source: MondoRescue/branches/2.2.9/mindi-busybox/networking/tftp.c@ 2725

Last change on this file since 2725 was 2725, checked in by Bruno Cornec, 13 years ago
  • Update mindi-busybox to 1.18.3 to avoid problems with the tar command which is now failing on recent versions with busybox 1.7.3
File size: 22.8 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * A simple tftp client/server for busybox.
4 * Tries to follow RFC1350.
5 * Only "octet" mode supported.
6 * Optional blocksize negotiation (RFC2347 + RFC2348)
7 *
8 * Copyright (C) 2001 Magnus Damm <damm@opensource.se>
9 *
10 * Parts of the code based on:
11 *
12 * atftp: Copyright (C) 2000 Jean-Pierre Lefebvre <helix@step.polymtl.ca>
13 * and Remi Lefebvre <remi@debian.org>
14 *
15 * utftp: Copyright (C) 1999 Uwe Ohse <uwe@ohse.de>
16 *
17 * tftpd added by Denys Vlasenko & Vladimir Dronnikov
18 *
19 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
20 */
21#include "libbb.h"
22
23#if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT
24
25#define TFTP_BLKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */
26#define TFTP_BLKSIZE_DEFAULT_STR "512"
27/* Was 50 ms but users asked to bump it up a bit */
28#define TFTP_TIMEOUT_MS 100
29#define TFTP_MAXTIMEOUT_MS 2000
30#define TFTP_NUM_RETRIES 12 /* number of backed-off retries */
31
32/* opcodes we support */
33#define TFTP_RRQ 1
34#define TFTP_WRQ 2
35#define TFTP_DATA 3
36#define TFTP_ACK 4
37#define TFTP_ERROR 5
38#define TFTP_OACK 6
39
40/* error codes sent over network (we use only 0, 1, 3 and 8) */
41/* generic (error message is included in the packet) */
42#define ERR_UNSPEC 0
43#define ERR_NOFILE 1
44#define ERR_ACCESS 2
45/* disk full or allocation exceeded */
46#define ERR_WRITE 3
47#define ERR_OP 4
48#define ERR_BAD_ID 5
49#define ERR_EXIST 6
50#define ERR_BAD_USER 7
51#define ERR_BAD_OPT 8
52
53/* masks coming from getopt32 */
54enum {
55 TFTP_OPT_GET = (1 << 0),
56 TFTP_OPT_PUT = (1 << 1),
57 /* pseudo option: if set, it's tftpd */
58 TFTPD_OPT = (1 << 7) * ENABLE_TFTPD,
59 TFTPD_OPT_r = (1 << 8) * ENABLE_TFTPD,
60 TFTPD_OPT_c = (1 << 9) * ENABLE_TFTPD,
61 TFTPD_OPT_u = (1 << 10) * ENABLE_TFTPD,
62};
63
64#if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT
65#define IF_GETPUT(...)
66#define CMD_GET(cmd) 1
67#define CMD_PUT(cmd) 0
68#elif !ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT
69#define IF_GETPUT(...)
