1 /* 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Rick Macklem at The University of Guelph. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #if defined(LIBC_SCCS) && !defined(lint) 38 static char sccsid[] = "@(#)getnetgrent.c 8.1 (Berkeley) 6/4/93"; 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <stdio.h> 42 #include <strings.h> 43 #include <stdlib.h> 44 #include <unistd.h> 45 46 #ifdef YP 47 /* 48 * Notes: 49 * We want to be able to use NIS netgroups properly while retaining 50 * the ability to use a local /etc/netgroup file. Unfortunately, you 51 * can't really do both at the same time - at least, not efficiently. 52 * NetBSD deals with this problem by creating a netgroup database 53 * using Berkeley DB (just like the password database) that allows 54 * for lookups using netgroup, netgroup.byuser or netgroup.byhost 55 * searches. This is a neat idea, but I don't have time to implement 56 * something like that now. (I think ultimately it would be nice 57 * if we DB-fied the group and netgroup stuff all in one shot, but 58 * for now I'm satisfied just to have something that works well 59 * without requiring massive code changes.) 60 * 61 * Therefore, to still permit the use of the local file and maintain 62 * optimum NIS performance, we allow for the following conditions: 63 * 64 * - If /etc/netgroup does not exist and NIS is turned on, we use 65 * NIS netgroups only. 66 * 67 * - If /etc/netgroup exists but is empty, we use NIS netgroups 68 * only. 69 * 70 * - If /etc/netgroup exists and contains _only_ a '+', we use 71 * NIS netgroups only. 72 * 73 * - If /etc/netgroup exists, contains locally defined netgroups 74 * and a '+', we use a mixture of NIS and the local entries. 75 * This method should return the same NIS data as just using 76 * NIS alone, but it will be slower if the NIS netgroup database 77 * is large (innetgr() in particular will suffer since extra 78 * processing has to be done in order to determine memberships 79 * using just the raw netgroup data). 80 * 81 * - If /etc/netgroup exists and contains only locally defined 82 * netgroup entries, we use just those local entries and ignore 83 * NIS (this is the original, pre-NIS behavior). 84 */ 85 #include <rpc/rpc.h> 86 #include <rpcsvc/yp_prot.h> 87 #include <rpcsvc/ypclnt.h> 88 #include <sys/types.h> 89 #include <sys/stat.h> 90 #include <sys/param.h> 91 #include <sys/errno.h> 92 static char *_netgr_yp_domain; 93 int _use_only_yp; 94 static int _netgr_yp_enabled; 95 static int _yp_innetgr; 96 #endif 97 98 #ifndef _PATH_NETGROUP 99 #define _PATH_NETGROUP "/etc/netgroup" 100 #endif 101 102 /* 103 * Static Variables and functions used by setnetgrent(), getnetgrent() and 104 * endnetgrent(). 105 * There are two linked lists: 106 * - linelist is just used by setnetgrent() to parse the net group file via. 107 * parse_netgrp() 108 * - netgrp is the list of entries for the current netgroup 109 */ 110 struct linelist { 111 struct linelist *l_next; /* Chain ptr. */ 112 int l_parsed; /* Flag for cycles */ 113 char *l_groupname; /* Name of netgroup */ 114 char *l_line; /* Netgroup entrie(s) to be parsed */ 115 }; 116 117 struct netgrp { 118 struct netgrp *ng_next; /* Chain ptr */ 119 char *ng_str[3]; /* Field pointers, see below */ 120 }; 121 #define NG_HOST 0 /* Host name */ 122 #define NG_USER 1 /* User name */ 123 #define NG_DOM 2 /* and Domain name */ 124 125 static struct linelist *linehead = (struct linelist *)0; 126 static struct netgrp *nextgrp = (struct netgrp *)0; 127 static struct { 128 struct netgrp *gr; 129 char *grname; 130 } grouphead = { 131 (struct netgrp *)0, 132 (char *)0, 133 }; 134 static FILE *netf = (FILE *)0; 135 static int parse_netgrp(); 136 static struct linelist *read_for_group(); 