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ypbind.c revision 1.51
      1 /*	$NetBSD: ypbind.c,v 1.51 2004/01/05 23:23:39 jmmv 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  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
     17  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
     20  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 #ifndef LINT
     31 __RCSID("$NetBSD: ypbind.c,v 1.51 2004/01/05 23:23:39 jmmv Exp $");
     32 #endif
     33 
     34 #include <sys/param.h>
     35 #include <sys/types.h>
     36 #include <sys/ioctl.h>
     37 #include <sys/signal.h>
     38 #include <sys/socket.h>
     39 #include <sys/file.h>
     40 #include <sys/uio.h>
     41 #include <sys/syslog.h>
     42 #include <sys/stat.h>
     43 #include <fcntl.h>
     44 #include <limits.h>
     45 #include <stdio.h>
     46 #include <stdlib.h>
     47 #include <errno.h>
     48 #include <syslog.h>
     49 #include <stdarg.h>
     50 #include <ctype.h>
     51 #include <dirent.h>
     52 #include <netdb.h>
     53 #include <string.h>
     54 #include <err.h>
     55 #include <rpc/rpc.h>
     56 #include <rpc/xdr.h>
     57 #include <net/if.h>
     58 #include <arpa/inet.h>
     59 #include <rpc/pmap_clnt.h>
     60 #include <rpc/pmap_prot.h>
     61 #include <rpc/pmap_rmt.h>
     62 #include <unistd.h>
     63 #include <util.h>
     64 #include <rpcsvc/yp_prot.h>
     65 #include <rpcsvc/ypclnt.h>
     66 #include <ifaddrs.h>
     67 
     68 #include "pathnames.h"
     69 
     70 #ifndef O_SHLOCK
     71 #define O_SHLOCK 0
     72 #endif
     73 
     74 #define BUFSIZE		1400
     75 
     76 #define YPSERVERSSUFF	".ypservers"
     77 #define BINDINGDIR	(_PATH_VAR_YP "binding")
     78 
     79 struct _dom_binding {
     80 	struct _dom_binding *dom_pnext;
     81 	char dom_domain[YPMAXDOMAIN + 1];
     82 	struct sockaddr_in dom_server_addr;
     83 	int dom_socket;
     84 	CLIENT *dom_client;
     85 	long dom_vers;
     86 	time_t dom_check_t;
     87 	time_t dom_ask_t;
     88 	int dom_lockfd;
     89 	int dom_alive;
     90 	u_int32_t dom_xid;
     91 };
     92 
     93 static char *domainname;
     94 
     95 static struct _dom_binding *ypbindlist;
     96 static int check;
     97 
     98 typedef enum {
     99 	YPBIND_DIRECT, YPBIND_BROADCAST, YPBIND_SETLOCAL, YPBIND_SETALL
    100 } ypbind_mode_t;
    101 
    102 ypbind_mode_t ypbindmode;
    103 
    104 /*
    105  * If ypbindmode is YPBIND_SETLOCAL or YPBIND_SETALL, this indicates
    106  * whether or not we've been "ypset".  If we haven't, we behave like
    107  * YPBIND_BROADCAST.  If we have, we behave like YPBIND_DIRECT.
    108  */
    109 int been_ypset;
    110 
    111 #ifdef DEBUG
    112 static int debug;
    113 #endif
    114 
    115 static int insecure;
    116 static int rpcsock, pingsock;
    117 static struct rmtcallargs rmtca;
    118 static struct rmtcallres rmtcr;
    119 static bool_t rmtcr_outval;
    120 static u_long rmtcr_port;
    121 static SVCXPRT *udptransp, *tcptransp;
    122 
    123 int	_yp_invalid_domain(const char *);		/* from libc */
    124 int	main(int, char *[]);
    125 
    126 static void usage(void);
    127 static void yp_log(int, const char *, ...)
    128 	__attribute__((__format__(__printf__, 2, 3)));
    129 static struct _dom_binding *makebinding(const char *);
    130 static int makelock(struct _dom_binding *);
    131 static void removelock(struct _dom_binding *);
    132 static void *ypbindproc_null_2(SVCXPRT *, void *);
    133 static void *ypbindproc_domain_2(SVCXPRT *, void *);
    134 static void *ypbindproc_setdom_2(SVCXPRT *, void *);
    135 static void ypbindprog_2(struct svc_req *, SVCXPRT *);
    136 static void checkwork(void);
    137 static int ping(struct _dom_binding *);
    138 static int nag_servers(struct _dom_binding *);
    139 static enum clnt_stat handle_replies(void);
    140 static enum clnt_stat handle_ping(void);
    141 static void rpc_received(char *, struct sockaddr_in *, int);
    142 static struct _dom_binding *xid2ypdb(u_int32_t);
    143 static u_int32_t unique_xid(struct _dom_binding *);
    144 static int broadcast(char *, int);
    145 static int direct(char *, int);
    146 static int direct_set(char *, int, struct _dom_binding *);
    147 
    148 static void
    149 usage(void)
    150 {
    151 	char *opt = "";
    152 #ifdef DEBUG
    153 	opt = " [-d]";
    154 #endif
    155 
    156 	(void)fprintf(stderr,
    157 	    "usage: %s [-broadcast] [-insecure] [-ypset] [-ypsetme] %s\n",
    158 	    getprogname(), opt);
    159 	exit(1);
    160 }
    161 
    162 static void
    163 yp_log(int pri, const char *fmt, ...)
