| /** |
| * 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 nmcoap |
| |
| import ( |
| "fmt" |
| "strings" |
| "sync" |
| |
| "github.com/runtimeco/go-coap" |
| ) |
| |
| type MsgFilter func(msg coap.Message) (coap.Message, error) |
| |
| var messageIdMtx sync.Mutex |
| var nextMessageId uint16 |
| |
| func NextMessageId() uint16 { |
| messageIdMtx.Lock() |
| defer messageIdMtx.Unlock() |
| |
| id := nextMessageId |
| nextMessageId++ |
| return id |
| } |
| |
| func validateToken(t []byte) error { |
| if len(t) > 8 { |
| return fmt.Errorf("Invalid token; len=%d, must be <= 8", len(t)) |
| } |
| |
| return nil |
| } |
| |
| func buildMessage(isTcp bool, p coap.MessageParams) coap.Message { |
| if isTcp { |
| return coap.NewTcpMessage(p) |
| } else { |
| return coap.NewDgramMessage(p) |
| } |
| } |
| |
| func Encode(m coap.Message) ([]byte, error) { |
| b, err := m.MarshalBinary() |
| if err != nil { |
| return nil, fmt.Errorf("Failed to encode CoAP: %s\n", err.Error()) |
| } |
| |
| return b, nil |
| } |
| |
| func CreateGet(isTcp bool, resUri string, observe int, token []byte) (coap.Message, error) { |
| var q []string |
| |
| if err := validateToken(token); err != nil { |
| return nil, err |
| } |
| |
| p := coap.MessageParams{ |
| Type: coap.Confirmable, |
| Code: coap.GET, |
| Token: token, |
| } |
| |
| m := buildMessage(isTcp, p) |
| |
| q = strings.SplitN(resUri, "?", 2) |
| m.SetPathString(q[0]) |
| if len(q) > 1 { |
| m.SetURIQuery(q[1]) |
| } |
| |
| if observe >= 0 { |
| m.SetObserve(observe) |
| } |
| |
| return m, nil |
| } |
| |
| func CreatePut(isTcp bool, resUri string, token []byte, |
| val []byte) (coap.Message, error) { |
| |
| if err := validateToken(token); err != nil { |
| return nil, err |
| } |
| |
| p := coap.MessageParams{ |
| Type: coap.Confirmable, |
| Code: coap.PUT, |
| Token: token, |
| Payload: val, |
| } |
| |
| m := buildMessage(isTcp, p) |
| m.SetPathString(resUri) |
| |
| return m, nil |
| } |
| |
| func CreatePost(isTcp bool, resUri string, token []byte, |
| val []byte) (coap.Message, error) { |
| |
| if err := validateToken(token); err != nil { |
| return nil, err |
| } |
| |
| p := coap.MessageParams{ |
| Type: coap.Confirmable, |
| Code: coap.POST, |
| Token: token, |
| Payload: val, |
| } |
| |
| m := buildMessage(isTcp, p) |
| m.SetPathString(resUri) |
| |
| return m, nil |
| } |
| |
| func CreateDelete(isTcp bool, resUri string, token []byte, |
| val []byte) (coap.Message, error) { |
| |
| if err := validateToken(token); err != nil { |
| return nil, err |
| } |
| |
| p := coap.MessageParams{ |
| Type: coap.Confirmable, |
| Code: coap.DELETE, |
| Token: token, |
| Payload: val, |
| } |
| |
| m := buildMessage(isTcp, p) |
| m.SetPathString(resUri) |
| |
| return m, nil |
| } |