On Thu, 29 Dec 2011 19:01:24 +0400
Pavel Shilovsky <piastry@xxxxxxxxxxx> wrote:
> 2011/11/1 Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>:
> > On Fri, Oct 28, 2011 at 2:54 PM, Pavel Shilovsky <piastry@xxxxxxxxxxx> wrote:
> >> From: Steve French <sfrench@xxxxxxxxxx>
> >>
> >> Signed-off-by: Steve French <sfrench@xxxxxxxxxx>
> >> Signed-off-by: Pavel Shilovsky <piastry@xxxxxxxxxxx>
> >> ---
> >> fs/cifs/cifs_unicode.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++
> >> fs/cifs/cifs_unicode.h | 7 +++++
> >> 2 files changed, 68 insertions(+), 0 deletions(-)
> >>
> >> diff --git a/fs/cifs/cifs_unicode.c b/fs/cifs/cifs_unicode.c
> >> index 1b2e180..7f09423 100644
> >> --- a/fs/cifs/cifs_unicode.c
> >> +++ b/fs/cifs/cifs_unicode.c
> >> @@ -330,3 +330,64 @@ ctoUCS_out:
> >> return i;
> >> }
> >>
> >> +#ifdef CONFIG_CIFS_SMB2
> >> +/*
> >> + * smb2_local_to_ucs2_bytes - how long will a string be after conversion?
> >> + * @from - pointer to input string
> >> + * @maxbytes - don't go past this many bytes of input string
> >> + * @codepage - source codepage
> >> + *
> >> + * Walk a 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
> >> +smb2_local_to_ucs2_bytes(const char *from, int len,
> >> + const struct nls_table *codepage)
> >> +{
> >> + int charlen;
> >> + int i;
> >> + wchar_t wchar_to;
> >> +
> >> + if (from == NULL)
> >> + return 0;
^^^^^^^^
Are there really cases where you'll pass in a NULL pointer here?
> >> + for (i = 0; len && *from; i++, from += charlen, len -= charlen) {
> >> + charlen = codepage->char2uni(from, len, &wchar_to);
^^^^
This may result in an unaligned
access. You should use
put_unaligned to place this
in the string.
> >> + /* Failed conversion defaults to a question mark */
> >> + if (charlen < 1)
> >> + charlen = 1;
> >> + }
> >> + return 2 * i; /* UCS characters are two bytes */
> >> +}
> >> +
> >> +/*
> >> + * smb2_strndup_to_ucs - copy a string to wire format from the local codepage
> >> + * @src - source string
> >> + * @maxlen - don't walk past this many bytes in the source string
> >> + * @ucslen - the length of the allocated string in bytes (including null)
> >> + * @codepage - source codepage
> >> + *
> >> + * Take a string convert it from the local codepage to UCS2 and
> >> + * put it in a new buffer. Returns a pointer to the new string or NULL on
> >> + * error.
> >> + */
> >> +__le16 *
> >> +smb2_strndup_to_ucs(const char *src, const int maxlen, int *ucs_len,
> >> + const struct nls_table *codepage)
> >> +{
> >> + int len;
> >> + __le16 *dst;
> >> +
> >> + len = smb2_local_to_ucs2_bytes(src, maxlen, codepage);
> >> + len += 2; /* NULL */
> >> + dst = kmalloc(len, GFP_KERNEL);
> >> + if (!dst) {
> >> + *ucs_len = 0;
> >> + return NULL;
> >> + }
> >> + cifs_strtoUCS(dst, src, maxlen, codepage);
> >> + *ucs_len = len;
> >> + return dst;
> >> +}
> >> +#endif /* CONFIG_CIFS_SMB2 */
> >> diff --git a/fs/cifs/cifs_unicode.h b/fs/cifs/cifs_unicode.h
> >> index 6d02fd5..e00f677 100644
> >> --- a/fs/cifs/cifs_unicode.h
> >> +++ b/fs/cifs/cifs_unicode.h
> >> @@ -380,4 +380,11 @@ UniStrlwr(register wchar_t *upin)
> >>
> >> #endif
> >>
> >> +#ifdef CONFIG_CIFS_SMB2
> >> +extern int smb2_local_to_ucs2_bytes(const char *from, int len,
> >> + const struct nls_table *codepage);
> >> +extern __le16 *smb2_strndup_to_ucs(const char *src, const int maxlen,
> >> + int *ucs_len, const struct nls_table *cp);
> >> +#endif /* CONFIG_CIFS_SMB2 */
> >> +
> >> #endif /* _CIFS_UNICODE_H */
> >> --
> >> 1.7.1
> >>
> >> --
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> >>
> >
> > Should these functions be renamed to *utf16* instead of *ucs*
> > to reflect the unicode encoding used in cifs/smb2 protocol?
>
> Seems no problem to rename it.
>
> Jeff, Steve, thoughts? If no objections - I will rename *ucs* to *utf16*.
>
Yeah, now that I look over the NLS code, it does seem to be converting
to UTF16 and not to UCS2. You should probably rename the existing *ucs*
functions in cifs_unicode.c as well.
Also, we should probably settle on a prefix for these that makes sense.
These are only currently used by smb2 code, but they aren't truly
smb2-specific. I'd name them cifs_* myself, but maybe something more
neutral makes sense?
--
Jeff Layton <jlayton@xxxxxxxxxx>
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