如何在python中检查网络接口上的数据传输？

Question

有一种socket方法可以获取给定网络接口的IP:

import socket
import fcntl
import struct

def get_ip_address(ifname):
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    return socket.inet_ntoa(fcntl.ioctl(
        s.fileno(),
        0x8915,  # SIOCGIFADDR
        struct.pack('256s', ifname[:15])
    )[20:24])

返回以下内容:

>>> get_ip_address('lo')
'127.0.0.1'

>>> get_ip_address('eth0')
'38.113.228.130'

是否有类似的方法来返回该接口的网络传输？我知道我可以阅读,/proc/net/dev但我喜欢套接字方法.

Answer 1

轮询以太网接口统计信息的最佳方法是通过SNMP ...

• 看起来你正在使用linux ...如果是这样,请加载你snmpd的这些选项...安装后snmpd,在你的/ etc/defaults/snmpd中(确保行SNMPDOPTS看起来像这样):

  SNMPDOPTS='-Lsd -Lf /dev/null -u snmp -I -smux,usmConf,iquery,dlmod,diskio,lmSensors,hr_network,snmpEngine,system_mib,at,interface,ifTable,ipAddressTable,ifXTable,ip,cpu,tcpTable,udpTable,ipSystemStatsTable,ip,snmp_mib,tcp,icmp,udp,proc,memory,snmpNotifyTable,inetNetToMediaTable,ipSystemStatsTable,disk -Lsd -p /var/run/snmpd.pid'

• 您可能还需要将ro社区更改为public ^{请参阅注释1}并设置您的侦听接口/etc/snmp/snmpd.conf(如果不是环回)...

• 假设您有一个功能snmpd,此时,您可以使用此方法轮询ifHCInBytes并ifHCOutBytes ^查看有关您的接口的^注释2 ...

poll_bytes.py:

from SNMP import v2Manager
import time

def poll_eth0(manager=None):
    # NOTE: 2nd arg to get_index should be a valid ifName value
    in_bytes = manager.get_index('ifHCInOctets', 'eth0')
    out_bytes = manager.get_index('ifHCOutOctets', 'eth0')
    return (time.time(), int(in_bytes), int(out_bytes))

# Prep an SNMP manager object...
mgr = v2Manager('localhost')
mgr.index('ifName')
stats = list()
# Insert condition below, instead of True...
while True:
    stats.append(poll_eth0(mgr))
    print poll_eth0(mgr)
    time.sleep(5)

SNMP.py:

from subprocess import Popen, PIPE
import re

class v2Manager(object):
    def __init__(self, addr='127.0.0.1', community='public'):
        self.addr      = addr
        self.community = community
        self._index = dict()

    def bulkwalk(self, oid='ifName'):
        cmd = 'snmpbulkwalk -v 2c -Osq -c %s %s %s' % (self.community,
            self.addr, oid)
        po = Popen(cmd, shell=True, stdout=PIPE, executable='/bin/bash')
        output = po.communicate()[0]
        result = dict()
        for line in re.split(r'\r*\n', output):
            if line.strip()=="":
                continue
            idx, value = re.split(r'\s+', line, 1)
            idx = idx.replace(oid+".", '')
            result[idx] = value
        return result

    def bulkwalk_index(self, oid='ifOutOctets'):
        result = dict()
        if not (self._index==dict()):
            vals = self.bulkwalk(oid=oid)
            for key, val in vals.items():
                idx = self._index.get(key, None)
                if not (idx is None):
                    result[idx] = val
                else:
                    raise ValueError, "Could not find '%s' in the index (%s)" % self.index
        else:
            raise ValueError, "Call the index() method before calling bulkwalk_index()"
        return result

    def get_index(self, oid='ifOutOctets', index=''):
        # This method is horribly inefficient... improvement left as exercise for the reader...
        if index:
            return self.bulkwalk_index().get(index, "<unknown>")
        else:
            raise ValueError, "Please include an index to get"

    def index(self, oid='ifName'):
        self._index = self.bulkwalk(oid=oid)

结束说明:

1. SNMP v2c使用明文身份验证.如果您担心安全性/有人嗅探您的流量,请更改您的社区并通过源IP地址限制查询到您的Linux机器.完美的世界将是修改SNMP.py上述使用SNMPv3(加密敏感数据); 大多数人只使用非公共社区并通过源IP限制snmp查询.

2. ifHCInOctets并ifHCOutOctets为通过接口传输的字节数提供瞬时值.如果您正在寻找数据传输速率,当然会涉及一些额外的数学.