1 #!/usr/bin/env python 2 # 3 # Copyright (C) 2011 The Android Open Source Project 4 # 5 # Licensed under the Apache License, Version 2.0 (the "License"); 6 # you may not use this file except in compliance with the License. 7 # You may obtain a copy of the License at 8 # 9 # http://www.apache.org/licenses/LICENSE-2.0 10 # 11 # Unless required by applicable law or agreed to in writing, software 12 # distributed under the License is distributed on an "AS IS" BASIS, 13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 # See the License for the specific language governing permissions and 15 # limitations under the License. 16 17 """ 18 Build image output_image_file from input_directory and properties_file. 19 20 Usage: build_image input_directory properties_file output_image_file 21 22 """ 23 import os 24 import os.path 25 import subprocess 26 import sys 27 import commands 28 import shutil 29 import tempfile 30 31 FIXED_SALT = "aee087a5be3b982978c923f566a94613496b417f2af592639bc80d141e34dfe7" 32 33 def RunCommand(cmd): 34 """ Echo and run the given command 35 36 Args: 37 cmd: the command represented as a list of strings. 38 Returns: 39 The exit code. 40 """ 41 print "Running: ", " ".join(cmd) 42 p = subprocess.Popen(cmd) 43 p.communicate() 44 return p.returncode 45 46 def GetVerityTreeSize(partition_size): 47 cmd = "build_verity_tree -s %d" 48 cmd %= partition_size 49 status, output = commands.getstatusoutput(cmd) 50 if status: 51 print output 52 return False, 0 53 return True, int(output) 54 55 def GetVerityMetadataSize(partition_size): 56 cmd = "system/extras/verity/build_verity_metadata.py -s %d" 57 cmd %= partition_size 58 status, output = commands.getstatusoutput(cmd) 59 if status: 60 print output 61 return False, 0 62 return True, int(output) 63 64 def AdjustPartitionSizeForVerity(partition_size): 65 """Modifies the provided partition size to account for the verity metadata. 66 67 This information is used to size the created image appropriately. 68 Args: 69 partition_size: the size of the partition to be verified. 70 Returns: 71 The size of the partition adjusted for verity metadata. 72 """ 73 success, verity_tree_size = GetVerityTreeSize(partition_size) 74 if not success: 75 return 0; 76 success, verity_metadata_size = GetVerityMetadataSize(partition_size) 77 if not success: 78 return 0 79 return partition_size - verity_tree_size - verity_metadata_size 80 81 def BuildVerityTree(sparse_image_path, verity_image_path, prop_dict): 82 cmd = ("build_verity_tree -A %s %s %s" % (FIXED_SALT, sparse_image_path, verity_image_path)) 83 print cmd 84 status, output = commands.getstatusoutput(cmd) 85 if status: 86 print "Could not build verity tree! Error: %s" % output 87 return False 88 root, salt = output.split() 89 prop_dict["verity_root_hash"] = root 90 prop_dict["verity_salt"] = salt 91 return True 92 93 def BuildVerityMetadata(image_size, verity_metadata_path, root_hash, salt, 94 block_device, signer_path, key): 95 cmd = ("system/extras/verity/build_verity_metadata.py %s %s %s %s %s %s %s" % 96 (image_size, 97 verity_metadata_path, 98 root_hash, 99 salt, 100 block_device, 101 signer_path, 102 key)) 103 print cmd 104 status, output = commands.getstatusoutput(cmd) 105 if status: 106 print "Could not build verity metadata! Error: %s" % output 107 return False 108 return True 109 110 def Append2Simg(sparse_image_path, unsparse_image_path, error_message): 111 """Appends the unsparse image to the given sparse image. 112 113 Args: 114 sparse_image_path: the path to the (sparse) image 115 unsparse_image_path: the path to the (unsparse) image 116 Returns: 117 True on success, False on failure. 