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 <dlfcn.h> 41 #include <err.h> 42 #include <errno.h> 43 #include <fcntl.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <unistd.h> 48 49 #include "extern.h" 50 51 /* We don't support a.out executables on arm64 */ 52 #ifndef __aarch64__ 53 #include <a.out.h> 54 #define AOUT_SUPPORTED 55 #endif 56 57 /* 58 * 32-bit ELF data structures can only be used if the system header[s] declare 59 * them. There is no official macro for determining whether they are declared, 60 * so check for the existence of one of the 32-macros defined in elf(5). 61 */ 62 #ifdef ELF32_R_TYPE 63 #define ELF32_SUPPORTED 64 #endif 65 66 #define LDD_SETENV(name, value, overwrite) do { \ 67 setenv("LD_" name, value, overwrite); \ 68 setenv("LD_32_" name, value, overwrite); \ 69 } while (0) 70 71 #define LDD_UNSETENV(name) do { \ 72 unsetenv("LD_" name); \ 73 unsetenv("LD_32_" name); \ 74 } while (0) 75 76 static int is_executable(const char *fname, int fd, int *is_shlib, 77 int *type); 78 static void usage(void); 79 80 #define TYPE_UNKNOWN 0 81 #define TYPE_AOUT 1 82 #define TYPE_ELF 2 /* Architecture default */ 83 #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) 84 #define TYPE_ELF32 3 /* Explicit 32 bits on architectures >32 bits */ 85 86 #define _PATH_LDD32 "/usr/bin/ldd32" 87 88 static int 89 execldd32(char *file, char *fmt1, char *fmt2, int aflag, int vflag) 90 { 91 char *argv[8]; 92 int i, rval, status; 93 94 LDD_UNSETENV("TRACE_LOADED_OBJECTS"); 95 rval = 0; 96 i = 0; 97 argv[i++] = strdup(_PATH_LDD32); 98 if (aflag) 99 argv[i++] = strdup("-a"); 100 if (vflag) 101 argv[i++] = strdup("-v"); 102 if (fmt1 != NULL) { 103 argv[i++] = strdup("-f"); 104 argv[i++] = strdup(fmt1); 105 } 106 if (fmt2 != NULL) { 107 argv[i++] = strdup("-f"); 108 argv[i++] = strdup(fmt2); 109 } 110 argv[i++] = strdup(file); 111 argv[i++] = NULL; 112 113 switch (fork()) { 114 case -1: 115 err(1, "fork"); 116 break; 117 case 0: 118 execv(_PATH_LDD32, argv); 119 warn("%s", _PATH_LDD32); 120 _exit(127); 121 break; 122 default: 123 if (wait(&status) < 0) 124 rval = 1; 125 else if (WIFSIGNALED(status)) 126 rval = 1; 127 else if (WIFEXITED(status) && WEXITSTATUS(status) != 0) 128 rval = 1; 129 break; 130 } 131 while (i--) 132 free(argv[i]); 133 LDD_SETENV("TRACE_LOADED_OBJECTS", "yes", 1); 134 return (rval); 135 } 136 #endif 137 138 int 139 main(int argc, char *argv[]) 140 { 141 char *fmt1, *fmt2; 142 int rval, c, aflag, vflag; 143 144 aflag = vflag = 0; 145 fmt1 = fmt2 = NULL; 146 147 while ((c = getopt(argc, argv, "af:v")) != -1) { 148 switch (c) { 149 case 'a': 150 aflag++; 151 break; 152 case 'f': 153 if (fmt1 != NULL) { 154 if (fmt2 != NULL) 155 errx(1, "too many formats"); 156 fmt2 = optarg; 157 } else 158 fmt1 = optarg; 159 break; 160 case 'v': 161 vflag++; 162 break; 163 default: 164 usage(); 165 /* NOTREACHED */ 166 } 167 } 168 argc -= optind; 169 argv += optind; 170 171 if (vflag && fmt1 != NULL) 172 errx(1, "-v may not be used with -f"); 173 174 if (argc <= 0) { 175 usage(); 176 /* NOTREACHED */ 177 } 178 179 #ifdef __i386__ 180 if (vflag) { 181 for (c = 0; c < argc; c++) 182 dump_file(argv[c]); 183 exit(error_count == 0 ? EXIT_SUCCESS : EXIT_FAILURE); 184 } 185 #endif 186 187 rval = 0; 188 for (; argc > 0; argc--, argv++) { 189 int fd, status, is_shlib, rv, type; 190 191 if ((fd = open(*argv, O_RDONLY, 0)) < 0) { 192 warn("%s", *argv); 193 rval |= 1; 194 continue; 195 } 196 rv = is_executable(*argv, fd, &is_shlib, &type); 197 close(fd); 198 if (rv == 0) { 199 rval |= 1; 200 continue; 201 } 202 203 switch (type) { 204 case TYPE_ELF: 205 case TYPE_AOUT: 206 break; 207 #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) 208 case TYPE_ELF32: 209 rval |= execldd32(*argv, fmt1, fmt2, aflag, vflag); 210 continue; 211 #endif 212 case TYPE_UNKNOWN: 213 default: 214 /* 215 * This shouldn't happen unless is_executable() 216 * is broken. 217 */ 218 errx(EDOOFUS, "unknown executable type"); 219 } 220 221 /* ld.so magic */ 222 LDD_SETENV("TRACE_LOADED_OBJECTS", "yes", 1); 223 if (fmt1 != NULL) 224 LDD_SETENV("TRACE_LOADED_OBJECTS_FMT1", fmt1, 1); 225 if (fmt2 != NULL) 226 LDD_SETENV("TRACE_LOADED_OBJECTS_FMT2", fmt2, 1); 227 228 LDD_SETENV("TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1); 229 if (aflag) 230 LDD_SETENV("TRACE_LOADED_OBJECTS_ALL", "1", 1); 231 else if (fmt1 == NULL && fmt2 == NULL) 232 /* Default formats */ 233 printf("%s:\n", *argv); 234 fflush(stdout); 235 236 switch (fork()) { 237 case -1: 238 err(1, "fork"); 239 break; 240 default: 241 if (wait(&status) < 0) { 242 warn("wait"); 243 rval |= 1; 244 } else if (WIFSIGNALED(status)) { 245 fprintf(stderr, "%s: signal %d\n", *argv, 246 WTERMSIG(status)); 247 rval |= 1; 248 } else if (WIFEXITED(status) && 249 WEXITSTATUS(status) != 0) { 250 fprintf(stderr, "%s: exit status %d\n", *argv, 251 WEXITSTATUS(status)); 252 rval |= 1; 253 } 254 break; 255 case 0: 256 if (is_shlib == 0) { 257 execl(*argv, *argv, (char *)NULL); 258 warn("%s", *argv); 259 } else { 260 dlopen(*argv, RTLD_TRACE); 261 warnx("%s: %s", *argv, dlerror()); 262 } 263 _exit(1); 264 } 265 } 266 267 return rval; 268 } 269 270 static void 271 usage(void) 272 { 273 274 fprintf(stderr, "usage: ldd [-a] [-v] [-f format] program ...\n"); 275 exit(1); 276 } 277 278 static int 279 is_executable(const char *fname, int fd, int *is_shlib, int *type) 280 { 281 union { 282 #ifdef AOUT_SUPPORTED 283 struct exec aout; 284 #endif 285 #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) 286 Elf32_Ehdr elf32; 287 #endif 288 Elf_Ehdr elf; 289 } hdr; 290 int n; 291 292 *is_shlib = 0; 293 *type = TYPE_UNKNOWN; 294 295 if ((n = read(fd, &hdr, sizeof(hdr))) == -1) { 296 warn("%s: can't read program header", fname); 297 return (0); 298 } 299 300 #ifdef AOUT_SUPPORTED 301 if ((size_t)n >= sizeof(hdr.aout) && !N_BADMAG(hdr.aout)) { 302 /* a.out file */ 303 if ((N_GETFLAG(hdr.aout) & EX_DPMASK) != EX_DYNAMIC 304 #if 1 /* Compatibility */ 305 || hdr.aout.a_entry < __LDPGSZ 306 #endif 307 ) { 308 warnx("%s: not a dynamic executable", fname); 309 return (0); 310 } 311 *type = TYPE_AOUT; 312 return (1); 313 } 314 #endif 315 316 #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) 317 if ((size_t)n >= sizeof(hdr.elf32) && IS_ELF(hdr.elf32) && 318 hdr.elf32.e_ident[EI_CLASS] == ELFCLASS32) { 319 /* Handle 32 bit ELF objects */ 320 Elf32_Phdr phdr; 321 int dynamic, i; 322 323 dynamic = 0; 324 *type = TYPE_ELF32; 325 326 if (lseek(fd, hdr.elf32.e_phoff, SEEK_SET) == -1) { 327 warnx("%s: header too short", fname); 328 return (0); 329 } 330 for (i = 0; i < hdr.elf32.e_phnum; i++) { 331 if (read(fd, &phdr, hdr.elf32.e_phentsize) != 332 sizeof(phdr)) { 333 warnx("%s: can't read program header", fname); 334 return (0); 335 } 336 if (phdr.p_type == PT_DYNAMIC) { 337 dynamic = 1; 338 break; 339 } 340 } 341 342 if (!dynamic) { 343 warnx("%s: not a dynamic ELF executable", fname); 344 return (0); 345 } 346 if (hdr.elf32.e_type == ET_DYN) { 347 if (hdr.elf32.e_ident[EI_OSABI] == ELFOSABI_FREEBSD) { 348 *is_shlib = 1; 349 return (1); 350 } 351 warnx("%s: not a FreeBSD ELF shared object", fname); 352 return (0); 353 } 354 355 return (1); 356 } 357 #endif 358 359 if ((size_t)n >= sizeof(hdr.elf) && IS_ELF(hdr.elf) && 360 hdr.elf.e_ident[EI_CLASS] == ELF_TARG_CLASS) { 361 /* Handle default ELF objects on this architecture */ 362 Elf_Phdr phdr; 363 int dynamic, i; 364 365 dynamic = 0; 366 *type = TYPE_ELF; 367 368 if (lseek(fd, hdr.elf.e_phoff, SEEK_SET) == -1) { 369 warnx("%s: header too short", fname); 370 return (0); 371 } 372 for (i = 0; i < hdr.elf.e_phnum; i++) { 373 if (read(fd, &phdr, hdr.elf.e_phentsize) 374 != sizeof(phdr)) { 375 warnx("%s: can't read program header", fname); 376 return (0); 377 } 378 if (phdr.p_type == PT_DYNAMIC) { 379 dynamic = 1; 380 break; 381 } 382 } 383 384 if (!dynamic) { 385 warnx("%s: not a dynamic ELF executable", fname); 386 return (0); 387 } 388 if (hdr.elf.e_type == ET_DYN) { 389 switch (hdr.elf.e_ident[EI_OSABI]) { 390 case ELFOSABI_FREEBSD: 391 *is_shlib = 1; 392 return (1); 393 #ifdef __ARM_EABI__ 394 case ELFOSABI_NONE: 395 if (hdr.elf.e_machine != EM_ARM) 396 break; 397 if (EF_ARM_EABI_VERSION(hdr.elf.e_flags) < 398 EF_ARM_EABI_FREEBSD_MIN) 399 break; 400 *is_shlib = 1; 401 return (1); 402 #endif 403 } 404 warnx("%s: not a FreeBSD ELF shared object", fname); 405 return (0); 406 } 407 408 return (1); 409 } 410 411 warnx("%s: not a dynamic executable", fname); 412 return (0); 413 } 414