mirror of
https://github.com/coredns/coredns.git
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ad76aef5fc
Make the receiver a pointer so that the uptdateStubZones map update will retain the stubzones found, unlike the current case where the update will be applied and then promptly forgotten, because it is working on a copy. Add test/etcd_test.go to test a large part of the code. This didn't catch the chaos middleware hack though. The chaos middleware zones are now *not* automatically added. You have to take care of that by yourself (docs updates). When using debug queries and falling through to the next middleware in etcd, restore the original (with o-o.debug) query before passing it on.
408 lines
11 KiB
Go
408 lines
11 KiB
Go
package etcd
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import (
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"fmt"
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"math"
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"net"
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"time"
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"github.com/miekg/coredns/middleware"
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"github.com/miekg/coredns/middleware/etcd/msg"
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"github.com/miekg/dns"
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)
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type Options struct {
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Debug string
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}
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func (e Etcd) records(state middleware.State, exact bool, opt Options) (services, debug []msg.Service, err error) {
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services, err = e.Records(state.Name(), exact)
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if err != nil {
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return
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}
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if opt.Debug != "" {
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debug = services
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}
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services = msg.Group(services)
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return
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}
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func (e Etcd) A(zone string, state middleware.State, previousRecords []dns.RR, opt Options) (records []dns.RR, debug []msg.Service, err error) {
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services, debug, err := e.records(state, false, opt)
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if err != nil {
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return nil, debug, err
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}
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for _, serv := range services {
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ip := net.ParseIP(serv.Host)
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switch {
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case ip == nil:
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// TODO(miek): lowercasing? Should lowercase in everything see #85
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if middleware.Name(state.Name()).Matches(dns.Fqdn(serv.Host)) {
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// x CNAME x is a direct loop, don't add those
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continue
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}
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newRecord := serv.NewCNAME(state.QName(), serv.Host)
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if len(previousRecords) > 7 {
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// don't add it, and just continue
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continue
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}
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if isDuplicateCNAME(newRecord, previousRecords) {
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continue
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}
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state1 := copyState(state, serv.Host, state.QType())
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nextRecords, nextDebug, err := e.A(zone, state1, append(previousRecords, newRecord), opt)
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if err == nil {
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// Not only have we found something we should add the CNAME and the IP addresses.
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if len(nextRecords) > 0 {
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records = append(records, newRecord)
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records = append(records, nextRecords...)
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debug = append(debug, nextDebug...)
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}
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continue
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}
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// This means we can not complete the CNAME, try to look else where.
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target := newRecord.Target
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if dns.IsSubDomain(zone, target) {
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// We should already have found it
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continue
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}
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m1, e1 := e.Proxy.Lookup(state, target, state.QType())
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if e1 != nil {
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continue
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}
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// Len(m1.Answer) > 0 here is well?
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records = append(records, newRecord)
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records = append(records, m1.Answer...)
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continue
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case ip.To4() != nil:
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records = append(records, serv.NewA(state.QName(), ip.To4()))
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case ip.To4() == nil:
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// nodata?
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}
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}
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return records, debug, nil
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}
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func (e Etcd) AAAA(zone string, state middleware.State, previousRecords []dns.RR, opt Options) (records []dns.RR, debug []msg.Service, err error) {
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services, debug, err := e.records(state, false, opt)
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if err != nil {
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return nil, debug, err
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}
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for _, serv := range services {
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ip := net.ParseIP(serv.Host)
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switch {
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case ip == nil:
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// Try to resolve as CNAME if it's not an IP, but only if we don't create loops.
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if middleware.Name(state.Name()).Matches(dns.Fqdn(serv.Host)) {
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// x CNAME x is a direct loop, don't add those
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continue
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}
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newRecord := serv.NewCNAME(state.QName(), serv.Host)
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if len(previousRecords) > 7 {
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// don't add it, and just continue
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continue
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}
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if isDuplicateCNAME(newRecord, previousRecords) {
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continue
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}
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state1 := copyState(state, serv.Host, state.QType())
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nextRecords, nextDebug, err := e.AAAA(zone, state1, append(previousRecords, newRecord), opt)
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if err == nil {
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// Not only have we found something we should add the CNAME and the IP addresses.
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if len(nextRecords) > 0 {
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records = append(records, newRecord)
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records = append(records, nextRecords...)
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debug = append(debug, nextDebug...)
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}
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continue
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}
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// This means we can not complete the CNAME, try to look else where.
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target := newRecord.Target
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if dns.IsSubDomain(zone, target) {
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// We should already have found it
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continue
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}
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m1, e1 := e.Proxy.Lookup(state, target, state.QType())
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if e1 != nil {
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continue
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}
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// Len(m1.Answer) > 0 here is well?
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records = append(records, newRecord)
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records = append(records, m1.Answer...)
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continue
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// both here again
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case ip.To4() != nil:
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// nada?
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case ip.To4() == nil:
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records = append(records, serv.NewAAAA(state.QName(), ip.To16()))
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}
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}
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return records, debug, nil
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}
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// SRV returns SRV records from etcd.
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// If the Target is not a name but an IP address, a name is created on the fly.
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func (e Etcd) SRV(zone string, state middleware.State, opt Options) (records, extra []dns.RR, debug []msg.Service, err error) {
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services, debug, err := e.records(state, false, opt)
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if err != nil {
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return nil, nil, nil, err
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}
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// Looping twice to get the right weight vs priority
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w := make(map[int]int)
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for _, serv := range services {
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weight := 100
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if serv.Weight != 0 {
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weight = serv.Weight
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}
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if _, ok := w[serv.Priority]; !ok {
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w[serv.Priority] = weight
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continue
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}
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w[serv.Priority] += weight
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}
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lookup := make(map[string]bool)
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for _, serv := range services {
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w1 := 100.0 / float64(w[serv.Priority])
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if serv.Weight == 0 {
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w1 *= 100
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} else {
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w1 *= float64(serv.Weight)
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}
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weight := uint16(math.Floor(w1))
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ip := net.ParseIP(serv.Host)
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switch {
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case ip == nil:
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srv := serv.NewSRV(state.QName(), weight)
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records = append(records, srv)
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if _, ok := lookup[srv.Target]; ok {
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break
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}
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lookup[srv.Target] = true
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if !dns.IsSubDomain(zone, srv.Target) {
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m1, e1 := e.Proxy.Lookup(state, srv.Target, dns.TypeA)
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if e1 == nil {
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extra = append(extra, m1.Answer...)
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}
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m1, e1 = e.Proxy.Lookup(state, srv.Target, dns.TypeAAAA)
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if e1 == nil {
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// If we have seen CNAME's we *assume* that they are already added.
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for _, a := range m1.Answer {
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if _, ok := a.(*dns.CNAME); !ok {
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extra = append(extra, a)
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}
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}
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}
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break
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}
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// Internal name, we should have some info on them, either v4 or v6
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// Clients expect a complete answer, because we are a recursor in their view.
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state1 := copyState(state, srv.Target, dns.TypeA)
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addr, debugAddr, e1 := e.A(zone, state1, nil, opt)
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if e1 == nil {
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extra = append(extra, addr...)
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debug = append(debug, debugAddr...)
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}
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// e.AAA(zone, state1, nil) as well...?
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case ip.To4() != nil:
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serv.Host = msg.Domain(serv.Key)
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srv := serv.NewSRV(state.QName(), weight)
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records = append(records, srv)
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extra = append(extra, serv.NewA(srv.Target, ip.To4()))
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case ip.To4() == nil:
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serv.Host = msg.Domain(serv.Key)
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srv := serv.NewSRV(state.QName(), weight)
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records = append(records, srv)
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extra = append(extra, serv.NewAAAA(srv.Target, ip.To16()))
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}
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}
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return records, extra, debug, nil
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}
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// MX returns MX records from etcd.
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// If the Target is not a name but an IP address, a name is created on the fly.
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func (e Etcd) MX(zone string, state middleware.State, opt Options) (records, extra []dns.RR, debug []msg.Service, err error) {
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services, debug, err := e.records(state, false, opt)
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if err != nil {
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return nil, nil, debug, err
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}
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lookup := make(map[string]bool)
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for _, serv := range services {
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if !serv.Mail {
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continue
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}
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ip := net.ParseIP(serv.Host)
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switch {
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case ip == nil:
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mx := serv.NewMX(state.QName())
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records = append(records, mx)
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if _, ok := lookup[mx.Mx]; ok {
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break
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}
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lookup[mx.Mx] = true
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if !dns.IsSubDomain(zone, mx.Mx) {
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m1, e1 := e.Proxy.Lookup(state, mx.Mx, dns.TypeA)
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if e1 == nil {
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extra = append(extra, m1.Answer...)
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}
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m1, e1 = e.Proxy.Lookup(state, mx.Mx, dns.TypeAAAA)
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if e1 == nil {
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// If we have seen CNAME's we *assume* that they are already added.
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for _, a := range m1.Answer {
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if _, ok := a.(*dns.CNAME); !ok {
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extra = append(extra, a)
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}
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}
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}
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break
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}
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// Internal name
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state1 := copyState(state, mx.Mx, dns.TypeA)
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addr, debugAddr, e1 := e.A(zone, state1, nil, opt)
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if e1 == nil {
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extra = append(extra, addr...)
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debug = append(debug, debugAddr...)
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}
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// e.AAAA as well
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case ip.To4() != nil:
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serv.Host = msg.Domain(serv.Key)
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records = append(records, serv.NewMX(state.QName()))
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extra = append(extra, serv.NewA(serv.Host, ip.To4()))
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case ip.To4() == nil:
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serv.Host = msg.Domain(serv.Key)
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records = append(records, serv.NewMX(state.QName()))
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extra = append(extra, serv.NewAAAA(serv.Host, ip.To16()))
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}
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}
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return records, extra, debug, nil
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}
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func (e Etcd) CNAME(zone string, state middleware.State, opt Options) (records []dns.RR, debug []msg.Service, err error) {
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services, debug, err := e.records(state, true, opt)
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if err != nil {
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return nil, debug, err
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}
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if len(services) > 0 {
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serv := services[0]
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if ip := net.ParseIP(serv.Host); ip == nil {
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records = append(records, serv.NewCNAME(state.QName(), serv.Host))
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}
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}
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return records, debug, nil
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}
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// PTR returns the PTR records, only services that have a domain name as host are included.
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func (e Etcd) PTR(zone string, state middleware.State, opt Options) (records []dns.RR, debug []msg.Service, err error) {
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services, debug, err := e.records(state, true, opt)
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if err != nil {
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return nil, debug, err
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}
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for _, serv := range services {
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if ip := net.ParseIP(serv.Host); ip == nil {
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records = append(records, serv.NewPTR(state.QName(), serv.Host))
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}
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}
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return records, debug, nil
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}
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func (e Etcd) TXT(zone string, state middleware.State, opt Options) (records []dns.RR, debug []msg.Service, err error) {
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services, debug, err := e.records(state, false, opt)
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if err != nil {
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return nil, debug, err
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}
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for _, serv := range services {
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if serv.Text == "" {
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continue
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}
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records = append(records, serv.NewTXT(state.QName()))
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}
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return records, debug, nil
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}
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func (e Etcd) NS(zone string, state middleware.State, opt Options) (records, extra []dns.RR, debug []msg.Service, err error) {
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// NS record for this zone live in a special place, ns.dns.<zone>. Fake our lookup.
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// only a tad bit fishy...
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old := state.QName()
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state.Clear()
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state.Req.Question[0].Name = "ns.dns." + zone
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services, debug, err := e.records(state, false, opt)
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if err != nil {
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return nil, nil, debug, err
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}
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// ... and reset
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state.Req.Question[0].Name = old
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for _, serv := range services {
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ip := net.ParseIP(serv.Host)
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switch {
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case ip == nil:
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return nil, nil, debug, fmt.Errorf("NS record must be an IP address: %s", serv.Host)
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case ip.To4() != nil:
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serv.Host = msg.Domain(serv.Key)
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records = append(records, serv.NewNS(state.QName()))
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extra = append(extra, serv.NewA(serv.Host, ip.To4()))
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case ip.To4() == nil:
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serv.Host = msg.Domain(serv.Key)
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records = append(records, serv.NewNS(state.QName()))
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extra = append(extra, serv.NewAAAA(serv.Host, ip.To16()))
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}
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}
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return records, extra, debug, nil
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}
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// SOA Record returns a SOA record.
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func (e Etcd) SOA(zone string, state middleware.State, opt Options) ([]dns.RR, []msg.Service, error) {
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header := dns.RR_Header{Name: zone, Rrtype: dns.TypeSOA, Ttl: 300, Class: dns.ClassINET}
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soa := &dns.SOA{Hdr: header,
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Mbox: "hostmaster." + zone,
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Ns: "ns.dns." + zone,
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Serial: uint32(time.Now().Unix()),
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Refresh: 7200,
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Retry: 1800,
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Expire: 86400,
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Minttl: 60,
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}
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// TODO(miek): fake some msg.Service here when returning.
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return []dns.RR{soa}, nil, nil
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}
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func isDuplicateCNAME(r *dns.CNAME, records []dns.RR) bool {
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for _, rec := range records {
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if v, ok := rec.(*dns.CNAME); ok {
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if v.Target == r.Target {
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return true
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}
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}
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}
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return false
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}
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// TODO(miek): Move to middleware?
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func copyState(state middleware.State, target string, typ uint16) middleware.State {
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state1 := middleware.State{W: state.W, Req: state.Req.Copy()}
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state1.Req.Question[0] = dns.Question{Name: dns.Fqdn(target), Qclass: dns.ClassINET, Qtype: typ}
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return state1
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}
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