1 /* $NetBSD: tftp.c,v 1.4 1997/09/17 16:57:07 drochner Exp $ */
2
3 /*
4 * Copyright (c) 1996
5 * Matthias Drochner. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed for the NetBSD Project
18 * by Matthias Drochner.
19 * 4. The name of the author may not be used to endorse or promote products
20 * derived from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include <sys/cdefs.h>
35
36 /*
37 * Simple TFTP implementation for libsa.
38 * Assumes:
39 * - socket descriptor (int) at open_file->f_devdata
40 * - server host IP in global servip
41 * Restrictions:
42 * - read only
43 * - lseek only with SEEK_SET or SEEK_CUR
44 * - no big time differences between transfers (<tftp timeout)
45 */
46
47 #include <sys/types.h>
48 #include <sys/stat.h>
49 #include <netinet/in.h>
50 #include <netinet/udp.h>
51 #include <netinet/in_systm.h>
52 #include <arpa/tftp.h>
53
54 #include <string.h>
55
56 #include "stand.h"
57 #include "net.h"
58 #include "netif.h"
59
60 #include "tftp.h"
61
62 struct tftp_handle;
63
64 static int tftp_open(const char *path, struct open_file *f);
65 static int tftp_close(struct open_file *f);
66 static int tftp_parse_oack(struct tftp_handle *h, char *buf, size_t len);
67 static int tftp_read(struct open_file *f, void *buf, size_t size, size_t *resid);
68 static off_t tftp_seek(struct open_file *f, off_t offset, int where);
69 static int tftp_set_blksize(struct tftp_handle *h, const char *str);
70 static int tftp_stat(struct open_file *f, struct stat *sb);
71 static ssize_t sendrecv_tftp(struct tftp_handle *h,
72 ssize_t (*sproc)(struct iodesc *, void *, size_t),
73 void *sbuf, size_t ssize,
74 ssize_t (*rproc)(struct tftp_handle *h, void **, void **, time_t, unsigned short *),
75 void **, void **, unsigned short *rtype);
76
77 struct fs_ops tftp_fsops = {
78 "tftp",
79 tftp_open,
80 tftp_close,
81 tftp_read,
82 null_write,
83 tftp_seek,
84 tftp_stat,
85 null_readdir
86 };
87
88 extern struct in_addr servip;
89
90 static int tftpport = 2000;
91 static int is_open = 0;
92
93 /*
94 * The legacy TFTP_BLKSIZE value was SEGSIZE(512).
95 * TFTP_REQUESTED_BLKSIZE of 1428 is (Ethernet MTU, less the TFTP, UDP and
96 * IP header lengths).
97 */
98 #define TFTP_REQUESTED_BLKSIZE 1428
99
100 /*
101 * Choose a blksize big enough so we can test with Ethernet
102 * Jumbo frames in the future.
103 */
104 #define TFTP_MAX_BLKSIZE 9008
105
106 struct tftp_handle {
107 struct iodesc *iodesc;
108 int currblock; /* contents of lastdata */
109 int islastblock; /* flag */
110 int validsize;
111 int off;
112 char *path; /* saved for re-requests */
113 unsigned int tftp_blksize;
114 unsigned long tftp_tsize;
115 void *pkt;
116 struct tftphdr *tftp_hdr;
117 };
118
119 #define TFTP_MAX_ERRCODE EOPTNEG
120 static const int tftperrors[TFTP_MAX_ERRCODE + 1] = {
121 0, /* ??? */
122 ENOENT,
123 EPERM,
124 ENOSPC,
125 EINVAL, /* ??? */
126 EINVAL, /* ??? */
127 EEXIST,
128 EINVAL, /* ??? */
129 EINVAL, /* Option negotiation failed. */
130 };
131
132 static int tftp_getnextblock(struct tftp_handle *h);
133
134 /* send error message back. */
135 static void
136 tftp_senderr(struct tftp_handle *h, u_short errcode, const char *msg)
137 {
138 struct {
139 u_char header[HEADER_SIZE];
140 struct tftphdr t;
141 u_char space[63]; /* +1 from t */
142 } __packed __aligned(4) wbuf;
143 char *wtail;
144 int len;
145
146 len = strlen(msg);
147 if (len > sizeof(wbuf.space))
148 len = sizeof(wbuf.space);
149
150 wbuf.t.th_opcode = htons((u_short) ERROR);
151 wbuf.t.th_code = htons(errcode);
152
153 wtail = wbuf.t.th_msg;
154 bcopy(msg, wtail, len);
155 wtail[len] = '\0';
156 wtail += len + 1;
157
158 sendudp(h->iodesc, &wbuf.t, wtail - (char *) &wbuf.t);
159 }
160
161 static void
162 tftp_sendack(struct tftp_handle *h)
163 {
164 struct {
165 u_char header[HEADER_SIZE];
166 struct tftphdr t;
167 } __packed __aligned(4) wbuf;
168 char *wtail;
169
170 wbuf.t.th_opcode = htons((u_short) ACK);
171 wtail = (char *) &wbuf.t.th_block;
172 wbuf.t.th_block = htons((u_short) h->currblock);
173 wtail += 2;
174
175 sendudp(h->iodesc, &wbuf.t, wtail - (char *) &wbuf.t);
176 }
177
178 static ssize_t
179 recvtftp(struct tftp_handle *h, void **pkt, void **payload, time_t tleft,
180 unsigned short *rtype)
181 {
182 struct iodesc *d = h->iodesc;
183 struct tftphdr *t;
184 void *ptr = NULL;
185 ssize_t len;
186
187 errno = 0;
188
189 len = readudp(d, &ptr, (void **)&t, tleft);
190
191 if (len < 4) {
192 free(ptr);
193 return (-1);
194 }
195
196 *rtype = ntohs(t->th_opcode);
197 switch (ntohs(t->th_opcode)) {
198 case DATA: {
199 int got;
200
201 if (htons(t->th_block) != (u_short) d->xid) {
202 /*
203 * Expected block?
204 */
205 free(ptr);
206 return (-1);
207 }
208 if (d->xid == 1) {
209 /*
210 * First data packet from new port.
211 */
212 struct udphdr *uh;
213 uh = (struct udphdr *) t - 1;
214 d->destport = uh->uh_sport;
215 } /* else check uh_sport has not changed??? */
216 got = len - (t->th_data - (char *)t);
217 *pkt = ptr;
218 *payload = t;
219 return (got);
220 }
221 case ERROR:
222 if ((unsigned) ntohs(t->th_code) > TFTP_MAX_ERRCODE) {
223 printf("illegal tftp error %d\n", ntohs(t->th_code));
224 errno = EIO;
225 } else {
226 #ifdef TFTP_DEBUG
227 printf("tftp-error %d\n", ntohs(t->th_code));
228 #endif
229 errno = tftperrors[ntohs(t->th_code)];
230 }
231 free(ptr);
232 return (-1);
233 case OACK: {
234 struct udphdr *uh;
235 int tftp_oack_len;
236
237 /*
238 * Unexpected OACK. TFTP transfer already in progress.
239 * Drop the pkt.
240 */
241 if (d->xid != 1) {
242 free(ptr);
243 return (-1);
244 }
245
246 /*
247 * Remember which port this OACK came from, because we need
248 * to send the ACK or errors back to it.
249 */
250 uh = (struct udphdr *) t - 1;
251 d->destport = uh->uh_sport;
252
253 /* Parse options ACK-ed by the server. */
254 tftp_oack_len = len - sizeof(t->th_opcode);
255 if (tftp_parse_oack(h, t->th_u.tu_stuff, tftp_oack_len) != 0) {
256 tftp_senderr(h, EOPTNEG, "Malformed OACK");
257 errno = EIO;
258 free(ptr);
259 return (-1);
260 }
261 *pkt = ptr;
262 *payload = t;
263 return (0);
264 }
265 default:
266 #ifdef TFTP_DEBUG
267 printf("tftp type %d not handled\n", ntohs(t->th_opcode));
268 #endif
269 free(ptr);
270 return (-1);
271 }
272 }
273
274 /* send request, expect first block (or error) */
275 static int
276 tftp_makereq(struct tftp_handle *h)
277 {
278 struct {
279 u_char header[HEADER_SIZE];
280 struct tftphdr t;
281 u_char space[FNAME_SIZE + 6];
282 } __packed __aligned(4) wbuf;
283 char *wtail;
284 int l;
285 ssize_t res;
286 void *pkt;
287 struct tftphdr *t;
288 char *tftp_blksize = NULL;
289 int blksize_l;
290 unsigned short rtype = 0;
291
292 /*
293 * Allow overriding default TFTP block size by setting
294 * a tftp.blksize environment variable.
295 */
296 if ((tftp_blksize = getenv("tftp.blksize")) != NULL) {
297 tftp_set_blksize(h, tftp_blksize);
298 }
299
300 wbuf.t.th_opcode = htons((u_short) RRQ);
301 wtail = wbuf.t.th_stuff;
302 l = strlen(h->path);
303 #ifdef TFTP_PREPEND_PATH
304 if (l > FNAME_SIZE - (sizeof(TFTP_PREPEND_PATH) - 1))
305 return (ENAMETOOLONG);
306 bcopy(TFTP_PREPEND_PATH, wtail, sizeof(TFTP_PREPEND_PATH) - 1);
307 wtail += sizeof(TFTP_PREPEND_PATH) - 1;
308 #else
309 if (l > FNAME_SIZE)
310 return (ENAMETOOLONG);
311 #endif
312 bcopy(h->path, wtail, l + 1);
313 wtail += l + 1;
314 bcopy("octet", wtail, 6);
315 wtail += 6;
316 bcopy("blksize", wtail, 8);
317 wtail += 8;
318 blksize_l = sprintf(wtail, "%d", h->tftp_blksize);
319 wtail += blksize_l + 1;
320 bcopy("tsize", wtail, 6);
321 wtail += 6;
322 bcopy("0", wtail, 2);
323 wtail += 2;
324
325 /* h->iodesc->myport = htons(--tftpport); */
326 h->iodesc->myport = htons(tftpport + (getsecs() & 0x3ff));
327 h->iodesc->destport = htons(IPPORT_TFTP);
328 h->iodesc->xid = 1; /* expected block */
329
330 h->currblock = 0;
331 h->islastblock = 0;
332 h->validsize = 0;
333
334 pkt = NULL;
335 res = sendrecv_tftp(h, &sendudp, &wbuf.t, wtail - (char *) &wbuf.t,
336 &recvtftp, &pkt, (void **)&t, &rtype);
337 if (res == -1) {
338 free(pkt);
339 return (errno);
340 }
341
342 free(h->pkt);
343 h->pkt = pkt;
344 h->tftp_hdr = t;
345
346 if (rtype == OACK)
347 return (tftp_getnextblock(h));
348
349 /* Server ignored our blksize request, revert to TFTP default. */
350 h->tftp_blksize = SEGSIZE;
351
352 switch (rtype) {
353 case DATA: {
354 h->currblock = 1;
355 h->validsize = res;
356 h->islastblock = 0;
357 if (res < h->tftp_blksize) {
358 h->islastblock = 1; /* very short file */
359 tftp_sendack(h);
360 }
361 return (0);
362 }
363 case ERROR:
364 default:
365 return (errno);
366 }
367
368 }
369
370 /* ack block, expect next */
371 static int
372 tftp_getnextblock(struct tftp_handle *h)
373 {
374 struct {
375 u_char header[HEADER_SIZE];
376 struct tftphdr t;
377 } __packed __aligned(4) wbuf;
378 char *wtail;
379 int res;
380 void *pkt;
381 struct tftphdr *t;
382 unsigned short rtype = 0;
383 wbuf.t.th_opcode = htons((u_short) ACK);
384 wtail = (char *) &wbuf.t.th_block;
385 wbuf.t.th_block = htons((u_short) h->currblock);
386 wtail += 2;
387
388 h->iodesc->xid = h->currblock + 1; /* expected block */
389
390 pkt = NULL;
391 res = sendrecv_tftp(h, &sendudp, &wbuf.t, wtail - (char *) &wbuf.t,
392 &recvtftp, &pkt, (void **)&t, &rtype);
393
394 if (res == -1) { /* 0 is OK! */
395 free(pkt);
396 return (errno);
397 }
398
399 free(h->pkt);
400 h->pkt = pkt;
401 h->tftp_hdr = t;
402 h->currblock++;
403 h->validsize = res;
404 if (res < h->tftp_blksize)
405 h->islastblock = 1; /* EOF */
406
407 if (h->islastblock == 1) {
408 /* Send an ACK for the last block */
409 wbuf.t.th_block = htons((u_short) h->currblock);
410 sendudp(h->iodesc, &wbuf.t, wtail - (char *)&wbuf.t);
411 }
412
413 return (0);
414 }
415
416 static int
417 tftp_open(const char *path, struct open_file *f)
418 {
419 struct tftp_handle *tftpfile;
420 struct iodesc *io;
421 int res;
422 size_t pathsize;
423 const char *extraslash;
424
425 if (netproto != NET_TFTP)
426 return (EINVAL);
427
428 if (f->f_dev->dv_type != DEVT_NET)
429 return (EINVAL);
430
431 if (is_open)
432 return (EBUSY);
433
434 tftpfile = (struct tftp_handle *) malloc(sizeof(*tftpfile));
435 if (!tftpfile)
436 return (ENOMEM);
437
438 memset(tftpfile, 0, sizeof(*tftpfile));
439 tftpfile->tftp_blksize = TFTP_REQUESTED_BLKSIZE;
440 tftpfile->iodesc = io = socktodesc(*(int *) (f->f_devdata));
441 if (io == NULL)
442 return (EINVAL);
443
444 io->destip = servip;
445 tftpfile->off = 0;
446 pathsize = (strlen(rootpath) + 1 + strlen(path) + 1) * sizeof(char);
447 tftpfile->path = malloc(pathsize);
448 if (tftpfile->path == NULL) {
449 free(tftpfile);
450 return(ENOMEM);
451 }
452 if (rootpath[strlen(rootpath) - 1] == '/' || path[0] == '/')
453 extraslash = "";
454 else
455 extraslash = "/";
456 res = snprintf(tftpfile->path, pathsize, "%s%s%s",
457 rootpath, extraslash, path);
458 if (res < 0 || res > pathsize) {
459 free(tftpfile->path);
460 free(tftpfile);
461 return(ENOMEM);
462 }
463
464 res = tftp_makereq(tftpfile);
465
466 if (res) {
467 free(tftpfile->path);
468 free(tftpfile->pkt);
469 free(tftpfile);
470 return (res);
471 }
472 f->f_fsdata = (void *) tftpfile;
473 is_open = 1;
474 return (0);
475 }
476
477 static int
478 tftp_read(struct open_file *f, void *addr, size_t size,
479 size_t *resid /* out */)
480 {
481 struct tftp_handle *tftpfile;
482 tftpfile = (struct tftp_handle *) f->f_fsdata;
483
484 while (size > 0) {
485 int needblock, count;
486
487 twiddle(32);
488
489 needblock = tftpfile->off / tftpfile->tftp_blksize + 1;
490
491 if (tftpfile->currblock > needblock) { /* seek backwards */
492 tftp_senderr(tftpfile, 0, "No error: read aborted");
493 tftp_makereq(tftpfile); /* no error check, it worked
494 * for open */
495 }
496
497 while (tftpfile->currblock < needblock) {
498 int res;
499
500 res = tftp_getnextblock(tftpfile);
501 if (res) { /* no answer */
502 #ifdef TFTP_DEBUG
503 printf("tftp: read error\n");
504 #endif
505 return (res);
506 }
507 if (tftpfile->islastblock)
508 break;
509 }
510
511 if (tftpfile->currblock == needblock) {
512 int offinblock, inbuffer;
513
514 offinblock = tftpfile->off % tftpfile->tftp_blksize;
515
516 inbuffer = tftpfile->validsize - offinblock;
517 if (inbuffer < 0) {
518 #ifdef TFTP_DEBUG
519 printf("tftp: invalid offset %d\n",
520 tftpfile->off);
521 #endif
522 return (EINVAL);
523 }
524 count = (size < inbuffer ? size : inbuffer);
525 bcopy(tftpfile->tftp_hdr->th_data + offinblock,
526 addr, count);
527
528 addr = (char *)addr + count;
529 tftpfile->off += count;
530 size -= count;
531
532 if ((tftpfile->islastblock) && (count == inbuffer))
533 break; /* EOF */
534 } else {
535 #ifdef TFTP_DEBUG
536 printf("tftp: block %d not found\n", needblock);
537 #endif
538 return (EINVAL);
539 }
540
541 }
542
543 if (resid)
544 *resid = size;
545 return (0);
546 }
547
548 static int
549 tftp_close(struct open_file *f)
550 {
551 struct tftp_handle *tftpfile;
552 tftpfile = (struct tftp_handle *) f->f_fsdata;
553
554 /* let it time out ... */
555
556 if (tftpfile) {
557 free(tftpfile->path);
558 free(tftpfile->pkt);
559 free(tftpfile);
560 }
561 is_open = 0;
562 return (0);
563 }
564
565 static int
566 tftp_stat(struct open_file *f, struct stat *sb)
567 {
568 struct tftp_handle *tftpfile;
569 tftpfile = (struct tftp_handle *) f->f_fsdata;
570
571 sb->st_mode = 0444 | S_IFREG;
572 sb->st_nlink = 1;
573 sb->st_uid = 0;
574 sb->st_gid = 0;
575 sb->st_size = (off_t) tftpfile->tftp_tsize;
576 return (0);
577 }
578
579 static off_t
580 tftp_seek(struct open_file *f, off_t offset, int where)
581 {
582 struct tftp_handle *tftpfile;
583 tftpfile = (struct tftp_handle *) f->f_fsdata;
584
585 switch (where) {
586 case SEEK_SET:
587 tftpfile->off = offset;
588 break;
589 case SEEK_CUR:
590 tftpfile->off += offset;
591 break;
592 default:
593 errno = EOFFSET;
594 return (-1);
595 }
596 return (tftpfile->off);
597 }
598
599 static ssize_t
600 sendrecv_tftp(struct tftp_handle *h,
601 ssize_t (*sproc)(struct iodesc *, void *, size_t),
602 void *sbuf, size_t ssize,
603 ssize_t (*rproc)(struct tftp_handle *, void **, void **, time_t,
604 unsigned short *),
605 void **pkt, void **payload, unsigned short *rtype)
606 {
607 struct iodesc *d = h->iodesc;
608 ssize_t cc;
609 time_t t, t1, tleft;
610
611 #ifdef TFTP_DEBUG
612 if (debug)
613 printf("sendrecv: called\n");
614 #endif
615
616 tleft = MINTMO;
617 t = t1 = getsecs();
618 for (;;) {
619 if ((getsecs() - t) > MAXTMO) {
620 errno = ETIMEDOUT;
621 return -1;
622 }
623
624 cc = (*sproc)(d, sbuf, ssize);
625 if (cc != -1 && cc < ssize)
626 panic("sendrecv: short write! (%zd < %zu)",
627 cc, ssize);
628
629 if (cc == -1) {
630 /* Error on transmit; wait before retrying */
631 while ((getsecs() - t1) < tleft);
632 t1 = getsecs();
633 continue;
634 }
635
636 t = t1 = getsecs();
637 recvnext:
638 if ((getsecs() - t) > MAXTMO) {
639 errno = ETIMEDOUT;
640 return (-1);
641 }
642 /* Try to get a packet and process it. */
643 cc = (*rproc)(h, pkt, payload, tleft, rtype);
644 /* Return on data, EOF or real error. */
645 if (cc != -1 || (errno != 0 && errno != ETIMEDOUT))
646 return (cc);
647 if ((getsecs() - t1) < tleft) {
648 goto recvnext;
649 }
650
651 /* Timed out or didn't get the packet we're waiting for */
652 tleft += MINTMO;
653 if (tleft > (2 * MINTMO)) {
654 tleft = (2 * MINTMO);
655 }
656 t1 = getsecs();
657 }
658 }
659
660 static int
661 tftp_set_blksize(struct tftp_handle *h, const char *str)
662 {
663 char *endptr;
664 int new_blksize;
665 int ret = 0;
666
667 if (h == NULL || str == NULL)
668 return (ret);
669
670 new_blksize =
671 (unsigned int)strtol(str, &endptr, 0);
672
673 /*
674 * Only accept blksize value if it is numeric.
675 * RFC2348 specifies that acceptable values are 8-65464.
676 * Let's choose a limit less than MAXRSPACE.
677 */
678 if (*endptr == '\0' && new_blksize >= 8
679 && new_blksize <= TFTP_MAX_BLKSIZE) {
680 h->tftp_blksize = new_blksize;
681 ret = 1;
682 }
683
684 return (ret);
685 }
686
687 /*
688 * In RFC2347, the TFTP Option Acknowledgement package (OACK)
689 * is used to acknowledge a client's option negotiation request.
690 * The format of an OACK packet is:
691 * +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+
692 * | opc | opt1 | 0 | value1 | 0 | optN | 0 | valueN | 0 |
693 * +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+
694 *
695 * opc
696 * The opcode field contains a 6, for Option Acknowledgment.
697 *
698 * opt1
699 * The first option acknowledgment, copied from the original
700 * request.
701 *
702 * value1
703 * The acknowledged value associated with the first option. If
704 * and how this value may differ from the original request is
705 * detailed in the specification for the option.
706 *
707 * optN, valueN
708 * The final option/value acknowledgment pair.
709 */
710 static int
711 tftp_parse_oack(struct tftp_handle *h, char *buf, size_t len)
712 {
713 /*
714 * We parse the OACK strings into an array
715 * of name-value pairs.
716 */
717 char *tftp_options[128] = { 0 };
718 char *val = buf;
719 int i = 0;
720 int option_idx = 0;
721 int blksize_is_set = 0;
722 int tsize = 0;
723
724 unsigned int orig_blksize;
725
726 while (option_idx < 128 && i < len) {
727 if (buf[i] == '\0') {
728 if (&buf[i] > val) {
729 tftp_options[option_idx] = val;
730 val = &buf[i] + 1;
731 ++option_idx;
732 }
733 }
734 ++i;
735 }
736
737 /* Save the block size we requested for sanity check later. */
738 orig_blksize = h->tftp_blksize;
739
740 /*
741 * Parse individual TFTP options.
742 * * "blksize" is specified in RFC2348.
743 * * "tsize" is specified in RFC2349.
744 */
745 for (i = 0; i < option_idx; i += 2) {
746 if (strcasecmp(tftp_options[i], "blksize") == 0) {
747 if (i + 1 < option_idx)
748 blksize_is_set =
749 tftp_set_blksize(h, tftp_options[i + 1]);
750 } else if (strcasecmp(tftp_options[i], "tsize") == 0) {
751 if (i + 1 < option_idx)
752 tsize = strtol(tftp_options[i + 1], (char **)NULL, 10);
753 if (tsize != 0)
754 h->tftp_tsize = tsize;
755 } else {
756 /* Do not allow any options we did not expect to be ACKed. */
757 printf("unexpected tftp option '%s'\n", tftp_options[i]);
758 return (-1);
759 }
760 }
761
762 if (!blksize_is_set) {
763 /*
764 * If TFTP blksize was not set, try defaulting
765 * to the legacy TFTP blksize of SEGSIZE(512)
766 */
767 h->tftp_blksize = SEGSIZE;
768 } else if (h->tftp_blksize > orig_blksize) {
769 /*
770 * Server should not be proposing block sizes that
771 * exceed what we said we can handle.
772 */
773 printf("unexpected blksize %u\n", h->tftp_blksize);
774 return (-1);
775 }
776
777 #ifdef TFTP_DEBUG
778 printf("tftp_blksize: %u\n", h->tftp_blksize);
779 printf("tftp_tsize: %lu\n", h->tftp_tsize);
780 #endif
781 return 0;
782 }