extractNativeLibs 配置怎样影响 APK 内 SO 的压缩、对齐与安装

import argparse
import struct
import sys
import zipfile
from pathlib import Path

parser = argparse.ArgumentParser()
parser.add_argument("apk")
parser.add_argument("--policy", choices=("extract", "no-extract"), required=True)
parser.add_argument("--alignment", type=int, required=True)
parser.add_argument("--abi", action="append", required=True)
args = parser.parse_args()

apk_path = Path(args.apk).resolve()
if not apk_path.is_file():
    raise SystemExit("APK file is missing")
if args.alignment < 4096 or args.alignment & (args.alignment - 1):
    raise SystemExit("alignment must be a power of two and at least 4096")
allowed_abis = set(args.abi)
if any("/" in abi or not abi for abi in allowed_abis):
    raise SystemExit("invalid ABI policy value")

machine_by_abi = {
    "armeabi-v7a": 40,
    "arm64-v8a": 183,
    "x86": 3,
    "x86_64": 62,
    "riscv64": 243,
}

def data_offset(stream, info):
    stream.seek(info.header_offset)
    header = stream.read(30)
    if len(header) != 30:
        raise ValueError("truncated local file header")
    signature, = struct.unpack_from("<I", header, 0)
    if signature != 0x04034B50:
        raise ValueError("invalid local file header signature")
    name_len, extra_len = struct.unpack_from("<HH", header, 26)
    return info.header_offset + 30 + name_len + extra_len

def load_alignments(blob, abi):
    if blob[:4] != b"\x7fELF":
        raise ValueError("native library lacks ELF magic")
    elf_class, endian = blob[4], blob[5]
    if endian != 1:
        raise ValueError("only little-endian Android ELF is accepted")
    if elf_class == 2:
        machine = struct.unpack_from("<H", blob, 18)[0]
        phoff = struct.unpack_from("<Q", blob, 32)[0]
        phentsize = struct.unpack_from("<H", blob, 54)[0]
        phnum = struct.unpack_from("<H", blob, 56)[0]
        align_offset = 48
    elif elf_class == 1:
        machine = struct.unpack_from("<H", blob, 18)[0]
        phoff = struct.unpack_from("<I", blob, 28)[0]
        phentsize = struct.unpack_from("<H", blob, 42)[0]
        phnum = struct.unpack_from("<H", blob, 44)[0]
        align_offset = 28
    else:
        raise ValueError("unsupported ELF class")
    if machine_by_abi.get(abi) != machine:
        raise ValueError("ELF machine differs from ABI path")
    values = []
    for index in range(phnum):
        offset = phoff + index * phentsize
        if offset + phentsize > len(blob):
            raise ValueError("program header exceeds file")
        segment_type = struct.unpack_from("<I", blob, offset)[0]
        if segment_type == 1:
            fmt = "<Q" if elf_class == 2 else "<I"
            values.append(struct.unpack_from(fmt, blob, offset + align_offset)[0])
    if not values:
        raise ValueError("ELF has no PT_LOAD segments")
    return values

errors = []
with apk_path.open("rb") as raw, zipfile.ZipFile(raw) as archive:
    libraries = [item for item in archive.infolist()
                 if item.filename.startswith("lib/") and item.filename.endswith(".so")]
    if not libraries:
        raise SystemExit("APK contains no native libraries")
    for info in libraries:
        parts = info.filename.split("/")
        if len(parts) != 3 or parts[1] not in allowed_abis:
            errors.append(f"{info.filename}: ABI path is not allowed")
            continue
        abi = parts[1]
        try:
            offset = data_offset(raw, info)
            if args.policy == "no-extract" and info.compress_type != zipfile.ZIP_STORED:
                errors.append(f"{info.filename}: compressed under no-extract policy")
            if args.policy == "no-extract" and offset % args.alignment:
                errors.append(f"{info.filename}: ZIP data offset is not aligned")
            blob = archive.read(info)
            if not blob:
                errors.append(f"{info.filename}: empty library")
                continue
            for value in load_alignments(blob, abi):
                if value < args.alignment or value & (value - 1):
                    errors.append(f"{info.filename}: PT_LOAD p_align is insufficient")
        except (OSError, ValueError, struct.error, zipfile.BadZipFile) as exc:
            errors.append(f"{info.filename}: {type(exc).__name__}")

if errors:
    for error in sorted(set(errors)):
        print(error)
    raise SystemExit("APK native library policy gate failed")
print(f"passed: {apk_path.name}, policy={args.policy}, alignment={args.alignment}")