1 /*- 2 * Copyright (c) 1998 Michael Smith 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/sys/kern/kern_environment.c,v 1.10.2.7 2002/05/07 09:57:16 bde Exp $ 27 * $DragonFly: src/sys/kern/kern_environment.c,v 1.2 2003/06/17 04:28:41 dillon Exp $ 28 */ 29 30 /* 31 * The unified bootloader passes us a pointer to a preserved copy of 32 * bootstrap/kernel environment variables. 33 * We make these available using sysctl for both in-kernel and 34 * out-of-kernel consumers. 35 * 36 * Note that the current sysctl infrastructure doesn't allow 37 * dynamic insertion or traversal through handled spaces. Grr. 38 */ 39 40 #include <sys/param.h> 41 #include <sys/kernel.h> 42 #include <sys/systm.h> 43 #include <sys/sysctl.h> 44 #include <sys/libkern.h> 45 46 char *kern_envp; 47 48 static char *kernenv_next(char *cp); 49 50 /* 51 * Look up an environment variable by name. 52 */ 53 char * 54 getenv(const char *name) 55 { 56 char *cp, *ep; 57 int len; 58 59 for (cp = kern_envp; cp != NULL; cp = kernenv_next(cp)) { 60 for (ep = cp; (*ep != '=') && (*ep != 0); ep++) 61 ; 62 if (*ep != '=') 63 continue; 64 len = ep - cp; 65 ep++; 66 if (!strncmp(name, cp, len) && name[len] == 0) 67 return(ep); 68 } 69 return(NULL); 70 } 71 72 /* 73 * Return a string value from an environment variable. 74 */ 75 int 76 getenv_string(const char *name, char *data, int size) 77 { 78 char *tmp; 79 80 tmp = getenv(name); 81 if (tmp != NULL) { 82 strncpy(data, tmp, size); 83 data[size - 1] = 0; 84 return (1); 85 } else 86 return (0); 87 } 88 89 /* 90 * Return an integer value from an environment variable. 91 */ 92 int 93 getenv_int(const char *name, int *data) 94 { 95 quad_t tmp; 96 int rval; 97 98 rval = getenv_quad(name, &tmp); 99 if (rval) { 100 *data = (int) tmp; 101 } 102 return (rval); 103 } 104 105 /* 106 * Return a quad_t value from an environment variable. 107 */ 108 int 109 getenv_quad(const char *name, quad_t *data) 110 { 111 const char *value; 112 char *vtp; 113 quad_t iv; 114 115 if ((value = getenv(name)) == NULL) 116 return(0); 117 118 iv = strtoq(value, &vtp, 0); 119 if ((vtp == value) || (*vtp != '\0')) 120 return(0); 121 122 *data = iv; 123 return(1); 124 } 125 126 static int 127 sysctl_kernenv(SYSCTL_HANDLER_ARGS) 128 { 129 int *name = (int *)arg1; 130 u_int namelen = arg2; 131 char *cp; 132 int i, error; 133 134 if (kern_envp == NULL) 135 return(ENOENT); 136 137 name++; 138 namelen--; 139 140 if (namelen != 1) 141 return(EINVAL); 142 143 cp = kern_envp; 144 for (i = 0; i < name[0]; i++) { 145 cp = kernenv_next(cp); 146 if (cp == NULL) 147 break; 148 } 149 150 if (cp == NULL) 151 return(ENOENT); 152 153 error = SYSCTL_OUT(req, cp, strlen(cp) + 1); 154 return (error); 155 } 156 157 SYSCTL_NODE(_kern, OID_AUTO, environment, CTLFLAG_RD, sysctl_kernenv, "kernel environment space"); 158 159 /* 160 * Find the next entry after the one which (cp) falls within, return a 161 * pointer to its start or NULL if there are no more. 162 */ 163 static char * 164 kernenv_next(char *cp) 165 { 166 if (cp != NULL) { 167 while (*cp != 0) 168 cp++; 169 cp++; 170 if (*cp == 0) 171 cp = NULL; 172 } 173 return(cp); 174 } 175 176 void 177 tunable_int_init(void *data) 178 { 179 struct tunable_int *d = (struct tunable_int *)data; 180 181 TUNABLE_INT_FETCH(d->path, d->var); 182 } 183 184 void 185 tunable_quad_init(void *data) 186 { 187 struct tunable_quad *d = (struct tunable_quad *)data; 188 189 TUNABLE_QUAD_FETCH(d->path, d->var); 190 } 191 192 void 193 tunable_str_init(void *data) 194 { 195 struct tunable_str *d = (struct tunable_str *)data; 196 197 TUNABLE_STR_FETCH(d->path, d->var, d->size); 198 } 199 200