On 07/30/2013 05:10 AM, Scott Lovenberg wrote: > On Mon, Jul 29, 2013 at 4:17 PM, Jeff Layton <jlayton@xxxxxxxxxx> wrote: >>>>> Still, how can we have a FQDN that's 256 characters long when the host >>>>> name length can be 1024 characters long? >>>>> >>>> >>>> Excuse me, I am not quite familiar about cifs, so can not provide >>>> additional more information (I found it only by reading code). >>>> >>>> But I feel, it really need additional discussion and check by the >>>> related experts (related members who are familiar with cifs). >>>> >>>> Welcome any members' suggestions and completions. >>>> >>>> Thanks. >>> >>> Come on guys, enough already. As per here: >>> https://en.wikipedia.org/wiki/Domain_Name_System >>> >>> and a comment above the max len of the fully qualified domain name (FQDN) is >>> 63 octets per label and 255 bytes per FQDN. This maximum includes 254 >>> bytes for the FQDN and one byte for the ending dot. >>> >> >> Ok, I think I knew that at one point and paged it out. It does make one >> wonder why NI_MAXHOST is so big though -- is that for some >> internationalization scheme? >> >> -- >> Jeff Layton <jlayton@xxxxxxxxxx> > > I guess it works if you're storing as UTF-32 or wchar_t at 4 bytes per > character. 256 characters * 4 bytes/char + 1 byte for NULL. Microsoft > seems to use the same value for NI_MAXHOST ref: > http://msdn.microsoft.com/en-us/library/windows/desktop/ms738532(v=vs.85).aspx > . > As far as I know, the kernel implementation wants to use 255 + 1 as character count, not bytes count for FQDN (256 bytes for 8-bit, 512 bytes for 16-bit, ...), it can be translated into uni-code or other format within 255 + 1 character count. May it be useful for our discussion ? (BTW: if kernel really wants to do, I also suggest to check the kernel implementation for it whether correct or not). Thanks. -- Chen Gang -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
