update,

_ref/computer-networks-project1_elec3120-c33fe69569bd/project-1_elec3120/utils/.gitignore

@@ -0,0 +1 @@
+*.pcap

_ref/computer-networks-project1_elec3120-c33fe69569bd/project-1_elec3120/utils/capture_packets.sh

@@ -0,0 +1,64 @@
+#!/usr/bin/env bash
+# Copyright (C) 2023 Carnegie Mellon University and 
+# Hong Kong University of Science and Technology
+
+# This repository is adopted from the TCP in the 
+# Wild course project from the Computer Networks 
+# course taught at Carnegie Mellon University, and 
+# is used for the Computer Networks (ELEC 3120) 
+# course taught at Hong Kong University of Science 
+# and Technology.
+
+# No part of the project may be copied and/or 
+# distributed without the express permission of 
+# the course staff. Everyone is prohibited from 
+# releasing their forks in any public places.
+
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
+HOST=$(hostname)
+IFNAME=$(ifconfig | grep -B1 10.0.1. | grep -o "^\w*")
+FUNCTION_TO_RUN=$1
+PCAP_NAME=$2
+
+if [ -z "$FUNCTION_TO_RUN" ]
+    then
+        echo "usage: ./capture_packets.sh < start | stop | analyze > PCAP_NAME"
+        echo "Expecting name of function to run: start, stop, or analyze."
+        exit 1
+fi
+
+if [ -z "$PCAP_NAME" ]
+  then
+    PCAP_NAME=$HOST.pcap
+    echo NO PCAP_NAME PARAM SO USING DEFAULT FILE: $PCAP_NAME
+fi
+
+start() {
+    sudo tcpdump -i $IFNAME -w $PCAP_NAME udp > /dev/null 2> /dev/null < \
+        /dev/null &
+}
+
+stop() {
+    sudo pkill -f "tcpdump -i $IFNAME -w $PCAP_NAME udp"
+}
+
+analyze() {
+    tshark -X lua_script:$DIR/tcp.lua -R "cmutcp and not icmp" -r $PCAP_NAME \
+    -T fields \
+    -e frame.time_relative \
+    -e ip.src \
+    -e cmutcp.source_port \
+    -e ip.dst \
+    -e cmutcp.destination_port \
+    -e cmutcp.seq_num \
+    -e cmutcp.ack_num \
+    -e cmutcp.hlen \
+    -e cmutcp.plen \
+    -e cmutcp.flags \
+    -e cmutcp.advertised_window \
+    -e cmutcp.extension_length \
+    -E header=y -E separator=, \
+    -2
+}
+
+$FUNCTION_TO_RUN

_ref/computer-networks-project1_elec3120-c33fe69569bd/project-1_elec3120/utils/prepare_submission.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+# Copyright (C) 2023 Carnegie Mellon University and 
+# Hong Kong University of Science and Technology
+
+# This repository is adopted from the TCP in the 
+# Wild course project from the Computer Networks 
+# course taught at Carnegie Mellon University, and 
+# is used for the Computer Networks (ELEC 3120) 
+# course taught at Hong Kong University of Science 
+# and Technology.
+
+# No part of the project may be copied and/or 
+# distributed without the express permission of 
+# the course staff. Everyone is prohibited from 
+# releasing their forks in any public places.
+
+SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
+
+echo "Preparing submission..."
+echo "Make sure to commit all files that you want to submit."
+
+cd $SCRIPT_DIR/../..
+git archive -o handin.tar.gz HEAD
+
+echo "Upload handin.tar.gz to Gradescope."

_ref/computer-networks-project1_elec3120-c33fe69569bd/project-1_elec3120/utils/tcp.lua

@@ -0,0 +1,72 @@
+-- Copyright (C) 2023 Carnegie Mellon University and 
+-- Hong Kong University of Science and Technology
+
+-- This repository is adopted from the TCP in the 
+-- Wild course project from the Computer Networks 
+-- course taught at Carnegie Mellon University, and 
+-- is used for the Computer Networks (ELEC 3120) 
+-- course taught at Hong Kong University of Science 
+-- and Technology.
+
+-- No part of the project may be copied and/or 
+-- distributed without the express permission of 
+-- the course staff. Everyone is prohibited from 
+-- releasing their forks in any public places.
+
+tcp = Proto("cmutcp", "CMU TCP")
+
+local f_identifier  = ProtoField.uint32("cmutcp.identifier", "Identifier")
+local f_source_port  = ProtoField.uint16("cmutcp.source_port", "Source Port")
+local f_destination_port  = ProtoField.uint16("cmutcp.destination_port", "Destination Port")
+local f_seq_num  = ProtoField.uint32("cmutcp.seq_num", "Sequence Number")
+local f_ack_num  = ProtoField.uint32("cmutcp.ack_num", "ACK Number")
+local f_hlen  = ProtoField.uint16("cmutcp.hlen", "Header Length")
+local f_plen  = ProtoField.uint16("cmutcp.plen", "Packet Length")
+local f_flags  = ProtoField.uint8("cmutcp.flags", "Flags")
+local f_advertised_window  = ProtoField.uint16("cmutcp.advertised_window", "Advertised Window")
+local f_extension_length  = ProtoField.uint16("cmutcp.extension_length", "Extension Length")
+local f_extension_data = ProtoField.string("cmutcp.extension_data", "Extension Data")
+
+tcp.fields = { f_identifier, f_source_port, f_destination_port, f_seq_num, f_ack_num, f_hlen, f_plen, f_flags, f_advertised_window, f_extension_length , f_extension_data}
+
+function tcp.dissector(tvb, pInfo, root) -- Tvb, Pinfo, TreeItem
+   if (tvb:len() ~= tvb:reported_len()) then
+      return 0 -- ignore partially captured packets
+      -- this can/may be re-enabled only for unfragmented UDP packets
+   end
+
+   local t = root:add(tcp, tvb(0,25))
+   t:add(f_identifier, tvb(0,4))
+   t:add(f_source_port, tvb(4,2))
+   t:add(f_destination_port, tvb(6,2))
+   t:add(f_seq_num, tvb(8,4))
+   t:add(f_ack_num, tvb(12,4))
+   t:add(f_hlen, tvb(16,2))
+   t:add(f_plen, tvb(18,2))
+   local f = t:add(f_flags, tvb(20,1))
+   t:add(f_advertised_window, tvb(21,2))
+   t:add(f_extension_length, tvb(23,2))
+   local extension_length = tvb(23,1):int()
+   t:add(f_extension_data, tvb(25,extension_length))
+
+
+   local flag = tvb(20,1):uint()
+
+   if bit.band(flag, 8) ~= 0 then
+      f:add(tvb(20,1), "SYN")
+   end
+   if bit.band(flag, 4) ~= 0 then
+      f:add(tvb(20,1), "ACK")
+   end
+   if bit.band(flag, 2) ~= 0 then
+      f:add(tvb(20,1), "FIN")
+   end
+
+   pInfo.cols.protocol = "CMU TCP"
+end
+
+-- have to put the port for the server here
+local udpDissectorTable = DissectorTable.get("udp.port")
+udpDissectorTable:add("15441", tcp)
+
+io.stderr:write("tcp.lua is successfully loaded\n")