libio: add xattr query interface to dir_iterator_t

Again, with a dummy implementation for Unix and Windows backends.

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

6 files changed, 61 insertions, 1 deletions

diff --git a/include/io/dir_iterator.h b/include/io/dir_iterator.h
index 0de135a..377f07e 100644
--- a/include/io/dir_iterator.h
+++ b/include/io/dir_iterator.h
@@ -9,6 +9,7 @@
 
 #include "sqfs/predef.h"
 #include "io/istream.h"
+#include "io/xattr.h"
 
 typedef enum {
 	DIR_ENTRY_FLAG_MOUNT_POINT = 0x0001,
@@ -148,6 +149,16 @@ typedef struct dir_iterator_t {
 	 * @return Zero on success, negative @ref SQFS_ERROR value on failure.
 	 */
 	int (*open_file_ro)(struct dir_iterator_t *it, istream_t **out);
+
+	/**
+	 * @brief Read extended attributes associated with the current entry
+	 *
+	 * @param it A pointer to the iterator itself.
+	 * @param out Returns a linked list of xattr entries.
+	 *
+	 * @return Zero on success, negative @ref SQFS_ERROR value on failure.
+	 */
+	int (*read_xattr)(struct dir_iterator_t *it, dir_entry_xattr_t **out);
 } dir_iterator_t;
 
 enum {
diff --git a/include/io/xattr.h b/include/io/xattr.h
new file mode 100644
index 0000000..d912fad
--- /dev/null
+++ b/include/io/xattr.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * xattr.h
+ *
+ * Copyright (C) 2023 David Oberhollenzer <goliath@infraroot.at>
+ */
+#ifndef IO_XATTR_H
+#define IO_XATTR_H
+
+typedef struct dir_entry_xattr_t {
+	struct dir_entry_xattr_t *next;
+	char *key;
+	sqfs_u8 *value;
+	size_t value_len;
+	char data[];
+} dir_entry_xattr_t;
+
+#endif /* IO_XATTR_H */
diff --git a/lib/io/Makemodule.am b/lib/io/Makemodule.am
index 2fcd1a7..841febf 100644
--- a/lib/io/Makemodule.am
+++ b/lib/io/Makemodule.am
@@ -1,6 +1,6 @@
 libio_a_SOURCES = include/io/istream.h include/io/ostream.h include/io/xfrm.h \
 	include/io/file.h include/io/std.h \
-	include/io/dir_iterator.h \
+	include/io/dir_iterator.h include/io/xattr.h \
 	lib/io/src/internal.h lib/io/src/ostream.c \
 	lib/io/src/istream.c lib/io/src/get_line.c lib/io/src/xfrm/ostream.c \
 	lib/io/src/xfrm/istream.c lib/io/src/dir_tree_iterator.c
diff --git a/lib/io/src/dir_tree_iterator.c b/lib/io/src/dir_tree_iterator.c
index 51d289a..0174d73 100644
--- a/lib/io/src/dir_tree_iterator.c
+++ b/lib/io/src/dir_tree_iterator.c
@@ -284,6 +284,18 @@ static int open_file_ro(dir_iterator_t *base, istream_t **out)
 	return it->top->dir->open_file_ro(it->top->dir, out);
 }
 
+static int read_xattr(dir_iterator_t *base, dir_entry_xattr_t **out)
+{
+	dir_tree_iterator_t *it = (dir_tree_iterator_t *)base;
+
+	if (it->top == NULL) {
+		*out = NULL;
+		return SQFS_ERROR_NO_ENTRY;
+	}
+
+	return it->top->dir->read_xattr(it->top->dir, out);
+}
+
 dir_iterator_t *dir_tree_iterator_create(const char *path,
 					 const dir_tree_cfg_t *cfg)
 {
@@ -315,6 +327,7 @@ dir_iterator_t *dir_tree_iterator_create(const char *path,
 	((dir_iterator_t *)it)->open_subdir = open_subdir;
 	((dir_iterator_t *)it)->ignore_subdir = ignore_subdir;
 	((dir_iterator_t *)it)->open_file_ro = open_file_ro;
+	((dir_iterator_t *)it)->read_xattr = read_xattr;
 
 	return (dir_iterator_t *)it;
 fail:
diff --git a/lib/io/src/unix/dir_iterator.c b/lib/io/src/unix/dir_iterator.c
index d6a7454..fb7edae 100644
--- a/lib/io/src/unix/dir_iterator.c
+++ b/lib/io/src/unix/dir_iterator.c
@@ -137,6 +137,13 @@ static int dir_open_file_ro(dir_iterator_t *it, istream_t **out)
 	return SQFS_ERROR_UNSUPPORTED;
 }
 
+static int dir_read_xattr(dir_iterator_t *it, dir_entry_xattr_t **out)
+{
+	(void)it;
+	*out = NULL;
+	return 0;
+}
+
 static int dir_open_subdir(dir_iterator_t *base, dir_iterator_t **out)
 {
 	const unix_dir_iterator_t *it = (const unix_dir_iterator_t *)base;
@@ -178,6 +185,7 @@ static int dir_open_subdir(dir_iterator_t *base, dir_iterator_t **out)
 	((dir_iterator_t *)sub)->open_subdir = dir_open_subdir;
 	((dir_iterator_t *)sub)->ignore_subdir = dir_ignore_subdir;
 	((dir_iterator_t *)sub)->open_file_ro = dir_open_file_ro;
+	((dir_iterator_t *)sub)->read_xattr = dir_read_xattr;
 
 	*out = (dir_iterator_t *)sub;
 	return 0;
@@ -219,6 +227,7 @@ dir_iterator_t *dir_iterator_create(const char *path)
 	((dir_iterator_t *)it)->open_subdir = dir_open_subdir;
 	((dir_iterator_t *)it)->ignore_subdir = dir_ignore_subdir;
 	((dir_iterator_t *)it)->open_file_ro = dir_open_file_ro;
+	((dir_iterator_t *)it)->read_xattr = dir_read_xattr;
 
 	return (dir_iterator_t *)it;
 }
diff --git a/lib/io/src/win32/dir_iterator.c b/lib/io/src/win32/dir_iterator.c
index d8ac8f3..c9defc7 100644
--- a/lib/io/src/win32/dir_iterator.c
+++ b/lib/io/src/win32/dir_iterator.c
@@ -119,6 +119,13 @@ static int dir_iterator_open_file_ro(dir_iterator_t *it, istream_t **out)
 	return SQFS_ERROR_UNSUPPORTED;
 }
 
+static int dir_iterator_read_xattr(dir_iterator_t *it, dir_entry_xattr_t **out)
+{
+	(void)it;
+	*out = NULL;
+	return 0;
+}
+
 static int dir_iterator_open_subdir(dir_iterator_t *it, dir_iterator_t **out)
 {
 	const dir_iterator_win32_t *dir = (const dir_iterator_win32_t *)it;
@@ -153,6 +160,7 @@ static int dir_iterator_open_subdir(dir_iterator_t *it, dir_iterator_t **out)
 	((dir_iterator_t *)sub)->open_subdir = dir_iterator_open_subdir;
 	((dir_iterator_t *)sub)->ignore_subdir = dir_iterator_ignore_subdir;
 	((dir_iterator_t *)sub)->open_file_ro = dir_iterator_open_file_ro;
+	((dir_iterator_t *)sub)->read_xattr = dir_iterator_read_xattr;
 	sub->is_first = true;
 	sub->state = 0;
 
@@ -214,6 +222,7 @@ dir_iterator_t *dir_iterator_create(const char *path)
 	((dir_iterator_t *)it)->open_subdir = dir_iterator_open_subdir;
 	((dir_iterator_t *)it)->ignore_subdir = dir_iterator_ignore_subdir;
 	((dir_iterator_t *)it)->open_file_ro = dir_iterator_open_file_ro;
+	((dir_iterator_t *)it)->read_xattr = dir_iterator_read_xattr;
 	it->is_first = true;
 	it->state = 0;