Initial checkin

1 files changed, 97 insertions, 0 deletions

diff --git a/libshouldbeinlibc/ugids-posix.c b/libshouldbeinlibc/ugids-posix.c
new file mode 100644
index 00000000..b8ed8e74
--- /dev/null
+++ b/libshouldbeinlibc/ugids-posix.c
@@ -0,0 +1,97 @@
+/* Set posix-compatible ugids
+
+   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 "ugids.h"
+
+/* Install UID into UGIDS as the main user, making sure that the posix
+   `real' and `saved' uid slots are filled in, and similarly add all
+   groups to which UID belongs.  */
+error_t
+ugids_set_posix_user (struct ugids *ugids, uid_t uid)
+{
+  error_t err;
+  struct idvec imp_gids = IDVEC_INIT;
+  uid_t uids_ids[] = { uid };
+  struct idvec uids = { uids_ids, 1 };
+
+  err = idvec_merge_implied_gids (&imp_gids, &uids);
+  if (! err)
+    {
+      error_t update_real (struct idvec *avail_ids, uid_t id)
+	{
+	  if (avail_ids->num == 0
+	      || !idvec_tail_contains (avail_ids, 1, avail_ids->ids[0]))
+	    return idvec_insert (avail_ids, 0, id);
+	  else
+	    avail_ids->ids[0] = id;
+	  return 0;
+	}
+
+      /* Try to add UID.  */
+      err = idvec_insert_only (&ugids->eff_uids, 0, uid); /* Effective */
+      if (! err)
+	err = update_real (&ugids->avail_uids, uid); /* Real */
+      if (! err)
+	err = idvec_insert_only (&ugids->avail_uids, 1, uid); /* Saved */
+	
+      if (!err && imp_gids.num > 0)
+	/* Now do the gids.  */
+	{
+	  /* The main gid associated with UID (usually from /etc/passwd).  */
+	  gid_t gid = imp_gids.ids[0];
+	  /* True if GID was already an available gid.  */
+	  int gid_was_avail = idvec_contains (&ugids->avail_gids, gid);
+
+	  /* Update the implied sets for the gids: they're implied unless
+	     they were present as non-implied gids before.  Here we
+	     remove existing effective gids from the IMP_GIDS before we
+	     added it to the implied sets -- if some of those gids were
+	     actually implied, they'll already be present in the implied
+	     set. */
+	  idvec_subtract (&imp_gids, &ugids->eff_gids);
+
+	  /* Now add GID, as effective, real, and saved gids.  */
+	  if (! err)	/* Effective */
+	    err = idvec_insert_only (&ugids->eff_gids, 0, gid);
+	  if (! err)	/* Real */
+	    err = update_real (&ugids->avail_gids, gid);
+	  if (! err)	/* Saved */
+	    err = idvec_insert_only (&ugids->avail_gids, 1, gid);
+
+	  /* Mark GID as implied in the available gids unless it was already
+	     present (in which case its implied status is already settled).  */
+	  if (!err && !gid_was_avail)
+	    err = idvec_add (&ugids->imp_avail_gids, gid);
+
+	  /* Add the other implied gids to the end of the effective gids.  */
+	  if (! err)
+	    err = idvec_merge (&ugids->eff_gids, &imp_gids);
+	  /* And make them implied.  */
+	  if (! err)
+	    err = idvec_merge (&ugids->imp_eff_gids, &imp_gids);
+	}
+    }
+
+  idvec_fini (&imp_gids);
+
+  return err;
+}