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

#include <common.h>
#include <command.h>
#include <net.h>
#include <driver.h>
#include <clock.h>
#include <fs.h>
#include <errno.h>
#include "tftp.h"
#include "bootp.h"

#undef	ET_DEBUG

#define WELL_KNOWN_PORT	69		/* Well known TFTP port #		*/
#define TIMEOUT		5		/* Seconds to timeout for a lost pkt	*/
#ifndef	CONFIG_NET_RETRY_COUNT
# define TIMEOUT_COUNT	10		/* # of timeouts before giving up  */
#else
# define TIMEOUT_COUNT  (CONFIG_NET_RETRY_COUNT * 2)
#endif
					/* (for checking the image size)	*/
#define HASHES_PER_LINE	65		/* Number of "loading" hashes per line	*/

/*
 *	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 int	TftpServerPort;		/* The UDP port at their end		*/
static int	TftpOurPort;		/* The UDP port at our end		*/
static int	TftpTimeoutCount;
static ulong	TftpBlock;		/* packet sequence number		*/
static ulong	TftpLastBlock;		/* last packet sequence number received */
static ulong	TftpBlockWrap;		/* count of sequence number wraparounds */
static ulong	TftpBlockWrapOffset;	/* memory offset due to wrapping	*/
static int	TftpState;

#define STATE_RRQ	1
#define STATE_DATA	2
#define STATE_TOO_LARGE	3
#define STATE_BAD_MAGIC	4
#define STATE_OACK	5

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

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

extern int net_store_fd;

static int
store_block (unsigned block, uchar * src, unsigned len)
{
	ulong offset = block * TFTP_BLOCK_SIZE + TftpBlockWrapOffset;
	ulong newsize = offset + len;
	int ret;

	ret = write(net_store_fd, src, len);
	if (ret < 0)
		return ret;

	if (NetBootFileXferSize < newsize)
		NetBootFileXferSize = newsize;
	return 0;
}

static void TftpSend (void);
static void TftpTimeout (void);

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

static void
TftpSend (void)
{
	volatile uchar *	pkt;
	volatile uchar *	xp;
	int			len = 0;
	volatile ushort *s;

	/*
	 *	We will always be sending some sort of packet, so
	 *	cobble together the packet headers now.
	 */
	pkt = NetTxPacket + NetEthHdrSize() + IP_HDR_SIZE;

	switch (TftpState) {

	case STATE_RRQ:
		xp = pkt;
		s = (ushort *)pkt;
		*s++ = htons(TFTP_RRQ);
		pkt = (uchar *)s;
		pkt += sprintf((uchar *)pkt, "%s%coctet%ctimeout%c%d",
				tftp_filename, 0, 0, 0, TIMEOUT) + 1;
		len = pkt - xp;
		break;

	case STATE_DATA:
	case STATE_OACK:
		xp = pkt;
		s = (ushort *)pkt;
		*s++ = htons(TFTP_ACK);
		*s++ = htons(TftpBlock);
		pkt = (uchar *)s;
		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;
	}

	NetSendUDPPacket(NetServerEther, NetServerIP, TftpServerPort, TftpOurPort, len);
}


static void
TftpHandler (uchar * pkt, unsigned dest, unsigned src, unsigned len)
{
	ushort proto;
	ushort *s;

	if (dest != TftpOurPort) {
		return;
	}
	if (TftpState != STATE_RRQ && src != TftpServerPort) {
		return;
	}

	if (len < 2) {
		return;
	}
	len -= 2;
	/* warning: don't use increment (++) in ntohs() macros!! */
	s = (ushort *)pkt;
	proto = *s++;
	pkt = (uchar *)s;
	switch (ntohs(proto)) {

	case TFTP_RRQ:
	case TFTP_WRQ:
	case TFTP_ACK:
		break;
	default:
		break;

	case TFTP_OACK:
#ifdef ET_DEBUG
		printf("Got OACK: %s %s\n", pkt, pkt+strlen(pkt)+1);
#endif
		TftpState = STATE_OACK;
		TftpServerPort = src;
		TftpSend (); /* Send ACK */
		break;
	case TFTP_DATA:
		if (len < 2)
			return;
		len -= 2;
		TftpBlock = ntohs(*(ushort *)pkt);

		/*
		 * 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 (TftpBlock == 0) {
			TftpBlockWrap++;
			TftpBlockWrapOffset += TFTP_BLOCK_SIZE * TFTP_SEQUENCE_SIZE;
			printf ("\n\t %lu MB received\n\t ", TftpBlockWrapOffset>>20);
		} else {
			if (((TftpBlock - 1) % 10) == 0) {
				putchar('#');
			} else if ((TftpBlock % (10 * HASHES_PER_LINE)) == 0) {
				puts ("\n\t ");
			}
		}

#ifdef ET_DEBUG
		if (TftpState == STATE_RRQ) {
			puts ("Server did not acknowledge timeout option!\n");
		}
#endif

		if (TftpState == STATE_RRQ || TftpState == STATE_OACK) {
			/* first block received */
			TftpState = STATE_DATA;
			TftpServerPort = src;
			TftpLastBlock = 0;
			TftpBlockWrap = 0;
			TftpBlockWrapOffset = 0;

			if (TftpBlock != 1) {	/* Assertion */
				printf ("\nTFTP error: "
					"First block is not block 1 (%ld)\n"
					"Starting again\n\n",
					TftpBlock);
				NetStartAgain ();
				break;
			}
		}

		if (TftpBlock == TftpLastBlock) {
			/*
			 *	Same block again; ignore it.
			 */
			break;
		}

		TftpLastBlock = TftpBlock;
		NetSetTimeout (TIMEOUT * SECOND, TftpTimeout);

		if (store_block (TftpBlock - 1, pkt + 2, len) < 0) {
			perror("write");
			NetState = NETLOOP_FAIL;
			return;
		}

		/*
		 *	Acknoledge the block just received, which will prompt
		 *	the server for the next one.
		 */
		TftpSend ();

		if (len < TFTP_BLOCK_SIZE) {
			/*
			 *	We received the whole thing.  Try to
			 *	run it.
			 */
			puts ("\ndone\n");
			NetState = NETLOOP_SUCCESS;
		}
		break;

	case TFTP_ERROR:
		printf ("\nTFTP error: '%s' (%d)\n",
					pkt + 2, ntohs(*(ushort *)pkt));
		puts ("Starting again\n\n");
		NetStartAgain ();
		break;
	}
}


static void
TftpTimeout (void)
{
	if (++TftpTimeoutCount > TIMEOUT_COUNT) {
		puts ("\nRetry count exceeded; starting again\n");
		NetStartAgain ();
	} else {
		puts ("T ");
		NetSetTimeout (TIMEOUT * SECOND, TftpTimeout);
		TftpSend ();
	}
}


void
TftpStart (void)
{
#ifdef CONFIG_TFTP_PORT
	char *ep;             /* Environment pointer */
#endif

	if (BootFile[0] == '\0') {
		sprintf(default_filename, "%02lX%02lX%02lX%02lX.img",
			NetOurIP & 0xFF,
			(NetOurIP >>  8) & 0xFF,
			(NetOurIP >> 16) & 0xFF,
			(NetOurIP >> 24) & 0xFF	);
		tftp_filename = default_filename;

		printf ("*** Warning: no boot file name; using '%s'\n",
			tftp_filename);
	} else {
		tftp_filename = BootFile;
	}

	puts ("TFTP from server ");	print_IPaddr (NetServerIP);
	puts ("; our IP address is ");	print_IPaddr (NetOurIP);

	/* Check if we need to send across this subnet */
	if (NetOurGatewayIP && NetOurSubnetMask) {
	    IPaddr_t OurNet 	= NetOurIP    & NetOurSubnetMask;
	    IPaddr_t ServerNet 	= NetServerIP & NetOurSubnetMask;

	    if (OurNet != ServerNet) {
		puts ("; sending through gateway ");
		print_IPaddr (NetOurGatewayIP) ;
	    }
	}
	putchar('\n');

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

	if (NetBootFileSize)
		printf (" Size is 0x%x Bytes = %s",
			NetBootFileSize<<9,
			size_human_readable(NetBootFileSize<<9));

	puts ("\nLoading: *\b");

	NetSetTimeout (TIMEOUT * SECOND, TftpTimeout);
	NetSetHandler (TftpHandler);

	TftpServerPort = WELL_KNOWN_PORT;
	TftpTimeoutCount = 0;
	TftpState = STATE_RRQ;
	/* Use a pseudo-random port unless a specific port is set */
	TftpOurPort = 1024 + ((unsigned int)get_time_ns() % 3072);
#ifdef CONFIG_TFTP_PORT
	if ((ep = getenv("tftpdstp")) != NULL) {
		TftpServerPort = simple_strtol(ep, NULL, 10);
	}
	if ((ep = getenv("tftpsrcp")) != NULL) {
		TftpOurPort= simple_strtol(ep, NULL, 10);
	}
#endif
	TftpBlock = 0;

	/* zero out server ether in case the server ip has changed */
	memset(NetServerEther, 0, 6);

	TftpSend ();
}