1 /* $NetBSD: tftp.c,v 1.4 1997/09/17 16:57:07 drochner Exp $ */ 2 3 /* 4 * Copyright (c) 1996 5 * Matthias Drochner. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed for the NetBSD Project 18 * by Matthias Drochner. 19 * 4. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 /* 35 * Simple TFTP implementation for libsa. 36 * Assumes: 37 * - socket descriptor (int) at dev->d_opendata, dev stored at 38 * open_file->f_devdata 39 * - server host IP in global rootip 40 * Restrictions: 41 * - read only 42 * - lseek only with SEEK_SET or SEEK_CUR 43 * - no big time differences between transfers (<tftp timeout) 44 */ 45 46 #include <sys/types.h> 47 #include <sys/stat.h> 48 #include <netinet/in.h> 49 #include <netinet/udp.h> 50 #include <netinet/in_systm.h> 51 #include <arpa/tftp.h> 52 53 #ifdef LOADER_VERIEXEC 54 #include <verify_file.h> 55 #endif 56 57 #include <string.h> 58 59 #include "stand.h" 60 #include "net.h" 61 #include "netif.h" 62 63 #include "tftp.h" 64 65 struct tftp_handle; 66 struct tftprecv_extra; 67 68 static ssize_t recvtftp(struct iodesc *, void **, void **, time_t, void *); 69 static int tftp_open(const char *, struct open_file *); 70 static int tftp_close(struct open_file *); 71 static int tftp_parse_oack(struct tftp_handle *, char *, size_t); 72 static int tftp_read(struct open_file *, void *, size_t, size_t *); 73 static off_t tftp_seek(struct open_file *, off_t, int); 74 static int tftp_set_blksize(struct tftp_handle *, const char *); 75 static int tftp_stat(struct open_file *, struct stat *); 76 static int tftp_preload(struct open_file *); 77 78 struct fs_ops tftp_fsops = { 79 .fs_name = "tftp", 80 .fs_flags = 0, 81 .fo_open = tftp_open, 82 .fo_close = tftp_close, 83 .fo_read = tftp_read, 84 .fo_write = null_write, 85 .fo_seek = tftp_seek, 86 .fo_stat = tftp_stat, 87 .fo_preload = tftp_preload, 88 .fo_readdir = null_readdir 89 }; 90 91 static int tftpport = 2000; 92 93 /* 94 * The legacy TFTP_BLKSIZE value was SEGSIZE(512). 95 * TFTP_REQUESTED_BLKSIZE of 1428 is (Ethernet MTU, less the TFTP, UDP and 96 * IP header lengths). 97 */ 98 #define TFTP_REQUESTED_BLKSIZE 1428 99 100 /* 101 * Choose a blksize big enough so we can test with Ethernet 102 * Jumbo frames in the future. 103 */ 104 #define TFTP_MAX_BLKSIZE 9008 105 #define TFTP_TRIES 3 106 107 struct tftp_handle { 108 struct iodesc *iodesc; 109 struct iodesc io; 110 int id; 111 ino_t ino; 112 int port; 113 int currblock; /* contents of lastdata */ 114 unsigned int islastblock:1; /* flag */ 115 unsigned int tries:4; /* number of read attempts */ 116 int validsize; 117 int off; 118 char *path; /* saved for re-requests */ 119 unsigned int tftp_blksize; 120 unsigned long tftp_tsize; 121 void *pkt; 122 struct tftphdr *tftp_hdr; 123 char *tftp_cache; 124 bool lastacksent; 125 }; 126 127 struct tftprecv_extra { 128 struct tftp_handle *tftp_handle; 129 unsigned short rtype; /* Received type */ 130 }; 131 132 #define TFTP_MAX_ERRCODE EOPTNEG 133 static const int tftperrors[TFTP_MAX_ERRCODE + 1] = { 134 0, /* NAK */ 135 ENOENT, 136 EPERM, 137 ENOSPC, 138 EINVAL, /* ??? */ 139 EINVAL, /* ??? */ 140 EEXIST, 141 EINVAL, /* ??? */ 142 EINVAL, /* Option negotiation failed. */ 143 }; 144 145 static int tftp_getnextblock(struct tftp_handle *h); 146 147 /* send error message back. */ 148 static void 149 tftp_senderr(struct tftp_handle *h, u_short errcode, const char *msg) 150 { 151 struct { 152 u_char header[HEADER_SIZE]; 153 struct tftphdr t; 154 u_char space[63]; /* +1 from t */ 155 } __packed __aligned(4) wbuf; 156 char *wtail; 157 int len; 158 159 len = strlen(msg); 160 if (len > sizeof(wbuf.space)) 161 len = sizeof(wbuf.space); 162 163 wbuf.t.th_opcode = htons((u_short)ERROR); 164 wbuf.t.th_code = htons(errcode); 165 166 wtail = wbuf.t.th_msg; 167 bcopy(msg, wtail, len); 168 wtail[len] = '\0'; 169 wtail += len + 1; 170 171 sendudp(h->iodesc, &wbuf.t, wtail - (char *)&wbuf.t); 172 } 173 174 static void 175 tftp_sendack(struct tftp_handle *h, u_short block) 176 { 177 struct { 178 u_char header[HEADER_SIZE]; 179 struct tftphdr t; 180 } __packed __aligned(4) wbuf; 181 char *wtail; 182 183 wbuf.t.th_opcode = htons((u_short)ACK); 184 wtail = (char *)&wbuf.t.th_block; 185 wbuf.t.th_block = htons(block); 186 wtail += 2; 187 188 DEBUG_PRINTF(5,("%s: myport=%hu xid=%lu, block=%hu\n", 189 __func__, h->iodesc->myport, h->iodesc->xid, block)); 190 191 sendudp(h->iodesc, &wbuf.t, wtail - (char *)&wbuf.t); 192 } 193 194 static ssize_t 195 recvtftp(struct iodesc *d, void **pkt, void **payload, time_t tleft, 196 void *recv_extra) 197 { 198 struct tftprecv_extra *extra; 199 struct tftp_handle *h; 200 struct tftphdr *t; 201 void *ptr = NULL; 202 ssize_t len; 203 int tftp_error; 204 unsigned short block; 205 206 errno = 0; 207 extra = recv_extra; 208 h = extra->tftp_handle; 209 210 len = readudp(d, &ptr, (void **)&t, tleft); 211 212 if (len < 4) { 213 free(ptr); 214 return (-1); 215 } 216 217 extra->rtype = ntohs(t->th_opcode); 218 block = ntohs(t->th_block); 219 DEBUG_PRINTF(6,("%s: myport=%hu xid=%lu, block=%hu, opcode=%hu\n", 220 __func__, d->myport, d->xid, block, extra->rtype)); 221 switch (extra->rtype) { 222 case DATA: { 223 int got; 224 225 if (block < (u_short)d->xid) { 226 /* 227 * Apparently our ACK was missed, re-send. 228 */ 229 tftp_sendack(h, block); 230 free(ptr); 231 return (-1); 232 } 233 if (block != (u_short)d->xid) { 234 /* 235 * Packet from the future, drop this. 236 */ 237 free(ptr); 238 return (-1); 239 } 240 if (d->xid == 1) { 241 /* 242 * First data packet from new port. 243 */ 244 struct udphdr *uh; 245 uh = (struct udphdr *)t - 1; 246 d->destport = uh->uh_sport; 247 } 248 got = len - (t->th_data - (char *)t); 249 *pkt = ptr; 250 *payload = t; 251 return (got); 252 } 253 case ERROR: 254 tftp_error = ntohs(t->th_code); 255 if ((unsigned)tftp_error > TFTP_MAX_ERRCODE) { 256 printf("illegal tftp error %d\n", tftp_error); 257 errno = EIO; 258 } else { 259 DEBUG_PRINTF(0, ("tftp-error %d\n", tftp_error)); 260 errno = tftperrors[tftp_error]; 261 } 262 free(ptr); 263 /* If we got a NAK return 0, it's usually a directory */ 264 if (tftp_error == 0) 265 return (0); 266 return (-1); 267 case OACK: { 268 struct udphdr *uh; 269 int tftp_oack_len; 270 271 /* 272 * Unexpected OACK. TFTP transfer already in progress. 