Re: [dts] [PATCH v6 01/22] framework/packet: support packet sniffer to specify running machine

["Tu, Lijuan" <lijuan.tu@intel.com>]

Hi Phil,
Poll is an attribute of Popen, but not pxssh.

To make sniff function more clear, I prefer to remove the old code instead of keeping them.
As in dts, we always pass the parameter target, the tester information, we could raise exception when finding target is None.

> -----Original Message-----
> From: phil.yang@arm.com [mailto:phil.yang@arm.com]
> Sent: Tuesday, October 16, 2018 2:20 PM
> To: dts@dpdk.org
> Cc: nd@arm.com; Tu, Lijuan <lijuan.tu@intel.com>
> Subject: [PATCH v6 01/22] framework/packet: support packet sniffer to
> specify running machine
> 
> By default, the Tester is supposed to be the server which running DTS and the
> packet sniff methods are running on it.
> However, if DTS was not running on the Tester and the Tester is another
> remote server, so packet sniff methods cannot sniff Tester's packets
> correctly.
> 
> This patch adds support for packet sniff methods to specify running machine
> and implements sniff packet methods in class tester.
> 
> 1. Add parameter to sniff_packet and load_sniff_pcap methods to specify
> the running machine.
> 2. Remove load_sniff_packets method in packet.py.
> 3. Add tcpdump_sniff_packets, load_tcpdump_sniff_pcap and
> load_tcpdump_sniff_packets for class tester with the new sniff_packet API.
> 4. Update tester.check_random_pkts method with
> tester.tcpdump_sniff_packets and tester.load_tcpdump_sniff_packets to
> make it execution on the Tester.
> 
> Signed-off-by: Phil Yang <phil.yang@arm.com>
> Suggested-by: Marvin Liu <yong.liu@intel.com>
> Suggested-by: Tu Lijuan <lijuan.tu@intel.com>
> ---
>  framework/packet.py | 100
> +++++++++++++++++++++++++++-------------------------
>  framework/tester.py |  48 ++++++++++++++++++++++---
>  2 files changed, 95 insertions(+), 53 deletions(-)
> 
> diff --git a/framework/packet.py b/framework/packet.py index
> 976b82b..517c93d 100755
> --- a/framework/packet.py
> +++ b/framework/packet.py
> @@ -33,7 +33,6 @@
>  Generic packet create, transmit and analyze module  Base on
> scapy(python program for packet manipulation)  """
> -
>  import os
>  import time
>  import sys
> @@ -61,6 +60,7 @@ from scapy.route import *  from scapy.packet import
> bind_layers, Raw  from scapy.sendrecv import sendp  from scapy.arch
> import get_if_hwaddr
> +from pexpect import pxssh
> 
>  # load extension layers
>  exec_file = os.path.realpath(__file__)
> @@ -812,15 +812,31 @@ def get_filter_cmd(filters=[]):
>          return ""
> 
> 
> -def sniff_packets(intf, count=0, timeout=5, filters=[]):
> +def sniff_packets(intf, count=0, timeout=5, filters=[], target=[]):
>      """
>      sniff all packets for certain port in certain seconds
>      """
>      param = ""
>      direct_param = r"(\s+)\[ (\S+) in\|out\|inout \]"
> -    tcpdump_help = subprocess.check_output("tcpdump -h; echo 0",
> -
> stderr=subprocess.STDOUT,
> -                                           shell=True)
> +    remote_terminate = 0 # session remote terminate flag
> +
> +    # target[] contain the remote machine info for ssh connection
> +    # target[0]: username
> +    # target[1]: ip address
> +    # target[2]: pass word
> +    if target:
> +	tcpdump_help_session=pxssh.pxssh()
> +	tcpdump_help_session.login(server=target[1], username=target[0],
> +                                   password=target[2],
> original_prompt='[$#>]',
> +                                   login_timeout=20)
> +	tcpdump_help_session.sendline('tcpdump -h')
> +	tcpdump_help_session.prompt()
> +	tcpdump_help=tcpdump_help_session.before
> +	tcpdump_help_session.logout()
> +    else:
> +        tcpdump_help = subprocess.check_output("tcpdump -h; echo 0",
> +                                    stderr=subprocess.STDOUT,
> +shell=True)
> +
>      for line in tcpdump_help.split('\n'):
>          m = re.match(direct_param, line)
>          if m:
> @@ -850,22 +866,31 @@ def sniff_packets(intf, count=0, timeout=5,
> filters=[]):
