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Merge branch 'master' into i18n

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This commit is contained in:
Hoàng Rio 2018-11-08 13:29:15 +07:00
commit 67c8abcb8e
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13 changed files with 955 additions and 114 deletions
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2
README.md
View File

@ -106,8 +106,10 @@ Settings are stored in [YAML format](https://en.wikipedia.org/wiki/YAML), possib
* `parental_enabled` — Parental control-based DNS requests filtering
* `parental_sensitivity` — Age group for parental control-based filtering, must be either 3, 10, 13 or 17
* `querylog_enabled` — Query logging (also used to calculate top 50 clients, blocked domains and requested domains for statistic purposes)
* `bootstrap_dns` — DNS server used for initial hostnames resolution in case if upstream is DoH or DoT with a hostname
* `upstream_dns` — List of upstream DNS servers
* `filters` — List of filters, each filter has the following values:
* `ID` - filter ID (must be unique)
* `url` — URL pointing to the filter contents (filtering rules)
* `enabled` — Current filter's status (enabled/disabled)
* `user_rules` — User-specified filtering rules

4
config.go
View File

@ -70,6 +70,7 @@ type coreDNSConfig struct {
Pprof string `yaml:"-"`
Cache string `yaml:"-"`
Prometheus string `yaml:"-"`
BootstrapDNS string `yaml:"bootstrap_dns"`
UpstreamDNS []string `yaml:"upstream_dns"`
}
@ -100,6 +101,7 @@ var config = configuration{
SafeBrowsingEnabled: false,
BlockedResponseTTL: 10, // in seconds
QueryLogEnabled: true,
BootstrapDNS: "8.8.8.8:53",
UpstreamDNS: defaultDNS,
Cache: "cache",
Prometheus: "prometheus :9153",
@ -253,7 +255,7 @@ const coreDNSConfigTemplate = `.:{{.Port}} {
hosts {
fallthrough
}
{{if .UpstreamDNS}}forward . {{range .UpstreamDNS}}{{.}} {{end}}{{end}}
{{if .UpstreamDNS}}upstream {{range .UpstreamDNS}}{{.}} {{end}} { bootstrap {{.BootstrapDNS}} }{{end}}
{{.Cache}}
{{.Prometheus}}
}

