skelton for the flow abstractor (TCP)

fabs_skel.py

import socket
import sys

class fabs_skel:
    def openif(self, path):
        self._path = path
        self._session = {}

        self.__sock = socket.socket(socket.AF_UNIX)

        try:
            self.__sock.connect(path)
        except socket.error, msg:
            print >>sys.stderr, msg
            sys.exit(1)

    def run(self):
        sf = self.__sock.makefile()

        while True:
            line = sf.readline()
            h = {}
            dfrom = 0

            # read header
            try:
                self.__parse_header(line, h)

                # generate session ID
                sid   = (h['ip1'], h['ip2'], h['port1'], h['port2'], h['hop'])

                event = h['event']

                if event == 'DATA':
                    dlen  = int(h['len'])
                    dfrom = int(h['from'])
            except KeyError, msg:
                print >>sys.stderr, "illeal header:", msg
                sys.exit(1)

            # handle event
            if event == 'CREATED':
                self._session[sid] = ([], [])
                self.in_event(h, sid, event, dfrom)
            elif event == 'DESTROYED':
                del self._session[sid]
                self.in_event(h, sid, event, dfrom)
            elif event == 'DATA':
                # read data
                data = sf.read(dlen)
                if sid in self._session:
                    if dfrom == 1:
                        self._session[sid][0].append(data)
                    else:
                        self._session[sid][1].append(data)

                    self.in_event(h, sid, event, dfrom)

    def in_event(self, header, sid, event, dfrom):
        # data is stored to self._session[sid]

        # dfrom indicates source of data
        # this means that new arrival data is stored to
        # self._session[sid][dfrom - 1] 

        # just print
        print header
        if event == 'DATA':
            print self._session[sid][dfrom - 1].pop(0)
        

    def __parse_header(self, line, header):
        line = line.strip()

        for kv in line.split(','):
            sp = kv.split('=')
            header[sp[0]] = sp[1]

if __name__ == '__main__':
    fabs = fabs_skel()

    fabs.openif("/tmp/sf-tap/tcp/http")
    fabs.run()