1 files changed, 103 insertions, 0 deletions
diff --git a/libchannel/hub.c b/libchannel/hub.c
new file mode 100644
index 000000000..31ee4d4b8
--- /dev/null
+++ b/libchannel/hub.c
@@ -0,0 +1,103 @@
+/* Generic channel hub functions.
+
+   Copyright (C) 2007 Free Software Foundation, Inc.
+
+   Written by Carl Fredrik Hammar <hammy.lite@gmail.com>
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd 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.
+
+   The GNU Hurd 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., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
+
+#include <malloc.h>
+
+#include "channel.h"
+
+/* Allocate a new hub of CLASS with FLAGS set, then return it in HUB.
+   Return ENOMEM if memory for the hub couldn't be allocated.  */
+error_t
+channel_alloc_hub (const struct channel_class *class, int flags,
+		   struct channel_hub **hub)
+{
+  struct channel_hub *new_hub = malloc (sizeof (struct channel_hub));
+  if (! new_hub)
+    return ENOMEM;
+
+  new_hub->class = class;
+  new_hub->flags = flags;
+  new_hub->hook = 0;
+
+  *hub = new_hub;
+  return 0;
+}
+
+/* If not null call method clear_hub to deallocate class-specific bits of
+   HUB, then (regardless) free any generic resources used by it and
+   itself.  */
+void
+channel_free_hub (struct channel_hub *hub)
+{
+  if (hub->class->clear_hub)
+    (*hub->class->clear_hub) (hub);
+
+  free (hub);
+}
+
+/* Set the flags FLAGS in HUB.  Remove any already set flags in FLAGS, if
+   FLAGS then contain backend flags call set_hub_flags method with with
+   FLAGS or if set_hub_flags is null return EINVAL.  Lastly generic flags
+   get set.  */
+error_t
+channel_set_hub_flags (struct channel_hub *hub, int flags)
+{
+  int orig = hub->flags, new = flags & ~orig;
+  error_t err = 0;
+
+  if (new & CHANNEL_BACKEND_FLAGS)
+    {
+      if (hub->class->set_hub_flags)
+	err = (*hub->class->set_hub_flags) (hub, new);
+      else
+	err = EINVAL;
+    }
+
+  if (! err)
+    hub->flags |= (new & ~CHANNEL_BACKEND_FLAGS);
+
+  return err;
+}
+
+/* Clear the flags FLAGS in HUB.  Remove any already cleared flags in
+   FLAGS, if FLAGS then contain backend flags call clear_hub_flags method
+   with with FLAGS or if clear_hub_flags is null return EINVAL.  Lastly
+   generic flags get clear.  */
+error_t
+channel_clear_hub_flags (struct channel_hub *hub, int flags)
+{
+  int orig = hub->flags, kill = flags & orig;
+  error_t err = 0;
+
+  if (kill & CHANNEL_BACKEND_FLAGS)
+    {
+      if (hub->class->clear_hub_flags)
+	err = (*hub->class->clear_hub_flags) (hub, kill);
+      else
+	err = EINVAL;
+    }
+
+  if (! err)
+    hub->flags &= ~(kill & ~CHANNEL_BACKEND_FLAGS);
+
+  return err;
+}