mirror of https://github.com/noisymime/Arduino.git
130 lines
4.6 KiB
C++
130 lines
4.6 KiB
C++
/*
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* Udp.cpp: Library to send/receive UDP packets with the Arduino ethernet shield.
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* This version only offers minimal wrapping of socket.c/socket.h
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* Drop Udp.h/.cpp into the Ethernet library directory at hardware/libraries/Ethernet/
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*
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* MIT License:
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* Copyright (c) 2008 Bjoern Hartmann
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*
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* bjoern@cs.stanford.edu 12/30/2008
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*/
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#include "w5100.h"
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#include "socket.h"
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#include "ethernet.h"
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#include "udp.h"
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/* Start UDP socket, listening at local port PORT */
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void UdpClass::begin(uint16_t port) {
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_port = port;
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_sock = 0; //TODO: should not be hardcoded
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socket(_sock, SnMR::UDP, _port, 0);
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}
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/* Send packet contained in buf of length len to peer at specified ip, and port */
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/* Use this function to transmit binary data that might contain 0x00 bytes*/
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/* This function returns sent data size for success else -1. */
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uint16_t UdpClass::sendPacket(uint8_t * buf, uint16_t len, uint8_t * ip, uint16_t port){
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return sendto(_sock,(const uint8_t *)buf,len,ip,port);
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}
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/* Send zero-terminated string str as packet to peer at specified ip, and port */
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/* This function returns sent data size for success else -1. */
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uint16_t UdpClass::sendPacket(const char str[], uint8_t * ip, uint16_t port){
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// compute strlen
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const char *s;
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for(s = str; *s; ++s);
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uint16_t len = (s-str);
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// send packet
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return sendto(_sock,(const uint8_t *)str,len,ip,port);
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}
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/* Is data available in rx buffer? Returns 0 if no, number of available bytes if yes.
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* returned value includes 8 byte UDP header!*/
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int UdpClass::available() {
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return W5100.getRXReceivedSize(_sock);
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}
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/* Read a received packet into buffer buf (which is of maximum length len); */
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/* store calling ip and port as well. Call available() to make sure data is ready first. */
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/* NOTE: I don't believe len is ever checked in implementation of recvfrom(),*/
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/* so it's easy to overflow buffer. so we check and truncate. */
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/* returns number of bytes read, or negative number of bytes we would have needed if we truncated */
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int UdpClass::readPacket(uint8_t * buf, uint16_t bufLen, uint8_t *ip, uint16_t *port) {
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int packetLen = available()-8; //skip UDP header;
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if(packetLen < 0 ) return 0; // no real data here
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if(packetLen > (int)bufLen) {
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//packet is too large - truncate
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//HACK - hand-parse the UDP packet using TCP recv method
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uint8_t tmpBuf[8];
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int i;
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//read 8 header bytes and get IP and port from it
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recv(_sock,tmpBuf,8);
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ip[0] = tmpBuf[0];
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ip[1] = tmpBuf[1];
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ip[2] = tmpBuf[2];
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ip[3] = tmpBuf[3];
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*port = tmpBuf[4];
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*port = (*port << 8) + tmpBuf[5];
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//now copy first (bufLen) bytes into buf
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for(i=0;i<(int)bufLen;i++) {
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recv(_sock,tmpBuf,1);
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buf[i]=tmpBuf[0];
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}
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//and just read the rest byte by byte and throw it away
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while(available()) {
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recv(_sock,tmpBuf,1);
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}
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return (-1*packetLen);
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//ALTERNATIVE: requires stdlib - takes a bunch of space
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/*//create new buffer and read everything into it
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uint8_t * tmpBuf = (uint8_t *)malloc(packetLen);
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recvfrom(_sock,tmpBuf,packetLen,ip,port);
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if(!tmpBuf) return 0; //couldn't allocate
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// copy first bufLen bytes
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for(unsigned int i=0; i<bufLen; i++) {
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buf[i]=tmpBuf[i];
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}
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//free temp buffer
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free(tmpBuf);
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*/
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}
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return recvfrom(_sock,buf,bufLen,ip,port);
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}
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/* Read a received packet, throw away peer's ip and port. See note above. */
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int UdpClass::readPacket(uint8_t * buf, uint16_t len) {
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uint8_t ip[4];
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uint16_t port[1];
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return recvfrom(_sock,buf,len,ip,port);
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}
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/* Create one global object */
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UdpClass Udp;
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