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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 |