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TFTP: replace "server" with "remote" in local variable names
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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 /* Well known TFTP port # */
14 #define WELL_KNOWN_PORT 69
15 /* Millisecs to timeout for lost pkt */
16 #define TIMEOUT         5000UL
17 #ifndef CONFIG_NET_RETRY_COUNT
18 /* # of timeouts before giving up */
19 # define TIMEOUT_COUNT  10
20 #else
21 # define TIMEOUT_COUNT  (CONFIG_NET_RETRY_COUNT * 2)
22 #endif
23 /* Number of "loading" hashes per line (for checking the image size) */
24 #define HASHES_PER_LINE 65
25
26 /*
27  *      TFTP operations.
28  */
29 #define TFTP_RRQ        1
30 #define TFTP_WRQ        2
31 #define TFTP_DATA       3
32 #define TFTP_ACK        4
33 #define TFTP_ERROR      5
34 #define TFTP_OACK       6
35
36 static ulong TftpTimeoutMSecs = TIMEOUT;
37 static int TftpTimeoutCountMax = TIMEOUT_COUNT;
38
39 /*
40  * These globals govern the timeout behavior when attempting a connection to a
41  * TFTP server. TftpRRQTimeoutMSecs specifies the number of milliseconds to
42  * wait for the server to respond to initial connection. Second global,
43  * TftpRRQTimeoutCountMax, gives the number of such connection retries.
44  * TftpRRQTimeoutCountMax must be non-negative and TftpRRQTimeoutMSecs must be
45  * positive. The globals are meant to be set (and restored) by code needing
46  * non-standard timeout behavior when initiating a TFTP transfer.
47  */
48 ulong TftpRRQTimeoutMSecs = TIMEOUT;
49 int TftpRRQTimeoutCountMax = TIMEOUT_COUNT;
50
51 enum {
52         TFTP_ERR_UNDEFINED           = 0,
53         TFTP_ERR_FILE_NOT_FOUND      = 1,
54         TFTP_ERR_ACCESS_DENIED       = 2,
55         TFTP_ERR_DISK_FULL           = 3,
56         TFTP_ERR_UNEXPECTED_OPCODE   = 4,
57         TFTP_ERR_UNKNOWN_TRANSFER_ID  = 5,
58         TFTP_ERR_FILE_ALREADY_EXISTS = 6,
59 };
60
61 static IPaddr_t TftpRemoteIP;
62 /* The UDP port at their end */
63 static int      TftpRemotePort;
64 /* The UDP port at our end */
65 static int      TftpOurPort;
66 static int      TftpTimeoutCount;
67 /* packet sequence number */
68 static ulong    TftpBlock;
69 /* last packet sequence number received */
70 static ulong    TftpLastBlock;
71 /* count of sequence number wraparounds */
72 static ulong    TftpBlockWrap;
73 /* memory offset due to wrapping */
74 static ulong    TftpBlockWrapOffset;
75 static int      TftpState;
76 #ifdef CONFIG_TFTP_TSIZE
77 /* The file size reported by the server */
78 static int      TftpTsize;
79 /* The number of hashes we printed */
80 static short    TftpNumchars;
81 #endif
82
83 #define STATE_RRQ       1
84 #define STATE_DATA      2
85 #define STATE_TOO_LARGE 3
86 #define STATE_BAD_MAGIC 4
87 #define STATE_OACK      5
88
89 /* default TFTP block size */
90 #define TFTP_BLOCK_SIZE         512
91 /* sequence number is 16 bit */
92 #define TFTP_SEQUENCE_SIZE      ((ulong)(1<<16))
93
94 #define DEFAULT_NAME_LEN        (8 + 4 + 1)
95 static char default_filename[DEFAULT_NAME_LEN];
96
97 #ifndef CONFIG_TFTP_FILE_NAME_MAX_LEN
98 #define MAX_LEN 128
99 #else
100 #define MAX_LEN CONFIG_TFTP_FILE_NAME_MAX_LEN
101 #endif
102
103 static char tftp_filename[MAX_LEN];
104
105 #ifdef CONFIG_SYS_DIRECT_FLASH_TFTP
106 extern flash_info_t flash_info[];
107 #endif
108
109 /* 512 is poor choice for ethernet, MTU is typically 1500.
110  * Minus eth.hdrs thats 1468.  Can get 2x better throughput with
111  * almost-MTU block sizes.  At least try... fall back to 512 if need be.
112  * (but those using CONFIG_IP_DEFRAG may want to set a larger block in cfg file)
113  */
114 #ifdef CONFIG_TFTP_BLOCKSIZE
115 #define TFTP_MTU_BLOCKSIZE CONFIG_TFTP_BLOCKSIZE
116 #else
117 #define TFTP_MTU_BLOCKSIZE 1468
118 #endif
119
120 static unsigned short TftpBlkSize = TFTP_BLOCK_SIZE;
121 static unsigned short TftpBlkSizeOption = TFTP_MTU_BLOCKSIZE;
122
123 #ifdef CONFIG_MCAST_TFTP
124 #include <malloc.h>
125 #define MTFTP_BITMAPSIZE        0x1000
126 static unsigned *Bitmap;
127 static int PrevBitmapHole, Mapsize = MTFTP_BITMAPSIZE;
128 static uchar ProhibitMcast, MasterClient;
129 static uchar Multicast;
130 extern IPaddr_t Mcast_addr;
131 static int Mcast_port;
132 static ulong TftpEndingBlock; /* can get 'last' block before done..*/
133
134 static void parse_multicast_oack(char *pkt, int len);
135
136 static void
137 mcast_cleanup(void)
138 {
139         if (Mcast_addr)
140                 eth_mcast_join(Mcast_addr, 0);
141         if (Bitmap)
142                 free(Bitmap);
143         Bitmap = NULL;
144         Mcast_addr = Multicast = Mcast_port = 0;
145         TftpEndingBlock = -1;
146 }
147
148 #endif  /* CONFIG_MCAST_TFTP */
149
150 static __inline__ void
151 store_block(unsigned block, uchar *src, unsigned len)
152 {
153         ulong offset = block * TftpBlkSize + TftpBlockWrapOffset;
154         ulong newsize = offset + len;
155 #ifdef CONFIG_SYS_DIRECT_FLASH_TFTP
156         int i, rc = 0;
157
158         for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; i++) {
159                 /* start address in flash? */
160                 if (flash_info[i].flash_id == FLASH_UNKNOWN)
161                         continue;
162                 if (load_addr + offset >= flash_info[i].start[0]) {
163                         rc = 1;
164                         break;
165                 }
166         }
167
168         if (rc) { /* Flash is destination for this packet */
169                 rc = flash_write((char *)src, (ulong)(load_addr+offset), len);
170                 if (rc) {
171                         flash_perror(rc);
172                         NetState = NETLOOP_FAIL;
173                         return;
174                 }
175         }
176         else
177 #endif /* CONFIG_SYS_DIRECT_FLASH_TFTP */
178         {
179                 (void)memcpy((void *)(load_addr + offset), src, len);
180         }
181 #ifdef CONFIG_MCAST_TFTP
182         if (Multicast)
183                 ext2_set_bit(block, Bitmap);
184 #endif
185
186         if (NetBootFileXferSize < newsize)
187                 NetBootFileXferSize = newsize;
188 }
189
190 static void TftpSend(void);
191 static void TftpTimeout(void);
192
193 /**********************************************************************/
194
195 static void
196 TftpSend(void)
197 {
198         volatile uchar *pkt;
199         volatile uchar *xp;
200         int             len = 0;
201         volatile ushort *s;
202
203 #ifdef CONFIG_MCAST_TFTP
204         /* Multicast TFTP.. non-MasterClients do not ACK data. */
205         if (Multicast
206          && (TftpState == STATE_DATA)
207          && (MasterClient == 0))
208                 return;
209 #endif
210         /*
211          *      We will always be sending some sort of packet, so
212          *      cobble together the packet headers now.
213          */
214         pkt = NetTxPacket + NetEthHdrSize() + IP_HDR_SIZE;
215
216         switch (TftpState) {
217
218         case STATE_RRQ:
219                 xp = pkt;
220                 s = (ushort *)pkt;
221                 *s++ = htons(TFTP_RRQ);
222                 pkt = (uchar *)s;
223                 strcpy((char *)pkt, tftp_filename);
224                 pkt += strlen(tftp_filename) + 1;
225                 strcpy((char *)pkt, "octet");
226                 pkt += 5 /*strlen("octet")*/ + 1;
227                 strcpy((char *)pkt, "timeout");
228                 pkt += 7 /*strlen("timeout")*/ + 1;
229                 sprintf((char *)pkt, "%lu", TftpTimeoutMSecs / 1000);
230                 debug("send option \"timeout %s\"\n", (char *)pkt);
231                 pkt += strlen((char *)pkt) + 1;
232 #ifdef CONFIG_TFTP_TSIZE
233                 memcpy((char *)pkt, "tsize\0000\0", 8);
234                 pkt += 8;
235 #endif
236                 /* try for more effic. blk size */
237                 pkt += sprintf((char *)pkt, "blksize%c%d%c",
238                                 0, TftpBlkSizeOption, 0);
239 #ifdef CONFIG_MCAST_TFTP
240                 /* Check all preconditions before even trying the option */
241                 if (!ProhibitMcast
242                  && (Bitmap = malloc(Mapsize))
243                  && eth_get_dev()->mcast) {
244                         free(Bitmap);
245                         Bitmap = NULL;
246                         pkt += sprintf((char *)pkt, "multicast%c%c", 0, 0);
247                 }
248 #endif /* CONFIG_MCAST_TFTP */
249                 len = pkt - xp;
250                 break;
251
252         case STATE_OACK:
253 #ifdef CONFIG_MCAST_TFTP
254                 /* My turn!  Start at where I need blocks I missed.*/
255                 if (Multicast)
256                         TftpBlock = ext2_find_next_zero_bit(Bitmap,
257                                                             (Mapsize*8), 0);
258                 /*..falling..*/
259 #endif
260         case STATE_DATA:
261                 xp = pkt;
262                 s = (ushort *)pkt;
263                 *s++ = htons(TFTP_ACK);
264                 *s++ = htons(TftpBlock);
265                 pkt = (uchar *)s;
266                 len = pkt - xp;
267                 break;
268
269         case STATE_TOO_LARGE:
270                 xp = pkt;
271                 s = (ushort *)pkt;
272                 *s++ = htons(TFTP_ERROR);
273                 *s++ = htons(3);
274                 pkt = (uchar *)s;
275                 strcpy((char *)pkt, "File too large");
276                 pkt += 14 /*strlen("File too large")*/ + 1;
277                 len = pkt - xp;
278                 break;
279
280         case STATE_BAD_MAGIC:
281                 xp = pkt;
282                 s = (ushort *)pkt;
283                 *s++ = htons(TFTP_ERROR);
284                 *s++ = htons(2);
285                 pkt = (uchar *)s;
286                 strcpy((char *)pkt, "File has bad magic");
287                 pkt += 18 /*strlen("File has bad magic")*/ + 1;
288                 len = pkt - xp;
289                 break;
290         }
291
292         NetSendUDPPacket(NetServerEther, TftpRemoteIP, TftpRemotePort,
293                          TftpOurPort, len);
294 }
295
296
297 static void
298 TftpHandler(uchar *pkt, unsigned dest, IPaddr_t sip, unsigned src,
299             unsigned len)
300 {
301         ushort proto;
302         ushort *s;
303         int i;
304
305         if (dest != TftpOurPort) {
306 #ifdef CONFIG_MCAST_TFTP
307                 if (Multicast
308                  && (!Mcast_port || (dest != Mcast_port)))
309 #endif
310                         return;
311         }
312         if (TftpState != STATE_RRQ && src != TftpRemotePort)
313                 return;
314
315         if (len < 2)
316                 return;
317         len -= 2;
318         /* warning: don't use increment (++) in ntohs() macros!! */
319         s = (ushort *)pkt;
320         proto = *s++;
321         pkt = (uchar *)s;
322         switch (ntohs(proto)) {
323
324         case TFTP_RRQ:
325         case TFTP_WRQ:
326         case TFTP_ACK:
327                 break;
328         default:
329                 break;
330
331         case TFTP_OACK:
332                 debug("Got OACK: %s %s\n",
333                         pkt,
334                         pkt + strlen((char *)pkt) + 1);
335                 TftpState = STATE_OACK;
336                 TftpRemotePort = src;
337                 /*
338                  * Check for 'blksize' option.
339                  * Careful: "i" is signed, "len" is unsigned, thus
340                  * something like "len-8" may give a *huge* number
341                  */
342                 for (i = 0; i+8 < len; i++) {
343                         if (strcmp((char *)pkt+i, "blksize") == 0) {
344                                 TftpBlkSize = (unsigned short)
345                                         simple_strtoul((char *)pkt+i+8, NULL,
346                                                        10);
347                                 debug("Blocksize ack: %s, %d\n",
348                                         (char *)pkt+i+8, TftpBlkSize);
349                         }
350 #ifdef CONFIG_TFTP_TSIZE
351                         if (strcmp((char *)pkt+i, "tsize") == 0) {
352                                 TftpTsize = simple_strtoul((char *)pkt+i+6,
353                                                            NULL, 10);
354                                 debug("size = %s, %d\n",
355                                          (char *)pkt+i+6, TftpTsize);
356                         }
357 #endif
358                 }
359 #ifdef CONFIG_MCAST_TFTP
360                 parse_multicast_oack((char *)pkt, len-1);
361                 if ((Multicast) && (!MasterClient))
362                         TftpState = STATE_DATA; /* passive.. */
363                 else
364 #endif
365                 TftpSend(); /* Send ACK */
366                 break;
367         case TFTP_DATA:
368                 if (len < 2)
369                         return;
370                 len -= 2;
371                 TftpBlock = ntohs(*(ushort *)pkt);
372
373                 /*
374                  * RFC1350 specifies that the first data packet will
375                  * have sequence number 1. If we receive a sequence
376                  * number of 0 this means that there was a wrap
377                  * around of the (16 bit) counter.
378                  */
379                 if (TftpBlock == 0) {
380                         TftpBlockWrap++;
381                         TftpBlockWrapOffset +=
382                                 TftpBlkSize * TFTP_SEQUENCE_SIZE;
383                         printf("\n\t %lu MB received\n\t ",
384                                 TftpBlockWrapOffset>>20);
385                 }
386 #ifdef CONFIG_TFTP_TSIZE
387                 else if (TftpTsize) {
388                         while (TftpNumchars <
389                                NetBootFileXferSize * 50 / TftpTsize) {
390                                 putc('#');
391                                 TftpNumchars++;
392                         }
393                 }
394 #endif
395                 else {
396                         if (((TftpBlock - 1) % 10) == 0)
397                                 putc('#');
398                         else if ((TftpBlock % (10 * HASHES_PER_LINE)) == 0)
399                                 puts("\n\t ");
400                 }
401
402                 if (TftpState == STATE_RRQ)
403                         debug("Server did not acknowledge timeout option!\n");
404
405                 if (TftpState == STATE_RRQ || TftpState == STATE_OACK) {
406                         /* first block received */
407                         TftpState = STATE_DATA;
408                         TftpRemotePort = src;
409                         TftpLastBlock = 0;
410                         TftpBlockWrap = 0;
411                         TftpBlockWrapOffset = 0;
412
413 #ifdef CONFIG_MCAST_TFTP
414                         if (Multicast) { /* start!=1 common if mcast */
415                                 TftpLastBlock = TftpBlock - 1;
416                         } else
417 #endif
418                         if (TftpBlock != 1) {   /* Assertion */
419                                 printf("\nTFTP error: "
420                                        "First block is not block 1 (%ld)\n"
421                                        "Starting again\n\n",
422                                         TftpBlock);
423                                 NetStartAgain();
424                                 break;
425                         }
426                 }
427
428                 if (TftpBlock == TftpLastBlock) {
429                         /*
430                          *      Same block again; ignore it.
431                          */
432                         break;
433                 }
434
435                 TftpLastBlock = TftpBlock;
436                 TftpTimeoutCountMax = TIMEOUT_COUNT;
437                 NetSetTimeout(TftpTimeoutMSecs, TftpTimeout);
438
439                 store_block(TftpBlock - 1, pkt + 2, len);
440
441                 /*
442                  *      Acknoledge the block just received, which will prompt
443                  *      the remote for the next one.
444                  */
445 #ifdef CONFIG_MCAST_TFTP
446                 /* if I am the MasterClient, actively calculate what my next
447                  * needed block is; else I'm passive; not ACKING
448                  */
449                 if (Multicast) {
450                         if (len < TftpBlkSize)  {
451                                 TftpEndingBlock = TftpBlock;
452                         } else if (MasterClient) {
453                                 TftpBlock = PrevBitmapHole =
454                                         ext2_find_next_zero_bit(
455                                                 Bitmap,
456                                                 (Mapsize*8),
457                                                 PrevBitmapHole);
458                                 if (TftpBlock > ((Mapsize*8) - 1)) {
459                                         printf("tftpfile too big\n");
460                                         /* try to double it and retry */
461                                         Mapsize <<= 1;
462                                         mcast_cleanup();
463                                         NetStartAgain();
464                                         return;
465                                 }
466                                 TftpLastBlock = TftpBlock;
467                         }
468                 }
469 #endif
470                 TftpSend();
471
472 #ifdef CONFIG_MCAST_TFTP
473                 if (Multicast) {
474                         if (MasterClient && (TftpBlock >= TftpEndingBlock)) {
475                                 puts("\nMulticast tftp done\n");
476                                 mcast_cleanup();
477                                 NetState = NETLOOP_SUCCESS;
478                         }
479                 }
480                 else
481 #endif
482                 if (len < TftpBlkSize) {
483                         /*
484                          *      We received the whole thing.  Try to
485                          *      run it.
486                          */
487 #ifdef CONFIG_TFTP_TSIZE
488                         /* Print hash marks for the last packet received */
489                         while (TftpTsize && TftpNumchars < 49) {
490                                 putc('#');
491                                 TftpNumchars++;
492                         }
493 #endif
494                         puts("\ndone\n");
495                         NetState = NETLOOP_SUCCESS;
496                 }
497                 break;
498
499         case TFTP_ERROR:
500                 printf("\nTFTP error: '%s' (%d)\n",
501                        pkt + 2, ntohs(*(ushort *)pkt));
502
503                 switch (ntohs(*(ushort *)pkt)) {
504                 case TFTP_ERR_FILE_NOT_FOUND:
505                 case TFTP_ERR_ACCESS_DENIED:
506                         puts("Not retrying...\n");
507                         eth_halt();
508                         NetState = NETLOOP_FAIL;
509                         break;
510                 case TFTP_ERR_UNDEFINED:
511                 case TFTP_ERR_DISK_FULL:
512                 case TFTP_ERR_UNEXPECTED_OPCODE:
513                 case TFTP_ERR_UNKNOWN_TRANSFER_ID:
514                 case TFTP_ERR_FILE_ALREADY_EXISTS:
515                 default:
516                         puts("Starting again\n\n");
517 #ifdef CONFIG_MCAST_TFTP
518                         mcast_cleanup();
519 #endif
520                         NetStartAgain();
521                         break;
522                 }
523                 break;
524         }
525 }
526
527
528 static void
529 TftpTimeout(void)
530 {
531         if (++TftpTimeoutCount > TftpTimeoutCountMax) {
532                 puts("\nRetry count exceeded; starting again\n");
533 #ifdef CONFIG_MCAST_TFTP
534                 mcast_cleanup();
535 #endif
536                 NetStartAgain();
537         } else {
538                 puts("T ");
539                 NetSetTimeout(TftpTimeoutMSecs, TftpTimeout);
540                 TftpSend();
541         }
542 }
543
544
545 void
546 TftpStart(void)
547 {
548         char *ep;             /* Environment pointer */
549
550         /*
551          * Allow the user to choose TFTP blocksize and timeout.
552          * TFTP protocol has a minimal timeout of 1 second.
553          */
554         ep = getenv("tftpblocksize");
555         if (ep != NULL)
556                 TftpBlkSizeOption = simple_strtol(ep, NULL, 10);
557
558         ep = getenv("tftptimeout");
559         if (ep != NULL)
560                 TftpTimeoutMSecs = simple_strtol(ep, NULL, 10);
561
562         if (TftpTimeoutMSecs < 1000) {
563                 printf("TFTP timeout (%ld ms) too low, "
564                         "set minimum = 1000 ms\n",
565                         TftpTimeoutMSecs);
566                 TftpTimeoutMSecs = 1000;
567         }
568
569         debug("TFTP blocksize = %i, timeout = %ld ms\n",
570                 TftpBlkSizeOption, TftpTimeoutMSecs);
571
572         TftpRemoteIP = NetServerIP;
573         if (BootFile[0] == '\0') {
574                 sprintf(default_filename, "%02lX%02lX%02lX%02lX.img",
575                         NetOurIP & 0xFF,
576                         (NetOurIP >>  8) & 0xFF,
577                         (NetOurIP >> 16) & 0xFF,
578                         (NetOurIP >> 24) & 0xFF);
579
580                 strncpy(tftp_filename, default_filename, MAX_LEN);
581                 tftp_filename[MAX_LEN-1] = 0;
582
583                 printf("*** Warning: no boot file name; using '%s'\n",
584                         tftp_filename);
585         } else {
586                 char *p = strchr(BootFile, ':');
587
588                 if (p == NULL) {
589                         strncpy(tftp_filename, BootFile, MAX_LEN);
590                         tftp_filename[MAX_LEN-1] = 0;
591                 } else {
592                         TftpRemoteIP = string_to_ip(BootFile);
593                         strncpy(tftp_filename, p + 1, MAX_LEN);
594                         tftp_filename[MAX_LEN-1] = 0;
595                 }
596         }
597
598 #if defined(CONFIG_NET_MULTI)
599         printf("Using %s device\n", eth_get_name());
600 #endif
601         printf("TFTP from server %pI4"
602                 "; our IP address is %pI4", &TftpRemoteIP, &NetOurIP);
603
604         /* Check if we need to send across this subnet */
605         if (NetOurGatewayIP && NetOurSubnetMask) {
606                 IPaddr_t OurNet = NetOurIP    & NetOurSubnetMask;
607                 IPaddr_t RemoteNet      = TftpRemoteIP & NetOurSubnetMask;
608
609                 if (OurNet != RemoteNet)
610                         printf("; sending through gateway %pI4",
611                                &NetOurGatewayIP);
612         }
613         putc('\n');
614
615         printf("Filename '%s'.", tftp_filename);
616
617         if (NetBootFileSize) {
618                 printf(" Size is 0x%x Bytes = ", NetBootFileSize<<9);
619                 print_size(NetBootFileSize<<9, "");
620         }
621
622         putc('\n');
623
624         printf("Load address: 0x%lx\n", load_addr);
625
626         puts("Loading: *\b");
627
628         TftpTimeoutCountMax = TftpRRQTimeoutCountMax;
629
630         NetSetTimeout(TftpTimeoutMSecs, TftpTimeout);
631         NetSetHandler(TftpHandler);
632
633         TftpRemotePort = WELL_KNOWN_PORT;
634         TftpTimeoutCount = 0;
635         TftpState = STATE_RRQ;
636         /* Use a pseudo-random port unless a specific port is set */
637         TftpOurPort = 1024 + (get_timer(0) % 3072);
638
639 #ifdef CONFIG_TFTP_PORT
640         ep = getenv("tftpdstp");
641         if (ep != NULL)
642                 TftpRemotePort = simple_strtol(ep, NULL, 10);
643         ep = getenv("tftpsrcp");
644         if (ep != NULL)
645                 TftpOurPort = simple_strtol(ep, NULL, 10);
646 #endif
647         TftpBlock = 0;
648
649         /* zero out server ether in case the server ip has changed */
650         memset(NetServerEther, 0, 6);
651         /* Revert TftpBlkSize to dflt */
652         TftpBlkSize = TFTP_BLOCK_SIZE;
653 #ifdef CONFIG_MCAST_TFTP
654         mcast_cleanup();
655 #endif
656 #ifdef CONFIG_TFTP_TSIZE
657         TftpTsize = 0;
658         TftpNumchars = 0;
659 #endif
660
661         TftpSend();
662 }
663
664 #ifdef CONFIG_MCAST_TFTP
665 /* Credits: atftp project.
666  */
667
668 /* pick up BcastAddr, Port, and whether I am [now] the master-client. *
669  * Frame:
670  *    +-------+-----------+---+-------~~-------+---+
671  *    |  opc  | multicast | 0 | addr, port, mc | 0 |
672  *    +-------+-----------+---+-------~~-------+---+
673  * The multicast addr/port becomes what I listen to, and if 'mc' is '1' then
674  * I am the new master-client so must send ACKs to DataBlocks.  If I am not
675  * master-client, I'm a passive client, gathering what DataBlocks I may and
676  * making note of which ones I got in my bitmask.
677  * In theory, I never go from master->passive..
678  * .. this comes in with pkt already pointing just past opc
679  */
680 static void parse_multicast_oack(char *pkt, int len)
681 {
682         int i;
683         IPaddr_t addr;
684         char *mc_adr, *port,  *mc;
685
686         mc_adr = port = mc = NULL;
687         /* march along looking for 'multicast\0', which has to start at least
688          * 14 bytes back from the end.
689          */
690         for (i = 0; i < len-14; i++)
691                 if (strcmp(pkt+i, "multicast") == 0)
692                         break;
693         if (i >= (len-14)) /* non-Multicast OACK, ign. */
694                 return;
695
696         i += 10; /* strlen multicast */
697         mc_adr = pkt+i;
698         for (; i < len; i++) {
699                 if (*(pkt+i) == ',') {
700                         *(pkt+i) = '\0';
701                         if (port) {
702                                 mc = pkt+i+1;
703                                 break;
704                         } else {
705                                 port = pkt+i+1;
706                         }
707                 }
708         }
709         if (!port || !mc_adr || !mc)
710                 return;
711         if (Multicast && MasterClient) {
712                 printf("I got a OACK as master Client, WRONG!\n");
713                 return;
714         }
715         /* ..I now accept packets destined for this MCAST addr, port */
716         if (!Multicast) {
717                 if (Bitmap) {
718                         printf("Internal failure! no mcast.\n");
719                         free(Bitmap);
720                         Bitmap = NULL;
721                         ProhibitMcast = 1;
722                         return ;
723                 }
724                 /* I malloc instead of pre-declare; so that if the file ends
725                  * up being too big for this bitmap I can retry
726                  */
727                 Bitmap = malloc(Mapsize);
728                 if (!Bitmap) {
729                         printf("No Bitmap, no multicast. Sorry.\n");
730                         ProhibitMcast = 1;
731                         return;
732                 }
733                 memset(Bitmap, 0, Mapsize);
734                 PrevBitmapHole = 0;
735                 Multicast = 1;
736         }
737         addr = string_to_ip(mc_adr);
738         if (Mcast_addr != addr) {
739                 if (Mcast_addr)
740                         eth_mcast_join(Mcast_addr, 0);
741                 Mcast_addr = addr;
742                 if (eth_mcast_join(Mcast_addr, 1)) {
743                         printf("Fail to set mcast, revert to TFTP\n");
744                         ProhibitMcast = 1;
745                         mcast_cleanup();
746                         NetStartAgain();
747                 }
748         }
749         MasterClient = (unsigned char)simple_strtoul((char *)mc, NULL, 10);
750         Mcast_port = (unsigned short)simple_strtoul(port, NULL, 10);
751         printf("Multicast: %s:%d [%d]\n", mc_adr, Mcast_port, MasterClient);
752         return;
753 }
754
755 #endif /* Multicast TFTP */