tftpd.c revision 337249 
1/*
2 * Copyright (c) 1983, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#ifndef lint
31static const char copyright[] =
32"@(#) Copyright (c) 1983, 1993\n\
33	The Regents of the University of California.  All rights reserved.\n";
34#endif /* not lint */
35
36#ifndef lint
37#if 0
38static char sccsid[] = "@(#)tftpd.c	8.1 (Berkeley) 6/4/93";
39#endif
40#endif /* not lint */
41#include <sys/cdefs.h>
42__FBSDID("$FreeBSD: stable/10/libexec/tftpd/tftpd.c 337249 2018-08-03 14:19:09Z asomers $");
43
44/*
45 * Trivial file transfer protocol server.
46 *
47 * This version includes many modifications by Jim Guyton
48 * <guyton@rand-unix>.
49 */
50
51#include <sys/param.h>
52#include <sys/ioctl.h>
53#include <sys/stat.h>
54#include <sys/socket.h>
55
56#include <netinet/in.h>
57#include <arpa/tftp.h>
58
59#include <ctype.h>
60#include <errno.h>
61#include <fcntl.h>
62#include <netdb.h>
63#include <pwd.h>
64#include <stdint.h>
65#include <stdio.h>
66#include <stdlib.h>
67#include <string.h>
68#include <syslog.h>
69#include <unistd.h>
70
71#include "tftp-file.h"
72#include "tftp-io.h"
73#include "tftp-utils.h"
74#include "tftp-transfer.h"
75#include "tftp-options.h"
76
77#ifdef	LIBWRAP
78#include <tcpd.h>
79#endif
80
81static void	tftp_wrq(int peer, char *, ssize_t);
82static void	tftp_rrq(int peer, char *, ssize_t);
83
84/*
85 * Null-terminated directory prefix list for absolute pathname requests and
86 * search list for relative pathname requests.
87 *
88 * MAXDIRS should be at least as large as the number of arguments that
89 * inetd allows (currently 20).
90 */
91#define MAXDIRS	20
92static struct dirlist {
93	const char	*name;
94	int	len;
95} dirs[MAXDIRS+1];
96static int	suppress_naks;
97static int	logging;
98static int	ipchroot;
99static int	create_new = 0;
100static const char *newfile_format = "%Y%m%d";
101static int	increase_name = 0;
102static mode_t	mask = S_IWGRP | S_IWOTH;
103
104struct formats;
105static void	tftp_recvfile(int peer, const char *mode);
106static void	tftp_xmitfile(int peer, const char *mode);
107static int	validate_access(int peer, char **, int);
108static char	peername[NI_MAXHOST];
109
110static FILE *file;
111
112static struct formats {
113	const char	*f_mode;
114	int	f_convert;
115} formats[] = {
116	{ "netascii",	1 },
117	{ "octet",	0 },
118	{ NULL,		0 }
119};
120
121int
122main(int argc, char *argv[])
123{
124	struct tftphdr *tp;
125	int		peer;
126	socklen_t	peerlen, len;
127	ssize_t		n;
128	int		ch;
129	char		*chroot_dir = NULL;
130	struct passwd	*nobody;
131	const char	*chuser = "nobody";
132	char		recvbuffer[MAXPKTSIZE];
133	int		allow_ro = 1, allow_wo = 1;
134
135	tzset();			/* syslog in localtime */
136	acting_as_client = 0;
137
138	tftp_openlog("tftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
139	while ((ch = getopt(argc, argv, "cCd:F:lnoOp:s:u:U:wW")) != -1) {
140		switch (ch) {
141		case 'c':
142			ipchroot = 1;
143			break;
144		case 'C':
145			ipchroot = 2;
146			break;
147		case 'd':
148			if (atoi(optarg) != 0)
149				debug += atoi(optarg);
150			else
151				debug |= debug_finds(optarg);
152			break;
153		case 'F':
154			newfile_format = optarg;
155			break;
156		case 'l':
157			logging = 1;
158			break;
159		case 'n':
160			suppress_naks = 1;
161			break;
162		case 'o':
163			options_rfc_enabled = 0;
164			break;
165		case 'O':
166			options_extra_enabled = 0;
167			break;
168		case 'p':
169			packetdroppercentage = atoi(optarg);
170			tftp_log(LOG_INFO,
171			    "Randomly dropping %d out of 100 packets",
172			    packetdroppercentage);
173			break;
174		case 's':
175			chroot_dir = optarg;
176			break;
177		case 'u':
178			chuser = optarg;
179			break;
180		case 'U':
181			mask = strtol(optarg, NULL, 0);
182			break;
183		case 'w':
184			create_new = 1;
185			break;
186		case 'W':
187			create_new = 1;
188			increase_name = 1;
189			break;
190		default:
191			tftp_log(LOG_WARNING,
192				"ignoring unknown option -%c", ch);
193		}
194	}
195	if (optind < argc) {
196		struct dirlist *dirp;
197
198		/* Get list of directory prefixes. Skip relative pathnames. */
199		for (dirp = dirs; optind < argc && dirp < &dirs[MAXDIRS];
200		     optind++) {
201			if (argv[optind][0] == '/') {
202				dirp->name = argv[optind];
203				dirp->len  = strlen(dirp->name);
204				dirp++;
205			}
206		}
207	}
208	else if (chroot_dir) {
209		dirs->name = "/";
210		dirs->len = 1;
211	}
212	if (ipchroot > 0 && chroot_dir == NULL) {
213		tftp_log(LOG_ERR, "-c requires -s");
214		exit(1);
215	}
216
217	umask(mask);
218
219	{
220		int on = 1;
221		if (ioctl(0, FIONBIO, &on) < 0) {
222			tftp_log(LOG_ERR, "ioctl(FIONBIO): %s", strerror(errno));
223			exit(1);
224		}
225	}
226
227	/* Find out who we are talking to and what we are going to do */
228	peerlen = sizeof(peer_sock);
229	n = recvfrom(0, recvbuffer, MAXPKTSIZE, 0,
230	    (struct sockaddr *)&peer_sock, &peerlen);
231	if (n < 0) {
232		tftp_log(LOG_ERR, "recvfrom: %s", strerror(errno));
233		exit(1);
234	}
235	getnameinfo((struct sockaddr *)&peer_sock, peer_sock.ss_len,
236	    peername, sizeof(peername), NULL, 0, NI_NUMERICHOST);
237
238	/*
239	 * Now that we have read the message out of the UDP
240	 * socket, we fork and exit.  Thus, inetd will go back
241	 * to listening to the tftp port, and the next request
242	 * to come in will start up a new instance of tftpd.
243	 *
244	 * We do this so that inetd can run tftpd in "wait" mode.
245	 * The problem with tftpd running in "nowait" mode is that
246	 * inetd may get one or more successful "selects" on the
247	 * tftp port before we do our receive, so more than one
248	 * instance of tftpd may be started up.  Worse, if tftpd
249	 * break before doing the above "recvfrom", inetd would
250	 * spawn endless instances, clogging the system.
251	 */
252	{
253		int i, pid;
254
255		for (i = 1; i < 20; i++) {
256		    pid = fork();
257		    if (pid < 0) {
258				sleep(i);
259				/*
260				 * flush out to most recently sent request.
261				 *
262				 * This may drop some request, but those
263				 * will be resent by the clients when
264				 * they timeout.  The positive effect of
265				 * this flush is to (try to) prevent more
266				 * than one tftpd being started up to service
267				 * a single request from a single client.
268				 */
269				peerlen = sizeof peer_sock;
270				i = recvfrom(0, recvbuffer, MAXPKTSIZE, 0,
271				    (struct sockaddr *)&peer_sock, &peerlen);
272				if (i > 0) {
273					n = i;
274				}
275		    } else {
276				break;
277		    }
278		}
279		if (pid < 0) {
280			tftp_log(LOG_ERR, "fork: %s", strerror(errno));
281			exit(1);
282		} else if (pid != 0) {
283			exit(0);
284		}
285	}
286
287#ifdef	LIBWRAP
288	/*
289	 * See if the client is allowed to talk to me.
290	 * (This needs to be done before the chroot())
291	 */
292	{
293		struct request_info req;
294
295		request_init(&req, RQ_CLIENT_ADDR, peername, 0);
296		request_set(&req, RQ_DAEMON, "tftpd", 0);
297
298		if (hosts_access(&req) == 0) {
299			if (debug&DEBUG_ACCESS)
300				tftp_log(LOG_WARNING,
301				    "Access denied by 'tftpd' entry "
302				    "in /etc/hosts.allow");
303
304			/*
305			 * Full access might be disabled, but maybe the
306			 * client is allowed to do read-only access.
307			 */
308			request_set(&req, RQ_DAEMON, "tftpd-ro", 0);
309			allow_ro = hosts_access(&req);
310
311			request_set(&req, RQ_DAEMON, "tftpd-wo", 0);
312			allow_wo = hosts_access(&req);
313
314			if (allow_ro == 0 && allow_wo == 0) {
315				tftp_log(LOG_WARNING,
316				    "Unauthorized access from %s", peername);
317				exit(1);
318			}
319
320			if (debug&DEBUG_ACCESS) {
321				if (allow_ro)
322					tftp_log(LOG_WARNING,
323					    "But allowed readonly access "
324					    "via 'tftpd-ro' entry");
325				if (allow_wo)
326					tftp_log(LOG_WARNING,
327					    "But allowed writeonly access "
328					    "via 'tftpd-wo' entry");
329			}
330		} else
331			if (debug&DEBUG_ACCESS)
332				tftp_log(LOG_WARNING,
333				    "Full access allowed"
334				    "in /etc/hosts.allow");
335	}
336#endif
337
338	/*
339	 * Since we exit here, we should do that only after the above
340	 * recvfrom to keep inetd from constantly forking should there
341	 * be a problem.  See the above comment about system clogging.
342	 */
343	if (chroot_dir) {
344		if (ipchroot > 0) {
345			char *tempchroot;
346			struct stat sb;
347			int statret;
348			struct sockaddr_storage ss;
349			char hbuf[NI_MAXHOST];
350
351			statret = -1;
352			memcpy(&ss, &peer_sock, peer_sock.ss_len);
353			unmappedaddr((struct sockaddr_in6 *)&ss);
354			getnameinfo((struct sockaddr *)&ss, ss.ss_len,
355				    hbuf, sizeof(hbuf), NULL, 0,
356				    NI_NUMERICHOST);
357			asprintf(&tempchroot, "%s/%s", chroot_dir, hbuf);
358			if (ipchroot == 2)
359				statret = stat(tempchroot, &sb);
360			if (ipchroot == 1 ||
361			    (statret == 0 && (sb.st_mode & S_IFDIR)))
362				chroot_dir = tempchroot;
363		}
364		/* Must get this before chroot because /etc might go away */
365		if ((nobody = getpwnam(chuser)) == NULL) {
366			tftp_log(LOG_ERR, "%s: no such user", chuser);
367			exit(1);
368		}
369		if (chroot(chroot_dir)) {
370			tftp_log(LOG_ERR, "chroot: %s: %s",
371			    chroot_dir, strerror(errno));
372			exit(1);
373		}
374		chdir("/");
375		setgroups(1, &nobody->pw_gid);
376		if (setuid(nobody->pw_uid) != 0) {
377			tftp_log(LOG_ERR, "setuid failed");
378			exit(1);
379		}
380	}
381
382	len = sizeof(me_sock);
383	if (getsockname(0, (struct sockaddr *)&me_sock, &len) == 0) {
384		switch (me_sock.ss_family) {
385		case AF_INET:
386			((struct sockaddr_in *)&me_sock)->sin_port = 0;
387			break;
388		case AF_INET6:
389			((struct sockaddr_in6 *)&me_sock)->sin6_port = 0;
390			break;
391		default:
392			/* unsupported */
393			break;
394		}
395	} else {
396		memset(&me_sock, 0, sizeof(me_sock));
397		me_sock.ss_family = peer_sock.ss_family;
398		me_sock.ss_len = peer_sock.ss_len;
399	}
400	close(0);
401	close(1);
402	peer = socket(peer_sock.ss_family, SOCK_DGRAM, 0);
403	if (peer < 0) {
404		tftp_log(LOG_ERR, "socket: %s", strerror(errno));
405		exit(1);
406	}
407	if (bind(peer, (struct sockaddr *)&me_sock, me_sock.ss_len) < 0) {
408		tftp_log(LOG_ERR, "bind: %s", strerror(errno));
409		exit(1);
410	}
411
412	tp = (struct tftphdr *)recvbuffer;
413	tp->th_opcode = ntohs(tp->th_opcode);
414	if (tp->th_opcode == RRQ) {
415		if (allow_ro)
416			tftp_rrq(peer, tp->th_stuff, n - 1);
417		else {
418			tftp_log(LOG_WARNING,
419			    "%s read access denied", peername);
420			exit(1);
421		}
422	}
423	if (tp->th_opcode == WRQ) {
424		if (allow_wo)
425			tftp_wrq(peer, tp->th_stuff, n - 1);
426		else {
427			tftp_log(LOG_WARNING,
428			    "%s write access denied", peername);
429			exit(1);
430		}
431	}
432	exit(1);
433}
434
435static void
436reduce_path(char *fn)
437{
438	char *slash, *ptr;
439
440	/* Reduce all "/+./" to "/" (just in case we've got "/./../" later */
441	while ((slash = strstr(fn, "/./")) != NULL) {
442		for (ptr = slash; ptr > fn && ptr[-1] == '/'; ptr--)
443			;
444		slash += 2;
445		while (*slash)
446			*++ptr = *++slash;
447	}
448
449	/* Now reduce all "/something/+../" to "/" */
450	while ((slash = strstr(fn, "/../")) != NULL) {
451		if (slash == fn)
452			break;
453		for (ptr = slash; ptr > fn && ptr[-1] == '/'; ptr--)
454			;
455		for (ptr--; ptr >= fn; ptr--)
456			if (*ptr == '/')
457				break;
458		if (ptr < fn)
459			break;
460		slash += 3;
461		while (*slash)
462			*++ptr = *++slash;
463	}
464}
465
466static char *
467parse_header(int peer, char *recvbuffer, ssize_t size,
468	char **filename, char **mode)
469{
470	char	*cp;
471	int	i;
472	struct formats *pf;
473
474	*mode = NULL;
475	cp = recvbuffer;
476
477	i = get_field(peer, recvbuffer, size);
478	if (i >= PATH_MAX) {
479		tftp_log(LOG_ERR, "Bad option - filename too long");
480		send_error(peer, EBADOP);
481		exit(1);
482	}
483	*filename = recvbuffer;
484	tftp_log(LOG_INFO, "Filename: '%s'", *filename);
485	cp += i;
486
487	i = get_field(peer, cp, size);
488	*mode = cp;
489	cp += i;
490
491	/* Find the file transfer mode */
492	for (cp = *mode; *cp; cp++)
493		if (isupper(*cp))
494			*cp = tolower(*cp);
495	for (pf = formats; pf->f_mode; pf++)
496		if (strcmp(pf->f_mode, *mode) == 0)
497			break;
498	if (pf->f_mode == NULL) {
499		tftp_log(LOG_ERR,
500		    "Bad option - Unknown transfer mode (%s)", *mode);
501		send_error(peer, EBADOP);
502		exit(1);
503	}
504	tftp_log(LOG_INFO, "Mode: '%s'", *mode);
505
506	return (cp + 1);
507}
508
509/*
510 * WRQ - receive a file from the client
511 */
512void
513tftp_wrq(int peer, char *recvbuffer, ssize_t size)
514{
515	char *cp;
516	int has_options = 0, ecode;
517	char *filename, *mode;
518	char fnbuf[PATH_MAX];
519
520	cp = parse_header(peer, recvbuffer, size, &filename, &mode);
521	size -= (cp - recvbuffer) + 1;
522
523	strcpy(fnbuf, filename);
524	reduce_path(fnbuf);
525	filename = fnbuf;
526
527	if (size > 0) {
528		if (options_rfc_enabled)
529			has_options = !parse_options(peer, cp, size);
530		else
531			tftp_log(LOG_INFO, "Options found but not enabled");
532	}
533
534	ecode = validate_access(peer, &filename, WRQ);
535	if (ecode == 0) {
536		if (has_options)
537			send_oack(peer);
538		else
539			send_ack(peer, 0);
540	}
541	if (logging) {
542		tftp_log(LOG_INFO, "%s: write request for %s: %s", peername,
543			    filename, errtomsg(ecode));
544	}
545
546	if (ecode) {
547		send_error(peer, ecode);
548		exit(1);
549	}
550	tftp_recvfile(peer, mode);
551	exit(0);
552}
553
554/*
555 * RRQ - send a file to the client
556 */
557void
558tftp_rrq(int peer, char *recvbuffer, ssize_t size)
559{
560	char *cp;
561	int has_options = 0, ecode;
562	char *filename, *mode;
563	char	fnbuf[PATH_MAX];
564
565	cp = parse_header(peer, recvbuffer, size, &filename, &mode);
566	size -= (cp - recvbuffer) + 1;
567
568	strcpy(fnbuf, filename);
569	reduce_path(fnbuf);
570	filename = fnbuf;
571
572	if (size > 0) {
573		if (options_rfc_enabled)
574			has_options = !parse_options(peer, cp, size);
575		else
576			tftp_log(LOG_INFO, "Options found but not enabled");
577	}
578
579	ecode = validate_access(peer, &filename, RRQ);
580	if (ecode == 0) {
581		if (has_options) {
582			int n;
583			char lrecvbuffer[MAXPKTSIZE];
584			struct tftphdr *rp = (struct tftphdr *)lrecvbuffer;
585
586			send_oack(peer);
587			n = receive_packet(peer, lrecvbuffer, MAXPKTSIZE,
588				NULL, timeoutpacket);
589			if (n < 0) {
590				if (debug&DEBUG_SIMPLE)
591					tftp_log(LOG_DEBUG, "Aborting: %s",
592					    rp_strerror(n));
593				return;
594			}
595			if (rp->th_opcode != ACK) {
596				if (debug&DEBUG_SIMPLE)
597					tftp_log(LOG_DEBUG,
598					    "Expected ACK, got %s on OACK",
599					    packettype(rp->th_opcode));
600				return;
601			}
602		}
603	}
604
605	if (logging)
606		tftp_log(LOG_INFO, "%s: read request for %s: %s", peername,
607			    filename, errtomsg(ecode));
608
609	if (ecode) {
610		/*
611		 * Avoid storms of naks to a RRQ broadcast for a relative
612		 * bootfile pathname from a diskless Sun.
613		 */
614		if (suppress_naks && *filename != '/' && ecode == ENOTFOUND)
615			exit(0);
616		send_error(peer, ecode);
617		exit(1);
618	}
619	tftp_xmitfile(peer, mode);
620}
621
622/*
623 * Find the next value for YYYYMMDD.nn when the file to be written should
624 * be unique. Due to the limitations of nn, we will fail if nn reaches 100.
625 * Besides, that is four updates per hour on a file, which is kind of
626 * execessive anyway.
627 */
628static int
629find_next_name(char *filename, int *fd)
630{
631	int i;
632	time_t tval;
633	size_t len;
634	struct tm lt;
635	char yyyymmdd[MAXPATHLEN];
636	char newname[MAXPATHLEN];
637
638	/* Create the YYYYMMDD part of the filename */
639	time(&tval);
640	lt = *localtime(&tval);
641	len = strftime(yyyymmdd, sizeof(yyyymmdd), newfile_format, &lt);
642	if (len == 0) {
643		syslog(LOG_WARNING,
644			"Filename suffix too long (%d characters maximum)",
645			MAXPATHLEN);
646		return (EACCESS);
647	}
648
649	/* Make sure the new filename is not too long */
650	if (strlen(filename) > MAXPATHLEN - len - 5) {
651		syslog(LOG_WARNING,
652			"Filename too long (%zd characters, %zd maximum)",
653			strlen(filename), MAXPATHLEN - len - 5);
654		return (EACCESS);
655	}
656
657	/* Find the first file which doesn't exist */
658	for (i = 0; i < 100; i++) {
659		sprintf(newname, "%s.%s.%02d", filename, yyyymmdd, i);
660		*fd = open(newname,
661		    O_WRONLY | O_CREAT | O_EXCL,
662		    S_IRUSR | S_IWUSR | S_IRGRP |
663		    S_IWGRP | S_IROTH | S_IWOTH);
664		if (*fd > 0)
665			return 0;
666	}
667
668	return (EEXIST);
669}
670
671/*
672 * Validate file access.  Since we
673 * have no uid or gid, for now require
674 * file to exist and be publicly
675 * readable/writable.
676 * If we were invoked with arguments
677 * from inetd then the file must also be
678 * in one of the given directory prefixes.
679 * Note also, full path name must be
680 * given as we have no login directory.
681 */
682int
683validate_access(int peer, char **filep, int mode)
684{
685	struct stat stbuf;
686	int	fd;
687	int	error;
688	struct dirlist *dirp;
689	static char pathname[MAXPATHLEN];
690	char *filename = *filep;
691
692	/*
693	 * Prevent tricksters from getting around the directory restrictions
694	 */
695	if (strstr(filename, "/../"))
696		return (EACCESS);
697
698	if (*filename == '/') {
699		/*
700		 * Allow the request if it's in one of the approved locations.
701		 * Special case: check the null prefix ("/") by looking
702		 * for length = 1 and relying on the arg. processing that
703		 * it's a /.
704		 */
705		for (dirp = dirs; dirp->name != NULL; dirp++) {
706			if (dirp->len == 1 ||
707			    (!strncmp(filename, dirp->name, dirp->len) &&
708			     filename[dirp->len] == '/'))
709				    break;
710		}
711		/* If directory list is empty, allow access to any file */
712		if (dirp->name == NULL && dirp != dirs)
713			return (EACCESS);
714		if (stat(filename, &stbuf) < 0)
715			return (errno == ENOENT ? ENOTFOUND : EACCESS);
716		if ((stbuf.st_mode & S_IFMT) != S_IFREG)
717			return (ENOTFOUND);
718		if (mode == RRQ) {
719			if ((stbuf.st_mode & S_IROTH) == 0)
720				return (EACCESS);
721		} else {
722			if ((stbuf.st_mode & S_IWOTH) == 0)
723				return (EACCESS);
724		}
725	} else {
726		int err;
727
728		/*
729		 * Relative file name: search the approved locations for it.
730		 * Don't allow write requests that avoid directory
731		 * restrictions.
732		 */
733
734		if (!strncmp(filename, "../", 3))
735			return (EACCESS);
736
737		/*
738		 * If the file exists in one of the directories and isn't
739		 * readable, continue looking. However, change the error code
740		 * to give an indication that the file exists.
741		 */
742		err = ENOTFOUND;
743		for (dirp = dirs; dirp->name != NULL; dirp++) {
744			snprintf(pathname, sizeof(pathname), "%s/%s",
745				dirp->name, filename);
746			if (stat(pathname, &stbuf) == 0 &&
747			    (stbuf.st_mode & S_IFMT) == S_IFREG) {
748				if (mode == RRQ) {
749					if ((stbuf.st_mode & S_IROTH) != 0)
750						break;
751				} else {
752					if ((stbuf.st_mode & S_IWOTH) != 0)
753						break;
754				}
755				err = EACCESS;
756			}
757		}
758		if (dirp->name != NULL)
759			*filep = filename = pathname;
760		else if (mode == RRQ)
761			return (err);
762		else if (err != ENOTFOUND || !create_new)
763			return (err);
764	}
765
766	/*
767	 * This option is handled here because it (might) require(s) the
768	 * size of the file.
769	 */
770	option_tsize(peer, NULL, mode, &stbuf);
771
772	if (mode == RRQ)
773		fd = open(filename, O_RDONLY);
774	else {
775		if (create_new) {
776			if (increase_name) {
777				error = find_next_name(filename, &fd);
778				if (error > 0)
779					return (error + 100);
780			} else
781				fd = open(filename,
782				    O_WRONLY | O_TRUNC | O_CREAT,
783				    S_IRUSR | S_IWUSR | S_IRGRP |
784				    S_IWGRP | S_IROTH | S_IWOTH );
785		} else
786			fd = open(filename, O_WRONLY | O_TRUNC);
787	}
788	if (fd < 0)
789		return (errno + 100);
790	file = fdopen(fd, (mode == RRQ)? "r":"w");
791	if (file == NULL) {
792		close(fd);
793		return (errno + 100);
794	}
795	return (0);
796}
797
798static void
799tftp_xmitfile(int peer, const char *mode)
800{
801	uint16_t block;
802	time_t now;
803	struct tftp_stats ts;
804
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
818static void
819tftp_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