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ypbind.c revision 1.35
      1 /*	$NetBSD: ypbind.c,v 1.35 1998/02/12 03:32:51 lukem Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992, 1993 Theo de Raadt <deraadt (at) fsa.ca>
      5  * All rights reserved.
      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  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by Theo de Raadt.
     18  * 4. The name of the author may not be used to endorse or promote
     19  *    products derived from this software without specific prior written
     20  *    permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
     23  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     24  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
     26  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 #include <sys/cdefs.h>
     36 #ifndef LINT
     37 __RCSID("$NetBSD: ypbind.c,v 1.35 1998/02/12 03:32:51 lukem Exp $");
     38 #endif
     39 
     40 #include <sys/param.h>
     41 #include <sys/types.h>
     42 #include <sys/ioctl.h>
     43 #include <sys/signal.h>
     44 #include <sys/socket.h>
     45 #include <sys/file.h>
     46 #include <sys/fcntl.h>
     47 #include <sys/uio.h>
     48 #include <sys/syslog.h>
     49 #include <sys/stat.h>
     50 #include <limits.h>
     51 #include <stdio.h>
     52 #include <stdlib.h>
     53 #include <errno.h>
     54 #include <ctype.h>
     55 #include <dirent.h>
     56 #include <netdb.h>
     57 #include <string.h>
     58 #include <err.h>
     59 #include <rpc/rpc.h>
     60 #include <rpc/xdr.h>
     61 #include <net/if.h>
     62 #include <arpa/inet.h>
     63 #include <rpc/pmap_clnt.h>
     64 #include <rpc/pmap_prot.h>
     65 #include <rpc/pmap_rmt.h>
     66 #include <unistd.h>
     67 #include <rpcsvc/yp_prot.h>
     68 #include <rpcsvc/ypclnt.h>
     69 
     70 #include "pathnames.h"
     71 
     72 #ifndef O_SHLOCK
     73 #define O_SHLOCK 0
     74 #endif
     75 
     76 #define BUFSIZE		1400
     77 
     78 #define YPSERVERSSUFF	".ypservers"
     79 #define BINDINGDIR	__CONCAT(_PATH_VAR_YP, "binding")
     80 
     81 struct _dom_binding {
     82 	struct _dom_binding *dom_pnext;
     83 	char dom_domain[YPMAXDOMAIN + 1];
     84 	struct sockaddr_in dom_server_addr;
     85 	unsigned short int dom_server_port;
     86 	int dom_socket;
     87 	CLIENT *dom_client;
     88 	long dom_vers;
     89 	time_t dom_check_t;
     90 	time_t dom_ask_t;
     91 	int dom_lockfd;
     92 	int dom_alive;
     93 	u_int32_t dom_xid;
     94 };
     95 
     96 static char *domainname;
     97 
     98 static struct _dom_binding *ypbindlist;
     99 static int check;
    100 
    101 typedef enum {
    102 	YPBIND_DIRECT, YPBIND_BROADCAST, YPBIND_SETLOCAL, YPBIND_SETALL
    103 } ypbind_mode_t;
    104 
    105 ypbind_mode_t ypbindmode;
    106 
    107 /*
    108  * If ypbindmode is YPBIND_SETLOCAL or YPBIND_SETALL, this indicates
    109  * whether or not we've been "ypset".  If we haven't, we behave like
    110  * YPBIND_BROADCAST.  If we have, we behave like YPBIND_DIRECT.
    111  */
    112 int been_ypset;
    113 
    114 #ifdef DEBUG
    115 static int debug;
    116 #endif
    117 
    118 static int insecure;
    119 static int rpcsock, pingsock;
    120 static struct rmtcallargs rmtca;
    121 static struct rmtcallres rmtcr;
    122 static bool_t rmtcr_outval;
    123 static u_long rmtcr_port;
    124 static SVCXPRT *udptransp, *tcptransp;
    125 
    126 int	_yp_invalid_domain __P((const char *));		/* from libc */
    127 int	main __P((int, char *[]));
    128 
    129 static void usage __P((void));
    130 static struct _dom_binding *makebinding __P((const char *));
    131 static int makelock __P((struct _dom_binding *));
    132 static void removelock __P((struct _dom_binding *));
    133 static void *ypbindproc_null_2 __P((SVCXPRT *, void *));
    134 static void *ypbindproc_domain_2 __P((SVCXPRT *, void *));
    135 static void *ypbindproc_setdom_2 __P((SVCXPRT *, void *));
    136 static void ypbindprog_2 __P((struct svc_req *, SVCXPRT *));
    137 static void checkwork __P((void));
    138 static int ping __P((struct _dom_binding *));
    139 static int nag_servers __P((struct _dom_binding *));
    140 static enum clnt_stat handle_replies __P((void));
