#include <limits.h>
#include <string.h>
+#include <unistd.h>
+#ifdef HAVE_ALLOCA_H
+# include <alloca.h>
+#else
+# include <stdlib.h>
+#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)
+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;
+
+ wimlib_assert(in_fd->offset == 0);
+
+ if (!filename) {
+ 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);
- 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;
- }
+ 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;
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) {
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;
+
+ DEBUG("Writing %sWIM header at offset %"PRIu64,
+ ((hdr->magic == PWM_MAGIC) ? "pipable " : ""),
+ offset);
- disk_hdr.magic = WIM_MAGIC;
+ 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);
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;
+}
+
+/* Writes the header for a WIM file at the output file descriptor's current
+ * offset. */
+int
+write_wim_header(const struct wim_header *hdr, struct filedes *out_fd)
+{
+ 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));
}
/*
* Initializes the header for a WIM file.
*/
int
-init_header(struct wim_header *hdr, int ctype)
+init_wim_header(struct wim_header *hdr, int ctype)
{
memset(hdr, 0, sizeof(struct wim_header));
switch (ctype) {
hdr->total_parts = 1;
hdr->part_number = 1;
randomize_byte_array(hdr->guid, sizeof(hdr->guid));
+ hdr->magic = WIM_MAGIC;
return 0;
}
{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);
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);