delta_diff_generator.cc revision cd514b531a38da1497630fa68b6e3ef45871893d 
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 kVersionNumber = 1;
57const uint64_t kFullUpdateChunkSize = 1024 * 1024;  // bytes
58
59// The maximum destination size allowed for bsdiff. In general, bsdiff should
60// work for arbitrary big files, but the payload generation and payload
61// application requires a significant amount of RAM. We put a hard-limit of
62// 200 MiB that should not affect any released board, but will limit the
63// Chrome binary in ASan builders.
64const off_t kMaxBsdiffDestinationSize = 200 * 1024 * 1024;  // bytes
65
66static const char* kInstallOperationTypes[] = {
67  "REPLACE",
68  "REPLACE_BZ",
69  "MOVE",
70  "BSDIFF",
71  "SOURCE_COPY",
72  "SOURCE_BSDIFF"
73};
74
75}  // namespace
76
77namespace chromeos_update_engine {
78
79typedef DeltaDiffGenerator::Block Block;
80typedef map<const DeltaArchiveManifest_InstallOperation*,
81            string> OperationNameMap;
82
83// bytes
84const size_t kRootFSPartitionSize = static_cast<size_t>(2) * 1024 * 1024 * 1024;
85const size_t kBlockSize = 4096;  // bytes
86const char* const kEmptyPath = "";
87const char* const kBsdiffPath = "bsdiff";
88
89// Needed for testing purposes, in case we can't use actual filesystem objects.
90// TODO(garnold) (chromium:331965) Replace this hack with a properly injected
91// parameter in form of a mockable abstract class.
92bool (*get_extents_with_chunk_func)(const string&, off_t, off_t,
93                                    vector<Extent>*) =
94    extent_mapper::ExtentsForFileChunkFibmap;
95
96namespace {
97
98// Stores all the extents of |path| into |extents|. Returns true on success.
99bool GatherExtents(const string& path,
100                   off_t chunk_offset,
101                   off_t chunk_size,
102                   vector<Extent>* extents) {
103  extents->clear();
104  TEST_AND_RETURN_FALSE(
105      get_extents_with_chunk_func(
106          path, chunk_offset, chunk_size, extents));
107  return true;
108}
109
110// For each regular file within new_root, creates a node in the graph,
111// determines the best way to compress it (REPLACE, REPLACE_BZ, COPY, BSDIFF),
112// and writes any necessary data to the end of data_fd.
113bool DeltaReadFiles(Graph* graph,
114                    vector<Block>* blocks,
115                    const string& old_root,
116                    const string& new_root,
117                    off_t chunk_size,
118                    int data_fd,
119                    off_t* data_file_size) {
120  set<ino_t> visited_inodes;
121  set<ino_t> visited_src_inodes;
122  for (FilesystemIterator fs_iter(new_root,
123                                  set<string>{"/lost+found"});
124       !fs_iter.IsEnd(); fs_iter.Increment()) {
125    // We never diff symlinks (here, we check that dst file is not a symlink).
126    if (!S_ISREG(fs_iter.GetStat().st_mode))
127      continue;
128
129    // Make sure we visit each inode only once.
130    if (utils::SetContainsKey(visited_inodes, fs_iter.GetStat().st_ino))
131      continue;
132    visited_inodes.insert(fs_iter.GetStat().st_ino);
133    off_t dst_size = fs_iter.GetFileSize();
134    if (dst_size == 0)
135      continue;
136
137    LOG(INFO) << "Encoding file " << fs_iter.GetPartialPath();
138
139    // We can't visit each dst image inode more than once, as that would
140    // duplicate work. Here, we avoid visiting each source image inode
141    // more than once. Technically, we could have multiple operations
142    // that read the same blocks from the source image for diffing, but
143    // we choose not to avoid complexity. Eventually we will move away
144    // from using a graph/cycle detection/etc to generate diffs, and at that
145    // time, it will be easy (non-complex) to have many operations read
146    // from the same source blocks. At that time, this code can die. -adlr
147    bool should_diff_from_source = false;
148    string src_path = old_root + fs_iter.GetPartialPath();
149    struct stat src_stbuf;
150    // We never diff symlinks (here, we check that src file is not a symlink).
151    if (0 == lstat(src_path.c_str(), &src_stbuf) &&
152        S_ISREG(src_stbuf.st_mode)) {
153      should_diff_from_source = !utils::SetContainsKey(visited_src_inodes,
154                                                       src_stbuf.st_ino);
155      visited_src_inodes.insert(src_stbuf.st_ino);
156    }
157
158    off_t size = chunk_size == -1 ? dst_size : chunk_size;
159    off_t step = size;
160    for (off_t offset = 0; offset < dst_size; offset += step) {
161      if (offset + size >= dst_size) {
162        size = -1;  // Read through the end of the file.
163      }
164      TEST_AND_RETURN_FALSE(DeltaDiffGenerator::DeltaReadFile(
165          graph,
166          Vertex::kInvalidIndex,
167          blocks,
168          (should_diff_from_source ? old_root : kEmptyPath),
169          new_root,
170          fs_iter.GetPartialPath(),
171          offset,
172          size,
173          data_fd,
174          data_file_size));
175    }
176  }
177  return true;
178}
179
180// Reads blocks from image_path that are not yet marked as being written in the
181// blocks array. These blocks that remain are either unchanged files or
182// non-file-data blocks.  We compare each of them to the old image, and compress
183// the ones that changed into a single REPLACE_BZ operation. This updates a
184// newly created node in the graph to write these blocks and writes the
185// appropriate blob to blobs_fd. Reads and updates blobs_length.
186bool ReadUnwrittenBlocks(const vector<Block>& blocks,
187                         int blobs_fd,
188                         off_t* blobs_length,
189                         const string& old_image_path,
190                         const string& new_image_path,
191                         Vertex* vertex) {
192  vertex->file_name = "<rootfs-non-file-data>";
193
194  DeltaArchiveManifest_InstallOperation* out_op = &vertex->op;
195  int new_image_fd = open(new_image_path.c_str(), O_RDONLY, 000);
196  TEST_AND_RETURN_FALSE_ERRNO(new_image_fd >= 0);
197  ScopedFdCloser new_image_fd_closer(&new_image_fd);
198  int old_image_fd = open(old_image_path.c_str(), O_RDONLY, 000);
199  TEST_AND_RETURN_FALSE_ERRNO(old_image_fd >= 0);
200  ScopedFdCloser old_image_fd_closer(&old_image_fd);
201
202  string temp_file_path;
203  TEST_AND_RETURN_FALSE(utils::MakeTempFile("CrAU_temp_data.XXXXXX",
204                                            &temp_file_path,
205                                            nullptr));
206
207  FILE* file = fopen(temp_file_path.c_str(), "w");
208  TEST_AND_RETURN_FALSE(file);
209  int err = BZ_OK;
210
211  BZFILE* bz_file = BZ2_bzWriteOpen(&err,
212                                    file,
213                                    9,  // max compression
214                                    0,  // verbosity
215                                    0);  // default work factor
216  TEST_AND_RETURN_FALSE(err == BZ_OK);
217
218  vector<Extent> extents;
219  vector<Block>::size_type block_count = 0;
220
221  LOG(INFO) << "Appending unwritten blocks to extents";
222  for (vector<Block>::size_type i = 0; i < blocks.size(); i++) {
223    if (blocks[i].writer != Vertex::kInvalidIndex)
224      continue;
225    graph_utils::AppendBlockToExtents(&extents, i);
226    block_count++;
227  }
228
229  // Code will handle buffers of any size that's a multiple of kBlockSize,
230  // so we arbitrarily set it to 1024 * kBlockSize.
231  chromeos::Blob new_buf(1024 * kBlockSize);
232  chromeos::Blob old_buf(1024 * kBlockSize);
233
234  LOG(INFO) << "Scanning " << block_count << " unwritten blocks";
235  vector<Extent> changed_extents;
236  vector<Block>::size_type changed_block_count = 0;
237  vector<Block>::size_type blocks_copied_count = 0;
238
239  // For each extent in extents, write the unchanged blocks into BZ2_bzWrite,
240  // which sends it to an output file.  We use the temporary buffers to hold the
241  // old and new data, which may be smaller than the extent, so in that case we
242  // have to loop to get the extent's data (that's the inner while loop).
243  for (const Extent& extent : extents) {
244    vector<Block>::size_type blocks_read = 0;
245    float printed_progress = -1;
246    while (blocks_read < extent.num_blocks()) {
247      const uint64_t copy_first_block = extent.start_block() + blocks_read;
248      const int copy_block_cnt =
249          min(new_buf.size() / kBlockSize,
250              static_cast<chromeos::Blob::size_type>(
251                  extent.num_blocks() - blocks_read));
252      const size_t count = copy_block_cnt * kBlockSize;
253      const off_t offset = copy_first_block * kBlockSize;
254      ssize_t rc = pread(new_image_fd, new_buf.data(), count, offset);
255      TEST_AND_RETURN_FALSE_ERRNO(rc >= 0);
256      TEST_AND_RETURN_FALSE(static_cast<size_t>(rc) == count);
257
258      rc = pread(old_image_fd, old_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      // Compare each block in the buffer to its counterpart in the old image
263      // and only compress it if its content has changed.
264      int buf_offset = 0;
265      for (int i = 0; i < copy_block_cnt; ++i) {
266        int buf_end_offset = buf_offset + kBlockSize;
267        if (!std::equal(new_buf.begin() + buf_offset,
268                        new_buf.begin() + buf_end_offset,
269                        old_buf.begin() + buf_offset)) {
270          BZ2_bzWrite(&err, bz_file, &new_buf[buf_offset], kBlockSize);
271          TEST_AND_RETURN_FALSE(err == BZ_OK);
272          const uint64_t block_idx = copy_first_block + i;
273          if (blocks[block_idx].reader != Vertex::kInvalidIndex) {
274            graph_utils::AddReadBeforeDep(vertex, blocks[block_idx].reader,
275                                          block_idx);
276          }
277          graph_utils::AppendBlockToExtents(&changed_extents, block_idx);
278          changed_block_count++;
279        }
280        buf_offset = buf_end_offset;
281      }
282
283      blocks_read += copy_block_cnt;
284      blocks_copied_count += copy_block_cnt;
285      float current_progress =
286          static_cast<float>(blocks_copied_count) / block_count;
287      if (printed_progress + 0.1 < current_progress ||
288          blocks_copied_count == block_count) {
289        LOG(INFO) << "progress: " << current_progress;
290        printed_progress = current_progress;
291      }
292    }
293  }
294  BZ2_bzWriteClose(&err, bz_file, 0, nullptr, nullptr);
295  TEST_AND_RETURN_FALSE(err == BZ_OK);
296  bz_file = nullptr;
297  TEST_AND_RETURN_FALSE_ERRNO(0 == fclose(file));
298  file = nullptr;
299
300  LOG(INFO) << "Compressed " << changed_block_count << " blocks ("
301            << block_count - changed_block_count << " blocks unchanged)";
302  chromeos::Blob compressed_data;
303  if (changed_block_count > 0) {
304    LOG(INFO) << "Reading compressed data off disk";
305    TEST_AND_RETURN_FALSE(utils::ReadFile(temp_file_path, &compressed_data));
306  }
307  TEST_AND_RETURN_FALSE(unlink(temp_file_path.c_str()) == 0);
308
309  // Add node to graph to write these blocks
310  out_op->set_type(DeltaArchiveManifest_InstallOperation_Type_REPLACE_BZ);
311  out_op->set_data_offset(*blobs_length);
312  out_op->set_data_length(compressed_data.size());
313  LOG(INFO) << "Rootfs non-data blocks compressed take up "
314            << compressed_data.size();
315  *blobs_length += compressed_data.size();
316  out_op->set_dst_length(kBlockSize * changed_block_count);
317  DeltaDiffGenerator::StoreExtents(changed_extents,
318                                   out_op->mutable_dst_extents());
319
320  TEST_AND_RETURN_FALSE(utils::WriteAll(blobs_fd,
321                                        compressed_data.data(),
322                                        compressed_data.size()));
323  LOG(INFO) << "Done processing unwritten blocks";
324  return true;
325}
326
327// Writes the uint64_t passed in in host-endian to the file as big-endian.
328// Returns true on success.
329bool WriteUint64AsBigEndian(FileWriter* writer, const uint64_t value) {
330  uint64_t value_be = htobe64(value);
331  TEST_AND_RETURN_FALSE(writer->Write(&value_be, sizeof(value_be)));
332  return true;
333}
334
335// Adds each operation from |graph| to |out_manifest| in the order specified by
336// |order| while building |out_op_name_map| with operation to name
337// mappings. Adds all |kernel_ops| to |out_manifest|. Filters out no-op
338// operations.
