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authpf.c revision 1.2
      1 /*	$NetBSD: authpf.c,v 1.2 2004/06/25 00:06:09 itojun Exp $	*/
      2 /*	$OpenBSD: authpf.c,v 1.75 2004/01/29 01:55:10 deraadt Exp $	*/
      3 
      4 /*
      5  * Copyright (C) 1998 - 2002 Bob Beck (beck (at) openbsd.org).
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/types.h>
     30 #include <sys/file.h>
     31 #include <sys/ioctl.h>
     32 #include <sys/socket.h>
     33 #include <sys/time.h>
     34 #include <sys/param.h>
     35 
     36 #include <net/if.h>
     37 #include <netinet/in.h>
     38 #include <net/pfvar.h>
     39 #include <arpa/inet.h>
     40 
     41 #include <err.h>
     42 #include <errno.h>
     43 #include <pwd.h>
     44 #include <signal.h>
     45 #include <stdio.h>
     46 #include <stdlib.h>
     47 #include <string.h>
     48 #include <syslog.h>
     49 #include <unistd.h>
     50 
     51 #include <pfctl_parser.h>
     52 #include <pfctl.h>
     53 
     54 #include "pathnames.h"
     55 
     56 extern int	symset(const char *, const char *, int);
     57 
     58 static int	read_config(FILE *);
     59 static void	print_message(char *);
     60 static int	allowed_luser(char *);
     61 static int	check_luser(char *, char *);
     62 static int	remove_stale_rulesets(void);
     63 static int	change_filter(int, const char *, const char *);
     64 static void	authpf_kill_states(void);
     65 
     66 int	dev;			/* pf device */
     67 char	anchorname[PF_ANCHOR_NAME_SIZE] = "authpf";
     68 char	rulesetname[PF_RULESET_NAME_SIZE];
     69 
     70 FILE	*pidfp;
     71 char	*infile;		/* file name printed by yyerror() in parse.y */
     72 char	 luser[MAXLOGNAME];	/* username */
     73 char	 ipsrc[256];		/* ip as a string */
     74 char	 pidfile[MAXPATHLEN];	/* we save pid in this file. */
     75 
     76 struct timeval	Tstart, Tend;	/* start and end times of session */
     77 
     78 volatile sig_atomic_t	want_death;
     79 static void		need_death(int signo);
     80 static __dead void	do_death(int);
     81 
     82 /*
     83  * User shell for authenticating gateways. Sole purpose is to allow
     84  * a user to ssh to a gateway, and have the gateway modify packet
     85  * filters to allow access, then remove access when the user finishes
     86  * up. Meant to be used only from ssh(1) connections.
     87  */
     88 int
     89 main(int argc, char *argv[])
     90 {
     91 	int		 lockcnt = 0, n, pidfd;
     92 	FILE		*config;
     93 	struct in_addr	 ina;
     94 	struct passwd	*pw;
     95 	char		*cp;
     96 	uid_t		 uid;
     97 
     98 	config = fopen(PATH_CONFFILE, "r");
     99 
    100 	if ((cp = getenv("SSH_TTY")) == NULL) {
    101 		syslog(LOG_ERR, "non-interactive session connection for authpf");
    102 		exit(1);
    103 	}
    104 
    105 	if ((cp = getenv("SSH_CLIENT")) == NULL) {
    106 		syslog(LOG_ERR, "cannot determine connection source");
    107 		exit(1);
    108 	}
    109 
    110 	if (strlcpy(ipsrc, cp, sizeof(ipsrc)) >= sizeof(ipsrc)) {
    111 		syslog(LOG_ERR, "SSH_CLIENT variable too long");
    112 		exit(1);
    113 	}
    114 	cp = strchr(ipsrc, ' ');
    115 	if (!cp) {
    116 		syslog(LOG_ERR, "corrupt SSH_CLIENT variable %s", ipsrc);
    117 		exit(1);
    118 	}
    119 	*cp = '\0';
    120 	if (inet_pton(AF_INET, ipsrc, &ina) != 1) {
    121 		syslog(LOG_ERR,
    122 		    "cannot determine IP from SSH_CLIENT %s", ipsrc);
    123 		exit(1);
    124 	}
    125 	/* open the pf device */
    126 	dev = open(PATH_DEVFILE, O_RDWR);
    127 	if (dev == -1) {
    128 		syslog(LOG_ERR, "cannot open packet filter device (%m)");
    129 		goto die;
    130 	}
    131 
    132 	uid = getuid();
    133 	pw = getpwuid(uid);
    134 	if (pw == NULL) {
    135 		syslog(LOG_ERR, "cannot find user for uid %u", uid);
    136 		goto die;
    137 	}
    138 	if (strcmp(pw->pw_shell, PATH_AUTHPF_SHELL)) {
    139 		syslog(LOG_ERR, "wrong shell for user %s, uid %u",
    140 		    pw->pw_name, pw->pw_uid);
    141 		goto die;
    142 	}
    143 
    144 	/*
    145 	 * Paranoia, but this data _does_ come from outside authpf, and
    146 	 * truncation would be bad.
