ypbind.c revision 43854
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 31static const char rcsid[] = 32 "$Id: ypbind.c,v 1.27 1998/01/19 23:31:38 wpaul Exp $"; 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> 66struct 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 78struct _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 94extern bool_t xdr_domainname(), xdr_ypbind_resp(); 95extern bool_t xdr_ypreq_key(), xdr_ypresp_val(); 96extern bool_t xdr_ypbind_setdom(); 97 98void checkwork __P((void)); 99void *ypbindproc_null_2_yp __P((SVCXPRT *, void *, CLIENT *)); 100void *ypbindproc_setdom_2_yp __P((SVCXPRT *, struct ypbind_setdom *, CLIENT *)); 101void rpc_received __P((char *, struct sockaddr_in *, int )); 102void broadcast __P((struct _dom_binding *)); 103int ping __P((struct _dom_binding *)); 104int tell_parent __P((char *, struct sockaddr_in *)); 105void handle_children __P(( struct _dom_binding * )); 106void reaper __P((int)); 107void terminate __P((int)); 108void yp_restricted_mode __P((char *)); 109int verify __P((struct in_addr)); 110 111char *domain_name; 112struct _dom_binding *ypbindlist; 113static struct _dom_binding *broad_domain; 114 115#define YPSET_NO 0 116#define YPSET_LOCAL 1 117#define YPSET_ALL 2 118int ypsetmode = YPSET_NO; 119int ypsecuremode = 0; 120int 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 128int yp_restricted = 0; 129int yp_manycast = 0; 130struct 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 150int retries = 0; 151int children = 0; 152int domains = 0; 153int yplockfd; 154fd_set fdsr; 155 156SVCXPRT *udptransp, *tcptransp; 157 158void * 159ypbindproc_null_2_yp(transp, argp, clnt) 160SVCXPRT *transp; 161void *argp; 162CLIENT *clnt; 163{ 164 static char res; 165 166 bzero((char *)&res, sizeof(res)); 167 return (void *)&res; 168} 169 170struct ypbind_resp * 171ypbindproc_domain_2_yp(transp, argp, clnt) 172SVCXPRT *transp; 173domainname *argp; 174CLIENT *clnt; 175{ 176 static struct ypbind_resp res; 177 struct _dom_binding *ypdb; 178 char path[MAXPATHLEN]; 179 180 bzero((char *)&res, sizeof res); 181 res.ypbind_status = YPBIND_FAIL_VAL; 182 res.ypbind_resp_u.ypbind_error = YPBIND_ERR_NOSERV; 183 184 if (strchr(*argp, '/')) { 185 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \ 186rejecting.", *argp); 187 return(&res); 188 } 189 190 for(ypdb=ypbindlist; ypdb; ypdb=ypdb->dom_pnext) { 191 if( strcmp(ypdb->dom_domain, *argp) == 0) 192 break; 193 } 194 195 if(ypdb==NULL) { 196 if (yp_restricted) { 197 syslog(LOG_NOTICE, "Running in restricted mode -- request to bind domain \"%s\" rejected.\n", *argp); 198 return &res; 199 } 200 201 if (domains >= MAX_DOMAINS) { 202 syslog(LOG_WARNING, "domain limit (%d) exceeded", 203 MAX_DOMAINS); 204 res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC; 205 return &res; 206 } 207 ypdb = (struct _dom_binding *)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((char *)ypdb, sizeof *ypdb); 214 strncpy(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_long *)&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(transp, argp, clnt) 245SVCXPRT *transp; 246ypbind_setdom *argp; 247CLIENT *clnt; 248{ 249 struct sockaddr_in *fromsin, bindsin; 250 static char *result = NULL; 251 252 if (strchr(argp->ypsetdom_domain, '/')) { 253 syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \ 254rejecting.", argp->ypsetdom_domain); 255 return(NULL); 256 } 257 fromsin = svc_getcaller(transp); 258 259 switch(ypsetmode) { 260 case YPSET_LOCAL: 261 if( fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) { 262 svcerr_noprog(transp); 263 return(NULL); 264 } 265 break; 266 case YPSET_ALL: 267 break; 268 case YPSET_NO: 269 default: 270 svcerr_noprog(transp); 271 return(NULL); 272 } 273 274 if(ntohs(fromsin->sin_port) >= IPPORT_RESERVED) { 275 svcerr_noprog(transp); 276 return(NULL); 277 } 278 279 if(argp->ypsetdom_vers != YPVERS) { 280 svcerr_noprog(transp); 281 return(NULL); 282 } 283 284 bzero((char *)&bindsin, sizeof bindsin); 285 bindsin.sin_family = AF_INET; 286 bindsin.sin_addr.s_addr = *(u_long *)argp->ypsetdom_binding.ypbind_binding_addr; 287 bindsin.sin_port = *(u_short *)argp->ypsetdom_binding.ypbind_binding_port; 288 rpc_received(argp->ypsetdom_domain, &bindsin, 1); 289 290 return((void *) &result); 291} 292 293static void 294ypbindprog_2(rqstp, transp) 295struct svc_req *rqstp; 296register SVCXPRT *transp; 297{ 298 union { 299 domainname ypbindproc_domain_2_arg; 300 struct ypbind_setdom ypbindproc_setdom_2_arg; 301 } argument; 302 struct authunix_parms *creds; 303 char *result; 304 bool_t (*xdr_argument)(), (*xdr_result)(); 305 char *(*local)(); 306 307 switch (rqstp->rq_proc) { 308 case YPBINDPROC_NULL: 309 xdr_argument = xdr_void; 310 xdr_result = xdr_void; 311 local = (char *(*)()) ypbindproc_null_2_yp; 312 break; 313 314 case YPBINDPROC_DOMAIN: 315 xdr_argument = xdr_domainname; 316 xdr_result = xdr_ypbind_resp; 317 local = (char *(*)()) ypbindproc_domain_2_yp; 318 break; 319 320 case YPBINDPROC_SETDOM: 321 switch(rqstp->rq_cred.oa_flavor) { 322 case AUTH_UNIX: 323 creds = (struct authunix_parms *)rqstp->rq_clntcred; 324 if( creds->aup_uid != 0) { 325 svcerr_auth(transp, AUTH_BADCRED); 326 return; 327 } 328 break; 329 default: 330 svcerr_auth(transp, AUTH_TOOWEAK); 331 return; 332 } 333 334 xdr_argument = xdr_ypbind_setdom; 335 xdr_result = xdr_void; 336 local = (char *(*)()) ypbindproc_setdom_2_yp; 337 break; 338 339 default: 340 svcerr_noproc(transp); 341 return; 342 } 343 bzero((char *)&argument, sizeof(argument)); 344 if (!svc_getargs(transp, xdr_argument, (caddr_t)&argument)) { 345 svcerr_decode(transp); 346 return; 347 } 348 result = (*local)(transp, &argument, rqstp); 349 if (result != NULL && !svc_sendreply(transp, xdr_result, result)) { 350 svcerr_systemerr(transp); 351 } 352 return; 353} 354 355/* Jack the reaper */ 356void reaper(sig) 357int sig; 358{ 359 int st; 360 361 while(wait3(&st, WNOHANG, NULL) > 0) 362 children--; 363} 364 365void terminate(sig) 366int 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 388int 389main(argc, argv) 390int argc; 391char **argv; 392{ 393 struct timeval tv; 394 int i; 395 DIR *dird; 396 struct dirent *dirp; 397 struct _dom_binding *ypdb; 398 399 /* Check that another ypbind isn't already running. */ 400 if ((yplockfd = (open(YPBINDLOCK, O_RDONLY|O_CREAT, 0444))) == -1) 401 err(1, "%s", YPBINDLOCK); 402 403 if(flock(yplockfd, LOCK_EX|LOCK_NB) == -1 && errno == EWOULDBLOCK) 404 errx(1, "another ypbind is already running. Aborting"); 405 406 /* XXX domainname will be overriden if we use restricted mode */ 407 yp_get_default_domain(&domain_name); 408 if( domain_name[0] == '\0') 409 errx(1, "domainname not set. Aborting"); 410 411 for(i=1; i<argc; i++) { 412 if( strcmp("-ypset", argv[i]) == 0) 413 ypsetmode = YPSET_ALL; 414 else if (strcmp("-ypsetme", argv[i]) == 0) 415 ypsetmode = YPSET_LOCAL; 416 else if (strcmp("-s", argv[i]) == 0) 417 ypsecuremode++; 418 else if (strcmp("-S", argv[i]) == 0 && argc > i) 419 yp_restricted_mode(argv[i+1]); 420 else if (strcmp("-m", argv[i]) == 0) 421 yp_manycast++; 422 } 423 424 /* blow away everything in BINDINGDIR (if it exists) */ 425 426 if ((dird = opendir(BINDINGDIR)) != NULL) { 427 char path[MAXPATHLEN]; 428 while ((dirp = readdir(dird)) != NULL) 429 if (strcmp(dirp->d_name, ".") && 430 strcmp(dirp->d_name, "..")) { 431 sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name); 432 unlink(path); 433 } 434 closedir(dird); 435 } 436 437#ifdef DAEMON 438 if (daemon(0,0)) 439 err(1, "fork"); 440#endif 441 442 pmap_unset(YPBINDPROG, YPBINDVERS); 443 444 udptransp = svcudp_create(RPC_ANYSOCK); 445 if (udptransp == NULL) 446 errx(1, "cannot create udp service"); 447 if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2, 448 IPPROTO_UDP)) 449 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)"); 450 451 tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0); 452 if (tcptransp == NULL) 453 errx(1, "cannot create tcp service"); 454 455 if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2, 456 IPPROTO_TCP)) 457 errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)"); 458 459 /* build initial domain binding, make it "unsuccessful" */ 460 ypbindlist = (struct _dom_binding *)malloc(sizeof *ypbindlist); 461 if (ypbindlist == NULL) 462 errx(1, "malloc"); 463 bzero((char *)ypbindlist, sizeof *ypbindlist); 464 strncpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain); 465 ypbindlist->dom_vers = YPVERS; 466 ypbindlist->dom_alive = 0; 467 ypbindlist->dom_lockfd = -1; 468 ypbindlist->dom_default = 1; 469 domains++; 470 471 signal(SIGCHLD, reaper); 472 signal(SIGTERM, terminate); 473 474 ppid = getpid(); /* Remember who we are. */ 475 476 openlog(argv[0], LOG_PID, LOG_DAEMON); 477 478 /* Kick off the default domain */ 479 broadcast(ypbindlist); 480 481 while(1) { 482 fdsr = svc_fdset; 483 484 tv.tv_sec = 60; 485 tv.tv_usec = 0; 486 487 switch(select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) { 488 case 0: 489 checkwork(); 490 break; 491 case -1: 492 if (errno != EINTR) 493 syslog(LOG_WARNING, "select: %m"); 494 break; 495 default: 496 for(ypdb=ypbindlist; ypdb; ypdb=ypdb->dom_pnext) { 497 if (READFD > 0 && FD_ISSET(READFD, &fdsr)) { 498 handle_children(ypdb); 499 if (children == (MAX_CHILDREN - 1)) 500 checkwork(); 501 } 502 } 503 svc_getreqset(&fdsr); 504 break; 505 } 506 } 507 508 /* NOTREACHED */ 509 exit(1); 510} 511 512void 513checkwork() 514{ 515 struct _dom_binding *ypdb; 516 517 for(ypdb=ypbindlist; ypdb; ypdb=ypdb->dom_pnext) 518 ping(ypdb); 519} 520 521/* The clnt_broadcast() callback mechanism sucks. */ 522 523/* 524 * Receive results from broadcaster. Don't worry about passing 525 * bogus info to rpc_received() -- it can handle it. Note that we 526 * must be sure to invalidate the dom_pipe_fds descriptors here: 527 * since descriptors can be re-used, we have to make sure we 528 * don't mistake one of the RPC descriptors for one of the pipes. 529 * What's weird is that forgetting to invalidate the pipe descriptors 530 * doesn't always result in an error (otherwise I would have caught 531 * the mistake much sooner), even though logically it should. 532 */ 533void handle_children(ypdb) 534struct _dom_binding *ypdb; 535{ 536 char buf[YPMAXDOMAIN + 1]; 537 struct sockaddr_in addr; 538 int d = 0, a = 0; 539 struct _dom_binding *y, *prev = NULL; 540 char path[MAXPATHLEN]; 541 542 if ((d = read(READFD, &buf, sizeof(buf))) <= 0) 543 syslog(LOG_WARNING, "could not read from child: %m"); 544 545 if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0) 546 syslog(LOG_WARNING, "could not read from child: %m"); 547 548 close(READFD); 549 FD_CLR(READFD, &fdsr); 550 FD_CLR(READFD, &svc_fdset); 551 READFD = WRITEFD = -1; 552 if (d > 0 && a > 0) 553 rpc_received((char *)&buf, &addr, 0); 554 else { 555 for(y=ypbindlist; y; y=y->dom_pnext) { 556 if (y == ypdb) 557 break; 558 prev = y; 559 } 560 switch(ypdb->dom_default) { 561 case 0: 562 if (prev == NULL) 563 ypbindlist = y->dom_pnext; 564 else 565 prev->dom_pnext = y->dom_pnext; 566 sprintf(path, "%s/%s.%ld", BINDINGDIR, 567 ypdb->dom_domain, YPVERS); 568 close(ypdb->dom_lockfd); 569 unlink(path); 570 free(ypdb); 571 domains--; 572 return; 573 case 1: 574 ypdb->dom_broadcast_pid = 0; 575 ypdb->dom_alive = 0; 576 broadcast(ypdb); 577 return; 578 default: 579 break; 580 } 581 } 582 583 return; 584} 585 586/* 587 * Send our dying words back to our parent before we perish. 588 */ 589int 590tell_parent(dom, addr) 591char *dom; 592struct sockaddr_in *addr; 593{ 594 char buf[YPMAXDOMAIN + 1]; 595 struct timeval timeout; 596 fd_set fds; 597 598 timeout.tv_sec = 5; 599 timeout.tv_usec = 0; 600 601 sprintf(buf, "%s", broad_domain->dom_domain); 602 if (write(BROADFD, &buf, sizeof(buf)) < 0) 603 return(1); 604 605 /* 606 * Stay in sync with parent: wait for it to read our first 607 * message before sending the second. 608 */ 609 610 FD_ZERO(&fds); 611 FD_SET(BROADFD, &fds); 612 if (select(FD_SETSIZE, NULL, &fds, NULL, &timeout) == -1) 613 return(1); 614 if (FD_ISSET(BROADFD, &fds)) { 615 if (write(BROADFD, addr, sizeof(struct sockaddr_in)) < 0) 616 return(1); 617 } else { 618 return(1); 619 } 620 621 close(BROADFD); 622 return (0); 623} 624 625bool_t broadcast_result(out, addr) 626bool_t *out; 627struct sockaddr_in *addr; 628{ 629 if (retries >= MAX_RETRIES) { 630 bzero((char *)addr, sizeof(struct sockaddr_in)); 631 if (tell_parent(broad_domain->dom_domain, addr)) 632 syslog(LOG_WARNING, "lost connection to parent"); 633 return TRUE; 634 } 635 636 if (yp_restricted && verify(addr->sin_addr)) { 637 retries++; 638 syslog(LOG_NOTICE, "NIS server at %s not in restricted mode access list -- rejecting.\n",inet_ntoa(addr->sin_addr)); 639 return FALSE; 640 } else { 641 if (tell_parent(broad_domain->dom_domain, addr)) 642 syslog(LOG_WARNING, "lost connection to parent"); 643 return TRUE; 644 } 645} 646 647/* 648 * The right way to send RPC broadcasts. 649 * Use the clnt_broadcast() RPC service. Unfortunately, clnt_broadcast() 650 * blocks while waiting for replies, so we have to fork off seperate 651 * broadcaster processes that do the waiting and then transmit their 652 * results back to the parent for processing. We also have to remember 653 * to save the name of the domain we're trying to bind in a global 654 * variable since clnt_broadcast() provides no way to pass things to 655 * the 'eachresult' callback function. 656 */ 657void 658broadcast(ypdb) 659struct _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 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding", 674 inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain); 675 676 broad_domain = ypdb; 677 flock(ypdb->dom_lockfd, LOCK_UN); 678 679 switch((ypdb->dom_broadcast_pid = fork())) { 680 case 0: 681 close(READFD); 682 signal(SIGCHLD, SIG_DFL); 683 signal(SIGTERM, SIG_DFL); 684 break; 685 case -1: 686 syslog(LOG_WARNING, "fork: %m"); 687 close(READFD); 688 close(WRITEFD); 689 return; 690 default: 691 close(WRITEFD); 692 FD_SET(READFD, &svc_fdset); 693 children++; 694 return; 695 } 696 697 /* Release all locks before doing anything else. */ 698 while(ypbindlist) { 699 close(ypbindlist->dom_lockfd); 700 ypbindlist = ypbindlist->dom_pnext; 701 } 702 close(yplockfd); 703 704 /* 705 * Special 'many-cast' behavior. If we're in restricted mode, 706 * we have a list of possible server addresses to try. What 707 * we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK 708 * procedure and time the replies. Whoever replies fastest 709 * gets to be our server. Note that this is not a broadcast 710 * operation: we transmit uni-cast datagrams only. 711 */ 712 if (yp_restricted && yp_manycast) { 713 short port; 714 int i; 715 struct sockaddr_in sin; 716 717 i = __yp_ping(restricted_addrs, yp_restricted, 718 ypdb->dom_domain, &port); 719 if (i == -1) { 720 bzero((char *)&ypdb->dom_server_addr, 721 sizeof(struct sockaddr_in)); 722 if (tell_parent(ypdb->dom_domain, 723 &ypdb->dom_server_addr)) 724 syslog(LOG_WARNING, "lost connection to parent"); 725 } else { 726 bzero((char *)&sin, sizeof(struct sockaddr_in)); 727 bcopy((char *)&restricted_addrs[i], 728 (char *)&sin.sin_addr, sizeof(struct in_addr)); 729 sin.sin_family = AF_INET; 730 sin.sin_port = port; 731 if (tell_parent(broad_domain->dom_domain, &sin)) 732 syslog(LOG_WARNING, 733 "lost connection to parent"); 734 } 735 _exit(0); 736 } 737 738 retries = 0; 739 740 { 741 char *ptr; 742 743 ptr = (char *)&ypdb->dom_domain; 744 stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK, 745 xdr_domainname, (char *)&ptr, xdr_bool, (char *)&out, 746 broadcast_result); 747 } 748 749 if (stat != RPC_SUCCESS) { 750 bzero((char *)&ypdb->dom_server_addr, 751 sizeof(struct sockaddr_in)); 752 if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr)) 753 syslog(LOG_WARNING, "lost connection to parent"); 754 } 755 756 _exit(0); 757} 758 759/* 760 * The right way to check if a server is alive. 761 * Attempt to get a client handle pointing to the server and send a 762 * YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE, 763 * we invalidate this binding entry and send out a broadcast to try to 764 * establish a new binding. Note that we treat non-default domains 765 * specially: once bound, we keep tabs on our server, but if it 766 * goes away and fails to respond after one round of broadcasting, we 767 * abandon it until a client specifically references it again. We make 768 * every effort to keep our default domain bound, however, since we 769 * need it to keep the system on its feet. 770 */ 771int 772ping(ypdb) 773struct _dom_binding *ypdb; 774{ 775 bool_t out; 776 struct timeval interval, timeout; 777 enum clnt_stat stat; 778 int rpcsock = RPC_ANYSOCK; 779 CLIENT *client_handle; 780 781 interval.tv_sec = FAIL_THRESHOLD; 782 interval.tv_usec = 0; 783 timeout.tv_sec = FAIL_THRESHOLD; 784 timeout.tv_usec = 0; 785 786 if (ypdb->dom_broadcast_pid) 787 return(1); 788 789 if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr, 790 YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE, 791 RPCSMALLMSGSIZE)) == (CLIENT *)NULL) { 792 /* Can't get a handle: we're dead. */ 793 ypdb->dom_alive = 0; 794 ypdb->dom_vers = -1; 795 broadcast(ypdb); 796 return(1); 797 } 798 799 { 800 char *ptr; 801 802 ptr = (char *)&ypdb->dom_domain; 803 804 if ((stat = clnt_call(client_handle, YPPROC_DOMAIN, 805 xdr_domainname, (char *)&ptr, xdr_bool, (char *)&out, 806 timeout)) != RPC_SUCCESS || out == FALSE) { 807 ypdb->dom_alive = 0; 808 ypdb->dom_vers = -1; 809 clnt_destroy(client_handle); 810 broadcast(ypdb); 811 return(1); 812 } 813 } 814 815 clnt_destroy(client_handle); 816 return(0); 817} 818 819void rpc_received(dom, raddrp, force) 820char *dom; 821struct sockaddr_in *raddrp; 822int force; 823{ 824 struct _dom_binding *ypdb, *prev = NULL; 825 struct iovec iov[2]; 826 struct ypbind_resp ybr; 827 char path[MAXPATHLEN]; 828 int fd; 829 830 /*printf("returned from %s/%d about %s\n", inet_ntoa(raddrp->sin_addr), 831 ntohs(raddrp->sin_port), dom);*/ 832 833 if(dom==NULL) 834 return; 835 836 for(ypdb=ypbindlist; ypdb; ypdb=ypdb->dom_pnext) { 837 if( strcmp(ypdb->dom_domain, dom) == 0) 838 break; 839 prev = ypdb; 840 } 841 842 if (ypdb && force) { 843 if (ypdb->dom_broadcast_pid) { 844 kill(ypdb->dom_broadcast_pid, SIGINT); 845 close(READFD); 846 FD_CLR(READFD, &fdsr); 847 FD_CLR(READFD, &svc_fdset); 848 READFD = WRITEFD = -1; 849 } 850 } 851 852 /* if in secure mode, check originating port number */ 853 if ((ypsecuremode && (ntohs(raddrp->sin_port) >= IPPORT_RESERVED))) { 854 syslog(LOG_WARNING, "Rejected NIS server on [%s/%d] for domain %s.", 855 inet_ntoa(raddrp->sin_addr), ntohs(raddrp->sin_port), 856 dom); 857 if (ypdb != NULL) { 858 ypdb->dom_broadcast_pid = 0; 859 ypdb->dom_alive = 0; 860 } 861 return; 862 } 863 864 if (raddrp->sin_addr.s_addr == (long)0) { 865 switch(ypdb->dom_default) { 866 case 0: 867 if (prev == NULL) 868 ypbindlist = ypdb->dom_pnext; 869 else 870 prev->dom_pnext = ypdb->dom_pnext; 871 sprintf(path, "%s/%s.%ld", BINDINGDIR, 872 ypdb->dom_domain, YPVERS); 873 close(ypdb->dom_lockfd); 874 unlink(path); 875 free(ypdb); 876 domains--; 877 return; 878 case 1: 879 ypdb->dom_broadcast_pid = 0; 880 ypdb->dom_alive = 0; 881 broadcast(ypdb); 882 return; 883 default: 884 break; 885 } 886 } 887 888 if(ypdb==NULL) { 889 if (force == 0) 890 return; 891 ypdb = (struct _dom_binding *)malloc(sizeof *ypdb); 892 if (ypdb == NULL) { 893 syslog(LOG_WARNING, "malloc: %m"); 894 return; 895 } 896 bzero((char *)ypdb, sizeof *ypdb); 897 strncpy(ypdb->dom_domain, dom, sizeof ypdb->dom_domain); 898 ypdb->dom_lockfd = -1; 899 ypdb->dom_default = 0; 900 ypdb->dom_pnext = ypbindlist; 901 ypbindlist = ypdb; 902 } 903 904 /* We've recovered from a crash: inform the world. */ 905 if (ypdb->dom_vers == -1 && ypdb->dom_server_addr.sin_addr.s_addr) 906 syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" OK", 907 inet_ntoa(raddrp->sin_addr), ypdb->dom_domain); 908 909 bcopy((char *)raddrp, (char *)&ypdb->dom_server_addr, 910 sizeof ypdb->dom_server_addr); 911 912 ypdb->dom_vers = YPVERS; 913 ypdb->dom_alive = 1; 914 ypdb->dom_broadcast_pid = 0; 915 916 if(ypdb->dom_lockfd != -1) 917 close(ypdb->dom_lockfd); 918 919 sprintf(path, "%s/%s.%ld", BINDINGDIR, 920 ypdb->dom_domain, ypdb->dom_vers); 921#ifdef O_SHLOCK 922 if( (fd=open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) { 923 (void)mkdir(BINDINGDIR, 0755); 924 if( (fd=open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) 925 return; 926 } 927#else 928 if( (fd=open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) { 929 (void)mkdir(BINDINGDIR, 0755); 930 if( (fd=open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) 931 return; 932 } 933 flock(fd, LOCK_SH); 934#endif 935 936 /* 937 * ok, if BINDINGDIR exists, and we can create the binding file, 938 * then write to it.. 939 */ 940 ypdb->dom_lockfd = fd; 941 942 iov[0].iov_base = (caddr_t)&(udptransp->xp_port); 943 iov[0].iov_len = sizeof udptransp->xp_port; 944 iov[1].iov_base = (caddr_t)&ybr; 945 iov[1].iov_len = sizeof ybr; 946 947 bzero(&ybr, sizeof ybr); 948 ybr.ypbind_status = YPBIND_SUCC_VAL; 949 *(u_long *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = raddrp->sin_addr.s_addr; 950 *(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = raddrp->sin_port; 951 952 if( writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) { 953 syslog(LOG_WARNING, "write: %m"); 954 close(ypdb->dom_lockfd); 955 ypdb->dom_lockfd = -1; 956 return; 957 } 958} 959 960/* 961 * Check address against list of allowed servers. Return 0 if okay, 962 * 1 if not matched. 963 */ 964int 965verify(addr) 966struct in_addr addr; 967{ 968 int i; 969 970 for (i = 0; i < RESTRICTED_SERVERS; i++) 971 if (!bcmp((char *)&addr, (char *)&restricted_addrs[i], 972 sizeof(struct in_addr))) 973 return(0); 974 975 return(1); 976} 977 978/* 979 * Try to set restricted mode. We default to normal mode if we can't 980 * resolve the specified hostnames. 981 */ 982void 983yp_restricted_mode(args) 984char *args; 985{ 986 struct hostent *h; 987 int i = 0; 988 char *s; 989 990 /* Find the restricted domain. */ 991 if ((s = strsep(&args, ",")) == NULL) 992 return; 993 domain_name = s; 994 995 /* Get the addresses of the servers. */ 996 while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) { 997 if ((h = gethostbyname(s)) == NULL) 998 return; 999 bcopy ((char *)h->h_addr_list[0], (char *)&restricted_addrs[i], 1000 sizeof(struct in_addr)); 1001 i++; 1002 } 1003 1004 /* ypset and ypsetme not allowed with restricted mode */ 1005 ypsetmode = YPSET_NO; 1006 1007 yp_restricted = i; 1008 return; 1009} 1010