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 __FBSDID("$FreeBSD$");
36
37 /*
38 * Simple TFTP implementation for libsa.
39 * Assumes:
40 * - socket descriptor (int) at open_file->f_devdata
41 * - server host IP in global servip
42 * Restrictions:
43 * - read only
44 * - lseek only with SEEK_SET or SEEK_CUR
45 * - no big time differences between transfers (<tftp timeout)
46 */
47
48 #include <sys/types.h>
49 #include <sys/stat.h>
50 #include <netinet/in.h>
51 #include <netinet/udp.h>
52 #include <netinet/in_systm.h>
53 #include <arpa/tftp.h>
54
55 #include <string.h>
56
57 #include "stand.h"
58 #include "net.h"
59 #include "netif.h"
60
61 #include "tftp.h"
62
63 struct tftp_handle;
64
65 static int tftp_open(const char *path, struct open_file *f);
66 static int tftp_close(struct open_file *f);
67 static int tftp_parse_oack(struct tftp_handle *h, char *buf, size_t len);
68 static int tftp_read(struct open_file *f, void *buf, size_t size, size_t *resid);
69 static int tftp_write(struct open_file *f, void *buf, size_t size, size_t *resid);
70 static off_t tftp_seek(struct open_file *f, off_t offset, int where);
71 static int tftp_set_blksize(struct tftp_handle *h, const char *str);
72 static int tftp_stat(struct open_file *f, struct stat *sb);
73 static ssize_t sendrecv_tftp(struct tftp_handle *h,
74 ssize_t (*sproc)(struct iodesc *, void *, size_t),
75 void *sbuf, size_t ssize,
76 ssize_t (*rproc)(struct tftp_handle *h, void *, ssize_t, time_t, unsigned short *),
77 void *rbuf, size_t rsize, unsigned short *rtype);
78
79 struct fs_ops tftp_fsops = {
80 "tftp",
81 tftp_open,
82 tftp_close,
83 tftp_read,
84 tftp_write,
85 tftp_seek,
86 tftp_stat,
87 null_readdir
88 };
89
90 extern struct in_addr servip;
91
92 static int tftpport = 2000;
93 static int is_open = 0;
94
95 /*
96 * The legacy TFTP_BLKSIZE value was SEGSIZE(512).
97 * TFTP_REQUESTED_BLKSIZE of 1428 is (Ethernet MTU, less the TFTP, UDP and
98 * IP header lengths).
99 */
100 #define TFTP_REQUESTED_BLKSIZE 1428
101
102 /*
103 * Choose a blksize big enough so we can test with Ethernet
104 * Jumbo frames in the future.
105 */
106 #define TFTP_MAX_BLKSIZE 9008
107
108 struct tftp_handle {
109 struct iodesc *iodesc;
110 int currblock; /* contents of lastdata */
111 int islastblock; /* flag */
112 int validsize;
113 int off;
114 char *path; /* saved for re-requests */
115 unsigned int tftp_blksize;
116 unsigned long tftp_tsize;
117 struct {
118 u_char header[HEADER_SIZE];
119 struct tftphdr t;
120 u_char space[TFTP_MAX_BLKSIZE];
121 } __packed __aligned(4) lastdata;
122 };
123
124 #define TFTP_MAX_ERRCODE EOPTNEG
125 static const int tftperrors[TFTP_MAX_ERRCODE + 1] = {
126 0, /* ??? */
127 ENOENT,
128 EPERM,
129 ENOSPC,
130 EINVAL, /* ??? */
131 EINVAL, /* ??? */
132 EEXIST,
133 EINVAL, /* ??? */
134 EINVAL, /* Option negotiation failed. */
135 };
136
137 static int tftp_getnextblock(struct tftp_handle *h);
138
139 /* send error message back. */
140 static void
tftp_senderr(struct tftp_handle * h,u_short errcode,const char * msg)141 tftp_senderr(struct tftp_handle *h, u_short errcode, const char *msg)
142 {
143 struct {
144 u_char header[HEADER_SIZE];
145 struct tftphdr t;
146 u_char space[63]; /* +1 from t */
147 } __packed __aligned(4) wbuf;
148 char *wtail;
149 int len;
150
151 len = strlen(msg);
152 if (len > sizeof(wbuf.space))
153 len = sizeof(wbuf.space);
154
155 wbuf.t.th_opcode = htons((u_short) ERROR);
156 wbuf.t.th_code = htons(errcode);
157
158 wtail = wbuf.t.th_msg;
159 bcopy(msg, wtail, len);
160 wtail[len] = '\0';
161 wtail += len + 1;
162
163 sendudp(h->iodesc, &wbuf.t, wtail - (char *) &wbuf.t);
164 }
165
166 static void
tftp_sendack(struct tftp_handle * h)167 tftp_sendack(struct tftp_handle *h)
168 {
169 struct {
170 u_char header[HEADER_SIZE];
171 struct tftphdr t;
172 } __packed __aligned(4) wbuf;
173 char *wtail;
174
175 wbuf.t.th_opcode = htons((u_short) ACK);
176 wtail = (char *) &wbuf.t.th_block;
177 wbuf.t.th_block = htons((u_short) h->currblock);
178 wtail += 2;
179
180 sendudp(h->iodesc, &wbuf.t, wtail - (char *) &wbuf.t);
181 }
182
183 static ssize_t
recvtftp(struct tftp_handle * h,void * pkt,ssize_t len,time_t tleft,unsigned short * rtype)184 recvtftp(struct tftp_handle *h, void *pkt, ssize_t len, time_t tleft,
185 unsigned short *rtype)
186 {
187 struct iodesc *d = h->iodesc;
188 struct tftphdr *t;
189
190 errno = 0;
191
192 len = readudp(d, pkt, len, tleft);
193
194 if (len < 4)
195 return (-1);
196
197 t = (struct tftphdr *) pkt;
198 *rtype = ntohs(t->th_opcode);
199 switch (ntohs(t->th_opcode)) {
200 case DATA: {
201 int got;
202
203 if (htons(t->th_block) != d->xid) {
204 /*
205 * Expected block?
206 */
207 return (-1);
208 }
209 if (d->xid == 1) {
210 /*
211 * First data packet from new port.
212 */
213 struct udphdr *uh;
214 uh = (struct udphdr *) pkt - 1;
215 d->destport = uh->uh_sport;
216 } /* else check uh_sport has not changed??? */
217 got = len - (t->th_data - (char *) t);
218 return got;
219 }
220 case ERROR:
221 if ((unsigned) ntohs(t->th_code) > TFTP_MAX_ERRCODE) {
222 printf("illegal tftp error %d\n", ntohs(t->th_code));
223 errno = EIO;
224 } else {
225 #ifdef TFTP_DEBUG
226 printf("tftp-error %d\n", ntohs(t->th_code));
227 #endif
228 errno = tftperrors[ntohs(t->th_code)];
229 }
230 return (-1);
231 case OACK: {
232 struct udphdr *uh;
233 int tftp_oack_len;
234
235 /*
236 * Unexpected OACK. TFTP transfer already in progress.
237 * Drop the pkt.
238 */
239 if (d->xid != 1) {
240 return (-1);
241 }
242
243 /*
244 * Remember which port this OACK came from, because we need
245 * to send the ACK or errors back to it.
246 */
247 uh = (struct udphdr *) pkt - 1;
248 d->destport = uh->uh_sport;
249
250 /* Parse options ACK-ed by the server. */
251 tftp_oack_len = len - sizeof(t->th_opcode);
252 if (tftp_parse_oack(h, t->th_u.tu_stuff, tftp_oack_len) != 0) {
253 tftp_senderr(h, EOPTNEG, "Malformed OACK");
254 errno = EIO;
255 return (-1);
256 }
257 return (0);
258 }
259 default:
260 #ifdef TFTP_DEBUG
261 printf("tftp type %d not handled\n", ntohs(t->th_opcode));
262 #endif
263 return (-1);
264 }
265 }
266
267 /* send request, expect first block (or error) */
268 static int
tftp_makereq(struct tftp_handle * h)269 tftp_makereq(struct tftp_handle *h)
270 {
271 struct {
272 u_char header[HEADER_SIZE];
273 struct tftphdr t;
274 u_char space[FNAME_SIZE + 6];
275 } __packed __aligned(4) wbuf;
276 char *wtail;
277 int l;
278 ssize_t res;
279 struct tftphdr *t;
280 char *tftp_blksize = NULL;
281 int blksize_l;
282 unsigned short rtype = 0;
283
284 /*
285 * Allow overriding default TFTP block size by setting
286 * a tftp.blksize environment variable.
287 */
288 if ((tftp_blksize = getenv("tftp.blksize")) != NULL) {
289 tftp_set_blksize(h, tftp_blksize);
290 }
291
292 wbuf.t.th_opcode = htons((u_short) RRQ);
293 wtail = wbuf.t.th_stuff;
294 l = strlen(h->path);
295 #ifdef TFTP_PREPEND_PATH
296 if (l > FNAME_SIZE - (sizeof(TFTP_PREPEND_PATH) - 1))
297 return (ENAMETOOLONG);
298 bcopy(TFTP_PREPEND_PATH, wtail, sizeof(TFTP_PREPEND_PATH) - 1);
299 wtail += sizeof(TFTP_PREPEND_PATH) - 1;
300 #else
301 if (l > FNAME_SIZE)
302 return (ENAMETOOLONG);
303 #endif
304 bcopy(h->path, wtail, l + 1);
305 wtail += l + 1;
306 bcopy("octet", wtail, 6);
307 wtail += 6;
308 bcopy("blksize", wtail, 8);
309 wtail += 8;
310 blksize_l = sprintf(wtail, "%d", h->tftp_blksize);
311 wtail += blksize_l + 1;
312 bcopy("tsize", wtail, 6);
313 wtail += 6;
314 bcopy("0", wtail, 2);
315 wtail += 2;
316
317 t = &h->lastdata.t;
318
319 /* h->iodesc->myport = htons(--tftpport); */
320 h->iodesc->myport = htons(tftpport + (getsecs() & 0x3ff));
321 h->iodesc->destport = htons(IPPORT_TFTP);
322 h->iodesc->xid = 1; /* expected block */
323
324 h->currblock = 0;
325 h->islastblock = 0;
326 h->validsize = 0;
327
328 res = sendrecv_tftp(h, &sendudp, &wbuf.t, wtail - (char *) &wbuf.t,
329 &recvtftp, t, sizeof(*t) + h->tftp_blksize, &rtype);
330
331 if (rtype == OACK)
332 return (tftp_getnextblock(h));
333
334 /* Server ignored our blksize request, revert to TFTP default. */
335 h->tftp_blksize = SEGSIZE;
336
337 switch (rtype) {
338 case DATA: {
339 h->currblock = 1;
340 h->validsize = res;
341 h->islastblock = 0;
342 if (res < h->tftp_blksize) {
343 h->islastblock = 1; /* very short file */
344 tftp_sendack(h);
345 }
346 return (0);
347 }
348 case ERROR:
349 default:
350 return (errno);
351 }
352
353 }
354
355 /* ack block, expect next */
356 static int
tftp_getnextblock(struct tftp_handle * h)357 tftp_getnextblock(struct tftp_handle *h)
358 {
359 struct {
360 u_char header[HEADER_SIZE];
361 struct tftphdr t;
362 } __packed __aligned(4) wbuf;
363 char *wtail;
364 int res;
365 struct tftphdr *t;
366 unsigned short rtype = 0;
367 wbuf.t.th_opcode = htons((u_short) ACK);
368 wtail = (char *) &wbuf.t.th_block;
369 wbuf.t.th_block = htons((u_short) h->currblock);
370 wtail += 2;
371
372 t = &h->lastdata.t;
373
374 h->iodesc->xid = h->currblock + 1; /* expected block */
375
376 res = sendrecv_tftp(h, &sendudp, &wbuf.t, wtail - (char *) &wbuf.t,
377 &recvtftp, t, sizeof(*t) + h->tftp_blksize, &rtype);
378
379 if (res == -1) /* 0 is OK! */
380 return (errno);
381
382 h->currblock++;
383 h->validsize = res;
384 if (res < h->tftp_blksize)
385 h->islastblock = 1; /* EOF */
386
387 if (h->islastblock == 1) {
388 /* Send an ACK for the last block */
389 wbuf.t.th_block = htons((u_short) h->currblock);
390 sendudp(h->iodesc, &wbuf.t, wtail - (char *)&wbuf.t);
391 }
392
393 return (0);
394 }
395
396 static int
tftp_open(const char * path,struct open_file * f)397 tftp_open(const char *path, struct open_file *f)
398 {
399 struct tftp_handle *tftpfile;
400 struct iodesc *io;
401 int res;
402 size_t pathsize;
403 const char *extraslash;
404
405 if (strcmp(f->f_dev->dv_name, "net") != 0) {
406 #ifdef __i386__
