X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Fheader.c;h=4924b505dfba8f6e455733ddcb0e67722ba70e9f;hp=5a665fc25113db71eec709ca697cd063839c5943;hb=5944d11442d5df847c3393951a8563412d16e640;hpb=f5d26d6005ba759762bec8c7cd45a738e577a8a7 diff --git a/src/header.c b/src/header.c index 5a665fc2..4924b505 100644 --- a/src/header.c +++ b/src/header.c @@ -38,126 +38,95 @@ #include #include +#include +#ifdef HAVE_ALLOCA_H +# include +#else +# include +#endif -/* WIM magic characters, translated to a single 64-bit little endian number. */ -#define WIM_MAGIC \ - cpu_to_le64(((u64)'M' << 0) | \ - ((u64)'S' << 8) | \ - ((u64)'W' << 16) | \ - ((u64)'I' << 24) | \ - ((u64)'M' << 32) | \ - ((u64)'\0' << 40) | \ - ((u64)'\0' << 48) | \ - ((u64)'\0' << 54)) - -/* On-disk format of the WIM header. */ -struct wim_header_disk { - - /* Magic characters "MSWIM\0\0\0" */ - le64 magic; - - /* Size of the WIM header, in bytes; WIM_HEADER_DISK_SIZE expected - * (currently the only supported value). */ - u32 hdr_size; - - /* Version of the WIM file; WIM_VERSION expected (currently the only - * supported value). */ - u32 wim_version; - - /* Flags for the WIM file (WIM_HDR_FLAG_*) */ - u32 wim_flags; - - /* Uncompressed chunk size of resources in the WIM. 0 if the WIM is - * uncompressed. If compressed, WIM_CHUNK_SIZE is expected (currently - * the only supported value). */ - u32 chunk_size; - - /* Globally unique identifier for the WIM file. Basically a bunch of - * random bytes. */ - u8 guid[WIM_GID_LEN]; - - /* Number of this WIM part in the split WIM file, indexed from 1, or 1 - * if the WIM is not split. */ - u16 part_number; - - /* Total number of parts of the split WIM file, or 1 if the WIM is not - * split. */ - u16 total_parts; - - /* Number of images in the WIM. */ - u32 image_count; - - /* Location and size of the WIM's lookup table. */ - struct resource_entry_disk lookup_table_res_entry; - - /* Location and size of the WIM's XML data. */ - struct resource_entry_disk xml_data_res_entry; - - /* Location and size of metadata resource for the bootable image of the - * WIM, or all zeroes if no image is bootable. */ - struct resource_entry_disk boot_metadata_res_entry; - - /* 1-based index of the bootable image of the WIM, or 0 if no image is - * bootable. */ - u32 boot_idx; - - /* Location and size of the WIM's integrity table, or all zeroes if the - * WIM has no integrity table. - * - * Note the integrity_table_res_entry here is 4-byte aligned even though - * it would ordinarily be 8-byte aligned--- hence, the _packed_attribute - * on the `struct wim_header_disk' is essential. */ - struct resource_entry_disk integrity_table_res_entry; - - /* Unused bytes. */ - u8 unused[60]; -} _packed_attribute; - -/* Reads the header from a WIM file. */ +/* + * Reads the header from a WIM file. + * + * @filename + * Name of the WIM file (for error/debug messages only), or NULL if reading + * directly from file descriptor. + * @in_fd + * File descriptor, positioned at offset 0, to read the header