feat(dns): add dnscrypt and dns over tcp

2026-02-04 22:08:05 +00:00
parent 5d9b630d13
commit 92351a80a9
12 changed files with 2576 additions and 568 deletions
--- a/common/protocols/doudp/doudp.go
+++ b/common/protocols/doudp/doudp.go
@@ -0,0 +1,122 @@
+package doudp
+
+import (
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/afonsofrancof/sdns-proxy/common/logger"
+	"github.com/miekg/dns"
+)
+
+type Config struct {
+	HostAndPort  string
+	DNSSEC       bool
+	WriteTimeout time.Duration
+	ReadTimeout  time.Duration
+}
+
+type Client struct {
+	hostAndPort string
+	config      Config
+}
+
+func New(config Config) (*Client, error) {
+	logger.Debug("Creating DoUDP client: %s", config.HostAndPort)
+
+	if config.HostAndPort == "" {
+		logger.Error("DoUDP client creation failed: empty HostAndPort")
+		return nil, fmt.Errorf("doudp: HostAndPort cannot be empty")
+	}
+	if config.WriteTimeout <= 0 {
+		config.WriteTimeout = 2 * time.Second
+	}
+	if config.ReadTimeout <= 0 {
+		config.ReadTimeout = 5 * time.Second
+	}
+
+	logger.Debug("DoUDP client created: %s (DNSSEC: %v)", config.HostAndPort, config.DNSSEC)
+
+	return &Client{
+		hostAndPort: config.HostAndPort,
+		config:      config,
+	}, nil
+}
+
+func (c *Client) Close() {
+	logger.Debug("Closing DoUDP client")
+}
+
+func (c *Client) createConnection() (*net.UDPConn, error) {
+	udpAddr, err := net.ResolveUDPAddr("udp", c.hostAndPort)
+	if err != nil {
+		logger.Error("DoUDP failed to resolve address %s: %v", c.hostAndPort, err)
+		return nil, fmt.Errorf("failed to resolve UDP address: %w", err)
+	}
+
+	conn, err := net.DialUDP("udp", nil, udpAddr)
+	if err != nil {
+		logger.Error("DoUDP failed to connect to %s: %v", c.hostAndPort, err)
+		return nil, err
+	}
+
+	logger.Debug("DoUDP connection established to %s", c.hostAndPort)
+	return conn, nil
+}
+
+func (c *Client) Query(msg *dns.Msg) (*dns.Msg, error) {
+	if len(msg.Question) > 0 {
+		question := msg.Question[0]
+		logger.Debug("DoUDP query: %s %s to %s", question.Name, dns.TypeToString[question.Qtype], c.hostAndPort)
+	}
+
+	conn, err := c.createConnection()
+	if err != nil {
+		return nil, fmt.Errorf("doudp: failed to create connection: %w", err)
+	}
+	defer conn.Close()
+
+	if c.config.DNSSEC {
+		msg.SetEdns0(4096, true)
+	}
+
+	packedMsg, err := msg.Pack()
+	if err != nil {
+		logger.Error("DoUDP failed to pack message: %v", err)
+		return nil, fmt.Errorf("doudp: failed to pack DNS message: %w", err)
+	}
+
+	if err := conn.SetWriteDeadline(time.Now().Add(c.config.WriteTimeout)); err != nil {
+		logger.Error("DoUDP failed to set write deadline: %v", err)
+		return nil, fmt.Errorf("doudp: failed to set write deadline: %w", err)
+	}
+
+	if _, err := conn.Write(packedMsg); err != nil {
+		logger.Error("DoUDP failed to send query to %s: %v", c.hostAndPort, err)
+		return nil, fmt.Errorf("doudp: failed to send DNS query: %w", err)
+	}
+
+	if err := conn.SetReadDeadline(time.Now().Add(c.config.ReadTimeout)); err != nil {
+		logger.Error("DoUDP failed to set read deadline: %v", err)
+		return nil, fmt.Errorf("doudp: failed to set read deadline: %w", err)
+	}
+
+	buffer := make([]byte, dns.MaxMsgSize)
+	n, err := conn.Read(buffer)
+	if err != nil {
+		logger.Error("DoUDP failed to read response from %s: %v", c.hostAndPort, err)
+		return nil, fmt.Errorf("doudp: failed to read DNS response: %w", err)
+	}
+
+	response := new(dns.Msg)
+	if err := response.Unpack(buffer[:n]); err != nil {
+		logger.Error("DoUDP failed to unpack response from %s: %v", c.hostAndPort, err)
+		return nil, fmt.Errorf("doudp: failed to unpack DNS response: %w", err)
+	}
+
+	if len(response.Answer) > 0 {
+		logger.Debug("DoUDP response from %s: %d answers", c.hostAndPort, len(response.Answer))
+	}
+
+	return response, nil
+}