On Wed, Jan 29, 2014 at 12:20:50PM +0000, Martin Townsend wrote: > Hi Alex, > > I've been testing your latest changes and I'm now able to send large > pings and can see the fragmented packets on wireshark :) I can now get > the libcoap examples working (which didn't on the 3.10 kernel I was > using before). :) > oh libcoap is nice, I use CoAP too and had a idea to implement a CoAP userspace "filesystem" with a coap server and coap fuse client on the other side. The coap examples runs on my side as well.
There exists also a firefox plugin "Copper" maybe you don't know it. It's really cool as a coap client. [1] The server can simply offer some sysfs entries (sensoring data, leds, buttons, etc...) > One thing I have noticed is that it fragments earlier that I expected, > if I ping with > ping6 -s 93 fe80::a200:0:0:2%lowpan0 > > Then I get a 125 byte frame, so I expected -s 94 to not fragment but it > did. I'm wondering if this is due to the fact that my driver has set > the IEEE802154_HW_OMIT_CKSUM flag. If my understanding of this flag is > correct then it means that the HW is handling the Checksum at the PHY > layer so the MAC layer does add a CRC in the Tx and conversely check it > on the Rx. So this would give us an extra 2 bytes to play with and I'm > wondering if this would account for these 2 bytes? > There is one point in fragmentation code which decide if we need fragmentation or not, see [2]. Maybe we need to change this calculation to remove the two bytes if IEEE802154_HW_OMIT_CKSUM is set. I need to take a look into that, or maybe you want try to remove the two bytes and check if this still works (that it's a hacky testing, but I would check this at first). - Alex [1] https://addons.mozilla.org/de/firefox/addon/copper-270430/ [2] https://github.com/linux-wpan/linux-net-next/blob/6lowpan_pending_patches/net/ieee802154/6lowpan_core.c#L1071 ------------------------------------------------------------------------------ WatchGuard Dimension instantly turns raw network data into actionable security intelligence. It gives you real-time visual feedback on key security issues and trends. Skip the complicated setup - simply import a virtual appliance and go from zero to informed in seconds. http://pubads.g.doubleclick.net/gampad/clk?id=123612991&iu=/4140/ostg.clktrk _______________________________________________ Linux-zigbee-devel mailing list Linux-zigbee-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-zigbee-devel
