Split generic tar code off to static library

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 65 insertions, 0 deletions

diff --git a/include/tar.h b/include/tar.h
new file mode 100644
index 0000000..7862235
--- /dev/null
+++ b/include/tar.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#ifndef TAR_H
+#define TAR_H
+
+#include <sys/stat.h>
+#include <stdbool.h>
+
+typedef struct {
+	char name[100];
+	char mode[8];
+	char uid[8];
+	char gid[8];
+	char size[12];
+	char mtime[12];
+	char chksum[8];
+	char typeflag;
+	char linkname[100];
+	char magic[6];
+	char version[2];
+	char uname[32];
+	char gname[32];
+	char devmajor[8];
+	char devminor[8];
+	char prefix[155];
+	char padding[12];
+} tar_header_t;
+
+typedef struct {
+	struct stat sb;
+	char *name;
+	char *link_target;
+	bool unknown_record;
+} tar_header_decoded_t;
+
+#define TAR_TYPE_FILE '0'
+#define TAR_TYPE_LINK '1'
+#define TAR_TYPE_SLINK '2'
+#define TAR_TYPE_CHARDEV '3'
+#define TAR_TYPE_BLOCKDEV '4'
+#define TAR_TYPE_DIR '5'
+#define TAR_TYPE_FIFO '6'
+
+#define TAR_TYPE_PAX 'x'
+
+#define TAR_MAGIC "ustar"
+#define TAR_VERSION "00"
+
+/*
+  Returns < 0 on failure, > 0 if cannot encode, 0 on success.
+  Prints error/warning messages to stderr.
+*/
+int write_tar_header(int fd, const struct stat *sb, const char *name,
+		     const char *slink_target);
+
+/* calcuate and skip the zero padding */
+int skip_padding(int fd, uint64_t size);
+
+/* round up to block size and skip the entire entry */
+int skip_entry(int fd, uint64_t size);
+
+int read_header(int fd, tar_header_decoded_t *out);
+
+void clear_header(tar_header_decoded_t *hdr);
+
+#endif /* TAR_H */