xref: /openbsd/libexec/ftpd/ftpd.c (revision e5dd7070)
1 /*	$OpenBSD: ftpd.c,v 1.229 2020/01/15 22:06:59 jan Exp $	*/
2 /*	$NetBSD: ftpd.c,v 1.15 1995/06/03 22:46:47 mycroft Exp $	*/
3 
4 /*
5  * Copyright (C) 1997 and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1985, 1988, 1990, 1992, 1993, 1994
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  */
61 
62 /*
63  * FTP server.
64  */
65 #include <sys/stat.h>
66 #include <sys/ioctl.h>
67 #include <sys/socket.h>
68 #include <sys/wait.h>
69 #include <sys/mman.h>
70 
71 #include <netinet/in.h>
72 #include <netinet/ip.h>
73 #include <netinet/tcp.h>
74 
75 #define	FTP_NAMES
76 #include <arpa/ftp.h>
77 #include <arpa/inet.h>
78 #include <arpa/telnet.h>
79 
80 #include <bsd_auth.h>
81 #include <ctype.h>
82 #include <dirent.h>
83 #include <errno.h>
84 #include <fcntl.h>
85 #include <glob.h>
86 #include <limits.h>
87 #include <login_cap.h>
88 #include <netdb.h>
89 #include <pwd.h>
90 #include <signal.h>
91 #include <stdarg.h>
92 #include <stdio.h>
93 #include <stdlib.h>
94 #include <string.h>
95 #include <syslog.h>
96 #include <time.h>
97 #include <vis.h>
98 #include <unistd.h>
99 #include <utmp.h>
100 #include <poll.h>
101 
102 #include "pathnames.h"
103 #include "monitor.h"
104 #include "extern.h"
105 
106 extern	off_t restart_point;
107 extern	char cbuf[];
108 
109 union sockunion ctrl_addr;
110 union sockunion data_source;
111 union sockunion data_dest;
112 union sockunion his_addr;
113 union sockunion pasv_addr;
114 
115 sigset_t allsigs;
116 
117 int	daemon_mode = 0;
118 int	data;
119 int	logged_in;
120 struct	passwd *pw;
121 int	debug = 0;
122 int	timeout = 900;    /* timeout after 15 minutes of inactivity */
123 int	maxtimeout = 7200;/* don't allow idle time to be set beyond 2 hours */
124 int	logging;
125 int	anon_ok = 1;
126 int	anon_only = 0;
127 unsigned int minuid = 1000;
128 int	multihome = 0;
129 int	guest;
130 int	stats;
131 int	statfd = -1;
132 int	portcheck = 1;
133 int	dochroot;
134 int	type;
135 int	form;
136 int	stru;			/* avoid C keyword */
137 int	mode;
138 int	doutmp = 0;		/* update utmp file */
139 int	nowtmp = 0;		/* do not update wtmp file */
140 int	usedefault = 1;		/* for data transfers */
141 int	pdata = -1;		/* for passive mode */
142 int	family = AF_UNSPEC;
143 volatile sig_atomic_t transflag;
144 off_t	file_size;
145 off_t	byte_count;
146 mode_t	defumask = S_IWGRP|S_IWOTH;		/* default umask value */
147 int	umaskchange = 1;		/* allow user to change umask value. */
148 char	tmpline[7];
149 char	hostname[HOST_NAME_MAX+1];
150 char	remotehost[HOST_NAME_MAX+1];
151 char	dhostname[HOST_NAME_MAX+1];
152 char	*guestpw;
153 char	ttyline[20];
154 static struct utmp utmp;	/* for utmp */
155 static	login_cap_t *lc;
156 static	auth_session_t *as;
157 static	volatile sig_atomic_t recvurg;
158 
159 int epsvall = 0;
160 
161 /*
162  * Timeout intervals for retrying connections
163  * to hosts that don't accept PORT cmds.  This
164  * is a kludge, but given the problems with TCP...
165  */
166 #define	SWAITMAX	90	/* wait at most 90 seconds */
167 #define	SWAITINT	5	/* interval between retries */
168 
169 int	swaitmax = SWAITMAX;
170 int	swaitint = SWAITINT;
171 
172 char	proctitle[BUFSIZ];	/* initial part of title */
173 
174 #define LOGCMD(cmd, file) \
175 	if (logging > 1) \
176 	    syslog(LOG_INFO,"%s %s%s", cmd, \
177 		*(file) == '/' ? "" : curdir(), file);
178 #define LOGCMD2(cmd, file1, file2) \
179 	 if (logging > 1) \
180 	    syslog(LOG_INFO,"%s %s%s %s%s", cmd, \
181 		*(file1) == '/' ? "" : curdir(), file1, \
182 		*(file2) == '/' ? "" : curdir(), file2);
183 #define LOGBYTES(cmd, file, cnt) \
184 	if (logging > 1) { \
185 		if ((cnt) == -1) \
186 		    syslog(LOG_INFO,"%s %s%s", cmd, \
187 			*(file) == '/' ? "" : curdir(), file); \
188 		else \
189 		    syslog(LOG_INFO, "%s %s%s = %lld bytes", \
190 			cmd, (*(file) == '/') ? "" : curdir(), file, \
191 			(long long)(cnt)); \
192 	}
193 
194 static void	 ack(char *);
195 static void	 sigurg(int);
196 static void	 myoob(void);
197 static int	 checkuser(char *, char *);
198 static FILE	*dataconn(char *, off_t, char *);
199 static void	 dolog(struct sockaddr *);
200 static char	*copy_dir(char *, struct passwd *);
201 static char	*curdir(void);
202 static void	 end_login(void);
203 static FILE	*getdatasock(char *);
204 static int	 guniquefd(char *, char **);
205 static void	 lostconn(int);
206 static void	 sigquit(int);
207 static int	 receive_data(FILE *, FILE *);
208 static void	 replydirname(const char *, const char *);
209 static int	 send_data(FILE *, FILE *, off_t, off_t, int);
210 static struct passwd *
211 		 sgetpwnam(char *, struct passwd *);
212 static void	 reapchild(int);
213 static void	 usage(void);
214 
215 void	 logxfer(char *, off_t, time_t);
216 void	 set_slave_signals(void);
217 
218 static char *
219 curdir(void)
220 {
221 	static char path[PATH_MAX+1];	/* path + '/' */
222 
223 	if (getcwd(path, sizeof(path)-1) == NULL)
224 		return ("");
225 	if (path[1] != '\0')		/* special case for root dir. */
226 		strlcat(path, "/", sizeof path);
227 	/* For guest account, skip / since it's chrooted */
228 	return (guest ? path+1 : path);
229 }
230 
231 char *argstr = "AdDhnlm:MSt:T:u:PUvW46";
232 
233 static void
234 usage(void)
235 {
236 	syslog(LOG_ERR,
237 	    "usage: ftpd [-46ADdlMnPSUW] [-m minuid] [-T maxtimeout] "
238 	    "[-t timeout] [-u mask]");
239 	exit(2);
240 }
241 
242 int
243 main(int argc, char *argv[])
244 {
245 	socklen_t addrlen;
246 	int ch, on = 1, tos;
247 	char line[LINE_MAX];
248 	FILE *fp;
249 	struct hostent *hp;
250 	struct sigaction sa;
251 	int error = 0;
252 	const char *errstr;
253 
254 	tzset();		/* in case no timezone database in ~ftp */
255 	sigfillset(&allsigs);	/* used to block signals while root */
256 	sigemptyset(&sa.sa_mask);
257 	sa.sa_flags = SA_RESTART;
258 
259 	while ((ch = getopt(argc, argv, argstr)) != -1) {
260 		switch (ch) {
261 		case 'A':
262 			anon_only = 1;
263 			break;
264 
265 		case 'd':
266 		case 'v':		/* deprecated */
267 			debug = 1;
268 			break;
269 
270 		case 'D':
271 			daemon_mode = 1;
272 			break;
273 
274 		case 'P':
275 			portcheck = 0;
276 			break;
277 
278 		case 'h':		/* deprecated */
279 			break;
280 
281 		case 'l':
282 			logging++;	/* > 1 == extra logging */
283 			break;
284 
285 		case 'm':
286 			minuid = strtonum(optarg, 0, UINT_MAX, &errstr);
287 			if (errstr) {
288 				syslog(LOG_ERR,
289 				    "%s is a bad value for -m, aborting",
290 				    optarg);
291 				exit(2);
292 			}
293 			break;
294 
295 		case 'M':
296 			multihome = 1;
297 			break;
298 
299 		case 'n':
300 			anon_ok = 0;
301 			break;
302 
303 		case 'S':
304 			stats = 1;
305 			break;
306 
307 		case 't':
308 			timeout = strtonum(optarg, 0, INT_MAX, &errstr);
309 			if (errstr) {
310 				syslog(LOG_ERR,
311 				    "%s is a bad value for -t, aborting",
312 				    optarg);
313 				exit(2);
314 			}
315 			if (maxtimeout < timeout)
316 				maxtimeout = timeout;
317 			break;
318 
319 		case 'T':
320 			maxtimeout = strtonum(optarg, 0, INT_MAX,
321 			    &errstr);
322 			if (errstr) {
323 				syslog(LOG_ERR,
324 				    "%s is a bad value for -T, aborting",
325 				    optarg);
326 				exit(2);
327 			}
328 			if (timeout > maxtimeout)
329 				timeout = maxtimeout;
330 			break;
331 
332 		case 'u':
333 		    {
334 			long val = 0;
335 			char *p;
336 			umaskchange = 0;
337 
338 			val = strtol(optarg, &p, 8);
339 			if (*optarg == '\0' || *p != '\0' || val < 0 ||
340 			    (val & ~ACCESSPERMS)) {
341 				syslog(LOG_ERR,
342 				    "%s is a bad value for -u, aborting",
343 				    optarg);
344 				exit(2);
345 			}
346 			defumask = val;
347 			break;
348 		    }
349 
350 		case 'U':
351 			doutmp = 1;
352 			break;
353 
354 		case 'W':
355 			nowtmp = 1;
356 			break;
357 
358 		case '4':
359 			family = AF_INET;
360 			break;
361 
362 		case '6':
363 			family = AF_INET6;
364 			break;
365 
366 		default:
367 			usage();
368 			break;
369 		}
370 	}
371 
372 	if (nowtmp && doutmp) {
373 		syslog(LOG_ERR, "options 'U' and 'W' are mutually exclusive");
374 		exit(1);
375 	}
376 
377 	(void) freopen(_PATH_DEVNULL, "w", stderr);
378 
379 	/*
380 	 * LOG_NDELAY sets up the logging connection immediately,
381 	 * necessary for anonymous ftp's that chroot and can't do it later.
382 	 */
383 	openlog("ftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
384 
385 	if (getpwnam(FTPD_PRIVSEP_USER) == NULL) {
386 		syslog(LOG_ERR, "privilege separation user %s not found",
387 		    FTPD_PRIVSEP_USER);
388 		exit(1);
389 	}
390 	endpwent();
391 
392 	if (daemon_mode) {
393 		int *fds, fd;
394 		struct pollfd *pfds;
395 		struct addrinfo hints, *res, *res0;
396 		nfds_t n, i;
397 
398 		/*
399 		 * Detach from parent.
400 		 */
401 		if (daemon(1, 1) == -1) {
402 			syslog(LOG_ERR, "failed to become a daemon");
403 			exit(1);
404 		}
405 		sa.sa_handler = reapchild;
406 		(void) sigaction(SIGCHLD, &sa, NULL);
407 
408 		memset(&hints, 0, sizeof(hints));
409 		hints.ai_family = family;
410 		hints.ai_socktype = SOCK_STREAM;
411 		hints.ai_protocol = IPPROTO_TCP;
412 		hints.ai_flags = AI_PASSIVE;
413 		error = getaddrinfo(NULL, "ftp", &hints, &res0);
414 		if (error) {
415 			syslog(LOG_ERR, "%s", gai_strerror(error));
416 			exit(1);
417 		}
418 
419 		n = 0;
420 		for (res = res0; res; res = res->ai_next)
421 			n++;
422 
423 		fds = calloc(n, sizeof(int));
424 		pfds = calloc(n, sizeof(struct pollfd));
425 		if (!fds || !pfds) {
426 			syslog(LOG_ERR, "%s", strerror(errno));
427 			exit(1);
428 		}
429 
430 		/*
431 		 * Open sockets, bind it to the FTP port, and start
432 		 * listening.
433 		 */
434 		n = 0;
435 		for (res = res0; res; res = res->ai_next) {
436 			fds[n] = socket(res->ai_family, res->ai_socktype,
437 			    res->ai_protocol);
438 			if (fds[n] == -1)
439 				continue;
440 
441 			if (setsockopt(fds[n], SOL_SOCKET, SO_KEEPALIVE,
442 			    &on, sizeof(on)) == -1) {
443 				close(fds[n]);
444 				fds[n] = -1;
445 				continue;
446 			}
447 
448 			if (setsockopt(fds[n], SOL_SOCKET, SO_REUSEADDR,
449 			    &on, sizeof(on)) == -1) {
450 				close(fds[n]);
451 				fds[n] = -1;
452 				continue;
453 			}
454 
455 			if (bind(fds[n], res->ai_addr, res->ai_addrlen) == -1) {
456 				close(fds[n]);
457 				fds[n] = -1;
458 				continue;
459 			}
460 			if (listen(fds[n], 32) == -1) {
461 				close(fds[n]);
462 				fds[n] = -1;
463 				continue;
464 			}
465 
466 			pfds[n].fd = fds[n];
467 			pfds[n].events = POLLIN;
468 			n++;
469 		}
470 		freeaddrinfo(res0);
471 
472 		if (n == 0) {
473 			syslog(LOG_ERR, "could not open control socket");
474 			exit(1);
475 		}
476 
477 		/*
478 		 * Loop forever accepting connection requests and forking off
479 		 * children to handle them.
480 		 */
481 		while (1) {
482 			if (poll(pfds, n, INFTIM) == -1) {
483 				if (errno == EINTR)
484 					continue;
485 				syslog(LOG_ERR, "poll: %m");
486 				exit(1);
487 			}
488 			for (i = 0; i < n; i++)
489 				if (pfds[i].revents & POLLIN) {
490 					addrlen = sizeof(his_addr);
491 					fd = accept(pfds[i].fd,
492 					    (struct sockaddr *)&his_addr,
493 					    &addrlen);
494 					if (fd != -1) {
495 						if (fork() == 0)
496 							goto child;
497 						close(fd);
498 					}
499 				}
500 		}
501 
502 	child:
503 		/* child */
504 		(void)dup2(fd, STDIN_FILENO);
505 		(void)dup2(fd, STDOUT_FILENO);
506 		for (i = 0; i < n; i++)
507 			close(fds[i]);
508 	} else {
509 		addrlen = sizeof(his_addr);
510 		if (getpeername(0, (struct sockaddr *)&his_addr,
511 		    &addrlen) == -1) {
512 			/* syslog(LOG_ERR, "getpeername (%s): %m", argv[0]); */
513 			exit(1);
514 		}
515 	}
516 
517 	/* set this here so klogin can use it... */
518 	(void)snprintf(ttyline, sizeof(ttyline), "ftp%ld", (long)getpid());
519 
520 	set_slave_signals();
521 
522 	addrlen = sizeof(ctrl_addr);
523 	if (getsockname(0, (struct sockaddr *)&ctrl_addr, &addrlen) == -1) {
524 		syslog(LOG_ERR, "getsockname: %m");
525 		exit(1);
526 	}
527 	if (his_addr.su_family == AF_INET6 &&
528 	    IN6_IS_ADDR_V4MAPPED(&his_addr.su_sin6.sin6_addr)) {
529 		syslog(LOG_WARNING,
530 		    "Connection from IPv4 mapped address is not supported.");
531 		reply(530, "System not available.");
532 		exit(1);
533 	}
534 	tos = IPTOS_LOWDELAY;
535 	switch (his_addr.su_family) {
536 	case AF_INET:
537 		if (setsockopt(0, IPPROTO_IP, IP_TOS, &tos,
538 		    sizeof(int)) == -1)
539 			syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
540 		break;
541 	case AF_INET6:
542 		if (setsockopt(0, IPPROTO_IPV6, IPV6_TCLASS, &tos,
543 		    sizeof(int)) == -1)
544 			syslog(LOG_WARNING, "setsockopt (IPV6_TCLASS): %m");
545 		break;
546 	}
547 	data_source.su_port = htons(ntohs(ctrl_addr.su_port) - 1);
548 
549 	/* Try to handle urgent data inline */
550 	if (setsockopt(0, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on)) == -1)
551 		syslog(LOG_ERR, "setsockopt: %m");
552 
553 	dolog((struct sockaddr *)&his_addr);
554 
555 	/*
556 	 * Set up default state
557 	 */
558 	data = -1;
559 	type = TYPE_A;
560 	form = FORM_N;
561 	stru = STRU_F;
562 	mode = MODE_S;
563 	tmpline[0] = '\0';
564 
565 	/* If logins are disabled, print out the message. */
566 	if ((fp = fopen(_PATH_NOLOGIN, "r")) != NULL) {
567 		while (fgets(line, sizeof(line), fp) != NULL) {
568 			line[strcspn(line, "\n")] = '\0';
569 			lreply(530, "%s", line);
570 		}
571 		(void) fflush(stdout);
572 		(void) fclose(fp);
573 		reply(530, "System not available.");
574 		exit(0);
575 	}
576 	if ((fp = fopen(_PATH_FTPWELCOME, "r")) != NULL) {
577 		while (fgets(line, sizeof(line), fp) != NULL) {
578 			line[strcspn(line, "\n")] = '\0';
579 			lreply(220, "%s", line);
580 		}
581 		(void) fflush(stdout);
582 		(void) fclose(fp);
583 		/* reply(220,) must follow */
584 	}
585 	(void) gethostname(hostname, sizeof(hostname));
586 
587 	/* Make sure hostname is fully qualified. */
588 	hp = gethostbyname(hostname);
589 	if (hp != NULL)
590 		strlcpy(hostname, hp->h_name, sizeof(hostname));
591 
592 	if (multihome) {
593 		error = getnameinfo((struct sockaddr *)&ctrl_addr,
594 		    ctrl_addr.su_len, dhostname, sizeof(dhostname), NULL, 0, 0);
595 	}
596 
597 	if (error != 0)
598 		reply(220, "FTP server ready.");
599 	else
600 		reply(220, "%s FTP server ready.",
601 		    (multihome ? dhostname : hostname));
602 
603 	monitor_init();
604 
605 	for (;;)
606 		(void) yyparse();
607 	/* NOTREACHED */
608 }
609 
610 /*
611  * Signal handlers.
612  */
613 /*ARGSUSED*/
614 static void
615 lostconn(int signo)
616 {
617 	struct syslog_data sdata = SYSLOG_DATA_INIT;
618 
619 	sdata.log_fac = LOG_FTP;
620 	if (debug)
621 		syslog_r(LOG_DEBUG, &sdata, "lost connection");
622 	dologout(1);
623 }
624 
625 static void
626 sigquit(int signo)
627 {
628 	struct syslog_data sdata = SYSLOG_DATA_INIT;
629 
630 	sdata.log_fac = LOG_FTP;
631 	syslog_r(LOG_DEBUG, &sdata, "got signal %s", sys_signame[signo]);
632 	dologout(1);
633 }
634 
635 /*
636  * Save the result of a getpwnam.  Used for USER command, since
637  * the data returned must not be clobbered by any other command
638  * (e.g., globbing).
639  */
640 static struct passwd *
641 sgetpwnam(char *name, struct passwd *pw)
642 {
643 	static struct passwd *save;
644 	struct passwd *old;
645 
646 	if (pw == NULL && (pw = getpwnam(name)) == NULL)
647 		return (NULL);
648 	old = save;
649 	save = pw_dup(pw);
650 	if (save == NULL) {
651 		perror_reply(421, "Local resource failure: malloc");
652 		dologout(1);
653 		/* NOTREACHED */
654 	}
655 	if (old) {
656 		explicit_bzero(old->pw_passwd, strlen(old->pw_passwd));
657 		free(old);
658 	}
659 	return (save);
660 }
661 
662 static int login_attempts;	/* number of failed login attempts */
663 static int askpasswd;		/* had user command, ask for passwd */
664 static char curname[LOGIN_NAME_MAX];	/* current USER name */
665 
666 /*
667  * USER command.
668  * Sets global passwd pointer pw if named account exists and is acceptable;
669  * sets askpasswd if a PASS command is expected.  If logged in previously,
670  * need to reset state.  If name is "ftp" or "anonymous", the name is not in
671  * _PATH_FTPUSERS, and ftp account exists, set guest and pw, then just return.
672  * If account doesn't exist, ask for passwd anyway.  Otherwise, check user
673  * requesting login privileges.  Disallow anyone who does not have a standard
674  * shell as returned by getusershell().  Disallow anyone mentioned in the file
675  * _PATH_FTPUSERS to allow people such as root and uucp to be avoided.
676  */
677 void
678 user(char *name)
679 {
680 	char *cp, *shell, *style, *host;
681 	char *class = NULL;
682 
683 	if (logged_in) {
684 		kill_slave("user already logged in");
685 		end_login();
686 	}
687 
688 	/* Close session from previous user if there was one. */
689 	if (as) {
690 		auth_close(as);
691 		as = NULL;
692 	}
693 	if (lc) {
694 		login_close(lc);
695 		lc = NULL;
696 	}
697 
698 	if ((style = strchr(name, ':')) != NULL)
699 		*style++ = 0;
700 
701 	guest = 0;
702 	askpasswd = 0;
703 	host = multihome ? dhostname : hostname;
704 	if (anon_ok &&
705 	    (strcmp(name, "ftp") == 0 || strcmp(name, "anonymous") == 0)) {
706 		if (checkuser(_PATH_FTPUSERS, "ftp") ||
707 		    checkuser(_PATH_FTPUSERS, "anonymous"))
708 			reply(530, "User %s access denied.", name);
709 		else if ((pw = sgetpwnam("ftp", NULL)) != NULL) {
710 			if ((lc = login_getclass(pw->pw_class)) == NULL ||
711 			    (as = auth_open()) == NULL ||
712 			    auth_setpwd(as, pw) != 0 ||
713 			    auth_setoption(as, "FTPD_HOST", host) < 0) {
714 				if (as) {
715 					auth_close(as);
716 					as = NULL;
717 				}
718 				if (lc) {
719 					login_close(lc);
720 					lc = NULL;
721 				}
722 				reply(421, "Local resource failure");
723 				return;
724 			}
725 			guest = 1;
726 			askpasswd = 1;
727 			reply(331,
728 			"Guest login ok, send your email address as password.");
729 		} else
730 			reply(530, "User %s unknown.", name);
731 		if (!askpasswd && logging)
732 			syslog(LOG_NOTICE,
733 			    "ANONYMOUS FTP LOGIN REFUSED FROM %s", remotehost);
734 		return;
735 	}
736 
737 	shell = _PATH_BSHELL;
738 	if ((pw = sgetpwnam(name, NULL))) {
739 		class = pw->pw_class;
740 		if (pw->pw_shell != NULL && *pw->pw_shell != '\0')
741 			shell = pw->pw_shell;
742 		while ((cp = getusershell()) != NULL)
743 			if (strcmp(cp, shell) == 0)
744 				break;
745 		shell = cp;
746 		endusershell();
747 	}
748 
749 	/* Get login class; if invalid style treat like unknown user. */
750 	lc = login_getclass(class);
751 	if (lc && (style = login_getstyle(lc, style, "auth-ftp")) == NULL) {
752 		login_close(lc);
753 		lc = NULL;
754 		pw = NULL;
755 	}
756 
757 	/* Do pre-authentication setup. */
758 	if (lc && ((as = auth_open()) == NULL ||
759 	    (pw != NULL && auth_setpwd(as, pw) != 0) ||
760 	    auth_setitem(as, AUTHV_STYLE, style) < 0 ||
761 	    auth_setitem(as, AUTHV_NAME, name) < 0 ||
762 	    auth_setitem(as, AUTHV_CLASS, class) < 0 ||
763 	    auth_setoption(as, "login", "yes") < 0 ||
764 	    auth_setoption(as, "notickets", "yes") < 0 ||
765 	    auth_setoption(as, "FTPD_HOST", host) < 0)) {
766 		if (as) {
767 			auth_close(as);
768 			as = NULL;
769 		}
770 		login_close(lc);
771 		lc = NULL;
772 		reply(421, "Local resource failure");
773 		return;
774 	}
775 	if (logging)
776 		strlcpy(curname, name, sizeof(curname));
777 
778 	dochroot = (lc && login_getcapbool(lc, "ftp-chroot", 0)) ||
779 	    checkuser(_PATH_FTPCHROOT, name);
780 	if (anon_only && !dochroot) {
781 		reply(530, "User %s access denied.", name);
782 		return;
783 	}
784 	if (pw) {
785 		if (pw->pw_uid < minuid) {
786 			reply(530, "User %s access denied.", name);
787 			if (logging)
788 				syslog(LOG_NOTICE,
789 				    "FTP LOGIN REFUSED FROM %s, %s (UID))",
790 				    remotehost, name);
791 			return;
792 		}
793 		if ((!shell && !dochroot) || checkuser(_PATH_FTPUSERS, name)) {
794 			reply(530, "User %s access denied.", name);
795 			if (logging)
796 				syslog(LOG_NOTICE,
797 				    "FTP LOGIN REFUSED FROM %s, %s",
798 				    remotehost, name);
799 			pw = NULL;
800 			return;
801 		}
802 	}
803 
804 	if (as != NULL && (cp = auth_challenge(as)) != NULL)
805 		reply(331, "%s", cp);
806 	else
807 		reply(331, "Password required for %s.", name);
808 
809 	askpasswd = 1;
810 	/*
811 	 * Delay before reading passwd after first failed
812 	 * attempt to slow down passwd-guessing programs.
813 	 */
814 	if (login_attempts)
815 		sleep((unsigned) login_attempts);
816 }
817 
818 /*
819  * Check if a user is in the file "fname"
820  */
821 static int
822 checkuser(char *fname, char *name)
823 {
824 	FILE *fp;
825 	int found = 0;
826 	char *p, line[BUFSIZ];
827 
828 	if ((fp = fopen(fname, "r")) != NULL) {
829 		while (fgets(line, sizeof(line), fp) != NULL)
830 			if ((p = strchr(line, '\n')) != NULL) {
831 				*p = '\0';
832 				if (line[0] == '#')
833 					continue;
834 				if (strcmp(line, name) == 0) {
835 					found = 1;
836 					break;
837 				}
838 			}
839 		(void) fclose(fp);
840 	}
841 	return (found);
842 }
843 
844 /*
845  * Terminate login as previous user, if any, resetting state;
846  * used when USER command is given or login fails.
847  */
848 static void
849 end_login(void)
850 {
851 	sigprocmask (SIG_BLOCK, &allsigs, NULL);
852 	if (logged_in) {
853 		if (!nowtmp)
854 			ftpdlogwtmp(ttyline, "", "");
855 		if (doutmp)
856 			ftpd_logout(utmp.ut_line);
857 	}
858 	reply(530, "Please reconnect to work as another user");
859 	_exit(0);
860 }
861 
862 enum auth_ret
863 pass(char *passwd)
864 {
865 	int authok;
866 	unsigned int flags;
867 	FILE *fp;
868 	static char homedir[PATH_MAX];
869 	char *motd, *dir, rootdir[PATH_MAX];
870 	size_t sz_pw_dir;
871 
872 	if (logged_in || askpasswd == 0) {
873 		reply(503, "Login with USER first.");
874 		return (AUTH_FAILED);
875 	}
876 	askpasswd = 0;
877 	if (!guest) {		/* "ftp" is only account allowed no password */
878 		authok = 0;
879 		if (pw == NULL || pw->pw_passwd[0] == '\0') {
880 			useconds_t us;
881 
882 			/* Sleep between 1 and 3 seconds to emulate a crypt. */
883 			us = arc4random_uniform(3000000);
884 			usleep(us);
885 			if (as != NULL) {
886 				auth_close(as);
887 				as = NULL;
888 			}
889 		} else {
890 			authok = auth_userresponse(as, passwd, 0);
891 			as = NULL;
892 		}
893 		if (authok == 0) {
894 			reply(530, "Login incorrect.");
895 			if (logging)
896 				syslog(LOG_NOTICE,
897 				    "FTP LOGIN FAILED FROM %s, %s",
898 				    remotehost, curname);
899 			pw = NULL;
900 			if (login_attempts++ >= 5) {
901 				syslog(LOG_NOTICE,
902 				    "repeated login failures from %s",
903 				    remotehost);
904 				kill_slave("repeated login failures");
905 				_exit(0);
906 			}
907 			return (AUTH_FAILED);
908 		}
909 	} else if (lc != NULL) {
910 		/* Save anonymous' password. */
911 		free(guestpw);
912 		guestpw = strdup(passwd);
913 		if (guestpw == NULL) {
914 			kill_slave("out of mem");
915 			fatal("Out of memory.");
916 		}
917 
918 		authok = auth_approval(as, lc, pw->pw_name, "ftp");
919 		auth_close(as);
920 		as = NULL;
921 		if (authok == 0) {
922 			syslog(LOG_INFO|LOG_AUTH,
923 			    "FTP LOGIN FAILED (HOST) as %s: approval failure.",
924 			    pw->pw_name);
925 			reply(530, "Approval failure.");
926 			kill_slave("approval failure");
927 			_exit(0);
928 		}
929 	} else {
930 		syslog(LOG_INFO|LOG_AUTH,
931 		    "FTP LOGIN CLASS %s MISSING for %s: approval failure.",
932 		    pw->pw_class, pw->pw_name);
933 		reply(530, "Permission denied.");
934 		kill_slave("permission denied");
935 		_exit(0);
936 	}
937 
938 	if (monitor_post_auth() == 1) {
939 		/* Post-auth monitor process */
940 		logged_in = 1;
941 		return (AUTH_MONITOR);
942 	}
943 
944 	login_attempts = 0;		/* this time successful */
945 	/* set umask via setusercontext() unless -u flag was given. */
946 	flags = LOGIN_SETGROUP|LOGIN_SETPRIORITY|LOGIN_SETRESOURCES;
947 	if (umaskchange)
948 		flags |= LOGIN_SETUMASK;
949 	else
950 		(void) umask(defumask);
951 	if (setusercontext(lc, pw, 0, flags) != 0) {
952 		perror_reply(421, "Local resource failure: setusercontext");
953 		syslog(LOG_NOTICE, "setusercontext: %m");
954 		dologout(1);
955 		/* NOTREACHED */
956 	}
957 
958 	/* open wtmp before chroot */
959 	if (!nowtmp)
960 		ftpdlogwtmp(ttyline, pw->pw_name, remotehost);
961 
962 	/* open utmp before chroot */
963 	if (doutmp) {
964 		memset(&utmp, 0, sizeof(utmp));
965 		(void)time(&utmp.ut_time);
966 		(void)strncpy(utmp.ut_name, pw->pw_name, sizeof(utmp.ut_name));
967 		(void)strncpy(utmp.ut_host, remotehost, sizeof(utmp.ut_host));
968 		(void)strncpy(utmp.ut_line, ttyline, sizeof(utmp.ut_line));
969 		ftpd_login(&utmp);
970 	}
971 
972 	/* open stats file before chroot */
973 	if (guest && (stats == 1) && (statfd < 0))
974 		if ((statfd = open(_PATH_FTPDSTATFILE, O_WRONLY|O_APPEND)) == -1)
975 			stats = 0;
976 
977 	logged_in = 1;
978 
979 	if ((dir = login_getcapstr(lc, "ftp-dir", NULL, NULL))) {
980 		char *newdir;
981 
982 		newdir = copy_dir(dir, pw);
983 		if (newdir == NULL) {
984 			perror_reply(421, "Local resource failure: malloc");
985 			dologout(1);
986 			/* NOTREACHED */
987 		}
988 		pw->pw_dir = newdir;
989 		pw = sgetpwnam(NULL, pw);
990 		free(dir);
991 		free(newdir);
992 	}
993 
994 	/* make sure pw->pw_dir is big enough to hold "/" */
995 	sz_pw_dir = strlen(pw->pw_dir) + 1;
996 	if (sz_pw_dir < 2) {
997 		pw->pw_dir = "/";
998 		pw = sgetpwnam(NULL, pw);
999 		sz_pw_dir = 2;
1000 	}
1001 
1002 	if (guest || dochroot) {
1003 		if (multihome && guest) {
1004 			struct stat ts;
1005 
1006 			/* Compute root directory. */
1007 			snprintf(rootdir, sizeof(rootdir), "%s/%s",
1008 			    pw->pw_dir, dhostname);
1009 			if (stat(rootdir, &ts) == -1) {
1010 				snprintf(rootdir, sizeof(rootdir), "%s/%s",
1011 				    pw->pw_dir, hostname);
1012 			}
1013 		} else
1014 			strlcpy(rootdir, pw->pw_dir, sizeof(rootdir));
1015 	}
1016 	if (guest) {
1017 		/*
1018 		 * We MUST do a chdir() after the chroot. Otherwise
1019 		 * the old current directory will be accessible as "."
1020 		 * outside the new root!
1021 		 */
1022 		if (chroot(rootdir) == -1 || chdir("/") == -1) {
1023 			reply(550, "Can't set guest privileges.");
1024 			goto bad;
1025 		}
1026 		strlcpy(pw->pw_dir, "/", sz_pw_dir);
1027 		if (setenv("HOME", "/", 1) == -1) {
1028 			reply(550, "Can't setup environment.");
1029 			goto bad;
1030 		}
1031 	} else if (dochroot) {
1032 		if (chroot(rootdir) == -1 || chdir("/") == -1) {
1033 			reply(550, "Can't change root.");
1034 			goto bad;
1035 		}
1036 		strlcpy(pw->pw_dir, "/", sz_pw_dir);
1037 		if (setenv("HOME", "/", 1) == -1) {
1038 			reply(550, "Can't setup environment.");
1039 			goto bad;
1040 		}
1041 	} else if (chdir(pw->pw_dir) == -1) {
1042 		if (chdir("/") == -1) {
1043 			reply(530, "User %s: can't change directory to %s.",
1044 			    pw->pw_name, pw->pw_dir);
1045 			goto bad;
1046 		} else
1047 			lreply(230, "No directory! Logging in with home=/");
1048 	}
1049 	if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) {
1050 		reply(550, "Can't set gid.");
1051 		goto bad;
1052 	}
1053 	if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) {
1054 		reply(550, "Can't set uid.");
1055 		goto bad;
1056 	}
1057 	sigprocmask(SIG_UNBLOCK, &allsigs, NULL);
1058 
1059 	/*
1060 	 * Set home directory so that use of ~ (tilde) works correctly.
1061 	 */
1062 	if (getcwd(homedir, PATH_MAX) != NULL) {
1063 		if (setenv("HOME", homedir, 1) == -1) {
1064 			reply(550, "Can't setup environment.");
1065 			goto bad;
1066 		}
1067 	}
1068 
1069 	/*
1070 	 * Display a login message, if it exists.
1071 	 * N.B. reply(230,) must follow the message.
1072 	 */
1073 	motd = login_getcapstr(lc, "welcome", NULL, NULL);
1074 	if ((fp = fopen(motd ? motd : _PATH_FTPLOGINMESG, "r")) != NULL) {
1075 		char line[LINE_MAX];
1076 
1077 		while (fgets(line, sizeof(line), fp) != NULL) {
1078 			line[strcspn(line, "\n")] = '\0';
1079 			lreply(230, "%s", line);
1080 		}
1081 		(void) fflush(stdout);
1082 		(void) fclose(fp);
1083 	}
1084 	free(motd);
1085 	if (guest) {
1086 		reply(230, "Guest login ok, access restrictions apply.");
1087 		snprintf(proctitle, sizeof(proctitle),
1088 		    "%s: anonymous/%.*s", remotehost,
1089 		    (int)(sizeof(proctitle) - sizeof(remotehost) -
1090 		    sizeof(": anonymous/")), passwd);
1091 		setproctitle("%s", proctitle);
1092 		if (logging)
1093 			syslog(LOG_INFO, "ANONYMOUS FTP LOGIN FROM %s, %s",
1094 			    remotehost, passwd);
1095 	} else {
1096 		reply(230, "User %s logged in.", pw->pw_name);
1097 		snprintf(proctitle, sizeof(proctitle),
1098 		    "%s: %s", remotehost, pw->pw_name);
1099 		setproctitle("%s", proctitle);
1100 		if (logging)
1101 			syslog(LOG_INFO, "FTP LOGIN FROM %s as %s",
1102 			    remotehost, pw->pw_name);
1103 	}
1104 	login_close(lc);
1105 	lc = NULL;
1106 	return (AUTH_SLAVE);
1107 bad:
1108 	/* Forget all about it... */
1109 	login_close(lc);
1110 	lc = NULL;
1111 	end_login();
1112 	return (AUTH_FAILED);
1113 }
1114 
1115 void
1116 retrieve(enum ret_cmd cmd, char *name)
1117 {
1118 	FILE *fin, *dout;
1119 	struct stat st;
1120 	pid_t pid;
1121 	time_t start;
1122 
1123 	if (cmd == RET_FILE) {
1124 		fin = fopen(name, "r");
1125 		st.st_size = 0;
1126 	} else {
1127 		fin = ftpd_ls(name, &pid);
1128 		st.st_size = -1;
1129 		st.st_blksize = BUFSIZ;
1130 	}
1131 	if (fin == NULL) {
1132 		if (errno != 0) {
1133 			perror_reply(550, name);
1134 			if (cmd == RET_FILE) {
1135 				LOGCMD("get", name);
1136 			}
1137 		}
1138 		return;
1139 	}
1140 	byte_count = -1;
1141 	if (cmd == RET_FILE &&
1142 	    (fstat(fileno(fin), &st) == -1 || !S_ISREG(st.st_mode))) {
1143 		reply(550, "%s: not a plain file.", name);
1144 		goto done;
1145 	}
1146 	if (restart_point) {
1147 		if (type == TYPE_A) {
1148 			off_t i, n;
1149 			int c;
1150 
1151 			n = restart_point;
1152 			i = 0;
1153 			while (i++ < n) {
1154 				if ((c = getc(fin)) == EOF) {
1155 					if (ferror(fin)) {
1156 						perror_reply(550, name);
1157 						goto done;
1158 					} else
1159 						break;
1160 				}
1161 				if (c == '\n')
1162 					i++;
1163 			}
1164 		} else if (lseek(fileno(fin), restart_point, SEEK_SET) == -1) {
1165 			perror_reply(550, name);
1166 			goto done;
1167 		}
1168 	}
1169 	dout = dataconn(name, st.st_size, "w");
1170 	if (dout == NULL)
1171 		goto done;
1172 	time(&start);
1173 	send_data(fin, dout, st.st_blksize, st.st_size,
1174 	    (restart_point == 0 && cmd == RET_FILE && S_ISREG(st.st_mode)));
1175 	if ((cmd == RET_FILE) && stats)
1176 		logxfer(name, byte_count, start);
1177 	(void) fclose(dout);
1178 	data = -1;
1179 done:
1180 	if (pdata >= 0)
1181 		(void) close(pdata);
1182 	pdata = -1;
1183 	if (cmd == RET_FILE) {
1184 		LOGBYTES("get", name, byte_count);
1185 		fclose(fin);
1186 	} else {
1187 		ftpd_pclose(fin, pid);
1188 	}
1189 }
1190 
1191 void
1192 store(char *name, char *mode, int unique)
1193 {
1194 	FILE *fout, *din;
1195 	int (*closefunc)(FILE *);
1196 	struct stat st;
1197 	int fd;
1198 
1199 	if (restart_point && *mode != 'a')
1200 		mode = "r+";
1201 
1202 	if (unique && stat(name, &st) == 0) {
1203 		char *nam;
1204 
1205 		fd = guniquefd(name, &nam);
1206 		if (fd == -1) {
1207 			LOGCMD(*mode == 'w' ? "put" : "append", name);
1208 			return;
1209 		}
1210 		name = nam;
1211 		fout = fdopen(fd, mode);
1212 	} else
1213 		fout = fopen(name, mode);
1214 
1215 	closefunc = fclose;
1216 	if (fout == NULL) {
1217 		perror_reply(553, name);
1218 		LOGCMD(*mode == 'w' ? "put" : "append", name);
1219 		return;
1220 	}
1221 	byte_count = -1;
1222 	if (restart_point) {
1223 		if (type == TYPE_A) {
1224 			off_t i, n;
1225 			int c;
1226 
1227 			n = restart_point;
1228 			i = 0;
1229 			while (i++ < n) {
1230 				if ((c = getc(fout)) == EOF) {
1231 					if (ferror(fout)) {
1232 						perror_reply(550, name);
1233 						goto done;
1234 					} else
1235 						break;
1236 				}
1237 				if (c == '\n')
1238 					i++;
1239 			}
1240 			/*
1241 			 * We must do this seek to "current" position
1242 			 * because we are changing from reading to
1243 			 * writing.
1244 			 */
1245 			if (fseek(fout, 0, SEEK_CUR) == -1) {
1246 				perror_reply(550, name);
1247 				goto done;
1248 			}
1249 		} else if (lseek(fileno(fout), restart_point, SEEK_SET) == -1) {
1250 			perror_reply(550, name);
1251 			goto done;
1252 		}
1253 	}
1254 	din = dataconn(name, -1, "r");
1255 	if (din == NULL)
1256 		goto done;
1257 	if (receive_data(din, fout) == 0) {
1258 		if (unique)
1259 			reply(226, "Transfer complete (unique file name:%s).",
1260 			    name);
1261 		else
1262 			reply(226, "Transfer complete.");
1263 	}
1264 	(void) fclose(din);
1265 	data = -1;
1266 	pdata = -1;
1267 done:
1268 	LOGBYTES(*mode == 'w' ? "put" : "append", name, byte_count);
1269 	(*closefunc)(fout);
1270 }
1271 
1272 static FILE *
1273 getdatasock(char *mode)
1274 {
1275 	int opt, s, t, tries;
1276 
1277 	if (data >= 0)
1278 		return (fdopen(data, mode));
1279 	sigprocmask (SIG_BLOCK, &allsigs, NULL);
1280 	s = monitor_socket(ctrl_addr.su_family);
1281 	if (s < 0)
1282 		goto bad;
1283 	opt = 1;
1284 	if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
1285 	    &opt, sizeof(opt)) == -1)
1286 		goto bad;
1287 	/* anchor socket to avoid multi-homing problems */
1288 	data_source = ctrl_addr;
1289 	data_source.su_port = htons(20); /* ftp-data port */
1290 	for (tries = 1; ; tries++) {
1291 		if (monitor_bind(s, (struct sockaddr *)&data_source,
1292 		    data_source.su_len) >= 0)
1293 			break;
1294 		if (errno != EADDRINUSE || tries > 10)
1295 			goto bad;
1296 		sleep((unsigned int)tries);
1297 	}
1298 	sigprocmask (SIG_UNBLOCK, &allsigs, NULL);
1299 
1300 	opt = IPTOS_THROUGHPUT;
1301 	switch (ctrl_addr.su_family) {
1302 	case AF_INET:
1303 		if (setsockopt(s, IPPROTO_IP, IP_TOS, &opt,
1304 		    sizeof(opt)) == -1)
1305 			syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
1306 		break;
1307 	case AF_INET6:
1308 		if (setsockopt(s, IPPROTO_IPV6, IPV6_TCLASS, &opt,
1309 		    sizeof(opt)) == -1)
1310 			syslog(LOG_WARNING, "setsockopt (IPV6_TCLASS): %m");
1311 		break;
1312 	}
1313 	/*
1314 	 * Turn off push flag to keep sender TCP from sending short packets
1315 	 * at the boundaries of each write().  Should probably do a SO_SNDBUF
1316 	 * to set the send buffer size as well, but that may not be desirable
1317 	 * in heavy-load situations.
1318 	 */
1319 	opt = 1;
1320 	if (setsockopt(s, IPPROTO_TCP, TCP_NOPUSH, &opt, sizeof(opt)) == -1)
1321 		syslog(LOG_WARNING, "setsockopt (TCP_NOPUSH): %m");
1322 	opt = 65536;
1323 	if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, &opt, sizeof(opt)) == -1)
1324 		syslog(LOG_WARNING, "setsockopt (SO_SNDBUF): %m");
1325 
1326 	return (fdopen(s, mode));
1327 bad:
1328 	/* Return the real value of errno (close may change it) */
1329 	t = errno;
1330 	sigprocmask (SIG_UNBLOCK, &allsigs, NULL);
1331 	if (s >= 0)
1332 		(void) close(s);
1333 	errno = t;
1334 	return (NULL);
1335 }
1336 
1337 static FILE *
1338 dataconn(char *name, off_t size, char *mode)
1339 {
1340 	char sizebuf[32];
1341 	FILE *file = NULL;
1342 	int retry = 0;
1343 	in_port_t *p;
1344 	u_char *fa, *ha;
1345 	size_t alen;
1346 	int error;
1347 
1348 	file_size = size;
1349 	byte_count = 0;
1350 	if (size != -1) {
1351 		(void) snprintf(sizebuf, sizeof(sizebuf), " (%lld bytes)",
1352 		    (long long)size);
1353 	} else
1354 		sizebuf[0] = '\0';
1355 	if (pdata >= 0) {
1356 		union sockunion from;
1357 		int s;
1358 		socklen_t fromlen = sizeof(from);
1359 
1360 		(void) alarm ((unsigned) timeout);
1361 		s = accept(pdata, (struct sockaddr *)&from, &fromlen);
1362 		(void) alarm (0);
1363 		if (s == -1) {
1364 			reply(425, "Can't open data connection.");
1365 			(void) close(pdata);
1366 			pdata = -1;
1367 			return (NULL);
1368 		}
1369 		switch (from.su_family) {
1370 		case AF_INET:
1371 			p = (in_port_t *)&from.su_sin.sin_port;
1372 			fa = (u_char *)&from.su_sin.sin_addr;
1373 			ha = (u_char *)&his_addr.su_sin.sin_addr;
1374 			alen = sizeof(struct in_addr);
1375 			break;
1376 		case AF_INET6:
1377 			p = (in_port_t *)&from.su_sin6.sin6_port;
1378 			fa = (u_char *)&from.su_sin6.sin6_addr;
1379 			ha = (u_char *)&his_addr.su_sin6.sin6_addr;
1380 			alen = sizeof(struct in6_addr);
1381 			break;
1382 		default:
1383 			reply(425, "Can't build data connection: "
1384 			    "unknown address family");
1385 			(void) close(pdata);
1386 			(void) close(s);
1387 			pdata = -1;
1388 			return (NULL);
1389 		}
1390 		if (from.su_family != his_addr.su_family ||
1391 		    ntohs(*p) < IPPORT_RESERVED) {
1392 			reply(425, "Can't build data connection: "
1393 			    "address family or port error");
1394 			(void) close(pdata);
1395 			(void) close(s);
1396 			pdata = -1;
1397 			return (NULL);
1398 		}
1399 		if (portcheck && memcmp(fa, ha, alen) != 0) {
1400 			reply(425, "Can't build data connection: "
1401 			    "illegal port number");
1402 			(void) close(pdata);
1403 			(void) close(s);
1404 			pdata = -1;
1405 			return (NULL);
1406 		}
1407 		(void) close(pdata);
1408 		pdata = s;
1409 		reply(150, "Opening %s mode data connection for '%s'%s.",
1410 		    type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1411 		return (fdopen(pdata, mode));
1412 	}
1413 	if (data >= 0) {
1414 		reply(125, "Using existing data connection for '%s'%s.",
1415 		    name, sizebuf);
1416 		usedefault = 1;
1417 		return (fdopen(data, mode));
1418 	}
1419 	if (usedefault)
1420 		data_dest = his_addr;
1421 	usedefault = 1;
1422 	do {
1423 		if (file != NULL)
1424 			(void) fclose(file);
1425 		file = getdatasock(mode);
1426 		if (file == NULL) {
1427 			char hbuf[HOST_NAME_MAX+1], pbuf[10];
1428 
1429 			error = getnameinfo((struct sockaddr *)&data_source,
1430 			    data_source.su_len, hbuf, sizeof(hbuf), pbuf,
1431 			    sizeof(pbuf), NI_NUMERICHOST | NI_NUMERICSERV);
1432 			if (error != 0)
1433 				reply(425, "Can't create data socket: %s.",
1434 				    strerror(errno));
1435 			else
1436 				reply(425,
1437 				    "Can't create data socket (%s,%s): %s.",
1438 				    hbuf, pbuf, strerror(errno));
1439 			return (NULL);
1440 		}
1441 
1442 		/*
1443 		 * attempt to connect to reserved port on client machine;
1444 		 * this looks like an attack
1445 		 */
1446 		switch (data_dest.su_family) {
1447 		case AF_INET:
1448 			p = (in_port_t *)&data_dest.su_sin.sin_port;
1449 			fa = (u_char *)&data_dest.su_sin.sin_addr;
1450 			ha = (u_char *)&his_addr.su_sin.sin_addr;
1451 			alen = sizeof(struct in_addr);
1452 			break;
1453 		case AF_INET6:
1454 			p = (in_port_t *)&data_dest.su_sin6.sin6_port;
1455 			fa = (u_char *)&data_dest.su_sin6.sin6_addr;
1456 			ha = (u_char *)&his_addr.su_sin6.sin6_addr;
1457 			alen = sizeof(struct in6_addr);
1458 			break;
1459 		default:
1460 			reply(425, "Can't build data connection: "
1461 			    "unknown address family");
1462 			(void) fclose(file);
1463 			pdata = -1;
1464 			return (NULL);
1465 		}
1466 		if (data_dest.su_family != his_addr.su_family ||
1467 		    ntohs(*p) < IPPORT_RESERVED || ntohs(*p) == 2049) { /* XXX */
1468 			reply(425, "Can't build data connection: "
1469 			    "address family or port error");
1470 			(void) fclose(file);
1471 			return NULL;
1472 		}
1473 		if (portcheck && memcmp(fa, ha, alen) != 0) {
1474 			reply(435, "Can't build data connection: "
1475 			    "illegal port number");
1476 			(void) fclose(file);
1477 			return NULL;
1478 		}
1479 
1480 		if (connect(fileno(file), (struct sockaddr *)&data_dest,
1481 		    data_dest.su_len) == 0) {
1482 			reply(150, "Opening %s mode data connection for '%s'%s.",
1483 			    type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1484 			data = fileno(file);
1485 			return (file);
1486 		}
1487 		if (errno != EADDRINUSE)
1488 			break;
1489 		sleep((unsigned) swaitint);
1490 		retry += swaitint;
1491 	} while (retry <= swaitmax);
1492 	perror_reply(425, "Can't build data connection");
1493 	(void) fclose(file);
1494 	return (NULL);
1495 }
1496 
1497 /*
1498  * Transfer the contents of "instr" to "outstr" peer using the appropriate
1499  * encapsulation of the data subject to Mode, Structure, and Type.
1500  *
1501  * NB: Form isn't handled.
1502  */
1503 static int
1504 send_data(FILE *instr, FILE *outstr, off_t blksize, off_t filesize, int isreg)
1505 {
1506 	int c, cnt, filefd, netfd;
1507 	char *buf, *bp;
1508 	size_t len;
1509 
1510 	transflag++;
1511 	switch (type) {
1512 
1513 	case TYPE_A:
1514 		while ((c = getc(instr)) != EOF) {
1515 			if (recvurg)
1516 				goto got_oob;
1517 			byte_count++;
1518 			if (c == '\n') {
1519 				if (ferror(outstr))
1520 					goto data_err;
1521 				(void) putc('\r', outstr);
1522 			}
1523 			(void) putc(c, outstr);
1524 		}
1525 		fflush(outstr);
1526 		transflag = 0;
1527 		if (ferror(instr))
1528 			goto file_err;
1529 		if (ferror(outstr))
1530 			goto data_err;
1531 		reply(226, "Transfer complete.");
1532 		return(0);
1533 
1534 	case TYPE_I:
1535 	case TYPE_L:
1536 		/*
1537 		 * isreg is only set if we are not doing restart and we
1538 		 * are sending a regular file
1539 		 */
1540 		netfd = fileno(outstr);
1541 		filefd = fileno(instr);
1542 
1543 		if (isreg && filesize < 16 * 1024 * 1024) {
1544 			size_t fsize = (size_t)filesize;
1545 
1546 			if (fsize == 0) {
1547 				transflag = 0;
1548 				reply(226, "Transfer complete.");
1549 				return(0);
1550 			}
1551 
1552 			buf = mmap(0, fsize, PROT_READ, MAP_SHARED, filefd, 0);
1553 			if (buf == MAP_FAILED) {
1554 				syslog(LOG_WARNING, "mmap(%llu): %m",
1555 				    (unsigned long long)fsize);
1556 				goto oldway;
1557 			}
1558 			bp = buf;
1559 			len = fsize;
1560 			do {
1561 				cnt = write(netfd, bp, len);
1562 				if (recvurg) {
1563 					munmap(buf, fsize);
1564 					goto got_oob;
1565 				}
1566 				len -= cnt;
1567 				bp += cnt;
1568 				if (cnt > 0)
1569 					byte_count += cnt;
1570 			} while(cnt > 0 && len > 0);
1571 
1572 			transflag = 0;
1573 			munmap(buf, fsize);
1574 			if (cnt < 0)
1575 				goto data_err;
1576 			reply(226, "Transfer complete.");
1577 			return(0);
1578 		}
1579 
1580 oldway:
1581 		if ((buf = malloc((size_t)blksize)) == NULL) {
1582 			transflag = 0;
1583 			perror_reply(451, "Local resource failure: malloc");
1584 			return(-1);
1585 		}
1586 
1587 		while ((cnt = read(filefd, buf, (size_t)blksize)) > 0 &&
1588 		    write(netfd, buf, cnt) == cnt)
1589 			byte_count += cnt;
1590 		transflag = 0;
1591 		(void)free(buf);
1592 		if (cnt != 0) {
1593 			if (cnt == -1)
1594 				goto file_err;
1595 			goto data_err;
1596 		}
1597 		reply(226, "Transfer complete.");
1598 		return(0);
1599 	default:
1600 		transflag = 0;
1601 		reply(550, "Unimplemented TYPE %d in send_data", type);
1602 		return(-1);
1603 	}
1604 
1605 data_err:
1606 	transflag = 0;
1607 	reply(426, "Data connection");
1608 	return(-1);
1609 
1610 file_err:
1611 	transflag = 0;
1612 	reply(551, "Error on input file");
1613 	return(-1);
1614 
1615 got_oob:
1616 	myoob();
1617 	recvurg = 0;
1618 	transflag = 0;
1619 	return(-1);
1620 }
1621 
1622 /*
1623  * Transfer data from peer to "outstr" using the appropriate encapulation of
1624  * the data subject to Mode, Structure, and Type.
1625  *
1626  * N.B.: Form isn't handled.
1627  */
1628 static int
1629 receive_data(FILE *instr, FILE *outstr)
1630 {
1631 	int c;
1632 	int cnt;
1633 	char buf[BUFSIZ];
1634 	struct sigaction sa, sa_saved;
1635 	volatile int bare_lfs = 0;
1636 
1637 	transflag++;
1638 	switch (type) {
1639 
1640 	case TYPE_I:
1641 	case TYPE_L:
1642 		memset(&sa, 0, sizeof(sa));
1643 		sigfillset(&sa.sa_mask);
1644 		sa.sa_flags = SA_RESTART;
1645 		sa.sa_handler = lostconn;
1646 		(void) sigaction(SIGALRM, &sa, &sa_saved);
1647 		do {
1648 			(void) alarm ((unsigned) timeout);
1649 			cnt = read(fileno(instr), buf, sizeof(buf));
1650 			(void) alarm (0);
1651 			if (recvurg)
1652 				goto got_oob;
1653 
1654 			if (cnt > 0) {
1655 				if (write(fileno(outstr), buf, cnt) != cnt)
1656 					goto file_err;
1657 				byte_count += cnt;
1658 			}
1659 		} while (cnt > 0);
1660 		(void) sigaction(SIGALRM, &sa_saved, NULL);
1661 		if (cnt == -1)
1662 			goto data_err;
1663 		transflag = 0;
1664 		return (0);
1665 
1666 	case TYPE_E:
1667 		reply(553, "TYPE E not implemented.");
1668 		transflag = 0;
1669 		return (-1);
1670 
1671 	case TYPE_A:
1672 		while ((c = getc(instr)) != EOF) {
1673 			if (recvurg)
1674 				goto got_oob;
1675 			byte_count++;
1676 			if (c == '\n')
1677 				bare_lfs++;
1678 			while (c == '\r') {
1679 				if (ferror(outstr))
1680 					goto data_err;
1681 				if ((c = getc(instr)) != '\n') {
1682 					(void) putc ('\r', outstr);
1683 					if (c == '\0' || c == EOF)
1684 						goto contin2;
1685 				}
1686 			}
1687 			(void) putc(c, outstr);
1688 	contin2:	;
1689 		}
1690 		fflush(outstr);
1691 		if (ferror(instr))
1692 			goto data_err;
1693 		if (ferror(outstr))
1694 			goto file_err;
1695 		transflag = 0;
1696 		if (bare_lfs) {
1697 			lreply(226,
1698 			    "WARNING! %d bare linefeeds received in ASCII mode",
1699 			    bare_lfs);
1700 			printf("   File may not have transferred correctly.\r\n");
1701 		}
1702 		return (0);
1703 	default:
1704 		reply(550, "Unimplemented TYPE %d in receive_data", type);
1705 		transflag = 0;
1706 		return (-1);
1707 	}
1708 
1709 data_err:
1710 	transflag = 0;
1711 	reply(426, "Data Connection");
1712 	return (-1);
1713 
1714 file_err:
1715 	transflag = 0;
1716 	reply(452, "Error writing file");
1717 	return (-1);
1718 
1719 got_oob:
1720 	myoob();
1721 	recvurg = 0;
1722 	transflag = 0;
1723 	return (-1);
1724 }
1725 
1726 void
1727 statfilecmd(char *filename)
1728 {
1729 	FILE *fin;
1730 	int c;
1731 	int atstart;
1732 	pid_t pid;
1733 	fin = ftpd_ls(filename, &pid);
1734 	if (fin == NULL) {
1735 		reply(451, "Local resource failure");
1736 		return;
1737 	}
1738 	lreply(211, "status of %s:", filename);
1739 	atstart = 1;
1740 	while ((c = getc(fin)) != EOF) {
1741 		if (c == '\n') {
1742 			if (ferror(stdout)){
1743 				perror_reply(421, "control connection");
1744 				(void) ftpd_pclose(fin, pid);
1745 				dologout(1);
1746 				/* NOTREACHED */
1747 			}
1748 			if (ferror(fin)) {
1749 				perror_reply(551, filename);
1750 				(void) ftpd_pclose(fin, pid);
1751 				return;
1752 			}
1753 			(void) putc('\r', stdout);
1754 		}
1755 		if (atstart && isdigit(c))
1756 			(void) putc(' ', stdout);
1757 		(void) putc(c, stdout);
1758 		atstart = (c == '\n');
1759 	}
1760 	(void) ftpd_pclose(fin, pid);
1761 	reply(211, "End of Status");
1762 }
1763 
1764 void
1765 statcmd(void)
1766 {
1767 	union sockunion *su;
1768 	u_char *a, *p;
1769 	char hbuf[HOST_NAME_MAX+1];
1770 	int ispassive;
1771 	int error;
1772 
1773 	lreply(211, "%s FTP server status:", hostname);
1774 	error = getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
1775 	    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST);
1776 	printf("     Connected to %s", remotehost);
1777 	if (error == 0 && strcmp(remotehost, hbuf) != 0)
1778 		printf(" (%s)", hbuf);
1779 	printf("\r\n");
1780 	if (logged_in) {
1781 		if (guest)
1782 			printf("     Logged in anonymously\r\n");
1783 		else
1784 			printf("     Logged in as %s\r\n", pw->pw_name);
1785 	} else if (askpasswd)
1786 		printf("     Waiting for password\r\n");
1787 	else
1788 		printf("     Waiting for user name\r\n");
1789 	printf("     TYPE: %s", typenames[type]);
1790 	if (type == TYPE_A || type == TYPE_E)
1791 		printf(", FORM: %s", formnames[form]);
1792 	if (type == TYPE_L)
1793 		printf(" 8");
1794 	printf("; STRUcture: %s; transfer MODE: %s\r\n",
1795 	    strunames[stru], modenames[mode]);
1796 	ispassive = 0;
1797 	if (data != -1)
1798 		printf("     Data connection open\r\n");
1799 	else if (pdata != -1) {
1800 		printf("     in Passive mode\r\n");
1801 		su = (union sockunion *)&pasv_addr;
1802 		ispassive++;
1803 		goto printaddr;
1804 	} else if (usedefault == 0) {
1805 		size_t alen, i;
1806 		int af;
1807 
1808 		su = (union sockunion *)&data_dest;
1809 printaddr:
1810 		/* PASV/PORT */
1811 		if (su->su_family == AF_INET) {
1812 			if (ispassive)
1813 				printf("211- PASV ");
1814 			else
1815 				printf("211- PORT ");
1816 			a = (u_char *)&su->su_sin.sin_addr;
1817 			p = (u_char *)&su->su_sin.sin_port;
1818 			printf("(%u,%u,%u,%u,%u,%u)\r\n",
1819 			    a[0], a[1], a[2], a[3],
1820 			    p[0], p[1]);
1821 		}
1822 
1823 		/* LPSV/LPRT */
1824 		alen = 0;
1825 		switch (su->su_family) {
1826 		case AF_INET:
1827 			a = (u_char *)&su->su_sin.sin_addr;
1828 			p = (u_char *)&su->su_sin.sin_port;
1829 			alen = sizeof(su->su_sin.sin_addr);
1830 			af = 4;
1831 			break;
1832 		case AF_INET6:
1833 			a = (u_char *)&su->su_sin6.sin6_addr;
1834 			p = (u_char *)&su->su_sin6.sin6_port;
1835 			alen = sizeof(su->su_sin6.sin6_addr);
1836 			af = 6;
1837 			break;
1838 		default:
1839 			af = 0;
1840 			break;
1841 		}
1842 		if (af) {
1843 			if (ispassive)
1844 				printf("211- LPSV ");
1845 			else
1846 				printf("211- LPRT ");
1847 			printf("(%u,%llu", af, (unsigned long long)alen);
1848 			for (i = 0; i < alen; i++)
1849 				printf(",%u", a[i]);
1850 			printf(",%u,%u,%u)\r\n", 2, p[0], p[1]);
1851 		}
1852 
1853 		/* EPRT/EPSV */
1854 		switch (su->su_family) {
1855 		case AF_INET:
1856 			af = 1;
1857 			break;
1858 		case AF_INET6:
1859 			af = 2;
1860 			break;
1861 		default:
1862 			af = 0;
1863 			break;
1864 		}
1865 		if (af) {
1866 			char pbuf[10];
1867 			union sockunion tmp = *su;
1868 
1869 			if (tmp.su_family == AF_INET6)
1870 				tmp.su_sin6.sin6_scope_id = 0;
1871 			if (getnameinfo((struct sockaddr *)&tmp, tmp.su_len,
1872 			    hbuf, sizeof(hbuf), pbuf, sizeof(pbuf),
1873 			    NI_NUMERICHOST | NI_NUMERICSERV) == 0) {
1874 				if (ispassive)
1875 					printf("211- EPSV ");
1876 				else
1877 					printf("211- EPRT ");
1878 				printf("(|%u|%s|%s|)\r\n",
1879 				    af, hbuf, pbuf);
1880 			}
1881 		}
1882 	} else
1883 		printf("     No data connection\r\n");
1884 	reply(211, "End of status");
1885 }
1886 
1887 void
1888 fatal(char *s)
1889 {
1890 
1891 	reply(451, "Error in server: %s", s);
1892 	reply(221, "Closing connection due to server error.");
1893 	dologout(0);
1894 	/* NOTREACHED */
1895 }
1896 
1897 void
1898 reply(int n, const char *fmt, ...)
1899 {
1900 	char *buf, *p, *next;
1901 	int rval;
1902 	va_list ap;
1903 
1904 	va_start(ap, fmt);
1905 	rval = vasprintf(&buf, fmt, ap);
1906 	va_end(ap);
1907 	if (rval == -1 || buf == NULL) {
1908 		printf("421 Local resource failure: malloc\r\n");
1909 		fflush(stdout);
1910 		dologout(1);
1911 	}
1912 	next = buf;
1913 	while ((p = strsep(&next, "\n\r"))) {
1914 		printf("%d%s %s\r\n", n, (next != NULL) ? "-" : "", p);
1915 		if (debug)
1916 			syslog(LOG_DEBUG, "<--- %d%s %s", n,
1917 			    (next != NULL) ? "-" : "", p);
1918 	}
1919 	(void)fflush(stdout);
1920 	free(buf);
1921 }
1922 
1923 
1924 void
1925 reply_r(int n, const char *fmt, ...)
1926 {
1927 	char *p, *next;
1928 	char msg[BUFSIZ];
1929 	char buf[BUFSIZ];
1930 	va_list ap;
1931 	struct syslog_data sdata = SYSLOG_DATA_INIT;
1932 
1933 	sdata.log_fac = LOG_FTP;
1934 	va_start(ap, fmt);
1935 	vsnprintf(msg, sizeof(msg), fmt, ap);
1936 	va_end(ap);
1937 
1938 	next = msg;
1939 
1940 	while ((p = strsep(&next, "\n\r"))) {
1941 		snprintf(buf, sizeof(buf), "%d%s %s\r\n", n,
1942 		    (next != NULL) ? "-" : "", p);
1943 		write(STDOUT_FILENO, buf, strlen(buf));
1944 		if (debug) {
1945 			buf[strlen(buf) - 2] = '\0';
1946 			syslog_r(LOG_DEBUG, &sdata, "<--- %s", buf);
1947 		}
1948 	}
1949 }
1950 
1951 void
1952 lreply(int n, const char *fmt, ...)
1953 {
1954 	va_list ap;
1955 
1956 	va_start(ap, fmt);
1957 	(void)printf("%d- ", n);
1958 	(void)vprintf(fmt, ap);
1959 	va_end(ap);
1960 	(void)printf("\r\n");
1961 	(void)fflush(stdout);
1962 	if (debug) {
1963 		va_start(ap, fmt);
1964 		syslog(LOG_DEBUG, "<--- %d- ", n);
1965 		vsyslog(LOG_DEBUG, fmt, ap);
1966 		va_end(ap);
1967 	}
1968 }
1969 
1970 static void
1971 ack(char *s)
1972 {
1973 
1974 	reply(250, "%s command successful.", s);
1975 }
1976 
1977 void
1978 nack(char *s)
1979 {
1980 
1981 	reply(502, "%s command not implemented.", s);
1982 }
1983 
1984 /* ARGSUSED */
1985 void
1986 yyerror(char *s)
1987 {
1988 	cbuf[strcspn(cbuf, "\n")] = '\0';
1989 	reply(500, "'%s': command not understood.", cbuf);
1990 }
1991 
1992 void
1993 delete(char *name)
1994 {
1995 	struct stat st;
1996 
1997 	LOGCMD("delete", name);
1998 	if (stat(name, &st) == -1) {
1999 		perror_reply(550, name);
2000 		return;
2001 	}
2002 	if ((st.st_mode&S_IFMT) == S_IFDIR) {
2003 		if (rmdir(name) == -1) {
2004 			perror_reply(550, name);
2005 			return;
2006 		}
2007 		goto done;
2008 	}
2009 	if (unlink(name) == -1) {
2010 		perror_reply(550, name);
2011 		return;
2012 	}
2013 done:
2014 	ack("DELE");
2015 }
2016 
2017 void
2018 cwd(char *path)
2019 {
2020 	FILE *message;
2021 
2022 	if (chdir(path) == -1)
2023 		perror_reply(550, path);
2024 	else {
2025 		if ((message = fopen(_PATH_CWDMESG, "r")) != NULL) {
2026 			char line[LINE_MAX];
2027 
2028 			while (fgets(line, sizeof(line), message) != NULL) {
2029 				line[strcspn(line, "\n")] = '\0';
2030 				lreply(250, "%s", line);
2031 			}
2032 			(void) fflush(stdout);
2033 			(void) fclose(message);
2034 		}
2035 		ack("CWD");
2036 	}
2037 }
2038 
2039 void
2040 replydirname(const char *name, const char *message)
2041 {
2042 	char *p, *ep;
2043 	char npath[PATH_MAX * 2];
2044 
2045 	p = npath;
2046 	ep = &npath[sizeof(npath) - 1];
2047 	while (*name) {
2048 		if (*name == '"') {
2049 			if (ep - p < 2)
2050 				break;
2051 			*p++ = *name++;
2052 			*p++ = '"';
2053 		} else {
2054 			if (ep - p < 1)
2055 				break;
2056 			*p++ = *name++;
2057 		}
2058 	}
2059 	*p = '\0';
2060 	reply(257, "\"%s\" %s", npath, message);
2061 }
2062 
2063 void
2064 makedir(char *name)
2065 {
2066 
2067 	LOGCMD("mkdir", name);
2068 	if (mkdir(name, 0777) == -1)
2069 		perror_reply(550, name);
2070 	else
2071 		replydirname(name, "directory created.");
2072 }
2073 
2074 void
2075 removedir(char *name)
2076 {
2077 
2078 	LOGCMD("rmdir", name);
2079 	if (rmdir(name) == -1)
2080 		perror_reply(550, name);
2081 	else
2082 		ack("RMD");
2083 }
2084 
2085 void
2086 pwd(void)
2087 {
2088 	char path[PATH_MAX];
2089 
2090 	if (getcwd(path, sizeof(path)) == NULL)
2091 		perror_reply(550, "Can't get current directory");
2092 	else
2093 		replydirname(path, "is current directory.");
2094 }
2095 
2096 char *
2097 renamefrom(char *name)
2098 {
2099 	struct stat st;
2100 
2101 	if (stat(name, &st) == -1) {
2102 		perror_reply(550, name);
2103 		return (NULL);
2104 	}
2105 	reply(350, "File exists, ready for destination name");
2106 	return (name);
2107 }
2108 
2109 void
2110 renamecmd(char *from, char *to)
2111 {
2112 
2113 	LOGCMD2("rename", from, to);
2114 	if (rename(from, to) == -1)
2115 		perror_reply(550, "rename");
2116 	else
2117 		ack("RNTO");
2118 }
2119 
2120 static void
2121 dolog(struct sockaddr *sa)
2122 {
2123 	char hbuf[sizeof(remotehost)];
2124 
2125 	if (getnameinfo(sa, sa->sa_len, hbuf, sizeof(hbuf), NULL, 0, 0) == 0)
2126 		(void) strlcpy(remotehost, hbuf, sizeof(remotehost));
2127 	else
2128 		(void) strlcpy(remotehost, "unknown", sizeof(remotehost));
2129 
2130 	snprintf(proctitle, sizeof(proctitle), "%s: connected", remotehost);
2131 	setproctitle("%s", proctitle);
2132 
2133 	if (logging) {
2134 		int error;
2135 		error = getnameinfo(sa, sa->sa_len, hbuf, sizeof(hbuf),
2136 		    NULL, 0, NI_NUMERICHOST);
2137 		syslog(LOG_INFO, "connection from %s [%s]", remotehost,
2138 		    error ? gai_strerror(error) : hbuf);
2139 	}
2140 }
2141 
2142 /*
2143  * Record logout in wtmp file and exit with supplied status.
2144  * NOTE: because this is called from signal handlers it cannot
2145  *       use stdio (or call other functions that use stdio).
2146  */
2147 void
2148 dologout(int status)
2149 {
2150 
2151 	transflag = 0;
2152 
2153 	if (logged_in) {
2154 		sigprocmask(SIG_BLOCK, &allsigs, NULL);
2155 		if (!nowtmp)
2156 			ftpdlogwtmp(ttyline, "", "");
2157 		if (doutmp)
2158 			ftpd_logout(utmp.ut_line);
2159 	}
2160 	/* beware of flushing buffers after a SIGPIPE */
2161 	_exit(status);
2162 }
2163 
2164 /*ARGSUSED*/
2165 static void
2166 sigurg(int signo)
2167 {
2168 
2169 	recvurg = 1;
2170 }
2171 
2172 static void
2173 myoob(void)
2174 {
2175 	char *cp;
2176 	int ret;
2177 
2178 	/* only process if transfer occurring */
2179 	if (!transflag)
2180 		return;
2181 	cp = tmpline;
2182 	ret = get_line(cp, sizeof(tmpline)-1, stdin);
2183 	if (ret == -1) {
2184 		reply(221, "You could at least say goodbye.");
2185 		dologout(0);
2186 	} else if (ret == -2) {
2187 		/* Ignore truncated command */
2188 		return;
2189 	}
2190 	upper(cp);
2191 	if (strcmp(cp, "ABOR\r\n") == 0) {
2192 		tmpline[0] = '\0';
2193 		reply(426, "Transfer aborted. Data connection closed.");
2194 		reply(226, "Abort successful");
2195 	}
2196 	if (strcmp(cp, "STAT\r\n") == 0) {
2197 		tmpline[0] = '\0';
2198 		if (file_size != -1)
2199 			reply(213, "Status: %lld of %lld bytes transferred",
2200 			    (long long)byte_count, (long long)file_size);
2201 		else
2202 			reply(213, "Status: %lld bytes transferred",
2203 			    (long long)byte_count);
2204 	}
2205 }
2206 
2207 /*
2208  * Note: a response of 425 is not mentioned as a possible response to
2209  *	the PASV command in RFC959. However, it has been blessed as
2210  *	a legitimate response by Jon Postel in a telephone conversation
2211  *	with Rick Adams on 25 Jan 89.
2212  */
2213 void
2214 passive(void)
2215 {
2216 	socklen_t len;
2217 	int on = 1;
2218 	u_char *p, *a;
2219 
2220 	if (pw == NULL) {
2221 		reply(530, "Please login with USER and PASS");
2222 		return;
2223 	}
2224 	if (pdata >= 0)
2225 		close(pdata);
2226 	/*
2227 	 * XXX
2228 	 * At this point, it would be nice to have an algorithm that
2229 	 * inserted a growing delay in an attack scenario.  Such a thing
2230 	 * would look like continual passive sockets being opened, but
2231 	 * nothing serious being done with them.  They're not used to
2232 	 * move data; the entire attempt is just to use tcp FIN_WAIT
2233 	 * resources.
2234 	 */
2235 	pdata = socket(AF_INET, SOCK_STREAM, 0);
2236 	if (pdata == -1) {
2237 		perror_reply(425, "Can't open passive connection");
2238 		return;
2239 	}
2240 
2241 	if (setsockopt(pdata, SOL_SOCKET, SO_KEEPALIVE,
2242 	    &on, sizeof(on)) == -1)
2243 		goto pasv_error;
2244 
2245 	on = IP_PORTRANGE_HIGH;
2246 	if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2247 	    &on, sizeof(on)) == -1)
2248 		goto pasv_error;
2249 
2250 	pasv_addr = ctrl_addr;
2251 	pasv_addr.su_sin.sin_port = 0;
2252 	if (bind(pdata, (struct sockaddr *)&pasv_addr,
2253 	    pasv_addr.su_len) == -1)
2254 		goto pasv_error;
2255 
2256 	len = sizeof(pasv_addr);
2257 	if (getsockname(pdata, (struct sockaddr *)&pasv_addr, &len) == -1)
2258 		goto pasv_error;
2259 	if (listen(pdata, 1) == -1)
2260 		goto pasv_error;
2261 	a = (u_char *)&pasv_addr.su_sin.sin_addr;
2262 	p = (u_char *)&pasv_addr.su_sin.sin_port;
2263 
2264 	reply(227, "Entering Passive Mode (%u,%u,%u,%u,%u,%u)", a[0],
2265 	    a[1], a[2], a[3], p[0], p[1]);
2266 	return;
2267 
2268 pasv_error:
2269 	perror_reply(425, "Can't open passive connection");
2270 	(void) close(pdata);
2271 	pdata = -1;
2272 	return;
2273 }
2274 
2275 int
2276 epsvproto2af(int proto)
2277 {
2278 
2279 	switch (proto) {
2280 	case 1:	return AF_INET;
2281 	case 2:	return AF_INET6;
2282 	default: return -1;
2283 	}
2284 }
2285 
2286 int
2287 af2epsvproto(int af)
2288 {
2289 
2290 	switch (af) {
2291 	case AF_INET:	return 1;
2292 	case AF_INET6:	return 2;
2293 	default:	return -1;
2294 	}
2295 }
2296 
2297 /*
2298  * 228 Entering Long Passive Mode (af, hal, h1, h2, h3,..., pal, p1, p2...)
2299  * 229 Entering Extended Passive Mode (|||port|)
2300  */
2301 void
2302 long_passive(char *cmd, int pf)
2303 {
2304 	socklen_t len;
2305 	int on = 1;
2306 	u_char *p, *a;
2307 
2308 	if (!logged_in) {
2309 		syslog(LOG_NOTICE, "long passive but not logged in");
2310 		reply(503, "Login with USER first.");
2311 		return;
2312 	}
2313 
2314 	if (pf != PF_UNSPEC && ctrl_addr.su_family != pf) {
2315 		/*
2316 		 * XXX
2317 		 * only EPRT/EPSV ready clients will understand this
2318 		 */
2319 		if (strcmp(cmd, "EPSV") != 0)
2320 			reply(501, "Network protocol mismatch"); /*XXX*/
2321 		else
2322 			epsv_protounsupp("Network protocol mismatch");
2323 
2324 		return;
2325 	}
2326 
2327 	if (pdata >= 0)
2328 		close(pdata);
2329 	/*
2330 	 * XXX
2331 	 * At this point, it would be nice to have an algorithm that
2332 	 * inserted a growing delay in an attack scenario.  Such a thing
2333 	 * would look like continual passive sockets being opened, but
2334 	 * nothing serious being done with them.  They not used to move
2335 	 * data; the entire attempt is just to use tcp FIN_WAIT
2336 	 * resources.
2337 	 */
2338 	pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2339 	if (pdata == -1) {
2340 		perror_reply(425, "Can't open passive connection");
2341 		return;
2342 	}
2343 
2344 	if (setsockopt(pdata, SOL_SOCKET, SO_KEEPALIVE,
2345 	    &on, sizeof(on)) == -1)
2346 		goto pasv_error;
2347 
2348 	switch (ctrl_addr.su_family) {
2349 	case AF_INET:
2350 		on = IP_PORTRANGE_HIGH;
2351 		if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2352 		    &on, sizeof(on)) == -1)
2353 			goto pasv_error;
2354 		break;
2355 	case AF_INET6:
2356 		on = IPV6_PORTRANGE_HIGH;
2357 		if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2358 		    &on, sizeof(on)) == -1)
2359 			goto pasv_error;
2360 		break;
2361 	}
2362 
2363 	pasv_addr = ctrl_addr;
2364 	pasv_addr.su_port = 0;
2365 	if (bind(pdata, (struct sockaddr *)&pasv_addr, pasv_addr.su_len) == -1)
2366 		goto pasv_error;
2367 	len = pasv_addr.su_len;
2368 	if (getsockname(pdata, (struct sockaddr *)&pasv_addr, &len) == -1)
2369 		goto pasv_error;
2370 	if (listen(pdata, 1) == -1)
2371 		goto pasv_error;
2372 	p = (u_char *)&pasv_addr.su_port;
2373 
2374 	if (strcmp(cmd, "LPSV") == 0) {
2375 		switch (pasv_addr.su_family) {
2376 		case AF_INET:
2377 			a = (u_char *)&pasv_addr.su_sin.sin_addr;
2378 			reply(228,
2379 			    "Entering Long Passive Mode (%u,%u,%u,%u,%u,%u,%u,%u,%u)",
2380 			    4, 4, a[0], a[1], a[2], a[3], 2, p[0], p[1]);
2381 			return;
2382 		case AF_INET6:
2383 			a = (u_char *)&pasv_addr.su_sin6.sin6_addr;
2384 			reply(228,
2385 			    "Entering Long Passive Mode (%u,%u,%u,%u,%u,%u,"
2386 			    "%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u)",
2387 				6, 16, a[0], a[1], a[2], a[3], a[4],
2388 				a[5], a[6], a[7], a[8], a[9], a[10],
2389 				a[11], a[12], a[13], a[14], a[15],
2390 				2, p[0], p[1]);
2391 			return;
2392 		}
2393 	} else if (strcmp(cmd, "EPSV") == 0) {
2394 		switch (pasv_addr.su_family) {
2395 		case AF_INET:
2396 		case AF_INET6:
2397 			reply(229, "Entering Extended Passive Mode (|||%u|)",
2398 			    ntohs(pasv_addr.su_port));
2399 			return;
2400 		}
2401 	} else {
2402 		/* more proper error code? */
2403 	}
2404 
2405   pasv_error:
2406 	perror_reply(425, "Can't open passive connection");
2407 	(void) close(pdata);
2408 	pdata = -1;
2409 	return;
2410 }
2411 
2412 /*
2413  * EPRT |proto|addr|port|
2414  */
2415 int
2416 extended_port(const char *arg)
2417 {
2418 	char *tmp = NULL;
2419 	char *result[3];
2420 	char *p, *q;
2421 	char delim;
2422 	struct addrinfo hints;
2423 	struct addrinfo *res = NULL;
2424 	int i;
2425 	unsigned long proto;
2426 
2427 	if (epsvall) {
2428 		reply(501, "EPRT disallowed after EPSV ALL");
2429 		return -1;
2430 	}
2431 
2432 	usedefault = 0;
2433 	if (pdata >= 0) {
2434 		(void) close(pdata);
2435 		pdata = -1;
2436 	}
2437 
2438 	tmp = strdup(arg);
2439 	if (!tmp) {
2440 		fatal("not enough core.");
2441 		/*NOTREACHED*/
2442 	}
2443 	p = tmp;
2444 	delim = p[0];
2445 	p++;
2446 	memset(result, 0, sizeof(result));
2447 	for (i = 0; i < 3; i++) {
2448 		q = strchr(p, delim);
2449 		if (!q || *q != delim)
2450 			goto parsefail;
2451 		*q++ = '\0';
2452 		result[i] = p;
2453 		p = q;
2454 	}
2455 
2456 	/* some more sanity check */
2457 	p = NULL;
2458 	(void)strtoul(result[2], &p, 10);
2459 	if (!*result[2] || *p)
2460 		goto protounsupp;
2461 	p = NULL;
2462 	proto = strtoul(result[0], &p, 10);
2463 	if (!*result[0] || *p)
2464 		goto protounsupp;
2465 
2466 	memset(&hints, 0, sizeof(hints));
2467 	hints.ai_family = epsvproto2af((int)proto);
2468 	if (hints.ai_family < 0)
2469 		goto protounsupp;
2470 	hints.ai_socktype = SOCK_STREAM;
2471 	hints.ai_flags = AI_NUMERICHOST;	/*no DNS*/
2472 	if (getaddrinfo(result[1], result[2], &hints, &res))
2473 		goto parsefail;
2474 	if (res->ai_next)
2475 		goto parsefail;
2476 	if (sizeof(data_dest) < res->ai_addrlen)
2477 		goto parsefail;
2478 	memcpy(&data_dest, res->ai_addr, res->ai_addrlen);
2479 	if (his_addr.su_family == AF_INET6 &&
2480 	    data_dest.su_family == AF_INET6) {
2481 		/* XXX more sanity checks! */
2482 		data_dest.su_sin6.sin6_scope_id =
2483 		    his_addr.su_sin6.sin6_scope_id;
2484 	}
2485 	if (pdata >= 0) {
2486 		(void) close(pdata);
2487 		pdata = -1;
2488 	}
2489 	reply(200, "EPRT command successful.");
2490 
2491 	free(tmp);
2492 	if (res)
2493 		freeaddrinfo(res);
2494 	return 0;
2495 
2496 parsefail:
2497 	reply(500, "Invalid argument, rejected.");
2498 	usedefault = 1;
2499 	free(tmp);
2500 	if (res)
2501 		freeaddrinfo(res);
2502 	return -1;
2503 
2504 protounsupp:
2505 	epsv_protounsupp("Protocol not supported");
2506 	usedefault = 1;
2507 	free(tmp);
2508 	if (res)
2509 		freeaddrinfo(res);
2510 	return -1;
2511 }
2512 
2513 /*
2514  * 522 Protocol not supported (proto,...)
2515  * as we assume address family for control and data connections are the same,
2516  * we do not return the list of address families we support - instead, we
2517  * return the address family of the control connection.
2518  */
2519 void
2520 epsv_protounsupp(const char *message)
2521 {
2522 	int proto;
2523 
2524 	proto = af2epsvproto(ctrl_addr.su_family);
2525 	if (proto < 0)
2526 		reply(501, "%s", message);	/*XXX*/
2527 	else
2528 		reply(522, "%s, use (%d)", message, proto);
2529 }
2530 
2531 /*
2532  * Generate unique name for file with basename "local".
2533  * The file named "local" is already known to exist.
2534  * Generates failure reply on error.
2535  */
2536 static int
2537 guniquefd(char *local, char **nam)
2538 {
2539 	static char new[PATH_MAX];
2540 	struct stat st;
2541 	size_t len;
2542 	int count, fd;
2543 	char *cp;
2544 
2545 	cp = strrchr(local, '/');
2546 	if (cp)
2547 		*cp = '\0';
2548 	if (stat(cp ? local : ".", &st) == -1) {
2549 		perror_reply(553, cp ? local : ".");
2550 		return (-1);
2551 	}
2552 	if (cp)
2553 		*cp = '/';
2554 	len = strlcpy(new, local, sizeof(new));
2555 	if (len+2+1 >= sizeof(new)-1)
2556 		return (-1);
2557 	cp = new + len;
2558 	*cp++ = '.';
2559 	for (count = 1; count < 100; count++) {
2560 		(void)snprintf(cp, sizeof(new) - (cp - new), "%d", count);
2561 		fd = open(new, O_RDWR|O_CREAT|O_EXCL, 0666);
2562 		if (fd == -1)
2563 			continue;
2564 		if (nam)
2565 			*nam = new;
2566 		return (fd);
2567 	}
2568 	reply(452, "Unique file name cannot be created.");
2569 	return (-1);
2570 }
2571 
2572 /*
2573  * Format and send reply containing system error number.
2574  */
2575 void
2576 perror_reply(int code, char *string)
2577 {
2578 
2579 	reply(code, "%s: %s.", string, strerror(errno));
2580 }
2581 
2582 static char *onefile[] = {
2583 	"",
2584 	0
2585 };
2586 
2587 void
2588 send_file_list(char *whichf)
2589 {
2590 	struct stat st;
2591 	DIR *dirp = NULL;
2592 	struct dirent *dir;
2593 	FILE *dout = NULL;
2594 	char **dirlist;
2595 	char *dirname;
2596 	int simple = 0;
2597 	volatile int freeglob = 0;
2598 	glob_t gl;
2599 	size_t prefixlen;
2600 
2601 	if (strpbrk(whichf, "~{[*?") != NULL) {
2602 		memset(&gl, 0, sizeof(gl));
2603 		freeglob = 1;
2604 		if (glob(whichf,
2605 		    GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE|GLOB_LIMIT,
2606 		    0, &gl)) {
2607 			reply(550, "not found");
2608 			goto out;
2609 		} else if (gl.gl_pathc == 0) {
2610 			errno = ENOENT;
2611 			perror_reply(550, whichf);
2612 			goto out;
2613 		}
2614 		dirlist = gl.gl_pathv;
2615 	} else {
2616 		onefile[0] = whichf;
2617 		dirlist = onefile;
2618 		simple = 1;
2619 	}
2620 
2621 	while ((dirname = *dirlist++)) {
2622 		if (stat(dirname, &st) == -1) {
2623 			/*
2624 			 * If user typed "ls -l", etc, and the client
2625 			 * used NLST, do what the user meant.
2626 			 */
2627 			if (dirname[0] == '-' && *dirlist == NULL &&
2628 			    transflag == 0) {
2629 				retrieve(RET_FILE, dirname);
2630 				goto out;
2631 			}
2632 			perror_reply(550, whichf);
2633 			if (dout != NULL) {
2634 				(void) fclose(dout);
2635 				transflag = 0;
2636 				data = -1;
2637 				pdata = -1;
2638 			}
2639 			goto out;
2640 		}
2641 
2642 		if (S_ISREG(st.st_mode)) {
2643 			if (dout == NULL) {
2644 				dout = dataconn("file list", -1, "w");
2645 				if (dout == NULL)
2646 					goto out;
2647 				transflag++;
2648 			}
2649 			fprintf(dout, "%s%s\n", dirname,
2650 				type == TYPE_A ? "\r" : "");
2651 			byte_count += strlen(dirname) + 1;
2652 			continue;
2653 		} else if (!S_ISDIR(st.st_mode))
2654 			continue;
2655 
2656 		if ((dirp = opendir(dirname)) == NULL)
2657 			continue;
2658 
2659 		if (dirname[0] == '.' && dirname[1] == '\0')
2660 			prefixlen = 0;
2661 		else
2662 			prefixlen = strlen(dirname) + 1;
2663 		while ((dir = readdir(dirp)) != NULL) {
2664 			if (recvurg) {
2665 				myoob();
2666 				recvurg = 0;
2667 				transflag = 0;
2668 				goto out;
2669 			}
2670 
2671 			if (dir->d_name[0] == '.' && dir->d_namlen == 1)
2672 				continue;
2673 			if (dir->d_name[0] == '.' && dir->d_name[1] == '.' &&
2674 			    dir->d_namlen == 2)
2675 				continue;
2676 
2677 			/*
2678 			 * We have to do a stat to insure it's
2679 			 * not a directory or special file.
2680 			 */
2681 			if (simple ||
2682 			    (fstatat(dirfd(dirp), dir->d_name, &st, 0) == 0 &&
2683 			    S_ISREG(st.st_mode))) {
2684 				if (dout == NULL) {
2685 					dout = dataconn("file list", -1, "w");
2686 					if (dout == NULL)
2687 						goto out;
2688 					transflag++;
2689 				}
2690 
2691 				if (prefixlen) {
2692 					fprintf(dout, "%s/", dirname);
2693 					byte_count += prefixlen;
2694 				}
2695 				fprintf(dout, "%s%s\n", dir->d_name,
2696 				    type == TYPE_A ? "\r" : "");
2697 				byte_count += dir->d_namlen + 1;
2698 			}
2699 		}
2700 		(void) closedir(dirp);
2701 	}
2702 
2703 	if (dout == NULL)
2704 		reply(550, "No files found.");
2705 	else if (ferror(dout) != 0)
2706 		perror_reply(550, "Data connection");
2707 	else
2708 		reply(226, "Transfer complete.");
2709 
2710 	transflag = 0;
2711 	if (dout != NULL)
2712 		(void) fclose(dout);
2713 	else {
2714 		if (pdata >= 0)
2715 			close(pdata);
2716 	}
2717 	data = -1;
2718 	pdata = -1;
2719 out:
2720 	if (freeglob) {
2721 		freeglob = 0;
2722 		globfree(&gl);
2723 	}
2724 }
2725 
2726 /*ARGSUSED*/
2727 static void
2728 reapchild(int signo)
2729 {
2730 	int save_errno = errno;
2731 	int rval;
2732 
2733 	do {
2734 		rval = waitpid(-1, NULL, WNOHANG);
2735 	} while (rval > 0 || (rval == -1 && errno == EINTR));
2736 	errno = save_errno;
2737 }
2738 
2739 void
2740 logxfer(char *name, off_t size, time_t start)
2741 {
2742 	char buf[400 + (HOST_NAME_MAX+1)*4 + PATH_MAX*4];
2743 	char dir[PATH_MAX], path[PATH_MAX], rpath[PATH_MAX];
2744 	char vremotehost[(HOST_NAME_MAX+1)*4], vpath[PATH_MAX*4];
2745 	char *vpw;
2746 	time_t now;
2747 	int len;
2748 
2749 	if ((statfd >= 0) && (getcwd(dir, sizeof(dir)) != NULL)) {
2750 		time(&now);
2751 
2752 		vpw = malloc(strlen(guest ? guestpw : pw->pw_name) * 4 + 1);
2753 		if (vpw == NULL)
2754 			return;
2755 
2756 		snprintf(path, sizeof(path), "%s/%s", dir, name);
2757 		if (realpath(path, rpath) == NULL)
2758 			strlcpy(rpath, path, sizeof(rpath));
2759 		strvis(vpath, rpath, VIS_SAFE|VIS_NOSLASH);
2760 
2761 		strvis(vremotehost, remotehost, VIS_SAFE|VIS_NOSLASH);
2762 		strvis(vpw, guest? guestpw : pw->pw_name, VIS_SAFE|VIS_NOSLASH);
2763 
2764 		len = snprintf(buf, sizeof(buf),
2765 		    "%.24s %lld %s %lld %s %c %s %c %c %s ftp %d %s %s\n",
2766 		    ctime(&now), (long long)(now - start + (now == start)),
2767 		    vremotehost, (long long)size, vpath,
2768 		    ((type == TYPE_A) ? 'a' : 'b'), "*" /* none yet */,
2769 		    'o', ((guest) ? 'a' : 'r'),
2770 		    vpw, 0 /* none yet */,
2771 		    ((guest) ? "*" : pw->pw_name), dhostname);
2772 		free(vpw);
2773 
2774 		if (len < 0 || len >= sizeof(buf)) {
2775 			if ((len = strlen(buf)) == 0)
2776 				return;		/* should not happen */
2777 			buf[len - 1] = '\n';
2778 		}
2779 		write(statfd, buf, len);
2780 	}
2781 }
2782 
2783 void
2784 set_slave_signals(void)
2785 {
2786 	struct sigaction sa;
2787 
2788 	sigemptyset(&sa.sa_mask);
2789 	sa.sa_flags = SA_RESTART;
2790 
2791 	sa.sa_handler = SIG_DFL;
2792 	(void) sigaction(SIGCHLD, &sa, NULL);
2793 
2794 	sa.sa_handler = sigurg;
2795 	sa.sa_flags = 0;		/* don't restart syscalls for SIGURG */
2796 	(void) sigaction(SIGURG, &sa, NULL);
2797 
2798 	sigfillset(&sa.sa_mask);	/* block all signals in handler */
2799 	sa.sa_flags = SA_RESTART;
2800 	sa.sa_handler = sigquit;
2801 	(void) sigaction(SIGHUP, &sa, NULL);
2802 	(void) sigaction(SIGINT, &sa, NULL);
2803 	(void) sigaction(SIGQUIT, &sa, NULL);
2804 	(void) sigaction(SIGTERM, &sa, NULL);
2805 
2806 	sa.sa_handler = lostconn;
2807 	(void) sigaction(SIGPIPE, &sa, NULL);
2808 
2809 	sa.sa_handler = toolong;
2810 	(void) sigaction(SIGALRM, &sa, NULL);
2811 
2812 	if (fcntl(fileno(stdin), F_SETOWN, getpid()) == -1)
2813 		syslog(LOG_ERR, "fcntl F_SETOWN: %m");
2814 }
2815 
2816 /*
2817  * Allocate space and return a copy of the specified dir.
2818  * If 'dir' begins with a tilde (~), expand it.
2819  */
2820 char *
2821 copy_dir(char *dir, struct passwd *pw)
2822 {
2823 	char *cp;
2824 	char *newdir;
2825 	char *user = NULL;
2826 
2827 	/* Nothing to expand */
2828 	if (dir[0] != '~')
2829 		return (strdup(dir));
2830 
2831 	/* "dir" is of form ~user/some/dir, lookup user. */
2832 	if (dir[1] != '/' && dir[1] != '\0') {
2833 		if ((cp = strchr(dir + 1, '/')) == NULL)
2834 			cp = dir + strlen(dir);
2835 		if ((user = malloc((size_t)(cp - dir))) == NULL)
2836 			return (NULL);
2837 		strlcpy(user, dir + 1, (size_t)(cp - dir));
2838 
2839 		/* Only do lookup if it is a different user. */
2840 		if (strcmp(user, pw->pw_name) != 0) {
2841 			if ((pw = getpwnam(user)) == NULL) {
2842 				/* No such user, interpret literally */
2843 				free(user);
2844 				return(strdup(dir));
2845 			}
2846 		}
2847 		free(user);
2848 	}
2849 
2850 	/*
2851 	 * If there is no directory separator (/) then it is just pw_dir.
2852 	 * Otherwise, replace ~foo with pw_dir.
2853 	 */
2854 	if ((cp = strchr(dir + 1, '/')) == NULL) {
2855 		newdir = strdup(pw->pw_dir);
2856 	} else {
2857 		if (asprintf(&newdir, "%s%s", pw->pw_dir, cp) == -1)
2858 			return (NULL);
2859 	}
2860 
2861 	return(newdir);
2862 }
2863