    147 	 */
    148 	if (strlcpy(luser, pw->pw_name, sizeof(luser)) >= sizeof(luser)) {
    149 		syslog(LOG_ERR, "username too long: %s", pw->pw_name);
    150 		goto die;
    151 	}
    152 
    153 	if ((n = snprintf(rulesetname, sizeof(rulesetname), "%s(%ld)",
    154 	    luser, (long)getpid())) < 0 || n >= sizeof(rulesetname)) {
    155 		syslog(LOG_INFO, "%s(%ld) too large, ruleset name will be %ld",
    156 		    luser, (long)getpid(), (long)getpid());
    157 		if ((n = snprintf(rulesetname, sizeof(rulesetname), "%ld",
    158 		    (long)getpid())) < 0 || n >= sizeof(rulesetname)) {
    159 			syslog(LOG_ERR, "pid too large for ruleset name");
    160 			goto die;
    161 		}
    162 	}
    163 
    164 
    165 	/* Make our entry in /var/authpf as /var/authpf/ipaddr */
    166 	n = snprintf(pidfile, sizeof(pidfile), "%s/%s", PATH_PIDFILE, ipsrc);
    167 	if (n < 0 || (u_int)n >= sizeof(pidfile)) {
    168 		syslog(LOG_ERR, "path to pidfile too long");
    169 		goto die;
    170 	}
    171 
    172 	/*
    173 	 * If someone else is already using this ip, then this person
    174 	 * wants to switch users - so kill the old process and exit
    175 	 * as well.
    176 	 *
    177 	 * Note, we could print a message and tell them to log out, but the
    178 	 * usual case of this is that someone has left themselves logged in,
    179 	 * with the authenticated connection iconized and someone else walks
    180 	 * up to use and automatically logs in before using. If this just
    181 	 * gets rid of the old one silently, the new user never knows they
    182 	 * could have used someone else's old authentication. If we
    183 	 * tell them to log out before switching users it is an invitation
    184 	 * for abuse.
    185 	 */
    186 
    187 	do {
    188 		int	save_errno, otherpid = -1;
    189 		char	otherluser[MAXLOGNAME];
    190 
    191 		if ((pidfd = open(pidfile, O_RDWR|O_CREAT, 0644)) == -1 ||
    192 		    (pidfp = fdopen(pidfd, "r+")) == NULL) {
    193 			if (pidfd != -1)
    194 				close(pidfd);
    195 			syslog(LOG_ERR, "cannot open or create %s: %s", pidfile,
    196 			    strerror(errno));
    197 			goto die;
    198 		}
    199 
    200 		if (flock(fileno(pidfp), LOCK_EX|LOCK_NB) == 0)
    201 			break;
    202 		save_errno = errno;
    203 
    204 		/* Mark our pid, and username to our file. */
    205 
    206 		rewind(pidfp);
    207 		/* 31 == MAXLOGNAME - 1 */
    208 		if (fscanf(pidfp, "%d\n%31s\n", &otherpid, otherluser) != 2)
    209 			otherpid = -1;
    210 		syslog(LOG_DEBUG, "tried to lock %s, in use by pid %d: %s",
    211 		    pidfile, otherpid, strerror(save_errno));
    212 
    213 		if (otherpid > 0) {
    214 			syslog(LOG_INFO,
    215 			    "killing prior auth (pid %d) of %s by user %s",
    216 			    otherpid, ipsrc, otherluser);
    217 			if (kill((pid_t) otherpid, SIGTERM) == -1) {
    218 				syslog(LOG_INFO,
    219 				    "could not kill process %d: (%m)",
    220 				    otherpid);
    221 			}
    222 		}
    223 
    224 		/*
    225 		 * we try to kill the previous process and acquire the lock
    226 		 * for 10 seconds, trying once a second. if we can't after
    227 		 * 10 attempts we log an error and give up
    228 		 */
    229 		if (++lockcnt > 10) {
    230 			syslog(LOG_ERR, "cannot kill previous authpf (pid %d)",
    231 			    otherpid);
    232 			goto dogdeath;
    233 		}
    234 		sleep(1);
    235 
    236 		/* re-open, and try again. The previous authpf process
    237 		 * we killed above should unlink the file and release
    238 		 * it's lock, giving us a chance to get it now
    239 		 */
    240 		fclose(pidfp);
    241 	} while (1);
    242 
    243 	/* revoke privs */
    244 	seteuid(getuid());
    245 	setuid(getuid());
    246 
    247 	openlog("authpf", LOG_PID | LOG_NDELAY, LOG_DAEMON);
