From f58265ec98dbdcfee030cc77d89e5d02b02da389 Mon Sep 17 00:00:00 2001
From: Ainar Garipov <a.garipov@adguard.com>
Date: Mon, 15 Aug 2022 18:31:32 +0300
Subject: [PATCH] Pull request: 4836-revert-dhcp-upd

Updates #4836.

Squashed commit of the following:

commit 6fe1721d44be1c23e524d477e28b5f7cc5dd2dc6
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Mon Aug 15 17:48:41 2022 +0300

    dhcpd: reverd mod upd
---
 CHANGELOG.md                     |  2 ++
 go.mod                           |  6 +++---
 internal/dhcpd/conn_unix.go      | 16 ++++++----------
 internal/dhcpd/conn_unix_test.go |  8 +++++---
 internal/dhcpd/v4.go             |  6 ++++--
 internal/dhcpd/v4_test.go        |  6 ++++--
 6 files changed, 24 insertions(+), 20 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 00b2820d..edee3432 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -78,6 +78,7 @@ See also the [v0.107.9 GitHub milestone][ms-v0.107.9].
 
 ### Fixed
 
+- DHCP not working on most OSes ([#4836]).
 - Several UI issues ([#4775], [#4776], [#4782]).
 
 ### Removed
@@ -89,6 +90,7 @@ See also the [v0.107.9 GitHub milestone][ms-v0.107.9].
 [#4775]: https://github.com/AdguardTeam/AdGuardHome/issues/4775
 [#4776]: https://github.com/AdguardTeam/AdGuardHome/issues/4776
 [#4782]: https://github.com/AdguardTeam/AdGuardHome/issues/4782
+[#4836]: https://github.com/AdguardTeam/AdGuardHome/issues/4836
 
 [go-1.18.5]:   https://groups.google.com/g/golang-announce/c/YqYYG87xB10
 [ms-v0.107.9]: https://github.com/AdguardTeam/AdGuardHome/milestone/45?closed=1
diff --git a/go.mod b/go.mod
index 43f2847c..53e5eb1b 100644
--- a/go.mod
+++ b/go.mod
@@ -21,10 +21,9 @@ require (
 	github.com/lucas-clemente/quic-go v0.28.1
 	github.com/mdlayher/ethernet v0.0.0-20220221185849-529eae5b6118
 	github.com/mdlayher/netlink v1.6.0
-	github.com/mdlayher/packet v1.0.0
 	// TODO(a.garipov): This package is deprecated; find a new one or use
-	// our own code for that.
-	github.com/mdlayher/raw v0.1.0 // indirect
+	// our own code for that.  Perhaps, use gopacket.
+	github.com/mdlayher/raw v0.1.0
 	github.com/miekg/dns v1.1.50
 	github.com/stretchr/testify v1.7.1
 	github.com/ti-mo/netfilter v0.4.0
@@ -52,6 +51,7 @@ require (
 	github.com/marten-seemann/qtls-go1-17 v0.1.2 // indirect
 	github.com/marten-seemann/qtls-go1-18 v0.1.2 // indirect
 	github.com/marten-seemann/qtls-go1-19 v0.1.0-beta.1 // indirect
+	github.com/mdlayher/packet v1.0.0 // indirect
 	github.com/mdlayher/socket v0.2.3 // indirect
 	github.com/nxadm/tail v1.4.8 // indirect
 	github.com/onsi/ginkgo v1.16.5 // indirect
diff --git a/internal/dhcpd/conn_unix.go b/internal/dhcpd/conn_unix.go
index 837211af..1ed2105a 100644
--- a/internal/dhcpd/conn_unix.go
+++ b/internal/dhcpd/conn_unix.go
@@ -16,16 +16,18 @@ import (
 	"github.com/insomniacslk/dhcp/dhcpv4"
 	"github.com/insomniacslk/dhcp/dhcpv4/server4"
 	"github.com/mdlayher/ethernet"
-	"github.com/mdlayher/packet"
+
+	//lint:ignore SA1019 See the TODO in go.mod.
+	"github.com/mdlayher/raw"
 )
 
 // dhcpUnicastAddr is the combination of MAC and IP addresses for responding to
 // the unconfigured host.
 type dhcpUnicastAddr struct {
-	// packet.Addr is embedded here to make *dhcpUcastAddr a net.Addr without
+	// raw.Addr is embedded here to make *dhcpUcastAddr a net.Addr without
 	// actually implementing all methods.  It also contains the client's
 	// hardware address.
-	packet.Addr
+	raw.Addr
 
 	// yiaddr is an IP address just allocated by server for the host.
 	yiaddr net.IP
@@ -51,13 +53,7 @@ type dhcpConn struct {
 // newDHCPConn creates the special connection for DHCP server.
 func (s *v4Server) newDHCPConn(iface *net.Interface) (c net.PacketConn, err error) {
 	var ucast net.PacketConn
-	ucast, err = packet.Listen(
-		iface,
-		packet.Raw,
-		int(ethernet.EtherTypeIPv4),
-		nil,
-	)
-	if err != nil {
+	if ucast, err = raw.ListenPacket(iface, uint16(ethernet.EtherTypeIPv4), nil); err != nil {
 		return nil, fmt.Errorf("creating raw udp connection: %w", err)
 	}
 
diff --git a/internal/dhcpd/conn_unix_test.go b/internal/dhcpd/conn_unix_test.go
index 66899af6..84020acd 100644
--- a/internal/dhcpd/conn_unix_test.go
+++ b/internal/dhcpd/conn_unix_test.go
@@ -11,9 +11,11 @@ import (
 	"github.com/google/gopacket"
 	"github.com/google/gopacket/layers"
 	"github.com/insomniacslk/dhcp/dhcpv4"
-	"github.com/mdlayher/packet"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	//lint:ignore SA1019 See the TODO in go.mod.
+	"github.com/mdlayher/raw"
 )
 
 func TestDHCPConn_WriteTo_common(t *testing.T) {
@@ -56,7 +58,7 @@ func TestBuildEtherPkt(t *testing.T) {
 		srcIP:  net.IP{1, 2, 3, 4},
 	}
 	peer := &dhcpUnicastAddr{
-		Addr:   packet.Addr{HardwareAddr: net.HardwareAddr{6, 5, 4, 3, 2, 1}},
+		Addr:   raw.Addr{HardwareAddr: net.HardwareAddr{6, 5, 4, 3, 2, 1}},
 		yiaddr: net.IP{4, 3, 2, 1},
 	}
 	payload := (&dhcpv4.DHCPv4{}).ToBytes()
@@ -102,7 +104,7 @@ func TestBuildEtherPkt(t *testing.T) {
 	t.Run("serializing_error", func(t *testing.T) {
 		// Create a peer with invalid MAC.
 		badPeer := &dhcpUnicastAddr{
-			Addr:   packet.Addr{HardwareAddr: net.HardwareAddr{5, 4, 3, 2, 1}},
+			Addr:   raw.Addr{HardwareAddr: net.HardwareAddr{5, 4, 3, 2, 1}},
 			yiaddr: net.IP{4, 3, 2, 1},
 		}
 
diff --git a/internal/dhcpd/v4.go b/internal/dhcpd/v4.go
index 5639837f..17881d2c 100644
--- a/internal/dhcpd/v4.go
+++ b/internal/dhcpd/v4.go
@@ -20,7 +20,9 @@ import (
 	"github.com/go-ping/ping"
 	"github.com/insomniacslk/dhcp/dhcpv4"
 	"github.com/insomniacslk/dhcp/dhcpv4/server4"
-	"github.com/mdlayher/packet"
+
+	//lint:ignore SA1019 See the TODO in go.mod.
+	"github.com/mdlayher/raw"
 )
 
 // v4Server is a DHCPv4 server.
@@ -992,7 +994,7 @@ func (s *v4Server) send(peer net.Addr, conn net.PacketConn, req, resp *dhcpv4.DH
 		// Unicast DHCPOFFER and DHCPACK messages to the client's
 		// hardware address and yiaddr.
 		peer = &dhcpUnicastAddr{
-			Addr:   packet.Addr{HardwareAddr: req.ClientHWAddr},
+			Addr:   raw.Addr{HardwareAddr: req.ClientHWAddr},
 			yiaddr: resp.YourIPAddr,
 		}
 	default:
diff --git a/internal/dhcpd/v4_test.go b/internal/dhcpd/v4_test.go
index be9259d8..3c241a4a 100644
--- a/internal/dhcpd/v4_test.go
+++ b/internal/dhcpd/v4_test.go
@@ -12,9 +12,11 @@ import (
 	"github.com/AdguardTeam/golibs/stringutil"
 	"github.com/AdguardTeam/golibs/testutil"
 	"github.com/insomniacslk/dhcp/dhcpv4"
-	"github.com/mdlayher/packet"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	//lint:ignore SA1019 See the TODO in go.mod.
+	"github.com/mdlayher/raw"
 )
 
 var (
@@ -554,7 +556,7 @@ func TestV4Server_Send(t *testing.T) {
 		req:  &dhcpv4.DHCPv4{ClientHWAddr: knownMAC},
 		resp: &dhcpv4.DHCPv4{YourIPAddr: knownIP},
 		want: &dhcpUnicastAddr{
-			Addr:   packet.Addr{HardwareAddr: knownMAC},
+			Addr:   raw.Addr{HardwareAddr: knownMAC},
 			yiaddr: knownIP,
 		},
 	}, {