mirror of
https://github.com/coredns/coredns.git
synced 2025-10-30 17:53:21 -04:00
71ee323651
* add upstream @self and loop count * 1st round of feedback * allow argless upstream * update test * readmes * feedback
56 lines
1.4 KiB
Go
56 lines
1.4 KiB
Go
// Package upstream abstracts a upstream lookups so that plugins
|
|
// can handle them in an unified way.
|
|
package upstream
|
|
|
|
import (
|
|
"github.com/miekg/dns"
|
|
|
|
"github.com/coredns/coredns/core/dnsserver"
|
|
"github.com/coredns/coredns/plugin/pkg/dnsutil"
|
|
"github.com/coredns/coredns/plugin/pkg/nonwriter"
|
|
"github.com/coredns/coredns/plugin/proxy"
|
|
"github.com/coredns/coredns/request"
|
|
)
|
|
|
|
// Upstream is used to resolve CNAME targets
|
|
type Upstream struct {
|
|
self bool
|
|
Forward *proxy.Proxy
|
|
}
|
|
|
|
// NewUpstream creates a new Upstream for given destination(s)
|
|
func NewUpstream(dests []string) (Upstream, error) {
|
|
u := Upstream{}
|
|
if len(dests) == 0 {
|
|
u.self = true
|
|
return u, nil
|
|
}
|
|
u.self = false
|
|
ups, err := dnsutil.ParseHostPortOrFile(dests...)
|
|
if err != nil {
|
|
return u, err
|
|
}
|
|
p := proxy.NewLookup(ups)
|
|
u.Forward = &p
|
|
return u, nil
|
|
}
|
|
|
|
// Lookup routes lookups to Self or Forward
|
|
func (u Upstream) Lookup(state request.Request, name string, typ uint16) (*dns.Msg, error) {
|
|
if u.self {
|
|
// lookup via self
|
|
req := new(dns.Msg)
|
|
req.SetQuestion(name, typ)
|
|
state.SizeAndDo(req)
|
|
nw := nonwriter.New(state.W)
|
|
state2 := request.Request{W: nw, Req: req}
|
|
server := state.Context.Value(dnsserver.Key{}).(*dnsserver.Server)
|
|
server.ServeDNS(state.Context, state2.W, req)
|
|
return nw.Msg, nil
|
|
}
|
|
if u.Forward != nil {
|
|
return u.Forward.Lookup(state, name, typ)
|
|
}
|
|
return &dns.Msg{}, nil
|
|
}
|