mirror of
https://github.com/jart/cosmopolitan.git
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f4f4caab0e
I wanted a tiny scriptable meltdown proof way to run userspace programs and visualize how program execution impacts memory. It helps to explain how things like Actually Portable Executable works. It can show you how the GCC generated code is going about manipulating matrices and more. I didn't feel fully comfortable with Qemu and Bochs because I'm not smart enough to understand them. I wanted something like gVisor but with much stronger levels of assurances. I wanted a single binary that'll run, on all major operating systems with an embedded GPL barrier ZIP filesystem that is tiny enough to transpile to JavaScript and run in browsers too. https://justine.storage.googleapis.com/emulator625.mp4
325 lines
13 KiB
C
325 lines
13 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ This program is free software; you can redistribute it and/or modify │
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│ it under the terms of the GNU General Public License as published by │
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│ the Free Software Foundation; version 2 of the License. │
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│ │
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│ This program is distributed in the hope that it will be useful, but │
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│ WITHOUT ANY WARRANTY; without even the implied warranty of │
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│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
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│ General Public License for more details. │
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│ │
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│ You should have received a copy of the GNU General Public License │
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│ along with this program; if not, write to the Free Software │
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│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
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│ 02110-1301 USA │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/bits/bits.h"
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#include "libc/bits/safemacros.h"
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#include "libc/calls/calls.h"
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#include "libc/calls/struct/stat.h"
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#include "libc/conv/conv.h"
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#include "libc/log/check.h"
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#include "libc/mem/mem.h"
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#include "libc/nexgen32e/crc32.h"
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#include "libc/nt/struct/filetime.h"
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#include "libc/runtime/gc.h"
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#include "libc/stdio/stdio.h"
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#include "libc/str/str.h"
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#include "libc/sysv/consts/map.h"
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#include "libc/sysv/consts/o.h"
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#include "libc/sysv/consts/prot.h"
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#include "libc/x/x.h"
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#include "libc/zip.h"
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#include "tool/decode/lib/asmcodegen.h"
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#include "tool/decode/lib/disassemblehex.h"
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#include "tool/decode/lib/flagger.h"
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#include "tool/decode/lib/idname.h"
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#include "tool/decode/lib/ntfileflagnames.h"
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#include "tool/decode/lib/titlegen.h"
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#include "tool/decode/lib/zipnames.h"
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/**
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* @fileoverview Zip File Disassembler.
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*/
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nodiscard char *formatdosdate(uint16_t dosdate) {
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return xasprintf("%04u-%02u-%02u", ((dosdate >> 9) & 0b1111111) + 1980,
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(dosdate >> 5) & 0b1111, dosdate & 0b11111);
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}
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nodiscard char *formatdostime(uint16_t dostime) {
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return xasprintf("%02u:%02u:%02u", (dostime >> 11) & 0b11111,
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(dostime >> 5) & 0b111111, (dostime << 1) & 0b111110);
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}
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void advancepos(uint8_t *map, size_t *pos, size_t off) {
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CHECK_GE(off, *pos);
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if (off > *pos) {
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printf("\n/\t<%s>\n", "LIMBO");
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disassemblehex(&map[*pos], off - *pos, stdout);
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printf("/\t</%s>\n", "LIMBO");
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}
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*pos = off;
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}
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void showgeneralflag(uint16_t generalflag) {
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puts("\
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/ ┌─utf8\n\
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/ │ ┌─strong encryption\n\
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/ │ │┌─compressed patch data\n\
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/ │ ││ ┌─crc and size go after file content\n\
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/ │ ││ │┌─{normal,max,fast,superfast}\n\
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/ │ ││ ││ ┌─encrypted\n\
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/ rrrr│uuuu││r│├┐│");
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show(".short", format(b1, "0b%016b", generalflag), "generalflag");
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}
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void showtimestamp(uint16_t time, uint16_t date) {
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show(".short", format(b1, "%#04hx", time),
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gc(xasprintf("%s (%s)", "lastmodifiedtime", gc(formatdostime(time)))));
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show(".short", format(b1, "%#04hx", date),
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gc(xasprintf("%s (%s)", "lastmodifieddate", gc(formatdosdate(date)))));
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}
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void showcompressmethod(uint16_t compressmethod) {
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show(".short",
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firstnonnull(findnamebyid(kZipCompressionNames, compressmethod),
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format(b1, "%hu", compressmethod)),
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"compressionmethod");
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}
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void showextrantfs(uint8_t *ntfs) {
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struct timespec mtime, atime, ctime;
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mtime = filetimetotimespec(
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(struct NtFileTime){read32le(ntfs + 8), read32le(ntfs + 12)});
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atime = filetimetotimespec(
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(struct NtFileTime){read32le(ntfs + 16), read32le(ntfs + 20)});
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ctime = filetimetotimespec(
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(struct NtFileTime){read32le(ntfs + 24), read32le(ntfs + 30)});
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show(".long", gc(xasprintf("%d", read32le(ntfs))), "ntfs reserved");
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show(".short", gc(xasprintf("0x%04x", read16le(ntfs + 4))),
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"ntfs attribute tag value #1");
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show(".short", gc(xasprintf("%hu", read16le(ntfs + 6))),
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"ntfs attribute tag size");
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show(".quad", gc(xasprintf("%lu", read64le(ntfs + 8))),
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gc(xasprintf("%s (%s)", "ntfs last modified time",
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gc(xiso8601(&mtime)))));
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show(".quad", gc(xasprintf("%lu", read64le(ntfs + 16))),
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gc(xasprintf("%s (%s)", "ntfs last access time", gc(xiso8601(&atime)))));
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show(".quad", gc(xasprintf("%lu", read64le(ntfs + 24))),
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gc(xasprintf("%s (%s)", "ntfs creation time", gc(xiso8601(&ctime)))));
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}
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void showextra(uint8_t *extra) {
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switch (ZIP_EXTRA_HEADERID(extra)) {
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case kZipExtraNtfs:
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showextrantfs(ZIP_EXTRA_CONTENT(extra));
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break;
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case kZipExtraZip64:
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/* TODO */
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default:
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disassemblehex(ZIP_EXTRA_CONTENT(extra), ZIP_EXTRA_CONTENTSIZE(extra),
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stdout);
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break;
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}
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}
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void showexternalattributes(uint8_t *cf) {
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uint32_t ea;
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ea = ZIP_CFILE_EXTERNALATTRIBUTES(cf);
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if (ZIP_CFILE_FILEATTRCOMPAT(cf) == kZipOsUnix) {
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show(".short", RecreateFlags(kNtFileFlagNames, ea & 0xffff),
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"dos file flags");
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show(".short", format(b1, "%#o", ea >> 16), "st_mode");
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} else {
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show(".long", RecreateFlags(kNtFileFlagNames, ea), "externalattributes");
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}
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}
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void showextras(uint8_t *extras, uint16_t extrassize) {
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int i;
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bool first;
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uint8_t *p, *pe;
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if (extrassize) {
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first = true;
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for (p = extras, pe = extras + extrassize, i = 0; p < pe;
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p += ZIP_EXTRA_SIZE(p), ++i) {
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show(".short",
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firstnonnull(findnamebyid(kZipExtraNames, ZIP_EXTRA_HEADERID(p)),
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gc(xasprintf("0x%04hx", ZIP_EXTRA_HEADERID(p)))),
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gc(xasprintf("%s[%d].%s", "extras", i, "headerid")));
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show(".short", gc(xasprintf("%df-%df", (i + 2) * 10, (i + 1) * 10)),
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gc(xasprintf("%s[%d].%s (%hd %s)", "extras", i, "contentsize",
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ZIP_EXTRA_CONTENTSIZE(p), "bytes")));
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if (first) {
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first = false;
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printf("%d:", (i + 1) * 10);
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}
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showextra(p);
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printf("%d:", (i + 2) * 10);
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}
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}
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putchar('\n');
