What does "winpcap can't stop, filter and take control of other applications" mean?

"Because winpcap sends and receives data independent of host protocol such as TCP/IP, which means winpcap can't stop, filter and take control of other applications on the same machine control, it开发者_运维知识库 can only monitor them simply, so it can't provide support for similar network flow control, the quality of service, personal firewall and so on."

In this passage, what "winpcap can't stop, filter and take control of other applications on the same machine control" means?

It means that if some program on your machine is sending and receiving packets, the path those packets take through the operating system does not, and cannot, go through WinPcap; all WinPcap can do is listen to see copies of the packets sent and received by the machine.

This means that if you want to, for example, implement a firewall program to prevent other programs from connecting to particular addresses or ports or receiving connections from particular addresses or ports, or to modify packets sent by other programs before they get put onto the network or modify packets received from the network before they get passed to other programs, or do something else "active", you cannot use WinPcap.

WinPcap uses mechanisms in Windows that are intended to support programs such as packet sniffers, so that limitation is inherent in WinPcap; a library to support writing firewalls and the like would have to use different mechanisms in Windows (and those mechanisms might not support programs such as packet sniffers).