tshark filter then remove packet and move on
Hi,
I created a small python code to parse a pcap file and count the number of DSCP value, it is working fine, i obtain something like that:
-------------------------------------- DSCP Value Packet num. % -------------------------------------- CS0 0 21097 16 CS1 8 53672 41 AF11 10 0 0 AF12 12 0 0 AF13 14 0 0 CS2 16 0 0 AF21 18 0 0 AF22 20 0 0 AF23 22 0 0 CS3 24 0 0 AF31 26 147 0 AF32 28 0 0 AF33 30 0 0 CS4 32 0 0 AF41 34 54074 41 AF42 36 0 0 AF43 38 0 0 CS5 40 0 0 44 44 0 0 EF 46 0 0 CS6 48 417 0 CS7 56 0 0 --------------------------------------Now i am trying to use the same semantic to parse a pcap file and the idea is to work like a qos policy-map, with class-map. my code looks like this:
request = "tshark -r " + pcap + " -q -z io,stat,0,\ COUNT'(ip.dsfield.dscp)ip.dsfield.dscp&&( "+ af31 + ")',\ COUNT'(ip.dsfield.dscp)ip.dsfield.dscp&&( "+ af22 + ")',\ COUNT'(ip.dsfield.dscp)ip.dsfield.dscp&&( "+ af11 + ")',\ COUNT'(ip.dsfield.dscp)ip.dsfield.dscp&&( "+ cs1 + ")',\ COUNT'(ip.dsfield.dscp)ip.dsfield.dscp&&( "+ default + ")'"
with each variable af31, af22, af11 ... behing string variable like this:
af11 = "(tcp.srcport in { 21 }) or (tcp.dstport in { 21 }) or (tcp.srcport in { 51909 }) or (tcp.dstport in { 51909 }) or (ip.dst == 192.168.85.131) or (ip.dst == 192.168.65.105) or (ip.dst == 192.168.193.50) or (ip.dst == 192.168.246.120) or (ip.src == 192.168.85.131) or (ip.src == 192.168.65.105) or (ip.src == 192.168.193.50) or (ip.src == 192.168.246.120) or (tcp.srcport in { 2051 }) or (tcp.dstport in { 2051 }) or (ip.dst == 192.168.19.213) or (ip.dst == 192.168.114.201) or (ip.dst == 192.168.119.11) or (ip.dst == 192.168.114.200) or (ip.dst == 192.168.119.12) or (ip.dst == 192.168.19.214)"
cs1 = "(tcp)" This is working but not in a policy-map way, for each "count" i would like to mark that packet as being treated, and so that once it goes in a filter, it can't be counted in another filter later
For example in my script the cs1 variable is matching too many things, even though tshark is just applying the filter a correct way, i would like that every packet that has matched something before that filter to be removed from the next filter check.
So the order of my filter is important, and each packet should be matched only once.
Maybe a solution would be to use my first filter, count the packets, then remove those packets from the big pcap file, and then use my second filter etc... but it seems a bit overkill no ?