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}
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void showlocalfileheader(uint8_t *lf, uint16_t idx) {
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printf("\n/\t%s #%hu (%zu %s)\n", "local file", idx + 1,
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ZIP_LFILE_HDRSIZE(lf), "bytes");
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show(".ascii", format(b1, "%`'.*s", 4, lf), "magic");
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show(".byte",
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firstnonnull(findnamebyid(kZipEraNames, ZIP_LFILE_VERSIONNEED(lf)),
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gc(xasprintf("%d", ZIP_LFILE_VERSIONNEED(lf)))),
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"pkzip version need");
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show(".byte",
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firstnonnull(findnamebyid(kZipOsNames, ZIP_LFILE_OSNEED(lf)),
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gc(xasprintf("%d", ZIP_LFILE_OSNEED(lf)))),
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"os need");
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showgeneralflag(ZIP_LFILE_GENERALFLAG(lf));
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showcompressmethod(ZIP_LFILE_COMPRESSIONMETHOD(lf));
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showtimestamp(ZIP_LFILE_LASTMODIFIEDTIME(lf), ZIP_LFILE_LASTMODIFIEDDATE(lf));
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show(".long", format(b1, "%#x", ZIP_LFILE_CRC32(lf)),
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gc(xasprintf(
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"%s (%#x)", "crc32z",
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crc32_z(0, ZIP_LFILE_CONTENT(lf), ZIP_LFILE_COMPRESSEDSIZE(lf)))));
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show(".long", "3f-2f",
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format(b1, "%s (%u %s)", "compressedsize", ZIP_LFILE_COMPRESSEDSIZE(lf),
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"bytes"));
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show(".long", format(b1, "%u", ZIP_LFILE_UNCOMPRESSEDSIZE(lf)),
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"uncompressedsize");
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show(".short", "1f-0f",
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format(b1, "%s (%hu %s)", "namesize", ZIP_LFILE_NAMESIZE(lf), "bytes"));
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show(
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".short", "2f-1f",
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format(b1, "%s (%hu %s)", "extrasize", ZIP_LFILE_EXTRASIZE(lf), "bytes"));
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printf("0:");
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show(".ascii",
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format(b1, "%`'s",
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gc(strndup(ZIP_LFILE_NAME(lf), ZIP_LFILE_NAMESIZE(lf)))),
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"name");
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printf("1:");
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showextras(ZIP_LFILE_EXTRA(lf), ZIP_LFILE_EXTRASIZE(lf));
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printf("2:");
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disassemblehex(ZIP_LFILE_CONTENT(lf), ZIP_LFILE_COMPRESSEDSIZE(lf), stdout);
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printf("3:\n");
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}
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void showcentralfileheader(uint8_t *cf) {
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printf("\n/\t%s (%zu %s)\n", "central directory file header",
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ZIP_CFILE_HDRSIZE(cf), "bytes");
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show(".ascii", format(b1, "%`'.*s", 4, cf), "magic");
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show(".byte", gc(xasprintf("%d", ZIP_CFILE_VERSIONMADE(cf))), "version made");
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show(".byte",
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firstnonnull(findnamebyid(kZipOsNames, ZIP_CFILE_FILEATTRCOMPAT(cf)),
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gc(xasprintf("%d", ZIP_CFILE_FILEATTRCOMPAT(cf)))),
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"file attr compat");
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show(".byte",
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firstnonnull(findnamebyid(kZipEraNames, ZIP_CFILE_VERSIONNEED(cf)),
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gc(xasprintf("%d", ZIP_CFILE_VERSIONNEED(cf)))),
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"pkzip version need");
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show(".byte",
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firstnonnull(findnamebyid(kZipOsNames, ZIP_CFILE_OSNEED(cf)),
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gc(xasprintf("%d", ZIP_CFILE_OSNEED(cf)))),
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"os need");
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showgeneralflag(ZIP_CFILE_GENERALFLAG(cf));
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showcompressmethod(ZIP_CFILE_COMPRESSIONMETHOD(cf));
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showtimestamp(ZIP_CFILE_LASTMODIFIEDTIME(cf), ZIP_CFILE_LASTMODIFIEDDATE(cf));
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show(".long", format(b1, "%#x", ZIP_CFILE_CRC32(cf)), "crc32z");
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show(".long", format(b1, "%u", ZIP_CFILE_COMPRESSEDSIZE(cf)),
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"compressedsize");
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show(".long", format(b1, "%u", ZIP_CFILE_UNCOMPRESSEDSIZE(cf)),
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"uncompressedsize");
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show(".short", "1f-0f",
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format(b1, "%s (%hu %s)", "namesize", ZIP_CFILE_NAMESIZE(cf), "bytes"));
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show(
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".short", "2f-1f",
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format(b1, "%s (%hu %s)", "extrasize", ZIP_CFILE_EXTRASIZE(cf), "bytes"));
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show(".short", "3f-2f",
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format(b1, "%s (%hu %s)", "commentsize", ZIP_CFILE_COMMENTSIZE(cf),
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"bytes"));
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show(".short", format(b1, "%hu", ZIP_CFILE_DISK(cf)), "disk");
