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