我正在用Python3编写traceroute作为练习。它工作得很好，但是跟踪有时会无法从某个跃点接收到应答，并且无法在没有得到响应的情况下继续增加TTL。常规的Linux traceroute程序不会遇到此问题，因此它必须在我的代码中。
我尝试了不同的变体，但是它们都遇到相同的问题。我将在8.8.8.8上运行跟踪，并在5次中运行4次，它运行良好。
我尝试使用上下文管理器（套接字为...）创建套接字，也尝试手动创建套接字。
import os
import random
import socket
import sys
import time
class Traceroute:
def __init__(self, dest, maxhops=30, port=random.randrange(33434,33534), host=''):
self.dest = dest
self.maxhops = maxhops
self.port = port
self.host = host
self.hops = []
# Function for creating new sockets
def get_socket(self,type,proto=0):
s = socket.socket(
family=socket.AF_INET,
type=type,
proto=proto
)
s.bind((self.host,self.port))
return s
# Do the trace and store hop information for later use
def get_path(self):
try:
self.dest_ip = socket.gethostbyname(self.dest)
self.dest_name = socket.gethostbyaddr(self.dest)[0]
except socket.gaierror as e:
print(f'Error: {self.dest} - {e}')
address = ['']
ttl = 1
while ttl < self.maxhops +1 and address[0] != self.dest_ip:
receiver_socket = self.get_socket(socket.SOCK_RAW,socket.getprotobyname('icmp'))
receiver_socket.settimeout(2)
sender_socket = self.get_socket(socket.SOCK_DGRAM,socket.getprotobyname('udp'))
sender_socket.setsockopt(socket.SOL_IP,socket.IP_TTL,ttl)
sender_socket.sendto(b'',(self.dest_ip,self.port))
tries = 3
while tries > 0:
starttime = time.time()
try:
data, address = receiver_socket.recvfrom(1024)
latency = [round((time.time()-starttime)*1000,2)]
try:
hostname = socket.gethostbyaddr(address[0])[0]
except socket.herror as e:
hostname = address[0]
self.hops.append({
'address':address[0],
'hostname':hostname,
'latency': latency
})
tries = 0
except socket.error:
tries -= 1
if tries == 0:
self.hops.append({
'address':None,
'hostname':ttl,
'latency':None
})
finally:
receiver_socket.close()
sender_socket.close()
ttl += 1
os.system('clear')
self.draw()
def draw(self):
name = f'{self.dest_ip} - {self.dest_name}' if self.dest_name != self.dest_ip else self.dest_ip
print(f'Traceroute to {name}')
# Print the full hop list, for debugging
for hop in self.hops:
print(hop)
# Print the hops in a readable fashion
for hop in self.hops:
if hop['address'] is None:
print(f"{self.hops.index(hop)+1} - {'*':<50} - {'*':<50} - {'*':<50}")
else:
latencylen = len(hop['latency'])
latencyavg = str(round(sum(hop['latency'])/latencylen,2)) + 'ms'
name = f'{hop["address"]} - {hop["hostname"]}' if hop['address'] != hop['hostname'] else hop['address']
print(f'{self.hops.index(hop)+1} - {name:<50} - {latencyavg:<50} - LEN:{latencylen:<50}')
def main():
if len(sys.argv) < 2:
print('Please enter a destination')
else:
trace = Traceroute(sys.argv[1])
trace.get_path()
if __name__ == '__main__':
main()
这是完全错误的输出：
self.hops是词典列表。
{brackets}中的内容是跳字典本身。我添加它用于调试。 请注意，跃点2和3相同。因此，踪迹不知何故遇到了此跃点两次。该行开头的数字是列表索引，它也表示TTL。我通常会在第9跳之前达到8.8.8.8，但在这种情况下，它会一直保持下去，将TTL递增直到达到最大值。
Traceroute to 8.8.8.8 - google-public-dns-a.google.com
{'address': '192.168.1.1', 'hostname': '_gateway', 'latency': [8.21]}
{'address': '104.195.128.122', 'hostname': '104-195-128-122.cpe.teksavvy.com', 'latency': [1572.38]}
{'address': '104.195.128.122', 'hostname': '104-195-128-122.cpe.teksavvy.com', 'latency': [15.97]}
{'address': '104.195.129.9', 'hostname': '104-195-129-9.cpe.teksavvy.com', 'latency': [27.22]}
{'address': '206.248.155.92', 'hostname': 'ae10-0-bdr01-tor2.teksavvy.com', 'latency': [20.05]}
{'address': '206.248.155.10', 'hostname': 'ae12-0-bdr01-tor.teksavvy.com', 'latency': [27.2]}
{'address': None, 'hostname': 7, 'latency': None}
{'address': None, 'hostname': 8, 'latency': None}
{'address': None, 'hostname': 9, 'latency': None}
{'address': None, 'hostname': 10, 'latency': None}
{'address': None, 'hostname': 11, 'latency': None}
{'address': None, 'hostname': 12, 'latency': None}
{'address': None, 'hostname': 13, 'latency': None}
{'address': None, 'hostname': 14, 'latency': None}
{'address': None, 'hostname': 15, 'latency': None}
1 - 192.168.1.1 - _gateway - 8.21ms - LEN:1
2 - 104.195.128.122 - 104-195-128-122.cpe.teksavvy.com - 1572.38ms - LEN:1
3 - 104.195.128.122 - 104-195-128-122.cpe.teksavvy.com - 15.97ms - LEN:1
4 - 104.195.129.9 - 104-195-129-9.cpe.teksavvy.com - 27.22ms - LEN:1
5 - 206.248.155.92 - ae10-0-bdr01-tor2.teksavvy.com - 20.05ms - LEN:1
6 - 206.248.155.10 - ae12-0-bdr01-tor.teksavvy.com - 27.2ms - LEN:1
7 - * - * - *
8 - * - * - *
9 - * - * - *
10 - * - * - *
11 - * - * - *
12 - * - * - *
13 - * - * - *
14 - * - * - *
15 - * - * - *
谢谢