├── CONTRIBUTORS
├── LICENSE
├── README.md
├── doc.go
├── handlers.go
├── udp.go
├── udp_config.go
├── udp_handlers_test.go
└── udp_test.go


/CONTRIBUTORS:
--------------------------------------------------------------------------------
 1 | # This is the official list of people who can contribute
 2 | # (and typically have contributed) code to the gotraining repository.
 3 | #
 4 | # Names should be added to this file only after verifying that
 5 | # the individual or the individual's organization has agreed to
 6 | # the appropriate Contributor License Agreement, found here:
 7 | #
 8 | #     http://code.google.com/legal/individual-cla-v1.0.html
 9 | #     http://code.google.com/legal/corporate-cla-v1.0.html
10 | #
11 | # The agreement for individuals can be filled out on the web.
12 | 
13 | # Names should be added to this file like so:
14 | #     Name <email address>
15 | #
16 | # An entry with two email addresses specifies that the
17 | # first address should be used in the submit logs and
18 | # that the second address should be recognized as the
19 | # same person when interacting with Rietveld.
20 | 
21 | # Please keep the list sorted.
22 | 
23 | William Kennedy <bill@ardanlabs.com>


--------------------------------------------------------------------------------
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--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
  1 | 
  2 | 
  3 | # udp
  4 | `import "github.com/ardanlabs/udp"`
  5 | 
  6 | * [Overview](#pkg-overview)
  7 | * [Index](#pkg-index)
  8 | 
  9 | ## <a name="pkg-overview">Overview</a>
 10 | Package udp provides the boilerplate code for working with UDP based data. The package
 11 | allows you to establish a UDP listener that can accept data on a specified IP address
 12 | and port. It also provides a function to send data back to the client.
 13 | 
 14 | There are three interfaces that need to be implemented to use the package. These
 15 | interfaces provide the API for processing data.
 16 | 
 17 | ConnHandler
 18 | 
 19 | 
 20 | 	type ConnHandler interface {
 21 | 	    Bind(logCtx string, listener *net.UDPConn) (io.Reader, io.Writer)
 22 | 	}
 23 | 
 24 | The ConnHandler interface is implemented by the user to bind the listener
 25 | to a reader and writer for processing.
 26 | 
 27 | ReqHandler
 28 | 
 29 | 
 30 | 	type ReqHandler interface {
 31 | 	    Read(logCtx string, reader io.Reader) (*net.UDPAddr, []byte, int, error)
 32 | 	    Process(logCtx string, r *Request)
 33 | 	}
 34 | 	
 35 | 	type Request struct {
 36 | 	    UDP     *UDP
 37 | 	    UDPAddr *net.UDPAddr
 38 | 	    Data    []byte
 39 | 	    Length  int
 40 | 	}
 41 | 
 42 | The ReqHandler interface is implemented by the user to implement the processing
 43 | of request messages from the client. Read is provided the user-defined reader
 44 | and must return the data read off the wire and the length. Returning io.EOF or
 45 | a non temporary error will show down the listener.
 46 | 
 47 | RespHandler
 48 | 
 49 | 
 50 | 	type RespHandler interface {
 51 | 	    Write(logCtx string, r *Response, writer io.Writer)
 52 | 	}
 53 | 	
 54 | 	type Response struct {
 55 | 	    UDPAddr *net.UDPAddr
 56 | 	    Data    []byte
 57 | 	    Length  int
 58 | 	}
 59 | 
 60 | The RespHandler interface is implemented by the user to implement the processing
 61 | of the response messages to the client. Write is provided the user-defined
 62 | writer and the data to write.
 63 | 
 64 | ### Sample Application
 65 | After implementing the interfaces, the following code is all that is needed to
 66 | start processing messages.
 67 | 
 68 | 
 69 | 	func main() {
 70 | 	    log.Startf("TEST", "main", "Starting Test App")
 71 | 	
 72 | 	    cfg := udp.Config{
 73 | 	        NetType:      "udp4",
 74 | 	        Addr:         ":9000",
 75 | 	        WorkRoutines: 2,
 76 | 	        WorkStats:    time.Minute,
 77 | 	        ConnHandler:  udpConnHandler{},
 78 | 	        ReqHandler:   udpReqHandler{},
 79 | 	        RespHandler:  udpRespHandler{},
 80 | 	    }
 81 | 	
 82 | 	    u, err := udp.New("TEST", &cfg)
 83 | 	    if err != nil {
 84 | 	        log.ErrFatal(err, "TEST", "main")
 85 | 	    }
 86 | 	
 87 | 	    if err := u.Start("TEST"); err != nil {
 88 | 	        log.ErrFatal(err, "TEST", "main")
 89 | 	    }
 90 | 	
 91 | 	    // Wait for a signal to shutdown.
 92 | 	    sigChan := make(chan os.Signal, 1)
 93 | 	    signal.Notify(sigChan, os.Interrupt)
 94 | 	    <-sigChan
 95 | 	
 96 | 	    u.Stop("TEST")
 97 | 	
 98 | 	    log.Complete("TEST", "main")
 99 | 	}
100 | 
101 | 
102 | 
103 | 
104 | ## <a name="pkg-index">Index</a>
105 | * [Variables](#pkg-variables)
106 | * [type Config](#Config)
107 |   * [func (cfg *Config) Event(event string, format string, a ...interface{})](#Config.Event)
108 |   * [func (cfg *Config) Validate() error](#Config.Validate)
109 | * [type ConnHandler](#ConnHandler)
110 | * [type OptEvent](#OptEvent)
111 | * [type ReqHandler](#ReqHandler)
112 | * [type Request](#Request)
113 | * [type RespHandler](#RespHandler)
114 | * [type Response](#Response)
115 | * [type UDP](#UDP)
116 |   * [func New(name string, cfg Config) (*UDP, error)](#New)
117 |   * [func (d *UDP) Addr() net.Addr](#UDP.Addr)
118 |   * [func (d *UDP) Send(r *Response) error](#UDP.Send)
119 |   * [func (d *UDP) Start() error](#UDP.Start)
120 |   * [func (d *UDP) Stop() error](#UDP.Stop)
121 | 
122 | 
123 | #### <a name="pkg-files">Package files</a>
124 | [doc.go](/src/github.com/ardanlabs/udp/doc.go) [handlers.go](/src/github.com/ardanlabs/udp/handlers.go) [udp.go](/src/github.com/ardanlabs/udp/udp.go) [udp_config.go](/src/github.com/ardanlabs/udp/udp_config.go) 
125 | 
126 | 
127 | 
128 | ## <a name="pkg-variables">Variables</a>
129 | ``` go
130 | var (
131 |     ErrInvalidConfiguration = errors.New("Invalid Configuration")
132 |     ErrInvalidNetType       = errors.New("Invalid NetType Configuration")
133 |     ErrInvalidConnHandler   = errors.New("Invalid Connection Handler Configuration")
134 |     ErrInvalidReqHandler    = errors.New("Invalid Request Handler Configuration")
135 |     ErrInvalidRespHandler   = errors.New("Invalid Response Handler Configuration")
136 | )
137 | ```
138 | Set of error variables for start up.
139 | 
140 | 
141 | 
142 | 
143 | ## <a name="Config">type</a> [Config](/src/target/udp_config.go?s=227:845#L1)
144 | ``` go
145 | type Config struct {
146 |     NetType string // "udp", udp4" or "udp6"
147 |     Addr    string // "host:port" or "[ipv6-host%zone]:port"
148 | 
149 |     ConnHandler ConnHandler // Support for binding new connections to a reader and writer.
150 |     ReqHandler  ReqHandler  // Support for handling the specific request workflow.
151 |     RespHandler RespHandler // Support for handling the specific response workflow.
152 | 
153 |     OptEvent
154 | }
155 | ```
156 | Config provides a data structure of required configuration parameters.
157 | 
158 | 
159 | 
160 | 
161 | 
162 | 
163 | 
164 | 
165 | 
166 | 
167 | ### <a name="Config.Event">func</a> (\*Config) [Event](/src/target/udp_config.go?s=1369:1440#L40)
168 | ``` go
169 | func (cfg *Config) Event(event string, format string, a ...interface{})
170 | ```
171 | Event fires events back to the user for important events.
172 | 
173 | 
174 | 
175 | 
176 | ### <a name="Config.Validate">func</a> (\*Config) [Validate](/src/target/udp_config.go?s=903:938#L15)
177 | ``` go
178 | func (cfg *Config) Validate() error
179 | ```
180 | Validate checks the configuration to required items.
181 | 
182 | 
183 | 
184 | 
185 | ## <a name="ConnHandler">type</a> [ConnHandler](/src/target/handlers.go?s=447:579#L18)
186 | ``` go
187 | type ConnHandler interface {
188 | 
189 |     // Bind is called to set the reader and writer.
190 |     Bind(listener *net.UDPConn) (io.Reader, io.Writer)
191 | }
192 | ```
193 | ConnHandler is implemented by the user to bind the listener
194 | to a reader and writer for processing.
195 | 
196 | 
197 | 
198 | 
199 | 
200 | 
201 | 
202 | 
203 | 
204 | 
205 | ## <a name="OptEvent">type</a> [OptEvent](/src/target/udp_config.go?s=68:151#L1)
206 | ``` go
207 | type OptEvent struct {
208 |     Event func(event string, format string, a ...interface{})
209 | }
210 | ```
211 | OptEvent defines an handler used to provide events.
212 | 
213 | 
214 | 
215 | 
216 | 
217 | 
218 | 
219 | 
220 | 
221 | 
222 | ## <a name="ReqHandler">type</a> [ReqHandler](/src/target/handlers.go?s=690:1109#L26)
223 | ``` go
224 | type ReqHandler interface {
225 | 
226 |     // Read is provided the user-defined reader and must return the data read
227 |     // off the wire and the length. Returning io.EOF or a non temporary error
228 |     // will show down the listener.
229 |     Read(reader io.Reader) (*net.UDPAddr, []byte, int, error)
230 | 
231 |     // Process is used to handle the processing of the request. This method
232 |     // is called on a routine from a pool of routines.
233 |     Process(r *Request)
234 | }
235 | ```
236 | ReqHandler is implemented by the user to implement the processing
237 | of request messages from the client.
238 | 
239 | 
240 | 
241 | 
242 | 
243 | 
244 | 
245 | 
246 | 
247 | 
248 | ## <a name="Request">type</a> [Request](/src/target/handlers.go?s=96:217#L1)
249 | ``` go
250 | type Request struct {
251 |     UDP     *UDP
252 |     UDPAddr *net.UDPAddr
253 |     IsIPv6  bool
254 |     ReadAt  time.Time
255 |     Data    []byte
256 |     Length  int
257 | }
258 | ```
259 | Request is the message received by the client.
260 | 
261 | 
262 | 
263 | 
264 | 
265 | 
266 | 
267 | 
268 | 
269 | 
270 | ## <a name="RespHandler">type</a> [RespHandler](/src/target/handlers.go?s=1224:1368#L40)
271 | ``` go
272 | type RespHandler interface {
273 | 
274 |     // Write is provided the user-defined writer and the data to write.
275 |     Write(r *Response, writer io.Writer) error
276 | }
277 | ```
278 | RespHandler is implemented by the user to implement the processing
279 | of the response messages to the client.
280 | 
281 | 
282 | 
283 | 
284 | 
285 | 
286 | 
287 | 
288 | 
289 | 
290 | ## <a name="Response">type</a> [Response](/src/target/handlers.go?s=265:340#L10)
291 | ``` go
292 | type Response struct {
293 |     UDPAddr *net.UDPAddr
294 |     Data    []byte
295 |     Length  int
296 | }
297 | ```
298 | Response is message to send to the client.
299 | 
300 | 
301 | 
302 | 
303 | 
304 | 
305 | 
306 | 
307 | 
308 | 
309 | ## <a name="UDP">type</a> [UDP](/src/target/udp.go?s=717:953#L19)
310 | ``` go
311 | type UDP struct {
312 |     Config
313 |     Name string
314 |     // contains filtered or unexported fields
315 | }
316 | ```
317 | UDP manages message to a specific ip address and port.
318 | 
319 | 
320 | 
321 | 
322 | 
323 | 
324 | 
325 | ### <a name="New">func</a> [New](/src/target/udp.go?s=1004:1051#L38)
326 | ``` go
327 | func New(name string, cfg Config) (*UDP, error)
328 | ```
329 | New creates a new manager to service clients.
330 | 
331 | 
332 | 
333 | 
334 | 
335 | ### <a name="UDP.Addr">func</a> (\*UDP) [Addr](/src/target/udp.go?s=4944:4973#L216)
336 | ``` go
337 | func (d *UDP) Addr() net.Addr
338 | ```
339 | Addr returns the local listening network address.
340 | 
341 | 
342 | 
343 | 
344 | ### <a name="UDP.Send">func</a> (\*UDP) [Send](/src/target/udp.go?s=4807:4844#L211)
345 | ``` go
346 | func (d *UDP) Send(r *Response) error
347 | ```
348 | Send will deliver the response back to the client.
349 | 
350 | 
351 | 
352 | 
353 | ### <a name="UDP.Start">func</a> (\*UDP) [Start](/src/target/udp.go?s=1675:1702#L70)
354 | ``` go
355 | func (d *UDP) Start() error
356 | ```
357 | Start begins to accept data.
358 | 
359 | 
360 | 
361 | 
362 | ### <a name="UDP.Stop">func</a> (\*UDP) [Stop](/src/target/udp.go?s=4236:4262#L183)
363 | ``` go
364 | func (d *UDP) Stop() error
365 | ```
366 | Stop shuts down the manager and closes all connections.
367 | 
368 | 
369 | 
370 | 
371 | 
372 | 
373 | 
374 | 
375 | - - -
376 | Generated by [godoc2md](http://godoc.org/github.com/davecheney/godoc2md)
377 | 


--------------------------------------------------------------------------------
/doc.go:
--------------------------------------------------------------------------------
 1 | // Package udp provides the boilerplate code for working with UDP based data. The package
 2 | // allows you to establish a UDP listener that can accept data on a specified IP address
 3 | // and port. It also provides a function to send data back to the client.
 4 | //
 5 | // There are three interfaces that need to be implemented to use the package. These
 6 | // interfaces provide the API for processing data.
 7 | //
 8 | // ConnHandler
 9 | //
10 | //     type ConnHandler interface {
11 | //         Bind(logCtx string, listener *net.UDPConn) (io.Reader, io.Writer)
12 | //     }
13 | //
14 | // The ConnHandler interface is implemented by the user to bind the listener
15 | // to a reader and writer for processing.
16 | //
17 | // ReqHandler
18 | //
19 | //     type ReqHandler interface {
20 | //         Read(logCtx string, reader io.Reader) (*net.UDPAddr, []byte, int, error)
21 | //         Process(logCtx string, r *Request)
22 | //     }
23 | //
24 | //     type Request struct {
25 | //         UDP     *UDP
26 | //         UDPAddr *net.UDPAddr
27 | //         Data    []byte
28 | //         Length  int
29 | //     }
30 | //
31 | // The ReqHandler interface is implemented by the user to implement the processing
32 | // of request messages from the client. Read is provided the user-defined reader
33 | // and must return the data read off the wire and the length. Returning io.EOF or
34 | // a non temporary error will show down the listener.
35 | //
36 | // RespHandler
37 | //
38 | //     type RespHandler interface {
39 | //         Write(logCtx string, r *Response, writer io.Writer)
40 | //     }
41 | //
42 | //     type Response struct {
43 | //         UDPAddr *net.UDPAddr
44 | //         Data    []byte
45 | //         Length  int
46 | //     }
47 | //
48 | // The RespHandler interface is implemented by the user to implement the processing
49 | // of the response messages to the client. Write is provided the user-defined
50 | // writer and the data to write.
51 | //
52 | // Sample Application
53 | //
54 | // After implementing the interfaces, the following code is all that is needed to
55 | // start processing messages.
56 | //
57 | //     func main() {
58 | //         log.Startf("TEST", "main", "Starting Test App")
59 | //
60 | //         cfg := udp.Config{
61 | //             NetType:      "udp4",
62 | //             Addr:         ":9000",
63 | //             WorkRoutines: 2,
64 | //             WorkStats:    time.Minute,
65 | //             ConnHandler:  udpConnHandler{},
66 | //             ReqHandler:   udpReqHandler{},
67 | //             RespHandler:  udpRespHandler{},
68 | //         }
69 | //
70 | //         u, err := udp.New("TEST", &cfg)
71 | //         if err != nil {
72 | //             log.ErrFatal(err, "TEST", "main")
73 | //         }
74 | //
75 | //         if err := u.Start("TEST"); err != nil {
76 | //             log.ErrFatal(err, "TEST", "main")
77 | //         }
78 | //
79 | //         // Wait for a signal to shutdown.
80 | //         sigChan := make(chan os.Signal, 1)
81 | //         signal.Notify(sigChan, os.Interrupt)
82 | //         <-sigChan
83 | //
84 | //         u.Stop("TEST")
85 | //
86 | //         log.Complete("TEST", "main")
87 | //     }
88 | package udp
89 | 


--------------------------------------------------------------------------------
/handlers.go:
--------------------------------------------------------------------------------
 1 | package udp
 2 | 
 3 | import (
 4 | 	"io"
 5 | 	"net"
 6 | 	"time"
 7 | )
 8 | 
 9 | // Request is the message received by the client.
10 | type Request struct {
11 | 	UDP     *UDP
12 | 	UDPAddr *net.UDPAddr
13 | 	IsIPv6  bool
14 | 	ReadAt  time.Time
15 | 	Data    []byte
16 | 	Length  int
17 | }
18 | 
19 | // Response is message to send to the client.
20 | type Response struct {
21 | 	UDPAddr *net.UDPAddr
22 | 	Data    []byte
23 | 	Length  int
24 | }
25 | 
26 | // ConnHandler is implemented by the user to bind the listener
27 | // to a reader and writer for processing.
28 | type ConnHandler interface {
29 | 
30 | 	// Bind is called to set the reader and writer.
31 | 	Bind(listener *net.UDPConn) (io.Reader, io.Writer)
32 | }
33 | 
34 | // ReqHandler is implemented by the user to implement the processing
35 | // of request messages from the client.
36 | type ReqHandler interface {
37 | 
38 | 	// Read is provided the user-defined reader and must return the data read
39 | 	// off the wire and the length. Returning io.EOF or a non temporary error
40 | 	// will show down the listener.
41 | 	Read(reader io.Reader) (*net.UDPAddr, []byte, int, error)
42 | 
43 | 	// Process is used to handle the processing of the request. This method
44 | 	// is called on a routine from a pool of routines.
45 | 	Process(r *Request)
46 | }
47 | 
48 | // RespHandler is implemented by the user to implement the processing
49 | // of the response messages to the client.
50 | type RespHandler interface {
51 | 
52 | 	// Write is provided the user-defined writer and the data to write.
53 | 	Write(r *Response, writer io.Writer) error
54 | }
55 | 


--------------------------------------------------------------------------------
/udp.go:
--------------------------------------------------------------------------------
  1 | package udp
  2 | 
  3 | import (
  4 | 	"errors"
  5 | 	"io"
  6 | 	"net"
  7 | 	"strconv"
  8 | 	"sync"
  9 | 	"sync/atomic"
 10 | 	"time"
 11 | )
 12 | 
 13 | // Set of error variables for start up.
 14 | var (
 15 | 	ErrInvalidConfiguration = errors.New("Invalid Configuration")
 16 | 	ErrInvalidNetType       = errors.New("Invalid NetType Configuration")
 17 | 	ErrInvalidConnHandler   = errors.New("Invalid Connection Handler Configuration")
 18 | 	ErrInvalidReqHandler    = errors.New("Invalid Request Handler Configuration")
 19 | 	ErrInvalidRespHandler   = errors.New("Invalid Response Handler Configuration")
 20 | )
 21 | 
 22 | // temporary is declared to test for the existence of the method coming
 23 | // from the net package.
 24 | type temporary interface {
 25 | 	Temporary() bool
 26 | }
 27 | 
 28 | // UDP manages message to a specific ip address and port.
 29 | type UDP struct {
 30 | 	Config
 31 | 	Name string
 32 | 
 33 | 	ipAddress string
 34 | 	port      int
 35 | 	udpAddr   *net.UDPAddr
 36 | 
 37 | 	listener   *net.UDPConn
 38 | 	listenerMu sync.RWMutex
 39 | 
 40 | 	reader io.Reader
 41 | 	writer io.Writer
 42 | 
 43 | 	wg           sync.WaitGroup
 44 | 	shuttingDown int32
 45 | }
 46 | 
 47 | // New creates a new manager to service clients.
 48 | func New(name string, cfg Config) (*UDP, error) {
 49 | 
 50 | 	// Validate the configuration.
 51 | 	if err := cfg.Validate(); err != nil {
 52 | 		return nil, err
 53 | 	}
 54 | 
 55 | 	// Resolve the addr that is provided.
 56 | 	udpAddr, err := net.ResolveUDPAddr(cfg.NetType, cfg.Addr)
 57 | 	if err != nil {
 58 | 		return nil, err
 59 | 	}
 60 | 
 61 | 	// Create a UDP for this ipaddress and port.
 62 | 	udp := UDP{
 63 | 		Config: cfg,
 64 | 		Name:   name,
 65 | 
 66 | 		ipAddress: udpAddr.IP.String(),
 67 | 		port:      udpAddr.Port,
 68 | 		udpAddr:   udpAddr,
 69 | 	}
 70 | 
 71 | 	return &udp, nil
 72 | }
 73 | 
 74 | // join takes an IP and port values and creates a cleaner string.
 75 | func join(ip string, port int) string {
 76 | 	return net.JoinHostPort(ip, strconv.Itoa(port))
 77 | }
 78 | 
 79 | // Start begins to accept data.
 80 | func (d *UDP) Start() error {
 81 | 	d.listenerMu.Lock()
 82 | 	{
 83 | 		// If the listener has been started already, return an error.
 84 | 		if d.listener != nil {
 85 | 			d.listenerMu.Unlock()
 86 | 			return errors.New("this UDP has already been started")
 87 | 		}
 88 | 	}
 89 | 	d.listenerMu.Unlock()
 90 | 
 91 | 	// We need to wait for the goroutine to initialize itself.
 92 | 	var waitStart sync.WaitGroup
 93 | 	waitStart.Add(1)
 94 | 
 95 | 	// Start the data accept routine.
 96 | 	d.wg.Add(1)
 97 | 	go func() {
 98 | 		for {
 99 | 			d.listenerMu.Lock()
100 | 			{
101 | 				// Start a listener for the specified addr and port is one
102 | 				// does not exist.
103 | 				if d.listener == nil {
104 | 					var err error
105 | 					d.listener, err = net.ListenUDP(d.NetType, d.udpAddr)
106 | 					if err != nil {
107 | 						panic(err)
108 | 					}
109 | 
110 | 					// Ask the user to bind the reader and writer they want to
111 | 					// use for this listener.
112 | 					d.reader, d.writer = d.ConnHandler.Bind(d.listener)
113 | 
114 | 					waitStart.Done()
115 | 
116 | 					d.Event("accept", "Waiting For Data : IPAddress[ %s ]", join(d.ipAddress, d.port))
117 | 				}
118 | 			}
119 | 			d.listenerMu.Unlock()
120 | 
121 | 			// Wait for a message to arrive.
122 | 			udpAddr, data, length, err := d.ReqHandler.Read(d.reader)
123 | 			timeRead := time.Now()
124 | 
125 | 			if err != nil {
126 | 				if atomic.LoadInt32(&d.shuttingDown) == 1 {
127 | 					d.listenerMu.Lock()
128 | 					{
129 | 						d.listener = nil
130 | 					}
131 | 					d.listenerMu.Unlock()
132 | 					break
133 | 				}
134 | 
135 | 				d.Event("accept", "ERROR : %v", err)
136 | 
137 | 				if e, ok := err.(temporary); ok && !e.Temporary() {
138 | 					d.listenerMu.Lock()
139 | 					{
140 | 						d.listener.Close()
141 | 						d.listener = nil
142 | 					}
143 | 					d.listenerMu.Unlock()
144 | 
145 | 					// Don't want to add a flag. So setting this back to
146 | 					// 1 so when the listener is re-established, the call
147 | 					// to Done does not fail.
148 | 					waitStart.Add(1)
149 | 				}
150 | 
151 | 				continue
152 | 			}
153 | 
154 | 			// Check to see if this message is ipv6.
155 | 			isIPv6 := true
156 | 			if ip4 := udpAddr.IP.To4(); ip4 != nil {
157 | 
158 | 				// Make sure we return an IPv4 address if udpAddr
159 | 				// is an IPv4-mapped IPv6 address.  Otherwise we
160 | 				// could end up sending an IPv6 response.
161 | 				udpAddr.IP = ip4
162 | 				isIPv6 = false
163 | 			}
164 | 
165 | 			// Create the request.
166 | 			req := Request{
167 | 				UDP:     d,
168 | 				UDPAddr: udpAddr,
169 | 				IsIPv6:  isIPv6,
170 | 				ReadAt:  timeRead,
171 | 				Data:    data,
172 | 				Length:  length,
173 | 			}
174 | 
175 | 			// Process the request on this goroutine that is
176 | 			// handling the socket connection.
177 | 			d.ReqHandler.Process(&req)
178 | 		}
179 | 
180 | 		d.wg.Done()
181 | 		d.Event("accept", "Shutdown : IPAddress[ %s ]", join(d.ipAddress, d.port))
182 | 
183 | 		return
184 | 	}()
185 | 
186 | 	// Wait for the goroutine to initialize itself.
187 | 	waitStart.Wait()
188 | 
189 | 	return nil
190 | }
191 | 
192 | // Stop shuts down the manager and closes all connections.
193 | func (d *UDP) Stop() error {
194 | 	d.listenerMu.Lock()
195 | 	{
196 | 		// If the listener has been stopped already, return an error.
197 | 		if d.listener == nil {
198 | 			d.listenerMu.Unlock()
199 | 			return errors.New("this UDP has already been stopped")
200 | 		}
201 | 	}
202 | 	d.listenerMu.Unlock()
203 | 
204 | 	// Mark that we are shutting down.
205 | 	atomic.StoreInt32(&d.shuttingDown, 1)
206 | 
207 | 	// Don't accept anymore client data.
208 | 	d.listenerMu.Lock()
209 | 	{
210 | 		d.listener.Close()
211 | 	}
212 | 	d.listenerMu.Unlock()
213 | 
214 | 	// Wait for the accept routine to terminate.
215 | 	d.wg.Wait()
216 | 
217 | 	return nil
218 | }
219 | 
220 | // Send will deliver the response back to the client.
221 | func (d *UDP) Send(r *Response) error {
222 | 	return d.RespHandler.Write(r, d.writer)
223 | }
224 | 
225 | // Addr returns the local listening network address.
226 | func (d *UDP) Addr() net.Addr {
227 | 
228 | 	// We are aware this read is not safe with the
229 | 	// goroutine accepting connections.
230 | 	if d.listener == nil {
231 | 		return nil
232 | 	}
233 | 	return d.listener.LocalAddr()
234 | }
235 | 


--------------------------------------------------------------------------------
/udp_config.go:
--------------------------------------------------------------------------------
 1 | package udp
 2 | 
 3 | // OptEvent defines an handler used to provide events.
 4 | type OptEvent struct {
 5 | 	Event func(event string, format string, a ...interface{})
 6 | }
 7 | 
 8 | // Config provides a data structure of required configuration parameters.
 9 | type Config struct {
10 | 	NetType string // "udp", udp4" or "udp6"
11 | 	Addr    string // "host:port" or "[ipv6-host%zone]:port"
12 | 
13 | 	ConnHandler ConnHandler // Support for binding new connections to a reader and writer.
14 | 	ReqHandler  ReqHandler  // Support for handling the specific request workflow.
15 | 	RespHandler RespHandler // Support for handling the specific response workflow.
16 | 
17 | 	// *************************************************************************
18 | 	// ** Not Required, optional                                              **
19 | 	// *************************************************************************
20 | 
21 | 	OptEvent
22 | }
23 | 
24 | // Validate checks the configuration to required items.
25 | func (cfg *Config) Validate() error {
26 | 	if cfg == nil {
27 | 		return ErrInvalidConfiguration
28 | 	}
29 | 
30 | 	if cfg.NetType != "udp" && cfg.NetType != "udp4" && cfg.NetType != "udp6" {
31 | 		return ErrInvalidNetType
32 | 	}
33 | 
34 | 	if cfg.ConnHandler == nil {
35 | 		return ErrInvalidConnHandler
36 | 	}
37 | 
38 | 	if cfg.ReqHandler == nil {
39 | 		return ErrInvalidReqHandler
40 | 	}
41 | 
42 | 	if cfg.RespHandler == nil {
43 | 		return ErrInvalidRespHandler
44 | 	}
45 | 
46 | 	return nil
47 | }
48 | 
49 | // Event fires events back to the user for important events.
50 | func (cfg *Config) Event(event string, format string, a ...interface{}) {
51 | 	if cfg.OptEvent.Event != nil {
52 | 		cfg.OptEvent.Event(event, format, a...)
53 | 	}
54 | }
55 | 


--------------------------------------------------------------------------------
/udp_handlers_test.go:
--------------------------------------------------------------------------------
 1 | package udp_test
 2 | 
 3 | import (
 4 | 	"io"
 5 | 	"net"
 6 | 	"sync/atomic"
 7 | 	"time"
 8 | 
 9 | 	"github.com/ardanlabs/udp"
10 | )
11 | 
12 | // udpConnHandler is required to process data.
13 | type udpConnHandler struct{}
14 | 
15 | // Bind is called to init to reader and writer.
16 | func (udpConnHandler) Bind(listener *net.UDPConn) (io.Reader, io.Writer) {
17 | 	return listener, listener
18 | }
19 | 
20 | // udpReqHandler is required to process client messages.
21 | type udpReqHandler struct{}
22 | 
23 | // Read implements the udp.ReqHandler interface. It is provided a request
24 | // value to popular and a io.Reader that was created in the Bind above.
25 | func (udpReqHandler) Read(reader io.Reader) (*net.UDPAddr, []byte, int, error) {
26 | 	listener := reader.(*net.UDPConn)
27 | 
28 | 	// Each package is 20 bytes in lengrh.
29 | 	data := make([]byte, 20)
30 | 	length, udpAddr, err := listener.ReadFromUDP(data)
31 | 	if err != nil {
32 | 		return nil, nil, 0, err
33 | 	}
34 | 
35 | 	return udpAddr, data, length, nil
36 | }
37 | 
38 | var dur int64
39 | 
40 | // Process is used to handle the processing of the message. This method
41 | // is called on a routine from a pool of routines.
42 | func (udpReqHandler) Process(r *udp.Request) {
43 | 	if r.Length != 20 {
44 | 		return
45 | 	}
46 | 
47 | 	// Extract the header from the first 8 bytes.
48 | 	// h := struct {
49 | 	// 	Raw           []byte
50 | 	// 	Length        int
51 | 	// 	Version       uint8
52 | 	// 	TransactionID uint8
53 | 	// 	OpCode        uint8
54 | 	// 	StatusCode    uint8
55 | 	// 	StreamHandle  uint32
56 | 	// }{
57 | 	// 	Raw:           r.Data,
58 | 	// 	Length:        r.Length,
59 | 	// 	Version:       uint8(r.Data[0]),
60 | 	// 	TransactionID: uint8(r.Data[1]),
61 | 	// 	OpCode:        uint8(r.Data[2]),
62 | 	// 	StatusCode:    uint8(r.Data[3]),
63 | 	// 	StreamHandle:  uint32(binary.BigEndian.Uint32(r.Data[4:8])),
64 | 	// }
65 | 
66 | 	resp := udp.Response{
67 | 		UDPAddr: r.UDPAddr,
68 | 		Data:    []byte("GOT IT"),
69 | 		Length:  6,
70 | 	}
71 | 
72 | 	r.UDP.Send(&resp)
73 | 
74 | 	d := int64(time.Now().Sub(r.ReadAt))
75 | 	atomic.StoreInt64(&dur, d)
76 | }
77 | 
78 | type udpRespHandler struct{}
79 | 
80 | // Write is provided the user-defined writer and the data to write.
81 | func (udpRespHandler) Write(r *udp.Response, writer io.Writer) error {
82 | 	listener := writer.(*net.UDPConn)
83 | 	if _, err := listener.WriteToUDP(r.Data, r.UDPAddr); err != nil {
84 | 		return err
85 | 	}
86 | 
87 | 	return nil
88 | }
89 | 


--------------------------------------------------------------------------------
/udp_test.go:
--------------------------------------------------------------------------------
  1 | package udp_test
  2 | 
  3 | import (
  4 | 	"bytes"
  5 | 	"io"
  6 | 	"net"
  7 | 	"os"
  8 | 	"sync/atomic"
  9 | 	"testing"
 10 | 	"time"
 11 | 
 12 | 	"github.com/ardanlabs/udp"
 13 | )
 14 | 
 15 | // TestUDP provide a test of listening for a connection and
 16 | // echoing the data back.
 17 | func TestUDP(t *testing.T) {
 18 | 	resetLog()
 19 | 	defer displayLog()
 20 | 
 21 | 	t.Log("Given the need to listen and process UDP data.")
 22 | 	{
 23 | 		// Create a configuration.
 24 | 		cfg := udp.Config{
 25 | 			NetType: "udp4",
 26 | 			Addr:    ":0",
 27 | 
 28 | 			ConnHandler: udpConnHandler{},
 29 | 			ReqHandler:  udpReqHandler{},
 30 | 			RespHandler: udpRespHandler{},
 31 | 		}
 32 | 
 33 | 		// Create a new UDP value.
 34 | 		u, err := udp.New("TEST", cfg)
 35 | 		if err != nil {
 36 | 			t.Fatal("\tShould be able to create a new UDP listener.", failed, err)
 37 | 		}
 38 | 		t.Log("\tShould be able to create a new UDP listener.", success)
 39 | 
 40 | 		// Start accepting client data.
 41 | 		if err := u.Start(); err != nil {
 42 | 			t.Fatal("\tShould be able to start the UDP listener.", failed, err)
 43 | 		}
 44 | 		t.Log("\tShould be able to start the UDP listener.", success)
 45 | 
 46 | 		defer u.Stop()
 47 | 
 48 | 		// Let's connect back and send a UDP package
 49 | 		conn, err := net.Dial("udp4", u.Addr().String())
 50 | 		if err != nil {
 51 | 			t.Fatal("\tShould be able to dial a new UDP connection.", failed, err)
 52 | 		}
 53 | 		t.Log("\tShould be able to dial a new UDP connection.", success)
 54 | 
 55 | 		// Send some know data to the udp listener.
 56 | 		b := bytes.NewBuffer([]byte{0x01, 0x3D, 0x06, 0x00, 0x58, 0x68, 0x9b, 0x9d, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFC, 0x00, 0x01})
 57 | 		b.WriteTo(conn)
 58 | 
 59 | 		// Setup a limit reader to extract the response.
 60 | 		lr := io.LimitReader(conn, 6)
 61 | 
 62 | 		// Let's read the response.
 63 | 		data := make([]byte, 6)
 64 | 		if _, err := lr.Read(data); err != nil {
 65 | 			t.Fatal("\tShould be able to read the response from the connection.", failed, err)
 66 | 		}
 67 | 		t.Log("\tShould be able to read the response from the connection.", success)
 68 | 
 69 | 		response := string(data)
 70 | 
 71 | 		if response == "GOT IT" {
 72 | 			t.Log("\tShould receive the string \"GOT IT\".", success)
 73 | 		} else {
 74 | 			t.Error("\tShould receive the string \"GOT IT\".", failed, response)
 75 | 		}
 76 | 
 77 | 		d := atomic.LoadInt64(&dur)
 78 | 		duration := time.Duration(d)
 79 | 
 80 | 		if duration <= 2*time.Second {
 81 | 			t.Log("\tShould be less that 2 seconds.", success)
 82 | 		} else {
 83 | 			t.Error("\tShould be less that 2 seconds.", failed, duration)
 84 | 		}
 85 | 	}
 86 | }
 87 | 
 88 | // Test udp.Addr works correctly.
