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-rw-r--r--lib/libutil/gr_util.c546
1 files changed, 546 insertions, 0 deletions
diff --git a/lib/libutil/gr_util.c b/lib/libutil/gr_util.c
new file mode 100644
index 0000000..0173595
--- /dev/null
+++ b/lib/libutil/gr_util.c
@@ -0,0 +1,546 @@
+/*-
+ * Copyright (c) 2008 Sean C. Farley <scf@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer,
+ * without modification, immediately at the beginning of the file.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/errno.h>
+#include <sys/stat.h>
+
+#include <ctype.h>
+#include <err.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <inttypes.h>
+#include <libutil.h>
+#include <paths.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+struct group_storage {
+ struct group gr;
+ char *members[];
+};
+
+static int lockfd = -1;
+static char group_dir[PATH_MAX];
+static char group_file[PATH_MAX];
+static char tempname[PATH_MAX];
+static int initialized;
+
+static const char group_line_format[] = "%s:%s:%ju:";
+
+/*
+ * Initialize statics
+ */
+int
+gr_init(const char *dir, const char *group)
+{
+ if (dir == NULL) {
+ strcpy(group_dir, _PATH_ETC);
+ } else {
+ if (strlen(dir) >= sizeof(group_dir)) {
+ errno = ENAMETOOLONG;
+ return (-1);
+ }
+ strcpy(group_dir, dir);
+ }
+
+ if (group == NULL) {
+ if (dir == NULL) {
+ strcpy(group_file, _PATH_GROUP);
+ } else if (snprintf(group_file, sizeof(group_file), "%s/group",
+ group_dir) > (int)sizeof(group_file)) {
+ errno = ENAMETOOLONG;
+ return (-1);
+ }
+ } else {
+ if (strlen(group) >= sizeof(group_file)) {
+ errno = ENAMETOOLONG;
+ return (-1);
+ }
+ strcpy(group_file, group);
+ }
+ initialized = 1;
+ return (0);
+}
+
+/*
+ * Lock the group file
+ */
+int
+gr_lock(void)
+{
+ if (*group_file == '\0')
+ return (-1);
+
+ for (;;) {
+ struct stat st;
+
+ lockfd = open(group_file, O_RDONLY, 0);
+ if (lockfd < 0 || fcntl(lockfd, F_SETFD, 1) == -1)
+ err(1, "%s", group_file);
+ if (flock(lockfd, LOCK_EX|LOCK_NB) == -1) {
+ if (errno == EWOULDBLOCK) {
+ errx(1, "the group file is busy");
+ } else {
+ err(1, "could not lock the group file: ");
+ }
+ }
+ if (fstat(lockfd, &st) == -1)
+ err(1, "fstat() failed: ");
+ if (st.st_nlink != 0)
+ break;
+ close(lockfd);
+ lockfd = -1;
+ }
+ return (lockfd);
+}
+
+/*
+ * Create and open a presmuably safe temp file for editing group data
+ */
+int
+gr_tmp(int mfd)
+{
+ char buf[8192];
+ ssize_t nr;
+ const char *p;
+ int tfd;
+
+ if (*group_file == '\0')
+ return (-1);
+ if ((p = strrchr(group_file, '/')))
+ ++p;
+ else
+ p = group_file;
+ if (snprintf(tempname, sizeof(tempname), "%.*sgroup.XXXXXX",
+ (int)(p - group_file), group_file) >= (int)sizeof(tempname)) {
+ errno = ENAMETOOLONG;
+ return (-1);
+ }
+ if ((tfd = mkstemp(tempname)) == -1)
+ return (-1);
+ if (mfd != -1) {
+ while ((nr = read(mfd, buf, sizeof(buf))) > 0)
+ if (write(tfd, buf, (size_t)nr) != nr)
+ break;
+ if (nr != 0) {
+ unlink(tempname);
+ *tempname = '\0';
+ close(tfd);
+ return (-1);
+ }
+ }
+ return (tfd);
+}
+
+/*
+ * Copy the group file from one descriptor to another, replacing, deleting
+ * or adding a single record on the way.
