source: MondoRescue/branches/3.2/mindi-busybox/networking/tftp.c@ 3232

Last change on this file since 3232 was 3232, checked in by Bruno Cornec, 10 years ago
  • Update mindi-busybox to 1.21.1
File size: 24.2 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
22//usage:#define tftp_trivial_usage
23//usage: "[OPTIONS] HOST [PORT]"
24//usage:#define tftp_full_usage "\n\n"
25//usage: "Transfer a file from/to tftp server\n"
26//usage: "\n -l FILE Local FILE"
27//usage: "\n -r FILE Remote FILE"
28//usage: IF_FEATURE_TFTP_GET(
29//usage: "\n -g Get file"
30//usage: )
31//usage: IF_FEATURE_TFTP_PUT(
32//usage: "\n -p Put file"
33//usage: )
34//usage: IF_FEATURE_TFTP_BLOCKSIZE(
35//usage: "\n -b SIZE Transfer blocks of SIZE octets"
36//usage: )
37//usage:
38//usage:#define tftpd_trivial_usage
39//usage: "[-cr] [-u USER] [DIR]"
40//usage:#define tftpd_full_usage "\n\n"
41//usage: "Transfer a file on tftp client's request\n"
42//usage: "\n"
43//usage: "tftpd should be used as an inetd service.\n"
44//usage: "tftpd's line for inetd.conf:\n"
45//usage: " 69 dgram udp nowait root tftpd tftpd -l /files/to/serve\n"
46//usage: "It also can be ran from udpsvd:\n"
47//usage: " udpsvd -vE 0.0.0.0 69 tftpd /files/to/serve\n"
48//usage: "\n -r Prohibit upload"
49//usage: "\n -c Allow file creation via upload"
50//usage: "\n -u Access files as USER"
51//usage: "\n -l Log to syslog (inetd mode requires this)"
52
53#include "libbb.h"
54#include <syslog.h>
55
56#if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT
57
58#define TFTP_BLKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */
59#define TFTP_BLKSIZE_DEFAULT_STR "512"
60/* Was 50 ms but users asked to bump it up a bit */
61#define TFTP_TIMEOUT_MS 100
62#define TFTP_MAXTIMEOUT_MS 2000
63#define TFTP_NUM_RETRIES 12 /* number of backed-off retries */
64
65/* opcodes we support */
66#define TFTP_RRQ 1
67#define TFTP_WRQ 2
68#define TFTP_DATA 3
69#define TFTP_ACK 4
70#define TFTP_ERROR 5
71#define TFTP_OACK 6
72
73/* error codes sent over network (we use only 0, 1, 3 and 8) */
74/* generic (error message is included in the packet) */
75#define ERR_UNSPEC 0
76#define ERR_NOFILE 1
77#define ERR_ACCESS 2
78/* disk full or allocation exceeded */
79#define ERR_WRITE 3
80#define ERR_OP 4
81#define ERR_BAD_ID 5
82#define ERR_EXIST 6
83#define ERR_BAD_USER 7
84#define ERR_BAD_OPT 8
85
86/* masks coming from getopt32 */
87enum {
88 TFTP_OPT_GET = (1 << 0),
89 TFTP_OPT_PUT = (1 << 1),
90 /* pseudo option: if set, it's tftpd */
91 TFTPD_OPT = (1 << 7) * ENABLE_TFTPD,
92 TFTPD_OPT_r = (1 << 8) * ENABLE_TFTPD,
93 TFTPD_OPT_c = (1 << 9) * ENABLE_TFTPD,
94 TFTPD_OPT_u = (1 << 10) * ENABLE_TFTPD,
95 TFTPD_OPT_l = (1 << 11) * ENABLE_TFTPD,
96};
97
98#if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT
99#define IF_GETPUT(...)
100#define CMD_GET(cmd) 1
101#define CMD_PUT(cmd) 0
102#elif !ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT
103#define IF_GETPUT(...)
