Re: [PATCH 1/3] cifs: Introduce helper to compute length of nls string in bytes

On Fri, Apr 24, 2009 at 11:57 AM, Shirish Pargaonkar
<[email protected]> wrote:
> On Thu, Apr 23, 2009 at 12:56 AM, Jeff Layton <[email protected]> wrote:
>> On Thu, 23 Apr 2009 02:49:21 +0200
>> Günter Kukkukk <[email protected]> wrote:
>>
>>> just some further notes.
>>> With "it's heavily used" i didn't mean the number of callers using this
>>> function (only 1 in readdir.c) - i meant "the number of times" cifs_convertUCSpath()
>>> is called in daily usage.... (readdir results)
>>>
>>> The current focus was mostly on cifs_strfromUCS_le() - but the _same_ applies
>>> to cifs_convertUCSpath()!
>>>
>>> See the following code snippet:
>>>
>>> readdir.c --> static int cifs_get_name_from_search_buf()
>>> ....
>>>
>>>       if (unicode) {
>>>               /* BB fixme - test with long names */
>>>               /* Note converted filename can be longer than in unicode */
>>>               if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
>>>                       pqst->len = cifs_convertUCSpath((char *)pqst->name,
>>>                                       (__le16 *)filename, len/2, nlt);
>>>               else
>>>                       pqst->len = cifs_strfromUCS_le((char *)pqst->name,
>>>                                       (__le16 *)filename, len/2, nlt);
>>>
>>> ....
>>
>> I see what you mean. Good catch. That function also has broken buffer
>> length checking logic too.
>>
>> This patch is only compile-tested, but it should fix those problems. In
>> the long run, we probably need to make all of these functions take an
>> argument with the length of the destination buffer.
>>
>> Let's plan that overhaul after Suresh's latest set goes in though.
>>
>> --
>> Jeff Layton <[email protected]>
>>
>> _______________________________________________
>> linux-cifs-client mailing list
>> [email protected]
>> https://lists.samba.org/mailman/listinfo/linux-cifs-client
>>
>>
>
> A general question, the functions such as cifs_strtoUCS call uni2char
> which assumes UTF-8 translation format.
> If one of the characaters being encoded happens to be 6 bytes long,
> will a SMB/CIFS server be able
> to handle that i.e. if it is expecting a UCS-2LE encoding, thus a two
> byte encoded value, (how) would it handle
> 6 byte encoded value!
>

Sorry, I meant to say
 'char2uni which assumes UTF-8 translation format'
and not
 'uni2char which assumes UTF-8 translation format'