1

在J1939协议中使用带有socketcan的python，似乎recvfrom()在数据超过8个字节时没有返回接口。在 J1939 协议中，当数据字节数超过 8 个时，会发送多个 CAN 报文，因为一条 CAN 报文最多只能容纳 8 个数据字节。

使用下面的程序，我看到接口返回 8 个数据字节，但不是 9 个数据字节。

是 Python 的问题还是内核的问题？如果这确实是一个错误，我们如何才能找到合适的开发人员？

谢谢你。

#!/usr/bin/env python3

import socket

send_socket = socket.socket(socket.PF_CAN, socket.SOCK_DGRAM, socket.CAN_J1939) 

interface = "vcan0"

send_socket_src_name = socket.J1939_NO_NAME
send_socket_src_pgn = socket.J1939_NO_PGN 
send_socket_src_addr = 0x80
send_socket_src_sck_addr = (interface, send_socket_src_name, send_socket_src_pgn, send_socket_src_addr)
send_socket.bind(send_socket_src_sck_addr)

send_socket_dest_name = socket.J1939_NO_NAME 
send_socket_dest_pgn = 0x2300
send_socket_dest_addr = 0x81
send_socket_dest_sck_addr = (interface, send_socket_dest_name, send_socket_dest_pgn, send_socket_dest_addr)
send_socket_data_8_bytes = b'\x01\x02\x03\x04\x05\x06\x07\x08'
send_socket_data_9_bytes = b'\x01\x02\x03\x04\x05\x06\x07\x08\x09'

receive_socket = socket.socket(socket.PF_CAN, socket.SOCK_DGRAM, socket.CAN_J1939) 

receive_socket_src_name = socket.J1939_NO_NAME
receive_socket_src_pgn = socket.J1939_NO_PGN 
receive_socket_src_addr = 0x81 
receive_socket_src_sck_addr = (interface, receive_socket_src_name, receive_socket_src_pgn, receive_socket_src_addr)
receive_socket.bind(receive_socket_src_sck_addr)

send_socket.sendto(send_socket_data_8_bytes, send_socket_dest_sck_addr)
(data, sock_addr) = receive_socket.recvfrom(128)
(interface, src_name, src_pgn, src_addr) = sock_addr
print(f"interface for 8 data bytes:{interface}")

send_socket.sendto(send_socket_data_9_bytes, send_socket_dest_sck_addr)
(data, sock_addr) = receive_socket.recvfrom(128)
(interface, src_name, src_pgn, src_addr) = sock_addr
print(f"interface for 9 data bytes:{interface}")

receive_socket.close()
send_socket.close()

这是输出：

interface for 8 data bytes:vcan0
interface for 9 data bytes:
4

0 回答 0