[136] | 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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