70#define CMD_GET(cmd) 0
71#define CMD_PUT(cmd) 1
72#else
73#define IF_GETPUT(...) __VA_ARGS__
74#define CMD_GET(cmd) ((cmd) & TFTP_OPT_GET)
75#define CMD_PUT(cmd) ((cmd) & TFTP_OPT_PUT)
76#endif
77/* NB: in the code below
78 * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive
79 */
80
81
82struct globals {
83 /* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */
84 uint8_t error_pkt[4 + 32];
85 char *user_opt;
86 /* used in tftpd_main(), a bit big for stack: */
87 char block_buf[TFTP_BLKSIZE_DEFAULT];
88#if ENABLE_FEATURE_TFTP_PROGRESS_BAR
89 off_t pos;
90 off_t size;
91 const char *file;
92 bb_progress_t pmt;
93#endif
94} FIX_ALIASING;
95#define G (*(struct globals*)&bb_common_bufsiz1)
96struct BUG_G_too_big {
97 char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
98};
99#define block_buf (G.block_buf )
100#define user_opt (G.user_opt )
101#define error_pkt (G.error_pkt )
102#define INIT_G() do { } while (0)
103
104#define error_pkt_reason (error_pkt[3])
105#define error_pkt_str (error_pkt + 4)
106
107#if ENABLE_FEATURE_TFTP_PROGRESS_BAR
108static void tftp_progress_update(void)
109{
110 bb_progress_update(&G.pmt, G.file, 0, G.pos, G.size);
111}
112static void tftp_progress_init(void)
113{
114 bb_progress_init(&G.pmt);
115 tftp_progress_update();
116}
117static void tftp_progress_done(void)
118{
119 if (G.pmt.inited) {
120 tftp_progress_update();
121 bb_putchar_stderr('\n');
122 G.pmt.inited = 0;
123 }
124}
125#else
126# define tftp_progress_init() ((void)0)
127# define tftp_progress_done() ((void)0)
128#endif
129
130#if ENABLE_FEATURE_TFTP_BLOCKSIZE
131
132static int tftp_blksize_check(const char *blksize_str, int maxsize)
133{
134 /* Check if the blksize is valid:
135 * RFC2348 says between 8 and 65464,
136 * but our implementation makes it impossible
137 * to use blksizes smaller than 22 octets. */
138 unsigned blksize = bb_strtou(blksize_str, NULL, 10);
139 if (errno
140 || (blksize < 24) || (blksize > maxsize)
141 ) {
142 bb_error_msg("bad blocksize '%s'", blksize_str);
143 return -1;
144 }
145# if ENABLE_TFTP_DEBUG
146 bb_error_msg("using blksize %u", blksize);
147# endif
148 return blksize;
149}
150
151static char *tftp_get_option(const char *option, char *buf, int len)
152{
153 int opt_val = 0;
154 int opt_found = 0;
155 int k;
156
157 /* buf points to:
158 * "opt_name<NUL>opt_val<NUL>opt_name2<NUL>opt_val2<NUL>..." */
159
160 while (len > 0) {
161 /* Make sure options are terminated correctly */
162 for (k = 0; k < len; k++) {
163 if (buf[k] == '\0') {
164 goto nul_found;
165 }
166 }
167 return NULL;
168 nul_found:
169 if (opt_val == 0) { /* it's "name" part */
170 if (strcasecmp(buf, option) == 0) {
171 opt_found = 1;
172 }
173 } else if (opt_found) {
174 return buf;
175 }
176
177 k++;
178 buf += k;
179 len -= k;
180 opt_val ^= 1;
181 }
182
183 return NULL;
184}
185
186#endif
187
188static int tftp_protocol(
189 /* NULL if tftp, !NULL if tftpd: */
190 len_and_sockaddr *our_lsa,
191 len_and_sockaddr *peer_lsa,
192 const char *local_file
193 IF_TFTP(, const char *remote_file)
194#if !ENABLE_TFTP
195# define remote_file NULL
196#endif
197 /* 1 for tftp; 1/0 for tftpd depending whether client asked about it: */
198 IF_FEATURE_TFTP_BLOCKSIZE(, int want_transfer_size)
199 IF_FEATURE_TFTP_BLOCKSIZE(, int blksize))
200{
201#if !ENABLE_FEATURE_TFTP_BLOCKSIZE
202 enum { blksize = TFTP_BLKSIZE_DEFAULT };
203#endif
204
205 struct pollfd pfd[1];
206#define socket_fd (pfd[0].fd)
207 int len;
208 int send_len;
209 IF_FEATURE_TFTP_BLOCKSIZE(smallint expect_OACK = 0;)
210 smallint finished = 0;
211 uint16_t opcode;
212 uint16_t block_nr;
213 uint16_t recv_blk;
214 int open_mode, local_fd;
215 int retries, waittime_ms;
216 int io_bufsize = blksize + 4;
217 char *cp;
218 /* Can't use RESERVE_CONFIG_BUFFER here since the allocation
219 * size varies meaning BUFFERS_GO_ON_STACK would fail.
220 *
221 * We must keep the transmit and receive buffers separate
222 * in case we rcv a garbage pkt - we need to rexmit the last pkt.
223 */
224 char *xbuf = xmalloc(io_bufsize);
225 char *rbuf = xmalloc(io_bufsize);
226
227 socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0);
228 setsockopt_reuseaddr(socket_fd);
229
230 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
231 /* Create a socket which is:
232 * 1. bound to IP:port peer sent 1st datagram to,
233 * 2. connected to peer's IP:port
234 * This way we will answer from the IP:port peer
235 * expects, will not get any other packets on
236 * the socket, and also plain read/write will work. */
237 xbind(socket_fd, &our_lsa->u.sa, our_lsa->len);
238 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
239
240 /* Is there an error already? Send pkt and bail out */
241 if (error_pkt_reason || error_pkt_str[0])
242 goto send_err_pkt;
243
244 if (user_opt) {
245 struct passwd *pw = xgetpwnam(user_opt);
246 change_identity(pw); /* initgroups, setgid, setuid */
247 }
248 }
249
250 /* Prepare open mode */
251 if (CMD_PUT(option_mask32)) {
252 open_mode = O_RDONLY;
253 } else {
254 open_mode = O_WRONLY | O_TRUNC | O_CREAT;
255#if ENABLE_TFTPD
256 if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) {
257 /* tftpd without -c */
258 open_mode = O_WRONLY | O_TRUNC;
259 }
260#endif
261 }
262
263 /* Examples of network traffic.
264 * Note two cases when ACKs with block# of 0 are sent.
265 *
266 * Download without options:
267 * tftp -> "\0\1FILENAME\0octet\0"
268 * "\0\3\0\1FILEDATA..." <- tftpd
269 * tftp -> "\0\4\0\1"
270 * ...
271 * Download with option of blksize 16384:
272 * tftp -> "\0\1FILENAME\0octet\0blksize\00016384\0"
273 * "\0\6blksize\00016384\0" <- tftpd
274 * tftp -> "\0\4\0\0"
275 * "\0\3\0\1FILEDATA..." <- tftpd
276 * tftp -> "\0\4\0\1"
277 * ...
278 * Upload without options:
279 * tftp -> "\0\2FILENAME\0octet\0"
280 * "\0\4\0\0" <- tftpd
281 * tftp -> "\0\3\0\1FILEDATA..."
282 * "\0\4\0\1" <- tftpd
283 * ...
284 * Upload with option of blksize 16384:
285 * tftp -> "\0\2FILENAME\0octet\0blksize\00016384\0"
286 * "\0\6blksize\00016384\0" <- tftpd
287 * tftp -> "\0\3\0\1FILEDATA..."
288 * "\0\4\0\1" <- tftpd
289 * ...
290 */
291 block_nr = 1;
292 cp = xbuf + 2;
293
294 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
295 /* Open file (must be after changing user) */
296 local_fd = open(local_file, open_mode, 0666);
297 if (local_fd < 0) {
298 error_pkt_reason = ERR_NOFILE;
299 strcpy((char*)error_pkt_str, "can't open file");
300 goto send_err_pkt;
301 }
302/* gcc 4.3.1 would NOT optimize it out as it should! */
303#if ENABLE_FEATURE_TFTP_BLOCKSIZE
304 if (blksize != TFTP_BLKSIZE_DEFAULT || want_transfer_size) {
305 /* Create and send OACK packet. */
306 /* For the download case, block_nr is still 1 -
307 * we expect 1st ACK from peer to be for (block_nr-1),
308 * that is, for "block 0" which is our OACK pkt */
309 opcode = TFTP_OACK;
310 goto add_blksize_opt;
311 }
312#endif
313 if (CMD_GET(option_mask32)) {
314 /* It's upload and we don't send OACK.
