usr.sbin/ypbind/ypbind.c

   1 /*
   2  * Copyright (c) 1992/3 Theo de Raadt <deraadt@fsa.ca>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote
  14  *    products derived from this software without specific prior written
  15  *    permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
  18  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #include <sys/cdefs.h>
  31 __FBSDID("$FreeBSD$");
  32
  33 #include <sys/param.h>
  34 #include <sys/types.h>
  35 #include <sys/wait.h>
  36 #include <sys/ioctl.h>
  37 #include <sys/mman.h>
  38 #include <sys/signal.h>
  39 #include <sys/socket.h>
  40 #include <sys/file.h>
  41 #include <sys/fcntl.h>
  42 #include <sys/stat.h>
  43 #include <sys/uio.h>
  44 #include <ctype.h>
  45 #include <dirent.h>
  46 #include <err.h>
  47 #include <errno.h>
  48 #include <netdb.h>
  49 #include <signal.h>
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53 #include <syslog.h>
  54 #include <unistd.h>
  55 #include <rpc/rpc.h>
  56 #include <rpc/xdr.h>
  57 #include <net/if.h>
  58 #include <netinet/in.h>
  59 #include <arpa/inet.h>
  60 #include <rpc/pmap_clnt.h>
  61 #include <rpc/pmap_prot.h>
  62 #include <rpc/pmap_rmt.h>
  63 #include <rpc/rpc_com.h>
  64 #include <rpcsvc/yp.h>
  65 #include <rpcsvc/ypclnt.h>
  66 #include "yp_ping.h"
  67
  68 #ifndef BINDINGDIR
  69 #define BINDINGDIR "/var/yp/binding"
  70 #endif
  71
  72 #ifndef YPBINDLOCK
  73 #define YPBINDLOCK "/var/run/ypbind.lock"
  74 #endif
  75
  76 struct _dom_binding {
  77         struct _dom_binding *dom_pnext;
  78         char dom_domain[YPMAXDOMAIN + 1];
  79         struct sockaddr_in dom_server_addr;
  80         long int dom_vers;
  81         int dom_lockfd;
  82         int dom_alive;
  83         int dom_broadcast_pid;
  84         int dom_pipe_fds[2];
  85         int dom_default;
  86 };
  87
  88 #define READFD ypdb->dom_pipe_fds[0]
  89 #define WRITEFD ypdb->dom_pipe_fds[1]
  90 #define BROADFD broad_domain->dom_pipe_fds[1]
  91
  92 extern bool_t xdr_domainname(), xdr_ypbind_resp();
  93 extern bool_t xdr_ypreq_key(), xdr_ypresp_val();
  94 extern bool_t xdr_ypbind_setdom();
  95
  96 void    checkwork(void);
  97 void    *ypbindproc_null_2_yp(SVCXPRT *, void *, CLIENT *);
  98 void    *ypbindproc_setdom_2_yp(SVCXPRT *, struct ypbind_setdom *, CLIENT *);
  99 void    rpc_received(char *, struct sockaddr_in *, int);
 100 void    broadcast(struct _dom_binding *);
 101 int     ping(struct _dom_binding *);
 102 int     tell_parent(char *, struct sockaddr_in *);
 103 void    handle_children(struct _dom_binding *);
 104 void    reaper(int);
 105 void    terminate(int);
 106 void    yp_restricted_mode(char *);
 107 int     verify(struct in_addr);
 108
 109 char *domain_name;
 110 struct _dom_binding *ypbindlist;
 111 static struct _dom_binding *broad_domain;
 112
 113 #define YPSET_NO        0
 114 #define YPSET_LOCAL     1
 115 #define YPSET_ALL       2
 116 int ypsetmode = YPSET_NO;
 117 int ypsecuremode = 0;
 118 int ppid;
 119
 120 #define NOT_RESPONDING_HYSTERESIS 10
 121 static int not_responding_count = 0;
 122
 123 /*
 124  * Special restricted mode variables: when in restricted mode, only the
 125  * specified restricted_domain will be bound, and only the servers listed
 126  * in restricted_addrs will be used for binding.
