1 files changed, 118 insertions, 0 deletions
diff --git a/lib/e2p/encoding.c b/lib/e2p/encoding.c
new file mode 100644
index 0000000..24266fc
--- /dev/null
+++ b/lib/e2p/encoding.c
@@ -0,0 +1,118 @@
+/*
+ * encoding.c --- convert between encoding magic numbers and strings
+ *
+ * Copyright (C) 2018  Collabora Ltd.
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Library
+ * General Public License, version 2.
+ * %End-Header%
+ */
+
+#include "config.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+
+#include "e2p.h"
+
+#define ARRAY_SIZE(array)			\
+        (sizeof(array) / sizeof(array[0]))
+
+static const struct {
+	const char *name;
+	__u16 encoding_magic;
+	__u16 default_flags;
+
+} ext4_encoding_map[] = {
+	{
+		.encoding_magic = EXT4_ENC_UTF8_12_1,
+		.name = "utf8-12.1",
+		.default_flags = 0,
+	},
+	{
+		.encoding_magic = EXT4_ENC_UTF8_12_1,
+		.name = "utf8",
+		.default_flags = 0,
+	},
+};
+
+static const struct enc_flags {
+	__u16 flag;
+	const char *param;
+} encoding_flags[] = {
+	{ EXT4_ENC_STRICT_MODE_FL, "strict" },
+};
+
+/* Return a positive number < 0xff indicating the encoding magic number
+ * or a negative value indicating error. */
+int e2p_str2encoding(const char *string)
+{
+	unsigned int i;
+
+	for (i = 0 ; i < ARRAY_SIZE(ext4_encoding_map); i++)
+		if (!strcmp(string, ext4_encoding_map[i].name))
+			return ext4_encoding_map[i].encoding_magic;
+
+	return -EINVAL;
+}
+
+/* Return the name of an encoding or NULL */
+const char *e2p_encoding2str(int encoding)
+{
+	unsigned int i;
+	static char buf[32];
+
+	for (i = 0 ; i < ARRAY_SIZE(ext4_encoding_map); i++)
+		if (ext4_encoding_map[i].encoding_magic == encoding)
+			return ext4_encoding_map[i].name;
+	sprintf(buf, "UNKNOWN_ENCODING_%d", encoding);
+	return buf;
+}
+
+int e2p_get_encoding_flags(int encoding)
+{
+	unsigned int i;
+
+	for (i = 0 ; i < ARRAY_SIZE(ext4_encoding_map); i++)
+		if (ext4_encoding_map[i].encoding_magic == encoding)
+			return ext4_encoding_map[i].default_flags;
+
+	return 0;
+}
+
+int e2p_str2encoding_flags(int encoding, char *param, __u16 *flags)
+{
+	char *f = strtok(param, "-");
+	const struct enc_flags *fl;
+	unsigned int i, neg = 0;
+
+	if (encoding != EXT4_ENC_UTF8_12_1)
+		return -EINVAL;
+	while (f) {
+		neg = 0;
+		if (!strncmp("no", f, 2)) {
+			neg = 1;
+			f += 2;
+		}
+
+		for (i = 0; i < ARRAY_SIZE(encoding_flags); i++) {
+			fl = &encoding_flags[i];
+			if (!strcmp(fl->param, f)) {
+				if (neg)
+					*flags &= ~fl->flag;
+				else
+					*flags |= fl->flag;
+
+				goto next_flag;
+			}
+		}
+		return -EINVAL;
+	next_flag:
+		f = strtok(NULL, "-");
+	}
+	return 0;
+}