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 //config: bool "tftp (12 kb)"
25 //config: Trivial File Transfer Protocol client. TFTP is usually used
26 //config: for simple, small transfers such as a root image
27 //config: for a network-enabled bootloader.
29 //config:config FEATURE_TFTP_PROGRESS_BAR
30 //config: bool "Enable progress bar"
32 //config: depends on TFTP
35 //config: bool "tftpd (10 kb)"
38 //config: Trivial File Transfer Protocol server.
39 //config: It expects that stdin is a datagram socket and a packet
40 //config: is already pending on it. It will exit after one transfer.
41 //config: In other words: it should be run from inetd in nowait mode,
42 //config: or from udpsvd. Example: "udpsvd -E 0 69 tftpd DIR"
44 //config:comment "Common options for tftp/tftpd"
45 //config: depends on TFTP || TFTPD
47 //config:config FEATURE_TFTP_GET
48 //config: bool "Enable 'tftp get' and/or tftpd upload code"
50 //config: depends on TFTP || TFTPD
52 //config: Add support for the GET command within the TFTP client. This allows
53 //config: a client to retrieve a file from a TFTP server.
54 //config: Also enable upload support in tftpd, if tftpd is selected.
56 //config: Note: this option does _not_ make tftpd capable of download
57 //config: (the usual operation people need from it)!
59 //config:config FEATURE_TFTP_PUT
60 //config: bool "Enable 'tftp put' and/or tftpd download code"
62 //config: depends on TFTP || TFTPD
64 //config: Add support for the PUT command within the TFTP client. This allows
65 //config: a client to transfer a file to a TFTP server.
66 //config: Also enable download support in tftpd, if tftpd is selected.
68 //config:config FEATURE_TFTP_BLOCKSIZE
69 //config: bool "Enable 'blksize' and 'tsize' protocol options"
71 //config: depends on TFTP || TFTPD
73 //config: Allow tftp to specify block size, and tftpd to understand
74 //config: "blksize" and "tsize" options.
76 //config:config TFTP_DEBUG
77 //config: bool "Enable debug"
79 //config: depends on TFTP || TFTPD
81 //config: Make tftp[d] print debugging messages on stderr.
82 //config: This is useful if you are diagnosing a bug in tftp[d].
84 //applet:#if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT
85 //applet:IF_TFTP(APPLET(tftp, BB_DIR_USR_BIN, BB_SUID_DROP))
86 //applet:IF_TFTPD(APPLET(tftpd, BB_DIR_USR_SBIN, BB_SUID_DROP))
89 //kbuild:lib-$(CONFIG_TFTP) += tftp.o
90 //kbuild:lib-$(CONFIG_TFTPD) += tftp.o
92 //usage:#define tftp_trivial_usage
93 //usage: "[OPTIONS] HOST [PORT]"
94 //usage:#define tftp_full_usage "\n\n"
95 //usage: "Transfer a file from/to tftp server\n"
96 //usage: "\n -l FILE Local FILE"
97 //usage: "\n -r FILE Remote FILE"
98 //usage: IF_FEATURE_TFTP_GET(
99 //usage: "\n -g Get file"
101 //usage: IF_FEATURE_TFTP_PUT(
102 //usage: "\n -p Put file"
104 //usage: IF_FEATURE_TFTP_BLOCKSIZE(
105 //usage: "\n -b SIZE Transfer blocks of SIZE octets"
108 //usage:#define tftpd_trivial_usage
109 //usage: "[-cr] [-u USER] [DIR]"
110 //usage:#define tftpd_full_usage "\n\n"
111 //usage: "Transfer a file on tftp client's request\n"
113 //usage: "tftpd should be used as an inetd service.\n"
114 //usage: "tftpd's line for inetd.conf:\n"
115 //usage: " 69 dgram udp nowait root tftpd tftpd -l /files/to/serve\n"
116 //usage: "It also can be ran from udpsvd:\n"
117 //usage: " udpsvd -vE 0.0.0.0 69 tftpd /files/to/serve\n"
118 //usage: "\n -r Prohibit upload"
119 //usage: "\n -c Allow file creation via upload"
120 //usage: "\n -u Access files as USER"
121 //usage: "\n -l Log to syslog (inetd mode requires this)"
124 #include "common_bufsiz.h"
127 #if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT
129 #define TFTP_BLKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */
130 #define TFTP_BLKSIZE_DEFAULT_STR "512"
131 /* Was 50 ms but users asked to bump it up a bit */
132 #define TFTP_TIMEOUT_MS 100
133 #define TFTP_MAXTIMEOUT_MS 2000
134 #define TFTP_NUM_RETRIES 12 /* number of backed-off retries */
136 /* opcodes we support */
144 /* error codes sent over network (we use only 0, 1, 3 and 8) */
145 /* generic (error message is included in the packet) */
149 /* disk full or allocation exceeded */
154 #define ERR_BAD_USER 7
155 #define ERR_BAD_OPT 8
157 /* masks coming from getopt32 */
159 TFTP_OPT_GET = (1 << 0),
160 TFTP_OPT_PUT = (1 << 1),
161 /* pseudo option: if set, it's tftpd */
162 TFTPD_OPT = (1 << 7) * ENABLE_TFTPD,
163 TFTPD_OPT_r = (1 << 8) * ENABLE_TFTPD,
164 TFTPD_OPT_c = (1 << 9) * ENABLE_TFTPD,
165 TFTPD_OPT_u = (1 << 10) * ENABLE_TFTPD,
166 TFTPD_OPT_l = (1 << 11) * ENABLE_TFTPD,
169 #if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT
170 #define IF_GETPUT(...)
171 #define CMD_GET(cmd) 1
172 #define CMD_PUT(cmd) 0
173 #elif !ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT
174 #define IF_GETPUT(...)
175 #define CMD_GET(cmd) 0
176 #define CMD_PUT(cmd) 1
178 #define IF_GETPUT(...) __VA_ARGS__
179 #define CMD_GET(cmd) ((cmd) & TFTP_OPT_GET)
180 #define CMD_PUT(cmd) ((cmd) & TFTP_OPT_PUT)
182 /* NB: in the code below
183 * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive
188 /* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */
189 uint8_t error_pkt[4 + 32];
191 /* Used in tftpd_main() for initial packet */
192 /* Some HP PA-RISC firmware always sends fixed 516-byte requests */
194 char block_buf_tail[1];
195 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
202 #define G (*(struct globals*)bb_common_bufsiz1)
203 #define INIT_G() do { \
204 setup_common_bufsiz(); \
205 BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
208 #define G_error_pkt_reason (G.error_pkt[3])
209 #define G_error_pkt_str ((char*)(G.error_pkt + 4))
211 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
212 static void tftp_progress_update(void)
214 bb_progress_update(&G.pmt, 0, G.pos, G.size);
216 static void tftp_progress_init(void)
218 bb_progress_init(&G.pmt, G.file);
219 tftp_progress_update();
221 static void tftp_progress_done(void)
223 if (is_bb_progress_inited(&G.pmt)) {
224 tftp_progress_update();
225 bb_putchar_stderr('\n');
226 bb_progress_free(&G.pmt);
230 # define tftp_progress_init() ((void)0)
231 # define tftp_progress_done() ((void)0)
234 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
236 static int tftp_blksize_check(const char *blksize_str, int maxsize)
238 /* Check if the blksize is valid:
239 * RFC2348 says between 8 and 65464,
240 * but our implementation makes it impossible
241 * to use blksizes smaller than 22 octets. */
242 unsigned blksize = bb_strtou(blksize_str, NULL, 10);