315 * We must ACK 1st packet (with filename)
316 * as if it is "block 0" */
317 block_nr = 0;
318 }
319
320 } else { /* tftp */
321 /* Open file (must be after changing user) */
322 local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO;
323 if (NOT_LONE_DASH(local_file))
324 local_fd = xopen(local_file, open_mode);
325/* Removing #if, or using if() statement instead of #if may lead to
326 * "warning: null argument where non-null required": */
327#if ENABLE_TFTP
328 /* tftp */
329
330 /* We can't (and don't really need to) bind the socket:
331 * we don't know from which local IP datagrams will be sent,
332 * but kernel will pick the same IP every time (unless routing
333 * table is changed), thus peer will see dgrams consistently
334 * coming from the same IP.
335 * We would like to connect the socket, but since peer's
336 * UDP code can be less perfect than ours, _peer's_ IP:port
337 * in replies may differ from IP:port we used to send
338 * our first packet. We can connect() only when we get
339 * first reply. */
340
341 /* build opcode */
342 opcode = TFTP_WRQ;
343 if (CMD_GET(option_mask32)) {
344 opcode = TFTP_RRQ;
345 }
346 /* add filename and mode */
347 /* fill in packet if the filename fits into xbuf */
348 len = strlen(remote_file) + 1;
349 if (2 + len + sizeof("octet") >= io_bufsize) {
350 bb_error_msg("remote filename is too long");
351 goto ret;
352 }
353 strcpy(cp, remote_file);
354 cp += len;
355 /* add "mode" part of the packet */
356 strcpy(cp, "octet");
357 cp += sizeof("octet");
358
359# if ENABLE_FEATURE_TFTP_BLOCKSIZE
360 if (blksize == TFTP_BLKSIZE_DEFAULT && !want_transfer_size)
361 goto send_pkt;
362
363 /* Need to add option to pkt */
364 if ((&xbuf[io_bufsize - 1] - cp) < sizeof("blksize NNNNN tsize ") + sizeof(off_t)*3) {
365 bb_error_msg("remote filename is too long");
366 goto ret;
367 }
368 expect_OACK = 1;
369# endif
370#endif /* ENABLE_TFTP */
371
372#if ENABLE_FEATURE_TFTP_BLOCKSIZE
373 add_blksize_opt:
374 if (blksize != TFTP_BLKSIZE_DEFAULT) {
375 /* add "blksize", <nul>, blksize, <nul> */
376 strcpy(cp, "blksize");
377 cp += sizeof("blksize");
378 cp += snprintf(cp, 6, "%d", blksize) + 1;
379 }
380 if (want_transfer_size) {
381 /* add "tsize", <nul>, size, <nul> (see RFC2349) */
382 /* if tftp and downloading, we send "0" (since we opened local_fd with O_TRUNC)
383 * and this makes server to send "tsize" option with the size */
384 /* if tftp and uploading, we send file size (maybe dont, to not confuse old servers???) */
385 /* if tftpd and downloading, we are answering to client's request */
386 /* if tftpd and uploading: !want_transfer_size, this code is not executed */
387 struct stat st;
388 strcpy(cp, "tsize");
389 cp += sizeof("tsize");
390 st.st_size = 0;
391 fstat(local_fd, &st);
392 cp += sprintf(cp, "%"OFF_FMT"u", (off_t)st.st_size) + 1;