    141 static enum clnt_stat handle_ping __P((void));
    142 static void rpc_received __P((char *, struct sockaddr_in *, int));
    143 static struct _dom_binding *xid2ypdb __P((u_int32_t));
    144 static u_int32_t unique_xid __P((struct _dom_binding *));
    145 static int broadcast __P((char *, int));
    146 static int direct __P((char *, int));
    147 static int direct_set __P((char *, int, struct _dom_binding *));
    148 
    149 static void
    150 usage()
    151 {
    152 	extern char *__progname;
    153 	char *opt = "";
    154 #ifdef DEBUG
    155 	opt = " [-d]";
    156 #endif
    157 	(void) fprintf(stderr,
    158 	    "Usage: %s [-broadcast] [-insecure] [-ypset] [-ypsetme] %s\n",
    159 	    __progname, opt);
    160 	exit(1);
    161 }
    162 
    163 static struct _dom_binding *
    164 makebinding(dm)
    165 	const char *dm;
    166 {
    167 	struct _dom_binding *ypdb;
    168 
    169 	if ((ypdb = (struct _dom_binding *)malloc(sizeof *ypdb)) == NULL)
    170 		err(1, "makebinding");
    171 
    172 	(void) memset(ypdb, 0, sizeof *ypdb);
    173 	(void) strncpy(ypdb->dom_domain, dm, sizeof ypdb->dom_domain);
    174 	ypdb->dom_domain[sizeof(ypdb->dom_domain) - 1] = '\0';
    175 	return ypdb;
    176 }
    177 
    178 static int
    179 makelock(ypdb)
    180 	struct _dom_binding *ypdb;
    181 {
    182 	int fd;
    183 	char path[MAXPATHLEN];
    184 
    185 	(void) snprintf(path, sizeof(path), "%s/%s.%ld", BINDINGDIR,
    186 	    ypdb->dom_domain, ypdb->dom_vers);
    187 
    188 	if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) {
    189 		(void) mkdir(BINDINGDIR, 0755);
    190 		if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1)
    191 			return -1;
    192 	}
    193 
    194 #if O_SHLOCK == 0
    195 	(void) flock(fd, LOCK_SH);
    196 #endif
    197 	return fd;
    198 }
    199 
    200 static void
    201 removelock(ypdb)
    202 	struct _dom_binding *ypdb;
    203 {
    204 	char path[MAXPATHLEN];
    205 
    206 	(void) snprintf(path, sizeof(path), "%s/%s.%ld",
    207 	    BINDINGDIR, ypdb->dom_domain, ypdb->dom_vers);
    208 	(void) unlink(path);
    209 }
    210 
    211 static void *
    212 ypbindproc_null_2(transp, argp)
    213 	SVCXPRT *transp;
    214 	void *argp;
    215 {
    216 	static char res;
    217 
    218 #ifdef DEBUG
    219 	if (debug)
    220 		printf("ypbindproc_null_2\n");
    221 #endif
    222 	(void) memset(&res, 0, sizeof(res));
    223 	return (void *)&res;
    224 }
    225 
    226 static void *
    227 ypbindproc_domain_2(transp, argp)
    228 	SVCXPRT *transp;
    229 	void *argp;
    230 {
    231 	static struct ypbind_resp res;
    232 	struct _dom_binding *ypdb;
    233 	char *arg = *(char **) argp;
    234 	time_t now;
    235 	int count;
    236 
    237 #ifdef DEBUG
    238 	if (debug)
    239 		printf("ypbindproc_domain_2 %s\n", arg);
    240 #endif
    241 	if (_yp_invalid_domain(arg))
    242 		return NULL;
    243 
    244 	(void) memset(&res, 0, sizeof res);
    245 	res.ypbind_status = YPBIND_FAIL_VAL;
    246 
    247 	for (count = 0, ypdb = ypbindlist;
    248 	    ypdb != NULL;
    249 	    ypdb = ypdb->dom_pnext, count++) {
    250 		if (count > 100)
    251 			return NULL;		/* prevent denial of service */
    252 		if (!strcmp(ypdb->dom_domain, arg))
    253 			break;
    254 	}
    255 
    256 	if (ypdb == NULL) {
    257 		ypdb = makebinding(arg);
    258 		ypdb->dom_vers = YPVERS;
    259 		ypdb->dom_alive = 0;
    260 		ypdb->dom_lockfd = -1;
    261 		removelock(ypdb);
    262 		ypdb->dom_xid = unique_xid(ypdb);
    263 		ypdb->dom_pnext = ypbindlist;
    264 		ypbindlist = ypdb;
    265 		check++;
    266 #ifdef DEBUG
    267 		if (debug)
    268 			printf("unknown domain %s\n", arg);
    269 #endif
    270 		return NULL;
    271 	}
    272 
    273 	if (ypdb->dom_alive == 0) {
    274 #ifdef DEBUG
    275 		if (debug)
    276 			printf("dead domain %s\n", arg);
    277 #endif
    278 		return NULL;
    279 	}
    280 
    281 #ifdef HEURISTIC
    282 	time(&now);
    283 	if (now < ypdb->dom_ask_t + 5) {
    284 		/*
    285 		 * Hmm. More than 2 requests in 5 seconds have indicated
    286 		 * that my binding is possibly incorrect.
    287 		 * Ok, do an immediate poll of the server.
