2002-04-30 Marcus Brinkmann <marcus@gnu.org>

       * priv.h: Add OPT_NO_INHERIT_DIR_GROUP and OPT_INHERIT_DIR_GROUP.
       (_diskfs_no_inherit_dir_group): New declaration.
       * node-create.c (_diskfs_no_inherit_dir_group): New variable.
       (diskfs_create_node): Implement SysV group behaviour.
       * opts-common.c (diskfs_common_options): Add
       --no-inherit-dir-group (--nogrpdir, --sysvgroups) and
       --inherit-dir-group (--grpdir, --bsdgroups).
       * opts-append-std.c (diskfs_append_std_options): Add
       --no-inherit-dir-group if set.
       * opts-std-startup.c (parse_startup_opt): Add toggle for
       _diskfs_no_inherit_dir_group.
       * opts-std-runtime.c (struct parse_hook): Add noinheritdirgroup.
       (set_opts): Handle H->noinheritdirgroup.
       (parse_opt): Initialize H->noinheritdirgroup.  Handle
       OPT_NO_INHERIT_DIR_GROUP and OPT_INHERIT_DIR_GROUP.

1 files changed, 39 insertions, 3 deletions

diff --git a/libdiskfs/node-create.c b/libdiskfs/node-create.c
index 7cbdade1..4a7d108d 100644
--- a/libdiskfs/node-create.c
+++ b/libdiskfs/node-create.c
@@ -17,6 +17,11 @@
 
 #include "priv.h"
 
+/* This enables SysV style group behaviour.  New nodes inherit the GID
+   of the user creating them unless the SGID bit is set of the parent
+   directory.  */
+int _diskfs_no_inherit_dir_group;
+
 /* Create a new node. Give it MODE; if that includes IFDIR, also
    initialize `.' and `..' in the new directory.  Return the node in NPP.
    CRED identifies the user responsible for the call.  If NAME is nonzero,
@@ -70,9 +75,40 @@ diskfs_create_node (struct node *dir,
   if (np->author_tracks_uid)
     np->dn_stat.st_author = newuid;
 
-  newgid = dir->dn_stat.st_gid;
-  if (!idvec_contains (cred->user->gids, newgid))
-    mode &= ~S_ISGID;
+  if (!_diskfs_no_inherit_dir_group)
+    {
+      newgid = dir->dn_stat.st_gid;
+      if (!idvec_contains (cred->user->gids, newgid))
+       mode &= ~S_ISGID;
+    }
+  else
+    {
+      if (dir->dn_stat.st_mode & S_ISGID)
+       {
+         /* If the parent dir has the sgid bit set, inherit its gid.
+            If the new node is a directory, also inherit the sgid bit
+            set.  */
+         newgid = dir->dn_stat.st_gid;
+         if (S_ISDIR (mode))
+           mode |= S_ISGID;
+         else
+           {
+             if (!idvec_contains (cred->user->gids, newgid))
+               mode &= ~S_ISGID;
+           }
+       }
+      else
+       {
+         if (cred->user->gids->num)
+           newgid = cred->user->gids->ids[0];
+         else
+           {
+             newgid = dir->dn_stat.st_gid;
+             mode &= ~S_ISGID;
+           }
+       }
+    }
+
   err = diskfs_validate_group_change (np, newgid);
   if (err)
     goto change_err;