SDN实验---Ryu的应用开发（三）流量监控

一：实现流量监控

（一）流量监控原理

其中控制器向交换机周期下发获取统计消息，请求交换机消息------是主动下发过程

流速公式：是（t1时刻的流量-t0时刻的流量）/（t1-t0)

剩余带宽公式：链路总带宽-流速--------是这一个这一个,例如s2-s3（不是一条，例如：h1->s1->s2->s3->h2）的剩余带宽

路径有效带宽是只：这一整条路径中，按照最小的剩余带宽处理

二：代码实现

（一）代码框架

from ryu.app import simple_switch_13
from ryu.controller.handler import set_ev_cls
from ryu.controller import ofp_event
from ryu.controller.handler import MAIN_DISPATCHER,DEAD_DISPATCHER

class MyMonitor(simple_switch_13):    #simple_switch_13 is same as the last experiment which named self_learn_switch
    '''
    design a class to achvie managing the quantity of flow
    '''

    def __init__(self,*args,**kwargs):
        super(MyMonitor,self).__init__(*args,**kwargs)

    @set_ev_cls(ofp_event.EventOFPStateChange,[MAIN_DISPATCHER,DEAD_DISPATCHER])
    def _state_change_handler(self,ev):
        '''
        design a handler to get switch state transition condition
        '''
        pass

    def _monitor(self):
        '''
        design a monitor on timing system to request switch infomations about port and flow
        '''
        pass

    def _request_stats(self,datapath):
        '''
        the function is to send requery to datapath
        '''
        pass

    @set_ev_cls(ofp_event.EventOFPPortStatsReply,MAIN_DISPATCHER)
    def _port_stats_reply_handler(self,ev):
        '''
        monitor to require the port state, then this function is to get infomation for port`s info
        '''
        pass

    @set_ev_cls(ofp_event.EventOFPFlowStatsReply,MAIN_DISPATCHER)
    def _port_stats_reply_handler(self,ev):
        '''
        monitor to require the flow state, then this function is to get infomation for flow`s info
        '''
        pass

（二）推文：协程https://www.cnblogs.com/ssyfj/p/9030165.html

（三）全部代码实现

from operator import attrgetter

from ryu.app import simple_switch_13
from ryu.controller.handler import set_ev_cls
from ryu.controller import ofp_event
from ryu.controller.handler import MAIN_DISPATCHER,DEAD_DISPATCHER
from ryu.lib import hub

class MyMonitor(simple_switch_13.SimpleSwitch13):    #simple_switch_13 is same as the last experiment which named self_learn_switch
    '''
    design a class to achvie managing the quantity of flow
    '''

    def __init__(self,*args,**kwargs):
        super(MyMonitor,self).__init__(*args,**kwargs)
        self.datapaths = {}
        #use gevent to start monitor
        self.monitor_thread = hub.spawn(self._monitor)

    @set_ev_cls(ofp_event.EventOFPStateChange,[MAIN_DISPATCHER,DEAD_DISPATCHER])
    def _state_change_handler(self,ev):
        '''
        design a handler to get switch state transition condition
        '''
        #first get ofprocotol info
        datapath = ev.datapath
        ofproto = datapath.ofproto
        ofp_parser = datapath.ofproto_parser

        #judge datapath`s status to decide how to operate
        if datapath.state == MAIN_DISPATCHER:    #should save info to dictation
            if datapath.id not in self.datapaths:
                self.datapaths[datapath.id] = datapath
                self.logger.debug("Regist datapath: %16x",datapath.id)
        elif datapath.state == DEAD_DISPATCHER:    #should remove info from dictation
            if datapath.id in self.datapaths:
                del self.datapaths[datapath.id]
                self.logger.debug("Unregist datapath: %16x",datapath.id)

    def _monitor(self):
        '''
        design a monitor on timing system to request switch infomations about port and flow
        '''
        while True:    #initiatie to request port and flow info all the time
            for dp in self.datapaths.values():
                self._request_stats(dp)
            hub.sleep()    #pause to sleep to wait reply, and gave time to other gevent to request

    def _request_stats(self,datapath):
        '''
        the function is to send requery to datapath
        '''
        self.logger.debug("send stats reques to datapath: %16x for port and flow info",datapath.id)

        ofproto = datapath.ofproto
        parser = datapath.ofproto_parser

        req = parser.OFPFlowStatsRequest(datapath)
        datapath.send_msg(req)

        req = parser.OFPPortStatsRequest(datapath, , ofproto.OFPP_ANY)
        datapath.send_msg(req)