    288 		 */
    289 		if (ypdb->dom_check_t >= now) {
    290 			/* don't flood it */
    291 			ypdb->dom_check_t = 0;
    292 			check++;
    293 		}
    294 	}
    295 	ypdb->dom_ask_t = now;
    296 #endif
    297 
    298 	res.ypbind_status = YPBIND_SUCC_VAL;
    299 	res.ypbind_respbody.ypbind_bindinfo.ypbind_binding_addr.s_addr =
    300 		ypdb->dom_server_addr.sin_addr.s_addr;
    301 	res.ypbind_respbody.ypbind_bindinfo.ypbind_binding_port =
    302 		ypdb->dom_server_port;
    303 #ifdef DEBUG
    304 	if (debug)
    305 		printf("domain %s at %s/%d\n", ypdb->dom_domain,
    306 		    inet_ntoa(ypdb->dom_server_addr.sin_addr),
    307 		    ntohs(ypdb->dom_server_addr.sin_port));
    308 #endif
    309 	return &res;
    310 }
    311 
    312 static void *
    313 ypbindproc_setdom_2(transp, argp)
    314 	SVCXPRT *transp;
    315 	void *argp;
    316 {
    317 	struct ypbind_setdom *sd = argp;
    318 	struct sockaddr_in *fromsin, bindsin;
    319 	static bool_t res;
    320 
    321 #ifdef DEBUG
    322 	if (debug)
    323 		printf("ypbindproc_setdom_2 %s\n", inet_ntoa(bindsin.sin_addr));
    324 #endif
    325 	(void) memset(&res, 0, sizeof(res));
    326 	fromsin = svc_getcaller(transp);
    327 
    328 	switch (ypbindmode) {
    329 	case YPBIND_SETLOCAL:
    330 		if (fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) {
    331 #ifdef DEBUG
    332 			if (debug)
    333 				printf("ypset from %s denied\n",
    334 				    inet_ntoa(fromsin->sin_addr));
    335 #endif
    336 			return NULL;
    337 		}
    338 		/* FALLTHROUGH */
    339 
    340 	case YPBIND_SETALL:
    341 		been_ypset = 1;
    342 		break;
    343 
    344 	case YPBIND_DIRECT:
    345 	case YPBIND_BROADCAST:
    346 	default:
    347 #ifdef DEBUG
    348 		if (debug)
    349 			printf("ypset denied\n");
    350 #endif
    351 		return NULL;
    352 	}
    353 
    354 	if (ntohs(fromsin->sin_port) >= IPPORT_RESERVED) {
    355 #ifdef DEBUG
    356 		if (debug)
    357 			printf("ypset from unpriviledged port denied\n");
    358 #endif
    359 		return &res;
    360 	}
    361 
    362 	if (sd->ypsetdom_vers != YPVERS) {
    363 #ifdef DEBUG
    364 		if (debug)
    365 			printf("ypset with wrong version denied\n");
    366 #endif
    367 		return &res;
    368 	}
    369 
    370 	(void) memset(&bindsin, 0, sizeof bindsin);
    371 	bindsin.sin_family = AF_INET;
    372 	bindsin.sin_len = sizeof(bindsin);
    373 	bindsin.sin_addr = sd->ypsetdom_addr;
    374 	bindsin.sin_port = sd->ypsetdom_port;
    375 	rpc_received(sd->ypsetdom_domain, &bindsin, 1);
    376 
    377 #ifdef DEBUG
    378 	if (debug)
    379 		printf("ypset to %s succeeded\n", inet_ntoa(bindsin.sin_addr));
    380 #endif
    381 	res = 1;
    382 	return &res;
    383 }
    384 
    385 static void
    386 ypbindprog_2(rqstp, transp)
    387 	struct svc_req *rqstp;
    388 	register SVCXPRT *transp;
    389 {
    390 	union {
    391 		char ypbindproc_domain_2_arg[YPMAXDOMAIN + 1];
    392 		struct ypbind_setdom ypbindproc_setdom_2_arg;
    393 	} argument;
    394 	struct authunix_parms *creds;
    395 	char *result;
    396 	xdrproc_t xdr_argument, xdr_result;
    397 	void *(*local) __P((SVCXPRT *, void *));
    398 
    399 	switch (rqstp->rq_proc) {
    400 	case YPBINDPROC_NULL:
    401 		xdr_argument = xdr_void;
    402 		xdr_result = xdr_void;
    403 		local = ypbindproc_null_2;
    404 		break;
    405 
    406 	case YPBINDPROC_DOMAIN:
    407 		xdr_argument = xdr_ypdomain_wrap_string;
    408 		xdr_result = xdr_ypbind_resp;
    409 		local = ypbindproc_domain_2;
    410 		break;
    411 
    412 	case YPBINDPROC_SETDOM:
    413 		switch (rqstp->rq_cred.oa_flavor) {
    414 		case AUTH_UNIX:
    415 			creds = (struct authunix_parms *)rqstp->rq_clntcred;
    416 			if (creds->aup_uid != 0) {
    417 				svcerr_auth(transp, AUTH_BADCRED);
    418 				return;
    419 			}
    420 			break;
    421 		default:
    422 			svcerr_auth(transp, AUTH_TOOWEAK);
    423 			return;
    424 		}
    425 
    426 		xdr_argument = xdr_ypbind_setdom;
    427 		xdr_result = xdr_void;
    428 		local = ypbindproc_setdom_2;
    429 		break;
    430 
    431 	default:
    432 		svcerr_noproc(transp);
    433 		return;
    434 	}
    435 	(void) memset(&argument, 0, sizeof(argument));
    436 	if (!svc_getargs(transp, xdr_argument, (caddr_t)&argument)) {
    437 		svcerr_decode(transp);
    438 		return;
    439 	}
    440 	result = (*local)(transp, &argument);
    441 	if (result != NULL && !svc_sendreply(transp, xdr_result, result)) {
    442 		svcerr_systemerr(transp);
    443 	}
    444 	return;
    445 }
    446 
    447 int
    448 main(argc, argv)
    449 	int argc;
    450 	char *argv[];
    451 {
    452 	struct timeval tv;
    453 	fd_set fdsr;
    454 	int width, lockfd;
    455 	int evil = 0, one;
    456 	char pathname[MAXPATHLEN];
    457 	struct stat st;
    458 
    459 	yp_get_default_domain(&domainname);
    460 	if (domainname[0] == '\0')
    461 		errx(1, "Domainname not set. Aborting.");
    462 
    463 	/*
    464 	 * Per traditional ypbind(8) semantics, if a ypservers
    465 	 * file does not exist, we default to broadcast mode.
    466 	 * If the file does exist, we default to direct mode.
    467 	 * Note that we can still override direct mode by passing
    468 	 * the -broadcast flag.
