Adding SPI library and revising Ethernet library (Christian Maglie).

libraries/Ethernet/Udp.cpp

@@ -0,0 +1,129 @@
+/*
+ *  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<bufLen; i++) {
+     			buf[i]=tmpBuf[i];
+     		}
+     		//free temp buffer
+     		free(tmpBuf);
+     		*/
+
+
+  } 
+  return recvfrom(_sock,buf,bufLen,ip,port);
+}
+
+/* Read a received packet, throw away peer's ip and port.  See note above. */
+int UdpClass::readPacket(uint8_t * buf, uint16_t len) {
+  uint8_t ip[4];
+  uint16_t port[1];
+  return recvfrom(_sock,buf,len,ip,port);
+}
+
+
+
+
+/* Create one global object */
+UdpClass Udp;