diff options
Diffstat (limited to 'src/restore.c')
| -rw-r--r-- | src/restore.c | 60 |
1 files changed, 31 insertions, 29 deletions
diff --git a/src/restore.c b/src/restore.c index 1c2beae..6318766 100644 --- a/src/restore.c +++ b/src/restore.c @@ -63,7 +63,8 @@ is_reference_file_valid(resources_t *const res, uint32_t sector_size) return 1; } - uint64_t prev_out_offset; + uint64_t prev_out_offset = 0; + bool is_first_reading = true; /* Scan the reference file and check */ for (;;) { @@ -78,18 +79,19 @@ is_reference_file_valid(resources_t *const res, uint32_t sector_size) } else if ((ref_read != 1U) || ferror(res->ref_file)) { print_error("cannot read from reference file: %s", strerror(errno)); return false; - } else if (((out_offset <= prev_out_offset)) || - ((out_offset + sector_size) > out_size)) { - /* The offset must be higher than the previous one and it - * must point into the file - */ - print_error("reference file is not valid"); + } else if (!is_first_reading && (out_offset <= prev_out_offset)) { + print_error("a sector offset points behind the previous offset"); + return false; + } else if ((out_offset + sector_size) > out_size) { + print_error( + "a sector offset points past the end of the output file"); return false; } else if (fseek(res->ref_file, sector_size, SEEK_CUR) != 0) { print_error("cannot seek in reference file: %s", strerror(errno)); return false; } + is_first_reading = false; prev_out_offset = out_offset; } @@ -123,9 +125,9 @@ restore(const options_t *const opts, resources_t *const res) /* Allocate the buffer for data from the reference file */ /* The reference buffer contains also the offsets */ - const size_t ref_buffer_size = - ((opts->buffer_size / opts->sector_size) * sizeof(uint64_t)) + - opts->buffer_size; + const size_t ref_sector_size = sizeof(uint64_t) + opts->sector_size; + const size_t ref_buffer_sector_count = opts->buffer_size / ref_sector_size; + const size_t ref_buffer_size = ref_buffer_sector_count * ref_sector_size; if ((res->ref_buffer = (char *)malloc(ref_buffer_size)) == NULL) { print_error("cannot allocate buffer for reference file data"); @@ -134,34 +136,34 @@ restore(const options_t *const opts, resources_t *const res) /* Restore data from the differential image */ for (;;) { - uint64_t out_offset; /* Read data of the offset and the next sector */ - const size_t ref_read = - fread(res->ref_buffer, ref_buffer_size, 1U, res->ref_file); + const size_t ref_sectors_read = file_read_sectors( + res->ref_file, res->ref_buffer, ref_buffer_size, ref_sector_size); - if (feof(res->ref_file)) { + if (ref_sectors_read == 0) { break; - } else if ((ref_read != 1U) || ferror(res->ref_file)) { - print_error("cannot read from reference file: %s", strerror(errno)); - return 1; } - /* Get offset */ - out_offset = le64toh(*((uint64_t *)res->ref_buffer)); + char *ref_buffer = res->ref_buffer; - if (fseek(res->out_file, out_offset, SEEK_SET) != 0) { - print_error("cannot seek in output file: %s", strerror(errno)); - return 1; - } + for (size_t s = 0; s < ref_sectors_read; ++s) { + const uint64_t out_offset = le64toh(*((uint64_t *)ref_buffer)); + ref_buffer += sizeof(uint64_t); + + if (fseek(res->out_file, out_offset, SEEK_SET) != 0) { + print_error("cannot seek in output file: %s", strerror(errno)); + return 1; + } - /* Write the sector data to the output file */ - const size_t out_written = fwrite(res->ref_buffer + sizeof(out_offset), - opts->sector_size, 1U, res->out_file); + const size_t out_written = + fwrite(ref_buffer, opts->sector_size, 1U, res->out_file); + ref_buffer += opts->sector_size; - if (out_written != 1U) { - print_error("cannot write to output file: %s", strerror(errno)); - return 1; + if (out_written != 1U) { + print_error("cannot write to output file: %s", strerror(errno)); + return 1; + } } } |