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  * $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 #include <rpcsvc/ypclnt.h>
  65 #include "yp_ping.h"
  66
  67 #ifndef BINDINGDIR
  68 #define BINDINGDIR "/var/yp/binding"
  69 #endif
  70
  71 #ifndef YPBINDLOCK
  72 #define YPBINDLOCK "/var/run/ypbind.lock"
  73 #endif
  74
  75 struct _dom_binding {
  76         struct _dom_binding *dom_pnext;
  77         char dom_domain[YPMAXDOMAIN + 1];
  78         struct sockaddr_in dom_server_addr;
  79         long int dom_vers;
  80         int dom_lockfd;
  81         int dom_alive;
  82         int dom_broadcast_pid;
  83         int dom_pipe_fds[2];
  84         int dom_default;
  85 };
  86
  87 #define READFD ypdb->dom_pipe_fds[0]
  88 #define WRITEFD ypdb->dom_pipe_fds[1]
  89 #define BROADFD broad_domain->dom_pipe_fds[1]
  90
  91 extern bool_t xdr_domainname(), xdr_ypbind_resp();
  92 extern bool_t xdr_ypreq_key(), xdr_ypresp_val();
  93 extern bool_t xdr_ypbind_setdom();
  94
  95 void    checkwork(void);
  96 void    *ypbindproc_null_2_yp(SVCXPRT *, void *, CLIENT *);
  97 void    *ypbindproc_setdom_2_yp(SVCXPRT *, struct ypbind_setdom *, CLIENT *);
  98 void    rpc_received(char *, struct sockaddr_in *, int);
  99 void    broadcast(struct _dom_binding *);
 100 int     ping(struct _dom_binding *);
 101 int     tell_parent(char *, struct sockaddr_in *);
 102 void    handle_children(struct _dom_binding *);
 103 void    reaper(int);
 104 void    terminate(int);
 105 void    yp_restricted_mode(char *);
 106 int     verify(struct in_addr);
 107
 108 char *domain_name;
 109 struct _dom_binding *ypbindlist;
 110 static struct _dom_binding *broad_domain;
 111
 112 #define YPSET_NO        0
 113 #define YPSET_LOCAL     1
 114 #define YPSET_ALL       2
 115 int ypsetmode = YPSET_NO;
 116 int ypsecuremode = 0;
 117 int ppid;
 118
 119 /*
 120  * Special restricted mode variables: when in restricted mode, only the
 121  * specified restricted_domain will be bound, and only the servers listed
 122  * in restricted_addrs will be used for binding.
 123  */
 124 #define RESTRICTED_SERVERS 10
 125 int yp_restricted = 0;
 126 int yp_manycast = 0;
 127 struct in_addr restricted_addrs[RESTRICTED_SERVERS];
 128
 129 /* No more than MAX_CHILDREN child broadcasters at a time. */
 130 #ifndef MAX_CHILDREN
 131 #define MAX_CHILDREN 5
 132 #endif
 133 /* No more than MAX_DOMAINS simultaneous domains */
 134 #ifndef MAX_DOMAINS
 135 #define MAX_DOMAINS 200
 136 #endif
 137 /* RPC timeout value */
 138 #ifndef FAIL_THRESHOLD
 139 #define FAIL_THRESHOLD 20
 140 #endif
 141
 142 /* Number of times to fish for a response froma particular set of hosts */
 143 #ifndef MAX_RETRIES
 144 #define MAX_RETRIES 30
 145 #endif
 146
 147 int retries = 0;
 148 int children = 0;
 149 int domains = 0;
 150 int yplockfd;
 151 fd_set fdsr;
 152
 153 SVCXPRT *udptransp, *tcptransp;
 154
 155 void *
 156 ypbindproc_null_2_yp(SVCXPRT *transp, void *argp, CLIENT *clnt)
 157 {
 158         static char res;
 159
 160         bzero(&res, sizeof(res));
 161         return &res;
 162 }
 163
 164 struct ypbind_resp *
 165 ypbindproc_domain_2_yp(SVCXPRT *transp, domainname *argp, CLIENT *clnt)
 166 {
 167         static struct ypbind_resp res;
 168         struct _dom_binding *ypdb;
 169         char path[MAXPATHLEN];
 170
 171         bzero(&res, sizeof res);
 172         res.ypbind_status = YPBIND_FAIL_VAL;
 173         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_NOSERV;
 174
 175         if (strchr(*argp, '/')) {
 176                 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
 177 rejecting.", *argp);
 178                 return(&res);
 179         }
 180
 181         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 182                 if (strcmp(ypdb->dom_domain, *argp) == 0)
 183                         break;
 184                 }
 185
 186         if (ypdb == NULL) {
 187                 if (yp_restricted) {
 188                         syslog(LOG_NOTICE, "Running in restricted mode -- request to bind domain \"%s\" rejected.\n", *argp);
 189                         return (&res);
 190                 }
 191
 192                 if (domains >= MAX_DOMAINS) {