273 * Drop the pkt. 274 */ 275 if (d->xid != 1) { 276 free(ptr); 277 return (-1); 278 } 279 280 /* 281 * Remember which port this OACK came from, because we need 282 * to send the ACK or errors back to it. 283 */ 284 uh = (struct udphdr *)t - 1; 285 d->destport = uh->uh_sport; 286 287 /* Parse options ACK-ed by the server. */ 288 tftp_oack_len = len - sizeof(t->th_opcode); 289 if (tftp_parse_oack(h, t->th_u.tu_stuff, tftp_oack_len) != 0) { 290 tftp_senderr(h, EOPTNEG, "Malformed OACK"); 291 errno = EIO; 292 free(ptr); 293 return (-1); 294 } 295 *pkt = ptr; 296 *payload = t; 297 return (0); 298 } 299 default: 300 DEBUG_PRINTF(0, ("tftp type %hu not handled\n", extra->rtype)); 301 free(ptr); 302 return (-1); 303 } 304 } 305 306 /* send request, expect first block (or error) */ 307 static int 308 tftp_makereq(struct tftp_handle *h) 309 { 310 struct { 311 u_char header[HEADER_SIZE]; 312 struct tftphdr t; 313 u_char space[FNAME_SIZE + 6]; 314 } __packed __aligned(4) wbuf; 315 struct tftprecv_extra recv_extra; 316 char *wtail; 317 int l; 318 ssize_t res; 319 void *pkt; 320 struct tftphdr *t; 321 char *tftp_blksize = NULL; 322 int blksize_l; 323 324 /* 325 * Allow overriding default TFTP block size by setting 326 * a tftp.blksize environment variable. 327 */ 328 if ((tftp_blksize = getenv("tftp.blksize")) != NULL) { 329 tftp_set_blksize(h, tftp_blksize); 330 } 331 332 wbuf.t.th_opcode = htons((u_short)RRQ); 333 wtail = wbuf.t.th_stuff; 334 l = strlen(h->path); 335 #ifdef TFTP_PREPEND_PATH 336 if (l > FNAME_SIZE - (sizeof(TFTP_PREPEND_PATH) - 1)) 337 return (ENAMETOOLONG); 338 bcopy(TFTP_PREPEND_PATH, wtail, sizeof(TFTP_PREPEND_PATH) - 1); 339 wtail += sizeof(TFTP_PREPEND_PATH) - 1; 340 #else 341 if (l > FNAME_SIZE) 342 return (ENAMETOOLONG); 343 #endif 344 bcopy(h->path, wtail, l + 1); 345 wtail += l + 1; 346 bcopy("octet", wtail, 6); 347 wtail += 6; 348 bcopy("blksize", wtail, 8); 349 wtail += 8; 350 blksize_l = sprintf(wtail, "%d", h->tftp_blksize); 351 wtail += blksize_l + 1; 352 bcopy("tsize", wtail, 6); 353 wtail += 6; 354 bcopy("0", wtail, 2); 355 wtail += 2; 356 357 h->iodesc->myport = htons(h->port + (getsecs() & 0x3ff)); 358 h->iodesc->destport = htons(IPPORT_TFTP); 359 h->iodesc->xid = 1; /* expected block */ 360 361 h->currblock = 0; 362 h->islastblock = 0; 363 h->validsize = 0; 364 365 DEBUG_PRINTF(5,("%s: %s: id=%d port=%d myport=%hu xid=1\n", 366 __func__, h->path, h->id, h->port, ntohs(h->iodesc->myport))); 367 pkt = NULL; 368 recv_extra.tftp_handle = h; 369 res = sendrecv(h->iodesc, &sendudp, &wbuf.t, wtail - (char *)&wbuf.t, 370 &recvtftp, &pkt, (void **)&t, &recv_extra); 371 if (res == -1) { 372 DEBUG_PRINTF(3,("%s: %s: id=%d errno=%d\n", 373 __func__, h->path, h->id, errno)); 374 free(pkt); 375 return (errno); 376 } 377 378 free(h->pkt); 379 h->pkt = pkt; 380 h->tftp_hdr = t; 381 382 if (recv_extra.rtype == OACK) 383 return (tftp_getnextblock(h)); 384 385 /* Server ignored our blksize request, revert to TFTP default. */ 386 h->tftp_blksize = SEGSIZE; 387 388 switch (recv_extra.rtype) { 389 case DATA: { 390 h->currblock = 1; 391 h->validsize = res; 392 h->islastblock = 0; 393 if (res < h->tftp_blksize) { 394 h->islastblock = 1; /* very short file */ 395 tftp_sendack(h, h->currblock); 396 h->lastacksent = true; 397 } 398 return (0); 399 } 