Add plugin ACL for source ip filtering (#3103)

* Add plugin ACL for source ip filtering

Signed-off-by: An Xiao <hac@zju.edu.cn>

* Allow all arguments to be optional and support multiple qtypes in a single policy

Signed-off-by: An Xiao <hac@zju.edu.cn>

* Add newline before third party imports

Signed-off-by: An Xiao <hac@zju.edu.cn>

* Use camel instead of underscore in method name

Signed-off-by: An Xiao <hac@zju.edu.cn>

* Start with an upper case letter in t.Errorf()

Signed-off-by: An Xiao <hac@zju.edu.cn>

* Use the qtype parse logic in miekg/dns

Signed-off-by: An Xiao <hac@zju.edu.cn>

* Use third party trie implementation as the ip filter

Signed-off-by: An Xiao <hac@zju.edu.cn>

* Update based on rdrozhdzh's comment

Signed-off-by: An Xiao <hac@zju.edu.cn>

* Change the type of action to int

Signed-off-by: An Xiao <hac@zju.edu.cn>

* Add IPv6 support

Signed-off-by: An Xiao <hac@zju.edu.cn>

* Update plugin.cfg

Signed-off-by: An Xiao <hac@zju.edu.cn>

* Remove file functionality

Signed-off-by: An Xiao <hac@zju.edu.cn>

* Update

Signed-off-by: Xiao An <hac@zju.edu.cn>

* Update README

Signed-off-by: Xiao An <hac@zju.edu.cn>

* remove comments

Signed-off-by: Xiao An <hac@zju.edu.cn>

* update

Signed-off-by: Xiao An <hac@zju.edu.cn>

* Update dependency

Signed-off-by: Xiao An <hac@zju.edu.cn>

* Update

Signed-off-by: Xiao An <hac@zju.edu.cn>

* Update test

Signed-off-by: Xiao An <hac@zju.edu.cn>

* Add OWNERS

Signed-off-by: Xiao An <hac@zju.edu.cn>

* Refactor shouldBlock and skip useless check

Signed-off-by: Xiao An <hac@zju.edu.cn>

* Introduce ActionNone

Signed-off-by: Xiao An <hac@zju.edu.cn>

* Update label name

Signed-off-by: Xiao An <hac@zju.edu.cn>

* Avoid capitalizing private types

Signed-off-by: Xiao An <hac@zju.edu.cn>

1 files changed, 396 insertions, 0 deletions

diff --git a/plugin/acl/acl_test.go b/plugin/acl/acl_test.go
new file mode 100644
index 000000000..9b23edc53
--- /dev/null
+++ b/plugin/acl/acl_test.go
@@ -0,0 +1,396 @@
+package acl
+
+import (
+	"context"
+	"testing"
+
+	"github.com/coredns/coredns/plugin/test"
+
+	"github.com/caddyserver/caddy"
+	"github.com/miekg/dns"
+)
+
+type testResponseWriter struct {
+	test.ResponseWriter
+	Rcode int
+}
+
+func (t *testResponseWriter) setRemoteIP(ip string) {
+	t.RemoteIP = ip
+}
+
+// WriteMsg implement dns.ResponseWriter interface.
+func (t *testResponseWriter) WriteMsg(m *dns.Msg) error {
+	t.Rcode = m.Rcode
+	return nil
+}
+
+func NewTestControllerWithZones(input string, zones []string) *caddy.Controller {
+	ctr := caddy.NewTestController("dns", input)
+	for _, zone := range zones {
+		ctr.ServerBlockKeys = append(ctr.ServerBlockKeys, zone)
+	}
+	return ctr
+}
+
+func TestACLServeDNS(t *testing.T) {
+	type args struct {
+		domain   string
+		sourceIP string
+		qtype    uint16
+	}
+	tests := []struct {
+		name      string
+		config    string
+		zones     []string
+		args      args
+		wantRcode int
+		wantErr   bool
+	}{
+		// IPv4 tests.
+		{
+			"Blacklist 1 BLOCKED",
+			`acl example.org {
+				block type A net 192.168.0.0/16
+			}`,
+			[]string{},
+			args{
+				"www.example.org.",
+				"192.168.0.2",
+				dns.TypeA,
+			},
+			dns.RcodeRefused,
+			false,
+		},
+		{
+			"Blacklist 1 ALLOWED",
+			`acl example.org {
+				block type A net 192.168.0.0/16
+			}`,
+			[]string{},
+			args{
+				"www.example.org.",
+				"192.167.0.2",
+				dns.TypeA,
+			},
+			dns.RcodeSuccess,
+			false,
+		},
+		{
+			"Blacklist 2 BLOCKED",
+			`
+			acl example.org {
+				block type * net 192.168.0.0/16
+			}`,
+			[]string{},
+			args{
+				"www.example.org.",
+				"192.168.0.2",
+				dns.TypeAAAA,
+			},
+			dns.RcodeRefused,
+			false,
+		},
+		{
+			"Blacklist 3 BLOCKED",
+			`acl example.org {
+				block type A
+			}`,
+			[]string{},
+			args{
+				"www.example.org.",
+				"10.1.0.2",
+				dns.TypeA,
+			},
+			dns.RcodeRefused,
+			false,
+		},
+		{
+			"Blacklist 3 ALLOWED",
+			`acl example.org {
+				block type A
+			}`,
+			[]string{},
+			args{
+				"www.example.org.",
+				"10.1.0.2",
+				dns.TypeAAAA,
+			},
+			dns.RcodeSuccess,
+			false,
+		},
+		{
+			"Blacklist 4 Single IP BLOCKED",
+			`acl example.org {
+				block type A net 192.168.1.2
+			}`,
+			[]string{},
+			args{
+				"www.example.org.",
+				"192.168.1.2",
+				dns.TypeA,
+			},
+			dns.RcodeRefused,
+			false,
+		},
+		{
+			"Blacklist 4 Single IP ALLOWED",
+			`acl example.org {
+				block type A net 192.168.1.2
+			}`,
+			[]string{},
+			args{
+				"www.example.org.",
+				"192.168.1.3",
+				dns.TypeA,
+			},
+			dns.RcodeSuccess,
+			false,
+		},
+		{
+			"Whitelist 1 ALLOWED",
+			`acl example.org {
+				allow net 192.168.0.0/16
+				block
+			}`,
+			[]string{},
+			args{
+				"www.example.org.",
+				"192.168.0.2",
+				dns.TypeA,
+			},
+			dns.RcodeSuccess,
+			false,
+		},
+		{
+			"Whitelist 1 REFUSED",
+			`acl example.org {
+				allow type * net 192.168.0.0/16
+				block
+			}`,
+			[]string{},
+			args{
+				"www.example.org.",
+				"10.1.0.2",
+				dns.TypeA,
+			},
+			dns.RcodeRefused,
+			false,
+		},
+		{
+			"Fine-Grained 1 REFUSED",
+			`acl a.example.org {
+				block type * net 192.168.1.0/24
+			}`,
+			[]string{"example.org"},
+			args{
+				"a.example.org.",
+				"192.168.1.2",
+				dns.TypeA,
+			},
+			dns.RcodeRefused,
+			false,
+		},
+		{
+			"Fine-Grained 1 ALLOWED",
+			`acl a.example.org {
+				block net 192.168.1.0/24
+			}`,
+			[]string{"example.org"},
+			args{
+				"www.example.org.",
+				"192.168.1.2",
+				dns.TypeA,
+			},
+			dns.RcodeSuccess,
+			false,
+		},
+		{
+			"Fine-Grained 2 REFUSED",
+			`acl {
+				block net 192.168.1.0/24
+			}`,
+			[]string{"example.org"},
+			args{
+				"a.example.org.",
+				"192.168.1.2",
+				dns.TypeA,
+			},
+			dns.RcodeRefused,
+			false,
+		},
+		{
+			"Fine-Grained 2 ALLOWED",
+			`acl {
+				block net 192.168.1.0/24
+			}`,
+			[]string{"example.org"},
+			args{
+				"a.example.com.",
+				"192.168.1.2",
+				dns.TypeA,
+			},
+			dns.RcodeSuccess,
+			false,
+		},
+		{
+			"Fine-Grained 3 REFUSED",
+			`acl a.example.org {
+				block net 192.168.1.0/24
+			}
+			acl b.example.org {
+				block type * net 192.168.2.0/24
+			}`,
+			[]string{"example.org"},
+			args{
+				"b.example.org.",
+				"192.168.2.2",
+				dns.TypeA,
+			},
+			dns.RcodeRefused,
+			false,
+		},
+		{
+			"Fine-Grained 3 ALLOWED",
+			`acl a.example.org {
+				block net 192.168.1.0/24
+			}
+			acl b.example.org {
+				block net 192.168.2.0/24
+			}`,
+			[]string{"example.org"},
+			args{
+				"b.example.org.",
+				"192.168.1.2",
+				dns.TypeA,
+			},
+			dns.RcodeSuccess,
+			false,
+		},
+		// IPv6 tests.
+		{
+			"Blacklist 1 BLOCKED IPv6",
+			`acl example.org {
+				block type A net 2001:db8:abcd:0012::0/64
+			}`,
+			[]string{},
+			args{
+				"www.example.org.",
+				"2001:db8:abcd:0012::1230",
+				dns.TypeA,
+			},
+			dns.RcodeRefused,
+			false,
+		},
+		{
+			"Blacklist 1 ALLOWED IPv6",
+			`acl example.org {
+				block type A net 2001:db8:abcd:0012::0/64
+			}`,
+			[]string{},
+			args{
+				"www.example.org.",
+				"2001:db8:abcd:0013::0",
+				dns.TypeA,
+			},
+			dns.RcodeSuccess,
+			false,
+		},
+		{
+			"Blacklist 2 BLOCKED IPv6",
+			`acl example.org {
+				block type A
+			}`,
+			[]string{},
+			args{
+				"www.example.org.",
+				"2001:0db8:85a3:0000:0000:8a2e:0370:7334",
+				dns.TypeA,
+			},
+			dns.RcodeRefused,
+			false,
+		},
+		{
+			"Blacklist 3 Single IP BLOCKED IPv6",
+			`acl example.org {
+				block type A net 2001:0db8:85a3:0000:0000:8a2e:0370:7334
+			}`,
+			[]string{},
+			args{
+				"www.example.org.",
+				"2001:0db8:85a3:0000:0000:8a2e:0370:7334",
+				dns.TypeA,
+			},
+			dns.RcodeRefused,
+			false,
+		},
+		{
+			"Blacklist 3 Single IP ALLOWED IPv6",
+			`acl example.org {
+				block type A net 2001:0db8:85a3:0000:0000:8a2e:0370:7334
+			}`,
+			[]string{},
+			args{
+				"www.example.org.",
+				"2001:0db8:85a3:0000:0000:8a2e:0370:7335",
+				dns.TypeA,
+			},
+			dns.RcodeSuccess,
+			false,
+		},
+		{
+			"Fine-Grained 1 REFUSED IPv6",
+			`acl a.example.org {
+				block type * net 2001:db8:abcd:0012::0/64
+			}`,
+			[]string{"example.org"},
+			args{
+				"a.example.org.",
+				"2001:db8:abcd:0012:2019::0",
+				dns.TypeA,
+			},
+			dns.RcodeRefused,
+			false,
+		},
+		{
+			"Fine-Grained 1 ALLOWED IPv6",
+			`acl a.example.org {
+				block net 2001:db8:abcd:0012::0/64
+			}`,
+			[]string{"example.org"},
+			args{
+				"www.example.org.",
+				"2001:db8:abcd:0012:2019::0",
+				dns.TypeA,
+			},
+			dns.RcodeSuccess,
+			false,
+		},
+	}
+
+	ctx := context.Background()
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ctr := NewTestControllerWithZones(tt.config, tt.zones)
+			a, err := parse(ctr)
+			a.Next = test.NextHandler(dns.RcodeSuccess, nil)
+			if err != nil {
+				t.Errorf("Error: Cannot parse acl from config: %v", err)
+				return
+			}
+
+			w := &testResponseWriter{}
+			m := new(dns.Msg)
+			w.setRemoteIP(tt.args.sourceIP)
+			m.SetQuestion(tt.args.domain, tt.args.qtype)
+			_, err = a.ServeDNS(ctx, w, m)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("Error: acl.ServeDNS() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if w.Rcode != tt.wantRcode {
+				t.Errorf("Error: acl.ServeDNS() Rcode = %v, want %v", w.Rcode, tt.wantRcode)
+			}
+		})
+	}
+}