    164 {
    165 	va_list ap;
    166 
    167 	va_start(ap, fmt);
    168 
    169 #if defined(DEBUG)
    170 	if (debug)
    171 		vfprintf(stderr, fmt, ap);
    172 	else
    173 #endif
    174 		vsyslog(pri, fmt, ap);
    175 	va_end(ap);
    176 }
    177 
    178 static struct _dom_binding *
    179 makebinding(const char *dm)
    180 {
    181 	struct _dom_binding *ypdb;
    182 
    183 	if ((ypdb = (struct _dom_binding *)malloc(sizeof *ypdb)) == NULL) {
    184 		yp_log(LOG_ERR, "makebinding");
    185 		exit(1);
    186 	}
    187 
    188 	(void)memset(ypdb, 0, sizeof *ypdb);
    189 	(void)strncpy(ypdb->dom_domain, dm, sizeof ypdb->dom_domain);
    190 	ypdb->dom_domain[sizeof(ypdb->dom_domain) - 1] = '\0';
    191 	return ypdb;
    192 }
    193 
    194 static int
    195 makelock(struct _dom_binding *ypdb)
    196 {
    197 	int fd;
    198 	char path[MAXPATHLEN];
    199 
    200 	(void)snprintf(path, sizeof(path), "%s/%s.%ld", BINDINGDIR,
    201 	    ypdb->dom_domain, ypdb->dom_vers);
    202 
    203 	if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) {
    204 		(void)mkdir(BINDINGDIR, 0755);
    205 		if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1)
    206 			return -1;
    207 	}
    208 
    209 #if O_SHLOCK == 0
    210 	(void)flock(fd, LOCK_SH);
    211 #endif
    212 	return fd;
    213 }
    214 
    215 static void
    216 removelock(struct _dom_binding *ypdb)
    217 {
    218 	char path[MAXPATHLEN];
    219 
    220 	(void)snprintf(path, sizeof(path), "%s/%s.%ld",
    221 	    BINDINGDIR, ypdb->dom_domain, ypdb->dom_vers);
    222 	(void)unlink(path);
    223 }
    224 
    225 static void *
    226 ypbindproc_null_2(SVCXPRT *transp, void *argp)
    227 {
    228 	static char res;
    229 
    230 #ifdef DEBUG
    231 	if (debug)
    232 		printf("ypbindproc_null_2\n");
    233 #endif
    234 	(void)memset(&res, 0, sizeof(res));
    235 	return (void *)&res;
    236 }
    237 
    238 static void *
    239 ypbindproc_domain_2(SVCXPRT *transp, void *argp)
    240 {
    241 	static struct ypbind_resp res;
    242 	struct _dom_binding *ypdb;
    243 	char *arg = *(char **) argp;
    244 	time_t now;
    245 	int count;
    246 
    247 #ifdef DEBUG
    248 	if (debug)
    249 		printf("ypbindproc_domain_2 %s\n", arg);
    250 #endif
    251 	if (_yp_invalid_domain(arg))
    252 		return NULL;
    253 
    254 	(void)memset(&res, 0, sizeof res);
    255 	res.ypbind_status = YPBIND_FAIL_VAL;
    256 
    257 	for (count = 0, ypdb = ypbindlist;
    258 	    ypdb != NULL;
    259 	    ypdb = ypdb->dom_pnext, count++) {
    260 		if (count > 100)
    261 			return NULL;		/* prevent denial of service */
    262 		if (!strcmp(ypdb->dom_domain, arg))
    263 			break;
    264 	}
    265 
    266 	if (ypdb == NULL) {
    267 		ypdb = makebinding(arg);
    268 		ypdb->dom_vers = YPVERS;
    269 		ypdb->dom_alive = 0;
    270 		ypdb->dom_lockfd = -1;
    271 		removelock(ypdb);
    272 		ypdb->dom_xid = unique_xid(ypdb);
    273 		ypdb->dom_pnext = ypbindlist;
    274 		ypbindlist = ypdb;
    275 		check++;
    276 #ifdef DEBUG
    277 		if (debug)
    278 			printf("unknown domain %s\n", arg);
    279 #endif
    280 		return NULL;
    281 	}
    282 
    283 	if (ypdb->dom_alive == 0) {
    284 #ifdef DEBUG
    285 		if (debug)
    286 			printf("dead domain %s\n", arg);
    287 #endif
    288 		return NULL;
    289 	}
    290 
    291 #ifdef HEURISTIC
    292 	time(&now);
    293 	if (now < ypdb->dom_ask_t + 5) {
    294 		/*
    295 		 * Hmm. More than 2 requests in 5 seconds have indicated
    296 		 * that my binding is possibly incorrect.
    297 		 * Ok, do an immediate poll of the server.
