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 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/wait.h> 35 36 #include <machine/elf.h> 37 38 #include <arpa/inet.h> 39 40 #include <a.out.h> 41 #include <dlfcn.h> 42 #include <err.h> 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <string.h> 48 #include <unistd.h> 49 50 #include "extern.h" 51 52 #ifdef COMPAT_32BIT 53 #define LD_ "LD_32_" 54 #else 55 #define LD_ "LD_" 56 #endif 57 58 /* 59 * 32-bit ELF data structures can only be used if the system header[s] declare 60 * them. There is no official macro for determining whether they are declared, 61 * so check for the existence of one of the 32-macros defined in elf(5). 62 */ 63 #ifdef ELF32_R_TYPE 64 #define ELF32_SUPPORTED 65 #endif 66 67 static int is_executable(const char *fname, int fd, int *is_shlib, 68 int *type); 69 static void usage(void); 70 71 #define TYPE_UNKNOWN 0 72 #define TYPE_AOUT 1 73 #define TYPE_ELF 2 /* Architecture default */ 74 #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) 75 #define TYPE_ELF32 3 /* Explicit 32 bits on architectures >32 bits */ 76 77 #define _PATH_LDD32 "/usr/bin/ldd32" 78 79 static int 80 execldd32(char *file, char *fmt1, char *fmt2, int aflag, int vflag) 81 { 82 char *argv[8]; 83 int i, rval, status; 84 85 unsetenv(LD_ "TRACE_LOADED_OBJECTS"); 86 rval = 0; 87 i = 0; 88 argv[i++] = strdup(_PATH_LDD32); 89 if (aflag) 90 argv[i++] = strdup("-a"); 91 if (vflag) 92 argv[i++] = strdup("-v"); 93 if (fmt1 != NULL) { 94 argv[i++] = strdup("-f"); 95 argv[i++] = strdup(fmt1); 96 } 97 if (fmt2 != NULL) { 98 argv[i++] = strdup("-f"); 99 argv[i++] = strdup(fmt2); 100 } 101 argv[i++] = strdup(file); 102 argv[i++] = NULL; 103 104 switch (fork()) { 105 case -1: 106 err(1, "fork"); 107 break; 108 case 0: 109 execv(_PATH_LDD32, argv); 110 warn("%s", _PATH_LDD32); 111 _exit(127); 112 break; 113 default: 114 if (wait(&status) < 0) 115 rval = 1; 116 else if (WIFSIGNALED(status)) 117 rval = 1; 118 else if (WIFEXITED(status) && WEXITSTATUS(status) != 0) 119 rval = 1; 120 break; 121 } 122 while (i--) 123 free(argv[i]); 124 setenv(LD_ "TRACE_LOADED_OBJECTS", "yes", 1); 125 return (rval); 126 } 127 #endif 128 129 int 130 main(int argc, char *argv[]) 131 { 132 char *fmt1, *fmt2; 133 int rval, c, aflag, vflag; 134 135 aflag = vflag = 0; 136 fmt1 = fmt2 = NULL; 137 138 while ((c = getopt(argc, argv, "af:v")) != -1) { 139 switch (c) { 140 case 'a': 141 aflag++; 142 break; 143 case 'f': 144 if (fmt1 != NULL) { 145 if (fmt2 != NULL) 146 errx(1, "too many formats"); 147 fmt2 = optarg; 148 } else 149 fmt1 = optarg; 150 break; 151 case 'v': 152 vflag++; 153 break; 154 default: 155 usage(); 156 /* NOTREACHED */ 157 } 158 } 159 argc -= optind; 160 argv += optind; 161 162 if (vflag && fmt1 != NULL) 163 errx(1, "-v may not be used with -f"); 164 165 if (argc <= 0) { 166 usage(); 167 /* NOTREACHED */ 168 } 169 170 #ifdef __i386__ 171 if (vflag) { 172 for (c = 0; c < argc; c++) 173 dump_file(argv[c]); 174 exit(error_count == 0 ? EXIT_SUCCESS : EXIT_FAILURE); 175 } 176 #endif 177 178 rval = 0; 179 for (; argc > 0; argc--, argv++) { 180 int fd, status, is_shlib, rv, type; 181 182 if ((fd = open(*argv, O_RDONLY, 0)) < 0) { 183 warn("%s", *argv); 184 rval |= 1; 185 continue; 186 } 187 rv = is_executable(*argv, fd, &is_shlib, &type); 188 close(fd); 189 if (rv == 0) { 190 rval |= 1; 191 continue; 192 } 193 194 switch (type) { 195 case TYPE_ELF: 196 case TYPE_AOUT: 197 break; 198 #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) 199 case TYPE_ELF32: 200 rval |= execldd32(*argv, fmt1, fmt2, aflag, vflag); 201 continue; 202 #endif 203 case TYPE_UNKNOWN: 204 default: 205 /* 206 * This shouldn't happen unless is_executable() 207 * is broken. 