    469 	 */
    470 	snprintf(pathname, sizeof(pathname), "%s/%s%s", BINDINGDIR,
    471 	    domainname, YPSERVERSSUFF);
    472 	if (stat(pathname, &st) < 0) {
    473 #ifdef DEBUG
    474 		if (debug)
    475 			fprintf(stderr,
    476 			    "%s does not exist, defaulting to broadcast\n",
    477 			    pathname);
    478 #endif
    479 		ypbindmode = YPBIND_BROADCAST;
    480 	} else
    481 		ypbindmode = YPBIND_DIRECT;
    482 
    483 	while (--argc) {
    484 		++argv;
    485 		if (!strcmp("-insecure", *argv))
    486 			insecure = 1;
    487 		else if (!strcmp("-ypset", *argv))
    488 			ypbindmode = YPBIND_SETALL;
    489 		else if (!strcmp("-ypsetme", *argv))
    490 			ypbindmode = YPBIND_SETLOCAL;
    491 		else if (!strcmp("-broadcast", *argv))
    492 			ypbindmode = YPBIND_BROADCAST;
    493 #ifdef DEBUG
    494 		else if (!strcmp("-d", *argv))
    495 			debug++;
    496 #endif
    497 		else
    498 			usage();
    499 	}
    500 
    501 	/* blow away everything in BINDINGDIR */
    502 
    503 	lockfd = open(_PATH_YPBIND_LOCK, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644);
    504 	if (lockfd == -1)
    505 		err(1, "Cannot create %s", _PATH_YPBIND_LOCK);
    506 
    507 #if O_SHLOCK == 0
    508 	(void) flock(lockfd, LOCK_SH);
    509 #endif
    510 
    511 	(void) pmap_unset(YPBINDPROG, YPBINDVERS);
    512 
    513 	udptransp = svcudp_create(RPC_ANYSOCK);
    514 	if (udptransp == NULL)
    515 		errx(1, "Cannot create udp service.");
    516 
    517 	if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
    518 	    IPPROTO_UDP))
    519 		errx(1, "Unable to register (YPBINDPROG, YPBINDVERS, udp).");
    520 
    521 	tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0);
    522 	if (tcptransp == NULL)
    523 		errx(1, "Cannot create tcp service.");
    524 
    525 	if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
    526 	    IPPROTO_TCP))
    527 		errx(1, "Unable to register (YPBINDPROG, YPBINDVERS, tcp).");
    528 
    529 	/* XXX use SOCK_STREAM for direct queries? */
    530 	if ((rpcsock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
    531 		err(1, "rpc socket");
    532 	if ((pingsock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
    533 		err(1, "ping socket");
    534 
    535 	(void) fcntl(rpcsock, F_SETFL, fcntl(rpcsock, F_GETFL, 0) | FNDELAY);
    536 	(void) fcntl(pingsock, F_SETFL, fcntl(pingsock, F_GETFL, 0) | FNDELAY);
    537 
    538 	one = 1;
    539 	(void) setsockopt(rpcsock, SOL_SOCKET, SO_BROADCAST, &one, sizeof(one));
    540 	rmtca.prog = YPPROG;
    541 	rmtca.vers = YPVERS;
    542 	rmtca.proc = YPPROC_DOMAIN_NONACK;
    543 	rmtca.xdr_args = NULL;		/* set at call time */
    544 	rmtca.args_ptr = NULL;		/* set at call time */
    545 	rmtcr.port_ptr = &rmtcr_port;
    546 	rmtcr.xdr_results = xdr_bool;
    547 	rmtcr.results_ptr = (caddr_t)&rmtcr_outval;
    548 
    549 	if (_yp_invalid_domain(domainname))
    550 		errx(1, "bad domainname: %s", domainname);
    551 
    552 	/* build initial domain binding, make it "unsuccessful" */
    553 	ypbindlist = makebinding(domainname);
    554 	ypbindlist->dom_vers = YPVERS;
    555 	ypbindlist->dom_alive = 0;
    556 	ypbindlist->dom_lockfd = -1;
    557 	removelock(ypbindlist);
    558 
    559 	checkwork();
    560 
    561 	width = svc_maxfd;
    562 	if (rpcsock > width)
    563 		width = rpcsock;
    564 	if (pingsock > width)
    565 		width = pingsock;
    566 	width++;
    567 
    568 	for (;;) {
    569 		fdsr = svc_fdset;
    570 		FD_SET(rpcsock, &fdsr);
    571 		FD_SET(pingsock, &fdsr);
    572 		tv.tv_sec = 1;
    573 		tv.tv_usec = 0;
    574 
    575 		switch (select(width, &fdsr, NULL, NULL, &tv)) {
    576 		case 0:
    577 			checkwork();
    578 			break;
    579 		case -1:
    580 			warn("select");
    581 			break;
    582 		default:
    583 			if (FD_ISSET(rpcsock, &fdsr))
    584 				handle_replies();
    585 			if (FD_ISSET(pingsock, &fdsr))
    586 				handle_ping();
    587 			svc_getreqset(&fdsr);
    588 			if (check)
    589 				checkwork();
    590 			break;
    591 		}
    592 
    593 		if (!evil && ypbindlist->dom_alive) {
    594 			evil = 1;
    595 #ifdef DEBUG
    596 			if (!debug)
    597 #endif
    598 				daemon(0, 0);
    599 		}
    600 	}
    601 }
    602 
    603 /*
    604  * State transition is done like this:
    605  *
    606  * STATE	EVENT		ACTION			NEWSTATE	TIMEOUT
    607  * no binding	timeout		broadcast 		no binding	5 sec
    608  * no binding	answer		--			binding		60 sec
    609  * binding	timeout		ping server		checking	5 sec
    610  * checking	timeout		ping server + broadcast	checking	5 sec
    611  * checking	answer		--			binding		60 sec
    612  */
    613 void
    614 checkwork()
    615 {
    616 	struct _dom_binding *ypdb;
    617 	time_t t;
    618 
    619 	check = 0;
    620 
    621 	time(&t);
    622 	for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
