????????

????Tcpcopy
??????????Tcpcopy???????????????????????????????????????????????raw socket input ?????????????pcap ????????????Libpcap??Packet Capture Libray???????д????????????????????????C???????????????????????????????????y??????????????????????????????Tcpdump????Libpcap????????????????Libpcap????????????????????????????й????????????????????????ο?http://www.cnblogs.com/coder2012/archive/2013/04/13/3012390.html??????????????????????????????????Pcap???????????????￡?
????./configure --enable-advanced --enable-pcap
????make
????make install
??????????????????????????Raw socket output ????????????Raw Socket?????????????￡? ./tcpcopy -x 80-?????IP:?????????? -s ?????????IP -i eth0 ??????-i???????pcap??????????????????
????????????????????pcap_inject?????????????--enable-dlinject?????????????pcap_inject??????????????1.???????????????IP???????????????tcpcopy??????????????IP?????????????IP??????????????????????????????????????????￡?????pacp_inject??????????·????????????IP??????????????2.???????????????????pcap_inject ?????????????????????????????pcap_inject ???????????30%??????(?????????)??????pcap_inject????????????????????????????????????????????????????tcpdump??????????.
????Pcap????????sudo ./tcpcopy -x ???????@???????????????????-?????????IP???:???????????@???????????? -s ????intercept?????IP??? -o ?????????豸 -i ????????豸??
?????????????
?????????????????????????????·???????????????????ó?????????·?????????????????????????????????￡?
??????????????????????IP?????·??
????route del default gw ?????????IP
???????????????????IP?????????????????·??
????route add default gw ????????????????IP
??????????????????????????????????????????????????-????????????????IP??????????????????п???·????????????Щ???????????????????????ip??drop???????internet?????????????????????????????·???????Щ?????
??????????????
??????????????????????????????????????????????????????????????????п???·????cat /proc/sys/net/ipv4/ip_forward???0?????п???????????????????????pcap???????????????????￡?
????./configure --enable-advanced --enable-pcap
????make
????make install
??????????????intercept???????pcap?????????ó?????????????????????????????tcpcopy????????????????????
????С??
????Tcpcopy??????????????????????Щ???繤????????臨?????????????????rawsocket+iptable+netlink??????pacp+route????????????????????????????????????????????Щ??????????????????????????????
?????????????????????????????????????ó???????????????????????????????????linux??IP_QUEUE??飬????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????ε????????????????????????????????????????????????