Contents of /tags/mkinitrd-6_1_11/busybox/networking/tftp.c
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Wed Oct 28 13:31:19 2009 UTC (14 years, 11 months ago) by niro
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Wed Oct 28 13:31:19 2009 UTC (14 years, 11 months ago) by niro
File MIME type: text/plain
File size: 20519 byte(s)
tagged 'mkinitrd-6_1_11'
1 | /* vi: set sw=4 ts=4: */ |
2 | /* ------------------------------------------------------------------------- |
3 | * tftp.c |
4 | * |
5 | * A simple tftp client/server for busybox. |
6 | * Tries to follow RFC1350. |
7 | * Only "octet" mode supported. |
8 | * Optional blocksize negotiation (RFC2347 + RFC2348) |
9 | * |
10 | * Copyright (C) 2001 Magnus Damm <damm@opensource.se> |
11 | * |
12 | * Parts of the code based on: |
13 | * |
14 | * atftp: Copyright (C) 2000 Jean-Pierre Lefebvre <helix@step.polymtl.ca> |
15 | * and Remi Lefebvre <remi@debian.org> |
16 | * |
17 | * utftp: Copyright (C) 1999 Uwe Ohse <uwe@ohse.de> |
18 | * |
19 | * tftpd added by Denys Vlasenko & Vladimir Dronnikov |
20 | * |
21 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
22 | * ------------------------------------------------------------------------- */ |
23 | |
24 | #include "libbb.h" |
25 | |
26 | #if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT |
27 | |
28 | #define TFTP_BLKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */ |
29 | #define TFTP_BLKSIZE_DEFAULT_STR "512" |
30 | #define TFTP_TIMEOUT_MS 50 |
31 | #define TFTP_MAXTIMEOUT_MS 2000 |
32 | #define TFTP_NUM_RETRIES 12 /* number of backed-off retries */ |
33 | |
34 | /* opcodes we support */ |
35 | #define TFTP_RRQ 1 |
36 | #define TFTP_WRQ 2 |
37 | #define TFTP_DATA 3 |
38 | #define TFTP_ACK 4 |
39 | #define TFTP_ERROR 5 |
40 | #define TFTP_OACK 6 |
41 | |
42 | /* error codes sent over network (we use only 0, 1, 3 and 8) */ |
43 | /* generic (error message is included in the packet) */ |
44 | #define ERR_UNSPEC 0 |
45 | #define ERR_NOFILE 1 |
46 | #define ERR_ACCESS 2 |
47 | /* disk full or allocation exceeded */ |
48 | #define ERR_WRITE 3 |
49 | #define ERR_OP 4 |
50 | #define ERR_BAD_ID 5 |
51 | #define ERR_EXIST 6 |
52 | #define ERR_BAD_USER 7 |
53 | #define ERR_BAD_OPT 8 |
54 | |
55 | /* masks coming from getopt32 */ |
56 | enum { |
57 | TFTP_OPT_GET = (1 << 0), |
58 | TFTP_OPT_PUT = (1 << 1), |
59 | /* pseudo option: if set, it's tftpd */ |
60 | TFTPD_OPT = (1 << 7) * ENABLE_TFTPD, |
61 | TFTPD_OPT_r = (1 << 8) * ENABLE_TFTPD, |
62 | TFTPD_OPT_c = (1 << 9) * ENABLE_TFTPD, |
63 | TFTPD_OPT_u = (1 << 10) * ENABLE_TFTPD, |
64 | }; |
65 | |
66 | #if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT |
67 | #define USE_GETPUT(...) |
68 | #define CMD_GET(cmd) 1 |
69 | #define CMD_PUT(cmd) 0 |
70 | #elif !ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT |
71 | #define USE_GETPUT(...) |
72 | #define CMD_GET(cmd) 0 |
73 | #define CMD_PUT(cmd) 1 |
74 | #else |
75 | #define USE_GETPUT(...) __VA_ARGS__ |
76 | #define CMD_GET(cmd) ((cmd) & TFTP_OPT_GET) |
77 | #define CMD_PUT(cmd) ((cmd) & TFTP_OPT_PUT) |
78 | #endif |
79 | /* NB: in the code below |
