1 /*-
2 * Copyright (c) 2000, 2001 David O'Brien
3 * Copyright (c) 1996 Søren Schmidt
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer
11 * in this position and unchanged.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32
33 #include <sys/types.h>
34 #include <sys/elf_common.h>
35 #include <sys/errno.h>
36 #include <err.h>
37 #include <fcntl.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42
43 static int elftype(const char *);
44 static const char *iselftype(int);
45 static void printelftypes(void);
46 static void usage(void);
47
48 struct ELFtypes {
49 const char *str;
50 int value;
51 };
52 /* XXX - any more types? */
53 static struct ELFtypes elftypes[] = {
54 { "FreeBSD", ELFOSABI_FREEBSD },
55 { "Linux", ELFOSABI_LINUX },
56 { "Solaris", ELFOSABI_SOLARIS },
57 { "SVR4", ELFOSABI_SYSV }
58 };
59
60 int
main(int argc,char ** argv)61 main(int argc, char **argv)
62 {
63
64 const char *strtype = "FreeBSD";
65 int type = ELFOSABI_FREEBSD;
66 int retval = 0;
67 int ch, change = 0, force = 0, listed = 0;
68
69 while ((ch = getopt(argc, argv, "f:lt:v")) != -1)
70 switch (ch) {
71 case 'f':
72 if (change)
73 errx(1, "f option incompatible with t option");
74 force = 1;
75 type = atoi(optarg);
76 if (errno == ERANGE || type < 0 || type > 255) {
77 warnx("invalid argument to option f: %s",
78 optarg);
79 usage();
80 }
81 break;
82 case 'l':
83 printelftypes();
84 listed = 1;
85 break;
86 case 'v':
87 /* does nothing */
88 break;
89 case 't':
90 if (force)
91 errx(1, "t option incompatible with f option");
92 change = 1;
93 strtype = optarg;
94 break;
95 default:
96 usage();
97 }
98 argc -= optind;
99 argv += optind;
100 if (!argc) {
101 if (listed)
102 exit(0);
103 else {
104 warnx("no file(s) specified");
105 usage();
106 }
107 }
108
109 if (!force && (type = elftype(strtype)) == -1) {
110 warnx("invalid ELF type '%s'", strtype);
111 printelftypes();
112 usage();
113 }
114
115 while (argc) {
116 int fd;
117 char buffer[EI_NIDENT];
118
119 if ((fd = open(argv[0], change || force ? O_RDWR : O_RDONLY, 0)) < 0) {
120 warn("error opening file %s", argv[0]);
121 retval = 1;
122 goto fail;
123 }
124 if (read(fd, buffer, EI_NIDENT) < EI_NIDENT) {
125 warnx("file '%s' too short", argv[0]);
126 retval = 1;
127 goto fail;
128 }
129 if (buffer[0] != ELFMAG0 || buffer[1] != ELFMAG1 ||
130 buffer[2] != ELFMAG2 || buffer[3] != ELFMAG3) {
131 warnx("file '%s' is not ELF format", argv[0]);
132 retval = 1;
133 goto fail;
134 }
135 if (!change && !force) {
136 fprintf(stdout,
137 "File '%s' is of brand '%s' (%u).\n",
138 argv[0], iselftype(buffer[EI_OSABI]),
139 buffer[EI_OSABI]);
140 if (!iselftype(type)) {
141 warnx("ELF ABI Brand '%u' is unknown",
142 type);
143 printelftypes();
144 }
145 }
146 else {
147 buffer[EI_OSABI] = type;
148 lseek(fd, 0, SEEK_SET);
149 if (write(fd, buffer, EI_NIDENT) != EI_NIDENT) {
150 warn("error writing %s %d", argv[0], fd);
151 retval = 1;
152 goto fail;
153 }
154 }
155 fail:
156 close(fd);
157 argc--;
158 argv++;
159 }
160
161 return retval;
162 }
163
164 static void
usage(void)165 usage(void)
166 {
167 (void)fprintf(stderr,
168 "usage: brandelf [-lv] [-f ELF_ABI_number] [-t string] file ...\n");
169 exit(1);
170 }
171
172 static const char *
iselftype(int etype)173 iselftype(int etype)
174 {
175 size_t elfwalk;
176
177 for (elfwalk = 0;
178 elfwalk < sizeof(elftypes)/sizeof(elftypes[0]);
179 elfwalk++)
180 if (etype == elftypes[elfwalk].value)
181 return elftypes[elfwalk].str;
182 return 0;
183 }
184
185 static int
elftype(const char * elfstrtype)186 elftype(const char *elfstrtype)
187 {
188 size_t elfwalk;
189
190 for (elfwalk = 0;
191 elfwalk < sizeof(elftypes)/sizeof(elftypes[0]);
192 elfwalk++)
193 if (strcasecmp(elfstrtype, elftypes[elfwalk].str) == 0)
194 return elftypes[elfwalk].value;
195 return -1;
196 }
197
198 static void
printelftypes(void)199 printelftypes(void)
200 {
201 size_t elfwalk;
202
203 fprintf(stderr, "known ELF types are: ");
204 for (elfwalk = 0;
205 elfwalk < sizeof(elftypes)/sizeof(elftypes[0]);
206 elfwalk++)
207 fprintf(stderr, "%s(%u) ", elftypes[elfwalk].str,
208 elftypes[elfwalk].value);
209 fprintf(stderr, "\n");
210 }
211