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 * $Id: kern_environment.c,v 1.2 1998/10/09 11:03:46 jkh Exp $ 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 #include <machine/bootinfo.h> 45 46 char *kern_envp; 47 48 static char *kernenv_next(char *cp); 49 50 char * 51 getenv(char *name) 52 { 53 char *cp, *ep; 54 int len; 55 56 for (cp = kern_envp; cp != NULL; cp = kernenv_next(cp)) { 57 for (ep = cp; (*ep != '=') && (*ep != 0); ep++) 58 ; 59 len = ep - cp; 60 if (*ep = '=') 61 ep++; 62 if (!strncmp(name, cp, len)) 63 return(ep); 64 } 65 return(NULL); 66 } 67 68 69 static int 70 sysctl_kernenv SYSCTL_HANDLER_ARGS 71 { 72 int *name = (int *)arg1; 73 u_int namelen = arg2; 74 char *cp; 75 int i, error; 76 77 if (kern_envp == NULL) 78 return(ENOENT); 79 80 name++; 81 namelen--; 82 83 if (namelen != 1) 84 return(EINVAL); 85 86 cp = kern_envp; 87 for (i = 0; i < name[0]; i++) { 88 cp = kernenv_next(cp); 89 if (cp == NULL) 90 break; 91 } 92 93 if (cp == NULL) 94 return(ENOENT); 95 96 error = SYSCTL_OUT(req, cp, strlen(cp) + 1); 97 return (error); 98 } 99 100 SYSCTL_NODE(_kern, OID_AUTO, environment, CTLFLAG_RD, sysctl_kernenv, "kernel environment space"); 101 102 /* 103 * Find the next entry after the one which (cp) falls within, return a 104 * pointer to its start or NULL if there are no more. 105 */ 106 static char * 107 kernenv_next(char *cp) 108 { 109 if (cp != NULL) { 110 while (*cp != 0) 111 cp++; 112 cp++; 113 if (*cp == 0) 114 cp = NULL; 115 } 116 return(cp); 117 } 118 119