[e2fsprogs,6/9] lib/ext2fs: Implement NLS support

diff --git a/lib/ext2fs/Makefile.in b/lib/ext2fs/Makefile.in
index 4a197cdf4e4a..a2f07403c9ae 100644
--- a/lib/ext2fs/Makefile.in
+++ b/lib/ext2fs/Makefile.in
@@ -20,6 +20,9 @@  COMPILE_ET=	_ET_DIR_OVERRIDE=$(srcdir)/../et ../et/compile_et
 @TEST_IO_CMT@TEST_IO_LIB_OBJS = test_io.o
 @IMAGER_CMT@E2IMAGE_LIB_OBJS = imager.o
 
+NLS_OBJS=nls_ascii.o
+NLS_SRCS=nls_ascii.c
+
 DEBUG_OBJS= debug_cmds.o extent_cmds.o tst_cmds.o debugfs.o util.o \
 	ncheck.o icheck.o ls.o lsdel.o dump.o set_fields.o logdump.o \
 	htree.o unused.o e2freefrag.o filefrag.o extent_inode.o zap.o \
@@ -130,7 +133,8 @@  OBJS= $(DEBUGFS_LIB_OBJS) $(RESIZE_LIB_OBJS) $(E2IMAGE_LIB_OBJS) \
 	unlink.o \
 	valid_blk.o \
 	version.o \
-	rbtree.o
+	rbtree.o \
+	$(NLS_OBJS)
 
 SRCS= ext2_err.c \
 	$(srcdir)/alloc.c \
@@ -222,7 +226,8 @@  SRCS= ext2_err.c \
 	$(srcdir)/write_bb_file.c \
 	$(srcdir)/rbtree.c \
 	$(srcdir)/tst_libext2fs.c \
-	$(DEBUG_SRCS)
+	$(DEBUG_SRCS) \
+	$(NLS_SRCS)
 
 HFILES= bitops.h ext2fs.h ext2_io.h ext2_fs.h ext2_ext_attr.h ext3_extents.h \
 	tdb.h qcow2.h hashmap.h
@@ -1412,3 +1417,4 @@  do_journal.o: $(top_srcdir)/debugfs/do_journal.c $(top_builddir)/lib/config.h \
  $(top_srcdir)/lib/support/quotaio_tree.h $(srcdir)/kernel-jbd.h \
  $(srcdir)/jfs_compat.h $(srcdir)/kernel-list.h \
  $(top_srcdir)/debugfs/journal.h $(srcdir)/../../e2fsck/jfs_user.h
+$(NLS_OBJS): $(srcdir)/nls.h
diff --git a/lib/ext2fs/nls.h b/lib/ext2fs/nls.h
new file mode 100644
index 000000000000..b7f6ebcd3b25
--- /dev/null
+++ b/lib/ext2fs/nls.h
@@ -0,0 +1,65 @@ 
+/*
+ * nls.h - Header for encoding support functions
+ *
+ * Copyright (C) 2017 Collabora Ltd.
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef EXT2FS_NLS_H
+#define EXT2FS_NLS_H
+
+#include <unistd.h>
+#include <string.h>
+#include <stdio.h>
+
+struct nls_table;
+
+#define ARRAY_SIZE(array)			\
+        (sizeof(array) / sizeof(array[0]))
+
+struct nls_ops {
+	int (*normalize)(const struct nls_table *charset,
+			 const unsigned char *str, size_t len,
+			 unsigned char *dest, size_t dlen);
+
+	int (*casefold)(const struct nls_table *charset,
+			const unsigned char *str, size_t len,
+			unsigned char *dest, size_t dlen);
+};
+
+struct nls_table {
+	char *name;
+	const struct nls_ops *ops;
+};
+
+extern const struct nls_table nls_ascii;
+
+static const struct nls_table *encoding_list[] = {
+	&nls_ascii
+};
+
+static const struct nls_table *nls_load_table(const char *name)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(encoding_list); i++) {
+		if (strcmp(encoding_list[i]->name, name) == 0)
+			return encoding_list[i];
+	}
+	return NULL;
+}
+
+#endif
diff --git a/lib/ext2fs/nls_ascii.c b/lib/ext2fs/nls_ascii.c
new file mode 100644
index 000000000000..22e819849f3a
--- /dev/null
+++ b/lib/ext2fs/nls_ascii.c
@@ -0,0 +1,48 @@ 
+#include "nls.h"
+#include <string.h>
+
+static unsigned char charset_tolower(const struct nls_table *table,
+				     unsigned int c)
+{
+	if (c >= 'A' && c <= 'Z')
+		return (c | 0x20);
+	return c;
+}
+
+static unsigned char charset_toupper(const struct nls_table *table,
+				     unsigned int c)
+{
+	if (c >= 'a' && c <= 'z')
+		return (c & ~0x20);
+	return c;
+}
+
+static int ascii_casefold(const struct nls_table *table,
+			  const unsigned char *str, size_t len,
+			  unsigned char *dest, size_t dlen)
+{
+	unsigned i;
+
+	for (i = 0; i < len; i++)
+		dest[i] = charset_toupper(table, str[i]);
+
+	return len;
+}
+
+static int ascii_normalize(const struct nls_table *table,
+			   const unsigned char *str, size_t len,
+			   unsigned char *dest, size_t dlen)
+{
+	memcpy(dest, str, len);
+	return len;
+}
+
+const static struct nls_ops ascii_ops = {
+	.casefold = ascii_casefold,
+	.normalize = ascii_normalize,
+};
+
+const struct nls_table nls_ascii = {
+	.name = "ascii",
+	.ops = &ascii_ops,
+};