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show(".short",
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RecreateFlags(kZipIattrNames, ZIP_CFILE_INTERNALATTRIBUTES(cf)),
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"internalattributes");
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showexternalattributes(cf);
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show(".long", format(b1, "%u", ZIP_CFILE_OFFSET(cf)), "lfile hdr offset");
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printf("0:");
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show(".ascii",
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format(b1, "%`'s",
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gc(strndup(ZIP_CFILE_NAME(cf), ZIP_CFILE_NAMESIZE(cf)))),
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"name");
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printf("1:");
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showextras(ZIP_CFILE_EXTRA(cf), ZIP_CFILE_EXTRASIZE(cf));
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printf("2:");
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disassemblehex(ZIP_CFILE_COMMENT(cf), ZIP_CFILE_COMMENTSIZE(cf), stdout);
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printf("3:\n");
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}
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void showcentraldirheader(uint8_t *cd) {
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printf("\n/\t%s (%zu %s)\n", "end of central directory header",
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ZIP_CDIR_HDRSIZE(cd), "bytes");
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show(".ascii", format(b1, "%`'.*s", 4, cd), "magic");
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show(".short", format(b1, "%hd", ZIP_CDIR_DISK(cd)), "disk");
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show(".short", format(b1, "%hd", ZIP_CDIR_STARTINGDISK(cd)), "startingdisk");
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show(".short", format(b1, "%hu", ZIP_CDIR_RECORDSONDISK(cd)),
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"recordsondisk");
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show(".short", format(b1, "%hu", ZIP_CDIR_RECORDS(cd)), "records");
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show(".long", format(b1, "%u", ZIP_CDIR_SIZE(cd)), "size");
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show(".long", format(b1, "%u", ZIP_CDIR_OFFSET(cd)), "cfile hdrs offset");
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show(".short", "1f-0f",
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format(b1, "%s (%hu %s)", "commentsize", ZIP_CDIR_COMMENTSIZE(cd),
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"bytes"));
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printf("0:");
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disassemblehex(ZIP_CDIR_COMMENT(cd), ZIP_CDIR_COMMENTSIZE(cd), stdout);
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printf("1:\n");
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}
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void disassemblezip(uint8_t *map, size_t mapsize) {
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size_t pos;
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uint16_t i;
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static int records;
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uint8_t *cd, *cf, *lf;
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CHECK_NOTNULL((cd = zipfindcentraldir(map, mapsize)));
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pos = 0;
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records = ZIP_CDIR_RECORDS(cd);
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for (i = 0, cf = map + ZIP_CDIR_OFFSET(cd); i < records;
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++i, cf += ZIP_CFILE_HDRSIZE(cf)) {
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lf = map + ZIP_CFILE_OFFSET(cf);
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CHECK_EQ(kZipLfileHdrMagic, ZIP_LFILE_MAGIC(lf));
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advancepos(map, &pos, lf - map);
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showlocalfileheader(lf, i);
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pos = (lf - map) + ZIP_LFILE_SIZE(lf);
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}
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for (i = 0, cf = map + ZIP_CDIR_OFFSET(cd); i < records;
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++i, cf += ZIP_CFILE_HDRSIZE(cf)) {
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CHECK_EQ(kZipCfileHdrMagic, ZIP_CFILE_MAGIC(cf));
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advancepos(map, &pos, cf - map);
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showcentralfileheader(cf);
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pos = (cf - map) + ZIP_CFILE_HDRSIZE(cf);
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}
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advancepos(map, &pos, cd - map);
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showcentraldirheader(cd);
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pos = (cd - map) + ZIP_CDIR_HDRSIZE(cd);
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advancepos(map, &pos, mapsize);
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}
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int main(int argc, char *argv[]) {
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int fd;
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uint8_t *map;
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struct stat st;
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CHECK_EQ(2, argc);
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CHECK_NE(-1, (fd = open(argv[1], O_RDONLY)));
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CHECK_NE(-1, fstat(fd, &st));
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CHECK_GE(st.st_size, kZipCdirHdrMinSize);
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CHECK_NE(MAP_FAILED,
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(map = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0)));
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showtitle("αcτµαlly pδrταblε εxεcµταblε", "tool/decode/zip",
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basename(argv[1]), NULL, &kModelineAsm);
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disassemblezip(map, st.st_size);
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CHECK_NE(-1, munmap(map, st.st_size));
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CHECK_NE(-1, close(fd));
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return 0;
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}
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