Rewrite edns0 (#561)

* Add edns0 code rewrite

* check arg count

* change `new`; set EDNS0 if request doesn't have it set

* change set to replace_or_append

* change to append_or_replace

* return error in new

* update documents

* fixt UT

* return error

* go fmt

* Rework for more general EDNS0 use

Also changed how rules are created and validated. Implements
EDNS0 NSID in addition to local.

* go fmt

* README updates, NSID tests and fixes

* gofmt -s -w

* Fix tests for rewrite syntax change

* Add tests, fix error message

* Review nits

* Missed on nit

* More tests, integration test, fix edns0 parse issue

* Fix README, use RewriteIgnored

* go fmt

13 files changed, 559 insertions, 257 deletions

diff --git a/middleware/rewrite/README.md b/middleware/rewrite/README.md
index ed5aa58e1..3d0c6c321 100644
--- a/middleware/rewrite/README.md
+++ b/middleware/rewrite/README.md
@@ -23,79 +23,37 @@ rewritten; e.g., to rewrite CH queries to IN use `rewrite class CH IN`.
 When the FIELD is `name` the query name in the message is rewritten; this
 needs to be a full match of the name, e.g., `rewrite name miek.nl example.org`.
 
+When the FIELD is `edns0` an EDNS0 option can be appended to the request as described below.
+
 If you specify multiple rules and an incoming query matches on multiple (simple) rules, only
 the first rewrite is applied.
 
+## EDNS0 Options
 
-> Everything below this line has not been implemented, yet.
-
-~~~
-rewrite [basename] {
-    regexp pattern
-    ext    extensions...
-    if     a cond b
-    status code
-    to     destinations...
-}
-~~~
+Using FIELD edns0, you can set, append, or replace specific EDNS0 options on the request.
 
-* basepath is the base path to match before rewriting with a regular expression. Default is /.
-* regexp (shorthand: r) will match the path with the given regular expression pattern. Extremely high-load servers should avoid using regular expressions.
-* extensions... is a space-separated list of file extensions to include or ignore. Prefix an extension with ! to exclude an extension. The forward slash / symbol matches paths without file extensions.
-* if specifies a rewrite condition. Multiple ifs are AND-ed together. a and b are any string and may use request placeholders. cond is the condition, with possible values explained below.
-* status will respond with the given status code instead of performing a rewrite. In other words, use either "status" or "to" in your rule, but not both. The code must be a number in the format 2xx or 4xx.
-* destinations... is one or more space-separated paths to rewrite to, with support for request placeholders as well as numbered regular expression captures such as {1}, {2}, etc. Rewrite will check each destination in order and rewrite to the first destination that exists. Each one is checked as a file or, if it ends with /, as a directory. The last destination will act as the default if no other destination exists.
-"if" Conditions
+* `replace` will modify any matching (what that means may vary based on EDNS0 type) option with the specified option
+* `append` will add the option regardless of what options already exist
+* `set` will modify a matching option or add one if none is found
 
-The if keyword is a powerful way to describe your rule. It takes the format a cond b, where the values a and b are separated by cond, a condition. The condition can be any of these:
-
-~~~
-is = a equals b
-not = a does NOT equal b
-has = a has b as a substring (b is a substring of a)
-not_has = b is NOT a substring of a
-starts_with = b is a prefix of a
-ends_with = b is a suffix of a
-match = a matches b, where b is a regular expression
-not_match = a does NOT match b, where b is a regular expression
-~~~
+Currently supported are `EDNS0_LOCAL` and `EDNS0_NSID`.
 
-## Examples
+### `EDNS0_LOCAL`
 
-When requests come in for /mobile, actually serve /mobile/index.
-rewrite /mobile /mobile/index
-If the file is not favicon.ico and it is not a valid file or directory, serve the maintenance page if present, or finally, rewrite to index.php.
+This has two fields, code and data. A match is defined as having the same code. Data may be a string, or if
+it starts with `0x` it will be treated as hex. Example:
 
 ~~~
-rewrite {
-    if {file} not favicon.ico
-    to {path} {path}/ /maintenance.html /index.php
-}
+rewrite edns0 local set 0xffee 0x61626364
 ~~~
 
-If user agent includes "mobile" and path is not a valid file/directory, rewrite to the mobile index page.
+rewrites the first local option with code 0xffee, setting the data to "abcd". Equivalent:
 
 ~~~
-rewrite {
-    if if {>User-agent} has mobile
-    to {path} {path}/ /mobile/index.php
-}
+rewrite edns0 local set 0xffee abcd
 ~~~
 
-If the request path starts with /source, respond with HTTP 403 Forbidden.
+### `EDNS0_NSID`
 
