source: MondoRescue/branches/3.3/mindi-busybox/networking/tftp.c@ 3621

Last change on this file since 3621 was 3621, checked in by Bruno Cornec, 7 years ago

New 3?3 banch for incorporation of latest busybox 1.25. Changing minor version to handle potential incompatibilities.
File size: 24.6 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 "common_bufsiz.h"
55#include <syslog.h>
56
57#if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT
58
59#define TFTP_BLKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */
60#define TFTP_BLKSIZE_DEFAULT_STR "512"
61/* Was 50 ms but users asked to bump it up a bit */
62#define TFTP_TIMEOUT_MS 100
63#define TFTP_MAXTIMEOUT_MS 2000
64#define TFTP_NUM_RETRIES 12 /* number of backed-off retries */
65
66/* opcodes we support */
67#define TFTP_RRQ 1
68#define TFTP_WRQ 2
69#define TFTP_DATA 3
70#define TFTP_ACK 4
71#define TFTP_ERROR 5
72#define TFTP_OACK 6
73
74/* error codes sent over network (we use only 0, 1, 3 and 8) */
75/* generic (error message is included in the packet) */
76#define ERR_UNSPEC 0
77#define ERR_NOFILE 1
78#define ERR_ACCESS 2
79/* disk full or allocation exceeded */
80#define ERR_WRITE 3
81#define ERR_OP 4
82#define ERR_BAD_ID 5
83#define ERR_EXIST 6
84#define ERR_BAD_USER 7
85#define ERR_BAD_OPT 8
86
87/* masks coming from getopt32 */
88enum {
89 TFTP_OPT_GET = (1 << 0),
90 TFTP_OPT_PUT = (1 << 1),
91 /* pseudo option: if set, it's tftpd */
92 TFTPD_OPT = (1 << 7) * ENABLE_TFTPD,
93 TFTPD_OPT_r = (1 << 8) * ENABLE_TFTPD,
94 TFTPD_OPT_c = (1 << 9) * ENABLE_TFTPD,
95 TFTPD_OPT_u = (1 << 10) * ENABLE_TFTPD,
96 TFTPD_OPT_l = (1 << 11) * ENABLE_TFTPD,
97};
98
99#if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT
100#define IF_GETPUT(...)
101#define CMD_GET(cmd) 1
102#define CMD_PUT(cmd) 0
103#elif !ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT
104#define IF_GETPUT(...)
105#define CMD_GET(cmd) 0
106#define CMD_PUT(cmd) 1
107#else
108#define IF_GETPUT(...) __VA_ARGS__
109#define CMD_GET(cmd) ((cmd) & TFTP_OPT_GET)
110#define CMD_PUT(cmd) ((cmd) & TFTP_OPT_PUT)
111#endif
112/* NB: in the code below
113 * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive
114 */
115
116
117struct globals {
118 /* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */
119 uint8_t error_pkt[4 + 32];
120 struct passwd *pw;
121 /* Used in tftpd_main() for initial packet */
122 /* Some HP PA-RISC firmware always sends fixed 516-byte requests */
123 char block_buf[516];
124 char block_buf_tail[1];
125#if ENABLE_FEATURE_TFTP_PROGRESS_BAR
126 off_t pos;
127 off_t size;
128 const char *file;
129 bb_progress_t pmt;
130#endif
131} FIX_ALIASING;
132#define G (*(struct globals*)bb_common_bufsiz1)
133#define INIT_G() do { \
134 setup_common_bufsiz(); \
135 BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
136} while (0)
137
138#define G_error_pkt_reason (G.error_pkt[3])
139#define G_error_pkt_str ((char*)(G.error_pkt + 4))
140
141#if ENABLE_FEATURE_TFTP_PROGRESS_BAR
