1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
/*
* Udp.cpp: Library to send/receive UDP packets with the Arduino ethernet shield.
* This version only offers minimal wrapping of socket.c/socket.h
* Drop Udp.h/.cpp into the Ethernet library directory at hardware/libraries/Ethernet/
*
* NOTE: UDP is fast, but has some important limitations (thanks to Warren Gray for mentioning these)
* 1) UDP does not guarantee the order in which assembled UDP packets are received. This
* might not happen often in practice, but in larger network topologies, a UDP
* packet can be received out of sequence.
* 2) UDP does not guard against lost packets - so packets *can* disappear without the sender being
* aware of it. Again, this may not be a concern in practice on small local networks.
* For more information, see http://www.cafeaulait.org/course/week12/35.html
*
* MIT License:
* Copyright (c) 2008 Bjoern Hartmann
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
* bjoern@cs.stanford.edu 12/30/2008
*/
#ifndef udp_h
#define udp_h
#include <Stream.h>
#include <IPAddress.h>
#define UDP_TX_PACKET_MAX_SIZE 24
class UDP : public Stream {
private:
uint8_t _sock; // socket ID for Wiz5100
uint16_t _port; // local port to listen on
IPAddress _remoteIP; // remote IP address for the incoming packet whilst it's being processed
uint16_t _remotePort; // remote port for the incoming packet whilst it's being processed
uint16_t _offset; // offset into the packet being sent
public:
UDP(); // Constructor
uint8_t begin(uint16_t); // initialize, start listening on specified port. Returns 1 if successful, 0 if there are no sockets available to use
void stop(); // Finish with the UDP socket
// Sending UDP packets
// Start building up a packet to send to the remote host specific in ip and port
// Returns 1 if successful, 0 if there was a problem with the supplied IP address or port
int beginPacket(IPAddress ip, uint16_t port);
// Start building up a packet to send to the remote host specific in host and port
// Returns 1 if successful, 0 if there was a problem resolving the hostname or port
int beginPacket(const char *host, uint16_t port);
// Finish off this packet and send it
// Returns 1 if the packet was sent successfully, 0 if there was an error
int endPacket();
// Write a single byte into the packet
virtual void write(uint8_t);
// Write a string of characters into the packet
virtual void write(const char *str);
// Write size bytes from buffer into the packet
virtual void write(const uint8_t *buffer, size_t size);
// Start processing the next available incoming packet
// Returns the size of the packet in bytes, or 0 if no packets are available
int parsePacket();
// Number of bytes remaining in the current packet
virtual int available();
// Read a single byte from the current packet
virtual int read();
// Read up to len bytes from the current packet and place them into buffer
// Returns the number of bytes read, or 0 if none are available
virtual int read(unsigned char* buffer, size_t len);
// Read up to len characters from the current packet and place them into buffer
// Returns the number of characters read, or 0 if none are available
virtual int read(char* buffer, size_t len) { return read((unsigned char*)buffer, len); };
// Return the next byte from the current packet without moving on to the next byte
virtual int peek();
virtual void flush(); // Finish reading the current packet
// Return the IP address of the host who sent the current incoming packet
IPAddress remoteIP() { return _remoteIP; };
// Return the port of the host who sent the current incoming packet
uint16_t remotePort() { return _remotePort; };
};
#endif
|
