On Tue, 16 Apr 2013 08:04:47 +0900 Isaku Yamahata <[email protected]> wrote:
> On Mon, Apr 15, 2013 at 04:20:04PM -0400, Eric S. Johnson wrote: >> >> >> Please forgive me if I miss a simple solution of have a >> flawed analysis. I am new to both ryu and to python. >> >> >> Ive been using ryu to develop a controller algorithm. I make >> use of the Packet libs to process OF packet in data. >> >> When my ofswitch is connected to "the real world" it >> receives LLDP frames from its upstream (non OF) HP switch >> that are 170 octets of payload. >> >> But the switch only sends 128 of those octets because thats >> what controller/ofp_handler.py says to do around line 198: >> >> set_config = ofproto_parser.OFPSetConfig( >> datapath, ofproto.OFPC_FRAG_NORMAL, >> 128 # TODO:XXX >> ) >> >> That is where miss_send_length is set to 128 >> >> >> The trouble comes when lib/packet/lldp.py is parsing the lldp >> message. It is fine working through the tlvs until it runs out >> of data then the assert len(buf) >= self.len + LLDP_TLV_SIZE >> gets thrown. >> >> The TLV in this case says it is 90 octets long, but the buf >> doesn't have that much left. >> >> So.... >> >> What would be the way to fix this? >> >> - up the miss_send_length ? >> - have lldp.py recognise it has run out of buf and stop parsing >> in a somewhat gracefull fashion? (and only partially parse the packet) >> - Just have packet lib stop parsing lldp (comment out the register) > > - don't rely on table-miss. install the rule that > matches lldp with output action to controller, OFPP_CONTROLLER, > and arbitrary needed max_len. You don't even need to use OFPP_CONTROLLER. You can send lldp packets to another port and deploy a program that handles lldp packets. The controller and the lldp handling program work together via whatever you like. But 128 is totally random. I'm happy to increase the default value for a full ethernet frame. We need to provide a way to configure it later. ------------------------------------------------------------------------------ Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis & visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter _______________________________________________ Ryu-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ryu-devel
