xref: /openbmc/u-boot/net/tftp.c (revision a380279b)
1 /*
2  *	Copyright 1994, 1995, 2000 Neil Russell.
3  *	(See License)
4  *	Copyright 2000, 2001 DENX Software Engineering, Wolfgang Denk, wd@denx.de
5  */
6 
7 #include <common.h>
8 #include <command.h>
9 #include <net.h>
10 #include "tftp.h"
11 #include "bootp.h"
12 
13 #if defined(CONFIG_CMD_NET)
14 
15 #define WELL_KNOWN_PORT	69		/* Well known TFTP port #		*/
16 #define TIMEOUT		5000UL		/* Millisecs to timeout for lost pkt */
17 #ifndef	CONFIG_NET_RETRY_COUNT
18 # define TIMEOUT_COUNT	10		/* # of timeouts before giving up  */
19 #else
20 # define TIMEOUT_COUNT  (CONFIG_NET_RETRY_COUNT * 2)
21 #endif
22 					/* (for checking the image size)	*/
23 #define HASHES_PER_LINE	65		/* Number of "loading" hashes per line	*/
24 
25 /*
26  *	TFTP operations.
27  */
28 #define TFTP_RRQ	1
29 #define TFTP_WRQ	2
30 #define TFTP_DATA	3
31 #define TFTP_ACK	4
32 #define TFTP_ERROR	5
33 #define TFTP_OACK	6
34 
35 static ulong TftpTimeoutMSecs = TIMEOUT;
36 static int TftpTimeoutCountMax = TIMEOUT_COUNT;
37 
38 /*
39  * These globals govern the timeout behavior when attempting a connection to a
40  * TFTP server. TftpRRQTimeoutMSecs specifies the number of milliseconds to
41  * wait for the server to respond to initial connection. Second global,
42  * TftpRRQTimeoutCountMax, gives the number of such connection retries.
43  * TftpRRQTimeoutCountMax must be non-negative and TftpRRQTimeoutMSecs must be
44  * positive. The globals are meant to be set (and restored) by code needing
45  * non-standard timeout behavior when initiating a TFTP transfer.
46  */
47 ulong TftpRRQTimeoutMSecs = TIMEOUT;
48 int TftpRRQTimeoutCountMax = TIMEOUT_COUNT;
49 
50 static IPaddr_t TftpServerIP;
51 static int	TftpServerPort;		/* The UDP port at their end		*/
52 static int	TftpOurPort;		/* The UDP port at our end		*/
53 static int	TftpTimeoutCount;
54 static ulong	TftpBlock;		/* packet sequence number		*/
55 static ulong	TftpLastBlock;		/* last packet sequence number received */
56 static ulong	TftpBlockWrap;		/* count of sequence number wraparounds */
57 static ulong	TftpBlockWrapOffset;	/* memory offset due to wrapping	*/
58 static int	TftpState;
59 #ifdef CONFIG_TFTP_TSIZE
60 static int	TftpTsize;		/* The file size reported by the server */
61 static short	TftpNumchars;		/* The number of hashes we printed      */
62 #endif
63 
64 #define STATE_RRQ	1
65 #define STATE_DATA	2
66 #define STATE_TOO_LARGE	3
67 #define STATE_BAD_MAGIC	4
68 #define STATE_OACK	5
69 
70 #define TFTP_BLOCK_SIZE		512		    /* default TFTP block size	*/
71 #define TFTP_SEQUENCE_SIZE	((ulong)(1<<16))    /* sequence number is 16 bit */
72 
73 #define DEFAULT_NAME_LEN	(8 + 4 + 1)
74 static char default_filename[DEFAULT_NAME_LEN];
75 
76 #ifndef CONFIG_TFTP_FILE_NAME_MAX_LEN
77 #define MAX_LEN 128
78 #else
79 #define MAX_LEN CONFIG_TFTP_FILE_NAME_MAX_LEN
80 #endif
81 
82 static char tftp_filename[MAX_LEN];
83 
84 #ifdef CONFIG_SYS_DIRECT_FLASH_TFTP
85 extern flash_info_t flash_info[];
86 #endif
87 
88 /* 512 is poor choice for ethernet, MTU is typically 1500.
89  * Minus eth.hdrs thats 1468.  Can get 2x better throughput with
90  * almost-MTU block sizes.  At least try... fall back to 512 if need be.
91  * (but those using CONFIG_IP_DEFRAG may want to set a larger block in cfg file)
92  */
93 #ifdef CONFIG_TFTP_BLOCKSIZE
94 #define TFTP_MTU_BLOCKSIZE CONFIG_TFTP_BLOCKSIZE
95 #else
96 #define TFTP_MTU_BLOCKSIZE 1468
97 #endif
98 
99 static unsigned short TftpBlkSize=TFTP_BLOCK_SIZE;
100 static unsigned short TftpBlkSizeOption=TFTP_MTU_BLOCKSIZE;
101 
102 #ifdef CONFIG_MCAST_TFTP
103 #include <malloc.h>
104 #define MTFTP_BITMAPSIZE	0x1000
105 static unsigned *Bitmap;
106 static int PrevBitmapHole,Mapsize=MTFTP_BITMAPSIZE;
107 static uchar ProhibitMcast=0, MasterClient=0;
108 static uchar Multicast=0;
109 extern IPaddr_t Mcast_addr;
110 static int Mcast_port;
111 static ulong TftpEndingBlock; /* can get 'last' block before done..*/
112 
113 static void parse_multicast_oack(char *pkt,int len);
114 
115 static void
116 mcast_cleanup(void)
117 {
118 	if (Mcast_addr) eth_mcast_join(Mcast_addr, 0);
119 	if (Bitmap) free(Bitmap);
120 	Bitmap=NULL;
121 	Mcast_addr = Multicast = Mcast_port = 0;
122 	TftpEndingBlock = -1;
123 }
124 
125 #endif	/* CONFIG_MCAST_TFTP */
126 
127 static __inline__ void
128 store_block (unsigned block, uchar * src, unsigned len)
129 {
130 	ulong offset = block * TftpBlkSize + TftpBlockWrapOffset;
131 	ulong newsize = offset + len;
132 #ifdef CONFIG_SYS_DIRECT_FLASH_TFTP
133 	int i, rc = 0;
134 
135 	for (i=0; i<CONFIG_SYS_MAX_FLASH_BANKS; i++) {
136 		/* start address in flash? */
137 		if (flash_info[i].flash_id == FLASH_UNKNOWN)
138 			continue;
139 		if (load_addr + offset >= flash_info[i].start[0]) {
140 			rc = 1;
141 			break;
142 		}
143 	}
144 
145 	if (rc) { /* Flash is destination for this packet */
146 		rc = flash_write ((char *)src, (ulong)(load_addr+offset), len);
147 		if (rc) {
148 			flash_perror (rc);
149 			NetState = NETLOOP_FAIL;
150 			return;
151 		}
152 	}
153 	else
154 #endif /* CONFIG_SYS_DIRECT_FLASH_TFTP */
155 	{
156 		(void)memcpy((void *)(load_addr + offset), src, len);
157 	}
158 #ifdef CONFIG_MCAST_TFTP
159 	if (Multicast)
160 		ext2_set_bit(block, Bitmap);
161 #endif
162 
163 	if (NetBootFileXferSize < newsize)
164 		NetBootFileXferSize = newsize;
165 }
166 
167 static void TftpSend (void);
168 static void TftpTimeout (void);
169 
170 /**********************************************************************/
171 
172 static void
173 TftpSend (void)
174 {
175 	volatile uchar *	pkt;
176 	volatile uchar *	xp;
177 	int			len = 0;
178 	volatile ushort *s;
179 
180 #ifdef CONFIG_MCAST_TFTP
181 	/* Multicast TFTP.. non-MasterClients do not ACK data. */
182 	if (Multicast
183 	 && (TftpState == STATE_DATA)
184 	 && (MasterClient == 0))
185 		return;
186 #endif
187 	/*
188 	 *	We will always be sending some sort of packet, so
189 	 *	cobble together the packet headers now.
190 	 */
191 	pkt = NetTxPacket + NetEthHdrSize() + IP_HDR_SIZE;
192 
193 	switch (TftpState) {
194 
195 	case STATE_RRQ:
196 		xp = pkt;
197 		s = (ushort *)pkt;
198 		*s++ = htons(TFTP_RRQ);
199 		pkt = (uchar *)s;
200 		strcpy ((char *)pkt, tftp_filename);
201 		pkt += strlen(tftp_filename) + 1;
202 		strcpy ((char *)pkt, "octet");
203 		pkt += 5 /*strlen("octet")*/ + 1;
204 		strcpy ((char *)pkt, "timeout");
205 		pkt += 7 /*strlen("timeout")*/ + 1;
206 		sprintf((char *)pkt, "%lu", TIMEOUT / 1000);
207 		debug("send option \"timeout %s\"\n", (char *)pkt);
208 		pkt += strlen((char *)pkt) + 1;
209 #ifdef CONFIG_TFTP_TSIZE
210 		memcpy((char *)pkt, "tsize\0000\0", 8);
211 		pkt += 8;
212 #endif
213 		/* try for more effic. blk size */
214 		pkt += sprintf((char *)pkt,"blksize%c%d%c",
215 				0,TftpBlkSizeOption,0);
216 #ifdef CONFIG_MCAST_TFTP
217 		/* Check all preconditions before even trying the option */
218 		if (!ProhibitMcast
219 		 && (Bitmap=malloc(Mapsize))
220 		 && eth_get_dev()->mcast) {
221 			free(Bitmap);
222 			Bitmap=NULL;
223 			pkt += sprintf((char *)pkt,"multicast%c%c",0,0);
224 		}
225 #endif /* CONFIG_MCAST_TFTP */
226 		len = pkt - xp;
227 		break;
228 
229 	case STATE_OACK:
230 #ifdef CONFIG_MCAST_TFTP
231 		/* My turn!  Start at where I need blocks I missed.*/
232 		if (Multicast)
233 			TftpBlock=ext2_find_next_zero_bit(Bitmap,(Mapsize*8),0);
234 		/*..falling..*/
235 #endif
236 	case STATE_DATA:
237 		xp = pkt;
238 		s = (ushort *)pkt;
239 		*s++ = htons(TFTP_ACK);
240 		*s++ = htons(TftpBlock);
241 		pkt = (uchar *)s;
242 		len = pkt - xp;
243 		break;
244 
245 	case STATE_TOO_LARGE:
246 		xp = pkt;
247 		s = (ushort *)pkt;
248 		*s++ = htons(TFTP_ERROR);
249 		*s++ = htons(3);
250 		pkt = (uchar *)s;
251 		strcpy ((char *)pkt, "File too large");
252 		pkt += 14 /*strlen("File too large")*/ + 1;
253 		len = pkt - xp;
254 		break;
255 
256 	case STATE_BAD_MAGIC:
257 		xp = pkt;
258 		s = (ushort *)pkt;
259 		*s++ = htons(TFTP_ERROR);
260 		*s++ = htons(2);
261 		pkt = (uchar *)s;
262 		strcpy ((char *)pkt, "File has bad magic");
263 		pkt += 18 /*strlen("File has bad magic")*/ + 1;
264 		len = pkt - xp;
265 		break;
266 	}
267 
268 	NetSendUDPPacket(NetServerEther, TftpServerIP, TftpServerPort, TftpOurPort, len);
269 }
270 
271 
272 static void
273 TftpHandler (uchar * pkt, unsigned dest, unsigned src, unsigned len)
274 {
275 	ushort proto;
276 	ushort *s;
277 	int i;
278 
279 	if (dest != TftpOurPort) {
280 #ifdef CONFIG_MCAST_TFTP
281 		if (Multicast
282 		 && (!Mcast_port || (dest != Mcast_port)))
283 #endif
284 		return;
285 	}
286 	if (TftpState != STATE_RRQ && src != TftpServerPort) {
287 		return;
288 	}
289 
290 	if (len < 2) {
291 		return;
292 	}
293 	len -= 2;
294 	/* warning: don't use increment (++) in ntohs() macros!! */
295 	s = (ushort *)pkt;
296 	proto = *s++;
297 	pkt = (uchar *)s;
298 	switch (ntohs(proto)) {
299 
300 	case TFTP_RRQ:
301 	case TFTP_WRQ:
302 	case TFTP_ACK:
303 		break;
304 	default:
305 		break;
306 
307 	case TFTP_OACK:
308 		debug("Got OACK: %s %s\n",
309 			pkt,
310 			pkt + strlen((char *)pkt) + 1);
311 		TftpState = STATE_OACK;
312 		TftpServerPort = src;
313 		/*
314 		 * Check for 'blksize' option.
315 		 * Careful: "i" is signed, "len" is unsigned, thus
316 		 * something like "len-8" may give a *huge* number
317 		 */
318 		for (i=0; i+8<len; i++) {
319 			if (strcmp ((char*)pkt+i,"blksize") == 0) {
320 				TftpBlkSize = (unsigned short)
321 					simple_strtoul((char*)pkt+i+8,NULL,10);
322 				debug("Blocksize ack: %s, %d\n",
323 					(char*)pkt+i+8,TftpBlkSize);
324 			}
325 #ifdef CONFIG_TFTP_TSIZE
326 			if (strcmp ((char*)pkt+i,"tsize") == 0) {
327 				TftpTsize = simple_strtoul((char*)pkt+i+6,NULL,10);
328 				debug("size = %s, %d\n",
329 					 (char*)pkt+i+6, TftpTsize);
330 			}
331 #endif
332 		}
333 #ifdef CONFIG_MCAST_TFTP
334 		parse_multicast_oack((char *)pkt,len-1);
335 		if ((Multicast) && (!MasterClient))
336 			TftpState = STATE_DATA;	/* passive.. */
337 		else
338 #endif
339 		TftpSend (); /* Send ACK */
340 		break;
341 	case TFTP_DATA:
342 		if (len < 2)
343 			return;
344 		len -= 2;
345 		TftpBlock = ntohs(*(ushort *)pkt);
346 
347 		/*
348 		 * RFC1350 specifies that the first data packet will
349 		 * have sequence number 1. If we receive a sequence
350 		 * number of 0 this means that there was a wrap
351 		 * around of the (16 bit) counter.
352 		 */
353 		if (TftpBlock == 0) {
354 			TftpBlockWrap++;
355 			TftpBlockWrapOffset += TftpBlkSize * TFTP_SEQUENCE_SIZE;
356 			printf ("\n\t %lu MB received\n\t ", TftpBlockWrapOffset>>20);
357 		}
358 #ifdef CONFIG_TFTP_TSIZE
359 		else if (TftpTsize) {
360 			while (TftpNumchars < NetBootFileXferSize * 50 / TftpTsize) {
361 				putc('#');
362 				TftpNumchars++;
363 			}
364 		}
365 #endif
366 		else {
367 			if (((TftpBlock - 1) % 10) == 0) {
368 				putc ('#');
369 			} else if ((TftpBlock % (10 * HASHES_PER_LINE)) == 0) {
370 				puts ("\n\t ");
371 			}
372 		}
373 
374 		if (TftpState == STATE_RRQ)
375 			debug("Server did not acknowledge timeout option!\n");
376 
377 		if (TftpState == STATE_RRQ || TftpState == STATE_OACK) {
378 			/* first block received */
379 			TftpState = STATE_DATA;
380 			TftpServerPort = src;
381 			TftpLastBlock = 0;
382 			TftpBlockWrap = 0;
383 			TftpBlockWrapOffset = 0;
384 
385 #ifdef CONFIG_MCAST_TFTP
386 			if (Multicast) { /* start!=1 common if mcast */
387 				TftpLastBlock = TftpBlock - 1;
388 			} else
389 #endif
390 			if (TftpBlock != 1) {	/* Assertion */
391 				printf ("\nTFTP error: "
392 					"First block is not block 1 (%ld)\n"
393 					"Starting again\n\n",
394 					TftpBlock);
395 				NetStartAgain ();
396 				break;
397 			}
398 		}
399 
400 		if (TftpBlock == TftpLastBlock) {
401 			/*
402 			 *	Same block again; ignore it.
403 			 */
404 			break;
405 		}
406 
407 		TftpLastBlock = TftpBlock;
408 		TftpTimeoutMSecs = TIMEOUT;
409 		TftpTimeoutCountMax = TIMEOUT_COUNT;
410 		NetSetTimeout (TftpTimeoutMSecs, TftpTimeout);
411 
412 		store_block (TftpBlock - 1, pkt + 2, len);
413 
414 		/*
415 		 *	Acknoledge the block just received, which will prompt
416 		 *	the server for the next one.
417 		 */
418 #ifdef CONFIG_MCAST_TFTP
419 		/* if I am the MasterClient, actively calculate what my next
420 		 * needed block is; else I'm passive; not ACKING
421 		 */
422 		if (Multicast) {
423 			if (len < TftpBlkSize)  {
424 				TftpEndingBlock = TftpBlock;
425 			} else if (MasterClient) {
426 				TftpBlock = PrevBitmapHole =
427 					ext2_find_next_zero_bit(
428 						Bitmap,
429 						(Mapsize*8),
430 						PrevBitmapHole);
431 				if (TftpBlock > ((Mapsize*8) - 1)) {
432 					printf ("tftpfile too big\n");
433 					/* try to double it and retry */
434 					Mapsize<<=1;
435 					mcast_cleanup();
436 					NetStartAgain ();
437 					return;
438 				}
439 				TftpLastBlock = TftpBlock;
440 			}
441 		}
442 #endif
443 		TftpSend ();
444 
445 #ifdef CONFIG_MCAST_TFTP
446 		if (Multicast) {
447 			if (MasterClient && (TftpBlock >= TftpEndingBlock)) {
448 				puts ("\nMulticast tftp done\n");
449 				mcast_cleanup();
450 				NetState = NETLOOP_SUCCESS;
451 			}
452 		}
453 		else
454 #endif
455 		if (len < TftpBlkSize) {
456 			/*
457 			 *	We received the whole thing.  Try to
458 			 *	run it.
459 			 */
460 #ifdef CONFIG_TFTP_TSIZE
461 			/* Print out the hash marks for the last packet received */
462 			while (TftpTsize && TftpNumchars < 49) {
463 				putc('#');
464 				TftpNumchars++;
465 			}
466 #endif
467 			puts ("\ndone\n");
468 			NetState = NETLOOP_SUCCESS;
469 		}
470 		break;
471 
472 	case TFTP_ERROR:
473 		printf ("\nTFTP error: '%s' (%d)\n",
474 					pkt + 2, ntohs(*(ushort *)pkt));
475 		puts ("Starting again\n\n");
476 #ifdef CONFIG_MCAST_TFTP
477 		mcast_cleanup();
478 #endif
479 		NetStartAgain ();
480 		break;
481 	}
482 }
483 
484 
485 static void
486 TftpTimeout (void)
487 {
488 	if (++TftpTimeoutCount > TftpTimeoutCountMax) {
489 		puts ("\nRetry count exceeded; starting again\n");
490 #ifdef CONFIG_MCAST_TFTP
491 		mcast_cleanup();
492 #endif
493 		NetStartAgain ();
494 	} else {
495 		puts ("T ");
496 		NetSetTimeout (TftpTimeoutMSecs, TftpTimeout);
497 		TftpSend ();
498 	}
499 }
500 
501 
502 void
503 TftpStart (void)
504 {
505 	char *ep;             /* Environment pointer */
506 
507 	/* Allow the user to choose tftpblocksize */
508 	if ((ep = getenv("tftpblocksize")) != NULL)
509 		TftpBlkSizeOption = simple_strtol(ep, NULL, 10);
510 	debug("tftp block size is %i\n", TftpBlkSizeOption);
511 
512 	TftpServerIP = NetServerIP;
513 	if (BootFile[0] == '\0') {
514 		sprintf(default_filename, "%02lX%02lX%02lX%02lX.img",
515 			NetOurIP & 0xFF,
516 			(NetOurIP >>  8) & 0xFF,
517 			(NetOurIP >> 16) & 0xFF,
518 			(NetOurIP >> 24) & 0xFF	);
519 
520 		strncpy(tftp_filename, default_filename, MAX_LEN);
521 		tftp_filename[MAX_LEN-1] = 0;
522 
523 		printf ("*** Warning: no boot file name; using '%s'\n",
524 			tftp_filename);
525 	} else {
526 		char *p = strchr (BootFile, ':');
527 
528 		if (p == NULL) {
529 			strncpy(tftp_filename, BootFile, MAX_LEN);
530 			tftp_filename[MAX_LEN-1] = 0;
531 		} else {
532 			TftpServerIP = string_to_ip (BootFile);
533 			strncpy(tftp_filename, p + 1, MAX_LEN);
534 			tftp_filename[MAX_LEN-1] = 0;
535 		}
536 	}
537 
538 #if defined(CONFIG_NET_MULTI)
539 	printf ("Using %s device\n", eth_get_name());
540 #endif
541 	printf("TFTP from server %pI4"
542 		"; our IP address is %pI4", &TftpServerIP, &NetOurIP);
543 
544 	/* Check if we need to send across this subnet */
545 	if (NetOurGatewayIP && NetOurSubnetMask) {
546 	    IPaddr_t OurNet	= NetOurIP    & NetOurSubnetMask;
547 	    IPaddr_t ServerNet	= TftpServerIP & NetOurSubnetMask;
548 
549 	    if (OurNet != ServerNet)
550 		printf("; sending through gateway %pI4", &NetOurGatewayIP);
551 	}
552 	putc ('\n');
553 
554 	printf ("Filename '%s'.", tftp_filename);
555 
556 	if (NetBootFileSize) {
557 		printf (" Size is 0x%x Bytes = ", NetBootFileSize<<9);
558 		print_size (NetBootFileSize<<9, "");
559 	}
560 
561 	putc ('\n');
562 
563 	printf ("Load address: 0x%lx\n", load_addr);
564 
565 	puts ("Loading: *\b");
566 
567 	TftpTimeoutMSecs = TftpRRQTimeoutMSecs;
568 	TftpTimeoutCountMax = TftpRRQTimeoutCountMax;
569 
570 	NetSetTimeout (TftpTimeoutMSecs, TftpTimeout);
571 	NetSetHandler (TftpHandler);
572 
573 	TftpServerPort = WELL_KNOWN_PORT;
574 	TftpTimeoutCount = 0;
575 	TftpState = STATE_RRQ;
576 	/* Use a pseudo-random port unless a specific port is set */
577 	TftpOurPort = 1024 + (get_timer(0) % 3072);
578 
579 #ifdef CONFIG_TFTP_PORT
580 	if ((ep = getenv("tftpdstp")) != NULL) {
581 		TftpServerPort = simple_strtol(ep, NULL, 10);
582 	}
583 	if ((ep = getenv("tftpsrcp")) != NULL) {
584 		TftpOurPort= simple_strtol(ep, NULL, 10);
585 	}
586 #endif
587 	TftpBlock = 0;
588 
589 	/* zero out server ether in case the server ip has changed */
590 	memset(NetServerEther, 0, 6);
591 	/* Revert TftpBlkSize to dflt */
592 	TftpBlkSize = TFTP_BLOCK_SIZE;
593 #ifdef CONFIG_MCAST_TFTP
594 	mcast_cleanup();
595 #endif
596 #ifdef CONFIG_TFTP_TSIZE
597 	TftpTsize = 0;
598 	TftpNumchars = 0;
599 #endif
600 
601 	TftpSend ();
602 }
603 
604 #ifdef CONFIG_MCAST_TFTP
605 /* Credits: atftp project.
606  */
607 
608 /* pick up BcastAddr, Port, and whether I am [now] the master-client. *
609  * Frame:
610  *    +-------+-----------+---+-------~~-------+---+
611  *    |  opc  | multicast | 0 | addr, port, mc | 0 |
612  *    +-------+-----------+---+-------~~-------+---+
613  * The multicast addr/port becomes what I listen to, and if 'mc' is '1' then
614  * I am the new master-client so must send ACKs to DataBlocks.  If I am not
615  * master-client, I'm a passive client, gathering what DataBlocks I may and
616  * making note of which ones I got in my bitmask.
617  * In theory, I never go from master->passive..
618  * .. this comes in with pkt already pointing just past opc
619  */
620 static void parse_multicast_oack(char *pkt, int len)
621 {
622  int i;
623  IPaddr_t addr;
624  char *mc_adr, *port,  *mc;
625 
626 	mc_adr=port=mc=NULL;
627 	/* march along looking for 'multicast\0', which has to start at least
628 	 * 14 bytes back from the end.
629 	 */
630 	for (i=0;i<len-14;i++)
631 		if (strcmp (pkt+i,"multicast") == 0)
632 			break;
633 	if (i >= (len-14)) /* non-Multicast OACK, ign. */
634 		return;
635 
636 	i+=10; /* strlen multicast */
637 	mc_adr = pkt+i;
638 	for (;i<len;i++) {
639 		if (*(pkt+i) == ',') {
640 			*(pkt+i) = '\0';
641 			if (port) {
642 				mc = pkt+i+1;
643 				break;
644 			} else {
645 				port = pkt+i+1;
646 			}
647 		}
648 	}
649 	if (!port || !mc_adr || !mc ) return;
650 	if (Multicast && MasterClient) {
651 		printf ("I got a OACK as master Client, WRONG!\n");
652 		return;
653 	}
654 	/* ..I now accept packets destined for this MCAST addr, port */
655 	if (!Multicast) {
656 		if (Bitmap) {
657 			printf ("Internal failure! no mcast.\n");
658 			free(Bitmap);
659 			Bitmap=NULL;
660 			ProhibitMcast=1;
661 			return ;
662 		}
663 		/* I malloc instead of pre-declare; so that if the file ends
664 		 * up being too big for this bitmap I can retry
665 		 */
666 		if (!(Bitmap = malloc (Mapsize))) {
667 			printf ("No Bitmap, no multicast. Sorry.\n");
668 			ProhibitMcast=1;
669 			return;
670 		}
671 		memset (Bitmap,0,Mapsize);
672 		PrevBitmapHole = 0;
673 		Multicast = 1;
674 	}
675 	addr = string_to_ip(mc_adr);
676 	if (Mcast_addr != addr) {
677 		if (Mcast_addr)
678 			eth_mcast_join(Mcast_addr, 0);
679 		if (eth_mcast_join(Mcast_addr=addr, 1)) {
680 			printf ("Fail to set mcast, revert to TFTP\n");
681 			ProhibitMcast=1;
682 			mcast_cleanup();
683 			NetStartAgain();
684 		}
685 	}
686 	MasterClient = (unsigned char)simple_strtoul((char *)mc,NULL,10);
687 	Mcast_port = (unsigned short)simple_strtoul(port,NULL,10);
688 	printf ("Multicast: %s:%d [%d]\n", mc_adr, Mcast_port, MasterClient);
689 	return;
690 }
691 
692 #endif /* Multicast TFTP */
693 
694 #endif
695