1 /* vi: set sw=4 ts=4: */
3 * A simple tftp client/server for busybox.
4 * Tries to follow RFC1350.
5 * Only "octet" mode supported.
6 * Optional blocksize negotiation (RFC2347 + RFC2348)
8 * Copyright (C) 2001 Magnus Damm <damm@opensource.se>
10 * Parts of the code based on:
12 * atftp: Copyright (C) 2000 Jean-Pierre Lefebvre <helix@step.polymtl.ca>
13 * and Remi Lefebvre <remi@debian.org>
15 * utftp: Copyright (C) 1999 Uwe Ohse <uwe@ohse.de>
17 * tftpd added by Denys Vlasenko & Vladimir Dronnikov
19 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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"
27 //usage: "\n -l FILE Local FILE"
28 //usage: "\n -r FILE Remote FILE"
29 //usage: IF_FEATURE_TFTP_GET(
30 //usage: "\n -g Get file"
32 //usage: IF_FEATURE_TFTP_PUT(
33 //usage: "\n -p Put file"
35 //usage: IF_FEATURE_TFTP_BLOCKSIZE(
36 //usage: "\n -b SIZE Transfer blocks of SIZE octets"
39 //usage:#define tftpd_trivial_usage
40 //usage: "[-cr] [-u USER] [DIR]"
41 //usage:#define tftpd_full_usage "\n\n"
42 //usage: "Transfer a file on tftp client's request\n"
44 //usage: "tftpd should be used as an inetd service.\n"
45 //usage: "tftpd's line for inetd.conf:\n"
46 //usage: " 69 dgram udp nowait root tftpd tftpd -l /files/to/serve\n"
47 //usage: "It also can be ran from udpsvd:\n"
48 //usage: " udpsvd -vE 0.0.0.0 69 tftpd /files/to/serve\n"
50 //usage: "\n -r Prohibit upload"
51 //usage: "\n -c Allow file creation via upload"
52 //usage: "\n -u Access files as USER"
53 //usage: "\n -l Log to syslog (inetd mode requires this)"
58 #if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT
60 #define TFTP_BLKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */
61 #define TFTP_BLKSIZE_DEFAULT_STR "512"
62 /* Was 50 ms but users asked to bump it up a bit */
63 #define TFTP_TIMEOUT_MS 100
64 #define TFTP_MAXTIMEOUT_MS 2000
65 #define TFTP_NUM_RETRIES 12 /* number of backed-off retries */
67 /* opcodes we support */
75 /* error codes sent over network (we use only 0, 1, 3 and 8) */
76 /* generic (error message is included in the packet) */
80 /* disk full or allocation exceeded */
85 #define ERR_BAD_USER 7
88 /* masks coming from getopt32 */
90 TFTP_OPT_GET = (1 << 0),
91 TFTP_OPT_PUT = (1 << 1),
92 /* pseudo option: if set, it's tftpd */
93 TFTPD_OPT = (1 << 7) * ENABLE_TFTPD,
94 TFTPD_OPT_r = (1 << 8) * ENABLE_TFTPD,
95 TFTPD_OPT_c = (1 << 9) * ENABLE_TFTPD,
96 TFTPD_OPT_u = (1 << 10) * ENABLE_TFTPD,
97 TFTPD_OPT_l = (1 << 11) * ENABLE_TFTPD,
100 #if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT
101 #define IF_GETPUT(...)
102 #define CMD_GET(cmd) 1
103 #define CMD_PUT(cmd) 0
104 #elif !ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT
105 #define IF_GETPUT(...)
