xref: /freebsd/libexec/ftpd/ftpd.c (revision e20971500194d2f7299e9d01ca3b20e9bc6b4009)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1985, 1988, 1990, 1992, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*
33  * FTP server.
34  */
35 #include <sys/param.h>
36 #include <sys/ioctl.h>
37 #include <sys/mman.h>
38 #include <sys/socket.h>
39 #include <sys/stat.h>
40 #include <sys/time.h>
41 #include <sys/wait.h>
42 
43 #include <netinet/in.h>
44 #include <netinet/in_systm.h>
45 #include <netinet/ip.h>
46 #include <netinet/tcp.h>
47 
48 #define	FTP_NAMES
49 #include <arpa/ftp.h>
50 #include <arpa/inet.h>
51 #include <arpa/telnet.h>
52 
53 #include <ctype.h>
54 #include <dirent.h>
55 #include <err.h>
56 #include <errno.h>
57 #include <fcntl.h>
58 #include <glob.h>
59 #include <limits.h>
60 #include <netdb.h>
61 #include <pwd.h>
62 #include <grp.h>
63 #include <signal.h>
64 #include <stdint.h>
65 #include <stdio.h>
66 #include <stdlib.h>
67 #include <string.h>
68 #include <syslog.h>
69 #include <time.h>
70 #include <unistd.h>
71 #include <libutil.h>
72 #ifdef	LOGIN_CAP
73 #include <login_cap.h>
74 #endif
75 
76 #ifdef USE_PAM
77 #include <security/pam_appl.h>
78 #endif
79 
80 #include "blacklist_client.h"
81 #include "pathnames.h"
82 #include "extern.h"
83 
84 #include <stdarg.h>
85 
86 static char version[] = "Version 6.00LS";
87 #undef main
88 
89 union sockunion ctrl_addr;
90 union sockunion data_source;
91 union sockunion data_dest;
92 union sockunion his_addr;
93 union sockunion pasv_addr;
94 
95 int	daemon_mode;
96 int	data;
97 int	dataport;
98 int	hostinfo = 1;	/* print host-specific info in messages */
99 int	logged_in;
100 struct	passwd *pw;
101 char	*homedir;
102 int	ftpdebug;
103 int	timeout = 900;    /* timeout after 15 minutes of inactivity */
104 int	maxtimeout = 7200;/* don't allow idle time to be set beyond 2 hours */
105 int	logging;
106 int	restricted_data_ports = 1;
107 int	paranoid = 1;	  /* be extra careful about security */
108 int	anon_only = 0;    /* Only anonymous ftp allowed */
109 int	assumeutf8 = 0;   /* Assume that server file names are in UTF-8 */
110 int	guest;
111 int	dochroot;
112 char	*chrootdir;
113 int	dowtmp = 1;
114 int	stats;
115 int	statfd = -1;
116 int	type;
117 int	form;
118 int	stru;			/* avoid C keyword */
119 int	mode;
120 int	usedefault = 1;		/* for data transfers */
121 int	pdata = -1;		/* for passive mode */
122 int	readonly = 0;		/* Server is in readonly mode.	*/
123 int	noepsv = 0;		/* EPSV command is disabled.	*/
124 int	noretr = 0;		/* RETR command is disabled.	*/
125 int	noguestretr = 0;	/* RETR command is disabled for anon users. */
126 int	noguestmkd = 0;		/* MKD command is disabled for anon users. */
127 int	noguestmod = 1;		/* anon users may not modify existing files. */
128 int	use_blacklist = 0;
129 
130 off_t	file_size;
131 off_t	byte_count;
132 #if !defined(CMASK) || CMASK == 0
133 #undef CMASK
134 #define CMASK 027
135 #endif
136 int	defumask = CMASK;		/* default umask value */
137 char	tmpline[7];
138 char	*hostname;
139 int	epsvall = 0;
140 
141 #ifdef VIRTUAL_HOSTING
142 char	*ftpuser;
143 
144 static struct ftphost {
145 	struct ftphost	*next;
146 	struct addrinfo *hostinfo;
147 	char		*hostname;
148 	char		*anonuser;
149 	char		*statfile;
150 	char		*welcome;
151 	char		*loginmsg;
152 } *thishost, *firsthost;
153 
154 #endif
155 char	remotehost[NI_MAXHOST];
156 char	*ident = NULL;
157 
158 static char	wtmpid[20];
159 
160 #ifdef USE_PAM
161 static int	auth_pam(struct passwd**, const char*);
162 pam_handle_t	*pamh = NULL;
163 #endif
164 
165 char	*pid_file = NULL; /* means default location to pidfile(3) */
166 
167 /*
168  * Limit number of pathnames that glob can return.
169  * A limit of 0 indicates the number of pathnames is unlimited.
170  */
171 #define MAXGLOBARGS	16384
172 #
173 
174 /*
175  * Timeout intervals for retrying connections
176  * to hosts that don't accept PORT cmds.  This
177  * is a kludge, but given the problems with TCP...
178  */
179 #define	SWAITMAX	90	/* wait at most 90 seconds */
180 #define	SWAITINT	5	/* interval between retries */
181 
182 int	swaitmax = SWAITMAX;
183 int	swaitint = SWAITINT;
184 
185 #ifdef SETPROCTITLE
186 char	proctitle[LINE_MAX];	/* initial part of title */
187 #endif /* SETPROCTITLE */
188 
189 #define LOGCMD(cmd, file)		logcmd((cmd), (file), NULL, -1)
190 #define LOGCMD2(cmd, file1, file2)	logcmd((cmd), (file1), (file2), -1)
191 #define LOGBYTES(cmd, file, cnt)	logcmd((cmd), (file), NULL, (cnt))
192 
193 static	volatile sig_atomic_t recvurg;
194 static	int transflag;		/* NB: for debugging only */
195 
196 #define STARTXFER	flagxfer(1)
197 #define ENDXFER		flagxfer(0)
198 
199 #define START_UNSAFE	maskurg(1)
200 #define END_UNSAFE	maskurg(0)
201 
202 /* It's OK to put an `else' clause after this macro. */
203 #define CHECKOOB(action)						\
204 	if (recvurg) {							\
205 		recvurg = 0;						\
206 		if (myoob()) {						\
207 			ENDXFER;					\
208 			action;						\
209 		}							\
210 	}
211 
212 #ifdef VIRTUAL_HOSTING
213 static void	 inithosts(int);
214 static void	 selecthost(union sockunion *);
215 #endif
216 static void	 ack(char *);
217 static void	 sigurg(int);
218 static void	 maskurg(int);
219 static void	 flagxfer(int);
220 static int	 myoob(void);
221 static int	 checkuser(char *, char *, int, char **, int *);
222 static FILE	*dataconn(char *, off_t, char *);
223 static void	 dolog(struct sockaddr *);
224 static void	 end_login(void);
225 static FILE	*getdatasock(char *);
226 static int	 guniquefd(char *, char **);
227 static void	 lostconn(int);
228 static void	 sigquit(int);
229 static int	 receive_data(FILE *, FILE *);
230 static int	 send_data(FILE *, FILE *, size_t, off_t, int);
231 static struct passwd *
232 		 sgetpwnam(char *);
233 static char	*sgetsave(char *);
234 static void	 reapchild(int);
235 static void	 appendf(char **, char *, ...) __printflike(2, 3);
236 static void	 logcmd(char *, char *, char *, off_t);
237 static void      logxfer(char *, off_t, time_t);
238 static char	*doublequote(char *);
239 static int	*socksetup(int, char *, const char *);
240 
241 int
main(int argc,char * argv[],char ** envp)242 main(int argc, char *argv[], char **envp)
243 {
244 	socklen_t addrlen;
245 	int ch, on = 1, tos, s = STDIN_FILENO;
246 	char *cp, line[LINE_MAX];
247 	FILE *fd;
248 	char	*bindname = NULL;
249 	const char *bindport = "ftp";
250 	int	family = AF_UNSPEC;
251 	struct sigaction sa;
252 
253 	tzset();		/* in case no timezone database in ~ftp */
254 	sigemptyset(&sa.sa_mask);
255 	sa.sa_flags = SA_RESTART;
256 
257 	/*
258 	 * Prevent diagnostic messages from appearing on stderr.
259 	 * We run as a daemon or from inetd; in both cases, there's
260 	 * more reason in logging to syslog.
261 	 */
262 	(void) freopen(_PATH_DEVNULL, "w", stderr);
263 	opterr = 0;
264 
265 	/*
266 	 * LOG_NDELAY sets up the logging connection immediately,
267 	 * necessary for anonymous ftp's that chroot and can't do it later.
268 	 */
269 	openlog("ftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
270 
271 	while ((ch = getopt(argc, argv,
272 	                    "468a:ABdDEhlmMoOp:P:rRSt:T:u:UvW")) != -1) {
273 		switch (ch) {
274 		case '4':
275 			family = (family == AF_INET6) ? AF_UNSPEC : AF_INET;
276 			break;
277 
278 		case '6':
279 			family = (family == AF_INET) ? AF_UNSPEC : AF_INET6;
280 			break;
281 
282 		case '8':
283 			assumeutf8 = 1;
284 			break;
285 
286 		case 'a':
287 			bindname = optarg;
288 			break;
289 
290 		case 'A':
291 			anon_only = 1;
292 			break;
293 
294 		case 'B':
295 #ifdef USE_BLACKLIST
296 			use_blacklist = 1;
297 #else
298 			syslog(LOG_WARNING, "not compiled with USE_BLACKLIST support");
299 #endif
300 			break;
301 
302 		case 'd':
303 			ftpdebug++;
304 			break;
305 
306 		case 'D':
307 			daemon_mode++;
308 			break;
309 
310 		case 'E':
311 			noepsv = 1;
312 			break;
313 
314 		case 'h':
315 			hostinfo = 0;
316 			break;
317 
318 		case 'l':
319 			logging++;	/* > 1 == extra logging */
320 			break;
321 
322 		case 'm':
323 			noguestmod = 0;
324 			break;
325 
326 		case 'M':
327 			noguestmkd = 1;
328 			break;
329 
330 		case 'o':
331 			noretr = 1;
332 			break;
333 
334 		case 'O':
335 			noguestretr = 1;
336 			break;
337 
338 		case 'p':
339 			pid_file = optarg;
340 			break;
341 
342 		case 'P':
343 			bindport = optarg;
344 			break;
345 
346 		case 'r':
347 			readonly = 1;
348 			break;
349 
350 		case 'R':
351 			paranoid = 0;
352 			break;
353 
354 		case 'S':
355 			stats++;
356 			break;
357 
358 		case 't':
359 			timeout = atoi(optarg);
360 			if (maxtimeout < timeout)
361 				maxtimeout = timeout;
362 			break;
363 
364 		case 'T':
365 			maxtimeout = atoi(optarg);
366 			if (timeout > maxtimeout)
367 				timeout = maxtimeout;
368 			break;
369 
370 		case 'u':
371 		    {
372 			long val = 0;
373 
374 			val = strtol(optarg, &optarg, 8);
375 			if (*optarg != '\0' || val < 0)
376 				syslog(LOG_WARNING, "bad value for -u");
377 			else
378 				defumask = val;
379 			break;
380 		    }
381 		case 'U':
382 			restricted_data_ports = 0;
383 			break;
384 
385 		case 'v':
386 			ftpdebug++;
387 			break;
388 
389 		case 'W':
390 			dowtmp = 0;
391 			break;
392 
393 		default:
394 			syslog(LOG_WARNING, "unknown flag -%c ignored", optopt);
395 			break;
396 		}
397 	}
398 
399 	/* handle filesize limit gracefully */
400 	sa.sa_handler = SIG_IGN;
401 	(void)sigaction(SIGXFSZ, &sa, NULL);
402 
403 	if (daemon_mode) {
404 		int *ctl_sock, fd, maxfd = -1, nfds, i;
405 		fd_set defreadfds, readfds;
406 		pid_t pid;
407 		struct pidfh *pfh;
408 
409 		if ((pfh = pidfile_open(pid_file, 0600, &pid)) == NULL) {
410 			if (errno == EEXIST) {
411 				syslog(LOG_ERR, "%s already running, pid %d",
412 				       getprogname(), (int)pid);
413 				exit(1);
414 			}
415 			syslog(LOG_WARNING, "pidfile_open: %m");
416 		}
417 
418 		/*
419 		 * Detach from parent.
420 		 */
421 		if (daemon(1, 1) < 0) {
422 			syslog(LOG_ERR, "failed to become a daemon");
423 			exit(1);
424 		}
425 
426 		if (pfh != NULL && pidfile_write(pfh) == -1)
427 			syslog(LOG_WARNING, "pidfile_write: %m");
428 
429 		sa.sa_handler = reapchild;
430 		(void)sigaction(SIGCHLD, &sa, NULL);
431 
432 #ifdef VIRTUAL_HOSTING
433 		inithosts(family);
434 #endif
435 
436 		/*
437 		 * Open a socket, bind it to the FTP port, and start
438 		 * listening.
439 		 */
440 		ctl_sock = socksetup(family, bindname, bindport);
441 		if (ctl_sock == NULL)
442 			exit(1);
443 
444 		FD_ZERO(&defreadfds);
445 		for (i = 1; i <= *ctl_sock; i++) {
446 			FD_SET(ctl_sock[i], &defreadfds);
447 			if (listen(ctl_sock[i], 32) < 0) {
448 				syslog(LOG_ERR, "control listen: %m");
449 				exit(1);
450 			}
451 			if (maxfd < ctl_sock[i])
452 				maxfd = ctl_sock[i];
453 		}
454 
455 		/*
456 		 * Loop forever accepting connection requests and forking off
457 		 * children to handle them.
