udp.c

来自「2410 boot loader,usb ftp」· C语言 代码 · 共 86 行

/*
	Copyright 2001-2004 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 = hton4(p->iphdr.src_ip);
			fh.da = hton4(p->iphdr.dst_ip);
			fh.pt = hton(p->iphdr.prot);
			fh.ln = p->length;
			sum = cks_partial (&fh, sizeof fh, 0);
			sum = ~cks_partial (&p->src_port, ntoh(p->length), sum);
		}
		
		if (sum == 0) {
			
        	// Translate network data to host data
            p->src_port = ntoh(p->src_port);
            p->dst_port = ntoh(p->dst_port);
            p->length = ntoh(p->length);

			if (p->dst_port == TFTP_LOCAL_PORT && netif.ip)
				processTFTP ((TFTPDpkt *) p);
			else if (p->src_port == BOOTP_SRV_PORT && p->dst_port == BOOTP_CLI_PORT
				&& netif.ip == 0)
				processBOOTP ((BOOTPpkt *) p);
		
		}
	}
}

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 = hton(src_port);
	p->dst_port = hton(dst_port);
	fh.ln = p->length = hton(len);
	p->cks = 0;
	fh.sa = hton4(netif.ip);
	fh.da = hton4(dst_ip);
	fh.pt = hton(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);
}