104#define CMD_GET(cmd) 0
105#define CMD_PUT(cmd) 1
106#else
107#define IF_GETPUT(...) __VA_ARGS__
108#define CMD_GET(cmd) ((cmd) & TFTP_OPT_GET)
109#define CMD_PUT(cmd) ((cmd) & TFTP_OPT_PUT)
110#endif
111/* NB: in the code below
112 * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive
113 */
114
115
116struct globals {
117 /* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */
118 uint8_t error_pkt[4 + 32];
119 struct passwd *pw;
120 /* used in tftpd_main(), a bit big for stack: */
121 char block_buf[TFTP_BLKSIZE_DEFAULT];
122#if ENABLE_FEATURE_TFTP_PROGRESS_BAR
123 off_t pos;
124 off_t size;
125 const char *file;
126 bb_progress_t pmt;
127#endif
128} FIX_ALIASING;
129#define G (*(struct globals*)&bb_common_bufsiz1)
130struct BUG_G_too_big {
131 char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
132};
133#define INIT_G() do { } while (0)
134
135#define G_error_pkt_reason (G.error_pkt[3])
136#define G_error_pkt_str ((char*)(G.error_pkt + 4))
137
138#if ENABLE_FEATURE_TFTP_PROGRESS_BAR
139static void tftp_progress_update(void)
140{
141 bb_progress_update(&G.pmt, 0, G.pos, G.size);
142}
143static void tftp_progress_init(void)
144{
145 bb_progress_init(&G.pmt, G.file);
146 tftp_progress_update();
147}
148static void tftp_progress_done(void)
149{
150 if (is_bb_progress_inited(&G.pmt)) {
151 tftp_progress_update();
152 bb_putchar_stderr('\n');
153 bb_progress_free(&G.pmt);
154 }
155}
156#else
157# define tftp_progress_init() ((void)0)
158# define tftp_progress_done() ((void)0)
159#endif
160
161#if ENABLE_FEATURE_TFTP_BLOCKSIZE
162
163static int tftp_blksize_check(const char *blksize_str, int maxsize)
164{
165 /* Check if the blksize is valid:
166 * RFC2348 says between 8 and 65464,
167 * but our implementation makes it impossible
168 * to use blksizes smaller than 22 octets. */
169 unsigned blksize = bb_strtou(blksize_str, NULL, 10);
170 if (errno
171 || (blksize < 24) || (blksize > maxsize)
172 ) {
173 bb_error_msg("bad blocksize '%s'", blksize_str);
174 return -1;
175 }
176# if ENABLE_TFTP_DEBUG
177 bb_error_msg("using blksize %u", blksize);
178# endif
179 return blksize;
180}
181
182static char *tftp_get_option(const char *option, char *buf, int len)
183{
184 int opt_val = 0;
185 int opt_found = 0;
186 int k;
187
188 /* buf points to:
189 * "opt_name<NUL>opt_val<NUL>opt_name2<NUL>opt_val2<NUL>..." */
190
191 while (len > 0) {
192 /* Make sure options are terminated correctly */
193 for (k = 0; k < len; k++) {
194 if (buf[k] == '\0') {
195 goto nul_found;
196 }
197 }
198 return NULL;
199 nul_found:
200 if (opt_val == 0) { /* it's "name" part */
201 if (strcasecmp(buf, option) == 0) {
202 opt_found = 1;
203 }
204 } else if (opt_found) {
205 return buf;
206 }
207
208 k++;
209 buf += k;
210 len -= k;
211 opt_val ^= 1;
212 }
213
214 return NULL;
215}
216
217#endif
218
219static int tftp_protocol(
220 /* NULL if tftp, !NULL if tftpd: */
221 len_and_sockaddr *our_lsa,
222 len_and_sockaddr *peer_lsa,
223 const char *local_file
224 IF_TFTP(, const char *remote_file)
225#if !ENABLE_TFTP
226# define remote_file NULL
227#endif
228 /* 1 for tftp; 1/0 for tftpd depending whether client asked about it: */
229 IF_FEATURE_TFTP_BLOCKSIZE(, int want_transfer_size)
230 IF_FEATURE_TFTP_BLOCKSIZE(, int blksize))
231{
232#if !ENABLE_FEATURE_TFTP_BLOCKSIZE
233 enum { blksize = TFTP_BLKSIZE_DEFAULT };
234#endif
235
236 struct pollfd pfd[1];
237#define socket_fd (pfd[0].fd)
238 int len;
239 int send_len;
240 IF_FEATURE_TFTP_BLOCKSIZE(smallint expect_OACK = 0;)
241 smallint finished = 0;
242 uint16_t opcode;
243 uint16_t block_nr;
244 uint16_t recv_blk;
245 int open_mode, local_fd;
246 int retries, waittime_ms;
247 int io_bufsize = blksize + 4;
248 char *cp;
249 /* Can't use RESERVE_CONFIG_BUFFER here since the allocation
250 * size varies meaning BUFFERS_GO_ON_STACK would fail.
251 *
252 * We must keep the transmit and receive buffers separate
253 * in case we rcv a garbage pkt - we need to rexmit the last pkt.
254 */
255 char *xbuf = xmalloc(io_bufsize);
256 char *rbuf = xmalloc(io_bufsize);
257
258 socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0);
259 setsockopt_reuseaddr(socket_fd);
260
261 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
262 /* Create a socket which is:
263 * 1. bound to IP:port peer sent 1st datagram to,
264 * 2. connected to peer's IP:port
265 * This way we will answer from the IP:port peer
266 * expects, will not get any other packets on
267 * the socket, and also plain read/write will work. */
268 xbind(socket_fd, &our_lsa->u.sa, our_lsa->len);
269 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
270
271 /* Is there an error already? Send pkt and bail out */
272 if (G_error_pkt_reason || G_error_pkt_str[0])
273 goto send_err_pkt;
274
275 if (G.pw) {
276 change_identity(G.pw); /* initgroups, setgid, setuid */
277 }
278 }
279
280 /* Prepare open mode */
281 if (CMD_PUT(option_mask32)) {
282 open_mode = O_RDONLY;
283 } else {
284 open_mode = O_WRONLY | O_TRUNC | O_CREAT;
285#if ENABLE_TFTPD
286 if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) {
287 /* tftpd without -c */
288 open_mode = O_WRONLY | O_TRUNC;
289 }
290#endif
291 }
292
293 /* Examples of network traffic.
294 * Note two cases when ACKs with block# of 0 are sent.
295 *
296 * Download without options:
297 * tftp -> "\0\1FILENAME\0octet\0"
298 * "\0\3\0\1FILEDATA..." <- tftpd
299 * tftp -> "\0\4\0\1"
300 * ...
301 * Download with option of blksize 16384:
302 * tftp -> "\0\1FILENAME\0octet\0blksize\00016384\0"
303 * "\0\6blksize\00016384\0" <- tftpd
304 * tftp -> "\0\4\0\0"
305 * "\0\3\0\1FILEDATA..." <- tftpd
306 * tftp -> "\0\4\0\1"
307 * ...
308 * Upload without options:
309 * tftp -> "\0\2FILENAME\0octet\0"
310 * "\0\4\0\0" <- tftpd
311 * tftp -> "\0\3\0\1FILEDATA..."
312 * "\0\4\0\1" <- tftpd
313 * ...
314 * Upload with option of blksize 16384:
315 * tftp -> "\0\2FILENAME\0octet\0blksize\00016384\0"
316 * "\0\6blksize\00016384\0" <- tftpd
317 * tftp -> "\0\3\0\1FILEDATA..."
318 * "\0\4\0\1" <- tftpd
319 * ...
320 */
321 block_nr = 1;
322 cp = xbuf + 2;
323
324 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
325 /* Open file (must be after changing user) */
326 local_fd = open(local_file, open_mode, 0666);
327 if (local_fd < 0) {
328 G_error_pkt_reason = ERR_NOFILE;
329 strcpy(G_error_pkt_str, "can't open file");
330 goto send_err_pkt;
331 }
332/* gcc 4.3.1 would NOT optimize it out as it should! */
333#if ENABLE_FEATURE_TFTP_BLOCKSIZE
334 if (blksize != TFTP_BLKSIZE_DEFAULT || want_transfer_size) {
335 /* Create and send OACK packet. */
336 /* For the download case, block_nr is still 1 -
337 * we expect 1st ACK from peer to be for (block_nr-1),
338 * that is, for "block 0" which is our OACK pkt */
339 opcode = TFTP_OACK;
340 goto add_blksize_opt;
341 }
342#endif
343 if (CMD_GET(option_mask32)) {
344 /* It's upload and we don't send OACK.
