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/11/libexec/tftpd/tftpd.c 339051 2018-10-01 15:47:34Z 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		if (setgroups(1, &nobody->pw_gid) != 0) {
376			tftp_log(LOG_ERR, "setgroups failed");
377			exit(1);
378		}
379		if (setuid(nobody->pw_uid) != 0) {
380			tftp_log(LOG_ERR, "setuid failed");
381			exit(1);
382		}
383	}
384
385	len = sizeof(me_sock);
386	if (getsockname(0, (struct sockaddr *)&me_sock, &len) == 0) {
387		switch (me_sock.ss_family) {
388		case AF_INET:
389			((struct sockaddr_in *)&me_sock)->sin_port = 0;
390			break;
391		case AF_INET6:
392			((struct sockaddr_in6 *)&me_sock)->sin6_port = 0;
393			break;
394		default:
395			/* unsupported */
396			break;
397		}
398	} else {
399		memset(&me_sock, 0, sizeof(me_sock));
400		me_sock.ss_family = peer_sock.ss_family;
401		me_sock.ss_len = peer_sock.ss_len;
402	}
403	close(0);
404	close(1);
405	peer = socket(peer_sock.ss_family, SOCK_DGRAM, 0);
406	if (peer < 0) {
407		tftp_log(LOG_ERR, "socket: %s", strerror(errno));
408		exit(1);
409	}
410	if (bind(peer, (struct sockaddr *)&me_sock, me_sock.ss_len) < 0) {
411		tftp_log(LOG_ERR, "bind: %s", strerror(errno));
412		exit(1);
413	}
414
415	tp = (struct tftphdr *)recvbuffer;
416	tp->th_opcode = ntohs(tp->th_opcode);
417	if (tp->th_opcode == RRQ) {
418		if (allow_ro)
419			tftp_rrq(peer, tp->th_stuff, n - 1);
420		else {
421			tftp_log(LOG_WARNING,
422			    "%s read access denied", peername);
423			exit(1);
424		}
425	} else if (tp->th_opcode == WRQ) {
426		if (allow_wo)
427			tftp_wrq(peer, tp->th_stuff, n - 1);
428		else {
429			tftp_log(LOG_WARNING,
430			    "%s write access denied", peername);
431			exit(1);
432		}
433	} else
434		send_error(peer, EBADOP);
435	exit(1);
436}
437
438static void
439reduce_path(char *fn)
440{
441	char *slash, *ptr;
442
443	/* Reduce all "/+./" to "/" (just in case we've got "/./../" later */
444	while ((slash = strstr(fn, "/./")) != NULL) {
445		for (ptr = slash; ptr > fn && ptr[-1] == '/'; ptr--)
446			;
447		slash += 2;
448		while (*slash)
449			*++ptr = *++slash;
450	}
451
452	/* Now reduce all "/something/+../" to "/" */
453	while ((slash = strstr(fn, "/../")) != NULL) {
454		if (slash == fn)
455			break;
456		for (ptr = slash; ptr > fn && ptr[-1] == '/'; ptr--)
457			;
458		for (ptr--; ptr >= fn; ptr--)
459			if (*ptr == '/')
460				break;
461		if (ptr < fn)
462			break;
463		slash += 3;
464		while (*slash)
465			*++ptr = *++slash;
466	}
467}
468
469static char *
470parse_header(int peer, char *recvbuffer, ssize_t size,
471	char **filename, char **mode)
472{
473	char	*cp;
474	int	i;
475	struct formats *pf;
476
477	*mode = NULL;
478	cp = recvbuffer;
479
480	i = get_field(peer, recvbuffer, size);
481	if (i >= PATH_MAX) {
482		tftp_log(LOG_ERR, "Bad option - filename too long");
483		send_error(peer, EBADOP);
484		exit(1);
485	}
486	*filename = recvbuffer;
487	tftp_log(LOG_INFO, "Filename: '%s'", *filename);
488	cp += i;
489
490	i = get_field(peer, cp, size);
491	*mode = cp;
492	cp += i;
493
494	/* Find the file transfer mode */
495	for (cp = *mode; *cp; cp++)
496		if (isupper(*cp))
497			*cp = tolower(*cp);
498	for (pf = formats; pf->f_mode; pf++)
499		if (strcmp(pf->f_mode, *mode) == 0)
500			break;
501	if (pf->f_mode == NULL) {
502		tftp_log(LOG_ERR,
503		    "Bad option - Unknown transfer mode (%s)", *mode);
504		send_error(peer, EBADOP);
505		exit(1);
506	}
507	tftp_log(LOG_INFO, "Mode: '%s'", *mode);
508
509	return (cp + 1);
510}
511
512/*
513 * WRQ - receive a file from the client
514 */
515void
516tftp_wrq(int peer, char *recvbuffer, ssize_t size)
517{
518	char *cp;
519	int has_options = 0, ecode;
520	char *filename, *mode;
521	char fnbuf[PATH_MAX];
522
523	cp = parse_header(peer, recvbuffer, size, &filename, &mode);
524	size -= (cp - recvbuffer) + 1;
525
526	strlcpy(fnbuf, filename, sizeof(fnbuf));
527	reduce_path(fnbuf);
528	filename = fnbuf;
529
530	if (size > 0) {
531		if (options_rfc_enabled)
532			has_options = !parse_options(peer, cp, size);
533		else
534			tftp_log(LOG_INFO, "Options found but not enabled");
535	}
536
537	ecode = validate_access(peer, &filename, WRQ);
538	if (ecode == 0) {
539		if (has_options)
540			send_oack(peer);
541		else
542			send_ack(peer, 0);
543	}
544	if (logging) {
545		tftp_log(LOG_INFO, "%s: write request for %s: %s", peername,
546			    filename, errtomsg(ecode));
547	}
548
549	if (ecode) {
550		send_error(peer, ecode);
551		exit(1);
552	}
553	tftp_recvfile(peer, mode);
554	exit(0);
555}
556
557/*
558 * RRQ - send a file to the client
559 */
560void
561tftp_rrq(int peer, char *recvbuffer, ssize_t size)
562{
563	char *cp;
564	int has_options = 0, ecode;
565	char *filename, *mode;
566	char	fnbuf[PATH_MAX];
567
568	cp = parse_header(peer, recvbuffer, size, &filename, &mode);
569	size -= (cp - recvbuffer) + 1;
570
571	strlcpy(fnbuf, filename, sizeof(fnbuf));
572	reduce_path(fnbuf);
573	filename = fnbuf;
574
575	if (size > 0) {
576		if (options_rfc_enabled)
577			has_options = !parse_options(peer, cp, size);
578		else
579			tftp_log(LOG_INFO, "Options found but not enabled");
580	}
581
582	ecode = validate_access(peer, &filename, RRQ);
583	if (ecode == 0) {
584		if (has_options) {
585			int n;
586			char lrecvbuffer[MAXPKTSIZE];
587			struct tftphdr *rp = (struct tftphdr *)lrecvbuffer;
588
589			send_oack(peer);
590			n = receive_packet(peer, lrecvbuffer, MAXPKTSIZE,
591				NULL, timeoutpacket);
592			if (n < 0) {
593				if (debug&DEBUG_SIMPLE)
594					tftp_log(LOG_DEBUG, "Aborting: %s",
595					    rp_strerror(n));
596				return;
597			}
598			if (rp->th_opcode != ACK) {
599				if (debug&DEBUG_SIMPLE)
600					tftp_log(LOG_DEBUG,
601					    "Expected ACK, got %s on OACK",
602					    packettype(rp->th_opcode));
603				return;
604			}
605		}
606	}
607
608	if (logging)
609		tftp_log(LOG_INFO, "%s: read request for %s: %s", peername,
610			    filename, errtomsg(ecode));
611
612	if (ecode) {
613		/*
614		 * Avoid storms of naks to a RRQ broadcast for a relative
615		 * bootfile pathname from a diskless Sun.
616		 */
617		if (suppress_naks && *filename != '/' && ecode == ENOTFOUND)
618			exit(0);
619		send_error(peer, ecode);
620		exit(1);
621	}
622	tftp_xmitfile(peer, mode);
623}
624
625/*
626 * Find the next value for YYYYMMDD.nn when the file to be written should
627 * be unique. Due to the limitations of nn, we will fail if nn reaches 100.
628 * Besides, that is four updates per hour on a file, which is kind of
629 * execessive anyway.
630 */
631static int
632find_next_name(char *filename, int *fd)
633{
634	int i;
635	time_t tval;
636	size_t len;
637	struct tm lt;
638	char yyyymmdd[MAXPATHLEN];
639	char newname[MAXPATHLEN];
640
641	/* Create the YYYYMMDD part of the filename */
642	time(&tval);
643	lt = *localtime(&tval);
644	len = strftime(yyyymmdd, sizeof(yyyymmdd), newfile_format, &lt);
645	if (len == 0) {
646		syslog(LOG_WARNING,
647			"Filename suffix too long (%d characters maximum)",
648			MAXPATHLEN);
649		return (EACCESS);
650	}
651
652	/* Make sure the new filename is not too long */
653	if (strlen(filename) > MAXPATHLEN - len - 5) {
654		syslog(LOG_WARNING,
655			"Filename too long (%zd characters, %zd maximum)",
656			strlen(filename), MAXPATHLEN - len - 5);
657		return (EACCESS);
658	}
659
660	/* Find the first file which doesn't exist */
661	for (i = 0; i < 100; i++) {
662		sprintf(newname, "%s.%s.%02d", filename, yyyymmdd, i);
663		*fd = open(newname,
664		    O_WRONLY | O_CREAT | O_EXCL,
665		    S_IRUSR | S_IWUSR | S_IRGRP |
666		    S_IWGRP | S_IROTH | S_IWOTH);
667		if (*fd > 0)
668			return 0;
669	}
670
671	return (EEXIST);
672}
673
674/*
675 * Validate file access.  Since we
676 * have no uid or gid, for now require
677 * file to exist and be publicly
678 * readable/writable.
679 * If we were invoked with arguments
680 * from inetd then the file must also be
681 * in one of the given directory prefixes.
682 * Note also, full path name must be
683 * given as we have no login directory.
684 */
685int
686validate_access(int peer, char **filep, int mode)
687{
688	struct stat stbuf;
689	int	fd;
690	int	error;
691	struct dirlist *dirp;
692	static char pathname[MAXPATHLEN];
693	char *filename = *filep;
694
695	/*
696	 * Prevent tricksters from getting around the directory restrictions
697	 */
698	if (strstr(filename, "/../"))
699		return (EACCESS);
700
701	if (*filename == '/') {
702		/*
703		 * Allow the request if it's in one of the approved locations.
704		 * Special case: check the null prefix ("/") by looking
705		 * for length = 1 and relying on the arg. processing that
706		 * it's a /.
707		 */
708		for (dirp = dirs; dirp->name != NULL; dirp++) {
709			if (dirp->len == 1 ||
710			    (!strncmp(filename, dirp->name, dirp->len) &&
711			     filename[dirp->len] == '/'))
712				    break;
713		}
714		/* If directory list is empty, allow access to any file */
715		if (dirp->name == NULL && dirp != dirs)
716			return (EACCESS);
717		if (stat(filename, &stbuf) < 0)
718			return (errno == ENOENT ? ENOTFOUND : EACCESS);
719		if ((stbuf.st_mode & S_IFMT) != S_IFREG)
720			return (ENOTFOUND);
721		if (mode == RRQ) {
722			if ((stbuf.st_mode & S_IROTH) == 0)
723				return (EACCESS);
724		} else {
725			if ((stbuf.st_mode & S_IWOTH) == 0)
726				return (EACCESS);
727		}
728	} else {
729		int err;
730
731		/*
732		 * Relative file name: search the approved locations for it.
733		 * Don't allow write requests that avoid directory
734		 * restrictions.
735		 */
736
737		if (!strncmp(filename, "../", 3))
738			return (EACCESS);
739
740		/*
741		 * If the file exists in one of the directories and isn't
742		 * readable, continue looking. However, change the error code
743		 * to give an indication that the file exists.
744		 */
745		err = ENOTFOUND;
746		for (dirp = dirs; dirp->name != NULL; dirp++) {
747			snprintf(pathname, sizeof(pathname), "%s/%s",
748				dirp->name, filename);
749			if (stat(pathname, &stbuf) == 0 &&
750			    (stbuf.st_mode & S_IFMT) == S_IFREG) {
751				if (mode == RRQ) {
752					if ((stbuf.st_mode & S_IROTH) != 0)
753						break;
754				} else {
755					if ((stbuf.st_mode & S_IWOTH) != 0)
756						break;
757				}
758				err = EACCESS;
759			}
760		}
761		if (dirp->name != NULL)
762			*filep = filename = pathname;
763		else if (mode == RRQ)
764			return (err);
765		else if (err != ENOTFOUND || !create_new)
766			return (err);
767	}
768
769	/*
770	 * This option is handled here because it (might) require(s) the
771	 * size of the file.
772	 */
773	option_tsize(peer, NULL, mode, &stbuf);
774
775	if (mode == RRQ)
776		fd = open(filename, O_RDONLY);
777	else {
778		if (create_new) {
779			if (increase_name) {
780				error = find_next_name(filename, &fd);
781				if (error > 0)
782					return (error + 100);
783			} else
784				fd = open(filename,
785				    O_WRONLY | O_TRUNC | O_CREAT,
786				    S_IRUSR | S_IWUSR | S_IRGRP |
787				    S_IWGRP | S_IROTH | S_IWOTH );
788		} else
789			fd = open(filename, O_WRONLY | O_TRUNC);
790	}
791	if (fd < 0)
792		return (errno + 100);
793	file = fdopen(fd, (mode == RRQ)? "r":"w");
794	if (file == NULL) {
795		close(fd);
796		return (errno + 100);
797	}
798	return (0);
799}
800
801static void
802tftp_xmitfile(int peer, const char *mode)
803{
804	uint16_t block;
805	time_t now;
806	struct tftp_stats ts;
807
808	memset(&ts, 0, sizeof(ts));
809	now = time(NULL);
810	if (debug&DEBUG_SIMPLE)
811		tftp_log(LOG_DEBUG, "Transmitting file");
812
813	read_init(0, file, mode);
814	block = 1;
815	tftp_send(peer, &block, &ts);
816	read_close();
817	if (debug&DEBUG_SIMPLE)
818		tftp_log(LOG_INFO, "Sent %jd bytes in %jd seconds",
819		    (intmax_t)ts.amount, (intmax_t)time(NULL) - now);
820}
821
822static void
823tftp_recvfile(int peer, const char *mode)
824{
825	uint16_t block;
826	struct timeval now1, now2;
827	struct tftp_stats ts;
828
829	gettimeofday(&now1, NULL);
830	if (debug&DEBUG_SIMPLE)
831		tftp_log(LOG_DEBUG, "Receiving file");
832
833	write_init(0, file, mode);
834
835	block = 0;
836	tftp_receive(peer, &block, &ts, NULL, 0);
837
838	gettimeofday(&now2, NULL);
839
840	if (debug&DEBUG_SIMPLE) {
841		double f;
842		if (now1.tv_usec > now2.tv_usec) {
843			now2.tv_usec += 1000000;
844			now2.tv_sec--;
845		}
846
847		f = now2.tv_sec - now1.tv_sec +
848		    (now2.tv_usec - now1.tv_usec) / 100000.0;
849		tftp_log(LOG_INFO,
850		    "Download of %jd bytes in %d blocks completed after %0.1f seconds\n",
851		    (intmax_t)ts.amount, block, f);
852	}
853
854	return;
855}
856