python can socket

1import socket
2
3HOST = '127.0.0.1'  # Standard loopback interface address (localhost)
4PORT = 65432        # Port to listen on (non-privileged ports are > 1023)
5
6with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
7    s.bind((HOST, PORT))
8    s.listen()
9    conn, addr = s.accept()
10    with conn:
11        print('Connected by', addr)
12        while True:
13            data = conn.recv(1024)
14            if not data:
15                break
16            conn.sendall(data)

1       import socket
2       import struct
3       import sys
4
5       # CAN frame packing/unpacking (see `struct can_frame` in <linux/can.h>)
6       can_frame_fmt = "=IB3x8s"
7
8       def build_can_frame(can_id, data):
9               can_dlc = len(data)
10               data = data.ljust(8, b'\x00')
11               return struct.pack(can_frame_fmt, can_id, can_dlc, data)
12
13       def dissect_can_frame(frame):
14               can_id, can_dlc, data = struct.unpack(can_frame_fmt, frame)
15               return (can_id, can_dlc, data[:can_dlc])
16
17       if len(sys.argv) != 2:
18               print('Provide CAN device name (can0, slcan0 etc.)')
19               sys.exit(0)
20
21       # create a raw socket and bind it to the given CAN interface
22       s = socket.socket(socket.AF_CAN, socket.SOCK_RAW, socket.CAN_RAW)
23       s.bind((sys.argv[1],))
24
25       while True:
26               cf, addr = s.recvfrom(16)
27
28               print('Received: can_id=%x, can_dlc=%x, data=%s' % dissect_can_frame(cf))
29
30               try:
31                       s.send(cf)
32               except socket.error:
33                       print('Error sending CAN frame')
34
35               try:
36                       s.send(build_can_frame(0x01, b'\x01\x02\x03'))
37               except socket.error:
38                       print('Error sending CAN frame')
39