127 lines
3.4 KiB
Go
127 lines
3.4 KiB
Go
package do53
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import (
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"fmt"
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"net"
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"time"
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"github.com/afonsofrancof/sdns-proxy/common/logger"
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"github.com/miekg/dns"
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)
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type Config struct {
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HostAndPort string
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DNSSEC bool
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WriteTimeout time.Duration
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ReadTimeout time.Duration
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}
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type Client struct {
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hostAndPort string
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config Config
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}
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func New(config Config) (*Client, error) {
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logger.Debug("Creating DO53 client: %s", config.HostAndPort)
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if config.HostAndPort == "" {
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logger.Error("DO53 client creation failed: empty HostAndPort")
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return nil, fmt.Errorf("do53: HostAndPort cannot be empty")
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}
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if config.WriteTimeout <= 0 {
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config.WriteTimeout = 2 * time.Second
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}
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if config.ReadTimeout <= 0 {
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config.ReadTimeout = 5 * time.Second
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}
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logger.Debug("DO53 client created: %s (DNSSEC: %v)", config.HostAndPort, config.DNSSEC)
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return &Client{
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hostAndPort: config.HostAndPort,
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config: config,
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}, nil
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}
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func (c *Client) Close() {
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logger.Debug("Closing DO53 client")
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}
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func (c *Client) createConnection() (*net.UDPConn, error) {
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udpAddr, err := net.ResolveUDPAddr("udp", c.hostAndPort)
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if err != nil {
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logger.Error("DO53 failed to resolve address %s: %v", c.hostAndPort, err)
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return nil, fmt.Errorf("failed to resolve UDP address: %w", err)
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}
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conn, err := net.DialUDP("udp", nil, udpAddr)
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if err != nil {
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logger.Error("DO53 failed to connect to %s: %v", c.hostAndPort, err)
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return nil, err
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}
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logger.Debug("DO53 connection established to %s", c.hostAndPort)
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return conn, nil
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}
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func (c *Client) Query(msg *dns.Msg) (*dns.Msg, error) {
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if len(msg.Question) > 0 {
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question := msg.Question[0]
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logger.Debug("DO53 query: %s %s to %s", question.Name, dns.TypeToString[question.Qtype], c.hostAndPort)
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}
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// Create connection for this query
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conn, err := c.createConnection()
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if err != nil {
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return nil, fmt.Errorf("do53: failed to create connection: %w", err)
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}
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defer conn.Close()
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if c.config.DNSSEC {
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msg.SetEdns0(4096, true)
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}
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packedMsg, err := msg.Pack()
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if err != nil {
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logger.Error("DO53 failed to pack message: %v", err)
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return nil, fmt.Errorf("do53: failed to pack DNS message: %w", err)
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}
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// Send query
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if err := conn.SetWriteDeadline(time.Now().Add(c.config.WriteTimeout)); err != nil {
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logger.Error("DO53 failed to set write deadline: %v", err)
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return nil, fmt.Errorf("do53: failed to set write deadline: %w", err)
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}
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if _, err := conn.Write(packedMsg); err != nil {
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logger.Error("DO53 failed to send query to %s: %v", c.hostAndPort, err)
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return nil, fmt.Errorf("do53: failed to send DNS query: %w", err)
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}
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// Read response
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if err := conn.SetReadDeadline(time.Now().Add(c.config.ReadTimeout)); err != nil {
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logger.Error("DO53 failed to set read deadline: %v", err)
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return nil, fmt.Errorf("do53: failed to set read deadline: %w", err)
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}
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buffer := make([]byte, dns.MaxMsgSize)
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n, err := conn.Read(buffer)
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if err != nil {
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logger.Error("DO53 failed to read response from %s: %v", c.hostAndPort, err)
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return nil, fmt.Errorf("do53: failed to read DNS response: %w", err)
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}
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// Parse response
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response := new(dns.Msg)
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if err := response.Unpack(buffer[:n]); err != nil {
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logger.Error("DO53 failed to unpack response from %s: %v", c.hostAndPort, err)
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return nil, fmt.Errorf("do53: failed to unpack DNS response: %w", err)
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}
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if len(response.Answer) > 0 {
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logger.Debug("DO53 response from %s: %d answers", c.hostAndPort, len(response.Answer))
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}
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return response, nil
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}
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