2 * Copyright (c) 2000 Andrzej Bialecki <abial@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: src/share/examples/kld/dyn_sysctl/dyn_sysctl.c,v 1.1.2.2 2002/03/27 20:45:11 abial Exp $
27 * $DragonFly: src/share/examples/kld/dyn_sysctl/dyn_sysctl.c,v 1.2 2003/06/17 04:36:57 dillon Exp $
30 #include <sys/types.h>
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/module.h>
34 #include <sys/sysctl.h>
35 #include <sys/kernel.h>
38 /* Some example data */
41 static char *c = "hi there from dyn_sysctl";
42 static struct sysctl_oid *a_root, *a_root1, *b_root;
43 static struct sysctl_ctx_list clist, clist1, clist2;
46 sysctl_dyn_sysctl_test (SYSCTL_HANDLER_ARGS)
48 char *buf = "let's produce some text...";
50 return (sysctl_handle_string(oidp, buf, strlen(buf), req));
54 * The function called at load/unload.
57 load (module_t mod, int cmd, void *arg)
64 /* Initialize the contexts */
65 kprintf("Initializing contexts and creating subtrees.\n\n");
66 sysctl_ctx_init(&clist);
67 sysctl_ctx_init(&clist1);
68 sysctl_ctx_init(&clist2);
70 * Create two partially overlapping subtrees, belonging
71 * to different contexts.
73 kprintf("TREE ROOT NAME\n");
74 a_root = SYSCTL_ADD_NODE(&clist,
75 SYSCTL_STATIC_CHILDREN(/* top of sysctl tree */),
76 OID_AUTO, "dyn_sysctl", CTLFLAG_RW, 0,
77 "dyn_sysctl root node");
78 a_root = SYSCTL_ADD_NODE(&clist1,
79 SYSCTL_STATIC_CHILDREN(/* top of sysctl tree */),
80 OID_AUTO, "dyn_sysctl", CTLFLAG_RW, 0,
81 "dyn_sysctl root node");
83 kprintf("SYSCTL_ADD_NODE failed!\n");
86 SYSCTL_ADD_LONG(&clist, SYSCTL_CHILDREN(a_root),
87 OID_AUTO, "long_a", CTLFLAG_RW, &a, "just to try");
88 SYSCTL_ADD_INT(&clist, SYSCTL_CHILDREN(a_root),
89 OID_AUTO, "int_b", CTLFLAG_RW, &b, 0, "just to try 1");
90 a_root1=SYSCTL_ADD_NODE(&clist, SYSCTL_CHILDREN(a_root),
91 OID_AUTO, "nextlevel", CTLFLAG_RD, 0, "one level down");
92 SYSCTL_ADD_STRING(&clist, SYSCTL_CHILDREN(a_root1),
93 OID_AUTO, "string_c", CTLFLAG_RD, c, 0, "just to try 2");
94 kprintf("1. (%p) / dyn_sysctl\n", &clist);
96 /* Add a subtree under already existing category */
97 a_root1 = SYSCTL_ADD_NODE(&clist, SYSCTL_STATIC_CHILDREN(_kern),
98 OID_AUTO, "dyn_sysctl", CTLFLAG_RW, 0, "dyn_sysctl root node");
100 kprintf("SYSCTL_ADD_NODE failed!\n");
103 SYSCTL_ADD_PROC(&clist, SYSCTL_CHILDREN(a_root1),
104 OID_AUTO, "procedure", CTLFLAG_RD, 0, 0,
105 sysctl_dyn_sysctl_test, "A", "I can be here, too");
106 kprintf(" (%p) /kern dyn_sysctl\n", &clist);
108 /* Overlap second tree with the first. */
109 b_root = SYSCTL_ADD_NODE(&clist1, SYSCTL_CHILDREN(a_root),
110 OID_AUTO, "nextlevel", CTLFLAG_RD, 0, "one level down");
111 SYSCTL_ADD_STRING(&clist1, SYSCTL_CHILDREN(b_root),
112 OID_AUTO, "string_c1", CTLFLAG_RD, c, 0, "just to try 2");
113 kprintf("2. (%p) / dyn_sysctl (overlapping #1)\n", &clist1);
116 * And now do something stupid. Connect another subtree to
118 * WARNING: this is an example of WRONG use of dynamic sysctls.
120 b_root=SYSCTL_ADD_NODE(&clist2, SYSCTL_CHILDREN(a_root1),
121 OID_AUTO, "bad", CTLFLAG_RW, 0, "dependent node");
122 SYSCTL_ADD_STRING(&clist2, SYSCTL_CHILDREN(b_root),
123 OID_AUTO, "string_c", CTLFLAG_RD, c, 0, "shouldn't panic");
124 kprintf("3. (%p) /kern/dyn_sysctl bad (WRONG!)\n", &clist2);
127 kprintf("1. Try to free ctx1 (%p): ", &clist);
128 if(sysctl_ctx_free(&clist))
129 kprintf("failed: expected. Need to remove ctx3 first.\n");
131 kprintf("HELP! sysctl_ctx_free(%p) succeeded. EXPECT PANIC!!!\n", &clist);
132 kprintf("2. Try to free ctx3 (%p): ", &clist2);
133 if(sysctl_ctx_free(&clist2)) {
134 kprintf("sysctl_ctx_free(%p) failed!\n", &clist2);
135 /* Remove subtree forcefully... */
136 sysctl_remove_oid(b_root, 1, 1);
137 kprintf("sysctl_remove_oid(%p) succeeded\n", b_root);
140 kprintf("3. Try to free ctx1 (%p) again: ", &clist);
141 if(sysctl_ctx_free(&clist)) {
142 kprintf("sysctl_ctx_free(%p) failed!\n", &clist);
143 /* Remove subtree forcefully... */
144 sysctl_remove_oid(a_root1, 1, 1);
145 kprintf("sysctl_remove_oid(%p) succeeded\n", a_root1);
148 kprintf("4. Try to free ctx2 (%p): ", &clist1);
149 if(sysctl_ctx_free(&clist1)) {
150 kprintf("sysctl_ctx_free(%p) failed!\n", &clist1);
151 /* Remove subtree forcefully... */
152 sysctl_remove_oid(a_root, 1, 1);
163 static moduledata_t mod_data= {
169 DECLARE_MODULE(dyn_sysctl, mod_data, SI_SUB_EXEC, SI_ORDER_ANY);