208 */ 209 errx(EDOOFUS, "unknown executable type"); 210 } 211 212 /* ld.so magic */ 213 setenv(LD_ "TRACE_LOADED_OBJECTS", "yes", 1); 214 if (fmt1 != NULL) 215 setenv(LD_ "TRACE_LOADED_OBJECTS_FMT1", fmt1, 1); 216 if (fmt2 != NULL) 217 setenv(LD_ "TRACE_LOADED_OBJECTS_FMT2", fmt2, 1); 218 219 setenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1); 220 if (aflag) 221 setenv(LD_ "TRACE_LOADED_OBJECTS_ALL", "1", 1); 222 else if (fmt1 == NULL && fmt2 == NULL) 223 /* Default formats */ 224 printf("%s:\n", *argv); 225 fflush(stdout); 226 227 switch (fork()) { 228 case -1: 229 err(1, "fork"); 230 break; 231 default: 232 if (wait(&status) < 0) { 233 warn("wait"); 234 rval |= 1; 235 } else if (WIFSIGNALED(status)) { 236 fprintf(stderr, "%s: signal %d\n", *argv, 237 WTERMSIG(status)); 238 rval |= 1; 239 } else if (WIFEXITED(status) && 240 WEXITSTATUS(status) != 0) { 241 fprintf(stderr, "%s: exit status %d\n", *argv, 242 WEXITSTATUS(status)); 243 rval |= 1; 244 } 245 break; 246 case 0: 247 if (is_shlib == 0) { 248 execl(*argv, *argv, (char *)NULL); 249 warn("%s", *argv); 250 } else { 251 dlopen(*argv, RTLD_TRACE); 252 warnx("%s: %s", *argv, dlerror()); 253 } 254 _exit(1); 255 } 256 } 257 258 return rval; 259 } 260 261 static void 262 usage(void) 263 { 264 265 fprintf(stderr, "usage: ldd [-a] [-v] [-f format] program ...\n"); 266 exit(1); 267 } 268 269 static int 270 is_executable(const char *fname, int fd, int *is_shlib, int *type) 271 { 272 union { 273 struct exec aout; 274 #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) 275 Elf32_Ehdr elf32; 276 #endif 277 Elf_Ehdr elf; 278 } hdr; 279 int n; 280 281 *is_shlib = 0; 282 *type = TYPE_UNKNOWN; 283 284 if ((n = read(fd, &hdr, sizeof(hdr))) == -1) { 285 warn("%s: can't read program header", fname); 286 return (0); 287 } 288 289 if ((size_t)n >= sizeof(hdr.aout) && !N_BADMAG(hdr.aout)) { 290 /* a.out file */ 291 if ((N_GETFLAG(hdr.aout) & EX_DPMASK) != EX_DYNAMIC 292 #if 1 /* Compatibility */ 293 || hdr.aout.a_entry < __LDPGSZ 294 #endif 295 ) { 296 warnx("%s: not a dynamic executable", fname); 297 return (0); 298 } 299 *type = TYPE_AOUT; 300 return (1); 301 } 302 303 #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) 304 if ((size_t)n >= sizeof(hdr.elf32) && IS_ELF(hdr.elf32) && 305 hdr.elf32.e_ident[EI_CLASS] == ELFCLASS32) { 306 /* Handle 32 bit ELF objects */ 307 Elf32_Phdr phdr; 308 int dynamic, i; 309 310 dynamic = 0; 311 *type = TYPE_ELF32; 312 313 if (lseek(fd, hdr.elf32.e_phoff, SEEK_SET) == -1) { 314 warnx("%s: header too short", fname); 315 return (0); 316 } 317 for (i = 0; i < hdr.elf32.e_phnum; i++) { 318 if (read(fd, &phdr, hdr.elf32.e_phentsize) != 319 sizeof(phdr)) { 320 warnx("%s: can't read program header", fname); 321 return (0); 322 } 323 if (phdr.p_type == PT_DYNAMIC) { 324 dynamic = 1; 325 break; 326 } 327 } 328 329 if (!dynamic) { 330 warnx("%s: not a dynamic ELF executable", fname); 331 return (0); 332 } 333 if (hdr.elf32.e_type == ET_DYN) { 334 if (hdr.elf32.e_ident[EI_OSABI] == ELFOSABI_FREEBSD) { 335 *is_shlib = 1; 336 return (1); 337 } 338 warnx("%s: not a FreeBSD ELF shared object", fname); 339 return (0); 340 } 341 342 return (1); 343 } 344 #endif 345 346 if ((size_t)n >= sizeof(hdr.elf) && IS_ELF(hdr.elf) && 347 hdr.elf.e_ident[EI_CLASS] == ELF_TARG_CLASS) { 348 /* Handle default ELF objects on this architecture */ 349 Elf_Phdr phdr; 350 int dynamic, i; 351 352 dynamic = 0; 353 *type = TYPE_ELF; 354 355 if (lseek(fd, hdr.elf.e_phoff, SEEK_SET) == -1) { 356 warnx("%s: header too short", fname); 357 return (0); 358 } 359 for (i = 0; i < hdr.elf.e_phnum; i++) { 360 if (read(fd, &phdr, hdr.elf.e_phentsize) 361 != sizeof(phdr)) { 362 warnx("%s: can't read program header", fname); 363 return (0); 364 } 365 if (phdr.p_type == PT_DYNAMIC) { 366 dynamic = 1; 367 break; 368 } 369 } 370 371 if (!dynamic) { 372 warnx("%s: not a dynamic ELF executable", fname); 373 return (0); 374 } 375 if (hdr.elf.e_type == ET_DYN) { 376 if (hdr.elf.e_ident[EI_OSABI] == ELFOSABI_FREEBSD) { 377 *is_shlib = 1; 378 return (1); 379 } 380 warnx("%s: not a FreeBSD ELF shared object", fname); 381 return (0); 382 } 383 384 return (1); 385 } 386 387 warnx("%s: not a dynamic executable", fname); 388 return (0); 389 } 390