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