extern/netbird
1
0
Fork 0
mirror of https://github.com/netbirdio/netbird.git synced 2025-08-13 17:07:30 +02:00
Code Issues Packages Projects Releases Wiki Activity

[client] Fallback to TCP if a truncated UDP response is received from upstream DNS (#3632)

Browse Source
This commit is contained in:
Viktor Liu
2025-04-08 13:41:13 +02:00
committed by GitHub
parent 192c97aa63
commit 03f600b576
5 changed files with 53 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
client/internal/routemanager/dnsinterceptor/handler.go
View File

@ -162,9 +162,7 @@ func (d *DnsInterceptor) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
return
}
// set the AuthenticatedData flag and the EDNS0 buffer size to 4096 bytes to support larger dns records
if r.Extra == nil {
r.SetEdns0(4096, false)
r.MsgHdr.AuthenticatedData = true
}
client := &dns.Client{
@ -172,7 +170,7 @@ func (d *DnsInterceptor) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
Net: "udp",
}
upstream := fmt.Sprintf("%s:%d", upstreamIP.String(), dnsfwd.ListenPort)
reply, _, err := client.ExchangeContext(context.Background(), r, upstream)
reply, _, err := nbdns.ExchangeWithFallback(context.TODO(), client, r, upstream)
if err != nil {
log.Errorf("failed to exchange DNS request with %s (%s) for domain=%s: %v", upstreamIP.String(), peerKey, r.Question[0].Name, err)
if err := w.WriteMsg(&dns.Msg{MsgHdr: dns.MsgHdr{Rcode: dns.RcodeServerFailure, Id: r.Id}}); err != nil {