    248 
    249 	if (!check_luser(PATH_BAN_DIR, luser) || !allowed_luser(luser)) {
    250 		syslog(LOG_INFO, "user %s prohibited", luser);
    251 		do_death(0);
    252 	}
    253 
    254 	if (config == NULL || read_config(config)) {
    255 		syslog(LOG_INFO, "bad or nonexistent %s", PATH_CONFFILE);
    256 		do_death(0);
    257 	}
    258 
    259 	if (remove_stale_rulesets()) {
    260 		syslog(LOG_INFO, "error removing stale rulesets");
    261 		do_death(0);
    262 	}
    263 
    264 	/* We appear to be making headway, so actually mark our pid */
    265 	rewind(pidfp);
    266 	fprintf(pidfp, "%ld\n%s\n", (long)getpid(), luser);
    267 	fflush(pidfp);
    268 	(void) ftruncate(fileno(pidfp), ftell(pidfp));
    269 
    270 	if (change_filter(1, luser, ipsrc) == -1) {
    271 		printf("Unable to modify filters\r\n");
    272 		do_death(0);
    273 	}
    274 
    275 	signal(SIGTERM, need_death);
    276 	signal(SIGINT, need_death);
    277 	signal(SIGALRM, need_death);
    278 	signal(SIGPIPE, need_death);
    279 	signal(SIGHUP, need_death);
    280 	signal(SIGSTOP, need_death);
    281 	signal(SIGTSTP, need_death);
    282 	while (1) {
    283 		printf("\r\nHello %s, ", luser);
    284 		printf("You are authenticated from host \"%s\"\r\n", ipsrc);
    285 		setproctitle("%s@%s", luser, ipsrc);
    286 		print_message(PATH_MESSAGE);
    287 		while (1) {
    288 			sleep(10);
    289 			if (want_death)
    290 				do_death(1);
    291 		}
    292 	}
    293 
    294 	/* NOTREACHED */
    295 dogdeath:
    296 	printf("\r\n\r\nSorry, this service is currently unavailable due to ");
    297 	printf("technical difficulties\r\n\r\n");
    298 	print_message(PATH_PROBLEM);
    299 	printf("\r\nYour authentication process (pid %ld) was unable to run\n",
    300 	    (long)getpid());
    301 	sleep(180); /* them lusers read reaaaaal slow */
    302 die:
    303 	do_death(0);
    304 	return (0);
    305 }
    306 
    307 /*
    308  * reads config file in PATH_CONFFILE to set optional behaviours up
    309  */
    310 static int
    311 read_config(FILE *f)
    312 {
    313 	char	buf[1024];
    314 	int	i = 0;
    315 
    316 	do {
    317 		char	**ap;
    318 		char	 *pair[4], *cp, *tp;
    319 		int	  len;
    320 
    321 		if (fgets(buf, sizeof(buf), f) == NULL) {
    322 			fclose(f);
    323 			return (0);
    324 		}
    325 		i++;
    326 		len = strlen(buf);
    327 		if (buf[len - 1] != '\n' && !feof(f)) {
    328 			syslog(LOG_ERR, "line %d too long in %s", i,
    329 			    PATH_CONFFILE);
    330 			return (1);
    331 		}
    332 		buf[len - 1] = '\0';
    333 
    334 		for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
    335 			; /* nothing */
    336 
    337 		if (!*cp || *cp == '#' || *cp == '\n')
    338 			continue;
    339 
    340 		for (ap = pair; ap < &pair[3] &&
    341 		    (*ap = strsep(&cp, "=")) != NULL; ) {
    342 			if (**ap != '\0')
    343 				ap++;
    344 		}
    345 		if (ap != &pair[2])
    346 			goto parse_error;
    347 
    348 		tp = pair[1] + strlen(pair[1]);
    349 		while ((*tp == ' ' || *tp == '\t') && tp >= pair[1])
    350 			*tp-- = '\0';
    351 
    352 		if (strcasecmp(pair[0], "anchor") == 0) {
    353 			if (!pair[1][0] || strlcpy(anchorname, pair[1],
    354 			    sizeof(anchorname)) >= sizeof(anchorname))
    355 				goto parse_error;
    356 		}
    357 	} while (!feof(f) && !ferror(f));
    358 	fclose(f);
    359 	return (0);
    360 
    361 parse_error:
    362 	fclose(f);
    363 	syslog(LOG_ERR, "parse error, line %d of %s", i, PATH_CONFFILE);
    364 	return (1);
    365 }
    366 
    367 
    368 /*
    369  * splatter a file to stdout - max line length of 1024,
    370  * used for spitting message files at users to tell them
    371  * they've been bad or we're unavailable.