142static void tftp_progress_update(void)
143{
144 bb_progress_update(&G.pmt, 0, G.pos, G.size);
145}
146static void tftp_progress_init(void)
147{
148 bb_progress_init(&G.pmt, G.file);
149 tftp_progress_update();
150}
151static void tftp_progress_done(void)
152{
153 if (is_bb_progress_inited(&G.pmt)) {
154 tftp_progress_update();
155 bb_putchar_stderr('\n');
156 bb_progress_free(&G.pmt);
157 }
158}
159#else
160# define tftp_progress_init() ((void)0)
161# define tftp_progress_done() ((void)0)
162#endif
163
164#if ENABLE_FEATURE_TFTP_BLOCKSIZE
165
166static int tftp_blksize_check(const char *blksize_str, int maxsize)
167{
168 /* Check if the blksize is valid:
169 * RFC2348 says between 8 and 65464,
170 * but our implementation makes it impossible
171 * to use blksizes smaller than 22 octets. */
172 unsigned blksize = bb_strtou(blksize_str, NULL, 10);
173 if (errno
174 || (blksize < 24) || (blksize > maxsize)
175 ) {
176 bb_error_msg("bad blocksize '%s'", blksize_str);
177 return -1;
178 }
179# if ENABLE_TFTP_DEBUG
180 bb_error_msg("using blksize %u", blksize);
181# endif
182 return blksize;
183}
184
185static char *tftp_get_option(const char *option, char *buf, int len)
186{
187 int opt_val = 0;
188 int opt_found = 0;
189 int k;
190
191 /* buf points to:
192 * "opt_name<NUL>opt_val<NUL>opt_name2<NUL>opt_val2<NUL>..." */
193
194 while (len > 0) {
195 /* Make sure options are terminated correctly */
196 for (k = 0; k < len; k++) {
197 if (buf[k] == '\0') {
198 goto nul_found;
199 }
200 }
201 return NULL;
202 nul_found:
203 if (opt_val == 0) { /* it's "name" part */
204 if (strcasecmp(buf, option) == 0) {
205 opt_found = 1;
206 }
207 } else if (opt_found) {
208 return buf;
209 }
210
211 k++;
212 buf += k;
213 len -= k;
214 opt_val ^= 1;
215 }
216
217 return NULL;
218}
219
220#endif
221
222static int tftp_protocol(
223 /* NULL if tftp, !NULL if tftpd: */
224 len_and_sockaddr *our_lsa,
225 len_and_sockaddr *peer_lsa,
226 const char *local_file
227 IF_TFTP(, const char *remote_file)
228#if !ENABLE_TFTP
229# define remote_file NULL
230#endif
231 /* 1 for tftp; 1/0 for tftpd depending whether client asked about it: */
232 IF_FEATURE_TFTP_BLOCKSIZE(, int want_transfer_size)
233 IF_FEATURE_TFTP_BLOCKSIZE(, int blksize))
234{
235#if !ENABLE_FEATURE_TFTP_BLOCKSIZE
236 enum { blksize = TFTP_BLKSIZE_DEFAULT };
237#endif
238
239 struct pollfd pfd[1];
240#define socket_fd (pfd[0].fd)
241 int len;
242 int send_len;
243 IF_FEATURE_TFTP_BLOCKSIZE(smallint expect_OACK = 0;)
244 smallint finished = 0;
245 uint16_t opcode;
246 uint16_t block_nr;
247 uint16_t recv_blk;
248 int open_mode, local_fd;
249 int retries, waittime_ms;
250 int io_bufsize = blksize + 4;
251 char *cp;
252 /* Can't use RESERVE_CONFIG_BUFFER here since the allocation
253 * size varies meaning BUFFERS_GO_ON_STACK would fail.
254 *
255 * We must keep the transmit and receive buffers separate
256 * in case we rcv a garbage pkt - we need to rexmit the last pkt.
