xref: /original-bsd/libexec/ftpd/ftpd.c (revision e61fc7ea)
1 /*
2  * Copyright (c) 1985, 1988, 1990 Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #ifndef lint
9 char copyright[] =
10 "@(#) Copyright (c) 1985, 1988, 1990 Regents of the University of California.\n\
11  All rights reserved.\n";
12 #endif /* not lint */
13 
14 #ifndef lint
15 static char sccsid[] = "@(#)ftpd.c	5.37 (Berkeley) 06/27/90";
16 #endif /* not lint */
17 
18 /*
19  * FTP server.
20  */
21 #include <sys/param.h>
22 #include <sys/stat.h>
23 #include <sys/ioctl.h>
24 #include <sys/socket.h>
25 #include <sys/file.h>
26 #include <sys/wait.h>
27 #include <sys/dir.h>
28 
29 #include <netinet/in.h>
30 #include <netinet/in_systm.h>
31 #include <netinet/ip.h>
32 
33 #define	FTP_NAMES
34 #include <arpa/ftp.h>
35 #include <arpa/inet.h>
36 #include <arpa/telnet.h>
37 
38 #include <ctype.h>
39 #include <stdio.h>
40 #include <signal.h>
41 #include <pwd.h>
42 #include <setjmp.h>
43 #include <netdb.h>
44 #include <errno.h>
45 #include <string.h>
46 #include <syslog.h>
47 #include <varargs.h>
48 #include "pathnames.h"
49 
50 /*
51  * File containing login names
52  * NOT to be used on this machine.
53  * Commonly used to disallow uucp.
54  */
55 extern	int errno;
56 extern	char *crypt();
57 extern	char version[];
58 extern	char *home;		/* pointer to home directory for glob */
59 extern	FILE *ftpd_popen(), *fopen(), *freopen();
60 extern	int  ftpd_pclose(), fclose();
61 extern	char *getline();
62 extern	char cbuf[];
63 extern	off_t restart_point;
64 
65 struct	sockaddr_in ctrl_addr;
66 struct	sockaddr_in data_source;
67 struct	sockaddr_in data_dest;
68 struct	sockaddr_in his_addr;
69 struct	sockaddr_in pasv_addr;
70 
71 int	data;
72 jmp_buf	errcatch, urgcatch;
73 int	logged_in;
74 struct	passwd *pw;
75 int	debug;
76 int	timeout = 900;    /* timeout after 15 minutes of inactivity */
77 int	maxtimeout = 7200;/* don't allow idle time to be set beyond 2 hours */
78 int	logging;
79 int	guest;
80 int	type;
81 int	form;
82 int	stru;			/* avoid C keyword */
83 int	mode;
84 int	usedefault = 1;		/* for data transfers */
85 int	pdata = -1;		/* for passive mode */
86 int	transflag;
87 off_t	file_size;
88 off_t	byte_count;
89 #if !defined(CMASK) || CMASK == 0
90 #undef CMASK
91 #define CMASK 027
92 #endif
93 int	defumask = CMASK;		/* default umask value */
94 char	tmpline[7];
95 char	hostname[MAXHOSTNAMELEN];
96 char	remotehost[MAXHOSTNAMELEN];
97 
98 /*
99  * Timeout intervals for retrying connections
100  * to hosts that don't accept PORT cmds.  This
101  * is a kludge, but given the problems with TCP...
102  */
103 #define	SWAITMAX	90	/* wait at most 90 seconds */
104 #define	SWAITINT	5	/* interval between retries */
105 
106 int	swaitmax = SWAITMAX;
107 int	swaitint = SWAITINT;
108 
109 int	lostconn();
110 int	myoob();
111 FILE	*getdatasock(), *dataconn();
112 
113 #ifdef SETPROCTITLE
114 char	**Argv = NULL;		/* pointer to argument vector */
115 char	*LastArgv = NULL;	/* end of argv */
116 char	proctitle[BUFSIZ];	/* initial part of title */
117 #endif /* SETPROCTITLE */
118 
119 main(argc, argv, envp)
120 	int argc;
121 	char *argv[];
122 	char **envp;
123 {
124 	int addrlen, on = 1, tos;
125 	char *cp;
126 
127 	addrlen = sizeof (his_addr);
128 	if (getpeername(0, (struct sockaddr *)&his_addr, &addrlen) < 0) {
129 		syslog(LOG_ERR, "getpeername (%s): %m",argv[0]);
130 		exit(1);
131 	}
132 	addrlen = sizeof (ctrl_addr);
133 	if (getsockname(0, (struct sockaddr *)&ctrl_addr, &addrlen) < 0) {
134 		syslog(LOG_ERR, "getsockname (%s): %m",argv[0]);
135 		exit(1);
136 	}
137 #ifdef IP_TOS
138 	tos = IPTOS_LOWDELAY;
139 	if (setsockopt(0, IPPROTO_IP, IP_TOS, (char *)&tos, sizeof(int)) < 0)
140 		syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
141 #endif
142 	data_source.sin_port = htons(ntohs(ctrl_addr.sin_port) - 1);
143 	debug = 0;
144 	openlog("ftpd", LOG_PID, LOG_DAEMON);
145 #ifdef SETPROCTITLE
146 	/*
147 	 *  Save start and extent of argv for setproctitle.