 127  */
 128 #define RESTRICTED_SERVERS 10
 129 int yp_restricted = 0;
 130 int yp_manycast = 0;
 131 struct in_addr restricted_addrs[RESTRICTED_SERVERS];
 132
 133 /* No more than MAX_CHILDREN child broadcasters at a time. */
 134 #ifndef MAX_CHILDREN
 135 #define MAX_CHILDREN 5
 136 #endif
 137 /* No more than MAX_DOMAINS simultaneous domains */
 138 #ifndef MAX_DOMAINS
 139 #define MAX_DOMAINS 200
 140 #endif
 141 /* RPC timeout value */
 142 #ifndef FAIL_THRESHOLD
 143 #define FAIL_THRESHOLD 20
 144 #endif
 145
 146 /* Number of times to fish for a response froma particular set of hosts */
 147 #ifndef MAX_RETRIES
 148 #define MAX_RETRIES 30
 149 #endif
 150
 151 int retries = 0;
 152 int children = 0;
 153 int domains = 0;
 154 int yplockfd;
 155 fd_set fdsr;
 156
 157 SVCXPRT *udptransp, *tcptransp;
 158
 159 void *
 160 ypbindproc_null_2_yp(SVCXPRT *transp, void *argp, CLIENT *clnt)
 161 {
 162         static char res;
 163
 164         bzero(&res, sizeof(res));
 165         return &res;
 166 }
 167
 168 struct ypbind_resp *
 169 ypbindproc_domain_2_yp(SVCXPRT *transp, domainname *argp, CLIENT *clnt)
 170 {
 171         static struct ypbind_resp res;
 172         struct _dom_binding *ypdb;
 173         char path[MAXPATHLEN];
 174
 175         bzero(&res, sizeof res);
 176         res.ypbind_status = YPBIND_FAIL_VAL;
 177         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_NOSERV;
 178
 179         if (strchr(*argp, '/')) {
 180                 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
 181 rejecting.", *argp);
 182                 return(&res);
 183         }
 184
 185         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 186                 if (strcmp(ypdb->dom_domain, *argp) == 0)
 187                         break;
 188                 }
 189
 190         if (ypdb == NULL) {
 191                 if (yp_restricted) {
 192                         syslog(LOG_NOTICE, "Running in restricted mode -- request to bind domain \"%s\" rejected.\n", *argp);
 193                         return (&res);
 194                 }
 195
 196                 if (domains >= MAX_DOMAINS) {
 197                         syslog(LOG_WARNING, "domain limit (%d) exceeded",
 198                                                         MAX_DOMAINS);
 199                         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
 200                         return (&res);
 201                 }
 202                 if (strlen(*argp) > YPMAXDOMAIN) {
 203                         syslog(LOG_WARNING, "domain %s too long", *argp);
 204                         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
 205                         return (&res);
 206                 }
 207                 ypdb = malloc(sizeof *ypdb);
 208                 if (ypdb == NULL) {
 209                         syslog(LOG_WARNING, "malloc: %m");
 210                         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
 211                         return (&res);
 212                 }
 213                 bzero(ypdb, sizeof *ypdb);
 214                 strlcpy(ypdb->dom_domain, *argp, sizeof ypdb->dom_domain);
 215                 ypdb->dom_vers = YPVERS;
 216                 ypdb->dom_alive = 0;
 217                 ypdb->dom_default = 0;
 218                 ypdb->dom_lockfd = -1;
 219                 sprintf(path, "%s/%s.%ld", BINDINGDIR,
 220                                         ypdb->dom_domain, ypdb->dom_vers);
 221                 unlink(path);
 222                 ypdb->dom_pnext = ypbindlist;
 223                 ypbindlist = ypdb;
 224                 domains++;
 225         }
 226
 227         if (ping(ypdb)) {
 228                 return (&res);
 229         }
 230
 231         res.ypbind_status = YPBIND_SUCC_VAL;
 232         res.ypbind_resp_u.ypbind_error = 0; /* Success */
 233         *(u_int32_t *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr =
 234                 ypdb->dom_server_addr.sin_addr.s_addr;
 235         *(u_short *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port =
 236                 ypdb->dom_server_addr.sin_port;
 237         /*printf("domain %s at %s/%d\n", ypdb->dom_domain,
 238                 inet_ntoa(ypdb->dom_server_addr.sin_addr),
 239                 ntohs(ypdb->dom_server_addr.sin_port));*/
 240         return (&res);
 241 }
 242
 243 void *
 244 ypbindproc_setdom_2_yp(SVCXPRT *transp, ypbind_setdom *argp, CLIENT *clnt)
 245 {
 246         struct sockaddr_in *fromsin, bindsin;
 247         static char             *result = NULL;
 248
 249         if (strchr(argp->ypsetdom_domain, '/')) {
 250                 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
 251 rejecting.", argp->ypsetdom_domain);
 252                 return(NULL);
 253         }
 254         fromsin = svc_getcaller(transp);
 255
 256         switch (ypsetmode) {
 257         case YPSET_LOCAL:
 258                 if (fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) {
 259                         svcerr_noprog(transp);
 260                         return(NULL);
 261                 }
 262                 break;
 263         case YPSET_ALL:
 264                 break;
 265         case YPSET_NO:
 266         default:
 267                 svcerr_noprog(transp);
 268                 return(NULL);
 269         }
 270
 271         if (ntohs(fromsin->sin_port) >= IPPORT_RESERVED) {
 272                 svcerr_noprog(transp);
 273                 return(NULL);
 274         }
 275
 276         if (argp->ypsetdom_vers != YPVERS) {
 277                 svcerr_noprog(transp);
 278                 return(NULL);
 279         }
 280
 281         bzero(&bindsin, sizeof bindsin);
 282         bindsin.sin_family = AF_INET;
 283         bindsin.sin_addr.s_addr = *(u_int32_t *)argp->ypsetdom_binding.ypbind_binding_addr;
 284         bindsin.sin_port = *(u_short *)argp->ypsetdom_binding.ypbind_binding_port;
 285         rpc_received(argp->ypsetdom_domain, &bindsin, 1);
 286
 287         return((void *) &result);
 288 }
 289
 290 void
 291 ypbindprog_2(struct svc_req *rqstp, register SVCXPRT *transp)
 292 {
 293         union {
 294                 domainname ypbindproc_domain_2_arg;
 295                 struct ypbind_setdom ypbindproc_setdom_2_arg;
 296         } argument;
 297         struct authunix_parms *creds;
 298         char *result;
 299         bool_t (*xdr_argument)(), (*xdr_result)();
 300         char *(*local)();
 301
 302         switch (rqstp->rq_proc) {
 303         case YPBINDPROC_NULL:
 304                 xdr_argument = xdr_void;
 305                 xdr_result = xdr_void;
 306                 local = (char *(*)()) ypbindproc_null_2_yp;
 307                 break;
 308
 309         case YPBINDPROC_DOMAIN:
 310                 xdr_argument = xdr_domainname;
 311                 xdr_result = xdr_ypbind_resp;
 312                 local = (char *(*)()) ypbindproc_domain_2_yp;
 313                 break;
 314
 315         case YPBINDPROC_SETDOM:
 316                 switch (rqstp->rq_cred.oa_flavor) {
 317                 case AUTH_UNIX:
 318                         creds = (struct authunix_parms *)rqstp->rq_clntcred;
 319                         if (creds->aup_uid != 0) {
 320                                 svcerr_auth(transp, AUTH_BADCRED);
 321                                 return;
 322                         }
 323                         break;
 324                 default:
 325                         svcerr_auth(transp, AUTH_TOOWEAK);
 326                         return;
 327                 }
 328
 329                 xdr_argument = xdr_ypbind_setdom;
 330                 xdr_result = xdr_void;
 331                 local = (char *(*)()) ypbindproc_setdom_2_yp;
 332                 break;
 333
 334         default:
 335                 svcerr_noproc(transp);
 336                 return;
 337         }
 338         bzero(&argument, sizeof(argument));
 339         if (!svc_getargs(transp, (xdrproc_t)xdr_argument, &argument)) {
 340                 svcerr_decode(transp);
 341                 return;
 342         }
 343         result = (*local)(transp, &argument, rqstp);
 344         if (result != NULL &&
 345             !svc_sendreply(transp, (xdrproc_t)xdr_result, result)) {
 346                 svcerr_systemerr(transp);
 347         }
 348         return;
 349 }
 350
 351 /* Jack the reaper */
 352 void
 353 reaper(int sig)
 354 {
 355         int st;
 356
 357         while (wait3(&st, WNOHANG, NULL) > 0)
 358                 children--;
 359 }
 360
 361 void
 362 terminate(int sig)
 363 {
 364         struct _dom_binding *ypdb;
 365         char path[MAXPATHLEN];
 366
 367         if (ppid != getpid())
 368                 exit(0);
 369
 370         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 371                 close(ypdb->dom_lockfd);
 372                 if (ypdb->dom_broadcast_pid)
 373                         kill(ypdb->dom_broadcast_pid, SIGINT);
 374                 sprintf(path, "%s/%s.%ld", BINDINGDIR,
 375                         ypdb->dom_domain, ypdb->dom_vers);
 376                 unlink(path);
 377         }
 378         close(yplockfd);
 379         unlink(YPBINDLOCK);
 380         pmap_unset(YPBINDPROG, YPBINDVERS);
 381         exit(0);
 382 }
 383
 384 int
 385 main(int argc, char *argv[])
 386 {
 387         struct timeval tv;
 388         int i;
 389         DIR *dird;
 390         struct dirent *dirp;
 391         struct _dom_binding *ypdb, *next;
 392
 393         /* Check that another ypbind isn't already running. */
 394         if ((yplockfd = (open(YPBINDLOCK, O_RDONLY|O_CREAT, 0444))) == -1)
 395                 err(1, "%s", YPBINDLOCK);
 396
 397         if (flock(yplockfd, LOCK_EX|LOCK_NB) == -1 && errno == EWOULDBLOCK)
 398                 errx(1, "another ypbind is already running. Aborting");
 399
 400         /* XXX domainname will be overridden if we use restricted mode */
 401         yp_get_default_domain(&domain_name);
 402         if (domain_name[0] == '\0')
 403                 errx(1, "domainname not set. Aborting");
 404
 405         for (i = 1; i<argc; i++) {
