xref: /openbmc/u-boot/net/tftp.c (revision 98a48c5d) 
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 
85 #define STATE_SEND_RRQ	1
86 #define STATE_DATA	2
87 #define STATE_TOO_LARGE	3
88 #define STATE_BAD_MAGIC	4
89 #define STATE_OACK	5
90 #define STATE_RECV_WRQ	6
91 
92 /* default TFTP block size */
93 #define TFTP_BLOCK_SIZE		512
94 /* sequence number is 16 bit */
95 #define TFTP_SEQUENCE_SIZE	((ulong)(1<<16))
96 
97 #define DEFAULT_NAME_LEN	(8 + 4 + 1)
98 static char default_filename[DEFAULT_NAME_LEN];
99 
100 #ifndef CONFIG_TFTP_FILE_NAME_MAX_LEN
101 #define MAX_LEN 128
102 #else
103 #define MAX_LEN CONFIG_TFTP_FILE_NAME_MAX_LEN
104 #endif
105 
106 static char tftp_filename[MAX_LEN];
107 
108 #ifdef CONFIG_SYS_DIRECT_FLASH_TFTP
109 extern flash_info_t flash_info[];
110 #endif
111 
112 /* 512 is poor choice for ethernet, MTU is typically 1500.
113  * Minus eth.hdrs thats 1468.  Can get 2x better throughput with
114  * almost-MTU block sizes.  At least try... fall back to 512 if need be.
115  * (but those using CONFIG_IP_DEFRAG may want to set a larger block in cfg file)
116  */
117 #ifdef CONFIG_TFTP_BLOCKSIZE
118 #define TFTP_MTU_BLOCKSIZE CONFIG_TFTP_BLOCKSIZE
119 #else
120 #define TFTP_MTU_BLOCKSIZE 1468
121 #endif
122 
123 static unsigned short TftpBlkSize = TFTP_BLOCK_SIZE;
124 static unsigned short TftpBlkSizeOption = TFTP_MTU_BLOCKSIZE;
125 
126 #ifdef CONFIG_MCAST_TFTP
127 #include <malloc.h>
128 #define MTFTP_BITMAPSIZE	0x1000
129 static unsigned *Bitmap;
130 static int PrevBitmapHole, Mapsize = MTFTP_BITMAPSIZE;
131 static uchar ProhibitMcast, MasterClient;
132 static uchar Multicast;
133 extern IPaddr_t Mcast_addr;
134 static int Mcast_port;
135 static ulong TftpEndingBlock; /* can get 'last' block before done..*/
136 
137 static void parse_multicast_oack(char *pkt, int len);
138 
139 static void
140 mcast_cleanup(void)
141 {
142 	if (Mcast_addr)
143 		eth_mcast_join(Mcast_addr, 0);
144 	if (Bitmap)
145 		free(Bitmap);
146 	Bitmap = NULL;
147 	Mcast_addr = Multicast = Mcast_port = 0;
148 	TftpEndingBlock = -1;
149 }
150 
151 #endif	/* CONFIG_MCAST_TFTP */
152 
153 static __inline__ void
154 store_block(unsigned block, uchar *src, unsigned len)
155 {
156 	ulong offset = block * TftpBlkSize + TftpBlockWrapOffset;
157 	ulong newsize = offset + len;
158 #ifdef CONFIG_SYS_DIRECT_FLASH_TFTP
159 	int i, rc = 0;
160 
161 	for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; i++) {
162 		/* start address in flash? */
163 		if (flash_info[i].flash_id == FLASH_UNKNOWN)
164 			continue;
165 		if (load_addr + offset >= flash_info[i].start[0]) {
166 			rc = 1;
167 			break;
168 		}
169 	}
170 
171 	if (rc) { /* Flash is destination for this packet */
172 		rc = flash_write((char *)src, (ulong)(load_addr+offset), len);
173 		if (rc) {
174 			flash_perror(rc);
175 			NetState = NETLOOP_FAIL;
176 			return;
177 		}
178 	}
179 	else
180 #endif /* CONFIG_SYS_DIRECT_FLASH_TFTP */
181 	{
182 		(void)memcpy((void *)(load_addr + offset), src, len);
183 	}
184 #ifdef CONFIG_MCAST_TFTP
185 	if (Multicast)
186 		ext2_set_bit(block, Bitmap);
187 #endif
188 
189 	if (NetBootFileXferSize < newsize)
190 		NetBootFileXferSize = newsize;
191 }
192 
193 static void TftpSend(void);
194 static void TftpTimeout(void);
195 
196 /**********************************************************************/
197 
198 static void
199 TftpSend(void)
200 {
201 	volatile uchar *pkt;
202 	volatile uchar *xp;
203 	int		len = 0;
204 	volatile ushort *s;
205 
206 #ifdef CONFIG_MCAST_TFTP
207 	/* Multicast TFTP.. non-MasterClients do not ACK data. */
208 	if (Multicast
209 	 && (TftpState == STATE_DATA)
210 	 && (MasterClient == 0))
211 		return;
212 #endif
213 	/*
214 	 *	We will always be sending some sort of packet, so
215 	 *	cobble together the packet headers now.
216 	 */
217 	pkt = NetTxPacket + NetEthHdrSize() + IP_HDR_SIZE;
218 
219 	switch (TftpState) {
220 
221 	case STATE_SEND_RRQ:
222 		xp = pkt;
223 		s = (ushort *)pkt;
224 		*s++ = htons(TFTP_RRQ);
225 		pkt = (uchar *)s;
226 		strcpy((char *)pkt, tftp_filename);
227 		pkt += strlen(tftp_filename) + 1;
228 		strcpy((char *)pkt, "octet");
229 		pkt += 5 /*strlen("octet")*/ + 1;
230 		strcpy((char *)pkt, "timeout");
231 		pkt += 7 /*strlen("timeout")*/ + 1;
232 		sprintf((char *)pkt, "%lu", TftpTimeoutMSecs / 1000);
233 		debug("send option \"timeout %s\"\n", (char *)pkt);
234 		pkt += strlen((char *)pkt) + 1;
235 #ifdef CONFIG_TFTP_TSIZE
236 		memcpy((char *)pkt, "tsize\0000\0", 8);
237 		pkt += 8;
238 #endif
239 		/* try for more effic. blk size */
240 		pkt += sprintf((char *)pkt, "blksize%c%d%c",
241 				0, TftpBlkSizeOption, 0);
242 #ifdef CONFIG_MCAST_TFTP
243 		/* Check all preconditions before even trying the option */
244 		if (!ProhibitMcast
245 		 && (Bitmap = malloc(Mapsize))
246 		 && eth_get_dev()->mcast) {
247 			free(Bitmap);
248 			Bitmap = NULL;
249 			pkt += sprintf((char *)pkt, "multicast%c%c", 0, 0);
250 		}
251 #endif /* CONFIG_MCAST_TFTP */
252 		len = pkt - xp;
253 		break;
254 
255 	case STATE_OACK:
256 #ifdef CONFIG_MCAST_TFTP
257 		/* My turn!  Start at where I need blocks I missed.*/
258 		if (Multicast)
259 			TftpBlock = ext2_find_next_zero_bit(Bitmap,
260 							    (Mapsize*8), 0);
261 		/*..falling..*/
262 #endif
263 
264 	case STATE_RECV_WRQ:
265 	case STATE_DATA:
266 		xp = pkt;
267 		s = (ushort *)pkt;
268 		*s++ = htons(TFTP_ACK);
269 		*s++ = htons(TftpBlock);
270 		pkt = (uchar *)s;
271 		len = pkt - xp;
272 		break;
273 
274 	case STATE_TOO_LARGE:
275 		xp = pkt;
276 		s = (ushort *)pkt;
277 		*s++ = htons(TFTP_ERROR);
278 		*s++ = htons(3);
279 		pkt = (uchar *)s;
280 		strcpy((char *)pkt, "File too large");
281 		pkt += 14 /*strlen("File too large")*/ + 1;
282 		len = pkt - xp;
283 		break;
284 
285 	case STATE_BAD_MAGIC:
286 		xp = pkt;
287 		s = (ushort *)pkt;
288 		*s++ = htons(TFTP_ERROR);
289 		*s++ = htons(2);
290 		pkt = (uchar *)s;
291 		strcpy((char *)pkt, "File has bad magic");
292 		pkt += 18 /*strlen("File has bad magic")*/ + 1;
293 		len = pkt - xp;
294 		break;
295 	}
296 
297 	NetSendUDPPacket(NetServerEther, TftpRemoteIP, TftpRemotePort,
298 			 TftpOurPort, len);
299 }
300 
301 
302 static void
303 TftpHandler(uchar *pkt, unsigned dest, IPaddr_t sip, unsigned src,
304 	    unsigned len)
305 {
306 	ushort proto;
307 	ushort *s;
308 	int i;
309 
310 	if (dest != TftpOurPort) {
311 #ifdef CONFIG_MCAST_TFTP
312 		if (Multicast
313 		 && (!Mcast_port || (dest != Mcast_port)))
314 #endif
315 			return;
316 	}
317 	if (TftpState != STATE_SEND_RRQ && src != TftpRemotePort &&
318 	    TftpState != STATE_RECV_WRQ)
319 		return;
320 
321 	if (len < 2)
322 		return;
323 	len -= 2;
324 	/* warning: don't use increment (++) in ntohs() macros!! */
325 	s = (ushort *)pkt;
326 	proto = *s++;
327 	pkt = (uchar *)s;
328 	switch (ntohs(proto)) {
329 
330 	case TFTP_RRQ:
331 	case TFTP_ACK:
332 		break;
333 	default:
334 		break;
335 
336 #ifdef CONFIG_CMD_TFTPSRV
337 	case TFTP_WRQ:
338 		debug("Got WRQ\n");
339 		TftpRemoteIP = sip;
340 		TftpRemotePort = src;
341 		TftpOurPort = 1024 + (get_timer(0) % 3072);
342 		TftpLastBlock = 0;
343 		TftpBlockWrap = 0;
344 		TftpBlockWrapOffset = 0;
345 		TftpSend(); /* Send ACK(0) */
346 		break;
347 #endif
348 
349 	case TFTP_OACK:
350 		debug("Got OACK: %s %s\n",
351 			pkt,
352 			pkt + strlen((char *)pkt) + 1);
353 		TftpState = STATE_OACK;
354 		TftpRemotePort = src;
355 		/*
356 		 * Check for 'blksize' option.
357 		 * Careful: "i" is signed, "len" is unsigned, thus
358 		 * something like "len-8" may give a *huge* number
359 		 */
360 		for (i = 0; i+8 < len; i++) {
361 			if (strcmp((char *)pkt+i, "blksize") == 0) {
362 				TftpBlkSize = (unsigned short)
363 					simple_strtoul((char *)pkt+i+8, NULL,
364 						       10);
365 				debug("Blocksize ack: %s, %d\n",
366 					(char *)pkt+i+8, TftpBlkSize);
367 			}
368 #ifdef CONFIG_TFTP_TSIZE
369 			if (strcmp((char *)pkt+i, "tsize") == 0) {
370 				TftpTsize = simple_strtoul((char *)pkt+i+6,
371 							   NULL, 10);
372 				debug("size = %s, %d\n",
373 					 (char *)pkt+i+6, TftpTsize);
374 			}
375 #endif
376 		}
377 #ifdef CONFIG_MCAST_TFTP
378 		parse_multicast_oack((char *)pkt, len-1);
379 		if ((Multicast) && (!MasterClient))
380 			TftpState = STATE_DATA;	/* passive.. */
381 		else
382 #endif
383 		TftpSend(); /* Send ACK */
384 		break;
385 	case TFTP_DATA:
386 		if (len < 2)
387 			return;
388 		len -= 2;
389 		TftpBlock = ntohs(*(ushort *)pkt);
390 
391 		/*
392 		 * RFC1350 specifies that the first data packet will
393 		 * have sequence number 1. If we receive a sequence
394 		 * number of 0 this means that there was a wrap
395 		 * around of the (16 bit) counter.
396 		 */
397 		if (TftpBlock == 0) {
398 			TftpBlockWrap++;
399 			TftpBlockWrapOffset +=
400 				TftpBlkSize * TFTP_SEQUENCE_SIZE;
401 			printf("\n\t %lu MB received\n\t ",
402 				TftpBlockWrapOffset>>20);
403 		}
404 #ifdef CONFIG_TFTP_TSIZE
405 		else if (TftpTsize) {
406 			while (TftpNumchars <
407 			       NetBootFileXferSize * 50 / TftpTsize) {
408 				putc('#');
409 				TftpNumchars++;
410 			}
411 		}
412 #endif
413 		else {
414 			if (((TftpBlock - 1) % 10) == 0)
415 				putc('#');
416 			else if ((TftpBlock % (10 * HASHES_PER_LINE)) == 0)
417 				puts("\n\t ");
418 		}
419 
420 		if (TftpState == STATE_SEND_RRQ)
421 			debug("Server did not acknowledge timeout option!\n");
422 
423 		if (TftpState == STATE_SEND_RRQ || TftpState == STATE_OACK ||
424 		    TftpState == STATE_RECV_WRQ) {
425 			/* first block received */
426 			TftpState = STATE_DATA;
427 			TftpRemotePort = src;
428 			TftpLastBlock = 0;
429 			TftpBlockWrap = 0;
430 			TftpBlockWrapOffset = 0;
431 
432 #ifdef CONFIG_MCAST_TFTP
433 			if (Multicast) { /* start!=1 common if mcast */
434 				TftpLastBlock = TftpBlock - 1;
435 			} else
436 #endif
437 			if (TftpBlock != 1) {	/* Assertion */
438 				printf("\nTFTP error: "
439 				       "First block is not block 1 (%ld)\n"
440 				       "Starting again\n\n",
441 					TftpBlock);
442 				NetStartAgain();
443 				break;
444 			}
445 		}
446 
447 		if (TftpBlock == TftpLastBlock) {
448 			/*
449 			 *	Same block again; ignore it.
450 			 */
451 			break;
452 		}
453 
454 		TftpLastBlock = TftpBlock;
455 		TftpTimeoutCountMax = TIMEOUT_COUNT;
456 		NetSetTimeout(TftpTimeoutMSecs, TftpTimeout);
457 
458 		store_block(TftpBlock - 1, pkt + 2, len);
459 
460 		/*
461 		 *	Acknowledge the block just received, which will prompt
462 		 *	the remote for the next one.
463 		 */
464 #ifdef CONFIG_MCAST_TFTP
465 		/* if I am the MasterClient, actively calculate what my next
466 		 * needed block is; else I'm passive; not ACKING
467 		 */
468 		if (Multicast) {
469 			if (len < TftpBlkSize)  {
470 				TftpEndingBlock = TftpBlock;
471 			} else if (MasterClient) {
472 				TftpBlock = PrevBitmapHole =
473 					ext2_find_next_zero_bit(
474 						Bitmap,
475 						(Mapsize*8),
476 						PrevBitmapHole);
477 				if (TftpBlock > ((Mapsize*8) - 1)) {
478 					printf("tftpfile too big\n");
479 					/* try to double it and retry */
480 					Mapsize <<= 1;
481 					mcast_cleanup();
482 					NetStartAgain();
483 					return;
484 				}
485 				TftpLastBlock = TftpBlock;
486 			}
487 		}
488 #endif
489 		TftpSend();
490 
491 #ifdef CONFIG_MCAST_TFTP
492 		if (Multicast) {
493 			if (MasterClient && (TftpBlock >= TftpEndingBlock)) {
494 				puts("\nMulticast tftp done\n");
495 				mcast_cleanup();
496 				NetState = NETLOOP_SUCCESS;
497 			}
498 		}
499 		else
500 #endif
501 		if (len < TftpBlkSize) {
502 			/*
503 			 *	We received the whole thing.  Try to
504 			 *	run it.
505 			 */
506 #ifdef CONFIG_TFTP_TSIZE
507 			/* Print hash marks for the last packet received */
508 			while (TftpTsize && TftpNumchars < 49) {
509 				putc('#');
510 				TftpNumchars++;
511 			}
512 #endif
513 			puts("\ndone\n");
514 			NetState = NETLOOP_SUCCESS;
515 		}
516 		break;
517 
518 	case TFTP_ERROR:
519 		printf("\nTFTP error: '%s' (%d)\n",
520 		       pkt + 2, ntohs(*(ushort *)pkt));
521 
522 		switch (ntohs(*(ushort *)pkt)) {
523 		case TFTP_ERR_FILE_NOT_FOUND:
524 		case TFTP_ERR_ACCESS_DENIED:
525 			puts("Not retrying...\n");
526 			eth_halt();
527 			NetState = NETLOOP_FAIL;
528 			break;
529 		case TFTP_ERR_UNDEFINED:
530 		case TFTP_ERR_DISK_FULL:
531 		case TFTP_ERR_UNEXPECTED_OPCODE:
532 		case TFTP_ERR_UNKNOWN_TRANSFER_ID:
533 		case TFTP_ERR_FILE_ALREADY_EXISTS:
534 		default:
535 			puts("Starting again\n\n");
536 #ifdef CONFIG_MCAST_TFTP
537 			mcast_cleanup();
538 #endif
539 			NetStartAgain();
540 			break;
541 		}
542 		break;
543 	}
544 }
545 
546 
547 static void
548 TftpTimeout(void)
549 {
550 	if (++TftpTimeoutCount > TftpTimeoutCountMax) {
551 		puts("\nRetry count exceeded; starting again\n");
552 #ifdef CONFIG_MCAST_TFTP
553 		mcast_cleanup();
554 #endif
555 		NetStartAgain();
556 	} else {
557 		puts("T ");
558 		NetSetTimeout(TftpTimeoutMSecs, TftpTimeout);
559 		if (TftpState != STATE_RECV_WRQ)
560 			TftpSend();
561 	}
562 }
563 
564 
565 void
566 TftpStart(void)
567 {
568 	char *ep;             /* Environment pointer */
569 
570 	/*
571 	 * Allow the user to choose TFTP blocksize and timeout.
572 	 * TFTP protocol has a minimal timeout of 1 second.
573 	 */
574 	ep = getenv("tftpblocksize");
575 	if (ep != NULL)
576 		TftpBlkSizeOption = simple_strtol(ep, NULL, 10);
577 
578 	ep = getenv("tftptimeout");
579 	if (ep != NULL)
580 		TftpTimeoutMSecs = simple_strtol(ep, NULL, 10);
581 
582 	if (TftpTimeoutMSecs < 1000) {
583 		printf("TFTP timeout (%ld ms) too low, "
584 			"set minimum = 1000 ms\n",
585 			TftpTimeoutMSecs);
586 		TftpTimeoutMSecs = 1000;
587 	}
588 
589 	debug("TFTP blocksize = %i, timeout = %ld ms\n",
590 		TftpBlkSizeOption, TftpTimeoutMSecs);
591 
592 	TftpRemoteIP = NetServerIP;
593 	if (BootFile[0] == '\0') {
594 		sprintf(default_filename, "%02lX%02lX%02lX%02lX.img",
595 			NetOurIP & 0xFF,
596 			(NetOurIP >>  8) & 0xFF,
597 			(NetOurIP >> 16) & 0xFF,
598 			(NetOurIP >> 24) & 0xFF);
599 
600 		strncpy(tftp_filename, default_filename, MAX_LEN);
601 		tftp_filename[MAX_LEN-1] = 0;
602 
603 		printf("*** Warning: no boot file name; using '%s'\n",
604 			tftp_filename);
605 	} else {
606 		char *p = strchr(BootFile, ':');
607 
608 		if (p == NULL) {
609 			strncpy(tftp_filename, BootFile, MAX_LEN);
610 			tftp_filename[MAX_LEN-1] = 0;
611 		} else {
612 			TftpRemoteIP = string_to_ip(BootFile);
613 			strncpy(tftp_filename, p + 1, MAX_LEN);
614 			tftp_filename[MAX_LEN-1] = 0;
615 		}
616 	}
617 
618 #if defined(CONFIG_NET_MULTI)
619 	printf("Using %s device\n", eth_get_name());
620 #endif
621 	printf("TFTP from server %pI4"
622 		"; our IP address is %pI4", &TftpRemoteIP, &NetOurIP);
623 
624 	/* Check if we need to send across this subnet */
625 	if (NetOurGatewayIP && NetOurSubnetMask) {
626 		IPaddr_t OurNet	= NetOurIP    & NetOurSubnetMask;
627 		IPaddr_t RemoteNet	= TftpRemoteIP & NetOurSubnetMask;
628 
629 		if (OurNet != RemoteNet)
630 			printf("; sending through gateway %pI4",
631 			       &NetOurGatewayIP);
632 	}
633 	putc('\n');
634 
635 	printf("Filename '%s'.", tftp_filename);
636 
637 	if (NetBootFileSize) {
638 		printf(" Size is 0x%x Bytes = ", NetBootFileSize<<9);
639 		print_size(NetBootFileSize<<9, "");
640 	}
641 
642 	putc('\n');
643 
644 	printf("Load address: 0x%lx\n", load_addr);
645 
646 	puts("Loading: *\b");
647 
648 	TftpTimeoutCountMax = TftpRRQTimeoutCountMax;
649 
650 	NetSetTimeout(TftpTimeoutMSecs, TftpTimeout);
651 	NetSetHandler(TftpHandler);
652 
653 	TftpRemotePort = WELL_KNOWN_PORT;
654 	TftpTimeoutCount = 0;
655 	TftpState = STATE_SEND_RRQ;
656 	/* Use a pseudo-random port unless a specific port is set */
657 	TftpOurPort = 1024 + (get_timer(0) % 3072);
658 
659 #ifdef CONFIG_TFTP_PORT
660 	ep = getenv("tftpdstp");
661 	if (ep != NULL)
662 		TftpRemotePort = simple_strtol(ep, NULL, 10);
663 	ep = getenv("tftpsrcp");
664 	if (ep != NULL)
665 		TftpOurPort = simple_strtol(ep, NULL, 10);
666 #endif
667 	TftpBlock = 0;
668 
669 	/* zero out server ether in case the server ip has changed */
670 	memset(NetServerEther, 0, 6);
671 	/* Revert TftpBlkSize to dflt */
672 	TftpBlkSize = TFTP_BLOCK_SIZE;
673 #ifdef CONFIG_MCAST_TFTP
674 	mcast_cleanup();
675 #endif
676 #ifdef CONFIG_TFTP_TSIZE
677 	TftpTsize = 0;
678 	TftpNumchars = 0;
679 #endif
680 
681 	TftpSend();
682 }
683 
684 #ifdef CONFIG_CMD_TFTPSRV
685 void
686 TftpStartServer(void)
687 {
688 	tftp_filename[0] = 0;
689 
690 #if defined(CONFIG_NET_MULTI)
691 	printf("Using %s device\n", eth_get_name());
692 #endif
693 	printf("Listening for TFTP transfer on %pI4\n", &NetOurIP);
694 	printf("Load address: 0x%lx\n", load_addr);
695 
696 	puts("Loading: *\b");
697 
698 	TftpTimeoutCountMax = TIMEOUT_COUNT;
699 	TftpTimeoutCount = 0;
700 	TftpTimeoutMSecs = TIMEOUT;
701 	NetSetTimeout(TftpTimeoutMSecs, TftpTimeout);
702 
703 	/* Revert TftpBlkSize to dflt */
704 	TftpBlkSize = TFTP_BLOCK_SIZE;
705 	TftpBlock = 0;
706 	TftpOurPort = WELL_KNOWN_PORT;
707 
708 #ifdef CONFIG_TFTP_TSIZE
709 	TftpTsize = 0;
710 	TftpNumchars = 0;
711 #endif
712 
713 	TftpState = STATE_RECV_WRQ;
714 	NetSetHandler(TftpHandler);
715 }
716 #endif /* CONFIG_CMD_TFTPSRV */
717 
718 #ifdef CONFIG_MCAST_TFTP
719 /* Credits: atftp project.
720  */
721 
722 /* pick up BcastAddr, Port, and whether I am [now] the master-client. *
723  * Frame:
724  *    +-------+-----------+---+-------~~-------+---+
725  *    |  opc  | multicast | 0 | addr, port, mc | 0 |
726  *    +-------+-----------+---+-------~~-------+---+
727  * The multicast addr/port becomes what I listen to, and if 'mc' is '1' then
728  * I am the new master-client so must send ACKs to DataBlocks.  If I am not
729  * master-client, I'm a passive client, gathering what DataBlocks I may and
730  * making note of which ones I got in my bitmask.
731  * In theory, I never go from master->passive..
732  * .. this comes in with pkt already pointing just past opc
733  */
734 static void parse_multicast_oack(char *pkt, int len)
735 {
736 	int i;
737 	IPaddr_t addr;
738 	char *mc_adr, *port,  *mc;
739 
740 	mc_adr = port = mc = NULL;
741 	/* march along looking for 'multicast\0', which has to start at least
742 	 * 14 bytes back from the end.
743 	 */
744 	for (i = 0; i < len-14; i++)
745 		if (strcmp(pkt+i, "multicast") == 0)
746 			break;
747 	if (i >= (len-14)) /* non-Multicast OACK, ign. */
748 		return;
749 
750 	i += 10; /* strlen multicast */
751 	mc_adr = pkt+i;
752 	for (; i < len; i++) {
753 		if (*(pkt+i) == ',') {
754 			*(pkt+i) = '\0';
755 			if (port) {
756 				mc = pkt+i+1;
757 				break;
758 			} else {
759 				port = pkt+i+1;
760 			}
761 		}
762 	}
763 	if (!port || !mc_adr || !mc)
764 		return;
765 	if (Multicast && MasterClient) {
766 		printf("I got a OACK as master Client, WRONG!\n");
767 		return;
768 	}
769 	/* ..I now accept packets destined for this MCAST addr, port */
770 	if (!Multicast) {
771 		if (Bitmap) {
772 			printf("Internal failure! no mcast.\n");
773 			free(Bitmap);
774 			Bitmap = NULL;
775 			ProhibitMcast = 1;
776 			return ;
777 		}
778 		/* I malloc instead of pre-declare; so that if the file ends
779 		 * up being too big for this bitmap I can retry
780 		 */
781 		Bitmap = malloc(Mapsize);
782 		if (!Bitmap) {
783 			printf("No Bitmap, no multicast. Sorry.\n");
784 			ProhibitMcast = 1;
785 			return;
786 		}
787 		memset(Bitmap, 0, Mapsize);
788 		PrevBitmapHole = 0;
789 		Multicast = 1;
790 	}
791 	addr = string_to_ip(mc_adr);
792 	if (Mcast_addr != addr) {
793 		if (Mcast_addr)
794 			eth_mcast_join(Mcast_addr, 0);
795 		Mcast_addr = addr;
796 		if (eth_mcast_join(Mcast_addr, 1)) {
797 			printf("Fail to set mcast, revert to TFTP\n");
798 			ProhibitMcast = 1;
799 			mcast_cleanup();
800 			NetStartAgain();
801 		}
802 	}
803 	MasterClient = (unsigned char)simple_strtoul((char *)mc, NULL, 10);
804 	Mcast_port = (unsigned short)simple_strtoul(port, NULL, 10);
805 	printf("Multicast: %s:%d [%d]\n", mc_adr, Mcast_port, MasterClient);
806 	return;
807 }
808 
809 #endif /* Multicast TFTP */
810