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/*
* 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
#define UDP_TX_PACKET_MAX_SIZE 24
class UdpClass {
private:
uint8_t _sock; // socket ID for Wiz5100
uint16_t _port; // local port to listen on
public:
void begin(uint16_t); // initialize, start listening on specified port
int available(); // has data been received?
// C-style buffer-oriented functions
uint16_t sendPacket(uint8_t *, uint16_t, uint8_t *, uint16_t); //send a packet to specified peer
uint16_t sendPacket(const char[], uint8_t *, uint16_t); //send a string as a packet to specified peer
int readPacket(uint8_t *, uint16_t); // read a received packet
int readPacket(uint8_t *, uint16_t, uint8_t *, uint16_t *); // read a received packet, also return sender's ip and port
// readPacket that fills a character string buffer
int readPacket(char *, uint16_t, uint8_t *, uint16_t &);
};
extern UdpClass Udp;
#endif
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