345 * We must ACK 1st packet (with filename)
346 * as if it is "block 0" */
347 block_nr = 0;
348 }
349
350 } else { /* tftp */
351 /* Open file (must be after changing user) */
352 local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO;
353 if (NOT_LONE_DASH(local_file))
354 local_fd = xopen(local_file, open_mode);
355/* Removing #if, or using if() statement instead of #if may lead to
356 * "warning: null argument where non-null required": */
357#if ENABLE_TFTP
358 /* tftp */
359
360 /* We can't (and don't really need to) bind the socket:
361 * we don't know from which local IP datagrams will be sent,
362 * but kernel will pick the same IP every time (unless routing
363 * table is changed), thus peer will see dgrams consistently
364 * coming from the same IP.
365 * We would like to connect the socket, but since peer's
366 * UDP code can be less perfect than ours, _peer's_ IP:port
367 * in replies may differ from IP:port we used to send
368 * our first packet. We can connect() only when we get
369 * first reply. */
370
371 /* build opcode */
372 opcode = TFTP_WRQ;
373 if (CMD_GET(option_mask32)) {
374 opcode = TFTP_RRQ;
375 }
376 /* add filename and mode */
377 /* fill in packet if the filename fits into xbuf */
378 len = strlen(remote_file) + 1;
379 if (2 + len + sizeof("octet") >= io_bufsize) {
380 bb_error_msg("remote filename is too long");
381 goto ret;
382 }
383 strcpy(cp, remote_file);
384 cp += len;
385 /* add "mode" part of the packet */
386 strcpy(cp, "octet");
387 cp += sizeof("octet");
388
389# if ENABLE_FEATURE_TFTP_BLOCKSIZE
390 if (blksize == TFTP_BLKSIZE_DEFAULT && !want_transfer_size)
391 goto send_pkt;
392
393 /* Need to add option to pkt */
394 if ((&xbuf[io_bufsize - 1] - cp) < sizeof("blksize NNNNN tsize ") + sizeof(off_t)*3) {
395 bb_error_msg("remote filename is too long");
396 goto ret;
397 }
398 expect_OACK = 1;
399# endif
400#endif /* ENABLE_TFTP */
401
402#if ENABLE_FEATURE_TFTP_BLOCKSIZE
403 add_blksize_opt:
404 if (blksize != TFTP_BLKSIZE_DEFAULT) {
405 /* add "blksize", <nul>, blksize, <nul> */
406 strcpy(cp, "blksize");
407 cp += sizeof("blksize");
408 cp += snprintf(cp, 6, "%d", blksize) + 1;
409 }
410 if (want_transfer_size) {
411 /* add "tsize", <nul>, size, <nul> (see RFC2349) */
412 /* if tftp and downloading, we send "0" (since we opened local_fd with O_TRUNC)
413 * and this makes server to send "tsize" option with the size */
414 /* if tftp and uploading, we send file size (maybe dont, to not confuse old servers???) */
415 /* if tftpd and downloading, we are answering to client's request */
416 /* if tftpd and uploading: !want_transfer_size, this code is not executed */
417 struct stat st;
418 strcpy(cp, "tsize");
419 cp += sizeof("tsize");
420 st.st_size = 0;
421 fstat(local_fd, &st);
422 cp += sprintf(cp, "%"OFF_FMT"u", (off_t)st.st_size) + 1;
