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 #ifndef lint
  31 static const char rcsid[] =
  32   "$FreeBSD: src/usr.sbin/ypbind/ypbind.c,v 1.30.2.2 2002/02/15 00:46:59 des Exp $";
  33 #endif /* not lint */
  34
  35 #include <sys/param.h>
  36 #include <sys/types.h>
  37 #include <sys/wait.h>
  38 #include <sys/ioctl.h>
  39 #include <sys/signal.h>
  40 #include <sys/socket.h>
  41 #include <sys/file.h>
  42 #include <sys/fcntl.h>
  43 #include <sys/stat.h>
  44 #include <sys/uio.h>
  45 #include <ctype.h>
  46 #include <dirent.h>
  47 #include <err.h>
  48 #include <errno.h>
  49 #include <netdb.h>
  50 #include <signal.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <syslog.h>
  55 #include <unistd.h>
  56 #include <rpc/rpc.h>
  57 #include <rpc/xdr.h>
  58 #include <net/if.h>
  59 #include <netinet/in.h>
  60 #include <arpa/inet.h>
  61 #include <rpc/pmap_clnt.h>
  62 #include <rpc/pmap_prot.h>
  63 #include <rpc/pmap_rmt.h>
  64 #include <rpc/rpc_com.h>
  65 #include <rpcsvc/yp.h>
  66 struct dom_binding{};
  67 #include <rpcsvc/ypclnt.h>
  68 #include "yp_ping.h"
  69
  70 #ifndef BINDINGDIR
  71 #define BINDINGDIR "/var/yp/binding"
  72 #endif
  73
  74 #ifndef YPBINDLOCK
  75 #define YPBINDLOCK "/var/run/ypbind.lock"
  76 #endif
  77
  78 struct _dom_binding {
  79         struct _dom_binding *dom_pnext;
  80         char dom_domain[YPMAXDOMAIN + 1];
  81         struct sockaddr_in dom_server_addr;
  82         long int dom_vers;
  83         int dom_lockfd;
  84         int dom_alive;
  85         int dom_broadcast_pid;
  86         int dom_pipe_fds[2];
  87         int dom_default;
  88 };
  89
  90 #define READFD ypdb->dom_pipe_fds[0]
  91 #define WRITEFD ypdb->dom_pipe_fds[1]
  92 #define BROADFD broad_domain->dom_pipe_fds[1]
  93
  94 extern bool_t xdr_domainname(), xdr_ypbind_resp();
  95 extern bool_t xdr_ypreq_key(), xdr_ypresp_val();
  96 extern bool_t xdr_ypbind_setdom();
  97
  98 void    checkwork(void);
  99 void    *ypbindproc_null_2_yp(SVCXPRT *, void *, CLIENT *);
 100 void    *ypbindproc_setdom_2_yp(SVCXPRT *, struct ypbind_setdom *, CLIENT *);
 101 void    rpc_received(char *, struct sockaddr_in *, int);
 102 void    broadcast(struct _dom_binding *);
 103 int     ping(struct _dom_binding *);
 104 int     tell_parent(char *, struct sockaddr_in *);
 105 void    handle_children(struct _dom_binding *);
 106 void    reaper(int);
 107 void    terminate(int);
 108 void    yp_restricted_mode(char *);
 109 int     verify(struct in_addr);
 110
 111 char *domain_name;
 112 struct _dom_binding *ypbindlist;
 113 static struct _dom_binding *broad_domain;
 114
 115 #define YPSET_NO        0
 116 #define YPSET_LOCAL     1
 117 #define YPSET_ALL       2
 118 int ypsetmode = YPSET_NO;
 119 int ypsecuremode = 0;
 120 int ppid;
 121
 122 /*
 123  * Special restricted mode variables: when in restricted mode, only the
 124  * specified restricted_domain will be bound, and only the servers listed
 125  * in restricted_addrs will be used for binding.