393# if ENABLE_FEATURE_TFTP_PROGRESS_BAR
394 /* Save for progress bar. If 0 (tftp downloading),
395 * we look at server's reply later */
396 G.size = st.st_size;
397 if (remote_file && st.st_size)
398 tftp_progress_init();
399# endif
400 }
401#endif
402 /* First packet is built, so skip packet generation */
403 goto send_pkt;
404 }
405
406 /* Using mostly goto's - continue/break will be less clear
407 * in where we actually jump to */
408 while (1) {
409 /* Build ACK or DATA */
410 cp = xbuf + 2;
411 *((uint16_t*)cp) = htons(block_nr);
412 cp += 2;
413 block_nr++;
414 opcode = TFTP_ACK;
415 if (CMD_PUT(option_mask32)) {
416 opcode = TFTP_DATA;
417 len = full_read(local_fd, cp, blksize);
418 if (len < 0) {
419 goto send_read_err_pkt;
420 }
421 if (len != blksize) {
422 finished = 1;
423 }
424 cp += len;
425 }
426 send_pkt:
427 /* Send packet */
428 *((uint16_t*)xbuf) = htons(opcode); /* fill in opcode part */
429 send_len = cp - xbuf;
430 /* NB: send_len value is preserved in code below
431 * for potential resend */
432
433 retries = TFTP_NUM_RETRIES; /* re-initialize */
434 waittime_ms = TFTP_TIMEOUT_MS;
435
436 send_again:
437#if ENABLE_TFTP_DEBUG
438 fprintf(stderr, "sending %u bytes\n", send_len);
439 for (cp = xbuf; cp < &xbuf[send_len]; cp++)
440 fprintf(stderr, "%02x ", (unsigned char) *cp);
441 fprintf(stderr, "\n");
442#endif
443 xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len);
444
445#if ENABLE_FEATURE_TFTP_PROGRESS_BAR
446 if (ENABLE_TFTP && remote_file) /* tftp */
447 G.pos = (block_nr - 1) * (uoff_t)blksize;
448 if (G.pmt.inited)
449 tftp_progress_update();
450#endif
451 /* Was it final ACK? then exit */
452 if (finished && (opcode == TFTP_ACK))
453 goto ret;
454
455 recv_again:
456 /* Receive packet */
457 /*pfd[0].fd = socket_fd;*/
458 pfd[0].events = POLLIN;
459 switch (safe_poll(pfd, 1, waittime_ms)) {
460 default:
461 /*bb_perror_msg("poll"); - done in safe_poll */
462 goto ret;
463 case 0:
464 retries--;
465 if (retries == 0) {
466 tftp_progress_done();
467 bb_error_msg("timeout");
468 goto ret; /* no err packet sent */
469 }
470
471 /* exponential backoff with limit */
472 waittime_ms += waittime_ms/2;
473 if (waittime_ms > TFTP_MAXTIMEOUT_MS) {
474 waittime_ms = TFTP_MAXTIMEOUT_MS;
475 }
476
477 goto send_again; /* resend last sent pkt */
478 case 1:
479 if (!our_lsa) {
480 /* tftp (not tftpd!) receiving 1st packet */
481 our_lsa = ((void*)(ptrdiff_t)-1); /* not NULL */
482 len = recvfrom(socket_fd, rbuf, io_bufsize, 0,
483 &peer_lsa->u.sa, &peer_lsa->len);
484 /* Our first dgram went to port 69
485 * but reply may come from different one.
486 * Remember and use this new port (and IP) */
487 if (len >= 0)
488 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
489 } else {
490 /* tftpd, or not the very first packet:
491 * socket is connect()ed, can just read from it. */
492 /* Don't full_read()!
493 * This is not TCP, one read == one pkt! */
494 len = safe_read(socket_fd, rbuf, io_bufsize);
495 }
496 if (len < 0) {
497 goto send_read_err_pkt;
498 }
499 if (len < 4) { /* too small? */
500 goto recv_again;
501 }
502 }
503
504 /* Process recv'ed packet */
505 opcode = ntohs( ((uint16_t*)rbuf)[0] );
506 recv_blk = ntohs( ((uint16_t*)rbuf)[1] );
507#if ENABLE_TFTP_DEBUG
508 fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk);
509#endif
510 if (opcode == TFTP_ERROR) {
511 static const char errcode_str[] ALIGN1 =
512 "\0"
513 "file not found\0"
514 "access violation\0"
515 "disk full\0"
516 "bad operation\0"
517 "unknown transfer id\0"
518 "file already exists\0"
519 "no such user\0"
520 "bad option";
521
522 const char *msg = "";
523
524 if (len > 4 && rbuf[4] != '\0') {
525 msg = &rbuf[4];
526 rbuf[io_bufsize - 1] = '\0'; /* paranoia */
527 } else if (recv_blk <= 8) {
528 msg = nth_string(errcode_str, recv_blk);
529 }
530 bb_error_msg("server error: (%u) %s", recv_blk, msg);
531 goto ret;
532 }
533
534#if ENABLE_FEATURE_TFTP_BLOCKSIZE
535 if (expect_OACK) {
536 expect_OACK = 0;
537 if (opcode == TFTP_OACK) {
538 /* server seems to support options */
539 char *res;
540
541 res = tftp_get_option("blksize", &rbuf[2], len - 2);
542 if (res) {
543 blksize = tftp_blksize_check(res, blksize);
544 if (blksize < 0) {
545 error_pkt_reason = ERR_BAD_OPT;
546 goto send_err_pkt;
547 }
548 io_bufsize = blksize + 4;
549 }
550# if ENABLE_FEATURE_TFTP_PROGRESS_BAR
551 if (remote_file && G.size == 0) { /* if we don't know it yet */
552 res = tftp_get_option("tsize", &rbuf[2], len - 2);
553 if (res) {
554 G.size = bb_strtoull(res, NULL, 10);
555 if (G.size)
556 tftp_progress_init();
557 }
558 }
559# endif
560 if (CMD_GET(option_mask32)) {
561 /* We'll send ACK for OACK,
562 * such ACK has "block no" of 0 */
563 block_nr = 0;
564 }
565 continue;
566 }
567 /* rfc2347:
568 * "An option not acknowledged by the server
569 * must be ignored by the client and server
570 * as if it were never requested." */
571 if (blksize != TFTP_BLKSIZE_DEFAULT)
572 bb_error_msg("falling back to blocksize "TFTP_BLKSIZE_DEFAULT_STR);
573 blksize = TFTP_BLKSIZE_DEFAULT;
574 io_bufsize = TFTP_BLKSIZE_DEFAULT + 4;
575 }
576#endif
577 /* block_nr is already advanced to next block# we expect
578 * to get / block# we are about to send next time */
579
580 if (CMD_GET(option_mask32) && (opcode == TFTP_DATA)) {
581 if (recv_blk == block_nr) {
582 int sz = full_write(local_fd, &rbuf[4], len - 4);
583 if (sz != len - 4) {
584 strcpy((char*)error_pkt_str, bb_msg_write_error);
585 error_pkt_reason = ERR_WRITE;
586 goto send_err_pkt;
587 }
588 if (sz != blksize) {
589 finished = 1;
590 }
591 continue; /* send ACK */
592 }
593/* Disabled to cope with servers with Sorcerer's Apprentice Syndrome */
594#if 0
595 if (recv_blk == (block_nr - 1)) {
596 /* Server lost our TFTP_ACK. Resend it */
597 block_nr = recv_blk;
598 continue;
599 }
600#endif
601 }
602
603 if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) {
604 /* did peer ACK our last DATA pkt? */
605 if (recv_blk == (uint16_t) (block_nr - 1)) {
606 if (finished)
607 goto ret;
608 continue; /* send next block */
609 }
610 }
611 /* Awww... recv'd packet is not recognized! */
612 goto recv_again;
613 /* why recv_again? - rfc1123 says:
614 * "The sender (i.e., the side originating the DATA packets)
615 * must never resend the current DATA packet on receipt
616 * of a duplicate ACK".
617 * DATA pkts are resent ONLY on timeout.