    372  */
    373 static void
    374 print_message(char *filename)
    375 {
    376 	char	 buf[1024];
    377 	FILE	*f;
    378 
    379 	if ((f = fopen(filename, "r")) == NULL)
    380 		return; /* fail silently, we don't care if it isn't there */
    381 
    382 	do {
    383 		if (fgets(buf, sizeof(buf), f) == NULL) {
    384 			fflush(stdout);
    385 			fclose(f);
    386 			return;
    387 		}
    388 	} while (fputs(buf, stdout) != EOF && !feof(f));
    389 	fflush(stdout);
    390 	fclose(f);
    391 }
    392 
    393 /*
    394  * allowed_luser checks to see if user "luser" is allowed to
    395  * use this gateway by virtue of being listed in an allowed
    396  * users file, namely /etc/authpf/authpf.allow .
    397  *
    398  * If /etc/authpf/authpf.allow does not exist, then we assume that
    399  * all users who are allowed in by sshd(8) are permitted to
    400  * use this gateway. If /etc/authpf/authpf.allow does exist, then a
    401  * user must be listed if the connection is to continue, else
    402  * the session terminates in the same manner as being banned.
    403  */
    404 static int
    405 allowed_luser(char *luser)
    406 {
    407 	char	*buf, *lbuf;
    408 	int	 matched;
    409 	size_t	 len;
    410 	FILE	*f;
    411 
    412 	if ((f = fopen(PATH_ALLOWFILE, "r")) == NULL) {
    413 		if (errno == ENOENT) {
    414 			/*
    415 			 * allowfile doesn't exist, thus this gateway
    416 			 * isn't restricted to certain users...
    417 			 */
    418 			return (1);
    419 		}
    420 
    421 		/*
    422 		 * luser may in fact be allowed, but we can't open
    423 		 * the file even though it's there. probably a config
    424 		 * problem.
    425 		 */
    426 		syslog(LOG_ERR, "cannot open allowed users file %s (%s)",
    427 		    PATH_ALLOWFILE, strerror(errno));
    428 		return (0);
    429 	} else {
    430 		/*
    431 		 * /etc/authpf/authpf.allow exists, thus we do a linear
    432 		 * search to see if they are allowed.
    433 		 * also, if username "*" exists, then this is a
    434 		 * "public" gateway, such as it is, so let
    435 		 * everyone use it.
    436 		 */
    437 		lbuf = NULL;
    438 		while ((buf = fgetln(f, &len))) {
    439 			if (buf[len - 1] == '\n')
    440 				buf[len - 1] = '\0';
    441 			else {
    442 				if ((lbuf = (char *)malloc(len + 1)) == NULL)
    443 					err(1, NULL);
    444 				memcpy(lbuf, buf, len);
    445 				lbuf[len] = '\0';
    446 				buf = lbuf;
    447 			}
    448 
    449 			matched = strcmp(luser, buf) == 0 || strcmp("*", buf) == 0;
    450 
    451 			if (lbuf != NULL) {
    452 				free(lbuf);
    453 				lbuf = NULL;
    454 			}
    455 
    456 			if (matched)
    457 				return (1); /* matched an allowed username */
    458 		}
    459 		syslog(LOG_INFO, "denied access to %s: not listed in %s",
    460 		    luser, PATH_ALLOWFILE);
    461 
    462 		/* reuse buf */
    463 		buf = "\n\nSorry, you are not allowed to use this facility!\n";
    464 		fputs(buf, stdout);
    465 	}
    466 	fflush(stdout);
    467 	return (0);
    468 }
    469 
    470 /*
    471  * check_luser checks to see if user "luser" has been banned
    472  * from using us by virtue of having an file of the same name
    473  * in the "luserdir" directory.
