1 /*- 2 * Copyright (c) 2000 Andrzej Bialecki <abial@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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. 13 * 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 24 * SUCH DAMAGE. 25 * 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 $ 28 */ 29 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> 36 37 38 /* Some example data */ 39 static long a = 100; 40 static int b = 200; 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; 44 45 static int 46 sysctl_dyn_sysctl_test (SYSCTL_HANDLER_ARGS) 47 { 48 char *buf = "let's produce some text..."; 49 50 return (sysctl_handle_string(oidp, buf, strlen(buf), req)); 51 } 52 53 /* 54 * The function called at load/unload. 55 */ 56 static int 57 load (module_t mod, int cmd, void *arg) 58 { 59 int error; 60 61 error = 0; 62 switch (cmd) { 63 case MOD_LOAD : 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); 69 /* 70 * Create two partially overlapping subtrees, belonging 71 * to different contexts. 72 */ 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"); 82 if(a_root == NULL) { 83 kprintf("SYSCTL_ADD_NODE failed!\n"); 84 return (EINVAL); 85 } 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); 95 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"); 99 if(a_root1 == NULL) { 100 kprintf("SYSCTL_ADD_NODE failed!\n"); 101 return (EINVAL); 102 } 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); 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 kprintf("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 kprintf("3. (%p) /kern/dyn_sysctl bad (WRONG!)\n", &clist2); 125 break; 126 case MOD_UNLOAD : 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"); 130 else 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); 138 } else 139 kprintf("Ok\n"); 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); 146 } else 147 kprintf("Ok\n"); 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); 153 } else 154 kprintf("Ok\n"); 155 break; 156 default : 157 error = EINVAL; 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