Implement UDP tunneling over HTTP/3 using HTTP Datagrams (RFC 9297):
- Add masque handler for server-side CONNECT-UDP
- Add masque connector and h3-masque dialer for client-side
- Add enableDatagrams option to HTTP/3 listener
- Add shared utilities for datagram connections and path parsing
Resource management and connection caching:
- Add deferred stream cleanup in connector on error paths
- Add IsClosed() and Close() methods to Client for proper session management
- Clean up stale cached clients in dialer before reuse
- Close underlying stream when DatagramConn is closed
- Move RequestStream opening from connector to dialer to enable dead
connection detection and cache invalidation (follows QUIC dialer pattern)
Extend MASQUE implementation to support TCP tunneling via standard HTTP/3
CONNECT method, in addition to existing UDP support via CONNECT-UDP:
- Add StreamConn type for TCP data transfer over HTTP/3 stream body
- Update handler to dispatch based on :protocol pseudo-header:
- "connect-udp" for UDP (RFC 9298)
- Empty/"HTTP/3.0" for TCP (RFC 9114)
- Add handleConnectTCP() using bidirectional stream relay
- Update connector to support both TCP and UDP networks
- Add connectTCP() for standard CONNECT requests
TCP uses :authority for target address and stream body for data.
UDP uses path template and HTTP/3 datagrams for data.
Implement UDP tunneling over HTTP/3 using HTTP Datagrams (RFC 9297):
- Add masque handler for server-side CONNECT-UDP
- Add masque connector and h3-masque dialer for client-side
- Add enableDatagrams option to HTTP/3 listener
- Add shared utilities for datagram connections and path parsing
Resource management and connection caching:
- Add deferred stream cleanup in connector on error paths
- Add IsClosed() and Close() methods to Client for proper session management
- Clean up stale cached clients in dialer before reuse
- Close underlying stream when DatagramConn is closed
- Move RequestStream opening from connector to dialer to enable dead
connection detection and cache invalidation (follows QUIC dialer pattern)