    @set_ev_cls(ofp_event.EventOFPPortStatsReply,MAIN_DISPATCHER)
    def _port_stats_reply_handler(self,ev):
        '''
        monitor to require the port state, then this function is to get infomation for port`s info
        print("6666666666port info:")
        print(ev.msg)
        print(dir(ev.msg))
        '''
        body = ev.msg.body
        self.logger.info('datapath             port     '
                        'rx_packets            tx_packets'
                        'rx_bytes            tx_bytes'
                        'rx_errors            tx_errors'
                        )
        self.logger.info('---------------    --------'
                        '--------    --------'
                        '--------    --------'
                        '--------    --------'
                        )
        for port_stat in sorted(body,key=attrgetter('port_no')):
                self.logger.info('%016x %8x %8d %8d %8d %8d %8d %8d',
                    ev.msg.datapath.id,port_stat.port_no,port_stat.rx_packets,port_stat.tx_packets,
                    port_stat.rx_bytes,port_stat.tx_bytes,port_stat.rx_errors,port_stat.tx_errors
                        )

    @set_ev_cls(ofp_event.EventOFPFlowStatsReply,MAIN_DISPATCHER)
    def _flow_stats_reply_handler(self,ev):
        '''
        monitor to require the flow state, then this function is to get infomation for flow`s info
        print("777777777flow info:")
        print(ev.msg)
        print(dir(ev.msg))
        '''
        body = ev.msg.body

        self.logger.info('datapath             '
                        'in_port            eth_src'
                        'out_port            eth_dst'
                        'packet_count        byte_count'
                        )
        self.logger.info('---------------    '
                        '----    -----------------'
                        '----    -----------------'
                        '---------    ---------'
                        )
        for flow_stat in sorted([flow for flow in body if flow.priority==],
                        key=lambda flow:(flow.match['in_port'],flow.match['eth_src'])):
                self.logger.info('%016x    %8x    %17s    %8x    %17s    %8d    %8d',
                    ev.msg.datapath.id,flow_stat.match['in_port'],flow_stat.match['eth_src'],
                    flow_stat.instructions[].actions[].port,flow_stat.match['eth_dst'],
                    flow_stat.packet_count,flow_stat.byte_count
                        )

补充：注意---每个事件的属性可能不同，需要我们进行Debug，例如上面就出现了ev.msg.body（之前hub实现中没有）

（四）代码讲解

1.class MyMonitor(simple_switch_13.SimpleSwitch13):

simple_switch_13.SimpleSwitch13是样例代码，其中实现了和我们上一次实验中，自学习交换机类似的功能
（稍微多了个关于交换机是否上传全部packet还是只上传buffer_id），所以我们直接继承，可以减少写代码时间

2.协程实现伪并发self.monitor_thread = hub.spawn(self._monitor)

    def __init__(self,*args,**kwargs):
        super(MyMonitor,self).__init__(*args,**kwargs)
        self.datapaths = {}
        #use gevent to start monitor
        self.monitor_thread = hub.spawn(self._monitor)

3.在协程中实现周期请求交换机信息

    def _monitor(self):
        '''
        design a monitor on timing system to request switch infomations about port and flow
        '''
        while True:    #initiatie to request port and flow info all the time
            for dp in self.datapaths.values():
                self._request_stats(dp)
            hub.sleep(5)    #pause to sleep to wait reply, and gave time to other gevent to request