80 | * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive |
81 | */ |
82 | |
83 | |
84 | struct globals { |
85 | /* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */ |
86 | uint8_t error_pkt[4 + 32]; |
87 | char *user_opt; |
88 | /* used in tftpd_main(), a bit big for stack: */ |
89 | char block_buf[TFTP_BLKSIZE_DEFAULT]; |
90 | }; |
91 | #define G (*(struct globals*)&bb_common_bufsiz1) |
92 | #define block_buf (G.block_buf ) |
93 | #define user_opt (G.user_opt ) |
94 | #define error_pkt (G.error_pkt ) |
95 | #define INIT_G() do { } while (0) |
96 | |
97 | #define error_pkt_reason (error_pkt[3]) |
98 | #define error_pkt_str (error_pkt + 4) |
99 | |
100 | |
101 | #if ENABLE_FEATURE_TFTP_BLOCKSIZE |
102 | |
103 | static int tftp_blksize_check(const char *blksize_str, int maxsize) |
104 | { |
105 | /* Check if the blksize is valid: |
106 | * RFC2348 says between 8 and 65464, |
107 | * but our implementation makes it impossible |
108 | * to use blksizes smaller than 22 octets. */ |
109 | unsigned blksize = bb_strtou(blksize_str, NULL, 10); |
110 | if (errno |
111 | || (blksize < 24) || (blksize > maxsize) |
112 | ) { |
113 | bb_error_msg("bad blocksize '%s'", blksize_str); |
114 | return -1; |
115 | } |
116 | #if ENABLE_TFTP_DEBUG |
117 | bb_error_msg("using blksize %u", blksize); |
118 | #endif |
119 | return blksize; |
120 | } |
121 | |
122 | static char *tftp_get_option(const char *option, char *buf, int len) |
123 | { |
124 | int opt_val = 0; |
125 | int opt_found = 0; |
126 | int k; |
127 | |
128 | /* buf points to: |
129 | * "opt_name<NUL>opt_val<NUL>opt_name2<NUL>opt_val2<NUL>..." */ |
130 | |
131 | while (len > 0) { |
132 | /* Make sure options are terminated correctly */ |
133 | for (k = 0; k < len; k++) { |
134 | if (buf[k] == '\0') { |
135 | goto nul_found; |
136 | } |
137 | } |
138 | return NULL; |
139 | nul_found: |
140 | if (opt_val == 0) { /* it's "name" part */ |
141 | if (strcasecmp(buf, option) == 0) { |
142 | opt_found = 1; |
143 | } |
144 | } else if (opt_found) { |
145 | return buf; |
146 | } |
147 | |
148 | k++; |
149 | buf += k; |
150 | len -= k; |
151 | opt_val ^= 1; |
152 | } |
153 | |
154 | return NULL; |
155 | } |
156 | |
157 | #endif |
158 | |
159 | static int tftp_protocol( |
160 | len_and_sockaddr *our_lsa, |
161 | len_and_sockaddr *peer_lsa, |
162 | const char *local_file |
163 | USE_TFTP(, const char *remote_file) |
164 | USE_FEATURE_TFTP_BLOCKSIZE(USE_TFTPD(, void *tsize)) |
165 | USE_FEATURE_TFTP_BLOCKSIZE(, int blksize)) |
166 | { |
167 | #if !ENABLE_TFTP |
168 | #define remote_file NULL |
169 | #endif |
170 | #if !(ENABLE_FEATURE_TFTP_BLOCKSIZE && ENABLE_TFTPD) |
171 | #define tsize NULL |
172 | #endif |
173 | #if !ENABLE_FEATURE_TFTP_BLOCKSIZE |
174 | enum { blksize = TFTP_BLKSIZE_DEFAULT }; |
175 | #endif |
176 | |
177 | struct pollfd pfd[1]; |
178 | #define socket_fd (pfd[0].fd) |
179 | int len; |
180 | int send_len; |
181 | USE_FEATURE_TFTP_BLOCKSIZE(smallint want_option_ack = 0;) |
182 | smallint finished = 0; |
183 | uint16_t opcode; |
184 | uint16_t block_nr; |
185 | uint16_t recv_blk; |
186 | int open_mode, local_fd; |
187 | int retries, waittime_ms; |
188 | int io_bufsize = blksize + 4; |
