/*	Copyright 2001, 2002 Georges Menie (www.menie.org)	This file is part of Tftpnaive.    Tftpnaive is free software; you can redistribute it and/or modify    it under the terms of the GNU Lesser General Public License as published by    the Free Software Foundation; either version 2 of the License, or    (at your option) any later version.    Tftpnaive 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 Lesser General Public License for more details.    You should have received a copy of the GNU Lesser General Public License    along with Tftpnaive; if not, write to the Free Software    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA*/#include "tftpnaive.h"#include "net.h"#include "baselib.h"typedef struct {	int sa;	int da;	short pt;	short ln;} fakehdr;void processUDP (unsigned char *pkt, unsigned short len){	register UDPpkt *p = (UDPpkt *) pkt;	register unsigned short sum;	fakehdr fh;	if (len >= sizeof (UDPpkt)) {		if ((sum = p->cks)) {			fh.sa = p->iphdr.src_ip;			fh.da = p->iphdr.dst_ip;			fh.pt = p->iphdr.prot;			fh.ln = p->length;			sum = cks_partial (&fh, sizeof fh, 0);			sum = ~cks_partial (&p->src_port, fh.ln, sum);		}		if (sum == 0) {			if (p->src_port == BOOTP_SRV_PORT && p->dst_port == BOOTP_CLI_PORT				&& netif.ip == 0)				processBOOTP ((BOOTPpkt *) p);			else if (p->dst_port == TFTP_LOCAL_PORT && netif.ip)				processTFTP ((TFTPDpkt *) p);		}		else {			printf ("UDP checksum error\n");		}	}}int sendUDP (UDPpkt * p, unsigned short len, unsigned int dst_ip,			 unsigned short src_port, unsigned short dst_port){	fakehdr fh;	register unsigned short sum;	len += sizeof (UDPpkt) - sizeof (IPpkt);	p->src_port = src_port;	p->dst_port = dst_port;	fh.ln = p->length = len;	p->cks = 0;	fh.sa = netif.ip;	fh.da = dst_ip;	fh.pt = PROTO_UDP;	sum = cks_partial (&fh, sizeof fh, 0);	sum = ~cks_partial (&p->src_port, len, sum);	p->cks = sum ? sum : -1;	return sendIP ((IPpkt *) p, len, PROTO_UDP, dst_ip);}