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 extern void     dump_file(const char *);
  46 extern int      error_count;
  47
  48 void
  49 usage(void)
  50 {
  51         fprintf(stderr, "usage: ldd [-a] [-v] [-f format] program ...\n");
  52         exit(1);
  53 }
  54
  55 int
  56 main(int argc, char **argv)
  57 {
  58         char            *fmt1 = NULL, *fmt2 = NULL;
  59         int             rval;
  60         int             c;
  61         int             aflag, vflag;
  62
  63         aflag = vflag = 0;
  64         while ((c = getopt(argc, argv, "avf:")) != -1) {
  65                 switch (c) {
  66                 case 'a':
  67                         aflag++;
  68                         break;
  69                 case 'f':
  70                         if (fmt1) {
  71                                 if (fmt2)
  72                                         errx(1, "too many formats");
  73                                 fmt2 = optarg;
  74                         } else
  75                                 fmt1 = optarg;
  76                         break;
  77                 case 'v':
  78                         vflag++;
  79                         break;
  80                 default:
  81                         usage();
  82                         /* NOTREACHED */
  83                 }
  84         }
  85         argc -= optind;
  86         argv += optind;
  87
  88         if (vflag && fmt1)
  89                 errx(1, "-v may not be used with -f");
  90
  91         if (argc <= 0) {
  92                 usage();
  93                 /* NOTREACHED */
  94         }
  95
  96 #ifdef __i386__
  97         if (vflag) {
  98                 for (c = 0; c < argc; c++)
  99                         dump_file(argv[c]);
 100                 exit(error_count == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
 101         }
 102 #endif
 103
 104         /* ld.so magic */
 105         if (setenv("LD_TRACE_LOADED_OBJECTS", "yes", 1) == -1)
 106                 err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS=1");
 107         if (fmt1) {
 108                 if (setenv("LD_TRACE_LOADED_OBJECTS_FMT1", fmt1, 1) == -1)
 109                         err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS_FMT1=%s", fmt1);
 110         }
 111         if (fmt2) {
 112                 if (setenv("LD_TRACE_LOADED_OBJECTS_FMT2", fmt2, 1) == -1)
 113                         err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS_FMT2=%s", fmt2);
 114         }
 115
 116         rval = 0;
 117         for ( ;  argc > 0;  argc--, argv++) {
 118                 int     fd;
 119                 union {
 120                         struct exec aout;
 121                         Elf_Ehdr elf;
 122                 } hdr;
 123                 int     n;
 124                 int     status;
 125                 int     file_ok;
 126                 int     is_shlib;
 127
 128                 if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
 129                         warn("%s", *argv);
 130                         rval |= 1;
 131                         continue;
 132                 }
 133                 if ((n = read(fd, &hdr, sizeof hdr)) == -1) {
 134                         warn("%s: can't read program header", *argv);
 135                         (void)close(fd);
 136                         rval |= 1;
 137                         continue;
 138                 }
 139
 140                 file_ok = 1;
 141                 is_shlib = 0;
 142                 if (n >= sizeof hdr.aout && !N_BADMAG(hdr.aout)) {
 143                         /* a.out file */
 144                         if ((N_GETFLAG(hdr.aout) & EX_DPMASK) != EX_DYNAMIC
 145 #if 1 /* Compatibility */
 146                             || hdr.aout.a_entry < __LDPGSZ
 147 #endif
 148                                 ) {
 149                                 warnx("%s: not a dynamic executable", *argv);
 150                                 file_ok = 0;
 151                         }
 152                 } else if (n >= sizeof hdr.elf && IS_ELF(hdr.elf)) {
 153                         Elf_Ehdr ehdr;
 154                         Elf_Phdr phdr;
 155                         int dynamic = 0, i;
 156
 157                         if (lseek(fd, 0, SEEK_SET) == -1 ||
 158                             read(fd, &ehdr, sizeof ehdr) != sizeof ehdr ||
 159                             lseek(fd, ehdr.e_phoff, SEEK_SET) == -1
 160                            ) {
 161                                 warnx("%s: can't read program header", *argv);
 162                                 file_ok = 0;
 163                         } else {
 164                                 for (i = 0; i < ehdr.e_phnum; i++) {
 165                                         if (read(fd, &phdr, ehdr.e_phentsize)
 166                                            != sizeof phdr) {
 167                                                 warnx("%s: can't read program header",
 168                                                     *argv);
 169                                                 file_ok = 0;
 170                                                 break;
 171                                         }
 172                                         if (phdr.p_type == PT_DYNAMIC)
 173                                                 dynamic = 1;
 174                                 }
 175                         }
 176                         if (!dynamic) {
 177                                 warnx("%s: not a dynamic executable", *argv);
 178                                 file_ok = 0;
 179                         } else if (hdr.elf.e_type == ET_DYN) {
 180                                 is_shlib = 1;
 181                         }
 182                 } else {
 183                         warnx("%s: not a dynamic executable", *argv);
 184                         file_ok = 0;
 185                 }
 186                 (void)close(fd);
 187                 if (!file_ok) {
 188                         rval |= 1;
 189                         continue;
 190                 }
 191
 192                 if (setenv("LD_TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1) == -1)
 193                         err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS_PROGNAME=%s", *argv);
 194                 if (aflag) setenv("LD_TRACE_LOADED_OBJECTS_ALL", "1", 1);
 195                 else if (fmt1 == NULL && fmt2 == NULL)
 196                         /* Default formats */
 197                         printf("%s:\n", *argv);
 198                 fflush(stdout);
 199
 200                 switch (fork()) {
 201                 case -1:
 202                         err(1, "fork");
 203                         break;
 204                 default:
 205                         if (wait(&status) <= 0) {
 206                                 warn("wait");
 207                                 rval |= 1;
 208                         } else if (WIFSIGNALED(status)) {
 209                                 fprintf(stderr, "%s: signal %d\n",
 210                                                 *argv, WTERMSIG(status));
 211                                 rval |= 1;
 212                         } else if (WIFEXITED(status) && WEXITSTATUS(status)) {
 213                                 fprintf(stderr, "%s: exit status %d\n",
 214                                                 *argv, WEXITSTATUS(status));
 215                                 rval |= 1;
 216                         }
 217                         break;
 218                 case 0:
 219                         if (is_shlib == 0) {
 220                                 execl(*argv, *argv, NULL);
 221                                 warn("%s", *argv);
 222                         } else {
 223                                 dlopen(*argv, RTLD_TRACE);
 224                                 warnx("%s: %s", *argv, dlerror());
 225                         }
 226                         _exit(1);
 227                 }
 228         }
 229
 230         return rval;
 231 }