| #define LOG_TAG "file_backup_helper" |
| |
| #include <utils/backup_helpers.h> |
| |
| #include <utils/KeyedVector.h> |
| #include <utils/ByteOrder.h> |
| #include <utils/String8.h> |
| |
| #include <errno.h> |
| #include <sys/types.h> |
| #include <sys/uio.h> |
| #include <sys/stat.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <utime.h> |
| #include <fcntl.h> |
| #include <zlib.h> |
| |
| #include <cutils/log.h> |
| |
| using namespace android; |
| |
| #define MAGIC0 0x70616e53 // Snap |
| #define MAGIC1 0x656c6946 // File |
| |
| struct SnapshotHeader { |
| int magic0; |
| int fileCount; |
| int magic1; |
| int totalSize; |
| }; |
| |
| struct FileState { |
| int modTime_sec; |
| int modTime_nsec; |
| int size; |
| int crc32; |
| int nameLen; |
| }; |
| |
| const static int ROUND_UP[4] = { 0, 3, 2, 1 }; |
| |
| static inline int |
| round_up(int n) |
| { |
| return n + ROUND_UP[n % 4]; |
| } |
| |
| static int |
| read_snapshot_file(int fd, KeyedVector<String8,FileState>* snapshot) |
| { |
| int bytesRead = 0; |
| int amt; |
| SnapshotHeader header; |
| |
| amt = read(fd, &header, sizeof(header)); |
| if (amt != sizeof(header)) { |
| return errno; |
| } |
| bytesRead += amt; |
| |
| if (header.magic0 != MAGIC0 || header.magic1 != MAGIC1) { |
| LOGW("read_snapshot_file header.magic0=0x%08x magic1=0x%08x", header.magic0, header.magic1); |
| return 1; |
| } |
| |
| for (int i=0; i<header.fileCount; i++) { |
| FileState file; |
| char filenameBuf[128]; |
| |
| amt = read(fd, &file, sizeof(file)); |
| if (amt != sizeof(file)) { |
| LOGW("read_snapshot_file FileState truncated/error with read at %d bytes\n", bytesRead); |
| return 1; |
| } |
| bytesRead += amt; |
| |
| // filename is not NULL terminated, but it is padded |
| int nameBufSize = round_up(file.nameLen); |
| char* filename = nameBufSize <= (int)sizeof(filenameBuf) |
| ? filenameBuf |
| : (char*)malloc(nameBufSize); |
| amt = read(fd, filename, nameBufSize); |
| if (amt == nameBufSize) { |
| snapshot->add(String8(filename, file.nameLen), file); |
| } |
| bytesRead += amt; |
| if (filename != filenameBuf) { |
| free(filename); |
| } |
| if (amt != nameBufSize) { |
| LOGW("read_snapshot_file filename truncated/error with read at %d bytes\n", bytesRead); |
| return 1; |
| } |
| } |
| |
| if (header.totalSize != bytesRead) { |
| LOGW("read_snapshot_file length mismatch: header.totalSize=%d bytesRead=%d\n", |
| header.totalSize, bytesRead); |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| static int |
| write_snapshot_file(int fd, const KeyedVector<String8,FileState>& snapshot) |
| { |
| int bytesWritten = sizeof(SnapshotHeader); |
| // preflight size |
| const int N = snapshot.size(); |
| for (int i=0; i<N; i++) { |
| const String8& name = snapshot.keyAt(i); |
| bytesWritten += sizeof(FileState) + round_up(name.length()); |
| } |
| |
| int amt; |
| SnapshotHeader header = { MAGIC0, N, MAGIC1, bytesWritten }; |
| |
| amt = write(fd, &header, sizeof(header)); |
| if (amt != sizeof(header)) { |
