[PATCH] s3:loadparm: Ensure to truncate FS Volume Label at multibyte boundary

[Shyam Rathi]

Thanks for the changes Jeremy. Looks Good To Me!


Regards,
-Shyam

From: Jeremy Allison <jra at samba.org>
Reply-To: Jeremy Allison <jra at samba.org>
Date: Wednesday, May 15, 2019 at 1:58 PM
To: Shyam Rathi <shyam.rathi at nutanix.com>
Cc: "samba-technical at lists.samba.org" <samba-technical at lists.samba.org>, "slow at samba.org" <slow at samba.org>, "asn at samba.org" <asn at samba.org>, "ddiss at samba.org" <ddiss at samba.org>
Subject: Re: [PATCH] s3:loadparm: Ensure to truncate FS Volume Label at multibyte boundary

On Tue, May 14, 2019 at 06:26:07PM +0000, Shyam Rathi via samba-technical wrote:
https://urldefense.proofpoint.com/v2/url?u=https-3A__bugzilla.samba.org_show-5Fbug.cgi-3Fid-3D13947&d=DwIDaQ&c=s883GpUCOChKOHiocYtGcg&r=01xcNiYQJzRsQpoTRuxjGKbHz89cfrrcU79qoxdog2k&m=SeK7f4yx4Rk3qX9KnsgVyTLpIjHhMyUW70jMfKa3bHs&s=MkcYRjKdSRhoAr0ulnCqFTOUb7F49861TgBZkNodt30&e=
To reproduce, create a share with a name where 32nd byte is not the first byte of a mutlibyte character. Using CJK characters (3 bytes each) is a possible approach. For example, creating a share with name 에이에프에스삼점오생성 and trying to open a txt file in Notepad gives the following error:
   Invalid character. For multibyte character sets, only the leading byte is
   included without the trailing byte. For Unicode character sets, include
   the characters 0xFFFF and 0xFFFE.
Looking at wireshark capture, the following is seen as source of this issue:
   GetInfo Request FS_INFO/FileFsVolumeInformation File: Rathi9\???????????
   GetInfo Response, Error: STATUS_ILLEGAL_CHARACTER
Proposed solution is to truncate the label name at the end of a multibyte character before the 32nd byte.
Please review and suggest changes, improvements and other approaches.
Regards,
-Shyamsunder Rathi (mailto:shyam.rathi at nutanix.com)

A few slight changes to make things clearer (to me at least :-).
Changes attached and bug ID added to the commit message. Let me
know if you're OK with it.

RB+. Can I get a second Team reviewer ?

Jeremy.