| /* file.c - describe file type |
| * |
| * Copyright 2016 The Android Open Source Project |
| * |
| * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/file.html |
| |
| USE_FILE(NEWTOY(file, "<1bhLs[!hL]", TOYFLAG_USR|TOYFLAG_BIN)) |
| |
| config FILE |
| bool "file" |
| default y |
| help |
| usage: file [-bhLs] [FILE...] |
| |
| Examine the given files and describe their content types. |
| |
| -b Brief (no filename) |
| -h Don't follow symlinks (default) |
| -L Follow symlinks |
| -s Show block/char device contents |
| */ |
| |
| #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) |
| { |
| int endian = toybuf[5], bits = toybuf[4], i, j, dynamic = 0, stripped = 1, |
| phentsize, phnum, shsize, shnum; |
| int64_t (*elf_int)(void *ptr, unsigned size); |
| char *map = 0; |
| off_t phoff, shoff; |
| |
| printf("ELF "); |
| elf_int = (endian==2) ? peek_be : peek_le; |
| |
| // 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); |
| if (elf_int(toybuf+36+12*(bits==2), 4) & 0x8000) printf(" (fdpic)"); |
| printf(", "); |
| |
| // "64-bit" |
| if (bits == 1) printf("32-bit "); |
| else if (bits == 2) printf("64-bit "); |
| else { |
| printf("(bad class %d) ", bits); |
| bits = 0; |
| } |
| |
| // "LSB" |
| if (endian == 1) printf("LSB "); |
| else if (endian == 2) printf("MSB "); |
| else { |
| printf("(bad endian %d) \n", endian); |
| endian = 0; |
| } |
| |
| // "x86". |
| printf("%s", elf_arch_name(elf_int(toybuf+18, 2))); |
| |
| bits--; |
| // If what we've seen so far doesn't seem consistent, bail. |
| if (!((bits&1)==bits && endian)) { |
| printf(", corrupt?\n"); |
| return; |
| } |
| |
| // 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))) |
| 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(", corrupt phentsize %d?", phentsize); |
| 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))) |
| goto bad; |
| |
| // We need to read the phdrs for dynamic vs static. |
| // (Note: fields got reordered for 64 bit) |
| if (phoff+phnum*phentsize>TT.len) goto bad; |
| for (i = 0; i<phnum; i++) { |
| char *phdr = map+phoff+i*phentsize; |
| int p_type = elf_int(phdr, 4); |
| long long p_offset, p_filesz; |
| |
| if (p_type==2 /*PT_DYNAMIC*/) dynamic = 1; |
| if (p_type!=3 /*PT_INTERP*/ && p_type!=4 /*PT_NOTE*/) continue; |
| |
| j = bits+1; |
| p_offset = elf_int(phdr+4*j, 4*j); |
| p_filesz = elf_int(phdr+16*j, 4*j); |
| |
| if (p_type==3 /*PT_INTERP*/) { |
| if (p_offset+p_filesz>TT.len) goto bad; |
| 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 we prefer to check here. |
| // (Note: fields got reordered for 64 bit) |
| if (shoff+i*shnum>TT.len) goto bad; |
| for (i = 0; i<shnum; i++) { |
| char *shdr = map+shoff+i*shsize; |
| int sh_type = elf_int(shdr+4, 4); |
| long sh_offset = elf_int(shdr+8+8*(bits+1), 4*(bits+1)); |
| int sh_size = elf_int(shdr+8+12*(bits+1), 4); |
| |
| 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 (sh_offset+sh_size>TT.len) 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); |
| |
| // Does the claimed size of this note actually fit in the section? |
| if (notesz > sh_size) goto bad; |
| |
| if (n_namesz==4 && !memcmp(note+12, "GNU", 4)) { |
| if (n_type==3 /*NT_GNU_BUILD_ID*/) { |
| printf(", BuildID="); |
| for (j = 0; j < n_descsz; ++j) printf("%02x", note[16 + j]); |
| } |
| } else if (n_namesz==8 && !memcmp(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 != MAP_FAILED) munmap(map, TT.len); |
| } |
| |
| static void do_regular_file(int fd, char *name) |
| { |
| char *s; |
| int len, magic; |
| |
| // zero through elf shnum, just in case |
| memset(toybuf, 0, 80); |
| if ((len = readall(fd, s = toybuf, sizeof(toybuf)))<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 (len>=8 && strstart(&s, "!<arch>\n")) xputs("ar archive"); |
| 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]]; |
| if (!c) c = "unknown"; |
| |
| xprintf(", %d x %d, %d-bit/%s, %sinterlaced", (int)peek_be(s, 4), |
| (int)peek_be(s+4, 4), s[8], c, 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, %d x %d\n", |
| (int)peek_le(s, 2), (int)peek_le(s+8, 2)); |
| |
| // TODO: parsing JPEG for width/height is harder than GIF or PNG. |
| else if (len>32 && !memcmp(toybuf, "\xff\xd8", 2)) xputs("JPEG image data"); |
| |
| // https://en.wikipedia.org/wiki/Java_class_file#General_layout |
| else if (len>8 && strstart(&s, "\xca\xfe\xba\xbe")) |
| 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] == 0) |
| 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>85 && strstart(&s, "07070")) { |
| char *cpioformat = "unknown type"; |
| |
| if (toybuf[5] == '7') cpioformat = "pre-SVR4 or odc"; |
| else if (toybuf[5] == '1') cpioformat = "SVR4 with no CRC"; |
| else if (toybuf[5] == '2') cpioformat = "SVR4 with CRC"; |
| xprintf("ASCII cpio archive (%s)\n", cpioformat); |
| } else if (len>33 && (magic=peek(&s,2), magic==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", |
| strncmp(s+262," ",2)?"":" (GNU)"); |
| // zip/jar/apk archive, ODF/OOXML document, or such |
| else if (len>5 && strstart(&s, "PK\03\04")) { |
| int ver = toybuf[4]; |
| |
| xprintf("Zip archive data"); |
| if (ver) xprintf(", requires at least v%d.%d to extract", ver/10, ver%10); |
| xputc('\n'); |
| } else if (len>9 && strstart(&s, "7z\xbc\xaf\x27\x1c")) { |
| int ver = toybuf[6]*10+toybuf[7]; |
| |
| xprintf("7-zip archive data"); |
| if (ver) xprintf(", version %d.%d", ver/10, ver%10); |
| 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 && !memcmp(s+1, "\xfa\xed\xfe", 3)) { |
| int bit = s[0]=='\xce'?32:64; |
| char *what; |
| |
| 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"; |
| else what = NULL; |
| 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 && !memcmp(s, "OggS\x00\x02", 6)) { |
| xprintf("Ogg data"); |
| // https://wiki.xiph.org/MIMETypesCodecs |
| if (!memcmp(s+28, "CELT ", 8)) xprintf(", celt audio"); |
| else if (!memcmp(s+28, "CMML ", 8)) xprintf(", cmml text"); |
| else if (!memcmp(s+28, "BBCD\0", 5)) xprintf(", dirac video"); |
| else if (!memcmp(s+28, "\177FLAC", 5)) xprintf(", flac audio"); |
| else if (!memcmp(s+28, "\x8bJNG\r\n\x1a\n", 8)) xprintf(", jng video"); |
| else if (!memcmp(s+28, "\x80kate\0\0\0", 8)) xprintf(", kate text"); |
| else if (!memcmp(s+28, "OggMIDI\0", 8)) xprintf(", midi text"); |
| else if (!memcmp(s+28, "\x8aMNG\r\n\x1a\n", 8)) xprintf(", mng video"); |
| else if (!memcmp(s+28, "OpusHead", 8)) xprintf(", opus audio"); |
| else if (!memcmp(s+28, "PCM ", 8)) xprintf(", pcm audio"); |
| else if (!memcmp(s+28, "\x89PNG\r\n\x1a\n", 8)) xprintf(", png video"); |
| else if (!memcmp(s+28, "Speex ", 8)) xprintf(", speex audio"); |
| else if (!memcmp(s+28, "\x80theora", 7)) xprintf(", theora video"); |
| else if (!memcmp(s+28, "\x01vorbis", 7)) xprintf(", vorbis audio"); |
| else if (!memcmp(s+28, "YUV4MPEG", 8)) xprintf(", yuv4mpeg video"); |
| xputc('\n'); |
| } else if (len>32 && !memcmp(s, "RIF", 3) && !memcmp(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 != 0) 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("µ-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 && !memcmp(s, "\x00\x01\x00\x00", 4)) { |
| xputs("TrueType font"); |
| } else if (len>12 && !memcmp(s, "ttcf\x00", 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 && !memcmp(s, "OTTO", 4)) { |
| xputs("OpenType font"); |
| } else if (len>4 && !memcmp(s, "BC\xc0\xde", 4)) { |
| 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 && !memcmp(s, "MZ", 2) && |
| (magic=peek_le(s+0x3c,4))<len-4 && !memcmp(s+magic, "\x50\x45\0\0", 4)) { |
| 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"}; |
| int type = peek_le(s+magic+92, 2); |
| char *name = (type>0 && type<ARRAY_LEN(types))?types[type]:0; |
| |
| xprintf("(%s) ", name?name:"unknown"); |
| } |
| xprintf("%s\n", (peek_le(s+magic+4, 2)==0x14c)?"x86":"x86-64"); |
| |
| // https://en.wikipedia.org/wiki/BMP_file_format |
| } else if (len > 0x32 && !memcmp(s, "BM", 2) && !memcmp(s+6, "\0\0\0\0", 4)) { |
| int w = peek_le(s+0x12,4), h = peek_le(s+0x16,4), bpp = peek_le(s+0x1c,2); |
| |
| xprintf("BMP image, %d x %d, %d bpp\n", w, h, bpp); |
| |
| // https://github.com/torvalds/linux/blob/master/tools/perf/Documentation/perf.data-file-format.txt |
| } else if (len>=104 && !memcmp(s, "PERFILE2", 8)) { |
| 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 && !memcmp(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)); |
| |
| } 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-toybuf)<len && !isspace(*s); s++); |
| strcpy(s, " script"); |
| |
| // Distinguish ASCII text, UTF-8 text, or data |
| } else for (i = 0; i<len; ++i) { |
| if (!(isprint(toybuf[i]) || isspace(toybuf[i]))) { |
| wchar_t 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) { |
| int name_len = strlen(*arg); |
| |
| if (name_len > TT.max_name_len) TT.max_name_len = 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)) { |
| 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); |
| } else xprintf("cannot open: %s\n", strerror(errno)); |
| } |
| } |