189 | char *cp; |
190 | /* Can't use RESERVE_CONFIG_BUFFER here since the allocation |
191 | * size varies meaning BUFFERS_GO_ON_STACK would fail */ |
192 | /* We must keep the transmit and receive buffers seperate */ |
193 | /* In case we rcv a garbage pkt and we need to rexmit the last pkt */ |
194 | char *xbuf = xmalloc(io_bufsize); |
195 | char *rbuf = xmalloc(io_bufsize); |
196 | |
197 | socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0); |
198 | setsockopt_reuseaddr(socket_fd); |
199 | |
200 | block_nr = 1; |
201 | cp = xbuf + 2; |
202 | |
203 | if (!ENABLE_TFTP || our_lsa) { |
204 | /* tftpd */ |
205 | |
206 | /* Create a socket which is: |
207 | * 1. bound to IP:port peer sent 1st datagram to, |
208 | * 2. connected to peer's IP:port |
209 | * This way we will answer from the IP:port peer |
210 | * expects, will not get any other packets on |
211 | * the socket, and also plain read/write will work. */ |
212 | xbind(socket_fd, &our_lsa->u.sa, our_lsa->len); |
213 | xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len); |
214 | |
215 | /* Is there an error already? Send pkt and bail out */ |
216 | if (error_pkt_reason || error_pkt_str[0]) |
217 | goto send_err_pkt; |
218 | |
219 | if (CMD_GET(option_mask32)) { |
220 | /* it's upload - we must ACK 1st packet (with filename) |
221 | * as if it's "block 0" */ |
222 | block_nr = 0; |
223 | } |
224 | |
225 | if (user_opt) { |
226 | struct passwd *pw = getpwnam(user_opt); |
227 | if (!pw) |
228 | bb_error_msg_and_die("unknown user %s", user_opt); |
229 | change_identity(pw); /* initgroups, setgid, setuid */ |
230 | } |
231 | } |
232 | |
233 | /* Open local file (must be after changing user) */ |
234 | if (CMD_PUT(option_mask32)) { |
235 | open_mode = O_RDONLY; |
236 | } else { |
237 | open_mode = O_WRONLY | O_TRUNC | O_CREAT; |
238 | #if ENABLE_TFTPD |
239 | if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) { |
240 | /* tftpd without -c */ |
241 | open_mode = O_WRONLY | O_TRUNC; |
242 | } |
243 | #endif |
244 | } |
245 | if (!(option_mask32 & TFTPD_OPT)) { |
246 | local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO; |
247 | if (NOT_LONE_DASH(local_file)) |
248 | local_fd = xopen(local_file, open_mode); |
249 | } else { |
250 | local_fd = open(local_file, open_mode); |
251 | if (local_fd < 0) { |
252 | error_pkt_reason = ERR_NOFILE; |
253 | strcpy((char*)error_pkt_str, "can't open file"); |
254 | goto send_err_pkt; |
255 | } |
256 | } |
257 | |
258 | if (!ENABLE_TFTP || our_lsa) { |
259 | /* gcc 4.3.1 would NOT optimize it out as it should! */ |
260 | #if ENABLE_FEATURE_TFTP_BLOCKSIZE |
261 | if (blksize != TFTP_BLKSIZE_DEFAULT || tsize) { |
262 | /* Create and send OACK packet. */ |
263 | /* For the download case, block_nr is still 1 - |
264 | * we expect 1st ACK from peer to be for (block_nr-1), |
265 | * that is, for "block 0" which is our OACK pkt */ |
266 | opcode = TFTP_OACK; |
267 | goto add_blksize_opt; |
268 | } |
269 | #endif |
270 | } else { |
271 | /* Removing it, or using if() statement instead of #if may lead to |
272 | * "warning: null argument where non-null required": */ |
273 | #if ENABLE_TFTP |