458 		 */
459 		while (1) {
460 			FD_COPY(&defreadfds, &readfds);
461 			nfds = select(maxfd + 1, &readfds, NULL, NULL, 0);
462 			if (nfds <= 0) {
463 				if (nfds < 0 && errno != EINTR)
464 					syslog(LOG_WARNING, "select: %m");
465 				continue;
466 			}
467 
468 			pid = -1;
469                         for (i = 1; i <= *ctl_sock; i++)
470 				if (FD_ISSET(ctl_sock[i], &readfds)) {
471 					addrlen = sizeof(his_addr);
472 					fd = accept(ctl_sock[i],
473 					    (struct sockaddr *)&his_addr,
474 					    &addrlen);
475 					if (fd == -1) {
476 						syslog(LOG_WARNING,
477 						       "accept: %m");
478 						continue;
479 					}
480 					switch (pid = fork()) {
481 					case 0:
482 						/* child */
483 						(void) dup2(fd, s);
484 						(void) dup2(fd, STDOUT_FILENO);
485 						(void) close(fd);
486 						for (i = 1; i <= *ctl_sock; i++)
487 							close(ctl_sock[i]);
488 						if (pfh != NULL)
489 							pidfile_close(pfh);
490 						goto gotchild;
491 					case -1:
492 						syslog(LOG_WARNING, "fork: %m");
493 						/* FALLTHROUGH */
494 					default:
495 						close(fd);
496 					}
497 				}
498 		}
499 	} else {
500 		addrlen = sizeof(his_addr);
501 		if (getpeername(s, (struct sockaddr *)&his_addr, &addrlen) < 0) {
502 			syslog(LOG_ERR, "getpeername (%s): %m",argv[0]);
503 			exit(1);
504 		}
505 
506 #ifdef VIRTUAL_HOSTING
507 		if (his_addr.su_family == AF_INET6 &&
508 		    IN6_IS_ADDR_V4MAPPED(&his_addr.su_sin6.sin6_addr))
509 			family = AF_INET;
510 		else
511 			family = his_addr.su_family;
512 		inithosts(family);
513 #endif
514 	}
515 
516 gotchild:
517 	sa.sa_handler = SIG_DFL;
518 	(void)sigaction(SIGCHLD, &sa, NULL);
519 
520 	sa.sa_handler = sigurg;
521 	sa.sa_flags = 0;		/* don't restart syscalls for SIGURG */
522 	(void)sigaction(SIGURG, &sa, NULL);
523 
524 	sigfillset(&sa.sa_mask);	/* block all signals in handler */
525 	sa.sa_flags = SA_RESTART;
526 	sa.sa_handler = sigquit;
527 	(void)sigaction(SIGHUP, &sa, NULL);
528 	(void)sigaction(SIGINT, &sa, NULL);
529 	(void)sigaction(SIGQUIT, &sa, NULL);
530 	(void)sigaction(SIGTERM, &sa, NULL);
531 
532 	sa.sa_handler = lostconn;
533 	(void)sigaction(SIGPIPE, &sa, NULL);
534 
535 	addrlen = sizeof(ctrl_addr);
536 	if (getsockname(s, (struct sockaddr *)&ctrl_addr, &addrlen) < 0) {
537 		syslog(LOG_ERR, "getsockname (%s): %m",argv[0]);
538 		exit(1);
539 	}
540 	dataport = ntohs(ctrl_addr.su_port) - 1; /* as per RFC 959 */
541 #ifdef VIRTUAL_HOSTING
542 	/* select our identity from virtual host table */
543 	selecthost(&ctrl_addr);
544 #endif
545 #ifdef IP_TOS
546 	if (ctrl_addr.su_family == AF_INET)
547       {
548 	tos = IPTOS_LOWDELAY;
549 	if (setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
550 		syslog(LOG_WARNING, "control setsockopt (IP_TOS): %m");
551       }
552 #endif
553 	/*
554 	 * Disable Nagle on the control channel so that we don't have to wait
555 	 * for peer's ACK before issuing our next reply.
556 	 */
557 	if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) < 0)
558 		syslog(LOG_WARNING, "control setsockopt (TCP_NODELAY): %m");
559 
560 	data_source.su_port = htons(ntohs(ctrl_addr.su_port) - 1);
561 
562 	(void)snprintf(wtmpid, sizeof(wtmpid), "%xftpd", getpid());
563 
564 	/* Try to handle urgent data inline */
565 #ifdef SO_OOBINLINE
566 	if (setsockopt(s, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on)) < 0)
567 		syslog(LOG_WARNING, "control setsockopt (SO_OOBINLINE): %m");
568 #endif
569 
570 #ifdef	F_SETOWN
571 	if (fcntl(s, F_SETOWN, getpid()) == -1)
572 		syslog(LOG_ERR, "fcntl F_SETOWN: %m");
573 #endif
574 	dolog((struct sockaddr *)&his_addr);
575 	/*
576 	 * Set up default state
577 	 */
578 	data = -1;
579 	type = TYPE_A;
580 	form = FORM_N;
581 	stru = STRU_F;
582 	mode = MODE_S;
583 	tmpline[0] = '\0';
584 
585 	/* If logins are disabled, print out the message. */
586 	if ((fd = fopen(_PATH_NOLOGIN,"r")) != NULL) {
587 		while (fgets(line, sizeof(line), fd) != NULL) {
588 			if ((cp = strchr(line, '\n')) != NULL)
589 				*cp = '\0';
590 			lreply(530, "%s", line);
591 		}
592 		(void) fflush(stdout);
593 		(void) fclose(fd);
594 		reply(530, "System not available.");
595 		exit(0);
596 	}
597 #ifdef VIRTUAL_HOSTING
598 	fd = fopen(thishost->welcome, "r");
599 #else
600 	fd = fopen(_PATH_FTPWELCOME, "r");
601 #endif
602 	if (fd != NULL) {
603 		while (fgets(line, sizeof(line), fd) != NULL) {
604 			if ((cp = strchr(line, '\n')) != NULL)
605 				*cp = '\0';
606 			lreply(220, "%s", line);
607 		}
608 		(void) fflush(stdout);
609 		(void) fclose(fd);
610 		/* reply(220,) must follow */
611 	}
612 #ifndef VIRTUAL_HOSTING
613 	if ((hostname = malloc(MAXHOSTNAMELEN)) == NULL)
614 		fatalerror("Ran out of memory.");
615 	if (gethostname(hostname, MAXHOSTNAMELEN - 1) < 0)
616 		hostname[0] = '\0';
617 	hostname[MAXHOSTNAMELEN - 1] = '\0';
618 #endif
619 	if (hostinfo)
620 		reply(220, "%s FTP server (%s) ready.", hostname, version);
621 	else
622 		reply(220, "FTP server ready.");
623 	BLACKLIST_INIT();
624 	for (;;)
625 		(void) yyparse();
626 	/* NOTREACHED */
627 }
628 
629 static void
lostconn(int signo)630 lostconn(int signo)
631 {
632 
633 	if (ftpdebug)
634 		syslog(LOG_DEBUG, "lost connection");
635 	dologout(1);
636 }
637 
638 static void
sigquit(int signo)639 sigquit(int signo)
640 {
641 
642 	syslog(LOG_ERR, "got signal %d", signo);
643 	dologout(1);
644 }
645 
646 #ifdef VIRTUAL_HOSTING
647 /*
648  * read in virtual host tables (if they exist)
649  */
650 
651 static void
inithosts(int family)652 inithosts(int family)
653 {
654 	int insert;
655 	size_t len;
656 	FILE *fp;
657 	char *cp, *mp, *line;
658 	char *hostname;
659 	char *vhost, *anonuser, *statfile, *welcome, *loginmsg;
660 	struct ftphost *hrp, *lhrp;
661 	struct addrinfo hints, *res, *ai;
662 
663 	/*
664 	 * Fill in the default host information
665 	 */
666 	if ((hostname = malloc(MAXHOSTNAMELEN)) == NULL)
667 		fatalerror("Ran out of memory.");
668 	if (gethostname(hostname, MAXHOSTNAMELEN - 1) < 0)
669 		hostname[0] = '\0';
670 	hostname[MAXHOSTNAMELEN - 1] = '\0';
671 	if ((hrp = malloc(sizeof(struct ftphost))) == NULL)
672 		fatalerror("Ran out of memory.");
673 	hrp->hostname = hostname;
674 	hrp->hostinfo = NULL;
675 
676 	memset(&hints, 0, sizeof(hints));
677 	hints.ai_flags = AI_PASSIVE;
678 	hints.ai_family = family;
679 	hints.ai_socktype = SOCK_STREAM;
680 	if (getaddrinfo(hrp->hostname, NULL, &hints, &res) == 0)
681 		hrp->hostinfo = res;
682 	hrp->statfile = _PATH_FTPDSTATFILE;
683 	hrp->welcome  = _PATH_FTPWELCOME;
684 	hrp->loginmsg = _PATH_FTPLOGINMESG;
685 	hrp->anonuser = "ftp";
686 	hrp->next = NULL;
687 	thishost = firsthost = lhrp = hrp;
688 	if ((fp = fopen(_PATH_FTPHOSTS, "r")) != NULL) {
689 		int addrsize, gothost;
690 		void *addr;
691 		struct hostent *hp;
692 
693 		while ((line = fgetln(fp, &len)) != NULL) {
694 			int	i, hp_error;
695 
696 			/* skip comments */
697 			if (line[0] == '#')
698 				continue;
699 			if (line[len - 1] == '\n') {
700 				line[len - 1] = '\0';
701 				mp = NULL;
702 			} else {
703 				if ((mp = malloc(len + 1)) == NULL)
704 					fatalerror("Ran out of memory.");
705 				memcpy(mp, line, len);
706 				mp[len] = '\0';
707 				line = mp;
708 			}
709 			cp = strtok(line, " \t");
710 			/* skip empty lines */
711 			if (cp == NULL)
712 				goto nextline;
713 			vhost = cp;
714 
715 			/* set defaults */
716 			anonuser = "ftp";
717 			statfile = _PATH_FTPDSTATFILE;
718 			welcome  = _PATH_FTPWELCOME;
719 			loginmsg = _PATH_FTPLOGINMESG;
720 
721 			/*
722 			 * Preparse the line so we can use its info
723 			 * for all the addresses associated with
724 			 * the virtual host name.
725 			 * Field 0, the virtual host name, is special:
726 			 * it's already parsed off and will be strdup'ed
727 			 * later, after we know its canonical form.
728 			 */
729 			for (i = 1; i < 5 && (cp = strtok(NULL, " \t")); i++)
730 				if (*cp != '-' && (cp = strdup(cp)))
731 					switch (i) {
732 					case 1:	/* anon user permissions */
733 						anonuser = cp;
734 						break;
735 					case 2: /* statistics file */
736 						statfile = cp;
737 						break;
738 					case 3: /* welcome message */
739 						welcome  = cp;
740 						break;
741 					case 4: /* login message */
742 						loginmsg = cp;
743 						break;
744 					default: /* programming error */
745 						abort();
746 						/* NOTREACHED */
747 					}
748 
749 			hints.ai_flags = AI_PASSIVE;
750 			hints.ai_family = family;
751 			hints.ai_socktype = SOCK_STREAM;
752 			if (getaddrinfo(vhost, NULL, &hints, &res) != 0)
753 				goto nextline;
754 			for (ai = res; ai != NULL && ai->ai_addr != NULL;
755 			     ai = ai->ai_next) {
756 
757 			gothost = 0;
758 			for (hrp = firsthost; hrp != NULL; hrp = hrp->next) {
759 				struct addrinfo *hi;
760 
761 				for (hi = hrp->hostinfo; hi != NULL;
762 				     hi = hi->ai_next)
763 					if (hi->ai_addrlen == ai->ai_addrlen &&
764 					    memcmp(hi->ai_addr,
765 						   ai->ai_addr,
766 						   ai->ai_addr->sa_len) == 0) {
767 						gothost++;
768 						break;
769 					}
770 				if (gothost)
771 					break;
772 			}
773 			if (hrp == NULL) {
774 				if ((hrp = malloc(sizeof(struct ftphost))) == NULL)
775 					goto nextline;
776 				hrp->hostname = NULL;
777 				insert = 1;
778 			} else {
779 				if (hrp->hostinfo && hrp->hostinfo != res)
780 					freeaddrinfo(hrp->hostinfo);
781 				insert = 0; /* host already in the chain */
782 			}
783 			hrp->hostinfo = res;
784 
785 			/*
786 			 * determine hostname to use.
787 			 * force defined name if there is a valid alias
788 			 * otherwise fallback to primary hostname
789 			 */
790 			/* XXX: getaddrinfo() can't do alias check */
791 			switch(hrp->hostinfo->ai_family) {
792 			case AF_INET:
793 				addr = &((struct sockaddr_in *)hrp->hostinfo->ai_addr)->sin_addr;
794 				addrsize = sizeof(struct in_addr);
795 				break;
796 			case AF_INET6:
797 				addr = &((struct sockaddr_in6 *)hrp->hostinfo->ai_addr)->sin6_addr;
798 				addrsize = sizeof(struct in6_addr);
799 				break;
800 			default:
801 				/* should not reach here */
802 				freeaddrinfo(hrp->hostinfo);
803 				if (insert)
804 					free(hrp); /*not in chain, can free*/
805 				else
806 					hrp->hostinfo = NULL; /*mark as blank*/
807 				goto nextline;
808 				/* NOTREACHED */
809 			}
810 			if ((hp = getipnodebyaddr(addr, addrsize,
811 						  hrp->hostinfo->ai_family,
812 						  &hp_error)) != NULL) {
813 				if (strcmp(vhost, hp->h_name) != 0) {
814 					if (hp->h_aliases == NULL)
815 						vhost = hp->h_name;
816 					else {
817 						i = 0;
818 						while (hp->h_aliases[i] &&
819 						       strcmp(vhost, hp->h_aliases[i]) != 0)
820 							++i;
821 						if (hp->h_aliases[i] == NULL)
822 							vhost = hp->h_name;
823 					}
824 				}
825 			}
826 			if (hrp->hostname &&
827 			    strcmp(hrp->hostname, vhost) != 0) {
828 				free(hrp->hostname);
829 				hrp->hostname = NULL;
830 			}
831 			if (hrp->hostname == NULL &&
832 			    (hrp->hostname = strdup(vhost)) == NULL) {
833 				freeaddrinfo(hrp->hostinfo);
834 				hrp->hostinfo = NULL; /* mark as blank */
835 				if (hp)
836 					freehostent(hp);
837 				goto nextline;
838 			}
839 			hrp->anonuser = anonuser;
840 			hrp->statfile = statfile;
841 			hrp->welcome  = welcome;
842 			hrp->loginmsg = loginmsg;
843 			if (insert) {
844 				hrp->next  = NULL;
845 				lhrp->next = hrp;
846 				lhrp = hrp;
847 			}
848 			if (hp)
849 				freehostent(hp);
850 		      }
851 nextline:
852 			if (mp)
853 				free(mp);
854 		}
855 		(void) fclose(fp);
856 	}
857 }
858 
859 static void
selecthost(union sockunion * su)860 selecthost(union sockunion *su)
861 {
862 	struct ftphost	*hrp;
863 	u_int16_t port;
864 #ifdef INET6
865 	struct in6_addr *mapped_in6 = NULL;
866 #endif
867 	struct addrinfo *hi;
868 
869 #ifdef INET6
870 	/*
871 	 * XXX IPv4 mapped IPv6 addr consideraton,
872 	 * specified in rfc2373.
873 	 */
874 	if (su->su_family == AF_INET6 &&
875 	    IN6_IS_ADDR_V4MAPPED(&su->su_sin6.sin6_addr))
876 		mapped_in6 = &su->su_sin6.sin6_addr;
877 #endif
878 
879 	hrp = thishost = firsthost;	/* default */
880 	port = su->su_port;
881 	su->su_port = 0;
882 	while (hrp != NULL) {
883 	    for (hi = hrp->hostinfo; hi != NULL; hi = hi->ai_next) {
884 		if (memcmp(su, hi->ai_addr, hi->ai_addrlen) == 0) {
885 			thishost = hrp;
886 			goto found;
887 		}
888 #ifdef INET6
889 		/* XXX IPv4 mapped IPv6 addr consideraton */
890 		if (hi->ai_addr->sa_family == AF_INET && mapped_in6 != NULL &&
891 		    (memcmp(&mapped_in6->s6_addr[12],
892 			    &((struct sockaddr_in *)hi->ai_addr)->sin_addr,
893 			    sizeof(struct in_addr)) == 0)) {
894 			thishost = hrp;
895 			goto found;
896 		}
897 #endif
898 	    }
899 	    hrp = hrp->next;
900 	}
901 found:
902 	su->su_port = port;
903 	/* setup static variables as appropriate */
904 	hostname = thishost->hostname;
905 	ftpuser = thishost->anonuser;
906 }
907 #endif
908 
909 /*
910  * Helper function for sgetpwnam().
