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Pull request: 4517 domain specific test

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Merge in DNS/adguard-home from 4517-domain-specific-test to master

Updates #4517.

Squashed commit of the following:

commit 03a803f831749a060923ec966592696f99591786
Merge: 8ea24170 f5959a0d
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Fri Jul 29 19:17:28 2022 +0300

    Merge branch 'master' into 4517-domain-specific-test

commit 8ea2417036547996bb2d39b75b0ff31de4fe9b21
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Fri Jul 29 18:44:26 2022 +0300

    all: log changes, imp docs

commit aa74c8be64f2796a2dfa7166f0155fff5bb395b6
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Fri Jul 29 18:07:12 2022 +0300

    dnsforward: imp logging

commit 02dccca4e7d766bbfbe0826933e8be70fcd93f58
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Fri Jul 29 17:24:08 2022 +0300

    all: imp code, docs

commit 3b21067d07b208baf574a34fb06ec808b37c4ee3
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Fri Jul 29 13:34:55 2022 +0300

    client: add warning toast

commit ea2272dc77f87e34dc6aff0af99c7a51a04e3770
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Jul 28 20:11:55 2022 +0300

    dnsforward: imp err msg, docs

commit fd9ee82afef9d93961c30ebafcc7a11d984247b5
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Jul 28 19:24:58 2022 +0300

    dnsforward: test doain specific upstreams

commit 9a83ebfa7a73bf4e03eaf1ff4a33f79771159fc7
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Jul 28 18:22:49 2022 +0300

    dnsforward: merge some logic
This commit is contained in:
Eugene Burkov
2022-07-29 19:27:15 +03:00
parent f5959a0dc6
commit f32da12a86
5 changed files with 151 additions and 168 deletions
Download Patch File Download Diff File Expand all files Collapse all files