274 | /* tftp */ |
275 | |
276 | /* We can't (and don't really need to) bind the socket: |
277 | * we don't know from which local IP datagrams will be sent, |
278 | * but kernel will pick the same IP every time (unless routing |
279 | * table is changed), thus peer will see dgrams consistently |
280 | * coming from the same IP. |
281 | * We would like to connect the socket, but since peer's |
282 | * UDP code can be less perfect than ours, _peer's_ IP:port |
283 | * in replies may differ from IP:port we used to send |
284 | * our first packet. We can connect() only when we get |
285 | * first reply. */ |
286 | |
287 | /* build opcode */ |
288 | opcode = TFTP_WRQ; |
289 | if (CMD_GET(option_mask32)) { |
290 | opcode = TFTP_RRQ; |
291 | } |
292 | /* add filename and mode */ |
293 | /* fill in packet if the filename fits into xbuf */ |
294 | len = strlen(remote_file) + 1; |
295 | if (2 + len + sizeof("octet") >= io_bufsize) { |
296 | bb_error_msg("remote filename is too long"); |
297 | goto ret; |
298 | } |
299 | strcpy(cp, remote_file); |
300 | cp += len; |
301 | /* add "mode" part of the package */ |
302 | strcpy(cp, "octet"); |
303 | cp += sizeof("octet"); |
304 | |
305 | #if ENABLE_FEATURE_TFTP_BLOCKSIZE |
306 | if (blksize == TFTP_BLKSIZE_DEFAULT) |
307 | goto send_pkt; |
308 | |
309 | /* Non-standard blocksize: add option to pkt */ |
310 | if ((&xbuf[io_bufsize - 1] - cp) < sizeof("blksize NNNNN")) { |
311 | bb_error_msg("remote filename is too long"); |
312 | goto ret; |
313 | } |
314 | want_option_ack = 1; |
315 | #endif |
316 | #endif /* ENABLE_TFTP */ |
317 | |
318 | #if ENABLE_FEATURE_TFTP_BLOCKSIZE |
319 | add_blksize_opt: |
320 | #if ENABLE_TFTPD |
321 | if (tsize) { |
322 | struct stat st; |
323 | /* add "tsize", <nul>, size, <nul> */ |
324 | strcpy(cp, "tsize"); |
325 | cp += sizeof("tsize"); |
326 | fstat(local_fd, &st); |
327 | cp += snprintf(cp, 10, "%u", (int) st.st_size) + 1; |
328 | } |
329 | #endif |
330 | if (blksize != TFTP_BLKSIZE_DEFAULT) { |
331 | /* add "blksize", <nul>, blksize, <nul> */ |
332 | strcpy(cp, "blksize"); |
333 | cp += sizeof("blksize"); |
334 | cp += snprintf(cp, 6, "%d", blksize) + 1; |
335 | } |
336 | #endif |
337 | /* First packet is built, so skip packet generation */ |
338 | goto send_pkt; |
339 | } |
340 | |
341 | /* Using mostly goto's - continue/break will be less clear |
342 | * in where we actually jump to */ |
343 | while (1) { |
344 | /* Build ACK or DATA */ |
345 | cp = xbuf + 2; |
346 | *((uint16_t*)cp) = htons(block_nr); |
347 | cp += 2; |
348 | block_nr++; |
349 | opcode = TFTP_ACK; |
350 | if (CMD_PUT(option_mask32)) { |
351 | opcode = TFTP_DATA; |
352 | len = full_read(local_fd, cp, blksize); |
353 | if (len < 0) { |
354 | goto send_read_err_pkt; |
355 | } |
356 | if (len != blksize) { |
357 | finished = 1; |
358 | } |
359 | cp += len; |
360 | } |
361 | send_pkt: |
362 | /* Send packet */ |
363 | *((uint16_t*)xbuf) = htons(opcode); /* fill in opcode part */ |
364 | send_len = cp - xbuf; |
365 | /* NB: send_len value is preserved in code below |
366 | * for potential resend */ |
367 | |
368 | retries = TFTP_NUM_RETRIES; /* re-initialize */ |