118 """ 119 cmd = "append2simg %s %s" 120 cmd %= (sparse_image_path, unsparse_image_path) 121 print cmd 122 status, output = commands.getstatusoutput(cmd) 123 if status: 124 print "%s: %s" % (error_message, output) 125 return False 126 return True 127 128 def BuildVerifiedImage(data_image_path, verity_image_path, verity_metadata_path): 129 if not Append2Simg(data_image_path, verity_metadata_path, "Could not append verity metadata!"): 130 return False 131 if not Append2Simg(data_image_path, verity_image_path, "Could not append verity tree!"): 132 return False 133 return True 134 135 def UnsparseImage(sparse_image_path, replace=True): 136 img_dir = os.path.dirname(sparse_image_path) 137 unsparse_image_path = "unsparse_" + os.path.basename(sparse_image_path) 138 unsparse_image_path = os.path.join(img_dir, unsparse_image_path) 139 if os.path.exists(unsparse_image_path): 140 if replace: 141 os.unlink(unsparse_image_path) 142 else: 143 return True, unsparse_image_path 144 inflate_command = ["simg2img", sparse_image_path, unsparse_image_path] 145 exit_code = RunCommand(inflate_command) 146 if exit_code != 0: 147 os.remove(unsparse_image_path) 148 return False, None 149 return True, unsparse_image_path 150 151 def MakeVerityEnabledImage(out_file, prop_dict): 152 """Creates an image that is verifiable using dm-verity. 153 154 Args: 155 out_file: the location to write the verifiable image at 156 prop_dict: a dictionary of properties required for image creation and verification 157 Returns: 158 True on success, False otherwise. 159 """ 160 # get properties 161 image_size = prop_dict["partition_size"] 162 block_dev = prop_dict["verity_block_device"] 163 signer_key = prop_dict["verity_key"] 164 signer_path = prop_dict["verity_signer_cmd"] 165 166 # make a tempdir 167 tempdir_name = tempfile.mkdtemp(suffix="_verity_images") 168 169 # get partial image paths 170 verity_image_path = os.path.join(tempdir_name, "verity.img") 171 verity_metadata_path = os.path.join(tempdir_name, "verity_metadata.img") 172 173 # build the verity tree and get the root hash and salt 174 if not BuildVerityTree(out_file, verity_image_path, prop_dict): 175 shutil.rmtree(tempdir_name, ignore_errors=True) 176 return False 177 178 # build the metadata blocks 179 root_hash = prop_dict["verity_root_hash"] 180 salt = prop_dict["verity_salt"] 181 if not BuildVerityMetadata(image_size, 182 verity_metadata_path, 183 root_hash, 184 salt, 185 block_dev, 186 signer_path, 187 signer_key): 188 shutil.rmtree(tempdir_name, ignore_errors=True) 189 return False 190 191 # build the full verified image 192 if not BuildVerifiedImage(out_file, 193 verity_image_path, 194 verity_metadata_path): 195 shutil.rmtree(tempdir_name, ignore_errors=True) 196 return False 197 198 shutil.rmtree(tempdir_name, ignore_errors=True) 199 return True 200 201 def BuildImage(in_dir, prop_dict, out_file, 202 fs_config=None, 203 fc_config=None, 204 block_list=None): 205 """Build an image to out_file from in_dir with property prop_dict. 206 207 Args: 208 in_dir: path of input directory. 209 prop_dict: property dictionary. 210 out_file: path of the output image file. 211 fs_config: path to the fs_config file (typically 212 META/filesystem_config.txt). If None then the configuration in 213 the local client will be used. 214 fc_config: path to the SELinux file_contexts file. If None then 215 the value from prop_dict['selinux_fc'] will be used. 216 217 Returns: 218 True iff the image is built successfully. 219 """ 220 build_command = [] 221 fs_type = prop_dict.get("fs_type", "") 222 run_fsck = False 223 224 is_verity_partition = "verity_block_device" in prop_dict 225 verity_supported = prop_dict.get("verity") == "true" 226 # adjust the partition size to make room for the hashes if this is to be verified 227 if verity_supported and is_verity_partition: 228 partition_size = int(prop_dict.get("partition_size")) 229 adjusted_size = AdjustPartitionSizeForVerity(partition_size) 230 if not adjusted_size: 231 return False 232 prop_dict["partition_size"] = str(adjusted_size) 233 prop_dict["original_partition_size"] = str(partition_size) 234 235 if fs_type.startswith("ext"): 236 build_command = ["mkuserimg.sh"] 237 if "extfs_sparse_flag" in prop_dict: 238 build_command.append(prop_dict["extfs_sparse_flag"]) 239 run_fsck = True 240 build_command.extend([in_dir, out_file, fs_type, 241 prop_dict["mount_point"]]) 242 build_command.append(prop_dict["partition_size"]) 243 if "timestamp" in prop_dict: 244 build_command.extend(["-T", str(prop_dict["timestamp"])]) 245 if fs_config is not None: 246 build_command.extend(["-C", fs_config]) 247 if block_list is not None: 248 build_command.extend(["-B", block_list]) 249 if fc_config is not None: 250 build_command.append(fc_config) 