-~~~
-rewrite {
-    regexp ^/source
-    status 403
-}
-~~~
-
-Rewrite /app to /index with a query string. {1} is the matched group (.*).
-
-~~~
-rewrite /app {
-    r  (.*)
-    to /index?path={1}
-}
-~~~
+This has no fields; it will add an NSID option with an empty string for the NSID. If the option already exists
+and the action is `replace` or `set`, then the NSID in the option will be set to the empty string.
diff --git a/middleware/rewrite/class.go b/middleware/rewrite/class.go
index ba383df81..a2bd00d0f 100644
--- a/middleware/rewrite/class.go
+++ b/middleware/rewrite/class.go
@@ -1,26 +1,30 @@
-// Package rewrite is middleware for rewriting requests internally to something different.
 package rewrite
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/miekg/dns"
 )
 
-// ClassRule is a class rewrite rule.
-type ClassRule struct {
+type classRule struct {
 	fromClass, toClass uint16
 }
 
-// New initializes rule.
-func (rule ClassRule) New(args ...string) Rule {
-	from, to := args[0], strings.Join(args[1:], " ")
-	return &ClassRule{dns.StringToClass[from], dns.StringToClass[to]}
-
+func newClassRule(fromS, toS string) (Rule, error) {
+	var from, to uint16
+	var ok bool
+	if from, ok = dns.StringToClass[strings.ToUpper(fromS)]; !ok {
+		return nil, fmt.Errorf("invalid class %q", strings.ToUpper(fromS))
+	}
+	if to, ok = dns.StringToClass[strings.ToUpper(toS)]; !ok {
+		return nil, fmt.Errorf("invalid class %q", strings.ToUpper(toS))
+	}
+	return &classRule{fromClass: from, toClass: to}, nil
 }
 
 // Rewrite rewrites the the current request.
-func (rule ClassRule) Rewrite(r *dns.Msg) Result {
+func (rule *classRule) Rewrite(r *dns.Msg) Result {
 	if rule.fromClass > 0 && rule.toClass > 0 {
 		if r.Question[0].Qclass == rule.fromClass {
 			r.Question[0].Qclass = rule.toClass
diff --git a/middleware/rewrite/edns0.go b/middleware/rewrite/edns0.go
new file mode 100644
index 000000000..3ba214c6a
--- /dev/null
+++ b/middleware/rewrite/edns0.go
@@ -0,0 +1,141 @@
+// Package rewrite is middleware for rewriting requests internally to something different.
+package rewrite
+
+import (
+	"encoding/hex"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/miekg/dns"
+)
+
+// edns0LocalRule is a rewrite rule for EDNS0_LOCAL options
+type edns0LocalRule struct {
+	action string
+	code   uint16
+	data   []byte
+}
+
+// ends0NsidRule is a rewrite rule for EDNS0_NSID options
+type edns0NsidRule struct {
+	action string
+}
+
+// setupEdns0Opt will retrieve the EDNS0 OPT or create it if it does not exist
+func setupEdns0Opt(r *dns.Msg) *dns.OPT {
+	o := r.IsEdns0()
+	if o == nil {
+		r.SetEdns0(4096, true)
+		o = r.IsEdns0()
+	}
+	return o
+}
+
+// Rewrite will alter the request EDNS0 NSID option
+func (rule *edns0NsidRule) Rewrite(r *dns.Msg) Result {
+	result := RewriteIgnored
+	o := setupEdns0Opt(r)
+	found := false
+	for _, s := range o.Option {
+		switch e := s.(type) {
+		case *dns.EDNS0_NSID:
+			if rule.action == "replace" || rule.action == "set" {
+				e.Nsid = "" // make sure it is empty for request
+				result = RewriteDone
+			}
+			found = true
+			break
+		}
+	}
+
+	// add option if not found
+	if !found && (rule.action == "append" || rule.action == "set") {
+		o.SetDo(true)
+		o.Option = append(o.Option, &dns.EDNS0_NSID{Code: dns.EDNS0NSID, Nsid: ""})
+		result = RewriteDone
+	}
+
+	return result
+}
+
+// Rewrite will alter the request EDNS0 local options
+func (rule *edns0LocalRule) Rewrite(r *dns.Msg) Result {
+	result := RewriteIgnored
+	o := setupEdns0Opt(r)
+	found := false
+	for _, s := range o.Option {
+		switch e := s.(type) {
+		case *dns.EDNS0_LOCAL:
+			if rule.code == e.Code {
+				if rule.action == "replace" || rule.action == "set" {
+					e.Data = rule.data
+					result = RewriteDone
+				}
+				found = true
+				break
+			}
+		}
+	}
+
+	// add option if not found
+	if !found && (rule.action == "append" || rule.action == "set") {
+		o.SetDo(true)
+		var opt dns.EDNS0_LOCAL
+		opt.Code = rule.code
+		opt.Data = rule.data
+		o.Option = append(o.Option, &opt)
+		result = RewriteDone
+	}
+
+	return result
+}
+
+// newEdns0Rule creates an EDNS0 rule of the appropriate type based on the args
+func newEdns0Rule(args ...string) (Rule, error) {
+	if len(args) < 2 {
+		return nil, fmt.Errorf("Too few arguments for an EDNS0 rule")
+	}
+
+	ruleType := strings.ToLower(args[0])
+	action := strings.ToLower(args[1])
+	switch action {
+	case "append":
+	case "replace":
+	case "set":
+	default:
+		return nil, fmt.Errorf("invalid action: %q", action)
+	}
+
+	switch ruleType {
+	case "local":
+		if len(args) != 4 {
+			return nil, fmt.Errorf("EDNS0 local rules require exactly three args")
+		}
+		return newEdns0LocalRule(action, args[2], args[3])
+	case "nsid":
+		if len(args) != 2 {
+			return nil, fmt.Errorf("EDNS0 NSID rules do not accept args")
+		}
+		return &edns0NsidRule{action: action}, nil
+	default:
+		return nil, fmt.Errorf("invalid rule type %q", ruleType)
+	}
+}
+
+func newEdns0LocalRule(action, code, data string) (*edns0LocalRule, error) {
+	c, err := strconv.ParseUint(code, 0, 16)
+	if err != nil {
+		return nil, err
+	}
+
+	decoded := []byte(data)
+	if strings.HasPrefix(data, "0x") {
+		decoded, err = hex.DecodeString(data[2:])
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return &edns0LocalRule{action: action, code: uint16(c), data: decoded}, nil
+}
diff --git a/middleware/rewrite/field.go b/middleware/rewrite/field.go
deleted file mode 100644
index 2b5ae60be..000000000
--- a/middleware/rewrite/field.go
+++ /dev/null
@@ -1,11 +0,0 @@
-// Package rewrite is middleware for rewriting requests internally to something different.
-package rewrite
-
-// Fields defines additional FIELD keywords may be implemented to support more rewrite use-cases.
-// New Rule types must be added to the Fields map.
-// The type must implement `New` and `Rewrite` functions.
-var Fields = map[string]Rule{
-	"name":  NameRule{},
-	"type":  TypeRule{},
-	"class": ClassRule{},
-}
diff --git a/middleware/rewrite/name.go b/middleware/rewrite/name.go
index 6b885c5c5..69c387f10 100644
--- a/middleware/rewrite/name.go
+++ b/middleware/rewrite/name.go
@@ -1,26 +1,21 @@
-// Package rewrite is middleware for rewriting requests internally to something different.
 package rewrite
 
 import (
-	"strings"
-
 	"github.com/coredns/coredns/middleware"
+
 	"github.com/miekg/dns"
 )
 
-// NameRule is a name rewrite rule.
-type NameRule struct {
+type nameRule struct {
 	From, To string
 }
 
-// New initializes a new rule.
-func (rule NameRule) New(args ...string) Rule {
-	from, to := args[0], strings.Join(args[1:], " ")
-	return &NameRule{middleware.Name(from).Normalize(), middleware.Name(to).Normalize()}
+func newNameRule(from, to string) (Rule, error) {
+	return &nameRule{middleware.Name(from).Normalize(), middleware.Name(to).Normalize()}, nil
 }
 
 // Rewrite rewrites the the current request.
-func (rule NameRule) Rewrite(r *dns.Msg) Result {
+func (rule *nameRule) Rewrite(r *dns.Msg) Result {
 	if rule.From == r.Question[0].Name {
 		r.Question[0].Name = rule.To
 		return RewriteDone
diff --git a/middleware/rewrite/rewrite.go b/middleware/rewrite/rewrite.go
index 24e57005e..2db97b2f1 100644
--- a/middleware/rewrite/rewrite.go
+++ b/middleware/rewrite/rewrite.go
@@ -1,9 +1,13 @@
-// Package rewrite is middleware for rewriting requests internally to something different.
 package rewrite
 
 import (
+	"fmt"
+	"strings"
+
 	"github.com/coredns/coredns/middleware"
+
 	"github.com/miekg/dns"
+
 	"golang.org/x/net/context"
 )
 
@@ -52,10 +56,31 @@ func (rw Rewrite) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg
 // Name implements the Handler interface.
 func (rw Rewrite) Name() string { return "rewrite" }
 
-// Rule describes an internal location rewrite rule.
+// Rule describes a rewrite rule.
 type Rule interface {
-	// Rewrite rewrites the internal location of the current request.
+	// Rewrite rewrites the current request.
 	Rewrite(*dns.Msg) Result
-	// New returns a new rule.
-	New(...string) Rule
+}
+
+func newRule(args ...string) (Rule, error) {
+	if len(args) == 0 {
+		return nil, fmt.Errorf("No rule type specified for rewrite")
+	}
+
+	ruleType := strings.ToLower(args[0])
+	if ruleType != "edns0" && len(args) != 3 {
+		return nil, fmt.Errorf("%s rules must have exactly two arguments", ruleType)
+	}
+	switch ruleType {
+	case "name":
+		return newNameRule(args[1], args[2])
+	case "class":
+		return newClassRule(args[1], args[2])
+	case "type":
+		return newTypeRule(args[1], args[2])
+	case "edns0":
+		return newEdns0Rule(args[1:]...)
+	default:
+		return nil, fmt.Errorf("invalid rule type %q", args[0])
+	}
 }
diff --git a/middleware/rewrite/rewrite_test.go b/middleware/rewrite/rewrite_test.go
index 64d0d5eec..e4c0afc50 100644
--- a/middleware/rewrite/rewrite_test.go
+++ b/middleware/rewrite/rewrite_test.go
@@ -1,6 +1,8 @@
 package rewrite
 
 import (
+	"bytes"
+	"reflect"
 	"testing"
 
 	"github.com/coredns/coredns/middleware"
@@ -16,14 +18,73 @@ func msgPrinter(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, err
 	return 0, nil
 }
 
+func TestNewRule(t *testing.T) {
+	tests := []struct {
+		args        []string
+		shouldError bool
+		expType     reflect.Type
+	}{
+		{[]string{}, true, nil},
+		{[]string{"foo"}, true, nil},
+		{[]string{"name"}, true, nil},
+		{[]string{"name", "a.com"}, true, nil},
+		{[]string{"name", "a.com", "b.com", "c.com"}, true, nil},
+		{[]string{"name", "a.com", "b.com"}, false, reflect.TypeOf(&nameRule{})},
+		{[]string{"type"}, true, nil},
+		{[]string{"type", "a"}, true, nil},
+		{[]string{"type", "any", "a", "a"}, true, nil},
+		{[]string{"type", "any", "a"}, false, reflect.TypeOf(&typeRule{})},
+		{[]string{"type", "XY", "WV"}, true, nil},
+		{[]string{"type", "ANY", "WV"}, true, nil},
+		{[]string{"class"}, true, nil},
+		{[]string{"class", "IN"}, true, nil},
+		{[]string{"class", "ch", "in", "in"}, true, nil},
+		{[]string{"class", "ch", "in"}, false, reflect.TypeOf(&classRule{})},
+		{[]string{"class", "XY", "WV"}, true, nil},
+		{[]string{"class", "IN", "WV"}, true, nil},
+		{[]string{"edns0"}, true, nil},
+		{[]string{"edns0", "local"}, true, nil},
+		{[]string{"edns0", "local", "set"}, true, nil},
+		{[]string{"edns0", "local", "set", "0xffee"}, true, nil},
+		{[]string{"edns0", "local", "set", "65518", "abcdefg"}, false, reflect.TypeOf(&edns0LocalRule{})},
+		{[]string{"edns0", "local", "set", "0xffee", "abcdefg"}, false, reflect.TypeOf(&edns0LocalRule{})},
+		{[]string{"edns0", "local", "append", "0xffee", "abcdefg"}, false, reflect.TypeOf(&edns0LocalRule{})},
+		{[]string{"edns0", "local", "replace", "0xffee", "abcdefg"}, false, reflect.TypeOf(&edns0LocalRule{})},
+		{[]string{"edns0", "local", "foo", "0xffee", "abcdefg"}, true, nil},
+		{[]string{"edns0", "local", "set", "0xffee", "0xabcdefg"}, true, nil},
+		{[]string{"edns0", "nsid", "set", "junk"}, true, nil},
+		{[]string{"edns0", "nsid", "set"}, false, reflect.TypeOf(&edns0NsidRule{})},
+		{[]string{"edns0", "nsid", "append"}, false, reflect.TypeOf(&edns0NsidRule{})},
+		{[]string{"edns0", "nsid", "replace"}, false, reflect.TypeOf(&edns0NsidRule{})},
+		{[]string{"edns0", "nsid", "foo"}, true, nil},
+	}
+
+	for i, tc := range tests {
+		r, err := newRule(tc.args...)
+		if err == nil && tc.shouldError {
+			t.Errorf("Test %d: expected error but got success", i)
+		} else if err != nil && !tc.shouldError {
+			t.Errorf("Test %d: expected success but got error: %s", i, err)
+		}
+
+		if !tc.shouldError && reflect.TypeOf(r) != tc.expType {
+			t.Errorf("Test %d: expected %q but got %q", i, tc.expType, r)
+		}
+	}
+}
+
 func TestRewrite(t *testing.T) {
+	rules := []Rule{}
+	r, _ := newNameRule("from.nl.", "to.nl.")
+	rules = append(rules, r)
+	r, _ = newClassRule("CH", "IN")
+	rules = append(rules, r)
+	r, _ = newTypeRule("ANY", "HINFO")
+	rules = append(rules, r)
+
 	rw := Rewrite{
-		Next: middleware.HandlerFunc(msgPrinter),
-		Rules: []Rule{
-			Fields["name"].New("from.nl.", "to.nl."),
-			Fields["class"].New("CH", "IN"),
-			Fields["type"].New("ANY", "HINFO"),
-		},
+		Next:     middleware.HandlerFunc(msgPrinter),
+		Rules:    rules,
 		noRevert: true,
 	}
 
@@ -56,7 +117,7 @@ func TestRewrite(t *testing.T) {
 
 		resp := rec.Msg
 		if resp.Question[0].Name != tc.to {
-			t.Errorf("Test %d: Expected Name to be '%s' but was '%s'", i, tc.to, resp.Question[0].Name)
+			t.Errorf("Test %d: Expected Name to be %q but was %q", i, tc.to, resp.Question[0].Name)
 		}
 		if resp.Question[0].Qtype != tc.toT {
 			t.Errorf("Test %d: Expected Type to be '%d' but was '%d'", i, tc.toT, resp.Question[0].Qtype)
@@ -65,79 +126,162 @@ func TestRewrite(t *testing.T) {
 			t.Errorf("Test %d: Expected Class to be '%d' but was '%d'", i, tc.toC, resp.Question[0].Qclass)
 		}
 	}
+}
+
+func TestRewriteEDNS0Local(t *testing.T) {
+	rw := Rewrite{
+		Next:     middleware.HandlerFunc(msgPrinter),
+		noRevert: true,
+	}
 
-	/*
-		regexps := [][]string{
-			{"/reg/", ".*", "/to", ""},
-			{"/r/", "[a-z]+", "/toaz", "!.html|"},
-			{"/url/", "a([a-z0-9]*)s([A-Z]{2})", "/to/{path}", ""},
-			{"/ab/", "ab", "/ab?{query}", ".txt|"},
-			{"/ab/", "ab", "/ab?type=html&{query}", ".html|"},
-			{"/abc/", "ab", "/abc/{file}", ".html|"},
-			{"/abcd/", "ab", "/a/{dir}/{file}", ".html|"},
-			{"/abcde/", "ab", "/a#{fragment}", ".html|"},
-			{"/ab/", `.*\.jpg`, "/ajpg", ""},
-			{"/reggrp", `/ad/([0-9]+)([a-z]*)`, "/a{1}/{2}", ""},
-			{"/reg2grp", `(.*)`, "/{1}", ""},
-			{"/reg3grp", `(.*)/(.*)/(.*)`, "/{1}{2}{3}", ""},
+	tests := []struct {
+		fromOpts []dns.EDNS0
+		args     []string
+		toOpts   []dns.EDNS0
+	}{
+		{
+			[]dns.EDNS0{},
+			[]string{"local", "set", "0xffee", "0xabcdef"},
+			[]dns.EDNS0{&dns.EDNS0_LOCAL{Code: 0xffee, Data: []byte{0xab, 0xcd, 0xef}}},
+		},
+		{
+			[]dns.EDNS0{},
+			[]string{"local", "append", "0xffee", "abcdefghijklmnop"},
+			[]dns.EDNS0{&dns.EDNS0_LOCAL{Code: 0xffee, Data: []byte("abcdefghijklmnop")}},
+		},
+		{
+			[]dns.EDNS0{},
+			[]string{"local", "replace", "0xffee", "abcdefghijklmnop"},
+			[]dns.EDNS0{},
+		},
+		{
+			[]dns.EDNS0{},
+			[]string{"nsid", "set"},
+			[]dns.EDNS0{&dns.EDNS0_NSID{Code: dns.EDNS0NSID, Nsid: ""}},
+		},
+		{
+			[]dns.EDNS0{},
+			[]string{"nsid", "append"},
+			[]dns.EDNS0{&dns.EDNS0_NSID{Code: dns.EDNS0NSID, Nsid: ""}},
+		},
+		{
+			[]dns.EDNS0{},
+			[]string{"nsid", "replace"},
+			[]dns.EDNS0{},
+		},
+	}
+
+	ctx := context.TODO()
+	for i, tc := range tests {
+		m := new(dns.Msg)
+		m.SetQuestion("example.com.", dns.TypeA)
+		m.Question[0].Qclass = dns.ClassINET
+
+		r, err := newEdns0Rule(tc.args...)
+		if err != nil {
+			t.Errorf("Error creating test rule: %s", err)
+			continue
 		}
+		rw.Rules = []Rule{r}
 
-		for _, regexpRule := range regexps {
-			var ext []string
-			if s := strings.Split(regexpRule[3], "|"); len(s) > 1 {
-				ext = s[:len(s)-1]
-			}
-			rule, err := NewComplexRule(regexpRule[0], regexpRule[1], regexpRule[2], 0, ext, nil)
-			if err != nil {
-				t.Fatal(err)
-			}
-			rw.Rules = append(rw.Rules, rule)
+		rec := dnsrecorder.New(&test.ResponseWriter{})
+		rw.ServeDNS(ctx, rec, m)
+
+		resp := rec.Msg
+		o := resp.IsEdns0()
+		if o == nil {
+			t.Errorf("Test %d: EDNS0 options not set", i)
+			continue
 		}
-	*/
-	/*
-		statusTests := []struct {
-			status         int
-			base           string
-			to             string
-			regexp         string
-			statusExpected bool
-		}{
-			{400, "/status", "", "", true},
-			{400, "/ignore", "", "", false},
-			{400, "/", "", "^/ignore", false},
-			{400, "/", "", "(.*)", true},
-			{400, "/status", "", "", true},
+		if !optsEqual(o.Option, tc.toOpts) {
+			t.Errorf("Test %d: Expected %v but got %v", i, tc.toOpts, o)
 		}
+	}
+}
 
-		for i, s := range statusTests {
-			urlPath := fmt.Sprintf("/status%d", i)
-			rule, err := NewComplexRule(s.base, s.regexp, s.to, s.status, nil, nil)
-			if err != nil {
-				t.Fatalf("Test %d: No error expected for rule but found %v", i, err)
-			}
-			rw.Rules = []Rule{rule}
-			req, err := http.NewRequest("GET", urlPath, nil)
-			if err != nil {
-				t.Fatalf("Test %d: Could not create HTTP request: %v", i, err)
-			}
+func TestEdns0LocalMultiRule(t *testing.T) {
+	rules := []Rule{}
+	r, _ := newEdns0Rule("local", "replace", "0xffee", "abcdef")
+	rules = append(rules, r)
+	r, _ = newEdns0Rule("local", "set", "0xffee", "fedcba")
+	rules = append(rules, r)
+
+	rw := Rewrite{
+		Next:     middleware.HandlerFunc(msgPrinter),
+		Rules:    rules,
+		noRevert: true,
+	}
+
+	tests := []struct {
+		fromOpts []dns.EDNS0
+		toOpts   []dns.EDNS0
+	}{
+		{
+			nil,
+			[]dns.EDNS0{&dns.EDNS0_LOCAL{Code: 0xffee, Data: []byte("fedcba")}},
+		},
+		{
+			[]dns.EDNS0{&dns.EDNS0_LOCAL{Code: 0xffee, Data: []byte("foobar")}},
+			[]dns.EDNS0{&dns.EDNS0_LOCAL{Code: 0xffee, Data: []byte("abcdef")}},
+		},
+	}
 
-			rec := httptest.NewRecorder()
-			code, err := rw.ServeHTTP(rec, req)
-			if err != nil {
-				t.Fatalf("Test %d: No error expected for handler but found %v", i, err)
+	ctx := context.TODO()
+	for i, tc := range tests {
+		m := new(dns.Msg)
+		m.SetQuestion("example.com.", dns.TypeA)
+		m.Question[0].Qclass = dns.ClassINET
+		if tc.fromOpts != nil {
+			o := m.IsEdns0()
+			if o == nil {
+				m.SetEdns0(4096, true)
+				o = m.IsEdns0()
 			}
-			if s.statusExpected {
-				if rec.Body.String() != "" {
-					t.Errorf("Test %d: Expected empty body but found %s", i, rec.Body.String())
+			o.Option = append(o.Option, tc.fromOpts...)
+		}
+		rec := dnsrecorder.New(&test.ResponseWriter{})
+		rw.ServeDNS(ctx, rec, m)
+
+		resp := rec.Msg
+		o := resp.IsEdns0()
+		if o == nil {
+			t.Errorf("Test %d: EDNS0 options not set", i)
+			continue
+		}
+		if !optsEqual(o.Option, tc.toOpts) {
+			t.Errorf("Test %d: Expected %v but got %v", i, tc.toOpts, o)
+		}
+	}
+}
+
+func optsEqual(a, b []dns.EDNS0) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i := range a {
+		switch aa := a[i].(type) {
+		case *dns.EDNS0_LOCAL:
+			if bb, ok := b[i].(*dns.EDNS0_LOCAL); ok {
+				if aa.Code != bb.Code {
+					return false
 				}
-				if code != s.status {
-					t.Errorf("Test %d: Expected status code %d found %d", i, s.status, code)
+				if !bytes.Equal(aa.Data, bb.Data) {
+					return false
 				}
 			} else {
-				if code != 0 {
-					t.Errorf("Test %d: Expected no status code found %d", i, code)
+				return false
+			}
+		case *dns.EDNS0_NSID:
+			if bb, ok := b[i].(*dns.EDNS0_NSID); ok {
+				if aa.Nsid != bb.Nsid {
+					return false
 				}
+			} else {
+				return false
 			}
+		default:
+			return false
 		}
-	*/
+	}
+	return true
 }
diff --git a/middleware/rewrite/setup.go b/middleware/rewrite/setup.go
index 9befa30a1..156129f70 100644
--- a/middleware/rewrite/setup.go
+++ b/middleware/rewrite/setup.go
@@ -1,8 +1,6 @@
 package rewrite
 
 import (
-	"log"
-
 	"github.com/coredns/coredns/core/dnsserver"
 	"github.com/coredns/coredns/middleware"
 
@@ -30,93 +28,15 @@ func setup(c *caddy.Controller) error {
 }
 
 func rewriteParse(c *caddy.Controller) ([]Rule, error) {
-	var simpleRules []Rule
-	var regexpRules []Rule
+	var rules []Rule
 
 	for c.Next() {
-		var rule Rule
-		/*
-			var base = "."
-			var err error
-			var pattern, to string
-			var status int
-			var ifs []If
-			var ext []string
-		*/
-
 		args := c.RemainingArgs()
-
-		switch len(args) {
-		case 1:
-			/*
-				base = args[0]
-				fallthrough
-			*/
-		case 0:
-			/*
-				for c.NextBlock() {
-					switch c.Val() {
-					case "r", "regexp":
-						if !c.NextArg() {
-							return nil, c.ArgErr()
-						}
-						pattern = c.Val()
-					case "to":
-						args1 := c.RemainingArgs()
-						if len(args1) == 0 {
-							return nil, c.ArgErr()
-						}
-						to = strings.Join(args1, " ")
-					case "ext": // TODO(miek): fix or remove
-						args1 := c.RemainingArgs()
-						if len(args1) == 0 {
-							return nil, c.ArgErr()
-						}
-						ext = args1
-					case "if":
-						args1 := c.RemainingArgs()
-						if len(args1) != 3 {
-							return nil, c.ArgErr()
-						}
-						ifCond, err := NewIf(args1[0], args1[1], args1[2])
-						if err != nil {
-							return nil, err
-						}
-						ifs = append(ifs, ifCond)
-					case "status": // TODO(miek): fix or remove
-						if !c.NextArg() {
-							return nil, c.ArgErr()
-						}
-						status, _ = strconv.Atoi(c.Val())
-						if status < 200 || (status > 299 && status < 400) || status > 499 {
-							return nil, c.Err("status must be 2xx or 4xx")
-						}
-					default:
-						return nil, c.ArgErr()
-					}
-				}
-				// ensure to or status is specified
-				if to == "" && status == 0 {
-					return nil, c.ArgErr()
-				}
-				// TODO(miek): complex rules
-				if rule, err = NewComplexRule(base, pattern, to, status, ext, ifs); err != nil {
-					return nil, err
-				}
-				regexpRules = append(regexpRules, rule)
-			*/
-
-		// the only unhandled case is 2 and above
-		default:
-			if _, ok := Fields[args[0]]; ok {
-				rule = Fields[args[0]].New(args[1:]...)
-				simpleRules = append(simpleRules, rule)
-			} else {
-				log.Printf("[WARN] %s is not a valid field, ignore %s", args[0], args)
-			}
+		rule, err := newRule(args...)
+		if err != nil {
+			return nil, err
 		}
+		rules = append(rules, rule)
 	}
-
-	// put simple rules in front to avoid regexp computation for them
-	return append(simpleRules, regexpRules...), nil
+	return rules, nil
 }
diff --git a/middleware/rewrite/setup_test.go b/middleware/rewrite/setup_test.go
new file mode 100644
index 000000000..67ef88e18
--- /dev/null
+++ b/middleware/rewrite/setup_test.go
@@ -0,0 +1,25 @@
+package rewrite
+
+import (
+	"testing"
+
+	"github.com/mholt/caddy"
+)
+
+func TestParse(t *testing.T) {
+	c := caddy.NewTestController("dns", `rewrite`)
+	_, err := rewriteParse(c)
+	if err == nil {
+		t.Errorf("Expected error but found nil for `rewrite`")
+	}
+	c = caddy.NewTestController("dns", `rewrite name`)
+	_, err = rewriteParse(c)
+	if err == nil {
+		t.Errorf("Expected error but found nil for `rewrite name`")
+	}
+	c = caddy.NewTestController("dns", `rewrite name a.com b.com`)
+	_, err = rewriteParse(c)
+	if err != nil {
+		t.Errorf("Expected success but found %s for `rewrite name a.com b.com`", err)
+	}
+}
diff --git a/middleware/rewrite/type.go b/middleware/rewrite/type.go
index a04361c79..c2b7866d7 100644
--- a/middleware/rewrite/type.go
+++ b/middleware/rewrite/type.go
@@ -2,24 +2,31 @@
 package rewrite
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/miekg/dns"
 )
 
-// TypeRule is a type rewrite rule.
-type TypeRule struct {
+// typeRule is a type rewrite rule.
+type typeRule struct {
 	fromType, toType uint16
 }
 
-// New initializes a rule.
-func (rule TypeRule) New(args ...string) Rule {
-	from, to := args[0], strings.Join(args[1:], " ")
-	return &TypeRule{dns.StringToType[from], dns.StringToType[to]}
+func newTypeRule(fromS, toS string) (Rule, error) {
+	var from, to uint16
+	var ok bool
+	if from, ok = dns.StringToType[strings.ToUpper(fromS)]; !ok {
+		return nil, fmt.Errorf("invalid type %q", strings.ToUpper(fromS))
+	}
+	if to, ok = dns.StringToType[strings.ToUpper(toS)]; !ok {
+		return nil, fmt.Errorf("invalid type %q", strings.ToUpper(toS))
+	}
+	return &typeRule{fromType: from, toType: to}, nil
 }
 