| LOGW("write_snapshot_file error writing header %s", strerror(errno)); |
| return errno; |
| } |
| |
| for (int i=0; i<header.fileCount; i++) { |
| const String8& name = snapshot.keyAt(i); |
| FileState file = snapshot.valueAt(i); |
| int nameLen = file.nameLen = name.length(); |
| |
| amt = write(fd, &file, sizeof(file)); |
| if (amt != sizeof(file)) { |
| LOGW("write_snapshot_file error writing header %s", strerror(errno)); |
| return 1; |
| } |
| |
| // filename is not NULL terminated, but it is padded |
| amt = write(fd, name.string(), nameLen); |
| if (amt != nameLen) { |
| LOGW("write_snapshot_file error writing filename %s", strerror(errno)); |
| return 1; |
| } |
| int paddingLen = ROUND_UP[nameLen % 4]; |
| if (paddingLen != 0) { |
| int padding = 0xabababab; |
| amt = write(fd, &padding, paddingLen); |
| if (amt != paddingLen) { |
| LOGW("write_snapshot_file error writing %d bytes of filename padding %s", |
| paddingLen, strerror(errno)); |
| return 1; |
| } |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int |
| write_delete_file(const String8& key) |
| { |
| printf("write_delete_file %s\n", key.string()); |
| return 0; |
| } |
| |
| static int |
| write_update_file(const String8& realFilename, const String8& key) |
| { |
| printf("write_update_file %s (%s)\n", realFilename.string(), key.string()); |
| return 0; |
| } |
| |
| static int |
| compute_crc32(const String8& filename) |
| { |
| const int bufsize = 4*1024; |
| int amt; |
| |
| int fd = open(filename.string(), O_RDONLY); |
| if (fd == -1) { |
| return -1; |
| } |
| |
| char* buf = (char*)malloc(bufsize); |
| int crc = crc32(0L, Z_NULL, 0); |
| |
| while ((amt = read(fd, buf, bufsize)) != 0) { |
| crc = crc32(crc, (Bytef*)buf, amt); |
| } |
| |
| close(fd); |
| free(buf); |
| |
| return crc; |
| } |
| |
| int |
| back_up_files(int oldSnapshotFD, int newSnapshotFD, int oldDataStream, |
| char const* fileBase, char const* const* files, int fileCount) |
| { |
| int err; |
| const String8 base(fileBase); |
| KeyedVector<String8,FileState> oldSnapshot; |
| KeyedVector<String8,FileState> newSnapshot; |
| |
| if (oldSnapshotFD != -1) { |
| err = read_snapshot_file(oldSnapshotFD, &oldSnapshot); |
| if (err != 0) { |
| // On an error, treat this as a full backup. |
| oldSnapshot.clear(); |
| } |
| } |
| |
| for (int i=0; i<fileCount; i++) { |
| String8 name(files[i]); |
| FileState s; |
| struct stat st; |
| String8 realFilename(base); |
| realFilename.appendPath(name); |
| |
| err = stat(realFilename.string(), &st); |
| if (err != 0) { |
| LOGW("Error stating file %s", realFilename.string()); |
| continue; |
| } |
| |
| s.modTime_sec = st.st_mtime; |
| s.modTime_nsec = 0; // workaround sim breakage |
| //s.modTime_nsec = st.st_mtime_nsec; |
| s.size = st.st_size; |
| s.crc32 = compute_crc32(realFilename); |
| |
| newSnapshot.add(name, s); |
| } |
| |
| int n = 0; |
| int N = oldSnapshot.size(); |
| int m = 0; |
| |
| while (n<N && m<fileCount) { |
| const String8& p = oldSnapshot.keyAt(n); |
