64 lines
1.4 KiB
Go
64 lines
1.4 KiB
Go
package dnsforward
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import (
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"context"
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"fmt"
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"net"
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"net/netip"
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"strconv"
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"time"
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"github.com/AdguardTeam/golibs/errors"
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"github.com/AdguardTeam/golibs/log"
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)
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// DialContext is an [aghnet.DialContextFunc] that uses s to resolve hostnames.
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// addr should be a valid host:port address, where host could be a domain name
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// or an IP address.
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func (s *Server) DialContext(ctx context.Context, network, addr string) (conn net.Conn, err error) {
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log.Debug("dnsforward: dialing %q for network %q", addr, network)
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host, portStr, err := net.SplitHostPort(addr)
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if err != nil {
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return nil, err
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}
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dialer := &net.Dialer{
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// TODO(a.garipov): Consider making configurable.
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Timeout: time.Minute * 5,
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}
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if net.ParseIP(host) != nil {
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return dialer.DialContext(ctx, network, addr)
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}
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port, err := strconv.Atoi(portStr)
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if err != nil {
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return nil, fmt.Errorf("invalid port %s: %w", portStr, err)
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}
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ips, err := s.Resolve(ctx, network, host)
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if err != nil {
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return nil, fmt.Errorf("resolving %q: %w", host, err)
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} else if len(ips) == 0 {
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return nil, fmt.Errorf("no addresses for host %q", host)
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}
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log.Debug("dnsforward: resolved %q: %v", host, ips)
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var dialErrs []error
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for _, ip := range ips {
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addrPort := netip.AddrPortFrom(ip, uint16(port))
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conn, err = dialer.DialContext(ctx, network, addrPort.String())
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if err != nil {
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dialErrs = append(dialErrs, err)
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continue
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}
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return conn, nil
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}
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return nil, errors.Join(dialErrs...)
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}
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