Remove turbotunnelMode.

Replace it with turboTunnelUDPLikeMode, copying comments etc. to make
the changes easier to see.
This commit is contained in:
David Fifield 2024-08-02 03:33:56 +00:00 committed by WofWca
parent 490502691d
commit 2e4139ea97

View file

@ -1,7 +1,6 @@
package snowflake_server
import (
"bufio"
"crypto/hmac"
"crypto/rand"
"crypto/sha256"
@ -17,7 +16,6 @@ import (
"github.com/gorilla/websocket"
"gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake/v2/common/encapsulation"
"gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake/v2/common/turbotunnel"
"gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake/v2/common/websocketconn"
)
@ -32,7 +30,7 @@ const requestTimeout = 10 * time.Second
const clientMapTimeout = 1 * time.Minute
// How big to make the map of ClientIDs to IP addresses. The map is used in
// turbotunnelMode to store a reasonable IP address for a client session that
// turboTunnelUDPLikeMode to store a reasonable IP address for a client session that
// may outlive any single WebSocket connection.
const clientIDAddrMapCapacity = 98304
@ -117,14 +115,12 @@ func (handler *httpHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
}
}
// turbotunnelMode handles clients that sent turbotunnel.Token at the start of
// their stream. These clients expect to send and receive encapsulated packets,
// with a long-lived session identified by ClientID.
func (handler *httpHandler) turbotunnelMode(conn net.Conn, addr net.Addr) error {
// Read the ClientID prefix. Every packet encapsulated in this WebSocket
// connection pertains to the same ClientID.
var clientID turbotunnel.ClientID
_, err := io.ReadFull(conn, clientID[:])
func (handler *httpHandler) turboTunnelUDPLikeMode(conn net.Conn, addr net.Addr, protocol string) error {
// Read the ClientID from the WebRTC data channel protocol string. Every
// packet received on this WebSocket connection pertains to the same
// ClientID.
clientID := turbotunnel.ClientID{}
_, err := hex.Decode(clientID[:], []byte(protocol))
if err != nil {
return fmt.Errorf("reading ClientID: %w", err)
}
@ -146,8 +142,8 @@ func (handler *httpHandler) turbotunnelMode(conn net.Conn, addr net.Addr) error
wg.Add(2)
done := make(chan struct{})
// The remainder of the WebSocket stream consists of encapsulated
// packets. We read them one by one and feed them into the
// The remainder of the WebSocket stream consists of packets, one packet
// per WebSocket message. We read them one by one and feed them into the
// QueuePacketConn on which kcp.ServeConn was set up, which eventually
// leads to KCP-level sessions in the acceptSessions function.
go func() {
@ -155,11 +151,9 @@ func (handler *httpHandler) turbotunnelMode(conn net.Conn, addr net.Addr) error
defer close(done) // Signal the write loop to finish
var p [2048]byte
for {
n, err := encapsulation.ReadData(conn, p[:])
if err == io.ErrShortBuffer {
err = nil
}
n, err := conn.Read(p[:])
if err != nil {
log.Println(err)
return
}
pconn.QueueIncoming(p[:n], clientID)
@ -168,65 +162,6 @@ func (handler *httpHandler) turbotunnelMode(conn net.Conn, addr net.Addr) error
// At the same time, grab packets addressed to this ClientID and
// encapsulate them into the downstream.
go func() {
defer wg.Done()
defer conn.Close() // Signal the read loop to finish
// Buffer encapsulation.WriteData operations to keep length
// prefixes in the same send as the data that follows.
bw := bufio.NewWriter(conn)
for {
select {
case <-done:
return
case p, ok := <-pconn.OutgoingQueue(clientID):
if !ok {
return
}
_, err := encapsulation.WriteData(bw, p)
pconn.Restore(p)
if err == nil {
err = bw.Flush()
}
if err != nil {
return
}
}
}
}()
wg.Wait()
return nil
}
func (handler *httpHandler) turboTunnelUDPLikeMode(conn net.Conn, addr net.Addr, protocol string) error {
var packet [1600]byte
clientID := turbotunnel.ClientID{}
_, err := hex.Decode(clientID[:], []byte(protocol))
if err != nil {
return fmt.Errorf("reading ClientID: %v", err)
}
clientIDAddrMap.Set(clientID, addr)
pconn := handler.lookupPacketConn(clientID)
var wg sync.WaitGroup
wg.Add(2)
done := make(chan struct{})
go func() {
defer wg.Done()
defer close(done) // Signal the write loop to finish
for {
n, err := conn.Read(packet[:])
if err != nil {
log.Println(err)
return
}
pconn.QueueIncoming(packet[:n], clientID)
}
}()
go func() {
defer wg.Done()
defer conn.Close() // Signal the read loop to finish
@ -249,6 +184,7 @@ func (handler *httpHandler) turboTunnelUDPLikeMode(conn net.Conn, addr net.Addr,
}()
wg.Wait()
return nil
}