Question

我在python中使用此代码向udp跟踪器发送连接请求和annouce请求，

clisocket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
print clisocket
connection_id = 0x41727101980
transaction_id = randrange(1, 65535)
info_hash = info_hash
peer_id = "ABCDEFGHIJKLMNOPQRST"
action = 0
downloaded = 0
left = 0
uploaded = 0
event = 2
ip = 0
key = 0
num_want = 10
port = 9999

connect_pack = struct.pack(">QLL", connection_id, action, transaction_id)
clisocket.sendto(connect_pack, ("tracker.publicbt.com", 80))
res = clisocket.recv(16)
action, transaction_id, connection_id = struct.unpack(">LLQ", res)

announce_pack = struct.pack(">QLL20s20sQQQLLLLH", connection_id, 1, transaction_id, info_hash, peer_id, downloaded, left, uploaded, event, ip, key, num_want, port)
clisocket.sendto(announce_pack, ("tracker.publicbt.com", 80))
res = clisocket.recv(1024)
action = struct.unpack("!LLLLLLH", res[:26])
print action

我收到了这个回复，

(1, 56347, 1782, 0, 1, 838084381, 9999)

根据协议规范[link]：http://www.bittorrent.org/beps/bep_0015.html

我到了 annouce即1 transaction_id，即56347，与生成的transaction_id相同但是代替端口我正在收到我在发布请求中发送的端口，而不是IP，我得到了838084381。这是我应该从udp跟踪器获得的响应吗？如何解析同行的ip？

Answer 1

IP地址以32位打包格式返回。您可以将其转换为点状四字符串表示形式，如下所示：

import socket, struct    
ip = socket.inet_ntoa(struct.pack('!L', 838084381))    
print ip; # prints 49.244.39.29

Reference

如何从UDP跟踪器响应中解析对等体的IP和端口

1 个答案: