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)"
54 #include "common_bufsiz.h"
57 #if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT
59 #define TFTP_BLKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */
60 #define TFTP_BLKSIZE_DEFAULT_STR "512"
61 /* Was 50 ms but users asked to bump it up a bit */
62 #define TFTP_TIMEOUT_MS 100
63 #define TFTP_MAXTIMEOUT_MS 2000
64 #define TFTP_NUM_RETRIES 12 /* number of backed-off retries */
66 /* opcodes we support */
74 /* error codes sent over network (we use only 0, 1, 3 and 8) */
75 /* generic (error message is included in the packet) */
79 /* disk full or allocation exceeded */
84 #define ERR_BAD_USER 7
87 /* masks coming from getopt32 */
89 TFTP_OPT_GET = (1 << 0),
90 TFTP_OPT_PUT = (1 << 1),
91 /* pseudo option: if set, it's tftpd */
92 TFTPD_OPT = (1 << 7) * ENABLE_TFTPD,
93 TFTPD_OPT_r = (1 << 8) * ENABLE_TFTPD,
94 TFTPD_OPT_c = (1 << 9) * ENABLE_TFTPD,
95 TFTPD_OPT_u = (1 << 10) * ENABLE_TFTPD,
96 TFTPD_OPT_l = (1 << 11) * ENABLE_TFTPD,
99 #if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT
100 #define IF_GETPUT(...)
101 #define CMD_GET(cmd) 1
102 #define CMD_PUT(cmd) 0
103 #elif !ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT
104 #define IF_GETPUT(...)
105 #define CMD_GET(cmd) 0
106 #define CMD_PUT(cmd) 1
108 #define IF_GETPUT(...) __VA_ARGS__
109 #define CMD_GET(cmd) ((cmd) & TFTP_OPT_GET)
110 #define CMD_PUT(cmd) ((cmd) & TFTP_OPT_PUT)
112 /* NB: in the code below
113 * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive
118 /* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */
119 uint8_t error_pkt[4 + 32];
121 /* Used in tftpd_main() for initial packet */
122 /* Some HP PA-RISC firmware always sends fixed 516-byte requests */
124 char block_buf_tail[1];
125 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
132 #define G (*(struct globals*)bb_common_bufsiz1)
133 #define INIT_G() do { \
134 setup_common_bufsiz(); \
135 BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
138 #define G_error_pkt_reason (G.error_pkt[3])
139 #define G_error_pkt_str ((char*)(G.error_pkt + 4))
141 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
142 static void tftp_progress_update(void)
144 bb_progress_update(&G.pmt, 0, G.pos, G.size);
146 static void tftp_progress_init(void)
148 bb_progress_init(&G.pmt, G.file);
149 tftp_progress_update();
151 static void tftp_progress_done(void)
153 if (is_bb_progress_inited(&G.pmt)) {
154 tftp_progress_update();
155 bb_putchar_stderr('\n');
156 bb_progress_free(&G.pmt);
160 # define tftp_progress_init() ((void)0)
161 # define tftp_progress_done() ((void)0)
164 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
166 static int tftp_blksize_check(const char *blksize_str, int maxsize)
168 /* Check if the blksize is valid:
169 * RFC2348 says between 8 and 65464,
170 * but our implementation makes it impossible
171 * to use blksizes smaller than 22 octets. */
172 unsigned blksize = bb_strtou(blksize_str, NULL, 10);
174 || (blksize < 24) || (blksize > maxsize)
