X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fgetgroups.c;h=e2bb68eff290529db5e987abe80574b2912c870f;hb=bc835ff38e3fb6a3d0f5ed6eed0981dde8884124;hp=207a44189843e40f1b7c809157216e1af96dfd97;hpb=08e6b4c6ba690adba619a3c1695bc312d3e98136;p=gnulib.git

diff --git a/lib/getgroups.c b/lib/getgroups.c
index 207a44189..e2bb68eff 100644
--- a/lib/getgroups.c
+++ b/lib/getgroups.c
@@ -20,30 +20,76 @@
 
 #include <config.h>
 
-#undef getgroups
+#include <unistd.h>
 
-#include <stdio.h>
-#include <sys/types.h>
 #include <errno.h>
 #include <stdlib.h>
-#include <unistd.h>
+#include <stdint.h>
+
+#if !HAVE_GETGROUPS
+
+/* Provide a stub that fails with ENOSYS, since there is no group
+   information available on mingw.  */
+int
+getgroups (int n _UNUSED_PARAMETER_, GETGROUPS_T *groups _UNUSED_PARAMETER_)
+{
+  errno = ENOSYS;
+  return -1;
+}
+
+#else /* HAVE_GETGROUPS */
 
-#include "xalloc.h"
+# undef getgroups
+# ifndef GETGROUPS_ZERO_BUG
+#  define GETGROUPS_ZERO_BUG 0
+# endif
 
-/* On at least Ultrix 4.3 and NextStep 3.2, getgroups (0, 0) always fails.
-   On other systems, it returns the number of supplemental groups for the
-   process.  This function handles that special case and lets the system-
-   provided function handle all others. */
+/* On at least Ultrix 4.3 and NextStep 3.2, getgroups (0, NULL) always
+   fails.  On other systems, it returns the number of supplemental
+   groups for the process.  This function handles that special case
+   and lets the system-provided function handle all others.  However,
+   it can fail with ENOMEM if memory is tight.  It is unspecified
+   whether the effective group id is included in the list.  */
 
 int
-rpl_getgroups (int n, GETGROUPS_T *group)
+rpl_getgroups (int n, gid_t *group)
 {
   int n_groups;
   GETGROUPS_T *gbuf;
   int saved_errno;
 
-  if (n != 0)
-    return getgroups (n, group);
+  if (n < 0)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
+  if (n != 0 || !GETGROUPS_ZERO_BUG)
+    {
+      int result;
+      if (sizeof *group == sizeof *gbuf)
+        return getgroups (n, (GETGROUPS_T *) group);
+
+      if (SIZE_MAX / sizeof *gbuf <= n)
+        {
+          errno = ENOMEM;
+          return -1;
+        }
+      gbuf = malloc (n * sizeof *gbuf);
+      if (!gbuf)
+        return -1;
+      result = getgroups (n, gbuf);
+      if (0 <= result)
+        {
+          n = result;
+          while (n--)
+            group[n] = gbuf[n];
+        }
+      saved_errno = errno;
+      free (gbuf);
+      errno == saved_errno;
+      return result;
+    }
 
   n = 20;
   while (1)
@@ -51,7 +97,9 @@ rpl_getgroups (int n, GETGROUPS_T *group)
       /* No need to worry about address arithmetic overflow here,
          since the ancient systems that we're running on have low
          limits on the number of secondary groups.  */
-      gbuf = xmalloc (n * sizeof *gbuf);
+      gbuf = malloc (n * sizeof *gbuf);
+      if (!gbuf)
+        return -1;
       n_groups = getgroups (n, gbuf);
       if (n_groups == -1 ? errno != EINVAL : n_groups < n)
         break;
@@ -65,3 +113,5 @@ rpl_getgroups (int n, GETGROUPS_T *group)
 
   return n_groups;
 }
+
+#endif /* HAVE_GETGROUPS */