python - 套接字不会绑定(bind) : no such device

Question

所以我有这段 Python 3 代码:

import socket
s = socket.socket(socket.AF_PACKET, socket.SOCK_RAW)
s.bind(('eth0', 0))
s.send(eth_packet)

此代码适用于我的 Raspberry Pi，但不适用于我的外部服务器。当我尝试在我的外部服务器上运行它时，我得到:

# sudo python3 test.py
s.send(eth_packet)
socket.error: [Errno 19] No such device

然后我检查了网络接口(interface)输出(通过 python 脚本): 外部服务器(debian):

['lo [index=1, IPv4=127.0.0.1, IPv6=::1]', 'eth0:0 [index=2, IPv4=xxxxx, IPv6=None]', 'eth0 [index=2, IPv4=yyyyyy, IPv6=zzzzzzz]']

树莓派:

['lo [index=1, IPv4=127.0.0.1, IPv6=None]', 'eth0 [index=2, IPv4=rrrrr, IPv6=None]']

谁能解释一下这是怎么回事？我只想发送一条手工制作的消息，但这个错误一直困扰着我，这可能是我服务器驱动程序的问题吗？这与 ifconfig 的结果相同。

编辑

好的，我在这个例子中使用了 strace:

#!/usr/bin/env python3

import socket
import binascii
import struct

test= '000a959d6816'
packet= struct.pack("!6s", binascii.unhexlify(bytes(test, 'UTF-8')))
s = socket.socket(socket.AF_PACKET, socket.SOCK_RAW)
s.bind(('eth0', 0))
s.send(packet)

这是关于 strace 的重要部分:

socket(PF_PACKET, SOCK_RAW, 0)          = 3
ioctl(3, SIOCGIFINDEX, {ifr_name="eth0", ifr_index=2}) = 0
bind(3, {sa_family=AF_PACKET, proto=0000, if2, pkttype=PACKET_HOST, addr(0)={0, }, 20) = 0
sendto(3, "\0\n\225\235h\26", 6, 0, NULL, 0) = -1 ENXIO (No such device or address)
open("test.py", O_RDONLY)               = 4
fstat(4, {st_mode=S_IFREG|0644, st_size=247, ...}) = 0
ioctl(4, SNDCTL_TMR_TIMEBASE or TCGETS, 0x7fff86c5f090) = -1 ENOTTY (Inappropriate ioctl for device)
fstat(4, {st_mode=S_IFREG|0644, st_size=247, ...}) = 0
lseek(4, 0, SEEK_CUR)                   = 0
dup(4)                                  = 5
fcntl(5, F_GETFL)                       = 0x8000 (flags O_RDONLY|O_LARGEFILE)
fstat(5, {st_mode=S_IFREG|0644, st_size=247, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc1251c2000
lseek(5, 0, SEEK_CUR)                   = 0
read(5, "#!/usr/bin/env python3\n\nimport s"..., 4096) = 247
close(5)                                = 0
munmap(0x7fc1251c2000, 4096)            = 0
lseek(4, 0, SEEK_SET)                   = 0
lseek(4, 0, SEEK_CUR)                   = 0
read(4, "#!/usr/bin/env python3\n\nimport s"..., 4096) = 247
close(4)                                = 0
write(2, "Traceback (most recent call last"..., 143Traceback (most recent call last):
  File "test.py", line 11, in <module>
    s.send(packet)
socket.error: [Errno 6] No such device or address
) = 143
rt_sigaction(SIGINT, {SIG_DFL, [], SA_RESTORER, 0x7fc1264050a0}, {0x428787, [], SA_RESTORER, 0x7fc1264050a0}, 8) = 0
close(3)                                = 0

Answer 1

当你在一个接口(interface)上绑定(bind)一个带有家族 PACKET 的 RAW 套接字时，你需要一个包含 2 个对象的元组:

(interfaceName, protoNumber)

或 5 个对象:

(interfaceName, protoNumber, pkttype, hatype, haddr)

您在 protoNumber 中指定了 0，但您的系统中可能不存在 protoNumber 0。

Documentation about packet family: packet(7)

sll_protocol is the standard ethernet protocol type in network byte order as defined in the include file.

尝试在 linux/if_ether.h 中找到正确的协议(protocol)号。