Путь: Toys/POSIX, команды версии: Ver.4 Ver.9 file Комментарии в файле file.c :
Исходный текст в файле file.c #define FOR_file
#include "toys.h"
GLOBALS(
int max_name_len;
off_t len;
)
// We don't trust elf.h to be there, and two codepaths for 32/64 is awkward
// anyway, so calculate struct offsets manually. (It's a fixed ABI.)
static void do_elf_file(int fd)
{
unsigned endian = toybuf[5], bits = toybuf[4]-1, i, j, dynamic = 0,
stripped = 1, phentsize, phnum, shsize, shnum, bail = 0;
int64_t (*elf_int)(void *ptr, unsigned size) = (endian==2)?peek_be:peek_le;
char *map = MAP_FAILED;
unsigned long phoff, shoff;
printf("ELF ");
// executable type
i = elf_int(toybuf+16, 2);
if (i == 1) printf("relocatable");
else if (i == 2) printf("executable");
else if (i == 3) printf("shared object");
else if (i == 4) printf("core dump");
else {
printf("(bad type %d)", i);
bail++;
}
if (elf_int(toybuf+36+12*!!bits, 4) & 0x8000) printf(" (fdpic)");
printf(", ");
// "64-bit"
if (bits&~1) {
printf("(bad class %d) ", bits);
bail++;
} else printf("%d-bit ", 32<<bits);
// "LSB"
if (endian == 1) printf("LSB ");
else if (endian == 2) printf("MSB ");
else {
printf("(bad endian %d) ", endian);
bail++;
}
// "x86".
printf("%s", elf_arch_name(elf_int(toybuf+18, 2)));
// If what we've seen so far doesn't seem consistent, bail.
if (bail) goto bad;
// Stash what we need from the header; it's okay to reuse toybuf after this.
phentsize = elf_int(toybuf+42+12*bits, 2);
phnum = elf_int(toybuf+44+12*bits, 2);
phoff = elf_int(toybuf+28+4*bits, 4+4*bits);
shsize = elf_int(toybuf+46+12*bits, 2);
shnum = elf_int(toybuf+48+12*bits, 2);
shoff = elf_int(toybuf+32+8*bits, 4+4*bits);
// With binutils, phentsize seems to only be non-zero if phnum is non-zero.
// Such ELF files are rare, but do exist. (Android's crtbegin files, say.)
if (phnum && (phentsize != 32+24*bits)) {
printf(", bad phentsize %d?", phentsize);
goto bad;
}
if (phoff>TT.len || phnum*phentsize>TT.len-phoff) {
printf(", bad phoff %lu?", phoff);
goto bad;
}
if (shoff>TT.len || shnum*shsize>TT.len-shoff) {
printf(", bad shoff %lu?", phoff);
goto bad;
}
// Parsing ELF means following tables that may point to data earlier in
// the file, so sequential reading involves buffering unknown amounts of
// data. Just skip it if we can't mmap.
if (MAP_FAILED == (map = mmap(0, TT.len, PROT_READ, MAP_SHARED, fd, 0))) {
perror_msg("mmap");
goto bad;
}
// Read the phdrs for dynamic vs static. (Note: fields reordered on 64 bit)
for (i = 0; i<phnum; i++) {
char *phdr = map+phoff+i*phentsize;
unsigned p_type = elf_int(phdr, 4);
unsigned long long p_offset, p_filesz;
// TODO: what does PT_DYNAMIC without PT_INTERP mean?
if (p_type-2>2) continue; // 2 = PT_DYNAMIC, 3 = PT_INTERP, 4 = PT_NOTE
dynamic |= p_type==2;
p_offset = elf_int(phdr+(4<<bits), 4<<bits);
p_filesz = elf_int(phdr+(16<<bits), 4<<bits);
if (p_type==3) {
if (p_filesz>TT.len || p_offset>TT.len-p_filesz) {
printf(", bad phdr %d?", i);
goto bad;
}
// TODO: if (int)<0 prints endlessly, could go off end of map?
printf(", dynamic (%.*s)", (int)p_filesz, map+p_offset);
}
}
if (!dynamic) printf(", static");
// We need to read the shdrs for stripped/unstripped and any notes.
