/*

   * Copyright 1994, 1995, 2000 Neil Russell.
   * (See License)
   * Copyright 2000, 2001 DENX Software Engineering, Wolfgang Denk, wd@denx.de

   * Copyright 2011 Comelit Group SpA,
   *                Luca Ceresoli <luca.ceresoli@comelit.it>

   */
  
  #include <common.h>
  #include <command.h>

  #include <efi_loader.h>

  #include <mapmem.h>

  #include <net.h>

  #include <net/tftp.h>

  #include "bootp.h"

  #ifdef CONFIG_SYS_DIRECT_FLASH_TFTP
  #include <flash.h>
  #endif

  /* Well known TFTP port # */
  #define WELL_KNOWN_PORT	69
  /* Millisecs to timeout for lost pkt */

  #define TIMEOUT		5000UL

  #ifndef	CONFIG_NET_RETRY_COUNT

  /* # of timeouts before giving up */

  # define TIMEOUT_COUNT	10

  #else
  # define TIMEOUT_COUNT  (CONFIG_NET_RETRY_COUNT * 2)
  #endif

  /* Number of "loading" hashes per line (for checking the image size) */
  #define HASHES_PER_LINE	65

  
  /*
   *	TFTP operations.
   */
  #define TFTP_RRQ	1
  #define TFTP_WRQ	2
  #define TFTP_DATA	3
  #define TFTP_ACK	4
  #define TFTP_ERROR	5

  #define TFTP_OACK	6

  static ulong timeout_ms = TIMEOUT;
  static int timeout_count_max = TIMEOUT_COUNT;

  static ulong time_start;   /* Record time we started tftp */

  
  /*
   * These globals govern the timeout behavior when attempting a connection to a

   * TFTP server. tftp_timeout_ms specifies the number of milliseconds to

   * wait for the server to respond to initial connection. Second global,

   * tftp_timeout_count_max, gives the number of such connection retries.
   * tftp_timeout_count_max must be non-negative and tftp_timeout_ms must be

   * positive. The globals are meant to be set (and restored) by code needing
   * non-standard timeout behavior when initiating a TFTP transfer.
   */

  ulong tftp_timeout_ms = TIMEOUT;
  int tftp_timeout_count_max = TIMEOUT_COUNT;

  enum {
  	TFTP_ERR_UNDEFINED           = 0,
  	TFTP_ERR_FILE_NOT_FOUND      = 1,
  	TFTP_ERR_ACCESS_DENIED       = 2,
  	TFTP_ERR_DISK_FULL           = 3,
  	TFTP_ERR_UNEXPECTED_OPCODE   = 4,
  	TFTP_ERR_UNKNOWN_TRANSFER_ID  = 5,
  	TFTP_ERR_FILE_ALREADY_EXISTS = 6,
  };

  static struct in_addr tftp_remote_ip;

  /* The UDP port at their end */

  static int	tftp_remote_port;

  /* The UDP port at our end */

  static int	tftp_our_port;
  static int	timeout_count;

  /* packet sequence number */

  static ulong	tftp_cur_block;

  /* last packet sequence number received */

  static ulong	tftp_prev_block;

  /* count of sequence number wraparounds */

  static ulong	tftp_block_wrap;

  /* memory offset due to wrapping */

  static ulong	tftp_block_wrap_offset;
  static int	tftp_state;

  #ifdef CONFIG_TFTP_TSIZE

  /* The file size reported by the server */

  static int	tftp_tsize;

  /* The number of hashes we printed */

  static short	tftp_tsize_num_hash;

  #endif

  #ifdef CONFIG_CMD_TFTPPUT

  /* 1 if writing, else 0 */
  static int	tftp_put_active;
  /* 1 if we have sent the last block */
  static int	tftp_put_final_block_sent;

  #else

  #define tftp_put_active	0

  #endif

  #define STATE_SEND_RRQ	1

  #define STATE_DATA	2
  #define STATE_TOO_LARGE	3
  #define STATE_BAD_MAGIC	4

  #define STATE_OACK	5

  #define STATE_RECV_WRQ	6

  #define STATE_SEND_WRQ	7

  /* default TFTP block size */
  #define TFTP_BLOCK_SIZE		512
  /* sequence number is 16 bit */
  #define TFTP_SEQUENCE_SIZE	((ulong)(1<<16))

  #define DEFAULT_NAME_LEN	(8 + 4 + 1)
  static char default_filename[DEFAULT_NAME_LEN];

  
  #ifndef CONFIG_TFTP_FILE_NAME_MAX_LEN
  #define MAX_LEN 128
  #else
  #define MAX_LEN CONFIG_TFTP_FILE_NAME_MAX_LEN
  #endif
  
  static char tftp_filename[MAX_LEN];

  /* 512 is poor choice for ethernet, MTU is typically 1500.
   * Minus eth.hdrs thats 1468.  Can get 2x better throughput with

   * almost-MTU block sizes.  At least try... fall back to 512 if need be.

   * (but those using CONFIG_IP_DEFRAG may want to set a larger block in cfg file)

   */

  #ifdef CONFIG_TFTP_BLOCKSIZE
  #define TFTP_MTU_BLOCKSIZE CONFIG_TFTP_BLOCKSIZE
  #else

  #define TFTP_MTU_BLOCKSIZE 1468

  #endif

  static unsigned short tftp_block_size = TFTP_BLOCK_SIZE;
  static unsigned short tftp_block_size_option = TFTP_MTU_BLOCKSIZE;

  
  #ifdef CONFIG_MCAST_TFTP
  #include <malloc.h>
  #define MTFTP_BITMAPSIZE	0x1000

  static unsigned *tftp_mcast_bitmap;
  static int tftp_mcast_prev_hole;
  static int tftp_mcast_bitmap_size = MTFTP_BITMAPSIZE;
  static int tftp_mcast_disabled;
  static int tftp_mcast_master_client;
  static int tftp_mcast_active;
  static int tftp_mcast_port;
  /* can get 'last' block before done..*/
  static ulong tftp_mcast_ending_block;

  static void parse_multicast_oack(char *pkt, int len);

  static void mcast_cleanup(void)

  {

  	if (net_mcast_addr)
  		eth_mcast_join(net_mcast_addr, 0);

  	if (tftp_mcast_bitmap)
  		free(tftp_mcast_bitmap);
  	tftp_mcast_bitmap = NULL;

  	net_mcast_addr.s_addr = 0;

  	tftp_mcast_active = 0;
  	tftp_mcast_port = 0;
  	tftp_mcast_ending_block = -1;

  }
  
  #endif	/* CONFIG_MCAST_TFTP */

  static inline void store_block(int block, uchar *src, unsigned len)

  {

  	ulong offset = block * tftp_block_size + tftp_block_wrap_offset;

  	ulong newsize = offset + len;

  #ifdef CONFIG_SYS_DIRECT_FLASH_TFTP

  	int i, rc = 0;

  	for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; i++) {

  		/* start address in flash? */

  		if (flash_info[i].flash_id == FLASH_UNKNOWN)
  			continue;

  		if (load_addr + offset >= flash_info[i].start[0]) {
  			rc = 1;
  			break;
  		}
  	}
  
  	if (rc) { /* Flash is destination for this packet */

  		rc = flash_write((char *)src, (ulong)(load_addr+offset), len);

  		if (rc) {

  			flash_perror(rc);

  			net_set_state(NETLOOP_FAIL);

  			return;
  		}

  	} else

  #endif /* CONFIG_SYS_DIRECT_FLASH_TFTP */

  	{

  		void *ptr = map_sysmem(load_addr + offset, len);
  
  		memcpy(ptr, src, len);
  		unmap_sysmem(ptr);

  	}

  #ifdef CONFIG_MCAST_TFTP

  	if (tftp_mcast_active)
  		ext2_set_bit(block, tftp_mcast_bitmap);

  #endif

  	if (net_boot_file_size < newsize)
  		net_boot_file_size = newsize;

  }

  /* Clear our state ready for a new transfer */

  static void new_transfer(void)

  {

  	tftp_prev_block = 0;
  	tftp_block_wrap = 0;
  	tftp_block_wrap_offset = 0;

  #ifdef CONFIG_CMD_TFTPPUT

  	tftp_put_final_block_sent = 0;

  #endif
  }

  #ifdef CONFIG_CMD_TFTPPUT
  /**
   * Load the next block from memory to be sent over tftp.
   *
   * @param block	Block number to send
   * @param dst	Destination buffer for data
   * @param len	Number of bytes in block (this one and every other)
   * @return number of bytes loaded
   */
  static int load_block(unsigned block, uchar *dst, unsigned len)
  {
  	/* We may want to get the final block from the previous set */

  	ulong offset = ((int)block - 1) * len + tftp_block_wrap_offset;

  	ulong tosend = len;

  	tosend = min(net_boot_file_size - offset, tosend);

  	(void)memcpy(dst, (void *)(save_addr + offset), tosend);
  	debug("%s: block=%d, offset=%ld, len=%d, tosend=%ld
  ", __func__,

  	      block, offset, len, tosend);

  	return tosend;
  }
  #endif

  static void tftp_send(void);
  static void tftp_timeout_handler(void);

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

  static void show_block_marker(void)
  {
  #ifdef CONFIG_TFTP_TSIZE

  	if (tftp_tsize) {
  		ulong pos = tftp_cur_block * tftp_block_size +
  			tftp_block_wrap_offset;

  		if (pos > tftp_tsize)
  			pos = tftp_tsize;

  		while (tftp_tsize_num_hash < pos * 50 / tftp_tsize) {

  			putc('#');

  			tftp_tsize_num_hash++;

  		}

  	} else

  #endif

  	{

  		if (((tftp_cur_block - 1) % 10) == 0)

  			putc('#');

  		else if ((tftp_cur_block % (10 * HASHES_PER_LINE)) == 0)

  			puts("
  \t ");
  	}
  }

  /**
   * restart the current transfer due to an error
   *
   * @param msg	Message to print for user
   */
  static void restart(const char *msg)
  {
  	printf("
  %s; starting again
  ", msg);
  #ifdef CONFIG_MCAST_TFTP
  	mcast_cleanup();
  #endif

  	net_start_again();

  }
  
  /*
   * Check if the block number has wrapped, and update progress
   *
   * TODO: The egregious use of global variables in this file should be tidied.
   */
  static void update_block_number(void)
  {
  	/*
  	 * RFC1350 specifies that the first data packet will
  	 * have sequence number 1. If we receive a sequence
  	 * number of 0 this means that there was a wrap
  	 * around of the (16 bit) counter.
  	 */

  	if (tftp_cur_block == 0 && tftp_prev_block != 0) {
  		tftp_block_wrap++;
  		tftp_block_wrap_offset += tftp_block_size * TFTP_SEQUENCE_SIZE;
  		timeout_count = 0; /* we've done well, reset the timeout */

  	} else {
  		show_block_marker();
  	}
  }

  /* The TFTP get or put is complete */
  static void tftp_complete(void)
  {
  #ifdef CONFIG_TFTP_TSIZE
  	/* Print hash marks for the last packet received */

  	while (tftp_tsize && tftp_tsize_num_hash < 49) {

  		putc('#');

  		tftp_tsize_num_hash++;

  	}

  	puts("  ");

  	print_size(tftp_tsize, "");

  #endif

  	time_start = get_timer(time_start);
  	if (time_start > 0) {
  		puts("
  \t ");	/* Line up with "Loading: " */

  		print_size(net_boot_file_size /

  			time_start * 1000, "/s");
  	}

  	puts("
  done
  ");

  	net_set_state(NETLOOP_SUCCESS);

  }

  static void tftp_send(void)

  {

  	uchar *pkt;

  	uchar *xp;
  	int len = 0;
  	ushort *s;

  #ifdef CONFIG_MCAST_TFTP

  	/* Multicast TFTP.. non-MasterClients do not ACK data. */

  	if (tftp_mcast_active && tftp_state == STATE_DATA &&
  	    tftp_mcast_master_client == 0)

  		return;
  #endif

  	/*
  	 *	We will always be sending some sort of packet, so
  	 *	cobble together the packet headers now.
  	 */

  	pkt = net_tx_packet + net_eth_hdr_size() + IP_UDP_HDR_SIZE;

  	switch (tftp_state) {

  	case STATE_SEND_RRQ:

  	case STATE_SEND_WRQ:

  		xp = pkt;

  		s = (ushort *)pkt;

  #ifdef CONFIG_CMD_TFTPPUT

  		*s++ = htons(tftp_state == STATE_SEND_RRQ ? TFTP_RRQ :

  			TFTP_WRQ);

  #else
  		*s++ = htons(TFTP_RRQ);
  #endif

  		pkt = (uchar *)s;

  		strcpy((char *)pkt, tftp_filename);

  		pkt += strlen(tftp_filename) + 1;

  		strcpy((char *)pkt, "octet");

  		pkt += 5 /*strlen("octet")*/ + 1;

  		strcpy((char *)pkt, "timeout");

  		pkt += 7 /*strlen("timeout")*/ + 1;

  		sprintf((char *)pkt, "%lu", timeout_ms / 1000);

  		debug("send option \"timeout %s\"
  ", (char *)pkt);

  		pkt += strlen((char *)pkt) + 1;

  #ifdef CONFIG_TFTP_TSIZE

  		pkt += sprintf((char *)pkt, "tsize%c%u%c",
  				0, net_boot_file_size, 0);

  #endif

  		/* try for more effic. blk size */

  		pkt += sprintf((char *)pkt, "blksize%c%d%c",

  				0, tftp_block_size_option, 0);

  #ifdef CONFIG_MCAST_TFTP

  		/* Check all preconditions before even trying the option */

  		if (!tftp_mcast_disabled) {
  			tftp_mcast_bitmap = malloc(tftp_mcast_bitmap_size);
  			if (tftp_mcast_bitmap && eth_get_dev()->mcast) {
  				free(tftp_mcast_bitmap);
  				tftp_mcast_bitmap = NULL;

  				pkt += sprintf((char *)pkt, "multicast%c%c",
  					0, 0);
  			}

  		}
  #endif /* CONFIG_MCAST_TFTP */

  		len = pkt - xp;
  		break;

  	case STATE_OACK:

  #ifdef CONFIG_MCAST_TFTP

  		/* My turn!  Start at where I need blocks I missed. */
  		if (tftp_mcast_active)
  			tftp_cur_block = ext2_find_next_zero_bit(
  				tftp_mcast_bitmap,
  				tftp_mcast_bitmap_size * 8, 0);
  		/* fall through */

  #endif

  
  	case STATE_RECV_WRQ:

  	case STATE_DATA:

  		xp = pkt;

  		s = (ushort *)pkt;

  		s[0] = htons(TFTP_ACK);

  		s[1] = htons(tftp_cur_block);

  		pkt = (uchar *)(s + 2);
  #ifdef CONFIG_CMD_TFTPPUT

  		if (tftp_put_active) {
  			int toload = tftp_block_size;
  			int loaded = load_block(tftp_cur_block, pkt, toload);

  
  			s[0] = htons(TFTP_DATA);
  			pkt += loaded;

  			tftp_put_final_block_sent = (loaded < toload);

  		}
  #endif

  		len = pkt - xp;
  		break;
  
  	case STATE_TOO_LARGE:
  		xp = pkt;

  		s = (ushort *)pkt;
  		*s++ = htons(TFTP_ERROR);

  			*s++ = htons(3);

  		pkt = (uchar *)s;

  		strcpy((char *)pkt, "File too large");

  		pkt += 14 /*strlen("File too large")*/ + 1;
  		len = pkt - xp;
  		break;
  
  	case STATE_BAD_MAGIC:
  		xp = pkt;

  		s = (ushort *)pkt;
  		*s++ = htons(TFTP_ERROR);
  		*s++ = htons(2);
  		pkt = (uchar *)s;

  		strcpy((char *)pkt, "File has bad magic");

  		pkt += 18 /*strlen("File has bad magic")*/ + 1;
  		len = pkt - xp;
  		break;
  	}

  	net_send_udp_packet(net_server_ethaddr, tftp_remote_ip,
  			    tftp_remote_port, tftp_our_port, len);

  }

  #ifdef CONFIG_CMD_TFTPPUT

  static void icmp_handler(unsigned type, unsigned code, unsigned dest,

  			 struct in_addr sip, unsigned src, uchar *pkt,
  			 unsigned len)

  {
  	if (type == ICMP_NOT_REACH && code == ICMP_NOT_REACH_PORT) {
  		/* Oh dear the other end has gone away */
  		restart("TFTP server died");
  	}
  }

  #endif

  static void tftp_handler(uchar *pkt, unsigned dest, struct in_addr sip,
  			 unsigned src, unsigned len)

  {

  	__be16 proto;
  	__be16 *s;

  	int i;

  	if (dest != tftp_our_port) {

  #ifdef CONFIG_MCAST_TFTP

  		if (tftp_mcast_active &&
  		    (!tftp_mcast_port || dest != tftp_mcast_port))

  #endif

  			return;

  	}

  	if (tftp_state != STATE_SEND_RRQ && src != tftp_remote_port &&
  	    tftp_state != STATE_RECV_WRQ && tftp_state != STATE_SEND_WRQ)

  		return;

  	if (len < 2)

  		return;

  	len -= 2;
  	/* warning: don't use increment (++) in ntohs() macros!! */

  	s = (__be16 *)pkt;

  	proto = *s++;
  	pkt = (uchar *)s;

  	switch (ntohs(proto)) {

  	case TFTP_RRQ:

  		break;

  	case TFTP_ACK:

  #ifdef CONFIG_CMD_TFTPPUT

  		if (tftp_put_active) {
  			if (tftp_put_final_block_sent) {

  				tftp_complete();
  			} else {
  				/*
  				 * Move to the next block. We want our block
  				 * count to wrap just like the other end!
  				 */
  				int block = ntohs(*s);

  				int ack_ok = (tftp_cur_block == block);

  				tftp_cur_block = (unsigned short)(block + 1);

  				update_block_number();
  				if (ack_ok)

  					tftp_send(); /* Send next data block */

  			}
  		}
  #endif

  		break;

  	default:
  		break;

  #ifdef CONFIG_CMD_TFTPSRV
  	case TFTP_WRQ:
  		debug("Got WRQ
  ");

  		tftp_remote_ip = sip;

  		tftp_remote_port = src;
  		tftp_our_port = 1024 + (get_timer(0) % 3072);

  		new_transfer();

  		tftp_send(); /* Send ACK(0) */

  		break;
  #endif

  	case TFTP_OACK:

  		debug("Got OACK: %s %s
  ",

  		      pkt, pkt + strlen((char *)pkt) + 1);
  		tftp_state = STATE_OACK;
  		tftp_remote_port = src;

  		/*
  		 * Check for 'blksize' option.
  		 * Careful: "i" is signed, "len" is unsigned, thus
  		 * something like "len-8" may give a *huge* number
  		 */

  		for (i = 0; i+8 < len; i++) {

  			if (strcmp((char *)pkt + i, "blksize") == 0) {
  				tftp_block_size = (unsigned short)
  					simple_strtoul((char *)pkt + i + 8,
  						       NULL, 10);

  				debug("Blocksize ack: %s, %d
  ",

  				      (char *)pkt + i + 8, tftp_block_size);

  			}

  #ifdef CONFIG_TFTP_TSIZE

  			if (strcmp((char *)pkt+i, "tsize") == 0) {

  				tftp_tsize = simple_strtoul((char *)pkt + i + 6,

  							   NULL, 10);

  				debug("size = %s, %d
  ",

  				      (char *)pkt + i + 6, tftp_tsize);

  			}
  #endif

  		}
  #ifdef CONFIG_MCAST_TFTP

  		parse_multicast_oack((char *)pkt, len - 1);
  		if ((tftp_mcast_active) && (!tftp_mcast_master_client))
  			tftp_state = STATE_DATA;	/* passive.. */

  		else
  #endif

  #ifdef CONFIG_CMD_TFTPPUT

  		if (tftp_put_active) {

  			/* Get ready to send the first block */

  			tftp_state = STATE_DATA;
  			tftp_cur_block++;

  		}
  #endif

  		tftp_send(); /* Send ACK or first data block */

  		break;

  	case TFTP_DATA:
  		if (len < 2)
  			return;
  		len -= 2;

  		tftp_cur_block = ntohs(*(__be16 *)pkt);

  		update_block_number();

  		if (tftp_state == STATE_SEND_RRQ)

  			debug("Server did not acknowledge timeout option!
  ");

  		if (tftp_state == STATE_SEND_RRQ || tftp_state == STATE_OACK ||
  		    tftp_state == STATE_RECV_WRQ) {

  			/* first block received */

  			tftp_state = STATE_DATA;
  			tftp_remote_port = src;

  			new_transfer();

  #ifdef CONFIG_MCAST_TFTP

  			if (tftp_mcast_active) { /* start!=1 common if mcast */
  				tftp_prev_block = tftp_cur_block - 1;

  			} else
  #endif

  			if (tftp_cur_block != 1) {	/* Assertion */
  				puts("
  TFTP error: ");
  				printf("First block is not block 1 (%ld)
  ",
  				       tftp_cur_block);
  				puts("Starting again
  
  ");

  				net_start_again();

  				break;
  			}
  		}

  		if (tftp_cur_block == tftp_prev_block) {
  			/* Same block again; ignore it. */

  			break;
  		}

  		tftp_prev_block = tftp_cur_block;

  		timeout_count_max = tftp_timeout_count_max;

  		net_set_timeout_handler(timeout_ms, tftp_timeout_handler);

  		store_block(tftp_cur_block - 1, pkt + 2, len);

  
  		/*

  		 *	Acknowledge the block just received, which will prompt

  		 *	the remote for the next one.

  		 */

  #ifdef CONFIG_MCAST_TFTP

  		/* if I am the MasterClient, actively calculate what my next
  		 * needed block is; else I'm passive; not ACKING

  		 */

  		if (tftp_mcast_active) {
  			if (len < tftp_block_size)  {
  				tftp_mcast_ending_block = tftp_cur_block;
  			} else if (tftp_mcast_master_client) {
  				tftp_mcast_prev_hole = ext2_find_next_zero_bit(
  					tftp_mcast_bitmap,
  					tftp_mcast_bitmap_size * 8,
  					tftp_mcast_prev_hole);
  				tftp_cur_block = tftp_mcast_prev_hole;
  				if (tftp_cur_block >
  				    ((tftp_mcast_bitmap_size * 8) - 1)) {
  					debug("tftpfile too big
  ");

  					/* try to double it and retry */

  					tftp_mcast_bitmap_size <<= 1;

  					mcast_cleanup();

  					net_start_again();

  					return;
  				}

  				tftp_prev_block = tftp_cur_block;

  			}
  		}
  #endif

  		tftp_send();

  #ifdef CONFIG_MCAST_TFTP

  		if (tftp_mcast_active) {
  			if (tftp_mcast_master_client &&
  			    (tftp_cur_block >= tftp_mcast_ending_block)) {

  				puts("
  Multicast tftp done
  ");

  				mcast_cleanup();

  				net_set_state(NETLOOP_SUCCESS);

  			}

  		} else

  #endif

  		if (len < tftp_block_size)

  			tftp_complete();

  		break;
  
  	case TFTP_ERROR:

  		printf("
  TFTP error: '%s' (%d)
  ",

  		       pkt + 2, ntohs(*(__be16 *)pkt));

  		switch (ntohs(*(__be16 *)pkt)) {

  		case TFTP_ERR_FILE_NOT_FOUND:
  		case TFTP_ERR_ACCESS_DENIED:
  			puts("Not retrying...
  ");
  			eth_halt();

  			net_set_state(NETLOOP_FAIL);

  			break;
  		case TFTP_ERR_UNDEFINED:
  		case TFTP_ERR_DISK_FULL:
  		case TFTP_ERR_UNEXPECTED_OPCODE:
  		case TFTP_ERR_UNKNOWN_TRANSFER_ID:
  		case TFTP_ERR_FILE_ALREADY_EXISTS:
  		default:
  			puts("Starting again
  
  ");

  #ifdef CONFIG_MCAST_TFTP

  			mcast_cleanup();

  #endif

  			net_start_again();

  			break;
  		}

  		break;
  	}
  }

  static void tftp_timeout_handler(void)

  {

  	if (++timeout_count > timeout_count_max) {

  		restart("Retry count exceeded");

  	} else {

  		puts("T ");

  		net_set_timeout_handler(timeout_ms, tftp_timeout_handler);

  		if (tftp_state != STATE_RECV_WRQ)
  			tftp_send();

  	}
  }

  void tftp_start(enum proto_t protocol)

  {

  #if CONFIG_NET_TFTP_VARS

  	char *ep;             /* Environment pointer */

  	/*
  	 * Allow the user to choose TFTP blocksize and timeout.
  	 * TFTP protocol has a minimal timeout of 1 second.
  	 */

  	ep = env_get("tftpblocksize");

  	if (ep != NULL)

  		tftp_block_size_option = simple_strtol(ep, NULL, 10);

  	ep = env_get("tftptimeout");

  	if (ep != NULL)

  		timeout_ms = simple_strtol(ep, NULL, 10);

  	if (timeout_ms < 1000) {
  		printf("TFTP timeout (%ld ms) too low, set min = 1000 ms
  ",

  		       timeout_ms);

  		timeout_ms = 1000;

  	}

  	ep = env_get("tftptimeoutcountmax");

  	if (ep != NULL)
  		tftp_timeout_count_max = simple_strtol(ep, NULL, 10);
  
  	if (tftp_timeout_count_max < 0) {
  		printf("TFTP timeout count max (%d ms) negative, set to 0
  ",
  		       tftp_timeout_count_max);
  		tftp_timeout_count_max = 0;
  	}
  #endif

  	debug("TFTP blocksize = %i, timeout = %ld ms
  ",

  	      tftp_block_size_option, timeout_ms);

  	tftp_remote_ip = net_server_ip;

  	if (net_boot_file_name[0] == '\0') {

  		sprintf(default_filename, "%02X%02X%02X%02X.img",

  			net_ip.s_addr & 0xFF,
  			(net_ip.s_addr >>  8) & 0xFF,
  			(net_ip.s_addr >> 16) & 0xFF,
  			(net_ip.s_addr >> 24) & 0xFF);

  		strncpy(tftp_filename, default_filename, DEFAULT_NAME_LEN);
  		tftp_filename[DEFAULT_NAME_LEN - 1] = 0;

  		printf("*** Warning: no boot file name; using '%s'
  ",

  		       tftp_filename);

  	} else {

  		char *p = strchr(net_boot_file_name, ':');

  
  		if (p == NULL) {

  			strncpy(tftp_filename, net_boot_file_name, MAX_LEN);

  			tftp_filename[MAX_LEN - 1] = 0;

  		} else {

  			tftp_remote_ip = string_to_ip(net_boot_file_name);

  			strncpy(tftp_filename, p + 1, MAX_LEN);

  			tftp_filename[MAX_LEN - 1] = 0;

  		}

  	}

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

  	printf("TFTP %s server %pI4; our IP address is %pI4",

  #ifdef CONFIG_CMD_TFTPPUT
  	       protocol == TFTPPUT ? "to" : "from",
  #else

  	       "from",

  #endif

  	       &tftp_remote_ip, &net_ip);

  
  	/* Check if we need to send across this subnet */

  	if (net_gateway.s_addr && net_netmask.s_addr) {
  		struct in_addr our_net;
  		struct in_addr remote_net;
  
  		our_net.s_addr = net_ip.s_addr & net_netmask.s_addr;
  		remote_net.s_addr = tftp_remote_ip.s_addr & net_netmask.s_addr;
  		if (our_net.s_addr != remote_net.s_addr)
  			printf("; sending through gateway %pI4", &net_gateway);

  	}

  	putc('
  ');

  	printf("Filename '%s'.", tftp_filename);

  	if (net_boot_file_expected_size_in_blocks) {
  		printf(" Size is 0x%x Bytes = ",
  		       net_boot_file_expected_size_in_blocks << 9);
  		print_size(net_boot_file_expected_size_in_blocks << 9, "");

  	}

  	putc('
  ');

  #ifdef CONFIG_CMD_TFTPPUT

  	tftp_put_active = (protocol == TFTPPUT);
  	if (tftp_put_active) {

  		printf("Save address: 0x%lx
  ", save_addr);
  		printf("Save size:    0x%lx
  ", save_size);

  		net_boot_file_size = save_size;

  		puts("Saving: *\b");

  		tftp_state = STATE_SEND_WRQ;

  		new_transfer();
  	} else
  #endif
  	{
  		printf("Load address: 0x%lx
  ", load_addr);
  		puts("Loading: *\b");

  		tftp_state = STATE_SEND_RRQ;

  #ifdef CONFIG_CMD_BOOTEFI

  		efi_set_bootdev("Net", "", tftp_filename);

  #endif

  	}

  	time_start = get_timer(0);

  	timeout_count_max = tftp_timeout_count_max;

  	net_set_timeout_handler(timeout_ms, tftp_timeout_handler);

  	net_set_udp_handler(tftp_handler);

  #ifdef CONFIG_CMD_TFTPPUT

  	net_set_icmp_handler(icmp_handler);

  #endif

  	tftp_remote_port = WELL_KNOWN_PORT;
  	timeout_count = 0;

  	/* Use a pseudo-random port unless a specific port is set */

  	tftp_our_port = 1024 + (get_timer(0) % 3072);

  #ifdef CONFIG_TFTP_PORT

  	ep = env_get("tftpdstp");

  	if (ep != NULL)

  		tftp_remote_port = simple_strtol(ep, NULL, 10);

  	ep = env_get("tftpsrcp");

  	if (ep != NULL)

  		tftp_our_port = simple_strtol(ep, NULL, 10);

  #endif

  	tftp_cur_block = 0;

  	/* zero out server ether in case the server ip has changed */

  	memset(net_server_ethaddr, 0, 6);

  	/* Revert tftp_block_size to dflt */
  	tftp_block_size = TFTP_BLOCK_SIZE;

  #ifdef CONFIG_MCAST_TFTP

  	mcast_cleanup();

  #endif

  #ifdef CONFIG_TFTP_TSIZE

  	tftp_tsize = 0;
  	tftp_tsize_num_hash = 0;

  #endif

  	tftp_send();

  }

  #ifdef CONFIG_CMD_TFTPSRV

  void tftp_start_server(void)

  {
  	tftp_filename[0] = 0;

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

  	printf("Listening for TFTP transfer on %pI4
  ", &net_ip);

  	printf("Load address: 0x%lx
  ", load_addr);
  
  	puts("Loading: *\b");

  	timeout_count_max = tftp_timeout_count_max;

  	timeout_count = 0;
  	timeout_ms = TIMEOUT;

  	net_set_timeout_handler(timeout_ms, tftp_timeout_handler);