257 */
258 char *xbuf = xmalloc(io_bufsize);
259 char *rbuf = xmalloc(io_bufsize);
260
261 socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0);
262 setsockopt_reuseaddr(socket_fd);
263
264 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
265 /* Create a socket which is:
266 * 1. bound to IP:port peer sent 1st datagram to,
267 * 2. connected to peer's IP:port
268 * This way we will answer from the IP:port peer
269 * expects, will not get any other packets on
270 * the socket, and also plain read/write will work. */
271 xbind(socket_fd, &our_lsa->u.sa, our_lsa->len);
272 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
273
274 /* Is there an error already? Send pkt and bail out */
275 if (G_error_pkt_reason || G_error_pkt_str[0])
276 goto send_err_pkt;
277
278 if (G.pw) {
279 change_identity(G.pw); /* initgroups, setgid, setuid */
280 }
281 }
282
283 /* Prepare open mode */
284 if (CMD_PUT(option_mask32)) {
285 open_mode = O_RDONLY;
286 } else {
287 open_mode = O_WRONLY | O_TRUNC | O_CREAT;
288#if ENABLE_TFTPD
289 if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) {
290 /* tftpd without -c */
291 open_mode = O_WRONLY | O_TRUNC;
292 }
293#endif
294 }
295
296 /* Examples of network traffic.
297 * Note two cases when ACKs with block# of 0 are sent.
298 *
299 * Download without options:
300 * tftp -> "\0\1FILENAME\0octet\0"
301 * "\0\3\0\1FILEDATA..." <- tftpd
302 * tftp -> "\0\4\0\1"
303 * ...
304 * Download with option of blksize 16384:
305 * tftp -> "\0\1FILENAME\0octet\0blksize\00016384\0"
306 * "\0\6blksize\00016384\0" <- tftpd
307 * tftp -> "\0\4\0\0"
308 * "\0\3\0\1FILEDATA..." <- tftpd
309 * tftp -> "\0\4\0\1"
310 * ...
311 * Upload without options:
312 * tftp -> "\0\2FILENAME\0octet\0"
313 * "\0\4\0\0" <- tftpd
314 * tftp -> "\0\3\0\1FILEDATA..."
315 * "\0\4\0\1" <- tftpd
316 * ...
317 * Upload with option of blksize 16384:
318 * tftp -> "\0\2FILENAME\0octet\0blksize\00016384\0"
319 * "\0\6blksize\00016384\0" <- tftpd
320 * tftp -> "\0\3\0\1FILEDATA..."
321 * "\0\4\0\1" <- tftpd
322 * ...
323 */
324 block_nr = 1;
325 cp = xbuf + 2;
326
327 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
328 /* Open file (must be after changing user) */
329 local_fd = open(local_file, open_mode, 0666);
330 if (local_fd < 0) {
331 G_error_pkt_reason = ERR_NOFILE;
332 strcpy(G_error_pkt_str, "can't open file");
333 goto send_err_pkt;
334 }
335/* gcc 4.3.1 would NOT optimize it out as it should! */
336#if ENABLE_FEATURE_TFTP_BLOCKSIZE
337 if (blksize != TFTP_BLKSIZE_DEFAULT || want_transfer_size) {
338 /* Create and send OACK packet. */
339 /* For the download case, block_nr is still 1 -
340 * we expect 1st ACK from peer to be for (block_nr-1),
341 * that is, for "block 0" which is our OACK pkt */
342 opcode = TFTP_OACK;
343 goto add_blksize_opt;
344 }
345#endif
346 if (CMD_GET(option_mask32)) {
347 /* It's upload and we don't send OACK.
348 * We must ACK 1st packet (with filename)
349 * as if it is "block 0" */
350 block_nr = 0;
351 }
352 } else { /* tftp */
353 /* Open file (must be after changing user) */
354 local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO;
355 if (NOT_LONE_DASH(local_file))
356 local_fd = xopen(local_file, open_mode);
357/* Removing #if, or using if() statement instead of #if may lead to
358 * "warning: null argument where non-null required": */
359#if ENABLE_TFTP
360 /* tftp */
361
362 /* We can't (and don't really need to) bind the socket:
363 * we don't know from which local IP datagrams will be sent,
364 * but kernel will pick the same IP every time (unless routing
365 * table is changed), thus peer will see dgrams consistently
366 * coming from the same IP.
