Merge: + DNS Rewrites: support wildcard domain name

Closes #922

* commit '5ba45b91c9cfde84fc0866e6b3fca679504975e7':
  * client: fix render field for DNS settings
  + client: handle wildcard domains
  + DNS Rewrites: support wildcard domain name

AGHTechDoc.md

@@ -916,6 +916,8 @@ Response:
 	...
 	]
 
+`domain` can be an exact host name (`www.host.com`) or a wildcard (`*.host.com`).
+
 
 ### API: Add a rewrite entry
 

client/src/__locales/en.json

@@ -302,7 +302,7 @@
     "setup_guide": "Setup guide",
     "dns_addresses": "DNS addresses",
     "dns_start": "DNS server is starting up",
-    "dns_status_error": "Error of getting DNS server status",
+    "dns_status_error": "Error checking the DNS server status",
     "down": "Down",
     "fix": "Fix",
     "dns_providers": "Here is a <0>list of known DNS providers</0> to choose from.",
@@ -372,7 +372,7 @@
     "rewrite_desc": "Allows to easily configure custom DNS response for a specific domain name.",
     "rewrite_applied": "Applied Rewrite rule",
     "dns_rewrites": "DNS rewrites",
-    "form_domain": "Enter domain",
+    "form_domain": "Enter domain name or wildcard",
     "form_answer": "Enter IP address or domain name",
     "form_error_domain_format": "Invalid domain format",
     "form_error_answer_format": "Invalid answer format",
@@ -428,5 +428,8 @@
     "whois": "Whois",
     "filtering_rules_learn_more": "<0>Learn more</0> about creating your own hosts blocklists.",
     "blocked_by_response": "Blocked by CNAME or IP in response",
-    "try_again": "Try again"
+    "try_again": "Try again",
+    "domain_desc": "Enter the domain name or wildcard you want to be rewritten.",
+    "example_rewrite_domain": "rewrite responses for this domain name only.",
+    "example_rewrite_wildcard": "rewrite responses for all <0>example.org</0> subdomains."
 }

client/src/components/Settings/Dns/Config/Form.js

@@ -6,7 +6,7 @@ import { Trans, withNamespaces } from 'react-i18next';
 import flow from 'lodash/flow';
 
 import {
-    renderField,
+    renderInputField,
     renderRadioField,
     renderSelectField,
     required,
@@ -45,7 +45,7 @@ let Form = ({
                     <Field
                         name="ratelimit"
                         type="number"
-                        component={renderField}
+                        component={renderInputField}
                         className="form-control"
                         placeholder={t('form_enter_rate_limit')}
                         normalize={toNumber}
@@ -90,7 +90,7 @@ let Form = ({
                             </div>
                             <Field
                                 name="blocking_ipv4"
-                                component={renderField}
+                                component={renderInputField}
                                 className="form-control"
                                 placeholder={t('form_enter_ip')}
                                 validate={[ipv4, required]}
@@ -107,7 +107,7 @@ let Form = ({
                             </div>
                             <Field
                                 name="blocking_ipv6"
-                                component={renderField}
+                                component={renderInputField}
                                 className="form-control"
                                 placeholder={t('form_enter_ip')}
                                 validate={[ipv6, required]}

client/src/components/Settings/Dns/Rewrites/Form.js

@@ -20,6 +20,9 @@ const Form = (props) => {
     return (
         <form onSubmit={handleSubmit}>
             <div className="modal-body">
+                <div className="form__desc form__desc--top">
+                    <Trans>domain_desc</Trans>
+                </div>
                 <div className="form__group">
                     <Field
                         id="domain"
@@ -31,6 +34,22 @@ const Form = (props) => {
                         validate={[required, domain]}
                     />
                 </div>
+
+                <Trans>examples_title</Trans>:
+                <ol className="leading-loose">
+                    <li>
+                        <code>example.org</code> – <Trans>example_rewrite_domain</Trans>
+                    </li>
+                    <li>
+                        <code>*.example.org</code> –&nbsp;
+                        <span>
+                            <Trans components={[<code key="0">text</code>]}>
+                                example_rewrite_wildcard
+                            </Trans>
+                        </span>
+                    </li>
+                </ol>
+
                 <div className="form__group">
                     <Field
                         id="answer"

client/src/helpers/constants.js

@@ -1,5 +1,5 @@
 export const R_URL_REQUIRES_PROTOCOL = /^https?:\/\/[^/\s]+(\/.*)?$/;
-export const R_HOST = /^(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\\-]*[a-zA-Z0-9])\.)*([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\\-]*[A-Za-z0-9])$/;
+export const R_HOST = /^(\*\.)?([\w-]+\.)+[\w-]+$/;
 export const R_IPV4 = /^(?:(?:^|\.)(?:2(?:5[0-5]|[0-4]\d)|1?\d?\d)){4}$/;
 export const R_IPV6 = /^(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|::(ffff(:0{1,4}){0,1}:){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))$/;
 export const R_CIDR = /^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])(\/([0-9]|[1-2][0-9]|3[0-2]))$/;

dnsfilter/dnsfilter.go

@@ -334,6 +334,13 @@ func (d *Dnsfilter) CheckHost(host string, qtype uint16, setts *RequestFiltering
 	return Result{}, nil
 }
 