407 if (strcmp(f->f_dev->dv_name, "pxe") != 0)
408 return (EINVAL);
409 #else
410 return (EINVAL);
411 #endif
412 }
413
414 if (is_open)
415 return (EBUSY);
416
417 tftpfile = (struct tftp_handle *) malloc(sizeof(*tftpfile));
418 if (!tftpfile)
419 return (ENOMEM);
420
421 memset(tftpfile, 0, sizeof(*tftpfile));
422 tftpfile->tftp_blksize = TFTP_REQUESTED_BLKSIZE;
423 tftpfile->iodesc = io = socktodesc(*(int *) (f->f_devdata));
424 if (io == NULL)
425 return (EINVAL);
426
427 io->destip = servip;
428 tftpfile->off = 0;
429 pathsize = (strlen(rootpath) + 1 + strlen(path) + 1) * sizeof(char);
430 tftpfile->path = malloc(pathsize);
431 if (tftpfile->path == NULL) {
432 free(tftpfile);
433 return(ENOMEM);
434 }
435 if (rootpath[strlen(rootpath) - 1] == '/' || path[0] == '/')
436 extraslash = "";
437 else
438 extraslash = "/";
439 res = snprintf(tftpfile->path, pathsize, "%s%s%s",
440 rootpath, extraslash, path);
441 if (res < 0 || res > pathsize) {
442 free(tftpfile->path);
443 free(tftpfile);
444 return(ENOMEM);
445 }
446
447 res = tftp_makereq(tftpfile);
448
449 if (res) {
450 free(tftpfile->path);
451 free(tftpfile);
452 return (res);
453 }
454 f->f_fsdata = (void *) tftpfile;
455 is_open = 1;
456 return (0);
457 }
458
459 static int
tftp_read(struct open_file * f,void * addr,size_t size,size_t * resid)460 tftp_read(struct open_file *f, void *addr, size_t size,
461 size_t *resid /* out */)
462 {
463 struct tftp_handle *tftpfile;
464 tftpfile = (struct tftp_handle *) f->f_fsdata;
465
466 while (size > 0) {
467 int needblock, count;
468
469 twiddle(32);
470
471 needblock = tftpfile->off / tftpfile->tftp_blksize + 1;
472
473 if (tftpfile->currblock > needblock) { /* seek backwards */
474 tftp_senderr(tftpfile, 0, "No error: read aborted");
475 tftp_makereq(tftpfile); /* no error check, it worked
476 * for open */
477 }
478
479 while (tftpfile->currblock < needblock) {
480 int res;
481
482 res = tftp_getnextblock(tftpfile);
483 if (res) { /* no answer */
484 #ifdef TFTP_DEBUG
485 printf("tftp: read error\n");
486 #endif
487 return (res);
488 }
489 if (tftpfile->islastblock)
490 break;
491 }
492
493 if (tftpfile->currblock == needblock) {
494 int offinblock, inbuffer;
495
496 offinblock = tftpfile->off % tftpfile->tftp_blksize;
497
498 inbuffer = tftpfile->validsize - offinblock;
499 if (inbuffer < 0) {
500 #ifdef TFTP_DEBUG
501 printf("tftp: invalid offset %d\n",
502 tftpfile->off);
503 #endif
504 return (EINVAL);
505 }
506 count = (size < inbuffer ? size : inbuffer);
507 bcopy(tftpfile->lastdata.t.th_data + offinblock,
508 addr, count);
509
510 addr = (char *)addr + count;
511 tftpfile->off += count;
512 size -= count;
513
514 if ((tftpfile->islastblock) && (count == inbuffer))
515 break; /* EOF */
516 } else {
517 #ifdef TFTP_DEBUG
518 printf("tftp: block %d not found\n", needblock);
519 #endif
520 return (EINVAL);
521 }
522
523 }
524
525 if (resid)
526 *resid = size;
527 return (0);
528 }
529
530 static int
tftp_close(struct open_file * f)531 tftp_close(struct open_file *f)
532 {
533 struct tftp_handle *tftpfile;
534 tftpfile = (struct tftp_handle *) f->f_fsdata;
535
536 /* let it time out ... */
537
538 if (tftpfile) {
539 free(tftpfile->path);
540 free(tftpfile);
541 }
542 is_open = 0;
543 return (0);
544 }
545
546 static int
tftp_write(struct open_file * f __unused,void * start __unused,size_t size __unused,size_t * resid __unused)547 tftp_write(struct open_file *f __unused, void *start __unused, size_t size __unused,
548 size_t *resid __unused /* out */)
549 {
550 return (EROFS);
551 }
552
553 static int
tftp_stat(struct open_file * f,struct stat * sb)554 tftp_stat(struct open_file *f, struct stat *sb)
555 {
556 struct tftp_handle *tftpfile;
557 tftpfile = (struct tftp_handle *) f->f_fsdata;
558
559 sb->st_mode = 0444 | S_IFREG;
560 sb->st_nlink = 1;
561 sb->st_uid = 0;
562 sb->st_gid = 0;
563 sb->st_size = -1;
564 return (0);
565 }
566
567 static off_t
tftp_seek(struct open_file * f,off_t offset,int where)568 tftp_seek(struct open_file *f, off_t offset, int where)
569 {
570 struct tftp_handle *tftpfile;
571 tftpfile = (struct tftp_handle *) f->f_fsdata;
572
573 switch (where) {
574 case SEEK_SET:
575 tftpfile->off = offset;
576 break;
577 case SEEK_CUR:
578 tftpfile->off += offset;
579 break;
580 default:
581 errno = EOFFSET;
582 return (-1);
583 }
584 return (tftpfile->off);
585 }
586
587 static ssize_t
sendrecv_tftp(struct tftp_handle * h,ssize_t (* sproc)(struct iodesc *,void *,size_t),void * sbuf,size_t ssize,ssize_t (* rproc)(struct tftp_handle *,void *,ssize_t,time_t,unsigned short *),void * rbuf,size_t rsize,unsigned short * rtype)588 sendrecv_tftp(struct tftp_handle *h,
589 ssize_t (*sproc)(struct iodesc *, void *, size_t),
590 void *sbuf, size_t ssize,
591 ssize_t (*rproc)(struct tftp_handle *, void *, ssize_t, time_t, unsigned short *),
592 void *rbuf, size_t rsize, unsigned short *rtype)
593 {
594 struct iodesc *d = h->iodesc;
595 ssize_t cc;
596 time_t t, t1, tleft;
597
598 #ifdef TFTP_DEBUG
599 if (debug)
600 printf("sendrecv: called\n");
601 #endif
602
603 tleft = MINTMO;
604 t = t1 = getsecs();
605 for (;;) {
606 if ((getsecs() - t) > MAXTMO) {
607 errno = ETIMEDOUT;
608 return -1;
609 }
610
611 cc = (*sproc)(d, sbuf, ssize);
612 if (cc != -1 && cc < ssize)
613 panic("sendrecv: short write! (%zd < %zu)",
614 cc, ssize);
615
616 if (cc == -1) {
617 /* Error on transmit; wait before retrying */
618 while ((getsecs() - t1) < tleft);
619 continue;
620 }
621
622 recvnext:
623 /* Try to get a packet and process it. */
624 cc = (*rproc)(h, rbuf, rsize, tleft, rtype);
625 /* Return on data, EOF or real error. */
626 if (cc != -1 || errno != 0)
627 return (cc);
628 if ((getsecs() - t1) < tleft) {
629 goto recvnext;
630 }
631
632 /* Timed out or didn't get the packet we're waiting for */
633 tleft += MINTMO;
634 if (tleft > (2 * MINTMO)) {
635 tleft = (2 * MINTMO);
636 }
637 t1 = getsecs();
638 }
639 }
640
641 static int
tftp_set_blksize(struct tftp_handle * h,const char * str)642 tftp_set_blksize(struct tftp_handle *h, const char *str)
643 {
644 char *endptr;
645 int new_blksize;
646 int ret = 0;
647
648 if (h == NULL || str == NULL)
649 return (ret);
650
651 new_blksize =
652 (unsigned int)strtol(str, &endptr, 0);
653
654 /*
655 * Only accept blksize value if it is numeric.
656 * RFC2348 specifies that acceptable values are 8-65464.
657 * Let's choose a limit less than MAXRSPACE.
658 */
659 if (*endptr == '\0' && new_blksize >= 8
660 && new_blksize <= TFTP_MAX_BLKSIZE) {
661 h->tftp_blksize = new_blksize;
662 ret = 1;
663 }
664
665 return (ret);
666 }
667
668 /*
669 * In RFC2347, the TFTP Option Acknowledgement package (OACK)
670 * is used to acknowledge a client's option negotiation request.
671 * The format of an OACK packet is:
672 * +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+
673 * | opc | opt1 | 0 | value1 | 0 | optN | 0 | valueN | 0 |
674 * +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+
675 *
676 * opc
677 * The opcode field contains a 6, for Option Acknowledgment.
678 *
679 * opt1
680 * The first option acknowledgment, copied from the original
681 * request.
682 *
683 * value1
684 * The acknowledged value associated with the first option. If
685 * and how this value may differ from the original request is
686 * detailed in the specification for the option.
687 *
688 * optN, valueN
689 * The final option/value acknowledgment pair.
690 */
691 static int
tftp_parse_oack(struct tftp_handle * h,char * buf,size_t len)692 tftp_parse_oack(struct tftp_handle *h, char *buf, size_t len)
693 {
694 /*
695 * We parse the OACK strings into an array
696 * of name-value pairs.
697 */
698 char *tftp_options[128] = { 0 };
699 char *val = buf;
700 int i = 0;
701 int option_idx = 0;
702 int blksize_is_set = 0;
703 int tsize = 0;
704
705 unsigned int orig_blksize;
706
707 while (option_idx < 128 && i < len) {
708 if (buf[i] == '\0') {
709 if (&buf[i] > val) {
710 tftp_options[option_idx] = val;
711 val = &buf[i] + 1;
712 ++option_idx;
713 }
714 }
715 ++i;
716 }
717
718 /* Save the block size we requested for sanity check later. */
719 orig_blksize = h->tftp_blksize;
720
721 /*
722 * Parse individual TFTP options.
723 * * "blksize" is specified in RFC2348.
724 * * "tsize" is specified in RFC2349.
725 */
726 for (i = 0; i < option_idx; i += 2) {
727 if (strcasecmp(tftp_options[i], "blksize") == 0) {
728 if (i + 1 < option_idx)
729 blksize_is_set =
730 tftp_set_blksize(h, tftp_options[i + 1]);
731 } else if (strcasecmp(tftp_options[i], "tsize") == 0) {
732 if (i + 1 < option_idx)
733 tsize = strtol(tftp_options[i + 1], (char **)NULL, 10);
734 } else {
735 /* Do not allow any options we did not expect to be ACKed. */
736 printf("unexpected tftp option '%s'\n", tftp_options[i]);
737 return (-1);
738 }
739 }
740
741 if (!blksize_is_set) {
742 /*
743 * If TFTP blksize was not set, try defaulting
744 * to the legacy TFTP blksize of SEGSIZE(512)
745 */
746 h->tftp_blksize = SEGSIZE;
747 } else if (h->tftp_blksize > orig_blksize) {
748 /*
749 * Server should not be proposing block sizes that
750 * exceed what we said we can handle.
751 */
752 printf("unexpected blksize %u\n", h->tftp_blksize);
753 return (-1);
754 }
755
756 #ifdef TFTP_DEBUG
757 printf("tftp_blksize: %u\n", h->tftp_blksize);
758 printf("tftp_tsize: %lu\n", h->tftp_tsize);
759 #endif
760 return 0;
761 }
762