gRouter is the core of GINI(http://cgi.cs.mcgill.ca/~anrl/gini/) gRouter is written from scratch with most of the functionalities and controls found in a general router. gRouter provides a simple but flexible implementation that can be easily extended by students.
------------ Threads ------------
grouter------... |-- threads |-- . |-- PacketProcessor -> checking workQ |-- DecisionProcessor -> checking DecisionQ and process in corresponding module.
------------ Threads ------------ packet -> router | v workQ : lable | v DecisionQ ---> check flowtable for module[3 default protocol: ARP IP ICMP] ^ | | C v lableNext <--- processor | -Python-
v
call wrapped function: IP layer output interface provided.
TODO 1. handle return from python. 2. merge flowtable(into flow_match in openflow...)
------------ Developing Notes ------------ /* config struct for module importing */ typedef struct _module_config_t { char name; / name of the module / ushort protocol; / protocol number of the module */ void processor; / the function processing the packet */ void command; / the function registered for command line */ char command_str; / the command registered for [command function] */ char shelp; / short help message */ char usage; / instructions of using the module */ char lhelp; / help message in detail */ } module_config_t;
/* class for python / / config */
class module_config: def init(self, name="module", protocol=255, command_string="", short_help="", usage="", long_help="") def to_tuple(self)
/* GPacket */ class GPacket: def init(self,ip_payload=None) def dissemble(self, msg) def assemble(self)
/*
- module prototype / / Python module / / 0. import _GINIC as GINIC /* 1. implement public function / def Config(): config = module_config(name="udp", protocol=17, command_string="nc", short_help="udp function", usage="nc -l [port] nc [IP][port]", long_help="sending and listening to udp packet") return config.to_tuple() / 2. implement public function Protocol_Processor
-
a. argument is gPacket_t from C -
b. return value to be determined..
/ def Protocol_Processor(pkt) / 3. implement public function Command_Line
-
a. argument is the option from C
*/ def Command_Line(str)
/*
- Helper functions
- Calling by GINIC.IPPayload() */
/* returns the IP payload of a gpackeet / PyObject * IPPayload(gpacket_t * gpacket); / helper function for gpacket / gpacket_t * createGPacket(PyObject * pkt); / returns a new packet with only ip_payload changed / gpacket_t * assembleWithIPPayload(PyObject * gpacket_py, PyObject * payload); / returns a gpacket with ip_payload as input */ gpacket_t * createGPacketWithIPPayload(PyObject * payload); PyObject getGPacketMetaheaderLen(); PyObject getGPacketString(gpacket_t * gpacket);
/* Interface for C function in GINI */ /1. IP Layer Out Put/ GINIC.IPOutgoingPacket(gpacket_t *out_gpkt, uchar dst_ip, int size, int newflag, int src_prot); / sample */ out_gpkt: gPacket_t.assemble() dst_ip: ip address of destination in NETWORK ENDIAN. // TODO: Use typemap? so that could call us [192.168.1.2] or '192.168.1.2' size: packet size newflag: 0 use old packet. only ip_payload will be updated. 1 create new packet. ip_payload is attached to an empty header.
/* C Module / / Similar implementation... */
/* Import module */ addmod [module name] [language]
sample: addmod udp python