Function decode_pcapng

decode_pcapng.py:226–288

(path, bus_id, dev, second_first)

def decode_pcapng(path, bus_id, dev, second_first):
    img1_binary = [] # [(addr, row)]
    img2_binary = [] # [(addr, row)]
    with open(path, "rb") as f:
        scanner = FileScanner(f)
        block_no = 1
        for i, block in enumerate(scanner):
            if type(block) is blocks.EnhancedPacket or type(block) is blocks.SimplePacket:
                img1 = False
                img2 = False

                #print(block_no, block.packet_len, block.packet_data)
                packet = block.packet_data
                urb = usb_urb(packet[0:usb_urb_sz])

                # Filter device
                if urb.bus_id == bus_id and urb.device == dev:
                    img1 = True
                elif urb.bus_id == bus_id and urb.device == dev+1:
                    img2 = True
                else:
                    #print(f"Other device bus_id: {urb.bus_id}, dev: {urb.device}")
                    #print(f"bus_id: {bus_id}, dev_id: {dev}")
                    continue

                # Only consider outgoing packets
                if urb.irp_info != 0:
                    continue

                #print(block_no, urb)

                # Skip small packets
                if urb.data_length != 140:
                    continue

                if DEBUG:
                    print(block_no, "  ", format_hex(packet))

                hid_packet = packet[36:]
                if DEBUG:
                    print(block_no, "  ", format_hex(hid_packet))

                addr = (hid_packet[3] << 8) + hid_packet[2]
                payload = hid_packet[4:]
                if VERBOSE:
                    print("{:4d} 0x{:08X} {}".format(block_no, addr, format_hex(payload)))

                if img1:
                    if second_first:
                        img2_binary.append((addr, payload))
                    else:
                        img1_binary.append((addr, payload))
                elif img2:
                    if second_first:
                        img1_binary.append((addr, payload))
                    else:
                        img2_binary.append((addr, payload))