400 case ERROR: 401 default: 402 return (errno); 403 } 404 405 } 406 407 /* ack block, expect next */ 408 static int 409 tftp_getnextblock(struct tftp_handle *h) 410 { 411 struct { 412 u_char header[HEADER_SIZE]; 413 struct tftphdr t; 414 } __packed __aligned(4) wbuf; 415 struct tftprecv_extra recv_extra; 416 char *wtail; 417 int res; 418 void *pkt; 419 struct tftphdr *t; 420 421 wbuf.t.th_opcode = htons((u_short)ACK); 422 wtail = (char *)&wbuf.t.th_block; 423 wbuf.t.th_block = htons((u_short)h->currblock); 424 wtail += 2; 425 426 h->iodesc->xid = h->currblock + 1; /* expected block */ 427 428 DEBUG_PRINTF(5,("%s: %s: id=%d port=%d myport=%hu xid=%lu\n", 429 __func__, h->path, h->id, h->port, 430 ntohs(h->iodesc->myport), h->iodesc->xid)); 431 432 pkt = NULL; 433 recv_extra.tftp_handle = h; 434 res = sendrecv(h->iodesc, &sendudp, &wbuf.t, wtail - (char *)&wbuf.t, 435 &recvtftp, &pkt, (void **)&t, &recv_extra); 436 437 if (res == -1) { /* 0 is OK! */ 438 DEBUG_PRINTF(3,("%s: %s: id=%d errno=%d\n", 439 __func__, h->path, h->id, errno)); 440 free(pkt); 441 return (errno); 442 } 443 444 free(h->pkt); 445 h->pkt = pkt; 446 h->tftp_hdr = t; 447 h->currblock++; 448 h->validsize = res; 449 if (res < h->tftp_blksize) 450 h->islastblock = 1; /* EOF */ 451 452 DEBUG_PRINTF(5,("%s: %s: id=%d res=%d blksz=%d last=%d\n", 453 __func__, h->path, h->id, res, h->tftp_blksize, h->islastblock)); 454 455 if (h->islastblock) { 456 /* Send an ACK for the last block */ 457 tftp_sendack(h, h->currblock); 458 } 459 460 return (0); 461 } 462 463 /* 464 * If doing verification we need to handle multiple 465 * files at the same time. 466 */ 467 #define TOPEN_MAX 8 468 static struct tftp_handle *handles[TOPEN_MAX]; 469 470 static int 471 tftp_open(const char *path, struct open_file *f) 472 { 473 struct devdesc *dev; 474 struct tftp_handle *tftpfile; 475 struct iodesc *io; 476 static int lx = 0; 477 int i, x; 478 int res; 479 size_t pathsize; 480 const char *extraslash; 481 482 if (netproto != NET_TFTP) 483 return (EINVAL); 484 485 if (f->f_dev == NULL || f->f_dev->dv_type != DEVT_NET) 486 return (EINVAL); 487 488 tftpfile = NULL; 489 for (x = lx + 1, i = 0; i < TOPEN_MAX; i++, x++) { 490 x %= TOPEN_MAX; 491 if (handles[x] == NULL) { 492 handles[x] = tftpfile = calloc(1, sizeof(*tftpfile)); 493 if (tftpfile == NULL) 494 return (ENOMEM); 495 /* id allows us to clear the slot on close */ 496 tftpfile->id = lx = x; 497 /* port ensures a different session with server */ 498 tftpfile->port = (tftpport + (x * tftpport)) & 0xffff; 499 DEBUG_PRINTF(1, ("%s(%s) id=%d port=%d\n", 500 __func__, path, tftpfile->id, tftpfile->port)); 501 break; 502 } 503 } 504 if (tftpfile == NULL) { 505 DEBUG_PRINTF(1, ("%s: EBUSY\n", __func__)); 506 return (EBUSY); 507 } 508 tftpfile->tftp_blksize = TFTP_REQUESTED_BLKSIZE; 509 dev = f->f_devdata; 510 io = socktodesc(*(int *)(dev->d_opendata)); 511 if (io == NULL) { 512 free(tftpfile); 513 return (EINVAL); 514 } 515 516 memcpy(&tftpfile->io, io, sizeof(tftpfile->io)); 517 io = tftpfile->iodesc = &tftpfile->io; 518 io->destip = rootip; 519 tftpfile->off = 0; 520 pathsize = (strlen(rootpath) + 1 + strlen(path) + 1) * sizeof(char); 521 tftpfile->path = malloc(pathsize); 522 if (tftpfile->path == NULL) { 523 free(tftpfile); 524 return (ENOMEM); 525 } 526 if (rootpath[strlen(rootpath) - 1] == '/' || path[0] == '/') 527 extraslash = ""; 528 else 529 extraslash = "/"; 530 if (rootpath[0] == '/' && rootpath[1] == '\0' && path[0] == '/') 531 res = strlcpy(tftpfile->path, path, pathsize); 532 else 533 res = snprintf(tftpfile->path, pathsize, "%s%s%s", 534 rootpath, extraslash, path); 535 if (res < 0 || res > pathsize) { 536 free(tftpfile->path); 537 free(tftpfile); 538 return (ENOMEM); 539 } 540 541 res = tftp_makereq(tftpfile); 542 543 if (res) { 544 handles[tftpfile->id] = NULL; 545 free(tftpfile->path); 546 free(tftpfile->pkt); 547 free(tftpfile); 548 return (res); 549 } 550 f->f_fsdata = tftpfile; 551 return (0); 552 } 553 554 static int 555 tftp_read(struct open_file *f, void *addr, size_t size, 556 size_t *resid /* out */) 557 { 558 struct tftp_handle *tftpfile; 559 size_t res; 560 int rc; 561 562 rc = 0; 563 res = size; 564 tftpfile = f->f_fsdata; 565 566 /* Make sure we will not read past file end */ 567 if (tftpfile->tftp_tsize > 0 && 568 tftpfile->off + size > tftpfile->tftp_tsize) { 569 size = tftpfile->tftp_tsize - tftpfile->off; 570 } 571 572 if (tftpfile->tftp_cache != NULL) { 573 bcopy(tftpfile->tftp_cache + tftpfile->off, 574 addr, size); 575 576 addr = (char *)addr + size; 577 tftpfile->off += size; 578 res -= size; 579 goto out; 580 } 581 582 while (size > 0) { 583 int needblock, count; 584 585 twiddle(32); 586 587 needblock = tftpfile->off / tftpfile->tftp_blksize + 1; 588 589 if (tftpfile->currblock > needblock) { /* seek backwards */ 590 tftp_senderr(tftpfile, 0, "No error: read aborted"); 591 rc = tftp_makereq(tftpfile); 592 if (rc != 0) 593 break; 594 } 595 596 while (tftpfile->currblock < needblock) { 597 598 rc = tftp_getnextblock(tftpfile); 599 if (rc) { /* no answer */ 600 DEBUG_PRINTF(0, ("tftp: read error\n")); 601 if (tftpfile->tries > TFTP_TRIES) { 602 return (rc); 603 } else { 604 tftpfile->tries++; 605 tftp_makereq(tftpfile); 606 } 607 } 608 if (tftpfile->islastblock) 609 break; 610 } 611 612 if (tftpfile->currblock == needblock) { 613 int offinblock, inbuffer; 614 615 offinblock = tftpfile->off % tftpfile->tftp_blksize; 616 617 inbuffer = tftpfile->validsize - offinblock; 618 if (inbuffer < 0) { 619 DEBUG_PRINTF(0, ("tftp: invalid offset %d\n", 620 tftpfile->off)); 621 return (EINVAL); 622 } 623 count = (size < inbuffer ? size : inbuffer); 624 bcopy(tftpfile->tftp_hdr->th_data + offinblock, 625 addr, count); 626 627 addr = (char *)addr + count; 628 tftpfile->off += count; 629 size -= count; 630 res -= count; 631 632 if ((tftpfile->islastblock) && (count == inbuffer)) 633 break; /* EOF */ 634 } else { 635 DEBUG_PRINTF(0, ("tftp: block %d not found\n", needblock)); 636 return (EINVAL); 637 } 638 639 } 640 641 out: 642 DEBUG_PRINTF(4, ("%s(%s) res=%ld\n", __func__, tftpfile->path, 643 (tftpfile->tftp_tsize - tftpfile->off))); 644 if (resid != NULL) 645 *resid = res; 646 return (rc); 647 } 648 649 static int 650 tftp_close(struct open_file *f) 651 { 652 struct tftp_handle *tftpfile; 653 tftpfile = f->f_fsdata; 654 655 if (tftpfile->lastacksent == false) 656 tftp_senderr(tftpfile, 0, "No error: file closed"); 657 658 if (tftpfile) { 659 DEBUG_PRINTF(1, ("%s(%d): %s\n", __func__, 660 tftpfile->id, tftpfile->path)); 661 handles[tftpfile->id] = NULL; 662 free(tftpfile->path); 663 free(tftpfile->pkt); 664 free(tftpfile->tftp_cache); 665 free(tftpfile); 666 } 667 return (0); 668 } 669 670 671 static int 672 tftp_stat(struct open_file *f, struct stat *sb) 673 { 674 struct tftp_handle *tftpfile; 675 tftpfile = f->f_fsdata; 676 677 sb->st_mode = 0444 | S_IFREG; 678 sb->st_nlink = 1; 679 sb->st_uid = 0; 680 sb->st_gid = 0; 681 sb->st_size = tftpfile->tftp_tsize; 682 sb->st_mtime = 0; 683 #ifdef LOADER_VERIEXEC 684 /* libsecureboot needs st_dev and st_ino at minimum; 685 * we need to fake something that will be close enough to 686 * unique. 687 */ 688 sb->st_dev = (dev_t)tftpfile->iodesc->destip.s_addr; 689 /* we don't want to compute this more than once */ 690 if (tftpfile->ino == 0) { 691 union { 692 unsigned char digest[SHA_DIGEST_LENGTH]; 693 ino_t ino; 694 } u; 695 696 hash_string(tftpfile->path, 0, u.digest, sizeof(u.digest)); 697 698 tftpfile->ino = u.ino & 0x7fffffff; 699 DEBUG_PRINTF(2,("%s(%s) dev=%lu ino=%lu\n", __func__, 700 tftpfile->path, (unsigned long)sb->st_dev, 701 (unsigned long)tftpfile->ino)); 702 } 703 sb->st_ino = tftpfile->ino; 704 #endif 705 return (0); 706 } 707 708 static off_t 709 tftp_seek(struct open_file *f, off_t offset, int where) 710 { 711 struct tftp_handle *tftpfile; 712 tftpfile = f->f_fsdata; 713 714 switch (where) { 715 case SEEK_SET: 716 tftpfile->off = offset; 717 break; 718 case SEEK_CUR: 719 tftpfile->off += offset; 720 break; 721 default: 722 errno = EOFFSET; 723 return (-1); 724 } 725 return (tftpfile->off); 726 } 727 728 static int 729 tftp_preload(struct open_file *f) 730 { 731 struct tftp_handle *tftpfile; 732 char *cache; 733 int rc; 734 #ifdef TFTP_DEBUG 735 time_t start, end; 736 #endif 737 738 tftpfile = f->f_fsdata; 739 cache = malloc(sizeof(char) * tftpfile->tftp_tsize); 740 if (cache == NULL) { 741 printf("Couldn't allocate %ju bytes for preload caching" 742 ", disabling caching\n", 743 (uintmax_t)sizeof(char) * tftpfile->tftp_tsize); 744 return (-1); 745 } 746 747 #ifdef TFTP_DEBUG 748 start = getsecs(); 749 printf("Preloading %s ", tftpfile->path); 750 #endif 751 if (tftpfile->currblock == 1) 752 bcopy(tftpfile->tftp_hdr->th_data, 753 cache, 754 tftpfile->validsize); 755 else 756 tftpfile->currblock = 0; 757 758 while (tftpfile->islastblock == 0) { 759 twiddle(32); 760 rc = tftp_getnextblock(tftpfile); 761 if (rc) { 762 free(cache); 763 printf("Got TFTP error %d, disabling caching\n", rc); 764 return (rc); 765 } 766 bcopy(tftpfile->tftp_hdr->th_data, 767 cache + (tftpfile->tftp_blksize * (tftpfile->currblock - 1)), 768 tftpfile->validsize); 769 } 770 #ifdef TFTP_DEBUG 771 end = getsecs(); 772 printf("\nPreloaded %s (%ju bytes) during %jd seconds\n", 773 tftpfile->path, (intmax_t)tftpfile->tftp_tsize, 774 (intmax_t)end - start); 775 #endif 776 777 tftpfile->tftp_cache = cache; 778 return (0); 779 } 780 781 static int 782 tftp_set_blksize(struct tftp_handle *h, const char *str) 783 { 784 char *endptr; 785 int new_blksize; 786 int ret = 0; 787 788 if (h == NULL || str == NULL) 789 return (ret); 790 791 new_blksize = 792 (unsigned int)strtol(str, &endptr, 0); 793 794 /* 795 * Only accept blksize value if it is numeric. 796 * RFC2348 specifies that acceptable values are 8-65464. 797 * Let's choose a limit less than MAXRSPACE. 798 */ 799 if (*endptr == '\0' && new_blksize >= 8 && 800 new_blksize <= TFTP_MAX_BLKSIZE) { 801 h->tftp_blksize = new_blksize; 802 ret = 1; 803 } 804 805 return (ret); 806 } 807 808 /* 809 * In RFC2347, the TFTP Option Acknowledgement package (OACK) 810 * is used to acknowledge a client's option negotiation request. 811 * The format of an OACK packet is: 812 * +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+ 813 * | opc | opt1 | 0 | value1 | 0 | optN | 0 | valueN | 0 | 814 * +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+ 815 * 816 * opc 817 * The opcode field contains a 6, for Option Acknowledgment. 818 * 819 * opt1 820 * The first option acknowledgment, copied from the original 821 * request. 822 * 823 * value1 824 * The acknowledged value associated with the first option. If 825 * and how this value may differ from the original request is 826 * detailed in the specification for the option. 827 * 828 * optN, valueN 829 * The final option/value acknowledgment pair. 830 */ 831 static int 832 tftp_parse_oack(struct tftp_handle *h, char *buf, size_t len) 833 { 834 /* 835 * We parse the OACK strings into an array 836 * of name-value pairs. 837 */ 838 char *tftp_options[128] = { 0 }; 839 char *val = buf; 840 int i = 0; 841 int option_idx = 0; 842 int blksize_is_set = 0; 843 int tsize = 0; 844 845 unsigned int orig_blksize; 846 847 while (option_idx < 128 && i < len) { 848 if (buf[i] == '\0') { 849 if (&buf[i] > val) { 850 tftp_options[option_idx] = val; 851 val = &buf[i] + 1; 852 ++option_idx; 853 } 854 } 855 ++i; 856 } 857 858 /* Save the block size we requested for sanity check later. */ 859 orig_blksize = h->tftp_blksize; 860 861 /* 862 * Parse individual TFTP options. 863 * * "blksize" is specified in RFC2348. 864 * * "tsize" is specified in RFC2349. 865 */ 866 for (i = 0; i < option_idx; i += 2) { 867 if (strcasecmp(tftp_options[i], "blksize") == 0) { 868 if (i + 1 < option_idx) 869 blksize_is_set = 870 tftp_set_blksize(h, tftp_options[i + 1]); 871 } else if (strcasecmp(tftp_options[i], "tsize") == 0) { 872 if (i + 1 < option_idx) 873 tsize = strtol(tftp_options[i + 1], NULL, 10); 874 if (tsize != 0) 875 h->tftp_tsize = tsize; 876 } else { 877 /* 878 * Do not allow any options we did not expect to be 879 * ACKed. 880 */ 881 printf("unexpected tftp option '%s'\n", 882 tftp_options[i]); 883 return (-1); 884 } 885 } 886 887 if (!blksize_is_set) { 888 /* 889 * If TFTP blksize was not set, try defaulting 890 * to the legacy TFTP blksize of SEGSIZE(512) 891 */ 892 h->tftp_blksize = SEGSIZE; 893 } else if (h->tftp_blksize > orig_blksize) { 894 /* 895 * Server should not be proposing block sizes that 896 * exceed what we said we can handle. 897 */ 898 printf("unexpected blksize %u\n", h->tftp_blksize); 899 return (-1); 900 } 901 902 DEBUG_PRINTF(2, ("tftp_blksize: %u\n", h->tftp_blksize)); 903 DEBUG_PRINTF(2, ("tftp_tsize: %lu\n", h->tftp_tsize)); 904 return (0); 905 } 906