369 | waittime_ms = TFTP_TIMEOUT_MS; |
370 | |
371 | send_again: |
372 | #if ENABLE_TFTP_DEBUG |
373 | fprintf(stderr, "sending %u bytes\n", send_len); |
374 | for (cp = xbuf; cp < &xbuf[send_len]; cp++) |
375 | fprintf(stderr, "%02x ", (unsigned char) *cp); |
376 | fprintf(stderr, "\n"); |
377 | #endif |
378 | xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len); |
379 | /* Was it final ACK? then exit */ |
380 | if (finished && (opcode == TFTP_ACK)) |
381 | goto ret; |
382 | |
383 | recv_again: |
384 | /* Receive packet */ |
385 | /*pfd[0].fd = socket_fd;*/ |
386 | pfd[0].events = POLLIN; |
387 | switch (safe_poll(pfd, 1, waittime_ms)) { |
388 | default: |
389 | /*bb_perror_msg("poll"); - done in safe_poll */ |
390 | goto ret; |
391 | case 0: |
392 | retries--; |
393 | if (retries == 0) { |
394 | bb_error_msg("timeout"); |
395 | goto ret; /* no err packet sent */ |
396 | } |
397 | |
398 | /* exponential backoff with limit */ |
399 | waittime_ms += waittime_ms/2; |
400 | if (waittime_ms > TFTP_MAXTIMEOUT_MS) { |
401 | waittime_ms = TFTP_MAXTIMEOUT_MS; |
402 | } |
403 | |
404 | goto send_again; /* resend last sent pkt */ |
405 | case 1: |
406 | if (!our_lsa) { |
407 | /* tftp (not tftpd!) receiving 1st packet */ |
408 | our_lsa = ((void*)(ptrdiff_t)-1); /* not NULL */ |
409 | len = recvfrom(socket_fd, rbuf, io_bufsize, 0, |
410 | &peer_lsa->u.sa, &peer_lsa->len); |
411 | /* Our first dgram went to port 69 |
412 | * but reply may come from different one. |
413 | * Remember and use this new port (and IP) */ |
414 | if (len >= 0) |
415 | xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len); |
416 | } else { |
417 | /* tftpd, or not the very first packet: |
418 | * socket is connect()ed, can just read from it. */ |
419 | /* Don't full_read()! |
420 | * This is not TCP, one read == one pkt! */ |
421 | len = safe_read(socket_fd, rbuf, io_bufsize); |
422 | } |
423 | if (len < 0) { |
424 | goto send_read_err_pkt; |
425 | } |
426 | if (len < 4) { /* too small? */ |
427 | goto recv_again; |
428 | } |
429 | } |
430 | |
431 | /* Process recv'ed packet */ |
432 | opcode = ntohs( ((uint16_t*)rbuf)[0] ); |
433 | recv_blk = ntohs( ((uint16_t*)rbuf)[1] ); |
434 | #if ENABLE_TFTP_DEBUG |
435 | fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk); |
436 | #endif |
437 | if (opcode == TFTP_ERROR) { |
438 | static const char errcode_str[] ALIGN1 = |
439 | "\0" |
440 | "file not found\0" |
441 | "access violation\0" |
442 | "disk full\0" |
443 | "bad operation\0" |
444 | "unknown transfer id\0" |
445 | "file already exists\0" |
446 | "no such user\0" |
447 | "bad option"; |
448 | |
449 | const char *msg = ""; |
450 | |
451 | if (len > 4 && rbuf[4] != '\0') { |
452 | msg = &rbuf[4]; |
453 | rbuf[io_bufsize - 1] = '\0'; /* paranoia */ |
454 | } else if (recv_blk <= 8) { |
455 | msg = nth_string(errcode_str, recv_blk); |
456 | } |
457 | bb_error_msg("server error: (%u) %s", recv_blk, msg); |
458 | goto ret; |
459 | } |
460 | |
461 | #if ENABLE_FEATURE_TFTP_BLOCKSIZE |
462 | if (want_option_ack) { |
463 | want_option_ack = 0; |
464 | if (opcode == TFTP_OACK) { |
465 | /* server seems to support options */ |