| const String8& q = newSnapshot.keyAt(m); |
| int cmp = p.compare(q); |
| if (cmp > 0) { |
| // file added |
| String8 realFilename(base); |
| realFilename.appendPath(q); |
| write_update_file(realFilename, q); |
| m++; |
| } |
| else if (cmp < 0) { |
| // file removed |
| write_delete_file(p); |
| n++; |
| } |
| else { |
| // both files exist, check them |
| String8 realFilename(base); |
| realFilename.appendPath(q); |
| const FileState& f = oldSnapshot.valueAt(n); |
| const FileState& g = newSnapshot.valueAt(m); |
| |
| printf("%s\n", q.string()); |
| printf(" new: modTime=%d,%d size=%-3d crc32=0x%08x\n", |
| f.modTime_sec, f.modTime_nsec, f.size, f.crc32); |
| printf(" old: modTime=%d,%d size=%-3d crc32=0x%08x\n", |
| g.modTime_sec, g.modTime_nsec, g.size, g.crc32); |
| if (f.modTime_sec != g.modTime_sec || f.modTime_nsec != g.modTime_nsec |
| || f.size != g.size || f.crc32 != g.crc32) { |
| write_update_file(realFilename, p); |
| } |
| n++; |
| m++; |
| } |
| } |
| |
| // these were deleted |
| while (n<N) { |
| write_delete_file(oldSnapshot.keyAt(n)); |
| n++; |
| } |
| |
| // these were added |
| while (m<fileCount) { |
| const String8& q = newSnapshot.keyAt(m); |
| String8 realFilename(base); |
| realFilename.appendPath(q); |
| write_update_file(realFilename, q); |
| m++; |
| } |
| |
| err = write_snapshot_file(newSnapshotFD, newSnapshot); |
| |
| return 0; |
| } |
| |
| #if TEST_BACKUP_HELPERS |
| |
| #define SCRATCH_DIR "/data/backup_helper_test/" |
| |
| static int |
| write_text_file(const char* path, const char* data) |
| { |
| int amt; |
| int fd; |
| int len; |
| |
| fd = creat(path, 0666); |
| if (fd == -1) { |
| fprintf(stderr, "creat %s failed\n", path); |
| return errno; |
| } |
| |
| len = strlen(data); |
| amt = write(fd, data, len); |
| if (amt != len) { |
| fprintf(stderr, "error (%s) writing to file %s\n", strerror(errno), path); |
| return errno; |
| } |
| |
| close(fd); |
| |
| return 0; |
| } |
| |
| static int |
| compare_file(const char* path, const unsigned char* data, int len) |
| { |
| int fd; |
| int amt; |
| |
| fd = open(path, O_RDONLY); |
| if (fd == -1) { |
| fprintf(stderr, "compare_file error (%s) opening %s\n", strerror(errno), path); |
| return errno; |
| } |
| |
| unsigned char* contents = (unsigned char*)malloc(len); |
| if (contents == NULL) { |
| fprintf(stderr, "malloc(%d) failed\n", len); |
| return ENOMEM; |
| } |
| |
| bool sizesMatch = true; |
| amt = lseek(fd, 0, SEEK_END); |
| if (amt != len) { |
| fprintf(stderr, "compare_file file length should be %d, was %d\n", len, amt); |
| sizesMatch = false; |
| } |
| lseek(fd, 0, SEEK_SET); |
| |
| int readLen = amt < len ? amt : len; |
| amt = read(fd, contents, readLen); |
| if (amt != readLen) { |
| fprintf(stderr, "compare_file read expected %d bytes but got %d\n", len, amt); |
| } |
| |
| bool contentsMatch = true; |
| for (int i=0; i<readLen; i++) { |
| if (data[i] != contents[i]) { |
| if (contentsMatch) { |
| fprintf(stderr, "compare_file contents are different: (index, expected, actual)\n"); |
