[PATCH v2] Convert properly UTF-8 to UTF-16

[Frediano Ziglio]

On Tue, 2012-08-07 at 06:47 -0400, Jeff Layton wrote:
> On Tue, 7 Aug 2012 10:33:03 +0100
> Frediano Ziglio <frediano.ziglio at citrix.com> wrote:
> 
> > 
> > wchar_t is currently 16bit so converting a utf8 encoded characters
not
> > in plane 0 (>= 0x10000) to wchar_t (that is calling char2uni) lead
to a
> > -EINVAL return. This patch detect utf8 in cifs_strtoUTF16 and add
special
> > code calling utf8s_to_utf16s.
> > 
> > Signed-off-by: Frediano Ziglio <frediano.ziglio at citrix.com>
> > ---
> >  fs/cifs/cifs_unicode.c |   22 ++++++++++++++++++++++
> >  1 files changed, 22 insertions(+), 0 deletions(-)
> > 
> > diff --git a/fs/cifs/cifs_unicode.c b/fs/cifs/cifs_unicode.c
> > index 7dab9c0..1166b95 100644
> > --- a/fs/cifs/cifs_unicode.c
> > +++ b/fs/cifs/cifs_unicode.c
> > @@ -203,6 +203,27 @@ cifs_strtoUTF16(__le16 *to, const char *from,
int len,
> >     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 && *from; i++, from += charlen, len -= charlen)
{
> >             charlen = codepage->char2uni(from, len, &wchar_to);
> >             if (charlen < 1) {
> > @@ -215,6 +236,7 @@ cifs_strtoUTF16(__le16 *to, const char *from,
int len,
> >             put_unaligned_le16(wchar_to, &to[i]);
> >     }
> >  
> > +success:
> >     put_unaligned_le16(0, &to[i]);
> >     return i;
> >  }
> 
> Looks reasonable...
> 
> Acked-by: Jeff Layton <jlayton at redhat.com>

Steve, could you consider my patch for inclusion into Linux?

Thanks,
  Frediano