123a76c91e
* middleware/proxy: absorb httpproxy Move the httproxy into proxy. This adds and Exchanger interface which is used to exchange the messages with the upstream. The https_google upstream will re-resolve itself and update the upstream hosts used every 300s. * Remove and add TODO
90 lines
1.9 KiB
Go
90 lines
1.9 KiB
Go
package proxy
|
|
|
|
import (
|
|
"fmt"
|
|
|
|
"github.com/miekg/dns"
|
|
)
|
|
|
|
// toMsg converts a googleMsg into the dns message. The returned RR is the comment disquised as a TXT record.
|
|
func toMsg(g *googleMsg) (*dns.Msg, dns.RR, error) {
|
|
m := new(dns.Msg)
|
|
m.Response = true
|
|
m.Rcode = g.Status
|
|
m.Truncated = g.TC
|
|
m.RecursionDesired = g.RD
|
|
m.RecursionAvailable = g.RA
|
|
m.AuthenticatedData = g.AD
|
|
m.CheckingDisabled = g.CD
|
|
|
|
m.Question = make([]dns.Question, 1)
|
|
m.Answer = make([]dns.RR, len(g.Answer))
|
|
m.Ns = make([]dns.RR, len(g.Authority))
|
|
m.Extra = make([]dns.RR, len(g.Additional))
|
|
|
|
m.Question[0] = dns.Question{Name: g.Question[0].Name, Qtype: g.Question[0].Type, Qclass: dns.ClassINET}
|
|
|
|
var err error
|
|
for i := 0; i < len(m.Answer); i++ {
|
|
m.Answer[i], err = toRR(g.Answer[i])
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
}
|
|
for i := 0; i < len(m.Ns); i++ {
|
|
m.Ns[i], err = toRR(g.Authority[i])
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
}
|
|
for i := 0; i < len(m.Extra); i++ {
|
|
m.Extra[i], err = toRR(g.Additional[i])
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
}
|
|
|
|
txt, _ := dns.NewRR(". 0 CH TXT " + g.Comment)
|
|
return m, txt, nil
|
|
}
|
|
|
|
// toRR transforms a "google" RR to a dns.RR.
|
|
func toRR(g googleRR) (dns.RR, error) {
|
|
typ, ok := dns.TypeToString[g.Type]
|
|
if !ok {
|
|
return nil, fmt.Errorf("failed to convert type %q", g.Type)
|
|
}
|
|
|
|
str := fmt.Sprintf("%s %d %s %s", g.Name, g.TTL, typ, g.Data)
|
|
rr, err := dns.NewRR(str)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to parse %q: %s", str, err)
|
|
}
|
|
return rr, nil
|
|
}
|
|
|
|
// googleRR represents a dns.RR in another form.
|
|
type googleRR struct {
|
|
Name string
|
|
Type uint16
|
|
TTL uint32
|
|
Data string
|
|
}
|
|
|
|
// googleMsg is a JSON representation of the dns.Msg.
|
|
type googleMsg struct {
|
|
Status int
|
|
TC bool
|
|
RD bool
|
|
RA bool
|
|
AD bool
|
|
CD bool
|
|
Question []struct {
|
|
Name string
|
|
Type uint16
|
|
}
|
|
Answer []googleRR
|
|
Authority []googleRR
|
|
Additional []googleRR
|
|
Comment string
|
|
}
|