244 || (blksize < 24) || (blksize > maxsize)
246 bb_error_msg("bad blocksize '%s'", blksize_str);
249 # if ENABLE_TFTP_DEBUG
250 bb_error_msg("using blksize %u", blksize);
255 static char *tftp_get_option(const char *option, char *buf, int len)
262 * "opt_name<NUL>opt_val<NUL>opt_name2<NUL>opt_val2<NUL>..." */
265 /* Make sure options are terminated correctly */
266 for (k = 0; k < len; k++) {
267 if (buf[k] == '\0') {
273 if (opt_val == 0) { /* it's "name" part */
274 if (strcasecmp(buf, option) == 0) {
277 } else if (opt_found) {
292 static int tftp_protocol(
293 /* NULL if tftp, !NULL if tftpd: */
294 len_and_sockaddr *our_lsa,
295 len_and_sockaddr *peer_lsa,
296 const char *local_file
297 IF_TFTP(, const char *remote_file)
299 # define remote_file NULL
301 /* 1 for tftp; 1/0 for tftpd depending whether client asked about it: */
302 IF_FEATURE_TFTP_BLOCKSIZE(, int want_transfer_size)
303 IF_FEATURE_TFTP_BLOCKSIZE(, int blksize))
305 #if !ENABLE_FEATURE_TFTP_BLOCKSIZE
306 enum { blksize = TFTP_BLKSIZE_DEFAULT };
309 struct pollfd pfd[1];
310 #define socket_fd (pfd[0].fd)
313 IF_FEATURE_TFTP_BLOCKSIZE(smallint expect_OACK = 0;)
314 smallint finished = 0;
318 int open_mode, local_fd;
319 int retries, waittime_ms;
320 int io_bufsize = blksize + 4;
322 /* Can't use RESERVE_CONFIG_BUFFER here since the allocation
323 * size varies meaning BUFFERS_GO_ON_STACK would fail.
325 * We must keep the transmit and receive buffers separate
326 * in case we rcv a garbage pkt - we need to rexmit the last pkt.
328 char *xbuf = xmalloc(io_bufsize);
329 char *rbuf = xmalloc(io_bufsize);
331 socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0);
332 setsockopt_reuseaddr(socket_fd);
334 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
335 /* Create a socket which is:
336 * 1. bound to IP:port peer sent 1st datagram to,
337 * 2. connected to peer's IP:port
338 * This way we will answer from the IP:port peer
339 * expects, will not get any other packets on
340 * the socket, and also plain read/write will work. */
341 xbind(socket_fd, &our_lsa->u.sa, our_lsa->len);
342 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
344 /* Is there an error already? Send pkt and bail out */
345 if (G_error_pkt_reason || G_error_pkt_str[0])
349 change_identity(G.pw); /* initgroups, setgid, setuid */
353 /* Prepare open mode */
354 if (CMD_PUT(option_mask32)) {
355 open_mode = O_RDONLY;
357 open_mode = O_WRONLY | O_TRUNC | O_CREAT;
359 if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) {
360 /* tftpd without -c */
361 open_mode = O_WRONLY | O_TRUNC;
366 /* Examples of network traffic.
367 * Note two cases when ACKs with block# of 0 are sent.
369 * Download without options:
370 * tftp -> "\0\1FILENAME\0octet\0"
371 * "\0\3\0\1FILEDATA..." <- tftpd
374 * Download with option of blksize 16384:
375 * tftp -> "\0\1FILENAME\0octet\0blksize\00016384\0"
376 * "\0\6blksize\00016384\0" <- tftpd
378 * "\0\3\0\1FILEDATA..." <- tftpd
381 * Upload without options:
382 * tftp -> "\0\2FILENAME\0octet\0"
383 * "\0\4\0\0" <- tftpd
384 * tftp -> "\0\3\0\1FILEDATA..."
385 * "\0\4\0\1" <- tftpd
387 * Upload with option of blksize 16384:
388 * tftp -> "\0\2FILENAME\0octet\0blksize\00016384\0"
389 * "\0\6blksize\00016384\0" <- tftpd
390 * tftp -> "\0\3\0\1FILEDATA..."
391 * "\0\4\0\1" <- tftpd
397 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
398 /* Open file (must be after changing user) */
399 local_fd = open(local_file, open_mode, 0666);
401 G_error_pkt_reason = ERR_NOFILE;
402 strcpy(G_error_pkt_str, "can't open file");
405 /* gcc 4.3.1 would NOT optimize it out as it should! */
406 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
407 if (blksize != TFTP_BLKSIZE_DEFAULT || want_transfer_size) {
408 /* Create and send OACK packet. */
409 /* For the download case, block_nr is still 1 -
410 * we expect 1st ACK from peer to be for (block_nr-1),
411 * that is, for "block 0" which is our OACK pkt */
413 goto add_blksize_opt;
416 if (CMD_GET(option_mask32)) {
417 /* It's upload and we don't send OACK.
418 * We must ACK 1st packet (with filename)
419 * as if it is "block 0" */
423 /* Open file (must be after changing user) */
424 local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO;
425 if (NOT_LONE_DASH(local_file))
426 local_fd = xopen(local_file, open_mode);
427 /* Removing #if, or using if() statement instead of #if may lead to
428 * "warning: null argument where non-null required": */
432 /* We can't (and don't really need to) bind the socket:
433 * we don't know from which local IP datagrams will be sent,
434 * but kernel will pick the same IP every time (unless routing
435 * table is changed), thus peer will see dgrams consistently
436 * coming from the same IP.
437 * We would like to connect the socket, but since peer's
438 * UDP code can be less perfect than ours, _peer's_ IP:port
439 * in replies may differ from IP:port we used to send
440 * our first packet. We can connect() only when we get
445 if (CMD_GET(option_mask32)) {
448 /* add filename and mode */
449 /* fill in packet if the filename fits into xbuf */
450 len = strlen(remote_file) + 1;
451 if (2 + len + sizeof("octet") >= io_bufsize) {
452 bb_error_msg("remote filename is too long");
455 strcpy(cp, remote_file);
457 /* add "mode" part of the packet */
459 cp += sizeof("octet");
461 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
462 if (blksize == TFTP_BLKSIZE_DEFAULT && !want_transfer_size)
465 /* Need to add option to pkt */
466 if ((&xbuf[io_bufsize - 1] - cp) < sizeof("blksize NNNNN tsize ") + sizeof(off_t)*3) {
467 bb_error_msg("remote filename is too long");
472 #endif /* ENABLE_TFTP */
474 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
476 if (blksize != TFTP_BLKSIZE_DEFAULT) {
477 /* add "blksize", <nul>, blksize, <nul> */
478 strcpy(cp, "blksize");
479 cp += sizeof("blksize");
480 cp += snprintf(cp, 6, "%d", blksize) + 1;
482 if (want_transfer_size) {
483 /* add "tsize", <nul>, size, <nul> (see RFC2349) */
484 /* if tftp and downloading, we send "0" (since we opened local_fd with O_TRUNC)
485 * and this makes server to send "tsize" option with the size */
486 /* if tftp and uploading, we send file size (maybe dont, to not confuse old servers???) */
487 /* if tftpd and downloading, we are answering to client's request */
488 /* if tftpd and uploading: !want_transfer_size, this code is not executed */
491 cp += sizeof("tsize");
493 fstat(local_fd, &st);
494 cp += sprintf(cp, "%"OFF_FMT"u", (off_t)st.st_size) + 1;
495 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
496 /* Save for progress bar. If 0 (tftp downloading),
497 * we look at server's reply later */
499 if (remote_file && st.st_size)
500 tftp_progress_init();
504 /* First packet is built, so skip packet generation */
508 /* Using mostly goto's - continue/break will be less clear
509 * in where we actually jump to */
