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 1.40 2004/10/17 19:33:33 stefanf Exp $
  30  */
  31
  32 #include <sys/param.h>
  33 #include <sys/types.h>
  34 #include <sys/wait.h>
  35 #include <sys/ioctl.h>
  36 #include <sys/signal.h>
  37 #include <sys/socket.h>
  38 #include <sys/file.h>
  39 #include <sys/fcntl.h>
  40 #include <sys/stat.h>
  41 #include <sys/uio.h>
  42 #include <ctype.h>
  43 #include <dirent.h>
  44 #include <err.h>
  45 #include <errno.h>
  46 #include <netdb.h>
  47 #include <signal.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <syslog.h>
  52 #include <unistd.h>
  53 #include <rpc/rpc.h>
  54 #include <rpc/xdr.h>
  55 #include <net/if.h>
  56 #include <netinet/in.h>
  57 #include <arpa/inet.h>
  58 #include <rpc/pmap_clnt.h>
  59 #include <rpc/pmap_prot.h>
  60 #include <rpc/pmap_rmt.h>
  61 #include <rpc/rpc_com.h>
  62 #include <rpcsvc/yp.h>
  63 #include <rpcsvc/ypclnt.h>
  64 #include "yp_ping.h"
  65
  66 #ifndef BINDINGDIR
  67 #define BINDINGDIR "/var/yp/binding"
  68 #endif
  69
  70 #ifndef YPBINDLOCK
  71 #define YPBINDLOCK "/var/run/ypbind.lock"
  72 #endif
  73
  74 struct _dom_binding {
  75         struct _dom_binding *dom_pnext;
  76         char dom_domain[YPMAXDOMAIN + 1];
  77         struct sockaddr_in dom_server_addr;
  78         long int dom_vers;
  79         int dom_lockfd;
  80         int dom_alive;
  81         int dom_broadcast_pid;
  82         int dom_pipe_fds[2];
  83         int dom_default;
  84 };
  85
  86 #define READFD ypdb->dom_pipe_fds[0]
  87 #define WRITEFD ypdb->dom_pipe_fds[1]
  88 #define BROADFD broad_domain->dom_pipe_fds[1]
  89
  90 extern bool_t xdr_domainname(), xdr_ypbind_resp();
  91 extern bool_t xdr_ypreq_key(), xdr_ypresp_val();
  92 extern bool_t xdr_ypbind_setdom();
  93
  94 void    checkwork(void);
  95 void    *ypbindproc_null_2_yp(SVCXPRT *, void *, CLIENT *);
  96 void    *ypbindproc_setdom_2_yp(SVCXPRT *, struct ypbind_setdom *, CLIENT *);
  97 void    rpc_received(char *, struct sockaddr_in *, int);
  98 void    broadcast(struct _dom_binding *);
  99 int     ping(struct _dom_binding *);
 100 int     tell_parent(char *, struct sockaddr_in *);
 101 void    handle_children(struct _dom_binding *);
 102 void    reaper(int);
 103 void    terminate(int) __dead2;
 104 void    yp_restricted_mode(char *);
 105 int     verify(struct in_addr);
 106
 107 char *domain_name;
 108 struct _dom_binding *ypbindlist;
 109 static struct _dom_binding *broad_domain;
 110
 111 #define YPSET_NO        0
 112 #define YPSET_LOCAL     1
 113 #define YPSET_ALL       2
 114 int ypsetmode = YPSET_NO;
 115 int ypsecuremode = 0;
 116 int ppid;
 117
 118 /*
 119  * Special restricted mode variables: when in restricted mode, only the
 120  * specified restricted_domain will be bound, and only the servers listed
 121  * in restricted_addrs will be used for binding.
