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 static int lockfd = -1;
48 static char group_dir[PATH_MAX];
49 static char group_file[PATH_MAX];
50 static char tempname[PATH_MAX];
51 static int initialized;
52 static size_t grmemlen(const struct group *, const char *, int *);
53 static struct group *grcopy(const struct group *gr, char *mem, const char *, int ndx);
59 gr_init(const char *dir, const char *group)
63 strcpy(group_dir, _PATH_ETC);
65 if (strlen(dir) >= sizeof(group_dir)) {
69 strcpy(group_dir, dir);
74 strcpy(group_file, _PATH_GROUP);
75 } else if (snprintf(group_file, sizeof(group_file), "%s/group",
76 group_dir) > (int)sizeof(group_file)) {
81 if (strlen(group) >= sizeof(group_file)) {
85 strcpy(group_file, group);
98 if (*group_file == '\0')
104 lockfd = flopen(group_file, O_RDONLY|O_NONBLOCK|O_CLOEXEC, 0);
106 if (errno == EWOULDBLOCK) {
107 errx(1, "the group file is busy");
109 err(1, "could not lock the group file: ");
112 if (fstat(lockfd, &st) == -1)
113 err(1, "fstat() failed: ");
114 if (st.st_nlink != 0)
123 * Create and open a presmuably safe temp file for editing group data
133 if (*group_file == '\0')
135 if ((p = strrchr(group_file, '/')))
139 if (snprintf(tempname, sizeof(tempname), "%.*sgroup.XXXXXX",
140 (int)(p - group_file), group_file) >= (int)sizeof(tempname)) {
141 errno = ENAMETOOLONG;
144 if ((tfd = mkstemp(tempname)) == -1)
147 while ((nr = read(mfd, buf, sizeof(buf))) > 0)
148 if (write(tfd, buf, (size_t)nr) != nr)
161 * Copy the group file from one descriptor to another, replacing, deleting
162 * or adding a single record on the way.
165 gr_copy(int ffd, int tfd, const struct group *gr, struct group *old_gr)
167 char buf[8192], *end, *line, *p, *q, *r, t;
169 const struct group *sgr;
179 } else if ((line = gr_make(gr)) == NULL)
186 /* find the end of the current line */
187 for (p = q; q < end && *q != '\0'; ++q)
191 /* if we don't have a complete line, fill up the buffer */
195 if ((size_t)(q - p) >= sizeof(buf)) {
196 warnx("group line too long");
197 errno = EINVAL; /* hack */
201 q = memmove(buf, p, end -p);
206 readlen = read(ffd, end, sizeof(buf) - (end -buf));
210 len = (size_t)readlen;
211 if (len == 0 && p == buf)
215 if (len < (ssize_t)sizeof(buf)) {
217 if (len > 0 && buf[len -1] != '\n')
218 ++len, *end++ = '\n';
223 /* is it a blank line or a comment? */
224 for (r = p; r < q && isspace(*r); ++r)
226 if (r == q || *r == '#') {
228 if (write(tfd, p, q -p + 1) != q - p + 1)
234 /* is it the one we're looking for? */
241 /* fgr is either a struct group for the current line,
242 * or NULL if the line is malformed.
246 if (fgr == NULL || fgr->gr_gid != sgr->gr_gid) {
250 if (write(tfd, p, q - p + 1) != q - p + 1)
255 if (old_gr && !gr_equal(fgr, old_gr)) {
256 warnx("entry inconsistent");
258 errno = EINVAL; /* hack */
263 /* it is, replace or remove it */
266 if (write(tfd, line, len) != (int) len)
269 /* when removed, avoid the \n */
272 /* we're done, just copy the rest over */
274 if (write(tfd, q, end - q) != end - q)
277 readlen = read(ffd, buf, sizeof(buf));
281 len = (size_t)readlen;
289 /* if we got here, we didn't find the old entry */
295 if ((size_t)write(tfd, line, len) != len ||
296 write(tfd, "\n", 1) != 1)
309 * Regenerate the group file
314 if (chmod(tempname, 0644) != 0)
317 return (rename(tempname, group_file));
321 * Clean up. Preserves errno for the caller's convenience.
332 if (*tempname != '\0') {
342 * Compares two struct group's.
345 gr_equal(const struct group *gr1, const struct group *gr2)
350 /* Check that the non-member information is the same. */
351 if (gr1->gr_name == NULL || gr2->gr_name == NULL) {
352 if (gr1->gr_name != gr2->gr_name)
354 } else if (strcmp(gr1->gr_name, gr2->gr_name) != 0)
356 if (gr1->gr_passwd == NULL || gr2->gr_passwd == NULL) {
357 if (gr1->gr_passwd != gr2->gr_passwd)
359 } else if (strcmp(gr1->gr_passwd, gr2->gr_passwd) != 0)
361 if (gr1->gr_gid != gr2->gr_gid)
364 /* Check all members in both groups.
365 * getgrnam can return gr_mem with a pointer to NULL.
366 * gr_dup and gr_add strip out this superfluous NULL, setting
367 * gr_mem to NULL for no members.
369 if (gr1->gr_mem != NULL && gr2->gr_mem != NULL) {
372 for (i = 0; gr1->gr_mem[i] != NULL; i++) {
373 if (strcmp(gr1->gr_mem[i], gr2->gr_mem[i]) != 0)
377 /* Count number of members in both structs */
379 if (gr2->gr_mem != NULL)
380 for(; gr2->gr_mem[gr2_ndx] != NULL; gr2_ndx++)
383 if (gr1->gr_mem != NULL)
384 for(; gr1->gr_mem[gr1_ndx] != NULL; gr1_ndx++)
386 if (gr1_ndx != gr2_ndx)
393 * Make a group line out of a struct group.
396 gr_make(const struct group *gr)
398 const char *group_line_format = "%s:%s:%ju:";
405 /* Calculate the length of the group line. */
406 line_size = snprintf(NULL, 0, group_line_format, gr->gr_name,
407 gr->gr_passwd, (uintmax_t)gr->gr_gid) + 1;
408 if (gr->gr_mem != NULL) {
409 for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++)
410 line_size += strlen(gr->gr_mem[ndx]) + 1;
415 /* Create the group line and fill it. */
416 if ((line = p = malloc(line_size)) == NULL)
418 p += sprintf(p, group_line_format, gr->gr_name, gr->gr_passwd,
419 (uintmax_t)gr->gr_gid);
420 if (gr->gr_mem != NULL) {
422 for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
424 p = stpcpy(p, gr->gr_mem[ndx]);
433 * Duplicate a struct group.
436 gr_dup(const struct group *gr)
438 return (gr_add(gr, NULL));
441 * Add a new member name to a struct group.
444 gr_add(const struct group *gr, const char *newmember)
451 len = grmemlen(gr, newmember, &num_mem);
452 /* Create new group and copy old group into it. */
453 if ((mem = malloc(len)) == NULL)
455 return (grcopy(gr, mem, newmember, num_mem));
458 /* It is safer to walk the pointers given at gr_mem since there is no
459 * guarantee the gr_mem + strings are contiguous in the given struct group
460 * but compactify the new group into the following form.
462 * The new struct is laid out like this in memory. The example given is
463 * for a group with two members only.
469 * (gr_mem * newgrp + sizeof(struct group) + sizeof(**)) points to gr_mem area
481 * Copy the contents of a group plus given name to a preallocated group struct
483 static struct group *
484 grcopy(const struct group *gr, char *dst, const char *name, int ndx)
489 newgr = (struct group *)(void *)dst; /* avoid alignment warning */
490 dst += sizeof(*newgr);
492 newgr->gr_mem = (char **)(void *)(dst); /* avoid alignment warning */
493 dst += (ndx + 1) * sizeof(*newgr->gr_mem);
495 newgr->gr_mem = NULL;
496 if (gr->gr_name != NULL) {
497 newgr->gr_name = dst;
498 dst = stpcpy(dst, gr->gr_name) + 1;
500 newgr->gr_name = NULL;
501 if (gr->gr_passwd != NULL) {
502 newgr->gr_passwd = dst;
503 dst = stpcpy(dst, gr->gr_passwd) + 1;
505 newgr->gr_passwd = NULL;
506 newgr->gr_gid = gr->gr_gid;
508 /* Original group struct might have a NULL gr_mem */
509 if (gr->gr_mem != NULL) {
510 for (; gr->gr_mem[i] != NULL; i++) {
511 newgr->gr_mem[i] = dst;
512 dst = stpcpy(dst, gr->gr_mem[i]) + 1;
515 /* If name is not NULL, newgr->gr_mem is known to be not NULL */
517 newgr->gr_mem[i++] = dst;
518 dst = stpcpy(dst, name) + 1;
520 /* if newgr->gr_mem is not NULL add NULL marker */
521 if (newgr->gr_mem != NULL)
522 newgr->gr_mem[i] = NULL;
528 * Calculate length of a struct group + given name
531 grmemlen(const struct group *gr, const char *name, int *num_mem)
538 /* Calculate size of the group. */
540 if (gr->gr_name != NULL)
541 len += strlen(gr->gr_name) + 1;
542 if (gr->gr_passwd != NULL)
543 len += strlen(gr->gr_passwd) + 1;
545 if (gr->gr_mem != NULL) {
546 for (; gr->gr_mem[i] != NULL; i++) {
547 len += strlen(gr->gr_mem[i]) + 1;
548 len += sizeof(*gr->gr_mem);
553 len += strlen(name) + 1;
554 len += sizeof(*gr->gr_mem);
556 /* Allow for NULL pointer */
558 len += sizeof(*gr->gr_mem);
564 * Scan a line and place it into a group structure.
567 __gr_scan(char *line, struct group *gr)
572 /* Assign non-member information to structure. */
574 if ((loc = strchr(line, ':')) == NULL)
577 gr->gr_passwd = loc + 1;
578 if (*gr->gr_passwd == ':')
579 *gr->gr_passwd = '\0';
581 if ((loc = strchr(loc + 1, ':')) == NULL)
585 if (sscanf(loc + 1, "%u", &gr->gr_gid) != 1)
588 /* Assign member information to structure. */
589 if ((loc = strchr(loc + 1, ':')) == NULL)
595 gr->gr_mem = reallocf(gr->gr_mem, sizeof(*gr->gr_mem) *
597 if (gr->gr_mem == NULL)
600 /* Skip locations without members (i.e., empty string). */
602 gr->gr_mem[ndx] = strsep(&line, ",");
603 } while (gr->gr_mem[ndx] != NULL && *gr->gr_mem[ndx] == '\0');
604 } while (gr->gr_mem[ndx++] != NULL);
610 * Create a struct group from a line.
613 gr_scan(const char *line)
617 struct group *new_gr;
619 if ((line_copy = strdup(line)) == NULL)
621 if (!__gr_scan(line_copy, &gr)) {
625 new_gr = gr_dup(&gr);
627 if (gr.gr_mem != NULL)