 406                 if (strcmp("-ypset", argv[i]) == 0)
 407                         ypsetmode = YPSET_ALL;
 408                 else if (strcmp("-ypsetme", argv[i]) == 0)
 409                         ypsetmode = YPSET_LOCAL;
 410                 else if (strcmp("-s", argv[i]) == 0)
 411                         ypsecuremode++;
 412                 else if (strcmp("-S", argv[i]) == 0 && argc > i)
 413                         yp_restricted_mode(argv[++i]);
 414                 else if (strcmp("-m", argv[i]) == 0)
 415                         yp_manycast++;
 416                 else
 417                         errx(1, "unknown option: %s", argv[i]);
 418         }
 419
 420         if (strlen(domain_name) > YPMAXDOMAIN)
 421                 warnx("truncating domain name %s", domain_name);
 422
 423         /* blow away everything in BINDINGDIR (if it exists) */
 424
 425         if ((dird = opendir(BINDINGDIR)) != NULL) {
 426                 char path[MAXPATHLEN];
 427                 while ((dirp = readdir(dird)) != NULL)
 428                         if (strcmp(dirp->d_name, ".") &&
 429                             strcmp(dirp->d_name, "..")) {
 430                                 sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name);
 431                                 unlink(path);
 432                         }
 433                 closedir(dird);
 434         }
 435
 436 #ifdef DAEMON
 437         if (daemon(0,0))
 438                 err(1, "fork");
 439 #endif
 440
 441         pmap_unset(YPBINDPROG, YPBINDVERS);
 442
 443         udptransp = svcudp_create(RPC_ANYSOCK);
 444         if (udptransp == NULL)
 445                 errx(1, "cannot create udp service");
 446         if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 447             IPPROTO_UDP))
 448                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)");
 449
 450         tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0);
 451         if (tcptransp == NULL)
 452                 errx(1, "cannot create tcp service");
 453
 454         if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 455             IPPROTO_TCP))
 456                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)");
 457
 458         /* build initial domain binding, make it "unsuccessful" */
 459         ypbindlist = malloc(sizeof *ypbindlist);
 460         if (ypbindlist == NULL)
 461                 errx(1, "malloc");
 462         bzero(ypbindlist, sizeof *ypbindlist);
 463         strlcpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain);
 464         ypbindlist->dom_vers = YPVERS;
 465         ypbindlist->dom_alive = 0;
 466         ypbindlist->dom_lockfd = -1;
 467         ypbindlist->dom_default = 1;
 468         domains++;
 469
 470         signal(SIGCHLD, reaper);
 471         signal(SIGTERM, terminate);
 472
 473         ppid = getpid(); /* Remember who we are. */
 474
 475         openlog(argv[0], LOG_PID, LOG_DAEMON);
 476
 477         if (madvise(NULL, 0, MADV_PROTECT) != 0)
 478                 syslog(LOG_WARNING, "madvise(): %m");
 479
 480         /* Kick off the default domain */
 481         broadcast(ypbindlist);
 482
 483         while (1) {
 484                 fdsr = svc_fdset;
 485
 486                 tv.tv_sec = 60;
 487                 tv.tv_usec = 0;
 488
 489                 switch (select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) {
 490                 case 0:
 491                         checkwork();
 492                         break;
 493                 case -1:
 494                         if (errno != EINTR)
 495                                 syslog(LOG_WARNING, "select: %m");
 496                         break;
 497                 default:
 498                         for (ypdb = ypbindlist; ypdb; ypdb = next) {
 499                                 next = ypdb->dom_pnext;
 500                                 if (READFD > 0 && FD_ISSET(READFD, &fdsr)) {
 501                                         handle_children(ypdb);
 502                                         if (children == (MAX_CHILDREN - 1))
 503                                                 checkwork();
 504                                 }
 505                         }
 506                         svc_getreqset(&fdsr);
 507                         break;
 508                 }
 509         }
 510
 511         /* NOTREACHED */
 512         exit(1);
 513 }
 514
 515 void
 516 checkwork(void)
 517 {
 518         struct _dom_binding *ypdb;
 519
 520         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
 521                 ping(ypdb);
 522 }
 523
 524 /* The clnt_broadcast() callback mechanism sucks. */
 525
 526 /*
 527  * Receive results from broadcaster. Don't worry about passing
 528  * bogus info to rpc_received() -- it can handle it. Note that we
 529  * must be sure to invalidate the dom_pipe_fds descriptors here:
 530  * since descriptors can be re-used, we have to make sure we
 531  * don't mistake one of the RPC descriptors for one of the pipes.
 532  * What's weird is that forgetting to invalidate the pipe descriptors
 533  * doesn't always result in an error (otherwise I would have caught
 534  * the mistake much sooner), even though logically it should.
 535  */
 536 void
 537 handle_children(struct _dom_binding *ypdb)
 538 {
 539         char buf[YPMAXDOMAIN + 1];
 540         struct sockaddr_in addr;
 541         int d = 0, a = 0;
 542         struct _dom_binding *y, *prev = NULL;
 543         char path[MAXPATHLEN];
 544
 545         if ((d = read(READFD, &buf, sizeof(buf))) <= 0)
 546                 syslog(LOG_WARNING, "could not read from child: %m");
 547
 548         if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0)
 549                 syslog(LOG_WARNING, "could not read from child: %m");
 550
 551         close(READFD);
 552         FD_CLR(READFD, &fdsr);
 553         FD_CLR(READFD, &svc_fdset);
 554         READFD = WRITEFD = -1;
 555         if (d > 0 && a > 0)
 556                 rpc_received(buf, &addr, 0);
 557         else {
 558                 for (y = ypbindlist; y; y = y->dom_pnext) {
 559                         if (y == ypdb)
 560                                 break;
 561                         prev = y;
 562                 }
 563                 switch (ypdb->dom_default) {
 564                 case 0:
 565                         if (prev == NULL)
 566                                 ypbindlist = y->dom_pnext;
 567                         else
 568                                 prev->dom_pnext = y->dom_pnext;
 569                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 570                                 ypdb->dom_domain, YPVERS);
 571                         close(ypdb->dom_lockfd);
 572                         unlink(path);
 573                         free(ypdb);
 574                         domains--;
 575                         return;
 576                 case 1:
 577                         ypdb->dom_broadcast_pid = 0;
 578                         ypdb->dom_alive = 0;
 579                         broadcast(ypdb);
 580                         return;
 581                 default:
 582                         break;
 583                 }
 584         }
 585
 586         return;
 587 }
 588
 589 /*
 590  * Send our dying words back to our parent before we perish.
 591  */
 592 int
 593 tell_parent(char *dom, struct sockaddr_in *addr)
 594 {
 595         char buf[YPMAXDOMAIN + 1];
 596         struct timeval timeout;
 597         fd_set fds;
 598
 599         timeout.tv_sec = 5;
 600         timeout.tv_usec = 0;
 601
 602         sprintf(buf, "%s", broad_domain->dom_domain);
 603         if (write(BROADFD, &buf, sizeof(buf)) < 0)
 604                 return(1);
 605
 606         /*
 607          * Stay in sync with parent: wait for it to read our first
 608          * message before sending the second.
 609          */
 610
 611         FD_ZERO(&fds);
 612         FD_SET(BROADFD, &fds);
 613         if (select(FD_SETSIZE, NULL, &fds, NULL, &timeout) == -1)
 614                 return(1);
 615         if (FD_ISSET(BROADFD, &fds)) {
 616                 if (write(BROADFD, addr, sizeof(struct sockaddr_in)) < 0)
 617                         return(1);
 618         } else {
 619                 return(1);
 620         }
 621
 622         close(BROADFD);
 623         return (0);
 624 }
 625
 626 bool_t broadcast_result(out, addr)
 627 bool_t *out;
 628 struct sockaddr_in *addr;
 629 {
 630         if (retries >= MAX_RETRIES) {
 631                 bzero(addr, sizeof(struct sockaddr_in));
 632                 if (tell_parent(broad_domain->dom_domain, addr))
 633                         syslog(LOG_WARNING, "lost connection to parent");
 634                 return (TRUE);
 635         }
 636
 637         if (yp_restricted && verify(addr->sin_addr)) {
 638                 retries++;
 639                 syslog(LOG_NOTICE, "NIS server at %s not in restricted mode access list -- rejecting.\n",inet_ntoa(addr->sin_addr));
 640                 return (FALSE);
 641         } else {
 642                 if (tell_parent(broad_domain->dom_domain, addr))
 643                         syslog(LOG_WARNING, "lost connection to parent");
 644                 return (TRUE);
 645         }
 646 }
 647
 648 /*
 649  * The right way to send RPC broadcasts.
 650  * Use the clnt_broadcast() RPC service. Unfortunately, clnt_broadcast()
 651  * blocks while waiting for replies, so we have to fork off separate
 652  * broadcaster processes that do the waiting and then transmit their
 653  * results back to the parent for processing. We also have to remember
 654  * to save the name of the domain we're trying to bind in a global
 655  * variable since clnt_broadcast() provides no way to pass things to
 656  * the 'eachresult' callback function.
 657  */
 658 void
 659 broadcast(struct _dom_binding *ypdb)
 660 {
 661         bool_t out = FALSE;
 662         enum clnt_stat stat;
 663
 664         if (children >= MAX_CHILDREN || ypdb->dom_broadcast_pid)
 665                 return;
 666
 667         if (pipe(ypdb->dom_pipe_fds) < 0) {
 668                 syslog(LOG_WARNING, "pipe: %m");
 669                 return;
 670         }
 671
 672         if (ypdb->dom_vers == -1 && (long)ypdb->dom_server_addr.sin_addr.s_addr) {
 673                 if (not_responding_count++ >= NOT_RESPONDING_HYSTERESIS) {
 674                         not_responding_count = NOT_RESPONDING_HYSTERESIS;
 675                         syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding",
 676                             inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain);
 677                 }
 678         }
 679
 680         broad_domain = ypdb;
 681         flock(ypdb->dom_lockfd, LOCK_UN);
 682
 683         switch ((ypdb->dom_broadcast_pid = fork())) {
 684         case 0:
 685                 close(READFD);
 686                 signal(SIGCHLD, SIG_DFL);
 687                 signal(SIGTERM, SIG_DFL);
 688                 break;
 689         case -1:
 690                 syslog(LOG_WARNING, "fork: %m");
 691                 close(READFD);
 692                 close(WRITEFD);
 693                 return;
 694         default:
 695                 close(WRITEFD);
 696                 FD_SET(READFD, &svc_fdset);
 697                 children++;
 698                 return;
 699         }
 700
 701         /* Release all locks before doing anything else. */
 702         while (ypbindlist) {
 703                 close(ypbindlist->dom_lockfd);
 704                 ypbindlist = ypbindlist->dom_pnext;
 705         }
 706         close(yplockfd);
 707
 708         /*
 709          * Special 'many-cast' behavior. If we're in restricted mode,
 710          * we have a list of possible server addresses to try. What
 711          * we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK
 712          * procedure and time the replies. Whoever replies fastest
 713          * gets to be our server. Note that this is not a broadcast
 714          * operation: we transmit uni-cast datagrams only.
 715          */
 716         if (yp_restricted && yp_manycast) {
 717                 short                   port;
 718                 int                     i;
 719                 struct sockaddr_in      sin;
 720
 721                 i = __yp_ping(restricted_addrs, yp_restricted,
 722                                 ypdb->dom_domain, &port);
 723                 if (i == -1) {
 724                         bzero(&ypdb->dom_server_addr,
 725                             sizeof(struct sockaddr_in));
 726                         if (tell_parent(ypdb->dom_domain,
 727                                 &ypdb->dom_server_addr))
 728                         syslog(LOG_WARNING, "lost connection to parent");
 729                 } else {
 730                         bzero(&sin, sizeof(struct sockaddr_in));
 731                         bcopy(&restricted_addrs[i],
 732                             &sin.sin_addr, sizeof(struct in_addr));
 733                         sin.sin_family = AF_INET;
 734                         sin.sin_port = port;
 735                         if (tell_parent(broad_domain->dom_domain, &sin))
 736                                 syslog(LOG_WARNING,
 737                                         "lost connection to parent");
 738                 }
 739                 _exit(0);
 740         }
 741
 742         retries = 0;
 743
 744         {
 745                 char *ptr;
 746
 747                 ptr = ypdb->dom_domain;
 748                 stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK,
 749                         (xdrproc_t)xdr_domainname, &ptr,
 750                         (xdrproc_t)xdr_bool, &out,
 751                         (resultproc_t)broadcast_result);
 752         }
 753
 754         if (stat != RPC_SUCCESS) {
 755                 bzero(&ypdb->dom_server_addr,
 756                     sizeof(struct sockaddr_in));
 757                 if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr))
 758                         syslog(LOG_WARNING, "lost connection to parent");
 759         }
 760
 761         _exit(0);
 762 }
 763
 764 /*
 765  * The right way to check if a server is alive.
 766  * Attempt to get a client handle pointing to the server and send a
 767  * YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE,
 768  * we invalidate this binding entry and send out a broadcast to try to
 769  * establish a new binding. Note that we treat non-default domains
 770  * specially: once bound, we keep tabs on our server, but if it
 771  * goes away and fails to respond after one round of broadcasting, we
 772  * abandon it until a client specifically references it again. We make
 773  * every effort to keep our default domain bound, however, since we
 774  * need it to keep the system on its feet.
 775  */
 776 int
 777 ping(struct _dom_binding *ypdb)
 778 {
 779         bool_t out;
 780         struct timeval interval, timeout;
 781         enum clnt_stat stat;
 782         int rpcsock = RPC_ANYSOCK;
 783         CLIENT *client_handle;
 784
 785         interval.tv_sec = FAIL_THRESHOLD;
 786         interval.tv_usec = 0;
 787         timeout.tv_sec = FAIL_THRESHOLD;
 788         timeout.tv_usec = 0;
 789
 790         if (ypdb->dom_broadcast_pid)
 791                 return(1);
 792
 793         if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr,
 794                 YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE,
 795                 RPCSMALLMSGSIZE)) == (CLIENT *)NULL) {
 796                 /* Can't get a handle: we're dead. */
 797                 ypdb->dom_alive = 0;
 798                 ypdb->dom_vers = -1;
 799                 broadcast(ypdb);
 800                 return(1);
 801         }
 802
 803         {
 804                 char *ptr;
 805
 806                 ptr = ypdb->dom_domain;
 807
 808                 stat = clnt_call(client_handle, YPPROC_DOMAIN,
 809                     (xdrproc_t)xdr_domainname, &ptr,
 810                     (xdrproc_t)xdr_bool, &out, timeout);
 811                 if (stat != RPC_SUCCESS || out == FALSE) {
 812                         ypdb->dom_alive = 0;
 813                         ypdb->dom_vers = -1;
 814                         clnt_destroy(client_handle);
 815                         broadcast(ypdb);
 816                         return(1);
 817                 }
 818         }
 819
 820         clnt_destroy(client_handle);
 821         return(0);
 822 }
 823
 824 void
 825 rpc_received(char *dom, struct sockaddr_in *raddrp, int force)
 826 {
 827         struct _dom_binding *ypdb, *prev = NULL;
 828         struct iovec iov[2];
 829         struct ypbind_resp ybr;
 830         char path[MAXPATHLEN];
 831         int fd;
 832
 833         /*printf("returned from %s/%d about %s\n", inet_ntoa(raddrp->sin_addr),
 834                ntohs(raddrp->sin_port), dom);*/
 835
 836         if (dom == NULL)
 837                 return;
 838
 839         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 840                 if (strcmp(ypdb->dom_domain, dom) == 0)
 841                         break;
 842                 prev = ypdb;
 843         }
 844
 845         if (ypdb && force) {
 846                 if (ypdb->dom_broadcast_pid) {
 847                         kill(ypdb->dom_broadcast_pid, SIGINT);
 848                         close(READFD);
 849                         FD_CLR(READFD, &fdsr);
 850                         FD_CLR(READFD, &svc_fdset);
 851                         READFD = WRITEFD = -1;
 852                 }
 853         }
 854
 855         /* if in secure mode, check originating port number */
 856         if ((ypsecuremode && (ntohs(raddrp->sin_port) >= IPPORT_RESERVED))) {
 857             syslog(LOG_WARNING, "Rejected NIS server on [%s/%d] for domain %s.",
 858                    inet_ntoa(raddrp->sin_addr), ntohs(raddrp->sin_port),
 859                    dom);
 860             if (ypdb != NULL) {
 861                 ypdb->dom_broadcast_pid = 0;
 862                 ypdb->dom_alive = 0;
 863             }
 864             return;
 865         }
 866
 867         if (raddrp->sin_addr.s_addr == (long)0) {
 868                 switch (ypdb->dom_default) {
 869                 case 0:
 870                         if (prev == NULL)
 871                                 ypbindlist = ypdb->dom_pnext;
 872                         else
 873                                 prev->dom_pnext = ypdb->dom_pnext;
 874                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 875                                 ypdb->dom_domain, YPVERS);
 876                         close(ypdb->dom_lockfd);
 877                         unlink(path);
 878                         free(ypdb);
 879                         domains--;
 880                         return;
 881                 case 1:
 882                         ypdb->dom_broadcast_pid = 0;
 883                         ypdb->dom_alive = 0;
 884                         broadcast(ypdb);
 885                         return;
 886                 default:
 887                         break;
 888                 }
 889         }
 890
 891         if (ypdb == NULL) {
 892                 if (force == 0)
 893                         return;
 894                 if (strlen(dom) > YPMAXDOMAIN) {
 895                         syslog(LOG_WARNING, "domain %s too long", dom);
 896                         return;
 897                 }
 898                 ypdb = malloc(sizeof *ypdb);
 899                 if (ypdb == NULL) {
 900                         syslog(LOG_WARNING, "malloc: %m");
 901                         return;
 902                 }
 903                 bzero(ypdb, sizeof *ypdb);
 904                 strlcpy(ypdb->dom_domain, dom, sizeof ypdb->dom_domain);
 905                 ypdb->dom_lockfd = -1;
 906                 ypdb->dom_default = 0;
 907                 ypdb->dom_pnext = ypbindlist;
 908                 ypbindlist = ypdb;
 909         }
 910
 911         /* We've recovered from a crash: inform the world. */
 912         if (ypdb->dom_vers == -1 && ypdb->dom_server_addr.sin_addr.s_addr) {
 913                 if (not_responding_count >= NOT_RESPONDING_HYSTERESIS) {
 914                         not_responding_count = 0;
 915                         syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" OK",
 916                             inet_ntoa(raddrp->sin_addr), ypdb->dom_domain);
 917                 }
 918         }
 919
 920         bcopy(raddrp, &ypdb->dom_server_addr,
 921                 sizeof ypdb->dom_server_addr);
 922
 923         ypdb->dom_vers = YPVERS;
 924         ypdb->dom_alive = 1;
 925         ypdb->dom_broadcast_pid = 0;
 926
 927         if (ypdb->dom_lockfd != -1)
 928                 close(ypdb->dom_lockfd);
 929
 930         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 931                 ypdb->dom_domain, ypdb->dom_vers);
 932 #ifdef O_SHLOCK
 933         if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) {
 934                 (void)mkdir(BINDINGDIR, 0755);
 935                 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1)
 936                         return;
 937         }
 938 #else
 939         if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) {
 940                 (void)mkdir(BINDINGDIR, 0755);
 941                 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1)
 942                         return;
 943         }
 944         flock(fd, LOCK_SH);
 945 #endif
 946
 947         /*
 948          * ok, if BINDINGDIR exists, and we can create the binding file,
 949          * then write to it..
 950          */
 951         ypdb->dom_lockfd = fd;
 952
 953         iov[0].iov_base = (char *)&(udptransp->xp_port);
 954         iov[0].iov_len = sizeof udptransp->xp_port;
 955         iov[1].iov_base = (char *)&ybr;
 956         iov[1].iov_len = sizeof ybr;
 957
 958         bzero(&ybr, sizeof ybr);
 959         ybr.ypbind_status = YPBIND_SUCC_VAL;
 960         *(u_int32_t *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = raddrp->sin_addr.s_addr;
 961         *(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = raddrp->sin_port;
 962
 963         if (writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) {
 964                 syslog(LOG_WARNING, "write: %m");
 965                 close(ypdb->dom_lockfd);
 966                 ypdb->dom_lockfd = -1;
 967                 return;
 968         }
 969 }
 970
 971 /*
 972  * Check address against list of allowed servers. Return 0 if okay,
 973  * 1 if not matched.
 974  */
 975 int
 976 verify(struct in_addr addr)
 977 {
 978         int i;
 979
 980         for (i = 0; i < RESTRICTED_SERVERS; i++)
 981                 if (!bcmp(&addr, &restricted_addrs[i], sizeof(struct in_addr)))
 982                         return(0);
 983
 984         return(1);
 985 }
 986
 987 /*
 988  * Try to set restricted mode. We default to normal mode if we can't
 989  * resolve the specified hostnames.
 990  */
 991 void
 992 yp_restricted_mode(char *args)
 993 {
 994         struct hostent *h;
 995         int i = 0;
 996         char *s;
 997
 998         /* Find the restricted domain. */
 999         if ((s = strsep(&args, ",")) == NULL)
1000                 return;
1001         domain_name = s;
1002
1003         /* Get the addresses of the servers. */
1004         while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) {
1005                 if ((h = gethostbyname(s)) == NULL)
1006                         return;
1007                 bcopy (h->h_addr_list[0], &restricted_addrs[i],
1008                     sizeof(struct in_addr));
1009                 i++;
1010         }
1011
1012         /* ypset and ypsetme not allowed with restricted mode */
1013         ypsetmode = YPSET_NO;
1014
1015         yp_restricted = i;
1016         return;
1017 }