  	/* Revert tftp_block_size to dflt */
  	tftp_block_size = TFTP_BLOCK_SIZE;
  	tftp_cur_block = 0;
  	tftp_our_port = WELL_KNOWN_PORT;

  
  #ifdef CONFIG_TFTP_TSIZE

  	tftp_tsize = 0;
  	tftp_tsize_num_hash = 0;

  #endif

  	tftp_state = STATE_RECV_WRQ;

  	net_set_udp_handler(tftp_handler);

  
  	/* zero out server ether in case the server ip has changed */

  	memset(net_server_ethaddr, 0, 6);

  }
  #endif /* CONFIG_CMD_TFTPSRV */

  #ifdef CONFIG_MCAST_TFTP

  /*
   * Credits: atftp project.

   */

  /*
   * Pick up BcastAddr, Port, and whether I am [now] the master-client.

   * Frame:
   *    +-------+-----------+---+-------~~-------+---+
   *    |  opc  | multicast | 0 | addr, port, mc | 0 |
   *    +-------+-----------+---+-------~~-------+---+
   * The multicast addr/port becomes what I listen to, and if 'mc' is '1' then
   * I am the new master-client so must send ACKs to DataBlocks.  If I am not
   * master-client, I'm a passive client, gathering what DataBlocks I may and
   * making note of which ones I got in my bitmask.
   * In theory, I never go from master->passive..
   * .. this comes in with pkt already pointing just past opc
   */
  static void parse_multicast_oack(char *pkt, int len)
  {

  	int i;

  	struct in_addr addr;

  	char *mc_adr;
  	char *port;
  	char *mc;

  	mc_adr = NULL;
  	port = NULL;
  	mc = NULL;

  	/* march along looking for 'multicast\0', which has to start at least
  	 * 14 bytes back from the end.
  	 */

  	for (i = 0; i < len - 14; i++)
  		if (strcmp(pkt + i, "multicast") == 0)

  			break;

  	if (i >= (len - 14)) /* non-Multicast OACK, ign. */

  		return;

  	i += 10; /* strlen multicast */

  	mc_adr = pkt + i;

  	for (; i < len; i++) {

  		if (*(pkt + i) == ',') {
  			*(pkt + i) = '\0';

  			if (port) {

  				mc = pkt + i + 1;

  				break;
  			} else {

  				port = pkt + i + 1;

  			}
  		}
  	}

  	if (!port || !mc_adr || !mc)
  		return;

  	if (tftp_mcast_active && tftp_mcast_master_client) {

  		printf("I got a OACK as master Client, WRONG!
  ");

  		return;
  	}
  	/* ..I now accept packets destined for this MCAST addr, port */

  	if (!tftp_mcast_active) {
  		if (tftp_mcast_bitmap) {

  			printf("Internal failure! no mcast.
  ");

  			free(tftp_mcast_bitmap);
  			tftp_mcast_bitmap = NULL;
  			tftp_mcast_disabled = 1;
  			return;

  		}
  		/* I malloc instead of pre-declare; so that if the file ends

  		 * up being too big for this bitmap I can retry
  		 */

  		tftp_mcast_bitmap = malloc(tftp_mcast_bitmap_size);
  		if (!tftp_mcast_bitmap) {
  			printf("No bitmap, no multicast. Sorry.
  ");
  			tftp_mcast_disabled = 1;

  			return;
  		}

  		memset(tftp_mcast_bitmap, 0, tftp_mcast_bitmap_size);
  		tftp_mcast_prev_hole = 0;
  		tftp_mcast_active = 1;

  	}
  	addr = string_to_ip(mc_adr);

  	if (net_mcast_addr.s_addr != addr.s_addr) {
  		if (net_mcast_addr.s_addr)
  			eth_mcast_join(net_mcast_addr, 0);
  		net_mcast_addr = addr;
  		if (eth_mcast_join(net_mcast_addr, 1)) {

  			printf("Fail to set mcast, revert to TFTP
  ");

  			tftp_mcast_disabled = 1;

  			mcast_cleanup();

  			net_start_again();

  		}
  	}

  	tftp_mcast_master_client = simple_strtoul((char *)mc, NULL, 10);
  	tftp_mcast_port = (unsigned short)simple_strtoul(port, NULL, 10);
  	printf("Multicast: %s:%d [%d]
  ", mc_adr, tftp_mcast_port,
  	       tftp_mcast_master_client);

  	return;
  }
  
  #endif /* Multicast TFTP */