176 bb_error_msg("bad blocksize '%s'", blksize_str);
179 # if ENABLE_TFTP_DEBUG
180 bb_error_msg("using blksize %u", blksize);
185 static char *tftp_get_option(const char *option, char *buf, int len)
192 * "opt_name<NUL>opt_val<NUL>opt_name2<NUL>opt_val2<NUL>..." */
195 /* Make sure options are terminated correctly */
196 for (k = 0; k < len; k++) {
197 if (buf[k] == '\0') {
203 if (opt_val == 0) { /* it's "name" part */
204 if (strcasecmp(buf, option) == 0) {
207 } else if (opt_found) {
222 static int tftp_protocol(
223 /* NULL if tftp, !NULL if tftpd: */
224 len_and_sockaddr *our_lsa,
225 len_and_sockaddr *peer_lsa,
226 const char *local_file
227 IF_TFTP(, const char *remote_file)
229 # define remote_file NULL
231 /* 1 for tftp; 1/0 for tftpd depending whether client asked about it: */
232 IF_FEATURE_TFTP_BLOCKSIZE(, int want_transfer_size)
233 IF_FEATURE_TFTP_BLOCKSIZE(, int blksize))
235 #if !ENABLE_FEATURE_TFTP_BLOCKSIZE
236 enum { blksize = TFTP_BLKSIZE_DEFAULT };
239 struct pollfd pfd[1];
240 #define socket_fd (pfd[0].fd)
243 IF_FEATURE_TFTP_BLOCKSIZE(smallint expect_OACK = 0;)
244 smallint finished = 0;
248 int open_mode, local_fd;
249 int retries, waittime_ms;
250 int io_bufsize = blksize + 4;
252 /* Can't use RESERVE_CONFIG_BUFFER here since the allocation
253 * size varies meaning BUFFERS_GO_ON_STACK would fail.
255 * We must keep the transmit and receive buffers separate
256 * in case we rcv a garbage pkt - we need to rexmit the last pkt.
258 char *xbuf = xmalloc(io_bufsize);
259 char *rbuf = xmalloc(io_bufsize);
261 socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0);
262 setsockopt_reuseaddr(socket_fd);
264 if (!ENABLE_TFTP || our_lsa) { /* tftpd */
265 /* Create a socket which is:
266 * 1. bound to IP:port peer sent 1st datagram to,
267 * 2. connected to peer's IP:port
268 * This way we will answer from the IP:port peer
269 * expects, will not get any other packets on
270 * the socket, and also plain read/write will work. */
271 xbind(socket_fd, &our_lsa->u.sa, our_lsa->len);
272 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
274 /* Is there an error already? Send pkt and bail out */
275 if (G_error_pkt_reason || G_error_pkt_str[0])
279 change_identity(G.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 G_error_pkt_reason = ERR_NOFILE;
332 strcpy(G_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" */
353 /* Open file (must be after changing user) */
354 local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO;
355 if (NOT_LONE_DASH(local_file))
356 local_fd = xopen(local_file, open_mode);
357 /* Removing #if, or using if() statement instead of #if may lead to
358 * "warning: null argument where non-null required": */
362 /* We can't (and don't really need to) bind the socket:
363 * we don't know from which local IP datagrams will be sent,
364 * but kernel will pick the same IP every time (unless routing
365 * table is changed), thus peer will see dgrams consistently
366 * coming from the same IP.
367 * We would like to connect the socket, but since peer's
368 * UDP code can be less perfect than ours, _peer's_ IP:port
369 * in replies may differ from IP:port we used to send
370 * our first packet. We can connect() only when we get
375 if (CMD_GET(option_mask32)) {
378 /* add filename and mode */
379 /* fill in packet if the filename fits into xbuf */
380 len = strlen(remote_file) + 1;
381 if (2 + len + sizeof("octet") >= io_bufsize) {
382 bb_error_msg("remote filename is too long");
385 strcpy(cp, remote_file);
387 /* add "mode" part of the packet */
389 cp += sizeof("octet");
391 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
392 if (blksize == TFTP_BLKSIZE_DEFAULT && !want_transfer_size)
395 /* Need to add option to pkt */
396 if ((&xbuf[io_bufsize - 1] - cp) < sizeof("blksize NNNNN tsize ") + sizeof(off_t)*3) {
397 bb_error_msg("remote filename is too long");
402 #endif /* ENABLE_TFTP */
404 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
406 if (blksize != TFTP_BLKSIZE_DEFAULT) {
407 /* add "blksize", <nul>, blksize, <nul> */
408 strcpy(cp, "blksize");
409 cp += sizeof("blksize");
410 cp += snprintf(cp, 6, "%d", blksize) + 1;
412 if (want_transfer_size) {
413 /* add "tsize", <nul>, size, <nul> (see RFC2349) */
414 /* if tftp and downloading, we send "0" (since we opened local_fd with O_TRUNC)
415 * and this makes server to send "tsize" option with the size */
416 /* if tftp and uploading, we send file size (maybe dont, to not confuse old servers???) */
417 /* if tftpd and downloading, we are answering to client's request */
418 /* if tftpd and uploading: !want_transfer_size, this code is not executed */
421 cp += sizeof("tsize");
423 fstat(local_fd, &st);
424 cp += sprintf(cp, "%"OFF_FMT"u", (off_t)st.st_size) + 1;
425 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
426 /* Save for progress bar. If 0 (tftp downloading),
427 * we look at server's reply later */
429 if (remote_file && st.st_size)
430 tftp_progress_init();
434 /* First packet is built, so skip packet generation */
438 /* Using mostly goto's - continue/break will be less clear
439 * in where we actually jump to */
441 /* Build ACK or DATA */
443 *((uint16_t*)cp) = htons(block_nr);
447 if (CMD_PUT(option_mask32)) {
449 len = full_read(local_fd, cp, blksize);
451 goto send_read_err_pkt;
453 if (len != blksize) {
457 IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += len;)
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 (is_bb_progress_inited(&G.pmt))
480 tftp_progress_update();
482 /* Was it final ACK? then exit */
483 if (finished && (opcode == TFTP_ACK))
488 /*pfd[0].fd = socket_fd;*/
489 pfd[0].events = POLLIN;
490 switch (safe_poll(pfd, 1, waittime_ms)) {
492 /*bb_perror_msg("poll"); - done in safe_poll */
497 tftp_progress_done();
498 bb_error_msg("timeout");
499 goto ret; /* no err packet sent */
502 /* exponential backoff with limit */
503 waittime_ms += waittime_ms/2;
504 if (waittime_ms > TFTP_MAXTIMEOUT_MS) {
505 waittime_ms = TFTP_MAXTIMEOUT_MS;
508 goto send_again; /* resend last sent pkt */
511 /* tftp (not tftpd!) receiving 1st packet */
512 our_lsa = ((void*)(ptrdiff_t)-1); /* not NULL */
513 len = recvfrom(socket_fd, rbuf, io_bufsize, 0,
514 &peer_lsa->u.sa, &peer_lsa->len);
515 /* Our first dgram went to port 69
516 * but reply may come from different one.
517 * Remember and use this new port (and IP) */
519 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
521 /* tftpd, or not the very first packet:
522 * socket is connect()ed, can just read from it. */
523 /* Don't full_read()!
524 * This is not TCP, one read == one pkt! */
525 len = safe_read(socket_fd, rbuf, io_bufsize);
528 goto send_read_err_pkt;
530 if (len < 4) { /* too small? */
535 /* Process recv'ed packet */
536 opcode = ntohs( ((uint16_t*)rbuf)[0] );
537 recv_blk = ntohs( ((uint16_t*)rbuf)[1] );
538 #if ENABLE_TFTP_DEBUG
539 fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk);
