Based on PCAP analysis of official Mi Home app traffic, the keepalive
mechanism was incorrect:
Before (broken):
- Sent PING every 5s only when receiving data
- Responded to PING with PONG
After (fixed):
- Send PING every 1 second independently via dedicated goroutine
- Don't respond to PING with PONG (official app doesn't either)
- Both sides send PING bidirectionally as heartbeats
The official app sends 199 PING messages and 0 PONG messages in a
typical session. This fix matches that behavior.
Fixes connection resets after prolonged streaming sessions with
Xiaomi cameras using the CS2 P2P protocol.
Johnnybyzhang
Alex X