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;
173 if (old_gr == NULL && gr == NULL)
177 /* deleting a group */
181 if ((line = gr_make(gr)) == NULL)
193 /* find the end of the current line */
194 for (p = q; q < end && *q != '\0'; ++q)
198 /* if we don't have a complete line, fill up the buffer */
202 if ((size_t)(q - p) >= sizeof(buf)) {
203 warnx("group line too long");
204 errno = EINVAL; /* hack */
208 q = memmove(buf, p, end -p);
213 readlen = read(ffd, end, sizeof(buf) - (end -buf));
217 len = (size_t)readlen;
218 if (len == 0 && p == buf)
222 if (len < (ssize_t)sizeof(buf)) {
224 if (len > 0 && buf[len -1] != '\n')
225 ++len, *end++ = '\n';
230 /* is it a blank line or a comment? */
231 for (r = p; r < q && isspace(*r); ++r)
233 if (r == q || *r == '#') {
235 if (write(tfd, p, q -p + 1) != q - p + 1)
241 /* is it the one we're looking for? */
248 /* fgr is either a struct group for the current line,
249 * or NULL if the line is malformed.
253 if (fgr == NULL || fgr->gr_gid != sgr->gr_gid) {
257 if (write(tfd, p, q - p + 1) != q - p + 1)
262 if (old_gr && !gr_equal(fgr, old_gr)) {
263 warnx("entry inconsistent");
265 errno = EINVAL; /* hack */
270 /* it is, replace or remove it */
273 if (write(tfd, line, len) != (int) len)
276 /* when removed, avoid the \n */
279 /* we're done, just copy the rest over */
281 if (write(tfd, q, end - q) != end - q)
284 readlen = read(ffd, buf, sizeof(buf));
288 len = (size_t)readlen;
296 /* if we got here, we didn't find the old entry */
302 if ((size_t)write(tfd, line, len) != len ||
303 write(tfd, "\n", 1) != 1)
316 * Regenerate the group file
321 if (chmod(tempname, 0644) != 0)
324 return (rename(tempname, group_file));
328 * Clean up. Preserves errno for the caller's convenience.
339 if (*tempname != '\0') {
349 * Compares two struct group's.
352 gr_equal(const struct group *gr1, const struct group *gr2)
357 /* Check that the non-member information is the same. */
358 if (gr1->gr_name == NULL || gr2->gr_name == NULL) {
359 if (gr1->gr_name != gr2->gr_name)
361 } else if (strcmp(gr1->gr_name, gr2->gr_name) != 0)
363 if (gr1->gr_passwd == NULL || gr2->gr_passwd == NULL) {
364 if (gr1->gr_passwd != gr2->gr_passwd)
366 } else if (strcmp(gr1->gr_passwd, gr2->gr_passwd) != 0)
368 if (gr1->gr_gid != gr2->gr_gid)
371 /* Check all members in both groups.
372 * getgrnam can return gr_mem with a pointer to NULL.
373 * gr_dup and gr_add strip out this superfluous NULL, setting
374 * gr_mem to NULL for no members.
376 if (gr1->gr_mem != NULL && gr2->gr_mem != NULL) {
379 for (i = 0; gr1->gr_mem[i] != NULL; i++) {
380 if (strcmp(gr1->gr_mem[i], gr2->gr_mem[i]) != 0)
384 /* Count number of members in both structs */
386 if (gr2->gr_mem != NULL)
387 for(; gr2->gr_mem[gr2_ndx] != NULL; gr2_ndx++)
390 if (gr1->gr_mem != NULL)
391 for(; gr1->gr_mem[gr1_ndx] != NULL; gr1_ndx++)
393 if (gr1_ndx != gr2_ndx)
400 * Make a group line out of a struct group.
403 gr_make(const struct group *gr)
405 const char *group_line_format = "%s:%s:%ju:";
412 /* Calculate the length of the group line. */
413 line_size = snprintf(NULL, 0, group_line_format, gr->gr_name,
414 gr->gr_passwd, (uintmax_t)gr->gr_gid) + 1;
415 if (gr->gr_mem != NULL) {
416 for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++)
417 line_size += strlen(gr->gr_mem[ndx]) + 1;
422 /* Create the group line and fill it. */
423 if ((line = p = malloc(line_size)) == NULL)
425 p += sprintf(p, group_line_format, gr->gr_name, gr->gr_passwd,
426 (uintmax_t)gr->gr_gid);
427 if (gr->gr_mem != NULL) {
429 for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
431 p = stpcpy(p, gr->gr_mem[ndx]);
440 * Duplicate a struct group.
443 gr_dup(const struct group *gr)
445 return (gr_add(gr, NULL));
448 * Add a new member name to a struct group.
451 gr_add(const struct group *gr, const char *newmember)
458 len = grmemlen(gr, newmember, &num_mem);
459 /* Create new group and copy old group into it. */
460 if ((mem = malloc(len)) == NULL)
462 return (grcopy(gr, mem, newmember, num_mem));
465 /* It is safer to walk the pointers given at gr_mem since there is no
466 * guarantee the gr_mem + strings are contiguous in the given struct group
467 * but compactify the new group into the following form.
469 * The new struct is laid out like this in memory. The example given is
470 * for a group with two members only.
476 * (gr_mem * newgrp + sizeof(struct group) + sizeof(**)) points to gr_mem area
488 * Copy the contents of a group plus given name to a preallocated group struct
490 static struct group *
491 grcopy(const struct group *gr, char *dst, const char *name, int ndx)
496 newgr = (struct group *)(void *)dst; /* avoid alignment warning */
497 dst += sizeof(*newgr);
499 newgr->gr_mem = (char **)(void *)(dst); /* avoid alignment warning */
500 dst += (ndx + 1) * sizeof(*newgr->gr_mem);
502 newgr->gr_mem = NULL;
503 if (gr->gr_name != NULL) {
504 newgr->gr_name = dst;
505 dst = stpcpy(dst, gr->gr_name) + 1;
507 newgr->gr_name = NULL;
508 if (gr->gr_passwd != NULL) {
509 newgr->gr_passwd = dst;
510 dst = stpcpy(dst, gr->gr_passwd) + 1;
512 newgr->gr_passwd = NULL;
513 newgr->gr_gid = gr->gr_gid;
515 /* Original group struct might have a NULL gr_mem */
516 if (gr->gr_mem != NULL) {
517 for (; gr->gr_mem[i] != NULL; i++) {
518 newgr->gr_mem[i] = dst;
519 dst = stpcpy(dst, gr->gr_mem[i]) + 1;
522 /* If name is not NULL, newgr->gr_mem is known to be not NULL */
524 newgr->gr_mem[i++] = dst;
525 dst = stpcpy(dst, name) + 1;
527 /* if newgr->gr_mem is not NULL add NULL marker */
528 if (newgr->gr_mem != NULL)
529 newgr->gr_mem[i] = NULL;
535 * Calculate length of a struct group + given name
538 grmemlen(const struct group *gr, const char *name, int *num_mem)
545 /* Calculate size of the group. */
547 if (gr->gr_name != NULL)
548 len += strlen(gr->gr_name) + 1;
549 if (gr->gr_passwd != NULL)
550 len += strlen(gr->gr_passwd) + 1;
552 if (gr->gr_mem != NULL) {
553 for (; gr->gr_mem[i] != NULL; i++) {
554 len += strlen(gr->gr_mem[i]) + 1;
555 len += sizeof(*gr->gr_mem);
560 len += strlen(name) + 1;
561 len += sizeof(*gr->gr_mem);
563 /* Allow for NULL pointer */
565 len += sizeof(*gr->gr_mem);
571 * Scan a line and place it into a group structure.
574 __gr_scan(char *line, struct group *gr)
579 /* Assign non-member information to structure. */
581 if ((loc = strchr(line, ':')) == NULL)
584 gr->gr_passwd = loc + 1;
585 if (*gr->gr_passwd == ':')
586 *gr->gr_passwd = '\0';
588 if ((loc = strchr(loc + 1, ':')) == NULL)
592 if (sscanf(loc + 1, "%u", &gr->gr_gid) != 1)
595 /* Assign member information to structure. */
596 if ((loc = strchr(loc + 1, ':')) == NULL)
602 gr->gr_mem = reallocf(gr->gr_mem, sizeof(*gr->gr_mem) *
604 if (gr->gr_mem == NULL)
607 /* Skip locations without members (i.e., empty string). */
609 gr->gr_mem[ndx] = strsep(&line, ",");
610 } while (gr->gr_mem[ndx] != NULL && *gr->gr_mem[ndx] == '\0');
611 } while (gr->gr_mem[ndx++] != NULL);
617 * Create a struct group from a line.
620 gr_scan(const char *line)
624 struct group *new_gr;
626 if ((line_copy = strdup(line)) == NULL)
628 if (!__gr_scan(line_copy, &gr)) {
632 new_gr = gr_dup(&gr);
634 if (gr.gr_mem != NULL)