firmware/br-ext-chip-goke/board/gk7205v200/kernel/patches/00_fs-yaffs2-yaffs_nameval.c.patch

--- linux-4.9.37/fs/yaffs2/yaffs_nameval.c	1970-01-01 03:00:00.000000000 +0300
+++ linux-4.9.y/fs/yaffs2/yaffs_nameval.c	2021-06-07 13:01:34.000000000 +0300
@@ -0,0 +1,230 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2011 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This simple implementation of a name-value store assumes a small number of
+* values and fits into a small finite buffer.
+ *
+ * Each attribute is stored as a record:
+ *  sizeof(size) bytes   record size.
+ *  strnlen+1 bytes name null terminated.
+ *  nbytes    value.
+ *  ----------
+ *  total size  stored in record size
+ *
+ * This code has not been tested with unicode yet.
+ */
+
+#include "yaffs_nameval.h"
+#include "yaffs_guts.h"
+#include "yportenv.h"
+#include "yaffs_endian.h"
+
+static int nval_find(struct yaffs_dev *dev,
+		     const char *xb, int xb_size, const YCHAR *name,
+		     int *exist_size)
+{
+	int pos = 0;
+	s32 size;
+
+	memcpy(&size, xb, sizeof(size));
+	yaffs_do_endian_s32(dev, &size);
+
+	while (size > 0 && (size < xb_size) && (pos + size < xb_size)) {
+		if (!strncmp((YCHAR *) (xb + pos + sizeof(size)),
+				name, size)) {
+			if (exist_size)
+				*exist_size = size;
+			return pos;
+		}
+		pos += size;
+		if (pos < (int)(xb_size - sizeof(size))) {
+			memcpy(&size, xb + pos, sizeof(size));
+			yaffs_do_endian_s32(dev, &size);
+
+		} else
+			size = 0;
+	}
+	if (exist_size)
+		*exist_size = 0;
+	return -ENODATA;
+}
+
+static int nval_used(struct yaffs_dev *dev, const char *xb, int xb_size)
+{
+	int pos = 0;
+	s32 size;
+
+	memcpy(&size, xb + pos, sizeof(size));
+	yaffs_do_endian_s32(dev, &size);
+
+	while (size > 0 && (size < xb_size) && (pos + size < xb_size)) {
+		pos += size;
+		if (pos < (int)(xb_size - sizeof(size))) {
+			memcpy(&size, xb + pos, sizeof(size));
+			yaffs_do_endian_s32(dev, &size);
+		} else
+			size = 0;
+	}
+	return pos;
+}
+
+int nval_del(struct yaffs_dev *dev, char *xb, int xb_size, const YCHAR *name)
+{
+	int pos = nval_find(dev, xb, xb_size, name, NULL);
+	s32 size;
+
+	if (pos < 0 || pos >= xb_size)
+		return -ENODATA;
+
+	/* Find size, shift rest over this record,
+	 * then zero out the rest of buffer */
+	memcpy(&size, xb + pos, sizeof(size));
+	yaffs_do_endian_s32(dev, &size);
+
+	memcpy(xb + pos, xb + pos + size, xb_size - (pos + size));
+	memset(xb + (xb_size - size), 0, size);
+	return 0;
+}
+
+int nval_set(struct yaffs_dev *dev,
+	     char *xb, int xb_size, const YCHAR *name, const char *buf,
+	     int bsize, int flags)
+{
+	int pos;
+	int namelen = strnlen(name, xb_size);
+	int size_exist = 0;
+	int space;
+	int start;
+	s32 reclen;
+	s32 reclen_endianised;
+
+	pos = nval_find(dev, xb, xb_size, name, &size_exist);
+
+	if (flags & XATTR_CREATE && pos >= 0)
+		return -EEXIST;
+	if (flags & XATTR_REPLACE && pos < 0)
+		return -ENODATA;
+
+	start = nval_used(dev, xb, xb_size);
+	space = xb_size - start + size_exist;
+
+	reclen = (sizeof(reclen) + namelen + 1 + bsize);
+
+	if (reclen > space)
+		return -ENOSPC;
+
+	if (pos >= 0) {
+		/* Exists, so delete it. */
+		nval_del(dev, xb, xb_size, name);
+		start = nval_used(dev, xb, xb_size);
+	}
+
+	pos = start;
+
+	reclen_endianised = reclen;
+	yaffs_do_endian_s32(dev, &reclen_endianised);
+	memcpy(xb + pos, &reclen_endianised, sizeof(reclen_endianised));
+	pos += sizeof(reclen_endianised);
+	strncpy((YCHAR *) (xb + pos), name, reclen);
+	pos += (namelen + 1);
+	memcpy(xb + pos, buf, bsize);
+	return 0;
+}
+
+int nval_get(struct yaffs_dev *dev,
+	     const char *xb, int xb_size, const YCHAR * name, char *buf,
+	     int bsize)
+{
+	int pos = nval_find(dev, xb, xb_size, name, NULL);
+	s32 size;
+
+	if (pos >= 0 && pos < xb_size) {
+
+		memcpy(&size, xb + pos, sizeof(size));
+		yaffs_do_endian_s32(dev, &size);
+		pos += sizeof(size);	/* advance past record length */
+		size -= sizeof(size);
+
+		/* Advance over name string */
+		while (xb[pos] && size > 0 && pos < xb_size) {
+			pos++;
+			size--;
+		}
+		/*Advance over NUL */
+		pos++;
+		size--;
+
+		/* If bsize is zero then this is a size query.
+		 * Return the size, but don't copy.
+		 */
+		if (!bsize)
+			return size;
+
+		if (size <= bsize) {
+			memcpy(buf, xb + pos, size);
+			return size;
+		}
+	}
+	if (pos >= 0)
+		return -ERANGE;
+
+	return -ENODATA;
+}
+
+int nval_list(struct yaffs_dev *dev, const char *xb, int xb_size, char *buf, int bsize)
+{
+	int pos = 0;
+	s32 size;
+	int name_len;
+	int ncopied = 0;
+	int filled = 0;
+
+	memcpy(&size, xb + pos, sizeof(size));
+	yaffs_do_endian_s32(dev, &size);
+
+	while (size > (int)(sizeof(size)) &&
+		size <= xb_size &&
+		(pos + size) < xb_size &&
+		!filled) {
+		pos += sizeof(size);
+		size -= sizeof(size);
+		name_len = strnlen((YCHAR *) (xb + pos), size);
+		if (ncopied + name_len + 1 < bsize) {
+			memcpy(buf, xb + pos, name_len * sizeof(YCHAR));
+			buf += name_len;
+			*buf = '\0';
+			buf++;
+			if (sizeof(YCHAR) > 1) {
+				*buf = '\0';
+				buf++;
+			}
+			ncopied += (name_len + 1);
+		} else {
+			filled = 1;
+		}
+		pos += size;
+		if (pos < (int)(xb_size - sizeof(size))) {
+			memcpy(&size, xb + pos, sizeof(size));
+			yaffs_do_endian_s32(dev, &size);
+		}
+		else
+			size = 0;
+	}
+	return ncopied;
+}
+
+int nval_hasvalues(struct yaffs_dev *dev, const char *xb, int xb_size)
+{
+	return nval_used(dev, xb, xb_size) > 0;
+}