Re: AX.25 Kernel - problem - ax25_sendmsg returns EMSGSIZE !

[Tihomir Heidelberg - 9a4gl <9a4gl@hamradio.hr>]

Hi,

Hamish Moffatt wrote:
> socket(7) doesn't make any distinction between SOCK_DGRAM and
> SOCK_SEQPACKET with regard to fragmentation. SOCK_SEQPACKET just adds
> reliability and order.
>
>   

Hm, socket(2) or (7) ? Both documents do not mention fragmentation. But,
according to socket(2), difference between SOCK_STREAM and
SOCK_SEQPACKET is that first one supports out-of-band data which is not
(easy) doable in AX.25 world. So, it is ok to use SOCK_SEQPACKET for
what we/I call AX.25 connection.
> Yes, except that it doesn't exactly make sense to have streams on a raw
> socket (which is I guess why they are not supported for AX.25). Streams
> would be implemented by the transport layer and above, which is above
> what a raw socket provides.
>   

Hm, as I see AX.25 sockets supports SOCK_DGRAM, SOCK_SEQPACKET and
SOCK_RAW. I am not talking about raw and I am not using raw socket.
IMHO, users of raw sockets should be aware of MTU and I would not
fragment raw sockets in kernel.

What I want is to have SOCK_SEQPACKET reliable, accepting any amount of
data and on write returning number of bytes accepted. I do not care much
if fragmentation will take place or not, but currently I do not see any
reason why not.

73 de Tihomir Heidelberg, 9a4gl