ypbind.c revision 300268
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: stable/10/usr.sbin/ypbind/ypbind.c 300268 2016-05-20 06:19:00Z truckman $"); 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 76struct _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 92extern bool_t xdr_domainname(), xdr_ypbind_resp(); 93extern bool_t xdr_ypreq_key(), xdr_ypresp_val(); 94extern bool_t xdr_ypbind_setdom(); 95 96void checkwork(void); 97void *ypbindproc_null_2_yp(SVCXPRT *, void *, CLIENT *); 98void *ypbindproc_setdom_2_yp(SVCXPRT *, struct ypbind_setdom *, CLIENT *); 99void rpc_received(char *, struct sockaddr_in *, int); 100void broadcast(struct _dom_binding *); 101int ping(struct _dom_binding *); 102int tell_parent(char *, struct sockaddr_in *); 103void handle_children(struct _dom_binding *); 104void reaper(int); 105void terminate(int); 106void yp_restricted_mode(char *); 107int verify(struct in_addr); 108 109char *domain_name; 110struct _dom_binding *ypbindlist; 111static struct _dom_binding *broad_domain; 112 113#define YPSET_NO 0 114#define YPSET_LOCAL 1 115#define YPSET_ALL 2 116int ypsetmode = YPSET_NO; 117int ypsecuremode = 0; 118int ppid; 119 120#define NOT_RESPONDING_HYSTERESIS 10 121static 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 129int yp_restricted = 0; 130int yp_manycast = 0; 131struct 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 151int retries = 0; 152int children = 0; 153int domains = 0; 154int yplockfd; 155fd_set fdsr; 156 157SVCXPRT *udptransp, *tcptransp; 158 159void * 160ypbindproc_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 168struct ypbind_resp * 169ypbindproc_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 -- \ 181rejecting.", *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 *(u_int32_t *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = 234 ypdb->dom_server_addr.sin_addr.s_addr; 235 *(u_short *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = 236 ypdb->dom_server_addr.sin_port; 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 243void * 244ypbindproc_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 -- \ 251rejecting.", 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 bindsin.sin_addr.s_addr = *(u_int32_t *)argp->ypsetdom_binding.ypbind_binding_addr; 284 bindsin.sin_port = *(u_short *)argp->ypsetdom_binding.ypbind_binding_port; 285 rpc_received(argp->ypsetdom_domain, &bindsin, 1); 286 287 return((void *) &result); 288} 289 290void 291ypbindprog_2(struct svc_req *rqstp, register SVCXPRT *transp) 292{ 293 union { 294 domainname ypbindproc_domain_2_arg; 295 struct ypbind_setdom ypbindproc_setdom_2_arg; 296 } argument; 297 struct authunix_parms *creds; 298 char *result; 299 bool_t (*xdr_argument)(), (*xdr_result)(); 300 char *(*local)(); 301 302 switch (rqstp->rq_proc) { 303 case YPBINDPROC_NULL: 304 xdr_argument = xdr_void; 305 xdr_result = xdr_void; 306 local = (char *(*)()) ypbindproc_null_2_yp; 307 break; 308 309 case YPBINDPROC_DOMAIN: 310 xdr_argument = xdr_domainname; 311 xdr_result = xdr_ypbind_resp; 312 local = (char *(*)()) ypbindproc_domain_2_yp; 313 break; 314 315 case YPBINDPROC_SETDOM: 316 switch (rqstp->rq_cred.oa_flavor) { 317 case AUTH_UNIX: 318 creds = (struct authunix_parms *)rqstp->rq_clntcred; 319 if (creds->aup_uid != 0) { 320 svcerr_auth(transp, AUTH_BADCRED); 321 return; 322 } 323 break; 324 default: 325 svcerr_auth(transp, AUTH_TOOWEAK); 326 return; 327 } 328 329 xdr_argument = xdr_ypbind_setdom; 330 xdr_result = xdr_void; 331 local = (char *(*)()) ypbindproc_setdom_2_yp; 332 break; 333 334 default: 335 svcerr_noproc(transp); 336 return; 337 } 338 bzero(&argument, sizeof(argument)); 339 if (!svc_getargs(transp, (xdrproc_t)xdr_argument, &argument)) { 340 svcerr_decode(transp); 341 return; 342 } 343 result = (*local)(transp, &argument, rqstp); 344 if (result != NULL && 345 !svc_sendreply(transp, (xdrproc_t)xdr_result, result)) { 346 svcerr_systemerr(transp); 347 } 348 return; 349} 350 351/* Jack the reaper */ 352void 353reaper(int sig) 354{ 355 int st; 356 357 while (wait3(&st, WNOHANG, NULL) > 0) 358 children--; 359} 360 361void 362terminate(int sig) 363{ 364 struct _dom_binding *ypdb; 365 char path[MAXPATHLEN]; 366 367 if (ppid != getpid()) 368 exit(0); 369 370 for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) { 371 close(ypdb->dom_lockfd); 372 if (ypdb->dom_broadcast_pid) 373 kill(ypdb->dom_broadcast_pid, SIGINT); 374 sprintf(path, "%s/%s.%ld", BINDINGDIR, 375 ypdb->dom_domain, ypdb->dom_vers); 376 unlink(path); 377 } 378 close(yplockfd); 379 unlink(YPBINDLOCK); 380 pmap_unset(YPBINDPROG, YPBINDVERS); 381 exit(0); 382} 383 384int 385main(int argc, char *argv[]) 386{ 387 struct timeval tv; 388 int i; 389 DIR *dird; 390 struct dirent *dirp; 391 struct _dom_binding *ypdb, *next; 392 393 /* Check that another ypbind isn't already running. */ 394 if ((yplockfd = (open(YPBINDLOCK, O_RDONLY|O_CREAT, 0444))) == -1) 395 err(1, "%s", YPBINDLOCK); 396 397 if (flock(yplockfd, LOCK_EX|LOCK_NB) == -1 && errno == EWOULDBLOCK) 398 errx(1, "another ypbind is already running. Aborting"); 399 400 /* XXX domainname will be overridden if we use restricted mode */ 401 yp_get_default_domain(&domain_name); 402 if (domain_name[0] == '\0') 403 errx(1, "domainname not set. Aborting"); 404 405 for (i = 1; i<argc; i++) { 406 if (strcmp("-ypset", argv[i]) == 0) 407 ypsetmode = YPSET_ALL; 408 else if (strcmp("-ypsetme", argv[i]) == 0) 409 ypsetmode = YPSET_LOCAL; 410 else if (strcmp("-s", argv[i]) == 0) 411 ypsecuremode++; 412 else if (strcmp("-S", argv[i]) == 0 && argc > i) 413 yp_restricted_mode(argv[++i]); 414 else if (strcmp("-m", argv[i]) == 0) 415 yp_manycast++; 416 else 417 errx(1, "unknown option: %s", argv[i]); 418 } 419 420 if (strlen(domain_name) > YPMAXDOMAIN) 421 warnx("truncating domain name %s", domain_name); 422 423 /* blow away everything in BINDINGDIR (if it exists) */ 424 425 if ((dird = opendir(BINDINGDIR)) != NULL) { 426 char path[MAXPATHLEN]; 427 while ((dirp = readdir(dird)) != NULL) 428 if (strcmp(dirp->d_name, ".") && 429 strcmp(dirp->d_name, "..")) { 430 sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name); 431 unlink(path); 432 } 433 closedir(dird); 434 } 435 436#ifdef DAEMON 437 if (daemon(0,0)) 438 err(1, "fork"); 439#endif 440 441 pmap_unset(YPBINDPROG, YPBINDVERS); 442 443 udptransp = svcudp_create(RPC_ANYSOCK); 444 if (udptransp == NULL) 445 errx(1, "cannot create udp service"); 446 if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2, 447 IPPROTO_UDP)) 448 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)"); 449 450 tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0); 451 if (tcptransp == NULL) 452 errx(1, "cannot create tcp service"); 453 454 if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2, 455 IPPROTO_TCP)) 456 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)"); 457 458 /* build initial domain binding, make it "unsuccessful" */ 459 ypbindlist = malloc(sizeof *ypbindlist); 460 if (ypbindlist == NULL) 461 errx(1, "malloc"); 462 bzero(ypbindlist, sizeof *ypbindlist); 463 strlcpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain); 464 ypbindlist->dom_vers = YPVERS; 465 ypbindlist->dom_alive = 0; 466 ypbindlist->dom_lockfd = -1; 467 ypbindlist->dom_default = 1; 468 domains++; 469 470 signal(SIGCHLD, reaper); 471 signal(SIGTERM, terminate); 472 473 ppid = getpid(); /* Remember who we are. */ 474 475 openlog(argv[0], LOG_PID, LOG_DAEMON); 476 477 if (madvise(NULL, 0, MADV_PROTECT) != 0) 478 syslog(LOG_WARNING, "madvise(): %m"); 479 480 /* Kick off the default domain */ 481 broadcast(ypbindlist); 482 483 while (1) { 484 fdsr = svc_fdset; 485 486 tv.tv_sec = 60; 487 tv.tv_usec = 0; 488 489 switch (select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) { 490 case 0: 491 checkwork(); 492 break; 493 case -1: 494 if (errno != EINTR) 495 syslog(LOG_WARNING, "select: %m"); 496 break; 497 default: 498 for (ypdb = ypbindlist; ypdb; ypdb = next) { 499 next = ypdb->dom_pnext; 500 if (READFD > 0 && FD_ISSET(READFD, &fdsr)) { 501 handle_children(ypdb); 502 if (children == (MAX_CHILDREN - 1)) 503 checkwork(); 504 } 505 } 506 svc_getreqset(&fdsr); 507 break; 508 } 509 } 510 511 /* NOTREACHED */ 512 exit(1); 513} 514 515void 516checkwork(void) 517{ 518 struct _dom_binding *ypdb; 519 520 for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) 521 ping(ypdb); 522} 523 524/* The clnt_broadcast() callback mechanism sucks. */ 525 526/* 527 * Receive results from broadcaster. Don't worry about passing 528 * bogus info to rpc_received() -- it can handle it. Note that we 529 * must be sure to invalidate the dom_pipe_fds descriptors here: 530 * since descriptors can be re-used, we have to make sure we 531 * don't mistake one of the RPC descriptors for one of the pipes. 532 * What's weird is that forgetting to invalidate the pipe descriptors 533 * doesn't always result in an error (otherwise I would have caught 534 * the mistake much sooner), even though logically it should. 535 */ 536void 537handle_children(struct _dom_binding *ypdb) 538{ 539 char buf[YPMAXDOMAIN + 1]; 540 struct sockaddr_in addr; 541 int d = 0, a = 0; 542 struct _dom_binding *y, *prev = NULL; 543 char path[MAXPATHLEN]; 544 545 if ((d = read(READFD, &buf, sizeof(buf))) <= 0) 546 syslog(LOG_WARNING, "could not read from child: %m"); 547 548 if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0) 549 syslog(LOG_WARNING, "could not read from child: %m"); 550 551 close(READFD); 552 FD_CLR(READFD, &fdsr); 553 FD_CLR(READFD, &svc_fdset); 554 READFD = WRITEFD = -1; 555 if (d > 0 && a > 0) 556 rpc_received(buf, &addr, 0); 557 else { 558 for (y = ypbindlist; y; y = y->dom_pnext) { 559 if (y == ypdb) 560 break; 561 prev = y; 562 } 563 switch (ypdb->dom_default) { 564 case 0: 565 if (prev == NULL) 566 ypbindlist = y->dom_pnext; 567 else 568 prev->dom_pnext = y->dom_pnext; 569 sprintf(path, "%s/%s.%ld", BINDINGDIR, 570 ypdb->dom_domain, YPVERS); 571 close(ypdb->dom_lockfd); 572 unlink(path); 573 free(ypdb); 574 domains--; 575 return; 576 case 1: 577 ypdb->dom_broadcast_pid = 0; 578 ypdb->dom_alive = 0; 579 broadcast(ypdb); 580 return; 581 default: 582 break; 583 } 584 } 585 586 return; 587} 588 589/* 590 * Send our dying words back to our parent before we perish. 591 */ 592int 593tell_parent(char *dom, struct sockaddr_in *addr) 594{ 595 char buf[YPMAXDOMAIN + 1]; 596 struct timeval timeout; 597 fd_set fds; 598 599 timeout.tv_sec = 5; 600 timeout.tv_usec = 0; 601 602 sprintf(buf, "%s", broad_domain->dom_domain); 603 if (write(BROADFD, &buf, sizeof(buf)) < 0) 604 return(1); 605 606 /* 607 * Stay in sync with parent: wait for it to read our first 608 * message before sending the second. 609 */ 610 611 FD_ZERO(&fds); 612 FD_SET(BROADFD, &fds); 613 if (select(FD_SETSIZE, NULL, &fds, NULL, &timeout) == -1) 614 return(1); 615 if (FD_ISSET(BROADFD, &fds)) { 616 if (write(BROADFD, addr, sizeof(struct sockaddr_in)) < 0) 617 return(1); 618 } else { 619 return(1); 620 } 621 622 close(BROADFD); 623 return (0); 624} 625 626bool_t broadcast_result(out, addr) 627bool_t *out; 628struct sockaddr_in *addr; 629{ 630 if (retries >= MAX_RETRIES) { 631 bzero(addr, sizeof(struct sockaddr_in)); 632 if (tell_parent(broad_domain->dom_domain, addr)) 633 syslog(LOG_WARNING, "lost connection to parent"); 634 return (TRUE); 635 } 636 637 if (yp_restricted && verify(addr->sin_addr)) { 638 retries++; 639 syslog(LOG_NOTICE, "NIS server at %s not in restricted mode access list -- rejecting.\n",inet_ntoa(addr->sin_addr)); 640 return (FALSE); 641 } else { 642 if (tell_parent(broad_domain->dom_domain, addr)) 643 syslog(LOG_WARNING, "lost connection to parent"); 644 return (TRUE); 645 } 646} 647 648/* 649 * The right way to send RPC broadcasts. 650 * Use the clnt_broadcast() RPC service. Unfortunately, clnt_broadcast() 651 * blocks while waiting for replies, so we have to fork off separate 652 * broadcaster processes that do the waiting and then transmit their 653 * results back to the parent for processing. We also have to remember 654 * to save the name of the domain we're trying to bind in a global 655 * variable since clnt_broadcast() provides no way to pass things to 656 * the 'eachresult' callback function. 657 */ 658void 659broadcast(struct _dom_binding *ypdb) 660{ 661 bool_t out = FALSE; 662 enum clnt_stat stat; 663 664 if (children >= MAX_CHILDREN || ypdb->dom_broadcast_pid) 665 return; 666 667 if (pipe(ypdb->dom_pipe_fds) < 0) { 668 syslog(LOG_WARNING, "pipe: %m"); 669 return; 670 } 671 672 if (ypdb->dom_vers == -1 && (long)ypdb->dom_server_addr.sin_addr.s_addr) { 673 if (not_responding_count++ >= NOT_RESPONDING_HYSTERESIS) { 674 not_responding_count = NOT_RESPONDING_HYSTERESIS; 675 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding", 676 inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain); 677 } 678 } 679 680 broad_domain = ypdb; 681 flock(ypdb->dom_lockfd, LOCK_UN); 682 683 switch ((ypdb->dom_broadcast_pid = fork())) { 684 case 0: 685 close(READFD); 686 signal(SIGCHLD, SIG_DFL); 687 signal(SIGTERM, SIG_DFL); 688 break; 689 case -1: 690 syslog(LOG_WARNING, "fork: %m"); 691 close(READFD); 692 close(WRITEFD); 693 return; 694 default: 695 close(WRITEFD); 696 FD_SET(READFD, &svc_fdset); 697 children++; 698 return; 699 } 700 701 /* Release all locks before doing anything else. */ 702 while (ypbindlist) { 703 close(ypbindlist->dom_lockfd); 704 ypbindlist = ypbindlist->dom_pnext; 705 } 706 close(yplockfd); 707 708 /* 709 * Special 'many-cast' behavior. If we're in restricted mode, 710 * we have a list of possible server addresses to try. What 711 * we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK 712 * procedure and time the replies. Whoever replies fastest 713 * gets to be our server. Note that this is not a broadcast 714 * operation: we transmit uni-cast datagrams only. 715 */ 716 if (yp_restricted && yp_manycast) { 717 short port; 718 int i; 719 struct sockaddr_in sin; 720 721 i = __yp_ping(restricted_addrs, yp_restricted, 722 ypdb->dom_domain, &port); 723 if (i == -1) { 724 bzero(&ypdb->dom_server_addr, 725 sizeof(struct sockaddr_in)); 726 if (tell_parent(ypdb->dom_domain, 727 &ypdb->dom_server_addr)) 728 syslog(LOG_WARNING, "lost connection to parent"); 729 } else { 730 bzero(&sin, sizeof(struct sockaddr_in)); 731 bcopy(&restricted_addrs[i], 732 &sin.sin_addr, sizeof(struct in_addr)); 733 sin.sin_family = AF_INET; 734 sin.sin_port = port; 735 if (tell_parent(broad_domain->dom_domain, &sin)) 736 syslog(LOG_WARNING, 737 "lost connection to parent"); 738 } 739 _exit(0); 740 } 741 742 retries = 0; 743 744 { 745 char *ptr; 746 747 ptr = ypdb->dom_domain; 748 stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK, 749 (xdrproc_t)xdr_domainname, &ptr, 750 (xdrproc_t)xdr_bool, &out, 751 (resultproc_t)broadcast_result); 752 } 753 754 if (stat != RPC_SUCCESS) { 755 bzero(&ypdb->dom_server_addr, 756 sizeof(struct sockaddr_in)); 757 if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr)) 758 syslog(LOG_WARNING, "lost connection to parent"); 759 } 760 761 _exit(0); 762} 763 764/* 765 * The right way to check if a server is alive. 766 * Attempt to get a client handle pointing to the server and send a 767 * YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE, 768 * we invalidate this binding entry and send out a broadcast to try to 769 * establish a new binding. Note that we treat non-default domains 770 * specially: once bound, we keep tabs on our server, but if it 771 * goes away and fails to respond after one round of broadcasting, we 772 * abandon it until a client specifically references it again. We make 773 * every effort to keep our default domain bound, however, since we 774 * need it to keep the system on its feet. 775 */ 776int 777ping(struct _dom_binding *ypdb) 778{ 779 bool_t out; 780 struct timeval interval, timeout; 781 enum clnt_stat stat; 782 int rpcsock = RPC_ANYSOCK; 783 CLIENT *client_handle; 784 785 interval.tv_sec = FAIL_THRESHOLD; 786 interval.tv_usec = 0; 787 timeout.tv_sec = FAIL_THRESHOLD; 788 timeout.tv_usec = 0; 789 790 if (ypdb->dom_broadcast_pid) 791 return(1); 792 793 if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr, 794 YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE, 795 RPCSMALLMSGSIZE)) == (CLIENT *)NULL) { 796 /* Can't get a handle: we're dead. */ 797 ypdb->dom_alive = 0; 798 ypdb->dom_vers = -1; 799 broadcast(ypdb); 800 return(1); 801 } 802 803 { 804 char *ptr; 805 806 ptr = ypdb->dom_domain; 807 808 stat = clnt_call(client_handle, YPPROC_DOMAIN, 809 (xdrproc_t)xdr_domainname, &ptr, 810 (xdrproc_t)xdr_bool, &out, timeout); 811 if (stat != RPC_SUCCESS || out == FALSE) { 812 ypdb->dom_alive = 0; 813 ypdb->dom_vers = -1; 814 clnt_destroy(client_handle); 815 broadcast(ypdb); 816 return(1); 817 } 818 } 819 820 clnt_destroy(client_handle); 821 return(0); 822} 823 824void 825rpc_received(char *dom, struct sockaddr_in *raddrp, int force) 826{ 827 struct _dom_binding *ypdb, *prev = NULL; 828 struct iovec iov[2]; 829 struct ypbind_resp ybr; 830 char path[MAXPATHLEN]; 831 int fd; 832 833 /*printf("returned from %s/%d about %s\n", inet_ntoa(raddrp->sin_addr), 834 ntohs(raddrp->sin_port), dom);*/ 835 836 if (dom == NULL) 837 return; 838 839 for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) { 840 if (strcmp(ypdb->dom_domain, dom) == 0) 841 break; 842 prev = ypdb; 843 } 844 845 if (ypdb && force) { 846 if (ypdb->dom_broadcast_pid) { 847 kill(ypdb->dom_broadcast_pid, SIGINT); 848 close(READFD); 849 FD_CLR(READFD, &fdsr); 850 FD_CLR(READFD, &svc_fdset); 851 READFD = WRITEFD = -1; 852 } 853 } 854 855 /* if in secure mode, check originating port number */ 856 if ((ypsecuremode && (ntohs(raddrp->sin_port) >= IPPORT_RESERVED))) { 857 syslog(LOG_WARNING, "Rejected NIS server on [%s/%d] for domain %s.", 858 inet_ntoa(raddrp->sin_addr), ntohs(raddrp->sin_port), 859 dom); 860 if (ypdb != NULL) { 861 ypdb->dom_broadcast_pid = 0; 862 ypdb->dom_alive = 0; 863 } 864 return; 865 } 866 867 if (raddrp->sin_addr.s_addr == (long)0) { 868 switch (ypdb->dom_default) { 869 case 0: 870 if (prev == NULL) 871 ypbindlist = ypdb->dom_pnext; 872 else 873 prev->dom_pnext = ypdb->dom_pnext; 874 sprintf(path, "%s/%s.%ld", BINDINGDIR, 875 ypdb->dom_domain, YPVERS); 876 close(ypdb->dom_lockfd); 877 unlink(path); 878 free(ypdb); 879 domains--; 880 return; 881 case 1: 882 ypdb->dom_broadcast_pid = 0; 883 ypdb->dom_alive = 0; 884 broadcast(ypdb); 885 return; 886 default: 887 break; 888 } 889 } 890 891 if (ypdb == NULL) { 892 if (force == 0) 893 return; 894 if (strlen(dom) > YPMAXDOMAIN) { 895 syslog(LOG_WARNING, "domain %s too long", dom); 896 return; 897 } 898 ypdb = malloc(sizeof *ypdb); 899 if (ypdb == NULL) { 900 syslog(LOG_WARNING, "malloc: %m"); 901 return; 902 } 903 bzero(ypdb, sizeof *ypdb); 904 strlcpy(ypdb->dom_domain, dom, sizeof ypdb->dom_domain); 905 ypdb->dom_lockfd = -1; 906 ypdb->dom_default = 0; 907 ypdb->dom_pnext = ypbindlist; 908 ypbindlist = ypdb; 909 } 910 911 /* We've recovered from a crash: inform the world. */ 912 if (ypdb->dom_vers == -1 && ypdb->dom_server_addr.sin_addr.s_addr) { 913 if (not_responding_count >= NOT_RESPONDING_HYSTERESIS) { 914 not_responding_count = 0; 915 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" OK", 916 inet_ntoa(raddrp->sin_addr), ypdb->dom_domain); 917 } 918 } 919 920 bcopy(raddrp, &ypdb->dom_server_addr, 921 sizeof ypdb->dom_server_addr); 922 923 ypdb->dom_vers = YPVERS; 924 ypdb->dom_alive = 1; 925 ypdb->dom_broadcast_pid = 0; 926 927 if (ypdb->dom_lockfd != -1) 928 close(ypdb->dom_lockfd); 929 930 sprintf(path, "%s/%s.%ld", BINDINGDIR, 931 ypdb->dom_domain, ypdb->dom_vers); 932#ifdef O_SHLOCK 933 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) { 934 (void)mkdir(BINDINGDIR, 0755); 935 if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) 936 return; 937 } 938#else 939 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) { 940 (void)mkdir(BINDINGDIR, 0755); 941 if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) 942 return; 943 } 944 flock(fd, LOCK_SH); 945#endif 946 947 /* 948 * ok, if BINDINGDIR exists, and we can create the binding file, 949 * then write to it.. 950 */ 951 ypdb->dom_lockfd = fd; 952 953 iov[0].iov_base = (char *)&(udptransp->xp_port); 954 iov[0].iov_len = sizeof udptransp->xp_port; 955 iov[1].iov_base = (char *)&ybr; 956 iov[1].iov_len = sizeof ybr; 957 958 bzero(&ybr, sizeof ybr); 959 ybr.ypbind_status = YPBIND_SUCC_VAL; 960 *(u_int32_t *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = raddrp->sin_addr.s_addr; 961 *(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = raddrp->sin_port; 962 963 if (writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) { 964 syslog(LOG_WARNING, "write: %m"); 965 close(ypdb->dom_lockfd); 966 ypdb->dom_lockfd = -1; 967 return; 968 } 969} 970 971/* 972 * Check address against list of allowed servers. Return 0 if okay, 973 * 1 if not matched. 974 */ 975int 976verify(struct in_addr addr) 977{ 978 int i; 979 980 for (i = 0; i < RESTRICTED_SERVERS; i++) 981 if (!bcmp(&addr, &restricted_addrs[i], sizeof(struct in_addr))) 982 return(0); 983 984 return(1); 985} 986 987/* 988 * Try to set restricted mode. We default to normal mode if we can't 989 * resolve the specified hostnames. 990 */ 991void 992yp_restricted_mode(char *args) 993{ 994 struct hostent *h; 995 int i = 0; 996 char *s; 997 998 /* Find the restricted domain. */ 999 if ((s = strsep(&args, ",")) == NULL) 1000 return; 1001 domain_name = s; 1002 1003 /* Get the addresses of the servers. */ 1004 while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) { 1005 if ((h = gethostbyname(s)) == NULL) 1006 return; 1007 bcopy (h->h_addr_list[0], &restricted_addrs[i], 1008 sizeof(struct in_addr)); 1009 i++; 1010 } 1011 1012 /* ypset and ypsetme not allowed with restricted mode */ 1013 ypsetmode = YPSET_NO; 1014 1015 yp_restricted = i; 1016 return; 1017} 1018