+// Return TRUE of host name matches a wildcard pattern
+func matchDomainWildcard(host, wildcard string) bool {
+	return len(wildcard) >= 2 &&
+		wildcard[0] == '*' && wildcard[1] == '.' &&
+		strings.HasSuffix(host, wildcard[1:])
+}
+
 // Process rewrites table
 // . Find CNAME for a domain name
 //  . if found, set domain name to canonical name
@@ -347,8 +354,10 @@ func (d *Dnsfilter) processRewrites(host string, qtype uint16) Result {
 
 	for _, r := range d.Rewrites {
 		if r.Domain != host {
+			if !matchDomainWildcard(host, r.Domain) {
 				continue
 			}
+		}
 
 		ip := net.ParseIP(r.Answer)
 		if ip == nil {
@@ -362,8 +371,10 @@ func (d *Dnsfilter) processRewrites(host string, qtype uint16) Result {
 
 	for _, r := range d.Rewrites {
 		if r.Domain != host {
+			if !matchDomainWildcard(host, r.Domain) {
 				continue
 			}
+		}
 
 		ip := net.ParseIP(r.Answer)
 		if ip == nil {

dnsfilter/dnsfilter_test.go

@@ -474,6 +474,60 @@ func TestClientSettings(t *testing.T) {
 	assert.True(t, r.IsFiltered && r.Reason == FilteredBlockedService)
 }
 
+func TestRewrites(t *testing.T) {
+	d := Dnsfilter{}
+	// CNAME, A, AAAA
+	d.Rewrites = []RewriteEntry{
+		RewriteEntry{"somecname", "somehost.com"},
+		RewriteEntry{"somehost.com", "0.0.0.0"},
+
+		RewriteEntry{"host.com", "1.2.3.4"},
+		RewriteEntry{"host.com", "1.2.3.5"},
+		RewriteEntry{"host.com", "1:2:3::4"},
+		RewriteEntry{"www.host.com", "host.com"},
+	}
+	r := d.processRewrites("host2.com", dns.TypeA)
+	assert.Equal(t, NotFilteredNotFound, r.Reason)
+
+	r = d.processRewrites("www.host.com", dns.TypeA)
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.Equal(t, "host.com", r.CanonName)
+	assert.True(t, len(r.IPList) == 2)
+	assert.True(t, r.IPList[0].Equal(net.ParseIP("1.2.3.4")))
+	assert.True(t, r.IPList[1].Equal(net.ParseIP("1.2.3.5")))
+
+	r = d.processRewrites("www.host.com", dns.TypeAAAA)
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.True(t, len(r.IPList) == 1)
+	assert.True(t, r.IPList[0].Equal(net.ParseIP("1:2:3::4")))
+
+	// wildcard
+	d.Rewrites = []RewriteEntry{
+		RewriteEntry{"*.host.com", "1.2.3.5"},
+		RewriteEntry{"host.com", "1.2.3.4"},
+	}
+	r = d.processRewrites("host.com", dns.TypeA)
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.True(t, r.IPList[0].Equal(net.ParseIP("1.2.3.4")))
+
+	r = d.processRewrites("www.host.com", dns.TypeA)
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.True(t, r.IPList[0].Equal(net.ParseIP("1.2.3.5")))
+
+	r = d.processRewrites("www.host2.com", dns.TypeA)
+	assert.Equal(t, NotFilteredNotFound, r.Reason)
+
+	// wildcard + CNAME
+	d.Rewrites = []RewriteEntry{
+		RewriteEntry{"*.host.com", "host.com"},
+		RewriteEntry{"host.com", "1.2.3.4"},
+	}
+	r = d.processRewrites("www.host.com", dns.TypeA)
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.Equal(t, "host.com", r.CanonName)
+	assert.True(t, r.IPList[0].Equal(net.ParseIP("1.2.3.4")))
+}
+
 // BENCHMARKS
 
 func BenchmarkSafeBrowsing(b *testing.B) {