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