148 	 */
149 	Argv = argv;
150 	while (*envp)
151 		envp++;
152 	LastArgv = envp[-1] + strlen(envp[-1]);
153 #endif /* SETPROCTITLE */
154 
155 	argc--, argv++;
156 	while (argc > 0 && *argv[0] == '-') {
157 		for (cp = &argv[0][1]; *cp; cp++) switch (*cp) {
158 
159 		case 'v':
160 			debug = 1;
161 			break;
162 
163 		case 'd':
164 			debug = 1;
165 			break;
166 
167 		case 'l':
168 			logging = 1;
169 			break;
170 
171 		case 't':
172 			timeout = atoi(++cp);
173 			if (maxtimeout < timeout)
174 				maxtimeout = timeout;
175 			goto nextopt;
176 
177 		case 'T':
178 			maxtimeout = atoi(++cp);
179 			if (timeout > maxtimeout)
180 				timeout = maxtimeout;
181 			goto nextopt;
182 
183 		case 'u':
184 		    {
185 			int val = 0;
186 
187 			while (*++cp && *cp >= '0' && *cp <= '9')
188 				val = val*8 + *cp - '0';
189 			if (*cp)
190 				fprintf(stderr, "ftpd: Bad value for -u\n");
191 			else
192 				defumask = val;
193 			goto nextopt;
194 		    }
195 
196 		default:
197 			fprintf(stderr, "ftpd: Unknown flag -%c ignored.\n",
198 			     *cp);
199 			break;
200 		}
201 nextopt:
202 		argc--, argv++;
203 	}
204 	(void) freopen(_PATH_DEVNULL, "w", stderr);
205 	(void) signal(SIGPIPE, lostconn);
206 	(void) signal(SIGCHLD, SIG_IGN);
207 	if ((int)signal(SIGURG, myoob) < 0)
208 		syslog(LOG_ERR, "signal: %m");
209 
210 	/* Try to handle urgent data inline */
211 #ifdef SO_OOBINLINE
212 	if (setsockopt(0, SOL_SOCKET, SO_OOBINLINE, (char *)&on, sizeof(on)) < 0)
213 		syslog(LOG_ERR, "setsockopt: %m");
214 #endif
215 
216 #ifdef	F_SETOWN
217 	if (fcntl(fileno(stdin), F_SETOWN, getpid()) == -1)
218 		syslog(LOG_ERR, "fcntl F_SETOWN: %m");
219 #endif
220 	dolog(&his_addr);
221 	/*
222 	 * Set up default state
223 	 */
224 	data = -1;
225 	type = TYPE_A;
226 	form = FORM_N;
227 	stru = STRU_F;
228 	mode = MODE_S;
229 	tmpline[0] = '\0';
230 	(void) gethostname(hostname, sizeof (hostname));
231 	reply(220, "%s FTP server (%s) ready.", hostname, version);
232 	(void) setjmp(errcatch);
233 	for (;;)
234 		(void) yyparse();
235 	/* NOTREACHED */
236 }
237 
238 lostconn()
239 {
240 
241 	if (debug)
242 		syslog(LOG_DEBUG, "lost connection");
243 	dologout(-1);
244 }
245 
246 static char ttyline[20];
247 
248 /*
249  * Helper function for sgetpwnam().
250  */
251 char *
252 sgetsave(s)
253 	char *s;
254 {
255 	char *malloc();
256 	char *new = malloc((unsigned) strlen(s) + 1);
257 
258 	if (new == NULL) {
259 		perror_reply(421, "Local resource failure: malloc");
260 		dologout(1);
261 		/* NOTREACHED */
262 	}
263 	(void) strcpy(new, s);
264 	return (new);
265 }
266 
267 /*
268  * Save the result of a getpwnam.  Used for USER command, since
269  * the data returned must not be clobbered by any other command
270  * (e.g., globbing).
271  */
272 struct passwd *
273 sgetpwnam(name)
274 	char *name;
275 {
276 	static struct passwd save;
277 	register struct passwd *p;
278 	char *sgetsave();
279 
280 	if ((p = getpwnam(name)) == NULL)
281 		return (p);
282 	if (save.pw_name) {
283 		free(save.pw_name);
284 		free(save.pw_passwd);
285 		free(save.pw_gecos);
286 		free(save.pw_dir);
287 		free(save.pw_shell);
288 	}
289 	save = *p;
290 	save.pw_name = sgetsave(p->pw_name);
291 	save.pw_passwd = sgetsave(p->pw_passwd);
292 	save.pw_gecos = sgetsave(p->pw_gecos);
293 	save.pw_dir = sgetsave(p->pw_dir);
294 	save.pw_shell = sgetsave(p->pw_shell);
295 	return (&save);
296 }
297 
298 int login_attempts;		/* number of failed login attempts */
299 int askpasswd;			/* had user command, ask for passwd */
300 
301 /*
302  * USER command.
303  * Sets global passwd pointer pw if named account exists and is acceptable;
304  * sets askpasswd if a PASS command is expected.  If logged in previously,
305  * need to reset state.  If name is "ftp" or "anonymous", the name is not in
306  * _PATH_FTPUSERS, and ftp account exists, set guest and pw, then just return.
307  * If account doesn't exist, ask for passwd anyway.  Otherwise, check user
308  * requesting login privileges.  Disallow anyone who does not have a standard
309  * shell as returned by getusershell().  Disallow anyone mentioned in the file
310  * _PATH_FTPUSERS to allow people such as root and uucp to be avoided.
311  */
312 user(name)
313 	char *name;
314 {
315 	register char *cp;
316 	char *shell;
317 	char *getusershell();
318 
319 	if (logged_in) {
320 		if (guest) {
321 			reply(530, "Can't change user from guest login.");
322 			return;
323 		}
324 		end_login();
325 	}
326 
327 	guest = 0;
328 	if (strcmp(name, "ftp") == 0 || strcmp(name, "anonymous") == 0) {
329 		if (checkuser("ftp") || checkuser("anonymous"))
330 			reply(530, "User %s access denied.", name);
331 		else if ((pw = sgetpwnam("ftp")) != NULL) {
332 			guest = 1;
333 			askpasswd = 1;
334 			reply(331, "Guest login ok, send ident as password.");
335 		} else
336 			reply(530, "User %s unknown.", name);
337 		return;
338 	}
339 	if (pw = sgetpwnam(name)) {
340 		if ((shell = pw->pw_shell) == NULL || *shell == 0)
341 			shell = _PATH_BSHELL;
342 		while ((cp = getusershell()) != NULL)
343 			if (strcmp(cp, shell) == 0)
344 				break;
345 		endusershell();
346 		if (cp == NULL || checkuser(name)) {
347 			reply(530, "User %s access denied.", name);
348 			if (logging)
349 				syslog(LOG_NOTICE,
350 				    "FTP LOGIN REFUSED FROM %s, %s",
351 				    remotehost, name);
352 			pw = (struct passwd *) NULL;
353 			return;
354 		}
355 	}
356 	reply(331, "Password required for %s.", name);
357 	askpasswd = 1;
358 	/*
359 	 * Delay before reading passwd after first failed
360 	 * attempt to slow down passwd-guessing programs.
