diff --git a/PCAP Output/README.md b/PCAP Output/README.md index 63527ca..a5a7960 100644 --- a/PCAP Output/README.md +++ b/PCAP Output/README.md @@ -3,10 +3,40 @@ This uses LoRa packet forwarder to forward the LoRa packets to a localhost with port 1700. Once packet forwarder is running, another process executes tcpdump that captures a loopback interface and outputs it as a pcap file. Afterwarads, we remove the Ethernet, IP and UDP headers (14+20+8) of the pcap file and set linktype to user (147). Finally, the edited pcap file is loaded to Wireshark, where the protocol is changed to LoRaWAN. ## Instructions -* Users should flash the correct configuration of LoRadar on the microSD card -`sudo apt-get update -y` -`sudo apt-get install -y bittwist` -`sudo apt-get install -y tcpdump` - -`sudo tcpdump -s 0 -AUq port 1700 -w trial.pcap` -`bittwiste -I trial.pcap -O dump_dlt_user.pcap -M 147 -D 1-42` +1. Users should first flash the correct configuration of LoRadar on the microSD card. +2. Clone the `local_packet_forwader` directory to the Raspberry Pi. +3. Install the following dependencies. + ``` + sudo apt-get update -y + sudo apt-get install -y bittwist + sudo apt-get install -y tcpdump + sudo apt-get install -y screen + ``` +4. Create a screen session. + ``` + screen + ``` +5. Within this screen session, `cd` to the 'local_packet_forwarder' directory within Raspberry Pi. Execute the following to start capturing packets on port 1700 and outputting it as `capture.pcap`: + ``` + cd lora_pkt_fwd/ + sudo tcpdump -s 0 -AUq port 1700 -w capture.pcap + ``` +6. Detach from the screen by pressing `ctrl + a + d` on the keyboard. +7. Start a new screen session by typing `screen` in the terminal. +8. `cd` to the 'local_packet_forwarder' directory within Raspberry Pi. Execute the following to start forwarding packets to localhost: + ``` + cd lora_pkt_fwd/ + sudo chmod +x lora_pkt_fwd + sudo ./lora_pkt_fwd + ``` +9. To terminate the packet forwarder session, press `ctrl + c` on the keyboard and type `exit` in the terminal to end the screen session. +10. Navigate to the other screen by typing `screen -r -d` in the terminal. +11. End the packet capture session by pressing `ctrl + c` on the keyboard. You will now see a new `capture.pcap` file created in the directory. +12. Process the .pcap data to remove the unnecessary Ethernet, IP and UDP headers (14+20+8) of the pcap file and set linktype to user (147). This process will intake the `capture.pcap` file and output it as `processed_capture.pcap`. + ``` + bittwiste -I capture.pcap -O dump_dlt_user.pcap -M 147 -D 1-42 + ``` +13. Open the `processed_capture.pcap` file in Wireshark. +14. Navigate to `Edit -> Preferences -> Protocols -> DLT_USER -> Edit...`. +15. Input `lorawan` as the Payload protocol, `14` as the header size, then click OK. +16. You will now see LoRaWAN fields under the frame information.