/* $OpenBSD: readelf.c,v 1.12 2014/11/04 16:18:54 deraadt Exp $ */ /* * Copyright (c) Christos Zoulas 2003. * All Rights Reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice immediately at the beginning of the file, without modification, * this list of conditions, and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include "file.h" #ifdef BUILTIN_ELF #include #include #include #ifdef HAVE_UNISTD_H #include #endif #include "readelf.h" #include "magic.h" #ifdef ELFCORE private int dophn_core(struct magic_set *, int, int, int, off_t, int, size_t, off_t, int *); #endif private int dophn_exec(struct magic_set *, int, int, int, off_t, int, size_t, off_t, int *); private int doshn(struct magic_set *, int, int, int, off_t, int, size_t, int *); private size_t donote(struct magic_set *, unsigned char *, size_t, size_t, int, int, size_t, int *); #define ELF_ALIGN(a) ((((a) + align - 1) / align) * align) #define isquote(c) (strchr("'\"`", (c)) != NULL) private uint16_t getu16(int, uint16_t); private uint32_t getu32(int, uint32_t); private uint64_t getu64(int, uint64_t); private uint16_t getu16(int swap, uint16_t value) { union { uint16_t ui; char c[2]; } retval, tmpval; if (swap) { tmpval.ui = value; retval.c[0] = tmpval.c[1]; retval.c[1] = tmpval.c[0]; return retval.ui; } else return value; } private uint32_t getu32(int swap, uint32_t value) { union { uint32_t ui; char c[4]; } retval, tmpval; if (swap) { tmpval.ui = value; retval.c[0] = tmpval.c[3]; retval.c[1] = tmpval.c[2]; retval.c[2] = tmpval.c[1]; retval.c[3] = tmpval.c[0]; return retval.ui; } else return value; } private uint64_t getu64(int swap, uint64_t value) { union { uint64_t ui; char c[8]; } retval, tmpval; if (swap) { tmpval.ui = value; retval.c[0] = tmpval.c[7]; retval.c[1] = tmpval.c[6]; retval.c[2] = tmpval.c[5]; retval.c[3] = tmpval.c[4]; retval.c[4] = tmpval.c[3]; retval.c[5] = tmpval.c[2]; retval.c[6] = tmpval.c[1]; retval.c[7] = tmpval.c[0]; return retval.ui; } else return value; } #define elf_getu16(swap, value) getu16(swap, value) #define elf_getu32(swap, value) getu32(swap, value) #ifdef USE_ARRAY_FOR_64BIT_TYPES # define elf_getu64(swap, array) \ ((swap ? ((uint64_t)elf_getu32(swap, array[0])) << 32 : elf_getu32(swap, array[0])) + \ (swap ? elf_getu32(swap, array[1]) : ((uint64_t)elf_getu32(swap, array[1]) << 32))) #else # define elf_getu64(swap, value) getu64(swap, value) #endif #define xsh_addr (class == ELFCLASS32 \ ? (void *) &sh32 \ : (void *) &sh64) #define xsh_sizeof (class == ELFCLASS32 \ ? sizeof sh32 \ : sizeof sh64) #define xsh_size (class == ELFCLASS32 \ ? elf_getu32(swap, sh32.sh_size) \ : elf_getu64(swap, sh64.sh_size)) #define xsh_offset (class == ELFCLASS32 \ ? elf_getu32(swap, sh32.sh_offset) \ : elf_getu64(swap, sh64.sh_offset)) #define xsh_type (class == ELFCLASS32 \ ? elf_getu32(swap, sh32.sh_type) \ : elf_getu32(swap, sh64.sh_type)) #define xph_addr (class == ELFCLASS32 \ ? (void *) &ph32 \ : (void *) &ph64) #define xph_sizeof (class == ELFCLASS32 \ ? sizeof ph32 \ : sizeof ph64) #define xph_type (class == ELFCLASS32 \ ? elf_getu32(swap, ph32.p_type) \ : elf_getu32(swap, ph64.p_type)) #define xph_offset (off_t)(class == ELFCLASS32 \ ? elf_getu32(swap, ph32.p_offset) \ : elf_getu64(swap, ph64.p_offset)) #define xph_align (size_t)((class == ELFCLASS32 \ ? (off_t) (ph32.p_align ? \ elf_getu32(swap, ph32.p_align) : 4) \ : (off_t) (ph64.p_align ? \ elf_getu64(swap, ph64.p_align) : 4))) #define xph_filesz (size_t)((class == ELFCLASS32 \ ? elf_getu32(swap, ph32.p_filesz) \ : elf_getu64(swap, ph64.p_filesz))) #define xnh_addr (class == ELFCLASS32 \ ? (void *) &nh32 \ : (void *) &nh64) #define xph_memsz (size_t)((class == ELFCLASS32 \ ? elf_getu32(swap, ph32.p_memsz) \ : elf_getu64(swap, ph64.p_memsz))) #define xnh_sizeof (class == ELFCLASS32 \ ? sizeof nh32 \ : sizeof nh64) #define xnh_type (class == ELFCLASS32 \ ? elf_getu32(swap, nh32.n_type) \ : elf_getu32(swap, nh64.n_type)) #define xnh_namesz (class == ELFCLASS32 \ ? elf_getu32(swap, nh32.n_namesz) \ : elf_getu32(swap, nh64.n_namesz)) #define xnh_descsz (class == ELFCLASS32 \ ? elf_getu32(swap, nh32.n_descsz) \ : elf_getu32(swap, nh64.n_descsz)) #define prpsoffsets(i) (class == ELFCLASS32 \ ? prpsoffsets32[i] \ : prpsoffsets64[i]) #ifdef ELFCORE /* * Try larger offsets first to avoid false matches * from earlier data that happen to look like strings. */ static const size_t prpsoffsets32[] = { #ifdef USE_NT_PSINFO 104, /* SunOS 5.x (command line) */ 88, /* SunOS 5.x (short name) */ #endif /* USE_NT_PSINFO */ 100, /* SunOS 5.x (command line) */ 84, /* SunOS 5.x (short name) */ 44, /* Linux (command line) */ 28, /* Linux 2.0.36 (short name) */ 8, /* FreeBSD */ }; static const size_t prpsoffsets64[] = { #ifdef USE_NT_PSINFO 152, /* SunOS 5.x (command line) */ 136, /* SunOS 5.x (short name) */ #endif /* USE_NT_PSINFO */ 136, /* SunOS 5.x, 64-bit (command line) */ 120, /* SunOS 5.x, 64-bit (short name) */ 56, /* Linux (command line) */ 40, /* Linux (tested on core from 2.4.x, short name) */ 16, /* FreeBSD, 64-bit */ }; #define NOFFSETS32 (sizeof prpsoffsets32 / sizeof prpsoffsets32[0]) #define NOFFSETS64 (sizeof prpsoffsets64 / sizeof prpsoffsets64[0]) #define NOFFSETS (class == ELFCLASS32 ? NOFFSETS32 : NOFFSETS64) /* * Look through the program headers of an executable image, searching * for a PT_NOTE section of type NT_PRPSINFO, with a name "CORE" or * "FreeBSD"; if one is found, try looking in various places in its * contents for a 16-character string containing only printable * characters - if found, that string should be the name of the program * that dropped core. Note: right after that 16-character string is, * at least in SunOS 5.x (and possibly other SVR4-flavored systems) and * Linux, a longer string (80 characters, in 5.x, probably other * SVR4-flavored systems, and Linux) containing the start of the * command line for that program. * * SunOS 5.x core files contain two PT_NOTE sections, with the types * NT_PRPSINFO (old) and NT_PSINFO (new). These structs contain the * same info about the command name and command line, so it probably * isn't worthwhile to look for NT_PSINFO, but the offsets are provided * above (see USE_NT_PSINFO), in case we ever decide to do so. The * NT_PRPSINFO and NT_PSINFO sections are always in order and adjacent; * the SunOS 5.x file command relies on this (and prefers the latter). * * The signal number probably appears in a section of type NT_PRSTATUS, * but that's also rather OS-dependent, in ways that are harder to * dissect with heuristics, so I'm not bothering with the signal number. * (I suppose the signal number could be of interest in situations where * you don't have the binary of the program that dropped core; if you * *do* have that binary, the debugger will probably tell you what * signal it was.) */ #define OS_STYLE_SVR4 0 #define OS_STYLE_FREEBSD 1 #define OS_STYLE_NETBSD 2 private const char os_style_names[][8] = { "SVR4", "FreeBSD", "NetBSD", }; #define FLAGS_DID_CORE 1 #define FLAGS_DID_NOTE 2 #define FLAGS_DID_CORE_STYLE 4 private int dophn_core(struct magic_set *ms, int class, int swap, int fd, off_t off, int num, size_t size, off_t fsize, int *flags) { Elf32_Phdr ph32; Elf64_Phdr ph64; size_t offset; unsigned char nbuf[BUFSIZ]; ssize_t bufsize; off_t savedoffset; struct stat st; if (fstat(fd, &st) < 0) { file_badread(ms); return -1; } if (size != xph_sizeof) { if (file_printf(ms, ", corrupted program header size") == -1) return -1; return 0; } /* * Loop through all the program headers. */ for ( ; num; num--) { if ((savedoffset = lseek(fd, off, SEEK_SET)) == (off_t)-1) { file_badseek(ms); return -1; } if (read(fd, xph_addr, xph_sizeof) == -1) { file_badread(ms); return -1; } if (xph_offset > fsize) { if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) { file_badseek(ms); return -1; } continue; } off += size; if (xph_type != PT_NOTE) continue; /* * This is a PT_NOTE section; loop through all the notes * in the section. */ if (lseek(fd, xph_offset, SEEK_SET) == (off_t)-1) { file_badseek(ms); return -1; } bufsize = read(fd, nbuf, ((xph_filesz < sizeof(nbuf)) ? xph_filesz : sizeof(nbuf))); if (bufsize == -1) { file_badread(ms); return -1; } offset = 0; for (;;) { if (offset >= (size_t)bufsize) break; offset = donote(ms, nbuf, offset, (size_t)bufsize, class, swap, 4, flags); if (offset == 0) break; } } return 0; } #endif private size_t donote(struct magic_set *ms, unsigned char *nbuf, size_t offset, size_t size, int class, int swap, size_t align, int *flags) { Elf32_Nhdr nh32; Elf64_Nhdr nh64; size_t noff, doff; #ifdef ELFCORE int os_style = -1; #endif uint32_t namesz, descsz; if (xnh_sizeof + offset > size) { /* * We're out of note headers. */ return xnh_sizeof + offset; } (void)memcpy(xnh_addr, &nbuf[offset], xnh_sizeof); offset += xnh_sizeof; namesz = xnh_namesz; descsz = xnh_descsz; if ((namesz == 0) && (descsz == 0)) { /* * We're out of note headers. */ return (offset >= size) ? offset : size; } if (namesz & 0x80000000) { (void)file_printf(ms, ", bad note name size 0x%lx", (unsigned long)namesz); return offset; } if (descsz & 0x80000000) { (void)file_printf(ms, ", bad note description size 0x%lx", (unsigned long)descsz); return offset; } noff = offset; doff = ELF_ALIGN(offset + namesz); if (offset + namesz > size) { /* * We're past the end of the buffer. */ return doff; } offset = ELF_ALIGN(doff + descsz); if (doff + descsz > size) { /* * We're past the end of the buffer. */ return (offset >= size) ? offset : size; } if (*flags & FLAGS_DID_NOTE) goto core; if (namesz == 4 && strcmp((char *)&nbuf[noff], "GNU") == 0 && xnh_type == NT_GNU_VERSION && descsz == 16) { uint32_t desc[4]; (void)memcpy(desc, &nbuf[doff], sizeof(desc)); if (file_printf(ms, ", for GNU/") == -1) return size; switch (elf_getu32(swap, desc[0])) { case GNU_OS_LINUX: if (file_printf(ms, "Linux") == -1) return size; break; case GNU_OS_HURD: if (file_printf(ms, "Hurd") == -1) return size; break; case GNU_OS_SOLARIS: if (file_printf(ms, "Solaris") == -1) return size; break; case GNU_OS_KFREEBSD: if (file_printf(ms, "kFreeBSD") == -1) return size; break; case GNU_OS_KNETBSD: if (file_printf(ms, "kNetBSD") == -1) return size; break; default: if (file_printf(ms, "") == -1) return size; } if (file_printf(ms, " %d.%d.%d", elf_getu32(swap, desc[1]), elf_getu32(swap, desc[2]), elf_getu32(swap, desc[3])) == -1) return size; *flags |= FLAGS_DID_NOTE; return size; } if (namesz == 7 && strcmp((char *)&nbuf[noff], "NetBSD") == 0 && xnh_type == NT_NETBSD_VERSION && descsz == 4) { uint32_t desc; (void)memcpy(&desc, &nbuf[doff], sizeof(desc)); desc = elf_getu32(swap, desc); if (file_printf(ms, ", for NetBSD") == -1) return size; /* * The version number used to be stuck as 199905, and was thus * basically content-free. Newer versions of NetBSD have fixed * this and now use the encoding of __NetBSD_Version__: * * MMmmrrpp00 * * M = major version * m = minor version * r = release ["",A-Z,Z[A-Z] but numeric] * p = patchlevel */ if (desc > 100000000U) { uint32_t ver_patch = (desc / 100) % 100; uint32_t ver_rel = (desc / 10000) % 100; uint32_t ver_min = (desc / 1000000) % 100; uint32_t ver_maj = desc / 100000000; if (file_printf(ms, " %u.%u", ver_maj, ver_min) == -1) return size; if (ver_rel == 0 && ver_patch != 0) { if (file_printf(ms, ".%u", ver_patch) == -1) return size; } else if (ver_rel != 0) { while (ver_rel > 26) { if (file_printf(ms, "Z") == -1) return size; ver_rel -= 26; } if (file_printf(ms, "%c", 'A' + ver_rel - 1) == -1) return size; } } *flags |= FLAGS_DID_NOTE; return size; } if (namesz == 8 && strcmp((char *)&nbuf[noff], "FreeBSD") == 0 && xnh_type == NT_FREEBSD_VERSION && descsz == 4) { uint32_t desc; (void)memcpy(&desc, &nbuf[doff], sizeof(desc)); desc = elf_getu32(swap, desc); if (file_printf(ms, ", for FreeBSD") == -1) return size; /* * Contents is __FreeBSD_version, whose relation to OS * versions is defined by a huge table in the Porter's * Handbook. This is the general scheme: * * Releases: * Mmp000 (before 4.10) * Mmi0p0 (before 5.0) * Mmm0p0 * * Development branches: * Mmpxxx (before 4.6) * Mmp1xx (before 4.10) * Mmi1xx (before 5.0) * M000xx (pre-M.0) * Mmm1xx * * M = major version * m = minor version * i = minor version increment (491000 -> 4.10) * p = patchlevel * x = revision * * The first release of FreeBSD to use ELF by default * was version 3.0. */ if (desc == 460002) { if (file_printf(ms, " 4.6.2") == -1) return size; } else if (desc < 460100) { if (file_printf(ms, " %d.%d", desc / 100000, desc / 10000 % 10) == -1) return size; if (desc / 1000 % 10 > 0) if (file_printf(ms, ".%d", desc / 1000 % 10) == -1) return size; if ((desc % 1000 > 0) || (desc % 100000 == 0)) if (file_printf(ms, " (%d)", desc) == -1) return size; } else if (desc < 500000) { if (file_printf(ms, " %d.%d", desc / 100000, desc / 10000 % 10 + desc / 1000 % 10) == -1) return size; if (desc / 100 % 10 > 0) { if (file_printf(ms, " (%d)", desc) == -1) return size; } else if (desc / 10 % 10 > 0) { if (file_printf(ms, ".%d", desc / 10 % 10) == -1) return size; } } else { if (file_printf(ms, " %d.%d", desc / 100000, desc / 1000 % 100) == -1) return size; if ((desc / 100 % 10 > 0) || (desc % 100000 / 100 == 0)) { if (file_printf(ms, " (%d)", desc) == -1) return size; } else if (desc / 10 % 10 > 0) { if (file_printf(ms, ".%d", desc / 10 % 10) == -1) return size; } } *flags |= FLAGS_DID_NOTE; return size; } if (namesz == 8 && strcmp((char *)&nbuf[noff], "OpenBSD") == 0 && xnh_type == NT_OPENBSD_VERSION && descsz == 4) { if (file_printf(ms, ", for OpenBSD") == -1) return size; /* Content of note is always 0 */ *flags |= FLAGS_DID_NOTE; return size; } if (namesz == 10 && strcmp((char *)&nbuf[noff], "DragonFly") == 0 && xnh_type == NT_DRAGONFLY_VERSION && descsz == 4) { uint32_t desc; if (file_printf(ms, ", for DragonFly") == -1) return size; (void)memcpy(&desc, &nbuf[doff], sizeof(desc)); desc = elf_getu32(swap, desc); if (file_printf(ms, " %d.%d.%d", desc / 100000, desc / 10000 % 10, desc % 10000) == -1) return size; *flags |= FLAGS_DID_NOTE; return size; } core: /* * Sigh. The 2.0.36 kernel in Debian 2.1, at * least, doesn't correctly implement name * sections, in core dumps, as specified by * the "Program Linking" section of "UNIX(R) System * V Release 4 Programmer's Guide: ANSI C and * Programming Support Tools", because my copy * clearly says "The first 'namesz' bytes in 'name' * contain a *null-terminated* [emphasis mine] * character representation of the entry's owner * or originator", but the 2.0.36 kernel code * doesn't include the terminating null in the * name.... */ if ((namesz == 4 && strncmp((char *)&nbuf[noff], "CORE", 4) == 0) || (namesz == 5 && strcmp((char *)&nbuf[noff], "CORE") == 0)) { os_style = OS_STYLE_SVR4; } if ((namesz == 8 && strcmp((char *)&nbuf[noff], "FreeBSD") == 0)) { os_style = OS_STYLE_FREEBSD; } if ((namesz >= 11 && strncmp((char *)&nbuf[noff], "NetBSD-CORE", 11) == 0)) { os_style = OS_STYLE_NETBSD; } #ifdef ELFCORE if ((*flags & FLAGS_DID_CORE) != 0) return size; if (os_style != -1 && (*flags & FLAGS_DID_CORE_STYLE) == 0) { if (file_printf(ms, ", %s-style", os_style_names[os_style]) == -1) return size; *flags |= FLAGS_DID_CORE_STYLE; } switch (os_style) { case OS_STYLE_NETBSD: if (xnh_type == NT_NETBSD_CORE_PROCINFO) { uint32_t signo; /* * Extract the program name. It is at * offset 0x7c, and is up to 32-bytes, * including the terminating NUL. */ if (file_printf(ms, ", from '%.31s'", &nbuf[doff + 0x7c]) == -1) return size; /* * Extract the signal number. It is at * offset 0x08. */ (void)memcpy(&signo, &nbuf[doff + 0x08], sizeof(signo)); if (file_printf(ms, " (signal %u)", elf_getu32(swap, signo)) == -1) return size; *flags |= FLAGS_DID_CORE; return size; } break; default: if (xnh_type == NT_PRPSINFO) { size_t i, j; unsigned char c; /* * Extract the program name. We assume * it to be 16 characters (that's what it * is in SunOS 5.x and Linux). * * Unfortunately, it's at a different offset * in various OSes, so try multiple offsets. * If the characters aren't all printable, * reject it. */ for (i = 0; i < NOFFSETS; i++) { unsigned char *cname, *cp; size_t reloffset = prpsoffsets(i); size_t noffset = doff + reloffset; for (j = 0; j < 16; j++, noffset++, reloffset++) { /* * Make sure we're not past * the end of the buffer; if * we are, just give up. */ if (noffset >= size) goto tryanother; /* * Make sure we're not past * the end of the contents; * if we are, this obviously * isn't the right offset. */ if (reloffset >= descsz) goto tryanother; c = nbuf[noffset]; if (c == '\0') { /* * A '\0' at the * beginning is * obviously wrong. * Any other '\0' * means we're done. */ if (j == 0) goto tryanother; else break; } else { /* * A nonprintable * character is also * wrong. */ if (!isprint(c) || isquote(c)) goto tryanother; } } /* * Well, that worked. */ cname = (unsigned char *) &nbuf[doff + prpsoffsets(i)]; for (cp = cname; *cp && isprint(*cp); cp++) continue; /* * Linux apparently appends a space at the end * of the command line: remove it. */ while (cp > cname && isspace(cp[-1])) cp--; if (file_printf(ms, ", from '%.*s'", (int)(cp - cname), cname) == -1) return size; *flags |= FLAGS_DID_CORE; return size; tryanother: ; } } break; } #endif return offset; } private int doshn(struct magic_set *ms, int class, int swap, int fd, off_t off, int num, size_t size, int *flags) { Elf32_Shdr sh32; Elf64_Shdr sh64; int stripped = 1; void *nbuf; off_t noff; if (size != xsh_sizeof) { if (file_printf(ms, ", corrupted section header size") == -1) return -1; return 0; } if (lseek(fd, off, SEEK_SET) == (off_t)-1) { file_badseek(ms); return -1; } for ( ; num; num--) { if (read(fd, xsh_addr, xsh_sizeof) == -1) { file_badread(ms); return -1; } switch (xsh_type) { case SHT_SYMTAB: #if 0 case SHT_DYNSYM: #endif stripped = 0; break; case SHT_NOTE: if ((off = lseek(fd, (off_t)0, SEEK_CUR)) == (off_t)-1) { file_badread(ms); return -1; } if ((nbuf = malloc((size_t)xsh_size)) == NULL) { file_error(ms, errno, "Cannot allocate memory" " for note"); return -1; } if ((noff = lseek(fd, (off_t)xsh_offset, SEEK_SET)) == (off_t)-1) { file_badread(ms); free(nbuf); return -1; } if (read(fd, nbuf, (size_t)xsh_size) != (ssize_t)xsh_size) { free(nbuf); file_badread(ms); return -1; } noff = 0; for (;;) { if (noff >= (size_t)xsh_size) break; noff = donote(ms, nbuf, (size_t)noff, (size_t)xsh_size, class, swap, 4, flags); if (noff == 0) break; } if ((lseek(fd, off, SEEK_SET)) == (off_t)-1) { free(nbuf); file_badread(ms); return -1; } free(nbuf); break; } } if (file_printf(ms, ", %sstripped", stripped ? "" : "not ") == -1) return -1; return 0; } /* * Look through the program headers of an executable image, searching * for a PT_INTERP section; if one is found, it's dynamically linked, * otherwise it's statically linked. */ private int dophn_exec(struct magic_set *ms, int class, int swap, int fd, off_t off, int num, size_t size, off_t fsize, int *flags) { Elf32_Phdr ph32; Elf64_Phdr ph64; const char *linking_style = "statically"; const char *shared_libraries = ""; unsigned char nbuf[BUFSIZ]; int bufsize; size_t offset, align; off_t savedoffset = (off_t)-1; struct stat st; if (fstat(fd, &st) < 0) { file_badread(ms); return -1; } if (size != xph_sizeof) { if (file_printf(ms, ", corrupted program header size") == -1) return -1; return 0; } if (lseek(fd, off, SEEK_SET) == (off_t)-1) { file_badseek(ms); return -1; } for ( ; num; num--) { if (read(fd, xph_addr, xph_sizeof) == -1) { file_badread(ms); return -1; } if (xph_offset > st.st_size && savedoffset != (off_t)-1) { if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) { file_badseek(ms); return -1; } continue; } if ((savedoffset = lseek(fd, (off_t)0, SEEK_CUR)) == (off_t)-1) { file_badseek(ms); return -1; } if (xph_offset > fsize) { if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) { file_badseek(ms); return -1; } continue; } switch (xph_type) { case PT_DYNAMIC: linking_style = "dynamically"; break; case PT_INTERP: shared_libraries = " (uses shared libs)"; break; case PT_NOTE: if ((align = xph_align) & 0x80000000) { if (file_printf(ms, ", invalid note alignment 0x%lx", (unsigned long)align) == -1) return -1; align = 4; } /* * This is a PT_NOTE section; loop through all the notes * in the section. */ if (lseek(fd, xph_offset, SEEK_SET) == (off_t)-1) { file_badseek(ms); return -1; } bufsize = read(fd, nbuf, ((xph_filesz < sizeof(nbuf)) ? xph_filesz : sizeof(nbuf))); if (bufsize == -1) { file_badread(ms); return -1; } offset = 0; for (;;) { if (offset >= (size_t)bufsize) break; offset = donote(ms, nbuf, offset, (size_t)bufsize, class, swap, align, flags); if (offset == 0) break; } if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) { file_badseek(ms); return -1; } break; default: break; } } if (file_printf(ms, ", %s linked%s", linking_style, shared_libraries) == -1) return -1; return 0; } protected int file_tryelf(struct magic_set *ms, int fd, const unsigned char *buf, size_t nbytes) { union { int32_t l; char c[sizeof (int32_t)]; } u; int class; int swap; struct stat st; off_t fsize; int flags = 0; Elf32_Ehdr elf32hdr; Elf64_Ehdr elf64hdr; uint16_t type; if (ms->flags & MAGIC_MIME) return 0; /* * ELF executables have multiple section headers in arbitrary * file locations and thus file(1) cannot determine it from easily. * Instead we traverse thru all section headers until a symbol table * one is found or else the binary is stripped. * Return immediately if it's not ELF (so we avoid pipe2file unless needed). */ if (buf[EI_MAG0] != ELFMAG0 || (buf[EI_MAG1] != ELFMAG1 && buf[EI_MAG1] != OLFMAG1) || buf[EI_MAG2] != ELFMAG2 || buf[EI_MAG3] != ELFMAG3) return 0; /* * If we cannot seek, it must be a pipe, socket or fifo. */ if((lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) && (errno == ESPIPE)) fd = file_pipe2file(ms, fd, buf, nbytes); if (fstat(fd, &st) == -1) { file_badread(ms); return -1; } fsize = st.st_size; class = buf[EI_CLASS]; switch (class) { case ELFCLASS32: #undef elf_getu #define elf_getu(a, b) elf_getu32(a, b) #undef elfhdr #define elfhdr elf32hdr #include "elfclass.h" case ELFCLASS64: #undef elf_getu #define elf_getu(a, b) elf_getu64(a, b) #undef elfhdr #define elfhdr elf64hdr #include "elfclass.h" default: if (file_printf(ms, ", unknown class %d", class) == -1) return -1; break; } return 0; } #endif