    298 		 */
    299 		if (ypdb->dom_check_t >= now) {
    300 			/* don't flood it */
    301 			ypdb->dom_check_t = 0;
    302 			check++;
    303 		}
    304 	}
    305 	ypdb->dom_ask_t = now;
    306 #endif
    307 
    308 	res.ypbind_status = YPBIND_SUCC_VAL;
    309 	res.ypbind_respbody.ypbind_bindinfo.ypbind_binding_addr.s_addr =
    310 		ypdb->dom_server_addr.sin_addr.s_addr;
    311 	res.ypbind_respbody.ypbind_bindinfo.ypbind_binding_port =
    312 		ypdb->dom_server_addr.sin_port;
    313 #ifdef DEBUG
    314 	if (debug)
    315 		printf("domain %s at %s/%d\n", ypdb->dom_domain,
    316 		    inet_ntoa(ypdb->dom_server_addr.sin_addr),
    317 		    ntohs(ypdb->dom_server_addr.sin_port));
    318 #endif
    319 	return &res;
    320 }
    321 
    322 static void *
    323 ypbindproc_setdom_2(SVCXPRT *transp, void *argp)
    324 {
    325 	struct ypbind_setdom *sd = argp;
    326 	struct sockaddr_in *fromsin, bindsin;
    327 	static bool_t res;
    328 
    329 #ifdef DEBUG
    330 	if (debug)
    331 		printf("ypbindproc_setdom_2 %s\n", inet_ntoa(bindsin.sin_addr));
    332 #endif
    333 	(void)memset(&res, 0, sizeof(res));
    334 	fromsin = svc_getcaller(transp);
    335 
    336 	switch (ypbindmode) {
    337 	case YPBIND_SETLOCAL:
    338 		if (fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) {
    339 #ifdef DEBUG
    340 			if (debug)
    341 				printf("ypset from %s denied\n",
    342 				    inet_ntoa(fromsin->sin_addr));
    343 #endif
    344 			return NULL;
    345 		}
    346 		/* FALLTHROUGH */
    347 
    348 	case YPBIND_SETALL:
    349 		been_ypset = 1;
    350 		break;
    351 
    352 	case YPBIND_DIRECT:
    353 	case YPBIND_BROADCAST:
    354 	default:
    355 #ifdef DEBUG
    356 		if (debug)
    357 			printf("ypset denied\n");
    358 #endif
    359 		return NULL;
    360 	}
    361 
    362 	if (ntohs(fromsin->sin_port) >= IPPORT_RESERVED) {
    363 #ifdef DEBUG
    364 		if (debug)
    365 			printf("ypset from unprivileged port denied\n");
    366 #endif
    367 		return &res;
    368 	}
    369 
    370 	if (sd->ypsetdom_vers != YPVERS) {
    371 #ifdef DEBUG
    372 		if (debug)
    373 			printf("ypset with wrong version denied\n");
    374 #endif
    375 		return &res;
    376 	}
    377 
    378 	(void)memset(&bindsin, 0, sizeof bindsin);
    379 	bindsin.sin_family = AF_INET;
    380 	bindsin.sin_len = sizeof(bindsin);
    381 	bindsin.sin_addr = sd->ypsetdom_addr;
    382 	bindsin.sin_port = sd->ypsetdom_port;
    383 	rpc_received(sd->ypsetdom_domain, &bindsin, 1);
    384 
    385 #ifdef DEBUG
    386 	if (debug)
    387 		printf("ypset to %s succeeded\n", inet_ntoa(bindsin.sin_addr));
    388 #endif
    389 	res = 1;
    390 	return &res;
    391 }
    392 
    393 static void
    394 ypbindprog_2(struct svc_req *rqstp, register SVCXPRT *transp)
    395 {
    396 	union {
    397 		char ypbindproc_domain_2_arg[YPMAXDOMAIN + 1];
    398 		struct ypbind_setdom ypbindproc_setdom_2_arg;
    399 	} argument;
    400 	struct authunix_parms *creds;
    401 	char *result;
    402 	xdrproc_t xdr_argument, xdr_result;
    403 	void *(*local)(SVCXPRT *, void *);
    404 
    405 	switch (rqstp->rq_proc) {
    406 	case YPBINDPROC_NULL:
    407 		xdr_argument = xdr_void;
    408 		xdr_result = xdr_void;
    409 		local = ypbindproc_null_2;
    410 		break;
    411 
    412 	case YPBINDPROC_DOMAIN:
    413 		xdr_argument = xdr_ypdomain_wrap_string;
    414 		xdr_result = xdr_ypbind_resp;
    415 		local = ypbindproc_domain_2;
    416 		break;
    417 
    418 	case YPBINDPROC_SETDOM:
    419 		switch (rqstp->rq_cred.oa_flavor) {
    420 		case AUTH_UNIX:
    421 			creds = (struct authunix_parms *)rqstp->rq_clntcred;
    422 			if (creds->aup_uid != 0) {
    423 				svcerr_auth(transp, AUTH_BADCRED);
    424 				return;
    425 			}
    426 			break;
    427 		default:
    428 			svcerr_auth(transp, AUTH_TOOWEAK);
    429 			return;
    430 		}
    431 
    432 		xdr_argument = xdr_ypbind_setdom;
    433 		xdr_result = xdr_void;
    434 		local = ypbindproc_setdom_2;
    435 		break;
    436 
    437 	default:
    438 		svcerr_noproc(transp);
    439 		return;
    440 	}
    441 	(void)memset(&argument, 0, sizeof(argument));
    442 	if (!svc_getargs(transp, xdr_argument, (caddr_t)&argument)) {
    443 		svcerr_decode(transp);
    444 		return;
    445 	}
    446 	result = (*local)(transp, &argument);
    447 	if (result != NULL && !svc_sendreply(transp, xdr_result, result)) {
    448 		svcerr_systemerr(transp);
    449 	}
    450 	return;
    451 }
    452 
    453 int
    454 main(int argc, char *argv[])
    455 {
    456 	struct timeval tv;
    457 	fd_set fdsr;
    458 	int width, lockfd;
    459 	int evil = 0, one;
    460 	char pathname[MAXPATHLEN];
    461 	struct stat st;
    462 
    463 	yp_get_default_domain(&domainname);
    464 	if (domainname[0] == '\0')
    465 		errx(1, "Domainname not set. Aborting.");
    466 
    467 	/*
    468 	 * Per traditional ypbind(8) semantics, if a ypservers
    469 	 * file does not exist, we default to broadcast mode.
    470 	 * If the file does exist, we default to direct mode.
    471 	 * Note that we can still override direct mode by passing
    472 	 * the -broadcast flag.
    473 	 */
    474 	snprintf(pathname, sizeof(pathname), "%s/%s%s", BINDINGDIR,
    475 	    domainname, YPSERVERSSUFF);
    476 	if (stat(pathname, &st) < 0) {
    477 #ifdef DEBUG
    478 		if (debug)
    479 			fprintf(stderr,
    480 			    "%s does not exist, defaulting to broadcast\n",
    481 			    pathname);
    482 #endif
    483 		ypbindmode = YPBIND_BROADCAST;
    484 	} else
    485 		ypbindmode = YPBIND_DIRECT;
    486 
    487 	while (--argc) {
    488 		++argv;
    489 		if (!strcmp("-insecure", *argv))
    490 			insecure = 1;
    491 		else if (!strcmp("-ypset", *argv))
    492 			ypbindmode = YPBIND_SETALL;
    493 		else if (!strcmp("-ypsetme", *argv))
    494 			ypbindmode = YPBIND_SETLOCAL;
    495 		else if (!strcmp("-broadcast", *argv))
    496 			ypbindmode = YPBIND_BROADCAST;
    497 #ifdef DEBUG
    498 		else if (!strcmp("-d", *argv))
    499 			debug++;
    500 #endif
    501 		else
    502 			usage();
    503 	}
    504 
    505 	/* initialise syslog */
    506 	openlog("ypbind", LOG_PERROR | LOG_PID, LOG_DAEMON);
    507 
    508 	/* blow away everything in BINDINGDIR */
    509 
    510 	lockfd = open(_PATH_YPBIND_LOCK, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644);
    511 	if (lockfd == -1)
    512 		err(1, "Cannot create %s", _PATH_YPBIND_LOCK);
    513 
    514 #if O_SHLOCK == 0
    515 	(void)flock(lockfd, LOCK_SH);
    516 #endif
    517 
    518 	(void)pmap_unset(YPBINDPROG, YPBINDVERS);
    519 
    520 	udptransp = svcudp_create(RPC_ANYSOCK);
    521 	if (udptransp == NULL)
    522 		errx(1, "Cannot create udp service.");
    523 
    524 	if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
    525 	    IPPROTO_UDP))
    526 		errx(1, "Unable to register (YPBINDPROG, YPBINDVERS, udp).");
    527 
    528 	tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0);
    529 	if (tcptransp == NULL)
    530 		errx(1, "Cannot create tcp service.");
    531 
    532 	if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
    533 	    IPPROTO_TCP))
    534 		errx(1, "Unable to register (YPBINDPROG, YPBINDVERS, tcp).");
    535 
    536 	/* XXX use SOCK_STREAM for direct queries? */
    537 	if ((rpcsock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
    538 		err(1, "rpc socket");
    539 	if ((pingsock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
    540 		err(1, "ping socket");
    541 
    542 	(void)fcntl(rpcsock, F_SETFL, fcntl(rpcsock, F_GETFL, 0) | FNDELAY);
    543 	(void)fcntl(pingsock, F_SETFL, fcntl(pingsock, F_GETFL, 0) | FNDELAY);
    544 
    545 	one = 1;
    546 	(void)setsockopt(rpcsock, SOL_SOCKET, SO_BROADCAST, &one, sizeof(one));
    547 	rmtca.prog = YPPROG;
    548 	rmtca.vers = YPVERS;
    549 	rmtca.proc = YPPROC_DOMAIN_NONACK;
    550 	rmtca.xdr_args = NULL;		/* set at call time */
    551 	rmtca.args_ptr = NULL;		/* set at call time */
    552 	rmtcr.port_ptr = &rmtcr_port;
    553 	rmtcr.xdr_results = xdr_bool;
    554 	rmtcr.results_ptr = (caddr_t)&rmtcr_outval;
    555 
    556 	if (_yp_invalid_domain(domainname))
    557 		errx(1, "bad domainname: %s", domainname);
    558 
    559 	/* build initial domain binding, make it "unsuccessful" */
    560 	ypbindlist = makebinding(domainname);
    561 	ypbindlist->dom_vers = YPVERS;
    562 	ypbindlist->dom_alive = 0;
    563 	ypbindlist->dom_lockfd = -1;
    564 	removelock(ypbindlist);
    565 
    566 	checkwork();
    567 
    568 	for (;;) {
    569 		width = svc_maxfd;
    570 		if (rpcsock > width)
    571 			width = rpcsock;
    572 		if (pingsock > width)
    573 			width = pingsock;
    574 		width++;
    575 		fdsr = svc_fdset;
    576 		FD_SET(rpcsock, &fdsr);
    577 		FD_SET(pingsock, &fdsr);
    578 		tv.tv_sec = 1;
    579 		tv.tv_usec = 0;
    580 
    581 		switch (select(width, &fdsr, NULL, NULL, &tv)) {
    582 		case 0:
    583 			checkwork();
    584 			break;
    585 		case -1:
    586 			yp_log(LOG_WARNING, "select: %m");
    587 			break;
    588 		default:
    589 			if (FD_ISSET(rpcsock, &fdsr))
    590 				handle_replies();
    591 			if (FD_ISSET(pingsock, &fdsr))
    592 				handle_ping();
    593 			svc_getreqset(&fdsr);
    594 			if (check)
    595 				checkwork();
    596 			break;
    597 		}
    598 
    599 		if (!evil && ypbindlist->dom_alive) {
    600 			evil = 1;
    601 #ifdef DEBUG
    602 			if (!debug)
    603 #endif
    604 				daemon(0, 0);
    605 			pidfile(NULL);
    606 		}
    607 	}
    608 }
    609 
    610 /*
    611  * State transition is done like this:
    612  *
    613  * STATE	EVENT		ACTION			NEWSTATE	TIMEOUT
    614  * no binding	timeout		broadcast 		no binding	5 sec
    615  * no binding	answer		--			binding		60 sec
    616  * binding	timeout		ping server		checking	5 sec
    617  * checking	timeout		ping server + broadcast	checking	5 sec
    618  * checking	answer		--			binding		60 sec
    619  */
    620 void
    621 checkwork(void)
    622 {
    623 	struct _dom_binding *ypdb;
    624 	time_t t;
    625 
    626 	check = 0;
    627 
    628 	time(&t);
    629 	for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
    630 		if (ypdb->dom_check_t < t) {
    631 			if (ypdb->dom_alive == 1)
    632 				ping(ypdb);
    633 			else
    634 				nag_servers(ypdb);
    635 			time(&t);
    636 			ypdb->dom_check_t = t + 5;
    637 		}
    638 	}
    639 }
    640 
    641 int
    642 ping(struct _dom_binding *ypdb)
    643 {
    644 	char *dom = ypdb->dom_domain;
    645 	struct rpc_msg msg;
    646 	char buf[BUFSIZE];
    647 	enum clnt_stat st;
    648 	int outlen;
    649 	AUTH *rpcua;
    650 	XDR xdr;
    651 
    652 	(void)memset(&xdr, 0, sizeof xdr);
    653 	(void)memset(&msg, 0, sizeof msg);
    654 
    655 	rpcua = authunix_create_default();
    656 	if (rpcua == NULL) {
    657 #ifdef DEBUG
    658 		if (debug)
    659 			printf("cannot get unix auth\n");
    660 #endif
    661 		return RPC_SYSTEMERROR;
    662 	}
    663 
    664 	msg.rm_direction = CALL;
    665 	msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
    666 	msg.rm_call.cb_prog = YPPROG;
    667 	msg.rm_call.cb_vers = YPVERS;
    668 	msg.rm_call.cb_proc = YPPROC_DOMAIN_NONACK;
    669 	msg.rm_call.cb_cred = rpcua->ah_cred;
    670 	msg.rm_call.cb_verf = rpcua->ah_verf;
    671 
    672 	msg.rm_xid = ypdb->dom_xid;
    673 	xdrmem_create(&xdr, buf, sizeof buf, XDR_ENCODE);
    674 	if (!xdr_callmsg(&xdr, &msg)) {
    675 		st = RPC_CANTENCODEARGS;
    676 		AUTH_DESTROY(rpcua);
    677 		return st;
    678 	}
    679 	if (!xdr_ypdomain_wrap_string(&xdr, &dom)) {
    680 		st = RPC_CANTENCODEARGS;
    681 		AUTH_DESTROY(rpcua);
    682 		return st;
    683 	}
    684 	outlen = (int)xdr_getpos(&xdr);
    685 	xdr_destroy(&xdr);
    686 	if (outlen < 1) {
    687 		st = RPC_CANTENCODEARGS;
    688 		AUTH_DESTROY(rpcua);
    689 		return st;
    690 	}
    691 	AUTH_DESTROY(rpcua);
    692 
    693 	ypdb->dom_alive = 2;
    694 	if (sendto(pingsock, buf, outlen, 0,
    695 		   (struct sockaddr *)&ypdb->dom_server_addr,
    696 		   sizeof ypdb->dom_server_addr) == -1)
    697 		yp_log(LOG_WARNING, "ping: sendto: %m");
    698 	return 0;
    699 
    700 }
    701 
    702 static int
    703 nag_servers(struct _dom_binding *ypdb)
    704 {
    705 	char *dom = ypdb->dom_domain;
    706 	struct rpc_msg msg;
    707 	char buf[BUFSIZE];
    708 	enum clnt_stat st;
    709 	int outlen;
    710 	AUTH *rpcua;
    711 	XDR xdr;
    712 
    713 	rmtca.xdr_args = xdr_ypdomain_wrap_string;
    714 	rmtca.args_ptr = (char *)&dom;
    715 
    716 	(void)memset(&xdr, 0, sizeof xdr);
    717 	(void)memset(&msg, 0, sizeof msg);
    718 
    719 	rpcua = authunix_create_default();
    720 	if (rpcua == NULL) {
    721 #ifdef DEBUG
    722 		if (debug)
    723 			printf("cannot get unix auth\n");
    724 #endif
    725 		return RPC_SYSTEMERROR;
    726 	}
    727 	msg.rm_direction = CALL;
    728 	msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
    729 	msg.rm_call.cb_prog = PMAPPROG;
    730 	msg.rm_call.cb_vers = PMAPVERS;
    731 	msg.rm_call.cb_proc = PMAPPROC_CALLIT;
    732 	msg.rm_call.cb_cred = rpcua->ah_cred;
    733 	msg.rm_call.cb_verf = rpcua->ah_verf;
    734 
    735 	msg.rm_xid = ypdb->dom_xid;
    736 	xdrmem_create(&xdr, buf, sizeof buf, XDR_ENCODE);
    737 	if (!xdr_callmsg(&xdr, &msg)) {
    738 		st = RPC_CANTENCODEARGS;
    739 		AUTH_DESTROY(rpcua);
    740 		return st;
    741 	}
    742 	if (!xdr_rmtcall_args(&xdr, &rmtca)) {
    743 		st = RPC_CANTENCODEARGS;
    744 		AUTH_DESTROY(rpcua);
    745 		return st;
    746 	}
    747 	outlen = (int)xdr_getpos(&xdr);
    748 	xdr_destroy(&xdr);
    749 	if (outlen < 1) {
    750 		st = RPC_CANTENCODEARGS;
    751 		AUTH_DESTROY(rpcua);
    752 		return st;
    753 	}
    754 	AUTH_DESTROY(rpcua);
    755 
    756 	if (ypdb->dom_lockfd != -1) {
    757 		(void)close(ypdb->dom_lockfd);
    758 		ypdb->dom_lockfd = -1;
    759 		removelock(ypdb);
    760 	}
    761 
    762 	if (ypdb->dom_alive == 2) {
    763 		/*
    764 		 * This resolves the following situation:
    765 		 * ypserver on other subnet was once bound,
    766 		 * but rebooted and is now using a different port
    767 		 */
    768 		struct sockaddr_in bindsin;
    769 
    770 		memset(&bindsin, 0, sizeof bindsin);
    771 		bindsin.sin_family = AF_INET;
    772 		bindsin.sin_len = sizeof(bindsin);
    773 		bindsin.sin_port = htons(PMAPPORT);
    774 		bindsin.sin_addr = ypdb->dom_server_addr.sin_addr;
    775 
    776 		if (sendto(rpcsock, buf, outlen, 0, (struct sockaddr *)&bindsin,
    777 			   sizeof bindsin) == -1)
    778 			yp_log(LOG_WARNING, "broadcast: sendto: %m");
    779 	}
    780 
    781 	switch (ypbindmode) {
    782 	case YPBIND_SETALL:
    783 	case YPBIND_SETLOCAL:
    784 		if (been_ypset)
    785 			return direct_set(buf, outlen, ypdb);
    786 		/* FALLTHROUGH */
    787 
    788 	case YPBIND_BROADCAST:
    789 		return broadcast(buf, outlen);
    790 
    791 	case YPBIND_DIRECT:
    792 		return direct(buf, outlen);
    793 	}
    794 
    795 	return -1;
    796 }
    797 
    798 static int
    799 broadcast(char *buf, int outlen)
    800 {
    801 	struct ifaddrs *ifap, *ifa;
    802 	struct sockaddr_in bindsin;
    803 	struct in_addr in;
    804 
    805 	memset(&bindsin, 0, sizeof bindsin);
    806 	bindsin.sin_family = AF_INET;
    807 	bindsin.sin_len = sizeof(bindsin);
    808 	bindsin.sin_port = htons(PMAPPORT);
    809 
    810 	if (getifaddrs(&ifap) != 0) {
    811 		yp_log(LOG_WARNING, "broadcast: getifaddrs: %m");
    812 		return (-1);
    813 	}
    814 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
    815 		if (ifa->ifa_addr->sa_family != AF_INET)
    816 			continue;
    817 		if ((ifa->ifa_flags & IFF_UP) == 0)
    818 			continue;
    819 
    820 		switch (ifa->ifa_flags & (IFF_LOOPBACK | IFF_BROADCAST)) {
    821 		case IFF_BROADCAST:
    822 			if (!ifa->ifa_broadaddr)
    823 				continue;
    824 			if (ifa->ifa_broadaddr->sa_family != AF_INET)
    825 				continue;
    826 			in = ((struct sockaddr_in *)ifa->ifa_broadaddr)->sin_addr;
    827 			break;
    828 		case IFF_LOOPBACK:
    829 			in = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
    830 			break;
    831 		default:
    832 			continue;
    833 		}
    834 
    835 		bindsin.sin_addr = in;
    836 		if (sendto(rpcsock, buf, outlen, 0, (struct sockaddr *)&bindsin,
    837 			   bindsin.sin_len) == -1)
    838 			yp_log(LOG_WARNING, "broadcast: sendto: %m");
    839 	}
    840 	freeifaddrs(ifap);
    841 	return (0);
    842 }
    843 
    844 static int
    845 direct(char *buf, int outlen)
    846 {
    847 	static FILE *df;
    848 	static char ypservers_path[MAXPATHLEN];
    849 	char line[_POSIX2_LINE_MAX];
    850 	char *p;
    851 	struct hostent *hp;
    852 	struct sockaddr_in bindsin;
    853 	int i, count = 0;
    854 
    855 	if (df)
    856 		rewind(df);
    857 	else {
    858 		snprintf(ypservers_path, sizeof(ypservers_path),
    859 		    "%s/%s%s", BINDINGDIR, domainname, YPSERVERSSUFF);
    860 		df = fopen(ypservers_path, "r");
    861 		if (df == NULL) {
    862 			yp_log(LOG_ERR, "%s: ", ypservers_path);
    863 			exit(1);
    864 		}
    865 	}
    866 
    867 	memset(&bindsin, 0, sizeof bindsin);
    868 	bindsin.sin_family = AF_INET;
    869 	bindsin.sin_len = sizeof(bindsin);
    870 	bindsin.sin_port = htons(PMAPPORT);
    871 
    872 	while(fgets(line, sizeof(line), df) != NULL) {
    873 		/* skip lines that are too big */
    874 		p = strchr(line, '\n');
    875 		if (p == NULL) {
    876 			int c;
    877 
    878 			while ((c = getc(df)) != '\n' && c != EOF)
    879 				;
    880 			continue;
    881 		}
    882 		*p = '\0';
    883 		p = line;
    884 		while (isspace(*p))
    885 			p++;
    886 		if (*p == '#')
    887 			continue;
    888 		hp = gethostbyname(p);
    889 		if (!hp) {
    890 			yp_log(LOG_WARNING, "%s: %s", p, hstrerror(h_errno));
    891 			continue;
    892 		}
    893 		/* step through all addresses in case first is unavailable */
    894 		for (i = 0; hp->h_addr_list[i]; i++) {
    895 			memmove(&bindsin.sin_addr, hp->h_addr_list[0],
    896 			    hp->h_length);
    897 			if (sendto(rpcsock, buf, outlen, 0,
    898 			    (struct sockaddr *)&bindsin, sizeof bindsin) < 0) {
    899 				yp_log(LOG_WARNING, "direct: sendto: %m");
    900 				continue;
    901 			} else
    902 				count++;
    903 		}
    904 	}
    905 	if (!count) {
    906 		yp_log(LOG_WARNING, "no contactable servers found in %s",
    907 		    ypservers_path);
    908 		return -1;
    909 	}
    910 	return 0;
    911 }
    912 
    913 static int
    914 direct_set(char *buf, int outlen, struct _dom_binding *ypdb)
    915 {
    916 	struct sockaddr_in bindsin;
    917 	char path[MAXPATHLEN];
    918 	struct iovec iov[2];
    919 	struct ypbind_resp ybr;
    920 	SVCXPRT dummy_svc;
    921 	int fd, bytes;
    922 
    923 	/*
    924 	 * Gack, we lose if binding file went away.  We reset
    925 	 * "been_set" if this happens, otherwise we'll never
    926 	 * bind again.
    927 	 */
    928 	snprintf(path, sizeof(path), "%s/%s.%ld", BINDINGDIR,
    929 	    ypdb->dom_domain, ypdb->dom_vers);
    930 
    931 	if ((fd = open(path, O_SHLOCK|O_RDONLY, 0644)) == -1) {
    932 		yp_log(LOG_WARNING, "%s: %m", path);
    933 		been_ypset = 0;
    934 		return -1;
    935 	}
    936 
    937 #if O_SHLOCK == 0
    938 	(void)flock(fd, LOCK_SH);
    939 #endif
    940 
    941 	/* Read the binding file... */
    942 	iov[0].iov_base = (caddr_t)&(dummy_svc.xp_port);
    943 	iov[0].iov_len = sizeof(dummy_svc.xp_port);
    944 	iov[1].iov_base = (caddr_t)&ybr;
    945 	iov[1].iov_len = sizeof(ybr);
    946 	bytes = readv(fd, iov, 2);
    947 	(void)close(fd);
    948 	if (bytes != (iov[0].iov_len + iov[1].iov_len)) {
    949 		/* Binding file corrupt? */
    950 		yp_log(LOG_WARNING, "%s: %m", path);
    951 		been_ypset = 0;
    952 		return -1;
    953 	}
    954 
    955 	bindsin.sin_addr =
    956 	    ybr.ypbind_respbody.ypbind_bindinfo.ypbind_binding_addr;
    957 
    958 	if (sendto(rpcsock, buf, outlen, 0, (struct sockaddr *)&bindsin,
    959 	    sizeof(bindsin)) < 0) {
    960 		yp_log(LOG_WARNING, "direct_set: sendto: %m");
    961 		return -1;
    962 	}
    963 
    964 	return 0;
    965 }
    966 
    967 static enum clnt_stat
    968 handle_replies(void)
    969 {
    970 	char buf[BUFSIZE];
    971 	int fromlen, inlen;
    972 	struct _dom_binding *ypdb;
    973 	struct sockaddr_in raddr;
    974 	struct rpc_msg msg;
    975 	XDR xdr;
    976 
    977 recv_again:
    978 	(void)memset(&xdr, 0, sizeof(xdr));
    979 	(void)memset(&msg, 0, sizeof(msg));
    980 	msg.acpted_rply.ar_verf = _null_auth;
    981 	msg.acpted_rply.ar_results.where = (caddr_t)&rmtcr;
    982 	msg.acpted_rply.ar_results.proc = xdr_rmtcallres;
    983 
    984 try_again:
    985 	fromlen = sizeof(struct sockaddr);
    986 	inlen = recvfrom(rpcsock, buf, sizeof buf, 0,
    987 		(struct sockaddr *)&raddr, &fromlen);
    988 	if (inlen < 0) {
    989 		if (errno == EINTR)
    990 			goto try_again;
    991 		return RPC_CANTRECV;
    992 	}
    993 	if (inlen < sizeof(u_int32_t))
    994 		goto recv_again;
    995 
    996 	/*
    997 	 * see if reply transaction id matches sent id.
    998 	 * If so, decode the results.
    999 	 */
   1000 	xdrmem_create(&xdr, buf, (u_int)inlen, XDR_DECODE);
   1001 	if (xdr_replymsg(&xdr, &msg)) {
   1002 		if ((msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
   1003 		    (msg.acpted_rply.ar_stat == SUCCESS)) {
   1004 			raddr.sin_port = htons((u_short)rmtcr_port);
   1005 			ypdb = xid2ypdb(msg.rm_xid);
   1006 			if (ypdb != NULL)
   1007 				rpc_received(ypdb->dom_domain, &raddr, 0);
   1008 		}
   1009 	}
   1010 	xdr.x_op = XDR_FREE;
   1011 	msg.acpted_rply.ar_results.proc = xdr_void;
   1012 	xdr_destroy(&xdr);
   1013 
   1014 	return RPC_SUCCESS;
   1015 }
   1016 
   1017 static enum clnt_stat
   1018 handle_ping(void)
   1019 {
   1020 	char buf[BUFSIZE];
   1021 	int fromlen, inlen;
   1022 	struct _dom_binding *ypdb;
   1023 	struct sockaddr_in raddr;
   1024 	struct rpc_msg msg;
   1025 	XDR xdr;
   1026 	bool_t res;
   1027 
   1028 recv_again:
   1029 	(void)memset(&xdr, 0, sizeof(xdr));
   1030 	(void)memset(&msg, 0, sizeof(msg));
   1031 	msg.acpted_rply.ar_verf = _null_auth;
   1032 	msg.acpted_rply.ar_results.where = (caddr_t)&res;
   1033 	msg.acpted_rply.ar_results.proc = xdr_bool;
   1034 
   1035 try_again:
   1036 	fromlen = sizeof (struct sockaddr);
   1037 	inlen = recvfrom(pingsock, buf, sizeof buf, 0,
   1038 		(struct sockaddr *)&raddr, &fromlen);
   1039 	if (inlen < 0) {
   1040 		if (errno == EINTR)
   1041 			goto try_again;
   1042 		return RPC_CANTRECV;
   1043 	}
   1044 	if (inlen < sizeof(u_int32_t))
   1045 		goto recv_again;
   1046 
   1047 	/*
   1048 	 * see if reply transaction id matches sent id.
   1049 	 * If so, decode the results.
   1050 	 */
   1051 	xdrmem_create(&xdr, buf, (u_int)inlen, XDR_DECODE);
   1052 	if (xdr_replymsg(&xdr, &msg)) {
   1053 		if ((msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
   1054 		    (msg.acpted_rply.ar_stat == SUCCESS)) {
   1055 			ypdb = xid2ypdb(msg.rm_xid);
   1056 			if (ypdb != NULL)
   1057 				rpc_received(ypdb->dom_domain, &raddr, 0);
   1058 		}
   1059 	}
   1060 	xdr.x_op = XDR_FREE;
   1061 	msg.acpted_rply.ar_results.proc = xdr_void;
   1062 	xdr_destroy(&xdr);
   1063 
   1064 	return RPC_SUCCESS;
   1065 }
   1066 
   1067 /*
   1068  * LOOPBACK IS MORE IMPORTANT: PUT IN HACK
   1069  */
   1070 void
   1071 rpc_received(char *dom, struct sockaddr_in *raddrp, int force)
   1072 {
   1073 	struct _dom_binding *ypdb;
   1074 	struct iovec iov[2];
   1075 	struct ypbind_resp ybr;
   1076 	int fd;
   1077 
   1078 #ifdef DEBUG
   1079 	if (debug)
   1080 		printf("returned from %s about %s\n",
   1081 		    inet_ntoa(raddrp->sin_addr), dom);
   1082 #endif
   1083 
   1084 	if (dom == NULL)
   1085 		return;
   1086 
   1087 	if (_yp_invalid_domain(dom))
   1088 		return;
   1089 
   1090 		/* don't support insecure servers by default */
   1091 	if (!insecure && ntohs(raddrp->sin_port) >= IPPORT_RESERVED)
   1092 		return;
   1093 
   1094 	for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
   1095 		if (!strcmp(ypdb->dom_domain, dom))
   1096 			break;
   1097 
   1098 	if (ypdb == NULL) {
   1099 		if (force == 0)
   1100 			return;
   1101 		ypdb = makebinding(dom);
   1102 		ypdb->dom_lockfd = -1;
   1103 		ypdb->dom_pnext = ypbindlist;
   1104 		ypbindlist = ypdb;
   1105 	}
   1106 
   1107 	/* soft update, alive */
   1108 	if (ypdb->dom_alive == 1 && force == 0) {
   1109 		if (!memcmp(&ypdb->dom_server_addr, raddrp,
   1110 			    sizeof ypdb->dom_server_addr)) {
   1111 			ypdb->dom_alive = 1;
   1112 			/* recheck binding in 60 sec */
   1113 			ypdb->dom_check_t = time(NULL) + 60;
   1114 		}
   1115 		return;
   1116 	}
   1117 
   1118 	(void)memcpy(&ypdb->dom_server_addr, raddrp,
   1119 	    sizeof ypdb->dom_server_addr);
   1120 	/* recheck binding in 60 seconds */
   1121 	ypdb->dom_check_t = time(NULL) + 60;
   1122 	ypdb->dom_vers = YPVERS;
   1123 	ypdb->dom_alive = 1;
   1124 
   1125 	if (ypdb->dom_lockfd != -1)
   1126 		(void)close(ypdb->dom_lockfd);
   1127 
   1128 	if ((fd = makelock(ypdb)) == -1)
   1129 		return;
   1130 
   1131 	/*
   1132 	 * ok, if BINDINGDIR exists, and we can create the binding file,
   1133 	 * then write to it..
   1134 	 */
   1135 	ypdb->dom_lockfd = fd;
   1136 
   1137 	iov[0].iov_base = (caddr_t)&(udptransp->xp_port);
   1138 	iov[0].iov_len = sizeof udptransp->xp_port;
   1139 	iov[1].iov_base = (caddr_t)&ybr;
   1140 	iov[1].iov_len = sizeof ybr;
   1141 
   1142 	(void)memset(&ybr, 0, sizeof ybr);
   1143 	ybr.ypbind_status = YPBIND_SUCC_VAL;
   1144 	ybr.ypbind_respbody.ypbind_bindinfo.ypbind_binding_addr =
   1145 	    raddrp->sin_addr;
   1146 	ybr.ypbind_respbody.ypbind_bindinfo.ypbind_binding_port =
   1147 	    raddrp->sin_port;
   1148 
   1149 	if (writev(ypdb->dom_lockfd, iov, 2) !=
   1150 	    iov[0].iov_len + iov[1].iov_len) {
   1151 		yp_log(LOG_WARNING, "writev: %m");
   1152 		(void)close(ypdb->dom_lockfd);
   1153 		removelock(ypdb);
   1154 		ypdb->dom_lockfd = -1;
   1155 	}
   1156 }
   1157 
   1158 static struct _dom_binding *
   1159 xid2ypdb(u_int32_t xid)
   1160 {
   1161 	struct _dom_binding *ypdb;
   1162 
   1163 	for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
   1164 		if (ypdb->dom_xid == xid)
   1165 			break;
   1166 	return (ypdb);
   1167 }
   1168 
   1169 static u_int32_t
   1170 unique_xid(struct _dom_binding *ypdb)
   1171 {
   1172 	u_int32_t tmp_xid;
   1173 
   1174 	tmp_xid = (u_int32_t)(((u_long)ypdb) & 0xffffffff);
   1175 	while (xid2ypdb(tmp_xid) != NULL)
   1176 		tmp_xid++;
   1177 
   1178 	return tmp_xid;
   1179 }
   1180