80 lines
1.9 KiB
Go
80 lines
1.9 KiB
Go
package dnsforward
|
|
|
|
import (
|
|
"fmt"
|
|
"net"
|
|
|
|
"github.com/AdguardTeam/AdGuardHome/internal/agherr"
|
|
"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
|
|
"github.com/AdguardTeam/dnsproxy/proxy"
|
|
"github.com/AdguardTeam/golibs/log"
|
|
"github.com/AdguardTeam/urlfilter/rules"
|
|
"github.com/miekg/dns"
|
|
)
|
|
|
|
// filterDNSRewriteResponse handles a single DNS rewrite response entry.
|
|
// It returns the constructed answer resource record.
|
|
func (s *Server) filterDNSRewriteResponse(req *dns.Msg, rr rules.RRType, v rules.RRValue) (ans dns.RR, err error) {
|
|
switch rr {
|
|
case dns.TypeA, dns.TypeAAAA:
|
|
ip, ok := v.(net.IP)
|
|
if !ok {
|
|
return nil, fmt.Errorf("value has type %T, not net.IP", v)
|
|
}
|
|
|
|
if rr == dns.TypeA {
|
|
return s.genAAnswer(req, ip.To4()), nil
|
|
}
|
|
|
|
return s.genAAAAAnswer(req, ip), nil
|
|
case dns.TypeTXT:
|
|
str, ok := v.(string)
|
|
if !ok {
|
|
return nil, fmt.Errorf("value has type %T, not string", v)
|
|
}
|
|
|
|
return s.genTXTAnswer(req, []string{str}), nil
|
|
default:
|
|
log.Debug("don't know how to handle dns rr type %d, skipping", rr)
|
|
|
|
return nil, nil
|
|
}
|
|
}
|
|
|
|
// filterDNSRewrite handles dnsrewrite filters. It constructs a DNS
|
|
// response and sets it into d.Res.
|
|
func (s *Server) filterDNSRewrite(req *dns.Msg, res dnsfilter.Result, d *proxy.DNSContext) (err error) {
|
|
resp := s.makeResponse(req)
|
|
dnsrr := res.DNSRewriteResult
|
|
if dnsrr == nil {
|
|
return agherr.Error("no dns rewrite rule content")
|
|
}
|
|
|
|
resp.Rcode = dnsrr.RCode
|
|
if resp.Rcode != dns.RcodeSuccess {
|
|
d.Res = resp
|
|
|
|
return nil
|
|
}
|
|
|
|
if dnsrr.Response == nil {
|
|
return agherr.Error("no dns rewrite rule responses")
|
|
}
|
|
|
|
rr := req.Question[0].Qtype
|
|
values := dnsrr.Response[rr]
|
|
for i, v := range values {
|
|
var ans dns.RR
|
|
ans, err = s.filterDNSRewriteResponse(req, rr, v)
|
|
if err != nil {
|
|
return fmt.Errorf("dns rewrite response for %d[%d]: %w", rr, i, err)
|
|
}
|
|
|
|
resp.Answer = append(resp.Answer, ans)
|
|
}
|
|
|
|
d.Res = resp
|
|
|
|
return nil
|
|
}
|