Re: VDR 0.63-deti Update

["Ralph Metzler <" <rjkm@netcologne.de>]

Carsten Koch writes:
 > "Ralph Metzler <" wrote:
 > ...
 > > You can also statically allocate 4096 bytes. This is the maximum
 > > allowed for EIT sections (AFAIR including the section header, but I
 > > need to check this).
 > 
 > You may be right, but I would always at least check the length
 > before trusting my life to it. ;-)
 > 
 > After all, it's a 16 bit length and (at least theoretically) 
 > it can become up to 65535 bytes long.
 >
 > I have recently traced a similar problem and saw lengths up
 > to 57000 bytes in the trace output. Maybe that was caused by 
 > the fact that two programs were accessing /dev/vbi simultaneously, 
 > but in any event I'd consider
 >       allocate fixed buffer < 65565 bytes
 >       read data length into 16-bit value
 >       read this amount into buffer
 > highly unsave....
 > 

I looked up all section definitions I could find and they all have a 
section length entry of only 12 Bits. So, 4096 is enough and I have 
to admit that there is a little bug in DVB/libdvb/DVB.hh.
In GetSection() seclen should be anded with 0xfff.
The section header is included in the 4096 byte limit. For EIT
sections they specifically say that the section_length entry
has a maximum of 4093 so that the whole section has a max. of 4096.


Ralph