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 1.6 2006/01/12 13:43:11 corecode Exp $
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/wait.h>
  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 [-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             vflag = 0;
  62
  63         while ((c = getopt(argc, argv, "vf:")) != -1) {
  64                 switch (c) {
  65                 case 'v':
  66                         vflag++;
  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                 default:
  77                         usage();
  78                         /*NOTREACHED*/
  79                 }
  80         }
  81         argc -= optind;
  82         argv += optind;
  83
  84         if (vflag && fmt1)
  85                 errx(1, "-v may not be used with -f");
  86
  87         if (argc <= 0) {
  88                 usage();
  89                 /*NOTREACHED*/
  90         }
  91
  92 #ifdef __i386__
  93         if (vflag) {
  94                 for (c = 0; c < argc; c++)
  95                         dump_file(argv[c]);
  96                 exit(error_count == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
  97         }
  98 #endif
  99
 100         /* ld.so magic */
 101         if (setenv("LD_TRACE_LOADED_OBJECTS", "1", 1) == -1)
 102                 err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS=1");
 103         if (fmt1) {
 104                 if (setenv("LD_TRACE_LOADED_OBJECTS_FMT1", fmt1, 1) == -1)
 105                         err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS_FMT1=%s", fmt1);
 106         }
 107         if (fmt2) {
 108                 if (setenv("LD_TRACE_LOADED_OBJECTS_FMT2", fmt2, 1) == -1)
 109                         err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS_FMT2=%s", fmt2);
 110         }
 111
 112         rval = 0;
 113         for ( ;  argc > 0;  argc--, argv++) {
 114                 int     fd;
 115                 union {
 116                         struct exec aout;
 117                         Elf_Ehdr elf;
 118                 } hdr;
 119                 int     n;
 120                 int     status;
 121                 int     file_ok;
 122                 int     is_shlib;
 123
 124                 if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
 125                         warn("%s", *argv);
 126                         rval |= 1;
 127                         continue;
 128                 }
 129                 if ((n = read(fd, &hdr, sizeof hdr)) == -1) {
 130                         warn("%s: can't read program header", *argv);
 131                         (void)close(fd);
 132                         rval |= 1;
 133                         continue;
 134                 }
 135
 136                 file_ok = 1;
 137                 is_shlib = 0;
 138                 if (n >= sizeof hdr.aout && !N_BADMAG(hdr.aout)) {
 139                         /* a.out file */
 140                         if ((N_GETFLAG(hdr.aout) & EX_DPMASK) != EX_DYNAMIC
 141 #if 1 /* Compatibility */
 142                             || hdr.aout.a_entry < __LDPGSZ
 143 #endif
 144                                 ) {
 145                                 warnx("%s: not a dynamic executable", *argv);
 146                                 file_ok = 0;
 147                         }
 148                 } else if (n >= sizeof hdr.elf && IS_ELF(hdr.elf)) {
 149                         Elf_Ehdr ehdr;
 150                         Elf_Phdr phdr;
 151                         int dynamic = 0, i;
 152
 153                         if (lseek(fd, 0, SEEK_SET) == -1 ||
 154                             read(fd, &ehdr, sizeof ehdr) != sizeof ehdr ||
 155                             lseek(fd, ehdr.e_phoff, SEEK_SET) == -1
 156                            ) {
 157                                 warnx("%s: can't read program header", *argv);
 158                                 file_ok = 0;
 159                         } else {
 160                                 for (i = 0; i < ehdr.e_phnum; i++) {
 161                                         if (read(fd, &phdr, ehdr.e_phentsize)
 162                                            != sizeof phdr) {
 163                                                 warnx("%s: can't read program header",
 164                                                     *argv);
 165                                                 file_ok = 0;
 166                                                 break;
 167                                         }
 168                                         if (phdr.p_type == PT_DYNAMIC)
 169                                                 dynamic = 1;
 170                                 }
 171                         }
 172                         if (!dynamic) {
 173                                 warnx("%s: not a dynamic executable", *argv);
 174                                 file_ok = 0;
 175                         } else if (hdr.elf.e_type == ET_DYN) {
 176                                 is_shlib = 1;
 177                         }
 178                 } else {
 179                         warnx("%s: not a dynamic executable", *argv);
 180                         file_ok = 0;
 181                 }
 182                 (void)close(fd);
 183                 if (!file_ok) {
 184                         rval |= 1;
 185                         continue;
 186                 }
 187
 188                 if (setenv("LD_TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1) == -1)
 189                         err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS_PROGNAME=%s", *argv);
 190                 if (fmt1 == NULL && fmt2 == NULL)
 191                         /* Default formats */
 192                         printf("%s:\n", *argv);
 193
 194                 fflush(stdout);
 195
 196                 switch (fork()) {
 197                 case -1:
 198                         err(1, "fork");
 199                         break;
 200                 default:
 201                         if (wait(&status) <= 0) {
 202                                 warn("wait");
 203                                 rval |= 1;
 204                         } else if (WIFSIGNALED(status)) {
 205                                 fprintf(stderr, "%s: signal %d\n",
 206                                                 *argv, WTERMSIG(status));
 207                                 rval |= 1;
 208                         } else if (WIFEXITED(status) && WEXITSTATUS(status)) {
 209                                 fprintf(stderr, "%s: exit status %d\n",
 210                                                 *argv, WEXITSTATUS(status));
 211                                 rval |= 1;
 212                         }
 213                         break;
 214                 case 0:
 215                         if (is_shlib == 0) {
 216                                 execl(*argv, *argv, (char *)NULL);
 217                                 warn("%s", *argv);
 218                         } else {
 219                                 dlopen(*argv, RTLD_TRACE);
 220                                 warnx("%s: %s", *argv, dlerror());
 221                         }
 222                         _exit(1);
 223                 }
 224         }
 225
 226         return rval;
 227 }