net_fun.c

dsp下网络通信实验,很有用哦.平台为DSP54

#include	"netcom.h"
#include	"net_fun.h"
#include	"sys.h"

extern	u8_t 	UdpDestEthAddr[6];
extern	u8_t	UdpDestIpAddr[4];
extern	u16_t	UdpDestPort;
extern	u16_t	UdpSrcPort;

extern	u8_t	MyEthAddr[6];
extern	u8_t	MyIpAddr[4];

extern	u8_t 	ArpDestEthAddr[6];
extern	u8_t	ArpDestIpAddr[4];
	
extern u16_t	AppDataLen;
extern u16_t	SendDataLen;
void udp_hdr_make(u16_t len,u16_t offset,u16_t *pdata,u16_t datalen);
/*
 * ************************************************************
 * makehdr
 * ok,no depend extern
 * ***********************************************************
 */
void makehdr(u16_t proto,u16_t len,u16_t offset,u16_t *pdata,u16_t datalen)
{
	
	switch(proto){
		case	PROTO_UDP:
			udp_hdr_make(len,offset,pdata,datalen);
			break;
		case 	ETH_P_ARP:
			break;
		default:
			break;
	}
}
/*
 * **********************************************************
 * udp_hdr_make
 * ok,no depend extern
 * len	-->the eth_ip_udp header length
 * offset-->offset of where store the header
 * pdata--->store where
 * datalen-->app data len
 * no return
 * **********************************************************
 */
void udp_hdr_make(u16_t len,u16_t offset,u16_t *pdata,u16_t datalen)
{
	int DATAID = 0x1111;
	eth_ip_udp_hdr *phdr = ((eth_ip_udp_hdr *)&pdata[offset]);
	/* ethhdr */
	phdr->ehdr.destaddr0 = UdpDestEthAddr[0];
	phdr->ehdr.destaddr1 = UdpDestEthAddr[1];
	phdr->ehdr.destaddr2 = UdpDestEthAddr[2];
	phdr->ehdr.destaddr3 = UdpDestEthAddr[3];
	phdr->ehdr.destaddr4 = UdpDestEthAddr[4];
	phdr->ehdr.destaddr5 = UdpDestEthAddr[5];

	phdr->ehdr.srcaddr0 = MyEthAddr[0];
	phdr->ehdr.srcaddr1 = MyEthAddr[1];
	phdr->ehdr.srcaddr2 = MyEthAddr[2];
	phdr->ehdr.srcaddr3 = MyEthAddr[3];
	phdr->ehdr.srcaddr4 = MyEthAddr[4];
	phdr->ehdr.srcaddr5 = MyEthAddr[5];
	
	phdr->ehdr.proto = ETH_P_IP;
	
	/* iphdr */
	phdr->ihdr.ver = 0x4;
	phdr->ihdr.hdrlen = 0x5;
	phdr->ihdr.tos = 0x00;
	phdr->ihdr.totlen = IPHDR_LEN + UDPHDR_LEN + (datalen << 1);
	phdr->ihdr.id = DATAID;
	phdr->ihdr.frag_offset = 0x0;
	phdr->ihdr.ttl = 0x40;
	phdr->ihdr.proto = 0x11;
	phdr->ihdr.checksum = 0x0000;	//left later calc it
	phdr->ihdr.srcipaddr0 = MyIpAddr[0];
	phdr->ihdr.srcipaddr1 = MyIpAddr[1];
	phdr->ihdr.srcipaddr2 = MyIpAddr[2];
	phdr->ihdr.srcipaddr3 = MyIpAddr[3];
	phdr->ihdr.destipaddr0 = UdpDestIpAddr[0];
	phdr->ihdr.destipaddr1 = UdpDestIpAddr[1];
	phdr->ihdr.destipaddr2 = UdpDestIpAddr[2];
	phdr->ihdr.destipaddr3 = UdpDestIpAddr[3];
	
	/* udphdr */
	phdr->uhdr.srcport = UdpSrcPort;
	phdr->uhdr.destport = UdpDestPort;
	phdr->uhdr.len = UDPHDR_LEN + (datalen << 1);
	phdr->uhdr.checksum = 0x0000;	//later calc it
}
/*
 * *********************************************************
 * checksum
 * independ
 * *********************************************************
 */
u16_t checksum(u16_t len,u16_t offset,u16_t *ppp)
{
	u16_t	_checksum = 0;
	long	sum = 0;
	u16_t 	*p = &ppp[offset];
	
	while(len > 1){
		sum += *p;
		p++;
		if(sum & 0x80000000)
			sum = (sum & 0xffff) + (sum>>16);
		len -= 1;
	}
	if(len)
		sum += *p;
	while(sum >> 16)
		sum = (sum & 0xffff) + (sum >> 16);
	_checksum = ~sum;
	return	_checksum;
}
/*
 * **********************************************************
 * arp
 * return the ethframe len
 * *********************************************************
 */
u16_t arp(u16_t opcode,u8_t dhdaddr[6],u8_t tgtipaddr[4],u16_t *pdata)
{
	int i;
	eth_arp_hdr *hdr = ((eth_arp_hdr *)&pdata[0]);
	/* ethhdr */
		hdr->ehdr.destaddr0 = 0xff;
		hdr->ehdr.destaddr1 = 0xff;
		hdr->ehdr.destaddr2 = 0xff;
		hdr->ehdr.destaddr3 = 0xff;
		hdr->ehdr.destaddr4 = 0xff;
		hdr->ehdr.destaddr5 = 0xff;
	hdr->ehdr.srcaddr0 = MyEthAddr[0];
	hdr->ehdr.srcaddr1 = MyEthAddr[1];
	hdr->ehdr.srcaddr2 = MyEthAddr[2];
	hdr->ehdr.srcaddr3 = MyEthAddr[3];
	hdr->ehdr.srcaddr4 = MyEthAddr[4];
	hdr->ehdr.srcaddr5 = MyEthAddr[5];

	hdr->ehdr.proto = ETH_P_ARP;
	
	/* arphdr */
	hdr->ahdr.hdtype = 0x0001;
	hdr->ahdr.proto = ETH_P_IP;
	hdr->ahdr.hdlen = 0x06;
	hdr->ahdr.protolen = 0x04;
	hdr->ahdr.opcode = opcode;
	hdr->ahdr.send_hd_addr0 = MyEthAddr[0];
	hdr->ahdr.send_hd_addr1 = MyEthAddr[1];
	hdr->ahdr.send_hd_addr2 = MyEthAddr[2];
	hdr->ahdr.send_hd_addr3 = MyEthAddr[3];
	hdr->ahdr.send_hd_addr4 = MyEthAddr[4];
	hdr->ahdr.send_hd_addr5 = MyEthAddr[5];
	hdr->ahdr.send_ip_addr0 = MyIpAddr[0];
	hdr->ahdr.send_ip_addr1 = MyIpAddr[1];
	hdr->ahdr.send_ip_addr2 = MyIpAddr[2];
	hdr->ahdr.send_ip_addr3 = MyIpAddr[3];
	if(opcode == 0x0001){//request
		hdr->ahdr.target_hd_addr0 = 0x00;
		hdr->ahdr.target_hd_addr1 = 0x00;
		hdr->ahdr.target_hd_addr2 = 0x00;
		hdr->ahdr.target_hd_addr3 = 0x00;
		hdr->ahdr.target_hd_addr4 = 0x00;
		hdr->ahdr.target_hd_addr5 = 0x00;
	}else if(opcode == 0x0002){//reply
		hdr->ahdr.target_hd_addr0 = ArpDestEthAddr[0];
		hdr->ahdr.target_hd_addr1 = ArpDestEthAddr[1];
		hdr->ahdr.target_hd_addr2 = ArpDestEthAddr[2];
		hdr->ahdr.target_hd_addr3 = ArpDestEthAddr[3];
		hdr->ahdr.target_hd_addr4 = ArpDestEthAddr[4];
		hdr->ahdr.target_hd_addr5 = ArpDestEthAddr[5];
	}else
		Msg("arp() opcode error!");
		
	hdr->ahdr.target_ip_addr0 = ArpDestIpAddr[0];
	hdr->ahdr.target_ip_addr1 = ArpDestIpAddr[1];
	hdr->ahdr.target_ip_addr2 = ArpDestIpAddr[2];
	hdr->ahdr.target_ip_addr3 = ArpDestIpAddr[3];
	
	for(i = 0;i < 21;i++){
		pdata[i] = htons(pdata[i]);
	}
	//AppDataLen = 18 >> 1;//add it
	//SendDataLen = 60 >> 1;
	return 60 >> 1;		
}
/*
 * **************************************************************
 * totalmake,construct the UDP protocoled data,
 * independ
 * data --->where store the ethnet frame
 * pappdata ----->the application data will send
 * appdatalen -----> applicatiln data len,16 bit counted
 * pappenddata ------> this is what I will append before the application data
 * appenddatalen--->16bit counted,append data length
 * return:ethernet frame length,16bit counted
 * ************************************************************
 */
u16_t totalmake(u16_t *data,u16_t *pappdata,u16_t appdatalen,u16_t *pappenddata,u16_t appenddatalen)
{
	int 	i,j;
	u16_t	ttl;
	eth_ip_udp_hdr	*hdr = (eth_ip_udp_hdr *)data;
	u16_t	ip_checksum;
	u16_t	ethframelen;
	//make protocol header
	makehdr(PROTO_UDP,21,0,data,appdatalen + appenddatalen);

	//copy the append data to data
	for(i = 0,j = 21; i <appenddatalen;i++,j++){
		data[j] = pappenddata[i];
	}

	//copy the application data to data
	for(i = 0,j = 21 + appenddatalen;i < appdatalen;i++,j++){
		data[j] = pappdata[i];
	}
	////now append data add,so the appdatalen => appdatalen + appenddatalen
	appdatalen += appenddatalen;

	//ip checksum
	ip_checksum = checksum(IPHDR_LEN >> 1,ETHHDR_LEN >> 1,data);
	hdr->ihdr.checksum = ip_checksum;
	
	/* make psedu udp hdr */
	ttl = hdr->ihdr.ttl;//save ttl
	hdr->ihdr.checksum = (appdatalen << 1) + UDPHDR_LEN;
	hdr->ihdr.ttl = 0;
	
	//udp checksum
	hdr->uhdr.checksum=checksum((PSEUD_UDPHDR_LEN >> 1) + \
				(UDPHDR_LEN >> 1) + (appdatalen),\
				(ETHHDR_LEN >> 1) + ((IPHDR_LEN - PSEUD_UDPHDR_LEN) >> 1),\
				data);
	//restore the ip_checksum and ttl
	hdr->ihdr.checksum = ip_checksum;
	hdr->ihdr.ttl = ttl;

	ethframelen = appdatalen + ((ETHHDR_LEN + IPHDR_LEN + UDPHDR_LEN) >> 1);
	
	// host to net byte order
	for(i = 0;i < ethframelen;i++){
		data[i] = htons(data[i]);
	}
	if(ethframelen < (ETH_ZLEN >> 1))	
		ethframelen = ETH_ZLEN>>1;
	return ethframelen;
}

/*
 ***********************************************************
 * two nic communication
 * depend on SendDataLen,SendDataBuf,AppDataBuf,AppDataLen
 ***********************************************************
 */