python socket检测端口及ping检测

python根据socket模块检测端口及vip

#!/usr/bin/env python
# -*- coding: utf8 -*-

from .ping_helper import Pinger
import socket

def check_port(ip, port):
    '''socket检测端口连通性'''
    if not port:
        return True
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.settimeout(3)
    try:
        s.connect((ip, int(port)))
        s.shutdown(socket.SHUT_RDWR)
        return True
    except:
        return False

def check_vip(target_host):
    '''检测vip是否可以ping通'''
    pinger = Pinger(target_host=target_host)
    try:
        delay = pinger.ping_once()
        status = True
        if delay == None:
            status = False
    except socket.gaierror as e:
        status = False
    return status

#!/usr/bin/env python
# -*- coding: utf8 -*-
import socket, os,struct,select,time

ICMP_ECHO_REQUEST = 8 # Platform specific
DEFAULT_TIMEOUT = 2
DEFAULT_COUNT = 4

class Pinger(object):
    """ Pings to a host -- the Pythonic way"""

    def __init__(self, target_host, count=DEFAULT_COUNT, timeout=DEFAULT_TIMEOUT):
        self.target_host = target_host
        self.count = count
        self.timeout = timeout

    def do_checksum(self, source_string):
        """  Verify the packet integritity """
        sum = 0
        max_count = (len(source_string)/2)*2
        count = 0
        while count < max_count:

            val = source_string[count + 1]*256 + source_string[count]
            sum = sum + val
            sum = sum & 0xffffffff
            count = count + 2

        if max_count<len(source_string):
            sum = sum + ord(source_string[len(source_string) - 1])
            sum = sum & 0xffffffff

        sum = (sum >> 16)  +  (sum & 0xffff)
        sum = sum + (sum >> 16)
        answer = ~sum
        answer = answer & 0xffff
        answer = answer >> 8 | (answer << 8 & 0xff00)
        return answer

    def receive_pong(self, sock, ID, timeout):
        """
        Receive ping from the socket.
        """
        time_remaining = timeout
        while True:
            start_time = time.time()
            readable = select.select([sock], [], [], time_remaining)
            time_spent = (time.time() - start_time)
            if readable[0] == []: # Timeout
                return

            time_received = time.time()
            recv_packet, addr = sock.recvfrom(1024)
            icmp_header = recv_packet[20:28]
            type, code, checksum, packet_ID, sequence = struct.unpack(
       "bbHHh", icmp_header
   )
            if packet_ID == ID:
                bytes_In_double = struct.calcsize("d")
                time_sent = struct.unpack("d", recv_packet[28:28 + bytes_In_double])[0]
                return time_received - time_sent

            time_remaining = time_remaining - time_spent
            if time_remaining <= 0:
                return

    def send_ping(self, sock,  ID):
        """
        Send ping to the target host
        """
        target_addr  =  socket.gethostbyname(self.target_host)

        my_checksum = 0

        # Create a dummy heder with a 0 checksum.
        header = struct.pack("bbHHh", ICMP_ECHO_REQUEST, 0, my_checksum, ID, 1)
        bytes_In_double = struct.calcsize("d")
        data = (192 - bytes_In_double) * "Q"
        data = struct.pack("d", time.time()) + bytes(data.encode('utf-8'))

        # Get the checksum on the data and the dummy header.
        my_checksum = self.do_checksum(header + data)
        header = struct.pack(
      "bbHHh", ICMP_ECHO_REQUEST, 0, socket.htons(my_checksum), ID, 1
  )
        packet = header + data
        sock.sendto(packet, (target_addr, 1))

    def ping_once(self):
        """
        Returns the delay (in seconds) or none on timeout.
        """
        icmp = socket.getprotobyname("icmp")
        try:
            sock = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)
        except socket.error as e:
            if e.errno == 1:
                # Not superuser, so operation not permitted
                e.msg +=  "ICMP messages can only be sent from root user processes"
                raise socket.error(e.msg)
        except Exception as e:
            print ("Exception: %s" %(e))

        my_ID = os.getpid() & 0xFFFF

        self.send_ping(sock, my_ID)
        delay = self.receive_pong(sock, my_ID, self.timeout)
        sock.close()
        return delay

    def ping(self):
        """
        Run the ping process
        """
        for i in range(self.count):
            try:
                delay  =  self.ping_once()
            except socket.gaierror as e:
                print ("Ping failed. (socket error: '%s')" % e[1])
                break

            if delay  ==  None:
                print ("Ping failed. (timeout within %ssec.)" % self.timeout)
            else:
                delay  =  delay * 1000
                print ("Get pong in %0.4fms" % delay)

注意

'''
使用使用shutdown来关闭socket的功能
SHUT_RDWR:关闭读写,即不可以使用send/write/recv/read
SHUT_RD:关闭读,即不可以使用recv/read
SHUT_WR:关闭写,即不可以使用send/write
'''
import socket

s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
s.connect(("localhost",50000))
s.sendall("this is shutdown test" + "\r\n")
s.send("this is shutdown test")
s.shutdown(socket.SHUT_RDWR)
print(socket.SHUT_RDWR)
print(socket.SHUT_RD)
print(socket.SHUT_WR)
s.close()

close方法可以释放一个连接的资源，但是不是立即释放，如果想立即释放，那么在close之前使用shutdown方法

shut_rd() -------关闭接受消息通道

shut_wr()--------关闭发送消息通道

shut_rdwr()-------连个通道都关闭

使用：在close()之前加上shutdown(num)即可  [shut_rd(), shut_wr(), shut_rdwr()分别代表num 为0  1  2 ]