xref: /netbsd-src/libexec/ftpd/cmds.c (revision 8d60259f074e7e2663207f24c47487b5fdf280fe)
1 /*	$NetBSD: cmds.c,v 1.35 2016/01/17 14:46:07 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1999-2009 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Luke Mewburn.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1985, 1988, 1990, 1992, 1993, 1994
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  */
60 
61 /*
62  * Copyright (C) 1997 and 1998 WIDE Project.
63  * All rights reserved.
64  *
65  * Redistribution and use in source and binary forms, with or without
66  * modification, are permitted provided that the following conditions
67  * are met:
68  * 1. Redistributions of source code must retain the above copyright
69  *    notice, this list of conditions and the following disclaimer.
70  * 2. Redistributions in binary form must reproduce the above copyright
71  *    notice, this list of conditions and the following disclaimer in the
72  *    documentation and/or other materials provided with the distribution.
73  * 3. Neither the name of the project nor the names of its contributors
74  *    may be used to endorse or promote products derived from this software
75  *    without specific prior written permission.
76  *
77  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
78  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
79  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
80  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
81  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
82  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
83  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
84  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
85  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
86  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
87  * SUCH DAMAGE.
88  */
89 
90 
91 #include <sys/cdefs.h>
92 #ifndef lint
93 __RCSID("$NetBSD: cmds.c,v 1.35 2016/01/17 14:46:07 christos Exp $");
94 #endif /* not lint */
95 
96 #include <sys/param.h>
97 #include <sys/stat.h>
98 
99 #include <arpa/ftp.h>
100 
101 #include <dirent.h>
102 #include <errno.h>
103 #include <stdio.h>
104 #include <stdlib.h>
105 #include <string.h>
106 #include <tzfile.h>
107 #include <unistd.h>
108 #include <ctype.h>
109 
110 #ifdef KERBEROS5
111 #include <krb5/krb5.h>
112 #endif
113 
114 #include "extern.h"
115 
116 typedef enum {
117 	FE_MLSD		= 1<<0,		/* if op is MLSD (MLST otherwise ) */
118 	FE_ISCURDIR	= 1<<1,		/* if name is the current directory */
119 } factflag_t;
120 
121 typedef struct {
122 	const char	*path;		/* full pathname */
123 	const char	*display;	/* name to display */
124 	struct stat	*stat;		/* stat of path */
125 	struct stat	*pdirstat;	/* stat of path's parent dir */
126 	factflag_t	 flags;		/* flags */
127 } factelem;
128 
129 static void	ack(const char *);
130 static void	base64_encode(const char *, size_t, char *, int);
131 static void	fact_type(const char *, FILE *, factelem *);
132 static void	fact_size(const char *, FILE *, factelem *);
133 static void	fact_modify(const char *, FILE *, factelem *);
134 static void	fact_perm(const char *, FILE *, factelem *);
135 static void	fact_unique(const char *, FILE *, factelem *);
136 static int	matchgroup(gid_t);
137 static void	mlsname(FILE *, factelem *);
138 static void	replydirname(const char *, const char *);
139 
140 struct ftpfact {
141 	const char	 *name;		/* name of fact */
142 	int		  enabled;	/* if fact is enabled */
143 	void		(*display)(const char *, FILE *, factelem *);
144 					/* function to display fact */
145 };
146 
147 struct ftpfact facttab[] = {
148 	{ "Type",	1, fact_type },
149 #define	FACT_TYPE 0
150 	{ "Size",	1, fact_size },
151 	{ "Modify",	1, fact_modify },
152 	{ "Perm",	1, fact_perm },
153 	{ "Unique",	1, fact_unique },
154 	/* "Create" */
155 	/* "Lang" */
156 	/* "Media-Type" */
157 	/* "CharSet" */
158 };
159 
160 #define FACTTABSIZE	(sizeof(facttab) / sizeof(struct ftpfact))
161 
162 static char cached_path[MAXPATHLEN + 1] = "/";
163 static void discover_path(char *, const char *);
164 
165 void
cwd(const char * path)166 cwd(const char *path)
167 {
168 
169 	if (chdir(path) < 0)
170 		perror_reply(550, path);
171 	else {
172 		show_chdir_messages(250);
173 		ack("CWD");
174 		if (getcwd(cached_path, MAXPATHLEN) == NULL) {
175 			discover_path(cached_path, path);
176 		}
177 	}
178 }
179 
180 void
delete(const char * name)181 delete(const char *name)
182 {
183 	char *p = NULL;
184 
185 	if (remove(name) < 0) {
186 		p = strerror(errno);
187 		perror_reply(550, name);
188 	} else
189 		ack("DELE");
190 	logxfer("delete", -1, name, NULL, NULL, p);
191 }
192 
193 void
feat(void)194 feat(void)
195 {
196 	size_t i;
197 
198 	reply(-211, "Features supported");
199 	cprintf(stdout, " MDTM\r\n");
200 	cprintf(stdout, " MLST ");
201 	for (i = 0; i < FACTTABSIZE; i++)
202 		cprintf(stdout, "%s%s;", facttab[i].name,
203 		    facttab[i].enabled ? "*" : "");
204 	cprintf(stdout, "\r\n");
205 	cprintf(stdout, " REST STREAM\r\n");
206 	cprintf(stdout, " SIZE\r\n");
207 	cprintf(stdout, " TVFS\r\n");
208 	reply(211,  "End");
209 }
210 
211 void
makedir(const char * name)212 makedir(const char *name)
213 {
214 	char *p = NULL;
215 
216 	if (mkdir(name, 0777) < 0) {
217 		p = strerror(errno);
218 		perror_reply(550, name);
219 	} else
220 		replydirname(name, "directory created.");
221 	logxfer("mkdir", -1, name, NULL, NULL, p);
222 }
223 
224 void
mlsd(const char * path)225 mlsd(const char *path)
226 {
227 	struct dirent	*dp;
228 	struct stat	 sb, pdirstat;
229 	factelem f;
230 	FILE	*dout;
231 	DIR	*dirp;
232 	char	name[MAXPATHLEN];
233 	int	hastypefact;
234 
235 	hastypefact = facttab[FACT_TYPE].enabled;
236 	if (path == NULL)
237 		path = ".";
238 	if (stat(path, &pdirstat) == -1) {
239  mlsdperror:
240 		perror_reply(550, path);
241 		return;
242 	}
243 	if (! S_ISDIR(pdirstat.st_mode)) {
244 		errno = ENOTDIR;
245 		perror_reply(501, path);
246 		return;
247 	}
248 	if ((dirp = opendir(path)) == NULL)
249 		goto mlsdperror;
250 
251 	dout = dataconn("MLSD", (off_t)-1, "w");
252 	if (dout == NULL) {
253 		(void) closedir(dirp);
254 		return;
255 	}
256 
257 	memset(&f, 0, sizeof(f));
258 	f.stat = &sb;
259 	f.flags |= FE_MLSD;
260 	while ((dp = readdir(dirp)) != NULL) {
261 		snprintf(name, sizeof(name), "%s/%s", path, dp->d_name);
262 		if (ISDOTDIR(dp->d_name)) {	/* special case curdir: */
263 			if (! hastypefact)
264 				continue;
265 			f.pdirstat = NULL;	/*   require stat of parent */
266 			f.display = path;	/*   set name to real name */
267 			f.flags |= FE_ISCURDIR; /*   flag name is curdir */
268 		} else {
269 			if (ISDOTDOTDIR(dp->d_name)) {
270 				if (! hastypefact)
271 					continue;
272 				f.pdirstat = NULL;
273 			} else
274 				f.pdirstat = &pdirstat;	/* cache parent stat */
275 			f.display = dp->d_name;
276 			f.flags &= ~FE_ISCURDIR;
277 		}
278 		if (stat(name, &sb) == -1)
279 			continue;
280 		f.path = name;
281 		mlsname(dout, &f);
282 	}
283 	(void)closedir(dirp);
284 
285 	if (ferror(dout) != 0)
286 		perror_reply(550, "Data connection");
287 	else
288 		reply(226, "MLSD complete.");
289 	closedataconn(dout);
290 	total_xfers_out++;
291 	total_xfers++;
292 }
293 
294 void
mlst(const char * path)295 mlst(const char *path)
296 {
297 	struct stat sb;
298 	factelem f;
299 
300 	if (path == NULL)
301 		path = ".";
302 	if (stat(path, &sb) == -1) {
303 		perror_reply(550, path);
304 		return;
305 	}
306 	reply(-250, "MLST %s", path);
307 	memset(&f, 0, sizeof(f));
308 	f.path = path;
309 	f.display = path;
310 	f.stat = &sb;
311 	f.pdirstat = NULL;
312 	CPUTC(' ', stdout);
313 	mlsname(stdout, &f);
314 	reply(250, "End");
315 }
316 
317 
318 void
opts(const char * command)319 opts(const char *command)
320 {
321 	struct tab *c;
322 	char *ep;
323 
324 	if ((ep = strchr(command, ' ')) != NULL)
325 		*ep++ = '\0';
326 	c = lookup(cmdtab, command);
327 	if (c == NULL) {
328 		reply(502, "Unknown command '%s'.", command);
329 		return;
330 	}
331 	if (! CMD_IMPLEMENTED(c)) {
332 		reply(502, "%s command not implemented.", c->name);
333 		return;
334 	}
335 	if (! CMD_HAS_OPTIONS(c)) {
336 		reply(501, "%s command does not support persistent options.",
337 		    c->name);
338 		return;
339 	}
340 
341 			/* special case: MLST */
342 	if (strcasecmp(command, "MLST") == 0) {
343 		int	 enabled[FACTTABSIZE];
344 		size_t	 i, onedone;
345 		size_t	 len;
346 		char	*p;
347 
348 		for (i = 0; i < sizeof(enabled) / sizeof(int); i++)
349 			enabled[i] = 0;
350 		if (ep == NULL || *ep == '\0')
351 			goto displaymlstopts;
352 
353 				/* don't like spaces, and need trailing ; */
354 		len = strlen(ep);
355 		if (strchr(ep, ' ') != NULL || ep[len - 1] != ';') {
356  badmlstopt:
357 			reply(501, "Invalid MLST options");
358 			return;
359 		}
360 		ep[len - 1] = '\0';
361 		while ((p = strsep(&ep, ";")) != NULL) {
362 			if (*p == '\0')
363 				goto badmlstopt;
364 			for (i = 0; i < FACTTABSIZE; i++)
365 				if (strcasecmp(p, facttab[i].name) == 0) {
366 					enabled[i] = 1;
367 					break;
368 				}
369 		}
370 
371  displaymlstopts:
372 		for (i = 0; i < FACTTABSIZE; i++)
373 			facttab[i].enabled = enabled[i];
374 		cprintf(stdout, "200 MLST OPTS");
375 		for (i = onedone = 0; i < FACTTABSIZE; i++) {
376 			if (facttab[i].enabled) {
377 				cprintf(stdout, "%s%s;", onedone ? "" : " ",
378 				    facttab[i].name);
379 				onedone++;
380 			}
381 		}
382 		cprintf(stdout, "\r\n");
383 		fflush(stdout);
384 		return;
385 	}
386 
387 			/* default cases */
388 	if (ep != NULL && *ep != '\0')
389 		REASSIGN(c->options, ftpd_strdup(ep));
390 	if (c->options != NULL)
391 		reply(200, "Options for %s are '%s'.", c->name,
392 		    c->options);
393 	else
394 		reply(200, "No options defined for %s.", c->name);
395 }
396 
397 void
pwd(void)398 pwd(void)
399 {
400 	char path[MAXPATHLEN];
401 
402 	if (getcwd(path, sizeof(path) - 1) == NULL) {
403 		if (chdir(cached_path) < 0) {
404 			reply(550, "Can't get the current directory: %s.",
405 			    strerror(errno));
406 			return;
407 		}
408 		(void)strlcpy(path, cached_path, MAXPATHLEN);
409 	}
410 	replydirname(path, "is the current directory.");
411 }
412 
413 void
removedir(const char * name)414 removedir(const char *name)
415 {
416 	char *p = NULL;
417 
418 	if (rmdir(name) < 0) {
419 		p = strerror(errno);
420 		perror_reply(550, name);
421 	} else
422 		ack("RMD");
423 	logxfer("rmdir", -1, name, NULL, NULL, p);
424 }
425 
426 char *
renamefrom(const char * name)427 renamefrom(const char *name)
428 {
429 	struct stat st;
430 
431 	if (stat(name, &st) < 0) {
432 		perror_reply(550, name);
433 		return (NULL);
434 	}
435 	reply(350, "File exists, ready for destination name");
436 	return (ftpd_strdup(name));
437 }
438 
439 void
renamecmd(const char * from,const char * to)440 renamecmd(const char *from, const char *to)
441 {
442 	char *p = NULL;
443 
444 	if (rename(from, to) < 0) {
445 		p = strerror(errno);
446 		perror_reply(550, "rename");
447 	} else
448 		ack("RNTO");
449 	logxfer("rename", -1, from, to, NULL, p);
450 }
451 
452 void
sizecmd(const char * filename)453 sizecmd(const char *filename)
454 {
455 	switch (type) {
456 	case TYPE_L:
457 	case TYPE_I:
458 	    {
459 		struct stat stbuf;
460 		if (stat(filename, &stbuf) < 0 || !S_ISREG(stbuf.st_mode))
461 			reply(550, "%s: not a plain file.", filename);
462 		else
463 			reply(213, ULLF, (ULLT)stbuf.st_size);
464 		break;
465 	    }
466 	case TYPE_A:
467 	    {
468 		FILE *fin;
469 		int c;
470 		off_t count;
471 		struct stat stbuf;
472 		fin = fopen(filename, "r");
473 		if (fin == NULL) {
474 			perror_reply(550, filename);
475 			return;
476 		}
477 		if (fstat(fileno(fin), &stbuf) < 0 || !S_ISREG(stbuf.st_mode)) {
478 			reply(550, "%s: not a plain file.", filename);
479 			(void) fclose(fin);
480 			return;
481 		}
482 		if (stbuf.st_size > 10240) {
483 			reply(550, "%s: file too large for SIZE.", filename);
484 			(void) fclose(fin);
485 			return;
486 		}
487 
488 		count = 0;
489 		while((c = getc(fin)) != EOF) {
490 			if (c == '\n')	/* will get expanded to \r\n */
491 				count++;
492 			count++;
493 		}
494 		(void) fclose(fin);
495 
496 		reply(213, LLF, (LLT)count);
497 		break;
498 	    }
499 	default:
500 		reply(504, "SIZE not implemented for Type %c.", "?AEIL"[type]);
501 	}
502 }
503 
504 void
statfilecmd(const char * filename)505 statfilecmd(const char *filename)
506 {
507 	FILE *fin;
508 	int c;
509 	int atstart;
510 	const char *argv[] = { INTERNAL_LS, "-lgA", "", NULL };
511 
512 	argv[2] = filename;
513 	fin = ftpd_popen(argv, "r", STDOUT_FILENO);
514 	reply(-211, "status of %s:", filename);
515 /* XXX: use fgetln() or fparseln() here? */
516 	atstart = 1;
517 	while ((c = getc(fin)) != EOF) {
518 		if (c == '\n') {
519 			if (ferror(stdout)){
520 				perror_reply(421, "control connection");
521 				(void) ftpd_pclose(fin);
522 				dologout(1);
523 				/* NOTREACHED */
524 			}
525 			if (ferror(fin)) {
526 				perror_reply(551, filename);
527 				(void) ftpd_pclose(fin);
528 				return;
529 			}
530 			CPUTC('\r', stdout);
531 		}
532 		if (atstart && isdigit(c))
533 			CPUTC(' ', stdout);
534 		CPUTC(c, stdout);
535 		atstart = (c == '\n');
536 	}
537 	(void) ftpd_pclose(fin);
538 	reply(211, "End of Status");
539 }
540 
541 /* -- */
542 
543 static void
ack(const char * s)544 ack(const char *s)
545 {
546 
547 	reply(250, "%s command successful.", s);
548 }
549 
550 /*
551  * Encode len bytes starting at clear using base64 encoding into encoded,
552  * which should be at least ((len + 2) * 4 / 3 + 1) in size.
553  * If nulterm is non-zero, terminate with \0 otherwise pad to 3 byte boundary
554  * with `='.
555  */
556 static void
base64_encode(const char * clear,size_t len,char * encoded,int nulterm)557 base64_encode(const char *clear, size_t len, char *encoded, int nulterm)
558 {
559 	static const char base64[] =
560 	    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
561 	const char *c;
562 	char	*e, termchar;
563 	int	 i;
564 
565 			/* determine whether to pad with '=' or NUL terminate */
566 	termchar = nulterm ? '\0' : '=';
567 	c = clear;
568 	e = encoded;
569 			/* convert all but last 2 bytes */
570 	for (i = len; i > 2; i -= 3, c += 3) {
571 		*e++ = base64[(c[0] >> 2) & 0x3f];
572 		*e++ = base64[((c[0] << 4) & 0x30) | ((c[1] >> 4) & 0x0f)];
573 		*e++ = base64[((c[1] << 2) & 0x3c) | ((c[2] >> 6) & 0x03)];
574 		*e++ = base64[(c[2]) & 0x3f];
575 	}
576 			/* handle slop at end */
577 	if (i > 0) {
578 		*e++ = base64[(c[0] >> 2) & 0x3f];
579 		*e++ = base64[((c[0] << 4) & 0x30) |
580 		     (i > 1 ? ((c[1] >> 4) & 0x0f) : 0)];
581 		*e++ = (i > 1) ? base64[(c[1] << 2) & 0x3c] : termchar;
582 		*e++ = termchar;
583 	}
584 	*e = '\0';
585 }
586 
587 static void
fact_modify(const char * fact,FILE * fd,factelem * fe)588 fact_modify(const char *fact, FILE *fd, factelem *fe)
589 {
590 	struct tm *t;
591 
592 	t = gmtime(&(fe->stat->st_mtime));
593 	cprintf(fd, "%s=%04d%02d%02d%02d%02d%02d;", fact,
594 	    TM_YEAR_BASE + t->tm_year,
595 	    t->tm_mon+1, t->tm_mday,
596 	    t->tm_hour, t->tm_min, t->tm_sec);
597 }
598 
599 static void
fact_perm(const char * fact,FILE * fd,factelem * fe)600 fact_perm(const char *fact, FILE *fd, factelem *fe)
601 {
602 	int		rok, wok, xok, pdirwok;
603 	struct stat	*pdir, dir;
604 
605 	if (fe->stat->st_uid == geteuid()) {
606 		rok = ((fe->stat->st_mode & S_IRUSR) != 0);
607 		wok = ((fe->stat->st_mode & S_IWUSR) != 0);
608 		xok = ((fe->stat->st_mode & S_IXUSR) != 0);
609 	} else if (matchgroup(fe->stat->st_gid)) {
610 		rok = ((fe->stat->st_mode & S_IRGRP) != 0);
611 		wok = ((fe->stat->st_mode & S_IWGRP) != 0);
612 		xok = ((fe->stat->st_mode & S_IXGRP) != 0);
613 	} else {
614 		rok = ((fe->stat->st_mode & S_IROTH) != 0);
615 		wok = ((fe->stat->st_mode & S_IWOTH) != 0);
616 		xok = ((fe->stat->st_mode & S_IXOTH) != 0);
617 	}
618 
619 	cprintf(fd, "%s=", fact);
620 
621 			/*
622 			 * if parent info not provided, look it up, but
623 			 * only if the current class has modify rights,
624 			 * since we only need this info in such a case.
625 			 */
626 	pdir = fe->pdirstat;
627 	if (pdir == NULL && CURCLASS_FLAGS_ISSET(modify)) {
628 		size_t		len;
629 		char		realdir[MAXPATHLEN], *p;
630 
631 		len = strlcpy(realdir, fe->path, sizeof(realdir));
632 		if (len < sizeof(realdir) - 4) {
633 			if (S_ISDIR(fe->stat->st_mode))
634 				strlcat(realdir, "/..", sizeof(realdir));
635 			else {
636 					/* if has a /, move back to it */
637 					/* otherwise use '..' */
638 				if ((p = strrchr(realdir, '/')) != NULL) {
639 					if (p == realdir)
640 						p++;
641 					*p = '\0';
642 				} else
643 					strlcpy(realdir, "..", sizeof(realdir));
644 			}
645 			if (stat(realdir, &dir) == 0)
646 				pdir = &dir;
647 		}
648 	}
649 	pdirwok = 0;
650 	if (pdir != NULL) {
651 		if (pdir->st_uid == geteuid())
652 			pdirwok = ((pdir->st_mode & S_IWUSR) != 0);
653 		else if (matchgroup(pdir->st_gid))
654 			pdirwok = ((pdir->st_mode & S_IWGRP) != 0);
655 		else
656 			pdirwok = ((pdir->st_mode & S_IWOTH) != 0);
657 	}
658 
659 			/* 'a': can APPE to file */
660 	if (wok && CURCLASS_FLAGS_ISSET(upload) && S_ISREG(fe->stat->st_mode))
661 		CPUTC('a', fd);
662 
663 			/* 'c': can create or append to files in directory */
664 	if (wok && CURCLASS_FLAGS_ISSET(modify) && S_ISDIR(fe->stat->st_mode))
665 		CPUTC('c', fd);
666 
667 			/* 'd': can delete file or directory */
668 	if (pdirwok && CURCLASS_FLAGS_ISSET(modify)) {
669 		int candel;
670 
671 		candel = 1;
672 		if (S_ISDIR(fe->stat->st_mode)) {
673 			DIR *dirp;
674 			struct dirent *dp;
675 
676 			if ((dirp = opendir(fe->display)) == NULL)
677 				candel = 0;
678 			else {
679 				while ((dp = readdir(dirp)) != NULL) {
680 					if (ISDOTDIR(dp->d_name) ||
681 					    ISDOTDOTDIR(dp->d_name))
682 						continue;
683 					candel = 0;
684 					break;
685 				}
686 				closedir(dirp);
687 			}
688 		}
689 		if (candel)
690 			CPUTC('d', fd);
691 	}
692 
693 			/* 'e': can enter directory */
694 	if (xok && S_ISDIR(fe->stat->st_mode))
695 		CPUTC('e', fd);
696 
697 			/* 'f': can rename file or directory */
698 	if (pdirwok && CURCLASS_FLAGS_ISSET(modify))
699 		CPUTC('f', fd);
700 
701 			/* 'l': can list directory */
702 	if (rok && xok && S_ISDIR(fe->stat->st_mode))
703 		CPUTC('l', fd);
704 
705 			/* 'm': can create directory */
706 	if (wok && CURCLASS_FLAGS_ISSET(modify) && S_ISDIR(fe->stat->st_mode))
707 		CPUTC('m', fd);
708 
709 			/* 'p': can remove files in directory */
710 	if (wok && CURCLASS_FLAGS_ISSET(modify) && S_ISDIR(fe->stat->st_mode))
711 		CPUTC('p', fd);
712 
713 			/* 'r': can RETR file */
714 	if (rok && S_ISREG(fe->stat->st_mode))
715 		CPUTC('r', fd);
716 
717 			/* 'w': can STOR file */
718 	if (wok && CURCLASS_FLAGS_ISSET(upload) && S_ISREG(fe->stat->st_mode))
719 		CPUTC('w', fd);
720 
721 	CPUTC(';', fd);
722 }
723 
724 static void
fact_size(const char * fact,FILE * fd,factelem * fe)725 fact_size(const char *fact, FILE *fd, factelem *fe)
726 {
727 
728 	if (S_ISREG(fe->stat->st_mode))
729 		cprintf(fd, "%s=" LLF ";", fact, (LLT)fe->stat->st_size);
730 }
731 
732 static void
fact_type(const char * fact,FILE * fd,factelem * fe)733 fact_type(const char *fact, FILE *fd, factelem *fe)
734 {
735 
736 	cprintf(fd, "%s=", fact);
737 	switch (fe->stat->st_mode & S_IFMT) {
738 	case S_IFDIR:
739 		if (fe->flags & FE_MLSD) {
740 			if ((fe->flags & FE_ISCURDIR) || ISDOTDIR(fe->display))
741 				cprintf(fd, "cdir");
742 			else if (ISDOTDOTDIR(fe->display))
743 				cprintf(fd, "pdir");
744 			else
745 				cprintf(fd, "dir");
746 		} else {
747 			cprintf(fd, "dir");
748 		}
749 		break;
750 	case S_IFREG:
751 		cprintf(fd, "file");
752 		break;
753 	case S_IFIFO:
754 		cprintf(fd, "OS.unix=fifo");
755 		break;
756 	case S_IFLNK:		/* XXX: probably a NO-OP with stat() */
757 		cprintf(fd, "OS.unix=slink");
758 		break;
759 	case S_IFSOCK:
760 		cprintf(fd, "OS.unix=socket");
761 		break;
762 	case S_IFBLK:
763 	case S_IFCHR:
764 		cprintf(fd, "OS.unix=%s-" ULLF "/" ULLF,
765 		    S_ISBLK(fe->stat->st_mode) ? "blk" : "chr",
766 		    (ULLT)major(fe->stat->st_rdev),
767 		    (ULLT)minor(fe->stat->st_rdev));
768 		break;
769 	default:
770 		cprintf(fd, "OS.unix=UNKNOWN(0%o)", fe->stat->st_mode & S_IFMT);
771 		break;
772 	}
773 	CPUTC(';', fd);
774 }
775 
776 static void
fact_unique(const char * fact,FILE * fd,factelem * fe)777 fact_unique(const char *fact, FILE *fd, factelem *fe)
778 {
779 	char obuf[(sizeof(dev_t) + sizeof(ino_t) + 2) * 4 / 3 + 2];
780 	char tbuf[sizeof(dev_t) + sizeof(ino_t)];
781 
782 	memcpy(tbuf,
783 	    (char *)&(fe->stat->st_dev), sizeof(dev_t));
784 	memcpy(tbuf + sizeof(dev_t),
785 	    (char *)&(fe->stat->st_ino), sizeof(ino_t));
786 	base64_encode(tbuf, sizeof(dev_t) + sizeof(ino_t), obuf, 1);
787 	cprintf(fd, "%s=%s;", fact, obuf);
788 }
789 
790 static int
matchgroup(gid_t gid)791 matchgroup(gid_t gid)
792 {
793 	int	i;
794 
795 	for (i = 0; i < gidcount; i++)
796 		if (gid == gidlist[i])
797 			return(1);
798 	return (0);
799 }
800 
801 static void
mlsname(FILE * fp,factelem * fe)802 mlsname(FILE *fp, factelem *fe)
803 {
804 	char realfile[MAXPATHLEN];
805 	int userf = 0;
806 	size_t i;
807 
808 	for (i = 0; i < FACTTABSIZE; i++) {
809 		if (facttab[i].enabled)
810 			(facttab[i].display)(facttab[i].name, fp, fe);
811 	}
812 	if ((fe->flags & FE_MLSD) &&
813 	    !(fe->flags & FE_ISCURDIR) && !ISDOTDIR(fe->display)) {
814 			/* if MLSD and not "." entry, display as-is */
815 		userf = 0;
816 	} else {
817 			/* if MLST, or MLSD and "." entry, realpath(3) it */
818 		if (realpath(fe->display, realfile) != NULL)
819 			userf = 1;
820 	}
821 	cprintf(fp, " %s\r\n", userf ? realfile : fe->display);
822 }
823 
824 static void
replydirname(const char * name,const char * message)825 replydirname(const char *name, const char *message)
826 {
827 	char *p, *ep;
828 	char npath[MAXPATHLEN * 2];
829 
830 	p = npath;
831 	ep = &npath[sizeof(npath) - 1];
832 	while (*name) {
833 		if (*name == '"') {
834 			if (ep - p < 2)
835 				break;
836 			*p++ = *name++;
837 			*p++ = '"';
838 		} else {
839 			if (ep - p < 1)
840 				break;
841 			*p++ = *name++;
842 		}
843 	}
844 	*p = '\0';
845 	reply(257, "\"%s\" %s", npath, message);
846 }
847 
848 static void
discover_path(char * last_path,const char * new_path)849 discover_path(char *last_path, const char *new_path)
850 {
851 	char tp[MAXPATHLEN + 1] = "";
852 	char tq[MAXPATHLEN + 1] = "";
853 	char *cp;
854 	char *cq;
855 	int sz1, sz2;
856 	int nomorelink;
857 	struct stat st1, st2;
858 
859 	if (new_path[0] != '/') {
860 		(void)strlcpy(tp, last_path, MAXPATHLEN);
861 		(void)strlcat(tp, "/", MAXPATHLEN);
862 	}
863 	(void)strlcat(tp, new_path, MAXPATHLEN);
864 	(void)strlcat(tp, "/", MAXPATHLEN);
865 
866 	/*
867 	 * resolve symlinks. A symlink may introduce another symlink, so we
868 	 * loop trying to resolve symlinks until we don't find any of them.
869 	 */
870 	do {
871 		/* Collapse any // into / */
872 		while ((cp = strstr(tp, "//")) != NULL)
873 			(void)memmove(cp, cp + 1, strlen(cp) - 1 + 1);
874 
875 		/* Collapse any /./ into / */
876 		while ((cp = strstr(tp, "/./")) != NULL)
877 			(void)memmove(cp, cp + 2, strlen(cp) - 2 + 1);
878 
879 		cp = tp;
880 		nomorelink = 1;
881 
882 		while ((cp = strstr(cp + 1, "/")) != NULL) {
883 			sz1 = (unsigned long)cp - (unsigned long)tp;
884 			if (sz1 > MAXPATHLEN)
885 				goto bad;
886 			*cp = 0;
887 			sz2 = readlink(tp, tq, MAXPATHLEN);
888 			*cp = '/';
889 
890 			/* If this is not a symlink, move to next / */
891 			if (sz2 <= 0)
892 				continue;
893 
894 			/*
895 			 * We found a symlink, so we will have to
896 			 * do one more pass to check there is no
897 			 * more symlink in the path
898 			 */
899 			nomorelink = 0;
900 
901 			/*
902 			 * Null terminate the string and remove trailing /
903 			 */
904 			tq[sz2] = 0;
905 			sz2 = strlen(tq);
906 			if (tq[sz2 - 1] == '/')
907 				tq[--sz2] = 0;
908 
909 			/*
910 			 * Is this an absolute link or a relative link?
911 			 */
912 			if (tq[0] == '/') {
913 				/* absolute link */
914 				if (strlen(cp) + sz2 > MAXPATHLEN)
915 					goto bad;
916 				memmove(tp + sz2, cp, strlen(cp) + 1);
917 				memcpy(tp, tq, sz2);
918 			} else {
919 				/* relative link */
920 				for (cq = cp - 1; *cq != '/'; cq--);
921 				if (strlen(tp) -
922 				    ((unsigned long)cq - (unsigned long)cp)
923 				    + 1 + sz2 > MAXPATHLEN)
924 					goto bad;
925 				(void)memmove(cq + 1 + sz2,
926 				    cp, strlen(cp) + 1);
927 				(void)memcpy(cq + 1, tq, sz2);
928 			}
929 
930 			/*
931 			 * start over, looking for new symlinks
932 			 */
933 			break;
934 		}
935 	} while (nomorelink == 0);
936 
937 	/* Collapse any /foo/../ into /foo/ */
938 	while ((cp = strstr(tp, "/../")) != NULL) {
939 		/* ^/../foo/ becomes ^/foo/ */
940 		if (cp == tp) {
941 			(void)memmove(cp, cp + 3,
942 			    strlen(cp) - 3 + 1);
943 		} else {
944 			for (cq = cp - 1; *cq != '/'; cq--);
945 			(void)memmove(cq, cp + 3,
946 			    strlen(cp) - 3 + 1);
947 		}
948 	}
949 
950 	/* strip strailing / */
951 	if (strlen(tp) != 1)
952 		tp[strlen(tp) - 1] = '\0';
953 
954 	/* check that the path is correct */
955 	if (stat(tp, &st1) == -1 || stat(".", &st2) == -1)
956 		goto bad;
957 	if ((st1.st_dev != st2.st_dev) || (st1.st_ino != st2.st_ino))
958 		goto bad;
959 
960 	(void)strlcpy(last_path, tp, MAXPATHLEN);
961 	return;
962 
963 bad:
964 	(void)strlcat(last_path, "/", MAXPATHLEN);
965 	(void)strlcat(last_path, new_path, MAXPATHLEN);
966 	return;
967 }
968 
969