search

frenetic-lang / frenetic

The Frenetic Programming Language and Runtime System
http://www.frenetic-lang.org/
Other
223 stars 51 forks source link

Openflow13 breaks when parsing Packet_In message #421

Open mulias opened 9 years ago

mulias commented 9 years ago

The openflow13 message parser breaks with a stack trace that looks like this:

"invalid bounds in Cstruct.BE.get_uint16 32,4 off=4 len=2" "Called from file \"openflow/lib/OpenFlow0x04.ml\", line 838, characters 26-48" "Called from file \"openflow/lib/OpenFlow0x04.ml\", line 1855, characters 16-41" "Called from file \"openflow/lib/OpenFlow0x04.ml\", line 2350, characters 28-42" "Called from file \"openflow/lib/OpenFlow0x04.ml\", line 2351, characters 24-42" "Called from file \"openflow/lib/OpenFlow0x04.ml\", line 2357, characters 20-41" "Called from file \"openflow/lib/OpenFlow0x04.ml\", line 3535, characters 30-59" "Called from file \"openflow/lib/OpenFlow0x04.ml\", line 7012, characters 34-58"

Note that the line numbers match up with commit 7e2316b935c8b9b9710f763cde48f28cd75c1d17, not the current file.

arjunguha commented 9 years ago

FYI, this is a PACKET_IN message, when it receives some sort of IPv6 packet. We often run Frenetic in VMs that have IPv6 disabled.

fugitifduck commented 9 years ago

Strange, it passed the unit test last year. As I understand, there is a problem on the cstruct ofp_uint48 (defined at https://github.com/frenetic-lang/ocaml-openflow/blob/master/lib/OpenFlow0x04.ml#L799 ). On what Arch do you run openflow ?

arjunguha commented 9 years ago

This was witnessed running OpenVSwitch on Ubuntu 14.04

fugitifduck commented 9 years ago

is it possible to have a sample of the IPv6 packet ? (and by arch I mean x86 or x64)

arjunguha commented 9 years ago

64-bit. We didn't capture the precise packet, unfortunately.

fugitifduck commented 9 years ago

I can't identify the issue on ocaml-openflow code. Maybe the packet was malformed ? (or the ofp_uint48 struct was wrongly code, but there will be issue in other messages).

mcanini commented 9 years ago

This should be fairly easy to reproduce, if it is indeed related to IPv6. Just activate a mininet VM and do not switch off IPv6. Did you try that?