// Notes are in program headers *and* section headers, but some files don't
// contain program headers, so check here. (Note: fields reordered on 64 bit)
for (i = 0; i<shnum; i++) {
char *shdr = map+shoff+i*shsize;
unsigned long sh_offset;
int sh_type, sh_size;
if (shdr>map+TT.len-(8+(4<<bits))) {
printf(", bad shdr %d?", i);
goto bad;
}
sh_type = elf_int(shdr+4, 4);
sh_offset = elf_int(shdr+8+(8<<bits), 4<<bits);
sh_size = elf_int(shdr+8+(12<<bits), 4);
if (sh_type == 8 /*SHT_NOBITS*/) sh_size = 0;
if (sh_offset>TT.len || sh_size>TT.len-sh_offset) {
printf(", bad shdr %d?", i);
goto bad;
}
if (sh_type == 2 /*SHT_SYMTAB*/) {
stripped = 0;
break;
} else if (sh_type == 7 /*SHT_NOTE*/) {
char *note = map+sh_offset;
// An ELF note is a sequence of entries, each consisting of an
// ndhr followed by n_namesz+n_descsz bytes of data (each of those
// rounded up to the next 4 bytes, without this being reflected in
// the header byte counts themselves).
while (sh_size >= 3*4) { // Don't try to read a truncated entry.
unsigned n_namesz, n_descsz, n_type, notesz;
if (note>map+TT.len-3*4) {
printf(", bad note %d?", i);
goto bad;
}
n_namesz = elf_int(note, 4);
n_descsz = elf_int(note+4, 4);
n_type = elf_int(note+8, 4);
notesz = 3*4 + ((n_namesz+3)&~3) + ((n_descsz+3)&~3);
// Are the name/desc sizes consistent, and does the claimed size of
// the note actually fit in the section?
if (notesz<n_namesz || notesz<n_descsz || notesz>sh_size) {
printf(", bad note %d size?", i);
goto bad;
}
if (n_namesz==4 && !smemcmp(note+12, "GNU", 4) && n_type==3) {
printf(", BuildID=");
for (j = 0; j<n_descsz; j++) printf("%02x", note[16+j]);
} else if (n_namesz==8 && !smemcmp(note+12, "Android", 8)) {
if (n_type==1 /*.android.note.ident*/ && n_descsz >= 4) {
printf(", for Android %d", (int)elf_int(note+20, 4));
// NDK r14 and later also include NDK version info. OS binaries
// and binaries built by older NDKs don't have this.
if (n_descsz >= 4+64+64)
printf(", built by NDK %.64s (%.64s)", note+24, note+24+64);
}
}
note += notesz;
sh_size -= notesz;
}
}
}
printf(", %sstripped", stripped ? "" : "not ");
bad:
xputc('\n');
if (map != MAP_FAILED) munmap(map, TT.len);
}
static void do_regular_file(int fd, char *name)
{
char *s = toybuf;
unsigned len, magic;
int ii;
// zero through elf shnum, just in case
memset(s, 0, 80);
if ((len = readall(fd, s, sizeof(toybuf)-8))<0) perror_msg("%s", name);
if (!len) xputs("empty");
// 45 bytes: https://www.muppetlabs.com/~breadbox/software/tiny/teensy.html
else if (len>=45 && strstart(&s, "\177ELF")) do_elf_file(fd);
else if (strstart(&s, "!<arch>\n")) xputs("ar archive");
else if (*s=='%' && 2==sscanf(s, "%%PDF%d.%u", &ii, &magic))
xprintf("PDF document, version %d.%u\n", -ii, magic);
else if (len>28 && strstart(&s, "\x89PNG\x0d\x0a\x1a\x0a")) {
// PNG is big-endian: https://www.w3.org/TR/PNG/#7Integers-and-byte-order
int chunk_length = peek_be(s, 4);
xprintf("PNG image data");
// The IHDR chunk comes first: https://www.w3.org/TR/PNG/#11IHDR
s += 4;
if (chunk_length == 13 && strstart(&s, "IHDR")) {
// https://www.w3.org/TR/PNG/#6Colour-values
char *c = 0, *colors[] = {"grayscale", 0, "color RGB", "indexed color",
"grayscale with alpha", 0, "color RGBA"};
if (s[9]<ARRAY_LEN(colors)) c = colors[s[9]];
xprintf(", %d x %d, %d-bit/%s, %sinterlaced", (int)peek_be(s, 4),
(int)peek_be(s+4, 4), s[8], c ? : "unknown", s[12] ? "" : "non-");
}
xputc('\n');
// https://www.w3.org/Graphics/GIF/spec-gif89a.txt
} else if (len>16 && (strstart(&s, "GIF87a") || strstart(&s, "GIF89a")))
xprintf("GIF image data, version %3.3s, %d x %d\n",
s-3, (int)peek_le(s, 2), (int)peek_le(s+2, 2));
// TODO: parsing JPEG for width/height is harder than GIF or PNG.
else if (len>32 && !smemcmp(s, "\xff\xd8", 2)) xputs("JPEG image data");
else if (len>8 && strstart(&s, "\xca\xfe\xba\xbe")) {
unsigned count = peek_be(s, 4), i, arch;
// 0xcafebabe can be a Java class file or a Mach-O universal binary.
// Java major version numbers start with 0x2d for JDK 1.1, and realistically
// you're never going to see more than 2 architectures in a binary anyway...
if (count<0x2d && len>=(count*20)) {
// https://eclecticlight.co/2020/07/28/universal-binaries-inside-fat-headers/
xprintf("Mach-O universal binary with %u architecture%s:",
count, count == 1 ? "" : "s");
for (i = 0, s += 4; i < count; i++, s += 20) {
arch = peek_be(s, 4);
if (arch == 0x00000007) name = "i386";
else if (arch == 0x01000007) name = "x86_64";
else if (arch == 0x0000000c) name = "arm";
else if (arch == 0x0100000c) name = "arm64";
else name = "unknown";
xprintf(" [%s]", name);
}
xprintf("\n");
} else {
// https://en.wikipedia.org/wiki/Java_class_file#General_layout
xprintf("Java class file, version %d.%d (Java 1.%d)\n",
(int)peek_be(s+2, 2), (int)peek_be(s, 2), (int)peek_be(s+2, 2)-44);
}
// https://source.android.com/devices/tech/dalvik/dex-format#dex-file-magic
} else if (len>8 && strstart(&s, "dex\n") && !s[3])
xprintf("Android dex file, version %s\n", s);
// https://people.freebsd.org/~kientzle/libarchive/man/cpio.5.txt
// the lengths for cpio are size of header + 9 bytes, since any valid
// cpio archive ends with a record for "TARGET!!!"
else if (len>6 && strstart(&s, "07070")) {
char *cpioformat = "unknown type";
if (*s == '7') cpioformat = "pre-SVR4 or odc";
else if (*s == '1') cpioformat = "SVR4 with no CRC";
else if (*s == '2') cpioformat = "SVR4 with CRC";
xprintf("ASCII cpio archive (%s)\n", cpioformat);
} else if (len>33 && ((magic=peek(&s,2))==0143561 || magic==070707)) {
if (magic == 0143561) printf("byte-swapped ");
xputs("cpio archive");
// tar archive (old, ustar/pax, or gnu)
} else if (len>500 && is_tar_header(s))
xprintf("%s tar archive%s\n", s[257] ? "POSIX" : "old",
(s[262]!=' ' || s[263]!=' ')?"":" (GNU)");
// zip/jar/apk archive, ODF/OOXML document, or such
else if (len>5 && strstart(&s, "PK\03\04")) {
xprintf("Zip archive data");
if (*s) xprintf(", requires at least v%d.%d to extract", *s/10, *s%10);
xputc('\n');
} else if (len>9 && strstart(&s, "7z\xbc\xaf\x27\x1c")) {
xprintf("7-zip archive data");
if (*s || s[1]) xprintf(", version %d.%d", *s, s[1]);
xputc('\n');
} else if (len>4 && strstart(&s, "BZh") && isdigit(*s))
xprintf("bzip2 compressed data, block size = %c00k\n", *s);
else if (len>31 && peek_be(s, 7) == 0xfd377a585a0000UL)
xputs("xz compressed data");
else if (len>10 && strstart(&s, "\x1f\x8b")) xputs("gzip compressed data");
else if (len>32 && !smemcmp(s+1, "\xfa\xed\xfe", 3)) {
int bit = (*s==0xce) ? 32 : 64;
char *what = 0;
xprintf("Mach-O %d-bit ", bit);
if (s[4] == 7) what = (bit==32)?"x86":"x86-";
else if (s[4] == 12) what = "arm";
else if (s[4] == 18) what = "ppc";
if (what) xprintf("%s%s ", what, (bit==32)?"":"64");
else xprintf("(bad arch %d) ", s[4]);
if (s[12] == 1) what = "object";
else if (s[12] == 2) what = "executable";
else if (s[12] == 6) what = "shared library";
else what = NULL;
if (what) xprintf("%s\n", what);
else xprintf("(bad type %d)\n", s[9]);
} else if (len>36 && !smemcmp(s, "OggS\x00\x02", 6)) {
xprintf("Ogg data");
// https://wiki.xiph.org/MIMETypesCodecs
if (!smemcmp(s+28, "CELT ", 8)) xprintf(", celt audio");
else if (!smemcmp(s+28, "CMML ", 8)) xprintf(", cmml text");
else if (!smemcmp(s+28, "BBCD", 5)) xprintf(", dirac video");
else if (!smemcmp(s+28, "\177FLAC", 5)) xprintf(", flac audio");
else if (!smemcmp(s+28, "\x8bJNG\r\n\x1a\n", 8)) xprintf(", jng video");
else if (!smemcmp(s+28, "\x80kate\0\0", 8)) xprintf(", kate text");
else if (!smemcmp(s+28, "OggMIDI", 8)) xprintf(", midi text");
else if (!smemcmp(s+28, "\x8aMNG\r\n\x1a\n", 8)) xprintf(", mng video");
else if (!smemcmp(s+28, "OpusHead", 8)) xprintf(", opus audio");
else if (!smemcmp(s+28, "PCM ", 8)) xprintf(", pcm audio");
else if (!smemcmp(s+28, "\x89PNG\r\n\x1a\n", 8)) xprintf(", png video");
else if (!smemcmp(s+28, "Speex ", 8)) xprintf(", speex audio");
else if (!smemcmp(s+28, "\x80theora", 7)) xprintf(", theora video");
else if (!smemcmp(s+28, "\x01vorbis", 7)) xprintf(", vorbis audio");
else if (!smemcmp(s+28, "YUV4MPEG", 8)) xprintf(", yuv4mpeg video");
xputc('\n');
} else if (len>32 && !smemcmp(s, "RIF", 3) && !smemcmp(s+8, "WAVEfmt ", 8)) {
// https://en.wikipedia.org/wiki/WAV
int le = (s[3] == 'F');
int format = le ? peek_le(s+20, 2) : peek_be(s+20, 2);
int channels = le ? peek_le(s+22, 2) : peek_be(s+22, 2);
int hz = le ? peek_le(s+24, 4) : peek_be(s+24, 4);
int bits = le ? peek_le(s+34, 2) : peek_be(s+34, 2);
xprintf("WAV audio, %s, ", le ? "LE" : "BE");
if (bits) xprintf("%d-bit, ", bits);
if (channels==1||channels==2) xprintf("%s, ",(channels==1)?"mono":"stereo");
else xprintf("%d-channel, ", channels);
xprintf("%d Hz, ", hz);
// See https://tools.ietf.org/html/rfc2361, though there appear to be bugs
// in the RFC. This assumes wikipedia's example files are more correct.
if (format == 0x01) xprintf("PCM");
else if (format == 0x03) xprintf("IEEE float");
else if (format == 0x06) xprintf("A-law");
else if (format == 0x07) xprintf("Вµ-law");
else if (format == 0x11) xprintf("ADPCM");
else if (format == 0x22) xprintf("Truespeech");
else if (format == 0x31) xprintf("GSM");
else if (format == 0x55) xprintf("MP3");
else if (format == 0x70) xprintf("CELP");
else if (format == 0xfffe) xprintf("extensible");
else xprintf("unknown format %d", format);
xputc('\n');
} else if (len>12 && peek_be(s, 4)==0x10000) xputs("TrueType font");
else if (len>12 && !smemcmp(s, "ttcf", 5)) {
xprintf("TrueType font collection, version %d, %d fonts\n",
(int)peek_be(s+4, 2), (int)peek_be(s+8, 4));
// https://docs.microsoft.com/en-us/typography/opentype/spec/otff
} else if (len>12 && strstart(&s, "OTTO")) xputs("OpenType font");
else if (strstart(&s, "BC\xc0\xde")) xputs("LLVM IR bitcode");
else if (strstart(&s,"-----BEGIN CERTIFICATE-----")) xputs("PEM certificate");
// https://msdn.microsoft.com/en-us/library/windows/desktop/ms680547(v=vs.85).aspx
else if (len>0x70 && !smemcmp(s, "MZ", 2) &&
(magic=peek_le(s+0x3c,4))<len-4 && !smemcmp(s+magic, "\x50\x45\0", 4)) {
// Linux kernel images look like PE files.
// https://www.kernel.org/doc/Documentation/arm64/booting.txt
// I've only ever seen LE, 4KiB pages, so ignore flags for now.
if (!smemcmp(s+0x38, "ARMd", 4)) return xputs("Linux arm64 kernel image");
else if (!smemcmp(s+0x202, "HdrS", 4)) {
// https://www.kernel.org/doc/Documentation/x86/boot.txt
unsigned ver_off = peek_le(s+0x20e, 2);
xprintf("Linux x86-64 kernel image");
if ((0x200 + ver_off) < len) {
s += 0x200 + ver_off;
} else {
if (lseek(fd, ver_off - len + 0x200, SEEK_CUR)<0 ||
(len = readall(fd, s, sizeof(toybuf)))<0)
return perror_msg("%s", name);
}
xprintf(", version %s\n", s);
return;
}
xprintf("MS PE32%s executable %s", (peek_le(s+magic+24, 2)==0x20b)?"+":"",
(peek_le(s+magic+22, 2)&0x2000)?"(DLL) ":"");
if (peek_le(s+magic+20, 2)>70) {
char *types[] = {0, "native", "GUI", "console", "OS/2", "driver", "CE",
"EFI", "EFI boot", "EFI runtime", "EFI ROM", "XBOX", 0, "boot"}, *nn;
unsigned type = peek_le(s+magic+92, 2);
nn = (type<ARRAY_LEN(types)) ? types[type] : 0;
xprintf("(%s) ", nn ? : "unknown");
}
xprintf("x86%s\n", (peek_le(s+magic+4, 2)==0x14c) ? "" : "-64");
// https://en.wikipedia.org/wiki/BMP_file_format
} else if (len>0x32 && !smemcmp(s, "BM", 2) && !peek_be(s+6, 4)) {
xprintf("BMP image, %d x %d, %d bpp\n", (int)peek_le(s+18, 4),
(int)peek_le(s+22,4), (int)peek_le(s+28, 2));
// https://github.com/torvalds/linux/blob/master/tools/perf/Documentation/perf.data-file-format.txt
} else if (len>=104 && strstart(&s, "PERFILE2")) xputs("Linux perf data");
// https://android.googlesource.com/platform/system/core/+/master/libsparse/sparse_format.h
else if (len>28 && peek_le(s, 4) == 0xed26ff3a) {
xprintf("Android sparse image v%d.%d, %d %d-byte blocks (%d chunks)\n",
(int)peek_le(s+4, 2), (int)peek_le(s+6, 2), (int)peek_le(s+16, 4),
(int)peek_le(s+12, 4), (int)peek_le(s+20, 4));
// https://android.googlesource.com/platform/system/tools/mkbootimg/+/refs/heads/master/include/bootimg/bootimg.h
} else if (len>1632 && !smemcmp(s, "ANDROID!", 8)) {
xprintf("Android boot image v%d\n", (int)peek_le(s+40, 4));
// https://source.android.com/devices/architecture/dto/partitions
} else if (len>32 && peek_be(s, 4) == 0xd7b7ab1e) {
xprintf("Android DTB/DTBO v%d, %d entries\n", (int)peek_be(s+28, 4),
(int)peek_be(s+16, 4));
// frameworks/base/core/java/com/android/internal/util/BinaryXmlSerializer.java
} else if (len>4 && !smemcmp(s, "ABX", 3)) {
xprintf("Android Binary XML v%d\n", s[3]);
// Text files, including shell scripts.
} else {
char *what = 0;
int i, bytes;
// If shell script, report which interpreter
if (len>3 && strstart(&s, "#!")) {
// Whitespace is allowed between the #! and the interpreter
while (isspace(*s)) s++;
if (strstart(&s, "/usr/bin/env")) while (isspace(*s)) s++;
for (what = s; *s && !isspace(*s); s++);
strcpy(s, " script");
// Distinguish ASCII text, UTF-8 text, or data
} else for (i = 0; i<len; ++i) {
if (!(isprint(s[i]) || isspace(s[i]))) {
unsigned wc;
if ((bytes = utf8towc(&wc, s+i, len-i))>0 && wcwidth(wc)>=0) {
i += bytes-1;
if (!what) what = "UTF-8 text";
} else {
what = "data";
break;
}
}
}
xputs(what ? what : "ASCII text");
}
}
void file_main(void)
{
char **arg;
for (arg = toys.optargs; *arg; ++arg)
TT.max_name_len = maxof(strlen(*arg), TT.max_name_len);
// Can't use loopfiles here because it doesn't call function when can't open
for (arg = toys.optargs; *arg; arg++) {
char *name = *arg, *what = "unknown";
struct stat sb;
int fd = !strcmp(name, "-");
if (!FLAG(b))
xprintf("%s: %*s", name, (int)(TT.max_name_len - strlen(name)), "");
sb.st_size = 0;
if (!fd && (FLAG(L) ? stat : lstat)(name, &sb)) {
xprintf("cannot open: %s\n", strerror(errno));
continue;
}
if (!fd && !FLAG(s) && (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode))) {
sprintf(what = toybuf, "%s special (%u/%u)",
S_ISBLK(sb.st_mode) ? "block" : "character",
dev_major(sb.st_rdev), dev_minor(sb.st_rdev));
} else if (fd || S_ISREG(sb.st_mode)) {
TT.len = sb.st_size;
// This test identifies an empty file we don't have permission to read
if (!fd && !sb.st_size) what = "empty";
else if ((fd = openro(name, O_RDONLY)) != -1) {
do_regular_file(fd, name);
if (fd) close(fd);
continue;
}
} else if (S_ISFIFO(sb.st_mode)) what = "fifo";
else if (S_ISDIR(sb.st_mode)) what = "directory";
else if (S_ISSOCK(sb.st_mode)) what = "socket";
else if (S_ISLNK(sb.st_mode)) {
char *lnk = xreadlink(name);
sprintf(what = toybuf, "%ssymbolic link to %s",
stat(name, &sb) ? "broken " : "", lnk);
free(lnk);
}
xputs(what);
}
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