server: TiDB cannot read the client's remote address in PROXY protocol header

[blacktear23]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

1. start TiDB server with PROXY protocol enabled
2. configure a haproxy and enable PROXY protocol to backend
3. use mysql command connect to TiDB server
4. use show processlist; check the client IP and port

It will show the IP and port from Haproxy server.

2. What did you expect to see? (Required)

show processlist; should show client IP and port that connected to Haproxy.

3. What did you see instead (Required)

show processlist; shows Haproxy server's IP and port.

4. What is your TiDB version? (Required)

from TiDB 6.3.0 to master

5. Reason

From TiDB 6.3.0 it introduce the PROXY protocol lazy mode that can let proxyprotocol library can parse the PROXY protocol header when first Read function call. But at server/conn.go function PeerHost it will cache the connection remote address at first call. And server/server.go function startNetworkListener it will call PeerHost before do the mysql protocol handshake. At that time, the conn.Read not called anymore, so the remote address is connection's remote address not the remote address in PROXY protocol header.

[blacktear23]

@bb7133 from 6.3

[blacktear23]

@bb7133 from 6.3