466 | char *res; |
467 | |
468 | res = tftp_get_option("blksize", &rbuf[2], len - 2); |
469 | if (res) { |
470 | blksize = tftp_blksize_check(res, blksize); |
471 | if (blksize < 0) { |
472 | error_pkt_reason = ERR_BAD_OPT; |
473 | goto send_err_pkt; |
474 | } |
475 | io_bufsize = blksize + 4; |
476 | /* Send ACK for OACK ("block" no: 0) */ |
477 | block_nr = 0; |
478 | continue; |
479 | } |
480 | /* rfc2347: |
481 | * "An option not acknowledged by the server |
482 | * must be ignored by the client and server |
483 | * as if it were never requested." */ |
484 | } |
485 | bb_error_msg("server only supports blocksize of 512"); |
486 | blksize = TFTP_BLKSIZE_DEFAULT; |
487 | io_bufsize = TFTP_BLKSIZE_DEFAULT + 4; |
488 | } |
489 | #endif |
490 | /* block_nr is already advanced to next block# we expect |
491 | * to get / block# we are about to send next time */ |
492 | |
493 | if (CMD_GET(option_mask32) && (opcode == TFTP_DATA)) { |
494 | if (recv_blk == block_nr) { |
495 | int sz = full_write(local_fd, &rbuf[4], len - 4); |
496 | if (sz != len - 4) { |
497 | strcpy((char*)error_pkt_str, bb_msg_write_error); |
498 | error_pkt_reason = ERR_WRITE; |
499 | goto send_err_pkt; |
500 | } |
501 | if (sz != blksize) { |
502 | finished = 1; |
503 | } |
504 | continue; /* send ACK */ |
505 | } |
506 | if (recv_blk == (block_nr - 1)) { |
507 | /* Server lost our TFTP_ACK. Resend it */ |
508 | block_nr = recv_blk; |
509 | continue; |
510 | } |
511 | } |
512 | |
513 | if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) { |
514 | /* did peer ACK our last DATA pkt? */ |
515 | if (recv_blk == (uint16_t) (block_nr - 1)) { |
516 | if (finished) |
517 | goto ret; |
518 | continue; /* send next block */ |
519 | } |
520 | } |
521 | /* Awww... recv'd packet is not recognized! */ |
522 | goto recv_again; |
523 | /* why recv_again? - rfc1123 says: |
524 | * "The sender (i.e., the side originating the DATA packets) |
525 | * must never resend the current DATA packet on receipt |
526 | * of a duplicate ACK". |
527 | * DATA pkts are resent ONLY on timeout. |
528 | * Thus "goto send_again" will ba a bad mistake above. |
529 | * See: |
530 | * http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome |
531 | */ |
532 | } /* end of "while (1)" */ |
533 | ret: |
534 | if (ENABLE_FEATURE_CLEAN_UP) { |
535 | close(local_fd); |
536 | close(socket_fd); |
537 | free(xbuf); |
538 | free(rbuf); |
539 | } |
540 | return finished == 0; /* returns 1 on failure */ |
541 | |
542 | send_read_err_pkt: |
543 | strcpy((char*)error_pkt_str, bb_msg_read_error); |
544 | send_err_pkt: |
545 | if (error_pkt_str[0]) |
546 | bb_error_msg((char*)error_pkt_str); |
547 | error_pkt[1] = TFTP_ERROR; |
548 | xsendto(socket_fd, error_pkt, 4 + 1 + strlen((char*)error_pkt_str), |
549 | &peer_lsa->u.sa, peer_lsa->len); |
550 | return EXIT_FAILURE; |
551 | #undef remote_file |
552 | #undef tsize |
553 | } |
554 | |
555 | #if ENABLE_TFTP |
556 | |
557 | int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
558 | int tftp_main(int argc UNUSED_PARAM, char **argv) |
559 | { |
560 | len_and_sockaddr *peer_lsa; |
561 | const char *local_file = NULL; |
