1 /* $NetBSD: getgrent.c,v 1.34.2.1 1999/04/27 14:10:58 perry Exp $ */ 2 /* 3 * Copyright (c) 1989, 1993 4 * The Regents of the University of California. All rights reserved. 5 * Portions Copyright (c) 1994, Jason Downs. All Rights Reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)getgrent.c 8.2 (Berkeley) 3/21/94 36 * $FreeBSD: src/lib/libc/gen/getgrent.c,v 1.17.6.1 2001/03/05 08:56:02 obrien Exp $ 37 * $DragonFly: src/lib/libc/gen/getgrent.c,v 1.3 2004/06/06 15:05:55 hmp Exp $ 38 */ 39 40 #include <errno.h> 41 #include <limits.h> 42 #include <sys/types.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <grp.h> 47 #include <syslog.h> 48 49 static FILE *_gr_fp; 50 static struct group _gr_group; 51 static int _gr_stayopen; 52 static int grscan(), start_gr(); 53 #ifdef YP 54 #include <rpc/rpc.h> 55 #include <rpcsvc/yp_prot.h> 56 #include <rpcsvc/ypclnt.h> 57 static int _gr_stepping_yp; 58 static int _gr_yp_enabled; 59 static int _getypgroup(struct group *, const char *, char *); 60 static int _nextypgroup(struct group *); 61 #endif 62 63 /* initial size for malloc and increase steps for realloc */ 64 #define MAXGRP 64 65 #define MAXLINELENGTH 256 66 67 static char **members; /* list of group members */ 68 static int maxgrp; /* current length of **mebers */ 69 static char *line; /* temp buffer for group line */ 70 static int maxlinelength; /* current length of *line */ 71 72 /* 73 * Lines longer than MAXLINELENGTHLIMIT will be counted as an error. 74 * <= 0 disable check for maximum line length 75 * 256K is enough for 64,000 uids 76 */ 77 #define MAXLINELENGTHLIMIT (256 * 1024) 78 #define GROUP_IGNORE_COMMENTS 1 /* allow comments in /etc/group */ 79 80 struct group * 81 getgrent() 82 { 83 if (!_gr_fp && !start_gr()) { 84 return NULL; 85 } 86 87 #ifdef YP 88 if (_gr_stepping_yp) { 89 if (_nextypgroup(&_gr_group)) 90 return(&_gr_group); 91 } 92 tryagain: 93 #endif 94 95 if (!grscan(0, 0, NULL)) 96 return(NULL); 97 #ifdef YP 98 if(_gr_group.gr_name[0] == '+' && _gr_group.gr_name[1]) { 99 _getypgroup(&_gr_group, &_gr_group.gr_name[1], 100 "group.byname"); 101 } else if(_gr_group.gr_name[0] == '+') { 102 if (!_nextypgroup(&_gr_group)) 103 goto tryagain; 104 else 105 return(&_gr_group); 106 } 107 #endif 108 return(&_gr_group); 109 } 110 111 struct group * 112 getgrnam(name) 113 const char *name; 114 { 115 int rval; 116 117 if (!start_gr()) 118 return(NULL); 119 #ifdef YP 120 tryagain: 121 #endif 122 rval = grscan(1, 0, name); 123 #ifdef YP 124 if(rval == -1 && (_gr_yp_enabled < 0 || (_gr_yp_enabled && 125 _gr_group.gr_name[0] == '+'))) { 126 if (!(rval = _getypgroup(&_gr_group, name, "group.byname"))) 127 goto tryagain; 128 } 129 #endif 130 if (!_gr_stayopen) 131 endgrent(); 132 return (rval) ? &_gr_group : NULL; 133 } 134 135 struct group * 136 getgrgid(gid) 137 gid_t gid; 138 { 139 int rval; 140 141 if (!start_gr()) 142 return(NULL); 143 #ifdef YP 144 tryagain: 145 #endif 146 rval = grscan(1, gid, NULL); 147 #ifdef YP 148 if(rval == -1 && _gr_yp_enabled) { 149 char buf[16]; 150 snprintf(buf, sizeof buf, "%d", (unsigned)gid); 151 if (!(rval = _getypgroup(&_gr_group, buf, "group.bygid"))) 152 goto tryagain; 153 } 154 #endif 155 if (!_gr_stayopen) 156 endgrent(); 157 return (rval) ? &_gr_group : NULL; 158 } 159 160 static int 161 start_gr() 162 { 163 if (_gr_fp) { 164 rewind(_gr_fp); 165 return(1); 166 } 167 _gr_fp = fopen(_PATH_GROUP, "r"); 168 if(!_gr_fp) return 0; 169 #ifdef YP 170 /* 171 * This is a disgusting hack, used to determine when YP is enabled. 172 * This would be easier if we had a group database to go along with 173 * the password database. 174 */ 175 { 176 char *line; 177 size_t linelen; 178 _gr_yp_enabled = 0; 179 while((line = fgetln(_gr_fp, &linelen)) != NULL) { 180 if(line[0] == '+') { 181 if(line[1] && line[1] != ':' && !_gr_yp_enabled) { 182 _gr_yp_enabled = 1; 183 } else { 184 _gr_yp_enabled = -1; 185 break; 186 } 187 } 188 } 189 rewind(_gr_fp); 190 } 191 #endif 192 193 if (maxlinelength == 0) { 194 if ((line = (char *)malloc(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 } 208 209 int 210 setgrent(void) 211 { 212 return setgroupent(0); 213 } 214 215 int 216 setgroupent(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 } 227 228 void 229 endgrent() 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 } 239 240 static int 241 grscan(search, gid, name) 242 int search, gid; 243 char *name; 244 { 245 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 *)reallocf(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 reallocf(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 416 417 static 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 **)reallocf(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 } 469 470 static char *_gr_yp_domain; 471 472 static 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 } 498 499 500 static 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 { 525 tryagain: 526 lastkey = key; 527 rv = yp_next(_gr_yp_domain, "group.byname", key, keylen, 528 &key, &keylen, &result, &resultlen); 529 free(lastkey); 530 unpack: 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