1 /* $NetBSD: expand.c,v 1.6 2013/05/06 08:02:20 skrll Exp $ */ 2 3 /*- 4 * Copyright (c) 2007 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 #include <sys/cdefs.h> 32 #ifndef lint 33 __RCSID("$NetBSD: expand.c,v 1.6 2013/05/06 08:02:20 skrll Exp $"); 34 #endif /* not lint */ 35 36 #include <ctype.h> 37 #include <string.h> 38 #include <sys/sysctl.h> 39 40 #ifdef DEBUG_EXPAND 41 #include <stdio.h> 42 #include <err.h> 43 #define xwarn warn 44 #define xerr err 45 size_t _rtld_expand_path(char *, size_t, const char *, const char *, 46 const char *); 47 #else 48 #include <sys/stat.h> 49 #include "rtld.h" 50 #endif 51 52 static const struct { 53 const char *name; 54 size_t namelen; 55 } bltn[] = { 56 #define ADD(a) { #a, sizeof(#a) - 1 }, 57 ADD(HWCAP) /* SSE, MMX, etc */ 58 ADD(ISALIST) /* XXX */ 59 ADD(ORIGIN) /* dirname argv[0] */ 60 ADD(OSNAME) /* uname -s */ 61 ADD(OSREL) /* uname -r */ 62 ADD(PLATFORM) /* uname -p */ 63 }; 64 65 #if !defined(__minix) 66 static int mib[3][2] = { 67 { CTL_KERN, KERN_OSTYPE }, 68 { CTL_KERN, KERN_OSRELEASE }, 69 { CTL_HW, HW_MACHINE_ARCH }, 70 }; 71 #endif /* !defined(__minix) */ 72 73 static size_t 74 expand(char *buf, const char *execname, int what, size_t bl) 75 { 76 const char *p, *ep; 77 char *bp = buf; 78 #if !defined(__minix) 79 size_t len; 80 char name[32]; 81 #endif /* !defined(__minix) */ 82 83 switch (what) { 84 case 0: /* HWCAP XXX: Not yet */ 85 case 1: /* ISALIST XXX: Not yet */ 86 return 0; 87 88 case 2: /* ORIGIN */ 89 if (execname == NULL) 90 xerr(1, "execname not specified in AUX vector"); 91 if ((ep = strrchr(p = execname, '/')) == NULL) 92 xerr(1, "bad execname `%s' in AUX vector", execname); 93 break; 94 95 #if !defined(__minix) 96 case 3: /* OSNAME */ 97 case 4: /* OSREL */ 98 case 5: /* PLATFORM */ 99 len = sizeof(name); 100 if (sysctl(mib[what - 3], 2, name, &len, NULL, 0) == -1) { 101 xwarn("sysctl"); 102 return 0; 103 } 104 ep = (p = name) + len - 1; 105 break; 106 #endif /* !defined(__minix) */ 107 default: 108 return 0; 109 } 110 111 while (p != ep && bl) 112 *bp++ = *p++, bl--; 113 114 return bp - buf; 115 } 116 117 118 size_t 119 _rtld_expand_path(char *buf, size_t bufsize, const char *execname, 120 const char *bp, const char *ep) 121 { 122 size_t i, ds = bufsize; 123 char *dp = buf; 124 const char *p; 125 int br; 126 127 for (p = bp; p < ep;) { 128 if (*p == '$') { 129 br = *++p == '{'; 130 131 if (br) 132 p++; 133 134 for (i = 0; i < sizeof(bltn) / sizeof(bltn[0]); i++) { 135 size_t s = bltn[i].namelen; 136 const char *es = p + s; 137 138 if ((br && *es != '}') || 139 (!br && (es != ep && 140 isalpha((unsigned char)*es)))) 141 continue; 142 143 if (strncmp(bltn[i].name, p, s) == 0) { 144 size_t ls = expand(dp, execname, i, ds); 145 if (ls >= ds) 146 return bufsize; 147 ds -= ls; 148 dp += ls; 149 p = es + br; 150 goto done; 151 } 152 } 153 p -= br + 1; 154 155 } 156 *dp++ = *p++; 157 ds--; 158 done:; 159 } 160 *dp = '\0'; 161 return dp - buf; 162 } 163 164 #ifdef DEBUG_EXPAND 165 int 166 main(int argc, char *argv[]) 167 { 168 char buf[1024]; 169 size_t i; 170 171 for (i = 1; i < argc; i++) { 172 char *p = argv[i], *ep = argv[i] + strlen(p); 173 size_t n = _rtld_expand_path(buf, sizeof(buf), argv[0], p, ep); 174 printf("%s\n", buf); 175 } 176 return 0; 177 } 178 #endif 179