getgrent.c revision 23530
1189142Sdas/* 2189142Sdas * Copyright (c) 1989, 1993 3189142Sdas * The Regents of the University of California. All rights reserved. 4189142Sdas * 5189142Sdas * Redistribution and use in source and binary forms, with or without 6189142Sdas * modification, are permitted provided that the following conditions 7189142Sdas * are met: 8189142Sdas * 1. Redistributions of source code must retain the above copyright 9189142Sdas * notice, this list of conditions and the following disclaimer. 10189142Sdas * 2. Redistributions in binary form must reproduce the above copyright 11189142Sdas * notice, this list of conditions and the following disclaimer in the 12189142Sdas * documentation and/or other materials provided with the distribution. 13189142Sdas * 3. All advertising materials mentioning features or use of this software 14189142Sdas * must display the following acknowledgement: 15189142Sdas * This product includes software developed by the University of 16189142Sdas * California, Berkeley and its contributors. 17189142Sdas * 4. Neither the name of the University nor the names of its contributors 18189142Sdas * may be used to endorse or promote products derived from this software 19189142Sdas * without specific prior written permission. 20189142Sdas * 21189142Sdas * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22189142Sdas * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23189142Sdas * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24189142Sdas * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25189142Sdas * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26189142Sdas * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27189142Sdas * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28189142Sdas * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29189142Sdas * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30189142Sdas * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31189142Sdas * SUCH DAMAGE. 32189142Sdas */ 33189142Sdas 34189142Sdas#if defined(LIBC_SCCS) && !defined(lint) 35189142Sdasstatic char sccsid[] = "@(#)getgrent.c 8.2 (Berkeley) 3/21/94"; 36189142Sdas#endif /* LIBC_SCCS and not lint */ 37189142Sdas 38189142Sdas#include <sys/types.h> 39189142Sdas#include <stdio.h> 40189142Sdas#include <stdlib.h> 41189142Sdas#include <string.h> 42189142Sdas#include <grp.h> 43189142Sdas 44189142Sdasstatic FILE *_gr_fp; 45189142Sdasstatic struct group _gr_group; 46189142Sdasstatic int _gr_stayopen; 47189142Sdasstatic int grscan(), start_gr(); 48189142Sdas#ifdef YP 49189142Sdas#include <rpc/rpc.h> 50189142Sdas#include <rpcsvc/yp_prot.h> 51189142Sdas#include <rpcsvc/ypclnt.h> 52189142Sdasstatic int _gr_stepping_yp; 53189142Sdasstatic int _gr_yp_enabled; 54189142Sdasstatic int _getypgroup(struct group *, const char *, char *); 55189142Sdasstatic int _nextypgroup(struct group *); 56189142Sdas#endif 57189142Sdas 58189142Sdas/* initial size for malloc and increase steps for realloc */ 59189142Sdas#define MAXGRP 64 60189142Sdas#define MAXLINELENGTH 256 61189142Sdas 62189142Sdasstatic char **members; /* list of group members */ 63189142Sdasstatic int maxgrp; /* current length of **mebers */ 64189142Sdasstatic char *line; /* temp buffer for group line */ 65189142Sdasstatic int maxlinelength; /* current length of *line */ 66189142Sdas 67189142Sdas/* 68189142Sdas * Lines longer than MAXLINELENGTHLIMIT will be count as an error. 69189142Sdas * <= 0 disable check for maximum line length 70189142Sdas * 256K is enough for 64,000 uids 71189142Sdas */ 72189142Sdas#define MAXLINELENGTHLIMIT (256 * 1024) 73189142Sdas#define GROUP_IGNORE_COMMENTS 1 /* allow comments in /etc/group */ 74189142Sdas 75189142Sdasstruct group * 76189142Sdasgetgrent() 77189142Sdas{ 78189142Sdas if (!_gr_fp && !start_gr()) { 79189142Sdas return NULL; 80189142Sdas } 81189142Sdas 82189142Sdas#ifdef YP 83197753Sdas if (_gr_stepping_yp) { 84189142Sdas if (_nextypgroup(&_gr_group)) 85189142Sdas return(&_gr_group); 86189142Sdas } 87189142Sdastryagain: 88189142Sdas#endif 89189142Sdas 90189142Sdas if (!grscan(0, 0, NULL)) 91189142Sdas return(NULL); 92189142Sdas#ifdef YP 93189142Sdas if(_gr_group.gr_name[0] == '+' && _gr_group.gr_name[1]) { 94189142Sdas _getypgroup(&_gr_group, &_gr_group.gr_name[1], 95189142Sdas "group.byname"); 96189142Sdas } else if(_gr_group.gr_name[0] == '+') { 97189142Sdas if (!_nextypgroup(&_gr_group)) 98189142Sdas goto tryagain; 99189142Sdas else 100189142Sdas return(&_gr_group); 101189142Sdas } 102189142Sdas#endif 103190773Sdas return(&_gr_group); 104189142Sdas} 105189142Sdas 106197753Sdasstruct group * 107189142Sdasgetgrnam(name) 108189142Sdas const char *name; 109189142Sdas{ 110189142Sdas int rval; 111189142Sdas 112189142Sdas if (!start_gr()) 113189142Sdas return(NULL); 114189142Sdas#ifdef YP 115189142Sdas tryagain: 116189142Sdas#endif 117189142Sdas rval = grscan(1, 0, name); 118189142Sdas#ifdef YP 119189142Sdas if(rval == -1 && (_gr_yp_enabled < 0 || (_gr_yp_enabled && 120189142Sdas _gr_group.gr_name[0] == '+'))) { 121189142Sdas if (!(rval = _getypgroup(&_gr_group, name, "group.byname"))) 122189142Sdas goto tryagain; 123189142Sdas } 124189142Sdas#endif 125189142Sdas if (!_gr_stayopen) 126189142Sdas endgrent(); 127189142Sdas return(rval ? &_gr_group : NULL); 128189142Sdas} 129189142Sdas 130189142Sdasstruct group * 131189142Sdas#ifdef __STDC__ 132189142Sdasgetgrgid(gid_t gid) 133189142Sdas#else 134189142Sdasgetgrgid(gid) 135189142Sdas gid_t gid; 136189142Sdas#endif 137189142Sdas{ 138189142Sdas int rval; 139189142Sdas 140189142Sdas if (!start_gr()) 141189142Sdas return(NULL); 142189142Sdas#ifdef YP 143190773Sdas tryagain: 144189142Sdas#endif 145189142Sdas rval = grscan(1, gid, NULL); 146189142Sdas#ifdef YP 147189142Sdas if(rval == -1 && _gr_yp_enabled) { 148189142Sdas char buf[16]; 149189142Sdas snprintf(buf, sizeof buf, "%d", (unsigned)gid); 150189142Sdas if (!(rval = _getypgroup(&_gr_group, buf, "group.bygid"))) 151189142Sdas goto tryagain; 152189142Sdas } 153189142Sdas#endif 154189142Sdas if (!_gr_stayopen) 155189142Sdas endgrent(); 156189142Sdas return(rval ? &_gr_group : NULL); 157189142Sdas} 158189142Sdas 159189142Sdasstatic int 160189142Sdasstart_gr() 161189142Sdas{ 162189142Sdas if (_gr_fp) { 163189142Sdas rewind(_gr_fp); 164189142Sdas return(1); 165189142Sdas } 166189142Sdas _gr_fp = fopen(_PATH_GROUP, "r"); 167189142Sdas if(!_gr_fp) return 0; 168197753Sdas#ifdef YP 169197753Sdas /* 170197753Sdas * This is a disgusting hack, used to determine when YP is enabled. 171197753Sdas * This would be easier if we had a group database to go along with 172197753Sdas * the password database. 173197753Sdas */ 174197753Sdas { 175197753Sdas char *line; 176197753Sdas size_t linelen; 177197753Sdas _gr_yp_enabled = 0; 178197753Sdas while((line = fgetln(_gr_fp, &linelen)) != NULL) { 179197753Sdas if(line[0] == '+') { 180197753Sdas if(line[1] && line[1] != ':' && !_gr_yp_enabled) { 181197753Sdas _gr_yp_enabled = 1; 182197753Sdas } else { 183197753Sdas _gr_yp_enabled = -1; 184197753Sdas break; 185197753Sdas } 186189142Sdas } 187189142Sdas } 188 rewind(_gr_fp); 189 } 190#endif 191 192 if (maxlinelength == 0) { 193 if ((line = (char *)malloc(sizeof(char) * 194 MAXLINELENGTH)) == NULL) 195 return(0); 196 maxlinelength += MAXLINELENGTH; 197 } 198 199 if (maxgrp == 0) { 200 if ((members = (char **)malloc(sizeof(char **) * 201 MAXGRP)) == NULL) 202 return(0); 203 maxgrp += MAXGRP; 204 } 205 206 return 1; 207} 208 209int 210setgrent() 211{ 212 return(setgroupent(0)); 213} 214 215int 216setgroupent(stayopen) 217 int stayopen; 218{ 219 if (!start_gr()) 220 return(0); 221 _gr_stayopen = stayopen; 222#ifdef YP 223 _gr_stepping_yp = 0; 224#endif 225 return(1); 226} 227 228void 229endgrent() 230{ 231#ifdef YP 232 _gr_stepping_yp = 0; 233#endif 234 if (_gr_fp) { 235 (void)fclose(_gr_fp); 236 _gr_fp = NULL; 237 } 238} 239 240static int 241grscan(search, gid, name) 242 register int search, gid; 243 register char *name; 244{ 245 register char *cp, **m; 246 char *bp; 247 248 249#ifdef YP 250 int _ypfound; 251#endif 252 for (;;) { 253#ifdef YP 254 _ypfound = 0; 255#endif 256 if (fgets(line, maxlinelength, _gr_fp) == NULL) 257 return(0); 258 259 if (!index(line, '\n')) { 260 do { 261 if (feof(_gr_fp)) 262 return(0); 263 264 /* don't allocate infinite memory */ 265 if (MAXLINELENGTHLIMIT > 0 && 266 maxlinelength >= MAXLINELENGTHLIMIT) 267 return(0); 268 269 if ((line = (char *)realloc(line, 270 sizeof(char) * 271 (maxlinelength + MAXLINELENGTH))) == NULL) 272 return(0); 273 274 if (fgets(line + maxlinelength - 1, 275 MAXLINELENGTH + 1, _gr_fp) == NULL) 276 return(0); 277 278 maxlinelength += MAXLINELENGTH; 279 } while (!index(line + maxlinelength - 280 MAXLINELENGTH - 1, '\n')); 281 } 282 283#ifdef GROUP_IGNORE_COMMENTS 284 /* 285 * Ignore comments: ^[ \t]*# 286 */ 287 for (cp = line; *cp != '\0'; cp++) 288 if (*cp != ' ' && *cp != '\t') 289 break; 290 if (*cp == '#' || *cp == '\0') 291 continue; 292#endif 293 294 bp = line; 295 296 if ((_gr_group.gr_name = strsep(&bp, ":\n")) == NULL) 297 break; 298#ifdef YP 299 /* 300 * XXX We need to be careful to avoid proceeding 301 * past this point under certain circumstances or 302 * we risk dereferencing null pointers down below. 303 */ 304 if (_gr_group.gr_name[0] == '+') { 305 if (strlen(_gr_group.gr_name) == 1) { 306 switch(search) { 307 case 0: 308 return(1); 309 case 1: 310 return(-1); 311 default: 312 return(0); 313 } 314 } else { 315 cp = &_gr_group.gr_name[1]; 316 if (search && name != NULL) 317 if (strcmp(cp, name)) 318 continue; 319 if (!_getypgroup(&_gr_group, cp, 320 "group.byname")) 321 continue; 322 if (search && name == NULL) 323 if (gid != _gr_group.gr_gid) 324 continue; 325 /* We're going to override -- tell the world. */ 326 _ypfound++; 327 } 328 } 329#else 330 if (_gr_group.gr_name[0] == '+') 331 continue; 332#endif /* YP */ 333 if (search && name) { 334 if(strcmp(_gr_group.gr_name, name)) { 335 continue; 336 } 337 } 338#ifdef YP 339 if ((cp = strsep(&bp, ":\n")) == NULL) 340 if (_ypfound) 341 return(1); 342 else 343 break; 344 if (strlen(cp) || !_ypfound) 345 _gr_group.gr_passwd = cp; 346#else 347 if ((_gr_group.gr_passwd = strsep(&bp, ":\n")) == NULL) 348 break; 349#endif 350 if (!(cp = strsep(&bp, ":\n"))) 351#ifdef YP 352 if (_ypfound) 353 return(1); 354 else 355#endif 356 continue; 357#ifdef YP 358 /* 359 * Hurm. Should we be doing this? We allow UIDs to 360 * be overridden -- what about GIDs? 361 */ 362 if (!_ypfound) 363#endif 364 _gr_group.gr_gid = atoi(cp); 365 if (search && name == NULL && _gr_group.gr_gid != gid) 366 continue; 367 cp = NULL; 368 if (bp == NULL) /* !!! Must check for this! */ 369 break; 370#ifdef YP 371 if ((cp = strsep(&bp, ":\n")) == NULL) 372 break; 373 374 if (!strlen(cp) && _ypfound) 375 return(1); 376 else 377 members[0] = NULL; 378 bp = cp; 379 cp = NULL; 380#endif 381 for (m = members; ; bp++) { 382 if (m == (members + maxgrp - 1)) { 383 if ((members = (char **) 384 realloc(members, 385 sizeof(char **) * 386 (maxgrp + MAXGRP))) == NULL) 387 return(0); 388 m = members + maxgrp - 1; 389 maxgrp += MAXGRP; 390 } 391 if (*bp == ',') { 392 if (cp) { 393 *bp = '\0'; 394 *m++ = cp; 395 cp = NULL; 396 } 397 } else if (*bp == '\0' || *bp == '\n' || *bp == ' ') { 398 if (cp) { 399 *bp = '\0'; 400 *m++ = cp; 401 } 402 break; 403 } else if (cp == NULL) 404 cp = bp; 405 406 } 407 _gr_group.gr_mem = members; 408 *m = NULL; 409 return(1); 410 } 411 /* NOTREACHED */ 412 return (0); 413} 414 415#ifdef YP 416 417static int 418_gr_breakout_yp(struct group *gr, char *result) 419{ 420 char *s, *cp; 421 char **m; 422 423 /* 424 * XXX If 's' ends up being a NULL pointer, punt on this group. 425 * It means the NIS group entry is badly formatted and should 426 * be skipped. 427 */ 428 if ((s = strsep(&result, ":")) == NULL) return 0; /* name */ 429 gr->gr_name = s; 430 431 if ((s = strsep(&result, ":")) == NULL) return 0; /* password */ 432 gr->gr_passwd = s; 433 434 if ((s = strsep(&result, ":")) == NULL) return 0; /* gid */ 435 gr->gr_gid = atoi(s); 436 437 if ((s = result) == NULL) return 0; 438 cp = 0; 439 440 for (m = members; ; s++) { 441 if (m == members + maxgrp - 1) { 442 if ((members = (char **)realloc(members, 443 sizeof(char **) * (maxgrp + MAXGRP))) == NULL) 444 return(0); 445 m = members + maxgrp - 1; 446 maxgrp += MAXGRP; 447 } 448 if (*s == ',') { 449 if (cp) { 450 *s = '\0'; 451 *m++ = cp; 452 cp = NULL; 453 } 454 } else if (*s == '\0' || *s == '\n' || *s == ' ') { 455 if (cp) { 456 *s = '\0'; 457 *m++ = cp; 458 } 459 break; 460 } else if (cp == NULL) { 461 cp = s; 462 } 463 } 464 _gr_group.gr_mem = members; 465 *m = NULL; 466 467 return 1; 468} 469 470static char *_gr_yp_domain; 471 472static int 473_getypgroup(struct group *gr, const char *name, char *map) 474{ 475 char *result, *s; 476 static char resultbuf[YPMAXRECORD + 2]; 477 int resultlen; 478 479 if(!_gr_yp_domain) { 480 if(yp_get_default_domain(&_gr_yp_domain)) 481 return 0; 482 } 483 484 if(yp_match(_gr_yp_domain, map, name, strlen(name), 485 &result, &resultlen)) 486 return 0; 487 488 s = strchr(result, '\n'); 489 if(s) *s = '\0'; 490 491 if(resultlen >= sizeof resultbuf) return 0; 492 strncpy(resultbuf, result, resultlen); 493 resultbuf[resultlen] = '\0'; 494 free(result); 495 return(_gr_breakout_yp(gr, resultbuf)); 496 497} 498 499 500static int 501_nextypgroup(struct group *gr) 502{ 503 static char *key; 504 static int keylen; 505 char *lastkey, *result; 506 static char resultbuf[YPMAXRECORD + 2]; 507 int resultlen; 508 int rv; 509 510 if(!_gr_yp_domain) { 511 if(yp_get_default_domain(&_gr_yp_domain)) 512 return 0; 513 } 514 515 if(!_gr_stepping_yp) { 516 if(key) free(key); 517 rv = yp_first(_gr_yp_domain, "group.byname", 518 &key, &keylen, &result, &resultlen); 519 if(rv) { 520 return 0; 521 } 522 _gr_stepping_yp = 1; 523 goto unpack; 524 } else { 525tryagain: 526 lastkey = key; 527 rv = yp_next(_gr_yp_domain, "group.byname", key, keylen, 528 &key, &keylen, &result, &resultlen); 529 free(lastkey); 530unpack: 531 if(rv) { 532 _gr_stepping_yp = 0; 533 return 0; 534 } 535 536 if(resultlen > sizeof(resultbuf)) { 537 free(result); 538 goto tryagain; 539 } 540 541 strncpy(resultbuf, result, resultlen); 542 resultbuf[resultlen] = '\0'; 543 free(result); 544 if((result = strchr(resultbuf, '\n')) != NULL) 545 *result = '\0'; 546 if (_gr_breakout_yp(gr, resultbuf)) 547 return(1); 548 else 549 goto tryagain; 550 } 551} 552 553#endif /* YP */ 554