delta_diff_generator.cc revision f1cbe1783dd025bd7243a8df12f20548196cc023 
1// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "update_engine/payload_generator/delta_diff_generator.h"
6
7#include <errno.h>
8#include <fcntl.h>
9#include <inttypes.h>
10#include <sys/stat.h>
11#include <sys/types.h>
12
13#include <algorithm>
14#include <map>
15#include <memory>
16#include <string>
17#include <utility>
18#include <vector>
19
20#include <base/files/file_path.h>
21#include <base/files/file_util.h>
22#include <base/logging.h>
23#include <base/strings/stringprintf.h>
24#include <base/strings/string_number_conversions.h>
25#include <base/strings/string_util.h>
26#include <bzlib.h>
27
28#include "update_engine/bzip.h"
29#include "update_engine/delta_performer.h"
30#include "update_engine/file_writer.h"
31#include "update_engine/omaha_hash_calculator.h"
32#include "update_engine/payload_constants.h"
33#include "update_engine/payload_generator/extent_mapper.h"
34#include "update_engine/payload_generator/filesystem_iterator.h"
35#include "update_engine/payload_generator/full_update_generator.h"
36#include "update_engine/payload_generator/graph_types.h"
37#include "update_engine/payload_generator/graph_utils.h"
38#include "update_engine/payload_generator/inplace_generator.h"
39#include "update_engine/payload_generator/metadata.h"
40#include "update_engine/payload_generator/payload_signer.h"
41#include "update_engine/payload_verifier.h"
42#include "update_engine/subprocess.h"
43#include "update_engine/update_metadata.pb.h"
44#include "update_engine/utils.h"
45
46using std::map;
47using std::max;
48using std::min;
49using std::set;
50using std::string;
51using std::unique_ptr;
52using std::vector;
53
54namespace {
55
56const uint64_t kMajorVersionNumber = 1;
57
58// The maximum destination size allowed for bsdiff. In general, bsdiff should
59// work for arbitrary big files, but the payload generation and payload
60// application requires a significant amount of RAM. We put a hard-limit of
61// 200 MiB that should not affect any released board, but will limit the
62// Chrome binary in ASan builders.
63const off_t kMaxBsdiffDestinationSize = 200 * 1024 * 1024;  // bytes
64
65static const char* kInstallOperationTypes[] = {
66  "REPLACE",
67  "REPLACE_BZ",
68  "MOVE",
69  "BSDIFF",
70  "SOURCE_COPY",
71  "SOURCE_BSDIFF"
72};
73
74}  // namespace
75
76namespace chromeos_update_engine {
77
78typedef DeltaDiffGenerator::Block Block;
79typedef map<const DeltaArchiveManifest_InstallOperation*,
80            string> OperationNameMap;
81
82// bytes
83const size_t kRootFSPartitionSize = static_cast<size_t>(2) * 1024 * 1024 * 1024;
84const size_t kBlockSize = 4096;  // bytes
85const char* const kEmptyPath = "";
86const char* const kBsdiffPath = "bsdiff";
87
88const uint32_t kInPlaceMinorPayloadVersion = 1;
89const uint32_t kSourceMinorPayloadVersion = 2;
90
91// Needed for testing purposes, in case we can't use actual filesystem objects.
92// TODO(garnold) (chromium:331965) Replace this hack with a properly injected
93// parameter in form of a mockable abstract class.
94bool (*get_extents_with_chunk_func)(const string&, off_t, off_t,
95                                    vector<Extent>*) =
96    extent_mapper::ExtentsForFileChunkFibmap;
97
98namespace {
99
100// Stores all the extents of |path| into |extents|. Returns true on success.
101bool GatherExtents(const string& path,
102                   off_t chunk_offset,
103                   off_t chunk_size,
104                   vector<Extent>* extents) {
105  extents->clear();
106  TEST_AND_RETURN_FALSE(
107      get_extents_with_chunk_func(
108          path, chunk_offset, chunk_size, extents));
109  return true;
110}
111
112// For each regular file within new_root, creates a node in the graph,
113// determines the best way to compress it (REPLACE, REPLACE_BZ, COPY, BSDIFF),
114// and writes any necessary data to the end of data_fd.
115bool DeltaReadFiles(Graph* graph,
116                    vector<Block>* blocks,
117                    const string& old_root,
118                    const string& new_root,
119                    off_t chunk_size,
120                    int data_fd,
121                    off_t* data_file_size,
122                    bool src_ops_allowed) {
123  set<ino_t> visited_inodes;
124  set<ino_t> visited_src_inodes;
125  for (FilesystemIterator fs_iter(new_root,
126                                  set<string>{"/lost+found"});
127       !fs_iter.IsEnd(); fs_iter.Increment()) {
128    // We never diff symlinks (here, we check that dst file is not a symlink).
129    if (!S_ISREG(fs_iter.GetStat().st_mode))
130      continue;
131
132    // Make sure we visit each inode only once.
133    if (utils::SetContainsKey(visited_inodes, fs_iter.GetStat().st_ino))
134      continue;
135    visited_inodes.insert(fs_iter.GetStat().st_ino);
136    off_t dst_size = fs_iter.GetFileSize();
137    if (dst_size == 0)
138      continue;
139
140    LOG(INFO) << "Encoding file " << fs_iter.GetPartialPath();
141
142    // We can't visit each dst image inode more than once, as that would
143    // duplicate work. Here, we avoid visiting each source image inode
144    // more than once. Technically, we could have multiple operations
145    // that read the same blocks from the source image for diffing, but
146    // we choose not to avoid complexity. Eventually we will move away
147    // from using a graph/cycle detection/etc to generate diffs, and at that
148    // time, it will be easy (non-complex) to have many operations read
149    // from the same source blocks. At that time, this code can die. -adlr
150    bool should_diff_from_source = false;
151    string src_path = old_root + fs_iter.GetPartialPath();
152    struct stat src_stbuf;
153    // We never diff symlinks (here, we check that src file is not a symlink).
154    if (0 == lstat(src_path.c_str(), &src_stbuf) &&
155        S_ISREG(src_stbuf.st_mode)) {
156      should_diff_from_source = !utils::SetContainsKey(visited_src_inodes,
157                                                       src_stbuf.st_ino);
158      visited_src_inodes.insert(src_stbuf.st_ino);
159    }
160
161    off_t size = chunk_size == -1 ? dst_size : chunk_size;
162    off_t step = size;
163    for (off_t offset = 0; offset < dst_size; offset += step) {
164      if (offset + size >= dst_size) {
165        size = -1;  // Read through the end of the file.
166      }
167      TEST_AND_RETURN_FALSE(DeltaDiffGenerator::DeltaReadFile(
168          graph,
169          Vertex::kInvalidIndex,
170          blocks,
171          (should_diff_from_source ? old_root : kEmptyPath),
172          new_root,
173          fs_iter.GetPartialPath(),
174          offset,
175          size,
176          data_fd,
177          data_file_size,
178          src_ops_allowed));
179    }
180  }
181  return true;
182}
183
184// Reads blocks from image_path that are not yet marked as being written in the
185// blocks array. These blocks that remain are either unchanged files or
186// non-file-data blocks.  We compare each of them to the old image, and compress
187// the ones that changed into a single REPLACE_BZ operation. This updates a
188// newly created node in the graph to write these blocks and writes the
189// appropriate blob to blobs_fd. Reads and updates blobs_length.
190bool ReadUnwrittenBlocks(const vector<Block>& blocks,
191                         int blobs_fd,
192                         off_t* blobs_length,
193                         const string& old_image_path,
194                         const string& new_image_path,
195                         Vertex* vertex) {
196  vertex->file_name = "<rootfs-non-file-data>";
197
198  DeltaArchiveManifest_InstallOperation* out_op = &vertex->op;
199  int new_image_fd = open(new_image_path.c_str(), O_RDONLY, 000);
200  TEST_AND_RETURN_FALSE_ERRNO(new_image_fd >= 0);
201  ScopedFdCloser new_image_fd_closer(&new_image_fd);
202  int old_image_fd = open(old_image_path.c_str(), O_RDONLY, 000);
203  TEST_AND_RETURN_FALSE_ERRNO(old_image_fd >= 0);
204  ScopedFdCloser old_image_fd_closer(&old_image_fd);
205
206  string temp_file_path;
207  TEST_AND_RETURN_FALSE(utils::MakeTempFile("CrAU_temp_data.XXXXXX",
208                                            &temp_file_path,
209                                            nullptr));
210
211  FILE* file = fopen(temp_file_path.c_str(), "w");
212  TEST_AND_RETURN_FALSE(file);
213  int err = BZ_OK;
214
215  BZFILE* bz_file = BZ2_bzWriteOpen(&err,
216                                    file,
217                                    9,  // max compression
218                                    0,  // verbosity
219                                    0);  // default work factor
220  TEST_AND_RETURN_FALSE(err == BZ_OK);
221
222  vector<Extent> extents;
223  vector<Block>::size_type block_count = 0;
224
225  LOG(INFO) << "Appending unwritten blocks to extents";
226  for (vector<Block>::size_type i = 0; i < blocks.size(); i++) {
227    if (blocks[i].writer != Vertex::kInvalidIndex)
228      continue;
229    graph_utils::AppendBlockToExtents(&extents, i);
230    block_count++;
231  }
232
233  // Code will handle buffers of any size that's a multiple of kBlockSize,
234  // so we arbitrarily set it to 1024 * kBlockSize.
235  chromeos::Blob new_buf(1024 * kBlockSize);
236  chromeos::Blob old_buf(1024 * kBlockSize);
237
238  LOG(INFO) << "Scanning " << block_count << " unwritten blocks";
239  vector<Extent> changed_extents;
240  vector<Block>::size_type changed_block_count = 0;
241  vector<Block>::size_type blocks_copied_count = 0;
242
243  // For each extent in extents, write the unchanged blocks into BZ2_bzWrite,
244  // which sends it to an output file.  We use the temporary buffers to hold the
245  // old and new data, which may be smaller than the extent, so in that case we
246  // have to loop to get the extent's data (that's the inner while loop).
247  for (const Extent& extent : extents) {
248    vector<Block>::size_type blocks_read = 0;
249    float printed_progress = -1;
250    while (blocks_read < extent.num_blocks()) {
251      const uint64_t copy_first_block = extent.start_block() + blocks_read;
252      const int copy_block_cnt =
253          min(new_buf.size() / kBlockSize,
254              static_cast<chromeos::Blob::size_type>(
255                  extent.num_blocks() - blocks_read));
256      const size_t count = copy_block_cnt * kBlockSize;
257      const off_t offset = copy_first_block * kBlockSize;
258      ssize_t rc = pread(new_image_fd, new_buf.data(), count, offset);
259      TEST_AND_RETURN_FALSE_ERRNO(rc >= 0);
260      TEST_AND_RETURN_FALSE(static_cast<size_t>(rc) == count);
261
262      rc = pread(old_image_fd, old_buf.data(), count, offset);
263      TEST_AND_RETURN_FALSE_ERRNO(rc >= 0);
264      TEST_AND_RETURN_FALSE(static_cast<size_t>(rc) == count);
265
266      // Compare each block in the buffer to its counterpart in the old image
267      // and only compress it if its content has changed.
268      int buf_offset = 0;
269      for (int i = 0; i < copy_block_cnt; ++i) {
270        int buf_end_offset = buf_offset + kBlockSize;
271        if (!std::equal(new_buf.begin() + buf_offset,
272                        new_buf.begin() + buf_end_offset,
273                        old_buf.begin() + buf_offset)) {
274          BZ2_bzWrite(&err, bz_file, &new_buf[buf_offset], kBlockSize);
275          TEST_AND_RETURN_FALSE(err == BZ_OK);
276          const uint64_t block_idx = copy_first_block + i;
277          if (blocks[block_idx].reader != Vertex::kInvalidIndex) {
278            graph_utils::AddReadBeforeDep(vertex, blocks[block_idx].reader,
279                                          block_idx);
280          }
281          graph_utils::AppendBlockToExtents(&changed_extents, block_idx);
282          changed_block_count++;
283        }
284        buf_offset = buf_end_offset;
285      }
286
287      blocks_read += copy_block_cnt;
288      blocks_copied_count += copy_block_cnt;
289      float current_progress =
290          static_cast<float>(blocks_copied_count) / block_count;
291      if (printed_progress + 0.1 < current_progress ||
292          blocks_copied_count == block_count) {
293        LOG(INFO) << "progress: " << current_progress;
294        printed_progress = current_progress;
295      }
296    }
297  }
298  BZ2_bzWriteClose(&err, bz_file, 0, nullptr, nullptr);
299  TEST_AND_RETURN_FALSE(err == BZ_OK);
300  bz_file = nullptr;
301  TEST_AND_RETURN_FALSE_ERRNO(0 == fclose(file));
302  file = nullptr;
303
304  LOG(INFO) << "Compressed " << changed_block_count << " blocks ("
305            << block_count - changed_block_count << " blocks unchanged)";
306  chromeos::Blob compressed_data;
307  if (changed_block_count > 0) {
308    LOG(INFO) << "Reading compressed data off disk";
309    TEST_AND_RETURN_FALSE(utils::ReadFile(temp_file_path, &compressed_data));
310  }
311  TEST_AND_RETURN_FALSE(unlink(temp_file_path.c_str()) == 0);
312
313  // Add node to graph to write these blocks
314  out_op->set_type(DeltaArchiveManifest_InstallOperation_Type_REPLACE_BZ);
315  out_op->set_data_offset(*blobs_length);
316  out_op->set_data_length(compressed_data.size());
317  LOG(INFO) << "Rootfs non-data blocks compressed take up "
318            << compressed_data.size();
319  *blobs_length += compressed_data.size();
320  out_op->set_dst_length(kBlockSize * changed_block_count);
321  DeltaDiffGenerator::StoreExtents(changed_extents,
322                                   out_op->mutable_dst_extents());
323
324  TEST_AND_RETURN_FALSE(utils::WriteAll(blobs_fd,
325                                        compressed_data.data(),
326                                        compressed_data.size()));
327  LOG(INFO) << "Done processing unwritten blocks";
328  return true;
329}
330
331// Writes the uint64_t passed in in host-endian to the file as big-endian.