    623 		if (ypdb->dom_check_t < t) {
    624 			if (ypdb->dom_alive == 1)
    625 				ping(ypdb);
    626 			else
    627 				nag_servers(ypdb);
    628 			time(&t);
    629 			ypdb->dom_check_t = t + 5;
    630 		}
    631 	}
    632 }
    633 
    634 int
    635 ping(ypdb)
    636 	struct _dom_binding *ypdb;
    637 {
    638 	char *dom = ypdb->dom_domain;
    639 	struct rpc_msg msg;
    640 	char buf[BUFSIZE];
    641 	enum clnt_stat st;
    642 	int outlen;
    643 	AUTH *rpcua;
    644 	XDR xdr;
    645 
    646 	(void) memset(&xdr, 0, sizeof xdr);
    647 	(void) memset(&msg, 0, sizeof msg);
    648 
    649 	rpcua = authunix_create_default();
    650 	if (rpcua == NULL) {
    651 #ifdef DEBUG
    652 		if (debug)
    653 			printf("cannot get unix auth\n");
    654 #endif
    655 		return RPC_SYSTEMERROR;
    656 	}
    657 
    658 	msg.rm_direction = CALL;
    659 	msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
    660 	msg.rm_call.cb_prog = YPPROG;
    661 	msg.rm_call.cb_vers = YPVERS;
    662 	msg.rm_call.cb_proc = YPPROC_DOMAIN_NONACK;
    663 	msg.rm_call.cb_cred = rpcua->ah_cred;
    664 	msg.rm_call.cb_verf = rpcua->ah_verf;
    665 
    666 	msg.rm_xid = ypdb->dom_xid;
    667 	xdrmem_create(&xdr, buf, sizeof buf, XDR_ENCODE);
    668 	if (!xdr_callmsg(&xdr, &msg)) {
    669 		st = RPC_CANTENCODEARGS;
    670 		AUTH_DESTROY(rpcua);
    671 		return st;
    672 	}
    673 	if (!xdr_ypdomain_wrap_string(&xdr, &dom)) {
    674 		st = RPC_CANTENCODEARGS;
    675 		AUTH_DESTROY(rpcua);
    676 		return st;
    677 	}
    678 	outlen = (int)xdr_getpos(&xdr);
    679 	xdr_destroy(&xdr);
    680 	if (outlen < 1) {
    681 		st = RPC_CANTENCODEARGS;
    682 		AUTH_DESTROY(rpcua);
    683 		return st;
    684 	}
    685 	AUTH_DESTROY(rpcua);
    686 
    687 	ypdb->dom_alive = 2;
    688 	if (sendto(pingsock, buf, outlen, 0,
    689 		   (struct sockaddr *)&ypdb->dom_server_addr,
    690 		   sizeof ypdb->dom_server_addr) == -1)
    691 		warn("ping: sendto");
    692 	return 0;
    693 
    694 }
    695 
    696 static int
    697 nag_servers(ypdb)
    698 	struct _dom_binding *ypdb;
    699 {
    700 	char *dom = ypdb->dom_domain;
    701 	struct rpc_msg msg;
    702 	char buf[BUFSIZE];
    703 	enum clnt_stat st;
    704 	int outlen;
    705 	AUTH *rpcua;
    706 	XDR xdr;
    707 
    708 	rmtca.xdr_args = xdr_ypdomain_wrap_string;
    709 	rmtca.args_ptr = (char *)&dom;
    710 
    711 	(void) memset(&xdr, 0, sizeof xdr);
    712 	(void) memset(&msg, 0, sizeof msg);
    713 
    714 	rpcua = authunix_create_default();
    715 	if (rpcua == NULL) {
    716 #ifdef DEBUG
    717 		if (debug)
    718 			printf("cannot get unix auth\n");
    719 #endif
    720 		return RPC_SYSTEMERROR;
    721 	}
    722 	msg.rm_direction = CALL;
    723 	msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
    724 	msg.rm_call.cb_prog = PMAPPROG;
    725 	msg.rm_call.cb_vers = PMAPVERS;
    726 	msg.rm_call.cb_proc = PMAPPROC_CALLIT;
    727 	msg.rm_call.cb_cred = rpcua->ah_cred;
    728 	msg.rm_call.cb_verf = rpcua->ah_verf;
    729 
    730 	msg.rm_xid = ypdb->dom_xid;
    731 	xdrmem_create(&xdr, buf, sizeof buf, XDR_ENCODE);
    732 	if (!xdr_callmsg(&xdr, &msg)) {
    733 		st = RPC_CANTENCODEARGS;
    734 		AUTH_DESTROY(rpcua);
    735 		return st;
    736 	}
    737 	if (!xdr_rmtcall_args(&xdr, &rmtca)) {
    738 		st = RPC_CANTENCODEARGS;
    739 		AUTH_DESTROY(rpcua);
    740 		return st;
    741 	}
    742 	outlen = (int)xdr_getpos(&xdr);
    743 	xdr_destroy(&xdr);
    744 	if (outlen < 1) {
    745 		st = RPC_CANTENCODEARGS;
    746 		AUTH_DESTROY(rpcua);
    747 		return st;
    748 	}
    749 	AUTH_DESTROY(rpcua);
    750 
    751 	if (ypdb->dom_lockfd != -1) {
    752 		(void) close(ypdb->dom_lockfd);
    753 		ypdb->dom_lockfd = -1;
    754 		removelock(ypdb);
    755 	}
    756 
    757 	if (ypdb->dom_alive == 2) {
    758 		/*
    759 		 * This resolves the following situation:
    760 		 * ypserver on other subnet was once bound,
    761 		 * but rebooted and is now using a different port
    762 		 */
    763 		struct sockaddr_in bindsin;
    764 
    765 		memset(&bindsin, 0, sizeof bindsin);
    766 		bindsin.sin_family = AF_INET;
    767 		bindsin.sin_len = sizeof(bindsin);
    768 		bindsin.sin_port = htons(PMAPPORT);
    769 		bindsin.sin_addr = ypdb->dom_server_addr.sin_addr;
    770 
    771 		if (sendto(rpcsock, buf, outlen, 0, (struct sockaddr *)&bindsin,
    772 			   sizeof bindsin) == -1)
    773 			warn("broadcast: sendto");
    774 	}
    775 
    776 	switch (ypbindmode) {
    777 	case YPBIND_SETALL:
    778 	case YPBIND_SETLOCAL:
    779 		if (been_ypset)
    780 			return direct_set(buf, outlen, ypdb);
    781 		/* FALLTHROUGH */
    782 
    783 	case YPBIND_BROADCAST:
    784 		return broadcast(buf, outlen);
    785 
    786 	case YPBIND_DIRECT:
    787 		return direct(buf, outlen);
    788 	}
    789 
    790 	return -1;
    791 }
    792 
    793 static int
    794 broadcast(buf, outlen)
    795 	char *buf;
    796 	int outlen;
    797 {
    798 	struct ifconf ifc;
    799 	struct ifreq ifreq, *ifr;
    800 	struct in_addr in;
    801 	int i, sock, len;
    802 	char inbuf[8192];
    803 	struct sockaddr_in bindsin;
    804 
    805 	/* find all networks and send the RPC packet out them all */
    806 	if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
    807 		warn("broadcast: socket");
    808 		return -1;
    809 	}
    810 
    811 	memset(&bindsin, 0, sizeof bindsin);
    812 	bindsin.sin_family = AF_INET;
    813 	bindsin.sin_len = sizeof(bindsin);
    814 	bindsin.sin_port = htons(PMAPPORT);
    815 
    816 	ifc.ifc_len = sizeof inbuf;
    817 	ifc.ifc_buf = inbuf;
    818 	if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) {
    819 		(void) close(sock);
    820 		warn("broadcast: ioctl(SIOCGIFCONF)");
    821 		return -1;
    822 	}
    823 	ifr = ifc.ifc_req;
    824 	ifreq.ifr_name[0] = '\0';
    825 	for (i = 0; i < ifc.ifc_len; i += len, ifr = (struct ifreq *)((caddr_t)ifr + len)) {
    826 #if defined(BSD) && BSD >= 199103
    827 		len = sizeof ifr->ifr_name + ifr->ifr_addr.sa_len;
    828 #else
    829 		len = sizeof ifc.ifc_len / sizeof(struct ifreq);
    830 #endif
    831 		ifreq = *ifr;
    832 		if (ifreq.ifr_addr.sa_family != AF_INET)
    833 			continue;
    834 		if (ioctl(sock, SIOCGIFFLAGS, &ifreq) < 0) {
    835 			warn("broadcast: ioctl(SIOCGIFFLAGS)");
    836 			continue;
    837 		}
    838 		if ((ifreq.ifr_flags & IFF_UP) == 0)
    839 			continue;
    840 
    841 		ifreq.ifr_flags &= (IFF_LOOPBACK | IFF_BROADCAST);
    842 		if (ifreq.ifr_flags == IFF_BROADCAST) {
    843 			if (ioctl(sock, SIOCGIFBRDADDR, &ifreq) < 0) {
    844 				warn("broadcast: ioctl(SIOCGIFBRDADDR)");
    845 				continue;
    846 			}
    847 		} else if (ifreq.ifr_flags == IFF_LOOPBACK) {
    848 			if (ioctl(sock, SIOCGIFADDR, &ifreq) < 0) {
    849 				warn("broadcast: ioctl(SIOCGIFADDR)");
    850 				continue;
    851 			}
    852 		} else
    853 			continue;
    854 
    855 		in = ((struct sockaddr_in *)&ifreq.ifr_addr)->sin_addr;
    856 		bindsin.sin_addr = in;
    857 		if (sendto(rpcsock, buf, outlen, 0, (struct sockaddr *)&bindsin,
    858 			   sizeof bindsin) == -1)
    859 			warn("broadcast: sendto");
    860 	}
    861 	(void) close(sock);
    862 	return 0;
    863 }
    864 
    865 static int
    866 direct(buf, outlen)
    867 	char *buf;
    868 	int outlen;
    869 {
    870 	static FILE *df;
    871 	static char ypservers_path[MAXPATHLEN];
    872 	char line[_POSIX2_LINE_MAX];
    873 	char *p;
    874 	struct hostent *hp;
    875 	struct sockaddr_in bindsin;
    876 	int i, count = 0;
    877 
    878 	if (df)
    879 		rewind(df);
    880 	else {
    881 		snprintf(ypservers_path, sizeof(ypservers_path),
    882 		    "%s/%s%s", BINDINGDIR, domainname, YPSERVERSSUFF);
    883 		df = fopen(ypservers_path, "r");
    884 		if (df == NULL)
    885 			err(1, ypservers_path);
    886 	}
    887 
    888 	memset(&bindsin, 0, sizeof bindsin);
    889 	bindsin.sin_family = AF_INET;
    890 	bindsin.sin_len = sizeof(bindsin);
    891 	bindsin.sin_port = htons(PMAPPORT);
    892 
    893 	while(fgets(line, sizeof(line), df) != NULL) {
    894 		/* skip lines that are too big */
    895 		p = strchr(line, '\n');
    896 		if (p == NULL) {
    897 			int c;
    898 
    899 			while ((c = getc(df)) != '\n' && c != EOF)
    900 				;
    901 			continue;
    902 		}
    903 		*p = '\0';
    904 		p = line;
    905 		while (isspace(*p))
    906 			p++;
    907 		if (*p == '#')
    908 			continue;
    909 		hp = gethostbyname(p);
    910 		if (!hp) {
    911 			herror(p);
    912 			continue;
    913 		}
    914 		/* step through all addresses in case first is unavailable */
    915 		for (i = 0; hp->h_addr_list[i]; i++) {
    916 			memmove(&bindsin.sin_addr, hp->h_addr_list[0],
    917 			    hp->h_length);
    918 			if (sendto(rpcsock, buf, outlen, 0,
    919 			    (struct sockaddr *)&bindsin, sizeof bindsin) < 0) {
    920 				warn("direct: sendto");
    921 				continue;
    922 			} else
    923 				count++;
    924 		}
    925 	}
    926 	if (!count)
    927 		errx(1, "no contactable servers found in %s",
    928 		    ypservers_path);
    929 
    930 	return 0;
    931 }
    932 
    933 static int
    934 direct_set(buf, outlen, ypdb)
    935 	char *buf;
    936 	int outlen;
    937 	struct _dom_binding *ypdb;
    938 {
    939 	struct sockaddr_in bindsin;
    940 	char path[MAXPATHLEN];
    941 	struct iovec iov[2];
    942 	struct ypbind_resp ybr;
    943 	SVCXPRT dummy_svc;
    944 	int fd, bytes;
    945 
    946 	/*
    947 	 * Gack, we lose if binding file went away.  We reset
    948 	 * "been_set" if this happens, otherwise we'll never
    949 	 * bind again.
    950 	 */
    951 	snprintf(path, sizeof(path), "%s/%s.%ld", BINDINGDIR,
    952 	    ypdb->dom_domain, ypdb->dom_vers);
    953 
    954 	if ((fd = open(path, O_SHLOCK|O_RDONLY, 0644)) == -1) {
    955 		warn(path);
    956 		been_ypset = 0;
    957 		return -1;
    958 	}
    959 
    960 #if O_SHLOCK == 0
    961 	(void) flock(fd, LOCK_SH);
    962 #endif
    963 
    964 	/* Read the binding file... */
    965 	iov[0].iov_base = (caddr_t)&(dummy_svc.xp_port);
    966 	iov[0].iov_len = sizeof(dummy_svc.xp_port);
    967 	iov[1].iov_base = (caddr_t)&ybr;
    968 	iov[1].iov_len = sizeof(ybr);
    969 	bytes = readv(fd, iov, 2);
    970 	(void)close(fd);
    971 	if (bytes != (iov[0].iov_len + iov[1].iov_len)) {
    972 		/* Binding file corrupt? */
    973 		warn(path);
    974 		been_ypset = 0;
    975 		return -1;
    976 	}
    977 
    978 	bindsin.sin_addr =
    979 	    ybr.ypbind_respbody.ypbind_bindinfo.ypbind_binding_addr;
    980 
    981 	if (sendto(rpcsock, buf, outlen, 0, (struct sockaddr *)&bindsin,
    982 	    sizeof(bindsin)) < 0) {
    983 		warn("direct_set: sendto");
    984 		return -1;
    985 	}
    986 
    987 	return 0;
    988 }
    989 
    990 static enum clnt_stat
    991 handle_replies()
    992 {
    993 	char buf[BUFSIZE];
    994 	int fromlen, inlen;
    995 	struct _dom_binding *ypdb;
    996 	struct sockaddr_in raddr;
    997 	struct rpc_msg msg;
    998 	XDR xdr;
    999 
   1000 recv_again:
   1001 	(void) memset(&xdr, 0, sizeof(xdr));
   1002 	(void) memset(&msg, 0, sizeof(msg));
   1003 	msg.acpted_rply.ar_verf = _null_auth;
   1004 	msg.acpted_rply.ar_results.where = (caddr_t)&rmtcr;
   1005 	msg.acpted_rply.ar_results.proc = xdr_rmtcallres;
   1006 
   1007 try_again:
   1008 	fromlen = sizeof (struct sockaddr);
   1009 	inlen = recvfrom(rpcsock, buf, sizeof buf, 0,
   1010 		(struct sockaddr *)&raddr, &fromlen);
   1011 	if (inlen < 0) {
   1012 		if (errno == EINTR)
   1013 			goto try_again;
   1014 		return RPC_CANTRECV;
   1015 	}
   1016 	if (inlen < sizeof(u_int32_t))
   1017 		goto recv_again;
   1018 
   1019 	/*
   1020 	 * see if reply transaction id matches sent id.
   1021 	 * If so, decode the results.
   1022 	 */
   1023 	xdrmem_create(&xdr, buf, (u_int)inlen, XDR_DECODE);
   1024 	if (xdr_replymsg(&xdr, &msg)) {
   1025 		if ((msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
   1026 		    (msg.acpted_rply.ar_stat == SUCCESS)) {
   1027 			raddr.sin_port = htons((u_short)rmtcr_port);
   1028 			ypdb = xid2ypdb(msg.rm_xid);
   1029 			if (ypdb != NULL)
   1030 				rpc_received(ypdb->dom_domain, &raddr, 0);
   1031 		}
   1032 	}
   1033 	xdr.x_op = XDR_FREE;
   1034 	msg.acpted_rply.ar_results.proc = xdr_void;
   1035 	xdr_destroy(&xdr);
   1036 
   1037 	return RPC_SUCCESS;
   1038 }
   1039 
   1040 static enum clnt_stat
   1041 handle_ping()
   1042 {
   1043 	char buf[BUFSIZE];
   1044 	int fromlen, inlen;
   1045 	struct _dom_binding *ypdb;
   1046 	struct sockaddr_in raddr;
   1047 	struct rpc_msg msg;
   1048 	XDR xdr;
   1049 	bool_t res;
   1050 
   1051 recv_again:
   1052 	(void) memset(&xdr, 0, sizeof(xdr));
   1053 	(void) memset(&msg, 0, sizeof(msg));
   1054 	msg.acpted_rply.ar_verf = _null_auth;
   1055 	msg.acpted_rply.ar_results.where = (caddr_t)&res;
   1056 	msg.acpted_rply.ar_results.proc = xdr_bool;
   1057 
   1058 try_again:
   1059 	fromlen = sizeof (struct sockaddr);
   1060 	inlen = recvfrom(pingsock, buf, sizeof buf, 0,
   1061 		(struct sockaddr *)&raddr, &fromlen);
   1062 	if (inlen < 0) {
   1063 		if (errno == EINTR)
   1064 			goto try_again;
   1065 		return RPC_CANTRECV;
   1066 	}
   1067 	if (inlen < sizeof(u_int32_t))
   1068 		goto recv_again;
   1069 
   1070 	/*
   1071 	 * see if reply transaction id matches sent id.
   1072 	 * If so, decode the results.
   1073 	 */
   1074 	xdrmem_create(&xdr, buf, (u_int)inlen, XDR_DECODE);
   1075 	if (xdr_replymsg(&xdr, &msg)) {
   1076 		if ((msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
   1077 		    (msg.acpted_rply.ar_stat == SUCCESS)) {
   1078 			ypdb = xid2ypdb(msg.rm_xid);
   1079 			if (ypdb != NULL)
   1080 				rpc_received(ypdb->dom_domain, &raddr, 0);
   1081 		}
   1082 	}
   1083 	xdr.x_op = XDR_FREE;
   1084 	msg.acpted_rply.ar_results.proc = xdr_void;
   1085 	xdr_destroy(&xdr);
   1086 
   1087 	return RPC_SUCCESS;
   1088 }
   1089 
   1090 /*
   1091  * LOOPBACK IS MORE IMPORTANT: PUT IN HACK
   1092  */
   1093 void
   1094 rpc_received(dom, raddrp, force)
   1095 	char *dom;
   1096 	struct sockaddr_in *raddrp;
   1097 	int force;
   1098 {
   1099 	struct _dom_binding *ypdb;
   1100 	struct iovec iov[2];
   1101 	struct ypbind_resp ybr;
   1102 	int fd;
   1103 
   1104 #ifdef DEBUG
   1105 	if (debug)
   1106 		printf("returned from %s about %s\n",
   1107 		    inet_ntoa(raddrp->sin_addr), dom);
   1108 #endif
   1109 
   1110 	if (dom == NULL)
   1111 		return;
   1112 
   1113 	if (_yp_invalid_domain(dom))
   1114 		return;
   1115 
   1116 		/* don't support insecure servers by default */
   1117 	if (!insecure && ntohs(raddrp->sin_port) >= IPPORT_RESERVED)
   1118 		return;
   1119 
   1120 	for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
   1121 		if (!strcmp(ypdb->dom_domain, dom))
   1122 			break;
   1123 
   1124 	if (ypdb == NULL) {
   1125 		if (force == 0)
   1126 			return;
   1127 		ypdb = makebinding(dom);
   1128 		ypdb->dom_lockfd = -1;
   1129 		ypdb->dom_pnext = ypbindlist;
   1130 		ypbindlist = ypdb;
   1131 	}
   1132 
   1133 	/* soft update, alive */
   1134 	if (ypdb->dom_alive == 1 && force == 0) {
   1135 		if (!memcmp(&ypdb->dom_server_addr, raddrp,
   1136 			    sizeof ypdb->dom_server_addr)) {
   1137 			ypdb->dom_alive = 1;
   1138 			/* recheck binding in 60 sec */
   1139 			ypdb->dom_check_t = time(NULL) + 60;
   1140 		}
   1141 		return;
   1142 	}
   1143 
   1144 	(void) memcpy(&ypdb->dom_server_addr, raddrp,
   1145 	    sizeof ypdb->dom_server_addr);
   1146 	/* recheck binding in 60 seconds */
   1147 	ypdb->dom_check_t = time(NULL) + 60;
   1148 	ypdb->dom_vers = YPVERS;
   1149 	ypdb->dom_alive = 1;
   1150 
   1151 	if (ypdb->dom_lockfd != -1)
   1152 		(void) close(ypdb->dom_lockfd);
   1153 
   1154 	if ((fd = makelock(ypdb)) == -1)
   1155 		return;
   1156 
   1157 	/*
   1158 	 * ok, if BINDINGDIR exists, and we can create the binding file,
   1159 	 * then write to it..
   1160 	 */
   1161 	ypdb->dom_lockfd = fd;
   1162 
   1163 	iov[0].iov_base = (caddr_t)&(udptransp->xp_port);
   1164 	iov[0].iov_len = sizeof udptransp->xp_port;
   1165 	iov[1].iov_base = (caddr_t)&ybr;
   1166 	iov[1].iov_len = sizeof ybr;
   1167 
   1168 	(void) memset(&ybr, 0, sizeof ybr);
   1169 	ybr.ypbind_status = YPBIND_SUCC_VAL;
   1170 	ybr.ypbind_respbody.ypbind_bindinfo.ypbind_binding_addr =
   1171 	    raddrp->sin_addr;
   1172 	ybr.ypbind_respbody.ypbind_bindinfo.ypbind_binding_port =
   1173 	    raddrp->sin_port;
   1174 
   1175 	if (writev(ypdb->dom_lockfd, iov, 2) !=
   1176 	    iov[0].iov_len + iov[1].iov_len) {
   1177 		warnx("writev");
   1178 		(void) close(ypdb->dom_lockfd);
   1179 		removelock(ypdb);
   1180 		ypdb->dom_lockfd = -1;
   1181 	}
   1182 }
   1183 
   1184 static struct _dom_binding *
   1185 xid2ypdb(xid)
   1186 	u_int32_t xid;
   1187 {
   1188 	struct _dom_binding *ypdb;
   1189 
   1190 	for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
   1191 		if (ypdb->dom_xid == xid)
   1192 			break;
   1193 	return (ypdb);
   1194 }
   1195 
   1196 static u_int32_t
   1197 unique_xid(ypdb)
   1198 	struct _dom_binding *ypdb;
   1199 {
   1200 	u_int32_t tmp_xid;
   1201 
   1202 	tmp_xid = (u_int32_t)(((u_long)ypdb) & 0xffffffff);
   1203 	while (xid2ypdb(tmp_xid) != NULL)
   1204 		tmp_xid++;
   1205 
   1206 	return tmp_xid;
   1207 }
   1208