在Python中,是否有一种方法可以通过ICMP来ping服务器,如果服务器响应则返回TRUE,如果没有响应则返回FALSE ?
当前回答
在linux上,可以创建ICMP数据报(不是原始)套接字,而不需要root(或setuid或CAP_NET_RAW): https://unix.stackexchange.com/a/592914。最后我得到了
$ id
uid=1000(raylu) gid=1000(raylu) [...]
$ sudo sysctl net.ipv4.ping_group_range='1000 1000'
import socket
import struct
import time
def main():
ping('192.168.1.10')
def ping(destination):
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.getprotobyname('icmp'))
sock.settimeout(10.0)
start_time = time.time_ns() # python 3.7+ only
payload = struct.pack('L', start_time)
sock.sendto(encode(payload), (destination, 0))
while (time.time_ns() - start_time) // 1_000_000_000 < 10:
try:
data, source = sock.recvfrom(256)
except socket.timeout:
print('timed out')
return
message_type, message_code, check, identifier, sequence_number = struct.unpack('bbHHh', data[:8])
if source == (destination, 0) and message_type == ICMP.ECHO_REPLY and data[8:] == payload:
print((time.time_ns() - start_time) // 1_000_000, 'ms')
break
else:
print('got unexpected packet from %s:' % source[0], message_type, data[8:])
else:
print('timed out')
def encode(payload: bytes):
# calculate checksum with check set to 0
checksum = calc_checksum(icmp_header(ICMP.ECHO_REQUEST, 0, 0, 1, 1) + payload)
# craft the packet again with the checksum set
return icmp_header(ICMP.ECHO_REQUEST, 0, checksum, 1, 1) + payload
def icmp_header(message_type, message_code, check, identifier, sequence_number) -> bytes:
return struct.pack('bbHHh', message_type, message_code, check, identifier, sequence_number)
def calc_checksum(data: bytes) -> int:
'''RFC 1071'''
# code stolen from https://github.com/alessandromaggio/pythonping/blob/a59ce65a/pythonping/icmp.py#L8
'''
MIT License
Copyright (c) 2018 Alessandro Maggio
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
'''
subtotal = 0
for i in range(0, len(data)-1, 2):
subtotal += (data[i] << 8) + data[i+1]
if len(data) % 2:
subtotal += (data[len(data)-1] << 8)
while subtotal >> 16:
subtotal = (subtotal & 0xFFFF) + (subtotal >> 16)
check = ~subtotal
return ((check << 8) & 0xFF00) | ((check >> 8) & 0x00FF)
class ICMP:
ECHO_REPLY = 0
ECHO_REQUEST = 8
虽然这里其他答案建议的许多软件包也可以工作
其他回答
我自己的方法结合了上面的几个答案:
def ping(host, show_log=False, package_count=1):
ping.param = "-n" if platform.system().lower() == 'windows' else "-c"
result = subprocess.run(['ping', ping.param, str(package_count), host],
stdout=subprocess.PIPE,
stderr=subprocess.STDOUT)
output = result.stdout
if show_log:
print('return code: ', result.returncode)
print(output.decode("utf-8"))
return result.returncode == 0 and (b'TTL=' in output or b'ttl=' in output)
在OSX Monterey上测试。
很多答案都忽略了一点(至少在Windows中),如果ping命令收到“目标主机不可达”的回复,它将返回0(表示成功)。
下面是我的代码,它检查b' ttl ='是否在响应中,因为它只在ping到达主机时才出现。注意:此代码的大部分是基于这里的其他答案。
import platform
import subprocess
def ping(ipAddr, timeout=100):
'''
Send a ping packet to the specified host, using the system ping command.
Accepts ipAddr as string for the ping destination.
Accepts timeout in ms for the ping timeout.
Returns True if ping succeeds otherwise Returns False.
Ping succeeds if it returns 0 and the output includes b'TTL='
'''
if platform.system().lower() == 'windows':
numFlag = '-n'
else:
numFlag = '-c'
completedPing = subprocess.run(['ping', numFlag, '1', '-w', str(timeout), ipAddr],
stdout=subprocess.PIPE, # Capture standard out
stderr=subprocess.STDOUT) # Capture standard error
# print(completedPing.stdout)
return (completedPing.returncode == 0) and (b'TTL=' in completedPing.stdout)
print(ping('google.com'))
注意:这将捕获输出而不是打印输出,因此如果您希望看到ping的输出,则需要打印completedPing。返回前的Stdout。
如果您的服务器不支持ICMP(防火墙可能会阻止它),它很可能仍然在TCP端口上提供服务。在这种情况下,你可以像这样执行TCP ping1(平台独立,无需安装额外的python模块):
import socket
def isReachable(ipOrName, port, timeout=2):
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(timeout)
try:
s.connect((ipOrName, int(port)))
s.shutdown(socket.SHUT_RDWR)
return True
except:
return False
finally:
s.close()
代码从这里开始只做了轻微的修改。
1 TCP ping并不真正存在,因为ping是在ISO/OSI第三层用ICMP执行的。TCP ping在ISO/OSI第4层执行。它只是试图以最基本的方式连接到TCP端口,即不传输任何数据,而是在连接后立即关闭连接。
看起来很简单,但却让我头疼。我一直得到“icmp打开套接字操作不允许”,否则解决方案将挂起,如果服务器离线。然而,如果你想知道的是服务器是活的,并且你在该服务器上运行一个web服务器,那么curl将完成这项工作。如果您有ssh和证书,那么ssh和一个简单的命令就足够了。代码如下:
from easyprocess import EasyProcess # as root: pip install EasyProcess
def ping(ip):
ping="ssh %s date;exit"%(ip) # test ssh alive or
ping="curl -IL %s"%(ip) # test if http alive
response=len(EasyProcess(ping).call(timeout=2).stdout)
return response #integer 0 if no response in 2 seconds
我有类似的要求,所以我实现它如下所示。它在Windows 64位和Linux上进行了测试。
import subprocess
def systemCommand(Command):
Output = ""
Error = ""
try:
Output = subprocess.check_output(Command,stderr = subprocess.STDOUT,shell='True')
except subprocess.CalledProcessError as e:
#Invalid command raises this exception
Error = e.output
if Output:
Stdout = Output.split("\n")
else:
Stdout = []
if Error:
Stderr = Error.split("\n")
else:
Stderr = []
return (Stdout,Stderr)
#in main
Host = "ip to ping"
NoOfPackets = 2
Timeout = 5000 #in milliseconds
#Command for windows
Command = 'ping -n {0} -w {1} {2}'.format(NoOfPackets,Timeout,Host)
#Command for linux
#Command = 'ping -c {0} -w {1} {2}'.format(NoOfPackets,Timeout,Host)
Stdout,Stderr = systemCommand(Command)
if Stdout:
print("Host [{}] is reachable.".format(Host))
else:
print("Host [{}] is unreachable.".format(Host))
当IP不可达时,subprocess.check_output()将引发异常。额外的验证可以通过从输出行“Packets: Sent = 2, Received = 2, Lost = 0 (0% loss)”中提取信息来完成。
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