contrib/file/readelf.c

   1 /*
   2  * Copyright (c) Christos Zoulas 2003.
   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 immediately at the beginning of the file, without modification,
  10  *    this list of conditions, and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  19  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  */
  27 #include "file.h"
  28
  29 #ifndef lint
  30 FILE_RCSID("@(#)$File: readelf.c,v 1.81 2008/11/04 16:38:28 christos Exp $")
  31 #endif
  32
  33 #ifdef BUILTIN_ELF
  34 #include <string.h>
  35 #include <ctype.h>
  36 #include <stdlib.h>
  37 #ifdef HAVE_UNISTD_H
  38 #include <unistd.h>
  39 #endif
  40
  41 #include "readelf.h"
  42 #include "magic.h"
  43
  44 #ifdef  ELFCORE
  45 private int dophn_core(struct magic_set *, int, int, int, off_t, int, size_t,
  46     off_t, int *);
  47 #endif
  48 private int dophn_exec(struct magic_set *, int, int, int, off_t, int, size_t,
  49     off_t, int *, int);
  50 private int doshn(struct magic_set *, int, int, int, off_t, int, size_t, int *,
  51     int);
  52 private size_t donote(struct magic_set *, void *, size_t, size_t, int,
  53     int, size_t, int *);
  54
  55 #define ELF_ALIGN(a)    ((((a) + align - 1) / align) * align)
  56
  57 #define isquote(c) (strchr("'\"`", (c)) != NULL)
  58
  59 private uint16_t getu16(int, uint16_t);
  60 private uint32_t getu32(int, uint32_t);
  61 private uint64_t getu64(int, uint64_t);
  62
  63 #define MAX_PHNUM       256
  64 #define MAX_SHNUM       1024
  65
  66 private int
  67 toomany(struct magic_set *ms, const char *name, uint16_t num)
  68 {
  69         if (file_printf(ms, ", too many %s header sections (%u)", name, num
  70             ) == -1)
  71                 return -1;
  72         return 0;
  73 }
  74
  75 private uint16_t
  76 getu16(int swap, uint16_t value)
  77 {
  78         union {
  79                 uint16_t ui;
  80                 char c[2];
  81         } retval, tmpval;
  82
  83         if (swap) {
  84                 tmpval.ui = value;
  85
  86                 retval.c[0] = tmpval.c[1];
  87                 retval.c[1] = tmpval.c[0];
  88
  89                 return retval.ui;
  90         } else
  91                 return value;
  92 }
  93
  94 private uint32_t
  95 getu32(int swap, uint32_t value)
  96 {
  97         union {
  98                 uint32_t ui;
  99                 char c[4];
 100         } retval, tmpval;
 101
 102         if (swap) {
 103                 tmpval.ui = value;
 104
 105                 retval.c[0] = tmpval.c[3];
 106                 retval.c[1] = tmpval.c[2];
 107                 retval.c[2] = tmpval.c[1];
 108                 retval.c[3] = tmpval.c[0];
 109
 110                 return retval.ui;
 111         } else
 112                 return value;
 113 }
 114
 115 private uint64_t
 116 getu64(int swap, uint64_t value)
 117 {
 118         union {
 119                 uint64_t ui;
 120                 char c[8];
 121         } retval, tmpval;
 122
 123         if (swap) {
 124                 tmpval.ui = value;
 125
 126                 retval.c[0] = tmpval.c[7];
 127                 retval.c[1] = tmpval.c[6];
 128                 retval.c[2] = tmpval.c[5];
 129                 retval.c[3] = tmpval.c[4];
 130                 retval.c[4] = tmpval.c[3];
 131                 retval.c[5] = tmpval.c[2];
 132                 retval.c[6] = tmpval.c[1];
 133                 retval.c[7] = tmpval.c[0];
 134
 135                 return retval.ui;
 136         } else
 137                 return value;
 138 }
 139
 140 #define elf_getu16(swap, value) getu16(swap, value)
 141 #define elf_getu32(swap, value) getu32(swap, value)
 142 #ifdef USE_ARRAY_FOR_64BIT_TYPES
 143 # define elf_getu64(swap, array) \
 144         ((swap ? ((uint64_t)elf_getu32(swap, array[0])) << 32 : elf_getu32(swap, array[0])) + \
 145          (swap ? elf_getu32(swap, array[1]) : ((uint64_t)elf_getu32(swap, array[1]) << 32)))
 146 #else
 147 # define elf_getu64(swap, value) getu64(swap, value)
 148 #endif
 149
 150 #define xsh_addr        (clazz == ELFCLASS32                    \
 151                          ? (void *) &sh32                       \
 152                          : (void *) &sh64)
 153 #define xsh_sizeof      (clazz == ELFCLASS32                    \
 154                          ? sizeof sh32                          \
 155                          : sizeof sh64)
 156 #define xsh_size        (clazz == ELFCLASS32                    \
 157                          ? elf_getu32(swap, sh32.sh_size)       \
 158                          : elf_getu64(swap, sh64.sh_size))
 159 #define xsh_offset      (clazz == ELFCLASS32                    \
 160                          ? elf_getu32(swap, sh32.sh_offset)     \
 161                          : elf_getu64(swap, sh64.sh_offset))
 162 #define xsh_type        (clazz == ELFCLASS32                    \
 163                          ? elf_getu32(swap, sh32.sh_type)       \
 164                          : elf_getu32(swap, sh64.sh_type))
 165 #define xph_addr        (clazz == ELFCLASS32                    \
 166                          ? (void *) &ph32                       \
 167                          : (void *) &ph64)
 168 #define xph_sizeof      (clazz == ELFCLASS32                    \
 169                          ? sizeof ph32                          \
 170                          : sizeof ph64)
 171 #define xph_type        (clazz == ELFCLASS32                    \
 172                          ? elf_getu32(swap, ph32.p_type)        \
 173                          : elf_getu32(swap, ph64.p_type))
 174 #define xph_offset      (off_t)(clazz == ELFCLASS32             \
 175                          ? elf_getu32(swap, ph32.p_offset)      \