911  */
912 static char *
sgetsave(char * s)913 sgetsave(char *s)
914 {
915 	char *new = malloc(strlen(s) + 1);
916 
917 	if (new == NULL) {
918 		reply(421, "Ran out of memory.");
919 		dologout(1);
920 		/* NOTREACHED */
921 	}
922 	(void) strcpy(new, s);
923 	return (new);
924 }
925 
926 /*
927  * Save the result of a getpwnam.  Used for USER command, since
928  * the data returned must not be clobbered by any other command
929  * (e.g., globbing).
930  * NB: The data returned by sgetpwnam() will remain valid until
931  * the next call to this function.  Its difference from getpwnam()
932  * is that sgetpwnam() is known to be called from ftpd code only.
933  */
934 static struct passwd *
sgetpwnam(char * name)935 sgetpwnam(char *name)
936 {
937 	static struct passwd save;
938 	struct passwd *p;
939 
940 	if ((p = getpwnam(name)) == NULL)
941 		return (p);
942 	if (save.pw_name) {
943 		free(save.pw_name);
944 		free(save.pw_passwd);
945 		free(save.pw_class);
946 		free(save.pw_gecos);
947 		free(save.pw_dir);
948 		free(save.pw_shell);
949 	}
950 	save = *p;
951 	save.pw_name = sgetsave(p->pw_name);
952 	save.pw_passwd = sgetsave(p->pw_passwd);
953 	save.pw_class = sgetsave(p->pw_class);
954 	save.pw_gecos = sgetsave(p->pw_gecos);
955 	save.pw_dir = sgetsave(p->pw_dir);
956 	save.pw_shell = sgetsave(p->pw_shell);
957 	return (&save);
958 }
959 
960 static int login_attempts;	/* number of failed login attempts */
961 static int askpasswd;		/* had user command, ask for passwd */
962 static char curname[MAXLOGNAME];	/* current USER name */
963 
964 /*
965  * USER command.
966  * Sets global passwd pointer pw if named account exists and is acceptable;
967  * sets askpasswd if a PASS command is expected.  If logged in previously,
968  * need to reset state.  If name is "ftp" or "anonymous", the name is not in
969  * _PATH_FTPUSERS, and ftp account exists, set guest and pw, then just return.
970  * If account doesn't exist, ask for passwd anyway.  Otherwise, check user
971  * requesting login privileges.  Disallow anyone who does not have a standard
972  * shell as returned by getusershell().  Disallow anyone mentioned in the file
973  * _PATH_FTPUSERS to allow people such as root and uucp to be avoided.
974  */
975 void
user(char * name)976 user(char *name)
977 {
978 	int ecode;
979 	char *cp, *shell;
980 
981 	if (logged_in) {
982 		if (guest) {
983 			reply(530, "Can't change user from guest login.");
984 			return;
985 		} else if (dochroot) {
986 			reply(530, "Can't change user from chroot user.");
987 			return;
988 		}
989 		end_login();
990 	}
991 
992 	guest = 0;
993 #ifdef VIRTUAL_HOSTING
994 	pw = sgetpwnam(thishost->anonuser);
995 #else
996 	pw = sgetpwnam("ftp");
997 #endif
998 	if (strcmp(name, "ftp") == 0 || strcmp(name, "anonymous") == 0) {
999 		if (checkuser(_PATH_FTPUSERS, "ftp", 0, NULL, &ecode) ||
1000 		    (ecode != 0 && ecode != ENOENT))
1001 			reply(530, "User %s access denied.", name);
1002 		else if (checkuser(_PATH_FTPUSERS, "anonymous", 0, NULL, &ecode) ||
1003 		    (ecode != 0 && ecode != ENOENT))
1004 			reply(530, "User %s access denied.", name);
1005 		else if (pw != NULL) {
1006 			guest = 1;
1007 			askpasswd = 1;
1008 			reply(331,
1009 			"Guest login ok, send your email address as password.");
1010 		} else
1011 			reply(530, "User %s unknown.", name);
1012 		if (!askpasswd && logging)
1013 			syslog(LOG_NOTICE,
1014 			    "ANONYMOUS FTP LOGIN REFUSED FROM %s", remotehost);
1015 		return;
1016 	}
1017 	if (anon_only != 0) {
1018 		reply(530, "Sorry, only anonymous ftp allowed.");
1019 		return;
1020 	}
1021 
1022 	if ((pw = sgetpwnam(name))) {
1023 		if ((shell = pw->pw_shell) == NULL || *shell == 0)
1024 			shell = _PATH_BSHELL;
1025 		setusershell();
1026 		while ((cp = getusershell()) != NULL)
1027 			if (strcmp(cp, shell) == 0)
1028 				break;
1029 		endusershell();
1030 
1031 		if (cp == NULL ||
1032 		    (checkuser(_PATH_FTPUSERS, name, 1, NULL, &ecode) ||
1033 		    (ecode != 0 && ecode != ENOENT))) {
1034 			reply(530, "User %s access denied.", name);
1035 			if (logging)
1036 				syslog(LOG_NOTICE,
1037 				    "FTP LOGIN REFUSED FROM %s, %s",
1038 				    remotehost, name);
1039 			pw = NULL;
1040 			return;
1041 		}
1042 	}
1043 	if (logging)
1044 		strlcpy(curname, name, sizeof(curname));
1045 
1046 	reply(331, "Password required for %s.", name);
1047 	askpasswd = 1;
1048 	/*
1049 	 * Delay before reading passwd after first failed
1050 	 * attempt to slow down passwd-guessing programs.
1051 	 */
1052 	if (login_attempts)
1053 		sleep(login_attempts);
1054 }
1055 
1056 /*
1057  * Check if a user is in the file "fname",
1058  * return a pointer to a malloc'd string with the rest
1059  * of the matching line in "residue" if not NULL.
1060  */
1061 static int
checkuser(char * fname,char * name,int pwset,char ** residue,int * ecode)1062 checkuser(char *fname, char *name, int pwset, char **residue, int *ecode)
1063 {
1064 	FILE *fd;
1065 	int found = 0;
1066 	size_t len;
1067 	char *line, *mp, *p;
1068 
1069 	if (ecode != NULL)
1070 		*ecode = 0;
1071 	if ((fd = fopen(fname, "r")) != NULL) {
1072 		while (!found && (line = fgetln(fd, &len)) != NULL) {
1073 			/* skip comments */
1074 			if (line[0] == '#')
1075 				continue;
1076 			if (line[len - 1] == '\n') {
1077 				line[len - 1] = '\0';
1078 				mp = NULL;
1079 			} else {
1080 				if ((mp = malloc(len + 1)) == NULL)
1081 					fatalerror("Ran out of memory.");
1082 				memcpy(mp, line, len);
1083 				mp[len] = '\0';
1084 				line = mp;
1085 			}
1086 			/* avoid possible leading and trailing whitespace */
1087 			p = strtok(line, " \t");
1088 			/* skip empty lines */
1089 			if (p == NULL)
1090 				goto nextline;
1091 			/*
1092 			 * if first chr is '@', check group membership
1093 			 */
1094 			if (p[0] == '@') {
1095 				int i = 0;
1096 				struct group *grp;
1097 
1098 				if (p[1] == '\0') /* single @ matches anyone */
1099 					found = 1;
1100 				else {
1101 					if ((grp = getgrnam(p+1)) == NULL)
1102 						goto nextline;
1103 					/*
1104 					 * Check user's default group
1105 					 */
1106 					if (pwset && grp->gr_gid == pw->pw_gid)
1107 						found = 1;
1108 					/*
1109 					 * Check supplementary groups
1110 					 */
1111 					while (!found && grp->gr_mem[i])
1112 						found = strcmp(name,
1113 							grp->gr_mem[i++])
1114 							== 0;
1115 				}
1116 			}
1117 			/*
1118 			 * Otherwise, just check for username match
1119 			 */
1120 			else
1121 				found = strcmp(p, name) == 0;
1122 			/*
1123 			 * Save the rest of line to "residue" if matched
1124 			 */
1125 			if (found && residue) {
1126 				if ((p = strtok(NULL, "")) != NULL)
1127 					p += strspn(p, " \t");
1128 				if (p && *p) {
1129 				 	if ((*residue = strdup(p)) == NULL)
1130 						fatalerror("Ran out of memory.");
1131 				} else
1132 					*residue = NULL;
1133 			}
1134 nextline:
1135 			if (mp)
1136 				free(mp);
1137 		}
1138 		(void) fclose(fd);
1139 	} else if (ecode != NULL)
1140 		*ecode = errno;
1141 	return (found);
1142 }
1143 
1144 /*
1145  * Terminate login as previous user, if any, resetting state;
1146  * used when USER command is given or login fails.
1147  */
1148 static void
end_login(void)1149 end_login(void)
1150 {
1151 #ifdef USE_PAM
1152 	int e;
1153 #endif
1154 
1155 	(void) seteuid(0);
1156 #ifdef	LOGIN_CAP
1157 	setusercontext(NULL, getpwuid(0), 0, LOGIN_SETALL & ~(LOGIN_SETLOGIN |
1158 		       LOGIN_SETUSER | LOGIN_SETGROUP | LOGIN_SETPATH |
1159 		       LOGIN_SETENV));
1160 #endif
1161 	if (logged_in && dowtmp)
1162 		ftpd_logwtmp(wtmpid, NULL, NULL);
1163 	pw = NULL;
1164 #ifdef USE_PAM
1165 	if (pamh) {
1166 		if ((e = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS)
1167 			syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e));
1168 		if ((e = pam_close_session(pamh,0)) != PAM_SUCCESS)
1169 			syslog(LOG_ERR, "pam_close_session: %s", pam_strerror(pamh, e));
1170 		if ((e = pam_end(pamh, e)) != PAM_SUCCESS)
1171 			syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1172 		pamh = NULL;
1173 	}
1174 #endif
1175 	logged_in = 0;
1176 	guest = 0;
1177 	dochroot = 0;
1178 }
1179 
1180 #ifdef USE_PAM
1181 
1182 /*
1183  * the following code is stolen from imap-uw PAM authentication module and
1184  * login.c
1185  */
1186 #define COPY_STRING(s) (s ? strdup(s) : NULL)
1187 
1188 struct cred_t {
1189 	const char *uname;		/* user name */
1190 	const char *pass;		/* password */
1191 };
1192 typedef struct cred_t cred_t;
1193 
1194 static int
auth_conv(int num_msg,const struct pam_message ** msg,struct pam_response ** resp,void * appdata)1195 auth_conv(int num_msg, const struct pam_message **msg,
1196 	  struct pam_response **resp, void *appdata)
1197 {
1198 	int i;
1199 	cred_t *cred = (cred_t *) appdata;
1200 	struct pam_response *reply;
1201 
1202 	reply = calloc(num_msg, sizeof *reply);
1203 	if (reply == NULL)
1204 		return PAM_BUF_ERR;
1205 
1206 	for (i = 0; i < num_msg; i++) {
1207 		switch (msg[i]->msg_style) {
1208 		case PAM_PROMPT_ECHO_ON:	/* assume want user name */
1209 			reply[i].resp_retcode = PAM_SUCCESS;
1210 			reply[i].resp = COPY_STRING(cred->uname);
1211 			/* PAM frees resp. */
1212 			break;
1213 		case PAM_PROMPT_ECHO_OFF:	/* assume want password */
1214 			reply[i].resp_retcode = PAM_SUCCESS;
1215 			reply[i].resp = COPY_STRING(cred->pass);
1216 			/* PAM frees resp. */
1217 			break;
1218 		case PAM_TEXT_INFO:
1219 		case PAM_ERROR_MSG:
1220 			reply[i].resp_retcode = PAM_SUCCESS;
1221 			reply[i].resp = NULL;
1222 			break;
1223 		default:			/* unknown message style */
1224 			free(reply);
1225 			return PAM_CONV_ERR;
1226 		}
1227 	}
1228 
1229 	*resp = reply;
1230 	return PAM_SUCCESS;
1231 }
1232 
1233 /*
1234  * Attempt to authenticate the user using PAM.  Returns 0 if the user is
1235  * authenticated, or 1 if not authenticated.  If some sort of PAM system
1236  * error occurs (e.g., the "/etc/pam.conf" file is missing) then this
1237  * function returns -1.  This can be used as an indication that we should
1238  * fall back to a different authentication mechanism.
1239  */
1240 static int
auth_pam(struct passwd ** ppw,const char * pass)1241 auth_pam(struct passwd **ppw, const char *pass)
1242 {
1243 	const char *tmpl_user;
1244 	const void *item;
1245 	int rval;
1246 	int e;
1247 	cred_t auth_cred = { (*ppw)->pw_name, pass };
1248 	struct pam_conv conv = { &auth_conv, &auth_cred };
1249 
1250 	e = pam_start("ftpd", (*ppw)->pw_name, &conv, &pamh);
1251 	if (e != PAM_SUCCESS) {
1252 		/*
1253 		 * In OpenPAM, it's OK to pass NULL to pam_strerror()
1254 		 * if context creation has failed in the first place.
1255 		 */
1256 		syslog(LOG_ERR, "pam_start: %s", pam_strerror(NULL, e));
1257 		return -1;
1258 	}
1259 
1260 	e = pam_set_item(pamh, PAM_RHOST, remotehost);
1261 	if (e != PAM_SUCCESS) {
1262 		syslog(LOG_ERR, "pam_set_item(PAM_RHOST): %s",
1263 			pam_strerror(pamh, e));
1264 		if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
1265 			syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1266 		}
1267 		pamh = NULL;
1268 		return -1;
1269 	}
1270 
1271 	e = pam_authenticate(pamh, 0);
1272 	switch (e) {
1273 	case PAM_SUCCESS:
1274 		/*
1275 		 * With PAM we support the concept of a "template"
1276 		 * user.  The user enters a login name which is
1277 		 * authenticated by PAM, usually via a remote service
1278 		 * such as RADIUS or TACACS+.  If authentication
1279 		 * succeeds, a different but related "template" name
1280 		 * is used for setting the credentials, shell, and
1281 		 * home directory.  The name the user enters need only
1282 		 * exist on the remote authentication server, but the
1283 		 * template name must be present in the local password
1284 		 * database.
1285 		 *
1286 		 * This is supported by two various mechanisms in the
1287 		 * individual modules.  However, from the application's
1288 		 * point of view, the template user is always passed
1289 		 * back as a changed value of the PAM_USER item.
1290 		 */
1291 		if ((e = pam_get_item(pamh, PAM_USER, &item)) ==
1292 		    PAM_SUCCESS) {
1293 			tmpl_user = (const char *) item;
1294 			if (strcmp((*ppw)->pw_name, tmpl_user) != 0)
1295 				*ppw = getpwnam(tmpl_user);
1296 		} else
1297 			syslog(LOG_ERR, "Couldn't get PAM_USER: %s",
1298 			    pam_strerror(pamh, e));
1299 		rval = 0;
1300 		break;
1301 
1302 	case PAM_AUTH_ERR:
1303 	case PAM_USER_UNKNOWN:
1304 	case PAM_MAXTRIES:
1305 		rval = 1;
1306 		break;
1307 
1308 	default:
1309 		syslog(LOG_ERR, "pam_authenticate: %s", pam_strerror(pamh, e));
1310 		rval = -1;
1311 		break;
1312 	}
1313 
1314 	if (rval == 0) {
1315 		e = pam_acct_mgmt(pamh, 0);
1316 		if (e != PAM_SUCCESS) {
1317 			syslog(LOG_ERR, "pam_acct_mgmt: %s",
1318 						pam_strerror(pamh, e));
1319 			rval = 1;
1320 		}
1321 	}
1322 
1323 	if (rval != 0) {
1324 		if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
1325 			syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1326 		}
1327 		pamh = NULL;
1328 	}
1329 	return rval;
1330 }
1331 
1332 #endif /* USE_PAM */
1333 
1334 void
pass(char * passwd)1335 pass(char *passwd)
1336 {
1337 	int rval, ecode;
1338 	FILE *fd;
1339 #ifdef	LOGIN_CAP
1340 	login_cap_t *lc = NULL;
1341 #endif
1342 #ifdef USE_PAM
1343 	int e;
1344 #endif
1345 	char *residue = NULL;
1346 	char *xpasswd;
1347 
1348 	if (logged_in || askpasswd == 0) {
1349 		reply(503, "Login with USER first.");
1350 		return;
1351 	}
1352 	askpasswd = 0;
1353 	if (!guest) {		/* "ftp" is only account allowed no password */
1354 		if (pw == NULL) {
1355 			rval = 1;	/* failure below */
1356 			goto skip;
1357 		}
1358 #ifdef USE_PAM
1359 		rval = auth_pam(&pw, passwd);
1360 		if (rval >= 0) {
1361 			goto skip;
1362 		}
1363 #endif
1364 		xpasswd = crypt(passwd, pw->pw_passwd);
1365 		if (passwd[0] == '\0' && pw->pw_passwd[0] != '\0')
1366 			xpasswd = ":";
1367 		rval = strcmp(pw->pw_passwd, xpasswd);
1368 		if (pw->pw_expire && time(NULL) >= pw->pw_expire)
1369 			rval = 1;	/* failure */
1370 skip:
1371 		/*
1372 		 * If rval == 1, the user failed the authentication check
1373 		 * above.  If rval == 0, either PAM or local authentication
1374 		 * succeeded.
1375 		 */
1376 		if (rval) {
1377 			reply(530, "Login incorrect.");
1378 			BLACKLIST_NOTIFY(BLACKLIST_AUTH_FAIL, STDIN_FILENO, "Login incorrect");
1379 			if (logging) {
1380 				syslog(LOG_NOTICE,
1381 				    "FTP LOGIN FAILED FROM %s",
1382 				    remotehost);
1383 				syslog(LOG_AUTHPRIV | LOG_NOTICE,
1384 				    "FTP LOGIN FAILED FROM %s, %s",
1385 				    remotehost, curname);
1386 			}
1387 			pw = NULL;
1388 			if (login_attempts++ >= 5) {
1389 				syslog(LOG_NOTICE,
1390 				    "repeated login failures from %s",
1391 				    remotehost);
1392 				exit(0);
1393 			}
1394 			return;
1395 		} else {
1396 			BLACKLIST_NOTIFY(BLACKLIST_AUTH_OK, STDIN_FILENO, "Login successful");
1397 		}
1398 	}
1399 	login_attempts = 0;		/* this time successful */
1400 	if (setegid(pw->pw_gid) < 0) {
1401 		reply(550, "Can't set gid.");
1402 		return;
1403 	}
1404 	/* May be overridden by login.conf */
1405 	(void) umask(defumask);
1406 #ifdef	LOGIN_CAP
1407 	if ((lc = login_getpwclass(pw)) != NULL) {
1408 		char	remote_ip[NI_MAXHOST];
1409 
1410 		if (getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
1411 			remote_ip, sizeof(remote_ip) - 1, NULL, 0,
1412 			NI_NUMERICHOST))
1413 				*remote_ip = 0;
1414 		remote_ip[sizeof(remote_ip) - 1] = 0;
1415 		if (!auth_hostok(lc, remotehost, remote_ip)) {
1416 			syslog(LOG_INFO|LOG_AUTH,
1417 			    "FTP LOGIN FAILED (HOST) as %s: permission denied.",
1418 			    pw->pw_name);
1419 			reply(530, "Permission denied.");
1420 			pw = NULL;
1421 			return;
1422 		}
1423 		if (!auth_timeok(lc, time(NULL))) {
1424 			reply(530, "Login not available right now.");
1425 			pw = NULL;
1426 			return;
1427 		}
1428 	}
1429 	setusercontext(lc, pw, 0, LOGIN_SETALL &
1430 		       ~(LOGIN_SETRESOURCES | LOGIN_SETUSER | LOGIN_SETPATH | LOGIN_SETENV));
1431 #else
1432 	setlogin(pw->pw_name);
1433 	(void) initgroups(pw->pw_name, pw->pw_gid);
1434 #endif
1435 
1436 #ifdef USE_PAM
1437 	if (pamh) {
1438 		if ((e = pam_open_session(pamh, 0)) != PAM_SUCCESS) {
1439 			syslog(LOG_ERR, "pam_open_session: %s", pam_strerror(pamh, e));
1440 		} else if ((e = pam_setcred(pamh, PAM_ESTABLISH_CRED)) != PAM_SUCCESS) {
1441 			syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e));
1442 		}
1443 	}
1444 #endif
1445 
1446 	dochroot =
1447 		checkuser(_PATH_FTPCHROOT, pw->pw_name, 1, &residue, &ecode)
1448 #ifdef	LOGIN_CAP	/* Allow login.conf configuration as well */
1449 		|| login_getcapbool(lc, "ftp-chroot", 0)
1450 #endif
1451 	;
1452 	/*
1453 	 * It is possible that checkuser() failed to open the chroot file.
1454 	 * If this is the case, report that logins are un-available, since we
1455 	 * have no way of checking whether or not the user should be chrooted.
1456 	 * We ignore ENOENT since it is not required that this file be present.
1457 	 */
1458 	if (ecode != 0 && ecode != ENOENT) {
1459 		reply(530, "Login not available right now.");
1460 		return;
1461 	}
1462 	chrootdir = NULL;
1463 
1464 	/* Disable wtmp logging when chrooting. */
1465 	if (dochroot || guest)
1466 		dowtmp = 0;
1467 	if (dowtmp)
1468 		ftpd_logwtmp(wtmpid, pw->pw_name,
1469 		    (struct sockaddr *)&his_addr);
1470 	logged_in = 1;
1471 
1472 #ifdef	LOGIN_CAP
1473 	setusercontext(lc, pw, 0, LOGIN_SETRESOURCES);
1474 #endif
1475 
1476 	if (guest && stats && statfd < 0) {
1477 #ifdef VIRTUAL_HOSTING
1478 		statfd = open(thishost->statfile, O_WRONLY|O_APPEND);
1479 #else
1480 		statfd = open(_PATH_FTPDSTATFILE, O_WRONLY|O_APPEND);
1481 #endif
1482 		if (statfd < 0)
1483 			stats = 0;
1484 	}
1485 
1486 	/*
1487 	 * For a chrooted local user,
1488 	 * a) see whether ftpchroot(5) specifies a chroot directory,
1489 	 * b) extract the directory pathname from the line,
1490 	 * c) expand it to the absolute pathname if necessary.
1491 	 */
1492 	if (dochroot && residue &&
1493 	    (chrootdir = strtok(residue, " \t")) != NULL) {
1494 		if (chrootdir[0] != '/')
1495 			asprintf(&chrootdir, "%s/%s", pw->pw_dir, chrootdir);
1496 		else
1497 			chrootdir = strdup(chrootdir); /* make it permanent */
1498 		if (chrootdir == NULL)
1499 			fatalerror("Ran out of memory.");
1500 	}
1501 	if (guest || dochroot) {
1502 		/*
1503 		 * If no chroot directory set yet, use the login directory.
1504 		 * Copy it so it can be modified while pw->pw_dir stays intact.
1505 		 */
1506 		if (chrootdir == NULL &&
1507 		    (chrootdir = strdup(pw->pw_dir)) == NULL)
1508 			fatalerror("Ran out of memory.");
1509 		/*
1510 		 * Check for the "/chroot/./home" syntax,
1511 		 * separate the chroot and home directory pathnames.
1512 		 */
1513 		if ((homedir = strstr(chrootdir, "/./")) != NULL) {
1514 			*(homedir++) = '\0';	/* wipe '/' */
1515 			homedir++;		/* skip '.' */
1516 		} else {
1517 			/*
1518 			 * We MUST do a chdir() after the chroot. Otherwise
1519 			 * the old current directory will be accessible as "."
1520 			 * outside the new root!
1521 			 */
1522 			homedir = "/";
1523 		}
1524 		/*
1525 		 * Finally, do chroot()
1526 		 */
1527 		if (chroot(chrootdir) < 0) {
1528 			reply(550, "Can't change root.");
1529 			goto bad;
1530 		}
1531 		__FreeBSD_libc_enter_restricted_mode();
1532 	} else	/* real user w/o chroot */
1533 		homedir = pw->pw_dir;
1534 	/*
1535 	 * Set euid *before* doing chdir() so
1536 	 * a) the user won't be carried to a directory that he couldn't reach
1537 	 *    on his own due to no permission to upper path components,
1538 	 * b) NFS mounted homedirs w/restrictive permissions will be accessible
1539 	 *    (uid 0 has no root power over NFS if not mapped explicitly.)
1540 	 */
1541 	if (seteuid(pw->pw_uid) < 0) {
1542 		if (guest || dochroot) {
1543 			fatalerror("Can't set uid.");
1544 		} else {
1545 			reply(550, "Can't set uid.");
1546 			goto bad;
1547 		}
1548 	}
1549 	/*
1550 	 * Do not allow the session to live if we're chroot()'ed and chdir()
1551 	 * fails. Otherwise the chroot jail can be escaped.
1552 	 */
1553 	if (chdir(homedir) < 0) {
1554 		if (guest || dochroot) {
1555 			fatalerror("Can't change to base directory.");
1556 		} else {
1557 			if (chdir("/") < 0) {
1558 				reply(550, "Root is inaccessible.");
1559 				goto bad;
1560 			}
1561 			lreply(230, "No directory! Logging in with home=/.");
1562 		}
1563 	}
1564 
1565 	/*
1566 	 * Display a login message, if it exists.
1567 	 * N.B. reply(230,) must follow the message.
1568 	 */
1569 #ifdef VIRTUAL_HOSTING
1570 	fd = fopen(thishost->loginmsg, "r");
1571 #else
1572 	fd = fopen(_PATH_FTPLOGINMESG, "r");
1573 #endif
1574 	if (fd != NULL) {
1575 		char *cp, line[LINE_MAX];
1576 
1577 		while (fgets(line, sizeof(line), fd) != NULL) {
1578 			if ((cp = strchr(line, '\n')) != NULL)
1579 				*cp = '\0';
1580 			lreply(230, "%s", line);
1581 		}
1582 		(void) fflush(stdout);
1583 		(void) fclose(fd);
1584 	}
1585 	if (guest) {
1586 		if (ident != NULL)
1587 			free(ident);
1588 		ident = strdup(passwd);
1589 		if (ident == NULL)
1590 			fatalerror("Ran out of memory.");
1591 
1592 		reply(230, "Guest login ok, access restrictions apply.");
1593 #ifdef SETPROCTITLE
1594 #ifdef VIRTUAL_HOSTING
1595 		if (thishost != firsthost)
1596 			snprintf(proctitle, sizeof(proctitle),
1597 				 "%s: anonymous(%s)/%s", remotehost, hostname,
1598 				 passwd);
1599 		else
1600 #endif
1601 			snprintf(proctitle, sizeof(proctitle),
1602 				 "%s: anonymous/%s", remotehost, passwd);
1603 		setproctitle("%s", proctitle);
1604 #endif /* SETPROCTITLE */
1605 		if (logging)
1606 			syslog(LOG_INFO, "ANONYMOUS FTP LOGIN FROM %s, %s",
1607 			    remotehost, passwd);
1608 	} else {
1609 		if (dochroot)
1610 			reply(230, "User %s logged in, "
1611 				   "access restrictions apply.", pw->pw_name);
1612 		else
1613 			reply(230, "User %s logged in.", pw->pw_name);
1614 
1615 #ifdef SETPROCTITLE
1616 		snprintf(proctitle, sizeof(proctitle),
1617 			 "%s: user/%s", remotehost, pw->pw_name);
1618 		setproctitle("%s", proctitle);
1619 #endif /* SETPROCTITLE */
1620 		if (logging)
1621 			syslog(LOG_INFO, "FTP LOGIN FROM %s as %s",
1622 			    remotehost, pw->pw_name);
1623 	}
1624 	if (logging && (guest || dochroot))
1625 		syslog(LOG_INFO, "session root changed to %s", chrootdir);
1626 #ifdef	LOGIN_CAP
1627 	login_close(lc);
1628 #endif
1629 	if (residue)
1630 		free(residue);
1631 	return;
1632 bad:
1633 	/* Forget all about it... */
1634 #ifdef	LOGIN_CAP
1635 	login_close(lc);
1636 #endif
1637 	if (residue)
1638 		free(residue);
1639 	end_login();
1640 }
1641 
1642 void
retrieve(char * cmd,char * name)1643 retrieve(char *cmd, char *name)
1644 {
1645 	FILE *fin, *dout;
1646 	struct stat st;
1647 	int (*closefunc)(FILE *);
1648 	time_t start;
1649 	char line[BUFSIZ];
1650 
1651 	if (cmd == 0) {
1652 		fin = fopen(name, "r"), closefunc = fclose;
1653 		st.st_size = 0;
1654 	} else {
1655 		(void) snprintf(line, sizeof(line), cmd, name);
1656 		name = line;
1657 		fin = ftpd_popen(line, "r"), closefunc = ftpd_pclose;
1658 		st.st_size = -1;
1659 		st.st_blksize = BUFSIZ;
1660 	}
1661 	if (fin == NULL) {
1662 		if (errno != 0) {
1663 			perror_reply(550, name);
1664 			if (cmd == 0) {
1665 				LOGCMD("get", name);
1666 			}
1667 		}
1668 		return;
1669 	}
1670 	byte_count = -1;
1671 	if (cmd == 0) {
1672 		if (fstat(fileno(fin), &st) < 0) {
1673 			perror_reply(550, name);
1674 			goto done;
1675 		}
1676 		if (!S_ISREG(st.st_mode)) {
1677 			/*
1678 			 * Never sending a raw directory is a workaround
1679 			 * for buggy clients that will attempt to RETR
1680 			 * a directory before listing it, e.g., Mozilla.
1681 			 * Preventing a guest from getting irregular files
1682 			 * is a simple security measure.
1683 			 */
1684 			if (S_ISDIR(st.st_mode) || guest) {
1685 				reply(550, "%s: not a plain file.", name);
1686 				goto done;
1687 			}
1688 			st.st_size = -1;
1689 			/* st.st_blksize is set for all descriptor types */
1690 		}
1691 	}
1692 	if (restart_point) {
1693 		if (type == TYPE_A) {
1694 			off_t i, n;
1695 			int c;
1696 
1697 			n = restart_point;
1698 			i = 0;
1699 			while (i++ < n) {
1700 				if ((c=getc(fin)) == EOF) {
1701 					perror_reply(550, name);
1702 					goto done;
1703 				}
1704 				if (c == '\n')
1705 					i++;
1706 			}
1707 		} else if (lseek(fileno(fin), restart_point, L_SET) < 0) {
1708 			perror_reply(550, name);
1709 			goto done;
1710 		}
1711 	}
1712 	dout = dataconn(name, st.st_size, "w");
1713 	if (dout == NULL)
1714 		goto done;
1715 	time(&start);
1716 	send_data(fin, dout, st.st_blksize, st.st_size,
1717 		  restart_point == 0 && cmd == 0 && S_ISREG(st.st_mode));
1718 	if (cmd == 0 && guest && stats && byte_count > 0)
1719 		logxfer(name, byte_count, start);
1720 	(void) fclose(dout);
1721 	data = -1;
1722 	pdata = -1;
1723 done:
1724 	if (cmd == 0)
1725 		LOGBYTES("get", name, byte_count);
1726 	(*closefunc)(fin);
1727 }
1728 
1729 void
store(char * name,char * mode,int unique)1730 store(char *name, char *mode, int unique)
1731 {
1732 	int fd;
1733 	FILE *fout, *din;
1734 	int (*closefunc)(FILE *);
1735 
1736 	if (*mode == 'a') {		/* APPE */
1737 		if (unique) {
1738 			/* Programming error */
1739 			syslog(LOG_ERR, "Internal: unique flag to APPE");
1740 			unique = 0;
1741 		}
1742 		if (guest && noguestmod) {
1743 			reply(550, "Appending to existing file denied.");
1744 			goto err;
1745 		}
1746 		restart_point = 0;	/* not affected by preceding REST */
1747 	}
1748 	if (unique)			/* STOU overrides REST */
1749 		restart_point = 0;
1750 	if (guest && noguestmod) {
1751 		if (restart_point) {	/* guest STOR w/REST */
1752 			reply(550, "Modifying existing file denied.");
1753 			goto err;
1754 		} else			/* treat guest STOR as STOU */
1755 			unique = 1;
1756 	}
1757 
1758 	if (restart_point)
1759 		mode = "r+";	/* so ASCII manual seek can work */
1760 	if (unique) {
1761 		if ((fd = guniquefd(name, &name)) < 0)
1762 			goto err;
1763 		fout = fdopen(fd, mode);
1764 	} else
1765 		fout = fopen(name, mode);
1766 	closefunc = fclose;
1767 	if (fout == NULL) {
1768 		perror_reply(553, name);
1769 		goto err;
1770 	}
1771 	byte_count = -1;
1772 	if (restart_point) {
1773 		if (type == TYPE_A) {
1774 			off_t i, n;
1775 			int c;
1776 
1777 			n = restart_point;
1778 			i = 0;
1779 			while (i++ < n) {
1780 				if ((c=getc(fout)) == EOF) {
1781 					perror_reply(550, name);
1782 					goto done;
1783 				}
1784 				if (c == '\n')
1785 					i++;
1786 			}
1787 			/*
1788 			 * We must do this seek to "current" position
1789 			 * because we are changing from reading to
1790 			 * writing.
1791 			 */
1792 			if (fseeko(fout, 0, SEEK_CUR) < 0) {
1793 				perror_reply(550, name);
1794 				goto done;
1795 			}
1796 		} else if (lseek(fileno(fout), restart_point, L_SET) < 0) {
1797 			perror_reply(550, name);
1798 			goto done;
1799 		}
1800 	}
1801 	din = dataconn(name, -1, "r");
1802 	if (din == NULL)
1803 		goto done;
1804 	if (receive_data(din, fout) == 0) {
1805 		if (unique)
1806 			reply(226, "Transfer complete (unique file name:%s).",
1807 			    name);
1808 		else
1809 			reply(226, "Transfer complete.");
1810 	}
1811 	(void) fclose(din);
1812 	data = -1;
1813 	pdata = -1;
1814 done:
1815 	LOGBYTES(*mode == 'a' ? "append" : "put", name, byte_count);
1816 	(*closefunc)(fout);
1817 	return;
1818 err:
1819 	LOGCMD(*mode == 'a' ? "append" : "put" , name);
1820 	return;
1821 }
1822 
1823 static FILE *
getdatasock(char * mode)1824 getdatasock(char *mode)
1825 {
1826 	int on = 1, s, t, tries;
1827 
1828 	if (data >= 0)
1829 		return (fdopen(data, mode));
1830 
1831 	s = socket(data_dest.su_family, SOCK_STREAM, 0);
1832 	if (s < 0)
1833 		goto bad;
1834 	if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
1835 		syslog(LOG_WARNING, "data setsockopt (SO_REUSEADDR): %m");
1836 	/* anchor socket to avoid multi-homing problems */
1837 	data_source = ctrl_addr;
1838 	data_source.su_port = htons(dataport);
1839 	(void) seteuid(0);
1840 	for (tries = 1; ; tries++) {
1841 		/*
1842 		 * We should loop here since it's possible that
1843 		 * another ftpd instance has passed this point and is
1844 		 * trying to open a data connection in active mode now.
1845 		 * Until the other connection is opened, we'll be getting
1846 		 * EADDRINUSE because no SOCK_STREAM sockets in the system
1847 		 * can share both local and remote addresses, localIP:20
1848 		 * and *:* in this case.
1849 		 */
1850 		if (bind(s, (struct sockaddr *)&data_source,
1851 		    data_source.su_len) >= 0)
1852 			break;
1853 		if (errno != EADDRINUSE || tries > 10)
1854 			goto bad;
1855 		sleep(tries);
1856 	}
1857 	(void) seteuid(pw->pw_uid);
1858 #ifdef IP_TOS
1859 	if (data_source.su_family == AF_INET)
1860       {
1861 	on = IPTOS_THROUGHPUT;
1862 	if (setsockopt(s, IPPROTO_IP, IP_TOS, &on, sizeof(int)) < 0)
1863 		syslog(LOG_WARNING, "data setsockopt (IP_TOS): %m");
1864       }
1865 #endif
1866 #ifdef TCP_NOPUSH
1867 	/*
1868 	 * Turn off push flag to keep sender TCP from sending short packets
1869 	 * at the boundaries of each write().
1870 	 */
1871 	on = 1;
1872 	if (setsockopt(s, IPPROTO_TCP, TCP_NOPUSH, &on, sizeof on) < 0)
1873 		syslog(LOG_WARNING, "data setsockopt (TCP_NOPUSH): %m");
1874 #endif
1875 	return (fdopen(s, mode));
1876 bad:
1877 	/* Return the real value of errno (close may change it) */
1878 	t = errno;
1879 	(void) seteuid(pw->pw_uid);
1880 	(void) close(s);
1881 	errno = t;
1882 	return (NULL);
1883 }
1884 
1885 static FILE *
dataconn(char * name,off_t size,char * mode)1886 dataconn(char *name, off_t size, char *mode)
1887 {
1888 	char sizebuf[32];
1889 	FILE *file;
1890 	int retry = 0, tos, conerrno;
1891 
1892 	file_size = size;
1893 	byte_count = 0;
1894 	if (size != -1)
1895 		(void) snprintf(sizebuf, sizeof(sizebuf),
1896 				" (%jd bytes)", (intmax_t)size);
1897 	else
1898 		*sizebuf = '\0';
1899 	if (pdata >= 0) {
1900 		union sockunion from;
1901 		socklen_t fromlen = ctrl_addr.su_len;
1902 		int flags, s;
1903 		struct timeval timeout;
1904 		fd_set set;
1905 
1906 		FD_ZERO(&set);
1907 		FD_SET(pdata, &set);
1908 
1909 		timeout.tv_usec = 0;
1910 		timeout.tv_sec = 120;
1911 
1912 		/*
1913 		 * Granted a socket is in the blocking I/O mode,
1914 		 * accept() will block after a successful select()
1915 		 * if the selected connection dies in between.
1916 		 * Therefore set the non-blocking I/O flag here.
1917 		 */
1918 		if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1919 		    fcntl(pdata, F_SETFL, flags | O_NONBLOCK) == -1)
1920 			goto pdata_err;
1921 		if (select(pdata+1, &set, NULL, NULL, &timeout) <= 0 ||
1922 		    (s = accept(pdata, (struct sockaddr *) &from, &fromlen)) < 0)
1923 			goto pdata_err;
1924 		(void) close(pdata);
1925 		pdata = s;
1926 		/*
1927 		 * Unset the inherited non-blocking I/O flag
1928 		 * on the child socket so stdio can work on it.
1929 		 */
1930 		if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1931 		    fcntl(pdata, F_SETFL, flags & ~O_NONBLOCK) == -1)
1932 			goto pdata_err;
1933 #ifdef IP_TOS
1934 		if (from.su_family == AF_INET)
1935 	      {
1936 		tos = IPTOS_THROUGHPUT;
1937 		if (setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
1938 			syslog(LOG_WARNING, "pdata setsockopt (IP_TOS): %m");
1939 	      }
1940 #endif
1941 		reply(150, "Opening %s mode data connection for '%s'%s.",
1942 		     type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1943 		return (fdopen(pdata, mode));
1944 pdata_err:
1945 		reply(425, "Can't open data connection.");
1946 		(void) close(pdata);
1947 		pdata = -1;
1948 		return (NULL);
1949 	}
1950 	if (data >= 0) {
1951 		reply(125, "Using existing data connection for '%s'%s.",
1952 		    name, sizebuf);
1953 		usedefault = 1;
1954 		return (fdopen(data, mode));
1955 	}
1956 	if (usedefault)
1957 		data_dest = his_addr;
1958 	usedefault = 1;
1959 	do {
1960 		file = getdatasock(mode);
1961 		if (file == NULL) {
1962 			char hostbuf[NI_MAXHOST], portbuf[NI_MAXSERV];
1963 
1964 			if (getnameinfo((struct sockaddr *)&data_source,
1965 				data_source.su_len,
1966 				hostbuf, sizeof(hostbuf) - 1,
1967 				portbuf, sizeof(portbuf) - 1,
1968 				NI_NUMERICHOST|NI_NUMERICSERV))
1969 					*hostbuf = *portbuf = 0;
1970 			hostbuf[sizeof(hostbuf) - 1] = 0;
1971 			portbuf[sizeof(portbuf) - 1] = 0;
1972 			reply(425, "Can't create data socket (%s,%s): %s.",
1973 				hostbuf, portbuf, strerror(errno));
1974 			return (NULL);
1975 		}
1976 		data = fileno(file);
1977 		conerrno = 0;
1978 		if (connect(data, (struct sockaddr *)&data_dest,
1979 		    data_dest.su_len) == 0)
1980 			break;
1981 		conerrno = errno;
1982 		(void) fclose(file);
1983 		data = -1;
1984 		if (conerrno == EADDRINUSE) {
1985 			sleep(swaitint);
1986 			retry += swaitint;
1987 		} else {
1988 			break;
1989 		}
1990 	} while (retry <= swaitmax);
1991 	if (conerrno != 0) {
1992 		reply(425, "Can't build data connection: %s.",
1993 			   strerror(conerrno));
1994 		return (NULL);
1995 	}
1996 	reply(150, "Opening %s mode data connection for '%s'%s.",
1997 	     type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1998 	return (file);
1999 }
2000 
2001 /*
2002  * A helper macro to avoid code duplication
2003  * in send_data() and receive_data().
2004  *
2005  * XXX We have to block SIGURG during putc() because BSD stdio
2006  * is unable to restart interrupted write operations and hence
2007  * the entire buffer contents will be lost as soon as a write()
2008  * call indicates EINTR to stdio.
2009  */
2010 #define FTPD_PUTC(ch, file, label)					\
2011 	do {								\
2012 		int ret;						\
2013 									\
2014 		do {							\
2015 			START_UNSAFE;					\
2016 			ret = putc((ch), (file));			\
2017 			END_UNSAFE;					\
2018 			CHECKOOB(return (-1))				\
2019 			else if (ferror(file))				\
2020 				goto label;				\
2021 			clearerr(file);					\
2022 		} while (ret == EOF);					\
2023 	} while (0)
2024 
2025 /*
2026  * Transfer the contents of "instr" to "outstr" peer using the appropriate
2027  * encapsulation of the data subject to Mode, Structure, and Type.
2028  *
2029  * NB: Form isn't handled.
2030  */
2031 static int
send_data(FILE * instr,FILE * outstr,size_t blksize,off_t filesize,int isreg)2032 send_data(FILE *instr, FILE *outstr, size_t blksize, off_t filesize, int isreg)
2033 {
2034 	int c, cp, filefd, netfd;
2035 	char *buf;
2036 
2037 	STARTXFER;
2038 
2039 	switch (type) {
2040 
2041 	case TYPE_A:
2042 		cp = EOF;
2043 		for (;;) {
2044 			c = getc(instr);
2045 			CHECKOOB(return (-1))
2046 			else if (c == EOF && ferror(instr))
2047 				goto file_err;
2048 			if (c == EOF) {
2049 				if (ferror(instr)) {	/* resume after OOB */
2050 					clearerr(instr);
2051 					continue;
2052 				}
2053 				if (feof(instr))	/* EOF */
2054 					break;
2055 				syslog(LOG_ERR, "Internal: impossible condition"
2056 						" on file after getc()");
2057 				goto file_err;
2058 			}
2059 			if (c == '\n' && cp != '\r') {
2060 				FTPD_PUTC('\r', outstr, data_err);
2061 				byte_count++;
2062 			}
2063 			FTPD_PUTC(c, outstr, data_err);
2064 			byte_count++;
2065 			cp = c;
2066 		}
2067 #ifdef notyet	/* BSD stdio isn't ready for that */
2068 		while (fflush(outstr) == EOF) {
2069 			CHECKOOB(return (-1))
2070 			else
2071 				goto data_err;
2072 			clearerr(outstr);
2073 		}
2074 		ENDXFER;
2075 #else
2076 		ENDXFER;
2077 		if (fflush(outstr) == EOF)
2078 			goto data_err;
2079 #endif
2080 		reply(226, "Transfer complete.");
2081 		return (0);
2082 
2083 	case TYPE_I:
2084 	case TYPE_L:
2085 		/*
2086 		 * isreg is only set if we are not doing restart and we
2087 		 * are sending a regular file
2088 		 */
2089 		netfd = fileno(outstr);
2090 		filefd = fileno(instr);
2091 
2092 		if (isreg) {
2093 			char *msg = "Transfer complete.";
2094 			off_t cnt, offset;
2095 			int err;
2096 
2097 			cnt = offset = 0;
2098 
2099 			while (filesize > 0) {
2100 				err = sendfile(filefd, netfd, offset, 0,
2101 					       NULL, &cnt, 0);
2102 				/*
2103 				 * Calculate byte_count before OOB processing.
2104 				 * It can be used in myoob() later.
2105 				 */
2106 				byte_count += cnt;
2107 				offset += cnt;
2108 				filesize -= cnt;
2109 				CHECKOOB(return (-1))
2110 				else if (err == -1) {
2111 					if (errno != EINTR &&
2112 					    cnt == 0 && offset == 0)
2113 						goto oldway;
2114 					goto data_err;
2115 				}
2116 				if (err == -1)	/* resume after OOB */
2117 					continue;
2118 				/*
2119 				 * We hit the EOF prematurely.
2120 				 * Perhaps the file was externally truncated.
2121 				 */
2122 				if (cnt == 0) {
2123 					msg = "Transfer finished due to "
2124 					      "premature end of file.";
2125 					break;
2126 				}
2127 			}
2128 			ENDXFER;
2129 			reply(226, "%s", msg);
2130 			return (0);
2131 		}
2132 
2133 oldway:
2134 		if ((buf = malloc(blksize)) == NULL) {
2135 			ENDXFER;
2136 			reply(451, "Ran out of memory.");
2137 			return (-1);
2138 		}
2139 
2140 		for (;;) {
2141 			int cnt, len;
2142 			char *bp;
2143 
2144 			cnt = read(filefd, buf, blksize);
2145 			CHECKOOB(free(buf); return (-1))
2146 			else if (cnt < 0) {
2147 				free(buf);
2148 				goto file_err;
2149 			}
2150 			if (cnt < 0)	/* resume after OOB */
2151 				continue;
2152 			if (cnt == 0)	/* EOF */
2153 				break;
2154 			for (len = cnt, bp = buf; len > 0;) {
2155 				cnt = write(netfd, bp, len);
2156 				CHECKOOB(free(buf); return (-1))
2157 				else if (cnt < 0) {
2158 					free(buf);
2159 					goto data_err;
2160 				}
2161 				if (cnt <= 0)
2162 					continue;
2163 				len -= cnt;
2164 				bp += cnt;
2165 				byte_count += cnt;
2166 			}
2167 		}
2168 		ENDXFER;
2169 		free(buf);
2170 		reply(226, "Transfer complete.");
2171 		return (0);
2172 	default:
2173 		ENDXFER;
2174 		reply(550, "Unimplemented TYPE %d in send_data.", type);
2175 		return (-1);
2176 	}
2177 
2178 data_err:
2179 	ENDXFER;
2180 	perror_reply(426, "Data connection");
2181 	return (-1);
2182 
2183 file_err:
2184 	ENDXFER;
2185 	perror_reply(551, "Error on input file");
2186 	return (-1);
2187 }
2188 
2189 /*
2190  * Transfer data from peer to "outstr" using the appropriate encapulation of
2191  * the data subject to Mode, Structure, and Type.
2192  *
2193  * N.B.: Form isn't handled.
2194  */
2195 static int
receive_data(FILE * instr,FILE * outstr)2196 receive_data(FILE *instr, FILE *outstr)
2197 {
2198 	int c, cp;
2199 	int bare_lfs = 0;
2200 
2201 	STARTXFER;
2202 
2203 	switch (type) {
2204 
2205 	case TYPE_I:
2206 	case TYPE_L:
2207 		for (;;) {
2208 			int cnt, len;
2209 			char *bp;
2210 			char buf[BUFSIZ];
2211 
2212 			cnt = read(fileno(instr), buf, sizeof(buf));
2213 			CHECKOOB(return (-1))
2214 			else if (cnt < 0)
2215 				goto data_err;
2216 			if (cnt < 0)	/* resume after OOB */
2217 				continue;
2218 			if (cnt == 0)	/* EOF */
2219 				break;
2220 			for (len = cnt, bp = buf; len > 0;) {
2221 				cnt = write(fileno(outstr), bp, len);
2222 				CHECKOOB(return (-1))
2223 				else if (cnt < 0)
2224 					goto file_err;
2225 				if (cnt <= 0)
2226 					continue;
2227 				len -= cnt;
2228 				bp += cnt;
2229 				byte_count += cnt;
2230 			}
2231 		}
2232 		ENDXFER;
2233 		return (0);
2234 
2235 	case TYPE_E:
2236 		ENDXFER;
2237 		reply(553, "TYPE E not implemented.");
2238 		return (-1);
2239 
2240 	case TYPE_A:
2241 		cp = EOF;
2242 		for (;;) {
2243 			c = getc(instr);
2244 			CHECKOOB(return (-1))
2245 			else if (c == EOF && ferror(instr))
2246 				goto data_err;
2247 			if (c == EOF && ferror(instr)) { /* resume after OOB */
2248 				clearerr(instr);
2249 				continue;
2250 			}
2251 
2252 			if (cp == '\r') {
2253 				if (c != '\n')
2254 					FTPD_PUTC('\r', outstr, file_err);
2255 			} else
2256 				if (c == '\n')
2257 					bare_lfs++;
2258 			if (c == '\r') {
2259 				byte_count++;
2260 				cp = c;
2261 				continue;
2262 			}
2263 
2264 			/* Check for EOF here in order not to lose last \r. */
2265 			if (c == EOF) {
2266 				if (feof(instr))	/* EOF */
2267 					break;
2268 				syslog(LOG_ERR, "Internal: impossible condition"
2269 						" on data stream after getc()");
2270 				goto data_err;
2271 			}
2272 
2273 			byte_count++;
2274 			FTPD_PUTC(c, outstr, file_err);
2275 			cp = c;
2276 		}
2277 #ifdef notyet	/* BSD stdio isn't ready for that */
2278 		while (fflush(outstr) == EOF) {
2279 			CHECKOOB(return (-1))
2280 			else
2281 				goto file_err;
2282 			clearerr(outstr);
2283 		}
2284 		ENDXFER;
2285 #else
2286 		ENDXFER;
2287 		if (fflush(outstr) == EOF)
2288 			goto file_err;
2289 #endif
2290 		if (bare_lfs) {
2291 			lreply(226,
2292 		"WARNING! %d bare linefeeds received in ASCII mode.",
2293 			    bare_lfs);
2294 		(void)printf("   File may not have transferred correctly.\r\n");
2295 		}
2296 		return (0);
2297 	default:
2298 		ENDXFER;
2299 		reply(550, "Unimplemented TYPE %d in receive_data.", type);
2300 		return (-1);
2301 	}
2302 
2303 data_err:
2304 	ENDXFER;
2305 	perror_reply(426, "Data connection");
2306 	return (-1);
2307 
2308 file_err:
2309 	ENDXFER;
2310 	perror_reply(452, "Error writing to file");
2311 	return (-1);
2312 }
2313 
2314 void
statfilecmd(char * filename)2315 statfilecmd(char *filename)
2316 {
2317 	FILE *fin;
2318 	int atstart;
2319 	int c, code;
2320 	char line[LINE_MAX];
2321 	struct stat st;
2322 
2323 	code = lstat(filename, &st) == 0 && S_ISDIR(st.st_mode) ? 212 : 213;
2324 	(void)snprintf(line, sizeof(line), _PATH_LS " -lA %s", filename);
2325 	fin = ftpd_popen(line, "r");
2326 	if (fin == NULL) {
2327 		perror_reply(551, filename);
2328 		return;
2329 	}
2330 	lreply(code, "Status of %s:", filename);
2331 	atstart = 1;
2332 	while ((c = getc(fin)) != EOF) {
2333 		if (c == '\n') {
2334 			if (ferror(stdout)){
2335 				perror_reply(421, "Control connection");
2336 				(void) ftpd_pclose(fin);
2337 				dologout(1);
2338 				/* NOTREACHED */
2339 			}
2340 			if (ferror(fin)) {
2341 				perror_reply(551, filename);
2342 				(void) ftpd_pclose(fin);
2343 				return;
2344 			}
2345 			(void) putc('\r', stdout);
2346 		}
2347 		/*
2348 		 * RFC 959 says neutral text should be prepended before
2349 		 * a leading 3-digit number followed by whitespace, but
2350 		 * many ftp clients can be confused by any leading digits,
2351 		 * as a matter of fact.
2352 		 */
2353 		if (atstart && isdigit(c))
2354 			(void) putc(' ', stdout);
2355 		(void) putc(c, stdout);
2356 		atstart = (c == '\n');
2357 	}
2358 	(void) ftpd_pclose(fin);
2359 	reply(code, "End of status.");
2360 }
2361 
2362 void
statcmd(void)2363 statcmd(void)
2364 {
2365 	union sockunion *su;
2366 	u_char *a, *p;
2367 	char hname[NI_MAXHOST];
2368 	int ispassive;
2369 
2370 	if (hostinfo) {
2371 		lreply(211, "%s FTP server status:", hostname);
2372 		printf("     %s\r\n", version);
2373 	} else
2374 		lreply(211, "FTP server status:");
2375 	printf("     Connected to %s", remotehost);
2376 	if (!getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
2377 			 hname, sizeof(hname) - 1, NULL, 0, NI_NUMERICHOST)) {
2378 		hname[sizeof(hname) - 1] = 0;
2379 		if (strcmp(hname, remotehost) != 0)
2380 			printf(" (%s)", hname);
2381 	}
2382 	printf("\r\n");
2383 	if (logged_in) {
2384 		if (guest)
2385 			printf("     Logged in anonymously\r\n");
2386 		else
2387 			printf("     Logged in as %s\r\n", pw->pw_name);
2388 	} else if (askpasswd)
2389 		printf("     Waiting for password\r\n");
2390 	else
2391 		printf("     Waiting for user name\r\n");
2392 	printf("     TYPE: %s", typenames[type]);
2393 	if (type == TYPE_A || type == TYPE_E)
2394 		printf(", FORM: %s", formnames[form]);
2395 	if (type == TYPE_L)
2396 #if CHAR_BIT == 8
2397 		printf(" %d", CHAR_BIT);
2398 #else
2399 		printf(" %d", bytesize);	/* need definition! */
2400 #endif
2401 	printf("; STRUcture: %s; transfer MODE: %s\r\n",
2402 	    strunames[stru], modenames[mode]);
2403 	if (data != -1)
2404 		printf("     Data connection open\r\n");
2405 	else if (pdata != -1) {
2406 		ispassive = 1;
2407 		su = &pasv_addr;
2408 		goto printaddr;
2409 	} else if (usedefault == 0) {
2410 		ispassive = 0;
2411 		su = &data_dest;
2412 printaddr:
2413 #define UC(b) (((int) b) & 0xff)
2414 		if (epsvall) {
2415 			printf("     EPSV only mode (EPSV ALL)\r\n");
2416 			goto epsvonly;
2417 		}
2418 
2419 		/* PORT/PASV */
2420 		if (su->su_family == AF_INET) {
2421 			a = (u_char *) &su->su_sin.sin_addr;
2422 			p = (u_char *) &su->su_sin.sin_port;
2423 			printf("     %s (%d,%d,%d,%d,%d,%d)\r\n",
2424 				ispassive ? "PASV" : "PORT",
2425 				UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
2426 				UC(p[0]), UC(p[1]));
2427 		}
2428 
2429 		/* LPRT/LPSV */
2430 	    {
2431 		int alen, af, i;
2432 
2433 		switch (su->su_family) {
2434 		case AF_INET:
2435 			a = (u_char *) &su->su_sin.sin_addr;
2436 			p = (u_char *) &su->su_sin.sin_port;
2437 			alen = sizeof(su->su_sin.sin_addr);
2438 			af = 4;
2439 			break;
2440 		case AF_INET6:
2441 			a = (u_char *) &su->su_sin6.sin6_addr;
2442 			p = (u_char *) &su->su_sin6.sin6_port;
2443 			alen = sizeof(su->su_sin6.sin6_addr);
2444 			af = 6;
2445 			break;
2446 		default:
2447 			af = 0;
2448 			break;
2449 		}
2450 		if (af) {
2451 			printf("     %s (%d,%d,", ispassive ? "LPSV" : "LPRT",
2452 				af, alen);
2453 			for (i = 0; i < alen; i++)
2454 				printf("%d,", UC(a[i]));
2455 			printf("%d,%d,%d)\r\n", 2, UC(p[0]), UC(p[1]));
2456 		}
2457 	    }
2458 
2459 epsvonly:;
2460 		/* EPRT/EPSV */
2461 	    {
2462 		int af;
2463 
2464 		switch (su->su_family) {
2465 		case AF_INET:
2466 			af = 1;
2467 			break;
2468 		case AF_INET6:
2469 			af = 2;
2470 			break;
2471 		default:
2472 			af = 0;
2473 			break;
2474 		}
2475 		if (af) {
2476 			union sockunion tmp;
2477 
2478 			tmp = *su;
2479 			if (tmp.su_family == AF_INET6)
2480 				tmp.su_sin6.sin6_scope_id = 0;
2481 			if (!getnameinfo((struct sockaddr *)&tmp, tmp.su_len,
2482 					hname, sizeof(hname) - 1, NULL, 0,
2483 					NI_NUMERICHOST)) {
2484 				hname[sizeof(hname) - 1] = 0;
2485 				printf("     %s |%d|%s|%d|\r\n",
2486 					ispassive ? "EPSV" : "EPRT",
2487 					af, hname, htons(tmp.su_port));
2488 			}
2489 		}
2490 	    }
2491 #undef UC
2492 	} else
2493 		printf("     No data connection\r\n");
2494 	reply(211, "End of status.");
2495 }
2496 
2497 void
fatalerror(char * s)2498 fatalerror(char *s)
2499 {
2500 
2501 	reply(451, "Error in server: %s", s);
2502 	reply(221, "Closing connection due to server error.");
2503 	dologout(0);
2504 	/* NOTREACHED */
2505 }
2506 
2507 void
reply(int n,const char * fmt,...)2508 reply(int n, const char *fmt, ...)
2509 {
2510 	va_list ap;
2511 
2512 	(void)printf("%d ", n);
2513 	va_start(ap, fmt);
2514 	(void)vprintf(fmt, ap);
2515 	va_end(ap);
2516 	(void)printf("\r\n");
2517 	(void)fflush(stdout);
2518 	if (ftpdebug) {
2519 		syslog(LOG_DEBUG, "<--- %d ", n);
2520 		va_start(ap, fmt);
2521 		vsyslog(LOG_DEBUG, fmt, ap);
2522 		va_end(ap);
2523 	}
2524 }
2525 
2526 void
lreply(int n,const char * fmt,...)2527 lreply(int n, const char *fmt, ...)
2528 {
2529 	va_list ap;
2530 
2531 	(void)printf("%d- ", n);
2532 	va_start(ap, fmt);
2533 	(void)vprintf(fmt, ap);
2534 	va_end(ap);
2535 	(void)printf("\r\n");
2536 	(void)fflush(stdout);
2537 	if (ftpdebug) {
2538 		syslog(LOG_DEBUG, "<--- %d- ", n);
2539 		va_start(ap, fmt);
2540 		vsyslog(LOG_DEBUG, fmt, ap);
2541 		va_end(ap);
2542 	}
2543 }
2544 
2545 static void
ack(char * s)2546 ack(char *s)
2547 {
2548 
2549 	reply(250, "%s command successful.", s);
2550 }
2551 
2552 void
nack(char * s)2553 nack(char *s)
2554 {
2555 
2556 	reply(502, "%s command not implemented.", s);
2557 }
2558 
2559 /* ARGSUSED */
2560 void
yyerror(char * s)2561 yyerror(char *s)
2562 {
2563 	char *cp;
2564 
2565 	if ((cp = strchr(cbuf,'\n')))
2566 		*cp = '\0';
2567 	reply(500, "%s: command not understood.", cbuf);
2568 }
2569 
2570 void
delete(char * name)2571 delete(char *name)
2572 {
2573 	struct stat st;
2574 
2575 	LOGCMD("delete", name);
2576 	if (lstat(name, &st) < 0) {
2577 		perror_reply(550, name);
2578 		return;
2579 	}
2580 	if (S_ISDIR(st.st_mode)) {
2581 		if (rmdir(name) < 0) {
2582 			perror_reply(550, name);
2583 			return;
2584 		}
2585 		goto done;
2586 	}
2587 	if (guest && noguestmod) {
2588 		reply(550, "Operation not permitted.");
2589 		return;
2590 	}
2591 	if (unlink(name) < 0) {
2592 		perror_reply(550, name);
2593 		return;
2594 	}
2595 done:
2596 	ack("DELE");
2597 }
2598 
2599 void
cwd(char * path)2600 cwd(char *path)
2601 {
2602 
2603 	if (chdir(path) < 0)
2604 		perror_reply(550, path);
2605 	else
2606 		ack("CWD");
2607 }
2608 
2609 void
makedir(char * name)2610 makedir(char *name)
2611 {
2612 	char *s;
2613 
2614 	LOGCMD("mkdir", name);
2615 	if (guest && noguestmkd)
2616 		reply(550, "Operation not permitted.");
2617 	else if (mkdir(name, 0777) < 0)
2618 		perror_reply(550, name);
2619 	else {
2620 		if ((s = doublequote(name)) == NULL)
2621 			fatalerror("Ran out of memory.");
2622 		reply(257, "\"%s\" directory created.", s);
2623 		free(s);
2624 	}
2625 }
2626 
2627 void
removedir(char * name)2628 removedir(char *name)
2629 {
2630 
2631 	LOGCMD("rmdir", name);
2632 	if (rmdir(name) < 0)
2633 		perror_reply(550, name);
2634 	else
2635 		ack("RMD");
2636 }
2637 
2638 void
pwd(void)2639 pwd(void)
2640 {
2641 	char *s, path[MAXPATHLEN + 1];
2642 
2643 	if (getcwd(path, sizeof(path)) == NULL)
2644 		perror_reply(550, "Get current directory");
2645 	else {
2646 		if ((s = doublequote(path)) == NULL)
2647 			fatalerror("Ran out of memory.");
2648 		reply(257, "\"%s\" is current directory.", s);
2649 		free(s);
2650 	}
2651 }
2652 
2653 char *
renamefrom(char * name)2654 renamefrom(char *name)
2655 {
2656 	struct stat st;
2657 
2658 	if (guest && noguestmod) {
2659 		reply(550, "Operation not permitted.");
2660 		return (NULL);
2661 	}
2662 	if (lstat(name, &st) < 0) {
2663 		perror_reply(550, name);
2664 		return (NULL);
2665 	}
2666 	reply(350, "File exists, ready for destination name.");
2667 	return (name);
2668 }
2669 
2670 void
renamecmd(char * from,char * to)2671 renamecmd(char *from, char *to)
2672 {
2673 	struct stat st;
2674 
2675 	LOGCMD2("rename", from, to);
2676 
2677 	if (guest && (stat(to, &st) == 0)) {
2678 		reply(550, "%s: permission denied.", to);
2679 		return;
2680 	}
2681 
2682 	if (rename(from, to) < 0)
2683 		perror_reply(550, "rename");
2684 	else
2685 		ack("RNTO");
2686 }
2687 
2688 static void
dolog(struct sockaddr * who)2689 dolog(struct sockaddr *who)
2690 {
2691 	char who_name[NI_MAXHOST];
2692 
2693 	realhostname_sa(remotehost, sizeof(remotehost) - 1, who, who->sa_len);
2694 	remotehost[sizeof(remotehost) - 1] = 0;
2695 	if (getnameinfo(who, who->sa_len,
2696 		who_name, sizeof(who_name) - 1, NULL, 0, NI_NUMERICHOST))
2697 			*who_name = 0;
2698 	who_name[sizeof(who_name) - 1] = 0;
2699 
2700 #ifdef SETPROCTITLE
2701 #ifdef VIRTUAL_HOSTING
2702 	if (thishost != firsthost)
2703 		snprintf(proctitle, sizeof(proctitle), "%s: connected (to %s)",
2704 			 remotehost, hostname);
2705 	else
2706 #endif
2707 		snprintf(proctitle, sizeof(proctitle), "%s: connected",
2708 			 remotehost);
2709 	setproctitle("%s", proctitle);
2710 #endif /* SETPROCTITLE */
2711 
2712 	if (logging) {
2713 #ifdef VIRTUAL_HOSTING
2714 		if (thishost != firsthost)
2715 			syslog(LOG_INFO, "connection from %s (%s) to %s",
2716 			       remotehost, who_name, hostname);
2717 		else
2718 #endif
2719 			syslog(LOG_INFO, "connection from %s (%s)",
2720 			       remotehost, who_name);
2721 	}
2722 }
2723 
2724 /*
2725  * Record logout in wtmp file
2726  * and exit with supplied status.
2727  */
2728 void
dologout(int status)2729 dologout(int status)
2730 {
2731 
2732 	if (logged_in && dowtmp) {
2733 		(void) seteuid(0);
2734 #ifdef		LOGIN_CAP
2735  	        setusercontext(NULL, getpwuid(0), 0, LOGIN_SETALL & ~(LOGIN_SETLOGIN |
2736 		       LOGIN_SETUSER | LOGIN_SETGROUP | LOGIN_SETPATH |
2737 		       LOGIN_SETENV));
2738 #endif
2739 		ftpd_logwtmp(wtmpid, NULL, NULL);
2740 	}
2741 	/* beware of flushing buffers after a SIGPIPE */
2742 	_exit(status);
2743 }
2744 
2745 static void
sigurg(int signo)2746 sigurg(int signo)
2747 {
2748 
2749 	recvurg = 1;
2750 }
2751 
2752 static void
maskurg(int flag)2753 maskurg(int flag)
2754 {
2755 	int oerrno;
2756 	sigset_t sset;
2757 
2758 	if (!transflag) {
2759 		syslog(LOG_ERR, "Internal: maskurg() while no transfer");
2760 		return;
2761 	}
2762 	oerrno = errno;
2763 	sigemptyset(&sset);
2764 	sigaddset(&sset, SIGURG);
2765 	sigprocmask(flag ? SIG_BLOCK : SIG_UNBLOCK, &sset, NULL);
2766 	errno = oerrno;
2767 }
2768 
2769 static void
flagxfer(int flag)2770 flagxfer(int flag)
2771 {
2772 
2773 	if (flag) {
2774 		if (transflag)
2775 			syslog(LOG_ERR, "Internal: flagxfer(1): "
2776 					"transfer already under way");
2777 		transflag = 1;
2778 		maskurg(0);
2779 		recvurg = 0;
2780 	} else {
2781 		if (!transflag)
2782 			syslog(LOG_ERR, "Internal: flagxfer(0): "
2783 					"no active transfer");
2784 		maskurg(1);
2785 		transflag = 0;
2786 	}
2787 }
2788 
2789 /*
2790  * Returns 0 if OK to resume or -1 if abort requested.
2791  */
2792 static int
myoob(void)2793 myoob(void)
2794 {
2795 	char *cp;
2796 	int ret;
2797 
2798 	if (!transflag) {
2799 		syslog(LOG_ERR, "Internal: myoob() while no transfer");
2800 		return (0);
2801 	}
2802 	cp = tmpline;
2803 	ret = get_line(cp, 7, stdin);
2804 	if (ret == -1) {
2805 		reply(221, "You could at least say goodbye.");
2806 		dologout(0);
2807 	} else if (ret == -2) {
2808 		/* Ignore truncated command. */
2809 		return (0);
2810 	}
2811 	upper(cp);
2812 	if (strcmp(cp, "ABOR\r\n") == 0) {
2813 		tmpline[0] = '\0';
2814 		reply(426, "Transfer aborted. Data connection closed.");
2815 		reply(226, "Abort successful.");
2816 		return (-1);
2817 	}
2818 	if (strcmp(cp, "STAT\r\n") == 0) {
2819 		tmpline[0] = '\0';
2820 		if (file_size != -1)
2821 			reply(213, "Status: %jd of %jd bytes transferred.",
2822 				   (intmax_t)byte_count, (intmax_t)file_size);
2823 		else
2824 			reply(213, "Status: %jd bytes transferred.",
2825 				   (intmax_t)byte_count);
2826 	}
2827 	return (0);
2828 }
2829 
2830 /*
2831  * Note: a response of 425 is not mentioned as a possible response to
2832  *	the PASV command in RFC959. However, it has been blessed as
2833  *	a legitimate response by Jon Postel in a telephone conversation
2834  *	with Rick Adams on 25 Jan 89.
2835  */
2836 void
passive(void)2837 passive(void)
2838 {
2839 	socklen_t len;
2840 	int on;
2841 	char *p, *a;
2842 
2843 	if (pdata >= 0)		/* close old port if one set */
2844 		close(pdata);
2845 
2846 	pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2847 	if (pdata < 0) {
2848 		perror_reply(425, "Can't open passive connection");
2849 		return;
2850 	}
2851 	on = 1;
2852 	if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2853 		syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2854 
2855 	(void) seteuid(0);
2856 
2857 #ifdef IP_PORTRANGE
2858 	if (ctrl_addr.su_family == AF_INET) {
2859 	    on = restricted_data_ports ? IP_PORTRANGE_HIGH
2860 				       : IP_PORTRANGE_DEFAULT;
2861 
2862 	    if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2863 			    &on, sizeof(on)) < 0)
2864 		    goto pasv_error;
2865 	}
2866 #endif
2867 #ifdef IPV6_PORTRANGE
2868 	if (ctrl_addr.su_family == AF_INET6) {
2869 	    on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
2870 				       : IPV6_PORTRANGE_DEFAULT;
2871 
2872 	    if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2873 			    &on, sizeof(on)) < 0)
2874 		    goto pasv_error;
2875 	}
2876 #endif
2877 
2878 	pasv_addr = ctrl_addr;
2879 	pasv_addr.su_port = 0;
2880 	if (bind(pdata, (struct sockaddr *)&pasv_addr, pasv_addr.su_len) < 0)
2881 		goto pasv_error;
2882 
2883 	(void) seteuid(pw->pw_uid);
2884 
2885 	len = sizeof(pasv_addr);
2886 	if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
2887 		goto pasv_error;
2888 	if (listen(pdata, 1) < 0)
2889 		goto pasv_error;
2890 	if (pasv_addr.su_family == AF_INET)
2891 		a = (char *) &pasv_addr.su_sin.sin_addr;
2892 	else if (pasv_addr.su_family == AF_INET6 &&
2893 		 IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr))
2894 		a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
2895 	else
2896 		goto pasv_error;
2897 
2898 	p = (char *) &pasv_addr.su_port;
2899 
2900 #define UC(b) (((int) b) & 0xff)
2901 
2902 	reply(227, "Entering Passive Mode (%d,%d,%d,%d,%d,%d)", UC(a[0]),
2903 		UC(a[1]), UC(a[2]), UC(a[3]), UC(p[0]), UC(p[1]));
2904 	return;
2905 
2906 pasv_error:
2907 	(void) seteuid(pw->pw_uid);
2908 	(void) close(pdata);
2909 	pdata = -1;
2910 	perror_reply(425, "Can't open passive connection");
2911 	return;
2912 }
2913 
2914 /*
2915  * Long Passive defined in RFC 1639.
2916  *     228 Entering Long Passive Mode
2917  *         (af, hal, h1, h2, h3,..., pal, p1, p2...)
2918  */
2919 
2920 void
long_passive(char * cmd,int pf)2921 long_passive(char *cmd, int pf)
2922 {
2923 	socklen_t len;
2924 	int on;
2925 	char *p, *a;
2926 
2927 	if (pdata >= 0)		/* close old port if one set */
2928 		close(pdata);
2929 
2930 	if (pf != PF_UNSPEC) {
2931 		if (ctrl_addr.su_family != pf) {
2932 			switch (ctrl_addr.su_family) {
2933 			case AF_INET:
2934 				pf = 1;
2935 				break;
2936 			case AF_INET6:
2937 				pf = 2;
2938 				break;
2939 			default:
2940 				pf = 0;
2941 				break;
2942 			}
2943 			/*
2944 			 * XXX
2945 			 * only EPRT/EPSV ready clients will understand this
2946 			 */
2947 			if (strcmp(cmd, "EPSV") == 0 && pf) {
2948 				reply(522, "Network protocol mismatch, "
2949 					"use (%d)", pf);
2950 			} else
2951 				reply(501, "Network protocol mismatch."); /*XXX*/
2952 
2953 			return;
2954 		}
2955 	}
2956 
2957 	pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2958 	if (pdata < 0) {
2959 		perror_reply(425, "Can't open passive connection");
2960 		return;
2961 	}
2962 	on = 1;
2963 	if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2964 		syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2965 
2966 	(void) seteuid(0);
2967 
2968 	pasv_addr = ctrl_addr;
2969 	pasv_addr.su_port = 0;
2970 	len = pasv_addr.su_len;
2971 
2972 #ifdef IP_PORTRANGE
2973 	if (ctrl_addr.su_family == AF_INET) {
2974 	    on = restricted_data_ports ? IP_PORTRANGE_HIGH
2975 				       : IP_PORTRANGE_DEFAULT;
2976 
2977 	    if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2978 			    &on, sizeof(on)) < 0)
2979 		    goto pasv_error;
2980 	}
2981 #endif
2982 #ifdef IPV6_PORTRANGE
2983 	if (ctrl_addr.su_family == AF_INET6) {
2984 	    on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
2985 				       : IPV6_PORTRANGE_DEFAULT;
2986 
2987 	    if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2988 			    &on, sizeof(on)) < 0)
2989 		    goto pasv_error;
2990 	}
2991 #endif
2992 
2993 	if (bind(pdata, (struct sockaddr *)&pasv_addr, len) < 0)
2994 		goto pasv_error;
2995 
2996 	(void) seteuid(pw->pw_uid);
2997 
2998 	if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
2999 		goto pasv_error;
3000 	if (listen(pdata, 1) < 0)
3001 		goto pasv_error;
3002 
3003 #define UC(b) (((int) b) & 0xff)
3004 
3005 	if (strcmp(cmd, "LPSV") == 0) {
3006 		p = (char *)&pasv_addr.su_port;
3007 		switch (pasv_addr.su_family) {
3008 		case AF_INET:
3009 			a = (char *) &pasv_addr.su_sin.sin_addr;
3010 		v4_reply:
3011 			reply(228,
3012 "Entering Long Passive Mode (%d,%d,%d,%d,%d,%d,%d,%d,%d)",
3013 			      4, 4, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
3014 			      2, UC(p[0]), UC(p[1]));
3015 			return;
3016 		case AF_INET6:
3017 			if (IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr)) {
3018 				a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
3019 				goto v4_reply;
3020 			}
3021 			a = (char *) &pasv_addr.su_sin6.sin6_addr;
3022 			reply(228,
3023 "Entering Long Passive Mode "
3024 "(%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d)",
3025 			      6, 16, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
3026 			      UC(a[4]), UC(a[5]), UC(a[6]), UC(a[7]),
3027 			      UC(a[8]), UC(a[9]), UC(a[10]), UC(a[11]),
3028 			      UC(a[12]), UC(a[13]), UC(a[14]), UC(a[15]),
3029 			      2, UC(p[0]), UC(p[1]));
3030 			return;
3031 		}
3032 	} else if (strcmp(cmd, "EPSV") == 0) {
3033 		switch (pasv_addr.su_family) {
3034 		case AF_INET:
3035 		case AF_INET6:
3036 			reply(229, "Entering Extended Passive Mode (|||%d|)",
3037 				ntohs(pasv_addr.su_port));
3038 			return;
3039 		}
3040 	} else {
3041 		/* more proper error code? */
3042 	}
3043 
3044 pasv_error:
3045 	(void) seteuid(pw->pw_uid);
3046 	(void) close(pdata);
3047 	pdata = -1;
3048 	perror_reply(425, "Can't open passive connection");
3049 	return;
3050 }
3051 
3052 /*
3053  * Generate unique name for file with basename "local"
3054  * and open the file in order to avoid possible races.
3055  * Try "local" first, then "local.1", "local.2" etc, up to "local.99".
3056  * Return descriptor to the file, set "name" to its name.
3057  *
3058  * Generates failure reply on error.
3059  */
3060 static int
guniquefd(char * local,char ** name)3061 guniquefd(char *local, char **name)
3062 {
3063 	static char new[MAXPATHLEN];
3064 	struct stat st;
3065 	char *cp;
3066 	int count;
3067 	int fd;
3068 
3069 	cp = strrchr(local, '/');
3070 	if (cp)
3071 		*cp = '\0';
3072 	if (stat(cp ? local : ".", &st) < 0) {
3073 		perror_reply(553, cp ? local : ".");
3074 		return (-1);
3075 	}
3076 	if (cp) {
3077 		/*
3078 		 * Let not overwrite dirname with counter suffix.
3079 		 * -4 is for /nn\0
3080 		 * In this extreme case dot won't be put in front of suffix.
3081 		 */
3082 		if (strlen(local) > sizeof(new) - 4) {
3083 			reply(553, "Pathname too long.");
3084 			return (-1);
3085 		}
3086 		*cp = '/';
3087 	}
3088 	/* -4 is for the .nn<null> we put on the end below */
3089 	(void) snprintf(new, sizeof(new) - 4, "%s", local);
3090 	cp = new + strlen(new);
3091 	/*
3092 	 * Don't generate dotfile unless requested explicitly.
3093 	 * This covers the case when basename gets truncated off
3094 	 * by buffer size.
3095 	 */
3096 	if (cp > new && cp[-1] != '/')
3097 		*cp++ = '.';
3098 	for (count = 0; count < 100; count++) {
3099 		/* At count 0 try unmodified name */
3100 		if (count)
3101 			(void)sprintf(cp, "%d", count);
3102 		if ((fd = open(count ? new : local,
3103 		    O_RDWR | O_CREAT | O_EXCL, 0666)) >= 0) {
3104 			*name = count ? new : local;
3105 			return (fd);
3106 		}
3107 		if (errno != EEXIST) {
3108 			perror_reply(553, count ? new : local);
3109 			return (-1);
3110 		}
3111 	}
3112 	reply(452, "Unique file name cannot be created.");
3113 	return (-1);
3114 }
3115 
3116 /*
3117  * Format and send reply containing system error number.
3118  */
3119 void
perror_reply(int code,char * string)3120 perror_reply(int code, char *string)
3121 {
3122 
3123 	reply(code, "%s: %s.", string, strerror(errno));
3124 }
3125 
3126 static char *onefile[] = {
3127 	"",
3128 	0
3129 };
3130 
3131 void
send_file_list(char * whichf)3132 send_file_list(char *whichf)
3133 {
3134 	struct stat st;
3135 	DIR *dirp = NULL;
3136 	struct dirent *dir;
3137 	FILE *dout = NULL;
3138 	char **dirlist, *dirname;
3139 	int simple = 0;
3140 	int freeglob = 0;
3141 	glob_t gl;
3142 
3143 	if (strpbrk(whichf, "~{[*?") != NULL) {
3144 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE;
3145 
3146 		memset(&gl, 0, sizeof(gl));
3147 		gl.gl_matchc = MAXGLOBARGS;
3148 		flags |= GLOB_LIMIT;
3149 		freeglob = 1;
3150 		if (glob(whichf, flags, 0, &gl)) {
3151 			reply(550, "No matching files found.");
3152 			goto out;
3153 		} else if (gl.gl_pathc == 0) {
3154 			errno = ENOENT;
3155 			perror_reply(550, whichf);
3156 			goto out;
3157 		}
3158 		dirlist = gl.gl_pathv;
3159 	} else {
3160 		onefile[0] = whichf;
3161 		dirlist = onefile;
3162 		simple = 1;
3163 	}
3164 
3165 	while ((dirname = *dirlist++)) {
3166 		if (stat(dirname, &st) < 0) {
3167 			/*
3168 			 * If user typed "ls -l", etc, and the client
3169 			 * used NLST, do what the user meant.
3170 			 */
3171 			if (dirname[0] == '-' && *dirlist == NULL &&
3172 			    dout == NULL)
3173 				retrieve(_PATH_LS " %s", dirname);
3174 			else
3175 				perror_reply(550, whichf);
3176 			goto out;
3177 		}
3178 
3179 		if (S_ISREG(st.st_mode)) {
3180 			if (dout == NULL) {
3181 				dout = dataconn("file list", -1, "w");
3182 				if (dout == NULL)
3183 					goto out;
3184 				STARTXFER;
3185 			}
3186 			START_UNSAFE;
3187 			fprintf(dout, "%s%s\n", dirname,
3188 				type == TYPE_A ? "\r" : "");
3189 			END_UNSAFE;
3190 			if (ferror(dout))
3191 				goto data_err;
3192 			byte_count += strlen(dirname) +
3193 				      (type == TYPE_A ? 2 : 1);
3194 			CHECKOOB(goto abrt);
3195 			continue;
3196 		} else if (!S_ISDIR(st.st_mode))
3197 			continue;
3198 
3199 		if ((dirp = opendir(dirname)) == NULL)
3200 			continue;
3201 
3202 		while ((dir = readdir(dirp)) != NULL) {
3203 			char nbuf[MAXPATHLEN];
3204 
3205 			CHECKOOB(goto abrt);
3206 
3207 			if (dir->d_name[0] == '.' && dir->d_namlen == 1)
3208 				continue;
3209 			if (dir->d_name[0] == '.' && dir->d_name[1] == '.' &&
3210 			    dir->d_namlen == 2)
3211 				continue;
3212 
3213 			snprintf(nbuf, sizeof(nbuf),
3214 				"%s/%s", dirname, dir->d_name);
3215 
3216 			/*
3217 			 * We have to do a stat to insure it's
3218 			 * not a directory or special file.
3219 			 */
3220 			if (simple || (stat(nbuf, &st) == 0 &&
3221 			    S_ISREG(st.st_mode))) {
3222 				if (dout == NULL) {
3223 					dout = dataconn("file list", -1, "w");
3224 					if (dout == NULL)
3225 						goto out;
3226 					STARTXFER;
3227 				}
3228 				START_UNSAFE;
3229 				if (nbuf[0] == '.' && nbuf[1] == '/')
3230 					fprintf(dout, "%s%s\n", &nbuf[2],
3231 						type == TYPE_A ? "\r" : "");
3232 				else
3233 					fprintf(dout, "%s%s\n", nbuf,
3234 						type == TYPE_A ? "\r" : "");
3235 				END_UNSAFE;
3236 				if (ferror(dout))
3237 					goto data_err;
3238 				byte_count += strlen(nbuf) +
3239 					      (type == TYPE_A ? 2 : 1);
3240 				CHECKOOB(goto abrt);
3241 			}
3242 		}
3243 		(void) closedir(dirp);
3244 		dirp = NULL;
3245 	}
3246 
3247 	if (dout == NULL)
3248 		reply(550, "No files found.");
3249 	else if (ferror(dout))
3250 data_err:	perror_reply(550, "Data connection");
3251 	else
3252 		reply(226, "Transfer complete.");
3253 out:
3254 	if (dout) {
3255 		ENDXFER;
3256 abrt:
3257 		(void) fclose(dout);
3258 		data = -1;
3259 		pdata = -1;
3260 	}
3261 	if (dirp)
3262 		(void) closedir(dirp);
3263 	if (freeglob) {
3264 		freeglob = 0;
3265 		globfree(&gl);
3266 	}
3267 }
3268 
3269 void
reapchild(int signo)3270 reapchild(int signo)
3271 {
3272 	while (waitpid(-1, NULL, WNOHANG) > 0);
3273 }
3274 
3275 static void
appendf(char ** strp,char * fmt,...)3276 appendf(char **strp, char *fmt, ...)
3277 {
3278 	va_list ap;
3279 	char *ostr, *p;
3280 
3281 	va_start(ap, fmt);
3282 	vasprintf(&p, fmt, ap);
3283 	va_end(ap);
3284 	if (p == NULL)
3285 		fatalerror("Ran out of memory.");
3286 	if (*strp == NULL)
3287 		*strp = p;
3288 	else {
3289 		ostr = *strp;
3290 		asprintf(strp, "%s%s", ostr, p);
3291 		if (*strp == NULL)
3292 			fatalerror("Ran out of memory.");
3293 		free(ostr);
3294 	}
3295 }
3296 
3297 static void
logcmd(char * cmd,char * file1,char * file2,off_t cnt)3298 logcmd(char *cmd, char *file1, char *file2, off_t cnt)
3299 {
3300 	char *msg = NULL;
3301 	char wd[MAXPATHLEN + 1];
3302 
3303 	if (logging <= 1)
3304 		return;
3305 
3306 	if (getcwd(wd, sizeof(wd) - 1) == NULL)
3307 		strcpy(wd, strerror(errno));
3308 
3309 	appendf(&msg, "%s", cmd);
3310 	if (file1)
3311 		appendf(&msg, " %s", file1);
3312 	if (file2)
3313 		appendf(&msg, " %s", file2);
3314 	if (cnt >= 0)
3315 		appendf(&msg, " = %jd bytes", (intmax_t)cnt);
3316 	appendf(&msg, " (wd: %s", wd);
3317 	if (guest || dochroot)
3318 		appendf(&msg, "; chrooted");
3319 	appendf(&msg, ")");
3320 	syslog(LOG_INFO, "%s", msg);
3321 	free(msg);
3322 }
3323 
3324 static void
logxfer(char * name,off_t size,time_t start)3325 logxfer(char *name, off_t size, time_t start)
3326 {
3327 	char buf[MAXPATHLEN + 1024];
3328 	char path[MAXPATHLEN + 1];
3329 	time_t now;
3330 
3331 	if (statfd >= 0) {
3332 		time(&now);
3333 		if (realpath(name, path) == NULL) {
3334 			syslog(LOG_NOTICE, "realpath failed on %s: %m", path);
3335 			return;
3336 		}
3337 		snprintf(buf, sizeof(buf), "%.20s!%s!%s!%s!%jd!%ld\n",
3338 			ctime(&now)+4, ident, remotehost,
3339 			path, (intmax_t)size,
3340 			(long)(now - start + (now == start)));
3341 		write(statfd, buf, strlen(buf));
3342 	}
3343 }
3344 
3345 static char *
doublequote(char * s)3346 doublequote(char *s)
3347 {
3348 	int n;
3349 	char *p, *s2;
3350 
3351 	for (p = s, n = 0; *p; p++)
3352 		if (*p == '"')
3353 			n++;
3354 
3355 	if ((s2 = malloc(p - s + n + 1)) == NULL)
3356 		return (NULL);
3357 
3358 	for (p = s2; *s; s++, p++) {
3359 		if ((*p = *s) == '"')
3360 			*(++p) = '"';
3361 	}
3362 	*p = '\0';
3363 
3364 	return (s2);
3365 }
3366 
3367 /* setup server socket for specified address family */
3368 /* if af is PF_UNSPEC more than one socket may be returned */
3369 /* the returned list is dynamically allocated, so caller needs to free it */
3370 static int *
socksetup(int af,char * bindname,const char * bindport)3371 socksetup(int af, char *bindname, const char *bindport)
3372 {
3373 	struct addrinfo hints, *res, *r;
3374 	int error, maxs, *s, *socks;
3375 	const int on = 1;
3376 
3377 	memset(&hints, 0, sizeof(hints));
3378 	hints.ai_flags = AI_PASSIVE;
3379 	hints.ai_family = af;
3380 	hints.ai_socktype = SOCK_STREAM;
3381 	error = getaddrinfo(bindname, bindport, &hints, &res);
3382 	if (error) {
3383 		syslog(LOG_ERR, "%s", gai_strerror(error));
3384 		if (error == EAI_SYSTEM)
3385 			syslog(LOG_ERR, "%s", strerror(errno));
3386 		return NULL;
3387 	}
3388 
3389 	/* Count max number of sockets we may open */
3390 	for (maxs = 0, r = res; r; r = r->ai_next, maxs++)
3391 		;
3392 	socks = malloc((maxs + 1) * sizeof(int));
3393 	if (!socks) {
3394 		freeaddrinfo(res);
3395 		syslog(LOG_ERR, "couldn't allocate memory for sockets");
3396 		return NULL;
3397 	}
3398 
3399 	*socks = 0;   /* num of sockets counter at start of array */
3400 	s = socks + 1;
3401 	for (r = res; r; r = r->ai_next) {
3402 		*s = socket(r->ai_family, r->ai_socktype, r->ai_protocol);
3403 		if (*s < 0) {
3404 			syslog(LOG_DEBUG, "control socket: %m");
3405 			continue;
3406 		}
3407 		if (setsockopt(*s, SOL_SOCKET, SO_REUSEADDR,
3408 		    &on, sizeof(on)) < 0)
3409 			syslog(LOG_WARNING,
3410 			    "control setsockopt (SO_REUSEADDR): %m");
3411 		if (r->ai_family == AF_INET6) {
3412 			if (setsockopt(*s, IPPROTO_IPV6, IPV6_V6ONLY,
3413 			    &on, sizeof(on)) < 0)
3414 				syslog(LOG_WARNING,
3415 				    "control setsockopt (IPV6_V6ONLY): %m");
3416 		}
3417 		if (bind(*s, r->ai_addr, r->ai_addrlen) < 0) {
3418 			syslog(LOG_DEBUG, "control bind: %m");
3419 			close(*s);
3420 			continue;
3421 		}
3422 		(*socks)++;
3423 		s++;
3424 	}
3425 
3426 	if (res)
3427 		freeaddrinfo(res);
3428 
3429 	if (*socks == 0) {
3430 		syslog(LOG_ERR, "control socket: Couldn't bind to any socket");
3431 		free(socks);
3432 		return NULL;
3433 	}
3434 	return(socks);
3435 }
3436