| contentsMatch = false; |
| } |
| fprintf(stderr, " [%-2d] %02x %02x\n", i, data[i], contents[i]); |
| } |
| } |
| |
| return contentsMatch && sizesMatch ? 0 : 1; |
| } |
| |
| int |
| backup_helper_test_empty() |
| { |
| int err; |
| int fd; |
| KeyedVector<String8,FileState> snapshot; |
| const char* filename = SCRATCH_DIR "backup_helper_test_empty.snap"; |
| |
| system("rm -r " SCRATCH_DIR); |
| mkdir(SCRATCH_DIR, 0777); |
| |
| // write |
| fd = creat(filename, 0666); |
| if (fd == -1) { |
| fprintf(stderr, "error creating %s\n", filename); |
| return 1; |
| } |
| |
| err = write_snapshot_file(fd, snapshot); |
| |
| close(fd); |
| |
| if (err != 0) { |
| fprintf(stderr, "write_snapshot_file reported error %d (%s)\n", err, strerror(err)); |
| return err; |
| } |
| |
| static const unsigned char correct_data[] = { |
| 0x53, 0x6e, 0x61, 0x70, 0x00, 0x00, 0x00, 0x00, |
| 0x46, 0x69, 0x6c, 0x65, 0x10, 0x00, 0x00, 0x00 |
| }; |
| |
| err = compare_file(filename, correct_data, sizeof(correct_data)); |
| if (err != 0) { |
| return err; |
| } |
| |
| // read |
| fd = open(filename, O_RDONLY); |
| if (fd == -1) { |
| fprintf(stderr, "error opening for read %s\n", filename); |
| return 1; |
| } |
| |
| KeyedVector<String8,FileState> readSnapshot; |
| err = read_snapshot_file(fd, &readSnapshot); |
| if (err != 0) { |
| fprintf(stderr, "read_snapshot_file failed %d\n", err); |
| return err; |
| } |
| |
| if (readSnapshot.size() != 0) { |
| fprintf(stderr, "readSnapshot should be length 0\n"); |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| int |
| backup_helper_test_four() |
| { |
| int err; |
| int fd; |
| KeyedVector<String8,FileState> snapshot; |
| const char* filename = SCRATCH_DIR "backup_helper_test_four.snap"; |
| |
| system("rm -r " SCRATCH_DIR); |
| mkdir(SCRATCH_DIR, 0777); |
| |
| // write |
| fd = creat(filename, 0666); |
| if (fd == -1) { |
| fprintf(stderr, "error opening %s\n", filename); |
| return 1; |
| } |
| |
| String8 filenames[4]; |
| FileState states[4]; |
| |
| states[0].modTime_sec = 0xfedcba98; |
| states[0].modTime_nsec = 0xdeadbeef; |
| states[0].size = 0xababbcbc; |
| states[0].crc32 = 0x12345678; |
| states[0].nameLen = -12; |
| filenames[0] = String8("bytes_of_padding"); |
| snapshot.add(filenames[0], states[0]); |
| |
| states[1].modTime_sec = 0x93400031; |
| states[1].modTime_nsec = 0xdeadbeef; |
| states[1].size = 0x88557766; |
| states[1].crc32 = 0x22334422; |
| states[1].nameLen = -1; |
| filenames[1] = String8("bytes_of_padding3"); |
| snapshot.add(filenames[1], states[1]); |
| |
| states[2].modTime_sec = 0x33221144; |
| states[2].modTime_nsec = 0xdeadbeef; |
| states[2].size = 0x11223344; |
| states[2].crc32 = 0x01122334; |
| states[2].nameLen = 0; |
| filenames[2] = String8("bytes_of_padding_2"); |
| snapshot.add(filenames[2], states[2]); |
| |
| states[3].modTime_sec = 0x33221144; |
| states[3].modTime_nsec = 0xdeadbeef; |
| states[3].size = 0x11223344; |
| states[3].crc32 = 0x01122334; |
| states[3].nameLen = 0; |
