xref: /dragonfly/libexec/ftpd/ftpd.c (revision 5868d2b9)
1 /*
2  * Copyright (c) 1985, 1988, 1990, 1992, 1993, 1994
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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * @(#)ftpd.c	8.4 (Berkeley) 4/16/94
34  * $FreeBSD: src/libexec/ftpd/ftpd.c,v 1.213 2008/12/23 01:23:09 cperciva Exp $
35  */
36 
37 /*
38  * FTP server.
39  */
40 #include <sys/param.h>
41 #include <sys/ioctl.h>
42 #include <sys/mman.h>
43 #include <sys/socket.h>
44 #include <sys/stat.h>
45 #include <sys/time.h>
46 #include <sys/wait.h>
47 
48 #include <netinet/in.h>
49 #include <netinet/in_systm.h>
50 #include <netinet/ip.h>
51 #include <netinet/tcp.h>
52 
53 #define	FTP_NAMES
54 #include <arpa/ftp.h>
55 #include <arpa/inet.h>
56 #include <arpa/telnet.h>
57 
58 #include <ctype.h>
59 #include <dirent.h>
60 #include <err.h>
61 #include <errno.h>
62 #include <fcntl.h>
63 #include <glob.h>
64 #include <limits.h>
65 #include <netdb.h>
66 #include <pwd.h>
67 #include <grp.h>
68 #include <opie.h>
69 #include <signal.h>
70 #include <stdint.h>
71 #include <stdio.h>
72 #include <stdlib.h>
73 #include <string.h>
74 #include <syslog.h>
75 #include <time.h>
76 #include <unistd.h>
77 #include <libutil.h>
78 #ifdef	LOGIN_CAP
79 #include <login_cap.h>
80 #endif
81 
82 #ifdef USE_PAM
83 #include <security/pam_appl.h>
84 #endif
85 
86 #include "pathnames.h"
87 #include "extern.h"
88 #include "pidfile.h"
89 
90 #include <stdarg.h>
91 
92 static char version[] = "Version 6.00LS";
93 #undef main
94 
95 extern	off_t restart_point;
96 extern	char cbuf[];
97 
98 union sockunion ctrl_addr;
99 union sockunion data_source;
100 union sockunion data_dest;
101 union sockunion his_addr;
102 union sockunion pasv_addr;
103 
104 int	daemon_mode;
105 int	data;
106 int	dataport;
107 int	hostinfo = 1;	/* print host-specific info in messages */
108 int	logged_in;
109 struct	passwd *pw;
110 char	*homedir;
111 int	ftpdebug;
112 int	timeout = 900;    /* timeout after 15 minutes of inactivity */
113 int	maxtimeout = 7200;/* don't allow idle time to be set beyond 2 hours */
114 int	logging;
115 int	restricted_data_ports = 1;
116 int	paranoid = 1;	  /* be extra careful about security */
117 int	anon_only = 0;    /* Only anonymous ftp allowed */
118 int	assumeutf8 = 0;   /* Assume that server file names are in UTF-8 */
119 int	guest;
120 int	dochroot;
121 char	*chrootdir;
122 int	dowtmp = 1;
123 int	stats;
124 int	statfd = -1;
125 int	type;
126 int	form;
127 int	stru;			/* avoid C keyword */
128 int	mode;
129 int	usedefault = 1;		/* for data transfers */
130 int	pdata = -1;		/* for passive mode */
131 int	readonly = 0;		/* Server is in readonly mode.	*/
132 int	noepsv = 0;		/* EPSV command is disabled.	*/
133 int	noretr = 0;		/* RETR command is disabled.	*/
134 int	noguestretr = 0;	/* RETR command is disabled for anon users. */
135 int	noguestmkd = 0;		/* MKD command is disabled for anon users. */
136 int	noguestmod = 1;		/* anon users may not modify existing files. */
137 
138 off_t	file_size;
139 off_t	byte_count;
140 #if !defined(CMASK) || CMASK == 0
141 #undef CMASK
142 #define CMASK 027
143 #endif
144 int	defumask = CMASK;		/* default umask value */
145 char	tmpline[7];
146 char	*hostname;
147 int	epsvall = 0;
148 
149 #ifdef VIRTUAL_HOSTING
150 char	*ftpuser;
151 
152 static struct ftphost {
153 	struct ftphost	*next;
154 	struct addrinfo *hostinfo;
155 	char		*hostname;
156 	char		*anonuser;
157 	char		*statfile;
158 	char		*welcome;
159 	char		*loginmsg;
160 } *thishost, *firsthost;
161 
162 #endif
163 char	remotehost[NI_MAXHOST];
164 char	*ident = NULL;
165 
166 static char	ttyline[20];
167 char		*tty = ttyline;		/* for klogin */
168 
169 #ifdef USE_PAM
170 static int	auth_pam(struct passwd**, const char*);
171 pam_handle_t	*pamh = NULL;
172 #endif
173 
174 static struct opie	opiedata;
175 static char		opieprompt[OPIE_CHALLENGE_MAX+1];
176 static int		pwok;
177 
178 char	*pid_file = NULL; /* means default location to pidfile(3) */
179 
180 /*
181  * Limit number of pathnames that glob can return.
182  * A limit of 0 indicates the number of pathnames is unlimited.
183  */
184 #define MAXGLOBARGS	16384
185 #
186 
187 /*
188  * Timeout intervals for retrying connections
189  * to hosts that don't accept PORT cmds.  This
190  * is a kludge, but given the problems with TCP...
191  */
192 #define	SWAITMAX	90	/* wait at most 90 seconds */
193 #define	SWAITINT	5	/* interval between retries */
194 
195 int	swaitmax = SWAITMAX;
196 int	swaitint = SWAITINT;
197 
198 #ifdef SETPROCTITLE
199 char	proctitle[LINE_MAX];	/* initial part of title */
200 #endif /* SETPROCTITLE */
201 
202 #define LOGCMD(cmd, file)		logcmd((cmd), (file), NULL, -1)
203 #define LOGCMD2(cmd, file1, file2)	logcmd((cmd), (file1), (file2), -1)
204 #define LOGBYTES(cmd, file, cnt)	logcmd((cmd), (file), NULL, (cnt))
205 
206 static	volatile sig_atomic_t recvurg;
207 static	int transflag;		/* NB: for debugging only */
208 
209 #define STARTXFER	flagxfer(1)
210 #define ENDXFER		flagxfer(0)
211 
212 #define START_UNSAFE	maskurg(1)
213 #define END_UNSAFE	maskurg(0)
214 
215 /* It's OK to put an `else' clause after this macro. */
216 #define CHECKOOB(action)						\
217 	if (recvurg) {							\
218 		recvurg = 0;						\
219 		if (myoob()) {						\
220 			ENDXFER;					\
221 			action;						\
222 		}							\
223 	}
224 
225 #ifdef VIRTUAL_HOSTING
226 static void	 inithosts(int);
227 static void	 selecthost(union sockunion *);
228 #endif
229 static void	 ack(char *);
230 static void	 sigurg(int);
231 static void	 maskurg(int);
232 static void	 flagxfer(int);
233 static int	 myoob(void);
234 static int	 checkuser(char *, char *, int, char **);
235 static FILE	*dataconn(char *, off_t, char *);
236 static void	 dolog(struct sockaddr *);
237 static void	 end_login(void);
238 static FILE	*getdatasock(char *);
239 static int	 guniquefd(char *, char **);
240 static void	 lostconn(int);
241 static void	 sigquit(int);
242 static int	 receive_data(FILE *, FILE *);
243 static int	 send_data(FILE *, FILE *, size_t, off_t, int);
244 static struct passwd *
245 		 sgetpwnam(char *);
246 static char	*sgetsave(char *);
247 static void	 reapchild(int);
248 static void	 appendf(char **, char *, ...) __printflike(2, 3);
249 static void	 logcmd(char *, char *, char *, off_t);
250 static void      logxfer(char *, off_t, time_t);
251 static char	*doublequote(char *);
252 static int	*socksetup(int, char *, const char *);
253 
254 int
255 main(int argc, char *argv[])
256 {
257 	socklen_t addrlen;
258 	int ch, on = 1, tos;
259 	char *cp, line[LINE_MAX];
260 	FILE *fd;
261 	char	*bindname = NULL;
262 	const char *bindport = "ftp";
263 	int	family = AF_UNSPEC;
264 	struct sigaction sa;
265 
266 	tzset();		/* in case no timezone database in ~ftp */
267 	sigemptyset(&sa.sa_mask);
268 	sa.sa_flags = SA_RESTART;
269 
270 	/*
271 	 * Prevent diagnostic messages from appearing on stderr.
272 	 * We run as a daemon or from inetd; in both cases, there's
273 	 * more reason in logging to syslog.
274 	 */
275 	freopen(_PATH_DEVNULL, "w", stderr);
276 	opterr = 0;
277 
278 	/*
279 	 * LOG_NDELAY sets up the logging connection immediately,
280 	 * necessary for anonymous ftp's that chroot and can't do it later.
281 	 */
282 	openlog("ftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
283 
284 	while ((ch = getopt(argc, argv,
285 	                    "468a:AdDEH:hlmMoOp:P:rRSt:T:u:UvW")) != -1) {
286 		switch (ch) {
287 		case '4':
288 			family = (family == AF_INET6) ? AF_UNSPEC : AF_INET;
289 			break;
290 
291 		case '6':
292 			family = (family == AF_INET) ? AF_UNSPEC : AF_INET6;
293 			break;
294 
295 		case '8':
296 			assumeutf8 = 1;
297 			break;
298 
299 		case 'a':
300 			bindname = optarg;
301 			break;
302 
303 		case 'A':
304 			anon_only = 1;
305 			break;
306 
307 		case 'd':
308 			ftpdebug++;
309 			break;
310 
311 		case 'D':
312 			daemon_mode++;
313 			break;
314 
315 		case 'E':
316 			noepsv = 1;
317 			break;
318 
319 		case 'h':
320 			hostinfo = 0;
321 			break;
322 
323 		case 'H':
324 			hostname = optarg;
325 			break;
326 
327 		case 'l':
328 			logging++;	/* > 1 == extra logging */
329 			break;
330 
331 		case 'm':
332 			noguestmod = 0;
333 			break;
334 
335 		case 'M':
336 			noguestmkd = 1;
337 			break;
338 
339 		case 'o':
340 			noretr = 1;
341 			break;
342 
343 		case 'O':
344 			noguestretr = 1;
345 			break;
346 
347 		case 'p':
348 			pid_file = optarg;
349 			break;
350 
351 		case 'P':
352 			bindport = optarg;
353 			break;
354 
355 		case 'r':
356 			readonly = 1;
357 			break;
358 
359 		case 'R':
360 			paranoid = 0;
361 			break;
362 
363 		case 'S':
364 			stats++;
365 			break;
366 
367 		case 't':
368 			timeout = atoi(optarg);
369 			if (maxtimeout < timeout)
370 				maxtimeout = timeout;
371 			break;
372 
373 		case 'T':
374 			maxtimeout = atoi(optarg);
375 			if (timeout > maxtimeout)
376 				timeout = maxtimeout;
377 			break;
378 
379 		case 'u':
380 		    {
381 			long val = 0;
382 
383 			val = strtol(optarg, &optarg, 8);
384 			if (*optarg != '\0' || val < 0)
385 				syslog(LOG_WARNING, "bad value for -u");
386 			else
387 				defumask = val;
388 			break;
389 		    }
390 		case 'U':
391 			restricted_data_ports = 0;
392 			break;
393 
394 		case 'v':
395 			ftpdebug++;
396 			break;
397 
398 		case 'W':
399 			dowtmp = 0;
400 			break;
401 
402 		default:
403 			syslog(LOG_WARNING, "unknown flag -%c ignored", optopt);
404 			break;
405 		}
406 	}
407 
408 	if (daemon_mode) {
409 		int *ctl_sock, fd, maxfd = -1, nfds, i;
410 		fd_set defreadfds, readfds;
411 		pid_t pid;
412 		struct pidfh *pfh;
413 
414 		if ((pfh = pidfile_open(pid_file, 0600, &pid)) == NULL) {
415 			if (errno == EEXIST) {
416 				syslog(LOG_ERR, "%s already running, pid %d",
417 				       getprogname(), (int)pid);
418 				exit(1);
419 			}
420 			syslog(LOG_WARNING, "pidfile_open: %m");
421 		}
422 
423 		/*
424 		 * Detach from parent.
425 		 */
426 		if (daemon(1, 1) < 0) {
427 			syslog(LOG_ERR, "failed to become a daemon");
428 			exit(1);
429 		}
430 
431 		if (pfh != NULL && pidfile_write(pfh) == -1)
432 			syslog(LOG_WARNING, "pidfile_write: %m");
433 
434 		sa.sa_handler = reapchild;
435 		sigaction(SIGCHLD, &sa, NULL);
436 
437 #ifdef VIRTUAL_HOSTING
438 		inithosts(family);
439 #endif
440 
441 		/*
442 		 * Open a socket, bind it to the FTP port, and start
443 		 * listening.
444 		 */
445 		ctl_sock = socksetup(family, bindname, bindport);
446 		if (ctl_sock == NULL)
447 			exit(1);
448 
449 		FD_ZERO(&defreadfds);
450 		for (i = 1; i <= *ctl_sock; i++) {
451 			FD_SET(ctl_sock[i], &defreadfds);
452 			if (listen(ctl_sock[i], 32) < 0) {
453 				syslog(LOG_ERR, "control listen: %m");
454 				exit(1);
455 			}
456 			if (maxfd < ctl_sock[i])
457 				maxfd = ctl_sock[i];
458 		}
459 
460 		/*
461 		 * Loop forever accepting connection requests and forking off
462 		 * children to handle them.
463 		 */
464 		while (1) {
465 			FD_COPY(&defreadfds, &readfds);
466 			nfds = select(maxfd + 1, &readfds, NULL, NULL, 0);
467 			if (nfds <= 0) {
468 				if (nfds < 0 && errno != EINTR)
469 					syslog(LOG_WARNING, "select: %m");
470 				continue;
471 			}
472 
473 			pid = -1;
474                         for (i = 1; i <= *ctl_sock; i++)
475 				if (FD_ISSET(ctl_sock[i], &readfds)) {
476 					addrlen = sizeof(his_addr);
477 					fd = accept(ctl_sock[i],
478 					    (struct sockaddr *)&his_addr,
479 					    &addrlen);
480 					if (fd == -1) {
481 						syslog(LOG_WARNING,
482 						       "accept: %m");
483 						continue;
484 					}
485 					switch (pid = fork()) {
486 					case 0:
487 						/* child */
488 						dup2(fd, 0);
489 						dup2(fd, 1);
490 						close(fd);
491 						for (i = 1; i <= *ctl_sock; i++)
492 							close(ctl_sock[i]);
493 						if (pfh != NULL)
494 							pidfile_close(pfh);
495 						goto gotchild;
496 					case -1:
497 						syslog(LOG_WARNING, "fork: %m");
498 						/* FALLTHROUGH */
499 					default:
500 						close(fd);
501 					}
502 				}
503 		}
504 	} else {
505 		addrlen = sizeof(his_addr);
506 		if (getpeername(0, (struct sockaddr *)&his_addr, &addrlen) < 0) {
507 			syslog(LOG_ERR, "getpeername (%s): %m",argv[0]);
508 			exit(1);
509 		}
510 
511 #ifdef VIRTUAL_HOSTING
512 		if (his_addr.su_family == AF_INET6 &&
513 		    IN6_IS_ADDR_V4MAPPED(&his_addr.su_sin6.sin6_addr))
514 			family = AF_INET;
515 		else
516 			family = his_addr.su_family;
517 		inithosts(family);
518 #endif
519 	}
520 
521 gotchild:
522 	sa.sa_handler = SIG_DFL;
523 	sigaction(SIGCHLD, &sa, NULL);
524 
525 	sa.sa_handler = sigurg;
526 	sa.sa_flags = 0;		/* don't restart syscalls for SIGURG */
527 	sigaction(SIGURG, &sa, NULL);
528 
529 	sigfillset(&sa.sa_mask);	/* block all signals in handler */
530 	sa.sa_flags = SA_RESTART;
531 	sa.sa_handler = sigquit;
532 	sigaction(SIGHUP, &sa, NULL);
533 	sigaction(SIGINT, &sa, NULL);
534 	sigaction(SIGQUIT, &sa, NULL);
535 	sigaction(SIGTERM, &sa, NULL);
536 
537 	sa.sa_handler = lostconn;
538 	sigaction(SIGPIPE, &sa, NULL);
539 
540 	addrlen = sizeof(ctrl_addr);
541 	if (getsockname(0, (struct sockaddr *)&ctrl_addr, &addrlen) < 0) {
542 		syslog(LOG_ERR, "getsockname (%s): %m",argv[0]);
543 		exit(1);
544 	}
545 	dataport = ntohs(ctrl_addr.su_port) - 1; /* as per RFC 959 */
546 #ifdef VIRTUAL_HOSTING
547 	/* select our identity from virtual host table */
548 	selecthost(&ctrl_addr);
549 #endif
550 #ifdef IP_TOS
551 	if (ctrl_addr.su_family == AF_INET)
552       {
553 	tos = IPTOS_LOWDELAY;
554 	if (setsockopt(0, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
555 		syslog(LOG_WARNING, "control setsockopt (IP_TOS): %m");
556       }
557 #endif
558 	/*
559 	 * Disable Nagle on the control channel so that we don't have to wait
560 	 * for peer's ACK before issuing our next reply.
561 	 */
562 	if (setsockopt(0, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) < 0)
563 		syslog(LOG_WARNING, "control setsockopt (TCP_NODELAY): %m");
564 
565 	data_source.su_port = htons(ntohs(ctrl_addr.su_port) - 1);
566 
567 	/* set this here so klogin can use it... */
568 	snprintf(ttyline, sizeof(ttyline), "ftp%d", getpid());
569 
570 	/* Try to handle urgent data inline */
571 #ifdef SO_OOBINLINE
572 	if (setsockopt(0, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on)) < 0)
573 		syslog(LOG_WARNING, "control setsockopt (SO_OOBINLINE): %m");
574 #endif
575 
576 #ifdef	F_SETOWN
577 	if (fcntl(fileno(stdin), F_SETOWN, getpid()) == -1)
578 		syslog(LOG_ERR, "fcntl F_SETOWN: %m");
579 #endif
580 	dolog((struct sockaddr *)&his_addr);
581 	/*
582 	 * Set up default state
583 	 */
584 	data = -1;
585 	type = TYPE_A;
586 	form = FORM_N;
587 	stru = STRU_F;
588 	mode = MODE_S;
589 	tmpline[0] = '\0';
590 
591 	/* If logins are disabled, print out the message. */
592 	if ((fd = fopen(_PATH_NOLOGIN,"r")) != NULL) {
593 		while (fgets(line, sizeof(line), fd) != NULL) {
594 			if ((cp = strchr(line, '\n')) != NULL)
595 				*cp = '\0';
596 			lreply(530, "%s", line);
597 		}
598 		fflush(stdout);
599 		fclose(fd);
600 		reply(530, "System not available.");
601 		exit(0);
602 	}
603 #ifdef VIRTUAL_HOSTING
604 	fd = fopen(thishost->welcome, "r");
605 #else
606 	fd = fopen(_PATH_FTPWELCOME, "r");
607 #endif
608 	if (fd != NULL) {
609 		while (fgets(line, sizeof(line), fd) != NULL) {
610 			if ((cp = strchr(line, '\n')) != NULL)
611 				*cp = '\0';
612 			lreply(220, "%s", line);
613 		}
614 		fflush(stdout);
615 		fclose(fd);
616 		/* reply(220,) must follow */
617 	}
618 #ifndef VIRTUAL_HOSTING
619 	if (hostname == NULL) {
620 		if ((hostname = malloc(MAXHOSTNAMELEN)) == NULL)
621 			fatalerror("Ran out of memory.");
622 		if (gethostname(hostname, MAXHOSTNAMELEN - 1) < 0)
623 			hostname[0] = '\0';
624 		hostname[MAXHOSTNAMELEN - 1] = '\0';
625 	}
626 #endif
627 	if (hostinfo)
628 		reply(220, "%s FTP server (%s) ready.", hostname, version);
629 	else
630 		reply(220, "FTP server ready.");
631 	for (;;)
632 		yyparse();
633 	/* NOTREACHED */
634 }
635 
636 static void
637 lostconn(int signo)
638 {
639 
640 	if (ftpdebug)
641 		syslog(LOG_DEBUG, "lost connection");
642 	dologout(1);
643 }
644 
645 static void
646 sigquit(int signo)
647 {
648 
649 	syslog(LOG_ERR, "got signal %d", signo);
650 	dologout(1);
651 }
652 
653 #ifdef VIRTUAL_HOSTING
654 /*
655  * read in virtual host tables (if they exist)
656  */
657 
658 static void
659 inithosts(int family)
660 {
661 	int insert;
662 	size_t len;
663 	FILE *fp;
664 	char *cp, *mp, *line;
665 	char *vhost, *anonuser, *statfile, *welcome, *loginmsg;
666 	struct ftphost *hrp, *lhrp;
667 	struct addrinfo hints, *res, *ai;
668 
669 	/*
670 	 * Fill in the default host information
671 	 */
672 	if (hostname == NULL) {
673 		if ((hostname = malloc(MAXHOSTNAMELEN)) == NULL)
674 			fatalerror("Ran out of memory.");
675 		if (gethostname(hostname, MAXHOSTNAMELEN - 1) < 0)
676 			hostname[0] = '\0';
677 		hostname[MAXHOSTNAMELEN - 1] = '\0';
678 	}
679 	if ((hrp = malloc(sizeof(struct ftphost))) == NULL)
680 		fatalerror("Ran out of memory.");
681 	hrp->hostname = hostname;
682 	hrp->hostinfo = NULL;
683 
684 	memset(&hints, 0, sizeof(hints));
685 	hints.ai_flags = AI_PASSIVE;
686 	hints.ai_family = family;
687 	hints.ai_socktype = SOCK_STREAM;
688 	if (getaddrinfo(hrp->hostname, NULL, &hints, &res) == 0)
689 		hrp->hostinfo = res;
690 	hrp->statfile = _PATH_FTPDSTATFILE;
691 	hrp->welcome  = _PATH_FTPWELCOME;
692 	hrp->loginmsg = _PATH_FTPLOGINMESG;
693 	hrp->anonuser = "ftp";
694 	hrp->next = NULL;
695 	thishost = firsthost = lhrp = hrp;
696 	if ((fp = fopen(_PATH_FTPHOSTS, "r")) != NULL) {
697 		int addrsize, gothost;
698 		void *addr;
699 		struct hostent *hp;
700 
701 		while ((line = fgetln(fp, &len)) != NULL) {
702 			int	i, hp_error;
703 
704 			/* skip comments */
705 			if (line[0] == '#')
706 				continue;
707 			if (line[len - 1] == '\n') {
708 				line[len - 1] = '\0';
709 				mp = NULL;
710 			} else {
711 				if ((mp = malloc(len + 1)) == NULL)
712 					fatalerror("Ran out of memory.");
713 				memcpy(mp, line, len);
714 				mp[len] = '\0';
715 				line = mp;
716 			}
717 			cp = strtok(line, " \t");
718 			/* skip empty lines */
719 			if (cp == NULL)
720 				goto nextline;
721 			vhost = cp;
722 
723 			/* set defaults */
724 			anonuser = "ftp";
725 			statfile = _PATH_FTPDSTATFILE;
726 			welcome  = _PATH_FTPWELCOME;
727 			loginmsg = _PATH_FTPLOGINMESG;
728 
729 			/*
730 			 * Preparse the line so we can use its info
731 			 * for all the addresses associated with
732 			 * the virtual host name.
733 			 * Field 0, the virtual host name, is special:
734 			 * it's already parsed off and will be strdup'ed
735 			 * later, after we know its canonical form.
736 			 */
737 			for (i = 1; i < 5 && (cp = strtok(NULL, " \t")); i++)
738 				if (*cp != '-' && (cp = strdup(cp)))
739 					switch (i) {
740 					case 1:	/* anon user permissions */
741 						anonuser = cp;
742 						break;
743 					case 2: /* statistics file */
744 						statfile = cp;
745 						break;
746 					case 3: /* welcome message */
747 						welcome  = cp;
748 						break;
749 					case 4: /* login message */
750 						loginmsg = cp;
751 						break;
752 					default: /* programming error */
753 						abort();
754 						/* NOTREACHED */
755 					}
756 
757 			hints.ai_flags = AI_PASSIVE;
758 			hints.ai_family = family;
759 			hints.ai_socktype = SOCK_STREAM;
760 			if (getaddrinfo(vhost, NULL, &hints, &res) != 0)
761 				goto nextline;
762 			for (ai = res; ai != NULL && ai->ai_addr != NULL;
763 			     ai = ai->ai_next) {
764 
765 			gothost = 0;
766 			for (hrp = firsthost; hrp != NULL; hrp = hrp->next) {
767 				struct addrinfo *hi;
768 
769 				for (hi = hrp->hostinfo; hi != NULL;
770 				     hi = hi->ai_next)
771 					if (hi->ai_addrlen == ai->ai_addrlen &&
772 					    memcmp(hi->ai_addr,
773 						   ai->ai_addr,
774 						   ai->ai_addr->sa_len) == 0) {
775 						gothost++;
776 						break;
777 					}
778 				if (gothost)
779 					break;
780 			}
781 			if (hrp == NULL) {
782 				if ((hrp = malloc(sizeof(struct ftphost))) == NULL)
783 					goto nextline;
784 				hrp->hostname = NULL;
785 				insert = 1;
786 			} else {
787 				if (hrp->hostinfo && hrp->hostinfo != res)
788 					freeaddrinfo(hrp->hostinfo);
789 				insert = 0; /* host already in the chain */
790 			}
791 			hrp->hostinfo = res;
792 
793 			/*
794 			 * determine hostname to use.
795 			 * force defined name if there is a valid alias
796 			 * otherwise fallback to primary hostname
797 			 */
798 			/* XXX: getaddrinfo() can't do alias check */
799 			switch(hrp->hostinfo->ai_family) {
800 			case AF_INET:
801 				addr = &((struct sockaddr_in *)hrp->hostinfo->ai_addr)->sin_addr;
802 				addrsize = sizeof(struct in_addr);
803 				break;
804 			case AF_INET6:
805 				addr = &((struct sockaddr_in6 *)hrp->hostinfo->ai_addr)->sin6_addr;
806 				addrsize = sizeof(struct in6_addr);
807 				break;
808 			default:
809 				/* should not reach here */
810 				freeaddrinfo(hrp->hostinfo);
811 				if (insert)
812 					free(hrp); /*not in chain, can free*/
813 				else
814 					hrp->hostinfo = NULL; /*mark as blank*/
815 				goto nextline;
816 				/* NOTREACHED */
817 			}
818 			if ((hp = getipnodebyaddr(addr, addrsize,
819 						  hrp->hostinfo->ai_family,
820 						  &hp_error)) != NULL) {
821 				if (strcmp(vhost, hp->h_name) != 0) {
822 					if (hp->h_aliases == NULL)
823 						vhost = hp->h_name;
824 					else {
825 						i = 0;
826 						while (hp->h_aliases[i] &&
827 						       strcmp(vhost, hp->h_aliases[i]) != 0)
828 							++i;
829 						if (hp->h_aliases[i] == NULL)
830 							vhost = hp->h_name;
831 					}
832 				}
833 			}
834 			if (hrp->hostname &&
835 			    strcmp(hrp->hostname, vhost) != 0) {
836 				free(hrp->hostname);
837 				hrp->hostname = NULL;
838 			}
839 			if (hrp->hostname == NULL &&
840 			    (hrp->hostname = strdup(vhost)) == NULL) {
841 				freeaddrinfo(hrp->hostinfo);
842 				hrp->hostinfo = NULL; /* mark as blank */
843 				if (hp)
844 					freehostent(hp);
845 				goto nextline;
846 			}
847 			hrp->anonuser = anonuser;
848 			hrp->statfile = statfile;
849 			hrp->welcome  = welcome;
850 			hrp->loginmsg = loginmsg;
851 			if (insert) {
852 				hrp->next  = NULL;
853 				lhrp->next = hrp;
854 				lhrp = hrp;
855 			}
856 			if (hp)
857 				freehostent(hp);
858 		      }
859 nextline:
860 			if (mp)
861 				free(mp);
862 		}
863 		fclose(fp);
864 	}
865 }
866 
867 static void
868 selecthost(union sockunion *su)
869 {
870 	struct ftphost	*hrp;
871 	u_int16_t port;
872 #ifdef INET6
873 	struct in6_addr *mapped_in6 = NULL;
874 #endif
875 	struct addrinfo *hi;
876 
877 #ifdef INET6
878 	/*
879 	 * XXX IPv4 mapped IPv6 addr consideraton,
880 	 * specified in rfc2373.
881 	 */
882 	if (su->su_family == AF_INET6 &&
883 	    IN6_IS_ADDR_V4MAPPED(&su->su_sin6.sin6_addr))
884 		mapped_in6 = &su->su_sin6.sin6_addr;
885 #endif
886 
887 	hrp = thishost = firsthost;	/* default */
888 	port = su->su_port;
889 	su->su_port = 0;
890 	while (hrp != NULL) {
891 	    for (hi = hrp->hostinfo; hi != NULL; hi = hi->ai_next) {
892 		if (memcmp(su, hi->ai_addr, hi->ai_addrlen) == 0) {
893 			thishost = hrp;
894 			goto found;
895 		}
896 #ifdef INET6
897 		/* XXX IPv4 mapped IPv6 addr consideraton */
898 		if (hi->ai_addr->sa_family == AF_INET && mapped_in6 != NULL &&
899 		    (memcmp(&mapped_in6->s6_addr[12],
900 			    &((struct sockaddr_in *)hi->ai_addr)->sin_addr,
901 			    sizeof(struct in_addr)) == 0)) {
902 			thishost = hrp;
903 			goto found;
904 		}
905 #endif
906 	    }
907 	    hrp = hrp->next;
908 	}
909 found:
910 	su->su_port = port;
911 	/* setup static variables as appropriate */
912 	hostname = thishost->hostname;
913 	ftpuser = thishost->anonuser;
914 }
915 #endif
916 
917 /*
918  * Helper function for sgetpwnam().
919  */
920 static char *
921 sgetsave(char *s)
922 {
923 	char *new = malloc(strlen(s) + 1);
924 
925 	if (new == NULL) {
926 		reply(421, "Ran out of memory.");
927 		dologout(1);
928 		/* NOTREACHED */
929 	}
930 	strcpy(new, s);
931 	return (new);
932 }
933 
934 /*
935  * Save the result of a getpwnam.  Used for USER command, since
936  * the data returned must not be clobbered by any other command
937  * (e.g., globbing).
938  * NB: The data returned by sgetpwnam() will remain valid until
939  * the next call to this function.  Its difference from getpwnam()
940  * is that sgetpwnam() is known to be called from ftpd code only.
941  */
942 static struct passwd *
943 sgetpwnam(char *name)
944 {
945 	static struct passwd save;
946 	struct passwd *p;
947 
948 	if ((p = getpwnam(name)) == NULL)
949 		return (p);
950 	if (save.pw_name) {
951 		free(save.pw_name);
952 		free(save.pw_passwd);
953 		free(save.pw_gecos);
954 		free(save.pw_dir);
955 		free(save.pw_shell);
956 	}
957 	save = *p;
958 	save.pw_name = sgetsave(p->pw_name);
959 	save.pw_passwd = sgetsave(p->pw_passwd);
960 	save.pw_gecos = sgetsave(p->pw_gecos);
961 	save.pw_dir = sgetsave(p->pw_dir);
962 	save.pw_shell = sgetsave(p->pw_shell);
963 	return (&save);
964 }
965 
966 static int login_attempts;	/* number of failed login attempts */
967 static int askpasswd;		/* had user command, ask for passwd */
968 static char curname[MAXLOGNAME];	/* current USER name */
969 
970 /*
971  * USER command.
972  * Sets global passwd pointer pw if named account exists and is acceptable;
973  * sets askpasswd if a PASS command is expected.  If logged in previously,
974  * need to reset state.  If name is "ftp" or "anonymous", the name is not in
975  * _PATH_FTPUSERS, and ftp account exists, set guest and pw, then just return.
976  * If account doesn't exist, ask for passwd anyway.  Otherwise, check user
977  * requesting login privileges.  Disallow anyone who does not have a standard
978  * shell as returned by getusershell().  Disallow anyone mentioned in the file
979  * _PATH_FTPUSERS to allow people such as root and uucp to be avoided.
980  */
981 void
982 user(char *name)
983 {
984 	char *cp, *shell;
985 
986 	if (logged_in) {
987 		if (guest) {
988 			reply(530, "Can't change user from guest login.");
989 			return;
990 		} else if (dochroot) {
991 			reply(530, "Can't change user from chroot user.");
992 			return;
993 		}
994 		end_login();
995 	}
996 
997 	guest = 0;
998 #ifdef VIRTUAL_HOSTING
999 	pw = sgetpwnam(thishost->anonuser);
1000 #else
1001 	pw = sgetpwnam("ftp");
1002 #endif
1003 	if (strcmp(name, "ftp") == 0 || strcmp(name, "anonymous") == 0) {
1004 		if (checkuser(_PATH_FTPUSERS, "ftp", 0, NULL) ||
1005 		    checkuser(_PATH_FTPUSERS, "anonymous", 0, NULL))
1006 			reply(530, "User %s access denied.", name);
1007 		else if (pw != NULL) {
1008 			guest = 1;
1009 			askpasswd = 1;
1010 			reply(331,
1011 			"Guest login ok, send your email address as password.");
1012 		} else
1013 			reply(530, "User %s unknown.", name);
1014 		if (!askpasswd && logging)
1015 			syslog(LOG_NOTICE,
1016 			    "ANONYMOUS FTP LOGIN REFUSED FROM %s", remotehost);
1017 		return;
1018 	}
1019 	if (anon_only != 0) {
1020 		reply(530, "Sorry, only anonymous ftp allowed.");
1021 		return;
1022 	}
1023 
1024 	if ((pw = sgetpwnam(name))) {
1025 		if ((shell = pw->pw_shell) == NULL || *shell == 0)
1026 			shell = _PATH_BSHELL;
1027 		setusershell();
1028 		while ((cp = getusershell()) != NULL)
1029 			if (strcmp(cp, shell) == 0)
1030 				break;
1031 		endusershell();
1032 
1033 		if (cp == NULL || checkuser(_PATH_FTPUSERS, name, 1, NULL)) {
1034 			reply(530, "User %s access denied.", name);
1035 			if (logging)
1036 				syslog(LOG_NOTICE,
1037 				    "FTP LOGIN REFUSED FROM %s, %s",
1038 				    remotehost, name);
1039 			pw = NULL;
1040 			return;
1041 		}
1042 	}
1043 	if (logging)
1044 		strncpy(curname, name, sizeof(curname)-1);
1045 
1046 	pwok = 0;
1047 #ifdef USE_PAM
1048 	/* XXX Kluge! The conversation mechanism needs to be fixed. */
1049 #endif
1050 	if (opiechallenge(&opiedata, name, opieprompt) == 0) {
1051 		pwok = (pw != NULL) &&
1052 		       opieaccessfile(remotehost) &&
1053 		       opiealways(pw->pw_dir);
1054 		reply(331, "Response to %s %s for %s.",
1055 		      opieprompt, pwok ? "requested" : "required", name);
1056 	} else {
1057 		pwok = 1;
1058 		reply(331, "Password required for %s.", name);
1059 	}
1060 	askpasswd = 1;
1061 	/*
1062 	 * Delay before reading passwd after first failed
1063 	 * attempt to slow down passwd-guessing programs.
1064 	 */
1065 	if (login_attempts)
1066 		sleep(login_attempts);
1067 }
1068 
1069 /*
1070  * Check if a user is in the file "fname",
1071  * return a pointer to a malloc'd string with the rest
1072  * of the matching line in "residue" if not NULL.
1073  */
1074 static int
1075 checkuser(char *fname, char *name, int pwset, char **residue)
1076 {
1077 	FILE *fd;
1078 	int found = 0;
1079 	size_t len;
1080 	char *line, *mp, *p;
1081 
1082 	if ((fd = fopen(fname, "r")) != NULL) {
1083 		while (!found && (line = fgetln(fd, &len)) != NULL) {
1084 			/* skip comments */
1085 			if (line[0] == '#')
1086 				continue;
1087 			if (line[len - 1] == '\n') {
1088 				line[len - 1] = '\0';
1089 				mp = NULL;
1090 			} else {
1091 				if ((mp = malloc(len + 1)) == NULL)
1092 					fatalerror("Ran out of memory.");
1093 				memcpy(mp, line, len);
1094 				mp[len] = '\0';
1095 				line = mp;
1096 			}
1097 			/* avoid possible leading and trailing whitespace */
1098 			p = strtok(line, " \t");
1099 			/* skip empty lines */
1100 			if (p == NULL)
1101 				goto nextline;
1102 			/*
1103 			 * if first chr is '@', check group membership
1104 			 */
1105 			if (p[0] == '@') {
1106 				int i = 0;
1107 				struct group *grp;
1108 
1109 				if (p[1] == '\0') /* single @ matches anyone */
1110 					found = 1;
1111 				else {
1112 					if ((grp = getgrnam(p+1)) == NULL)
1113 						goto nextline;
1114 					/*
1115 					 * Check user's default group
1116 					 */
1117 					if (pwset && grp->gr_gid == pw->pw_gid)
1118 						found = 1;
1119 					/*
1120 					 * Check supplementary groups
1121 					 */
1122 					while (!found && grp->gr_mem[i])
1123 						found = strcmp(name,
1124 							grp->gr_mem[i++])
1125 							== 0;
1126 				}
1127 			}
1128 			/*
1129 			 * Otherwise, just check for username match
1130 			 */
1131 			else
1132 				found = strcmp(p, name) == 0;
1133 			/*
1134 			 * Save the rest of line to "residue" if matched
1135 			 */
1136 			if (found && residue) {
1137 				if ((p = strtok(NULL, "")) != NULL)
1138 					p += strspn(p, " \t");
1139 				if (p && *p) {
1140 				 	if ((*residue = strdup(p)) == NULL)
1141 						fatalerror("Ran out of memory.");
1142 				} else
1143 					*residue = NULL;
1144 			}
1145 nextline:
1146 			if (mp)
1147 				free(mp);
1148 		}
1149 		fclose(fd);
1150 	}
1151 	return (found);
1152 }
1153 
1154 /*
1155  * Terminate login as previous user, if any, resetting state;
1156  * used when USER command is given or login fails.
1157  */
1158 static void
1159 end_login(void)
1160 {
1161 #ifdef USE_PAM
1162 	int e;
1163 #endif
1164 
1165 	seteuid(0);
1166 	if (logged_in && dowtmp)
1167 		ftpd_logwtmp(ttyline, "", NULL);
1168 	pw = NULL;
1169 #ifdef	LOGIN_CAP
1170 	/* XXX Missing LOGIN_SETMAC */
1171 	setusercontext(NULL, getpwuid(0), 0,
1172 		       LOGIN_SETPRIORITY|LOGIN_SETRESOURCES|LOGIN_SETUMASK);
1173 #endif
1174 #ifdef USE_PAM
1175 	if (pamh) {
1176 		if ((e = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS)
1177 			syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e));
1178 		if ((e = pam_close_session(pamh,0)) != PAM_SUCCESS)
1179 			syslog(LOG_ERR, "pam_close_session: %s", pam_strerror(pamh, e));
1180 		if ((e = pam_end(pamh, e)) != PAM_SUCCESS)
1181 			syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1182 		pamh = NULL;
1183 	}
1184 #endif
1185 	logged_in = 0;
1186 	guest = 0;
1187 	dochroot = 0;
1188 }
1189 
1190 #ifdef USE_PAM
1191 
1192 /*
1193  * the following code is stolen from imap-uw PAM authentication module and
1194  * login.c
1195  */
1196 #define COPY_STRING(s) (s ? strdup(s) : NULL)
1197 
1198 struct cred_t {
1199 	const char *uname;		/* user name */
1200 	const char *pass;		/* password */
1201 };
1202 typedef struct cred_t cred_t;
1203 
1204 static int
1205 auth_conv(int num_msg, const struct pam_message **msg,
1206 	  struct pam_response **resp, void *appdata)
1207 {
1208 	int i;
1209 	cred_t *cred = (cred_t *) appdata;
1210 	struct pam_response *reply;
1211 
1212 	reply = calloc(num_msg, sizeof *reply);
1213 	if (reply == NULL)
1214 		return PAM_BUF_ERR;
1215 
1216 	for (i = 0; i < num_msg; i++) {
1217 		switch (msg[i]->msg_style) {
1218 		case PAM_PROMPT_ECHO_ON:	/* assume want user name */
1219 			reply[i].resp_retcode = PAM_SUCCESS;
1220 			reply[i].resp = COPY_STRING(cred->uname);
1221 			/* PAM frees resp. */
1222 			break;
1223 		case PAM_PROMPT_ECHO_OFF:	/* assume want password */
1224 			reply[i].resp_retcode = PAM_SUCCESS;
1225 			reply[i].resp = COPY_STRING(cred->pass);
1226 			/* PAM frees resp. */
1227 			break;
1228 		case PAM_TEXT_INFO:
1229 		case PAM_ERROR_MSG:
1230 			reply[i].resp_retcode = PAM_SUCCESS;
1231 			reply[i].resp = NULL;
1232 			break;
1233 		default:			/* unknown message style */
1234 			free(reply);
1235 			return PAM_CONV_ERR;
1236 		}
1237 	}
1238 
1239 	*resp = reply;
1240 	return PAM_SUCCESS;
1241 }
1242 
1243 /*
1244  * Attempt to authenticate the user using PAM.  Returns 0 if the user is
1245  * authenticated, or 1 if not authenticated.  If some sort of PAM system
1246  * error occurs (e.g., the "/etc/pam.conf" file is missing) then this
1247  * function returns -1.  This can be used as an indication that we should
1248  * fall back to a different authentication mechanism.
1249  */
1250 static int
1251 auth_pam(struct passwd **ppw, const char *pass)
1252 {
1253 	const char *tmpl_user;
1254 	const void *item;
1255 	int rval;
1256 	int e;
1257 	cred_t auth_cred = { (*ppw)->pw_name, pass };
1258 	struct pam_conv conv = { &auth_conv, &auth_cred };
1259 
1260 	e = pam_start("ftpd", (*ppw)->pw_name, &conv, &pamh);
1261 	if (e != PAM_SUCCESS) {
1262 		/*
1263 		 * In OpenPAM, it's OK to pass NULL to pam_strerror()
1264 		 * if context creation has failed in the first place.
1265 		 */
1266 		syslog(LOG_ERR, "pam_start: %s", pam_strerror(NULL, e));
1267 		return -1;
1268 	}
1269 
1270 	e = pam_set_item(pamh, PAM_RHOST, remotehost);
1271 	if (e != PAM_SUCCESS) {
1272 		syslog(LOG_ERR, "pam_set_item(PAM_RHOST): %s",
1273 			pam_strerror(pamh, e));
1274 		if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
1275 			syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1276 		}
1277 		pamh = NULL;
1278 		return -1;
1279 	}
1280 
1281 	e = pam_authenticate(pamh, 0);
1282 	switch (e) {
1283 	case PAM_SUCCESS:
1284 		/*
1285 		 * With PAM we support the concept of a "template"
1286 		 * user.  The user enters a login name which is
1287 		 * authenticated by PAM, usually via a remote service
1288 		 * such as RADIUS or TACACS+.  If authentication
1289 		 * succeeds, a different but related "template" name
1290 		 * is used for setting the credentials, shell, and
1291 		 * home directory.  The name the user enters need only
1292 		 * exist on the remote authentication server, but the
1293 		 * template name must be present in the local password
1294 		 * database.
1295 		 *
1296 		 * This is supported by two various mechanisms in the
1297 		 * individual modules.  However, from the application's
1298 		 * point of view, the template user is always passed
1299 		 * back as a changed value of the PAM_USER item.
1300 		 */
1301 		if ((e = pam_get_item(pamh, PAM_USER, &item)) ==
1302 		    PAM_SUCCESS) {
1303 			tmpl_user = (const char *) item;
1304 			if (strcmp((*ppw)->pw_name, tmpl_user) != 0)
1305 				*ppw = getpwnam(tmpl_user);
1306 		} else
1307 			syslog(LOG_ERR, "Couldn't get PAM_USER: %s",
1308 			    pam_strerror(pamh, e));
1309 		rval = 0;
1310 		break;
1311 
1312 	case PAM_AUTH_ERR:
1313 	case PAM_USER_UNKNOWN:
1314 	case PAM_MAXTRIES:
1315 		rval = 1;
1316 		break;
1317 
1318 	default:
1319 		syslog(LOG_ERR, "pam_authenticate: %s", pam_strerror(pamh, e));
1320 		rval = -1;
1321 		break;
1322 	}
1323 
1324 	if (rval == 0) {
1325 		e = pam_acct_mgmt(pamh, 0);
1326 		if (e != PAM_SUCCESS) {
1327 			syslog(LOG_ERR, "pam_acct_mgmt: %s",
1328 						pam_strerror(pamh, e));
1329 			rval = 1;
1330 		}
1331 	}
1332 
1333 	if (rval != 0) {
1334 		if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
1335 			syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1336 		}
1337 		pamh = NULL;
1338 	}
1339 	return rval;
1340 }
1341 
1342 #endif /* USE_PAM */
1343 
1344 void
1345 pass(char *passwd)
1346 {
1347 	int rval;
1348 	FILE *fd;
1349 #ifdef	LOGIN_CAP
1350 	login_cap_t *lc = NULL;
1351 #endif
1352 #ifdef USE_PAM
1353 	int e;
1354 #endif
1355 	char *residue = NULL;
1356 	char *xpasswd;
1357 
1358 	if (logged_in || askpasswd == 0) {
1359 		reply(503, "Login with USER first.");
1360 		return;
1361 	}
1362 	askpasswd = 0;
1363 	if (!guest) {		/* "ftp" is only account allowed no password */
1364 		if (pw == NULL) {
1365 			rval = 1;	/* failure below */
1366 			goto skip;
1367 		}
1368 #ifdef USE_PAM
1369 		rval = auth_pam(&pw, passwd);
1370 		if (rval >= 0) {
1371 			opieunlock();
1372 			goto skip;
1373 		}
1374 #endif
1375 		if (opieverify(&opiedata, passwd) == 0)
1376 			xpasswd = pw->pw_passwd;
1377 		else if (pwok) {
1378 			xpasswd = crypt(passwd, pw->pw_passwd);
1379 			if (passwd[0] == '\0' && pw->pw_passwd[0] != '\0')
1380 				xpasswd = ":";
1381 		} else {
1382 			rval = 1;
1383 			goto skip;
1384 		}
1385 		rval = strcmp(pw->pw_passwd, xpasswd);
1386 		if (pw->pw_expire && time(NULL) >= pw->pw_expire)
1387 			rval = 1;	/* failure */
1388 skip:
1389 		/*
1390 		 * If rval == 1, the user failed the authentication check
1391 		 * above.  If rval == 0, either PAM or local authentication
1392 		 * succeeded.
1393 		 */
1394 		if (rval) {
1395 			reply(530, "Login incorrect.");
1396 			if (logging) {
1397 				syslog(LOG_NOTICE,
1398 				    "FTP LOGIN FAILED FROM %s",
1399 				    remotehost);
1400 				syslog(LOG_AUTHPRIV | LOG_NOTICE,
1401 				    "FTP LOGIN FAILED FROM %s, %s",
1402 				    remotehost, curname);
1403 			}
1404 			pw = NULL;
1405 			if (login_attempts++ >= 5) {
1406 				syslog(LOG_NOTICE,
1407 				    "repeated login failures from %s",
1408 				    remotehost);
1409 				exit(0);
1410 			}
1411 			return;
1412 		}
1413 	}
1414 	login_attempts = 0;		/* this time successful */
1415 	if (setegid(pw->pw_gid) < 0) {
1416 		reply(550, "Can't set gid.");
1417 		return;
1418 	}
1419 	/* May be overridden by login.conf */
1420 	umask(defumask);
1421 #ifdef	LOGIN_CAP
1422 	if ((lc = login_getpwclass(pw)) != NULL) {
1423 		char	remote_ip[NI_MAXHOST];
1424 
1425 		if (getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
1426 			remote_ip, sizeof(remote_ip) - 1, NULL, 0,
1427 			NI_NUMERICHOST))
1428 				*remote_ip = 0;
1429 		remote_ip[sizeof(remote_ip) - 1] = 0;
1430 		if (!auth_hostok(lc, remotehost, remote_ip)) {
1431 			syslog(LOG_INFO|LOG_AUTH,
1432 			    "FTP LOGIN FAILED (HOST) as %s: permission denied.",
1433 			    pw->pw_name);
1434 			reply(530, "Permission denied.");
1435 			pw = NULL;
1436 			return;
1437 		}
1438 		if (!auth_timeok(lc, time(NULL))) {
1439 			reply(530, "Login not available right now.");
1440 			pw = NULL;
1441 			return;
1442 		}
1443 	}
1444 	/* XXX Missing LOGIN_SETMAC */
1445 	setusercontext(lc, pw, 0,
1446 		LOGIN_SETLOGIN|LOGIN_SETGROUP|LOGIN_SETPRIORITY|
1447 		LOGIN_SETRESOURCES|LOGIN_SETUMASK);
1448 #else
1449 	setlogin(pw->pw_name);
1450 	initgroups(pw->pw_name, pw->pw_gid);
1451 #endif
1452 
1453 #ifdef USE_PAM
1454 	if (pamh) {
1455 		if ((e = pam_open_session(pamh, 0)) != PAM_SUCCESS) {
1456 			syslog(LOG_ERR, "pam_open_session: %s", pam_strerror(pamh, e));
1457 		} else if ((e = pam_setcred(pamh, PAM_ESTABLISH_CRED)) != PAM_SUCCESS) {
1458 			syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e));
1459 		}
1460 	}
1461 #endif
1462 
1463 	/* open wtmp before chroot */
1464 	if (dowtmp)
1465 		ftpd_logwtmp(ttyline, pw->pw_name,
1466 		    (struct sockaddr *)&his_addr);
1467 	logged_in = 1;
1468 
1469 	if (guest && stats && statfd < 0)
1470 #ifdef VIRTUAL_HOSTING
1471 		statfd = open(thishost->statfile, O_WRONLY|O_APPEND);
1472 #else
1473 		statfd = open(_PATH_FTPDSTATFILE, O_WRONLY|O_APPEND);
1474 #endif
1475 		if (statfd < 0)
1476 			stats = 0;
1477 
1478 	dochroot =
1479 		checkuser(_PATH_FTPCHROOT, pw->pw_name, 1, &residue)
1480 #ifdef	LOGIN_CAP	/* Allow login.conf configuration as well */
1481 		|| login_getcapbool(lc, "ftp-chroot", 0)
1482 #endif
1483 	;
1484 	chrootdir = NULL;
1485 	/*
1486 	 * For a chrooted local user,
1487 	 * a) see whether ftpchroot(5) specifies a chroot directory,
1488 	 * b) extract the directory pathname from the line,
1489 	 * c) expand it to the absolute pathname if necessary.
1490 	 */
1491 	if (dochroot && residue &&
1492 	    (chrootdir = strtok(residue, " \t")) != NULL) {
1493 		if (chrootdir[0] != '/')
1494 			asprintf(&chrootdir, "%s/%s", pw->pw_dir, chrootdir);
1495 		else
1496 			chrootdir = strdup(chrootdir); /* make it permanent */
1497 		if (chrootdir == NULL)
1498 			fatalerror("Ran out of memory.");
1499 	}
1500 	if (guest || dochroot) {
1501 		/*
1502 		 * If no chroot directory set yet, use the login directory.
1503 		 * Copy it so it can be modified while pw->pw_dir stays intact.
1504 		 */
1505 		if (chrootdir == NULL &&
1506 		    (chrootdir = strdup(pw->pw_dir)) == NULL)
1507 			fatalerror("Ran out of memory.");
1508 		/*
1509 		 * Check for the "/chroot/./home" syntax,
1510 		 * separate the chroot and home directory pathnames.
1511 		 */
1512 		if ((homedir = strstr(chrootdir, "/./")) != NULL) {
1513 			*(homedir++) = '\0';	/* wipe '/' */
1514 			homedir++;		/* skip '.' */
1515 		} else {
1516 			/*
1517 			 * We MUST do a chdir() after the chroot. Otherwise
1518 			 * the old current directory will be accessible as "."
1519 			 * outside the new root!
1520 			 */
1521 			homedir = "/";
1522 		}
1523 		/*
1524 		 * Finally, do chroot()
1525 		 */
1526 		if (chroot(chrootdir) < 0) {
1527 			reply(550, "Can't change root.");
1528 			goto bad;
1529 		}
1530 	} else	/* real user w/o chroot */
1531 		homedir = pw->pw_dir;
1532 	/*
1533 	 * Set euid *before* doing chdir() so
1534 	 * a) the user won't be carried to a directory that he couldn't reach
1535 	 *    on his own due to no permission to upper path components,
1536 	 * b) NFS mounted homedirs w/restrictive permissions will be accessible
1537 	 *    (uid 0 has no root power over NFS if not mapped explicitly.)
1538 	 */
1539 	if (seteuid(pw->pw_uid) < 0) {
1540 		reply(550, "Can't set uid.");
1541 		goto bad;
1542 	}
1543 	if (chdir(homedir) < 0) {
1544 		if (guest || dochroot) {
1545 			reply(550, "Can't change to base directory.");
1546 			goto bad;
1547 		} else {
1548 			if (chdir("/") < 0) {
1549 				reply(550, "Root is inaccessible.");
1550 				goto bad;
1551 			}
1552 			lreply(230, "No directory! Logging in with home=/.");
1553 		}
1554 	}
1555 
1556 	/*
1557 	 * Display a login message, if it exists.
1558 	 * N.B. reply(230,) must follow the message.
1559 	 */
1560 #ifdef VIRTUAL_HOSTING
1561 	fd = fopen(thishost->loginmsg, "r");
1562 #else
1563 	fd = fopen(_PATH_FTPLOGINMESG, "r");
1564 #endif
1565 	if (fd != NULL) {
1566 		char *cp, line[LINE_MAX];
1567 
1568 		while (fgets(line, sizeof(line), fd) != NULL) {
1569 			if ((cp = strchr(line, '\n')) != NULL)
1570 				*cp = '\0';
1571 			lreply(230, "%s", line);
1572 		}
1573 		fflush(stdout);
1574 		fclose(fd);
1575 	}
1576 	if (guest) {
1577 		if (ident != NULL)
1578 			free(ident);
1579 		ident = strdup(passwd);
1580 		if (ident == NULL)
1581 			fatalerror("Ran out of memory.");
1582 
1583 		reply(230, "Guest login ok, access restrictions apply.");
1584 #ifdef SETPROCTITLE
1585 #ifdef VIRTUAL_HOSTING
1586 		if (thishost != firsthost)
1587 			snprintf(proctitle, sizeof(proctitle),
1588 				 "%s: anonymous(%s)/%s", remotehost, hostname,
1589 				 passwd);
1590 		else
1591 #endif
1592 			snprintf(proctitle, sizeof(proctitle),
1593 				 "%s: anonymous/%s", remotehost, passwd);
1594 		setproctitle("%s", proctitle);
1595 #endif /* SETPROCTITLE */
1596 		if (logging)
1597 			syslog(LOG_INFO, "ANONYMOUS FTP LOGIN FROM %s, %s",
1598 			    remotehost, passwd);
1599 	} else {
1600 		if (dochroot)
1601 			reply(230, "User %s logged in, "
1602 				   "access restrictions apply.", pw->pw_name);
1603 		else
1604 			reply(230, "User %s logged in.", pw->pw_name);
1605 
1606 #ifdef SETPROCTITLE
1607 		snprintf(proctitle, sizeof(proctitle),
1608 			 "%s: user/%s", remotehost, pw->pw_name);
1609 		setproctitle("%s", proctitle);
1610 #endif /* SETPROCTITLE */
1611 		if (logging)
1612 			syslog(LOG_INFO, "FTP LOGIN FROM %s as %s",
1613 			    remotehost, pw->pw_name);
1614 	}
1615 	if (logging && (guest || dochroot))
1616 		syslog(LOG_INFO, "session root changed to %s", chrootdir);
1617 #ifdef	LOGIN_CAP
1618 	login_close(lc);
1619 #endif
1620 	if (residue)
1621 		free(residue);
1622 	return;
1623 bad:
1624 	/* Forget all about it... */
1625 #ifdef	LOGIN_CAP
1626 	login_close(lc);
1627 #endif
1628 	if (residue)
1629 		free(residue);
1630 	end_login();
1631 }
1632 
1633 void
1634 retrieve(char *cmd, char *name)
1635 {
1636 	FILE *fin, *dout;
1637 	struct stat st;
1638 	int (*closefunc)(FILE *);
1639 	time_t start;
1640 
1641 	if (cmd == NULL) {
1642 		fin = fopen(name, "r"), closefunc = fclose;
1643 		st.st_size = 0;
1644 	} else {
1645 		char line[BUFSIZ];
1646 
1647 		snprintf(line, sizeof(line), cmd, name), name = line;
1648 		fin = ftpd_popen(line, "r"), closefunc = ftpd_pclose;
1649 		st.st_size = -1;
1650 		st.st_blksize = BUFSIZ;
1651 	}
1652 	if (fin == NULL) {
1653 		if (errno != 0) {
1654 			perror_reply(550, name);
1655 			if (cmd == NULL) {
1656 				LOGCMD("get", name);
1657 			}
1658 		}
1659 		return;
1660 	}
1661 	byte_count = -1;
1662 	if (cmd == NULL) {
1663 		if (fstat(fileno(fin), &st) < 0) {
1664 			perror_reply(550, name);
1665 			goto done;
1666 		}
1667 		if (!S_ISREG(st.st_mode)) {
1668 			/*
1669 			 * Never sending a raw directory is a workaround
1670 			 * for buggy clients that will attempt to RETR
1671 			 * a directory before listing it, e.g., Mozilla.
1672 			 * Preventing a guest from getting irregular files
1673 			 * is a simple security measure.
1674 			 */
1675 			if (S_ISDIR(st.st_mode) || guest) {
1676 				reply(550, "%s: not a plain file.", name);
1677 				goto done;
1678 			}
1679 			st.st_size = -1;
1680 			/* st.st_blksize is set for all descriptor types */
1681 		}
1682 	}
1683 	if (restart_point) {
1684 		if (type == TYPE_A) {
1685 			off_t i, n;
1686 			int c;
1687 
1688 			n = restart_point;
1689 			i = 0;
1690 			while (i++ < n) {
1691 				if ((c=getc(fin)) == EOF) {
1692 					perror_reply(550, name);
1693 					goto done;
1694 				}
1695 				if (c == '\n')
1696 					i++;
1697 			}
1698 		} else if (lseek(fileno(fin), restart_point, L_SET) < 0) {
1699 			perror_reply(550, name);
1700 			goto done;
1701 		}
1702 	}
1703 	dout = dataconn(name, st.st_size, "w");
1704 	if (dout == NULL)
1705 		goto done;
1706 	time(&start);
1707 	send_data(fin, dout, st.st_blksize, st.st_size,
1708 		  restart_point == 0 && cmd == NULL && S_ISREG(st.st_mode));
1709 	if (cmd == NULL && guest && stats && byte_count > 0)
1710 		logxfer(name, byte_count, start);
1711 	fclose(dout);
1712 	data = -1;
1713 	pdata = -1;
1714 done:
1715 	if (cmd == NULL)
1716 		LOGBYTES("get", name, byte_count);
1717 	(*closefunc)(fin);
1718 }
1719 
1720 void
1721 store(char *name, char *mode, int unique)
1722 {
1723 	int fd;
1724 	FILE *fout, *din;
1725 	int (*closefunc)(FILE *);
1726 
1727 	if (*mode == 'a') {		/* APPE */
1728 		if (unique) {
1729 			/* Programming error */
1730 			syslog(LOG_ERR, "Internal: unique flag to APPE");
1731 			unique = 0;
1732 		}
1733 		if (guest && noguestmod) {
1734 			reply(550, "Appending to existing file denied.");
1735 			goto err;
1736 		}
1737 		restart_point = 0;	/* not affected by preceding REST */
1738 	}
1739 	if (unique)			/* STOU overrides REST */
1740 		restart_point = 0;
1741 	if (guest && noguestmod) {
1742 		if (restart_point) {	/* guest STOR w/REST */
1743 			reply(550, "Modifying existing file denied.");
1744 			goto err;
1745 		} else			/* treat guest STOR as STOU */
1746 			unique = 1;
1747 	}
1748 
1749 	if (restart_point)
1750 		mode = "r+";	/* so ASCII manual seek can work */
1751 	if (unique) {
1752 		if ((fd = guniquefd(name, &name)) < 0)
1753 			goto err;
1754 		fout = fdopen(fd, mode);
1755 	} else
1756 		fout = fopen(name, mode);
1757 	closefunc = fclose;
1758 	if (fout == NULL) {
1759 		perror_reply(553, name);
1760 		goto err;
1761 	}
1762 	byte_count = -1;
1763 	if (restart_point) {
1764 		if (type == TYPE_A) {
1765 			off_t i, n;
1766 			int c;
1767 
1768 			n = restart_point;
1769 			i = 0;
1770 			while (i++ < n) {
1771 				if ((c=getc(fout)) == EOF) {
1772 					perror_reply(550, name);
1773 					goto done;
1774 				}
1775 				if (c == '\n')
1776 					i++;
1777 			}
1778 			/*
1779 			 * We must do this seek to "current" position
1780 			 * because we are changing from reading to
1781 			 * writing.
1782 			 */
1783 			if (fseeko(fout, 0, SEEK_CUR) < 0) {
1784 				perror_reply(550, name);
1785 				goto done;
1786 			}
1787 		} else if (lseek(fileno(fout), restart_point, L_SET) < 0) {
1788 			perror_reply(550, name);
1789 			goto done;
1790 		}
1791 	}
1792 	din = dataconn(name, -1, "r");
1793 	if (din == NULL)
1794 		goto done;
1795 	if (receive_data(din, fout) == 0) {
1796 		if (unique)
1797 			reply(226, "Transfer complete (unique file name:%s).",
1798 			    name);
1799 		else
1800 			reply(226, "Transfer complete.");
1801 	}
1802 	fclose(din);
1803 	data = -1;
1804 	pdata = -1;
1805 done:
1806 	LOGBYTES(*mode == 'a' ? "append" : "put", name, byte_count);
1807 	(*closefunc)(fout);
1808 	return;
1809 err:
1810 	LOGCMD(*mode == 'a' ? "append" : "put" , name);
1811 	return;
1812 }
1813 
1814 static FILE *
1815 getdatasock(char *mode)
1816 {
1817 	int on = 1, s, t, tries;
1818 
1819 	if (data >= 0)
1820 		return (fdopen(data, mode));
1821 
1822 	s = socket(data_dest.su_family, SOCK_STREAM, 0);
1823 	if (s < 0)
1824 		goto bad;
1825 	if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
1826 		syslog(LOG_WARNING, "data setsockopt (SO_REUSEADDR): %m");
1827 	/* anchor socket to avoid multi-homing problems */
1828 	data_source = ctrl_addr;
1829 	data_source.su_port = htons(dataport);
1830 	seteuid(0);
1831 	for (tries = 1; ; tries++) {
1832 		/*
1833 		 * We should loop here since it's possible that
1834 		 * another ftpd instance has passed this point and is
1835 		 * trying to open a data connection in active mode now.
1836 		 * Until the other connection is opened, we'll be getting
1837 		 * EADDRINUSE because no SOCK_STREAM sockets in the system
1838 		 * can share both local and remote addresses, localIP:20
1839 		 * and *:* in this case.
1840 		 */
1841 		if (bind(s, (struct sockaddr *)&data_source,
1842 		    data_source.su_len) >= 0)
1843 			break;
1844 		if (errno != EADDRINUSE || tries > 10)
1845 			goto bad;
1846 		sleep(tries);
1847 	}
1848 	seteuid(pw->pw_uid);
1849 #ifdef IP_TOS
1850 	if (data_source.su_family == AF_INET)
1851       {
1852 	on = IPTOS_THROUGHPUT;
1853 	if (setsockopt(s, IPPROTO_IP, IP_TOS, &on, sizeof(int)) < 0)
1854 		syslog(LOG_WARNING, "data setsockopt (IP_TOS): %m");
1855       }
1856 #endif
1857 #ifdef TCP_NOPUSH
1858 	/*
1859 	 * Turn off push flag to keep sender TCP from sending short packets
1860 	 * at the boundaries of each write().
1861 	 */
1862 	on = 1;
1863 	if (setsockopt(s, IPPROTO_TCP, TCP_NOPUSH, &on, sizeof on) < 0)
1864 		syslog(LOG_WARNING, "data setsockopt (TCP_NOPUSH): %m");
1865 #endif
1866 	return (fdopen(s, mode));
1867 bad:
1868 	/* Return the real value of errno (close may change it) */
1869 	t = errno;
1870 	seteuid(pw->pw_uid);
1871 	close(s);
1872 	errno = t;
1873 	return (NULL);
1874 }
1875 
1876 static FILE *
1877 dataconn(char *name, off_t size, char *mode)
1878 {
1879 	char sizebuf[32];
1880 	FILE *file;
1881 	int retry = 0, tos, conerrno;
1882 
1883 	file_size = size;
1884 	byte_count = 0;
1885 	if (size != -1)
1886 		snprintf(sizebuf, sizeof(sizebuf),
1887 				" (%jd bytes)", (intmax_t)size);
1888 	else
1889 		*sizebuf = '\0';
1890 	if (pdata >= 0) {
1891 		union sockunion from;
1892 		socklen_t fromlen = ctrl_addr.su_len;
1893 		int flags, s;
1894 		struct timeval timeout;
1895 		fd_set set;
1896 
1897 		FD_ZERO(&set);
1898 		FD_SET(pdata, &set);
1899 
1900 		timeout.tv_usec = 0;
1901 		timeout.tv_sec = 120;
1902 
1903 		/*
1904 		 * Granted a socket is in the blocking I/O mode,
1905 		 * accept() will block after a successful select()
1906 		 * if the selected connection dies in between.
1907 		 * Therefore set the non-blocking I/O flag here.
1908 		 */
1909 		if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1910 		    fcntl(pdata, F_SETFL, flags | O_NONBLOCK) == -1)
1911 			goto pdata_err;
1912 		if (select(pdata+1, &set, NULL, NULL, &timeout) <= 0 ||
1913 		    (s = accept(pdata, (struct sockaddr *) &from, &fromlen)) < 0)
1914 			goto pdata_err;
1915 		close(pdata);
1916 		pdata = s;
1917 		/*
1918 		 * Unset the inherited non-blocking I/O flag
1919 		 * on the child socket so stdio can work on it.
1920 		 */
1921 		if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1922 		    fcntl(pdata, F_SETFL, flags & ~O_NONBLOCK) == -1)
1923 			goto pdata_err;
1924 #ifdef IP_TOS
1925 		if (from.su_family == AF_INET)
1926 	      {
1927 		tos = IPTOS_THROUGHPUT;
1928 		if (setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
1929 			syslog(LOG_WARNING, "pdata setsockopt (IP_TOS): %m");
1930 	      }
1931 #endif
1932 		reply(150, "Opening %s mode data connection for '%s'%s.",
1933 		     type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1934 		return (fdopen(pdata, mode));
1935 pdata_err:
1936 		reply(425, "Can't open data connection.");
1937 		close(pdata);
1938 		pdata = -1;
1939 		return (NULL);
1940 	}
1941 	if (data >= 0) {
1942 		reply(125, "Using existing data connection for '%s'%s.",
1943 		    name, sizebuf);
1944 		usedefault = 1;
1945 		return (fdopen(data, mode));
1946 	}
1947 	if (usedefault)
1948 		data_dest = his_addr;
1949 	usedefault = 1;
1950 	do {
1951 		file = getdatasock(mode);
1952 		if (file == NULL) {
1953 			char hostbuf[NI_MAXHOST], portbuf[NI_MAXSERV];
1954 
1955 			if (getnameinfo((struct sockaddr *)&data_source,
1956 				data_source.su_len,
1957 				hostbuf, sizeof(hostbuf) - 1,
1958 				portbuf, sizeof(portbuf) - 1,
1959 				NI_NUMERICHOST|NI_NUMERICSERV))
1960 					*hostbuf = *portbuf = 0;
1961 			hostbuf[sizeof(hostbuf) - 1] = 0;
1962 			portbuf[sizeof(portbuf) - 1] = 0;
1963 			reply(425, "Can't create data socket (%s,%s): %s.",
1964 				hostbuf, portbuf, strerror(errno));
1965 			return (NULL);
1966 		}
1967 		data = fileno(file);
1968 		conerrno = 0;
1969 		if (connect(data, (struct sockaddr *)&data_dest,
1970 		    data_dest.su_len) == 0)
1971 			break;
1972 		conerrno = errno;
1973 		fclose(file);
1974 		data = -1;
1975 		if (conerrno == EADDRINUSE) {
1976 			sleep(swaitint);
1977 			retry += swaitint;
1978 		} else {
1979 			break;
1980 		}
1981 	} while (retry <= swaitmax);
1982 	if (conerrno != 0) {
1983 		reply(425, "Can't build data connection: %s.",
1984 			   strerror(conerrno));
1985 		return (NULL);
1986 	}
1987 	reply(150, "Opening %s mode data connection for '%s'%s.",
1988 	     type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1989 	return (file);
1990 }
1991 
1992 /*
1993  * A helper macro to avoid code duplication
1994  * in send_data() and receive_data().
1995  *
1996  * XXX We have to block SIGURG during putc() because BSD stdio
1997  * is unable to restart interrupted write operations and hence
1998  * the entire buffer contents will be lost as soon as a write()
1999  * call indicates EINTR to stdio.
2000  */
2001 #define FTPD_PUTC(ch, file, label)					\
2002 	do {								\
2003 		int ret;						\
2004 									\
2005 		do {							\
2006 			START_UNSAFE;					\
2007 			ret = putc((ch), (file));			\
2008 			END_UNSAFE;					\
2009 			CHECKOOB(return (-1))				\
2010 			else if (ferror(file))				\
2011 				goto label;				\
2012 			clearerr(file);					\
2013 		} while (ret == EOF);					\
2014 	} while (0)
2015 
2016 /*
2017  * Tranfer the contents of "instr" to "outstr" peer using the appropriate
2018  * encapsulation of the data subject to Mode, Structure, and Type.
2019  *
2020  * NB: Form isn't handled.
2021  */
2022 static int
2023 send_data(FILE *instr, FILE *outstr, size_t blksize, off_t filesize, int isreg)
2024 {
2025 	int c, cp, filefd, netfd;
2026 	char *buf;
2027 
2028 	STARTXFER;
2029 
2030 	switch (type) {
2031 
2032 	case TYPE_A:
2033 		cp = EOF;
2034 		for (;;) {
2035 			c = getc(instr);
2036 			CHECKOOB(return (-1))
2037 			else if (c == EOF && ferror(instr))
2038 				goto file_err;
2039 			if (c == EOF) {
2040 				if (ferror(instr)) {	/* resume after OOB */
2041 					clearerr(instr);
2042 					continue;
2043 				}
2044 				if (feof(instr))	/* EOF */
2045 					break;
2046 				syslog(LOG_ERR, "Internal: impossible condition"
2047 						" on file after getc()");
2048 				goto file_err;
2049 			}
2050 			if (c == '\n' && cp != '\r') {
2051 				FTPD_PUTC('\r', outstr, data_err);
2052 				byte_count++;
2053 			}
2054 			FTPD_PUTC(c, outstr, data_err);
2055 			byte_count++;
2056 			cp = c;
2057 		}
2058 #ifdef notyet	/* BSD stdio isn't ready for that */
2059 		while (fflush(outstr) == EOF) {
2060 			CHECKOOB(return (-1))
2061 			else
2062 				goto data_err;
2063 			clearerr(outstr);
2064 		}
2065 		ENDXFER;
2066 #else
2067 		ENDXFER;
2068 		if (fflush(outstr) == EOF)
2069 			goto data_err;
2070 #endif
2071 		reply(226, "Transfer complete.");
2072 		return (0);
2073 
2074 	case TYPE_I:
2075 	case TYPE_L:
2076 		/*
2077 		 * isreg is only set if we are not doing restart and we
2078 		 * are sending a regular file
2079 		 */
2080 		netfd = fileno(outstr);
2081 		filefd = fileno(instr);
2082 
2083 		if (isreg) {
2084 			char *msg = "Transfer complete.";
2085 			off_t cnt, offset;
2086 			int err;
2087 
2088 			cnt = offset = 0;
2089 
2090 			while (filesize > 0) {
2091 				err = sendfile(filefd, netfd, offset, 0,
2092 					       NULL, &cnt, 0);
2093 				/*
2094 				 * Calculate byte_count before OOB processing.
2095 				 * It can be used in myoob() later.
2096 				 */
2097 				byte_count += cnt;
2098 				offset += cnt;
2099 				filesize -= cnt;
2100 				CHECKOOB(return (-1))
2101 				else if (err == -1) {
2102 					if (errno != EINTR &&
2103 					    cnt == 0 && offset == 0)
2104 						goto oldway;
2105 					goto data_err;
2106 				}
2107 				if (err == -1)	/* resume after OOB */
2108 					continue;
2109 				/*
2110 				 * We hit the EOF prematurely.
2111 				 * Perhaps the file was externally truncated.
2112 				 */
2113 				if (cnt == 0) {
2114 					msg = "Transfer finished due to "
2115 					      "premature end of file.";
2116 					break;
2117 				}
2118 			}
2119 			ENDXFER;
2120 			reply(226, msg);
2121 			return (0);
2122 		}
2123 
2124 oldway:
2125 		if ((buf = malloc(blksize)) == NULL) {
2126 			ENDXFER;
2127 			reply(451, "Ran out of memory.");
2128 			return (-1);
2129 		}
2130 
2131 		for (;;) {
2132 			int cnt, len;
2133 			char *bp;
2134 
2135 			cnt = read(filefd, buf, blksize);
2136 			CHECKOOB(free(buf); return (-1))
2137 			else if (cnt < 0) {
2138 				free(buf);
2139 				goto file_err;
2140 			}
2141 			if (cnt < 0)	/* resume after OOB */
2142 				continue;
2143 			if (cnt == 0)	/* EOF */
2144 				break;
2145 			for (len = cnt, bp = buf; len > 0;) {
2146 				cnt = write(netfd, bp, len);
2147 				CHECKOOB(free(buf); return (-1))
2148 				else if (cnt < 0) {
2149 					free(buf);
2150 					goto data_err;
2151 				}
2152 				if (cnt <= 0)
2153 					continue;
2154 				len -= cnt;
2155 				bp += cnt;
2156 				byte_count += cnt;
2157 			}
2158 		}
2159 		ENDXFER;
2160 		free(buf);
2161 		reply(226, "Transfer complete.");
2162 		return (0);
2163 	default:
2164 		ENDXFER;
2165 		reply(550, "Unimplemented TYPE %d in send_data.", type);
2166 		return (-1);
2167 	}
2168 
2169 data_err:
2170 	ENDXFER;
2171 	perror_reply(426, "Data connection");
2172 	return (-1);
2173 
2174 file_err:
2175 	ENDXFER;
2176 	perror_reply(551, "Error on input file");
2177 	return (-1);
2178 }
2179 
2180 /*
2181  * Transfer data from peer to "outstr" using the appropriate encapulation of
2182  * the data subject to Mode, Structure, and Type.
2183  *
2184  * N.B.: Form isn't handled.
2185  */
2186 static int
2187 receive_data(FILE *instr, FILE *outstr)
2188 {
2189 	int c, cp;
2190 	int bare_lfs = 0;
2191 
2192 	STARTXFER;
2193 
2194 	switch (type) {
2195 
2196 	case TYPE_I:
2197 	case TYPE_L:
2198 		for (;;) {
2199 			int cnt, len;
2200 			char *bp;
2201 			char buf[BUFSIZ];
2202 
2203 			cnt = read(fileno(instr), buf, sizeof(buf));
2204 			CHECKOOB(return (-1))
2205 			else if (cnt < 0)
2206 				goto data_err;
2207 			if (cnt < 0)	/* resume after OOB */
2208 				continue;
2209 			if (cnt == 0)	/* EOF */
2210 				break;
2211 			for (len = cnt, bp = buf; len > 0;) {
2212 				cnt = write(fileno(outstr), bp, len);
2213 				CHECKOOB(return (-1))
2214 				else if (cnt < 0)
2215 					goto file_err;
2216 				if (cnt <= 0)
2217 					continue;
2218 				len -= cnt;
2219 				bp += cnt;
2220 				byte_count += cnt;
2221 			}
2222 		}
2223 		ENDXFER;
2224 		return (0);
2225 
2226 	case TYPE_E:
2227 		ENDXFER;
2228 		reply(553, "TYPE E not implemented.");
2229 		return (-1);
2230 
2231 	case TYPE_A:
2232 		cp = EOF;
2233 		for (;;) {
2234 			c = getc(instr);
2235 			CHECKOOB(return (-1))
2236 			else if (c == EOF && ferror(instr))
2237 				goto data_err;
2238 			if (c == EOF && ferror(instr)) { /* resume after OOB */
2239 				clearerr(instr);
2240 				continue;
2241 			}
2242 
2243 			if (cp == '\r') {
2244 				if (c != '\n')
2245 					FTPD_PUTC('\r', outstr, file_err);
2246 			} else
2247 				if (c == '\n')
2248 					bare_lfs++;
2249 			if (c == '\r') {
2250 				byte_count++;
2251 				cp = c;
2252 				continue;
2253 			}
2254 
2255 			/* Check for EOF here in order not to lose last \r. */
2256 			if (c == EOF) {
2257 				if (feof(instr))	/* EOF */
2258 					break;
2259 				syslog(LOG_ERR, "Internal: impossible condition"
2260 						" on data stream after getc()");
2261 				goto data_err;
2262 			}
2263 
2264 			byte_count++;
2265 			FTPD_PUTC(c, outstr, file_err);
2266 			cp = c;
2267 		}
2268 #ifdef notyet	/* BSD stdio isn't ready for that */
2269 		while (fflush(outstr) == EOF) {
2270 			CHECKOOB(return (-1))
2271 			else
2272 				goto file_err;
2273 			clearerr(outstr);
2274 		}
2275 		ENDXFER;
2276 #else
2277 		ENDXFER;
2278 		if (fflush(outstr) == EOF)
2279 			goto file_err;
2280 #endif
2281 		if (bare_lfs) {
2282 			lreply(226,
2283 		"WARNING! %d bare linefeeds received in ASCII mode.",
2284 			    bare_lfs);
2285 		printf("   File may not have transferred correctly.\r\n");
2286 		}
2287 		return (0);
2288 	default:
2289 		ENDXFER;
2290 		reply(550, "Unimplemented TYPE %d in receive_data.", type);
2291 		return (-1);
2292 	}
2293 
2294 data_err:
2295 	ENDXFER;
2296 	perror_reply(426, "Data connection");
2297 	return (-1);
2298 
2299 file_err:
2300 	ENDXFER;
2301 	perror_reply(452, "Error writing to file");
2302 	return (-1);
2303 }
2304 
2305 void
2306 statfilecmd(char *filename)
2307 {
2308 	FILE *fin;
2309 	int atstart;
2310 	int c, code;
2311 	char line[LINE_MAX];
2312 	struct stat st;
2313 
2314 	code = lstat(filename, &st) == 0 && S_ISDIR(st.st_mode) ? 212 : 213;
2315 	snprintf(line, sizeof(line), _PATH_LS " -lgA %s", filename);
2316 	fin = ftpd_popen(line, "r");
2317 	lreply(code, "Status of %s:", filename);
2318 	atstart = 1;
2319 	while ((c = getc(fin)) != EOF) {
2320 		if (c == '\n') {
2321 			if (ferror(stdout)){
2322 				perror_reply(421, "Control connection");
2323 				ftpd_pclose(fin);
2324 				dologout(1);
2325 				/* NOTREACHED */
2326 			}
2327 			if (ferror(fin)) {
2328 				perror_reply(551, filename);
2329 				ftpd_pclose(fin);
2330 				return;
2331 			}
2332 			putc('\r', stdout);
2333 		}
2334 		/*
2335 		 * RFC 959 says neutral text should be prepended before
2336 		 * a leading 3-digit number followed by whitespace, but
2337 		 * many ftp clients can be confused by any leading digits,
2338 		 * as a matter of fact.
2339 		 */
2340 		if (atstart && isdigit(c))
2341 			putc(' ', stdout);
2342 		putc(c, stdout);
2343 		atstart = (c == '\n');
2344 	}
2345 	ftpd_pclose(fin);
2346 	reply(code, "End of status.");
2347 }
2348 
2349 void
2350 statcmd(void)
2351 {
2352 	union sockunion *su;
2353 	u_char *a, *p;
2354 	char hname[NI_MAXHOST];
2355 	int ispassive;
2356 
2357 	if (hostinfo) {
2358 		lreply(211, "%s FTP server status:", hostname);
2359 		printf("     %s\r\n", version);
2360 	} else
2361 		lreply(211, "FTP server status:");
2362 	printf("     Connected to %s", remotehost);
2363 	if (!getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
2364 			 hname, sizeof(hname) - 1, NULL, 0, NI_NUMERICHOST)) {
2365 		hname[sizeof(hname) - 1] = 0;
2366 		if (strcmp(hname, remotehost) != 0)
2367 			printf(" (%s)", hname);
2368 	}
2369 	printf("\r\n");
2370 	if (logged_in) {
2371 		if (guest)
2372 			printf("     Logged in anonymously\r\n");
2373 		else
2374 			printf("     Logged in as %s\r\n", pw->pw_name);
2375 	} else if (askpasswd)
2376 		printf("     Waiting for password\r\n");
2377 	else
2378 		printf("     Waiting for user name\r\n");
2379 	printf("     TYPE: %s", typenames[type]);
2380 	if (type == TYPE_A || type == TYPE_E)
2381 		printf(", FORM: %s", formnames[form]);
2382 	if (type == TYPE_L)
2383 #if CHAR_BIT == 8
2384 		printf(" %d", CHAR_BIT);
2385 #else
2386 		printf(" %d", bytesize);	/* need definition! */
2387 #endif
2388 	printf("; STRUcture: %s; transfer MODE: %s\r\n",
2389 	    strunames[stru], modenames[mode]);
2390 	if (data != -1)
2391 		printf("     Data connection open\r\n");
2392 	else if (pdata != -1) {
2393 		ispassive = 1;
2394 		su = &pasv_addr;
2395 		goto printaddr;
2396 	} else if (usedefault == 0) {
2397 		ispassive = 0;
2398 		su = &data_dest;
2399 printaddr:
2400 #define UC(b) (((int) b) & 0xff)
2401 		if (epsvall) {
2402 			printf("     EPSV only mode (EPSV ALL)\r\n");
2403 			goto epsvonly;
2404 		}
2405 
2406 		/* PORT/PASV */
2407 		if (su->su_family == AF_INET) {
2408 			a = (u_char *) &su->su_sin.sin_addr;
2409 			p = (u_char *) &su->su_sin.sin_port;
2410 			printf("     %s (%d,%d,%d,%d,%d,%d)\r\n",
2411 				ispassive ? "PASV" : "PORT",
2412 				UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
2413 				UC(p[0]), UC(p[1]));
2414 		}
2415 
2416 		/* LPRT/LPSV */
2417 	    {
2418 		int alen, af, i;
2419 
2420 		switch (su->su_family) {
2421 		case AF_INET:
2422 			a = (u_char *) &su->su_sin.sin_addr;
2423 			p = (u_char *) &su->su_sin.sin_port;
2424 			alen = sizeof(su->su_sin.sin_addr);
2425 			af = 4;
2426 			break;
2427 		case AF_INET6:
2428 			a = (u_char *) &su->su_sin6.sin6_addr;
2429 			p = (u_char *) &su->su_sin6.sin6_port;
2430 			alen = sizeof(su->su_sin6.sin6_addr);
2431 			af = 6;
2432 			break;
2433 		default:
2434 			af = 0;
2435 			break;
2436 		}
2437 		if (af) {
2438 			printf("     %s (%d,%d,", ispassive ? "LPSV" : "LPRT",
2439 				af, alen);
2440 			for (i = 0; i < alen; i++)
2441 				printf("%d,", UC(a[i]));
2442 			printf("%d,%d,%d)\r\n", 2, UC(p[0]), UC(p[1]));
2443 		}
2444 	    }
2445 
2446 epsvonly:;
2447 		/* EPRT/EPSV */
2448 	    {
2449 		int af;
2450 
2451 		switch (su->su_family) {
2452 		case AF_INET:
2453 			af = 1;
2454 			break;
2455 		case AF_INET6:
2456 			af = 2;
2457 			break;
2458 		default:
2459 			af = 0;
2460 			break;
2461 		}
2462 		if (af) {
2463 			union sockunion tmp;
2464 
2465 			tmp = *su;
2466 			if (tmp.su_family == AF_INET6)
2467 				tmp.su_sin6.sin6_scope_id = 0;
2468 			if (!getnameinfo((struct sockaddr *)&tmp, tmp.su_len,
2469 					hname, sizeof(hname) - 1, NULL, 0,
2470 					NI_NUMERICHOST)) {
2471 				hname[sizeof(hname) - 1] = 0;
2472 				printf("     %s |%d|%s|%d|\r\n",
2473 					ispassive ? "EPSV" : "EPRT",
2474 					af, hname, htons(tmp.su_port));
2475 			}
2476 		}
2477 	    }
2478 #undef UC
2479 	} else
2480 		printf("     No data connection\r\n");
2481 	reply(211, "End of status.");
2482 }
2483 
2484 void
2485 fatalerror(char *s)
2486 {
2487 
2488 	reply(451, "Error in server: %s", s);
2489 	reply(221, "Closing connection due to server error.");
2490 	dologout(0);
2491 	/* NOTREACHED */
2492 }
2493 
2494 void
2495 reply(int n, const char *fmt, ...)
2496 {
2497 	va_list ap;
2498 
2499 	printf("%d ", n);
2500 	va_start(ap, fmt);
2501 	vprintf(fmt, ap);
2502 	va_end(ap);
2503 	printf("\r\n");
2504 	fflush(stdout);
2505 	if (ftpdebug) {
2506 		syslog(LOG_DEBUG, "<--- %d ", n);
2507 		va_start(ap, fmt);
2508 		vsyslog(LOG_DEBUG, fmt, ap);
2509 		va_end(ap);
2510 	}
2511 }
2512 
2513 void
2514 lreply(int n, const char *fmt, ...)
2515 {
2516 	va_list ap;
2517 
2518 	printf("%d- ", n);
2519 	va_start(ap, fmt);
2520 	vprintf(fmt, ap);
2521 	va_end(ap);
2522 	printf("\r\n");
2523 	fflush(stdout);
2524 	if (ftpdebug) {
2525 		syslog(LOG_DEBUG, "<--- %d- ", n);
2526 		va_start(ap, fmt);
2527 		vsyslog(LOG_DEBUG, fmt, ap);
2528 		va_end(ap);
2529 	}
2530 }
2531 
2532 static void
2533 ack(char *s)
2534 {
2535 
2536 	reply(250, "%s command successful.", s);
2537 }
2538 
2539 void
2540 nack(char *s)
2541 {
2542 
2543 	reply(502, "%s command not implemented.", s);
2544 }
2545 
2546 /* ARGSUSED */
2547 void
2548 yyerror(char *s)
2549 {
2550 	char *cp;
2551 
2552 	if ((cp = strchr(cbuf,'\n')))
2553 		*cp = '\0';
2554 	reply(500, "%s: command not understood.", cbuf);
2555 }
2556 
2557 void
2558 delete(char *name)
2559 {
2560 	struct stat st;
2561 
2562 	LOGCMD("delete", name);
2563 	if (lstat(name, &st) < 0) {
2564 		perror_reply(550, name);
2565 		return;
2566 	}
2567 	if (S_ISDIR(st.st_mode)) {
2568 		if (rmdir(name) < 0) {
2569 			perror_reply(550, name);
2570 			return;
2571 		}
2572 		goto done;
2573 	}
2574 	if (guest && noguestmod) {
2575 		reply(550, "Operation not permitted.");
2576 		return;
2577 	}
2578 	if (unlink(name) < 0) {
2579 		perror_reply(550, name);
2580 		return;
2581 	}
2582 done:
2583 	ack("DELE");
2584 }
2585 
2586 void
2587 cwd(char *path)
2588 {
2589 
2590 	if (chdir(path) < 0)
2591 		perror_reply(550, path);
2592 	else
2593 		ack("CWD");
2594 }
2595 
2596 void
2597 makedir(char *name)
2598 {
2599 	char *s;
2600 
2601 	LOGCMD("mkdir", name);
2602 	if (guest && noguestmkd)
2603 		reply(550, "Operation not permitted.");
2604 	else if (mkdir(name, 0777) < 0)
2605 		perror_reply(550, name);
2606 	else {
2607 		if ((s = doublequote(name)) == NULL)
2608 			fatalerror("Ran out of memory.");
2609 		reply(257, "\"%s\" directory created.", s);
2610 		free(s);
2611 	}
2612 }
2613 
2614 void
2615 removedir(char *name)
2616 {
2617 
2618 	LOGCMD("rmdir", name);
2619 	if (rmdir(name) < 0)
2620 		perror_reply(550, name);
2621 	else
2622 		ack("RMD");
2623 }
2624 
2625 void
2626 pwd(void)
2627 {
2628 	char *s, path[MAXPATHLEN + 1];
2629 
2630 	if (getcwd(path, sizeof(path)) == NULL)
2631 		perror_reply(550, "Get current directory");
2632 	else {
2633 		if ((s = doublequote(path)) == NULL)
2634 			fatalerror("Ran out of memory.");
2635 		reply(257, "\"%s\" is current directory.", s);
2636 		free(s);
2637 	}
2638 }
2639 
2640 char *
2641 renamefrom(char *name)
2642 {
2643 	struct stat st;
2644 
2645 	if (guest && noguestmod) {
2646 		reply(550, "Operation not permitted.");
2647 		return (NULL);
2648 	}
2649 	if (lstat(name, &st) < 0) {
2650 		perror_reply(550, name);
2651 		return (NULL);
2652 	}
2653 	reply(350, "File exists, ready for destination name.");
2654 	return (name);
2655 }
2656 
2657 void
2658 renamecmd(char *from, char *to)
2659 {
2660 	struct stat st;
2661 
2662 	LOGCMD2("rename", from, to);
2663 
2664 	if (guest && (stat(to, &st) == 0)) {
2665 		reply(550, "%s: permission denied.", to);
2666 		return;
2667 	}
2668 
2669 	if (rename(from, to) < 0)
2670 		perror_reply(550, "rename");
2671 	else
2672 		ack("RNTO");
2673 }
2674 
2675 static void
2676 dolog(struct sockaddr *who)
2677 {
2678 	char who_name[NI_MAXHOST];
2679 
2680 	realhostname_sa(remotehost, sizeof(remotehost) - 1, who, who->sa_len);
2681 	remotehost[sizeof(remotehost) - 1] = 0;
2682 	if (getnameinfo(who, who->sa_len,
2683 		who_name, sizeof(who_name) - 1, NULL, 0, NI_NUMERICHOST))
2684 			*who_name = 0;
2685 	who_name[sizeof(who_name) - 1] = 0;
2686 
2687 #ifdef SETPROCTITLE
2688 #ifdef VIRTUAL_HOSTING
2689 	if (thishost != firsthost)
2690 		snprintf(proctitle, sizeof(proctitle), "%s: connected (to %s)",
2691 			 remotehost, hostname);
2692 	else
2693 #endif
2694 		snprintf(proctitle, sizeof(proctitle), "%s: connected",
2695 			 remotehost);
2696 	setproctitle("%s", proctitle);
2697 #endif /* SETPROCTITLE */
2698 
2699 	if (logging) {
2700 #ifdef VIRTUAL_HOSTING
2701 		if (thishost != firsthost)
2702 			syslog(LOG_INFO, "connection from %s (%s) to %s",
2703 			       remotehost, who_name, hostname);
2704 		else
2705 #endif
2706 			syslog(LOG_INFO, "connection from %s (%s)",
2707 			       remotehost, who_name);
2708 	}
2709 }
2710 
2711 /*
2712  * Record logout in wtmp file
2713  * and exit with supplied status.
2714  */
2715 void
2716 dologout(int status)
2717 {
2718 
2719 	if (logged_in && dowtmp) {
2720 		seteuid(0);
2721 		ftpd_logwtmp(ttyline, "", NULL);
2722 	}
2723 	/* beware of flushing buffers after a SIGPIPE */
2724 	_exit(status);
2725 }
2726 
2727 static void
2728 sigurg(int signo)
2729 {
2730 
2731 	recvurg = 1;
2732 }
2733 
2734 static void
2735 maskurg(int flag)
2736 {
2737 	int oerrno;
2738 	sigset_t sset;
2739 
2740 	if (!transflag) {
2741 		syslog(LOG_ERR, "Internal: maskurg() while no transfer");
2742 		return;
2743 	}
2744 	oerrno = errno;
2745 	sigemptyset(&sset);
2746 	sigaddset(&sset, SIGURG);
2747 	sigprocmask(flag ? SIG_BLOCK : SIG_UNBLOCK, &sset, NULL);
2748 	errno = oerrno;
2749 }
2750 
2751 static void
2752 flagxfer(int flag)
2753 {
2754 
2755 	if (flag) {
2756 		if (transflag)
2757 			syslog(LOG_ERR, "Internal: flagxfer(1): "
2758 					"transfer already under way");
2759 		transflag = 1;
2760 		maskurg(0);
2761 		recvurg = 0;
2762 	} else {
2763 		if (!transflag)
2764 			syslog(LOG_ERR, "Internal: flagxfer(0): "
2765 					"no active transfer");
2766 		maskurg(1);
2767 		transflag = 0;
2768 	}
2769 }
2770 
2771 /*
2772  * Returns 0 if OK to resume or -1 if abort requested.
2773  */
2774 static int
2775 myoob(void)
2776 {
2777 	char *cp;
2778 	int ret;
2779 
2780 	if (!transflag) {
2781 		syslog(LOG_ERR, "Internal: myoob() while no transfer");
2782 		return (0);
2783 	}
2784 	cp = tmpline;
2785 	ret = getline(cp, 7, stdin);
2786 	if (ret == -1) {
2787 		reply(221, "You could at least say goodbye.");
2788 		dologout(0);
2789 	} else if (ret == -2) {
2790 		/* Ignore truncated command. */
2791 		return (0);
2792 	}
2793 	upper(cp);
2794 	if (strcmp(cp, "ABOR\r\n") == 0) {
2795 		tmpline[0] = '\0';
2796 		reply(426, "Transfer aborted. Data connection closed.");
2797 		reply(226, "Abort successful.");
2798 		return (-1);
2799 	}
2800 	if (strcmp(cp, "STAT\r\n") == 0) {
2801 		tmpline[0] = '\0';
2802 		if (file_size != -1)
2803 			reply(213, "Status: %jd of %jd bytes transferred.",
2804 				   (intmax_t)byte_count, (intmax_t)file_size);
2805 		else
2806 			reply(213, "Status: %jd bytes transferred.",
2807 				   (intmax_t)byte_count);
2808 	}
2809 	return (0);
2810 }
2811 
2812 /*
2813  * Note: a response of 425 is not mentioned as a possible response to
2814  *	the PASV command in RFC959. However, it has been blessed as
2815  *	a legitimate response by Jon Postel in a telephone conversation
2816  *	with Rick Adams on 25 Jan 89.
2817  */
2818 void
2819 passive(void)
2820 {
2821 	socklen_t len;
2822 	int on;
2823 	char *p, *a;
2824 
2825 	if (pdata >= 0)		/* close old port if one set */
2826 		close(pdata);
2827 
2828 	pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2829 	if (pdata < 0) {
2830 		perror_reply(425, "Can't open passive connection");
2831 		return;
2832 	}
2833 	on = 1;
2834 	if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2835 		syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2836 
2837 	seteuid(0);
2838 
2839 #ifdef IP_PORTRANGE
2840 	if (ctrl_addr.su_family == AF_INET) {
2841 	    on = restricted_data_ports ? IP_PORTRANGE_HIGH
2842 				       : IP_PORTRANGE_DEFAULT;
2843 
2844 	    if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2845 			    &on, sizeof(on)) < 0)
2846 		    goto pasv_error;
2847 	}
2848 #endif
2849 #ifdef IPV6_PORTRANGE
2850 	if (ctrl_addr.su_family == AF_INET6) {
2851 	    on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
2852 				       : IPV6_PORTRANGE_DEFAULT;
2853 
2854 	    if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2855 			    &on, sizeof(on)) < 0)
2856 		    goto pasv_error;
2857 	}
2858 #endif
2859 
2860 	pasv_addr = ctrl_addr;
2861 	pasv_addr.su_port = 0;
2862 	if (bind(pdata, (struct sockaddr *)&pasv_addr, pasv_addr.su_len) < 0)
2863 		goto pasv_error;
2864 
2865 	seteuid(pw->pw_uid);
2866 
2867 	len = sizeof(pasv_addr);
2868 	if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
2869 		goto pasv_error;
2870 	if (listen(pdata, 1) < 0)
2871 		goto pasv_error;
2872 	if (pasv_addr.su_family == AF_INET)
2873 		a = (char *) &pasv_addr.su_sin.sin_addr;
2874 	else if (pasv_addr.su_family == AF_INET6 &&
2875 		 IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr))
2876 		a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
2877 	else
2878 		goto pasv_error;
2879 
2880 	p = (char *) &pasv_addr.su_port;
2881 
2882 #define UC(b) (((int) b) & 0xff)
2883 
2884 	reply(227, "Entering Passive Mode (%d,%d,%d,%d,%d,%d)", UC(a[0]),
2885 		UC(a[1]), UC(a[2]), UC(a[3]), UC(p[0]), UC(p[1]));
2886 	return;
2887 
2888 pasv_error:
2889 	seteuid(pw->pw_uid);
2890 	close(pdata);
2891 	pdata = -1;
2892 	perror_reply(425, "Can't open passive connection");
2893 	return;
2894 }
2895 
2896 /*
2897  * Long Passive defined in RFC 1639.
2898  *     228 Entering Long Passive Mode
2899  *         (af, hal, h1, h2, h3,..., pal, p1, p2...)
2900  */
2901 
2902 void
2903 long_passive(char *cmd, int pf)
2904 {
2905 	socklen_t len;
2906 	int on;
2907 	char *p, *a;
2908 
2909 	if (pdata >= 0)		/* close old port if one set */
2910 		close(pdata);
2911 
2912 	if (pf != PF_UNSPEC) {
2913 		if (ctrl_addr.su_family != pf) {
2914 			switch (ctrl_addr.su_family) {
2915 			case AF_INET:
2916 				pf = 1;
2917 				break;
2918 			case AF_INET6:
2919 				pf = 2;
2920 				break;
2921 			default:
2922 				pf = 0;
2923 				break;
2924 			}
2925 			/*
2926 			 * XXX
2927 			 * only EPRT/EPSV ready clients will understand this
2928 			 */
2929 			if (strcmp(cmd, "EPSV") == 0 && pf) {
2930 				reply(522, "Network protocol mismatch, "
2931 					"use (%d)", pf);
2932 			} else
2933 				reply(501, "Network protocol mismatch."); /*XXX*/
2934 
2935 			return;
2936 		}
2937 	}
2938 
2939 	pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2940 	if (pdata < 0) {
2941 		perror_reply(425, "Can't open passive connection");
2942 		return;
2943 	}
2944 	on = 1;
2945 	if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2946 		syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2947 
2948 	seteuid(0);
2949 
2950 	pasv_addr = ctrl_addr;
2951 	pasv_addr.su_port = 0;
2952 	len = pasv_addr.su_len;
2953 
2954 #ifdef IP_PORTRANGE
2955 	if (ctrl_addr.su_family == AF_INET) {
2956 	    on = restricted_data_ports ? IP_PORTRANGE_HIGH
2957 				       : IP_PORTRANGE_DEFAULT;
2958 
2959 	    if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2960 			    &on, sizeof(on)) < 0)
2961 		    goto pasv_error;
2962 	}
2963 #endif
2964 #ifdef IPV6_PORTRANGE
2965 	if (ctrl_addr.su_family == AF_INET6) {
2966 	    on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
2967 				       : IPV6_PORTRANGE_DEFAULT;
2968 
2969 	    if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2970 			    &on, sizeof(on)) < 0)
2971 		    goto pasv_error;
2972 	}
2973 #endif
2974 
2975 	if (bind(pdata, (struct sockaddr *)&pasv_addr, len) < 0)
2976 		goto pasv_error;
2977 
2978 	seteuid(pw->pw_uid);
2979 
2980 	if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
2981 		goto pasv_error;
2982 	if (listen(pdata, 1) < 0)
2983 		goto pasv_error;
2984 
2985 #define UC(b) (((int) b) & 0xff)
2986 
2987 	if (strcmp(cmd, "LPSV") == 0) {
2988 		p = (char *)&pasv_addr.su_port;
2989 		switch (pasv_addr.su_family) {
2990 		case AF_INET:
2991 			a = (char *) &pasv_addr.su_sin.sin_addr;
2992 		v4_reply:
2993 			reply(228,
2994 "Entering Long Passive Mode (%d,%d,%d,%d,%d,%d,%d,%d,%d)",
2995 			      4, 4, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
2996 			      2, UC(p[0]), UC(p[1]));
2997 			return;
2998 		case AF_INET6:
2999 			if (IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr)) {
3000 				a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
3001 				goto v4_reply;
3002 			}
3003 			a = (char *) &pasv_addr.su_sin6.sin6_addr;
3004 			reply(228,
3005 "Entering Long Passive Mode "
3006 "(%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d)",
3007 			      6, 16, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
3008 			      UC(a[4]), UC(a[5]), UC(a[6]), UC(a[7]),
3009 			      UC(a[8]), UC(a[9]), UC(a[10]), UC(a[11]),
3010 			      UC(a[12]), UC(a[13]), UC(a[14]), UC(a[15]),
3011 			      2, UC(p[0]), UC(p[1]));
3012 			return;
3013 		}
3014 	} else if (strcmp(cmd, "EPSV") == 0) {
3015 		switch (pasv_addr.su_family) {
3016 		case AF_INET:
3017 		case AF_INET6:
3018 			reply(229, "Entering Extended Passive Mode (|||%d|)",
3019 				ntohs(pasv_addr.su_port));
3020 			return;
3021 		}
3022 	} else {
3023 		/* more proper error code? */
3024 	}
3025 
3026 pasv_error:
3027 	seteuid(pw->pw_uid);
3028 	close(pdata);
3029 	pdata = -1;
3030 	perror_reply(425, "Can't open passive connection");
3031 	return;
3032 }
3033 
3034 /*
3035  * Generate unique name for file with basename "local"
3036  * and open the file in order to avoid possible races.
3037  * Try "local" first, then "local.1", "local.2" etc, up to "local.99".
3038  * Return descriptor to the file, set "name" to its name.
3039  *
3040  * Generates failure reply on error.
3041  */
3042 static int
3043 guniquefd(char *local, char **name)
3044 {
3045 	static char new[MAXPATHLEN];
3046 	struct stat st;
3047 	char *cp;
3048 	int count;
3049 	int fd;
3050 
3051 	cp = strrchr(local, '/');
3052 	if (cp)
3053 		*cp = '\0';
3054 	if (stat(cp ? local : ".", &st) < 0) {
3055 		perror_reply(553, cp ? local : ".");
3056 		return (-1);
3057 	}
3058 	if (cp) {
3059 		/*
3060 		 * Let not overwrite dirname with counter suffix.
3061 		 * -4 is for /nn\0
3062 		 * In this extreme case dot won't be put in front of suffix.
3063 		 */
3064 		if (strlen(local) > sizeof(new) - 4) {
3065 			reply(553, "Pathname too long.");
3066 			return (-1);
3067 		}
3068 		*cp = '/';
3069 	}
3070 	/* -4 is for the .nn<null> we put on the end below */
3071 	snprintf(new, sizeof(new) - 4, "%s", local);
3072 	cp = new + strlen(new);
3073 	/*
3074 	 * Don't generate dotfile unless requested explicitly.
3075 	 * This covers the case when basename gets truncated off
3076 	 * by buffer size.
3077 	 */
3078 	if (cp > new && cp[-1] != '/')
3079 		*cp++ = '.';
3080 	for (count = 0; count < 100; count++) {
3081 		/* At count 0 try unmodified name */
3082 		if (count)
3083 			sprintf(cp, "%d", count);
3084 		if ((fd = open(count ? new : local,
3085 		    O_RDWR | O_CREAT | O_EXCL, 0666)) >= 0) {
3086 			*name = count ? new : local;
3087 			return (fd);
3088 		}
3089 		if (errno != EEXIST) {
3090 			perror_reply(553, count ? new : local);
3091 			return (-1);
3092 		}
3093 	}
3094 	reply(452, "Unique file name cannot be created.");
3095 	return (-1);
3096 }
3097 
3098 /*
3099  * Format and send reply containing system error number.
3100  */
3101 void
3102 perror_reply(int code, char *string)
3103 {
3104 
3105 	reply(code, "%s: %s.", string, strerror(errno));
3106 }
3107 
3108 static char *onefile[] = {
3109 	"",
3110 	0
3111 };
3112 
3113 void
3114 send_file_list(char *whichf)
3115 {
3116 	struct stat st;
3117 	DIR *dirp = NULL;
3118 	struct dirent *dir;
3119 	FILE *dout = NULL;
3120 	char **dirlist, *dirname;
3121 	int simple = 0;
3122 	int freeglob = 0;
3123 	glob_t gl;
3124 
3125 	if (strpbrk(whichf, "~{[*?") != NULL) {
3126 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE;
3127 
3128 		memset(&gl, 0, sizeof(gl));
3129 		gl.gl_matchc = MAXGLOBARGS;
3130 		/*flags |= GLOB_LIMIT;*/
3131 		freeglob = 1;
3132 		if (glob(whichf, flags, 0, &gl)) {
3133 			reply(550, "No matching files found.");
3134 			goto out;
3135 		} else if (gl.gl_pathc == 0) {
3136 			errno = ENOENT;
3137 			perror_reply(550, whichf);
3138 			goto out;
3139 		}
3140 		dirlist = gl.gl_pathv;
3141 	} else {
3142 		onefile[0] = whichf;
3143 		dirlist = onefile;
3144 		simple = 1;
3145 	}
3146 
3147 	while ((dirname = *dirlist++)) {
3148 		if (stat(dirname, &st) < 0) {
3149 			/*
3150 			 * If user typed "ls -l", etc, and the client
3151 			 * used NLST, do what the user meant.
3152 			 */
3153 			if (dirname[0] == '-' && *dirlist == NULL &&
3154 			    dout == NULL)
3155 				retrieve(_PATH_LS " %s", dirname);
3156 			else
3157 				perror_reply(550, whichf);
3158 			goto out;
3159 		}
3160 
3161 		if (S_ISREG(st.st_mode)) {
3162 			if (dout == NULL) {
3163 				dout = dataconn("file list", -1, "w");
3164 				if (dout == NULL)
3165 					goto out;
3166 				STARTXFER;
3167 			}
3168 			START_UNSAFE;
3169 			fprintf(dout, "%s%s\n", dirname,
3170 				type == TYPE_A ? "\r" : "");
3171 			END_UNSAFE;
3172 			if (ferror(dout))
3173 				goto data_err;
3174 			byte_count += strlen(dirname) +
3175 				      (type == TYPE_A ? 2 : 1);
3176 			CHECKOOB(goto abrt);
3177 			continue;
3178 		} else if (!S_ISDIR(st.st_mode))
3179 			continue;
3180 
3181 		if ((dirp = opendir(dirname)) == NULL)
3182 			continue;
3183 
3184 		while ((dir = readdir(dirp)) != NULL) {
3185 			char nbuf[MAXPATHLEN];
3186 
3187 			CHECKOOB(goto abrt);
3188 
3189 			if (strcmp(dir->d_name, ".") == 0)
3190 				continue;
3191 			if (strcmp(dir->d_name, "..") == 0)
3192 				continue;
3193 
3194 			snprintf(nbuf, sizeof(nbuf),
3195 				"%s/%s", dirname, dir->d_name);
3196 
3197 			/*
3198 			 * We have to do a stat to insure it's
3199 			 * not a directory or special file.
3200 			 */
3201 			if (simple || (stat(nbuf, &st) == 0 &&
3202 			    S_ISREG(st.st_mode))) {
3203 				if (dout == NULL) {
3204 					dout = dataconn("file list", -1, "w");
3205 					if (dout == NULL)
3206 						goto out;
3207 					STARTXFER;
3208 				}
3209 				START_UNSAFE;
3210 				if (nbuf[0] == '.' && nbuf[1] == '/')
3211 					fprintf(dout, "%s%s\n", &nbuf[2],
3212 						type == TYPE_A ? "\r" : "");
3213 				else
3214 					fprintf(dout, "%s%s\n", nbuf,
3215 						type == TYPE_A ? "\r" : "");
3216 				END_UNSAFE;
3217 				if (ferror(dout))
3218 					goto data_err;
3219 				byte_count += strlen(nbuf) +
3220 					      (type == TYPE_A ? 2 : 1);
3221 				CHECKOOB(goto abrt);
3222 			}
3223 		}
3224 		closedir(dirp);
3225 		dirp = NULL;
3226 	}
3227 
3228 	if (dout == NULL)
3229 		reply(550, "No files found.");
3230 	else if (ferror(dout))
3231 data_err:	perror_reply(550, "Data connection");
3232 	else
3233 		reply(226, "Transfer complete.");
3234 out:
3235 	if (dout) {
3236 		ENDXFER;
3237 abrt:
3238 		fclose(dout);
3239 		data = -1;
3240 		pdata = -1;
3241 	}
3242 	if (dirp)
3243 		closedir(dirp);
3244 	if (freeglob) {
3245 		freeglob = 0;
3246 		globfree(&gl);
3247 	}
3248 }
3249 
3250 void
3251 reapchild(int signo)
3252 {
3253 	while (waitpid(-1, NULL, WNOHANG) > 0);
3254 }
3255 
3256 static void
3257 appendf(char **strp, char *fmt, ...)
3258 {
3259 	va_list ap;
3260 	char *ostr, *p;
3261 
3262 	va_start(ap, fmt);
3263 	vasprintf(&p, fmt, ap);
3264 	va_end(ap);
3265 	if (p == NULL)
3266 		fatalerror("Ran out of memory.");
3267 	if (*strp == NULL)
3268 		*strp = p;
3269 	else {
3270 		ostr = *strp;
3271 		asprintf(strp, "%s%s", ostr, p);
3272 		if (*strp == NULL)
3273 			fatalerror("Ran out of memory.");
3274 		free(ostr);
3275 	}
3276 }
3277 
3278 static void
3279 logcmd(char *cmd, char *file1, char *file2, off_t cnt)
3280 {
3281 	char *msg = NULL;
3282 	char wd[MAXPATHLEN + 1];
3283 
3284 	if (logging <= 1)
3285 		return;
3286 
3287 	if (getcwd(wd, sizeof(wd) - 1) == NULL)
3288 		strcpy(wd, strerror(errno));
3289 
3290 	appendf(&msg, "%s", cmd);
3291 	if (file1)
3292 		appendf(&msg, " %s", file1);
3293 	if (file2)
3294 		appendf(&msg, " %s", file2);
3295 	if (cnt >= 0)
3296 		appendf(&msg, " = %jd bytes", (intmax_t)cnt);
3297 	appendf(&msg, " (wd: %s", wd);
3298 	if (guest || dochroot)
3299 		appendf(&msg, "; chrooted");
3300 	appendf(&msg, ")");
3301 	syslog(LOG_INFO, "%s", msg);
3302 	free(msg);
3303 }
3304 
3305 static void
3306 logxfer(char *name, off_t size, time_t start)
3307 {
3308 	char buf[MAXPATHLEN + 1024];
3309 	char path[MAXPATHLEN + 1];
3310 	time_t now;
3311 
3312 	if (statfd >= 0) {
3313 		time(&now);
3314 		if (realpath(name, path) == NULL) {
3315 			syslog(LOG_NOTICE, "realpath failed on %s: %m", path);
3316 			return;
3317 		}
3318 		snprintf(buf, sizeof(buf), "%.20s!%s!%s!%s!%jd!%ld\n",
3319 			ctime(&now)+4, ident, remotehost,
3320 			path, (intmax_t)size,
3321 			(long)(now - start + (now == start)));
3322 		write(statfd, buf, strlen(buf));
3323 	}
3324 }
3325 
3326 static char *
3327 doublequote(char *s)
3328 {
3329 	int n;
3330 	char *p, *s2;
3331 
3332 	for (p = s, n = 0; *p; p++)
3333 		if (*p == '"')
3334 			n++;
3335 
3336 	if ((s2 = malloc(p - s + n + 1)) == NULL)
3337 		return (NULL);
3338 
3339 	for (p = s2; *s; s++, p++) {
3340 		if ((*p = *s) == '"')
3341 			*(++p) = '"';
3342 	}
3343 	*p = '\0';
3344 
3345 	return (s2);
3346 }
3347 
3348 /* setup server socket for specified address family */
3349 /* if af is PF_UNSPEC more than one socket may be returned */
3350 /* the returned list is dynamically allocated, so caller needs to free it */
3351 static int *
3352 socksetup(int af, char *bindname, const char *bindport)
3353 {
3354 	struct addrinfo hints, *res, *r;
3355 	int error, maxs, *s, *socks;
3356 	const int on = 1;
3357 
3358 	memset(&hints, 0, sizeof(hints));
3359 	hints.ai_flags = AI_PASSIVE;
3360 	hints.ai_family = af;
3361 	hints.ai_socktype = SOCK_STREAM;
3362 	error = getaddrinfo(bindname, bindport, &hints, &res);
3363 	if (error) {
3364 		syslog(LOG_ERR, "%s", gai_strerror(error));
3365 		if (error == EAI_SYSTEM)
3366 			syslog(LOG_ERR, "%s", strerror(errno));
3367 		return NULL;
3368 	}
3369 
3370 	/* Count max number of sockets we may open */
3371 	for (maxs = 0, r = res; r; r = r->ai_next, maxs++)
3372 		;
3373 	socks = malloc((maxs + 1) * sizeof(int));
3374 	if (!socks) {
3375 		freeaddrinfo(res);
3376 		syslog(LOG_ERR, "couldn't allocate memory for sockets");
3377 		return NULL;
3378 	}
3379 
3380 	*socks = 0;   /* num of sockets counter at start of array */
3381 	s = socks + 1;
3382 	for (r = res; r; r = r->ai_next) {
3383 		*s = socket(r->ai_family, r->ai_socktype, r->ai_protocol);
3384 		if (*s < 0) {
3385 			syslog(LOG_DEBUG, "control socket: %m");
3386 			continue;
3387 		}
3388 		if (setsockopt(*s, SOL_SOCKET, SO_REUSEADDR,
3389 		    &on, sizeof(on)) < 0)
3390 			syslog(LOG_WARNING,
3391 			    "control setsockopt (SO_REUSEADDR): %m");
3392 		if (r->ai_family == AF_INET6) {
3393 			if (setsockopt(*s, IPPROTO_IPV6, IPV6_V6ONLY,
3394 			    &on, sizeof(on)) < 0)
3395 				syslog(LOG_WARNING,
3396 				    "control setsockopt (IPV6_V6ONLY): %m");
3397 		}
3398 		if (bind(*s, r->ai_addr, r->ai_addrlen) < 0) {
3399 			syslog(LOG_DEBUG, "control bind: %m");
3400 			close(*s);
3401 			continue;
3402 		}
3403 		(*socks)++;
3404 		s++;
3405 	}
3406 
3407 	if (res)
3408 		freeaddrinfo(res);
3409 
3410 	if (*socks == 0) {
3411 		syslog(LOG_ERR, "control socket: Couldn't bind to any socket");
3412 		free(socks);
3413 		return NULL;
3414 	}
3415 	return(socks);
3416 }
3417