 122  */
 123 #define RESTRICTED_SERVERS 10
 124 int yp_restricted = 0;
 125 int yp_manycast = 0;
 126 struct in_addr restricted_addrs[RESTRICTED_SERVERS];
 127
 128 /* No more than MAX_CHILDREN child broadcasters at a time. */
 129 #ifndef MAX_CHILDREN
 130 #define MAX_CHILDREN 5
 131 #endif
 132 /* No more than MAX_DOMAINS simultaneous domains */
 133 #ifndef MAX_DOMAINS
 134 #define MAX_DOMAINS 200
 135 #endif
 136 /* RPC timeout value */
 137 #ifndef FAIL_THRESHOLD
 138 #define FAIL_THRESHOLD 20
 139 #endif
 140
 141 /* Number of times to fish for a response froma particular set of hosts */
 142 #ifndef MAX_RETRIES
 143 #define MAX_RETRIES 30
 144 #endif
 145
 146 int retries = 0;
 147 int children = 0;
 148 int domains = 0;
 149 int yplockfd;
 150 fd_set fdsr;
 151
 152 SVCXPRT *udptransp, *tcptransp;
 153
 154 void *
 155 ypbindproc_null_2_yp(SVCXPRT *transp, void *argp, CLIENT *clnt)
 156 {
 157         static char res;
 158
 159         bzero(&res, sizeof(res));
 160         return &res;
 161 }
 162
 163 struct ypbind_resp *
 164 ypbindproc_domain_2_yp(SVCXPRT *transp, domainname *argp, CLIENT *clnt)
 165 {
 166         static struct ypbind_resp res;
 167         struct _dom_binding *ypdb;
 168         char path[MAXPATHLEN];
 169
 170         bzero(&res, sizeof res);
 171         res.ypbind_status = YPBIND_FAIL_VAL;
 172         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_NOSERV;
 173
 174         if (strchr(*argp, '/')) {
 175                 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
 176 rejecting.", *argp);
 177                 return(&res);
 178         }
 179
 180         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 181                 if (strcmp(ypdb->dom_domain, *argp) == 0)
 182                         break;
 183                 }
 184
 185         if (ypdb == NULL) {
 186                 if (yp_restricted) {
 187                         syslog(LOG_NOTICE, "Running in restricted mode -- request to bind domain \"%s\" rejected.\n", *argp);
 188                         return (&res);
 189                 }
 190
 191                 if (domains >= MAX_DOMAINS) {
 192                         syslog(LOG_WARNING, "domain limit (%d) exceeded",
 193                                                         MAX_DOMAINS);
 194                         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
 195                         return (&res);
 196                 }
 197                 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb);
 198                 if (ypdb == NULL) {
 199                         syslog(LOG_WARNING, "malloc: %m");
 200                         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
 201                         return (&res);
 202                 }
 203                 bzero(ypdb, sizeof *ypdb);
 204                 strncpy(ypdb->dom_domain, *argp, sizeof ypdb->dom_domain);
 205                 ypdb->dom_vers = YPVERS;
 206                 ypdb->dom_alive = 0;
 207                 ypdb->dom_default = 0;
 208                 ypdb->dom_lockfd = -1;
 209                 sprintf(path, "%s/%s.%ld", BINDINGDIR,
 210                                         ypdb->dom_domain, ypdb->dom_vers);
 211                 unlink(path);
 212                 ypdb->dom_pnext = ypbindlist;
 213                 ypbindlist = ypdb;
 214                 domains++;
 215         }
 216
 217         if (ping(ypdb)) {
 218                 return (&res);
 219         }
 220
 221         res.ypbind_status = YPBIND_SUCC_VAL;
 222         res.ypbind_resp_u.ypbind_error = 0; /* Success */
 223         *(u_int32_t *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr =
 224                 ypdb->dom_server_addr.sin_addr.s_addr;
 225         *(u_short *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port =
 226                 ypdb->dom_server_addr.sin_port;
 227         /*printf("domain %s at %s/%d\n", ypdb->dom_domain,
 228                 inet_ntoa(ypdb->dom_server_addr.sin_addr),
 229                 ntohs(ypdb->dom_server_addr.sin_port));*/
 230         return (&res);
 231 }
 232
 233 void *
 234 ypbindproc_setdom_2_yp(SVCXPRT *transp, ypbind_setdom *argp, CLIENT *clnt)
 235 {
 236         struct sockaddr_in *fromsin, bindsin;
 237         static char *result = NULL;
 238
 239         if (strchr(argp->ypsetdom_domain, '/')) {
 240                 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
 241 rejecting.", argp->ypsetdom_domain);
 242                 return(NULL);
 243         }
 244         fromsin = svc_getcaller(transp);
 245
 246         switch (ypsetmode) {
 247         case YPSET_LOCAL:
 248                 if (fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) {
 249                         svcerr_noprog(transp);
 250                         return(NULL);
 251                 }
 252                 break;
 253         case YPSET_ALL:
 254                 break;
 255         case YPSET_NO:
 256         default:
 257                 svcerr_noprog(transp);
 258                 return(NULL);
 259         }
 260
 261         if (ntohs(fromsin->sin_port) >= IPPORT_RESERVED) {
 262                 svcerr_noprog(transp);
 263                 return(NULL);
 264         }
 265
 266         if (argp->ypsetdom_vers != YPVERS) {
 267                 svcerr_noprog(transp);
 268                 return(NULL);
 269         }
 270
 271         bzero(&bindsin, sizeof bindsin);
 272         bindsin.sin_family = AF_INET;
 273         bindsin.sin_addr.s_addr = *(u_int32_t *)argp->ypsetdom_binding.ypbind_binding_addr;
 274         bindsin.sin_port = *(u_short *)argp->ypsetdom_binding.ypbind_binding_port;
 275         rpc_received(argp->ypsetdom_domain, &bindsin, 1);
 276
 277         return((void *) &result);
 278 }
 279
 280 void
 281 ypbindprog_2(struct svc_req *rqstp, SVCXPRT *transp)
 282 {
 283         union {
 284                 domainname ypbindproc_domain_2_arg;
 285                 struct ypbind_setdom ypbindproc_setdom_2_arg;
 286         } argument;
 287         struct authunix_parms *creds;
 288         char *result;
 289         bool_t (*xdr_argument)(), (*xdr_result)();
 290         char *(*local)();
 291
 292         switch (rqstp->rq_proc) {
 293         case YPBINDPROC_NULL:
 294                 xdr_argument = xdr_void;
 295                 xdr_result = xdr_void;
 296                 local = (char *(*)()) ypbindproc_null_2_yp;
 297                 break;
 298
 299         case YPBINDPROC_DOMAIN:
 300                 xdr_argument = xdr_domainname;
 301                 xdr_result = xdr_ypbind_resp;
 302                 local = (char *(*)()) ypbindproc_domain_2_yp;
 303                 break;
 304
 305         case YPBINDPROC_SETDOM:
 306                 switch (rqstp->rq_cred.oa_flavor) {
 307                 case AUTH_UNIX:
 308                         creds = (struct authunix_parms *)rqstp->rq_clntcred;
 309                         if (creds->aup_uid != 0) {
 310                                 svcerr_auth(transp, AUTH_BADCRED);
 311                                 return;
 312                         }
 313                         break;
 314                 default:
 315                         svcerr_auth(transp, AUTH_TOOWEAK);
 316                         return;
 317                 }
 318
 319                 xdr_argument = xdr_ypbind_setdom;
 320                 xdr_result = xdr_void;
 321                 local = (char *(*)()) ypbindproc_setdom_2_yp;
 322                 break;
 323
 324         default:
 325                 svcerr_noproc(transp);
 326                 return;
 327         }
 328         bzero(&argument, sizeof(argument));
 329         if (!svc_getargs(transp, (xdrproc_t)xdr_argument, &argument)) {
 330                 svcerr_decode(transp);
 331                 return;
 332         }
 333         result = (*local)(transp, &argument, rqstp);
 334         if (result != NULL &&
 335             !svc_sendreply(transp, (xdrproc_t)xdr_result, result)) {
 336                 svcerr_systemerr(transp);
 337         }
 338         return;
 339 }
 340
 341 /* Jack the reaper */
 342 void
 343 reaper(int sig)
 344 {
 345         int st;
 346
 347         while (wait3(&st, WNOHANG, NULL) > 0)
 348                 children--;
 349 }
 350
 351 void
 352 terminate(int sig)
 353 {
 354         struct _dom_binding *ypdb;
 355         char path[MAXPATHLEN];
 356
 357         if (ppid != getpid())
 358                 exit(0);
 359
 360         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 361                 close(ypdb->dom_lockfd);
 362                 if (ypdb->dom_broadcast_pid)
 363                         kill(ypdb->dom_broadcast_pid, SIGINT);
 364                 sprintf(path, "%s/%s.%ld", BINDINGDIR,
 365                         ypdb->dom_domain, ypdb->dom_vers);
 366                 unlink(path);
 367         }
 368         close(yplockfd);
 369         unlink(YPBINDLOCK);
 370         pmap_unset(YPBINDPROG, YPBINDVERS);
 371         exit(0);
 372 }
 373
 374 int
 375 main(int argc, char **argv)
 376 {
 377         struct timeval tv;
 378         int i;
 379         DIR *dird;
 380         struct dirent *dirp;
 381         struct _dom_binding *ypdb, *next;
 382
 383         /* Check that another ypbind isn't already running. */
 384         if ((yplockfd = (open(YPBINDLOCK, O_RDONLY|O_CREAT, 0444))) == -1)
 385                 err(1, "%s", YPBINDLOCK);
 386
 387         if (flock(yplockfd, LOCK_EX|LOCK_NB) == -1 && errno == EWOULDBLOCK)
 388                 errx(1, "another ypbind is already running. Aborting");
 389
 390         /* XXX domainname will be overridden if we use restricted mode */
 391         yp_get_default_domain(&domain_name);
 392         if (domain_name[0] == '\0')
 393                 errx(1, "domainname not set. Aborting");
 394
 395         for (i = 1; i<argc; i++) {
 396                 if (strcmp("-ypset", argv[i]) == 0)
 397                         ypsetmode = YPSET_ALL;
 398                 else if (strcmp("-ypsetme", argv[i]) == 0)
 399                         ypsetmode = YPSET_LOCAL;
 400                 else if (strcmp("-s", argv[i]) == 0)
 401                         ypsecuremode++;
 402                 else if (strcmp("-S", argv[i]) == 0 && argc > i)
 403                         yp_restricted_mode(argv[++i]);
 404                 else if (strcmp("-m", argv[i]) == 0)
 405                         yp_manycast++;
 406                 else
 407                         errx(1, "unknown option: %s", argv[i]);
 408         }
 409
 410         /* blow away everything in BINDINGDIR (if it exists) */
 411
 412         if ((dird = opendir(BINDINGDIR)) != NULL) {
 413                 char path[MAXPATHLEN];
 414                 while ((dirp = readdir(dird)) != NULL)
 415                         if (strcmp(dirp->d_name, ".") &&
 416                             strcmp(dirp->d_name, "..")) {
 417                                 sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name);
 418                                 unlink(path);
 419                         }
 420                 closedir(dird);
 421         }
 422
 423 #ifdef DAEMON
 424         if (daemon(0,0))
 425                 err(1, "fork");
 426 #endif
 427
 428         pmap_unset(YPBINDPROG, YPBINDVERS);
 429
 430         udptransp = svcudp_create(RPC_ANYSOCK);
 431         if (udptransp == NULL)
 432                 errx(1, "cannot create udp service");
 433         if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 434             IPPROTO_UDP))
 435                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)");
 436
 437         tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0);
 438         if (tcptransp == NULL)
 439                 errx(1, "cannot create tcp service");
 440
 441         if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 442             IPPROTO_TCP))
 443                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)");
 444
 445         /* build initial domain binding, make it "unsuccessful" */
 446         ypbindlist = (struct _dom_binding *)malloc(sizeof *ypbindlist);
 447         if (ypbindlist == NULL)
 448                 errx(1, "malloc");
 449         bzero(ypbindlist, sizeof *ypbindlist);
 450         strncpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain);
 451         ypbindlist->dom_vers = YPVERS;
 452         ypbindlist->dom_alive = 0;
 453         ypbindlist->dom_lockfd = -1;
 454         ypbindlist->dom_default = 1;
 455         domains++;
 456
 457         signal(SIGCHLD, reaper);
 458         signal(SIGTERM, terminate);
 459
 460         ppid = getpid(); /* Remember who we are. */
 461
 462         openlog(argv[0], LOG_PID, LOG_DAEMON);
 463
 464         /* Kick off the default domain */
 465         broadcast(ypbindlist);
 466
 467         while (1) {
 468                 fdsr = svc_fdset;
 469
 470                 tv.tv_sec = 60;
 471                 tv.tv_usec = 0;
 472
 473                 switch (select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) {
 474                 case 0:
 475                         checkwork();
 476                         break;
 477                 case -1:
 478                         if (errno != EINTR)
 479                                 syslog(LOG_WARNING, "select: %m");
 480                         break;
 481                 default:
 482                         for (ypdb = ypbindlist; ypdb; ypdb = next) {
 483                                 next = ypdb->dom_pnext;
 484                                 if (READFD > 0 && FD_ISSET(READFD, &fdsr)) {
 485                                         handle_children(ypdb);
 486                                         if (children == (MAX_CHILDREN - 1))
 487                                                 checkwork();
 488                                 }
 489                         }
 490                         svc_getreqset(&fdsr);
 491                         break;
 492                 }
 493         }
 494
 495         /* NOTREACHED */
 496         exit(1);
 497 }
 498
 499 void
 500 checkwork(void)
 501 {
 502         struct _dom_binding *ypdb;
 503
 504         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
 505                 ping(ypdb);
 506 }
 507
 508 /* The clnt_broadcast() callback mechanism sucks. */
 509
 510 /*
 511  * Receive results from broadcaster. Don't worry about passing
 512  * bogus info to rpc_received() -- it can handle it. Note that we
 513  * must be sure to invalidate the dom_pipe_fds descriptors here:
 514  * since descriptors can be re-used, we have to make sure we
 515  * don't mistake one of the RPC descriptors for one of the pipes.
 516  * What's weird is that forgetting to invalidate the pipe descriptors
 517  * doesn't always result in an error (otherwise I would have caught
 518  * the mistake much sooner), even though logically it should.
 519  */
 520 void
 521 handle_children(struct _dom_binding *ypdb)
 522 {
 523         char buf[YPMAXDOMAIN + 1];
 524         struct sockaddr_in addr;
 525         int d = 0, a = 0;
 526         struct _dom_binding *y, *prev = NULL;
 527         char path[MAXPATHLEN];
 528
 529         if ((d = read(READFD, &buf, sizeof(buf))) <= 0)
 530                 syslog(LOG_WARNING, "could not read from child: %m");
 531
 532         if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0)
 533                 syslog(LOG_WARNING, "could not read from child: %m");
 534
 535         close(READFD);
 536         FD_CLR(READFD, &fdsr);
 537         FD_CLR(READFD, &svc_fdset);
 538         READFD = WRITEFD = -1;
 539         if (d > 0 && a > 0)
 540                 rpc_received(buf, &addr, 0);
 541         else {
 542                 for (y = ypbindlist; y; y = y->dom_pnext) {
 543                         if (y == ypdb)
 544                                 break;
 545                         prev = y;
 546                 }
 547                 switch (ypdb->dom_default) {
 548                 case 0:
 549                         if (prev == NULL)
 550                                 ypbindlist = y->dom_pnext;
 551                         else
 552                                 prev->dom_pnext = y->dom_pnext;
 553                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 554                                 ypdb->dom_domain, YPVERS);
 555                         close(ypdb->dom_lockfd);
 556                         unlink(path);
 557                         free(ypdb);
 558                         domains--;
 559                         return;
 560                 case 1:
 561                         ypdb->dom_broadcast_pid = 0;
 562                         ypdb->dom_alive = 0;
 563                         broadcast(ypdb);
 564                         return;
 565                 default:
 566                         break;
 567                 }
 568         }
 569
 570         return;
 571 }
 572
 573 /*
 574  * Send our dying words back to our parent before we perish.
 575  */
 576 int
 577 tell_parent(char *dom, struct sockaddr_in *addr)
 578 {
 579         char buf[YPMAXDOMAIN + 1];
 580         struct timeval timeout;
 581         fd_set fds;
 582
 583         timeout.tv_sec = 5;
 584         timeout.tv_usec = 0;
 585
 586         sprintf(buf, "%s", broad_domain->dom_domain);
 587         if (write(BROADFD, &buf, sizeof(buf)) < 0)
 588                 return(1);
 589
 590         /*
 591          * Stay in sync with parent: wait for it to read our first
 592          * message before sending the second.
 593          */
 594
 595         FD_ZERO(&fds);
 596         FD_SET(BROADFD, &fds);
 597         if (select(FD_SETSIZE, NULL, &fds, NULL, &timeout) == -1)
 598                 return(1);
 599         if (FD_ISSET(BROADFD, &fds)) {
 600                 if (write(BROADFD, addr, sizeof(struct sockaddr_in)) < 0)
 601                         return(1);
 602         } else {
 603                 return(1);
 604         }
 605
 606         close(BROADFD);
 607         return (0);
 608 }
 609
 610 bool_t
 611 broadcast_result(bool_t *out, struct sockaddr_in *addr)
 612 {
 613         if (retries >= MAX_RETRIES) {
 614                 bzero(addr, sizeof(struct sockaddr_in));
 615                 if (tell_parent(broad_domain->dom_domain, addr))
 616                         syslog(LOG_WARNING, "lost connection to parent");
 617                 return (TRUE);
 618         }
 619
 620         if (yp_restricted && verify(addr->sin_addr)) {
 621                 retries++;
 622                 syslog(LOG_NOTICE, "NIS server at %s not in restricted mode access list -- rejecting.\n",inet_ntoa(addr->sin_addr));
 623                 return (FALSE);
 624         } else {
 625                 if (tell_parent(broad_domain->dom_domain, addr))
 626                         syslog(LOG_WARNING, "lost connection to parent");
 627                 return (TRUE);
 628         }
 629 }
 630
 631 /*
 632  * The right way to send RPC broadcasts.
 633  * Use the clnt_broadcast() RPC service. Unfortunately, clnt_broadcast()
 634  * blocks while waiting for replies, so we have to fork off separate
 635  * broadcaster processes that do the waiting and then transmit their
 636  * results back to the parent for processing. We also have to remember
 637  * to save the name of the domain we're trying to bind in a global
 638  * variable since clnt_broadcast() provides no way to pass things to
 639  * the 'eachresult' callback function.
 640  */
 641 void
 642 broadcast(struct _dom_binding *ypdb)
 643 {
 644         bool_t out = FALSE;
 645         enum clnt_stat stat;
 646
 647         if (children >= MAX_CHILDREN || ypdb->dom_broadcast_pid)
 648                 return;
 649
 650         if (pipe(ypdb->dom_pipe_fds) < 0) {
 651                 syslog(LOG_WARNING, "pipe: %m");
 652                 return;
 653         }
 654
 655         if (ypdb->dom_vers == -1 && (long)ypdb->dom_server_addr.sin_addr.s_addr)
 656                 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding",
 657                 inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain);
 658
 659         broad_domain = ypdb;
 660         flock(ypdb->dom_lockfd, LOCK_UN);
 661
 662         switch ((ypdb->dom_broadcast_pid = fork())) {
 663         case 0:
 664                 close(READFD);
 665                 signal(SIGCHLD, SIG_DFL);
 666                 signal(SIGTERM, SIG_DFL);
 667                 break;
 668         case -1:
 669                 syslog(LOG_WARNING, "fork: %m");
 670                 close(READFD);
 671                 close(WRITEFD);
 672                 return;
 673         default:
 674                 close(WRITEFD);
 675                 FD_SET(READFD, &svc_fdset);
 676                 children++;
 677                 return;
 678         }
 679
 680         /* Release all locks before doing anything else. */
 681         while (ypbindlist) {
 682                 close(ypbindlist->dom_lockfd);
 683                 ypbindlist = ypbindlist->dom_pnext;
 684         }
 685         close(yplockfd);
 686
 687         /*
 688          * Special 'many-cast' behavior. If we're in restricted mode,
 689          * we have a list of possible server addresses to try. What
 690          * we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK
 691          * procedure and time the replies. Whoever replies fastest
 692          * gets to be our server. Note that this is not a broadcast
 693          * operation: we transmit uni-cast datagrams only.
 694          */
 695         if (yp_restricted && yp_manycast) {
 696                 short                   port;
 697                 int                     i;
 698                 struct sockaddr_in      sin;
 699
 700                 i = __yp_ping(restricted_addrs, yp_restricted,
 701                                 ypdb->dom_domain, &port);
 702                 if (i == -1) {
 703                         bzero(&ypdb->dom_server_addr,
 704                             sizeof(struct sockaddr_in));
 705                         if (tell_parent(ypdb->dom_domain,
 706                             &ypdb->dom_server_addr)) {
 707                                 syslog(LOG_WARNING,
 708                                     "lost connection to parent");
 709                         }
 710                 } else {
 711                         bzero(&sin, sizeof(struct sockaddr_in));
 712                         bcopy(&restricted_addrs[i],
 713                             &sin.sin_addr, sizeof(struct in_addr));
 714                         sin.sin_family = AF_INET;
 715                         sin.sin_port = port;
 716                         if (tell_parent(broad_domain->dom_domain, &sin))
 717                                 syslog(LOG_WARNING,
 718                                         "lost connection to parent");
 719                 }
 720                 _exit(0);
 721         }
 722
 723         retries = 0;
 724
 725         {
 726                 char *ptr;
 727
 728                 ptr = ypdb->dom_domain;
 729                 stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK,
 730                         (xdrproc_t)xdr_domainname, &ptr,
 731                         (xdrproc_t)xdr_bool, &out,
 732                         (resultproc_t)broadcast_result);
 733         }
 734
 735         if (stat != RPC_SUCCESS) {
 736                 bzero(&ypdb->dom_server_addr, sizeof(struct sockaddr_in));
 737                 if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr))
 738                         syslog(LOG_WARNING, "lost connection to parent");
 739         }
 740
 741         _exit(0);
 742 }
 743
 744 /*
 745  * The right way to check if a server is alive.
 746  * Attempt to get a client handle pointing to the server and send a
 747  * YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE,
 748  * we invalidate this binding entry and send out a broadcast to try to
 749  * establish a new binding. Note that we treat non-default domains
 750  * specially: once bound, we keep tabs on our server, but if it
 751  * goes away and fails to respond after one round of broadcasting, we
 752  * abandon it until a client specifically references it again. We make
 753  * every effort to keep our default domain bound, however, since we
 754  * need it to keep the system on its feet.
 755  */
 756 int
 757 ping(struct _dom_binding *ypdb)
 758 {
 759         bool_t out;
 760         struct timeval interval, timeout;
 761         enum clnt_stat stat;
 762         int rpcsock = RPC_ANYSOCK;
 763         CLIENT *client_handle;
 764
 765         interval.tv_sec = FAIL_THRESHOLD;
 766         interval.tv_usec = 0;
 767         timeout.tv_sec = FAIL_THRESHOLD;
 768         timeout.tv_usec = 0;
 769
 770         if (ypdb->dom_broadcast_pid)
 771                 return(1);
 772
 773         if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr,
 774                 YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE,
 775                 RPCSMALLMSGSIZE)) == NULL) {
 776                 /* Can't get a handle: we're dead. */
 777                 ypdb->dom_alive = 0;
 778                 ypdb->dom_vers = -1;
 779                 broadcast(ypdb);
 780                 return(1);
 781         }
 782
 783         {
 784                 char *ptr;
 785
 786                 ptr = ypdb->dom_domain;
 787
 788                 stat = clnt_call(client_handle, YPPROC_DOMAIN,
 789                     (xdrproc_t)xdr_domainname, &ptr,
 790                     (xdrproc_t)xdr_bool, &out, timeout);
 791                 if (stat != RPC_SUCCESS || out == FALSE) {
 792                         ypdb->dom_alive = 0;
 793                         ypdb->dom_vers = -1;
 794                         clnt_destroy(client_handle);
 795                         broadcast(ypdb);
 796                         return(1);
 797                 }
 798         }
 799
 800         clnt_destroy(client_handle);
 801         return(0);
 802 }
 803
 804 void
 805 rpc_received(char *dom, struct sockaddr_in *raddrp, int force)
 806 {
 807         struct _dom_binding *ypdb, *prev = NULL;
 808         struct iovec iov[2];
 809         struct ypbind_resp ybr;
 810         char path[MAXPATHLEN];
 811         int fd;
 812
 813         /*printf("returned from %s/%d about %s\n", inet_ntoa(raddrp->sin_addr),
 814                ntohs(raddrp->sin_port), dom);*/
 815
 816         if (dom == NULL)
 817                 return;
 818
 819         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 820                 if (strcmp(ypdb->dom_domain, dom) == 0)
 821                         break;
 822                 prev = ypdb;
 823         }
 824
 825         if (ypdb && force) {
 826                 if (ypdb->dom_broadcast_pid) {
 827                         kill(ypdb->dom_broadcast_pid, SIGINT);
 828                         close(READFD);
 829                         FD_CLR(READFD, &fdsr);
 830                         FD_CLR(READFD, &svc_fdset);
 831                         READFD = WRITEFD = -1;
 832                 }
 833         }
 834
 835         /* if in secure mode, check originating port number */
 836         if ((ypsecuremode && (ntohs(raddrp->sin_port) >= IPPORT_RESERVED))) {
 837             syslog(LOG_WARNING, "Rejected NIS server on [%s/%d] for domain %s.",
 838                    inet_ntoa(raddrp->sin_addr), ntohs(raddrp->sin_port),
 839                    dom);
 840             if (ypdb != NULL) {
 841                 ypdb->dom_broadcast_pid = 0;
 842                 ypdb->dom_alive = 0;
 843             }
 844             return;
 845         }
 846
 847         if (raddrp->sin_addr.s_addr == (long)0) {
 848                 switch (ypdb->dom_default) {
 849                 case 0:
 850                         if (prev == NULL)
 851                                 ypbindlist = ypdb->dom_pnext;
 852                         else
 853                                 prev->dom_pnext = ypdb->dom_pnext;
 854                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 855                                 ypdb->dom_domain, YPVERS);
 856                         close(ypdb->dom_lockfd);
 857                         unlink(path);
 858                         free(ypdb);
 859                         domains--;
 860                         return;
 861                 case 1:
 862                         ypdb->dom_broadcast_pid = 0;
 863                         ypdb->dom_alive = 0;
 864                         broadcast(ypdb);
 865                         return;
 866                 default:
 867                         break;
 868                 }
 869         }
 870
 871         if (ypdb == NULL) {
 872                 if (force == 0)
 873                         return;
 874                 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb);
 875                 if (ypdb == NULL) {
 876                         syslog(LOG_WARNING, "malloc: %m");
 877                         return;
 878                 }
 879                 bzero(ypdb, sizeof *ypdb);
 880                 strncpy(ypdb->dom_domain, dom, sizeof ypdb->dom_domain);
 881                 ypdb->dom_lockfd = -1;
 882                 ypdb->dom_default = 0;
 883                 ypdb->dom_pnext = ypbindlist;
 884                 ypbindlist = ypdb;
 885         }
 886
 887         /* We've recovered from a crash: inform the world. */
 888         if (ypdb->dom_vers == -1 && ypdb->dom_server_addr.sin_addr.s_addr)
 889                 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" OK",
 890                 inet_ntoa(raddrp->sin_addr), ypdb->dom_domain);
 891
 892         bcopy(raddrp, &ypdb->dom_server_addr, sizeof ypdb->dom_server_addr);
 893
 894         ypdb->dom_vers = YPVERS;
 895         ypdb->dom_alive = 1;
 896         ypdb->dom_broadcast_pid = 0;
 897
 898         if (ypdb->dom_lockfd != -1)
 899                 close(ypdb->dom_lockfd);
 900
 901         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 902                 ypdb->dom_domain, ypdb->dom_vers);
 903 #ifdef O_SHLOCK
 904         if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) {
 905                 mkdir(BINDINGDIR, 0755);
 906                 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1)
 907                         return;
 908         }
 909 #else
 910         if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) {
 911                 mkdir(BINDINGDIR, 0755);
 912                 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1)
 913                         return;
 914         }
 915         flock(fd, LOCK_SH);
 916 #endif
 917
 918         /*
 919          * ok, if BINDINGDIR exists, and we can create the binding file,
 920          * then write to it..
 921          */
 922         ypdb->dom_lockfd = fd;
 923
 924         iov[0].iov_base = (char *)&(udptransp->xp_port);
 925         iov[0].iov_len = sizeof udptransp->xp_port;
 926         iov[1].iov_base = (char *)&ybr;
 927         iov[1].iov_len = sizeof ybr;
 928
 929         bzero(&ybr, sizeof ybr);
 930         ybr.ypbind_status = YPBIND_SUCC_VAL;
 931         *(u_int32_t *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = raddrp->sin_addr.s_addr;
 932         *(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = raddrp->sin_port;
 933
 934         if (writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) {
 935                 syslog(LOG_WARNING, "write: %m");
 936                 close(ypdb->dom_lockfd);
 937                 ypdb->dom_lockfd = -1;
 938                 return;
 939         }
 940 }
 941
 942 /*
 943  * Check address against list of allowed servers. Return 0 if okay,
 944  * 1 if not matched.
 945  */
 946 int
 947 verify(struct in_addr addr)
 948 {
 949         int i;
 950
 951         for (i = 0; i < RESTRICTED_SERVERS; i++)
 952                 if (!bcmp(&addr, &restricted_addrs[i], sizeof(struct in_addr)))
 953                         return(0);
 954
 955         return(1);
 956 }
 957
 958 /*
 959  * Try to set restricted mode. We default to normal mode if we can't
 960  * resolve the specified hostnames.
 961  */
 962 void
 963 yp_restricted_mode(char *args)
 964 {
 965         struct hostent *h;
 966         int i = 0;
 967         char *s;
 968
 969         /* Find the restricted domain. */
 970         if ((s = strsep(&args, ",")) == NULL)
 971                 return;
 972         domain_name = s;
 973
 974         /* Get the addresses of the servers. */
 975         while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) {
 976                 if ((h = gethostbyname(s)) == NULL)
 977                         return;
 978                 bcopy (h->h_addr_list[0], &restricted_addrs[i],
 979                     sizeof(struct in_addr));
 980                 i++;
 981         }
 982
 983         /* ypset and ypsetme not allowed with restricted mode */
 984         ypsetmode = YPSET_NO;
 985
 986         yp_restricted = i;
 987         return;
 988 }