1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1993 Paul Kranenburg 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Paul Kranenburg. 18 * 4. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include <sys/wait.h> 37 38 #include <machine/elf.h> 39 40 #include <arpa/inet.h> 41 42 #include <dlfcn.h> 43 #include <err.h> 44 #include <errno.h> 45 #include <fcntl.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <unistd.h> 50 51 /* 52 * 32-bit ELF data structures can only be used if the system header[s] declare 53 * them. There is no official macro for determining whether they are declared, 54 * so check for the existence of one of the 32-macros defined in elf(5). 55 */ 56 #ifdef ELF32_R_TYPE 57 #define ELF32_SUPPORTED 58 #endif 59 60 #define LDD_SETENV(name, value, overwrite) do { \ 61 setenv("LD_" name, value, overwrite); \ 62 setenv("LD_32_" name, value, overwrite); \ 63 } while (0) 64 65 #define LDD_UNSETENV(name) do { \ 66 unsetenv("LD_" name); \ 67 unsetenv("LD_32_" name); \ 68 } while (0) 69 70 static int is_executable(const char *fname, int fd, int *is_shlib, 71 int *type); 72 static void usage(void); 73 74 #define TYPE_UNKNOWN 0 75 #define TYPE_ELF 1 /* Architecture default */ 76 #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) 77 #define TYPE_ELF32 2 /* Explicit 32 bits on architectures >32 bits */ 78 79 #define _PATH_LDD32 "/usr/bin/ldd32" 80 81 static int 82 execldd32(char *file, char *fmt1, char *fmt2, int aflag, int vflag) 83 { 84 char *argv[9]; 85 int i, rval, status; 86 87 LDD_UNSETENV("TRACE_LOADED_OBJECTS"); 88 rval = 0; 89 i = 0; 90 argv[i++] = strdup(_PATH_LDD32); 91 if (aflag) 92 argv[i++] = strdup("-a"); 93 if (vflag) 94 argv[i++] = strdup("-v"); 95 if (fmt1 != NULL) { 96 argv[i++] = strdup("-f"); 97 argv[i++] = strdup(fmt1); 98 } 99 if (fmt2 != NULL) { 100 argv[i++] = strdup("-f"); 101 argv[i++] = strdup(fmt2); 102 } 103 argv[i++] = strdup(file); 104 argv[i++] = NULL; 105 106 switch (fork()) { 107 case -1: 108 err(1, "fork"); 109 break; 110 case 0: 111 execv(_PATH_LDD32, argv); 112 warn("%s", _PATH_LDD32); 113 _exit(127); 114 break; 115 default: 116 if (wait(&status) < 0) 117 rval = 1; 118 else if (WIFSIGNALED(status)) 119 rval = 1; 120 else if (WIFEXITED(status) && WEXITSTATUS(status) != 0) 121 rval = 1; 122 break; 123 } 124 while (i--) 125 free(argv[i]); 126 LDD_SETENV("TRACE_LOADED_OBJECTS", "yes", 1); 127 return (rval); 128 } 129 #endif 130 131 int 132 main(int argc, char *argv[]) 133 { 134 char *fmt1, *fmt2; 135 int rval, c, aflag, vflag; 136 137 aflag = vflag = 0; 138 fmt1 = fmt2 = NULL; 139 140 while ((c = getopt(argc, argv, "af:v")) != -1) { 141 switch (c) { 142 case 'a': 143 aflag++; 144 break; 145 case 'f': 146 if (fmt1 != NULL) { 147 if (fmt2 != NULL) 148 errx(1, "too many formats"); 149 fmt2 = optarg; 150 } else 151 fmt1 = optarg; 152 break; 153 case 'v': 154 vflag++; 155 break; 156 default: 157 usage(); 158 /* NOTREACHED */ 159 } 160 } 161 argc -= optind; 162 argv += optind; 163 164 if (vflag && fmt1 != NULL) 165 errx(1, "-v may not be used with -f"); 166 167 if (argc <= 0) { 168 usage(); 169 /* NOTREACHED */ 170 } 171 172 rval = 0; 173 for (; argc > 0; argc--, argv++) { 174 int fd, status, is_shlib, rv, type; 175 176 if ((fd = open(*argv, O_RDONLY, 0)) < 0) { 177 warn("%s", *argv); 178 rval |= 1; 179 continue; 180 } 181 rv = is_executable(*argv, fd, &is_shlib, &type); 182 close(fd); 183 if (rv == 0) { 184 rval |= 1; 185 continue; 186 } 187 188 switch (type) { 189 case TYPE_ELF: 190 break; 191 #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) 192 case TYPE_ELF32: 193 rval |= execldd32(*argv, fmt1, fmt2, aflag, vflag); 194 continue; 195 #endif 196 case TYPE_UNKNOWN: 197 default: 198 /* 199 * This shouldn't happen unless is_executable() 200 * is broken. 201 */ 202 errx(EDOOFUS, "unknown executable type"); 203 } 204 205 /* ld.so magic */ 206 LDD_SETENV("TRACE_LOADED_OBJECTS", "yes", 1); 207 if (fmt1 != NULL) 208 LDD_SETENV("TRACE_LOADED_OBJECTS_FMT1", fmt1, 1); 209 if (fmt2 != NULL) 210 LDD_SETENV("TRACE_LOADED_OBJECTS_FMT2", fmt2, 1); 211 212 LDD_SETENV("TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1); 213 if (aflag) 214 LDD_SETENV("TRACE_LOADED_OBJECTS_ALL", "1", 1); 215 else if (fmt1 == NULL && fmt2 == NULL) 216 /* Default formats */ 217 printf("%s:\n", *argv); 218 fflush(stdout); 219 220 switch (fork()) { 221 case -1: 222 err(1, "fork"); 223 break; 224 default: 225 if (wait(&status) < 0) { 226 warn("wait"); 227 rval |= 1; 228 } else if (WIFSIGNALED(status)) { 229 fprintf(stderr, "%s: signal %d\n", *argv, 230 WTERMSIG(status)); 231 rval |= 1; 232 } else if (WIFEXITED(status) && 233 WEXITSTATUS(status) != 0) { 234 fprintf(stderr, "%s: exit status %d\n", *argv, 235 WEXITSTATUS(status)); 236 rval |= 1; 237 } 238 break; 239 case 0: 240 if (is_shlib == 0) { 241 execl(*argv, *argv, (char *)NULL); 242 warn("%s", *argv); 243 } else { 244 dlopen(*argv, RTLD_TRACE); 245 warnx("%s: %s", *argv, dlerror()); 246 } 247 _exit(1); 248 } 249 } 250 251 return rval; 252 } 253 254 static void 255 usage(void) 256 { 257 258 fprintf(stderr, "usage: ldd [-a] [-v] [-f format] program ...\n"); 259 exit(1); 260 } 261 262 static int 263 is_executable(const char *fname, int fd, int *is_shlib, int *type) 264 { 265 union { 266 #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) 267 Elf32_Ehdr elf32; 268 #endif 269 Elf_Ehdr elf; 270 } hdr; 271 Elf_Phdr phdr, dynphdr; 272 Elf_Dyn *dynp; 273 void *dyndata; 274 #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) 275 Elf32_Phdr phdr32, dynphdr32; 276 Elf32_Dyn *dynp32; 277 #endif 278 int df1pie, dynamic, i, n; 279 280 *is_shlib = 0; 281 *type = TYPE_UNKNOWN; 282 df1pie = 0; 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 __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) 290 if ((size_t)n >= sizeof(hdr.elf32) && IS_ELF(hdr.elf32) && 291 hdr.elf32.e_ident[EI_CLASS] == ELFCLASS32) { 292 /* Handle 32 bit ELF objects */ 293 294 dynamic = 0; 295 *type = TYPE_ELF32; 296 297 if (lseek(fd, hdr.elf32.e_phoff, SEEK_SET) == -1) { 298 warnx("%s: header too short", fname); 299 return (0); 300 } 301 for (i = 0; i < hdr.elf32.e_phnum; i++) { 302 if (read(fd, &phdr32, hdr.elf32.e_phentsize) != 303 sizeof(phdr32)) { 304 warnx("%s: can't read program header", fname); 305 return (0); 306 } 307 if (phdr32.p_type == PT_DYNAMIC) { 308 dynamic = 1; 309 dynphdr32 = phdr32; 310 break; 311 } 312 } 313 314 if (!dynamic) { 315 warnx("%s: not a dynamic ELF executable", fname); 316 return (0); 317 } 318 319 if (hdr.elf32.e_type == ET_DYN) { 320 if (lseek(fd, dynphdr32.p_offset, SEEK_SET) == -1) { 321 warnx("%s: dynamic segment out of range", 322 fname); 323 return (0); 324 } 325 dyndata = malloc(dynphdr32.p_filesz); 326 if (dyndata == NULL) { 327 warn("malloc"); 328 return (0); 329 } 330 if (read(fd, dyndata, dynphdr32.p_filesz) != 331 (ssize_t)dynphdr32.p_filesz) { 332 free(dyndata); 333 warnx("%s: can't read dynamic segment", fname); 334 return (0); 335 } 336 for (dynp32 = dyndata; dynp32->d_tag != DT_NULL; 337 dynp32++) { 338 if (dynp32->d_tag != DT_FLAGS_1) 339 continue; 340 df1pie = (dynp32->d_un.d_val & DF_1_PIE) != 0; 341 break; 342 } 343 free(dyndata); 344 345 if (hdr.elf32.e_ident[EI_OSABI] == ELFOSABI_FREEBSD) { 346 if (!df1pie) 347 *is_shlib = 1; 348 return (1); 349 } 350 warnx("%s: not a FreeBSD ELF shared object", fname); 351 return (0); 352 } 353 354 return (1); 355 } 356 #endif 357 358 if ((size_t)n >= sizeof(hdr.elf) && IS_ELF(hdr.elf) && 359 hdr.elf.e_ident[EI_CLASS] == ELF_TARG_CLASS) { 360 /* Handle default ELF objects on this architecture */ 361 362 dynamic = 0; 363 *type = TYPE_ELF; 364 365 if (lseek(fd, hdr.elf.e_phoff, SEEK_SET) == -1) { 366 warnx("%s: header too short", fname); 367 return (0); 368 } 369 for (i = 0; i < hdr.elf.e_phnum; i++) { 370 if (read(fd, &phdr, hdr.elf.e_phentsize) 371 != sizeof(phdr)) { 372 warnx("%s: can't read program header", fname); 373 return (0); 374 } 375 if (phdr.p_type == PT_DYNAMIC) { 376 dynamic = 1; 377 dynphdr = phdr; 378 break; 379 } 380 } 381 382 if (!dynamic) { 383 warnx("%s: not a dynamic ELF executable", fname); 384 return (0); 385 } 386 387 if (hdr.elf.e_type == ET_DYN) { 388 if (lseek(fd, dynphdr.p_offset, SEEK_SET) == -1) { 389 warnx("%s: dynamic segment out of range", 390 fname); 391 return (0); 392 } 393 dyndata = malloc(dynphdr.p_filesz); 394 if (dyndata == NULL) { 395 warn("malloc"); 396 return (0); 397 } 398 if (read(fd, dyndata, dynphdr.p_filesz) != 399 (ssize_t)dynphdr.p_filesz) { 400 free(dyndata); 401 warnx("%s: can't read dynamic segment", fname); 402 return (0); 403 } 404 for (dynp = dyndata; dynp->d_tag != DT_NULL; dynp++) { 405 if (dynp->d_tag != DT_FLAGS_1) 406 continue; 407 df1pie = (dynp->d_un.d_val & DF_1_PIE) != 0; 408 break; 409 } 410 free(dyndata); 411 412 switch (hdr.elf.e_ident[EI_OSABI]) { 413 case ELFOSABI_FREEBSD: 414 if (!df1pie) 415 *is_shlib = 1; 416 return (1); 417 #ifdef __ARM_EABI__ 418 case ELFOSABI_NONE: 419 if (hdr.elf.e_machine != EM_ARM) 420 break; 421 if (EF_ARM_EABI_VERSION(hdr.elf.e_flags) < 422 EF_ARM_EABI_FREEBSD_MIN) 423 break; 424 *is_shlib = 1; 425 return (1); 426 #endif 427 } 428 warnx("%s: not a FreeBSD ELF shared object", fname); 429 return (0); 430 } 431 432 return (1); 433 } 434 435 warnx("%s: not a dynamic executable", fname); 436 return (0); 437 } 438