Client Library

The client package provides a reusable Go library for building DNS tunnel clients.

Import

import "github.com/net2share/vaydns/client"

Usage

There are two ways to use the library:

Step-by-step API

For embedding in frameworks like xray-core where you need control over each layer:

r, _ := client.NewResolver(client.ResolverTypeUDP, "8.8.8.8:53")
ts, _ := client.NewTunnelServer("t.example.com", "pubkey-hex")
t, _ := client.NewTunnel(r, ts)

t.InitiateResolverConnection()
t.InitiateDNSPacketConn(ts.Addr)
t.InitiateKCPConn(ts.MTU)
t.InitiateNoiseChannel()
t.InitiateSmuxSession()

stream, _ := t.OpenStream() // returns net.Conn
defer t.Close()

Each Initiate* method sets up one layer of the protocol stack. OpenStream() returns a net.Conn that can be used like any TCP connection.

Managed API

For standalone clients that need automatic session management and reconnection:

r, _ := client.NewResolver(client.ResolverTypeUDP, "8.8.8.8:53")
ts, _ := client.NewTunnelServer("t.example.com", "pubkey-hex")
t, _ := client.NewTunnel(r, ts)

t.ListenAndServe("127.0.0.1:7000") // blocks, handles reconnection

ListenAndServe opens a local TCP listener, creates tunnel sessions with automatic reconnection on failure, and forwards connections through the tunnel.

Key types

Type	Description
Resolver	DNS transport configuration (UDP, DoT, or DoH)
TunnelServer	Server domain + public key + wire protocol settings
Tunnel	Main tunnel connection with session and timeout configuration
Outbound	High-level API for multiple resolver/server pairs

Resolver types

client.ResolverTypeUDP  // plaintext UDP DNS
client.ResolverTypeDOT  // DNS over TLS (RFC 7858)
client.ResolverTypeDOH  // DNS over HTTPS (RFC 8484)

Configuration

All configuration is done through struct fields before calling Initiate* or ListenAndServe:

// Resolver options
r.UTLSClientHelloID = &utls.ClientHelloID{...} // TLS fingerprint
r.RoundTripper = customTransport                // custom HTTP transport for DoH (overrides UTLSClientHelloID)
r.DialerControl = controlFunc                   // socket options callback (SO_MARK, SO_BINDTODEVICE, etc.)
r.UDPWorkers = 200                              // concurrent UDP workers
r.UDPSharedSocket = true                        // single socket mode
r.UDPTimeout = 500 * time.Millisecond           // per-query timeout
r.UDPAcceptErrors = true                        // accept non-NOERROR responses (disables forged filtering)

// Tunnel server options
ts.DnsttCompat = true    // original dnstt wire format
ts.ClientIDSize = 1      // smaller ClientID
ts.MaxQnameLen = 101     // QNAME length constraint
ts.MaxNumLabels = 2      // label count constraint
ts.RPS = 200             // rate limit queries/second
ts.RecordType = "cname"  // DNS record type for downstream data: txt, null, cname, a, aaaa, mx, ns, srv, caa (default: "txt")

// Session options
t.IdleTimeout = 60 * time.Second
t.KeepAlive = 10 * time.Second
t.OpenStreamTimeout = 10 * time.Second
t.MaxStreams = 256
t.SessionCheckInterval = 500 * time.Millisecond
t.ReconnectMinDelay = 1 * time.Second
t.ReconnectMaxDelay = 30 * time.Second
t.HandshakeTimeout = 15 * time.Second

// Transport queue options
t.PacketQueueSize = 512                                // queue capacity
t.KCPWindowSize = 256                                  // KCP window (0 = queue-size/2)
t.QueueOverflowMode = turbotunnel.QueueOverflowDrop    // "drop" or "block"

Zero values use sensible defaults. See the README for flag descriptions — each flag maps directly to a struct field.