1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2000 Andrzej Bialecki <abial@freebsd.org>
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
29 #include <sys/types.h>
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/module.h>
33 #include <sys/sysctl.h>
34 #include <sys/kernel.h>
35
36
37 /* Some example data */
38 static long a = 100;
39 static int b = 200;
40 static char *c = "hi there from dyn_sysctl";
41 static struct sysctl_oid *a_root, *a_root1, *b_root;
42 static struct sysctl_ctx_list clist, clist1, clist2;
43
44 static int
sysctl_dyn_sysctl_test(SYSCTL_HANDLER_ARGS)45 sysctl_dyn_sysctl_test(SYSCTL_HANDLER_ARGS)
46 {
47 char *buf = "let's produce some text...";
48
49 return (sysctl_handle_string(oidp, buf, strlen(buf), req));
50 }
51
52 /*
53 * The function called at load/unload.
54 */
55 static int
load(module_t mod,int cmd,void * arg)56 load(module_t mod, int cmd, void *arg)
57 {
58 int error;
59
60 error = 0;
61 switch (cmd) {
62 case MOD_LOAD:
63 /* Initialize the contexts */
64 printf("Initializing contexts and creating subtrees.\n\n");
65 sysctl_ctx_init(&clist);
66 sysctl_ctx_init(&clist1);
67 sysctl_ctx_init(&clist2);
68 /*
69 * Create two partially overlapping subtrees, belonging
70 * to different contexts.
71 */
72 printf("TREE ROOT NAME\n");
73 a_root = SYSCTL_ADD_ROOT_NODE(&clist,
74 OID_AUTO, "dyn_sysctl", CTLFLAG_RW, 0,
75 "dyn_sysctl root node");
76 a_root = SYSCTL_ADD_ROOT_NODE(&clist1,
77 OID_AUTO, "dyn_sysctl", CTLFLAG_RW, 0,
78 "dyn_sysctl root node");
79 if (a_root == NULL) {
80 printf("SYSCTL_ADD_NODE failed!\n");
81 return (EINVAL);
82 }
83 SYSCTL_ADD_LONG(&clist, SYSCTL_CHILDREN(a_root),
84 OID_AUTO, "long_a", CTLFLAG_RW, &a, "just to try");
85 SYSCTL_ADD_INT(&clist, SYSCTL_CHILDREN(a_root),
86 OID_AUTO, "int_b", CTLFLAG_RW, &b, 0, "just to try 1");
87 a_root1 = SYSCTL_ADD_NODE(&clist, SYSCTL_CHILDREN(a_root),
88 OID_AUTO, "nextlevel", CTLFLAG_RD, 0, "one level down");
89 SYSCTL_ADD_STRING(&clist, SYSCTL_CHILDREN(a_root1),
90 OID_AUTO, "string_c", CTLFLAG_RD, c, 0, "just to try 2");
91 printf("1. (%p) / dyn_sysctl\n", &clist);
92
93 /* Add a subtree under already existing category */
94 a_root1 = SYSCTL_ADD_NODE(&clist, SYSCTL_STATIC_CHILDREN(_kern),
95 OID_AUTO, "dyn_sysctl", CTLFLAG_RW, 0, "dyn_sysctl root node");
96 if (a_root1 == NULL) {
97 printf("SYSCTL_ADD_NODE failed!\n");
98 return (EINVAL);
99 }
100 SYSCTL_ADD_PROC(&clist, SYSCTL_CHILDREN(a_root1),
101 OID_AUTO, "procedure", CTLTYPE_STRING | CTLFLAG_RD,
102 NULL, 0, sysctl_dyn_sysctl_test, "A",
103 "I can be here, too");
104 printf(" (%p) /kern dyn_sysctl\n", &clist);
105
106 /* Overlap second tree with the first. */
107 b_root = SYSCTL_ADD_NODE(&clist1, SYSCTL_CHILDREN(a_root),
108 OID_AUTO, "nextlevel", CTLFLAG_RD, 0, "one level down");
109 SYSCTL_ADD_STRING(&clist1, SYSCTL_CHILDREN(b_root),
110 OID_AUTO, "string_c1", CTLFLAG_RD, c, 0, "just to try 2");
111 printf("2. (%p) / dyn_sysctl (overlapping #1)\n", &clist1);
112
113 /*
114 * And now do something stupid. Connect another subtree to
115 * dynamic oid.
116 * WARNING: this is an example of WRONG use of dynamic sysctls.
117 */
118 b_root=SYSCTL_ADD_NODE(&clist2, SYSCTL_CHILDREN(a_root1),
119 OID_AUTO, "bad", CTLFLAG_RW, 0, "dependent node");
120 SYSCTL_ADD_STRING(&clist2, SYSCTL_CHILDREN(b_root),
121 OID_AUTO, "string_c", CTLFLAG_RD, c, 0, "shouldn't panic");
122 printf("3. (%p) /kern/dyn_sysctl bad (WRONG!)\n", &clist2);
123 break;
124 case MOD_UNLOAD:
125 printf("1. Try to free ctx1 (%p): ", &clist);
126 if (sysctl_ctx_free(&clist) != 0)
127 printf("failed: expected. Need to remove ctx3 first.\n");
128 else
129 printf("HELP! sysctl_ctx_free(%p) succeeded. EXPECT PANIC!!!\n", &clist);
130 printf("2. Try to free ctx3 (%p): ", &clist2);
131 if (sysctl_ctx_free(&clist2) != 0) {
132 printf("sysctl_ctx_free(%p) failed!\n", &clist2);
133 /* Remove subtree forcefully... */
134 sysctl_remove_oid(b_root, 1, 1);
135 printf("sysctl_remove_oid(%p) succeeded\n", b_root);
136 } else
137 printf("Ok\n");
138 printf("3. Try to free ctx1 (%p) again: ", &clist);
139 if (sysctl_ctx_free(&clist) != 0) {
140 printf("sysctl_ctx_free(%p) failed!\n", &clist);
141 /* Remove subtree forcefully... */
142 sysctl_remove_oid(a_root1, 1, 1);
143 printf("sysctl_remove_oid(%p) succeeded\n", a_root1);
144 } else
145 printf("Ok\n");
146 printf("4. Try to free ctx2 (%p): ", &clist1);
147 if (sysctl_ctx_free(&clist1) != 0) {
148 printf("sysctl_ctx_free(%p) failed!\n", &clist1);
149 /* Remove subtree forcefully... */
150 sysctl_remove_oid(a_root, 1, 1);
151 } else
152 printf("Ok\n");
153 break;
154 default:
155 error = EOPNOTSUPP;
156 break;
157 }
158 return (error);
159 }
160
161 static moduledata_t mod_data = {
162 "dyn_sysctl",
163 load,
164 0
165 };
166
167 DECLARE_MODULE(dyn_sysctl, mod_data, SI_SUB_EXEC, SI_ORDER_ANY);
168