gr_util.c revision 245390
1193326Sed/*- 2193326Sed * Copyright (c) 2008 Sean C. Farley <scf@FreeBSD.org> 3193326Sed * All rights reserved. 4193326Sed * 5193326Sed * Redistribution and use in source and binary forms, with or without 6193326Sed * modification, are permitted provided that the following conditions 7193326Sed * are met: 8193326Sed * 1. Redistributions of source code must retain the above copyright 9193326Sed * notice, this list of conditions and the following disclaimer, 10198092Srdivacky * without modification, immediately at the beginning of the file. 11193326Sed * 2. Redistributions in binary form must reproduce the above copyright 12193326Sed * notice, this list of conditions and the following disclaimer in the 13193326Sed * documentation and/or other materials provided with the distribution. 14193326Sed * 15193326Sed * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16193326Sed * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17198092Srdivacky * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18193326Sed * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19193326Sed * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20193326Sed * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21193326Sed * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22203955Srdivacky * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23193326Sed * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24193326Sed * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25193326Sed */ 26193326Sed 27193326Sed#include <sys/cdefs.h> 28193326Sed__FBSDID("$FreeBSD: head/lib/libutil/gr_util.c 245390 2013-01-13 22:08:18Z mjg $"); 29193326Sed 30193326Sed#include <sys/param.h> 31198092Srdivacky#include <sys/errno.h> 32193326Sed#include <sys/stat.h> 33193326Sed 34193326Sed#include <ctype.h> 35193326Sed#include <err.h> 36193326Sed#include <fcntl.h> 37204643Srdivacky#include <grp.h> 38199990Srdivacky#include <inttypes.h> 39199990Srdivacky#include <libutil.h> 40193326Sed#include <paths.h> 41193326Sed#include <stdbool.h> 42193326Sed#include <stdio.h> 43193326Sed#include <stdlib.h> 44193326Sed#include <string.h> 45193326Sed#include <unistd.h> 46193326Sed 47193326Sedstatic int lockfd = -1; 48193326Sedstatic char group_dir[PATH_MAX]; 49193326Sedstatic char group_file[PATH_MAX]; 50193326Sedstatic char tempname[PATH_MAX]; 51204643Srdivackystatic int initialized; 52193326Sed 53193326Sed/* 54206084Srdivacky * Initialize statics 55193326Sed */ 56193326Sedint 57193326Sedgr_init(const char *dir, const char *group) 58193326Sed{ 59193326Sed 60199482Srdivacky if (dir == NULL) { 61193326Sed strcpy(group_dir, _PATH_ETC); 62193326Sed } else { 63202379Srdivacky if (strlen(dir) >= sizeof(group_dir)) { 64198092Srdivacky errno = ENAMETOOLONG; 65193326Sed return (-1); 66193326Sed } 67193326Sed strcpy(group_dir, dir); 68193326Sed } 69193326Sed 70193326Sed if (group == NULL) { 71193326Sed if (dir == NULL) { 72193326Sed strcpy(group_file, _PATH_GROUP); 73193326Sed } else if (snprintf(group_file, sizeof(group_file), "%s/group", 74193326Sed group_dir) > (int)sizeof(group_file)) { 75193326Sed errno = ENAMETOOLONG; 76193326Sed return (-1); 77193326Sed } 78198092Srdivacky } else { 79198092Srdivacky if (strlen(group) >= sizeof(group_file)) { 80193326Sed errno = ENAMETOOLONG; 81193326Sed return (-1); 82193326Sed } 83193326Sed strcpy(group_file, group); 84193326Sed } 85193326Sed 86193326Sed initialized = 1; 87193326Sed return (0); 88198092Srdivacky} 89193326Sed 90193326Sed/* 91193326Sed * Lock the group file 92193326Sed */ 93193326Sedint 94193326Sedgr_lock(void) 95193326Sed{ 96193326Sed if (*group_file == '\0') 97193326Sed return (-1); 98202379Srdivacky 99202379Srdivacky for (;;) { 100193326Sed struct stat st; 101198092Srdivacky 102193326Sed lockfd = flopen(group_file, O_RDONLY|O_NONBLOCK|O_CLOEXEC, 0); 103199482Srdivacky if (lockfd == -1) { 104193326Sed if (errno == EWOULDBLOCK) { 105202379Srdivacky errx(1, "the group file is busy"); 106198092Srdivacky } else { 107193326Sed err(1, "could not lock the group file: "); 108198092Srdivacky } 109193326Sed } 110193326Sed if (fstat(lockfd, &st) == -1) 111198092Srdivacky err(1, "fstat() failed: "); 112193326Sed if (st.st_nlink != 0) 113193326Sed break; 114193326Sed close(lockfd); 115193326Sed lockfd = -1; 116193326Sed } 117193326Sed return (lockfd); 118193326Sed} 119193326Sed 120193326Sed/* 121193326Sed * Create and open a presmuably safe temp file for editing group data 122198092Srdivacky */ 123204643Srdivackyint 124199990Srdivackygr_tmp(int mfd) 125204643Srdivacky{ 126207619Srdivacky char buf[8192]; 127199990Srdivacky ssize_t nr; 128199990Srdivacky const char *p; 129207619Srdivacky int tfd; 130199990Srdivacky 131206084Srdivacky if (*group_file == '\0') 132198092Srdivacky return (-1); 133193326Sed if ((p = strrchr(group_file, '/'))) 134193326Sed ++p; 135193326Sed else 136193326Sed p = group_file; 137198092Srdivacky if (snprintf(tempname, sizeof(tempname), "%.*sgroup.XXXXXX", 138203955Srdivacky (int)(p - group_file), group_file) >= (int)sizeof(tempname)) { 139203955Srdivacky errno = ENAMETOOLONG; 140193326Sed return (-1); 141193326Sed } 142193326Sed if ((tfd = mkstemp(tempname)) == -1) 143199990Srdivacky return (-1); 144199990Srdivacky if (mfd != -1) { 145199990Srdivacky while ((nr = read(mfd, buf, sizeof(buf))) > 0) 146199990Srdivacky if (write(tfd, buf, (size_t)nr) != nr) 147199990Srdivacky break; 148203955Srdivacky if (nr != 0) { 149203955Srdivacky unlink(tempname); 150203955Srdivacky *tempname = '\0'; 151206084Srdivacky close(tfd); 152203955Srdivacky return (-1); 153204643Srdivacky } 154204643Srdivacky } 155203955Srdivacky return (tfd); 156198092Srdivacky} 157198092Srdivacky 158198092Srdivacky/* 159198092Srdivacky * Copy the group file from one descriptor to another, replacing, deleting 160198092Srdivacky * or adding a single record on the way. 161198092Srdivacky */ 162198092Srdivackyint 163198092Srdivackygr_copy(int ffd, int tfd, const struct group *gr, struct group *old_gr) 164198092Srdivacky{ 165206084Srdivacky char buf[8192], *end, *line, *p, *q, *r, t; 166198092Srdivacky struct group *fgr; 167198092Srdivacky const struct group *sgr; 168206084Srdivacky size_t len; 169204643Srdivacky int eof, readlen; 170204643Srdivacky 171204643Srdivacky sgr = gr; 172204643Srdivacky if (gr == NULL) { 173204643Srdivacky line = NULL; 174204643Srdivacky if (old_gr == NULL) 175206084Srdivacky return (-1); 176198092Srdivacky sgr = old_gr; 177206084Srdivacky } else if ((line = gr_make(gr)) == NULL) 178206084Srdivacky return (-1); 179206084Srdivacky 180193326Sed eof = 0; 181193326Sed len = 0; 182193326Sed p = q = end = buf; 183193326Sed for (;;) { 184193326Sed /* find the end of the current line */ 185193326Sed for (p = q; q < end && *q != '\0'; ++q) 186193326Sed if (*q == '\n') 187193326Sed break; 188193326Sed 189193326Sed /* if we don't have a complete line, fill up the buffer */ 190193326Sed if (q >= end) { 191193326Sed if (eof) 192193326Sed break; 193193326Sed if ((size_t)(q - p) >= sizeof(buf)) { 194193326Sed warnx("group line too long"); 195 errno = EINVAL; /* hack */ 196 goto err; 197 } 198 if (p < end) { 199 q = memmove(buf, p, end -p); 200 end -= p - buf; 201 } else { 202 p = q = end = buf; 203 } 204 readlen = read(ffd, end, sizeof(buf) - (end -buf)); 205 if (readlen == -1) 206 goto err; 207 else 208 len = (size_t)readlen; 209 if (len == 0 && p == buf) 210 break; 211 end += len; 212 len = end - buf; 213 if (len < (ssize_t)sizeof(buf)) { 214 eof = 1; 215 if (len > 0 && buf[len -1] != '\n') 216 ++len, *end++ = '\n'; 217 } 218 continue; 219 } 220 221 /* is it a blank line or a comment? */ 222 for (r = p; r < q && isspace(*r); ++r) 223 /* nothing */; 224 if (r == q || *r == '#') { 225 /* yep */ 226 if (write(tfd, p, q -p + 1) != q - p + 1) 227 goto err; 228 ++q; 229 continue; 230 } 231 232 /* is it the one we're looking for? */ 233 234 t = *q; 235 *q = '\0'; 236 237 fgr = gr_scan(r); 238 239 /* fgr is either a struct group for the current line, 240 * or NULL if the line is malformed. 241 */ 242 243 *q = t; 244 if (fgr == NULL || fgr->gr_gid != sgr->gr_gid) { 245 /* nope */ 246 if (fgr != NULL) 247 free(fgr); 248 if (write(tfd, p, q - p + 1) != q - p + 1) 249 goto err; 250 ++q; 251 continue; 252 } 253 if (old_gr && !gr_equal(fgr, old_gr)) { 254 warnx("entry inconsistent"); 255 free(fgr); 256 errno = EINVAL; /* hack */ 257 goto err; 258 } 259 free(fgr); 260 261 /* it is, replace or remove it */ 262 if (line != NULL) { 263 len = strlen(line); 264 if (write(tfd, line, len) != (int) len) 265 goto err; 266 } else { 267 /* when removed, avoid the \n */ 268 q++; 269 } 270 /* we're done, just copy the rest over */ 271 for (;;) { 272 if (write(tfd, q, end - q) != end - q) 273 goto err; 274 q = buf; 275 readlen = read(ffd, buf, sizeof(buf)); 276 if (readlen == 0) 277 break; 278 else 279 len = (size_t)readlen; 280 if (readlen == -1) 281 goto err; 282 end = buf + len; 283 } 284 goto done; 285 } 286 287 /* if we got here, we didn't find the old entry */ 288 if (line == NULL) { 289 errno = ENOENT; 290 goto err; 291 } 292 len = strlen(line); 293 if ((size_t)write(tfd, line, len) != len || 294 write(tfd, "\n", 1) != 1) 295 goto err; 296 done: 297 if (line != NULL) 298 free(line); 299 return (0); 300 err: 301 if (line != NULL) 302 free(line); 303 return (-1); 304} 305 306/* 307 * Regenerate the group file 308 */ 309int 310gr_mkdb(void) 311{ 312 if (chmod(tempname, 0644) != 0) 313 return (-1); 314 315 return (rename(tempname, group_file)); 316} 317 318/* 319 * Clean up. Preserves errno for the caller's convenience. 320 */ 321void 322gr_fini(void) 323{ 324 int serrno; 325 326 if (!initialized) 327 return; 328 initialized = 0; 329 serrno = errno; 330 if (*tempname != '\0') { 331 unlink(tempname); 332 *tempname = '\0'; 333 } 334 if (lockfd != -1) 335 close(lockfd); 336 errno = serrno; 337} 338 339/* 340 * Compares two struct group's. 341 */ 342int 343gr_equal(const struct group *gr1, const struct group *gr2) 344{ 345 int gr1_ndx; 346 int gr2_ndx; 347 348 /* Check that the non-member information is the same. */ 349 if (gr1->gr_name == NULL || gr2->gr_name == NULL) { 350 if (gr1->gr_name != gr2->gr_name) 351 return (false); 352 } else if (strcmp(gr1->gr_name, gr2->gr_name) != 0) 353 return (false); 354 if (gr1->gr_passwd == NULL || gr2->gr_passwd == NULL) { 355 if (gr1->gr_passwd != gr2->gr_passwd) 356 return (false); 357 } else if (strcmp(gr1->gr_passwd, gr2->gr_passwd) != 0) 358 return (false); 359 if (gr1->gr_gid != gr2->gr_gid) 360 return (false); 361 362 /* Check all members in both groups. */ 363 if (gr1->gr_mem == NULL || gr2->gr_mem == NULL) { 364 if (gr1->gr_mem != gr2->gr_mem) 365 return (false); 366 } else { 367 for (gr1_ndx = 0; gr1->gr_mem[gr1_ndx] != NULL; gr1_ndx++) { 368 for (gr2_ndx = 0;; gr2_ndx++) { 369 if (gr2->gr_mem[gr2_ndx] == NULL) 370 return (false); 371 if (strcmp(gr1->gr_mem[gr1_ndx], 372 gr2->gr_mem[gr2_ndx]) == 0) { 373 break; 374 } 375 } 376 } 377 378 /* Check that group2 does not have more members than group1. */ 379 if (gr2->gr_mem[gr1_ndx] != NULL) 380 return (false); 381 } 382 383 return (true); 384} 385 386/* 387 * Make a group line out of a struct group. 388 */ 389char * 390gr_make(const struct group *gr) 391{ 392 const char *group_line_format = "%s:%s:%ju:"; 393 const char *sep; 394 char *line; 395 char *p; 396 size_t line_size; 397 int ndx; 398 399 /* Calculate the length of the group line. */ 400 line_size = snprintf(NULL, 0, group_line_format, gr->gr_name, 401 gr->gr_passwd, (uintmax_t)gr->gr_gid) + 1; 402 if (gr->gr_mem != NULL) { 403 for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) 404 line_size += strlen(gr->gr_mem[ndx]) + 1; 405 if (ndx > 0) 406 line_size--; 407 } 408 409 /* Create the group line and fill it. */ 410 if ((line = p = malloc(line_size)) == NULL) 411 return (NULL); 412 p += sprintf(p, group_line_format, gr->gr_name, gr->gr_passwd, 413 (uintmax_t)gr->gr_gid); 414 if (gr->gr_mem != NULL) { 415 sep = ""; 416 for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) { 417 p = stpcpy(p, sep); 418 p = stpcpy(p, gr->gr_mem[ndx]); 419 sep = ","; 420 } 421 } 422 423 return (line); 424} 425 426/* 427 * Duplicate a struct group. 428 */ 429struct group * 430gr_dup(const struct group *gr) 431{ 432 struct group *newgr; 433 char *dst; 434 size_t len; 435 int ndx; 436 int num_mem; 437 438 /* Calculate size of the group. */ 439 len = sizeof(*newgr); 440 if (gr->gr_name != NULL) 441 len += strlen(gr->gr_name) + 1; 442 if (gr->gr_passwd != NULL) 443 len += strlen(gr->gr_passwd) + 1; 444 if (gr->gr_mem != NULL) { 445 for (num_mem = 0; gr->gr_mem[num_mem] != NULL; num_mem++) 446 len += strlen(gr->gr_mem[num_mem]) + 1; 447 len += (num_mem + 1) * sizeof(*gr->gr_mem); 448 } else 449 num_mem = -1; 450 /* Create new group and copy old group into it. */ 451 if ((newgr = malloc(len)) == NULL) 452 return (NULL); 453 /* point new gr_mem to end of struct + 1 */ 454 if (gr->gr_mem != NULL) 455 newgr->gr_mem = (char **)(newgr + 1); 456 else 457 newgr->gr_mem = NULL; 458 /* point dst after the end of all the gr_mem pointers in newgr */ 459 dst = (char *)&newgr->gr_mem[num_mem + 1]; 460 if (gr->gr_name != NULL) { 461 newgr->gr_name = dst; 462 dst = stpcpy(dst, gr->gr_name) + 1; 463 } else { 464 newgr->gr_name = NULL; 465 } 466 if (gr->gr_passwd != NULL) { 467 newgr->gr_passwd = dst; 468 dst = stpcpy(dst, gr->gr_passwd) + 1; 469 } else { 470 newgr->gr_passwd = NULL; 471 } 472 newgr->gr_gid = gr->gr_gid; 473 if (gr->gr_mem != NULL) { 474 for (ndx = 0; ndx < num_mem; ndx++) { 475 newgr->gr_mem[ndx] = dst; 476 dst = stpcpy(dst, gr->gr_mem[ndx]) + 1; 477 } 478 newgr->gr_mem[ndx] = NULL; 479 } 480 return (newgr); 481} 482 483/* 484 * Add a new member name to a struct group. 485 */ 486struct group * 487gr_add(struct group *gr, char *newmember) 488{ 489 size_t mlen; 490 int num_mem=0; 491 char **members; 492 struct group *newgr; 493 494 if (newmember == NULL) 495 return(gr_dup(gr)); 496 497 if (gr->gr_mem != NULL) { 498 for (num_mem = 0; gr->gr_mem[num_mem] != NULL; num_mem++) { 499 if (strcmp(gr->gr_mem[num_mem], newmember) == 0) { 500 errno = EEXIST; 501 return (NULL); 502 } 503 } 504 } 505 /* Allocate enough for current pointers + 1 more and NULL marker */ 506 mlen = (num_mem + 2) * sizeof(*gr->gr_mem); 507 if ((members = malloc(mlen)) == NULL) 508 return (NULL); 509 memcpy(members, gr->gr_mem, num_mem * sizeof(*gr->gr_mem)); 510 members[num_mem++] = newmember; 511 members[num_mem] = NULL; 512 gr->gr_mem = members; 513 newgr = gr_dup(gr); 514 free(members); 515 return (newgr); 516} 517 518/* 519 * Scan a line and place it into a group structure. 520 */ 521static bool 522__gr_scan(char *line, struct group *gr) 523{ 524 char *loc; 525 int ndx; 526 527 /* Assign non-member information to structure. */ 528 gr->gr_name = line; 529 if ((loc = strchr(line, ':')) == NULL) 530 return (false); 531 *loc = '\0'; 532 gr->gr_passwd = loc + 1; 533 if (*gr->gr_passwd == ':') 534 *gr->gr_passwd = '\0'; 535 else { 536 if ((loc = strchr(loc + 1, ':')) == NULL) 537 return (false); 538 *loc = '\0'; 539 } 540 if (sscanf(loc + 1, "%u", &gr->gr_gid) != 1) 541 return (false); 542 543 /* Assign member information to structure. */ 544 if ((loc = strchr(loc + 1, ':')) == NULL) 545 return (false); 546 line = loc + 1; 547 gr->gr_mem = NULL; 548 ndx = 0; 549 do { 550 gr->gr_mem = reallocf(gr->gr_mem, sizeof(*gr->gr_mem) * 551 (ndx + 1)); 552 if (gr->gr_mem == NULL) 553 return (false); 554 555 /* Skip locations without members (i.e., empty string). */ 556 do { 557 gr->gr_mem[ndx] = strsep(&line, ","); 558 } while (gr->gr_mem[ndx] != NULL && *gr->gr_mem[ndx] == '\0'); 559 } while (gr->gr_mem[ndx++] != NULL); 560 561 return (true); 562} 563 564/* 565 * Create a struct group from a line. 566 */ 567struct group * 568gr_scan(const char *line) 569{ 570 struct group gr; 571 char *line_copy; 572 struct group *new_gr; 573 574 if ((line_copy = strdup(line)) == NULL) 575 return (NULL); 576 if (!__gr_scan(line_copy, &gr)) { 577 free(line_copy); 578 return (NULL); 579 } 580 new_gr = gr_dup(&gr); 581 free(line_copy); 582 if (gr.gr_mem != NULL) 583 free(gr.gr_mem); 584 585 return (new_gr); 586} 587