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 static int mib[3][2] = {
66 { CTL_KERN, KERN_OSTYPE },
67 { CTL_KERN, KERN_OSRELEASE },
68 { CTL_HW, HW_MACHINE_ARCH },
69 };
70
71 static size_t
expand(char * buf,const char * execname,int what,size_t bl)72 expand(char *buf, const char *execname, int what, size_t bl)
73 {
74 const char *p, *ep;
75 char *bp = buf;
76 size_t len;
77 char name[32];
78
79 switch (what) {
80 case 0: /* HWCAP XXX: Not yet */
81 case 1: /* ISALIST XXX: Not yet */
82 return 0;
83
84 case 2: /* ORIGIN */
85 if (execname == NULL)
86 xerr(1, "execname not specified in AUX vector");
87 if ((ep = strrchr(p = execname, '/')) == NULL)
88 xerr(1, "bad execname `%s' in AUX vector", execname);
89 break;
90
91 case 3: /* OSNAME */
92 case 4: /* OSREL */
93 case 5: /* PLATFORM */
94 len = sizeof(name);
95 if (sysctl(mib[what - 3], 2, name, &len, NULL, 0) == -1) {
96 xwarn("sysctl");
97 return 0;
98 }
99 ep = (p = name) + len - 1;
100 break;
101 default:
102 return 0;
103 }
104
105 while (p != ep && bl)
106 *bp++ = *p++, bl--;
107
108 return bp - buf;
109 }
110
111
112 size_t
_rtld_expand_path(char * buf,size_t bufsize,const char * execname,const char * bp,const char * ep)113 _rtld_expand_path(char *buf, size_t bufsize, const char *execname,
114 const char *bp, const char *ep)
115 {
116 size_t i, ds = bufsize;
117 char *dp = buf;
118 const char *p;
119 int br;
120
121 for (p = bp; p < ep;) {
122 if (*p == '$') {
123 br = *++p == '{';
124
125 if (br)
126 p++;
127
128 for (i = 0; i < sizeof(bltn) / sizeof(bltn[0]); i++) {
129 size_t s = bltn[i].namelen;
130 const char *es = p + s;
131
132 if ((br && *es != '}') ||
133 (!br && (es != ep &&
134 isalpha((unsigned char)*es))))
135 continue;
136
137 if (strncmp(bltn[i].name, p, s) == 0) {
138 size_t ls = expand(dp, execname, i, ds);
139 if (ls >= ds)
140 return bufsize;
141 ds -= ls;
142 dp += ls;
143 p = es + br;
144 goto done;
145 }
146 }
147 p -= br + 1;
148
149 }
150 *dp++ = *p++;
151 ds--;
152 done:;
153 }
154 *dp = '\0';
155 return dp - buf;
156 }
157
158 #ifdef DEBUG_EXPAND
159 int
main(int argc,char * argv[])160 main(int argc, char *argv[])
161 {
162 char buf[1024];
163 size_t i;
164
165 for (i = 1; i < argc; i++) {
166 char *p = argv[i], *ep = argv[i] + strlen(p);
167 size_t n = _rtld_expand_path(buf, sizeof(buf), argv[0], p, ep);
168 printf("%s\n", buf);
169 }
170 return 0;
171 }
172 #endif
173