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"
26 //usage: "\n -l FILE Local FILE"
27 //usage: "\n -r FILE Remote FILE"
28 //usage: IF_FEATURE_TFTP_GET(
29 //usage: "\n -g Get file"
31 //usage: IF_FEATURE_TFTP_PUT(
32 //usage: "\n -p Put file"
34 //usage: IF_FEATURE_TFTP_BLOCKSIZE(
35 //usage: "\n -b SIZE Transfer blocks of SIZE octets"
38 //usage:#define tftpd_trivial_usage
39 //usage: "[-cr] [-u USER] [DIR]"
40 //usage:#define tftpd_full_usage "\n\n"
41 //usage: "Transfer a file on tftp client's request\n"
43 //usage: "tftpd should be used as an inetd service.\n"
44 //usage: "tftpd's line for inetd.conf:\n"
45 //usage: " 69 dgram udp nowait root tftpd tftpd -l /files/to/serve\n"
46 //usage: "It also can be ran from udpsvd:\n"
47 //usage: " udpsvd -vE 0.0.0.0 69 tftpd /files/to/serve\n"
48 //usage: "\n -r Prohibit upload"
49 //usage: "\n -c Allow file creation via upload"
50 //usage: "\n -u Access files as USER"
51 //usage: "\n -l Log to syslog (inetd mode requires this)"
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,
95 TFTPD_OPT_l = (1 << 11) * ENABLE_TFTPD,
98 #if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT
99 #define IF_GETPUT(...)
100 #define CMD_GET(cmd) 1
101 #define CMD_PUT(cmd) 0
102 #elif !ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT
103 #define IF_GETPUT(...)
104 #define CMD_GET(cmd) 0
105 #define CMD_PUT(cmd) 1
107 #define IF_GETPUT(...) __VA_ARGS__
108 #define CMD_GET(cmd) ((cmd) & TFTP_OPT_GET)
109 #define CMD_PUT(cmd) ((cmd) & TFTP_OPT_PUT)
111 /* NB: in the code below
112 * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive
117 /* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */
118 uint8_t error_pkt[4 + 32];
120 /* used in tftpd_main(), a bit big for stack: */
121 char block_buf[TFTP_BLKSIZE_DEFAULT];
122 char block_buf_tail[1];
123 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
130 #define G (*(struct globals*)&bb_common_bufsiz1)
131 struct BUG_G_too_big {
132 char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
134 #define INIT_G() do { } while (0)
136 #define G_error_pkt_reason (G.error_pkt[3])
137 #define G_error_pkt_str ((char*)(G.error_pkt + 4))
139 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
140 static void tftp_progress_update(void)
142 bb_progress_update(&G.pmt, 0, G.pos, G.size);
144 static void tftp_progress_init(void)
146 bb_progress_init(&G.pmt, G.file);
147 tftp_progress_update();
149 static void tftp_progress_done(void)
151 if (is_bb_progress_inited(&G.pmt)) {
152 tftp_progress_update();
153 bb_putchar_stderr('\n');
154 bb_progress_free(&G.pmt);
158 # define tftp_progress_init() ((void)0)
159 # define tftp_progress_done() ((void)0)
162 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
164 static int tftp_blksize_check(const char *blksize_str, int maxsize)
166 /* Check if the blksize is valid:
167 * RFC2348 says between 8 and 65464,
168 * but our implementation makes it impossible
169 * to use blksizes smaller than 22 octets. */
170 unsigned blksize = bb_strtou(blksize_str, NULL, 10);
172 || (blksize < 24) || (blksize > maxsize)
174 bb_error_msg("bad blocksize '%s'", blksize_str);
177 # if ENABLE_TFTP_DEBUG
