non blocking reception works

This commit is contained in:
uhi22 2022-10-14 23:36:03 +02:00
parent ec03fd05ce
commit 07f33d3bc8
3 changed files with 65 additions and 22 deletions

15
demo_pcap.py Normal file
View file

@ -0,0 +1,15 @@
import pcap
print("Interfaces:\n" + '\n'.join(pcap.findalldevs()))
print("ex_name")
for i in range(0, 10):
strInterfaceName = pcap.ex_name("eth"+str(i))
if (strInterfaceName == '\\Device\\NPF_{E4B8176C-8516-4D48-88BC-85225ABCF259}'):
print("This is the wanted Ethernet adaptor.")
print("eth"+ str(i) + " is " + strInterfaceName)
sniffer = pcap.pcap(name=None, promisc=True, immediate=True, timeout_ms=50)
addr = lambda pkt, offset: '.'.join(str(pkt[i]) for i in range(offset, offset + 4))
for ts, pkt in sniffer:
print('%d\tSRC %-16s\tDST %-16s' % (ts, addr(pkt, sniffer.dloff + 12), addr(pkt, sniffer.dloff + 16)))

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@ -127,30 +127,63 @@ class pyPlcHomeplug():
addToTrace("transmitting test frame...") addToTrace("transmitting test frame...")
self.composeTestFrame() self.composeTestFrame()
self.sniffer.sendpacket(bytes(self.mytransmitbuffer)) self.sniffer.sendpacket(bytes(self.mytransmitbuffer))
def findEthernetAdaptor(self):
self.strInterfaceName="eth0" # default, if the real is not found
print("Interfaces:\n" + '\n'.join(pcap.findalldevs()))
for i in range(0, 10):
strInterfaceName = pcap.ex_name("eth"+str(i))
if (strInterfaceName == '\\Device\\NPF_{E4B8176C-8516-4D48-88BC-85225ABCF259}'):
print("This is the wanted Ethernet adaptor.")
self.strInterfaceName="eth"+str(i)
print("eth"+ str(i) + " is " + strInterfaceName)
def __init__(self, callbackAddToTrace=None, callbackShowStatus=None): def __init__(self, callbackAddToTrace=None, callbackShowStatus=None):
self.mytransmitbuffer = bytearray("Hallo das ist ein Test", 'UTF-8') self.mytransmitbuffer = bytearray("Hallo das ist ein Test", 'UTF-8')
self.nPacketsReceived = 0
self.callbackAddToTrace = callbackAddToTrace self.callbackAddToTrace = callbackAddToTrace
self.callbackShowStatus = callbackShowStatus #self.sniffer = pcap.pcap(name=None, promisc=True, immediate=True, timeout_ms=50) self.callbackShowStatus = callbackShowStatus
# eth3 bedeutet: Dritter Eintrag von hinten, in der Liste der Interfaces, die von pcap.findalldevs geliefert wird. #self.sniffer = pcap.pcap(name=None, promisc=True, immediate=True, timeout_ms=50)
# Verbesserungsbedarf: Interface namensbasiert auswählen. # eth3 means: Third entry from back, in the list of interfaces, which is provided by pcap.findalldevs.
self.sniffer = pcap.pcap(name="eth3", promisc=True, immediate=True, timeout_ms=50) # Improvement necessary: select the interface based on the name.
# For debugging of the interface names, we can patch the file
# C:\Users\uwemi\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.10_qbz5n2kfra8p0\LocalCache\local-packages\Python310\site-packages\pcap\_pcap_ex.py,
# in the function
# def name(name: bytes) -> bytes:
# in the place after
# if i == idx:
# print("index match at " + str(i) + " dev name=" + str(dev.name) + " dev.description=" + str(dev.description))
# This will print the description of the used interface.
#
# Patch for non-blocking read-iteration:
# in _pcap.py, function def __next__(self), in the case of timeout (if n==0), we need to "raise StopIteration" instead of "continue".
#
self.findEthernetAdaptor()
self.sniffer = pcap.pcap(name=self.strInterfaceName, promisc=True, immediate=True, timeout_ms=50)
self.sniffer.setnonblock(True)
print("sniffer created at " + self.strInterfaceName)
def addToTrace(s): def addToTrace(s):
self.callbackAddToTrace(s) self.callbackAddToTrace(s)
def showStatus(self, s):
self.callbackShowStatus(s)
def mainfunction(self): def mainfunction(self):
# print("will evaluate self.sniffer")
for ts, pkt in self.sniffer: # attention: for using this in non-blocking manner, we need the patch described above.
self.nPacketsReceived+=1
print('%d' % (ts))
#if (self.isHomeplug(pkt)):
# self.showMacAddresses(pkt)
# showAsHex(pkt)
# if (pkt[15]==0x64): #SLAC_Request
# self.sendTestFrame()
#
#else:
# addToTrace("(other)")
self.showStatus("nPacketsReceived=" + str(self.nPacketsReceived))
for ts, pkt in self.sniffer:
#print('%d' % (ts))
if (self.isHomeplug(pkt)):
self.showMacAddresses(pkt)
showAsHex(pkt)
if (pkt[15]==0x64): #SLAC_Request
self.sendTestFrame()
else:
addToTrace("(other)")
def close(self): def close(self):
self.sniffer.close() self.sniffer.close()

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@ -6,9 +6,6 @@
#------------------------------------------------------------ #------------------------------------------------------------
import pyPlcHomeplug import pyPlcHomeplug
class pyPlcWorker(): class pyPlcWorker():
def __init__(self, callbackAddToTrace=None, callbackShowStatus=None): def __init__(self, callbackAddToTrace=None, callbackShowStatus=None):
print("initializing pyPlcWorker") print("initializing pyPlcWorker")
@ -27,11 +24,9 @@ class pyPlcWorker():
def mainfunction(self): def mainfunction(self):
self.nMainFunctionCalls+=1 self.nMainFunctionCalls+=1
self.showStatus("pyPlcWorker loop " + str(self.nMainFunctionCalls)) #self.showStatus("pyPlcWorker loop " + str(self.nMainFunctionCalls))
#self.hp.mainfunction() self.hp.mainfunction() # call the lower-level worker
def handleUserAction(self, strAction): def handleUserAction(self, strAction):
self.strUserAction = strAction self.strUserAction = strAction
self.addToTrace("UserAction " + strAction) self.addToTrace("UserAction " + strAction)