From fc944ff979dbbd49a57722fe2d1d2acf47312eb4 Mon Sep 17 00:00:00 2001 From: Jesse Morgan Date: Thu, 20 Oct 2011 22:16:19 -0700 Subject: Inital commit... halfway through the project --- libraries/Ethernet/Udp.cpp | 136 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) create mode 100644 libraries/Ethernet/Udp.cpp (limited to 'libraries/Ethernet/Udp.cpp') diff --git a/libraries/Ethernet/Udp.cpp b/libraries/Ethernet/Udp.cpp new file mode 100644 index 0000000..e4185f6 --- /dev/null +++ b/libraries/Ethernet/Udp.cpp @@ -0,0 +1,136 @@ +/* + * 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/ + * + * 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 + */ + +#include "w5100.h" +#include "socket.h" +#include "Ethernet.h" +#include "Udp.h" + +/* Start UDP socket, listening at local port PORT */ +void UdpClass::begin(uint16_t port) { + _port = port; + _sock = 0; //TODO: should not be hardcoded + socket(_sock, SnMR::UDP, _port, 0); +} + +/* Send packet contained in buf of length len to peer at specified ip, and port */ +/* Use this function to transmit binary data that might contain 0x00 bytes*/ +/* This function returns sent data size for success else -1. */ +uint16_t UdpClass::sendPacket(uint8_t * buf, uint16_t len, uint8_t * ip, uint16_t port){ + return sendto(_sock,(const uint8_t *)buf,len,ip,port); +} + +/* Send zero-terminated string str as packet to peer at specified ip, and port */ +/* This function returns sent data size for success else -1. */ +uint16_t UdpClass::sendPacket(const char str[], uint8_t * ip, uint16_t port){ + // compute strlen + const char *s; + for(s = str; *s; ++s); + uint16_t len = (s-str); + // send packet + return sendto(_sock,(const uint8_t *)str,len,ip,port); +} +/* Is data available in rx buffer? Returns 0 if no, number of available bytes if yes. + * returned value includes 8 byte UDP header!*/ +int UdpClass::available() { + return W5100.getRXReceivedSize(_sock); +} + + +/* Read a received packet into buffer buf (which is of maximum length len); */ +/* store calling ip and port as well. Call available() to make sure data is ready first. */ +/* NOTE: I don't believe len is ever checked in implementation of recvfrom(),*/ +/* so it's easy to overflow buffer. so we check and truncate. */ +/* returns number of bytes read, or negative number of bytes we would have needed if we truncated */ +int UdpClass::readPacket(uint8_t * buf, uint16_t bufLen, uint8_t *ip, uint16_t *port) { + int packetLen = available()-8; //skip UDP header; + if(packetLen < 0 ) return 0; // no real data here + if(packetLen > (int)bufLen) { + //packet is too large - truncate + //HACK - hand-parse the UDP packet using TCP recv method + uint8_t tmpBuf[8]; + int i; + //read 8 header bytes and get IP and port from it + recv(_sock,tmpBuf,8); + ip[0] = tmpBuf[0]; + ip[1] = tmpBuf[1]; + ip[2] = tmpBuf[2]; + ip[3] = tmpBuf[3]; + *port = tmpBuf[4]; + *port = (*port << 8) + tmpBuf[5]; + + //now copy first (bufLen) bytes into buf + for(i=0;i<(int)bufLen;i++) { + recv(_sock,tmpBuf,1); + buf[i]=tmpBuf[0]; + } + + //and just read the rest byte by byte and throw it away + while(available()) { + recv(_sock,tmpBuf,1); + } + + return (-1*packetLen); + + //ALTERNATIVE: requires stdlib - takes a bunch of space + /*//create new buffer and read everything into it + uint8_t * tmpBuf = (uint8_t *)malloc(packetLen); + recvfrom(_sock,tmpBuf,packetLen,ip,port); + if(!tmpBuf) return 0; //couldn't allocate + // copy first bufLen bytes + for(unsigned int i=0; i