178 bb_error_msg("using blksize %u", blksize);
183 static char *tftp_get_option(const char *option, char *buf, int len)
190 * "opt_name<NUL>opt_val<NUL>opt_name2<NUL>opt_val2<NUL>..." */
193 /* Make sure options are terminated correctly */
194 for (k = 0; k < len; k++) {
195 if (buf[k] == '\0') {
201 if (opt_val == 0) { /* it's "name" part */
202 if (strcasecmp(buf, option) == 0) {
205 } else if (opt_found) {
220 static int tftp_protocol(
221 /* NULL if tftp, !NULL if tftpd: */
222 len_and_sockaddr *our_lsa,
223 len_and_sockaddr *peer_lsa,
224 const char *local_file
225 IF_TFTP(, const char *remote_file)
227 # define remote_file NULL
229 /* 1 for tftp; 1/0 for tftpd depending whether client asked about it: */
230 IF_FEATURE_TFTP_BLOCKSIZE(, int want_transfer_size)
231 IF_FEATURE_TFTP_BLOCKSIZE(, int blksize))
233 #if !ENABLE_FEATURE_TFTP_BLOCKSIZE
234 enum { blksize = TFTP_BLKSIZE_DEFAULT };
237 struct pollfd pfd[1];
238 #define socket_fd (pfd[0].fd)
241 IF_FEATURE_TFTP_BLOCKSIZE(smallint expect_OACK = 0;)
242 smallint finished = 0;
246 int open_mode, local_fd;
247 int retries, waittime_ms;
248 int io_bufsize = blksize + 4;
250 /* Can't use RESERVE_CONFIG_BUFFER here since the allocation
251 * size varies meaning BUFFERS_GO_ON_STACK would fail.
253 * We must keep the transmit and receive buffers separate
254 * in case we rcv a garbage pkt - we need to rexmit the last pkt.
256 char *xbuf = xmalloc(io_bufsize);
257 char *rbuf = xmalloc(io_bufsize);
259 socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0);
260 setsockopt_reuseaddr(socket_fd);
262 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
263 /* Create a socket which is:
264 * 1. bound to IP:port peer sent 1st datagram to,
265 * 2. connected to peer's IP:port
266 * This way we will answer from the IP:port peer
267 * expects, will not get any other packets on
268 * the socket, and also plain read/write will work. */
269 xbind(socket_fd, &our_lsa->u.sa, our_lsa->len);
270 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
272 /* Is there an error already? Send pkt and bail out */
273 if (G_error_pkt_reason || G_error_pkt_str[0])
277 change_identity(G.pw); /* initgroups, setgid, setuid */
281 /* Prepare open mode */
282 if (CMD_PUT(option_mask32)) {
283 open_mode = O_RDONLY;
285 open_mode = O_WRONLY | O_TRUNC | O_CREAT;
287 if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) {
288 /* tftpd without -c */
289 open_mode = O_WRONLY | O_TRUNC;
294 /* Examples of network traffic.
295 * Note two cases when ACKs with block# of 0 are sent.
297 * Download without options:
298 * tftp -> "\0\1FILENAME\0octet\0"
299 * "\0\3\0\1FILEDATA..." <- tftpd
302 * Download with option of blksize 16384:
303 * tftp -> "\0\1FILENAME\0octet\0blksize\00016384\0"
304 * "\0\6blksize\00016384\0" <- tftpd
306 * "\0\3\0\1FILEDATA..." <- tftpd
309 * Upload without options:
310 * tftp -> "\0\2FILENAME\0octet\0"
311 * "\0\4\0\0" <- tftpd
312 * tftp -> "\0\3\0\1FILEDATA..."
313 * "\0\4\0\1" <- tftpd
315 * Upload with option of blksize 16384:
316 * tftp -> "\0\2FILENAME\0octet\0blksize\00016384\0"
317 * "\0\6blksize\00016384\0" <- tftpd
318 * tftp -> "\0\3\0\1FILEDATA..."
319 * "\0\4\0\1" <- tftpd
325 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
326 /* Open file (must be after changing user) */
327 local_fd = open(local_file, open_mode, 0666);
329 G_error_pkt_reason = ERR_NOFILE;
330 strcpy(G_error_pkt_str, "can't open file");
333 /* gcc 4.3.1 would NOT optimize it out as it should! */
334 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
335 if (blksize != TFTP_BLKSIZE_DEFAULT || want_transfer_size) {
336 /* Create and send OACK packet. */
337 /* For the download case, block_nr is still 1 -
338 * we expect 1st ACK from peer to be for (block_nr-1),
339 * that is, for "block 0" which is our OACK pkt */
341 goto add_blksize_opt;
344 if (CMD_GET(option_mask32)) {
345 /* It's upload and we don't send OACK.
346 * We must ACK 1st packet (with filename)
347 * as if it is "block 0" */
352 /* Open file (must be after changing user) */
353 local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO;
354 if (NOT_LONE_DASH(local_file))
355 local_fd = xopen(local_file, open_mode);
356 /* Removing #if, or using if() statement instead of #if may lead to
357 * "warning: null argument where non-null required": */
361 /* We can't (and don't really need to) bind the socket:
362 * we don't know from which local IP datagrams will be sent,
363 * but kernel will pick the same IP every time (unless routing
364 * table is changed), thus peer will see dgrams consistently
365 * coming from the same IP.
366 * We would like to connect the socket, but since peer's
367 * UDP code can be less perfect than ours, _peer's_ IP:port
368 * in replies may differ from IP:port we used to send
369 * our first packet. We can connect() only when we get
374 if (CMD_GET(option_mask32)) {
377 /* add filename and mode */
378 /* fill in packet if the filename fits into xbuf */
379 len = strlen(remote_file) + 1;
380 if (2 + len + sizeof("octet") >= io_bufsize) {
381 bb_error_msg("remote filename is too long");
384 strcpy(cp, remote_file);
386 /* add "mode" part of the packet */
388 cp += sizeof("octet");
390 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
391 if (blksize == TFTP_BLKSIZE_DEFAULT && !want_transfer_size)
394 /* Need to add option to pkt */
395 if ((&xbuf[io_bufsize - 1] - cp) < sizeof("blksize NNNNN tsize ") + sizeof(off_t)*3) {
396 bb_error_msg("remote filename is too long");
401 #endif /* ENABLE_TFTP */
403 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
405 if (blksize != TFTP_BLKSIZE_DEFAULT) {
406 /* add "blksize", <nul>, blksize, <nul> */
407 strcpy(cp, "blksize");
408 cp += sizeof("blksize");
409 cp += snprintf(cp, 6, "%d", blksize) + 1;
411 if (want_transfer_size) {
412 /* add "tsize", <nul>, size, <nul> (see RFC2349) */
413 /* if tftp and downloading, we send "0" (since we opened local_fd with O_TRUNC)
414 * and this makes server to send "tsize" option with the size */
415 /* if tftp and uploading, we send file size (maybe dont, to not confuse old servers???) */
416 /* if tftpd and downloading, we are answering to client's request */
417 /* if tftpd and uploading: !want_transfer_size, this code is not executed */
420 cp += sizeof("tsize");
422 fstat(local_fd, &st);
423 cp += sprintf(cp, "%"OFF_FMT"u", (off_t)st.st_size) + 1;
424 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
425 /* Save for progress bar. If 0 (tftp downloading),
426 * we look at server's reply later */
428 if (remote_file && st.st_size)
429 tftp_progress_init();
433 /* First packet is built, so skip packet generation */
437 /* Using mostly goto's - continue/break will be less clear
438 * in where we actually jump to */
440 /* Build ACK or DATA */
442 *((uint16_t*)cp) = htons(block_nr);
446 if (CMD_PUT(option_mask32)) {
448 len = full_read(local_fd, cp, blksize);
450 goto send_read_err_pkt;
452 if (len != blksize) {
456 IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += len;)
460 *((uint16_t*)xbuf) = htons(opcode); /* fill in opcode part */
461 send_len = cp - xbuf;
462 /* NB: send_len value is preserved in code below
463 * for potential resend */
465 retries = TFTP_NUM_RETRIES; /* re-initialize */
466 waittime_ms = TFTP_TIMEOUT_MS;
469 #if ENABLE_TFTP_DEBUG
470 fprintf(stderr, "sending %u bytes\n", send_len);
471 for (cp = xbuf; cp < &xbuf[send_len]; cp++)
472 fprintf(stderr, "%02x ", (unsigned char) *cp);
473 fprintf(stderr, "\n");
475 xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len);
477 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
478 if (is_bb_progress_inited(&G.pmt))
479 tftp_progress_update();
481 /* Was it final ACK? then exit */
482 if (finished && (opcode == TFTP_ACK))
487 /*pfd[0].fd = socket_fd;*/
488 pfd[0].events = POLLIN;
489 switch (safe_poll(pfd, 1, waittime_ms)) {
491 /*bb_perror_msg("poll"); - done in safe_poll */
496 tftp_progress_done();
497 bb_error_msg("timeout");
498 goto ret; /* no err packet sent */
501 /* exponential backoff with limit */
502 waittime_ms += waittime_ms/2;
503 if (waittime_ms > TFTP_MAXTIMEOUT_MS) {
504 waittime_ms = TFTP_MAXTIMEOUT_MS;
507 goto send_again; /* resend last sent pkt */
510 /* tftp (not tftpd!) receiving 1st packet */
511 our_lsa = ((void*)(ptrdiff_t)-1); /* not NULL */
512 len = recvfrom(socket_fd, rbuf, io_bufsize, 0,
513 &peer_lsa->u.sa, &peer_lsa->len);
514 /* Our first dgram went to port 69
515 * but reply may come from different one.
516 * Remember and use this new port (and IP) */
518 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
520 /* tftpd, or not the very first packet:
521 * socket is connect()ed, can just read from it. */
522 /* Don't full_read()!
523 * This is not TCP, one read == one pkt! */
524 len = safe_read(socket_fd, rbuf, io_bufsize);
527 goto send_read_err_pkt;
529 if (len < 4) { /* too small? */
534 /* Process recv'ed packet */
535 opcode = ntohs( ((uint16_t*)rbuf)[0] );
536 recv_blk = ntohs( ((uint16_t*)rbuf)[1] );
537 #if ENABLE_TFTP_DEBUG
538 fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk);
540 if (opcode == TFTP_ERROR) {
541 static const char errcode_str[] ALIGN1 =
547 "unknown transfer id\0"
548 "file already exists\0"
552 const char *msg = "";
554 if (len > 4 && rbuf[4] != '\0') {
556 rbuf[io_bufsize - 1] = '\0'; /* paranoia */
557 } else if (recv_blk <= 8) {
558 msg = nth_string(errcode_str, recv_blk);
560 bb_error_msg("server error: (%u) %s", recv_blk, msg);
564 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
567 if (opcode == TFTP_OACK) {
568 /* server seems to support options */
571 res = tftp_get_option("blksize", &rbuf[2], len - 2);
573 blksize = tftp_blksize_check(res, blksize);
575 G_error_pkt_reason = ERR_BAD_OPT;
578 io_bufsize = blksize + 4;
580 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
581 if (remote_file && G.size == 0) { /* if we don't know it yet */
582 res = tftp_get_option("tsize", &rbuf[2], len - 2);
584 G.size = bb_strtoull(res, NULL, 10);
586 tftp_progress_init();
590 if (CMD_GET(option_mask32)) {
591 /* We'll send ACK for OACK,
592 * such ACK has "block no" of 0 */
598 * "An option not acknowledged by the server
599 * must be ignored by the client and server
600 * as if it were never requested." */
601 if (blksize != TFTP_BLKSIZE_DEFAULT)
602 bb_error_msg("falling back to blocksize "TFTP_BLKSIZE_DEFAULT_STR);
603 blksize = TFTP_BLKSIZE_DEFAULT;
604 io_bufsize = TFTP_BLKSIZE_DEFAULT + 4;
607 /* block_nr is already advanced to next block# we expect
608 * to get / block# we are about to send next time */
610 if (CMD_GET(option_mask32) && (opcode == TFTP_DATA)) {
611 if (recv_blk == block_nr) {
612 int sz = full_write(local_fd, &rbuf[4], len - 4);
614 strcpy(G_error_pkt_str, bb_msg_write_error);
615 G_error_pkt_reason = ERR_WRITE;
621 IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += sz;)
622 continue; /* send ACK */
624 /* Disabled to cope with servers with Sorcerer's Apprentice Syndrome */
626 if (recv_blk == (block_nr - 1)) {
627 /* Server lost our TFTP_ACK. Resend it */
634 if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) {
635 /* did peer ACK our last DATA pkt? */
636 if (recv_blk == (uint16_t) (block_nr - 1)) {
639 continue; /* send next block */
642 /* Awww... recv'd packet is not recognized! */
644 /* why recv_again? - rfc1123 says:
645 * "The sender (i.e., the side originating the DATA packets)
646 * must never resend the current DATA packet on receipt
647 * of a duplicate ACK".
