Move dir_entry_xattr_t from libio to libsquashfs

The structure and functions are renamed to sqfs_xattr_* instead,
an additional helper is added to accept an encoded xattr.
Documentation and unit test are added as well.

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

1 files changed, 96 insertions, 0 deletions

diff --git a/lib/sqfs/src/xattr/xattr.c b/lib/sqfs/src/xattr/xattr.c
index 29ecebf..9dc284d 100644
--- a/lib/sqfs/src/xattr/xattr.c
+++ b/lib/sqfs/src/xattr/xattr.c
@@ -8,8 +8,10 @@
 #include "config.h"
 #include "sqfs/xattr.h"
 #include "sqfs/error.h"
+#include "compat.h"
 
 #include <string.h>
+#include <stdlib.h>
 
 static const struct {
 	const char *prefix;
@@ -47,3 +49,97 @@ const char *sqfs_get_xattr_prefix(SQFS_XATTR_TYPE id)
 
 	return NULL;
 }
+
+static sqfs_xattr_t *mkxattr(const char *prefix, const char *key,
+			     const sqfs_u8 *value, size_t value_len)
+{
+	size_t pfx_len = (prefix == NULL) ? 0 : strlen(prefix);
+	size_t key_len = strlen(key);
+	sqfs_xattr_t *out;
+	size_t len;
+
+	/* len = pfx_len + (key_len + 1) + (value_len + 1) + sizeof(*out) */
+	if (SZ_ADD_OV(pfx_len, key_len, &len))
+		return NULL;
+	if (SZ_ADD_OV(len, value_len, &len))
+		return NULL;
+	if (SZ_ADD_OV(len, 2, &len))
+		return NULL;
+	if (SZ_ADD_OV(len, sizeof(*out), &len))
+		return NULL;
+
+	out = calloc(1, len);
+
+	if (out != NULL) {
+		size_t value_offset = pfx_len + key_len + 1;
+
+		out->key = (const char *)out->data;
+		out->value = out->data + value_offset;
+		out->value_len = value_len;
+
+		if (prefix != NULL)
+			memcpy(out->data, prefix, pfx_len);
+
+		memcpy(out->data + pfx_len, key, key_len);
+		memcpy(out->data + value_offset, value, value_len);
+	}
+
+	return out;
+}
+
+sqfs_xattr_t *sqfs_xattr_create(const char *key, const sqfs_u8 *value,
+				size_t value_len)
+{
+	return mkxattr(NULL, key, value, value_len);
+}
+
+int sqfs_xattr_create_prefixed(sqfs_xattr_t **out, sqfs_u16 id,
+			       const char *key, const sqfs_u8 *value,
+			       size_t value_len)
+{
+	const char *prefix = sqfs_get_xattr_prefix(id & (~SQFS_XATTR_FLAG_OOL));
+
+	if (prefix == NULL) {
+		*out = NULL;
+		return SQFS_ERROR_UNSUPPORTED;
+	}
+
+	*out = mkxattr(prefix, key, value, value_len);
+	if (*out == NULL)
+		return SQFS_ERROR_ALLOC;
+
+	return 0;
+}
+
+sqfs_xattr_t *sqfs_xattr_list_copy(const sqfs_xattr_t *list)
+{
+	sqfs_xattr_t *copy = NULL, *copy_last = NULL;
+
+	for (const sqfs_xattr_t *it = list; it != NULL; it = it->next) {
+		sqfs_xattr_t *new = mkxattr(NULL, it->key,
+					    it->value, it->value_len);
+		if (new == NULL) {
+			sqfs_xattr_list_free(copy);
+			return NULL;
+		}
+
+		if (copy_last == NULL) {
+			copy = new;
+		} else {
+			copy_last->next = new;
+		}
+
+		copy_last = new;
+	}
+
+	return copy;
+}
+
+void sqfs_xattr_list_free(sqfs_xattr_t *list)
+{
+	while (list != NULL) {
+		sqfs_xattr_t *old = list;
+		list = list->next;
+		free(old);
+	}
+}