update_engine: Add support for parsing the size of a squashfs.
This patch extends the utils::GetFilesystemSize() function to support
squashfs (in addition to the existing ext3 support). The filesystem
type is detected automatically.
squashfs doesn't define a block size for the physical device that it
relies on. There's a definition of block size for the data before
compression that doesn't affect the block size used for the underlying
device. When creating the squashfs, it is by default padded to 4 KiB,
so we assume 4 KiB as the block size. This is also the minimum block
size required by verity to compute hashes in all supported archs.
BUG=chromium:430956
TEST=Unittest added.
Change-Id: Ia683a27c094e25952e8d665535dc6219c849bdd0
Reviewed-on: https://chromium-review.googlesource.com/228906
Reviewed-by: Gaurav Shah <gauravsh@chromium.org>
Commit-Queue: Alex Deymo <deymo@chromium.org>
Tested-by: Alex Deymo <deymo@chromium.org>
diff --git a/utils_unittest.cc b/utils_unittest.cc
index 0e29113..e3133f9 100644
--- a/utils_unittest.cc
+++ b/utils_unittest.cc
@@ -331,6 +331,73 @@
EXPECT_EQ(10 * 1024 * 1024 / 4096, block_count);
}
+// Squashfs example filesystem, generated with:
+// echo hola>hola
+// mksquashfs hola hola.sqfs -noappend -nopad
+// hexdump hola.sqfs -e '16/1 "%02x, " "\n"'
+const unsigned char kSquashfsFile[] = {
+ 0x68, 0x73, 0x71, 0x73, 0x02, 0x00, 0x00, 0x00, // magic, inodes
+ 0x3e, 0x49, 0x61, 0x54, 0x00, 0x00, 0x02, 0x00,
+ 0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x11, 0x00,
+ 0xc0, 0x00, 0x02, 0x00, 0x04, 0x00, 0x00, 0x00, // flags, noids, major, minor
+ 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // root_inode
+ 0xef, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // bytes_used
+ 0xe7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0x65, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x93, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0xbd, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0xd5, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x68, 0x6f, 0x6c, 0x61, 0x0a, 0x2c, 0x00, 0x78,
+ 0xda, 0x63, 0x62, 0x58, 0xc2, 0xc8, 0xc0, 0xc0,
+ 0xc8, 0xd0, 0x6b, 0x91, 0x18, 0x02, 0x64, 0xa0,
+ 0x00, 0x56, 0x06, 0x90, 0xcc, 0x7f, 0xb0, 0xbc,
+ 0x9d, 0x67, 0x62, 0x08, 0x13, 0x54, 0x1c, 0x44,
+ 0x4b, 0x03, 0x31, 0x33, 0x10, 0x03, 0x00, 0xb5,
+ 0x87, 0x04, 0x89, 0x16, 0x00, 0x78, 0xda, 0x63,
+ 0x60, 0x80, 0x00, 0x46, 0x28, 0xcd, 0xc4, 0xc0,
+ 0xcc, 0x90, 0x91, 0x9f, 0x93, 0x08, 0x00, 0x04,
+ 0x70, 0x01, 0xab, 0x10, 0x80, 0x60, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00,
+ 0x01, 0x00, 0x00, 0x00, 0x00, 0xab, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x0e, 0x00, 0x78,
+ 0xda, 0x63, 0x60, 0x80, 0x00, 0x05, 0x28, 0x0d,
+ 0x00, 0x01, 0x10, 0x00, 0x21, 0xc5, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x80, 0x99,
+ 0xcd, 0x02, 0x00, 0x88, 0x13, 0x00, 0x00, 0xdd,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+TEST(UtilsTest, GetSquashfs4Size) {
+ unsigned char buffer[sizeof(kSquashfsFile)];
+ memcpy(buffer, kSquashfsFile, sizeof(kSquashfsFile));
+
+ int block_count = -1;
+ int block_size = -1;
+ // Not enough bytes passed.
+ EXPECT_FALSE(utils::GetSquashfs4Size(buffer, 10, nullptr, nullptr));
+
+ // The whole file system is passed, which is enough for parsing.
+ EXPECT_TRUE(utils::GetSquashfs4Size(buffer, sizeof(kSquashfsFile),
+ &block_count, &block_size));
+ EXPECT_EQ(4096, block_size);
+ EXPECT_EQ(1, block_count);
+
+ // Modify the major version to 5.
+ uint16_t* s_major = reinterpret_cast<uint16_t*>(buffer + 0x1c);
+ *s_major = 5;
+ EXPECT_FALSE(utils::GetSquashfs4Size(buffer, 10, nullptr, nullptr));
+ memcpy(buffer, kSquashfsFile, sizeof(kSquashfsFile));
+
+ // Modify the bytes_used to have 6 blocks.
+ int64_t* bytes_used = reinterpret_cast<int64_t*>(buffer + 0x28);
+ *bytes_used = 4096 * 5 + 1; // 6 "blocks".
+ EXPECT_TRUE(utils::GetSquashfs4Size(buffer, sizeof(kSquashfsFile),
+ &block_count, &block_size));
+ EXPECT_EQ(4096, block_size);
+ EXPECT_EQ(6, block_count);
+}
+
TEST(UtilsTest, GetInstallDevTest) {
string boot_dev = "/dev/sda5";
string install_dev;