net.c

使用Linux ARM GCC编译器来编译

	/* if MAC address was not discovered yet, save the packet and do an ARP request */
	if (memcmp(ether, NetEtherNullAddr, 6) == 0) {

#ifdef ET_DEBUG
		printk("sending ARP for %08lx\n", dest);
#endif
		NetArpWaitPacketIP = dest;
		NetArpWaitPacketMAC = ether;

		pkt = NetArpWaitTxPacket;
		pkt += NetSetEther (pkt, NetArpWaitPacketMAC, PROT_IP);

		NetSetIP (pkt, dest, dport, sport, len);
		memcpy(pkt + IP_HDR_SIZE, (uchar *)NetTxPacket + (pkt - (uchar *)NetArpWaitTxPacket) + IP_HDR_SIZE, len);

		/* size of the waiting packet */
		NetArpWaitTxPacketSize = (pkt - NetArpWaitTxPacket) + IP_HDR_SIZE + len;

		/* and do the ARP request */
		NetArpWaitTry = 1;
		NetArpWaitTimerStart = get_timer(0);
		ArpRequest();
		return 1;	/* waiting */
	}

#ifdef ET_DEBUG
	printk("sending UDP to %08lx/%02x:%02x:%02x:%02x:%02x:%02x\n",
		dest, ether[0], ether[1], ether[2], ether[3], ether[4], ether[5]);
#endif

	pkt = (uchar *)NetTxPacket;
	pkt += NetSetEther (pkt, ether, PROT_IP);
	NetSetIP (pkt, dest, dport, sport, len);
	(void) eth_send(NetTxPacket, (pkt - NetTxPacket) + IP_HDR_SIZE + len);

	return 0;	/* transmitted */
}

#ifdef CONFIG_NET_PING
static ushort PingSeqNo;

int PingSend(void)
{
	static uchar mac[6];
	volatile IP_t *ip;
	volatile ushort *s;
	uchar *pkt;

	/* XXX always send arp request */

	memcpy(mac, NetEtherNullAddr, 6);

#ifdef ET_DEBUG
	printk("sending ARP for %d.%d.%d.%d\n", (NetPingIP>>0)&0xff,(NetPingIP>>8)&0xff,(NetPingIP>>16)&0xff,(NetPingIP>>24)&0xff);
#endif

	NetArpWaitPacketIP = NetPingIP;
	NetArpWaitPacketMAC = mac;

	pkt = NetArpWaitTxPacket;
	pkt += NetSetEther(pkt, mac, PROT_IP);

	ip = (volatile IP_t *)pkt;

	/*
	 *	Construct an IP and ICMP 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_NO_UDP + 8);
	ip->ip_id    = htons(NetIPID++);
	ip->ip_off   = htons(0x4000);	/* No fragmentation */
	ip->ip_ttl   = 255;
	ip->ip_p     = IPPROTO_ICMP;		/* ICMP */
	ip->ip_sum   = 0;
	NetCopyIP((void*)&ip->ip_src, &NetOurIP); /* already in network byte order */
	NetCopyIP((void*)&ip->ip_dst, &NetPingIP);	   /* - "" - */
	ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2);

	s = &ip->udp_src;		/* XXX ICMP starts here */
	s[0] = htons(0x0800);		/* echo-request, code */
	s[1] = 0;			/* checksum */
	s[2] = 0; 			/* identifier */
	s[3] = htons(PingSeqNo++);	/* sequence number */
	s[1] = ~NetCksum((uchar *)s, 8/2);

	/* size of the waiting packet */
	NetArpWaitTxPacketSize = (pkt - NetArpWaitTxPacket) + IP_HDR_SIZE_NO_UDP + 8;

	/* and do the ARP request */
	NetArpWaitTry = 1;
	NetArpWaitTimerStart = get_timer(0);
	ArpRequest();
	return 1;	/* waiting */
}

static void
PingTimeout (void)
{
	eth_halt();
	NetState = NETLOOP_FAIL;	/* we did not get the reply */
}

static void
PingHandler (uchar * pkt, unsigned dest, unsigned src, unsigned len)
{
	IPaddr_t tmp;
	volatile IP_t *ip = (volatile IP_t *)pkt;

	tmp = NetReadIP((void *)&ip->ip_src);
	printk ("Get ICMP ECHO REPLY from ");
	print_IPaddr(tmp);
	printk ("\n");
	if (tmp != NetPingIP)
		return;

	NetState = NETLOOP_SUCCESS;
}

static void PingStart(void)
{
#if defined(CONFIG_NET_MULTI)
	printk ("Using %s device\n", eth_get_name());
#endif	/* CONFIG_NET_MULTI */
	NetSetTimeout (10 * CFG_HZ, PingTimeout);
	NetSetHandler (PingHandler);

	PingSend();
}
#endif	/* CFG_CMD_PING */


void
NetReceive(volatile uchar * inpkt, int len)
{
	Ethernet_t *et;
	IP_t	*ip;
	ARP_t	*arp;
	IPaddr_t tmp;
	int	x;
	uchar *pkt;
	//ushort cti = 0;

#ifdef ET_DEBUG
	printk("packet received\n");
#endif

	NetRxPkt = inpkt;
	NetRxPktLen = len;
	et = (Ethernet_t *)inpkt;

	/* too small packet? */
	if (len < ETHER_HDR_SIZE)
		return;

	x = ntohs(et->et_protlen);

#ifdef ET_DEBUG
	printk("packet received\n");
#endif

	if (x < 1514) {
		/*
		 *	Got a 802 packet.  Check the other protocol field.
		 */
		x = ntohs(et->et_prot);

		ip = (IP_t *)(inpkt + E802_HDR_SIZE);
		len -= E802_HDR_SIZE;

	} else {	/* normal packet */
		ip = (IP_t *)(inpkt + ETHER_HDR_SIZE);
		len -= ETHER_HDR_SIZE;

	}

#ifdef ET_DEBUG
	printk("Receive from protocol 0x%x\n", x);
#endif

	switch (x) {

	case PROT_ARP:
		/*
		 * We have to deal with two types of ARP packets:
		 * - REQUEST packets will be answered by sending  our
		 *   IP address - if we know it.
		 * - REPLY packates are expected only after we asked
		 *   for the TFTP server's or the gateway's ethernet
		 *   address; so if we receive such a packet, we set
		 *   the server ethernet address
		 */
#ifdef ET_DEBUG
		putstr ("Got ARP\n");
#endif
		arp = (ARP_t *)ip;
		if (len < ARP_HDR_SIZE) {
			printk("bad length %d < %d\n", len, ARP_HDR_SIZE);
			return;
		}
		if ((ntohs(arp->ar_hrd) != ARP_ETHER)||(ntohs(arp->ar_pro) != PROT_IP)) {
			return;
		}
		if ((arp->ar_hln != 6)||(arp->ar_pln != 4)) {
			return;
		}

		if (NetOurIP == 0) {
			return;
		}

		if (NetReadIP(arp->ar_tpa) != NetOurIP) {
			return;
		}

		switch (ntohs(arp->ar_op)) {
		case ARPOP_REQUEST:		/* reply with our IP address	*/
#ifdef ET_DEBUG
			putstr ("Got ARP REQUEST, return our IP\n");
#endif
			pkt = (uchar *)et;
			pkt += NetSetEther(pkt, et->et_src, PROT_ARP);
			arp->ar_op = htons(ARPOP_REPLY);
			memcpy   (arp->ar_tha, arp->ar_sha, 6);
			NetCopyIP(arp->ar_tpa, arp->ar_spa);
			memcpy   (arp->ar_sha, NetOurEther, 6);
			NetCopyIP(arp->ar_spa, &NetOurIP);
			(void) eth_send((uchar *)et, (pkt - (uchar *)et) + ARP_HDR_SIZE);
			return;

		case ARPOP_REPLY:		/* arp reply */
			/* are we waiting for a reply */
			if (!NetArpWaitPacketIP || !NetArpWaitPacketMAC)
				break;
#ifdef ET_DEBUG
			printk("Got ARP REPLY, set server/gtwy eth addr (%02x:%02x:%02x:%02x:%02x:%02x)\n",
				arp->ar_sha[0], arp->ar_sha[1],
				arp->ar_sha[2], arp->ar_sha[3],
				arp->ar_sha[4], arp->ar_sha[5]);
#endif

			tmp = NetReadIP(arp->ar_spa);

			/* matched waiting packet's address */
			if (tmp == NetArpWaitReplyIP) {
#ifdef ET_DEBUG
				putstr ("Got it\n");
#endif
				/* save address for later use */
				memcpy(NetArpWaitPacketMAC, arp->ar_sha, 6);

#ifdef CONFIG_NETCONSOLE
				(*packetHandler)(0,0,0,0);
#endif
				/* modify header, and transmit it */
				memcpy(((Ethernet_t *)NetArpWaitTxPacket)->et_dest, NetArpWaitPacketMAC, 6);
				(void) eth_send(NetArpWaitTxPacket, NetArpWaitTxPacketSize);

				/* no arp request pending now */
				NetArpWaitPacketIP = 0;
				NetArpWaitTxPacketSize = 0;
				NetArpWaitPacketMAC = NULL;

			}
			return;
		default:
#ifdef ET_DEBUG
			printk("Unexpected ARP opcode 0x%x\n", ntohs(arp->ar_op));
#endif
			return;
		}
		break;

	case PROT_RARP:
#ifdef ET_DEBUG
		putstr ("Got RARP\n");
#endif
		arp = (ARP_t *)ip;
		if (len < ARP_HDR_SIZE) {
			printk("bad length %d < %d\n", len, ARP_HDR_SIZE);
			return;
		}

		if ((ntohs(arp->ar_op) != RARPOP_REPLY) ||
			(ntohs(arp->ar_hrd) != ARP_ETHER)   ||
			(ntohs(arp->ar_pro) != PROT_IP)     ||
			(arp->ar_hln != 6) || (arp->ar_pln != 4)) {

			putstr ("invalid RARP header\n");
		} else {
			NetCopyIP(&NetOurIP,    arp->ar_tpa);
			if (NetServerIP == 0)
				NetCopyIP(&NetServerIP, arp->ar_spa);
			memcpy (NetServerEther, arp->ar_sha, 6);

			(*packetHandler)(0,0,0,0);
		}
		break;

	case PROT_IP:
#ifdef ET_DEBUG
		putstr ("Got IP\n");
#endif
		if (len < IP_HDR_SIZE) {
			/*debug*/printk ("len bad %d < %d\n", len, IP_HDR_SIZE);
			return;
		}
		if (len < ntohs(ip->ip_len)) {
			printk("len bad %d < %d\n", len, ntohs(ip->ip_len));
			return;
		}
		len = ntohs(ip->ip_len);
#ifdef ET_DEBUG
		printk("len=%d, v=%02x\n", len, ip->ip_hl_v & 0xff);
#endif
		if ((ip->ip_hl_v & 0xf0) != 0x40) {
			return;
		}
		if (ip->ip_off & htons(0x1fff)) { /* Can't deal w/ fragments */
			return;
		}
		if (!NetCksumOk((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2)) {
			putstr ("checksum bad\n");
			return;
		}
		tmp = NetReadIP(&ip->ip_dst);
		if (NetOurIP && tmp != NetOurIP && tmp != 0xFFFFFFFF) {
			return;
		}
		/*
		 * watch for ICMP host redirects
		 *
		 * There is no real handler code (yet). We just watch
		 * for ICMP host redirect messages. In case anybody
		 * sees these messages: please contact me
		 * ([e-mail]), or - even better - send me the
		 * necessary fixes :-)
		 *
		 * Note: in all cases where I have seen this so far
		 * it was a problem with the router configuration,
		 * for instance when a router was configured in the
		 * BOOTP reply, but the TFTP server was on the same
		 * subnet. So this is probably a warning that your
		 * configuration might be wrong. But I'm not really
		 * sure if there aren't any other situations.
		 */
		if (ip->ip_p == IPPROTO_ICMP) {
			ICMP_t *icmph = (ICMP_t *)&(ip->udp_src);

			switch (icmph->type) {
			case ICMP_REDIRECT:
				if (icmph->code != ICMP_REDIR_HOST)
					return;
				putstr (" ICMP Host Redirect to ");
				print_IPaddr(icmph->un.gateway);
				putc(' ');
				return;
#ifdef CONFIG_NET_PING
			case ICMP_ECHO_REPLY:
				/*
				 *	IP header OK.  Pass the packet to the current handler.
				 */
				/* XXX point to ip packet */
				(*packetHandler)((uchar *)ip, 0, 0, 0);
				return;
#endif
			default:
				return;
			}
		} else if (ip->ip_p != IPPROTO_UDP) {	/* Only UDP packets */
			return;
		}

#ifdef CONFIG_UDP_CHECKSUM
		if (ip->udp_xsum != 0) {
			ulong   xsum;
			ushort *sumptr;
			ushort  sumlen;

			xsum  = ip->ip_p;
			xsum += (ntohs(ip->udp_len));
			xsum += (ntohl(ip->ip_src) >> 16) & 0x0000ffff;
			xsum += (ntohl(ip->ip_src) >>  0) & 0x0000ffff;
			xsum += (ntohl(ip->ip_dst) >> 16) & 0x0000ffff;
			xsum += (ntohl(ip->ip_dst) >>  0) & 0x0000ffff;

			sumlen = ntohs(ip->udp_len);
			sumptr = (ushort *) &(ip->udp_src);

			while (sumlen > 1) {
				ushort sumdata;

				sumdata = *sumptr++;
				xsum += ntohs(sumdata);
				sumlen -= 2;
			}
			if (sumlen > 0) {
				ushort sumdata;

				sumdata = *(unsigned char *) sumptr;
				sumdata = (sumdata << 8) & 0xff00;
				xsum += sumdata;
			}
			while ((xsum >> 16) != 0) {
				xsum = (xsum & 0x0000ffff) + ((xsum >> 16) & 0x0000ffff);
			}
			if ((xsum != 0x00000000) && (xsum != 0x0000ffff)) {
				printk(" UDP wrong checksum %08x %08x\n", xsum, ntohs(ip->udp_xsum));
				return;
			}
		}
#endif

#ifdef CONFIG_NETCONSOLE
		nc_input_packet((uchar *)ip +IP_HDR_SIZE,
						ntohs(ip->udp_dst),
						ntohs(ip->udp_src),
						ntohs(ip->udp_len) - 8);
#endif
		/*
		 *	IP header OK.  Pass the packet to the current handler.
		 */
		(*packetHandler)((uchar *)ip +IP_HDR_SIZE,
						ntohs(ip->udp_dst),
						ntohs(ip->udp_src),
						ntohs(ip->udp_len) - 8);
		break;
	}
}


/**********************************************************************/

static int net_check_prereq (proto_t protocol)
{
	switch (protocol) {
		/* Fall through */
#ifdef CONFIG_NET_PING
	case PING:
		if (NetPingIP == 0) {
			putstr ("*** ERROR: ping address not given\n");
			return (1);
		}
		goto common;
#endif
#ifdef CONFIG_NET_SNTP
	case SNTP:
		if (NetNtpServerIP == 0) {
			putstr ("*** ERROR: NTP server address not given\n");
			return (1);
		}
		goto common;
#endif
#ifdef CONFIG_NET_NFS
	case NFS:
#endif
	case NETCONS:
	case TFTP:
		if (NetServerIP == 0) {
			putstr ("*** ERROR: `serverip' not set\n");
			return (1);
		}
#if defined(CONFIG_NET_PING) | defined(CONFIG_NET_SNTP)
    common:
#endif

		if (NetOurIP == 0) {
			putstr ("*** ERROR: `ipaddr' not set\n");
			return (1);
		}
		/* Fall through */

	case DHCP:
	case RARP:
	case BOOTP:
	//case CDP:
		if (memcmp (NetOurEther, "\0\0\0\0\0\0", 6) == 0) {
#ifdef CONFIG_NET_MULTI
			extern int eth_get_dev_index (void);
			int num = eth_get_dev_index ();

			switch (num) {
			case -1:
				putstr ("*** ERROR: No ethernet found.\n");
				return (1);
			case 0:
				putstr ("*** ERROR: `ethaddr' not set\n");
				break;
			default:
				printk ("*** ERROR: `eth%daddr' not set\n",
					num);
				break;
			}

			NetStartAgain ();
			return (2);
#else
			putstr ("*** ERROR: `ethaddr' not set\n");
			return (1);
#endif
		}
		/* Fall through */
	default:
		//return (0);
	}
	return (0);		/* OK */
}
/**********************************************************************/

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


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

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

int
NetEthHdrSize(void)
{
	return ETHER_HDR_SIZE;
}

int
NetSetEther(volatile uchar * xet, const 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);
	
	return ETHER_HDR_SIZE;
}

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';
}

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;
		}
		if (*e != '.') break;
	}

	return (htonl(addr));
}

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

	ip_to_string (x, tmp);

	printk (tmp);
}

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

#endif /* CONFIG_NETWORK */