541 if (opcode == TFTP_ERROR) {
542 static const char errcode_str[] ALIGN1 =
548 "unknown transfer id\0"
549 "file already exists\0"
553 const char *msg = "";
555 if (len > 4 && rbuf[4] != '\0') {
557 rbuf[io_bufsize - 1] = '\0'; /* paranoia */
558 } else if (recv_blk <= 8) {
559 msg = nth_string(errcode_str, recv_blk);
561 bb_error_msg("server error: (%u) %s", recv_blk, msg);
565 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
568 if (opcode == TFTP_OACK) {
569 /* server seems to support options */
572 res = tftp_get_option("blksize", &rbuf[2], len - 2);
574 blksize = tftp_blksize_check(res, blksize);
576 G_error_pkt_reason = ERR_BAD_OPT;
579 io_bufsize = blksize + 4;
581 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
582 if (remote_file && G.size == 0) { /* if we don't know it yet */
583 res = tftp_get_option("tsize", &rbuf[2], len - 2);
585 G.size = bb_strtoull(res, NULL, 10);
587 tftp_progress_init();
591 if (CMD_GET(option_mask32)) {
592 /* We'll send ACK for OACK,
593 * such ACK has "block no" of 0 */
599 * "An option not acknowledged by the server
600 * must be ignored by the client and server
601 * as if it were never requested." */
602 if (blksize != TFTP_BLKSIZE_DEFAULT)
603 bb_error_msg("falling back to blocksize "TFTP_BLKSIZE_DEFAULT_STR);
604 blksize = TFTP_BLKSIZE_DEFAULT;
605 io_bufsize = TFTP_BLKSIZE_DEFAULT + 4;
608 /* block_nr is already advanced to next block# we expect
609 * to get / block# we are about to send next time */
611 if (CMD_GET(option_mask32) && (opcode == TFTP_DATA)) {
612 if (recv_blk == block_nr) {
613 int sz = full_write(local_fd, &rbuf[4], len - 4);
615 strcpy(G_error_pkt_str, bb_msg_write_error);
616 G_error_pkt_reason = ERR_WRITE;
622 IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += sz;)
623 continue; /* send ACK */
625 /* Disabled to cope with servers with Sorcerer's Apprentice Syndrome */
627 if (recv_blk == (block_nr - 1)) {
628 /* Server lost our TFTP_ACK. Resend it */
635 if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) {
636 /* did peer ACK our last DATA pkt? */
637 if (recv_blk == (uint16_t) (block_nr - 1)) {
640 continue; /* send next block */
643 /* Awww... recv'd packet is not recognized! */
645 /* why recv_again? - rfc1123 says:
646 * "The sender (i.e., the side originating the DATA packets)
647 * must never resend the current DATA packet on receipt
648 * of a duplicate ACK".
649 * DATA pkts are resent ONLY on timeout.
650 * Thus "goto send_again" will ba a bad mistake above.
652 * http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome
654 } /* end of "while (1)" */
656 if (ENABLE_FEATURE_CLEAN_UP) {
662 return finished == 0; /* returns 1 on failure */
665 strcpy(G_error_pkt_str, bb_msg_read_error);
667 if (G_error_pkt_str[0])
668 bb_error_msg("%s", G_error_pkt_str);
669 G.error_pkt[1] = TFTP_ERROR;
670 xsendto(socket_fd, G.error_pkt, 4 + 1 + strlen(G_error_pkt_str),
671 &peer_lsa->u.sa, peer_lsa->len);
678 int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
679 int tftp_main(int argc UNUSED_PARAM, char **argv)
681 len_and_sockaddr *peer_lsa;
682 const char *local_file = NULL;
683 const char *remote_file = NULL;
684 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
685 const char *blksize_str = TFTP_BLKSIZE_DEFAULT_STR;
694 /* -p or -g is mandatory, and they are mutually exclusive */
695 opt_complementary = "" IF_FEATURE_TFTP_GET("g:") IF_FEATURE_TFTP_PUT("p:")
696 IF_GETPUT("g--p:p--g:");
698 IF_GETPUT(opt =) getopt32(argv,
699 IF_FEATURE_TFTP_GET("g") IF_FEATURE_TFTP_PUT("p")
700 "l:r:" IF_FEATURE_TFTP_BLOCKSIZE("b:"),
701 &local_file, &remote_file
702 IF_FEATURE_TFTP_BLOCKSIZE(, &blksize_str));
705 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
706 /* Check if the blksize is valid:
707 * RFC2348 says between 8 and 65464 */
708 blksize = tftp_blksize_check(blksize_str, 65564);
710 //bb_error_msg("bad block size");
717 const char *slash = strrchr(remote_file, '/');
718 local_file = slash ? slash + 1 : remote_file;
721 remote_file = local_file;
724 /* Error if filename or host is not known */
725 if (!remote_file || !argv[0])
728 port = bb_lookup_port(argv[1], "udp", 69);
729 peer_lsa = xhost2sockaddr(argv[0], port);
731 # if ENABLE_TFTP_DEBUG
732 fprintf(stderr, "using server '%s', remote_file '%s', local_file '%s'\n",
733 xmalloc_sockaddr2dotted(&peer_lsa->u.sa),
734 remote_file, local_file);
737 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
738 G.file = remote_file;
740 result = tftp_protocol(
741 NULL /*our_lsa*/, peer_lsa,
742 local_file, remote_file
743 IF_FEATURE_TFTP_BLOCKSIZE(, 1 /* want_transfer_size */)
744 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
746 tftp_progress_done();
748 if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) {
754 #endif /* ENABLE_TFTP */
757 int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
758 int tftpd_main(int argc UNUSED_PARAM, char **argv)
760 len_and_sockaddr *our_lsa;
761 len_and_sockaddr *peer_lsa;
762 char *mode, *user_opt;
763 char *local_file = local_file;
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:l", &user_opt) << 8);
787 if (opt & TFTPD_OPT_l) {
788 openlog(applet_name, LOG_PID, LOG_DAEMON);
789 logmode = LOGMODE_SYSLOG;
791 if (opt & TFTPD_OPT_u) {
792 /* Must be before xchroot */
793 G.pw = xgetpwnam(user_opt);
799 result = recv_from_to(STDIN_FILENO,
800 G.block_buf, sizeof(G.block_buf) + 1,
801 /* ^^^ sizeof+1 to reliably detect oversized input */
803 &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len);
805 error_msg = "malformed packet";
806 opcode = ntohs(*(uint16_t*)G.block_buf);
807 if (result < 4 || result > sizeof(G.block_buf)
808 /*|| G.block_buf[result-1] != '\0' - bug compatibility, see below */
809 || (IF_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */
811 IF_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */
816 /* Some HP PA-RISC firmware always sends fixed 516-byte requests,
817 * with trailing garbage.
818 * Support that by not requiring NUL to be the last byte (see above).
819 * To make strXYZ() ops safe, force NUL termination:
821 G.block_buf_tail[0] = '\0';
823 local_file = G.block_buf + 2;
824 if (local_file[0] == '.' || strstr(local_file, "/.")) {
825 error_msg = "dot in file name";
828 mode = local_file + strlen(local_file) + 1;
829 /* RFC 1350 says mode string is case independent */
830 if (mode >= G.block_buf + result || strcasecmp(mode, "octet") != 0) {
833 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
836 char *opt_str = mode + sizeof("octet");
837 int opt_len = G.block_buf + result - opt_str;
839 res = tftp_get_option("blksize", opt_str, opt_len);
841 blksize = tftp_blksize_check(res, 65564);
843 G_error_pkt_reason = ERR_BAD_OPT;
844 /* will just send error pkt */
848 if (opcode != TFTP_WRQ /* download? */
849 /* did client ask us about file size? */
850 && tftp_get_option("tsize", opt_str, opt_len)
852 want_transfer_size = 1;
858 if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) {
859 if (opt & TFTPD_OPT_r) {
860 /* This would mean "disk full" - not true */
861 /*G_error_pkt_reason = ERR_WRITE;*/
862 error_msg = bb_msg_write_error;
865 IF_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */
867 IF_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */
870 /* NB: if G_error_pkt_str or G_error_pkt_reason is set up,
871 * tftp_protocol() just sends one error pkt and returns */
874 close(STDIN_FILENO); /* close old, possibly wildcard socket */
875 /* tftp_protocol() will create new one, bound to particular local IP */
876 result = tftp_protocol(
878 local_file IF_TFTP(, NULL /*remote_file*/)
879 IF_FEATURE_TFTP_BLOCKSIZE(, want_transfer_size)
880 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
885 strcpy(G_error_pkt_str, error_msg);
889 #endif /* ENABLE_TFTPD */
891 #endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */