usr.bin/brandelf/brandelf.c

   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  * $FreeBSD: src/usr.bin/brandelf/brandelf.c,v 1.25 2005/05/21 09:55:04 ru Exp $
  30  * $DragonFly: src/usr.bin/brandelf/brandelf.c,v 1.4 2007/09/22 20:40:06 pavalos Exp $
  31  */
  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
  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, verbose = 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                         verbose = 1;
  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
 165 usage(void)
 166 {
 167         fprintf(stderr,
 168             "usage: brandelf [-lv] [-f ELF_ABI_number] [-t string] file ...\n");
 169         exit(1);
 170 }
 171
 172 static const char *
 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
 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
 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 }