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  * $FreeBSD: src/usr.sbin/ypbind/ypbind.c,v 1.30.2.2 2002/02/15 00:46:59 des Exp $
  30  * $DragonFly: src/usr.sbin/ypbind/ypbind.c,v 1.2 2003/06/17 04:30:04 dillon Exp $
  31  */
  32
  33 #include <sys/param.h>
  34 #include <sys/types.h>
  35 #include <sys/wait.h>
  36 #include <sys/ioctl.h>
  37 #include <sys/signal.h>
  38 #include <sys/socket.h>
  39 #include <sys/file.h>
  40 #include <sys/fcntl.h>
  41 #include <sys/stat.h>
  42 #include <sys/uio.h>
  43 #include <ctype.h>
  44 #include <dirent.h>
  45 #include <err.h>
  46 #include <errno.h>
  47 #include <netdb.h>
  48 #include <signal.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include <syslog.h>
  53 #include <unistd.h>
  54 #include <rpc/rpc.h>
  55 #include <rpc/xdr.h>
  56 #include <net/if.h>
  57 #include <netinet/in.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 <rpc/rpc_com.h>
  63 #include <rpcsvc/yp.h>
  64 struct dom_binding{};
  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 /*
 121  * Special restricted mode variables: when in restricted mode, only the
 122  * specified restricted_domain will be bound, and only the servers listed
 123  * in restricted_addrs will be used for binding.
 124  */
 125 #define RESTRICTED_SERVERS 10
 126 int yp_restricted = 0;
 127 int yp_manycast = 0;
 128 struct in_addr restricted_addrs[RESTRICTED_SERVERS];
 129
 130 /* No more than MAX_CHILDREN child broadcasters at a time. */
 131 #ifndef MAX_CHILDREN
 132 #define MAX_CHILDREN 5
 133 #endif
 134 /* No more than MAX_DOMAINS simultaneous domains */
 135 #ifndef MAX_DOMAINS
 136 #define MAX_DOMAINS 200
 137 #endif
 138 /* RPC timeout value */
 139 #ifndef FAIL_THRESHOLD
 140 #define FAIL_THRESHOLD 20
 141 #endif
 142
 143 /* Number of times to fish for a response froma particular set of hosts */
 144 #ifndef MAX_RETRIES
 145 #define MAX_RETRIES 30
 146 #endif
 147
 148 int retries = 0;
 149 int children = 0;
 150 int domains = 0;
 151 int yplockfd;
 152 fd_set fdsr;
 153
 154 SVCXPRT *udptransp, *tcptransp;
 155
 156 void *
 157 ypbindproc_null_2_yp(transp, argp, clnt)
 158 SVCXPRT *transp;
 159 void *argp;
 160 CLIENT *clnt;
 161 {
 162         static char res;
 163
 164         bzero((char *)&res, sizeof(res));
 165         return (void *)&res;
 166 }
 167
 168 struct ypbind_resp *
 169 ypbindproc_domain_2_yp(transp, argp, clnt)
 170 SVCXPRT *transp;
 171 domainname *argp;
 172 CLIENT *clnt;
 173 {
 174         static struct ypbind_resp res;
 175         struct _dom_binding *ypdb;
 176         char path[MAXPATHLEN];
 177
 178         bzero((char *)&res, sizeof res);
 179         res.ypbind_status = YPBIND_FAIL_VAL;
 180         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_NOSERV;
 181
 182         if (strchr(*argp, '/')) {
 183                 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
 184 rejecting.", *argp);
 185                 return(&res);
 186         }
 187
 188         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 189                 if (strcmp(ypdb->dom_domain, *argp) == 0)
 190                         break;
 191                 }
 192
 193         if (ypdb == NULL) {
 194                 if (yp_restricted) {
 195                         syslog(LOG_NOTICE, "Running in restricted mode -- request to bind domain \"%s\" rejected.\n", *argp);
 196                         return (&res);
 197                 }
 198
 199                 if (domains >= MAX_DOMAINS) {
 200                         syslog(LOG_WARNING, "domain limit (%d) exceeded",
 201                                                         MAX_DOMAINS);
 202                         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
 203                         return (&res);
 204                 }
 205                 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb);
 206                 if (ypdb == NULL) {
 207                         syslog(LOG_WARNING, "malloc: %m");
 208                         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
 209                         return (&res);
 210                 }
 211                 bzero((char *)ypdb, sizeof *ypdb);
 212                 strncpy(ypdb->dom_domain, *argp, sizeof ypdb->dom_domain);
 213                 ypdb->dom_vers = YPVERS;
 214                 ypdb->dom_alive = 0;
 215                 ypdb->dom_default = 0;
 216                 ypdb->dom_lockfd = -1;
 217                 sprintf(path, "%s/%s.%ld", BINDINGDIR,
 218                                         ypdb->dom_domain, ypdb->dom_vers);
 219                 unlink(path);
 220                 ypdb->dom_pnext = ypbindlist;
 221                 ypbindlist = ypdb;
 222                 domains++;
 223         }
 224
 225         if (ping(ypdb)) {
 226                 return (&res);
 227         }
 228
 229         res.ypbind_status = YPBIND_SUCC_VAL;
 230         res.ypbind_resp_u.ypbind_error = 0; /* Success */
 231         *(u_int32_t *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr =
 232                 ypdb->dom_server_addr.sin_addr.s_addr;
 233         *(u_short *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port =
 234                 ypdb->dom_server_addr.sin_port;
 235         /*printf("domain %s at %s/%d\n", ypdb->dom_domain,
 236                 inet_ntoa(ypdb->dom_server_addr.sin_addr),
 237                 ntohs(ypdb->dom_server_addr.sin_port));*/
 238         return (&res);
 239 }
 240
 241 void *
 242 ypbindproc_setdom_2_yp(transp, argp, clnt)
 243 SVCXPRT *transp;
 244 ypbind_setdom *argp;
 245 CLIENT *clnt;
 246 {
 247         struct sockaddr_in *fromsin, bindsin;
 248         static char             *result = NULL;
 249
 250         if (strchr(argp->ypsetdom_domain, '/')) {
 251                 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
 252 rejecting.", argp->ypsetdom_domain);
 253                 return(NULL);
 254         }
 255         fromsin = svc_getcaller(transp);
 256
 257         switch (ypsetmode) {
 258         case YPSET_LOCAL:
 259                 if (fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) {
 260                         svcerr_noprog(transp);
 261                         return(NULL);
 262                 }
 263                 break;
 264         case YPSET_ALL:
 265                 break;
 266         case YPSET_NO:
 267         default:
 268                 svcerr_noprog(transp);
 269                 return(NULL);
 270         }
 271
 272         if (ntohs(fromsin->sin_port) >= IPPORT_RESERVED) {
 273                 svcerr_noprog(transp);
 274                 return(NULL);
 275         }
 276
 277         if (argp->ypsetdom_vers != YPVERS) {
 278                 svcerr_noprog(transp);
 279                 return(NULL);
 280         }
 281
 282         bzero((char *)&bindsin, sizeof bindsin);
 283         bindsin.sin_family = AF_INET;
 284         bindsin.sin_addr.s_addr = *(u_int32_t *)argp->ypsetdom_binding.ypbind_binding_addr;
 285         bindsin.sin_port = *(u_short *)argp->ypsetdom_binding.ypbind_binding_port;
 286         rpc_received(argp->ypsetdom_domain, &bindsin, 1);
 287
 288         return((void *) &result);
 289 }
 290
 291 static void
 292 ypbindprog_2(rqstp, transp)
 293 struct svc_req *rqstp;
 294 register SVCXPRT *transp;
 295 {
 296         union {
 297                 domainname ypbindproc_domain_2_arg;
 298                 struct ypbind_setdom ypbindproc_setdom_2_arg;
 299         } argument;
 300         struct authunix_parms *creds;
 301         char *result;
 302         bool_t (*xdr_argument)(), (*xdr_result)();
 303         char *(*local)();
 304
 305         switch (rqstp->rq_proc) {
 306         case YPBINDPROC_NULL:
 307                 xdr_argument = xdr_void;
 308                 xdr_result = xdr_void;
 309                 local = (char *(*)()) ypbindproc_null_2_yp;
 310                 break;
 311
 312         case YPBINDPROC_DOMAIN:
 313                 xdr_argument = xdr_domainname;
 314                 xdr_result = xdr_ypbind_resp;
 315                 local = (char *(*)()) ypbindproc_domain_2_yp;
 316                 break;
 317
 318         case YPBINDPROC_SETDOM:
 319                 switch (rqstp->rq_cred.oa_flavor) {
 320                 case AUTH_UNIX:
 321                         creds = (struct authunix_parms *)rqstp->rq_clntcred;
 322                         if (creds->aup_uid != 0) {
 323                                 svcerr_auth(transp, AUTH_BADCRED);
 324                                 return;
 325                         }
 326                         break;
 327                 default:
 328                         svcerr_auth(transp, AUTH_TOOWEAK);
 329                         return;
 330                 }
 331
 332                 xdr_argument = xdr_ypbind_setdom;
 333                 xdr_result = xdr_void;
 334                 local = (char *(*)()) ypbindproc_setdom_2_yp;
 335                 break;
 336
 337         default:
 338                 svcerr_noproc(transp);
 339                 return;
 340         }
 341         bzero((char *)&argument, sizeof(argument));
 342         if (!svc_getargs(transp, xdr_argument, (caddr_t)&argument)) {
 343                 svcerr_decode(transp);
 344                 return;
 345         }
 346         result = (*local)(transp, &argument, rqstp);
 347         if (result != NULL && !svc_sendreply(transp, xdr_result, result)) {
 348                 svcerr_systemerr(transp);
 349         }
 350         return;
 351 }
 352
 353 /* Jack the reaper */
 354 void reaper(sig)
 355 int sig;
 356 {
 357         int st;
 358
 359         while (wait3(&st, WNOHANG, NULL) > 0)
 360                 children--;
 361 }
 362
 363 void terminate(sig)
 364 int sig;
 365 {
 366         struct _dom_binding *ypdb;
 367         char path[MAXPATHLEN];
 368
 369         if (ppid != getpid())
 370                 exit(0);
 371
 372         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 373                 close(ypdb->dom_lockfd);
 374                 if (ypdb->dom_broadcast_pid)
 375                         kill(ypdb->dom_broadcast_pid, SIGINT);
 376                 sprintf(path, "%s/%s.%ld", BINDINGDIR,
 377                         ypdb->dom_domain, ypdb->dom_vers);
 378                 unlink(path);
 379         }
 380         close(yplockfd);
 381         unlink(YPBINDLOCK);
 382         pmap_unset(YPBINDPROG, YPBINDVERS);
 383         exit(0);
 384 }
 385
 386 int
 387 main(argc, argv)
 388 int argc;
 389 char **argv;
 390 {
 391         struct timeval tv;
 392         int i;
 393         DIR *dird;
 394         struct dirent *dirp;
 395         struct _dom_binding *ypdb, *next;
 396
 397         /* Check that another ypbind isn't already running. */
 398         if ((yplockfd = (open(YPBINDLOCK, O_RDONLY|O_CREAT, 0444))) == -1)
 399                 err(1, "%s", YPBINDLOCK);
 400
 401         if (flock(yplockfd, LOCK_EX|LOCK_NB) == -1 && errno == EWOULDBLOCK)
 402                 errx(1, "another ypbind is already running. Aborting");
 403
 404         /* XXX domainname will be overriden if we use restricted mode */
 405         yp_get_default_domain(&domain_name);
 406         if (domain_name[0] == '\0')
 407                 errx(1, "domainname not set. Aborting");
 408
 409         for (i = 1; i<argc; i++) {
 410                 if (strcmp("-ypset", argv[i]) == 0)
 411                         ypsetmode = YPSET_ALL;
 412                 else if (strcmp("-ypsetme", argv[i]) == 0)
 413                         ypsetmode = YPSET_LOCAL;
 414                 else if (strcmp("-s", argv[i]) == 0)
 415                         ypsecuremode++;
 416                 else if (strcmp("-S", argv[i]) == 0 && argc > i)
 417                         yp_restricted_mode(argv[i+1]);
 418                 else if (strcmp("-m", argv[i]) == 0)
 419                         yp_manycast++;
 420         }
 421
 422         /* blow away everything in BINDINGDIR (if it exists) */
 423
 424         if ((dird = opendir(BINDINGDIR)) != NULL) {
 425                 char path[MAXPATHLEN];
 426                 while ((dirp = readdir(dird)) != NULL)
 427                         if (strcmp(dirp->d_name, ".") &&
 428                             strcmp(dirp->d_name, "..")) {
 429                                 sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name);
 430                                 unlink(path);
 431                         }
 432                 closedir(dird);
 433         }
 434
 435 #ifdef DAEMON
 436         if (daemon(0,0))
 437                 err(1, "fork");
 438 #endif
 439
 440         pmap_unset(YPBINDPROG, YPBINDVERS);
 441
 442         udptransp = svcudp_create(RPC_ANYSOCK);
 443         if (udptransp == NULL)
 444                 errx(1, "cannot create udp service");
 445         if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 446             IPPROTO_UDP))
 447                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)");
 448
 449         tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0);
 450         if (tcptransp == NULL)
 451                 errx(1, "cannot create tcp service");
 452
 453         if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 454             IPPROTO_TCP))
 455                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)");
 456
 457         /* build initial domain binding, make it "unsuccessful" */
 458         ypbindlist = (struct _dom_binding *)malloc(sizeof *ypbindlist);
 459         if (ypbindlist == NULL)
 460                 errx(1, "malloc");
 461         bzero((char *)ypbindlist, sizeof *ypbindlist);
 462         strncpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain);
 463         ypbindlist->dom_vers = YPVERS;
 464         ypbindlist->dom_alive = 0;
 465         ypbindlist->dom_lockfd = -1;
 466         ypbindlist->dom_default = 1;
 467         domains++;
 468
 469         signal(SIGCHLD, reaper);
 470         signal(SIGTERM, terminate);
 471
 472         ppid = getpid(); /* Remember who we are. */
 473
 474         openlog(argv[0], LOG_PID, LOG_DAEMON);
 475
 476         /* Kick off the default domain */
 477         broadcast(ypbindlist);
 478
 479         while (1) {
 480                 fdsr = svc_fdset;
 481
 482                 tv.tv_sec = 60;
 483                 tv.tv_usec = 0;
 484
 485                 switch (select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) {
 486                 case 0:
 487                         checkwork();
 488                         break;
 489                 case -1:
 490                         if (errno != EINTR)
 491                                 syslog(LOG_WARNING, "select: %m");
 492                         break;
 493                 default:
 494                         for (ypdb = ypbindlist; ypdb; ypdb = next) {
 495                                 next = ypdb->dom_pnext;
 496                                 if (READFD > 0 && FD_ISSET(READFD, &fdsr)) {
 497                                         handle_children(ypdb);
 498                                         if (children == (MAX_CHILDREN - 1))
 499                                                 checkwork();
 500                                 }
 501                         }
 502                         svc_getreqset(&fdsr);
 503                         break;
 504                 }
 505         }
 506
 507         /* NOTREACHED */
 508         exit(1);
 509 }
 510
 511 void
 512 checkwork()
 513 {
 514         struct _dom_binding *ypdb;
 515
 516         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
 517                 ping(ypdb);
 518 }
 519
 520 /* The clnt_broadcast() callback mechanism sucks. */
 521
 522 /*
 523  * Receive results from broadcaster. Don't worry about passing
 524  * bogus info to rpc_received() -- it can handle it. Note that we
 525  * must be sure to invalidate the dom_pipe_fds descriptors here:
 526  * since descriptors can be re-used, we have to make sure we
 527  * don't mistake one of the RPC descriptors for one of the pipes.
 528  * What's weird is that forgetting to invalidate the pipe descriptors
 529  * doesn't always result in an error (otherwise I would have caught
 530  * the mistake much sooner), even though logically it should.
 531  */
 532 void handle_children(ypdb)
 533 struct _dom_binding *ypdb;
 534 {
 535         char buf[YPMAXDOMAIN + 1];
 536         struct sockaddr_in addr;
 537         int d = 0, a = 0;
 538         struct _dom_binding *y, *prev = NULL;
 539         char path[MAXPATHLEN];
 540
 541         if ((d = read(READFD, &buf, sizeof(buf))) <= 0)
 542                 syslog(LOG_WARNING, "could not read from child: %m");
 543
 544         if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0)
 545                 syslog(LOG_WARNING, "could not read from child: %m");
 546
 547         close(READFD);
 548         FD_CLR(READFD, &fdsr);
 549         FD_CLR(READFD, &svc_fdset);
 550         READFD = WRITEFD = -1;
 551         if (d > 0 && a > 0)
 552                 rpc_received((char *)&buf, &addr, 0);
 553         else {
 554                 for (y = ypbindlist; y; y = y->dom_pnext) {
 555                         if (y == ypdb)
 556                                 break;
 557                         prev = y;
 558                 }
 559                 switch (ypdb->dom_default) {
 560                 case 0:
 561                         if (prev == NULL)
 562                                 ypbindlist = y->dom_pnext;
 563                         else
 564                                 prev->dom_pnext = y->dom_pnext;
 565                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 566                                 ypdb->dom_domain, YPVERS);
 567                         close(ypdb->dom_lockfd);
 568                         unlink(path);
 569                         free(ypdb);
 570                         domains--;
 571                         return;
 572                 case 1:
 573                         ypdb->dom_broadcast_pid = 0;
 574                         ypdb->dom_alive = 0;
 575                         broadcast(ypdb);
 576                         return;
 577                 default:
 578                         break;
 579                 }
 580         }
 581
 582         return;
 583 }
 584
 585 /*
 586  * Send our dying words back to our parent before we perish.
 587  */
 588 int
 589 tell_parent(dom, addr)
 590 char *dom;
 591 struct sockaddr_in *addr;
 592 {
 593         char buf[YPMAXDOMAIN + 1];
 594         struct timeval timeout;
 595         fd_set fds;
 596
 597         timeout.tv_sec = 5;
 598         timeout.tv_usec = 0;
 599
 600         sprintf(buf, "%s", broad_domain->dom_domain);
 601         if (write(BROADFD, &buf, sizeof(buf)) < 0)
 602                 return(1);
 603
 604         /*
 605          * Stay in sync with parent: wait for it to read our first
 606          * message before sending the second.
 607          */
 608
 609         FD_ZERO(&fds);
 610         FD_SET(BROADFD, &fds);
 611         if (select(FD_SETSIZE, NULL, &fds, NULL, &timeout) == -1)
 612                 return(1);
 613         if (FD_ISSET(BROADFD, &fds)) {
 614                 if (write(BROADFD, addr, sizeof(struct sockaddr_in)) < 0)
 615                         return(1);
 616         } else {
 617                 return(1);
 618         }
 619
 620         close(BROADFD);
 621         return (0);
 622 }
 623
 624 bool_t broadcast_result(out, addr)
 625 bool_t *out;
 626 struct sockaddr_in *addr;
 627 {
 628         if (retries >= MAX_RETRIES) {
 629                 bzero((char *)addr, sizeof(struct sockaddr_in));
 630                 if (tell_parent(broad_domain->dom_domain, addr))
 631                         syslog(LOG_WARNING, "lost connection to parent");
 632                 return (TRUE);
 633         }
 634
 635         if (yp_restricted && verify(addr->sin_addr)) {
 636                 retries++;
 637                 syslog(LOG_NOTICE, "NIS server at %s not in restricted mode access list -- rejecting.\n",inet_ntoa(addr->sin_addr));
 638                 return (FALSE);
 639         } else {
 640                 if (tell_parent(broad_domain->dom_domain, addr))
 641                         syslog(LOG_WARNING, "lost connection to parent");
 642                 return (TRUE);
 643         }
 644 }
 645
 646 /*
 647  * The right way to send RPC broadcasts.
 648  * Use the clnt_broadcast() RPC service. Unfortunately, clnt_broadcast()
 649  * blocks while waiting for replies, so we have to fork off seperate
 650  * broadcaster processes that do the waiting and then transmit their
 651  * results back to the parent for processing. We also have to remember
 652  * to save the name of the domain we're trying to bind in a global
 653  * variable since clnt_broadcast() provides no way to pass things to
 654  * the 'eachresult' callback function.
 655  */
 656 void
 657 broadcast(ypdb)
 658 struct _dom_binding *ypdb;
 659 {
 660         bool_t out = FALSE;
 661         enum clnt_stat stat;
 662
 663         if (children >= MAX_CHILDREN || ypdb->dom_broadcast_pid)
 664                 return;
 665
 666         if (pipe(ypdb->dom_pipe_fds) < 0) {
 667                 syslog(LOG_WARNING, "pipe: %m");
 668                 return;
 669         }
 670
 671         if (ypdb->dom_vers == -1 && (long)ypdb->dom_server_addr.sin_addr.s_addr)
 672                 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding",
 673                 inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain);
 674
 675         broad_domain = ypdb;
 676         flock(ypdb->dom_lockfd, LOCK_UN);
 677
 678         switch ((ypdb->dom_broadcast_pid = fork())) {
 679         case 0:
 680                 close(READFD);
 681                 signal(SIGCHLD, SIG_DFL);
 682                 signal(SIGTERM, SIG_DFL);
 683                 break;
 684         case -1:
 685                 syslog(LOG_WARNING, "fork: %m");
 686                 close(READFD);
 687                 close(WRITEFD);
 688                 return;
 689         default:
 690                 close(WRITEFD);
 691                 FD_SET(READFD, &svc_fdset);
 692                 children++;
 693                 return;
 694         }
 695
 696         /* Release all locks before doing anything else. */
 697         while (ypbindlist) {
 698                 close(ypbindlist->dom_lockfd);
 699                 ypbindlist = ypbindlist->dom_pnext;
 700         }
 701         close(yplockfd);
 702
 703         /*
 704          * Special 'many-cast' behavior. If we're in restricted mode,
 705          * we have a list of possible server addresses to try. What
 706          * we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK
 707          * procedure and time the replies. Whoever replies fastest
 708          * gets to be our server. Note that this is not a broadcast
 709          * operation: we transmit uni-cast datagrams only.
 710          */
 711         if (yp_restricted && yp_manycast) {
 712                 short                   port;
 713                 int                     i;
 714                 struct sockaddr_in      sin;
 715
 716                 i = __yp_ping(restricted_addrs, yp_restricted,
 717                                 ypdb->dom_domain, &port);
 718                 if (i == -1) {
 719                         bzero((char *)&ypdb->dom_server_addr,
 720                                                 sizeof(struct sockaddr_in));
 721                         if (tell_parent(ypdb->dom_domain,
 722                                         &ypdb->dom_server_addr))
 723                         syslog(LOG_WARNING, "lost connection to parent");
 724                 } else {
 725                         bzero((char *)&sin, sizeof(struct sockaddr_in));
 726                         bcopy((char *)&restricted_addrs[i],
 727                                 (char *)&sin.sin_addr, sizeof(struct in_addr));
 728                         sin.sin_family = AF_INET;
 729                         sin.sin_port = port;
 730                         if (tell_parent(broad_domain->dom_domain, &sin))
 731                                 syslog(LOG_WARNING,
 732                                         "lost connection to parent");
 733                 }
 734                 _exit(0);
 735         }
 736
 737         retries = 0;
 738
 739         {
 740                 char *ptr;
 741
 742                 ptr = (char *)&ypdb->dom_domain;
 743                 stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK,
 744                         xdr_domainname, (char *)&ptr, xdr_bool, (char *)&out,
 745                         broadcast_result);
 746         }
 747
 748         if (stat != RPC_SUCCESS) {
 749                 bzero((char *)&ypdb->dom_server_addr,
 750                                                 sizeof(struct sockaddr_in));
 751                 if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr))
 752                         syslog(LOG_WARNING, "lost connection to parent");
 753         }
 754
 755         _exit(0);
 756 }
 757
 758 /*
 759  * The right way to check if a server is alive.
 760  * Attempt to get a client handle pointing to the server and send a
 761  * YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE,
 762  * we invalidate this binding entry and send out a broadcast to try to
 763  * establish a new binding. Note that we treat non-default domains
 764  * specially: once bound, we keep tabs on our server, but if it
 765  * goes away and fails to respond after one round of broadcasting, we
 766  * abandon it until a client specifically references it again. We make
 767  * every effort to keep our default domain bound, however, since we
 768  * need it to keep the system on its feet.
 769  */
 770 int
 771 ping(ypdb)
 772 struct _dom_binding *ypdb;
 773 {
 774         bool_t out;
 775         struct timeval interval, timeout;
 776         enum clnt_stat stat;
 777         int rpcsock = RPC_ANYSOCK;
 778         CLIENT *client_handle;
 779
 780         interval.tv_sec = FAIL_THRESHOLD;
 781         interval.tv_usec = 0;
 782         timeout.tv_sec = FAIL_THRESHOLD;
 783         timeout.tv_usec = 0;
 784
 785         if (ypdb->dom_broadcast_pid)
 786                 return(1);
 787
 788         if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr,
 789                 YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE,
 790                 RPCSMALLMSGSIZE)) == (CLIENT *)NULL) {
 791                 /* Can't get a handle: we're dead. */
 792                 ypdb->dom_alive = 0;
 793                 ypdb->dom_vers = -1;
 794                 broadcast(ypdb);
 795                 return(1);
 796         }
 797
 798         {
 799                 char *ptr;
 800
 801                 ptr = (char *)&ypdb->dom_domain;
 802
 803                 if ((stat = clnt_call(client_handle, YPPROC_DOMAIN,
 804                         xdr_domainname, (char *)&ptr, xdr_bool, (char *)&out,
 805                         timeout)) != RPC_SUCCESS || out == FALSE) {
 806                         ypdb->dom_alive = 0;
 807                         ypdb->dom_vers = -1;
 808                         clnt_destroy(client_handle);
 809                         broadcast(ypdb);
 810                         return(1);
 811                 }
 812         }
 813
 814         clnt_destroy(client_handle);
 815         return(0);
 816 }
 817
 818 void rpc_received(dom, raddrp, force)
 819 char *dom;
 820 struct sockaddr_in *raddrp;
 821 int force;
 822 {
 823         struct _dom_binding *ypdb, *prev = NULL;
 824         struct iovec iov[2];
 825         struct ypbind_resp ybr;
 826         char path[MAXPATHLEN];
 827         int fd;
 828
 829         /*printf("returned from %s/%d about %s\n", inet_ntoa(raddrp->sin_addr),
 830                ntohs(raddrp->sin_port), dom);*/
 831
 832         if (dom == NULL)
 833                 return;
 834
 835         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 836                 if (strcmp(ypdb->dom_domain, dom) == 0)
 837                         break;
 838                 prev = ypdb;
 839         }
 840
 841         if (ypdb && force) {
 842                 if (ypdb->dom_broadcast_pid) {
 843                         kill(ypdb->dom_broadcast_pid, SIGINT);
 844                         close(READFD);
 845                         FD_CLR(READFD, &fdsr);
 846                         FD_CLR(READFD, &svc_fdset);
 847                         READFD = WRITEFD = -1;
 848                 }
 849         }
 850
 851         /* if in secure mode, check originating port number */
 852         if ((ypsecuremode && (ntohs(raddrp->sin_port) >= IPPORT_RESERVED))) {
 853             syslog(LOG_WARNING, "Rejected NIS server on [%s/%d] for domain %s.",
 854                    inet_ntoa(raddrp->sin_addr), ntohs(raddrp->sin_port),
 855                    dom);
 856             if (ypdb != NULL) {
 857                 ypdb->dom_broadcast_pid = 0;
 858                 ypdb->dom_alive = 0;
 859             }
 860             return;
 861         }
 862
 863         if (raddrp->sin_addr.s_addr == (long)0) {
 864                 switch (ypdb->dom_default) {
 865                 case 0:
 866                         if (prev == NULL)
 867                                 ypbindlist = ypdb->dom_pnext;
 868                         else
 869                                 prev->dom_pnext = ypdb->dom_pnext;
 870                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 871                                 ypdb->dom_domain, YPVERS);
 872                         close(ypdb->dom_lockfd);
 873                         unlink(path);
 874                         free(ypdb);
 875                         domains--;
 876                         return;
 877                 case 1:
 878                         ypdb->dom_broadcast_pid = 0;
 879                         ypdb->dom_alive = 0;
 880                         broadcast(ypdb);
 881                         return;
 882                 default:
 883                         break;
 884                 }
 885         }
 886
 887         if (ypdb == NULL) {
 888                 if (force == 0)
 889                         return;
 890                 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb);
 891                 if (ypdb == NULL) {
 892                         syslog(LOG_WARNING, "malloc: %m");
 893                         return;
 894                 }
 895                 bzero((char *)ypdb, sizeof *ypdb);
 896                 strncpy(ypdb->dom_domain, dom, sizeof ypdb->dom_domain);
 897                 ypdb->dom_lockfd = -1;
 898                 ypdb->dom_default = 0;
 899                 ypdb->dom_pnext = ypbindlist;
 900                 ypbindlist = ypdb;
 901         }
 902
 903         /* We've recovered from a crash: inform the world. */
 904         if (ypdb->dom_vers == -1 && ypdb->dom_server_addr.sin_addr.s_addr)
 905                 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" OK",
 906                 inet_ntoa(raddrp->sin_addr), ypdb->dom_domain);
 907
 908         bcopy((char *)raddrp, (char *)&ypdb->dom_server_addr,
 909                 sizeof ypdb->dom_server_addr);
 910
 911         ypdb->dom_vers = YPVERS;
 912         ypdb->dom_alive = 1;
 913         ypdb->dom_broadcast_pid = 0;
 914
 915         if (ypdb->dom_lockfd != -1)
 916                 close(ypdb->dom_lockfd);
 917
 918         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 919                 ypdb->dom_domain, ypdb->dom_vers);
 920 #ifdef O_SHLOCK
 921         if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) {
 922                 (void)mkdir(BINDINGDIR, 0755);
 923                 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1)
 924                         return;
 925         }
 926 #else
 927         if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) {
 928                 (void)mkdir(BINDINGDIR, 0755);
 929                 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1)
 930                         return;
 931         }
 932         flock(fd, LOCK_SH);
 933 #endif
 934
 935         /*
 936          * ok, if BINDINGDIR exists, and we can create the binding file,
 937          * then write to it..
 938          */
 939         ypdb->dom_lockfd = fd;
 940
 941         iov[0].iov_base = (caddr_t)&(udptransp->xp_port);
 942         iov[0].iov_len = sizeof udptransp->xp_port;
 943         iov[1].iov_base = (caddr_t)&ybr;
 944         iov[1].iov_len = sizeof ybr;
 945
 946         bzero(&ybr, sizeof ybr);
 947         ybr.ypbind_status = YPBIND_SUCC_VAL;
 948         *(u_int32_t *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = raddrp->sin_addr.s_addr;
 949         *(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = raddrp->sin_port;
 950
 951         if (writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) {
 952                 syslog(LOG_WARNING, "write: %m");
 953                 close(ypdb->dom_lockfd);
 954                 ypdb->dom_lockfd = -1;
 955                 return;
 956         }
 957 }
 958
 959 /*
 960  * Check address against list of allowed servers. Return 0 if okay,
 961  * 1 if not matched.
 962  */
 963 int
 964 verify(addr)
 965 struct in_addr addr;
 966 {
 967         int i;
 968
 969         for (i = 0; i < RESTRICTED_SERVERS; i++)
 970                 if (!bcmp((char *)&addr, (char *)&restricted_addrs[i],
 971                         sizeof(struct in_addr)))
 972                         return(0);
 973
 974         return(1);
 975 }
 976
 977 /*
 978  * Try to set restricted mode. We default to normal mode if we can't
 979  * resolve the specified hostnames.
 980  */
 981 void
 982 yp_restricted_mode(args)
 983 char *args;
 984 {
 985         struct hostent *h;
 986         int i = 0;
 987         char *s;
 988
 989         /* Find the restricted domain. */
 990         if ((s = strsep(&args, ",")) == NULL)
 991                 return;
 992         domain_name = s;
 993
 994         /* Get the addresses of the servers. */
 995         while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) {
 996                 if ((h = gethostbyname(s)) == NULL)
 997                         return;
 998                 bcopy ((char *)h->h_addr_list[0], (char *)&restricted_addrs[i],
 999                         sizeof(struct in_addr));
1000         i++;
1001         }
1002
1003         /* ypset and ypsetme not allowed with restricted mode */
1004         ypsetmode = YPSET_NO;
1005
1006         yp_restricted = i;
1007         return;
1008 }