 // Rewrite rewrites the the current request.
-func (rule TypeRule) Rewrite(r *dns.Msg) Result {
+func (rule *typeRule) Rewrite(r *dns.Msg) Result {
 	if rule.fromType > 0 && rule.toType > 0 {
 		if r.Question[0].Qtype == rule.fromType {
 			r.Question[0].Qtype = rule.toType
diff --git a/test/middleware_dnssec_test.go b/test/middleware_dnssec_test.go
index 819ee66d7..34df9bb0f 100644
--- a/test/middleware_dnssec_test.go
+++ b/test/middleware_dnssec_test.go
@@ -23,7 +23,7 @@ func TestLookupBalanceRewriteCacheDnssec(t *testing.T) {
 
 	corefile := `example.org:0 {
     file ` + name + `
-    rewrite ANY HINFO
+    rewrite type ANY HINFO
     dnssec {
         key file ` + base + `
     }
diff --git a/test/middleware_test.go b/test/middleware_test.go
index ef468cdf7..10bd3864c 100644
--- a/test/middleware_test.go
+++ b/test/middleware_test.go
@@ -20,7 +20,7 @@ func benchmarkLookupBalanceRewriteCache(b *testing.B) {
 
 	corefile := `example.org:0 {
     file ` + name + `
-    rewrite ANY HINFO
+    rewrite type ANY HINFO
     loadbalance
 }
 `
diff --git a/test/rewrite_test.go b/test/rewrite_test.go
new file mode 100644
index 000000000..9aedd7417
--- /dev/null
+++ b/test/rewrite_test.go
@@ -0,0 +1,94 @@
+package test
+
+import (
+	"bytes"
+	"io/ioutil"
+	"log"
+	"testing"
+
+	"github.com/miekg/dns"
+)
+
+func TestRewrite(t *testing.T) {
+	t.Parallel()
+	corefile := `.:0 {
+       rewrite type MX a
+       rewrite edns0 local set 0xffee hello-world
+       erratic . {
+	drop 0
+	}
+}`
+
+	i, err := CoreDNSServer(corefile)
+	if err != nil {
+		t.Fatalf("Could not get CoreDNS serving instance: %s", err)
+	}
+
+	udp, _ := CoreDNSServerPorts(i, 0)
+	if udp == "" {
+		t.Fatalf("Could not get UDP listening port")
+	}
+	defer i.Stop()
+
+	log.SetOutput(ioutil.Discard)
+
+	testMX(t, udp)
+	testEdns0(t, udp)
+}
+
+func testMX(t *testing.T, server string) {
+	m := new(dns.Msg)
+	m.SetQuestion("example.com.", dns.TypeMX)
+
+	r, err := dns.Exchange(m, server)
+	if err != nil {
+		t.Fatalf("Expected to receive reply, but didn't: %s", err)
+	}
+
+	// expect answer section with A record in it
+	if len(r.Answer) == 0 {
+		t.Error("Expected to at least one RR in the answer section, got none")
+	}
+	if r.Answer[0].Header().Rrtype != dns.TypeA {
+		t.Errorf("Expected RR to A, got: %d", r.Answer[0].Header().Rrtype)
+	}
+	if r.Answer[0].(*dns.A).A.String() != "192.0.2.53" {
+		t.Errorf("Expected 192.0.2.53, got: %s", r.Answer[0].(*dns.A).A.String())
+	}
+}
+
+func testEdns0(t *testing.T, server string) {
+	m := new(dns.Msg)
+	m.SetQuestion("example.com.", dns.TypeA)
+
+	r, err := dns.Exchange(m, server)
+	if err != nil {
+		t.Fatalf("Expected to receive reply, but didn't: %s", err)
+	}
+
+	// expect answer section with A record in it
+	if len(r.Answer) == 0 {
+		t.Error("Expected to at least one RR in the answer section, got none")
+	}
+	if r.Answer[0].Header().Rrtype != dns.TypeA {
+		t.Errorf("Expected RR to A, got: %d", r.Answer[0].Header().Rrtype)
+	}
+	if r.Answer[0].(*dns.A).A.String() != "192.0.2.53" {
+		t.Errorf("Expected 192.0.2.53, got: %s", r.Answer[0].(*dns.A).A.String())
+	}
+	o := r.IsEdns0()
+	if o == nil || len(o.Option) == 0 {
+		t.Error("Expected EDNS0 options but got none")
+	} else {
+		if e, ok := o.Option[0].(*dns.EDNS0_LOCAL); ok {
+			if e.Code != 0xffee {
+				t.Errorf("Expected EDNS_LOCAL code 0xffee but got %x", e.Code)
+			}
+			if !bytes.Equal(e.Data, []byte("hello-world")) {
+				t.Errorf("Expected EDNS_LOCAL data 'hello-world' but got %q", e.Data)
+			}
+		} else {
+			t.Errorf("Expected EDNS0_LOCAL but got %v", o.Option[0])
+		}
+	}
+}