kern_sysctl.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
    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_compat.h"
   42 #include "opt_mac.h"
   43 
   44 #include <sys/param.h>
   45 #include <sys/systm.h>
   46 #include <sys/kernel.h>
   47 #include <sys/sysctl.h>
   48 #include <sys/malloc.h>
   49 #include <sys/priv.h>
   50 #include <sys/proc.h>
   51 #include <sys/lock.h>
   52 #include <sys/mutex.h>
   53 #include <sys/sx.h>
   54 #include <sys/sysproto.h>
   55 #include <sys/uio.h>
   56 
   57 #include <security/mac/mac_framework.h>
   58 
   59 #include <vm/vm.h>
   60 #include <vm/vm_extern.h>
   61 
   62 static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic");
   63 static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids");
   64 static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer");
   65 
   66 /*
   67  * The sysctllock protects the MIB tree.  It also protects sysctl
   68  * contexts used with dynamic sysctls.  The sysctl_register_oid() and
   69  * sysctl_unregister_oid() routines require the sysctllock to already
   70  * be held, so the sysctl_lock() and sysctl_unlock() routines are
   71  * provided for the few places in the kernel which need to use that
   72  * API rather than using the dynamic API.  Use of the dynamic API is
   73  * strongly encouraged for most code.
   74  *
   75  * This lock is also used to serialize userland sysctl requests.  Some
   76  * sysctls wire user memory, and serializing the requests limits the
   77  * amount of wired user memory in use.
   78  */
   79 static struct sx sysctllock;
   80 
   81 #define SYSCTL_SLOCK()          sx_slock(&sysctllock)
   82 #define SYSCTL_SUNLOCK()        sx_sunlock(&sysctllock)
   83 #define SYSCTL_XLOCK()          sx_xlock(&sysctllock)
   84 #define SYSCTL_XUNLOCK()        sx_xunlock(&sysctllock)
   85 #define SYSCTL_ASSERT_XLOCKED() sx_assert(&sysctllock, SA_XLOCKED)
   86 #define SYSCTL_ASSERT_LOCKED()  sx_assert(&sysctllock, SA_LOCKED)
   87 #define SYSCTL_INIT()           sx_init(&sysctllock, "sysctl lock")
   88 
   89 static int sysctl_root(SYSCTL_HANDLER_ARGS);
   90 
   91 struct sysctl_oid_list sysctl__children; /* root list */
   92 
   93 static int      sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del,
   94                     int recurse);
   95 
   96 static struct sysctl_oid *
   97 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list)
   98 {
   99         struct sysctl_oid *oidp;
  100 
  101         SYSCTL_ASSERT_LOCKED();
  102         SLIST_FOREACH(oidp, list, oid_link) {
  103                 if (strcmp(oidp->oid_name, name) == 0) {
  104                         return (oidp);
  105                 }
  106         }
  107         return (NULL);
  108 }
  109 
  110 /*
  111  * Initialization of the MIB tree.
  112  *
  113  * Order by number in each list.
  114  */
  115 void
  116 sysctl_lock(void)
  117 {
  118 
  119         SYSCTL_XLOCK();
  120 }
  121 
  122 void
  123 sysctl_unlock(void)
  124 {
  125 
  126         SYSCTL_XUNLOCK();
  127 }
  128 
  129 void
  130 sysctl_register_oid(struct sysctl_oid *oidp)
  131 {
  132         struct sysctl_oid_list *parent = oidp->oid_parent;
  133         struct sysctl_oid *p;
  134         struct sysctl_oid *q;
  135 
  136         /*
  137          * First check if another oid with the same name already
  138          * exists in the parent's list.
  139          */
  140         SYSCTL_ASSERT_XLOCKED();
  141         p = sysctl_find_oidname(oidp->oid_name, parent);
  142         if (p != NULL) {
  143                 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
  144                         p->oid_refcnt++;
  145                         return;
  146                 } else {
  147                         printf("can't re-use a leaf (%s)!\n", p->oid_name);
  148                         return;
  149                 }
  150         }
  151         /*
  152          * If this oid has a number OID_AUTO, give it a number which
  153          * is greater than any current oid.
  154          * NOTE: DO NOT change the starting value here, change it in
  155          * <sys/sysctl.h>, and make sure it is at least 256 to
  156          * accomodate e.g. net.inet.raw as a static sysctl node.
  157          */
  158         if (oidp->oid_number == OID_AUTO) {
  159                 static int newoid = CTL_AUTO_START;
  160 
  161                 oidp->oid_number = newoid++;
  162                 if (newoid == 0x7fffffff)
  163                         panic("out of oids");
  164         }
  165 #if 0
  166         else if (oidp->oid_number >= CTL_AUTO_START) {
  167                 /* do not panic; this happens when unregistering sysctl sets */
  168                 printf("static sysctl oid too high: %d", oidp->oid_number);
  169         }
  170 #endif
  171 
  172         /*
  173          * Insert the oid into the parent's list in order.
  174          */
  175         q = NULL;
  176         SLIST_FOREACH(p, parent, oid_link) {
  177                 if (oidp->oid_number < p->oid_number)
  178                         break;
  179                 q = p;
  180         }
  181         if (q)
  182                 SLIST_INSERT_AFTER(q, oidp, oid_link);
  183         else
  184                 SLIST_INSERT_HEAD(parent, oidp, oid_link);
  185 }
  186 
  187 void
  188 sysctl_unregister_oid(struct sysctl_oid *oidp)
  189 {
  190         struct sysctl_oid *p;
  191         int error;
  192 
  193         SYSCTL_ASSERT_XLOCKED();
  194         error = ENOENT;
  195         if (oidp->oid_number == OID_AUTO) {
  196                 error = EINVAL;
  197         } else {
  198                 SLIST_FOREACH(p, oidp->oid_parent, oid_link) {
  199                         if (p == oidp) {
  200                                 SLIST_REMOVE(oidp->oid_parent, oidp,
  201                                     sysctl_oid, oid_link);
  202                                 error = 0;
  203                                 break;
  204                         }
  205                 }
  206         }
  207 
  208         /* 
  209          * This can happen when a module fails to register and is
  210          * being unloaded afterwards.  It should not be a panic()
  211          * for normal use.
