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