Re: [PATCH] connect.c: add a way for git-daemon to pass an error back to client

From: Andreas Ericsson <ae@op5.se>
Date: Nov 1, 2008, 11:30 UTC
Message-ID: <490C3DE2.3010808@op5.se>
In-Reply-To: <alpine.LFD.2.00.0810312218300.13034@xanadu.home>

Nicolas Pitre wrote:

Show 24 quoted lines

> On Sat, 1 Nov 2008, Johannes Schindelin wrote:
> 
>> Hi,
>>
>> On Fri, 31 Oct 2008, Tom Preston-Werner wrote:
>>
>>> The current behavior of git-daemon is to simply close the connection on
>>> any error condition. This leaves the client without any information as
>>> to the cause of the failed fetch/push/etc.
>>>
>>> This patch allows get_remote_heads to accept a line prefixed with "ERR"
>>> that it can display to the user in an informative fashion. Once clients
>>> can understand this ERR line, git-daemon can be made to properly report
>>> "repository not found", "permission denied", or other errors.
>>>
>>> Example
>>>
>>> S: ERR No matching repository.
>>> C: fatal: remote error: No matching repository.
>> Makes sense to me.
> 
> Note that this behavior of not returning any reason for failure was 
> argued to be a security feature in the past, by Linus I think.
>

By me actually. I wrote the patch for it. Showing "no matching repository" means git-daemon can be used to disclose information about the remote server's filesystem layout. While I understand that it's sometimes a useful feature, please don't ever enable it by default.

That said, I like this patch, as it only works client-side and just enables others to write code that let's the daemon (if configured to do so) ship a more informative error message.

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231