+ */
+int
+gr_copy(int ffd, int tfd, const struct group *gr, struct group *old_gr)
+{
+ char buf[8192], *end, *line, *p, *q, *r, t;
+ struct group *fgr;
+ const struct group *sgr;
+ size_t len;
+ int eof, readlen;
+
+ sgr = gr;
+ if (gr == NULL) {
+ line = NULL;
+ if (old_gr == NULL)
+ return (-1);
+ sgr = old_gr;
+ } else if ((line = gr_make(gr)) == NULL)
+ return (-1);
+
+ eof = 0;
+ len = 0;
+ p = q = end = buf;
+ for (;;) {
+ /* find the end of the current line */
+ for (p = q; q < end && *q != '\0'; ++q)
+ if (*q == '\n')
+ break;
+
+ /* if we don't have a complete line, fill up the buffer */
+ if (q >= end) {
+ if (eof)
+ break;
+ if ((size_t)(q - p) >= sizeof(buf)) {
+ warnx("group line too long");
+ errno = EINVAL; /* hack */
+ goto err;
+ }
+ if (p < end) {
+ q = memmove(buf, p, end -p);
+ end -= p - buf;
+ } else {
+ p = q = end = buf;
+ }
+ readlen = read(ffd, end, sizeof(buf) - (end -buf));
+ if (readlen == -1)
+ goto err;
+ else
+ len = (size_t)readlen;
+ if (len == 0 && p == buf)
+ break;
+ end += len;
+ len = end - buf;
+ if (len < (ssize_t)sizeof(buf)) {
+ eof = 1;
+ if (len > 0 && buf[len -1] != '\n')
+ ++len, *end++ = '\n';
+ }
+ continue;
+ }
+
+ /* is it a blank line or a comment? */
+ for (r = p; r < q && isspace(*r); ++r)
+ /* nothing */;
+ if (r == q || *r == '#') {
+ /* yep */
+ if (write(tfd, p, q -p + 1) != q - p + 1)
+ goto err;
+ ++q;
+ continue;
+ }
+
+ /* is it the one we're looking for? */
+
+ t = *q;
+ *q = '\0';
+
+ fgr = gr_scan(r);
+
+ /* fgr is either a struct group for the current line,
+ * or NULL if the line is malformed.
+ */
+
+ *q = t;
+ if (fgr == NULL || fgr->gr_gid != sgr->gr_gid) {
+ /* nope */
+ if (fgr != NULL)
+ free(fgr);
+ if (write(tfd, p, q - p + 1) != q - p + 1)
+ goto err;
+ ++q;
+ continue;
+ }
+ if (old_gr && !gr_equal(fgr, old_gr)) {
+ warnx("entry inconsistent");
+ free(fgr);
+ errno = EINVAL; /* hack */
+ goto err;
+ }
+ free(fgr);
+
+ /* it is, replace or remove it */
+ if (line != NULL) {
+ len = strlen(line);
+ if (write(tfd, line, len) != (int) len)
+ goto err;
+ } else {
+ /* when removed, avoid the \n */
+ q++;
+ }
+ /* we're done, just copy the rest over */
+ for (;;) {
+ if (write(tfd, q, end - q) != end - q)
+ goto err;
+ q = buf;
+ readlen = read(ffd, buf, sizeof(buf));
+ if (readlen == 0)
+ break;
+ else
+ len = (size_t)readlen;
+ if (readlen == -1)
+ goto err;
+ end = buf + len;
+ }
+ goto done;
+ }
+
+ /* if we got here, we didn't find the old entry */
+ if (line == NULL) {
+ errno = ENOENT;
+ goto err;
+ }
+ len = strlen(line);
+ if ((size_t)write(tfd, line, len) != len ||
+ write(tfd, "\n", 1) != 1)
+ goto err;
+ done:
+ if (line != NULL)
+ free(line);
+ return (0);
+ err:
+ if (line != NULL)
+ free(line);
+ return (-1);
+}
+
+/*
+ * Regenerate the group file
+ */
+int
+gr_mkdb(void)
+{
+ return (rename(tempname, group_file));
+}
+
+/*
+ * Clean up. Preserver errno for the caller's convenience.
