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