  212          */
  213         if (error)
  214                 printf("%s: failed to unregister sysctl\n", __func__);
  215 }
  216 
  217 /* Initialize a new context to keep track of dynamically added sysctls. */
  218 int
  219 sysctl_ctx_init(struct sysctl_ctx_list *c)
  220 {
  221 
  222         if (c == NULL) {
  223                 return (EINVAL);
  224         }
  225 
  226         /*
  227          * No locking here, the caller is responsible for not adding
  228          * new nodes to a context until after this function has
  229          * returned.
  230          */
  231         TAILQ_INIT(c);
  232         return (0);
  233 }
  234 
  235 /* Free the context, and destroy all dynamic oids registered in this context */
  236 int
  237 sysctl_ctx_free(struct sysctl_ctx_list *clist)
  238 {
  239         struct sysctl_ctx_entry *e, *e1;
  240         int error;
  241 
  242         error = 0;
  243         /*
  244          * First perform a "dry run" to check if it's ok to remove oids.
  245          * XXX FIXME
  246          * XXX This algorithm is a hack. But I don't know any
  247          * XXX better solution for now...
  248          */
  249         SYSCTL_XLOCK();
  250         TAILQ_FOREACH(e, clist, link) {
  251                 error = sysctl_remove_oid_locked(e->entry, 0, 0);
  252                 if (error)
  253                         break;
  254         }
  255         /*
  256          * Restore deregistered entries, either from the end,
  257          * or from the place where error occured.
  258          * e contains the entry that was not unregistered
  259          */
  260         if (error)
  261                 e1 = TAILQ_PREV(e, sysctl_ctx_list, link);
  262         else
  263                 e1 = TAILQ_LAST(clist, sysctl_ctx_list);
  264         while (e1 != NULL) {
  265                 sysctl_register_oid(e1->entry);
  266                 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link);
  267         }
  268         if (error) {
  269                 SYSCTL_XUNLOCK();
  270                 return(EBUSY);
  271         }
  272         /* Now really delete the entries */
  273         e = TAILQ_FIRST(clist);
  274         while (e != NULL) {
  275                 e1 = TAILQ_NEXT(e, link);
  276                 error = sysctl_remove_oid_locked(e->entry, 1, 0);
  277                 if (error)
  278                         panic("sysctl_remove_oid: corrupt tree, entry: %s",
  279                             e->entry->oid_name);
  280                 free(e, M_SYSCTLOID);
  281                 e = e1;
  282         }
  283         SYSCTL_XUNLOCK();
  284         return (error);
  285 }
  286 
  287 /* Add an entry to the context */
  288 struct sysctl_ctx_entry *
  289 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
  290 {
  291         struct sysctl_ctx_entry *e;
  292 
  293         SYSCTL_ASSERT_XLOCKED();
  294         if (clist == NULL || oidp == NULL)
  295                 return(NULL);
  296         e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK);
  297         e->entry = oidp;
  298         TAILQ_INSERT_HEAD(clist, e, link);
  299         return (e);
  300 }
  301 
  302 /* Find an entry in the context */
  303 struct sysctl_ctx_entry *
  304 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
  305 {
  306         struct sysctl_ctx_entry *e;
  307 
  308         SYSCTL_ASSERT_LOCKED();
  309         if (clist == NULL || oidp == NULL)
  310                 return(NULL);
  311         TAILQ_FOREACH(e, clist, link) {
  312                 if(e->entry == oidp)
  313                         return(e);
  314         }
  315         return (e);
  316 }
  317 
  318 /*
  319  * Delete an entry from the context.
  320  * NOTE: this function doesn't free oidp! You have to remove it
  321  * with sysctl_remove_oid().
  322  */
  323 int
  324 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
  325 {
  326         struct sysctl_ctx_entry *e;
  327 
  328         if (clist == NULL || oidp == NULL)
  329                 return (EINVAL);
  330         SYSCTL_XLOCK();
  331         e = sysctl_ctx_entry_find(clist, oidp);
  332         if (e != NULL) {
  333                 TAILQ_REMOVE(clist, e, link);
  334                 SYSCTL_XUNLOCK();
  335                 free(e, M_SYSCTLOID);
  336                 return (0);
  337         } else {
  338                 SYSCTL_XUNLOCK();
  339                 return (ENOENT);
  340         }
  341 }
  342 
  343 /*
  344  * Remove dynamically created sysctl trees.
  345  * oidp - top of the tree to be removed
  346  * del - if 0 - just deregister, otherwise free up entries as well
  347  * recurse - if != 0 traverse the subtree to be deleted
  348  */
  349 int
  350 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse)
  351 {
  352         int error;
  353 
  354         SYSCTL_XLOCK();
  355         error = sysctl_remove_oid_locked(oidp, del, recurse);
  356         SYSCTL_XUNLOCK();
  357         return (error);
  358 }
  359 
  360 static int
  361 sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse)
  362 {
  363         struct sysctl_oid *p;
  364         int error;
  365 
  366         SYSCTL_ASSERT_XLOCKED();
  367         if (oidp == NULL)
  368                 return(EINVAL);
  369         if ((oidp->oid_kind & CTLFLAG_DYN) == 0) {
  370                 printf("can't remove non-dynamic nodes!\n");
  371                 return (EINVAL);
  372         }
  373         /*
  374          * WARNING: normal method to do this should be through
  375          * sysctl_ctx_free(). Use recursing as the last resort
  376          * method to purge your sysctl tree of leftovers...
  377          * However, if some other code still references these nodes,
  378          * it will panic.
  379          */
  380         if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
  381                 if (oidp->oid_refcnt == 1) {
  382                         SLIST_FOREACH(p, SYSCTL_CHILDREN(oidp), oid_link) {
  383                                 if (!recurse)
  384                                         return (ENOTEMPTY);
  385                                 error = sysctl_remove_oid_locked(p, del,
  386                                     recurse);
  387                                 if (error)
  388                                         return (error);
  389                         }
  390                         if (del)
  391                                 free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID);
  392                 }
  393         }
  394         if (oidp->oid_refcnt > 1 ) {
  395                 oidp->oid_refcnt--;
  396         } else {
  397                 if (oidp->oid_refcnt == 0) {
  398                         printf("Warning: bad oid_refcnt=%u (%s)!\n",
  399                                 oidp->oid_refcnt, oidp->oid_name);
  400                         return (EINVAL);
  401                 }
  402                 sysctl_unregister_oid(oidp);
  403                 if (del) {
  404                         if (oidp->oid_descr)
  405                                 free((void *)(uintptr_t)(const void *)oidp->oid_descr, M_SYSCTLOID);
  406                         free((void *)(uintptr_t)(const void *)oidp->oid_name,
  407                              M_SYSCTLOID);
  408                         free(oidp, M_SYSCTLOID);
  409                 }
  410         }
  411         return (0);
  412 }
  413 
  414 /*
  415  * Create new sysctls at run time.
  416  * clist may point to a valid context initialized with sysctl_ctx_init().
  417  */
  418 struct sysctl_oid *
  419 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent,
  420         int number, const char *name, int kind, void *arg1, int arg2,
  421         int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr)
  422 {
  423         struct sysctl_oid *oidp;
  424         ssize_t len;
  425         char *newname;
  426 
  427         /* You have to hook up somewhere.. */
  428         if (parent == NULL)
  429                 return(NULL);
  430         /* Check if the node already exists, otherwise create it */
  431         SYSCTL_XLOCK();
  432         oidp = sysctl_find_oidname(name, parent);
  433         if (oidp != NULL) {
  434                 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
  435                         oidp->oid_refcnt++;
  436                         /* Update the context */
  437                         if (clist != NULL)
  438                                 sysctl_ctx_entry_add(clist, oidp);
  439                         SYSCTL_XUNLOCK();
  440                         return (oidp);
  441                 } else {
  442                         SYSCTL_XUNLOCK();
  443                         printf("can't re-use a leaf (%s)!\n", name);
  444                         return (NULL);
  445                 }
  446         }
  447         oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO);
  448         oidp->oid_parent = parent;
  449         SLIST_NEXT(oidp, oid_link) = NULL;
  450         oidp->oid_number = number;
  451         oidp->oid_refcnt = 1;
  452         len = strlen(name);
  453         newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK);
  454         bcopy(name, newname, len + 1);
  455         newname[len] = '\0';
  456         oidp->oid_name = newname;
  457         oidp->oid_handler = handler;
  458         oidp->oid_kind = CTLFLAG_DYN | kind;
  459         if ((kind & CTLTYPE) == CTLTYPE_NODE) {
  460                 /* Allocate space for children */
  461                 SYSCTL_CHILDREN_SET(oidp, malloc(sizeof(struct sysctl_oid_list),
  462                     M_SYSCTLOID, M_WAITOK));
  463                 SLIST_INIT(SYSCTL_CHILDREN(oidp));
  464         } else {
  465                 oidp->oid_arg1 = arg1;
  466                 oidp->oid_arg2 = arg2;
  467         }
  468         oidp->oid_fmt = fmt;
  469         if (descr) {
  470                 int len = strlen(descr) + 1;
  471                 oidp->oid_descr = malloc(len, M_SYSCTLOID, M_WAITOK);
  472                 if (oidp->oid_descr)
  473                         strcpy((char *)(uintptr_t)(const void *)oidp->oid_descr, descr);
  474         }
  475         /* Update the context, if used */
  476         if (clist != NULL)
  477                 sysctl_ctx_entry_add(clist, oidp);
  478         /* Register this oid */
  479         sysctl_register_oid(oidp);
  480         SYSCTL_XUNLOCK();
  481         return (oidp);
  482 }
  483 
  484 /*
  485  * Rename an existing oid.
  486  */
  487 void
  488 sysctl_rename_oid(struct sysctl_oid *oidp, const char *name)
  489 {
  490         ssize_t len;
  491         char *newname;
  492         void *oldname;
  493 
  494         len = strlen(name);
  495         newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK);
  496         bcopy(name, newname, len + 1);
  497         newname[len] = '\0';
  498         SYSCTL_XLOCK();
  499         oldname = (void *)(uintptr_t)(const void *)oidp->oid_name;
  500         oidp->oid_name = newname;
  501         SYSCTL_XUNLOCK();
  502         free(oldname, M_SYSCTLOID);
  503 }
  504 
  505 /*
  506  * Reparent an existing oid.
  507  */
  508 int
  509 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent)
  510 {
  511         struct sysctl_oid *oidp;
  512 
  513         SYSCTL_XLOCK();
  514         if (oid->oid_parent == parent) {
  515                 SYSCTL_XUNLOCK();
  516                 return (0);
  517         }
  518         oidp = sysctl_find_oidname(oid->oid_name, parent);
  519         if (oidp != NULL) {
  520                 SYSCTL_XUNLOCK();
  521                 return (EEXIST);
  522         }
  523         sysctl_unregister_oid(oid);
  524         oid->oid_parent = parent;
  525         oid->oid_number = OID_AUTO;
  526         sysctl_register_oid(oid);
  527         SYSCTL_XUNLOCK();
  528         return (0);
  529 }
  530 
  531 /*
  532  * Register the kernel's oids on startup.
  533  */
  534 SET_DECLARE(sysctl_set, struct sysctl_oid);
  535 
  536 static void
  537 sysctl_register_all(void *arg)
  538 {
  539         struct sysctl_oid **oidp;
  540 
  541         SYSCTL_INIT();
  542         SYSCTL_XLOCK();
  543         SET_FOREACH(oidp, sysctl_set)
  544                 sysctl_register_oid(*oidp);
  545         SYSCTL_XUNLOCK();
  546 }
  547 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0);
  548 
  549 /*
  550  * "Staff-functions"
  551  *
  552  * These functions implement a presently undocumented interface 
  553  * used by the sysctl program to walk the tree, and get the type
  554  * so it can print the value.
  555  * This interface is under work and consideration, and should probably
  556  * be killed with a big axe by the first person who can find the time.
  557  * (be aware though, that the proper interface isn't as obvious as it
  558  * may seem, there are various conflicting requirements.
  559  *
  560  * {0,0}        printf the entire MIB-tree.
  561  * {0,1,...}    return the name of the "..." OID.
  562  * {0,2,...}    return the next OID.
  563  * {0,3}        return the OID of the name in "new"
  564  * {0,4,...}    return the kind & format info for the "..." OID.
  565  * {0,5,...}    return the description the "..." OID.
  566  */
  567 
  568 #ifdef SYSCTL_DEBUG
  569 static void
  570 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i)
  571 {
  572         int k;
  573         struct sysctl_oid *oidp;
  574 
  575         SYSCTL_ASSERT_LOCKED();
  576         SLIST_FOREACH(oidp, l, oid_link) {
  577 
  578                 for (k=0; k<i; k++)
  579                         printf(" ");
  580 
  581                 printf("%d %s ", oidp->oid_number, oidp->oid_name);
  582 
  583                 printf("%c%c",
  584                         oidp->oid_kind & CTLFLAG_RD ? 'R':' ',
  585                         oidp->oid_kind & CTLFLAG_WR ? 'W':' ');
  586 
  587                 if (oidp->oid_handler)
  588                         printf(" *Handler");
  589 
  590                 switch (oidp->oid_kind & CTLTYPE) {
  591                         case CTLTYPE_NODE:
  592                                 printf(" Node\n");
  593                                 if (!oidp->oid_handler) {
  594                                         sysctl_sysctl_debug_dump_node(
  595                                                 oidp->oid_arg1, i+2);
  596                                 }
  597                                 break;
  598                         case CTLTYPE_INT:    printf(" Int\n"); break;
  599                         case CTLTYPE_STRING: printf(" String\n"); break;
  600                         case CTLTYPE_QUAD:   printf(" Quad\n"); break;
  601                         case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break;
  602                         default:             printf("\n");
  603                 }
  604 
  605         }
  606 }
  607 
  608 static int
  609 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS)
  610 {
  611         int error;
  612 
  613         error = priv_check(req->td, PRIV_SYSCTL_DEBUG);
  614         if (error)
  615                 return (error);
  616         sysctl_sysctl_debug_dump_node(&sysctl__children, 0);
  617         return (ENOENT);
  618 }
  619 
  620 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD,
  621         0, 0, sysctl_sysctl_debug, "-", "");
  622 #endif
  623 
  624 static int
  625 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS)
  626 {
  627         int *name = (int *) arg1;
  628         u_int namelen = arg2;
  629         int error = 0;
  630         struct sysctl_oid *oid;
  631         struct sysctl_oid_list *lsp = &sysctl__children, *lsp2;
  632         char buf[10];
  633 
  634         SYSCTL_ASSERT_LOCKED();
  635         while (namelen) {
  636                 if (!lsp) {
  637                         snprintf(buf,sizeof(buf),"%d",*name);
  638                         if (req->oldidx)
  639                                 error = SYSCTL_OUT(req, ".", 1);
  640                         if (!error)
  641                                 error = SYSCTL_OUT(req, buf, strlen(buf));
  642                         if (error)
  643                                 return (error);
  644                         namelen--;
  645                         name++;
  646                         continue;
  647                 }
  648                 lsp2 = 0;
  649                 SLIST_FOREACH(oid, lsp, oid_link) {
  650                         if (oid->oid_number != *name)
  651                                 continue;
  652 
  653                         if (req->oldidx)
  654                                 error = SYSCTL_OUT(req, ".", 1);
  655                         if (!error)
  656                                 error = SYSCTL_OUT(req, oid->oid_name,
  657                                         strlen(oid->oid_name));
  658                         if (error)
  659                                 return (error);
  660 
  661                         namelen--;
  662                         name++;
  663 
  664                         if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 
  665                                 break;
  666 
  667                         if (oid->oid_handler)
  668                                 break;
  669 
  670                         lsp2 = (struct sysctl_oid_list *)oid->oid_arg1;
  671                         break;
  672                 }
  673                 lsp = lsp2;
  674         }
  675         return (SYSCTL_OUT(req, "", 1));
  676 }
  677 
  678 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, "");
  679 
  680 static int
  681 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 
  682         int *next, int *len, int level, struct sysctl_oid **oidpp)
  683 {
  684         struct sysctl_oid *oidp;
  685 
  686         SYSCTL_ASSERT_LOCKED();
  687         *len = level;
  688         SLIST_FOREACH(oidp, lsp, oid_link) {
  689                 *next = oidp->oid_number;
  690                 *oidpp = oidp;
  691 
  692                 if (oidp->oid_kind & CTLFLAG_SKIP)
  693                         continue;
  694 
  695                 if (!namelen) {
  696                         if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 
  697                                 return (0);
  698                         if (oidp->oid_handler) 
  699                                 /* We really should call the handler here...*/
  700                                 return (0);
  701                         lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
  702                         if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 
  703                                 len, level+1, oidpp))
  704                                 return (0);
  705                         goto emptynode;
  706                 }
  707 
  708                 if (oidp->oid_number < *name)
  709                         continue;
  710 
  711                 if (oidp->oid_number > *name) {
  712                         if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
  713                                 return (0);
  714                         if (oidp->oid_handler)
  715                                 return (0);
  716                         lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
  717                         if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 
  718                                 next+1, len, level+1, oidpp))
  719                                 return (0);
  720                         goto next;
  721                 }
  722                 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
  723                         continue;
  724 
  725                 if (oidp->oid_handler)
  726                         continue;
  727 
  728                 lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
  729                 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 
  730                         len, level+1, oidpp))
  731                         return (0);
  732         next:
  733                 namelen = 1;
  734         emptynode:
  735                 *len = level;
  736         }
  737         return (1);
  738 }
  739 
  740 static int
  741 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS)
  742 {
  743         int *name = (int *) arg1;
  744         u_int namelen = arg2;
  745         int i, j, error;
  746         struct sysctl_oid *oid;
  747         struct sysctl_oid_list *lsp = &sysctl__children;
  748         int newoid[CTL_MAXNAME];
  749 
  750         i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid);
  751         if (i)
  752                 return (ENOENT);
  753         error = SYSCTL_OUT(req, newoid, j * sizeof (int));
  754         return (error);
  755 }
  756 
  757 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, "");
  758 
  759 static int
  760 name2oid (char *name, int *oid, int *len, struct sysctl_oid **oidpp)
  761 {
  762         int i;
  763         struct sysctl_oid *oidp;
  764         struct sysctl_oid_list *lsp = &sysctl__children;
  765         char *p;
  766 
  767         SYSCTL_ASSERT_LOCKED();
  768 
  769         if (!*name)
  770                 return (ENOENT);
  771 
  772         p = name + strlen(name) - 1 ;
  773         if (*p == '.')
  774                 *p = '\0';
  775 
  776         *len = 0;
  777 
  778         for (p = name; *p && *p != '.'; p++) 
  779                 ;
  780         i = *p;
  781         if (i == '.')
  782                 *p = '\0';
  783 
  784         oidp = SLIST_FIRST(lsp);
  785 
  786         while (oidp && *len < CTL_MAXNAME) {
  787                 if (strcmp(name, oidp->oid_name)) {
  788                         oidp = SLIST_NEXT(oidp, oid_link);
  789                         continue;
  790                 }
  791                 *oid++ = oidp->oid_number;
  792                 (*len)++;
  793 
  794                 if (!i) {
  795                         if (oidpp)
  796                                 *oidpp = oidp;
  797                         return (0);
  798                 }
  799 
  800                 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
  801                         break;
  802 
  803                 if (oidp->oid_handler)
  804                         break;
  805 
  806                 lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
  807                 oidp = SLIST_FIRST(lsp);
  808                 name = p+1;
  809                 for (p = name; *p && *p != '.'; p++) 
  810                                 ;
  811                 i = *p;
  812                 if (i == '.')
  813                         *p = '\0';
  814         }
  815         return (ENOENT);
  816 }
  817 
  818 static int
  819 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
  820 {
  821         char *p;
  822         int error, oid[CTL_MAXNAME], len;
  823         struct sysctl_oid *op = 0;
  824 
  825         SYSCTL_ASSERT_LOCKED();
  826 
  827         if (!req->newlen) 
  828                 return (ENOENT);
  829         if (req->newlen >= MAXPATHLEN)  /* XXX arbitrary, undocumented */
  830                 return (ENAMETOOLONG);
  831 
  832         p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK);
  833 
  834         error = SYSCTL_IN(req, p, req->newlen);
  835         if (error) {
  836                 free(p, M_SYSCTL);
  837                 return (error);
  838         }
  839 
  840         p [req->newlen] = '\0';
  841 
  842         error = name2oid(p, oid, &len, &op);
  843 
  844         free(p, M_SYSCTL);
  845 
  846         if (error)
  847                 return (error);
  848 
  849         error = SYSCTL_OUT(req, oid, len * sizeof *oid);
  850         return (error);
  851 }
  852 
  853 SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_MPSAFE,
  854     0, 0, sysctl_sysctl_name2oid, "I", "");
  855 
  856 static int
  857 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
  858 {
  859         struct sysctl_oid *oid;
  860         int error;
  861 
  862         error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
  863         if (error)
  864                 return (error);
  865 
  866         if (!oid->oid_fmt)
  867                 return (ENOENT);
  868         error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind));
  869         if (error)
  870                 return (error);
  871         error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1);
  872         return (error);
  873 }
  874 
  875 
  876 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE,
  877     sysctl_sysctl_oidfmt, "");
  878 
  879 static int
  880 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS)
  881 {
  882         struct sysctl_oid *oid;
  883         int error;
  884 
  885         error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
  886         if (error)
  887                 return (error);
  888 
  889         if (!oid->oid_descr)
  890                 return (ENOENT);
  891         error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1);
  892         return (error);
  893 }
  894 
  895 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD, sysctl_sysctl_oiddescr, "");
  896 
  897 /*
  898  * Default "handler" functions.
  899  */
  900 
  901 /*
  902  * Handle an int, signed or unsigned.
  903  * Two cases:
  904  *     a variable:  point arg1 at it.
  905  *     a constant:  pass it in arg2.
  906  */
  907 
  908 int
  909 sysctl_handle_int(SYSCTL_HANDLER_ARGS)
  910 {
  911         int tmpout, error = 0;
  912 
  913         /*
  914          * Attempt to get a coherent snapshot by making a copy of the data.
  915          */
  916         if (arg1)
  917                 tmpout = *(int *)arg1;
  918         else
  919                 tmpout = arg2;
  920         error = SYSCTL_OUT(req, &tmpout, sizeof(int));
  921 
  922         if (error || !req->newptr)
  923                 return (error);
  924 
  925         if (!arg1)
  926                 error = EPERM;
  927         else
  928                 error = SYSCTL_IN(req, arg1, sizeof(int));
  929         return (error);
  930 }
  931 
  932 
  933 /*
  934  * Based on on sysctl_handle_int() convert milliseconds into ticks.
  935  */
  936 
  937 int
  938 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS)
  939 {
  940         int error, s, tt;
  941 
  942         tt = *(int *)oidp->oid_arg1;
  943         s = (int)((int64_t)tt * 1000 / hz);
  944 
  945         error = sysctl_handle_int(oidp, &s, 0, req);
  946         if (error || !req->newptr)
  947                 return (error);
  948 
  949         tt = (int)((int64_t)s * hz / 1000);
  950         if (tt < 1)
  951                 return (EINVAL);
  952 
  953         *(int *)oidp->oid_arg1 = tt;
  954         return (0);
  955 }
  956 
  957 
  958 /*
  959  * Handle a long, signed or unsigned.  arg1 points to it.
  960  */
  961 
  962 int
  963 sysctl_handle_long(SYSCTL_HANDLER_ARGS)
  964 {
  965         int error = 0;
  966         long tmplong;
  967 #ifdef SCTL_MASK32
  968         int tmpint;
  969 #endif
  970 
  971         /*
  972          * Attempt to get a coherent snapshot by making a copy of the data.
  973          */
  974         if (!arg1)
  975                 return (EINVAL);
  976         tmplong = *(long *)arg1;
  977 #ifdef SCTL_MASK32
  978         if (req->flags & SCTL_MASK32) {
  979                 tmpint = tmplong;
  980                 error = SYSCTL_OUT(req, &tmpint, sizeof(int));
  981         } else
  982 #endif
  983                 error = SYSCTL_OUT(req, &tmplong, sizeof(long));
  984 
  985         if (error || !req->newptr)
  986                 return (error);
  987 
  988 #ifdef SCTL_MASK32
  989         if (req->flags & SCTL_MASK32) {
  990                 error = SYSCTL_IN(req, &tmpint, sizeof(int));
  991                 *(long *)arg1 = (long)tmpint;
  992         } else
  993 #endif
  994                 error = SYSCTL_IN(req, arg1, sizeof(long));
  995         return (error);
  996 }
  997 
  998 /*
  999  * Handle a 64 bit int, signed or unsigned.  arg1 points to it.
 1000  */
 1001 
 1002 int
 1003 sysctl_handle_quad(SYSCTL_HANDLER_ARGS)
 1004 {
 1005         int error = 0;
 1006         uint64_t tmpout;
 1007 
 1008         /*
 1009          * Attempt to get a coherent snapshot by making a copy of the data.
 1010          */
 1011         if (!arg1)
 1012                 return (EINVAL);
 1013         tmpout = *(uint64_t *)arg1;
 1014         error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t));
 1015 
 1016         if (error || !req->newptr)
 1017                 return (error);
 1018 
 1019         error = SYSCTL_IN(req, arg1, sizeof(uint64_t));
 1020         return (error);
 1021 }
 1022 
 1023 /*
 1024  * Handle our generic '\0' terminated 'C' string.
 1025  * Two cases:
 1026  *      a variable string:  point arg1 at it, arg2 is max length.
 1027  *      a constant string:  point arg1 at it, arg2 is zero.
 1028  */
 1029 
 1030 int
 1031 sysctl_handle_string(SYSCTL_HANDLER_ARGS)
 1032 {
 1033         int error=0;
 1034         char *tmparg;
 1035         size_t outlen;
 1036 
 1037         /*
 1038          * Attempt to get a coherent snapshot by copying to a
 1039          * temporary kernel buffer.
 1040          */
 1041 retry:
 1042         outlen = strlen((char *)arg1)+1;
 1043         tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK);
 1044 
 1045         if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) {
 1046                 free(tmparg, M_SYSCTLTMP);
 1047                 goto retry;
 1048         }
 1049 
 1050         error = SYSCTL_OUT(req, tmparg, outlen);
 1051         free(tmparg, M_SYSCTLTMP);
 1052 
 1053         if (error || !req->newptr)
 1054                 return (error);
 1055 
 1056         if ((req->newlen - req->newidx) >= arg2) {
 1057                 error = EINVAL;
 1058         } else {
 1059                 arg2 = (req->newlen - req->newidx);
 1060                 error = SYSCTL_IN(req, arg1, arg2);
 1061                 ((char *)arg1)[arg2] = '\0';
 1062         }
 1063 
 1064         return (error);
 1065 }
 1066 
 1067 /*
 1068  * Handle any kind of opaque data.
 1069  * arg1 points to it, arg2 is the size.
 1070  */
 1071 
 1072 int
 1073 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
 1074 {
 1075         int error, tries;
 1076         u_int generation;
 1077         struct sysctl_req req2;
 1078 
 1079         /*
 1080          * Attempt to get a coherent snapshot, by using the thread
 1081          * pre-emption counter updated from within mi_switch() to
 1082          * determine if we were pre-empted during a bcopy() or
 1083          * copyout(). Make 3 attempts at doing this before giving up.
 1084          * If we encounter an error, stop immediately.
 1085          */
 1086         tries = 0;
 1087         req2 = *req;
 1088 retry:
 1089         generation = curthread->td_generation;
 1090         error = SYSCTL_OUT(req, arg1, arg2);
 1091         if (error)
 1092                 return (error);
 1093         tries++;
 1094         if (generation != curthread->td_generation && tries < 3) {
 1095                 *req = req2;
 1096                 goto retry;
 1097         }
 1098 
 1099         error = SYSCTL_IN(req, arg1, arg2);
 1100 
 1101         return (error);
 1102 }
 1103 
 1104 /*
 1105  * Transfer functions to/from kernel space.
 1106  * XXX: rather untested at this point
 1107  */
 1108 static int
 1109 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l)
 1110 {
 1111         size_t i = 0;
 1112 
 1113         if (req->oldptr) {
 1114                 i = l;
 1115                 if (req->oldlen <= req->oldidx)
 1116                         i = 0;
 1117                 else
 1118                         if (i > req->oldlen - req->oldidx)
 1119                                 i = req->oldlen - req->oldidx;
 1120                 if (i > 0)
 1121                         bcopy(p, (char *)req->oldptr + req->oldidx, i);
 1122         }
 1123         req->oldidx += l;
 1124         if (req->oldptr && i != l)
 1125                 return (ENOMEM);
 1126         return (0);
 1127 }
 1128 
 1129 static int
 1130 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l)
 1131 {
 1132         if (!req->newptr)
 1133                 return (0);
 1134         if (req->newlen - req->newidx < l)
 1135                 return (EINVAL);
 1136         bcopy((char *)req->newptr + req->newidx, p, l);
 1137         req->newidx += l;
 1138         return (0);
 1139 }
 1140 
 1141 int
 1142 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old,
 1143     size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags)
 1144 {
 1145         int error = 0;
 1146         struct sysctl_req req;
 1147 
 1148         bzero(&req, sizeof req);
 1149 
 1150         req.td = td;
 1151         req.flags = flags;
 1152 
 1153         if (oldlenp) {
 1154                 req.oldlen = *oldlenp;
 1155         }
 1156         req.validlen = req.oldlen;
 1157 
 1158         if (old) {
 1159                 req.oldptr= old;
 1160         }
 1161 
 1162         if (new != NULL) {
 1163                 req.newlen = newlen;
 1164                 req.newptr = new;
 1165         }
 1166 
 1167         req.oldfunc = sysctl_old_kernel;
 1168         req.newfunc = sysctl_new_kernel;
 1169         req.lock = REQ_LOCKED;
 1170 
 1171         SYSCTL_SLOCK();
 1172         error = sysctl_root(0, name, namelen, &req);
 1173         SYSCTL_SUNLOCK();
 1174 
 1175         if (req.lock == REQ_WIRED && req.validlen > 0)
 1176                 vsunlock(req.oldptr, req.validlen);
 1177 
 1178         if (error && error != ENOMEM)
 1179                 return (error);
 1180 
 1181         if (retval) {
 1182                 if (req.oldptr && req.oldidx > req.validlen)
 1183                         *retval = req.validlen;
 1184                 else
 1185                         *retval = req.oldidx;
 1186         }
 1187         return (error);
 1188 }
 1189 
 1190 int
 1191 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp,
 1192     void *new, size_t newlen, size_t *retval, int flags)
 1193 {
 1194         int oid[CTL_MAXNAME];
 1195         size_t oidlen, plen;
 1196         int error;
 1197 
 1198         oid[0] = 0;             /* sysctl internal magic */
 1199         oid[1] = 3;             /* name2oid */
 1200         oidlen = sizeof(oid);
 1201 
 1202         error = kernel_sysctl(td, oid, 2, oid, &oidlen,
 1203             (void *)name, strlen(name), &plen, flags);
 1204         if (error)
 1205                 return (error);
 1206 
 1207         error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp,
 1208             new, newlen, retval, flags);
 1209         return (error);
 1210 }
 1211 
 1212 /*
 1213  * Transfer function to/from user space.
 1214  */
 1215 static int
 1216 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l)
 1217 {
 1218         int error = 0;
 1219         size_t i, len, origidx;
 1220 
 1221         origidx = req->oldidx;
 1222         req->oldidx += l;
 1223         if (req->oldptr == NULL)
 1224                 return (0);
 1225         /*
 1226          * If we have not wired the user supplied buffer and we are currently
 1227          * holding locks, drop a witness warning, as it's possible that
 1228          * write operations to the user page can sleep.
 1229          */
 1230         if (req->lock != REQ_WIRED)
 1231                 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
 1232                     "sysctl_old_user()");
 1233         i = l;
 1234         len = req->validlen;
 1235         if (len <= origidx)
 1236                 i = 0;
 1237         else {
 1238                 if (i > len - origidx)
 1239                         i = len - origidx;
 1240                 error = copyout(p, (char *)req->oldptr + origidx, i);
 1241         }
 1242         if (error)
 1243                 return (error);
 1244         if (i < l)
 1245                 return (ENOMEM);
 1246         return (0);
 1247 }
 1248 
 1249 static int
 1250 sysctl_new_user(struct sysctl_req *req, void *p, size_t l)
 1251 {
 1252         int error;
 1253 
 1254         if (!req->newptr)
 1255                 return (0);
 1256         if (req->newlen - req->newidx < l)
 1257                 return (EINVAL);
 1258         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
 1259             "sysctl_new_user()");
 1260         error = copyin((char *)req->newptr + req->newidx, p, l);
 1261         req->newidx += l;
 1262         return (error);
 1263 }
 1264 
 1265 /*
 1266  * Wire the user space destination buffer.  If set to a value greater than
 1267  * zero, the len parameter limits the maximum amount of wired memory.
 1268  */
 1269 int
 1270 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len)
 1271 {
 1272         int ret;
 1273         size_t i, wiredlen;
 1274         char *cp, dummy;
 1275 
 1276         wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen;
 1277         ret = 0;
 1278         if (req->lock == REQ_LOCKED && req->oldptr &&
 1279             req->oldfunc == sysctl_old_user) {
 1280                 if (wiredlen != 0) {
 1281                         ret = vslock(req->oldptr, wiredlen);
 1282                         if (ret != 0) {
 1283                                 if (ret != ENOMEM)
 1284                                         return (ret);
 1285                                 wiredlen = 0;
 1286                         }
 1287                         /*
 1288                          * Touch all the wired pages to avoid PTE modified
 1289                          * bit emulation traps on Alpha while holding locks
 1290                          * in the sysctl handler.
 1291                          */
 1292                         for (i = (wiredlen + PAGE_SIZE - 1) / PAGE_SIZE,
 1293                             cp = req->oldptr; i > 0; i--, cp += PAGE_SIZE) {
 1294                                 copyin(cp, &dummy, 1);
 1295                                 copyout(&dummy, cp, 1);
 1296                         }
 1297                 }
 1298                 req->lock = REQ_WIRED;
 1299                 req->validlen = wiredlen;
 1300         }
 1301         return (0);
 1302 }
 1303 
 1304 int
 1305 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid,
 1306     int *nindx, struct sysctl_req *req)
 1307 {
 1308         struct sysctl_oid *oid;
 1309         int indx;
 1310 
 1311         SYSCTL_ASSERT_LOCKED();
 1312         oid = SLIST_FIRST(&sysctl__children);
 1313         indx = 0;
 1314         while (oid && indx < CTL_MAXNAME) {
 1315                 if (oid->oid_number == name[indx]) {
 1316                         indx++;
 1317                         if (oid->oid_kind & CTLFLAG_NOLOCK)
 1318                                 req->lock = REQ_UNLOCKED;
 1319                         if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
 1320                                 if (oid->oid_handler != NULL ||
 1321                                     indx == namelen) {
 1322                                         *noid = oid;
 1323                                         if (nindx != NULL)
 1324                                                 *nindx = indx;
 1325                                         return (0);
 1326                                 }
 1327                                 oid = SLIST_FIRST(
 1328                                     (struct sysctl_oid_list *)oid->oid_arg1);
 1329                         } else if (indx == namelen) {
 1330                                 *noid = oid;
 1331                                 if (nindx != NULL)
 1332                                         *nindx = indx;
 1333                                 return (0);
 1334                         } else {
 1335                                 return (ENOTDIR);
 1336                         }
 1337                 } else {
 1338                         oid = SLIST_NEXT(oid, oid_link);
 1339                 }
 1340         }
 1341         return (ENOENT);
 1342 }
 1343 
 1344 /*
 1345  * Traverse our tree, and find the right node, execute whatever it points
 1346  * to, and return the resulting error code.
 1347  */
 1348 
 1349 static int
 1350 sysctl_root(SYSCTL_HANDLER_ARGS)
 1351 {
 1352         struct sysctl_oid *oid;
 1353         int error, indx, lvl;
 1354 
 1355         SYSCTL_ASSERT_LOCKED();
 1356 
 1357         error = sysctl_find_oid(arg1, arg2, &oid, &indx, req);
 1358         if (error)
 1359                 return (error);
 1360 
 1361         if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
 1362                 /*
 1363                  * You can't call a sysctl when it's a node, but has
 1364                  * no handler.  Inform the user that it's a node.
 1365                  * The indx may or may not be the same as namelen.
 1366                  */
 1367                 if (oid->oid_handler == NULL)
 1368                         return (EISDIR);
 1369         }
 1370 
 1371         /* Is this sysctl writable? */
 1372         if (req->newptr && !(oid->oid_kind & CTLFLAG_WR))
 1373                 return (EPERM);
 1374 
 1375         KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL"));
 1376 
 1377         /* Is this sysctl sensitive to securelevels? */
 1378         if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) {
 1379                 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE;
 1380                 error = securelevel_gt(req->td->td_ucred, lvl);
 1381                 if (error)
 1382                         return (error);
 1383         }
 1384 
 1385         /* Is this sysctl writable by only privileged users? */
 1386         if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) {
 1387                 if (oid->oid_kind & CTLFLAG_PRISON)
 1388                         error = priv_check(req->td, PRIV_SYSCTL_WRITEJAIL);
 1389                 else
 1390                         error = priv_check(req->td, PRIV_SYSCTL_WRITE);
 1391                 if (error)
 1392                         return (error);
 1393         }
 1394 
 1395         if (!oid->oid_handler)
 1396                 return (EINVAL);
 1397 
 1398         if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
 1399                 arg1 = (int *)arg1 + indx;
 1400                 arg2 -= indx;
 1401         } else {
 1402                 arg1 = oid->oid_arg1;
 1403                 arg2 = oid->oid_arg2;
 1404         }
 1405 #ifdef MAC
 1406         error = mac_check_system_sysctl(req->td->td_ucred, oid, arg1, arg2,
 1407             req);
 1408         if (error != 0)
 1409                 return (error);
 1410 #endif
 1411         if (!(oid->oid_kind & CTLFLAG_MPSAFE))
 1412                 mtx_lock(&Giant);
 1413         error = oid->oid_handler(oid, arg1, arg2, req);
 1414         if (!(oid->oid_kind & CTLFLAG_MPSAFE))
 1415                 mtx_unlock(&Giant);
 1416 
 1417         return (error);
 1418 }
 1419 
 1420 #ifndef _SYS_SYSPROTO_H_
 1421 struct sysctl_args {
 1422         int     *name;
 1423         u_int   namelen;
 1424         void    *old;
 1425         size_t  *oldlenp;
 1426         void    *new;
 1427         size_t  newlen;
 1428 };
 1429 #endif
 1430 int
 1431 __sysctl(struct thread *td, struct sysctl_args *uap)
 1432 {
 1433         int error, i, name[CTL_MAXNAME];
 1434         size_t j;
 1435 
 1436         if (uap->namelen > CTL_MAXNAME || uap->namelen < 2)
 1437                 return (EINVAL);
 1438 
 1439         error = copyin(uap->name, &name, uap->namelen * sizeof(int));
 1440         if (error)
 1441                 return (error);
 1442 
 1443         error = userland_sysctl(td, name, uap->namelen,
 1444                 uap->old, uap->oldlenp, 0,
 1445                 uap->new, uap->newlen, &j, 0);
 1446         if (error && error != ENOMEM)
 1447                 return (error);
 1448         if (uap->oldlenp) {
 1449                 i = copyout(&j, uap->oldlenp, sizeof(j));
 1450                 if (i)
 1451                         return (i);
 1452         }
 1453         return (error);
 1454 }
 1455 
 1456 /*
 1457  * This is used from various compatibility syscalls too.  That's why name
 1458  * must be in kernel space.
 1459  */
 1460 int
 1461 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old,
 1462     size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval,
 1463     int flags)
 1464 {
 1465         int error = 0;
 1466         struct sysctl_req req;
 1467 
 1468         bzero(&req, sizeof req);
 1469 
 1470         req.td = td;
 1471         req.flags = flags;
 1472 
 1473         if (oldlenp) {
 1474                 if (inkernel) {
 1475                         req.oldlen = *oldlenp;
 1476                 } else {
 1477                         error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp));
 1478                         if (error)
 1479                                 return (error);
 1480                 }
 1481         }
 1482         req.validlen = req.oldlen;
 1483 
 1484         if (old) {
 1485                 if (!useracc(old, req.oldlen, VM_PROT_WRITE))
 1486                         return (EFAULT);
 1487                 req.oldptr= old;
 1488         }
 1489 
 1490         if (new != NULL) {
 1491                 if (!useracc(new, newlen, VM_PROT_READ))
 1492                         return (EFAULT);
 1493                 req.newlen = newlen;
 1494                 req.newptr = new;
 1495         }
 1496 
 1497         req.oldfunc = sysctl_old_user;
 1498         req.newfunc = sysctl_new_user;
 1499         req.lock = REQ_LOCKED;
 1500 
 1501         SYSCTL_XLOCK();
 1502 
 1503         for (;;) {
 1504                 req.oldidx = 0;
 1505                 req.newidx = 0;
 1506                 error = sysctl_root(0, name, namelen, &req);
 1507                 if (error != EAGAIN)
 1508                         break;
 1509                 uio_yield();
 1510         }
 1511 
 1512 
 1513         if (req.lock == REQ_WIRED && req.validlen > 0)
 1514                 vsunlock(req.oldptr, req.validlen);
 1515         SYSCTL_XUNLOCK();
 1516 
 1517         if (error && error != ENOMEM)
 1518                 return (error);
 1519 
 1520         if (retval) {
 1521                 if (req.oldptr && req.oldidx > req.validlen)
 1522                         *retval = req.validlen;
 1523                 else
 1524                         *retval = req.oldidx;
 1525         }
 1526         return (error);
 1527 }
Cache object: 2e1501741563512902ed5f058ee956e1
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.
FreeBSD/Linux Kernel Cross Reference sys/kern/kern_sysctl.c

FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sysctl.c
