Udp.h 4.1 KB

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