usr.sbin/ypbind/ypbind.c

   1 /*
   2  * Copyright (c) 1992/3 Theo de Raadt <deraadt@fsa.ca>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote
  14  *    products derived from this software without specific prior written
  15  *    permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
  18  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD: src/usr.sbin/ypbind/ypbind.c,v 1.30.2.2 2002/02/15 00:46:59 des Exp $
  30  * $DragonFly: src/usr.sbin/ypbind/ypbind.c,v 1.6 2005/11/24 22:23:02 swildner Exp $
  31  */
  32
  33 #include <sys/param.h>
  34 #include <sys/types.h>
  35 #include <sys/wait.h>
  36 #include <sys/ioctl.h>
  37 #include <sys/signal.h>
  38 #include <sys/socket.h>
  39 #include <sys/file.h>
  40 #include <sys/fcntl.h>
  41 #include <sys/stat.h>
  42 #include <sys/uio.h>
  43 #include <ctype.h>
  44 #include <dirent.h>
  45 #include <err.h>
  46 #include <errno.h>
  47 #include <netdb.h>
  48 #include <signal.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include <syslog.h>
  53 #include <unistd.h>
  54 #include <rpc/rpc.h>
  55 #include <rpc/xdr.h>
  56 #include <net/if.h>
  57 #include <netinet/in.h>
  58 #include <arpa/inet.h>
  59 #include <rpc/pmap_clnt.h>
  60 #include <rpc/pmap_prot.h>
  61 #include <rpc/pmap_rmt.h>
  62 #include <rpc/rpc_com.h>
  63 #include <rpcsvc/yp.h>
  64 struct dom_binding{};
  65 #include <rpcsvc/ypclnt.h>
  66 #include "yp_ping.h"
  67
  68 #ifndef BINDINGDIR
  69 #define BINDINGDIR "/var/yp/binding"
  70 #endif
  71
  72 #ifndef YPBINDLOCK
  73 #define YPBINDLOCK "/var/run/ypbind.lock"
  74 #endif
  75
  76 struct _dom_binding {
  77         struct _dom_binding *dom_pnext;
  78         char dom_domain[YPMAXDOMAIN + 1];
  79         struct sockaddr_in dom_server_addr;
  80         long int dom_vers;
  81         int dom_lockfd;
  82         int dom_alive;
  83         int dom_broadcast_pid;
  84         int dom_pipe_fds[2];
  85         int dom_default;
  86 };
  87
  88 #define READFD ypdb->dom_pipe_fds[0]
  89 #define WRITEFD ypdb->dom_pipe_fds[1]
  90 #define BROADFD broad_domain->dom_pipe_fds[1]
  91
  92 extern bool_t xdr_domainname(), xdr_ypbind_resp();
  93 extern bool_t xdr_ypreq_key(), xdr_ypresp_val();
  94 extern bool_t xdr_ypbind_setdom();
  95
  96 void    checkwork(void);
  97 void    *ypbindproc_null_2_yp(SVCXPRT *, void *, CLIENT *);
  98 void    *ypbindproc_setdom_2_yp(SVCXPRT *, struct ypbind_setdom *, CLIENT *);
  99 void    rpc_received(char *, struct sockaddr_in *, int);
 100 void    broadcast(struct _dom_binding *);
 101 int     ping(struct _dom_binding *);
 102 int     tell_parent(char *, struct sockaddr_in *);
 103 void    handle_children(struct _dom_binding *);
 104 void    reaper(int);
 105 void    terminate(int);
 106 void    yp_restricted_mode(char *);
 107 int     verify(struct in_addr);
 108
 109 char *domain_name;
 110 struct _dom_binding *ypbindlist;
 111 static struct _dom_binding *broad_domain;
 112
 113 #define YPSET_NO        0
 114 #define YPSET_LOCAL     1
 115 #define YPSET_ALL       2
 116 int ypsetmode = YPSET_NO;
 117 int ypsecuremode = 0;
 118 int ppid;
 119
 120 /*
 121  * Special restricted mode variables: when in restricted mode, only the
 122  * specified restricted_domain will be bound, and only the servers listed
 123  * in restricted_addrs will be used for binding.
 124  */
 125 #define RESTRICTED_SERVERS 10
 126 int yp_restricted = 0;
 127 int yp_manycast = 0;
 128 struct in_addr restricted_addrs[RESTRICTED_SERVERS];
 129
 130 /* No more than MAX_CHILDREN child broadcasters at a time. */
 131 #ifndef MAX_CHILDREN
 132 #define MAX_CHILDREN 5
 133 #endif
 134 /* No more than MAX_DOMAINS simultaneous domains */
 135 #ifndef MAX_DOMAINS
 136 #define MAX_DOMAINS 200
 137 #endif
 138 /* RPC timeout value */
 139 #ifndef FAIL_THRESHOLD
 140 #define FAIL_THRESHOLD 20
 141 #endif
 142
 143 /* Number of times to fish for a response froma particular set of hosts */
 144 #ifndef MAX_RETRIES
 145 #define MAX_RETRIES 30
 146 #endif
 147
 148 int retries = 0;
 149 int children = 0;
 150 int domains = 0;
 151 int yplockfd;
 152 fd_set fdsr;
 153
 154 SVCXPRT *udptransp, *tcptransp;
 155
 156 void *
 157 ypbindproc_null_2_yp(SVCXPRT *transp, void *argp, CLIENT *clnt)
 158 {
 159         static char res;
 160
 161         bzero((char *)&res, sizeof(res));
 162         return (void *)&res;
 163 }
 164
 165 struct ypbind_resp *
 166 ypbindproc_domain_2_yp(SVCXPRT *transp, domainname *argp, CLIENT *clnt)
 167 {
 168         static struct ypbind_resp res;
 169         struct _dom_binding *ypdb;
 170         char path[MAXPATHLEN];
 171
 172         bzero((char *)&res, sizeof res);
 173         res.ypbind_status = YPBIND_FAIL_VAL;
 174         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_NOSERV;
 175
 176         if (strchr(*argp, '/')) {
 177                 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
 178 rejecting.", *argp);
 179                 return(&res);
 180         }
 181
 182         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 183                 if (strcmp(ypdb->dom_domain, *argp) == 0)
 184                         break;
 185                 }
 186
 187         if (ypdb == NULL) {
 188                 if (yp_restricted) {
 189                         syslog(LOG_NOTICE, "Running in restricted mode -- request to bind domain \"%s\" rejected.\n", *argp);
 190                         return (&res);
 191                 }
 192
 193                 if (domains >= MAX_DOMAINS) {
 194                         syslog(LOG_WARNING, "domain limit (%d) exceeded",
 195                                                         MAX_DOMAINS);
 196                         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
 197                         return (&res);
 198                 }
 199                 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb);
 200                 if (ypdb == NULL) {
 201                         syslog(LOG_WARNING, "malloc: %m");
 202                         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
 203                         return (&res);
 204                 }
 205                 bzero((char *)ypdb, sizeof *ypdb);
 206                 strncpy(ypdb->dom_domain, *argp, sizeof ypdb->dom_domain);
 207                 ypdb->dom_vers = YPVERS;
 208                 ypdb->dom_alive = 0;
 209                 ypdb->dom_default = 0;
 210                 ypdb->dom_lockfd = -1;
 211                 sprintf(path, "%s/%s.%ld", BINDINGDIR,
 212                                         ypdb->dom_domain, ypdb->dom_vers);
 213                 unlink(path);
 214                 ypdb->dom_pnext = ypbindlist;
 215                 ypbindlist = ypdb;
 216                 domains++;
 217         }
 218
 219         if (ping(ypdb)) {
 220                 return (&res);
 221         }
 222
 223         res.ypbind_status = YPBIND_SUCC_VAL;
 224         res.ypbind_resp_u.ypbind_error = 0; /* Success */
 225         *(u_int32_t *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr =
 226                 ypdb->dom_server_addr.sin_addr.s_addr;
 227         *(u_short *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port =
 228                 ypdb->dom_server_addr.sin_port;
 229         /*printf("domain %s at %s/%d\n", ypdb->dom_domain,
 230                 inet_ntoa(ypdb->dom_server_addr.sin_addr),
 231                 ntohs(ypdb->dom_server_addr.sin_port));*/
 232         return (&res);
 233 }
 234
 235 void *
 236 ypbindproc_setdom_2_yp(SVCXPRT *transp, ypbind_setdom *argp, CLIENT *clnt)
 237 {
 238         struct sockaddr_in *fromsin, bindsin;
 239         static char *result = NULL;
 240
 241         if (strchr(argp->ypsetdom_domain, '/')) {
 242                 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
 243 rejecting.", argp->ypsetdom_domain);
 244                 return(NULL);
 245         }
 246         fromsin = svc_getcaller(transp);
 247
 248         switch (ypsetmode) {
 249         case YPSET_LOCAL:
 250                 if (fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) {
 251                         svcerr_noprog(transp);
 252                         return(NULL);
 253                 }
 254                 break;
 255         case YPSET_ALL:
 256                 break;
 257         case YPSET_NO:
 258         default:
 259                 svcerr_noprog(transp);
 260                 return(NULL);
 261         }
 262
 263         if (ntohs(fromsin->sin_port) >= IPPORT_RESERVED) {
 264                 svcerr_noprog(transp);
 265                 return(NULL);
 266         }
 267
 268         if (argp->ypsetdom_vers != YPVERS) {
 269                 svcerr_noprog(transp);
 270                 return(NULL);
 271         }
 272
 273         bzero((char *)&bindsin, sizeof bindsin);
 274         bindsin.sin_family = AF_INET;
 275         bindsin.sin_addr.s_addr = *(u_int32_t *)argp->ypsetdom_binding.ypbind_binding_addr;
 276         bindsin.sin_port = *(u_short *)argp->ypsetdom_binding.ypbind_binding_port;
 277         rpc_received(argp->ypsetdom_domain, &bindsin, 1);
 278
 279         return((void *) &result);
 280 }
 281
 282 static void
 283 ypbindprog_2(struct svc_req *rqstp, SVCXPRT *transp)
 284 {
 285         union {
 286                 domainname ypbindproc_domain_2_arg;
 287                 struct ypbind_setdom ypbindproc_setdom_2_arg;
 288         } argument;
 289         struct authunix_parms *creds;
 290         char *result;
 291         bool_t (*xdr_argument)(), (*xdr_result)();
 292         char *(*local)();
 293
 294         switch (rqstp->rq_proc) {
 295         case YPBINDPROC_NULL:
 296                 xdr_argument = xdr_void;
 297                 xdr_result = xdr_void;
 298                 local = (char *(*)()) ypbindproc_null_2_yp;
 299                 break;
 300
 301         case YPBINDPROC_DOMAIN:
 302                 xdr_argument = xdr_domainname;
 303                 xdr_result = xdr_ypbind_resp;
 304                 local = (char *(*)()) ypbindproc_domain_2_yp;
 305                 break;
 306
 307         case YPBINDPROC_SETDOM:
 308                 switch (rqstp->rq_cred.oa_flavor) {
 309                 case AUTH_UNIX:
 310                         creds = (struct authunix_parms *)rqstp->rq_clntcred;
 311                         if (creds->aup_uid != 0) {
 312                                 svcerr_auth(transp, AUTH_BADCRED);
 313                                 return;
 314                         }
 315                         break;
 316                 default:
 317                         svcerr_auth(transp, AUTH_TOOWEAK);
 318                         return;
 319                 }
 320
 321                 xdr_argument = xdr_ypbind_setdom;
 322                 xdr_result = xdr_void;
 323                 local = (char *(*)()) ypbindproc_setdom_2_yp;
 324                 break;
 325
 326         default:
 327                 svcerr_noproc(transp);
 328                 return;
 329         }
 330         bzero((char *)&argument, sizeof(argument));
 331         if (!svc_getargs(transp, xdr_argument, (caddr_t)&argument)) {
 332                 svcerr_decode(transp);
 333                 return;
 334         }
 335         result = (*local)(transp, &argument, rqstp);
 336         if (result != NULL && !svc_sendreply(transp, xdr_result, result)) {
 337                 svcerr_systemerr(transp);
 338         }
 339         return;
 340 }
 341
 342 /* Jack the reaper */
 343 void
 344 reaper(int sig)
 345 {
 346         int st;
 347
 348         while (wait3(&st, WNOHANG, NULL) > 0)
 349                 children--;
 350 }
 351
 352 void
 353 terminate(int sig)
 354 {
 355         struct _dom_binding *ypdb;
 356         char path[MAXPATHLEN];
 357
 358         if (ppid != getpid())
 359                 exit(0);
 360
 361         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 362                 close(ypdb->dom_lockfd);
 363                 if (ypdb->dom_broadcast_pid)
 364                         kill(ypdb->dom_broadcast_pid, SIGINT);
 365                 sprintf(path, "%s/%s.%ld", BINDINGDIR,
 366                         ypdb->dom_domain, ypdb->dom_vers);
 367                 unlink(path);
 368         }
 369         close(yplockfd);
 370         unlink(YPBINDLOCK);
 371         pmap_unset(YPBINDPROG, YPBINDVERS);
 372         exit(0);
 373 }
 374
 375 int
 376 main(int argc, char **argv)
 377 {
 378         struct timeval tv;
 379         int i;
 380         DIR *dird;
 381         struct dirent *dirp;
 382         struct _dom_binding *ypdb, *next;
 383
 384         /* Check that another ypbind isn't already running. */
 385         if ((yplockfd = (open(YPBINDLOCK, O_RDONLY|O_CREAT, 0444))) == -1)
 386                 err(1, "%s", YPBINDLOCK);
 387
 388         if (flock(yplockfd, LOCK_EX|LOCK_NB) == -1 && errno == EWOULDBLOCK)
 389                 errx(1, "another ypbind is already running. Aborting");
 390
 391         /* XXX domainname will be overriden if we use restricted mode */
 392         yp_get_default_domain(&domain_name);
 393         if (domain_name[0] == '\0')
 394                 errx(1, "domainname not set. Aborting");
 395
 396         for (i = 1; i<argc; i++) {
 397                 if (strcmp("-ypset", argv[i]) == 0)
 398                         ypsetmode = YPSET_ALL;
 399                 else if (strcmp("-ypsetme", argv[i]) == 0)
 400                         ypsetmode = YPSET_LOCAL;
 401                 else if (strcmp("-s", argv[i]) == 0)
 402                         ypsecuremode++;
 403                 else if (strcmp("-S", argv[i]) == 0 && argc > i)
 404                         yp_restricted_mode(argv[i+1]);
 405                 else if (strcmp("-m", argv[i]) == 0)
 406                         yp_manycast++;
 407         }
 408
 409         /* blow away everything in BINDINGDIR (if it exists) */
 410
 411         if ((dird = opendir(BINDINGDIR)) != NULL) {
 412                 char path[MAXPATHLEN];
 413                 while ((dirp = readdir(dird)) != NULL)
 414                         if (strcmp(dirp->d_name, ".") &&
 415                             strcmp(dirp->d_name, "..")) {
 416                                 sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name);
 417                                 unlink(path);
 418                         }
 419                 closedir(dird);
 420         }
 421
 422 #ifdef DAEMON
 423         if (daemon(0,0))
 424                 err(1, "fork");
 425 #endif
 426
 427         pmap_unset(YPBINDPROG, YPBINDVERS);
 428
 429         udptransp = svcudp_create(RPC_ANYSOCK);
 430         if (udptransp == NULL)
 431                 errx(1, "cannot create udp service");
 432         if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 433             IPPROTO_UDP))
 434                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)");
 435
 436         tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0);
 437         if (tcptransp == NULL)
 438                 errx(1, "cannot create tcp service");
 439
 440         if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 441             IPPROTO_TCP))
 442                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)");
 443
 444         /* build initial domain binding, make it "unsuccessful" */
 445         ypbindlist = (struct _dom_binding *)malloc(sizeof *ypbindlist);
 446         if (ypbindlist == NULL)
 447                 errx(1, "malloc");
 448         bzero((char *)ypbindlist, sizeof *ypbindlist);
 449         strncpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain);
 450         ypbindlist->dom_vers = YPVERS;
 451         ypbindlist->dom_alive = 0;
 452         ypbindlist->dom_lockfd = -1;
 453         ypbindlist->dom_default = 1;
 454         domains++;
 455
 456         signal(SIGCHLD, reaper);
 457         signal(SIGTERM, terminate);
 458
 459         ppid = getpid(); /* Remember who we are. */
 460
 461         openlog(argv[0], LOG_PID, LOG_DAEMON);
 462
 463         /* Kick off the default domain */
 464         broadcast(ypbindlist);
 465
 466         while (1) {
 467                 fdsr = svc_fdset;
 468
 469                 tv.tv_sec = 60;
 470                 tv.tv_usec = 0;
 471
 472                 switch (select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) {
 473                 case 0:
 474                         checkwork();
 475                         break;
 476                 case -1:
 477                         if (errno != EINTR)
 478                                 syslog(LOG_WARNING, "select: %m");
 479                         break;
 480                 default:
 481                         for (ypdb = ypbindlist; ypdb; ypdb = next) {
 482                                 next = ypdb->dom_pnext;
 483                                 if (READFD > 0 && FD_ISSET(READFD, &fdsr)) {
 484                                         handle_children(ypdb);
 485                                         if (children == (MAX_CHILDREN - 1))
 486                                                 checkwork();
 487                                 }
 488                         }
 489                         svc_getreqset(&fdsr);
 490                         break;
 491                 }
 492         }
 493
 494         /* NOTREACHED */
 495         exit(1);
 496 }
 497
 498 void
 499 checkwork(void)
 500 {
 501         struct _dom_binding *ypdb;
 502
 503         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
 504                 ping(ypdb);
 505 }
 506
 507 /* The clnt_broadcast() callback mechanism sucks. */
 508
 509 /*
 510  * Receive results from broadcaster. Don't worry about passing
 511  * bogus info to rpc_received() -- it can handle it. Note that we
 512  * must be sure to invalidate the dom_pipe_fds descriptors here:
 513  * since descriptors can be re-used, we have to make sure we
 514  * don't mistake one of the RPC descriptors for one of the pipes.
 515  * What's weird is that forgetting to invalidate the pipe descriptors
 516  * doesn't always result in an error (otherwise I would have caught
 517  * the mistake much sooner), even though logically it should.
 518  */
 519 void
 520 handle_children(struct _dom_binding *ypdb)
 521 {
 522         char buf[YPMAXDOMAIN + 1];
 523         struct sockaddr_in addr;
 524         int d = 0, a = 0;
 525         struct _dom_binding *y, *prev = NULL;
 526         char path[MAXPATHLEN];
 527
 528         if ((d = read(READFD, &buf, sizeof(buf))) <= 0)
 529                 syslog(LOG_WARNING, "could not read from child: %m");
 530
 531         if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0)
 532                 syslog(LOG_WARNING, "could not read from child: %m");
 533
 534         close(READFD);
 535         FD_CLR(READFD, &fdsr);
 536         FD_CLR(READFD, &svc_fdset);
 537         READFD = WRITEFD = -1;
 538         if (d > 0 && a > 0)
 539                 rpc_received((char *)&buf, &addr, 0);
 540         else {
 541                 for (y = ypbindlist; y; y = y->dom_pnext) {
 542                         if (y == ypdb)
 543                                 break;
 544                         prev = y;
 545                 }
 546                 switch (ypdb->dom_default) {
 547                 case 0:
 548                         if (prev == NULL)
 549                                 ypbindlist = y->dom_pnext;
 550                         else
 551                                 prev->dom_pnext = y->dom_pnext;
 552                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 553                                 ypdb->dom_domain, YPVERS);
 554                         close(ypdb->dom_lockfd);
 555                         unlink(path);
 556                         free(ypdb);
 557                         domains--;
 558                         return;
 559                 case 1:
 560                         ypdb->dom_broadcast_pid = 0;
 561                         ypdb->dom_alive = 0;
 562                         broadcast(ypdb);
 563                         return;
 564                 default:
 565                         break;
 566                 }
 567         }
 568
 569         return;
 570 }
 571
 572 /*
 573  * Send our dying words back to our parent before we perish.
 574  */
 575 int
 576 tell_parent(char *dom, struct sockaddr_in *addr)
 577 {
 578         char buf[YPMAXDOMAIN + 1];
 579         struct timeval timeout;
 580         fd_set fds;
 581
 582         timeout.tv_sec = 5;
 583         timeout.tv_usec = 0;
 584
 585         sprintf(buf, "%s", broad_domain->dom_domain);
 586         if (write(BROADFD, &buf, sizeof(buf)) < 0)
 587                 return(1);
 588
 589         /*
 590          * Stay in sync with parent: wait for it to read our first
 591          * message before sending the second.
 592          */
 593
 594         FD_ZERO(&fds);
 595         FD_SET(BROADFD, &fds);
 596         if (select(FD_SETSIZE, NULL, &fds, NULL, &timeout) == -1)
 597                 return(1);
 598         if (FD_ISSET(BROADFD, &fds)) {
 599                 if (write(BROADFD, addr, sizeof(struct sockaddr_in)) < 0)
 600                         return(1);
 601         } else {
 602                 return(1);
 603         }
 604
 605         close(BROADFD);
 606         return (0);
 607 }
 608
 609 bool_t
 610 broadcast_result(caddr_t out, struct sockaddr_in *addr)
 611 {
 612         if (retries >= MAX_RETRIES) {
 613                 bzero((char *)addr, sizeof(struct sockaddr_in));
 614                 if (tell_parent(broad_domain->dom_domain, addr))
 615                         syslog(LOG_WARNING, "lost connection to parent");
 616                 return (TRUE);
 617         }
 618
 619         if (yp_restricted && verify(addr->sin_addr)) {
 620                 retries++;
 621                 syslog(LOG_NOTICE, "NIS server at %s not in restricted mode access list -- rejecting.\n",inet_ntoa(addr->sin_addr));
 622                 return (FALSE);
 623         } else {
 624                 if (tell_parent(broad_domain->dom_domain, addr))
 625                         syslog(LOG_WARNING, "lost connection to parent");
 626                 return (TRUE);
 627         }
 628 }
 629
 630 /*
 631  * The right way to send RPC broadcasts.
 632  * Use the clnt_broadcast() RPC service. Unfortunately, clnt_broadcast()
 633  * blocks while waiting for replies, so we have to fork off separate
 634  * broadcaster processes that do the waiting and then transmit their
 635  * results back to the parent for processing. We also have to remember
 636  * to save the name of the domain we're trying to bind in a global
 637  * variable since clnt_broadcast() provides no way to pass things to
 638  * the 'eachresult' callback function.
 639  */
 640 void
 641 broadcast(struct _dom_binding *ypdb)
 642 {
 643         bool_t out = FALSE;
 644         enum clnt_stat stat;
 645
 646         if (children >= MAX_CHILDREN || ypdb->dom_broadcast_pid)
 647                 return;
 648
 649         if (pipe(ypdb->dom_pipe_fds) < 0) {
 650                 syslog(LOG_WARNING, "pipe: %m");
 651                 return;
 652         }
 653
 654         if (ypdb->dom_vers == -1 && (long)ypdb->dom_server_addr.sin_addr.s_addr)
 655                 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding",
 656                 inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain);
 657
 658         broad_domain = ypdb;
 659         flock(ypdb->dom_lockfd, LOCK_UN);
 660
 661         switch ((ypdb->dom_broadcast_pid = fork())) {
 662         case 0:
 663                 close(READFD);
 664                 signal(SIGCHLD, SIG_DFL);
 665                 signal(SIGTERM, SIG_DFL);
 666                 break;
 667         case -1:
 668                 syslog(LOG_WARNING, "fork: %m");
 669                 close(READFD);
 670                 close(WRITEFD);
 671                 return;
 672         default:
 673                 close(WRITEFD);
 674                 FD_SET(READFD, &svc_fdset);
 675                 children++;
 676                 return;
 677         }
 678
 679         /* Release all locks before doing anything else. */
 680         while (ypbindlist) {
 681                 close(ypbindlist->dom_lockfd);
 682                 ypbindlist = ypbindlist->dom_pnext;
 683         }
 684         close(yplockfd);
 685
 686         /*
 687          * Special 'many-cast' behavior. If we're in restricted mode,
 688          * we have a list of possible server addresses to try. What
 689          * we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK
 690          * procedure and time the replies. Whoever replies fastest
 691          * gets to be our server. Note that this is not a broadcast
 692          * operation: we transmit uni-cast datagrams only.
 693          */
 694         if (yp_restricted && yp_manycast) {
 695                 short                   port;
 696                 int                     i;
 697                 struct sockaddr_in      sin;
 698
 699                 i = __yp_ping(restricted_addrs, yp_restricted,
 700                                 ypdb->dom_domain, &port);
 701                 if (i == -1) {
 702                         bzero((char *)&ypdb->dom_server_addr,
 703                                                 sizeof(struct sockaddr_in));
 704                         if (tell_parent(ypdb->dom_domain,
 705                                         &ypdb->dom_server_addr))
 706                         syslog(LOG_WARNING, "lost connection to parent");
 707                 } else {
 708                         bzero((char *)&sin, sizeof(struct sockaddr_in));
 709                         bcopy((char *)&restricted_addrs[i],
 710                                 (char *)&sin.sin_addr, sizeof(struct in_addr));
 711                         sin.sin_family = AF_INET;
 712                         sin.sin_port = port;
 713                         if (tell_parent(broad_domain->dom_domain, &sin))
 714                                 syslog(LOG_WARNING,
 715                                         "lost connection to parent");
 716                 }
 717                 _exit(0);
 718         }
 719
 720         retries = 0;
 721
 722         {
 723                 char *ptr;
 724
 725                 ptr = (char *)&ypdb->dom_domain;
 726                 stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK,
 727                         xdr_domainname, (char *)&ptr, xdr_bool, (char *)&out,
 728                         broadcast_result);
 729         }
 730
 731         if (stat != RPC_SUCCESS) {
 732                 bzero((char *)&ypdb->dom_server_addr,
 733                                                 sizeof(struct sockaddr_in));
 734                 if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr))
 735                         syslog(LOG_WARNING, "lost connection to parent");
 736         }
 737
 738         _exit(0);
 739 }
 740
 741 /*
 742  * The right way to check if a server is alive.
 743  * Attempt to get a client handle pointing to the server and send a
 744  * YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE,
 745  * we invalidate this binding entry and send out a broadcast to try to
 746  * establish a new binding. Note that we treat non-default domains
 747  * specially: once bound, we keep tabs on our server, but if it
 748  * goes away and fails to respond after one round of broadcasting, we
 749  * abandon it until a client specifically references it again. We make
 750  * every effort to keep our default domain bound, however, since we
 751  * need it to keep the system on its feet.
 752  */
 753 int
 754 ping(struct _dom_binding *ypdb)
 755 {
 756         bool_t out;
 757         struct timeval interval, timeout;
 758         enum clnt_stat stat;
 759         int rpcsock = RPC_ANYSOCK;
 760         CLIENT *client_handle;
 761
 762         interval.tv_sec = FAIL_THRESHOLD;
 763         interval.tv_usec = 0;
 764         timeout.tv_sec = FAIL_THRESHOLD;
 765         timeout.tv_usec = 0;
 766
 767         if (ypdb->dom_broadcast_pid)
 768                 return(1);
 769
 770         if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr,
 771                 YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE,
 772                 RPCSMALLMSGSIZE)) == (CLIENT *)NULL) {
 773                 /* Can't get a handle: we're dead. */
 774                 ypdb->dom_alive = 0;
 775                 ypdb->dom_vers = -1;
 776                 broadcast(ypdb);
 777                 return(1);
 778         }
 779
 780         {
 781                 char *ptr;
 782
 783                 ptr = (char *)&ypdb->dom_domain;
 784
 785                 if ((stat = clnt_call(client_handle, YPPROC_DOMAIN,
 786                         xdr_domainname, (char *)&ptr, xdr_bool, (char *)&out,
 787                         timeout)) != RPC_SUCCESS || out == FALSE) {
 788                         ypdb->dom_alive = 0;
 789                         ypdb->dom_vers = -1;
 790                         clnt_destroy(client_handle);
 791                         broadcast(ypdb);
 792                         return(1);
 793                 }
 794         }
 795
 796         clnt_destroy(client_handle);
 797         return(0);
 798 }
 799
 800 void
 801 rpc_received(char *dom, struct sockaddr_in *raddrp, int force)
 802 {
 803         struct _dom_binding *ypdb, *prev = NULL;
 804         struct iovec iov[2];
 805         struct ypbind_resp ybr;
 806         char path[MAXPATHLEN];
 807         int fd;
 808
 809         /*printf("returned from %s/%d about %s\n", inet_ntoa(raddrp->sin_addr),
 810                ntohs(raddrp->sin_port), dom);*/
 811
 812         if (dom == NULL)
 813                 return;
 814
 815         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 816                 if (strcmp(ypdb->dom_domain, dom) == 0)
 817                         break;
 818                 prev = ypdb;
 819         }
 820
 821         if (ypdb && force) {
 822                 if (ypdb->dom_broadcast_pid) {
 823                         kill(ypdb->dom_broadcast_pid, SIGINT);
 824                         close(READFD);
 825                         FD_CLR(READFD, &fdsr);
 826                         FD_CLR(READFD, &svc_fdset);
 827                         READFD = WRITEFD = -1;
 828                 }
 829         }
 830
 831         /* if in secure mode, check originating port number */
 832         if ((ypsecuremode && (ntohs(raddrp->sin_port) >= IPPORT_RESERVED))) {
 833             syslog(LOG_WARNING, "Rejected NIS server on [%s/%d] for domain %s.",
 834                    inet_ntoa(raddrp->sin_addr), ntohs(raddrp->sin_port),
 835                    dom);
 836             if (ypdb != NULL) {
 837                 ypdb->dom_broadcast_pid = 0;
 838                 ypdb->dom_alive = 0;
 839             }
 840             return;
 841         }
 842
 843         if (raddrp->sin_addr.s_addr == (long)0) {
 844                 switch (ypdb->dom_default) {
 845                 case 0:
 846                         if (prev == NULL)
 847                                 ypbindlist = ypdb->dom_pnext;
 848                         else
 849                                 prev->dom_pnext = ypdb->dom_pnext;
 850                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 851                                 ypdb->dom_domain, YPVERS);
 852                         close(ypdb->dom_lockfd);
 853                         unlink(path);
 854                         free(ypdb);
 855                         domains--;
 856                         return;
 857                 case 1:
 858                         ypdb->dom_broadcast_pid = 0;
 859                         ypdb->dom_alive = 0;
 860                         broadcast(ypdb);
 861                         return;
 862                 default:
 863                         break;
 864                 }
 865         }
 866
 867         if (ypdb == NULL) {
 868                 if (force == 0)
 869                         return;
 870                 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb);
 871                 if (ypdb == NULL) {
 872                         syslog(LOG_WARNING, "malloc: %m");
 873                         return;
 874                 }
 875                 bzero((char *)ypdb, sizeof *ypdb);
 876                 strncpy(ypdb->dom_domain, dom, sizeof ypdb->dom_domain);
 877                 ypdb->dom_lockfd = -1;
 878                 ypdb->dom_default = 0;
 879                 ypdb->dom_pnext = ypbindlist;
 880                 ypbindlist = ypdb;
 881         }
 882
 883         /* We've recovered from a crash: inform the world. */
 884         if (ypdb->dom_vers == -1 && ypdb->dom_server_addr.sin_addr.s_addr)
 885                 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" OK",
 886                 inet_ntoa(raddrp->sin_addr), ypdb->dom_domain);
 887
 888         bcopy((char *)raddrp, (char *)&ypdb->dom_server_addr,
 889                 sizeof ypdb->dom_server_addr);
 890
 891         ypdb->dom_vers = YPVERS;
 892         ypdb->dom_alive = 1;
 893         ypdb->dom_broadcast_pid = 0;
 894
 895         if (ypdb->dom_lockfd != -1)
 896                 close(ypdb->dom_lockfd);
 897
 898         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 899                 ypdb->dom_domain, ypdb->dom_vers);
 900 #ifdef O_SHLOCK
 901         if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) {
 902                 mkdir(BINDINGDIR, 0755);
 903                 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1)
 904                         return;
 905         }
 906 #else
 907         if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) {
 908                 mkdir(BINDINGDIR, 0755);
 909                 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1)
 910                         return;
 911         }
 912         flock(fd, LOCK_SH);
 913 #endif
 914
 915         /*
 916          * ok, if BINDINGDIR exists, and we can create the binding file,
 917          * then write to it..
 918          */
 919         ypdb->dom_lockfd = fd;
 920
 921         iov[0].iov_base = (caddr_t)&(udptransp->xp_port);
 922         iov[0].iov_len = sizeof udptransp->xp_port;
 923         iov[1].iov_base = (caddr_t)&ybr;
 924         iov[1].iov_len = sizeof ybr;
 925
 926         bzero(&ybr, sizeof ybr);
 927         ybr.ypbind_status = YPBIND_SUCC_VAL;
 928         *(u_int32_t *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = raddrp->sin_addr.s_addr;
 929         *(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = raddrp->sin_port;
 930
 931         if (writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) {
 932                 syslog(LOG_WARNING, "write: %m");
 933                 close(ypdb->dom_lockfd);
 934                 ypdb->dom_lockfd = -1;
 935                 return;
 936         }
 937 }
 938
 939 /*
 940  * Check address against list of allowed servers. Return 0 if okay,
 941  * 1 if not matched.
 942  */
 943 int
 944 verify(struct in_addr addr)
 945 {
 946         int i;
 947
 948         for (i = 0; i < RESTRICTED_SERVERS; i++)
 949                 if (!bcmp((char *)&addr, (char *)&restricted_addrs[i],
 950                         sizeof(struct in_addr)))
 951                         return(0);
 952
 953         return(1);
 954 }
 955
 956 /*
 957  * Try to set restricted mode. We default to normal mode if we can't
 958  * resolve the specified hostnames.
 959  */
 960 void
 961 yp_restricted_mode(char *args)
 962 {
 963         struct hostent *h;
 964         int i = 0;
 965         char *s;
 966
 967         /* Find the restricted domain. */
 968         if ((s = strsep(&args, ",")) == NULL)
 969                 return;
 970         domain_name = s;
 971
 972         /* Get the addresses of the servers. */
 973         while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) {
 974                 if ((h = gethostbyname(s)) == NULL)
 975                         return;
 976                 bcopy ((char *)h->h_addr_list[0], (char *)&restricted_addrs[i],
 977                         sizeof(struct in_addr));
 978         i++;
 979         }
 980
 981         /* ypset and ypsetme not allowed with restricted mode */
 982         ypsetmode = YPSET_NO;
 983
 984         yp_restricted = i;
 985         return;
 986 }