Python原始套接字编程

在实验中需要自己构造单独的HTTP数据报文，而使用SOCK_STREAM进行发送数据包，需要进行完整的TCP交互。

因此想使用原始套接字进行编程，直接构造数据包，并在IP层进行发送，即采用SOCK_RAW进行数据发送。

使用SOCK_RAW的优势是，可以对数据包进行完整的修改，可以处理IP层上的所有数据包，对各字段进行修改，而不受UDP和TCP的限制。

下面开始构造HTTP数据包，

IP层和TCP层使用python的Impacket库，http内容自行填写。

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#!/usr/bin/env python   #------------------------------------------------------------------------------- # Name:     raw_http.py # Purpose:       construct a raw http get packet # # Author:     Yangjun # # Created:       08/02/2014 # Copyright:   (c) Yangjun 2014 # Licence:       <your licence> #-------------------------------------------------------------------------------   import sys import socket from impacket import ImpactDecoder, ImpactPacket   def main():       if len(sys.argv) < 3:         print "Use: %s <src ip> <dst ip>" % sys.argv[0]         print "Use: %s <src ip> <dst ip> <cnt>" % sys.argv[0]         sys.exit(1)     elif len(sys.argv) == 3:         src = sys.argv[1]         dst = sys.argv[2]         cnt = 1     elif len(sys.argv) ==4:         src = sys.argv[1]         dst = sys.argv[2]         cnt = sys.argv[3]     else:         print "Input error!"         sys.exit(1) #print src, dst     ip = ImpactPacket.IP()     ip.set_ip_src(src)     ip.set_ip_dst(dst)       # Create a new ICMP packet of type ECHO.     icmp = ImpactPacket.ICMP()     tcp = ImpactPacket.TCP()     tcp.set_th_sport(55968)     tcp.set_th_dport(80)     tcp.set_th_seq(1)     tcp.set_th_ack(1)     tcp.set_th_flags(0x18)     tcp.set_th_win(64)       tcp.contains( ImpactPacket.Data("GET /att/DIYLife/41264/528 HTTP/1.1\r\nHost: 192.168.111.1\r\nAccept-Encoding: identity\r\n\r\n"))       ip.contains(tcp)       # Open a raw socket. Special permissions are usually required.     s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_TCP)     s.setsockopt(socket.IPPROTO_IP, socket.IP_HDRINCL, 1)     seq_id = 0     while cnt >= 1:         # Calculate its checksum.         seq_id = seq_id + 1         tcp.set_th_seq(seq_id)         tcp.calculate_checksum()           # Send it to the target host.         s.sendto(ip.get_packet(), (dst,80))         cnt= cnt -1   if __name__ == '__main__':     main()

运行后抓包如下：