106 #define CMD_GET(cmd) 0
107 #define CMD_PUT(cmd) 1
109 #define IF_GETPUT(...) __VA_ARGS__
110 #define CMD_GET(cmd) ((cmd) & TFTP_OPT_GET)
111 #define CMD_PUT(cmd) ((cmd) & TFTP_OPT_PUT)
113 /* NB: in the code below
114 * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive
119 /* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */
120 uint8_t error_pkt[4 + 32];
122 /* used in tftpd_main(), a bit big for stack: */
123 char block_buf[TFTP_BLKSIZE_DEFAULT];
124 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
131 #define G (*(struct globals*)&bb_common_bufsiz1)
132 struct BUG_G_too_big {
133 char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
135 #define block_buf (G.block_buf )
136 #define user_opt (G.user_opt )
137 #define error_pkt (G.error_pkt )
138 #define INIT_G() do { } while (0)
140 #define error_pkt_reason (error_pkt[3])
141 #define error_pkt_str (error_pkt + 4)
143 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
144 static void tftp_progress_update(void)
146 bb_progress_update(&G.pmt, 0, G.pos, G.size);
148 static void tftp_progress_init(void)
150 bb_progress_init(&G.pmt, G.file);
151 tftp_progress_update();
153 static void tftp_progress_done(void)
155 if (is_bb_progress_inited(&G.pmt)) {
156 tftp_progress_update();
157 bb_putchar_stderr('\n');
158 bb_progress_free(&G.pmt);
162 # define tftp_progress_init() ((void)0)
163 # define tftp_progress_done() ((void)0)
166 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
168 static int tftp_blksize_check(const char *blksize_str, int maxsize)
170 /* Check if the blksize is valid:
171 * RFC2348 says between 8 and 65464,
172 * but our implementation makes it impossible
173 * to use blksizes smaller than 22 octets. */
174 unsigned blksize = bb_strtou(blksize_str, NULL, 10);
176 || (blksize < 24) || (blksize > maxsize)
178 bb_error_msg("bad blocksize '%s'", blksize_str);
181 # if ENABLE_TFTP_DEBUG
182 bb_error_msg("using blksize %u", blksize);
187 static char *tftp_get_option(const char *option, char *buf, int len)
194 * "opt_name<NUL>opt_val<NUL>opt_name2<NUL>opt_val2<NUL>..." */
197 /* Make sure options are terminated correctly */
198 for (k = 0; k < len; k++) {
199 if (buf[k] == '\0') {
205 if (opt_val == 0) { /* it's "name" part */
206 if (strcasecmp(buf, option) == 0) {
209 } else if (opt_found) {
224 static int tftp_protocol(
225 /* NULL if tftp, !NULL if tftpd: */
226 len_and_sockaddr *our_lsa,
227 len_and_sockaddr *peer_lsa,
228 const char *local_file
229 IF_TFTP(, const char *remote_file)
231 # define remote_file NULL
233 /* 1 for tftp; 1/0 for tftpd depending whether client asked about it: */
234 IF_FEATURE_TFTP_BLOCKSIZE(, int want_transfer_size)
235 IF_FEATURE_TFTP_BLOCKSIZE(, int blksize))
237 #if !ENABLE_FEATURE_TFTP_BLOCKSIZE
238 enum { blksize = TFTP_BLKSIZE_DEFAULT };
241 struct pollfd pfd[1];
242 #define socket_fd (pfd[0].fd)
245 IF_FEATURE_TFTP_BLOCKSIZE(smallint expect_OACK = 0;)
246 smallint finished = 0;
250 int open_mode, local_fd;
251 int retries, waittime_ms;
252 int io_bufsize = blksize + 4;
254 /* Can't use RESERVE_CONFIG_BUFFER here since the allocation
255 * size varies meaning BUFFERS_GO_ON_STACK would fail.
257 * We must keep the transmit and receive buffers separate
258 * in case we rcv a garbage pkt - we need to rexmit the last pkt.
260 char *xbuf = xmalloc(io_bufsize);
261 char *rbuf = xmalloc(io_bufsize);
263 socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0);
264 setsockopt_reuseaddr(socket_fd);
266 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
267 /* Create a socket which is:
268 * 1. bound to IP:port peer sent 1st datagram to,
269 * 2. connected to peer's IP:port
270 * This way we will answer from the IP:port peer
271 * expects, will not get any other packets on
272 * the socket, and also plain read/write will work. */
273 xbind(socket_fd, &our_lsa->u.sa, our_lsa->len);
274 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
276 /* Is there an error already? Send pkt and bail out */
277 if (error_pkt_reason || error_pkt_str[0])
281 struct passwd *pw = xgetpwnam(user_opt);
282 change_identity(pw); /* initgroups, setgid, setuid */
286 /* Prepare open mode */
287 if (CMD_PUT(option_mask32)) {
288 open_mode = O_RDONLY;
290 open_mode = O_WRONLY | O_TRUNC | O_CREAT;
292 if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) {
293 /* tftpd without -c */
294 open_mode = O_WRONLY | O_TRUNC;
299 /* Examples of network traffic.
