/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2000 Andrzej Bialecki <abial@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <sys/kernel.h>
/* Some example data */
static long a = 100;
static int b = 200;
static char *c = "hi there from dyn_sysctl";
static struct sysctl_oid *a_root, *a_root1, *b_root;
static struct sysctl_ctx_list clist, clist1, clist2;
static int
sysctl_dyn_sysctl_test(SYSCTL_HANDLER_ARGS)
{
char *buf = "let's produce some text...";
return (sysctl_handle_string(oidp, buf, strlen(buf), req));
}
/*
* The function called at load/unload.
*/
static int
load(module_t mod, int cmd, void *arg)
{
int error;
error = 0;
switch (cmd) {
case MOD_LOAD:
/* Initialize the contexts */
printf("Initializing contexts and creating subtrees.\n\n");
sysctl_ctx_init(&clist);
sysctl_ctx_init(&clist1);
sysctl_ctx_init(&clist2);
/*
* Create two partially overlapping subtrees, belonging
* to different contexts.
*/
printf("TREE ROOT NAME\n");
a_root = SYSCTL_ADD_ROOT_NODE(&clist,
OID_AUTO, "dyn_sysctl", CTLFLAG_RW, 0,
"dyn_sysctl root node");
a_root = SYSCTL_ADD_ROOT_NODE(&clist1,
OID_AUTO, "dyn_sysctl", CTLFLAG_RW, 0,
"dyn_sysctl root node");
if (a_root == NULL) {
printf("SYSCTL_ADD_NODE failed!\n");
return (EINVAL);
}
SYSCTL_ADD_LONG(&clist, SYSCTL_CHILDREN(a_root),
OID_AUTO, "long_a", CTLFLAG_RW, &a, "just to try");
SYSCTL_ADD_INT(&clist, SYSCTL_CHILDREN(a_root),
OID_AUTO, "int_b", CTLFLAG_RW, &b, 0, "just to try 1");
a_root1 = SYSCTL_ADD_NODE(&clist, SYSCTL_CHILDREN(a_root),
OID_AUTO, "nextlevel", CTLFLAG_RD, 0, "one level down");
SYSCTL_ADD_STRING(&clist, SYSCTL_CHILDREN(a_root1),
OID_AUTO, "string_c", CTLFLAG_RD, c, 0, "just to try 2");
printf("1. (%p) / dyn_sysctl\n", &clist);
/* Add a subtree under already existing category */
a_root1 = SYSCTL_ADD_NODE(&clist, SYSCTL_STATIC_CHILDREN(_kern),
OID_AUTO, "dyn_sysctl", CTLFLAG_RW, 0, "dyn_sysctl root node");
if (a_root1 == NULL) {
printf("SYSCTL_ADD_NODE failed!\n");
return (EINVAL);
}
SYSCTL_ADD_PROC(&clist, SYSCTL_CHILDREN(a_root1),
OID_AUTO, "procedure", CTLTYPE_STRING | CTLFLAG_RD,
NULL, 0, sysctl_dyn_sysctl_test, "A",
"I can be here, too");
printf(" (%p) /kern dyn_sysctl\n", &clist);
/* Overlap second tree with the first. */
b_root = SYSCTL_ADD_NODE(&clist1, SYSCTL_CHILDREN(a_root),
OID_AUTO, "nextlevel", CTLFLAG_RD, 0, "one level down");
SYSCTL_ADD_STRING(&clist1, SYSCTL_CHILDREN(b_root),
OID_AUTO, "string_c1", CTLFLAG_RD, c, 0, "just to try 2");
printf("2. (%p) / dyn_sysctl (overlapping #1)\n", &clist1);
/*
* And now do something stupid. Connect another subtree to
* dynamic oid.
* WARNING: this is an example of WRONG use of dynamic sysctls.
*/
b_root=SYSCTL_ADD_NODE(&clist2, SYSCTL_CHILDREN(a_root1),
OID_AUTO, "bad", CTLFLAG_RW, 0, "dependent node");
SYSCTL_ADD_STRING(&clist2, SYSCTL_CHILDREN(b_root),
OID_AUTO, "string_c", CTLFLAG_RD, c, 0, "shouldn't panic");
printf("3. (%p) /kern/dyn_sysctl bad (WRONG!)\n", &clist2);
break;
case MOD_UNLOAD:
printf("1. Try to free ctx1 (%p): ", &clist);
if (sysctl_ctx_free(&clist) != 0)
printf("failed: expected. Need to remove ctx3 first.\n");
else
printf("HELP! sysctl_ctx_free(%p) succeeded. EXPECT PANIC!!!\n", &clist);
printf("2. Try to free ctx3 (%p): ", &clist2);
if (sysctl_ctx_free(&clist2) != 0) {
printf("sysctl_ctx_free(%p) failed!\n", &clist2);
/* Remove subtree forcefully... */
sysctl_remove_oid(b_root, 1, 1);
printf("sysctl_remove_oid(%p) succeeded\n", b_root);
} else
printf("Ok\n");
printf("3. Try to free ctx1 (%p) again: ", &clist);
if (sysctl_ctx_free(&clist) != 0) {
printf("sysctl_ctx_free(%p) failed!\n", &clist);
/* Remove subtree forcefully... */
sysctl_remove_oid(a_root1, 1, 1);
printf("sysctl_remove_oid(%p) succeeded\n", a_root1);
} else
printf("Ok\n");
printf("4. Try to free ctx2 (%p): ", &clist1);
if (sysctl_ctx_free(&clist1) != 0) {
printf("sysctl_ctx_free(%p) failed!\n", &clist1);
/* Remove subtree forcefully... */
sysctl_remove_oid(a_root, 1, 1);
} else
printf("Ok\n");
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
static moduledata_t mod_data = {
"dyn_sysctl",
load,
0
};
DECLARE_MODULE(dyn_sysctl, mod_data, SI_SUB_EXEC, SI_ORDER_ANY);
plain