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Diffstat (limited to 'i/pc104/initrd/conf/busybox/archival/libunarchive/check_header_gzip.c')
-rw-r--r--i/pc104/initrd/conf/busybox/archival/libunarchive/check_header_gzip.c59
1 files changed, 59 insertions, 0 deletions
diff --git a/i/pc104/initrd/conf/busybox/archival/libunarchive/check_header_gzip.c b/i/pc104/initrd/conf/busybox/archival/libunarchive/check_header_gzip.c
new file mode 100644
index 0000000..66aa574
--- /dev/null
+++ b/i/pc104/initrd/conf/busybox/archival/libunarchive/check_header_gzip.c
@@ -0,0 +1,59 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+#include "libbb.h"
+#include "unarchive.h" /* for external decl of check_header_gzip_or_die */
+
+void check_header_gzip_or_die(int src_fd)
+{
+ union {
+ unsigned char raw[8];
+ struct {
+ unsigned char method;
+ unsigned char flags;
+ unsigned int mtime;
+ unsigned char xtra_flags;
+ unsigned char os_flags;
+ } formatted;
+ } header;
+
+ xread(src_fd, header.raw, 8);
+
+ /* Check the compression method */
+ if (header.formatted.method != 8) {
+ bb_error_msg_and_die("unknown compression method %d",
+ header.formatted.method);
+ }
+
+ if (header.formatted.flags & 0x04) {
+ /* bit 2 set: extra field present */
+ unsigned extra_short;
+
+ extra_short = xread_char(src_fd) + (xread_char(src_fd) << 8);
+ while (extra_short > 0) {
+ /* Ignore extra field */
+ xread_char(src_fd);
+ extra_short--;
+ }
+ }
+
+ /* Discard original name if any */
+ if (header.formatted.flags & 0x08) {
+ /* bit 3 set: original file name present */
+ while (xread_char(src_fd) != 0);
+ }
+
+ /* Discard file comment if any */
+ if (header.formatted.flags & 0x10) {
+ /* bit 4 set: file comment present */
+ while (xread_char(src_fd) != 0);
+ }
+
+ /* Read the header checksum */
+ if (header.formatted.flags & 0x02) {
+ xread_char(src_fd);
+ xread_char(src_fd);
+ }
+}