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  * $DragonFly: src/usr.bin/ldd/ldd.c,v 1.2 2003/06/17 04:29:27 dillon Exp $
  32  */
  33
  34 #include <sys/wait.h>
  35 #include <machine/elf.h>
  36 #include <a.out.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 extern void     dump_file __P((const char *));
  45 extern int      error_count;
  46
  47 void
  48 usage()
  49 {
  50         fprintf(stderr, "usage: ldd [-v] [-f format] program ...\n");
  51         exit(1);
  52 }
  53
  54 int
  55 main(argc, argv)
  56 int     argc;
  57 char    *argv[];
  58 {
  59         char            *fmt1 = NULL, *fmt2 = NULL;
  60         int             rval;
  61         int             c;
  62         int             vflag = 0;
  63
  64         while ((c = getopt(argc, argv, "vf:")) != -1) {
  65                 switch (c) {
  66                 case 'v':
  67                         vflag++;
  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                 default:
  78                         usage();
  79                         /*NOTREACHED*/
  80                 }
  81         }
  82         argc -= optind;
  83         argv += optind;
  84
  85         if (vflag && fmt1)
  86                 errx(1, "-v may not be used with -f");
  87
  88         if (argc <= 0) {
  89                 usage();
  90                 /*NOTREACHED*/
  91         }
  92
  93 #ifdef __i386__
  94         if (vflag) {
  95                 for (c = 0; c < argc; c++)
  96                         dump_file(argv[c]);
  97                 exit(error_count == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
  98         }
  99 #endif
 100
 101         /* ld.so magic */
 102         setenv("LD_TRACE_LOADED_OBJECTS", "1", 1);
 103         if (fmt1)
 104                 setenv("LD_TRACE_LOADED_OBJECTS_FMT1", fmt1, 1);
 105         if (fmt2)
 106                 setenv("LD_TRACE_LOADED_OBJECTS_FMT2", fmt2, 1);
 107
 108         rval = 0;
 109         for ( ;  argc > 0;  argc--, argv++) {
 110                 int     fd;
 111                 union {
 112                         struct exec aout;
 113                         Elf_Ehdr elf;
 114                 } hdr;
 115                 int     n;
 116                 int     status;
 117                 int     file_ok;
 118                 int     is_shlib;
 119
 120                 if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
 121                         warn("%s", *argv);
 122                         rval |= 1;
 123                         continue;
 124                 }
 125                 if ((n = read(fd, &hdr, sizeof hdr)) == -1) {
 126                         warn("%s: can't read program header", *argv);
 127                         (void)close(fd);
 128                         rval |= 1;
 129                         continue;
 130                 }
 131
 132                 file_ok = 1;
 133                 is_shlib = 0;
 134                 if (n >= sizeof hdr.aout && !N_BADMAG(hdr.aout)) {
 135                         /* a.out file */
 136                         if ((N_GETFLAG(hdr.aout) & EX_DPMASK) != EX_DYNAMIC
 137 #if 1 /* Compatibility */
 138                             || hdr.aout.a_entry < __LDPGSZ
 139 #endif
 140                                 ) {
 141                                 warnx("%s: not a dynamic executable", *argv);
 142                                 file_ok = 0;
 143                         }
 144                 } else if (n >= sizeof hdr.elf && IS_ELF(hdr.elf)) {
 145                         Elf_Ehdr ehdr;
 146                         Elf_Phdr phdr;
 147                         int dynamic = 0, i;
 148
 149                         if (lseek(fd, 0, SEEK_SET) == -1 ||
 150                             read(fd, &ehdr, sizeof ehdr) != sizeof ehdr ||
 151                             lseek(fd, ehdr.e_phoff, SEEK_SET) == -1
 152                            ) {
 153                                 warnx("%s: can't read program header", *argv);
 154                                 file_ok = 0;
 155                         } else {
 156                                 for (i = 0; i < ehdr.e_phnum; i++) {
 157                                         if (read(fd, &phdr, ehdr.e_phentsize)
 158                                            != sizeof phdr) {
 159                                                 warnx("%s: can't read program header",
 160                                                     *argv);
 161                                                 file_ok = 0;
 162                                                 break;
 163                                         }
 164                                         if (phdr.p_type == PT_DYNAMIC)
 165                                                 dynamic = 1;
 166                                 }
 167                         }
 168                         if (!dynamic) {
 169                                 warnx("%s: not a dynamic executable", *argv);
 170                                 file_ok = 0;
 171                         } else if (hdr.elf.e_type == ET_DYN) {
 172                                 if (hdr.elf.e_ident[EI_OSABI] & ELFOSABI_FREEBSD) {
 173                                         is_shlib = 1;
 174                                 } else {
 175                                         warnx("%s: not a FreeBSD ELF shared "
 176                                               "object", *argv);
 177                                         file_ok = 0;
 178                                 }
 179                         }
 180                 } else {
 181                         warnx("%s: not a dynamic executable", *argv);
 182                         file_ok = 0;
 183                 }
 184                 (void)close(fd);
 185                 if (!file_ok) {
 186                         rval |= 1;
 187                         continue;
 188                 }
 189
 190                 setenv("LD_TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1);
 191                 if (fmt1 == NULL && fmt2 == NULL)
 192                         /* Default formats */
 193                         printf("%s:\n", *argv);
 194
 195                 fflush(stdout);
 196
 197                 switch (fork()) {
 198                 case -1:
 199                         err(1, "fork");
 200                         break;
 201                 default:
 202                         if (wait(&status) <= 0) {
 203                                 warn("wait");
 204                                 rval |= 1;
 205                         } else if (WIFSIGNALED(status)) {
 206                                 fprintf(stderr, "%s: signal %d\n",
 207                                                 *argv, WTERMSIG(status));
 208                                 rval |= 1;
 209                         } else if (WIFEXITED(status) && WEXITSTATUS(status)) {
 210                                 fprintf(stderr, "%s: exit status %d\n",
 211                                                 *argv, WEXITSTATUS(status));
 212                                 rval |= 1;
 213                         }
 214                         break;
 215                 case 0:
 216                         if (is_shlib == 0) {
 217                                 execl(*argv, *argv, (char *)NULL);
 218                                 warn("%s", *argv);
 219                         } else {
 220                                 dlopen(*argv, RTLD_TRACE);
 221                                 warnx("%s: %s", *argv, dlerror());
 222                         }
 223                         _exit(1);
 224                 }
 225         }
 226
 227         return rval;
 228 }