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 #ifndef lint 31 static const char rcsid[] = 32 "$FreeBSD$"; 33 #endif /* not lint */ 34 35 #include <sys/param.h> 36 #include <sys/types.h> 37 #include <sys/wait.h> 38 #include <sys/ioctl.h> 39 #include <sys/signal.h> 40 #include <sys/socket.h> 41 #include <sys/file.h> 42 #include <sys/fcntl.h> 43 #include <sys/stat.h> 44 #include <sys/uio.h> 45 #include <ctype.h> 46 #include <dirent.h> 47 #include <err.h> 48 #include <errno.h> 49 #include <netdb.h> 50 #include <signal.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <syslog.h> 55 #include <unistd.h> 56 #include <rpc/rpc.h> 57 #include <rpc/xdr.h> 58 #include <net/if.h> 59 #include <netinet/in.h> 60 #include <arpa/inet.h> 61 #include <rpc/pmap_clnt.h> 62 #include <rpc/pmap_prot.h> 63 #include <rpc/pmap_rmt.h> 64 #include <rpc/rpc_com.h> 65 #include <rpcsvc/yp.h> 66 struct dom_binding{}; 67 #include <rpcsvc/ypclnt.h> 68 #include "yp_ping.h" 69 70 #ifndef BINDINGDIR 71 #define BINDINGDIR "/var/yp/binding" 72 #endif 73 74 #ifndef YPBINDLOCK 75 #define YPBINDLOCK "/var/run/ypbind.lock" 76 #endif 77 78 struct _dom_binding { 79 struct _dom_binding *dom_pnext; 80 char dom_domain[YPMAXDOMAIN + 1]; 81 struct sockaddr_in dom_server_addr; 82 long int dom_vers; 83 int dom_lockfd; 84 int dom_alive; 85 int dom_broadcast_pid; 86 int dom_pipe_fds[2]; 87 int dom_default; 88 }; 89 90 #define READFD ypdb->dom_pipe_fds[0] 91 #define WRITEFD ypdb->dom_pipe_fds[1] 92 #define BROADFD broad_domain->dom_pipe_fds[1] 93 94 extern bool_t xdr_domainname(), xdr_ypbind_resp(); 95 extern bool_t xdr_ypreq_key(), xdr_ypresp_val(); 96 extern bool_t xdr_ypbind_setdom(); 97 98 void checkwork(void); 99 void *ypbindproc_null_2_yp(SVCXPRT *, void *, CLIENT *); 100 void *ypbindproc_setdom_2_yp(SVCXPRT *, struct ypbind_setdom *, CLIENT *); 101 void rpc_received(char *, struct sockaddr_in *, int); 102 void broadcast(struct _dom_binding *); 103 int ping(struct _dom_binding *); 104 int tell_parent(char *, struct sockaddr_in *); 105 void handle_children(struct _dom_binding *); 106 void reaper(int); 107 void terminate(int); 108 void yp_restricted_mode(char *); 109 int verify(struct in_addr); 110 111 char *domain_name; 112 struct _dom_binding *ypbindlist; 113 static struct _dom_binding *broad_domain; 114 115 #define YPSET_NO 0 116 #define YPSET_LOCAL 1 117 #define YPSET_ALL 2 118 int ypsetmode = YPSET_NO; 119 int ypsecuremode = 0; 120 int ppid; 121 122 /* 123 * Special restricted mode variables: when in restricted mode, only the 124 * specified restricted_domain will be bound, and only the servers listed 125 * in restricted_addrs will be used for binding. 126 */ 127 #define RESTRICTED_SERVERS 10 128 int yp_restricted = 0; 129 int yp_manycast = 0; 130 struct in_addr restricted_addrs[RESTRICTED_SERVERS]; 131 132 /* No more than MAX_CHILDREN child broadcasters at a time. */ 133 #ifndef MAX_CHILDREN 134 #define MAX_CHILDREN 5 135 #endif 136 /* No more than MAX_DOMAINS simultaneous domains */ 137 #ifndef MAX_DOMAINS 138 #define MAX_DOMAINS 200 139 #endif 140 /* RPC timeout value */ 141 #ifndef FAIL_THRESHOLD 142 #define FAIL_THRESHOLD 20 143 #endif 144 145 /* Number of times to fish for a response froma particular set of hosts */ 146 #ifndef MAX_RETRIES 147 #define MAX_RETRIES 30 148 #endif 149 150 int retries = 0; 151 int children = 0; 152 int domains = 0; 153 int yplockfd; 154 fd_set fdsr; 155 156 SVCXPRT *udptransp, *tcptransp; 157 158 void * 159 ypbindproc_null_2_yp(SVCXPRT *transp, void *argp, CLIENT *clnt) 160 { 161 static char res; 162 163 bzero((char *)&res, sizeof(res)); 164 return (void *)&res; 165 } 166 167 struct ypbind_resp * 168 ypbindproc_domain_2_yp(SVCXPRT *transp, domainname *argp, CLIENT *clnt) 169 { 170 static struct ypbind_resp res; 171 struct _dom_binding *ypdb; 172 char path[MAXPATHLEN]; 173 174 bzero((char *)&res, sizeof res); 175 res.ypbind_status = YPBIND_FAIL_VAL; 176 res.ypbind_resp_u.ypbind_error = YPBIND_ERR_NOSERV; 177 178 if (strchr(*argp, '/')) { 179 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \ 180 rejecting.", *argp); 181 return(&res); 182 } 183 184 for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) { 185 if (strcmp(ypdb->dom_domain, *argp) == 0) 186 break; 187 } 188 189 if (ypdb == NULL) { 190 if (yp_restricted) { 191 syslog(LOG_NOTICE, "Running in restricted mode -- request to bind domain \"%s\" rejected.\n", *argp); 192 return (&res); 193 } 194 195 if (domains >= MAX_DOMAINS) { 196 syslog(LOG_WARNING, "domain limit (%d) exceeded", 197 MAX_DOMAINS); 198 res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC; 199 return (&res); 200 } 201 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb); 202 if (ypdb == NULL) { 203 syslog(LOG_WARNING, "malloc: %m"); 204 res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC; 205 return (&res); 206 } 207 bzero((char *)ypdb, sizeof *ypdb); 208 strncpy(ypdb->dom_domain, *argp, sizeof ypdb->dom_domain); 209 ypdb->dom_vers = YPVERS; 210 ypdb->dom_alive = 0; 211 ypdb->dom_default = 0; 212 ypdb->dom_lockfd = -1; 213 sprintf(path, "%s/%s.%ld", BINDINGDIR, 214 ypdb->dom_domain, ypdb->dom_vers); 215 unlink(path); 216 ypdb->dom_pnext = ypbindlist; 217 ypbindlist = ypdb; 218 domains++; 219 } 220 221 if (ping(ypdb)) { 222 return (&res); 223 } 224 225 res.ypbind_status = YPBIND_SUCC_VAL; 226 res.ypbind_resp_u.ypbind_error = 0; /* Success */ 227 *(u_int32_t *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = 228 ypdb->dom_server_addr.sin_addr.s_addr; 229 *(u_short *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = 230 ypdb->dom_server_addr.sin_port; 231 /*printf("domain %s at %s/%d\n", ypdb->dom_domain, 232 inet_ntoa(ypdb->dom_server_addr.sin_addr), 233 ntohs(ypdb->dom_server_addr.sin_port));*/ 234 return (&res); 235 } 236 237 void * 238 ypbindproc_setdom_2_yp(SVCXPRT *transp, ypbind_setdom *argp, CLIENT *clnt) 239 { 240 struct sockaddr_in *fromsin, bindsin; 241 static char *result = NULL; 242 243 if (strchr(argp->ypsetdom_domain, '/')) { 244 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \ 245 rejecting.", argp->ypsetdom_domain); 246 return(NULL); 247 } 248 fromsin = svc_getcaller(transp); 249 250 switch (ypsetmode) { 251 case YPSET_LOCAL: 252 if (fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) { 253 svcerr_noprog(transp); 254 return(NULL); 255 } 256 break; 257 case YPSET_ALL: 258 break; 259 case YPSET_NO: 260 default: 261 svcerr_noprog(transp); 262 return(NULL); 263 } 264 265 if (ntohs(fromsin->sin_port) >= IPPORT_RESERVED) { 266 svcerr_noprog(transp); 267 return(NULL); 268 } 269 270 if (argp->ypsetdom_vers != YPVERS) { 271 svcerr_noprog(transp); 272 return(NULL); 273 } 274 275 bzero((char *)&bindsin, sizeof bindsin); 276 bindsin.sin_family = AF_INET; 277 bindsin.sin_addr.s_addr = *(u_int32_t *)argp->ypsetdom_binding.ypbind_binding_addr; 278 bindsin.sin_port = *(u_short *)argp->ypsetdom_binding.ypbind_binding_port; 279 rpc_received(argp->ypsetdom_domain, &bindsin, 1); 280 281 return((void *) &result); 282 } 283 284 static void 285 ypbindprog_2(struct svc_req *rqstp, register SVCXPRT *transp) 286 { 287 union { 288 domainname ypbindproc_domain_2_arg; 289 struct ypbind_setdom ypbindproc_setdom_2_arg; 290 } argument; 291 struct authunix_parms *creds; 292 char *result; 293 bool_t (*xdr_argument)(), (*xdr_result)(); 294 char *(*local)(); 295 296 switch (rqstp->rq_proc) { 297 case YPBINDPROC_NULL: 298 xdr_argument = xdr_void; 299 xdr_result = xdr_void; 300 local = (char *(*)()) ypbindproc_null_2_yp; 301 break; 302 303 case YPBINDPROC_DOMAIN: 304 xdr_argument = xdr_domainname; 305 xdr_result = xdr_ypbind_resp; 306 local = (char *(*)()) ypbindproc_domain_2_yp; 307 break; 308 309 case YPBINDPROC_SETDOM: 310 switch (rqstp->rq_cred.oa_flavor) { 311 case AUTH_UNIX: 312 creds = (struct authunix_parms *)rqstp->rq_clntcred; 313 if (creds->aup_uid != 0) { 314 svcerr_auth(transp, AUTH_BADCRED); 315 return; 316 } 317 break; 318 default: 319 svcerr_auth(transp, AUTH_TOOWEAK); 320 return; 321 } 322 323 xdr_argument = xdr_ypbind_setdom; 324 xdr_result = xdr_void; 325 local = (char *(*)()) ypbindproc_setdom_2_yp; 326 break; 327 328 default: 329 svcerr_noproc(transp); 330 return; 331 } 332 bzero((char *)&argument, sizeof(argument)); 333 if (!svc_getargs(transp, xdr_argument, (caddr_t)&argument)) { 334 svcerr_decode(transp); 335 return; 336 } 337 result = (*local)(transp, &argument, rqstp); 338 if (result != NULL && !svc_sendreply(transp, xdr_result, result)) { 339 svcerr_systemerr(transp); 340 } 341 return; 342 } 343 344 /* Jack the reaper */ 345 void 346 reaper(int sig) 347 { 348 int st; 349 350 while (wait3(&st, WNOHANG, NULL) > 0) 351 children--; 352 } 353 354 void 355 terminate(int sig) 356 { 357 struct _dom_binding *ypdb; 358 char path[MAXPATHLEN]; 359 360 if (ppid != getpid()) 361 exit(0); 362 363 for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) { 364 close(ypdb->dom_lockfd); 365 if (ypdb->dom_broadcast_pid) 366 kill(ypdb->dom_broadcast_pid, SIGINT); 367 sprintf(path, "%s/%s.%ld", BINDINGDIR, 368 ypdb->dom_domain, ypdb->dom_vers); 369 unlink(path); 370 } 371 close(yplockfd); 372 unlink(YPBINDLOCK); 373 pmap_unset(YPBINDPROG, YPBINDVERS); 374 exit(0); 375 } 376 377 int 378 main(int argc, char *argv[]) 379 { 380 struct timeval tv; 381 int i; 382 DIR *dird; 383 struct dirent *dirp; 384 struct _dom_binding *ypdb, *next; 385 386 /* Check that another ypbind isn't already running. */ 387 if ((yplockfd = (open(YPBINDLOCK, O_RDONLY|O_CREAT, 0444))) == -1) 388 err(1, "%s", YPBINDLOCK); 389 390 if (flock(yplockfd, LOCK_EX|LOCK_NB) == -1 && errno == EWOULDBLOCK) 391 errx(1, "another ypbind is already running. Aborting"); 392 393 /* XXX domainname will be overriden if we use restricted mode */ 394 yp_get_default_domain(&domain_name); 395 if (domain_name[0] == '\0') 396 errx(1, "domainname not set. Aborting"); 397 398 for (i = 1; i<argc; i++) { 399 if (strcmp("-ypset", argv[i]) == 0) 400 ypsetmode = YPSET_ALL; 401 else if (strcmp("-ypsetme", argv[i]) == 0) 402 ypsetmode = YPSET_LOCAL; 403 else if (strcmp("-s", argv[i]) == 0) 404 ypsecuremode++; 405 else if (strcmp("-S", argv[i]) == 0 && argc > i) 406 yp_restricted_mode(argv[++i]); 407 else if (strcmp("-m", argv[i]) == 0) 408 yp_manycast++; 409 else 410 errx(1, "unknown option: %s", argv[i]); 411 } 412 413 /* blow away everything in BINDINGDIR (if it exists) */ 414 415 if ((dird = opendir(BINDINGDIR)) != NULL) { 416 char path[MAXPATHLEN]; 417 while ((dirp = readdir(dird)) != NULL) 418 if (strcmp(dirp->d_name, ".") && 419 strcmp(dirp->d_name, "..")) { 420 sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name); 421 unlink(path); 422 } 423 closedir(dird); 424 } 425 426 #ifdef DAEMON 427 if (daemon(0,0)) 428 err(1, "fork"); 429 #endif 430 431 pmap_unset(YPBINDPROG, YPBINDVERS); 432 433 udptransp = svcudp_create(RPC_ANYSOCK); 434 if (udptransp == NULL) 435 errx(1, "cannot create udp service"); 436 if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2, 437 IPPROTO_UDP)) 438 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)"); 439 440 tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0); 441 if (tcptransp == NULL) 442 errx(1, "cannot create tcp service"); 443 444 if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2, 445 IPPROTO_TCP)) 446 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)"); 447 448 /* build initial domain binding, make it "unsuccessful" */ 449 ypbindlist = (struct _dom_binding *)malloc(sizeof *ypbindlist); 450 if (ypbindlist == NULL) 451 errx(1, "malloc"); 452 bzero((char *)ypbindlist, sizeof *ypbindlist); 453 strncpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain); 454 ypbindlist->dom_vers = YPVERS; 455 ypbindlist->dom_alive = 0; 456 ypbindlist->dom_lockfd = -1; 457 ypbindlist->dom_default = 1; 458 domains++; 459 460 signal(SIGCHLD, reaper); 461 signal(SIGTERM, terminate); 462 463 ppid = getpid(); /* Remember who we are. */ 464 465 openlog(argv[0], LOG_PID, LOG_DAEMON); 466 467 /* Kick off the default domain */ 468 broadcast(ypbindlist); 469 470 while (1) { 471 fdsr = svc_fdset; 472 473 tv.tv_sec = 60; 474 tv.tv_usec = 0; 475 476 switch (select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) { 477 case 0: 478 checkwork(); 479 break; 480 case -1: 481 if (errno != EINTR) 482 syslog(LOG_WARNING, "select: %m"); 483 break; 484 default: 485 for (ypdb = ypbindlist; ypdb; ypdb = next) { 486 next = ypdb->dom_pnext; 487 if (READFD > 0 && FD_ISSET(READFD, &fdsr)) { 488 handle_children(ypdb); 489 if (children == (MAX_CHILDREN - 1)) 490 checkwork(); 491 } 492 } 493 svc_getreqset(&fdsr); 494 break; 495 } 496 } 497 498 /* NOTREACHED */ 499 exit(1); 500 } 501 502 void 503 checkwork(void) 504 { 505 struct _dom_binding *ypdb; 506 507 for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) 508 ping(ypdb); 509 } 510 511 /* The clnt_broadcast() callback mechanism sucks. */ 512 513 /* 514 * Receive results from broadcaster. Don't worry about passing 515 * bogus info to rpc_received() -- it can handle it. Note that we 516 * must be sure to invalidate the dom_pipe_fds descriptors here: 517 * since descriptors can be re-used, we have to make sure we 518 * don't mistake one of the RPC descriptors for one of the pipes. 519 * What's weird is that forgetting to invalidate the pipe descriptors 520 * doesn't always result in an error (otherwise I would have caught 521 * the mistake much sooner), even though logically it should. 522 */ 523 void 524 handle_children(struct _dom_binding *ypdb) 525 { 526 char buf[YPMAXDOMAIN + 1]; 527 struct sockaddr_in addr; 528 int d = 0, a = 0; 529 struct _dom_binding *y, *prev = NULL; 530 char path[MAXPATHLEN]; 531 532 if ((d = read(READFD, &buf, sizeof(buf))) <= 0) 533 syslog(LOG_WARNING, "could not read from child: %m"); 534 535 if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0) 536 syslog(LOG_WARNING, "could not read from child: %m"); 537 538 close(READFD); 539 FD_CLR(READFD, &fdsr); 540 FD_CLR(READFD, &svc_fdset); 541 READFD = WRITEFD = -1; 542 if (d > 0 && a > 0) 543 rpc_received((char *)&buf, &addr, 0); 544 else { 545 for (y = ypbindlist; y; y = y->dom_pnext) { 546 if (y == ypdb) 547 break; 548 prev = y; 549 } 550 switch (ypdb->dom_default) { 551 case 0: 552 if (prev == NULL) 553 ypbindlist = y->dom_pnext; 554 else 555 prev->dom_pnext = y->dom_pnext; 556 sprintf(path, "%s/%s.%ld", BINDINGDIR, 557 ypdb->dom_domain, YPVERS); 558 close(ypdb->dom_lockfd); 559 unlink(path); 560 free(ypdb); 561 domains--; 562 return; 563 case 1: 564 ypdb->dom_broadcast_pid = 0; 565 ypdb->dom_alive = 0; 566 broadcast(ypdb); 567 return; 568 default: 569 break; 570 } 571 } 572 573 return; 574 } 575 576 /* 577 * Send our dying words back to our parent before we perish. 578 */ 579 int 580 tell_parent(char *dom, struct sockaddr_in *addr) 581 { 582 char buf[YPMAXDOMAIN + 1]; 583 struct timeval timeout; 584 fd_set fds; 585 586 timeout.tv_sec = 5; 587 timeout.tv_usec = 0; 588 589 sprintf(buf, "%s", broad_domain->dom_domain); 590 if (write(BROADFD, &buf, sizeof(buf)) < 0) 591 return(1); 592 593 /* 594 * Stay in sync with parent: wait for it to read our first 595 * message before sending the second. 596 */ 597 598 FD_ZERO(&fds); 599 FD_SET(BROADFD, &fds); 600 if (select(FD_SETSIZE, NULL, &fds, NULL, &timeout) == -1) 601 return(1); 602 if (FD_ISSET(BROADFD, &fds)) { 603 if (write(BROADFD, addr, sizeof(struct sockaddr_in)) < 0) 604 return(1); 605 } else { 606 return(1); 607 } 608 609 close(BROADFD); 610 return (0); 611 } 612 613 bool_t broadcast_result(out, addr) 614 bool_t *out; 615 struct sockaddr_in *addr; 616 { 617 if (retries >= MAX_RETRIES) { 618 bzero((char *)addr, sizeof(struct sockaddr_in)); 619 if (tell_parent(broad_domain->dom_domain, addr)) 620 syslog(LOG_WARNING, "lost connection to parent"); 621 return (TRUE); 622 } 623 624 if (yp_restricted && verify(addr->sin_addr)) { 625 retries++; 626 syslog(LOG_NOTICE, "NIS server at %s not in restricted mode access list -- rejecting.\n",inet_ntoa(addr->sin_addr)); 627 return (FALSE); 628 } else { 629 if (tell_parent(broad_domain->dom_domain, addr)) 630 syslog(LOG_WARNING, "lost connection to parent"); 631 return (TRUE); 632 } 633 } 634 635 /* 636 * The right way to send RPC broadcasts. 637 * Use the clnt_broadcast() RPC service. Unfortunately, clnt_broadcast() 638 * blocks while waiting for replies, so we have to fork off separate 639 * broadcaster processes that do the waiting and then transmit their 640 * results back to the parent for processing. We also have to remember 641 * to save the name of the domain we're trying to bind in a global 642 * variable since clnt_broadcast() provides no way to pass things to 643 * the 'eachresult' callback function. 644 */ 645 void 646 broadcast(struct _dom_binding *ypdb) 647 { 648 bool_t out = FALSE; 649 enum clnt_stat stat; 650 651 if (children >= MAX_CHILDREN || ypdb->dom_broadcast_pid) 652 return; 653 654 if (pipe(ypdb->dom_pipe_fds) < 0) { 655 syslog(LOG_WARNING, "pipe: %m"); 656 return; 657 } 658 659 if (ypdb->dom_vers == -1 && (long)ypdb->dom_server_addr.sin_addr.s_addr) 660 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding", 661 inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain); 662 663 broad_domain = ypdb; 664 flock(ypdb->dom_lockfd, LOCK_UN); 665 666 switch ((ypdb->dom_broadcast_pid = fork())) { 667 case 0: 668 close(READFD); 669 signal(SIGCHLD, SIG_DFL); 670 signal(SIGTERM, SIG_DFL); 671 break; 672 case -1: 673 syslog(LOG_WARNING, "fork: %m"); 674 close(READFD); 675 close(WRITEFD); 676 return; 677 default: 678 close(WRITEFD); 679 FD_SET(READFD, &svc_fdset); 680 children++; 681 return; 682 } 683 684 /* Release all locks before doing anything else. */ 685 while (ypbindlist) { 686 close(ypbindlist->dom_lockfd); 687 ypbindlist = ypbindlist->dom_pnext; 688 } 689 close(yplockfd); 690 691 /* 692 * Special 'many-cast' behavior. If we're in restricted mode, 693 * we have a list of possible server addresses to try. What 694 * we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK 695 * procedure and time the replies. Whoever replies fastest 696 * gets to be our server. Note that this is not a broadcast 697 * operation: we transmit uni-cast datagrams only. 698 */ 699 if (yp_restricted && yp_manycast) { 700 short port; 701 int i; 702 struct sockaddr_in sin; 703 704 i = __yp_ping(restricted_addrs, yp_restricted, 705 ypdb->dom_domain, &port); 706 if (i == -1) { 707 bzero((char *)&ypdb->dom_server_addr, 708 sizeof(struct sockaddr_in)); 709 if (tell_parent(ypdb->dom_domain, 710 &ypdb->dom_server_addr)) 711 syslog(LOG_WARNING, "lost connection to parent"); 712 } else { 713 bzero((char *)&sin, sizeof(struct sockaddr_in)); 714 bcopy((char *)&restricted_addrs[i], 715 (char *)&sin.sin_addr, sizeof(struct in_addr)); 716 sin.sin_family = AF_INET; 717 sin.sin_port = port; 718 if (tell_parent(broad_domain->dom_domain, &sin)) 719 syslog(LOG_WARNING, 720 "lost connection to parent"); 721 } 722 _exit(0); 723 } 724 725 retries = 0; 726 727 { 728 char *ptr; 729 730 ptr = (char *)&ypdb->dom_domain; 731 stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK, 732 xdr_domainname, (char *)&ptr, xdr_bool, (char *)&out, 733 (resultproc_t)broadcast_result); 734 } 735 736 if (stat != RPC_SUCCESS) { 737 bzero((char *)&ypdb->dom_server_addr, 738 sizeof(struct sockaddr_in)); 739 if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr)) 740 syslog(LOG_WARNING, "lost connection to parent"); 741 } 742 743 _exit(0); 744 } 745 746 /* 747 * The right way to check if a server is alive. 748 * Attempt to get a client handle pointing to the server and send a 749 * YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE, 750 * we invalidate this binding entry and send out a broadcast to try to 751 * establish a new binding. Note that we treat non-default domains 752 * specially: once bound, we keep tabs on our server, but if it 753 * goes away and fails to respond after one round of broadcasting, we 754 * abandon it until a client specifically references it again. We make 755 * every effort to keep our default domain bound, however, since we 756 * need it to keep the system on its feet. 757 */ 758 int 759 ping(struct _dom_binding *ypdb) 760 { 761 bool_t out; 762 struct timeval interval, timeout; 763 enum clnt_stat stat; 764 int rpcsock = RPC_ANYSOCK; 765 CLIENT *client_handle; 766 767 interval.tv_sec = FAIL_THRESHOLD; 768 interval.tv_usec = 0; 769 timeout.tv_sec = FAIL_THRESHOLD; 770 timeout.tv_usec = 0; 771 772 if (ypdb->dom_broadcast_pid) 773 return(1); 774 775 if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr, 776 YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE, 777 RPCSMALLMSGSIZE)) == (CLIENT *)NULL) { 778 /* Can't get a handle: we're dead. */ 779 ypdb->dom_alive = 0; 780 ypdb->dom_vers = -1; 781 broadcast(ypdb); 782 return(1); 783 } 784 785 { 786 char *ptr; 787 788 ptr = (char *)&ypdb->dom_domain; 789 790 if ((stat = clnt_call(client_handle, YPPROC_DOMAIN, 791 xdr_domainname, (char *)&ptr, xdr_bool, (char *)&out, 792 timeout)) != 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((char *)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((char *)raddrp, (char *)&ypdb->dom_server_addr, 894 sizeof ypdb->dom_server_addr); 895 896 ypdb->dom_vers = YPVERS; 897 ypdb->dom_alive = 1; 898 ypdb->dom_broadcast_pid = 0; 899 900 if (ypdb->dom_lockfd != -1) 901 close(ypdb->dom_lockfd); 902 903 sprintf(path, "%s/%s.%ld", BINDINGDIR, 904 ypdb->dom_domain, ypdb->dom_vers); 905 #ifdef O_SHLOCK 906 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) { 907 (void)mkdir(BINDINGDIR, 0755); 908 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) 909 return; 910 } 911 #else 912 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) { 913 (void)mkdir(BINDINGDIR, 0755); 914 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) 915 return; 916 } 917 flock(fd, LOCK_SH); 918 #endif 919 920 /* 921 * ok, if BINDINGDIR exists, and we can create the binding file, 922 * then write to it.. 923 */ 924 ypdb->dom_lockfd = fd; 925 926 iov[0].iov_base = (caddr_t)&(udptransp->xp_port); 927 iov[0].iov_len = sizeof udptransp->xp_port; 928 iov[1].iov_base = (caddr_t)&ybr; 929 iov[1].iov_len = sizeof ybr; 930 931 bzero(&ybr, sizeof ybr); 932 ybr.ypbind_status = YPBIND_SUCC_VAL; 933 *(u_int32_t *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = raddrp->sin_addr.s_addr; 934 *(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = raddrp->sin_port; 935 936 if (writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) { 937 syslog(LOG_WARNING, "write: %m"); 938 close(ypdb->dom_lockfd); 939 ypdb->dom_lockfd = -1; 940 return; 941 } 942 } 943 944 /* 945 * Check address against list of allowed servers. Return 0 if okay, 946 * 1 if not matched. 947 */ 948 int 949 verify(struct in_addr addr) 950 { 951 int i; 952 953 for (i = 0; i < RESTRICTED_SERVERS; i++) 954 if (!bcmp((char *)&addr, (char *)&restricted_addrs[i], 955 sizeof(struct in_addr))) 956 return(0); 957 958 return(1); 959 } 960 961 /* 962 * Try to set restricted mode. We default to normal mode if we can't 963 * resolve the specified hostnames. 964 */ 965 void 966 yp_restricted_mode(char *args) 967 { 968 struct hostent *h; 969 int i = 0; 970 char *s; 971 972 /* Find the restricted domain. */ 973 if ((s = strsep(&args, ",")) == NULL) 974 return; 975 domain_name = s; 976 977 /* Get the addresses of the servers. */ 978 while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) { 979 if ((h = gethostbyname(s)) == NULL) 980 return; 981 bcopy ((char *)h->h_addr_list[0], (char *)&restricted_addrs[i], 982 sizeof(struct in_addr)); 983 i++; 984 } 985 986 /* ypset and ypsetme not allowed with restricted mode */ 987 ypsetmode = YPSET_NO; 988 989 yp_restricted = i; 990 return; 991 } 992