    474  *
    475  * If the user has been banned, we copy the contents of the file
    476  * to the user's screen. (useful for telling the user what to
    477  * do to get un-banned, or just to tell them they aren't
    478  * going to be un-banned.)
    479  */
    480 static int
    481 check_luser(char *luserdir, char *luser)
    482 {
    483 	FILE	*f;
    484 	int	 n;
    485 	char	 tmp[MAXPATHLEN];
    486 
    487 	n = snprintf(tmp, sizeof(tmp), "%s/%s", luserdir, luser);
    488 	if (n < 0 || (u_int)n >= sizeof(tmp)) {
    489 		syslog(LOG_ERR, "provided banned directory line too long (%s)",
    490 		    luserdir);
    491 		return (0);
    492 	}
    493 	if ((f = fopen(tmp, "r")) == NULL) {
    494 		if (errno == ENOENT) {
    495 			/*
    496 			 * file or dir doesn't exist, so therefore
    497 			 * this luser isn't banned..  all is well
    498 			 */
    499 			return (1);
    500 		} else {
    501 			/*
    502 			 * luser may in fact be banned, but we can't open the
    503 			 * file even though it's there. probably a config
    504 			 * problem.
    505 			 */
    506 			syslog(LOG_ERR, "cannot open banned file %s (%s)",
    507 			    tmp, strerror(errno));
    508 			return (0);
    509 		}
    510 	} else {
    511 		/*
    512 		 * luser is banned - spit the file at them to
    513 		 * tell what they can do and where they can go.
    514 		 */
    515 		syslog(LOG_INFO, "denied access to %s: %s exists",
    516 		    luser, tmp);
    517 
    518 		/* reuse tmp */
    519 		strlcpy(tmp, "\n\n-**- Sorry, you have been banned! -**-\n\n",
    520 		    sizeof(tmp));
    521 		while (fputs(tmp, stdout) != EOF && !feof(f)) {
    522 			if (fgets(tmp, sizeof(tmp), f) == NULL) {
    523 				fflush(stdout);
    524 				return (0);
    525 			}
    526 		}
    527 	}
    528 	fflush(stdout);
    529 	return (0);
    530 }
    531 
    532 /*
    533  * Search for rulesets left by other authpf processes (either because they
    534  * died ungracefully or were terminated) and remove them.
    535  */
    536 static int
    537 remove_stale_rulesets(void)
    538 {
    539 	struct pfioc_ruleset	 prs;
    540 	const int		 action[PF_RULESET_MAX] = { PF_SCRUB,
    541 				    PF_PASS, PF_NAT, PF_BINAT, PF_RDR };
    542 	u_int32_t		 nr, mnr;
    543 
    544 	memset(&prs, 0, sizeof(prs));
    545 	strlcpy(prs.anchor, anchorname, sizeof(prs.anchor));
    546 	if (ioctl(dev, DIOCGETRULESETS, &prs)) {
    547 		if (errno == EINVAL)
    548 			return (0);
    549 		else
    550 			return (1);
    551 	}
    552 
    553 	mnr = prs.nr;
    554 	nr = 0;
    555 	while (nr < mnr) {
    556 		char	*s, *t;
    557 		pid_t	 pid;
    558 
    559 		prs.nr = nr;
    560 		if (ioctl(dev, DIOCGETRULESET, &prs))
    561 			return (1);
    562 		errno = 0;
    563 		if ((t = strchr(prs.name, '(')) == NULL)
    564 			t = prs.name;
    565 		else
    566 			t++;
    567 		pid = strtoul(t, &s, 10);
    568 		if (!prs.name[0] || errno ||
    569 		    (*s && (t == prs.name || *s != ')')))
    570 			return (1);
    571 		if (kill(pid, 0) && errno != EPERM) {
    572 			int i;
    573 
    574 			for (i = 0; i < PF_RULESET_MAX; ++i) {
    575 				struct pfioc_rule pr;
    576 
    577 				memset(&pr, 0, sizeof(pr));
    578 				memcpy(pr.anchor, prs.anchor, sizeof(pr.anchor));
    579 				memcpy(pr.ruleset, prs.name, sizeof(pr.ruleset));
    580 				pr.rule.action = action[i];
    581 				if ((ioctl(dev, DIOCBEGINRULES, &pr) ||
    582 				    ioctl(dev, DIOCCOMMITRULES, &pr)) &&
    583 				    errno != EINVAL)
    584 					return (1);
    585 			}
    586 			mnr--;
    587 		} else
    588 			nr++;
    589 	}
    590 	return (0);
    591 }
    592 
    593 /*
    594  * Add/remove filter entries for user "luser" from ip "ipsrc"
    595  */
    596 static int
    597 change_filter(int add, const char *luser, const char *ipsrc)
    598 {
    599 	char			 fn[MAXPATHLEN];
    600 	FILE			*f = NULL;
    601 	struct pfctl		 pf;
    602 	struct pfr_buffer	 t;
    603 	int			 i;
    604 
    605 	if (luser == NULL || !luser[0] || ipsrc == NULL || !ipsrc[0]) {
    606 		syslog(LOG_ERR, "invalid luser/ipsrc");
    607 		goto error;
    608 	}
    609 
    610 	if (add) {
    611 		if ((i = snprintf(fn, sizeof(fn), "%s/%s/authpf.rules",
    612 		    PATH_USER_DIR, luser)) < 0 || i >= sizeof(fn)) {
    613 			syslog(LOG_ERR, "user rule path too long");
    614 			goto error;
    615 		}
    616 		if ((f = fopen(fn, "r")) == NULL && errno != ENOENT) {
    617 			syslog(LOG_ERR, "cannot open %s (%m)", fn);
    618 			goto error;
    619 		}
    620 		if (f == NULL) {
    621 			if (strlcpy(fn, PATH_PFRULES, sizeof(fn)) >=
    622 			    sizeof(fn)) {
    623 				syslog(LOG_ERR, "rule path too long");
    624 				goto error;
    625 			}
    626 			if ((f = fopen(fn, "r")) == NULL) {
    627 				syslog(LOG_ERR, "cannot open %s (%m)", fn);
    628 				goto error;
    629 			}
    630 		}
    631 	}
    632 
    633 	if (pfctl_load_fingerprints(dev, 0)) {
    634 		syslog(LOG_ERR, "unable to load kernel's OS fingerprints");
    635 		goto error;
    636 	}
    637 	bzero(&t, sizeof(t));
    638 	t.pfrb_type = PFRB_TRANS;
    639 	memset(&pf, 0, sizeof(pf));
    640 	for (i = 0; i < PF_RULESET_MAX; ++i) {
    641 		if (pfctl_add_trans(&t, i, anchorname, rulesetname)) {
    642 			syslog(LOG_ERR, "pfctl_add_trans %m");
    643 			goto error;
    644 		}
    645 	}
    646 	if (pfctl_trans(dev, &t, DIOCXBEGIN, 0)) {
    647 		syslog(LOG_ERR, "DIOCXBEGIN (%s) %m", add?"add":"remove");
    648 		goto error;
    649 	}
    650 
    651 	if (add) {
    652 		if (symset("user_ip", ipsrc, 0) ||
    653 		    symset("user_id", luser, 0)) {
    654 			syslog(LOG_ERR, "symset");
    655 			goto error;
    656 		}
    657 
    658 		pf.dev = dev;
    659 		pf.trans = &t;
    660 		pf.anchor = anchorname;
    661 		pf.ruleset = rulesetname;
    662 
    663 		infile = fn;
    664 		if (parse_rules(f, &pf) < 0) {
    665 			syslog(LOG_ERR, "syntax error in rule file: "
    666 			    "authpf rules not loaded");
    667 			goto error;
    668 		}
    669 
    670 		infile = NULL;
    671 		fclose(f);
    672 		f = NULL;
    673 	}
    674 
    675 	if (pfctl_trans(dev, &t, DIOCXCOMMIT, 0)) {
    676 		syslog(LOG_ERR, "DIOCXCOMMIT (%s) %m", add?"add":"remove");
    677 		goto error;
    678 	}
    679 
    680 	if (add) {
    681 		gettimeofday(&Tstart, NULL);
    682 		syslog(LOG_INFO, "allowing %s, user %s", ipsrc, luser);
    683 	} else {
    684 		gettimeofday(&Tend, NULL);
    685 		syslog(LOG_INFO, "removed %s, user %s - duration %ld seconds",
    686 		    ipsrc, luser, Tend.tv_sec - Tstart.tv_sec);
    687 	}
    688 	return (0);
    689 
    690 error:
    691 	if (f != NULL)
    692 		fclose(f);
    693 	if (pfctl_trans(dev, &t, DIOCXROLLBACK, 0))
    694 		syslog(LOG_ERR, "DIOCXROLLBACK (%s) %m", add?"add":"remove");
    695 
    696 	infile = NULL;
    697 	return (-1);
    698 }
    699 
    700 /*
    701  * This is to kill off states that would otherwise be left behind stateful
    702  * rules. This means we don't need to allow in more traffic than we really
    703  * want to, since we don't have to worry about any luser sessions lasting
    704  * longer than their ssh session. This function is based on
    705  * pfctl_kill_states from pfctl.
    706  */
    707 static void
    708 authpf_kill_states(void)
    709 {
    710 	struct pfioc_state_kill	psk;
    711 	struct in_addr		target;
    712 
    713 	memset(&psk, 0, sizeof(psk));
    714 	psk.psk_af = AF_INET;
    715 
    716 	inet_pton(AF_INET, ipsrc, &target);
    717 
    718 	/* Kill all states from ipsrc */
    719 	psk.psk_src.addr.v.a.addr.v4 = target;
    720 	memset(&psk.psk_src.addr.v.a.mask, 0xff,
    721 	    sizeof(psk.psk_src.addr.v.a.mask));
    722 	if (ioctl(dev, DIOCKILLSTATES, &psk))
    723 		syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)");
    724 
    725 	/* Kill all states to ipsrc */
    726 	psk.psk_af = AF_INET;
    727 	memset(&psk.psk_src, 0, sizeof(psk.psk_src));
    728 	psk.psk_dst.addr.v.a.addr.v4 = target;
    729 	memset(&psk.psk_dst.addr.v.a.mask, 0xff,
    730 	    sizeof(psk.psk_dst.addr.v.a.mask));
    731 	if (ioctl(dev, DIOCKILLSTATES, &psk))
    732 		syslog(LOG_ERR, "DIOCKILLSTATES failed (%m)");
    733 }
    734 
    735 /* signal handler that makes us go away properly */
    736 static void
    737 need_death(int signo)
    738 {
    739 	want_death = 1;
    740 }
    741 
    742 /*
    743  * function that removes our stuff when we go away.
    744  */
    745 static __dead void
    746 do_death(int active)
    747 {
    748 	int	ret = 0;
    749 
    750 	if (active) {
    751 		change_filter(0, luser, ipsrc);
    752 		authpf_kill_states();
    753 		remove_stale_rulesets();
    754 	}
    755 	if (pidfp)
    756 		ftruncate(fileno(pidfp), 0);
    757 	if (pidfile[0])
    758 		if (unlink(pidfile) == -1)
    759 			syslog(LOG_ERR, "cannot unlink %s (%m)", pidfile);
    760 	exit(ret);
    761 }
    762 
    763 /*
    764  * callbacks for parse_rules(void)
    765  */
    766 
    767 int
    768 pfctl_add_rule(struct pfctl *pf, struct pf_rule *r)
    769 {
    770 	u_int8_t		rs_num;
    771 	struct pfioc_rule	pr;
    772 
    773 	switch (r->action) {
    774 	case PF_PASS:
    775 	case PF_DROP:
    776 		rs_num = PF_RULESET_FILTER;
    777 		break;
    778 	case PF_SCRUB:
    779 		rs_num = PF_RULESET_SCRUB;
    780 		break;
    781 	case PF_NAT:
    782 	case PF_NONAT:
    783 		rs_num = PF_RULESET_NAT;
    784 		break;
    785 	case PF_RDR:
    786 	case PF_NORDR:
    787 		rs_num = PF_RULESET_RDR;
    788 		break;
    789 	case PF_BINAT:
    790 	case PF_NOBINAT:
    791 		rs_num = PF_RULESET_BINAT;
    792 		break;
    793 	default:
    794 		syslog(LOG_ERR, "invalid rule action %d", r->action);
    795 		return (1);
    796 	}
    797 
    798 	bzero(&pr, sizeof(pr));
    799 	strlcpy(pr.anchor, pf->anchor, sizeof(pr.anchor));
    800 	strlcpy(pr.ruleset, pf->ruleset, sizeof(pr.ruleset));
    801 	if (pfctl_add_pool(pf, &r->rpool, r->af))
    802 		return (1);
    803 	pr.ticket = pfctl_get_ticket(pf->trans, rs_num, pf->anchor,
    804 	    pf->ruleset);
    805 	pr.pool_ticket = pf->paddr.ticket;
    806 	memcpy(&pr.rule, r, sizeof(pr.rule));
    807 	if (ioctl(pf->dev, DIOCADDRULE, &pr)) {
    808 		syslog(LOG_ERR, "DIOCADDRULE %m");
    809 		return (1);
    810 	}
    811 	pfctl_clear_pool(&r->rpool);
    812 	return (0);
    813 }
    814 
    815 int
    816 pfctl_add_pool(struct pfctl *pf, struct pf_pool *p, sa_family_t af)
    817 {
    818 	struct pf_pooladdr	*pa;
    819 
    820 	if (ioctl(pf->dev, DIOCBEGINADDRS, &pf->paddr)) {
    821 		syslog(LOG_ERR, "DIOCBEGINADDRS %m");
    822 		return (1);
    823 	}
    824 	pf->paddr.af = af;
    825 	TAILQ_FOREACH(pa, &p->list, entries) {
    826 		memcpy(&pf->paddr.addr, pa, sizeof(struct pf_pooladdr));
    827 		if (ioctl(pf->dev, DIOCADDADDR, &pf->paddr)) {
    828 			syslog(LOG_ERR, "DIOCADDADDR %m");
    829 			return (1);
    830 		}
    831 	}
    832 	return (0);
    833 }
    834 
    835 void
    836 pfctl_clear_pool(struct pf_pool *pool)
    837 {
    838 	struct pf_pooladdr	*pa;
    839 
    840 	while ((pa = TAILQ_FIRST(&pool->list)) != NULL) {
    841 		TAILQ_REMOVE(&pool->list, pa, entries);
    842 		free(pa);
    843 	}
    844 }
    845 
    846 int
    847 pfctl_add_altq(struct pfctl *pf, struct pf_altq *a)
    848 {
    849 	fprintf(stderr, "altq rules not supported in authpf\n");
    850 	return (1);
    851 }
    852 
    853 int
    854 pfctl_set_optimization(struct pfctl *pf, const char *opt)
    855 {
    856 	fprintf(stderr, "set optimization not supported in authpf\n");
    857 	return (1);
    858 }
    859 
    860 int
    861 pfctl_set_logif(struct pfctl *pf, char *ifname)
    862 {
    863 	fprintf(stderr, "set loginterface not supported in authpf\n");
    864 	return (1);
    865 }
    866 
    867 int
    868 pfctl_set_hostid(struct pfctl *pf, u_int32_t hostid)
    869 {
    870 	fprintf(stderr, "set hostid not supported in authpf\n");
    871 	return (1);
    872 }
    873 
    874 int
    875 pfctl_set_timeout(struct pfctl *pf, const char *opt, int seconds, int quiet)
    876 {
    877 	fprintf(stderr, "set timeout not supported in authpf\n");
    878 	return (1);
    879 }
    880 
    881 int
    882 pfctl_set_limit(struct pfctl *pf, const char *opt, unsigned int limit)
    883 {
    884 	fprintf(stderr, "set limit not supported in authpf\n");
    885 	return (1);
    886 }
    887 
    888 int
    889 pfctl_set_debug(struct pfctl *pf, char *d)
    890 {
    891 	fprintf(stderr, "set debug not supported in authpf\n");
    892 	return (1);
    893 }
    894 
    895 int
    896 pfctl_define_table(char *name, int flags, int addrs, const char *anchor,
    897     const char *ruleset, struct pfr_buffer *ab, u_int32_t ticket)
    898 {
    899 	fprintf(stderr, "table definitions not yet supported in authpf\n");
    900 	return (1);
    901 }
    902 
    903 int
    904 pfctl_rules(int dev, char *filename, int opts, char *anchorname,
    905     char *rulesetname, struct pfr_buffer *t)
    906 {
    907 	/* never called, no anchors inside anchors, but we need the stub */
    908 	fprintf(stderr, "load anchor not supported from authpf\n");
    909 	return (1);
    910 }
    911 
    912 void
    913 pfctl_print_title(char *title)
    914 {
    915 }
    916