releasetools: Pack the offset/length for metadata.
For streaming OTAs, we will also need the info in the metadata entry
(META-INF/com/android/metadata). Compute and pack its offset/length
values into 'ota-streaming-property-files'.
Bug: 34986195
Test: Create an OTA package and check the offset/length values.
Change-Id: Id150700f2bc9bff02467cda9fe8927c8a374412a
diff --git a/tools/releasetools/ota_from_target_files.py b/tools/releasetools/ota_from_target_files.py
index bd033eb..c04c785 100755
--- a/tools/releasetools/ota_from_target_files.py
+++ b/tools/releasetools/ota_from_target_files.py
@@ -126,8 +126,9 @@
print("Python 2.7 or newer is required.", file=sys.stderr)
sys.exit(1)
+import copy
import multiprocessing
-import os
+import os.path
import subprocess
import shlex
import tempfile
@@ -167,6 +168,8 @@
OPTIONS.payload_signer = None
OPTIONS.payload_signer_args = []
+METADATA_NAME = 'META-INF/com/android/metadata'
+
def MostPopularKey(d, default):
"""Given a dict, return the key corresponding to the largest
value. Returns 'default' if the dict is empty."""
@@ -415,7 +418,6 @@
symlinks.append((input_zip.read(info.filename),
"/" + partition + "/" + basefilename))
else:
- import copy
info2 = copy.copy(info)
fn = info2.filename = partition + "/" + basefilename
if substitute and fn in substitute and substitute[fn] is None:
@@ -774,9 +776,9 @@
def WriteMetadata(metadata, output_zip):
- common.ZipWriteStr(output_zip, "META-INF/com/android/metadata",
- "".join(["%s=%s\n" % kv
- for kv in sorted(metadata.iteritems())]))
+ value = "".join(["%s=%s\n" % kv for kv in sorted(metadata.iteritems())])
+ common.ZipWriteStr(output_zip, METADATA_NAME, value,
+ compress_type=zipfile.ZIP_STORED)
def LoadPartitionFiles(z, partition):
@@ -1226,15 +1228,25 @@
source_file=None):
"""Generate an Android OTA package that has A/B update payload."""
- def ComputeStreamingMetadata(zip_file):
- """Compute the streaming metadata for a given zip."""
+ def ComputeStreamingMetadata(zip_file, reserve_space=False,
+ expected_length=None):
+ """Compute the streaming metadata for a given zip.
+
+ When 'reserve_space' is True, we reserve extra space for the offset and
+ length of the metadata entry itself, although we don't know the final
+ values until the package gets signed. This function will be called again
+ after signing. We then write the actual values and pad the string to the
+ length we set earlier. Note that we can't use the actual length of the
+ metadata entry in the second run. Otherwise the offsets for other entries
+ will be changing again.
+ """
def ComputeEntryOffsetSize(name):
"""Compute the zip entry offset and size."""
info = zip_file.getinfo(name)
offset = info.header_offset + len(info.FileHeader())
size = info.file_size
- return '%s:%d:%d' % (name, offset, size)
+ return '%s:%d:%d' % (os.path.basename(name), offset, size)
# payload.bin and payload_properties.txt must exist.
offsets = [ComputeEntryOffsetSize('payload.bin'),
@@ -1243,7 +1255,25 @@
# care_map.txt is available only if dm-verity is enabled.
if 'care_map.txt' in zip_file.namelist():
offsets.append(ComputeEntryOffsetSize('care_map.txt'))
- return ','.join(offsets)
+
+ # 'META-INF/com/android/metadata' is required. We don't know its actual
+ # offset and length (as well as the values for other entries). So we
+ # reserve 10-byte as a placeholder, which is to cover the space for metadata
+ # entry ('xx:xxx', since it's ZIP_STORED which should appear at the
+ # beginning of the zip), as well as the possible value changes in other
+ # entries.
+ if reserve_space:
+ offsets.append('metadata:' + ' ' * 10)
+ else:
+ offsets.append(ComputeEntryOffsetSize(METADATA_NAME))
+
+ value = ','.join(offsets)
+ if expected_length is not None:
+ assert len(value) <= expected_length, \
+ 'Insufficient reserved space: reserved=%d, actual=%d' % (
+ expected_length, len(value))
+ value += ' ' * (expected_length - len(value))
+ return value
# The place where the output from the subprocess should go.
log_file = sys.stdout if OPTIONS.verbose else subprocess.PIPE
@@ -1406,36 +1436,55 @@
print("Warning: cannot find care map file in target_file package")
common.ZipClose(target_zip)
- # SignOutput(), which in turn calls signapk.jar, will possibly reorder the
- # zip entries, as well as padding the entry headers. We sign the current
- # package (without the metadata entry) to allow that to happen. Then compute
- # the zip entry offsets, write the metadata and do the signing again.
- common.ZipClose(output_zip)
- temp_signing = tempfile.NamedTemporaryFile()
- SignOutput(temp_zip_file.name, temp_signing.name)
- temp_zip_file.close()
-
- # Open the signed zip. Compute the metadata that's needed for streaming.
- output_zip = zipfile.ZipFile(temp_signing, "a",
- compression=zipfile.ZIP_DEFLATED)
+ # Write the current metadata entry with placeholders.
metadata['ota-streaming-property-files'] = ComputeStreamingMetadata(
- output_zip)
-
- # Write the metadata entry into the zip.
+ output_zip, reserve_space=True)
WriteMetadata(metadata, output_zip)
common.ZipClose(output_zip)
- # Re-sign the package after adding the metadata entry, which should not
- # affect the entries that are needed for streaming. Because signapk packs
- # ZIP_STORED entries first, then the ZIP_DEFLATED entries such as metadata.
- SignOutput(temp_signing.name, output_file)
- temp_signing.close()
+ # SignOutput(), which in turn calls signapk.jar, will possibly reorder the
+ # zip entries, as well as padding the entry headers. We do a preliminary
+ # signing (with an incomplete metadata entry) to allow that to happen. Then
+ # compute the zip entry offsets, write back the final metadata and do the
+ # final signing.
+ prelim_signing = tempfile.NamedTemporaryFile()
+ SignOutput(temp_zip_file.name, prelim_signing.name)
+ common.ZipClose(temp_zip_file)
- # Reopen the signed zip to double check the streaming metadata.
+ # Open the signed zip. Compute the final metadata that's needed for streaming.
+ prelim_zip = zipfile.ZipFile(prelim_signing, "r",
+ compression=zipfile.ZIP_DEFLATED)
+ expected_length = len(metadata['ota-streaming-property-files'])
+ metadata['ota-streaming-property-files'] = ComputeStreamingMetadata(
+ prelim_zip, reserve_space=False, expected_length=expected_length)
+
+ # Copy the zip entries, as we cannot update / delete entries with zipfile.
+ final_signing = tempfile.NamedTemporaryFile()
+ output_zip = zipfile.ZipFile(final_signing, "w",
+ compression=zipfile.ZIP_DEFLATED)
+ for item in prelim_zip.infolist():
+ if item.filename == METADATA_NAME:
+ continue
+
+ data = prelim_zip.read(item.filename)
+ out_info = copy.copy(item)
+ common.ZipWriteStr(output_zip, out_info, data)
+
+ # Now write the final metadata entry.
+ WriteMetadata(metadata, output_zip)
+ common.ZipClose(prelim_zip)
+ common.ZipClose(output_zip)
+
+ # Re-sign the package after updating the metadata entry.
+ SignOutput(final_signing.name, output_file)
+ final_signing.close()
+
+ # Reopen the final signed zip to double check the streaming metadata.
output_zip = zipfile.ZipFile(output_file, "r")
- assert (metadata['ota-streaming-property-files'] ==
- ComputeStreamingMetadata(output_zip)), \
- "Mismatching streaming metadata."
+ actual = metadata['ota-streaming-property-files'].strip()
+ expected = ComputeStreamingMetadata(output_zip)
+ assert actual == expected, \
+ "Mismatching streaming metadata: %s vs %s." % (actual, expected)
common.ZipClose(output_zip)