511 /* Build ACK or DATA */
513 *((uint16_t*)cp) = htons(block_nr);
517 if (CMD_PUT(option_mask32)) {
519 len = full_read(local_fd, cp, blksize);
521 goto send_read_err_pkt;
523 if (len != blksize) {
527 IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += len;)
531 *((uint16_t*)xbuf) = htons(opcode); /* fill in opcode part */
532 send_len = cp - xbuf;
533 /* NB: send_len value is preserved in code below
534 * for potential resend */
536 retries = TFTP_NUM_RETRIES; /* re-initialize */
537 waittime_ms = TFTP_TIMEOUT_MS;
540 #if ENABLE_TFTP_DEBUG
541 fprintf(stderr, "sending %u bytes\n", send_len);
542 for (cp = xbuf; cp < &xbuf[send_len]; cp++)
543 fprintf(stderr, "%02x ", (unsigned char) *cp);
544 fprintf(stderr, "\n");
546 xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len);
548 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
549 if (is_bb_progress_inited(&G.pmt))
550 tftp_progress_update();
552 /* Was it final ACK? then exit */
553 if (finished && (opcode == TFTP_ACK))
558 /*pfd[0].fd = socket_fd;*/
559 pfd[0].events = POLLIN;
560 switch (safe_poll(pfd, 1, waittime_ms)) {
562 /*bb_perror_msg("poll"); - done in safe_poll */
567 tftp_progress_done();
568 bb_error_msg("timeout");
569 goto ret; /* no err packet sent */
572 /* exponential backoff with limit */
573 waittime_ms += waittime_ms/2;
574 if (waittime_ms > TFTP_MAXTIMEOUT_MS) {
575 waittime_ms = TFTP_MAXTIMEOUT_MS;
578 goto send_again; /* resend last sent pkt */
581 /* tftp (not tftpd!) receiving 1st packet */
582 our_lsa = ((void*)(ptrdiff_t)-1); /* not NULL */
583 len = recvfrom(socket_fd, rbuf, io_bufsize, 0,
584 &peer_lsa->u.sa, &peer_lsa->len);
585 /* Our first dgram went to port 69
586 * but reply may come from different one.
587 * Remember and use this new port (and IP) */
589 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
591 /* tftpd, or not the very first packet:
592 * socket is connect()ed, can just read from it. */
593 /* Don't full_read()!
594 * This is not TCP, one read == one pkt! */
595 len = safe_read(socket_fd, rbuf, io_bufsize);
598 goto send_read_err_pkt;
600 if (len < 4) { /* too small? */
605 /* Process recv'ed packet */
606 opcode = ntohs( ((uint16_t*)rbuf)[0] );
607 recv_blk = ntohs( ((uint16_t*)rbuf)[1] );
608 #if ENABLE_TFTP_DEBUG
609 fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk);
611 if (opcode == TFTP_ERROR) {
612 static const char errcode_str[] ALIGN1 =
618 "unknown transfer id\0"
619 "file already exists\0"
623 const char *msg = "";
625 if (len > 4 && rbuf[4] != '\0') {
627 rbuf[io_bufsize - 1] = '\0'; /* paranoia */
628 } else if (recv_blk <= 8) {
629 msg = nth_string(errcode_str, recv_blk);
631 bb_error_msg("server error: (%u) %s", recv_blk, msg);
635 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
638 if (opcode == TFTP_OACK) {
639 /* server seems to support options */
642 res = tftp_get_option("blksize", &rbuf[2], len - 2);
644 blksize = tftp_blksize_check(res, blksize);
646 G_error_pkt_reason = ERR_BAD_OPT;
649 io_bufsize = blksize + 4;
651 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
652 if (remote_file && G.size == 0) { /* if we don't know it yet */
653 res = tftp_get_option("tsize", &rbuf[2], len - 2);
655 G.size = bb_strtoull(res, NULL, 10);
657 tftp_progress_init();
661 if (CMD_GET(option_mask32)) {
662 /* We'll send ACK for OACK,
663 * such ACK has "block no" of 0 */
669 * "An option not acknowledged by the server
670 * must be ignored by the client and server
671 * as if it were never requested." */
672 if (blksize != TFTP_BLKSIZE_DEFAULT)
