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 #ifdef BUILTIN_ELF
  30 #include <string.h>
  31 #include <ctype.h>
  32 #include <stdlib.h>
  33 #ifdef HAVE_UNISTD_H
  34 #include <unistd.h>
  35 #endif
  36
  37 #include "readelf.h"
  38 #include "magic.h"
  39
  40 #ifndef lint
  41 FILE_RCSID("@(#)$File: readelf.c,v 1.76 2008/07/16 18:00:57 christos Exp $")
  42 #endif
  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 private uint16_t
  64 getu16(int swap, uint16_t value)
  65 {
  66         union {
  67                 uint16_t ui;
  68                 char c[2];
  69         } retval, tmpval;
  70
  71         if (swap) {
  72                 tmpval.ui = value;
  73
  74                 retval.c[0] = tmpval.c[1];
  75                 retval.c[1] = tmpval.c[0];
  76
  77                 return retval.ui;
  78         } else
  79                 return value;
  80 }
  81
  82 private uint32_t
  83 getu32(int swap, uint32_t value)
  84 {
  85         union {
  86                 uint32_t ui;
  87                 char c[4];
  88         } retval, tmpval;
  89
  90         if (swap) {
  91                 tmpval.ui = value;
  92
  93                 retval.c[0] = tmpval.c[3];
  94                 retval.c[1] = tmpval.c[2];
  95                 retval.c[2] = tmpval.c[1];
  96                 retval.c[3] = tmpval.c[0];
  97
  98                 return retval.ui;
  99         } else
 100                 return value;
 101 }
 102
 103 private uint64_t
 104 getu64(int swap, uint64_t value)
 105 {
 106         union {
 107                 uint64_t ui;
 108                 char c[8];
 109         } retval, tmpval;
 110
 111         if (swap) {
 112                 tmpval.ui = value;
 113
 114                 retval.c[0] = tmpval.c[7];
 115                 retval.c[1] = tmpval.c[6];
 116                 retval.c[2] = tmpval.c[5];
 117                 retval.c[3] = tmpval.c[4];
 118                 retval.c[4] = tmpval.c[3];
 119                 retval.c[5] = tmpval.c[2];
 120                 retval.c[6] = tmpval.c[1];
 121                 retval.c[7] = tmpval.c[0];
 122
 123                 return retval.ui;
 124         } else
 125                 return value;
 126 }
 127
 128 #define elf_getu16(swap, value) getu16(swap, value)
 129 #define elf_getu32(swap, value) getu32(swap, value)
 130 #ifdef USE_ARRAY_FOR_64BIT_TYPES
 131 # define elf_getu64(swap, array) \
 132         ((swap ? ((uint64_t)elf_getu32(swap, array[0])) << 32 : elf_getu32(swap, array[0])) + \
 133          (swap ? elf_getu32(swap, array[1]) : ((uint64_t)elf_getu32(swap, array[1]) << 32)))
 134 #else
 135 # define elf_getu64(swap, value) getu64(swap, value)
 136 #endif
 137
 138 #define xsh_addr        (clazz == ELFCLASS32                    \
 139                          ? (void *) &sh32                       \
 140                          : (void *) &sh64)
 141 #define xsh_sizeof      (clazz == ELFCLASS32                    \
 142                          ? sizeof sh32                          \
 143                          : sizeof sh64)
 144 #define xsh_size        (clazz == ELFCLASS32                    \
 145                          ? elf_getu32(swap, sh32.sh_size)       \
 146                          : elf_getu64(swap, sh64.sh_size))
 147 #define xsh_offset      (clazz == ELFCLASS32                    \
 148                          ? elf_getu32(swap, sh32.sh_offset)     \
 149                          : elf_getu64(swap, sh64.sh_offset))
 150 #define xsh_type        (clazz == ELFCLASS32                    \
 151                          ? elf_getu32(swap, sh32.sh_type)       \
 152                          : elf_getu32(swap, sh64.sh_type))
 153 #define xph_addr        (clazz == ELFCLASS32                    \
 154                          ? (void *) &ph32                       \
 155                          : (void *) &ph64)
 156 #define xph_sizeof      (clazz == ELFCLASS32                    \
 157                          ? sizeof ph32                          \
 158                          : sizeof ph64)
 159 #define xph_type        (clazz == ELFCLASS32                    \
 160                          ? elf_getu32(swap, ph32.p_type)        \
 161                          : elf_getu32(swap, ph64.p_type))
 162 #define xph_offset      (off_t)(clazz == ELFCLASS32             \
 163                          ? elf_getu32(swap, ph32.p_offset)      \
 164                          : elf_getu64(swap, ph64.p_offset))
 165 #define xph_align       (size_t)((clazz == ELFCLASS32           \
 166                          ? (off_t) (ph32.p_align ?              \
 167                             elf_getu32(swap, ph32.p_align) : 4) \
 168                          : (off_t) (ph64.p_align ?              \
 169                             elf_getu64(swap, ph64.p_align) : 4)))
 170 #define xph_filesz      (size_t)((clazz == ELFCLASS32           \
 171                          ? elf_getu32(swap, ph32.p_filesz)      \
 172                          : elf_getu64(swap, ph64.p_filesz)))
 173 #define xnh_addr        (clazz == ELFCLASS32                    \
 174                          ? (void *) &nh32                       \
 175                          : (void *) &nh64)
 176 #define xph_memsz       (size_t)((clazz == ELFCLASS32           \
 177                          ? elf_getu32(swap, ph32.p_memsz)       \
 178                          : elf_getu64(swap, ph64.p_memsz)))
 179 #define xnh_sizeof      (clazz == ELFCLASS32                    \
 180                          ? sizeof nh32                          \
 181                          : sizeof nh64)
 182 #define xnh_type        (clazz == ELFCLASS32                    \
 183                          ? elf_getu32(swap, nh32.n_type)        \
 184                          : elf_getu32(swap, nh64.n_type))
 185 #define xnh_namesz      (clazz == ELFCLASS32                    \
 186                          ? elf_getu32(swap, nh32.n_namesz)      \
 187                          : elf_getu32(swap, nh64.n_namesz))
 188 #define xnh_descsz      (clazz == ELFCLASS32                    \
 189                          ? elf_getu32(swap, nh32.n_descsz)      \
 190                          : elf_getu32(swap, nh64.n_descsz))
 191 #define prpsoffsets(i)  (clazz == ELFCLASS32                    \
 192                          ? prpsoffsets32[i]                     \
 193                          : prpsoffsets64[i])
 194 #define xcap_addr       (clazz == ELFCLASS32                    \
 195                          ? (void *) &cap32                      \
 196                          : (void *) &cap64)
 197 #define xcap_sizeof     (clazz == ELFCLASS32                    \
 198                          ? sizeof cap32                         \
 199                          : sizeof cap64)
 200 #define xcap_tag        (clazz == ELFCLASS32                    \
 201                          ? elf_getu32(swap, cap32.c_tag)        \
 202                          : elf_getu64(swap, cap64.c_tag))
 203 #define xcap_val        (clazz == ELFCLASS32                    \
 204                          ? elf_getu32(swap, cap32.c_un.c_val)   \
 205                          : elf_getu64(swap, cap64.c_un.c_val))
 206
 207 #ifdef ELFCORE
 208 /*
 209  * Try larger offsets first to avoid false matches
 210  * from earlier data that happen to look like strings.
 211  */
 212 static const size_t     prpsoffsets32[] = {
 213 #ifdef USE_NT_PSINFO
 214         104,            /* SunOS 5.x (command line) */
 215         88,             /* SunOS 5.x (short name) */
 216 #endif /* USE_NT_PSINFO */
 217
 218         100,            /* SunOS 5.x (command line) */
 219         84,             /* SunOS 5.x (short name) */
 220
 221         44,             /* Linux (command line) */
 222         28,             /* Linux 2.0.36 (short name) */
 223
 224         8,              /* FreeBSD */
 225 };
 226
 227 static const size_t     prpsoffsets64[] = {
 228 #ifdef USE_NT_PSINFO
 229         152,            /* SunOS 5.x (command line) */
 230         136,            /* SunOS 5.x (short name) */
 231 #endif /* USE_NT_PSINFO */
 232
 233         136,            /* SunOS 5.x, 64-bit (command line) */
 234         120,            /* SunOS 5.x, 64-bit (short name) */
 235
 236         56,             /* Linux (command line) */
 237         40,             /* Linux (tested on core from 2.4.x, short name) */
 238
 239         16,             /* FreeBSD, 64-bit */
 240 };
 241
 242 #define NOFFSETS32      (sizeof prpsoffsets32 / sizeof prpsoffsets32[0])
 243 #define NOFFSETS64      (sizeof prpsoffsets64 / sizeof prpsoffsets64[0])
 244
 245 #define NOFFSETS        (clazz == ELFCLASS32 ? NOFFSETS32 : NOFFSETS64)
 246
 247 /*
 248  * Look through the program headers of an executable image, searching
 249  * for a PT_NOTE section of type NT_PRPSINFO, with a name "CORE" or
 250  * "FreeBSD"; if one is found, try looking in various places in its
 251  * contents for a 16-character string containing only printable
 252  * characters - if found, that string should be the name of the program
 253  * that dropped core.  Note: right after that 16-character string is,
 254  * at least in SunOS 5.x (and possibly other SVR4-flavored systems) and
 255  * Linux, a longer string (80 characters, in 5.x, probably other
 256  * SVR4-flavored systems, and Linux) containing the start of the
 257  * command line for that program.
 258  *
 259  * SunOS 5.x core files contain two PT_NOTE sections, with the types
 260  * NT_PRPSINFO (old) and NT_PSINFO (new).  These structs contain the
 261  * same info about the command name and command line, so it probably
 262  * isn't worthwhile to look for NT_PSINFO, but the offsets are provided
 263  * above (see USE_NT_PSINFO), in case we ever decide to do so.  The
 264  * NT_PRPSINFO and NT_PSINFO sections are always in order and adjacent;
 265  * the SunOS 5.x file command relies on this (and prefers the latter).
 266  *
 267  * The signal number probably appears in a section of type NT_PRSTATUS,
 268  * but that's also rather OS-dependent, in ways that are harder to
 269  * dissect with heuristics, so I'm not bothering with the signal number.
 270  * (I suppose the signal number could be of interest in situations where
 271  * you don't have the binary of the program that dropped core; if you
 272  * *do* have that binary, the debugger will probably tell you what
 273  * signal it was.)
 274  */
 275
 276 #define OS_STYLE_SVR4           0
 277 #define OS_STYLE_FREEBSD        1
 278 #define OS_STYLE_NETBSD         2
 279
 280 private const char os_style_names[][8] = {
 281         "SVR4",
 282         "FreeBSD",
 283         "NetBSD",
 284 };
 285
 286 #define FLAGS_DID_CORE          1
 287 #define FLAGS_DID_NOTE          2
 288 #define FLAGS_DID_CORE_STYLE    4
 289
 290 private int
 291 dophn_core(struct magic_set *ms, int clazz, int swap, int fd, off_t off,
 292     int num, size_t size, off_t fsize, int *flags)
 293 {
 294         Elf32_Phdr ph32;
 295         Elf64_Phdr ph64;
 296         size_t offset;
 297         unsigned char nbuf[BUFSIZ];
 298         ssize_t bufsize;
 299         off_t savedoffset;
 300         struct stat st;
 301
 302         if (fstat(fd, &st) < 0) {
 303                 file_badread(ms);
 304                 return -1;
 305         }
 306
 307         if (size != xph_sizeof) {
 308                 if (file_printf(ms, ", corrupted program header size") == -1)
 309                         return -1;
 310                 return 0;
 311         }
 312
 313         /*
 314          * Loop through all the program headers.
 315          */
 316         for ( ; num; num--) {
 317                 if ((savedoffset = lseek(fd, off, SEEK_SET)) == (off_t)-1) {
 318                         file_badseek(ms);
 319                         return -1;
 320                 }
 321                 if (read(fd, xph_addr, xph_sizeof) == -1) {
 322                         file_badread(ms);
 323                         return -1;
 324                 }
 325                 if (xph_offset > fsize) {
 326                         if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
 327                                 file_badseek(ms);
 328                                 return -1;
 329                         }
 330                         continue;
 331                 }
 332
 333                 off += size;
 334                 if (xph_type != PT_NOTE)
 335                         continue;
 336
 337                 /*
 338                  * This is a PT_NOTE section; loop through all the notes
 339                  * in the section.
 340                  */
 341                 if (lseek(fd, xph_offset, SEEK_SET) == (off_t)-1) {
 342                         file_badseek(ms);
 343                         return -1;
 344                 }
 345                 bufsize = read(fd, nbuf,
 346                     ((xph_filesz < sizeof(nbuf)) ? xph_filesz : sizeof(nbuf)));
 347                 if (bufsize == -1) {
 348                         file_badread(ms);
 349                         return -1;
 350                 }
 351                 offset = 0;
 352                 for (;;) {
 353                         if (offset >= (size_t)bufsize)
 354                                 break;
 355                         offset = donote(ms, nbuf, offset, (size_t)bufsize,
 356                             clazz, swap, 4, flags);
 357                         if (offset == 0)
 358                                 break;
 359
 360                 }
 361         }
 362         return 0;
 363 }
 364 #endif
 365
 366 private size_t
 367 donote(struct magic_set *ms, void *vbuf, size_t offset, size_t size,
 368     int clazz, int swap, size_t align, int *flags)
 369 {
 370         Elf32_Nhdr nh32;
 371         Elf64_Nhdr nh64;
 372         size_t noff, doff;
 373 #ifdef ELFCORE
 374         int os_style = -1;
 375 #endif
 376         uint32_t namesz, descsz;
 377         unsigned char *nbuf = CAST(unsigned char *, vbuf);
 378
 379         (void)memcpy(xnh_addr, &nbuf[offset], xnh_sizeof);
 380         offset += xnh_sizeof;
 381
 382         namesz = xnh_namesz;
 383         descsz = xnh_descsz;
 384         if ((namesz == 0) && (descsz == 0)) {
 385                 /*
 386                  * We're out of note headers.
 387                  */
 388                 return (offset >= size) ? offset : size;
 389         }
 390
 391         if (namesz & 0x80000000) {
 392             (void)file_printf(ms, ", bad note name size 0x%lx",
 393                 (unsigned long)namesz);
 394             return offset;
 395         }
 396
 397         if (descsz & 0x80000000) {
 398             (void)file_printf(ms, ", bad note description size 0x%lx",
 399                 (unsigned long)descsz);
 400             return offset;
 401         }
 402
 403
 404         noff = offset;
 405         doff = ELF_ALIGN(offset + namesz);
 406
 407         if (offset + namesz > size) {
 408                 /*
 409                  * We're past the end of the buffer.
 410                  */
 411                 return doff;
 412         }
 413
 414         offset = ELF_ALIGN(doff + descsz);
 415         if (doff + descsz > size) {
 416                 /*
 417                  * We're past the end of the buffer.
 418                  */
 419                 return (offset >= size) ? offset : size;
 420         }
 421
 422         if (*flags & FLAGS_DID_NOTE)
 423                 goto core;
 424
 425         if (namesz == 4 && strcmp((char *)&nbuf[noff], "GNU") == 0 &&
 426             xnh_type == NT_GNU_VERSION && descsz == 16) {
 427                 uint32_t desc[4];
 428                 (void)memcpy(desc, &nbuf[doff], sizeof(desc));
 429
 430                 if (file_printf(ms, ", for GNU/") == -1)
 431                         return size;
 432                 switch (elf_getu32(swap, desc[0])) {
 433                 case GNU_OS_LINUX:
 434                         if (file_printf(ms, "Linux") == -1)
 435                                 return size;
 436                         break;
 437                 case GNU_OS_HURD:
 438                         if (file_printf(ms, "Hurd") == -1)
 439                                 return size;
 440                         break;
 441                 case GNU_OS_SOLARIS:
 442                         if (file_printf(ms, "Solaris") == -1)
 443                                 return size;
 444                         break;
 445                 case GNU_OS_KFREEBSD:
 446                         if (file_printf(ms, "kFreeBSD") == -1)
 447                                 return size;
 448                         break;
 449                 case GNU_OS_KNETBSD:
 450                         if (file_printf(ms, "kNetBSD") == -1)
 451                                 return size;
 452                         break;
 453                 default:
 454                         if (file_printf(ms, "<unknown>") == -1)
 455                                 return size;
 456                 }
 457                 if (file_printf(ms, " %d.%d.%d", elf_getu32(swap, desc[1]),
 458                     elf_getu32(swap, desc[2]), elf_getu32(swap, desc[3])) == -1)
 459                         return size;
 460                 *flags |= FLAGS_DID_NOTE;
 461                 return size;
 462         }
 463
 464         if (namesz == 7 && strcmp((char *)&nbuf[noff], "NetBSD") == 0 &&
 465             xnh_type == NT_NETBSD_VERSION && descsz == 4) {
 466                 uint32_t desc;
 467                 (void)memcpy(&desc, &nbuf[doff], sizeof(desc));
 468                 desc = elf_getu32(swap, desc);
 469
 470                 if (file_printf(ms, ", for NetBSD") == -1)
 471                         return size;
 472                 /*
 473                  * The version number used to be stuck as 199905, and was thus
 474                  * basically content-free.  Newer versions of NetBSD have fixed
 475                  * this and now use the encoding of __NetBSD_Version__:
 476                  *
 477                  *      MMmmrrpp00
 478                  *
 479                  * M = major version
 480                  * m = minor version
 481                  * r = release ["",A-Z,Z[A-Z] but numeric]
 482                  * p = patchlevel
 483                  */
 484                 if (desc > 100000000U) {
 485                         uint32_t ver_patch = (desc / 100) % 100;
 486                         uint32_t ver_rel = (desc / 10000) % 100;
 487                         uint32_t ver_min = (desc / 1000000) % 100;
 488                         uint32_t ver_maj = desc / 100000000;
 489
 490                         if (file_printf(ms, " %u.%u", ver_maj, ver_min) == -1)
 491                                 return size;
 492                         if (ver_rel == 0 && ver_patch != 0) {
 493                                 if (file_printf(ms, ".%u", ver_patch) == -1)
 494                                         return size;
 495                         } else if (ver_rel != 0) {
 496                                 while (ver_rel > 26) {
 497                                         if (file_printf(ms, "Z") == -1)
 498                                                 return size;
 499                                         ver_rel -= 26;
 500                                 }
 501                                 if (file_printf(ms, "%c", 'A' + ver_rel - 1)
 502                                     == -1)
 503                                         return size;
 504                         }
 505                 }
 506                 *flags |= FLAGS_DID_NOTE;
 507                 return size;
 508         }
 509
 510         if (namesz == 8 && strcmp((char *)&nbuf[noff], "FreeBSD") == 0 &&
 511             xnh_type == NT_FREEBSD_VERSION && descsz == 4) {
 512                 uint32_t desc;
 513                 (void)memcpy(&desc, &nbuf[doff], sizeof(desc));
 514                 desc = elf_getu32(swap, desc);
 515                 if (file_printf(ms, ", for FreeBSD") == -1)
 516                         return size;
 517
 518                 /*
 519                  * Contents is __FreeBSD_version, whose relation to OS
 520                  * versions is defined by a huge table in the Porter's
 521                  * Handbook.  This is the general scheme:
 522                  *
 523                  * Releases:
 524                  *      Mmp000 (before 4.10)
 525                  *      Mmi0p0 (before 5.0)
 526                  *      Mmm0p0
 527                  *
 528                  * Development branches:
 529                  *      Mmpxxx (before 4.6)
 530                  *      Mmp1xx (before 4.10)
 531                  *      Mmi1xx (before 5.0)
 532                  *      M000xx (pre-M.0)
 533                  *      Mmm1xx
 534                  *
 535                  * M = major version
 536                  * m = minor version
 537                  * i = minor version increment (491000 -> 4.10)
 538                  * p = patchlevel
 539                  * x = revision
 540                  *
 541                  * The first release of FreeBSD to use ELF by default
 542                  * was version 3.0.
 543                  */
 544                 if (desc == 460002) {
 545                         if (file_printf(ms, " 4.6.2") == -1)
 546                                 return size;
 547                 } else if (desc < 460100) {
 548                         if (file_printf(ms, " %d.%d", desc / 100000,
 549                             desc / 10000 % 10) == -1)
 550                                 return size;
 551                         if (desc / 1000 % 10 > 0)
 552                                 if (file_printf(ms, ".%d", desc / 1000 % 10)
 553                                     == -1)
 554                                         return size;
 555                         if ((desc % 1000 > 0) || (desc % 100000 == 0))
 556                                 if (file_printf(ms, " (%d)", desc) == -1)
 557                                         return size;
 558                 } else if (desc < 500000) {
 559                         if (file_printf(ms, " %d.%d", desc / 100000,
 560                             desc / 10000 % 10 + desc / 1000 % 10) == -1)
 561                                 return size;
 562                         if (desc / 100 % 10 > 0) {
 563                                 if (file_printf(ms, " (%d)", desc) == -1)
 564                                         return size;
 565                         } else if (desc / 10 % 10 > 0) {
 566                                 if (file_printf(ms, ".%d", desc / 10 % 10)
 567                                     == -1)
 568                                         return size;
 569                         }
 570                 } else {
 571                         if (file_printf(ms, " %d.%d", desc / 100000,
 572                             desc / 1000 % 100) == -1)
 573                                 return size;
 574                         if ((desc / 100 % 10 > 0) ||
 575                             (desc % 100000 / 100 == 0)) {
 576                                 if (file_printf(ms, " (%d)", desc) == -1)
 577                                         return size;
 578                         } else if (desc / 10 % 10 > 0) {
 579                                 if (file_printf(ms, ".%d", desc / 10 % 10)
 580                                     == -1)
 581                                         return size;
 582                         }
 583                 }
 584                 *flags |= FLAGS_DID_NOTE;
 585                 return size;
 586         }
 587
 588         if (namesz == 8 && strcmp((char *)&nbuf[noff], "OpenBSD") == 0 &&
 589             xnh_type == NT_OPENBSD_VERSION && descsz == 4) {
 590                 if (file_printf(ms, ", for OpenBSD") == -1)
 591                         return size;
 592                 /* Content of note is always 0 */
 593                 *flags |= FLAGS_DID_NOTE;
 594                 return size;
 595         }
 596
 597         if (namesz == 10 && strcmp((char *)&nbuf[noff], "DragonFly") == 0 &&
 598             xnh_type == NT_DRAGONFLY_VERSION && descsz == 4) {
 599                 uint32_t desc;
 600                 if (file_printf(ms, ", for DragonFly") == -1)
 601                         return size;
 602                 (void)memcpy(&desc, &nbuf[doff], sizeof(desc));
 603                 desc = elf_getu32(swap, desc);
 604                 if (file_printf(ms, " %d.%d.%d", desc / 100000,
 605                     desc / 10000 % 10, desc % 10000) == -1)
 606                         return size;
 607                 *flags |= FLAGS_DID_NOTE;
 608                 return size;
 609         }
 610
 611 core:
 612         /*
 613          * Sigh.  The 2.0.36 kernel in Debian 2.1, at
 614          * least, doesn't correctly implement name
 615          * sections, in core dumps, as specified by
 616          * the "Program Linking" section of "UNIX(R) System
 617          * V Release 4 Programmer's Guide: ANSI C and
 618          * Programming Support Tools", because my copy
 619          * clearly says "The first 'namesz' bytes in 'name'
 620          * contain a *null-terminated* [emphasis mine]
 621          * character representation of the entry's owner
 622          * or originator", but the 2.0.36 kernel code
 623          * doesn't include the terminating null in the
 624          * name....
 625          */
 626         if ((namesz == 4 && strncmp((char *)&nbuf[noff], "CORE", 4) == 0) ||
 627             (namesz == 5 && strcmp((char *)&nbuf[noff], "CORE") == 0)) {
 628                 os_style = OS_STYLE_SVR4;
 629         }
 630
 631         if ((namesz == 8 && strcmp((char *)&nbuf[noff], "FreeBSD") == 0)) {
 632                 os_style = OS_STYLE_FREEBSD;
 633         }
 634
 635         if ((namesz >= 11 && strncmp((char *)&nbuf[noff], "NetBSD-CORE", 11)
 636             == 0)) {
 637                 os_style = OS_STYLE_NETBSD;
 638         }
 639
 640 #ifdef ELFCORE
 641         if ((*flags & FLAGS_DID_CORE) != 0)
 642                 return size;
 643
 644         if (os_style != -1 && (*flags & FLAGS_DID_CORE_STYLE) == 0) {
 645                 if (file_printf(ms, ", %s-style", os_style_names[os_style])
 646                     == -1)
 647                         return size;
 648                 *flags |= FLAGS_DID_CORE_STYLE;
 649         }
 650
 651         switch (os_style) {
 652         case OS_STYLE_NETBSD:
 653                 if (xnh_type == NT_NETBSD_CORE_PROCINFO) {
 654                         uint32_t signo;
 655                         /*
 656                          * Extract the program name.  It is at
 657                          * offset 0x7c, and is up to 32-bytes,
 658                          * including the terminating NUL.
 659                          */
 660                         if (file_printf(ms, ", from '%.31s'",
 661                             &nbuf[doff + 0x7c]) == -1)
 662                                 return size;
 663
 664                         /*
 665                          * Extract the signal number.  It is at
 666                          * offset 0x08.
 667                          */
 668                         (void)memcpy(&signo, &nbuf[doff + 0x08],
 669                             sizeof(signo));
 670                         if (file_printf(ms, " (signal %u)",
 671                             elf_getu32(swap, signo)) == -1)
 672                                 return size;
 673                         *flags |= FLAGS_DID_CORE;
 674                         return size;
 675                 }
 676                 break;
 677
 678         default:
 679                 if (xnh_type == NT_PRPSINFO) {
 680                         size_t i, j;
 681                         unsigned char c;
 682                         /*
 683                          * Extract the program name.  We assume
 684                          * it to be 16 characters (that's what it
 685                          * is in SunOS 5.x and Linux).
 686                          *
 687                          * Unfortunately, it's at a different offset
 688                          * in various OSes, so try multiple offsets.
 689                          * If the characters aren't all printable,
 690                          * reject it.
 691                          */
 692                         for (i = 0; i < NOFFSETS; i++) {
 693                                 unsigned char *cname, *cp;
 694                                 size_t reloffset = prpsoffsets(i);
 695                                 size_t noffset = doff + reloffset;
 696                                 for (j = 0; j < 16; j++, noffset++,
 697                                     reloffset++) {
 698                                         /*
 699                                          * Make sure we're not past
 700                                          * the end of the buffer; if
 701                                          * we are, just give up.
 702                                          */
 703                                         if (noffset >= size)
 704                                                 goto tryanother;
 705
 706                                         /*
 707                                          * Make sure we're not past
 708                                          * the end of the contents;
 709                                          * if we are, this obviously
 710                                          * isn't the right offset.
 711                                          */
 712                                         if (reloffset >= descsz)
 713                                                 goto tryanother;
 714
 715                                         c = nbuf[noffset];
 716                                         if (c == '\0') {
 717                                                 /*
 718                                                  * A '\0' at the
 719                                                  * beginning is
 720                                                  * obviously wrong.
 721                                                  * Any other '\0'
 722                                                  * means we're done.
 723                                                  */
 724                                                 if (j == 0)
 725                                                         goto tryanother;
 726                                                 else
 727                                                         break;
 728                                         } else {
 729                                                 /*
 730                                                  * A nonprintable
 731                                                  * character is also
 732                                                  * wrong.
 733                                                  */
 734                                                 if (!isprint(c) || isquote(c))
 735                                                         goto tryanother;
 736                                         }
 737                                 }
 738                                 /*
 739                                  * Well, that worked.
 740                                  */
 741                                 cname = (unsigned char *)
 742                                     &nbuf[doff + prpsoffsets(i)];
 743                                 for (cp = cname; *cp && isprint(*cp); cp++)
 744                                         continue;
 745                                 /*
 746                                  * Linux apparently appends a space at the end
 747                                  * of the command line: remove it.
 748                                  */
 749                                 while (cp > cname && isspace(cp[-1]))
 750                                         cp--;
 751                                 if (file_printf(ms, ", from '%.*s'",
 752                                     (int)(cp - cname), cname) == -1)
 753                                         return size;
 754                                 *flags |= FLAGS_DID_CORE;
 755                                 return size;
 756
 757                         tryanother:
 758                                 ;
 759                         }
 760                 }
 761                 break;
 762         }
 763 #endif
 764         return offset;
 765 }
 766
 767 /* SunOS 5.x hardware capability descriptions */
 768 typedef struct cap_desc {
 769         uint64_t cd_mask;
 770         const char *cd_name;
 771 } cap_desc_t;
 772
 773 static const cap_desc_t cap_desc_sparc[] = {
 774         { AV_SPARC_MUL32,               "MUL32" },
 775         { AV_SPARC_DIV32,               "DIV32" },
 776         { AV_SPARC_FSMULD,              "FSMULD" },
 777         { AV_SPARC_V8PLUS,              "V8PLUS" },
 778         { AV_SPARC_POPC,                "POPC" },
 779         { AV_SPARC_VIS,                 "VIS" },
 780         { AV_SPARC_VIS2,                "VIS2" },
 781         { AV_SPARC_ASI_BLK_INIT,        "ASI_BLK_INIT" },
 782         { AV_SPARC_FMAF,                "FMAF" },
 783         { AV_SPARC_FJFMAU,              "FJFMAU" },
 784         { AV_SPARC_IMA,                 "IMA" },
 785         { 0, NULL }
 786 };
 787
 788 static const cap_desc_t cap_desc_386[] = {
 789         { AV_386_FPU,                   "FPU" },
 790         { AV_386_TSC,                   "TSC" },
 791         { AV_386_CX8,                   "CX8" },
 792         { AV_386_SEP,                   "SEP" },
 793         { AV_386_AMD_SYSC,              "AMD_SYSC" },
 794         { AV_386_CMOV,                  "CMOV" },
 795         { AV_386_MMX,                   "MMX" },
 796         { AV_386_AMD_MMX,               "AMD_MMX" },
 797         { AV_386_AMD_3DNow,             "AMD_3DNow" },
 798         { AV_386_AMD_3DNowx,            "AMD_3DNowx" },
 799         { AV_386_FXSR,                  "FXSR" },
 800         { AV_386_SSE,                   "SSE" },
 801         { AV_386_SSE2,                  "SSE2" },
 802         { AV_386_PAUSE,                 "PAUSE" },
 803         { AV_386_SSE3,                  "SSE3" },
 804         { AV_386_MON,                   "MON" },
 805         { AV_386_CX16,                  "CX16" },
 806         { AV_386_AHF,                   "AHF" },
 807         { AV_386_TSCP,                  "TSCP" },
 808         { AV_386_AMD_SSE4A,             "AMD_SSE4A" },
 809         { AV_386_POPCNT,                "POPCNT" },
 810         { AV_386_AMD_LZCNT,             "AMD_LZCNT" },
 811         { AV_386_SSSE3,                 "SSSE3" },
 812         { AV_386_SSE4_1,                "SSE4.1" },
 813         { AV_386_SSE4_2,                "SSE4.2" },
 814         { 0, NULL }
 815 };
 816
 817 private int
 818 doshn(struct magic_set *ms, int clazz, int swap, int fd, off_t off, int num,
 819     size_t size, int *flags, int mach)
 820 {
 821         Elf32_Shdr sh32;
 822         Elf64_Shdr sh64;
 823         int stripped = 1;
 824         void *nbuf;
 825         off_t noff;
 826         uint64_t cap_hw1 = 0;   /* SunOS 5.x hardware capabilites */
 827         uint64_t cap_sf1 = 0;   /* SunOS 5.x software capabilites */
 828
 829         if (size != xsh_sizeof) {
 830                 if (file_printf(ms, ", corrupted section header size") == -1)
 831                         return -1;
 832                 return 0;
 833         }
 834
 835         if (lseek(fd, off, SEEK_SET) == (off_t)-1) {
 836                 file_badseek(ms);
 837                 return -1;
 838         }
 839
 840         for ( ; num; num--) {
 841                 if (read(fd, xsh_addr, xsh_sizeof) == -1) {
 842                         file_badread(ms);
 843                         return -1;
 844                 }
 845                 switch (xsh_type) {
 846                 case SHT_SYMTAB:
 847 #if 0
 848                 case SHT_DYNSYM:
 849 #endif
 850                         stripped = 0;
 851                         break;
 852                 case SHT_NOTE:
 853                         if ((off = lseek(fd, (off_t)0, SEEK_CUR)) ==
 854                             (off_t)-1) {
 855                                 file_badread(ms);
 856                                 return -1;
 857                         }
 858                         if ((nbuf = malloc((size_t)xsh_size)) == NULL) {
 859                                 file_error(ms, errno, "Cannot allocate memory"
 860                                     " for note");
 861                                 return -1;
 862                         }
 863                         if ((noff = lseek(fd, (off_t)xsh_offset, SEEK_SET)) ==
 864                             (off_t)-1) {
 865                                 file_badread(ms);
 866                                 free(nbuf);
 867                                 return -1;
 868                         }
 869                         if (read(fd, nbuf, (size_t)xsh_size) !=
 870                             (ssize_t)xsh_size) {
 871                                 free(nbuf);
 872                                 file_badread(ms);
 873                                 return -1;
 874                         }
 875
 876                         noff = 0;
 877                         for (;;) {
 878                                 if (noff >= (size_t)xsh_size)
 879                                         break;
 880                                 noff = donote(ms, nbuf, (size_t)noff,
 881                                     (size_t)xsh_size, clazz, swap, 4,
 882                                     flags);
 883                                 if (noff == 0)
 884                                         break;
 885                         }
 886                         if ((lseek(fd, off, SEEK_SET)) == (off_t)-1) {
 887                                 free(nbuf);
 888                                 file_badread(ms);
 889                                 return -1;
 890                         }
 891                         free(nbuf);
 892                         break;
 893                 case SHT_SUNW_cap:
 894                     {
 895                         off_t coff;
 896                         if ((off = lseek(fd, (off_t)0, SEEK_CUR)) ==
 897                             (off_t)-1) {
 898                                 file_badread(ms);
 899                                 return -1;
 900                         }
 901                         if (lseek(fd, (off_t)xsh_offset, SEEK_SET) ==
 902                             (off_t)-1) {
 903                                 file_badread(ms);
 904                                 return -1;
 905                         }
 906                         coff = 0;
 907                         for (;;) {
 908                                 Elf32_Cap cap32;
 909                                 Elf64_Cap cap64;
 910                                 char cbuf[MAX(sizeof cap32, sizeof cap64)];
 911                                 if ((coff += xcap_sizeof) >= (size_t)xsh_size)
 912                                         break;
 913                                 if (read(fd, cbuf, (size_t)xcap_sizeof) !=
 914                                     (ssize_t)xcap_sizeof) {
 915                                         file_badread(ms);
 916                                         return -1;
 917                                 }
 918                                 (void)memcpy(xcap_addr, cbuf, xcap_sizeof);
 919                                 switch (xcap_tag) {
 920                                 case CA_SUNW_NULL:
 921                                         break;
 922                                 case CA_SUNW_HW_1:
 923                                         cap_hw1 |= xcap_val;
 924                                         break;
 925                                 case CA_SUNW_SF_1:
 926                                         cap_sf1 |= xcap_val;
 927                                         break;
 928                                 default:
 929                                         if (file_printf(ms,
 930                                             ", with unknown capability "
 931                                             "0x%llx = 0x%llx",
 932                                             xcap_tag, xcap_val) == -1)
 933                                                 return -1;
 934                                         break;
 935                                 }
 936                         }
 937                         if (lseek(fd, off, SEEK_SET) == (off_t)-1) {
 938                                 file_badread(ms);
 939                                 return -1;
 940                         }
 941                         break;
 942                     }
 943                 }
 944         }
 945         if (file_printf(ms, ", %sstripped", stripped ? "" : "not ") == -1)
 946                 return -1;
 947         if (cap_hw1) {
 948                 const cap_desc_t *cdp;
 949                 switch (mach) {
 950                 case EM_SPARC:
 951                 case EM_SPARC32PLUS:
 952                 case EM_SPARCV9:
 953                         cdp = cap_desc_sparc;
 954                         break;
 955                 case EM_386:
 956                 case EM_IA_64:
 957                 case EM_AMD64:
 958                         cdp = cap_desc_386;
 959                         break;
 960                 default:
 961                         cdp = NULL;
 962                         break;
 963                 }
 964                 if (file_printf(ms, ", uses") == -1)
 965                         return -1;
 966                 if (cdp) {
 967                         while (cdp->cd_name) {
 968                                 if (cap_hw1 & cdp->cd_mask) {
 969                                         if (file_printf(ms,
 970                                             " %s", cdp->cd_name) == -1)
 971                                                 return -1;
 972                                         cap_hw1 &= ~cdp->cd_mask;
 973                                 }
 974                                 ++cdp;
 975                         }
 976                         if (cap_hw1)
 977                                 if (file_printf(ms,
 978                                     " unknown hardware capability 0x%llx",
 979                                     cap_hw1) == -1)
 980                                         return -1;
 981                 } else {
 982                         if (file_printf(ms,
 983                             " hardware capability 0x%llx", cap_hw1) == -1)
 984                                 return -1;
 985                 }
 986         }
 987         if (cap_sf1) {
 988                 if (cap_sf1 & SF1_SUNW_FPUSED) {
 989                         if (file_printf(ms,
 990                             (cap_sf1 & SF1_SUNW_FPKNWN)
 991                             ? ", uses frame pointer"
 992                             : ", not known to use frame pointer") == -1)
 993                                 return -1;
 994                 }
 995                 cap_sf1 &= ~SF1_SUNW_MASK;
 996                 if (cap_sf1)
 997                         if (file_printf(ms,
 998                             ", with unknown software capability 0x%llx",
 999                             cap_sf1) == -1)
1000                                 return -1;
1001         }
1002         return 0;
1003 }
1004
1005 /*
1006  * Look through the program headers of an executable image, searching
1007  * for a PT_INTERP section; if one is found, it's dynamically linked,
1008  * otherwise it's statically linked.
1009  */
1010 private int
1011 dophn_exec(struct magic_set *ms, int clazz, int swap, int fd, off_t off,
1012     int num, size_t size, off_t fsize, int *flags, int sh_num)
1013 {
1014         Elf32_Phdr ph32;
1015         Elf64_Phdr ph64;
1016         const char *linking_style = "statically";
1017         const char *shared_libraries = "";
1018         unsigned char nbuf[BUFSIZ];
1019         int bufsize;
1020         size_t offset, align;
1021         off_t savedoffset = (off_t)-1;
1022         struct stat st;
1023
1024         if (fstat(fd, &st) < 0) {
1025                 file_badread(ms);
1026                 return -1;
1027         }
1028
1029         if (size != xph_sizeof) {
1030                 if (file_printf(ms, ", corrupted program header size") == -1)
1031                         return -1;
1032                 return 0;
1033         }
1034
1035         if (lseek(fd, off, SEEK_SET) == (off_t)-1) {
1036                 file_badseek(ms);
1037                 return -1;
1038         }
1039
1040         for ( ; num; num--) {
1041                 if (read(fd, xph_addr, xph_sizeof) == -1) {
1042                         file_badread(ms);
1043                         return -1;
1044                 }
1045                 if (xph_offset > st.st_size && savedoffset != (off_t)-1) {
1046                         if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
1047                                 file_badseek(ms);
1048                                 return -1;
1049                         }
1050                         continue;
1051                 }
1052
1053                 if ((savedoffset = lseek(fd, (off_t)0, SEEK_CUR)) == (off_t)-1) {
1054                         file_badseek(ms);
1055                         return -1;
1056                 }
1057
1058                 if (xph_offset > fsize) {
1059                         if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
1060                                 file_badseek(ms);
1061                                 return -1;
1062                         }
1063                         continue;
1064                 }
1065
1066                 switch (xph_type) {
1067                 case PT_DYNAMIC:
1068                         linking_style = "dynamically";
1069                         break;
1070                 case PT_INTERP:
1071                         shared_libraries = " (uses shared libs)";
1072                         break;
1073                 case PT_NOTE:
1074                         if ((align = xph_align) & 0x80000000) {
1075                                 if (file_printf(ms,
1076                                     ", invalid note alignment 0x%lx",
1077                                     (unsigned long)align) == -1)
1078                                         return -1;
1079                                 align = 4;
1080                         }
1081                         if (sh_num)
1082                                 break;
1083                         /*
1084                          * This is a PT_NOTE section; loop through all the notes
1085                          * in the section.
1086                          */
1087                         if (lseek(fd, xph_offset, SEEK_SET)
1088                             == (off_t)-1) {
1089                                 file_badseek(ms);
1090                                 return -1;
1091                         }
1092                         bufsize = read(fd, nbuf, ((xph_filesz < sizeof(nbuf)) ?
1093                             xph_filesz : sizeof(nbuf)));
1094                         if (bufsize == -1) {
1095                                 file_badread(ms);
1096                                 return -1;
1097                         }
1098                         offset = 0;
1099                         for (;;) {
1100                                 if (offset >= (size_t)bufsize)
1101                                         break;
1102                                 offset = donote(ms, nbuf, offset,
1103                                     (size_t)bufsize, clazz, swap, align,
1104                                     flags);
1105                                 if (offset == 0)
1106                                         break;
1107                         }
1108                         if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
1109                                 file_badseek(ms);
1110                                 return -1;
1111                         }
1112                         break;
1113                 default:
1114                         break;
1115                 }
1116         }
1117         if (file_printf(ms, ", %s linked%s", linking_style, shared_libraries)
1118             == -1)
1119             return -1;
1120         return 0;
1121 }
1122
1123
1124 protected int
1125 file_tryelf(struct magic_set *ms, int fd, const unsigned char *buf,
1126     size_t nbytes)
1127 {
1128         union {
1129                 int32_t l;
1130                 char c[sizeof (int32_t)];
1131         } u;
1132         int clazz;
1133         int swap;
1134         struct stat st;
1135         off_t fsize;
1136         int flags = 0;
1137         Elf32_Ehdr elf32hdr;
1138         Elf64_Ehdr elf64hdr;
1139         uint16_t type;
1140
1141         if (ms->flags & MAGIC_MIME)
1142                 return 0;
1143         /*
1144          * ELF executables have multiple section headers in arbitrary
1145          * file locations and thus file(1) cannot determine it from easily.
1146          * Instead we traverse thru all section headers until a symbol table
1147          * one is found or else the binary is stripped.
1148          * Return immediately if it's not ELF (so we avoid pipe2file unless needed).
1149          */
1150         if (buf[EI_MAG0] != ELFMAG0
1151             || (buf[EI_MAG1] != ELFMAG1 && buf[EI_MAG1] != OLFMAG1)
1152             || buf[EI_MAG2] != ELFMAG2 || buf[EI_MAG3] != ELFMAG3)
1153                 return 0;
1154
1155         /*
1156          * If we cannot seek, it must be a pipe, socket or fifo.
1157          */
1158         if((lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) && (errno == ESPIPE))
1159                 fd = file_pipe2file(ms, fd, buf, nbytes);
1160
1161         if (fstat(fd, &st) == -1) {
1162                 file_badread(ms);
1163                 return -1;
1164         }
1165         fsize = st.st_size;
1166
1167         clazz = buf[EI_CLASS];
1168
1169         switch (clazz) {
1170         case ELFCLASS32:
1171 #undef elf_getu
1172 #define elf_getu(a, b)  elf_getu32(a, b)
1173 #undef elfhdr
1174 #define elfhdr elf32hdr
1175 #include "elfclass.h"
1176         case ELFCLASS64:
1177 #undef elf_getu
1178 #define elf_getu(a, b)  elf_getu64(a, b)
1179 #undef elfhdr
1180 #define elfhdr elf64hdr
1181 #include "elfclass.h"
1182         default:
1183             if (file_printf(ms, ", unknown class %d", clazz) == -1)
1184                     return -1;
1185             break;
1186         }
1187         return 0;
1188 }
1189 #endif