Cleanup: sqfs2tar: break up and simplify the repacking code

 - Move the xattr extraction and repacking to xattr.c
 - Don't on-the-fly delete the tar xattr list, use the function
   from libtar.a
 - Split minor tasks into static helper functions
   - creating a libtar xattr struct from libsqfs xattr data
   - finding a hard link entry from current path and inode number

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

1 files changed, 91 insertions, 0 deletions

diff --git a/bin/sqfs2tar/xattr.c b/bin/sqfs2tar/xattr.c
new file mode 100644
index 0000000..9a9ec82
--- /dev/null
+++ b/bin/sqfs2tar/xattr.c
@@ -0,0 +1,91 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * xattr.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "sqfs2tar.h"
+
+static tar_xattr_t *mkxattr(const sqfs_xattr_entry_t *key,
+			    const sqfs_xattr_value_t *value)
+{
+	tar_xattr_t *ent;
+
+	ent = calloc(1, sizeof(*ent) + strlen((const char *)key->key) +
+		     value->size + 2);
+
+	if (ent == NULL) {
+		perror("creating xattr entry");
+		return NULL;
+	}
+
+	ent->key = ent->data;
+	ent->value = (sqfs_u8 *)ent->key + strlen((const char *)key->key) + 1;
+	ent->value_len = value->size;
+
+	strcpy(ent->key, (const char *)key->key);
+	memcpy(ent->value, value->value, value->size + 1);
+	return ent;
+}
+
+int get_xattrs(const char *name, const sqfs_inode_generic_t *inode,
+	       tar_xattr_t **out)
+{
+	tar_xattr_t *list = NULL, *ent;
+	sqfs_xattr_value_t *value;
+	sqfs_xattr_entry_t *key;
+	sqfs_xattr_id_t desc;
+	sqfs_u32 index;
+	size_t i;
+	int ret;
+
+	if (xr == NULL)
+		return 0;
+
+	sqfs_inode_get_xattr_index(inode, &index);
+	if (index == 0xFFFFFFFF)
+		return 0;
+
+	ret = sqfs_xattr_reader_get_desc(xr, index, &desc);
+	if (ret) {
+		sqfs_perror(name, "resolving xattr index", ret);
+		return -1;
+	}
+
+	ret = sqfs_xattr_reader_seek_kv(xr, &desc);
+	if (ret) {
+		sqfs_perror(name, "locating xattr key-value pairs", ret);
+		return -1;
+	}
+
+	for (i = 0; i < desc.count; ++i) {
+		ret = sqfs_xattr_reader_read_key(xr, &key);
+		if (ret) {
+			sqfs_perror(name, "reading xattr key", ret);
+			goto fail;
+		}
+
+		ret = sqfs_xattr_reader_read_value(xr, key, &value);
+		if (ret) {
+			sqfs_perror(name, "reading xattr value", ret);
+			free(key);
+			goto fail;
+		}
+
+		ent = mkxattr(key, value);
+		free(key);
+		free(value);
+
+		if (ent == NULL)
+			goto fail;
+
+		ent->next = list;
+		list = ent;
+	}
+
+	*out = list;
+	return 0;
+fail:
+	free_xattr_list(list);
+	return -1;
+}