332// Returns true on success.
333bool WriteUint64AsBigEndian(FileWriter* writer, const uint64_t value) {
334  uint64_t value_be = htobe64(value);
335  TEST_AND_RETURN_FALSE(writer->Write(&value_be, sizeof(value_be)));
336  return true;
337}
338
339// Adds each operation from |graph| to |out_manifest| in the order specified by
340// |order| while building |out_op_name_map| with operation to name
341// mappings. Adds all |kernel_ops| to |out_manifest|. Filters out no-op
342// operations.
343void InstallOperationsToManifest(
344    const Graph& graph,
345    const vector<Vertex::Index>& order,
346    const vector<DeltaArchiveManifest_InstallOperation>& kernel_ops,
347    DeltaArchiveManifest* out_manifest,
348    OperationNameMap* out_op_name_map) {
349  for (Vertex::Index vertex_index : order) {
350    const Vertex& vertex = graph[vertex_index];
351    const DeltaArchiveManifest_InstallOperation& add_op = vertex.op;
352    if (DeltaDiffGenerator::IsNoopOperation(add_op)) {
353      continue;
354    }
355    DeltaArchiveManifest_InstallOperation* op =
356        out_manifest->add_install_operations();
357    *op = add_op;
358    string name = vertex.file_name;
359    if (vertex.chunk_offset || vertex.chunk_size != -1) {
360      string offset = base::Int64ToString(vertex.chunk_offset);
361      if (vertex.chunk_size != -1) {
362        name += " [" + offset + ", " +
363            base::Int64ToString(vertex.chunk_offset + vertex.chunk_size - 1) +
364            "]";
365      } else {
366        name += " [" + offset + ", end]";
367      }
368    }
369    (*out_op_name_map)[op] = name;
370  }
371  for (vector<DeltaArchiveManifest_InstallOperation>::const_iterator it =
372           kernel_ops.begin(); it != kernel_ops.end(); ++it) {
373    const DeltaArchiveManifest_InstallOperation& add_op = *it;
374    if (DeltaDiffGenerator::IsNoopOperation(add_op)) {
375      continue;
376    }
377    DeltaArchiveManifest_InstallOperation* op =
378        out_manifest->add_kernel_install_operations();
379    *op = add_op;
380  }
381}
382
383// Delta compresses a kernel partition |new_kernel_part| with knowledge of the
384// old kernel partition |old_kernel_part|. If |old_kernel_part| is an empty
385// string, generates a full update of the partition.
386bool DeltaCompressKernelPartition(
387    const string& old_kernel_part,
388    const string& new_kernel_part,
389    vector<DeltaArchiveManifest_InstallOperation>* ops,
390    int blobs_fd,
391    off_t* blobs_length,
392    bool src_ops_allowed) {
393  LOG(INFO) << "Delta compressing kernel partition...";
394  LOG_IF(INFO, old_kernel_part.empty()) << "Generating full kernel update...";
395
396  DeltaArchiveManifest_InstallOperation op;
397  chromeos::Blob data;
398  TEST_AND_RETURN_FALSE(
399      DeltaDiffGenerator::ReadFileToDiff(old_kernel_part,
400                                         new_kernel_part,
401                                         0,  // chunk_offset
402                                         -1,  // chunk_size
403                                         true,  // bsdiff_allowed
404                                         &data,
405                                         &op,
406                                         false,
407                                         src_ops_allowed));
408
409  // Check if the operation writes nothing.
410  if (op.dst_extents_size() == 0) {
411    if (op.type() == DeltaArchiveManifest_InstallOperation_Type_MOVE) {
412      LOG(INFO) << "Empty MOVE operation, nothing to do.";
413      return true;
414    } else {
415      LOG(ERROR) << "Empty non-MOVE operation";
416      return false;
417    }
418  }
419
420  // Write the data.
421  if (op.type() != DeltaArchiveManifest_InstallOperation_Type_MOVE &&
422      op.type() != DeltaArchiveManifest_InstallOperation_Type_SOURCE_COPY) {
423    op.set_data_offset(*blobs_length);
424    op.set_data_length(data.size());
425  }
426
427  // Add the new install operation.
428  ops->clear();
429  ops->push_back(op);
430
431  TEST_AND_RETURN_FALSE(utils::WriteAll(blobs_fd, data.data(), data.size()));
432  *blobs_length += data.size();
433
434  LOG(INFO) << "Done delta compressing kernel partition: "
435            << kInstallOperationTypes[op.type()];
436  return true;
437}
438
439struct DeltaObject {
440  DeltaObject(const string& in_name, const int in_type, const off_t in_size)
441      : name(in_name),
442        type(in_type),
443        size(in_size) {}
444  bool operator <(const DeltaObject& object) const {
445    return (size != object.size) ? (size < object.size) : (name < object.name);
446  }
447  string name;
448  int type;
449  off_t size;
450};
451
452void ReportPayloadUsage(const DeltaArchiveManifest& manifest,
453                        const int64_t manifest_metadata_size,
454                        const OperationNameMap& op_name_map) {
455  vector<DeltaObject> objects;
456  off_t total_size = 0;
457
458  // Rootfs install operations.
459  for (int i = 0; i < manifest.install_operations_size(); ++i) {
460    const DeltaArchiveManifest_InstallOperation& op =
461        manifest.install_operations(i);
462    objects.push_back(DeltaObject(op_name_map.find(&op)->second,
463                                  op.type(),
464                                  op.data_length()));
465    total_size += op.data_length();
466  }
467
468  // Kernel install operations.
469  for (int i = 0; i < manifest.kernel_install_operations_size(); ++i) {
470    const DeltaArchiveManifest_InstallOperation& op =
471        manifest.kernel_install_operations(i);
472    objects.push_back(DeltaObject(base::StringPrintf("<kernel-operation-%d>",
473                                                     i),
474                                  op.type(),
475                                  op.data_length()));
476    total_size += op.data_length();
477  }
478
479  objects.push_back(DeltaObject("<manifest-metadata>",
480                                -1,
481                                manifest_metadata_size));
482  total_size += manifest_metadata_size;
483
484  std::sort(objects.begin(), objects.end());
485
486  static const char kFormatString[] = "%6.2f%% %10jd %-10s %s\n";
487  for (const DeltaObject& object : objects) {
488    fprintf(stderr, kFormatString,
489            object.size * 100.0 / total_size,
490            static_cast<intmax_t>(object.size),
491            object.type >= 0 ? kInstallOperationTypes[object.type] : "-",
492            object.name.c_str());
493  }
494  fprintf(stderr, kFormatString,
495          100.0, static_cast<intmax_t>(total_size), "", "<total>");
496}
497
498// Process a range of blocks from |range_start| to |range_end| in the extent at
499// position |*idx_p| of |extents|. If |do_remove| is true, this range will be
500// removed, which may cause the extent to be trimmed, split or removed entirely.
501// The value of |*idx_p| is updated to point to the next extent to be processed.
502// Returns true iff the next extent to process is a new or updated one.
503bool ProcessExtentBlockRange(vector<Extent>* extents, size_t* idx_p,
504                             const bool do_remove, uint64_t range_start,
505                             uint64_t range_end) {
506  size_t idx = *idx_p;
507  uint64_t start_block = (*extents)[idx].start_block();
508  uint64_t num_blocks = (*extents)[idx].num_blocks();
509  uint64_t range_size = range_end - range_start;
510
511  if (do_remove) {
512    if (range_size == num_blocks) {
513      // Remove the entire extent.
514      extents->erase(extents->begin() + idx);
515    } else if (range_end == num_blocks) {
516      // Trim the end of the extent.
517      (*extents)[idx].set_num_blocks(num_blocks - range_size);
518      idx++;
519    } else if (range_start == 0) {
520      // Trim the head of the extent.
521      (*extents)[idx].set_start_block(start_block + range_size);
522      (*extents)[idx].set_num_blocks(num_blocks - range_size);
523    } else {
524      // Trim the middle, splitting the remainder into two parts.
525      (*extents)[idx].set_num_blocks(range_start);
526      Extent e;
527      e.set_start_block(start_block + range_end);
528      e.set_num_blocks(num_blocks - range_end);
529      idx++;
530      extents->insert(extents->begin() + idx, e);
531    }
532  } else if (range_end == num_blocks) {
533    // Done with this extent.
534    idx++;
535  } else {
536    return false;
537  }
538
539  *idx_p = idx;
540  return true;
541}
542
543// Remove identical corresponding block ranges in |src_extents| and
544// |dst_extents|. Used for preventing moving of blocks onto themselves during
545// MOVE operations. The value of |total_bytes| indicates the actual length of
546// content; this may be slightly less than the total size of blocks, in which
547// case the last block is only partly occupied with data. Returns the total
548// number of bytes removed.
549size_t RemoveIdenticalBlockRanges(vector<Extent>* src_extents,
550                                  vector<Extent>* dst_extents,
551                                  const size_t total_bytes) {
552  size_t src_idx = 0;
553  size_t dst_idx = 0;
554  uint64_t src_offset = 0, dst_offset = 0;
555  bool new_src = true, new_dst = true;
556  size_t removed_bytes = 0, nonfull_block_bytes;
557  bool do_remove = false;
558  while (src_idx < src_extents->size() && dst_idx < dst_extents->size()) {
559    if (new_src) {
560      src_offset = 0;
561      new_src = false;
562    }
563    if (new_dst) {
564      dst_offset = 0;
565      new_dst = false;
566    }
567
568    do_remove = ((*src_extents)[src_idx].start_block() + src_offset ==
569                 (*dst_extents)[dst_idx].start_block() + dst_offset);
570
571    uint64_t src_num_blocks = (*src_extents)[src_idx].num_blocks();
572    uint64_t dst_num_blocks = (*dst_extents)[dst_idx].num_blocks();
573    uint64_t min_num_blocks = min(src_num_blocks - src_offset,
574                                  dst_num_blocks - dst_offset);
575    uint64_t prev_src_offset = src_offset;
576    uint64_t prev_dst_offset = dst_offset;
577    src_offset += min_num_blocks;
578    dst_offset += min_num_blocks;
579
580    new_src = ProcessExtentBlockRange(src_extents, &src_idx, do_remove,
581                                      prev_src_offset, src_offset);
582    new_dst = ProcessExtentBlockRange(dst_extents, &dst_idx, do_remove,
583                                      prev_dst_offset, dst_offset);
584    if (do_remove)
585      removed_bytes += min_num_blocks * kBlockSize;
586  }
587
588  // If we removed the last block and this block is only partly used by file
589  // content, deduct the unused portion from the total removed byte count.
590  if (do_remove && (nonfull_block_bytes = total_bytes % kBlockSize))
591    removed_bytes -= kBlockSize - nonfull_block_bytes;
592
593  return removed_bytes;
594}
595
596}  // namespace
597
598void DeltaDiffGenerator::CheckGraph(const Graph& graph) {
599  for (const Vertex& v : graph) {
600    CHECK(v.op.has_type());
601  }
602}
603
604bool DeltaDiffGenerator::DeltaReadFile(Graph* graph,
605                                       Vertex::Index existing_vertex,
606                                       vector<Block>* blocks,
607                                       const string& old_root,
608                                       const string& new_root,
609                                       const string& path,  // within new_root
610                                       off_t chunk_offset,
611                                       off_t chunk_size,
612                                       int data_fd,
613                                       off_t* data_file_size,
614                                       bool src_ops_allowed) {
615  chromeos::Blob data;
616  DeltaArchiveManifest_InstallOperation operation;
617
618  string old_path = (old_root == kEmptyPath) ? kEmptyPath :
619      old_root + path;
620
621  // If bsdiff breaks again, blacklist the problem file by using:
622  //   bsdiff_allowed = (path != "/foo/bar")
623  //
624  // TODO(dgarrett): chromium-os:15274 connect this test to the command line.
625  bool bsdiff_allowed = true;
626
627  if (utils::FileSize(new_root + path) > kMaxBsdiffDestinationSize)
628    bsdiff_allowed = false;
629
630  if (!bsdiff_allowed)
631    LOG(INFO) << "bsdiff blacklisting: " << path;
632
633  TEST_AND_RETURN_FALSE(DeltaDiffGenerator::ReadFileToDiff(old_path,
634                                                           new_root + path,
635                                                           chunk_offset,
636                                                           chunk_size,
637                                                           bsdiff_allowed,
638                                                           &data,
639                                                           &operation,
640                                                           true,
641                                                           src_ops_allowed));
642
643  // Check if the operation writes nothing.
644  if (operation.dst_extents_size() == 0) {
645    if (operation.type() == DeltaArchiveManifest_InstallOperation_Type_MOVE) {
646      LOG(INFO) << "Empty MOVE operation ("
647                << new_root + path << "), skipping";
648      return true;
649    } else {
650      LOG(ERROR) << "Empty non-MOVE operation";
651      return false;
652    }
653  }
654
655  // Write the data
656  if (operation.type() != DeltaArchiveManifest_InstallOperation_Type_MOVE &&
657      operation.type() !=
658          DeltaArchiveManifest_InstallOperation_Type_SOURCE_COPY) {
659    operation.set_data_offset(*data_file_size);
660    operation.set_data_length(data.size());
661  }
662
663  TEST_AND_RETURN_FALSE(utils::WriteAll(data_fd, data.data(), data.size()));
664  *data_file_size += data.size();
665
666  // Now, insert into graph and blocks vector
667  Vertex::Index vertex = existing_vertex;
668  if (vertex == Vertex::kInvalidIndex) {
669    graph->resize(graph->size() + 1);
670    vertex = graph->size() - 1;
671  }
672  (*graph)[vertex].op = operation;
673  CHECK((*graph)[vertex].op.has_type());
674  (*graph)[vertex].file_name = path;
675  (*graph)[vertex].chunk_offset = chunk_offset;
676  (*graph)[vertex].chunk_size = chunk_size;
677
678  if (blocks)
679    TEST_AND_RETURN_FALSE(InplaceGenerator::AddInstallOpToBlocksVector(
680        (*graph)[vertex].op,
681        *graph,
682        vertex,
683        blocks));
684  return true;
685}
686
687
688bool DeltaDiffGenerator::ReadFileToDiff(
689    const string& old_filename,
690    const string& new_filename,
691    off_t chunk_offset,
692    off_t chunk_size,
693    bool bsdiff_allowed,
694    chromeos::Blob* out_data,
695    DeltaArchiveManifest_InstallOperation* out_op,
696    bool gather_extents,
697    bool src_ops_allowed) {
698  // Read new data in
699  chromeos::Blob new_data;
700  TEST_AND_RETURN_FALSE(
701      utils::ReadFileChunk(new_filename, chunk_offset, chunk_size, &new_data));
702
703  TEST_AND_RETURN_FALSE(!new_data.empty());
704  TEST_AND_RETURN_FALSE(chunk_size == -1 ||
705                        static_cast<off_t>(new_data.size()) <= chunk_size);
706
707  chromeos::Blob new_data_bz;
708  TEST_AND_RETURN_FALSE(BzipCompress(new_data, &new_data_bz));
709  CHECK(!new_data_bz.empty());
710
711  chromeos::Blob data;  // Data blob that will be written to delta file.