339void InstallOperationsToManifest(
340    const Graph& graph,
341    const vector<Vertex::Index>& order,
342    const vector<DeltaArchiveManifest_InstallOperation>& kernel_ops,
343    DeltaArchiveManifest* out_manifest,
344    OperationNameMap* out_op_name_map) {
345  for (Vertex::Index vertex_index : order) {
346    const Vertex& vertex = graph[vertex_index];
347    const DeltaArchiveManifest_InstallOperation& add_op = vertex.op;
348    if (DeltaDiffGenerator::IsNoopOperation(add_op)) {
349      continue;
350    }
351    DeltaArchiveManifest_InstallOperation* op =
352        out_manifest->add_install_operations();
353    *op = add_op;
354    string name = vertex.file_name;
355    if (vertex.chunk_offset || vertex.chunk_size != -1) {
356      string offset = base::Int64ToString(vertex.chunk_offset);
357      if (vertex.chunk_size != -1) {
358        name += " [" + offset + ", " +
359            base::Int64ToString(vertex.chunk_offset + vertex.chunk_size - 1) +
360            "]";
361      } else {
362        name += " [" + offset + ", end]";
363      }
364    }
365    (*out_op_name_map)[op] = name;
366  }
367  for (vector<DeltaArchiveManifest_InstallOperation>::const_iterator it =
368           kernel_ops.begin(); it != kernel_ops.end(); ++it) {
369    const DeltaArchiveManifest_InstallOperation& add_op = *it;
370    if (DeltaDiffGenerator::IsNoopOperation(add_op)) {
371      continue;
372    }
373    DeltaArchiveManifest_InstallOperation* op =
374        out_manifest->add_kernel_install_operations();
375    *op = add_op;
376  }
377}
378
379// Delta compresses a kernel partition |new_kernel_part| with knowledge of the
380// old kernel partition |old_kernel_part|. If |old_kernel_part| is an empty
381// string, generates a full update of the partition.
382bool DeltaCompressKernelPartition(
383    const string& old_kernel_part,
384    const string& new_kernel_part,
385    vector<DeltaArchiveManifest_InstallOperation>* ops,
386    int blobs_fd,
387    off_t* blobs_length) {
388  LOG(INFO) << "Delta compressing kernel partition...";
389  LOG_IF(INFO, old_kernel_part.empty()) << "Generating full kernel update...";
390
391  DeltaArchiveManifest_InstallOperation op;
392  chromeos::Blob data;
393  TEST_AND_RETURN_FALSE(
394      DeltaDiffGenerator::ReadFileToDiff(old_kernel_part,
395                                         new_kernel_part,
396                                         0,  // chunk_offset
397                                         -1,  // chunk_size
398                                         true,  // bsdiff_allowed
399                                         &data,
400                                         &op,
401                                         false));
402
403  // Check if the operation writes nothing.
404  if (op.dst_extents_size() == 0) {
405    if (op.type() == DeltaArchiveManifest_InstallOperation_Type_MOVE) {
406      LOG(INFO) << "Empty MOVE operation, nothing to do.";
407      return true;
408    } else {
409      LOG(ERROR) << "Empty non-MOVE operation";
410      return false;
411    }
412  }
413
414  // Write the data.
415  if (op.type() != DeltaArchiveManifest_InstallOperation_Type_MOVE) {
416    op.set_data_offset(*blobs_length);
417    op.set_data_length(data.size());
418  }
419
420  // Add the new install operation.
421  ops->clear();
422  ops->push_back(op);
423
424  TEST_AND_RETURN_FALSE(utils::WriteAll(blobs_fd, data.data(), data.size()));
425  *blobs_length += data.size();
426
427  LOG(INFO) << "Done delta compressing kernel partition: "
428            << kInstallOperationTypes[op.type()];
429  return true;
430}
431
432struct DeltaObject {
433  DeltaObject(const string& in_name, const int in_type, const off_t in_size)
434      : name(in_name),
435        type(in_type),
436        size(in_size) {}
437  bool operator <(const DeltaObject& object) const {
438    return (size != object.size) ? (size < object.size) : (name < object.name);
439  }
440  string name;
441  int type;
442  off_t size;
443};
444
445void ReportPayloadUsage(const DeltaArchiveManifest& manifest,
446                        const int64_t manifest_metadata_size,
447                        const OperationNameMap& op_name_map) {
448  vector<DeltaObject> objects;
449  off_t total_size = 0;
450
451  // Rootfs install operations.
452  for (int i = 0; i < manifest.install_operations_size(); ++i) {
453    const DeltaArchiveManifest_InstallOperation& op =
454        manifest.install_operations(i);
455    objects.push_back(DeltaObject(op_name_map.find(&op)->second,
456                                  op.type(),
457                                  op.data_length()));
458    total_size += op.data_length();
459  }
460
461  // Kernel install operations.
462  for (int i = 0; i < manifest.kernel_install_operations_size(); ++i) {
463    const DeltaArchiveManifest_InstallOperation& op =
464        manifest.kernel_install_operations(i);
465    objects.push_back(DeltaObject(base::StringPrintf("<kernel-operation-%d>",
466                                                     i),
467                                  op.type(),
468                                  op.data_length()));
469    total_size += op.data_length();
470  }
471
472  objects.push_back(DeltaObject("<manifest-metadata>",
473                                -1,
474                                manifest_metadata_size));
475  total_size += manifest_metadata_size;
476
477  std::sort(objects.begin(), objects.end());
478
479  static const char kFormatString[] = "%6.2f%% %10jd %-10s %s\n";
480  for (const DeltaObject& object : objects) {
481    fprintf(stderr, kFormatString,
482            object.size * 100.0 / total_size,
483            static_cast<intmax_t>(object.size),
484            object.type >= 0 ? kInstallOperationTypes[object.type] : "-",
485            object.name.c_str());
486  }
487  fprintf(stderr, kFormatString,
488          100.0, static_cast<intmax_t>(total_size), "", "<total>");
489}
490
491// Process a range of blocks from |range_start| to |range_end| in the extent at
492// position |*idx_p| of |extents|. If |do_remove| is true, this range will be
493// removed, which may cause the extent to be trimmed, split or removed entirely.
494// The value of |*idx_p| is updated to point to the next extent to be processed.
495// Returns true iff the next extent to process is a new or updated one.
496bool ProcessExtentBlockRange(vector<Extent>* extents, size_t* idx_p,
497                             const bool do_remove, uint64_t range_start,
498                             uint64_t range_end) {
499  size_t idx = *idx_p;
500  uint64_t start_block = (*extents)[idx].start_block();
501  uint64_t num_blocks = (*extents)[idx].num_blocks();
502  uint64_t range_size = range_end - range_start;
503
504  if (do_remove) {
505    if (range_size == num_blocks) {
506      // Remove the entire extent.
507      extents->erase(extents->begin() + idx);
508    } else if (range_end == num_blocks) {
509      // Trim the end of the extent.
510      (*extents)[idx].set_num_blocks(num_blocks - range_size);
511      idx++;
512    } else if (range_start == 0) {
513      // Trim the head of the extent.