618 * Thus "goto send_again" will ba a bad mistake above.
619 * See:
620 * http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome
621 */
622 } /* end of "while (1)" */
623 ret:
624 if (ENABLE_FEATURE_CLEAN_UP) {
625 close(local_fd);
626 close(socket_fd);
627 free(xbuf);
628 free(rbuf);
629 }
630 return finished == 0; /* returns 1 on failure */
631
632 send_read_err_pkt:
633 strcpy((char*)error_pkt_str, bb_msg_read_error);
634 send_err_pkt:
635 if (error_pkt_str[0])
636 bb_error_msg("%s", (char*)error_pkt_str);
637 error_pkt[1] = TFTP_ERROR;
638 xsendto(socket_fd, error_pkt, 4 + 1 + strlen((char*)error_pkt_str),
639 &peer_lsa->u.sa, peer_lsa->len);
640 return EXIT_FAILURE;
641#undef remote_file
642}
643
644#if ENABLE_TFTP
645
646int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
647int tftp_main(int argc UNUSED_PARAM, char **argv)
648{
649 len_and_sockaddr *peer_lsa;
650 const char *local_file = NULL;
651 const char *remote_file = NULL;
652# if ENABLE_FEATURE_TFTP_BLOCKSIZE
653 const char *blksize_str = TFTP_BLKSIZE_DEFAULT_STR;
654 int blksize;
655# endif
656 int result;
657 int port;
658 IF_GETPUT(int opt;)
659
660 INIT_G();
661
662 /* -p or -g is mandatory, and they are mutually exclusive */
663 opt_complementary = "" IF_FEATURE_TFTP_GET("g:") IF_FEATURE_TFTP_PUT("p:")
664 IF_GETPUT("g--p:p--g:");
665
666 IF_GETPUT(opt =) getopt32(argv,
667 IF_FEATURE_TFTP_GET("g") IF_FEATURE_TFTP_PUT("p")
668 "l:r:" IF_FEATURE_TFTP_BLOCKSIZE("b:"),
669 &local_file, &remote_file
670 IF_FEATURE_TFTP_BLOCKSIZE(, &blksize_str));
671 argv += optind;
672
673# if ENABLE_FEATURE_TFTP_BLOCKSIZE
674 /* Check if the blksize is valid:
675 * RFC2348 says between 8 and 65464 */
676 blksize = tftp_blksize_check(blksize_str, 65564);
677 if (blksize < 0) {
678 //bb_error_msg("bad block size");
679 return EXIT_FAILURE;
680 }
681# endif
682
683 if (remote_file) {
684 if (!local_file) {
685 const char *slash = strrchr(remote_file, '/');
686 local_file = slash ? slash + 1 : remote_file;
687 }
688 } else {
689 remote_file = local_file;
690 }
691
692 /* Error if filename or host is not known */
693 if (!remote_file || !argv[0])
694 bb_show_usage();
695
696 port = bb_lookup_port(argv[1], "udp", 69);
697 peer_lsa = xhost2sockaddr(argv[0], port);
698
699# if ENABLE_TFTP_DEBUG
700 fprintf(stderr, "using server '%s', remote_file '%s', local_file '%s'\n",
701 xmalloc_sockaddr2dotted(&peer_lsa->u.sa),
702 remote_file, local_file);
703# endif
704
705# if ENABLE_FEATURE_TFTP_PROGRESS_BAR
706 G.file = remote_file;
707# endif
708 result = tftp_protocol(
709 NULL /*our_lsa*/, peer_lsa,
710 local_file, remote_file
711 IF_FEATURE_TFTP_BLOCKSIZE(, 1 /* want_transfer_size */)
712 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
713 );
714 tftp_progress_done();
715
716 if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) {
717 unlink(local_file);
718 }
719 return result;
720}
721
722#endif /* ENABLE_TFTP */
723
724#if ENABLE_TFTPD
725int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
726int tftpd_main(int argc UNUSED_PARAM, char **argv)
727{
728 len_and_sockaddr *our_lsa;
729 len_and_sockaddr *peer_lsa;
730 char *local_file, *mode;
731 const char *error_msg;
732 int opt, result, opcode;
733 IF_FEATURE_TFTP_BLOCKSIZE(int blksize = TFTP_BLKSIZE_DEFAULT;)
