ftpd.c revision 1.111
1/*	$OpenBSD: ftpd.c,v 1.111 2001/12/17 23:02:53 millert 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. All advertising materials mentioning features or use of this software
46 *    must display the following acknowledgement:
47 *	This product includes software developed by the University of
48 *	California, Berkeley and its contributors.
49 * 4. Neither the name of the University nor the names of its contributors
50 *    may be used to endorse or promote products derived from this software
51 *    without specific prior written permission.
52 *
53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63 * SUCH DAMAGE.
64 */
65
66#ifndef lint
67static char copyright[] =
68"@(#) Copyright (c) 1985, 1988, 1990, 1992, 1993, 1994\n\
69	The Regents of the University of California.  All rights reserved.\n";
70#endif /* not lint */
71
72#ifndef lint
73#if 0
74static char sccsid[] = "@(#)ftpd.c	8.4 (Berkeley) 4/16/94";
75#else
76static char rcsid[] = "$OpenBSD: ftpd.c,v 1.111 2001/12/17 23:02:53 millert Exp $";
77#endif
78#endif /* not lint */
79
80/*
81 * FTP server.
82 */
83#include <sys/param.h>
84#include <sys/stat.h>
85#include <sys/ioctl.h>
86#include <sys/socket.h>
87#include <sys/wait.h>
88#include <sys/mman.h>
89
90#include <netinet/in.h>
91#include <netinet/in_systm.h>
92#include <netinet/ip.h>
93#include <netinet/tcp.h>
94
95#define	FTP_NAMES
96#include <arpa/ftp.h>
97#include <arpa/inet.h>
98#include <arpa/telnet.h>
99
100#include <ctype.h>
101#include <dirent.h>
102#include <err.h>
103#include <errno.h>
104#include <fcntl.h>
105#include <glob.h>
106#include <limits.h>
107#include <login_cap.h>
108#include <netdb.h>
109#include <pwd.h>
110#include <signal.h>
111#include <stdio.h>
112#include <stdlib.h>
113#include <string.h>
114#include <syslog.h>
115#include <time.h>
116#include <vis.h>
117#include <unistd.h>
118#include <util.h>
119#include <utmp.h>
120#include <bsd_auth.h>
121
122#if defined(TCPWRAPPERS)
123#include <tcpd.h>
124#endif	/* TCPWRAPPERS */
125
126#include "pathnames.h"
127#include "extern.h"
128
129#ifdef __STDC__
130#include <stdarg.h>
131#else
132#include <varargs.h>
133#endif
134
135static char version[] = "Version 6.5/OpenBSD";
136
137extern	off_t restart_point;
138extern	char cbuf[];
139
140union sockunion server_addr;
141union sockunion ctrl_addr;
142union sockunion data_source;
143union sockunion data_dest;
144union sockunion his_addr;
145union sockunion pasv_addr;
146
147sigset_t allsigs;
148
149int	daemon_mode = 0;
150int	data;
151int	logged_in;
152struct	passwd *pw;
153int	debug = 0;
154int	timeout = 900;    /* timeout after 15 minutes of inactivity */
155int	maxtimeout = 7200;/* don't allow idle time to be set beyond 2 hours */
156int	logging;
157int	high_data_ports = 0;
158int	anon_only = 0;
159int	multihome = 0;
160int	guest;
161int	stats;
162int	statfd = -1;
163int	portcheck = 1;
164int	dochroot;
165int	type;
166int	form;
167int	stru;			/* avoid C keyword */
168int	mode;
169int	doutmp = 0;		/* update utmp file */
170int	usedefault = 1;		/* for data transfers */
171int	pdata = -1;		/* for passive mode */
172int	family = AF_INET;
173volatile sig_atomic_t transflag;
174off_t	file_size;
175off_t	byte_count;
176#if !defined(CMASK) || CMASK == 0
177#undef CMASK
178#define CMASK 022
179#endif
180int	defumask = CMASK;		/* default umask value */
181int	umaskchange = 1;		/* allow user to change umask value. */
182char	tmpline[7];
183char	hostname[MAXHOSTNAMELEN];
184char	remotehost[MAXHOSTNAMELEN];
185char	dhostname[MAXHOSTNAMELEN];
186char	*guestpw;
187static char ttyline[20];
188char	*tty = ttyline;		/* for klogin */
189static struct utmp utmp;	/* for utmp */
190static	login_cap_t *lc;
191static	auth_session_t *as;
192static	volatile sig_atomic_t recvurg;
193
194#if defined(TCPWRAPPERS)
195int	allow_severity = LOG_INFO;
196int	deny_severity = LOG_NOTICE;
197#endif	/* TCPWRAPPERS */
198
199char	*ident = NULL;
200
201
202int epsvall = 0;
203
204/*
205 * Timeout intervals for retrying connections
206 * to hosts that don't accept PORT cmds.  This
207 * is a kludge, but given the problems with TCP...
208 */
209#define	SWAITMAX	90	/* wait at most 90 seconds */
210#define	SWAITINT	5	/* interval between retries */
211
212int	swaitmax = SWAITMAX;
213int	swaitint = SWAITINT;
214
215#ifdef HASSETPROCTITLE
216char	proctitle[BUFSIZ];	/* initial part of title */
217#endif /* HASSETPROCTITLE */
218
219#define LOGCMD(cmd, file) \
220	if (logging > 1) \
221	    syslog(LOG_INFO,"%s %s%s", cmd, \
222		*(file) == '/' ? "" : curdir(), file);
223#define LOGCMD2(cmd, file1, file2) \
224	 if (logging > 1) \
225	    syslog(LOG_INFO,"%s %s%s %s%s", cmd, \
226		*(file1) == '/' ? "" : curdir(), file1, \
227		*(file2) == '/' ? "" : curdir(), file2);
228#define LOGBYTES(cmd, file, cnt) \
229	if (logging > 1) { \
230		if (cnt == (off_t)-1) \
231		    syslog(LOG_INFO,"%s %s%s", cmd, \
232			*(file) == '/' ? "" : curdir(), file); \
233		else \
234		    syslog(LOG_INFO, "%s %s%s = %qd bytes", \
235			cmd, (*(file) == '/') ? "" : curdir(), file, cnt); \
236	}
237
238static void	 ack __P((char *));
239static void	 sigurg __P((int));
240static void	 myoob __P((void));
241static int	 checkuser __P((char *, char *));
242static FILE	*dataconn __P((char *, off_t, char *));
243static void	 dolog __P((struct sockaddr *));
244static char	*copy_dir __P((char *, struct passwd *));
245static char	*curdir __P((void));
246static void	 end_login __P((void));
247static FILE	*getdatasock __P((char *));
248static int	guniquefd __P((char *, char **));
249static void	 lostconn __P((int));
250static void	 sigquit __P((int));
251static int	 receive_data __P((FILE *, FILE *));
252static void	 replydirname __P((const char *, const char *));
253static int	 send_data __P((FILE *, FILE *, off_t, off_t, int));
254static struct passwd *
255		 sgetpwnam __P((char *));
256static void	 reapchild __P((int));
257static int	 check_host __P((struct sockaddr *));
258static void	 usage __P((void));
259
260void	 logxfer __P((char *, off_t, time_t));
261
262static char *
263curdir()
264{
265	static char path[MAXPATHLEN+1];	/* path + '/' */
266
267	if (getcwd(path, sizeof(path)-1) == NULL)
268		return ("");
269	if (path[1] != '\0')		/* special case for root dir. */
270		strcat(path, "/");
271	/* For guest account, skip / since it's chrooted */
272	return (guest ? path+1 : path);
273}
274
275char *argstr = "AdDhlMSt:T:u:UvP46";
276
277static void
278usage()
279{
280	syslog(LOG_ERR,
281	    "usage: ftpd [-AdDhlMSUv] [-t timeout] [-T maxtimeout] [-u mask]");
282	exit(2);
283}
284
285int
286main(argc, argv, envp)
287	int argc;
288	char *argv[];
289	char **envp;
290{
291	int addrlen, ch, on = 1, tos;
292	char *cp, line[LINE_MAX];
293	FILE *fp;
294	struct hostent *hp;
295	struct sigaction sa;
296
297	tzset();		/* in case no timezone database in ~ftp */
298	sigfillset(&allsigs);	/* used to block signals while root */
299	sigemptyset(&sa.sa_mask);
300	sa.sa_flags = SA_RESTART;
301
302	while ((ch = getopt(argc, argv, argstr)) != -1) {
303		switch (ch) {
304		case 'A':
305			anon_only = 1;
306			break;
307
308		case 'd':
309			debug = 1;
310			break;
311
312		case 'D':
313			daemon_mode = 1;
314			break;
315
316		case 'P':
317			portcheck = 0;
318			break;
319
320		case 'h':
321			high_data_ports = 1;
322			break;
323
324		case 'l':
325			logging++;	/* > 1 == extra logging */
326			break;
327
328		case 'M':
329			multihome = 1;
330			break;
331
332		case 'S':
333			stats = 1;
334			break;
335
336		case 't':
337			timeout = atoi(optarg);
338			if (maxtimeout < timeout)
339				maxtimeout = timeout;
340			break;
341
342		case 'T':
343			maxtimeout = atoi(optarg);
344			if (timeout > maxtimeout)
345				timeout = maxtimeout;
346			break;
347
348		case 'u':
349		    {
350			long val = 0;
351			char *p;
352			umaskchange = 0;
353
354			val = strtol(optarg, &p, 8);
355			if (*p != '\0' || val < 0 || (val & ~ACCESSPERMS)) {
356				syslog(LOG_ERR,
357				    "ftpd: %s is a bad value for -u, aborting..",
358				    optarg);
359				exit(2);
360			} else
361				defumask = val;
362			break;
363		    }
364
365		case 'U':
366			doutmp = 1;
367			break;
368
369		case 'v':
370			debug = 1;
371			break;
372
373		case '4':
374			family = AF_INET;
375			break;
376
377		case '6':
378			family = AF_INET6;
379			break;
380
381		default:
382			usage();
383			break;
384		}
385	}
386
387	(void) freopen(_PATH_DEVNULL, "w", stderr);
388
389	/*
390	 * LOG_NDELAY sets up the logging connection immediately,
391	 * necessary for anonymous ftp's that chroot and can't do it later.
392	 */
393	openlog("ftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
394
395	if (daemon_mode) {
396		int ctl_sock, fd;
397		struct servent *sv;
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		 * Get port number for ftp/tcp.
410		 */
411		sv = getservbyname("ftp", "tcp");
412		if (sv == NULL) {
413			syslog(LOG_ERR, "getservbyname for ftp failed");
414			exit(1);
415		}
416		/*
417		 * Open a socket, bind it to the FTP port, and start
418		 * listening.
419		 */
420		ctl_sock = socket(family, SOCK_STREAM, 0);
421		if (ctl_sock < 0) {
422			syslog(LOG_ERR, "control socket: %m");
423			exit(1);
424		}
425		if (setsockopt(ctl_sock, SOL_SOCKET, SO_REUSEADDR,
426		    (char *)&on, sizeof(on)) < 0)
427			syslog(LOG_ERR, "control setsockopt: %m");
428		memset(&server_addr, 0, sizeof(server_addr));
429		server_addr.su_sin.sin_family = family;
430		switch (family) {
431		case AF_INET:
432			server_addr.su_len = sizeof(struct sockaddr_in);
433			server_addr.su_sin.sin_port = sv->s_port;
434			break;
435		case AF_INET6:
436			server_addr.su_len = sizeof(struct sockaddr_in6);
437			server_addr.su_sin6.sin6_port = sv->s_port;
438			break;
439		}
440		if (bind(ctl_sock, (struct sockaddr *)&server_addr,
441			 server_addr.su_len)) {
442			syslog(LOG_ERR, "control bind: %m");
443			exit(1);
444		}
445		if (listen(ctl_sock, 32) < 0) {
446			syslog(LOG_ERR, "control listen: %m");
447			exit(1);
448		}
449		/* Stash pid in pidfile */
450		if (pidfile(NULL))
451			syslog(LOG_ERR, "can't open pidfile: %m");
452		/*
453		 * Loop forever accepting connection requests and forking off
454		 * children to handle them.
455		 */
456		while (1) {
457			addrlen = sizeof(his_addr);
458			fd = accept(ctl_sock, (struct sockaddr *)&his_addr,
459				    &addrlen);
460			if (fork() == 0) {
461				/* child */
462				(void) dup2(fd, 0);
463				(void) dup2(fd, 1);
464				close(ctl_sock);
465				break;
466			}
467			close(fd);
468		}
469
470#if defined(TCPWRAPPERS)
471		/* ..in the child. */
472		if (!check_host((struct sockaddr *)&his_addr))
473			exit(1);
474#endif	/* TCPWRAPPERS */
475	} else {
476		addrlen = sizeof(his_addr);
477		if (getpeername(0, (struct sockaddr *)&his_addr,
478				&addrlen) < 0) {
479			/* syslog(LOG_ERR, "getpeername (%s): %m", argv[0]); */
480			exit(1);
481		}
482	}
483
484	/* set this here so klogin can use it... */
485	(void)snprintf(ttyline, sizeof(ttyline), "ftp%d", getpid());
486
487	sa.sa_handler = sigquit;
488	(void) sigaction(SIGHUP, &sa, NULL);
489	(void) sigaction(SIGINT, &sa, NULL);
490	(void) sigaction(SIGQUIT, &sa, NULL);
491	(void) sigaction(SIGTERM, &sa, NULL);
492
493	sa.sa_handler = lostconn;
494	(void) sigaction(SIGPIPE, &sa, NULL);
495
496	sa.sa_handler = SIG_IGN;
497	(void) sigaction(SIGCHLD, &sa, NULL);
498
499	sa.sa_handler = sigurg;
500	sa.sa_flags = 0;		/* don't restart syscalls for SIGURG */
501	(void) sigaction(SIGURG, &sa, NULL);
502
503	addrlen = sizeof(ctrl_addr);
504	if (getsockname(0, (struct sockaddr *)&ctrl_addr, &addrlen) < 0) {
505		syslog(LOG_ERR, "getsockname: %m");
506		exit(1);
507	}
508	if (his_addr.su_family == AF_INET6
509	 && IN6_IS_ADDR_V4MAPPED(&his_addr.su_sin6.sin6_addr)) {
510#if 1
511		/*
512		 * IPv4 control connection arrived to AF_INET6 socket.
513		 * I hate to do this, but this is the easiest solution.
514		 */
515		union sockunion tmp_addr;
516		const int off = sizeof(struct in6_addr) - sizeof(struct in_addr);
517
518		tmp_addr = his_addr;
519		memset(&his_addr, 0, sizeof(his_addr));
520		his_addr.su_sin.sin_family = AF_INET;
521		his_addr.su_sin.sin_len = sizeof(his_addr.su_sin);
522		memcpy(&his_addr.su_sin.sin_addr,
523		    &tmp_addr.su_sin6.sin6_addr.s6_addr[off],
524		    sizeof(his_addr.su_sin.sin_addr));
525		his_addr.su_sin.sin_port = tmp_addr.su_sin6.sin6_port;
526
527		tmp_addr = ctrl_addr;
528		memset(&ctrl_addr, 0, sizeof(ctrl_addr));
529		ctrl_addr.su_sin.sin_family = AF_INET;
530		ctrl_addr.su_sin.sin_len = sizeof(ctrl_addr.su_sin);
531		memcpy(&ctrl_addr.su_sin.sin_addr,
532		    &tmp_addr.su_sin6.sin6_addr.s6_addr[off],
533		    sizeof(ctrl_addr.su_sin.sin_addr));
534		ctrl_addr.su_sin.sin_port = tmp_addr.su_sin6.sin6_port;
535#else
536		while (fgets(line, sizeof(line), fd) != NULL) {
537			if ((cp = strchr(line, '\n')) != NULL)
538				*cp = '\0';
539			lreply(530, "%s", line);
540		}
541		(void) fflush(stdout);
542		(void) fclose(fd);
543		reply(530,
544			"Connection from IPv4 mapped address is not supported.");
545		exit(0);
546#endif
547	}
548#ifdef IP_TOS
549	if (his_addr.su_family == AF_INET) {
550		tos = IPTOS_LOWDELAY;
551		if (setsockopt(0, IPPROTO_IP, IP_TOS, (char *)&tos,
552		    sizeof(int)) < 0)
553			syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
554	}
555#endif
556	data_source.su_port = htons(ntohs(ctrl_addr.su_port) - 1);
557
558	/* Try to handle urgent data inline */
559#ifdef SO_OOBINLINE
560	if (setsockopt(0, SOL_SOCKET, SO_OOBINLINE, (char *)&on, sizeof(on)) < 0)
561		syslog(LOG_ERR, "setsockopt: %m");
562#endif
563
564#ifdef	F_SETOWN
565	if (fcntl(fileno(stdin), F_SETOWN, getpid()) == -1)
566		syslog(LOG_ERR, "fcntl F_SETOWN: %m");
567#endif
568	dolog((struct sockaddr *)&his_addr);
569	/*
570	 * Set up default state
571	 */
572	data = -1;
573	type = TYPE_A;
574	form = FORM_N;
575	stru = STRU_F;
576	mode = MODE_S;
577	tmpline[0] = '\0';
578
579	/* If logins are disabled, print out the message. */
580	if ((fp = fopen(_PATH_NOLOGIN, "r")) != NULL) {
581		while (fgets(line, sizeof(line), fp) != NULL) {
582			if ((cp = strchr(line, '\n')) != NULL)
583				*cp = '\0';
584			lreply(530, "%s", line);
585		}
586		(void) fflush(stdout);
587		(void) fclose(fp);
588		reply(530, "System not available.");
589		exit(0);
590	}
591	if ((fp = fopen(_PATH_FTPWELCOME, "r")) != NULL) {
592		while (fgets(line, sizeof(line), fp) != NULL) {
593			if ((cp = strchr(line, '\n')) != NULL)
594				*cp = '\0';
595			lreply(220, "%s", line);
596		}
597		(void) fflush(stdout);
598		(void) fclose(fp);
599		/* reply(220,) must follow */
600	}
601	(void) gethostname(hostname, sizeof(hostname));
602
603	/* Make sure hostname is fully qualified. */
604	hp = gethostbyname(hostname);
605	if (hp != NULL)
606		strcpy(hostname, hp->h_name);
607
608	if (multihome) {
609		getnameinfo((struct sockaddr *)&ctrl_addr, ctrl_addr.su_len,
610		    dhostname, sizeof(dhostname), NULL, 0, 0);
611	}
612
613	reply(220, "%s FTP server (%s) ready.",
614	    (multihome ? dhostname : hostname), version);
615	for (;;)
616		(void) yyparse();
617	/* NOTREACHED */
618}
619
620/*
621 * Signal handlers.
622 */
623
624static void
625lostconn(signo)
626	int signo;
627{
628	struct syslog_data sdata = SYSLOG_DATA_INIT;
629
630	sigprocmask(SIG_BLOCK, &allsigs, NULL);
631	if (debug)
632		syslog_r(LOG_DEBUG, &sdata, "lost connection");
633	dologout(1);
634}
635
636static void
637sigquit(signo)
638	int signo;
639{
640	struct syslog_data sdata = SYSLOG_DATA_INIT;
641
642	sigprocmask(SIG_BLOCK, &allsigs, NULL);
643	syslog_r(LOG_ERR, &sdata, "got signal %s", sys_signame[signo]);
644	dologout(1);
645}
646
647/*
648 * Save the result of a getpwnam.  Used for USER command, since
649 * the data returned must not be clobbered by any other command
650 * (e.g., globbing).
651 */
652static struct passwd *
653sgetpwnam(name)
654	char *name;
655{
656	static struct passwd *save;
657	struct passwd *pw;
658
659	if ((pw = getpwnam(name)) == NULL)
660		return (pw);
661	if (save) {
662		memset(save->pw_passwd, 0, strlen(save->pw_passwd));
663		free(save);
664	}
665	save = pw_dup(pw);
666	if (save == NULL) {
667		perror_reply(421, "Local resource failure: malloc");
668		dologout(1);
669		/* NOTREACHED */
670	}
671	return (save);
672}
673
674static int login_attempts;	/* number of failed login attempts */
675static int askpasswd;		/* had user command, ask for passwd */
676static char curname[MAXLOGNAME];	/* current USER name */
677
678/*
679 * USER command.
680 * Sets global passwd pointer pw if named account exists and is acceptable;
681 * sets askpasswd if a PASS command is expected.  If logged in previously,
682 * need to reset state.  If name is "ftp" or "anonymous", the name is not in
683 * _PATH_FTPUSERS, and ftp account exists, set guest and pw, then just return.
684 * If account doesn't exist, ask for passwd anyway.  Otherwise, check user
685 * requesting login privileges.  Disallow anyone who does not have a standard
686 * shell as returned by getusershell().  Disallow anyone mentioned in the file
687 * _PATH_FTPUSERS to allow people such as root and uucp to be avoided.
688 */
689void
690user(name)
691	char *name;
692{
693	char *cp, *shell, *style;
694	char *class = NULL;
695
696	if (logged_in) {
697		if (guest) {
698			reply(530, "Can't change user from guest login.");
699			return;
700		} else if (dochroot) {
701			reply(530, "Can't change user from chroot user.");
702			return;
703		}
704		login_close(lc);
705		lc = NULL;
706		if (as) {
707			auth_close(as);
708			as = NULL;
709		}
710		end_login();
711	}
712
713	if ((style = strchr(name, ':')) != NULL)
714		*style++ = 0;
715
716	guest = 0;
717	if (strcmp(name, "ftp") == 0 || strcmp(name, "anonymous") == 0) {
718		if (checkuser(_PATH_FTPUSERS, "ftp") ||
719		    checkuser(_PATH_FTPUSERS, "anonymous"))
720			reply(530, "User %s access denied.", name);
721		else if ((pw = sgetpwnam("ftp")) != NULL) {
722			guest = 1;
723			askpasswd = 1;
724			lc = login_getclass(pw->pw_class);
725			reply(331,
726			"Guest login ok, send your email address as password.");
727		} else
728			reply(530, "User %s unknown.", name);
729		if (!askpasswd && logging)
730			syslog(LOG_NOTICE,
731			    "ANONYMOUS FTP LOGIN REFUSED FROM %s", remotehost);
732		return;
733	}
734
735	shell = _PATH_BSHELL;
736	if ((pw = sgetpwnam(name))) {
737		class = pw->pw_class;
738		if (pw->pw_shell != NULL && *pw->pw_shell != '\0')
739			shell = pw->pw_shell;
740		while ((cp = getusershell()) != NULL)
741			if (strcmp(cp, shell) == 0)
742				break;
743		shell = cp;
744		endusershell();
745	}
746
747	/* Get login class; if invalid style treat like unknown user. */
748	lc = login_getclass(class);
749	if (lc && (style = login_getstyle(lc, style, "auth-ftp")) == NULL) {
750		login_close(lc);
751		lc = NULL;
752		pw = NULL;
753	}
754
755	/* Do pre-authentication setup. */
756	if (lc && ((as = auth_open()) == NULL ||
757	    auth_setitem(as, AUTHV_STYLE, style) < 0 ||
758	    auth_setitem(as, AUTHV_NAME, name) < 0 ||
759	    auth_setitem(as, AUTHV_CLASS, class) < 0 ||
760	    auth_setoption(as, "login", "yes") < 0 ||
761	    auth_setoption(as, "notickets", "yes") < 0)) {
762		if (as) {
763			auth_close(as);
764			as = NULL;
765		}
766		login_close(lc);
767		lc = NULL;
768		reply(421, "Local resource failure");
769		return;
770	}
771	if (logging)
772		strlcpy(curname, name, sizeof(curname));
773
774	dochroot = (lc && login_getcapbool(lc, "ftp-chroot", 0)) ||
775	    checkuser(_PATH_FTPCHROOT, name);
776	if (anon_only && !dochroot) {
777		reply(530, "Sorry, only anonymous ftp allowed.");
778		return;
779	}
780	if (pw) {
781		if ((!shell && !dochroot) || checkuser(_PATH_FTPUSERS, name)) {
782			reply(530, "User %s access denied.", name);
783			if (logging)
784				syslog(LOG_NOTICE,
785				    "FTP LOGIN REFUSED FROM %s, %s",
786				    remotehost, name);
787			pw = NULL;
788			return;
789		}
790	}
791
792	if (as != NULL && (cp = auth_challenge(as)) != NULL)
793		reply(331, cp);
794	else
795		reply(331, "Password required for %s.", name);
796
797	askpasswd = 1;
798	/*
799	 * Delay before reading passwd after first failed
800	 * attempt to slow down passwd-guessing programs.
801	 */
802	if (login_attempts)
803		sleep((unsigned) login_attempts);
804}
805
806/*
807 * Check if a user is in the file "fname"
808 */
809static int
810checkuser(fname, name)
811	char *fname;
812	char *name;
813{
814	FILE *fp;
815	int found = 0;
816	char *p, line[BUFSIZ];
817
818	if ((fp = fopen(fname, "r")) != NULL) {
819		while (fgets(line, sizeof(line), fp) != NULL)
820			if ((p = strchr(line, '\n')) != NULL) {
821				*p = '\0';
822				if (line[0] == '#')
823					continue;
824				if (strcmp(line, name) == 0) {
825					found = 1;
826					break;
827				}
828			}
829		(void) fclose(fp);
830	}
831	return (found);
832}
833
834/*
835 * Terminate login as previous user, if any, resetting state;
836 * used when USER command is given or login fails.
837 */
838static void
839end_login()
840{
841
842	sigprocmask (SIG_BLOCK, &allsigs, NULL);
843	(void) seteuid((uid_t)0);
844	if (logged_in) {
845		ftpdlogwtmp(ttyline, "", "");
846		if (doutmp)
847			logout(utmp.ut_line);
848	}
849	pw = NULL;
850	/* umask is restored in ftpcmd.y */
851	setusercontext(NULL, getpwuid(0), (uid_t)0,
852	    LOGIN_SETPRIORITY|LOGIN_SETRESOURCES);
853	logged_in = 0;
854	guest = 0;
855	dochroot = 0;
856}
857
858void
859pass(passwd)
860	char *passwd;
861{
862	int authok, flags;
863	FILE *fp;
864	static char homedir[MAXPATHLEN];
865	char *motd, *dir, rootdir[MAXPATHLEN];
866
867	if (logged_in || askpasswd == 0) {
868		reply(503, "Login with USER first.");
869		return;
870	}
871	askpasswd = 0;
872	if (!guest) {		/* "ftp" is only account allowed no password */
873		authok = 0;
874		if (pw == NULL) {
875			useconds_t us;
876
877			/* Sleep between 1 and 3 seconds to emulate a crypt. */
878			us = arc4random() % 3000000;
879			usleep(us);
880		} else {
881			authok = auth_userresponse(as, passwd, 0);
882			as = NULL;
883		}
884		if (authok == 0) {
885			reply(530, "Login incorrect.");
886			if (logging)
887				syslog(LOG_NOTICE,
888				    "FTP LOGIN FAILED FROM %s, %s",
889				    remotehost, curname);
890			pw = NULL;
891			if (login_attempts++ >= 5) {
892				syslog(LOG_NOTICE,
893				    "repeated login failures from %s",
894				    remotehost);
895				exit(0);
896			}
897			return;
898		}
899	} else if (lc != NULL) {
900		/* Save anonymous' password. */
901		guestpw = strdup(passwd);
902		if (guestpw == (char *)NULL)
903			fatal("Out of memory");
904
905		if ((as = auth_open()) == NULL)
906			fatal("Out of memory");
907		auth_setoption(as, "FTPD_HOST",
908		    multihome ? dhostname : hostname);
909		authok = auth_approval(as, lc, pw->pw_name, "ftp");
910		auth_close(as);
911		as = NULL;
912		if (authok == 0) {
913			syslog(LOG_INFO|LOG_AUTH,
914			    "FTP LOGIN FAILED (HOST) as %s: approval failure.",
915			    pw->pw_name);
916			reply(530, "Approval failure.\n");
917			exit(0);
918		}
919	} else {
920		syslog(LOG_INFO|LOG_AUTH,
921		    "FTP LOGIN CLASS %s MISSING for %s: approval failure.",
922		    pw->pw_class, pw->pw_name);
923		reply(530, "Permission denied.\n");
924		exit(0);
925	}
926	login_attempts = 0;		/* this time successful */
927	if (setegid((gid_t)pw->pw_gid) < 0) {
928		reply(550, "Can't set gid.");
929		return;
930	}
931	/* set umask via setusercontext() unless -u flag was given. */
932	flags = LOGIN_SETGROUP|LOGIN_SETPRIORITY|LOGIN_SETRESOURCES;
933	if (umaskchange)
934		flags |= LOGIN_SETUMASK;
935	else
936		(void) umask(defumask);
937	setusercontext(lc, pw, (uid_t)0, flags);
938
939	/* open wtmp before chroot */
940	ftpdlogwtmp(ttyline, pw->pw_name, remotehost);
941
942	/* open utmp before chroot */
943	if (doutmp) {
944		memset((void *)&utmp, 0, sizeof(utmp));
945		(void)time(&utmp.ut_time);
946		(void)strncpy(utmp.ut_name, pw->pw_name, sizeof(utmp.ut_name));
947		(void)strncpy(utmp.ut_host, remotehost, sizeof(utmp.ut_host));
948		(void)strncpy(utmp.ut_line, ttyline, sizeof(utmp.ut_line));
949		login(&utmp);
950	}
951
952	/* open stats file before chroot */
953	if (guest && (stats == 1) && (statfd < 0))
954		if ((statfd = open(_PATH_FTPDSTATFILE, O_WRONLY|O_APPEND)) < 0)
955			stats = 0;
956
957	logged_in = 1;
958
959	if ((dir = login_getcapstr(lc, "ftp-dir", NULL, NULL))) {
960		char *newdir;
961
962		newdir = copy_dir(dir, pw);
963		if (newdir == NULL) {
964			perror_reply(421, "Local resource failure: malloc");
965			dologout(1);
966			/* NOTREACHED */
967		}
968		free(dir);
969		free(pw->pw_dir);
970		pw->pw_dir = newdir;
971	}
972
973	if (guest || dochroot) {
974		if (multihome && guest) {
975			struct stat ts;
976
977			/* Compute root directory. */
978			snprintf(rootdir, sizeof(rootdir), "%s/%s",
979				  pw->pw_dir, dhostname);
980			if (stat(rootdir, &ts) < 0) {
981				snprintf(rootdir, sizeof(rootdir), "%s/%s",
982					  pw->pw_dir, hostname);
983			}
984		} else
985			strcpy(rootdir, pw->pw_dir);
986	}
987	if (guest) {
988		/*
989		 * We MUST do a chdir() after the chroot. Otherwise
990		 * the old current directory will be accessible as "."
991		 * outside the new root!
992		 */
993		if (chroot(rootdir) < 0 || chdir("/") < 0) {
994			reply(550, "Can't set guest privileges.");
995			goto bad;
996		}
997		strcpy(pw->pw_dir, "/");
998		if (setenv("HOME", "/", 1) == -1) {
999			reply(550, "Can't setup environment.");
1000			goto bad;
1001		}
1002	} else if (dochroot) {
1003		if (chroot(rootdir) < 0 || chdir("/") < 0) {
1004			reply(550, "Can't change root.");
1005			goto bad;
1006		}
1007		strcpy(pw->pw_dir, "/");
1008		if (setenv("HOME", "/", 1) == -1) {
1009			reply(550, "Can't setup environment.");
1010			goto bad;
1011		}
1012	} else if (chdir(pw->pw_dir) < 0) {
1013		if (chdir("/") < 0) {
1014			reply(530, "User %s: can't change directory to %s.",
1015			    pw->pw_name, pw->pw_dir);
1016			goto bad;
1017		} else
1018			lreply(230, "No directory! Logging in with home=/");
1019	}
1020	if (seteuid((uid_t)pw->pw_uid) < 0) {
1021		reply(550, "Can't set uid.");
1022		goto bad;
1023	}
1024	sigprocmask(SIG_UNBLOCK, &allsigs, NULL);
1025
1026	/*
1027	 * Set home directory so that use of ~ (tilde) works correctly.
1028	 */
1029	if (getcwd(homedir, MAXPATHLEN) != NULL) {
1030		if (setenv("HOME", homedir, 1) == -1) {
1031			reply(550, "Can't setup environment.");
1032			goto bad;
1033		}
1034	}
1035
1036	/*
1037	 * Display a login message, if it exists.
1038	 * N.B. reply(230,) must follow the message.
1039	 */
1040	motd = login_getcapstr(lc, "welcome", NULL, NULL);
1041	if ((fp = fopen(motd ? motd : _PATH_FTPLOGINMESG, "r")) != NULL) {
1042		char *cp, line[LINE_MAX];
1043
1044		while (fgets(line, sizeof(line), fp) != NULL) {
1045			if ((cp = strchr(line, '\n')) != NULL)
1046				*cp = '\0';
1047			lreply(230, "%s", line);
1048		}
1049		(void) fflush(stdout);
1050		(void) fclose(fp);
1051	}
1052	if (motd != NULL)
1053		free(motd);
1054	if (guest) {
1055		if (ident != NULL)
1056			free(ident);
1057		ident = strdup(passwd);
1058		if (ident == NULL)
1059			fatal("Ran out of memory.");
1060		reply(230, "Guest login ok, access restrictions apply.");
1061#ifdef HASSETPROCTITLE
1062		snprintf(proctitle, sizeof(proctitle),
1063		    "%s: anonymous/%.*s", remotehost,
1064		    (int)(sizeof(proctitle) - sizeof(remotehost) -
1065		    sizeof(": anonymous/")), passwd);
1066		setproctitle("%s", proctitle);
1067#endif /* HASSETPROCTITLE */
1068		if (logging)
1069			syslog(LOG_INFO, "ANONYMOUS FTP LOGIN FROM %s, %s",
1070			    remotehost, passwd);
1071	} else {
1072		reply(230, "User %s logged in.", pw->pw_name);
1073#ifdef HASSETPROCTITLE
1074		snprintf(proctitle, sizeof(proctitle),
1075		    "%s: %s", remotehost, pw->pw_name);
1076		setproctitle("%s", proctitle);
1077#endif /* HASSETPROCTITLE */
1078		if (logging)
1079			syslog(LOG_INFO, "FTP LOGIN FROM %s as %s",
1080			    remotehost, pw->pw_name);
1081	}
1082	login_close(lc);
1083	lc = NULL;
1084	return;
1085bad:
1086	/* Forget all about it... */
1087	login_close(lc);
1088	lc = NULL;
1089	end_login();
1090}
1091
1092void
1093retrieve(cmd, name)
1094	char *cmd, *name;
1095{
1096	FILE *fin, *dout;
1097	struct stat st;
1098	int (*closefunc) __P((FILE *));
1099	time_t start;
1100
1101	if (cmd == 0) {
1102		fin = fopen(name, "r"), closefunc = fclose;
1103		st.st_size = 0;
1104	} else {
1105		char line[BUFSIZ];
1106
1107		(void) snprintf(line, sizeof(line), cmd, name);
1108		name = line;
1109		fin = ftpd_popen(line, "r"), closefunc = ftpd_pclose;
1110		st.st_size = -1;
1111		st.st_blksize = BUFSIZ;
1112	}
1113	if (fin == NULL) {
1114		if (errno != 0) {
1115			perror_reply(550, name);
1116			if (cmd == 0) {
1117				LOGCMD("get", name);
1118			}
1119		}
1120		return;
1121	}
1122	byte_count = -1;
1123	if (cmd == 0 && (fstat(fileno(fin), &st) < 0 || !S_ISREG(st.st_mode))) {
1124		reply(550, "%s: not a plain file.", name);
1125		goto done;
1126	}
1127	if (restart_point) {
1128		if (type == TYPE_A) {
1129			off_t i, n;
1130			int c;
1131
1132			n = restart_point;
1133			i = 0;
1134			while (i++ < n) {
1135				if ((c=getc(fin)) == EOF) {
1136					perror_reply(550, name);
1137					goto done;
1138				}
1139				if (c == '\n')
1140					i++;
1141			}
1142		} else if (lseek(fileno(fin), restart_point, SEEK_SET) < 0) {
1143			perror_reply(550, name);
1144			goto done;
1145		}
1146	}
1147	dout = dataconn(name, st.st_size, "w");
1148	if (dout == NULL)
1149		goto done;
1150	time(&start);
1151	send_data(fin, dout, st.st_blksize, st.st_size,
1152		  (restart_point == 0 && cmd == 0 && S_ISREG(st.st_mode)));
1153	if ((cmd == 0) && stats)
1154		logxfer(name, byte_count, start);
1155	(void) fclose(dout);
1156	data = -1;
1157done:
1158	if (pdata >= 0)
1159		(void) close(pdata);
1160	pdata = -1;
1161	if (cmd == 0)
1162		LOGBYTES("get", name, byte_count);
1163	(*closefunc)(fin);
1164}
1165
1166void
1167store(name, mode, unique)
1168	char *name, *mode;
1169	int unique;
1170{
1171	FILE *fout, *din;
1172	int (*closefunc) __P((FILE *));
1173	struct stat st;
1174	int fd;
1175
1176	if (restart_point && *mode != 'a')
1177		mode = "r+";
1178
1179	if (unique && stat(name, &st) == 0) {
1180		char *nam;
1181
1182		fd = guniquefd(name, &nam);
1183		if (fd == -1) {
1184			LOGCMD(*mode == 'w' ? "put" : "append", name);
1185			return;
1186		}
1187		name = nam;
1188		fout = fdopen(fd, mode);
1189	} else
1190		fout = fopen(name, mode);
1191
1192	closefunc = fclose;
1193	if (fout == NULL) {
1194		perror_reply(553, name);
1195		LOGCMD(*mode == 'w' ? "put" : "append", name);
1196		return;
1197	}
1198	byte_count = -1;
1199	if (restart_point) {
1200		if (type == TYPE_A) {
1201			off_t i, n;
1202			int c;
1203
1204			n = restart_point;
1205			i = 0;
1206			while (i++ < n) {
1207				if ((c=getc(fout)) == EOF) {
1208					perror_reply(550, name);
1209					goto done;
1210				}
1211				if (c == '\n')
1212					i++;
1213			}
1214			/*
1215			 * We must do this seek to "current" position
1216			 * because we are changing from reading to
1217			 * writing.
1218			 */
1219			if (fseek(fout, 0L, SEEK_CUR) < 0) {
1220				perror_reply(550, name);
1221				goto done;
1222			}
1223		} else if (lseek(fileno(fout), restart_point, SEEK_SET) < 0) {
1224			perror_reply(550, name);
1225			goto done;
1226		}
1227	}
1228	din = dataconn(name, (off_t)-1, "r");
1229	if (din == NULL)
1230		goto done;
1231	if (receive_data(din, fout) == 0) {
1232		if (unique)
1233			reply(226, "Transfer complete (unique file name:%s).",
1234			    name);
1235		else
1236			reply(226, "Transfer complete.");
1237	}
1238	(void) fclose(din);
1239	data = -1;
1240	pdata = -1;
1241done:
1242	LOGBYTES(*mode == 'w' ? "put" : "append", name, byte_count);
1243	(*closefunc)(fout);
1244}
1245
1246static FILE *
1247getdatasock(mode)
1248	char *mode;
1249{
1250	int on = 1, s, t, tries;
1251
1252	if (data >= 0)
1253		return (fdopen(data, mode));
1254	sigprocmask (SIG_BLOCK, &allsigs, NULL);
1255	(void) seteuid((uid_t)0);
1256	s = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
1257	if (s < 0)
1258		goto bad;
1259	if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
1260	    (char *) &on, sizeof(on)) < 0)
1261		goto bad;
1262	/* anchor socket to avoid multi-homing problems */
1263	data_source = ctrl_addr;
1264	data_source.su_port = htons(20); /* ftp-data port */
1265	for (tries = 1; ; tries++) {
1266		if (bind(s, (struct sockaddr *)&data_source,
1267		    data_source.su_len) >= 0)
1268			break;
1269		if (errno != EADDRINUSE || tries > 10)
1270			goto bad;
1271		sleep(tries);
1272	}
1273	(void) seteuid((uid_t)pw->pw_uid);
1274	sigprocmask (SIG_UNBLOCK, &allsigs, NULL);
1275
1276#ifdef IP_TOS
1277	if (ctrl_addr.su_family == AF_INET) {
1278		on = IPTOS_THROUGHPUT;
1279		if (setsockopt(s, IPPROTO_IP, IP_TOS, (char *)&on,
1280		    sizeof(int)) < 0)
1281			syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
1282	}
1283#endif
1284#ifdef TCP_NOPUSH
1285	/*
1286	 * Turn off push flag to keep sender TCP from sending short packets
1287	 * at the boundaries of each write().  Should probably do a SO_SNDBUF
1288	 * to set the send buffer size as well, but that may not be desirable
1289	 * in heavy-load situations.
1290	 */
1291	on = 1;
1292	if (setsockopt(s, IPPROTO_TCP, TCP_NOPUSH, (char *)&on, sizeof(on)) < 0)
1293		syslog(LOG_WARNING, "setsockopt (TCP_NOPUSH): %m");
1294#endif
1295#ifdef SO_SNDBUF
1296	on = 65536;
1297	if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, (char *)&on, sizeof(on)) < 0)
1298		syslog(LOG_WARNING, "setsockopt (SO_SNDBUF): %m");
1299#endif
1300
1301	return (fdopen(s, mode));
1302bad:
1303	/* Return the real value of errno (close may change it) */
1304	t = errno;
1305	(void) seteuid((uid_t)pw->pw_uid);
1306	sigprocmask (SIG_UNBLOCK, &allsigs, NULL);
1307	(void) close(s);
1308	errno = t;
1309	return (NULL);
1310}
1311
1312static FILE *
1313dataconn(name, size, mode)
1314	char *name;
1315	off_t size;
1316	char *mode;
1317{
1318	char sizebuf[32];
1319	FILE *file;
1320	int retry = 0;
1321	in_port_t *p;
1322	char *fa, *ha;
1323	int alen;
1324
1325	file_size = size;
1326	byte_count = 0;
1327	if (size != (off_t) -1) {
1328		(void) snprintf(sizebuf, sizeof(sizebuf), " (%qd bytes)",
1329				size);
1330	} else
1331		sizebuf[0] = '\0';
1332	if (pdata >= 0) {
1333		union sockunion from;
1334		int s, fromlen = sizeof(from);
1335
1336		signal (SIGALRM, toolong);
1337		(void) alarm ((unsigned) timeout);
1338		s = accept(pdata, (struct sockaddr *)&from, &fromlen);
1339		(void) alarm (0);
1340		if (s < 0) {
1341			reply(425, "Can't open data connection.");
1342			(void) close(pdata);
1343			pdata = -1;
1344			return (NULL);
1345		}
1346		switch (from.su_family) {
1347		case AF_INET:
1348			p = (in_port_t *)&from.su_sin.sin_port;
1349			fa = (u_char *)&from.su_sin.sin_addr;
1350			ha = (u_char *)&his_addr.su_sin.sin_addr;
1351			alen = sizeof(struct in_addr);
1352			break;
1353		case AF_INET6:
1354			p = (in_port_t *)&from.su_sin6.sin6_port;
1355			fa = (u_char *)&from.su_sin6.sin6_addr;
1356			ha = (u_char *)&his_addr.su_sin6.sin6_addr;
1357			alen = sizeof(struct in6_addr);
1358			break;
1359		default:
1360			perror_reply(425, "Can't build data connection");
1361			(void) close(pdata);
1362			(void) close(s);
1363			pdata = -1;
1364			return (NULL);
1365		}
1366		if (from.su_family != his_addr.su_family ||
1367		    ntohs(*p) < IPPORT_RESERVED) {
1368			perror_reply(425, "Can't build data connection");
1369			(void) close(pdata);
1370			(void) close(s);
1371			pdata = -1;
1372			return (NULL);
1373		}
1374		if (portcheck && memcmp(fa, ha, alen) != 0) {
1375			perror_reply(435, "Can't build data connection");
1376			(void) close(pdata);
1377			(void) close(s);
1378			pdata = -1;
1379			return (NULL);
1380		}
1381		(void) close(pdata);
1382		pdata = s;
1383		reply(150, "Opening %s mode data connection for '%s'%s.",
1384		    type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1385		return (fdopen(pdata, mode));
1386	}
1387	if (data >= 0) {
1388		reply(125, "Using existing data connection for '%s'%s.",
1389		    name, sizebuf);
1390		usedefault = 1;
1391		return (fdopen(data, mode));
1392	}
1393	if (usedefault)
1394		data_dest = his_addr;
1395	usedefault = 1;
1396	file = getdatasock(mode);
1397	if (file == NULL) {
1398		char hbuf[MAXHOSTNAMELEN], pbuf[10];
1399
1400		getnameinfo((struct sockaddr *)&data_source, data_source.su_len,
1401		    hbuf, sizeof(hbuf), pbuf, sizeof(pbuf),
1402		    NI_NUMERICHOST | NI_NUMERICSERV);
1403		reply(425, "Can't create data socket (%s,%s): %s.",
1404		    hbuf, pbuf, strerror(errno));
1405		return (NULL);
1406	}
1407	data = fileno(file);
1408
1409	/*
1410	 * attempt to connect to reserved port on client machine;
1411	 * this looks like an attack
1412	 */
1413	switch (data_dest.su_family) {
1414	case AF_INET:
1415		p = (in_port_t *)&data_dest.su_sin.sin_port;
1416		fa = (u_char *)&data_dest.su_sin.sin_addr;
1417		ha = (u_char *)&his_addr.su_sin.sin_addr;
1418		alen = sizeof(struct in_addr);
1419		break;
1420	case AF_INET6:
1421		p = (in_port_t *)&data_dest.su_sin6.sin6_port;
1422		fa = (u_char *)&data_dest.su_sin6.sin6_addr;
1423		ha = (u_char *)&his_addr.su_sin6.sin6_addr;
1424		alen = sizeof(struct in6_addr);
1425		break;
1426	default:
1427		perror_reply(425, "Can't build data connection");
1428		(void) fclose(file);
1429		pdata = -1;
1430		return (NULL);
1431	}
1432	if (data_dest.su_family != his_addr.su_family ||
1433	    ntohs(*p) < IPPORT_RESERVED || ntohs(*p) == 2049) {	/* XXX */
1434		perror_reply(425, "Can't build data connection");
1435		(void) fclose(file);
1436		data = -1;
1437		return NULL;
1438	}
1439	if (portcheck && memcmp(fa, ha, alen) != 0) {
1440		perror_reply(435, "Can't build data connection");
1441		(void) fclose(file);
1442		data = -1;
1443		return NULL;
1444	}
1445	while (connect(data, (struct sockaddr *)&data_dest,
1446	    data_dest.su_len) < 0) {
1447		if (errno == EADDRINUSE && retry < swaitmax) {
1448			sleep((unsigned) swaitint);
1449			retry += swaitint;
1450			continue;
1451		}
1452		perror_reply(425, "Can't build data connection");
1453		(void) fclose(file);
1454		data = -1;
1455		return (NULL);
1456	}
1457	reply(150, "Opening %s mode data connection for '%s'%s.",
1458	    type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1459	return (file);
1460}
1461
1462/*
1463 * Tranfer the contents of "instr" to "outstr" peer using the appropriate
1464 * encapsulation of the data subject to Mode, Structure, and Type.
1465 *
1466 * NB: Form isn't handled.
1467 */
1468static int
1469send_data(instr, outstr, blksize, filesize, isreg)
1470	FILE *instr, *outstr;
1471	off_t blksize;
1472	off_t filesize;
1473	int isreg;
1474{
1475	int c, cnt, filefd, netfd;
1476	char *buf, *bp;
1477	size_t len;
1478
1479	transflag++;
1480	switch (type) {
1481
1482	case TYPE_A:
1483		while ((c = getc(instr)) != EOF) {
1484			if (recvurg)
1485				goto got_oob;
1486			byte_count++;
1487			if (c == '\n') {
1488				if (ferror(outstr))
1489					goto data_err;
1490				(void) putc('\r', outstr);
1491			}
1492			(void) putc(c, outstr);
1493		}
1494		fflush(outstr);
1495		transflag = 0;
1496		if (ferror(instr))
1497			goto file_err;
1498		if (ferror(outstr))
1499			goto data_err;
1500		reply(226, "Transfer complete.");
1501		return(0);
1502
1503	case TYPE_I:
1504	case TYPE_L:
1505		/*
1506		 * isreg is only set if we are not doing restart and we
1507		 * are sending a regular file
1508		 */
1509		netfd = fileno(outstr);
1510		filefd = fileno(instr);
1511
1512		if (isreg && filesize < (off_t)16 * 1024 * 1024) {
1513			buf = mmap(0, filesize, PROT_READ, MAP_SHARED, filefd,
1514				   (off_t)0);
1515			if (buf == MAP_FAILED) {
1516				syslog(LOG_WARNING, "mmap(%lu): %m",
1517				    (unsigned long)filesize);
1518				goto oldway;
1519			}
1520			bp = buf;
1521			len = filesize;
1522			do {
1523				cnt = write(netfd, bp, len);
1524				if (recvurg) {
1525					munmap(buf, (size_t)filesize);
1526					goto got_oob;
1527				}
1528				len -= cnt;
1529				bp += cnt;
1530				if (cnt > 0) byte_count += cnt;
1531			} while(cnt > 0 && len > 0);
1532
1533			transflag = 0;
1534			munmap(buf, (size_t)filesize);
1535			if (cnt < 0)
1536				goto data_err;
1537			reply(226, "Transfer complete.");
1538			return(0);
1539		}
1540
1541oldway:
1542		if ((buf = malloc((u_int)blksize)) == NULL) {
1543			transflag = 0;
1544			perror_reply(451, "Local resource failure: malloc");
1545			return(-1);
1546		}
1547
1548		while ((cnt = read(filefd, buf, (u_int)blksize)) > 0 &&
1549		    write(netfd, buf, cnt) == cnt)
1550			byte_count += cnt;
1551		transflag = 0;
1552		(void)free(buf);
1553		if (cnt != 0) {
1554			if (cnt < 0)
1555				goto file_err;
1556			goto data_err;
1557		}
1558		reply(226, "Transfer complete.");
1559		return(0);
1560	default:
1561		transflag = 0;
1562		reply(550, "Unimplemented TYPE %d in send_data", type);
1563		return(-1);
1564	}
1565
1566data_err:
1567	transflag = 0;
1568	perror_reply(426, "Data connection");
1569	return(-1);
1570
1571file_err:
1572	transflag = 0;
1573	perror_reply(551, "Error on input file");
1574	return(-1);
1575
1576got_oob:
1577	myoob();
1578	recvurg = 0;
1579	transflag = 0;
1580	return(-1);
1581}
1582
1583/*
1584 * Transfer data from peer to "outstr" using the appropriate encapulation of
1585 * the data subject to Mode, Structure, and Type.
1586 *
1587 * N.B.: Form isn't handled.
1588 */
1589static int
1590receive_data(instr, outstr)
1591	FILE *instr, *outstr;
1592{
1593	int c;
1594	int cnt;
1595	volatile int bare_lfs = 0;
1596	char buf[BUFSIZ];
1597
1598	transflag++;
1599	switch (type) {
1600
1601	case TYPE_I:
1602	case TYPE_L:
1603		signal (SIGALRM, lostconn);
1604
1605		do {
1606			(void) alarm ((unsigned) timeout);
1607			cnt = read(fileno(instr), buf, sizeof(buf));
1608			(void) alarm (0);
1609			if (recvurg)
1610				goto got_oob;
1611
1612			if (cnt > 0) {
1613				if (write(fileno(outstr), buf, cnt) != cnt)
1614					goto file_err;
1615				byte_count += cnt;
1616			}
1617		} while (cnt > 0);
1618		if (cnt < 0)
1619			goto data_err;
1620		transflag = 0;
1621		return (0);
1622
1623	case TYPE_E:
1624		reply(553, "TYPE E not implemented.");
1625		transflag = 0;
1626		return (-1);
1627
1628	case TYPE_A:
1629		while ((c = getc(instr)) != EOF) {
1630			if (recvurg)
1631				goto got_oob;
1632			byte_count++;
1633			if (c == '\n')
1634				bare_lfs++;
1635			while (c == '\r') {
1636				if (ferror(outstr))
1637					goto data_err;
1638				if ((c = getc(instr)) != '\n') {
1639					(void) putc ('\r', outstr);
1640					if (c == '\0' || c == EOF)
1641						goto contin2;
1642				}
1643			}
1644			(void) putc(c, outstr);
1645	contin2:	;
1646		}
1647		fflush(outstr);
1648		if (ferror(instr))
1649			goto data_err;
1650		if (ferror(outstr))
1651			goto file_err;
1652		transflag = 0;
1653		if (bare_lfs) {
1654			lreply(226,
1655			    "WARNING! %d bare linefeeds received in ASCII mode",
1656			    bare_lfs);
1657			printf("   File may not have transferred correctly.\r\n");
1658		}
1659		return (0);
1660	default:
1661		reply(550, "Unimplemented TYPE %d in receive_data", type);
1662		transflag = 0;
1663		return (-1);
1664	}
1665
1666data_err:
1667	transflag = 0;
1668	perror_reply(426, "Data Connection");
1669	return (-1);
1670
1671file_err:
1672	transflag = 0;
1673	perror_reply(452, "Error writing file");
1674	return (-1);
1675
1676got_oob:
1677	myoob();
1678	recvurg = 0;
1679	transflag = 0;
1680	return (-1);
1681}
1682
1683void
1684statfilecmd(filename)
1685	char *filename;
1686{
1687	FILE *fin;
1688	int c;
1689	int atstart;
1690	char line[LINE_MAX];
1691
1692	(void)snprintf(line, sizeof(line), "/bin/ls -lgA %s", filename);
1693	fin = ftpd_popen(line, "r");
1694	lreply(211, "status of %s:", filename);
1695	atstart = 1;
1696	while ((c = getc(fin)) != EOF) {
1697		if (c == '\n') {
1698			if (ferror(stdout)){
1699				perror_reply(421, "control connection");
1700				(void) ftpd_pclose(fin);
1701				dologout(1);
1702				/* NOTREACHED */
1703			}
1704			if (ferror(fin)) {
1705				perror_reply(551, filename);
1706				(void) ftpd_pclose(fin);
1707				return;
1708			}
1709			(void) putc('\r', stdout);
1710		}
1711		if (atstart && isdigit(c))
1712			(void) putc(' ', stdout);
1713		(void) putc(c, stdout);
1714		atstart = (c == '\n');
1715	}
1716	(void) ftpd_pclose(fin);
1717	reply(211, "End of Status");
1718}
1719
1720void
1721statcmd()
1722{
1723	union sockunion *su;
1724	u_char *a, *p;
1725	char hbuf[MAXHOSTNAMELEN];
1726	int ispassive;
1727
1728	lreply(211, "%s FTP server status:", hostname, version);
1729	printf("     %s\r\n", version);
1730	getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
1731	    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST);
1732	printf("     Connected to %s", remotehost);
1733	if (strcmp(remotehost, hbuf) != 0)
1734		printf(" (%s)", hbuf);
1735	printf("\r\n");
1736	if (logged_in) {
1737		if (guest)
1738			printf("     Logged in anonymously\r\n");
1739		else
1740			printf("     Logged in as %s\r\n", pw->pw_name);
1741	} else if (askpasswd)
1742		printf("     Waiting for password\r\n");
1743	else
1744		printf("     Waiting for user name\r\n");
1745	printf("     TYPE: %s", typenames[type]);
1746	if (type == TYPE_A || type == TYPE_E)
1747		printf(", FORM: %s", formnames[form]);
1748	if (type == TYPE_L)
1749#if NBBY == 8
1750		printf(" %d", NBBY);
1751#else
1752		printf(" %d", bytesize);	/* need definition! */
1753#endif
1754	printf("; STRUcture: %s; transfer MODE: %s\r\n",
1755	    strunames[stru], modenames[mode]);
1756	ispassive = 0;
1757	if (data != -1)
1758		printf("     Data connection open\r\n");
1759	else if (pdata != -1) {
1760		printf("     in Passive mode\r\n");
1761		su = (union sockunion *)&pasv_addr;
1762		ispassive++;
1763		goto printaddr;
1764	} else if (usedefault == 0) {
1765		su = (union sockunion *)&data_dest;
1766printaddr:
1767		/* PASV/PORT */
1768		if (su->su_family == AF_INET) {
1769			if (ispassive)
1770				printf("211- PASV ");
1771			else
1772				printf("211- PORT ");
1773			a = (u_char *) &su->su_sin.sin_addr;
1774			p = (u_char *) &su->su_sin.sin_port;
1775			printf("(%u,%u,%u,%u,%u,%u)\r\n",
1776			    a[0], a[1], a[2], a[3],
1777			    p[0], p[1]);
1778		}
1779
1780		/* LPSV/LPRT */
1781	    {
1782		int alen, af, i;
1783
1784		alen = 0;
1785		switch (su->su_family) {
1786		case AF_INET:
1787			a = (u_char *) &su->su_sin.sin_addr;
1788			p = (u_char *) &su->su_sin.sin_port;
1789			alen = sizeof(su->su_sin.sin_addr);
1790			af = 4;
1791			break;
1792		case AF_INET6:
1793			a = (u_char *) &su->su_sin6.sin6_addr;
1794			p = (u_char *) &su->su_sin6.sin6_port;
1795			alen = sizeof(su->su_sin6.sin6_addr);
1796			af = 6;
1797			break;
1798		default:
1799			af = 0;
1800			break;
1801		}
1802		if (af) {
1803			if (ispassive)
1804				printf("211- LPSV ");
1805			else
1806				printf("211- LPRT ");
1807			printf("(%u,%u", af, alen);
1808			for (i = 0; i < alen; i++)
1809				printf(",%u", a[i]);
1810			printf(",%u,%u,%u)\r\n", 2, p[0], p[1]);
1811		}
1812	    }
1813
1814		/* EPRT/EPSV */
1815	    {
1816		u_char af;
1817
1818		switch (su->su_family) {
1819		case AF_INET:
1820			af = 1;
1821			break;
1822		case AF_INET6:
1823			af = 2;
1824			break;
1825		default:
1826			af = 0;
1827			break;
1828		}
1829		if (af) {
1830			char hbuf[MAXHOSTNAMELEN], pbuf[10];
1831			if (getnameinfo((struct sockaddr *)su, su->su_len,
1832			    hbuf, sizeof(hbuf), pbuf, sizeof(pbuf),
1833			    NI_NUMERICHOST) == 0) {
1834				if (ispassive)
1835					printf("211- EPSV ");
1836				else
1837					printf("211- EPRT ");
1838				printf("(|%u|%s|%s|)\r\n",
1839					af, hbuf, pbuf);
1840			}
1841		}
1842	    }
1843	} else
1844		printf("     No data connection\r\n");
1845	reply(211, "End of status");
1846}
1847
1848void
1849fatal(s)
1850	char *s;
1851{
1852
1853	reply(451, "Error in server: %s\n", s);
1854	reply(221, "Closing connection due to server error.");
1855	dologout(0);
1856	/* NOTREACHED */
1857}
1858
1859void
1860#ifdef __STDC__
1861reply(int n, const char *fmt, ...)
1862#else
1863reply(n, fmt, va_alist)
1864	int n;
1865	char *fmt;
1866	va_dcl
1867#endif
1868{
1869	char *buf, *p, *next;
1870	va_list ap;
1871#ifdef __STDC__
1872	va_start(ap, fmt);
1873#else
1874	va_start(ap);
1875#endif
1876	if (vasprintf(&buf, fmt, ap) == -1 || buf == NULL) {
1877		printf("412 Local resource failure: malloc\r\n");
1878		fflush(stdout);
1879		dologout(1);
1880	}
1881	next = buf;
1882	while ((p = strsep(&next, "\n\r"))) {
1883		printf("%d%s %s\r\n", n, (next != '\0') ? "-" : "", p);
1884		if (debug)
1885			syslog(LOG_DEBUG, "<--- %d%s %s", n,
1886			    (next != '\0') ? "-" : "", p);
1887	}
1888	(void)fflush(stdout);
1889	free(buf);
1890	va_end(ap);
1891}
1892
1893void
1894#ifdef __STDC__
1895lreply(int n, const char *fmt, ...)
1896#else
1897lreply(n, fmt, va_alist)
1898	int n;
1899	char *fmt;
1900	va_dcl
1901#endif
1902{
1903	va_list ap;
1904#ifdef __STDC__
1905	va_start(ap, fmt);
1906#else
1907	va_start(ap);
1908#endif
1909	(void)printf("%d- ", n);
1910	(void)vprintf(fmt, ap);
1911	va_end(ap);
1912	(void)printf("\r\n");
1913	(void)fflush(stdout);
1914	if (debug) {
1915#ifdef __STDC__
1916		va_start(ap, fmt);
1917#else
1918		va_start(ap);
1919#endif
1920		syslog(LOG_DEBUG, "<--- %d- ", n);
1921		vsyslog(LOG_DEBUG, fmt, ap);
1922		va_end(ap);
1923	}
1924}
1925
1926static void
1927ack(s)
1928	char *s;
1929{
1930
1931	reply(250, "%s command successful.", s);
1932}
1933
1934void
1935nack(s)
1936	char *s;
1937{
1938
1939	reply(502, "%s command not implemented.", s);
1940}
1941
1942/* ARGSUSED */
1943void
1944yyerror(s)
1945	char *s;
1946{
1947	char *cp;
1948
1949	if ((cp = strchr(cbuf,'\n')))
1950		*cp = '\0';
1951	reply(500, "'%s': command not understood.", cbuf);
1952}
1953
1954void
1955delete(name)
1956	char *name;
1957{
1958	struct stat st;
1959
1960	LOGCMD("delete", name);
1961	if (stat(name, &st) < 0) {
1962		perror_reply(550, name);
1963		return;
1964	}
1965	if ((st.st_mode&S_IFMT) == S_IFDIR) {
1966		if (rmdir(name) < 0) {
1967			perror_reply(550, name);
1968			return;
1969		}
1970		goto done;
1971	}
1972	if (unlink(name) < 0) {
1973		perror_reply(550, name);
1974		return;
1975	}
1976done:
1977	ack("DELE");
1978}
1979
1980void
1981cwd(path)
1982	char *path;
1983{
1984	FILE *message;
1985
1986	if (chdir(path) < 0)
1987		perror_reply(550, path);
1988	else {
1989		if ((message = fopen(_PATH_CWDMESG, "r")) != NULL) {
1990			char *cp, line[LINE_MAX];
1991
1992			while (fgets(line, sizeof(line), message) != NULL) {
1993				if ((cp = strchr(line, '\n')) != NULL)
1994					*cp = '\0';
1995				lreply(250, "%s", line);
1996			}
1997			(void) fflush(stdout);
1998			(void) fclose(message);
1999		}
2000		ack("CWD");
2001	}
2002}
2003
2004void
2005replydirname(name, message)
2006	const char *name, *message;
2007{
2008	char *p, *ep;
2009	char npath[MAXPATHLEN * 2];
2010
2011	p = npath;
2012	ep = &npath[sizeof(npath) - 1];
2013	while (*name) {
2014		if (*name == '"') {
2015			if (ep - p < 2)
2016				break;
2017			*p++ = *name++;
2018			*p++ = '"';
2019		} else {
2020			if (ep - p < 1)
2021				break;
2022			*p++ = *name++;
2023		}
2024	}
2025	*p = '\0';
2026	reply(257, "\"%s\" %s", npath, message);
2027}
2028
2029void
2030makedir(name)
2031	char *name;
2032{
2033
2034	LOGCMD("mkdir", name);
2035	if (mkdir(name, 0777) < 0)
2036		perror_reply(550, name);
2037	else
2038		replydirname(name, "directory created.");
2039}
2040
2041void
2042removedir(name)
2043	char *name;
2044{
2045
2046	LOGCMD("rmdir", name);
2047	if (rmdir(name) < 0)
2048		perror_reply(550, name);
2049	else
2050		ack("RMD");
2051}
2052
2053void
2054pwd()
2055{
2056	char path[MAXPATHLEN];
2057
2058	if (getcwd(path, sizeof(path)) == NULL)
2059		reply(550, "Can't get current directory: %s.", strerror(errno));
2060	else
2061		replydirname(path, "is current directory.");
2062}
2063
2064char *
2065renamefrom(name)
2066	char *name;
2067{
2068	struct stat st;
2069
2070	if (stat(name, &st) < 0) {
2071		perror_reply(550, name);
2072		return ((char *)0);
2073	}
2074	reply(350, "File exists, ready for destination name");
2075	return (name);
2076}
2077
2078void
2079renamecmd(from, to)
2080	char *from, *to;
2081{
2082
2083	LOGCMD2("rename", from, to);
2084	if (rename(from, to) < 0)
2085		perror_reply(550, "rename");
2086	else
2087		ack("RNTO");
2088}
2089
2090static void
2091dolog(sa)
2092	struct sockaddr *sa;
2093{
2094	char hbuf[sizeof(remotehost)];
2095
2096	getnameinfo(sa, sa->sa_len, hbuf, sizeof(hbuf), NULL, 0, 0);
2097	(void) strlcpy(remotehost, hbuf, sizeof(remotehost));
2098
2099#ifdef HASSETPROCTITLE
2100	snprintf(proctitle, sizeof(proctitle), "%s: connected", remotehost);
2101	setproctitle("%s", proctitle);
2102#endif /* HASSETPROCTITLE */
2103
2104	if (logging)
2105		syslog(LOG_INFO, "connection from %s", remotehost);
2106}
2107
2108/*
2109 * Record logout in wtmp file and exit with supplied status.
2110 * NOTE: because this is called from signal handlers it cannot
2111 *       use stdio (or call other functions that use stdio).
2112 */
2113void
2114dologout(status)
2115	int status;
2116{
2117
2118	transflag = 0;
2119
2120	if (logged_in) {
2121		sigprocmask(SIG_BLOCK, &allsigs, NULL);
2122		(void) seteuid((uid_t)0);
2123		ftpdlogwtmp(ttyline, "", "");
2124		if (doutmp)
2125			logout(utmp.ut_line);
2126	}
2127	/* beware of flushing buffers after a SIGPIPE */
2128	_exit(status);
2129}
2130
2131static void
2132sigurg(signo)
2133	int signo;
2134{
2135
2136	recvurg = 1;
2137}
2138
2139static void
2140myoob()
2141{
2142	char *cp;
2143
2144	/* only process if transfer occurring */
2145	if (!transflag)
2146		return;
2147	cp = tmpline;
2148	if (getline(cp, 7, stdin) == NULL) {
2149		reply(221, "You could at least say goodbye.");
2150		dologout(0);
2151	}
2152	upper(cp);
2153	if (strcmp(cp, "ABOR\r\n") == 0) {
2154		tmpline[0] = '\0';
2155		reply(426, "Transfer aborted. Data connection closed.");
2156		reply(226, "Abort successful");
2157	}
2158	if (strcmp(cp, "STAT\r\n") == 0) {
2159		tmpline[0] = '\0';
2160		if (file_size != (off_t) -1)
2161			reply(213, "Status: %qd of %qd bytes transferred",
2162			    byte_count, file_size);
2163		else
2164			reply(213, "Status: %qd bytes transferred", byte_count);
2165	}
2166}
2167
2168/*
2169 * Note: a response of 425 is not mentioned as a possible response to
2170 *	the PASV command in RFC959. However, it has been blessed as
2171 *	a legitimate response by Jon Postel in a telephone conversation
2172 *	with Rick Adams on 25 Jan 89.
2173 */
2174void
2175passive()
2176{
2177	int len, on;
2178	u_char *p, *a;
2179
2180	if (pw == NULL) {
2181		reply(530, "Please login with USER and PASS");
2182		return;
2183	}
2184	if (pdata >= 0)
2185		close(pdata);
2186	/*
2187	 * XXX
2188	 * At this point, it would be nice to have an algorithm that
2189	 * inserted a growing delay in an attack scenario.  Such a thing
2190	 * would look like continual passive sockets being opened, but
2191	 * nothing serious being done with them.  They're not used to
2192	 * move data; the entire attempt is just to use tcp FIN_WAIT
2193	 * resources.
2194	 */
2195	pdata = socket(AF_INET, SOCK_STREAM, 0);
2196	if (pdata < 0) {
2197		perror_reply(425, "Can't open passive connection");
2198		return;
2199	}
2200
2201#ifdef IP_PORTRANGE
2202	on = high_data_ports ? IP_PORTRANGE_HIGH : IP_PORTRANGE_DEFAULT;
2203	if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2204	    (char *)&on, sizeof(on)) < 0)
2205		goto pasv_error;
2206#endif
2207
2208	pasv_addr = ctrl_addr;
2209	pasv_addr.su_sin.sin_port = 0;
2210	if (bind(pdata, (struct sockaddr *)&pasv_addr,
2211		 pasv_addr.su_len) < 0)
2212		goto pasv_error;
2213
2214	len = sizeof(pasv_addr);
2215	if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
2216		goto pasv_error;
2217	if (listen(pdata, 1) < 0)
2218		goto pasv_error;
2219	a = (u_char *) &pasv_addr.su_sin.sin_addr;
2220	p = (u_char *) &pasv_addr.su_sin.sin_port;
2221
2222	reply(227, "Entering Passive Mode (%u,%u,%u,%u,%u,%u)", a[0],
2223	    a[1], a[2], a[3], p[0], p[1]);
2224	return;
2225
2226pasv_error:
2227	(void) seteuid((uid_t)pw->pw_uid);
2228	(void) close(pdata);
2229	pdata = -1;
2230	perror_reply(425, "Can't open passive connection");
2231	return;
2232}
2233
2234/*
2235 * convert protocol identifier to/from AF
2236 */
2237int
2238lpsvproto2af(int proto)
2239{
2240
2241	switch (proto) {
2242	case 4:	return AF_INET;
2243#ifdef INET6
2244	case 6:	return AF_INET6;
2245#endif
2246	default: return -1;
2247	}
2248}
2249
2250int
2251af2lpsvproto(int af)
2252{
2253
2254	switch (af) {
2255	case AF_INET:	return 4;
2256#ifdef INET6
2257	case AF_INET6:	return 6;
2258#endif
2259	default:	return -1;
2260	}
2261}
2262
2263int
2264epsvproto2af(int proto)
2265{
2266
2267	switch (proto) {
2268	case 1:	return AF_INET;
2269#ifdef INET6
2270	case 2:	return AF_INET6;
2271#endif
2272	default: return -1;
2273	}
2274}
2275
2276int
2277af2epsvproto(int af)
2278{
2279
2280	switch (af) {
2281	case AF_INET:	return 1;
2282#ifdef INET6
2283	case AF_INET6:	return 2;
2284#endif
2285	default:	return -1;
2286	}
2287}
2288
2289/*
2290 * 228 Entering Long Passive Mode (af, hal, h1, h2, h3,..., pal, p1, p2...)
2291 * 229 Entering Extended Passive Mode (|||port|)
2292 */
2293void
2294long_passive(char *cmd, int pf)
2295{
2296	int len, on;
2297	u_char *p, *a;
2298
2299	if (!logged_in) {
2300		syslog(LOG_NOTICE, "long passive but not logged in");
2301		reply(503, "Login with USER first.");
2302		return;
2303	}
2304
2305	if (pf != PF_UNSPEC && ctrl_addr.su_family != pf) {
2306		/*
2307		 * XXX
2308		 * only EPRT/EPSV ready clients will understand this
2309		 */
2310		if (strcmp(cmd, "EPSV") != 0)
2311			reply(501, "Network protocol mismatch"); /*XXX*/
2312		else
2313			epsv_protounsupp("Network protocol mismatch");
2314
2315		return;
2316	}
2317
2318	if (pdata >= 0)
2319		close(pdata);
2320	/*
2321	 * XXX
2322	 * At this point, it would be nice to have an algorithm that
2323	 * inserted a growing delay in an attack scenario.  Such a thing
2324	 * would look like continual passive sockets being opened, but
2325	 * nothing serious being done with them.  They not used to move
2326	 * data; the entire attempt is just to use tcp FIN_WAIT
2327	 * resources.
2328	 */
2329	pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2330	if (pdata < 0) {
2331		perror_reply(425, "Can't open passive connection");
2332		return;
2333	}
2334
2335	switch (ctrl_addr.su_family) {
2336	case AF_INET:
2337#ifdef IP_PORTRANGE
2338		on = high_data_ports ? IP_PORTRANGE_HIGH : IP_PORTRANGE_DEFAULT;
2339		if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2340		    (char *)&on, sizeof(on)) < 0)
2341			goto pasv_error;
2342#endif
2343		break;
2344	case AF_INET6:
2345#ifdef IPV6_PORTRANGE
2346		on = high_data_ports ? IPV6_PORTRANGE_HIGH
2347				     : IPV6_PORTRANGE_DEFAULT;
2348		if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2349		    (char *)&on, sizeof(on)) < 0)
2350			goto pasv_error;
2351#endif
2352		break;
2353	}
2354
2355	pasv_addr = ctrl_addr;
2356	pasv_addr.su_port = 0;
2357	(void) seteuid((uid_t) 0);
2358	if (bind(pdata, (struct sockaddr *) &pasv_addr, pasv_addr.su_len) < 0) {
2359		(void) seteuid((uid_t) pw->pw_uid);
2360		goto pasv_error;
2361	}
2362	(void) seteuid((uid_t) pw->pw_uid);
2363	len = pasv_addr.su_len;
2364	if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
2365		goto pasv_error;
2366	if (listen(pdata, 1) < 0)
2367		goto pasv_error;
2368	p = (u_char *) &pasv_addr.su_port;
2369
2370	if (strcmp(cmd, "LPSV") == 0) {
2371		switch (pasv_addr.su_family) {
2372		case AF_INET:
2373			a = (u_char *) &pasv_addr.su_sin.sin_addr;
2374			reply(228,
2375			    "Entering Long Passive Mode (%u,%u,%u,%u,%u,%u,%u,%u,%u)",
2376			    4, 4, a[0], a[1], a[2], a[3], 2, p[0], p[1]);
2377			return;
2378		case AF_INET6:
2379			a = (char *) &pasv_addr.su_sin6.sin6_addr;
2380			reply(228,
2381			    "Entering Long Passive Mode (%u,%u,%u,%u,%u,%u,"
2382			    "%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u)",
2383				6, 16, a[0], a[1], a[2], a[3], a[4],
2384				a[5], a[6], a[7], a[8], a[9], a[10],
2385				a[11], a[12], a[13], a[14], a[15],
2386				2, p[0], p[1]);
2387			return;
2388		}
2389	} else if (strcmp(cmd, "EPSV") == 0) {
2390		switch (pasv_addr.su_family) {
2391		case AF_INET:
2392		case AF_INET6:
2393			reply(229, "Entering Extended Passive Mode (|||%u|)",
2394			    ntohs(pasv_addr.su_port));
2395			return;
2396		}
2397	} else {
2398		/* more proper error code? */
2399	}
2400
2401  pasv_error:
2402	(void) close(pdata);
2403	pdata = -1;
2404	perror_reply(425, "Can't open passive connection");
2405	return;
2406}
2407
2408/*
2409 * EPRT |proto|addr|port|
2410 */
2411int
2412extended_port(const char *arg)
2413{
2414	char *tmp = NULL;
2415	char *result[3];
2416	char *p, *q;
2417	char delim;
2418	struct addrinfo hints;
2419	struct addrinfo *res = NULL;
2420	int i;
2421	unsigned long proto;
2422
2423	if (epsvall) {
2424		reply(501, "EPRT disallowed after EPSV ALL");
2425		return -1;
2426	}
2427
2428	usedefault = 0;
2429	if (pdata >= 0) {
2430		(void) close(pdata);
2431		pdata = -1;
2432	}
2433
2434	tmp = strdup(arg);
2435	if (!tmp) {
2436		fatal("not enough core.");
2437		/*NOTREACHED*/
2438	}
2439	p = tmp;
2440	delim = p[0];
2441	p++;
2442	memset(result, 0, sizeof(result));
2443	for (i = 0; i < 3; i++) {
2444		q = strchr(p, delim);
2445		if (!q || *q != delim)
2446			goto parsefail;
2447		*q++ = '\0';
2448		result[i] = p;
2449		p = q;
2450	}
2451
2452	/* some more sanity check */
2453	p = NULL;
2454	(void)strtoul(result[2], &p, 10);
2455	if (!*result[2] || *p)
2456		goto protounsupp;
2457	p = NULL;
2458	proto = strtoul(result[0], &p, 10);
2459	if (!*result[0] || *p)
2460		goto protounsupp;
2461
2462	memset(&hints, 0, sizeof(hints));
2463	hints.ai_family = epsvproto2af((int)proto);
2464	if (hints.ai_family < 0)
2465		goto protounsupp;
2466	hints.ai_socktype = SOCK_STREAM;
2467	hints.ai_flags = AI_NUMERICHOST;	/*no DNS*/
2468	if (getaddrinfo(result[1], result[2], &hints, &res))
2469		goto parsefail;
2470	if (res->ai_next)
2471		goto parsefail;
2472	if (sizeof(data_dest) < res->ai_addrlen)
2473		goto parsefail;
2474	memcpy(&data_dest, res->ai_addr, res->ai_addrlen);
2475	if (his_addr.su_family == AF_INET6 &&
2476	    data_dest.su_family == AF_INET6) {
2477		/* XXX more sanity checks! */
2478		data_dest.su_sin6.sin6_scope_id =
2479		    his_addr.su_sin6.sin6_scope_id;
2480	}
2481	if (pdata >= 0) {
2482		(void) close(pdata);
2483		pdata = -1;
2484	}
2485	reply(200, "EPRT command successful.");
2486
2487	if (tmp)
2488		free(tmp);
2489	if (res)
2490		freeaddrinfo(res);
2491	return 0;
2492
2493parsefail:
2494	reply(500, "Invalid argument, rejected.");
2495	usedefault = 1;
2496	if (tmp)
2497		free(tmp);
2498	if (res)
2499		freeaddrinfo(res);
2500	return -1;
2501
2502protounsupp:
2503	epsv_protounsupp("Protocol not supported");
2504	usedefault = 1;
2505	if (tmp)
2506		free(tmp);
2507	if (res)
2508		freeaddrinfo(res);
2509	return -1;
2510}
2511
2512/*
2513 * 522 Protocol not supported (proto,...)
2514 * as we assume address family for control and data connections are the same,
2515 * we do not return the list of address families we support - instead, we
2516 * return the address family of the control connection.
2517 */
2518void
2519epsv_protounsupp(const char *message)
2520{
2521	int proto;
2522
2523	proto = af2epsvproto(ctrl_addr.su_family);
2524	if (proto < 0)
2525		reply(501, "%s", message);	/*XXX*/
2526	else
2527		reply(522, "%s, use (%d)", message, proto);
2528}
2529
2530/*
2531 * Generate unique name for file with basename "local".
2532 * The file named "local" is already known to exist.
2533 * Generates failure reply on error.
2534 */
2535static int
2536guniquefd(local, nam)
2537	char *local;
2538	char **nam;
2539{
2540	static char new[MAXPATHLEN];
2541	struct stat st;
2542	int count, len, fd;
2543	char *cp;
2544
2545	cp = strrchr(local, '/');
2546	if (cp)
2547		*cp = '\0';
2548	if (stat(cp ? local : ".", &st) < 0) {
2549		perror_reply(553, cp ? local : ".");
2550		return (-1);
2551	}
2552	if (cp)
2553		*cp = '/';
2554	len = strlcpy(new, local, sizeof(new));
2555	if (len+2+1 >= sizeof(new)-1)
2556		return (-1);
2557	cp = new + len;
2558	*cp++ = '.';
2559	for (count = 1; count < 100; count++) {
2560		(void)snprintf(cp, sizeof(new) - (cp - new), "%d", count);
2561		fd = open(new, O_RDWR|O_CREAT|O_EXCL, 0666);
2562		if (fd == -1)
2563			continue;
2564		if (nam)
2565			*nam = new;
2566		return (fd);
2567	}
2568	reply(452, "Unique file name cannot be created.");
2569	return (-1);
2570}
2571
2572/*
2573 * Format and send reply containing system error number.
2574 */
2575void
2576perror_reply(code, string)
2577	int code;
2578	char *string;
2579{
2580
2581	reply(code, "%s: %s.", string, strerror(errno));
2582}
2583
2584static char *onefile[] = {
2585	"",
2586	0
2587};
2588
2589void
2590send_file_list(whichf)
2591	char *whichf;
2592{
2593	struct stat st;
2594	DIR *dirp = NULL;
2595	struct dirent *dir;
2596	FILE *dout = NULL;
2597	char **dirlist;
2598	char *dirname;
2599	int simple = 0;
2600	volatile int freeglob = 0;
2601	glob_t gl;
2602
2603	if (strpbrk(whichf, "~{[*?") != NULL) {
2604		memset(&gl, 0, sizeof(gl));
2605		freeglob = 1;
2606		if (glob(whichf,
2607		    GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE|GLOB_LIMIT,
2608		    0, &gl)) {
2609			reply(550, "not found");
2610			goto out;
2611		} else if (gl.gl_pathc == 0) {
2612			errno = ENOENT;
2613			perror_reply(550, whichf);
2614			goto out;
2615		}
2616		dirlist = gl.gl_pathv;
2617	} else {
2618		onefile[0] = whichf;
2619		dirlist = onefile;
2620		simple = 1;
2621	}
2622
2623	while ((dirname = *dirlist++)) {
2624		if (stat(dirname, &st) < 0) {
2625			/*
2626			 * If user typed "ls -l", etc, and the client
2627			 * used NLST, do what the user meant.
2628			 */
2629			if (dirname[0] == '-' && *dirlist == NULL &&
2630			    transflag == 0) {
2631				retrieve("/bin/ls %s", dirname);
2632				goto out;
2633			}
2634			perror_reply(550, whichf);
2635			if (dout != NULL) {
2636				(void) fclose(dout);
2637				transflag = 0;
2638				data = -1;
2639				pdata = -1;
2640			}
2641			goto out;
2642		}
2643
2644		if (S_ISREG(st.st_mode)) {
2645			if (dout == NULL) {
2646				dout = dataconn("file list", (off_t)-1, "w");
2647				if (dout == NULL)
2648					goto out;
2649				transflag++;
2650			}
2651			fprintf(dout, "%s%s\n", dirname,
2652				type == TYPE_A ? "\r" : "");
2653			byte_count += strlen(dirname) + 1;
2654			continue;
2655		} else if (!S_ISDIR(st.st_mode))
2656			continue;
2657
2658		if ((dirp = opendir(dirname)) == NULL)
2659			continue;
2660
2661		while ((dir = readdir(dirp)) != NULL) {
2662			char nbuf[MAXPATHLEN];
2663
2664			if (recvurg) {
2665				myoob();
2666				recvurg = 0;
2667				transflag = 0;
2668				goto out;
2669			}
2670
2671			if (dir->d_name[0] == '.' && dir->d_namlen == 1)
2672				continue;
2673			if (dir->d_name[0] == '.' && dir->d_name[1] == '.' &&
2674			    dir->d_namlen == 2)
2675				continue;
2676
2677			snprintf(nbuf, sizeof(nbuf), "%s/%s", dirname,
2678				 dir->d_name);
2679
2680			/*
2681			 * We have to do a stat to insure it's
2682			 * not a directory or special file.
2683			 */
2684			if (simple || (stat(nbuf, &st) == 0 &&
2685			    S_ISREG(st.st_mode))) {
2686				if (dout == NULL) {
2687					dout = dataconn("file list", (off_t)-1,
2688						"w");
2689					if (dout == NULL)
2690						goto out;
2691					transflag++;
2692				}
2693				if (nbuf[0] == '.' && nbuf[1] == '/')
2694					fprintf(dout, "%s%s\n", &nbuf[2],
2695						type == TYPE_A ? "\r" : "");
2696				else
2697					fprintf(dout, "%s%s\n", nbuf,
2698						type == TYPE_A ? "\r" : "");
2699				byte_count += strlen(nbuf) + 1;
2700			}
2701		}
2702		(void) closedir(dirp);
2703	}
2704
2705	if (dout == NULL)
2706		reply(550, "No files found.");
2707	else if (ferror(dout) != 0)
2708		perror_reply(550, "Data connection");
2709	else
2710		reply(226, "Transfer complete.");
2711
2712	transflag = 0;
2713	if (dout != NULL)
2714		(void) fclose(dout);
2715	else {
2716		if (pdata >= 0)
2717			close(pdata);
2718	}
2719	data = -1;
2720	pdata = -1;
2721out:
2722	if (freeglob) {
2723		freeglob = 0;
2724		globfree(&gl);
2725	}
2726}
2727
2728static void
2729reapchild(signo)
2730	int signo;
2731{
2732	int save_errno = errno;
2733	int rval;
2734
2735	do {
2736		rval = waitpid(-1, NULL, WNOHANG);
2737	} while (rval > 0 || (rval == -1 && errno == EINTR));
2738	errno = save_errno;
2739}
2740
2741void
2742logxfer(name, size, start)
2743	char *name;
2744	off_t size;
2745	time_t start;
2746{
2747	char buf[400 + MAXHOSTNAMELEN*4 + MAXPATHLEN*4];
2748	char dir[MAXPATHLEN], path[MAXPATHLEN], rpath[MAXPATHLEN];
2749	char vremotehost[MAXHOSTNAMELEN*4], vpath[MAXPATHLEN*4];
2750	char *vpw;
2751	time_t now;
2752	int len;
2753
2754	if ((statfd >= 0) && (getcwd(dir, sizeof(dir)) != NULL)) {
2755		time(&now);
2756
2757		vpw = malloc(strlen(guest ? guestpw : pw->pw_name) * 4 + 1);
2758		if (vpw == NULL)
2759			return;
2760
2761		snprintf(path, sizeof(path), "%s/%s", dir, name);
2762		if (realpath(path, rpath) == NULL)
2763			strlcpy(rpath, path, sizeof(rpath));
2764		strvis(vpath, rpath, VIS_SAFE|VIS_NOSLASH);
2765
2766		strvis(vremotehost, remotehost, VIS_SAFE|VIS_NOSLASH);
2767		strvis(vpw, guest? guestpw : pw->pw_name, VIS_SAFE|VIS_NOSLASH);
2768
2769		len = snprintf(buf, sizeof(buf),
2770		    "%.24s %d %s %qd %s %c %s %c %c %s ftp %d %s %s\n",
2771		    ctime(&now), now - start + (now == start),
2772		    vremotehost, (long long) size, vpath,
2773		    ((type == TYPE_A) ? 'a' : 'b'), "*" /* none yet */,
2774		    'o', ((guest) ? 'a' : 'r'),
2775		    vpw, 0 /* none yet */,
2776		    ((guest) ? "*" : pw->pw_name), dhostname);
2777		if (len >= sizeof(buf)) {
2778			len = sizeof(buf);
2779			buf[sizeof(buf) - 1] = '\n';
2780		}
2781		write(statfd, buf, len);
2782		free(vpw);
2783	}
2784}
2785
2786#if defined(TCPWRAPPERS)
2787static int
2788check_host(sa)
2789	struct sockaddr *sa;
2790{
2791	struct sockaddr_in *sin;
2792	struct hostent *hp;
2793	char *addr;
2794
2795	if (sa->sa_family != AF_INET)
2796		return 1;	/*XXX*/
2797
2798	sin = (struct sockaddr_in *)sa;
2799	hp = gethostbyaddr((char *)&sin->sin_addr,
2800	    sizeof(struct in_addr), AF_INET);
2801	addr = inet_ntoa(sin->sin_addr);
2802	if (hp) {
2803		if (!hosts_ctl("ftpd", hp->h_name, addr, STRING_UNKNOWN)) {
2804			syslog(LOG_NOTICE, "tcpwrappers rejected: %s [%s]",
2805			    hp->h_name, addr);
2806			return (0);
2807		}
2808	} else {
2809		if (!hosts_ctl("ftpd", STRING_UNKNOWN, addr, STRING_UNKNOWN)) {
2810			syslog(LOG_NOTICE, "tcpwrappers rejected: [%s]", addr);
2811			return (0);
2812		}
2813	}
2814	return (1);
2815}
2816#endif	/* TCPWRAPPERS */
2817
2818/*
2819 * Allocate space and return a copy of the specified dir.
2820 * If 'dir' begins with a tilde (~), expand it.
2821 */
2822char *
2823copy_dir(dir, pw)
2824	char *dir;
2825	struct passwd *pw;
2826{
2827	char *cp;
2828	char *newdir;
2829	char *user = NULL;
2830	size_t dirsiz;
2831
2832	/* Nothing to expand */
2833	if (dir[0] !=  '~')
2834		return (strdup(dir));
2835
2836	/* "dir" is of form ~user/some/dir, lookup user. */
2837	if (dir[1] != '/' && dir[1] != '\0') {
2838		if ((cp = strchr(dir + 1, '/')) == NULL)
2839		    cp = dir + strlen(dir);
2840		if ((user = malloc(cp - dir)) == NULL)
2841			return (NULL);
2842		strlcpy(user, dir + 1, cp - dir);
2843
2844		/* Only do lookup if it is a different user. */
2845		if (strcmp(user, pw->pw_name) != 0) {
2846			if ((pw = getpwnam(user)) == NULL) {
2847				/* No such user, interpret literally */
2848				free(user);
2849				return(strdup(dir));
2850			}
2851		}
2852	}
2853
2854	/*
2855	 * If there is no directory separator (/) then it is just pw_dir.
2856	 * Otherwise, replace ~foo with  pw_dir.
2857	 */
2858	if ((cp = strchr(dir + 1, '/')) == NULL) {
2859		newdir = strdup(pw->pw_dir);
2860	} else {
2861		dirsiz = strlen(cp) + strlen(pw->pw_dir) + 1;
2862		if ((newdir = malloc(dirsiz)) == NULL)
2863			return (NULL);
2864		strcpy(newdir, pw->pw_dir);
2865		strcat(newdir, cp);
2866	}
2867
2868	if (user)
2869		free(user);
2870	return(newdir);
2871}
2872