1 /* 2 * Copyright (c) 1992/3 Theo de Raadt <deraadt@fsa.ca> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote 14 * products derived from this software without specific prior written 15 * permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 18 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 #include <sys/types.h> 35 #include <sys/wait.h> 36 #include <sys/ioctl.h> 37 #include <sys/mman.h> 38 #include <sys/signal.h> 39 #include <sys/socket.h> 40 #include <sys/file.h> 41 #include <sys/fcntl.h> 42 #include <sys/stat.h> 43 #include <sys/uio.h> 44 #include <ctype.h> 45 #include <dirent.h> 46 #include <err.h> 47 #include <errno.h> 48 #include <netdb.h> 49 #include <signal.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <syslog.h> 54 #include <unistd.h> 55 #include <rpc/rpc.h> 56 #include <rpc/xdr.h> 57 #include <net/if.h> 58 #include <netinet/in.h> 59 #include <arpa/inet.h> 60 #include <rpc/pmap_clnt.h> 61 #include <rpc/pmap_prot.h> 62 #include <rpc/pmap_rmt.h> 63 #include <rpc/rpc_com.h> 64 #include <rpcsvc/yp.h> 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 #define NOT_RESPONDING_HYSTERESIS 10 121 static int not_responding_count = 0; 122 123 /* 124 * Special restricted mode variables: when in restricted mode, only the 125 * specified restricted_domain will be bound, and only the servers listed 126 * in restricted_addrs will be used for binding. 127 */ 128 #define RESTRICTED_SERVERS 10 129 int yp_restricted = 0; 130 int yp_manycast = 0; 131 struct in_addr restricted_addrs[RESTRICTED_SERVERS]; 132 133 /* No more than MAX_CHILDREN child broadcasters at a time. */ 134 #ifndef MAX_CHILDREN 135 #define MAX_CHILDREN 5 136 #endif 137 /* No more than MAX_DOMAINS simultaneous domains */ 138 #ifndef MAX_DOMAINS 139 #define MAX_DOMAINS 200 140 #endif 141 /* RPC timeout value */ 142 #ifndef FAIL_THRESHOLD 143 #define FAIL_THRESHOLD 20 144 #endif 145 146 /* Number of times to fish for a response froma particular set of hosts */ 147 #ifndef MAX_RETRIES 148 #define MAX_RETRIES 30 149 #endif 150 151 int retries = 0; 152 int children = 0; 153 int domains = 0; 154 int yplockfd; 155 fd_set fdsr; 156 157 SVCXPRT *udptransp, *tcptransp; 158 159 void * 160 ypbindproc_null_2_yp(SVCXPRT *transp, void *argp, CLIENT *clnt) 161 { 162 static char res; 163 164 bzero(&res, sizeof(res)); 165 return &res; 166 } 167 168 struct ypbind_resp * 169 ypbindproc_domain_2_yp(SVCXPRT *transp, domainname *argp, CLIENT *clnt) 170 { 171 static struct ypbind_resp res; 172 struct _dom_binding *ypdb; 173 char path[MAXPATHLEN]; 174 175 bzero(&res, sizeof res); 176 res.ypbind_status = YPBIND_FAIL_VAL; 177 res.ypbind_resp_u.ypbind_error = YPBIND_ERR_NOSERV; 178 179 if (strchr(*argp, '/')) { 180 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \ 181 rejecting.", *argp); 182 return(&res); 183 } 184 185 for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) { 186 if (strcmp(ypdb->dom_domain, *argp) == 0) 187 break; 188 } 189 190 if (ypdb == NULL) { 191 if (yp_restricted) { 192 syslog(LOG_NOTICE, "Running in restricted mode -- request to bind domain \"%s\" rejected.