path.py 文件源码

def get_next_hop(src_info, dst_info, qrouter, params):
    next_hop_list = []
    next_hop = None

    username = params['username']
    passwd = params['passwd']
    src_ip = src_info['ip']
    dst_ip = dst_info['ip']

    remote_cmd = ' ip route get %s' % dst_ip

    cmd = 'sudo ip netns exec ' + qrouter
    cmd += ' python run_nms_cmd.py --host_ip %s --username "%s" --passwd "%s" --cmd "%s" ' % \
        (src_ip, username, passwd, remote_cmd)

    output = run_remote_cmd(cmd)
    a = json.loads(output)

    if not a['pass']:
        return []

    json_file = params['json_file']
    info = load_json(json_file)

    next_hop = {}
    for cmd in a['command_list']:
        if re.search('ip route get', cmd['cmd']):
            m = re.search('\S+\s+via\s+(\S+)', cmd['output'][0])
            if m:
                next_hop['ip'] = m.group(1)
                next_hop['dev'] = 'qr-' + ip_to_intf(info, next_hop['ip'])
                next_hop['nms'] = intf_to_namespace(info, next_hop['dev'])
                break

    next_hop_list.append(next_hop)

    cmd = 'sudo ip netns exec ' + next_hop['nms']
    cmd += remote_cmd

    output = run_remote_cmd(cmd).split('\n')

    prev_nms = next_hop['nms']
    next_hop = {}
    m = re.search('\S+\s+dev\s+(\S+)', output[0])
    if m:
        next_hop['dev'] = m.group(1)
        next_hop['nms'] = prev_nms

    next_hop_list.append(next_hop)
    return next_hop_list