usr.sbin/ypbind/ypbind.c

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