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-rw-r--r--fs/smb/server/unicode.c455
1 files changed, 455 insertions, 0 deletions
diff --git a/fs/smb/server/unicode.c b/fs/smb/server/unicode.c
new file mode 100644
index 000000000..33fc6d45c
--- /dev/null
+++ b/fs/smb/server/unicode.c
@@ -0,0 +1,455 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Some of the source code in this file came from fs/cifs/cifs_unicode.c
+ *
+ * Copyright (c) International Business Machines Corp., 2000,2009
+ * Modified by Steve French (sfrench@us.ibm.com)
+ * Modified by Namjae Jeon (linkinjeon@kernel.org)
+ */
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <asm/unaligned.h>
+#include "glob.h"
+#include "unicode.h"
+#include "uniupr.h"
+#include "smb_common.h"
+
+/*
+ * cifs_mapchar() - convert a host-endian char to proper char in codepage
+ * @target: where converted character should be copied
+ * @from: host-endian source string
+ * @cp: codepage to which character should be converted
+ * @mapchar: should character be mapped according to mapchars mount option?
+ *
+ * This function handles the conversion of a single character. It is the
+ * responsibility of the caller to ensure that the target buffer is large
+ * enough to hold the result of the conversion (at least NLS_MAX_CHARSET_SIZE).
+ *
+ * Return: string length after conversion
+ */
+static int
+cifs_mapchar(char *target, const __u16 *from, const struct nls_table *cp,
+ bool mapchar)
+{
+ int len = 1;
+ __u16 src_char;
+
+ src_char = *from;
+
+ if (!mapchar)
+ goto cp_convert;
+
+ /*
+ * BB: Cannot handle remapping UNI_SLASH until all the calls to
+ * build_path_from_dentry are modified, as they use slash as
+ * separator.
+ */
+ switch (src_char) {
+ case UNI_COLON:
+ *target = ':';
+ break;
+ case UNI_ASTERISK:
+ *target = '*';
+ break;
+ case UNI_QUESTION:
+ *target = '?';
+ break;
+ case UNI_PIPE:
+ *target = '|';
+ break;
+ case UNI_GRTRTHAN:
+ *target = '>';
+ break;
+ case UNI_LESSTHAN:
+ *target = '<';
+ break;
+ default:
+ goto cp_convert;
+ }
+
+out:
+ return len;
+
+cp_convert:
+ len = cp->uni2char(src_char, target, NLS_MAX_CHARSET_SIZE);
+ if (len <= 0)
+ goto surrogate_pair;
+
+ goto out;
+
+surrogate_pair:
+ /* convert SURROGATE_PAIR and IVS */
+ if (strcmp(cp->charset, "utf8"))
+ goto unknown;
+ len = utf16s_to_utf8s(from, 3, UTF16_LITTLE_ENDIAN, target, 6);
+ if (len <= 0)
+ goto unknown;
+ return len;
+
+unknown:
+ *target = '?';
+ len = 1;
+ goto out;
+}
+
+/*
+ * smb_utf16_bytes() - compute converted string length
+ * @from: pointer to input string
+ * @maxbytes: input string length
+ * @codepage: destination codepage
+ *
+ * Walk a utf16le string and return the number of bytes that the string will
+ * be after being converted to the given charset, not including any null
+ * termination required. Don't walk past maxbytes in the source buffer.
+ *
+ * Return: string length after conversion
+ */
+static int smb_utf16_bytes(const __le16 *from, int maxbytes,
+ const struct nls_table *codepage)
+{
+ int i, j;
+ int charlen, outlen = 0;
+ int maxwords = maxbytes / 2;
+ char tmp[NLS_MAX_CHARSET_SIZE];
+ __u16 ftmp[3];
+
+ for (i = 0; i < maxwords; i++) {
+ ftmp[0] = get_unaligned_le16(&from[i]);
+ if (ftmp[0] == 0)
+ break;
+ for (j = 1; j <= 2; j++) {
+ if (i + j < maxwords)
+ ftmp[j] = get_unaligned_le16(&from[i + j]);
+ else
+ ftmp[j] = 0;
+ }
+
+ charlen = cifs_mapchar(tmp, ftmp, codepage, 0);
+ if (charlen > 0)
+ outlen += charlen;
+ else
+ outlen++;
+ }
+
+ return outlen;
+}
+
+/*
+ * smb_from_utf16() - convert utf16le string to local charset
+ * @to: destination buffer
+ * @from: source buffer
+ * @tolen: destination buffer size (in bytes)
+ * @fromlen: source buffer size (in bytes)
+ * @codepage: codepage to which characters should be converted
+ * @mapchar: should characters be remapped according to the mapchars option?
+ *
+ * Convert a little-endian utf16le string (as sent by the server) to a string
+ * in the provided codepage. The tolen and fromlen parameters are to ensure
+ * that the code doesn't walk off of the end of the buffer (which is always
+ * a danger if the alignment of the source buffer is off). The destination
+ * string is always properly null terminated and fits in the destination
+ * buffer. Returns the length of the destination string in bytes (including
+ * null terminator).
+ *
+ * Note that some windows versions actually send multiword UTF-16 characters
+ * instead of straight UTF16-2. The linux nls routines however aren't able to
+ * deal with those characters properly. In the event that we get some of
+ * those characters, they won't be translated properly.
+ *
+ * Return: string length after conversion
+ */
+static int smb_from_utf16(char *to, const __le16 *from, int tolen, int fromlen,
+ const struct nls_table *codepage, bool mapchar)
+{
+ int i, j, charlen, safelen;
+ int outlen = 0;
+ int nullsize = nls_nullsize(codepage);
+ int fromwords = fromlen / 2;
+ char tmp[NLS_MAX_CHARSET_SIZE];
+ __u16 ftmp[3]; /* ftmp[3] = 3array x 2bytes = 6bytes UTF-16 */
+
+ /*
+ * because the chars can be of varying widths, we need to take care
+ * not to overflow the destination buffer when we get close to the
+ * end of it. Until we get to this offset, we don't need to check
+ * for overflow however.
+ */
+ safelen = tolen - (NLS_MAX_CHARSET_SIZE + nullsize);
+
+ for (i = 0; i < fromwords; i++) {
+ ftmp[0] = get_unaligned_le16(&from[i]);
+ if (ftmp[0] == 0)
+ break;
+ for (j = 1; j <= 2; j++) {
+ if (i + j < fromwords)
+ ftmp[j] = get_unaligned_le16(&from[i + j]);
+ else
+ ftmp[j] = 0;
+ }
+
+ /*
+ * check to see if converting this character might make the
+ * conversion bleed into the null terminator
+ */
+ if (outlen >= safelen) {
+ charlen = cifs_mapchar(tmp, ftmp, codepage, mapchar);
+ if ((outlen + charlen) > (tolen - nullsize))
+ break;
+ }
+
+ /* put converted char into 'to' buffer */
+ charlen = cifs_mapchar(&to[outlen], ftmp, codepage, mapchar);
+ outlen += charlen;
+
+ /*
+ * charlen (=bytes of UTF-8 for 1 character)
+ * 4bytes UTF-8(surrogate pair) is charlen=4
+ * (4bytes UTF-16 code)
+ * 7-8bytes UTF-8(IVS) is charlen=3+4 or 4+4
+ * (2 UTF-8 pairs divided to 2 UTF-16 pairs)
+ */
+ if (charlen == 4)
+ i++;
+ else if (charlen >= 5)
+ /* 5-6bytes UTF-8 */
+ i += 2;
+ }
+
+ /* properly null-terminate string */
+ for (i = 0; i < nullsize; i++)
+ to[outlen++] = 0;
+
+ return outlen;
+}
+
+/*
+ * smb_strtoUTF16() - Convert character string to unicode string
+ * @to: destination buffer
+ * @from: source buffer
+ * @len: destination buffer size (in bytes)
+ * @codepage: codepage to which characters should be converted
+ *
+ * Return: string length after conversion
+ */
+int smb_strtoUTF16(__le16 *to, const char *from, int len,
+ const struct nls_table *codepage)
+{
+ int charlen;
+ int i;
+ wchar_t wchar_to; /* needed to quiet sparse */
+
+ /* special case for utf8 to handle no plane0 chars */
+ if (!strcmp(codepage->charset, "utf8")) {
+ /*
+ * convert utf8 -> utf16, we assume we have enough space
+ * as caller should have assumed conversion does not overflow
+ * in destination len is length in wchar_t units (16bits)
+ */
+ i = utf8s_to_utf16s(from, len, UTF16_LITTLE_ENDIAN,
+ (wchar_t *)to, len);
+
+ /* if success terminate and exit */
+ if (i >= 0)
+ goto success;
+ /*
+ * if fails fall back to UCS encoding as this
+ * function should not return negative values
+ * currently can fail only if source contains
+ * invalid encoded characters
+ */
+ }
+
+ for (i = 0; len > 0 && *from; i++, from += charlen, len -= charlen) {
+ charlen = codepage->char2uni(from, len, &wchar_to);
+ if (charlen < 1) {
+ /* A question mark */
+ wchar_to = 0x003f;
+ charlen = 1;
+ }
+ put_unaligned_le16(wchar_to, &to[i]);
+ }
+
+success:
+ put_unaligned_le16(0, &to[i]);
+ return i;
+}
+
+/*
+ * smb_strndup_from_utf16() - copy a string from wire format to the local
+ * codepage
+ * @src: source string
+ * @maxlen: don't walk past this many bytes in the source string
+ * @is_unicode: is this a unicode string?
+ * @codepage: destination codepage
+ *
+ * Take a string given by the server, convert it to the local codepage and
+ * put it in a new buffer. Returns a pointer to the new string or NULL on
+ * error.
+ *
+ * Return: destination string buffer or error ptr
+ */
+char *smb_strndup_from_utf16(const char *src, const int maxlen,
+ const bool is_unicode,
+ const struct nls_table *codepage)
+{
+ int len, ret;
+ char *dst;
+
+ if (is_unicode) {
+ len = smb_utf16_bytes((__le16 *)src, maxlen, codepage);
+ len += nls_nullsize(codepage);
+ dst = kmalloc(len, GFP_KERNEL);
+ if (!dst)
+ return ERR_PTR(-ENOMEM);
+ ret = smb_from_utf16(dst, (__le16 *)src, len, maxlen, codepage,
+ false);
+ if (ret < 0) {
+ kfree(dst);
+ return ERR_PTR(-EINVAL);
+ }
+ } else {
+ len = strnlen(src, maxlen);
+ len++;
+ dst = kmalloc(len, GFP_KERNEL);
+ if (!dst)
+ return ERR_PTR(-ENOMEM);
+ strscpy(dst, src, len);
+ }
+
+ return dst;
+}
+
+/*
+ * Convert 16 bit Unicode pathname to wire format from string in current code
+ * page. Conversion may involve remapping up the six characters that are
+ * only legal in POSIX-like OS (if they are present in the string). Path
+ * names are little endian 16 bit Unicode on the wire
+ */
+/*
+ * smbConvertToUTF16() - convert string from local charset to utf16
+ * @target: destination buffer
+ * @source: source buffer
+ * @srclen: source buffer size (in bytes)
+ * @cp: codepage to which characters should be converted
+ * @mapchar: should characters be remapped according to the mapchars option?
+ *
+ * Convert 16 bit Unicode pathname to wire format from string in current code
+ * page. Conversion may involve remapping up the six characters that are
+ * only legal in POSIX-like OS (if they are present in the string). Path
+ * names are little endian 16 bit Unicode on the wire
+ *
+ * Return: char length after conversion
+ */
+int smbConvertToUTF16(__le16 *target, const char *source, int srclen,
+ const struct nls_table *cp, int mapchars)
+{
+ int i, j, charlen;
+ char src_char;
+ __le16 dst_char;
+ wchar_t tmp;
+ wchar_t wchar_to[6]; /* UTF-16 */
+ int ret;
+ unicode_t u;
+
+ if (!mapchars)
+ return smb_strtoUTF16(target, source, srclen, cp);
+
+ for (i = 0, j = 0; i < srclen; j++) {
+ src_char = source[i];
+ charlen = 1;
+ switch (src_char) {
+ case 0:
+ put_unaligned(0, &target[j]);
+ return j;
+ case ':':
+ dst_char = cpu_to_le16(UNI_COLON);
+ break;
+ case '*':
+ dst_char = cpu_to_le16(UNI_ASTERISK);
+ break;
+ case '?':
+ dst_char = cpu_to_le16(UNI_QUESTION);
+ break;
+ case '<':
+ dst_char = cpu_to_le16(UNI_LESSTHAN);
+ break;
+ case '>':
+ dst_char = cpu_to_le16(UNI_GRTRTHAN);
+ break;
+ case '|':
+ dst_char = cpu_to_le16(UNI_PIPE);
+ break;
+ /*
+ * FIXME: We can not handle remapping backslash (UNI_SLASH)
+ * until all the calls to build_path_from_dentry are modified,
+ * as they use backslash as separator.
+ */
+ default:
+ charlen = cp->char2uni(source + i, srclen - i, &tmp);
+ dst_char = cpu_to_le16(tmp);
+
+ /*
+ * if no match, use question mark, which at least in
+ * some cases serves as wild card
+ */
+ if (charlen > 0)
+ goto ctoUTF16;
+
+ /* convert SURROGATE_PAIR */
+ if (strcmp(cp->charset, "utf8"))
+ goto unknown;
+ if (*(source + i) & 0x80) {
+ charlen = utf8_to_utf32(source + i, 6, &u);
+ if (charlen < 0)
+ goto unknown;
+ } else
+ goto unknown;
+ ret = utf8s_to_utf16s(source + i, charlen,
+ UTF16_LITTLE_ENDIAN,
+ wchar_to, 6);
+ if (ret < 0)
+ goto unknown;
+
+ i += charlen;
+ dst_char = cpu_to_le16(*wchar_to);
+ if (charlen <= 3)
+ /* 1-3bytes UTF-8 to 2bytes UTF-16 */
+ put_unaligned(dst_char, &target[j]);
+ else if (charlen == 4) {
+ /*
+ * 4bytes UTF-8(surrogate pair) to 4bytes UTF-16
+ * 7-8bytes UTF-8(IVS) divided to 2 UTF-16
+ * (charlen=3+4 or 4+4)
+ */
+ put_unaligned(dst_char, &target[j]);
+ dst_char = cpu_to_le16(*(wchar_to + 1));
+ j++;
+ put_unaligned(dst_char, &target[j]);
+ } else if (charlen >= 5) {
+ /* 5-6bytes UTF-8 to 6bytes UTF-16 */
+ put_unaligned(dst_char, &target[j]);
+ dst_char = cpu_to_le16(*(wchar_to + 1));
+ j++;
+ put_unaligned(dst_char, &target[j]);
+ dst_char = cpu_to_le16(*(wchar_to + 2));
+ j++;
+ put_unaligned(dst_char, &target[j]);
+ }
+ continue;
+
+unknown:
+ dst_char = cpu_to_le16(0x003f);
+ charlen = 1;
+ }
+
+ctoUTF16:
+ /*
+ * character may take more than one byte in the source string,
+ * but will take exactly two bytes in the target string
+ */
+ i += charlen;
+ put_unaligned(dst_char, &target[j]);
+ }
+
+ return j;
+}
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