Statistics
| Branch: | Revision:

root / arduino-1.0 / libraries / Ethernet / EthernetUdp.cpp @ 58d82c77

History | View | Annotate | Download (4.5 KB)

1
/*
2
 *  Udp.cpp: Library to send/receive UDP packets with the Arduino ethernet shield.
3
 *  This version only offers minimal wrapping of socket.c/socket.h
4
 *  Drop Udp.h/.cpp into the Ethernet library directory at hardware/libraries/Ethernet/ 
5
 *
6
 * MIT License:
7
 * Copyright (c) 2008 Bjoern Hartmann
8
 * Permission is hereby granted, free of charge, to any person obtaining a copy
9
 * of this software and associated documentation files (the "Software"), to deal
10
 * in the Software without restriction, including without limitation the rights
11
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12
 * copies of the Software, and to permit persons to whom the Software is
13
 * furnished to do so, subject to the following conditions:
14
 * 
15
 * The above copyright notice and this permission notice shall be included in
16
 * all copies or substantial portions of the Software.
17
 * 
18
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24
 * THE SOFTWARE.
25
 *
26
 * bjoern@cs.stanford.edu 12/30/2008
27
 */
28

    
29
#include "w5100.h"
30
#include "socket.h"
31
#include "Ethernet.h"
32
#include "Udp.h"
33
#include "Dns.h"
34

    
35
/* Constructor */
36
EthernetUDP::EthernetUDP() : _sock(MAX_SOCK_NUM) {}
37

    
38
/* Start EthernetUDP socket, listening at local port PORT */
39
uint8_t EthernetUDP::begin(uint16_t port) {
40
  if (_sock != MAX_SOCK_NUM)
41
    return 0;
42

    
43
  for (int i = 0; i < MAX_SOCK_NUM; i++) {
44
    uint8_t s = W5100.readSnSR(i);
45
    if (s == SnSR::CLOSED || s == SnSR::FIN_WAIT) {
46
      _sock = i;
47
      break;
48
    }
49
  }
50

    
51
  if (_sock == MAX_SOCK_NUM)
52
    return 0;
53

    
54
  _port = port;
55
  socket(_sock, SnMR::UDP, _port, 0);
56

    
57
  return 1;
58
}
59

    
60
/* Is data available in rx buffer? Returns 0 if no, number of available bytes if yes. 
61
 * returned value includes 8 byte UDP header!*/
62
int EthernetUDP::available() {
63
  return W5100.getRXReceivedSize(_sock);
64
}
65

    
66
/* Release any resources being used by this EthernetUDP instance */
67
void EthernetUDP::stop()
68
{
69
  if (_sock == MAX_SOCK_NUM)
70
    return;
71

    
72
  close(_sock);
73

    
74
  EthernetClass::_server_port[_sock] = 0;
75
  _sock = MAX_SOCK_NUM;
76
}
77

    
78
int EthernetUDP::beginPacket(const char *host, uint16_t port)
79
{
80
  // Look up the host first
81
  int ret = 0;
82
  DNSClient dns;
83
  IPAddress remote_addr;
84

    
85
  dns.begin(Ethernet.dnsServerIP());
86
  ret = dns.getHostByName(host, remote_addr);
87
  if (ret == 1) {
88
    return beginPacket(remote_addr, port);
89
  } else {
90
    return ret;
91
  }
92
}
93

    
94
int EthernetUDP::beginPacket(IPAddress ip, uint16_t port)
95
{
96
  _offset = 0;
97
  return startUDP(_sock, rawIPAddress(ip), port);
98
}
99

    
100
int EthernetUDP::endPacket()
101
{
102
  return sendUDP(_sock);
103
}
104

    
105
size_t EthernetUDP::write(uint8_t byte)
106
{
107
  return write(&byte, 1);
108
}
109

    
110
size_t EthernetUDP::write(const uint8_t *buffer, size_t size)
111
{
112
  uint16_t bytes_written = bufferData(_sock, _offset, buffer, size);
113
  _offset += bytes_written;
114
  return bytes_written;
115
}
116

    
117
int EthernetUDP::parsePacket()
118
{
119
  if (available() > 0)
120
  {
121
    //HACK - hand-parse the UDP packet using TCP recv method
122
    uint8_t tmpBuf[8];
123
    int ret =0;        
124
    //read 8 header bytes and get IP and port from it
125
    ret = recv(_sock,tmpBuf,8);
126
    if (ret > 0)
127
    {
128
      _remoteIP = tmpBuf;
129
      _remotePort = tmpBuf[4];
130
      _remotePort = (_remotePort << 8) + tmpBuf[5];
131
      // When we get here, any remaining bytes are the data
132
      ret = available();
133
    }
134
    return ret;
135
  }
136
  // There aren't any packets available
137
  return 0;
138
}
139

    
140
int EthernetUDP::read()
141
{
142
  uint8_t byte;
143
  if (recv(_sock, &byte, 1) > 0)
144
  {
145
    // We read things without any problems
146
    return byte;
147
  }
148
  // If we get here, there's no data available
149
  return -1;
150
}
151

    
152
int EthernetUDP::read(unsigned char* buffer, size_t len)
153
{
154
  /* In the readPacket that copes with truncating packets, the buffer was
155
     filled with this code.  Not sure why it loops round reading out a byte
156
     at a time.
157
  int i;
158
  for(i=0;i<(int)bufLen;i++) {
159
    recv(_sock,tmpBuf,1);
160
    buf[i]=tmpBuf[0];
161
  }
162
  */
163
  return recv(_sock, buffer, len);
164
}
165

    
166
int EthernetUDP::peek()
167
{
168
  uint8_t b;
169
  // Unlike recv, peek doesn't check to see if there's any data available, so we must
170
  if (!available())
171
    return -1;
172
  ::peek(_sock, &b);
173
  return b;
174
}
175

    
176
void EthernetUDP::flush()
177
{
178
  while (available())
179
  {
180
    read();
181
  }
182
}
183