我需要通过套接字发送数据包，并希望包含一些元信息而不改变数据包内容本身。这可能吗？如果是：我可以在perl中进行吗？
我正在编写代理服务器，当我向代理服务器发送数据包时，我需要以某种方式包含应用程序的端口，代理服务器位于客户端和我想要使用的服务器之间。
答案 0 :(得分：1)
您可以使用Net::ProxyMod
Description Net::ProxyMod
This is a small module that allows you to create a proxy for packet alteration
and debugging. You just need to specify two functions in and outgoing packets
will be passed to. In these functions you can then modify the packet if desired.
This is useful to get in between an existing client and server for testing
purposes.
ProxyMod can be used as a standard proxy or as a transparent proxy together
with a firewall package such as ipfw on FreeBSD. Please refer to the ipfw
documenation for more information.
或尝试Net::Divert
Description Net::Divert
The Net::Divert module facilitates the use of divert sockets for packet alteration
on FreeBSD and MacOSX.
Divert sockets can be bound to a certain port. This port will then receive all
packets you divert to it with the help of a divert filter rule. On FreeBSD and
MacOSX ipfw allows you to add such a rule. Please refer to the divert and ipfw
manpages for more information.
This module allows you to create a divert socket and then just supply a function
that will deal with the incoming packets.
new(host,port) will create a new divert object. It will also create a divert
socket bound to the specified port at the given host/ip.
getPackets(func) will create a loop getting all incoming packets and pass them
onto the specified function you created. This function will be called with two
arguments: packet and fwtag. Fwtag contains the rule number where the packet is
reinserted. Refer to divert(4) for more information.
putPacket(packet,fwtag) reinsert a packet at the specified fw rule (normally you
don't want to alter fwtag, as it is easy to create infinite loops this way)