4.主动下发消息，请求交换机信息OFPFlowStatsRequest------注意：我们这里请求两个（端口和协议信息），所以我们要使用两个函数来分别处理port和flow响应

    def _request_stats(self,datapath):
        '''
        the function is to send requery to datapath
        '''
        self.logger.debug("send stats reques to datapath: %16x for port and flow info",datapath.id)

        ofproto = datapath.ofproto
        parser = datapath.ofproto_parser

        req = parser.OFPFlowStatsRequest(datapath)
        datapath.send_msg(req)

        req = parser.OFPPortStatsRequest(datapath, 0, ofproto.OFPP_ANY)　　#可以向上面一样省略默认参数
        datapath.send_msg(req)

源码查看参数

@_set_stats_type(ofproto.OFPMP_FLOW, OFPFlowStats)
@_set_msg_type(ofproto.OFPT_MULTIPART_REQUEST)
class OFPFlowStatsRequest(OFPFlowStatsRequestBase):
    """
    Individual flow statistics request message

    The controller uses this message to query individual flow statistics.

    ================ ======================================================
    Attribute        Description
    ================ ======================================================
    flags            Zero or ``OFPMPF_REQ_MORE``
    table_id         ID of table to read
    out_port         Require matching entries to include this as an output
                     port
    out_group        Require matching entries to include this as an output
                     group
    cookie           Require matching entries to contain this cookie value
    cookie_mask      Mask used to restrict the cookie bits that must match
    match            Instance of ``OFPMatch``
    ================ ======================================================

    Example::

        def send_flow_stats_request(self, datapath):
            ofp = datapath.ofproto
            ofp_parser = datapath.ofproto_parser

            cookie = cookie_mask =
            match = ofp_parser.OFPMatch(in_port=)
            req = ofp_parser.OFPFlowStatsRequest(datapath, ,
                                                 ofp.OFPTT_ALL,
                                                 ofp.OFPP_ANY, ofp.OFPG_ANY,
                                                 cookie, cookie_mask,
                                                 match)
            datapath.send_msg(req)
    """

    def __init__(self, datapath, flags=0, table_id=ofproto.OFPTT_ALL,
                 out_port=ofproto.OFPP_ANY,
                 out_group=ofproto.OFPG_ANY,
                 cookie=0, cookie_mask=0, match=None, type_=None):

5.获取端口响应信息ofp_event.EventOFPPortStatsReply

    @set_ev_cls(ofp_event.EventOFPPortStatsReply,MAIN_DISPATCHER)
    def _port_stats_reply_handler(self,ev):
        '''
        monitor to require the port state, then this function is to get infomation for port`s info
        print("6666666666port info:")
        print(ev.msg)
        print(dir(ev.msg))
        '''
        body = ev.msg.body
        self.logger.info('datapath             port     '
                        'rx_packets            tx_packets'
                        'rx_bytes            tx_bytes'
                        'rx_errors            tx_errors'
                        )
        self.logger.info('---------------    --------'
                        '--------    --------'
                        '--------    --------'
                        '--------    --------'
                        )
        for port_stat in sorted(body,key=attrgetter('port_no')):
                self.logger.info('%016x %8x %8d %8d %8d %8d %8d %8d',
                    ev.msg.datapath.id,port_stat.port_no,port_stat.rx_packets,port_stat.tx_packets,
                    port_stat.rx_bytes,port_stat.tx_bytes,port_stat.rx_errors,port_stat.tx_errors
                        )

端口信息：《参考》

6666666666port info:
version=0x4,msg_type=0x13,msg_len=0x1d0,xid=0x8dcd9187,
OFPPortStatsReply(
    body=[
OFPPortStats(port_no=,rx_packets=,tx_packets=,rx_bytes=,tx_bytes=,rx_dropped=,tx_dropped=,rx_errors=,tx_errors=,rx_frame_err=,rx_over_err=,rx_crc_err=,collisions=,duration_sec=,duration_nsec=), OFPPortStats(port_no=,rx_packets=,tx_packets=,rx_bytes=,tx_bytes=,rx_dropped=,tx_dropped=,rx_errors=,tx_errors=,rx_frame_err=,rx_over_err=,rx_crc_err=,collisions=,duration_sec=,duration_nsec=), OFPPortStats(port_no=,rx_packets=,tx_packets=,rx_bytes=,tx_bytes=,rx_dropped=,tx_dropped=,rx_errors=,tx_errors=,rx_frame_err=,rx_over_err=,rx_crc_err=,collisions=,duration_sec=,duration_nsec=), OFPPortStats(port_no=,rx_packets=,tx_packets=,rx_bytes=,tx_bytes=,rx_dropped=,tx_dropped=,rx_errors=,tx_errors=,rx_frame_err=,rx_over_err=,rx_crc_err=,collisions=,duration_sec=,duration_nsec=)
]
,flags=,type=)

OFPPortStats(
port_no=,                ----------
rx_packets=,                    ----------
tx_packets=,                    ----------
rx_bytes=,                    ----------
tx_bytes=,                    ----------
rx_dropped=,
tx_dropped=,
rx_errors=,                    ----------
tx_errors=,                    ----------
rx_frame_err=,
rx_over_err=,
rx_crc_err=,
collisions=,
duration_sec=,
duration_nsec=)

['_STATS_MSG_TYPES', '_TYPE', '__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_base_attributes', '_class_prefixes', '_class_suffixes', '_decode_value', '_encode_value', '_get_decoder', '_get_default_decoder', '_get_default_encoder', '_get_encoder', '_get_type', '_is_class', '_opt_attributes', '_restore_args', '_serialize_body', '_serialize_header', '_serialize_pre', 'body', 'buf', 'cls_body_single_struct', 'cls_from_jsondict_key', 'cls_msg_type', 'cls_stats_body_cls', 'cls_stats_type',
'datapath'                    ----------
, 'flags', 'from_jsondict', 'msg_len', 'msg_type', 'obj_from_jsondict', 'parser', 'parser_stats', 'parser_stats_body', 'register_stats_type', 'serialize', 'set_buf', 'set_classes', 'set_headers', 'set_xid', 'stringify_attrs', 'to_jsondict', 'type', 'version', 'xid']

6.获取flow协议响应信息ofp_event.EventOFPFlowStatsReply

    @set_ev_cls(ofp_event.EventOFPFlowStatsReply,MAIN_DISPATCHER)
    def _flow_stats_reply_handler(self,ev):
        '''
        monitor to require the flow state, then this function is to get infomation for flow`s info
        print("777777777flow info:")
        print(ev.msg)
        print(dir(ev.msg))
        '''
        body = ev.msg.body

        self.logger.info('datapath             '
                        'in_port            eth_src'
                        'out_port            eth_dst'
                        'packet_count        byte_count'
                        )
        self.logger.info('---------------    '
                        '----    -----------------'
                        '----    -----------------'
                        '---------    ---------'
                        )
        for flow_stat in sorted([flow for flow in body if flow.priority==],
                        key=lambda flow:(flow.match['in_port'],flow.match['eth_src'])):
                self.logger.info('%016x    %8x    %17s    %8x    %17s    %8d    %8d',
                    ev.msg.datapath.id,flow_stat.match['in_port'],flow_stat.match['eth_src'],
                    flow_stat.instructions[].actions[].port,flow_stat.match['eth_dst'],
                    flow_stat.packet_count,flow_stat.byte_count
                        )

协议信息《参考》

777777777flow info:
version=0x4,msg_type=0x13,msg_len=0x200,xid=0x9e448a1a,
OFPFlowStatsReply(
    body=[
        OFPFlowStats(byte_count=,cookie=,duration_nsec=,duration_sec=,flags=,hard_timeout=,idle_timeout=,instructions=[OFPInstructionActions(actions=[OFPActionOutput(len=,max_len=,port=,type=)],len=,type=)],
        length=,match=OFPMatch(oxm_fields={'in_port': , 'eth_src': '8a:06:6a:2c:10:fc', 'eth_dst': '26:20:2f:85:5a:9a'}),packet_count=,priority=,table_id=),     OFPFlowStats(byte_count=,cookie=,duration_nsec=,duration_sec=,flags=,hard_timeout=,idle_timeout=,instructions=[OFPInstructionActions(actions=[OFPActionOutput(len=,max_len=,port=,type=)],len=,type=)],
        length=,match=OFPMatch(oxm_fields={'in_port': , 'eth_src': '26:20:2f:85:5a:9a', 'eth_dst': '8a:06:6a:2c:10:fc'}),packet_count=,priority=,table_id=), OFPFlowStats(byte_count=,cookie=,duration_nsec=,duration_sec=,flags=,hard_timeout=,idle_timeout=,instructions=[OFPInstructionActions(actions=[OFPActionOutput(len=,max_len=,port=,type=)],len=,type=)],
        length=,match=OFPMatch(oxm_fields={'in_port': , 'eth_src': 'ca:9e:a1:af:b9:5f', 'eth_dst': '26:20:2f:85:5a:9a'}),packet_count=,priority=,table_id=), OFPFlowStats(byte_count=,cookie=,duration_nsec=,duration_sec=,flags=,hard_timeout=,idle_timeout=,instructions=[OFPInstructionActions(actions=[OFPActionOutput(len=,max_len=,port=,type=)],len=,type=)]
        ,length=,match=OFPMatch(oxm_fields={'in_port': , 'eth_src': '26:20:2f:85:5a:9a', 'eth_dst': 'ca:9e:a1:af:b9:5f'}),packet_count=,priority=,table_id=), OFPFlowStats(byte_count=,cookie=,duration_nsec=,duration_sec=,flags=,hard_timeout=,idle_timeout=,instructions=[OFPInstructionActions(actions=[OFPActionOutput(len=,max_len=,port=,type=)],len=,type=)],
        length=,match=OFPMatch(oxm_fields={}),packet_count=,priority=,table_id=)
]
,flags=,type=)

OFPFlowStats(
byte_count=,                ----------
cookie=,
duration_nsec=,
duration_sec=,
flags=,
hard_timeout=,
idle_timeout=,
instructions=[
    OFPInstructionActions(
        actions=[
            OFPActionOutput(
                len=,
                max_len=,
                port=,        ----------
                type=)
            ],
            len=,
            type=
    )
],
length=,
match=OFPMatch(oxm_fields={
    'in_port': ,                 ----------
    'eth_src': '8a:06:6a:2c:10:fc',     ----------
    'eth_dst': '26:20:2f:85:5a:9a'        ----------
}),
packet_count=,                ----------
priority=,
table_id=
)

['_STATS_MSG_TYPES', '_TYPE', '__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_base_attributes', '_class_prefixes', '_class_suffixes', '_decode_value', '_encode_value', '_get_decoder', '_get_default_decoder', '_get_default_encoder', '_get_encoder', '_get_type', '_is_class', '_opt_attributes', '_restore_args', '_serialize_body', '_serialize_header', '_serialize_pre', 'body', 'buf', 'cls_body_single_struct', 'cls_from_jsondict_key', 'cls_msg_type', 'cls_stats_body_cls', 'cls_stats_type',
'datapath'                    ----------
, 'flags', 'from_jsondict', 'msg_len', 'msg_type', 'obj_from_jsondict', 'parser', 'parser_stats', 'parser_stats_body', 'register_stats_type', 'serialize', 'set_buf', 'set_classes', 'set_headers', 'set_xid', 'stringify_attrs', 'to_jsondict', 'type', 'version', 'xid']

三：实验演示

（一）开启Ryu

ryu-manager my_monitor.py

（二）开启Mininet

sudo mn --topo=tree,, --controller=remote --mac 

(三）Ryu显示结果

（四）还需要去了解返回的字段含义才可以---以后做，最近没时间了