Fix SRV record handling when target is shortname (#422)

* models/record.go: SRV targets are case insensitive. Downcase them.
* models/t_srv.go: Rename setTargetIntAndStrings() to setTargetSRVIntAndStrings() (makes it easier to search for /setTargetSRV/).
* pkg/js/parse_tests/021-srv.js*: SRV: Add parse_tests
* pkg/normalize/validate.go: SRV targets are hostnames, turn into FQDNs.
* Add  #rtype_variations warnings for future developers

models/record.go

@@ -292,10 +292,12 @@ func downcase(recs []*RecordConfig) {
 	for _, r := range recs {
 		r.Name = strings.ToLower(r.Name)
 		r.NameFQDN = strings.ToLower(r.NameFQDN)
-		switch r.Type {
+		switch r.Type { // #rtype_variations
-		case "ANAME", "CNAME", "MX", "NS", "PTR":
+		case "ANAME", "CNAME", "MX", "NS", "PTR", "SRV":
+			// These record types have a target that is case insensitive, so we downcase it.
 			r.Target = strings.ToLower(r.Target)
-		case "A", "AAAA", "ALIAS", "CAA", "IMPORT_TRANSFORM", "SRV", "TLSA", "TXT", "SOA", "CF_REDIRECT", "CF_TEMP_REDIRECT":
+		case "A", "AAAA", "ALIAS", "CAA", "IMPORT_TRANSFORM", "TLSA", "TXT", "SOA", "CF_REDIRECT", "CF_TEMP_REDIRECT":
+			// These record types have a target that is case sensitive, or is an IP address. We leave them alone.
 			// Do nothing.
 		default:
 			// TODO: we'd like to panic here, but custom record types complicate things.

models/t_srv.go

@@ -22,8 +22,8 @@ func (rc *RecordConfig) SetTargetSRV(priority, weight, port uint16, target strin
 	return nil
 }
 
-// setTargetIntAndStrings is like SetTargetSRV but accepts priority as an int, the other parameters as strings.
+// setTargetSRVIntAndStrings is like SetTargetSRV but accepts priority as an int, the other parameters as strings.
-func (rc *RecordConfig) setTargetIntAndStrings(priority uint16, weight, port, target string) (err error) {
+func (rc *RecordConfig) setTargetSRVIntAndStrings(priority uint16, weight, port, target string) (err error) {
 	var i64weight, i64port uint64
 	if i64weight, err = strconv.ParseUint(weight, 10, 16); err == nil {
 		if i64port, err = strconv.ParseUint(port, 10, 16); err == nil {
@@ -37,7 +37,7 @@ func (rc *RecordConfig) setTargetIntAndStrings(priority uint16, weight, port, ta
 func (rc *RecordConfig) SetTargetSRVStrings(priority, weight, port, target string) (err error) {
 	var i64priority uint64
 	if i64priority, err = strconv.ParseUint(priority, 10, 16); err == nil {
-		return rc.setTargetIntAndStrings(uint16(i64priority), weight, port, target)
+		return rc.setTargetSRVIntAndStrings(uint16(i64priority), weight, port, target)
 	}
 	return errors.Wrap(err, "SRV value too big for uint16")
 }
@@ -51,7 +51,7 @@ func (rc *RecordConfig) SetTargetSRVPriorityString(priority uint16, s string) er
 	if len(part) != 3 {
 		return errors.Errorf("SRV value does not contain 3 fields: (%#v)", s)
 	}
-	return rc.setTargetIntAndStrings(priority, part[0], part[1], part[2])
+	return rc.setTargetSRVIntAndStrings(priority, part[0], part[1], part[2])
 }
 
 // SetTargetSRVString is like SetTargetSRV but accepts one big string to be parsed.

pkg/js/parse_tests/021-srv.js

@@ -0,0 +1,7 @@
+D("foo.com","none"
+  , SRV('_ntp._udp', 1, 100, 123, 'one.foo.com.')
+  , SRV('_ntp._udp', 2, 100, 123, 'two')
+  , SRV('_ntp._udp', 3, 100, 123, 'localhost')
+  , SRV('_ntp._udp', 4, 100, 123, 'three.example.com.')
+  , SRV('_ntp._udp', 0, 0, 1, 'zeros')
+);

pkg/js/parse_tests/021-srv.json

@@ -0,0 +1,51 @@
+{
+  "dns_providers": [],
+  "domains": [
+    {
+      "dnsProviders": {},
+      "name": "foo.com",
+      "records": [
+        {
+          "name": "_ntp._udp",
+          "srvport": 123,
+          "srvpriority": 1,
+          "srvweight": 100,
+          "target": "one.foo.com.",
+          "type": "SRV"
+        },
+        {
+          "name": "_ntp._udp",
+          "srvport": 123,
+          "srvpriority": 2,
+          "srvweight": 100,
+          "target": "two",
+          "type": "SRV"
+        },
+        {
+          "name": "_ntp._udp",
+          "srvport": 123,
+          "srvpriority": 3,
+          "srvweight": 100,
+          "target": "localhost",
+          "type": "SRV"
+        },
+        {
+          "name": "_ntp._udp",
+          "srvport": 123,
+          "srvpriority": 4,
+          "srvweight": 100,
+          "target": "three.example.com.",
+          "type": "SRV"
+        },
+        {
+          "name": "_ntp._udp",
+          "srvport": 1,
+          "target": "zeros",
+          "type": "SRV"
+        }
+      ],
+      "registrar": "none"
+    }
+  ],
+  "registrars": []
+}

pkg/normalize/validate.go

@@ -285,7 +285,11 @@ func NormalizeAndValidateConfig(config *models.DNSConfig) (errs []error) {
 			}
 
 			// Canonicalize Targets.
-			if rec.Type == "CNAME" || rec.Type == "MX" || rec.Type == "NS" {
+			if rec.Type == "CNAME" || rec.Type == "MX" || rec.Type == "NS" || rec.Type == "SRV" {
+				// #rtype_variations
+				// These record types have a target that is a hostname.
+				// We normalize them to a FQDN so there is less variation to handle.  If a
+				// provider API requires a shortname, the provider must do the shortening.
 				rec.SetTarget(dnsutil.AddOrigin(rec.GetTargetField(), domain.Name+"."))
 			} else if rec.Type == "A" || rec.Type == "AAAA" {
 				rec.SetTarget(net.ParseIP(rec.GetTargetField()).String())