1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1983, 1993
5 * The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 /*
33 * Trivial file transfer protocol server.
34 *
35 * This version includes many modifications by Jim Guyton
36 * <guyton@rand-unix>.
37 */
38
39 #include <sys/param.h>
40 #include <sys/ioctl.h>
41 #include <sys/socket.h>
42 #include <sys/stat.h>
43 #include <sys/time.h>
44
45 #include <netinet/in.h>
46 #include <arpa/tftp.h>
47
48 #include <ctype.h>
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <netdb.h>
52 #include <pwd.h>
53 #include <stdint.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <syslog.h>
58 #include <time.h>
59 #include <unistd.h>
60
61 #include "tftp-file.h"
62 #include "tftp-io.h"
63 #include "tftp-utils.h"
64 #include "tftp-transfer.h"
65 #include "tftp-options.h"
66
67 #ifdef LIBWRAP
68 #include <tcpd.h>
69 #endif
70
71 static void tftp_wrq(int peer, char *, size_t);
72 static void tftp_rrq(int peer, char *, size_t);
73
74 /*
75 * Null-terminated directory prefix list for absolute pathname requests and
76 * search list for relative pathname requests.
77 *
78 * MAXDIRS should be at least as large as the number of arguments that
79 * inetd allows (currently 20).
80 */
81 #define MAXDIRS 20
82 static struct dirlist {
83 const char *name;
84 size_t len;
85 } dirs[MAXDIRS+1];
86 static int suppress_naks;
87 static int logging;
88 static int ipchroot;
89 static int check_woth = 1;
90 static int create_new = 0;
91 static const char *newfile_format = "%Y%m%d";
92 static int increase_name = 0;
93 static mode_t mask = S_IWGRP | S_IWOTH;
94
95 struct formats;
96 static void tftp_recvfile(int peer, const char *mode);
97 static void tftp_xmitfile(int peer, const char *mode);
98 static int validate_access(int peer, char **, int);
99 static char peername[NI_MAXHOST];
100
101 static FILE *file;
102
103 static struct formats {
104 const char *f_mode;
105 int f_convert;
106 } formats[] = {
107 { "netascii", 1 },
108 { "octet", 0 },
109 { NULL, 0 }
110 };
111
112 int
main(int argc,char * argv[])113 main(int argc, char *argv[])
114 {
115 struct tftphdr *tp;
116 int peer;
117 socklen_t peerlen, len;
118 ssize_t n;
119 int ch;
120 char *chroot_dir = NULL;
121 struct passwd *nobody;
122 const char *chuser = "nobody";
123 char recvbuffer[MAXPKTSIZE];
124 int allow_ro = 1, allow_wo = 1, on = 1;
125 pid_t pid;
126
127 tzset(); /* syslog in localtime */
128 acting_as_client = 0;
129
130 tftp_openlog("tftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
131 while ((ch = getopt(argc, argv, "cCd::F:lnoOp:s:Su:U:wW")) != -1) {
132 switch (ch) {
133 case 'c':
134 ipchroot = 1;
135 break;
136 case 'C':
137 ipchroot = 2;
138 break;
139 case 'd':
140 if (optarg == NULL)
141 debug++;
142 else if (atoi(optarg) != 0)
143 debug += atoi(optarg);
144 else
145 debug |= debug_finds(optarg);
146 break;
147 case 'F':
148 newfile_format = optarg;
149 break;
150 case 'l':
151 logging = 1;
152 break;
153 case 'n':
154 suppress_naks = 1;
155 break;
156 case 'o':
157 options_rfc_enabled = 0;
158 break;
159 case 'O':
160 options_extra_enabled = 0;
161 break;
162 case 'p':
163 packetdroppercentage = (unsigned int)atoi(optarg);
164 tftp_log(LOG_INFO,
165 "Randomly dropping %d out of 100 packets",
166 packetdroppercentage);
167 break;
168 case 's':
169 chroot_dir = optarg;
170 break;
171 case 'S':
172 check_woth = -1;
173 break;
174 case 'u':
175 chuser = optarg;
176 break;
177 case 'U':
178 mask = strtol(optarg, NULL, 0);
179 break;
180 case 'w':
181 create_new = 1;
182 break;
183 case 'W':
184 create_new = 1;
185 increase_name = 1;
186 break;
187 default:
188 tftp_log(LOG_WARNING,
189 "ignoring unknown option -%c", ch);
190 }
191 }
192 if (optind < argc) {
193 struct dirlist *dirp;
194
195 /* Get list of directory prefixes. Skip relative pathnames. */
196 for (dirp = dirs; optind < argc && dirp < &dirs[MAXDIRS];
197 optind++) {
198 if (argv[optind][0] == '/') {
199 dirp->name = argv[optind];
200 dirp->len = strlen(dirp->name);
201 dirp++;
202 }
203 }
204 }
205 else if (chroot_dir) {
206 dirs->name = "/";
207 dirs->len = 1;
208 }
209 if (ipchroot > 0 && chroot_dir == NULL) {
210 tftp_log(LOG_ERR, "-c requires -s");
211 exit(1);
212 }
213
214 umask(mask);
215
216 if (ioctl(0, FIONBIO, &on) < 0) {
217 tftp_log(LOG_ERR, "ioctl(FIONBIO): %s", strerror(errno));
218 exit(1);
219 }
220
221 /* Find out who we are talking to and what we are going to do */
222 peerlen = sizeof(peer_sock);
223 n = recvfrom(0, recvbuffer, MAXPKTSIZE, 0,
224 (struct sockaddr *)&peer_sock, &peerlen);
225 if (n < 0) {
226 tftp_log(LOG_ERR, "recvfrom: %s", strerror(errno));
227 exit(1);
228 }
229 getnameinfo((struct sockaddr *)&peer_sock, peer_sock.ss_len,
230 peername, sizeof(peername), NULL, 0, NI_NUMERICHOST);
231 if ((size_t)n < 4 /* tftphdr */) {
232 tftp_log(LOG_ERR, "Rejecting %zd-byte request from %s",
233 n, peername);
234 exit(1);
235 }
236
237 /*
238 * Now that we have read the message out of the UDP
239 * socket, we fork and exit. Thus, inetd will go back
240 * to listening to the tftp port, and the next request
241 * to come in will start up a new instance of tftpd.
242 *
243 * We do this so that inetd can run tftpd in "wait" mode.
244 * The problem with tftpd running in "nowait" mode is that
245 * inetd may get one or more successful "selects" on the
246 * tftp port before we do our receive, so more than one
247 * instance of tftpd may be started up. Worse, if tftpd
248 * break before doing the above "recvfrom", inetd would
249 * spawn endless instances, clogging the system.
250 */
251 pid = fork();
252 if (pid < 0) {
253 tftp_log(LOG_ERR, "fork: %s", strerror(errno));
254 exit(1);
255 } else if (pid != 0) {
256 exit(0);
257 }
258 /* child */
259
260 #ifdef LIBWRAP
261 /*
262 * See if the client is allowed to talk to me.
263 * (This needs to be done before the chroot())
264 */
265 {
266 struct request_info req;
267
268 request_init(&req, RQ_CLIENT_ADDR, peername, 0);
269 request_set(&req, RQ_DAEMON, "tftpd", 0);
270
271 if (hosts_access(&req) == 0) {
272 if (debug & DEBUG_ACCESS)
273 tftp_log(LOG_WARNING,
274 "Access denied by 'tftpd' entry "
275 "in /etc/hosts.allow");
276
277 /*
278 * Full access might be disabled, but maybe the
279 * client is allowed to do read-only access.
280 */
281 request_set(&req, RQ_DAEMON, "tftpd-ro", 0);
282 allow_ro = hosts_access(&req);
283
284 request_set(&req, RQ_DAEMON, "tftpd-wo", 0);
285 allow_wo = hosts_access(&req);
286
287 if (allow_ro == 0 && allow_wo == 0) {
288 tftp_log(LOG_WARNING,
289 "Unauthorized access from %s", peername);
290 exit(1);
291 }
292
293 if (debug & DEBUG_ACCESS) {
294 if (allow_ro)
295 tftp_log(LOG_WARNING,
296 "But allowed readonly access "
297 "via 'tftpd-ro' entry");
298 if (allow_wo)
299 tftp_log(LOG_WARNING,
300 "But allowed writeonly access "
301 "via 'tftpd-wo' entry");
302 }
303 } else
304 if (debug & DEBUG_ACCESS)
305 tftp_log(LOG_WARNING,
306 "Full access allowed"
307 "in /etc/hosts.allow");
308 }
309 #endif
310
311 /*
312 * Since we exit here, we should do that only after the above
313 * recvfrom to keep inetd from constantly forking should there
314 * be a problem. See the above comment about system clogging.
315 */
316 if (chroot_dir) {
317 if (ipchroot > 0) {
318 char *tempchroot;
319 struct stat sb;
320 int statret;
321 struct sockaddr_storage ss;
322 char hbuf[NI_MAXHOST];
323
324 statret = -1;
325 memcpy(&ss, &peer_sock, peer_sock.ss_len);
326 unmappedaddr((struct sockaddr_in6 *)&ss);
327 getnameinfo((struct sockaddr *)&ss, ss.ss_len,
328 hbuf, sizeof(hbuf), NULL, 0,
329 NI_NUMERICHOST);
330 asprintf(&tempchroot, "%s/%s", chroot_dir, hbuf);
331 if (ipchroot == 2)
332 statret = stat(tempchroot, &sb);
333 if (ipchroot == 1 ||
334 (statret == 0 && (sb.st_mode & S_IFDIR)))
335 chroot_dir = tempchroot;
336 }
337 /* Must get this before chroot because /etc might go away */
338 if ((nobody = getpwnam(chuser)) == NULL) {
339 tftp_log(LOG_ERR, "%s: no such user", chuser);
340 exit(1);
341 }
342 if (chroot(chroot_dir)) {
343 tftp_log(LOG_ERR, "chroot: %s: %s",
344 chroot_dir, strerror(errno));
345 exit(1);
346 }
347 if (chdir("/") != 0) {
348 tftp_log(LOG_ERR, "chdir: %s", strerror(errno));
349 exit(1);
350 }
351 if (setgroups(1, &nobody->pw_gid) != 0) {
352 tftp_log(LOG_ERR, "setgroups failed");
353 exit(1);
354 }
355 if (setuid(nobody->pw_uid) != 0) {
356 tftp_log(LOG_ERR, "setuid failed");
357 exit(1);
358 }
359 if (check_woth == -1)
360 check_woth = 0;
361 }
362 if (check_woth == -1)
363 check_woth = 1;
364
365 len = sizeof(me_sock);
366 if (getsockname(0, (struct sockaddr *)&me_sock, &len) == 0) {
367 switch (me_sock.ss_family) {
368 case AF_INET:
369 ((struct sockaddr_in *)&me_sock)->sin_port = 0;
370 break;
371 case AF_INET6:
372 ((struct sockaddr_in6 *)&me_sock)->sin6_port = 0;
373 break;
374 default:
375 /* unsupported */
376 break;
377 }
378 } else {
379 memset(&me_sock, 0, sizeof(me_sock));
380 me_sock.ss_family = peer_sock.ss_family;
381 me_sock.ss_len = peer_sock.ss_len;
382 }
383 close(STDIN_FILENO);
384 close(STDOUT_FILENO);
385 close(STDERR_FILENO);
386 peer = socket(peer_sock.ss_family, SOCK_DGRAM, 0);
387 if (peer < 0) {
388 tftp_log(LOG_ERR, "socket: %s", strerror(errno));
389 exit(1);
390 }
391 if (bind(peer, (struct sockaddr *)&me_sock, me_sock.ss_len) < 0) {
392 tftp_log(LOG_ERR, "bind: %s", strerror(errno));
393 exit(1);
394 }
395
396 tp = (struct tftphdr *)recvbuffer;
397 tp->th_opcode = ntohs(tp->th_opcode);
398 if (tp->th_opcode == RRQ) {
399 if (allow_ro)
400 tftp_rrq(peer, tp->th_stuff, (size_t)n - 1);
401 else {
402 tftp_log(LOG_WARNING,
403 "%s read access denied", peername);
404 exit(1);
405 }
406 } else if (tp->th_opcode == WRQ) {
407 if (allow_wo)
408 tftp_wrq(peer, tp->th_stuff, (size_t)n - 1);
409 else {
410 tftp_log(LOG_WARNING,
411 "%s write access denied", peername);
412 exit(1);
413 }
414 } else
415 send_error(peer, EBADOP);
416 exit(1);
417 }
418
419 static void
reduce_path(char * fn)420 reduce_path(char *fn)
421 {
422 char *slash, *ptr;
423
424 /* Reduce all "/+./" to "/" (just in case we've got "/./../" later */
425 while ((slash = strstr(fn, "/./")) != NULL) {
426 for (ptr = slash; ptr > fn && ptr[-1] == '/'; ptr--)
427 ;
428 slash += 2;
429 while (*slash)
430 *++ptr = *++slash;
431 }
432
433 /* Now reduce all "/something/+../" to "/" */
434 while ((slash = strstr(fn, "/../")) != NULL) {
435 if (slash == fn)
436 break;
437 for (ptr = slash; ptr > fn && ptr[-1] == '/'; ptr--)
438 ;
439 for (ptr--; ptr >= fn; ptr--)
440 if (*ptr == '/')
441 break;
442 if (ptr < fn)
443 break;
444 slash += 3;
445 while (*slash)
446 *++ptr = *++slash;
447 }
448 }
449
450 static char *
parse_header(int peer,char * recvbuffer,size_t size,char ** filename,char ** mode)451 parse_header(int peer, char *recvbuffer, size_t size,
452 char **filename, char **mode)
453 {
454 struct formats *pf;
455 char *cp;
456 size_t i;
457
458 *mode = NULL;
459 cp = recvbuffer;
460
461 i = get_field(peer, recvbuffer, size);
462 if (i >= PATH_MAX) {
463 tftp_log(LOG_ERR, "Bad option - filename too long");
464 send_error(peer, EBADOP);
465 exit(1);
466 }
467 *filename = recvbuffer;
468 tftp_log(LOG_INFO, "Filename: '%s'", *filename);
469 cp += i;
470
471 i = get_field(peer, cp, size);
472 *mode = cp;
473
474 /* Find the file transfer mode */
475 for (; *cp; cp++)
476 if (isupper((unsigned char)*cp))
477 *cp = tolower((unsigned char)*cp);
478 for (pf = formats; pf->f_mode; pf++)
479 if (strcmp(pf->f_mode, *mode) == 0)
480 break;
481 if (pf->f_mode == NULL) {
482 tftp_log(LOG_ERR,
483 "Bad option - Unknown transfer mode (%s)", *mode);
484 send_error(peer, EBADOP);
485 exit(1);
486 }
487 tftp_log(LOG_INFO, "Mode: '%s'", *mode);
488
489 return (cp + 1);
490 }
491
492 /*
493 * WRQ - receive a file from the client
494 */
495 void
tftp_wrq(int peer,char * recvbuffer,size_t size)496 tftp_wrq(int peer, char *recvbuffer, size_t size)
497 {
498 char *cp;
499 int has_options = 0, ecode;
500 char *filename, *mode;
501 char fnbuf[PATH_MAX];
502
503 cp = parse_header(peer, recvbuffer, size, &filename, &mode);
504 size -= (cp - recvbuffer) + 1;
505
506 strlcpy(fnbuf, filename, sizeof(fnbuf));
507 reduce_path(fnbuf);
508 filename = fnbuf;
509
510 if (size > 0) {
511 if (options_rfc_enabled)
512 has_options = !parse_options(peer, cp, size);
513 else
514 tftp_log(LOG_INFO, "Options found but not enabled");
515 }
516
517 ecode = validate_access(peer, &filename, WRQ);
518 if (ecode == 0) {
519 if (has_options)
520 send_oack(peer);
521 else
522 send_ack(peer, 0);
523 }
524 if (logging) {
525 tftp_log(LOG_INFO, "%s: write request for %s: %s", peername,
526 filename, errtomsg(ecode));
527 }
528
529 if (ecode) {
530 send_error(peer, ecode);
531 exit(1);
532 }
533 tftp_recvfile(peer, mode);
534 exit(0);
535 }
536
537 /*
538 * RRQ - send a file to the client
539 */
540 void
tftp_rrq(int peer,char * recvbuffer,size_t size)541 tftp_rrq(int peer, char *recvbuffer, size_t size)
542 {
543 char *cp;
544 int has_options = 0, ecode;
545 char *filename, *mode;
546 char fnbuf[PATH_MAX];
547
548 cp = parse_header(peer, recvbuffer, size, &filename, &mode);
549 size -= (cp - recvbuffer) + 1;
550
551 strlcpy(fnbuf, filename, sizeof(fnbuf));
552 reduce_path(fnbuf);
553 filename = fnbuf;
554
555 if (size > 0) {
556 if (options_rfc_enabled)
557 has_options = !parse_options(peer, cp, size);
558 else
559 tftp_log(LOG_INFO, "Options found but not enabled");
560 }
561
562 ecode = validate_access(peer, &filename, RRQ);
563 if (ecode == 0) {
564 if (has_options) {
565 int n;
566 char lrecvbuffer[MAXPKTSIZE];
567 struct tftphdr *rp = (struct tftphdr *)lrecvbuffer;
568
569 send_oack(peer);
570 n = receive_packet(peer, lrecvbuffer, MAXPKTSIZE,
571 NULL, timeoutpacket);
572 if (n < 0) {
573 if (debug & DEBUG_SIMPLE)
574 tftp_log(LOG_DEBUG, "Aborting: %s",
575 rp_strerror(n));
576 return;
577 }
578 if (rp->th_opcode != ACK) {
579 if (debug & DEBUG_SIMPLE)
580 tftp_log(LOG_DEBUG,
581 "Expected ACK, got %s on OACK",
582 packettype(rp->th_opcode));
583 return;
584 }
585 }
586 }
587
588 if (logging)
589 tftp_log(LOG_INFO, "%s: read request for %s: %s", peername,
590 filename, errtomsg(ecode));
591
592 if (ecode) {
593 /*
594 * Avoid storms of naks to a RRQ broadcast for a relative
595 * bootfile pathname from a diskless Sun.
596 */
597 if (suppress_naks && *filename != '/' && ecode == ENOTFOUND)
598 exit(0);
599 send_error(peer, ecode);
600 exit(1);
601 }
602 tftp_xmitfile(peer, mode);
603 }
604
605 /*
606 * Find the next value for YYYYMMDD.nn when the file to be written should
607 * be unique. Due to the limitations of nn, we will fail if nn reaches 100.
608 * Besides, that is four updates per hour on a file, which is kind of
609 * execessive anyway.
610 */
611 static int
find_next_name(char * filename,int * fd)612 find_next_name(char *filename, int *fd)
613 {
614 /*
615 * GCC "knows" that we might write all of yyyymmdd plus the static
616 * elemenents in the format into into newname and thus complains
617 * unless we reduce the size. This array is still too big, but since
618 * the format is user supplied, it's not clear what a better limit
619 * value would be and this is sufficent to silence the warnings.
620 */
621 static const int suffix_len = strlen("..00");
622 char yyyymmdd[MAXPATHLEN - suffix_len];
623 char newname[MAXPATHLEN];
624 int i, ret;
625 time_t tval;
626 size_t len, namelen;
627 struct tm lt;
628
629 /* Create the YYYYMMDD part of the filename */
630 time(&tval);
631 lt = *localtime(&tval);
632 len = strftime(yyyymmdd, sizeof(yyyymmdd), newfile_format, <);
633 if (len == 0) {
634 syslog(LOG_WARNING,
635 "Filename suffix too long (%zu characters maximum)",
636 sizeof(yyyymmdd) - 1);
637 return (EACCESS);
638 }
639
640 /* Make sure the new filename is not too long */
641 namelen = strlen(filename);
642 if (namelen >= sizeof(newname) - len - suffix_len) {
643 syslog(LOG_WARNING,
644 "Filename too long (%zu characters, %zu maximum)",
645 namelen,
646 sizeof(newname) - len - suffix_len - 1);
647 return (EACCESS);
648 }
649
650 /* Find the first file which doesn't exist */
651 for (i = 0; i < 100; i++) {
652 ret = snprintf(newname, sizeof(newname), "%s.%s.%02d",
653 filename, yyyymmdd, i);
654 /*
655 * Size checked above so this can't happen, we'd use a
656 * (void) cast, but gcc intentionally ignores that if
657 * snprintf has __attribute__((warn_unused_result)).
658 */
659 if (ret < 0 || (size_t)ret >= sizeof(newname))
660 __unreachable();
661 *fd = open(newname, O_WRONLY | O_CREAT | O_EXCL, 0666);
662 if (*fd > 0)
663 return 0;
664 }
665
666 return (EEXIST);
667 }
668
669 /*
670 * Validate file access. Since we
671 * have no uid or gid, for now require
672 * file to exist and be publicly
673 * readable/writable.
674 * If we were invoked with arguments
675 * from inetd then the file must also be
676 * in one of the given directory prefixes.
677 * Note also, full path name must be
678 * given as we have no login directory.
679 */
680 int
validate_access(int peer,char ** filep,int mode)681 validate_access(int peer, char **filep, int mode)
682 {
683 struct stat stbuf;
684 int fd;
685 int error;
686 struct dirlist *dirp;
687 static char pathname[MAXPATHLEN];
688 char *filename = *filep;
689
690 /*
691 * Prevent tricksters from getting around the directory restrictions
692 */
693 if (strstr(filename, "/../"))
694 return (EACCESS);
695
696 if (*filename == '/') {
697 /*
698 * Allow the request if it's in one of the approved locations.
699 * Special case: check the null prefix ("/") by looking
700 * for length = 1 and relying on the arg. processing that
701 * it's a /.
702 */
703 for (dirp = dirs; dirp->name != NULL; dirp++) {
704 if (dirp->len == 1)
705 break;
706 if (strncmp(filename, dirp->name, dirp->len) == 0 &&
707 filename[dirp->len] == '/')
708 break;
709 }
710 /* If directory list is empty, allow access to any file */
711 if (dirp->name == NULL && dirp != dirs)
712 return (EACCESS);
713 if (stat(filename, &stbuf) < 0)
714 return (errno == ENOENT ? ENOTFOUND : EACCESS);
715 if ((stbuf.st_mode & S_IFMT) != S_IFREG)
716 return (ENOTFOUND);
717 if (mode == RRQ) {
718 if ((stbuf.st_mode & S_IROTH) == 0)
719 return (EACCESS);
720 } else {
721 if (check_woth && ((stbuf.st_mode & S_IWOTH) == 0))
722 return (EACCESS);
723 }
724 } else {
725 int err;
726
727 /*
728 * Relative file name: search the approved locations for it.
729 * Don't allow write requests that avoid directory
730 * restrictions.
731 */
732
733 if (!strncmp(filename, "../", 3))
734 return (EACCESS);
735
736 /*
737 * If the file exists in one of the directories and isn't
738 * readable, continue looking. However, change the error code
739 * to give an indication that the file exists.
740 */
741 err = ENOTFOUND;
742 for (dirp = dirs; dirp->name != NULL; dirp++) {
743 snprintf(pathname, sizeof(pathname), "%s/%s",
744 dirp->name, filename);
745 if (stat(pathname, &stbuf) == 0 &&
746 (stbuf.st_mode & S_IFMT) == S_IFREG) {
747 if (mode == RRQ) {
748 if ((stbuf.st_mode & S_IROTH) != 0)
749 break;
750 } else {
751 if (!check_woth || ((stbuf.st_mode & S_IWOTH) != 0))
752 break;
753 }
754 err = EACCESS;
755 }
756 }
757 if (dirp->name != NULL)
758 *filep = filename = pathname;
759 else if (mode == RRQ)
760 return (err);
761 else if (err != ENOTFOUND || !create_new)
762 return (err);
763 }
764
765 /*
766 * This option is handled here because it (might) require(s) the
767 * size of the file.
768 */
769 option_tsize(peer, NULL, mode, &stbuf);
770
771 if (mode == RRQ)
772 fd = open(filename, O_RDONLY);
773 else {
774 if (create_new) {
775 if (increase_name) {
776 error = find_next_name(filename, &fd);
777 if (error > 0)
778 return (error + 100);
779 } else
780 fd = open(filename,
781 O_WRONLY | O_TRUNC | O_CREAT,
782 S_IRUSR | S_IWUSR | S_IRGRP |
783 S_IWGRP | S_IROTH | S_IWOTH );
784 } else
785 fd = open(filename, O_WRONLY | O_TRUNC);
786 }
787 if (fd < 0)
788 return (errno + 100);
789 file = fdopen(fd, (mode == RRQ)? "r":"w");
790 if (file == NULL) {
791 close(fd);
792 return (errno + 100);
793 }
794 return (0);
795 }
796
797 static void
tftp_xmitfile(int peer,const char * mode)798 tftp_xmitfile(int peer, const char *mode)
799 {
800 uint16_t block;
801 time_t now;
802 struct tftp_stats ts;
803
804 memset(&ts, 0, sizeof(ts));
805 now = time(NULL);
806 if (debug & DEBUG_SIMPLE)
807 tftp_log(LOG_DEBUG, "Transmitting file");
808
809 read_init(0, file, mode);
810 block = 1;
811 tftp_send(peer, &block, &ts);
812 read_close();
813 if (debug & DEBUG_SIMPLE)
814 tftp_log(LOG_INFO, "Sent %jd bytes in %jd seconds",
815 (intmax_t)ts.amount, (intmax_t)time(NULL) - now);
816 }
817
818 static void
tftp_recvfile(int peer,const char * mode)819 tftp_recvfile(int peer, const char *mode)
820 {
821 uint16_t block;
822 struct timeval now1, now2;
823 struct tftp_stats ts;
824
825 gettimeofday(&now1, NULL);
826 if (debug & DEBUG_SIMPLE)
827 tftp_log(LOG_DEBUG, "Receiving file");
828
829 write_init(0, file, mode);
830
831 block = 0;
832 tftp_receive(peer, &block, &ts, NULL, 0);
833
834 gettimeofday(&now2, NULL);
835
836 if (debug & DEBUG_SIMPLE) {
837 double f;
838 if (now1.tv_usec > now2.tv_usec) {
839 now2.tv_usec += 1000000;
840 now2.tv_sec--;
841 }
842
843 f = now2.tv_sec - now1.tv_sec +
844 (now2.tv_usec - now1.tv_usec) / 100000.0;
845 tftp_log(LOG_INFO,
846 "Download of %jd bytes in %d blocks completed after %0.1f seconds\n",
847 (intmax_t)ts.amount, block, f);
848 }
849
850 return;
851 }
852