text: /*
   *	Copied from Linux Monitor (LiMon) - Networking.
   *
   *	Copyright 1994 - 2000 Neil Russell.
   *	(See License)
   *	Copyright 2000 Roland Borde
   *	Copyright 2000 Paolo Scaffardi
   *	Copyright 2000-2002 Wolfgang Denk, wd@denx.de
   */
  
  /*
   * General Desription:
   *
   * The user interface supports commands for BOOTP, RARP, and TFTP.
   * Also, we support ARP internally. Depending on available data,
   * these interact as follows:
   *
   * BOOTP:
   *
   *	Prerequisites:	- own ethernet address
   *	We want:	- own IP address
   *			- TFTP server IP address
   *			- name of bootfile
   *	Next step:	ARP
   *
   * RARP:
   *
   *	Prerequisites:	- own ethernet address
   *	We want:	- own IP address
   *			- TFTP server IP address
   *	Next step:	ARP
   *
   * ARP:
   *
   *	Prerequisites:	- own ethernet address
   *			- own IP address
   *			- TFTP server IP address
   *	We want:	- TFTP server ethernet address
   *	Next step:	TFTP
   *
   * DHCP:
   *
   *     Prerequisites:	- own ethernet address
   *     We want:		- IP, Netmask, ServerIP, Gateway IP
   *			- bootfilename, lease time
   *     Next step:	- TFTP
   *
   * TFTP:
   *
   *	Prerequisites:	- own ethernet address
   *			- own IP address
   *			- TFTP server IP address
   *			- TFTP server ethernet address
   *			- name of bootfile (if unknown, we use a default name
   *			  derived from our own IP address)
   *	We want:	- load the boot file
   *	Next step:	none
   *
   * NFS:
   *
   *	Prerequisites:	- own ethernet address
   *			- own IP address
   *			- name of bootfile (if unknown, we use a default name
   *			  derived from our own IP address)
   *	We want:	- load the boot file
   *	Next step:	none
   *
   * SNTP:
   *
   *	Prerequisites:	- own ethernet address
   *			- own IP address
   *	We want:	- network time
   *	Next step:	none
   */
  
  
  #include <common.h>
  #include <watchdog.h>
  #include <command.h>
  #include <net.h>
  #include "bootp.h"
  #include "tftp.h"
  #include "rarp.h"
  #include "nfs.h"
  #ifdef CONFIG_STATUS_LED
  #include <status_led.h>
  #include <miiphy.h>
  #endif
  #if defined(CONFIG_CMD_SNTP)
  #include "sntp.h"
  #endif
  #if defined(CONFIG_CDP_VERSION)
  #include <timestamp.h>
  #endif
  #if defined(CONFIG_CMD_DNS)
  #include "dns.h"
  #endif
  
  #if defined(CONFIG_CMD_NET)
  
  DECLARE_GLOBAL_DATA_PTR;
  
  #ifndef	CONFIG_ARP_TIMEOUT
  # define ARP_TIMEOUT		5000UL	/* Milliseconds before trying ARP again */
  #else
  # define ARP_TIMEOUT		CONFIG_ARP_TIMEOUT
  #endif
  
  
  #ifndef	CONFIG_NET_RETRY_COUNT
  # define ARP_TIMEOUT_COUNT	5	/* # of timeouts before giving up  */
  #else
  # define ARP_TIMEOUT_COUNT	CONFIG_NET_RETRY_COUNT
  #endif
  
  /** BOOTP EXTENTIONS **/
  
  IPaddr_t	NetOurSubnetMask=0;		/* Our subnet mask (0=unknown)	*/
  IPaddr_t	NetOurGatewayIP=0;		/* Our gateways IP address	*/
  IPaddr_t	NetOurDNSIP=0;			/* Our DNS IP address		*/
  #if defined(CONFIG_BOOTP_DNS2)
  IPaddr_t	NetOurDNS2IP=0;			/* Our 2nd DNS IP address	*/
  #endif
  char		NetOurNISDomain[32]={0,};	/* Our NIS domain		*/
  char		NetOurHostName[32]={0,};	/* Our hostname			*/
  char		NetOurRootPath[64]={0,};	/* Our bootpath			*/
  ushort		NetBootFileSize=0;		/* Our bootfile size in blocks	*/
  
  #ifdef CONFIG_MCAST_TFTP	/* Multicast TFTP */
  IPaddr_t Mcast_addr;
  #endif
  
  /** END OF BOOTP EXTENTIONS **/
  
  ulong		NetBootFileXferSize;	/* The actual transferred size of the bootfile (in bytes) */
  uchar		NetOurEther[6];		/* Our ethernet address			*/
  uchar		NetServerEther[6] =	/* Boot server enet address		*/
  			{ 0, 0, 0, 0, 0, 0 };
  IPaddr_t	NetOurIP;		/* Our IP addr (0 = unknown)		*/
  IPaddr_t	NetServerIP;		/* Server IP addr (0 = unknown)		*/
  volatile uchar *NetRxPacket;		/* Current receive packet		*/
  int		NetRxPacketLen;		/* Current rx packet length		*/
  unsigned	NetIPID;		/* IP packet ID				*/
  uchar		NetBcastAddr[6] =	/* Ethernet bcast address		*/
  			{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
  uchar		NetEtherNullAddr[6] =
  			{ 0, 0, 0, 0, 0, 0 };
  #ifdef CONFIG_API
  void		(*push_packet)(volatile void *, int len) = 0;
  #endif
  #if defined(CONFIG_CMD_CDP)
  uchar		NetCDPAddr[6] =		/* Ethernet bcast address		*/
  			{ 0x01, 0x00, 0x0c, 0xcc, 0xcc, 0xcc };
  #endif
  int		NetState;		/* Network loop state			*/
  #ifdef CONFIG_NET_MULTI
  int		NetRestartWrap = 0;	/* Tried all network devices		*/
  static int	NetRestarted = 0;	/* Network loop restarted		*/
  static int	NetDevExists = 0;	/* At least one device configured	*/
  #endif
  
