blob: 48bc6fa4612adbaafe39dc7acfb3e191b017c48a
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 */ |
87 | enum { |
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 | |
116 | struct 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) |
130 | struct 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 |
139 | static void tftp_progress_update(void) |
140 | { |
141 | bb_progress_update(&G.pmt, 0, G.pos, G.size); |
142 | } |
143 | static void tftp_progress_init(void) |
144 | { |
145 | bb_progress_init(&G.pmt, G.file); |
146 | tftp_progress_update(); |
147 | } |
148 | static 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 | |
163 | static 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 | |
182 | static 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 | |
219 | static 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") >= (uint32_t) 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 | |
676 | int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
677 | int 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 |
755 | int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
756 | int 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 >= (int) 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 */ |
880 |