>      else:
>          cmd = sniff_cmd % options
> 
> -    args = shlex.split(cmd)
> +    if target:
> +        tcpdump_session=pxssh.pxssh()
> +        tcpdump_session.login(server=target[1], username=target[0],
> +                              password=target[2],
> original_prompt='[$#>]',
> +                              login_timeout=20)
> +        tcpdump_session.sendline(cmd)
> +        pipe = tcpdump_session
> +        remote_terminate = 1
> +    else:
> +        args = shlex.split(cmd)
> +        pipe = subprocess.Popen(args)
> 
> -    pipe = subprocess.Popen(args)
>      index = str(time.time())
> -    SNIFF_PIDS[index] = (pipe, intf, timeout)
> +    SNIFF_PIDS[index] = (pipe, intf, timeout, remote_terminate)
>      time.sleep(1)
>      return index
> 
> 
> -def load_sniff_pcap(index=''):
> +def load_sniff_pcap(index='', target=[]):
>      """
>      Stop sniffer and return pcap file
>      """
>      child_exit = False
>      if index in SNIFF_PIDS.keys():
> -        pipe, intf, timeout = SNIFF_PIDS[index]
> +        pipe, intf, timeout, remote_terminate = SNIFF_PIDS[index]
>          time_elapse = int(time.time() - float(index))
>          while time_elapse < timeout:
>              if pipe.poll() is not None:
[Lijuan] Exception happened here because poll is not an attribute of pxssh.
> @@ -876,8 +901,22 @@ def load_sniff_pcap(index=''):
>              time_elapse += 1
> 
>          if not child_exit:
> -            pipe.send_signal(signal.SIGINT)
> -            pipe.wait()
> +            if remote_terminate == 1:
> +                tcpdump_quit_session=pxssh.pxssh()
> +                tcpdump_quit_session.login(server=target[1],
> username=target[0],
> +                                           password=target[2],
> original_prompt='[$#>]',
> +                                           login_timeout=20)
> +                tcpdump_quit_session.sendline('kill -2 $(pidof
> tcpdump)')
> +                tcpdump_quit_session.prompt()
> +                tcpdump_quit_session.logout()
> +                # Teminate the tcpdump_session
> +                pipe.prompt()
> +                pipe.logout()
> +                pipe = None
> +
> +            if pipe is not None:
> +                pipe.send_signal(signal.SIGINT)
> +                pipe.wait()
> 
>          # wait pcap file ready
>          time.sleep(1)
> @@ -886,42 +925,6 @@ def load_sniff_pcap(index=''):
>      return ""
> 
> 
> -def load_sniff_packets(index=''):
> -    """
> -    Stop sniffer and return packet objects
> -    """
> -    pkts = []
> -    child_exit = False
> -    if index in SNIFF_PIDS.keys():
> -        pipe, intf, timeout = SNIFF_PIDS[index]
> -        time_elapse = int(time.time() - float(index))
> -        while time_elapse < timeout:
> -            if pipe.poll() is not None:
> -                child_exit = True
> -                break
> -
> -            time.sleep(1)
> -            time_elapse += 1
> -
> -        if not child_exit:
> -            pipe.send_signal(signal.SIGINT)
> -            pipe.wait()
> -
> -        # wait pcap file ready
> -        time.sleep(1)
> -        try:
> -            cap_pkts = rdpcap("/tmp/sniff_%s.pcap" % intf)
> -            for pkt in cap_pkts:
> -                # packet gen should be scapy
> -                packet = Packet(tx_port=intf)
> -                packet.pktgen.assign_pkt(pkt)
> -                pkts.append(packet)
> -        except:
> -            pass
> -
> -    return pkts
> -
> -
>  def load_pcapfile(filename=""):
>      pkts = []
>      try:
> @@ -983,7 +986,6 @@ if __name__ == "__main__":
>      inst = sniff_packets("lo", timeout=5)
>      pkt = Packet(pkt_type='UDP')
>      pkt.send_pkt(tx_port='lo')
> -    pkts = load_sniff_packets(inst)
> 
>      pkt = Packet(pkt_type='UDP', pkt_len=1500, ran_payload=True)
>      pkt.send_pkt(tx_port='lo')
> diff --git a/framework/tester.py b/framework/tester.py index
> a775f68..c5b705d 100755
> --- a/framework/tester.py
> +++ b/framework/tester.py
> @@ -35,6 +35,7 @@ Interface for bulk traffic generators.
