID_AUTO. Valid OID
 358          * numbers should always be positive.
 359          *
 360          * NOTE: DO NOT change the starting value here, change it in
 361          * <sys/sysctl.h>, and make sure it is at least 256 to
 362          * accommodate e.g. net.inet.raw as a static sysctl node.
 363          */
 364         if (oid_number < 0) {
 365                 static int newoid;
 366
 367                 /*
 368                  * By decrementing the next OID number we spend less
 369                  * time inserting the OIDs into a sorted list.
 370                  */
 371                 if (--newoid < CTL_AUTO_START)
 372                         newoid = 0x7fffffff;
 373
 374                 oid_number = newoid;
 375         }
 376
 377         /*
 378          * Insert the OID into the parent's list sorted by OID number.
 379          */
 380 retry:
 381         q = NULL;
 382         SLIST_FOREACH(p, parent, oid_link) {
 383                 /* check if the current OID number is in use */
 384                 if (oid_number == p->oid_number) {
 385                         /* get the next valid OID number */
 386                         if (oid_number < CTL_AUTO_START ||
 387                             oid_number == 0x7fffffff) {
 388                                 /* wraparound - restart */
 389                                 oid_number = CTL_AUTO_START;
 390                                 /* don't loop forever */
 391                                 if (!timeout--)
 392                                         panic("sysctl: Out of OID numbers\n");
 393                                 goto retry;
 394                         } else {
 395                                 oid_number++;
 396                         }
 397                 } else if (oid_number < p->oid_number)
 398                         break;
 399                 q = p;
 400         }
 401         /* check for non-auto OID number collision */
 402         if (oidp->oid_number >= 0 && oidp->oid_number < CTL_AUTO_START &&
 403             oid_number >= CTL_AUTO_START) {
 404                 printf("sysctl: OID number(%d) is already in use for '%s'\n",
 405                     oidp->oid_number, oidp->oid_name);
 406         }
 407         /* update the OID number, if any */
 408         oidp->oid_number = oid_number;
 409         if (q != NULL)
 410                 SLIST_INSERT_AFTER(q, oidp, oid_link);
 411         else
 412                 SLIST_INSERT_HEAD(parent, oidp, oid_link);
 413
 414         if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE &&
 415 #ifdef VIMAGE
 416             (oidp->oid_kind & CTLFLAG_VNET) == 0 &&
 417 #endif
 418             (oidp->oid_kind & CTLFLAG_TUN) != 0 &&
 419             (oidp->oid_kind & CTLFLAG_NOFETCH) == 0) {
 420                 /* only fetch value once */
 421                 oidp->oid_kind |= CTLFLAG_NOFETCH;
 422                 /* try to fetch value from kernel environment */
 423                 sysctl_load_tunable_by_oid_locked(oidp);
 424         }
 425 }
 426
 427 void
 428 sysctl_unregister_oid(struct sysctl_oid *oidp)
 429 {
 430         struct sysctl_oid *p;
 431         int error;
 432
 433         SYSCTL_ASSERT_WLOCKED();
 434         error = ENOENT;
 435         if (oidp->oid_number == OID_AUTO) {
 436                 error = EINVAL;
 437         } else {
 438                 SLIST_FOREACH(p, oidp->oid_parent, oid_link) {
 439                         if (p == oidp) {
 440                                 SLIST_REMOVE(oidp->oid_parent, oidp,
 441                                     sysctl_oid, oid_link);
 442                                 error = 0;
 443                                 break;
 444                         }
 445                 }
 446         }
 447
 448         /*
 449          * This can happen when a module fails to register and is
 450          * being unloaded afterwards.  It should not be a panic()
 451          * for normal use.
 452          */
 453         if (error)
 454                 printf("%s: failed to unregister sysctl\n", __func__);
 455 }
 456
 457 /* Initialize a new context to keep track of dynamically added sysctls. */
 458 int
 459 sysctl_ctx_init(struct sysctl_ctx_list *c)
 460 {
 461
 462         if (c == NULL) {
 463                 return (EINVAL);
 464         }
 465
 466         /*
 467          * No locking here, the caller is responsible for not adding
 468          * new nodes to a context until after this function has
 469          * returned.
 470          */
 471         TAILQ_INIT(c);
 472         return (0);
 473 }
 474
 475 /* Free the context, and destroy all dynamic oids registered in this context */
 476 int
 477 sysctl_ctx_free(struct sysctl_ctx_list *clist)
 478 {
 479         struct sysctl_ctx_entry *e, *e1;
 480         int error;
 481
 482         error = 0;
 483         /*
 484          * First perform a "dry run" to check if it's ok to remove oids.
 485          * XXX FIXME
 486          * XXX This algorithm is a hack. But I don't know any
 487          * XXX better solution for now...
 488          */
 489         SYSCTL_WLOCK();
 490         TAILQ_FOREACH(e, clist, link) {
 491                 error = sysctl_remove_oid_locked(e->entry, 0, 0);
 492                 if (error)
 493                         break;
 494         }
 495         /*
 496          * Restore deregistered entries, either from the end,
 497          * or from the place where error occurred.
 498          * e contains the entry that was not unregistered
 499          */
 500         if (error)
 501                 e1 = TAILQ_PREV(e, sysctl_ctx_list, link);
 502         else
 503                 e1 = TAILQ_LAST(clist, sysctl_ctx_list);
 504         while (e1 != NULL) {
 505                 sysctl_register_oid(e1->entry);
 506                 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link);
 507         }
 508         if (error) {
 509                 SYSCTL_WUNLOCK();
 510                 return(EBUSY);
 511         }
 512         /* Now really delete the entries */
 513         e = TAILQ_FIRST(clist);
 514         while (e != NULL) {
 515                 e1 = TAILQ_NEXT(e, link);
 516                 error = sysctl_remove_oid_locked(e->entry, 1, 0);
 517                 if (error)
 518                         panic("sysctl_remove_oid: corrupt tree, entry: %s",
 519                             e->entry->oid_name);
 520                 free(e, M_SYSCTLOID);
 521                 e = e1;
 522         }
 523         SYSCTL_WUNLOCK();
 524         return (error);
 525 }
 526
 527 /* Add an entry to the context */
 528 struct sysctl_ctx_entry *
 529 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
 530 {
 531         struct sysctl_ctx_entry *e;
 532
 533         SYSCTL_ASSERT_WLOCKED();
 534         if (clist == NULL || oidp == NULL)
 535                 return(NULL);
 536         e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK);
 537         e->entry = oidp;
 538         TAILQ_INSERT_HEAD(clist, e, link);
 539         return (e);
 540 }
 541
 542 /* Find an entry in the context */
 543 struct sysctl_ctx_entry *
 544 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
 545 {
 546         struct sysctl_ctx_entry *e;
 547
 548         SYSCTL_ASSERT_WLOCKED();
 549         if (clist == NULL || oidp == NULL)
 550                 return(NULL);
 551         TAILQ_FOREACH(e, clist, link) {
 552                 if(e->entry == oidp)
 553                         return(e);
 554         }
 555         return (e);
 556 }
 557
 558 /*
 559  * Delete an entry from the context.
 560  * NOTE: this function doesn't free oidp! You have to remove it
 561  * with sysctl_remove_oid().
 562  */
 563 int
 564 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
 565 {
 566         struct sysctl_ctx_entry *e;
 567
 568         if (clist == NULL || oidp == NULL)
 569                 return (EINVAL);
 570         SYSCTL_WLOCK();
 571         e = sysctl_ctx_entry_find(clist, oidp);
 572         if (e != NULL) {
 573                 TAILQ_REMOVE(clist, e, link);
 574                 SYSCTL_WUNLOCK();
 575                 free(e, M_SYSCTLOID);
 576                 return (0);
 577         } else {
 578                 SYSCTL_WUNLOCK();
 579                 return (ENOENT);
 580         }
 581 }
 582
 583 /*
 584  * Remove dynamically created sysctl trees.
 585  * oidp - top of the tree to be removed
 586  * del - if 0 - just deregister, otherwise free up entries as well
 587  * recurse - if != 0 traverse the subtree to be deleted
 588  */
 589 int
 590 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse)
 591 {
 592         int error;
 593
 594         SYSCTL_WLOCK();
 595         error = sysctl_remove_oid_locked(oidp, del, recurse);
 596         SYSCTL_WUNLOCK();
 597         return (error);
 598 }
 599
 600 int
 601 sysctl_remove_name(struct sysctl_oid *parent, const char *name,
 602     int del, int recurse)
 603 {
 604         struct sysctl_oid *p, *tmp;
 605         int error;
 606
 607         error = ENOENT;
 608         SYSCTL_WLOCK();
 609         SLIST_FOREACH_SAFE(p, SYSCTL_CHILDREN(parent), oid_link, tmp) {
 610                 if (strcmp(p->oid_name, name) == 0) {
 611                         error = sysctl_remove_oid_locked(p, del, recurse);
 612                         break;
 613                 }
 614         }
 615         SYSCTL_WUNLOCK();
 616
 617         return (error);
 618 }
 619
 620
 621 static int
 622 sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse)
 623 {
 624         struct sysctl_oid *p, *tmp;
 625         int error;
 626
 627         SYSCTL_ASSERT_WLOCKED();
 628         if (oidp == NULL)
 629                 return(EINVAL);
 630         if ((oidp->oid_kind & CTLFLAG_DYN) == 0) {
 631                 printf("can't remove non-dynamic nodes!\n");
 632                 return (EINVAL);
 633         }
 634         /*
 635          * WARNING: normal method to do this should be through
 636          * sysctl_ctx_free(). Use recursing as the last resort
 637          * method to purge your sysctl tree of leftovers...
 638          * However, if some other code still references these nodes,
 639          * it will panic.
 640          */
 641         if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
 642                 if (oidp->oid_refcnt == 1) {
 643                         SLIST_FOREACH_SAFE(p,
 644                             SYSCTL_CHILDREN(oidp), oid_link, tmp) {
 645                                 if (!recurse) {
 646                                         printf("Warning: failed attempt to "
 647                                             "remove oid %s with child %s\n",
 648                                             oidp->oid_name, p->oid_name);
 649                                         return (ENOTEMPTY);
 650                                 }
 651                                 error = sysctl_remove_oid_locked(p, del,
 652                                     recurse);
 653                                 if (error)
 654                                         return (error);
 655                         }
 656                 }
 657         }
 658         if (oidp->oid_refcnt > 1 ) {
 659                 oidp->oid_refcnt--;
 660         } else {
 661                 if (oidp->oid_refcnt == 0) {
 662                         printf("Warning: bad oid_refcnt=%u (%s)!\n",
 663                                 oidp->oid_refcnt, oidp->oid_name);
 664                         return (EINVAL);
 665                 }
 666                 sysctl_unregister_oid(oidp);
 667                 if (del) {
 668                         /*
 669                          * Wait for all threads running the handler to drain.
 670                          * This preserves the previous behavior when the
 671                          * sysctl lock was held across a handler invocation,
 672                          * and is necessary for module unload correctness.
 673                          */
 674                         while (oidp->oid_running > 0) {
 675                                 oidp->oid_kind |= CTLFLAG_DYING;
 676                                 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0);
 677                         }
 678                         if (oidp->oid_descr)
 679                                 free(__DECONST(char *, oidp->oid_descr),
 680                                     M_SYSCTLOID);
 681                         free(__DECONST(char *, oidp->oid_name), M_SYSCTLOID);
 682                         free(oidp, M_SYSCTLOID);
 683                 }
 684         }
 685         return (0);
 686 }
 687 /*
 688  * Create new sysctls at run time.
 689  * clist may point to a valid context initialized with sysctl_ctx_init().
 690  */
 691 struct sysctl_oid *
 692 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent,
 693         int number, const char *name, int kind, void *arg1, intmax_t arg2,
 694         int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr)
 695 {
 696         struct sysctl_oid *oidp;
 697
 698         /* You have to hook up somewhere.. */
 699         if (parent == NULL)
 700                 return(NULL);
 701         /* Check if the node already exists, otherwise create it */
 702         SYSCTL_WLOCK();
 703         oidp = sysctl_find_oidname(name, parent);
 704         if (oidp != NULL) {
 705                 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
 706                         oidp->oid_refcnt++;
 707                         /* Update the context */
 708                         if (clist != NULL)
 709                                 sysctl_ctx_entry_add(clist, oidp);
 710                         SYSCTL_WUNLOCK();
 711                         return (oidp);
 712                 } else {
 713                         SYSCTL_WUNLOCK();
 714                         printf("can't re-use a leaf (%s)!\n", name);
 715                         return (NULL);
 716                 }
 717         }
 718         oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO);
 719         oidp->oid_parent = parent;
 720         SLIST_INIT(&oidp->oid_children);
 721         oidp->oid_number = number;
 722         oidp->oid_refcnt = 1;
 723         oidp->oid_name = strdup(name, M_SYSCTLOID);
 724         oidp->oid_handler = handler;
 725         oidp->oid_kind = CTLFLAG_DYN | kind;
 726         oidp->oid_arg1 = arg1;
 727         oidp->oid_arg2 = arg2;
 728         oidp->oid_fmt = fmt;
 729         if (descr != NULL)
 730                 oidp->oid_descr = strdup(descr, M_SYSCTLOID);
 731         /* Update the context, if used */
 732         if (clist != NULL)
 733                 sysctl_ctx_entry_add(clist, oidp);
 734         /* Register this oid */
 735         sysctl_register_oid(oidp);
 736         SYSCTL_WUNLOCK();
 737         return (oidp);
 738 }
 739
 740 /*
 741  * Rename an existing oid.
 742  */
 743 void
 744 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name)
 745 {
 746         char *newname;
 747         char *oldname;
 748
 749         newname = strdup(name, M_SYSCTLOID);
 750         SYSCTL_WLOCK();
 751         oldname = __DECONST(char *, oidp->oid_name);
 752         oidp->oid_name = newname;
 753         SYSCTL_WUNLOCK();
 754         free(oldname, M_SYSCTLOID);
 755 }
 756
 757 /*
 758  * Reparent an existing oid.
 759  */
 760 int
 761 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent)
 762 {
 763         struct sysctl_oid *oidp;
 764
 765         SYSCTL_WLOCK();
 766         if (oid->oid_parent == parent) {
 767                 SYSCTL_WUNLOCK();
 768                 return (0);
 769         }
 770         oidp = sysctl_find_oidname(oid->oid_name, parent);
 771         if (oidp != NULL) {
 772                 SYSCTL_WUNLOCK();
 773                 return (EEXIST);
 774         }
 775         sysctl_unregister_oid(oid);
 776         oid->oid_parent = parent;
 777         oid->oid_number = OID_AUTO;
 778         sysctl_register_oid(oid);
 779         SYSCTL_WUNLOCK();
 780         return (0);
 781 }
 782
 783 /*
 784  * Register the kernel's oids on startup.
 785  */
 786 SET_DECLARE(sysctl_set, struct sysctl_oid);
 787
 788 static void
 789 sysctl_register_all(void *arg)
 790 {
 791         struct sysctl_oid **oidp;
 792
 793         sx_init(&sysctlmemlock, "sysctl mem");
 794         SYSCTL_INIT();
 795         SYSCTL_WLOCK();
 796         SET_FOREACH(oidp, sysctl_set)
 797                 sysctl_register_oid(*oidp);
 798         SYSCTL_WUNLOCK();
 799 }
 800 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_FIRST, sysctl_register_all, 0);
 801
 802 /*
 803  * "Staff-functions"
 804  *
 805  * These functions implement a presently undocumented interface
 806  * used by the sysctl program to walk the tree, and get the type
 807  * so it can print the value.
 808  * This interface is under work and consideration, and should probably
 809  * be killed with a big axe by the first person who can find the time.
 810  * (be aware though, that the proper interface isn't as obvious as it
 811  * may seem, there are various conflicting requirements.
 812  *
 813  * {0,0}        printf the entire MIB-tree.
 814  * {0,1,...}    return the name of the "..." OID.
 815  * {0,2,...}    return the next OID.
 816  * {0,3}        return the OID of the name in "new"
 817  * {0,4,...}    return the kind & format info for the "..." OID.
 818  * {0,5,...}    return the description the "..." OID.
 819  */
 820
 821 #ifdef SYSCTL_DEBUG
 822 static void
 823 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i)
 824 {
 825         int k;
 826         struct sysctl_oid *oidp;
 827
 828         SYSCTL_ASSERT_LOCKED();
 829         SLIST_FOREACH(oidp, l, oid_link) {
 830
 831                 for (k=0; k<i; k++)
 832                         printf(" ");
 833
 834                 printf("%d %s ", oidp->oid_number, oidp->oid_name);
 835
 836                 printf("%c%c",
 837                         oidp->oid_kind & CTLFLAG_RD ? 'R':' ',
 838                         oidp->oid_kind & CTLFLAG_WR ? 'W':' ');
 839
 840                 if (oidp->oid_handler)
 841                         printf(" *Handler");
 842
 843                 switch (oidp->oid_kind & CTLTYPE) {
 844                         case CTLTYPE_NODE:
 845                                 printf(" Node\n");
 846                                 if (!oidp->oid_handler) {
 847                                         sysctl_sysctl_debug_dump_node(
 848                                             SYSCTL_CHILDREN(oidp), i + 2);
 849                                 }
 850                                 break;
 851                         case CTLTYPE_INT:    printf(" Int\n"); break;
 852                         case CTLTYPE_UINT:   printf(" u_int\n"); break;
 853                         case CTLTYPE_LONG:   printf(" Long\n"); break;
 854                         case CTLTYPE_ULONG:  printf(" u_long\n"); break;
 855                         case CTLTYPE_STRING: printf(" String\n"); break;
 856                         case CTLTYPE_S8:     printf(" int8_t\n"); break;
 857                         case CTLTYPE_S16:    printf(" int16_t\n"); break;
 858                         case CTLTYPE_S32:    printf(" int32_t\n"); break;
 859                         case CTLTYPE_S64:    printf(" int64_t\n"); break;
 860                         case CTLTYPE_U8:     printf(" uint8_t\n"); break;
 861                         case CTLTYPE_U16:    printf(" uint16_t\n"); break;
 862                         case CTLTYPE_U32:    printf(" uint32_t\n"); break;
 863                         case CTLTYPE_U64:    printf(" uint64_t\n"); break;
 864                         case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break;
 865                         default:             printf("\n");
 866                 }
 867
 868         }
 869 }
 870
 871 static int
 872 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS)
 873 {
 874         struct rm_priotracker tracker;
 875         int error;
 876
 877         error = priv_check(req->td, PRIV_SYSCTL_DEBUG);
 878         if (error)
 879                 return (error);
 880         SYSCTL_RLOCK(&tracker);
 881         sysctl_sysctl_debug_dump_node(&sysctl__children, 0);
 882         SYSCTL_RUNLOCK(&tracker);
 883         return (ENOENT);
 884 }
 885
 886 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE,
 887         0, 0, sysctl_sysctl_debug, "-", "");
 888 #endif
 889
 890 static int
 891 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS)
 892 {
 893         int *name = (int *) arg1;
 894         u_int namelen = arg2;
 895         int error = 0;
 896         struct sysctl_oid *oid;
 897         struct sysctl_oid_list *lsp = &sysctl__children, *lsp2;
 898         struct rm_priotracker tracker;
 899         char buf[10];
 900
 901         SYSCTL_RLOCK(&tracker);
 902         while (namelen) {
 903                 if (!lsp) {
 904                         snprintf(buf,sizeof(buf),"%d",*name);
 905                         if (req->oldidx)
 906                                 error = SYSCTL_OUT(req, ".", 1);
 907                         if (!error)
 908                                 error = SYSCTL_OUT(req, buf, strlen(buf));
 909                         if (error)
 910                                 goto out;
 911                         namelen--;
 912                         name++;
 913                         continue;
 914                 }
 915                 lsp2 = NULL;
 916                 SLIST_FOREACH(oid, lsp, oid_link) {
 917                         if (oid->oid_number != *name)
 918                                 continue;
 919
 920                         if (req->oldidx)
 921                                 error = SYSCTL_OUT(req, ".", 1);
 922                         if (!error)
 923                                 error = SYSCTL_OUT(req, oid->oid_name,
 924                                         strlen(oid->oid_name));
 925                         if (error)
 926                                 goto out;
 927
 928                         namelen--;
 929                         name++;
 930
 931                         if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE)
 932                                 break;
 933
 934                         if (oid->oid_handler)
 935                                 break;
 936
 937                         lsp2 = SYSCTL_CHILDREN(oid);
 938                         break;
 939                 }
 940                 lsp = lsp2;
 941         }
 942         error = SYSCTL_OUT(req, "", 1);
 943  out:
 944         SYSCTL_RUNLOCK(&tracker);
 945         return (error);
 946 }
 947
 948 /*
 949  * XXXRW/JA: Shouldn't return name data for nodes that we don't permit in
 950  * capability mode.
 951  */
 952 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD,
 953     sysctl_sysctl_name, "");
 954
 955 static int
 956 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen,
 957         int *next, int *len, int level, struct sysctl_oid **oidpp)
 958 {
 959         struct sysctl_oid *oidp;
 960
 961         SYSCTL_ASSERT_LOCKED();
 962         *len = level;
 963         SLIST_FOREACH(oidp, lsp, oid_link) {
 964                 *next = oidp->oid_number;
 965                 *oidpp = oidp;
 966
 967                 if (oidp->oid_kind & CTLFLAG_SKIP)
 968                         continue;
 969
 970                 if (!namelen) {
 971                         if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
 972                                 return (0);
 973                         if (oidp->oid_handler)
 974                                 /* We really should call the handler here...*/
 975                                 return (0);
 976                         lsp = SYSCTL_CHILDREN(oidp);
 977                         if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1,
 978                                 len, level+1, oidpp))
 979                                 return (0);
 980                         goto emptynode;
 981                 }
 982
 983                 if (oidp->oid_number < *name)
 984                         continue;
 985
 986                 if (oidp->oid_number > *name) {
 987                         if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
 988                                 return (0);
 989                         if (oidp->oid_handler)
 990                                 return (0);
 991                         lsp = SYSCTL_CHILDREN(oidp);
 992                         if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1,
 993                                 next+1, len, level+1, oidpp))
 994                                 return (0);
 995                         goto next;
 996                 }
 997                 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
 998                         continue;
 999
1000                 if (oidp->oid_handler)
1001                         continue;
1002
1003                 lsp = SYSCTL_CHILDREN(oidp);
1004                 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1,
1005                         len, level+1, oidpp))
1006                         return (0);
1007         next:
1008                 namelen = 1;
1009         emptynode:
1010                 *len = level;
1011         }
1012         return (1);
1013 }
1014
1015 static int
1016 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS)
1017 {
1018         int *name = (int *) arg1;
1019         u_int namelen = arg2;
1020         int i, j, error;
1021         struct sysctl_oid *oid;
1022         struct sysctl_oid_list *lsp = &sysctl__children;
1023         struct rm_priotracker tracker;
1024         int newoid[CTL_MAXNAME];
1025
1026         SYSCTL_RLOCK(&tracker);
1027         i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid);
1028         SYSCTL_RUNLOCK(&tracker);
1029         if (i)
1030                 return (ENOENT);
1031         error = SYSCTL_OUT(req, newoid, j * sizeof (int));
1032         return (error);
1033 }
1034
1035 /*
1036  * XXXRW/JA: Shouldn't return next data for nodes that we don't permit in
1037  * capability mode.
1038  */
1039 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD,
1040     sysctl_sysctl_next, "");
1041
1042 static int
1043 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp)
1044 {
1045         struct sysctl_oid *oidp;
1046         struct sysctl_oid_list *lsp = &sysctl__children;
1047         char *p;
1048
1049         SYSCTL_ASSERT_LOCKED();
1050
1051         for (*len = 0; *len < CTL_MAXNAME;) {
1052                 p = strsep(&name, ".");
1053
1054                 oidp = SLIST_FIRST(lsp);
1055                 for (;; oidp = SLIST_NEXT(oidp, oid_link)) {
1056                         if (oidp == NULL)
1057                                 return (ENOENT);
1058                         if (strcmp(p, oidp->oid_name) == 0)
1059                                 break;
1060                 }
1061                 *oid++ = oidp->oid_number;
1062                 (*len)++;
1063
1064                 if (name == NULL || *name == '\0') {
1065                         if (oidpp)
1066                                 *oidpp = oidp;
1067                         return (0);
1068                 }
1069
1070                 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
1071                         break;
1072
1073                 if (oidp->oid_handler)
1074                         break;
1075
1076                 lsp = SYSCTL_CHILDREN(oidp);
1077         }
1078         return (ENOENT);
1079 }
1080
1081 static int
1082 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
1083 {
1084         char *p;
1085         int error, oid[CTL_MAXNAME], len = 0;
1086         struct sysctl_oid *op = NULL;
1087         struct rm_priotracker tracker;
1088
1089         if (!req->newlen)
1090                 return (ENOENT);
1091         if (req->newlen >= MAXPATHLEN)  /* XXX arbitrary, undocumented */
1092                 return (ENAMETOOLONG);
1093
1094         p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK);
1095
1096         error = SYSCTL_IN(req, p, req->newlen);
1097         if (error) {
1098                 free(p, M_SYSCTL);
1099                 return (error);
1100         }
1101
1102         p [req->newlen] = '\0';
1103
1104         SYSCTL_RLOCK(&tracker);
1105         error = name2oid(p, oid, &len, &op);
1106         SYSCTL_RUNLOCK(&tracker);
1107
1108         free(p, M_SYSCTL);
1109
1110         if (error)
1111                 return (error);
1112
1113         error = SYSCTL_OUT(req, oid, len * sizeof *oid);
1114         return (error);
1115 }
1116
1117 /*
1118  * XXXRW/JA: Shouldn't return name2oid data for nodes that we don't permit in
1119  * capability mode.
1120  */
1121 SYSCTL_PROC(_sysctl, 3, name2oid,
1122     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE
1123     | CTLFLAG_CAPRW, 0, 0, sysctl_sysctl_name2oid, "I", "");
1124
1125 static int
1126 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
1127 {
1128         struct sysctl_oid *oid;
1129         struct rm_priotracker tracker;
1130         int error;
1131
1132         SYSCTL_RLOCK(&tracker);
1133         error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
1134         if (error)
1135                 goto out;
1136
1137         if (oid->oid_fmt == NULL) {
1138                 error = ENOENT;
1139                 goto out;
1140         }
1141         error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind));
1142         if (error)
1143                 goto out;
1144         error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1);
1145  out:
1146         SYSCTL_RUNLOCK(&tracker);
1147         return (error);
1148 }
1149
1150
1151 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD,
1152     sysctl_sysctl_oidfmt, "");
1153
1154 static int
1155 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS)
1156 {
1157         struct sysctl_oid *oid;
1158         struct rm_priotracker tracker;
1159         int error;
1160
1161         SYSCTL_RLOCK(&tracker);
1162         error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
1163         if (error)
1164                 goto out;
1165
1166         if (oid->oid_descr == NULL) {
1167                 error = ENOENT;
1168                 goto out;
1169         }
1170         error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1);
1171  out:
1172         SYSCTL_RUNLOCK(&tracker);
1173         return (error);
1174 }
1175
1176 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD,
1177     sysctl_sysctl_oiddescr, "");
1178
1179 /*
1180  * Default "handler" functions.
1181  */
1182
1183 /*
1184  * Handle a bool.
1185  * Two cases:
1186  *     a variable:  point arg1 at it.
1187  *     a constant:  pass it in arg2.
1188  */
1189
1190 int
1191 sysctl_handle_bool(SYSCTL_HANDLER_ARGS)
1192 {
1193         uint8_t temp;
1194         int error;
1195
1196         /*
1197          * Attempt to get a coherent snapshot by making a copy of the data.
1198          */
1199         if (arg1)
1200                 temp = *(bool *)arg1 ? 1 : 0;
1201         else
1202                 temp = arg2 ? 1 : 0;
1203
1204         error = SYSCTL_OUT(req, &temp, sizeof(temp));
1205         if (error || !req->newptr)
1206                 return (error);
1207
1208         if (!arg1)
1209                 error = EPERM;
1210         else {
1211                 error = SYSCTL_IN(req, &temp, sizeof(temp));
1212                 if (!error)
1213                         *(bool *)arg1 = temp ? 1 : 0;
1214         }
1215         return (error);
1216 }
1217
1218 /*
1219  * Handle an int8_t, signed or unsigned.
1220  * Two cases:
1221  *     a variable:  point arg1 at it.
1222  *     a constant:  pass it in arg2.
1223  */
1224
1225 int
1226 sysctl_handle_8(SYSCTL_HANDLER_ARGS)
1227 {
1228         int8_t tmpout;
1229         int error = 0;
1230
1231         /*
1232          * Attempt to get a coherent snapshot by making a copy of the data.
1233          */
1234         if (arg1)
1235                 tmpout = *(int8_t *)arg1;
1236         else
1237                 tmpout = arg2;
1238         error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout));
1239
1240         if (error || !req->newptr)
1241                 return (error);
1242
1243         if (!arg1)
1244                 error = EPERM;
1245         else
1246                 error = SYSCTL_IN(req, arg1, sizeof(tmpout));
1247         return (error);
1248 }
1249
1250 /*
1251  * Handle an int16_t, signed or unsigned.
1252  * Two cases:
1253  *     a variable:  point arg1 at it.
1254  *     a constant:  pass it in arg2.
1255  */
1256
1257 int
1258 sysctl_handle_16(SYSCTL_HANDLER_ARGS)
1259 {
1260         int16_t tmpout;
1261         int error = 0;
1262
1263         /*
1264          * Attempt to get a coherent snapshot by making a copy of the data.
1265          */
1266         if (arg1)
1267                 tmpout = *(int16_t *)arg1;
1268         else
1269                 tmpout = arg2;
1270         error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout));
1271
1272         if (error || !req->newptr)
1273                 return (error);
1274
1275         if (!arg1)
1276                 error = EPERM;
1277         else
1278                 error = SYSCTL_IN(req, arg1, sizeof(tmpout));
1279         return (error);
1280 }
1281
1282 /*
1283  * Handle an int32_t, signed or unsigned.
1284  * Two cases:
1285  *     a variable:  point arg1 at it.
1286  *     a constant:  pass it in arg2.
1287  */
1288
1289 int
1290 sysctl_handle_32(SYSCTL_HANDLER_ARGS)
1291 {
1292         int32_t tmpout;
1293         int error = 0;
1294
1295         /*
1296          * Attempt to get a coherent snapshot by making a copy of the data.
1297          */
1298         if (arg1)
1299                 tmpout = *(int32_t *)arg1;
1300         else
1301                 tmpout = arg2;
1302         error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout));
1303
1304         if (error || !req->newptr)
1305                 return (error);
1306
1307         if (!arg1)
1308                 error = EPERM;
1309         else
1310                 error = SYSCTL_IN(req, arg1, sizeof(tmpout));
1311         return (error);
1312 }
1313
1314 /*
1315  * Handle an int, signed or unsigned.
1316  * Two cases:
1317  *     a variable:  point arg1 at it.
1318  *     a constant:  pass it in arg2.
1319  */
1320
1321 int
1322 sysctl_handle_int(SYSCTL_HANDLER_ARGS)
1323 {
1324         int tmpout, error = 0;
1325
1326         /*
1327          * Attempt to get a coherent snapshot by making a copy of the data.
1328          */
1329         if (arg1)
1330                 tmpout = *(int *)arg1;
1331         else
1332                 tmpout = arg2;
1333         error = SYSCTL_OUT(req, &tmpout, sizeof(int));
1334
1335         if (error || !req->newptr)
1336                 return (error);
1337
1338         if (!arg1)
1339                 error = EPERM;
1340         else
1341                 error = SYSCTL_IN(req, arg1, sizeof(int));
1342         return (error);
1343 }
1344
1345 /*
1346  * Based on on sysctl_handle_int() convert milliseconds into ticks.
1347  * Note: this is used by TCP.
1348  */
1349
1350 int
1351 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS)
1352 {
1353         int error, s, tt;
1354
1355         tt = *(int *)arg1;
1356         s = (int)((int64_t)tt * 1000 / hz);
1357
1358         error = sysctl_handle_int(oidp, &s, 0, req);
1359         if (error || !req->newptr)
1360                 return (error);
1361
1362         tt = (int)((int64_t)s * hz / 1000);
1363         if (tt < 1)
1364                 return (EINVAL);
1365
1366         *(int *)arg1 = tt;
1367         return (0);
1368 }
1369
1370
1371 /*
1372  * Handle a long, signed or unsigned.
1373  * Two cases:
1374  *     a variable:  point arg1 at it.
1375  *     a constant:  pass it in arg2.
1376  */
1377
1378 int
1379 sysctl_handle_long(SYSCTL_HANDLER_ARGS)
1380 {
1381         int error = 0;
1382         long tmplong;
1383 #ifdef SCTL_MASK32
1384         int tmpint;
1385 #endif
1386
1387         /*
1388          * Attempt to get a coherent snapshot by making a copy of the data.
1389          */
1390         if (arg1)
1391                 tmplong = *(long *)arg1;
1392         else
1393                 tmplong = arg2;
1394 #ifdef SCTL_MASK32
1395         if (req->flags & SCTL_MASK32) {
1396                 tmpint = tmplong;
1397                 error = SYSCTL_OUT(req, &tmpint, sizeof(int));
1398         } else
1399 #endif
1400                 error = SYSCTL_OUT(req, &tmplong, sizeof(long));
1401
1402         if (error || !req->newptr)
1403                 return (error);
1404
1405         if (!arg1)
1406                 error = EPERM;
1407 #ifdef SCTL_MASK32
1408         else if (req->flags & SCTL_MASK32) {
1409                 error = SYSCTL_IN(req, &tmpint, sizeof(int));
1410                 *(long *)arg1 = (long)tmpint;
1411         }
1412 #endif
1413         else
1414                 error = SYSCTL_IN(req, arg1, sizeof(long));
1415         return (error);
1416 }
1417
1418 /*
1419  * Handle a 64 bit int, signed or unsigned.
1420  * Two cases:
1421  *     a variable:  point arg1 at it.
1422  *     a constant:  pass it in arg2.
1423  */
1424 int
1425 sysctl_handle_64(SYSCTL_HANDLER_ARGS)
1426 {
1427         int error = 0;
1428         uint64_t tmpout;
1429
1430         /*
1431          * Attempt to get a coherent snapshot by making a copy of the data.
1432          */
1433         if (arg1)
1434                 tmpout = *(uint64_t *)arg1;
1435         else
1436                 tmpout = arg2;
1437         error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t));
1438
1439         if (error || !req->newptr)
1440                 return (error);
1441
1442         if (!arg1)
1443                 error = EPERM;
1444         else
1445                 error = SYSCTL_IN(req, arg1, sizeof(uint64_t));
1446         return (error);
1447 }
1448
1449 /*
1450  * Handle our generic '\0' terminated 'C' string.
1451  * Two cases:
1452  *      a variable string:  point arg1 at it, arg2 is max length.
1453  *      a constant string:  point arg1 at it, arg2 is zero.
1454  */
1455
1456 int
1457 sysctl_handle_string(SYSCTL_HANDLER_ARGS)
1458 {
1459         size_t outlen;
1460         int error = 0, ro_string = 0;
1461
1462         /*
1463          * A zero-length buffer indicates a fixed size read-only
1464          * string:
1465          */
1466         if (arg2 == 0) {
1467                 arg2 = strlen((char *)arg1) + 1;
1468                 ro_string = 1;
1469         }
1470
1471         if (req->oldptr != NULL) {
1472                 char *tmparg;
1473
1474                 if (ro_string) {
1475                         tmparg = arg1;
1476                 } else {
1477                         /* try to make a coherent snapshot of the string */
1478                         tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK);
1479                         memcpy(tmparg, arg1, arg2);
1480                 }
1481
1482                 outlen = strnlen(tmparg, arg2 - 1) + 1;
1483                 error = SYSCTL_OUT(req, tmparg, outlen);
1484
1485                 if (!ro_string)
1486                         free(tmparg, M_SYSCTLTMP);
1487         } else {
1488                 outlen = strnlen((char *)arg1, arg2 - 1) + 1;
1489                 error = SYSCTL_OUT(req, NULL, outlen);
1490         }
1491         if (error || !req->newptr)
1492                 return (error);
1493
1494         if ((req->newlen - req->newidx) >= arg2) {
1495                 error = EINVAL;
1496         } else {
1497                 arg2 = (req->newlen - req->newidx);
1498                 error = SYSCTL_IN(req, arg1, arg2);
1499                 ((char *)arg1)[arg2] = '\0';
1500         }
1501         return (error);
1502 }
1503
1504 /*
1505  * Handle any kind of opaque data.
1506  * arg1 points to it, arg2 is the size.
1507  */
1508
1509 int
1510 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
1511 {
1512         int error, tries;
1513         u_int generation;
1514         struct sysctl_req req2;
1515
1516         /*
1517          * Attempt to get a coherent snapshot, by using the thread
1518          * pre-emption counter updated from within mi_switch() to
1519          * determine if we were pre-empted during a bcopy() or
1520          * copyout(). Make 3 attempts at doing this before giving up.
1521          * If we encounter an error, stop immediately.
1522          */
1523         tries = 0;
1524         req2 = *req;
1525 retry:
1526         generation = curthread->td_generation;
1527         error = SYSCTL_OUT(req, arg1, arg2);
1528         if (error)
1529                 return (error);
1530         tries++;
1531         if (generation != curthread->td_generation && tries < 3) {
1532                 *req = req2;
1533                 goto retry;
1534         }
1535
1536         error = SYSCTL_IN(req, arg1, arg2);
1537
1538         return (error);
1539 }
1540
1541 /*
1542  * Transfer functions to/from kernel space.
1543  * XXX: rather untested at this point
1544  */
1545 static int
1546 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l)
1547 {
1548         size_t i = 0;
1549
1550         if (req->oldptr) {
1551                 i = l;
1552                 if (req->oldlen <= req->oldidx)
1553                         i = 0;
1554                 else
1555                         if (i > req->oldlen - req->oldidx)
1556                                 i = req->oldlen - req->oldidx;
1557                 if (i > 0)
1558                         bcopy(p, (char *)req->oldptr + req->oldidx, i);
1559         }
1560         req->oldidx += l;
1561         if (req->oldptr && i != l)
1562                 return (ENOMEM);
1563         return (0);
1564 }
1565
1566 static int
1567 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l)
1568 {
1569         if (!req->newptr)
1570                 return (0);
1571         if (req->newlen - req->newidx < l)
1572                 return (EINVAL);
1573         bcopy((char *)req->newptr + req->newidx, p, l);
1574         req->newidx += l;
1575         return (0);
1576 }
1577
1578 int
1579 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old,
1580     size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags)
1581 {
1582         int error = 0;
1583         struct sysctl_req req;
1584
1585         bzero(&req, sizeof req);
1586
1587         req.td = td;
1588         req.flags = flags;
1589
1590         if (oldlenp) {
1591                 req.oldlen = *oldlenp;
1592         }
1593         req.validlen = req.oldlen;
1594
1595         if (old) {
1596                 req.oldptr= old;
1597         }
1598
1599         if (new != NULL) {
1600                 req.newlen = newlen;
1601                 req.newptr = new;
1602         }
1603
1604         req.oldfunc = sysctl_old_kernel;
1605         req.newfunc = sysctl_new_kernel;
1606         req.lock = REQ_UNWIRED;
1607
1608         error = sysctl_root(0, name, namelen, &req);
1609
1610         if (req.lock == REQ_WIRED && req.validlen > 0)
1611                 vsunlock(req.oldptr, req.validlen);
1612
1613         if (error && error != ENOMEM)
1614                 return (error);
1615
1616         if (retval) {
1617                 if (req.oldptr && req.oldidx > req.validlen)
1618                         *retval = req.validlen;
1619                 else
1620                         *retval = req.oldidx;
1621         }
1622         return (error);
1623 }
1624
1625 int
1626 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp,
1627     void *new, size_t newlen, size_t *retval, int flags)
1628 {
1629         int oid[CTL_MAXNAME];
1630         size_t oidlen, plen;
1631         int error;
1632
1633         oid[0] = 0;             /* sysctl internal magic */
1634         oid[1] = 3;             /* name2oid */
1635         oidlen = sizeof(oid);
1636
1637         error = kernel_sysctl(td, oid, 2, oid, &oidlen,
1638             (void *)name, strlen(name), &plen, flags);
1639         if (error)
1640                 return (error);
1641
1642         error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp,
1643             new, newlen, retval, flags);
1644         return (error);
1645 }
1646
1647 /*
1648  * Transfer function to/from user space.
1649  */
1650 static int
1651 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l)
1652 {
1653         size_t i, len, origidx;
1654         int error;
1655
1656         origidx = req->oldidx;
1657         req->oldidx += l;
1658         if (req->oldptr == NULL)
1659                 return (0);
1660         /*
1661          * If we have not wired the user supplied buffer and we are currently
1662          * holding locks, drop a witness warning, as it's possible that
1663          * write operations to the user page can sleep.
1664          */
1665         if (req->lock != REQ_WIRED)
1666                 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1667                     "sysctl_old_user()");
1668         i = l;
1669         len = req->validlen;
1670         if (len <= origidx)
1671                 i = 0;
1672         else {
1673                 if (i > len - origidx)
1674                         i = len - origidx;
1675                 if (req->lock == REQ_WIRED) {
1676                         error = copyout_nofault(p, (char *)req->oldptr +
1677                             origidx, i);
1678                 } else
1679                         error = copyout(p, (char *)req->oldptr + origidx, i);
1680                 if (error != 0)
1681                         return (error);
1682         }
1683         if (i < l)
1684                 return (ENOMEM);
1685         return (0);
1686 }
1687
1688 static int
1689 sysctl_new_user(struct sysctl_req *req, void *p, size_t l)
1690 {
1691         int error;
1692
1693         if (!req->newptr)
1694                 return (0);
1695         if (req->newlen - req->newidx < l)
1696                 return (EINVAL);
1697         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1698             "sysctl_new_user()");
1699         error = copyin((char *)req->newptr + req->newidx, p, l);
1700         req->newidx += l;
1701         return (error);
1702 }
1703
1704 /*
1705  * Wire the user space destination buffer.  If set to a value greater than
1706  * zero, the len parameter limits the maximum amount of wired memory.
1707  */
1708 int
1709 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len)
1710 {
1711         int ret;
1712         size_t wiredlen;
1713
1714         wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen;
1715         ret = 0;
1716         if (req->lock != REQ_WIRED && req->oldptr &&
1717             req->oldfunc == sysctl_old_user) {
1718                 if (wiredlen != 0) {
1719                         ret = vslock(req->oldptr, wiredlen);
1720                         if (ret != 0) {
1721                                 if (ret != ENOMEM)
1722                                         return (ret);
1723                                 wiredlen = 0;
1724                         }
1725                 }
1726                 req->lock = REQ_WIRED;
1727                 req->validlen = wiredlen;
1728         }
1729         return (0);
1730 }
1731
1732 int
1733 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid,
1734     int *nindx, struct sysctl_req *req)
1735 {
1736         struct sysctl_oid_list *lsp;
1737         struct sysctl_oid *oid;
1738         int indx;
1739
1740         SYSCTL_ASSERT_LOCKED();
1741         lsp = &sysctl__children;
1742         indx = 0;
1743         while (indx < CTL_MAXNAME) {
1744                 SLIST_FOREACH(oid, lsp, oid_link) {
1745                         if (oid->oid_number == name[indx])
1746                                 break;
1747                 }
1748                 if (oid == NULL)
1749                         return (ENOENT);
1750
1751                 indx++;
1752                 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1753                         if (oid->oid_handler != NULL || indx == namelen) {
1754                                 *noid = oid;
1755                                 if (nindx != NULL)
1756                                         *nindx = indx;
1757                                 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
1758                                     ("%s found DYING node %p", __func__, oid));
1759                                 return (0);
1760                         }
1761                         lsp = SYSCTL_CHILDREN(oid);
1762                 } else if (indx == namelen) {
1763                         *noid = oid;
1764                         if (nindx != NULL)
1765                                 *nindx = indx;
1766                         KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
1767                             ("%s found DYING node %p", __func__, oid));
1768                         return (0);
1769                 } else {
1770                         return (ENOTDIR);
1771                 }
1772         }
1773         return (ENOENT);
1774 }
1775
1776 /*
1777  * Traverse our tree, and find the right node, execute whatever it points
1778  * to, and return the resulting error code.
1779  */
1780
1781 static int
1782 sysctl_root(SYSCTL_HANDLER_ARGS)
1783 {
1784         struct sysctl_oid *oid;
1785         struct rm_priotracker tracker;
1786         int error, indx, lvl;
1787
1788         SYSCTL_RLOCK(&tracker);
1789
1790         error = sysctl_find_oid(arg1, arg2, &oid, &indx, req);
1791         if (error)
1792                 goto out;
1793
1794         if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1795                 /*
1796                  * You can't call a sysctl when it's a node, but has
1797                  * no handler.  Inform the user that it's a node.
1798                  * The indx may or may not be the same as namelen.
1799                  */
1800                 if (oid->oid_handler == NULL) {
1801                         error = EISDIR;
1802                         goto out;
1803                 }
1804         }
1805
1806         /* Is this sysctl writable? */
1807         if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) {
1808                 error = EPERM;
1809                 goto out;
1810         }
1811
1812         KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL"));
1813
1814 #ifdef CAPABILITY_MODE
1815         /*
1816          * If the process is in capability mode, then don't permit reading or
1817          * writing unless specifically granted for the node.
1818          */
1819         if (IN_CAPABILITY_MODE(req->td)) {
1820                 if ((req->oldptr && !(oid->oid_kind & CTLFLAG_CAPRD)) ||
1821                     (req->newptr && !(oid->oid_kind & CTLFLAG_CAPWR))) {
1822                         error = EPERM;
1823                         goto out;
1824                 }
1825         }
1826 #endif
1827
1828         /* Is this sysctl sensitive to securelevels? */
1829         if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) {
1830                 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE;
1831                 error = securelevel_gt(req->td->td_ucred, lvl);
1832                 if (error)
1833                         goto out;
1834         }
1835
1836         /* Is this sysctl writable by only privileged users? */
1837         if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) {
1838                 int priv;
1839
1840                 if (oid->oid_kind & CTLFLAG_PRISON)
1841                         priv = PRIV_SYSCTL_WRITEJAIL;
1842 #ifdef VIMAGE
1843                 else if ((oid->oid_kind & CTLFLAG_VNET) &&
1844                      prison_owns_vnet(req->td->td_ucred))
1845                         priv = PRIV_SYSCTL_WRITEJAIL;
1846 #endif
1847                 else
1848                         priv = PRIV_SYSCTL_WRITE;
1849                 error = priv_check(req->td, priv);
1850                 if (error)
1851                         goto out;
1852         }
1853
1854         if (!oid->oid_handler) {
1855                 error = EINVAL;
1856                 goto out;
1857         }
1858
1859         if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1860                 arg1 = (int *)arg1 + indx;
1861                 arg2 -= indx;
1862         } else {
1863                 arg1 = oid->oid_arg1;
1864                 arg2 = oid->oid_arg2;
1865         }
1866 #ifdef MAC
1867         error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2,
1868             req);
1869         if (error != 0)
1870                 goto out;
1871 #endif
1872 #ifdef VIMAGE
1873         if ((oid->oid_kind & CTLFLAG_VNET) && arg1 != NULL)
1874                 arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1);
1875 #endif
1876         error = sysctl_root_handler_locked(oid, arg1, arg2, req, &tracker);
1877
1878 out:
1879         SYSCTL_RUNLOCK(&tracker);
1880         return (error);
1881 }
1882
1883 #ifndef _SYS_SYSPROTO_H_
1884 struct sysctl_args {
1885         int     *name;
1886         u_int   namelen;
1887         void    *old;
1888         size_t  *oldlenp;
1889         void    *new;
1890         size_t  newlen;
1891 };
1892 #endif
1893 int
1894 sys___sysctl(struct thread *td, struct sysctl_args *uap)
1895 {
1896         int error, i, name[CTL_MAXNAME];
1897         size_t j;
1898
1899         if (uap->namelen > CTL_MAXNAME || uap->namelen < 2)
1900                 return (EINVAL);
1901
1902         error = copyin(uap->name, &name, uap->namelen * sizeof(int));
1903         if (error)
1904                 return (error);
1905
1906         error = userland_sysctl(td, name, uap->namelen,
1907                 uap->old, uap->oldlenp, 0,
1908                 uap->new, uap->newlen, &j, 0);
1909         if (error && error != ENOMEM)
1910                 return (error);
1911         if (uap->oldlenp) {
1912                 i = copyout(&j, uap->oldlenp, sizeof(j));
1913                 if (i)
1914                         return (i);
1915         }
1916         return (error);
1917 }
1918
1919 /*
1920  * This is used from various compatibility syscalls too.  That's why name
1921  * must be in kernel space.
1922  */
1923 int
1924 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old,
1925     size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval,
1926     int flags)
1927 {
1928         int error = 0, memlocked;
1929         struct sysctl_req req;
1930
1931         bzero(&req, sizeof req);
1932
1933         req.td = td;
1934         req.flags = flags;
1935
1936         if (oldlenp) {
1937                 if (inkernel) {
1938                         req.oldlen = *oldlenp;
1939                 } else {
1940                         error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp));
1941                         if (error)
1942                                 return (error);
1943                 }
1944         }
1945         req.validlen = req.oldlen;
1946
1947         if (old) {
1948                 if (!useracc(old, req.oldlen, VM_PROT_WRITE))
1949                         return (EFAULT);
1950                 req.oldptr= old;
1951         }
1952
1953         if (new != NULL) {
1954                 if (!useracc(new, newlen, VM_PROT_READ))
1955                         return (EFAULT);
1956                 req.newlen = newlen;
1957                 req.newptr = new;
1958         }
1959
1960         req.oldfunc = sysctl_old_user;
1961         req.newfunc = sysctl_new_user;
1962         req.lock = REQ_UNWIRED;
1963
1964 #ifdef KTRACE
1965         if (KTRPOINT(curthread, KTR_SYSCTL))
1966                 ktrsysctl(name, namelen);
1967 #endif
1968
1969         if (req.oldptr && req.oldlen > PAGE_SIZE) {
1970                 memlocked = 1;
1971                 sx_xlock(&sysctlmemlock);
1972         } else
1973                 memlocked = 0;
1974         CURVNET_SET(TD_TO_VNET(td));
1975
1976         for (;;) {
1977                 req.oldidx = 0;
1978                 req.newidx = 0;
1979                 error = sysctl_root(0, name, namelen, &req);
1980                 if (error != EAGAIN)
1981                         break;
1982                 kern_yield(PRI_USER);
1983         }
1984
1985         CURVNET_RESTORE();
1986
1987         if (req.lock == REQ_WIRED && req.validlen > 0)
1988                 vsunlock(req.oldptr, req.validlen);
1989         if (memlocked)
1990                 sx_xunlock(&sysctlmemlock);
1991
1992         if (error && error != ENOMEM)
1993                 return (error);
1994
1995         if (retval) {
1996                 if (req.oldptr && req.oldidx > req.validlen)
1997                         *retval = req.validlen;
1998                 else
1999                         *retval = req.oldidx;
2000         }
2001         return (error);
2002 }
2003
2004 /*
2005  * Drain into a sysctl struct.  The user buffer should be wired if a page
2006  * fault would cause issue.
2007  */
2008 static int
2009 sbuf_sysctl_drain(void *arg, const char *data, int len)
2010 {
2011         struct sysctl_req *req = arg;
2012         int error;
2013
2014         error = SYSCTL_OUT(req, data, len);
2015         KASSERT(error >= 0, ("Got unexpected negative value %d", error));
2016         return (error == 0 ? len : -error);
2017 }
2018
2019 struct sbuf *
2020 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length,
2021     struct sysctl_req *req)
2022 {
2023
2024         /* Supply a default buffer size if none given. */
2025         if (buf == NULL && length == 0)
2026                 length = 64;
2027         s = sbuf_new(s, buf, length, SBUF_FIXEDLEN | SBUF_INCLUDENUL);
2028         sbuf_set_drain(s, sbuf_sysctl_drain, req);
2029         return (s);
2030 }