1/* vi: set sw=4 ts=4: */ 2/* 3 * A simple tftp client/server for busybox. 4 * Tries to follow RFC1350. 5 * Only "octet" mode supported. 6 * Optional blocksize negotiation (RFC2347 + RFC2348) 7 * 8 * Copyright (C) 2001 Magnus Damm <damm@opensource.se> 9 * 10 * Parts of the code based on: 11 * 12 * atftp: Copyright (C) 2000 Jean-Pierre Lefebvre <helix@step.polymtl.ca> 13 * and Remi Lefebvre <remi@debian.org> 14 * 15 * utftp: Copyright (C) 1999 Uwe Ohse <uwe@ohse.de> 16 * 17 * tftpd added by Denys Vlasenko & Vladimir Dronnikov 18 * 19 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. 20 */ 21#include "libbb.h" 22 23#if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT 24 25#define TFTP_BLKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */ 26#define TFTP_BLKSIZE_DEFAULT_STR "512" 27/* Was 50 ms but users asked to bump it up a bit */ 28#define TFTP_TIMEOUT_MS 100 29#define TFTP_MAXTIMEOUT_MS 2000 30#define TFTP_NUM_RETRIES 12 /* number of backed-off retries */ 31 32/* opcodes we support */ 33#define TFTP_RRQ 1 34#define TFTP_WRQ 2 35#define TFTP_DATA 3 36#define TFTP_ACK 4 37#define TFTP_ERROR 5 38#define TFTP_OACK 6 39 40/* error codes sent over network (we use only 0, 1, 3 and 8) */ 41/* generic (error message is included in the packet) */ 42#define ERR_UNSPEC 0 43#define ERR_NOFILE 1 44#define ERR_ACCESS 2 45/* disk full or allocation exceeded */ 46#define ERR_WRITE 3 47#define ERR_OP 4 48#define ERR_BAD_ID 5 49#define ERR_EXIST 6 50#define ERR_BAD_USER 7 51#define ERR_BAD_OPT 8 52 53/* masks coming from getopt32 */ 54enum { 55 TFTP_OPT_GET = (1 << 0), 56 TFTP_OPT_PUT = (1 << 1), 57 /* pseudo option: if set, it's tftpd */ 58 TFTPD_OPT = (1 << 7) * ENABLE_TFTPD, 59 TFTPD_OPT_r = (1 << 8) * ENABLE_TFTPD, 60 TFTPD_OPT_c = (1 << 9) * ENABLE_TFTPD, 61 TFTPD_OPT_u = (1 << 10) * ENABLE_TFTPD, 62}; 63 64#if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT 65#define IF_GETPUT(...) 66#define CMD_GET(cmd) 1 67#define CMD_PUT(cmd) 0 68#elif !ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT 69#define IF_GETPUT(...) 70#define CMD_GET(cmd) 0 71#define CMD_PUT(cmd) 1 72#else 73#define IF_GETPUT(...) __VA_ARGS__ 74#define CMD_GET(cmd) ((cmd) & TFTP_OPT_GET) 75#define CMD_PUT(cmd) ((cmd) & TFTP_OPT_PUT) 76#endif 77/* NB: in the code below 78 * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive 79 */ 80 81 82struct globals { 83 /* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */ 84 uint8_t error_pkt[4 + 32]; 85 char *user_opt; 86 /* used in tftpd_main(), a bit big for stack: */ 87 char block_buf[TFTP_BLKSIZE_DEFAULT]; 88#if ENABLE_FEATURE_TFTP_PROGRESS_BAR 89 off_t pos; 90 off_t size; 91 const char *file; 92 bb_progress_t pmt; 93#endif 94} FIX_ALIASING; 95#define G (*(struct globals*)&bb_common_bufsiz1) 96struct BUG_G_too_big { 97 char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1]; 98}; 99#define block_buf (G.block_buf ) 100#define user_opt (G.user_opt ) 101#define error_pkt (G.error_pkt ) 102#define INIT_G() do { } while (0) 103 104#define error_pkt_reason (error_pkt[3]) 105#define error_pkt_str (error_pkt + 4) 106 107#if ENABLE_FEATURE_TFTP_PROGRESS_BAR 108/* SIGALRM logic nicked from the wget applet */ 109static void progress_meter(int flag) 110{ 111 /* We can be called from signal handler */ 112 int save_errno = errno; 113 114 if (flag == -1) { /* first call to progress_meter */ 115 bb_progress_init(&G.pmt); 116 } 117 118 bb_progress_update(&G.pmt, G.file, 0, G.pos, G.size); 119 120 if (flag == 0) { 121 /* last call to progress_meter */ 122 alarm(0); 123 bb_putchar_stderr('\n'); 124 } else { 125 if (flag == -1) { /* first call to progress_meter */ 126 signal_SA_RESTART_empty_mask(SIGALRM, progress_meter); 127 } 128 alarm(1); 129 } 130 131 errno = save_errno; 132} 133static void tftp_progress_init(void) 134{ 135 progress_meter(-1); 136} 137static void tftp_progress_done(void) 138{ 139 if (G.pmt.inited) 140 progress_meter(0); 141} 142#else 143# define tftp_progress_init() ((void)0) 144# define tftp_progress_done() ((void)0) 145#endif 146 147#if ENABLE_FEATURE_TFTP_BLOCKSIZE 148 149static int tftp_blksize_check(const char *blksize_str, int maxsize) 150{ 151 /* Check if the blksize is valid: 152 * RFC2348 says between 8 and 65464, 153 * but our implementation makes it impossible 154 * to use blksizes smaller than 22 octets. */ 155 unsigned blksize = bb_strtou(blksize_str, NULL, 10); 156 if (errno 157 || (blksize < 24) || (blksize > maxsize) 158 ) { 159 bb_error_msg("bad blocksize '%s'", blksize_str); 160 return -1; 161 } 162# if ENABLE_TFTP_DEBUG 163 bb_error_msg("using blksize %u", blksize); 164# endif 165 return blksize; 166} 167 168static char *tftp_get_option(const char *option, char *buf, int len) 169{ 170 int opt_val = 0; 171 int opt_found = 0; 172 int k; 173 174 /* buf points to: 175 * "opt_name<NUL>opt_val<NUL>opt_name2<NUL>opt_val2<NUL>..." */ 176 177 while (len > 0) { 178 /* Make sure options are terminated correctly */ 179 for (k = 0; k < len; k++) { 180 if (buf[k] == '\0') { 181 goto nul_found; 182 } 183 } 184 return NULL; 185 nul_found: 186 if (opt_val == 0) { /* it's "name" part */ 187 if (strcasecmp(buf, option) == 0) { 188 opt_found = 1; 189 } 190 } else if (opt_found) { 191 return buf; 192 } 193 194 k++; 195 buf += k; 196 len -= k; 197 opt_val ^= 1; 198 } 199 200 return NULL; 201} 202 203#endif 204 205static int tftp_protocol( 206 /* NULL if tftp, !NULL if tftpd: */ 207 len_and_sockaddr *our_lsa, 208 len_and_sockaddr *peer_lsa, 209 const char *local_file 210 IF_TFTP(, const char *remote_file) 211#if !ENABLE_TFTP 212# define remote_file NULL 213#endif 214 /* 1 for tftp; 1/0 for tftpd depending whether client asked about it: */ 215 IF_FEATURE_TFTP_BLOCKSIZE(, int want_transfer_size) 216 IF_FEATURE_TFTP_BLOCKSIZE(, int blksize)) 217{ 218#if !ENABLE_FEATURE_TFTP_BLOCKSIZE 219 enum { blksize = TFTP_BLKSIZE_DEFAULT }; 220#endif 221 222 struct pollfd pfd[1]; 223#define socket_fd (pfd[0].fd) 224 int len; 225 int send_len; 226 IF_FEATURE_TFTP_BLOCKSIZE(smallint expect_OACK = 0;) 227 smallint finished = 0; 228 uint16_t opcode; 229 uint16_t block_nr; 230 uint16_t recv_blk; 231 int open_mode, local_fd; 232 int retries, waittime_ms; 233 int io_bufsize = blksize + 4; 234 char *cp; 235 /* Can't use RESERVE_CONFIG_BUFFER here since the allocation 236 * size varies meaning BUFFERS_GO_ON_STACK would fail. 237 * 238 * We must keep the transmit and receive buffers separate 239 * in case we rcv a garbage pkt - we need to rexmit the last pkt. 240 */ 241 char *xbuf = xmalloc(io_bufsize); 242 char *rbuf = xmalloc(io_bufsize); 243 244 socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0); 245 setsockopt_reuseaddr(socket_fd); 246 247 if (!ENABLE_TFTP || our_lsa) { /* tftpd */ 248 /* Create a socket which is: 249 * 1. bound to IP:port peer sent 1st datagram to, 250 * 2. connected to peer's IP:port 251 * This way we will answer from the IP:port peer 252 * expects, will not get any other packets on 253 * the socket, and also plain read/write will work. */ 254 xbind(socket_fd, &our_lsa->u.sa, our_lsa->len); 255 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len); 256 257 /* Is there an error already? Send pkt and bail out */ 258 if (error_pkt_reason || error_pkt_str[0]) 259 goto send_err_pkt; 260 261 if (user_opt) { 262 struct passwd *pw = xgetpwnam(user_opt); 263 change_identity(pw); /* initgroups, setgid, setuid */ 264 } 265 } 266 267 /* Prepare open mode */ 268 if (CMD_PUT(option_mask32)) { 269 open_mode = O_RDONLY; 270 } else { 271 open_mode = O_WRONLY | O_TRUNC | O_CREAT; 272#if ENABLE_TFTPD 273 if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) { 274 /* tftpd without -c */ 275 open_mode = O_WRONLY | O_TRUNC; 276 } 277#endif 278 } 279 280 /* Examples of network traffic. 281 * Note two cases when ACKs with block# of 0 are sent. 282 * 283 * Download without options: 284 * tftp -> "\0\1FILENAME\0octet\0" 285 * "\0\3\0\1FILEDATA..." <- tftpd 286 * tftp -> "\0\4\0\1" 287 * ... 288 * Download with option of blksize 16384: 289 * tftp -> "\0\1FILENAME\0octet\0blksize\00016384\0" 290 * "\0\6blksize\00016384\0" <- tftpd 291 * tftp -> "\0\4\0\0" 292 * "\0\3\0\1FILEDATA..." <- tftpd 293 * tftp -> "\0\4\0\1" 294 * ... 295 * Upload without options: 296 * tftp -> "\0\2FILENAME\0octet\0" 297 * "\0\4\0\0" <- tftpd 298 * tftp -> "\0\3\0\1FILEDATA..." 299 * "\0\4\0\1" <- tftpd 300 * ... 301 * Upload with option of blksize 16384: 302 * tftp -> "\0\2FILENAME\0octet\0blksize\00016384\0" 303 * "\0\6blksize\00016384\0" <- tftpd 304 * tftp -> "\0\3\0\1FILEDATA..." 305 * "\0\4\0\1" <- tftpd 306 * ... 307 */ 308 block_nr = 1; 309 cp = xbuf + 2; 310 311 if (!ENABLE_TFTP || our_lsa) { /* tftpd */ 312 /* Open file (must be after changing user) */ 313 local_fd = open(local_file, open_mode, 0666); 314 if (local_fd < 0) { 315 error_pkt_reason = ERR_NOFILE; 316 strcpy((char*)error_pkt_str, "can't open file"); 317 goto send_err_pkt; 318 } 319/* gcc 4.3.1 would NOT optimize it out as it should! */ 320#if ENABLE_FEATURE_TFTP_BLOCKSIZE 321 if (blksize != TFTP_BLKSIZE_DEFAULT || want_transfer_size) { 322 /* Create and send OACK packet. */ 323 /* For the download case, block_nr is still 1 - 324 * we expect 1st ACK from peer to be for (block_nr-1), 325 * that is, for "block 0" which is our OACK pkt */ 326 opcode = TFTP_OACK; 327 goto add_blksize_opt; 328 } 329#endif 330 if (CMD_GET(option_mask32)) { 331 /* It's upload and we don't send OACK. 332 * We must ACK 1st packet (with filename) 333 * as if it is "block 0" */ 334 block_nr = 0; 335 } 336 337 } else { /* tftp */ 338 /* Open file (must be after changing user) */ 339 local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO; 340 if (NOT_LONE_DASH(local_file)) 341 local_fd = xopen(local_file, open_mode); 342/* Removing #if, or using if() statement instead of #if may lead to 343 * "warning: null argument where non-null required": */ 344#if ENABLE_TFTP 345 /* tftp */ 346 347 /* We can't (and don't really need to) bind the socket: 348 * we don't know from which local IP datagrams will be sent, 349 * but kernel will pick the same IP every time (unless routing 350 * table is changed), thus peer will see dgrams consistently 351 * coming from the same IP. 352 * We would like to connect the socket, but since peer's 353 * UDP code can be less perfect than ours, _peer's_ IP:port 354 * in replies may differ from IP:port we used to send 355 * our first packet. We can connect() only when we get 356 * first reply. */ 357 358 /* build opcode */ 359 opcode = TFTP_WRQ; 360 if (CMD_GET(option_mask32)) { 361 opcode = TFTP_RRQ; 362 } 363 /* add filename and mode */ 364 /* fill in packet if the filename fits into xbuf */ 365 len = strlen(remote_file) + 1; 366 if (2 + len + sizeof("octet") >= io_bufsize) { 367 bb_error_msg("remote filename is too long"); 368 goto ret; 369 } 370 strcpy(cp, remote_file); 371 cp += len; 372 /* add "mode" part of the packet */ 373 strcpy(cp, "octet"); 374 cp += sizeof("octet"); 375 376# if ENABLE_FEATURE_TFTP_BLOCKSIZE 377 if (blksize == TFTP_BLKSIZE_DEFAULT && !want_transfer_size) 378 goto send_pkt; 379 380 /* Need to add option to pkt */ 381 if ((&xbuf[io_bufsize - 1] - cp) < sizeof("blksize NNNNN tsize ") + sizeof(off_t)*3) { 382 bb_error_msg("remote filename is too long"); 383 goto ret; 384 } 385 expect_OACK = 1; 386# endif 387#endif /* ENABLE_TFTP */ 388 389#if ENABLE_FEATURE_TFTP_BLOCKSIZE 390 add_blksize_opt: 391 if (blksize != TFTP_BLKSIZE_DEFAULT) { 392 /* add "blksize", <nul>, blksize, <nul> */ 393 strcpy(cp, "blksize"); 394 cp += sizeof("blksize"); 395 cp += snprintf(cp, 6, "%d", blksize) + 1; 396 } 397 if (want_transfer_size) { 398 /* add "tsize", <nul>, size, <nul> (see RFC2349) */ 399 /* if tftp and downloading, we send "0" (since we opened local_fd with O_TRUNC) 400 * and this makes server to send "tsize" option with the size */ 401 /* if tftp and uploading, we send file size (maybe dont, to not confuse old servers???) */ 402 /* if tftpd and downloading, we are answering to client's request */ 403 /* if tftpd and uploading: !want_transfer_size, this code is not executed */ 404 struct stat st; 405 strcpy(cp, "tsize"); 406 cp += sizeof("tsize"); 407 st.st_size = 0; 408 fstat(local_fd, &st); 409 cp += sprintf(cp, "%"OFF_FMT"u", (off_t)st.st_size) + 1; 410# if ENABLE_FEATURE_TFTP_PROGRESS_BAR 411 /* Save for progress bar. If 0 (tftp downloading), 412 * we look at server's reply later */ 413 G.size = st.st_size; 414 if (remote_file && st.st_size) 415 tftp_progress_init(); 416# endif 417 } 418#endif 419 /* First packet is built, so skip packet generation */ 420 goto send_pkt; 421 } 422 423 /* Using mostly goto's - continue/break will be less clear 424 * in where we actually jump to */ 425 while (1) { 426 /* Build ACK or DATA */ 427 cp = xbuf + 2; 428 *((uint16_t*)cp) = htons(block_nr); 429 cp += 2; 430 block_nr++; 431 opcode = TFTP_ACK; 432 if (CMD_PUT(option_mask32)) { 433 opcode = TFTP_DATA; 434 len = full_read(local_fd, cp, blksize); 435 if (len < 0) { 436 goto send_read_err_pkt; 437 } 438 if (len != blksize) { 439 finished = 1; 440 } 441 cp += len; 442 } 443 send_pkt: 444 /* Send packet */ 445 *((uint16_t*)xbuf) = htons(opcode); /* fill in opcode part */ 446 send_len = cp - xbuf; 447 /* NB: send_len value is preserved in code below 448 * for potential resend */ 449 450 retries = TFTP_NUM_RETRIES; /* re-initialize */ 451 waittime_ms = TFTP_TIMEOUT_MS; 452 453 send_again: 454#if ENABLE_TFTP_DEBUG 455 fprintf(stderr, "sending %u bytes\n", send_len); 456 for (cp = xbuf; cp < &xbuf[send_len]; cp++) 457 fprintf(stderr, "%02x ", (unsigned char) *cp); 458 fprintf(stderr, "\n"); 459#endif 460 xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len); 461 462#if ENABLE_FEATURE_TFTP_PROGRESS_BAR 463 if (ENABLE_TFTP && remote_file) { /* tftp */ 464 G.pos = (block_nr - 1) * (uoff_t)blksize; 465 } 466#endif 467 /* Was it final ACK? then exit */ 468 if (finished && (opcode == TFTP_ACK)) 469 goto ret; 470 471 recv_again: 472 /* Receive packet */ 473 /*pfd[0].fd = socket_fd;*/ 474 pfd[0].events = POLLIN; 475 switch (safe_poll(pfd, 1, waittime_ms)) { 476 default: 477 /*bb_perror_msg("poll"); - done in safe_poll */ 478 goto ret; 479 case 0: 480 retries--; 481 if (retries == 0) { 482 bb_error_msg("timeout"); 483 goto ret; /* no err packet sent */ 484 } 485 486 /* exponential backoff with limit */ 487 waittime_ms += waittime_ms/2; 488 if (waittime_ms > TFTP_MAXTIMEOUT_MS) { 489 waittime_ms = TFTP_MAXTIMEOUT_MS; 490 } 491 492 goto send_again; /* resend last sent pkt */ 493 case 1: 494 if (!our_lsa) { 495 /* tftp (not tftpd!) receiving 1st packet */ 496 our_lsa = ((void*)(ptrdiff_t)-1); /* not NULL */ 497 len = recvfrom(socket_fd, rbuf, io_bufsize, 0, 498 &peer_lsa->u.sa, &peer_lsa->len); 499 /* Our first dgram went to port 69 500 * but reply may come from different one. 501 * Remember and use this new port (and IP) */ 502 if (len >= 0) 503 xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len); 504 } else { 505 /* tftpd, or not the very first packet: 506 * socket is connect()ed, can just read from it. */ 507 /* Don't full_read()! 508 * This is not TCP, one read == one pkt! */ 509 len = safe_read(socket_fd, rbuf, io_bufsize); 510 } 511 if (len < 0) { 512 goto send_read_err_pkt; 513 } 514 if (len < 4) { /* too small? */ 515 goto recv_again; 516 } 517 } 518 519 /* Process recv'ed packet */ 520 opcode = ntohs( ((uint16_t*)rbuf)[0] ); 521 recv_blk = ntohs( ((uint16_t*)rbuf)[1] ); 522#if ENABLE_TFTP_DEBUG 523 fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk); 524#endif 525 if (opcode == TFTP_ERROR) { 526 static const char errcode_str[] ALIGN1 = 527 "\0" 528 "file not found\0" 529 "access violation\0" 530 "disk full\0" 531 "bad operation\0" 532 "unknown transfer id\0" 533 "file already exists\0" 534 "no such user\0" 535 "bad option"; 536 537 const char *msg = ""; 538 539 if (len > 4 && rbuf[4] != '\0') { 540 msg = &rbuf[4]; 541 rbuf[io_bufsize - 1] = '\0'; /* paranoia */ 542 } else if (recv_blk <= 8) { 543 msg = nth_string(errcode_str, recv_blk); 544 } 545 bb_error_msg("server error: (%u) %s", recv_blk, msg); 546 goto ret; 547 } 548 549#if ENABLE_FEATURE_TFTP_BLOCKSIZE 550 if (expect_OACK) { 551 expect_OACK = 0; 552 if (opcode == TFTP_OACK) { 553 /* server seems to support options */ 554 char *res; 555 556 res = tftp_get_option("blksize", &rbuf[2], len - 2); 557 if (res) { 558 blksize = tftp_blksize_check(res, blksize); 559 if (blksize < 0) { 560 error_pkt_reason = ERR_BAD_OPT; 561 goto send_err_pkt; 562 } 563 io_bufsize = blksize + 4; 564 } 565# if ENABLE_FEATURE_TFTP_PROGRESS_BAR 566 if (remote_file && G.size == 0) { /* if we don't know it yet */ 567 res = tftp_get_option("tsize", &rbuf[2], len - 2); 568 if (res) { 569 G.size = bb_strtoull(res, NULL, 10); 570 if (G.size) 571 tftp_progress_init(); 572 } 573 } 574# endif 575 if (CMD_GET(option_mask32)) { 576 /* We'll send ACK for OACK, 577 * such ACK has "block no" of 0 */ 578 block_nr = 0; 579 } 580 continue; 581 } 582 /* rfc2347: 583 * "An option not acknowledged by the server 584 * must be ignored by the client and server 585 * as if it were never requested." */ 586 if (blksize != TFTP_BLKSIZE_DEFAULT) 587 bb_error_msg("falling back to blocksize "TFTP_BLKSIZE_DEFAULT_STR); 588 blksize = TFTP_BLKSIZE_DEFAULT; 589 io_bufsize = TFTP_BLKSIZE_DEFAULT + 4; 590 } 591#endif 592 /* block_nr is already advanced to next block# we expect 593 * to get / block# we are about to send next time */ 594 595 if (CMD_GET(option_mask32) && (opcode == TFTP_DATA)) { 596 if (recv_blk == block_nr) { 597 int sz = full_write(local_fd, &rbuf[4], len - 4); 598 if (sz != len - 4) { 599 strcpy((char*)error_pkt_str, bb_msg_write_error); 600 error_pkt_reason = ERR_WRITE; 601 goto send_err_pkt; 602 } 603 if (sz != blksize) { 604 finished = 1; 605 } 606 continue; /* send ACK */ 607 } 608/* Disabled to cope with servers with Sorcerer's Apprentice Syndrome */ 609#if 0 610 if (recv_blk == (block_nr - 1)) { 611 /* Server lost our TFTP_ACK. Resend it */ 612 block_nr = recv_blk; 613 continue; 614 } 615#endif 616 } 617 618 if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) { 619 /* did peer ACK our last DATA pkt? */ 620 if (recv_blk == (uint16_t) (block_nr - 1)) { 621 if (finished) 622 goto ret; 623 continue; /* send next block */ 624 } 625 } 626 /* Awww... recv'd packet is not recognized! */ 627 goto recv_again; 628 /* why recv_again? - rfc1123 says: 629 * "The sender (i.e., the side originating the DATA packets) 630 * must never resend the current DATA packet on receipt 631 * of a duplicate ACK". 632 * DATA pkts are resent ONLY on timeout. 633 * Thus "goto send_again" will ba a bad mistake above. 