1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-NetBSD
3 *
4 * Copyright (c) 2000 Andrzej Bialecki <[email protected]>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31 #include <sys/types.h>
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/module.h>
35 #include <sys/sysctl.h>
36 #include <sys/kernel.h>
37
38
39 /* Some example data */
40 static long a = 100;
41 static int b = 200;
42 static char *c = "hi there from dyn_sysctl";
43 static struct sysctl_oid *a_root, *a_root1, *b_root;
44 static struct sysctl_ctx_list clist, clist1, clist2;
45
46 static int
sysctl_dyn_sysctl_test(SYSCTL_HANDLER_ARGS)47 sysctl_dyn_sysctl_test(SYSCTL_HANDLER_ARGS)
48 {
49 char *buf = "let's produce some text...";
50
51 return (sysctl_handle_string(oidp, buf, strlen(buf), req));
52 }
53
54 /*
55 * The function called at load/unload.
56 */
57 static int
load(module_t mod,int cmd,void * arg)58 load(module_t mod, int cmd, void *arg)
59 {
60 int error;
61
62 error = 0;
63 switch (cmd) {
64 case MOD_LOAD:
65 /* Initialize the contexts */
66 printf("Initializing contexts and creating subtrees.\n\n");
67 sysctl_ctx_init(&clist);
68 sysctl_ctx_init(&clist1);
69 sysctl_ctx_init(&clist2);
70 /*
71 * Create two partially overlapping subtrees, belonging
72 * to different contexts.
73 */
74 printf("TREE ROOT NAME\n");
75 a_root = SYSCTL_ADD_ROOT_NODE(&clist,
76 OID_AUTO, "dyn_sysctl", CTLFLAG_RW, 0,
77 "dyn_sysctl root node");
78 a_root = SYSCTL_ADD_ROOT_NODE(&clist1,
79 OID_AUTO, "dyn_sysctl", CTLFLAG_RW, 0,
80 "dyn_sysctl root node");
81 if (a_root == NULL) {
82 printf("SYSCTL_ADD_NODE failed!\n");
83 return (EINVAL);
84 }
85 SYSCTL_ADD_LONG(&clist, SYSCTL_CHILDREN(a_root),
86 OID_AUTO, "long_a", CTLFLAG_RW, &a, "just to try");
87 SYSCTL_ADD_INT(&clist, SYSCTL_CHILDREN(a_root),
88 OID_AUTO, "int_b", CTLFLAG_RW, &b, 0, "just to try 1");
89 a_root1 = SYSCTL_ADD_NODE(&clist, SYSCTL_CHILDREN(a_root),
90 OID_AUTO, "nextlevel", CTLFLAG_RD, 0, "one level down");
91 SYSCTL_ADD_STRING(&clist, SYSCTL_CHILDREN(a_root1),
92 OID_AUTO, "string_c", CTLFLAG_RD, c, 0, "just to try 2");
93 printf("1. (%p) / dyn_sysctl\n", &clist);
94
95 /* Add a subtree under already existing category */
96 a_root1 = SYSCTL_ADD_NODE(&clist, SYSCTL_STATIC_CHILDREN(_kern),
97 OID_AUTO, "dyn_sysctl", CTLFLAG_RW, 0, "dyn_sysctl root node");
98 if (a_root1 == NULL) {
99 printf("SYSCTL_ADD_NODE failed!\n");
100 return (EINVAL);
101 }
102 SYSCTL_ADD_PROC(&clist, SYSCTL_CHILDREN(a_root1),
103 OID_AUTO, "procedure", CTLTYPE_STRING | CTLFLAG_RD,
104 NULL, 0, sysctl_dyn_sysctl_test, "A",
105 "I can be here, too");
106 printf(" (%p) /kern dyn_sysctl\n", &clist);
107
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 printf("2. (%p) / dyn_sysctl (overlapping #1)\n", &clist1);
114
115 /*
116 * And now do something stupid. Connect another subtree to
117 * dynamic oid.
118 * WARNING: this is an example of WRONG use of dynamic sysctls.
119 */
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 printf("3. (%p) /kern/dyn_sysctl bad (WRONG!)\n", &clist2);
125 break;
126 case MOD_UNLOAD:
127 printf("1. Try to free ctx1 (%p): ", &clist);
128 if (sysctl_ctx_free(&clist) != 0)
129 printf("failed: expected. Need to remove ctx3 first.\n");
130 else
131 printf("HELP! sysctl_ctx_free(%p) succeeded. EXPECT PANIC!!!\n", &clist);
132 printf("2. Try to free ctx3 (%p): ", &clist2);
133 if (sysctl_ctx_free(&clist2) != 0) {
134 printf("sysctl_ctx_free(%p) failed!\n", &clist2);
135 /* Remove subtree forcefully... */
136 sysctl_remove_oid(b_root, 1, 1);
137 printf("sysctl_remove_oid(%p) succeeded\n", b_root);
138 } else
139 printf("Ok\n");
140 printf("3. Try to free ctx1 (%p) again: ", &clist);
141 if (sysctl_ctx_free(&clist) != 0) {
142 printf("sysctl_ctx_free(%p) failed!\n", &clist);
143 /* Remove subtree forcefully... */
144 sysctl_remove_oid(a_root1, 1, 1);
145 printf("sysctl_remove_oid(%p) succeeded\n", a_root1);
146 } else
147 printf("Ok\n");
148 printf("4. Try to free ctx2 (%p): ", &clist1);
149 if (sysctl_ctx_free(&clist1) != 0) {
150 printf("sysctl_ctx_free(%p) failed!\n", &clist1);
151 /* Remove subtree forcefully... */
152 sysctl_remove_oid(a_root, 1, 1);
153 } else
154 printf("Ok\n");
155 break;
156 default:
157 error = EOPNOTSUPP;
158 break;
159 }
160 return (error);
161 }
162
163 static moduledata_t mod_data = {
164 "dyn_sysctl",
165 load,
166 0
167 };
168
169 DECLARE_MODULE(dyn_sysctl, mod_data, SI_SUB_EXEC, SI_ORDER_ANY);
170