300 * Note two cases when ACKs with block# of 0 are sent.
302 * Download without options:
303 * tftp -> "\0\1FILENAME\0octet\0"
304 * "\0\3\0\1FILEDATA..." <- tftpd
307 * Download with option of blksize 16384:
308 * tftp -> "\0\1FILENAME\0octet\0blksize\00016384\0"
309 * "\0\6blksize\00016384\0" <- tftpd
311 * "\0\3\0\1FILEDATA..." <- tftpd
314 * Upload without options:
315 * tftp -> "\0\2FILENAME\0octet\0"
316 * "\0\4\0\0" <- tftpd
317 * tftp -> "\0\3\0\1FILEDATA..."
318 * "\0\4\0\1" <- tftpd
320 * Upload with option of blksize 16384:
321 * tftp -> "\0\2FILENAME\0octet\0blksize\00016384\0"
322 * "\0\6blksize\00016384\0" <- tftpd
323 * tftp -> "\0\3\0\1FILEDATA..."
324 * "\0\4\0\1" <- tftpd
330 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
331 /* Open file (must be after changing user) */
332 local_fd = open(local_file, open_mode, 0666);
334 error_pkt_reason = ERR_NOFILE;
335 strcpy((char*)error_pkt_str, "can't open file");
338 /* gcc 4.3.1 would NOT optimize it out as it should! */
339 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
340 if (blksize != TFTP_BLKSIZE_DEFAULT || want_transfer_size) {
341 /* Create and send OACK packet. */
342 /* For the download case, block_nr is still 1 -
343 * we expect 1st ACK from peer to be for (block_nr-1),
344 * that is, for "block 0" which is our OACK pkt */
346 goto add_blksize_opt;
349 if (CMD_GET(option_mask32)) {
350 /* It's upload and we don't send OACK.
351 * We must ACK 1st packet (with filename)
352 * as if it is "block 0" */
357 /* Open file (must be after changing user) */
358 local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO;
359 if (NOT_LONE_DASH(local_file))
360 local_fd = xopen(local_file, open_mode);
361 /* Removing #if, or using if() statement instead of #if may lead to
362 * "warning: null argument where non-null required": */
366 /* We can't (and don't really need to) bind the socket:
367 * we don't know from which local IP datagrams will be sent,
368 * but kernel will pick the same IP every time (unless routing
369 * table is changed), thus peer will see dgrams consistently
370 * coming from the same IP.
371 * We would like to connect the socket, but since peer's
372 * UDP code can be less perfect than ours, _peer's_ IP:port
373 * in replies may differ from IP:port we used to send
374 * our first packet. We can connect() only when we get
379 if (CMD_GET(option_mask32)) {
382 /* add filename and mode */
383 /* fill in packet if the filename fits into xbuf */
384 len = strlen(remote_file) + 1;
385 if (2 + len + sizeof("octet") >= io_bufsize) {
386 bb_error_msg("remote filename is too long");
389 strcpy(cp, remote_file);
391 /* add "mode" part of the packet */
393 cp += sizeof("octet");
395 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
396 if (blksize == TFTP_BLKSIZE_DEFAULT && !want_transfer_size)
399 /* Need to add option to pkt */
400 if ((&xbuf[io_bufsize - 1] - cp) < sizeof("blksize NNNNN tsize ") + sizeof(off_t)*3) {
401 bb_error_msg("remote filename is too long");
406 #endif /* ENABLE_TFTP */
408 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
410 if (blksize != TFTP_BLKSIZE_DEFAULT) {
411 /* add "blksize", <nul>, blksize, <nul> */
412 strcpy(cp, "blksize");
413 cp += sizeof("blksize");
414 cp += snprintf(cp, 6, "%d", blksize) + 1;
416 if (want_transfer_size) {
417 /* add "tsize", <nul>, size, <nul> (see RFC2349) */
418 /* if tftp and downloading, we send "0" (since we opened local_fd with O_TRUNC)
419 * and this makes server to send "tsize" option with the size */
420 /* if tftp and uploading, we send file size (maybe dont, to not confuse old servers???) */
421 /* if tftpd and downloading, we are answering to client's request */
422 /* if tftpd and uploading: !want_transfer_size, this code is not executed */
425 cp += sizeof("tsize");
427 fstat(local_fd, &st);
428 cp += sprintf(cp, "%"OFF_FMT"u", (off_t)st.st_size) + 1;
429 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
430 /* Save for progress bar. If 0 (tftp downloading),
431 * we look at server's reply later */
433 if (remote_file && st.st_size)
434 tftp_progress_init();
438 /* First packet is built, so skip packet generation */
442 /* Using mostly goto's - continue/break will be less clear
443 * in where we actually jump to */
445 /* Build ACK or DATA */
447 *((uint16_t*)cp) = htons(block_nr);
451 if (CMD_PUT(option_mask32)) {
453 len = full_read(local_fd, cp, blksize);
455 goto send_read_err_pkt;
457 if (len != blksize) {
461 IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += len;)
465 *((uint16_t*)xbuf) = htons(opcode); /* fill in opcode part */
466 send_len = cp - xbuf;
467 /* NB: send_len value is preserved in code below
468 * for potential resend */
470 retries = TFTP_NUM_RETRIES; /* re-initialize */
471 waittime_ms = TFTP_TIMEOUT_MS;
474 #if ENABLE_TFTP_DEBUG
475 fprintf(stderr, "sending %u bytes\n", send_len);
476 for (cp = xbuf; cp < &xbuf[send_len]; cp++)
477 fprintf(stderr, "%02x ", (unsigned char) *cp);
478 fprintf(stderr, "\n");
480 xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len);
482 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
483 if (is_bb_progress_inited(&G.pmt))
484 tftp_progress_update();
486 /* Was it final ACK? then exit */
487 if (finished && (opcode == TFTP_ACK))
492 /*pfd[0].fd = socket_fd;*/
493 pfd[0].events = POLLIN;
494 switch (safe_poll(pfd, 1, waittime_ms)) {
496 /*bb_perror_msg("poll"); - done in safe_poll */
501 tftp_progress_done();
502 bb_error_msg("timeout");
503 goto ret; /* no err packet sent */
506 /* exponential backoff with limit */
507 waittime_ms += waittime_ms/2;
508 if (waittime_ms > TFTP_MAXTIMEOUT_MS) {
509 waittime_ms = TFTP_MAXTIMEOUT_MS;
512 goto send_again; /* resend last sent pkt */
515 /* tftp (not tftpd!) receiving 1st packet */
516 our_lsa = ((void*)(ptrdiff_t)-1); /* not NULL */
517 len = recvfrom(socket_fd, rbuf, io_bufsize, 0,
518 &peer_lsa->u.sa, &peer_lsa->len);
519 /* Our first dgram went to port 69
520 * but reply may come from different one.
521 * Remember and use this new port (and IP) */
523 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
525 /* tftpd, or not the very first packet:
526 * socket is connect()ed, can just read from it. */
527 /* Don't full_read()!