634 * See: 635 * http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome 636 */ 637 } /* end of "while (1)" */ 638 ret: 639 if (ENABLE_FEATURE_CLEAN_UP) { 640 close(local_fd); 641 close(socket_fd); 642 free(xbuf); 643 free(rbuf); 644 } 645 return finished == 0; /* returns 1 on failure */ 646 647 send_read_err_pkt: 648 strcpy((char*)error_pkt_str, bb_msg_read_error); 649 send_err_pkt: 650 if (error_pkt_str[0]) 651 bb_error_msg("%s", (char*)error_pkt_str); 652 error_pkt[1] = TFTP_ERROR; 653 xsendto(socket_fd, error_pkt, 4 + 1 + strlen((char*)error_pkt_str), 654 &peer_lsa->u.sa, peer_lsa->len); 655 return EXIT_FAILURE; 656#undef remote_file 657} 658 659#if ENABLE_TFTP 660 661int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; 662int tftp_main(int argc UNUSED_PARAM, char **argv) 663{ 664 len_and_sockaddr *peer_lsa; 665 const char *local_file = NULL; 666 const char *remote_file = NULL; 667# if ENABLE_FEATURE_TFTP_BLOCKSIZE 668 const char *blksize_str = TFTP_BLKSIZE_DEFAULT_STR; 669 int blksize; 670# endif 671 int result; 672 int port; 673 IF_GETPUT(int opt;) 674 675 INIT_G(); 676 677 /* -p or -g is mandatory, and they are mutually exclusive */ 678 opt_complementary = "" IF_FEATURE_TFTP_GET("g:") IF_FEATURE_TFTP_PUT("p:") 679 IF_GETPUT("g--p:p--g:"); 680 681 IF_GETPUT(opt =) getopt32(argv, 682 IF_FEATURE_TFTP_GET("g") IF_FEATURE_TFTP_PUT("p") 683 "l:r:" IF_FEATURE_TFTP_BLOCKSIZE("b:"), 684 &local_file, &remote_file 685 IF_FEATURE_TFTP_BLOCKSIZE(, &blksize_str)); 686 argv += optind; 687 688# if ENABLE_FEATURE_TFTP_BLOCKSIZE 689 /* Check if the blksize is valid: 690 * RFC2348 says between 8 and 65464 */ 691 blksize = tftp_blksize_check(blksize_str, 65564); 692 if (blksize < 0) { 693 //bb_error_msg("bad block size"); 694 return EXIT_FAILURE; 695 } 696# endif 697 698 if (remote_file) { 699 if (!local_file) { 700 const char *slash = strrchr(remote_file, '/'); 701 local_file = slash ? slash + 1 : remote_file; 702 } 703 } else { 704 remote_file = local_file; 705 } 706 707 /* Error if filename or host is not known */ 708 if (!remote_file || !argv[0]) 709 bb_show_usage(); 710 711 port = bb_lookup_port(argv[1], "udp", 69); 712 peer_lsa = xhost2sockaddr(argv[0], port); 713 714# if ENABLE_TFTP_DEBUG 715 fprintf(stderr, "using server '%s', remote_file '%s', local_file '%s'\n", 716 xmalloc_sockaddr2dotted(&peer_lsa->u.sa), 717 remote_file, local_file); 718# endif 719 720# if ENABLE_FEATURE_TFTP_PROGRESS_BAR 721 G.file = remote_file; 722# endif 723 result = tftp_protocol( 724 NULL /*our_lsa*/, peer_lsa, 725 local_file, remote_file 726 IF_FEATURE_TFTP_BLOCKSIZE(, 1 /* want_transfer_size */) 727 IF_FEATURE_TFTP_BLOCKSIZE(, blksize) 728 ); 729 tftp_progress_done(); 730 731 if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) { 732 unlink(local_file); 733 } 734 return result; 735} 736 737#endif /* ENABLE_TFTP */ 738 739#if ENABLE_TFTPD 740int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; 741int tftpd_main(int argc UNUSED_PARAM, char **argv) 742{ 743 len_and_sockaddr *our_lsa; 744 len_and_sockaddr *peer_lsa; 745 char *local_file, *mode; 746 const char *error_msg; 747 int opt, result, opcode; 748 IF_FEATURE_TFTP_BLOCKSIZE(int blksize = TFTP_BLKSIZE_DEFAULT;) 749 IF_FEATURE_TFTP_BLOCKSIZE(int want_transfer_size = 0;) 750 751 INIT_G(); 752 753 our_lsa = get_sock_lsa(STDIN_FILENO); 754 if (!our_lsa) { 755 /* This is confusing: 756 *bb_error_msg_and_die("stdin is not a socket"); 757 * Better: */ 758 bb_show_usage(); 759 /* Help text says that tftpd must be used as inetd service, 760 * which is by far the most usual cause of get_sock_lsa 761 * failure */ 762 } 763 peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len); 764 peer_lsa->len = our_lsa->len; 765 766 /* Shifting to not collide with TFTP_OPTs */ 767 opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:", &user_opt) << 8); 768 argv += optind; 769 if (argv[0]) 770 xchdir(argv[0]); 771 772 result = recv_from_to(STDIN_FILENO, block_buf, sizeof(block_buf), 773 0 /* flags */, 774 &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len); 775 776 error_msg = "malformed packet"; 777 opcode = ntohs(*(uint16_t*)block_buf); 778 if (result < 4 || result >= sizeof(block_buf) 779 || block_buf[result-1] != '\0' 780 || (IF_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */ 781 IF_GETPUT(&&) 782 IF_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */ 783 ) 784 ) { 785 goto err; 786 } 787 local_file = block_buf + 2; 788 if (local_file[0] == '.' || strstr(local_file, "/.")) { 789 error_msg = "dot in file name"; 790 goto err; 791 } 792 mode = local_file + strlen(local_file) + 1; 793 if (mode >= block_buf + result || strcmp(mode, "octet") != 0) { 794 goto err; 795 } 796# if ENABLE_FEATURE_TFTP_BLOCKSIZE 797 { 798 char *res; 799 char *opt_str = mode + sizeof("octet"); 800 int opt_len = block_buf + result - opt_str; 801 if (opt_len > 0) { 802 res = tftp_get_option("blksize", opt_str, opt_len); 803 if (res) { 804 blksize = tftp_blksize_check(res, 65564); 805 if (blksize < 0) { 806 error_pkt_reason = ERR_BAD_OPT; 807 /* will just send error pkt */ 808 goto do_proto; 809 } 810 } 811 if (opcode != TFTP_WRQ /* download? */ 812 /* did client ask us about file size? */ 813 && tftp_get_option("tsize", opt_str, opt_len) 814 ) { 815 want_transfer_size = 1; 816 } 817 } 818 } 819# endif 820 821 if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) { 822 if (opt & TFTPD_OPT_r) { 823 /* This would mean "disk full" - not true */ 824 /*error_pkt_reason = ERR_WRITE;*/ 825 error_msg = bb_msg_write_error; 826 goto err; 827 } 828 IF_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */ 829 } else { 830 IF_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */ 831 } 832 833 /* NB: if error_pkt_str or error_pkt_reason is set up, 834 * tftp_protocol() just sends one error pkt and returns */ 835 836 do_proto: 837 close(STDIN_FILENO); /* close old, possibly wildcard socket */ 838 /* tftp_protocol() will create new one, bound to particular local IP */ 839 result = tftp_protocol( 840 our_lsa, peer_lsa, 841 local_file IF_TFTP(, NULL /*remote_file*/) 842 IF_FEATURE_TFTP_BLOCKSIZE(, want_transfer_size) 843 IF_FEATURE_TFTP_BLOCKSIZE(, blksize) 844 ); 845 846 return result; 847 err: 848 strcpy((char*)error_pkt_str, error_msg); 849 goto do_proto; 850} 851 852#endif /* ENABLE_TFTPD */ 853 854#endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */ 855