 193                         syslog(LOG_WARNING, "domain limit (%d) exceeded",
 194                                                         MAX_DOMAINS);
 195                         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
 196                         return (&res);
 197                 }
 198                 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb);
 199                 if (ypdb == NULL) {
 200                         syslog(LOG_WARNING, "malloc: %m");
 201                         res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
 202                         return (&res);
 203                 }
 204                 bzero(ypdb, sizeof *ypdb);
 205                 strncpy(ypdb->dom_domain, *argp, sizeof ypdb->dom_domain);
 206                 ypdb->dom_vers = YPVERS;
 207                 ypdb->dom_alive = 0;
 208                 ypdb->dom_default = 0;
 209                 ypdb->dom_lockfd = -1;
 210                 sprintf(path, "%s/%s.%ld", BINDINGDIR,
 211                                         ypdb->dom_domain, ypdb->dom_vers);
 212                 unlink(path);
 213                 ypdb->dom_pnext = ypbindlist;
 214                 ypbindlist = ypdb;
 215                 domains++;
 216         }
 217
 218         if (ping(ypdb)) {
 219                 return (&res);
 220         }
 221
 222         res.ypbind_status = YPBIND_SUCC_VAL;
 223         res.ypbind_resp_u.ypbind_error = 0; /* Success */
 224         *(u_int32_t *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr =
 225                 ypdb->dom_server_addr.sin_addr.s_addr;
 226         *(u_short *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port =
 227                 ypdb->dom_server_addr.sin_port;
 228         /*printf("domain %s at %s/%d\n", ypdb->dom_domain,
 229                 inet_ntoa(ypdb->dom_server_addr.sin_addr),
 230                 ntohs(ypdb->dom_server_addr.sin_port));*/
 231         return (&res);
 232 }
 233
 234 void *
 235 ypbindproc_setdom_2_yp(SVCXPRT *transp, ypbind_setdom *argp, CLIENT *clnt)
 236 {
 237         struct sockaddr_in *fromsin, bindsin;
 238         static char *result = NULL;
 239
 240         if (strchr(argp->ypsetdom_domain, '/')) {
 241                 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
 242 rejecting.", argp->ypsetdom_domain);
 243                 return(NULL);
 244         }
 245         fromsin = svc_getcaller(transp);
 246
 247         switch (ypsetmode) {
 248         case YPSET_LOCAL:
 249                 if (fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) {
 250                         svcerr_noprog(transp);
 251                         return(NULL);
 252                 }
 253                 break;
 254         case YPSET_ALL:
 255                 break;
 256         case YPSET_NO:
 257         default:
 258                 svcerr_noprog(transp);
 259                 return(NULL);
 260         }
 261
 262         if (ntohs(fromsin->sin_port) >= IPPORT_RESERVED) {
 263                 svcerr_noprog(transp);
 264                 return(NULL);
 265         }
 266
 267         if (argp->ypsetdom_vers != YPVERS) {
 268                 svcerr_noprog(transp);
 269                 return(NULL);
 270         }
 271
 272         bzero(&bindsin, sizeof bindsin);
 273         bindsin.sin_family = AF_INET;
 274         bindsin.sin_addr.s_addr = *(u_int32_t *)argp->ypsetdom_binding.ypbind_binding_addr;
 275         bindsin.sin_port = *(u_short *)argp->ypsetdom_binding.ypbind_binding_port;
 276         rpc_received(argp->ypsetdom_domain, &bindsin, 1);
 277
 278         return((void *) &result);
 279 }
 280
 281 void
 282 ypbindprog_2(struct svc_req *rqstp, SVCXPRT *transp)
 283 {
 284         union {
 285                 domainname ypbindproc_domain_2_arg;
 286                 struct ypbind_setdom ypbindproc_setdom_2_arg;
 287         } argument;
 288         struct authunix_parms *creds;
 289         char *result;
 290         bool_t (*xdr_argument)(), (*xdr_result)();
 291         char *(*local)();
 292
 293         switch (rqstp->rq_proc) {
 294         case YPBINDPROC_NULL:
 295                 xdr_argument = xdr_void;
 296                 xdr_result = xdr_void;
 297                 local = (char *(*)()) ypbindproc_null_2_yp;
 298                 break;
 299
 300         case YPBINDPROC_DOMAIN:
 301                 xdr_argument = xdr_domainname;
 302                 xdr_result = xdr_ypbind_resp;
 303                 local = (char *(*)()) ypbindproc_domain_2_yp;
 304                 break;
 305
 306         case YPBINDPROC_SETDOM:
 307                 switch (rqstp->rq_cred.oa_flavor) {
 308                 case AUTH_UNIX:
 309                         creds = (struct authunix_parms *)rqstp->rq_clntcred;
 310                         if (creds->aup_uid != 0) {
 311                                 svcerr_auth(transp, AUTH_BADCRED);
 312                                 return;
 313                         }
 314                         break;
 315                 default:
 316                         svcerr_auth(transp, AUTH_TOOWEAK);
 317                         return;
 318                 }
 319
 320                 xdr_argument = xdr_ypbind_setdom;
 321                 xdr_result = xdr_void;
 322                 local = (char *(*)()) ypbindproc_setdom_2_yp;
 323                 break;
 324
 325         default:
 326                 svcerr_noproc(transp);
 327                 return;
 328         }
 329         bzero(&argument, sizeof(argument));
 330         if (!svc_getargs(transp, (xdrproc_t)xdr_argument, &argument)) {
 331                 svcerr_decode(transp);
 332                 return;
 333         }
 334         result = (*local)(transp, &argument, rqstp);
 335         if (result != NULL &&
 336             !svc_sendreply(transp, (xdrproc_t)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]);
 405                 else if (strcmp("-m", argv[i]) == 0)
 406                         yp_manycast++;
 407                 else
 408                         errx(1, "unknown option: %s", argv[i]);
 409         }
 410
 411         /* blow away everything in BINDINGDIR (if it exists) */
 412
 413         if ((dird = opendir(BINDINGDIR)) != NULL) {
 414                 char path[MAXPATHLEN];
 415                 while ((dirp = readdir(dird)) != NULL)
 416                         if (strcmp(dirp->d_name, ".") &&
 417                             strcmp(dirp->d_name, "..")) {
 418                                 sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name);
 419                                 unlink(path);
 420                         }
 421                 closedir(dird);
 422         }
 423
 424 #ifdef DAEMON
 425         if (daemon(0,0))
 426                 err(1, "fork");
 427 #endif
 428
 429         pmap_unset(YPBINDPROG, YPBINDVERS);
 430
 431         udptransp = svcudp_create(RPC_ANYSOCK);
 432         if (udptransp == NULL)
 433                 errx(1, "cannot create udp service");
 434         if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 435             IPPROTO_UDP))
 436                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)");
 437
 438         tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0);
 439         if (tcptransp == NULL)
 440                 errx(1, "cannot create tcp service");
 441
 442         if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
 443             IPPROTO_TCP))
 444                 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)");
 445
 446         /* build initial domain binding, make it "unsuccessful" */
 447         ypbindlist = (struct _dom_binding *)malloc(sizeof *ypbindlist);
 448         if (ypbindlist == NULL)
 449                 errx(1, "malloc");
 450         bzero(ypbindlist, sizeof *ypbindlist);
 451         strncpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain);
 452         ypbindlist->dom_vers = YPVERS;
 453         ypbindlist->dom_alive = 0;
 454         ypbindlist->dom_lockfd = -1;
 455         ypbindlist->dom_default = 1;
 456         domains++;
 457
 458         signal(SIGCHLD, reaper);
 459         signal(SIGTERM, terminate);
 460
 461         ppid = getpid(); /* Remember who we are. */
 462
 463         openlog(argv[0], LOG_PID, LOG_DAEMON);
 464
 465         /* Kick off the default domain */
 466         broadcast(ypbindlist);
 467
 468         while (1) {
 469                 fdsr = svc_fdset;
 470
 471                 tv.tv_sec = 60;
 472                 tv.tv_usec = 0;
 473
 474                 switch (select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) {
 475                 case 0:
 476                         checkwork();
 477                         break;
 478                 case -1:
 479                         if (errno != EINTR)
 480                                 syslog(LOG_WARNING, "select: %m");
 481                         break;
 482                 default:
 483                         for (ypdb = ypbindlist; ypdb; ypdb = next) {
 484                                 next = ypdb->dom_pnext;
 485                                 if (READFD > 0 && FD_ISSET(READFD, &fdsr)) {
 486                                         handle_children(ypdb);
 487                                         if (children == (MAX_CHILDREN - 1))
 488                                                 checkwork();
 489                                 }
 490                         }
 491                         svc_getreqset(&fdsr);
 492                         break;
 493                 }
 494         }
 495
 496         /* NOTREACHED */
 497         exit(1);
 498 }
 499
 500 void
 501 checkwork(void)
 502 {
 503         struct _dom_binding *ypdb;
 504
 505         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
 506                 ping(ypdb);
 507 }
 508
 509 /* The clnt_broadcast() callback mechanism sucks. */
 510
 511 /*
 512  * Receive results from broadcaster. Don't worry about passing
 513  * bogus info to rpc_received() -- it can handle it. Note that we
 514  * must be sure to invalidate the dom_pipe_fds descriptors here:
 515  * since descriptors can be re-used, we have to make sure we
 516  * don't mistake one of the RPC descriptors for one of the pipes.
 517  * What's weird is that forgetting to invalidate the pipe descriptors
 518  * doesn't always result in an error (otherwise I would have caught
 519  * the mistake much sooner), even though logically it should.
 520  */
 521 void
 522 handle_children(struct _dom_binding *ypdb)
 523 {
 524         char buf[YPMAXDOMAIN + 1];
 525         struct sockaddr_in addr;
 526         int d = 0, a = 0;
 527         struct _dom_binding *y, *prev = NULL;
 528         char path[MAXPATHLEN];
 529
 530         if ((d = read(READFD, &buf, sizeof(buf))) <= 0)
 531                 syslog(LOG_WARNING, "could not read from child: %m");
 532
 533         if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0)
 534                 syslog(LOG_WARNING, "could not read from child: %m");
 535
 536         close(READFD);
 537         FD_CLR(READFD, &fdsr);
 538         FD_CLR(READFD, &svc_fdset);
 539         READFD = WRITEFD = -1;
 540         if (d > 0 && a > 0)
 541                 rpc_received(buf, &addr, 0);
 542         else {
 543                 for (y = ypbindlist; y; y = y->dom_pnext) {
 544                         if (y == ypdb)
 545                                 break;
 546                         prev = y;
 547                 }
 548                 switch (ypdb->dom_default) {
 549                 case 0:
 550                         if (prev == NULL)
 551                                 ypbindlist = y->dom_pnext;
 552                         else
 553                                 prev->dom_pnext = y->dom_pnext;
 554                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 555                                 ypdb->dom_domain, YPVERS);
 556                         close(ypdb->dom_lockfd);
 557                         unlink(path);
 558                         free(ypdb);
 559                         domains--;
 560                         return;
 561                 case 1:
 562                         ypdb->dom_broadcast_pid = 0;
 563                         ypdb->dom_alive = 0;
 564                         broadcast(ypdb);
 565                         return;
 566                 default:
 567                         break;
 568                 }
 569         }
 570
 571         return;
 572 }
 573
 574 /*
 575  * Send our dying words back to our parent before we perish.
 576  */
 577 int
 578 tell_parent(char *dom, struct sockaddr_in *addr)
 579 {
 580         char buf[YPMAXDOMAIN + 1];
 581         struct timeval timeout;
 582         fd_set fds;
 583
 584         timeout.tv_sec = 5;
 585         timeout.tv_usec = 0;
 586
 587         sprintf(buf, "%s", broad_domain->dom_domain);
 588         if (write(BROADFD, &buf, sizeof(buf)) < 0)
 589                 return(1);
 590
 591         /*
 592          * Stay in sync with parent: wait for it to read our first
 593          * message before sending the second.
 594          */
 595
 596         FD_ZERO(&fds);
 597         FD_SET(BROADFD, &fds);
 598         if (select(FD_SETSIZE, NULL, &fds, NULL, &timeout) == -1)
 599                 return(1);
 600         if (FD_ISSET(BROADFD, &fds)) {
 601                 if (write(BROADFD, addr, sizeof(struct sockaddr_in)) < 0)
 602                         return(1);
 603         } else {
 604                 return(1);
 605         }
 606
 607         close(BROADFD);
 608         return (0);
 609 }
 610
 611 bool_t
 612 broadcast_result(bool_t *out, struct sockaddr_in *addr)
 613 {
 614         if (retries >= MAX_RETRIES) {
 615                 bzero(addr, sizeof(struct sockaddr_in));
 616                 if (tell_parent(broad_domain->dom_domain, addr))
 617                         syslog(LOG_WARNING, "lost connection to parent");
 618                 return (TRUE);
 619         }
 620
 621         if (yp_restricted && verify(addr->sin_addr)) {
 622                 retries++;
 623                 syslog(LOG_NOTICE, "NIS server at %s not in restricted mode access list -- rejecting.\n",inet_ntoa(addr->sin_addr));
 624                 return (FALSE);
 625         } else {
 626                 if (tell_parent(broad_domain->dom_domain, addr))
 627                         syslog(LOG_WARNING, "lost connection to parent");
 628                 return (TRUE);
 629         }
 630 }
 631
 632 /*
 633  * The right way to send RPC broadcasts.
 634  * Use the clnt_broadcast() RPC service. Unfortunately, clnt_broadcast()
 635  * blocks while waiting for replies, so we have to fork off separate
 636  * broadcaster processes that do the waiting and then transmit their
 637  * results back to the parent for processing. We also have to remember
 638  * to save the name of the domain we're trying to bind in a global
 639  * variable since clnt_broadcast() provides no way to pass things to
 640  * the 'eachresult' callback function.
 641  */
 642 void
 643 broadcast(struct _dom_binding *ypdb)
 644 {
 645         bool_t out = FALSE;
 646         enum clnt_stat stat;
 647
 648         if (children >= MAX_CHILDREN || ypdb->dom_broadcast_pid)
 649                 return;
 650
 651         if (pipe(ypdb->dom_pipe_fds) < 0) {
 652                 syslog(LOG_WARNING, "pipe: %m");
 653                 return;
 654         }
 655
 656         if (ypdb->dom_vers == -1 && (long)ypdb->dom_server_addr.sin_addr.s_addr)
 657                 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding",
 658                 inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain);
 659
 660         broad_domain = ypdb;
 661         flock(ypdb->dom_lockfd, LOCK_UN);
 662
 663         switch ((ypdb->dom_broadcast_pid = fork())) {
 664         case 0:
 665                 close(READFD);
 666                 signal(SIGCHLD, SIG_DFL);
 667                 signal(SIGTERM, SIG_DFL);
 668                 break;
 669         case -1:
 670                 syslog(LOG_WARNING, "fork: %m");
 671                 close(READFD);
 672                 close(WRITEFD);
 673                 return;
 674         default:
 675                 close(WRITEFD);
 676                 FD_SET(READFD, &svc_fdset);
 677                 children++;
 678                 return;
 679         }
 680
 681         /* Release all locks before doing anything else. */
 682         while (ypbindlist) {
 683                 close(ypbindlist->dom_lockfd);
 684                 ypbindlist = ypbindlist->dom_pnext;
 685         }
 686         close(yplockfd);
 687
 688         /*
 689          * Special 'many-cast' behavior. If we're in restricted mode,
 690          * we have a list of possible server addresses to try. What
 691          * we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK
 692          * procedure and time the replies. Whoever replies fastest
 693          * gets to be our server. Note that this is not a broadcast
 694          * operation: we transmit uni-cast datagrams only.
 695          */
 696         if (yp_restricted && yp_manycast) {
 697                 short                   port;
 698                 int                     i;
 699                 struct sockaddr_in      sin;
 700
 701                 i = __yp_ping(restricted_addrs, yp_restricted,
 702                                 ypdb->dom_domain, &port);
 703                 if (i == -1) {
 704                         bzero(&ypdb->dom_server_addr,
 705                             sizeof(struct sockaddr_in));
 706                         if (tell_parent(ypdb->dom_domain,
 707                             &ypdb->dom_server_addr)) {
 708                                 syslog(LOG_WARNING,
 709                                     "lost connection to parent");
 710                         }
 711                 } else {
 712                         bzero(&sin, sizeof(struct sockaddr_in));
 713                         bcopy(&restricted_addrs[i],
 714                             &sin.sin_addr, sizeof(struct in_addr));
 715                         sin.sin_family = AF_INET;
 716                         sin.sin_port = port;
 717                         if (tell_parent(broad_domain->dom_domain, &sin))
 718                                 syslog(LOG_WARNING,
 719                                         "lost connection to parent");
 720                 }
 721                 _exit(0);
 722         }
 723
 724         retries = 0;
 725
 726         {
 727                 char *ptr;
 728
 729                 ptr = ypdb->dom_domain;
 730                 stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK,
 731                         (xdrproc_t)xdr_domainname, &ptr,
 732                         (xdrproc_t)xdr_bool, &out,
 733                         (resultproc_t)broadcast_result);
 734         }
 735
 736         if (stat != RPC_SUCCESS) {
 737                 bzero(&ypdb->dom_server_addr, sizeof(struct sockaddr_in));
 738                 if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr))
 739                         syslog(LOG_WARNING, "lost connection to parent");
 740         }
 741
 742         _exit(0);
 743 }
 744
 745 /*
 746  * The right way to check if a server is alive.
 747  * Attempt to get a client handle pointing to the server and send a
 748  * YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE,
 749  * we invalidate this binding entry and send out a broadcast to try to
 750  * establish a new binding. Note that we treat non-default domains
 751  * specially: once bound, we keep tabs on our server, but if it
 752  * goes away and fails to respond after one round of broadcasting, we
 753  * abandon it until a client specifically references it again. We make
 754  * every effort to keep our default domain bound, however, since we
 755  * need it to keep the system on its feet.
 756  */
 757 int
 758 ping(struct _dom_binding *ypdb)
 759 {
 760         bool_t out;
 761         struct timeval interval, timeout;
 762         enum clnt_stat stat;
 763         int rpcsock = RPC_ANYSOCK;
 764         CLIENT *client_handle;
 765
 766         interval.tv_sec = FAIL_THRESHOLD;
 767         interval.tv_usec = 0;
 768         timeout.tv_sec = FAIL_THRESHOLD;
 769         timeout.tv_usec = 0;
 770
 771         if (ypdb->dom_broadcast_pid)
 772                 return(1);
 773
 774         if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr,
 775                 YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE,
 776                 RPCSMALLMSGSIZE)) == NULL) {
 777                 /* Can't get a handle: we're dead. */
 778                 ypdb->dom_alive = 0;
 779                 ypdb->dom_vers = -1;
 780                 broadcast(ypdb);
 781                 return(1);
 782         }
 783
 784         {
 785                 char *ptr;
 786
 787                 ptr = ypdb->dom_domain;
 788
 789                 stat = clnt_call(client_handle, YPPROC_DOMAIN,
 790                     (xdrproc_t)xdr_domainname, &ptr,
 791                     (xdrproc_t)xdr_bool, &out, timeout);
 792                 if (stat != RPC_SUCCESS || out == FALSE) {
 793                         ypdb->dom_alive = 0;
 794                         ypdb->dom_vers = -1;
 795                         clnt_destroy(client_handle);
 796                         broadcast(ypdb);
 797                         return(1);
 798                 }
 799         }
 800
 801         clnt_destroy(client_handle);
 802         return(0);
 803 }
 804
 805 void
 806 rpc_received(char *dom, struct sockaddr_in *raddrp, int force)
 807 {
 808         struct _dom_binding *ypdb, *prev = NULL;
 809         struct iovec iov[2];
 810         struct ypbind_resp ybr;
 811         char path[MAXPATHLEN];
 812         int fd;
 813
 814         /*printf("returned from %s/%d about %s\n", inet_ntoa(raddrp->sin_addr),
 815                ntohs(raddrp->sin_port), dom);*/
 816
 817         if (dom == NULL)
 818                 return;
 819
 820         for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
 821                 if (strcmp(ypdb->dom_domain, dom) == 0)
 822                         break;
 823                 prev = ypdb;
 824         }
 825
 826         if (ypdb && force) {
 827                 if (ypdb->dom_broadcast_pid) {
 828                         kill(ypdb->dom_broadcast_pid, SIGINT);
 829                         close(READFD);
 830                         FD_CLR(READFD, &fdsr);
 831                         FD_CLR(READFD, &svc_fdset);
 832                         READFD = WRITEFD = -1;
 833                 }
 834         }
 835
 836         /* if in secure mode, check originating port number */
 837         if ((ypsecuremode && (ntohs(raddrp->sin_port) >= IPPORT_RESERVED))) {
 838             syslog(LOG_WARNING, "Rejected NIS server on [%s/%d] for domain %s.",
 839                    inet_ntoa(raddrp->sin_addr), ntohs(raddrp->sin_port),
 840                    dom);
 841             if (ypdb != NULL) {
 842                 ypdb->dom_broadcast_pid = 0;
 843                 ypdb->dom_alive = 0;
 844             }
 845             return;
 846         }
 847
 848         if (raddrp->sin_addr.s_addr == (long)0) {
 849                 switch (ypdb->dom_default) {
 850                 case 0:
 851                         if (prev == NULL)
 852                                 ypbindlist = ypdb->dom_pnext;
 853                         else
 854                                 prev->dom_pnext = ypdb->dom_pnext;
 855                         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 856                                 ypdb->dom_domain, YPVERS);
 857                         close(ypdb->dom_lockfd);
 858                         unlink(path);
 859                         free(ypdb);
 860                         domains--;
 861                         return;
 862                 case 1:
 863                         ypdb->dom_broadcast_pid = 0;
 864                         ypdb->dom_alive = 0;
 865                         broadcast(ypdb);
 866                         return;
 867                 default:
 868                         break;
 869                 }
 870         }
 871
 872         if (ypdb == NULL) {
 873                 if (force == 0)
 874                         return;
 875                 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb);
 876                 if (ypdb == NULL) {
 877                         syslog(LOG_WARNING, "malloc: %m");
 878                         return;
 879                 }
 880                 bzero(ypdb, sizeof *ypdb);
 881                 strncpy(ypdb->dom_domain, dom, sizeof ypdb->dom_domain);
 882                 ypdb->dom_lockfd = -1;
 883                 ypdb->dom_default = 0;
 884                 ypdb->dom_pnext = ypbindlist;
 885                 ypbindlist = ypdb;
 886         }
 887
 888         /* We've recovered from a crash: inform the world. */
 889         if (ypdb->dom_vers == -1 && ypdb->dom_server_addr.sin_addr.s_addr)
 890                 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" OK",
 891                 inet_ntoa(raddrp->sin_addr), ypdb->dom_domain);
 892
 893         bcopy(raddrp, &ypdb->dom_server_addr, sizeof ypdb->dom_server_addr);
 894
 895         ypdb->dom_vers = YPVERS;
 896         ypdb->dom_alive = 1;
 897         ypdb->dom_broadcast_pid = 0;
 898
 899         if (ypdb->dom_lockfd != -1)
 900                 close(ypdb->dom_lockfd);
 901
 902         sprintf(path, "%s/%s.%ld", BINDINGDIR,
 903                 ypdb->dom_domain, ypdb->dom_vers);
 904 #ifdef O_SHLOCK
 905         if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) {
 906                 mkdir(BINDINGDIR, 0755);
 907                 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1)
 908                         return;
 909         }
 910 #else
 911         if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) {
 912                 mkdir(BINDINGDIR, 0755);
 913                 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1)
 914                         return;
 915         }
 916         flock(fd, LOCK_SH);
 917 #endif
 918
 919         /*
 920          * ok, if BINDINGDIR exists, and we can create the binding file,
 921          * then write to it..
 922          */
 923         ypdb->dom_lockfd = fd;
 924
 925         iov[0].iov_base = (char *)&(udptransp->xp_port);
 926         iov[0].iov_len = sizeof udptransp->xp_port;
 927         iov[1].iov_base = (char *)&ybr;
 928         iov[1].iov_len = sizeof ybr;
 929
 930         bzero(&ybr, sizeof ybr);
 931         ybr.ypbind_status = YPBIND_SUCC_VAL;
 932         *(u_int32_t *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = raddrp->sin_addr.s_addr;
 933         *(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = raddrp->sin_port;
 934
 935         if (writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) {
 936                 syslog(LOG_WARNING, "write: %m");
 937                 close(ypdb->dom_lockfd);
 938                 ypdb->dom_lockfd = -1;
 939                 return;
 940         }
 941 }
 942
 943 /*
 944  * Check address against list of allowed servers. Return 0 if okay,
 945  * 1 if not matched.
 946  */
 947 int
 948 verify(struct in_addr addr)
 949 {
 950         int i;
 951
 952         for (i = 0; i < RESTRICTED_SERVERS; i++)
 953                 if (!bcmp(&addr, &restricted_addrs[i], sizeof(struct in_addr)))
 954                         return(0);
 955
 956         return(1);
 957 }
 958
 959 /*
 960  * Try to set restricted mode. We default to normal mode if we can't
 961  * resolve the specified hostnames.
 962  */
 963 void
 964 yp_restricted_mode(char *args)
 965 {
 966         struct hostent *h;
 967         int i = 0;
 968         char *s;
 969
 970         /* Find the restricted domain. */
 971         if ((s = strsep(&args, ",")) == NULL)
 972                 return;
 973         domain_name = s;
 974
 975         /* Get the addresses of the servers. */
 976         while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) {
 977                 if ((h = gethostbyname(s)) == NULL)
 978                         return;
 979                 bcopy (h->h_addr_list[0], &restricted_addrs[i],
 980                     sizeof(struct in_addr));
 981                 i++;
 982         }
 983
 984         /* ypset and ypsetme not allowed with restricted mode */
 985         ypsetmode = YPSET_NO;
 986
 987         yp_restricted = i;
 988         return;
 989 }