2 * Copyright (c) 2008 Sean C. Farley <scf@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer,
10 * without modification, immediately at the beginning of the file.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/errno.h>
47 struct group_storage {
52 static int lockfd = -1;
53 static char group_dir[PATH_MAX];
54 static char group_file[PATH_MAX];
55 static char tempname[PATH_MAX];
56 static int initialized;
58 static const char group_line_format[] = "%s:%s:%ju:";
64 gr_init(const char *dir, const char *group)
67 strcpy(group_dir, _PATH_ETC);
69 if (strlen(dir) >= sizeof(group_dir)) {
73 strcpy(group_dir, dir);
78 strcpy(group_file, _PATH_GROUP);
79 } else if (snprintf(group_file, sizeof(group_file), "%s/group",
80 group_dir) > (int)sizeof(group_file)) {
85 if (strlen(group) >= sizeof(group_file)) {
89 strcpy(group_file, group);
101 if (*group_file == '\0')
107 lockfd = open(group_file, O_RDONLY, 0);
108 if (lockfd < 0 || fcntl(lockfd, F_SETFD, 1) == -1)
109 err(1, "%s", group_file);
110 if (flock(lockfd, LOCK_EX|LOCK_NB) == -1) {
111 if (errno == EWOULDBLOCK) {
112 errx(1, "the group file is busy");
114 err(1, "could not lock the group file: ");
117 if (fstat(lockfd, &st) == -1)
118 err(1, "fstat() failed: ");
119 if (st.st_nlink != 0)
128 * Create and open a presmuably safe temp file for editing group data
138 if (*group_file == '\0')
140 if ((p = strrchr(group_file, '/')))
144 if (snprintf(tempname, sizeof(tempname), "%.*sgroup.XXXXXX",
145 (int)(p - group_file), group_file) >= (int)sizeof(tempname)) {
146 errno = ENAMETOOLONG;
149 if ((tfd = mkstemp(tempname)) == -1)
152 while ((nr = read(mfd, buf, sizeof(buf))) > 0)
153 if (write(tfd, buf, (size_t)nr) != nr)
166 * Copy the group file from one descriptor to another, replacing, deleting
167 * or adding a single record on the way.
170 gr_copy(int ffd, int tfd, const struct group *gr, struct group *old_gr)
172 char buf[8192], *end, *line, *p, *q, *r, t;
174 const struct group *sgr;
184 } else if ((line = gr_make(gr)) == NULL)
191 /* find the end of the current line */
192 for (p = q; q < end && *q != '\0'; ++q)
196 /* if we don't have a complete line, fill up the buffer */
200 if ((size_t)(q - p) >= sizeof(buf)) {
201 warnx("group line too long");
202 errno = EINVAL; /* hack */
206 q = memmove(buf, p, end -p);
211 readlen = read(ffd, end, sizeof(buf) - (end -buf));
215 len = (size_t)readlen;
216 if (len == 0 && p == buf)
220 if (len < (ssize_t)sizeof(buf)) {
222 if (len > 0 && buf[len -1] != '\n')
223 ++len, *end++ = '\n';
228 /* is it a blank line or a comment? */
229 for (r = p; r < q && isspace(*r); ++r)
231 if (r == q || *r == '#') {
233 if (write(tfd, p, q -p + 1) != q - p + 1)
239 /* is it the one we're looking for? */
246 /* fgr is either a struct group for the current line,
247 * or NULL if the line is malformed.
251 if (fgr == NULL || fgr->gr_gid != sgr->gr_gid) {
255 if (write(tfd, p, q - p + 1) != q - p + 1)
260 if (old_gr && !gr_equal(fgr, old_gr)) {
261 warnx("entry inconsistent");
263 errno = EINVAL; /* hack */
268 /* it is, replace or remove it */
271 if (write(tfd, line, len) != (int) len)
274 /* when removed, avoid the \n */
277 /* we're done, just copy the rest over */
279 if (write(tfd, q, end - q) != end - q)
282 readlen = read(ffd, buf, sizeof(buf));
286 len = (size_t)readlen;
294 /* if we got here, we didn't find the old entry */
300 if ((size_t)write(tfd, line, len) != len ||
301 write(tfd, "\n", 1) != 1)
314 * Regenerate the group file
319 return (rename(tempname, group_file));
323 * Clean up. Preserver errno for the caller's convenience.
334 if (*tempname != '\0') {
344 * Compares two struct group's.
347 gr_equal(const struct group *gr1, const struct group *gr2)
353 /* Check that the non-member information is the same. */
354 if (gr1->gr_name == NULL || gr2->gr_name == NULL) {
355 if (gr1->gr_name != gr2->gr_name)
357 } else if (strcmp(gr1->gr_name, gr2->gr_name) != 0)
359 if (gr1->gr_passwd == NULL || gr2->gr_passwd == NULL) {
360 if (gr1->gr_passwd != gr2->gr_passwd)
362 } else if (strcmp(gr1->gr_passwd, gr2->gr_passwd) != 0)
364 if (gr1->gr_gid != gr2->gr_gid)
367 /* Check all members in both groups. */
368 if (gr1->gr_mem == NULL || gr2->gr_mem == NULL) {
369 if (gr1->gr_mem != gr2->gr_mem)
372 for (found = false, gr1_ndx = 0; gr1->gr_mem[gr1_ndx] != NULL;
374 for (gr2_ndx = 0; gr2->gr_mem[gr2_ndx] != NULL;
376 if (strcmp(gr1->gr_mem[gr1_ndx],
377 gr2->gr_mem[gr2_ndx]) == 0) {
385 /* Check that group2 does not have more members than group1. */
386 if (gr2->gr_mem[gr1_ndx] != NULL)
394 * Make a group line out of a struct group.
397 gr_make(const struct group *gr)
403 /* Calculate the length of the group line. */
404 line_size = snprintf(NULL, 0, group_line_format, gr->gr_name,
405 gr->gr_passwd, (uintmax_t)gr->gr_gid) + 1;
406 if (gr->gr_mem != NULL) {
407 for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++)
408 line_size += strlen(gr->gr_mem[ndx]) + 1;
413 /* Create the group line and fill it. */
414 if ((line = malloc(line_size)) == NULL)
416 snprintf(line, line_size, group_line_format, gr->gr_name, gr->gr_passwd,
417 (uintmax_t)gr->gr_gid);
418 if (gr->gr_mem != NULL)
419 for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
420 strcat(line, gr->gr_mem[ndx]);
421 if (gr->gr_mem[ndx + 1] != NULL)
429 * Duplicate a struct group.
432 gr_dup(const struct group *gr)
436 struct group_storage *gs;
440 /* Calculate size of the group. */
442 if (gr->gr_name != NULL)
443 len += strlen(gr->gr_name) + 1;
444 if (gr->gr_passwd != NULL)
445 len += strlen(gr->gr_passwd) + 1;
446 if (gr->gr_mem != NULL) {
447 for (num_mem = 0; gr->gr_mem[num_mem] != NULL; num_mem++)
448 len += strlen(gr->gr_mem[num_mem]) + 1;
449 len += (num_mem + 1) * sizeof(*gr->gr_mem);
453 /* Create new group and copy old group into it. */
454 if ((gs = calloc(1, len)) == NULL)
456 dst = (char *)&gs->members[num_mem + 1];
457 if (gr->gr_name != NULL) {
458 gs->gr.gr_name = dst;
459 dst = stpcpy(gs->gr.gr_name, gr->gr_name) + 1;
461 if (gr->gr_passwd != NULL) {
462 gs->gr.gr_passwd = dst;
463 dst = stpcpy(gs->gr.gr_passwd, gr->gr_passwd) + 1;
465 gs->gr.gr_gid = gr->gr_gid;
466 if (gr->gr_mem != NULL) {
467 gs->gr.gr_mem = gs->members;
468 for (ndx = 0; ndx < num_mem; ndx++) {
469 gs->gr.gr_mem[ndx] = dst;
470 dst = stpcpy(gs->gr.gr_mem[ndx], gr->gr_mem[ndx]) + 1;
472 gs->gr.gr_mem[ndx] = NULL;
479 * Scan a line and place it into a group structure.
482 __gr_scan(char *line, struct group *gr)
487 /* Assign non-member information to structure. */
489 if ((loc = strchr(line, ':')) == NULL)
492 gr->gr_passwd = loc + 1;
493 if (*gr->gr_passwd == ':')
494 *gr->gr_passwd = '\0';
496 if ((loc = strchr(loc + 1, ':')) == NULL)
500 if (sscanf(loc + 1, "%u", &gr->gr_gid) != 1)
503 /* Assign member information to structure. */
504 if ((loc = strchr(loc + 1, ':')) == NULL)
510 gr->gr_mem = reallocf(gr->gr_mem, sizeof(*gr->gr_mem) *
512 if (gr->gr_mem == NULL)
515 /* Skip locations without members (i.e., empty string). */
517 gr->gr_mem[ndx] = strsep(&line, ",");
518 } while (gr->gr_mem[ndx] != NULL && *gr->gr_mem[ndx] == '\0');
519 } while (gr->gr_mem[ndx++] != NULL);
525 * Create a struct group from a line.
528 gr_scan(const char *line)
532 struct group *new_gr;
534 if ((line_copy = strdup(line)) == NULL)
536 if (!__gr_scan(line_copy, &gr)) {
540 new_gr = gr_dup(&gr);
542 if (gr.gr_mem != NULL)