137 void setnetgrent(), endnetgrent(); 138 int getnetgrent(), innetgr(); 139 140 #define LINSIZ 1024 /* Length of netgroup file line */ 141 142 /* 143 * setnetgrent() 144 * Parse the netgroup file looking for the netgroup and build the list 145 * of netgrp structures. Let parse_netgrp() and read_for_group() do 146 * most of the work. 147 */ 148 void 149 setnetgrent(group) 150 char *group; 151 { 152 #ifdef YP 153 struct stat _yp_statp; 154 char _yp_plus; 155 #endif 156 157 /* Sanity check */ 158 159 if (group == NULL || !strlen(group)) 160 return; 161 162 if (grouphead.gr == (struct netgrp *)0 || 163 strcmp(group, grouphead.grname)) { 164 endnetgrent(); 165 #ifdef YP 166 /* Presumed guilty until proven innocent. */ 167 _use_only_yp = 0; 168 /* 169 * IF /etc/netgroup doesn't exist or is empty, 170 * use NIS exclusively. 171 */ 172 if (((stat(_PATH_NETGROUP, &_yp_statp) < 0) && 173 errno == ENOENT) || _yp_statp.st_size == 0) 174 _use_only_yp = _netgr_yp_enabled = 1; 175 if ((netf = fopen(_PATH_NETGROUP,"r")) != NULL ||_use_only_yp){ 176 /* 177 * Icky: grab the first character of the netgroup file 178 * and turn on NIS if it's a '+'. rewind the stream 179 * afterwards so we don't goof up read_for_group() later. 180 */ 181 if (netf) { 182 fscanf(netf, "%c", &_yp_plus); 183 rewind(netf); 184 if (_yp_plus == '+') 185 _use_only_yp = _netgr_yp_enabled = 1; 186 } 187 /* 188 * If we were called specifically for an innetgr() 189 * lookup and we're in NIS-only mode, short-circuit 190 * parse_netgroup() and cut directly to the chase. 191 */ 192 if (_use_only_yp && _yp_innetgr) { 193 /* dohw! */ 194 fclose(netf); 195 return; 196 } 197 #else 198 if (netf = fopen(_PATH_NETGROUP, "r")) { 199 #endif 200 if (parse_netgrp(group)) 201 endnetgrent(); 202 else { 203 grouphead.grname = (char *) 204 malloc(strlen(group) + 1); 205 strcpy(grouphead.grname, group); 206 } 207 if (netf) 208 fclose(netf); 209 } 210 } 211 nextgrp = grouphead.gr; 212 } 213 214 /* 215 * Get the next netgroup off the list. 216 */ 217 int 218 getnetgrent(hostp, userp, domp) 219 char **hostp, **userp, **domp; 220 { 221 #ifdef YP 222 _yp_innetgr = 0; 223 #endif 224 225 if (nextgrp) { 226 *hostp = nextgrp->ng_str[NG_HOST]; 227 *userp = nextgrp->ng_str[NG_USER]; 228 *domp = nextgrp->ng_str[NG_DOM]; 229 nextgrp = nextgrp->ng_next; 230 return (1); 231 } 232 return (0); 233 } 234 235 /* 236 * endnetgrent() - cleanup 237 */ 238 void 239 endnetgrent() 240 { 241 register struct linelist *lp, *olp; 242 register struct netgrp *gp, *ogp; 243 244 lp = linehead; 245 while (lp) { 246 olp = lp; 247 lp = lp->l_next; 248 free(olp->l_groupname); 249 free(olp->l_line); 250 free((char *)olp); 251 } 252 linehead = (struct linelist *)0; 253 if (grouphead.grname) { 254 free(grouphead.grname); 255 grouphead.grname = (char *)0; 256 } 257 gp = grouphead.gr; 258 while (gp) { 259 ogp = gp; 260 gp = gp->ng_next; 261 if (ogp->ng_str[NG_HOST]) 262 free(ogp->ng_str[NG_HOST]); 263 if (ogp->ng_str[NG_USER]) 264 free(ogp->ng_str[NG_USER]); 265 if (ogp->ng_str[NG_DOM]) 266 free(ogp->ng_str[NG_DOM]); 267 free((char *)ogp); 268 } 269 grouphead.gr = (struct netgrp *)0; 270 #ifdef YP 271 _netgr_yp_enabled = 0; 272 #endif 273 } 274 275 #ifdef YP 276 static int _listmatch(list, group, len) 277 char *list, *group; 278 int len; 279 { 280 char *ptr = list; 281 282 while (ptr != (char *)(list + len)) { 283 if (!strncmp(group, ptr, strlen(group))) 284 return(1); 285 ptr++; 286 } 287 return(0); 288 } 289 290 static int _buildkey(key, str, dom, rotation) 291 char *key, *str, *dom; 292 int *rotation; 293 { 294 (*rotation)++; 295 if (*rotation > 4) 296 return(0); 297 switch(*rotation) { 298 case(1): sprintf((char *)key, "%s.%s", str, dom ? dom : "*"); 299 break; 300 case(2): sprintf((char *)key, "%s.*", str); 301 break; 302 case(3): sprintf((char *)key, "*.%s", dom ? dom : "*"); 303 break; 304 case(4): sprintf((char *)key, "*.*"); 305 break; 306 } 307 return(1); 308 } 309 #endif 310 311 /* 312 * Search for a match in a netgroup. 313 */ 314 int 315 innetgr(group, host, user, dom) 316 char *group, *host, *user, *dom; 317 { 318 char *hst, *usr, *dm; 319 #ifdef YP 320 char *result; 321 int resultlen; 322 #endif 323 /* Sanity check */ 324 325 if (group == NULL || !strlen(group)) 326 return (0); 327 328 #ifdef YP 329 _yp_innetgr = 1; 330 #endif 331 setnetgrent(group); 332 #ifdef YP 333 /* 334 * If we're in NIS-only mode, do the search using 335 * NIS 'reverse netgroup' lookups. 336 */ 337 if (_use_only_yp) { 338 char _key[MAXHOSTNAMELEN]; 339 int rot = 0; 340 341 if(yp_get_default_domain(&_netgr_yp_domain)) 342 return(0); 343 while(_buildkey(&_key, user ? user : host, dom, &rot)) { 344 if (yp_match(_netgr_yp_domain, user? "netgroup.byuser": 345 "netgroup.byhost", _key, strlen(_key), &result, 346 &resultlen)) 347 free(result); 348 else { 349 if (_listmatch(result, group, resultlen)) { 350 free(result); 351 return(1); 352 } 353 } 354 } 355 free(result); 356 #ifdef CHARITABLE 357 } 358 /* 359 * Couldn't match using NIS-exclusive mode -- try 360 * standard mode. 361 */ 362 _yp_innetgr = 0; 363 setnetgrent(group); 364 #else 365 return(0); 366 } 367 #endif /* CHARITABLE */ 368 #endif /* YP */ 369 while (getnetgrent(&hst, &usr, &dm)) 370 if ((host == NULL || hst == NULL || !strcmp(host, hst)) && 371 (user == NULL || usr == NULL || !strcmp(user, usr)) && 372 ( dom == NULL || dm == NULL || !strcmp(dom, dm))) { 373 endnetgrent(); 374 return (1); 375 } 376 endnetgrent(); 377 return (0); 378 } 379 380 /* 381 * Parse the netgroup file setting up the linked lists. 382 */ 383 static int 384 parse_netgrp(group) 385 char *group; 386 { 387 register char *spos, *epos; 388 register int len, strpos; 389 #ifdef DEBUG 390 register int fields; 391 #endif 392 char *pos, *gpos; 393 struct netgrp *grp; 394 struct linelist *lp = linehead; 395 396 /* 397 * First, see if the line has already been read in. 398 */ 399 while (lp) { 400 if (!strcmp(group, lp->l_groupname)) 401 break; 402 lp = lp->l_next; 403 } 404 if (lp == (struct linelist *)0 && 405 (lp = read_for_group(group)) == (struct linelist *)0) 406 return (1); 407 if (lp->l_parsed) { 408 #ifdef DEBUG 409 /* 410 * This error message is largely superflous since the 411 * code handles the error condition sucessfully, and 412 * spewing it out from inside libc can actually hose 413 * certain programs. 414 */ 415 fprintf(stderr, "Cycle in netgroup %s\n", lp->l_groupname); 416 #endif 417 return (1); 418 } else 419 lp->l_parsed = 1; 420 pos = lp->l_line; 421 /* Watch for null pointer dereferences, dammit! */ 422 while (pos != NULL && *pos != '\0') { 423 if (*pos == '(') { 424 grp = (struct netgrp *)malloc(sizeof (struct netgrp)); 425 bzero((char *)grp, sizeof (struct netgrp)); 426 grp->ng_next = grouphead.gr; 427 grouphead.gr = grp; 428 pos++; 429 gpos = strsep(&pos, ")"); 430 #ifdef DEBUG 431 fields = 0; 432 #endif 433 for (strpos = 0; strpos < 3; strpos++) { 434 if ((spos = strsep(&gpos, ","))) { 435 #ifdef DEBUG 436 fields++; 437 #endif 438 while (*spos == ' ' || *spos == '\t') 439 spos++; 440 if ((epos = strpbrk(spos, " \t"))) { 441 *epos = '\0'; 442 len = epos - spos; 443 } else 444 len = strlen(spos); 445 if (len > 0) { 446 grp->ng_str[strpos] = (char *) 447 malloc(len + 1); 448 bcopy(spos, grp->ng_str[strpos], 449 len + 1); 450 } 451 } else { 452 /* 453 * All other systems I've tested 454 * return NULL for empty netgroup 455 * fields. It's up to user programs 456 * to handle the NULLs appropriately. 457 */ 458 grp->ng_str[strpos] = NULL; 459 } 460 } 461 #ifdef DEBUG 462 /* 463 * Note: on other platforms, malformed netgroup 464 * entries are not normally flagged. While we 465 * can catch bad entries and report them, we should 466 * stay silent by default for compatibility's sake. 467 */ 468 if (fields < 3) 469 fprintf(stderr, "Bad entry (%s%s%s%s%s) in netgroup \"%s\"\n", 470 grp->ng_str[NG_HOST] == NULL ? "" : grp->ng_str[NG_HOST], 471 grp->ng_str[NG_USER] == NULL ? "" : ",", 472 grp->ng_str[NG_USER] == NULL ? "" : grp->ng_str[NG_USER], 473 grp->ng_str[NG_DOM] == NULL ? "" : ",", 474 grp->ng_str[NG_DOM] == NULL ? "" : grp->ng_str[NG_DOM], 475 lp->l_groupname); 476 #endif 477 } else { 478 spos = strsep(&pos, ", \t"); 479 if (parse_netgrp(spos)) 480 continue; 481 } 482 /* Watch for null pointer dereferences, dammit! */ 483 if (pos != NULL) 484 while (*pos == ' ' || *pos == ',' || *pos == '\t') 485 pos++; 486 } 487 return (0); 488 } 489 490 /* 491 * Read the netgroup file and save lines until the line for the netgroup 492 * is found. Return 1 if eof is encountered. 493 */ 494 static struct linelist * 495 read_for_group(group) 496 char *group; 497 { 498 register char *pos, *spos, *linep, *olinep; 499 register int len, olen; 500 int cont; 501 struct linelist *lp; 502 char line[LINSIZ + 1]; 503 #ifdef YP 504 char *result; 505 int resultlen; 506 507 while (_netgr_yp_enabled || fgets(line, LINSIZ, netf) != NULL) { 508 if (_netgr_yp_enabled) { 509 if(!_netgr_yp_domain) 510 if(yp_get_default_domain(&_netgr_yp_domain)) 511 continue; 512 if (yp_match(_netgr_yp_domain, "netgroup", group, 513 strlen(group), &result, &resultlen)) { 514 free(result); 515 if (_use_only_yp) 516 return ((struct linelist *)0); 517 else { 518 _netgr_yp_enabled = 0; 519 continue; 520 } 521 } 522 sprintf(line, "%s %s", group, result); 523 free(result); 524 } 525 #else 526 while (fgets(line, LINSIZ, netf) != NULL) { 527 #endif 528 pos = (char *)&line; 529 #ifdef YP 530 if (*pos == '+') { 531 _netgr_yp_enabled = 1; 532 continue; 533 } 534 #endif 535 if (*pos == '#') 536 continue; 537 while (*pos == ' ' || *pos == '\t') 538 pos++; 539 spos = pos; 540 while (*pos != ' ' && *pos != '\t' && *pos != '\n' && 541 *pos != '\0') 542 pos++; 543 len = pos - spos; 544 while (*pos == ' ' || *pos == '\t') 545 pos++; 546 if (*pos != '\n' && *pos != '\0') { 547 lp = (struct linelist *)malloc(sizeof (*lp)); 548 lp->l_parsed = 0; 549 lp->l_groupname = (char *)malloc(len + 1); 550 bcopy(spos, lp->l_groupname, len); 551 *(lp->l_groupname + len) = '\0'; 552 len = strlen(pos); 553 olen = 0; 554 555 /* 556 * Loop around handling line continuations. 557 */ 558 do { 559 if (*(pos + len - 1) == '\n') 560 len--; 561 if (*(pos + len - 1) == '\\') { 562 len--; 563 cont = 1; 564 } else 565 cont = 0; 566 if (len > 0) { 567 linep = (char *)malloc(olen + len + 1); 568 if (olen > 0) { 569 bcopy(olinep, linep, olen); 570 free(olinep); 571 } 572 bcopy(pos, linep + olen, len); 573 olen += len; 574 *(linep + olen) = '\0'; 575 olinep = linep; 576 } 577 if (cont) { 578 if (fgets(line, LINSIZ, netf)) { 579 pos = line; 580 len = strlen(pos); 581 } else 582 cont = 0; 583 } 584 } while (cont); 585 lp->l_line = linep; 586 lp->l_next = linehead; 587 linehead = lp; 588 589 /* 590 * If this is the one we wanted, we are done. 591 */ 592 if (!strcmp(lp->l_groupname, group)) 593 return (lp); 594 } 595 } 596 #ifdef YP 597 /* 598 * Yucky. The recursive nature of this whole mess might require 599 * us to make more than one pass through the netgroup file. 600 * This might be best left outside the #ifdef YP, but YP is 601 * defined by default anyway, so I'll leave it like this 602 * until I know better. 603 */ 604 rewind(netf); 605 #endif 606 return ((struct linelist *)0); 607 } 608