Pull request: 3289 freebsd dhcp

Merge in DNS/adguard-home from 3289-freebsd-dhcp to master

Updates #3289.

Squashed commit of the following:

commit 1365d8f17293da611b860525d519a7bbd7851902
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Fri Jul 30 15:01:13 2021 +0300

    dhcpd: fix doc

commit 26724df27e92d457c39c8bf0fb78179a874e3fb2
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Fri Jul 30 14:52:58 2021 +0300

    all: imp code & docs

commit 9a9574a885d3d2129ef54fefb9a56857ce060cff
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Thu Jul 29 15:51:07 2021 +0300

    all: fix broadcasting, sup freebsd dhcp, fix http response

internal/aghnet/net_freebsd_test.go

@@ -0,0 +1,60 @@
+//go:build freebsd
+// +build freebsd
+
+package aghnet
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestRcConfStaticConfig(t *testing.T) {
+	const ifaceName = `em0`
+	const nl = "\n"
+
+	testCases := []struct {
+		name       string
+		rcconfData string
+		wantHas    bool
+	}{{
+		name:       "simple",
+		rcconfData: `ifconfig_em0="inet 127.0.0.253 netmask 0xffffffff"` + nl,
+		wantHas:    true,
+	}, {
+		name:       "case_insensitiveness",
+		rcconfData: `ifconfig_em0="InEt 127.0.0.253 NeTmAsK 0xffffffff"` + nl,
+		wantHas:    true,
+	}, {
+		name: "comments_and_trash",
+		rcconfData: `# comment 1` + nl +
+			`` + nl +
+			`# comment 2` + nl +
+			`ifconfig_em0="inet 127.0.0.253 netmask 0xffffffff"` + nl,
+		wantHas: true,
+	}, {
+		name: "aliases",
+		rcconfData: `ifconfig_em0_alias="inet 127.0.0.1/24"` + nl +
+			`ifconfig_em0="inet 127.0.0.253 netmask 0xffffffff"` + nl,
+		wantHas: true,
+	}, {
+		name: "incorrect_config",
+		rcconfData: `ifconfig_em0="inet6 127.0.0.253 netmask 0xffffffff"` + nl +
+			`ifconfig_em0="inet 127.0.0.253 net-mask 0xffffffff"` + nl +
+			`ifconfig_em0="inet 256.256.256.256 netmask 0xffffffff"` + nl +
+			`ifconfig_em0=""` + nl,
+		wantHas: false,
+	}}
+
+	for _, tc := range testCases {
+		r := strings.NewReader(tc.rcconfData)
+		t.Run(tc.name, func(t *testing.T) {
+			has, err := rcConfStaticConfig(r, ifaceName)
+			require.NoError(t, err)
+
+			assert.Equal(t, tc.wantHas, has)
+		})
+	}
+}