562 | const char *remote_file = NULL; |
563 | #if ENABLE_FEATURE_TFTP_BLOCKSIZE |
564 | const char *blksize_str = TFTP_BLKSIZE_DEFAULT_STR; |
565 | int blksize; |
566 | #endif |
567 | int result; |
568 | int port; |
569 | USE_GETPUT(int opt;) |
570 | |
571 | INIT_G(); |
572 | |
573 | /* -p or -g is mandatory, and they are mutually exclusive */ |
574 | opt_complementary = "" USE_FEATURE_TFTP_GET("g:") USE_FEATURE_TFTP_PUT("p:") |
575 | USE_GETPUT("g--p:p--g:"); |
576 | |
577 | USE_GETPUT(opt =) getopt32(argv, |
578 | USE_FEATURE_TFTP_GET("g") USE_FEATURE_TFTP_PUT("p") |
579 | "l:r:" USE_FEATURE_TFTP_BLOCKSIZE("b:"), |
580 | &local_file, &remote_file |
581 | USE_FEATURE_TFTP_BLOCKSIZE(, &blksize_str)); |
582 | argv += optind; |
583 | |
584 | #if ENABLE_FEATURE_TFTP_BLOCKSIZE |
585 | /* Check if the blksize is valid: |
586 | * RFC2348 says between 8 and 65464 */ |
587 | blksize = tftp_blksize_check(blksize_str, 65564); |
588 | if (blksize < 0) { |
589 | //bb_error_msg("bad block size"); |
590 | return EXIT_FAILURE; |
591 | } |
592 | #endif |
593 | |
594 | if (!local_file) |
595 | local_file = remote_file; |
596 | if (!remote_file) |
597 | remote_file = local_file; |
598 | /* Error if filename or host is not known */ |
599 | if (!remote_file || !argv[0]) |
600 | bb_show_usage(); |
601 | |
602 | port = bb_lookup_port(argv[1], "udp", 69); |
603 | peer_lsa = xhost2sockaddr(argv[0], port); |
604 | |
605 | #if ENABLE_TFTP_DEBUG |
606 | fprintf(stderr, "using server '%s', remote_file '%s', local_file '%s'\n", |
607 | xmalloc_sockaddr2dotted(&peer_lsa->u.sa), |
608 | remote_file, local_file); |
609 | #endif |
610 | |
611 | result = tftp_protocol( |
612 | NULL /*our_lsa*/, peer_lsa, |
613 | local_file, remote_file |
614 | USE_FEATURE_TFTP_BLOCKSIZE(USE_TFTPD(, NULL /*tsize*/)) |
615 | USE_FEATURE_TFTP_BLOCKSIZE(, blksize) |
616 | ); |
617 | |
618 | if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) { |
619 | unlink(local_file); |
620 | } |
621 | return result; |
622 | } |
623 | |
624 | #endif /* ENABLE_TFTP */ |
625 | |
626 | #if ENABLE_TFTPD |
627 | |
628 | /* TODO: libbb candidate? */ |
629 | static len_and_sockaddr *get_sock_lsa(int s) |
630 | { |
631 | len_and_sockaddr *lsa; |
632 | socklen_t len = 0; |
633 | |
634 | if (getsockname(s, NULL, &len) != 0) |
635 | return NULL; |
636 | lsa = xzalloc(LSA_LEN_SIZE + len); |
637 | lsa->len = len; |
638 | getsockname(s, &lsa->u.sa, &lsa->len); |
639 | return lsa; |
640 | } |
641 | |
642 | int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
643 | int tftpd_main(int argc UNUSED_PARAM, char **argv) |
644 | { |
645 | len_and_sockaddr *our_lsa; |
646 | len_and_sockaddr *peer_lsa; |
647 | char *local_file, *mode; |
648 | const char *error_msg; |
649 | int opt, result, opcode; |
650 | USE_FEATURE_TFTP_BLOCKSIZE(int blksize = TFTP_BLKSIZE_DEFAULT;) |
651 | USE_FEATURE_TFTP_BLOCKSIZE(char *tsize = NULL;) |
652 | |
653 | INIT_G(); |
654 | |
655 | our_lsa = get_sock_lsa(STDIN_FILENO); |
656 | if (!our_lsa) { |
657 | /* This is confusing: |
658 | *bb_error_msg_and_die("stdin is not a socket"); |
659 | * Better: */ |
660 | bb_show_usage(); |
661 | /* Help text says that tftpd must be used as inetd service, |
662 | * which is by far the most usual cause of get_sock_lsa |
663 | * failure */ |
664 | } |
665 | peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len); |
666 | peer_lsa->len = our_lsa->len; |
667 | |
668 | /* Shifting to not collide with TFTP_OPTs */ |
669 | opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:", &user_opt) << 8); |
670 | argv += optind; |
671 | if (argv[0]) |
672 | xchdir(argv[0]); |
673 | |
674 | result = recv_from_to(STDIN_FILENO, block_buf, sizeof(block_buf), |
675 | 0 /* flags */, |
676 | &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len); |
677 | |
678 | error_msg = "malformed packet"; |
679 | opcode = ntohs(*(uint16_t*)block_buf); |
680 | if (result < 4 || result >= sizeof(block_buf) |
681 | || block_buf[result-1] != '\0' |
682 | || (USE_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */ |
683 | USE_GETPUT(&&) |
684 | USE_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */ |
685 | ) |
686 | ) { |
687 | goto err; |
688 | } |
689 | local_file = block_buf + 2; |
690 | if (local_file[0] == '.' || strstr(local_file, "/.")) { |
691 | error_msg = "dot in file name"; |
692 | goto err; |
693 | } |
694 | mode = local_file + strlen(local_file) + 1; |
695 | if (mode >= block_buf + result || strcmp(mode, "octet") != 0) { |
696 | goto err; |
697 | } |
698 | #if ENABLE_FEATURE_TFTP_BLOCKSIZE |
699 | { |
700 | char *res; |
701 | char *opt_str = mode + sizeof("octet"); |
702 | int opt_len = block_buf + result - opt_str; |
703 | if (opt_len > 0) { |
704 | res = tftp_get_option("blksize", opt_str, opt_len); |
705 | if (res) { |
706 | blksize = tftp_blksize_check(res, 65564); |
707 | if (blksize < 0) { |
708 | error_pkt_reason = ERR_BAD_OPT; |
709 | /* will just send error pkt */ |
710 | goto do_proto; |
711 | } |
712 | } |
713 | /* did client ask us about file size? */ |
714 | tsize = tftp_get_option("tsize", opt_str, opt_len); |
715 | } |
716 | } |
717 | #endif |
718 | |
719 | if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) { |
720 | if (opt & TFTPD_OPT_r) { |
721 | /* This would mean "disk full" - not true */ |
722 | /*error_pkt_reason = ERR_WRITE;*/ |
723 | error_msg = bb_msg_write_error; |
724 | goto err; |
725 | } |
726 | USE_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */ |
727 | } else { |
728 | USE_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */ |
729 | } |
730 | |
731 | /* NB: if error_pkt_str or error_pkt_reason is set up, |
732 | * tftp_protocol() just sends one error pkt and returns */ |
733 | |
734 | do_proto: |
735 | close(STDIN_FILENO); /* close old, possibly wildcard socket */ |
736 | /* tftp_protocol() will create new one, bound to particular local IP */ |
737 | result = tftp_protocol( |
738 | our_lsa, peer_lsa, |
739 | local_file USE_TFTP(, NULL /*remote_file*/) |
740 | USE_FEATURE_TFTP_BLOCKSIZE(, tsize) |
741 | USE_FEATURE_TFTP_BLOCKSIZE(, blksize) |
742 | ); |
743 | |
744 | return result; |
745 | err: |
746 | strcpy((char*)error_pkt_str, error_msg); |
747 | goto do_proto; |
748 | } |
749 | |
750 | #endif /* ENABLE_TFTPD */ |
751 | |
752 | #endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */ |