sys/kern/kern_sysctl.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1982, 1986, 1989, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Mike Karels at Berkeley Software Design, Inc.
   9  *
  10  * Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD
  11  * project, to make these variables more userfriendly.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. Neither the name of the University nor the names of its contributors
  22  *    may be used to endorse or promote products derived from this software
  23  *    without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  35  * SUCH DAMAGE.
  36  *
  37  *      @(#)kern_sysctl.c       8.4 (Berkeley) 4/14/94
  38  */
  39
  40 #include <sys/cdefs.h>
  41 __FBSDID("$FreeBSD$");
  42
  43 #include "opt_capsicum.h"
  44 #include "opt_ktrace.h"
  45
  46 #include <sys/param.h>
  47 #include <sys/fail.h>
  48 #include <sys/systm.h>
  49 #include <sys/capsicum.h>
  50 #include <sys/kernel.h>
  51 #include <sys/sysctl.h>
  52 #include <sys/malloc.h>
  53 #include <sys/priv.h>
  54 #include <sys/proc.h>
  55 #include <sys/jail.h>
  56 #include <sys/lock.h>
  57 #include <sys/mutex.h>
  58 #include <sys/rmlock.h>
  59 #include <sys/sbuf.h>
  60 #include <sys/sx.h>
  61 #include <sys/sysproto.h>
  62 #include <sys/uio.h>
  63 #ifdef KTRACE
  64 #include <sys/ktrace.h>
  65 #endif
  66
  67 #include <net/vnet.h>
  68
  69 #include <security/mac/mac_framework.h>
  70
  71 #include <vm/vm.h>
  72 #include <vm/vm_extern.h>
  73
  74 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic");
  75 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids");
  76 static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer");
  77
  78 /*
  79  * The sysctllock protects the MIB tree.  It also protects sysctl
  80  * contexts used with dynamic sysctls.  The sysctl_register_oid() and
  81  * sysctl_unregister_oid() routines require the sysctllock to already
  82  * be held, so the sysctl_wlock() and sysctl_wunlock() routines are
  83  * provided for the few places in the kernel which need to use that
  84  * API rather than using the dynamic API.  Use of the dynamic API is
  85  * strongly encouraged for most code.
  86  *
  87  * The sysctlmemlock is used to limit the amount of user memory wired for
  88  * sysctl requests.  This is implemented by serializing any userland
  89  * sysctl requests larger than a single page via an exclusive lock.
  90  */
  91 static struct rmlock sysctllock;
  92 static struct sx __exclusive_cache_line sysctlmemlock;
  93
  94 #define SYSCTL_WLOCK()          rm_wlock(&sysctllock)
  95 #define SYSCTL_WUNLOCK()        rm_wunlock(&sysctllock)
  96 #define SYSCTL_RLOCK(tracker)   rm_rlock(&sysctllock, (tracker))
  97 #define SYSCTL_RUNLOCK(tracker) rm_runlock(&sysctllock, (tracker))
  98 #define SYSCTL_WLOCKED()        rm_wowned(&sysctllock)
  99 #define SYSCTL_ASSERT_LOCKED()  rm_assert(&sysctllock, RA_LOCKED)
 100 #define SYSCTL_ASSERT_WLOCKED() rm_assert(&sysctllock, RA_WLOCKED)
 101 #define SYSCTL_ASSERT_RLOCKED() rm_assert(&sysctllock, RA_RLOCKED)
 102 #define SYSCTL_INIT()           rm_init_flags(&sysctllock, "sysctl lock", \
 103                                     RM_SLEEPABLE)
 104 #define SYSCTL_SLEEP(ch, wmesg, timo)                                   \
 105                                 rm_sleep(ch, &sysctllock, 0, wmesg, timo)
 106
 107 static int sysctl_root(SYSCTL_HANDLER_ARGS);
 108
 109 /* Root list */
 110 struct sysctl_oid_list sysctl__children = SLIST_HEAD_INITIALIZER(&sysctl__children);
 111
 112 static int      sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del,
 113                     int recurse);
 114 static int      sysctl_old_kernel(struct sysctl_req *, const void *, size_t);
 115 static int      sysctl_new_kernel(struct sysctl_req *, void *, size_t);
 116
 117 static struct sysctl_oid *
 118 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list)
 119 {
 120         struct sysctl_oid *oidp;
 121
 122         SYSCTL_ASSERT_LOCKED();
 123         SLIST_FOREACH(oidp, list, oid_link) {
 124                 if (strcmp(oidp->oid_name, name) == 0) {
 125                         return (oidp);
 126                 }
 127         }
 128         return (NULL);
 129 }
 130
 131 /*
 132  * Initialization of the MIB tree.
 133  *
 134  * Order by number in each list.
 135  */
 136 void
 137 sysctl_wlock(void)
 138 {
 139
 140         SYSCTL_WLOCK();
 141 }
 142
 143 void
 144 sysctl_wunlock(void)
 145 {
 146
 147         SYSCTL_WUNLOCK();
 148 }
 149
 150 static int
 151 sysctl_root_handler_locked(struct sysctl_oid *oid, void *arg1, intmax_t arg2,
 152     struct sysctl_req *req, struct rm_priotracker *tracker)
 153 {
 154         int error;
 155
 156         if (oid->oid_kind & CTLFLAG_DYN)
 157                 atomic_add_int(&oid->oid_running, 1);
 158
 159         if (tracker != NULL)
 160                 SYSCTL_RUNLOCK(tracker);
 161         else
 162                 SYSCTL_WUNLOCK();
 163
 164         if (!(oid->oid_kind & CTLFLAG_MPSAFE))
 165                 mtx_lock(&Giant);
 166         error = oid->oid_handler(oid, arg1, arg2, req);
 167         if (!(oid->oid_kind & CTLFLAG_MPSAFE))
 168                 mtx_unlock(&Giant);
 169
 170         KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error);
 171
 172         if (tracker != NULL)
 173                 SYSCTL_RLOCK(tracker);
 174         else
 175                 SYSCTL_WLOCK();
 176
 177         if (oid->oid_kind & CTLFLAG_DYN) {
 178                 if (atomic_fetchadd_int(&oid->oid_running, -1) == 1 &&
 179                     (oid->oid_kind & CTLFLAG_DYING) != 0)
 180                         wakeup(&oid->oid_running);
 181         }
 182
 183         return (error);
 184 }
 185
 186 static void
 187 sysctl_load_tunable_by_oid_locked(struct sysctl_oid *oidp)
 188 {
 189         struct sysctl_req req;
 190         struct sysctl_oid *curr;
 191         char *penv = NULL;
 192         char path[96];
 193         ssize_t rem = sizeof(path);
 194         ssize_t len;
 195         uint8_t val_8;
 196         uint16_t val_16;
 197         uint32_t val_32;
 198         int val_int;
 199         long val_long;
 200         int64_t val_64;
 201         quad_t val_quad;
 202         int error;
 203
 204         path[--rem] = 0;
 205
 206         for (curr = oidp; curr != NULL; curr = SYSCTL_PARENT(curr)) {
 207                 len = strlen(curr->oid_name);
 208                 rem -= len;
 209                 if (curr != oidp)
 210                         rem -= 1;
 211                 if (rem < 0) {
 212                         printf("OID path exceeds %d bytes\n", (int)sizeof(path));
 213                         return;
 214                 }
 215                 memcpy(path + rem, curr->oid_name, len);
 216                 if (curr != oidp)
 217                         path[rem + len] = '.';
 218         }
 219
 220         memset(&req, 0, sizeof(req));
 221
 222         req.td = curthread;
 223         req.oldfunc = sysctl_old_kernel;
 224         req.newfunc = sysctl_new_kernel;
 225         req.lock = REQ_UNWIRED;
 226
 227         switch (oidp->oid_kind & CTLTYPE) {
 228         case CTLTYPE_INT:
 229                 if (getenv_int(path + rem, &val_int) == 0)
 230                         return;
 231                 req.newlen = sizeof(val_int);
 232                 req.newptr = &val_int;
 233                 break;
 234         case CTLTYPE_UINT:
 235                 if (getenv_uint(path + rem, (unsigned int *)&val_int) == 0)
 236                         return;
 237                 req.newlen = sizeof(val_int);
 238                 req.newptr = &val_int;
 239                 break;
 240         case CTLTYPE_LONG:
 241                 if (getenv_long(path + rem, &val_long) == 0)
 242                         return;
 243                 req.newlen = sizeof(val_long);
 244                 req.newptr = &val_long;
 245                 break;
 246         case CTLTYPE_ULONG:
 247                 if (getenv_ulong(path + rem, (unsigned long *)&val_long) == 0)
 248                         return;
 249                 req.newlen = sizeof(val_long);
 250                 req.newptr = &val_long;
 251                 break;
 252         case CTLTYPE_S8:
 253                 if (getenv_int(path + rem, &val_int) == 0)
 254                         return;
 255                 val_8 = val_int;
 256                 req.newlen = sizeof(val_8);
 257                 req.newptr = &val_8;
 258                 break;
 259         case CTLTYPE_S16:
 260                 if (getenv_int(path + rem, &val_int) == 0)
 261                         return;
 262                 val_16 = val_int;
 263                 req.newlen = sizeof(val_16);
 264                 req.newptr = &val_16;
 265                 break;
 266         case CTLTYPE_S32:
 267                 if (getenv_long(path + rem, &val_long) == 0)
 268                         return;
 269                 val_32 = val_long;
 270                 req.newlen = sizeof(val_32);
 271                 req.newptr = &val_32;
 272                 break;
 273         case CTLTYPE_S64:
 274                 if (getenv_quad(path + rem, &val_quad) == 0)
 275                         return;
 276                 val_64 = val_quad;
 277                 req.newlen = sizeof(val_64);
 278                 req.newptr = &val_64;
 279                 break;
 280         case CTLTYPE_U8:
 281                 if (getenv_uint(path + rem, (unsigned int *)&val_int) == 0)
 282                         return;
 283                 val_8 = val_int;
 284                 req.newlen = sizeof(val_8);
 285                 req.newptr = &val_8;
 286                 break;
 287         case CTLTYPE_U16:
 288                 if (getenv_uint(path + rem, (unsigned int *)&val_int) == 0)
 289                         return;
 290                 val_16 = val_int;
 291                 req.newlen = sizeof(val_16);
 292                 req.newptr = &val_16;
 293                 break;
 294         case CTLTYPE_U32:
 295                 if (getenv_ulong(path + rem, (unsigned long *)&val_long) == 0)
 296                         return;
 297                 val_32 = val_long;
 298                 req.newlen = sizeof(val_32);
 299                 req.newptr = &val_32;
 300                 break;
 301         case CTLTYPE_U64:
 302                 /* XXX there is no getenv_uquad() */
 303                 if (getenv_quad(path + rem, &val_quad) == 0)
 304                         return;
 305                 val_64 = val_quad;
 306                 req.newlen = sizeof(val_64);
 307                 req.newptr = &val_64;
 308                 break;
 309         case CTLTYPE_STRING:
 310                 penv = kern_getenv(path + rem);
 311                 if (penv == NULL)
 312                         return;
 313                 req.newlen = strlen(penv);
 314                 req.newptr = penv;
 315                 break;
 316         default:
 317                 return;
 318         }
 319         error = sysctl_root_handler_locked(oidp, oidp->oid_arg1,
 320             oidp->oid_arg2, &req, NULL);
 321         if (error != 0)
 322                 printf("Setting sysctl %s failed: %d\n", path + rem, error);
 323         if (penv != NULL)
 324                 freeenv(penv);
 325 }
 326
 327 static int
 328 sbuf_printf_drain(void *arg __unused, const char *data, int len)
 329 {
 330
 331         return (printf("%.*s", len, data));
 332 }
 333
 334 /*
 335  * Locate the path to a given oid.  Returns the length of the resulting path,
 336  * or -1 if the oid was not found.  nodes must have room for CTL_MAXNAME
 337  * elements and be NULL initialized.
 338  */
 339 static int
 340 sysctl_search_oid(struct sysctl_oid **nodes, struct sysctl_oid *needle)
 341 {
 342         int indx;
 343
 344         SYSCTL_ASSERT_LOCKED();
 345         indx = 0;
 346         while (indx < CTL_MAXNAME && indx >= 0) {
 347                 if (nodes[indx] == NULL && indx == 0)
 348                         nodes[indx] = SLIST_FIRST(&sysctl__children);
 349                 else if (nodes[indx] == NULL)
 350                         nodes[indx] = SLIST_FIRST(&nodes[indx - 1]->oid_children);
 351                 else
 352                         nodes[indx] = SLIST_NEXT(nodes[indx], oid_link);
 353
 354                 if (nodes[indx] == needle)
 355                         return (indx + 1);
 356
 357                 if (nodes[indx] == NULL) {
 358                         indx--;
 359                         continue;
 360                 }
 361
 362                 if ((nodes[indx]->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
 363                         indx++;
 364                         continue;
 365                 }
 366         }
 367         return (-1);
 368 }
 369
 370 static void
 371 sysctl_warn_reuse(const char *func, struct sysctl_oid *leaf)
 372 {
 373         struct sysctl_oid *nodes[CTL_MAXNAME];
 374         char buf[128];
 375         struct sbuf sb;
 376         int rc, i;
 377
 378         (void)sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN | SBUF_INCLUDENUL);
 379         sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
 380
 381         sbuf_printf(&sb, "%s: can't re-use a leaf (", __func__);
 382
 383         memset(nodes, 0, sizeof(nodes));
 384         rc = sysctl_search_oid(nodes, leaf);
 385         if (rc > 0) {
 386                 for (i = 0; i < rc; i++)
 387                         sbuf_printf(&sb, "%s%.*s", nodes[i]->oid_name,
 388                             i != (rc - 1), ".");
 389         } else {
 390                 sbuf_printf(&sb, "%s", leaf->oid_name);
 391         }
 392         sbuf_printf(&sb, ")!\n");
 393
 394         (void)sbuf_finish(&sb);
 395 }
 396
 397 #ifdef SYSCTL_DEBUG
 398 static int
 399 sysctl_reuse_test(SYSCTL_HANDLER_ARGS)
 400 {
 401         struct rm_priotracker tracker;
 402
 403         SYSCTL_RLOCK(&tracker);
 404         sysctl_warn_reuse(__func__, oidp);
 405         SYSCTL_RUNLOCK(&tracker);
 406         return (0);
 407 }
 408 SYSCTL_PROC(_sysctl, 0, reuse_test, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE,
 409         0, 0, sysctl_reuse_test, "-", "");
 410 #endif
 411
 412 void
 413 sysctl_register_oid(struct sysctl_oid *oidp)
 414 {
 415         struct sysctl_oid_list *parent = oidp->oid_parent;
 416         struct sysctl_oid *p;
 417         struct sysctl_oid *q;
 418         int oid_number;
 419         int timeout = 2;
 420
 421         /*
 422          * First check if another oid with the same name already
 423          * exists in the parent's list.
 424          */
 425         SYSCTL_ASSERT_WLOCKED();
 426         p = sysctl_find_oidname(oidp->oid_name, parent);
 427         if (p != NULL) {
 428                 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
 429                         p->oid_refcnt++;
 430                         return;
 431                 } else {
 432                         sysctl_warn_reuse(__func__, p);
 433                         return;
 434                 }
 435         }
 436         /* get current OID number */
 437         oid_number = oidp->oid_number;
 438
 439 #if (OID_AUTO >= 0)
 440 #error "OID_AUTO is expected to be a negative value"
 441 #endif
 442         /*
 443          * Any negative OID number qualifies as OID_AUTO. Valid OID
 444          * numbers should always be positive.
 445          *
 446          * NOTE: DO NOT change the starting value here, change it in
 447          * <sys/sysctl.h>, and make sure it is at least 256 to
 448          * accommodate e.g. net.inet.raw as a static sysctl node.
 449          */
 450         if (oid_number < 0) {
 451                 static int newoid;
 452
 453                 /*
 454                  * By decrementing the next OID number we spend less
 455                  * time inserting the OIDs into a sorted list.
 456                  */
 457                 if (--newoid < CTL_AUTO_START)
 458                         newoid = 0x7fffffff;
 459
 460                 oid_number = newoid;
 461         }
 462
 463         /*
 464          * Insert the OID into the parent's list sorted by OID number.
 465          */
 466 retry:
 467         q = NULL;
 468         SLIST_FOREACH(p, parent, oid_link) {
 469                 /* check if the current OID number is in use */
 470                 if (oid_number == p->oid_number) {
 471                         /* get the next valid OID number */
 472                         if (oid_number < CTL_AUTO_START ||
 473                             oid_number == 0x7fffffff) {
 474                                 /* wraparound - restart */
 475                                 oid_number = CTL_AUTO_START;
 476                                 /* don't loop forever */
 477                                 if (!timeout--)
 478                                         panic("sysctl: Out of OID numbers\n");
 479                                 goto retry;
 480                         } else {
 481                                 oid_number++;
 482                         }
 483                 } else if (oid_number < p->oid_number)
 484                         break;
 485                 q = p;
 486         }
 487         /* check for non-auto OID number collision */
 488         if (oidp->oid_number >= 0 && oidp->oid_number < CTL_AUTO_START &&
 489             oid_number >= CTL_AUTO_START) {
 490                 printf("sysctl: OID number(%d) is already in use for '%s'\n",
 491                     oidp->oid_number, oidp->oid_name);
 492         }
 493         /* update the OID number, if any */
 494         oidp->oid_number = oid_number;
 495         if (q != NULL)
 496                 SLIST_INSERT_AFTER(q, oidp, oid_link);
 497         else
 498                 SLIST_INSERT_HEAD(parent, oidp, oid_link);
 499
 500         if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE &&
 501 #ifdef VIMAGE
 502             (oidp->oid_kind & CTLFLAG_VNET) == 0 &&
 503 #endif
 504             (oidp->oid_kind & CTLFLAG_TUN) != 0 &&
 505             (oidp->oid_kind & CTLFLAG_NOFETCH) == 0) {
 506                 /* only fetch value once */
 507                 oidp->oid_kind |= CTLFLAG_NOFETCH;
 508                 /* try to fetch value from kernel environment */
 509                 sysctl_load_tunable_by_oid_locked(oidp);
 510         }
 511 }
 512
 513 void
 514 sysctl_register_disabled_oid(struct sysctl_oid *oidp)
 515 {
 516
 517         /*
 518          * Mark the leaf as dormant if it's not to be immediately enabled.
 519          * We do not disable nodes as they can be shared between modules
 520          * and it is always safe to access a node.
 521          */
 522         KASSERT((oidp->oid_kind & CTLFLAG_DORMANT) == 0,
 523             ("internal flag is set in oid_kind"));
 524         if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
 525                 oidp->oid_kind |= CTLFLAG_DORMANT;
 526         sysctl_register_oid(oidp);
 527 }
 528
 529 void
 530 sysctl_enable_oid(struct sysctl_oid *oidp)
 531 {
 532
 533         SYSCTL_ASSERT_WLOCKED();
 534         if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
 535                 KASSERT((oidp->oid_kind & CTLFLAG_DORMANT) == 0,
 536                     ("sysctl node is marked as dormant"));
 537                 return;
 538         }
 539         KASSERT((oidp->oid_kind & CTLFLAG_DORMANT) != 0,
 540             ("enabling already enabled sysctl oid"));
 541         oidp->oid_kind &= ~CTLFLAG_DORMANT;
 542 }
 543
 544 void
 545 sysctl_unregister_oid(struct sysctl_oid *oidp)
 546 {
 547         struct sysctl_oid *p;
 548         int error;
 549
 550         SYSCTL_ASSERT_WLOCKED();
 551         error = ENOENT;
 552         if (oidp->oid_number == OID_AUTO) {
 553                 error = EINVAL;
 554         } else {
 555                 SLIST_FOREACH(p, oidp->oid_parent, oid_link) {
 556                         if (p == oidp) {
 557                                 SLIST_REMOVE(oidp->oid_parent, oidp,
 558                                     sysctl_oid, oid_link);
 559                                 error = 0;
 560                                 break;
 561                         }
 562                 }
 563         }
 564
 565         /*
 566          * This can happen when a module fails to register and is
 567          * being unloaded afterwards.  It should not be a panic()
 568          * for normal use.
 569          */
 570         if (error)
 571                 printf("%s: failed to unregister sysctl\n", __func__);
 572 }
 573
 574 /* Initialize a new context to keep track of dynamically added sysctls. */
 575 int
 576 sysctl_ctx_init(struct sysctl_ctx_list *c)
 577 {
 578
 579         if (c == NULL) {
 580                 return (EINVAL);
 581         }
 582
 583         /*
 584          * No locking here, the caller is responsible for not adding
 585          * new nodes to a context until after this function has
 586          * returned.
 587          */
 588         TAILQ_INIT(c);
 589         return (0);
 590 }
 591
 592 /* Free the context, and destroy all dynamic oids registered in this context */
 593 int
 594 sysctl_ctx_free(struct sysctl_ctx_list *clist)
 595 {
 596         struct sysctl_ctx_entry *e, *e1;
 597         int error;
 598
 599         error = 0;
 600         /*
 601          * First perform a "dry run" to check if it's ok to remove oids.
 602          * XXX FIXME
 603          * XXX This algorithm is a hack. But I don't know any
 604          * XXX better solution for now...
 605          */
 606         SYSCTL_WLOCK();
 607         TAILQ_FOREACH(e, clist, link) {
 608                 error = sysctl_remove_oid_locked(e->entry, 0, 0);
 609                 if (error)
 610                         break;
 611         }
 612         /*
 613          * Restore deregistered entries, either from the end,
 614          * or from the place where error occurred.
 615          * e contains the entry that was not unregistered
 616          */
 617         if (error)
 618                 e1 = TAILQ_PREV(e, sysctl_ctx_list, link);
 619         else
 620                 e1 = TAILQ_LAST(clist, sysctl_ctx_list);
 621         while (e1 != NULL) {
 622                 sysctl_register_oid(e1->entry);
 623                 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link);
 624         }
 625         if (error) {
 626                 SYSCTL_WUNLOCK();
 627                 return(EBUSY);
 628         }
 629         /* Now really delete the entries */
 630         e = TAILQ_FIRST(clist);
 631         while (e != NULL) {
 632                 e1 = TAILQ_NEXT(e, link);
 633                 error = sysctl_remove_oid_locked(e->entry, 1, 0);
 634                 if (error)
 635                         panic("sysctl_remove_oid: corrupt tree, entry: %s",
 636                             e->entry->oid_name);
 637                 free(e, M_SYSCTLOID);
 638                 e = e1;
 639         }
 640         SYSCTL_WUNLOCK();
 641         return (error);
 642 }
 643
 644 /* Add an entry to the context */
 645 struct sysctl_ctx_entry *
 646 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
 647 {
 648         struct sysctl_ctx_entry *e;
 649
 650         SYSCTL_ASSERT_WLOCKED();
 651         if (clist == NULL || oidp == NULL)
 652                 return(NULL);
 653         e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK);
 654         e->entry = oidp;
 655         TAILQ_INSERT_HEAD(clist, e, link);
 656         return (e);
 657 }
 658
 659 /* Find an entry in the context */
 660 struct sysctl_ctx_entry *
 661 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
 662 {
 663         struct sysctl_ctx_entry *e;
 664
 665         SYSCTL_ASSERT_WLOCKED();
 666         if (clist == NULL || oidp == NULL)
 667                 return(NULL);
 668         TAILQ_FOREACH(e, clist, link) {
 669                 if(e->entry == oidp)
 670                         return(e);
 671         }
 672         return (e);
 673 }
 674
 675 /*
 676  * Delete an entry from the context.
 677  * NOTE: this function doesn't free oidp! You have to remove it
 678  * with sysctl_remove_oid().
 679  */
 680 int
 681 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
 682 {
 683         struct sysctl_ctx_entry *e;
 684
 685         if (clist == NULL || oidp == NULL)
 686                 return (EINVAL);
 687         SYSCTL_WLOCK();
 688         e = sysctl_ctx_entry_find(clist, oidp);
 689         if (e != NULL) {
 690                 TAILQ_REMOVE(clist, e, link);
 691                 SYSCTL_WUNLOCK();
 692                 free(e, M_SYSCTLOID);
 693                 return (0);
 694         } else {
 695                 SYSCTL_WUNLOCK();
 696                 return (ENOENT);
 697         }
 698 }
 699
 700 /*
 701  * Remove dynamically created sysctl trees.
 702  * oidp - top of the tree to be removed
 703  * del - if 0 - just deregister, otherwise free up entries as well
 704  * recurse - if != 0 traverse the subtree to be deleted
 705  */
 706 int
 707 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse)
 708 {
 709         int error;
 710
 711         SYSCTL_WLOCK();
 712         error = sysctl_remove_oid_locked(oidp, del, recurse);
 713         SYSCTL_WUNLOCK();
 714         return (error);
 715 }
 716
 717 int
 718 sysctl_remove_name(struct sysctl_oid *parent, const char *name,
 719     int del, int recurse)
 720 {
 721         struct sysctl_oid *p, *tmp;
 722         int error;
 723
 724         error = ENOENT;
 725         SYSCTL_WLOCK();
 726         SLIST_FOREACH_SAFE(p, SYSCTL_CHILDREN(parent), oid_link, tmp) {
 727                 if (strcmp(p->oid_name, name) == 0) {
 728                         error = sysctl_remove_oid_locked(p, del, recurse);
 729                         break;
 730                 }
 731         }
 732         SYSCTL_WUNLOCK();
 733
 734         return (error);
 735 }
 736
 737
 738 static int
 739 sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse)
 740 {
 741         struct sysctl_oid *p, *tmp;
 742         int error;
 743
 744         SYSCTL_ASSERT_WLOCKED();
 745         if (oidp == NULL)
 746                 return(EINVAL);
 747         if ((oidp->oid_kind & CTLFLAG_DYN) == 0) {
 748                 printf("Warning: can't remove non-dynamic nodes (%s)!\n",
 749                     oidp->oid_name);
 750                 return (EINVAL);
 751         }
 752         /*
 753          * WARNING: normal method to do this should be through
 754          * sysctl_ctx_free(). Use recursing as the last resort
 755          * method to purge your sysctl tree of leftovers...
 756          * However, if some other code still references these nodes,
 757          * it will panic.
 758          */
 759         if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
 760                 if (oidp->oid_refcnt == 1) {
 761                         SLIST_FOREACH_SAFE(p,
 762                             SYSCTL_CHILDREN(oidp), oid_link, tmp) {
 763                                 if (!recurse) {
 764                                         printf("Warning: failed attempt to "
 765                                             "remove oid %s with child %s\n",
 766                                             oidp->oid_name, p->oid_name);
 767                                         return (ENOTEMPTY);
 768                                 }
 769                                 error = sysctl_remove_oid_locked(p, del,
 770                                     recurse);
 771                                 if (error)
 772                                         return (error);
 773                         }
 774                 }
 775         }
 776         if (oidp->oid_refcnt > 1 ) {
 777                 oidp->oid_refcnt--;
 778         } else {
 779                 if (oidp->oid_refcnt == 0) {
 780                         printf("Warning: bad oid_refcnt=%u (%s)!\n",
 781                                 oidp->oid_refcnt, oidp->oid_name);
 782                         return (EINVAL);
 783                 }
 784                 sysctl_unregister_oid(oidp);
 785                 if (del) {
 786                         /*
 787                          * Wait for all threads running the handler to drain.
 788                          * This preserves the previous behavior when the
 789                          * sysctl lock was held across a handler invocation,
 790                          * and is necessary for module unload correctness.
 791                          */
 792                         while (oidp->oid_running > 0) {
 793                                 oidp->oid_kind |= CTLFLAG_DYING;
 794                                 SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0);
 795                         }
 796                         if (oidp->oid_descr)
 797                                 free(__DECONST(char *, oidp->oid_descr),
 798                                     M_SYSCTLOID);
 799                         if (oidp->oid_label)
 800                                 free(__DECONST(char *, oidp->oid_label),
 801                                     M_SYSCTLOID);
 802                         free(__DECONST(char *, oidp->oid_name), M_SYSCTLOID);
 803                         free(oidp, M_SYSCTLOID);
 804                 }
 805         }
 806         return (0);
 807 }
 808 /*
 809  * Create new sysctls at run time.
 810  * clist may point to a valid context initialized with sysctl_ctx_init().
 811  */
 812 struct sysctl_oid *
 813 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent,
 814         int number, const char *name, int kind, void *arg1, intmax_t arg2,
 815         int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr,
 816         const char *label)
 817 {
 818         struct sysctl_oid *oidp;
 819
 820         /* You have to hook up somewhere.. */
 821         if (parent == NULL)
 822                 return(NULL);
 823         /* Check if the node already exists, otherwise create it */
 824         SYSCTL_WLOCK();
 825         oidp = sysctl_find_oidname(name, parent);
 826         if (oidp != NULL) {
 827                 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
 828                         oidp->oid_refcnt++;
 829                         /* Update the context */
 830                         if (clist != NULL)
 831                                 sysctl_ctx_entry_add(clist, oidp);
 832                         SYSCTL_WUNLOCK();
 833                         return (oidp);
 834                 } else {
 835                         sysctl_warn_reuse(__func__, oidp);
 836                         SYSCTL_WUNLOCK();
 837                         return (NULL);
 838                 }
 839         }
 840         oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO);
 841         oidp->oid_parent = parent;
 842         SLIST_INIT(&oidp->oid_children);
 843         oidp->oid_number = number;
 844         oidp->oid_refcnt = 1;
 845         oidp->oid_name = strdup(name, M_SYSCTLOID);
 846         oidp->oid_handler = handler;
 847         oidp->oid_kind = CTLFLAG_DYN | kind;
 848         oidp->oid_arg1 = arg1;
 849         oidp->oid_arg2 = arg2;
 850         oidp->oid_fmt = fmt;
 851         if (descr != NULL)
 852                 oidp->oid_descr = strdup(descr, M_SYSCTLOID);
 853         if (label != NULL)
 854                 oidp->oid_label = strdup(label, M_SYSCTLOID);
 855         /* Update the context, if used */
 856         if (clist != NULL)
 857                 sysctl_ctx_entry_add(clist, oidp);
 858         /* Register this oid */
 859         sysctl_register_oid(oidp);
 860         SYSCTL_WUNLOCK();
 861         return (oidp);
 862 }
 863
 864 /*
 865  * Rename an existing oid.
 866  */
 867 void
 868 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name)
 869 {
 870         char *newname;
 871         char *oldname;
 872
 873         newname = strdup(name, M_SYSCTLOID);
 874         SYSCTL_WLOCK();
 875         oldname = __DECONST(char *, oidp->oid_name);
 876         oidp->oid_name = newname;
 877         SYSCTL_WUNLOCK();
 878         free(oldname, M_SYSCTLOID);
 879 }
 880
 881 /*
 882  * Reparent an existing oid.
 883  */
 884 int
 885 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent)
 886 {
 887         struct sysctl_oid *oidp;
 888
 889         SYSCTL_WLOCK();
 890         if (oid->oid_parent == parent) {
 891                 SYSCTL_WUNLOCK();
 892                 return (0);
 893         }
 894         oidp = sysctl_find_oidname(oid->oid_name, parent);
 895         if (oidp != NULL) {
 896                 SYSCTL_WUNLOCK();
 897                 return (EEXIST);
 898         }
 899         sysctl_unregister_oid(oid);
 900         oid->oid_parent = parent;
 901         oid->oid_number = OID_AUTO;
 902         sysctl_register_oid(oid);
 903         SYSCTL_WUNLOCK();
 904         return (0);
 905 }
 906
 907 /*
 908  * Register the kernel's oids on startup.
 909  */
 910 SET_DECLARE(sysctl_set, struct sysctl_oid);
 911
 912 static void
 913 sysctl_register_all(void *arg)
 914 {
 915         struct sysctl_oid **oidp;
 916
 917         sx_init(&sysctlmemlock, "sysctl mem");
 918         SYSCTL_INIT();
 919         SYSCTL_WLOCK();
 920         SET_FOREACH(oidp, sysctl_set)
 921                 sysctl_register_oid(*oidp);
 922         SYSCTL_WUNLOCK();
 923 }
 924 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_FIRST, sysctl_register_all, NULL);
 925
 926 /*
 927  * "Staff-functions"
 928  *
 929  * These functions implement a presently undocumented interface
 930  * used by the sysctl program to walk the tree, and get the type
 931  * so it can print the value.
 932  * This interface is under work and consideration, and should probably
 933  * be killed with a big axe by the first person who can find the time.
 934  * (be aware though, that the proper interface isn't as obvious as it
 935  * may seem, there are various conflicting requirements.
 936  *
 937  * {0,0}        printf the entire MIB-tree.
 938  * {0,1,...}    return the name of the "..." OID.
 939  * {0,2,...}    return the next OID.
 940  * {0,3}        return the OID of the name in "new"
 941  * {0,4,...}    return the kind & format info for the "..." OID.
 942  * {0,5,...}    return the description of the "..." OID.
 943  * {0,6,...}    return the aggregation label of the "..." OID.
 944  */
 945
 946 #ifdef SYSCTL_DEBUG
 947 static void
 948 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i)
 949 {
 950         int k;
 951         struct sysctl_oid *oidp;
 952
 953         SYSCTL_ASSERT_LOCKED();
 954         SLIST_FOREACH(oidp, l, oid_link) {
 955
 956                 for (k=0; k<i; k++)
 957                         printf(" ");
 958
 959                 printf("%d %s ", oidp->oid_number, oidp->oid_name);
 960
 961                 printf("%c%c",
 962                         oidp->oid_kind & CTLFLAG_RD ? 'R':' ',
 963                         oidp->oid_kind & CTLFLAG_WR ? 'W':' ');
 964
 965                 if (oidp->oid_handler)
 966                         printf(" *Handler");
 967
 968                 switch (oidp->oid_kind & CTLTYPE) {
 969                         case CTLTYPE_NODE:
 970                                 printf(" Node\n");
 971                                 if (!oidp->oid_handler) {
 972                                         sysctl_sysctl_debug_dump_node(
 973                                             SYSCTL_CHILDREN(oidp), i + 2);
 974                                 }
 975                                 break;
 976                         case CTLTYPE_INT:    printf(" Int\n"); break;
 977                         case CTLTYPE_UINT:   printf(" u_int\n"); break;
 978                         case CTLTYPE_LONG:   printf(" Long\n"); break;
 979                         case CTLTYPE_ULONG:  printf(" u_long\n"); break;
 980                         case CTLTYPE_STRING: printf(" String\n"); break;
 981                         case CTLTYPE_S8:     printf(" int8_t\n"); break;
 982                         case CTLTYPE_S16:    printf(" int16_t\n"); break;
 983                         case CTLTYPE_S32:    printf(" int32_t\n"); break;
 984                         case CTLTYPE_S64:    printf(" int64_t\n"); break;
 985                         case CTLTYPE_U8:     printf(" uint8_t\n"); break;
 986                         case CTLTYPE_U16:    printf(" uint16_t\n"); break;
 987                         case CTLTYPE_U32:    printf(" uint32_t\n"); break;
 988                         case CTLTYPE_U64:    printf(" uint64_t\n"); break;
 989                         case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break;
 990                         default:             printf("\n");
 991                 }
 992
 993         }
 994 }
 995
 996 static int
 997 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS)
 998 {
 999         struct rm_priotracker tracker;
1000         int error;
1001
1002         error = priv_check(req->td, PRIV_SYSCTL_DEBUG);
1003         if (error)
1004                 return (error);
1005         SYSCTL_RLOCK(&tracker);
1006         sysctl_sysctl_debug_dump_node(&sysctl__children, 0);
1007         SYSCTL_RUNLOCK(&tracker);
1008         return (ENOENT);
1009 }
1010
1011 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE,
1012         0, 0, sysctl_sysctl_debug, "-", "");
1013 #endif
1014
1015 static int
1016 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS)
1017 {
1018         int *name = (int *) arg1;
1019         u_int namelen = arg2;
1020         int error = 0;
1021         struct sysctl_oid *oid;
1022         struct sysctl_oid_list *lsp = &sysctl__children, *lsp2;
1023         struct rm_priotracker tracker;
1024         char buf[10];
1025
1026         SYSCTL_RLOCK(&tracker);
1027         while (namelen) {
1028                 if (!lsp) {
1029                         snprintf(buf,sizeof(buf),"%d",*name);
1030                         if (req->oldidx)
1031                                 error = SYSCTL_OUT(req, ".", 1);
1032                         if (!error)
1033                                 error = SYSCTL_OUT(req, buf, strlen(buf));
1034                         if (error)
1035                                 goto out;
1036                         namelen--;
1037                         name++;
1038                         continue;
1039                 }
1040                 lsp2 = NULL;
1041                 SLIST_FOREACH(oid, lsp, oid_link) {
1042                         if (oid->oid_number != *name)
1043                                 continue;
1044
1045                         if (req->oldidx)
1046                                 error = SYSCTL_OUT(req, ".", 1);
1047                         if (!error)
1048                                 error = SYSCTL_OUT(req, oid->oid_name,
1049                                         strlen(oid->oid_name));
1050                         if (error)
1051                                 goto out;
1052
1053                         namelen--;
1054                         name++;
1055
1056                         if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE)
1057                                 break;
1058
1059                         if (oid->oid_handler)
1060                                 break;
1061
1062                         lsp2 = SYSCTL_CHILDREN(oid);
1063                         break;
1064                 }
1065                 lsp = lsp2;
1066         }
1067         error = SYSCTL_OUT(req, "", 1);
1068  out:
1069         SYSCTL_RUNLOCK(&tracker);
1070         return (error);
1071 }
1072
1073 /*
1074  * XXXRW/JA: Shouldn't return name data for nodes that we don't permit in
1075  * capability mode.
1076  */
1077 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD,
1078     sysctl_sysctl_name, "");
1079
1080 static int
1081 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen,
1082         int *next, int *len, int level, struct sysctl_oid **oidpp)
1083 {
1084         struct sysctl_oid *oidp;
1085
1086         SYSCTL_ASSERT_LOCKED();
1087         *len = level;
1088         SLIST_FOREACH(oidp, lsp, oid_link) {
1089                 *next = oidp->oid_number;
1090                 *oidpp = oidp;
1091
1092                 if ((oidp->oid_kind & (CTLFLAG_SKIP | CTLFLAG_DORMANT)) != 0)
1093                         continue;
1094
1095                 if (!namelen) {
1096                         if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
1097                                 return (0);
1098                         if (oidp->oid_handler)
1099                                 /* We really should call the handler here...*/
1100                                 return (0);
1101                         lsp = SYSCTL_CHILDREN(oidp);
1102                         if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1,
1103                                 len, level+1, oidpp))
1104                                 return (0);
1105                         goto emptynode;
1106                 }
1107
1108                 if (oidp->oid_number < *name)
1109                         continue;
1110
1111                 if (oidp->oid_number > *name) {
1112                         if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
1113                                 return (0);
1114                         if (oidp->oid_handler)
1115                                 return (0);
1116                         lsp = SYSCTL_CHILDREN(oidp);
1117                         if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1,
1118                                 next+1, len, level+1, oidpp))
1119                                 return (0);
1120                         goto next;
1121                 }
1122                 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
1123                         continue;
1124
1125                 if (oidp->oid_handler)
1126                         continue;
1127
1128                 lsp = SYSCTL_CHILDREN(oidp);
1129                 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1,
1130                         len, level+1, oidpp))
1131                         return (0);
1132         next:
1133                 namelen = 1;
1134         emptynode:
1135                 *len = level;
1136         }
1137         return (1);
1138 }
1139
1140 static int
1141 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS)
1142 {
1143         int *name = (int *) arg1;
1144         u_int namelen = arg2;
1145         int i, j, error;
1146         struct sysctl_oid *oid;
1147         struct sysctl_oid_list *lsp = &sysctl__children;
1148         struct rm_priotracker tracker;
1149         int newoid[CTL_MAXNAME];
1150
1151         SYSCTL_RLOCK(&tracker);
1152         i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid);
1153         SYSCTL_RUNLOCK(&tracker);
1154         if (i)
1155                 return (ENOENT);
1156         error = SYSCTL_OUT(req, newoid, j * sizeof (int));
1157         return (error);
1158 }
1159
1160 /*
1161  * XXXRW/JA: Shouldn't return next data for nodes that we don't permit in
1162  * capability mode.
1163  */
1164 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD,
1165     sysctl_sysctl_next, "");
1166
1167 static int
1168 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp)
1169 {
1170         struct sysctl_oid *oidp;
1171         struct sysctl_oid_list *lsp = &sysctl__children;
1172         char *p;
1173
1174         SYSCTL_ASSERT_LOCKED();
1175
1176         for (*len = 0; *len < CTL_MAXNAME;) {
1177                 p = strsep(&name, ".");
1178
1179                 oidp = SLIST_FIRST(lsp);
1180                 for (;; oidp = SLIST_NEXT(oidp, oid_link)) {
1181                         if (oidp == NULL)
1182                                 return (ENOENT);
1183                         if (strcmp(p, oidp->oid_name) == 0)
1184                                 break;
1185                 }
1186                 *oid++ = oidp->oid_number;
1187                 (*len)++;
1188
1189                 if (name == NULL || *name == '\0') {
1190                         if (oidpp)
1191                                 *oidpp = oidp;
1192                         return (0);
1193                 }
1194
1195                 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
1196                         break;
1197
1198                 if (oidp->oid_handler)
1199                         break;
1200
1201                 lsp = SYSCTL_CHILDREN(oidp);
1202         }
1203         return (ENOENT);
1204 }
1205
1206 static int
1207 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
1208 {
1209         char *p;
1210         int error, oid[CTL_MAXNAME], len = 0;
1211         struct sysctl_oid *op = NULL;
1212         struct rm_priotracker tracker;
1213         char buf[32];
1214
1215         if (!req->newlen)
1216                 return (ENOENT);
1217         if (req->newlen >= MAXPATHLEN)  /* XXX arbitrary, undocumented */
1218                 return (ENAMETOOLONG);
1219
1220         p = buf;
1221         if (req->newlen >= sizeof(buf))
1222                 p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK);
1223
1224         error = SYSCTL_IN(req, p, req->newlen);
1225         if (error) {
1226                 if (p != buf)
1227                         free(p, M_SYSCTL);
1228                 return (error);
1229         }
1230
1231         p [req->newlen] = '\0';
1232
1233         SYSCTL_RLOCK(&tracker);
1234         error = name2oid(p, oid, &len, &op);
1235         SYSCTL_RUNLOCK(&tracker);
1236
1237         if (p != buf)
1238                 free(p, M_SYSCTL);
1239
1240         if (error)
1241                 return (error);
1242
1243         error = SYSCTL_OUT(req, oid, len * sizeof *oid);
1244         return (error);
1245 }
1246
1247 /*
1248  * XXXRW/JA: Shouldn't return name2oid data for nodes that we don't permit in
1249  * capability mode.
1250  */
1251 SYSCTL_PROC(_sysctl, 3, name2oid,
1252     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE
1253     | CTLFLAG_CAPRW, 0, 0, sysctl_sysctl_name2oid, "I", "");
1254
1255 static int
1256 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
1257 {
1258         struct sysctl_oid *oid;
1259         struct rm_priotracker tracker;
1260         int error;
1261
1262         SYSCTL_RLOCK(&tracker);
1263         error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
1264         if (error)
1265                 goto out;
1266
1267         if (oid->oid_fmt == NULL) {
1268                 error = ENOENT;
1269                 goto out;
1270         }
1271         error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind));
1272         if (error)
1273                 goto out;
1274         error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1);
1275  out:
1276         SYSCTL_RUNLOCK(&tracker);
1277         return (error);
1278 }
1279
1280
1281 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD,
1282     sysctl_sysctl_oidfmt, "");
1283
1284 static int
1285 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS)
1286 {
1287         struct sysctl_oid *oid;
1288         struct rm_priotracker tracker;
1289         int error;
1290
1291         SYSCTL_RLOCK(&tracker);
1292         error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
1293         if (error)
1294                 goto out;
1295
1296         if (oid->oid_descr == NULL) {
1297                 error = ENOENT;
1298                 goto out;
1299         }
1300         error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1);
1301  out:
1302         SYSCTL_RUNLOCK(&tracker);
1303         return (error);
1304 }
1305
1306 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD,
1307     sysctl_sysctl_oiddescr, "");
1308
1309 static int
1310 sysctl_sysctl_oidlabel(SYSCTL_HANDLER_ARGS)
1311 {
1312         struct sysctl_oid *oid;
1313         struct rm_priotracker tracker;
1314         int error;
1315
1316         SYSCTL_RLOCK(&tracker);
1317         error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
1318         if (error)
1319                 goto out;
1320
1321         if (oid->oid_label == NULL) {
1322                 error = ENOENT;
1323                 goto out;
1324         }
1325         error = SYSCTL_OUT(req, oid->oid_label, strlen(oid->oid_label) + 1);
1326  out:
1327         SYSCTL_RUNLOCK(&tracker);
1328         return (error);
1329 }
1330
1331 static SYSCTL_NODE(_sysctl, 6, oidlabel,
1332     CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, sysctl_sysctl_oidlabel, "");
1333
1334 /*
1335  * Default "handler" functions.
1336  */
1337
1338 /*
1339  * Handle a bool.
1340  * Two cases:
1341  *     a variable:  point arg1 at it.
1342  *     a constant:  pass it in arg2.
1343  */
1344
1345 int
1346 sysctl_handle_bool(SYSCTL_HANDLER_ARGS)
1347 {
1348         uint8_t temp;
1349         int error;
1350
1351         /*
1352          * Attempt to get a coherent snapshot by making a copy of the data.
1353          */
1354         if (arg1)
1355                 temp = *(bool *)arg1 ? 1 : 0;
1356         else
1357                 temp = arg2 ? 1 : 0;
1358
1359         error = SYSCTL_OUT(req, &temp, sizeof(temp));
1360         if (error || !req->newptr)
1361                 return (error);
1362
1363         if (!arg1)
1364                 error = EPERM;
1365         else {
1366                 error = SYSCTL_IN(req, &temp, sizeof(temp));
1367                 if (!error)
1368                         *(bool *)arg1 = temp ? 1 : 0;
1369         }
1370         return (error);
1371 }
1372
1373 /*
1374  * Handle an int8_t, signed or unsigned.
1375  * Two cases:
1376  *     a variable:  point arg1 at it.
1377  *     a constant:  pass it in arg2.
1378  */
1379
1380 int
1381 sysctl_handle_8(SYSCTL_HANDLER_ARGS)
1382 {
1383         int8_t tmpout;
1384         int error = 0;
1385
1386         /*
1387          * Attempt to get a coherent snapshot by making a copy of the data.
1388          */
1389         if (arg1)
1390                 tmpout = *(int8_t *)arg1;
1391         else
1392                 tmpout = arg2;
1393         error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout));
1394
1395         if (error || !req->newptr)
1396                 return (error);
1397
1398         if (!arg1)
1399                 error = EPERM;
1400         else
1401                 error = SYSCTL_IN(req, arg1, sizeof(tmpout));
1402         return (error);
1403 }
1404
1405 /*
1406  * Handle an int16_t, signed or unsigned.
1407  * Two cases:
1408  *     a variable:  point arg1 at it.
1409  *     a constant:  pass it in arg2.
1410  */
1411
1412 int
1413 sysctl_handle_16(SYSCTL_HANDLER_ARGS)
1414 {
1415         int16_t tmpout;
1416         int error = 0;
1417
1418         /*
1419          * Attempt to get a coherent snapshot by making a copy of the data.
1420          */
1421         if (arg1)
1422                 tmpout = *(int16_t *)arg1;
1423         else
1424                 tmpout = arg2;
1425         error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout));
1426
1427         if (error || !req->newptr)
1428                 return (error);
1429
1430         if (!arg1)
1431                 error = EPERM;
1432         else
1433                 error = SYSCTL_IN(req, arg1, sizeof(tmpout));
1434         return (error);
1435 }
1436
1437 /*
1438  * Handle an int32_t, signed or unsigned.
1439  * Two cases:
1440  *     a variable:  point arg1 at it.
1441  *     a constant:  pass it in arg2.
1442  */
1443
1444 int
1445 sysctl_handle_32(SYSCTL_HANDLER_ARGS)
1446 {
1447         int32_t tmpout;
1448         int error = 0;
1449
1450         /*
1451          * Attempt to get a coherent snapshot by making a copy of the data.
1452          */
1453         if (arg1)
1454                 tmpout = *(int32_t *)arg1;
1455         else
1456                 tmpout = arg2;
1457         error = SYSCTL_OUT(req, &tmpout, sizeof(tmpout));
1458
1459         if (error || !req->newptr)
1460                 return (error);
1461
1462         if (!arg1)
1463                 error = EPERM;
1464         else
1465                 error = SYSCTL_IN(req, arg1, sizeof(tmpout));
1466         return (error);
1467 }
1468
1469 /*
1470  * Handle an int, signed or unsigned.
1471  * Two cases:
1472  *     a variable:  point arg1 at it.
1473  *     a constant:  pass it in arg2.
1474  */
1475
1476 int
1477 sysctl_handle_int(SYSCTL_HANDLER_ARGS)
1478 {
1479         int tmpout, error = 0;
1480
1481         /*
1482          * Attempt to get a coherent snapshot by making a copy of the data.
1483          */
1484         if (arg1)
1485                 tmpout = *(int *)arg1;
1486         else
1487                 tmpout = arg2;
1488         error = SYSCTL_OUT(req, &tmpout, sizeof(int));
1489
1490         if (error || !req->newptr)
1491                 return (error);
1492
1493         if (!arg1)
1494                 error = EPERM;
1495         else
1496                 error = SYSCTL_IN(req, arg1, sizeof(int));
1497         return (error);
1498 }
1499
1500 /*
1501  * Based on on sysctl_handle_int() convert milliseconds into ticks.
1502  * Note: this is used by TCP.
1503  */
1504
1505 int
1506 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS)
1507 {
1508         int error, s, tt;
1509
1510         tt = *(int *)arg1;
1511         s = (int)((int64_t)tt * 1000 / hz);
1512
1513         error = sysctl_handle_int(oidp, &s, 0, req);
1514         if (error || !req->newptr)
1515                 return (error);
1516
1517         tt = (int)((int64_t)s * hz / 1000);
1518         if (tt < 1)
1519                 return (EINVAL);
1520
1521         *(int *)arg1 = tt;
1522         return (0);
1523 }
1524
1525
1526 /*
1527  * Handle a long, signed or unsigned.
1528  * Two cases:
1529  *     a variable:  point arg1 at it.
1530  *     a constant:  pass it in arg2.
1531  */
1532
1533 int
1534 sysctl_handle_long(SYSCTL_HANDLER_ARGS)
1535 {
1536         int error = 0;
1537         long tmplong;
1538 #ifdef SCTL_MASK32
1539         int tmpint;
1540 #endif
1541
1542         /*
1543          * Attempt to get a coherent snapshot by making a copy of the data.
1544          */
1545         if (arg1)
1546                 tmplong = *(long *)arg1;
1547         else
1548                 tmplong = arg2;
1549 #ifdef SCTL_MASK32
1550         if (req->flags & SCTL_MASK32) {
1551                 tmpint = tmplong;
1552                 error = SYSCTL_OUT(req, &tmpint, sizeof(int));
1553         } else
1554 #endif
1555                 error = SYSCTL_OUT(req, &tmplong, sizeof(long));
1556
1557         if (error || !req->newptr)
1558                 return (error);
1559
1560         if (!arg1)
1561                 error = EPERM;
1562 #ifdef SCTL_MASK32
1563         else if (req->flags & SCTL_MASK32) {
1564                 error = SYSCTL_IN(req, &tmpint, sizeof(int));
1565                 *(long *)arg1 = (long)tmpint;
1566         }
1567 #endif
1568         else
1569                 error = SYSCTL_IN(req, arg1, sizeof(long));
1570         return (error);
1571 }
1572
1573 /*
1574  * Handle a 64 bit int, signed or unsigned.
1575  * Two cases:
1576  *     a variable:  point arg1 at it.
1577  *     a constant:  pass it in arg2.
1578  */
1579 int
1580 sysctl_handle_64(SYSCTL_HANDLER_ARGS)
1581 {
1582         int error = 0;
1583         uint64_t tmpout;
1584
1585         /*
1586          * Attempt to get a coherent snapshot by making a copy of the data.
1587          */
1588         if (arg1)
1589                 tmpout = *(uint64_t *)arg1;
1590         else
1591                 tmpout = arg2;
1592         error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t));
1593
1594         if (error || !req->newptr)
1595                 return (error);
1596
1597         if (!arg1)
1598                 error = EPERM;
1599         else
1600                 error = SYSCTL_IN(req, arg1, sizeof(uint64_t));
1601         return (error);
1602 }
1603
1604 /*
1605  * Handle our generic '\0' terminated 'C' string.
1606  * Two cases:
1607  *      a variable string:  point arg1 at it, arg2 is max length.
1608  *      a constant string:  point arg1 at it, arg2 is zero.
1609  */
1610
1611 int
1612 sysctl_handle_string(SYSCTL_HANDLER_ARGS)
1613 {
1614         size_t outlen;
1615         int error = 0, ro_string = 0;
1616
1617         /*
1618          * A zero-length buffer indicates a fixed size read-only
1619          * string:
1620          */
1621         if (arg2 == 0) {
1622                 arg2 = strlen((char *)arg1) + 1;
1623                 ro_string = 1;
1624         }
1625
1626         if (req->oldptr != NULL) {
1627                 char *tmparg;
1628
1629                 if (ro_string) {
1630                         tmparg = arg1;
1631                 } else {
1632                         /* try to make a coherent snapshot of the string */
1633                         tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK);
1634                         memcpy(tmparg, arg1, arg2);
1635                 }
1636
1637                 outlen = strnlen(tmparg, arg2 - 1) + 1;
1638                 error = SYSCTL_OUT(req, tmparg, outlen);
1639
1640                 if (!ro_string)
1641                         free(tmparg, M_SYSCTLTMP);
1642         } else {
1643                 outlen = strnlen((char *)arg1, arg2 - 1) + 1;
1644                 error = SYSCTL_OUT(req, NULL, outlen);
1645         }
1646         if (error || !req->newptr)
1647                 return (error);
1648
1649         if ((req->newlen - req->newidx) >= arg2) {
1650                 error = EINVAL;
1651         } else {
1652                 arg2 = (req->newlen - req->newidx);
1653                 error = SYSCTL_IN(req, arg1, arg2);
1654                 ((char *)arg1)[arg2] = '\0';
1655         }
1656         return (error);
1657 }
1658
1659 /*
1660  * Handle any kind of opaque data.
1661  * arg1 points to it, arg2 is the size.
1662  */
1663
1664 int
1665 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
1666 {
1667         int error, tries;
1668         u_int generation;
1669         struct sysctl_req req2;
1670
1671         /*
1672          * Attempt to get a coherent snapshot, by using the thread
1673          * pre-emption counter updated from within mi_switch() to
1674          * determine if we were pre-empted during a bcopy() or
1675          * copyout(). Make 3 attempts at doing this before giving up.
1676          * If we encounter an error, stop immediately.
1677          */
1678         tries = 0;
1679         req2 = *req;
1680 retry:
1681         generation = curthread->td_generation;
1682         error = SYSCTL_OUT(req, arg1, arg2);
1683         if (error)
1684                 return (error);
1685         tries++;
1686         if (generation != curthread->td_generation && tries < 3) {
1687                 *req = req2;
1688                 goto retry;
1689         }
1690
1691         error = SYSCTL_IN(req, arg1, arg2);
1692
1693         return (error);
1694 }
1695
1696 /*
1697  * Transfer functions to/from kernel space.
1698  * XXX: rather untested at this point
1699  */
1700 static int
1701 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l)
1702 {
1703         size_t i = 0;
1704
1705         if (req->oldptr) {
1706                 i = l;
1707                 if (req->oldlen <= req->oldidx)
1708                         i = 0;
1709                 else
1710                         if (i > req->oldlen - req->oldidx)
1711                                 i = req->oldlen - req->oldidx;
1712                 if (i > 0)
1713                         bcopy(p, (char *)req->oldptr + req->oldidx, i);
1714         }
1715         req->oldidx += l;
1716         if (req->oldptr && i != l)
1717                 return (ENOMEM);
1718         return (0);
1719 }
1720
1721 static int
1722 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l)
1723 {
1724         if (!req->newptr)
1725                 return (0);
1726         if (req->newlen - req->newidx < l)
1727                 return (EINVAL);
1728         bcopy((char *)req->newptr + req->newidx, p, l);
1729         req->newidx += l;
1730         return (0);
1731 }
1732
1733 int
1734 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old,
1735     size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags)
1736 {
1737         int error = 0;
1738         struct sysctl_req req;
1739
1740         bzero(&req, sizeof req);
1741
1742         req.td = td;
1743         req.flags = flags;
1744
1745         if (oldlenp) {
1746                 req.oldlen = *oldlenp;
1747         }
1748         req.validlen = req.oldlen;
1749
1750         if (old) {
1751                 req.oldptr= old;
1752         }
1753
1754         if (new != NULL) {
1755                 req.newlen = newlen;
1756                 req.newptr = new;
1757         }
1758
1759         req.oldfunc = sysctl_old_kernel;
1760         req.newfunc = sysctl_new_kernel;
1761         req.lock = REQ_UNWIRED;
1762
1763         error = sysctl_root(0, name, namelen, &req);
1764
1765         if (req.lock == REQ_WIRED && req.validlen > 0)
1766                 vsunlock(req.oldptr, req.validlen);
1767
1768         if (error && error != ENOMEM)
1769                 return (error);
1770
1771         if (retval) {
1772                 if (req.oldptr && req.oldidx > req.validlen)
1773                         *retval = req.validlen;
1774                 else
1775                         *retval = req.oldidx;
1776         }
1777         return (error);
1778 }
1779
1780 int
1781 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp,
1782     void *new, size_t newlen, size_t *retval, int flags)
1783 {
1784         int oid[CTL_MAXNAME];
1785         size_t oidlen, plen;
1786         int error;
1787
1788         oid[0] = 0;             /* sysctl internal magic */
1789         oid[1] = 3;             /* name2oid */
1790         oidlen = sizeof(oid);
1791
1792         error = kernel_sysctl(td, oid, 2, oid, &oidlen,
1793             (void *)name, strlen(name), &plen, flags);
1794         if (error)
1795                 return (error);
1796
1797         error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp,
1798             new, newlen, retval, flags);
1799         return (error);
1800 }
1801
1802 /*
1803  * Transfer function to/from user space.
1804  */
1805 static int
1806 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l)
1807 {
1808         size_t i, len, origidx;
1809         int error;
1810
1811         origidx = req->oldidx;
1812         req->oldidx += l;
1813         if (req->oldptr == NULL)
1814                 return (0);
1815         /*
1816          * If we have not wired the user supplied buffer and we are currently
1817          * holding locks, drop a witness warning, as it's possible that
1818          * write operations to the user page can sleep.
1819          */
1820         if (req->lock != REQ_WIRED)
1821                 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1822                     "sysctl_old_user()");
1823         i = l;
1824         len = req->validlen;
1825         if (len <= origidx)
1826                 i = 0;
1827         else {
1828                 if (i > len - origidx)
1829                         i = len - origidx;
1830                 if (req->lock == REQ_WIRED) {
1831                         error = copyout_nofault(p, (char *)req->oldptr +
1832                             origidx, i);
1833                 } else
1834                         error = copyout(p, (char *)req->oldptr + origidx, i);
1835                 if (error != 0)
1836                         return (error);
1837         }
1838         if (i < l)
1839                 return (ENOMEM);
1840         return (0);
1841 }
1842
1843 static int
1844 sysctl_new_user(struct sysctl_req *req, void *p, size_t l)
1845 {
1846         int error;
1847
1848         if (!req->newptr)
1849                 return (0);
1850         if (req->newlen - req->newidx < l)
1851                 return (EINVAL);
1852         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1853             "sysctl_new_user()");
1854         error = copyin((char *)req->newptr + req->newidx, p, l);
1855         req->newidx += l;
1856         return (error);
1857 }
1858
1859 /*
1860  * Wire the user space destination buffer.  If set to a value greater than
1861  * zero, the len parameter limits the maximum amount of wired memory.
1862  */
1863 int
1864 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len)
1865 {
1866         int ret;
1867         size_t wiredlen;
1868
1869         wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen;
1870         ret = 0;
1871         if (req->lock != REQ_WIRED && req->oldptr &&
1872             req->oldfunc == sysctl_old_user) {
1873                 if (wiredlen != 0) {
1874                         ret = vslock(req->oldptr, wiredlen);
1875                         if (ret != 0) {
1876                                 if (ret != ENOMEM)
1877                                         return (ret);
1878                                 wiredlen = 0;
1879                         }
1880                 }
1881                 req->lock = REQ_WIRED;
1882                 req->validlen = wiredlen;
1883         }
1884         return (0);
1885 }
1886
1887 int
1888 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid,
1889     int *nindx, struct sysctl_req *req)
1890 {
1891         struct sysctl_oid_list *lsp;
1892         struct sysctl_oid *oid;
1893         int indx;
1894
1895         SYSCTL_ASSERT_LOCKED();
1896         lsp = &sysctl__children;
1897         indx = 0;
1898         while (indx < CTL_MAXNAME) {
1899                 SLIST_FOREACH(oid, lsp, oid_link) {
1900                         if (oid->oid_number == name[indx])
1901                                 break;
1902                 }
1903                 if (oid == NULL)
1904                         return (ENOENT);
1905
1906                 indx++;
1907                 if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1908                         if (oid->oid_handler != NULL || indx == namelen) {
1909                                 *noid = oid;
1910                                 if (nindx != NULL)
1911                                         *nindx = indx;
1912                                 KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
1913                                     ("%s found DYING node %p", __func__, oid));
1914                                 return (0);
1915                         }
1916                         lsp = SYSCTL_CHILDREN(oid);
1917                 } else if (indx == namelen) {
1918                         if ((oid->oid_kind & CTLFLAG_DORMANT) != 0)
1919                                 return (ENOENT);
1920                         *noid = oid;
1921                         if (nindx != NULL)
1922                                 *nindx = indx;
1923                         KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0,
1924                             ("%s found DYING node %p", __func__, oid));
1925                         return (0);
1926                 } else {
1927                         return (ENOTDIR);
1928                 }
1929         }
1930         return (ENOENT);
1931 }
1932
1933 /*
1934  * Traverse our tree, and find the right node, execute whatever it points
1935  * to, and return the resulting error code.
1936  */
1937
1938 static int
1939 sysctl_root(SYSCTL_HANDLER_ARGS)
1940 {
1941         struct sysctl_oid *oid;
1942         struct rm_priotracker tracker;
1943         int error, indx, lvl;
1944
1945         SYSCTL_RLOCK(&tracker);
1946
1947         error = sysctl_find_oid(arg1, arg2, &oid, &indx, req);
1948         if (error)
1949                 goto out;
1950
1951         if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
1952                 /*
1953                  * You can't call a sysctl when it's a node, but has
1954                  * no handler.  Inform the user that it's a node.
1955                  * The indx may or may not be the same as namelen.
1956                  */
1957                 if (oid->oid_handler == NULL) {
1958                         error = EISDIR;
1959                         goto out;
1960                 }
1961         }
1962
1963         /* Is this sysctl writable? */
1964         if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) {
1965                 error = EPERM;
1966                 goto out;
1967         }
1968
1969         KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL"));
1970
1971 #ifdef CAPABILITY_MODE
1972         /*
1973          * If the process is in capability mode, then don't permit reading or
1974          * writing unless specifically granted for the node.
1975          */
1976         if (IN_CAPABILITY_MODE(req->td)) {
1977                 if ((req->oldptr && !(oid->oid_kind & CTLFLAG_CAPRD)) ||
1978                     (req->newptr && !(oid->oid_kind & CTLFLAG_CAPWR))) {
1979                         error = EPERM;
1980                         goto out;
1981                 }
1982         }
1983 #endif
1984
1985         /* Is this sysctl sensitive to securelevels? */
1986         if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) {
1987                 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE;
1988                 error = securelevel_gt(req->td->td_ucred, lvl);
1989                 if (error)
1990                         goto out;
1991         }
1992
1993         /* Is this sysctl writable by only privileged users? */
1994         if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) {
1995                 int priv;
1996
1997                 if (oid->oid_kind & CTLFLAG_PRISON)
1998                         priv = PRIV_SYSCTL_WRITEJAIL;
1999 #ifdef VIMAGE
2000                 else if ((oid->oid_kind & CTLFLAG_VNET) &&
2001                      prison_owns_vnet(req->td->td_ucred))
2002                         priv = PRIV_SYSCTL_WRITEJAIL;
2003 #endif
2004                 else
2005                         priv = PRIV_SYSCTL_WRITE;
2006                 error = priv_check(req->td, priv);
2007                 if (error)
2008                         goto out;
2009         }
2010
2011         if (!oid->oid_handler) {
2012                 error = EINVAL;
2013                 goto out;
2014         }
2015
2016         if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
2017                 arg1 = (int *)arg1 + indx;
2018                 arg2 -= indx;
2019         } else {
2020                 arg1 = oid->oid_arg1;
2021                 arg2 = oid->oid_arg2;
2022         }
2023 #ifdef MAC
2024         error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2,
2025             req);
2026         if (error != 0)
2027                 goto out;
2028 #endif
2029 #ifdef VIMAGE
2030         if ((oid->oid_kind & CTLFLAG_VNET) && arg1 != NULL)
2031                 arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1);
2032 #endif
2033         error = sysctl_root_handler_locked(oid, arg1, arg2, req, &tracker);
2034
2035 out:
2036         SYSCTL_RUNLOCK(&tracker);
2037         return (error);
2038 }
2039
2040 #ifndef _SYS_SYSPROTO_H_
2041 struct sysctl_args {
2042         int     *name;
2043         u_int   namelen;
2044         void    *old;
2045         size_t  *oldlenp;
2046         void    *new;
2047         size_t  newlen;
2048 };
2049 #endif
2050 int
2051 sys___sysctl(struct thread *td, struct sysctl_args *uap)
2052 {
2053         int error, i, name[CTL_MAXNAME];
2054         size_t j;
2055
2056         if (uap->namelen > CTL_MAXNAME || uap->namelen < 2)
2057                 return (EINVAL);
2058
2059         error = copyin(uap->name, &name, uap->namelen * sizeof(int));
2060         if (error)
2061                 return (error);
2062
2063         error = userland_sysctl(td, name, uap->namelen,
2064                 uap->old, uap->oldlenp, 0,
2065                 uap->new, uap->newlen, &j, 0);
2066         if (error && error != ENOMEM)
2067                 return (error);
2068         if (uap->oldlenp) {
2069                 i = copyout(&j, uap->oldlenp, sizeof(j));
2070                 if (i)
2071                         return (i);
2072         }
2073         return (error);
2074 }
2075
2076 /*
2077  * This is used from various compatibility syscalls too.  That's why name
2078  * must be in kernel space.
2079  */
2080 int
2081 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old,
2082     size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval,
2083     int flags)
2084 {
2085         int error = 0, memlocked;
2086         struct sysctl_req req;
2087
2088         bzero(&req, sizeof req);
2089
2090         req.td = td;
2091         req.flags = flags;
2092
2093         if (oldlenp) {
2094                 if (inkernel) {
2095                         req.oldlen = *oldlenp;
2096                 } else {
2097                         error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp));
2098                         if (error)
2099                                 return (error);
2100                 }
2101         }
2102         req.validlen = req.oldlen;
2103         req.oldptr = old;
2104
2105         if (new != NULL) {
2106                 req.newlen = newlen;
2107                 req.newptr = new;
2108         }
2109
2110         req.oldfunc = sysctl_old_user;
2111         req.newfunc = sysctl_new_user;
2112         req.lock = REQ_UNWIRED;
2113
2114 #ifdef KTRACE
2115         if (KTRPOINT(curthread, KTR_SYSCTL))
2116                 ktrsysctl(name, namelen);
2117 #endif
2118         memlocked = 0;
2119         if (req.oldptr && req.oldlen > 4 * PAGE_SIZE) {
2120                 memlocked = 1;
2121                 sx_xlock(&sysctlmemlock);
2122         }
2123         CURVNET_SET(TD_TO_VNET(td));
2124
2125         for (;;) {
2126                 req.oldidx = 0;
2127                 req.newidx = 0;
2128                 error = sysctl_root(0, name, namelen, &req);
2129                 if (error != EAGAIN)
2130                         break;
2131                 kern_yield(PRI_USER);
2132         }
2133
2134         CURVNET_RESTORE();
2135
2136         if (req.lock == REQ_WIRED && req.validlen > 0)
2137                 vsunlock(req.oldptr, req.validlen);
2138         if (memlocked)
2139                 sx_xunlock(&sysctlmemlock);
2140
2141         if (error && error != ENOMEM)
2142                 return (error);
2143
2144         if (retval) {
2145                 if (req.oldptr && req.oldidx > req.validlen)
2146                         *retval = req.validlen;
2147                 else
2148                         *retval = req.oldidx;
2149         }
2150         return (error);
2151 }
2152
2153 /*
2154  * Drain into a sysctl struct.  The user buffer should be wired if a page
2155  * fault would cause issue.
2156  */
2157 static int
2158 sbuf_sysctl_drain(void *arg, const char *data, int len)
2159 {
2160         struct sysctl_req *req = arg;
2161         int error;
2162
2163         error = SYSCTL_OUT(req, data, len);
2164         KASSERT(error >= 0, ("Got unexpected negative value %d", error));
2165         return (error == 0 ? len : -error);
2166 }
2167
2168 struct sbuf *
2169 sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length,
2170     struct sysctl_req *req)
2171 {
2172
2173         /* Supply a default buffer size if none given. */
2174         if (buf == NULL && length == 0)
2175                 length = 64;
2176         s = sbuf_new(s, buf, length, SBUF_FIXEDLEN | SBUF_INCLUDENUL);
2177         sbuf_set_drain(s, sbuf_sysctl_drain, req);
2178         return (s);
2179 }