Re: [Qemu-devel] [PATCH 2/3] pc-bios/s390-ccw/net: Add support for pxelinux-style config files

[Thomas Huth]

On 01.06.2018 22:19, Farhan Ali wrote:
> 
> 
> On 05/31/2018 11:21 PM, Thomas Huth wrote:
>>> Just a question do we want to clear cfgbuf here, before calling
>>> pxelinux_load_parse_cfg?
>> That's theoretically not necessary. The buffer either gets populated
>> with data, or the function errors out. The code also makes sure that
>> there is a final NUL-character in the buffer:
>>
>> https://github.com/aik/SLOF/blob/64c526a/lib/libnet/pxelinux.c#L169
>>
>> ... but I think I've got to double check that there is also a
>> NUL-character immediately at the end of the downloaded data ... so
>> there's indeed a change required, but likely rather in the SLOF code
>> than here.
> 
> Can't we do that in net_try_direct_tftp_load, or it is better to put
> that in SLOF code?

I've now submitted a patch to SLOF to fix two issues with regards to the
NUL-termination handling there:

https://lists.ozlabs.org/pipermail/slof/2018-June/002201.html

Now it's the duty of the caller to take care of proper NUL-termination.
There is already this line in net_try_direct_tftp_load():

  cfgbuf[rc] = 0;    /* Make sure that it is NUL-terminated */

... so I think we should be fine there.

 Thomas