\n", *argp); 193 return (&res); 194 } 195 196 if (domains >= MAX_DOMAINS) { 197 syslog(LOG_WARNING, "domain limit (%d) exceeded", 198 MAX_DOMAINS); 199 res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC; 200 return (&res); 201 } 202 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb); 203 if (ypdb == NULL) { 204 syslog(LOG_WARNING, "malloc: %m"); 205 res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC; 206 return (&res); 207 } 208 bzero(ypdb, sizeof *ypdb); 209 strncpy(ypdb->dom_domain, *argp, sizeof ypdb->dom_domain); 210 ypdb->dom_vers = YPVERS; 211 ypdb->dom_alive = 0; 212 ypdb->dom_default = 0; 213 ypdb->dom_lockfd = -1; 214 sprintf(path, "%s/%s.%ld", BINDINGDIR, 215 ypdb->dom_domain, ypdb->dom_vers); 216 unlink(path); 217 ypdb->dom_pnext = ypbindlist; 218 ypbindlist = ypdb; 219 domains++; 220 } 221 222 if (ping(ypdb)) { 223 return (&res); 224 } 225 226 res.ypbind_status = YPBIND_SUCC_VAL; 227 res.ypbind_resp_u.ypbind_error = 0; /* Success */ 228 *(u_int32_t *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = 229 ypdb->dom_server_addr.sin_addr.s_addr; 230 *(u_short *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = 231 ypdb->dom_server_addr.sin_port; 232 /*printf("domain %s at %s/%d\n", ypdb->dom_domain, 233 inet_ntoa(ypdb->dom_server_addr.sin_addr), 234 ntohs(ypdb->dom_server_addr.sin_port));*/ 235 return (&res); 236 } 237 238 void * 239 ypbindproc_setdom_2_yp(SVCXPRT *transp, ypbind_setdom *argp, CLIENT *clnt) 240 { 241 struct sockaddr_in *fromsin, bindsin; 242 static char *result = NULL; 243 244 if (strchr(argp->ypsetdom_domain, '/')) { 245 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \ 246 rejecting.", argp->ypsetdom_domain); 247 return(NULL); 248 } 249 fromsin = svc_getcaller(transp); 250 251 switch (ypsetmode) { 252 case YPSET_LOCAL: 253 if (fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) { 254 svcerr_noprog(transp); 255 return(NULL); 256 } 257 break; 258 case YPSET_ALL: 259 break; 260 case YPSET_NO: 261 default: 262 svcerr_noprog(transp); 263 return(NULL); 264 } 265 266 if (ntohs(fromsin->sin_port) >= IPPORT_RESERVED) { 267 svcerr_noprog(transp); 268 return(NULL); 269 } 270 271 if (argp->ypsetdom_vers != YPVERS) { 272 svcerr_noprog(transp); 273 return(NULL); 274 } 275 276 bzero(&bindsin, sizeof bindsin); 277 bindsin.sin_family = AF_INET; 278 bindsin.sin_addr.s_addr = *(u_int32_t *)argp->ypsetdom_binding.ypbind_binding_addr; 279 bindsin.sin_port = *(u_short *)argp->ypsetdom_binding.ypbind_binding_port; 280 rpc_received(argp->ypsetdom_domain, &bindsin, 1); 281 282 return((void *) &result); 283 } 284 285 void 286 ypbindprog_2(struct svc_req *rqstp, register SVCXPRT *transp) 287 { 288 union { 289 domainname ypbindproc_domain_2_arg; 290 struct ypbind_setdom ypbindproc_setdom_2_arg; 291 } argument; 292 struct authunix_parms *creds; 293 char *result; 294 bool_t (*xdr_argument)(), (*xdr_result)(); 295 char *(*local)(); 296 297 switch (rqstp->rq_proc) { 298 case YPBINDPROC_NULL: 299 xdr_argument = xdr_void; 300 xdr_result = xdr_void; 301 local = (char *(*)()) ypbindproc_null_2_yp; 302 break; 303 304 case YPBINDPROC_DOMAIN: 305 xdr_argument = xdr_domainname; 306 xdr_result = xdr_ypbind_resp; 307 local = (char *(*)()) ypbindproc_domain_2_yp; 308 break; 309 310 case YPBINDPROC_SETDOM: 311 switch (rqstp->rq_cred.oa_flavor) { 312 case AUTH_UNIX: 313 creds = (struct authunix_parms *)rqstp->rq_clntcred; 314 if (creds->aup_uid != 0) { 315 svcerr_auth(transp, AUTH_BADCRED); 316 return; 317 } 318 break; 319 default: 320 svcerr_auth(transp, AUTH_TOOWEAK); 321 return; 322 } 323 324 xdr_argument = xdr_ypbind_setdom; 325 xdr_result = xdr_void; 326 local = (char *(*)()) ypbindproc_setdom_2_yp; 327 break; 328 329 default: 330 svcerr_noproc(transp); 331 return; 332 } 333 bzero(&argument, sizeof(argument)); 334 if (!svc_getargs(transp, (xdrproc_t)xdr_argument, &argument)) { 335 svcerr_decode(transp); 336 return; 337 } 338 result = (*local)(transp, &argument, rqstp); 339 if (result != NULL && 340 !svc_sendreply(transp, (xdrproc_t)xdr_result, result)) { 341 svcerr_systemerr(transp); 342 } 343 return; 344 } 345 346 /* Jack the reaper */ 347 void 348 reaper(int sig) 349 { 350 int st; 351 352 while (wait3(&st, WNOHANG, NULL) > 0) 353 children--; 354 } 355 356 void 357 terminate(int sig) 358 { 359 struct _dom_binding *ypdb; 360 char path[MAXPATHLEN]; 361 362 if (ppid != getpid()) 363 exit(0); 364 365 for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) { 366 close(ypdb->dom_lockfd); 367 if (ypdb->dom_broadcast_pid) 368 kill(ypdb->dom_broadcast_pid, SIGINT); 369 sprintf(path, "%s/%s.%ld", BINDINGDIR, 370 ypdb->dom_domain, ypdb->dom_vers); 371 unlink(path); 372 } 373 close(yplockfd); 374 unlink(YPBINDLOCK); 375 pmap_unset(YPBINDPROG, YPBINDVERS); 376 exit(0); 377 } 378 379 int 380 main(int argc, char *argv[]) 381 { 382 struct timeval tv; 383 int i; 384 DIR *dird; 385 struct dirent *dirp; 386 struct _dom_binding *ypdb, *next; 387 388 /* Check that another ypbind isn't already running. */ 389 if ((yplockfd = (open(YPBINDLOCK, O_RDONLY|O_CREAT, 0444))) == -1) 390 err(1, "%s", YPBINDLOCK); 391 392 if (flock(yplockfd, LOCK_EX|LOCK_NB) == -1 && errno == EWOULDBLOCK) 393 errx(1, "another ypbind is already running. Aborting"); 394 395 /* XXX domainname will be overriden if we use restricted mode */ 396 yp_get_default_domain(&domain_name); 397 if (domain_name[0] == '\0') 398 errx(1, "domainname not set. Aborting"); 399 400 for (i = 1; i<argc; i++) { 401 if (strcmp("-ypset", argv[i]) == 0) 402 ypsetmode = YPSET_ALL; 403 else if (strcmp("-ypsetme", argv[i]) == 0) 404 ypsetmode = YPSET_LOCAL; 405 else if (strcmp("-s", argv[i]) == 0) 406 ypsecuremode++; 407 else if (strcmp("-S", argv[i]) == 0 && argc > i) 408 yp_restricted_mode(argv[++i]); 409 else if (strcmp("-m", argv[i]) == 0) 410 yp_manycast++; 411 else 412 errx(1, "unknown option: %s", argv[i]); 413 } 414 415 /* blow away everything in BINDINGDIR (if it exists) */ 416 417 if ((dird = opendir(BINDINGDIR)) != NULL) { 418 char path[MAXPATHLEN]; 419 while ((dirp = readdir(dird)) != NULL) 420 if (strcmp(dirp->d_name, ".") && 421 strcmp(dirp->d_name, "..")) { 422 sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name); 423 unlink(path); 424 } 425 closedir(dird); 426 } 427 428 #ifdef DAEMON 