514      (*extents)[idx].set_start_block(start_block + range_size);
515      (*extents)[idx].set_num_blocks(num_blocks - range_size);
516    } else {
517      // Trim the middle, splitting the remainder into two parts.
518      (*extents)[idx].set_num_blocks(range_start);
519      Extent e;
520      e.set_start_block(start_block + range_end);
521      e.set_num_blocks(num_blocks - range_end);
522      idx++;
523      extents->insert(extents->begin() + idx, e);
524    }
525  } else if (range_end == num_blocks) {
526    // Done with this extent.
527    idx++;
528  } else {
529    return false;
530  }
531
532  *idx_p = idx;
533  return true;
534}
535
536// Remove identical corresponding block ranges in |src_extents| and
537// |dst_extents|. Used for preventing moving of blocks onto themselves during
538// MOVE operations. The value of |total_bytes| indicates the actual length of
539// content; this may be slightly less than the total size of blocks, in which
540// case the last block is only partly occupied with data. Returns the total
541// number of bytes removed.
542size_t RemoveIdenticalBlockRanges(vector<Extent>* src_extents,
543                                  vector<Extent>* dst_extents,
544                                  const size_t total_bytes) {
545  size_t src_idx = 0;
546  size_t dst_idx = 0;
547  uint64_t src_offset = 0, dst_offset = 0;
548  bool new_src = true, new_dst = true;
549  size_t removed_bytes = 0, nonfull_block_bytes;
550  bool do_remove = false;
551  while (src_idx < src_extents->size() && dst_idx < dst_extents->size()) {
552    if (new_src) {
553      src_offset = 0;
554      new_src = false;
555    }
556    if (new_dst) {
557      dst_offset = 0;
558      new_dst = false;
559    }
560
561    do_remove = ((*src_extents)[src_idx].start_block() + src_offset ==
562                 (*dst_extents)[dst_idx].start_block() + dst_offset);
563
564    uint64_t src_num_blocks = (*src_extents)[src_idx].num_blocks();
565    uint64_t dst_num_blocks = (*dst_extents)[dst_idx].num_blocks();
566    uint64_t min_num_blocks = min(src_num_blocks - src_offset,
567                                  dst_num_blocks - dst_offset);
568    uint64_t prev_src_offset = src_offset;
569    uint64_t prev_dst_offset = dst_offset;
570    src_offset += min_num_blocks;
571    dst_offset += min_num_blocks;
572
573    new_src = ProcessExtentBlockRange(src_extents, &src_idx, do_remove,
574                                      prev_src_offset, src_offset);
575    new_dst = ProcessExtentBlockRange(dst_extents, &dst_idx, do_remove,
576                                      prev_dst_offset, dst_offset);
577    if (do_remove)
578      removed_bytes += min_num_blocks * kBlockSize;
579  }
580
581  // If we removed the last block and this block is only partly used by file
582  // content, deduct the unused portion from the total removed byte count.
583  if (do_remove && (nonfull_block_bytes = total_bytes % kBlockSize))
584    removed_bytes -= kBlockSize - nonfull_block_bytes;
585
586  return removed_bytes;
587}
588
589}  // namespace
590
591void DeltaDiffGenerator::CheckGraph(const Graph& graph) {
592  for (const Vertex& v : graph) {
593    CHECK(v.op.has_type());
594  }
595}
596
597bool DeltaDiffGenerator::DeltaReadFile(Graph* graph,
598                                       Vertex::Index existing_vertex,
599                                       vector<Block>* blocks,
600                                       const string& old_root,
601                                       const string& new_root,
602                                       const string& path,  // within new_root
603                                       off_t chunk_offset,
604                                       off_t chunk_size,
605                                       int data_fd,
606                                       off_t* data_file_size) {
607  chromeos::Blob data;
608  DeltaArchiveManifest_InstallOperation operation;
609
610  string old_path = (old_root == kEmptyPath) ? kEmptyPath :
611      old_root + path;
612
613  // If bsdiff breaks again, blacklist the problem file by using:
614  //   bsdiff_allowed = (path != "/foo/bar")
615  //
616  // TODO(dgarrett): chromium-os:15274 connect this test to the command line.
617  bool bsdiff_allowed = true;
618
619  if (utils::FileSize(new_root + path) > kMaxBsdiffDestinationSize)
620    bsdiff_allowed = false;
621
622  if (!bsdiff_allowed)
623    LOG(INFO) << "bsdiff blacklisting: " << path;
624
625  TEST_AND_RETURN_FALSE(DeltaDiffGenerator::ReadFileToDiff(old_path,
626                                                           new_root + path,
627                                                           chunk_offset,
628                                                           chunk_size,
629                                                           bsdiff_allowed,
630                                                           &data,
631                                                           &operation,
632                                                           true));
633
634  // Check if the operation writes nothing.
635  if (operation.dst_extents_size() == 0) {
636    if (operation.type() == DeltaArchiveManifest_InstallOperation_Type_MOVE) {
637      LOG(INFO) << "Empty MOVE operation (" << new_root + path << "), skipping";
638      return true;
639    } else {
640      LOG(ERROR) << "Empty non-MOVE operation";
641      return false;
642    }
643  }
644
645  // Write the data
646  if (operation.type() != DeltaArchiveManifest_InstallOperation_Type_MOVE) {
647    operation.set_data_offset(*data_file_size);
648    operation.set_data_length(data.size());
649  }
650
651  TEST_AND_RETURN_FALSE(utils::WriteAll(data_fd, data.data(), data.size()));
652  *data_file_size += data.size();
653
654  // Now, insert into graph and blocks vector
655  Vertex::Index vertex = existing_vertex;
656  if (vertex == Vertex::kInvalidIndex) {
657    graph->resize(graph->size() + 1);
658    vertex = graph->size() - 1;
659  }
660  (*graph)[vertex].op = operation;
661  CHECK((*graph)[vertex].op.has_type());
662  (*graph)[vertex].file_name = path;
663  (*graph)[vertex].chunk_offset = chunk_offset;
664  (*graph)[vertex].chunk_size = chunk_size;
665
666  if (blocks)
667    TEST_AND_RETURN_FALSE(InplaceGenerator::AddInstallOpToBlocksVector(
668        (*graph)[vertex].op,
669        *graph,
670        vertex,
671        blocks));
672  return true;
673}
674
675
676bool DeltaDiffGenerator::ReadFileToDiff(
677    const string& old_filename,
678    const string& new_filename,
679    off_t chunk_offset,
680    off_t chunk_size,
681    bool bsdiff_allowed,
682    chromeos::Blob* out_data,
683    DeltaArchiveManifest_InstallOperation* out_op,
684    bool gather_extents) {
685  // Read new data in
686  chromeos::Blob new_data;
687  TEST_AND_RETURN_FALSE(
688      utils::ReadFileChunk(new_filename, chunk_offset, chunk_size, &new_data));
689
690  TEST_AND_RETURN_FALSE(!new_data.empty());
691  TEST_AND_RETURN_FALSE(chunk_size == -1 ||
692                        static_cast<off_t>(new_data.size()) <= chunk_size);
693
694  chromeos::Blob new_data_bz;
695  TEST_AND_RETURN_FALSE(BzipCompress(new_data, &new_data_bz));
696  CHECK(!new_data_bz.empty());
697
698  chromeos::Blob data;  // Data blob that will be written to delta file.
699
700  DeltaArchiveManifest_InstallOperation operation;
701  size_t current_best_size = 0;
702  if (new_data.size() <= new_data_bz.size()) {
703    operation.set_type(DeltaArchiveManifest_InstallOperation_Type_REPLACE);
704    current_best_size = new_data.size();
705    data = new_data;
706  } else {
707    operation.set_type(DeltaArchiveManifest_InstallOperation_Type_REPLACE_BZ);
708    current_best_size = new_data_bz.size();
709    data = new_data_bz;
710  }
711
712  // Do we have an original file to consider?
713  off_t old_size = 0;
714  bool original = !old_filename.empty();
715  if (original && (old_size = utils::FileSize(old_filename)) < 0) {
716    // If stat-ing the old file fails, it should be because it doesn't exist.
717    TEST_AND_RETURN_FALSE(!utils::FileExists(old_filename.c_str()));
718    original = false;
719  }
720
721  chromeos::Blob old_data;
722  if (original) {
723    // Read old data
724    TEST_AND_RETURN_FALSE(
725        utils::ReadFileChunk(
726            old_filename, chunk_offset, chunk_size, &old_data));
727    if (old_data == new_data) {
728      // No change in data.
729      operation.set_type(DeltaArchiveManifest_InstallOperation_Type_MOVE);
730      current_best_size = 0;
731      data.clear();
732    } else if (!old_data.empty() && bsdiff_allowed) {
733      // If the source file is considered bsdiff safe (no bsdiff bugs
734      // triggered), see if BSDIFF encoding is smaller.
735      base::FilePath old_chunk;
736      TEST_AND_RETURN_FALSE(base::CreateTemporaryFile(&old_chunk));
737      ScopedPathUnlinker old_unlinker(old_chunk.value());
738      TEST_AND_RETURN_FALSE(
739          utils::WriteFile(old_chunk.value().c_str(),
740                           old_data.data(), old_data.size()));
741      base::FilePath new_chunk;
742      TEST_AND_RETURN_FALSE(base::CreateTemporaryFile(&new_chunk));
743      ScopedPathUnlinker new_unlinker(new_chunk.value());
744      TEST_AND_RETURN_FALSE(
745          utils::WriteFile(new_chunk.value().c_str(),
746                           new_data.data(), new_data.size()));
747
748      chromeos::Blob bsdiff_delta;
749      TEST_AND_RETURN_FALSE(
750          BsdiffFiles(old_chunk.value(), new_chunk.value(), &bsdiff_delta));
751      CHECK_GT(bsdiff_delta.size(), static_cast<chromeos::Blob::size_type>(0));
752      if (bsdiff_delta.size() < current_best_size) {
753        operation.set_type(DeltaArchiveManifest_InstallOperation_Type_BSDIFF);
754        current_best_size = bsdiff_delta.size();
755        data = bsdiff_delta;
756      }
757    }
758  }
759
760  // Set parameters of the operations
761  CHECK_EQ(data.size(), current_best_size);
762
763  vector<Extent> src_extents, dst_extents;
764  if (operation.type() == DeltaArchiveManifest_InstallOperation_Type_MOVE ||
765      operation.type() == DeltaArchiveManifest_InstallOperation_Type_BSDIFF) {
766    if (gather_extents) {
767      TEST_AND_RETURN_FALSE(
768          GatherExtents(old_filename,
769                        chunk_offset,
770                        chunk_size,
771                        &src_extents));
772    } else {
773      Extent* src_extent = operation.add_src_extents();
774      src_extent->set_start_block(0);
775      src_extent->set_num_blocks((old_size + kBlockSize - 1) / kBlockSize);
776    }
777    operation.set_src_length(old_data.size());
778  }
779
780  if (gather_extents) {
781    TEST_AND_RETURN_FALSE(
782        GatherExtents(new_filename,
783                      chunk_offset,
784                      chunk_size,
785                      &dst_extents));
786  } else {
787    Extent* dst_extent = operation.add_dst_extents();
788    dst_extent->set_start_block(0);
789    dst_extent->set_num_blocks((new_data.size() + kBlockSize - 1) / kBlockSize);
790  }
791  operation.set_dst_length(new_data.size());
792
793  if (gather_extents) {
794    // Remove identical src/dst block ranges in MOVE operations.
795    if (operation.type() == DeltaArchiveManifest_InstallOperation_Type_MOVE) {
796      size_t removed_bytes = RemoveIdenticalBlockRanges(
797          &src_extents, &dst_extents, new_data.size());
798
799      // Adjust the file length field accordingly.
800      if (removed_bytes) {
801        operation.set_src_length(old_data.size() - removed_bytes);
802        operation.set_dst_length(new_data.size() - removed_bytes);
803      }
804    }
805
806    // Embed extents in the operation.
807    DeltaDiffGenerator::StoreExtents(src_extents,
808                                     operation.mutable_src_extents());
809    DeltaDiffGenerator::StoreExtents(dst_extents,
810                                     operation.mutable_dst_extents());
811  }
812
813  out_data->swap(data);
814  *out_op = operation;
815
816  return true;
817}
818
819bool DeltaDiffGenerator::InitializePartitionInfo(bool is_kernel,
820                                                 const string& partition,
821                                                 PartitionInfo* info) {
822  int64_t size = 0;
823  if (is_kernel) {
824    size = utils::FileSize(partition);
825  } else {
826    int block_count = 0, block_size = 0;
827    TEST_AND_RETURN_FALSE(utils::GetFilesystemSize(partition,
828                                                   &block_count,
829                                                   &block_size));
830    size = static_cast<int64_t>(block_count) * block_size;
831  }
832  TEST_AND_RETURN_FALSE(size > 0);
833  info->set_size(size);
834  OmahaHashCalculator hasher;
835  TEST_AND_RETURN_FALSE(hasher.UpdateFile(partition, size) == size);
836  TEST_AND_RETURN_FALSE(hasher.Finalize());
837  const chromeos::Blob& hash = hasher.raw_hash();
838  info->set_hash(hash.data(), hash.size());
839  LOG(INFO) << partition << ": size=" << size << " hash=" << hasher.hash();
840  return true;
841}
842
843bool InitializePartitionInfos(const string& old_kernel,
844                              const string& new_kernel,
845                              const string& old_rootfs,
846                              const string& new_rootfs,
847                              DeltaArchiveManifest* manifest) {
848  if (!old_kernel.empty()) {
849    TEST_AND_RETURN_FALSE(DeltaDiffGenerator::InitializePartitionInfo(
850        true,
851        old_kernel,
852        manifest->mutable_old_kernel_info()));
853  }
854  TEST_AND_RETURN_FALSE(DeltaDiffGenerator::InitializePartitionInfo(
855      true,
856      new_kernel,
857      manifest->mutable_new_kernel_info()));
858  if (!old_rootfs.empty()) {
859    TEST_AND_RETURN_FALSE(DeltaDiffGenerator::InitializePartitionInfo(
860        false,
861        old_rootfs,
862        manifest->mutable_old_rootfs_info()));
863  }
864  TEST_AND_RETURN_FALSE(DeltaDiffGenerator::InitializePartitionInfo(
865      false,
866      new_rootfs,
867      manifest->mutable_new_rootfs_info()));
868  return true;
869}
870
871// Stores all Extents in 'extents' into 'out'.
872void DeltaDiffGenerator::StoreExtents(
873    const vector<Extent>& extents,
874    google::protobuf::RepeatedPtrField<Extent>* out) {
875  for (const Extent& extent : extents) {
876    Extent* new_extent = out->Add();
877    *new_extent = extent;
878  }
879}
880
881// Returns true if |op| is a no-op operation that doesn't do any useful work
882// (e.g., a move operation that copies blocks onto themselves).
883bool DeltaDiffGenerator::IsNoopOperation(
884    const DeltaArchiveManifest_InstallOperation& op) {
885  return (op.type() == DeltaArchiveManifest_InstallOperation_Type_MOVE &&
886          ExpandExtents(op.src_extents()) == ExpandExtents(op.dst_extents()));
887}
888
889bool DeltaDiffGenerator::ReorderDataBlobs(
890    DeltaArchiveManifest* manifest,
891    const string& data_blobs_path,
892    const string& new_data_blobs_path) {
893  int in_fd = open(data_blobs_path.c_str(), O_RDONLY, 0);
894  TEST_AND_RETURN_FALSE_ERRNO(in_fd >= 0);
895  ScopedFdCloser in_fd_closer(&in_fd);
896
897  DirectFileWriter writer;
898  TEST_AND_RETURN_FALSE(
899      writer.Open(new_data_blobs_path.c_str(),
900                  O_WRONLY | O_TRUNC | O_CREAT,
901                  0644) == 0);
902  ScopedFileWriterCloser writer_closer(&writer);
903  uint64_t out_file_size = 0;
904
905  for (int i = 0; i < (manifest->install_operations_size() +
906                       manifest->kernel_install_operations_size()); i++) {
907    DeltaArchiveManifest_InstallOperation* op = nullptr;
908    if (i < manifest->install_operations_size()) {
909      op = manifest->mutable_install_operations(i);
910    } else {
911      op = manifest->mutable_kernel_install_operations(
912          i - manifest->install_operations_size());
913    }
914    if (!op->has_data_offset())
915      continue;
916    CHECK(op->has_data_length());
917    chromeos::Blob buf(op->data_length());
918    ssize_t rc = pread(in_fd, buf.data(), buf.size(), op->data_offset());
919    TEST_AND_RETURN_FALSE(rc == static_cast<ssize_t>(buf.size()));
920
921    // Add the hash of the data blobs for this operation
922    TEST_AND_RETURN_FALSE(AddOperationHash(op, buf));
923
924    op->set_data_offset(out_file_size);
925    TEST_AND_RETURN_FALSE(writer.Write(buf.data(), buf.size()));
926    out_file_size += buf.size();
927  }
928  return true;
929}
930
931bool DeltaDiffGenerator::AddOperationHash(
932    DeltaArchiveManifest_InstallOperation* op,
933    const chromeos::Blob& buf) {
934  OmahaHashCalculator hasher;
935
936  TEST_AND_RETURN_FALSE(hasher.Update(buf.data(), buf.size()));
937  TEST_AND_RETURN_FALSE(hasher.Finalize());
938
939  const chromeos::Blob& hash = hasher.raw_hash();
940  op->set_data_sha256_hash(hash.data(), hash.size());
941  return true;
942}
943
944bool DeltaDiffGenerator::GenerateDeltaUpdateFile(
945    const string& old_root,
946    const string& old_image,
947    const string& new_root,
948    const string& new_image,
949    const string& old_kernel_part,
950    const string& new_kernel_part,
951    const string& output_path,
952    const string& private_key_path,
953    off_t chunk_size,
954    size_t rootfs_partition_size,
955    uint32_t minor_version,
956    const ImageInfo* old_image_info,
957    const ImageInfo* new_image_info,
958    uint64_t* metadata_size) {
959  TEST_AND_RETURN_FALSE(chunk_size == -1 || chunk_size % kBlockSize == 0);
960  int old_image_block_count = 0, old_image_block_size = 0;
961  int new_image_block_count = 0, new_image_block_size = 0;
962  TEST_AND_RETURN_FALSE(utils::GetFilesystemSize(new_image,
963                                                 &new_image_block_count,
964                                                 &new_image_block_size));
965  if (!old_image.empty()) {
966    TEST_AND_RETURN_FALSE(utils::GetFilesystemSize(old_image,
967                                                   &old_image_block_count,
968                                                   &old_image_block_size));
969    TEST_AND_RETURN_FALSE(old_image_block_size == new_image_block_size);
970    LOG_IF(WARNING, old_image_block_count != new_image_block_count)
971        << "Old and new images have different block counts.";
972
973    // If new_image_info is present, old_image_info must be present.
974    TEST_AND_RETURN_FALSE(!old_image_info == !new_image_info);
975  } else {
976    // old_image_info must not be present for a full update.
977    TEST_AND_RETURN_FALSE(!old_image_info);
978  }
979
980  // Sanity checks for the partition size.
981  TEST_AND_RETURN_FALSE(rootfs_partition_size % kBlockSize == 0);
982  size_t fs_size = static_cast<size_t>(new_image_block_size) *
983                   new_image_block_count;
984  LOG(INFO) << "Rootfs partition size: " << rootfs_partition_size;
985  LOG(INFO) << "Actual filesystem size: " << fs_size;
986  TEST_AND_RETURN_FALSE(rootfs_partition_size >= fs_size);
987
988  // Sanity check kernel partition arg
989  TEST_AND_RETURN_FALSE(utils::FileSize(new_kernel_part) >= 0);
990
991  vector<Block> blocks(max(old_image_block_count, new_image_block_count));
992  LOG(INFO) << "Invalid block index: " << Vertex::kInvalidIndex;
993  LOG(INFO) << "Block count: " << blocks.size();
994  for (vector<Block>::size_type i = 0; i < blocks.size(); i++) {
995    CHECK(blocks[i].reader == Vertex::kInvalidIndex);
996    CHECK(blocks[i].writer == Vertex::kInvalidIndex);
997  }
998  Graph graph;
999  CheckGraph(graph);
1000
1001  const string kTempFileTemplate("CrAU_temp_data.XXXXXX");
1002  string temp_file_path;
1003  unique_ptr<ScopedPathUnlinker> temp_file_unlinker;
1004  off_t data_file_size = 0;
1005
1006  LOG(INFO) << "Reading files...";
1007
1008  // Create empty protobuf Manifest object
1009  DeltaArchiveManifest manifest;
1010
1011  vector<DeltaArchiveManifest_InstallOperation> kernel_ops;
1012
1013  vector<Vertex::Index> final_order;
1014  Vertex::Index scratch_vertex = Vertex::kInvalidIndex;
1015  {
1016    int fd;
1017    TEST_AND_RETURN_FALSE(
1018        utils::MakeTempFile(kTempFileTemplate, &temp_file_path, &fd));
1019    temp_file_unlinker.reset(new ScopedPathUnlinker(temp_file_path));
1020    TEST_AND_RETURN_FALSE(fd >= 0);
1021    ScopedFdCloser fd_closer(&fd);
1022    if (!old_image.empty()) {
1023      // Delta update
1024
1025      // Set the minor version for this payload.
1026      LOG(INFO) << "Adding Delta Minor Version.";
1027      manifest.set_minor_version(minor_version);
1028
1029      TEST_AND_RETURN_FALSE(DeltaReadFiles(&graph,
1030                                           &blocks,
1031                                           old_root,
1032                                           new_root,
1033                                           chunk_size,
1034                                           fd,
1035                                           &data_file_size));
1036      LOG(INFO) << "done reading normal files";
1037      CheckGraph(graph);
1038
1039      LOG(INFO) << "Starting metadata processing";
1040      TEST_AND_RETURN_FALSE(Metadata::DeltaReadMetadata(&graph,
1041                                                        &blocks,
1042                                                        old_image,
1043                                                        new_image,
1044                                                        fd,
1045                                                        &data_file_size));
1046      LOG(INFO) << "Done metadata processing";
1047      CheckGraph(graph);
1048
1049      graph.resize(graph.size() + 1);
1050      TEST_AND_RETURN_FALSE(ReadUnwrittenBlocks(blocks,
1051                                                fd,
1052                                                &data_file_size,
1053                                                old_image,
1054                                                new_image,
1055                                                &graph.back()));
1056      if (graph.back().op.data_length() == 0) {
1057        LOG(INFO) << "No unwritten blocks to write, omitting operation";
1058        graph.pop_back();
1059      }
1060
1061      // Final scratch block (if there's space)
1062      if (blocks.size() < (rootfs_partition_size / kBlockSize)) {
1063        scratch_vertex = graph.size();
1064        graph.resize(graph.size() + 1);
1065        InplaceGenerator::CreateScratchNode(
1066            blocks.size(),
1067            (rootfs_partition_size / kBlockSize) - blocks.size(),
1068            &graph.back());
1069      }
1070
1071      // Read kernel partition
1072      TEST_AND_RETURN_FALSE(DeltaCompressKernelPartition(old_kernel_part,
1073                                                         new_kernel_part,
1074                                                         &kernel_ops,
1075                                                         fd,
1076                                                         &data_file_size));
1077
1078      LOG(INFO) << "done reading kernel";
1079      CheckGraph(graph);
1080
1081      LOG(INFO) << "Creating edges...";
1082      InplaceGenerator::CreateEdges(&graph, blocks);
1083      LOG(INFO) << "Done creating edges";
1084      CheckGraph(graph);
1085
1086      TEST_AND_RETURN_FALSE(InplaceGenerator::ConvertGraphToDag(
1087          &graph,
1088          new_root,
1089          fd,
1090          &data_file_size,
1091          &final_order,
1092          scratch_vertex));
1093    } else {
1094      // Full update
1095      off_t new_image_size =
1096          static_cast<off_t>(new_image_block_count) * new_image_block_size;
1097      TEST_AND_RETURN_FALSE(FullUpdateGenerator::Run(&graph,
1098                                                     new_kernel_part,
1099                                                     new_image,
1100                                                     new_image_size,
1101                                                     fd,
1102                                                     &data_file_size,
1103                                                     kFullUpdateChunkSize,
1104                                                     kBlockSize,
1105                                                     &kernel_ops,
1106                                                     &final_order));
1107
1108      // Set the minor version for this payload.
1109      LOG(INFO) << "Adding Full Minor Version.";
1110      manifest.set_minor_version(DeltaPerformer::kFullPayloadMinorVersion);
1111    }
1112  }
1113
1114  if (old_image_info)
1115    *(manifest.mutable_old_image_info()) = *old_image_info;
1116
1117  if (new_image_info)
1118    *(manifest.mutable_new_image_info()) = *new_image_info;
1119
1120  OperationNameMap op_name_map;
1121  CheckGraph(graph);
1122  InstallOperationsToManifest(graph,
1123                              final_order,
1124                              kernel_ops,
1125                              &manifest,
1126                              &op_name_map);
1127  CheckGraph(graph);
1128  manifest.set_block_size(kBlockSize);
1129
1130  // Reorder the data blobs with the newly ordered manifest
1131  string ordered_blobs_path;
1132  TEST_AND_RETURN_FALSE(utils::MakeTempFile(
1133      "CrAU_temp_data.ordered.XXXXXX",
1134      &ordered_blobs_path,
1135      nullptr));
1136  ScopedPathUnlinker ordered_blobs_unlinker(ordered_blobs_path);
1137  TEST_AND_RETURN_FALSE(ReorderDataBlobs(&manifest,
1138                                         temp_file_path,
1139                                         ordered_blobs_path));
1140  temp_file_unlinker.reset();
1141
1142  // Check that install op blobs are in order.
1143  uint64_t next_blob_offset = 0;
1144  {
1145    for (int i = 0; i < (manifest.install_operations_size() +
1146                         manifest.kernel_install_operations_size()); i++) {
1147      DeltaArchiveManifest_InstallOperation* op =
1148          i < manifest.install_operations_size() ?
