ftpd.c revision 1.192
1/*	$OpenBSD: ftpd.c,v 1.192 2010/08/27 12:00:21 lum Exp $	*/
2/*	$NetBSD: ftpd.c,v 1.15 1995/06/03 22:46:47 mycroft Exp $	*/
3
4/*
5 * Copyright (C) 1997 and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33/*
34 * Copyright (c) 1985, 1988, 1990, 1992, 1993, 1994
35 *	The Regents of the University of California.  All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 *    notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 *    notice, this list of conditions and the following disclaimer in the
44 *    documentation and/or other materials provided with the distribution.
45 * 3. Neither the name of the University nor the names of its contributors
46 *    may be used to endorse or promote products derived from this software
47 *    without specific prior written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 * SUCH DAMAGE.
60 */
61
62/*
63 * FTP server.
64 */
65#include <sys/param.h>
66#include <sys/stat.h>
67#include <sys/ioctl.h>
68#include <sys/socket.h>
69#include <sys/wait.h>
70#include <sys/mman.h>
71
72#include <netinet/in.h>
73#include <netinet/in_systm.h>
74#include <netinet/ip.h>
75#include <netinet/tcp.h>
76
77#define	FTP_NAMES
78#include <arpa/ftp.h>
79#include <arpa/inet.h>
80#include <arpa/telnet.h>
81
82#include <bsd_auth.h>
83#include <ctype.h>
84#include <dirent.h>
85#include <errno.h>
86#include <fcntl.h>
87#include <glob.h>
88#include <limits.h>
89#include <login_cap.h>
90#include <netdb.h>
91#include <pwd.h>
92#include <signal.h>
93#include <stdarg.h>
94#include <stdio.h>
95#include <stdlib.h>
96#include <string.h>
97#include <syslog.h>
98#include <time.h>
99#include <vis.h>
100#include <unistd.h>
101#include <util.h>
102#include <utmp.h>
103#include <poll.h>
104
105#if defined(TCPWRAPPERS)
106#include <tcpd.h>
107#endif	/* TCPWRAPPERS */
108
109#include "pathnames.h"
110#include "monitor.h"
111#include "extern.h"
112
113extern	off_t restart_point;
114extern	char cbuf[];
115
116union sockunion ctrl_addr;
117union sockunion data_source;
118union sockunion data_dest;
119union sockunion his_addr;
120union sockunion pasv_addr;
121
122sigset_t allsigs;
123
124int	daemon_mode = 0;
125int	data;
126int	logged_in;
127struct	passwd *pw;
128int	debug = 0;
129int	timeout = 900;    /* timeout after 15 minutes of inactivity */
130int	maxtimeout = 7200;/* don't allow idle time to be set beyond 2 hours */
131int	logging;
132int	anon_ok = 1;
133int	anon_only = 0;
134int	multihome = 0;
135int	guest;
136int	stats;
137int	statfd = -1;
138int	portcheck = 1;
139int	dochroot;
140int	type;
141int	form;
142int	stru;			/* avoid C keyword */
143int	mode;
144int	doutmp = 0;		/* update utmp file */
145int	usedefault = 1;		/* for data transfers */
146int	pdata = -1;		/* for passive mode */
147int	family = AF_UNSPEC;
148volatile sig_atomic_t transflag;
149off_t	file_size;
150off_t	byte_count;
151#if !defined(CMASK) || CMASK == 0
152#undef CMASK
153#define CMASK 022
154#endif
155mode_t	defumask = CMASK;		/* default umask value */
156int	umaskchange = 1;		/* allow user to change umask value. */
157char	tmpline[7];
158char	hostname[MAXHOSTNAMELEN];
159char	remotehost[MAXHOSTNAMELEN];
160char	dhostname[MAXHOSTNAMELEN];
161char	*guestpw;
162char	ttyline[20];
163#if 0
164char	*tty = ttyline;		/* for klogin */
165#endif
166static struct utmp utmp;	/* for utmp */
167static	login_cap_t *lc;
168static	auth_session_t *as;
169static	volatile sig_atomic_t recvurg;
170
171#if defined(TCPWRAPPERS)
172int	allow_severity = LOG_INFO;
173int	deny_severity = LOG_NOTICE;
174#endif	/* TCPWRAPPERS */
175
176int epsvall = 0;
177
178/*
179 * Timeout intervals for retrying connections
180 * to hosts that don't accept PORT cmds.  This
181 * is a kludge, but given the problems with TCP...
182 */
183#define	SWAITMAX	90	/* wait at most 90 seconds */
184#define	SWAITINT	5	/* interval between retries */
185
186int	swaitmax = SWAITMAX;
187int	swaitint = SWAITINT;
188
189#ifdef HASSETPROCTITLE
190char	proctitle[BUFSIZ];	/* initial part of title */
191#endif /* HASSETPROCTITLE */
192
193#define LOGCMD(cmd, file) \
194	if (logging > 1) \
195	    syslog(LOG_INFO,"%s %s%s", cmd, \
196		*(file) == '/' ? "" : curdir(), file);
197#define LOGCMD2(cmd, file1, file2) \
198	 if (logging > 1) \
199	    syslog(LOG_INFO,"%s %s%s %s%s", cmd, \
200		*(file1) == '/' ? "" : curdir(), file1, \
201		*(file2) == '/' ? "" : curdir(), file2);
202#define LOGBYTES(cmd, file, cnt) \
203	if (logging > 1) { \
204		if (cnt == (off_t)-1) \
205		    syslog(LOG_INFO,"%s %s%s", cmd, \
206			*(file) == '/' ? "" : curdir(), file); \
207		else \
208		    syslog(LOG_INFO, "%s %s%s = %qd bytes", \
209			cmd, (*(file) == '/') ? "" : curdir(), file, cnt); \
210	}
211
212static void	 ack(char *);
213static void	 sigurg(int);
214static void	 myoob(void);
215static int	 checkuser(char *, char *);
216static FILE	*dataconn(char *, off_t, char *);
217static void	 dolog(struct sockaddr *);
218static char	*copy_dir(char *, struct passwd *);
219static char	*curdir(void);
220static void	 end_login(void);
221static FILE	*getdatasock(char *);
222static int	 guniquefd(char *, char **);
223static void	 lostconn(int);
224static void	 sigquit(int);
225static int	 receive_data(FILE *, FILE *);
226static void	 replydirname(const char *, const char *);
227static int	 send_data(FILE *, FILE *, off_t, off_t, int);
228static struct passwd *
229		 sgetpwnam(char *, struct passwd *);
230static void	 reapchild(int);
231#if defined(TCPWRAPPERS)
232static int	 check_host(struct sockaddr *);
233#endif /* TCPWRAPPERS */
234static void	 usage(void);
235
236void	 logxfer(char *, off_t, time_t);
237void	 set_slave_signals(void);
238
239static char *
240curdir(void)
241{
242	static char path[MAXPATHLEN+1];	/* path + '/' */
243
244	if (getcwd(path, sizeof(path)-1) == NULL)
245		return ("");
246	if (path[1] != '\0')		/* special case for root dir. */
247		strlcat(path, "/", sizeof path);
248	/* For guest account, skip / since it's chrooted */
249	return (guest ? path+1 : path);
250}
251
252char *argstr = "AdDhnlMSt:T:u:UvP46";
253
254static void
255usage(void)
256{
257	syslog(LOG_ERR,
258	    "usage: ftpd [-46ADdlMnPSU] [-T maxtimeout] [-t timeout] [-u mask]");
259	exit(2);
260}
261
262int
263main(int argc, char *argv[])
264{
265	socklen_t addrlen;
266	int ch, on = 1, tos;
267	char line[LINE_MAX];
268	FILE *fp;
269	struct hostent *hp;
270	struct sigaction sa;
271	int error = 0;
272	const char *errstr;
273
274	tzset();		/* in case no timezone database in ~ftp */
275	sigfillset(&allsigs);	/* used to block signals while root */
276	sigemptyset(&sa.sa_mask);
277	sa.sa_flags = SA_RESTART;
278
279	while ((ch = getopt(argc, argv, argstr)) != -1) {
280		switch (ch) {
281		case 'A':
282			anon_only = 1;
283			break;
284
285		case 'd':
286		case 'v':		/* deprecated */
287			debug = 1;
288			break;
289
290		case 'D':
291			daemon_mode = 1;
292			break;
293
294		case 'P':
295			portcheck = 0;
296			break;
297
298		case 'h':		/* deprecated */
299			break;
300
301		case 'l':
302			logging++;	/* > 1 == extra logging */
303			break;
304
305		case 'M':
306			multihome = 1;
307			break;
308
309		case 'n':
310			anon_ok = 0;
311			break;
312
313		case 'S':
314			stats = 1;
315			break;
316
317		case 't':
318			timeout = strtonum(optarg, 0, INT_MAX, &errstr);
319			if (errstr) {
320				syslog(LOG_ERR,
321				    "%s is a bad value for -t, aborting",
322				    optarg);
323				exit(2);
324			}
325			if (maxtimeout < timeout)
326				maxtimeout = timeout;
327			break;
328
329		case 'T':
330			maxtimeout = strtonum(optarg, 0, INT_MAX,
331			    &errstr);
332			if (errstr) {
333				syslog(LOG_ERR,
334				    "%s is a bad value for -T, aborting",
335				    optarg);
336				exit(2);
337			}
338			if (timeout > maxtimeout)
339				timeout = maxtimeout;
340			break;
341
342		case 'u':
343		    {
344			long val = 0;
345			char *p;
346			umaskchange = 0;
347
348			val = strtol(optarg, &p, 8);
349			if (*optarg == '\0' || *p != '\0' || val < 0 ||
350			    (val & ~ACCESSPERMS)) {
351				syslog(LOG_ERR,
352				    "%s is a bad value for -u, aborting",
353				    optarg);
354				exit(2);
355			}
356			defumask = val;
357			break;
358		    }
359
360		case 'U':
361			doutmp = 1;
362			break;
363
364		case '4':
365			family = AF_INET;
366			break;
367
368		case '6':
369			family = AF_INET6;
370			break;
371
372		default:
373			usage();
374			break;
375		}
376	}
377
378	(void) freopen(_PATH_DEVNULL, "w", stderr);
379
380	/*
381	 * LOG_NDELAY sets up the logging connection immediately,
382	 * necessary for anonymous ftp's that chroot and can't do it later.
383	 */
384	openlog("ftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
385
386	if (getpwnam(FTPD_PRIVSEP_USER) == NULL) {
387		syslog(LOG_ERR, "privilege separation user %s not found",
388		    FTPD_PRIVSEP_USER);
389		exit(1);
390	}
391	endpwent();
392
393	if (daemon_mode) {
394		int *fds, i, fd;
395		struct pollfd *pfds;
396		struct addrinfo hints, *res, *res0;
397		nfds_t n;
398
399		/*
400		 * Detach from parent.
401		 */
402		if (daemon(1, 1) < 0) {
403			syslog(LOG_ERR, "failed to become a daemon");
404			exit(1);
405		}
406		sa.sa_handler = reapchild;
407		(void) sigaction(SIGCHLD, &sa, NULL);
408
409		memset(&hints, 0, sizeof(hints));
410		hints.ai_family = family;
411		hints.ai_socktype = SOCK_STREAM;
412		hints.ai_protocol = IPPROTO_TCP;
413		hints.ai_flags = AI_PASSIVE;
414		error = getaddrinfo(NULL, "ftp", &hints, &res0);
415		if (error) {
416			syslog(LOG_ERR, "%s", gai_strerror(error));
417			exit(1);
418		}
419
420		n = 0;
421		for (res = res0; res; res = res->ai_next)
422			n++;
423
424		fds = calloc(n, sizeof(int));
425		pfds = calloc(n, sizeof(struct pollfd));
426		if (!fds || !pfds) {
427			syslog(LOG_ERR, "%s", strerror(errno));
428			exit(1);
429		}
430
431		/*
432		 * Open sockets, bind it to the FTP port, and start
433		 * listening.
434		 */
435		n = 0;
436		for (res = res0; res; res = res->ai_next) {
437			fds[n] = socket(res->ai_family, res->ai_socktype,
438			    res->ai_protocol);
439			if (fds[n] < 0)
440				continue;
441
442			if (setsockopt(fds[n], SOL_SOCKET, SO_REUSEADDR,
443			    &on, sizeof(on)) < 0) {
444				close(fds[n]);
445				fds[n] = -1;
446				continue;
447			}
448
449			if (bind(fds[n], res->ai_addr, res->ai_addrlen) < 0) {
450				close(fds[n]);
451				fds[n] = -1;
452				continue;
453			}
454			if (listen(fds[n], 32) < 0) {
455				close(fds[n]);
456				fds[n] = -1;
457				continue;
458			}
459
460			pfds[n].fd = fds[n];
461			pfds[n].events = POLLIN;
462			n++;
463		}
464		freeaddrinfo(res0);
465
466		if (n == 0) {
467			syslog(LOG_ERR, "could not open control socket");
468			exit(1);
469		}
470
471		/* Stash pid in pidfile */
472		if (pidfile(NULL))
473			syslog(LOG_ERR, "can't open pidfile: %m");
474		/*
475		 * Loop forever accepting connection requests and forking off
476		 * children to handle them.
477		 */
478		while (1) {
479			if (poll(pfds, n, INFTIM) < 0) {
480				if (errno == EINTR)
481					continue;
482				syslog(LOG_ERR, "poll: %m");
483				exit(1);
484			}
485			for (i = 0; i < n; i++)
486				if (pfds[i].revents & POLLIN) {
487					addrlen = sizeof(his_addr);
488					fd = accept(pfds[i].fd,
489					    (struct sockaddr *)&his_addr,
490					    &addrlen);
491					if (fd != -1) {
492						if (fork() == 0)
493							goto child;
494						close(fd);
495					}
496				}
497		}
498
499	child:
500		/* child */
501		(void)dup2(fd, STDIN_FILENO);
502		(void)dup2(fd, STDOUT_FILENO);
503		for (i = 0; i < n; i++)
504			close(fds[i]);
505#if defined(TCPWRAPPERS)
506		/* ..in the child. */
507		if (!check_host((struct sockaddr *)&his_addr))
508			exit(1);
509#endif	/* TCPWRAPPERS */
510	} else {
511		addrlen = sizeof(his_addr);
512		if (getpeername(0, (struct sockaddr *)&his_addr,
513		    &addrlen) < 0) {
514			/* syslog(LOG_ERR, "getpeername (%s): %m", argv[0]); */
515			exit(1);
516		}
517	}
518
519	/* set this here so klogin can use it... */
520	(void)snprintf(ttyline, sizeof(ttyline), "ftp%ld", (long)getpid());
521
522	set_slave_signals();
523
524	addrlen = sizeof(ctrl_addr);
525	if (getsockname(0, (struct sockaddr *)&ctrl_addr, &addrlen) < 0) {
526		syslog(LOG_ERR, "getsockname: %m");
527		exit(1);
528	}
529	if (his_addr.su_family == AF_INET6 &&
530	    IN6_IS_ADDR_V4MAPPED(&his_addr.su_sin6.sin6_addr)) {
531#if 1
532		/*
533		 * IPv4 control connection arrived to AF_INET6 socket.
534		 * I hate to do this, but this is the easiest solution.
535		 */
536		union sockunion tmp_addr;
537		const int off = sizeof(struct in6_addr) - sizeof(struct in_addr);
538
539		tmp_addr = his_addr;
540		memset(&his_addr, 0, sizeof(his_addr));
541		his_addr.su_sin.sin_family = AF_INET;
542		his_addr.su_sin.sin_len = sizeof(his_addr.su_sin);
543		memcpy(&his_addr.su_sin.sin_addr,
544		    &tmp_addr.su_sin6.sin6_addr.s6_addr[off],
545		    sizeof(his_addr.su_sin.sin_addr));
546		his_addr.su_sin.sin_port = tmp_addr.su_sin6.sin6_port;
547
548		tmp_addr = ctrl_addr;
549		memset(&ctrl_addr, 0, sizeof(ctrl_addr));
550		ctrl_addr.su_sin.sin_family = AF_INET;
551		ctrl_addr.su_sin.sin_len = sizeof(ctrl_addr.su_sin);
552		memcpy(&ctrl_addr.su_sin.sin_addr,
553		    &tmp_addr.su_sin6.sin6_addr.s6_addr[off],
554		    sizeof(ctrl_addr.su_sin.sin_addr));
555		ctrl_addr.su_sin.sin_port = tmp_addr.su_sin6.sin6_port;
556#else
557		while (fgets(line, sizeof(line), fd) != NULL) {
558			line[strcspn(line, "\n")] = '\0';
559			lreply(530, "%s", line);
560		}
561		(void) fflush(stdout);
562		(void) close(fd);
563		reply(530,
564			"Connection from IPv4 mapped address is not supported.");
565		exit(0);
566#endif
567	}
568#ifdef IP_TOS
569	if (his_addr.su_family == AF_INET) {
570		tos = IPTOS_LOWDELAY;
571		if (setsockopt(0, IPPROTO_IP, IP_TOS, &tos,
572		    sizeof(int)) < 0)
573			syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
574	}
575#endif
576	data_source.su_port = htons(ntohs(ctrl_addr.su_port) - 1);
577
578	/* Try to handle urgent data inline */
579#ifdef SO_OOBINLINE
580	if (setsockopt(0, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on)) < 0)
581		syslog(LOG_ERR, "setsockopt: %m");
582#endif
583
584	dolog((struct sockaddr *)&his_addr);
585
586	/*
587	 * Set up default state
588	 */
589	data = -1;
590	type = TYPE_A;
591	form = FORM_N;
592	stru = STRU_F;
593	mode = MODE_S;
594	tmpline[0] = '\0';
595
596	/* If logins are disabled, print out the message. */
597	if ((fp = fopen(_PATH_NOLOGIN, "r")) != NULL) {
598		while (fgets(line, sizeof(line), fp) != NULL) {
599			line[strcspn(line, "\n")] = '\0';
600			lreply(530, "%s", line);
601		}
602		(void) fflush(stdout);
603		(void) fclose(fp);
604		reply(530, "System not available.");
605		exit(0);
606	}
607	if ((fp = fopen(_PATH_FTPWELCOME, "r")) != NULL) {
608		while (fgets(line, sizeof(line), fp) != NULL) {
609			line[strcspn(line, "\n")] = '\0';
610			lreply(220, "%s", line);
611		}
612		(void) fflush(stdout);
613		(void) fclose(fp);
614		/* reply(220,) must follow */
615	}
616	(void) gethostname(hostname, sizeof(hostname));
617
618	/* Make sure hostname is fully qualified. */
619	hp = gethostbyname(hostname);
620	if (hp != NULL)
621		strlcpy(hostname, hp->h_name, sizeof(hostname));
622
623	if (multihome) {
624		error = getnameinfo((struct sockaddr *)&ctrl_addr,
625		    ctrl_addr.su_len, dhostname, sizeof(dhostname), NULL, 0, 0);
626	}
627
628	if (error != 0)
629		reply(220, "FTP server ready.");
630	else
631		reply(220, "%s FTP server ready.",
632		    (multihome ? dhostname : hostname));
633
634	monitor_init();
635
636	for (;;)
637		(void) yyparse();
638	/* NOTREACHED */
639}
640
641/*
642 * Signal handlers.
643 */
644/*ARGSUSED*/
645static void
646lostconn(int signo)
647{
648	struct syslog_data sdata = SYSLOG_DATA_INIT;
649
650	sdata.log_fac = LOG_FTP;
651	if (debug)
652		syslog_r(LOG_DEBUG, &sdata, "lost connection");
653	dologout(1);
654}
655
656static void
657sigquit(int signo)
658{
659	struct syslog_data sdata = SYSLOG_DATA_INIT;
660
661	sdata.log_fac = LOG_FTP;
662	syslog_r(LOG_DEBUG, &sdata, "got signal %s", sys_signame[signo]);
663	dologout(1);
664}
665
666/*
667 * Save the result of a getpwnam.  Used for USER command, since
668 * the data returned must not be clobbered by any other command
669 * (e.g., globbing).
670 */
671static struct passwd *
672sgetpwnam(char *name, struct passwd *pw)
673{
674	static struct passwd *save;
675	struct passwd *old;
676
677	if (pw == NULL && (pw = getpwnam(name)) == NULL)
678		return (NULL);
679	old = save;
680	save = pw_dup(pw);
681	if (save == NULL) {
682		perror_reply(421, "Local resource failure: malloc");
683		dologout(1);
684		/* NOTREACHED */
685	}
686	if (old) {
687		memset(old->pw_passwd, 0, strlen(old->pw_passwd));
688		free(old);
689	}
690	return (save);
691}
692
693static int login_attempts;	/* number of failed login attempts */
694static int askpasswd;		/* had user command, ask for passwd */
695static char curname[MAXLOGNAME];	/* current USER name */
696
697/*
698 * USER command.
699 * Sets global passwd pointer pw if named account exists and is acceptable;
700 * sets askpasswd if a PASS command is expected.  If logged in previously,
701 * need to reset state.  If name is "ftp" or "anonymous", the name is not in
702 * _PATH_FTPUSERS, and ftp account exists, set guest and pw, then just return.
703 * If account doesn't exist, ask for passwd anyway.  Otherwise, check user
704 * requesting login privileges.  Disallow anyone who does not have a standard
705 * shell as returned by getusershell().  Disallow anyone mentioned in the file
706 * _PATH_FTPUSERS to allow people such as root and uucp to be avoided.
707 */
708void
709user(char *name)
710{
711	char *cp, *shell, *style, *host;
712	char *class = NULL;
713
714	if (logged_in) {
715		kill_slave("user already logged in");
716		end_login();
717	}
718
719	/* Close session from previous user if there was one. */
720	if (as) {
721		auth_close(as);
722		as = NULL;
723	}
724	if (lc) {
725		login_close(lc);
726		lc = NULL;
727	}
728
729	if ((style = strchr(name, ':')) != NULL)
730		*style++ = 0;
731
732	guest = 0;
733	askpasswd = 0;
734	host = multihome ? dhostname : hostname;
735	if (anon_ok &&
736	    (strcmp(name, "ftp") == 0 || strcmp(name, "anonymous") == 0)) {
737		if (checkuser(_PATH_FTPUSERS, "ftp") ||
738		    checkuser(_PATH_FTPUSERS, "anonymous"))
739			reply(530, "User %s access denied.", name);
740		else if ((pw = sgetpwnam("ftp", NULL)) != NULL) {
741			if ((lc = login_getclass(pw->pw_class)) == NULL ||
742			    (as = auth_open()) == NULL ||
743			    auth_setpwd(as, pw) != 0 ||
744			    auth_setoption(as, "FTPD_HOST", host) < 0) {
745				if (as) {
746					auth_close(as);
747					as = NULL;
748				}
749				if (lc) {
750					login_close(lc);
751					lc = NULL;
752				}
753				reply(421, "Local resource failure");
754				return;
755			}
756			guest = 1;
757			askpasswd = 1;
758			reply(331,
759			"Guest login ok, send your email address as password.");
760		} else
761			reply(530, "User %s unknown.", name);
762		if (!askpasswd && logging)
763			syslog(LOG_NOTICE,
764			    "ANONYMOUS FTP LOGIN REFUSED FROM %s", remotehost);
765		return;
766	}
767
768	shell = _PATH_BSHELL;
769	if ((pw = sgetpwnam(name, NULL))) {
770		class = pw->pw_class;
771		if (pw->pw_shell != NULL && *pw->pw_shell != '\0')
772			shell = pw->pw_shell;
773		while ((cp = getusershell()) != NULL)
774			if (strcmp(cp, shell) == 0)
775				break;
776		shell = cp;
777		endusershell();
778	}
779
780	/* Get login class; if invalid style treat like unknown user. */
781	lc = login_getclass(class);
782	if (lc && (style = login_getstyle(lc, style, "auth-ftp")) == NULL) {
783		login_close(lc);
784		lc = NULL;
785		pw = NULL;
786	}
787
788	/* Do pre-authentication setup. */
789	if (lc && ((as = auth_open()) == NULL ||
790	    (pw != NULL && auth_setpwd(as, pw) != 0) ||
791	    auth_setitem(as, AUTHV_STYLE, style) < 0 ||
792	    auth_setitem(as, AUTHV_NAME, name) < 0 ||
793	    auth_setitem(as, AUTHV_CLASS, class) < 0 ||
794	    auth_setoption(as, "login", "yes") < 0 ||
795	    auth_setoption(as, "notickets", "yes") < 0 ||
796	    auth_setoption(as, "FTPD_HOST", host) < 0)) {
797		if (as) {
798			auth_close(as);
799			as = NULL;
800		}
801		login_close(lc);
802		lc = NULL;
803		reply(421, "Local resource failure");
804		return;
805	}
806	if (logging)
807		strlcpy(curname, name, sizeof(curname));
808
809	dochroot = (lc && login_getcapbool(lc, "ftp-chroot", 0)) ||
810	    checkuser(_PATH_FTPCHROOT, name);
811	if (anon_only && !dochroot) {
812		reply(530, "User %s access denied.", name);
813		return;
814	}
815	if (pw) {
816		if ((!shell && !dochroot) || checkuser(_PATH_FTPUSERS, name)) {
817			reply(530, "User %s access denied.", name);
818			if (logging)
819				syslog(LOG_NOTICE,
820				    "FTP LOGIN REFUSED FROM %s, %s",
821				    remotehost, name);
822			pw = NULL;
823			return;
824		}
825	}
826
827	if (as != NULL && (cp = auth_challenge(as)) != NULL)
828		reply(331, "%s", cp);
829	else
830		reply(331, "Password required for %s.", name);
831
832	askpasswd = 1;
833	/*
834	 * Delay before reading passwd after first failed
835	 * attempt to slow down passwd-guessing programs.
836	 */
837	if (login_attempts)
838		sleep((unsigned) login_attempts);
839}
840
841/*
842 * Check if a user is in the file "fname"
843 */
844static int
845checkuser(char *fname, char *name)
846{
847	FILE *fp;
848	int found = 0;
849	char *p, line[BUFSIZ];
850
851	if ((fp = fopen(fname, "r")) != NULL) {
852		while (fgets(line, sizeof(line), fp) != NULL)
853			if ((p = strchr(line, '\n')) != NULL) {
854				*p = '\0';
855				if (line[0] == '#')
856					continue;
857				if (strcmp(line, name) == 0) {
858					found = 1;
859					break;
860				}
861			}
862		(void) fclose(fp);
863	}
864	return (found);
865}
866
867/*
868 * Terminate login as previous user, if any, resetting state;
869 * used when USER command is given or login fails.
870 */
871static void
872end_login(void)
873{
874	sigprocmask (SIG_BLOCK, &allsigs, NULL);
875	if (logged_in) {
876		ftpdlogwtmp(ttyline, "", "");
877		if (doutmp)
878			ftpd_logout(utmp.ut_line);
879	}
880	reply(530, "Please reconnect to work as another user");
881	_exit(0);
882}
883
884enum auth_ret
885pass(char *passwd)
886{
887	int authok;
888	unsigned int flags;
889	FILE *fp;
890	static char homedir[MAXPATHLEN];
891	char *motd, *dir, rootdir[MAXPATHLEN];
892	size_t sz_pw_dir;
893
894	if (logged_in || askpasswd == 0) {
895		reply(503, "Login with USER first.");
896		return (AUTH_FAILED);
897	}
898	askpasswd = 0;
899	if (!guest) {		/* "ftp" is only account allowed no password */
900		authok = 0;
901		if (pw == NULL || pw->pw_passwd[0] == '\0') {
902			useconds_t us;
903
904			/* Sleep between 1 and 3 seconds to emulate a crypt. */
905			us = arc4random_uniform(3000000);
906			usleep(us);
907			if (as != NULL) {
908				auth_close(as);
909				as = NULL;
910			}
911		} else {
912			authok = auth_userresponse(as, passwd, 0);
913			as = NULL;
914		}
915		if (authok == 0) {
916			reply(530, "Login incorrect.");
917			if (logging)
918				syslog(LOG_NOTICE,
919				    "FTP LOGIN FAILED FROM %s, %s",
920				    remotehost, curname);
921			pw = NULL;
922			if (login_attempts++ >= 5) {
923				syslog(LOG_NOTICE,
924				    "repeated login failures from %s",
925				    remotehost);
926				kill_slave("repeated login failures");
927				_exit(0);
928			}
929			return (AUTH_FAILED);
930		}
931	} else if (lc != NULL) {
932		/* Save anonymous' password. */
933		if (guestpw != NULL)
934			free(guestpw);
935		guestpw = strdup(passwd);
936		if (guestpw == NULL) {
937			kill_slave("out of mem");
938			fatal("Out of memory.");
939		}
940
941		authok = auth_approval(as, lc, pw->pw_name, "ftp");
942		auth_close(as);
943		as = NULL;
944		if (authok == 0) {
945			syslog(LOG_INFO|LOG_AUTH,
946			    "FTP LOGIN FAILED (HOST) as %s: approval failure.",
947			    pw->pw_name);
948			reply(530, "Approval failure.");
949			kill_slave("approval failure");
950			_exit(0);
951		}
952	} else {
953		syslog(LOG_INFO|LOG_AUTH,
954		    "FTP LOGIN CLASS %s MISSING for %s: approval failure.",
955		    pw->pw_class, pw->pw_name);
956		reply(530, "Permission denied.");
957		kill_slave("permission denied");
958		_exit(0);
959	}
960
961	if (monitor_post_auth() == 1) {
962		/* Post-auth monitor process */
963		logged_in = 1;
964		return (AUTH_MONITOR);
965	}
966
967	login_attempts = 0;		/* this time successful */
968	/* set umask via setusercontext() unless -u flag was given. */
969	flags = LOGIN_SETGROUP|LOGIN_SETPRIORITY|LOGIN_SETRESOURCES;
970	if (umaskchange)
971		flags |= LOGIN_SETUMASK;
972	else
973		(void) umask(defumask);
974	if (setusercontext(lc, pw, (uid_t)0, flags) != 0) {
975		perror_reply(421, "Local resource failure: setusercontext");
976		syslog(LOG_NOTICE, "setusercontext: %m");
977		dologout(1);
978		/* NOTREACHED */
979	}
980
981	/* open wtmp before chroot */
982	ftpdlogwtmp(ttyline, pw->pw_name, remotehost);
983
984	/* open utmp before chroot */
985	if (doutmp) {
986		memset((void *)&utmp, 0, sizeof(utmp));
987		(void)time(&utmp.ut_time);
988		(void)strncpy(utmp.ut_name, pw->pw_name, sizeof(utmp.ut_name));
989		(void)strncpy(utmp.ut_host, remotehost, sizeof(utmp.ut_host));
990		(void)strncpy(utmp.ut_line, ttyline, sizeof(utmp.ut_line));
991		ftpd_login(&utmp);
992	}
993
994	/* open stats file before chroot */
995	if (guest && (stats == 1) && (statfd < 0))
996		if ((statfd = open(_PATH_FTPDSTATFILE, O_WRONLY|O_APPEND)) < 0)
997			stats = 0;
998
999	logged_in = 1;
1000
1001	if ((dir = login_getcapstr(lc, "ftp-dir", NULL, NULL))) {
1002		char *newdir;
1003
1004		newdir = copy_dir(dir, pw);
1005		if (newdir == NULL) {
1006			perror_reply(421, "Local resource failure: malloc");
1007			dologout(1);
1008			/* NOTREACHED */
1009		}
1010		pw->pw_dir = newdir;
1011		pw = sgetpwnam(NULL, pw);
1012		free(dir);
1013		free(newdir);
1014	}
1015
1016	/* make sure pw->pw_dir is big enough to hold "/" */
1017	sz_pw_dir = strlen(pw->pw_dir) + 1;
1018	if (sz_pw_dir < 2) {
1019		pw->pw_dir = "/";
1020		pw = sgetpwnam(NULL, pw);
1021		sz_pw_dir = 2;
1022	}
1023
1024	if (guest || dochroot) {
1025		if (multihome && guest) {
1026			struct stat ts;
1027
1028			/* Compute root directory. */
1029			snprintf(rootdir, sizeof(rootdir), "%s/%s",
1030			    pw->pw_dir, dhostname);
1031			if (stat(rootdir, &ts) < 0) {
1032				snprintf(rootdir, sizeof(rootdir), "%s/%s",
1033				    pw->pw_dir, hostname);
1034			}
1035		} else
1036			strlcpy(rootdir, pw->pw_dir, sizeof(rootdir));
1037	}
1038	if (guest) {
1039		/*
1040		 * We MUST do a chdir() after the chroot. Otherwise
1041		 * the old current directory will be accessible as "."
1042		 * outside the new root!
1043		 */
1044		if (chroot(rootdir) < 0 || chdir("/") < 0) {
1045			reply(550, "Can't set guest privileges.");
1046			goto bad;
1047		}
1048		strlcpy(pw->pw_dir, "/", sz_pw_dir);
1049		if (setenv("HOME", "/", 1) == -1) {
1050			reply(550, "Can't setup environment.");
1051			goto bad;
1052		}
1053	} else if (dochroot) {
1054		if (chroot(rootdir) < 0 || chdir("/") < 0) {
1055			reply(550, "Can't change root.");
1056			goto bad;
1057		}
1058		strlcpy(pw->pw_dir, "/", sz_pw_dir);
1059		if (setenv("HOME", "/", 1) == -1) {
1060			reply(550, "Can't setup environment.");
1061			goto bad;
1062		}
1063	} else if (chdir(pw->pw_dir) < 0) {
1064		if (chdir("/") < 0) {
1065			reply(530, "User %s: can't change directory to %s.",
1066			    pw->pw_name, pw->pw_dir);
1067			goto bad;
1068		} else
1069			lreply(230, "No directory! Logging in with home=/");
1070	}
1071	if (setegid(pw->pw_gid) < 0 || setgid(pw->pw_gid) < 0) {
1072		reply(550, "Can't set gid.");
1073		goto bad;
1074	}
1075	if (seteuid(pw->pw_uid) < 0 || setuid(pw->pw_uid) < 0) {
1076		reply(550, "Can't set uid.");
1077		goto bad;
1078	}
1079	sigprocmask(SIG_UNBLOCK, &allsigs, NULL);
1080
1081	/*
1082	 * Set home directory so that use of ~ (tilde) works correctly.
1083	 */
1084	if (getcwd(homedir, MAXPATHLEN) != NULL) {
1085		if (setenv("HOME", homedir, 1) == -1) {
1086			reply(550, "Can't setup environment.");
1087			goto bad;
1088		}
1089	}
1090
1091	/*
1092	 * Display a login message, if it exists.
1093	 * N.B. reply(230,) must follow the message.
1094	 */
1095	motd = login_getcapstr(lc, "welcome", NULL, NULL);
1096	if ((fp = fopen(motd ? motd : _PATH_FTPLOGINMESG, "r")) != NULL) {
1097		char line[LINE_MAX];
1098
1099		while (fgets(line, sizeof(line), fp) != NULL) {
1100			line[strcspn(line, "\n")] = '\0';
1101			lreply(230, "%s", line);
1102		}
1103		(void) fflush(stdout);
1104		(void) fclose(fp);
1105	}
1106	if (motd != NULL)
1107		free(motd);
1108	if (guest) {
1109		reply(230, "Guest login ok, access restrictions apply.");
1110#ifdef HASSETPROCTITLE
1111		snprintf(proctitle, sizeof(proctitle),
1112		    "%s: anonymous/%.*s", remotehost,
1113		    (int)(sizeof(proctitle) - sizeof(remotehost) -
1114		    sizeof(": anonymous/")), passwd);
1115		setproctitle("%s", proctitle);
1116#endif /* HASSETPROCTITLE */
1117		if (logging)
1118			syslog(LOG_INFO, "ANONYMOUS FTP LOGIN FROM %s, %s",
1119			    remotehost, passwd);
1120	} else {
1121		reply(230, "User %s logged in.", pw->pw_name);
1122#ifdef HASSETPROCTITLE
1123		snprintf(proctitle, sizeof(proctitle),
1124		    "%s: %s", remotehost, pw->pw_name);
1125		setproctitle("%s", proctitle);
1126#endif /* HASSETPROCTITLE */
1127		if (logging)
1128			syslog(LOG_INFO, "FTP LOGIN FROM %s as %s",
1129			    remotehost, pw->pw_name);
1130	}
1131	login_close(lc);
1132	lc = NULL;
1133	return (AUTH_SLAVE);
1134bad:
1135	/* Forget all about it... */
1136	login_close(lc);
1137	lc = NULL;
1138	end_login();
1139	return (AUTH_FAILED);
1140}
1141
1142void
1143retrieve(char *cmd, char *name)
1144{
1145	FILE *fin, *dout;
1146	struct stat st;
1147	int (*closefunc)(FILE *);
1148	time_t start;
1149
1150	if (cmd == 0) {
1151		fin = fopen(name, "r"), closefunc = fclose;
1152		st.st_size = 0;
1153	} else {
1154		char line[BUFSIZ];
1155
1156		(void) snprintf(line, sizeof(line), cmd, name);
1157		name = line;
1158		fin = ftpd_popen(line, "r"), closefunc = ftpd_pclose;
1159		st.st_size = -1;
1160		st.st_blksize = BUFSIZ;
1161	}
1162	if (fin == NULL) {
1163		if (errno != 0) {
1164			perror_reply(550, name);
1165			if (cmd == 0) {
1166				LOGCMD("get", name);
1167			}
1168		}
1169		return;
1170	}
1171	byte_count = -1;
1172	if (cmd == 0 && (fstat(fileno(fin), &st) < 0 || !S_ISREG(st.st_mode))) {
1173		reply(550, "%s: not a plain file.", name);
1174		goto done;
1175	}
1176	if (restart_point) {
1177		if (type == TYPE_A) {
1178			off_t i, n;
1179			int c;
1180
1181			n = restart_point;
1182			i = 0;
1183			while (i++ < n) {
1184				if ((c = getc(fin)) == EOF) {
1185					if (ferror(fin)) {
1186						perror_reply(550, name);
1187						goto done;
1188					} else
1189						break;
1190				}
1191				if (c == '\n')
1192					i++;
1193			}
1194		} else if (lseek(fileno(fin), restart_point, SEEK_SET) < 0) {
1195			perror_reply(550, name);
1196			goto done;
1197		}
1198	}
1199	dout = dataconn(name, st.st_size, "w");
1200	if (dout == NULL)
1201		goto done;
1202	time(&start);
1203	send_data(fin, dout, (off_t)st.st_blksize, st.st_size,
1204	    (restart_point == 0 && cmd == 0 && S_ISREG(st.st_mode)));
1205	if ((cmd == 0) && stats)
1206		logxfer(name, byte_count, start);
1207	(void) fclose(dout);
1208	data = -1;
1209done:
1210	if (pdata >= 0)
1211		(void) close(pdata);
1212	pdata = -1;
1213	if (cmd == 0)
1214		LOGBYTES("get", name, byte_count);
1215	(*closefunc)(fin);
1216}
1217
1218void
1219store(char *name, char *mode, int unique)
1220{
1221	FILE *fout, *din;
1222	int (*closefunc)(FILE *);
1223	struct stat st;
1224	int fd;
1225
1226	if (restart_point && *mode != 'a')
1227		mode = "r+";
1228
1229	if (unique && stat(name, &st) == 0) {
1230		char *nam;
1231
1232		fd = guniquefd(name, &nam);
1233		if (fd == -1) {
1234			LOGCMD(*mode == 'w' ? "put" : "append", name);
1235			return;
1236		}
1237		name = nam;
1238		fout = fdopen(fd, mode);
1239	} else
1240		fout = fopen(name, mode);
1241
1242	closefunc = fclose;
1243	if (fout == NULL) {
1244		perror_reply(553, name);
1245		LOGCMD(*mode == 'w' ? "put" : "append", name);
1246		return;
1247	}
1248	byte_count = -1;
1249	if (restart_point) {
1250		if (type == TYPE_A) {
1251			off_t i, n;
1252			int c;
1253
1254			n = restart_point;
1255			i = 0;
1256			while (i++ < n) {
1257				if ((c = getc(fout)) == EOF) {
1258					if (ferror(fout)) {
1259						perror_reply(550, name);
1260						goto done;
1261					} else
1262						break;
1263				}
1264				if (c == '\n')
1265					i++;
1266			}
1267			/*
1268			 * We must do this seek to "current" position
1269			 * because we are changing from reading to
1270			 * writing.
1271			 */
1272			if (fseek(fout, 0L, SEEK_CUR) < 0) {
1273				perror_reply(550, name);
1274				goto done;
1275			}
1276		} else if (lseek(fileno(fout), restart_point, SEEK_SET) < 0) {
1277			perror_reply(550, name);
1278			goto done;
1279		}
1280	}
1281	din = dataconn(name, (off_t)-1, "r");
1282	if (din == NULL)
1283		goto done;
1284	if (receive_data(din, fout) == 0) {
1285		if (unique)
1286			reply(226, "Transfer complete (unique file name:%s).",
1287			    name);
1288		else
1289			reply(226, "Transfer complete.");
1290	}
1291	(void) fclose(din);
1292	data = -1;
1293	pdata = -1;
1294done:
1295	LOGBYTES(*mode == 'w' ? "put" : "append", name, byte_count);
1296	(*closefunc)(fout);
1297}
1298
1299static FILE *
1300getdatasock(char *mode)
1301{
1302	int on = 1, s, t, tries;
1303
1304	if (data >= 0)
1305		return (fdopen(data, mode));
1306	sigprocmask (SIG_BLOCK, &allsigs, NULL);
1307	s = monitor_socket(ctrl_addr.su_family);
1308	if (s < 0)
1309		goto bad;
1310	if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
1311	    &on, sizeof(on)) < 0)
1312		goto bad;
1313	/* anchor socket to avoid multi-homing problems */
1314	data_source = ctrl_addr;
1315	data_source.su_port = htons(20); /* ftp-data port */
1316	for (tries = 1; ; tries++) {
1317		if (monitor_bind(s, (struct sockaddr *)&data_source,
1318		    data_source.su_len) >= 0)
1319			break;
1320		if (errno != EADDRINUSE || tries > 10)
1321			goto bad;
1322		sleep((unsigned int)tries);
1323	}
1324	sigprocmask (SIG_UNBLOCK, &allsigs, NULL);
1325
1326#ifdef IP_TOS
1327	if (ctrl_addr.su_family == AF_INET) {
1328		on = IPTOS_THROUGHPUT;
1329		if (setsockopt(s, IPPROTO_IP, IP_TOS, &on,
1330		    sizeof(int)) < 0)
1331			syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
1332	}
1333#endif
1334#ifdef TCP_NOPUSH
1335	/*
1336	 * Turn off push flag to keep sender TCP from sending short packets
1337	 * at the boundaries of each write().  Should probably do a SO_SNDBUF
1338	 * to set the send buffer size as well, but that may not be desirable
1339	 * in heavy-load situations.
1340	 */
1341	on = 1;
1342	if (setsockopt(s, IPPROTO_TCP, TCP_NOPUSH, &on, sizeof(on)) < 0)
1343		syslog(LOG_WARNING, "setsockopt (TCP_NOPUSH): %m");
1344#endif
1345#ifdef SO_SNDBUF
1346	on = 65536;
1347	if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, &on, sizeof(on)) < 0)
1348		syslog(LOG_WARNING, "setsockopt (SO_SNDBUF): %m");
1349#endif
1350
1351	return (fdopen(s, mode));
1352bad:
1353	/* Return the real value of errno (close may change it) */
1354	t = errno;
1355	sigprocmask (SIG_UNBLOCK, &allsigs, NULL);
1356	if (s >= 0)
1357		(void) close(s);
1358	errno = t;
1359	return (NULL);
1360}
1361
1362static FILE *
1363dataconn(char *name, off_t size, char *mode)
1364{
1365	char sizebuf[32];
1366	FILE *file = NULL;
1367	int retry = 0;
1368	in_port_t *p;
1369	u_char *fa, *ha;
1370	size_t alen;
1371	int error;
1372
1373	file_size = size;
1374	byte_count = 0;
1375	if (size != (off_t) -1) {
1376		(void) snprintf(sizebuf, sizeof(sizebuf), " (%qd bytes)",
1377		    size);
1378	} else
1379		sizebuf[0] = '\0';
1380	if (pdata >= 0) {
1381		union sockunion from;
1382		int s;
1383		socklen_t fromlen = sizeof(from);
1384
1385		(void) alarm ((unsigned) timeout);
1386		s = accept(pdata, (struct sockaddr *)&from, &fromlen);
1387		(void) alarm (0);
1388		if (s < 0) {
1389			reply(425, "Can't open data connection.");
1390			(void) close(pdata);
1391			pdata = -1;
1392			return (NULL);
1393		}
1394		switch (from.su_family) {
1395		case AF_INET:
1396			p = (in_port_t *)&from.su_sin.sin_port;
1397			fa = (u_char *)&from.su_sin.sin_addr;
1398			ha = (u_char *)&his_addr.su_sin.sin_addr;
1399			alen = sizeof(struct in_addr);
1400			break;
1401		case AF_INET6:
1402			p = (in_port_t *)&from.su_sin6.sin6_port;
1403			fa = (u_char *)&from.su_sin6.sin6_addr;
1404			ha = (u_char *)&his_addr.su_sin6.sin6_addr;
1405			alen = sizeof(struct in6_addr);
1406			break;
1407		default:
1408			reply(425, "Can't build data connection: "
1409			    "unknown address family");
1410			(void) close(pdata);
1411			(void) close(s);
1412			pdata = -1;
1413			return (NULL);
1414		}
1415		if (from.su_family != his_addr.su_family ||
1416		    ntohs(*p) < IPPORT_RESERVED) {
1417			reply(425, "Can't build data connection: "
1418			    "address family or port error");
1419			(void) close(pdata);
1420			(void) close(s);
1421			pdata = -1;
1422			return (NULL);
1423		}
1424		if (portcheck && memcmp(fa, ha, alen) != 0) {
1425			reply(425, "Can't build data connection: "
1426			    "illegal port number");
1427			(void) close(pdata);
1428			(void) close(s);
1429			pdata = -1;
1430			return (NULL);
1431		}
1432		(void) close(pdata);
1433		pdata = s;
1434		reply(150, "Opening %s mode data connection for '%s'%s.",
1435		    type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1436		return (fdopen(pdata, mode));
1437	}
1438	if (data >= 0) {
1439		reply(125, "Using existing data connection for '%s'%s.",
1440		    name, sizebuf);
1441		usedefault = 1;
1442		return (fdopen(data, mode));
1443	}
1444	if (usedefault)
1445		data_dest = his_addr;
1446	usedefault = 1;
1447	do {
1448		if (file != NULL)
1449			(void) fclose(file);
1450		file = getdatasock(mode);
1451		if (file == NULL) {
1452			char hbuf[MAXHOSTNAMELEN], pbuf[10];
1453
1454			error = getnameinfo((struct sockaddr *)&data_source,
1455			    data_source.su_len, hbuf, sizeof(hbuf), pbuf,
1456			    sizeof(pbuf), NI_NUMERICHOST | NI_NUMERICSERV);
1457			if (error != 0)
1458				reply(425, "Can't create data socket: %s.",
1459				    strerror(errno));
1460			else
1461				reply(425,
1462				    "Can't create data socket (%s,%s): %s.",
1463				    hbuf, pbuf, strerror(errno));
1464			return (NULL);
1465		}
1466
1467		/*
1468		 * attempt to connect to reserved port on client machine;
1469		 * this looks like an attack
1470		 */
1471		switch (data_dest.su_family) {
1472		case AF_INET:
1473			p = (in_port_t *)&data_dest.su_sin.sin_port;
1474			fa = (u_char *)&data_dest.su_sin.sin_addr;
1475			ha = (u_char *)&his_addr.su_sin.sin_addr;
1476			alen = sizeof(struct in_addr);
1477			break;
1478		case AF_INET6:
1479			p = (in_port_t *)&data_dest.su_sin6.sin6_port;
1480			fa = (u_char *)&data_dest.su_sin6.sin6_addr;
1481			ha = (u_char *)&his_addr.su_sin6.sin6_addr;
1482			alen = sizeof(struct in6_addr);
1483			break;
1484		default:
1485			reply(425, "Can't build data connection: "
1486			    "unknown address family");
1487			(void) fclose(file);
1488			pdata = -1;
1489			return (NULL);
1490		}
1491		if (data_dest.su_family != his_addr.su_family ||
1492		    ntohs(*p) < IPPORT_RESERVED || ntohs(*p) == 2049) { /* XXX */
1493			reply(425, "Can't build data connection: "
1494			    "address family or port error");
1495			(void) fclose(file);
1496			return NULL;
1497		}
1498		if (portcheck && memcmp(fa, ha, alen) != 0) {
1499			reply(435, "Can't build data connection: "
1500			    "illegal port number");
1501			(void) fclose(file);
1502			return NULL;
1503		}
1504
1505		if (connect(fileno(file), (struct sockaddr *)&data_dest,
1506		    data_dest.su_len) == 0) {
1507			reply(150, "Opening %s mode data connection for '%s'%s.",
1508			    type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1509			data = fileno(file);
1510			return (file);
1511		}
1512		if (errno != EADDRINUSE)
1513			break;
1514		sleep((unsigned) swaitint);
1515		retry += swaitint;
1516	} while (retry <= swaitmax);
1517	perror_reply(425, "Can't build data connection");
1518	(void) fclose(file);
1519	return (NULL);
1520}
1521
1522/*
1523 * Transfer the contents of "instr" to "outstr" peer using the appropriate
1524 * encapsulation of the data subject to Mode, Structure, and Type.
1525 *
1526 * NB: Form isn't handled.
1527 */
1528static int
1529send_data(FILE *instr, FILE *outstr, off_t blksize, off_t filesize, int isreg)
1530{
1531	int c, cnt, filefd, netfd;
1532	char *buf, *bp;
1533	size_t len;
1534
1535	transflag++;
1536	switch (type) {
1537
1538	case TYPE_A:
1539		while ((c = getc(instr)) != EOF) {
1540			if (recvurg)
1541				goto got_oob;
1542			byte_count++;
1543			if (c == '\n') {
1544				if (ferror(outstr))
1545					goto data_err;
1546				(void) putc('\r', outstr);
1547			}
1548			(void) putc(c, outstr);
1549		}
1550		fflush(outstr);
1551		transflag = 0;
1552		if (ferror(instr))
1553			goto file_err;
1554		if (ferror(outstr))
1555			goto data_err;
1556		reply(226, "Transfer complete.");
1557		return(0);
1558
1559	case TYPE_I:
1560	case TYPE_L:
1561		/*
1562		 * isreg is only set if we are not doing restart and we
1563		 * are sending a regular file
1564		 */
1565		netfd = fileno(outstr);
1566		filefd = fileno(instr);
1567
1568		if (isreg && filesize < (off_t)16 * 1024 * 1024) {
1569			size_t fsize = (size_t)filesize;
1570
1571			buf = mmap(0, fsize, PROT_READ, MAP_SHARED, filefd,
1572			    (off_t)0);
1573			if (buf == MAP_FAILED) {
1574				syslog(LOG_WARNING, "mmap(%llu): %m",
1575				    (unsigned long long)fsize);
1576				goto oldway;
1577			}
1578			bp = buf;
1579			len = fsize;
1580			do {
1581				cnt = write(netfd, bp, len);
1582				if (recvurg) {
1583					munmap(buf, fsize);
1584					goto got_oob;
1585				}
1586				len -= cnt;
1587				bp += cnt;
1588				if (cnt > 0)
1589					byte_count += cnt;
1590			} while(cnt > 0 && len > 0);
1591
1592			transflag = 0;
1593			munmap(buf, fsize);
1594			if (cnt < 0)
1595				goto data_err;
1596			reply(226, "Transfer complete.");
1597			return(0);
1598		}
1599
1600oldway:
1601		if ((buf = malloc((size_t)blksize)) == NULL) {
1602			transflag = 0;
1603			perror_reply(451, "Local resource failure: malloc");
1604			return(-1);
1605		}
1606
1607		while ((cnt = read(filefd, buf, (size_t)blksize)) > 0 &&
1608		    write(netfd, buf, cnt) == cnt)
1609			byte_count += cnt;
1610		transflag = 0;
1611		(void)free(buf);
1612		if (cnt != 0) {
1613			if (cnt < 0)
1614				goto file_err;
1615			goto data_err;
1616		}
1617		reply(226, "Transfer complete.");
1618		return(0);
1619	default:
1620		transflag = 0;
1621		reply(550, "Unimplemented TYPE %d in send_data", type);
1622		return(-1);
1623	}
1624
1625data_err:
1626	transflag = 0;
1627	reply(426, "Data connection");
1628	return(-1);
1629
1630file_err:
1631	transflag = 0;
1632	reply(551, "Error on input file");
1633	return(-1);
1634
1635got_oob:
1636	myoob();
1637	recvurg = 0;
1638	transflag = 0;
1639	return(-1);
1640}
1641
1642/*
1643 * Transfer data from peer to "outstr" using the appropriate encapulation of
1644 * the data subject to Mode, Structure, and Type.
1645 *
1646 * N.B.: Form isn't handled.
1647 */
1648static int
1649receive_data(FILE *instr, FILE *outstr)
1650{
1651	int c;
1652	int cnt;
1653	char buf[BUFSIZ];
1654	struct sigaction sa, sa_saved;
1655	volatile int bare_lfs = 0;
1656
1657	transflag++;
1658	switch (type) {
1659
1660	case TYPE_I:
1661	case TYPE_L:
1662		memset(&sa, 0, sizeof(sa));
1663		sigfillset(&sa.sa_mask);
1664		sa.sa_flags = SA_RESTART;
1665		sa.sa_handler = lostconn;
1666		(void) sigaction(SIGALRM, &sa, &sa_saved);
1667		do {
1668			(void) alarm ((unsigned) timeout);
1669			cnt = read(fileno(instr), buf, sizeof(buf));
1670			(void) alarm (0);
1671			if (recvurg)
1672				goto got_oob;
1673
1674			if (cnt > 0) {
1675				if (write(fileno(outstr), buf, cnt) != cnt)
1676					goto file_err;
1677				byte_count += cnt;
1678			}
1679		} while (cnt > 0);
1680		(void) sigaction(SIGALRM, &sa_saved, NULL);
1681		if (cnt < 0)
1682			goto data_err;
1683		transflag = 0;
1684		return (0);
1685
1686	case TYPE_E:
1687		reply(553, "TYPE E not implemented.");
1688		transflag = 0;
1689		return (-1);
1690
1691	case TYPE_A:
1692		while ((c = getc(instr)) != EOF) {
1693			if (recvurg)
1694				goto got_oob;
1695			byte_count++;
1696			if (c == '\n')
1697				bare_lfs++;
1698			while (c == '\r') {
1699				if (ferror(outstr))
1700					goto data_err;
1701				if ((c = getc(instr)) != '\n') {
1702					(void) putc ('\r', outstr);
1703					if (c == '\0' || c == EOF)
1704						goto contin2;
1705				}
1706			}
1707			(void) putc(c, outstr);
1708	contin2:	;
1709		}
1710		fflush(outstr);
1711		if (ferror(instr))
1712			goto data_err;
1713		if (ferror(outstr))
1714			goto file_err;
1715		transflag = 0;
1716		if (bare_lfs) {
1717			lreply(226,
1718			    "WARNING! %d bare linefeeds received in ASCII mode",
1719			    bare_lfs);
1720			printf("   File may not have transferred correctly.\r\n");
1721		}
1722		return (0);
1723	default:
1724		reply(550, "Unimplemented TYPE %d in receive_data", type);
1725		transflag = 0;
1726		return (-1);
1727	}
1728
1729data_err:
1730	transflag = 0;
1731	reply(426, "Data Connection");
1732	return (-1);
1733
1734file_err:
1735	transflag = 0;
1736	reply(452, "Error writing file");
1737	return (-1);
1738
1739got_oob:
1740	myoob();
1741	recvurg = 0;
1742	transflag = 0;
1743	return (-1);
1744}
1745
1746void
1747statfilecmd(char *filename)
1748{
1749	FILE *fin;
1750	int c;
1751	int atstart;
1752	char line[LINE_MAX];
1753
1754	(void)snprintf(line, sizeof(line), "/bin/ls -lgA %s", filename);
1755	fin = ftpd_popen(line, "r");
1756	if (fin == NULL) {
1757		reply(451, "Local resource failure");
1758		return;
1759	}
1760	lreply(211, "status of %s:", filename);
1761	atstart = 1;
1762	while ((c = getc(fin)) != EOF) {
1763		if (c == '\n') {
1764			if (ferror(stdout)){
1765				perror_reply(421, "control connection");
1766				(void) ftpd_pclose(fin);
1767				dologout(1);
1768				/* NOTREACHED */
1769			}
1770			if (ferror(fin)) {
1771				perror_reply(551, filename);
1772				(void) ftpd_pclose(fin);
1773				return;
1774			}
1775			(void) putc('\r', stdout);
1776		}
1777		if (atstart && isdigit(c))
1778			(void) putc(' ', stdout);
1779		(void) putc(c, stdout);
1780		atstart = (c == '\n');
1781	}
1782	(void) ftpd_pclose(fin);
1783	reply(211, "End of Status");
1784}
1785
1786void
1787statcmd(void)
1788{
1789	union sockunion *su;
1790	u_char *a, *p;
1791	char hbuf[MAXHOSTNAMELEN];
1792	int ispassive;
1793	int error;
1794
1795	lreply(211, "%s FTP server status:", hostname);
1796	error = getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
1797	    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST);
1798	printf("     Connected to %s", remotehost);
1799	if (error == 0 && strcmp(remotehost, hbuf) != 0)
1800		printf(" (%s)", hbuf);
1801	printf("\r\n");
1802	if (logged_in) {
1803		if (guest)
1804			printf("     Logged in anonymously\r\n");
1805		else
1806			printf("     Logged in as %s\r\n", pw->pw_name);
1807	} else if (askpasswd)
1808		printf("     Waiting for password\r\n");
1809	else
1810		printf("     Waiting for user name\r\n");
1811	printf("     TYPE: %s", typenames[type]);
1812	if (type == TYPE_A || type == TYPE_E)
1813		printf(", FORM: %s", formnames[form]);
1814	if (type == TYPE_L)
1815#if NBBY == 8
1816		printf(" %d", NBBY);
1817#else
1818		printf(" %d", bytesize);	/* need definition! */
1819#endif
1820	printf("; STRUcture: %s; transfer MODE: %s\r\n",
1821	    strunames[stru], modenames[mode]);
1822	ispassive = 0;
1823	if (data != -1)
1824		printf("     Data connection open\r\n");
1825	else if (pdata != -1) {
1826		printf("     in Passive mode\r\n");
1827		su = (union sockunion *)&pasv_addr;
1828		ispassive++;
1829		goto printaddr;
1830	} else if (usedefault == 0) {
1831		size_t alen;
1832		int af, i;
1833
1834		su = (union sockunion *)&data_dest;
1835printaddr:
1836		/* PASV/PORT */
1837		if (su->su_family == AF_INET) {
1838			if (ispassive)
1839				printf("211- PASV ");
1840			else
1841				printf("211- PORT ");
1842			a = (u_char *)&su->su_sin.sin_addr;
1843			p = (u_char *)&su->su_sin.sin_port;
1844			printf("(%u,%u,%u,%u,%u,%u)\r\n",
1845			    a[0], a[1], a[2], a[3],
1846			    p[0], p[1]);
1847		}
1848
1849		/* LPSV/LPRT */
1850		alen = 0;
1851		switch (su->su_family) {
1852		case AF_INET:
1853			a = (u_char *)&su->su_sin.sin_addr;
1854			p = (u_char *)&su->su_sin.sin_port;
1855			alen = sizeof(su->su_sin.sin_addr);
1856			af = 4;
1857			break;
1858		case AF_INET6:
1859			a = (u_char *)&su->su_sin6.sin6_addr;
1860			p = (u_char *)&su->su_sin6.sin6_port;
1861			alen = sizeof(su->su_sin6.sin6_addr);
1862			af = 6;
1863			break;
1864		default:
1865			af = 0;
1866			break;
1867		}
1868		if (af) {
1869			if (ispassive)
1870				printf("211- LPSV ");
1871			else
1872				printf("211- LPRT ");
1873			printf("(%u,%llu", af, (unsigned long long)alen);
1874			for (i = 0; i < alen; i++)
1875				printf(",%u", a[i]);
1876			printf(",%u,%u,%u)\r\n", 2, p[0], p[1]);
1877		}
1878
1879		/* EPRT/EPSV */
1880		switch (su->su_family) {
1881		case AF_INET:
1882			af = 1;
1883			break;
1884		case AF_INET6:
1885			af = 2;
1886			break;
1887		default:
1888			af = 0;
1889			break;
1890		}
1891		if (af) {
1892			char pbuf[10];
1893			union sockunion tmp = *su;
1894
1895			if (tmp.su_family == AF_INET6)
1896				tmp.su_sin6.sin6_scope_id = 0;
1897			if (getnameinfo((struct sockaddr *)&tmp, tmp.su_len,
1898			    hbuf, sizeof(hbuf), pbuf, sizeof(pbuf),
1899			    NI_NUMERICHOST | NI_NUMERICSERV) == 0) {
1900				if (ispassive)
1901					printf("211- EPSV ");
1902				else
1903					printf("211- EPRT ");
1904				printf("(|%u|%s|%s|)\r\n",
1905				    af, hbuf, pbuf);
1906			}
1907		}
1908	} else
1909		printf("     No data connection\r\n");
1910	reply(211, "End of status");
1911}
1912
1913void
1914fatal(char *s)
1915{
1916
1917	reply(451, "Error in server: %s", s);
1918	reply(221, "Closing connection due to server error.");
1919	dologout(0);
1920	/* NOTREACHED */
1921}
1922
1923void
1924reply(int n, const char *fmt, ...)
1925{
1926	char *buf, *p, *next;
1927	int rval;
1928	va_list ap;
1929
1930	va_start(ap, fmt);
1931	rval = vasprintf(&buf, fmt, ap);
1932	va_end(ap);
1933	if (rval == -1 || buf == NULL) {
1934		printf("421 Local resource failure: malloc\r\n");
1935		fflush(stdout);
1936		dologout(1);
1937	}
1938	next = buf;
1939	while ((p = strsep(&next, "\n\r"))) {
1940		printf("%d%s %s\r\n", n, (next != '\0') ? "-" : "", p);
1941		if (debug)
1942			syslog(LOG_DEBUG, "<--- %d%s %s", n,
1943			    (next != '\0') ? "-" : "", p);
1944	}
1945	(void)fflush(stdout);
1946	free(buf);
1947}
1948
1949
1950void
1951reply_r(int n, const char *fmt, ...)
1952{
1953	char *p, *next;
1954	char msg[BUFSIZ];
1955	char buf[BUFSIZ];
1956	va_list ap;
1957	struct syslog_data sdata = SYSLOG_DATA_INIT;
1958
1959	sdata.log_fac = LOG_FTP;
1960	va_start(ap, fmt);
1961	vsnprintf(msg, sizeof(msg), fmt, ap);
1962	va_end(ap);
1963
1964	next = msg;
1965
1966	while ((p = strsep(&next, "\n\r"))) {
1967		snprintf(buf, sizeof(buf), "%d%s %s\r\n", n,
1968		    (next != '\0') ? "-" : "", p);
1969		write(STDOUT_FILENO, buf, strlen(buf));
1970		if (debug) {
1971			buf[strlen(buf) - 2] = '\0';
1972			syslog_r(LOG_DEBUG, &sdata, "<--- %s", buf);
1973		}
1974	}
1975}
1976
1977void
1978lreply(int n, const char *fmt, ...)
1979{
1980	va_list ap;
1981
1982	va_start(ap, fmt);
1983	(void)printf("%d- ", n);
1984	(void)vprintf(fmt, ap);
1985	va_end(ap);
1986	(void)printf("\r\n");
1987	(void)fflush(stdout);
1988	if (debug) {
1989		va_start(ap, fmt);
1990		syslog(LOG_DEBUG, "<--- %d- ", n);
1991		vsyslog(LOG_DEBUG, fmt, ap);
1992		va_end(ap);
1993	}
1994}
1995
1996static void
1997ack(char *s)
1998{
1999
2000	reply(250, "%s command successful.", s);
2001}
2002
2003void
2004nack(char *s)
2005{
2006
2007	reply(502, "%s command not implemented.", s);
2008}
2009
2010/* ARGSUSED */
2011void
2012yyerror(char *s)
2013{
2014	cbuf[strcspn(cbuf, "\n")] = '\0';
2015	reply(500, "'%s': command not understood.", cbuf);
2016}
2017
2018void
2019delete(char *name)
2020{
2021	struct stat st;
2022
2023	LOGCMD("delete", name);
2024	if (stat(name, &st) < 0) {
2025		perror_reply(550, name);
2026		return;
2027	}
2028	if ((st.st_mode&S_IFMT) == S_IFDIR) {
2029		if (rmdir(name) < 0) {
2030			perror_reply(550, name);
2031			return;
2032		}
2033		goto done;
2034	}
2035	if (unlink(name) < 0) {
2036		perror_reply(550, name);
2037		return;
2038	}
2039done:
2040	ack("DELE");
2041}
2042
2043void
2044cwd(char *path)
2045{
2046	FILE *message;
2047
2048	if (chdir(path) < 0)
2049		perror_reply(550, path);
2050	else {
2051		if ((message = fopen(_PATH_CWDMESG, "r")) != NULL) {
2052			char line[LINE_MAX];
2053
2054			while (fgets(line, sizeof(line), message) != NULL) {
2055				line[strcspn(line, "\n")] = '\0';
2056				lreply(250, "%s", line);
2057			}
2058			(void) fflush(stdout);
2059			(void) fclose(message);
2060		}
2061		ack("CWD");
2062	}
2063}
2064
2065void
2066replydirname(const char *name, const char *message)
2067{
2068	char *p, *ep;
2069	char npath[MAXPATHLEN * 2];
2070
2071	p = npath;
2072	ep = &npath[sizeof(npath) - 1];
2073	while (*name) {
2074		if (*name == '"') {
2075			if (ep - p < 2)
2076				break;
2077			*p++ = *name++;
2078			*p++ = '"';
2079		} else {
2080			if (ep - p < 1)
2081				break;
2082			*p++ = *name++;
2083		}
2084	}
2085	*p = '\0';
2086	reply(257, "\"%s\" %s", npath, message);
2087}
2088
2089void
2090makedir(char *name)
2091{
2092
2093	LOGCMD("mkdir", name);
2094	if (mkdir(name, 0777) < 0)
2095		perror_reply(550, name);
2096	else
2097		replydirname(name, "directory created.");
2098}
2099
2100void
2101removedir(char *name)
2102{
2103
2104	LOGCMD("rmdir", name);
2105	if (rmdir(name) < 0)
2106		perror_reply(550, name);
2107	else
2108		ack("RMD");
2109}
2110
2111void
2112pwd(void)
2113{
2114	char path[MAXPATHLEN];
2115
2116	if (getcwd(path, sizeof(path)) == NULL)
2117		perror_reply(550, "Can't get current directory");
2118	else
2119		replydirname(path, "is current directory.");
2120}
2121
2122char *
2123renamefrom(char *name)
2124{
2125	struct stat st;
2126
2127	if (stat(name, &st) < 0) {
2128		perror_reply(550, name);
2129		return ((char *)0);
2130	}
2131	reply(350, "File exists, ready for destination name");
2132	return (name);
2133}
2134
2135void
2136renamecmd(char *from, char *to)
2137{
2138
2139	LOGCMD2("rename", from, to);
2140	if (rename(from, to) < 0)
2141		perror_reply(550, "rename");
2142	else
2143		ack("RNTO");
2144}
2145
2146static void
2147dolog(struct sockaddr *sa)
2148{
2149	char hbuf[sizeof(remotehost)];
2150
2151	if (getnameinfo(sa, sa->sa_len, hbuf, sizeof(hbuf), NULL, 0, 0) == 0)
2152		(void) strlcpy(remotehost, hbuf, sizeof(remotehost));
2153	else
2154		(void) strlcpy(remotehost, "unknown", sizeof(remotehost));
2155
2156#ifdef HASSETPROCTITLE
2157	snprintf(proctitle, sizeof(proctitle), "%s: connected", remotehost);
2158	setproctitle("%s", proctitle);
2159#endif /* HASSETPROCTITLE */
2160
2161	if (logging) {
2162		int error;
2163		error = getnameinfo(sa, sa->sa_len, hbuf, sizeof(hbuf),
2164		    NULL, 0, NI_NUMERICHOST);
2165		syslog(LOG_INFO, "connection from %s [%s]", remotehost,
2166		    error ? gai_strerror(error) : hbuf);
2167	}
2168}
2169
2170/*
2171 * Record logout in wtmp file and exit with supplied status.
2172 * NOTE: because this is called from signal handlers it cannot
2173 *       use stdio (or call other functions that use stdio).
2174 */
2175void
2176dologout(int status)
2177{
2178
2179	transflag = 0;
2180
2181	if (logged_in) {
2182		sigprocmask(SIG_BLOCK, &allsigs, NULL);
2183		ftpdlogwtmp(ttyline, "", "");
2184		if (doutmp)
2185			ftpd_logout(utmp.ut_line);
2186	}
2187	/* beware of flushing buffers after a SIGPIPE */
2188	_exit(status);
2189}
2190
2191/*ARGSUSED*/
2192static void
2193sigurg(int signo)
2194{
2195
2196	recvurg = 1;
2197}
2198
2199static void
2200myoob(void)
2201{
2202	char *cp;
2203	int ret;
2204
2205	/* only process if transfer occurring */
2206	if (!transflag)
2207		return;
2208	cp = tmpline;
2209	ret = getline(cp, 7, stdin);
2210	if (ret == -1) {
2211		reply(221, "You could at least say goodbye.");
2212		dologout(0);
2213	} else if (ret == -2) {
2214		/* Ignore truncated command */
2215		return;
2216	}
2217	upper(cp);
2218	if (strcmp(cp, "ABOR\r\n") == 0) {
2219		tmpline[0] = '\0';
2220		reply(426, "Transfer aborted. Data connection closed.");
2221		reply(226, "Abort successful");
2222	}
2223	if (strcmp(cp, "STAT\r\n") == 0) {
2224		tmpline[0] = '\0';
2225		if (file_size != (off_t) -1)
2226			reply(213, "Status: %qd of %qd bytes transferred",
2227			    byte_count, file_size);
2228		else
2229			reply(213, "Status: %qd bytes transferred", byte_count);
2230	}
2231}
2232
2233/*
2234 * Note: a response of 425 is not mentioned as a possible response to
2235 *	the PASV command in RFC959. However, it has been blessed as
2236 *	a legitimate response by Jon Postel in a telephone conversation
2237 *	with Rick Adams on 25 Jan 89.
2238 */
2239void
2240passive(void)
2241{
2242	socklen_t len;
2243	int on;
2244	u_char *p, *a;
2245
2246	if (pw == NULL) {
2247		reply(530, "Please login with USER and PASS");
2248		return;
2249	}
2250	if (pdata >= 0)
2251		close(pdata);
2252	/*
2253	 * XXX
2254	 * At this point, it would be nice to have an algorithm that
2255	 * inserted a growing delay in an attack scenario.  Such a thing
2256	 * would look like continual passive sockets being opened, but
2257	 * nothing serious being done with them.  They're not used to
2258	 * move data; the entire attempt is just to use tcp FIN_WAIT
2259	 * resources.
2260	 */
2261	pdata = socket(AF_INET, SOCK_STREAM, 0);
2262	if (pdata < 0) {
2263		perror_reply(425, "Can't open passive connection");
2264		return;
2265	}
2266
2267	on = IP_PORTRANGE_HIGH;
2268	if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2269	    &on, sizeof(on)) < 0)
2270		goto pasv_error;
2271
2272	pasv_addr = ctrl_addr;
2273	pasv_addr.su_sin.sin_port = 0;
2274	if (bind(pdata, (struct sockaddr *)&pasv_addr,
2275	    pasv_addr.su_len) < 0)
2276		goto pasv_error;
2277
2278	len = sizeof(pasv_addr);
2279	if (getsockname(pdata, (struct sockaddr *)&pasv_addr, &len) < 0)
2280		goto pasv_error;
2281	if (listen(pdata, 1) < 0)
2282		goto pasv_error;
2283	a = (u_char *)&pasv_addr.su_sin.sin_addr;
2284	p = (u_char *)&pasv_addr.su_sin.sin_port;
2285
2286	reply(227, "Entering Passive Mode (%u,%u,%u,%u,%u,%u)", a[0],
2287	    a[1], a[2], a[3], p[0], p[1]);
2288	return;
2289
2290pasv_error:
2291	perror_reply(425, "Can't open passive connection");
2292	(void) close(pdata);
2293	pdata = -1;
2294	return;
2295}
2296
2297int
2298epsvproto2af(int proto)
2299{
2300
2301	switch (proto) {
2302	case 1:	return AF_INET;
2303#ifdef INET6
2304	case 2:	return AF_INET6;
2305#endif
2306	default: return -1;
2307	}
2308}
2309
2310int
2311af2epsvproto(int af)
2312{
2313
2314	switch (af) {
2315	case AF_INET:	return 1;
2316#ifdef INET6
2317	case AF_INET6:	return 2;
2318#endif
2319	default:	return -1;
2320	}
2321}
2322
2323/*
2324 * 228 Entering Long Passive Mode (af, hal, h1, h2, h3,..., pal, p1, p2...)
2325 * 229 Entering Extended Passive Mode (|||port|)
2326 */
2327void
2328long_passive(char *cmd, int pf)
2329{
2330	socklen_t len;
2331	int on;
2332	u_char *p, *a;
2333
2334	if (!logged_in) {
2335		syslog(LOG_NOTICE, "long passive but not logged in");
2336		reply(503, "Login with USER first.");
2337		return;
2338	}
2339
2340	if (pf != PF_UNSPEC && ctrl_addr.su_family != pf) {
2341		/*
2342		 * XXX
2343		 * only EPRT/EPSV ready clients will understand this
2344		 */
2345		if (strcmp(cmd, "EPSV") != 0)
2346			reply(501, "Network protocol mismatch"); /*XXX*/
2347		else
2348			epsv_protounsupp("Network protocol mismatch");
2349
2350		return;
2351	}
2352
2353	if (pdata >= 0)
2354		close(pdata);
2355	/*
2356	 * XXX
2357	 * At this point, it would be nice to have an algorithm that
2358	 * inserted a growing delay in an attack scenario.  Such a thing
2359	 * would look like continual passive sockets being opened, but
2360	 * nothing serious being done with them.  They not used to move
2361	 * data; the entire attempt is just to use tcp FIN_WAIT
2362	 * resources.
2363	 */
2364	pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2365	if (pdata < 0) {
2366		perror_reply(425, "Can't open passive connection");
2367		return;
2368	}
2369
2370	switch (ctrl_addr.su_family) {
2371	case AF_INET:
2372		on = IP_PORTRANGE_HIGH;
2373		if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2374		    &on, sizeof(on)) < 0)
2375			goto pasv_error;
2376		break;
2377	case AF_INET6:
2378		on = IPV6_PORTRANGE_HIGH;
2379		if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2380		    &on, sizeof(on)) < 0)
2381			goto pasv_error;
2382		break;
2383	}
2384
2385	pasv_addr = ctrl_addr;
2386	pasv_addr.su_port = 0;
2387	if (bind(pdata, (struct sockaddr *)&pasv_addr, pasv_addr.su_len) < 0)
2388		goto pasv_error;
2389	len = pasv_addr.su_len;
2390	if (getsockname(pdata, (struct sockaddr *)&pasv_addr, &len) < 0)
2391		goto pasv_error;
2392	if (listen(pdata, 1) < 0)
2393		goto pasv_error;
2394	p = (u_char *)&pasv_addr.su_port;
2395
2396	if (strcmp(cmd, "LPSV") == 0) {
2397		switch (pasv_addr.su_family) {
2398		case AF_INET:
2399			a = (u_char *)&pasv_addr.su_sin.sin_addr;
2400			reply(228,
2401			    "Entering Long Passive Mode (%u,%u,%u,%u,%u,%u,%u,%u,%u)",
2402			    4, 4, a[0], a[1], a[2], a[3], 2, p[0], p[1]);
2403			return;
2404		case AF_INET6:
2405			a = (u_char *)&pasv_addr.su_sin6.sin6_addr;
2406			reply(228,
2407			    "Entering Long Passive Mode (%u,%u,%u,%u,%u,%u,"
2408			    "%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u)",
2409				6, 16, a[0], a[1], a[2], a[3], a[4],
2410				a[5], a[6], a[7], a[8], a[9], a[10],
2411				a[11], a[12], a[13], a[14], a[15],
2412				2, p[0], p[1]);
2413			return;
2414		}
2415	} else if (strcmp(cmd, "EPSV") == 0) {
2416		switch (pasv_addr.su_family) {
2417		case AF_INET:
2418		case AF_INET6:
2419			reply(229, "Entering Extended Passive Mode (|||%u|)",
2420			    ntohs(pasv_addr.su_port));
2421			return;
2422		}
2423	} else {
2424		/* more proper error code? */
2425	}
2426
2427  pasv_error:
2428	perror_reply(425, "Can't open passive connection");
2429	(void) close(pdata);
2430	pdata = -1;
2431	return;
2432}
2433
2434/*
2435 * EPRT |proto|addr|port|
2436 */
2437int
2438extended_port(const char *arg)
2439{
2440	char *tmp = NULL;
2441	char *result[3];
2442	char *p, *q;
2443	char delim;
2444	struct addrinfo hints;
2445	struct addrinfo *res = NULL;
2446	int i;
2447	unsigned long proto;
2448
2449	if (epsvall) {
2450		reply(501, "EPRT disallowed after EPSV ALL");
2451		return -1;
2452	}
2453
2454	usedefault = 0;
2455	if (pdata >= 0) {
2456		(void) close(pdata);
2457		pdata = -1;
2458	}
2459
2460	tmp = strdup(arg);
2461	if (!tmp) {
2462		fatal("not enough core.");
2463		/*NOTREACHED*/
2464	}
2465	p = tmp;
2466	delim = p[0];
2467	p++;
2468	memset(result, 0, sizeof(result));
2469	for (i = 0; i < 3; i++) {
2470		q = strchr(p, delim);
2471		if (!q || *q != delim)
2472			goto parsefail;
2473		*q++ = '\0';
2474		result[i] = p;
2475		p = q;
2476	}
2477
2478	/* some more sanity check */
2479	p = NULL;
2480	(void)strtoul(result[2], &p, 10);
2481	if (!*result[2] || *p)
2482		goto protounsupp;
2483	p = NULL;
2484	proto = strtoul(result[0], &p, 10);
2485	if (!*result[0] || *p)
2486		goto protounsupp;
2487
2488	memset(&hints, 0, sizeof(hints));
2489	hints.ai_family = epsvproto2af((int)proto);
2490	if (hints.ai_family < 0)
2491		goto protounsupp;
2492	hints.ai_socktype = SOCK_STREAM;
2493	hints.ai_flags = AI_NUMERICHOST;	/*no DNS*/
2494	if (getaddrinfo(result[1], result[2], &hints, &res))
2495		goto parsefail;
2496	if (res->ai_next)
2497		goto parsefail;
2498	if (sizeof(data_dest) < res->ai_addrlen)
2499		goto parsefail;
2500	memcpy(&data_dest, res->ai_addr, res->ai_addrlen);
2501	if (his_addr.su_family == AF_INET6 &&
2502	    data_dest.su_family == AF_INET6) {
2503		/* XXX more sanity checks! */
2504		data_dest.su_sin6.sin6_scope_id =
2505		    his_addr.su_sin6.sin6_scope_id;
2506	}
2507	if (pdata >= 0) {
2508		(void) close(pdata);
2509		pdata = -1;
2510	}
2511	reply(200, "EPRT command successful.");
2512
2513	if (tmp)
2514		free(tmp);
2515	if (res)
2516		freeaddrinfo(res);
2517	return 0;
2518
2519parsefail:
2520	reply(500, "Invalid argument, rejected.");
2521	usedefault = 1;
2522	if (tmp)
2523		free(tmp);
2524	if (res)
2525		freeaddrinfo(res);
2526	return -1;
2527
2528protounsupp:
2529	epsv_protounsupp("Protocol not supported");
2530	usedefault = 1;
2531	if (tmp)
2532		free(tmp);
2533	if (res)
2534		freeaddrinfo(res);
2535	return -1;
2536}
2537
2538/*
2539 * 522 Protocol not supported (proto,...)
2540 * as we assume address family for control and data connections are the same,
2541 * we do not return the list of address families we support - instead, we
2542 * return the address family of the control connection.
2543 */
2544void
2545epsv_protounsupp(const char *message)
2546{
2547	int proto;
2548
2549	proto = af2epsvproto(ctrl_addr.su_family);
2550	if (proto < 0)
2551		reply(501, "%s", message);	/*XXX*/
2552	else
2553		reply(522, "%s, use (%d)", message, proto);
2554}
2555
2556/*
2557 * Generate unique name for file with basename "local".
2558 * The file named "local" is already known to exist.
2559 * Generates failure reply on error.
2560 */
2561static int
2562guniquefd(char *local, char **nam)
2563{
2564	static char new[MAXPATHLEN];
2565	struct stat st;
2566	int count, len, fd;
2567	char *cp;
2568
2569	cp = strrchr(local, '/');
2570	if (cp)
2571		*cp = '\0';
2572	if (stat(cp ? local : ".", &st) < 0) {
2573		perror_reply(553, cp ? local : ".");
2574		return (-1);
2575	}
2576	if (cp)
2577		*cp = '/';
2578	len = strlcpy(new, local, sizeof(new));
2579	if (len+2+1 >= sizeof(new)-1)
2580		return (-1);
2581	cp = new + len;
2582	*cp++ = '.';
2583	for (count = 1; count < 100; count++) {
2584		(void)snprintf(cp, sizeof(new) - (cp - new), "%d", count);
2585		fd = open(new, O_RDWR|O_CREAT|O_EXCL, 0666);
2586		if (fd == -1)
2587			continue;
2588		if (nam)
2589			*nam = new;
2590		return (fd);
2591	}
2592	reply(452, "Unique file name cannot be created.");
2593	return (-1);
2594}
2595
2596/*
2597 * Format and send reply containing system error number.
2598 */
2599void
2600perror_reply(int code, char *string)
2601{
2602
2603	reply(code, "%s: %s.", string, strerror(errno));
2604}
2605
2606static char *onefile[] = {
2607	"",
2608	0
2609};
2610
2611void
2612send_file_list(char *whichf)
2613{
2614	struct stat st;
2615	DIR *dirp = NULL;
2616	struct dirent *dir;
2617	FILE *dout = NULL;
2618	char **dirlist;
2619	char *dirname;
2620	int simple = 0;
2621	volatile int freeglob = 0;
2622	glob_t gl;
2623
2624	if (strpbrk(whichf, "~{[*?") != NULL) {
2625		memset(&gl, 0, sizeof(gl));
2626		freeglob = 1;
2627		if (glob(whichf,
2628		    GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE|GLOB_LIMIT,
2629		    0, &gl)) {
2630			reply(550, "not found");
2631			goto out;
2632		} else if (gl.gl_pathc == 0) {
2633			errno = ENOENT;
2634			perror_reply(550, whichf);
2635			goto out;
2636		}
2637		dirlist = gl.gl_pathv;
2638	} else {
2639		onefile[0] = whichf;
2640		dirlist = onefile;
2641		simple = 1;
2642	}
2643
2644	while ((dirname = *dirlist++)) {
2645		if (stat(dirname, &st) < 0) {
2646			/*
2647			 * If user typed "ls -l", etc, and the client
2648			 * used NLST, do what the user meant.
2649			 */
2650			if (dirname[0] == '-' && *dirlist == NULL &&
2651			    transflag == 0) {
2652				retrieve("/bin/ls %s", dirname);
2653				goto out;
2654			}
2655			perror_reply(550, whichf);
2656			if (dout != NULL) {
2657				(void) fclose(dout);
2658				transflag = 0;
2659				data = -1;
2660				pdata = -1;
2661			}
2662			goto out;
2663		}
2664
2665		if (S_ISREG(st.st_mode)) {
2666			if (dout == NULL) {
2667				dout = dataconn("file list", (off_t)-1, "w");
2668				if (dout == NULL)
2669					goto out;
2670				transflag++;
2671			}
2672			fprintf(dout, "%s%s\n", dirname,
2673				type == TYPE_A ? "\r" : "");
2674			byte_count += strlen(dirname) + 1;
2675			continue;
2676		} else if (!S_ISDIR(st.st_mode))
2677			continue;
2678
2679		if ((dirp = opendir(dirname)) == NULL)
2680			continue;
2681
2682		while ((dir = readdir(dirp)) != NULL) {
2683			char nbuf[MAXPATHLEN];
2684
2685			if (recvurg) {
2686				myoob();
2687				recvurg = 0;
2688				transflag = 0;
2689				goto out;
2690			}
2691
2692			if (dir->d_name[0] == '.' && dir->d_namlen == 1)
2693				continue;
2694			if (dir->d_name[0] == '.' && dir->d_name[1] == '.' &&
2695			    dir->d_namlen == 2)
2696				continue;
2697
2698			snprintf(nbuf, sizeof(nbuf), "%s/%s", dirname,
2699				 dir->d_name);
2700
2701			/*
2702			 * We have to do a stat to insure it's
2703			 * not a directory or special file.
2704			 */
2705			if (simple || (stat(nbuf, &st) == 0 &&
2706			    S_ISREG(st.st_mode))) {
2707				if (dout == NULL) {
2708					dout = dataconn("file list", (off_t)-1,
2709						"w");
2710					if (dout == NULL)
2711						goto out;
2712					transflag++;
2713				}
2714				if (nbuf[0] == '.' && nbuf[1] == '/')
2715					fprintf(dout, "%s%s\n", &nbuf[2],
2716						type == TYPE_A ? "\r" : "");
2717				else
2718					fprintf(dout, "%s%s\n", nbuf,
2719						type == TYPE_A ? "\r" : "");
2720				byte_count += strlen(nbuf) + 1;
2721			}
2722		}
2723		(void) closedir(dirp);
2724	}
2725
2726	if (dout == NULL)
2727		reply(550, "No files found.");
2728	else if (ferror(dout) != 0)
2729		perror_reply(550, "Data connection");
2730	else
2731		reply(226, "Transfer complete.");
2732
2733	transflag = 0;
2734	if (dout != NULL)
2735		(void) fclose(dout);
2736	else {
2737		if (pdata >= 0)
2738			close(pdata);
2739	}
2740	data = -1;
2741	pdata = -1;
2742out:
2743	if (freeglob) {
2744		freeglob = 0;
2745		globfree(&gl);
2746	}
2747}
2748
2749/*ARGSUSED*/
2750static void
2751reapchild(int signo)
2752{
2753	int save_errno = errno;
2754	int rval;
2755
2756	do {
2757		rval = waitpid(-1, NULL, WNOHANG);
2758	} while (rval > 0 || (rval == -1 && errno == EINTR));
2759	errno = save_errno;
2760}
2761
2762void
2763logxfer(char *name, off_t size, time_t start)
2764{
2765	char buf[400 + MAXHOSTNAMELEN*4 + MAXPATHLEN*4];
2766	char dir[MAXPATHLEN], path[MAXPATHLEN], rpath[MAXPATHLEN];
2767	char vremotehost[MAXHOSTNAMELEN*4], vpath[MAXPATHLEN*4];
2768	char *vpw;
2769	time_t now;
2770	int len;
2771
2772	if ((statfd >= 0) && (getcwd(dir, sizeof(dir)) != NULL)) {
2773		time(&now);
2774
2775		vpw = malloc(strlen(guest ? guestpw : pw->pw_name) * 4 + 1);
2776		if (vpw == NULL)
2777			return;
2778
2779		snprintf(path, sizeof(path), "%s/%s", dir, name);
2780		if (realpath(path, rpath) == NULL)
2781			strlcpy(rpath, path, sizeof(rpath));
2782		strvis(vpath, rpath, VIS_SAFE|VIS_NOSLASH);
2783
2784		strvis(vremotehost, remotehost, VIS_SAFE|VIS_NOSLASH);
2785		strvis(vpw, guest? guestpw : pw->pw_name, VIS_SAFE|VIS_NOSLASH);
2786
2787		len = snprintf(buf, sizeof(buf),
2788		    "%.24s %d %s %qd %s %c %s %c %c %s ftp %d %s %s\n",
2789		    ctime(&now), now - start + (now == start),
2790		    vremotehost, (long long)size, vpath,
2791		    ((type == TYPE_A) ? 'a' : 'b'), "*" /* none yet */,
2792		    'o', ((guest) ? 'a' : 'r'),
2793		    vpw, 0 /* none yet */,
2794		    ((guest) ? "*" : pw->pw_name), dhostname);
2795		free(vpw);
2796
2797		if (len >= sizeof(buf) || len == -1) {
2798			if ((len = strlen(buf)) == 0)
2799				return;		/* should not happen */
2800			buf[len - 1] = '\n';
2801		}
2802		write(statfd, buf, len);
2803	}
2804}
2805
2806void
2807set_slave_signals(void)
2808{
2809	struct sigaction sa;
2810
2811	sigemptyset(&sa.sa_mask);
2812	sa.sa_flags = SA_RESTART;
2813
2814	sa.sa_handler = SIG_DFL;
2815	(void) sigaction(SIGCHLD, &sa, NULL);
2816
2817	sa.sa_handler = sigurg;
2818	sa.sa_flags = 0;		/* don't restart syscalls for SIGURG */
2819	(void) sigaction(SIGURG, &sa, NULL);
2820
2821	sigfillset(&sa.sa_mask);	/* block all signals in handler */
2822	sa.sa_flags = SA_RESTART;
2823	sa.sa_handler = sigquit;
2824	(void) sigaction(SIGHUP, &sa, NULL);
2825	(void) sigaction(SIGINT, &sa, NULL);
2826	(void) sigaction(SIGQUIT, &sa, NULL);
2827	(void) sigaction(SIGTERM, &sa, NULL);
2828
2829	sa.sa_handler = lostconn;
2830	(void) sigaction(SIGPIPE, &sa, NULL);
2831
2832	sa.sa_handler = toolong;
2833	(void) sigaction(SIGALRM, &sa, NULL);
2834
2835#ifdef F_SETOWN
2836	if (fcntl(fileno(stdin), F_SETOWN, getpid()) == -1)
2837		syslog(LOG_ERR, "fcntl F_SETOWN: %m");
2838#endif
2839}
2840
2841#if defined(TCPWRAPPERS)
2842static int
2843check_host(struct sockaddr *sa)
2844{
2845	struct sockaddr_in *sin;
2846	struct hostent *hp;
2847	char *addr;
2848
2849	if (sa->sa_family != AF_INET)
2850		return 1;	/*XXX*/
2851
2852	sin = (struct sockaddr_in *)sa;
2853	hp = gethostbyaddr((char *)&sin->sin_addr,
2854	    sizeof(struct in_addr), AF_INET);
2855	addr = inet_ntoa(sin->sin_addr);
2856	if (hp) {
2857		if (!hosts_ctl("ftpd", hp->h_name, addr, STRING_UNKNOWN)) {
2858			syslog(LOG_NOTICE, "tcpwrappers rejected: %s [%s]",
2859			    hp->h_name, addr);
2860			return (0);
2861		}
2862	} else {
2863		if (!hosts_ctl("ftpd", STRING_UNKNOWN, addr, STRING_UNKNOWN)) {
2864			syslog(LOG_NOTICE, "tcpwrappers rejected: [%s]", addr);
2865			return (0);
2866		}
2867	}
2868	return (1);
2869}
2870#endif	/* TCPWRAPPERS */
2871
2872/*
2873 * Allocate space and return a copy of the specified dir.
2874 * If 'dir' begins with a tilde (~), expand it.
2875 */
2876char *
2877copy_dir(char *dir, struct passwd *pw)
2878{
2879	char *cp;
2880	char *newdir;
2881	char *user = NULL;
2882
2883	/* Nothing to expand */
2884	if (dir[0] != '~')
2885		return (strdup(dir));
2886
2887	/* "dir" is of form ~user/some/dir, lookup user. */
2888	if (dir[1] != '/' && dir[1] != '\0') {
2889		if ((cp = strchr(dir + 1, '/')) == NULL)
2890			cp = dir + strlen(dir);
2891		if ((user = malloc((size_t)(cp - dir))) == NULL)
2892			return (NULL);
2893		strlcpy(user, dir + 1, (size_t)(cp - dir));
2894
2895		/* Only do lookup if it is a different user. */
2896		if (strcmp(user, pw->pw_name) != 0) {
2897			if ((pw = getpwnam(user)) == NULL) {
2898				/* No such user, interpret literally */
2899				free(user);
2900				return(strdup(dir));
2901			}
2902		}
2903		free(user);
2904	}
2905
2906	/*
2907	 * If there is no directory separator (/) then it is just pw_dir.
2908	 * Otherwise, replace ~foo with pw_dir.
2909	 */
2910	if ((cp = strchr(dir + 1, '/')) == NULL) {
2911		newdir = strdup(pw->pw_dir);
2912	} else {
2913		if (asprintf(&newdir, "%s%s", pw->pw_dir, cp) == -1)
2914			return (NULL);
2915	}
2916
2917	return(newdir);
2918}
2919