423# if ENABLE_FEATURE_TFTP_PROGRESS_BAR
424 /* Save for progress bar. If 0 (tftp downloading),
425 * we look at server's reply later */
426 G.size = st.st_size;
427 if (remote_file && st.st_size)
428 tftp_progress_init();
429# endif
430 }
431#endif
432 /* First packet is built, so skip packet generation */
433 goto send_pkt;
434 }
435
436 /* Using mostly goto's - continue/break will be less clear
437 * in where we actually jump to */
438 while (1) {
439 /* Build ACK or DATA */
440 cp = xbuf + 2;
441 *((uint16_t*)cp) = htons(block_nr);
442 cp += 2;
443 block_nr++;
444 opcode = TFTP_ACK;
445 if (CMD_PUT(option_mask32)) {
446 opcode = TFTP_DATA;
447 len = full_read(local_fd, cp, blksize);
448 if (len < 0) {
449 goto send_read_err_pkt;
450 }
451 if (len != blksize) {
452 finished = 1;
453 }
454 cp += len;
455 IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += len;)
456 }
457 send_pkt:
458 /* Send packet */
459 *((uint16_t*)xbuf) = htons(opcode); /* fill in opcode part */
460 send_len = cp - xbuf;
461 /* NB: send_len value is preserved in code below
462 * for potential resend */
463
464 retries = TFTP_NUM_RETRIES; /* re-initialize */
465 waittime_ms = TFTP_TIMEOUT_MS;
466
467 send_again:
468#if ENABLE_TFTP_DEBUG
469 fprintf(stderr, "sending %u bytes\n", send_len);
470 for (cp = xbuf; cp < &xbuf[send_len]; cp++)
471 fprintf(stderr, "%02x ", (unsigned char) *cp);
472 fprintf(stderr, "\n");
473#endif
474 xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len);
475
476#if ENABLE_FEATURE_TFTP_PROGRESS_BAR
477 if (is_bb_progress_inited(&G.pmt))
478 tftp_progress_update();
479#endif
480 /* Was it final ACK? then exit */
481 if (finished && (opcode == TFTP_ACK))
482 goto ret;
483
484 recv_again:
485 /* Receive packet */
486 /*pfd[0].fd = socket_fd;*/
487 pfd[0].events = POLLIN;
488 switch (safe_poll(pfd, 1, waittime_ms)) {
489 default:
490 /*bb_perror_msg("poll"); - done in safe_poll */
491 goto ret;
492 case 0:
493 retries--;
494 if (retries == 0) {
495 tftp_progress_done();
496 bb_error_msg("timeout");
497 goto ret; /* no err packet sent */
498 }
499
500 /* exponential backoff with limit */
501 waittime_ms += waittime_ms/2;
502 if (waittime_ms > TFTP_MAXTIMEOUT_MS) {
503 waittime_ms = TFTP_MAXTIMEOUT_MS;
504 }
505
506 goto send_again; /* resend last sent pkt */
507 case 1:
508 if (!our_lsa) {
509 /* tftp (not tftpd!) receiving 1st packet */
510 our_lsa = ((void*)(ptrdiff_t)-1); /* not NULL */
511 len = recvfrom(socket_fd, rbuf, io_bufsize, 0,
512 &peer_lsa->u.sa, &peer_lsa->len);
513 /* Our first dgram went to port 69
514 * but reply may come from different one.
515 * Remember and use this new port (and IP) */
516 if (len >= 0)
517 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
518 } else {
519 /* tftpd, or not the very first packet:
520 * socket is connect()ed, can just read from it. */
521 /* Don't full_read()!
