Re: [dts] [PATCH v4] framwork/packet: sniff_packet specify running target support

["Liu, Yong" <yong.liu@intel.com>]

Hi Phil,
I tried your patch set and met such issues. 

1. load_sniff_packet function will send signal to child process to stop sniff. But this method will not work with remote ssh. After received signal only ssh process is exited and meanwhile tcpdump process is still alive.

2. In v3 patch set, code for import packet module has been remove. That will cause some suites can't run.

Thanks,
Marvin

> -----Original Message-----
> From: Phil Yang [mailto:phil.yang@arm.com]
> Sent: Thursday, April 12, 2018 5:53 PM
> To: dts@dpdk.org
> Cc: nd@arm.com; Liu, Yong <yong.liu@intel.com>
> Subject: [PATCH v4] framwork/packet: sniff_packet specify running target
> support
> 
> If tester in crb file was not the machine which running dts,
> the sniff_packet process will not running on tester.
> 
> Create a ssh connection to the tester and run tcpdump to make sure
> sniff_packet process running on the machine we expected.
> 
> Removed load_sniff_packets function in packet module as it will be
> useless.
> 
> Signed-off-by: Phil Yang <phil.yang@arm.com>
> Suggested-by: Marvin Liu <yong.liu@intel.com>
> ---
>  framework/packet.py | 70 +++++++++++++++++++++---------------------------
> -----
>  framework/tester.py | 37 ++++++++++++++++++++++++++++
>  2 files changed, 65 insertions(+), 42 deletions(-)
> 
> diff --git a/framework/packet.py b/framework/packet.py
> index 976b82b..f99ead8 100755
> --- a/framework/packet.py
> +++ b/framework/packet.py
> @@ -812,15 +812,30 @@ 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)
> +
> +    # target[] contain the remote machine info for ssh connection
> +    # target[0]: username
> +    # target[1]: ip address
> +    # target[2]: pass word
> +    if target:
> +        tcpdump_help_pipe = subprocess.Popen(["ssh",
> +                            "%s@%s" % (target[0], target[1]),
> +                            "tcpdump -h"],
> +                            stderr=subprocess.PIPE,
> +                            stdout=subprocess.PIPE,
> +                            shell=False)
> +        tcpdump_help = "".join(tuple(tcpdump_help_pipe.communicate()))
> +        tcpdump_help_pipe.wait()
> +    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:
> @@ -850,9 +865,16 @@ def sniff_packets(intf, count=0, timeout=5,
> filters=[]):
>      else:
>          cmd = sniff_cmd % options
> 
> -    args = shlex.split(cmd)
> +    if target:
> +        pipe = subprocess.Popen(["ssh",
> +                "%s@%s" % (target[0], target[1]),
> +                cmd],
> +                stdin=subprocess.PIPE,
> +                shell=False)
> +    else:
> +        args = shlex.split(cmd)
> +        pipe = subprocess.Popen(args)
> 
> -    pipe = subprocess.Popen(args)
>      index = str(time.time())
>      SNIFF_PIDS[index] = (pipe, intf, timeout)
>      time.sleep(1)
> @@ -886,42 +908,6 @@ 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:
> diff --git a/framework/tester.py b/framework/tester.py
> index a775f68..c787b89 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
> @@ -704,6 +705,42 @@ 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")
> +        pcap = load_pcap_f(index)
> +        self.session.copy_file_from(pcap)
> +
> +        return pcap.split(os.sep)[-1]
> +
> +    def load_tcpdump_sniff_packets(self, index=''):
> +        """
> +        Wrapper for packet module load_sniff_packets
> +        """
> +        # 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