zig-riscv-embedded

 1package main
 2
 3import (
 4	"net"
 5)
 6
 7type CoapEndpoint struct {
 8	conn     net.PacketConn
 9	lastAddr *net.Addr
10	// XXX: mutex?
11
12	RX <-chan []byte
13	TX chan<- []byte
14}
15
16func NewCoapEP(addr string) (*CoapEndpoint, error) {
17	conn, err := net.ListenPacket("udp", addr)
18	if err != nil {
19		return nil, err
20	}
21
22	rx := make(chan []byte)
23	tx := make(chan []byte)
24
25	ep := &CoapEndpoint{
26		conn:     conn,
27		lastAddr: nil,
28		RX:       rx,
29		TX:       tx,
30	}
31
32	go ep.sndLoop(tx)
33	go ep.rcvLoop(rx)
34
35	return ep, nil
36}
37
38func (c *CoapEndpoint) sndLoop(ch <-chan []byte) {
39	for {
40		data := <-ch
41
42		if c.lastAddr == nil {
43			logger.Println("[CoapEndpoint] Unexpected CoAP send")
44			continue
45		}
46
47		_, err := c.conn.WriteTo(data, *c.lastAddr)
48		if err != nil {
49			logger.Println("[CoapEndpoint] WriteTo failed", err)
50			continue
51		}
52	}
53}
54
55func (c *CoapEndpoint) rcvLoop(ch chan<- []byte) {
56	buf := make([]byte, bufSize)
57
58	for {
59		n, addr, err := c.conn.ReadFrom(buf)
60		if err != nil {
61			logger.Println("[CoapEndpoint] ReadFrom failed", err)
62			continue
63		}
64
65		c.lastAddr = &addr
66		ch <- buf[0:n]
67	}
68}
69
70func (c *CoapEndpoint) Close() {
71	// close(c.Chan)
72	c.conn.Close()
73}