github.com/xtls/xray-core@v1.8.12-0.20240518155711-3168d27b0bdb/app/dns/nameserver_local.go (about)

     1  package dns
     2  
     3  import (
     4  	"context"
     5  	"strings"
     6  	"time"
     7  
     8  	"github.com/xtls/xray-core/common/log"
     9  	"github.com/xtls/xray-core/common/net"
    10  	"github.com/xtls/xray-core/features/dns"
    11  	"github.com/xtls/xray-core/features/dns/localdns"
    12  )
    13  
    14  // LocalNameServer is an wrapper over local DNS feature.
    15  type LocalNameServer struct {
    16  	client *localdns.Client
    17  }
    18  
    19  const errEmptyResponse = "No address associated with hostname"
    20  
    21  // QueryIP implements Server.
    22  func (s *LocalNameServer) QueryIP(_ context.Context, domain string, _ net.IP, option dns.IPOption, _ bool) (ips []net.IP, err error) {
    23  	start := time.Now()
    24  	ips, err = s.client.LookupIP(domain, option)
    25  
    26  	if err != nil && strings.HasSuffix(err.Error(), errEmptyResponse) {
    27  		err = dns.ErrEmptyResponse
    28  	}
    29  
    30  	if len(ips) > 0 {
    31  		newError("Localhost got answer: ", domain, " -> ", ips).AtInfo().WriteToLog()
    32  		log.Record(&log.DNSLog{Server: s.Name(), Domain: domain, Result: ips, Status: log.DNSQueried, Elapsed: time.Since(start), Error: err})
    33  	}
    34  
    35  	return
    36  }
    37  
    38  // Name implements Server.
    39  func (s *LocalNameServer) Name() string {
    40  	return "localhost"
    41  }
    42  
    43  // NewLocalNameServer creates localdns server object for directly lookup in system DNS.
    44  func NewLocalNameServer() *LocalNameServer {
    45  	newError("DNS: created localhost client").AtInfo().WriteToLog()
    46  	return &LocalNameServer{
    47  		client: localdns.New(),
    48  	}
    49  }
    50  
    51  // NewLocalDNSClient creates localdns client object for directly lookup in system DNS.
    52  func NewLocalDNSClient() *Client {
    53  	return &Client{server: NewLocalNameServer()}
    54  }