udp.c

mc51单片机对rtl8019编程,实现ethernet的收发控制.

#include "ethernet.h"
#include "ip.h"
#include "udp.h"
#include "ring.h"
#include "arp.h"
extern 	Net_inf_struc 	net_inf;
xdata Uint8 tx_buf[1500];
ring_struc ring;

Uint8 rx_buf[MAX_DUP_BUFFER_LENGTH*MAX_DUP_BUFFER_COUNT];

Bool udp_open(Uint8 *pip,Uint16 port_local,Uint16 port_remote)
{
	if(net_inf.portnumber_local)
		return FALSE;
	net_inf.portnumber_local = port_local;
	net_inf.portnumber_remote = port_remote;
	if(pip==NULL)
		memset(net_inf.ip_remote,0,INADDR_LEN);
	else
		memcpy(net_inf.ip_remote,pip,INADDR_LEN);
	ring_init(&ring,rx_buf,MAX_DUP_BUFFER_LENGTH,MAX_DUP_BUFFER_COUNT);
}
void udp_close()
{
	net_inf.portnumber_local = 0;
	net_inf.portnumber_remote = 0;
}

Bool udp_sendto(Uint8 *pip,Uint16 remote_port,Uint8 *pbuf,Uint16 length)
{
	xdata  Ip_struc* ipPkt;
	xdata  Udphdr_struc* udpPkt;
	
	ipPkt = ( Ip_struc*) (tx_buf + sizeof(Ether_header_struc));
	udpPkt = ( Udphdr_struc*) ((Uint8*) ipPkt + sizeof(Ip_struc));
	// UDP header
	udpPkt->source = net_inf.portnumber_local ;
	udpPkt->dest = remote_port;
	udpPkt->len = length+sizeof(Udphdr_struc);
	udpPkt->check = 0;
	//content
	memcpy((Uint16 *)udpPkt+ sizeof(Udphdr_struc),pbuf,length);
	// destination IP
	memcpy(&ipPkt->ip_dst, pip, INADDR_LEN);
	// fill source address for checksum - use a zero ip address if we do not have one (eg sending bootp)
	memcpy(&ipPkt->ip_src, net_inf.ip_local, INADDR_LEN);
	// packet length, protocol & id are the same
	ipPkt->ip_len = udpPkt->len + sizeof(Ip_struc);
	ipPkt->ip_p = IPPROTO_UDP;
	ipPkt->ip_id = 0;
	ipPkt->ip_ttl = 64;
	// insert checksum & send
	//udpPkt->check = cpu_checksum(( Uint16 *) ipPkt, (aLength | CPU_CHECKSUM_INC_IP) - sizeof(Ip_struc));
	return ip_send(tx_buf);
}
Bool udp_send(Uint8 *pbuf,Uint16 length)
{
	return udp_sendto(net_inf.ip_remote,net_inf.portnumber_remote,pbuf,length);
}
Uint16 udp_recv(Uint8 *pbuf,Uint16 length)
{	
	Uint16 i;
	if(ring_read(&ring,tx_buf)){
		i = tx_buf[0]<<8;
	 	i |= tx_buf[1];
		length = Min(length,i);
		memcpy(pbuf,tx_buf+2,length);
		return length;
	}
	return 0;
}
void udp_process(Uint8* pudp)
{
	xdata  Udphdr_struc* udpPkt;
	udpPkt = (Udphdr_struc*)pudp;
	if(udpPkt->dest != net_inf.portnumber_local)
    	return;
	if(net_inf.portnumber_remote == 0)
 		net_inf.portnumber_remote = udpPkt->source;
	if(udpPkt->source != net_inf.portnumber_remote)
    	return;
	udpPkt->check = udpPkt->len-sizeof(Udphdr_struc);
	ring_write(&ring,pudp+sizeof(Udphdr_struc)-2);
}
				 
void tick()
{
	xdata Uint8 buffer[1500]; 
	Uint16 i;
	if(ethernet_receive(buffer)){
		i = buffer[12]<<8;
	 	i |= buffer[13];
		switch(i){
				case ETHERTYPE_IP:
					ip_receive(buffer);
					break;
				case ETHERTYPE_ARP:
					arp_receive(buffer);
					break;
			}	
	}	
 
}