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