147
control.go
View File

@ -6,7 +6,6 @@ import (
"fmt"
"io/ioutil"
"log"
"net"
"net/http"
"os"
"path/filepath"
@ -15,8 +14,9 @@ import (
"strings"
"time"
"github.com/AdguardTeam/AdGuardHome/upstream"
corednsplugin "github.com/AdguardTeam/AdGuardHome/coredns_plugin"
"github.com/miekg/dns"
"gopkg.in/asaskevich/govalidator.v4"
)
@ -81,6 +81,7 @@ func handleStatus(w http.ResponseWriter, r *http.Request) {
"protection_enabled": config.CoreDNS.ProtectionEnabled,
"querylog_enabled": config.CoreDNS.QueryLogEnabled,
"running": isRunning(),
"bootstrap_dns": config.CoreDNS.BootstrapDNS,
"upstream_dns": config.CoreDNS.UpstreamDNS,
"version": VersionString,
}
@ -134,17 +135,14 @@ func httpError(w http.ResponseWriter, code int, format string, args ...interface
func handleSetUpstreamDNS(w http.ResponseWriter, r *http.Request) {
body, err := ioutil.ReadAll(r.Body)
if err != nil {
errortext := fmt.Sprintf("Failed to read request body: %s", err)
log.Println(errortext)
http.Error(w, errortext, http.StatusBadRequest)
errorText := fmt.Sprintf("Failed to read request body: %s", err)
log.Println(errorText)
http.Error(w, errorText, http.StatusBadRequest)
return
}
// if empty body -- user is asking for default servers
hosts, err := sanitiseDNSServers(string(body))
if err != nil {
httpError(w, http.StatusBadRequest, "Invalid DNS servers were given: %s", err)
return
}
hosts := strings.Fields(string(body))
if len(hosts) == 0 {
config.CoreDNS.UpstreamDNS = defaultDNS
} else {
@ -153,34 +151,34 @@ func handleSetUpstreamDNS(w http.ResponseWriter, r *http.Request) {
err = writeAllConfigs()
if err != nil {
errortext := fmt.Sprintf("Couldn't write config file: %s", err)
log.Println(errortext)
http.Error(w, errortext, http.StatusInternalServerError)
errorText := fmt.Sprintf("Couldn't write config file: %s", err)
log.Println(errorText)
http.Error(w, errorText, http.StatusInternalServerError)
return
}
tellCoreDNSToReload()
_, err = fmt.Fprintf(w, "OK %d servers\n", len(hosts))
if err != nil {
errortext := fmt.Sprintf("Couldn't write body: %s", err)
log.Println(errortext)
http.Error(w, errortext, http.StatusInternalServerError)
errorText := fmt.Sprintf("Couldn't write body: %s", err)
log.Println(errorText)
http.Error(w, errorText, http.StatusInternalServerError)
}
}
func handleTestUpstreamDNS(w http.ResponseWriter, r *http.Request) {
body, err := ioutil.ReadAll(r.Body)
if err != nil {
errortext := fmt.Sprintf("Failed to read request body: %s", err)
log.Println(errortext)
http.Error(w, errortext, 400)
errorText := fmt.Sprintf("Failed to read request body: %s", err)
log.Println(errorText)
http.Error(w, errorText, 400)
return
}
hosts := strings.Fields(string(body))
if len(hosts) == 0 {
errortext := fmt.Sprintf("No servers specified")
log.Println(errortext)
http.Error(w, errortext, http.StatusBadRequest)
errorText := fmt.Sprintf("No servers specified")
log.Println(errorText)
http.Error(w, errorText, http.StatusBadRequest)
return
}
@ -198,120 +196,43 @@ func handleTestUpstreamDNS(w http.ResponseWriter, r *http.Request) {
jsonVal, err := json.Marshal(result)
if err != nil {
errortext := fmt.Sprintf("Unable to marshal status json: %s", err)
log.Println(errortext)
http.Error(w, errortext, http.StatusInternalServerError)
errorText := fmt.Sprintf("Unable to marshal status json: %s", err)
log.Println(errorText)
http.Error(w, errorText, http.StatusInternalServerError)
return
}
w.Header().Set("Content-Type", "application/json")
_, err = w.Write(jsonVal)
if err != nil {
errortext := fmt.Sprintf("Couldn't write body: %s", err)
log.Println(errortext)
http.Error(w, errortext, http.StatusInternalServerError)
errorText := fmt.Sprintf("Couldn't write body: %s", err)
log.Println(errorText)
http.Error(w, errorText, http.StatusInternalServerError)
}
}
func checkDNS(input string) error {
input, err := sanitizeDNSServer(input)
u, err := upstream.NewUpstream(input, config.CoreDNS.BootstrapDNS)
if err != nil {
return err
}
defer u.Close()
req := dns.Msg{}
req.Id = dns.Id()
req.RecursionDesired = true
req.Question = []dns.Question{
{Name: "google-public-dns-a.google.com.", Qtype: dns.TypeA, Qclass: dns.ClassINET},
}
alive, err := upstream.IsAlive(u)
prefix, host := splitDNSServerPrefixServer(input)
c := dns.Client{
Timeout: time.Minute,
}
switch prefix {
case "tls://":
c.Net = "tcp-tls"
}
resp, rtt, err := c.Exchange(&req, host)
if err != nil {
return fmt.Errorf("couldn't communicate with DNS server %s: %s", input, err)
}
trace("exchange with %s took %v", input, rtt)
if len(resp.Answer) != 1 {
return fmt.Errorf("DNS server %s returned wrong answer", input)
}
if t, ok := resp.Answer[0].(*dns.A); ok {
if !net.IPv4(8, 8, 8, 8).Equal(t.A) {
return fmt.Errorf("DNS server %s returned wrong answer: %v", input, t.A)
}
if !alive {
return fmt.Errorf("DNS server has not passed the healthcheck: %s", input)
}
return nil
}
func sanitiseDNSServers(input string) ([]string, error) {
fields := strings.Fields(input)
hosts := make([]string, 0)
for _, field := range fields {
sanitized, err := sanitizeDNSServer(field)
if err != nil {
return hosts, err
}
hosts = append(hosts, sanitized)
}
return hosts, nil
}
func getDNSServerPrefix(input string) string {
prefix := ""
switch {
case strings.HasPrefix(input, "dns://"):
prefix = "dns://"
case strings.HasPrefix(input, "tls://"):
prefix = "tls://"
}
return prefix
}
func splitDNSServerPrefixServer(input string) (string, string) {
prefix := getDNSServerPrefix(input)
host := strings.TrimPrefix(input, prefix)
return prefix, host
}
func sanitizeDNSServer(input string) (string, error) {
prefix, host := splitDNSServerPrefixServer(input)
host = appendPortIfMissing(prefix, host)
{
h, _, err := net.SplitHostPort(host)
if err != nil {
return "", err
}
ip := net.ParseIP(h)
if ip == nil {
return "", fmt.Errorf("invalid DNS server field: %s", h)
}
}
return prefix + host, nil
}
func appendPortIfMissing(prefix, input string) string {
port := "53"
switch prefix {
case "tls://":
port = "853"
}
_, _, err := net.SplitHostPort(input)
if err == nil {
return input
}
return net.JoinHostPort(input, port)
}
//noinspection GoUnusedParameter
func handleGetVersionJSON(w http.ResponseWriter, r *http.Request) {
now := time.Now()

