Merge pull request #86 from digitalocean/bsomogyi/metadata-matchparser

Extend Metadata Matchparser with Mask

Author: btsomogyi

ovs/match.go

@@ -1240,6 +1240,48 @@ func UnsetState(state CTState) string {
 	return fmt.Sprintf("-%s", state)
 }
 
+// Metadata returns a Match that matches the given Metadata exactly.
+func Metadata(id uint64) Match {
+	return &metadataMatch{
+		data: id,
+		mask: 0,
+	}
+}
+
+// MetadataWithMask returns a Match with specified Metadata and mask.
+func MetadataWithMask(id, mask uint64) Match {
+	return &metadataMatch{
+		data: id,
+		mask: mask,
+	}
+}
+
+var _ Match = &metadataMatch{}
+
+// A metadataMatch is a Match against a Metadata field.
+type metadataMatch struct {
+	data uint64
+	mask uint64
+}
+
+// GoString implements Match.
+func (m *metadataMatch) GoString() string {
+	if m.mask > 0 {
+		return fmt.Sprintf("ovs.MetadataWithMask(%#x, %#x)", m.data, m.mask)
+	}
+
+	return fmt.Sprintf("ovs.Metadata(%#x)", m.data)
+}
+
+// MarshalText implements Match.
+func (m *metadataMatch) MarshalText() ([]byte, error) {
+	if m.mask == 0 {
+		return bprintf("%s=%#x", metadata, m.data), nil
+	}
+
+	return bprintf("%s=%#x/%#x", metadata, m.data, m.mask), nil
+}
+
 // TCPFlags matches packets using their enabled TCP flags, when matching TCP
 // flags on a TCP segment.   Use the SetTCPFlag and UnsetTCPFlag functions to
 // populate the parameter list for this function.
@@ -1381,30 +1423,6 @@ func (m *tunnelMatch) MarshalText() ([]byte, error) {
 	return matchIPv4AddressOrCIDR(fmt.Sprintf("tun_%s", m.srcdst), m.ip)
 }
 
-// Metadata returns a Match that matches the given metadata value.
-func Metadata(m uint64) Match {
-	return &metadataMatch{
-		m: m,
-	}
-}
-
-var _ Match = &metadataMatch{}
-
-// A metadataMatch is a Match against a metadata value.
-type metadataMatch struct {
-	m uint64
-}
-
-// GoString implements Match.
-func (m *metadataMatch) GoString() string {
-	return fmt.Sprintf("ovs.Metadata(%#x)", m.m)
-}
-
-// MarshalText implements Match.
-func (m *metadataMatch) MarshalText() ([]byte, error) {
-	return bprintf("%s=%#x", metadata, m.m), nil
-}
-
 // matchIPv4AddressOrCIDR attempts to create a Match using the specified key
 // and input string, which could be interpreted as an IPv4 address or IPv4
 // CIDR block.

ovs/matchparser.go

@@ -86,6 +86,8 @@ func parseMatch(key string, value string) (Match, error) {
 		return IPv6Source(value), nil
 	case ipv6DST:
 		return IPv6Destination(value), nil
+	case metadata:
+		return parseMetadata(value)
 	case tunv6SRC:
 		return IPv6Source(value), nil
 	case tunv6DST:
@@ -479,6 +481,39 @@ func parseCTMark(value string) (Match, error) {
 	}
 }
 
+// parseMetadata parses a Metadata Match from value.
+func parseMetadata(value string) (Match, error) {
+	var values []uint64
+	for _, s := range strings.Split(value, "/") {
+		if !strings.HasPrefix(s, hexPrefix) {
+			v, err := strconv.Atoi(s)
+			if err != nil {
+				return nil, err
+			}
+
+			values = append(values, uint64(v))
+			continue
+		}
+
+		v, err := parseHexUint64(s)
+		if err != nil {
+			return nil, err
+		}
+
+		values = append(values, v)
+	}
+
+	switch len(values) {
+	case 1:
+		return Metadata(values[0]), nil
+	case 2:
+		return MetadataWithMask(values[0], values[1]), nil
+	// Match had too many parts, e.g. "metadata=10/10/10"
+	default:
+		return nil, fmt.Errorf("invalid metadata match: %q", value)
+	}
+}
+
 // parseTunID parses a tunID Match from value.
 func parseTunID(value string) (Match, error) {
 	var values []uint64