361 	 */
362 	if (login_attempts)
363 		sleep((unsigned) login_attempts);
364 }
365 
366 /*
367  * Check if a user is in the file _PATH_FTPUSERS
368  */
369 checkuser(name)
370 	char *name;
371 {
372 	register FILE *fd;
373 	register char *p;
374 	char line[BUFSIZ];
375 
376 	if ((fd = fopen(_PATH_FTPUSERS, "r")) != NULL) {
377 		while (fgets(line, sizeof(line), fd) != NULL)
378 			if ((p = index(line, '\n')) != NULL) {
379 				*p = '\0';
380 				if (line[0] == '#')
381 					continue;
382 				if (strcmp(line, name) == 0)
383 					return (1);
384 			}
385 		(void) fclose(fd);
386 	}
387 	return (0);
388 }
389 
390 /*
391  * Terminate login as previous user, if any, resetting state;
392  * used when USER command is given or login fails.
393  */
394 end_login()
395 {
396 
397 	(void) seteuid((uid_t)0);
398 	if (logged_in)
399 		logwtmp(ttyline, "", "");
400 	pw = NULL;
401 	logged_in = 0;
402 	guest = 0;
403 }
404 
405 pass(passwd)
406 	char *passwd;
407 {
408 	char *xpasswd, *salt;
409 
410 	if (logged_in || askpasswd == 0) {
411 		reply(503, "Login with USER first.");
412 		return;
413 	}
414 	askpasswd = 0;
415 	if (!guest) {		/* "ftp" is only account allowed no password */
416 		if (pw == NULL)
417 			salt = "xx";
418 		else
419 			salt = pw->pw_passwd;
420 		xpasswd = crypt(passwd, salt);
421 		/* The strcmp does not catch null passwords! */
422 		if (pw == NULL || *pw->pw_passwd == '\0' ||
423 		    strcmp(xpasswd, pw->pw_passwd)) {
424 			reply(530, "Login incorrect.");
425 			pw = NULL;
426 			if (login_attempts++ >= 5) {
427 				syslog(LOG_NOTICE,
428 				    "repeated login failures from %s",
429 				    remotehost);
430 				exit(0);
431 			}
432 			return;
433 		}
434 	}
435 	login_attempts = 0;		/* this time successful */
436 	(void) setegid((gid_t)pw->pw_gid);
437 	(void) initgroups(pw->pw_name, pw->pw_gid);
438 
439 	/* open wtmp before chroot */
440 	(void)sprintf(ttyline, "ftp%d", getpid());
441 	logwtmp(ttyline, pw->pw_name, remotehost);
442 	logged_in = 1;
443 
444 	if (guest) {
445 		/*
446 		 * We MUST do a chdir() after the chroot. Otherwise
447 		 * the old current directory will be accessible as "."
448 		 * outside the new root!
449 		 */
450 		if (chroot(pw->pw_dir) < 0 || chdir("/") < 0) {
451 			reply(550, "Can't set guest privileges.");
452 			goto bad;
453 		}
454 	} else if (chdir(pw->pw_dir) < 0) {
455 		if (chdir("/") < 0) {
456 			reply(530, "User %s: can't change directory to %s.",
457 			    pw->pw_name, pw->pw_dir);
458 			goto bad;
459 		} else
460 			lreply(230, "No directory! Logging in with home=/");
461 	}
462 	if (seteuid((uid_t)pw->pw_uid) < 0) {
463 		reply(550, "Can't set uid.");
464 		goto bad;
465 	}
466 	if (guest) {
467 		reply(230, "Guest login ok, access restrictions apply.");
468 #ifdef SETPROCTITLE
469 		sprintf(proctitle, "%s: anonymous/%.*s", remotehost,
470 		    sizeof(proctitle) - sizeof(remotehost) -
471 		    sizeof(": anonymous/"), passwd);
472 		setproctitle(proctitle);
473 #endif /* SETPROCTITLE */
474 		if (logging)
475 			syslog(LOG_INFO, "ANONYMOUS FTP LOGIN FROM %s, %s",
476 			    remotehost, passwd);
477 	} else {
478 		reply(230, "User %s logged in.", pw->pw_name);
479 #ifdef SETPROCTITLE
480 		sprintf(proctitle, "%s: %s", remotehost, pw->pw_name);
481 		setproctitle(proctitle);
482 #endif /* SETPROCTITLE */
483 		if (logging)
484 			syslog(LOG_INFO, "FTP LOGIN FROM %s, %s",
485 			    remotehost, pw->pw_name);
486 	}
487 	home = pw->pw_dir;		/* home dir for globbing */
488 	(void) umask(defumask);
489 	return;
490 bad:
491 	/* Forget all about it... */
492 	end_login();
493 }
494 
495 retrieve(cmd, name)
496 	char *cmd, *name;
497 {
498 	FILE *fin, *dout;
499 	struct stat st;
500 	int (*closefunc)();
501 
502 	if (cmd == 0) {
503 		fin = fopen(name, "r"), closefunc = fclose;
504 		st.st_size = 0;
505 	} else {
506 		char line[BUFSIZ];
507 
508 		(void) sprintf(line, cmd, name), name = line;
509 		fin = ftpd_popen(line, "r"), closefunc = ftpd_pclose;
510 		st.st_size = -1;
511 		st.st_blksize = BUFSIZ;
512 	}
513 	if (fin == NULL) {
514 		if (errno != 0)
515 			perror_reply(550, name);
516 		return;
517 	}
518 	if (cmd == 0 &&
519 	    (fstat(fileno(fin), &st) < 0 || (st.st_mode&S_IFMT) != S_IFREG)) {
520 		reply(550, "%s: not a plain file.", name);
521 		goto done;
522 	}
523 	if (restart_point) {
524 		if (type == TYPE_A) {
525 			register int i, n, c;
526 
527 			n = restart_point;
528 			i = 0;
529 			while (i++ < n) {
530 				if ((c=getc(fin)) == EOF) {
531 					perror_reply(550, name);
532 					goto done;
533 				}
534 				if (c == '\n')
535 					i++;
536 			}
537 		} else if (lseek(fileno(fin), restart_point, L_SET) < 0) {
538 			perror_reply(550, name);
539 			goto done;
540 		}
541 	}
542 	dout = dataconn(name, st.st_size, "w");
543 	if (dout == NULL)
544 		goto done;
545 	send_data(fin, dout, st.st_blksize);
546 	(void) fclose(dout);
547 	data = -1;
548 	pdata = -1;
549 done:
550 	(*closefunc)(fin);
551 }
552 
553 store(name, mode, unique)
554 	char *name, *mode;
555 	int unique;
556 {
557 	FILE *fout, *din;
558 	struct stat st;
559 	int (*closefunc)();
560 	char *gunique();
561 
562 	if (unique && stat(name, &st) == 0 &&
563 	    (name = gunique(name)) == NULL)
564 		return;
565 
566 	if (restart_point)
567 		mode = "r+w";
568 	fout = fopen(name, mode);
569 	closefunc = fclose;
570 	if (fout == NULL) {
571 		perror_reply(553, name);
572 		return;
573 	}
574 	if (restart_point) {
575 		if (type == TYPE_A) {
576 			register int i, n, c;
577 
578 			n = restart_point;
579 			i = 0;
580 			while (i++ < n) {
581 				if ((c=getc(fout)) == EOF) {
582 					perror_reply(550, name);
583 					goto done;
584 				}
585 				if (c == '\n')
586 					i++;
587 			}
588 			/*
589 			 * We must do this seek to "current" position
590 			 * because we are changing from reading to
591 			 * writing.
592 			 */
593 			if (fseek(fout, 0L, L_INCR) < 0) {
594 				perror_reply(550, name);
595 				goto done;
596 			}
597 		} else if (lseek(fileno(fout), restart_point, L_SET) < 0) {
598 			perror_reply(550, name);
599 			goto done;
600 		}
601 	}
602 	din = dataconn(name, (off_t)-1, "r");
603 	if (din == NULL)
604 		goto done;
605 	if (receive_data(din, fout) == 0) {
606 		if (unique)
607 			reply(226, "Transfer complete (unique file name:%s).",
608 			    name);
609 		else
610 			reply(226, "Transfer complete.");
611 	}
612 	(void) fclose(din);
613 	data = -1;
614 	pdata = -1;
615 done:
616 	(*closefunc)(fout);
617 }
618 
619 FILE *
620 getdatasock(mode)
621 	char *mode;
622 {
623 	int s, on = 1, tries;
624 
625 	if (data >= 0)
626 		return (fdopen(data, mode));
627 	s = socket(AF_INET, SOCK_STREAM, 0);
628 	if (s < 0)
629 		return (NULL);
630 	(void) seteuid((uid_t)0);
631 	if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
632 	    (char *) &on, sizeof (on)) < 0)
633 		goto bad;
634 	/* anchor socket to avoid multi-homing problems */
635 	data_source.sin_family = AF_INET;
636 	data_source.sin_addr = ctrl_addr.sin_addr;
637 	for (tries = 1; ; tries++) {
638 		if (bind(s, (struct sockaddr *)&data_source,
639 		    sizeof (data_source)) >= 0)
640 			break;
641 		if (errno != EADDRINUSE || tries > 10)
642 			goto bad;
643 		sleep(tries);
644 	}
645 	(void) seteuid((uid_t)pw->pw_uid);
646 #ifdef IP_TOS
647 	on = IPTOS_THROUGHPUT;
648 	if (setsockopt(s, IPPROTO_IP, IP_TOS, (char *)&on, sizeof(int)) < 0)
649 		syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
650 #endif
651 	return (fdopen(s, mode));
652 bad:
653 	(void) seteuid((uid_t)pw->pw_uid);
654 	(void) close(s);
655 	return (NULL);
656 }
657 
658 FILE *
659 dataconn(name, size, mode)
660 	char *name;
661 	off_t size;
662 	char *mode;
663 {
664 	char sizebuf[32];
665 	FILE *file;
666 	int retry = 0, tos;
667 
668 	file_size = size;
669 	byte_count = 0;
670 	if (size != (off_t) -1)
671 		(void) sprintf (sizebuf, " (%ld bytes)", size);
672 	else
673 		(void) strcpy(sizebuf, "");
674 	if (pdata >= 0) {
675 		struct sockaddr_in from;
676 		int s, fromlen = sizeof(from);
677 
678 		s = accept(pdata, (struct sockaddr *)&from, &fromlen);
679 		if (s < 0) {
680 			reply(425, "Can't open data connection.");
681 			(void) close(pdata);
682 			pdata = -1;
683 			return(NULL);
684 		}
685 		(void) close(pdata);
686 		pdata = s;
687 #ifdef IP_TOS
688 		tos = IPTOS_LOWDELAY;
689 		(void) setsockopt(s, IPPROTO_IP, IP_TOS, (char *)&tos,
690 		    sizeof(int));
691 #endif
692 		reply(150, "Opening %s mode data connection for %s%s.",
693 		     type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
694 		return(fdopen(pdata, mode));
695 	}
696 	if (data >= 0) {
697 		reply(125, "Using existing data connection for %s%s.",
698 		    name, sizebuf);
699 		usedefault = 1;
700 		return (fdopen(data, mode));
701 	}
702 	if (usedefault)
703 		data_dest = his_addr;
704 	usedefault = 1;
705 	file = getdatasock(mode);
706 	if (file == NULL) {
707 		reply(425, "Can't create data socket (%s,%d): %s.",
708 		    inet_ntoa(data_source.sin_addr),
709 		    ntohs(data_source.sin_port), strerror(errno));
710 		return (NULL);
711 	}
712 	data = fileno(file);
713 	while (connect(data, (struct sockaddr *)&data_dest,
714 	    sizeof (data_dest)) < 0) {
715 		if (errno == EADDRINUSE && retry < swaitmax) {
716 			sleep((unsigned) swaitint);
717 			retry += swaitint;
718 			continue;
719 		}
720 		perror_reply(425, "Can't build data connection");
721 		(void) fclose(file);
722 		data = -1;
723 		return (NULL);
724 	}
725 	reply(150, "Opening %s mode data connection for %s%s.",
726 	     type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
727 	return (file);
728 }
729 
730 /*
731  * Tranfer the contents of "instr" to
732  * "outstr" peer using the appropriate
733  * encapsulation of the data subject
734  * to Mode, Structure, and Type.
735  *
736  * NB: Form isn't handled.
737  */
738 send_data(instr, outstr, blksize)
739 	FILE *instr, *outstr;
740 	off_t blksize;
741 {
742 	register int c, cnt;
743 	register char *buf;
744 	int netfd, filefd;
745 
746 	transflag++;
747 	if (setjmp(urgcatch)) {
748 		transflag = 0;
749 		return;
750 	}
751 	switch (type) {
752 
753 	case TYPE_A:
754 		while ((c = getc(instr)) != EOF) {
755 			byte_count++;
756 			if (c == '\n') {
757 				if (ferror(outstr))
758 					goto data_err;
759 				(void) putc('\r', outstr);
760 			}
761 			(void) putc(c, outstr);
762 		}
763 		fflush(outstr);
764 		transflag = 0;
765 		if (ferror(instr))
766 			goto file_err;
767 		if (ferror(outstr))
768 			goto data_err;
769 		reply(226, "Transfer complete.");
770 		return;
771 
772 	case TYPE_I:
773 	case TYPE_L:
774 		if ((buf = malloc((u_int)blksize)) == NULL) {
775 			transflag = 0;
776 			perror_reply(451, "Local resource failure: malloc");
777 			return;
778 		}
779 		netfd = fileno(outstr);
780 		filefd = fileno(instr);
781 		while ((cnt = read(filefd, buf, (u_int)blksize)) > 0 &&
782 		    write(netfd, buf, cnt) == cnt)
783 			byte_count += cnt;
784 		transflag = 0;
785 		(void)free(buf);
786 		if (cnt != 0) {
787 			if (cnt < 0)
788 				goto file_err;
789 			goto data_err;
790 		}
791 		reply(226, "Transfer complete.");
792 		return;
793 	default:
794 		transflag = 0;
795 		reply(550, "Unimplemented TYPE %d in send_data", type);
796 		return;
797 	}
798 
799 data_err:
800 	transflag = 0;
801 	perror_reply(426, "Data connection");
802 	return;
803 
804 file_err:
805 	transflag = 0;
806 	perror_reply(551, "Error on input file");
807 }
808 
809 /*
810  * Transfer data from peer to
811  * "outstr" using the appropriate
812  * encapulation of the data subject
813  * to Mode, Structure, and Type.
814  *
815  * N.B.: Form isn't handled.
816  */
817 receive_data(instr, outstr)
818 	FILE *instr, *outstr;
819 {
820 	register int c;
821 	int cnt, bare_lfs = 0;
822 	char buf[BUFSIZ];
823 
824 	transflag++;
825 	if (setjmp(urgcatch)) {
826 		transflag = 0;
827 		return (-1);
828 	}
829 	switch (type) {
830 
831 	case TYPE_I:
832 	case TYPE_L:
833 		while ((cnt = read(fileno(instr), buf, sizeof buf)) > 0) {
834 			if (write(fileno(outstr), buf, cnt) != cnt)
835 				goto file_err;
836 			byte_count += cnt;
837 		}
838 		if (cnt < 0)
839 			goto data_err;
840 		transflag = 0;
841 		return (0);
842 
843 	case TYPE_E:
844 		reply(553, "TYPE E not implemented.");
845 		transflag = 0;
846 		return (-1);
847 
848 	case TYPE_A:
849 		while ((c = getc(instr)) != EOF) {
850 			byte_count++;
851 			if (c == '\n')
852 				bare_lfs++;
853 			while (c == '\r') {
854 				if (ferror(outstr))
855 					goto data_err;
856 				if ((c = getc(instr)) != '\n') {
857 					(void) putc ('\r', outstr);
858 					if (c == '\0' || c == EOF)
859 						goto contin2;
860 				}
861 			}
862 			(void) putc(c, outstr);
863 	contin2:	;
864 		}
865 		fflush(outstr);
866 		if (ferror(instr))
867 			goto data_err;
868 		if (ferror(outstr))
869 			goto file_err;
870 		transflag = 0;
871 		if (bare_lfs) {
872 			lreply(230, "WARNING! %d bare linefeeds received in ASCII mode", bare_lfs);
873 			printf("   File may not have transferred correctly.\r\n");
874 		}
875 		return (0);
876 	default:
877 		reply(550, "Unimplemented TYPE %d in receive_data", type);
878 		transflag = 0;
879 		return (-1);
880 	}
881 
882 data_err:
883 	transflag = 0;
884 	perror_reply(426, "Data Connection");
885 	return (-1);
886 
887 file_err:
888 	transflag = 0;
889 	perror_reply(452, "Error writing file");
890 	return (-1);
891 }
892 
893 statfilecmd(filename)
894 	char *filename;
895 {
896 	char line[BUFSIZ];
897 	FILE *fin;
898 	int c;
899 
900 	(void) sprintf(line, "/bin/ls -lgA %s", filename);
901 	fin = ftpd_popen(line, "r");
902 	lreply(211, "status of %s:", filename);
903 	while ((c = getc(fin)) != EOF) {
904 		if (c == '\n') {
905 			if (ferror(stdout)){
906 				perror_reply(421, "control connection");
907 				(void) ftpd_pclose(fin);
908 				dologout(1);
909 				/* NOTREACHED */
910 			}
911 			if (ferror(fin)) {
912 				perror_reply(551, filename);
913 				(void) ftpd_pclose(fin);
914 				return;
915 			}
916 			(void) putc('\r', stdout);
917 		}
918 		(void) putc(c, stdout);
919 	}
920 	(void) ftpd_pclose(fin);
921 	reply(211, "End of Status");
922 }
923 
924 statcmd()
925 {
926 	struct sockaddr_in *sin;
927 	u_char *a, *p;
928 
929 	lreply(211, "%s FTP server status:", hostname, version);
930 	printf("     %s\r\n", version);
931 	printf("     Connected to %s", remotehost);
932 	if (!isdigit(remotehost[0]))
933 		printf(" (%s)", inet_ntoa(his_addr.sin_addr));
934 	printf("\r\n");
935 	if (logged_in) {
936 		if (guest)
937 			printf("     Logged in anonymously\r\n");
938 		else
939 			printf("     Logged in as %s\r\n", pw->pw_name);
940 	} else if (askpasswd)
941 		printf("     Waiting for password\r\n");
942 	else
943 		printf("     Waiting for user name\r\n");
944 	printf("     TYPE: %s", typenames[type]);
945 	if (type == TYPE_A || type == TYPE_E)
946 		printf(", FORM: %s", formnames[form]);
947 	if (type == TYPE_L)
948 #if NBBY == 8
949 		printf(" %d", NBBY);
950 #else
951 		printf(" %d", bytesize);	/* need definition! */
952 #endif
953 	printf("; STRUcture: %s; transfer MODE: %s\r\n",
954 	    strunames[stru], modenames[mode]);
955 	if (data != -1)
956 		printf("     Data connection open\r\n");
957 	else if (pdata != -1) {
958 		printf("     in Passive mode");
959 		sin = &pasv_addr;
960 		goto printaddr;
961 	} else if (usedefault == 0) {
962 		printf("     PORT");
963 		sin = &data_dest;
964 printaddr:
965 		a = (u_char *) &sin->sin_addr;
966 		p = (u_char *) &sin->sin_port;
967 #define UC(b) (((int) b) & 0xff)
968 		printf(" (%d,%d,%d,%d,%d,%d)\r\n", UC(a[0]),
969 			UC(a[1]), UC(a[2]), UC(a[3]), UC(p[0]), UC(p[1]));
970 #undef UC
971 	} else
972 		printf("     No data connection\r\n");
973 	reply(211, "End of status");
974 }
975 
976 fatal(s)
977 	char *s;
978 {
979 	reply(451, "Error in server: %s\n", s);
980 	reply(221, "Closing connection due to server error.");
981 	dologout(0);
982 	/* NOTREACHED */
983 }
984 
985 /* VARARGS2 */
986 reply(n, fmt, p0, p1, p2, p3, p4, p5)
987 	int n;
988 	char *fmt;
989 {
990 	printf("%d ", n);
991 	printf(fmt, p0, p1, p2, p3, p4, p5);
992 	printf("\r\n");
993 	(void)fflush(stdout);
994 	if (debug) {
995 		syslog(LOG_DEBUG, "<--- %d ", n);
996 		syslog(LOG_DEBUG, fmt, p0, p1, p2, p3, p4, p5);
997 }
998 }
999 
1000 /* VARARGS2 */
1001 lreply(n, fmt, p0, p1, p2, p3, p4, p5)
1002 	int n;
1003 	char *fmt;
1004 {
1005 	printf("%d- ", n);
1006 	printf(fmt, p0, p1, p2, p3, p4, p5);
1007 	printf("\r\n");
1008 	(void)fflush(stdout);
1009 	if (debug) {
1010 		syslog(LOG_DEBUG, "<--- %d- ", n);
1011 		syslog(LOG_DEBUG, fmt, p0, p1, p2, p3, p4, p5);
1012 	}
1013 }
1014 
1015 ack(s)
1016 	char *s;
1017 {
1018 	reply(250, "%s command successful.", s);
1019 }
1020 
1021 nack(s)
1022 	char *s;
1023 {
1024 	reply(502, "%s command not implemented.", s);
1025 }
1026 
1027 /* ARGSUSED */
1028 yyerror(s)
1029 	char *s;
1030 {
1031 	char *cp;
1032 
1033 	if (cp = index(cbuf,'\n'))
1034 		*cp = '\0';
1035 	reply(500, "'%s': command not understood.", cbuf);
1036 }
1037 
1038 delete(name)
1039 	char *name;
1040 {
1041 	struct stat st;
1042 
1043 	if (stat(name, &st) < 0) {
1044 		perror_reply(550, name);
1045 		return;
1046 	}
1047 	if ((st.st_mode&S_IFMT) == S_IFDIR) {
1048 		if (rmdir(name) < 0) {
1049 			perror_reply(550, name);
1050 			return;
1051 		}
1052 		goto done;
1053 	}
1054 	if (unlink(name) < 0) {
1055 		perror_reply(550, name);
1056 		return;
1057 	}
1058 done:
1059 	ack("DELE");
1060 }
1061 
1062 cwd(path)
1063 	char *path;
1064 {
1065 	if (chdir(path) < 0)
1066 		perror_reply(550, path);
1067 	else
1068 		ack("CWD");
1069 }
1070 
1071 makedir(name)
1072 	char *name;
1073 {
1074 	if (mkdir(name, 0777) < 0)
1075 		perror_reply(550, name);
1076 	else
1077 		reply(257, "MKD command successful.");
1078 }
1079 
1080 removedir(name)
1081 	char *name;
1082 {
1083 	if (rmdir(name) < 0)
1084 		perror_reply(550, name);
1085 	else
1086 		ack("RMD");
1087 }
1088 
1089 pwd()
1090 {
1091 	char path[MAXPATHLEN + 1];
1092 	extern char *getwd();
1093 
1094 	if (getwd(path) == (char *)NULL)
1095 		reply(550, "%s.", path);
1096 	else
1097 		reply(257, "\"%s\" is current directory.", path);
1098 }
1099 
1100 char *
1101 renamefrom(name)
1102 	char *name;
1103 {
1104 	struct stat st;
1105 
1106 	if (stat(name, &st) < 0) {
1107 		perror_reply(550, name);
1108 		return ((char *)0);
1109 	}
1110 	reply(350, "File exists, ready for destination name");
1111 	return (name);
1112 }
1113 
1114 renamecmd(from, to)
1115 	char *from, *to;
1116 {
1117 	if (rename(from, to) < 0)
1118 		perror_reply(550, "rename");
1119 	else
1120 		ack("RNTO");
1121 }
1122 
1123 dolog(sin)
1124 	struct sockaddr_in *sin;
1125 {
1126 	struct hostent *hp = gethostbyaddr((char *)&sin->sin_addr,
1127 		sizeof (struct in_addr), AF_INET);
1128 	time_t t, time();
1129 	extern char *ctime();
1130 
1131 	if (hp)
1132 		(void) strncpy(remotehost, hp->h_name, sizeof (remotehost));
1133 	else
1134 		(void) strncpy(remotehost, inet_ntoa(sin->sin_addr),
1135 		    sizeof (remotehost));
1136 #ifdef SETPROCTITLE
1137 	sprintf(proctitle, "%s: connected", remotehost);
1138 	setproctitle(proctitle);
1139 #endif /* SETPROCTITLE */
1140 
1141 	if (logging) {
1142 		t = time((time_t *) 0);
1143 		syslog(LOG_INFO, "connection from %s at %s",
1144 		    remotehost, ctime(&t));
1145 	}
1146 }
1147 
1148 /*
1149  * Record logout in wtmp file
1150  * and exit with supplied status.
1151  */
1152 dologout(status)
1153 	int status;
1154 {
1155 	if (logged_in) {
1156 		(void) seteuid((uid_t)0);
1157 		logwtmp(ttyline, "", "");
1158 	}
1159 	/* beware of flushing buffers after a SIGPIPE */
1160 	_exit(status);
1161 }
1162 
1163 myoob()
1164 {
1165 	char *cp;
1166 
1167 	/* only process if transfer occurring */
1168 	if (!transflag)
1169 		return;
1170 	cp = tmpline;
1171 	if (getline(cp, 7, stdin) == NULL) {
1172 		reply(221, "You could at least say goodbye.");
1173 		dologout(0);
1174 	}
1175 	upper(cp);
1176 	if (strcmp(cp, "ABOR\r\n") == 0) {
1177 		tmpline[0] = '\0';
1178 		reply(426, "Transfer aborted. Data connection closed.");
1179 		reply(226, "Abort successful");
1180 		longjmp(urgcatch, 1);
1181 	}
1182 	if (strcmp(cp, "STAT\r\n") == 0) {
1183 		if (file_size != (off_t) -1)
1184 			reply(213, "Status: %lu of %lu bytes transferred",
1185 			    byte_count, file_size);
1186 		else
1187 			reply(213, "Status: %lu bytes transferred", byte_count);
1188 	}
1189 }
1190 
1191 /*
1192  * Note: a response of 425 is not mentioned as a possible response to
1193  * 	the PASV command in RFC959. However, it has been blessed as
1194  * 	a legitimate response by Jon Postel in a telephone conversation
1195  *	with Rick Adams on 25 Jan 89.
1196  */
1197 passive()
1198 {
1199 	int len;
1200 	register char *p, *a;
1201 
1202 	pdata = socket(AF_INET, SOCK_STREAM, 0);
1203 	if (pdata < 0) {
1204 		perror_reply(425, "Can't open passive connection");
1205 		return;
1206 	}
1207 	pasv_addr = ctrl_addr;
1208 	pasv_addr.sin_port = 0;
1209 	(void) seteuid((uid_t)0);
1210 	if (bind(pdata, (struct sockaddr *)&pasv_addr, sizeof(pasv_addr)) < 0) {
1211 		(void) seteuid((uid_t)pw->pw_uid);
1212 		goto pasv_error;
1213 	}
1214 	(void) seteuid((uid_t)pw->pw_uid);
1215 	len = sizeof(pasv_addr);
1216 	if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
1217 		goto pasv_error;
1218 	if (listen(pdata, 1) < 0)
1219 		goto pasv_error;
1220 	a = (char *) &pasv_addr.sin_addr;
1221 	p = (char *) &pasv_addr.sin_port;
1222 
1223 #define UC(b) (((int) b) & 0xff)
1224 
1225 	reply(227, "Entering Passive Mode (%d,%d,%d,%d,%d,%d)", UC(a[0]),
1226 		UC(a[1]), UC(a[2]), UC(a[3]), UC(p[0]), UC(p[1]));
1227 	return;
1228 
1229 pasv_error:
1230 	(void) close(pdata);
1231 	pdata = -1;
1232 	perror_reply(425, "Can't open passive connection");
1233 	return;
1234 }
1235 
1236 /*
1237  * Generate unique name for file with basename "local".
1238  * The file named "local" is already known to exist.
1239  * Generates failure reply on error.
1240  */
1241 char *
1242 gunique(local)
1243 	char *local;
1244 {
1245 	static char new[MAXPATHLEN];
1246 	struct stat st;
1247 	char *cp = rindex(local, '/');
1248 	int count = 0;
1249 
1250 	if (cp)
1251 		*cp = '\0';
1252 	if (stat(cp ? local : ".", &st) < 0) {
1253 		perror_reply(553, cp ? local : ".");
1254 		return((char *) 0);
1255 	}
1256 	if (cp)
1257 		*cp = '/';
1258 	(void) strcpy(new, local);
1259 	cp = new + strlen(new);
1260 	*cp++ = '.';
1261 	for (count = 1; count < 100; count++) {
1262 		(void) sprintf(cp, "%d", count);
1263 		if (stat(new, &st) < 0)
1264 			return(new);
1265 	}
1266 	reply(452, "Unique file name cannot be created.");
1267 	return((char *) 0);
1268 }
1269 
1270 /*
1271  * Format and send reply containing system error number.
1272  */
1273 perror_reply(code, string)
1274 	int code;
1275 	char *string;
1276 {
1277 	reply(code, "%s: %s.", string, strerror(errno));
1278 }
1279 
1280 static char *onefile[] = {
1281 	"",
1282 	0
1283 };
1284 
1285 send_file_list(whichfiles)
1286 	char *whichfiles;
1287 {
1288 	struct stat st;
1289 	DIR *dirp = NULL;
1290 	struct direct *dir;
1291 	FILE *dout = NULL;
1292 	register char **dirlist, *dirname;
1293 	int simple = 0;
1294 	char *strpbrk();
1295 
1296 	if (strpbrk(whichfiles, "~{[*?") != NULL) {
1297 		extern char **glob(), *globerr;
1298 
1299 		globerr = NULL;
1300 		dirlist = glob(whichfiles);
1301 		if (globerr != NULL) {
1302 			reply(550, globerr);
1303 			return;
1304 		} else if (dirlist == NULL) {
1305 			errno = ENOENT;
1306 			perror_reply(550, whichfiles);
1307 			return;
1308 		}
1309 	} else {
1310 		onefile[0] = whichfiles;
1311 		dirlist = onefile;
1312 		simple = 1;
1313 	}
1314 
1315 	if (setjmp(urgcatch)) {
1316 		transflag = 0;
1317 		return;
1318 	}
1319 	while (dirname = *dirlist++) {
1320 		if (stat(dirname, &st) < 0) {
1321 			/*
1322 			 * If user typed "ls -l", etc, and the client
1323 			 * used NLST, do what the user meant.
1324 			 */
1325 			if (dirname[0] == '-' && *dirlist == NULL &&
1326 			    transflag == 0) {
1327 				retrieve("/bin/ls %s", dirname);
1328 				return;
1329 			}
1330 			perror_reply(550, whichfiles);
1331 			if (dout != NULL) {
1332 				(void) fclose(dout);
1333 				transflag = 0;
1334 				data = -1;
1335 				pdata = -1;
1336 			}
1337 			return;
1338 		}
1339 
1340 		if ((st.st_mode&S_IFMT) == S_IFREG) {
1341 			if (dout == NULL) {
1342 				dout = dataconn("file list", (off_t)-1, "w");
1343 				if (dout == NULL)
1344 					return;
1345 				transflag++;
1346 			}
1347 			fprintf(dout, "%s%s\n", dirname,
1348 				type == TYPE_A ? "\r" : "");
1349 			byte_count += strlen(dirname) + 1;
1350 			continue;
1351 		} else if ((st.st_mode&S_IFMT) != S_IFDIR)
1352 			continue;
1353 
1354 		if ((dirp = opendir(dirname)) == NULL)
1355 			continue;
1356 
1357 		while ((dir = readdir(dirp)) != NULL) {
1358 			char nbuf[MAXPATHLEN];
1359 
1360 			if (dir->d_name[0] == '.' && dir->d_namlen == 1)
1361 				continue;
1362 			if (dir->d_name[0] == '.' && dir->d_name[1] == '.' &&
1363 			    dir->d_namlen == 2)
1364 				continue;
1365 
1366 			sprintf(nbuf, "%s/%s", dirname, dir->d_name);
1367 
1368 			/*
1369 			 * We have to do a stat to insure it's
1370 			 * not a directory or special file.
1371 			 */
1372 			if (simple || (stat(nbuf, &st) == 0 &&
1373 			    (st.st_mode&S_IFMT) == S_IFREG)) {
1374 				if (dout == NULL) {
1375 					dout = dataconn("file list", (off_t)-1,
1376 						"w");
1377 					if (dout == NULL)
1378 						return;
1379 					transflag++;
1380 				}
1381 				if (nbuf[0] == '.' && nbuf[1] == '/')
1382 					fprintf(dout, "%s%s\n", &nbuf[2],
1383 						type == TYPE_A ? "\r" : "");
1384 				else
1385 					fprintf(dout, "%s%s\n", nbuf,
1386 						type == TYPE_A ? "\r" : "");
1387 				byte_count += strlen(nbuf) + 1;
1388 			}
1389 		}
1390 		(void) closedir(dirp);
1391 	}
1392 
1393 	if (dout == NULL)
1394 		reply(550, "No files found.");
1395 	else if (ferror(dout) != 0)
1396 		perror_reply(550, "Data connection");
1397 	else
1398 		reply(226, "Transfer complete.");
1399 
1400 	transflag = 0;
1401 	if (dout != NULL)
1402 		(void) fclose(dout);
1403 	data = -1;
1404 	pdata = -1;
1405 }
1406 
1407 #ifdef SETPROCTITLE
1408 /*
1409  * clobber argv so ps will show what we're doing.
1410  * (stolen from sendmail)
1411  * warning, since this is usually started from inetd.conf, it
1412  * often doesn't have much of an environment or arglist to overwrite.
1413  */
1414 
1415 /*VARARGS1*/
1416 setproctitle(fmt, a, b, c)
1417 char *fmt;
1418 {
1419 	register char *p, *bp, ch;
1420 	register int i;
1421 	char buf[BUFSIZ];
1422 
1423 	(void) sprintf(buf, fmt, a, b, c);
1424 
1425 	/* make ps print our process name */
1426 	p = Argv[0];
1427 	*p++ = '-';
1428 
1429 	i = strlen(buf);
1430 	if (i > LastArgv - p - 2) {
1431 		i = LastArgv - p - 2;
1432 		buf[i] = '\0';
1433 	}
1434 	bp = buf;
1435 	while (ch = *bp++)
1436 		if (ch != '\n' && ch != '\r')
1437 			*p++ = ch;
1438 	while (p < LastArgv)
1439 		*p++ = ' ';
1440 }
1441 #endif /* SETPROCTITLE */
1442