2
coredns.go
View File

@ -8,6 +8,7 @@ import (
"sync" // Include all plugins.
_ "github.com/AdguardTeam/AdGuardHome/coredns_plugin"
_ "github.com/AdguardTeam/AdGuardHome/upstream"
"github.com/coredns/coredns/core/dnsserver"
"github.com/coredns/coredns/coremain"
_ "github.com/coredns/coredns/plugin/auto"
@ -79,6 +80,7 @@ var directives = []string{
"loop",
"forward",
"proxy",
"upstream",
"erratic",
"whoami",
"on",

1
openapi.yaml
View File

@ -41,6 +41,7 @@ paths:
protection_enabled: true
querylog_enabled: true
running: true
bootstrap_dns: 8.8.8.8:53
upstream_dns:
- 1.1.1.1
- 1.0.0.1

109
upstream/dns_upstream.go Normal file
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@ -0,0 +1,109 @@
package upstream
import (
"crypto/tls"
"time"
"github.com/miekg/dns"
"golang.org/x/net/context"
)
// DnsUpstream is a very simple upstream implementation for plain DNS
type DnsUpstream struct {
endpoint string // IP:port
timeout time.Duration // Max read and write timeout
proto string // Protocol (tcp, tcp-tls, or udp)
transport *Transport // Persistent connections cache
}
// NewDnsUpstream creates a new DNS upstream
func NewDnsUpstream(endpoint string, proto string, tlsServerName string) (Upstream, error) {
u := &DnsUpstream{
endpoint: endpoint,
timeout: defaultTimeout,
proto: proto,
}
var tlsConfig *tls.Config
if proto == "tcp-tls" {
tlsConfig = new(tls.Config)
tlsConfig.ServerName = tlsServerName
}
// Initialize the connections cache
u.transport = NewTransport(endpoint)
u.transport.tlsConfig = tlsConfig
u.transport.Start()
return u, nil
}
// Exchange provides an implementation for the Upstream interface
func (u *DnsUpstream) Exchange(ctx context.Context, query *dns.Msg) (*dns.Msg, error) {
resp, err := u.exchange(u.proto, query)
// Retry over TCP if response is truncated
if err == dns.ErrTruncated && u.proto == "udp" {
resp, err = u.exchange("tcp", query)
} else if err == dns.ErrTruncated && resp != nil {
// Reassemble something to be sent to client
m := new(dns.Msg)
m.SetReply(query)
m.Truncated = true
m.Authoritative = true
m.Rcode = dns.RcodeSuccess
return m, nil
}
if err != nil {
resp = &dns.Msg{}
resp.SetRcode(resp, dns.RcodeServerFailure)
}
return resp, err
}
// Clear resources
func (u *DnsUpstream) Close() error {
// Close active connections
u.transport.Stop()
return nil
}
// Performs a synchronous query. It sends the message m via the conn
// c and waits for a reply. The conn c is not closed.
func (u *DnsUpstream) exchange(proto string, query *dns.Msg) (r *dns.Msg, err error) {
// Establish a connection if needed (or reuse cached)
conn, err := u.transport.Dial(proto)
if err != nil {
return nil, err
}
// Write the request with a timeout
conn.SetWriteDeadline(time.Now().Add(u.timeout))
if err = conn.WriteMsg(query); err != nil {
conn.Close() // Not giving it back
return nil, err
}
// Write response with a timeout
conn.SetReadDeadline(time.Now().Add(u.timeout))
r, err = conn.ReadMsg()
if err != nil {
conn.Close() // Not giving it back
} else if err == nil && r.Id != query.Id {
err = dns.ErrId
conn.Close() // Not giving it back
}
if err == nil {
// Return it back to the connections cache if there were no errors
u.transport.Yield(conn)
}
return r, err
}

101
upstream/helpers.go Normal file
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@ -0,0 +1,101 @@
package upstream
import (
"net"
"strings"
"github.com/miekg/dns"
"golang.org/x/net/context"
)
// Detects the upstream type from the specified url and creates a proper Upstream object
func NewUpstream(url string, bootstrap string) (Upstream, error) {
proto := "udp"
prefix := ""
switch {
case strings.HasPrefix(url, "tcp://"):
proto = "tcp"
prefix = "tcp://"
case strings.HasPrefix(url, "tls://"):
proto = "tcp-tls"
prefix = "tls://"
case strings.HasPrefix(url, "https://"):
return NewHttpsUpstream(url, bootstrap)
}
hostname := strings.TrimPrefix(url, prefix)
host, port, err := net.SplitHostPort(hostname)
if err != nil {
// Set port depending on the protocol
switch proto {
case "udp":
port = "53"
case "tcp":
port = "53"
case "tcp-tls":
port = "853"
}
// Set host = hostname
host = hostname
}
// Try to resolve the host address (or check if it's an IP address)
bootstrapResolver := CreateResolver(bootstrap)
ips, err := bootstrapResolver.LookupIPAddr(context.Background(), host)
if err != nil || len(ips) == 0 {
return nil, err
}
addr := ips[0].String()
endpoint := net.JoinHostPort(addr, port)
tlsServerName := ""
if proto == "tcp-tls" && host != addr {
// Check if we need to specify TLS server name
tlsServerName = host
}
return NewDnsUpstream(endpoint, proto, tlsServerName)
}
func CreateResolver(bootstrap string) *net.Resolver {
bootstrapResolver := net.DefaultResolver
if bootstrap != "" {
bootstrapResolver = &net.Resolver{
PreferGo: true,
Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
var d net.Dialer
return d.DialContext(ctx, network, bootstrap)
},
}
}
return bootstrapResolver
}
// Performs a simple health-check of the specified upstream
func IsAlive(u Upstream) (bool, error) {
// Using ipv4only.arpa. domain as it is a part of DNS64 RFC and it should exist everywhere
ping := new(dns.Msg)
ping.SetQuestion("ipv4only.arpa.", dns.TypeA)
resp, err := u.Exchange(context.Background(), ping)
// If we got a header, we're alright, basically only care about I/O errors 'n stuff.
if err != nil && resp != nil {
// Silly check, something sane came back.
if resp.Rcode != dns.RcodeServerFailure {
err = nil
}
}
return err == nil, err
}

