1 /* $NetBSD: tftp.c,v 1.4 1997/09/17 16:57:07 drochner Exp $ */
5 * Matthias Drochner. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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.
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
38 * Simple TFTP implementation for libsa.
40 * - socket descriptor (int) at open_file->f_devdata
41 * - server host IP in global servip
44 * - lseek only with SEEK_SET or SEEK_CUR
45 * - no big time differences between transfers (<tftp timeout)
48 #include <sys/types.h>
50 #include <netinet/in.h>
51 #include <netinet/udp.h>
52 #include <netinet/in_systm.h>
53 #include <arpa/tftp.h>
64 struct tftprecv_extra;
66 static ssize_t recvtftp(struct iodesc *, void **, void **, time_t, void *);
67 static int tftp_open(const char *, struct open_file *);
68 static int tftp_close(struct open_file *);
69 static int tftp_parse_oack(struct tftp_handle *, char *, size_t);
70 static int tftp_read(struct open_file *, void *, size_t, size_t *);
71 static off_t tftp_seek(struct open_file *, off_t, int);
72 static int tftp_set_blksize(struct tftp_handle *, const char *);
73 static int tftp_stat(struct open_file *, struct stat *);
75 struct fs_ops tftp_fsops = {
78 .fo_close = tftp_close,
80 .fo_write = null_write,
83 .fo_readdir = null_readdir
86 extern struct in_addr servip;
88 static int tftpport = 2000;
89 static int is_open = 0;
92 * The legacy TFTP_BLKSIZE value was SEGSIZE(512).
93 * TFTP_REQUESTED_BLKSIZE of 1428 is (Ethernet MTU, less the TFTP, UDP and
96 #define TFTP_REQUESTED_BLKSIZE 1428
99 * Choose a blksize big enough so we can test with Ethernet
100 * Jumbo frames in the future.
102 #define TFTP_MAX_BLKSIZE 9008
106 struct iodesc *iodesc;
107 int currblock; /* contents of lastdata */
108 int islastblock:1; /* flag */
109 int tries:4; /* number of read attempts */
112 char *path; /* saved for re-requests */
113 unsigned int tftp_blksize;
114 unsigned long tftp_tsize;
116 struct tftphdr *tftp_hdr;
119 struct tftprecv_extra {
120 struct tftp_handle *tftp_handle;
121 unsigned short rtype; /* Received type */
124 #define TFTP_MAX_ERRCODE EOPTNEG
125 static const int tftperrors[TFTP_MAX_ERRCODE + 1] = {
134 EINVAL, /* Option negotiation failed. */
137 static int tftp_getnextblock(struct tftp_handle *h);
139 /* send error message back. */
141 tftp_senderr(struct tftp_handle *h, u_short errcode, const char *msg)
144 u_char header[HEADER_SIZE];
146 u_char space[63]; /* +1 from t */
147 } __packed __aligned(4) wbuf;
152 if (len > sizeof(wbuf.space))
153 len = sizeof(wbuf.space);
155 wbuf.t.th_opcode = htons((u_short)ERROR);
156 wbuf.t.th_code = htons(errcode);
158 wtail = wbuf.t.th_msg;
159 bcopy(msg, wtail, len);
163 sendudp(h->iodesc, &wbuf.t, wtail - (char *)&wbuf.t);
167 tftp_sendack(struct tftp_handle *h, u_short block)
170 u_char header[HEADER_SIZE];
172 } __packed __aligned(4) wbuf;
175 wbuf.t.th_opcode = htons((u_short)ACK);
176 wtail = (char *)&wbuf.t.th_block;
177 wbuf.t.th_block = htons(block);
180 sendudp(h->iodesc, &wbuf.t, wtail - (char *)&wbuf.t);
184 recvtftp(struct iodesc *d, void **pkt, void **payload, time_t tleft,
187 struct tftprecv_extra *extra;
188 struct tftp_handle *h;
195 h = extra->tftp_handle;
197 len = readudp(d, &ptr, (void **)&t, tleft);
204 extra->rtype = ntohs(t->th_opcode);
205 switch (ntohs(t->th_opcode)) {
209 if (htons(t->th_block) < (u_short)d->xid) {
211 * Apparently our ACK was missed, re-send.
213 tftp_sendack(h, htons(t->th_block));
217 if (htons(t->th_block) != (u_short)d->xid) {
219 * Packet from the future, drop this.
226 * First data packet from new port.
229 uh = (struct udphdr *)t - 1;
230 d->destport = uh->uh_sport;
232 got = len - (t->th_data - (char *)t);
238 if ((unsigned)ntohs(t->th_code) > TFTP_MAX_ERRCODE) {
239 printf("illegal tftp error %d\n", ntohs(t->th_code));
243 printf("tftp-error %d\n", ntohs(t->th_code));
245 errno = tftperrors[ntohs(t->th_code)];
254 * Unexpected OACK. TFTP transfer already in progress.
263 * Remember which port this OACK came from, because we need
264 * to send the ACK or errors back to it.
