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 /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"
56 #if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT
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 */
65 /* opcodes we support */
73 /* error codes sent over network (we use only 0, 1, 3 and 8) */
74 /* generic (error message is included in the packet) */
78 /* disk full or allocation exceeded */
83 #define ERR_BAD_USER 7
86 /* masks coming from getopt32 */
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,
97 #if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT
98 #define IF_GETPUT(...)
99 #define CMD_GET(cmd) 1
100 #define CMD_PUT(cmd) 0
101 #elif !ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT
102 #define IF_GETPUT(...)
103 #define CMD_GET(cmd) 0
104 #define CMD_PUT(cmd) 1
106 #define IF_GETPUT(...) __VA_ARGS__
107 #define CMD_GET(cmd) ((cmd) & TFTP_OPT_GET)
108 #define CMD_PUT(cmd) ((cmd) & TFTP_OPT_PUT)
110 /* NB: in the code below
111 * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive
116 /* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */
117 uint8_t error_pkt[4 + 32];
119 /* used in tftpd_main(), a bit big for stack: */
120 char block_buf[TFTP_BLKSIZE_DEFAULT];
121 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
128 #define G (*(struct globals*)&bb_common_bufsiz1)
129 struct BUG_G_too_big {
130 char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
132 #define block_buf (G.block_buf )
133 #define user_opt (G.user_opt )
134 #define error_pkt (G.error_pkt )
135 #define INIT_G() do { } while (0)
137 #define error_pkt_reason (error_pkt[3])
138 #define error_pkt_str (error_pkt + 4)
140 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
141 static void tftp_progress_update(void)
143 bb_progress_update(&G.pmt, 0, G.pos, G.size);
145 static void tftp_progress_init(void)
147 bb_progress_init(&G.pmt, G.file);
148 tftp_progress_update();
150 static void tftp_progress_done(void)
152 if (is_bb_progress_inited(&G.pmt)) {
153 tftp_progress_update();
154 bb_putchar_stderr('\n');
155 bb_progress_free(&G.pmt);
159 # define tftp_progress_init() ((void)0)
160 # define tftp_progress_done() ((void)0)
163 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
165 static int tftp_blksize_check(const char *blksize_str, int maxsize)
167 /* Check if the blksize is valid:
168 * RFC2348 says between 8 and 65464,
169 * but our implementation makes it impossible
170 * to use blksizes smaller than 22 octets. */
171 unsigned blksize = bb_strtou(blksize_str, NULL, 10);
173 || (blksize < 24) || (blksize > maxsize)
175 bb_error_msg("bad blocksize '%s'", blksize_str);
178 # if ENABLE_TFTP_DEBUG
179 bb_error_msg("using blksize %u", blksize);
184 static char *tftp_get_option(const char *option, char *buf, int len)
191 * "opt_name<NUL>opt_val<NUL>opt_name2<NUL>opt_val2<NUL>..." */
194 /* Make sure options are terminated correctly */
195 for (k = 0; k < len; k++) {
196 if (buf[k] == '\0') {
202 if (opt_val == 0) { /* it's "name" part */
203 if (strcasecmp(buf, option) == 0) {
206 } else if (opt_found) {
221 static int tftp_protocol(
222 /* NULL if tftp, !NULL if tftpd: */
223 len_and_sockaddr *our_lsa,
224 len_and_sockaddr *peer_lsa,
225 const char *local_file
226 IF_TFTP(, const char *remote_file)
228 # define remote_file NULL
230 /* 1 for tftp; 1/0 for tftpd depending whether client asked about it: */
231 IF_FEATURE_TFTP_BLOCKSIZE(, int want_transfer_size)
232 IF_FEATURE_TFTP_BLOCKSIZE(, int blksize))
234 #if !ENABLE_FEATURE_TFTP_BLOCKSIZE
235 enum { blksize = TFTP_BLKSIZE_DEFAULT };
238 struct pollfd pfd[1];
239 #define socket_fd (pfd[0].fd)
242 IF_FEATURE_TFTP_BLOCKSIZE(smallint expect_OACK = 0;)
243 smallint finished = 0;
247 int open_mode, local_fd;
248 int retries, waittime_ms;
249 int io_bufsize = blksize + 4;
251 /* Can't use RESERVE_CONFIG_BUFFER here since the allocation
252 * size varies meaning BUFFERS_GO_ON_STACK would fail.
254 * We must keep the transmit and receive buffers separate
255 * in case we rcv a garbage pkt - we need to rexmit the last pkt.
257 char *xbuf = xmalloc(io_bufsize);
258 char *rbuf = xmalloc(io_bufsize);
260 socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0);
261 setsockopt_reuseaddr(socket_fd);
263 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
264 /* Create a socket which is:
265 * 1. bound to IP:port peer sent 1st datagram to,
266 * 2. connected to peer's IP:port
267 * This way we will answer from the IP:port peer
268 * expects, will not get any other packets on
269 * the socket, and also plain read/write will work. */
270 xbind(socket_fd, &our_lsa->u.sa, our_lsa->len);
271 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
273 /* Is there an error already? Send pkt and bail out */
274 if (error_pkt_reason || error_pkt_str[0])
278 struct passwd *pw = xgetpwnam(user_opt);
279 change_identity(pw); /* initgroups, setgid, setuid */
283 /* Prepare open mode */
284 if (CMD_PUT(option_mask32)) {
285 open_mode = O_RDONLY;
287 open_mode = O_WRONLY | O_TRUNC | O_CREAT;
289 if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) {
290 /* tftpd without -c */
291 open_mode = O_WRONLY | O_TRUNC;
296 /* Examples of network traffic.
297 * Note two cases when ACKs with block# of 0 are sent.
299 * Download without options:
300 * tftp -> "\0\1FILENAME\0octet\0"
301 * "\0\3\0\1FILEDATA..." <- tftpd
304 * Download with option of blksize 16384:
305 * tftp -> "\0\1FILENAME\0octet\0blksize\00016384\0"
306 * "\0\6blksize\00016384\0" <- tftpd
308 * "\0\3\0\1FILEDATA..." <- tftpd
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
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
327 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
328 /* Open file (must be after changing user) */
329 local_fd = open(local_file, open_mode, 0666);
331 error_pkt_reason = ERR_NOFILE;
332 strcpy((char*)error_pkt_str, "can't open file");
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 */
343 goto add_blksize_opt;
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" */
354 /* Open file (must be after changing user) */
355 local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO;
356 if (NOT_LONE_DASH(local_file))
357 local_fd = xopen(local_file, open_mode);
358 /* Removing #if, or using if() statement instead of #if may lead to
359 * "warning: null argument where non-null required": */
363 /* We can't (and don't really need to) bind the socket:
364 * we don't know from which local IP datagrams will be sent,
365 * but kernel will pick the same IP every time (unless routing
366 * table is changed), thus peer will see dgrams consistently
367 * coming from the same IP.
