xattr_iterator: return bool instead of int for _next()

This commit changes the return type of sqsh_xattr_iterator_next() from
int to bool. The return value is now used to indicate whether there is
more data to read from the xattr iterator. The error code is now stored
in a pointer to an int instead of being returned directly.

fuzzer/simple.c

@@ -53,7 +53,7 @@ read_file(struct SqshDirectoryIterator *iter) {
 	if (rv < 0) {
 		goto out;
 	}
-	while ((rv = sqsh_xattr_iterator_next(&xattr_iter)) > 0) {
+	while (sqsh_xattr_iterator_next(&xattr_iter, &rv)) {
 		char *fullname = sqsh_xattr_iterator_fullname_dup(&xattr_iter);
 		free(fullname);
 		sqsh_xattr_iterator_value(&xattr_iter);

include/sqsh_xattr.h

@@ -74,10 +74,14 @@ sqsh_xattr_iterator_new(const struct SqshFile *file, int *err);
  * @brief Advances the iterator to the next xattr.
  *
  * @param[in,out] iterator The iterator to advance.
+ * @param[out]    err      Pointer to an int where the error code will be
+ * stored.
  *
- * @return 0 on success, a negative value on error.
+ * @retval true  When the iterator was advanced.
+ * @retval false When the end of the xattrs list was reached or an error occured.
  */
-SQSH_NO_UNUSED int sqsh_xattr_iterator_next(struct SqshXattrIterator *iterator);
+SQSH_NO_UNUSED bool
+sqsh_xattr_iterator_next(struct SqshXattrIterator *iterator, int *err);
 
 /**
  * @memberof SqshXattrIterator

lib/xattr/xattr_iterator.c

@@ -191,19 +191,19 @@ xattr_value_indirect_load(struct SqshXattrIterator *iterator) {
 	return rv;
 }
 
-int
-sqsh_xattr_iterator_next(struct SqshXattrIterator *iterator) {
+bool
+sqsh_xattr_iterator_next(struct SqshXattrIterator *iterator, int *err) {
 	int rv = 0;
 	size_t size = SQSH_SIZEOF_XATTR_KEY + SQSH_SIZEOF_XATTR_VALUE;
+	bool has_next = false;
 
 	sqsh__metablock_reader_cleanup(&iterator->out_of_line_value);
 
 	if (iterator->remaining_entries == 0) {
 		if (iterator->remaining_size != 0) {
 			rv = -SQSH_ERROR_XATTR_SIZE_MISMATCH;
-			goto out;
 		}
-		return 0;
+		goto out;
 	}
 
 	/* Load Key Header */
@@ -250,11 +250,13 @@ sqsh_xattr_iterator_next(struct SqshXattrIterator *iterator) {
 		goto out;
 	}
 
-	rv = iterator->remaining_entries;
-
 	iterator->remaining_entries--;
+	has_next = true;
 out:
-	return rv;
+	if (err != NULL) {
+		*err = rv;
+	}
+	return has_next;
 }
 
 uint16_t
@@ -303,7 +305,7 @@ sqsh_xattr_iterator_lookup(
 		struct SqshXattrIterator *iterator, const char *name) {
 	int rv = 0, rv_cmp = 0;
 
-	while ((rv = sqsh_xattr_iterator_next(iterator)) > 0) {
+	while (sqsh_xattr_iterator_next(iterator, &rv)) {
 		rv_cmp = sqsh_xattr_iterator_fullname_cmp(iterator, name);
 		if (rv_cmp == 0) {
 			return 0;

test/xattr/xattr_iterator.c

@@ -89,8 +89,9 @@ load_xattr(void) {
 	assert(rv == 0);
 	assert(iterator != NULL);
 
-	rv = sqsh_xattr_iterator_next(iterator);
-	assert(rv > 0);
+	bool has_next = sqsh_xattr_iterator_next(iterator, &rv);
+	assert(rv == 0);
+	assert(has_next == true);
 	size_t size = sqsh_xattr_iterator_name_size(iterator);
 	assert(size == 3);
 	const char *name = sqsh_xattr_iterator_name(iterator);
@@ -102,8 +103,9 @@ load_xattr(void) {
 	const char *prefix = sqsh_xattr_iterator_prefix(iterator);
 	assert(strcmp(prefix, "user.") == 0);
 
-	rv = sqsh_xattr_iterator_next(iterator);
-	assert(rv > 0);
+	has_next = sqsh_xattr_iterator_next(iterator, &rv);
+	assert(rv == 0);
+	assert(has_next == true);
 	size = sqsh_xattr_iterator_name_size(iterator);
 	assert(size == 3);
 	name = sqsh_xattr_iterator_name(iterator);
@@ -115,8 +117,9 @@ load_xattr(void) {
 	prefix = sqsh_xattr_iterator_prefix(iterator);
 	assert(strcmp(prefix, "trusted.") == 0);
 
-	rv = sqsh_xattr_iterator_next(iterator);
-	assert(rv > 0);
+	has_next = sqsh_xattr_iterator_next(iterator, &rv);
+	assert(rv == 0);
+	assert(has_next == true);
 	size = sqsh_xattr_iterator_name_size(iterator);
 	assert(size == 3);
 	name = sqsh_xattr_iterator_name(iterator);
@@ -128,8 +131,9 @@ load_xattr(void) {
 	prefix = sqsh_xattr_iterator_prefix(iterator);
 	assert(strcmp(prefix, "security.") == 0);
 
-	rv = sqsh_xattr_iterator_next(iterator);
+	has_next = sqsh_xattr_iterator_next(iterator, &rv);
 	assert(rv == 0);
+	assert(has_next == false);
 
 	sqsh_xattr_iterator_free(iterator);
 	sqsh__file_cleanup(&file);
@@ -180,8 +184,9 @@ load_xattr_indirect(void) {
 	assert(rv == 0);
 	assert(iterator != NULL);
 
-	rv = sqsh_xattr_iterator_next(iterator);
-	assert(rv > 0);
+	bool has_next = sqsh_xattr_iterator_next(iterator, &rv);
+	assert(rv == 0);
+	assert(has_next == true);
 	size_t size = sqsh_xattr_iterator_name_size(iterator);
 	assert(size == 3);
 	const char *name = sqsh_xattr_iterator_name(iterator);
@@ -191,8 +196,9 @@ load_xattr_indirect(void) {
 	const char *value = sqsh_xattr_iterator_value(iterator);
 	assert(memcmp(value, "123", size) == 0);
 
-	rv = sqsh_xattr_iterator_next(iterator);
+	has_next = sqsh_xattr_iterator_next(iterator, &rv);
 	assert(rv == 0);
+	assert(has_next == false);
 
 	sqsh_xattr_iterator_free(iterator);
 	sqsh__file_cleanup(&file);

tools/fs2.c

@@ -248,7 +248,7 @@ fs_listxattr(const char *path, char *buf, size_t size) {
 	}
 
 	iterator = sqsh_xattr_iterator_new(file, &rv);
-	while ((rv = sqsh_xattr_iterator_next(iterator)) > 0) {
+	while (sqsh_xattr_iterator_next(iterator, &rv) > 0) {
 		const char *prefix = sqsh_xattr_iterator_prefix(iterator);
 		size_t prefix_len = sqsh_xattr_iterator_prefix_size(iterator);
 		const char *name = sqsh_xattr_iterator_name(iterator);
@@ -264,6 +264,9 @@ fs_listxattr(const char *path, char *buf, size_t size) {
 		buf[pos] = '\0';
 		pos++;
 	}
+	if (rv < 0) {
+		goto out;
+	}
 
 	rv = pos;
 out:

tools/fs3.c

@@ -421,7 +421,7 @@ fs_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size) {
 	}
 
 	p = buf;
-	while ((rv = sqsh_xattr_iterator_next(iterator)) > 0) {
+	while (sqsh_xattr_iterator_next(iterator, &rv)) {
 		prefix = sqsh_xattr_iterator_prefix(iterator);
 		if (prefix == NULL) {
 			fuse_reply_err(req, EIO);

tools/xattr.c

@@ -82,7 +82,7 @@ fattr_path(struct SqshArchive *archive, char *path) {
 		goto out;
 	}
 
-	while ((rv = sqsh_xattr_iterator_next(iter)) > 0) {
+	while (sqsh_xattr_iterator_next(iter, &rv)) {
 		const char *prefix = sqsh_xattr_iterator_prefix(iter);
 		uint16_t prefix_len = sqsh_xattr_iterator_prefix_size(iter);
 		const char *name = sqsh_xattr_iterator_name(iter);