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