368 * We would like to connect the socket, but since peer's
369 * UDP code can be less perfect than ours, _peer's_ IP:port
370 * in replies may differ from IP:port we used to send
371 * our first packet. We can connect() only when we get
376 if (CMD_GET(option_mask32)) {
379 /* add filename and mode */
380 /* fill in packet if the filename fits into xbuf */
381 len = strlen(remote_file) + 1;
382 if (2 + len + sizeof("octet") >= io_bufsize) {
383 bb_error_msg("remote filename is too long");
386 strcpy(cp, remote_file);
388 /* add "mode" part of the packet */
390 cp += sizeof("octet");
392 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
393 if (blksize == TFTP_BLKSIZE_DEFAULT && !want_transfer_size)
396 /* Need to add option to pkt */
397 if ((&xbuf[io_bufsize - 1] - cp) < sizeof("blksize NNNNN tsize ") + sizeof(off_t)*3) {
398 bb_error_msg("remote filename is too long");
403 #endif /* ENABLE_TFTP */
405 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
407 if (blksize != TFTP_BLKSIZE_DEFAULT) {
408 /* add "blksize", <nul>, blksize, <nul> */
409 strcpy(cp, "blksize");
410 cp += sizeof("blksize");
411 cp += snprintf(cp, 6, "%d", blksize) + 1;
413 if (want_transfer_size) {
414 /* add "tsize", <nul>, size, <nul> (see RFC2349) */
415 /* if tftp and downloading, we send "0" (since we opened local_fd with O_TRUNC)
416 * and this makes server to send "tsize" option with the size */
417 /* if tftp and uploading, we send file size (maybe dont, to not confuse old servers???) */
418 /* if tftpd and downloading, we are answering to client's request */
419 /* if tftpd and uploading: !want_transfer_size, this code is not executed */
422 cp += sizeof("tsize");
424 fstat(local_fd, &st);
425 cp += sprintf(cp, "%"OFF_FMT"u", (off_t)st.st_size) + 1;
426 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
427 /* Save for progress bar. If 0 (tftp downloading),
428 * we look at server's reply later */
430 if (remote_file && st.st_size)
431 tftp_progress_init();
435 /* First packet is built, so skip packet generation */
439 /* Using mostly goto's - continue/break will be less clear
440 * in where we actually jump to */
442 /* Build ACK or DATA */
444 *((uint16_t*)cp) = htons(block_nr);
448 if (CMD_PUT(option_mask32)) {
450 len = full_read(local_fd, cp, blksize);
452 goto send_read_err_pkt;
454 if (len != blksize) {
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 */
466 retries = TFTP_NUM_RETRIES; /* re-initialize */
467 waittime_ms = TFTP_TIMEOUT_MS;
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");
476 xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len);
478 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
479 if (ENABLE_TFTP && remote_file) /* tftp */
480 G.pos = (block_nr - 1) * (uoff_t)blksize;
481 if (is_bb_progress_inited(&G.pmt))
482 tftp_progress_update();
484 /* Was it final ACK? then exit */
485 if (finished && (opcode == TFTP_ACK))
490 /*pfd[0].fd = socket_fd;*/
491 pfd[0].events = POLLIN;
492 switch (safe_poll(pfd, 1, waittime_ms)) {
494 /*bb_perror_msg("poll"); - done in safe_poll */
499 tftp_progress_done();
500 bb_error_msg("timeout");
501 goto ret; /* no err packet sent */
504 /* exponential backoff with limit */
505 waittime_ms += waittime_ms/2;
506 if (waittime_ms > TFTP_MAXTIMEOUT_MS) {
507 waittime_ms = TFTP_MAXTIMEOUT_MS;
510 goto send_again; /* resend last sent pkt */
513 /* tftp (not tftpd!) receiving 1st packet */
514 our_lsa = ((void*)(ptrdiff_t)-1); /* not NULL */
515 len = recvfrom(socket_fd, rbuf, io_bufsize, 0,
516 &peer_lsa->u.sa, &peer_lsa->len);
517 /* Our first dgram went to port 69
518 * but reply may come from different one.
519 * Remember and use this new port (and IP) */
521 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
523 /* tftpd, or not the very first packet:
524 * socket is connect()ed, can just read from it. */
525 /* Don't full_read()!