673 bb_error_msg("falling back to blocksize "TFTP_BLKSIZE_DEFAULT_STR);
674 blksize = TFTP_BLKSIZE_DEFAULT;
675 io_bufsize = TFTP_BLKSIZE_DEFAULT + 4;
678 /* block_nr is already advanced to next block# we expect
679 * to get / block# we are about to send next time */
681 if (CMD_GET(option_mask32) && (opcode == TFTP_DATA)) {
682 if (recv_blk == block_nr) {
683 int sz = full_write(local_fd, &rbuf[4], len - 4);
685 strcpy(G_error_pkt_str, bb_msg_write_error);
686 G_error_pkt_reason = ERR_WRITE;
692 IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += sz;)
693 continue; /* send ACK */
695 /* Disabled to cope with servers with Sorcerer's Apprentice Syndrome */
697 if (recv_blk == (block_nr - 1)) {
698 /* Server lost our TFTP_ACK. Resend it */
705 if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) {
706 /* did peer ACK our last DATA pkt? */
707 if (recv_blk == (uint16_t) (block_nr - 1)) {
710 continue; /* send next block */
713 /* Awww... recv'd packet is not recognized! */
715 /* why recv_again? - rfc1123 says:
716 * "The sender (i.e., the side originating the DATA packets)
717 * must never resend the current DATA packet on receipt
718 * of a duplicate ACK".
719 * DATA pkts are resent ONLY on timeout.
720 * Thus "goto send_again" will ba a bad mistake above.
722 * http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome
724 } /* end of "while (1)" */
726 if (ENABLE_FEATURE_CLEAN_UP) {
732 return finished == 0; /* returns 1 on failure */
735 strcpy(G_error_pkt_str, bb_msg_read_error);
737 if (G_error_pkt_str[0])
738 bb_error_msg("%s", G_error_pkt_str);
739 G.error_pkt[1] = TFTP_ERROR;
740 xsendto(socket_fd, G.error_pkt, 4 + 1 + strlen(G_error_pkt_str),
741 &peer_lsa->u.sa, peer_lsa->len);
748 int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
749 int tftp_main(int argc UNUSED_PARAM, char **argv)
751 len_and_sockaddr *peer_lsa;
752 const char *local_file = NULL;
753 const char *remote_file = NULL;
754 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
755 const char *blksize_str = TFTP_BLKSIZE_DEFAULT_STR;
764 IF_GETPUT(opt =) getopt32(argv, "^"
765 IF_FEATURE_TFTP_GET("g") IF_FEATURE_TFTP_PUT("p")
766 "l:r:" IF_FEATURE_TFTP_BLOCKSIZE("b:")
768 /* -p or -g is mandatory, and they are mutually exclusive */
769 IF_FEATURE_TFTP_GET("g:") IF_FEATURE_TFTP_PUT("p:")
770 IF_GETPUT("g--p:p--g:"),
771 &local_file, &remote_file
772 IF_FEATURE_TFTP_BLOCKSIZE(, &blksize_str)
776 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
777 /* Check if the blksize is valid:
778 * RFC2348 says between 8 and 65464 */
779 blksize = tftp_blksize_check(blksize_str, 65564);
781 //bb_error_msg("bad block size");
788 const char *slash = strrchr(remote_file, '/');
789 local_file = slash ? slash + 1 : remote_file;
792 remote_file = local_file;
795 /* Error if filename or host is not known */
796 if (!remote_file || !argv[0])
799 port = bb_lookup_port(argv[1], "udp", 69);
800 peer_lsa = xhost2sockaddr(argv[0], port);
802 # if ENABLE_TFTP_DEBUG
803 fprintf(stderr, "using server '%s', remote_file '%s', local_file '%s'\n",
804 xmalloc_sockaddr2dotted(&peer_lsa->u.sa),
805 remote_file, local_file);
808 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
809 G.file = remote_file;
811 result = tftp_protocol(
812 NULL /*our_lsa*/, peer_lsa,
813 local_file, remote_file
814 IF_FEATURE_TFTP_BLOCKSIZE(, 1 /* want_transfer_size */)
815 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
817 tftp_progress_done();
819 if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) {
825 #endif /* ENABLE_TFTP */
828 int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
829 int tftpd_main(int argc UNUSED_PARAM, char **argv)
831 len_and_sockaddr *our_lsa;
832 len_and_sockaddr *peer_lsa;
833 char *mode, *user_opt;
834 char *local_file = local_file;
835 const char *error_msg;
836 int opt, result, opcode;
837 IF_FEATURE_TFTP_BLOCKSIZE(int blksize = TFTP_BLKSIZE_DEFAULT;)
838 IF_FEATURE_TFTP_BLOCKSIZE(int want_transfer_size = 0;)
842 our_lsa = get_sock_lsa(STDIN_FILENO);
844 /* This is confusing:
845 *bb_error_msg_and_die("stdin is not a socket");
848 /* Help text says that tftpd must be used as inetd service,
849 * which is by far the most usual cause of get_sock_lsa
852 peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len);
853 peer_lsa->len = our_lsa->len;
855 /* Shifting to not collide with TFTP_OPTs */
856 opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:l", &user_opt) << 8);
858 if (opt & TFTPD_OPT_l) {
859 openlog(applet_name, LOG_PID, LOG_DAEMON);
860 logmode = LOGMODE_SYSLOG;
862 if (opt & TFTPD_OPT_u) {
863 /* Must be before xchroot */
864 G.pw = xgetpwnam(user_opt);
870 result = recv_from_to(STDIN_FILENO,
871 G.block_buf, sizeof(G.block_buf) + 1,
872 /* ^^^ sizeof+1 to reliably detect oversized input */
874 &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len);
876 error_msg = "malformed packet";
877 opcode = ntohs(*(uint16_t*)G.block_buf);
878 if (result < 4 || result > sizeof(G.block_buf)
879 /*|| G.block_buf[result-1] != '\0' - bug compatibility, see below */
880 || (IF_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */
882 IF_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */
887 /* Some HP PA-RISC firmware always sends fixed 516-byte requests,
888 * with trailing garbage.
889 * Support that by not requiring NUL to be the last byte (see above).
890 * To make strXYZ() ops safe, force NUL termination:
892 G.block_buf_tail[0] = '\0';
894 local_file = G.block_buf + 2;
895 if (local_file[0] == '.' || strstr(local_file, "/.")) {
896 error_msg = "dot in file name";
899 mode = local_file + strlen(local_file) + 1;
900 /* RFC 1350 says mode string is case independent */
901 if (mode >= G.block_buf + result || strcasecmp(mode, "octet") != 0) {
904 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
907 char *opt_str = mode + sizeof("octet");
908 int opt_len = G.block_buf + result - opt_str;
910 res = tftp_get_option("blksize", opt_str, opt_len);
912 blksize = tftp_blksize_check(res, 65564);
914 G_error_pkt_reason = ERR_BAD_OPT;
915 /* will just send error pkt */
919 if (opcode != TFTP_WRQ /* download? */
920 /* did client ask us about file size? */
921 && tftp_get_option("tsize", opt_str, opt_len)
923 want_transfer_size = 1;
929 if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) {
930 if (opt & TFTPD_OPT_r) {
931 /* This would mean "disk full" - not true */
932 /*G_error_pkt_reason = ERR_WRITE;*/
933 error_msg = bb_msg_write_error;
936 IF_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */
938 IF_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */
941 /* NB: if G_error_pkt_str or G_error_pkt_reason is set up,
942 * tftp_protocol() just sends one error pkt and returns */
945 close(STDIN_FILENO); /* close old, possibly wildcard socket */
946 /* tftp_protocol() will create new one, bound to particular local IP */
947 result = tftp_protocol(
949 local_file IF_TFTP(, NULL /*remote_file*/)
950 IF_FEATURE_TFTP_BLOCKSIZE(, want_transfer_size)
951 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
956 strcpy(G_error_pkt_str, error_msg);
960 #endif /* ENABLE_TFTPD */
962 #endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */