support craft packet from scratch

test/packet_tool/split_pcap.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+
+if [ -z "$1" ]; then
+    echo "Usage: $0 input.pcap"
+    exit 1
+fi
+
+input_pcap="$1"
+output_dir="split_output/"
+rm -rf $output_dir && mkdir -p $output_dir
+
+num=$(tshark -r "$input_pcap" -T fields -e frame.number | tail -n 1)
+echo -e "\e[32m input pcap $input_pcap has $num packets\e[0m"
+
+for ((i = 1; i <= num; i++)); do
+    tshark -r "$input_pcap" -Y "frame.number==$i" -w "$output_dir/packet_$i.pcap"
+done
+
+echo -e "\e[32m split pcap is saved in $output_dir\e[0m"