def buildRequest(src, dst, payload='', ipId=0):
udpPkt = Udp()
udpPkt.srcport = src[2]
udpPkt.dstport = dst[2]
if isinstance(payload, str):
udpPkt.len += len(payload)
else:
udpPkt.len += len(payload.hdr())
udpPkt.set_payload(payload)
udpPkt.parsed = True
ipPkt = Ipv4()
ipPkt.flags = Ipv4.DF_FLAG
ipPkt.srcip = src[1]
ipPkt.dstip = dst[1]
ipPkt.id = ipId
ipPkt.protocol = Ipv4.UDP_PROTOCOL
ipPkt.set_payload(udpPkt)
ipPkt.iplen += udpPkt.len
ipPkt.parsed = True
udpPkt.csum = checksum(udpPkt)
ethPkt = Ethernet()
ethPkt.src = src[0]
ethPkt.dst = dst[0]
ethPkt.type = Ethernet.IP_TYPE
ethPkt.set_payload(ipPkt)
ethPkt.parsed = True
return ethPkt
def buildRequest(src=ETHER_ANY, dst=ETHER_ANY, typ=Ethernet.IP_TYPE, payload=''):
packet = Ethernet()
packet.src = src
packet.dst = dst
packet.type = typ
packet.next = payload
# TODO build packet.arr
packet.parsed = True
return packet
def buildResponse(req, packet, **kwargs):
resp = Ethernet()
resp.src = req.dst
resp.dst = req.src
resp.type = req.type
resp.set_payload(packet)
if len(kwargs) != 0:
for key in kwargs.keys():
if key not in resp.__dict__.keys():
continue
setattr(resp, key, kwargs[key])
resp.parsed = True
return resp
def buildArpRequest(srcMac, srcIp, dstIp):
arpPkt = Arp()
arpPkt.hwsrc = srcMac
arpPkt.hwlen = 6
arpPkt.protolen = 4
arpPkt.opcode = Arp.REQUEST
arpPkt.protosrc = srcIp
arpPkt.protodst = dstIp
arpPkt.parsed = True
ethPkt = Ethernet()
ethPkt.src = srcMac
ethPkt.dst = ETHER_BROADCAST
ethPkt.type = Ethernet.ARP_TYPE
ethPkt.set_payload(arpPkt)
ethPkt.parsed = True
return ethPkt
def buildFrameFromConn(conn, tcpPkt):
arr = getattr(tcpPkt, "arr", None)
if arr is None:
tcpPkt.arr = array("B", tcpPkt.hdr(tcpPkt.payload, calc_checksum=False))
tcpPkt.arr.fromstring(tcpPkt.payload)
tcpPkt.tcplen = len(tcpPkt.arr)
offres = len(tcpPkt.hdr(tcpPkt.payload, calc_checksum=False)) * 4
tcpPkt.off = offres >> 4
tcpPkt.res = offres & 0x0F
ipPkt = Ipv4()
ipPkt.flags = Ipv4.DF_FLAG
ipPkt.srcip = conn.my_ip
ipPkt.dstip = conn.other_ip
ipPkt.protocol = Ipv4.TCP_PROTOCOL
log.info("tcp packet = %s" % str(tcpPkt))
log.info("srcip = %s" % str(ipPkt.srcip))
log.info("dstip = %s, unsigned = %x" % (str(ipPkt.dstip), ipPkt.dstip.toUnsigned()))
if not (isSyn(tcpPkt) and isAck(tcpPkt)):
ipPkt.id = conn.ipId if conn.ipId is not None else random.randint(0, 2 ** 16 - 1)
conn.ipId = ipPkt.id + 1
else:
ipPkt.id = 0
conn.ipId = random.randint(0, 2 ** 16 - 1)
tcpPkt.payload_len = len(tcpPkt.next)
tcpPkt.prev = ipPkt
ipPkt.iplen = len(ipPkt.hdr(tcpPkt)) + tcpPkt.tcplen
tcpPkt.csum = tcpPkt.checksum()
ipPkt.set_payload(tcpPkt)
ethPkt = Ethernet()
ethPkt.src = conn.my_mac
ethPkt.dst = conn.other_mac
ethPkt.type = Ethernet.IP_TYPE
ethPkt.set_payload(ipPkt)
return ethPkt
