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
105 struct iodesc *iodesc;
106 int currblock; /* contents of lastdata */
107 int islastblock; /* flag */
110 char *path; /* saved for re-requests */
111 unsigned int tftp_blksize;
112 unsigned long tftp_tsize;
114 struct tftphdr *tftp_hdr;
117 struct tftprecv_extra {
118 struct tftp_handle *tftp_handle;
119 unsigned short rtype; /* Received type */
122 #define TFTP_MAX_ERRCODE EOPTNEG
123 static const int tftperrors[TFTP_MAX_ERRCODE + 1] = {
132 EINVAL, /* Option negotiation failed. */
135 static int tftp_getnextblock(struct tftp_handle *h);
137 /* send error message back. */
139 tftp_senderr(struct tftp_handle *h, u_short errcode, const char *msg)
142 u_char header[HEADER_SIZE];
144 u_char space[63]; /* +1 from t */
145 } __packed __aligned(4) wbuf;
150 if (len > sizeof(wbuf.space))
151 len = sizeof(wbuf.space);
153 wbuf.t.th_opcode = htons((u_short)ERROR);
154 wbuf.t.th_code = htons(errcode);
156 wtail = wbuf.t.th_msg;
157 bcopy(msg, wtail, len);
161 sendudp(h->iodesc, &wbuf.t, wtail - (char *)&wbuf.t);
165 tftp_sendack(struct tftp_handle *h, u_short block)
168 u_char header[HEADER_SIZE];
170 } __packed __aligned(4) wbuf;
173 wbuf.t.th_opcode = htons((u_short)ACK);
174 wtail = (char *)&wbuf.t.th_block;
175 wbuf.t.th_block = htons(block);
178 sendudp(h->iodesc, &wbuf.t, wtail - (char *)&wbuf.t);
182 recvtftp(struct iodesc *d, void **pkt, void **payload, time_t tleft,
185 struct tftprecv_extra *extra;
186 struct tftp_handle *h;
193 h = extra->tftp_handle;
195 len = readudp(d, &ptr, (void **)&t, tleft);
202 extra->rtype = ntohs(t->th_opcode);
203 switch (ntohs(t->th_opcode)) {
207 if (htons(t->th_block) < (u_short)d->xid) {
209 * Apparently our ACK was missed, re-send.
211 tftp_sendack(h, htons(t->th_block));
215 if (htons(t->th_block) != (u_short)d->xid) {
217 * Packet from the future, drop this.
224 * First data packet from new port.
227 uh = (struct udphdr *)t - 1;
228 d->destport = uh->uh_sport;
230 got = len - (t->th_data - (char *)t);
236 if ((unsigned)ntohs(t->th_code) > TFTP_MAX_ERRCODE) {
237 printf("illegal tftp error %d\n", ntohs(t->th_code));
241 printf("tftp-error %d\n", ntohs(t->th_code));
243 errno = tftperrors[ntohs(t->th_code)];
252 * Unexpected OACK. TFTP transfer already in progress.
261 * Remember which port this OACK came from, because we need
262 * to send the ACK or errors back to it.
264 uh = (struct udphdr *)t - 1;
265 d->destport = uh->uh_sport;
267 /* Parse options ACK-ed by the server. */
268 tftp_oack_len = len - sizeof(t->th_opcode);
269 if (tftp_parse_oack(h, t->th_u.tu_stuff, tftp_oack_len) != 0) {
270 tftp_senderr(h, EOPTNEG, "Malformed OACK");
281 printf("tftp type %d not handled\n", ntohs(t->th_opcode));
288 /* send request, expect first block (or error) */
290 tftp_makereq(struct tftp_handle *h)
293 u_char header[HEADER_SIZE];
295 u_char space[FNAME_SIZE + 6];
296 } __packed __aligned(4) wbuf;
297 struct tftprecv_extra recv_extra;
303 char *tftp_blksize = NULL;
307 * Allow overriding default TFTP block size by setting
308 * a tftp.blksize environment variable.
