/*
   *	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"

  #ifdef CONFIG_CMD_RARP

  #include "rarp.h"

  #endif

  #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

  DECLARE_GLOBAL_DATA_PTR;

  #ifndef	CONFIG_ARP_TIMEOUT

  /* Milliseconds before trying ARP again */
  # define ARP_TIMEOUT		5000UL

  #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 **/

  /* Our subnet mask (0=unknown) */

  IPaddr_t	NetOurSubnetMask;

  /* Our gateways IP address */

  IPaddr_t	NetOurGatewayIP;

  /* Our DNS IP address */

  IPaddr_t	NetOurDNSIP;

  #if defined(CONFIG_BOOTP_DNS2)

  /* Our 2nd DNS IP address */

  IPaddr_t	NetOurDNS2IP;

  #endif
  /* Our NIS domain */

  char		NetOurNISDomain[32] = {0,};

  /* Our hostname */

  char		NetOurHostName[32] = {0,};

  /* Our bootpath */

  char		NetOurRootPath[64] = {0,};

  /* Our bootfile size in blocks */

  ushort		NetBootFileSize;

  #ifdef CONFIG_MCAST_TFTP	/* Multicast TFTP */
  IPaddr_t Mcast_addr;
  #endif

  /** END OF BOOTP EXTENTIONS **/

  /* The actual transferred size of the bootfile (in bytes) */
  ulong		NetBootFileXferSize;
  /* Our ethernet address */
  uchar		NetOurEther[6];
  /* Boot server enet address */

  uchar		NetServerEther[6];

  /* Our IP addr (0 = unknown) */
  IPaddr_t	NetOurIP;
  /* Server IP addr (0 = unknown) */
  IPaddr_t	NetServerIP;
  /* Current receive packet */
  volatile uchar *NetRxPacket;
  /* Current rx packet length */
  int		NetRxPacketLen;
  /* IP packet ID */
  unsigned	NetIPID;
  /* Ethernet bcast address */

  uchar		NetBcastAddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
  uchar		NetEtherNullAddr[6];

  #ifdef CONFIG_API
  void		(*push_packet)(volatile void *, int len) = 0;
  #endif

  #if defined(CONFIG_CMD_CDP)

  /* Ethernet bcast address */

  uchar		NetCDPAddr[6] = { 0x01, 0x00, 0x0c, 0xcc, 0xcc, 0xcc };

  #endif

  /* Network loop state */
  int		NetState;

  /* Tried all network devices */

  int		NetRestartWrap;

  /* Network loop restarted */

  static int	NetRestarted;

  /* At least one device configured */

  static int	NetDevExists;

  /* XXX in both little & big endian machines 0xFFFF == ntohs(-1) */

  /* default is without VLAN */
  ushort		NetOurVLAN = 0xFFFF;
  /* ditto */
  ushort		NetOurNativeVLAN = 0xFFFF;

  /* Boot File name */
  char		BootFile[128];

  #if defined(CONFIG_CMD_PING)

  /* the ip address to ping */
  IPaddr_t	NetPingIP;

  
  static void PingStart(void);
  #endif

  #if defined(CONFIG_CMD_CDP)

  static void CDPStart(void);
  #endif

  #if defined(CONFIG_CMD_SNTP)

  /* NTP server IP address */
  IPaddr_t	NetNtpServerIP;
  /* offset time from UTC */

  int		NetTimeOffset;

  #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];

  /* Receive packet */
  volatile uchar *NetRxPackets[PKTBUFSRX];

  /* Current RX packet handler */
  static rxhand_f *packetHandler;

  #ifdef CONFIG_CMD_TFTPPUT

  static rxhand_icmp_f *packet_icmp_handler;	/* Current ICMP rx handler */

  #endif

  /* Current timeout handler */
  static thand_f *timeHandler;
  /* Time base value */
  static ulong	timeStart;
  /* Current timeout value */
  static ulong	timeDelta;
  /* THE transmit packet */

  volatile uchar *NetTxPacket;

  static int net_check_prereq(enum proto_t protocol);

  static int NetTryCount;

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

  
  IPaddr_t	NetArpWaitPacketIP;
  IPaddr_t	NetArpWaitReplyIP;

  /* MAC address of waiting packet's destination */
  uchar	       *NetArpWaitPacketMAC;
  /* THE transmit packet */
  uchar	       *NetArpWaitTxPacket;

  int		NetArpWaitTxPacketSize;

  uchar		NetArpWaitPacketBuf[PKTSIZE_ALIGN + PKTALIGN];

  ulong		NetArpWaitTimerStart;
  int		NetArpWaitTry;

  void ArpRequest(void)

  {

  	volatile uchar *pkt;

  	ARP_t *arp;

  	debug("ARP broadcast %d
  ", 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);

  	/* source ET addr */

  	memcpy(&arp->ar_data[0], NetOurEther, 6);

  	/* source IP addr */

  	NetWriteIP((uchar *) &arp->ar_data[6], NetOurIP);

  	/* dest ET addr = 0 */
  	memset(&arp->ar_data[10], '\0', 6);

  	if ((NetArpWaitPacketIP & NetOurSubnetMask) !=
  	    (NetOurIP & NetOurSubnetMask)) {
  		if (NetOurGatewayIP == 0) {

  			puts("## Warning: gatewayip needed but not set
  ");

  			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("
  ARP Retry count exceeded; starting again
  ");

  			NetArpWaitTry = 0;
  			NetStartAgain();
  		} else {
  			NetArpWaitTimerStart = t;
  			ArpRequest();
  		}
  	}
  }

  /*
   * Check if autoload is enabled. If so, use either NFS or TFTP to download
   * the boot file.
   */
  void net_auto_load(void)
  {
  	const char *s = getenv("autoload");
  
  	if (s != NULL) {
  		if (*s == 'n') {
  			/*
  			 * Just use BOOTP/RARP to configure system;
  			 * Do not use TFTP to load the bootfile.
  			 */
  			NetState = NETLOOP_SUCCESS;
  			return;
  		}
  #if defined(CONFIG_CMD_NFS)
  		if (strcmp(s, "NFS") == 0) {
  			/*
  			 * Use NFS to load the bootfile.
  			 */
  			NfsStart();
  			return;
  		}
  #endif
  	}
  	TftpStart(TFTPGET);
  }

  static void NetInitLoop(enum proto_t protocol)

  {

  	static int env_changed_id;

  	bd_t *bd = gd->bd;

  	int env_id = get_env_id();

  
  	/* update only when the environment has changed */

  	if (env_changed_id != env_id) {

  		NetOurIP = getenv_IPaddr("ipaddr");
  		NetCopyIP(&bd->bi_ip_addr, &NetOurIP);

  		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(enum proto_t protocol)

  {

  	bd_t *bd = gd->bd;

  	int ret = -1;

  	NetRestarted = 0;
  	NetDevExists = 0;

  	/* XXX problem with bss workaround */
  	NetArpWaitPacketMAC = NULL;
  	NetArpWaitTxPacket = NULL;
  	NetArpWaitPacketIP = 0;
  	NetArpWaitReplyIP = 0;
  	NetArpWaitTxPacket = NULL;
  	NetTxPacket = NULL;

  	NetTryCount = 1;

  	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;

  	}

  	bootstage_mark_name(BOOTSTAGE_ID_ETH_START, "eth_start");

  	eth_halt();

  	eth_set_current();

  	if (eth_init(bd) < 0) {
  		eth_halt();

  		return -1;

  	}

  
  restart:

  	memcpy(NetOurEther, eth_get_dev()->enetaddr, 6);

  
  	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;

  	case 2:
  		/* network device not configured */
  		break;

  
  	case 0:

  		NetDevExists = 1;

  		NetBootFileXferSize = 0;

  		switch (protocol) {

  		case TFTPGET:

  #ifdef CONFIG_CMD_TFTPPUT
  		case TFTPPUT:
  #endif

  			/* always use ARP to get server ethernet address */

  			TftpStart(protocol);

  			break;

  #ifdef CONFIG_CMD_TFTPSRV
  		case TFTPSRV:
  			TftpStartServer();
  			break;
  #endif

  #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;

  #if defined(CONFIG_CMD_RARP)

  		case RARP:
  			RarpTry = 0;

  			NetOurIP = 0;

  			RarpRequest();

  			break;

  #endif

  #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;
  		}

  		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("
  Abort
  ");

  			goto done;

  		}

  		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:

  			NetRestarted = 1;

  			goto restart;
  
  		case NETLOOP_SUCCESS:
  			if (NetBootFileXferSize > 0) {

  				char buf[20];

  				printf("Bytes transferred = %ld (%lx hex)
  ",
  					NetBootFileXferSize,
  					NetBootFileXferSize);

  				sprintf(buf, "%lX", NetBootFileXferSize);

  				setenv("filesize", buf);

  
  				sprintf(buf, "%lX", (unsigned long)load_addr);
  				setenv("fileaddr", buf);

  			}
  			eth_halt();

  			ret = NetBootFileXferSize;
  			goto done;

  
  		case NETLOOP_FAIL:

  			goto done;

  		}
  	}

  
  done:

  #ifdef CONFIG_CMD_TFTPPUT

  	/* Clear out the handlers */
  	NetSetHandler(NULL);
  	net_set_icmp_handler(NULL);

  #endif

  	return ret;

  }
  
  /**********************************************************************/
  
  static void
  startAgainTimeout(void)
  {
  	NetState = NETLOOP_RESTART;
  }
  
  static void

  startAgainHandler(uchar *pkt, unsigned dest, IPaddr_t sip,
  		  unsigned src, unsigned len)

  {
  	/* Totally ignore the packet */
  }

  void NetStartAgain(void)

  {

  	char *nretry;

  	int retry_forever = 0;
  	unsigned long retrycnt = 0;
  
  	nretry = getenv("netretry");
  	if (nretry) {
  		if (!strcmp(nretry, "yes"))
  			retry_forever = 1;
  		else if (!strcmp(nretry, "no"))
  			retrycnt = 0;
  		else if (!strcmp(nretry, "once"))
  			retrycnt = 1;
  		else
  			retrycnt = simple_strtoul(nretry, NULL, 0);
  	} else
  		retry_forever = 1;
  
  	if ((!retry_forever) && (NetTryCount >= retrycnt)) {
  		eth_halt();

  		NetState = NETLOOP_FAIL;
  		return;
  	}

  
  	NetTryCount++;

  	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) {

  			NetSetTimeout(10000UL, startAgainTimeout);
  			NetSetHandler(startAgainHandler);

  		} else {

  			NetState = NETLOOP_FAIL;
  		}

  	} else {

  		NetState = NETLOOP_RESTART;
  	}

  }
  
  /**********************************************************************/
  /*
   *	Miscelaneous bits.
   */
  
  void

  NetSetHandler(rxhand_f *f)

  {
  	packetHandler = f;
  }

  #ifdef CONFIG_CMD_TFTPPUT

  void net_set_icmp_handler(rxhand_icmp_f *f)
  {
  	packet_icmp_handler = f;
  }

  #endif

  
  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 %08x
  ", 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 %08x/%pM
  ", 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 %08x
  ", 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_HDR_SIZE / 4 (not including UDP) */
  	ip->ip_hl_v  = 0x45;

  	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;

  	/* already in network byte order */

  	NetCopyIP((void *)&ip->ip_src, &NetOurIP);

  	/* - "" - */

  	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, IPaddr_t sip, unsigned src,
  	    unsigned len)

  {

  	if (sip != NetPingIP)

  		return;
  
  	NetState = NETLOOP_SUCCESS;
  }
  
  static void PingStart(void)
  {

  	printf("Using %s device
  ", eth_get_name());

  	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;

  	/* checksum (0 for later calculation) */
  	*s++ = htons(0);

  
  	/* 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, IPaddr_t sip, unsigned src,
  		unsigned len)

  {
  	/* nothing */
  }
  
  static void

  CDPHandler(const uchar *pkt, unsigned len)

  {
  	const uchar *t;
  	const ushort *ss;
  	ushort type, tlen;

  	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
  ",
  				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;

  				ss = (const ushort *)(t + 1);

  
  #ifdef CONFIG_CDP_APPLIANCE_VLAN_TYPE

  				if (t[0] == CONFIG_CDP_APPLIANCE_VLAN_TYPE)

  					vlan = *ss;

  #else

  				/* XXX will this work; dunno */
  				vlan = ntohs(*ss);

  #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
  ");
  	return;
  }
  
  static void CDPStart(void)
  {

  	printf("Using %s device
  ", eth_get_name());

  	CDPSeq = 0;
  	CDPOK = 0;
  
  	CDPNativeVLAN = htons(-1);
  	CDPApplianceVLAN = htons(-1);

  	NetSetTimeout(CDP_TIMEOUT, CDPTimeout);
  	NetSetHandler(CDPDummyHandler);

  
  	CDPSendTrigger();
  }

  #endif

  #ifdef CONFIG_IP_DEFRAG
  /*
   * This function collects fragments in a single packet, according
   * to the algorithm in RFC815. It returns NULL or the pointer to
   * a complete packet, in static storage
   */
  #ifndef CONFIG_NET_MAXDEFRAG
  #define CONFIG_NET_MAXDEFRAG 16384
  #endif
  /*
   * MAXDEFRAG, above, is chosen in the config file and  is real data
   * so we need to add the NFS overhead, which is more than TFTP.
   * To use sizeof in the internal unnamed structures, we need a real
   * instance (can't do "sizeof(struct rpc_t.u.reply))", unfortunately).
   * The compiler doesn't complain nor allocates the actual structure
   */
  static struct rpc_t rpc_specimen;
  #define IP_PKTSIZE (CONFIG_NET_MAXDEFRAG + sizeof(rpc_specimen.u.reply))
  
  #define IP_MAXUDP (IP_PKTSIZE - IP_HDR_SIZE_NO_UDP)
  
  /*
   * this is the packet being assembled, either data or frag control.
   * Fragments go by 8 bytes, so this union must be 8 bytes long
   */
  struct hole {
  	/* first_byte is address of this structure */
  	u16 last_byte;	/* last byte in this hole + 1 (begin of next hole) */
  	u16 next_hole;	/* index of next (in 8-b blocks), 0 == none */
  	u16 prev_hole;	/* index of prev, 0 == none */
  	u16 unused;
  };
  
  static IP_t *__NetDefragment(IP_t *ip, int *lenp)
  {
  	static uchar pkt_buff[IP_PKTSIZE] __attribute__((aligned(PKTALIGN)));
  	static u16 first_hole, total_len;
  	struct hole *payload, *thisfrag, *h, *newh;
  	IP_t *localip = (IP_t *)pkt_buff;
  	uchar *indata = (uchar *)ip;
  	int offset8, start, len, done = 0;
  	u16 ip_off = ntohs(ip->ip_off);
  
  	/* payload starts after IP header, this fragment is in there */
  	payload = (struct hole *)(pkt_buff + IP_HDR_SIZE_NO_UDP);
  	offset8 =  (ip_off & IP_OFFS);
  	thisfrag = payload + offset8;
  	start = offset8 * 8;
  	len = ntohs(ip->ip_len) - IP_HDR_SIZE_NO_UDP;
  
  	if (start + len > IP_MAXUDP) /* fragment extends too far */
  		return NULL;
  
  	if (!total_len || localip->ip_id != ip->ip_id) {
  		/* new (or different) packet, reset structs */
  		total_len = 0xffff;
  		payload[0].last_byte = ~0;
  		payload[0].next_hole = 0;
  		payload[0].prev_hole = 0;
  		first_hole = 0;
  		/* any IP header will work, copy the first we received */
  		memcpy(localip, ip, IP_HDR_SIZE_NO_UDP);
  	}
  
  	/*
  	 * What follows is the reassembly algorithm. We use the payload
  	 * array as a linked list of hole descriptors, as each hole starts
  	 * at a multiple of 8 bytes. However, last byte can be whatever value,
  	 * so it is represented as byte count, not as 8-byte blocks.
  	 */
  
  	h = payload + first_hole;
  	while (h->last_byte < start) {
  		if (!h->next_hole) {
  			/* no hole that far away */
  			return NULL;
  		}
  		h = payload + h->next_hole;
  	}

  	/* last fragment may be 1..7 bytes, the "+7" forces acceptance */
  	if (offset8 + ((len + 7) / 8) <= h - payload) {

  		/* no overlap with holes (dup fragment?) */
  		return NULL;
  	}
  
  	if (!(ip_off & IP_FLAGS_MFRAG)) {
  		/* no more fragmentss: truncate this (last) hole */
  		total_len = start + len;
  		h->last_byte = start + len;
  	}
  
  	/*
  	 * There is some overlap: fix the hole list. This code doesn't
  	 * deal with a fragment that overlaps with two different holes
  	 * (thus being a superset of a previously-received fragment).
  	 */

  	if ((h >= thisfrag) && (h->last_byte <= start + len)) {

  		/* complete overlap with hole: remove hole */
  		if (!h->prev_hole && !h->next_hole) {
  			/* last remaining hole */
  			done = 1;
  		} else if (!h->prev_hole) {
  			/* first hole */
  			first_hole = h->next_hole;
  			payload[h->next_hole].prev_hole = 0;
  		} else if (!h->next_hole) {
  			/* last hole */
  			payload[h->prev_hole].next_hole = 0;
  		} else {
  			/* in the middle of the list */
  			payload[h->next_hole].prev_hole = h->prev_hole;
  			payload[h->prev_hole].next_hole = h->next_hole;
  		}
  
  	} else if (h->last_byte <= start + len) {
  		/* overlaps with final part of the hole: shorten this hole */
  		h->last_byte = start;
  
  	} else if (h >= thisfrag) {
  		/* overlaps with initial part of the hole: move this hole */
  		newh = thisfrag + (len / 8);
  		*newh = *h;
  		h = newh;
  		if (h->next_hole)
  			payload[h->next_hole].prev_hole = (h - payload);
  		if (h->prev_hole)
  			payload[h->prev_hole].next_hole = (h - payload);
  		else
  			first_hole = (h - payload);
  
  	} else {
  		/* fragment sits in the middle: split the hole */
  		newh = thisfrag + (len / 8);
  		*newh = *h;
  		h->last_byte = start;
  		h->next_hole = (newh - payload);
  		newh->prev_hole = (h - payload);
  		if (newh->next_hole)
  			payload[newh->next_hole].prev_hole = (newh - payload);
  	}
  
  	/* finally copy this fragment and possibly return whole packet */
  	memcpy((uchar *)thisfrag, indata + IP_HDR_SIZE_NO_UDP, len);
  	if (!done)
  		return NULL;
  
  	localip->ip_len = htons(total_len);
  	*lenp = total_len + IP_HDR_SIZE_NO_UDP;
  	return localip;
  }
  
  static inline IP_t *NetDefragment(IP_t *ip, int *lenp)
  {
  	u16 ip_off = ntohs(ip->ip_off);
  	if (!(ip_off & (IP_OFFS | IP_FLAGS_MFRAG)))
  		return ip; /* not a fragment */
  	return __NetDefragment(ip, lenp);
  }
  
  #else /* !CONFIG_IP_DEFRAG */
  
  static inline IP_t *NetDefragment(IP_t *ip, int *lenp)
  {
  	u16 ip_off = ntohs(ip->ip_off);
  	if (!(ip_off & (IP_OFFS | IP_FLAGS_MFRAG)))
  		return ip; /* not a fragment */
  	return NULL;
  }
  #endif

  /**
   * Receive an ICMP packet. We deal with REDIRECT and PING here, and silently
   * drop others.
   *
   * @parma ip	IP packet containing the ICMP
   */
  static void receive_icmp(IP_t *ip, int len, IPaddr_t src_ip, Ethernet_t *et)
  {
  	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);
  		break;
  #if defined(CONFIG_CMD_PING)
  	case ICMP_ECHO_REPLY:
  		/*
  			* IP header OK.  Pass the packet to the
  			* current handler.
  			*/
  		/*
  		 * XXX point to ip packet - should this use
  		 * packet_icmp_handler?
  		 */
  		(*packetHandler)((uchar *)ip, 0, src_ip, 0, 0);
  		break;
  	case ICMP_ECHO_REQUEST:
  		debug("Got ICMP ECHO REQUEST, return %d bytes
  ",
  			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);
  		break;
  #endif
  	default:

  #ifdef CONFIG_CMD_TFTPPUT

  		if (packet_icmp_handler)
  			packet_icmp_handler(icmph->type, icmph->code,
  				ntohs(ip->udp_dst), src_ip, ntohs(ip->udp_src),
  				icmph->un.data, ntohs(ip->udp_len));

  #endif

  		break;
  	}
  }

  void

  NetReceive(volatile uchar *inpkt, int len)

  {
  	Ethernet_t *et;
  	IP_t	*ip;
  	ARP_t	*arp;
  	IPaddr_t tmp;

  	IPaddr_t src_ip;

  	int	x;

  	uchar *pkt;

  #if defined(CONFIG_CMD_CDP)

  	int iscdp;
  #endif
  	ushort cti = 0, vlanid = VLAN_NONE, myvlanid, mynvlanid;

  	debug("packet received
  ");

  	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
  ");

  	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
  ");

  		/* 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
  ", 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
  ");

  		arp = (ARP_t *)ip;
  		if (len < ARP_HDR_SIZE) {
  			printf("bad length %d < %d
  ", 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
  ");

  			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)
  ",

  				arp->ar_data);

  
  			tmp = NetReadIP(&arp->ar_data[6]);
  
  			/* matched waiting packet's address */
  			if (tmp == NetArpWaitReplyIP) {

  				debug("Got it
  ");

  				/* save address for later use */

  				memcpy(NetArpWaitPacketMAC,
  				       &arp->ar_data[0], 6);

  #ifdef CONFIG_NETCONSOLE

  				(*packetHandler)(0, 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
  ",
  			      ntohs(arp->ar_op));

  			return;
  		}

  		break;

  #ifdef CONFIG_CMD_RARP

  	case PROT_RARP:

  		debug("Got RARP
  ");

  		arp = (ARP_t *)ip;
  		if (len < ARP_HDR_SIZE) {
  			printf("bad length %d < %d
  ", 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
  ");

  		} 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, 0);

  		}
  		break;

  #endif

  	case PROT_IP:

  		debug("Got IP
  ");

  		/* Before we start poking the header, make sure it is there */

  		if (len < IP_HDR_SIZE) {

  			debug("len bad %d < %lu
  ", len, (ulong)IP_HDR_SIZE);

  			return;
  		}

  		/* Check the packet length */

  		if (len < ntohs(ip->ip_len)) {
  			printf("len bad %d < %d
  ", len, ntohs(ip->ip_len));
  			return;
  		}
  		len = ntohs(ip->ip_len);

  		debug("len=%d, v=%02x
  ", len, ip->ip_hl_v & 0xff);

  		/* Can't deal with anything except IPv4 */

  		if ((ip->ip_hl_v & 0xf0) != 0x40)

  			return;

  		/* Can't deal with IP options (headers != 20 bytes) */

  		if ((ip->ip_hl_v & 0x0f) > 0x05)

  			return;

  		/* Check the Checksum of the header */

  		if (!NetCksumOk((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2)) {

  			puts("checksum bad
  ");

  			return;
  		}

  		/* If it is not for us, ignore it */

  		tmp = NetReadIP(&ip->ip_dst);
  		if (NetOurIP && tmp != NetOurIP && tmp != 0xFFFFFFFF) {

  #ifdef CONFIG_MCAST_TFTP

  			if (Mcast_addr != tmp)

  #endif

  				return;

  		}

  		/* Read source IP address for later use */
  		src_ip = NetReadIP(&ip->ip_src);

  		/*

  		 * The function returns the unchanged packet if it's not
  		 * a fragment, and either the complete packet or NULL if
  		 * it is a fragment (if !CONFIG_IP_DEFRAG, it returns NULL)
  		 */

  		ip = NetDefragment(ip, &len);
  		if (!ip)

  			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.

  		 *
  		 * Simon Glass <sjg@chromium.org>: We get an ICMP when
  		 * we send a tftp packet to a dead connection, or when
  		 * there is no server at the other end.

  		 */
  		if (ip->ip_p == IPPROTO_ICMP) {

  			receive_icmp(ip, len, src_ip, et);
  			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
  ",
  					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),

  						src_ip,

  						ntohs(ip->udp_src),
  						ntohs(ip->udp_len) - 8);

  		break;
  	}
  }
  
  
  /**********************************************************************/

  static int net_check_prereq(enum proto_t protocol)

  {
  	switch (protocol) {

  		/* Fall through */

  #if defined(CONFIG_CMD_PING)

  	case PING:

  		if (NetPingIP == 0) {

  			puts("*** ERROR: ping address not given
  ");

  			return 1;

  		}
  		goto common;

  #endif

  #if defined(CONFIG_CMD_SNTP)

  	case SNTP:
  		if (NetNtpServerIP == 0) {

  			puts("*** ERROR: NTP server address not given
  ");

  			return 1;

  		}
  		goto common;
  #endif

  #if defined(CONFIG_CMD_DNS)
  	case DNS:
  		if (NetOurDNSIP == 0) {
  			puts("*** ERROR: DNS server address not given
  ");
  			return 1;
  		}
  		goto common;
  #endif

  #if defined(CONFIG_CMD_NFS)

  	case NFS:
  #endif

  	case TFTPGET:

  	case TFTPPUT:

  		if (NetServerIP == 0) {

  			puts("*** ERROR: `serverip' not set
  ");

  			return 1;

  		}

  #if	defined(CONFIG_CMD_PING) || defined(CONFIG_CMD_SNTP) || \
  	defined(CONFIG_CMD_DNS)
  common:

  #endif

  		/* Fall through */

  	case NETCONS:

  	case TFTPSRV:

  		if (NetOurIP == 0) {

  			puts("*** ERROR: `ipaddr' not set
  ");

  			return 1;

  		}
  		/* Fall through */

  #ifdef CONFIG_CMD_RARP

  	case RARP:

  #endif

  	case BOOTP:

  	case CDP:

  	case DHCP:

  		if (memcmp(NetOurEther, "\0\0\0\0\0\0", 6) == 0) {

  			extern int eth_get_dev_index(void);
  			int num = eth_get_dev_index();

  			switch (num) {
  			case -1:

  				puts("*** ERROR: No ethernet found.
  ");

  				return 1;

  			case 0:

  				puts("*** ERROR: `ethaddr' not set
  ");

  				break;

  			default:

  				printf("*** ERROR: `eth%daddr' not set
  ",

  					num);
  				break;

  			}

  			NetStartAgain();

  			return 2;

  		}
  		/* Fall through */
  	default:

  		return 0;

  	}

  	return 0;		/* OK */

  }
  /**********************************************************************/
  
  int

  NetCksumOk(uchar *ptr, int len)