128
upstream/https_upstream.go Normal file
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@ -0,0 +1,128 @@
package upstream
import (
"bytes"
"crypto/tls"
"fmt"
"io/ioutil"
"log"
"net"
"net/http"
"net/url"
"time"
"github.com/miekg/dns"
"github.com/pkg/errors"
"golang.org/x/net/context"
"golang.org/x/net/http2"
)
const (
dnsMessageContentType = "application/dns-message"
defaultKeepAlive = 30 * time.Second
)
// HttpsUpstream is the upstream implementation for DNS-over-HTTPS
type HttpsUpstream struct {
client *http.Client
endpoint *url.URL
}
// NewHttpsUpstream creates a new DNS-over-HTTPS upstream from the specified url
func NewHttpsUpstream(endpoint string, bootstrap string) (Upstream, error) {
u, err := url.Parse(endpoint)
if err != nil {
return nil, err
}
// Initialize bootstrap resolver
bootstrapResolver := CreateResolver(bootstrap)
dialer := &net.Dialer{
Timeout: defaultTimeout,
KeepAlive: defaultKeepAlive,
DualStack: true,
Resolver: bootstrapResolver,
}
// Update TLS and HTTP client configuration
tlsConfig := &tls.Config{ServerName: u.Hostname()}
transport := &http.Transport{
TLSClientConfig: tlsConfig,
DisableCompression: true,
MaxIdleConns: 1,
DialContext: dialer.DialContext,
}
http2.ConfigureTransport(transport)
client := &http.Client{
Timeout: defaultTimeout,
Transport: transport,
}
return &HttpsUpstream{client: client, endpoint: u}, nil
}
// Exchange provides an implementation for the Upstream interface
func (u *HttpsUpstream) Exchange(ctx context.Context, query *dns.Msg) (*dns.Msg, error) {
queryBuf, err := query.Pack()
if err != nil {
return nil, errors.Wrap(err, "failed to pack DNS query")
}
// No content negotiation for now, use DNS wire format
buf, backendErr := u.exchangeWireformat(queryBuf)
if backendErr == nil {
response := &dns.Msg{}
if err := response.Unpack(buf); err != nil {
return nil, errors.Wrap(err, "failed to unpack DNS response from body")
}
response.Id = query.Id
return response, nil
}
log.Printf("failed to connect to an HTTPS backend %q due to %s", u.endpoint, backendErr)
return nil, backendErr
}
// Perform message exchange with the default UDP wireformat defined in current draft
// https://tools.ietf.org/html/draft-ietf-doh-dns-over-https-10
func (u *HttpsUpstream) exchangeWireformat(msg []byte) ([]byte, error) {
req, err := http.NewRequest("POST", u.endpoint.String(), bytes.NewBuffer(msg))
if err != nil {
return nil, errors.Wrap(err, "failed to create an HTTPS request")
}
req.Header.Add("Content-Type", dnsMessageContentType)
req.Header.Add("Accept", dnsMessageContentType)
req.Host = u.endpoint.Hostname()
resp, err := u.client.Do(req)
if err != nil {
return nil, errors.Wrap(err, "failed to perform an HTTPS request")
}
// Check response status code
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return nil, fmt.Errorf("returned status code %d", resp.StatusCode)
}
contentType := resp.Header.Get("Content-Type")
if contentType != dnsMessageContentType {
return nil, fmt.Errorf("return wrong content type %s", contentType)
}
// Read application/dns-message response from the body
buf, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, errors.Wrap(err, "failed to read the response body")
}
return buf, nil
}
// Clear resources
func (u *HttpsUpstream) Close() error {
return nil
}

210
upstream/persistent.go Normal file
View File

@ -0,0 +1,210 @@
package upstream
import (
"crypto/tls"
"net"
"sort"
"sync/atomic"
"time"
"github.com/miekg/dns"
)
// Persistent connections cache -- almost similar to the same used in the CoreDNS forward plugin
const (
defaultExpire = 10 * time.Second
minDialTimeout = 100 * time.Millisecond
maxDialTimeout = 30 * time.Second
defaultDialTimeout = 30 * time.Second
cumulativeAvgWeight = 4
)
// a persistConn hold the dns.Conn and the last used time.
type persistConn struct {
c *dns.Conn
used time.Time
}
// Transport hold the persistent cache.
type Transport struct {
avgDialTime int64 // kind of average time of dial time
conns map[string][]*persistConn // Buckets for udp, tcp and tcp-tls.
expire time.Duration // After this duration a connection is expired.
addr string
tlsConfig *tls.Config
dial chan string
yield chan *dns.Conn
ret chan *dns.Conn
stop chan bool
}
// Dial dials the address configured in transport, potentially reusing a connection or creating a new one.
func (t *Transport) Dial(proto string) (*dns.Conn, error) {
// If tls has been configured; use it.
if t.tlsConfig != nil {
proto = "tcp-tls"
}
t.dial <- proto
c := <-t.ret
if c != nil {
return c, nil
}
reqTime := time.Now()
timeout := t.dialTimeout()
if proto == "tcp-tls" {
conn, err := dns.DialTimeoutWithTLS(proto, t.addr, t.tlsConfig, timeout)
t.updateDialTimeout(time.Since(reqTime))
return conn, err
}
conn, err := dns.DialTimeout(proto, t.addr, timeout)
t.updateDialTimeout(time.Since(reqTime))
return conn, err
}
// Yield return the connection to transport for reuse.
func (t *Transport) Yield(c *dns.Conn) { t.yield <- c }
// Start starts the transport's connection manager.
func (t *Transport) Start() { go t.connManager() }
// Stop stops the transport's connection manager.
func (t *Transport) Stop() { close(t.stop) }
// SetExpire sets the connection expire time in transport.
func (t *Transport) SetExpire(expire time.Duration) { t.expire = expire }
// SetTLSConfig sets the TLS config in transport.
func (t *Transport) SetTLSConfig(cfg *tls.Config) { t.tlsConfig = cfg }
func NewTransport(addr string) *Transport {
t := &Transport{
avgDialTime: int64(defaultDialTimeout / 2),
conns: make(map[string][]*persistConn),
expire: defaultExpire,
addr: addr,
dial: make(chan string),
yield: make(chan *dns.Conn),
ret: make(chan *dns.Conn),
stop: make(chan bool),
}
return t
}
func averageTimeout(currentAvg *int64, observedDuration time.Duration, weight int64) {
dt := time.Duration(atomic.LoadInt64(currentAvg))
atomic.AddInt64(currentAvg, int64(observedDuration-dt)/weight)
}
func (t *Transport) dialTimeout() time.Duration {
return limitTimeout(&t.avgDialTime, minDialTimeout, maxDialTimeout)
}
func (t *Transport) updateDialTimeout(newDialTime time.Duration) {
averageTimeout(&t.avgDialTime, newDialTime, cumulativeAvgWeight)
}
// limitTimeout is a utility function to auto-tune timeout values
// average observed time is moved towards the last observed delay moderated by a weight
// next timeout to use will be the double of the computed average, limited by min and max frame.
func limitTimeout(currentAvg *int64, minValue time.Duration, maxValue time.Duration) time.Duration {
rt := time.Duration(atomic.LoadInt64(currentAvg))
if rt < minValue {
return minValue
}
if rt < maxValue/2 {
return 2 * rt
}
return maxValue
}
// connManagers manages the persistent connection cache for UDP and TCP.
func (t *Transport) connManager() {
ticker := time.NewTicker(t.expire)
Wait:
for {
select {
case proto := <-t.dial:
// take the last used conn - complexity O(1)
if stack := t.conns[proto]; len(stack) > 0 {
pc := stack[len(stack)-1]
if time.Since(pc.used) < t.expire {
// Found one, remove from pool and return this conn.
t.conns[proto] = stack[:len(stack)-1]
t.ret <- pc.c
continue Wait
}
// clear entire cache if the last conn is expired
t.conns[proto] = nil
// now, the connections being passed to closeConns() are not reachable from
// transport methods anymore. So, it's safe to close them in a separate goroutine
go closeConns(stack)
}
t.ret <- nil
case conn := <-t.yield:
// no proto here, infer from config and conn
if _, ok := conn.Conn.(*net.UDPConn); ok {
t.conns["udp"] = append(t.conns["udp"], &persistConn{conn, time.Now()})
continue Wait
}
if t.tlsConfig == nil {
t.conns["tcp"] = append(t.conns["tcp"], &persistConn{conn, time.Now()})
continue Wait
}
t.conns["tcp-tls"] = append(t.conns["tcp-tls"], &persistConn{conn, time.Now()})
case <-ticker.C:
t.cleanup(false)
case <-t.stop:
t.cleanup(true)
close(t.ret)
return
}
}
}
// closeConns closes connections.
func closeConns(conns []*persistConn) {
for _, pc := range conns {
pc.c.Close()
}
}
// cleanup removes connections from cache.
func (t *Transport) cleanup(all bool) {
staleTime := time.Now().Add(-t.expire)
for proto, stack := range t.conns {
if len(stack) == 0 {
continue
}
if all {
t.conns[proto] = nil
// now, the connections being passed to closeConns() are not reachable from
// transport methods anymore. So, it's safe to close them in a separate goroutine
go closeConns(stack)
continue
}
if stack[0].used.After(staleTime) {
continue
}
// connections in stack are sorted by "used"
good := sort.Search(len(stack), func(i int) bool {
return stack[i].used.After(staleTime)
})
t.conns[proto] = stack[good:]
// now, the connections being passed to closeConns() are not reachable from
// transport methods anymore. So, it's safe to close them in a separate goroutine
go closeConns(stack[:good])
}
}

84
upstream/setup.go Normal file
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package upstream
import (
"log"
"github.com/coredns/coredns/core/dnsserver"
"github.com/coredns/coredns/plugin"
"github.com/mholt/caddy"
)
func init() {
caddy.RegisterPlugin("upstream", caddy.Plugin{
ServerType: "dns",
Action: setup,
})
}
// Read the configuration and initialize upstreams
func setup(c *caddy.Controller) error {
p, err := setupPlugin(c)
if err != nil {
return err
}
config := dnsserver.GetConfig(c)
config.AddPlugin(func(next plugin.Handler) plugin.Handler {
p.Next = next
return p
})
c.OnShutdown(p.onShutdown)
return nil
}
// Read the configuration
func setupPlugin(c *caddy.Controller) (*UpstreamPlugin, error) {
p := New()
log.Println("Initializing the Upstream plugin")
bootstrap := ""
upstreamUrls := []string{}
for c.Next() {
args := c.RemainingArgs()
if len(args) > 0 {
upstreamUrls = append(upstreamUrls, args...)
}
for c.NextBlock() {
switch c.Val() {
case "bootstrap":
if !c.NextArg() {
return nil, c.ArgErr()
}
bootstrap = c.Val()
}
}
}
for _, url := range upstreamUrls {
u, err := NewUpstream(url, bootstrap)
if err != nil {
log.Printf("Cannot initialize upstream %s", url)
return nil, err
}
p.Upstreams = append(p.Upstreams, u)
}
return p, nil
}
func (p *UpstreamPlugin) onShutdown() error {
for i := range p.Upstreams {
u := p.Upstreams[i]
err := u.Close()
if err != nil {
log.Printf("Error while closing the upstream: %s", err)
}
}
return nil
}

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upstream/setup_test.go Normal file
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package upstream
import (
"testing"
"github.com/mholt/caddy"
)
func TestSetup(t *testing.T) {
var tests = []struct {
config string
}{
{`upstream 8.8.8.8`},
{`upstream 8.8.8.8 {
bootstrap 8.8.8.8:53
}`},
{`upstream tls://1.1.1.1 8.8.8.8 {
bootstrap 1.1.1.1
}`},
}
for _, test := range tests {
c := caddy.NewTestController("dns", test.config)
err := setup(c)
if err != nil {
t.Fatalf("Test failed")
}
}
}

57
upstream/upstream.go Normal file
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package upstream
import (
"time"
"github.com/coredns/coredns/plugin"
"github.com/miekg/dns"
"github.com/pkg/errors"
"golang.org/x/net/context"
)
const (
defaultTimeout = 5 * time.Second
)
// Upstream is a simplified interface for proxy destination
type Upstream interface {
Exchange(ctx context.Context, query *dns.Msg) (*dns.Msg, error)
Close() error
}
// UpstreamPlugin is a simplified DNS proxy using a generic upstream interface
type UpstreamPlugin struct {
Upstreams []Upstream
Next plugin.Handler
}
// Initialize the upstream plugin
func New() *UpstreamPlugin {
p := &UpstreamPlugin{
Upstreams: []Upstream{},
}
return p
}
// ServeDNS implements interface for CoreDNS plugin
func (p *UpstreamPlugin) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
var reply *dns.Msg
var backendErr error
for i := range p.Upstreams {
upstream := p.Upstreams[i]
reply, backendErr = upstream.Exchange(ctx, r)
if backendErr == nil {
w.WriteMsg(reply)
return 0, nil
}
}
return dns.RcodeServerFailure, errors.Wrap(backendErr, "failed to contact any of the upstreams")
}
// Name implements interface for CoreDNS plugin
func (p *UpstreamPlugin) Name() string {
return "upstream"
}