528 * This is not TCP, one read == one pkt! */
529 len = safe_read(socket_fd, rbuf, io_bufsize);
532 goto send_read_err_pkt;
534 if (len < 4) { /* too small? */
539 /* Process recv'ed packet */
540 opcode = ntohs( ((uint16_t*)rbuf)[0] );
541 recv_blk = ntohs( ((uint16_t*)rbuf)[1] );
542 #if ENABLE_TFTP_DEBUG
543 fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk);
545 if (opcode == TFTP_ERROR) {
546 static const char errcode_str[] ALIGN1 =
552 "unknown transfer id\0"
553 "file already exists\0"
557 const char *msg = "";
559 if (len > 4 && rbuf[4] != '\0') {
561 rbuf[io_bufsize - 1] = '\0'; /* paranoia */
562 } else if (recv_blk <= 8) {
563 msg = nth_string(errcode_str, recv_blk);
565 bb_error_msg("server error: (%u) %s", recv_blk, msg);
569 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
572 if (opcode == TFTP_OACK) {
573 /* server seems to support options */
576 res = tftp_get_option("blksize", &rbuf[2], len - 2);
578 blksize = tftp_blksize_check(res, blksize);
580 error_pkt_reason = ERR_BAD_OPT;
583 io_bufsize = blksize + 4;
585 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
586 if (remote_file && G.size == 0) { /* if we don't know it yet */
587 res = tftp_get_option("tsize", &rbuf[2], len - 2);
589 G.size = bb_strtoull(res, NULL, 10);
591 tftp_progress_init();
595 if (CMD_GET(option_mask32)) {
596 /* We'll send ACK for OACK,
597 * such ACK has "block no" of 0 */
603 * "An option not acknowledged by the server
604 * must be ignored by the client and server
605 * as if it were never requested." */
606 if (blksize != TFTP_BLKSIZE_DEFAULT)
607 bb_error_msg("falling back to blocksize "TFTP_BLKSIZE_DEFAULT_STR);
608 blksize = TFTP_BLKSIZE_DEFAULT;
609 io_bufsize = TFTP_BLKSIZE_DEFAULT + 4;
612 /* block_nr is already advanced to next block# we expect
613 * to get / block# we are about to send next time */
615 if (CMD_GET(option_mask32) && (opcode == TFTP_DATA)) {
616 if (recv_blk == block_nr) {
617 int sz = full_write(local_fd, &rbuf[4], len - 4);
619 strcpy((char*)error_pkt_str, bb_msg_write_error);
620 error_pkt_reason = ERR_WRITE;
626 IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += sz;)
627 continue; /* send ACK */
629 /* Disabled to cope with servers with Sorcerer's Apprentice Syndrome */
631 if (recv_blk == (block_nr - 1)) {
632 /* Server lost our TFTP_ACK. Resend it */
639 if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) {
640 /* did peer ACK our last DATA pkt? */
641 if (recv_blk == (uint16_t) (block_nr - 1)) {
644 continue; /* send next block */
647 /* Awww... recv'd packet is not recognized! */
649 /* why recv_again? - rfc1123 says:
650 * "The sender (i.e., the side originating the DATA packets)
651 * must never resend the current DATA packet on receipt
652 * of a duplicate ACK".
653 * DATA pkts are resent ONLY on timeout.
654 * Thus "goto send_again" will ba a bad mistake above.
656 * http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome
658 } /* end of "while (1)" */
660 if (ENABLE_FEATURE_CLEAN_UP) {
666 return finished == 0; /* returns 1 on failure */
669 strcpy((char*)error_pkt_str, bb_msg_read_error);
671 if (error_pkt_str[0])
672 bb_error_msg("%s", (char*)error_pkt_str);
673 error_pkt[1] = TFTP_ERROR;
674 xsendto(socket_fd, error_pkt, 4 + 1 + strlen((char*)error_pkt_str),
675 &peer_lsa->u.sa, peer_lsa->len);
682 int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
683 int tftp_main(int argc UNUSED_PARAM, char **argv)
685 len_and_sockaddr *peer_lsa;
686 const char *local_file = NULL;
687 const char *remote_file = NULL;
688 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
689 const char *blksize_str = TFTP_BLKSIZE_DEFAULT_STR;
698 /* -p or -g is mandatory, and they are mutually exclusive */
699 opt_complementary = "" IF_FEATURE_TFTP_GET("g:") IF_FEATURE_TFTP_PUT("p:")
700 IF_GETPUT("g--p:p--g:");
702 IF_GETPUT(opt =) getopt32(argv,
703 IF_FEATURE_TFTP_GET("g") IF_FEATURE_TFTP_PUT("p")
704 "l:r:" IF_FEATURE_TFTP_BLOCKSIZE("b:"),
705 &local_file, &remote_file
706 IF_FEATURE_TFTP_BLOCKSIZE(, &blksize_str));
