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 static char *domain_name; 110 static 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 static int ypsetmode = YPSET_NO; 117 static int ypsecuremode = 0; 118 static 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 static int yp_restricted = 0; 130 static int yp_manycast = 0; 131 static 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 static int retries = 0; 152 static int children = 0; 153 static int domains = 0; 154 static int yplockfd; 155 static fd_set fdsr; 156 157 static 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 static 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 if (strlen(*argp) > YPMAXDOMAIN) { 203 syslog(LOG_WARNING, "domain %s too long", *argp); 204 res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC; 205 return (&res); 206 } 207 ypdb = malloc(sizeof *ypdb); 208 if (ypdb == NULL) { 209 syslog(LOG_WARNING, "malloc: %m"); 210 res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC; 211 return (&res); 212 } 213 bzero(ypdb, sizeof *ypdb); 214 strlcpy(ypdb->dom_domain, *argp, sizeof ypdb->dom_domain); 215 ypdb->dom_vers = YPVERS; 216 ypdb->dom_alive = 0; 217 ypdb->dom_default = 0; 218 ypdb->dom_lockfd = -1; 219 sprintf(path, "%s/%s.%ld", BINDINGDIR, 220 ypdb->dom_domain, ypdb->dom_vers); 221 unlink(path); 222 ypdb->dom_pnext = ypbindlist; 223 ypbindlist = ypdb; 224 domains++; 225 } 226 227 if (ping(ypdb)) { 228 return (&res); 229 } 230 231 res.ypbind_status = YPBIND_SUCC_VAL; 232 res.ypbind_resp_u.ypbind_error = 0; /* Success */ 233 memcpy(&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr, 234 &ypdb->dom_server_addr.sin_addr.s_addr, sizeof(u_int32_t)); 235 memcpy(&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port, 236 &ypdb->dom_server_addr.sin_port, sizeof(u_short)); 237 /*printf("domain %s at %s/%d\n", ypdb->dom_domain, 238 inet_ntoa(ypdb->dom_server_addr.sin_addr), 239 ntohs(ypdb->dom_server_addr.sin_port));*/ 240 return (&res); 241 } 242 243 void * 244 ypbindproc_setdom_2_yp(SVCXPRT *transp, ypbind_setdom *argp, CLIENT *clnt) 245 { 246 struct sockaddr_in *fromsin, bindsin; 247 static char *result = NULL; 248 249 if (strchr(argp->ypsetdom_domain, '/')) { 250 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \ 251 rejecting.", argp->ypsetdom_domain); 252 return(NULL); 253 } 254 fromsin = svc_getcaller(transp); 255 256 switch (ypsetmode) { 257 case YPSET_LOCAL: 258 if (fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) { 259 svcerr_noprog(transp); 260 return(NULL); 261 } 262 break; 263 case YPSET_ALL: 264 break; 265 case YPSET_NO: 266 default: 267 svcerr_noprog(transp); 268 return(NULL); 269 } 270 271 if (ntohs(fromsin->sin_port) >= IPPORT_RESERVED) { 272 svcerr_noprog(transp); 273 return(NULL); 274 } 275 276 if (argp->ypsetdom_vers != YPVERS) { 277 svcerr_noprog(transp); 278 return(NULL); 279 } 280 281 bzero(&bindsin, sizeof bindsin); 282 bindsin.sin_family = AF_INET; 283 memcpy(&bindsin.sin_addr.s_addr, 284 &argp->ypsetdom_binding.ypbind_binding_addr, 285 sizeof(u_int32_t)); 286 memcpy(&bindsin.sin_port, 287 &argp->ypsetdom_binding.ypbind_binding_port, 288 sizeof(u_short)); 289 rpc_received(argp->ypsetdom_domain, &bindsin, 1); 290 291 return((void *) &result); 292 } 293 294 void 295 ypbindprog_2(struct svc_req *rqstp, register SVCXPRT *transp) 296 { 297 union { 298 domainname ypbindproc_domain_2_arg; 299 struct ypbind_setdom ypbindproc_setdom_2_arg; 300 } argument; 301 struct authunix_parms *creds; 302 char *result; 303 bool_t (*xdr_argument)(), (*xdr_result)(); 304 char *(*local)(); 305 306 switch (rqstp->rq_proc) { 307 case YPBINDPROC_NULL: 308 xdr_argument = xdr_void; 309 xdr_result = xdr_void; 310 local = (char *(*)()) ypbindproc_null_2_yp; 311 break; 312 313 case YPBINDPROC_DOMAIN: 314 xdr_argument = xdr_domainname; 315 xdr_result = xdr_ypbind_resp; 316 local = (char *(*)()) ypbindproc_domain_2_yp; 317 break; 318 319 case YPBINDPROC_SETDOM: 320 switch (rqstp->rq_cred.oa_flavor) { 321 case AUTH_UNIX: 322 creds = (struct authunix_parms *)rqstp->rq_clntcred; 323 if (creds->aup_uid != 0) { 324 svcerr_auth(transp, AUTH_BADCRED); 325 return; 326 } 327 break; 328 default: 329 svcerr_auth(transp, AUTH_TOOWEAK); 330 return; 331 } 332 333 xdr_argument = xdr_ypbind_setdom; 334 xdr_result = xdr_void; 335 local = (char *(*)()) ypbindproc_setdom_2_yp; 336 break; 337 338 default: 339 svcerr_noproc(transp); 340 return; 341 } 342 bzero(&argument, sizeof(argument)); 343 if (!svc_getargs(transp, (xdrproc_t)xdr_argument, &argument)) { 344 svcerr_decode(transp); 345 return; 346 } 347 result = (*local)(transp, &argument, rqstp); 348 if (result != NULL && 349 !svc_sendreply(transp, (xdrproc_t)xdr_result, result)) { 350 svcerr_systemerr(transp); 351 } 352 return; 353 } 354 355 /* Jack the reaper */ 356 void 357 reaper(int sig) 358 { 359 int st; 360 361 while (wait3(&st, WNOHANG, NULL) > 0) 362 children--; 363 } 364 365 void 366 terminate(int sig) 367 { 368 struct _dom_binding *ypdb; 369 char path[MAXPATHLEN]; 370 371 if (ppid != getpid()) 372 exit(0); 373 374 for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) { 375 close(ypdb->dom_lockfd); 376 if (ypdb->dom_broadcast_pid) 377 kill(ypdb->dom_broadcast_pid, SIGINT); 378 sprintf(path, "%s/%s.%ld", BINDINGDIR, 379 ypdb->dom_domain, ypdb->dom_vers); 380 unlink(path); 381 } 382 close(yplockfd); 383 unlink(YPBINDLOCK); 384 pmap_unset(YPBINDPROG, YPBINDVERS); 385 exit(0); 386 } 387 388 int 389 main(int argc, char *argv[]) 390 { 391 struct timeval tv; 392 int i; 393 DIR *dird; 394 struct dirent *dirp; 395 struct _dom_binding *ypdb, *next; 396 397 /* Check that another ypbind isn't already running. */ 398 if ((yplockfd = (open(YPBINDLOCK, O_RDONLY|O_CREAT, 0444))) == -1) 399 err(1, "%s", YPBINDLOCK); 400 401 if (flock(yplockfd, LOCK_EX|LOCK_NB) == -1 && errno == EWOULDBLOCK) 402 errx(1, "another ypbind is already running. Aborting"); 403 404 /* XXX domainname will be overridden if we use restricted mode */ 405 yp_get_default_domain(&domain_name); 406 if (domain_name[0] == '\0') 407 errx(1, "domainname not set. Aborting"); 408 409 for (i = 1; i<argc; i++) { 410 if (strcmp("-ypset", argv[i]) == 0) 411 ypsetmode = YPSET_ALL; 412 else if (strcmp("-ypsetme", argv[i]) == 0) 413 ypsetmode = YPSET_LOCAL; 414 else if (strcmp("-s", argv[i]) == 0) 415 ypsecuremode++; 416 else if (strcmp("-S", argv[i]) == 0 && argc > i) 417 yp_restricted_mode(argv[++i]); 418 else if (strcmp("-m", argv[i]) == 0) 419 yp_manycast++; 420 else 421 errx(1, "unknown option: %s", argv[i]); 422 } 423 424 if (strlen(domain_name) > YPMAXDOMAIN) 425 warnx("truncating domain name %s", domain_name); 426 427 /* blow away everything in BINDINGDIR (if it exists) */ 428 429 if ((dird = opendir(BINDINGDIR)) != NULL) { 430 char path[MAXPATHLEN]; 431 while ((dirp = readdir(dird)) != NULL) 432 if (strcmp(dirp->d_name, ".") && 433 strcmp(dirp->d_name, "..")) { 434 sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name); 435 unlink(path); 436 } 437 closedir(dird); 438 } 439 440 #ifdef DAEMON 441 if (daemon(0,0)) 442 err(1, "fork"); 443 #endif 444 445 pmap_unset(YPBINDPROG, YPBINDVERS); 446 447 udptransp = svcudp_create(RPC_ANYSOCK); 448 if (udptransp == NULL) 449 errx(1, "cannot create udp service"); 450 if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2, 451 IPPROTO_UDP)) 452 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)"); 453 454 tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0); 455 if (tcptransp == NULL) 456 errx(1, "cannot create tcp service"); 457 458 if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2, 459 IPPROTO_TCP)) 460 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)"); 461 462 /* build initial domain binding, make it "unsuccessful" */ 463 ypbindlist = malloc(sizeof *ypbindlist); 464 if (ypbindlist == NULL) 465 errx(1, "malloc"); 466 bzero(ypbindlist, sizeof *ypbindlist); 467 strlcpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain); 468 ypbindlist->dom_vers = YPVERS; 469 ypbindlist->dom_alive = 0; 470 ypbindlist->dom_lockfd = -1; 471 ypbindlist->dom_default = 1; 472 domains++; 473 474 signal(SIGCHLD, reaper); 475 signal(SIGTERM, terminate); 476 477 ppid = getpid(); /* Remember who we are. */ 478 479 openlog(argv[0], LOG_PID, LOG_DAEMON); 480 481 if (madvise(NULL, 0, MADV_PROTECT) != 0) 482 syslog(LOG_WARNING, "madvise(): %m"); 483 484 /* Kick off the default domain */ 485 broadcast(ypbindlist); 486 487 while (1) { 488 fdsr = svc_fdset; 489 490 tv.tv_sec = 60; 491 tv.tv_usec = 0; 492 493 switch (select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) { 494 case 0: 495 checkwork(); 496 break; 497 case -1: 498 if (errno != EINTR) 499 syslog(LOG_WARNING, "select: %m"); 500 break; 501 default: 502 for (ypdb = ypbindlist; ypdb; ypdb = next) { 503 next = ypdb->dom_pnext; 504 if (READFD > 0 && FD_ISSET(READFD, &fdsr)) { 505 handle_children(ypdb); 506 if (children == (MAX_CHILDREN - 1)) 507 checkwork(); 508 } 509 } 510 svc_getreqset(&fdsr); 511 break; 512 } 513 } 514 515 /* NOTREACHED */ 516 exit(1); 517 } 518 519 void 520 checkwork(void) 521 { 522 struct _dom_binding *ypdb; 523 524 for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) 525 ping(ypdb); 526 } 527 528 /* The clnt_broadcast() callback mechanism sucks. */ 529 530 /* 531 * Receive results from broadcaster. Don't worry about passing 532 * bogus info to rpc_received() -- it can handle it. Note that we 533 * must be sure to invalidate the dom_pipe_fds descriptors here: 534 * since descriptors can be re-used, we have to make sure we 535 * don't mistake one of the RPC descriptors for one of the pipes. 536 * What's weird is that forgetting to invalidate the pipe descriptors 537 * doesn't always result in an error (otherwise I would have caught 538 * the mistake much sooner), even though logically it should. 539 */ 540 void 541 handle_children(struct _dom_binding *ypdb) 542 { 543 char buf[YPMAXDOMAIN + 1]; 544 struct sockaddr_in addr; 545 int d = 0, a = 0; 546 struct _dom_binding *y, *prev = NULL; 547 char path[MAXPATHLEN]; 548 549 if ((d = read(READFD, &buf, sizeof(buf))) <= 0) 550 syslog(LOG_WARNING, "could not read from child: %m"); 551 552 if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0) 553 syslog(LOG_WARNING, "could not read from child: %m"); 554 555 close(READFD); 556 FD_CLR(READFD, &fdsr); 557 FD_CLR(READFD, &svc_fdset); 558 READFD = WRITEFD = -1; 559 if (d > 0 && a > 0) 560 rpc_received(buf, &addr, 0); 561 else { 562 for (y = ypbindlist; y; y = y->dom_pnext) { 563 if (y == ypdb) 564 break; 565 prev = y; 566 } 567 switch (ypdb->dom_default) { 568 case 0: 569 if (prev == NULL) 570 ypbindlist = y->dom_pnext; 571 else 572 prev->dom_pnext = y->dom_pnext; 573 sprintf(path, "%s/%s.%ld", BINDINGDIR, 574 ypdb->dom_domain, YPVERS); 575 close(ypdb->dom_lockfd); 576 unlink(path); 577 free(ypdb); 578 domains--; 579 return; 580 case 1: 581 ypdb->dom_broadcast_pid = 0; 582 ypdb->dom_alive = 0; 583 broadcast(ypdb); 584 return; 585 default: 586 break; 587 } 588 } 589 590 return; 591 } 592 593 /* 594 * Send our dying words back to our parent before we perish. 595 */ 596 int 597 tell_parent(char *dom, struct sockaddr_in *addr) 598 { 599 char buf[YPMAXDOMAIN + 1]; 600 struct timeval timeout; 601 fd_set fds; 602 603 timeout.tv_sec = 5; 604 timeout.tv_usec = 0; 605 606 sprintf(buf, "%s", broad_domain->dom_domain); 607 if (write(BROADFD, &buf, sizeof(buf)) < 0) 608 return(1); 609 610 /* 611 * Stay in sync with parent: wait for it to read our first 612 * message before sending the second. 613 */ 614 615 FD_ZERO(&fds); 616 FD_SET(BROADFD, &fds); 617 if (select(FD_SETSIZE, NULL, &fds, NULL, &timeout) == -1) 618 return(1); 619 if (FD_ISSET(BROADFD, &fds)) { 620 if (write(BROADFD, addr, sizeof(struct sockaddr_in)) < 0) 621 return(1); 622 } else { 623 return(1); 624 } 625 626 close(BROADFD); 627 return (0); 628 } 629 630 static bool_t 631 broadcast_result(bool_t *out, struct sockaddr_in *addr) 632 { 633 if (retries >= MAX_RETRIES) { 634 bzero(addr, sizeof(struct sockaddr_in)); 635 if (tell_parent(broad_domain->dom_domain, addr)) 636 syslog(LOG_WARNING, "lost connection to parent"); 637 return (TRUE); 638 } 639 640 if (yp_restricted && verify(addr->sin_addr)) { 641 retries++; 642 syslog(LOG_NOTICE, "NIS server at %s not in restricted mode access list -- rejecting.\n",inet_ntoa(addr->sin_addr)); 643 return (FALSE); 644 } else { 645 if (tell_parent(broad_domain->dom_domain, addr)) 646 syslog(LOG_WARNING, "lost connection to parent"); 647 return (TRUE); 648 } 649 } 650 651 /* 652 * The right way to send RPC broadcasts. 653 * Use the clnt_broadcast() RPC service. Unfortunately, clnt_broadcast() 654 * blocks while waiting for replies, so we have to fork off separate 655 * broadcaster processes that do the waiting and then transmit their 656 * results back to the parent for processing. We also have to remember 657 * to save the name of the domain we're trying to bind in a global 658 * variable since clnt_broadcast() provides no way to pass things to 659 * the 'eachresult' callback function. 660 */ 661 void 662 broadcast(struct _dom_binding *ypdb) 663 { 664 bool_t out = FALSE; 665 enum clnt_stat stat; 666 667 if (children >= MAX_CHILDREN || ypdb->dom_broadcast_pid) 668 return; 669 670 if (pipe(ypdb->dom_pipe_fds) < 0) { 671 syslog(LOG_WARNING, "pipe: %m"); 672 return; 673 } 674 675 if (ypdb->dom_vers == -1 && (long)ypdb->dom_server_addr.sin_addr.s_addr) { 676 if (not_responding_count++ >= NOT_RESPONDING_HYSTERESIS) { 677 not_responding_count = NOT_RESPONDING_HYSTERESIS; 678 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding", 679 inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain); 680 } 681 } 682 683 broad_domain = ypdb; 684 flock(ypdb->dom_lockfd, LOCK_UN); 685 686 switch ((ypdb->dom_broadcast_pid = fork())) { 687 case 0: 688 close(READFD); 689 signal(SIGCHLD, SIG_DFL); 690 signal(SIGTERM, SIG_DFL); 691 break; 692 case -1: 693 syslog(LOG_WARNING, "fork: %m"); 694 close(READFD); 695 close(WRITEFD); 696 return; 697 default: 698 close(WRITEFD); 699 FD_SET(READFD, &svc_fdset); 700 children++; 701 return; 702 } 703 704 /* Release all locks before doing anything else. */ 705 while (ypbindlist) { 706 close(ypbindlist->dom_lockfd); 707 ypbindlist = ypbindlist->dom_pnext; 708 } 709 close(yplockfd); 710 711 /* 712 * Special 'many-cast' behavior. If we're in restricted mode, 713 * we have a list of possible server addresses to try. What 714 * we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK 715 * procedure and time the replies. Whoever replies fastest 716 * gets to be our server. Note that this is not a broadcast 717 * operation: we transmit uni-cast datagrams only. 718 */ 719 if (yp_restricted && yp_manycast) { 720 short port; 721 int i; 722 struct sockaddr_in sin; 723 724 i = __yp_ping(restricted_addrs, yp_restricted, 725 ypdb->dom_domain, &port); 726 if (i == -1) { 727 bzero(&ypdb->dom_server_addr, 728 sizeof(struct sockaddr_in)); 729 if (tell_parent(ypdb->dom_domain, 730 &ypdb->dom_server_addr)) 731 syslog(LOG_WARNING, "lost connection to parent"); 732 } else { 733 bzero(&sin, sizeof(struct sockaddr_in)); 734 bcopy(&restricted_addrs[i], 735 &sin.sin_addr, sizeof(struct in_addr)); 736 sin.sin_family = AF_INET; 737 sin.sin_port = port; 738 if (tell_parent(broad_domain->dom_domain, &sin)) 739 syslog(LOG_WARNING, 740 "lost connection to parent"); 741 } 742 _exit(0); 743 } 744 745 retries = 0; 746 747 { 748 char *ptr; 749 750 ptr = ypdb->dom_domain; 751 stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK, 752 (xdrproc_t)xdr_domainname, &ptr, 753 (xdrproc_t)xdr_bool, &out, 754 (resultproc_t)broadcast_result); 755 } 756 757 if (stat != RPC_SUCCESS) { 758 bzero(&ypdb->dom_server_addr, 759 sizeof(struct sockaddr_in)); 760 if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr)) 761 syslog(LOG_WARNING, "lost connection to parent"); 762 } 763 764 _exit(0); 765 } 766 767 /* 768 * The right way to check if a server is alive. 769 * Attempt to get a client handle pointing to the server and send a 770 * YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE, 771 * we invalidate this binding entry and send out a broadcast to try to 772 * establish a new binding. Note that we treat non-default domains 773 * specially: once bound, we keep tabs on our server, but if it 774 * goes away and fails to respond after one round of broadcasting, we 775 * abandon it until a client specifically references it again. We make 776 * every effort to keep our default domain bound, however, since we 777 * need it to keep the system on its feet. 778 */ 779 int 780 ping(struct _dom_binding *ypdb) 781 { 782 bool_t out; 783 struct timeval interval, timeout; 784 enum clnt_stat stat; 785 int rpcsock = RPC_ANYSOCK; 786 CLIENT *client_handle; 787 788 interval.tv_sec = FAIL_THRESHOLD; 789 interval.tv_usec = 0; 790 timeout.tv_sec = FAIL_THRESHOLD; 791 timeout.tv_usec = 0; 792 793 if (ypdb->dom_broadcast_pid) 794 return(1); 795 796 if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr, 797 YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE, 798 RPCSMALLMSGSIZE)) == (CLIENT *)NULL) { 799 /* Can't get a handle: we're dead. */ 800 ypdb->dom_alive = 0; 801 ypdb->dom_vers = -1; 802 broadcast(ypdb); 803 return(1); 804 } 805 806 { 807 char *ptr; 808 809 ptr = ypdb->dom_domain; 810 811 stat = clnt_call(client_handle, YPPROC_DOMAIN, 812 (xdrproc_t)xdr_domainname, &ptr, 813 (xdrproc_t)xdr_bool, &out, timeout); 814 if (stat != RPC_SUCCESS || out == FALSE) { 815 ypdb->dom_alive = 0; 816 ypdb->dom_vers = -1; 817 clnt_destroy(client_handle); 818 broadcast(ypdb); 819 return(1); 820 } 821 } 822 823 clnt_destroy(client_handle); 824 return(0); 825 } 826 827 void 828 rpc_received(char *dom, struct sockaddr_in *raddrp, int force) 829 { 830 struct _dom_binding *ypdb, *prev = NULL; 831 struct iovec iov[2]; 832 struct ypbind_resp ybr; 833 char path[MAXPATHLEN]; 834 int fd; 835 836 /*printf("returned from %s/%d about %s\n", inet_ntoa(raddrp->sin_addr), 837 ntohs(raddrp->sin_port), dom);*/ 838 839 if (dom == NULL) 840 return; 841 842 for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) { 843 if (strcmp(ypdb->dom_domain, dom) == 0) 844 break; 845 prev = ypdb; 846 } 847 848 if (ypdb && force) { 849 if (ypdb->dom_broadcast_pid) { 850 kill(ypdb->dom_broadcast_pid, SIGINT); 851 close(READFD); 852 FD_CLR(READFD, &fdsr); 853 FD_CLR(READFD, &svc_fdset); 854 READFD = WRITEFD = -1; 855 } 856 } 857 858 /* if in secure mode, check originating port number */ 859 if ((ypsecuremode && (ntohs(raddrp->sin_port) >= IPPORT_RESERVED))) { 860 syslog(LOG_WARNING, "Rejected NIS server on [%s/%d] for domain %s.", 861 inet_ntoa(raddrp->sin_addr), ntohs(raddrp->sin_port), 862 dom); 863 if (ypdb != NULL) { 864 ypdb->dom_broadcast_pid = 0; 865 ypdb->dom_alive = 0; 866 } 867 return; 868 } 869 870 if (raddrp->sin_addr.s_addr == (long)0) { 871 switch (ypdb->dom_default) { 872 case 0: 873 if (prev == NULL) 874 ypbindlist = ypdb->dom_pnext; 875 else 876 prev->dom_pnext = ypdb->dom_pnext; 877 sprintf(path, "%s/%s.%ld", BINDINGDIR, 878 ypdb->dom_domain, YPVERS); 879 close(ypdb->dom_lockfd); 880 unlink(path); 881 free(ypdb); 882 domains--; 883 return; 884 case 1: 885 ypdb->dom_broadcast_pid = 0; 886 ypdb->dom_alive = 0; 887 broadcast(ypdb); 888 return; 889 default: 890 break; 891 } 892 } 893 894 if (ypdb == NULL) { 895 if (force == 0) 896 return; 897 if (strlen(dom) > YPMAXDOMAIN) { 898 syslog(LOG_WARNING, "domain %s too long", dom); 899 return; 900 } 901 ypdb = malloc(sizeof *ypdb); 902 if (ypdb == NULL) { 903 syslog(LOG_WARNING, "malloc: %m"); 904 return; 905 } 906 bzero(ypdb, sizeof *ypdb); 907 strlcpy(ypdb->dom_domain, dom, sizeof ypdb->dom_domain); 908 ypdb->dom_lockfd = -1; 909 ypdb->dom_default = 0; 910 ypdb->dom_pnext = ypbindlist; 911 ypbindlist = ypdb; 912 } 913 914 /* We've recovered from a crash: inform the world. */ 915 if (ypdb->dom_vers == -1 && ypdb->dom_server_addr.sin_addr.s_addr) { 916 if (not_responding_count >= NOT_RESPONDING_HYSTERESIS) { 917 not_responding_count = 0; 918 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" OK", 919 inet_ntoa(raddrp->sin_addr), ypdb->dom_domain); 920 } 921 } 922 923 bcopy(raddrp, &ypdb->dom_server_addr, 924 sizeof ypdb->dom_server_addr); 925 926 ypdb->dom_vers = YPVERS; 927 ypdb->dom_alive = 1; 928 ypdb->dom_broadcast_pid = 0; 929 930 if (ypdb->dom_lockfd != -1) 931 close(ypdb->dom_lockfd); 932 933 sprintf(path, "%s/%s.%ld", BINDINGDIR, 934 ypdb->dom_domain, ypdb->dom_vers); 935 #ifdef O_SHLOCK 936 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) { 937 (void)mkdir(BINDINGDIR, 0755); 938 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) 939 return; 940 } 941 #else 942 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) { 943 (void)mkdir(BINDINGDIR, 0755); 944 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) 945 return; 946 } 947 flock(fd, LOCK_SH); 948 #endif 949 950 /* 951 * ok, if BINDINGDIR exists, and we can create the binding file, 952 * then write to it.. 953 */ 954 ypdb->dom_lockfd = fd; 955 956 iov[0].iov_base = (char *)&(udptransp->xp_port); 957 iov[0].iov_len = sizeof udptransp->xp_port; 958 iov[1].iov_base = (char *)&ybr; 959 iov[1].iov_len = sizeof ybr; 960 961 bzero(&ybr, sizeof ybr); 962 ybr.ypbind_status = YPBIND_SUCC_VAL; 963 memcpy(&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr, 964 &raddrp->sin_addr.s_addr, sizeof(u_int32_t)); 965 memcpy(&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port, 966 &raddrp->sin_port, sizeof(u_short)); 967 968 if (writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) { 969 syslog(LOG_WARNING, "write: %m"); 970 close(ypdb->dom_lockfd); 971 ypdb->dom_lockfd = -1; 972 return; 973 } 974 } 975 976 /* 977 * Check address against list of allowed servers. Return 0 if okay, 978 * 1 if not matched. 979 */ 980 int 981 verify(struct in_addr addr) 982 { 983 int i; 984 985 for (i = 0; i < RESTRICTED_SERVERS; i++) 986 if (!bcmp(&addr, &restricted_addrs[i], sizeof(struct in_addr))) 987 return(0); 988 989 return(1); 990 } 991 992 /* 993 * Try to set restricted mode. We default to normal mode if we can't 994 * resolve the specified hostnames. 995 */ 996 void 997 yp_restricted_mode(char *args) 998 { 999 struct hostent *h; 1000 int i = 0; 1001 char *s; 1002 1003 /* Find the restricted domain. */ 1004 if ((s = strsep(&args, ",")) == NULL) 1005 return; 1006 domain_name = s; 1007 1008 /* Get the addresses of the servers. */ 1009 while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) { 1010 if ((h = gethostbyname(s)) == NULL) 1011 return; 1012 bcopy (h->h_addr_list[0], &restricted_addrs[i], 1013 sizeof(struct in_addr)); 1014 i++; 1015 } 1016 1017 /* ypset and ypsetme not allowed with restricted mode */ 1018 ypsetmode = YPSET_NO; 1019 1020 yp_restricted = i; 1021 return; 1022 } 1023