156
internal/dnsforward/http.go
View File

@@ -363,6 +363,21 @@ func newUpstreamConfig(upstreams []string) (conf *proxy.UpstreamConfig, err erro
return nil, nil
}
for _, u := range upstreams {
var ups string
var domains []string
ups, domains, err = separateUpstream(u)
if err != nil {
// Don't wrap the error since it's informative enough as is.
return nil, err
}
_, err = validateUpstream(ups, domains)
if err != nil {
return nil, fmt.Errorf("validating upstream %q: %w", u, err)
}
}
conf, err = proxy.ParseUpstreamsConfig(
upstreams,
&upstream.Options{Bootstrap: []string{}, Timeout: DefaultTimeout},
@@ -373,13 +388,6 @@ func newUpstreamConfig(upstreams []string) (conf *proxy.UpstreamConfig, err erro
return nil, errors.Error("no default upstreams specified")
}
for _, u := range upstreams {
_, err = validateUpstream(u)
if err != nil {
return nil, err
}
}
return conf, nil
}
@@ -449,16 +457,14 @@ func ValidateUpstreamsPrivate(upstreams []string, privateNets netutil.SubnetSet)
var protocols = []string{"udp://", "tcp://", "tls://", "https://", "sdns://", "quic://"}
func validateUpstream(u string) (useDefault bool, err error) {
// Check if the user tries to specify upstream for domain.
var isDomainSpec bool
u, isDomainSpec, err = separateUpstream(u)
if err != nil {
return !isDomainSpec, err
}
// validateUpstream returns an error if u alongside with domains is not a valid
// upstream configuration. useDefault is true if the upstream is
// domain-specific and is configured to point at the default upstream server
// which is validated separately. The upstream is considered domain-specific
// only if domains is at least not nil.
func validateUpstream(u string, domains []string) (useDefault bool, err error) {
// The special server address '#' means that default server must be used.
if useDefault = !isDomainSpec; u == "#" && isDomainSpec {
if useDefault = u == "#" && domains != nil; useDefault {
return useDefault, nil
}
@@ -485,12 +491,14 @@ func validateUpstream(u string) (useDefault bool, err error) {
return useDefault, nil
}
// separateUpstream returns the upstream without the specified domains.
// isDomainSpec is true when the upstream is domains-specific.
func separateUpstream(upstreamStr string) (upstream string, isDomainSpec bool, err error) {
// separateUpstream returns the upstream and the specified domains. domains is
// nil when the upstream is not domains-specific. Otherwise it may also be
// empty.
func separateUpstream(upstreamStr string) (ups string, domains []string, err error) {
if !strings.HasPrefix(upstreamStr, "[/") {
return upstreamStr, false, nil
return upstreamStr, nil, nil
}
defer func() { err = errors.Annotate(err, "bad upstream for domain %q: %w", upstreamStr) }()
parts := strings.Split(upstreamStr[2:], "/]")
@@ -498,40 +506,46 @@ func separateUpstream(upstreamStr string) (upstream string, isDomainSpec bool, e
case 2:
// Go on.
case 1:
return "", false, errors.Error("missing separator")
return "", nil, errors.Error("missing separator")
default:
return "", true, errors.Error("duplicated separator")
return "", []string{}, errors.Error("duplicated separator")
}
var domains string
domains, upstream = parts[0], parts[1]
for i, host := range strings.Split(domains, "/") {
for i, host := range strings.Split(parts[0], "/") {
if host == "" {
continue
}
host = strings.TrimPrefix(host, "*.")
err = netutil.ValidateDomainName(host)
err = netutil.ValidateDomainName(strings.TrimPrefix(host, "*."))
if err != nil {
return "", true, fmt.Errorf("domain at index %d: %w", i, err)
return "", domains, fmt.Errorf("domain at index %d: %w", i, err)
}
domains = append(domains, host)
}
return upstream, true, nil
return parts[1], domains, nil
}
// excFunc is a signature of function to check if upstream exchanges correctly.
type excFunc func(u upstream.Upstream) (err error)
// healthCheckFunc is a signature of function to check if upstream exchanges
// properly.
type healthCheckFunc func(u upstream.Upstream) (err error)
// checkDNSUpstreamExc checks if the DNS upstream exchanges correctly.
func checkDNSUpstreamExc(u upstream.Upstream) (err error) {
// testTLD is the special-use fully-qualified domain name for testing the
// DNS server reachability.
//
// See https://datatracker.ietf.org/doc/html/rfc6761#section-6.2.
const testTLD = "test."
req := &dns.Msg{
MsgHdr: dns.MsgHdr{
Id: dns.Id(),
RecursionDesired: true,
},
Question: []dns.Question{{
Name: "google-public-dns-a.google.com.",
Name: testTLD,
Qtype: dns.TypeA,
Qclass: dns.ClassINET,
}},
@@ -541,12 +555,8 @@ func checkDNSUpstreamExc(u upstream.Upstream) (err error) {
reply, err = u.Exchange(req)
if err != nil {
return fmt.Errorf("couldn't communicate with upstream: %w", err)
}
if len(reply.Answer) != 1 {
return fmt.Errorf("wrong response")
} else if a, ok := reply.Answer[0].(*dns.A); !ok || !a.A.Equal(net.IP{8, 8, 8, 8}) {
return fmt.Errorf("wrong response")
} else if len(reply.Answer) != 0 {
return errors.Error("wrong response")
}
return nil
@@ -554,14 +564,22 @@ func checkDNSUpstreamExc(u upstream.Upstream) (err error) {
// checkPrivateUpstreamExc checks if the upstream for resolving private
// addresses exchanges correctly.
//
// TODO(e.burkov): Think about testing the ip6.arpa. as well.
func checkPrivateUpstreamExc(u upstream.Upstream) (err error) {
// inAddrArpaTLD is the special-use fully-qualified domain name for PTR IP
// address resolution.
//
// See https://datatracker.ietf.org/doc/html/rfc1035#section-3.5.
const inAddrArpaTLD = "in-addr.arpa."
req := &dns.Msg{
MsgHdr: dns.MsgHdr{
Id: dns.Id(),
RecursionDesired: true,
},
Question: []dns.Question{{
Name: "1.0.0.127.in-addr.arpa.",
Name: inAddrArpaTLD,
Qtype: dns.TypePTR,
Qclass: dns.ClassINET,
}},
@@ -574,46 +592,66 @@ func checkPrivateUpstreamExc(u upstream.Upstream) (err error) {
return nil
}
func checkDNS(input string, bootstrap []string, timeout time.Duration, ef excFunc) (err error) {
if IsCommentOrEmpty(input) {
// domainSpecificTestError is a wrapper for errors returned by checkDNS to mark
// the tested upstream domain-specific and therefore consider its errors
// non-critical.
//
// TODO(a.garipov): Some common mechanism of distinguishing between errors and
// warnings (non-critical errors) is desired.
type domainSpecificTestError struct {
error
}
// checkDNS checks the upstream server defined by upstreamConfigStr using
// healthCheck for actually exchange messages. It uses bootstrap to resolve the
// upstream's address.
func checkDNS(
upstreamConfigStr string,
bootstrap []string,
timeout time.Duration,
healthCheck healthCheckFunc,
) (err error) {
if IsCommentOrEmpty(upstreamConfigStr) {
return nil
}
// Separate upstream from domains list.
var useDefault bool
if useDefault, err = validateUpstream(input); err != nil {
upstreamAddr, domains, err := separateUpstream(upstreamConfigStr)
if err != nil {
return fmt.Errorf("wrong upstream format: %w", err)
}
// No need to check this DNS server.
if !useDefault {
useDefault, err := validateUpstream(upstreamAddr, domains)
if err != nil {
return fmt.Errorf("wrong upstream format: %w", err)
} else if useDefault {
return nil
}
if input, _, err = separateUpstream(input); err != nil {
return fmt.Errorf("wrong upstream format: %w", err)
}
if len(bootstrap) == 0 {
bootstrap = defaultBootstrap
}
log.Debug("checking if upstream %s works", input)
log.Debug("dnsforward: checking if upstream %q works", upstreamAddr)
var u upstream.Upstream
u, err = upstream.AddressToUpstream(input, &upstream.Options{
u, err := upstream.AddressToUpstream(upstreamAddr, &upstream.Options{
Bootstrap: bootstrap,
Timeout: timeout,
})
if err != nil {
return fmt.Errorf("failed to choose upstream for %q: %w", input, err)
return fmt.Errorf("failed to choose upstream for %q: %w", upstreamAddr, err)
}
if err = ef(u); err != nil {
return fmt.Errorf("upstream %q fails to exchange: %w", input, err)
if err = healthCheck(u); err != nil {
err = fmt.Errorf("upstream %q fails to exchange: %w", upstreamAddr, err)
if domains != nil {
return domainSpecificTestError{error: err}
}
return err
}
log.Debug("upstream %s is ok", input)
log.Debug("dnsforward: upstream %q is ok", upstreamAddr)
return nil
}
@@ -636,6 +674,9 @@ func (s *Server) handleTestUpstreamDNS(w http.ResponseWriter, r *http.Request) {
if err != nil {
log.Info("%v", err)
result[host] = err.Error()
if _, ok := err.(domainSpecificTestError); ok {
result[host] = fmt.Sprintf("WARNING: %s", result[host])
}
continue
}
@@ -651,6 +692,9 @@ func (s *Server) handleTestUpstreamDNS(w http.ResponseWriter, r *http.Request) {
// above, we rewriting the error for it. These cases should be
// handled properly instead.
result[host] = err.Error()
if _, ok := err.(domainSpecificTestError); ok {
result[host] = fmt.Sprintf("WARNING: %s", result[host])
}
continue
}