1 files changed, 123 insertions, 0 deletions
diff --git a/libshouldbeinlibc/idvec-impgids.c b/libshouldbeinlibc/idvec-impgids.c
new file mode 100644
index 00000000..62417e12
--- /dev/null
+++ b/libshouldbeinlibc/idvec-impgids.c
@@ -0,0 +1,123 @@
+/* Add gids implied by a user
+
+   Copyright (C) 1997 Free Software Foundation, Inc.
+
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include <stdlib.h>
+#include <errno.h>
+#include <idvec.h>
+#include <pwd.h>
+#include <grp.h>
+
+#define NUM_STATIC_GIDS 100	/* Initial size of static gid array.  */
+
+/* The set of gids implied by a uid.  */
+struct uid_implies
+{
+  uid_t uid;			/* this uid... */
+  struct idvec *implies;	/* implies these gids.  */
+  struct uid_implies *next;
+};
+
+/* Cache of previously calculated results for add_implied_gids.  */
+static struct uid_implies *uid_implies_cache = 0;
+
+/* Add to IMPLIED_GIDS those group ids implied by the user UID.  */
+static error_t
+_merge_implied_gids (struct idvec *implied_gids, uid_t uid)
+{
+  struct uid_implies *ui;
+
+  for (ui = uid_implies_cache; ui; ui = ui->next)
+    if (ui->uid == uid)
+      return idvec_merge (implied_gids, ui->implies);
+
+  {
+    error_t err = 0;
+    struct passwd *pw = getpwuid (uid);
+
+    if (! pw)
+      err = EINVAL;
+    else
+      {
+	struct idvec *cache = make_idvec ();
+#if 0  /* Glibc doesn't have getgrouplist yet.  */
+	gid_t _gids[NUM_STATIC_GIDS], *gids = _gids;
+	size_t maxgids = NUM_STATIC_GIDS;
+	size_t ngids =
+	  getgrouplist (pw->pw_name, pw->pw_gid, gids, &maxgids);
+
+	if (ngids == -1)
+	  {
+	    gids = malloc (maxgids * sizeof (gid_t));
+	    if (! gids)
+	      err = ENOMEM;
+	    else
+	      ngids = getgrouplist (pw->pw_name, pw->pw_gid, gids, &maxgids);
+	  }
+
+	if (! cache)
+	  err = ENOMEM;
+
+	if (! err)
+	  {
+	    err = idvec_merge_ids (cache, gids, ngids);
+	    if (gids != _gids)
+	      free (gids);
+	  }
+#else
+	if (! cache)
+	  err = ENOMEM;
+	else
+	  err = idvec_add_new (cache, pw->pw_gid);
+#endif
+
+	if (! err)
+	  {
+	    idvec_merge (implied_gids, cache);
+	    ui = malloc (sizeof (struct uid_implies));
+	    if (ui)
+	      {
+		ui->uid = uid;
+		ui->implies = cache;
+		ui->next = uid_implies_cache;
+		uid_implies_cache = ui;
+	      }
+	    else
+	      idvec_free (cache);
+	  }
+      }
+
+    return err;
+  }
+}
+
+/* Add to GIDS those group ids implied by the users in UIDS.  */
+error_t
+idvec_merge_implied_gids (struct idvec *gids, const struct idvec *uids)
+{
+  int i;
+  error_t err = 0;
+  for (i = 0; i < uids->num; i++)
+    {
+      error_t this_err = _merge_implied_gids (gids, uids->ids[i]);
+      if (this_err && !err)
+	err = this_err;
+    }
+  return err;
+}