367 * We would like to connect the socket, but since peer's
368 * UDP code can be less perfect than ours, _peer's_ IP:port
369 * in replies may differ from IP:port we used to send
370 * our first packet. We can connect() only when we get
371 * first reply. */
372
373 /* build opcode */
374 opcode = TFTP_WRQ;
375 if (CMD_GET(option_mask32)) {
376 opcode = TFTP_RRQ;
377 }
378 /* add filename and mode */
379 /* fill in packet if the filename fits into xbuf */
380 len = strlen(remote_file) + 1;
381 if (2 + len + sizeof("octet") >= io_bufsize) {
382 bb_error_msg("remote filename is too long");
383 goto ret;
384 }
385 strcpy(cp, remote_file);
386 cp += len;
387 /* add "mode" part of the packet */
388 strcpy(cp, "octet");
389 cp += sizeof("octet");
390
391# if ENABLE_FEATURE_TFTP_BLOCKSIZE
392 if (blksize == TFTP_BLKSIZE_DEFAULT && !want_transfer_size)
393 goto send_pkt;
394
395 /* Need to add option to pkt */
396 if ((&xbuf[io_bufsize - 1] - cp) < sizeof("blksize NNNNN tsize ") + sizeof(off_t)*3) {
397 bb_error_msg("remote filename is too long");
398 goto ret;
399 }
400 expect_OACK = 1;
401# endif
402#endif /* ENABLE_TFTP */
403
404#if ENABLE_FEATURE_TFTP_BLOCKSIZE
405 add_blksize_opt:
406 if (blksize != TFTP_BLKSIZE_DEFAULT) {
407 /* add "blksize", <nul>, blksize, <nul> */
408 strcpy(cp, "blksize");
409 cp += sizeof("blksize");
410 cp += snprintf(cp, 6, "%d", blksize) + 1;
411 }
412 if (want_transfer_size) {
413 /* add "tsize", <nul>, size, <nul> (see RFC2349) */
414 /* if tftp and downloading, we send "0" (since we opened local_fd with O_TRUNC)
415 * and this makes server to send "tsize" option with the size */
416 /* if tftp and uploading, we send file size (maybe dont, to not confuse old servers???) */
417 /* if tftpd and downloading, we are answering to client's request */
418 /* if tftpd and uploading: !want_transfer_size, this code is not executed */
419 struct stat st;
420 strcpy(cp, "tsize");
421 cp += sizeof("tsize");
422 st.st_size = 0;
423 fstat(local_fd, &st);
424 cp += sprintf(cp, "%"OFF_FMT"u", (off_t)st.st_size) + 1;
425# if ENABLE_FEATURE_TFTP_PROGRESS_BAR
426 /* Save for progress bar. If 0 (tftp downloading),
427 * we look at server's reply later */
428 G.size = st.st_size;
429 if (remote_file && st.st_size)
430 tftp_progress_init();
431# endif
432 }
433#endif
434 /* First packet is built, so skip packet generation */
435 goto send_pkt;
436 }
437
438 /* Using mostly goto's - continue/break will be less clear
439 * in where we actually jump to */
440 while (1) {
441 /* Build ACK or DATA */
442 cp = xbuf + 2;
443 *((uint16_t*)cp) = htons(block_nr);
444 cp += 2;
445 block_nr++;
446 opcode = TFTP_ACK;
447 if (CMD_PUT(option_mask32)) {
448 opcode = TFTP_DATA;
449 len = full_read(local_fd, cp, blksize);
450 if (len < 0) {
451 goto send_read_err_pkt;
452 }
453 if (len != blksize) {
454 finished = 1;
