1 files changed, 181 insertions, 17 deletions

diff --git a/fs/cifs/cifs_unicode.c b/fs/cifs/cifs_unicode.c
index 7d75272a6b3f..60e3c4253de0 100644
--- a/fs/cifs/cifs_unicode.c
+++ b/fs/cifs/cifs_unicode.c
@@ -1,7 +1,7 @@
 /*
  *   fs/cifs/cifs_unicode.c
  *
- *   Copyright (c) International Business Machines  Corp., 2000,2005
+ *   Copyright (c) International Business Machines  Corp., 2000,2009
  *   Modified by Steve French (sfrench@us.ibm.com)
  *
  *   This program is free software;  you can redistribute it and/or modify
@@ -26,31 +26,157 @@
 #include "cifs_debug.h"
 
 /*
- * NAME:        cifs_strfromUCS()
- *
- * FUNCTION:    Convert little-endian unicode string to character string
+ * cifs_ucs2_bytes - how long will a string be after conversion?
+ * @ucs - pointer to input string
+ * @maxbytes - don't go past this many bytes of input string
+ * @codepage - destination codepage
  *
+ * Walk a ucs2le 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.
  */
 int
-cifs_strfromUCS_le(char *to, const __le16 *from,
-                   int len, const struct nls_table *codepage)
+cifs_ucs2_bytes(const __le16 *from, int maxbytes,
+                const struct nls_table *codepage)
 {
         int i;
-        int outlen = 0;
+        int charlen, outlen = 0;
+        int maxwords = maxbytes / 2;
+        char tmp[NLS_MAX_CHARSET_SIZE];
 
-        for (i = 0; (i < len) && from[i]; i++) {
-                int charlen;
-                /* 2.4.0 kernel or greater */
-                charlen =
-                    codepage->uni2char(le16_to_cpu(from[i]), &to[outlen],
-                                       NLS_MAX_CHARSET_SIZE);
-                if (charlen > 0) {
+        for (i = 0; from[i] && i < maxwords; i++) {
+                charlen = codepage->uni2char(le16_to_cpu(from[i]), tmp,
+                                             NLS_MAX_CHARSET_SIZE);
+                if (charlen > 0)
                         outlen += charlen;
-                } else {
-                        to[outlen++] = '?';
+                else
+                        outlen++;
+        }
+
+        return outlen;
+}
+
+/*
+ * cifs_mapchar - convert a little-endian char to proper char in codepage
+ * @target - where converted character should be copied
+ * @src_char - 2 byte little-endian source character
+ * @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).
+ */
+static int
+cifs_mapchar(char *target, const __le16 src_char, const struct nls_table *cp,
+             bool mapchar)
+{
+        int len = 1;
+
+        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 (le16_to_cpu(src_char)) {
+        case UNI_COLON:
+                *target = ':';
+                break;
+        case UNI_ASTERIK:
+                *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(le16_to_cpu(src_char), target,
+                           NLS_MAX_CHARSET_SIZE);
+        if (len <= 0) {
+                *target = '?';
+                len = 1;
+        }
+        goto out;
+}
+
+/*
+ * cifs_from_ucs2 - 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 ucs2le 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 UCS-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.
+ */
+int
+cifs_from_ucs2(char *to, const __le16 *from, int tolen, int fromlen,
+                 const struct nls_table *codepage, bool mapchar)
+{
+        int i, charlen, safelen;
+        int outlen = 0;
+        int nullsize = nls_nullsize(codepage);
+        int fromwords = fromlen / 2;
+        char tmp[NLS_MAX_CHARSET_SIZE];
+
+        /*
+         * 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 && from[i]; i++) {
+                /*
+                 * check to see if converting this character might make the
+                 * conversion bleed into the null terminator
+                 */
+                if (outlen >= safelen) {
+                        charlen = cifs_mapchar(tmp, from[i], codepage, mapchar);
+                        if ((outlen + charlen) > (tolen - nullsize))
+                                break;
                 }
+
+                /* put converted char into 'to' buffer */
+                charlen = cifs_mapchar(&to[outlen], from[i], codepage, mapchar);
+                outlen += charlen;
         }
-        to[outlen] = 0;
+
+        /* properly null-terminate string */
+        for (i = 0; i < nullsize; i++)
+                to[outlen++] = 0;
+
         return outlen;
 }
 
@@ -88,3 +214,41 @@ cifs_strtoUCS(__le16 *to, const char *from, int len,
         return i;
 }
 
+/*
+ * cifs_strndup_from_ucs - 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.
+ */
+char *
+cifs_strndup_from_ucs(const char *src, const int maxlen, const bool is_unicode,
+             const struct nls_table *codepage)
+{
+        int len;
+        char *dst;
+
+        if (is_unicode) {
+                len = cifs_ucs2_bytes((__le16 *) src, maxlen, codepage);
+                len += nls_nullsize(codepage);
+                dst = kmalloc(len, GFP_KERNEL);
+                if (!dst)
+                        return NULL;
+                cifs_from_ucs2(dst, (__le16 *) src, len, maxlen, codepage,
+                               false);
+        } else {
+                len = strnlen(src, maxlen);
+                len++;
+                dst = kmalloc(len, GFP_KERNEL);
+                if (!dst)
+                        return NULL;
+                strlcpy(dst, src, len);
+        }
+
+        return dst;
+}
+