526 * This is not TCP, one read == one pkt! */
527 len = safe_read(socket_fd, rbuf, io_bufsize);
530 goto send_read_err_pkt;
532 if (len < 4) { /* too small? */
537 /* Process recv'ed packet */
538 opcode = ntohs( ((uint16_t*)rbuf)[0] );
539 recv_blk = ntohs( ((uint16_t*)rbuf)[1] );
540 #if ENABLE_TFTP_DEBUG
541 fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk);
543 if (opcode == TFTP_ERROR) {
544 static const char errcode_str[] ALIGN1 =
550 "unknown transfer id\0"
551 "file already exists\0"
555 const char *msg = "";
557 if (len > 4 && rbuf[4] != '\0') {
559 rbuf[io_bufsize - 1] = '\0'; /* paranoia */
560 } else if (recv_blk <= 8) {
561 msg = nth_string(errcode_str, recv_blk);
563 bb_error_msg("server error: (%u) %s", recv_blk, msg);
567 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
570 if (opcode == TFTP_OACK) {
571 /* server seems to support options */
574 res = tftp_get_option("blksize", &rbuf[2], len - 2);
576 blksize = tftp_blksize_check(res, blksize);
578 error_pkt_reason = ERR_BAD_OPT;
581 io_bufsize = blksize + 4;
583 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
584 if (remote_file && G.size == 0) { /* if we don't know it yet */
585 res = tftp_get_option("tsize", &rbuf[2], len - 2);
587 G.size = bb_strtoull(res, NULL, 10);
589 tftp_progress_init();
593 if (CMD_GET(option_mask32)) {
594 /* We'll send ACK for OACK,
595 * such ACK has "block no" of 0 */
601 * "An option not acknowledged by the server
602 * must be ignored by the client and server
603 * as if it were never requested." */
604 if (blksize != TFTP_BLKSIZE_DEFAULT)
605 bb_error_msg("falling back to blocksize "TFTP_BLKSIZE_DEFAULT_STR);
606 blksize = TFTP_BLKSIZE_DEFAULT;
607 io_bufsize = TFTP_BLKSIZE_DEFAULT + 4;
610 /* block_nr is already advanced to next block# we expect
611 * to get / block# we are about to send next time */
613 if (CMD_GET(option_mask32) && (opcode == TFTP_DATA)) {
614 if (recv_blk == block_nr) {
615 int sz = full_write(local_fd, &rbuf[4], len - 4);
617 strcpy((char*)error_pkt_str, bb_msg_write_error);
618 error_pkt_reason = ERR_WRITE;
624 continue; /* send ACK */
626 /* Disabled to cope with servers with Sorcerer's Apprentice Syndrome */
628 if (recv_blk == (block_nr - 1)) {
629 /* Server lost our TFTP_ACK. Resend it */
636 if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) {
637 /* did peer ACK our last DATA pkt? */
638 if (recv_blk == (uint16_t) (block_nr - 1)) {
641 continue; /* send next block */
644 /* Awww... recv'd packet is not recognized! */
646 /* why recv_again? - rfc1123 says:
647 * "The sender (i.e., the side originating the DATA packets)
648 * must never resend the current DATA packet on receipt
649 * of a duplicate ACK".
650 * DATA pkts are resent ONLY on timeout.
651 * Thus "goto send_again" will ba a bad mistake above.
653 * http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome
655 } /* end of "while (1)" */
657 if (ENABLE_FEATURE_CLEAN_UP) {
663 return finished == 0; /* returns 1 on failure */
666 strcpy((char*)error_pkt_str, bb_msg_read_error);
668 if (error_pkt_str[0])
669 bb_error_msg("%s", (char*)error_pkt_str);
670 error_pkt[1] = TFTP_ERROR;
671 xsendto(socket_fd, error_pkt, 4 + 1 + strlen((char*)error_pkt_str),
672 &peer_lsa->u.sa, peer_lsa->len);
679 int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
680 int tftp_main(int argc UNUSED_PARAM, char **argv)
682 len_and_sockaddr *peer_lsa;
683 const char *local_file = NULL;
684 const char *remote_file = NULL;
685 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
686 const char *blksize_str = TFTP_BLKSIZE_DEFAULT_STR;
695 /* -p or -g is mandatory, and they are mutually exclusive */
696 opt_complementary = "" IF_FEATURE_TFTP_GET("g:") IF_FEATURE_TFTP_PUT("p:")
697 IF_GETPUT("g--p:p--g:");
699 IF_GETPUT(opt =) getopt32(argv,
700 IF_FEATURE_TFTP_GET("g") IF_FEATURE_TFTP_PUT("p")
701 "l:r:" IF_FEATURE_TFTP_BLOCKSIZE("b:"),
702 &local_file, &remote_file
703 IF_FEATURE_TFTP_BLOCKSIZE(, &blksize_str));
706 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
707 /* Check if the blksize is valid:
708 * RFC2348 says between 8 and 65464 */
709 blksize = tftp_blksize_check(blksize_str, 65564);
711 //bb_error_msg("bad block size");
718 const char *slash = strrchr(remote_file, '/');
719 local_file = slash ? slash + 1 : remote_file;
722 remote_file = local_file;
725 /* Error if filename or host is not known */
726 if (!remote_file || !argv[0])
729 port = bb_lookup_port(argv[1], "udp", 69);
730 peer_lsa = xhost2sockaddr(argv[0], port);
732 # if ENABLE_TFTP_DEBUG
733 fprintf(stderr, "using server '%s', remote_file '%s', local_file '%s'\n",
734 xmalloc_sockaddr2dotted(&peer_lsa->u.sa),
735 remote_file, local_file);
738 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
739 G.file = remote_file;
741 result = tftp_protocol(
742 NULL /*our_lsa*/, peer_lsa,
743 local_file, remote_file
744 IF_FEATURE_TFTP_BLOCKSIZE(, 1 /* want_transfer_size */)
745 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
747 tftp_progress_done();
749 if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) {
755 #endif /* ENABLE_TFTP */
758 int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
759 int tftpd_main(int argc UNUSED_PARAM, char **argv)
761 len_and_sockaddr *our_lsa;
762 len_and_sockaddr *peer_lsa;
763 char *local_file, *mode;
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;)
771 our_lsa = get_sock_lsa(STDIN_FILENO);
773 /* This is confusing:
774 *bb_error_msg_and_die("stdin is not a socket");
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
781 peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len);
782 peer_lsa->len = our_lsa->len;
784 /* Shifting to not collide with TFTP_OPTs */
785 opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:", &user_opt) << 8);
790 result = recv_from_to(STDIN_FILENO, block_buf, sizeof(block_buf),
792 &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len);
794 error_msg = "malformed packet";
795 opcode = ntohs(*(uint16_t*)block_buf);
796 if (result < 4 || result >= sizeof(block_buf)
797 || block_buf[result-1] != '\0'
798 || (IF_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */
800 IF_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */
805 local_file = block_buf + 2;
806 if (local_file[0] == '.' || strstr(local_file, "/.")) {
807 error_msg = "dot in file name";
810 mode = local_file + strlen(local_file) + 1;
811 if (mode >= block_buf + result || strcmp(mode, "octet") != 0) {
814 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
817 char *opt_str = mode + sizeof("octet");
818 int opt_len = block_buf + result - opt_str;
820 res = tftp_get_option("blksize", opt_str, opt_len);
822 blksize = tftp_blksize_check(res, 65564);
824 error_pkt_reason = ERR_BAD_OPT;
825 /* will just send error pkt */
829 if (opcode != TFTP_WRQ /* download? */
830 /* did client ask us about file size? */
831 && tftp_get_option("tsize", opt_str, opt_len)
833 want_transfer_size = 1;
839 if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) {
840 if (opt & TFTPD_OPT_r) {
841 /* This would mean "disk full" - not true */
842 /*error_pkt_reason = ERR_WRITE;*/
843 error_msg = bb_msg_write_error;
846 IF_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */
848 IF_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */
851 /* NB: if error_pkt_str or error_pkt_reason is set up,
852 * tftp_protocol() just sends one error pkt and returns */
855 close(STDIN_FILENO); /* close old, possibly wildcard socket */
856 /* tftp_protocol() will create new one, bound to particular local IP */
857 result = tftp_protocol(
859 local_file IF_TFTP(, NULL /*remote_file*/)
860 IF_FEATURE_TFTP_BLOCKSIZE(, want_transfer_size)
861 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
866 strcpy((char*)error_pkt_str, error_msg);
870 #endif /* ENABLE_TFTPD */
872 #endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */