Files
frp/pkg/util/net/dial.go
Shani Pathak ba7adcab8f fix(websocket): send tunnel payload as binary frames (#5363)
The ws/wss transport carries a raw byte stream (yamux), but the
golang.org/x/net/websocket Conn defaults to text frames (PayloadType
TextFrame). Per RFC 6455 §5.6 a text frame must contain valid UTF-8, so
RFC-compliant intermediaries (API gateways / reverse proxies) validate
the payload and close the connection when the binary tunnel data is not
valid UTF-8.

This goes unnoticed peer-to-peer because x/net/websocket does not
validate UTF-8 on read, but it breaks the connection through a compliant
validating proxy. Set PayloadType to BinaryFrame on both the server
listener and the client dialer so the tunnel is framed as binary.
2026-06-22 23:34:02 +08:00

56 lines
1.4 KiB
Go

package net
import (
"context"
"net"
"net/url"
libnet "github.com/fatedier/golib/net"
"golang.org/x/net/websocket"
)
func DialHookCustomTLSHeadByte(enableTLS bool, disableCustomTLSHeadByte bool) libnet.AfterHookFunc {
return func(ctx context.Context, c net.Conn, addr string) (context.Context, net.Conn, error) {
if enableTLS && !disableCustomTLSHeadByte {
_, err := c.Write([]byte{byte(FRPTLSHeadByte)})
if err != nil {
return nil, nil, err
}
}
return ctx, c, nil
}
}
func DialHookWebsocket(protocol string, host string) libnet.AfterHookFunc {
return func(ctx context.Context, c net.Conn, addr string) (context.Context, net.Conn, error) {
if protocol != "wss" {
protocol = "ws"
}
if host == "" {
host = addr
}
addr = protocol + "://" + host + FrpWebsocketPath
uri, err := url.Parse(addr)
if err != nil {
return nil, nil, err
}
origin := "http://" + uri.Host
cfg, err := websocket.NewConfig(addr, origin)
if err != nil {
return nil, nil, err
}
conn, err := websocket.NewClient(cfg, c)
if err != nil {
return nil, nil, err
}
// The tunnel payload is a raw byte stream (yamux), not UTF-8 text.
// Send it as binary frames; otherwise RFC 6455-compliant intermediaries
// (e.g. API gateways/reverse proxies) UTF-8-validate the default text
// frames and close the connection on invalid bytes.
conn.PayloadType = websocket.BinaryFrame
return ctx, conn, nil
}
}