 89 | func TestUDPAddr(t *testing.T) {
 90 | 	resetLog()
 91 | 	defer displayLog()
 92 | 
 93 | 	t.Log("Given the need to listen on any port and know that bound UDP address.")
 94 | 	{
 95 | 		// Create a configuration.
 96 | 		cfg := udp.Config{
 97 | 			NetType: "udp4",
 98 | 			Addr:    ":0", // Defer port assignment to OS.
 99 | 
100 | 			ConnHandler: udpConnHandler{},
101 | 			ReqHandler:  udpReqHandler{},
102 | 			RespHandler: udpRespHandler{},
103 | 		}
104 | 
105 | 		// Create a new UDP value.
106 | 		u, err := udp.New("TEST", cfg)
107 | 		if err != nil {
108 | 			t.Fatal("\tShould be able to create a new UDP listener.", failed, err)
109 | 		}
110 | 		t.Log("\tShould be able to create a new UDP listener.", success)
111 | 
112 | 		// Addr should be nil before start.
113 | 		if addr := u.Addr(); addr != nil {
114 | 			t.Fatalf("\tAddr() should be nil before Start; Addr() = %q. %s", addr, failed)
115 | 		}
116 | 		t.Log("\tAddr() should be nil before Start.", success)
117 | 
118 | 		// Start accepting client data.
119 | 		if err := u.Start(); err != nil {
120 | 			t.Fatal("\tShould be able to start the UDP listener.", failed, err)
121 | 		}
122 | 		defer u.Stop()
123 | 
124 | 		// Addr should be non-nil after Start.
125 | 		addr := u.Addr()
126 | 		if addr == nil {
127 | 			t.Fatal("\tAddr() should be not be nil after Start.", failed)
128 | 		}
129 | 		t.Log("\tAddr() should be not be nil after Start.", success)
130 | 
131 | 		// The OS should assign a random open port, which shouldn't be 0.
132 | 		_, port, err := net.SplitHostPort(addr.String())
133 | 		if err != nil {
134 | 			t.Fatalf("\tSplitHostPort should not fail. failed %v. %s", err, failed)
135 | 		}
136 | 		if port == "0" {
137 | 			t.Fatalf("\tAddr port should not be %q. %s", port, failed)
138 | 		}
139 | 		t.Logf("\tAddr() should be not be 0 after Start (port = %q). %s", port, success)
140 | 	}
141 | }
142 | 
143 | // Test generic UDP write timeout.
144 | func TestUDPWriteTimeout(t *testing.T) {
145 | 	t.Log("Given the need to get a timeout error on UDP write.")
146 | 	{
147 | 		localAddr, err := net.ResolveUDPAddr("udp4", "127.0.0.1:0")
148 | 		if err != nil {
149 | 			t.Fatalf("Should not have failed to resolve UDP address. Err[%v] %s", err, failed)
150 | 		}
151 | 		remoteAddr, err := net.ResolveUDPAddr("udp4", "127.0.0.1:1234")
152 | 		if err != nil {
153 | 			t.Fatalf("Should not have failed to resolve UDP address. Err[%v] %s", err, failed)
154 | 		}
155 | 
156 | 		conn, err := net.ListenUDP("udp4", localAddr)
157 | 		if err != nil {
158 | 			t.Fatalf("Should not have failed to create UDP connection. Err[%v] %s", err, failed)
159 | 		}
160 | 
161 | 		if err := conn.SetWriteDeadline(time.Now().Add(1)); err != nil {
162 | 			t.Fatalf("Should not have failed to set write deadline. Err[%v] %s", err, failed)
163 | 		}
164 | 
165 | 		const str = "String to send via UDP socket for testing purposes."
166 | 
167 | 		_, err = conn.WriteToUDP([]byte(str), remoteAddr)
168 | 		if err == nil {
169 | 			t.Fatalf("Should not gotten an error %s", failed)
170 | 		}
171 | 
172 | 		t.Logf("Got error [%T: %v] %s", err, err, success)
173 | 
174 | 		opError, ok := err.(*net.OpError)
175 | 		if !ok {
176 | 			t.Fatalf("Should have gotten *net.OpError, got [%T: %v] %s", err, err, failed)
177 | 		}
178 | 
179 | 		if !opError.Timeout() {
180 | 			t.Fatalf("Should have gotten a timeout error %s", failed)
181 | 		}
182 | 
183 | 		t.Logf("Got timeout error %s", success)
184 | 	}
185 | }
186 | 
187 | // =============================================================================
188 | 
189 | // Success and failure markers.
190 | var (
191 | 	success = "\u2713"
192 | 	failed  = "\u2717"
193 | )
194 | 
195 | // logdash is the central buffer where all logs are stored.
196 | var logdash bytes.Buffer
197 | 
198 | // resetLog resets the contents of Logdash.
199 | func resetLog() {
200 | 	logdash.Reset()
201 | }
202 | 
203 | // displayLog writes the Logdash data to standand out, if testing in verbose mode
204 | // was turned on.
205 | func displayLog() {
206 | 	if !testing.Verbose() {
207 | 		return
208 | 	}
209 | 
210 | 	logdash.WriteTo(os.Stdout)
211 | }
212 | 


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