455 }
456 cp += len;
457 IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += len;)
458 }
459 send_pkt:
460 /* Send packet */
461 *((uint16_t*)xbuf) = htons(opcode); /* fill in opcode part */
462 send_len = cp - xbuf;
463 /* NB: send_len value is preserved in code below
464 * for potential resend */
465
466 retries = TFTP_NUM_RETRIES; /* re-initialize */
467 waittime_ms = TFTP_TIMEOUT_MS;
468
469 send_again:
470#if ENABLE_TFTP_DEBUG
471 fprintf(stderr, "sending %u bytes\n", send_len);
472 for (cp = xbuf; cp < &xbuf[send_len]; cp++)
473 fprintf(stderr, "%02x ", (unsigned char) *cp);
474 fprintf(stderr, "\n");
475#endif
476 xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len);
477
478#if ENABLE_FEATURE_TFTP_PROGRESS_BAR
479 if (is_bb_progress_inited(&G.pmt))
480 tftp_progress_update();
481#endif
482 /* Was it final ACK? then exit */
483 if (finished && (opcode == TFTP_ACK))
484 goto ret;
485
486 recv_again:
487 /* Receive packet */
488 /*pfd[0].fd = socket_fd;*/
489 pfd[0].events = POLLIN;
490 switch (safe_poll(pfd, 1, waittime_ms)) {
491 default:
492 /*bb_perror_msg("poll"); - done in safe_poll */
493 goto ret;
494 case 0:
495 retries--;
496 if (retries == 0) {
497 tftp_progress_done();
498 bb_error_msg("timeout");
499 goto ret; /* no err packet sent */
500 }
501
502 /* exponential backoff with limit */
503 waittime_ms += waittime_ms/2;
504 if (waittime_ms > TFTP_MAXTIMEOUT_MS) {
505 waittime_ms = TFTP_MAXTIMEOUT_MS;
506 }
507
508 goto send_again; /* resend last sent pkt */
509 case 1:
510 if (!our_lsa) {
511 /* tftp (not tftpd!) receiving 1st packet */
512 our_lsa = ((void*)(ptrdiff_t)-1); /* not NULL */
513 len = recvfrom(socket_fd, rbuf, io_bufsize, 0,
514 &peer_lsa->u.sa, &peer_lsa->len);
515 /* Our first dgram went to port 69
516 * but reply may come from different one.
517 * Remember and use this new port (and IP) */
518 if (len >= 0)
519 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
520 } else {
521 /* tftpd, or not the very first packet:
522 * socket is connect()ed, can just read from it. */
523 /* Don't full_read()!
524 * This is not TCP, one read == one pkt! */
525 len = safe_read(socket_fd, rbuf, io_bufsize);
526 }
527 if (len < 0) {
528 goto send_read_err_pkt;
529 }
530 if (len < 4) { /* too small? */
531 goto recv_again;
532 }
533 }
534
535 /* Process recv'ed packet */
536 opcode = ntohs( ((uint16_t*)rbuf)[0] );
537 recv_blk = ntohs( ((uint16_t*)rbuf)[1] );
538#if ENABLE_TFTP_DEBUG
539 fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk);
540#endif
541 if (opcode == TFTP_ERROR) {
542 static const char errcode_str[] ALIGN1 =
543 "\0"
544 "file not found\0"
545 "access violation\0"
546 "disk full\0"
547 "bad operation\0"
548 "unknown transfer id\0"
549 "file already exists\0"
550 "no such user\0"
551 "bad option";
552
553 const char *msg = "";
554
555 if (len > 4 && rbuf[4] != '\0') {
556 msg = &rbuf[4];
557 rbuf[io_bufsize - 1] = '\0'; /* paranoia */
558 } else if (recv_blk <= 8) {
559 msg = nth_string(errcode_str, recv_blk);
560 }
561 bb_error_msg("server error: (%u) %s", recv_blk, msg);
562 goto ret;
563 }
564
565#if ENABLE_FEATURE_TFTP_BLOCKSIZE
566 if (expect_OACK) {
567 expect_OACK = 0;
568 if (opcode == TFTP_OACK) {
569 /* server seems to support options */
570 char *res;
571
572 res = tftp_get_option("blksize", &rbuf[2], len - 2);
573 if (res) {
574 blksize = tftp_blksize_check(res, blksize);
575 if (blksize < 0) {
576 G_error_pkt_reason = ERR_BAD_OPT;
577 goto send_err_pkt;
578 }
579 io_bufsize = blksize + 4;
580 }
581# if ENABLE_FEATURE_TFTP_PROGRESS_BAR
582 if (remote_file && G.size == 0) { /* if we don't know it yet */
583 res = tftp_get_option("tsize", &rbuf[2], len - 2);
584 if (res) {
585 G.size = bb_strtoull(res, NULL, 10);
586 if (G.size)
587 tftp_progress_init();
588 }
589 }
590# endif
591 if (CMD_GET(option_mask32)) {
592 /* We'll send ACK for OACK,
593 * such ACK has "block no" of 0 */
594 block_nr = 0;
595 }
596 continue;
597 }
598 /* rfc2347:
599 * "An option not acknowledged by the server
600 * must be ignored by the client and server
601 * as if it were never requested." */
602 if (blksize != TFTP_BLKSIZE_DEFAULT)
603 bb_error_msg("falling back to blocksize "TFTP_BLKSIZE_DEFAULT_STR);
604 blksize = TFTP_BLKSIZE_DEFAULT;
605 io_bufsize = TFTP_BLKSIZE_DEFAULT + 4;
606 }
607#endif
608 /* block_nr is already advanced to next block# we expect
609 * to get / block# we are about to send next time */
610
611 if (CMD_GET(option_mask32) && (opcode == TFTP_DATA)) {
612 if (recv_blk == block_nr) {
613 int sz = full_write(local_fd, &rbuf[4], len - 4);
614 if (sz != len - 4) {
615 strcpy(G_error_pkt_str, bb_msg_write_error);
616 G_error_pkt_reason = ERR_WRITE;
617 goto send_err_pkt;
618 }
619 if (sz != blksize) {
620 finished = 1;
621 }
622 IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += sz;)
623 continue; /* send ACK */
624 }
625/* Disabled to cope with servers with Sorcerer's Apprentice Syndrome */
626#if 0
627 if (recv_blk == (block_nr - 1)) {
628 /* Server lost our TFTP_ACK. Resend it */
629 block_nr = recv_blk;
630 continue;
631 }
632#endif
633 }
634
635 if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) {
636 /* did peer ACK our last DATA pkt? */
637 if (recv_blk == (uint16_t) (block_nr - 1)) {
638 if (finished)
639 goto ret;
640 continue; /* send next block */
641 }
642 }
643 /* Awww... recv'd packet is not recognized! */
644 goto recv_again;
645 /* why recv_again? - rfc1123 says:
646 * "The sender (i.e., the side originating the DATA packets)
647 * must never resend the current DATA packet on receipt
648 * of a duplicate ACK".
649 * DATA pkts are resent ONLY on timeout.
650 * Thus "goto send_again" will ba a bad mistake above.
651 * See:
652 * http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome
653 */
654 } /* end of "while (1)" */
655 ret:
656 if (ENABLE_FEATURE_CLEAN_UP) {
657 close(local_fd);
658 close(socket_fd);
659 free(xbuf);
660 free(rbuf);
661 }
662 return finished == 0; /* returns 1 on failure */
663
664 send_read_err_pkt:
665 strcpy(G_error_pkt_str, bb_msg_read_error);
666 send_err_pkt:
667 if (G_error_pkt_str[0])
668 bb_error_msg("%s", G_error_pkt_str);
669 G.error_pkt[1] = TFTP_ERROR;
670 xsendto(socket_fd, G.error_pkt, 4 + 1 + strlen(G_error_pkt_str),
671 &peer_lsa->u.sa, peer_lsa->len);
672 return EXIT_FAILURE;
673#undef remote_file
674}
675
676#if ENABLE_TFTP
677
678int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
679int tftp_main(int argc UNUSED_PARAM, char **argv)
680{
681 len_and_sockaddr *peer_lsa;
682 const char *local_file = NULL;
683 const char *remote_file = NULL;
684# if ENABLE_FEATURE_TFTP_BLOCKSIZE
685 const char *blksize_str = TFTP_BLKSIZE_DEFAULT_STR;
686 int blksize;
687# endif
688 int result;
689 int port;
690 IF_GETPUT(int opt;)
691
692 INIT_G();
693
694 /* -p or -g is mandatory, and they are mutually exclusive */
695 opt_complementary = "" IF_FEATURE_TFTP_GET("g:") IF_FEATURE_TFTP_PUT("p:")
696 IF_GETPUT("g--p:p--g:");
697
698 IF_GETPUT(opt =) getopt32(argv,
699 IF_FEATURE_TFTP_GET("g") IF_FEATURE_TFTP_PUT("p")
700 "l:r:" IF_FEATURE_TFTP_BLOCKSIZE("b:"),
701 &local_file, &remote_file
702 IF_FEATURE_TFTP_BLOCKSIZE(, &blksize_str));
703 argv += optind;
704
705# if ENABLE_FEATURE_TFTP_BLOCKSIZE
706 /* Check if the blksize is valid:
707 * RFC2348 says between 8 and 65464 */
708 blksize = tftp_blksize_check(blksize_str, 65564);
709 if (blksize < 0) {
710 //bb_error_msg("bad block size");
711 return EXIT_FAILURE;
712 }
713# endif
714
715 if (remote_file) {
716 if (!local_file) {
717 const char *slash = strrchr(remote_file, '/');
718 local_file = slash ? slash + 1 : remote_file;
719 }
720 } else {
721 remote_file = local_file;
722 }
723
724 /* Error if filename or host is not known */
725 if (!remote_file || !argv[0])
726 bb_show_usage();
727
728 port = bb_lookup_port(argv[1], "udp", 69);
729 peer_lsa = xhost2sockaddr(argv[0], port);
730
731# if ENABLE_TFTP_DEBUG
732 fprintf(stderr, "using server '%s', remote_file '%s', local_file '%s'\n",
733 xmalloc_sockaddr2dotted(&peer_lsa->u.sa),
734 remote_file, local_file);
735# endif
736
737# if ENABLE_FEATURE_TFTP_PROGRESS_BAR
738 G.file = remote_file;
739# endif
740 result = tftp_protocol(
741 NULL /*our_lsa*/, peer_lsa,
742 local_file, remote_file
743 IF_FEATURE_TFTP_BLOCKSIZE(, 1 /* want_transfer_size */)
744 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
745 );
746 tftp_progress_done();
747
748 if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) {
749 unlink(local_file);
750 }
751 return result;
752}
753
754#endif /* ENABLE_TFTP */
755
756#if ENABLE_TFTPD
757int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
758int tftpd_main(int argc UNUSED_PARAM, char **argv)
759{
760 len_and_sockaddr *our_lsa;
761 len_and_sockaddr *peer_lsa;
762 char *mode, *user_opt;
763 char *local_file = local_file;
764 const char *error_msg;
765 int opt, result, opcode;
766 IF_FEATURE_TFTP_BLOCKSIZE(int blksize = TFTP_BLKSIZE_DEFAULT;)
767 IF_FEATURE_TFTP_BLOCKSIZE(int want_transfer_size = 0;)
768
769 INIT_G();
770
771 our_lsa = get_sock_lsa(STDIN_FILENO);
772 if (!our_lsa) {
773 /* This is confusing:
774 *bb_error_msg_and_die("stdin is not a socket");
775 * Better: */
776 bb_show_usage();
777 /* Help text says that tftpd must be used as inetd service,