648 * DATA pkts are resent ONLY on timeout.
649 * Thus "goto send_again" will ba a bad mistake above.
651 * http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome
653 } /* end of "while (1)" */
655 if (ENABLE_FEATURE_CLEAN_UP) {
661 return finished == 0; /* returns 1 on failure */
664 strcpy(G_error_pkt_str, bb_msg_read_error);
666 if (G_error_pkt_str[0])
667 bb_error_msg("%s", G_error_pkt_str);
668 G.error_pkt[1] = TFTP_ERROR;
669 xsendto(socket_fd, G.error_pkt, 4 + 1 + strlen(G_error_pkt_str),
670 &peer_lsa->u.sa, peer_lsa->len);
677 int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
678 int tftp_main(int argc UNUSED_PARAM, char **argv)
680 len_and_sockaddr *peer_lsa;
681 const char *local_file = NULL;
682 const char *remote_file = NULL;
683 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
684 const char *blksize_str = TFTP_BLKSIZE_DEFAULT_STR;
693 /* -p or -g is mandatory, and they are mutually exclusive */
694 opt_complementary = "" IF_FEATURE_TFTP_GET("g:") IF_FEATURE_TFTP_PUT("p:")
695 IF_GETPUT("g--p:p--g:");
697 IF_GETPUT(opt =) getopt32(argv,
698 IF_FEATURE_TFTP_GET("g") IF_FEATURE_TFTP_PUT("p")
699 "l:r:" IF_FEATURE_TFTP_BLOCKSIZE("b:"),
700 &local_file, &remote_file
701 IF_FEATURE_TFTP_BLOCKSIZE(, &blksize_str));
704 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
705 /* Check if the blksize is valid:
706 * RFC2348 says between 8 and 65464 */
707 blksize = tftp_blksize_check(blksize_str, 65564);
709 //bb_error_msg("bad block size");
716 const char *slash = strrchr(remote_file, '/');
717 local_file = slash ? slash + 1 : remote_file;
720 remote_file = local_file;
723 /* Error if filename or host is not known */
724 if (!remote_file || !argv[0])
727 port = bb_lookup_port(argv[1], "udp", 69);
728 peer_lsa = xhost2sockaddr(argv[0], port);
730 # if ENABLE_TFTP_DEBUG
731 fprintf(stderr, "using server '%s', remote_file '%s', local_file '%s'\n",
732 xmalloc_sockaddr2dotted(&peer_lsa->u.sa),
733 remote_file, local_file);
736 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
737 G.file = remote_file;
739 result = tftp_protocol(
740 NULL /*our_lsa*/, peer_lsa,
741 local_file, remote_file
742 IF_FEATURE_TFTP_BLOCKSIZE(, 1 /* want_transfer_size */)
743 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
745 tftp_progress_done();
747 if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) {
753 #endif /* ENABLE_TFTP */
756 int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
757 int tftpd_main(int argc UNUSED_PARAM, char **argv)
759 len_and_sockaddr *our_lsa;
760 len_and_sockaddr *peer_lsa;
761 char *local_file, *mode, *user_opt;
762 const char *error_msg;
763 int opt, result, opcode;
764 IF_FEATURE_TFTP_BLOCKSIZE(int blksize = TFTP_BLKSIZE_DEFAULT;)
765 IF_FEATURE_TFTP_BLOCKSIZE(int want_transfer_size = 0;)
769 our_lsa = get_sock_lsa(STDIN_FILENO);
771 /* This is confusing:
772 *bb_error_msg_and_die("stdin is not a socket");
775 /* Help text says that tftpd must be used as inetd service,
776 * which is by far the most usual cause of get_sock_lsa
779 peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len);
780 peer_lsa->len = our_lsa->len;
782 /* Shifting to not collide with TFTP_OPTs */
783 opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:l", &user_opt) << 8);
785 if (opt & TFTPD_OPT_l) {
786 openlog(applet_name, LOG_PID, LOG_DAEMON);
787 logmode = LOGMODE_SYSLOG;
789 if (opt & TFTPD_OPT_u) {
790 /* Must be before xchroot */
791 G.pw = xgetpwnam(user_opt);
797 result = recv_from_to(STDIN_FILENO,
798 G.block_buf, sizeof(G.block_buf) + 1,
799 /* ^^^ sizeof+1 to reliably detect oversized input */
801 &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len);
803 error_msg = "malformed packet";
804 opcode = ntohs(*(uint16_t*)G.block_buf);
805 if (result < 4 || result > sizeof(G.block_buf)
806 /*|| G.block_buf[result-1] != '\0' - bug compatibility, see below */
807 || (IF_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */
809 IF_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */
814 /* Some HP PA-RISC firmware always sends fixed 512-byte requests,
815 * with trailing garbage.
816 * Support that by not requiring NUL to be the last byte (see above).
817 * To make strXYZ() ops safe, force NUL termination:
819 G.block_buf_tail[0] = '\0';
821 local_file = G.block_buf + 2;
822 if (local_file[0] == '.' || strstr(local_file, "/.")) {
823 error_msg = "dot in file name";
826 mode = local_file + strlen(local_file) + 1;
827 /* RFC 1350 says mode string is case independent */
828 if (mode >= G.block_buf + result || strcasecmp(mode, "octet") != 0) {
831 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
834 char *opt_str = mode + sizeof("octet");
835 int opt_len = G.block_buf + result - opt_str;
837 res = tftp_get_option("blksize", opt_str, opt_len);
839 blksize = tftp_blksize_check(res, 65564);
841 G_error_pkt_reason = ERR_BAD_OPT;
842 /* will just send error pkt */
846 if (opcode != TFTP_WRQ /* download? */
847 /* did client ask us about file size? */
848 && tftp_get_option("tsize", opt_str, opt_len)
850 want_transfer_size = 1;
856 if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) {
857 if (opt & TFTPD_OPT_r) {
858 /* This would mean "disk full" - not true */
859 /*G_error_pkt_reason = ERR_WRITE;*/
860 error_msg = bb_msg_write_error;
863 IF_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */
865 IF_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */
868 /* NB: if G_error_pkt_str or G_error_pkt_reason is set up,
869 * tftp_protocol() just sends one error pkt and returns */
872 close(STDIN_FILENO); /* close old, possibly wildcard socket */
873 /* tftp_protocol() will create new one, bound to particular local IP */
874 result = tftp_protocol(
876 local_file IF_TFTP(, NULL /*remote_file*/)
877 IF_FEATURE_TFTP_BLOCKSIZE(, want_transfer_size)
878 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
883 strcpy(G_error_pkt_str, error_msg);
887 #endif /* ENABLE_TFTPD */
889 #endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */