| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| package nmserial |
| |
| import ( |
| "bufio" |
| "encoding/base64" |
| "encoding/binary" |
| "encoding/hex" |
| "errors" |
| "fmt" |
| "sync" |
| "time" |
| |
| log "github.com/Sirupsen/logrus" |
| "github.com/joaojeronimo/go-crc16" |
| "github.com/runtimeco/go-coap" |
| "github.com/tarm/serial" |
| |
| "mynewt.apache.org/newt/util" |
| "mynewt.apache.org/newtmgr/nmxact/sesn" |
| ) |
| |
| type XportCfg struct { |
| DevPath string |
| Baud int |
| Mtu int |
| ReadTimeout time.Duration |
| } |
| |
| var errTimeout error = errors.New("Timeout reading from serial connection") |
| |
| func NewXportCfg() *XportCfg { |
| return &XportCfg{ |
| ReadTimeout: 10 * time.Second, |
| Mtu: 512, |
| } |
| } |
| |
| type SerialXport struct { |
| cfg *XportCfg |
| port *serial.Port |
| scanner *bufio.Scanner |
| |
| wg sync.WaitGroup |
| sync.Mutex |
| closing bool |
| |
| reqSesn *SerialSesn |
| acceptSesn *SerialSesn |
| rspSesn *SerialSesn |
| |
| pkt *Packet |
| } |
| |
| func NewSerialXport(cfg *XportCfg) *SerialXport { |
| return &SerialXport{ |
| cfg: cfg, |
| } |
| } |
| |
| func (sx *SerialXport) BuildSesn(cfg sesn.SesnCfg) (sesn.Sesn, error) { |
| return NewSerialSesn(sx, cfg) |
| } |
| |
| func (sx *SerialXport) acceptServerSesn(sl *SerialSesn) (*SerialSesn, error) { |
| sc := sesn.NewSesnCfg() |
| sc.MgmtProto = sesn.MGMT_PROTO_COAP_SERVER |
| sc.TxFilterCb = sl.cfg.TxFilterCb |
| sc.RxFilterCb = sl.cfg.RxFilterCb |
| |
| s, err := NewSerialSesn(sx, sc) |
| if err != nil { |
| return nil, fmt.Errorf("NewSesn():%v", err) |
| } |
| err = s.Open() |
| if err != nil { |
| return nil, fmt.Errorf("Open():%v", err) |
| } |
| sl.connChan <- s |
| sx.setReqSesn(s) |
| |
| return s, nil |
| } |
| |
| func (sx *SerialXport) Start() error { |
| c := &serial.Config{ |
| Name: sx.cfg.DevPath, |
| Baud: sx.cfg.Baud, |
| ReadTimeout: sx.cfg.ReadTimeout, |
| } |
| |
| var err error |
| sx.port, err = serial.OpenPort(c) |
| if err != nil { |
| return err |
| } |
| |
| err = sx.port.Flush() |
| if err != nil { |
| return err |
| } |
| |
| sx.wg.Add(1) |
| go func() { |
| defer sx.wg.Done() |
| |
| // Most of the reading will be done line by line, use the |
| // bufio.Scanner to do this |
| sx.scanner = bufio.NewScanner(sx.port) |
| |
| for { |
| msg, err := sx.Rx() |
| sx.Lock() |
| if err != nil { |
| if sx.rspSesn != nil { |
| sx.rspSesn.errChan <- err |
| } |
| } |
| if sx.closing { |
| sx.Unlock() |
| return |
| } |
| if msg == nil { |
| sx.Unlock() |
| continue |
| } |
| if len(msg) >= 4 { |
| if sx.reqSesn != nil || sx.acceptSesn != nil { |
| msgType := coap.COAPCode(msg[1]) |
| if msgType <= coap.DELETE { |
| if sx.reqSesn != nil { |
| sx.reqSesn.msgChan <- msg |
| sx.Unlock() |
| continue |
| } |
| if sx.acceptSesn != nil { |
| s, err := sx.acceptServerSesn( |
| sx.acceptSesn) |
| if err != nil { |
| log.Errorf("Cannot create server sesn: %v", err) |
| sx.Unlock() |
| continue |
| } |
| s.msgChan <- msg |
| sx.Unlock() |
| continue |
| } |
| } |
| } |
| } |
| if sx.rspSesn != nil { |
| sx.rspSesn.msgChan <- msg |
| } |
| sx.Unlock() |
| } |
| |
| }() |
| return nil |
| } |
| |
| func (sx *SerialXport) setRspSesn(s *SerialSesn) error { |
| sx.Lock() |
| defer sx.Unlock() |
| |
| if sx.closing { |
| return fmt.Errorf("Transport closed") |
| } |
| if s != nil && sx.rspSesn != nil { |
| return fmt.Errorf("Transport busy") |
| } |
| sx.rspSesn = s |
| return nil |
| } |
| |
| func (sx *SerialXport) setAcceptSesn(s *SerialSesn) error { |
| sx.Lock() |
| defer sx.Unlock() |
| |
| if sx.closing { |
| return fmt.Errorf("Transport closed") |
| } |
| if sx.acceptSesn != nil && s != sx.acceptSesn { |
| return fmt.Errorf("Transport busy") |
| } |
| sx.acceptSesn = s |
| return nil |
| } |
| |
| func (sx *SerialXport) setReqSesn(s *SerialSesn) error { |
| if sx.closing { |
| return fmt.Errorf("Transport closed") |
| } |
| if sx.reqSesn != nil && s != sx.reqSesn { |
| return fmt.Errorf("Transport busy") |
| } |
| sx.reqSesn = s |
| return nil |
| } |
| |
| func (sx *SerialXport) Stop() error { |
| sx.closing = true |
| |
| err := sx.port.Close() |
| sx.wg.Wait() |
| return err |
| } |
| |
| func (sx *SerialXport) txRaw(bytes []byte) error { |
| log.Debugf("Tx serial\n%s", hex.Dump(bytes)) |
| |
| _, err := sx.port.Write(bytes) |
| if err != nil { |
| return err |
| } |
| |
| return nil |
| } |
| |
| func (sx *SerialXport) Tx(bytes []byte) error { |
| log.Debugf("Base64 encoding request:\n%s", hex.Dump(bytes)) |
| |
| pktData := make([]byte, 2) |
| |
| crc := crc16.Crc16(bytes) |
| binary.BigEndian.PutUint16(pktData, crc) |
| bytes = append(bytes, pktData...) |
| |
| dLen := uint16(len(bytes)) |
| binary.BigEndian.PutUint16(pktData, dLen) |
| pktData = append(pktData, bytes...) |
| |
| base64Data := make([]byte, base64.StdEncoding.EncodedLen(len(pktData))) |
| |
| base64.StdEncoding.Encode(base64Data, pktData) |
| |
| written := 0 |
| totlen := len(base64Data) |
| |
| for written < totlen { |
| /* write the packet stat designators. They are |
| * different whether we are starting a new packet or continuing one */ |
| if written == 0 { |
| sx.txRaw([]byte{6, 9}) |
| } else { |
| /* slower platforms take some time to process each segment |
| * and have very small receive buffers. Give them a bit of |
| * time here */ |
| time.Sleep(20 * time.Millisecond) |
| sx.txRaw([]byte{4, 20}) |
| } |
| |
| /* ensure that the total frame fits into 128 bytes. |
| * base 64 is 3 ascii to 4 base 64 byte encoding. so |
| * the number below should be a multiple of 4. Also, |
| * we need to save room for the header (2 byte) and |
| * carriage return (and possibly LF 2 bytes), */ |
| |
| /* all totaled, 124 bytes should work */ |
| writeLen := util.Min(124, totlen-written) |
| |
| writeBytes := base64Data[written : written+writeLen] |
| sx.txRaw(writeBytes) |
| sx.txRaw([]byte{'\n'}) |
| |
| written += writeLen |
| } |
| |
| return nil |
| } |
| |
| // Blocking receive. |
| func (sx *SerialXport) Rx() ([]byte, error) { |
| for sx.scanner.Scan() { |
| line := []byte(sx.scanner.Text()) |
| |
| for { |
| if len(line) > 1 && line[0] == '\r' { |
| line = line[1:] |
| } else { |
| break |
| } |
| } |
| log.Debugf("Rx serial:\n%s", hex.Dump(line)) |
| if len(line) < 2 || ((line[0] != 4 || line[1] != 20) && |
| (line[0] != 6 || line[1] != 9)) { |
| continue |
| } |
| |
| base64Data := string(line[2:]) |
| |
| data, err := base64.StdEncoding.DecodeString(base64Data) |
| if err != nil { |
| return nil, fmt.Errorf("Couldn't decode base64 string:"+ |
| " %s\nPacket hex dump:\n%s", |
| base64Data, hex.Dump(line)) |
| } |
| |
| if line[0] == 6 && line[1] == 9 { |
| if len(data) < 2 { |
| continue |
| } |
| |
| pktLen := binary.BigEndian.Uint16(data[0:2]) |
| sx.pkt, err = NewPacket(pktLen) |
| if err != nil { |
| return nil, err |
| } |
| data = data[2:] |
| } |
| |
| if sx.pkt == nil { |
| continue |
| } |
| |
| full := sx.pkt.AddBytes(data) |
| if full { |
| if crc16.Crc16(sx.pkt.GetBytes()) != 0 { |
| return nil, fmt.Errorf("CRC error") |
| } |
| |
| /* |
| * Trim away the 2 bytes of CRC |
| */ |
| sx.pkt.TrimEnd(2) |
| b := sx.pkt.GetBytes() |
| sx.pkt = nil |
| |
| log.Debugf("Decoded input:\n%s", hex.Dump(b)) |
| return b, nil |
| } |
| } |
| |
| err := sx.scanner.Err() |
| if err == nil { |
| // Scanner hit EOF, so we'll need to create a new one. This only |
| // happens on timeouts. |
| err = errTimeout |
| sx.scanner = bufio.NewScanner(sx.port) |
| } |
| return nil, err |
| } |