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 1.5 2004/12/18 22:48:14 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 reaper(int sig)
 344 {
 345         int st;
 346
 347         while (wait3(&st, WNOHANG, NULL) > 0)
 348                 children--;
 349 }
 350
 351 void terminate(int sig)
 352 {
 353         struct _dom_binding *ypdb;
 354         char path[MAXPATHLEN];
 355
 356         if (ppid != getpid())
 357                 exit(0);
 358
 359         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 360                 close(ypdb->dom_lockfd);
 361                 if (ypdb->dom_broadcast_pid)
 362                         kill(ypdb->dom_broadcast_pid, SIGINT);
 363                 sprintf(path, "%s/%s.%ld", BINDINGDIR,
 364                         ypdb->dom_domain, ypdb->dom_vers);
 365                 unlink(path);
 366         }
 367         close(yplockfd);
 368         unlink(YPBINDLOCK);
 369         pmap_unset(YPBINDPROG, YPBINDVERS);
 370         exit(0);
 371 }
 372
 373 int
 374 main(int argc, char **argv)
 375 {
 376         struct timeval tv;
 377         int i;
 378         DIR *dird;
 379         struct dirent *dirp;
 380         struct _dom_binding *ypdb, *next;
 381
 382         /* Check that another ypbind isn't already running. */
 383         if ((yplockfd = (open(YPBINDLOCK, O_RDONLY|O_CREAT, 0444))) == -1)
 384                 err(1, "%s", YPBINDLOCK);
 385
 386         if (flock(yplockfd, LOCK_EX|LOCK_NB) == -1 && errno == EWOULDBLOCK)
 387                 errx(1, "another ypbind is already running. Aborting");
 388
 389         /* XXX domainname will be overriden if we use restricted mode */
 390         yp_get_default_domain(&domain_name);
 391         if (domain_name[0] == '\0')
 392                 errx(1, "domainname not set. Aborting");
 393
 394         for (i = 1; i<argc; i++) {
 395                 if (strcmp("-ypset", argv[i]) == 0)
 396                         ypsetmode = YPSET_ALL;
 397                 else if (strcmp("-ypsetme", argv[i]) == 0)
 398                         ypsetmode = YPSET_LOCAL;
 399                 else if (strcmp("-s", argv[i]) == 0)
 400                         ypsecuremode++;
 401                 else if (strcmp("-S", argv[i]) == 0 && argc > i)
 402                         yp_restricted_mode(argv[i+1]);
 403                 else if (strcmp("-m", argv[i]) == 0)
 404                         yp_manycast++;
 405         }
 406
 407         /* blow away everything in BINDINGDIR (if it exists) */
 408
 409         if ((dird = opendir(BINDINGDIR)) != NULL) {
 410                 char path[MAXPATHLEN];
 411                 while ((dirp = readdir(dird)) != NULL)
 412                         if (strcmp(dirp->d_name, ".") &&
 413                             strcmp(dirp->d_name, "..")) {
 414                                 sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name);
 415                                 unlink(path);
 416                         }
 417                 closedir(dird);
 418         }
 419
 420 #ifdef DAEMON
 421         if (daemon(0,0))
 422                 err(1, "fork");
 423 #endif
 424
 425         pmap_unset(YPBINDPROG, YPBINDVERS);
 426
 427         udptransp = svcudp_create(RPC_ANYSOCK);
 428         if (udptransp == NULL)
 429                 errx(1, "cannot create udp service");
 430         if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 431             IPPROTO_UDP))
 432                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)");
 433
 434         tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0);
 435         if (tcptransp == NULL)
 436                 errx(1, "cannot create tcp service");
 437
 438         if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 439             IPPROTO_TCP))
 440                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)");
 441
 442         /* build initial domain binding, make it "unsuccessful" */
 443         ypbindlist = (struct _dom_binding *)malloc(sizeof *ypbindlist);
 444         if (ypbindlist == NULL)
 445                 errx(1, "malloc");
 446         bzero((char *)ypbindlist, sizeof *ypbindlist);
 447         strncpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain);
 448         ypbindlist->dom_vers = YPVERS;
 449         ypbindlist->dom_alive = 0;
 450         ypbindlist->dom_lockfd = -1;
 451         ypbindlist->dom_default = 1;
 452         domains++;
 453
 454         signal(SIGCHLD, reaper);
 455         signal(SIGTERM, terminate);
 456
 457         ppid = getpid(); /* Remember who we are. */
 458
 459         openlog(argv[0], LOG_PID, LOG_DAEMON);
 460
 461         /* Kick off the default domain */
 462         broadcast(ypbindlist);
 463
 464         while (1) {
 465                 fdsr = svc_fdset;
 466
 467                 tv.tv_sec = 60;
 468                 tv.tv_usec = 0;
 469
 470                 switch (select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) {
 471                 case 0:
 472                         checkwork();
 473                         break;
 474                 case -1:
 475                         if (errno != EINTR)
 476                                 syslog(LOG_WARNING, "select: %m");
 477                         break;
 478                 default:
 479                         for (ypdb = ypbindlist; ypdb; ypdb = next) {
 480                                 next = ypdb->dom_pnext;
 481                                 if (READFD > 0 && FD_ISSET(READFD, &fdsr)) {
 482                                         handle_children(ypdb);
 483                                         if (children == (MAX_CHILDREN - 1))
 484                                                 checkwork();
 485                                 }
 486                         }
 487                         svc_getreqset(&fdsr);
 488                         break;
 489                 }
 490         }
 491
 492         /* NOTREACHED */
 493         exit(1);
 494 }
 495
 496 void
 497 checkwork(void)
 498 {
 499         struct _dom_binding *ypdb;
 500
 501         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
 502                 ping(ypdb);
 503 }
 504
 505 /* The clnt_broadcast() callback mechanism sucks. */
 506
 507 /*
 508  * Receive results from broadcaster. Don't worry about passing
 509  * bogus info to rpc_received() -- it can handle it. Note that we
 510  * must be sure to invalidate the dom_pipe_fds descriptors here:
 511  * since descriptors can be re-used, we have to make sure we
 512  * don't mistake one of the RPC descriptors for one of the pipes.
 513  * What's weird is that forgetting to invalidate the pipe descriptors
 514  * doesn't always result in an error (otherwise I would have caught
 515  * the mistake much sooner), even though logically it should.
 516  */
 517 void handle_children(struct _dom_binding *ypdb)
 518 {
 519         char buf[YPMAXDOMAIN + 1];
 520         struct sockaddr_in addr;
 521         int d = 0, a = 0;
 522         struct _dom_binding *y, *prev = NULL;
 523         char path[MAXPATHLEN];
 524
 525         if ((d = read(READFD, &buf, sizeof(buf))) <= 0)
 526                 syslog(LOG_WARNING, "could not read from child: %m");
 527
 528         if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0)
 529                 syslog(LOG_WARNING, "could not read from child: %m");
 530
 531         close(READFD);
 532         FD_CLR(READFD, &fdsr);
 533         FD_CLR(READFD, &svc_fdset);
 534         READFD = WRITEFD = -1;
 535         if (d > 0 && a > 0)
 536                 rpc_received((char *)&buf, &addr, 0);
 537         else {
 538                 for (y = ypbindlist; y; y = y->dom_pnext) {
 539                         if (y == ypdb)
 540                                 break;
 541                         prev = y;
 542                 }
 543                 switch (ypdb->dom_default) {
 544                 case 0:
 545                         if (prev == NULL)
 546                                 ypbindlist = y->dom_pnext;
 547                         else
 548                                 prev->dom_pnext = y->dom_pnext;
 549                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 550                                 ypdb->dom_domain, YPVERS);
 551                         close(ypdb->dom_lockfd);
 552                         unlink(path);
 553                         free(ypdb);
 554                         domains--;
 555                         return;
 556                 case 1:
 557                         ypdb->dom_broadcast_pid = 0;
 558                         ypdb->dom_alive = 0;
 559                         broadcast(ypdb);
 560                         return;
 561                 default:
 562                         break;
 563                 }
 564         }
 565
 566         return;
 567 }
 568
 569 /*
 570  * Send our dying words back to our parent before we perish.
