Hi, Hamish Moffatt wrote: > On Sun, Oct 07, 2007 at 09:58:06PM +0200, Tihomir Heidelberg - 9a4gl wrote: > >> Using kernel 2.6.21.6 here. If you write to AX.25 socket bytes more then >> MTU, write will return -1 and errno will be set to 90 (EMSGSIZE = >> [Message too long]). >> > Is it sensible to fragment raw AX.25 packets? I think that would depend > on what the next layer protocol is. > For APRS, each packet is significant (ie it's datagram rather than stream > oriented) so fragmenting a packet would not be correct. > No, only SOCK_SEQPACKET should be fragmented. APRS is using SOCK_DGRAM and in most cases SOCK_DGRAM should not be fragmented, but I think we should leave that to application. Comparing to IP world, TCP sockets may survive additional fragmentation, but UDP maybe. >> By the way, this problem is having OpenBCM V1.07b3 >> > In your application (the other end of call, for example?) the packets > may just be a stream and therefore fragmenting at arbitrary points would > be ok. Although SOCK_SEQPACKET doesn't sound right in that case. > > Hm, you mean I should use SOCK_STREAM ? As I see that kind of socket is not supported in AX.25 stack, right ? When it would be, then it makes sense to fragment for SOCK_STREAM and return EMSGSIZE for SOCK_SEQPACKET.
Hamish Moffatt wrote: > The change seems to be requested here: > http://oss.sgi.com/archives/netdev/2004-01/msg00097.html > > with the rationale that there is no fragmentation logic, as I suggested > in my other followup (which hasn't arrived back here yet...) But, we do have fragmentation logic in ax25_output. 73 de Tihomir, 9a4gl - To unsubscribe from this list: send the line "unsubscribe linux-hams" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
