net.c

{
	return !((NetCksum(ptr, len) + 1) & 0xfffe);
}


unsigned
NetCksum(uchar * ptr, int len)
{
	ulong	xsum;

	xsum = 0;
	while (len-- > 0)
		xsum += *((ushort *)ptr)++;
	xsum = (xsum & 0xffff) + (xsum >> 16);
	xsum = (xsum & 0xffff) + (xsum >> 16);
	return (xsum & 0xffff);
}


void
NetSetEther(volatile uchar * xet, uchar * addr, uint prot)
{
	Ethernet_t *et = (Ethernet_t *)xet;

	memcpy (et->et_dest, addr, 6);
	memcpy (et->et_src, NetOurEther, 6);
	et->et_protlen = htons(prot);
}


void
NetSetIP(volatile uchar * xip, IPaddr_t dest, int dport, int sport, int len)
{
	volatile IP_t *ip = (IP_t *)xip;

	/*
	 *	If the data is an odd number of bytes, zero the
	 *	byte after the last byte so that the checksum
	 *	will work.
	 */
	if (len & 1)
		xip[IP_HDR_SIZE + len] = 0;

	/*
	 *	Construct an IP and UDP header.
			(need to set no fragment bit - XXX)
	 */
	ip->ip_hl_v  = 0x45;		/* IP_HDR_SIZE / 4 (not including UDP) */
	ip->ip_tos   = 0;
	ip->ip_len   = htons(IP_HDR_SIZE + len);
	ip->ip_id    = htons(NetIPID++);
	ip->ip_off   = htons(0x4000);	/* No fragmentation */
	ip->ip_ttl   = 255;
	ip->ip_p     = 17;		/* UDP */
	ip->ip_sum   = 0;
	NetCopyIP((void*)&ip->ip_src, &NetOurIP); /* already in network byte order */
	NetCopyIP((void*)&ip->ip_dst, &dest);	   /* - "" - */
	ip->udp_src  = htons(sport);
	ip->udp_dst  = htons(dport);
	ip->udp_len  = htons(8 + len);
	ip->udp_xsum = 0;
	ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2);
}

void copy_filename (uchar *dst, uchar *src, int size)
{
	if (*src && (*src == '"')) {
		++src;
		--size;
	}

	while ((--size > 0) && *src && (*src != '"')) {
		*dst++ = *src++;
	}
	*dst = '\0';
}

#endif /* CFG_CMD_NET */

void ip_to_string (IPaddr_t x, char *s)
{
    x = ntohl(x);
    sprintf (s,"%d.%d.%d.%d",
	(int)((x >> 24) & 0xff),
	(int)((x >> 16) & 0xff),
	(int)((x >>  8) & 0xff),
	(int)((x >>  0) & 0xff)
    );
}

IPaddr_t string_to_ip(char *s)
{
	IPaddr_t addr;
	char *e;
	int i;

	if (s == NULL)
		return(0);

	for (addr=0, i=0; i<4; ++i) {
		ulong val = s ? simple_strtoul(s, &e, 10) : 0;
		addr <<= 8;
		addr |= (val & 0xFF);
		if (s) {
			s = (*e) ? e+1 : e;
		}
	}

	return (htonl(addr));
}

void print_IPaddr (IPaddr_t x)
{
    char tmp[16];

    ip_to_string(x, tmp);

    puts(tmp);
}

IPaddr_t getenv_IPaddr (char *var)
{
	return (string_to_ip(getenv(var)));
}