kern_sysctl.c

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    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  * Locking - this locks the sysctl tree in memory.
   68  */
   69 static struct sx sysctllock;
   70 
   71 #define SYSCTL_LOCK()           sx_xlock(&sysctllock)
   72 #define SYSCTL_UNLOCK()         sx_xunlock(&sysctllock)
   73 #define SYSCTL_INIT()           sx_init(&sysctllock, "sysctl lock")
   74 
   75 static int sysctl_root(SYSCTL_HANDLER_ARGS);
   76 
   77 struct sysctl_oid_list sysctl__children; /* root list */
   78 
   79 static struct sysctl_oid *
   80 sysctl_find_oidname(const char *name, struct sysctl_oid_list *list)
   81 {
   82         struct sysctl_oid *oidp;
   83 
   84         SLIST_FOREACH(oidp, list, oid_link) {
   85                 if (strcmp(oidp->oid_name, name) == 0) {
   86                         return (oidp);
   87                 }
   88         }
   89         return (NULL);
   90 }
   91 
   92 /*
   93  * Initialization of the MIB tree.
   94  *
   95  * Order by number in each list.
   96  */
   97 
   98 void
   99 sysctl_register_oid(struct sysctl_oid *oidp)
  100 {
  101         struct sysctl_oid_list *parent = oidp->oid_parent;
  102         struct sysctl_oid *p;
  103         struct sysctl_oid *q;
  104 
  105         /*
  106          * First check if another oid with the same name already
  107          * exists in the parent's list.
  108          */
  109         p = sysctl_find_oidname(oidp->oid_name, parent);
  110         if (p != NULL) {
  111                 if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
  112                         p->oid_refcnt++;
  113                         return;
  114                 } else {
  115                         printf("can't re-use a leaf (%s)!\n", p->oid_name);
  116                         return;
  117                 }
  118         }
  119         /*
  120          * If this oid has a number OID_AUTO, give it a number which
  121          * is greater than any current oid.
  122          * NOTE: DO NOT change the starting value here, change it in
  123          * <sys/sysctl.h>, and make sure it is at least 256 to
  124          * accomodate e.g. net.inet.raw as a static sysctl node.
  125          */
  126         if (oidp->oid_number == OID_AUTO) {
  127                 static int newoid = CTL_AUTO_START;
  128 
  129                 oidp->oid_number = newoid++;
  130                 if (newoid == 0x7fffffff)
  131                         panic("out of oids");
  132         }
  133 #if 0
  134         else if (oidp->oid_number >= CTL_AUTO_START) {
  135                 /* do not panic; this happens when unregistering sysctl sets */
  136                 printf("static sysctl oid too high: %d", oidp->oid_number);
  137         }
  138 #endif
  139 
  140         /*
  141          * Insert the oid into the parent's list in order.
  142          */
  143         q = NULL;
  144         SLIST_FOREACH(p, parent, oid_link) {
  145                 if (oidp->oid_number < p->oid_number)
  146                         break;
  147                 q = p;
  148         }
  149         if (q)
  150                 SLIST_INSERT_AFTER(q, oidp, oid_link);
  151         else
  152                 SLIST_INSERT_HEAD(parent, oidp, oid_link);
  153 }
  154 
  155 void
  156 sysctl_unregister_oid(struct sysctl_oid *oidp)
  157 {
  158         struct sysctl_oid *p;
  159         int error;
  160 
  161         error = ENOENT;
  162         if (oidp->oid_number == OID_AUTO) {
  163                 error = EINVAL;
  164         } else {
  165                 SLIST_FOREACH(p, oidp->oid_parent, oid_link) {
  166                         if (p == oidp) {
  167                                 SLIST_REMOVE(oidp->oid_parent, oidp,
  168                                     sysctl_oid, oid_link);
  169                                 error = 0;
  170                                 break;
  171                         }
  172                 }
  173         }
  174 
  175         /* 
  176          * This can happen when a module fails to register and is
  177          * being unloaded afterwards.  It should not be a panic()
  178          * for normal use.
  179          */
  180         if (error)
  181                 printf("%s: failed to unregister sysctl\n", __func__);
  182 }
  183 
  184 /* Initialize a new context to keep track of dynamically added sysctls. */
  185 int
  186 sysctl_ctx_init(struct sysctl_ctx_list *c)
  187 {
  188 
  189         if (c == NULL) {
  190                 return (EINVAL);
  191         }
  192         TAILQ_INIT(c);
  193         return (0);
  194 }
  195 
  196 /* Free the context, and destroy all dynamic oids registered in this context */
  197 int
  198 sysctl_ctx_free(struct sysctl_ctx_list *clist)
  199 {
  200         struct sysctl_ctx_entry *e, *e1;
  201         int error;
  202 
  203         error = 0;
  204         /*
  205          * First perform a "dry run" to check if it's ok to remove oids.
  206          * XXX FIXME
  207          * XXX This algorithm is a hack. But I don't know any
  208          * XXX better solution for now...
  209          */
  210         TAILQ_FOREACH(e, clist, link) {
  211                 error = sysctl_remove_oid(e->entry, 0, 0);
  212                 if (error)
  213                         break;
  214         }
  215         /*
  216          * Restore deregistered entries, either from the end,
  217          * or from the place where error occured.
  218          * e contains the entry that was not unregistered
  219          */
  220         if (error)
  221                 e1 = TAILQ_PREV(e, sysctl_ctx_list, link);
  222         else
  223                 e1 = TAILQ_LAST(clist, sysctl_ctx_list);
  224         while (e1 != NULL) {
  225                 sysctl_register_oid(e1->entry);
  226                 e1 = TAILQ_PREV(e1, sysctl_ctx_list, link);
  227         }
  228         if (error)
  229                 return(EBUSY);
  230         /* Now really delete the entries */
  231         e = TAILQ_FIRST(clist);
  232         while (e != NULL) {
  233                 e1 = TAILQ_NEXT(e, link);
  234                 error = sysctl_remove_oid(e->entry, 1, 0);
  235                 if (error)
  236                         panic("sysctl_remove_oid: corrupt tree, entry: %s",
  237                             e->entry->oid_name);
  238                 free(e, M_SYSCTLOID);
  239                 e = e1;
  240         }
  241         return (error);
  242 }
  243 
  244 /* Add an entry to the context */
  245 struct sysctl_ctx_entry *
  246 sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
  247 {
  248         struct sysctl_ctx_entry *e;
  249 
  250         if (clist == NULL || oidp == NULL)
  251                 return(NULL);
  252         e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK);
  253         e->entry = oidp;
  254         TAILQ_INSERT_HEAD(clist, e, link);
  255         return (e);
  256 }
  257 
  258 /* Find an entry in the context */
  259 struct sysctl_ctx_entry *
  260 sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
  261 {
  262         struct sysctl_ctx_entry *e;
  263 
  264         if (clist == NULL || oidp == NULL)
  265                 return(NULL);
  266         TAILQ_FOREACH(e, clist, link) {
  267                 if(e->entry == oidp)
  268                         return(e);
  269         }
  270         return (e);
  271 }
  272 
  273 /*
  274  * Delete an entry from the context.
  275  * NOTE: this function doesn't free oidp! You have to remove it
  276  * with sysctl_remove_oid().
  277  */
  278 int
  279 sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp)
  280 {
  281         struct sysctl_ctx_entry *e;
  282 
  283         if (clist == NULL || oidp == NULL)
  284                 return (EINVAL);
  285         e = sysctl_ctx_entry_find(clist, oidp);
  286         if (e != NULL) {
  287                 TAILQ_REMOVE(clist, e, link);
  288                 free(e, M_SYSCTLOID);
  289                 return (0);
  290         } else
  291                 return (ENOENT);
  292 }
  293 
  294 /*
  295  * Remove dynamically created sysctl trees.
  296  * oidp - top of the tree to be removed
  297  * del - if 0 - just deregister, otherwise free up entries as well
  298  * recurse - if != 0 traverse the subtree to be deleted
  299  */
  300 int
  301 sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse)
  302 {
  303         struct sysctl_oid *p;
  304         int error;
  305 
  306         if (oidp == NULL)
  307                 return(EINVAL);
  308         if ((oidp->oid_kind & CTLFLAG_DYN) == 0) {
  309                 printf("can't remove non-dynamic nodes!\n");
  310                 return (EINVAL);
  311         }
  312         /*
  313          * WARNING: normal method to do this should be through
  314          * sysctl_ctx_free(). Use recursing as the last resort
  315          * method to purge your sysctl tree of leftovers...
  316          * However, if some other code still references these nodes,
  317          * it will panic.
  318          */
  319         if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
  320                 if (oidp->oid_refcnt == 1) {
  321                         SLIST_FOREACH(p, SYSCTL_CHILDREN(oidp), oid_link) {
  322                                 if (!recurse)
  323                                         return (ENOTEMPTY);
  324                                 error = sysctl_remove_oid(p, del, recurse);
  325                                 if (error)
  326                                         return (error);
  327                         }
  328                         if (del)
  329                                 free(SYSCTL_CHILDREN(oidp), M_SYSCTLOID);
  330                 }
  331         }
  332         if (oidp->oid_refcnt > 1 ) {
  333                 oidp->oid_refcnt--;
  334         } else {
  335                 if (oidp->oid_refcnt == 0) {
  336                         printf("Warning: bad oid_refcnt=%u (%s)!\n",
  337                                 oidp->oid_refcnt, oidp->oid_name);
  338                         return (EINVAL);
  339                 }
  340                 sysctl_unregister_oid(oidp);
  341                 if (del) {
  342                         if (oidp->oid_descr)
  343                                 free((void *)(uintptr_t)(const void *)oidp->oid_descr, M_SYSCTLOID);
  344                         free((void *)(uintptr_t)(const void *)oidp->oid_name,
  345                              M_SYSCTLOID);
  346                         free(oidp, M_SYSCTLOID);
  347                 }
  348         }
  349         return (0);
  350 }
  351 
  352 /*
  353  * Create new sysctls at run time.
  354  * clist may point to a valid context initialized with sysctl_ctx_init().
  355  */
  356 struct sysctl_oid *
  357 sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent,
  358         int number, const char *name, int kind, void *arg1, int arg2,
  359         int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr)
  360 {
  361         struct sysctl_oid *oidp;
  362         ssize_t len;
  363         char *newname;
  364 
  365         /* You have to hook up somewhere.. */
  366         if (parent == NULL)
  367                 return(NULL);
  368         /* Check if the node already exists, otherwise create it */
  369         oidp = sysctl_find_oidname(name, parent);
  370         if (oidp != NULL) {
  371                 if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
  372                         oidp->oid_refcnt++;
  373                         /* Update the context */
  374                         if (clist != NULL)
  375                                 sysctl_ctx_entry_add(clist, oidp);
  376                         return (oidp);
  377                 } else {
  378                         printf("can't re-use a leaf (%s)!\n", name);
  379                         return (NULL);
  380                 }
  381         }
  382         oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO);
  383         oidp->oid_parent = parent;
  384         SLIST_NEXT(oidp, oid_link) = NULL;
  385         oidp->oid_number = number;
  386         oidp->oid_refcnt = 1;
  387         len = strlen(name);
  388         newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK);
  389         bcopy(name, newname, len + 1);
  390         newname[len] = '\0';
  391         oidp->oid_name = newname;
  392         oidp->oid_handler = handler;
  393         oidp->oid_kind = CTLFLAG_DYN | kind;
  394         if ((kind & CTLTYPE) == CTLTYPE_NODE) {
  395                 /* Allocate space for children */
  396                 SYSCTL_CHILDREN_SET(oidp, malloc(sizeof(struct sysctl_oid_list),
  397                     M_SYSCTLOID, M_WAITOK));
  398                 SLIST_INIT(SYSCTL_CHILDREN(oidp));
  399         } else {
  400                 oidp->oid_arg1 = arg1;
  401                 oidp->oid_arg2 = arg2;
  402         }
  403         oidp->oid_fmt = fmt;
  404         if (descr) {
  405                 int len = strlen(descr) + 1;
  406                 oidp->oid_descr = malloc(len, M_SYSCTLOID, M_WAITOK);
  407                 if (oidp->oid_descr)
  408                         strcpy((char *)(uintptr_t)(const void *)oidp->oid_descr, descr);
  409         }
  410         /* Update the context, if used */
  411         if (clist != NULL)
  412                 sysctl_ctx_entry_add(clist, oidp);
  413         /* Register this oid */
  414         sysctl_register_oid(oidp);
  415         return (oidp);
  416 }
  417 
  418 /*
  419  * Reparent an existing oid.
  420  */
  421 int
  422 sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent)
  423 {
  424         struct sysctl_oid *oidp;
  425 
  426         if (oid->oid_parent == parent)
  427                 return (0);
  428         oidp = sysctl_find_oidname(oid->oid_name, parent);
  429         if (oidp != NULL)
  430                 return (EEXIST);
  431         sysctl_unregister_oid(oid);
  432         oid->oid_parent = parent;
  433         oid->oid_number = OID_AUTO;
  434         sysctl_register_oid(oid);
  435         return (0);
  436 }
  437 
  438 /*
  439  * Register the kernel's oids on startup.
  440  */
  441 SET_DECLARE(sysctl_set, struct sysctl_oid);
  442 
  443 static void
  444 sysctl_register_all(void *arg)
  445 {
  446         struct sysctl_oid **oidp;
  447 
  448         SYSCTL_INIT();
  449         SET_FOREACH(oidp, sysctl_set)
  450                 sysctl_register_oid(*oidp);
  451 }
  452 SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_ANY, sysctl_register_all, 0);
  453 
  454 /*
  455  * "Staff-functions"
  456  *
  457  * These functions implement a presently undocumented interface 
  458  * used by the sysctl program to walk the tree, and get the type
  459  * so it can print the value.
  460  * This interface is under work and consideration, and should probably
  461  * be killed with a big axe by the first person who can find the time.
  462  * (be aware though, that the proper interface isn't as obvious as it
  463  * may seem, there are various conflicting requirements.
  464  *
  465  * {0,0}        printf the entire MIB-tree.
  466  * {0,1,...}    return the name of the "..." OID.
  467  * {0,2,...}    return the next OID.
  468  * {0,3}        return the OID of the name in "new"
  469  * {0,4,...}    return the kind & format info for the "..." OID.
  470  * {0,5,...}    return the description the "..." OID.
  471  */
  472 
  473 #ifdef SYSCTL_DEBUG
  474 static void
  475 sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i)
  476 {
  477         int k;
  478         struct sysctl_oid *oidp;
  479 
  480         SLIST_FOREACH(oidp, l, oid_link) {
  481 
  482                 for (k=0; k<i; k++)
  483                         printf(" ");
  484 
  485                 printf("%d %s ", oidp->oid_number, oidp->oid_name);
  486 
  487                 printf("%c%c",
  488                         oidp->oid_kind & CTLFLAG_RD ? 'R':' ',
  489                         oidp->oid_kind & CTLFLAG_WR ? 'W':' ');
  490 
  491                 if (oidp->oid_handler)
  492                         printf(" *Handler");
  493 
  494                 switch (oidp->oid_kind & CTLTYPE) {
  495                         case CTLTYPE_NODE:
  496                                 printf(" Node\n");
  497                                 if (!oidp->oid_handler) {
  498                                         sysctl_sysctl_debug_dump_node(
  499                                                 oidp->oid_arg1, i+2);
  500                                 }
  501                                 break;
  502                         case CTLTYPE_INT:    printf(" Int\n"); break;
  503                         case CTLTYPE_STRING: printf(" String\n"); break;
  504                         case CTLTYPE_QUAD:   printf(" Quad\n"); break;
  505                         case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break;
  506                         default:             printf("\n");
  507                 }
  508 
  509         }
  510 }
  511 
  512 static int
  513 sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS)
  514 {
  515         int error;
  516 
  517         error = priv_check(req->td, PRIV_SYSCTL_DEBUG);
  518         if (error)
  519                 return (error);
  520         sysctl_sysctl_debug_dump_node(&sysctl__children, 0);
  521         return (ENOENT);
  522 }
  523 
  524 SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD,
  525         0, 0, sysctl_sysctl_debug, "-", "");
  526 #endif
  527 
  528 static int
  529 sysctl_sysctl_name(SYSCTL_HANDLER_ARGS)
  530 {
  531         int *name = (int *) arg1;
  532         u_int namelen = arg2;
  533         int error = 0;
  534         struct sysctl_oid *oid;
  535         struct sysctl_oid_list *lsp = &sysctl__children, *lsp2;
  536         char buf[10];
  537 
  538         while (namelen) {
  539                 if (!lsp) {
  540                         snprintf(buf,sizeof(buf),"%d",*name);
  541                         if (req->oldidx)
  542                                 error = SYSCTL_OUT(req, ".", 1);
  543                         if (!error)
  544                                 error = SYSCTL_OUT(req, buf, strlen(buf));
  545                         if (error)
  546                                 return (error);
  547                         namelen--;
  548                         name++;
  549                         continue;
  550                 }
  551                 lsp2 = 0;
  552                 SLIST_FOREACH(oid, lsp, oid_link) {
  553                         if (oid->oid_number != *name)
  554                                 continue;
  555 
  556                         if (req->oldidx)
  557                                 error = SYSCTL_OUT(req, ".", 1);
  558                         if (!error)
  559                                 error = SYSCTL_OUT(req, oid->oid_name,
  560                                         strlen(oid->oid_name));
  561                         if (error)
  562                                 return (error);
  563 
  564                         namelen--;
  565                         name++;
  566 
  567                         if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) 
  568                                 break;
  569 
  570                         if (oid->oid_handler)
  571                                 break;
  572 
  573                         lsp2 = (struct sysctl_oid_list *)oid->oid_arg1;
  574                         break;
  575                 }
  576                 lsp = lsp2;
  577         }
  578         return (SYSCTL_OUT(req, "", 1));
  579 }
  580 
  581 static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, "");
  582 
  583 static int
  584 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 
  585         int *next, int *len, int level, struct sysctl_oid **oidpp)
  586 {
  587         struct sysctl_oid *oidp;
  588 
  589         *len = level;
  590         SLIST_FOREACH(oidp, lsp, oid_link) {
  591                 *next = oidp->oid_number;
  592                 *oidpp = oidp;
  593 
  594                 if (oidp->oid_kind & CTLFLAG_SKIP)
  595                         continue;
  596 
  597                 if (!namelen) {
  598                         if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 
  599                                 return (0);
  600                         if (oidp->oid_handler) 
  601                                 /* We really should call the handler here...*/
  602                                 return (0);
  603                         lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
  604                         if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 
  605                                 len, level+1, oidpp))
  606                                 return (0);
  607                         goto emptynode;
  608                 }
  609 
  610                 if (oidp->oid_number < *name)
  611                         continue;
  612 
  613                 if (oidp->oid_number > *name) {
  614                         if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
  615                                 return (0);
  616                         if (oidp->oid_handler)
  617                                 return (0);
  618                         lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
  619                         if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 
  620                                 next+1, len, level+1, oidpp))
  621                                 return (0);
  622                         goto next;
  623                 }
  624                 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
  625                         continue;
  626 
  627                 if (oidp->oid_handler)
  628                         continue;
  629 
  630                 lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
  631                 if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 
  632                         len, level+1, oidpp))
  633                         return (0);
  634         next:
  635                 namelen = 1;
  636         emptynode:
  637                 *len = level;
  638         }
  639         return (1);
  640 }
  641 
  642 static int
  643 sysctl_sysctl_next(SYSCTL_HANDLER_ARGS)
  644 {
  645         int *name = (int *) arg1;
  646         u_int namelen = arg2;
  647         int i, j, error;
  648         struct sysctl_oid *oid;
  649         struct sysctl_oid_list *lsp = &sysctl__children;
  650         int newoid[CTL_MAXNAME];
  651 
  652         i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid);
  653         if (i)
  654                 return (ENOENT);
  655         error = SYSCTL_OUT(req, newoid, j * sizeof (int));
  656         return (error);
  657 }
  658 
  659 static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, "");
  660 
  661 static int
  662 name2oid (char *name, int *oid, int *len, struct sysctl_oid **oidpp)
  663 {
  664         int i;
  665         struct sysctl_oid *oidp;
  666         struct sysctl_oid_list *lsp = &sysctl__children;
  667         char *p;
  668 
  669         if (!*name)
  670                 return (ENOENT);
  671 
  672         p = name + strlen(name) - 1 ;
  673         if (*p == '.')
  674                 *p = '\0';
  675 
  676         *len = 0;
  677 
  678         for (p = name; *p && *p != '.'; p++) 
  679                 ;
  680         i = *p;
  681         if (i == '.')
  682                 *p = '\0';
  683 
  684         oidp = SLIST_FIRST(lsp);
  685 
  686         while (oidp && *len < CTL_MAXNAME) {
  687                 if (strcmp(name, oidp->oid_name)) {
  688                         oidp = SLIST_NEXT(oidp, oid_link);
  689                         continue;
  690                 }
  691                 *oid++ = oidp->oid_number;
  692                 (*len)++;
  693 
  694                 if (!i) {
  695                         if (oidpp)
  696                                 *oidpp = oidp;
  697                         return (0);
  698                 }
  699 
  700                 if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
  701                         break;
  702 
  703                 if (oidp->oid_handler)
  704                         break;
  705 
  706                 lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
  707                 oidp = SLIST_FIRST(lsp);
  708                 name = p+1;
  709                 for (p = name; *p && *p != '.'; p++) 
  710                                 ;
  711                 i = *p;
  712                 if (i == '.')
  713                         *p = '\0';
  714         }
  715         return (ENOENT);
  716 }
  717 
  718 static int
  719 sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
  720 {
  721         char *p;
  722         int error, oid[CTL_MAXNAME], len;
  723         struct sysctl_oid *op = 0;
  724 
  725         if (!req->newlen) 
  726                 return (ENOENT);
  727         if (req->newlen >= MAXPATHLEN)  /* XXX arbitrary, undocumented */
  728                 return (ENAMETOOLONG);
  729 
  730         p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK);
  731 
  732         error = SYSCTL_IN(req, p, req->newlen);
  733         if (error) {
  734                 free(p, M_SYSCTL);
  735                 return (error);
  736         }
  737 
  738         p [req->newlen] = '\0';
  739 
  740         error = name2oid(p, oid, &len, &op);
  741 
  742         free(p, M_SYSCTL);
  743 
  744         if (error)
  745                 return (error);
  746 
  747         error = SYSCTL_OUT(req, oid, len * sizeof *oid);
  748         return (error);
  749 }
  750 
  751 SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY, 0, 0, 
  752         sysctl_sysctl_name2oid, "I", "");
  753 
  754 static int
  755 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
  756 {
  757         struct sysctl_oid *oid;
  758         int error;
  759 
  760         error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
  761         if (error)
  762                 return (error);
  763 
  764         if (!oid->oid_fmt)
  765                 return (ENOENT);
  766         error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind));
  767         if (error)
  768                 return (error);
  769         error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1);
  770         return (error);
  771 }
  772 
  773 
  774 static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD, sysctl_sysctl_oidfmt, "");
  775 
  776 static int
  777 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS)
  778 {
  779         struct sysctl_oid *oid;
  780         int error;
  781 
  782         error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
  783         if (error)
  784                 return (error);
  785 
  786         if (!oid->oid_descr)
  787                 return (ENOENT);
  788         error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1);
  789         return (error);
  790 }
  791 
  792 static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD, sysctl_sysctl_oiddescr, "");
  793 
  794 /*
  795  * Default "handler" functions.
  796  */
  797 
  798 /*
  799  * Handle an int, signed or unsigned.
  800  * Two cases:
  801  *     a variable:  point arg1 at it.
  802  *     a constant:  pass it in arg2.
  803  */
  804 
  805 int
  806 sysctl_handle_int(SYSCTL_HANDLER_ARGS)
  807 {
  808         int tmpout, error = 0;
  809 
  810         /*
  811          * Attempt to get a coherent snapshot by making a copy of the data.
  812          */
  813         if (arg1)
  814                 tmpout = *(int *)arg1;
  815         else
  816                 tmpout = arg2;
  817         error = SYSCTL_OUT(req, &tmpout, sizeof(int));
  818 
  819         if (error || !req->newptr)
  820                 return (error);
  821 
  822         if (!arg1)
  823                 error = EPERM;
  824         else
  825                 error = SYSCTL_IN(req, arg1, sizeof(int));
  826         return (error);
  827 }
  828 
  829 
  830 /*
  831  * Based on on sysctl_handle_int() convert milliseconds into ticks.
  832  */
  833 
  834 int
  835 sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS)
  836 {
  837         int error, s, tt;
  838 
  839         tt = *(int *)oidp->oid_arg1;
  840         s = (int)((int64_t)tt * 1000 / hz);
  841 
  842         error = sysctl_handle_int(oidp, &s, 0, req);
  843         if (error || !req->newptr)
  844                 return (error);
  845 
  846         tt = (int)((int64_t)s * hz / 1000);
  847         if (tt < 1)
  848                 return (EINVAL);
  849 
  850         *(int *)oidp->oid_arg1 = tt;
  851         return (0);
  852 }
  853 
  854 
  855 /*
  856  * Handle a long, signed or unsigned.  arg1 points to it.
  857  */
  858 
  859 int
  860 sysctl_handle_long(SYSCTL_HANDLER_ARGS)
  861 {
  862         int error = 0;
  863         long tmplong;
  864 #ifdef SCTL_MASK32
  865         int tmpint;
  866 #endif
  867 
  868         /*
  869          * Attempt to get a coherent snapshot by making a copy of the data.
  870          */
  871         if (!arg1)
  872                 return (EINVAL);
  873         tmplong = *(long *)arg1;
  874 #ifdef SCTL_MASK32
  875         if (req->flags & SCTL_MASK32) {
  876                 tmpint = tmplong;
  877                 error = SYSCTL_OUT(req, &tmpint, sizeof(int));
  878         } else
  879 #endif
  880                 error = SYSCTL_OUT(req, &tmplong, sizeof(long));
  881 
  882         if (error || !req->newptr)
  883                 return (error);
  884 
  885 #ifdef SCTL_MASK32
  886         if (req->flags & SCTL_MASK32) {
  887                 error = SYSCTL_IN(req, &tmpint, sizeof(int));
  888                 *(long *)arg1 = (long)tmpint;
  889         } else
  890 #endif
  891                 error = SYSCTL_IN(req, arg1, sizeof(long));
  892         return (error);
  893 }
  894 
  895 /*
  896  * Handle a 64 bit int, signed or unsigned.  arg1 points to it.
