Jaap Vermaas
This is a simple but complete TFTP server, It can receive and send files and listens on port 69. It is part of the LaOS (Laser Open Source) project: http://www.laoslaser.org/
Dependents: TFTPServerTest RMFWeb
Diff: TFTPServer.cpp
- Revision:
- 0:3b0027b76acf
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/TFTPServer.cpp Mon Dec 26 18:18:32 2011 +0000
@@ -0,0 +1,403 @@
+/*
+ * TFTPServer.cpp
+ * Simple TFTP server
+ *
+ * Copyright (c) 2011 Jaap Vermaas
+ *
+ * This file is part of the LaOS project (see: http://wiki.laoslaser.org)
+ *
+ * LaOS is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * LaOS is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with LaOS. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#include "TFTPServer.h"
+
+// create a new tftp server, with file directory dir and
+// listening on port
+TFTPServer::TFTPServer(char* dir) {
+ ListenSock = new UDPSocket();
+ ListenSock->setOnEvent(this, &TFTPServer::onListenUDPSocketEvent);
+ state = listen;
+ if (ListenSock->bind(Host(IpAddr(), TFTP_PORT)))
+ state = error;
+ TFTPServerTimer.attach(this, &TFTPServer::cleanUp, 5000);
+ sprintf(workdir, "%s", dir);
+ filecnt = 0;
+}
+
+// destroy this instance of the tftp server
+TFTPServer::~TFTPServer() {
+ ListenSock->resetOnEvent();
+ delete(ListenSock);
+ delete(remote);
+ state = deleted;
+}
+
+void TFTPServer::reset() {
+ ListenSock->resetOnEvent();
+ delete(ListenSock);
+ delete(remote);
+ TFTPServerTimer.detach();
+ ListenSock = new UDPSocket();
+ ListenSock->setOnEvent(this, &TFTPServer::onListenUDPSocketEvent);
+ state = listen;
+ if (ListenSock->bind(Host(IpAddr(), TFTP_PORT)))
+ state = error;
+ TFTPServerTimer.attach(this, &TFTPServer::cleanUp, 5000);
+ sprintf(filename, "");
+ filecnt = 0;
+}
+
+// get current tftp status
+TFTPServerState TFTPServer::State() {
+ return state;
+}
+
+// Temporarily disable incoming TFTP connections
+void TFTPServer::suspend() {
+ state = suspended;
+}
+
+// Resume after suspension
+void TFTPServer::resume() {
+ if (state == suspended)
+ state = listen;
+}
+
+// During read and write, this gives you the filename
+void TFTPServer::getFilename(char* name) {
+ sprintf(name, "%s", filename);
+}
+
+// return number of received files
+int TFTPServer::fileCnt() {
+ return filecnt;
+}
+
+// create a new connection reading a file from server
+void TFTPServer::ConnectRead(char* buff, Host* client) {
+ IpAddr clientIp = client->getIp();
+ int clientPort = client->getPort();
+ remote = new Host(clientIp, clientPort);
+ Ack(0);
+ blockcnt = 0;
+ dupcnt = 0;
+
+ sprintf(filename, "%s%s", workdir, &buff[2]);
+
+ fp = fopen(filename, "rb");
+ if (fp == NULL) {
+ state = listen;
+ delete(remote);
+ Err("Could not read file", client);
+ } else {
+ // file ready for reading
+ blockcnt = 0;
+ state = reading;
+ #ifdef TFTP_DEBUG
+ char debugmsg[256];
+ sprintf(debugmsg, "Listen: Requested file %s from TFTP connection %d.%d.%d.%d port %d",
+ filename, clientIp[0], clientIp[1], clientIp[2], clientIp[3], clientPort);
+ TFTP_DEBUG(debugmsg);
+ #endif
+ getBlock();
+ sendBlock();
+ }
+}
+
+// create a new connection writing a file to the server
+void TFTPServer::ConnectWrite(char* buff, Host* client) {
+ IpAddr clientIp = client->getIp();
+ int clientPort = client->getPort();
+ remote = new Host(clientIp, clientPort);
+ Ack(0);
+ blockcnt = 0;
+ dupcnt = 0;
+
+ sprintf(filename, "%s%s", workdir, &buff[2]);
+
+ fp = fopen(filename, "wb");
+ if (fp == NULL) {
+ Err("Could not open file to write", client);
+ state = listen;
+ delete(remote);
+ } else {
+ // file ready for writing
+ blockcnt = 0;
+ state = writing;
+ #ifdef TFTP_DEBUG
+ char debugmsg[256];
+ sprintf(debugmsg, "Listen: Incoming file %s on TFTP connection from %d.%d.%d.%d clientPort %d",
+ filename, clientIp[0], clientIp[1], clientIp[2], clientIp[3], clientPort);
+ TFTP_DEBUG(debugmsg);
+ #endif
+ }
+}
+
+// get DATA block from file on disk into memory
+void TFTPServer::getBlock() {
+ blockcnt++;
+ char *p;
+ p = &sendbuff[4];
+ int len = fread(p, 1, 512, fp);
+ sendbuff[0] = 0x00;
+ sendbuff[1] = 0x03;
+ sendbuff[2] = blockcnt >> 8;
+ sendbuff[3] = blockcnt & 255;
+ blocksize = len+4;
+}
+
+// send DATA block to the client
+void TFTPServer::sendBlock() {
+ ListenSock->sendto(sendbuff, blocksize, remote);
+}
+
+
+// compare host IP and Port with connected remote machine
+int TFTPServer::cmpHost(Host* client) {
+ IpAddr clientIp = client->getIp();
+ IpAddr remoteIp = remote->getIp();
+ int clientPort = client->getPort();
+ int remotePort = remote->getPort();
+ return ((clientIp == remoteIp) && (clientPort == remotePort));
+}
+
+// send ACK to remote
+void TFTPServer::Ack(int val) {
+ char ack[4];
+ ack[0] = 0x00;
+ ack[1] = 0x04;
+ if ((val>603135) || (val<0)) val = 0;
+ ack[2] = val >> 8;
+ ack[3] = val & 255;
+ ListenSock->sendto(ack, 4, remote);
+}
+
+// send ERR message to named client
+void TFTPServer::Err(char* msg, Host* client) {
+ char message[32];
+ strncpy(message, msg, 32);
+ char err[37];
+ sprintf(err, "0000%s0", message);
+ err[0] = 0x00;
+ err[1] = 0x05;
+ err[2]=0x00;
+ err[3]=0x00;
+ int len = strlen(err);
+ err[len-1] = 0x00;
+ ListenSock->sendto(err, len, client);
+ #ifdef TFTP_DEBUG
+ char debugmsg[256];
+ sprintf(debugmsg, "Error: %s", message);
+ TFTP_DEBUG(debugmsg);
+ #endif
+}
+
+// check if connection mode of client is octet/binary
+int TFTPServer::modeOctet(char* buff) {
+ int x = 2;
+ while (buff[x++] != 0); // get beginning of mode field
+ int y = x;
+ while (buff[y] != 0) {
+ buff[y] = tolower(buff[y]);
+ y++;
+ } // make mode field lowercase
+ return (strcmp(&buff[x++], "octet") == 0);
+}
+
+// timed routine to avoid hanging after interrupted transfers
+void TFTPServer::cleanUp() {
+ static int lastcnt;
+ switch (state) {
+ case reading:
+ if (lastcnt == blockcnt) {
+ fclose(fp);
+ state=listen;
+ delete(remote);
+ }
+ break;
+ case writing:
+ if (lastcnt == blockcnt) {
+ fclose(fp);
+ state = listen;
+ remove(filename);
+ delete(remote);
+ }
+ break;
+ } // state
+ lastcnt = blockcnt;
+}
+
+// event driven routines to handle incoming packets
+void TFTPServer::onListenUDPSocketEvent(UDPSocketEvent e) {
+ extern SDFileSystem sd;
+ Host* client = new Host();
+ char buff[516];
+ if (e == UDPSOCKET_READABLE) {
+ switch (state) {
+ case listen:
+ if (int len = ListenSock->recvfrom(buff, 516, client)) {
+ switch (buff[1]) {
+ case 0x01: // RRQ
+ if (modeOctet(buff))
+ ConnectRead(buff, client);
+ else
+ Err("Not in octet mode", client);
+ break;
+ case 0x02: // WRQ
+ if (modeOctet(buff))
+ ConnectWrite(buff, client);
+ else
+ Err("Not in octet mode", client);
+ break;
+ case 0x03: // DATA before connection established
+ Err("No data expected", client);
+ break;
+ case 0x04: // ACK before connection established
+ Err("No ack expected", client);
+ break;
+ case 0x05: // ERROR packet received
+ #ifdef TFTP_DEBUG
+ TFTP_DEBUG("TFTP Eror received\n\r");
+ #endif
+ break;
+ default: // unknown TFTP packet type
+ Err("Unknown TFTP packet type", client);
+ break;
+ } // switch buff[1]
+ } // recvfrom
+ break; // case listen
+ case reading:
+ while (int len = ListenSock->recvfrom(buff, 516, client) ) {
+ switch (buff[1]) {
+ case 0x01:
+ // if this is the receiving host, send first packet again
+ if ((cmpHost(client) && blockcnt==1)) {
+ sendBlock();
+ dupcnt++;
+ }
+ if (dupcnt>10) { // too many dups, stop sending
+ fclose(fp);
+ state=listen;
+ delete(remote);
+ }
+ break;
+ case 0x02:
+ // this should never happen, ignore
+ break; // case 0x02
+ case 0x03:
+ // we are the sending side, ignore
+ break;
+ case 0x04:
+ // last packet received, send next if there is one
+ dupcnt = 0;
+ if (blocksize == 516) {
+ getBlock();
+ sendBlock();
+ } else { //EOF
+ fclose(fp);
+ state = listen;
+ delete(remote);
+ }
+ break;
+ default: // this includes 0x05 errors
+ fclose(fp);
+ state = listen;
+ delete(remote);
+ break;
+ } // switch (buff[1])
+ } // while
+ break; // reading
+ case writing:
+ while (int len = ListenSock->recvfrom(buff, 516, client) ) {
+ switch (buff[1]) {
+ case 0x02:
+ // if this is a returning host, send ack again
+ if (cmpHost(client)) {
+ Ack(0);
+ #ifdef TFTP_DEBUG
+ TFTP_DEBUG("Resending Ack on WRQ");
+ #endif
+ }
+ break; // case 0x02
+ case 0x03:
+ if (cmpHost(client)) { // check if this is our partner
+ int block = (buff[2] << 8) + buff[3];
+ if ((blockcnt+1) == block) {
+ Ack(block);
+ // new packet
+ char *data = &buff[4];
+ fwrite(data, 1,len-4, fp);
+ blockcnt++;
+ dupcnt = 0;
+ } else {
+ if ((blockcnt+1) < block) { // high block nr
+ // we missed a packet, error
+ #ifdef TFTP_DEBUG
+ TFTP_DEBUG("Missed packet!");
+ #endif
+ fclose(fp);
+ state = listen;
+ remove(filename);
+ delete(remote);
+ } else { // duplicate packet, do nothing
+ #ifdef TFTP_DEBUG
+ char debugmsg[256];
+ sprintf(debugmsg, "Dupblicate packet %d", blockcnt);
+ TFTP_DEBUG(debugmsg);
+ #endif
+ if (dupcnt > 10) {
+ Err("Too many dups", client);
+ fclose(fp);
+ remove(filename);
+ state = listen;
+ } else {
+ Ack(blockcnt);
+ }
+ dupcnt++;
+ }
+ }
+ //printf ("Read packet %d with blocksize = %d\n\r", blockcnt, len);
+ if (len<516) {
+ #ifdef TFTP_DEBUG
+ char debugmsg[256];
+ sprintf(debugmsg, "Read last block %d", len);
+ TFTP_DEBUG(debugmsg);
+ #endif
+ fclose(fp);
+ state = listen;
+ delete(remote);
+ filecnt++;
+ }
+ break; // case 0x03
+ } else // if cmpHost
+ Err("Wrong IP/Port: Not your connection!", client);
+ break; // case 0x03
+ default:
+ Err("No idea why you're sending me this!", client);
+ break; // default
+ } // switch (buff[1])
+ } // while
+ break; // writing
+ case suspended:
+ if (int len = ListenSock->recvfrom(buff, 516, client))
+ Err("Packet received on suspended socket, discarded", client);
+ break;
+ } // state
+ } else {
+ #ifdef TFTP_DEBUG
+ TFTP_DEBUG("TFTP unknown UDP status");
+ #endif
+ }
+ delete(client);
+}