266 uh = (struct udphdr *)t - 1;
267 d->destport = uh->uh_sport;
269 /* Parse options ACK-ed by the server. */
270 tftp_oack_len = len - sizeof(t->th_opcode);
271 if (tftp_parse_oack(h, t->th_u.tu_stuff, tftp_oack_len) != 0) {
272 tftp_senderr(h, EOPTNEG, "Malformed OACK");
283 printf("tftp type %d not handled\n", ntohs(t->th_opcode));
290 /* send request, expect first block (or error) */
292 tftp_makereq(struct tftp_handle *h)
295 u_char header[HEADER_SIZE];
297 u_char space[FNAME_SIZE + 6];
298 } __packed __aligned(4) wbuf;
299 struct tftprecv_extra recv_extra;
305 char *tftp_blksize = NULL;
309 * Allow overriding default TFTP block size by setting
310 * a tftp.blksize environment variable.
312 if ((tftp_blksize = getenv("tftp.blksize")) != NULL) {
313 tftp_set_blksize(h, tftp_blksize);
316 wbuf.t.th_opcode = htons((u_short)RRQ);
317 wtail = wbuf.t.th_stuff;
319 #ifdef TFTP_PREPEND_PATH
320 if (l > FNAME_SIZE - (sizeof(TFTP_PREPEND_PATH) - 1))
321 return (ENAMETOOLONG);
322 bcopy(TFTP_PREPEND_PATH, wtail, sizeof(TFTP_PREPEND_PATH) - 1);
323 wtail += sizeof(TFTP_PREPEND_PATH) - 1;
326 return (ENAMETOOLONG);
328 bcopy(h->path, wtail, l + 1);
330 bcopy("octet", wtail, 6);
332 bcopy("blksize", wtail, 8);
334 blksize_l = sprintf(wtail, "%d", h->tftp_blksize);
335 wtail += blksize_l + 1;
336 bcopy("tsize", wtail, 6);
338 bcopy("0", wtail, 2);
341 h->iodesc->myport = htons(tftpport + (getsecs() & 0x3ff));
342 h->iodesc->destport = htons(IPPORT_TFTP);
343 h->iodesc->xid = 1; /* expected block */
350 recv_extra.tftp_handle = h;
351 res = sendrecv(h->iodesc, &sendudp, &wbuf.t, wtail - (char *)&wbuf.t,
352 &recvtftp, &pkt, (void **)&t, &recv_extra);
362 if (recv_extra.rtype == OACK)
363 return (tftp_getnextblock(h));
365 /* Server ignored our blksize request, revert to TFTP default. */
366 h->tftp_blksize = SEGSIZE;
368 switch (recv_extra.rtype) {
373 if (res < h->tftp_blksize) {
374 h->islastblock = 1; /* very short file */
375 tftp_sendack(h, h->currblock);
386 /* ack block, expect next */
388 tftp_getnextblock(struct tftp_handle *h)
391 u_char header[HEADER_SIZE];
393 } __packed __aligned(4) wbuf;
394 struct tftprecv_extra recv_extra;
400 wbuf.t.th_opcode = htons((u_short)ACK);
401 wtail = (char *)&wbuf.t.th_block;
402 wbuf.t.th_block = htons((u_short)h->currblock);
405 h->iodesc->xid = h->currblock + 1; /* expected block */
408 recv_extra.tftp_handle = h;
409 res = sendrecv(h->iodesc, &sendudp, &wbuf.t, wtail - (char *)&wbuf.t,
410 &recvtftp, &pkt, (void **)&t, &recv_extra);
412 if (res == -1) { /* 0 is OK! */
422 if (res < h->tftp_blksize)
423 h->islastblock = 1; /* EOF */
425 if (h->islastblock == 1) {
426 /* Send an ACK for the last block */
427 wbuf.t.th_block = htons((u_short)h->currblock);
428 sendudp(h->iodesc, &wbuf.t, wtail - (char *)&wbuf.t);
435 tftp_open(const char *path, struct open_file *f)
437 struct tftp_handle *tftpfile;
441 const char *extraslash;
443 if (netproto != NET_TFTP)
446 if (f->f_dev->dv_type != DEVT_NET)
452 tftpfile = calloc(1, sizeof(*tftpfile));
456 tftpfile->tftp_blksize = TFTP_REQUESTED_BLKSIZE;
457 tftpfile->iodesc = io = socktodesc(*(int *)(f->f_devdata));
465 pathsize = (strlen(rootpath) + 1 + strlen(path) + 1) * sizeof(char);
466 tftpfile->path = malloc(pathsize);
467 if (tftpfile->path == NULL) {
471 if (rootpath[strlen(rootpath) - 1] == '/' || path[0] == '/')
475 res = snprintf(tftpfile->path, pathsize, "%s%s%s",
476 rootpath, extraslash, path);
477 if (res < 0 || res > pathsize) {
478 free(tftpfile->path);
483 res = tftp_makereq(tftpfile);
486 free(tftpfile->path);
491 f->f_fsdata = tftpfile;
497 tftp_read(struct open_file *f, void *addr, size_t size,
498 size_t *resid /* out */)
500 struct tftp_handle *tftpfile;
506 tftpfile = f->f_fsdata;
508 /* Make sure we will not read past file end */
509 if (tftpfile->tftp_tsize > 0 &&
510 tftpfile->off + size > tftpfile->tftp_tsize) {
511 size = tftpfile->tftp_tsize - tftpfile->off;
515 int needblock, count;
519 needblock = tftpfile->off / tftpfile->tftp_blksize + 1;
521 if (tftpfile->currblock > needblock) { /* seek backwards */
522 tftp_senderr(tftpfile, 0, "No error: read aborted");
523 rc = tftp_makereq(tftpfile);
528 while (tftpfile->currblock < needblock) {
530 rc = tftp_getnextblock(tftpfile);
531 if (rc) { /* no answer */
533 printf("tftp: read error\n");
535 if (tftpfile->tries > TFTP_TRIES) {
539 tftp_makereq(tftpfile);
542 if (tftpfile->islastblock)
546 if (tftpfile->currblock == needblock) {
547 int offinblock, inbuffer;
549 offinblock = tftpfile->off % tftpfile->tftp_blksize;
551 inbuffer = tftpfile->validsize - offinblock;
554 printf("tftp: invalid offset %d\n",
559 count = (size < inbuffer ? size : inbuffer);
560 bcopy(tftpfile->tftp_hdr->th_data + offinblock,
563 addr = (char *)addr + count;
564 tftpfile->off += count;
568 if ((tftpfile->islastblock) && (count == inbuffer))
572 printf("tftp: block %d not found\n", needblock);
585 tftp_close(struct open_file *f)
587 struct tftp_handle *tftpfile;
588 tftpfile = f->f_fsdata;
590 /* let it time out ... */
593 free(tftpfile->path);
602 tftp_stat(struct open_file *f, struct stat *sb)
604 struct tftp_handle *tftpfile;
605 tftpfile = f->f_fsdata;
607 sb->st_mode = 0444 | S_IFREG;
611 sb->st_size = tftpfile->tftp_tsize;
616 tftp_seek(struct open_file *f, off_t offset, int where)
618 struct tftp_handle *tftpfile;
619 tftpfile = f->f_fsdata;
623 tftpfile->off = offset;
626 tftpfile->off += offset;
632 return (tftpfile->off);
636 tftp_set_blksize(struct tftp_handle *h, const char *str)
642 if (h == NULL || str == NULL)
646 (unsigned int)strtol(str, &endptr, 0);
649 * Only accept blksize value if it is numeric.
650 * RFC2348 specifies that acceptable values are 8-65464.
651 * Let's choose a limit less than MAXRSPACE.
653 if (*endptr == '\0' && new_blksize >= 8 &&
654 new_blksize <= TFTP_MAX_BLKSIZE) {
655 h->tftp_blksize = new_blksize;
663 * In RFC2347, the TFTP Option Acknowledgement package (OACK)
664 * is used to acknowledge a client's option negotiation request.
665 * The format of an OACK packet is:
666 * +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+
667 * | opc | opt1 | 0 | value1 | 0 | optN | 0 | valueN | 0 |
668 * +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+
671 * The opcode field contains a 6, for Option Acknowledgment.
674 * The first option acknowledgment, copied from the original
678 * The acknowledged value associated with the first option. If
679 * and how this value may differ from the original request is
680 * detailed in the specification for the option.
683 * The final option/value acknowledgment pair.
686 tftp_parse_oack(struct tftp_handle *h, char *buf, size_t len)
689 * We parse the OACK strings into an array
690 * of name-value pairs.
692 char *tftp_options[128] = { 0 };
696 int blksize_is_set = 0;
699 unsigned int orig_blksize;
701 while (option_idx < 128 && i < len) {
702 if (buf[i] == '\0') {
704 tftp_options[option_idx] = val;
712 /* Save the block size we requested for sanity check later. */
713 orig_blksize = h->tftp_blksize;
716 * Parse individual TFTP options.
717 * * "blksize" is specified in RFC2348.
718 * * "tsize" is specified in RFC2349.
720 for (i = 0; i < option_idx; i += 2) {
721 if (strcasecmp(tftp_options[i], "blksize") == 0) {
722 if (i + 1 < option_idx)
724 tftp_set_blksize(h, tftp_options[i + 1]);
725 } else if (strcasecmp(tftp_options[i], "tsize") == 0) {
726 if (i + 1 < option_idx)
727 tsize = strtol(tftp_options[i + 1], NULL, 10);
729 h->tftp_tsize = tsize;
732 * Do not allow any options we did not expect to be
735 printf("unexpected tftp option '%s'\n",
741 if (!blksize_is_set) {
743 * If TFTP blksize was not set, try defaulting
744 * to the legacy TFTP blksize of SEGSIZE(512)
746 h->tftp_blksize = SEGSIZE;
747 } else if (h->tftp_blksize > orig_blksize) {
749 * Server should not be proposing block sizes that
750 * exceed what we said we can handle.
752 printf("unexpected blksize %u\n", h->tftp_blksize);
757 printf("tftp_blksize: %u\n", h->tftp_blksize);
758 printf("tftp_tsize: %lu\n", h->tftp_tsize);