  897  */
  898 
  899 int
  900 sysctl_handle_quad(SYSCTL_HANDLER_ARGS)
  901 {
  902         int error = 0;
  903         uint64_t tmpout;
  904 
  905         /*
  906          * Attempt to get a coherent snapshot by making a copy of the data.
  907          */
  908         if (!arg1)
  909                 return (EINVAL);
  910         tmpout = *(uint64_t *)arg1;
  911         error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t));
  912 
  913         if (error || !req->newptr)
  914                 return (error);
  915 
  916         error = SYSCTL_IN(req, arg1, sizeof(uint64_t));
  917         return (error);
  918 }
  919 
  920 /*
  921  * Handle our generic '\0' terminated 'C' string.
  922  * Two cases:
  923  *      a variable string:  point arg1 at it, arg2 is max length.
  924  *      a constant string:  point arg1 at it, arg2 is zero.
  925  */
  926 
  927 int
  928 sysctl_handle_string(SYSCTL_HANDLER_ARGS)
  929 {
  930         int error=0;
  931         char *tmparg;
  932         size_t outlen;
  933 
  934         /*
  935          * Attempt to get a coherent snapshot by copying to a
  936          * temporary kernel buffer.
  937          */
  938 retry:
  939         outlen = strlen((char *)arg1)+1;
  940         tmparg = malloc(outlen, M_SYSCTLTMP, M_WAITOK);
  941 
  942         if (strlcpy(tmparg, (char *)arg1, outlen) >= outlen) {
  943                 free(tmparg, M_SYSCTLTMP);
  944                 goto retry;
  945         }
  946 
  947         error = SYSCTL_OUT(req, tmparg, outlen);
  948         free(tmparg, M_SYSCTLTMP);
  949 
  950         if (error || !req->newptr)
  951                 return (error);
  952 
  953         if ((req->newlen - req->newidx) >= arg2) {
  954                 error = EINVAL;
  955         } else {
  956                 arg2 = (req->newlen - req->newidx);
  957                 error = SYSCTL_IN(req, arg1, arg2);
  958                 ((char *)arg1)[arg2] = '\0';
  959         }
  960 
  961         return (error);
  962 }
  963 
  964 /*
  965  * Handle any kind of opaque data.
  966  * arg1 points to it, arg2 is the size.
  967  */
  968 
  969 int
  970 sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
  971 {
  972         int error, tries;
  973         u_int generation;
  974         struct sysctl_req req2;
  975 
  976         /*
  977          * Attempt to get a coherent snapshot, by using the thread
  978          * pre-emption counter updated from within mi_switch() to
  979          * determine if we were pre-empted during a bcopy() or
  980          * copyout(). Make 3 attempts at doing this before giving up.
  981          * If we encounter an error, stop immediately.
  982          */
  983         tries = 0;
  984         req2 = *req;
  985 retry:
  986         generation = curthread->td_generation;
  987         error = SYSCTL_OUT(req, arg1, arg2);
  988         if (error)
  989                 return (error);
  990         tries++;
  991         if (generation != curthread->td_generation && tries < 3) {
  992                 *req = req2;
  993                 goto retry;
  994         }
  995 
  996         error = SYSCTL_IN(req, arg1, arg2);
  997 
  998         return (error);
  999 }
 1000 
 1001 /*
 1002  * Transfer functions to/from kernel space.
 1003  * XXX: rather untested at this point
 1004  */
 1005 static int
 1006 sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l)
 1007 {
 1008         size_t i = 0;
 1009 
 1010         if (req->oldptr) {
 1011                 i = l;
 1012                 if (req->oldlen <= req->oldidx)
 1013                         i = 0;
 1014                 else
 1015                         if (i > req->oldlen - req->oldidx)
 1016                                 i = req->oldlen - req->oldidx;
 1017                 if (i > 0)
 1018                         bcopy(p, (char *)req->oldptr + req->oldidx, i);
 1019         }
 1020         req->oldidx += l;
 1021         if (req->oldptr && i != l)
 1022                 return (ENOMEM);
 1023         return (0);
 1024 }
 1025 
 1026 static int
 1027 sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l)
 1028 {
 1029         if (!req->newptr)
 1030                 return (0);
 1031         if (req->newlen - req->newidx < l)
 1032                 return (EINVAL);
 1033         bcopy((char *)req->newptr + req->newidx, p, l);
 1034         req->newidx += l;
 1035         return (0);
 1036 }
 1037 
 1038 int
 1039 kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old,
 1040     size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags)
 1041 {
 1042         int error = 0;
 1043         struct sysctl_req req;
 1044 
 1045         bzero(&req, sizeof req);
 1046 
 1047         req.td = td;
 1048         req.flags = flags;
 1049 
 1050         if (oldlenp) {
 1051                 req.oldlen = *oldlenp;
 1052         }
 1053         req.validlen = req.oldlen;
 1054 
 1055         if (old) {
 1056                 req.oldptr= old;
 1057         }
 1058 
 1059         if (new != NULL) {
 1060                 req.newlen = newlen;
 1061                 req.newptr = new;
 1062         }
 1063 
 1064         req.oldfunc = sysctl_old_kernel;
 1065         req.newfunc = sysctl_new_kernel;
 1066         req.lock = REQ_LOCKED;
 1067 
 1068         SYSCTL_LOCK();
 1069 
 1070         error = sysctl_root(0, name, namelen, &req);
 1071 
 1072         if (req.lock == REQ_WIRED && req.validlen > 0)
 1073                 vsunlock(req.oldptr, req.validlen);
 1074 
 1075         SYSCTL_UNLOCK();
 1076 
 1077         if (error && error != ENOMEM)
 1078                 return (error);
 1079 
 1080         if (retval) {
 1081                 if (req.oldptr && req.oldidx > req.validlen)
 1082                         *retval = req.validlen;
 1083                 else
 1084                         *retval = req.oldidx;
 1085         }
 1086         return (error);
 1087 }
 1088 
 1089 int
 1090 kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp,
 1091     void *new, size_t newlen, size_t *retval, int flags)
 1092 {
 1093         int oid[CTL_MAXNAME];
 1094         size_t oidlen, plen;
 1095         int error;
 1096 
 1097         oid[0] = 0;             /* sysctl internal magic */
 1098         oid[1] = 3;             /* name2oid */
 1099         oidlen = sizeof(oid);
 1100 
 1101         error = kernel_sysctl(td, oid, 2, oid, &oidlen,
 1102             (void *)name, strlen(name), &plen, flags);
 1103         if (error)
 1104                 return (error);
 1105 
 1106         error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp,
 1107             new, newlen, retval, flags);
 1108         return (error);
 1109 }
 1110 
 1111 /*
 1112  * Transfer function to/from user space.
