1 files changed, 24 insertions, 0 deletions
diff --git a/src/libnsss/nsss_grouplist_adjust.c b/src/libnsss/nsss_grouplist_adjust.c
new file mode 100644
index 0000000..fda4882
--- /dev/null
+++ b/src/libnsss/nsss_grouplist_adjust.c
@@ -0,0 +1,24 @@
+/* ISC license. */
+
+#include <string.h>
+#include <errno.h>
+#include <limits.h>
+
+#include <nsss/grp-def.h>
+#include "nsss-internal.h"
+
+int nsss_grouplist_adjust (size_t n, size_t r, gid_t gid, gid_t *gids, int *ngids, int e)
+{
+  if (r > INT_MAX) return (errno = EMSGSIZE, -1) ;
+  if (r > n) return (*ngids = (int)r, errno = ENOBUFS, -1) ;
+  for (size_t i = 0 ; i < r ; i++) if (gid == gids[i]) goto ok ;
+  r++ ;
+  if (r > INT_MAX) return (errno = EMSGSIZE, -1) ;
+  if (r > n) return (*ngids = (int)r, errno = ENOBUFS, -1) ;
+  memmove(gids + 1, gids, (r-1) * sizeof(gid_t)) ;
+  gids[0] = gid ;
+ ok:
+  *ngids = (int)r ;
+  errno = e ;
+  return (int)n ;
+}