Initial support for Connection Attributes

go/mysql/constants.go

@@ -114,9 +114,9 @@ const (
 	// Client supports plugin authentication.
 	CapabilityClientPluginAuth = 1 << 19
 
-	// CLIENT_CONNECT_ATTRS 1 << 20
+	// CapabilityClientConnAttr is CLIENT_CONNECT_ATTRS
 	// Permits connection attributes in Protocol::HandshakeResponse41.
-	// Not yet supported.
+	CapabilityClientConnAttr = 1 << 20
 
 	// CapabilityClientPluginAuthLenencClientData is CLIENT_PLUGIN_AUTH_LENENC_CLIENT_DATA
 	CapabilityClientPluginAuthLenencClientData = 1 << 21

go/mysql/server.go

@@ -470,7 +470,8 @@ func (c *Conn) writeHandshakeV10(serverVersion string, authServer AuthServer, en
 		CapabilityClientMultiResults |
 		CapabilityClientPluginAuth |
 		CapabilityClientPluginAuthLenencClientData |
-		CapabilityClientDeprecateEOF
+		CapabilityClientDeprecateEOF |
+		CapabilityClientConnAttr
 	if enableTLS {
 		capabilities |= CapabilityClientSSL
 	}
@@ -669,11 +670,66 @@ func (l *Listener) parseClientHandshakePacket(c *Conn, firstTime bool, data []by
 		authMethod = MysqlNativePassword
 	}
 
-	// FIXME(alainjobart) Add CLIENT_CONNECT_ATTRS parsing if we need it.
+	// Decode connection attributes send by the client
+	if clientFlags&CapabilityClientConnAttr != 0 {
+		var attrs map[string]string
+		var err error
+		attrs, pos, err = parseConnAttrs(data, pos)
+		if err != nil {
+			return "", "", nil, err
+		}
+		log.Infof("Connection Attributes: %-v", attrs)
+	}
 
 	return username, authMethod, authResponse, nil
 }
 
+func parseConnAttrs(data []byte, pos int) (map[string]string, int, error) {
+	var attrLen uint64
+
+	attrLen, pos, ok := readLenEncInt(data, pos)
+	if !ok {
+		return nil, 0, fmt.Errorf("parseClientHandshakePacket: can't read connection attributes variable length")
+	}
+
+	var attrLenRead uint64
+
+	attrs := make(map[string]string)
+
+	for attrLenRead < attrLen {
+		var keyLen byte
+		keyLen, pos, ok = readByte(data, pos)
+		if !ok {
+			return nil, 0, fmt.Errorf("parseClientHandshakePacket: can't read connection attribute key length")
+		}
+		attrLenRead += uint64(keyLen) + 1
+
+		var connAttrKey []byte
+		connAttrKey, pos, ok = readBytesCopy(data, pos, int(keyLen))
+		if !ok {
+			return nil, 0, fmt.Errorf("parseClientHandshakePacket: can't read connection attribute key")
+		}
+
+		var valLen byte
+		valLen, pos, ok = readByte(data, pos)
+		if !ok {
+			return nil, 0, fmt.Errorf("parseClientHandshakePacket: can't read connection attribute value length")
+		}
+		attrLenRead += uint64(valLen) + 1
+
+		var connAttrVal []byte
+		connAttrVal, pos, ok = readBytesCopy(data, pos, int(valLen))
+		if !ok {
+			return nil, 0, fmt.Errorf("parseClientHandshakePacket: can't read connection attribute value")
+		}
+
+		attrs[string(connAttrKey[:])] = string(connAttrVal[:])
+	}
+
+	return attrs, pos, nil
+
+}
+
 // writeAuthSwitchRequest writes an auth switch request packet.
 func (c *Conn) writeAuthSwitchRequest(pluginName string, pluginData []byte) error {
 	length := 1 + // AuthSwitchRequestPacket

go/mysql/server_test.go

@@ -1269,3 +1269,39 @@ func TestListenerShutdown(t *testing.T) {
 		t.Fatalf("Ping should fail after shutdown")
 	}
 }
+
+func TestParseConnAttrs(t *testing.T) {
+	expected := map[string]string{
+		"_client_version": "8.0.11",
+		"program_name":    "mysql",
+		"_pid":            "22850",
+		"_platform":       "x86_64",
+		"_os":             "linux-glibc2.12",
+		"_client_name":    "libmysql",
+	}
+
+	data := []byte{0x70, 0x04, 0x5f, 0x70, 0x69, 0x64, 0x05, 0x32, 0x32, 0x38, 0x35, 0x30, 0x09, 0x5f, 0x70, 0x6c,
+		0x61, 0x74, 0x66, 0x6f, 0x72, 0x6d, 0x06, 0x78, 0x38, 0x36, 0x5f, 0x36, 0x34, 0x03, 0x5f, 0x6f,
+		0x73, 0x0f, 0x6c, 0x69, 0x6e, 0x75, 0x78, 0x2d, 0x67, 0x6c, 0x69, 0x62, 0x63, 0x32, 0x2e, 0x31,
+		0x32, 0x0c, 0x5f, 0x63, 0x6c, 0x69, 0x65, 0x6e, 0x74, 0x5f, 0x6e, 0x61, 0x6d, 0x65, 0x08, 0x6c,
+		0x69, 0x62, 0x6d, 0x79, 0x73, 0x71, 0x6c, 0x0f, 0x5f, 0x63, 0x6c, 0x69, 0x65, 0x6e, 0x74, 0x5f,
+		0x76, 0x65, 0x72, 0x73, 0x69, 0x6f, 0x6e, 0x06, 0x38, 0x2e, 0x30, 0x2e, 0x31, 0x31, 0x0c, 0x70,
+		0x72, 0x6f, 0x67, 0x72, 0x61, 0x6d, 0x5f, 0x6e, 0x61, 0x6d, 0x65, 0x05, 0x6d, 0x79, 0x73, 0x71, 0x6c}
+
+	attrs, pos, err := parseConnAttrs(data, 0)
+	if err != nil {
+		t.Fatalf("Failed to read connection attributes: %v", err)
+	}
+	if pos != 113 {
+		t.Fatalf("Unexpeded pos after reading connection attributes: %d intead of 113", pos)
+	}
+	for k, v := range expected {
+		if val, ok := attrs[k]; ok {
+			if val != v {
+				t.Fatalf("Unexpected value found in attrs for key %s: got %s expected %s", k, val, v)
+			}
+		} else {
+			t.Fatalf("Error reading key %s from connection attributes: attrs: %-v", k, attrs)
+		}
+	}
+}