251 elif "selinux_fc" in prop_dict: 252 build_command.append(prop_dict["selinux_fc"]) 253 elif fs_type.startswith("f2fs"): 254 build_command = ["mkf2fsuserimg.sh"] 255 build_command.extend([out_file, prop_dict["partition_size"]]) 256 else: 257 build_command = ["mkyaffs2image", "-f"] 258 if prop_dict.get("mkyaffs2_extra_flags", None): 259 build_command.extend(prop_dict["mkyaffs2_extra_flags"].split()) 260 build_command.append(in_dir) 261 build_command.append(out_file) 262 if "selinux_fc" in prop_dict: 263 build_command.append(prop_dict["selinux_fc"]) 264 build_command.append(prop_dict["mount_point"]) 265 266 exit_code = RunCommand(build_command) 267 if exit_code != 0: 268 return False 269 270 # create the verified image if this is to be verified 271 if verity_supported and is_verity_partition: 272 if not MakeVerityEnabledImage(out_file, prop_dict): 273 return False 274 275 if run_fsck and prop_dict.get("skip_fsck") != "true": 276 success, unsparse_image = UnsparseImage(out_file, replace=False) 277 if not success: 278 return False 279 280 # Run e2fsck on the inflated image file 281 e2fsck_command = ["e2fsck", "-f", "-n", unsparse_image] 282 exit_code = RunCommand(e2fsck_command) 283 284 os.remove(unsparse_image) 285 286 return exit_code == 0 287 288 289 def ImagePropFromGlobalDict(glob_dict, mount_point): 290 """Build an image property dictionary from the global dictionary. 291 292 Args: 293 glob_dict: the global dictionary from the build system. 294 mount_point: such as "system", "data" etc. 295 """ 296 d = {} 297 if "build.prop" in glob_dict: 298 bp = glob_dict["build.prop"] 299 if "ro.build.date.utc" in bp: 300 d["timestamp"] = bp["ro.build.date.utc"] 301 302 def copy_prop(src_p, dest_p): 303 if src_p in glob_dict: 304 d[dest_p] = str(glob_dict[src_p]) 305 306 common_props = ( 307 "extfs_sparse_flag", 308 "mkyaffs2_extra_flags", 309 "selinux_fc", 310 "skip_fsck", 311 "verity", 312 "verity_key", 313 "verity_signer_cmd" 314 ) 315 for p in common_props: 316 copy_prop(p, p) 317 318 d["mount_point"] = mount_point 319 if mount_point == "system": 320 copy_prop("fs_type", "fs_type") 321 copy_prop("system_size", "partition_size") 322 copy_prop("system_verity_block_device", "verity_block_device") 323 elif mount_point == "data": 324 # Copy the generic fs type first, override with specific one if available. 325 copy_prop("fs_type", "fs_type") 326 copy_prop("userdata_fs_type", "fs_type") 327 copy_prop("userdata_size", "partition_size") 328 elif mount_point == "cache": 329 copy_prop("cache_fs_type", "fs_type") 330 copy_prop("cache_size", "partition_size") 331 elif mount_point == "vendor": 332 copy_prop("vendor_fs_type", "fs_type") 333 copy_prop("vendor_size", "partition_size") 334 copy_prop("vendor_verity_block_device", "verity_block_device") 335 elif mount_point == "oem": 336 copy_prop("fs_type", "fs_type") 337 copy_prop("oem_size", "partition_size") 338 339 return d 340 341 342 def LoadGlobalDict(filename): 343 """Load "name=value" pairs from filename""" 344 d = {} 345 f = open(filename) 346 for line in f: 347 line = line.strip() 348 if not line or line.startswith("#"): 349 continue 350 k, v = line.split("=", 1) 351 d[k] = v 352 f.close() 353 return d 354 355 356 def main(argv): 357 if len(argv) != 3: 358 print __doc__ 359 sys.exit(1) 360 361 in_dir = argv[0] 362 glob_dict_file = argv[1] 363 out_file = argv[2] 364 365 glob_dict = LoadGlobalDict(glob_dict_file) 366 image_filename = os.path.basename(out_file) 367 mount_point = "" 368 if image_filename == "system.img": 369 mount_point = "system" 370 elif image_filename == "userdata.img": 371 mount_point = "data" 372 elif image_filename == "cache.img": 373 mount_point = "cache" 374 elif image_filename == "vendor.img": 375 mount_point = "vendor" 376 elif image_filename == "oem.img": 377 mount_point = "oem" 378 else: 379 print >> sys.stderr, "error: unknown image file name ", image_filename 380 exit(1) 381 382 image_properties = ImagePropFromGlobalDict(glob_dict, mount_point) 383 if not BuildImage(in_dir, image_properties, out_file): 384 print >> sys.stderr, "error: failed to build %s from %s" % (out_file, in_dir) 385 exit(1) 386 387 388 if __name__ == '__main__': 389 main(sys.argv[1:]) 390