1149          manifest.mutable_install_operations(i) :
1150          manifest.mutable_kernel_install_operations(
1151              i - manifest.install_operations_size());
1152      if (op->has_data_offset()) {
1153        if (op->data_offset() != next_blob_offset) {
1154          LOG(FATAL) << "bad blob offset! " << op->data_offset() << " != "
1155                     << next_blob_offset;
1156        }
1157        next_blob_offset += op->data_length();
1158      }
1159    }
1160  }
1161
1162  // Signatures appear at the end of the blobs. Note the offset in the
1163  // manifest
1164  if (!private_key_path.empty()) {
1165    uint64_t signature_blob_length = 0;
1166    TEST_AND_RETURN_FALSE(
1167        PayloadSigner::SignatureBlobLength(vector<string>(1, private_key_path),
1168                                           &signature_blob_length));
1169    AddSignatureOp(next_blob_offset, signature_blob_length, &manifest);
1170  }
1171
1172  TEST_AND_RETURN_FALSE(InitializePartitionInfos(old_kernel_part,
1173                                                 new_kernel_part,
1174                                                 old_image,
1175                                                 new_image,
1176                                                 &manifest));
1177
1178  // Serialize protobuf
1179  string serialized_manifest;
1180
1181  CheckGraph(graph);
1182  TEST_AND_RETURN_FALSE(manifest.AppendToString(&serialized_manifest));
1183  CheckGraph(graph);
1184
1185  LOG(INFO) << "Writing final delta file header...";
1186  DirectFileWriter writer;
1187  TEST_AND_RETURN_FALSE_ERRNO(writer.Open(output_path.c_str(),
1188                                          O_WRONLY | O_CREAT | O_TRUNC,
1189                                          0644) == 0);
1190  ScopedFileWriterCloser writer_closer(&writer);
1191
1192  // Write header
1193  TEST_AND_RETURN_FALSE(writer.Write(kDeltaMagic, strlen(kDeltaMagic)));
1194
1195  // Write version number
1196  TEST_AND_RETURN_FALSE(WriteUint64AsBigEndian(&writer, kVersionNumber));
1197
1198  // Write protobuf length
1199  TEST_AND_RETURN_FALSE(WriteUint64AsBigEndian(&writer,
1200                                               serialized_manifest.size()));
1201
1202  // Write protobuf
1203  LOG(INFO) << "Writing final delta file protobuf... "
1204            << serialized_manifest.size();
1205  TEST_AND_RETURN_FALSE(writer.Write(serialized_manifest.data(),
1206                                     serialized_manifest.size()));
1207
1208  // Append the data blobs
1209  LOG(INFO) << "Writing final delta file data blobs...";
1210  int blobs_fd = open(ordered_blobs_path.c_str(), O_RDONLY, 0);
1211  ScopedFdCloser blobs_fd_closer(&blobs_fd);
1212  TEST_AND_RETURN_FALSE(blobs_fd >= 0);
1213  for (;;) {
1214    char buf[kBlockSize];
1215    ssize_t rc = read(blobs_fd, buf, sizeof(buf));
1216    if (0 == rc) {
1217      // EOF
1218      break;
1219    }
1220    TEST_AND_RETURN_FALSE_ERRNO(rc > 0);
1221    TEST_AND_RETURN_FALSE(writer.Write(buf, rc));
1222  }
1223
1224  // Write signature blob.
1225  if (!private_key_path.empty()) {
1226    LOG(INFO) << "Signing the update...";
1227    chromeos::Blob signature_blob;
1228    TEST_AND_RETURN_FALSE(PayloadSigner::SignPayload(
1229        output_path,
1230        vector<string>(1, private_key_path),
1231        &signature_blob));
1232    TEST_AND_RETURN_FALSE(writer.Write(signature_blob.data(),
1233                                       signature_blob.size()));
1234  }
1235
1236  *metadata_size =
1237      strlen(kDeltaMagic) + 2 * sizeof(uint64_t) + serialized_manifest.size();
1238  ReportPayloadUsage(manifest, *metadata_size, op_name_map);
1239
1240  LOG(INFO) << "All done. Successfully created delta file with "
1241            << "metadata size = " << *metadata_size;
1242  return true;
1243}
1244
1245// Runs the bsdiff tool on two files and returns the resulting delta in
1246// 'out'. Returns true on success.
1247bool DeltaDiffGenerator::BsdiffFiles(const string& old_file,
1248                                     const string& new_file,
1249                                     chromeos::Blob* out) {
1250  const string kPatchFile = "delta.patchXXXXXX";
1251  string patch_file_path;
1252
1253  TEST_AND_RETURN_FALSE(
1254      utils::MakeTempFile(kPatchFile, &patch_file_path, nullptr));
1255
1256  vector<string> cmd;
1257  cmd.push_back(kBsdiffPath);
1258  cmd.push_back(old_file);
1259  cmd.push_back(new_file);
1260  cmd.push_back(patch_file_path);
1261
1262  int rc = 1;
1263  chromeos::Blob patch_file;
1264  TEST_AND_RETURN_FALSE(Subprocess::SynchronousExec(cmd, &rc, nullptr));
1265  TEST_AND_RETURN_FALSE(rc == 0);
1266  TEST_AND_RETURN_FALSE(utils::ReadFile(patch_file_path, out));
1267  unlink(patch_file_path.c_str());
1268  return true;
1269}
1270
1271void DeltaDiffGenerator::AddSignatureOp(uint64_t signature_blob_offset,
1272                                        uint64_t signature_blob_length,
1273                                        DeltaArchiveManifest* manifest) {
1274  LOG(INFO) << "Making room for signature in file";
1275  manifest->set_signatures_offset(signature_blob_offset);
1276  LOG(INFO) << "set? " << manifest->has_signatures_offset();
1277  // Add a dummy op at the end to appease older clients
1278  DeltaArchiveManifest_InstallOperation* dummy_op =
1279      manifest->add_kernel_install_operations();
1280  dummy_op->set_type(DeltaArchiveManifest_InstallOperation_Type_REPLACE);
1281  dummy_op->set_data_offset(signature_blob_offset);
1282  manifest->set_signatures_offset(signature_blob_offset);
1283  dummy_op->set_data_length(signature_blob_length);
1284  manifest->set_signatures_size(signature_blob_length);
1285  Extent* dummy_extent = dummy_op->add_dst_extents();
1286  // Tell the dummy op to write this data to a big sparse hole
1287  dummy_extent->set_start_block(kSparseHole);
1288  dummy_extent->set_num_blocks((signature_blob_length + kBlockSize - 1) /
1289                               kBlockSize);
1290}
1291
1292};  // namespace chromeos_update_engine
1293