 176                          : elf_getu64(swap, ph64.p_offset))
 177 #define xph_align       (size_t)((clazz == ELFCLASS32           \
 178                          ? (off_t) (ph32.p_align ?              \
 179                             elf_getu32(swap, ph32.p_align) : 4) \
 180                          : (off_t) (ph64.p_align ?              \
 181                             elf_getu64(swap, ph64.p_align) : 4)))
 182 #define xph_filesz      (size_t)((clazz == ELFCLASS32           \
 183                          ? elf_getu32(swap, ph32.p_filesz)      \
 184                          : elf_getu64(swap, ph64.p_filesz)))
 185 #define xnh_addr        (clazz == ELFCLASS32                    \
 186                          ? (void *) &nh32                       \
 187                          : (void *) &nh64)
 188 #define xph_memsz       (size_t)((clazz == ELFCLASS32           \
 189                          ? elf_getu32(swap, ph32.p_memsz)       \
 190                          : elf_getu64(swap, ph64.p_memsz)))
 191 #define xnh_sizeof      (clazz == ELFCLASS32                    \
 192                          ? sizeof nh32                          \
 193                          : sizeof nh64)
 194 #define xnh_type        (clazz == ELFCLASS32                    \
 195                          ? elf_getu32(swap, nh32.n_type)        \
 196                          : elf_getu32(swap, nh64.n_type))
 197 #define xnh_namesz      (clazz == ELFCLASS32                    \
 198                          ? elf_getu32(swap, nh32.n_namesz)      \
 199                          : elf_getu32(swap, nh64.n_namesz))
 200 #define xnh_descsz      (clazz == ELFCLASS32                    \
 201                          ? elf_getu32(swap, nh32.n_descsz)      \
 202                          : elf_getu32(swap, nh64.n_descsz))
 203 #define prpsoffsets(i)  (clazz == ELFCLASS32                    \
 204                          ? prpsoffsets32[i]                     \
 205                          : prpsoffsets64[i])
 206 #define xcap_addr       (clazz == ELFCLASS32                    \
 207                          ? (void *) &cap32                      \
 208                          : (void *) &cap64)
 209 #define xcap_sizeof     (clazz == ELFCLASS32                    \
 210                          ? sizeof cap32                         \
 211                          : sizeof cap64)
 212 #define xcap_tag        (clazz == ELFCLASS32                    \
 213                          ? elf_getu32(swap, cap32.c_tag)        \
 214                          : elf_getu64(swap, cap64.c_tag))
 215 #define xcap_val        (clazz == ELFCLASS32                    \
 216                          ? elf_getu32(swap, cap32.c_un.c_val)   \
 217                          : elf_getu64(swap, cap64.c_un.c_val))
 218
 219 #ifdef ELFCORE
 220 /*
 221  * Try larger offsets first to avoid false matches
 222  * from earlier data that happen to look like strings.
 223  */
 224 static const size_t     prpsoffsets32[] = {
 225 #ifdef USE_NT_PSINFO
 226         104,            /* SunOS 5.x (command line) */
 227         88,             /* SunOS 5.x (short name) */
 228 #endif /* USE_NT_PSINFO */
 229
 230         100,            /* SunOS 5.x (command line) */
 231         84,             /* SunOS 5.x (short name) */
 232
 233         44,             /* Linux (command line) */
 234         28,             /* Linux 2.0.36 (short name) */
 235
 236         8,              /* FreeBSD */
 237 };
 238
 239 static const size_t     prpsoffsets64[] = {
 240 #ifdef USE_NT_PSINFO
 241         152,            /* SunOS 5.x (command line) */
 242         136,            /* SunOS 5.x (short name) */
 243 #endif /* USE_NT_PSINFO */
 244
 245         136,            /* SunOS 5.x, 64-bit (command line) */
 246         120,            /* SunOS 5.x, 64-bit (short name) */
 247
 248         56,             /* Linux (command line) */
 249         40,             /* Linux (tested on core from 2.4.x, short name) */
 250
 251         16,             /* FreeBSD, 64-bit */
 252 };
 253
 254 #define NOFFSETS32      (sizeof prpsoffsets32 / sizeof prpsoffsets32[0])
 255 #define NOFFSETS64      (sizeof prpsoffsets64 / sizeof prpsoffsets64[0])
 256
 257 #define NOFFSETS        (clazz == ELFCLASS32 ? NOFFSETS32 : NOFFSETS64)
 258
 259 /*
 260  * Look through the program headers of an executable image, searching
 261  * for a PT_NOTE section of type NT_PRPSINFO, with a name "CORE" or
 262  * "FreeBSD"; if one is found, try looking in various places in its
 263  * contents for a 16-character string containing only printable
 264  * characters - if found, that string should be the name of the program
 265  * that dropped core.  Note: right after that 16-character string is,
 266  * at least in SunOS 5.x (and possibly other SVR4-flavored systems) and
 267  * Linux, a longer string (80 characters, in 5.x, probably other
 268  * SVR4-flavored systems, and Linux) containing the start of the
 269  * command line for that program.
 270  *
 271  * SunOS 5.x core files contain two PT_NOTE sections, with the types
 272  * NT_PRPSINFO (old) and NT_PSINFO (new).  These structs contain the
 273  * same info about the command name and command line, so it probably
 274  * isn't worthwhile to look for NT_PSINFO, but the offsets are provided
 275  * above (see USE_NT_PSINFO), in case we ever decide to do so.  The
 276  * NT_PRPSINFO and NT_PSINFO sections are always in order and adjacent;
 277  * the SunOS 5.x file command relies on this (and prefers the latter).
 278  *
 279  * The signal number probably appears in a section of type NT_PRSTATUS,
 280  * but that's also rather OS-dependent, in ways that are harder to
 281  * dissect with heuristics, so I'm not bothering with the signal number.
 282  * (I suppose the signal number could be of interest in situations where
 283  * you don't have the binary of the program that dropped core; if you
 284  * *do* have that binary, the debugger will probably tell you what
 285  * signal it was.)
 286  */
 287
 288 #define OS_STYLE_SVR4           0
 289 #define OS_STYLE_FREEBSD        1
 290 #define OS_STYLE_NETBSD         2
 291
 292 private const char os_style_names[][8] = {
 293         "SVR4",
 294         "FreeBSD",
 295         "NetBSD",
 296 };
 297
 298 #define FLAGS_DID_CORE          1
 299 #define FLAGS_DID_NOTE          2
 300 #define FLAGS_DID_CORE_STYLE    4
 301
 302 private int
 303 dophn_core(struct magic_set *ms, int clazz, int swap, int fd, off_t off,
 304     int num, size_t size, off_t fsize, int *flags)
 305 {
 306         Elf32_Phdr ph32;
 307         Elf64_Phdr ph64;
 308         size_t offset;
 309         unsigned char nbuf[BUFSIZ];
 310         ssize_t bufsize;
 311         off_t savedoffset;
 312         struct stat st;
 313
 314         if (fstat(fd, &st) < 0) {
 315                 file_badread(ms);
 316                 return -1;
 317         }
 318
 319         if (size != xph_sizeof) {
 320                 if (file_printf(ms, ", corrupted program header size") == -1)
 321                         return -1;
 322                 return 0;
 323         }
 324
 325         /*
 326          * Loop through all the program headers.
 327          */
 328         for ( ; num; num--) {
 329                 if ((savedoffset = lseek(fd, off, SEEK_SET)) == (off_t)-1) {
 330                         file_badseek(ms);
 331                         return -1;
 332                 }
 333                 if (read(fd, xph_addr, xph_sizeof) == -1) {
 334                         file_badread(ms);
 335                         return -1;
 336                 }
 337                 if (xph_offset > fsize) {
 338                         if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
 339                                 file_badseek(ms);
 340                                 return -1;
 341                         }
 342                         continue;
 343                 }
 344
 345                 off += size;
 346                 if (xph_type != PT_NOTE)
 347                         continue;
 348
 349                 /*
 350                  * This is a PT_NOTE section; loop through all the notes
 351                  * in the section.
 352                  */
 353                 if (lseek(fd, xph_offset, SEEK_SET) == (off_t)-1) {
 354                         file_badseek(ms);
 355                         return -1;
 356                 }
 357                 bufsize = read(fd, nbuf,
 358                     ((xph_filesz < sizeof(nbuf)) ? xph_filesz : sizeof(nbuf)));
 359                 if (bufsize == -1) {
 360                         file_badread(ms);
 361                         return -1;
 362                 }
 363                 offset = 0;
 364                 for (;;) {
 365                         if (offset >= (size_t)bufsize)
 366                                 break;
 367                         offset = donote(ms, nbuf, offset, (size_t)bufsize,
 368                             clazz, swap, 4, flags);
 369                         if (offset == 0)
 370                                 break;
 371
 372                 }
 373         }
 374         return 0;
 375 }
 376 #endif
 377
 378 private size_t
 379 donote(struct magic_set *ms, void *vbuf, size_t offset, size_t size,
 380     int clazz, int swap, size_t align, int *flags)
 381 {
 382         Elf32_Nhdr nh32;
 383         Elf64_Nhdr nh64;
 384         size_t noff, doff;
 385 #ifdef ELFCORE
 386         int os_style = -1;
 387 #endif
 388         uint32_t namesz, descsz;
 389         unsigned char *nbuf = CAST(unsigned char *, vbuf);
 390
 391         (void)memcpy(xnh_addr, &nbuf[offset], xnh_sizeof);
 392         offset += xnh_sizeof;
 393
 394         namesz = xnh_namesz;
 395         descsz = xnh_descsz;
 396         if ((namesz == 0) && (descsz == 0)) {
 397                 /*
 398                  * We're out of note headers.
 399                  */
 400                 return (offset >= size) ? offset : size;
 401         }
 402
 403         if (namesz & 0x80000000) {
 404             (void)file_printf(ms, ", bad note name size 0x%lx",
 405                 (unsigned long)namesz);
 406             return 0;
 407         }
 408
 409         if (descsz & 0x80000000) {
 410             (void)file_printf(ms, ", bad note description size 0x%lx",
 411                 (unsigned long)descsz);
 412             return 0;
 413         }
 414
 415
 416         noff = offset;
 417         doff = ELF_ALIGN(offset + namesz);
 418
 419         if (offset + namesz > size) {
 420                 /*
 421                  * We're past the end of the buffer.
 422                  */
 423                 return doff;
 424         }
 425
 426         offset = ELF_ALIGN(doff + descsz);
 427         if (doff + descsz > size) {
 428                 /*
 429                  * We're past the end of the buffer.
 430                  */
 431                 return (offset >= size) ? offset : size;
 432         }
 433
 434         if (*flags & FLAGS_DID_NOTE)
 435                 goto core;
 436
 437         if (namesz == 4 && strcmp((char *)&nbuf[noff], "GNU") == 0 &&
 438             xnh_type == NT_GNU_VERSION && descsz == 16) {
 439                 uint32_t desc[4];
 440                 (void)memcpy(desc, &nbuf[doff], sizeof(desc));
 441
 442                 if (file_printf(ms, ", for GNU/") == -1)
 443                         return size;
 444                 switch (elf_getu32(swap, desc[0])) {
 445                 case GNU_OS_LINUX:
 446                         if (file_printf(ms, "Linux") == -1)
 447                                 return size;
 448                         break;
 449                 case GNU_OS_HURD:
 450                         if (file_printf(ms, "Hurd") == -1)
 451                                 return size;
 452                         break;
 453                 case GNU_OS_SOLARIS:
 454                         if (file_printf(ms, "Solaris") == -1)
 455                                 return size;
 456                         break;
 457                 case GNU_OS_KFREEBSD:
 458                         if (file_printf(ms, "kFreeBSD") == -1)
 459                                 return size;
 460                         break;
 461                 case GNU_OS_KNETBSD:
 462                         if (file_printf(ms, "kNetBSD") == -1)
 463                                 return size;
 464                         break;
 465                 default:
 466                         if (file_printf(ms, "<unknown>") == -1)
 467                                 return size;
 468                 }
 469                 if (file_printf(ms, " %d.%d.%d", elf_getu32(swap, desc[1]),
 470                     elf_getu32(swap, desc[2]), elf_getu32(swap, desc[3])) == -1)
 471                         return size;
 472                 *flags |= FLAGS_DID_NOTE;
 473                 return size;
 474         }
 475
 476         if (namesz == 7 && strcmp((char *)&nbuf[noff], "NetBSD") == 0 &&
 477             xnh_type == NT_NETBSD_VERSION && descsz == 4) {
 478                 uint32_t desc;
 479                 (void)memcpy(&desc, &nbuf[doff], sizeof(desc));
 480                 desc = elf_getu32(swap, desc);
 481
 482                 if (file_printf(ms, ", for NetBSD") == -1)
 483                         return size;
 484                 /*
 485                  * The version number used to be stuck as 199905, and was thus
 486                  * basically content-free.  Newer versions of NetBSD have fixed
 487                  * this and now use the encoding of __NetBSD_Version__:
 488                  *
 489                  *      MMmmrrpp00
 490                  *
 491                  * M = major version
 492                  * m = minor version
 493                  * r = release ["",A-Z,Z[A-Z] but numeric]
 494                  * p = patchlevel
 495                  */
 496                 if (desc > 100000000U) {
 497                         uint32_t ver_patch = (desc / 100) % 100;
 498                         uint32_t ver_rel = (desc / 10000) % 100;
 499                         uint32_t ver_min = (desc / 1000000) % 100;
 500                         uint32_t ver_maj = desc / 100000000;
 501
 502                         if (file_printf(ms, " %u.%u", ver_maj, ver_min) == -1)
 503                                 return size;
 504                         if (ver_rel == 0 && ver_patch != 0) {
 505                                 if (file_printf(ms, ".%u", ver_patch) == -1)
 506                                         return size;
 507                         } else if (ver_rel != 0) {
 508                                 while (ver_rel > 26) {
 509                                         if (file_printf(ms, "Z") == -1)
 510                                                 return size;
 511                                         ver_rel -= 26;
 512                                 }
 513                                 if (file_printf(ms, "%c", 'A' + ver_rel - 1)
 514                                     == -1)
 515                                         return size;
 516                         }
 517                 }
 518                 *flags |= FLAGS_DID_NOTE;
 519                 return size;
 520         }
 521
 522         if (namesz == 8 && strcmp((char *)&nbuf[noff], "FreeBSD") == 0 &&
 523             xnh_type == NT_FREEBSD_VERSION && descsz == 4) {
 524                 uint32_t desc;
 525                 (void)memcpy(&desc, &nbuf[doff], sizeof(desc));
 526                 desc = elf_getu32(swap, desc);
 527                 if (file_printf(ms, ", for FreeBSD") == -1)
 528                         return size;
 529
 530                 /*
 531                  * Contents is __FreeBSD_version, whose relation to OS
 532                  * versions is defined by a huge table in the Porter's
 533                  * Handbook.  This is the general scheme:
 534                  *
 535                  * Releases:
 536                  *      Mmp000 (before 4.10)
 537                  *      Mmi0p0 (before 5.0)
 538                  *      Mmm0p0
 539                  *
 540                  * Development branches:
 541                  *      Mmpxxx (before 4.6)
 542                  *      Mmp1xx (before 4.10)
 543                  *      Mmi1xx (before 5.0)
 544                  *      M000xx (pre-M.0)
 545                  *      Mmm1xx
 546                  *
 547                  * M = major version
 548                  * m = minor version
 549                  * i = minor version increment (491000 -> 4.10)
 550                  * p = patchlevel
 551                  * x = revision
 552                  *
 553                  * The first release of FreeBSD to use ELF by default
 554                  * was version 3.0.
 555                  */
 556                 if (desc == 460002) {
 557                         if (file_printf(ms, " 4.6.2") == -1)
 558                                 return size;
 559                 } else if (desc < 460100) {
 560                         if (file_printf(ms, " %d.%d", desc / 100000,
 561                             desc / 10000 % 10) == -1)
 562                                 return size;
 563                         if (desc / 1000 % 10 > 0)
 564                                 if (file_printf(ms, ".%d", desc / 1000 % 10)
 565                                     == -1)
 566                                         return size;
 567                         if ((desc % 1000 > 0) || (desc % 100000 == 0))
 568                                 if (file_printf(ms, " (%d)", desc) == -1)
 569                                         return size;
 570                 } else if (desc < 500000) {
 571                         if (file_printf(ms, " %d.%d", desc / 100000,
 572                             desc / 10000 % 10 + desc / 1000 % 10) == -1)
 573                                 return size;
 574                         if (desc / 100 % 10 > 0) {
 575                                 if (file_printf(ms, " (%d)", desc) == -1)
 576                                         return size;
 577                         } else if (desc / 10 % 10 > 0) {
 578                                 if (file_printf(ms, ".%d", desc / 10 % 10)
 579                                     == -1)
 580                                         return size;
 581                         }
 582                 } else {
 583                         if (file_printf(ms, " %d.%d", desc / 100000,
 584                             desc / 1000 % 100) == -1)
 585                                 return size;
 586                         if ((desc / 100 % 10 > 0) ||
 587                             (desc % 100000 / 100 == 0)) {
 588                                 if (file_printf(ms, " (%d)", desc) == -1)
 589                                         return size;
 590                         } else if (desc / 10 % 10 > 0) {
 591                                 if (file_printf(ms, ".%d", desc / 10 % 10)
 592                                     == -1)
 593                                         return size;
 594                         }
 595                 }
 596                 *flags |= FLAGS_DID_NOTE;
 597                 return size;
 598         }
 599
 600         if (namesz == 8 && strcmp((char *)&nbuf[noff], "OpenBSD") == 0 &&
 601             xnh_type == NT_OPENBSD_VERSION && descsz == 4) {
 602                 if (file_printf(ms, ", for OpenBSD") == -1)
 603                         return size;
 604                 /* Content of note is always 0 */
 605                 *flags |= FLAGS_DID_NOTE;
 606                 return size;
 607         }
 608
 609         if (namesz == 10 && strcmp((char *)&nbuf[noff], "DragonFly") == 0 &&
 610             xnh_type == NT_DRAGONFLY_VERSION && descsz == 4) {
 611                 uint32_t desc;
 612                 if (file_printf(ms, ", for DragonFly") == -1)
 613                         return size;
 614                 (void)memcpy(&desc, &nbuf[doff], sizeof(desc));
 615                 desc = elf_getu32(swap, desc);
 616                 if (file_printf(ms, " %d.%d.%d", desc / 100000,
 617                     desc / 10000 % 10, desc % 10000) == -1)
 618                         return size;
 619                 *flags |= FLAGS_DID_NOTE;
 620                 return size;
 621         }
 622
 623 core:
 624         /*
 625          * Sigh.  The 2.0.36 kernel in Debian 2.1, at
 626          * least, doesn't correctly implement name
 627          * sections, in core dumps, as specified by
 628          * the "Program Linking" section of "UNIX(R) System
 629          * V Release 4 Programmer's Guide: ANSI C and
 630          * Programming Support Tools", because my copy
 631          * clearly says "The first 'namesz' bytes in 'name'
 632          * contain a *null-terminated* [emphasis mine]
 633          * character representation of the entry's owner
 634          * or originator", but the 2.0.36 kernel code
 635          * doesn't include the terminating null in the
 636          * name....
 637          */
 638         if ((namesz == 4 && strncmp((char *)&nbuf[noff], "CORE", 4) == 0) ||
 639             (namesz == 5 && strcmp((char *)&nbuf[noff], "CORE") == 0)) {
 640                 os_style = OS_STYLE_SVR4;
 641         }
 642
 643         if ((namesz == 8 && strcmp((char *)&nbuf[noff], "FreeBSD") == 0)) {
 644                 os_style = OS_STYLE_FREEBSD;
 645         }
 646
 647         if ((namesz >= 11 && strncmp((char *)&nbuf[noff], "NetBSD-CORE", 11)
 648             == 0)) {
 649                 os_style = OS_STYLE_NETBSD;
 650         }
 651
 652 #ifdef ELFCORE
 653         if ((*flags & FLAGS_DID_CORE) != 0)
 654                 return size;
 655
 656         if (os_style != -1 && (*flags & FLAGS_DID_CORE_STYLE) == 0) {
 657                 if (file_printf(ms, ", %s-style", os_style_names[os_style])
 658                     == -1)
 659                         return size;
 660                 *flags |= FLAGS_DID_CORE_STYLE;
 661         }
 662
 663         switch (os_style) {
 664         case OS_STYLE_NETBSD:
 665                 if (xnh_type == NT_NETBSD_CORE_PROCINFO) {
 666                         uint32_t signo;
 667                         /*
 668                          * Extract the program name.  It is at
 669                          * offset 0x7c, and is up to 32-bytes,
 670                          * including the terminating NUL.
 671                          */
 672                         if (file_printf(ms, ", from '%.31s'",
 673                             &nbuf[doff + 0x7c]) == -1)
 674                                 return size;
 675
 676                         /*
 677                          * Extract the signal number.  It is at
 678                          * offset 0x08.
 679                          */
 680                         (void)memcpy(&signo, &nbuf[doff + 0x08],
 681                             sizeof(signo));
 682                         if (file_printf(ms, " (signal %u)",
 683                             elf_getu32(swap, signo)) == -1)
 684                                 return size;
 685                         *flags |= FLAGS_DID_CORE;
 686                         return size;
 687                 }
 688                 break;
 689
 690         default:
 691                 if (xnh_type == NT_PRPSINFO) {
 692                         size_t i, j;
 693                         unsigned char c;
 694                         /*
 695                          * Extract the program name.  We assume
 696                          * it to be 16 characters (that's what it
 697                          * is in SunOS 5.x and Linux).
 698                          *
 699                          * Unfortunately, it's at a different offset
 700                          * in various OSes, so try multiple offsets.
 701                          * If the characters aren't all printable,
 702                          * reject it.
 703                          */
 704                         for (i = 0; i < NOFFSETS; i++) {
 705                                 unsigned char *cname, *cp;
 706                                 size_t reloffset = prpsoffsets(i);
 707                                 size_t noffset = doff + reloffset;
 708                                 for (j = 0; j < 16; j++, noffset++,
 709                                     reloffset++) {
 710                                         /*
 711                                          * Make sure we're not past
 712                                          * the end of the buffer; if
 713                                          * we are, just give up.
 714                                          */
 715                                         if (noffset >= size)
 716                                                 goto tryanother;
 717
 718                                         /*
 719                                          * Make sure we're not past
 720                                          * the end of the contents;
 721                                          * if we are, this obviously
 722                                          * isn't the right offset.
 723                                          */
 724                                         if (reloffset >= descsz)
 725                                                 goto tryanother;
 726
 727                                         c = nbuf[noffset];
 728                                         if (c == '\0') {
 729                                                 /*
 730                                                  * A '\0' at the
 731                                                  * beginning is
 732                                                  * obviously wrong.
 733                                                  * Any other '\0'
 734                                                  * means we're done.
 735                                                  */
 736                                                 if (j == 0)
 737                                                         goto tryanother;
 738                                                 else
 739                                                         break;
 740                                         } else {
 741                                                 /*
 742                                                  * A nonprintable
 743                                                  * character is also
 744                                                  * wrong.
 745                                                  */
 746                                                 if (!isprint(c) || isquote(c))
 747                                                         goto tryanother;
 748                                         }
 749                                 }
 750                                 /*
 751                                  * Well, that worked.
 752                                  */
 753                                 cname = (unsigned char *)
 754                                     &nbuf[doff + prpsoffsets(i)];
 755                                 for (cp = cname; *cp && isprint(*cp); cp++)
 756                                         continue;
 757                                 /*
 758                                  * Linux apparently appends a space at the end
 759                                  * of the command line: remove it.
 760                                  */
 761                                 while (cp > cname && isspace(cp[-1]))
 762                                         cp--;
 763                                 if (file_printf(ms, ", from '%.*s'",
 764                                     (int)(cp - cname), cname) == -1)
 765                                         return size;
 766                                 *flags |= FLAGS_DID_CORE;
 767                                 return size;
 768
 769                         tryanother:
 770                                 ;
 771                         }
 772                 }
 773                 break;
 774         }
 775 #endif
 776         return offset;
 777 }
 778
 779 /* SunOS 5.x hardware capability descriptions */
 780 typedef struct cap_desc {
 781         uint64_t cd_mask;
 782         const char *cd_name;
 783 } cap_desc_t;
 784
 785 static const cap_desc_t cap_desc_sparc[] = {
 786         { AV_SPARC_MUL32,               "MUL32" },
 787         { AV_SPARC_DIV32,               "DIV32" },
 788         { AV_SPARC_FSMULD,              "FSMULD" },
 789         { AV_SPARC_V8PLUS,              "V8PLUS" },
 790         { AV_SPARC_POPC,                "POPC" },
 791         { AV_SPARC_VIS,                 "VIS" },
 792         { AV_SPARC_VIS2,                "VIS2" },
 793         { AV_SPARC_ASI_BLK_INIT,        "ASI_BLK_INIT" },
 794         { AV_SPARC_FMAF,                "FMAF" },
 795         { AV_SPARC_FJFMAU,              "FJFMAU" },
 796         { AV_SPARC_IMA,                 "IMA" },
 797         { 0, NULL }
 798 };
 799
 800 static const cap_desc_t cap_desc_386[] = {
 801         { AV_386_FPU,                   "FPU" },
 802         { AV_386_TSC,                   "TSC" },
 803         { AV_386_CX8,                   "CX8" },
 804         { AV_386_SEP,                   "SEP" },
 805         { AV_386_AMD_SYSC,              "AMD_SYSC" },
 806         { AV_386_CMOV,                  "CMOV" },
 807         { AV_386_MMX,                   "MMX" },
 808         { AV_386_AMD_MMX,               "AMD_MMX" },
 809         { AV_386_AMD_3DNow,             "AMD_3DNow" },
 810         { AV_386_AMD_3DNowx,            "AMD_3DNowx" },
 811         { AV_386_FXSR,                  "FXSR" },
 812         { AV_386_SSE,                   "SSE" },
 813         { AV_386_SSE2,                  "SSE2" },
 814         { AV_386_PAUSE,                 "PAUSE" },
 815         { AV_386_SSE3,                  "SSE3" },
 816         { AV_386_MON,                   "MON" },
 817         { AV_386_CX16,                  "CX16" },
 818         { AV_386_AHF,                   "AHF" },
 819         { AV_386_TSCP,                  "TSCP" },
 820         { AV_386_AMD_SSE4A,             "AMD_SSE4A" },
 821         { AV_386_POPCNT,                "POPCNT" },
 822         { AV_386_AMD_LZCNT,             "AMD_LZCNT" },
 823         { AV_386_SSSE3,                 "SSSE3" },
 824         { AV_386_SSE4_1,                "SSE4.1" },
 825         { AV_386_SSE4_2,                "SSE4.2" },
 826         { 0, NULL }
 827 };
 828
 829 private int
 830 doshn(struct magic_set *ms, int clazz, int swap, int fd, off_t off, int num,
 831     size_t size, int *flags, int mach)
 832 {
 833         Elf32_Shdr sh32;
 834         Elf64_Shdr sh64;
 835         int stripped = 1;
 836         size_t nbadcap = 0;
 837         void *nbuf;
 838         off_t noff;
 839         uint64_t cap_hw1 = 0;   /* SunOS 5.x hardware capabilites */
 840         uint64_t cap_sf1 = 0;   /* SunOS 5.x software capabilites */
 841
 842         if (size != xsh_sizeof) {
 843                 if (file_printf(ms, ", corrupted section header size") == -1)
 844                         return -1;
 845                 return 0;
 846         }
 847
 848         if (lseek(fd, off, SEEK_SET) == (off_t)-1) {
 849                 file_badseek(ms);
 850                 return -1;
 851         }
 852
 853         for ( ; num; num--) {
 854                 if (read(fd, xsh_addr, xsh_sizeof) == -1) {
 855                         file_badread(ms);
 856                         return -1;
 857                 }
 858                 switch (xsh_type) {
 859                 case SHT_SYMTAB:
 860 #if 0
 861                 case SHT_DYNSYM:
 862 #endif
 863                         stripped = 0;
 864                         break;
 865                 case SHT_NOTE:
 866                         if ((off = lseek(fd, (off_t)0, SEEK_CUR)) ==
 867                             (off_t)-1) {
 868                                 file_badread(ms);
 869                                 return -1;
 870                         }
 871                         if ((nbuf = malloc((size_t)xsh_size)) == NULL) {
 872                                 file_error(ms, errno, "Cannot allocate memory"
 873                                     " for note");
 874                                 return -1;
 875                         }
 876                         if ((noff = lseek(fd, (off_t)xsh_offset, SEEK_SET)) ==
 877                             (off_t)-1) {
 878                                 file_badread(ms);
 879                                 free(nbuf);
 880                                 return -1;
 881                         }
 882                         if (read(fd, nbuf, (size_t)xsh_size) !=
 883                             (ssize_t)xsh_size) {
 884                                 free(nbuf);
 885                                 file_badread(ms);
 886                                 return -1;
 887                         }
 888
 889                         noff = 0;
 890                         for (;;) {
 891                                 if (noff >= (off_t)xsh_size)
 892                                         break;
 893                                 noff = donote(ms, nbuf, (size_t)noff,
 894                                     (size_t)xsh_size, clazz, swap, 4,
 895                                     flags);
 896                                 if (noff == 0)
 897                                         break;
 898                         }
 899                         if ((lseek(fd, off, SEEK_SET)) == (off_t)-1) {
 900                                 free(nbuf);
 901                                 file_badread(ms);
 902                                 return -1;
 903                         }
 904                         free(nbuf);
 905                         break;
 906                 case SHT_SUNW_cap:
 907                     {
 908                         off_t coff;
 909                         if (nbadcap > 5)
 910                                 break;
 911                         if ((off = lseek(fd, (off_t)0, SEEK_CUR)) ==
 912                             (off_t)-1) {
 913                                 file_badread(ms);
 914                                 return -1;
 915                         }
 916                         if (lseek(fd, (off_t)xsh_offset, SEEK_SET) ==
 917                             (off_t)-1) {
 918                                 file_badread(ms);
 919                                 return -1;
 920                         }
 921                         coff = 0;
 922                         for (;;) {
 923                                 Elf32_Cap cap32;
 924                                 Elf64_Cap cap64;
 925                                 char cbuf[/*CONSTCOND*/
 926                                     MAX(sizeof cap32, sizeof cap64)];
 927                                 if ((coff += xcap_sizeof) >= (off_t)xsh_size)
 928                                         break;
 929                                 if (read(fd, cbuf, (size_t)xcap_sizeof) !=
 930                                     (ssize_t)xcap_sizeof) {
 931                                         file_badread(ms);
 932                                         return -1;
 933                                 }
 934                                 (void)memcpy(xcap_addr, cbuf, xcap_sizeof);
 935                                 switch (xcap_tag) {
 936                                 case CA_SUNW_NULL:
 937                                         break;
 938                                 case CA_SUNW_HW_1:
 939                                         cap_hw1 |= xcap_val;
 940                                         break;
 941                                 case CA_SUNW_SF_1:
 942                                         cap_sf1 |= xcap_val;
 943                                         break;
 944                                 default:
 945                                         if (file_printf(ms,
 946                                             ", with unknown capability "
 947                                             "0x%llx = 0x%llx",
 948                                             (unsigned long long)xcap_tag,
 949                                             (unsigned long long)xcap_val) == -1)
 950                                                 return -1;
 951                                         if (nbadcap++ > 2)
 952                                                 coff = xsh_size;
 953                                         break;
 954                                 }
 955                         }
 956                         if (lseek(fd, off, SEEK_SET) == (off_t)-1) {
 957                                 file_badread(ms);
 958                                 return -1;
 959                         }
 960                         break;
 961                     }
 962                 }
 963         }
 964         if (file_printf(ms, ", %sstripped", stripped ? "" : "not ") == -1)
 965                 return -1;
 966         if (cap_hw1) {
 967                 const cap_desc_t *cdp;
 968                 switch (mach) {
 969                 case EM_SPARC:
 970                 case EM_SPARC32PLUS:
 971                 case EM_SPARCV9:
 972                         cdp = cap_desc_sparc;
 973                         break;
 974                 case EM_386:
 975                 case EM_IA_64:
 976                 case EM_AMD64:
 977                         cdp = cap_desc_386;
 978                         break;
 979                 default:
 980                         cdp = NULL;
 981                         break;
 982                 }
 983                 if (file_printf(ms, ", uses") == -1)
 984                         return -1;
 985                 if (cdp) {
 986                         while (cdp->cd_name) {
 987                                 if (cap_hw1 & cdp->cd_mask) {
 988                                         if (file_printf(ms,
 989                                             " %s", cdp->cd_name) == -1)
 990                                                 return -1;
 991                                         cap_hw1 &= ~cdp->cd_mask;
 992                                 }
 993                                 ++cdp;
 994                         }
 995                         if (cap_hw1)
 996                                 if (file_printf(ms,
 997                                     " unknown hardware capability 0x%llx",
 998                                     (unsigned long long)cap_hw1) == -1)
 999                                         return -1;
1000                 } else {
1001                         if (file_printf(ms,
1002                             " hardware capability 0x%llx",
1003                             (unsigned long long)cap_hw1) == -1)
1004                                 return -1;
1005                 }
1006         }
1007         if (cap_sf1) {
1008                 if (cap_sf1 & SF1_SUNW_FPUSED) {
1009                         if (file_printf(ms,
1010                             (cap_sf1 & SF1_SUNW_FPKNWN)
1011                             ? ", uses frame pointer"
1012                             : ", not known to use frame pointer") == -1)
1013                                 return -1;
1014                 }
1015                 cap_sf1 &= ~SF1_SUNW_MASK;
1016                 if (cap_sf1)
1017                         if (file_printf(ms,
1018                             ", with unknown software capability 0x%llx",
1019                             (unsigned long long)cap_sf1) == -1)
1020                                 return -1;
1021         }
1022         return 0;
1023 }
1024
1025 /*
1026  * Look through the program headers of an executable image, searching
1027  * for a PT_INTERP section; if one is found, it's dynamically linked,
1028  * otherwise it's statically linked.
1029  */
1030 private int
1031 dophn_exec(struct magic_set *ms, int clazz, int swap, int fd, off_t off,
1032     int num, size_t size, off_t fsize, int *flags, int sh_num)
1033 {
1034         Elf32_Phdr ph32;
1035         Elf64_Phdr ph64;
1036         const char *linking_style = "statically";
1037         const char *shared_libraries = "";
1038         unsigned char nbuf[BUFSIZ];
1039         int bufsize;
1040         size_t offset, align;
1041         off_t savedoffset = (off_t)-1;
1042         struct stat st;
1043
1044         if (fstat(fd, &st) < 0) {
1045                 file_badread(ms);
1046                 return -1;
1047         }
1048
1049         if (size != xph_sizeof) {
1050                 if (file_printf(ms, ", corrupted program header size") == -1)
1051                         return -1;
1052                 return 0;
1053         }
1054
1055         if (lseek(fd, off, SEEK_SET) == (off_t)-1) {
1056                 file_badseek(ms);
1057                 return -1;
1058         }
1059
1060         for ( ; num; num--) {
1061                 if (read(fd, xph_addr, xph_sizeof) == -1) {
1062                         file_badread(ms);
1063                         return -1;
1064                 }
1065                 if (xph_offset > st.st_size && savedoffset != (off_t)-1) {
1066                         if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
1067                                 file_badseek(ms);
1068                                 return -1;
1069                         }
1070                         continue;
1071                 }
1072
1073                 if ((savedoffset = lseek(fd, (off_t)0, SEEK_CUR)) == (off_t)-1) {
1074                         file_badseek(ms);
1075                         return -1;
1076                 }
1077
1078                 if (xph_offset > fsize) {
1079                         if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
1080                                 file_badseek(ms);
1081                                 return -1;
1082                         }
1083                         continue;
1084                 }
1085
1086                 switch (xph_type) {
1087                 case PT_DYNAMIC:
1088                         linking_style = "dynamically";
1089                         break;
1090                 case PT_INTERP:
1091                         shared_libraries = " (uses shared libs)";
1092                         break;
1093                 case PT_NOTE:
1094                         if ((align = xph_align) & 0x80000000) {
1095                                 if (file_printf(ms,
1096                                     ", invalid note alignment 0x%lx",
1097                                     (unsigned long)align) == -1)
1098                                         return -1;
1099                                 align = 4;
1100                         }
1101                         if (sh_num)
1102                                 break;
1103                         /*
1104                          * This is a PT_NOTE section; loop through all the notes
1105                          * in the section.
1106                          */
1107                         if (lseek(fd, xph_offset, SEEK_SET)
1108                             == (off_t)-1) {
1109                                 file_badseek(ms);
1110                                 return -1;
1111                         }
1112                         bufsize = read(fd, nbuf, ((xph_filesz < sizeof(nbuf)) ?
1113                             xph_filesz : sizeof(nbuf)));
1114                         if (bufsize == -1) {
1115                                 file_badread(ms);
1116                                 return -1;
1117                         }
1118                         offset = 0;
1119                         for (;;) {
1120                                 if (offset >= (size_t)bufsize)
1121                                         break;
1122                                 offset = donote(ms, nbuf, offset,
1123                                     (size_t)bufsize, clazz, swap, align,
1124                                     flags);
1125                                 if (offset == 0)
1126                                         break;
1127                         }
1128                         if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
1129                                 file_badseek(ms);
1130                                 return -1;
1131                         }
1132                         break;
1133                 default:
1134                         break;
1135                 }
1136         }
1137         if (file_printf(ms, ", %s linked%s", linking_style, shared_libraries)
1138             == -1)
1139             return -1;
1140         return 0;
1141 }
1142
1143
1144 protected int
1145 file_tryelf(struct magic_set *ms, int fd, const unsigned char *buf,
1146     size_t nbytes)
1147 {
1148         union {
1149                 int32_t l;
1150                 char c[sizeof (int32_t)];
1151         } u;
1152         int clazz;
1153         int swap;
1154         struct stat st;
1155         off_t fsize;
1156         int flags = 0;
1157         Elf32_Ehdr elf32hdr;
1158         Elf64_Ehdr elf64hdr;
1159         uint16_t type, phnum, shnum;
1160
1161         if (ms->flags & (MAGIC_MIME|MAGIC_APPLE))
1162                 return 0;
1163         /*
1164          * ELF executables have multiple section headers in arbitrary
1165          * file locations and thus file(1) cannot determine it from easily.
1166          * Instead we traverse thru all section headers until a symbol table
1167          * one is found or else the binary is stripped.
1168          * Return immediately if it's not ELF (so we avoid pipe2file unless needed).
1169          */
1170         if (buf[EI_MAG0] != ELFMAG0
1171             || (buf[EI_MAG1] != ELFMAG1 && buf[EI_MAG1] != OLFMAG1)
1172             || buf[EI_MAG2] != ELFMAG2 || buf[EI_MAG3] != ELFMAG3)
1173                 return 0;
1174
1175         /*
1176          * If we cannot seek, it must be a pipe, socket or fifo.
1177          */
1178         if((lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) && (errno == ESPIPE))
1179                 fd = file_pipe2file(ms, fd, buf, nbytes);
1180
1181         if (fstat(fd, &st) == -1) {
1182                 file_badread(ms);
1183                 return -1;
1184         }
1185         fsize = st.st_size;
1186
1187         clazz = buf[EI_CLASS];
1188
1189         switch (clazz) {
1190         case ELFCLASS32:
1191 #undef elf_getu
1192 #define elf_getu(a, b)  elf_getu32(a, b)
1193 #undef elfhdr
1194 #define elfhdr elf32hdr
1195 #include "elfclass.h"
1196         case ELFCLASS64:
1197 #undef elf_getu
1198 #define elf_getu(a, b)  elf_getu64(a, b)
1199 #undef elfhdr
1200 #define elfhdr elf64hdr
1201 #include "elfclass.h"
1202         default:
1203             if (file_printf(ms, ", unknown class %d", clazz) == -1)
1204                     return -1;
1205             break;
1206         }
1207         return 0;
1208 }
1209 #endif