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conf.c revision 1.63
      1 /*	$NetBSD: conf.c,v 1.63 2011/08/14 11:46:28 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1997-2009 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Simon Burge and 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 #include <sys/cdefs.h>
     33 #ifndef lint
     34 __RCSID("$NetBSD: conf.c,v 1.63 2011/08/14 11:46:28 christos Exp $");
     35 #endif /* not lint */
     36 
     37 #include <sys/types.h>
     38 #include <sys/param.h>
     39 #include <sys/socket.h>
     40 #include <sys/stat.h>
     41 
     42 #include <ctype.h>
     43 #include <errno.h>
     44 #include <fcntl.h>
     45 #include <glob.h>
     46 #include <netdb.h>
     47 #include <signal.h>
     48 #include <stdio.h>
     49 #include <stdlib.h>
     50 #include <string.h>
     51 #include <stringlist.h>
     52 #include <syslog.h>
     53 #include <time.h>
     54 #include <unistd.h>
     55 #include <util.h>
     56 
     57 #ifdef KERBEROS5
     58 #include <krb5/krb5.h>
     59 #endif
     60 
     61 #include "extern.h"
     62 #include "pathnames.h"
     63 
     64 static char *strend(const char *, char *);
     65 static int filetypematch(char *, int);
     66 
     67 
     68 		/* class defaults */
     69 #define DEFAULT_LIMIT		-1		/* unlimited connections */
     70 #define DEFAULT_MAXFILESIZE	-1		/* unlimited file size */
     71 #define DEFAULT_MAXTIMEOUT	7200		/* 2 hours */
     72 #define DEFAULT_TIMEOUT		900		/* 15 minutes */
     73 #define DEFAULT_UMASK		027		/* rw-r----- */
     74 
     75 /*
     76  * Initialise curclass to an `empty' state
     77  */
     78 void
     79 init_curclass(void)
     80 {
     81 	struct ftpconv	*conv, *cnext;
     82 
     83 	for (conv = curclass.conversions; conv != NULL; conv = cnext) {
     84 		REASSIGN(conv->suffix, NULL);
     85 		REASSIGN(conv->types, NULL);
     86 		REASSIGN(conv->disable, NULL);
     87 		REASSIGN(conv->command, NULL);
     88 		cnext = conv->next;
     89 		free(conv);
     90 	}
     91 
     92 	memset((char *)&curclass.advertise, 0, sizeof(curclass.advertise));
     93 	curclass.advertise.su_len = 0;		/* `not used' */
     94 	REASSIGN(curclass.chroot, NULL);
     95 	REASSIGN(curclass.classname, NULL);
     96 	curclass.conversions =	NULL;
     97 	REASSIGN(curclass.display, NULL);
     98 	REASSIGN(curclass.homedir, NULL);
     99 	curclass.limit =	DEFAULT_LIMIT;
    100 	REASSIGN(curclass.limitfile, NULL);
    101 	curclass.maxfilesize =	DEFAULT_MAXFILESIZE;
    102 	curclass.maxrateget =	0;
    103 	curclass.maxrateput =	0;
    104 	curclass.maxtimeout =	DEFAULT_MAXTIMEOUT;
    105 	REASSIGN(curclass.motd, ftpd_strdup(_NAME_FTPLOGINMESG));
    106 	REASSIGN(curclass.notify, NULL);
    107 	curclass.portmin =	0;
    108 	curclass.portmax =	0;
    109 	curclass.rateget =	0;
    110 	curclass.rateput =	0;
    111 	curclass.timeout =	DEFAULT_TIMEOUT;
    112 	    /* curclass.type is set elsewhere */
    113 	curclass.umask =	DEFAULT_UMASK;
    114 	curclass.mmapsize =	0;
    115 	curclass.readsize =	0;
    116 	curclass.writesize =	0;
    117 	curclass.sendbufsize =	0;
    118 	curclass.sendlowat =	0;
    119 
    120 	CURCLASS_FLAGS_SET(checkportcmd);
    121 	CURCLASS_FLAGS_CLR(denyquick);
    122 	CURCLASS_FLAGS_CLR(hidesymlinks);
    123 	CURCLASS_FLAGS_SET(modify);
    124 	CURCLASS_FLAGS_SET(passive);
    125 	CURCLASS_FLAGS_CLR(private);
    126 	CURCLASS_FLAGS_CLR(sanenames);
    127 	CURCLASS_FLAGS_SET(upload);
    128 }
    129 
    130 /*
    131  * Parse the configuration file, looking for the named class, and
    132  * define curclass to contain the appropriate settings.
    133  */
    134 void
    135 parse_conf(const char *findclass)
    136 {
    137 	FILE		*f;
    138 	char		*buf, *p;
    139 	size_t		 len;
    140 	LLT		 llval;
    141 	int		 none, match;
    142 	char		*endp, errbuf[100];
    143 	char		*class, *word, *arg, *template;
    144 	const char	*infile;
    145 	size_t		 line;
    146 	struct ftpconv	*conv, *cnext;
    147 
    148 	init_curclass();
    149 	REASSIGN(curclass.classname, ftpd_strdup(findclass));
    150 			/* set more guest defaults */
    151 	if (strcasecmp(findclass, "guest") == 0) {
    152 		CURCLASS_FLAGS_CLR(modify);
    153 		curclass.umask = 0707;
    154 	}
    155 
    156 	infile = conffilename(_NAME_FTPDCONF);
    157 	if ((f = fopen(infile, "r")) == NULL)
    158 		return;
    159 
    160 	line = 0;
    161 	template = NULL;
    162 	for (;
    163 	    (buf = fparseln(f, &len, &line, NULL, FPARSELN_UNESCCOMM |
    164 			    FPARSELN_UNESCCONT | FPARSELN_UNESCESC)) != NULL;
    165 	    free(buf)) {
    166 		none = match = 0;
    167 		p = buf;
    168 		if (len < 1)
    169 			continue;
    170 		if (p[len - 1] == '\n')
    171 			p[--len] = '\0';
    172 		if (EMPTYSTR(p))
    173 			continue;
    174 
    175 		NEXTWORD(p, word);
    176 		NEXTWORD(p, class);
    177 		NEXTWORD(p, arg);
    178 		if (EMPTYSTR(word) || EMPTYSTR(class))
    179 			continue;
    180 		if (strcasecmp(class, "none") == 0)
    181 			none = 1;
    182 		if (! (strcasecmp(class, findclass) == 0 ||
    183 		       (template != NULL && strcasecmp(class, template) == 0) ||
    184 		       none ||
    185 		       strcasecmp(class, "all") == 0) )
    186 			continue;
    187 
    188 #define CONF_FLAG(Field)						\
    189 	do {								\
    190 		if (none ||						\
    191 		    (!EMPTYSTR(arg) && strcasecmp(arg, "off") == 0))	\
    192 			CURCLASS_FLAGS_CLR(Field);			\
    193 		else							\
    194 			CURCLASS_FLAGS_SET(Field);			\
    195 	} while (0)
    196 
    197 #define CONF_STRING(Field)						\
    198 	do {								\
    199 		if (none || EMPTYSTR(arg))				\
    200 			arg = NULL;					\
    201 		else							\
    202 			arg = ftpd_strdup(arg);				\
    203 		REASSIGN(curclass.Field, arg);				\
    204 	} while (0)
    205 
    206 #define CONF_LL(Field,Arg,Min,Max)					\
    207 	do {								\
    208 		if (none || EMPTYSTR(Arg))				\
    209 			goto nextline;					\
    210 		llval = strsuftollx(#Field, Arg, Min, Max,		\
    211 		    errbuf, sizeof(errbuf));				\
    212 		if (errbuf[0]) {					\
    213 			syslog(LOG_WARNING, "%s line %d: %s",		\
    214 			    infile, (int)line, errbuf);			\
    215 			goto nextline;					\
    216 		}							\
    217 		curclass.Field = llval;					\
    218 	} while(0)
    219 
    220 		if (0)  {
    221 			/* no-op */
    222 
    223 		} else if ((strcasecmp(word, "advertise") == 0)
    224 			|| (strcasecmp(word, "advertize") == 0)) {
    225 			struct addrinfo	hints, *res;
    226 			int		error;
    227 
    228 			memset((char *)&curclass.advertise, 0,
    229 			    sizeof(curclass.advertise));
    230 			curclass.advertise.su_len = 0;
    231 			if (none || EMPTYSTR(arg))
    232 				continue;
    233 			res = NULL;
    234 			memset(&hints, 0, sizeof(hints));
    235 					/*
    236 					 * only get addresses of the family
    237 					 * that we're listening on
    238 					 */
    239 			hints.ai_family = ctrl_addr.su_family;
    240 			hints.ai_socktype = SOCK_STREAM;
    241 			error = getaddrinfo(arg, "0", &hints, &res);
    242 			if (error) {
    243 				syslog(LOG_WARNING, "%s line %d: %s",
    244 				    infile, (int)line, gai_strerror(error));
    245  advertiseparsefail:
    246 				if (res)
    247 					freeaddrinfo(res);
    248 				continue;
    249 			}
    250 			if (res->ai_next) {
    251 				syslog(LOG_WARNING,
    252     "%s line %d: multiple addresses returned for `%s'; please be more specific",
    253 				    infile, (int)line, arg);
    254 				goto advertiseparsefail;
    255 			}
    256 			if (sizeof(curclass.advertise) < res->ai_addrlen || (
    257 #ifdef INET6
    258 			    res->ai_family != AF_INET6 &&
    259 #endif
    260 			    res->ai_family != AF_INET)) {
    261 				syslog(LOG_WARNING,
    262     "%s line %d: unsupported protocol %d for `%s'",
    263 				    infile, (int)line, res->ai_family, arg);
    264 				goto advertiseparsefail;
    265 			}
    266 			memcpy(&curclass.advertise, res->ai_addr,
    267 			    res->ai_addrlen);
    268 			curclass.advertise.su_len = res->ai_addrlen;
    269 			freeaddrinfo(res);
    270 
    271 		} else if (strcasecmp(word, "checkportcmd") == 0) {
    272 			CONF_FLAG(checkportcmd);
    273 
    274 		} else if (strcasecmp(word, "chroot") == 0) {
    275 			CONF_STRING(chroot);
    276 
    277 		} else if (strcasecmp(word, "classtype") == 0) {
    278 			if (!none && !EMPTYSTR(arg)) {
    279 				if (strcasecmp(arg, "GUEST") == 0)
    280 					curclass.type = CLASS_GUEST;
    281 				else if (strcasecmp(arg, "CHROOT") == 0)
    282 					curclass.type = CLASS_CHROOT;
    283 				else if (strcasecmp(arg, "REAL") == 0)
    284 					curclass.type = CLASS_REAL;
    285 				else {
    286 					syslog(LOG_WARNING,
    287 				    "%s line %d: unknown class type `%s'",
    288 					    infile, (int)line, arg);
    289 					continue;
    290 				}
    291 			}
    292 
    293 		} else if (strcasecmp(word, "conversion") == 0) {
    294 			char *suffix, *types, *disable, *convcmd;
    295 
    296 			if (EMPTYSTR(arg)) {
    297 				syslog(LOG_WARNING,
    298 				    "%s line %d: %s requires a suffix",
    299 				    infile, (int)line, word);
    300 				continue;	/* need a suffix */
    301 			}
    302 			NEXTWORD(p, types);
    303 			NEXTWORD(p, disable);
    304 			convcmd = p;
    305 			if (convcmd)
    306 				convcmd += strspn(convcmd, " \t");
    307 			suffix = ftpd_strdup(arg);
    308 			if (none || EMPTYSTR(types) ||
    309 			    EMPTYSTR(disable) || EMPTYSTR(convcmd)) {
    310 				types = NULL;
    311 				disable = NULL;
    312 				convcmd = NULL;
    313 			} else {
    314 				types = ftpd_strdup(types);
    315 				disable = ftpd_strdup(disable);
    316 				convcmd = ftpd_strdup(convcmd);
    317 			}
    318 			for (conv = curclass.conversions; conv != NULL;
    319 			    conv = conv->next) {
    320 				if (strcmp(conv->suffix, suffix) == 0)
    321 					break;
    322 			}
    323 			if (conv == NULL) {
    324 				conv = (struct ftpconv *)
    325 				    calloc(1, sizeof(struct ftpconv));
    326 				if (conv == NULL) {
    327 					syslog(LOG_WARNING, "can't malloc");
    328 					continue;
    329 				}
    330 				conv->next = NULL;
    331 				for (cnext = curclass.conversions;
    332 				    cnext != NULL; cnext = cnext->next)
    333 					if (cnext->next == NULL)
    334 						break;
    335 				if (cnext != NULL)
    336 					cnext->next = conv;
    337 				else
    338 					curclass.conversions = conv;
    339 			}
    340 			REASSIGN(conv->suffix, suffix);
    341 			REASSIGN(conv->types, types);
    342 			REASSIGN(conv->disable, disable);
    343 			REASSIGN(conv->command, convcmd);
    344 
    345 		} else if (strcasecmp(word, "denyquick") == 0) {
    346 			CONF_FLAG(denyquick);
    347 
    348 		} else if (strcasecmp(word, "display") == 0) {
    349 			CONF_STRING(display);
    350 
    351 		} else if (strcasecmp(word, "hidesymlinks") == 0) {
    352 			CONF_FLAG(hidesymlinks);
    353 
    354 		} else if (strcasecmp(word, "homedir") == 0) {
    355 			CONF_STRING(homedir);
    356 
    357 		} else if (strcasecmp(word, "limit") == 0) {
    358 			curclass.limit = DEFAULT_LIMIT;
    359 			REASSIGN(curclass.limitfile, NULL);
    360 			CONF_LL(limit, arg, -1, LLTMAX);
    361 			REASSIGN(curclass.limitfile,
    362 			    EMPTYSTR(p) ? NULL : ftpd_strdup(p));
    363 
    364 		} else if (strcasecmp(word, "maxfilesize") == 0) {
    365 			curclass.maxfilesize = DEFAULT_MAXFILESIZE;
    366 			CONF_LL(maxfilesize, arg, -1, LLTMAX);
    367 
    368 		} else if (strcasecmp(word, "maxtimeout") == 0) {
    369 			curclass.maxtimeout = DEFAULT_MAXTIMEOUT;
    370 			CONF_LL(maxtimeout, arg,
    371 			    MIN(30, curclass.timeout), LLTMAX);
    372 
    373 		} else if (strcasecmp(word, "mmapsize") == 0) {
    374 			curclass.mmapsize = 0;
    375 			CONF_LL(mmapsize, arg, 0, SSIZE_MAX);
    376 
    377 		} else if (strcasecmp(word, "readsize") == 0) {
    378 			curclass.readsize = 0;
    379 			CONF_LL(readsize, arg, 0, SSIZE_MAX);
    380 
    381 		} else if (strcasecmp(word, "writesize") == 0) {
    382 			curclass.writesize = 0;
    383 			CONF_LL(writesize, arg, 0, SSIZE_MAX);
    384 
    385 		} else if (strcasecmp(word, "recvbufsize") == 0) {
    386 			curclass.recvbufsize = 0;
    387 			CONF_LL(recvbufsize, arg, 0, INT_MAX);
    388 
    389 		} else if (strcasecmp(word, "sendbufsize") == 0) {
    390 			curclass.sendbufsize = 0;
    391 			CONF_LL(sendbufsize, arg, 0, INT_MAX);
    392 
    393 		} else if (strcasecmp(word, "sendlowat") == 0) {
    394 			curclass.sendlowat = 0;
    395 			CONF_LL(sendlowat, arg, 0, INT_MAX);
    396 
    397 		} else if (strcasecmp(word, "modify") == 0) {
    398 			CONF_FLAG(modify);
    399 
    400 		} else if (strcasecmp(word, "motd") == 0) {
    401 			CONF_STRING(motd);
    402 
    403 		} else if (strcasecmp(word, "notify") == 0) {
    404 			CONF_STRING(notify);
    405 
    406 		} else if (strcasecmp(word, "passive") == 0) {
    407 			CONF_FLAG(passive);
    408 
    409 		} else if (strcasecmp(word, "portrange") == 0) {
    410 			long minport, maxport;
    411 
    412 			curclass.portmin = 0;
    413 			curclass.portmax = 0;
    414 			if (none || EMPTYSTR(arg))
    415 				continue;
    416 			if (EMPTYSTR(p)) {
    417 				syslog(LOG_WARNING,
    418 				   "%s line %d: missing maxport argument",
    419 				   infile, (int)line);
    420 				continue;
    421 			}
    422 			minport = strsuftollx("minport", arg, IPPORT_RESERVED,
    423 			    IPPORT_ANONMAX, errbuf, sizeof(errbuf));
    424 			if (errbuf[0]) {
    425 				syslog(LOG_WARNING, "%s line %d: %s",
    426 				    infile, (int)line, errbuf);
    427 				continue;
    428 			}
    429 			maxport = strsuftollx("maxport", p, IPPORT_RESERVED,
    430 			    IPPORT_ANONMAX, errbuf, sizeof(errbuf));
    431 			if (errbuf[0]) {
    432 				syslog(LOG_WARNING, "%s line %d: %s",
    433 				    infile, (int)line, errbuf);
    434 				continue;
    435 			}
    436 			if (minport >= maxport) {
    437 				syslog(LOG_WARNING,
    438 				    "%s line %d: minport %ld >= maxport %ld",
    439 				    infile, (int)line, minport, maxport);
    440 				continue;
    441 			}
    442 			curclass.portmin = (int)minport;
    443 			curclass.portmax = (int)maxport;
    444 
    445 		} else if (strcasecmp(word, "private") == 0) {
    446 			CONF_FLAG(private);
    447 
    448 		} else if (strcasecmp(word, "rateget") == 0) {
    449 			curclass.maxrateget = curclass.rateget = 0;
    450 			CONF_LL(rateget, arg, 0, LLTMAX);
    451 			curclass.maxrateget = curclass.rateget;
    452 
    453 		} else if (strcasecmp(word, "rateput") == 0) {
    454 			curclass.maxrateput = curclass.rateput = 0;
    455 			CONF_LL(rateput, arg, 0, LLTMAX);
    456 			curclass.maxrateput = curclass.rateput;
    457 
    458 		} else if (strcasecmp(word, "sanenames") == 0) {
    459 			CONF_FLAG(sanenames);
    460 
    461 		} else if (strcasecmp(word, "timeout") == 0) {
    462 			curclass.timeout = DEFAULT_TIMEOUT;
    463 			CONF_LL(timeout, arg, 30, curclass.maxtimeout);
    464 
    465 		} else if (strcasecmp(word, "template") == 0) {
    466 			if (none)
    467 				continue;
    468 			REASSIGN(template, EMPTYSTR(arg) ? NULL : ftpd_strdup(arg));
    469 
    470 		} else if (strcasecmp(word, "umask") == 0) {
    471 			unsigned long fumask;
    472 
    473 			curclass.umask = DEFAULT_UMASK;
    474 			if (none || EMPTYSTR(arg))
    475 				continue;
    476 			errno = 0;
    477 			endp = NULL;
    478 			fumask = strtoul(arg, &endp, 8);
    479 			if (errno || *arg == '\0' || *endp != '\0' ||
    480 			    fumask > 0777) {
    481 				syslog(LOG_WARNING,
    482 				    "%s line %d: invalid umask %s",
    483 				    infile, (int)line, arg);
    484 				continue;
    485 			}
    486 			curclass.umask = (mode_t)fumask;
    487 
    488 		} else if (strcasecmp(word, "upload") == 0) {
    489 			CONF_FLAG(upload);
    490 			if (! CURCLASS_FLAGS_ISSET(upload))
    491 				CURCLASS_FLAGS_CLR(modify);
    492 
    493 		} else {
    494 			syslog(LOG_WARNING,
    495 			    "%s line %d: unknown directive '%s'",
    496 			    infile, (int)line, word);
    497 			continue;
    498 		}
    499  nextline:
    500 		;
    501 	}
    502 	REASSIGN(template, NULL);
    503 	fclose(f);
    504 }
    505 
    506 /*
    507  * Show file listed in curclass.display first time in, and list all the
    508  * files named in curclass.notify in the current directory.
    509  * Send back responses with the prefix `code' + "-".
    510  * If code == -1, flush the internal cache of directory names and return.
    511  */
    512 void
    513 show_chdir_messages(int code)
    514 {
    515 	static StringList *slist = NULL;
    516 
    517 	struct stat st;
    518 	struct tm *t;
    519 	glob_t	 gl;
    520 	time_t	 now, then;
    521 	int	 age;
    522 	char	 curwd[MAXPATHLEN];
    523 	char	*cp, **rlist;
    524 
    525 	if (code == -1) {
    526 		if (slist != NULL)
    527 			sl_free(slist, 1);
    528 		slist = NULL;
    529 		return;
    530 	}
    531 
    532 	if (quietmessages)
    533 		return;
    534 
    535 		/* Setup list for directory cache */
    536 	if (slist == NULL)
    537 		slist = sl_init();
    538 	if (slist == NULL) {
    539 		syslog(LOG_WARNING, "can't allocate memory for stringlist");
    540 		return;
    541 	}
    542 
    543 		/* Check if this directory has already been visited */
    544 	if (getcwd(curwd, sizeof(curwd) - 1) == NULL) {
    545 		syslog(LOG_WARNING, "can't getcwd: %s", strerror(errno));
    546 		return;
    547 	}
    548 	if (sl_find(slist, curwd) != NULL)
    549 		return;
    550 
    551 	cp = ftpd_strdup(curwd);
    552 	if (sl_add(slist, cp) == -1)
    553 		syslog(LOG_WARNING, "can't add `%s' to stringlist", cp);
    554 
    555 		/* First check for a display file */
    556 	(void)display_file(curclass.display, code);
    557 
    558 		/* Now see if there are any notify files */
    559 	if (EMPTYSTR(curclass.notify))
    560 		return;
    561 
    562 	memset(&gl, 0, sizeof(gl));
    563 	if (glob(curclass.notify, GLOB_BRACE|GLOB_LIMIT, NULL, &gl) != 0
    564 	    || gl.gl_matchc == 0) {
    565 		globfree(&gl);
    566 		return;
    567 	}
    568 	time(&now);
    569 	for (rlist = gl.gl_pathv; *rlist != NULL; rlist++) {
    570 		if (stat(*rlist, &st) != 0)
    571 			continue;
    572 		if (!S_ISREG(st.st_mode))
    573 			continue;
    574 		then = st.st_mtime;
    575 		if (code != 0) {
    576 			reply(-code, "%s", "");
    577 			code = 0;
    578 		}
    579 		reply(-code, "Please read the file %s", *rlist);
    580 		t = localtime(&now);
    581 		age = 365 * t->tm_year + t->tm_yday;
    582 		t = localtime(&then);
    583 		age -= 365 * t->tm_year + t->tm_yday;
    584 		reply(-code, "  it was last modified on %.24s - %d day%s ago",
    585 		    ctime(&then), age, PLURAL(age));
    586 	}
    587 	globfree(&gl);
    588 }
    589 
    590 int
    591 display_file(const char *file, int code)
    592 {
    593 	FILE   *f;
    594 	char   *buf, *p;
    595 	char	curwd[MAXPATHLEN];
    596 	size_t	len;
    597 	off_t	lastnum;
    598 	time_t	now;
    599 
    600 	lastnum = 0;
    601 	if (quietmessages)
    602 		return (0);
    603 
    604 	if (EMPTYSTR(file))
    605 		return(0);
    606 	if ((f = fopen(file, "r")) == NULL)
    607 		return (0);
    608 	reply(-code, "%s", "");
    609 
    610 	for (;
    611 	    (buf = fparseln(f, &len, NULL, "\0\0\0", 0)) != NULL; free(buf)) {
    612 		if (len > 0)
    613 			if (buf[len - 1] == '\n')
    614 				buf[--len] = '\0';
    615 		cprintf(stdout, "    ");
    616 
    617 		for (p = buf; *p; p++) {
    618 			if (*p == '%') {
    619 				p++;
    620 				switch (*p) {
    621 
    622 				case 'c':
    623 					cprintf(stdout, "%s",
    624 					    curclass.classname ?
    625 					    curclass.classname : "<unknown>");
    626 					break;
    627 
    628 				case 'C':
    629 					if (getcwd(curwd, sizeof(curwd)-1)
    630 					    == NULL){
    631 						syslog(LOG_WARNING,
    632 						    "can't getcwd: %s",
    633 						    strerror(errno));
    634 						continue;
    635 					}
    636 					cprintf(stdout, "%s", curwd);
    637 					break;
    638 
    639 				case 'E':
    640 					if (! EMPTYSTR(emailaddr))
    641 						cprintf(stdout, "%s",
    642 						    emailaddr);
    643 					break;
    644 
    645 				case 'L':
    646 					cprintf(stdout, "%s", hostname);
    647 					break;
    648 
    649 				case 'M':
    650 					if (curclass.limit == -1) {
    651 						cprintf(stdout, "unlimited");
    652 						lastnum = 0;
    653 					} else {
    654 						cprintf(stdout, LLF,
    655 						    (LLT)curclass.limit);
    656 						lastnum = curclass.limit;
    657 					}
    658 					break;
    659 
    660 				case 'N':
    661 					cprintf(stdout, "%d", connections);
    662 					lastnum = connections;
    663 					break;
    664 
    665 				case 'R':
    666 					cprintf(stdout, "%s", remotehost);
    667 					break;
    668 
    669 				case 's':
    670 					if (lastnum != 1)
    671 						cprintf(stdout, "s");
    672 					break;
    673 
    674 				case 'S':
    675 					if (lastnum != 1)
    676 						cprintf(stdout, "S");
    677 					break;
    678 
    679 				case 'T':
    680 					now = time(NULL);
    681 					cprintf(stdout, "%.24s", ctime(&now));
    682 					break;
    683 
    684 				case 'U':
    685 					cprintf(stdout, "%s",
    686 					    pw ? pw->pw_name : "<unknown>");
    687 					break;
    688 
    689 				case '%':
    690 					CPUTC('%', stdout);
    691 					break;
    692 
    693 				}
    694 			} else
    695 				CPUTC(*p, stdout);
    696 		}
    697 		cprintf(stdout, "\r\n");
    698 	}
    699 
    700 	(void)fflush(stdout);
    701 	(void)fclose(f);
    702 	return (1);
    703 }
    704 
    705 /*
    706  * Parse src, expanding '%' escapes, into dst (which must be at least
    707  * MAXPATHLEN long).
    708  */
    709 void
    710 format_path(char *dst, const char *src)
    711 {
    712 	size_t len;
    713 	const char *p;
    714 
    715 	dst[0] = '\0';
    716 	len = 0;
    717 	if (src == NULL)
    718 		return;
    719 	for (p = src; *p && len < MAXPATHLEN; p++) {
    720 		if (*p == '%') {
    721 			p++;
    722 			switch (*p) {
    723 
    724 			case 'c':
    725 				len += strlcpy(dst + len, curclass.classname,
    726 				    MAXPATHLEN - len);
    727 				break;
    728 
    729 			case 'd':
    730 				len += strlcpy(dst + len, pw->pw_dir,
    731 				    MAXPATHLEN - len);
    732 				break;
    733 
    734 			case 'u':
    735 				len += strlcpy(dst + len, pw->pw_name,
    736 				    MAXPATHLEN - len);
    737 				break;
    738 
    739 			case '%':
    740 				dst[len++] = '%';
    741 				break;
    742 
    743 			}
    744 		} else
    745 			dst[len++] = *p;
    746 	}
    747 	if (len < MAXPATHLEN)
    748 		dst[len] = '\0';
    749 	dst[MAXPATHLEN - 1] = '\0';
    750 }
    751 
    752 /*
    753  * Find s2 at the end of s1.  If found, return a string up to (but
    754  * not including) s2, otherwise returns NULL.
    755  */
    756 static char *
    757 strend(const char *s1, char *s2)
    758 {
    759 	static	char buf[MAXPATHLEN];
    760 
    761 	char	*start;
    762 	size_t	l1, l2;
    763 
    764 	l1 = strlen(s1);
    765 	l2 = strlen(s2);
    766 
    767 	if (l2 >= l1 || l1 >= sizeof(buf))
    768 		return(NULL);
    769 
    770 	strlcpy(buf, s1, sizeof(buf));
    771 	start = buf + (l1 - l2);
    772 
    773 	if (strcmp(start, s2) == 0) {
    774 		*start = '\0';
    775 		return(buf);
    776 	} else
    777 		return(NULL);
    778 }
    779 
    780 static int
    781 filetypematch(char *types, int mode)
    782 {
    783 	for ( ; types[0] != '\0'; types++)
    784 		switch (*types) {
    785 		  case 'd':
    786 			if (S_ISDIR(mode))
    787 				return(1);
    788 			break;
    789 		  case 'f':
    790 			if (S_ISREG(mode))
    791 				return(1);
    792 			break;
    793 		}
    794 	return(0);
    795 }
    796 
    797 /*
    798  * Look for a conversion.  If we succeed, return a pointer to the
    799  * command to execute for the conversion.
    800  *
    801  * The command is stored in a static array so there's no memory
    802  * leak problems, and not too much to change in ftpd.c.  This
    803  * routine doesn't need to be re-entrant unless we start using a
    804  * multi-threaded ftpd, and that's not likely for a while...
    805  */
    806 const char **
    807 do_conversion(const char *fname)
    808 {
    809 	struct ftpconv	*cp;
    810 	struct stat	 st;
    811 	int		 o_errno;
    812 	char		*base = NULL;
    813 	char		*cmd, *p, *lp;
    814 	char	       **argv;
    815 	StringList	*sl;
    816 
    817 	o_errno = errno;
    818 	sl = NULL;
    819 	cmd = NULL;
    820 	for (cp = curclass.conversions; cp != NULL; cp = cp->next) {
    821 		if (cp->suffix == NULL) {
    822 			syslog(LOG_WARNING,
    823 			    "cp->suffix==NULL in conv list; SHOULDN'T HAPPEN!");
    824 			continue;
    825 		}
    826 		if ((base = strend(fname, cp->suffix)) == NULL)
    827 			continue;
    828 		if (cp->types == NULL || cp->disable == NULL ||
    829 		    cp->command == NULL)
    830 			continue;
    831 					/* Is it enabled? */
    832 		if (strcmp(cp->disable, ".") != 0 &&
    833 		    stat(cp->disable, &st) == 0)
    834 				continue;
    835 					/* Does the base exist? */
    836 		if (stat(base, &st) < 0)
    837 			continue;
    838 					/* Is the file type ok */
    839 		if (!filetypematch(cp->types, st.st_mode))
    840 			continue;
    841 		break;			/* "We have a winner!" */
    842 	}
    843 
    844 	/* If we got through the list, no conversion */
    845 	if (cp == NULL)
    846 		goto cleanup_do_conv;
    847 
    848 	/* Split up command into an argv */
    849 	if ((sl = sl_init()) == NULL)
    850 		goto cleanup_do_conv;
    851 	cmd = ftpd_strdup(cp->command);
    852 	p = cmd;
    853 	while (p) {
    854 		NEXTWORD(p, lp);
    855 		if (strcmp(lp, "%s") == 0)
    856 			lp = base;
    857 		if (sl_add(sl, ftpd_strdup(lp)) == -1)
    858 			goto cleanup_do_conv;
    859 	}
    860 
    861 	if (sl_add(sl, NULL) == -1)
    862 		goto cleanup_do_conv;
    863 	argv = sl->sl_str;
    864 	free(cmd);
    865 	free(sl);
    866 	return (void *)(intptr_t)argv;
    867 
    868  cleanup_do_conv:
    869 	if (sl)
    870 		sl_free(sl, 1);
    871 	free(cmd);
    872 	errno = o_errno;
    873 	return(NULL);
    874 }
    875 
    876 /*
    877  * Count the number of current connections, reading from
    878  *	/var/run/ftpd.pids-<class>
    879  * Does a kill -0 on each pid in that file, and only counts
    880  * processes that exist (or frees the slot if it doesn't).
    881  * Adds getpid() to the first free slot. Truncates the file
    882  * if possible.
    883  */
    884 void
    885 count_users(void)
    886 {
    887 	char	fn[MAXPATHLEN];
    888 	int	fd;
    889 	size_t	i, last, count;
    890 	ssize_t	scount;
    891 	pid_t  *pids, mypid;
    892 	struct stat sb;
    893 	struct flock fl;
    894 
    895 	(void)strlcpy(fn, _PATH_CLASSPIDS, sizeof(fn));
    896 	(void)strlcat(fn, curclass.classname, sizeof(fn));
    897 	pids = NULL;
    898 	connections = 1;
    899 	fl.l_start = 0;
    900 	fl.l_len = 0;
    901 	fl.l_pid = 0;
    902 	fl.l_type = F_WRLCK;
    903 	fl.l_whence = SEEK_SET;
    904 
    905 	if ((fd = open(fn, O_RDWR | O_CREAT, 0600)) == -1)
    906 		return;
    907 	if (fcntl(fd, F_SETLK, &fl) == -1)
    908 		goto cleanup_count;
    909 	if (fstat(fd, &sb) == -1)
    910 		goto cleanup_count;
    911 	if ((pids = malloc(sb.st_size + sizeof(pid_t))) == NULL)
    912 		goto cleanup_count;
    913 /* XXX: implement a better read loop */
    914 	scount = read(fd, pids, sb.st_size);
    915 	if (scount == -1 || scount != sb.st_size || scount < 0)
    916 		goto cleanup_count;
    917 	count = (size_t)scount / sizeof(pid_t);
    918 	mypid = getpid();
    919 	last = 0;
    920 	for (i = 0; i < count; i++) {
    921 		if (pids[i] == 0)
    922 			continue;
    923 		if (kill(pids[i], 0) == -1 && errno != EPERM) {
    924 			if (mypid != 0) {
    925 				pids[i] = mypid;
    926 				mypid = 0;
    927 				last = i;
    928 			}
    929 		} else {
    930 			connections++;
    931 			last = i;
    932 		}
    933 	}
    934 	if (mypid != 0) {
    935 		if (pids[last] != 0)
    936 			last++;
    937 		pids[last] = mypid;
    938 	}
    939 	count = (last + 1) * sizeof(pid_t);
    940 	if (lseek(fd, 0, SEEK_SET) == -1)
    941 		goto cleanup_count;
    942 /* XXX: implement a better write loop */
    943 	scount = write(fd, pids, count);
    944 	if (scount == -1 || (size_t)scount != count)
    945 		goto cleanup_count;
    946 	(void)ftruncate(fd, count);
    947 
    948  cleanup_count:
    949 	fl.l_type = F_UNLCK;
    950 	(void)fcntl(fd, F_SETLK, &fl);
    951 	close(fd);
    952 	REASSIGN(pids, NULL);
    953 }
    954