 571  */
 572 int
 573 tell_parent(char *dom, struct sockaddr_in *addr)
 574 {
 575         char buf[YPMAXDOMAIN + 1];
 576         struct timeval timeout;
 577         fd_set fds;
 578
 579         timeout.tv_sec = 5;
 580         timeout.tv_usec = 0;
 581
 582         sprintf(buf, "%s", broad_domain->dom_domain);
 583         if (write(BROADFD, &buf, sizeof(buf)) < 0)
 584                 return(1);
 585
 586         /*
 587          * Stay in sync with parent: wait for it to read our first
 588          * message before sending the second.
 589          */
 590
 591         FD_ZERO(&fds);
 592         FD_SET(BROADFD, &fds);
 593         if (select(FD_SETSIZE, NULL, &fds, NULL, &timeout) == -1)
 594                 return(1);
 595         if (FD_ISSET(BROADFD, &fds)) {
 596                 if (write(BROADFD, addr, sizeof(struct sockaddr_in)) < 0)
 597                         return(1);
 598         } else {
 599                 return(1);
 600         }
 601
 602         close(BROADFD);
 603         return (0);
 604 }
 605
 606 bool_t broadcast_result(caddr_t out, struct sockaddr_in *addr)
 607 {
 608         if (retries >= MAX_RETRIES) {
 609                 bzero((char *)addr, sizeof(struct sockaddr_in));
 610                 if (tell_parent(broad_domain->dom_domain, addr))
 611                         syslog(LOG_WARNING, "lost connection to parent");
 612                 return (TRUE);
 613         }
 614
 615         if (yp_restricted && verify(addr->sin_addr)) {
 616                 retries++;
 617                 syslog(LOG_NOTICE, "NIS server at %s not in restricted mode access list -- rejecting.\n",inet_ntoa(addr->sin_addr));
 618                 return (FALSE);
 619         } else {
 620                 if (tell_parent(broad_domain->dom_domain, addr))
 621                         syslog(LOG_WARNING, "lost connection to parent");
 622                 return (TRUE);
 623         }
 624 }
 625
 626 /*
 627  * The right way to send RPC broadcasts.
 628  * Use the clnt_broadcast() RPC service. Unfortunately, clnt_broadcast()
 629  * blocks while waiting for replies, so we have to fork off separate
 630  * broadcaster processes that do the waiting and then transmit their
 631  * results back to the parent for processing. We also have to remember
 632  * to save the name of the domain we're trying to bind in a global
 633  * variable since clnt_broadcast() provides no way to pass things to
 634  * the 'eachresult' callback function.
 635  */
 636 void
 637 broadcast(struct _dom_binding *ypdb)
 638 {
 639         bool_t out = FALSE;
 640         enum clnt_stat stat;
 641
 642         if (children >= MAX_CHILDREN || ypdb->dom_broadcast_pid)
 643                 return;
 644
 645         if (pipe(ypdb->dom_pipe_fds) < 0) {
 646                 syslog(LOG_WARNING, "pipe: %m");
 647                 return;
 648         }
 649
 650         if (ypdb->dom_vers == -1 && (long)ypdb->dom_server_addr.sin_addr.s_addr)
 651                 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding",
 652                 inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain);
 653
 654         broad_domain = ypdb;
 655         flock(ypdb->dom_lockfd, LOCK_UN);
 656
 657         switch ((ypdb->dom_broadcast_pid = fork())) {
 658         case 0:
 659                 close(READFD);
 660                 signal(SIGCHLD, SIG_DFL);
 661                 signal(SIGTERM, SIG_DFL);
 662                 break;
 663         case -1:
 664                 syslog(LOG_WARNING, "fork: %m");
 665                 close(READFD);
 666                 close(WRITEFD);
 667                 return;
 668         default:
 669                 close(WRITEFD);
 670                 FD_SET(READFD, &svc_fdset);
 671                 children++;
 672                 return;
 673         }
 674
 675         /* Release all locks before doing anything else. */
 676         while (ypbindlist) {
 677                 close(ypbindlist->dom_lockfd);
 678                 ypbindlist = ypbindlist->dom_pnext;
 679         }
 680         close(yplockfd);
 681
 682         /*
 683          * Special 'many-cast' behavior. If we're in restricted mode,
 684          * we have a list of possible server addresses to try. What
 685          * we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK
 686          * procedure and time the replies. Whoever replies fastest
 687          * gets to be our server. Note that this is not a broadcast
 688          * operation: we transmit uni-cast datagrams only.
 689          */
 690         if (yp_restricted && yp_manycast) {
 691                 short                   port;
 692                 int                     i;
 693                 struct sockaddr_in      sin;
 694
 695                 i = __yp_ping(restricted_addrs, yp_restricted,
 696                                 ypdb->dom_domain, &port);
 697                 if (i == -1) {
 698                         bzero((char *)&ypdb->dom_server_addr,
 699                                                 sizeof(struct sockaddr_in));
 700                         if (tell_parent(ypdb->dom_domain,
 701                                         &ypdb->dom_server_addr))
 702                         syslog(LOG_WARNING, "lost connection to parent");
 703                 } else {
 704                         bzero((char *)&sin, sizeof(struct sockaddr_in));
 705                         bcopy((char *)&restricted_addrs[i],
 706                                 (char *)&sin.sin_addr, sizeof(struct in_addr));
 707                         sin.sin_family = AF_INET;
 708                         sin.sin_port = port;
 709                         if (tell_parent(broad_domain->dom_domain, &sin))
 710                                 syslog(LOG_WARNING,
 711                                         "lost connection to parent");
 712                 }
 713                 _exit(0);
 714         }
 715
 716         retries = 0;
 717
 718         {
 719                 char *ptr;
 720
 721                 ptr = (char *)&ypdb->dom_domain;
 722                 stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK,
 723                         xdr_domainname, (char *)&ptr, xdr_bool, (char *)&out,
 724                         broadcast_result);
 725         }
 726
 727         if (stat != RPC_SUCCESS) {
 728                 bzero((char *)&ypdb->dom_server_addr,
 729                                                 sizeof(struct sockaddr_in));
 730                 if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr))
 731                         syslog(LOG_WARNING, "lost connection to parent");
 732         }
 733
 734         _exit(0);
 735 }
 736
 737 /*
 738  * The right way to check if a server is alive.
 739  * Attempt to get a client handle pointing to the server and send a
 740  * YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE,
 741  * we invalidate this binding entry and send out a broadcast to try to
 742  * establish a new binding. Note that we treat non-default domains
 743  * specially: once bound, we keep tabs on our server, but if it
 744  * goes away and fails to respond after one round of broadcasting, we
 745  * abandon it until a client specifically references it again. We make
 746  * every effort to keep our default domain bound, however, since we
 747  * need it to keep the system on its feet.
 748  */
 749 int
 750 ping(struct _dom_binding *ypdb)
 751 {
 752         bool_t out;
 753         struct timeval interval, timeout;
 754         enum clnt_stat stat;
 755         int rpcsock = RPC_ANYSOCK;
 756         CLIENT *client_handle;
 757
 758         interval.tv_sec = FAIL_THRESHOLD;
 759         interval.tv_usec = 0;
 760         timeout.tv_sec = FAIL_THRESHOLD;
 761         timeout.tv_usec = 0;
 762
 763         if (ypdb->dom_broadcast_pid)
 764                 return(1);
 765
 766         if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr,
 767                 YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE,
 768                 RPCSMALLMSGSIZE)) == (CLIENT *)NULL) {
 769                 /* Can't get a handle: we're dead. */
 770                 ypdb->dom_alive = 0;
 771                 ypdb->dom_vers = -1;
 772                 broadcast(ypdb);
 773                 return(1);
 774         }
 775
 776         {
 777                 char *ptr;
 778
 779                 ptr = (char *)&ypdb->dom_domain;
 780
 781                 if ((stat = clnt_call(client_handle, YPPROC_DOMAIN,
 782                         xdr_domainname, (char *)&ptr, xdr_bool, (char *)&out,
 783                         timeout)) != RPC_SUCCESS || out == FALSE) {
 784                         ypdb->dom_alive = 0;
 785                         ypdb->dom_vers = -1;
 786                         clnt_destroy(client_handle);
 787                         broadcast(ypdb);
 788                         return(1);
 789                 }
 790         }
 791
 792         clnt_destroy(client_handle);
 793         return(0);
 794 }
 795
 796 void rpc_received(char *dom, struct sockaddr_in *raddrp, int force)
 797 {
 798         struct _dom_binding *ypdb, *prev = NULL;
 799         struct iovec iov[2];
 800         struct ypbind_resp ybr;
 801         char path[MAXPATHLEN];
 802         int fd;
 803
 804         /*printf("returned from %s/%d about %s\n", inet_ntoa(raddrp->sin_addr),
 805                ntohs(raddrp->sin_port), dom);*/
 806
 807         if (dom == NULL)
 808                 return;
 809
 810         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 811                 if (strcmp(ypdb->dom_domain, dom) == 0)
 812                         break;
 813                 prev = ypdb;
 814         }
 815
 816         if (ypdb && force) {
 817                 if (ypdb->dom_broadcast_pid) {
 818                         kill(ypdb->dom_broadcast_pid, SIGINT);
 819                         close(READFD);
 820                         FD_CLR(READFD, &fdsr);
 821                         FD_CLR(READFD, &svc_fdset);
 822                         READFD = WRITEFD = -1;
 823                 }
 824         }
 825
 826         /* if in secure mode, check originating port number */
 827         if ((ypsecuremode && (ntohs(raddrp->sin_port) >= IPPORT_RESERVED))) {
 828             syslog(LOG_WARNING, "Rejected NIS server on [%s/%d] for domain %s.",
 829                    inet_ntoa(raddrp->sin_addr), ntohs(raddrp->sin_port),
 830                    dom);
 831             if (ypdb != NULL) {
 832                 ypdb->dom_broadcast_pid = 0;
 833                 ypdb->dom_alive = 0;
 834             }
 835             return;
 836         }
 837
 838         if (raddrp->sin_addr.s_addr == (long)0) {
 839                 switch (ypdb->dom_default) {
 840                 case 0:
 841                         if (prev == NULL)
 842                                 ypbindlist = ypdb->dom_pnext;
 843                         else
 844                                 prev->dom_pnext = ypdb->dom_pnext;
 845                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 846                                 ypdb->dom_domain, YPVERS);
 847                         close(ypdb->dom_lockfd);
 848                         unlink(path);
 849                         free(ypdb);
 850                         domains--;
 851                         return;
 852                 case 1:
 853                         ypdb->dom_broadcast_pid = 0;
 854                         ypdb->dom_alive = 0;
 855                         broadcast(ypdb);
 856                         return;
 857                 default:
 858                         break;
 859                 }
 860         }
 861
 862         if (ypdb == NULL) {
 863                 if (force == 0)
 864                         return;
 865                 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb);
 866                 if (ypdb == NULL) {
 867                         syslog(LOG_WARNING, "malloc: %m");
 868                         return;
 869                 }
 870                 bzero((char *)ypdb, sizeof *ypdb);
 871                 strncpy(ypdb->dom_domain, dom, sizeof ypdb->dom_domain);
 872                 ypdb->dom_lockfd = -1;
 873                 ypdb->dom_default = 0;
 874                 ypdb->dom_pnext = ypbindlist;
 875                 ypbindlist = ypdb;
 876         }
 877
 878         /* We've recovered from a crash: inform the world. */
 879         if (ypdb->dom_vers == -1 && ypdb->dom_server_addr.sin_addr.s_addr)
 880                 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" OK",
 881                 inet_ntoa(raddrp->sin_addr), ypdb->dom_domain);
 882
 883         bcopy((char *)raddrp, (char *)&ypdb->dom_server_addr,
 884                 sizeof ypdb->dom_server_addr);
 885
 886         ypdb->dom_vers = YPVERS;
 887         ypdb->dom_alive = 1;
 888         ypdb->dom_broadcast_pid = 0;
 889
 890         if (ypdb->dom_lockfd != -1)
 891                 close(ypdb->dom_lockfd);
 892
 893         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 894                 ypdb->dom_domain, ypdb->dom_vers);
 895 #ifdef O_SHLOCK
 896         if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) {
 897                 mkdir(BINDINGDIR, 0755);
 898                 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1)
 899                         return;
 900         }
 901 #else
 902         if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) {
 903                 mkdir(BINDINGDIR, 0755);
 904                 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1)
 905                         return;
 906         }
 907         flock(fd, LOCK_SH);
 908 #endif
 909
 910         /*
 911          * ok, if BINDINGDIR exists, and we can create the binding file,
 912          * then write to it..
 913          */
 914         ypdb->dom_lockfd = fd;
 915
 916         iov[0].iov_base = (caddr_t)&(udptransp->xp_port);
 917         iov[0].iov_len = sizeof udptransp->xp_port;
 918         iov[1].iov_base = (caddr_t)&ybr;
 919         iov[1].iov_len = sizeof ybr;
 920
 921         bzero(&ybr, sizeof ybr);
 922         ybr.ypbind_status = YPBIND_SUCC_VAL;
 923         *(u_int32_t *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = raddrp->sin_addr.s_addr;
 924         *(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = raddrp->sin_port;
 925
 926         if (writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) {
 927                 syslog(LOG_WARNING, "write: %m");
 928                 close(ypdb->dom_lockfd);
 929                 ypdb->dom_lockfd = -1;
 930                 return;
 931         }
 932 }
 933
 934 /*
 935  * Check address against list of allowed servers. Return 0 if okay,
 936  * 1 if not matched.
 937  */
 938 int
 939 verify(struct in_addr addr)
 940 {
 941         int i;
 942
 943         for (i = 0; i < RESTRICTED_SERVERS; i++)
 944                 if (!bcmp((char *)&addr, (char *)&restricted_addrs[i],
 945                         sizeof(struct in_addr)))
 946                         return(0);
 947
 948         return(1);
 949 }
 950
 951 /*
 952  * Try to set restricted mode. We default to normal mode if we can't
 953  * resolve the specified hostnames.
 954  */
 955 void
 956 yp_restricted_mode(char *args)
 957 {
 958         struct hostent *h;
 959         int i = 0;
 960         char *s;
 961
 962         /* Find the restricted domain. */
 963         if ((s = strsep(&args, ",")) == NULL)
 964                 return;
 965         domain_name = s;
 966
 967         /* Get the addresses of the servers. */
 968         while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) {
 969                 if ((h = gethostbyname(s)) == NULL)
 970                         return;
 971                 bcopy ((char *)h->h_addr_list[0], (char *)&restricted_addrs[i],
 972                         sizeof(struct in_addr));
 973         i++;
 974         }
 975
 976         /* ypset and ypsetme not allowed with restricted mode */
 977         ypsetmode = YPSET_NO;
 978
 979         yp_restricted = i;
 980         return;
 981 }