usr.bin/ldd/ldd.c

   1 /*
   2  * Copyright (c) 1993 Paul Kranenburg
   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  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by Paul Kranenburg.
  16  * 4. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include <sys/cdefs.h>
  32 __FBSDID("$FreeBSD$");
  33
  34 #include <sys/wait.h>
  35
  36 #include <machine/elf.h>
  37
  38 #include <arpa/inet.h>
  39
  40 #include <a.out.h>
  41 #include <dlfcn.h>
  42 #include <err.h>
  43 #include <fcntl.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <unistd.h>
  47
  48 #include "extern.h"
  49
  50 static void
  51 usage(void)
  52 {
  53         fprintf(stderr, "usage: ldd [-a] [-v] [-f format] program ...\n");
  54         exit(1);
  55 }
  56
  57 int
  58 main(int argc, char *argv[])
  59 {
  60         char            *fmt1 = NULL, *fmt2 = NULL;
  61         int             rval;
  62         int             c;
  63         int             aflag, vflag;
  64
  65         aflag = vflag = 0;
  66
  67         while ((c = getopt(argc, argv, "avf:")) != -1) {
  68                 switch (c) {
  69                 case 'a':
  70                         aflag++;
  71                         break;
  72                 case 'v':
  73                         vflag++;
  74                         break;
  75                 case 'f':
  76                         if (fmt1) {
  77                                 if (fmt2)
  78                                         errx(1, "too many formats");
  79                                 fmt2 = optarg;
  80                         } else
  81                                 fmt1 = optarg;
  82                         break;
  83                 default:
  84                         usage();
  85                         /*NOTREACHED*/
  86                 }
  87         }
  88         argc -= optind;
  89         argv += optind;
  90
  91         if (vflag && fmt1)
  92                 errx(1, "-v may not be used with -f");
  93
  94         if (argc <= 0) {
  95                 usage();
  96                 /*NOTREACHED*/
  97         }
  98
  99 #ifdef __i386__
 100         if (vflag) {
 101                 for (c = 0; c < argc; c++)
 102                         dump_file(argv[c]);
 103                 exit(error_count == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
 104         }
 105 #endif
 106
 107         /* ld.so magic */
 108         setenv("LD_TRACE_LOADED_OBJECTS", "yes", 1);
 109         if (fmt1)
 110                 setenv("LD_TRACE_LOADED_OBJECTS_FMT1", fmt1, 1);
 111         if (fmt2)
 112                 setenv("LD_TRACE_LOADED_OBJECTS_FMT2", fmt2, 1);
 113
 114         rval = 0;
 115         for ( ;  argc > 0;  argc--, argv++) {
 116                 int     fd;
 117                 union {
 118                         struct exec aout;
 119                         Elf_Ehdr elf;
 120                 } hdr;
 121                 int     n;
 122                 int     status;
 123                 int     file_ok;
 124                 int     is_shlib;
 125
 126                 if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
 127                         warn("%s", *argv);
 128                         rval |= 1;
 129                         continue;
 130                 }
 131                 if ((n = read(fd, &hdr, sizeof hdr)) == -1) {
 132                         warn("%s: can't read program header", *argv);
 133                         (void)close(fd);
 134                         rval |= 1;
 135                         continue;
 136                 }
 137
 138                 file_ok = 1;
 139                 is_shlib = 0;
 140                 if ((size_t)n >= sizeof hdr.aout && !N_BADMAG(hdr.aout)) {
 141                         /* a.out file */
 142                         if ((N_GETFLAG(hdr.aout) & EX_DPMASK) != EX_DYNAMIC
 143 #if 1 /* Compatibility */
 144                             || hdr.aout.a_entry < __LDPGSZ
 145 #endif
 146                                 ) {
 147                                 warnx("%s: not a dynamic executable", *argv);
 148                                 file_ok = 0;
 149                         }
 150                 } else if ((size_t)n >= sizeof hdr.elf && IS_ELF(hdr.elf)) {
 151                         Elf_Ehdr ehdr;
 152                         Elf_Phdr phdr;
 153                         int dynamic = 0, i;
 154
 155                         if (lseek(fd, 0, SEEK_SET) == -1 ||
 156                             read(fd, &ehdr, sizeof ehdr) != sizeof ehdr ||
 157                             lseek(fd, ehdr.e_phoff, SEEK_SET) == -1
 158                            ) {
 159                                 warnx("%s: can't read program header", *argv);
 160                                 file_ok = 0;
 161                         } else {
 162                                 for (i = 0; i < ehdr.e_phnum; i++) {
 163                                         if (read(fd, &phdr, ehdr.e_phentsize)
 164                                            != sizeof phdr) {
 165                                                 warnx("%s: can't read program header",
 166                                                     *argv);
 167                                                 file_ok = 0;
 168                                                 break;
 169                                         }
 170                                         if (phdr.p_type == PT_DYNAMIC)
 171                                                 dynamic = 1;
 172                                 }
 173                         }
 174                         if (!dynamic) {
 175                                 warnx("%s: not a dynamic executable", *argv);
 176                                 file_ok = 0;
 177                         } else if (hdr.elf.e_type == ET_DYN) {
 178                                 if (hdr.elf.e_ident[EI_OSABI] & ELFOSABI_FREEBSD) {
 179                                         is_shlib = 1;
 180                                 } else {
 181                                         warnx("%s: not a FreeBSD ELF shared "
 182                                               "object", *argv);
 183                                         file_ok = 0;
 184                                 }
 185                         }
 186                 } else {
 187                         warnx("%s: not a dynamic executable", *argv);
 188                         file_ok = 0;
 189                 }
 190                 (void)close(fd);
 191                 if (!file_ok) {
 192                         rval |= 1;
 193                         continue;
 194                 }
 195
 196                 setenv("LD_TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1);
 197                 if (aflag) setenv("LD_TRACE_LOADED_OBJECTS_ALL", "1", 1);
 198                 else if (fmt1 == NULL && fmt2 == NULL)
 199                         /* Default formats */
 200                         printf("%s:\n", *argv);
 201
 202                 fflush(stdout);
 203
 204                 switch (fork()) {
 205                 case -1:
 206                         err(1, "fork");
 207                         break;
 208                 default:
 209                         if (wait(&status) <= 0) {
 210                                 warn("wait");
 211                                 rval |= 1;
 212                         } else if (WIFSIGNALED(status)) {
 213                                 fprintf(stderr, "%s: signal %d\n",
 214                                                 *argv, WTERMSIG(status));
 215                                 rval |= 1;
 216                         } else if (WIFEXITED(status) && WEXITSTATUS(status)) {
 217                                 fprintf(stderr, "%s: exit status %d\n",
 218                                                 *argv, WEXITSTATUS(status));
 219                                 rval |= 1;
 220                         }
 221                         break;
 222                 case 0:
 223                         if (is_shlib == 0) {
 224                                 execl(*argv, *argv, (char *)NULL);
 225                                 warn("%s", *argv);
 226                         } else {
 227                                 dlopen(*argv, RTLD_TRACE);
 228                                 warnx("%s: %s", *argv, dlerror());
 229                         }
 230                         _exit(1);
 231                 }
 232         }
 233
 234         return rval;
 235 }