 1113  */
 1114 static int
 1115 sysctl_old_user(struct sysctl_req *req, const void *p, size_t l)
 1116 {
 1117         int error = 0;
 1118         size_t i, len, origidx;
 1119 
 1120         origidx = req->oldidx;
 1121         req->oldidx += l;
 1122         if (req->oldptr == NULL)
 1123                 return (0);
 1124         /*
 1125          * If we have not wired the user supplied buffer and we are currently
 1126          * holding locks, drop a witness warning, as it's possible that
 1127          * write operations to the user page can sleep.
 1128          */
 1129         if (req->lock != REQ_WIRED)
 1130                 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
 1131                     "sysctl_old_user()");
 1132         i = l;
 1133         len = req->validlen;
 1134         if (len <= origidx)
 1135                 i = 0;
 1136         else {
 1137                 if (i > len - origidx)
 1138                         i = len - origidx;
 1139                 error = copyout(p, (char *)req->oldptr + origidx, i);
 1140         }
 1141         if (error)
 1142                 return (error);
 1143         if (i < l)
 1144                 return (ENOMEM);
 1145         return (0);
 1146 }
 1147 
 1148 static int
 1149 sysctl_new_user(struct sysctl_req *req, void *p, size_t l)
 1150 {
 1151         int error;
 1152 
 1153         if (!req->newptr)
 1154                 return (0);
 1155         if (req->newlen - req->newidx < l)
 1156                 return (EINVAL);
 1157         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
 1158             "sysctl_new_user()");
 1159         error = copyin((char *)req->newptr + req->newidx, p, l);
 1160         req->newidx += l;
 1161         return (error);
 1162 }
 1163 
 1164 /*
 1165  * Wire the user space destination buffer.  If set to a value greater than
 1166  * zero, the len parameter limits the maximum amount of wired memory.
 1167  */
 1168 int
 1169 sysctl_wire_old_buffer(struct sysctl_req *req, size_t len)
 1170 {
 1171         int ret;
 1172         size_t i, wiredlen;
 1173         char *cp, dummy;
 1174 
 1175         wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen;
 1176         ret = 0;
 1177         if (req->lock == REQ_LOCKED && req->oldptr &&
 1178             req->oldfunc == sysctl_old_user) {
 1179                 if (wiredlen != 0) {
 1180                         ret = vslock(req->oldptr, wiredlen);
 1181                         if (ret != 0) {
 1182                                 if (ret != ENOMEM)
 1183                                         return (ret);
 1184                                 wiredlen = 0;
 1185                         }
 1186                         /*
 1187                          * Touch all the wired pages to avoid PTE modified
 1188                          * bit emulation traps on Alpha while holding locks
 1189                          * in the sysctl handler.
 1190                          */
 1191                         for (i = (wiredlen + PAGE_SIZE - 1) / PAGE_SIZE,
 1192                             cp = req->oldptr; i > 0; i--, cp += PAGE_SIZE) {
 1193                                 copyin(cp, &dummy, 1);
 1194                                 copyout(&dummy, cp, 1);
 1195                         }
 1196                 }
 1197                 req->lock = REQ_WIRED;
 1198                 req->validlen = wiredlen;
 1199         }
 1200         return (0);
 1201 }
 1202 
 1203 int
 1204 sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid,
 1205     int *nindx, struct sysctl_req *req)
 1206 {
 1207         struct sysctl_oid *oid;
 1208         int indx;
 1209 
 1210         oid = SLIST_FIRST(&sysctl__children);
 1211         indx = 0;
 1212         while (oid && indx < CTL_MAXNAME) {
 1213                 if (oid->oid_number == name[indx]) {
 1214                         indx++;
 1215                         if (oid->oid_kind & CTLFLAG_NOLOCK)
 1216                                 req->lock = REQ_UNLOCKED;
 1217                         if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
 1218                                 if (oid->oid_handler != NULL ||
 1219                                     indx == namelen) {
 1220                                         *noid = oid;
 1221                                         if (nindx != NULL)
 1222                                                 *nindx = indx;
 1223                                         return (0);
 1224                                 }
 1225                                 oid = SLIST_FIRST(
 1226                                     (struct sysctl_oid_list *)oid->oid_arg1);
 1227                         } else if (indx == namelen) {
 1228                                 *noid = oid;
 1229                                 if (nindx != NULL)
 1230                                         *nindx = indx;
 1231                                 return (0);
 1232                         } else {
 1233                                 return (ENOTDIR);
 1234                         }
 1235                 } else {
 1236                         oid = SLIST_NEXT(oid, oid_link);
 1237                 }
 1238         }
 1239         return (ENOENT);
 1240 }
 1241 
 1242 /*
 1243  * Traverse our tree, and find the right node, execute whatever it points
 1244  * to, and return the resulting error code.
 1245  */
 1246 
 1247 static int
 1248 sysctl_root(SYSCTL_HANDLER_ARGS)
 1249 {
 1250         struct sysctl_oid *oid;
 1251         int error, indx, lvl;
 1252 
 1253         error = sysctl_find_oid(arg1, arg2, &oid, &indx, req);
 1254         if (error)
 1255                 return (error);
 1256 
 1257         if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
 1258                 /*
 1259                  * You can't call a sysctl when it's a node, but has
 1260                  * no handler.  Inform the user that it's a node.
 1261                  * The indx may or may not be the same as namelen.
 1262                  */
 1263                 if (oid->oid_handler == NULL)
 1264                         return (EISDIR);
 1265         }
 1266 
 1267         /* Is this sysctl writable? */
 1268         if (req->newptr && !(oid->oid_kind & CTLFLAG_WR))
 1269                 return (EPERM);
 1270 
 1271         KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL"));
 1272 
 1273         /* Is this sysctl sensitive to securelevels? */
 1274         if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) {
 1275                 lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE;
 1276                 error = securelevel_gt(req->td->td_ucred, lvl);
 1277                 if (error)
 1278                         return (error);
 1279         }
 1280 
 1281         /* Is this sysctl writable by only privileged users? */
 1282         if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) {
 1283                 if (oid->oid_kind & CTLFLAG_PRISON)
 1284                         error = priv_check(req->td, PRIV_SYSCTL_WRITEJAIL);
 1285                 else
 1286                         error = priv_check(req->td, PRIV_SYSCTL_WRITE);
 1287                 if (error)
 1288                         return (error);
 1289         }
 1290 
 1291         if (!oid->oid_handler)
 1292                 return (EINVAL);
 1293 
 1294         if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
 1295                 arg1 = (int *)arg1 + indx;
 1296                 arg2 -= indx;
 1297         } else {
 1298                 arg1 = oid->oid_arg1;
 1299                 arg2 = oid->oid_arg2;
 1300         }
 1301 #ifdef MAC
 1302         error = mac_check_system_sysctl(req->td->td_ucred, oid, arg1, arg2,
 1303             req);
 1304         if (error != 0)
 1305                 return (error);
 1306 #endif
 1307         error = oid->oid_handler(oid, arg1, arg2, req);
 1308 
 1309         return (error);
 1310 }
 1311 
 1312 #ifndef _SYS_SYSPROTO_H_
 1313 struct sysctl_args {
 1314         int     *name;
 1315         u_int   namelen;
 1316         void    *old;
 1317         size_t  *oldlenp;
 1318         void    *new;
 1319         size_t  newlen;
 1320 };
 1321 #endif
 1322 int
 1323 __sysctl(struct thread *td, struct sysctl_args *uap)
 1324 {
 1325         int error, name[CTL_MAXNAME];
 1326         size_t j;
 1327 
 1328         if (uap->namelen > CTL_MAXNAME || uap->namelen < 2)
 1329                 return (EINVAL);
 1330 
 1331         error = copyin(uap->name, &name, uap->namelen * sizeof(int));
 1332         if (error)
 1333                 return (error);
 1334 
 1335         mtx_lock(&Giant);
 1336 
 1337         error = userland_sysctl(td, name, uap->namelen,
 1338                 uap->old, uap->oldlenp, 0,
 1339                 uap->new, uap->newlen, &j, 0);
 1340         if (error && error != ENOMEM)
 1341                 goto done2;
 1342         if (uap->oldlenp) {
 1343                 int i = copyout(&j, uap->oldlenp, sizeof(j));
 1344                 if (i)
 1345                         error = i;
 1346         }
 1347 done2:
 1348         mtx_unlock(&Giant);
 1349         return (error);
 1350 }
 1351 
 1352 /*
 1353  * This is used from various compatibility syscalls too.  That's why name
 1354  * must be in kernel space.
 1355  */
 1356 int
 1357 userland_sysctl(struct thread *td, int *name, u_int namelen, void *old,
 1358     size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval,
 1359     int flags)
 1360 {
 1361         int error = 0;
 1362         struct sysctl_req req;
 1363 
 1364         bzero(&req, sizeof req);
 1365 
 1366         req.td = td;
 1367         req.flags = flags;
 1368 
 1369         if (oldlenp) {
 1370                 if (inkernel) {
 1371                         req.oldlen = *oldlenp;
 1372                 } else {
 1373                         error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp));
 1374                         if (error)
 1375                                 return (error);
 1376                 }
 1377         }
 1378         req.validlen = req.oldlen;
 1379 
 1380         if (old) {
 1381                 if (!useracc(old, req.oldlen, VM_PROT_WRITE))
 1382                         return (EFAULT);
 1383                 req.oldptr= old;
 1384         }
 1385 
 1386         if (new != NULL) {
 1387                 if (!useracc(new, newlen, VM_PROT_READ))
 1388                         return (EFAULT);
 1389                 req.newlen = newlen;
 1390                 req.newptr = new;
 1391         }
 1392 
 1393         req.oldfunc = sysctl_old_user;
 1394         req.newfunc = sysctl_new_user;
 1395         req.lock = REQ_LOCKED;
 1396 
 1397         SYSCTL_LOCK();
 1398 
 1399         for (;;) {
 1400                 req.oldidx = 0;
 1401                 req.newidx = 0;
 1402                 error = sysctl_root(0, name, namelen, &req);
 1403                 if (error != EAGAIN)
 1404                         break;
 1405                 uio_yield();
 1406         }
 1407 
 1408         if (req.lock == REQ_WIRED && req.validlen > 0)
 1409                 vsunlock(req.oldptr, req.validlen);
 1410 
 1411         SYSCTL_UNLOCK();
 1412 
 1413         if (error && error != ENOMEM)
 1414                 return (error);
 1415 
 1416         if (retval) {
 1417                 if (req.oldptr && req.oldidx > req.validlen)
 1418                         *retval = req.validlen;
 1419                 else
 1420                         *retval = req.oldidx;
 1421         }
 1422         return (error);
 1423 }
 1424 
 1425 #ifdef COMPAT_43
 1426 #include <sys/socket.h>
 1427 #include <vm/vm_param.h>
 1428 
 1429 #define KINFO_PROC              (0<<8)
 1430 #define KINFO_RT                (1<<8)
 1431 #define KINFO_VNODE             (2<<8)
 1432 #define KINFO_FILE              (3<<8)
 1433 #define KINFO_METER             (4<<8)
 1434 #define KINFO_LOADAVG           (5<<8)
 1435 #define KINFO_CLOCKRATE         (6<<8)
 1436 
 1437 /* Non-standard BSDI extension - only present on their 4.3 net-2 releases */
 1438 #define KINFO_BSDI_SYSINFO      (101<<8)
 1439 
 1440 /*
 1441  * XXX this is bloat, but I hope it's better here than on the potentially
 1442  * limited kernel stack...  -Peter
 1443  */
 1444 
 1445 static struct {
 1446         int     bsdi_machine;           /* "i386" on BSD/386 */
 1447 /*      ^^^ this is an offset to the string, relative to the struct start */
 1448         char    *pad0;
 1449         long    pad1;
 1450         long    pad2;
 1451         long    pad3;
 1452         u_long  pad4;
 1453         u_long  pad5;
 1454         u_long  pad6;
 1455 
 1456         int     bsdi_ostype;            /* "BSD/386" on BSD/386 */
 1457         int     bsdi_osrelease;         /* "1.1" on BSD/386 */
 1458         long    pad7;
 1459         long    pad8;
 1460         char    *pad9;
 1461 
 1462         long    pad10;
 1463         long    pad11;
 1464         int     pad12;
 1465         long    pad13;
 1466         quad_t  pad14;
 1467         long    pad15;
 1468 
 1469         struct  timeval pad16;
 1470         /* we dont set this, because BSDI's uname used gethostname() instead */
 1471         int     bsdi_hostname;          /* hostname on BSD/386 */
 1472 
 1473         /* the actual string data is appended here */
 1474 
 1475 } bsdi_si;
 1476 
 1477 /*
 1478  * this data is appended to the end of the bsdi_si structure during copyout.