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upstream/upstream_test.go Normal file
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package upstream
import (
"net"
"testing"
"github.com/miekg/dns"
"golang.org/x/net/context"
)
func TestDnsUpstreamIsAlive(t *testing.T) {
var tests = []struct {
url string
bootstrap string
}{
{"8.8.8.8:53", "8.8.8.8:53"},
{"1.1.1.1", ""},
{"tcp://1.1.1.1:53", ""},
{"176.103.130.130:5353", ""},
}
for _, test := range tests {
u, err := NewUpstream(test.url, test.bootstrap)
if err != nil {
t.Errorf("cannot create a DNS upstream")
}
testUpstreamIsAlive(t, u)
}
}
func TestHttpsUpstreamIsAlive(t *testing.T) {
var tests = []struct {
url string
bootstrap string
}{
{"https://cloudflare-dns.com/dns-query", "8.8.8.8:53"},
{"https://dns.google.com/experimental", "8.8.8.8:53"},
{"https://doh.cleanbrowsing.org/doh/security-filter/", ""},
}
for _, test := range tests {
u, err := NewUpstream(test.url, test.bootstrap)
if err != nil {
t.Errorf("cannot create a DNS-over-HTTPS upstream")
}
testUpstreamIsAlive(t, u)
}
}
func TestDnsOverTlsIsAlive(t *testing.T) {
var tests = []struct {
url string
bootstrap string
}{
{"tls://1.1.1.1", ""},
{"tls://9.9.9.9:853", ""},
{"tls://security-filter-dns.cleanbrowsing.org", "8.8.8.8:53"},
{"tls://adult-filter-dns.cleanbrowsing.org:853", "8.8.8.8:53"},
}
for _, test := range tests {
u, err := NewUpstream(test.url, test.bootstrap)
if err != nil {
t.Errorf("cannot create a DNS-over-TLS upstream")
}
testUpstreamIsAlive(t, u)
}
}
func TestDnsUpstream(t *testing.T) {
var tests = []struct {
url string
bootstrap string
}{
{"8.8.8.8:53", "8.8.8.8:53"},
{"1.1.1.1", ""},
{"tcp://1.1.1.1:53", ""},
{"176.103.130.130:5353", ""},
}
for _, test := range tests {
u, err := NewUpstream(test.url, test.bootstrap)
if err != nil {
t.Errorf("cannot create a DNS upstream")
}
testUpstream(t, u)
}
}
func TestHttpsUpstream(t *testing.T) {
var tests = []struct {
url string
bootstrap string
}{
{"https://cloudflare-dns.com/dns-query", "8.8.8.8:53"},
{"https://dns.google.com/experimental", "8.8.8.8:53"},
{"https://doh.cleanbrowsing.org/doh/security-filter/", ""},
}
for _, test := range tests {
u, err := NewUpstream(test.url, test.bootstrap)
if err != nil {
t.Errorf("cannot create a DNS-over-HTTPS upstream")
}
testUpstream(t, u)
}
}
func TestDnsOverTlsUpstream(t *testing.T) {
var tests = []struct {
url string
bootstrap string
}{
{"tls://1.1.1.1", ""},
{"tls://9.9.9.9:853", ""},
{"tls://security-filter-dns.cleanbrowsing.org", "8.8.8.8:53"},
{"tls://adult-filter-dns.cleanbrowsing.org:853", "8.8.8.8:53"},
}
for _, test := range tests {
u, err := NewUpstream(test.url, test.bootstrap)
if err != nil {
t.Errorf("cannot create a DNS-over-TLS upstream")
}
testUpstream(t, u)
}
}
func testUpstreamIsAlive(t *testing.T, u Upstream) {
alive, err := IsAlive(u)
if !alive || err != nil {
t.Errorf("Upstream is not alive")
}
u.Close()
}
func testUpstream(t *testing.T, u Upstream) {
var tests = []struct {
name string
expected net.IP
}{
{"google-public-dns-a.google.com.", net.IPv4(8, 8, 8, 8)},
{"google-public-dns-b.google.com.", net.IPv4(8, 8, 4, 4)},
}
for _, test := range tests {
req := dns.Msg{}
req.Id = dns.Id()
req.RecursionDesired = true
req.Question = []dns.Question{
{Name: test.name, Qtype: dns.TypeA, Qclass: dns.ClassINET},
}
resp, err := u.Exchange(context.Background(), &req)
if err != nil {
t.Errorf("error while making an upstream request: %s", err)
}
if len(resp.Answer) != 1 {
t.Errorf("no answer section in the response")
}
if answer, ok := resp.Answer[0].(*dns.A); ok {
if !test.expected.Equal(answer.A) {
t.Errorf("wrong IP in the response: %v", answer.A)
}
}
}
err := u.Close()
if err != nil {
t.Errorf("Error while closing the upstream: %s", err)
}
}