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 char * 50 getenv(char *name) 51 { 52 char *cp, *ep; 53 int len; 54 55 for (cp = kern_envp; cp != NULL; cp = kernenv_next(cp)) { 56 for (ep = cp; (*ep != '=') && (*ep != 0); ep++) 57 ; 58 len = ep - cp; 59 if (*ep == '=') 60 ep++; 61 if (!strncmp(name, cp, len)) 62 return(ep); 63 } 64 return(NULL); 65 } 66 67 /* 68 * Return an integer value from an environment variable. 69 */ 70 int 71 getenv_int(char *name, int *data) 72 { 73 const char *value, *vtp; 74 quad_t iv; 75 76 if ((value = getenv(name)) == NULL) 77 return(0); 78 79 iv = strtoq(value, &vtp, 0); 80 if ((vtp == value) || (*vtp != 0)) 81 return(0); 82 83 *data = (int)iv; 84 return(1); 85 } 86 87 static int 88 sysctl_kernenv SYSCTL_HANDLER_ARGS 89 { 90 int *name = (int *)arg1; 91 u_int namelen = arg2; 92 char *cp; 93 int i, error; 94 95 if (kern_envp == NULL) 96 return(ENOENT); 97 98 name++; 99 namelen--; 100 101 if (namelen != 1) 102 return(EINVAL); 103 104 cp = kern_envp; 105 for (i = 0; i < name[0]; i++) { 106 cp = kernenv_next(cp); 107 if (cp == NULL) 108 break; 109 } 110 111 if (cp == NULL) 112 return(ENOENT); 113 114 error = SYSCTL_OUT(req, cp, strlen(cp) + 1); 115 return (error); 116 } 117 118 SYSCTL_NODE(_kern, OID_AUTO, environment, CTLFLAG_RD, sysctl_kernenv, "kernel environment space"); 119 120 /* 121 * Find the next entry after the one which (cp) falls within, return a 122 * pointer to its start or NULL if there are no more. 123 */ 124 static char * 125 kernenv_next(char *cp) 126 { 127 if (cp != NULL) { 128 while (*cp != 0) 129 cp++; 130 cp++; 131 if (*cp == 0) 132 cp = NULL; 133 } 134 return(cp); 135 } 136 137