vm_tools/garcon/mime_types_parser_test.cc

// Copyright 2018 The ChromiumOS Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "vm_tools/garcon/mime_types_parser.h"

#include <map>
#include <string>
#include <vector>

#include <base/base64.h>
#include <base/check.h>
#include <base/files/file_path.h>
#include <base/files/file_util.h>
#include <base/files/scoped_temp_dir.h>
#include <gtest/gtest.h>

namespace vm_tools {
namespace garcon {

namespace {

// Test mime.cache files are generated using a process such as:
// mkdir -p /tmp/mimetest/packages
// cat <<EOF >> /tmp/mimetest/packages/application-x-foobar.xml
// <?xml version="1.0" encoding="UTF-8"?>
// <mime-info xmlns="http://www.freedesktop.org/standards/shared-mime-info">
//   <mime-type type="x/no-dot"><glob pattern="~"/></mime-type>
//   <mime-type type="application/pdf"><glob pattern="*.pdf"/></mime-type>
//   <mime-type type="text/plain"><glob pattern="*.txt"/></mime-type>
//   <mime-type type="text/plain"><glob pattern="*.doc"/></mime-type>
//   <mime-type type="x/ignore"><glob pattern="*.foo" weight="60"/></mime-type>
//   <mime-type type="x/foo"><glob pattern="*.foo" weight="80"/></mime-type>
//   <mime-type type="text/plain"><glob pattern="*.foo"/></mime-type>
//   <mime-type type="x/smile"><glob pattern="*.🙂🤩"/></mime-type>
// </mime-info>
// EOF
// update-mime-database /tmp/mimetest
// base64 -w72 /tmp/mimetest/mime.cache
// See https://wiki.archlinux.org/title/XDG_MIME_Applications

static constexpr const char kTestMimeCacheB64[] =
    "AAEAAgAAAHQAAAB4AAAAfAAAAIwAAAHMAAAB0AAAAdwAAAHgAAAB5AAAAehhcHBsaWNhdGlv"
    "bi9wZGYAeC9zbWlsZQB4L2lnbm9yZQAAAAB0ZXh0L3BsYWluAAB4L2ZvbwAAAH4AAAB4L25v"
    "LWRvdAAAAAAAAAAAAAAAAAAAAAEAAABkAAAAaAAAADIAAAAFAAAAlAAAAGMAAAABAAAA0AAA"
    "AGYAAAABAAAA3AAAAG8AAAABAAAA6AAAAHQAAAABAAAA9AAB+SkAAAABAAABAAAAAG8AAAAB"
    "AAABDAAAAGQAAAABAAABGAAAAG8AAAABAAABJAAAAHgAAAABAAABMAAB9kIAAAABAAABPAAA"
    "AGQAAAABAAABSAAAAHAAAAABAAABVAAAAGYAAAABAAABYAAAAHQAAAABAAABbAAAAC4AAAAB"
    "AAABeAAAAC4AAAABAAABhAAAAC4AAAABAAABkAAAAC4AAAADAAABnAAAAC4AAAABAAABwAAA"
    "AAAAAAA8AAAAMgAAAAAAAABQAAAAMgAAAAAAAAAsAAAAMgAAAAAAAABEAAAAPAAAAAAAAABc"
    "AAAAUAAAAAAAAABQAAAAMgAAAAAAAABQAAAAMgAAAAAAAAAAAAAAAAAAAdwAAAAAAAAAAAAA"
    "AAAAAAAGAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";

class MimeTypesParserTest : public ::testing::Test {
 public:
  MimeTypesParserTest() {
    CHECK(temp_dir_.CreateUniqueTempDir());
    mime_types_path_ = temp_dir_.GetPath().Append("mime.types");
  }
  MimeTypesParserTest(const MimeTypesParserTest&) = delete;
  MimeTypesParserTest& operator=(const MimeTypesParserTest&) = delete;

  ~MimeTypesParserTest() override = default;

  void WriteContents(const std::string& file_contents) {
    EXPECT_TRUE(base::WriteFile(mime_types_path_, file_contents));
  }

  // Ensures that parsing fails when mime.cache file is modified such that
  // |buf[pos] = c|.
  void InvalidIf(std::string buf, int pos, char c) {
    std::string s(buf);
    s[pos] = c;
    WriteContents(s);
    MimeTypeMap map;
    EXPECT_FALSE(ParseMimeTypes(TempFilePath(), &map));
  }

  std::string TempFilePath() const { return mime_types_path_.value(); }

 private:
  base::ScopedTempDir temp_dir_;
  base::FilePath mime_types_path_;
};

}  // namespace

TEST_F(MimeTypesParserTest, NonExistentFileFails) {
  MimeTypeMap map;
  EXPECT_FALSE(ParseMimeTypes("/invalid/filepath/foo", &map));
}

TEST_F(MimeTypesParserTest, ValidResult) {
  MimeTypeMap map;
  std::string buf;
  base::Base64Decode(kTestMimeCacheB64, &buf);
  WriteContents(buf);
  EXPECT_TRUE(ParseMimeTypes(TempFilePath(), &map));
  MimeTypeMap expected = {
      {"pdf", "application/pdf"}, {"txt", "text/plain"}, {"doc", "text/plain"},
      {"foo", "x/foo"},           {"🙂🤩", "x/smile"},
  };
  EXPECT_EQ(map, expected);
}

TEST_F(MimeTypesParserTest, Empty) {
  MimeTypeMap map;
  WriteContents("");
  EXPECT_FALSE(ParseMimeTypes(TempFilePath(), &map));
}

// xxd /tmp/mimetest/mime.cache
// 00000000: 0001 0002 0000 0074 0000 0078 0000 007c  .......t...x...|
// 00000010: 0000 008c 0000 01cc 0000 01d0 0000 01dc  ................
// 00000020: 0000 01e0 0000 01e4 0000 01e8 6170 706c  ............appl
// 00000030: 6963 6174 696f 6e2f 7064 6600 782f 736d  ication/pdf.x/sm
// 00000040: 696c 6500 782f 6967 6e6f 7265 0000 0000  ile.x/ignore....
// 00000050: 7465 7874 2f70 6c61 696e 0000 782f 666f  text/plain..x/fo
// 00000060: 6f00 0000 7e00 0000 782f 6e6f 2d64 6f74  o...~...x/no-dot
// 00000070: 0000 0000 0000 0000 0000 0000 0000 0001  ................
// 00000080: 0000 0064 0000 0068 0000 0032 0000 0005  ...d...h...2....
// 00000090: 0000 0094 0000 0063 0000 0001 0000 00d0  .......c........
// 000000a0: 0000 0066 0000 0001 0000 00dc 0000 006f  ...f...........o
// 000000b0: 0000 0001 0000 00e8 0000 0074 0000 0001  ...........t....
// 000000c0: 0000 00f4 0001 f929 0000 0001 0000 0100  .......)........
// 000000d0: 0000 006f 0000 0001 0000 010c 0000 0064  ...o...........d
// 000000e0: 0000 0001 0000 0118 0000 006f 0000 0001  ...........o....
// 000000f0: 0000 0124 0000 0078 0000 0001 0000 0130  ...$...x.......0
// 00000100: 0001 f642 0000 0001 0000 013c 0000 0064  ...B.......<...d
// 00000110: 0000 0001 0000 0148 0000 0070 0000 0001  .......H...p....
// 00000120: 0000 0154 0000 0066 0000 0001 0000 0160  ...T...f.......`
// 00000130: 0000 0074 0000 0001 0000 016c 0000 002e  ...t.......l....
// 00000140: 0000 0001 0000 0178 0000 002e 0000 0001  .......x........
// 00000150: 0000 0184 0000 002e 0000 0001 0000 0190  ................
// 00000160: 0000 002e 0000 0003 0000 019c 0000 002e  ................
// 00000170: 0000 0001 0000 01c0 0000 0000 0000 003c  ...............<
// 00000180: 0000 0032 0000 0000 0000 0050 0000 0032  ...2.......P...2
// 00000190: 0000 0000 0000 002c 0000 0032 0000 0000  .......,...2....
// 000001a0: 0000 0044 0000 003c 0000 0000 0000 005c  ...D...<.......\
// 000001b0: 0000 0050 0000 0000 0000 0050 0000 0032  ...P.......P...2
// 000001c0: 0000 0000 0000 0050 0000 0032 0000 0000  .......P...2....
// 000001d0: 0000 0000 0000 0000 0000 01dc 0000 0000  ................
// 000001e0: 0000 0000 0000 0000 0000 0006 0000 0000  ................
// 000001f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
// 00000200: 0000 0000
TEST_F(MimeTypesParserTest, Invalid) {
  std::string buf;
  base::Base64Decode(kTestMimeCacheB64, &buf);
  // ALIAS_LIST_OFFSET is uint32 at byte 4 = 0x74.
  // Alias list offset inside header.
  InvalidIf(buf, 7, 0xa);
  // Alias list offset larger than file size.
  InvalidIf(buf, 6, 0xff);
  // Not null beore alias list.
  InvalidIf(buf, 0x74 - 1, 'X');
  // Misaligned offset for REVERSE_SUFFIX_TREE_OFFSET.
  InvalidIf(buf, 0x13, 0x7a);
  // N_ROOTS > kMaxUnicode (0x10ffff).
  InvalidIf(buf, 0x8d, 0x20);
  InvalidIf(buf, 0xd5, 0x20);
  // Node C > kMaxUnicode (0x10ffff).
  InvalidIf(buf, 0x95, 0x20);
  // Node N_CHILDREN > kMaxUnicode (0x10ffff).
  InvalidIf(buf, 0x99, 0x20);
  // Node FIRST_CHILD_OFFSET below tree offset.
  InvalidIf(buf, 0x9f, 0x10);
  InvalidIf(buf, 0xdb, 0x20);
  // Node FIRST_CHILD_OFFSET beyond file size.
  InvalidIf(buf, 0x9e, 0x20);
  InvalidIf(buf, 0xda, 0x20);
  // Mime type offset below header.
  InvalidIf(buf, 0x18b, 0x10);
  // Mime type offset above alias list.
  InvalidIf(buf, 0x18b, 0x74);
}

}  // namespace garcon
}  // namespace vm_tools