 126  */
 127 #define RESTRICTED_SERVERS 10
 128 int yp_restricted = 0;
 129 int yp_manycast = 0;
 130 struct in_addr restricted_addrs[RESTRICTED_SERVERS];
 131
 132 /* No more than MAX_CHILDREN child broadcasters at a time. */
 133 #ifndef MAX_CHILDREN
 134 #define MAX_CHILDREN 5
 135 #endif
 136 /* No more than MAX_DOMAINS simultaneous domains */
 137 #ifndef MAX_DOMAINS
 138 #define MAX_DOMAINS 200
 139 #endif
 140 /* RPC timeout value */
 141 #ifndef FAIL_THRESHOLD
 142 #define FAIL_THRESHOLD 20
 143 #endif
 144
 145 /* Number of times to fish for a response froma particular set of hosts */
 146 #ifndef MAX_RETRIES
 147 #define MAX_RETRIES 30
 148 #endif
 149
 150 int retries = 0;
 151 int children = 0;
 152 int domains = 0;
 153 int yplockfd;
 154 fd_set fdsr;
 155
 156 SVCXPRT *udptransp, *tcptransp;
 157
 158 void *
 159 ypbindproc_null_2_yp(transp, argp, clnt)
 160 SVCXPRT *transp;
 161 void *argp;
 162 CLIENT *clnt;
 163 {
 164         static char res;
 165
 166         bzero((char *)&res, sizeof(res));
 167         return (void *)&res;
 168 }
 169
 170 struct ypbind_resp *
 171 ypbindproc_domain_2_yp(transp, argp, clnt)
 172 SVCXPRT *transp;
 173 domainname *argp;
 174 CLIENT *clnt;
 175 {
 176         static struct ypbind_resp res;
 177         struct _dom_binding *ypdb;
 178         char path[MAXPATHLEN];
 179
 180         bzero((char *)&res, sizeof res);
 181         res.ypbind_status = YPBIND_FAIL_VAL;
 182         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_NOSERV;
 183
 184         if (strchr(*argp, '/')) {
 185                 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
 186 rejecting.", *argp);
 187                 return(&res);
 188         }
 189
 190         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 191                 if (strcmp(ypdb->dom_domain, *argp) == 0)
 192                         break;
 193                 }
 194
 195         if (ypdb == NULL) {
 196                 if (yp_restricted) {
 197                         syslog(LOG_NOTICE, "Running in restricted mode -- request to bind domain \"%s\" rejected.\n", *argp);
 198                         return (&res);
 199                 }
 200
 201                 if (domains >= MAX_DOMAINS) {
 202                         syslog(LOG_WARNING, "domain limit (%d) exceeded",
 203                                                         MAX_DOMAINS);
 204                         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
 205                         return (&res);
 206                 }
 207                 ypdb = (struct _dom_binding *)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((char *)ypdb, sizeof *ypdb);
 214                 strncpy(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(transp, argp, clnt)
 245 SVCXPRT *transp;
 246 ypbind_setdom *argp;
 247 CLIENT *clnt;
 248 {
 249         struct sockaddr_in *fromsin, bindsin;
 250         static char             *result = NULL;
 251
 252         if (strchr(argp->ypsetdom_domain, '/')) {
 253                 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
 254 rejecting.", argp->ypsetdom_domain);
 255                 return(NULL);
 256         }
 257         fromsin = svc_getcaller(transp);
 258
 259         switch (ypsetmode) {
 260         case YPSET_LOCAL:
 261                 if (fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) {
 262                         svcerr_noprog(transp);
 263                         return(NULL);
 264                 }
 265                 break;
 266         case YPSET_ALL:
 267                 break;
 268         case YPSET_NO:
 269         default:
 270                 svcerr_noprog(transp);
 271                 return(NULL);
 272         }
 273
 274         if (ntohs(fromsin->sin_port) >= IPPORT_RESERVED) {
 275                 svcerr_noprog(transp);
 276                 return(NULL);
 277         }
 278
 279         if (argp->ypsetdom_vers != YPVERS) {
 280                 svcerr_noprog(transp);
 281                 return(NULL);
 282         }
 283
 284         bzero((char *)&bindsin, sizeof bindsin);
 285         bindsin.sin_family = AF_INET;
 286         bindsin.sin_addr.s_addr = *(u_int32_t *)argp->ypsetdom_binding.ypbind_binding_addr;
 287         bindsin.sin_port = *(u_short *)argp->ypsetdom_binding.ypbind_binding_port;
 288         rpc_received(argp->ypsetdom_domain, &bindsin, 1);
 289
 290         return((void *) &result);
 291 }