712
713  DeltaArchiveManifest_InstallOperation operation;
714  size_t current_best_size = 0;
715  if (new_data.size() <= new_data_bz.size()) {
716    operation.set_type(DeltaArchiveManifest_InstallOperation_Type_REPLACE);
717    current_best_size = new_data.size();
718    data = new_data;
719  } else {
720    operation.set_type(DeltaArchiveManifest_InstallOperation_Type_REPLACE_BZ);
721    current_best_size = new_data_bz.size();
722    data = new_data_bz;
723  }
724
725  // Do we have an original file to consider?
726  off_t old_size = 0;
727  bool original = !old_filename.empty();
728  if (original && (old_size = utils::FileSize(old_filename)) < 0) {
729    // If stat-ing the old file fails, it should be because it doesn't exist.
730    TEST_AND_RETURN_FALSE(!utils::FileExists(old_filename.c_str()));
731    original = false;
732  }
733
734  chromeos::Blob old_data;
735  if (original) {
736    // Read old data
737    TEST_AND_RETURN_FALSE(
738        utils::ReadFileChunk(
739            old_filename, chunk_offset, chunk_size, &old_data));
740    if (old_data == new_data) {
741      // No change in data.
742      if (src_ops_allowed) {
743        operation.set_type(
744            DeltaArchiveManifest_InstallOperation_Type_SOURCE_COPY);
745      } else {
746        operation.set_type(DeltaArchiveManifest_InstallOperation_Type_MOVE);
747      }
748      current_best_size = 0;
749      data.clear();
750    } else if (!old_data.empty() && bsdiff_allowed) {
751      // If the source file is considered bsdiff safe (no bsdiff bugs
752      // triggered), see if BSDIFF encoding is smaller.
753      base::FilePath old_chunk;
754      TEST_AND_RETURN_FALSE(base::CreateTemporaryFile(&old_chunk));
755      ScopedPathUnlinker old_unlinker(old_chunk.value());
756      TEST_AND_RETURN_FALSE(
757          utils::WriteFile(old_chunk.value().c_str(),
758                           old_data.data(), old_data.size()));
759      base::FilePath new_chunk;
760      TEST_AND_RETURN_FALSE(base::CreateTemporaryFile(&new_chunk));
761      ScopedPathUnlinker new_unlinker(new_chunk.value());
762      TEST_AND_RETURN_FALSE(
763          utils::WriteFile(new_chunk.value().c_str(),
764                           new_data.data(), new_data.size()));
765
766      chromeos::Blob bsdiff_delta;
767      TEST_AND_RETURN_FALSE(
768          BsdiffFiles(old_chunk.value(), new_chunk.value(), &bsdiff_delta));
769      CHECK_GT(bsdiff_delta.size(), static_cast<chromeos::Blob::size_type>(0));
770      if (bsdiff_delta.size() < current_best_size) {
771        if (src_ops_allowed) {
772          operation.set_type(
773              DeltaArchiveManifest_InstallOperation_Type_SOURCE_BSDIFF);
774        } else {
775          operation.set_type(DeltaArchiveManifest_InstallOperation_Type_BSDIFF);
776        }
777        current_best_size = bsdiff_delta.size();
778        data = bsdiff_delta;
779      }
780    }
781  }
782
783  // Set parameters of the operations
784  CHECK_EQ(data.size(), current_best_size);
785
786  vector<Extent> src_extents, dst_extents;
787  if (operation.type() == DeltaArchiveManifest_InstallOperation_Type_MOVE ||
788      operation.type() == DeltaArchiveManifest_InstallOperation_Type_BSDIFF ||
789      operation.type() ==
790          DeltaArchiveManifest_InstallOperation_Type_SOURCE_COPY ||
791      operation.type() ==
792          DeltaArchiveManifest_InstallOperation_Type_SOURCE_BSDIFF) {
793    if (gather_extents) {
794      TEST_AND_RETURN_FALSE(
795          GatherExtents(old_filename,
796                        chunk_offset,
797                        chunk_size,
798                        &src_extents));
799    } else {
800      Extent* src_extent = operation.add_src_extents();
801      src_extent->set_start_block(0);
802      src_extent->set_num_blocks((old_size + kBlockSize - 1) / kBlockSize);
803    }
804    operation.set_src_length(old_data.size());
805  }
806
807  if (gather_extents) {
808    TEST_AND_RETURN_FALSE(
809        GatherExtents(new_filename,
810                      chunk_offset,
811                      chunk_size,
812                      &dst_extents));
813  } else {
814    Extent* dst_extent = operation.add_dst_extents();
815    dst_extent->set_start_block(0);
816    dst_extent->set_num_blocks((new_data.size() + kBlockSize - 1) / kBlockSize);
817  }
818  operation.set_dst_length(new_data.size());
819
820  if (gather_extents) {
821    // Remove identical src/dst block ranges in MOVE operations.
822    if (operation.type() == DeltaArchiveManifest_InstallOperation_Type_MOVE) {
823      size_t removed_bytes = RemoveIdenticalBlockRanges(
824          &src_extents, &dst_extents, new_data.size());
825
826      // Adjust the file length field accordingly.
827      if (removed_bytes) {
828        operation.set_src_length(old_data.size() - removed_bytes);
829        operation.set_dst_length(new_data.size() - removed_bytes);
830      }
831    }
832
833    // Embed extents in the operation.
834    DeltaDiffGenerator::StoreExtents(src_extents,
835                                     operation.mutable_src_extents());
836    DeltaDiffGenerator::StoreExtents(dst_extents,
837                                     operation.mutable_dst_extents());
838  }
839
840  out_data->swap(data);
841  *out_op = operation;
842
843  return true;
844}
845
846bool DeltaDiffGenerator::InitializePartitionInfo(bool is_kernel,
847                                                 const string& partition,
848                                                 PartitionInfo* info) {
849  int64_t size = 0;
850  if (is_kernel) {
851    size = utils::FileSize(partition);
852  } else {
853    int block_count = 0, block_size = 0;
854    TEST_AND_RETURN_FALSE(utils::GetFilesystemSize(partition,
855                                                   &block_count,
856                                                   &block_size));
857    size = static_cast<int64_t>(block_count) * block_size;
858  }
859  TEST_AND_RETURN_FALSE(size > 0);
860  info->set_size(size);
861  OmahaHashCalculator hasher;
862  TEST_AND_RETURN_FALSE(hasher.UpdateFile(partition, size) == size);
863  TEST_AND_RETURN_FALSE(hasher.Finalize());
864  const chromeos::Blob& hash = hasher.raw_hash();
865  info->set_hash(hash.data(), hash.size());
866  LOG(INFO) << partition << ": size=" << size << " hash=" << hasher.hash();
867  return true;
868}
869
870bool InitializePartitionInfos(const PayloadGenerationConfig& config,
871                              DeltaArchiveManifest* manifest) {
872  if (!config.source.kernel_part.empty()) {
873    TEST_AND_RETURN_FALSE(DeltaDiffGenerator::InitializePartitionInfo(
874        true,
875        config.source.kernel_part,
876        manifest->mutable_old_kernel_info()));
877  }
878  TEST_AND_RETURN_FALSE(DeltaDiffGenerator::InitializePartitionInfo(
879      true,
880      config.target.kernel_part,
881      manifest->mutable_new_kernel_info()));
882  if (!config.source.rootfs_part.empty()) {
883    TEST_AND_RETURN_FALSE(DeltaDiffGenerator::InitializePartitionInfo(
884        false,
885        config.source.rootfs_part,
886        manifest->mutable_old_rootfs_info()));
887  }
888  TEST_AND_RETURN_FALSE(DeltaDiffGenerator::InitializePartitionInfo(
889      false,
890      config.target.rootfs_part,
891      manifest->mutable_new_rootfs_info()));
892  return true;
893}
894
895// Stores all Extents in 'extents' into 'out'.
896void DeltaDiffGenerator::StoreExtents(
897    const vector<Extent>& extents,
898    google::protobuf::RepeatedPtrField<Extent>* out) {
899  for (const Extent& extent : extents) {
900    Extent* new_extent = out->Add();
901    *new_extent = extent;
902  }
903}
904
905// Returns true if |op| is a no-op operation that doesn't do any useful work
906// (e.g., a move operation that copies blocks onto themselves).
907bool DeltaDiffGenerator::IsNoopOperation(
908    const DeltaArchiveManifest_InstallOperation& op) {
909  return (op.type() == DeltaArchiveManifest_InstallOperation_Type_MOVE &&
910          ExpandExtents(op.src_extents()) == ExpandExtents(op.dst_extents()));
911}
912
913bool DeltaDiffGenerator::ReorderDataBlobs(
914    DeltaArchiveManifest* manifest,
915    const string& data_blobs_path,
916    const string& new_data_blobs_path) {
917  int in_fd = open(data_blobs_path.c_str(), O_RDONLY, 0);
918  TEST_AND_RETURN_FALSE_ERRNO(in_fd >= 0);
919  ScopedFdCloser in_fd_closer(&in_fd);
920
921  DirectFileWriter writer;
922  TEST_AND_RETURN_FALSE(
923      writer.Open(new_data_blobs_path.c_str(),
924                  O_WRONLY | O_TRUNC | O_CREAT,
925                  0644) == 0);
926  ScopedFileWriterCloser writer_closer(&writer);
927  uint64_t out_file_size = 0;
928
929  for (int i = 0; i < (manifest->install_operations_size() +
930                       manifest->kernel_install_operations_size()); i++) {
931    DeltaArchiveManifest_InstallOperation* op = nullptr;
932    if (i < manifest->install_operations_size()) {
933      op = manifest->mutable_install_operations(i);
934    } else {
935      op = manifest->mutable_kernel_install_operations(
936          i - manifest->install_operations_size());
937    }
938    if (!op->has_data_offset())
939      continue;
940    CHECK(op->has_data_length());
941    chromeos::Blob buf(op->data_length());
942    ssize_t rc = pread(in_fd, buf.data(), buf.size(), op->data_offset());
943    TEST_AND_RETURN_FALSE(rc == static_cast<ssize_t>(buf.size()));
944
945    // Add the hash of the data blobs for this operation
946    TEST_AND_RETURN_FALSE(AddOperationHash(op, buf));
947
948    op->set_data_offset(out_file_size);
949    TEST_AND_RETURN_FALSE(writer.Write(buf.data(), buf.size()));
950    out_file_size += buf.size();
951  }
952  return true;
953}
954
955bool DeltaDiffGenerator::AddOperationHash(
956    DeltaArchiveManifest_InstallOperation* op,
957    const chromeos::Blob& buf) {
958  OmahaHashCalculator hasher;
959
960  TEST_AND_RETURN_FALSE(hasher.Update(buf.data(), buf.size()));
961  TEST_AND_RETURN_FALSE(hasher.Finalize());
962
963  const chromeos::Blob& hash = hasher.raw_hash();
964  op->set_data_sha256_hash(hash.data(), hash.size());
965  return true;
966}
967
968vector<Vertex::Index> DeltaDiffGenerator::OrderIndices(const Graph& graph) {
969  vector<Vertex::Index> order(graph.size());
970  std::iota(order.begin(), order.end(), 0);
971  return order;
972}
973
974bool DeltaDiffGenerator::GenerateDeltaUpdateFile(
975    const PayloadGenerationConfig& config,
976    const string& output_path,
977    const string& private_key_path,
978    size_t rootfs_partition_size,
979    uint64_t* metadata_size) {
980  int old_image_block_count = config.source.rootfs_size / config.block_size;
981  int new_image_block_count = config.target.rootfs_size / config.block_size;
982
983  if (config.is_delta) {
984    LOG_IF(WARNING, old_image_block_count != new_image_block_count)
985        << "Old and new images have different block counts.";
986    // TODO(deymo): Our tools only support growing the filesystem size during
987    // an update. Remove this check when that's fixed. crbug.com/192136
988    LOG_IF(FATAL, old_image_block_count > new_image_block_count)
989        << "Shirking the rootfs size is not supported at the moment.";
990  }
991
992  // Sanity checks for the partition size.
993  TEST_AND_RETURN_FALSE(rootfs_partition_size % config.block_size == 0);
994  LOG(INFO) << "Rootfs partition size: " << rootfs_partition_size;
995  LOG(INFO) << "Actual filesystem size: " << config.target.rootfs_size;
996  TEST_AND_RETURN_FALSE(rootfs_partition_size >= config.target.rootfs_size);
997
998  vector<Block> blocks(max(old_image_block_count, new_image_block_count));
999  LOG(INFO) << "Invalid block index: " << Vertex::kInvalidIndex;
1000  LOG(INFO) << "Block count: " << blocks.size();
1001  for (const Block& block : blocks) {
1002    CHECK(block.reader == Vertex::kInvalidIndex);
1003    CHECK(block.writer == Vertex::kInvalidIndex);
1004  }
1005  Graph graph;
1006  CheckGraph(graph);
1007
1008  const string kTempFileTemplate("CrAU_temp_data.XXXXXX");
1009  string temp_file_path;
1010  unique_ptr<ScopedPathUnlinker> temp_file_unlinker;
1011  off_t data_file_size = 0;
1012
1013  LOG(INFO) << "Reading files...";
1014
1015  // Create empty protobuf Manifest object
1016  DeltaArchiveManifest manifest;
1017
1018  vector<DeltaArchiveManifest_InstallOperation> kernel_ops;
1019
1020  vector<Vertex::Index> final_order;
1021  Vertex::Index scratch_vertex = Vertex::kInvalidIndex;
1022  {
1023    int data_file_fd;
1024    TEST_AND_RETURN_FALSE(
1025        utils::MakeTempFile(kTempFileTemplate, &temp_file_path, &data_file_fd));
1026    temp_file_unlinker.reset(new ScopedPathUnlinker(temp_file_path));
1027    TEST_AND_RETURN_FALSE(data_file_fd >= 0);
1028    ScopedFdCloser data_file_fd_closer(&data_file_fd);
1029    if (config.is_delta) {
1030      // Delta update
1031
1032      // Set the minor version for this payload.
1033      LOG(INFO) << "Adding Delta Minor Version.";
1034      manifest.set_minor_version(config.minor_version);
1035      if (config.minor_version == kInPlaceMinorPayloadVersion) {
1036        TEST_AND_RETURN_FALSE(DeltaReadFiles(&graph,
1037                                             &blocks,
1038                                             config.source.rootfs_mountpt,
1039                                             config.target.rootfs_mountpt,
1040                                             config.chunk_size,
1041                                             data_file_fd,
1042                                             &data_file_size,
1043                                             false));  // src_ops_allowed
1044        LOG(INFO) << "done reading normal files";
1045        CheckGraph(graph);
1046
1047        LOG(INFO) << "Starting metadata processing";
1048        TEST_AND_RETURN_FALSE(Metadata::DeltaReadMetadata(
1049            &graph,
1050            &blocks,
1051            config.source.rootfs_part,
1052            config.target.rootfs_part,
1053            data_file_fd,
1054            &data_file_size));
1055        LOG(INFO) << "Done metadata processing";
1056        CheckGraph(graph);
1057
1058        graph.resize(graph.size() + 1);
1059        TEST_AND_RETURN_FALSE(ReadUnwrittenBlocks(blocks,
1060                                                  data_file_fd,
1061                                                  &data_file_size,
1062                                                  config.source.rootfs_part,
1063                                                  config.target.rootfs_part,
1064                                                  &graph.back()));
1065        if (graph.back().op.data_length() == 0) {
1066          LOG(INFO) << "No unwritten blocks to write, omitting operation";
1067          graph.pop_back();
1068        }
1069
1070        // Final scratch block (if there's space)
1071        if (blocks.size() < (rootfs_partition_size / kBlockSize)) {
1072          scratch_vertex = graph.size();
1073          graph.resize(graph.size() + 1);
1074          InplaceGenerator::CreateScratchNode(
1075              blocks.size(),
1076              (rootfs_partition_size / kBlockSize) - blocks.size(),
1077              &graph.back());
1078        }
1079
1080        // Read kernel partition
1081        TEST_AND_RETURN_FALSE(
1082            DeltaCompressKernelPartition(config.source.kernel_part,
1083                                         config.target.kernel_part,
1084                                         &kernel_ops,
1085                                         data_file_fd,
1086                                         &data_file_size,
1087                                         false));  // src_ops_allowed
1088
1089        LOG(INFO) << "done reading kernel";
1090        CheckGraph(graph);
1091
1092        LOG(INFO) << "Creating edges...";
1093        InplaceGenerator::CreateEdges(&graph, blocks);
1094        LOG(INFO) << "Done creating edges";
1095        CheckGraph(graph);
1096
1097        TEST_AND_RETURN_FALSE(InplaceGenerator::ConvertGraphToDag(
1098            &graph,
1099            config.target.rootfs_mountpt,
1100            data_file_fd,
1101            &data_file_size,
1102            &final_order,
1103            scratch_vertex));
1104      } else if (config.minor_version == kSourceMinorPayloadVersion) {
1105        TEST_AND_RETURN_FALSE(DeltaReadFiles(&graph,
1106                                             &blocks,
1107                                             config.source.rootfs_mountpt,
1108                                             config.target.rootfs_mountpt,
1109                                             config.chunk_size,
1110                                             data_file_fd,
1111                                             &data_file_size,
1112                                             true));  // src_ops_allowed
1113
1114        LOG(INFO) << "done reading normal files";
1115        CheckGraph(graph);
1116
1117        // Read kernel partition
1118        TEST_AND_RETURN_FALSE(
1119            DeltaCompressKernelPartition(config.source.kernel_part,
1120                                         config.target.kernel_part,
1121                                         &kernel_ops,
1122                                         data_file_fd,
1123                                         &data_file_size,
1124                                         true));  // src_ops_allowed
1125        LOG(INFO) << "done reading kernel";
1126        CheckGraph(graph);
1127
1128        graph.resize(graph.size() + 1);
1129        TEST_AND_RETURN_FALSE(ReadUnwrittenBlocks(blocks,
1130                                                  data_file_fd,
1131                                                  &data_file_size,
1132                                                  config.source.rootfs_part,
1133                                                  config.target.rootfs_part,
1134                                                  &graph.back()));
1135        if (graph.back().op.data_length() == 0) {
1136          LOG(INFO) << "No unwritten blocks to write, omitting operation";
1137          graph.pop_back();
1138        }
1139
1140        final_order = OrderIndices(graph);
1141      } else {
1142        LOG(ERROR) << "Unsupported minor version given for delta payload: "
1143                   << config.minor_version;
1144        return false;
1145      }
1146    } else {
1147      TEST_AND_RETURN_FALSE(FullUpdateGenerator::Run(config,
1148                                                     data_file_fd,
1149                                                     &data_file_size,
1150                                                     &graph,
1151                                                     &kernel_ops,
1152                                                     &final_order));
1153
1154      // Set the minor version for this payload.
1155      LOG(INFO) << "Adding Full Minor Version.";
1156      manifest.set_minor_version(DeltaPerformer::kFullPayloadMinorVersion);
1157    }
1158  }
1159
1160  if (!config.source.ImageInfoIsEmpty())
1161    *(manifest.mutable_old_image_info()) = config.source.image_info;
1162
1163  if (!config.target.ImageInfoIsEmpty())
1164    *(manifest.mutable_new_image_info()) = config.target.image_info;
1165
1166  OperationNameMap op_name_map;
1167  CheckGraph(graph);
1168  InstallOperationsToManifest(graph,
1169                              final_order,
1170                              kernel_ops,
1171                              &manifest,
1172                              &op_name_map);
1173  CheckGraph(graph);
1174  manifest.set_block_size(kBlockSize);
1175
1176  // Reorder the data blobs with the newly ordered manifest
1177  string ordered_blobs_path;
1178  TEST_AND_RETURN_FALSE(utils::MakeTempFile(
1179      "CrAU_temp_data.ordered.XXXXXX",
1180      &ordered_blobs_path,
1181      nullptr));
1182  ScopedPathUnlinker ordered_blobs_unlinker(ordered_blobs_path);
1183  TEST_AND_RETURN_FALSE(ReorderDataBlobs(&manifest,
1184                                         temp_file_path,
1185                                         ordered_blobs_path));
1186  temp_file_unlinker.reset();
1187
1188  // Check that install op blobs are in order.