> 
>  import re
>  import subprocess
> +import os
>  from time import sleep
>  from settings import NICS, load_global_setting, PERF_SETTING  from crb
> import Crb @@ -560,8 +561,6 @@ class Tester(Crb):
>          module = __import__("packet")
>          pkt_c = getattr(module, "Packet")
>          send_f = getattr(module, "send_packets")
> -        sniff_f = getattr(module, "sniff_packets")
> -        load_f = getattr(module, "load_sniff_packets")
>          compare_f = getattr(module, "compare_pktload")
>          strip_f = getattr(module, "strip_pktload")
>          save_f = getattr(module, "save_packets") @@ -606,7 +605,7 @@
> class Tester(Crb):
> 
>              # send and sniff packets
>              save_f(pkts=pkts, filename="/tmp/%s_tx.pcap" % txIntf)
> -            inst = sniff_f(intf=rxIntf, count=pktnum, timeout=timeout,
> filters=
> +            inst = self.tcpdump_sniff_packets(intf=rxIntf,
> + count=pktnum, timeout=timeout, filters=
>                  [{'layer': 'network', 'config': {'srcport': '65535'}},
>                   {'layer': 'network', 'config': {'dstport': '65535'}}])
>              rx_inst[rxport] = inst
> @@ -627,7 +626,7 @@ class Tester(Crb):
>          # Verify all packets
>          prev_id = -1
>          for txport, rxport in portList:
> -            recv_pkts = load_f(rx_inst[rxport])
> +            recv_pkts =
> + self.load_tcpdump_sniff_packets(rx_inst[rxport])
> 
>              # only report when recevied number not matched
>              if len(tx_pkts[txport]) > len(recv_pkts):
> @@ -704,6 +703,47 @@ class Tester(Crb):
>              self.proc.kill()
>              self.proc = None
> 
> +    def tcpdump_sniff_packets(self, intf, count=0, timeout=5, filters=[]):
> +        """
> +        Wrapper for packet module sniff_packets
> +        """
> +        # load functions in packet module
> +        module = __import__("packet")
> +        sniff_f = getattr(module, "sniff_packets")
> +
> +        target=[]
> +        target.append(self.get_username())
> +        target.append(self.get_ip_address())
> +        target.append(self.get_password())
> +        return sniff_f(intf, count, timeout, filters, target)
> +
> +    def load_tcpdump_sniff_pcap(self, index=''):
> +        """
> +        Wrapper for packet module load_sniff_pcap
> +        """
> +        # load functions in packet module
> +        module = __import__("packet")
> +        load_pcap_f = getattr(module, "load_sniff_pcap")
> +
> +        target=[]
> +        target.append(self.get_username())
> +        target.append(self.get_ip_address())
> +        target.append(self.get_password())
> +        pcap = load_pcap_f(index, target)
> +        self.session.copy_file_from(pcap)
> +
> +        return pcap.split(os.sep)[-1]
> +
> +    def load_tcpdump_sniff_packets(self, index=''):
> +        """
> +        Wrapper for packet module load_pcapfile
> +        """
> +        # load functions in packet module
> +        packet = __import__("packet")
> +        file = self.load_tcpdump_sniff_pcap(index)
> +
> +        return packet.load_pcapfile(file)
> +
>      def kill_all(self, killall=False):
>          """
>          Kill all scapy process or DPDK application on tester.
> --
> 2.7.4