  /* XXX in both little & big endian machines 0xFFFF == ntohs(-1) */
  ushort		NetOurVLAN = 0xFFFF;		/* default is without VLAN	*/
  ushort		NetOurNativeVLAN = 0xFFFF;	/* ditto			*/
  
  char		BootFile[128];		/* Boot File name			*/
  
  #if defined(CONFIG_CMD_PING)
  IPaddr_t	NetPingIP;		/* the ip address to ping		*/
  
  static void PingStart(void);
  #endif
  
  #if defined(CONFIG_CMD_CDP)
  static void CDPStart(void);
  #endif
  
  #if defined(CONFIG_CMD_SNTP)
  IPaddr_t	NetNtpServerIP;		/* NTP server IP address		*/
  int		NetTimeOffset=0;	/* offset time from UTC			*/
  #endif
  
  #ifdef CONFIG_NETCONSOLE
  void NcStart(void);
  int nc_input_packet(uchar *pkt, unsigned dest, unsigned src, unsigned len);
  #endif
  
  volatile uchar	PktBuf[(PKTBUFSRX+1) * PKTSIZE_ALIGN + PKTALIGN];
  
  volatile uchar *NetRxPackets[PKTBUFSRX]; /* Receive packets			*/
  
  static rxhand_f *packetHandler;		/* Current RX packet handler		*/
  static thand_f *timeHandler;		/* Current timeout handler		*/
  static ulong	timeStart;		/* Time base value			*/
  static ulong	timeDelta;		/* Current timeout value		*/
  volatile uchar *NetTxPacket = 0;	/* THE transmit packet			*/
  
  static int net_check_prereq (proto_t protocol);
  
  /**********************************************************************/
  
  IPaddr_t	NetArpWaitPacketIP;
  IPaddr_t	NetArpWaitReplyIP;
  uchar	       *NetArpWaitPacketMAC;	/* MAC address of waiting packet's destination	*/
  uchar	       *NetArpWaitTxPacket;	/* THE transmit packet			*/
  int		NetArpWaitTxPacketSize;
  uchar		NetArpWaitPacketBuf[PKTSIZE_ALIGN + PKTALIGN];
  ulong		NetArpWaitTimerStart;
  int		NetArpWaitTry;
  
  void ArpRequest (void)
  {
  	int i;
  	volatile uchar *pkt;
  	ARP_t *arp;
  
  	debug("ARP broadcast %d\n", NetArpWaitTry);
  
  	pkt = NetTxPacket;
  
  	pkt += NetSetEther (pkt, NetBcastAddr, PROT_ARP);
  
  	arp = (ARP_t *) pkt;
  
  	arp->ar_hrd = htons (ARP_ETHER);
  	arp->ar_pro = htons (PROT_IP);
  	arp->ar_hln = 6;
  	arp->ar_pln = 4;
  	arp->ar_op = htons (ARPOP_REQUEST);
  
  	memcpy (&arp->ar_data[0], NetOurEther, 6);		/* source ET addr	*/
  	NetWriteIP ((uchar *) & arp->ar_data[6], NetOurIP);	/* source IP addr	*/
  	for (i = 10; i < 16; ++i) {
  		arp->ar_data[i] = 0;				/* dest ET addr = 0     */
  	}
  
  	if ((NetArpWaitPacketIP & NetOurSubnetMask) !=
  	    (NetOurIP & NetOurSubnetMask)) {
  		if (NetOurGatewayIP == 0) {
  			puts ("## Warning: gatewayip needed but not set\n");
  			NetArpWaitReplyIP = NetArpWaitPacketIP;
  		} else {
  			NetArpWaitReplyIP = NetOurGatewayIP;
  		}
  	} else {
  		NetArpWaitReplyIP = NetArpWaitPacketIP;
  	}
  
  	NetWriteIP ((uchar *) & arp->ar_data[16], NetArpWaitReplyIP);
  	(void) eth_send (NetTxPacket, (pkt - NetTxPacket) + ARP_HDR_SIZE);
  }
  
  void ArpTimeoutCheck(void)
  {
  	ulong t;
  
  	if (!NetArpWaitPacketIP)
  		return;
  
  	t = get_timer(0);
  
  	/* check for arp timeout */
  	if ((t - NetArpWaitTimerStart) > ARP_TIMEOUT) {
  		NetArpWaitTry++;
  
  		if (NetArpWaitTry >= ARP_TIMEOUT_COUNT) {
  			puts ("\nARP Retry count exceeded; starting again\n");
  			NetArpWaitTry = 0;
  			NetStartAgain();
  		} else {
  			NetArpWaitTimerStart = t;
  			ArpRequest();
  		}
  	}
  }
  
  static void
  NetInitLoop(proto_t protocol)
  {
  	static int env_changed_id = 0;
  	bd_t *bd = gd->bd;
  	int env_id = get_env_id ();
  
  	/* update only when the environment has changed */
  	if (env_changed_id != env_id) {
  		NetCopyIP(&NetOurIP, &bd->bi_ip_addr);
  		NetOurGatewayIP = getenv_IPaddr ("gatewayip");
  		NetOurSubnetMask= getenv_IPaddr ("netmask");
  		NetServerIP = getenv_IPaddr ("serverip");
  		NetOurNativeVLAN = getenv_VLAN("nvlan");
  		NetOurVLAN = getenv_VLAN("vlan");
  #if defined(CONFIG_CMD_DNS)
  		NetOurDNSIP = getenv_IPaddr("dnsip");
  #endif
  		env_changed_id = env_id;
  	}
  
  	return;
  }
  
  /**********************************************************************/
  /*
   *	Main network processing loop.
   */
  
  int
  NetLoop(proto_t protocol)
  {
  	bd_t *bd = gd->bd;
  
  #ifdef CONFIG_NET_MULTI
  	NetRestarted = 0;
  	NetDevExists = 0;
  #endif
  
  	/* XXX problem with bss workaround */
  	NetArpWaitPacketMAC = NULL;
  	NetArpWaitTxPacket = NULL;
  	NetArpWaitPacketIP = 0;
  	NetArpWaitReplyIP = 0;
  	NetArpWaitTxPacket = NULL;
  	NetTxPacket = NULL;
  
  	if (!NetTxPacket) {
  		int	i;
  		/*
  		 *	Setup packet buffers, aligned correctly.
  		 */
  		NetTxPacket = &PktBuf[0] + (PKTALIGN - 1);
  		NetTxPacket -= (ulong)NetTxPacket % PKTALIGN;
  		for (i = 0; i < PKTBUFSRX; i++) {
  			NetRxPackets[i] = NetTxPacket + (i+1)*PKTSIZE_ALIGN;
  		}
  	}
  
  	if (!NetArpWaitTxPacket) {
  		NetArpWaitTxPacket = &NetArpWaitPacketBuf[0] + (PKTALIGN - 1);
  		NetArpWaitTxPacket -= (ulong)NetArpWaitTxPacket % PKTALIGN;
  		NetArpWaitTxPacketSize = 0;
  	}
  
  	eth_halt();
  #ifdef CONFIG_NET_MULTI
  	eth_set_current();
  #endif
  	if (eth_init(bd) < 0) {
  		eth_halt();
  		return(-1);
  	}
  
  restart:
  #ifdef CONFIG_NET_MULTI
  	memcpy (NetOurEther, eth_get_dev()->enetaddr, 6);
  #else
  	eth_getenv_enetaddr("ethaddr", NetOurEther);
  #endif
  
  	NetState = NETLOOP_CONTINUE;
  
  	/*
  	 *	Start the ball rolling with the given start function.  From
  	 *	here on, this code is a state machine driven by received
  	 *	packets and timer events.
  	 */
  	NetInitLoop(protocol);
  
  	switch (net_check_prereq (protocol)) {
  	case 1:
  		/* network not configured */
  		eth_halt();
  		return (-1);
  
  #ifdef CONFIG_NET_MULTI
  	case 2:
  		/* network device not configured */
  		break;
  #endif /* CONFIG_NET_MULTI */
  
  	case 0:
  #ifdef CONFIG_NET_MULTI
  		NetDevExists = 1;
  #endif
  		switch (protocol) {
  		case TFTP:
  			/* always use ARP to get server ethernet address */
  			TftpStart();
  			break;
  
  #if defined(CONFIG_CMD_DHCP)
  		case DHCP:
  			BootpTry = 0;
  			NetOurIP = 0;
  			DhcpRequest();		/* Basically same as BOOTP */
  			break;
  #endif
  
  		case BOOTP:
  			BootpTry = 0;
  			NetOurIP = 0;
  			BootpRequest ();
  			break;
  
  		case RARP:
  			RarpTry = 0;
  			NetOurIP = 0;
  			RarpRequest ();
  			break;
  #if defined(CONFIG_CMD_PING)
  		case PING:
  			PingStart();
  			break;
  #endif
  #if defined(CONFIG_CMD_NFS)
  		case NFS:
  			NfsStart();
  			break;
  #endif
  #if defined(CONFIG_CMD_CDP)
  		case CDP:
  			CDPStart();
  			break;
  #endif
  #ifdef CONFIG_NETCONSOLE
  		case NETCONS:
  			NcStart();
  			break;
  #endif
  #if defined(CONFIG_CMD_SNTP)
  		case SNTP:
  			SntpStart();
  			break;
  #endif
  #if defined(CONFIG_CMD_DNS)
  		case DNS:
  			DnsStart();
  			break;
  #endif
  		default:
  			break;
  		}
  
  		NetBootFileXferSize = 0;
  		break;
  	}
  
  #if defined(CONFIG_MII) || defined(CONFIG_CMD_MII)
  #if defined(CONFIG_SYS_FAULT_ECHO_LINK_DOWN) && defined(CONFIG_STATUS_LED) && defined(STATUS_LED_RED)
  	/*
  	 * Echo the inverted link state to the fault LED.
  	 */
  	if(miiphy_link(eth_get_dev()->name, CONFIG_SYS_FAULT_MII_ADDR)) {
  		status_led_set (STATUS_LED_RED, STATUS_LED_OFF);
  	} else {
  		status_led_set (STATUS_LED_RED, STATUS_LED_ON);
  	}
  #endif /* CONFIG_SYS_FAULT_ECHO_LINK_DOWN, ... */
  #endif /* CONFIG_MII, ... */
  
  	/*
  	 *	Main packet reception loop.  Loop receiving packets until
  	 *	someone sets `NetState' to a state that terminates.
  	 */
  	for (;;) {
  		WATCHDOG_RESET();
  #ifdef CONFIG_SHOW_ACTIVITY
  		{
  			extern void show_activity(int arg);
  			show_activity(1);
  		}
  #endif
  		/*
  		 *	Check the ethernet for a new packet.  The ethernet
  		 *	receive routine will process it.
  		 */
  		eth_rx();
  
  		/*
  		 *	Abort if ctrl-c was pressed.
  		 */
  		if (ctrlc()) {
  			eth_halt();
  			puts ("\nAbort\n");
  			return (-1);
  		}
  
  		ArpTimeoutCheck();
  
  		/*
  		 *	Check for a timeout, and run the timeout handler
  		 *	if we have one.
  		 */
  		if (timeHandler && ((get_timer(0) - timeStart) > timeDelta)) {
  			thand_f *x;
  
  #if defined(CONFIG_MII) || defined(CONFIG_CMD_MII)
  #  if defined(CONFIG_SYS_FAULT_ECHO_LINK_DOWN) && \
        defined(CONFIG_STATUS_LED) &&	   \
        defined(STATUS_LED_RED)
  			/*
  			 * Echo the inverted link state to the fault LED.
  			 */
  			if(miiphy_link(eth_get_dev()->name, CONFIG_SYS_FAULT_MII_ADDR)) {
  				status_led_set (STATUS_LED_RED, STATUS_LED_OFF);
  			} else {
  				status_led_set (STATUS_LED_RED, STATUS_LED_ON);
  			}
  #  endif /* CONFIG_SYS_FAULT_ECHO_LINK_DOWN, ... */
  #endif /* CONFIG_MII, ... */
  			x = timeHandler;
  			timeHandler = (thand_f *)0;
  			(*x)();
  		}
  
  
  		switch (NetState) {
  
  		case NETLOOP_RESTART:
  #ifdef CONFIG_NET_MULTI
  			NetRestarted = 1;
  #endif
  			goto restart;
  
  		case NETLOOP_SUCCESS:
  			if (NetBootFileXferSize > 0) {
  				char buf[20];
  				printf("Bytes transferred = %ld (%lx hex)\n",
  					NetBootFileXferSize,
  					NetBootFileXferSize);
  				sprintf(buf, "%lX", NetBootFileXferSize);
  				setenv("filesize", buf);
  
  				sprintf(buf, "%lX", (unsigned long)load_addr);
  				setenv("fileaddr", buf);
  			}
  			eth_halt();
  			return NetBootFileXferSize;
  
  		case NETLOOP_FAIL:
  			return (-1);
  		}
  	}
  }
  
  /**********************************************************************/
  
  static void
  startAgainTimeout(void)
  {
  	NetState = NETLOOP_RESTART;
  }
  
  static void
  startAgainHandler(uchar * pkt, unsigned dest, unsigned src, unsigned len)
  {
  	/* Totally ignore the packet */
  }
  
  void NetStartAgain (void)
  {
  	char *nretry;
  	int noretry = 0, once = 0;
  
  	if ((nretry = getenv ("netretry")) != NULL) {
  		noretry = (strcmp (nretry, "no") == 0);
  		once = (strcmp (nretry, "once") == 0);
  	}
  	if (noretry) {
  		eth_halt ();
  		NetState = NETLOOP_FAIL;
  		return;
  	}
  #ifndef CONFIG_NET_MULTI
  	NetSetTimeout (10000UL, startAgainTimeout);
  	NetSetHandler (startAgainHandler);
  #else	/* !CONFIG_NET_MULTI*/
  	eth_halt ();
  #if !defined(CONFIG_NET_DO_NOT_TRY_ANOTHER)
  	eth_try_another (!NetRestarted);
  #endif
  	eth_init (gd->bd);
  	if (NetRestartWrap) {
  		NetRestartWrap = 0;
  		if (NetDevExists && !once) {
  			NetSetTimeout (10000UL, startAgainTimeout);
  			NetSetHandler (startAgainHandler);
  		} else {
  			NetState = NETLOOP_FAIL;
  		}
  	} else {
  		NetState = NETLOOP_RESTART;
  	}
  #endif	/* CONFIG_NET_MULTI */
  }
  
  /**********************************************************************/
  /*
   *	Miscelaneous bits.
   */
  
  void
  NetSetHandler(rxhand_f * f)
  {
  	packetHandler = f;
  }
  
  
  void
  NetSetTimeout(ulong iv, thand_f * f)
  {
  	if (iv == 0) {
  		timeHandler = (thand_f *)0;
  	} else {
  		timeHandler = f;
  		timeStart = get_timer(0);
  		timeDelta = iv;
  	}
  }
  
  
  void
  NetSendPacket(volatile uchar * pkt, int len)
  {
  	(void) eth_send(pkt, len);
  }
  
  int
  NetSendUDPPacket(uchar *ether, IPaddr_t dest, int dport, int sport, int len)
  {
  	uchar *pkt;
  
  	/* convert to new style broadcast */
  	if (dest == 0)
  		dest = 0xFFFFFFFF;
  
  	/* if broadcast, make the ether address a broadcast and don't do ARP */
  	if (dest == 0xFFFFFFFF)
  		ether = NetBcastAddr;
  
  	/* if MAC address was not discovered yet, save the packet and do an ARP request */
  	if (memcmp(ether, NetEtherNullAddr, 6) == 0) {
  
  		debug("sending ARP for %08lx\n", dest);
  
  		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 */
  	}
  
  	debug("sending UDP to %08lx/%pM\n", dest, ether);
  
  	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 */
  }
  
  #if defined(CONFIG_CMD_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);
  
  	debug("sending ARP for %08lx\n", NetPingIP);
  
  	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(IP_FLAGS_DFRAG);	/* Don't fragment */
  	ip->ip_ttl   = 255;
  	ip->ip_p     = 0x01;		/* 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);
  	if (tmp != NetPingIP)
  		return;
  
  	NetState = NETLOOP_SUCCESS;
  }
  
  static void PingStart(void)
  {
  #if defined(CONFIG_NET_MULTI)
  	printf ("Using %s device\n", eth_get_name());
  #endif	/* CONFIG_NET_MULTI */
  	NetSetTimeout (10000UL, PingTimeout);
  	NetSetHandler (PingHandler);
  
  	PingSend();
  }
  #endif
  
  #if defined(CONFIG_CMD_CDP)
  
  #define CDP_DEVICE_ID_TLV		0x0001
  #define CDP_ADDRESS_TLV			0x0002
  #define CDP_PORT_ID_TLV			0x0003
  #define CDP_CAPABILITIES_TLV		0x0004
  #define CDP_VERSION_TLV			0x0005
  #define CDP_PLATFORM_TLV		0x0006
  #define CDP_NATIVE_VLAN_TLV		0x000a
  #define CDP_APPLIANCE_VLAN_TLV		0x000e
  #define CDP_TRIGGER_TLV			0x000f
  #define CDP_POWER_CONSUMPTION_TLV	0x0010
  #define CDP_SYSNAME_TLV			0x0014
  #define CDP_SYSOBJECT_TLV		0x0015
  #define CDP_MANAGEMENT_ADDRESS_TLV	0x0016
  
  #define CDP_TIMEOUT			250UL	/* one packet every 250ms */
  
  static int CDPSeq;
  static int CDPOK;
  
  ushort CDPNativeVLAN;
  ushort CDPApplianceVLAN;
  
  static const uchar CDP_SNAP_hdr[8] = { 0xAA, 0xAA, 0x03, 0x00, 0x00, 0x0C, 0x20, 0x00 };
  
  static ushort CDP_compute_csum(const uchar *buff, ushort len)
  {
  	ushort csum;
  	int     odd;
  	ulong   result = 0;
  	ushort  leftover;
  	ushort *p;
  
  	if (len > 0) {
  		odd = 1 & (ulong)buff;
  		if (odd) {
  			result = *buff << 8;
  			len--;
  			buff++;
  		}
  		while (len > 1) {
  			p = (ushort *)buff;
  			result += *p++;
  			buff = (uchar *)p;
  			if (result & 0x80000000)
  				result = (result & 0xFFFF) + (result >> 16);
  			len -= 2;
  		}
  		if (len) {
  			leftover = (signed short)(*(const signed char *)buff);
  			/* CISCO SUCKS big time! (and blows too):
  			 * CDP uses the IP checksum algorithm with a twist;
  			 * for the last byte it *sign* extends and sums.
  			 */
  			result = (result & 0xffff0000) | ((result + leftover) & 0x0000ffff);
  		}
  		while (result >> 16)
  			result = (result & 0xFFFF) + (result >> 16);
  
  		if (odd)
  			result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
  	}
  
  	/* add up 16-bit and 17-bit words for 17+c bits */
  	result = (result & 0xffff) + (result >> 16);
  	/* add up 16-bit and 2-bit for 16+c bit */
  	result = (result & 0xffff) + (result >> 16);
  	/* add up carry.. */
  	result = (result & 0xffff) + (result >> 16);
  
  	/* negate */
  	csum = ~(ushort)result;
  
  	/* run time endian detection */
  	if (csum != htons(csum))	/* little endian */
  		csum = htons(csum);
  
  	return csum;
  }
  
  int CDPSendTrigger(void)
  {
  	volatile uchar *pkt;
  	volatile ushort *s;
  	volatile ushort *cp;
  	Ethernet_t *et;
  	int len;
  	ushort chksum;
  #if defined(CONFIG_CDP_DEVICE_ID) || defined(CONFIG_CDP_PORT_ID)   || \
      defined(CONFIG_CDP_VERSION)   || defined(CONFIG_CDP_PLATFORM)
  	char buf[32];
  #endif
  
  	pkt = NetTxPacket;
  	et = (Ethernet_t *)pkt;
  
  	/* NOTE: trigger sent not on any VLAN */
  
  	/* form ethernet header */
  	memcpy(et->et_dest, NetCDPAddr, 6);
  	memcpy(et->et_src, NetOurEther, 6);
  
  	pkt += ETHER_HDR_SIZE;
  
  	/* SNAP header */
  	memcpy((uchar *)pkt, CDP_SNAP_hdr, sizeof(CDP_SNAP_hdr));
  	pkt += sizeof(CDP_SNAP_hdr);
  
  	/* CDP header */
  	*pkt++ = 0x02;				/* CDP version 2 */
  	*pkt++ = 180;				/* TTL */
  	s = (volatile ushort *)pkt;
  	cp = s;
  	*s++ = htons(0);			/* checksum (0 for later calculation) */
  
  	/* CDP fields */
  #ifdef CONFIG_CDP_DEVICE_ID
  	*s++ = htons(CDP_DEVICE_ID_TLV);
  	*s++ = htons(CONFIG_CDP_DEVICE_ID);
  	sprintf(buf, CONFIG_CDP_DEVICE_ID_PREFIX "%pm", NetOurEther);
  	memcpy((uchar *)s, buf, 16);
  	s += 16 / 2;
  #endif
  
  #ifdef CONFIG_CDP_PORT_ID
  	*s++ = htons(CDP_PORT_ID_TLV);
  	memset(buf, 0, sizeof(buf));
  	sprintf(buf, CONFIG_CDP_PORT_ID, eth_get_dev_index());
  	len = strlen(buf);
  	if (len & 1)	/* make it even */
  		len++;
  	*s++ = htons(len + 4);
  	memcpy((uchar *)s, buf, len);
  	s += len / 2;
  #endif
  
  #ifdef CONFIG_CDP_CAPABILITIES
  	*s++ = htons(CDP_CAPABILITIES_TLV);
  	*s++ = htons(8);
  	*(ulong *)s = htonl(CONFIG_CDP_CAPABILITIES);
  	s += 2;
  #endif
  
  #ifdef CONFIG_CDP_VERSION
  	*s++ = htons(CDP_VERSION_TLV);
  	memset(buf, 0, sizeof(buf));
  	strcpy(buf, CONFIG_CDP_VERSION);
  	len = strlen(buf);
  	if (len & 1)	/* make it even */
  		len++;
  	*s++ = htons(len + 4);
  	memcpy((uchar *)s, buf, len);
  	s += len / 2;
  #endif
  
  #ifdef CONFIG_CDP_PLATFORM
  	*s++ = htons(CDP_PLATFORM_TLV);
  	memset(buf, 0, sizeof(buf));
  	strcpy(buf, CONFIG_CDP_PLATFORM);
  	len = strlen(buf);
  	if (len & 1)	/* make it even */
  		len++;
  	*s++ = htons(len + 4);
  	memcpy((uchar *)s, buf, len);
  	s += len / 2;
  #endif
  
  #ifdef CONFIG_CDP_TRIGGER
  	*s++ = htons(CDP_TRIGGER_TLV);
  	*s++ = htons(8);
  	*(ulong *)s = htonl(CONFIG_CDP_TRIGGER);
  	s += 2;
  #endif
  
  #ifdef CONFIG_CDP_POWER_CONSUMPTION
  	*s++ = htons(CDP_POWER_CONSUMPTION_TLV);
  	*s++ = htons(6);
  	*s++ = htons(CONFIG_CDP_POWER_CONSUMPTION);
  #endif
  
  	/* length of ethernet packet */
  	len = (uchar *)s - ((uchar *)NetTxPacket + ETHER_HDR_SIZE);
  	et->et_protlen = htons(len);
  
  	len = ETHER_HDR_SIZE + sizeof(CDP_SNAP_hdr);
  	chksum = CDP_compute_csum((uchar *)NetTxPacket + len, (uchar *)s - (NetTxPacket + len));
  	if (chksum == 0)
  		chksum = 0xFFFF;
  	*cp = htons(chksum);
  
  	(void) eth_send(NetTxPacket, (uchar *)s - NetTxPacket);
  	return 0;
  }
  
  static void
  CDPTimeout (void)
  {
  	CDPSeq++;
  
  	if (CDPSeq < 3) {
  		NetSetTimeout (CDP_TIMEOUT, CDPTimeout);
  		CDPSendTrigger();
  		return;
  	}
  
  	/* if not OK try again */
  	if (!CDPOK)
  		NetStartAgain();
  	else
  		NetState = NETLOOP_SUCCESS;
  }
  
  static void
  CDPDummyHandler (uchar * pkt, unsigned dest, unsigned src, unsigned len)
  {
  	/* nothing */
  }
  
  static void
  CDPHandler(const uchar * pkt, unsigned len)
  {
  	const uchar *t;
  	const ushort *ss;
  	ushort type, tlen;
  	uchar applid;
  	ushort vlan, nvlan;
  
  	/* minimum size? */
  	if (len < sizeof(CDP_SNAP_hdr) + 4)
  		goto pkt_short;
  
  	/* check for valid CDP SNAP header */
  	if (memcmp(pkt, CDP_SNAP_hdr, sizeof(CDP_SNAP_hdr)) != 0)
  		return;
  
  	pkt += sizeof(CDP_SNAP_hdr);
  	len -= sizeof(CDP_SNAP_hdr);
  
  	/* Version of CDP protocol must be >= 2 and TTL != 0 */
  	if (pkt[0] < 0x02 || pkt[1] == 0)
  		return;
  
  	/* if version is greater than 0x02 maybe we'll have a problem; output a warning */
  	if (pkt[0] != 0x02)
  		printf("** WARNING: CDP packet received with a protocol version %d > 2\n",
  				pkt[0] & 0xff);
  
  	if (CDP_compute_csum(pkt, len) != 0)
  		return;
  
  	pkt += 4;
  	len -= 4;
  
  	vlan = htons(-1);
  	nvlan = htons(-1);
  	while (len > 0) {
  		if (len < 4)
  			goto pkt_short;
  
  		ss = (const ushort *)pkt;
  		type = ntohs(ss[0]);
  		tlen = ntohs(ss[1]);
  		if (tlen > len) {
  			goto pkt_short;
  		}
  
  		pkt += tlen;
  		len -= tlen;
  
  		ss += 2;	/* point ss to the data of the TLV */
  		tlen -= 4;
  
  		switch (type) {
  			case CDP_DEVICE_ID_TLV:
  				break;
  			case CDP_ADDRESS_TLV:
  				break;
  			case CDP_PORT_ID_TLV:
  				break;
  			case CDP_CAPABILITIES_TLV:
  				break;
  			case CDP_VERSION_TLV:
  				break;
  			case CDP_PLATFORM_TLV:
  				break;
  			case CDP_NATIVE_VLAN_TLV:
  				nvlan = *ss;
  				break;
  			case CDP_APPLIANCE_VLAN_TLV:
  				t = (const uchar *)ss;
  				while (tlen > 0) {
  					if (tlen < 3)
  						goto pkt_short;
  
  					applid = t[0];
  					ss = (const ushort *)(t + 1);
  
  #ifdef CONFIG_CDP_APPLIANCE_VLAN_TYPE
  					if (applid == CONFIG_CDP_APPLIANCE_VLAN_TYPE)
  						vlan = *ss;
  #else
  					vlan = ntohs(*ss);	/* XXX will this work; dunno */
  #endif
  					t += 3; tlen -= 3;
  				}
  				break;
  			case CDP_TRIGGER_TLV:
  				break;
  			case CDP_POWER_CONSUMPTION_TLV:
  				break;
  			case CDP_SYSNAME_TLV:
  				break;
  			case CDP_SYSOBJECT_TLV:
  				break;
  			case CDP_MANAGEMENT_ADDRESS_TLV:
  				break;
  		}
  	}
  
  	CDPApplianceVLAN = vlan;
  	CDPNativeVLAN = nvlan;
  
  	CDPOK = 1;
  	return;
  
   pkt_short:
  	printf("** CDP packet is too short\n");
  	return;
  }
  
  static void CDPStart(void)
  {
  #if defined(CONFIG_NET_MULTI)
  	printf ("Using %s device\n", eth_get_name());
  #endif
  	CDPSeq = 0;
  	CDPOK = 0;
  
  	CDPNativeVLAN = htons(-1);
  	CDPApplianceVLAN = htons(-1);
  
  	NetSetTimeout (CDP_TIMEOUT, CDPTimeout);
  	NetSetHandler (CDPDummyHandler);
  
  	CDPSendTrigger();
  }
  #endif
  
  
  void
  NetReceive(volatile uchar * inpkt, int len)
  {
  	Ethernet_t *et;
  	IP_t	*ip;
  	ARP_t	*arp;
  	IPaddr_t tmp;
  	int	x;
  	uchar *pkt;
  #if defined(CONFIG_CMD_CDP)
  	int iscdp;
  #endif
  	ushort cti = 0, vlanid = VLAN_NONE, myvlanid, mynvlanid;
  
  	debug("packet received\n");
  
  	NetRxPacket = inpkt;
  	NetRxPacketLen = len;
  	et = (Ethernet_t *)inpkt;
  
  	/* too small packet? */
  	if (len < ETHER_HDR_SIZE)
  		return;
  
  #ifdef CONFIG_API
  	if (push_packet) {
  		(*push_packet)(inpkt, len);
  		return;
  	}
  #endif
  
  #if defined(CONFIG_CMD_CDP)
  	/* keep track if packet is CDP */
  	iscdp = memcmp(et->et_dest, NetCDPAddr, 6) == 0;
  #endif
  
  	myvlanid = ntohs(NetOurVLAN);
  	if (myvlanid == (ushort)-1)
  		myvlanid = VLAN_NONE;
  	mynvlanid = ntohs(NetOurNativeVLAN);
  	if (mynvlanid == (ushort)-1)
  		mynvlanid = VLAN_NONE;
  
  	x = ntohs(et->et_protlen);
  
  	debug("packet received\n");
  
  	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 if (x != PROT_VLAN) {	/* normal packet */
  		ip = (IP_t *)(inpkt + ETHER_HDR_SIZE);
  		len -= ETHER_HDR_SIZE;
  
  	} else {			/* VLAN packet */
  		VLAN_Ethernet_t *vet = (VLAN_Ethernet_t *)et;
  
  		debug("VLAN packet received\n");
  
  		/* too small packet? */
  		if (len < VLAN_ETHER_HDR_SIZE)
  			return;
  
  		/* if no VLAN active */
  		if ((ntohs(NetOurVLAN) & VLAN_IDMASK) == VLAN_NONE
  #if defined(CONFIG_CMD_CDP)
  				&& iscdp == 0
  #endif
  				)
  			return;
  
  		cti = ntohs(vet->vet_tag);
  		vlanid = cti & VLAN_IDMASK;
  		x = ntohs(vet->vet_type);
  
  		ip = (IP_t *)(inpkt + VLAN_ETHER_HDR_SIZE);
  		len -= VLAN_ETHER_HDR_SIZE;
  	}
  
  	debug("Receive from protocol 0x%x\n", x);
  
  #if defined(CONFIG_CMD_CDP)
  	if (iscdp) {
  		CDPHandler((uchar *)ip, len);
  		return;
  	}
  #endif
  
  	if ((myvlanid & VLAN_IDMASK) != VLAN_NONE) {
  		if (vlanid == VLAN_NONE)
  			vlanid = (mynvlanid & VLAN_IDMASK);
  		/* not matched? */
  		if (vlanid != (myvlanid & VLAN_IDMASK))
  			return;
  	}
  
  	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
  		 */
  		debug("Got ARP\n");
  
  		arp = (ARP_t *)ip;
  		if (len < ARP_HDR_SIZE) {
  			printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
  			return;
  		}
  		if (ntohs(arp->ar_hrd) != ARP_ETHER) {
  			return;
  		}
  		if (ntohs(arp->ar_pro) != PROT_IP) {
  			return;
  		}
  		if (arp->ar_hln != 6) {
  			return;
  		}
  		if (arp->ar_pln != 4) {
  			return;
  		}
  
  		if (NetOurIP == 0) {
  			return;
  		}
  
  		if (NetReadIP(&arp->ar_data[16]) != NetOurIP) {
  			return;
  		}
  
  		switch (ntohs(arp->ar_op)) {
  		case ARPOP_REQUEST:		/* reply with our IP address	*/
  			debug("Got ARP REQUEST, return our IP\n");
  			pkt = (uchar *)et;
  			pkt += NetSetEther(pkt, et->et_src, PROT_ARP);
  			arp->ar_op = htons(ARPOP_REPLY);
  			memcpy   (&arp->ar_data[10], &arp->ar_data[0], 6);
  			NetCopyIP(&arp->ar_data[16], &arp->ar_data[6]);
  			memcpy   (&arp->ar_data[ 0], NetOurEther, 6);
  			NetCopyIP(&arp->ar_data[ 6], &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 CONFIG_KEEP_SERVERADDR
  			if (NetServerIP == NetArpWaitPacketIP) {
  				char buf[20];
  				sprintf(buf, "%pM", arp->ar_data);
  				setenv("serveraddr", buf);
  			}
  #endif
  
  			debug("Got ARP REPLY, set server/gtwy eth addr (%pM)\n",
  				arp->ar_data);
  
  			tmp = NetReadIP(&arp->ar_data[6]);
  
  			/* matched waiting packet's address */
  			if (tmp == NetArpWaitReplyIP) {
  				debug("Got it\n");
  				/* save address for later use */
  				memcpy(NetArpWaitPacketMAC, &arp->ar_data[0], 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:
  			debug("Unexpected ARP opcode 0x%x\n", ntohs(arp->ar_op));
  			return;
  		}
  		break;
  
  	case PROT_RARP:
  		debug("Got RARP\n");
  		arp = (ARP_t *)ip;
  		if (len < ARP_HDR_SIZE) {
  			printf("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)) {
  
  			puts ("invalid RARP header\n");
  		} else {
  			NetCopyIP(&NetOurIP,    &arp->ar_data[16]);
  			if (NetServerIP == 0)
  				NetCopyIP(&NetServerIP, &arp->ar_data[ 6]);
  			memcpy (NetServerEther, &arp->ar_data[ 0], 6);
  
  			(*packetHandler)(0,0,0,0);
  		}
  		break;
  
  	case PROT_IP:
  		debug("Got IP\n");
  		if (len < IP_HDR_SIZE) {
  			debug("len bad %d < %lu\n", len, (ulong)IP_HDR_SIZE);
  			return;
  		}
  		if (len < ntohs(ip->ip_len)) {
  			printf("len bad %d < %d\n", len, ntohs(ip->ip_len));
  			return;
  		}
  		len = ntohs(ip->ip_len);
  		debug("len=%d, v=%02x\n", len, ip->ip_hl_v & 0xff);
  
  		if ((ip->ip_hl_v & 0xf0) != 0x40) {
  			return;
  		}
  		/* Can't deal with fragments */
  		if (ip->ip_off & htons(IP_OFFS | IP_FLAGS_MFRAG)) {
  			return;
  		}
  		/* can't deal with headers > 20 bytes */
  		if ((ip->ip_hl_v & 0x0f) > 0x05) {
  			return;
  		}
  		if (!NetCksumOk((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2)) {
  			puts ("checksum bad\n");
  			return;
  		}
  		tmp = NetReadIP(&ip->ip_dst);
  		if (NetOurIP && tmp != NetOurIP && tmp != 0xFFFFFFFF) {
  #ifdef CONFIG_MCAST_TFTP
  			if (Mcast_addr != tmp)
  #endif
  			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
  		 * (wd@denx.de), 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;
  				printf (" ICMP Host Redirect to %pI4 ", &icmph->un.gateway);
  				return;
  #if defined(CONFIG_CMD_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;
  			case ICMP_ECHO_REQUEST:
  				debug("Got ICMP ECHO REQUEST, return %d bytes \n",
  					ETHER_HDR_SIZE + len);
  
  				memcpy (&et->et_dest[0], &et->et_src[0], 6);
  				memcpy (&et->et_src[ 0], NetOurEther, 6);
  
  				ip->ip_sum = 0;
  				ip->ip_off = 0;
  				NetCopyIP((void*)&ip->ip_dst, &ip->ip_src);
  				NetCopyIP((void*)&ip->ip_src, &NetOurIP);
  				ip->ip_sum = ~NetCksum((uchar *)ip, IP_HDR_SIZE_NO_UDP >> 1);
  
  				icmph->type = ICMP_ECHO_REPLY;
  				icmph->checksum = 0;
  				icmph->checksum = ~NetCksum((uchar *)icmph,
  						(len - IP_HDR_SIZE_NO_UDP) >> 1);
  				(void) eth_send((uchar *)et, ETHER_HDR_SIZE + len);
  				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)) {
  				printf(" UDP wrong checksum %08lx %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 */
  #if defined(CONFIG_CMD_PING)
  	case PING:
  		if (NetPingIP == 0) {
  			puts ("*** ERROR: ping address not given\n");
  			return (1);
  		}
  		goto common;
  #endif
  #if defined(CONFIG_CMD_SNTP)
  	case SNTP:
  		if (NetNtpServerIP == 0) {
  			puts ("*** ERROR: NTP server address not given\n");
  			return (1);
  		}
  		goto common;
  #endif
  #if defined(CONFIG_CMD_DNS)
  	case DNS:
  		if (NetOurDNSIP == 0) {
  			puts("*** ERROR: DNS server address not given\n");
  			return 1;
  		}
  		goto common;
  #endif
  #if defined(CONFIG_CMD_NFS)
  	case NFS:
  #endif
  	case NETCONS:
  	case TFTP:
  		if (NetServerIP == 0) {
  			puts ("*** ERROR: `serverip' not set\n");
  			return (1);
  		}
  #if defined(CONFIG_CMD_PING) || defined(CONFIG_CMD_SNTP)
      common:
  #endif
  
  		if (NetOurIP == 0) {
  			puts ("*** 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:
  				puts ("*** ERROR: No ethernet found.\n");
  				return (1);
  			case 0:
  				puts ("*** ERROR: `ethaddr' not set\n");
  				break;
  			default:
  				printf ("*** ERROR: `eth%daddr' not set\n",
  					num);
  				break;
  			}
  
  			NetStartAgain ();
  			return (2);
  #else
  			puts ("*** 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)
  {
  	ushort myvlanid;
  
  	myvlanid = ntohs(NetOurVLAN);
  	if (myvlanid == (ushort)-1)
  		myvlanid = VLAN_NONE;
  
  	return ((myvlanid & VLAN_IDMASK) == VLAN_NONE) ? ETHER_HDR_SIZE : VLAN_ETHER_HDR_SIZE;
  }
  
  int
  NetSetEther(volatile uchar * xet, uchar * addr, uint prot)
  {
  	Ethernet_t *et = (Ethernet_t *)xet;
  	ushort myvlanid;
  
  	myvlanid = ntohs(NetOurVLAN);
  	if (myvlanid == (ushort)-1)
  		myvlanid = VLAN_NONE;
  
  	memcpy (et->et_dest, addr, 6);
  	memcpy (et->et_src, NetOurEther, 6);
  	if ((myvlanid & VLAN_IDMASK) == VLAN_NONE) {
  	et->et_protlen = htons(prot);
  		return ETHER_HDR_SIZE;
  	} else {
  		VLAN_Ethernet_t *vet = (VLAN_Ethernet_t *)xet;
  
  		vet->vet_vlan_type = htons(PROT_VLAN);
  		vet->vet_tag = htons((0 << 5) | (myvlanid & VLAN_IDMASK));
  		vet->vet_type = htons(prot);
  		return VLAN_ETHER_HDR_SIZE;
  	}
  }
  
  void
  NetSetIP(volatile uchar * xip, IPaddr_t dest, int dport, int sport, int len)
  {
  	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(IP_FLAGS_DFRAG);	/* Don't fragment */
  	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 (char *dst, char *src, int size)
  {
  	if (*src && (*src == '"')) {
  		++src;
  		--size;
  	}
  
  	while ((--size > 0) && *src && (*src != '"')) {
  		*dst++ = *src++;
  	}
  	*dst = '\0';
  }
  
  #endif
  
  #if defined(CONFIG_CMD_NFS) || defined(CONFIG_CMD_SNTP) || defined(CONFIG_CMD_DNS)
  /*
   * make port a little random, but use something trivial to compute
   */
  unsigned int random_port(void)
  {
  	return 1024 + (get_timer(0) % 0x8000);;
  }
  #endif
  
  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 VLAN_to_string(ushort x, char *s)
  {
  	x = ntohs(x);
  
  	if (x == (ushort)-1)
  		x = VLAN_NONE;
  
  	if (x == VLAN_NONE)
  		strcpy(s, "none");
  	else
  		sprintf(s, "%d", x & VLAN_IDMASK);
  }
  
  ushort string_to_VLAN(char *s)
  {
  	ushort id;
  
  	if (s == NULL)
  		return htons(VLAN_NONE);
  
  	if (*s < '0' || *s > '9')
  		id = VLAN_NONE;
  	else
  		id = (ushort)simple_strtoul(s, NULL, 10);
  
  	return htons(id);
  }
  
  IPaddr_t getenv_IPaddr (char *var)
  {
  	return (string_to_ip(getenv(var)));
  }
  
  ushort getenv_VLAN(char *var)
  {
  	return (string_to_VLAN(getenv(var)));
  }
  