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inetd.c revision 1.121
      1 /*	$NetBSD: inetd.c,v 1.121 2012/12/13 19:38:40 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1998, 2003 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
      9  * NASA Ames Research Center and by Matthias Scheler.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     30  * POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 /*
     34  * Copyright (c) 1983, 1991, 1993, 1994
     35  *	The Regents of the University of California.  All rights reserved.
     36  *
     37  * Redistribution and use in source and binary forms, with or without
     38  * modification, are permitted provided that the following conditions
     39  * are met:
     40  * 1. Redistributions of source code must retain the above copyright
     41  *    notice, this list of conditions and the following disclaimer.
     42  * 2. Redistributions in binary form must reproduce the above copyright
     43  *    notice, this list of conditions and the following disclaimer in the
     44  *    documentation and/or other materials provided with the distribution.
     45  * 3. Neither the name of the University nor the names of its contributors
     46  *    may be used to endorse or promote products derived from this software
     47  *    without specific prior written permission.
     48  *
     49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     59  * SUCH DAMAGE.
     60  */
     61 
     62 #include <sys/cdefs.h>
     63 #ifndef lint
     64 __COPYRIGHT("@(#) Copyright (c) 1983, 1991, 1993, 1994\
     65  The Regents of the University of California.  All rights reserved.");
     66 #if 0
     67 static char sccsid[] = "@(#)inetd.c	8.4 (Berkeley) 4/13/94";
     68 #else
     69 __RCSID("$NetBSD: inetd.c,v 1.121 2012/12/13 19:38:40 christos Exp $");
     70 #endif
     71 #endif /* not lint */
     72 
     73 /*
     74  * Inetd - Internet super-server
     75  *
     76  * This program invokes all internet services as needed.  Connection-oriented
     77  * services are invoked each time a connection is made, by creating a process.
     78  * This process is passed the connection as file descriptor 0 and is expected
     79  * to do a getpeername to find out the source host and port.
     80  *
     81  * Datagram oriented services are invoked when a datagram
     82  * arrives; a process is created and passed a pending message
     83  * on file descriptor 0.  Datagram servers may either connect
     84  * to their peer, freeing up the original socket for inetd
     85  * to receive further messages on, or ``take over the socket'',
     86  * processing all arriving datagrams and, eventually, timing
     87  * out.	 The first type of server is said to be ``multi-threaded'';
     88  * the second type of server ``single-threaded''.
     89  *
     90  * Inetd uses a configuration file which is read at startup
     91  * and, possibly, at some later time in response to a hangup signal.
     92  * The configuration file is ``free format'' with fields given in the
     93  * order shown below.  Continuation lines for an entry must being with
     94  * a space or tab.  All fields must be present in each entry.
     95  *
     96  *	service name			must be in /etc/services or must
     97  *					name a tcpmux service
     98  *	socket type[:accf[,arg]]	stream/dgram/raw/rdm/seqpacket,
     99 					only stream can name an accept filter
    100  *	protocol			must be in /etc/protocols
    101  *	wait/nowait[:max]		single-threaded/multi-threaded, max #
    102  *	user[:group]			user/group to run daemon as
    103  *	server program			full path name
    104  *	server program arguments	maximum of MAXARGS (20)
    105  *
    106  * For RPC services
    107  *      service name/version            must be in /etc/rpc
    108  *	socket type			stream/dgram/raw/rdm/seqpacket
    109  *	protocol			must be in /etc/protocols
    110  *	wait/nowait[:max]		single-threaded/multi-threaded
    111  *	user[:group]			user to run daemon as
    112  *	server program			full path name
    113  *	server program arguments	maximum of MAXARGS (20)
    114  *
    115  * For non-RPC services, the "service name" can be of the form
    116  * hostaddress:servicename, in which case the hostaddress is used
    117  * as the host portion of the address to listen on.  If hostaddress
    118  * consists of a single `*' character, INADDR_ANY is used.
    119  *
    120  * A line can also consist of just
    121  *	hostaddress:
    122  * where hostaddress is as in the preceding paragraph.  Such a line must
    123  * have no further fields; the specified hostaddress is remembered and
    124  * used for all further lines that have no hostaddress specified,
    125  * until the next such line (or EOF).  (This is why * is provided to
    126  * allow explicit specification of INADDR_ANY.)  A line
    127  *	*:
    128  * is implicitly in effect at the beginning of the file.
    129  *
    130  * The hostaddress specifier may (and often will) contain dots;
    131  * the service name must not.
    132  *
    133  * For RPC services, host-address specifiers are accepted and will
    134  * work to some extent; however, because of limitations in the
    135  * portmapper interface, it will not work to try to give more than
    136  * one line for any given RPC service, even if the host-address
    137  * specifiers are different.
    138  *
    139  * TCP services without official port numbers are handled with the
    140  * RFC1078-based tcpmux internal service. Tcpmux listens on port 1 for
    141  * requests. When a connection is made from a foreign host, the service
    142  * requested is passed to tcpmux, which looks it up in the servtab list
    143  * and returns the proper entry for the service. Tcpmux returns a
    144  * negative reply if the service doesn't exist, otherwise the invoked
    145  * server is expected to return the positive reply if the service type in
    146  * inetd.conf file has the prefix "tcpmux/". If the service type has the
    147  * prefix "tcpmux/+", tcpmux will return the positive reply for the
    148  * process; this is for compatibility with older server code, and also
    149  * allows you to invoke programs that use stdin/stdout without putting any
    150  * special server code in them. Services that use tcpmux are "nowait"
    151  * because they do not have a well-known port and hence cannot listen
    152  * for new requests.
    153  *
    154  * Comment lines are indicated by a `#' in column 1.
    155  *
    156  * #ifdef IPSEC
    157  * Comment lines that start with "#@" denote IPsec policy string, as described
    158  * in ipsec_set_policy(3).  This will affect all the following items in
    159  * inetd.conf(8).  To reset the policy, just use "#@" line.  By default,
    160  * there's no IPsec policy.
    161  * #endif
    162  */
    163 
    164 /*
    165  * Here's the scoop concerning the user:group feature:
    166  *
    167  * 1) set-group-option off.
    168  *
    169  * 	a) user = root:	NO setuid() or setgid() is done
    170  *
    171  * 	b) other:	setuid()
    172  * 			setgid(primary group as found in passwd)
    173  * 			initgroups(name, primary group)
    174  *
    175  * 2) set-group-option on.
    176  *
    177  * 	a) user = root:	NO setuid()
    178  * 			setgid(specified group)
    179  * 			NO initgroups()
    180  *
    181  * 	b) other:	setuid()
    182  * 			setgid(specified group)
    183  * 			initgroups(name, specified group)
    184  *
    185  */
    186 
    187 #include <sys/param.h>
    188 #include <sys/stat.h>
    189 #include <sys/ioctl.h>
    190 #include <sys/socket.h>
    191 #include <sys/un.h>
    192 #include <sys/wait.h>
    193 #include <sys/time.h>
    194 #include <sys/resource.h>
    195 #include <sys/event.h>
    196 
    197 #ifndef NO_RPC
    198 #define RPC
    199 #endif
    200 
    201 #include <net/if.h>
    202 
    203 #include <netinet/in.h>
    204 #include <arpa/inet.h>
    205 #ifdef RPC
    206 #include <rpc/rpc.h>
    207 #include <rpc/rpcb_clnt.h>
    208 #include <netconfig.h>
    209 #endif
    210 
    211 #include <ctype.h>
    212 #include <errno.h>
    213 #include <fcntl.h>
    214 #include <grp.h>
    215 #include <netdb.h>
    216 #include <pwd.h>
    217 #include <signal.h>
    218 #include <stdio.h>
    219 #include <stdlib.h>
    220 #include <string.h>
    221 #include <syslog.h>
    222 #include <unistd.h>
    223 #include <util.h>
    224 #include <ifaddrs.h>
    225 
    226 #include "pathnames.h"
    227 
    228 #ifdef IPSEC
    229 #include <netipsec/ipsec.h>
    230 #ifndef IPSEC_POLICY_IPSEC	/* no ipsec support on old ipsec */
    231 #undef IPSEC
    232 #endif
    233 #include "ipsec.h"
    234 #endif
    235 
    236 #ifdef LIBWRAP
    237 # include <tcpd.h>
    238 #ifndef LIBWRAP_ALLOW_FACILITY
    239 # define LIBWRAP_ALLOW_FACILITY LOG_AUTH
    240 #endif
    241 #ifndef LIBWRAP_ALLOW_SEVERITY
    242 # define LIBWRAP_ALLOW_SEVERITY LOG_INFO
    243 #endif
    244 #ifndef LIBWRAP_DENY_FACILITY
    245 # define LIBWRAP_DENY_FACILITY LOG_AUTH
    246 #endif
    247 #ifndef LIBWRAP_DENY_SEVERITY
    248 # define LIBWRAP_DENY_SEVERITY LOG_WARNING
    249 #endif
    250 int allow_severity = LIBWRAP_ALLOW_FACILITY|LIBWRAP_ALLOW_SEVERITY;
    251 int deny_severity = LIBWRAP_DENY_FACILITY|LIBWRAP_DENY_SEVERITY;
    252 #endif
    253 
    254 #define	TOOMANY		40		/* don't start more than TOOMANY */
    255 #define	CNT_INTVL	60		/* servers in CNT_INTVL sec. */
    256 #define	RETRYTIME	(60*10)		/* retry after bind or server fail */
    257 
    258 #define	A_CNT(a)	(sizeof (a) / sizeof (a[0]))
    259 
    260 int	debug;
    261 #ifdef LIBWRAP
    262 int	lflag;
    263 #endif
    264 int	maxsock;
    265 int	kq;
    266 int	options;
    267 int	timingout;
    268 const int niflags = NI_NUMERICHOST | NI_NUMERICSERV;
    269 
    270 #ifndef OPEN_MAX
    271 #define OPEN_MAX	64
    272 #endif
    273 
    274 /* Reserve some descriptors, 3 stdio + at least: 1 log, 1 conf. file */
    275 #define FD_MARGIN	(8)
    276 rlim_t		rlim_ofile_cur = OPEN_MAX;
    277 
    278 struct rlimit	rlim_ofile;
    279 
    280 struct kevent	changebuf[64];
    281 size_t		changes;
    282 
    283 struct	servtab {
    284 	char	*se_hostaddr;		/* host address to listen on */
    285 	char	*se_service;		/* name of service */
    286 	int	se_socktype;		/* type of socket to use */
    287 	int	se_family;		/* address family */
    288 	char	*se_proto;		/* protocol used */
    289 	int	se_sndbuf;		/* sndbuf size */
    290 	int	se_rcvbuf;		/* rcvbuf size */
    291 	int	se_rpcprog;		/* rpc program number */
    292 	int	se_rpcversl;		/* rpc program lowest version */
    293 	int	se_rpcversh;		/* rpc program highest version */
    294 #define isrpcservice(sep)	((sep)->se_rpcversl != 0)
    295 	pid_t	se_wait;		/* single threaded server */
    296 	short	se_checked;		/* looked at during merge */
    297 	char	*se_user;		/* user name to run as */
    298 	char	*se_group;		/* group name to run as */
    299 	struct	biltin *se_bi;		/* if built-in, description */
    300 	char	*se_server;		/* server program */
    301 #define	MAXARGV 20
    302 	char	*se_argv[MAXARGV+1];	/* program arguments */
    303 #ifdef IPSEC
    304 	char	*se_policy;		/* IPsec poilcy string */
    305 #endif
    306 	struct accept_filter_arg se_accf; /* accept filter for stream service */
    307 	int	se_fd;			/* open descriptor */
    308 	int	se_type;		/* type */
    309 	union {
    310 		struct	sockaddr se_un_ctrladdr;
    311 		struct	sockaddr_in se_un_ctrladdr_in;
    312 		struct	sockaddr_in6 se_un_ctrladdr_in6;
    313 		struct	sockaddr_un se_un_ctrladdr_un;
    314 	} se_un;			/* bound address */
    315 #define se_ctrladdr	se_un.se_un_ctrladdr
    316 #define se_ctrladdr_in	se_un.se_un_ctrladdr_in
    317 #define se_ctrladdr_un	se_un.se_un_ctrladdr_un
    318 	int	se_ctrladdr_size;
    319 	int	se_max;			/* max # of instances of this service */
    320 	int	se_count;		/* number started since se_time */
    321 	struct	timeval se_time;	/* start of se_count */
    322 	struct	servtab *se_next;
    323 } *servtab;
    324 
    325 #define NORM_TYPE	0
    326 #define MUX_TYPE	1
    327 #define MUXPLUS_TYPE	2
    328 #define FAITH_TYPE	3
    329 #define ISMUX(sep)	(((sep)->se_type == MUX_TYPE) || \
    330 			 ((sep)->se_type == MUXPLUS_TYPE))
    331 #define ISMUXPLUS(sep)	((sep)->se_type == MUXPLUS_TYPE)
    332 
    333 
    334 static void	chargen_dg(int, struct servtab *);
    335 static void	chargen_stream(int, struct servtab *);
    336 static void	close_sep(struct servtab *);
    337 static void	config(void);
    338 static void	daytime_dg(int, struct servtab *);
    339 static void	daytime_stream(int, struct servtab *);
    340 static void	discard_dg(int, struct servtab *);
    341 static void	discard_stream(int, struct servtab *);
    342 static void	echo_dg(int, struct servtab *);
    343 static void	echo_stream(int, struct servtab *);
    344 static void	endconfig(void);
    345 static struct servtab *enter(struct servtab *);
    346 static void	freeconfig(struct servtab *);
    347 static struct servtab *getconfigent(void);
    348 __dead static void	goaway(void);
    349 static void	machtime_dg(int, struct servtab *);
    350 static void	machtime_stream(int, struct servtab *);
    351 static char    *newstr(const char *);
    352 static char    *nextline(FILE *);
    353 static void	print_service(const char *, struct servtab *);
    354 static void	reapchild(void);
    355 static void	retry(void);
    356 static void	run_service(int, struct servtab *, int);
    357 static int	setconfig(void);
    358 static void	setup(struct servtab *);
    359 static char    *sskip(char **);
    360 static char    *skip(char **);
    361 static void	tcpmux(int, struct servtab *);
    362 __dead static void	usage(void);
    363 static void	register_rpc(struct servtab *);
    364 static void	unregister_rpc(struct servtab *);
    365 static void	bump_nofile(void);
    366 static void	inetd_setproctitle(char *, int);
    367 static void	initring(void);
    368 static uint32_t	machtime(void);
    369 static int	port_good_dg(struct sockaddr *);
    370 static int 	dg_broadcast(struct in_addr *);
    371 static int	my_kevent(const struct kevent *, size_t, struct kevent *,
    372 		size_t);
    373 static struct kevent *	allocchange(void);
    374 static int	get_line(int, char *, int);
    375 static void	spawn(struct servtab *, int);
    376 
    377 struct biltin {
    378 	const char *bi_service;		/* internally provided service name */
    379 	int	bi_socktype;		/* type of socket supported */
    380 	short	bi_fork;		/* 1 if should fork before call */
    381 	short	bi_wait;		/* 1 if should wait for child */
    382 	void	(*bi_fn)(int, struct servtab *);
    383 					/* function which performs it */
    384 } biltins[] = {
    385 	/* Echo received data */
    386 	{ "echo",	SOCK_STREAM,	1, 0,	echo_stream },
    387 	{ "echo",	SOCK_DGRAM,	0, 0,	echo_dg },
    388 
    389 	/* Internet /dev/null */
    390 	{ "discard",	SOCK_STREAM,	1, 0,	discard_stream },
    391 	{ "discard",	SOCK_DGRAM,	0, 0,	discard_dg },
    392 
    393 	/* Return 32 bit time since 1970 */
    394 	{ "time",	SOCK_STREAM,	0, 0,	machtime_stream },
    395 	{ "time",	SOCK_DGRAM,	0, 0,	machtime_dg },
    396 
    397 	/* Return human-readable time */
    398 	{ "daytime",	SOCK_STREAM,	0, 0,	daytime_stream },
    399 	{ "daytime",	SOCK_DGRAM,	0, 0,	daytime_dg },
    400 
    401 	/* Familiar character generator */
    402 	{ "chargen",	SOCK_STREAM,	1, 0,	chargen_stream },
    403 	{ "chargen",	SOCK_DGRAM,	0, 0,	chargen_dg },
    404 
    405 	{ "tcpmux",	SOCK_STREAM,	1, 0,	tcpmux },
    406 
    407 	{ NULL, 0, 0, 0, NULL }
    408 };
    409 
    410 /* list of "bad" ports. I.e. ports that are most obviously used for
    411  * "cycling packets" denial of service attacks. See /etc/services.
    412  * List must end with port number "0".
    413  */
    414 
    415 u_int16_t bad_ports[] =  { 7, 9, 13, 19, 37, 0 };
    416 
    417 
    418 #define NUMINT	(sizeof(intab) / sizeof(struct inent))
    419 const char	*CONFIG = _PATH_INETDCONF;
    420 
    421 static int my_signals[] =
    422     { SIGALRM, SIGHUP, SIGCHLD, SIGTERM, SIGINT, SIGPIPE };
    423 
    424 int
    425 main(int argc, char *argv[])
    426 {
    427 	int		ch, n, reload = 1;
    428 
    429 	while ((ch = getopt(argc, argv,
    430 #ifdef LIBWRAP
    431 					"dl"
    432 #else
    433 					"d"
    434 #endif
    435 					   )) != -1)
    436 		switch(ch) {
    437 		case 'd':
    438 			debug = 1;
    439 			options |= SO_DEBUG;
    440 			break;
    441 #ifdef LIBWRAP
    442 		case 'l':
    443 			lflag = 1;
    444 			break;
    445 #endif
    446 		case '?':
    447 		default:
    448 			usage();
    449 		}
    450 	argc -= optind;
    451 	argv += optind;
    452 
    453 	if (argc > 0)
    454 		CONFIG = argv[0];
    455 
    456 	if (!debug)
    457 		daemon(0, 0);
    458 	openlog("inetd", LOG_PID | LOG_NOWAIT, LOG_DAEMON);
    459 	pidfile(NULL);
    460 
    461 	kq = kqueue();
    462 	if (kq < 0) {
    463 		syslog(LOG_ERR, "kqueue: %m");
    464 		return (EXIT_FAILURE);
    465 	}
    466 
    467 	if (getrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0) {
    468 		syslog(LOG_ERR, "getrlimit: %m");
    469 	} else {
    470 		rlim_ofile_cur = rlim_ofile.rlim_cur;
    471 		if (rlim_ofile_cur == RLIM_INFINITY)	/* ! */
    472 			rlim_ofile_cur = OPEN_MAX;
    473 	}
    474 
    475 	for (n = 0; n < (int)A_CNT(my_signals); n++) {
    476 		int	signum;
    477 
    478 		signum = my_signals[n];
    479 		if (signum != SIGCHLD)
    480 			(void) signal(signum, SIG_IGN);
    481 
    482 		if (signum != SIGPIPE) {
    483 			struct kevent	*ev;
    484 
    485 			ev = allocchange();
    486 			EV_SET(ev, signum, EVFILT_SIGNAL, EV_ADD | EV_ENABLE,
    487 			    0, 0, 0);
    488 		}
    489 	}
    490 
    491 	for (;;) {
    492 		int		ctrl;
    493 		struct kevent	eventbuf[64], *ev;
    494 		struct servtab	*sep;
    495 
    496 		if (reload) {
    497 			reload = 0;
    498 			config();
    499 		}
    500 
    501 		n = my_kevent(changebuf, changes, eventbuf, A_CNT(eventbuf));
    502 		changes = 0;
    503 
    504 		for (ev = eventbuf; n > 0; ev++, n--) {
    505 			if (ev->filter == EVFILT_SIGNAL) {
    506 				switch (ev->ident) {
    507 				case SIGALRM:
    508 					retry();
    509 					break;
    510 				case SIGCHLD:
    511 					reapchild();
    512 					break;
    513 				case SIGTERM:
    514 				case SIGINT:
    515 					goaway();
    516 					break;
    517 				case SIGHUP:
    518 					reload = 1;
    519 					break;
    520 				}
    521 				continue;
    522 			}
    523 			if (ev->filter != EVFILT_READ)
    524 				continue;
    525 			sep = (struct servtab *)ev->udata;
    526 			/* Paranoia */
    527 			if ((int)ev->ident != sep->se_fd)
    528 				continue;
    529 			if (debug)
    530 				fprintf(stderr, "someone wants %s\n",
    531 				    sep->se_service);
    532 			if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) {
    533 				/* XXX here do the libwrap check-before-accept*/
    534 				ctrl = accept(sep->se_fd, NULL, NULL);
    535 				if (debug)
    536 					fprintf(stderr, "accept, ctrl %d\n",
    537 					    ctrl);
    538 				if (ctrl < 0) {
    539 					if (errno != EINTR)
    540 						syslog(LOG_WARNING,
    541 						    "accept (for %s): %m",
    542 						    sep->se_service);
    543 					continue;
    544 				}
    545 			} else
    546 				ctrl = sep->se_fd;
    547 			spawn(sep, ctrl);
    548 		}
    549 	}
    550 }
    551 
    552 static void
    553 spawn(struct servtab *sep, int ctrl)
    554 {
    555 	int dofork;
    556 	pid_t pid;
    557 
    558 	pid = 0;
    559 #ifdef LIBWRAP_INTERNAL
    560 	dofork = 1;
    561 #else
    562 	dofork = (sep->se_bi == 0 || sep->se_bi->bi_fork);
    563 #endif
    564 	if (dofork) {
    565 		if (sep->se_count++ == 0)
    566 			(void)gettimeofday(&sep->se_time, NULL);
    567 		else if (sep->se_count >= sep->se_max) {
    568 			struct timeval now;
    569 
    570 			(void)gettimeofday(&now, NULL);
    571 			if (now.tv_sec - sep->se_time.tv_sec > CNT_INTVL) {
    572 				sep->se_time = now;
    573 				sep->se_count = 1;
    574 			} else {
    575 				syslog(LOG_ERR,
    576 				    "%s/%s max spawn rate (%d in %d seconds) "
    577 				    "exceeded; service not started",
    578 				    sep->se_service, sep->se_proto,
    579 				    sep->se_max, CNT_INTVL);
    580 				if (!sep->se_wait && sep->se_socktype ==
    581 				    SOCK_STREAM)
    582 					close(ctrl);
    583 				close_sep(sep);
    584 				if (!timingout) {
    585 					timingout = 1;
    586 					alarm(RETRYTIME);
    587 				}
    588 				return;
    589 			}
    590 		}
    591 		pid = fork();
    592 		if (pid < 0) {
    593 			syslog(LOG_ERR, "fork: %m");
    594 			if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
    595 				close(ctrl);
    596 			sleep(1);
    597 			return;
    598 		}
    599 		if (pid != 0 && sep->se_wait) {
    600 			struct kevent	*ev;
    601 
    602 			sep->se_wait = pid;
    603 			ev = allocchange();
    604 			EV_SET(ev, sep->se_fd, EVFILT_READ,
    605 			    EV_DELETE, 0, 0, 0);
    606 		}
    607 		if (pid == 0) {
    608 			size_t	n;
    609 
    610 			for (n = 0; n < A_CNT(my_signals); n++)
    611 				(void) signal(my_signals[n], SIG_DFL);
    612 			if (debug)
    613 				setsid();
    614 		}
    615 	}
    616 	if (pid == 0) {
    617 		run_service(ctrl, sep, dofork);
    618 		if (dofork)
    619 			exit(0);
    620 	}
    621 	if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
    622 		close(ctrl);
    623 }
    624 
    625 static void
    626 run_service(int ctrl, struct servtab *sep, int didfork)
    627 {
    628 	struct passwd *pwd;
    629 	struct group *grp = NULL;	/* XXX gcc */
    630 	char buf[NI_MAXSERV];
    631 	struct servtab *s;
    632 #ifdef LIBWRAP
    633 	char abuf[BUFSIZ];
    634 	struct request_info req;
    635 	int denied;
    636 	char *service = NULL;	/* XXX gcc */
    637 #endif
    638 
    639 #ifdef LIBWRAP
    640 #ifndef LIBWRAP_INTERNAL
    641 	if (sep->se_bi == 0)
    642 #endif
    643 	if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) {
    644 		request_init(&req, RQ_DAEMON, sep->se_argv[0] ?