 1479  * The "char *" offsets are relative to the base of the bsdi_si struct.
 1480  * This contains "FreeBSD\02.0-BUILT-nnnnnn\0i386\0", and these strings
 1481  * should not exceed the length of the buffer here... (or else!! :-)
 1482  */
 1483 static char bsdi_strings[80];   /* It had better be less than this! */
 1484 
 1485 #ifndef _SYS_SYSPROTO_H_
 1486 struct getkerninfo_args {
 1487         int     op;
 1488         char    *where;
 1489         size_t  *size;
 1490         int     arg;
 1491 };
 1492 #endif
 1493 int
 1494 ogetkerninfo(struct thread *td, struct getkerninfo_args *uap)
 1495 {
 1496         int error, name[6];
 1497         size_t size;
 1498         u_int needed = 0;
 1499 
 1500         mtx_lock(&Giant);
 1501 
 1502         switch (uap->op & 0xff00) {
 1503 
 1504         case KINFO_RT:
 1505                 name[0] = CTL_NET;
 1506                 name[1] = PF_ROUTE;
 1507                 name[2] = 0;
 1508                 name[3] = (uap->op & 0xff0000) >> 16;
 1509                 name[4] = uap->op & 0xff;
 1510                 name[5] = uap->arg;
 1511                 error = userland_sysctl(td, name, 6, uap->where, uap->size,
 1512                         0, 0, 0, &size, 0);
 1513                 break;
 1514 
 1515         case KINFO_VNODE:
 1516                 name[0] = CTL_KERN;
 1517                 name[1] = KERN_VNODE;
 1518                 error = userland_sysctl(td, name, 2, uap->where, uap->size,
 1519                         0, 0, 0, &size, 0);
 1520                 break;
 1521 
 1522         case KINFO_PROC:
 1523                 name[0] = CTL_KERN;
 1524                 name[1] = KERN_PROC;
 1525                 name[2] = uap->op & 0xff;
 1526                 name[3] = uap->arg;
 1527                 error = userland_sysctl(td, name, 4, uap->where, uap->size,
 1528                         0, 0, 0, &size, 0);
 1529                 break;
 1530 
 1531         case KINFO_FILE:
 1532                 name[0] = CTL_KERN;
 1533                 name[1] = KERN_FILE;
 1534                 error = userland_sysctl(td, name, 2, uap->where, uap->size,
 1535                         0, 0, 0, &size, 0);
 1536                 break;
 1537 
 1538         case KINFO_METER:
 1539                 name[0] = CTL_VM;
 1540                 name[1] = VM_TOTAL;
 1541                 error = userland_sysctl(td, name, 2, uap->where, uap->size,
 1542                         0, 0, 0, &size, 0);
 1543                 break;
 1544 
 1545         case KINFO_LOADAVG:
 1546                 name[0] = CTL_VM;
 1547                 name[1] = VM_LOADAVG;
 1548                 error = userland_sysctl(td, name, 2, uap->where, uap->size,
 1549                         0, 0, 0, &size, 0);
 1550                 break;
 1551 
 1552         case KINFO_CLOCKRATE:
 1553                 name[0] = CTL_KERN;
 1554                 name[1] = KERN_CLOCKRATE;
 1555                 error = userland_sysctl(td, name, 2, uap->where, uap->size,
 1556                         0, 0, 0, &size, 0);
 1557                 break;
 1558 
 1559         case KINFO_BSDI_SYSINFO: {
 1560                 /*
 1561                  * this is pretty crude, but it's just enough for uname()
 1562                  * from BSDI's 1.x libc to work.
 1563                  *
 1564                  * *size gives the size of the buffer before the call, and
 1565                  * the amount of data copied after a successful call.
 1566                  * If successful, the return value is the amount of data
 1567                  * available, which can be larger than *size.
 1568                  *
 1569                  * BSDI's 2.x product apparently fails with ENOMEM if *size
 1570                  * is too small.
 1571                  */
 1572 
 1573                 u_int left;
 1574                 char *s;
 1575 
 1576                 bzero((char *)&bsdi_si, sizeof(bsdi_si));
 1577                 bzero(bsdi_strings, sizeof(bsdi_strings));
 1578 
 1579                 s = bsdi_strings;
 1580 
 1581                 bsdi_si.bsdi_ostype = (s - bsdi_strings) + sizeof(bsdi_si);
 1582                 strcpy(s, ostype);
 1583                 s += strlen(s) + 1;
 1584 
 1585                 bsdi_si.bsdi_osrelease = (s - bsdi_strings) + sizeof(bsdi_si);
 1586                 strcpy(s, osrelease);
 1587                 s += strlen(s) + 1;
 1588 
 1589                 bsdi_si.bsdi_machine = (s - bsdi_strings) + sizeof(bsdi_si);
 1590                 strcpy(s, machine);
 1591                 s += strlen(s) + 1;
 1592 
 1593                 needed = sizeof(bsdi_si) + (s - bsdi_strings);
 1594 
 1595                 if ((uap->where == NULL) || (uap->size == NULL)) {
 1596                         /* process is asking how much buffer to supply.. */
 1597                         size = needed;
 1598                         error = 0;
 1599                         break;
 1600                 }
 1601 
 1602                 if ((error = copyin(uap->size, &size, sizeof(size))) != 0)
 1603                         break;
 1604 
 1605                 /* if too much buffer supplied, trim it down */
 1606                 if (size > needed)
 1607                         size = needed;
 1608 
 1609                 /* how much of the buffer is remaining */
 1610                 left = size;
 1611 
 1612                 if ((error = copyout((char *)&bsdi_si, uap->where, left)) != 0)
 1613                         break;
 1614 
 1615                 /* is there any point in continuing? */
 1616                 if (left > sizeof(bsdi_si)) {
 1617                         left -= sizeof(bsdi_si);
 1618                         error = copyout(&bsdi_strings,
 1619                                         uap->where + sizeof(bsdi_si), left);
 1620                 }
 1621                 break;
 1622         }
 1623 
 1624         default:
 1625                 error = EOPNOTSUPP;
 1626                 break;
 1627         }
 1628         if (error == 0) {
 1629                 td->td_retval[0] = needed ? needed : size;
 1630                 if (uap->size) {
 1631                         error = copyout(&size, uap->size, sizeof(size));
 1632                 }
 1633         }
 1634         mtx_unlock(&Giant);
 1635         return (error);
 1636 }
 1637 #endif /* COMPAT_43 */
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FreeBSD/Linux Kernel Cross Reference sys/kern/kern_sysctl.c

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