grumbulon
3a0a8f015a
All checks were successful
continuous-integration/drone/push Build is passing
refactor Co-authored-by: Sam Therapy <sam@samtherapy.net> Reviewed-on: #110 Reviewed-by: Sam <sam@samtherapy.net>
102 lines
2.1 KiB
Go
102 lines
2.1 KiB
Go
// SPDX-License-Identifier: BSD-3-Clause
|
|
|
|
package resolvers
|
|
|
|
import (
|
|
"crypto/tls"
|
|
"fmt"
|
|
"net"
|
|
|
|
"git.froth.zone/sam/awl/pkg/util"
|
|
"github.com/miekg/dns"
|
|
)
|
|
|
|
// StandardResolver is for UDP/TCP resolvers.
|
|
type StandardResolver struct {
|
|
opts util.Options
|
|
}
|
|
|
|
var _ Resolver = (*StandardResolver)(nil)
|
|
|
|
// LookUp performs a DNS query.
|
|
func (resolver *StandardResolver) LookUp(msg *dns.Msg) (util.Response, error) {
|
|
var (
|
|
resp util.Response
|
|
err error
|
|
)
|
|
|
|
dnsClient := new(dns.Client)
|
|
dnsClient.Dialer = &net.Dialer{
|
|
Timeout: resolver.opts.Request.Timeout,
|
|
}
|
|
|
|
if resolver.opts.TCP || resolver.opts.TLS {
|
|
dnsClient.Net = tcp
|
|
} else {
|
|
dnsClient.Net = udp
|
|
}
|
|
|
|
switch {
|
|
case resolver.opts.IPv4:
|
|
dnsClient.Net += "4"
|
|
case resolver.opts.IPv6:
|
|
dnsClient.Net += "6"
|
|
}
|
|
|
|
if resolver.opts.TLS {
|
|
dnsClient.Net += "-tls"
|
|
dnsClient.TLSConfig = &tls.Config{
|
|
//nolint:gosec // This is intentional if the user requests it
|
|
InsecureSkipVerify: resolver.opts.TLSNoVerify,
|
|
ServerName: resolver.opts.TLSHost,
|
|
}
|
|
}
|
|
|
|
resolver.opts.Logger.Info("Using", dnsClient.Net, "for making the request")
|
|
|
|
resp.DNS, resp.RTT, err = dnsClient.Exchange(msg, resolver.opts.Request.Server)
|
|
if err != nil {
|
|
return util.Response{}, fmt.Errorf("standard: DNS exchange: %w", err)
|
|
}
|
|
|
|
switch dns.RcodeToString[resp.DNS.MsgHdr.Rcode] {
|
|
case "BADCOOKIE":
|
|
if !resolver.opts.BadCookie {
|
|
fmt.Printf(";; BADCOOKIE, retrying.\n\n")
|
|
|
|
msg.Extra = resp.DNS.Extra
|
|
|
|
resp.DNS, resp.RTT, err = dnsClient.Exchange(msg, resolver.opts.Request.Server)
|
|
|
|
if err != nil {
|
|
return util.Response{}, fmt.Errorf("badcookie: DNS exchange: %w", err)
|
|
}
|
|
}
|
|
|
|
case "NOERR":
|
|
break
|
|
}
|
|
|
|
resolver.opts.Logger.Info("Request successful")
|
|
|
|
if resp.DNS.MsgHdr.Truncated && !resolver.opts.Truncate {
|
|
fmt.Printf(";; Truncated, retrying with TCP\n\n")
|
|
|
|
dnsClient.Net = tcp
|
|
|
|
switch {
|
|
case resolver.opts.IPv4:
|
|
dnsClient.Net += "4"
|
|
case resolver.opts.IPv6:
|
|
dnsClient.Net += "6"
|
|
}
|
|
|
|
resp.DNS, resp.RTT, err = dnsClient.Exchange(msg, resolver.opts.Request.Server)
|
|
}
|
|
|
|
if err != nil {
|
|
return util.Response{}, fmt.Errorf("standard: DNS exchange: %w", err)
|
|
}
|
|
|
|
return resp, nil
|
|
}
|