778 * which is by far the most usual cause of get_sock_lsa
779 * failure */
780 }
781 peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len);
782 peer_lsa->len = our_lsa->len;
783
784 /* Shifting to not collide with TFTP_OPTs */
785 opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:l", &user_opt) << 8);
786 argv += optind;
787 if (opt & TFTPD_OPT_l) {
788 openlog(applet_name, LOG_PID, LOG_DAEMON);
789 logmode = LOGMODE_SYSLOG;
790 }
791 if (opt & TFTPD_OPT_u) {
792 /* Must be before xchroot */
793 G.pw = xgetpwnam(user_opt);
794 }
795 if (argv[0]) {
796 xchroot(argv[0]);
797 }
798
799 result = recv_from_to(STDIN_FILENO,
800 G.block_buf, sizeof(G.block_buf) + 1,
801 /* ^^^ sizeof+1 to reliably detect oversized input */
802 0 /* flags */,
803 &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len);
804
805 error_msg = "malformed packet";
806 opcode = ntohs(*(uint16_t*)G.block_buf);
807 if (result < 4 || result > sizeof(G.block_buf)
808 /*|| G.block_buf[result-1] != '\0' - bug compatibility, see below */
809 || (IF_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */
810 IF_GETPUT(&&)
811 IF_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */
812 )
813 ) {
814 goto err;
815 }
816 /* Some HP PA-RISC firmware always sends fixed 516-byte requests,
817 * with trailing garbage.
818 * Support that by not requiring NUL to be the last byte (see above).
819 * To make strXYZ() ops safe, force NUL termination:
820 */
821 G.block_buf_tail[0] = '\0';
822
823 local_file = G.block_buf + 2;
824 if (local_file[0] == '.' || strstr(local_file, "/.")) {
825 error_msg = "dot in file name";
826 goto err;
827 }
828 mode = local_file + strlen(local_file) + 1;
829 /* RFC 1350 says mode string is case independent */
830 if (mode >= G.block_buf + result || strcasecmp(mode, "octet") != 0) {
831 goto err;
832 }
833# if ENABLE_FEATURE_TFTP_BLOCKSIZE
834 {
835 char *res;
836 char *opt_str = mode + sizeof("octet");
837 int opt_len = G.block_buf + result - opt_str;
838 if (opt_len > 0) {
839 res = tftp_get_option("blksize", opt_str, opt_len);
840 if (res) {
841 blksize = tftp_blksize_check(res, 65564);
842 if (blksize < 0) {
843 G_error_pkt_reason = ERR_BAD_OPT;
844 /* will just send error pkt */
845 goto do_proto;
846 }
847 }
848 if (opcode != TFTP_WRQ /* download? */
849 /* did client ask us about file size? */
850 && tftp_get_option("tsize", opt_str, opt_len)
851 ) {
852 want_transfer_size = 1;
853 }
854 }
855 }
856# endif
857
858 if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) {
859 if (opt & TFTPD_OPT_r) {
860 /* This would mean "disk full" - not true */
861 /*G_error_pkt_reason = ERR_WRITE;*/
862 error_msg = bb_msg_write_error;
863 goto err;
864 }
865 IF_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */
866 } else {
867 IF_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */
868 }
869
870 /* NB: if G_error_pkt_str or G_error_pkt_reason is set up,
871 * tftp_protocol() just sends one error pkt and returns */
872
873 do_proto:
874 close(STDIN_FILENO); /* close old, possibly wildcard socket */
875 /* tftp_protocol() will create new one, bound to particular local IP */
876 result = tftp_protocol(
877 our_lsa, peer_lsa,
878 local_file IF_TFTP(, NULL /*remote_file*/)
879 IF_FEATURE_TFTP_BLOCKSIZE(, want_transfer_size)
880 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
881 );
882
883 return result;
884 err:
885 strcpy(G_error_pkt_str, error_msg);
886 goto do_proto;
887}
888
889#endif /* ENABLE_TFTPD */
890
891#endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */
Note: See TracBrowser for help on using the repository browser.