310 if ((tftp_blksize = getenv("tftp.blksize")) != NULL) {
311 tftp_set_blksize(h, tftp_blksize);
314 wbuf.t.th_opcode = htons((u_short)RRQ);
315 wtail = wbuf.t.th_stuff;
317 #ifdef TFTP_PREPEND_PATH
318 if (l > FNAME_SIZE - (sizeof(TFTP_PREPEND_PATH) - 1))
319 return (ENAMETOOLONG);
320 bcopy(TFTP_PREPEND_PATH, wtail, sizeof(TFTP_PREPEND_PATH) - 1);
321 wtail += sizeof(TFTP_PREPEND_PATH) - 1;
324 return (ENAMETOOLONG);
326 bcopy(h->path, wtail, l + 1);
328 bcopy("octet", wtail, 6);
330 bcopy("blksize", wtail, 8);
332 blksize_l = sprintf(wtail, "%d", h->tftp_blksize);
333 wtail += blksize_l + 1;
334 bcopy("tsize", wtail, 6);
336 bcopy("0", wtail, 2);
339 h->iodesc->myport = htons(tftpport + (getsecs() & 0x3ff));
340 h->iodesc->destport = htons(IPPORT_TFTP);
341 h->iodesc->xid = 1; /* expected block */
348 recv_extra.tftp_handle = h;
349 res = sendrecv(h->iodesc, &sendudp, &wbuf.t, wtail - (char *)&wbuf.t,
350 &recvtftp, &pkt, (void **)&t, &recv_extra);
360 if (recv_extra.rtype == OACK)
361 return (tftp_getnextblock(h));
363 /* Server ignored our blksize request, revert to TFTP default. */
364 h->tftp_blksize = SEGSIZE;
366 switch (recv_extra.rtype) {
371 if (res < h->tftp_blksize) {
372 h->islastblock = 1; /* very short file */
373 tftp_sendack(h, h->currblock);
384 /* ack block, expect next */
386 tftp_getnextblock(struct tftp_handle *h)
389 u_char header[HEADER_SIZE];
391 } __packed __aligned(4) wbuf;
392 struct tftprecv_extra recv_extra;
398 wbuf.t.th_opcode = htons((u_short)ACK);
399 wtail = (char *)&wbuf.t.th_block;
400 wbuf.t.th_block = htons((u_short)h->currblock);
403 h->iodesc->xid = h->currblock + 1; /* expected block */
406 recv_extra.tftp_handle = h;
407 res = sendrecv(h->iodesc, &sendudp, &wbuf.t, wtail - (char *)&wbuf.t,
408 &recvtftp, &pkt, (void **)&t, &recv_extra);
410 if (res == -1) { /* 0 is OK! */
420 if (res < h->tftp_blksize)
421 h->islastblock = 1; /* EOF */
423 if (h->islastblock == 1) {
424 /* Send an ACK for the last block */
425 wbuf.t.th_block = htons((u_short)h->currblock);
426 sendudp(h->iodesc, &wbuf.t, wtail - (char *)&wbuf.t);
433 tftp_open(const char *path, struct open_file *f)
435 struct tftp_handle *tftpfile;
439 const char *extraslash;
441 if (netproto != NET_TFTP)
444 if (f->f_dev->dv_type != DEVT_NET)
450 tftpfile = calloc(1, sizeof(*tftpfile));
454 tftpfile->tftp_blksize = TFTP_REQUESTED_BLKSIZE;
455 tftpfile->iodesc = io = socktodesc(*(int *)(f->f_devdata));
463 pathsize = (strlen(rootpath) + 1 + strlen(path) + 1) * sizeof(char);
464 tftpfile->path = malloc(pathsize);
465 if (tftpfile->path == NULL) {
469 if (rootpath[strlen(rootpath) - 1] == '/' || path[0] == '/')
473 res = snprintf(tftpfile->path, pathsize, "%s%s%s",
474 rootpath, extraslash, path);
475 if (res < 0 || res > pathsize) {
476 free(tftpfile->path);
481 res = tftp_makereq(tftpfile);
484 free(tftpfile->path);
489 f->f_fsdata = tftpfile;
495 tftp_read(struct open_file *f, void *addr, size_t size,
496 size_t *resid /* out */)
498 struct tftp_handle *tftpfile;
504 tftpfile = f->f_fsdata;
506 /* Make sure we will not read past file end */
507 if (tftpfile->tftp_tsize > 0 &&
508 tftpfile->off + size > tftpfile->tftp_tsize) {
509 size = tftpfile->tftp_tsize - tftpfile->off;
513 int needblock, count;
517 needblock = tftpfile->off / tftpfile->tftp_blksize + 1;
519 if (tftpfile->currblock > needblock) { /* seek backwards */
520 tftp_senderr(tftpfile, 0, "No error: read aborted");
521 rc = tftp_makereq(tftpfile);
526 while (tftpfile->currblock < needblock) {
528 rc = tftp_getnextblock(tftpfile);
529 if (rc) { /* no answer */
531 printf("tftp: read error\n");
535 if (tftpfile->islastblock)