from. + * @hdr + * Structure to read the header into. + * + * Return values: + * WIMLIB_ERR_SUCCESS (0) + * WIMLIB_ERR_IMAGE_COUNT + * WIMLIB_ERR_INVALID_CHUNK_SIZE + * WIMLIB_ERR_INVALID_PART_NUMBER + * WIMLIB_ERR_NOT_A_WIM_FILE + * WIMLIB_ERR_READ + * WIMLIB_ERR_UNEXPECTED_END_OF_FILE + * WIMLIB_ERR_UNKNOWN_VERSION + */ int -read_header(const tchar *filename, int in_fd, - struct wim_header *hdr, int open_flags) +read_wim_header(const tchar *filename, struct filedes *in_fd, + struct wim_header *hdr) { struct wim_header_disk disk_hdr _aligned_attribute(8); + int ret; + tchar *pipe_str; - DEBUG("Reading WIM header from \"%"TS"\"", filename); + wimlib_assert(in_fd->offset == 0); - if (full_pread(in_fd, &disk_hdr, sizeof(disk_hdr), 0) != sizeof(disk_hdr)) { - ERROR_WITH_ERRNO("\"%"TS"\": Error reading header", filename); - return WIMLIB_ERR_READ; + if (filename == NULL) { + pipe_str = alloca(40); + tsprintf(pipe_str, T("[fd %d]"), in_fd->fd); + filename = pipe_str; } + BUILD_BUG_ON(sizeof(struct wim_header_disk) != WIM_HEADER_DISK_SIZE); + + DEBUG("Reading WIM header from \"%"TS"\"", filename); + + ret = full_read(in_fd, &disk_hdr, sizeof(disk_hdr)); + if (ret) + goto read_error; + if (disk_hdr.magic != WIM_MAGIC) { - ERROR("\"%"TS"\": Invalid magic characters in header", filename); - return WIMLIB_ERR_NOT_A_WIM_FILE; + if (disk_hdr.magic == PWM_MAGIC) { + /* Pipable WIM: Use header at end instead, unless + * actually reading from a pipe. */ + if (!in_fd->is_pipe) { + lseek(in_fd->fd, -WIM_HEADER_DISK_SIZE, SEEK_END); + ret = full_read(in_fd, &disk_hdr, sizeof(disk_hdr)); + if (ret) + goto read_error; + } + } else { + ERROR("\"%"TS"\": Invalid magic characters in header", filename); + return WIMLIB_ERR_NOT_A_WIM_FILE; + } } + hdr->magic = disk_hdr.magic; - BUILD_BUG_ON(sizeof(struct wim_header_disk) != WIM_HEADER_DISK_SIZE); if (le32_to_cpu(disk_hdr.hdr_size) != sizeof(struct wim_header_disk)) { ERROR("\"%"TS"\": Header size is invalid (%u bytes)", filename, le32_to_cpu(disk_hdr.hdr_size)); - return WIMLIB_ERR_INVALID_HEADER_SIZE; + return WIMLIB_ERR_INVALID_HEADER; } if (le32_to_cpu(disk_hdr.wim_version) != WIM_VERSION) { ERROR("\"%"TS"\": The WIM header says the WIM version is %u, " "but wimlib only knows about version %u", filename, le32_to_cpu(disk_hdr.wim_version), WIM_VERSION); + if (le32_to_cpu(disk_hdr.wim_flags) & WIM_HDR_FLAG_COMPRESS_LZMS) { + ERROR("\"%"TS"\": This WIM uses LZMS compression, " + "which is not supported by wimlib.", filename); + } return WIMLIB_ERR_UNKNOWN_VERSION; } hdr->flags = le32_to_cpu(disk_hdr.wim_flags); - if (le32_to_cpu(disk_hdr.chunk_size) != WIM_CHUNK_SIZE && - (hdr->flags & WIM_HDR_FLAG_COMPRESSION)) { - ERROR("\"%"TS"\": Unexpected chunk size of %u! Ask the author to " - "implement support for other chunk sizes.", - filename, le32_to_cpu(disk_hdr.chunk_size)); - ERROR("(Or it might just be that the WIM header is invalid.)"); - return WIMLIB_ERR_INVALID_CHUNK_SIZE; - } - + hdr->chunk_size = le32_to_cpu(disk_hdr.chunk_size); memcpy(hdr->guid, disk_hdr.guid, WIM_GID_LEN); - hdr->part_number = le16_to_cpu(disk_hdr.part_number); hdr->total_parts = le16_to_cpu(disk_hdr.total_parts); @@ -169,13 +138,6 @@ read_header(const tchar *filename, int in_fd, return WIMLIB_ERR_INVALID_PART_NUMBER; } - if (!(open_flags & WIMLIB_OPEN_FLAG_SPLIT_OK) && hdr->total_parts != 1) - { - ERROR("\"%"TS"\": This WIM is part %u of a %u-part WIM", - filename, hdr->part_number, hdr->total_parts); - return WIMLIB_ERR_SPLIT_UNSUPPORTED; - } - hdr->image_count = le32_to_cpu(disk_hdr.image_count); DEBUG("part_number = %u, total_parts = %u, image_count = %u", @@ -193,28 +155,34 @@ read_header(const tchar *filename, int in_fd, hdr->boot_idx = le32_to_cpu(disk_hdr.boot_idx); get_resource_entry(&disk_hdr.integrity_table_res_entry, &hdr->integrity); return 0; + +read_error: + ERROR_WITH_ERRNO("\"%"TS"\": Error reading header", filename); + return ret; } -/* - * Writes the header for a WIM file. - * - * @hdr: A pointer to a struct wim_header structure that describes the header. - * @out_fd: The file descriptor to the WIM file, opened for writing. - * - * Returns zero on success, nonzero on failure. - */ +/* Writes the header for a WIM file at the specified offset. If the offset + * specified is the current one, the position is advanced by the size of the + * header. */ int -write_header(const struct wim_header *hdr, int out_fd) +write_wim_header_at_offset(const struct wim_header *hdr, struct filedes *out_fd, + off_t offset) { struct wim_header_disk disk_hdr _aligned_attribute(8); - DEBUG("Writing WIM header."); + int ret; - disk_hdr.magic = WIM_MAGIC; + DEBUG("Writing %sWIM header at offset %"PRIu64, + ((hdr->magic == PWM_MAGIC) ? "pipable " : ""), + offset); + + disk_hdr.magic = hdr->magic; disk_hdr.hdr_size = cpu_to_le32(sizeof(struct wim_header_disk)); disk_hdr.wim_version = cpu_to_le32(WIM_VERSION); disk_hdr.wim_flags = cpu_to_le32(hdr->flags); - disk_hdr.chunk_size = cpu_to_le32((hdr->flags & WIM_HDR_FLAG_COMPRESSION) ? - WIM_CHUNK_SIZE : 0); + if (hdr->flags & WIM_HDR_FLAG_COMPRESSION) + disk_hdr.chunk_size = cpu_to_le32(hdr->chunk_size); + else + disk_hdr.chunk_size = 0; memcpy(disk_hdr.guid, hdr->guid, WIM_GID_LEN); disk_hdr.part_number = cpu_to_le16(hdr->part_number); @@ -227,37 +195,72 @@ write_header(const struct wim_header *hdr, int out_fd) put_resource_entry(&hdr->integrity, &disk_hdr.integrity_table_res_entry); memset(disk_hdr.unused, 0, sizeof(disk_hdr.unused)); - if (full_pwrite(out_fd, &disk_hdr, sizeof(disk_hdr), 0) != sizeof(disk_hdr)) { + if (offset == out_fd->offset) + ret = full_write(out_fd, &disk_hdr, sizeof(disk_hdr)); + else + ret = full_pwrite(out_fd, &disk_hdr, sizeof(disk_hdr), offset); + if (ret) ERROR_WITH_ERRNO("Failed to write WIM header"); - return WIMLIB_ERR_WRITE; - } - DEBUG("Done writing WIM header"); - return 0; + return ret; } -/* - * Initializes the header for a WIM file. - */ +/* Writes the header for a WIM file at the output file descriptor's current + * offset. */ int -init_header(struct wim_header *hdr, int ctype) +write_wim_header(const struct wim_header *hdr, struct filedes *out_fd) { - memset(hdr, 0, sizeof(struct wim_header)); + return write_wim_header_at_offset(hdr, out_fd, out_fd->offset); +} + +/* Update just the wim_flags field. */ +int +write_wim_header_flags(u32 hdr_flags, struct filedes *out_fd) +{ + le32 flags = cpu_to_le32(hdr_flags); + + return full_pwrite(out_fd, &flags, sizeof(flags), + offsetof(struct wim_header_disk, wim_flags)); +} + +int +set_wim_hdr_cflags(int ctype, struct wim_header *hdr) +{ + hdr->flags &= ~(WIM_HDR_FLAG_COMPRESSION | + WIM_HDR_FLAG_COMPRESS_LZX | + WIM_HDR_FLAG_COMPRESS_RESERVED | + WIM_HDR_FLAG_COMPRESS_XPRESS | + WIM_HDR_FLAG_COMPRESS_LZMS); switch (ctype) { + case WIMLIB_COMPRESSION_TYPE_NONE: - hdr->flags = 0; - break; + return 0; + case WIMLIB_COMPRESSION_TYPE_LZX: - hdr->flags = WIM_HDR_FLAG_COMPRESSION | - WIM_HDR_FLAG_COMPRESS_LZX; - break; + hdr->flags |= WIM_HDR_FLAG_COMPRESSION | WIM_HDR_FLAG_COMPRESS_LZX; + return 0; + case WIMLIB_COMPRESSION_TYPE_XPRESS: - hdr->flags = WIM_HDR_FLAG_COMPRESSION | - WIM_HDR_FLAG_COMPRESS_XPRESS; - break; + hdr->flags |= WIM_HDR_FLAG_COMPRESSION | WIM_HDR_FLAG_COMPRESS_XPRESS; + return 0; + default: + return WIMLIB_ERR_INVALID_COMPRESSION_TYPE; + } +} + +/* + * Initializes the header for a WIM file. + */ +int +init_wim_header(struct wim_header *hdr, int ctype, u32 chunk_size) +{ + memset(hdr, 0, sizeof(struct wim_header)); + hdr->magic = WIM_MAGIC; + if (set_wim_hdr_cflags(ctype, hdr)) { ERROR("Invalid compression type specified (%d)", ctype); return WIMLIB_ERR_INVALID_COMPRESSION_TYPE; } + hdr->chunk_size = chunk_size; hdr->total_parts = 1; hdr->part_number = 1; randomize_byte_array(hdr->guid, sizeof(hdr->guid)); @@ -282,11 +285,11 @@ struct hdr_flag hdr_flags[] = { {WIM_HDR_FLAG_COMPRESS_XPRESS, "COMPRESS_XPRESS"}, }; -/* Prints information from the header of the WIM file associated with @w. */ +/* API function documented in wimlib.h */ WIMLIBAPI void -wimlib_print_header(const WIMStruct *w) +wimlib_print_header(const WIMStruct *wim) { - const struct wim_header *hdr = &w->hdr; + const struct wim_header *hdr = &wim->hdr; tprintf(T("Magic Characters = MSWIM\\000\\000\\000\n")); tprintf(T("Header Size = %u\n"), WIM_HEADER_DISK_SIZE); @@ -297,12 +300,12 @@ wimlib_print_header(const WIMStruct *w) if (hdr_flags[i].flag & hdr->flags) tprintf(T(" WIM_HDR_FLAG_%s is set\n"), hdr_flags[i].name); - tprintf(T("Chunk Size = %u\n"), WIM_CHUNK_SIZE); + tprintf(T("Chunk Size = %u\n"), wim->hdr.chunk_size); tfputs (T("GUID = "), stdout); print_byte_field(hdr->guid, WIM_GID_LEN, stdout); tputchar(T('\n')); - tprintf(T("Part Number = %hu\n"), w->hdr.part_number); - tprintf(T("Total Parts = %hu\n"), w->hdr.total_parts); + tprintf(T("Part Number = %hu\n"), wim->hdr.part_number); + tprintf(T("Total Parts = %hu\n"), wim->hdr.total_parts); tprintf(T("Image Count = %u\n"), hdr->image_count); tprintf(T("Lookup Table Size = %"PRIu64"\n"), (u64)hdr->lookup_table_res_entry.size);