    645 		    sep->se_argv[0] : sep->se_service, RQ_FILE, ctrl, NULL);
    646 		fromhost(&req);
    647 		denied = !hosts_access(&req);
    648 		if (denied || lflag) {
    649 			if (getnameinfo(&sep->se_ctrladdr,
    650 			    (socklen_t)sep->se_ctrladdr.sa_len, NULL, 0,
    651 			    buf, sizeof(buf), 0) != 0) {
    652 				/* shouldn't happen */
    653 				(void)snprintf(buf, sizeof buf, "%d",
    654 				    ntohs(sep->se_ctrladdr_in.sin_port));
    655 			}
    656 			service = buf;
    657 			if (req.client->sin) {
    658 				sockaddr_snprintf(abuf, sizeof(abuf), "%a",
    659 				    req.client->sin);
    660 			} else {
    661 				strcpy(abuf, "(null)");
    662 			}
    663 		}
    664 		if (denied) {
    665 			syslog(deny_severity,
    666 			    "refused connection from %.500s(%s), service %s (%s)",
    667 			    eval_client(&req), abuf, service, sep->se_proto);
    668 			goto reject;
    669 		}
    670 		if (lflag) {
    671 			syslog(allow_severity,
    672 			    "connection from %.500s(%s), service %s (%s)",
    673 			    eval_client(&req), abuf, service, sep->se_proto);
    674 		}
    675 	}
    676 #endif /* LIBWRAP */
    677 
    678 	if (sep->se_bi) {
    679 		if (didfork) {
    680 			for (s = servtab; s; s = s->se_next)
    681 				if (s->se_fd != -1 && s->se_fd != ctrl) {
    682 					close(s->se_fd);
    683 					s->se_fd = -1;
    684 				}
    685 		}
    686 		(*sep->se_bi->bi_fn)(ctrl, sep);
    687 	} else {
    688 		if ((pwd = getpwnam(sep->se_user)) == NULL) {
    689 			syslog(LOG_ERR, "%s/%s: %s: No such user",
    690 			    sep->se_service, sep->se_proto, sep->se_user);
    691 			goto reject;
    692 		}
    693 		if (sep->se_group &&
    694 		    (grp = getgrnam(sep->se_group)) == NULL) {
    695 			syslog(LOG_ERR, "%s/%s: %s: No such group",
    696 			    sep->se_service, sep->se_proto, sep->se_group);
    697 			goto reject;
    698 		}
    699 		if (pwd->pw_uid) {
    700 			if (sep->se_group)
    701 				pwd->pw_gid = grp->gr_gid;
    702 			if (setgid(pwd->pw_gid) < 0) {
    703 				syslog(LOG_ERR,
    704 				 "%s/%s: can't set gid %d: %m", sep->se_service,
    705 				    sep->se_proto, pwd->pw_gid);
    706 				goto reject;
    707 			}
    708 			(void) initgroups(pwd->pw_name,
    709 			    pwd->pw_gid);
    710 			if (setuid(pwd->pw_uid) < 0) {
    711 				syslog(LOG_ERR,
    712 				 "%s/%s: can't set uid %d: %m", sep->se_service,
    713 				    sep->se_proto, pwd->pw_uid);
    714 				goto reject;
    715 			}
    716 		} else if (sep->se_group) {
    717 			(void) setgid((gid_t)grp->gr_gid);
    718 		}
    719 		if (debug)
    720 			fprintf(stderr, "%d execl %s\n",
    721 			    getpid(), sep->se_server);
    722 		/* Set our control descriptor to not close-on-exec... */
    723 		if (fcntl(ctrl, F_SETFD, 0) < 0)
    724 			syslog(LOG_ERR, "fcntl (%d, F_SETFD, 0): %m", ctrl);
    725 		/* ...and dup it to stdin, stdout, and stderr. */
    726 		if (ctrl != 0) {
    727 			dup2(ctrl, 0);
    728 			close(ctrl);
    729 			ctrl = 0;
    730 		}
    731 		dup2(0, 1);
    732 		dup2(0, 2);
    733 		if (rlim_ofile.rlim_cur != rlim_ofile_cur &&
    734 		    setrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0)
    735 			syslog(LOG_ERR, "setrlimit: %m");
    736 		execv(sep->se_server, sep->se_argv);
    737 		syslog(LOG_ERR, "cannot execute %s: %m", sep->se_server);
    738 	reject:
    739 		if (sep->se_socktype != SOCK_STREAM)
    740 			recv(ctrl, buf, sizeof (buf), 0);
    741 		_exit(1);
    742 	}
    743 }
    744 
    745 static void
    746 reapchild(void)
    747 {
    748 	int status;
    749 	pid_t pid;
    750 	struct servtab *sep;
    751 
    752 	for (;;) {
    753 		pid = wait3(&status, WNOHANG, NULL);
    754 		if (pid <= 0)
    755 			break;
    756 		if (debug)
    757 			(void) fprintf(stderr, "%d reaped, status %#x\n",
    758 			    pid, status);
    759 		for (sep = servtab; sep != NULL; sep = sep->se_next)
    760 			if (sep->se_wait == pid) {
    761 				struct kevent	*ev;
    762 
    763 				if (WIFEXITED(status) && WEXITSTATUS(status))
    764 					syslog(LOG_WARNING,
    765 					    "%s: exit status 0x%x",
    766 					    sep->se_server, WEXITSTATUS(status));
    767 				else if (WIFSIGNALED(status))
    768 					syslog(LOG_WARNING,
    769 					    "%s: exit signal 0x%x",
    770 					    sep->se_server, WTERMSIG(status));
    771 				sep->se_wait = 1;
    772 				ev = allocchange();
    773 				EV_SET(ev, sep->se_fd, EVFILT_READ,
    774 				    EV_ADD | EV_ENABLE, 0, 0, (intptr_t)sep);
    775 				if (debug)
    776 					fprintf(stderr, "restored %s, fd %d\n",
    777 					    sep->se_service, sep->se_fd);
    778 			}
    779 	}
    780 }
    781 
    782 static void
    783 config(void)
    784 {
    785 	struct servtab *sep, *cp, **sepp;
    786 	size_t n;
    787 
    788 	if (!setconfig()) {
    789 		syslog(LOG_ERR, "%s: %m", CONFIG);
    790 		return;
    791 	}
    792 	for (sep = servtab; sep != NULL; sep = sep->se_next)
    793 		sep->se_checked = 0;
    794 	while ((cp = getconfigent()) != NULL) {
    795 		for (sep = servtab; sep != NULL; sep = sep->se_next)
    796 			if (strcmp(sep->se_service, cp->se_service) == 0 &&
    797 			    strcmp(sep->se_hostaddr, cp->se_hostaddr) == 0 &&
    798 			    strcmp(sep->se_proto, cp->se_proto) == 0 &&
    799 			    ISMUX(sep) == ISMUX(cp))
    800 				break;
    801 		if (sep != NULL) {
    802 			int i;
    803 
    804 #define SWAP(type, a, b) {type c = a; a = b; b = c;}
    805 
    806 			/*
    807 			 * sep->se_wait may be holding the pid of a daemon
    808 			 * that we're waiting for.  If so, don't overwrite
    809 			 * it unless the config file explicitly says don't
    810 			 * wait.
    811 			 */
    812 			if (cp->se_bi == 0 &&
    813 			    (sep->se_wait == 1 || cp->se_wait == 0))
    814 				sep->se_wait = cp->se_wait;
    815 			SWAP(char *, sep->se_user, cp->se_user);
    816 			SWAP(char *, sep->se_group, cp->se_group);
    817 			SWAP(char *, sep->se_server, cp->se_server);
    818 			for (i = 0; i < MAXARGV; i++)
    819 				SWAP(char *, sep->se_argv[i], cp->se_argv[i]);
    820 #ifdef IPSEC
    821 			SWAP(char *, sep->se_policy, cp->se_policy);
    822 #endif
    823 			SWAP(int, cp->se_type, sep->se_type);
    824 			SWAP(int, cp->se_max, sep->se_max);
    825 #undef SWAP
    826 			if (isrpcservice(sep))
    827 				unregister_rpc(sep);
    828 			sep->se_rpcversl = cp->se_rpcversl;
    829 			sep->se_rpcversh = cp->se_rpcversh;
    830 			freeconfig(cp);
    831 			if (debug)
    832 				print_service("REDO", sep);
    833 		} else {
    834 			sep = enter(cp);
    835 			if (debug)
    836 				print_service("ADD ", sep);
    837 		}
    838 		sep->se_checked = 1;
    839 
    840 		switch (sep->se_family) {
    841 		case AF_LOCAL:
    842 			if (sep->se_fd != -1)
    843 				break;
    844 			n = strlen(sep->se_service);
    845 			if (n >= sizeof(sep->se_ctrladdr_un.sun_path)) {
    846 				syslog(LOG_ERR, "%s: address too long",
    847 				    sep->se_service);
    848 				sep->se_checked = 0;
    849 				continue;
    850 			}
    851 			(void)unlink(sep->se_service);
    852 			strlcpy(sep->se_ctrladdr_un.sun_path,
    853 			    sep->se_service, n);
    854 			sep->se_ctrladdr_un.sun_family = AF_LOCAL;
    855 			sep->se_ctrladdr_size = (int)(n +
    856 			    sizeof(sep->se_ctrladdr_un) -
    857 			    sizeof(sep->se_ctrladdr_un.sun_path));
    858 			if (!ISMUX(sep))
    859 				setup(sep);
    860 			break;
    861 		case AF_INET:
    862 #ifdef INET6
    863 		case AF_INET6:
    864 #endif
    865 		    {
    866 			struct addrinfo hints, *res;
    867 			char *host;
    868 			const char *port;
    869 			int error;
    870 			int s;
    871 
    872 			/* check if the family is supported */
    873 			s = socket(sep->se_family, SOCK_DGRAM, 0);
    874 			if (s < 0) {
    875 				syslog(LOG_WARNING,
    876 				    "%s/%s: %s: the address family is not "
    877 				    "supported by the kernel",
    878 				    sep->se_service, sep->se_proto,
    879 				    sep->se_hostaddr);
    880 				sep->se_checked = 0;
    881 				continue;
    882 			}
    883 			close(s);
    884 
    885 			memset(&hints, 0, sizeof(hints));
    886 			hints.ai_family = sep->se_family;
    887 			hints.ai_socktype = sep->se_socktype;
    888 			hints.ai_flags = AI_PASSIVE;
    889 			if (!strcmp(sep->se_hostaddr, "*"))
    890 				host = NULL;
    891 			else
    892 				host = sep->se_hostaddr;
    893 			if (isrpcservice(sep) || ISMUX(sep))
    894 				port = "0";
    895 			else
    896 				port = sep->se_service;
    897 			error = getaddrinfo(host, port, &hints, &res);
    898 			if (error) {
    899 				if (error == EAI_SERVICE) {
    900 					/* gai_strerror not friendly enough */
    901 					syslog(LOG_WARNING, "%s/%s: "
    902 					    "unknown service",
    903 					    sep->se_service, sep->se_proto);
    904 				} else {
    905 					syslog(LOG_ERR, "%s/%s: %s: %s",
    906 					    sep->se_service, sep->se_proto,
    907 					    sep->se_hostaddr,
    908 					    gai_strerror(error));
    909 				}
    910 				sep->se_checked = 0;
    911 				continue;
    912 			}
    913 			if (res->ai_next) {
    914 				syslog(LOG_ERR,
    915 					"%s/%s: %s: resolved to multiple addr",
    916 				    sep->se_service, sep->se_proto,
    917 				    sep->se_hostaddr);
    918 				sep->se_checked = 0;
    919 				freeaddrinfo(res);
    920 				continue;
    921 			}
    922 			memcpy(&sep->se_ctrladdr, res->ai_addr,
    923 				res->ai_addrlen);
    924 			if (ISMUX(sep)) {
    925 				sep->se_fd = -1;
    926 				freeaddrinfo(res);
    927 				continue;
    928 			}
    929 			sep->se_ctrladdr_size = res->ai_addrlen;
    930 			freeaddrinfo(res);
    931 #ifdef RPC
    932 			if (isrpcservice(sep)) {
    933 				struct rpcent *rp;
    934 
    935 				sep->se_rpcprog = atoi(sep->se_service);
    936 				if (sep->se_rpcprog == 0) {
    937 					rp = getrpcbyname(sep->se_service);
    938 					if (rp == 0) {
    939 						syslog(LOG_ERR,
    940 						    "%s/%s: unknown service",
    941 						    sep->se_service,
    942 						    sep->se_proto);
    943 						sep->se_checked = 0;
    944 						continue;
    945 					}
    946 					sep->se_rpcprog = rp->r_number;
    947 				}
    948 				if (sep->se_fd == -1 && !ISMUX(sep))
    949 					setup(sep);
    950 				if (sep->se_fd != -1)
    951 					register_rpc(sep);
    952 			} else
    953 #endif
    954 			{
    955 				if (sep->se_fd >= 0)
    956 					close_sep(sep);
    957 				if (sep->se_fd == -1 && !ISMUX(sep))
    958 					setup(sep);
    959 			}
    960 		    }
    961 		}
    962 	}
    963 	endconfig();
    964 	/*
    965 	 * Purge anything not looked at above.
    966 	 */
    967 	sepp = &servtab;
    968 	while ((sep = *sepp) != NULL) {
    969 		if (sep->se_checked) {
    970 			sepp = &sep->se_next;
    971 			continue;
    972 		}
    973 		*sepp = sep->se_next;
    974 		if (sep->se_fd >= 0)
    975 			close_sep(sep);
    976 		if (isrpcservice(sep))
    977 			unregister_rpc(sep);
    978 		if (sep->se_family == AF_LOCAL)
    979 			(void)unlink(sep->se_service);
    980 		if (debug)
    981 			print_service("FREE", sep);
    982 		freeconfig(sep);
    983 		free(sep);
    984 	}
    985 }
    986 
    987 static void
    988 retry(void)
    989 {
    990 	struct servtab *sep;
    991 
    992 	timingout = 0;
    993 	for (sep = servtab; sep != NULL; sep = sep->se_next) {
    994 		if (sep->se_fd == -1 && !ISMUX(sep)) {
    995 			switch (sep->se_family) {
    996 			case AF_LOCAL:
    997 			case AF_INET:
    998 #ifdef INET6
    999 			case AF_INET6:
   1000 #endif
   1001 				setup(sep);
   1002 				if (sep->se_fd >= 0 && isrpcservice(sep))
   1003 					register_rpc(sep);
   1004 				break;
   1005 			}
   1006 		}
   1007 	}
   1008 }
   1009 
   1010 static void
   1011 goaway(void)
   1012 {
   1013 	struct servtab *sep;
   1014 
   1015 	for (sep = servtab; sep != NULL; sep = sep->se_next) {
   1016 		if (sep->se_fd == -1)
   1017 			continue;
   1018 
   1019 		switch (sep->se_family) {
   1020 		case AF_LOCAL:
   1021 			(void)unlink(sep->se_service);
   1022 			break;
   1023 		case AF_INET:
   1024 #ifdef INET6
   1025 		case AF_INET6:
   1026 #endif
   1027 			if (sep->se_wait == 1 && isrpcservice(sep))
   1028 				unregister_rpc(sep);
   1029 			break;
   1030 		}
   1031 		(void)close(sep->se_fd);
   1032 		sep->se_fd = -1;
   1033 	}
   1034 	exit(0);
   1035 }
   1036 
   1037 static void
   1038 setup(struct servtab *sep)
   1039 {
   1040 	int		on = 1;
   1041 #ifdef INET6
   1042 	int		off = 0;
   1043 #endif
   1044 	struct kevent	*ev;
   1045 
   1046 	if ((sep->se_fd = socket(sep->se_family, sep->se_socktype, 0)) < 0) {
   1047 		if (debug)
   1048 			fprintf(stderr, "socket failed on %s/%s: %s\n",
   1049 			    sep->se_service, sep->se_proto, strerror(errno));
   1050 		syslog(LOG_ERR, "%s/%s: socket: %m",
   1051 		    sep->se_service, sep->se_proto);
   1052 		return;
   1053 	}
   1054 	/* Set all listening sockets to close-on-exec. */
   1055 	if (fcntl(sep->se_fd, F_SETFD, FD_CLOEXEC) < 0) {
   1056 		syslog(LOG_ERR, "%s/%s: fcntl(F_SETFD, FD_CLOEXEC): %m",
   1057 		    sep->se_service, sep->se_proto);
   1058 		close(sep->se_fd);
   1059 		sep->se_fd = -1;
   1060 		return;
   1061 	}
   1062 
   1063 #define	turnon(fd, opt) \
   1064 setsockopt(fd, SOL_SOCKET, opt, &on, (socklen_t)sizeof(on))
   1065 	if (strcmp(sep->se_proto, "tcp") == 0 && (options & SO_DEBUG) &&
   1066 	    turnon(sep->se_fd, SO_DEBUG) < 0)
   1067 		syslog(LOG_ERR, "setsockopt (SO_DEBUG): %m");
   1068 	if (turnon(sep->se_fd, SO_REUSEADDR) < 0)
   1069 		syslog(LOG_ERR, "setsockopt (SO_REUSEADDR): %m");
   1070 #undef turnon
   1071 
   1072 	/* Set the socket buffer sizes, if specified. */
   1073 	if (sep->se_sndbuf != 0 && setsockopt(sep->se_fd, SOL_SOCKET,
   1074 	    SO_SNDBUF, &sep->se_sndbuf, (socklen_t)sizeof(sep->se_sndbuf)) < 0)
   1075 		syslog(LOG_ERR, "setsockopt (SO_SNDBUF %d): %m",
   1076 		    sep->se_sndbuf);
   1077 	if (sep->se_rcvbuf != 0 && setsockopt(sep->se_fd, SOL_SOCKET,
   1078 	    SO_RCVBUF, &sep->se_rcvbuf, (socklen_t)sizeof(sep->se_rcvbuf)) < 0)
   1079 		syslog(LOG_ERR, "setsockopt (SO_RCVBUF %d): %m",
   1080 		    sep->se_rcvbuf);
   1081 #ifdef INET6
   1082 	if (sep->se_family == AF_INET6) {
   1083 		int *v;
   1084 		v = (sep->se_type == FAITH_TYPE) ? &on : &off;
   1085 		if (setsockopt(sep->se_fd, IPPROTO_IPV6, IPV6_FAITH,
   1086 		    v, (socklen_t)sizeof(*v)) < 0)
   1087 			syslog(LOG_ERR, "setsockopt (IPV6_FAITH): %m");
   1088 	}
   1089 #endif
   1090 #ifdef IPSEC
   1091 	if (ipsecsetup(sep->se_family, sep->se_fd, sep->se_policy) < 0 &&
   1092 	    sep->se_policy) {
   1093 		syslog(LOG_ERR, "%s/%s: ipsec setup failed",
   1094 		    sep->se_service, sep->se_proto);
   1095 		(void)close(sep->se_fd);
   1096 		sep->se_fd = -1;
   1097 		return;
   1098 	}
   1099 #endif
   1100 
   1101 	if (bind(sep->se_fd, &sep->se_ctrladdr,
   1102 	    (socklen_t)sep->se_ctrladdr_size) < 0) {
   1103 		if (debug)
   1104 			fprintf(stderr, "bind failed on %s/%s: %s\n",
   1105 			    sep->se_service, sep->se_proto, strerror(errno));
   1106 		syslog(LOG_ERR, "%s/%s: bind: %m",
   1107 		    sep->se_service, sep->se_proto);
   1108 		(void) close(sep->se_fd);
   1109 		sep->se_fd = -1;
   1110 		if (!timingout) {
   1111 			timingout = 1;
   1112 			alarm(RETRYTIME);
   1113 		}
   1114 		return;
   1115 	}
   1116 	if (sep->se_socktype == SOCK_STREAM)
   1117 		listen(sep->se_fd, 10);
   1118 
   1119 	/* Set the accept filter, if specified. To be done after listen.*/
   1120 	if (sep->se_accf.af_name[0] != 0 && setsockopt(sep->se_fd, SOL_SOCKET,
   1121 	    SO_ACCEPTFILTER, &sep->se_accf,
   1122 	    (socklen_t)sizeof(sep->se_accf)) < 0)
   1123 		syslog(LOG_ERR, "setsockopt(SO_ACCEPTFILTER %s): %m",
   1124 		    sep->se_accf.af_name);
   1125 
   1126 	ev = allocchange();
   1127 	EV_SET(ev, sep->se_fd, EVFILT_READ, EV_ADD | EV_ENABLE, 0, 0,
   1128 	    (intptr_t)sep);
   1129 	if (sep->se_fd > maxsock) {
   1130 		maxsock = sep->se_fd;
   1131 		if (maxsock > (int)(rlim_ofile_cur - FD_MARGIN))
   1132 			bump_nofile();
   1133 	}
   1134 	if (debug)
   1135 		fprintf(stderr, "registered %s on %d\n",
   1136 		    sep->se_server, sep->se_fd);
   1137 }
   1138 
   1139 /*
   1140  * Finish with a service and its socket.
   1141  */
   1142 static void
   1143 close_sep(struct servtab *sep)
   1144 {
   1145 	if (sep->se_fd >= 0) {
   1146 		(void) close(sep->se_fd);
   1147 		sep->se_fd = -1;
   1148 	}
   1149 	sep->se_count = 0;
   1150 }
   1151 
   1152 static void
   1153 register_rpc(struct servtab *sep)
   1154 {
   1155 #ifdef RPC
   1156 	struct netbuf nbuf;
   1157 	struct sockaddr_storage ss;
   1158 	struct netconfig *nconf;
   1159 	socklen_t socklen;
   1160 	int n;
   1161 
   1162 	if ((nconf = getnetconfigent(sep->se_proto+4)) == NULL) {
   1163 		syslog(LOG_ERR, "%s: getnetconfigent failed",
   1164 		    sep->se_proto);
   1165 		return;
   1166 	}
   1167 	socklen = sizeof ss;
   1168 	if (getsockname(sep->se_fd, (struct sockaddr *)(void *)&ss, &socklen) < 0) {
   1169 		syslog(LOG_ERR, "%s/%s: getsockname: %m",
   1170 		    sep->se_service, sep->se_proto);
   1171 		return;
   1172 	}
   1173 
   1174 	nbuf.buf = &ss;
   1175 	nbuf.len = ss.ss_len;
   1176 	nbuf.maxlen = sizeof (struct sockaddr_storage);
   1177 	for (n = sep->se_rpcversl; n <= sep->se_rpcversh; n++) {
   1178 		if (debug)
   1179 			fprintf(stderr, "rpcb_set: %u %d %s %s\n",
   1180 			    sep->se_rpcprog, n, nconf->nc_netid,
   1181 			    taddr2uaddr(nconf, &nbuf));
   1182 		(void)rpcb_unset((unsigned int)sep->se_rpcprog, (unsigned int)n, nconf);
   1183 		if (!rpcb_set((unsigned int)sep->se_rpcprog, (unsigned int)n, nconf, &nbuf))
   1184 			syslog(LOG_ERR, "rpcb_set: %u %d %s %s%s",
   1185 			    sep->se_rpcprog, n, nconf->nc_netid,
   1186 			    taddr2uaddr(nconf, &nbuf), clnt_spcreateerror(""));
   1187 	}
   1188 #endif /* RPC */
   1189 }
   1190 
   1191 static void
   1192 unregister_rpc(struct servtab *sep)
   1193 {
   1194 #ifdef RPC
   1195 	int n;
   1196 	struct netconfig *nconf;
   1197 
   1198 	if ((nconf = getnetconfigent(sep->se_proto+4)) == NULL) {
   1199 		syslog(LOG_ERR, "%s: getnetconfigent failed",
   1200 		    sep->se_proto);
   1201 		return;
   1202 	}
   1203 
   1204 	for (n = sep->se_rpcversl; n <= sep->se_rpcversh; n++) {
   1205 		if (debug)
   1206 			fprintf(stderr, "rpcb_unset(%u, %d, %s)\n",
   1207 			    sep->se_rpcprog, n, nconf->nc_netid);
   1208 		if (!rpcb_unset((unsigned int)sep->se_rpcprog, (unsigned int)n, nconf))
   1209 			syslog(LOG_ERR, "rpcb_unset(%u, %d, %s) failed\n",
   1210 			    sep->se_rpcprog, n, nconf->nc_netid);
   1211 	}
   1212 #endif /* RPC */
   1213 }
   1214 
   1215 
   1216 static struct servtab *
   1217 enter(struct servtab *cp)
   1218 {
   1219 	struct servtab *sep;
   1220 
   1221 	sep = malloc(sizeof (*sep));
   1222 	if (sep == NULL) {
   1223 		syslog(LOG_ERR, "Out of memory.");
   1224 		exit(1);
   1225 	}
   1226 	*sep = *cp;
   1227 	sep->se_fd = -1;
   1228 	sep->se_rpcprog = -1;
   1229 	sep->se_next = servtab;
   1230 	servtab = sep;
   1231 	return (sep);
   1232 }
   1233 
   1234 FILE	*fconfig = NULL;
   1235 struct	servtab serv;
   1236 char	line[LINE_MAX];
   1237 char    *defhost;
   1238 #ifdef IPSEC
   1239 static char *policy = NULL;
   1240 #endif
   1241 
   1242 static int
   1243 setconfig(void)
   1244 {
   1245 	if (defhost)
   1246 		free(defhost);
   1247 	defhost = newstr("*");
   1248 #ifdef IPSEC
   1249 	if (policy)
   1250 		free(policy);
   1251 	policy = NULL;
   1252 #endif
   1253 	if (fconfig != NULL) {
   1254 		fseek(fconfig, 0L, SEEK_SET);
   1255 		return (1);
   1256 	}
   1257 	fconfig = fopen(CONFIG, "r");
   1258 	return (fconfig != NULL);
   1259 }
   1260 
   1261 static void
   1262 endconfig(void)
   1263 {
   1264 	if (fconfig != NULL) {
   1265 		(void) fclose(fconfig);
   1266 		fconfig = NULL;
   1267 	}
   1268 	if (defhost != NULL) {
   1269 		free(defhost);
   1270 		defhost = NULL;
   1271 	}
   1272 }
   1273 
   1274 static struct servtab *
   1275 getconfigent(void)
   1276 {
   1277 	struct servtab *sep = &serv;
   1278 	int argc, val;
   1279 	char *cp, *cp0, *arg, *buf0, *buf1, *sz0, *sz1;
   1280 	static char TCPMUX_TOKEN[] = "tcpmux/";
   1281 #define MUX_LEN		(sizeof(TCPMUX_TOKEN)-1)
   1282 	char *hostdelim;
   1283 
   1284 more:
   1285 	while ((cp = nextline(fconfig)) != NULL) {
   1286 #ifdef IPSEC
   1287 		/* lines starting with #@ is not a comment, but the policy */
   1288 		if (cp[0] == '#' && cp[1] == '@') {
   1289 			char *p;
   1290 			for (p = cp + 2; p && *p && isspace((unsigned char)*p); p++)
   1291 				;
   1292 			if (*p == '\0') {
   1293 				if (policy)
   1294 					free(policy);
   1295 				policy = NULL;
   1296 			} else {
   1297 				if (ipsecsetup_test(p) < 0) {
   1298 					syslog(LOG_ERR,
   1299 						"%s: invalid ipsec policy \"%s\"",
   1300 						CONFIG, p);
   1301 					exit(1);
   1302 				} else {
   1303 					if (policy)
   1304 						free(policy);
   1305 					policy = newstr(p);
   1306 				}
   1307 			}
   1308 		}
   1309 #endif
   1310 		if (*cp == '#' || *cp == '\0')
   1311 			continue;
   1312 		break;
   1313 	}
   1314 	if (cp == NULL)
   1315 		return (NULL);
   1316 	/*
   1317 	 * clear the static buffer, since some fields (se_ctrladdr,
   1318 	 * for example) don't get initialized here.
   1319 	 */
   1320 	memset(sep, 0, sizeof *sep);
   1321 	arg = skip(&cp);
   1322 	if (cp == NULL) {
   1323 		/* got an empty line containing just blanks/tabs. */
   1324 		goto more;
   1325 	}
   1326 	/* Check for a host name. */
   1327 	hostdelim = strrchr(arg, ':');
   1328 	if (hostdelim) {
   1329 		*hostdelim = '\0';
   1330 		if (arg[0] == '[' && hostdelim > arg && hostdelim[-1] == ']') {
   1331 			hostdelim[-1] = '\0';
   1332 			sep->se_hostaddr = newstr(arg + 1);
   1333 		} else
   1334 			sep->se_hostaddr = newstr(arg);
   1335 		arg = hostdelim + 1;
   1336 		/*
   1337 		 * If the line is of the form `host:', then just change the
   1338 		 * default host for the following lines.
   1339 		 */
   1340 		if (*arg == '\0') {
   1341 			arg = skip(&cp);
   1342 			if (cp == NULL) {
   1343 				free(defhost);
   1344 				defhost = sep->se_hostaddr;
   1345 				goto more;
   1346 			}
   1347 		}
   1348 	} else
   1349 		sep->se_hostaddr = newstr(defhost);
   1350 	if (strncmp(arg, TCPMUX_TOKEN, MUX_LEN) == 0) {
   1351 		char *c = arg + MUX_LEN;
   1352 		if (*c == '+') {
   1353 			sep->se_type = MUXPLUS_TYPE;
   1354 			c++;
   1355 		} else
   1356 			sep->se_type = MUX_TYPE;
   1357 		sep->se_service = newstr(c);
   1358 	} else {
   1359 		sep->se_service = newstr(arg);
   1360 		sep->se_type = NORM_TYPE;
   1361 	}
   1362 
   1363 	arg = sskip(&cp);
   1364 	if (strncmp(arg, "stream", sizeof("stream") - 1) == 0) {
   1365 		char *accf, *accf_arg;
   1366 
   1367 		sep->se_socktype = SOCK_STREAM;
   1368 
   1369 		/* one and only one accept filter */
   1370 		accf = strchr(arg, ':');
   1371 		if (accf) {
   1372 	    		if (accf != strrchr(arg, ':') ||/* more than one */
   1373 	    		    *(accf + 1) == '\0') {	/* nothing beyond */
   1374 				sep->se_socktype = -1;
   1375 			} else {
   1376 				accf++;			/* skip delimiter */
   1377 				strlcpy(sep->se_accf.af_name, accf,
   1378 					sizeof(sep->se_accf.af_name));
   1379 				accf_arg = strchr(accf, ',');
   1380 				if (accf_arg) {	/* zero or one arg, no more */
   1381 					if (strrchr(accf, ',') != accf_arg) {
   1382 						sep->se_socktype = -1;
   1383 					} else {
   1384 						accf_arg++;
   1385 						strlcpy(sep->se_accf.af_arg,
   1386 							accf_arg,
   1387 							sizeof(sep->se_accf.af_arg));
   1388 					}
   1389 				}
   1390 			}
   1391 		}
   1392 	}
   1393 
   1394 	else if (strcmp(arg, "dgram") == 0)
   1395 		sep->se_socktype = SOCK_DGRAM;
   1396 	else if (strcmp(arg, "rdm") == 0)
   1397 		sep->se_socktype = SOCK_RDM;
   1398 	else if (strcmp(arg, "seqpacket") == 0)
   1399 		sep->se_socktype = SOCK_SEQPACKET;
   1400 	else if (strcmp(arg, "raw") == 0)
   1401 		sep->se_socktype = SOCK_RAW;
   1402 	else
   1403 		sep->se_socktype = -1;
   1404 
   1405 	arg = sskip(&cp);
   1406 	if (sep->se_type == NORM_TYPE &&
   1407 	    strncmp(arg, "faith/", strlen("faith/")) == 0) {
   1408 		arg += strlen("faith/");
   1409 		sep->se_type = FAITH_TYPE;
   1410 	}
   1411 	sep->se_proto = newstr(arg);
   1412 
   1413 #define	MALFORMED(arg) \
   1414 do { \
   1415 	syslog(LOG_ERR, "%s: malformed buffer size option `%s'", \
   1416 	    sep->se_service, (arg)); \
   1417 	goto more; \
   1418 	/*NOTREACHED*/ \
   1419 } while (/*CONSTCOND*/0)
   1420 
   1421 #define	GETVAL(arg) \
   1422 do { \
   1423 	if (!isdigit((unsigned char)*(arg))) \
   1424 		MALFORMED(arg); \
   1425 	val = (int)strtol((arg), &cp0, 10); \
   1426 	if (cp0 != NULL) { \
   1427 		if (cp0[1] != '\0') \
   1428 			MALFORMED((arg)); \
   1429 		if (cp0[0] == 'k') \
   1430 			val *= 1024; \
   1431 		if (cp0[0] == 'm') \
   1432 			val *= 1024 * 1024; \
   1433 	} \
   1434 	if (val < 1) { \
   1435 		syslog(LOG_ERR, "%s: invalid buffer size `%s'", \
   1436 		    sep->se_service, (arg)); \
   1437 		goto more; \
   1438 	} \
   1439 	/*NOTREACHED*/ \
   1440 } while (/*CONSTCOND*/0)
   1441 
   1442 #define	ASSIGN(arg) \
   1443 do { \
   1444 	if (strcmp((arg), "sndbuf") == 0) \
   1445 		sep->se_sndbuf = val; \
   1446 	else if (strcmp((arg), "rcvbuf") == 0) \
   1447 		sep->se_rcvbuf = val; \
   1448 	else \
   1449 		MALFORMED((arg)); \
   1450 } while (/*CONSTCOND*/0)
   1451 
   1452 	/*
   1453 	 * Extract the send and receive buffer sizes before parsing
   1454 	 * the protocol.
   1455 	 */
   1456 	sep->se_sndbuf = sep->se_rcvbuf = 0;
   1457 	buf0 = buf1 = sz0 = sz1 = NULL;
   1458 	if ((buf0 = strchr(sep->se_proto, ',')) != NULL) {
   1459 		/* Not meaningful for Tcpmux services. */
   1460 		if (ISMUX(sep)) {
   1461 			syslog(LOG_ERR, "%s: can't specify buffer sizes for "
   1462 			    "tcpmux services", sep->se_service);
   1463 			goto more;
   1464 		}
   1465 
   1466 		/* Skip the , */
   1467 		*buf0++ = '\0';
   1468 
   1469 		/* Check to see if another socket buffer size was specified. */
   1470 		if ((buf1 = strchr(buf0, ',')) != NULL) {
   1471 			/* Skip the , */
   1472 			*buf1++ = '\0';
   1473 
   1474 			/* Make sure a 3rd one wasn't specified. */
   1475 			if (strchr(buf1, ',') != NULL) {
   1476 				syslog(LOG_ERR, "%s: too many buffer sizes",
   1477 				    sep->se_service);
   1478 				goto more;
   1479 			}
   1480 
   1481 			/* Locate the size. */
   1482 			if ((sz1 = strchr(buf1, '=')) == NULL)
   1483 				MALFORMED(buf1);
   1484 
   1485 			/* Skip the = */
   1486 			*sz1++ = '\0';
   1487 		}
   1488 
   1489 		/* Locate the size. */
   1490 		if ((sz0 = strchr(buf0, '=')) == NULL)
   1491 			MALFORMED(buf0);
   1492 
   1493 		/* Skip the = */
   1494 		*sz0++ = '\0';
   1495 
   1496 		GETVAL(sz0);
   1497 		ASSIGN(buf0);
   1498 
   1499 		if (buf1 != NULL) {
   1500 			GETVAL(sz1);
   1501 			ASSIGN(buf1);
   1502 		}
   1503 	}
   1504 
   1505 #undef ASSIGN
   1506 #undef GETVAL
   1507 #undef MALFORMED
   1508 
   1509 	if (strcmp(sep->se_proto, "unix") == 0) {
   1510 		sep->se_family = AF_LOCAL;
   1511 	} else {
   1512 		val = (int)strlen(sep->se_proto);
   1513 		if (!val) {
   1514 			syslog(LOG_ERR, "%s: invalid protocol specified",
   1515 			    sep->se_service);
   1516 			goto more;
   1517 		}
   1518 		val = sep->se_proto[val - 1];
   1519 		switch (val) {
   1520 		case '4':	/*tcp4 or udp4*/
   1521 			sep->se_family = AF_INET;
   1522 			break;
   1523 #ifdef INET6
   1524 		case '6':	/*tcp6 or udp6*/
   1525 			sep->se_family = AF_INET6;
   1526 			break;
   1527 #endif
   1528 		default:
   1529 			sep->se_family = AF_INET;	/*will become AF_INET6*/
   1530 			break;
   1531 		}
   1532 		if (strncmp(sep->se_proto, "rpc/", 4) == 0) {
   1533 #ifdef RPC
   1534 			char *cp1, *ccp;
   1535 			cp1 = strchr(sep->se_service, '/');
   1536 			if (cp1 == 0) {
   1537 				syslog(LOG_ERR, "%s: no rpc version",
   1538 				    sep->se_service);
   1539 				goto more;
   1540 			}
   1541 			*cp1++ = '\0';
   1542 			sep->se_rpcversl = sep->se_rpcversh =
   1543 			    (int)strtol(cp1, &ccp, 0);
   1544 			if (ccp == cp1) {
   1545 		badafterall:
   1546 				syslog(LOG_ERR, "%s/%s: bad rpc version",
   1547 				    sep->se_service, cp1);
   1548 				goto more;
   1549 			}
   1550 			if (*ccp == '-') {
   1551 				cp1 = ccp + 1;
   1552 				sep->se_rpcversh = (int)strtol(cp1, &ccp, 0);
   1553 				if (ccp == cp1)
   1554 					goto badafterall;
   1555 			}
   1556 #else
   1557 			syslog(LOG_ERR, "%s: rpc services not suported",
   1558 			    sep->se_service);
   1559 			goto more;
   1560 #endif /* RPC */
   1561 		}
   1562 	}
   1563 	arg = sskip(&cp);
   1564 	{
   1565 		char *cp1;
   1566 		if ((cp1 = strchr(arg, ':')) == NULL)
   1567 			cp1 = strchr(arg, '.');
   1568 		if (cp1 != NULL) {
   1569 			*cp1++ = '\0';
   1570 			sep->se_max = atoi(cp1);
   1571 		} else
   1572 			sep->se_max = TOOMANY;
   1573 	}
   1574 	sep->se_wait = strcmp(arg, "wait") == 0;
   1575 	if (ISMUX(sep)) {
   1576 		/*
   1577 		 * Silently enforce "nowait" for TCPMUX services since
   1578 		 * they don't have an assigned port to listen on.
   1579 		 */
   1580 		sep->se_wait = 0;
   1581 
   1582 		if (strncmp(sep->se_proto, "tcp", 3)) {
   1583 			syslog(LOG_ERR,
   1584 			    "%s: bad protocol for tcpmux service %s",
   1585 			    CONFIG, sep->se_service);
   1586 			goto more;
   1587 		}
   1588 		if (sep->se_socktype != SOCK_STREAM) {
   1589 			syslog(LOG_ERR,
   1590 			    "%s: bad socket type for tcpmux service %s",
   1591 			    CONFIG, sep->se_service);
   1592 			goto more;
   1593 		}
   1594 	}
   1595 	sep->se_user = newstr(sskip(&cp));
   1596 	if ((sep->se_group = strchr(sep->se_user, ':')) != NULL)
   1597 		*sep->se_group++ = '\0';
   1598 	else if ((sep->se_group = strchr(sep->se_user, '.')) != NULL)
   1599 		*sep->se_group++ = '\0';
   1600 
   1601 	sep->se_server = newstr(sskip(&cp));
   1602 	if (strcmp(sep->se_server, "internal") == 0) {
   1603 		struct biltin *bi;
   1604 
   1605 		for (bi = biltins; bi->bi_service; bi++)
   1606 			if (bi->bi_socktype == sep->se_socktype &&
   1607 			    strcmp(bi->bi_service, sep->se_service) == 0)
   1608 				break;
   1609 		if (bi->bi_service == 0) {
   1610 			syslog(LOG_ERR, "internal service %s unknown",
   1611 			    sep->se_service);
   1612 			goto more;
   1613 		}
   1614 		sep->se_bi = bi;
   1615 		sep->se_wait = bi->bi_wait;
   1616 	} else
   1617 		sep->se_bi = NULL;
   1618 	argc = 0;
   1619 	for (arg = skip(&cp); cp; arg = skip(&cp)) {
   1620 		if (argc < MAXARGV)
   1621 			sep->se_argv[argc++] = newstr(arg);
   1622 	}
   1623 	while (argc <= MAXARGV)
   1624 		sep->se_argv[argc++] = NULL;
   1625 #ifdef IPSEC
   1626 	sep->se_policy = policy ? newstr(policy) : NULL;
   1627 #endif
   1628 	return (sep);
   1629 }
   1630 
   1631 static void
   1632 freeconfig(struct servtab *cp)
   1633 {
   1634 	int i;
   1635 
   1636 	if (cp->se_hostaddr)
   1637 		free(cp->se_hostaddr);
   1638 	if (cp->se_service)
   1639 		free(cp->se_service);
   1640 	if (cp->se_proto)
   1641 		free(cp->se_proto);
   1642 	if (cp->se_user)
   1643 		free(cp->se_user);
   1644 	/* Note: se_group is part of the newstr'ed se_user */
   1645 	if (cp->se_server)
   1646 		free(cp->se_server);
   1647 	for (i = 0; i < MAXARGV; i++)
   1648 		if (cp->se_argv[i])
   1649 			free(cp->se_argv[i]);
   1650 #ifdef IPSEC
   1651 	if (cp->se_policy)
   1652 		free(cp->se_policy);
   1653 #endif
   1654 }
   1655 
   1656 
   1657 /*
   1658  * Safe skip - if skip returns null, log a syntax error in the
   1659  * configuration file and exit.
   1660  */
   1661 static char *
   1662 sskip(char **cpp)
   1663 {
   1664 	char *cp;
   1665 
   1666 	cp = skip(cpp);
   1667 	if (cp == NULL) {
   1668 		syslog(LOG_ERR, "%s: syntax error", CONFIG);
   1669 		exit(1);
   1670 	}
   1671 	return (cp);
   1672 }
   1673 
   1674 static char *
   1675 skip(char **cpp)
   1676 {
   1677 	char *cp = *cpp;
   1678 	char *start;
   1679 	char quote;
   1680 
   1681 	if (*cpp == NULL)
   1682 		return (NULL);
   1683 
   1684 again:
   1685 	while (*cp == ' ' || *cp == '\t')
   1686 		cp++;
   1687 	if (*cp == '\0') {
   1688 		int c;
   1689 
   1690 		c = getc(fconfig);
   1691 		(void) ungetc(c, fconfig);
   1692 		if (c == ' ' || c == '\t')
   1693 			if ((cp = nextline(fconfig)) != NULL)
   1694 				goto again;
   1695 		*cpp = NULL;
   1696 		return (NULL);
   1697 	}
   1698 	start = cp;
   1699 	quote = '\0';
   1700 	while (*cp && (quote || (*cp != ' ' && *cp != '\t'))) {
   1701 		if (*cp == '\'' || *cp == '"') {
   1702 			if (quote && *cp != quote)
   1703 				cp++;
   1704 			else {
   1705 				if (quote)
   1706 					quote = '\0';
   1707 				else
   1708 					quote = *cp;
   1709 				memmove(cp, cp+1, strlen(cp));
   1710 			}
   1711 		} else
   1712 			cp++;
   1713 	}
   1714 	if (*cp != '\0')
   1715 		*cp++ = '\0';
   1716 	*cpp = cp;
   1717 	return (start);
   1718 }
   1719 
   1720 static char *
   1721 nextline(FILE *fd)
   1722 {
   1723 	char *cp;
   1724 
   1725 	if (fgets(line, (int)sizeof(line), fd) == NULL)
   1726 		return (NULL);
   1727 	cp = strchr(line, '\n');
   1728 	if (cp)
   1729 		*cp = '\0';
   1730 	return (line);
   1731 }
   1732 
   1733 static char *
   1734 newstr(const char *cp)
   1735 {
   1736 	char *dp;
   1737 	if ((dp = strdup((cp != NULL) ? cp : "")) != NULL)
   1738 		return (dp);
   1739 	syslog(LOG_ERR, "strdup: %m");
   1740 	exit(1);
   1741 	/*NOTREACHED*/
   1742 }
   1743 
   1744 static void
   1745 inetd_setproctitle(char *a, int s)
   1746 {
   1747 	socklen_t size;
   1748 	struct sockaddr_storage ss;
   1749 	char hbuf[NI_MAXHOST];
   1750 	const char *hp;
   1751 	struct sockaddr *sa;
   1752 
   1753 	size = sizeof(ss);
   1754 	sa = (struct sockaddr *)(void *)&ss;
   1755 	if (getpeername(s, sa, &size) == 0) {
   1756 		if (getnameinfo(sa, size, hbuf, (socklen_t)sizeof(hbuf), NULL,
   1757 		    0, niflags) != 0)
   1758 			hp = "?";
   1759 		else
   1760 			hp = hbuf;
   1761 		setproctitle("-%s [%s]", a, hp);
   1762 	} else
   1763 		setproctitle("-%s", a);
   1764 }
   1765 
   1766 static void
   1767 bump_nofile(void)
   1768 {
   1769 #define FD_CHUNK	32
   1770 	struct rlimit rl;
   1771 
   1772 	if (getrlimit(RLIMIT_NOFILE, &rl) < 0) {
   1773 		syslog(LOG_ERR, "getrlimit: %m");
   1774 		return;
   1775 	}
   1776 	rl.rlim_cur = MIN(rl.rlim_max, rl.rlim_cur + FD_CHUNK);
   1777 	if (rl.rlim_cur <= rlim_ofile_cur) {
   1778 		syslog(LOG_ERR,
   1779 		    "bump_nofile: cannot extend file limit, max = %d",
   1780 		    (int)rl.rlim_cur);
   1781 		return;
   1782 	}
   1783 
   1784 	if (setrlimit(RLIMIT_NOFILE, &rl) < 0) {
   1785 		syslog(LOG_ERR, "setrlimit: %m");
   1786 		return;
   1787 	}
   1788 
   1789 	rlim_ofile_cur = rl.rlim_cur;
   1790 	return;
   1791 }
   1792 
   1793 /*
   1794  * Internet services provided internally by inetd:
   1795  */
   1796 #define	BUFSIZE	4096
   1797 
   1798 /* ARGSUSED */
   1799 static void
   1800 echo_stream(int s, struct servtab *sep)	/* Echo service -- echo data back */
   1801 {
   1802 	char buffer[BUFSIZE];
   1803 	ssize_t i;
   1804 
   1805 	inetd_setproctitle(sep->se_service, s);
   1806 	while ((i = read(s, buffer, sizeof(buffer))) > 0 &&
   1807 	    write(s, buffer, (size_t)i) > 0)
   1808 		;
   1809 }
   1810 
   1811 /* ARGSUSED */
   1812 static void
   1813 echo_dg(int s, struct servtab *sep)	/* Echo service -- echo data back */
   1814 {
   1815 	char buffer[BUFSIZE];
   1816 	ssize_t i;
   1817 	socklen_t size;
   1818 	struct sockaddr_storage ss;
   1819 	struct sockaddr *sa;
   1820 
   1821 	sa = (struct sockaddr *)(void *)&ss;
   1822 	size = sizeof(ss);
   1823 	if ((i = recvfrom(s, buffer, sizeof(buffer), 0, sa, &size)) < 0)
   1824 		return;
   1825 	if (port_good_dg(sa))
   1826 		(void) sendto(s, buffer, (size_t)i, 0, sa, size);
   1827 }
   1828 
   1829 /* ARGSUSED */
   1830 static void
   1831 discard_stream(int s, struct servtab *sep) /* Discard service -- ignore data */
   1832 {
   1833 	char buffer[BUFSIZE];
   1834 
   1835 	inetd_setproctitle(sep->se_service, s);
   1836 	while ((errno = 0, read(s, buffer, sizeof(buffer)) > 0) ||
   1837 			errno == EINTR)
   1838 		;
   1839 }
   1840 
   1841 /* ARGSUSED */
   1842 static void
   1843 discard_dg(int s, struct servtab *sep)	/* Discard service -- ignore data */
   1844 
   1845 {
   1846 	char buffer[BUFSIZE];
   1847 
   1848 	(void) read(s, buffer, sizeof(buffer));
   1849 }
   1850 
   1851 #define LINESIZ 72
   1852 char ring[128];
   1853 char *endring;
   1854 
   1855 static void
   1856 initring(void)
   1857 {
   1858 	int i;
   1859 
   1860 	endring = ring;
   1861 
   1862 	for (i = 0; i <= 128; ++i)
   1863 		if (isprint(i))
   1864 			*endring++ = i;
   1865 }
   1866 
   1867 /* ARGSUSED */
   1868 static void
   1869 chargen_stream(int s,struct servtab *sep)	/* Character generator */
   1870 {
   1871 	size_t len;
   1872 	char *rs, text[LINESIZ+2];
   1873 
   1874 	inetd_setproctitle(sep->se_service, s);
   1875 
   1876 	if (!endring) {
   1877 		initring();
   1878 		rs = ring;
   1879 	}
   1880 
   1881 	text[LINESIZ] = '\r';
   1882 	text[LINESIZ + 1] = '\n';
   1883 	for (rs = ring;;) {
   1884 		if ((len = endring - rs) >= LINESIZ)
   1885 			memmove(text, rs, LINESIZ);
   1886 		else {
   1887 			memmove(text, rs, len);
   1888 			memmove(text + len, ring, LINESIZ - len);
   1889 		}
   1890 		if (++rs == endring)
   1891 			rs = ring;
   1892 		if (write(s, text, sizeof(text)) != sizeof(text))
   1893 			break;
   1894 	}
   1895 }
   1896 
   1897 /* ARGSUSED */
   1898 static void
   1899 chargen_dg(int s, struct servtab *sep)		/* Character generator */
   1900 {
   1901 	struct sockaddr_storage ss;
   1902 	struct sockaddr *sa;
   1903 	static char *rs;
   1904 	size_t len;
   1905 	socklen_t size;
   1906 	char text[LINESIZ+2];
   1907 
   1908 	if (endring == 0) {
   1909 		initring();
   1910 		rs = ring;
   1911 	}
   1912 
   1913 	sa = (struct sockaddr *)(void *)&ss;
   1914 	size = sizeof(ss);
   1915 	if (recvfrom(s, text, sizeof(text), 0, sa, &size) < 0)
   1916 		return;
   1917 
   1918 	if (!port_good_dg(sa))
   1919 		return;
   1920 
   1921 	if ((len = endring - rs) >= LINESIZ)
   1922 		memmove(text, rs, LINESIZ);
   1923 	else {
   1924 		memmove(text, rs, len);
   1925 		memmove(text + len, ring, LINESIZ - len);
   1926 	}
   1927 	if (++rs == endring)
   1928 		rs = ring;
   1929 	text[LINESIZ] = '\r';
   1930 	text[LINESIZ + 1] = '\n';
   1931 	(void) sendto(s, text, sizeof(text), 0, sa, size);
   1932 }
   1933 
   1934 /*
   1935  * Return a machine readable date and time, in the form of the
   1936  * number of seconds since midnight, Jan 1, 1900.  Since gettimeofday
   1937  * returns the number of seconds since midnight, Jan 1, 1970,
   1938  * we must add 2208988800 seconds to this figure to make up for
   1939  * some seventy years Bell Labs was asleep.
   1940  */
   1941 
   1942 static uint32_t
   1943 machtime(void)
   1944 {
   1945 	struct timeval tv;
   1946 
   1947 	if (gettimeofday(&tv, NULL) < 0) {
   1948 		if (debug)
   1949 			fprintf(stderr, "Unable to get time of day\n");
   1950 		return (0);
   1951 	}
   1952 #define	OFFSET ((uint32_t)25567 * 24*60*60)
   1953 	return (htonl((uint32_t)(tv.tv_sec + OFFSET)));
   1954 #undef OFFSET
   1955 }
   1956 
   1957 /* ARGSUSED */
   1958 static void
   1959 machtime_stream(int s, struct servtab *sep)
   1960 {
   1961 	uint32_t result;
   1962 
   1963 	result = machtime();
   1964 	(void) write(s, &result, sizeof(result));
   1965 }
   1966 
   1967 /* ARGSUSED */
   1968 void
   1969 machtime_dg(int s, struct servtab *sep)
   1970 {
   1971 	uint32_t result;
   1972 	struct sockaddr_storage ss;
   1973 	struct sockaddr *sa;
   1974 	socklen_t size;
   1975 
   1976 	sa = (struct sockaddr *)(void *)&ss;
   1977 	size = sizeof(ss);
   1978 	if (recvfrom(s, &result, sizeof(result), 0, sa, &size) < 0)
   1979 		return;
   1980 	if (!port_good_dg(sa))
   1981 		return;
   1982 	result = machtime();
   1983 	(void)sendto(s, &result, sizeof(result), 0, sa, size);
   1984 }
   1985 
   1986 /* ARGSUSED */
   1987 static void
   1988 daytime_stream(int s,struct servtab *sep)
   1989 /* Return human-readable time of day */
   1990 {
   1991 	char buffer[256];
   1992 	time_t clk;
   1993 	int len;
   1994 
   1995 	clk = time((time_t *) 0);
   1996 
   1997 	len = snprintf(buffer, sizeof buffer, "%.24s\r\n", ctime(&clk));
   1998 	(void) write(s, buffer, len);
   1999 }
   2000 
   2001 /* ARGSUSED */
   2002 void
   2003 daytime_dg(int s, struct servtab *sep)
   2004 /* Return human-readable time of day */
   2005 {
   2006 	char buffer[256];
   2007 	time_t clk;
   2008 	struct sockaddr_storage ss;
   2009 	struct sockaddr *sa;
   2010 	socklen_t size;
   2011 	int len;
   2012 
   2013 	clk = time((time_t *) 0);
   2014 
   2015 	sa = (struct sockaddr *)(void *)&ss;
   2016 	size = sizeof(ss);
   2017 	if (recvfrom(s, buffer, sizeof(buffer), 0, sa, &size) < 0)
   2018 		return;
   2019 	if (!port_good_dg(sa))
   2020 		return;
   2021 	len = snprintf(buffer, sizeof buffer, "%.24s\r\n", ctime(&clk));
   2022 	(void) sendto(s, buffer, len, 0, sa, size);
   2023 }
   2024 
   2025 /*
   2026  * print_service:
   2027  *	Dump relevant information to stderr
   2028  */
   2029 static void
   2030 print_service(const char *action, struct servtab *sep)
   2031 {
   2032 
   2033 	if (isrpcservice(sep))
   2034 		fprintf(stderr,
   2035 		    "%s: %s rpcprog=%d, rpcvers = %d/%d, proto=%s, wait.max=%d.%d, user:group=%s:%s builtin=%lx server=%s"
   2036 #ifdef IPSEC
   2037 		    " policy=\"%s\""
   2038 #endif
   2039 		    "\n",
   2040 		    action, sep->se_service,
   2041 		    sep->se_rpcprog, sep->se_rpcversh, sep->se_rpcversl, sep->se_proto,
   2042 		    sep->se_wait, sep->se_max, sep->se_user, sep->se_group,
   2043 		    (long)sep->se_bi, sep->se_server
   2044 #ifdef IPSEC
   2045 		    , (sep->se_policy ? sep->se_policy : "")
   2046 #endif
   2047 		    );
   2048 	else
   2049 		fprintf(stderr,
   2050 		    "%s: %s proto=%s%s, wait.max=%d.%d, user:group=%s:%s builtin=%lx server=%s"
   2051 #ifdef IPSEC
   2052 		    " policy=%s"
   2053 #endif
   2054 		    "\n",
   2055 		    action, sep->se_service,
   2056 		    sep->se_type == FAITH_TYPE ? "faith/" : "",
   2057 		    sep->se_proto,
   2058 		    sep->se_wait, sep->se_max, sep->se_user, sep->se_group,
   2059 		    (long)sep->se_bi, sep->se_server
   2060 #ifdef IPSEC
   2061 		    , (sep->se_policy ? sep->se_policy : "")
   2062 #endif
   2063 		    );
   2064 }
   2065 
   2066 static void
   2067 usage(void)
   2068 {
   2069 #ifdef LIBWRAP
   2070 	(void)fprintf(stderr, "usage: %s [-dl] [conf]\n", getprogname());
   2071 #else
   2072 	(void)fprintf(stderr, "usage: %s [-d] [conf]\n", getprogname());
   2073 #endif
   2074 	exit(1);
   2075 }
   2076 
   2077 
   2078 /*
   2079  *  Based on TCPMUX.C by Mark K. Lottor November 1988
   2080  *  sri-nic::ps:<mkl>tcpmux.c
   2081  */
   2082 
   2083 static int		/* # of characters upto \r,\n or \0 */
   2084 get_line(int fd,	char *buf, int len)
   2085 {
   2086 	int count = 0;
   2087 	ssize_t n;
   2088 
   2089 	do {
   2090 		n = read(fd, buf, len-count);
   2091 		if (n == 0)
   2092 			return (count);
   2093 		if (n < 0)
   2094 			return (-1);
   2095 		while (--n >= 0) {
   2096 			if (*buf == '\r' || *buf == '\n' || *buf == '\0')
   2097 				return (count);
   2098 			count++;
   2099 			buf++;
   2100 		}
   2101 	} while (count < len);
   2102 	return (count);
   2103 }
   2104 
   2105 #define MAX_SERV_LEN	(256+2)		/* 2 bytes for \r\n */
   2106 
   2107 #define strwrite(fd, buf)	(void) write(fd, buf, sizeof(buf)-1)
   2108 
   2109 static void
   2110 tcpmux(int ctrl, struct servtab *sep)
   2111 {
   2112 	char service[MAX_SERV_LEN+1];
   2113 	int len;
   2114 
   2115 	/* Get requested service name */
   2116 	if ((len = get_line(ctrl, service, MAX_SERV_LEN)) < 0) {
   2117 		strwrite(ctrl, "-Error reading service name\r\n");
   2118 		goto reject;
   2119 	}
   2120 	service[len] = '\0';
   2121 
   2122 	if (debug)
   2123 		fprintf(stderr, "tcpmux: someone wants %s\n", service);
   2124 
   2125 	/*
   2126 	 * Help is a required command, and lists available services,
   2127 	 * one per line.
   2128 	 */
   2129 	if (!strcasecmp(service, "help")) {
   2130 		strwrite(ctrl, "+Available services:\r\n");
   2131 		strwrite(ctrl, "help\r\n");
   2132 		for (sep = servtab; sep != NULL; sep = sep->se_next) {
   2133 			if (!ISMUX(sep))
   2134 				continue;
   2135 			(void)write(ctrl, sep->se_service,
   2136 			    strlen(sep->se_service));
   2137 			strwrite(ctrl, "\r\n");
   2138 		}
   2139 		goto reject;
   2140 	}
   2141 
   2142 	/* Try matching a service in inetd.conf with the request */
   2143 	for (sep = servtab; sep != NULL; sep = sep->se_next) {
   2144 		if (!ISMUX(sep))
   2145 			continue;
   2146 		if (!strcasecmp(service, sep->se_service)) {
   2147 			if (ISMUXPLUS(sep))
   2148 				strwrite(ctrl, "+Go\r\n");
   2149 			run_service(ctrl, sep, 1 /* forked */);
   2150 			return;
   2151 		}
   2152 	}
   2153 	strwrite(ctrl, "-Service not available\r\n");
   2154 reject:
   2155 	_exit(1);
   2156 }
   2157 
   2158 /*
   2159  * check if the address/port where send data to is one of the obvious ports
   2160  * that are used for denial of service attacks like two echo ports
   2161  * just echoing data between them
   2162  */
   2163 static int
   2164 port_good_dg(struct sockaddr *sa)
   2165 {
   2166 	struct in_addr in;
   2167 	struct sockaddr_in *sin;
   2168 #ifdef INET6
   2169 	struct in6_addr *in6;
   2170 	struct sockaddr_in6 *sin6;
   2171 #endif
   2172 	u_int16_t port;
   2173 	int i;
   2174 	char hbuf[NI_MAXHOST];
   2175 
   2176 	switch (sa->sa_family) {
   2177 	case AF_INET:
   2178 		sin = (struct sockaddr_in *)(void *)sa;
   2179 		in.s_addr = ntohl(sin->sin_addr.s_addr);
   2180 		port = ntohs(sin->sin_port);
   2181 #ifdef INET6
   2182 	v4chk:
   2183 #endif
   2184 		if (IN_MULTICAST(in.s_addr))
   2185 			goto bad;
   2186 		switch ((in.s_addr & 0xff000000) >> 24) {
   2187 		case 0: case 127: case 255:
   2188 			goto bad;
   2189 		}
   2190 		if (dg_broadcast(&in))
   2191 			goto bad;
   2192 		break;
   2193 #ifdef INET6
   2194 	case AF_INET6:
   2195 		sin6 = (struct sockaddr_in6 *)(void *)sa;
   2196 		in6 = &sin6->sin6_addr;
   2197 		port = ntohs(sin6->sin6_port);
   2198 		if (IN6_IS_ADDR_MULTICAST(in6) || IN6_IS_ADDR_UNSPECIFIED(in6))
   2199 			goto bad;
   2200 		if (IN6_IS_ADDR_V4MAPPED(in6) || IN6_IS_ADDR_V4COMPAT(in6)) {
   2201 			memcpy(&in, &in6->s6_addr[12], sizeof(in));
   2202 			in.s_addr = ntohl(in.s_addr);
   2203 			goto v4chk;
   2204 		}
   2205 		break;
   2206 #endif
   2207 	default:
   2208 		/* XXX unsupported af, is it safe to assume it to be safe? */
   2209 		return (1);
   2210 	}
   2211 
   2212 	for (i = 0; bad_ports[i] != 0; i++) {
   2213 		if (port == bad_ports[i])
   2214 			goto bad;
   2215 	}
   2216 
   2217 	return (1);
   2218 
   2219 bad:
   2220 	if (getnameinfo(sa, sa->sa_len, hbuf, (socklen_t)sizeof(hbuf), NULL, 0,
   2221 	    niflags) != 0)
   2222 		strlcpy(hbuf, "?", sizeof(hbuf));
   2223 	syslog(LOG_WARNING,"Possible DoS attack from %s, Port %d",
   2224 		hbuf, port);
   2225 	return (0);
   2226 }
   2227 
   2228 /* XXX need optimization */
   2229 static int
   2230 dg_broadcast(struct in_addr *in)
   2231 {
   2232 	struct ifaddrs *ifa, *ifap;
   2233 	struct sockaddr_in *sin;
   2234 
   2235 	if (getifaddrs(&ifap) < 0)
   2236 		return (0);
   2237 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
   2238 		if (ifa->ifa_addr->sa_family != AF_INET ||
   2239 		    (ifa->ifa_flags & IFF_BROADCAST) == 0)
   2240 			continue;
   2241 		sin = (struct sockaddr_in *)(void *)ifa->ifa_broadaddr;
   2242 		if (sin->sin_addr.s_addr == in->s_addr) {
   2243 			freeifaddrs(ifap);
   2244 			return (1);
   2245 		}
   2246 	}
   2247 	freeifaddrs(ifap);
   2248 	return (0);
   2249 }
   2250 
   2251 static int
   2252 my_kevent(const struct kevent *changelist, size_t nchanges,
   2253     struct kevent *eventlist, size_t nevents)
   2254 {
   2255 	int	result;
   2256 
   2257 	while ((result = kevent(kq, changelist, nchanges, eventlist, nevents,
   2258 	    NULL)) < 0)
   2259 		if (errno != EINTR) {
   2260 			syslog(LOG_ERR, "kevent: %m");
   2261 			exit(EXIT_FAILURE);
   2262 		}
   2263 
   2264 	return (result);
   2265 }
   2266 
   2267 static struct kevent *
   2268 allocchange(void)
   2269 {
   2270 	if (changes == A_CNT(changebuf)) {
   2271 		(void) my_kevent(changebuf, A_CNT(changebuf), NULL, 0);
   2272 		changes = 0;
   2273 	}
   2274 
   2275 	return (&changebuf[changes++]);
   2276 }
   2277