539 if (tftpfile->currblock == needblock) {
540 int offinblock, inbuffer;
542 offinblock = tftpfile->off % tftpfile->tftp_blksize;
544 inbuffer = tftpfile->validsize - offinblock;
547 printf("tftp: invalid offset %d\n",
552 count = (size < inbuffer ? size : inbuffer);
553 bcopy(tftpfile->tftp_hdr->th_data + offinblock,
556 addr = (char *)addr + count;
557 tftpfile->off += count;
561 if ((tftpfile->islastblock) && (count == inbuffer))
565 printf("tftp: block %d not found\n", needblock);
578 tftp_close(struct open_file *f)
580 struct tftp_handle *tftpfile;
581 tftpfile = f->f_fsdata;
583 /* let it time out ... */
586 free(tftpfile->path);
595 tftp_stat(struct open_file *f, struct stat *sb)
597 struct tftp_handle *tftpfile;
598 tftpfile = f->f_fsdata;
600 sb->st_mode = 0444 | S_IFREG;
604 sb->st_size = tftpfile->tftp_tsize;
609 tftp_seek(struct open_file *f, off_t offset, int where)
611 struct tftp_handle *tftpfile;
612 tftpfile = f->f_fsdata;
616 tftpfile->off = offset;
619 tftpfile->off += offset;
625 return (tftpfile->off);
629 tftp_set_blksize(struct tftp_handle *h, const char *str)
635 if (h == NULL || str == NULL)
639 (unsigned int)strtol(str, &endptr, 0);
642 * Only accept blksize value if it is numeric.
643 * RFC2348 specifies that acceptable values are 8-65464.
644 * Let's choose a limit less than MAXRSPACE.
646 if (*endptr == '\0' && new_blksize >= 8 &&
647 new_blksize <= TFTP_MAX_BLKSIZE) {
648 h->tftp_blksize = new_blksize;
656 * In RFC2347, the TFTP Option Acknowledgement package (OACK)
657 * is used to acknowledge a client's option negotiation request.
658 * The format of an OACK packet is:
659 * +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+
660 * | opc | opt1 | 0 | value1 | 0 | optN | 0 | valueN | 0 |
661 * +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+
664 * The opcode field contains a 6, for Option Acknowledgment.
667 * The first option acknowledgment, copied from the original
671 * The acknowledged value associated with the first option. If
672 * and how this value may differ from the original request is
673 * detailed in the specification for the option.
676 * The final option/value acknowledgment pair.
679 tftp_parse_oack(struct tftp_handle *h, char *buf, size_t len)
682 * We parse the OACK strings into an array
683 * of name-value pairs.
685 char *tftp_options[128] = { 0 };
689 int blksize_is_set = 0;
692 unsigned int orig_blksize;
694 while (option_idx < 128 && i < len) {
695 if (buf[i] == '\0') {
697 tftp_options[option_idx] = val;
705 /* Save the block size we requested for sanity check later. */
706 orig_blksize = h->tftp_blksize;
709 * Parse individual TFTP options.
710 * * "blksize" is specified in RFC2348.
711 * * "tsize" is specified in RFC2349.
713 for (i = 0; i < option_idx; i += 2) {
714 if (strcasecmp(tftp_options[i], "blksize") == 0) {
715 if (i + 1 < option_idx)
717 tftp_set_blksize(h, tftp_options[i + 1]);
718 } else if (strcasecmp(tftp_options[i], "tsize") == 0) {
719 if (i + 1 < option_idx)
720 tsize = strtol(tftp_options[i + 1], NULL, 10);
722 h->tftp_tsize = tsize;
725 * Do not allow any options we did not expect to be
728 printf("unexpected tftp option '%s'\n",
734 if (!blksize_is_set) {
736 * If TFTP blksize was not set, try defaulting
737 * to the legacy TFTP blksize of SEGSIZE(512)
739 h->tftp_blksize = SEGSIZE;
740 } else if (h->tftp_blksize > orig_blksize) {
742 * Server should not be proposing block sizes that
743 * exceed what we said we can handle.
745 printf("unexpected blksize %u\n", h->tftp_blksize);
750 printf("tftp_blksize: %u\n", h->tftp_blksize);
751 printf("tftp_tsize: %lu\n", h->tftp_tsize);