 292
 293 static void
 294 ypbindprog_2(rqstp, transp)
 295 struct svc_req *rqstp;
 296 register SVCXPRT *transp;
 297 {
 298         union {
 299                 domainname ypbindproc_domain_2_arg;
 300                 struct ypbind_setdom ypbindproc_setdom_2_arg;
 301         } argument;
 302         struct authunix_parms *creds;
 303         char *result;
 304         bool_t (*xdr_argument)(), (*xdr_result)();
 305         char *(*local)();
 306
 307         switch (rqstp->rq_proc) {
 308         case YPBINDPROC_NULL:
 309                 xdr_argument = xdr_void;
 310                 xdr_result = xdr_void;
 311                 local = (char *(*)()) ypbindproc_null_2_yp;
 312                 break;
 313
 314         case YPBINDPROC_DOMAIN:
 315                 xdr_argument = xdr_domainname;
 316                 xdr_result = xdr_ypbind_resp;
 317                 local = (char *(*)()) ypbindproc_domain_2_yp;
 318                 break;
 319
 320         case YPBINDPROC_SETDOM:
 321                 switch (rqstp->rq_cred.oa_flavor) {
 322                 case AUTH_UNIX:
 323                         creds = (struct authunix_parms *)rqstp->rq_clntcred;
 324                         if (creds->aup_uid != 0) {
 325                                 svcerr_auth(transp, AUTH_BADCRED);
 326                                 return;
 327                         }
 328                         break;
 329                 default:
 330                         svcerr_auth(transp, AUTH_TOOWEAK);
 331                         return;
 332                 }
 333
 334                 xdr_argument = xdr_ypbind_setdom;
 335                 xdr_result = xdr_void;
 336                 local = (char *(*)()) ypbindproc_setdom_2_yp;
 337                 break;
 338
 339         default:
 340                 svcerr_noproc(transp);
 341                 return;
 342         }
 343         bzero((char *)&argument, sizeof(argument));
 344         if (!svc_getargs(transp, xdr_argument, (caddr_t)&argument)) {
 345                 svcerr_decode(transp);
 346                 return;
 347         }
 348         result = (*local)(transp, &argument, rqstp);
 349         if (result != NULL && !svc_sendreply(transp, xdr_result, result)) {
 350                 svcerr_systemerr(transp);
 351         }
 352         return;
 353 }
 354
 355 /* Jack the reaper */
 356 void reaper(sig)
 357 int sig;
 358 {
 359         int st;
 360
 361         while (wait3(&st, WNOHANG, NULL) > 0)
 362                 children--;
 363 }
 364
 365 void terminate(sig)
 366 int sig;
 367 {
 368         struct _dom_binding *ypdb;
 369         char path[MAXPATHLEN];
 370
 371         if (ppid != getpid())
 372                 exit(0);
 373
 374         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 375                 close(ypdb->dom_lockfd);
 376                 if (ypdb->dom_broadcast_pid)
 377                         kill(ypdb->dom_broadcast_pid, SIGINT);
 378                 sprintf(path, "%s/%s.%ld", BINDINGDIR,
 379                         ypdb->dom_domain, ypdb->dom_vers);
 380                 unlink(path);
 381         }
 382         close(yplockfd);
 383         unlink(YPBINDLOCK);
 384         pmap_unset(YPBINDPROG, YPBINDVERS);
 385         exit(0);
 386 }
 387
 388 int
 389 main(argc, argv)
 390 int argc;
 391 char **argv;
 392 {
 393         struct timeval tv;
 394         int i;
 395         DIR *dird;
 396         struct dirent *dirp;
 397         struct _dom_binding *ypdb, *next;
 398
 399         /* Check that another ypbind isn't already running. */
 400         if ((yplockfd = (open(YPBINDLOCK, O_RDONLY|O_CREAT, 0444))) == -1)
 401                 err(1, "%s", YPBINDLOCK);
 402
 403         if (flock(yplockfd, LOCK_EX|LOCK_NB) == -1 && errno == EWOULDBLOCK)
 404                 errx(1, "another ypbind is already running. Aborting");
 405
 406         /* XXX domainname will be overriden if we use restricted mode */
 407         yp_get_default_domain(&domain_name);
 408         if (domain_name[0] == '\0')
 409                 errx(1, "domainname not set. Aborting");
 410
 411         for (i = 1; i<argc; i++) {
 412                 if (strcmp("-ypset", argv[i]) == 0)
 413                         ypsetmode = YPSET_ALL;
 414                 else if (strcmp("-ypsetme", argv[i]) == 0)
 415                         ypsetmode = YPSET_LOCAL;
 416                 else if (strcmp("-s", argv[i]) == 0)
 417                         ypsecuremode++;
 418                 else if (strcmp("-S", argv[i]) == 0 && argc > i)
 419                         yp_restricted_mode(argv[i+1]);
 420                 else if (strcmp("-m", argv[i]) == 0)
 421                         yp_manycast++;
 422         }
 423
 424         /* blow away everything in BINDINGDIR (if it exists) */
 425
 426         if ((dird = opendir(BINDINGDIR)) != NULL) {
 427                 char path[MAXPATHLEN];
 428                 while ((dirp = readdir(dird)) != NULL)
 429                         if (strcmp(dirp->d_name, ".") &&
 430                             strcmp(dirp->d_name, "..")) {
 431                                 sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name);
 432                                 unlink(path);
 433                         }
 434                 closedir(dird);
 435         }
 436
 437 #ifdef DAEMON
 438         if (daemon(0,0))
 439                 err(1, "fork");
 440 #endif
 441
 442         pmap_unset(YPBINDPROG, YPBINDVERS);
 443
 444         udptransp = svcudp_create(RPC_ANYSOCK);
 445         if (udptransp == NULL)
 446                 errx(1, "cannot create udp service");
 447         if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 448             IPPROTO_UDP))
 449                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)");
 450
 451         tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0);
 452         if (tcptransp == NULL)
 453                 errx(1, "cannot create tcp service");
 454
 455         if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 456             IPPROTO_TCP))
 457                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)");
 458
 459         /* build initial domain binding, make it "unsuccessful" */
 460         ypbindlist = (struct _dom_binding *)malloc(sizeof *ypbindlist);
 461         if (ypbindlist == NULL)
 462                 errx(1, "malloc");
 463         bzero((char *)ypbindlist, sizeof *ypbindlist);
 464         strncpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain);
 465         ypbindlist->dom_vers = YPVERS;
 466         ypbindlist->dom_alive = 0;
 467         ypbindlist->dom_lockfd = -1;
 468         ypbindlist->dom_default = 1;
 469         domains++;
 470
 471         signal(SIGCHLD, reaper);
 472         signal(SIGTERM, terminate);
 473
 474         ppid = getpid(); /* Remember who we are. */
 475
 476         openlog(argv[0], LOG_PID, LOG_DAEMON);
 477
 478         /* Kick off the default domain */
 479         broadcast(ypbindlist);
 480
 481         while (1) {
 482                 fdsr = svc_fdset;
 483
 484                 tv.tv_sec = 60;
 485                 tv.tv_usec = 0;
 486
 487                 switch (select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) {
 488                 case 0:
 489                         checkwork();
 490                         break;
 491                 case -1:
 492                         if (errno != EINTR)
 493                                 syslog(LOG_WARNING, "select: %m");
 494                         break;
 495                 default:
 496                         for (ypdb = ypbindlist; ypdb; ypdb = next) {
 497                                 next = ypdb->dom_pnext;
 498                                 if (READFD > 0 && FD_ISSET(READFD, &fdsr)) {
 499                                         handle_children(ypdb);
 500                                         if (children == (MAX_CHILDREN - 1))
 501                                                 checkwork();
 502                                 }
 503                         }
 504                         svc_getreqset(&fdsr);
 505                         break;
 506                 }
 507         }
 508
 509         /* NOTREACHED */
 510         exit(1);
 511 }
 512
 513 void
 514 checkwork()
 515 {
 516         struct _dom_binding *ypdb;
 517
 518         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
 519                 ping(ypdb);
 520 }
 521
 522 /* The clnt_broadcast() callback mechanism sucks. */
 523
 524 /*
 525  * Receive results from broadcaster. Don't worry about passing
 526  * bogus info to rpc_received() -- it can handle it. Note that we
 527  * must be sure to invalidate the dom_pipe_fds descriptors here:
 528  * since descriptors can be re-used, we have to make sure we
 529  * don't mistake one of the RPC descriptors for one of the pipes.
 530  * What's weird is that forgetting to invalidate the pipe descriptors
 531  * doesn't always result in an error (otherwise I would have caught
 532  * the mistake much sooner), even though logically it should.
 533  */
 534 void handle_children(ypdb)
 535 struct _dom_binding *ypdb;
 536 {
 537         char buf[YPMAXDOMAIN + 1];
 538         struct sockaddr_in addr;
 539         int d = 0, a = 0;
 540         struct _dom_binding *y, *prev = NULL;
 541         char path[MAXPATHLEN];
 542
 543         if ((d = read(READFD, &buf, sizeof(buf))) <= 0)
 544                 syslog(LOG_WARNING, "could not read from child: %m");
 545
 546         if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0)
 547                 syslog(LOG_WARNING, "could not read from child: %m");
 548
 549         close(READFD);
 550         FD_CLR(READFD, &fdsr);
 551         FD_CLR(READFD, &svc_fdset);
 552         READFD = WRITEFD = -1;
 553         if (d > 0 && a > 0)
 554                 rpc_received((char *)&buf, &addr, 0);
 555         else {
 556                 for (y = ypbindlist; y; y = y->dom_pnext) {
 557                         if (y == ypdb)
 558                                 break;
 559                         prev = y;
 560                 }
 561                 switch (ypdb->dom_default) {
 562                 case 0:
 563                         if (prev == NULL)
 564                                 ypbindlist = y->dom_pnext;
 565                         else
 566                                 prev->dom_pnext = y->dom_pnext;
 567                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 568                                 ypdb->dom_domain, YPVERS);
 569                         close(ypdb->dom_lockfd);
 570                         unlink(path);
 571                         free(ypdb);
 572                         domains--;
 573                         return;
 574                 case 1:
 575                         ypdb->dom_broadcast_pid = 0;
 576                         ypdb->dom_alive = 0;
 577                         broadcast(ypdb);
 578                         return;
 579                 default:
 580                         break;
 581                 }
 582         }
 583
 584         return;
 585 }
 586
 587 /*
 588  * Send our dying words back to our parent before we perish.
 589  */
 590 int
 591 tell_parent(dom, addr)
 592 char *dom;
 593 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((char *)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 seperate
 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(ypdb)
 660 struct _dom_binding *ypdb;
 661 {
 662         bool_t out = FALSE;
 663         enum clnt_stat stat;
 664
 665         if (children >= MAX_CHILDREN || ypdb->dom_broadcast_pid)
 666                 return;
 667
 668         if (pipe(ypdb->dom_pipe_fds) < 0) {
 669                 syslog(LOG_WARNING, "pipe: %m");
 670                 return;
 671         }
 672
 673         if (ypdb->dom_vers == -1 && (long)ypdb->dom_server_addr.sin_addr.s_addr)
 674                 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding",
 675                 inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain);
 676
 677         broad_domain = ypdb;
 678         flock(ypdb->dom_lockfd, LOCK_UN);
 679
 680         switch ((ypdb->dom_broadcast_pid = fork())) {
 681         case 0:
 682                 close(READFD);
 683                 signal(SIGCHLD, SIG_DFL);
 684                 signal(SIGTERM, SIG_DFL);
 685                 break;
 686         case -1:
 687                 syslog(LOG_WARNING, "fork: %m");
 688                 close(READFD);
 689                 close(WRITEFD);
 690                 return;
 691         default:
 692                 close(WRITEFD);
 693                 FD_SET(READFD, &svc_fdset);
 694                 children++;
 695                 return;
 696         }
 697
 698         /* Release all locks before doing anything else. */
 699         while (ypbindlist) {
 700                 close(ypbindlist->dom_lockfd);
 701                 ypbindlist = ypbindlist->dom_pnext;
 702         }
 703         close(yplockfd);
 704
 705         /*
 706          * Special 'many-cast' behavior. If we're in restricted mode,
 707          * we have a list of possible server addresses to try. What
 708          * we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK
 709          * procedure and time the replies. Whoever replies fastest
 710          * gets to be our server. Note that this is not a broadcast
 711          * operation: we transmit uni-cast datagrams only.
 712          */
 713         if (yp_restricted && yp_manycast) {
 714                 short                   port;
 715                 int                     i;
 716                 struct sockaddr_in      sin;
 717
 718                 i = __yp_ping(restricted_addrs, yp_restricted,
 719                                 ypdb->dom_domain, &port);
 720                 if (i == -1) {
 721                         bzero((char *)&ypdb->dom_server_addr,
 722                                                 sizeof(struct sockaddr_in));
 723                         if (tell_parent(ypdb->dom_domain,
 724                                         &ypdb->dom_server_addr))
 725                         syslog(LOG_WARNING, "lost connection to parent");
 726                 } else {
 727                         bzero((char *)&sin, sizeof(struct sockaddr_in));
 728                         bcopy((char *)&restricted_addrs[i],
 729                                 (char *)&sin.sin_addr, sizeof(struct in_addr));
 730                         sin.sin_family = AF_INET;
 731                         sin.sin_port = port;
 732                         if (tell_parent(broad_domain->dom_domain, &sin))
 733                                 syslog(LOG_WARNING,
 734                                         "lost connection to parent");
 735                 }
 736                 _exit(0);
 737         }
 738
 739         retries = 0;
 740
 741         {
 742                 char *ptr;
 743
 744                 ptr = (char *)&ypdb->dom_domain;
 745                 stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK,
 746                         xdr_domainname, (char *)&ptr, xdr_bool, (char *)&out,
 747                         broadcast_result);
 748         }
 749
 750         if (stat != RPC_SUCCESS) {
 751                 bzero((char *)&ypdb->dom_server_addr,
 752                                                 sizeof(struct sockaddr_in));
 753                 if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr))
 754                         syslog(LOG_WARNING, "lost connection to parent");
 755         }
 756
 757         _exit(0);
 758 }
 759
 760 /*
 761  * The right way to check if a server is alive.
 762  * Attempt to get a client handle pointing to the server and send a
 763  * YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE,
 764  * we invalidate this binding entry and send out a broadcast to try to
 765  * establish a new binding. Note that we treat non-default domains
 766  * specially: once bound, we keep tabs on our server, but if it
 767  * goes away and fails to respond after one round of broadcasting, we
 768  * abandon it until a client specifically references it again. We make
 769  * every effort to keep our default domain bound, however, since we
 770  * need it to keep the system on its feet.
 771  */
 772 int
 773 ping(ypdb)
 774 struct _dom_binding *ypdb;
 775 {
 776         bool_t out;
 777         struct timeval interval, timeout;
 778         enum clnt_stat stat;
 779         int rpcsock = RPC_ANYSOCK;
 780         CLIENT *client_handle;
 781
 782         interval.tv_sec = FAIL_THRESHOLD;
 783         interval.tv_usec = 0;
 784         timeout.tv_sec = FAIL_THRESHOLD;
 785         timeout.tv_usec = 0;
 786
 787         if (ypdb->dom_broadcast_pid)
 788                 return(1);
 789
 790         if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr,
 791                 YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE,
 792                 RPCSMALLMSGSIZE)) == (CLIENT *)NULL) {
 793                 /* Can't get a handle: we're dead. */
 794                 ypdb->dom_alive = 0;
 795                 ypdb->dom_vers = -1;
 796                 broadcast(ypdb);
 797                 return(1);
 798         }
 799
 800         {
 801                 char *ptr;
 802
 803                 ptr = (char *)&ypdb->dom_domain;
 804
 805                 if ((stat = clnt_call(client_handle, YPPROC_DOMAIN,
 806                         xdr_domainname, (char *)&ptr, xdr_bool, (char *)&out,
 807                         timeout)) != RPC_SUCCESS || out == FALSE) {
 808                         ypdb->dom_alive = 0;
 809                         ypdb->dom_vers = -1;
 810                         clnt_destroy(client_handle);
 811                         broadcast(ypdb);
 812                         return(1);
 813                 }
 814         }
 815
 816         clnt_destroy(client_handle);
 817         return(0);
 818 }
 819
 820 void rpc_received(dom, raddrp, force)
 821 char *dom;
 822 struct sockaddr_in *raddrp;
 823 int force;
 824 {
 825         struct _dom_binding *ypdb, *prev = NULL;
 826         struct iovec iov[2];
 827         struct ypbind_resp ybr;
 828         char path[MAXPATHLEN];
 829         int fd;
 830
 831         /*printf("returned from %s/%d about %s\n", inet_ntoa(raddrp->sin_addr),
 832                ntohs(raddrp->sin_port), dom);*/
 833
 834         if (dom == NULL)
 835                 return;
 836
 837         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 838                 if (strcmp(ypdb->dom_domain, dom) == 0)
 839                         break;
 840                 prev = ypdb;
 841         }
 842
 843         if (ypdb && force) {
 844                 if (ypdb->dom_broadcast_pid) {
 845                         kill(ypdb->dom_broadcast_pid, SIGINT);
 846                         close(READFD);
 847                         FD_CLR(READFD, &fdsr);
 848                         FD_CLR(READFD, &svc_fdset);
 849                         READFD = WRITEFD = -1;
 850                 }
 851         }
 852
 853         /* if in secure mode, check originating port number */
 854         if ((ypsecuremode && (ntohs(raddrp->sin_port) >= IPPORT_RESERVED))) {
 855             syslog(LOG_WARNING, "Rejected NIS server on [%s/%d] for domain %s.",
 856                    inet_ntoa(raddrp->sin_addr), ntohs(raddrp->sin_port),
 857                    dom);
 858             if (ypdb != NULL) {
 859                 ypdb->dom_broadcast_pid = 0;
 860                 ypdb->dom_alive = 0;
 861             }
 862             return;
 863         }
 864
 865         if (raddrp->sin_addr.s_addr == (long)0) {
 866                 switch (ypdb->dom_default) {
 867                 case 0:
 868                         if (prev == NULL)
 869                                 ypbindlist = ypdb->dom_pnext;
 870                         else
 871                                 prev->dom_pnext = ypdb->dom_pnext;
 872                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 873                                 ypdb->dom_domain, YPVERS);
 874                         close(ypdb->dom_lockfd);
 875                         unlink(path);
 876                         free(ypdb);
 877                         domains--;
 878                         return;
 879                 case 1:
 880                         ypdb->dom_broadcast_pid = 0;
 881                         ypdb->dom_alive = 0;
 882                         broadcast(ypdb);
 883                         return;
 884                 default:
 885                         break;
 886                 }
 887         }
 888
 889         if (ypdb == NULL) {
 890                 if (force == 0)
 891                         return;
 892                 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb);
 893                 if (ypdb == NULL) {
 894                         syslog(LOG_WARNING, "malloc: %m");
 895                         return;
 896                 }
 897                 bzero((char *)ypdb, sizeof *ypdb);
 898                 strncpy(ypdb->dom_domain, dom, sizeof ypdb->dom_domain);
 899                 ypdb->dom_lockfd = -1;
 900                 ypdb->dom_default = 0;
 901                 ypdb->dom_pnext = ypbindlist;
 902                 ypbindlist = ypdb;
 903         }
 904
 905         /* We've recovered from a crash: inform the world. */
 906         if (ypdb->dom_vers == -1 && ypdb->dom_server_addr.sin_addr.s_addr)
 907                 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" OK",
 908                 inet_ntoa(raddrp->sin_addr), ypdb->dom_domain);
 909
 910         bcopy((char *)raddrp, (char *)&ypdb->dom_server_addr,
 911                 sizeof ypdb->dom_server_addr);
 912
 913         ypdb->dom_vers = YPVERS;
 914         ypdb->dom_alive = 1;
 915         ypdb->dom_broadcast_pid = 0;
 916
 917         if (ypdb->dom_lockfd != -1)
 918                 close(ypdb->dom_lockfd);
 919
 920         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 921                 ypdb->dom_domain, ypdb->dom_vers);
 922 #ifdef O_SHLOCK
 923         if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) {
 924                 (void)mkdir(BINDINGDIR, 0755);
 925                 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1)
 926                         return;
 927         }
 928 #else
 929         if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) {
 930                 (void)mkdir(BINDINGDIR, 0755);
 931                 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1)
 932                         return;
 933         }
 934         flock(fd, LOCK_SH);
 935 #endif
 936
 937         /*
 938          * ok, if BINDINGDIR exists, and we can create the binding file,
 939          * then write to it..
 940          */
 941         ypdb->dom_lockfd = fd;
 942
 943         iov[0].iov_base = (caddr_t)&(udptransp->xp_port);
 944         iov[0].iov_len = sizeof udptransp->xp_port;
 945         iov[1].iov_base = (caddr_t)&ybr;
 946         iov[1].iov_len = sizeof ybr;
 947
 948         bzero(&ybr, sizeof ybr);
 949         ybr.ypbind_status = YPBIND_SUCC_VAL;
 950         *(u_int32_t *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = raddrp->sin_addr.s_addr;
 951         *(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = raddrp->sin_port;
 952
 953         if (writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) {
 954                 syslog(LOG_WARNING, "write: %m");
 955                 close(ypdb->dom_lockfd);
 956                 ypdb->dom_lockfd = -1;
 957                 return;
 958         }
 959 }
 960
 961 /*
 962  * Check address against list of allowed servers. Return 0 if okay,
 963  * 1 if not matched.
 964  */
 965 int
 966 verify(addr)
 967 struct in_addr addr;
 968 {
 969         int i;
 970
 971         for (i = 0; i < RESTRICTED_SERVERS; i++)
 972                 if (!bcmp((char *)&addr, (char *)&restricted_addrs[i],
 973                         sizeof(struct in_addr)))
 974                         return(0);
 975
 976         return(1);
 977 }
 978
 979 /*
 980  * Try to set restricted mode. We default to normal mode if we can't
 981  * resolve the specified hostnames.
 982  */
 983 void
 984 yp_restricted_mode(args)
 985 char *args;
 986 {
 987         struct hostent *h;
 988         int i = 0;
 989         char *s;
 990
 991         /* Find the restricted domain. */
 992         if ((s = strsep(&args, ",")) == NULL)
 993                 return;
 994         domain_name = s;
 995
 996         /* Get the addresses of the servers. */
 997         while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) {
 998                 if ((h = gethostbyname(s)) == NULL)
 999                         return;
1000                 bcopy ((char *)h->h_addr_list[0], (char *)&restricted_addrs[i],
1001                         sizeof(struct in_addr));
1002         i++;
1003         }
1004
1005         /* ypset and ypsetme not allowed with restricted mode */
1006         ypsetmode = YPSET_NO;
1007
1008         yp_restricted = i;
1009         return;
1010 }