709 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
710 /* Check if the blksize is valid:
711 * RFC2348 says between 8 and 65464 */
712 blksize = tftp_blksize_check(blksize_str, 65564);
714 //bb_error_msg("bad block size");
721 const char *slash = strrchr(remote_file, '/');
722 local_file = slash ? slash + 1 : remote_file;
725 remote_file = local_file;
728 /* Error if filename or host is not known */
729 if (!remote_file || !argv[0])
732 port = bb_lookup_port(argv[1], "udp", 69);
733 peer_lsa = xhost2sockaddr(argv[0], port);
735 # if ENABLE_TFTP_DEBUG
736 fprintf(stderr, "using server '%s', remote_file '%s', local_file '%s'\n",
737 xmalloc_sockaddr2dotted(&peer_lsa->u.sa),
738 remote_file, local_file);
741 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
742 G.file = remote_file;
744 result = tftp_protocol(
745 NULL /*our_lsa*/, peer_lsa,
746 local_file, remote_file
747 IF_FEATURE_TFTP_BLOCKSIZE(, 1 /* want_transfer_size */)
748 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
750 tftp_progress_done();
752 if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) {
758 #endif /* ENABLE_TFTP */
761 int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
762 int tftpd_main(int argc UNUSED_PARAM, char **argv)
764 len_and_sockaddr *our_lsa;
765 len_and_sockaddr *peer_lsa;
766 char *local_file, *mode;
767 const char *error_msg;
768 int opt, result, opcode;
769 IF_FEATURE_TFTP_BLOCKSIZE(int blksize = TFTP_BLKSIZE_DEFAULT;)
770 IF_FEATURE_TFTP_BLOCKSIZE(int want_transfer_size = 0;)
774 our_lsa = get_sock_lsa(STDIN_FILENO);
776 /* This is confusing:
777 *bb_error_msg_and_die("stdin is not a socket");
780 /* Help text says that tftpd must be used as inetd service,
781 * which is by far the most usual cause of get_sock_lsa
784 peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len);
785 peer_lsa->len = our_lsa->len;
787 /* Shifting to not collide with TFTP_OPTs */
788 opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:l", &user_opt) << 8);
790 if (opt & TFTPD_OPT_l) {
791 openlog(applet_name, LOG_PID, LOG_DAEMON);
792 logmode = LOGMODE_SYSLOG;
797 result = recv_from_to(STDIN_FILENO, block_buf, sizeof(block_buf),
799 &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len);
801 error_msg = "malformed packet";
802 opcode = ntohs(*(uint16_t*)block_buf);
803 if (result < 4 || result >= sizeof(block_buf)
804 || block_buf[result-1] != '\0'
805 || (IF_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */
807 IF_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */
812 local_file = block_buf + 2;
813 if (local_file[0] == '.' || strstr(local_file, "/.")) {
814 error_msg = "dot in file name";
817 mode = local_file + strlen(local_file) + 1;
818 if (mode >= block_buf + result || strcmp(mode, "octet") != 0) {
821 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
824 char *opt_str = mode + sizeof("octet");
825 int opt_len = block_buf + result - opt_str;
827 res = tftp_get_option("blksize", opt_str, opt_len);
829 blksize = tftp_blksize_check(res, 65564);
831 error_pkt_reason = ERR_BAD_OPT;
832 /* will just send error pkt */
836 if (opcode != TFTP_WRQ /* download? */
837 /* did client ask us about file size? */
838 && tftp_get_option("tsize", opt_str, opt_len)
840 want_transfer_size = 1;
846 if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) {
847 if (opt & TFTPD_OPT_r) {
848 /* This would mean "disk full" - not true */
849 /*error_pkt_reason = ERR_WRITE;*/
850 error_msg = bb_msg_write_error;
853 IF_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */
855 IF_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */
858 /* NB: if error_pkt_str or error_pkt_reason is set up,
859 * tftp_protocol() just sends one error pkt and returns */
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(
866 local_file IF_TFTP(, NULL /*remote_file*/)
867 IF_FEATURE_TFTP_BLOCKSIZE(, want_transfer_size)
868 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
873 strcpy((char*)error_pkt_str, error_msg);
877 #endif /* ENABLE_TFTPD */
879 #endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */