1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-NetBSD 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 * $FreeBSD$ 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 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 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