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  * $FreeBSD: src/usr.bin/ldd/ldd.c,v 1.18.2.7 2002/02/27 18:35:53 sobomax Exp $
  31  */
  32
  33 #include <sys/param.h>
  34 #include <sys/wait.h>
  35
  36 #include <machine/elf.h>
  37 #include <a.out.h>
  38 #include <dlfcn.h>
  39 #include <err.h>
  40 #include <fcntl.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <unistd.h>
  44
  45 static void     usage(void);
  46
  47 static void
  48 usage(void)
  49 {
  50         fprintf(stderr, "usage: ldd [-av] [-f format] program ...\n");
  51         exit(1);
  52 }
  53
  54 int
  55 main(int argc, char **argv)
  56 {
  57         char            *fmt1 = NULL, *fmt2 = NULL;
  58         int             rval;
  59         int             c;
  60         int             aflag;
  61
  62         aflag = 0;
  63         while ((c = getopt(argc, argv, "af:v")) != -1) {
  64                 switch (c) {
  65                 case 'a':
  66                         aflag++;
  67                         break;
  68                 case 'f':
  69                         if (fmt1) {
  70                                 if (fmt2)
  71                                         errx(1, "too many formats");
  72                                 fmt2 = optarg;
  73                         } else
  74                                 fmt1 = optarg;
  75                         break;
  76                 case 'v':
  77                         break;
  78                 default:
  79                         usage();
  80                         /* NOTREACHED */
  81                 }
  82         }
  83         argc -= optind;
  84         argv += optind;
  85
  86         if (argc <= 0) {
  87                 usage();
  88                 /* NOTREACHED */
  89         }
  90
  91         /* ld.so magic */
  92         if (setenv("LD_TRACE_LOADED_OBJECTS", "yes", 1) == -1)
  93                 err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS=1");
  94         if (fmt1) {
  95                 if (setenv("LD_TRACE_LOADED_OBJECTS_FMT1", fmt1, 1) == -1)
  96                         err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS_FMT1=%s", fmt1);
  97         }
  98         if (fmt2) {
  99                 if (setenv("LD_TRACE_LOADED_OBJECTS_FMT2", fmt2, 1) == -1)
 100                         err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS_FMT2=%s", fmt2);
 101         }
 102
 103         rval = 0;
 104         for ( ;  argc > 0;  argc--, argv++) {
 105                 int     fd;
 106                 union {
 107                         Elf_Ehdr elf;
 108                 } hdr;
 109                 ssize_t n;
 110                 int     status;
 111                 int     file_ok;
 112                 int     is_shlib;
 113
 114                 if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
 115                         warn("%s", *argv);
 116                         rval |= 1;
 117                         continue;
 118                 }
 119                 if ((n = read(fd, &hdr, sizeof hdr)) == -1) {
 120                         warn("%s: can't read program header", *argv);
 121                         close(fd);
 122                         rval |= 1;
 123                         continue;
 124                 }
 125
 126                 file_ok = 1;
 127                 is_shlib = 0;
 128                 if ((size_t)n >= sizeof hdr.elf && IS_ELF(hdr.elf)) {
 129                         Elf_Ehdr ehdr;
 130                         Elf_Phdr phdr;
 131                         int dynamic = 0, i;
 132
 133                         if (lseek(fd, 0, SEEK_SET) == -1 ||
 134                             read(fd, &ehdr, sizeof ehdr) != sizeof ehdr ||
 135                             lseek(fd, ehdr.e_phoff, SEEK_SET) == -1
 136                            ) {
 137                                 warnx("%s: can't read program header", *argv);
 138                                 file_ok = 0;
 139                         } else {
 140                                 for (i = 0; i < ehdr.e_phnum; i++) {
 141                                         if (read(fd, &phdr, ehdr.e_phentsize)
 142                                            != sizeof phdr) {
 143                                                 warnx("%s: can't read program header",
 144                                                     *argv);
 145                                                 file_ok = 0;
 146                                                 break;
 147                                         }
 148                                         if (phdr.p_type == PT_DYNAMIC)
 149                                                 dynamic = 1;
 150                                 }
 151                         }
 152                         if (!dynamic) {
 153                                 warnx("%s: not a dynamic executable", *argv);
 154                                 file_ok = 0;
 155                         } else if (hdr.elf.e_type == ET_DYN) {
 156                                 is_shlib = 1;
 157                         }
 158                 } else {
 159                         warnx("%s: not a dynamic executable", *argv);
 160                         file_ok = 0;
 161                 }
 162                 close(fd);
 163                 if (!file_ok) {
 164                         rval |= 1;
 165                         continue;
 166                 }
 167
 168                 if (setenv("LD_TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1) == -1)
 169                         err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS_PROGNAME=%s", *argv);
 170                 if (aflag) setenv("LD_TRACE_LOADED_OBJECTS_ALL", "1", 1);
 171                 else if (fmt1 == NULL && fmt2 == NULL)
 172                         /* Default formats */
 173                         printf("%s:\n", *argv);
 174                 fflush(stdout);
 175
 176                 switch (fork()) {
 177                 case -1:
 178                         err(1, "fork");
 179                         break;
 180                 default:
 181                         if (wait(&status) <= 0) {
 182                                 warn("wait");
 183                                 rval |= 1;
 184                         } else if (WIFSIGNALED(status)) {
 185                                 fprintf(stderr, "%s: signal %d\n",
 186                                                 *argv, WTERMSIG(status));
 187                                 rval |= 1;
 188                         } else if (WIFEXITED(status) && WEXITSTATUS(status)) {
 189                                 fprintf(stderr, "%s: exit status %d\n",
 190                                                 *argv, WEXITSTATUS(status));
 191                                 rval |= 1;
 192                         }
 193                         break;
 194                 case 0:
 195                         if (is_shlib == 0) {
 196                                 execl(*argv, *argv, NULL);
 197                                 warn("%s", *argv);
 198                         } else {
 199                                 dlopen(*argv, RTLD_TRACE);
 200                                 warnx("%s: %s", *argv, dlerror());
 201                         }
 202                         _exit(1);
 203                 }
 204         }
 205
 206         return rval;
 207 }