The socks README says "Built-in DNS resolution through the VPN tunnel", but it seems to use system DNS actually.
From curl -x socks5h://localhost:9999 dw.com, the socks says Dialing tcp 173.255.209.47:80 dw.com.
And 173.255.209.47 is not DW's IP address but a known address injected by GFW.
The socks README says "Built-in DNS resolution through the VPN tunnel", but it seems to use system DNS actually.
From
curl -x socks5h://localhost:9999 dw.com, the socks saysDialing tcp 173.255.209.47:80 dw.com.And
173.255.209.47is not DW's IP address but a known address injected by GFW.