1189  uint64_t next_blob_offset = 0;
1190  {
1191    for (int i = 0; i < (manifest.install_operations_size() +
1192                         manifest.kernel_install_operations_size()); i++) {
1193      DeltaArchiveManifest_InstallOperation* op =
1194          i < manifest.install_operations_size() ?
1195          manifest.mutable_install_operations(i) :
1196          manifest.mutable_kernel_install_operations(
1197              i - manifest.install_operations_size());
1198      if (op->has_data_offset()) {
1199        if (op->data_offset() != next_blob_offset) {
1200          LOG(FATAL) << "bad blob offset! " << op->data_offset() << " != "
1201                     << next_blob_offset;
1202        }
1203        next_blob_offset += op->data_length();
1204      }
1205    }
1206  }
1207
1208  // Signatures appear at the end of the blobs. Note the offset in the
1209  // manifest
1210  if (!private_key_path.empty()) {
1211    uint64_t signature_blob_length = 0;
1212    TEST_AND_RETURN_FALSE(
1213        PayloadSigner::SignatureBlobLength(vector<string>(1, private_key_path),
1214                                           &signature_blob_length));
1215    AddSignatureOp(next_blob_offset, signature_blob_length, &manifest);
1216  }
1217
1218  TEST_AND_RETURN_FALSE(InitializePartitionInfos(config, &manifest));
1219
1220  // Serialize protobuf
1221  string serialized_manifest;
1222
1223  CheckGraph(graph);
1224  TEST_AND_RETURN_FALSE(manifest.AppendToString(&serialized_manifest));
1225  CheckGraph(graph);
1226
1227  LOG(INFO) << "Writing final delta file header...";
1228  DirectFileWriter writer;
1229  TEST_AND_RETURN_FALSE_ERRNO(writer.Open(output_path.c_str(),
1230                                          O_WRONLY | O_CREAT | O_TRUNC,
1231                                          0644) == 0);
1232  ScopedFileWriterCloser writer_closer(&writer);
1233
1234  // Write header
1235  TEST_AND_RETURN_FALSE(writer.Write(kDeltaMagic, strlen(kDeltaMagic)));
1236
1237  // Write major version number
1238  TEST_AND_RETURN_FALSE(WriteUint64AsBigEndian(&writer, kMajorVersionNumber));
1239
1240  // Write protobuf length
1241  TEST_AND_RETURN_FALSE(WriteUint64AsBigEndian(&writer,
1242                                               serialized_manifest.size()));
1243
1244  // Write protobuf
1245  LOG(INFO) << "Writing final delta file protobuf... "
1246            << serialized_manifest.size();
1247  TEST_AND_RETURN_FALSE(writer.Write(serialized_manifest.data(),
1248                                     serialized_manifest.size()));
1249
1250  // Append the data blobs
1251  LOG(INFO) << "Writing final delta file data blobs...";
1252  int blobs_fd = open(ordered_blobs_path.c_str(), O_RDONLY, 0);
1253  ScopedFdCloser blobs_fd_closer(&blobs_fd);
1254  TEST_AND_RETURN_FALSE(blobs_fd >= 0);
1255  for (;;) {
1256    char buf[kBlockSize];
1257    ssize_t rc = read(blobs_fd, buf, sizeof(buf));
1258    if (0 == rc) {
1259      // EOF
1260      break;
1261    }
1262    TEST_AND_RETURN_FALSE_ERRNO(rc > 0);
1263    TEST_AND_RETURN_FALSE(writer.Write(buf, rc));
1264  }
1265
1266  // Write signature blob.
1267  if (!private_key_path.empty()) {
1268    LOG(INFO) << "Signing the update...";
1269    chromeos::Blob signature_blob;
1270    TEST_AND_RETURN_FALSE(PayloadSigner::SignPayload(
1271        output_path,
1272        vector<string>(1, private_key_path),
1273        &signature_blob));
1274    TEST_AND_RETURN_FALSE(writer.Write(signature_blob.data(),
1275                                       signature_blob.size()));
1276  }
1277
1278  *metadata_size =
1279      strlen(kDeltaMagic) + 2 * sizeof(uint64_t) + serialized_manifest.size();
1280  ReportPayloadUsage(manifest, *metadata_size, op_name_map);
1281
1282  LOG(INFO) << "All done. Successfully created delta file with "
1283            << "metadata size = " << *metadata_size;
1284  return true;
1285}
1286
1287// Runs the bsdiff tool on two files and returns the resulting delta in
1288// 'out'. Returns true on success.
1289bool DeltaDiffGenerator::BsdiffFiles(const string& old_file,
1290                                     const string& new_file,
1291                                     chromeos::Blob* out) {
1292  const string kPatchFile = "delta.patchXXXXXX";
1293  string patch_file_path;
1294
1295  TEST_AND_RETURN_FALSE(
1296      utils::MakeTempFile(kPatchFile, &patch_file_path, nullptr));
1297
1298  vector<string> cmd;
1299  cmd.push_back(kBsdiffPath);
1300  cmd.push_back(old_file);
1301  cmd.push_back(new_file);
1302  cmd.push_back(patch_file_path);
1303
1304  int rc = 1;
1305  chromeos::Blob patch_file;
1306  TEST_AND_RETURN_FALSE(Subprocess::SynchronousExec(cmd, &rc, nullptr));
1307  TEST_AND_RETURN_FALSE(rc == 0);
1308  TEST_AND_RETURN_FALSE(utils::ReadFile(patch_file_path, out));
1309  unlink(patch_file_path.c_str());
1310  return true;
1311}
1312
1313void DeltaDiffGenerator::AddSignatureOp(uint64_t signature_blob_offset,
1314                                        uint64_t signature_blob_length,
1315                                        DeltaArchiveManifest* manifest) {
1316  LOG(INFO) << "Making room for signature in file";
1317  manifest->set_signatures_offset(signature_blob_offset);
1318  LOG(INFO) << "set? " << manifest->has_signatures_offset();
1319  // Add a dummy op at the end to appease older clients
1320  DeltaArchiveManifest_InstallOperation* dummy_op =
1321      manifest->add_kernel_install_operations();
1322  dummy_op->set_type(DeltaArchiveManifest_InstallOperation_Type_REPLACE);
1323  dummy_op->set_data_offset(signature_blob_offset);
1324  manifest->set_signatures_offset(signature_blob_offset);
1325  dummy_op->set_data_length(signature_blob_length);
1326  manifest->set_signatures_size(signature_blob_length);
1327  Extent* dummy_extent = dummy_op->add_dst_extents();
1328  // Tell the dummy op to write this data to a big sparse hole
1329  dummy_extent->set_start_block(kSparseHole);
1330  dummy_extent->set_num_blocks((signature_blob_length + kBlockSize - 1) /
1331                               kBlockSize);
1332}
1333
1334};  // namespace chromeos_update_engine
1335