xref: /openbmc/u-boot/net/tftp.c (revision a2ee7f07)
1 /*
2  * Copyright 1994, 1995, 2000 Neil Russell.
3  * (See License)
4  * Copyright 2000, 2001 DENX Software Engineering, Wolfgang Denk, wd@denx.de
5  * Copyright 2011 Comelit Group SpA,
6  *                Luca Ceresoli <luca.ceresoli@comelit.it>
7  */
8 
9 #include <common.h>
10 #include <command.h>
11 #include <net.h>
12 #include "tftp.h"
13 #include "bootp.h"
14 
15 /* Well known TFTP port # */
16 #define WELL_KNOWN_PORT	69
17 /* Millisecs to timeout for lost pkt */
18 #define TIMEOUT		5000UL
19 #ifndef	CONFIG_NET_RETRY_COUNT
20 /* # of timeouts before giving up */
21 # define TIMEOUT_COUNT	10
22 #else
23 # define TIMEOUT_COUNT  (CONFIG_NET_RETRY_COUNT * 2)
24 #endif
25 /* Number of "loading" hashes per line (for checking the image size) */
26 #define HASHES_PER_LINE	65
27 
28 /*
29  *	TFTP operations.
30  */
31 #define TFTP_RRQ	1
32 #define TFTP_WRQ	2
33 #define TFTP_DATA	3
34 #define TFTP_ACK	4
35 #define TFTP_ERROR	5
36 #define TFTP_OACK	6
37 
38 static ulong TftpTimeoutMSecs = TIMEOUT;
39 static int TftpTimeoutCountMax = TIMEOUT_COUNT;
40 
41 /*
42  * These globals govern the timeout behavior when attempting a connection to a
43  * TFTP server. TftpRRQTimeoutMSecs specifies the number of milliseconds to
44  * wait for the server to respond to initial connection. Second global,
45  * TftpRRQTimeoutCountMax, gives the number of such connection retries.
46  * TftpRRQTimeoutCountMax must be non-negative and TftpRRQTimeoutMSecs must be
47  * positive. The globals are meant to be set (and restored) by code needing
48  * non-standard timeout behavior when initiating a TFTP transfer.
49  */
50 ulong TftpRRQTimeoutMSecs = TIMEOUT;
51 int TftpRRQTimeoutCountMax = TIMEOUT_COUNT;
52 
53 enum {
54 	TFTP_ERR_UNDEFINED           = 0,
55 	TFTP_ERR_FILE_NOT_FOUND      = 1,
56 	TFTP_ERR_ACCESS_DENIED       = 2,
57 	TFTP_ERR_DISK_FULL           = 3,
58 	TFTP_ERR_UNEXPECTED_OPCODE   = 4,
59 	TFTP_ERR_UNKNOWN_TRANSFER_ID  = 5,
60 	TFTP_ERR_FILE_ALREADY_EXISTS = 6,
61 };
62 
63 static IPaddr_t TftpRemoteIP;
64 /* The UDP port at their end */
65 static int	TftpRemotePort;
66 /* The UDP port at our end */
67 static int	TftpOurPort;
68 static int	TftpTimeoutCount;
69 /* packet sequence number */
70 static ulong	TftpBlock;
71 /* last packet sequence number received */
72 static ulong	TftpLastBlock;
73 /* count of sequence number wraparounds */
74 static ulong	TftpBlockWrap;
75 /* memory offset due to wrapping */
76 static ulong	TftpBlockWrapOffset;
77 static int	TftpState;
78 #ifdef CONFIG_TFTP_TSIZE
79 /* The file size reported by the server */
80 static int	TftpTsize;
81 /* The number of hashes we printed */
82 static short	TftpNumchars;
83 #endif
84 #ifdef CONFIG_CMD_TFTPPUT
85 static int	TftpWriting;	/* 1 if writing, else 0 */
86 static int	TftpFinalBlock;	/* 1 if we have sent the last block */
87 #else
88 #define TftpWriting	0
89 #endif
90 
91 #define STATE_SEND_RRQ	1
92 #define STATE_DATA	2
93 #define STATE_TOO_LARGE	3
94 #define STATE_BAD_MAGIC	4
95 #define STATE_OACK	5
96 #define STATE_RECV_WRQ	6
97 #define STATE_SEND_WRQ	7
98 
99 /* default TFTP block size */
100 #define TFTP_BLOCK_SIZE		512
101 /* sequence number is 16 bit */
102 #define TFTP_SEQUENCE_SIZE	((ulong)(1<<16))
103 
104 #define DEFAULT_NAME_LEN	(8 + 4 + 1)
105 static char default_filename[DEFAULT_NAME_LEN];
106 
107 #ifndef CONFIG_TFTP_FILE_NAME_MAX_LEN
108 #define MAX_LEN 128
109 #else
110 #define MAX_LEN CONFIG_TFTP_FILE_NAME_MAX_LEN
111 #endif
112 
113 static char tftp_filename[MAX_LEN];
114 
115 #ifdef CONFIG_SYS_DIRECT_FLASH_TFTP
116 extern flash_info_t flash_info[];
117 #endif
118 
119 /* 512 is poor choice for ethernet, MTU is typically 1500.
120  * Minus eth.hdrs thats 1468.  Can get 2x better throughput with
121  * almost-MTU block sizes.  At least try... fall back to 512 if need be.
122  * (but those using CONFIG_IP_DEFRAG may want to set a larger block in cfg file)
123  */
124 #ifdef CONFIG_TFTP_BLOCKSIZE
125 #define TFTP_MTU_BLOCKSIZE CONFIG_TFTP_BLOCKSIZE
126 #else
127 #define TFTP_MTU_BLOCKSIZE 1468
128 #endif
129 
130 static unsigned short TftpBlkSize = TFTP_BLOCK_SIZE;
131 static unsigned short TftpBlkSizeOption = TFTP_MTU_BLOCKSIZE;
132 
133 #ifdef CONFIG_MCAST_TFTP
134 #include <malloc.h>
135 #define MTFTP_BITMAPSIZE	0x1000
136 static unsigned *Bitmap;
137 static int PrevBitmapHole, Mapsize = MTFTP_BITMAPSIZE;
138 static uchar ProhibitMcast, MasterClient;
139 static uchar Multicast;
140 extern IPaddr_t Mcast_addr;
141 static int Mcast_port;
142 static ulong TftpEndingBlock; /* can get 'last' block before done..*/
143 
144 static void parse_multicast_oack(char *pkt, int len);
145 
146 static void
147 mcast_cleanup(void)
148 {
149 	if (Mcast_addr)
150 		eth_mcast_join(Mcast_addr, 0);
151 	if (Bitmap)
152 		free(Bitmap);
153 	Bitmap = NULL;
154 	Mcast_addr = Multicast = Mcast_port = 0;
155 	TftpEndingBlock = -1;
156 }
157 
158 #endif	/* CONFIG_MCAST_TFTP */
159 
160 static __inline__ void
161 store_block(unsigned block, uchar *src, unsigned len)
162 {
163 	ulong offset = block * TftpBlkSize + TftpBlockWrapOffset;
164 	ulong newsize = offset + len;
165 #ifdef CONFIG_SYS_DIRECT_FLASH_TFTP
166 	int i, rc = 0;
167 
168 	for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; i++) {
169 		/* start address in flash? */
170 		if (flash_info[i].flash_id == FLASH_UNKNOWN)
171 			continue;
172 		if (load_addr + offset >= flash_info[i].start[0]) {
173 			rc = 1;
174 			break;
175 		}
176 	}
177 
178 	if (rc) { /* Flash is destination for this packet */
179 		rc = flash_write((char *)src, (ulong)(load_addr+offset), len);
180 		if (rc) {
181 			flash_perror(rc);
182 			NetState = NETLOOP_FAIL;
183 			return;
184 		}
185 	}
186 	else
187 #endif /* CONFIG_SYS_DIRECT_FLASH_TFTP */
188 	{
189 		(void)memcpy((void *)(load_addr + offset), src, len);
190 	}
191 #ifdef CONFIG_MCAST_TFTP
192 	if (Multicast)
193 		ext2_set_bit(block, Bitmap);
194 #endif
195 
196 	if (NetBootFileXferSize < newsize)
197 		NetBootFileXferSize = newsize;
198 }
199 
200 /* Clear our state ready for a new transfer */
201 static void new_transfer(void)
202 {
203 	TftpLastBlock = 0;
204 	TftpBlockWrap = 0;
205 	TftpBlockWrapOffset = 0;
206 #ifdef CONFIG_CMD_TFTPPUT
207 	TftpFinalBlock = 0;
208 #endif
209 }
210 
211 #ifdef CONFIG_CMD_TFTPPUT
212 /**
213  * Load the next block from memory to be sent over tftp.
214  *
215  * @param block	Block number to send
216  * @param dst	Destination buffer for data
217  * @param len	Number of bytes in block (this one and every other)
218  * @return number of bytes loaded
219  */
220 static int load_block(unsigned block, uchar *dst, unsigned len)
221 {
222 	/* We may want to get the final block from the previous set */
223 	ulong offset = ((int)block - 1) * len + TftpBlockWrapOffset;
224 	ulong tosend = len;
225 
226 	tosend = min(NetBootFileXferSize - offset, tosend);
227 	(void)memcpy(dst, (void *)(save_addr + offset), tosend);
228 	debug("%s: block=%d, offset=%ld, len=%d, tosend=%ld\n", __func__,
229 		block, offset, len, tosend);
230 	return tosend;
231 }
232 #endif
233 
234 static void TftpSend(void);
235 static void TftpTimeout(void);
236 
237 /**********************************************************************/
238 
239 static void show_block_marker(void)
240 {
241 #ifdef CONFIG_TFTP_TSIZE
242 	if (TftpTsize) {
243 		ulong pos = TftpBlock * TftpBlkSize + TftpBlockWrapOffset;
244 
245 		while (TftpNumchars < pos * 50 / TftpTsize) {
246 			putc('#');
247 			TftpNumchars++;
248 		}
249 	} else
250 #endif
251 	{
252 		if (((TftpBlock - 1) % 10) == 0)
253 			putc('#');
254 		else if ((TftpBlock % (10 * HASHES_PER_LINE)) == 0)
255 			puts("\n\t ");
256 	}
257 }
258 
259 /**
260  * restart the current transfer due to an error
261  *
262  * @param msg	Message to print for user
263  */
264 static void restart(const char *msg)
265 {
266 	printf("\n%s; starting again\n", msg);
267 #ifdef CONFIG_MCAST_TFTP
268 	mcast_cleanup();
269 #endif
270 	NetStartAgain();
271 }
272 
273 /*
274  * Check if the block number has wrapped, and update progress
275  *
276  * TODO: The egregious use of global variables in this file should be tidied.
277  */
278 static void update_block_number(void)
279 {
280 	/*
281 	 * RFC1350 specifies that the first data packet will
282 	 * have sequence number 1. If we receive a sequence
283 	 * number of 0 this means that there was a wrap
284 	 * around of the (16 bit) counter.
285 	 */
286 	if (TftpBlock == 0) {
287 		TftpBlockWrap++;
288 		TftpBlockWrapOffset += TftpBlkSize * TFTP_SEQUENCE_SIZE;
289 		TftpTimeoutCount = 0; /* we've done well, reset thhe timeout */
290 	} else {
291 		show_block_marker();
292 	}
293 }
294 
295 /* The TFTP get or put is complete */
296 static void tftp_complete(void)
297 {
298 #ifdef CONFIG_TFTP_TSIZE
299 	/* Print hash marks for the last packet received */
300 	while (TftpTsize && TftpNumchars < 49) {
301 		putc('#');
302 		TftpNumchars++;
303 	}
304 #endif
305 	puts("\ndone\n");
306 	NetState = NETLOOP_SUCCESS;
307 }
308 
309 static void
310 TftpSend(void)
311 {
312 	uchar *pkt;
313 	volatile uchar *xp;
314 	int		len = 0;
315 	volatile ushort *s;
316 
317 #ifdef CONFIG_MCAST_TFTP
318 	/* Multicast TFTP.. non-MasterClients do not ACK data. */
319 	if (Multicast
320 	 && (TftpState == STATE_DATA)
321 	 && (MasterClient == 0))
322 		return;
323 #endif
324 	/*
325 	 *	We will always be sending some sort of packet, so
326 	 *	cobble together the packet headers now.
327 	 */
328 	pkt = (uchar *)(NetTxPacket + NetEthHdrSize() + IP_HDR_SIZE);
329 
330 	switch (TftpState) {
331 	case STATE_SEND_RRQ:
332 	case STATE_SEND_WRQ:
333 		xp = pkt;
334 		s = (ushort *)pkt;
335 #ifdef CONFIG_CMD_TFTPPUT
336 		*s++ = htons(TftpState == STATE_SEND_RRQ ? TFTP_RRQ :
337 			TFTP_WRQ);
338 #else
339 		*s++ = htons(TFTP_RRQ);
340 #endif
341 		pkt = (uchar *)s;
342 		strcpy((char *)pkt, tftp_filename);
343 		pkt += strlen(tftp_filename) + 1;
344 		strcpy((char *)pkt, "octet");
345 		pkt += 5 /*strlen("octet")*/ + 1;
346 		strcpy((char *)pkt, "timeout");
347 		pkt += 7 /*strlen("timeout")*/ + 1;
348 		sprintf((char *)pkt, "%lu", TftpTimeoutMSecs / 1000);
349 		debug("send option \"timeout %s\"\n", (char *)pkt);
350 		pkt += strlen((char *)pkt) + 1;
351 #ifdef CONFIG_TFTP_TSIZE
352 		pkt += sprintf((char *)pkt, "tsize%c%lu%c",
353 				0, NetBootFileXferSize, 0);
354 #endif
355 		/* try for more effic. blk size */
356 		pkt += sprintf((char *)pkt, "blksize%c%d%c",
357 				0, TftpBlkSizeOption, 0);
358 #ifdef CONFIG_MCAST_TFTP
359 		/* Check all preconditions before even trying the option */
360 		if (!ProhibitMcast
361 		 && (Bitmap = malloc(Mapsize))
362 		 && eth_get_dev()->mcast) {
363 			free(Bitmap);
364 			Bitmap = NULL;
365 			pkt += sprintf((char *)pkt, "multicast%c%c", 0, 0);
366 		}
367 #endif /* CONFIG_MCAST_TFTP */
368 		len = pkt - xp;
369 		break;
370 
371 	case STATE_OACK:
372 #ifdef CONFIG_MCAST_TFTP
373 		/* My turn!  Start at where I need blocks I missed.*/
374 		if (Multicast)
375 			TftpBlock = ext2_find_next_zero_bit(Bitmap,
376 							    (Mapsize*8), 0);
377 		/*..falling..*/
378 #endif
379 
380 	case STATE_RECV_WRQ:
381 	case STATE_DATA:
382 		xp = pkt;
383 		s = (ushort *)pkt;
384 		s[0] = htons(TFTP_ACK);
385 		s[1] = htons(TftpBlock);
386 		pkt = (uchar *)(s + 2);
387 #ifdef CONFIG_CMD_TFTPPUT
388 		if (TftpWriting) {
389 			int toload = TftpBlkSize;
390 			int loaded = load_block(TftpBlock, pkt, toload);
391 
392 			s[0] = htons(TFTP_DATA);
393 			pkt += loaded;
394 			TftpFinalBlock = (loaded < toload);
395 		}
396 #endif
397 		len = pkt - xp;
398 		break;
399 
400 	case STATE_TOO_LARGE:
401 		xp = pkt;
402 		s = (ushort *)pkt;
403 		*s++ = htons(TFTP_ERROR);
404 			*s++ = htons(3);
405 
406 		pkt = (uchar *)s;
407 		strcpy((char *)pkt, "File too large");
408 		pkt += 14 /*strlen("File too large")*/ + 1;
409 		len = pkt - xp;
410 		break;
411 
412 	case STATE_BAD_MAGIC:
413 		xp = pkt;
414 		s = (ushort *)pkt;
415 		*s++ = htons(TFTP_ERROR);
416 		*s++ = htons(2);
417 		pkt = (uchar *)s;
418 		strcpy((char *)pkt, "File has bad magic");
419 		pkt += 18 /*strlen("File has bad magic")*/ + 1;
420 		len = pkt - xp;
421 		break;
422 	}
423 
424 	NetSendUDPPacket(NetServerEther, TftpRemoteIP, TftpRemotePort,
425 			 TftpOurPort, len);
426 }
427 
428 #ifdef CONFIG_CMD_TFTPPUT
429 static void icmp_handler(unsigned type, unsigned code, unsigned dest,
430 			 IPaddr_t sip, unsigned src, uchar *pkt, unsigned len)
431 {
432 	if (type == ICMP_NOT_REACH && code == ICMP_NOT_REACH_PORT) {
433 		/* Oh dear the other end has gone away */
434 		restart("TFTP server died");
435 	}
436 }
437 #endif
438 
439 static void
440 TftpHandler(uchar *pkt, unsigned dest, IPaddr_t sip, unsigned src,
441 	    unsigned len)
442 {
443 	ushort proto;
444 	ushort *s;
445 	int i;
446 
447 	if (dest != TftpOurPort) {
448 #ifdef CONFIG_MCAST_TFTP
449 		if (Multicast
450 		 && (!Mcast_port || (dest != Mcast_port)))
451 #endif
452 			return;
453 	}
454 	if (TftpState != STATE_SEND_RRQ && src != TftpRemotePort &&
455 	    TftpState != STATE_RECV_WRQ && TftpState != STATE_SEND_WRQ)
456 		return;
457 
458 	if (len < 2)
459 		return;
460 	len -= 2;
461 	/* warning: don't use increment (++) in ntohs() macros!! */
462 	s = (ushort *)pkt;
463 	proto = *s++;
464 	pkt = (uchar *)s;
465 	switch (ntohs(proto)) {
466 
467 	case TFTP_RRQ:
468 		break;
469 
470 	case TFTP_ACK:
471 #ifdef CONFIG_CMD_TFTPPUT
472 		if (TftpWriting) {
473 			if (TftpFinalBlock) {
474 				tftp_complete();
475 			} else {
476 				/*
477 				 * Move to the next block. We want our block
478 				 * count to wrap just like the other end!
479 				 */
480 				int block = ntohs(*s);
481 				int ack_ok = (TftpBlock == block);
482 
483 				TftpBlock = (unsigned short)(block + 1);
484 				update_block_number();
485 				if (ack_ok)
486 					TftpSend(); /* Send next data block */
487 			}
488 		}
489 #endif
490 		break;
491 
492 	default:
493 		break;
494 
495 #ifdef CONFIG_CMD_TFTPSRV
496 	case TFTP_WRQ:
497 		debug("Got WRQ\n");
498 		TftpRemoteIP = sip;
499 		TftpRemotePort = src;
500 		TftpOurPort = 1024 + (get_timer(0) % 3072);
501 		new_transfer();
502 		TftpSend(); /* Send ACK(0) */
503 		break;
504 #endif
505 
506 	case TFTP_OACK:
507 		debug("Got OACK: %s %s\n",
508 			pkt,
509 			pkt + strlen((char *)pkt) + 1);
510 		TftpState = STATE_OACK;
511 		TftpRemotePort = src;
512 		/*
513 		 * Check for 'blksize' option.
514 		 * Careful: "i" is signed, "len" is unsigned, thus
515 		 * something like "len-8" may give a *huge* number
516 		 */
517 		for (i = 0; i+8 < len; i++) {
518 			if (strcmp((char *)pkt+i, "blksize") == 0) {
519 				TftpBlkSize = (unsigned short)
520 					simple_strtoul((char *)pkt+i+8, NULL,
521 						       10);
522 				debug("Blocksize ack: %s, %d\n",
523 					(char *)pkt+i+8, TftpBlkSize);
524 			}
525 #ifdef CONFIG_TFTP_TSIZE
526 			if (strcmp((char *)pkt+i, "tsize") == 0) {
527 				TftpTsize = simple_strtoul((char *)pkt+i+6,
528 							   NULL, 10);
529 				debug("size = %s, %d\n",
530 					 (char *)pkt+i+6, TftpTsize);
531 			}
532 #endif
533 		}
534 #ifdef CONFIG_MCAST_TFTP
535 		parse_multicast_oack((char *)pkt, len-1);
536 		if ((Multicast) && (!MasterClient))
537 			TftpState = STATE_DATA;	/* passive.. */
538 		else
539 #endif
540 #ifdef CONFIG_CMD_TFTPPUT
541 		if (TftpWriting) {
542 			/* Get ready to send the first block */
543 			TftpState = STATE_DATA;
544 			TftpBlock++;
545 		}
546 #endif
547 		TftpSend(); /* Send ACK or first data block */
548 		break;
549 	case TFTP_DATA:
550 		if (len < 2)
551 			return;
552 		len -= 2;
553 		TftpBlock = ntohs(*(ushort *)pkt);
554 
555 		update_block_number();
556 
557 		if (TftpState == STATE_SEND_RRQ)
558 			debug("Server did not acknowledge timeout option!\n");
559 
560 		if (TftpState == STATE_SEND_RRQ || TftpState == STATE_OACK ||
561 		    TftpState == STATE_RECV_WRQ) {
562 			/* first block received */
563 			TftpState = STATE_DATA;
564 			TftpRemotePort = src;
565 			new_transfer();
566 
567 #ifdef CONFIG_MCAST_TFTP
568 			if (Multicast) { /* start!=1 common if mcast */
569 				TftpLastBlock = TftpBlock - 1;
570 			} else
571 #endif
572 			if (TftpBlock != 1) {	/* Assertion */
573 				printf("\nTFTP error: "
574 				       "First block is not block 1 (%ld)\n"
575 				       "Starting again\n\n",
576 					TftpBlock);
577 				NetStartAgain();
578 				break;
579 			}
580 		}
581 
582 		if (TftpBlock == TftpLastBlock) {
583 			/*
584 			 *	Same block again; ignore it.
585 			 */
586 			break;
587 		}
588 
589 		TftpLastBlock = TftpBlock;
590 		TftpTimeoutCountMax = TIMEOUT_COUNT;
591 		NetSetTimeout(TftpTimeoutMSecs, TftpTimeout);
592 
593 		store_block(TftpBlock - 1, pkt + 2, len);
594 
595 		/*
596 		 *	Acknowledge the block just received, which will prompt
597 		 *	the remote for the next one.
598 		 */
599 #ifdef CONFIG_MCAST_TFTP
600 		/* if I am the MasterClient, actively calculate what my next
601 		 * needed block is; else I'm passive; not ACKING
602 		 */
603 		if (Multicast) {
604 			if (len < TftpBlkSize)  {
605 				TftpEndingBlock = TftpBlock;
606 			} else if (MasterClient) {
607 				TftpBlock = PrevBitmapHole =
608 					ext2_find_next_zero_bit(
609 						Bitmap,
610 						(Mapsize*8),
611 						PrevBitmapHole);
612 				if (TftpBlock > ((Mapsize*8) - 1)) {
613 					printf("tftpfile too big\n");
614 					/* try to double it and retry */
615 					Mapsize <<= 1;
616 					mcast_cleanup();
617 					NetStartAgain();
618 					return;
619 				}
620 				TftpLastBlock = TftpBlock;
621 			}
622 		}
623 #endif
624 		TftpSend();
625 
626 #ifdef CONFIG_MCAST_TFTP
627 		if (Multicast) {
628 			if (MasterClient && (TftpBlock >= TftpEndingBlock)) {
629 				puts("\nMulticast tftp done\n");
630 				mcast_cleanup();
631 				NetState = NETLOOP_SUCCESS;
632 			}
633 		}
634 		else
635 #endif
636 		if (len < TftpBlkSize)
637 			tftp_complete();
638 		break;
639 
640 	case TFTP_ERROR:
641 		printf("\nTFTP error: '%s' (%d)\n",
642 		       pkt + 2, ntohs(*(ushort *)pkt));
643 
644 		switch (ntohs(*(ushort *)pkt)) {
645 		case TFTP_ERR_FILE_NOT_FOUND:
646 		case TFTP_ERR_ACCESS_DENIED:
647 			puts("Not retrying...\n");
648 			eth_halt();
649 			NetState = NETLOOP_FAIL;
650 			break;
651 		case TFTP_ERR_UNDEFINED:
652 		case TFTP_ERR_DISK_FULL:
653 		case TFTP_ERR_UNEXPECTED_OPCODE:
654 		case TFTP_ERR_UNKNOWN_TRANSFER_ID:
655 		case TFTP_ERR_FILE_ALREADY_EXISTS:
656 		default:
657 			puts("Starting again\n\n");
658 #ifdef CONFIG_MCAST_TFTP
659 			mcast_cleanup();
660 #endif
661 			NetStartAgain();
662 			break;
663 		}
664 		break;
665 	}
666 }
667 
668 
669 static void
670 TftpTimeout(void)
671 {
672 	if (++TftpTimeoutCount > TftpTimeoutCountMax) {
673 		restart("Retry count exceeded");
674 	} else {
675 		puts("T ");
676 		NetSetTimeout(TftpTimeoutMSecs, TftpTimeout);
677 		if (TftpState != STATE_RECV_WRQ)
678 			TftpSend();
679 	}
680 }
681 
682 
683 void TftpStart(enum proto_t protocol)
684 {
685 	char *ep;             /* Environment pointer */
686 
687 	/*
688 	 * Allow the user to choose TFTP blocksize and timeout.
689 	 * TFTP protocol has a minimal timeout of 1 second.
690 	 */
691 	ep = getenv("tftpblocksize");
692 	if (ep != NULL)
693 		TftpBlkSizeOption = simple_strtol(ep, NULL, 10);
694 
695 	ep = getenv("tftptimeout");
696 	if (ep != NULL)
697 		TftpTimeoutMSecs = simple_strtol(ep, NULL, 10);
698 
699 	if (TftpTimeoutMSecs < 1000) {
700 		printf("TFTP timeout (%ld ms) too low, "
701 			"set minimum = 1000 ms\n",
702 			TftpTimeoutMSecs);
703 		TftpTimeoutMSecs = 1000;
704 	}
705 
706 	debug("TFTP blocksize = %i, timeout = %ld ms\n",
707 		TftpBlkSizeOption, TftpTimeoutMSecs);
708 
709 	TftpRemoteIP = NetServerIP;
710 	if (BootFile[0] == '\0') {
711 		sprintf(default_filename, "%02lX%02lX%02lX%02lX.img",
712 			NetOurIP & 0xFF,
713 			(NetOurIP >>  8) & 0xFF,
714 			(NetOurIP >> 16) & 0xFF,
715 			(NetOurIP >> 24) & 0xFF);
716 
717 		strncpy(tftp_filename, default_filename, MAX_LEN);
718 		tftp_filename[MAX_LEN-1] = 0;
719 
720 		printf("*** Warning: no boot file name; using '%s'\n",
721 			tftp_filename);
722 	} else {
723 		char *p = strchr(BootFile, ':');
724 
725 		if (p == NULL) {
726 			strncpy(tftp_filename, BootFile, MAX_LEN);
727 			tftp_filename[MAX_LEN-1] = 0;
728 		} else {
729 			TftpRemoteIP = string_to_ip(BootFile);
730 			strncpy(tftp_filename, p + 1, MAX_LEN);
731 			tftp_filename[MAX_LEN-1] = 0;
732 		}
733 	}
734 
735 	printf("Using %s device\n", eth_get_name());
736 	printf("TFTP %s server %pI4; our IP address is %pI4",
737 #ifdef CONFIG_CMD_TFTPPUT
738 	       protocol == TFTPPUT ? "to" : "from",
739 #else
740 		"from",
741 #endif
742 		&TftpRemoteIP, &NetOurIP);
743 
744 	/* Check if we need to send across this subnet */
745 	if (NetOurGatewayIP && NetOurSubnetMask) {
746 		IPaddr_t OurNet	= NetOurIP    & NetOurSubnetMask;
747 		IPaddr_t RemoteNet	= TftpRemoteIP & NetOurSubnetMask;
748 
749 		if (OurNet != RemoteNet)
750 			printf("; sending through gateway %pI4",
751 			       &NetOurGatewayIP);
752 	}
753 	putc('\n');
754 
755 	printf("Filename '%s'.", tftp_filename);
756 
757 	if (NetBootFileSize) {
758 		printf(" Size is 0x%x Bytes = ", NetBootFileSize<<9);
759 		print_size(NetBootFileSize<<9, "");
760 	}
761 
762 	putc('\n');
763 #ifdef CONFIG_CMD_TFTPPUT
764 	TftpWriting = (protocol == TFTPPUT);
765 	if (TftpWriting) {
766 		printf("Save address: 0x%lx\n", save_addr);
767 		printf("Save size:    0x%lx\n", save_size);
768 		NetBootFileXferSize = save_size;
769 		puts("Saving: *\b");
770 		TftpState = STATE_SEND_WRQ;
771 		new_transfer();
772 	} else
773 #endif
774 	{
775 		printf("Load address: 0x%lx\n", load_addr);
776 		puts("Loading: *\b");
777 		TftpState = STATE_SEND_RRQ;
778 	}
779 
780 	TftpTimeoutCountMax = TftpRRQTimeoutCountMax;
781 
782 	NetSetTimeout(TftpTimeoutMSecs, TftpTimeout);
783 	NetSetHandler(TftpHandler);
784 #ifdef CONFIG_CMD_TFTPPUT
785 	net_set_icmp_handler(icmp_handler);
786 #endif
787 	TftpRemotePort = WELL_KNOWN_PORT;
788 	TftpTimeoutCount = 0;
789 	/* Use a pseudo-random port unless a specific port is set */
790 	TftpOurPort = 1024 + (get_timer(0) % 3072);
791 
792 #ifdef CONFIG_TFTP_PORT
793 	ep = getenv("tftpdstp");
794 	if (ep != NULL)
795 		TftpRemotePort = simple_strtol(ep, NULL, 10);
796 	ep = getenv("tftpsrcp");
797 	if (ep != NULL)
798 		TftpOurPort = simple_strtol(ep, NULL, 10);
799 #endif
800 	TftpBlock = 0;
801 
802 	/* zero out server ether in case the server ip has changed */
803 	memset(NetServerEther, 0, 6);
804 	/* Revert TftpBlkSize to dflt */
805 	TftpBlkSize = TFTP_BLOCK_SIZE;
806 #ifdef CONFIG_MCAST_TFTP
807 	mcast_cleanup();
808 #endif
809 #ifdef CONFIG_TFTP_TSIZE
810 	TftpTsize = 0;
811 	TftpNumchars = 0;
812 #endif
813 
814 	TftpSend();
815 }
816 
817 #ifdef CONFIG_CMD_TFTPSRV
818 void
819 TftpStartServer(void)
820 {
821 	tftp_filename[0] = 0;
822 
823 	printf("Using %s device\n", eth_get_name());
824 	printf("Listening for TFTP transfer on %pI4\n", &NetOurIP);
825 	printf("Load address: 0x%lx\n", load_addr);
826 
827 	puts("Loading: *\b");
828 
829 	TftpTimeoutCountMax = TIMEOUT_COUNT;
830 	TftpTimeoutCount = 0;
831 	TftpTimeoutMSecs = TIMEOUT;
832 	NetSetTimeout(TftpTimeoutMSecs, TftpTimeout);
833 
834 	/* Revert TftpBlkSize to dflt */
835 	TftpBlkSize = TFTP_BLOCK_SIZE;
836 	TftpBlock = 0;
837 	TftpOurPort = WELL_KNOWN_PORT;
838 
839 #ifdef CONFIG_TFTP_TSIZE
840 	TftpTsize = 0;
841 	TftpNumchars = 0;
842 #endif
843 
844 	TftpState = STATE_RECV_WRQ;
845 	NetSetHandler(TftpHandler);
846 }
847 #endif /* CONFIG_CMD_TFTPSRV */
848 
849 #ifdef CONFIG_MCAST_TFTP
850 /* Credits: atftp project.
851  */
852 
853 /* pick up BcastAddr, Port, and whether I am [now] the master-client. *
854  * Frame:
855  *    +-------+-----------+---+-------~~-------+---+
856  *    |  opc  | multicast | 0 | addr, port, mc | 0 |
857  *    +-------+-----------+---+-------~~-------+---+
858  * The multicast addr/port becomes what I listen to, and if 'mc' is '1' then
859  * I am the new master-client so must send ACKs to DataBlocks.  If I am not
860  * master-client, I'm a passive client, gathering what DataBlocks I may and
861  * making note of which ones I got in my bitmask.
862  * In theory, I never go from master->passive..
863  * .. this comes in with pkt already pointing just past opc
864  */
865 static void parse_multicast_oack(char *pkt, int len)
866 {
867 	int i;
868 	IPaddr_t addr;
869 	char *mc_adr, *port,  *mc;
870 
871 	mc_adr = port = mc = NULL;
872 	/* march along looking for 'multicast\0', which has to start at least
873 	 * 14 bytes back from the end.
874 	 */
875 	for (i = 0; i < len-14; i++)
876 		if (strcmp(pkt+i, "multicast") == 0)
877 			break;
878 	if (i >= (len-14)) /* non-Multicast OACK, ign. */
879 		return;
880 
881 	i += 10; /* strlen multicast */
882 	mc_adr = pkt+i;
883 	for (; i < len; i++) {
884 		if (*(pkt+i) == ',') {
885 			*(pkt+i) = '\0';
886 			if (port) {
887 				mc = pkt+i+1;
888 				break;
889 			} else {
890 				port = pkt+i+1;
891 			}
892 		}
893 	}
894 	if (!port || !mc_adr || !mc)
895 		return;
896 	if (Multicast && MasterClient) {
897 		printf("I got a OACK as master Client, WRONG!\n");
898 		return;
899 	}
900 	/* ..I now accept packets destined for this MCAST addr, port */
901 	if (!Multicast) {
902 		if (Bitmap) {
903 			printf("Internal failure! no mcast.\n");
904 			free(Bitmap);
905 			Bitmap = NULL;
906 			ProhibitMcast = 1;
907 			return ;
908 		}
909 		/* I malloc instead of pre-declare; so that if the file ends
910 		 * up being too big for this bitmap I can retry
911 		 */
912 		Bitmap = malloc(Mapsize);
913 		if (!Bitmap) {
914 			printf("No Bitmap, no multicast. Sorry.\n");
915 			ProhibitMcast = 1;
916 			return;
917 		}
918 		memset(Bitmap, 0, Mapsize);
919 		PrevBitmapHole = 0;
920 		Multicast = 1;
921 	}
922 	addr = string_to_ip(mc_adr);
923 	if (Mcast_addr != addr) {
924 		if (Mcast_addr)
925 			eth_mcast_join(Mcast_addr, 0);
926 		Mcast_addr = addr;
927 		if (eth_mcast_join(Mcast_addr, 1)) {
928 			printf("Fail to set mcast, revert to TFTP\n");
929 			ProhibitMcast = 1;
930 			mcast_cleanup();
931 			NetStartAgain();
932 		}
933 	}
934 	MasterClient = (unsigned char)simple_strtoul((char *)mc, NULL, 10);
935 	Mcast_port = (unsigned short)simple_strtoul(port, NULL, 10);
936 	printf("Multicast: %s:%d [%d]\n", mc_adr, Mcast_port, MasterClient);
937 	return;
938 }
939 
940 #endif /* Multicast TFTP */
941