522 * This is not TCP, one read == one pkt! */
523 len = safe_read(socket_fd, rbuf, io_bufsize);
524 }
525 if (len < 0) {
526 goto send_read_err_pkt;
527 }
528 if (len < 4) { /* too small? */
529 goto recv_again;
530 }
531 }
532
533 /* Process recv'ed packet */
534 opcode = ntohs( ((uint16_t*)rbuf)[0] );
535 recv_blk = ntohs( ((uint16_t*)rbuf)[1] );
536#if ENABLE_TFTP_DEBUG
537 fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk);
538#endif
539 if (opcode == TFTP_ERROR) {
540 static const char errcode_str[] ALIGN1 =
541 "\0"
542 "file not found\0"
543 "access violation\0"
544 "disk full\0"
545 "bad operation\0"
546 "unknown transfer id\0"
547 "file already exists\0"
548 "no such user\0"
549 "bad option";
550
551 const char *msg = "";
552
553 if (len > 4 && rbuf[4] != '\0') {
554 msg = &rbuf[4];
555 rbuf[io_bufsize - 1] = '\0'; /* paranoia */
556 } else if (recv_blk <= 8) {
557 msg = nth_string(errcode_str, recv_blk);
558 }
559 bb_error_msg("server error: (%u) %s", recv_blk, msg);
560 goto ret;
561 }
562
563#if ENABLE_FEATURE_TFTP_BLOCKSIZE
564 if (expect_OACK) {
565 expect_OACK = 0;
566 if (opcode == TFTP_OACK) {
567 /* server seems to support options */
568 char *res;
569
570 res = tftp_get_option("blksize", &rbuf[2], len - 2);
571 if (res) {
572 blksize = tftp_blksize_check(res, blksize);
573 if (blksize < 0) {
574 G_error_pkt_reason = ERR_BAD_OPT;
575 goto send_err_pkt;
576 }
577 io_bufsize = blksize + 4;
578 }
579# if ENABLE_FEATURE_TFTP_PROGRESS_BAR
580 if (remote_file && G.size == 0) { /* if we don't know it yet */
581 res = tftp_get_option("tsize", &rbuf[2], len - 2);
582 if (res) {
583 G.size = bb_strtoull(res, NULL, 10);
584 if (G.size)
585 tftp_progress_init();
586 }
587 }
588# endif
589 if (CMD_GET(option_mask32)) {
590 /* We'll send ACK for OACK,
591 * such ACK has "block no" of 0 */
592 block_nr = 0;
593 }
594 continue;
595 }
596 /* rfc2347:
597 * "An option not acknowledged by the server
598 * must be ignored by the client and server
599 * as if it were never requested." */
600 if (blksize != TFTP_BLKSIZE_DEFAULT)
601 bb_error_msg("falling back to blocksize "TFTP_BLKSIZE_DEFAULT_STR);
602 blksize = TFTP_BLKSIZE_DEFAULT;
603 io_bufsize = TFTP_BLKSIZE_DEFAULT + 4;
604 }
605#endif
606 /* block_nr is already advanced to next block# we expect
607 * to get / block# we are about to send next time */
608
609 if (CMD_GET(option_mask32) && (opcode == TFTP_DATA)) {
610 if (recv_blk == block_nr) {
611 int sz = full_write(local_fd, &rbuf[4], len - 4);
612 if (sz != len - 4) {
613 strcpy(G_error_pkt_str, bb_msg_write_error);
614 G_error_pkt_reason = ERR_WRITE;
615 goto send_err_pkt;
616 }
617 if (sz != blksize) {
618 finished = 1;
619 }
620 IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += sz;)
621 continue; /* send ACK */
622 }
623/* Disabled to cope with servers with Sorcerer's Apprentice Syndrome */
624#if 0
625 if (recv_blk == (block_nr - 1)) {
626 /* Server lost our TFTP_ACK. Resend it */
627 block_nr = recv_blk;
628 continue;
629 }
630#endif
631 }
632
633 if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) {
634 /* did peer ACK our last DATA pkt? */
635 if (recv_blk == (uint16_t) (block_nr - 1)) {
636 if (finished)
637 goto ret;
638 continue; /* send next block */
639 }
640 }
641 /* Awww... recv'd packet is not recognized! */
642 goto recv_again;
643 /* why recv_again? - rfc1123 says:
644 * "The sender (i.e., the side originating the DATA packets)
645 * must never resend the current DATA packet on receipt
646 * of a duplicate ACK".
647 * DATA pkts are resent ONLY on timeout.
648 * Thus "goto send_again" will ba a bad mistake above.
649 * See:
650 * http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome
651 */
652 } /* end of "while (1)" */
653 ret:
654 if (ENABLE_FEATURE_CLEAN_UP) {
655 close(local_fd);
656 close(socket_fd);
657 free(xbuf);
658 free(rbuf);
659 }
660 return finished == 0; /* returns 1 on failure */
661
662 send_read_err_pkt:
663 strcpy(G_error_pkt_str, bb_msg_read_error);
664 send_err_pkt:
665 if (G_error_pkt_str[0])
666 bb_error_msg("%s", G_error_pkt_str);
667 G.error_pkt[1] = TFTP_ERROR;
668 xsendto(socket_fd, G.error_pkt, 4 + 1 + strlen(G_error_pkt_str),
669 &peer_lsa->u.sa, peer_lsa->len);
670 return EXIT_FAILURE;
671#undef remote_file
672}
673
674#if ENABLE_TFTP
675
676int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
677int tftp_main(int argc UNUSED_PARAM, char **argv)
678{
679 len_and_sockaddr *peer_lsa;
680 const char *local_file = NULL;
681 const char *remote_file = NULL;
682# if ENABLE_FEATURE_TFTP_BLOCKSIZE
683 const char *blksize_str = TFTP_BLKSIZE_DEFAULT_STR;
684 int blksize;
685# endif
686 int result;
687 int port;
688 IF_GETPUT(int opt;)
689
690 INIT_G();
691
692 /* -p or -g is mandatory, and they are mutually exclusive */
693 opt_complementary = "" IF_FEATURE_TFTP_GET("g:") IF_FEATURE_TFTP_PUT("p:")
694 IF_GETPUT("g--p:p--g:");
695
696 IF_GETPUT(opt =) getopt32(argv,
697 IF_FEATURE_TFTP_GET("g") IF_FEATURE_TFTP_PUT("p")
698 "l:r:" IF_FEATURE_TFTP_BLOCKSIZE("b:"),
699 &local_file, &remote_file
700 IF_FEATURE_TFTP_BLOCKSIZE(, &blksize_str));
701 argv += optind;
702
703# if ENABLE_FEATURE_TFTP_BLOCKSIZE
704 /* Check if the blksize is valid:
705 * RFC2348 says between 8 and 65464 */
706 blksize = tftp_blksize_check(blksize_str, 65564);
707 if (blksize < 0) {
708 //bb_error_msg("bad block size");
709 return EXIT_FAILURE;
710 }
711# endif
712
713 if (remote_file) {
714 if (!local_file) {
715 const char *slash = strrchr(remote_file, '/');
716 local_file = slash ? slash + 1 : remote_file;
717 }
718 } else {
719 remote_file = local_file;
720 }
721
722 /* Error if filename or host is not known */
723 if (!remote_file || !argv[0])
724 bb_show_usage();
725
726 port = bb_lookup_port(argv[1], "udp", 69);
727 peer_lsa = xhost2sockaddr(argv[0], port);
728
729# if ENABLE_TFTP_DEBUG
730 fprintf(stderr, "using server '%s', remote_file '%s', local_file '%s'\n",
731 xmalloc_sockaddr2dotted(&peer_lsa->u.sa),
732 remote_file, local_file);
733# endif
734
735# if ENABLE_FEATURE_TFTP_PROGRESS_BAR
736 G.file = remote_file;
737# endif
738 result = tftp_protocol(
739 NULL /*our_lsa*/, peer_lsa,
740 local_file, remote_file
741 IF_FEATURE_TFTP_BLOCKSIZE(, 1 /* want_transfer_size */)
742 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
743 );
744 tftp_progress_done();
745
746 if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) {
747 unlink(local_file);
748 }
749 return result;
750}
751
752#endif /* ENABLE_TFTP */
753
754#if ENABLE_TFTPD
755int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
756int tftpd_main(int argc UNUSED_PARAM, char **argv)
757{
758 len_and_sockaddr *our_lsa;
759 len_and_sockaddr *peer_lsa;
760 char *local_file, *mode, *user_opt;
761 const char *error_msg;
762 int opt, result, opcode;
763 IF_FEATURE_TFTP_BLOCKSIZE(int blksize = TFTP_BLKSIZE_DEFAULT;)
764 IF_FEATURE_TFTP_BLOCKSIZE(int want_transfer_size = 0;)
765
766 INIT_G();
767
768 our_lsa = get_sock_lsa(STDIN_FILENO);
769 if (!our_lsa) {
770 /* This is confusing:
771 *bb_error_msg_and_die("stdin is not a socket");
772 * Better: */
773 bb_show_usage();
774 /* Help text says that tftpd must be used as inetd service,
775 * which is by far the most usual cause of get_sock_lsa
776 * failure */
777 }
778 peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len);
779 peer_lsa->len = our_lsa->len;
780
781 /* Shifting to not collide with TFTP_OPTs */
782 opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:l", &user_opt) << 8);
783 argv += optind;
784 if (opt & TFTPD_OPT_l) {
785 openlog(applet_name, LOG_PID, LOG_DAEMON);
786 logmode = LOGMODE_SYSLOG;
787 }
788 if (opt & TFTPD_OPT_u) {
789 /* Must be before xchroot */
790 G.pw = xgetpwnam(user_opt);
791 }
792 if (argv[0]) {
793 xchroot(argv[0]);
794 }
795
796 result = recv_from_to(STDIN_FILENO, G.block_buf, sizeof(G.block_buf),
797 0 /* flags */,
798 &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len);
799
800 error_msg = "malformed packet";
801 opcode = ntohs(*(uint16_t*)G.block_buf);
802 if (result < 4 || result >= sizeof(G.block_buf)
803 || G.block_buf[result-1] != '\0'
804 || (IF_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */
805 IF_GETPUT(&&)
806 IF_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */
807 )
808 ) {
809 goto err;
810 }
811 local_file = G.block_buf + 2;
812 if (local_file[0] == '.' || strstr(local_file, "/.")) {
813 error_msg = "dot in file name";
814 goto err;
815 }
816 mode = local_file + strlen(local_file) + 1;
817 /* RFC 1350 says mode string is case independent */
818 if (mode >= G.block_buf + result || strcasecmp(mode, "octet") != 0) {
819 goto err;
820 }
821# if ENABLE_FEATURE_TFTP_BLOCKSIZE
822 {
823 char *res;
824 char *opt_str = mode + sizeof("octet");
825 int opt_len = G.block_buf + result - opt_str;
826 if (opt_len > 0) {
827 res = tftp_get_option("blksize", opt_str, opt_len);
828 if (res) {
829 blksize = tftp_blksize_check(res, 65564);
830 if (blksize < 0) {
831 G_error_pkt_reason = ERR_BAD_OPT;
832 /* will just send error pkt */
833 goto do_proto;
834 }
835 }
836 if (opcode != TFTP_WRQ /* download? */
837 /* did client ask us about file size? */
838 && tftp_get_option("tsize", opt_str, opt_len)
839 ) {
840 want_transfer_size = 1;
841 }
842 }
843 }
844# endif
845
846 if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) {
847 if (opt & TFTPD_OPT_r) {
848 /* This would mean "disk full" - not true */
849 /*G_error_pkt_reason = ERR_WRITE;*/
850 error_msg = bb_msg_write_error;
851 goto err;
852 }
853 IF_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */
854 } else {
855 IF_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */
856 }
857
858 /* NB: if G_error_pkt_str or G_error_pkt_reason is set up,
859 * tftp_protocol() just sends one error pkt and returns */
860
861 do_proto:
862 close(STDIN_FILENO); /* close old, possibly wildcard socket */
863 /* tftp_protocol() will create new one, bound to particular local IP */
864 result = tftp_protocol(
865 our_lsa, peer_lsa,
866 local_file IF_TFTP(, NULL /*remote_file*/)
867 IF_FEATURE_TFTP_BLOCKSIZE(, want_transfer_size)
868 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
869 );
870
871 return result;
872 err:
873 strcpy(G_error_pkt_str, error_msg);
874 goto do_proto;
875}
876
877#endif /* ENABLE_TFTPD */
878
879#endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */
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