ip.c

ADS下的bios工程

#include <bios/netdev.h>
#include <bios/checksum.h>
#include <bios/stdio.h>
#include <bios/ctype.h>
#include <bios/string.h>

#undef DEBUG_S3C4_IP
#ifdef DEBUG_S3C4_IP
	#define DEBUG_IP(fmt, args...) printf("%s-%s()[%d]: " fmt, __FILE__, __FUNCTION__, __LINE__, args)
#else
	#define DEBUG_IP(fmt, args...)
#endif


/* extern functions */
extern int arp_lookup(struct netdev *nd, u32 addr, u8 *eth_addr);

static u32 ip_pkt_no;

/* function proto types */
int ip_send(struct netdev *nd, int protocol, u32 from, u32 to, struct buflist *data);
int ip_recv(struct netdev *nd, int protocol, u32 from, u32 to, u8 *buffer);
char *in_ntoa(u32 addr);
unsigned int in_aton(char *s);

char *in_ntoa(u32 addr)
{
	static char buffer[16];

#ifndef BIG_ENDIAN
	sprintf(buffer, "%ld.%ld.%ld.%ld",
		addr & 255,
		(addr >> 8) & 255,
		(addr >> 16) & 255,
		(addr >> 24) & 255);
#else /* BIG_ENDIAN */
	sprintf(buffer, "%ld.%ld.%ld.%ld",
		(addr >> 24) & 255,
		(addr >> 16) & 255,
		(addr >> 8) & 255,
		addr & 255) ;
#endif /* LITTLE_ENDIAN */

	return buffer;
}

unsigned int in_aton(char *s)
{
       unsigned int n[4] = {0,0,0,0};
       char ip[20];
       int i = 0, sp = 0;

       sprintf(ip,"%s",s);

       while(isspace(ip[sp])) sp++; /* get the next charactor */

       for(i = 0; i < 4; i++) 
       {
            while(ip[sp]) 
                 if(isdigit(ip[sp])) n[i]= n[i] * 10 + todecimal(ip[sp++]);
                 else { sp++; break; }

            if(ip[sp] == CR || ip[sp] == (char)NULL) break;
       }

       return htonl(n[0]<<24 | n[1]<<16 | n[2]<<8 | n[3]);
}

static unsigned short ip_check(struct iphdr *ip)
{
	unsigned int check, length = ip->ip_ihl * 4;

	check = ~checksum(ip, length, 0);

	if (check == 0)
		check = -1;

	return htons(check);
}

int ip_send(struct netdev *nd, int protocol, u32 from, u32 to, struct buflist *data)
{
	static u8 hwto[6], *dest;
	static struct buflist bl, *blp;
	static struct iphdr ip;
	int size = 0;


	for (blp = data; blp; blp = blp->next)
		size += blp->size;

	ip.ip_ver    = 4;
	ip.ip_ihl    = 5;
	ip.ip_tos    = 0;
	ip.ip_len    = htons(sizeof(ip) + size);
	ip.ip_id     = htons(ip_pkt_no);
	ip.ip_frag   = 0;
	ip.ip_ttl    = 0x40;
	ip.ip_proto  = protocol;
	ip.ip_check  = 0;
	ip.ip_source = from;
	ip.ip_dest   = to;
	ip.ip_check  = ip_check(&ip);

	ip_pkt_no += 1;

	bl.data = &ip;
	bl.size = sizeof(ip);
	bl.next = data;

	if (to == INADDR_ANY) {
		dest = nd->hw_broadcast;
                DEBUG_IP("dest(%x)\n",dest);
        }
	else if (!arp_lookup(nd, to, hwto)) {
		dest = hwto;
                DEBUG_IP("dest(%x)\n",dest);
        }
	else
		return -1;

	blp = nd->eth_header(nd, dest, ETH_P_IP, &bl);
        
        DEBUG_IP("IP buffer(%x)\n",&bl);
	return blp ? nd->eth_send(nd, blp) : -1;
}

int ip_recv(struct netdev *nd, int protocol, u32 from, u32 to, u8 *buffer)
{
	static u8 ip_buffer[1584];
	static struct iphdr *ip = (struct iphdr *)ip_buffer;
	int bytes, hdrlen;
	int check;


        DEBUG_IP("\n%s", "->");
	bytes = nd->eth_recv(nd, ETH_P_IP, ip_buffer);
        DEBUG_IP("BYTES(%d)\n", bytes);

	if (bytes == 0)
		return 0;

	if (ip->ip_ver != 4 || ip->ip_ihl < 5) {
		DEBUG_IP("ERROR: IP version(%d)/length(%d)\n",ip->ip_ver, ip->ip_ihl);
		return 0;
	}

	hdrlen = ip->ip_ihl * 4;

	if ( (check=checksum(ip, hdrlen, 0)) != 0xffff) {
		DEBUG_IP("ERROR:IP checksum(0x%x)\n",check);
		return 0;
	}

	if (ip->ip_proto != protocol) {
		DEBUG_IP("ERROR:protocol(%x)\n",ip->ip_proto);
		return 0;
	}

	if (from != INADDR_ANY && from != ip->ip_source) {
		DEBUG_IP("ERROR:Src addr(%x)\n", from);
		return 0;
	}

	if (to != INADDR_ANY && to != ip->ip_dest) {
		DEBUG_IP("ERROR:dest addr(%x)\n", to);
		return 0;
	}

	bytes -= hdrlen;

	memcpy(buffer, ip_buffer + hdrlen, bytes);

	return bytes;
}