+ */
+void
+gr_fini(void)
+{
+ int serrno;
+
+ if (!initialized)
+ return;
+ initialized = 0;
+ serrno = errno;
+ if (*tempname != '\0') {
+ unlink(tempname);
+ *tempname = '\0';
+ }
+ if (lockfd != -1)
+ close(lockfd);
+ errno = serrno;
+}
+
+/*
+ * Compares two struct group's.
+ */
+int
+gr_equal(const struct group *gr1, const struct group *gr2)
+{
+ int gr1_ndx;
+ int gr2_ndx;
+ bool found;
+
+ /* Check that the non-member information is the same. */
+ if (gr1->gr_name == NULL || gr2->gr_name == NULL) {
+ if (gr1->gr_name != gr2->gr_name)
+ return (false);
+ } else if (strcmp(gr1->gr_name, gr2->gr_name) != 0)
+ return (false);
+ if (gr1->gr_passwd == NULL || gr2->gr_passwd == NULL) {
+ if (gr1->gr_passwd != gr2->gr_passwd)
+ return (false);
+ } else if (strcmp(gr1->gr_passwd, gr2->gr_passwd) != 0)
+ return (false);
+ if (gr1->gr_gid != gr2->gr_gid)
+ return (false);
+
+ /* Check all members in both groups. */
+ if (gr1->gr_mem == NULL || gr2->gr_mem == NULL) {
+ if (gr1->gr_mem != gr2->gr_mem)
+ return (false);
+ } else {
+ for (found = false, gr1_ndx = 0; gr1->gr_mem[gr1_ndx] != NULL;
+ gr1_ndx++) {
+ for (gr2_ndx = 0; gr2->gr_mem[gr2_ndx] != NULL;
+ gr2_ndx++)
+ if (strcmp(gr1->gr_mem[gr1_ndx],
+ gr2->gr_mem[gr2_ndx]) == 0) {
+ found = true;
+ break;
+ }
+ if (!found)
+ return (false);
+ }
+
+ /* Check that group2 does not have more members than group1. */
+ if (gr2->gr_mem[gr1_ndx] != NULL)
+ return (false);
+ }
+
+ return (true);
+}
+
+/*
+ * Make a group line out of a struct group.
+ */
+char *
+gr_make(const struct group *gr)
+{
+ char *line;
+ size_t line_size;
+ int ndx;
+
+ /* Calculate the length of the group line. */
+ line_size = snprintf(NULL, 0, group_line_format, gr->gr_name,
+ gr->gr_passwd, (uintmax_t)gr->gr_gid) + 1;
+ if (gr->gr_mem != NULL) {
+ for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++)
+ line_size += strlen(gr->gr_mem[ndx]) + 1;
+ if (ndx > 0)
+ line_size--;
+ }
+
+ /* Create the group line and fill it. */
+ if ((line = malloc(line_size)) == NULL)
+ return (NULL);
+ snprintf(line, line_size, group_line_format, gr->gr_name, gr->gr_passwd,
+ (uintmax_t)gr->gr_gid);
+ if (gr->gr_mem != NULL)
+ for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
+ strcat(line, gr->gr_mem[ndx]);
+ if (gr->gr_mem[ndx + 1] != NULL)
+ strcat(line, ",");
+ }
+
+ return (line);
+}
+
+/*
+ * Duplicate a struct group.
+ */
+struct group *
+gr_dup(const struct group *gr)
+{
+ char *dst;
+ size_t len;
+ struct group_storage *gs;
+ int ndx;
+ int num_mem;
+
+ /* Calculate size of the group. */
+ len = sizeof(*gs);
+ if (gr->gr_name != NULL)
+ len += strlen(gr->gr_name) + 1;
+ if (gr->gr_passwd != NULL)
+ len += strlen(gr->gr_passwd) + 1;
+ if (gr->gr_mem != NULL) {
+ for (num_mem = 0; gr->gr_mem[num_mem] != NULL; num_mem++)
+ len += strlen(gr->gr_mem[num_mem]) + 1;
+ len += (num_mem + 1) * sizeof(*gr->gr_mem);
+ } else
+ num_mem = -1;
+
+ /* Create new group and copy old group into it. */
+ if ((gs = calloc(1, len)) == NULL)
+ return (NULL);
+ dst = (char *)&gs->members[num_mem + 1];
+ if (gr->gr_name != NULL) {
+ gs->gr.gr_name = dst;
+ dst = stpcpy(gs->gr.gr_name, gr->gr_name) + 1;
+ }
+ if (gr->gr_passwd != NULL) {
+ gs->gr.gr_passwd = dst;
+ dst = stpcpy(gs->gr.gr_passwd, gr->gr_passwd) + 1;
+ }
+ gs->gr.gr_gid = gr->gr_gid;
+ if (gr->gr_mem != NULL) {
+ gs->gr.gr_mem = gs->members;
+ for (ndx = 0; ndx < num_mem; ndx++) {
+ gs->gr.gr_mem[ndx] = dst;
+ dst = stpcpy(gs->gr.gr_mem[ndx], gr->gr_mem[ndx]) + 1;
+ }
+ gs->gr.gr_mem[ndx] = NULL;
+ }
+
+ return (&gs->gr);
+}
+
+/*
+ * Scan a line and place it into a group structure.
+ */
+static bool
+__gr_scan(char *line, struct group *gr)
+{
+ char *loc;
+ int ndx;
+
+ /* Assign non-member information to structure. */
+ gr->gr_name = line;
+ if ((loc = strchr(line, ':')) == NULL)
+ return (false);
+ *loc = '\0';
+ gr->gr_passwd = loc + 1;
+ if (*gr->gr_passwd == ':')
+ *gr->gr_passwd = '\0';
+ else {
+ if ((loc = strchr(loc + 1, ':')) == NULL)
+ return (false);
+ *loc = '\0';
+ }
+ if (sscanf(loc + 1, "%u", &gr->gr_gid) != 1)
+ return (false);
+
+ /* Assign member information to structure. */
+ if ((loc = strchr(loc + 1, ':')) == NULL)
+ return (false);
+ line = loc + 1;
+ gr->gr_mem = NULL;
+ ndx = 0;
+ do {
+ gr->gr_mem = reallocf(gr->gr_mem, sizeof(*gr->gr_mem) *
+ (ndx + 1));
+ if (gr->gr_mem == NULL)
+ return (false);
+
+ /* Skip locations without members (i.e., empty string). */
+ do {
+ gr->gr_mem[ndx] = strsep(&line, ",");
+ } while (gr->gr_mem[ndx] != NULL && *gr->gr_mem[ndx] == '\0');
+ } while (gr->gr_mem[ndx++] != NULL);
+
+ return (true);
+}
+
+/*
+ * Create a struct group from a line.
+ */
+struct group *
+gr_scan(const char *line)
+{
+ struct group gr;
+ char *line_copy;
+ struct group *new_gr;
+
+ if ((line_copy = strdup(line)) == NULL)
+ return (NULL);
+ if (!__gr_scan(line_copy, &gr)) {
+ free(line_copy);
+ return (NULL);
+ }
+ new_gr = gr_dup(&gr);
+ free(line_copy);
+ if (gr.gr_mem != NULL)
+ free(gr.gr_mem);
+
+ return (new_gr);
+}
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