Linux：如何模拟接口上的传入数据包？

Question

How can I simulate some incoming traffic on a specific software interface? The reason for this need is that we have a couple of software interfaces between Ether level and IP level, which will parse our own L2.5 headers along the network stack, ie

eth header -> virt_dev1 -> virt_dev2 -> IP -> TCP

I was looking at TAP, which looks like it can help. But I do not understand how to chain this TAP interface to our own software interfaces so the packets will go through the expected network stack? Maybe my understanding of TAP is not correct?

Thanks,

Answer 1

The tap interface acts like a Layer 2 port to the networking stack - reading and writing from the device node will ingest/retrieve packets from the networking layer. Where those packets go after that point is up to the networking configuration (forwarding, bridging, etc).