429 if (daemon(0,0)) 430 err(1, "fork"); 431 #endif 432 433 pmap_unset(YPBINDPROG, YPBINDVERS); 434 435 udptransp = svcudp_create(RPC_ANYSOCK); 436 if (udptransp == NULL) 437 errx(1, "cannot create udp service"); 438 if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2, 439 IPPROTO_UDP)) 440 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)"); 441 442 tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0); 443 if (tcptransp == NULL) 444 errx(1, "cannot create tcp service"); 445 446 if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2, 447 IPPROTO_TCP)) 448 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)"); 449 450 /* build initial domain binding, make it "unsuccessful" */ 451 ypbindlist = (struct _dom_binding *)malloc(sizeof *ypbindlist); 452 if (ypbindlist == NULL) 453 errx(1, "malloc"); 454 bzero(ypbindlist, sizeof *ypbindlist); 455 strncpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain); 456 ypbindlist->dom_vers = YPVERS; 457 ypbindlist->dom_alive = 0; 458 ypbindlist->dom_lockfd = -1; 459 ypbindlist->dom_default = 1; 460 domains++; 461 462 signal(SIGCHLD, reaper); 463 signal(SIGTERM, terminate); 464 465 ppid = getpid(); /* Remember who we are. */ 466 467 openlog(argv[0], LOG_PID, LOG_DAEMON); 468 469 if (madvise(NULL, 0, MADV_PROTECT) != 0) 470 syslog(LOG_WARNING, "madvise(): %m"); 471 472 /* Kick off the default domain */ 473 broadcast(ypbindlist); 474 475 while (1) { 476 fdsr = svc_fdset; 477 478 tv.tv_sec = 60; 479 tv.tv_usec = 0; 480 481 switch (select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) { 482 case 0: 483 checkwork(); 484 break; 485 case -1: 486 if (errno != EINTR) 487 syslog(LOG_WARNING, "select: %m"); 488 break; 489 default: 490 for (ypdb = ypbindlist; ypdb; ypdb = next) { 491 next = ypdb->dom_pnext; 492 if (READFD > 0 && FD_ISSET(READFD, &fdsr)) { 493 handle_children(ypdb); 494 if (children == (MAX_CHILDREN - 1)) 495 checkwork(); 496 } 497 } 498 svc_getreqset(&fdsr); 499 break; 500 } 501 } 502 503 /* NOTREACHED */ 504 exit(1); 505 } 506 507 void 508 checkwork(void) 509 { 510 struct _dom_binding *ypdb; 511 512 for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) 513 ping(ypdb); 514 } 515 516 /* The clnt_broadcast() callback mechanism sucks. */ 517 518 /* 519 * Receive results from broadcaster. Don't worry about passing 520 * bogus info to rpc_received() -- it can handle it. Note that we 521 * must be sure to invalidate the dom_pipe_fds descriptors here: 522 * since descriptors can be re-used, we have to make sure we 523 * don't mistake one of the RPC descriptors for one of the pipes. 524 * What's weird is that forgetting to invalidate the pipe descriptors 525 * doesn't always result in an error (otherwise I would have caught 526 * the mistake much sooner), even though logically it should. 527 */ 528 void 529 handle_children(struct _dom_binding *ypdb) 530 { 531 char buf[YPMAXDOMAIN + 1]; 532 struct sockaddr_in addr; 533 int d = 0, a = 0; 534 struct _dom_binding *y, *prev = NULL; 535 char path[MAXPATHLEN]; 536 537 if ((d = read(READFD, &buf, sizeof(buf))) <= 0) 538 syslog(LOG_WARNING, "could not read from child: %m"); 539 540 if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0) 541 syslog(LOG_WARNING, "could not read from child: %m"); 542 543 close(READFD); 544 FD_CLR(READFD, &fdsr); 545 FD_CLR(READFD, &svc_fdset); 546 READFD = WRITEFD = -1; 547 if (d > 0 && a > 0) 548 rpc_received(buf, &addr, 0); 549 else { 550 for (y = ypbindlist; y; y = y->dom_pnext) { 551 if (y == ypdb) 552 break; 553 prev = y; 554 } 555 switch (ypdb->dom_default) { 556 case 0: 557 if (prev == NULL) 558 ypbindlist = y->dom_pnext; 559 else 560 prev->dom_pnext = y->dom_pnext; 561 sprintf(path, "%s/%s.%ld", BINDINGDIR, 562 ypdb->dom_domain, YPVERS); 563 close(ypdb->dom_lockfd); 564 unlink(path); 565 free(ypdb); 566 domains--; 567 return; 568 case 1: 569 ypdb->dom_broadcast_pid = 0; 570 ypdb->dom_alive = 0; 571 broadcast(ypdb); 572 return; 573 default: 574 break; 575 } 576 } 577 578 return; 579 } 580 581 /* 582 * Send our dying words back to our parent before we perish. 583 */ 584 int 585 tell_parent(char *dom, struct sockaddr_in *addr) 586 { 587 char buf[YPMAXDOMAIN + 1]; 588 struct timeval timeout; 589 fd_set fds; 590 591 timeout.tv_sec = 5; 592 timeout.tv_usec = 0; 593 594 sprintf(buf, "%s", broad_domain->dom_domain); 595 if (write(BROADFD, &buf, sizeof(buf)) < 0) 596 return(1); 597 598 /* 599 * Stay in sync with parent: wait for it to read our first 600 * message before sending the second. 601 */ 602 603 FD_ZERO(&fds); 604 FD_SET(BROADFD, &fds); 605 if (select(FD_SETSIZE, NULL, &fds, NULL, &timeout) == -1) 606 return(1); 607 if (FD_ISSET(BROADFD, &fds)) { 608 if (write(BROADFD, addr, sizeof(struct sockaddr_in)) < 0) 609 return(1); 610 } else { 611 return(1); 612 } 613 614 close(BROADFD); 615 return (0); 616 } 617 618 bool_t broadcast_result(out, addr) 619 bool_t *out; 620 struct sockaddr_in *addr; 621 { 622 if (retries >= MAX_RETRIES) { 623 bzero(addr, sizeof(struct sockaddr_in)); 624 if (tell_parent(broad_domain->dom_domain, addr)) 625 syslog(LOG_WARNING, "lost connection to parent"); 626 return (TRUE); 627 } 628 629 if (yp_restricted && verify(addr->sin_addr)) { 630 retries++; 631 syslog(LOG_NOTICE, "NIS server at %s not in restricted mode access list -- rejecting.\n",inet_ntoa(addr->sin_addr)); 632 return (FALSE); 633 } else { 634 if (tell_parent(broad_domain->dom_domain, addr)) 635 syslog(LOG_WARNING, "lost connection to parent"); 636 return (TRUE); 637 } 638 } 639 640 /* 641 * The right way to send RPC broadcasts. 642 * Use the clnt_broadcast() RPC service. Unfortunately, clnt_broadcast() 643 * blocks while waiting for replies, so we have to fork off separate 644 * broadcaster processes that do the waiting and then transmit their 645 * results back to the parent for processing. We also have to remember 646 * to save the name of the domain we're trying to bind in a global 647 * variable since clnt_broadcast() provides no way to pass things to 648 * the 'eachresult' callback function. 649 */ 650 void 651 broadcast(struct _dom_binding *ypdb) 652 { 653 bool_t out = FALSE; 654 enum clnt_stat stat; 655 656 if (children >= MAX_CHILDREN || ypdb->dom_broadcast_pid) 657 return; 658 659 if (pipe(ypdb->dom_pipe_fds) < 0) { 660 syslog(LOG_WARNING, "pipe: %m"); 661 return; 662 } 663 664 if (ypdb->dom_vers == -1 && (long)ypdb->dom_server_addr.sin_addr.s_addr) { 665 if (not_responding_count++ >= NOT_RESPONDING_HYSTERESIS) { 666 not_responding_count = NOT_RESPONDING_HYSTERESIS; 667 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding", 668 inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain); 669 } 670 } 671 672 broad_domain = ypdb; 673 flock(ypdb->dom_lockfd, LOCK_UN); 674 675 switch ((ypdb->dom_broadcast_pid = fork())) { 676 case 0: 677 close(READFD); 678 signal(SIGCHLD, SIG_DFL); 679 signal(SIGTERM, SIG_DFL); 680 break; 681 case -1: 682 syslog(LOG_WARNING, "fork: %m"); 683 close(READFD); 684 close(WRITEFD); 685 return; 686 default: 687 close(WRITEFD); 688 FD_SET(READFD, &svc_fdset); 689 children++; 690 return; 691 } 692 693 /* Release all locks before doing anything else. */ 694 while (ypbindlist) { 695 close(ypbindlist->dom_lockfd); 696 ypbindlist = ypbindlist->dom_pnext; 697 } 698 close(yplockfd); 699 700 /* 701 * Special 'many-cast' behavior. If we're in restricted mode, 702 * we have a list of possible server addresses to try. What 703 * we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK 704 * procedure and time the replies. Whoever replies fastest 705 * gets to be our server. Note that this is not a broadcast 706 * operation: we transmit uni-cast datagrams only. 707 */ 708 if (yp_restricted && yp_manycast) { 709 short port; 710 int i; 711 struct sockaddr_in sin; 712 713 i = __yp_ping(restricted_addrs, yp_restricted, 714 ypdb->dom_domain, &port); 715 if (i == -1) { 716 bzero(&ypdb->dom_server_addr, 717 sizeof(struct sockaddr_in)); 718 if (tell_parent(ypdb->dom_domain, 719 &ypdb->dom_server_addr)) 720 syslog(LOG_WARNING, "lost connection to parent"); 721 } else { 722 bzero(&sin, sizeof(struct sockaddr_in)); 723 bcopy(&restricted_addrs[i], 724 &sin.sin_addr, sizeof(struct in_addr)); 725 sin.sin_family = AF_INET; 726 sin.sin_port = port; 727 if (tell_parent(broad_domain->dom_domain, &sin)) 728 syslog(LOG_WARNING, 729 "lost connection to parent"); 730 } 731 _exit(0); 732 } 733 734 retries = 0; 735 736 { 737 char *ptr; 738 739 ptr = ypdb->dom_domain; 740 stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK, 741 (xdrproc_t)xdr_domainname, &ptr, 742 (xdrproc_t)xdr_bool, &out, 743 (resultproc_t)broadcast_result); 744 } 745 746 if (stat != RPC_SUCCESS) { 747 bzero(&ypdb->dom_server_addr, 748 sizeof(struct sockaddr_in)); 749 if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr)) 750 syslog(LOG_WARNING, "lost connection to parent"); 751 } 752 753 _exit(0); 754 } 755 756 /* 757 * The right way to check if a server is alive. 758 * Attempt to get a client handle pointing to the server and send a 759 * YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE, 760 * we invalidate this binding entry and send out a broadcast to try to 761 * establish a new binding. Note that we treat non-default domains 762 * specially: once bound, we keep tabs on our server, but if it 763 * goes away and fails to respond after one round of broadcasting, we 764 * abandon it until a client specifically references it again. We make 765 * every effort to keep our default domain bound, however, since we 766 * need it to keep the system on its feet. 767 */ 768 int 769 ping(struct _dom_binding *ypdb) 770 { 771 bool_t out; 772 struct timeval interval, timeout; 773 enum clnt_stat stat; 774 int rpcsock = RPC_ANYSOCK; 775 CLIENT *client_handle; 776 777 interval.tv_sec = FAIL_THRESHOLD; 778 interval.tv_usec = 0; 779 timeout.tv_sec = FAIL_THRESHOLD; 780 timeout.tv_usec = 0; 781 782 if (ypdb->dom_broadcast_pid) 783 return(1); 784 785 if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr, 786 YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE, 787 RPCSMALLMSGSIZE)) == (CLIENT *)NULL) { 788 /* Can't get a handle: we're dead. */ 789 ypdb->dom_alive = 0; 790 ypdb->dom_vers = -1; 791 broadcast(ypdb); 792 return(1); 793 } 794 795 { 796 char *ptr; 797 798 ptr = ypdb->dom_domain; 799 800 stat = clnt_call(client_handle, YPPROC_DOMAIN, 801 (xdrproc_t)xdr_domainname, &ptr, 802 (xdrproc_t)xdr_bool, &out, timeout); 803 if (stat != RPC_SUCCESS || out == FALSE) { 804 ypdb->dom_alive = 0; 805 ypdb->dom_vers = -1; 806 clnt_destroy(client_handle); 807 broadcast(ypdb); 808 return(1); 809 } 810 } 811 812 clnt_destroy(client_handle); 813 return(0); 814 } 815 816 void 817 rpc_received(char *dom, struct sockaddr_in *raddrp, int force) 818 { 819 struct _dom_binding *ypdb, *prev = NULL; 820 struct iovec iov[2]; 821 struct ypbind_resp ybr; 822 char path[MAXPATHLEN]; 823 int fd; 824 825 /*printf("returned from %s/%d about %s\n", inet_ntoa(raddrp->sin_addr), 826 ntohs(raddrp->sin_port), dom);*/ 827 828 if (dom == NULL) 829 return; 830 831 for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) { 832 if (strcmp(ypdb->dom_domain, dom) == 0) 833 break; 834 prev = ypdb; 835 } 836 837 if (ypdb && force) { 838 if (ypdb->dom_broadcast_pid) { 839 kill(ypdb->dom_broadcast_pid, SIGINT); 840 close(READFD); 841 FD_CLR(READFD, &fdsr); 842 FD_CLR(READFD, &svc_fdset); 843 READFD = WRITEFD = -1; 844 } 845 } 846 847 /* if in secure mode, check originating port number */ 848 if ((ypsecuremode && (ntohs(raddrp->sin_port) >= IPPORT_RESERVED))) { 849 syslog(LOG_WARNING, "Rejected NIS server on [%s/%d] for domain %s.", 850 inet_ntoa(raddrp->sin_addr), ntohs(raddrp->sin_port), 851 dom); 852 if (ypdb != NULL) { 853 ypdb->dom_broadcast_pid = 0; 854 ypdb->dom_alive = 0; 855 } 856 return; 857 } 858 859 if (raddrp->sin_addr.s_addr == (long)0) { 860 switch (ypdb->dom_default) { 861 case 0: 862 if (prev == NULL) 863 ypbindlist = ypdb->dom_pnext; 864 else 865 prev->dom_pnext = ypdb->dom_pnext; 866 sprintf(path, "%s/%s.%ld", BINDINGDIR, 867 ypdb->dom_domain, YPVERS); 868 close(ypdb->dom_lockfd); 869 unlink(path); 870 free(ypdb); 871 domains--; 872 return; 873 case 1: 874 ypdb->dom_broadcast_pid = 0; 875 ypdb->dom_alive = 0; 876 broadcast(ypdb); 877 return; 878 default: 879 break; 880 } 881 } 882 883 if (ypdb == NULL) { 884 if (force == 0) 885 return; 886 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb); 887 if (ypdb == NULL) { 888 syslog(LOG_WARNING, "malloc: %m"); 889 return; 890 } 891 bzero(ypdb, sizeof *ypdb); 892 strncpy(ypdb->dom_domain, dom, sizeof ypdb->dom_domain); 893 ypdb->dom_lockfd = -1; 894 ypdb->dom_default = 0; 895 ypdb->dom_pnext = ypbindlist; 896 ypbindlist = ypdb; 897 } 898 899 /* We've recovered from a crash: inform the world. */ 900 if (ypdb->dom_vers == -1 && ypdb->dom_server_addr.sin_addr.s_addr) { 901 if (not_responding_count >= NOT_RESPONDING_HYSTERESIS) { 902 not_responding_count = 0; 903 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" OK", 904 inet_ntoa(raddrp->sin_addr), ypdb->dom_domain); 905 } 906 } 907 908 bcopy(raddrp, &ypdb->dom_server_addr, 909 sizeof ypdb->dom_server_addr); 910 911 ypdb->dom_vers = YPVERS; 912 ypdb->dom_alive = 1; 913 ypdb->dom_broadcast_pid = 0; 914 915 if (ypdb->dom_lockfd != -1) 916 close(ypdb->dom_lockfd); 917 918 sprintf(path, "%s/%s.%ld", BINDINGDIR, 919 ypdb->dom_domain, ypdb->dom_vers); 920 #ifdef O_SHLOCK 921 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) { 922 (void)mkdir(BINDINGDIR, 0755); 923 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) 924 return; 925 } 926 #else 927 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) { 928 (void)mkdir(BINDINGDIR, 0755); 929 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) 930 return; 931 } 932 flock(fd, LOCK_SH); 933 #endif 934 935 /* 936 * ok, if BINDINGDIR exists, and we can create the binding file, 937 * then write to it.. 938 */ 939 ypdb->dom_lockfd = fd; 940 941 iov[0].iov_base = (char *)&(udptransp->xp_port); 942 iov[0].iov_len = sizeof udptransp->xp_port; 943 iov[1].iov_base = (char *)&ybr; 944 iov[1].iov_len = sizeof ybr; 945 946 bzero(&ybr, sizeof ybr); 947 ybr.ypbind_status = YPBIND_SUCC_VAL; 948 *(u_int32_t *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = raddrp->sin_addr.s_addr; 949 *(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = raddrp->sin_port; 950 951 if (writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) { 952 syslog(LOG_WARNING, "write: %m"); 953 close(ypdb->dom_lockfd); 954 ypdb->dom_lockfd = -1; 955 return; 956 } 957 } 958 959 /* 960 * Check address against list of allowed servers. Return 0 if okay, 961 * 1 if not matched. 962 */ 963 int 964 verify(struct in_addr addr) 965 { 966 int i; 967 968 for (i = 0; i < RESTRICTED_SERVERS; i++) 969 if (!bcmp(&addr, &restricted_addrs[i], sizeof(struct in_addr))) 970 return(0); 971 972 return(1); 973 } 974 975 /* 976 * Try to set restricted mode. We default to normal mode if we can't 977 * resolve the specified hostnames. 978 */ 979 void 980 yp_restricted_mode(char *args) 981 { 982 struct hostent *h; 983 int i = 0; 984 char *s; 985 986 /* Find the restricted domain. */ 987 if ((s = strsep(&args, ",")) == NULL) 988 return; 989 domain_name = s; 990 991 /* Get the addresses of the servers. */ 992 while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) { 993 if ((h = gethostbyname(s)) == NULL) 994 return; 995 bcopy (h->h_addr_list[0], &restricted_addrs[i], 996 sizeof(struct in_addr)); 997 i++; 998 } 999 1000 /* ypset and ypsetme not allowed with restricted mode */ 1001 ypsetmode = YPSET_NO; 1002 1003 yp_restricted = i; 1004 return; 1005 } 1006