Pull request 50: 6050-use-netip

Merge in GO/urlfilter from 6050-use-netip to master

Updates AdguardTeam/AdGuardHome#6050.

Squashed commit of the following:

commit de1cd57
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Mon Aug 21 20:13:21 2023 +0300

    all: imp docs, upd tools

commit 3d19556
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Fri Aug 18 20:30:15 2023 +0300

    all: fix go.mod

commit 852bc06
Merge: 6b3749e b1001a1
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Fri Aug 18 18:50:23 2023 +0300

    Merge branch 'master' into 6050-use-netip

commit 6b3749e
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Aug 17 17:19:43 2023 +0300

    all: upd slices again

commit 7a914a9
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Tue Aug 8 17:33:14 2023 +0300

    rules: imp docs

commit 561b59e
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Tue Aug 8 14:38:36 2023 +0300

    all: imp docs, tests

commit fa24781
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Tue Aug 8 12:11:09 2023 +0300

    rules: revert changes, imp docs

commit d0b36ae
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Mon Aug 7 19:25:49 2023 +0300

    all: migrate to go1.20 and netip

cmd/main.go

@@ -7,6 +7,7 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"net"
+	"net/netip"
 	"os"
 	"os/signal"
 	"syscall"
@@ -15,7 +16,6 @@ import (
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/gomitmproxy"
 	"github.com/AdguardTeam/gomitmproxy/mitm"
-	"github.com/AdguardTeam/urlfilter/filterutil"
 	"github.com/AdguardTeam/urlfilter/proxy"
 	goFlags "github.com/jessevdk/go-flags"
 )
@@ -108,9 +108,9 @@ func run(options Options) {
 }
 
 func createServerConfig(options Options) proxy.Config {
-	listenIP := filterutil.ParseIP(options.ListenAddr)
-	if listenIP == nil {
-		log.Fatalf("cannot parse %s", options.ListenAddr)
+	listenIP, err := netip.ParseAddr(options.ListenAddr)
+	if err != nil {
+		log.Fatalf("parsing listen addr: %s", err)
 	}
 
 	mitmConfig := createMITMConfig(options)
@@ -121,7 +121,8 @@ func createServerConfig(options Options) proxy.Config {
 			log.Fatalf("HTTPS hostname must be specified")
 		}
 
-		proxyCert, err := mitmConfig.GetOrCreateCert(options.HTTPSHostname)
+		var proxyCert *tls.Certificate
+		proxyCert, err = mitmConfig.GetOrCreateCert(options.HTTPSHostname)
 		if err != nil {
 			log.Fatalf("failed to generate HTTPS proxy certificate for %s: %v", options.HTTPSHostname, err)
 		}
@@ -141,7 +142,8 @@ func createServerConfig(options Options) proxy.Config {
 		config.FiltersPaths[i] = v
 	}
 
-	addr := &net.TCPAddr{IP: listenIP, Port: options.ListenPort}
+	// TODO(e.burkov):  Use netip.AddrPort when gomitmproxy will support it.
+	addr := &net.TCPAddr{IP: listenIP.AsSlice(), Port: options.ListenPort}
 	config.ProxyConfig = gomitmproxy.Config{
 		ListenAddr: addr,
 		TLSConfig:  tlsConfig,

dnsengine.go

@@ -1,6 +1,8 @@
 package urlfilter
 
 import (
+	"net/netip"
+
 	"github.com/AdguardTeam/urlfilter/filterlist"
 	"github.com/AdguardTeam/urlfilter/filterutil"
 	"github.com/AdguardTeam/urlfilter/rules"
@@ -32,9 +34,10 @@ type DNSResult struct {
 	// rules.
 	NetworkRule *rules.NetworkRule
 
-	// HostRulesV4 and HostRulesV6 are the host rules with IPv4 and IPv6
-	// addresses respectively.
+	// HostRulesV4 are the host rules with IPv4 addresses.
 	HostRulesV4 []*rules.HostRule
+
+	// HostRulesV6 are the host rules with IPv6 addresses.
 	HostRulesV6 []*rules.HostRule
 
 	// NetworkRules are all matched network rules.  These include unprocessed
@@ -44,22 +47,26 @@ type DNSResult struct {
 
 // DNSRequest represents a DNS query with associated metadata.
 type DNSRequest struct {
-	// Hostname is a hostname (or IP address).
-	Hostname string
-	// ClientIP is the address of client.
-	ClientIP string
-	// ClientName is the name of client.
+	// ClientIP is the IP address to match against $client modifiers.  The
+	// default zero value won't be considered.
+	ClientIP netip.Addr
+
+	// ClientName is the name to match against $client modifiers.  The default
+	// empty value won't be considered.
 	ClientName string
 
-	// SortedClientTags is the sorted list of client tags ($ctag).
+	// Hostname is the hostname to filter.
+	Hostname string
+
+	// SortedClientTags is the list of tags to match against $ctag modifiers.
 	SortedClientTags []string
 
 	// DNSType is the type of the resource record (RR) of a DNS request, for
-	// example "A" or "AAAA".  See package github.com/miekg/dns for all
-	// acceptable constants.
+	// example "A" or "AAAA".  See [rules.RRValue] for all acceptable constants
+	// and their corresponding values.
 	DNSType rules.RRType
 
-	// Answer is true if this hostname or IP is from a DNS response.
+	// Answer if the filtering request is for filtering a DNS response.
 	Answer bool
 }
 
@@ -116,7 +123,7 @@ func NewDNSEngine(s *filterlist.RuleStorage) *DNSEngine {
 //	192.168.0.1 example.local
 //	2000::1 example.local
 func (d *DNSEngine) Match(hostname string) (res *DNSResult, matched bool) {
-	return d.MatchRequest(&DNSRequest{Hostname: hostname, ClientIP: "0.0.0.0"})
+	return d.MatchRequest(&DNSRequest{Hostname: hostname})
 }
 
 // MatchRequest matches the specified DNS request.  The return parameter matched
@@ -164,7 +171,7 @@ func (d *DNSEngine) MatchRequest(dReq *DNSRequest) (res *DNSResult, matched bool
 			continue
 		}
 
-		if hostRule.IP.To4() != nil {
+		if hostRule.IP.Is4() {
 			res.HostRulesV4 = append(res.HostRulesV4, hostRule)
 		} else {
 			res.HostRulesV6 = append(res.HostRulesV6, hostRule)