734 IF_FEATURE_TFTP_BLOCKSIZE(int want_transfer_size = 0;)
735
736 INIT_G();
737
738 our_lsa = get_sock_lsa(STDIN_FILENO);
739 if (!our_lsa) {
740 /* This is confusing:
741 *bb_error_msg_and_die("stdin is not a socket");
742 * Better: */
743 bb_show_usage();
744 /* Help text says that tftpd must be used as inetd service,
745 * which is by far the most usual cause of get_sock_lsa
746 * failure */
747 }
748 peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len);
749 peer_lsa->len = our_lsa->len;
750
751 /* Shifting to not collide with TFTP_OPTs */
752 opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:", &user_opt) << 8);
753 argv += optind;
754 if (argv[0])
755 xchdir(argv[0]);
756
757 result = recv_from_to(STDIN_FILENO, block_buf, sizeof(block_buf),
758 0 /* flags */,
759 &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len);
760
761 error_msg = "malformed packet";
762 opcode = ntohs(*(uint16_t*)block_buf);
763 if (result < 4 || result >= sizeof(block_buf)
764 || block_buf[result-1] != '\0'
765 || (IF_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */
766 IF_GETPUT(&&)
767 IF_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */
768 )
769 ) {
770 goto err;
771 }
772 local_file = block_buf + 2;
773 if (local_file[0] == '.' || strstr(local_file, "/.")) {
774 error_msg = "dot in file name";
775 goto err;
776 }
777 mode = local_file + strlen(local_file) + 1;
778 if (mode >= block_buf + result || strcmp(mode, "octet") != 0) {
779 goto err;
780 }
781# if ENABLE_FEATURE_TFTP_BLOCKSIZE
782 {
783 char *res;
784 char *opt_str = mode + sizeof("octet");
785 int opt_len = block_buf + result - opt_str;
786 if (opt_len > 0) {
787 res = tftp_get_option("blksize", opt_str, opt_len);
788 if (res) {
789 blksize = tftp_blksize_check(res, 65564);
790 if (blksize < 0) {
791 error_pkt_reason = ERR_BAD_OPT;
792 /* will just send error pkt */
793 goto do_proto;
794 }
795 }
796 if (opcode != TFTP_WRQ /* download? */
797 /* did client ask us about file size? */
798 && tftp_get_option("tsize", opt_str, opt_len)
799 ) {
800 want_transfer_size = 1;
801 }
802 }
803 }
804# endif
805
806 if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) {
807 if (opt & TFTPD_OPT_r) {
808 /* This would mean "disk full" - not true */
809 /*error_pkt_reason = ERR_WRITE;*/
810 error_msg = bb_msg_write_error;
811 goto err;
812 }
813 IF_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */
814 } else {
815 IF_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */
816 }
817
818 /* NB: if error_pkt_str or error_pkt_reason is set up,
819 * tftp_protocol() just sends one error pkt and returns */
820
821 do_proto:
822 close(STDIN_FILENO); /* close old, possibly wildcard socket */
823 /* tftp_protocol() will create new one, bound to particular local IP */
824 result = tftp_protocol(
825 our_lsa, peer_lsa,
826 local_file IF_TFTP(, NULL /*remote_file*/)
827 IF_FEATURE_TFTP_BLOCKSIZE(, want_transfer_size)
828 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
829 );
830
831 return result;
832 err:
833 strcpy((char*)error_pkt_str, error_msg);
834 goto do_proto;
835}
836
837#endif /* ENABLE_TFTPD */
838
839#endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */
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