| filenames[3] = String8("bytes_of_padding__1"); |
| snapshot.add(filenames[3], states[3]); |
| |
| err = write_snapshot_file(fd, snapshot); |
| |
| close(fd); |
| |
| if (err != 0) { |
| fprintf(stderr, "write_snapshot_file reported error %d (%s)\n", err, strerror(err)); |
| return err; |
| } |
| |
| static const unsigned char correct_data[] = { |
| // header |
| 0x53, 0x6e, 0x61, 0x70, 0x04, 0x00, 0x00, 0x00, |
| 0x46, 0x69, 0x6c, 0x65, 0xac, 0x00, 0x00, 0x00, |
| |
| // bytes_of_padding |
| 0x98, 0xba, 0xdc, 0xfe, 0xef, 0xbe, 0xad, 0xde, |
| 0xbc, 0xbc, 0xab, 0xab, 0x78, 0x56, 0x34, 0x12, |
| 0x10, 0x00, 0x00, 0x00, 0x62, 0x79, 0x74, 0x65, |
| 0x73, 0x5f, 0x6f, 0x66, 0x5f, 0x70, 0x61, 0x64, |
| 0x64, 0x69, 0x6e, 0x67, |
| |
| // bytes_of_padding3 |
| 0x31, 0x00, 0x40, 0x93, 0xef, 0xbe, 0xad, 0xde, |
| 0x66, 0x77, 0x55, 0x88, 0x22, 0x44, 0x33, 0x22, |
| 0x11, 0x00, 0x00, 0x00, 0x62, 0x79, 0x74, 0x65, |
| 0x73, 0x5f, 0x6f, 0x66, 0x5f, 0x70, 0x61, 0x64, |
| 0x64, 0x69, 0x6e, 0x67, 0x33, 0xab, 0xab, 0xab, |
| |
| // bytes of padding2 |
| 0x44, 0x11, 0x22, 0x33, 0xef, 0xbe, 0xad, 0xde, |
| 0x44, 0x33, 0x22, 0x11, 0x34, 0x23, 0x12, 0x01, |
| 0x12, 0x00, 0x00, 0x00, 0x62, 0x79, 0x74, 0x65, |
| 0x73, 0x5f, 0x6f, 0x66, 0x5f, 0x70, 0x61, 0x64, |
| 0x64, 0x69, 0x6e, 0x67, 0x5f, 0x32, 0xab, 0xab, |
| |
| // bytes of padding3 |
| 0x44, 0x11, 0x22, 0x33, 0xef, 0xbe, 0xad, 0xde, |
| 0x44, 0x33, 0x22, 0x11, 0x34, 0x23, 0x12, 0x01, |
| 0x13, 0x00, 0x00, 0x00, 0x62, 0x79, 0x74, 0x65, |
| 0x73, 0x5f, 0x6f, 0x66, 0x5f, 0x70, 0x61, 0x64, |
| 0x64, 0x69, 0x6e, 0x67, 0x5f, 0x5f, 0x31, 0xab |
| }; |
| |
| err = compare_file(filename, correct_data, sizeof(correct_data)); |
| if (err != 0) { |
| return err; |
| } |
| |
| // read |
| fd = open(filename, O_RDONLY); |
| if (fd == -1) { |
| fprintf(stderr, "error opening for read %s\n", filename); |
| return 1; |
| } |
| |
| |
| KeyedVector<String8,FileState> readSnapshot; |
| err = read_snapshot_file(fd, &readSnapshot); |
| if (err != 0) { |
| fprintf(stderr, "read_snapshot_file failed %d\n", err); |
| return err; |
| } |
| |
| if (readSnapshot.size() != 4) { |
| fprintf(stderr, "readSnapshot should be length 4 is %d\n", readSnapshot.size()); |
| return 1; |
| } |
| |
| bool matched = true; |
| for (size_t i=0; i<readSnapshot.size(); i++) { |
| const String8& name = readSnapshot.keyAt(i); |
| const FileState state = readSnapshot.valueAt(i); |
| |
| if (name != filenames[i] || states[i].modTime_sec != state.modTime_sec |
| || states[i].modTime_nsec != state.modTime_nsec |
| || states[i].size != state.size || states[i].crc32 != states[i].crc32) { |
| fprintf(stderr, "state %d expected={%d/%d, 0x%08x, 0x%08x, %3d} '%s'\n" |
| " actual={%d/%d, 0x%08x, 0x%08x, %3d} '%s'\n", i, |
| states[i].modTime_sec, states[i].modTime_nsec, states[i].size, states[i].crc32, |
| name.length(), filenames[i].string(), |
| state.modTime_sec, state.modTime_nsec, state.size, state.crc32, state.nameLen, |
| name.string()); |
| matched = false; |
| } |
| } |
| |
| return matched ? 0 : 1; |
| } |
| |
| static int |
| get_mod_time(const char* filename, struct timeval times[2]) |
| { |
| int err; |
| struct stat64 st; |
| err = stat64(filename, &st); |
| if (err != 0) { |
| fprintf(stderr, "stat '%s' failed: %s\n", filename, strerror(errno)); |
| return errno; |
| } |
| times[0].tv_sec = st.st_atime; |
| times[0].tv_usec = st.st_atime_nsec / 1000; |
| times[1].tv_sec = st.st_mtime; |
| times[1].tv_usec = st.st_mtime_nsec / 1000; |
| return 0; |
| } |
| |
| int |
| backup_helper_test_files() |
| { |
| int err; |
| int newSnapshotFD; |
| int oldSnapshotFD; |
| |
| system("rm -r " SCRATCH_DIR); |
| mkdir(SCRATCH_DIR, 0777); |
| mkdir(SCRATCH_DIR "data", 0777); |
| |
| write_text_file(SCRATCH_DIR "data/b", "b\nbb\n"); |
| write_text_file(SCRATCH_DIR "data/c", "c\ncc\n"); |
| write_text_file(SCRATCH_DIR "data/d", "d\ndd\n"); |
| write_text_file(SCRATCH_DIR "data/e", "e\nee\n"); |
| write_text_file(SCRATCH_DIR "data/f", "f\nff\n"); |
| write_text_file(SCRATCH_DIR "data/h", "h\nhh\n"); |
| |
| char const* files_before[] = { |
| "data/b", |
| "data/c", |
| "data/d", |
| "data/e", |
| "data/f" |
| }; |
| |
| newSnapshotFD = creat(SCRATCH_DIR "before.snap", 0666); |
| if (newSnapshotFD == -1) { |
| fprintf(stderr, "error creating: %s\n", strerror(errno)); |
| return errno; |
| } |
| |
| err = back_up_files(-1, newSnapshotFD, 0, SCRATCH_DIR, files_before, 5); |
| if (err != 0) { |
| return err; |
| } |
| |
| close(newSnapshotFD); |
| |
| sleep(3); |
| |
| struct timeval d_times[2]; |
| struct timeval e_times[2]; |
| |
| err = get_mod_time(SCRATCH_DIR "data/d", d_times); |
| err |= get_mod_time(SCRATCH_DIR "data/e", e_times); |
| if (err != 0) { |
| return err; |
| } |
| |
| write_text_file(SCRATCH_DIR "data/a", "a\naa\n"); |
| unlink(SCRATCH_DIR "data/c"); |
| write_text_file(SCRATCH_DIR "data/c", "c\ncc\n"); |
| write_text_file(SCRATCH_DIR "data/d", "dd\ndd\n"); |
| utimes(SCRATCH_DIR "data/d", d_times); |
| write_text_file(SCRATCH_DIR "data/e", "z\nzz\n"); |
| utimes(SCRATCH_DIR "data/e", e_times); |
| write_text_file(SCRATCH_DIR "data/g", "g\ngg\n"); |
| unlink(SCRATCH_DIR "data/f"); |
| |
| char const* files_after[] = { |
| "data/a", // added |
| "data/b", // same |
| "data/c", // different mod time |
| "data/d", // different size (same mod time) |
| "data/e", // different contents (same mod time, same size) |
| "data/g" // added |
| }; |
| |
| oldSnapshotFD = open(SCRATCH_DIR "before.snap", O_RDONLY); |
| if (oldSnapshotFD == -1) { |
| fprintf(stderr, "error opening: %s\n", strerror(errno)); |
| return errno; |
| } |
| |
| newSnapshotFD = creat(SCRATCH_DIR "after.snap", 0666); |
| if (newSnapshotFD == -1) { |
| fprintf(stderr, "error creating: %s\n", strerror(errno)); |
| return errno; |
| } |
| |
| err = back_up_files(oldSnapshotFD, newSnapshotFD, 0, SCRATCH_DIR, files_after, 6); |
| if (err != 0) { |
| return err; |
| } |
| |
| close(oldSnapshotFD); |
| close(newSnapshotFD); |
| |
| return 0; |
| } |
| |
| #endif // TEST_BACKUP_HELPERS |