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authorDenys Vlasenko <vda.linux@googlemail.com>2011-06-22 14:42:36 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2011-06-22 14:42:36 (GMT)
commit52f4fe9db6cedfba332ee0923182f5b2e9d9673b (patch)
treea150597a766f5761fef33b7af35a2d4e4b8a4978
parentd5ac9c88a7f620f6b775e404b145017827a10480 (diff)
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id: correct getgroups usage
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--coreutils/id.c31
1 files changed, 15 insertions, 16 deletions
diff --git a/coreutils/id.c b/coreutils/id.c
index bb950f9..399d25e 100644
--- a/coreutils/id.c
+++ b/coreutils/id.c
@@ -117,7 +117,7 @@ static int print_user(uid_t id, const char *prefix)
/* On error set *n < 0 and return >= 0
* If *n is too small, update it and return < 0
- * (ok to trash groups[] in both cases)
+ * (ok to trash groups[] in both cases)
* Otherwise fill in groups[] and return >= 0
*/
static int get_groups(const char *username, gid_t rgid, gid_t *groups, int *n)
@@ -131,20 +131,19 @@ static int get_groups(const char *username, gid_t rgid, gid_t *groups, int *n)
m = getgrouplist(username, rgid, groups, n);
/* I guess *n < 0 might indicate error. Anyway,
* malloc'ing -1 bytes won't be good, so: */
- //if (*n < 0)
- // return 0;
- //return m;
- //commented out here, happens below anyway
- } else {
- /* On error -1 is returned, which ends up in *n */
- int nn = getgroups(*n, groups);
- /* 0: nn <= *n, groups[] was big enough; -1 otherwise */
- m = - (nn > *n);
- *n = nn;
+ if (*n < 0)
+ return 0;
+ return m;
}
- if (*n < 0)
- return 0; /* error, don't return < 0! */
- return m;
+
+ *n = getgroups(*n, groups);
+ if (*n >= 0)
+ return *n;
+ /* Error */
+ if (errno == EINVAL) /* *n is too small? */
+ *n = getgroups(0, groups); /* get needed *n */
+ /* if *n >= 0, return -1 (got new *n), else return 0 (error): */
+ return -(*n >= 0);
}
int id_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
@@ -214,11 +213,11 @@ int id_main(int argc UNUSED_PARAM, char **argv)
/* We are supplying largish buffer, trying
* to not run get_groups() twice. That might be slow
* ("user database in remote SQL server" case) */
- groups = xmalloc(64 * sizeof(gid_t));
+ groups = xmalloc(64 * sizeof(groups[0]));
n = 64;
if (get_groups(username, rgid, groups, &n) < 0) {
/* Need bigger buffer after all */
- groups = xrealloc(groups, n * sizeof(gid_t));
+ groups = xrealloc(groups, n * sizeof(groups[0]));
get_groups(username, rgid, groups, &n);
}
if (n > 0) {