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(&res, sizeof(res));
 164         return &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(&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(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(&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 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(&argument, sizeof(argument));
 333         if (!svc_getargs(transp, (xdrproc_t)xdr_argument, &argument)) {
 334                 svcerr_decode(transp);
 335                 return;
 336         }
 337         result = (*local)(transp, &argument, rqstp);
 338         if (result != NULL &&
 339             !svc_sendreply(transp, (xdrproc_t)xdr_result, result)) {
 340                 svcerr_systemerr(transp);
 341         }
 342         return;
 343 }
 344
 345 /* Jack the reaper */
 346 void
 347 reaper(int sig)
 348 {
 349         int st;
 350
 351         while (wait3(&st, WNOHANG, NULL) > 0)
 352                 children--;
 353 }
 354
 355 void
 356 terminate(int sig)
 357 {
 358         struct _dom_binding *ypdb;
 359         char path[MAXPATHLEN];
 360
 361         if (ppid != getpid())
 362                 exit(0);
 363
 364         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 365                 close(ypdb->dom_lockfd);
 366                 if (ypdb->dom_broadcast_pid)
 367                         kill(ypdb->dom_broadcast_pid, SIGINT);
 368                 sprintf(path, "%s/%s.%ld", BINDINGDIR,
 369                         ypdb->dom_domain, ypdb->dom_vers);
 370                 unlink(path);
 371         }
 372         close(yplockfd);
 373         unlink(YPBINDLOCK);
 374         pmap_unset(YPBINDPROG, YPBINDVERS);
 375         exit(0);
 376 }
 377
 378 int
 379 main(int argc, char *argv[])
 380 {
 381         struct timeval tv;
 382         int i;
 383         DIR *dird;
 384         struct dirent *dirp;
 385         struct _dom_binding *ypdb, *next;
 386
 387         /* Check that another ypbind isn't already running. */
 388         if ((yplockfd = (open(YPBINDLOCK, O_RDONLY|O_CREAT, 0444))) == -1)
 389                 err(1, "%s", YPBINDLOCK);
 390
 391         if (flock(yplockfd, LOCK_EX|LOCK_NB) == -1 && errno == EWOULDBLOCK)
 392                 errx(1, "another ypbind is already running. Aborting");
 393
 394         /* XXX domainname will be overriden if we use restricted mode */
 395         yp_get_default_domain(&domain_name);
 396         if (domain_name[0] == '\0')
 397                 errx(1, "domainname not set. Aborting");
 398
 399         for (i = 1; i<argc; i++) {
 400                 if (strcmp("-ypset", argv[i]) == 0)
 401                         ypsetmode = YPSET_ALL;
 402                 else if (strcmp("-ypsetme", argv[i]) == 0)
 403                         ypsetmode = YPSET_LOCAL;
 404                 else if (strcmp("-s", argv[i]) == 0)
 405                         ypsecuremode++;
 406                 else if (strcmp("-S", argv[i]) == 0 && argc > i)
 407                         yp_restricted_mode(argv[++i]);
 408                 else if (strcmp("-m", argv[i]) == 0)
 409                         yp_manycast++;
 410                 else
 411                         errx(1, "unknown option: %s", argv[i]);
 412         }
 413
 414         /* blow away everything in BINDINGDIR (if it exists) */
 415
 416         if ((dird = opendir(BINDINGDIR)) != NULL) {
 417                 char path[MAXPATHLEN];
 418                 while ((dirp = readdir(dird)) != NULL)
 419                         if (strcmp(dirp->d_name, ".") &&
 420                             strcmp(dirp->d_name, "..")) {
 421                                 sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name);
 422                                 unlink(path);
 423                         }
 424                 closedir(dird);
 425         }
 426
 427 #ifdef DAEMON
 428         if (daemon(0,0))
 429                 err(1, "fork");
 430 #endif
 431
 432         pmap_unset(YPBINDPROG, YPBINDVERS);
 433
 434         udptransp = svcudp_create(RPC_ANYSOCK);
 435         if (udptransp == NULL)
 436                 errx(1, "cannot create udp service");
 437         if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 438             IPPROTO_UDP))
 439                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)");
 440
 441         tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0);
 442         if (tcptransp == NULL)
 443                 errx(1, "cannot create tcp service");
 444
 445         if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 446             IPPROTO_TCP))
 447                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)");
 448
 449         /* build initial domain binding, make it "unsuccessful" */
 450         ypbindlist = (struct _dom_binding *)malloc(sizeof *ypbindlist);
 451         if (ypbindlist == NULL)
 452                 errx(1, "malloc");
 453         bzero(ypbindlist, sizeof *ypbindlist);
 454         strncpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain);
 455         ypbindlist->dom_vers = YPVERS;
 456         ypbindlist->dom_alive = 0;
 457         ypbindlist->dom_lockfd = -1;
 458         ypbindlist->dom_default = 1;
 459         domains++;
 460
 461         signal(SIGCHLD, reaper);
 462         signal(SIGTERM, terminate);
 463
 464         ppid = getpid(); /* Remember who we are. */
 465
 466         openlog(argv[0], LOG_PID, LOG_DAEMON);
 467
 468         /* Kick off the default domain */
 469         broadcast(ypbindlist);
 470
 471         while (1) {
 472                 fdsr = svc_fdset;
 473
 474                 tv.tv_sec = 60;
 475                 tv.tv_usec = 0;
 476
 477                 switch (select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) {
 478                 case 0:
 479                         checkwork();
 480                         break;
 481                 case -1:
 482                         if (errno != EINTR)
 483                                 syslog(LOG_WARNING, "select: %m");
 484                         break;
 485                 default:
 486                         for (ypdb = ypbindlist; ypdb; ypdb = next) {
 487                                 next = ypdb->dom_pnext;
 488                                 if (READFD > 0 && FD_ISSET(READFD, &fdsr)) {
 489                                         handle_children(ypdb);
 490                                         if (children == (MAX_CHILDREN - 1))
 491                                                 checkwork();
 492                                 }
 493                         }
 494                         svc_getreqset(&fdsr);
 495                         break;
 496                 }
 497         }
 498
 499         /* NOTREACHED */
 500         exit(1);
 501 }
 502
 503 void
 504 checkwork(void)
 505 {
 506         struct _dom_binding *ypdb;
 507
 508         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
 509                 ping(ypdb);
 510 }
 511
 512 /* The clnt_broadcast() callback mechanism sucks. */
 513
 514 /*
 515  * Receive results from broadcaster. Don't worry about passing
 516  * bogus info to rpc_received() -- it can handle it. Note that we
 517  * must be sure to invalidate the dom_pipe_fds descriptors here:
 518  * since descriptors can be re-used, we have to make sure we
 519  * don't mistake one of the RPC descriptors for one of the pipes.
 520  * What's weird is that forgetting to invalidate the pipe descriptors
 521  * doesn't always result in an error (otherwise I would have caught
 522  * the mistake much sooner), even though logically it should.
 523  */
 524 void
 525 handle_children(struct _dom_binding *ypdb)
 526 {
 527         char buf[YPMAXDOMAIN + 1];
 528         struct sockaddr_in addr;
 529         int d = 0, a = 0;
 530         struct _dom_binding *y, *prev = NULL;
 531         char path[MAXPATHLEN];
 532
 533         if ((d = read(READFD, &buf, sizeof(buf))) <= 0)
 534                 syslog(LOG_WARNING, "could not read from child: %m");
 535
 536         if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0)
 537                 syslog(LOG_WARNING, "could not read from child: %m");
 538
 539         close(READFD);
 540         FD_CLR(READFD, &fdsr);
 541         FD_CLR(READFD, &svc_fdset);
 542         READFD = WRITEFD = -1;
 543         if (d > 0 && a > 0)
 544                 rpc_received(buf, &addr, 0);
 545         else {
 546                 for (y = ypbindlist; y; y = y->dom_pnext) {
 547                         if (y == ypdb)
 548                                 break;
 549                         prev = y;
 550                 }
 551                 switch (ypdb->dom_default) {
 552                 case 0:
 553                         if (prev == NULL)
 554                                 ypbindlist = y->dom_pnext;
 555                         else
 556                                 prev->dom_pnext = y->dom_pnext;
 557                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 558                                 ypdb->dom_domain, YPVERS);
 559                         close(ypdb->dom_lockfd);
 560                         unlink(path);
 561                         free(ypdb);
 562                         domains--;
 563                         return;
 564                 case 1:
 565                         ypdb->dom_broadcast_pid = 0;
 566                         ypdb->dom_alive = 0;
 567                         broadcast(ypdb);
 568                         return;
 569                 default:
 570                         break;
 571                 }
 572         }
 573
 574         return;
 575 }
 576
 577 /*
 578  * Send our dying words back to our parent before we perish.
 579  */
 580 int
 581 tell_parent(char *dom, struct sockaddr_in *addr)
 582 {
 583         char buf[YPMAXDOMAIN + 1];
 584         struct timeval timeout;
 585         fd_set fds;
 586
 587         timeout.tv_sec = 5;
 588         timeout.tv_usec = 0;
 589
 590         sprintf(buf, "%s", broad_domain->dom_domain);
 591         if (write(BROADFD, &buf, sizeof(buf)) < 0)
 592                 return(1);
 593
 594         /*
 595          * Stay in sync with parent: wait for it to read our first
 596          * message before sending the second.
 597          */
 598
 599         FD_ZERO(&fds);
 600         FD_SET(BROADFD, &fds);
 601         if (select(FD_SETSIZE, NULL, &fds, NULL, &timeout) == -1)
 602                 return(1);
 603         if (FD_ISSET(BROADFD, &fds)) {
 604                 if (write(BROADFD, addr, sizeof(struct sockaddr_in)) < 0)
 605                         return(1);
 606         } else {
 607                 return(1);
 608         }
 609
 610         close(BROADFD);
 611         return (0);
 612 }
 613
 614 bool_t broadcast_result(out, addr)
 615 bool_t *out;
 616 struct sockaddr_in *addr;
 617 {
 618         if (retries >= MAX_RETRIES) {
 619                 bzero(addr, sizeof(struct sockaddr_in));
 620                 if (tell_parent(broad_domain->dom_domain, addr))
 621                         syslog(LOG_WARNING, "lost connection to parent");
 622                 return (TRUE);
 623         }
 624
 625         if (yp_restricted && verify(addr->sin_addr)) {
 626                 retries++;
 627                 syslog(LOG_NOTICE, "NIS server at %s not in restricted mode access list -- rejecting.\n",inet_ntoa(addr->sin_addr));
 628                 return (FALSE);
 629         } else {
 630                 if (tell_parent(broad_domain->dom_domain, addr))
 631                         syslog(LOG_WARNING, "lost connection to parent");
 632                 return (TRUE);
 633         }
 634 }
 635
 636 /*
 637  * The right way to send RPC broadcasts.
 638  * Use the clnt_broadcast() RPC service. Unfortunately, clnt_broadcast()
 639  * blocks while waiting for replies, so we have to fork off separate
 640  * broadcaster processes that do the waiting and then transmit their
 641  * results back to the parent for processing. We also have to remember
 642  * to save the name of the domain we're trying to bind in a global
 643  * variable since clnt_broadcast() provides no way to pass things to
 644  * the 'eachresult' callback function.
 645  */
 646 void
 647 broadcast(struct _dom_binding *ypdb)
 648 {
 649         bool_t out = FALSE;
 650         enum clnt_stat stat;
 651
 652         if (children >= MAX_CHILDREN || ypdb->dom_broadcast_pid)
 653                 return;
 654
 655         if (pipe(ypdb->dom_pipe_fds) < 0) {
 656                 syslog(LOG_WARNING, "pipe: %m");
 657                 return;
 658         }
 659
 660         if (ypdb->dom_vers == -1 && (long)ypdb->dom_server_addr.sin_addr.s_addr)
 661                 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding",
 662                 inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain);
 663
 664         broad_domain = ypdb;
 665         flock(ypdb->dom_lockfd, LOCK_UN);
 666
 667         switch ((ypdb->dom_broadcast_pid = fork())) {
 668         case 0:
 669                 close(READFD);
 670                 signal(SIGCHLD, SIG_DFL);
 671                 signal(SIGTERM, SIG_DFL);
 672                 break;
 673         case -1:
 674                 syslog(LOG_WARNING, "fork: %m");
 675                 close(READFD);
 676                 close(WRITEFD);
 677                 return;
 678         default:
 679                 close(WRITEFD);
 680                 FD_SET(READFD, &svc_fdset);
 681                 children++;
 682                 return;
 683         }
 684
 685         /* Release all locks before doing anything else. */
 686         while (ypbindlist) {
 687                 close(ypbindlist->dom_lockfd);
 688                 ypbindlist = ypbindlist->dom_pnext;
 689         }
 690         close(yplockfd);
 691
 692         /*
 693          * Special 'many-cast' behavior. If we're in restricted mode,
 694          * we have a list of possible server addresses to try. What
 695          * we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK
 696          * procedure and time the replies. Whoever replies fastest
 697          * gets to be our server. Note that this is not a broadcast
 698          * operation: we transmit uni-cast datagrams only.
 699          */
 700         if (yp_restricted && yp_manycast) {
 701                 short                   port;
 702                 int                     i;
 703                 struct sockaddr_in      sin;
 704
 705                 i = __yp_ping(restricted_addrs, yp_restricted,
 706                                 ypdb->dom_domain, &port);
 707                 if (i == -1) {
 708                         bzero(&ypdb->dom_server_addr,
 709                             sizeof(struct sockaddr_in));
 710                         if (tell_parent(ypdb->dom_domain,
 711                                 &ypdb->dom_server_addr))
 712                         syslog(LOG_WARNING, "lost connection to parent");
 713                 } else {
 714                         bzero(&sin, sizeof(struct sockaddr_in));
 715                         bcopy(&restricted_addrs[i],
 716                             &sin.sin_addr, sizeof(struct in_addr));
 717                         sin.sin_family = AF_INET;
 718                         sin.sin_port = port;
 719                         if (tell_parent(broad_domain->dom_domain, &sin))
 720                                 syslog(LOG_WARNING,
 721                                         "lost connection to parent");
 722                 }
 723                 _exit(0);
 724         }
 725
 726         retries = 0;
 727
 728         {
 729                 char *ptr;
 730
 731                 ptr = ypdb->dom_domain;
 732                 stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK,
 733                         (xdrproc_t)xdr_domainname, &ptr,
 734                         (xdrproc_t)xdr_bool, &out,
 735                         (resultproc_t)broadcast_result);
 736         }
 737
 738         if (stat != RPC_SUCCESS) {
 739                 bzero(&ypdb->dom_server_addr,
 740                     sizeof(struct sockaddr_in));
 741                 if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr))
 742                         syslog(LOG_WARNING, "lost connection to parent");
 743         }
 744
 745         _exit(0);
 746 }
 747
 748 /*
 749  * The right way to check if a server is alive.
 750  * Attempt to get a client handle pointing to the server and send a
 751  * YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE,
 752  * we invalidate this binding entry and send out a broadcast to try to
 753  * establish a new binding. Note that we treat non-default domains
 754  * specially: once bound, we keep tabs on our server, but if it
 755  * goes away and fails to respond after one round of broadcasting, we
 756  * abandon it until a client specifically references it again. We make
 757  * every effort to keep our default domain bound, however, since we
 758  * need it to keep the system on its feet.
 759  */
 760 int
 761 ping(struct _dom_binding *ypdb)
 762 {
 763         bool_t out;
 764         struct timeval interval, timeout;
 765         enum clnt_stat stat;
 766         int rpcsock = RPC_ANYSOCK;
 767         CLIENT *client_handle;
 768
 769         interval.tv_sec = FAIL_THRESHOLD;
 770         interval.tv_usec = 0;
 771         timeout.tv_sec = FAIL_THRESHOLD;
 772         timeout.tv_usec = 0;
 773
 774         if (ypdb->dom_broadcast_pid)
 775                 return(1);
 776
 777         if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr,
 778                 YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE,
 779                 RPCSMALLMSGSIZE)) == (CLIENT *)NULL) {
 780                 /* Can't get a handle: we're dead. */
 781                 ypdb->dom_alive = 0;
 782                 ypdb->dom_vers = -1;
 783                 broadcast(ypdb);
 784                 return(1);
 785         }
 786
 787         {
 788                 char *ptr;
 789
 790                 ptr = ypdb->dom_domain;
 791
 792                 stat = clnt_call(client_handle, YPPROC_DOMAIN,
 793                     (xdrproc_t)xdr_domainname, &ptr,
 794                     (xdrproc_t)xdr_bool, &out, timeout);
 795                 if (stat != RPC_SUCCESS || out == FALSE) {
 796                         ypdb->dom_alive = 0;
 797                         ypdb->dom_vers = -1;
 798                         clnt_destroy(client_handle);
 799                         broadcast(ypdb);
 800                         return(1);
 801                 }
 802         }
 803
 804         clnt_destroy(client_handle);
 805         return(0);
 806 }
 807
 808 void
 809 rpc_received(char *dom, struct sockaddr_in *raddrp, int force)
 810 {
 811         struct _dom_binding *ypdb, *prev = NULL;
 812         struct iovec iov[2];
 813         struct ypbind_resp ybr;
 814         char path[MAXPATHLEN];
 815         int fd;
 816
 817         /*printf("returned from %s/%d about %s\n", inet_ntoa(raddrp->sin_addr),
 818                ntohs(raddrp->sin_port), dom);*/
 819
 820         if (dom == NULL)
 821                 return;
 822
 823         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 824                 if (strcmp(ypdb->dom_domain, dom) == 0)
 825                         break;
 826                 prev = ypdb;
 827         }
 828
 829         if (ypdb && force) {
 830                 if (ypdb->dom_broadcast_pid) {
 831                         kill(ypdb->dom_broadcast_pid, SIGINT);
 832                         close(READFD);
 833                         FD_CLR(READFD, &fdsr);
 834                         FD_CLR(READFD, &svc_fdset);
 835                         READFD = WRITEFD = -1;
 836                 }
 837         }
 838
 839         /* if in secure mode, check originating port number */
 840         if ((ypsecuremode && (ntohs(raddrp->sin_port) >= IPPORT_RESERVED))) {
 841             syslog(LOG_WARNING, "Rejected NIS server on [%s/%d] for domain %s.",
 842                    inet_ntoa(raddrp->sin_addr), ntohs(raddrp->sin_port),
 843                    dom);
 844             if (ypdb != NULL) {
 845                 ypdb->dom_broadcast_pid = 0;
 846                 ypdb->dom_alive = 0;
 847             }
 848             return;
 849         }
 850
 851         if (raddrp->sin_addr.s_addr == (long)0) {
 852                 switch (ypdb->dom_default) {
 853                 case 0:
 854                         if (prev == NULL)
 855                                 ypbindlist = ypdb->dom_pnext;
 856                         else
 857                                 prev->dom_pnext = ypdb->dom_pnext;
 858                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 859                                 ypdb->dom_domain, YPVERS);
 860                         close(ypdb->dom_lockfd);
 861                         unlink(path);
 862                         free(ypdb);
 863                         domains--;
 864                         return;
 865                 case 1:
 866                         ypdb->dom_broadcast_pid = 0;
 867                         ypdb->dom_alive = 0;
 868                         broadcast(ypdb);
 869                         return;
 870                 default:
 871                         break;
 872                 }
 873         }
 874
 875         if (ypdb == NULL) {
 876                 if (force == 0)
 877                         return;
 878                 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb);
 879                 if (ypdb == NULL) {
 880                         syslog(LOG_WARNING, "malloc: %m");
 881                         return;
 882                 }
 883                 bzero(ypdb, sizeof *ypdb);
 884                 strncpy(ypdb->dom_domain, dom, sizeof ypdb->dom_domain);
 885                 ypdb->dom_lockfd = -1;
 886                 ypdb->dom_default = 0;
 887                 ypdb->dom_pnext = ypbindlist;
 888                 ypbindlist = ypdb;
 889         }
 890
 891         /* We've recovered from a crash: inform the world. */
 892         if (ypdb->dom_vers == -1 && ypdb->dom_server_addr.sin_addr.s_addr)
 893                 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" OK",
 894                 inet_ntoa(raddrp->sin_addr), ypdb->dom_domain);
 895
 896         bcopy(raddrp, &ypdb->dom_server_addr,
 897                 sizeof ypdb->dom_server_addr);
 898
 899         ypdb->dom_vers = YPVERS;
 900         ypdb->dom_alive = 1;
 901         ypdb->dom_broadcast_pid = 0;
 902
 903         if (ypdb->dom_lockfd != -1)
 904                 close(ypdb->dom_lockfd);
 905
 906         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 907                 ypdb->dom_domain, ypdb->dom_vers);
 908 #ifdef O_SHLOCK
 909         if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) {
 910                 (void)mkdir(BINDINGDIR, 0755);
 911                 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1)
 912                         return;
 913         }
 914 #else
 915         if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) {
 916                 (void)mkdir(BINDINGDIR, 0755);
 917                 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1)
 918                         return;
 919         }
 920         flock(fd, LOCK_SH);
 921 #endif
 922
 923         /*
 924          * ok, if BINDINGDIR exists, and we can create the binding file,
 925          * then write to it..
 926          */
 927         ypdb->dom_lockfd = fd;
 928
 929         iov[0].iov_base = (char *)&(udptransp->xp_port);
 930         iov[0].iov_len = sizeof udptransp->xp_port;
 931         iov[1].iov_base = (char *)&ybr;
 932         iov[1].iov_len = sizeof ybr;
 933
 934         bzero(&ybr, sizeof ybr);
 935         ybr.ypbind_status = YPBIND_SUCC_VAL;
 936         *(u_int32_t *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = raddrp->sin_addr.s_addr;
 937         *(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = raddrp->sin_port;
 938
 939         if (writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) {
 940                 syslog(LOG_WARNING, "write: %m");
 941                 close(ypdb->dom_lockfd);
 942                 ypdb->dom_lockfd = -1;
 943                 return;
 944         }
 945 }
 946
 947 /*
 948  * Check address against list of allowed servers. Return 0 if okay,
 949  * 1 if not matched.
 950  */
 951 int
 952 verify(struct in_addr addr)
 953 {
 954         int i;
 955
 956         for (i = 0; i < RESTRICTED_SERVERS; i++)
 957                 if (!bcmp(&addr, &restricted_addrs[i], sizeof(struct in_addr)))
 958                         return(0);
 959
 960         return(1);
 961 }
 962
 963 /*
 964  * Try to set restricted mode. We default to normal mode if we can't
 965  * resolve the specified hostnames.
 966  */
 967 void
 968 yp_restricted_mode(char *args)
 969 {
 970         struct hostent *h;
 971         int i = 0;
 972         char *s;
 973
 974         /* Find the restricted domain. */
 975         if ((s = strsep(&args, ",")) == NULL)
 976                 return;
 977         domain_name = s;
 978
 979         /* Get the addresses of the servers. */
 980         while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) {
 981                 if ((h = gethostbyname(s)) == NULL)
 982                         return;
 983                 bcopy (h->h_addr_list[0], &restricted_addrs[i],
 984                     sizeof(struct in_addr));
 985                 i++;
 986         }
 987
 988         /* ypset and ypsetme not allowed with restricted mode */
 989         ypsetmode = YPSET_NO;
 990
 991         yp_restricted = i;
 992         return;
 993 }