batman-adv: Receive fragmented packets and merge

Fragments arriving at their destination are buffered for later merge.
Merged packets are passed to the main receive function as had they never
been fragmented.

Fragments are forwarded without merging if the MTU of the outgoing
interface is smaller than the size of the merged packet.

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/net/batman-adv/fragmentation.h b/net/batman-adv/fragmentation.h
new file mode 100644
index 000000000000..883a6f46005e
--- /dev/null
+++ b/net/batman-adv/fragmentation.h
@@ -0,0 +1,47 @@
+/* Copyright (C) 2013 B.A.T.M.A.N. contributors:
+ *
+ * Martin Hundebøll <martin@hundeboll.net>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ */
+
+#ifndef _NET_BATMAN_ADV_FRAGMENTATION_H_
+#define _NET_BATMAN_ADV_FRAGMENTATION_H_
+
+void batadv_frag_purge_orig(struct batadv_orig_node *orig,
+			    bool (*check_cb)(struct batadv_frag_table_entry *));
+bool batadv_frag_skb_fwd(struct sk_buff *skb,
+			 struct batadv_hard_iface *recv_if,
+			 struct batadv_orig_node *orig_node_src);
+bool batadv_frag_skb_buffer(struct sk_buff **skb,
+			    struct batadv_orig_node *orig_node);
+
+/**
+ * batadv_frag_check_entry - check if a list of fragments has timed out
+ * @frags_entry: table entry to check
+ *
+ * Returns true if the frags entry has timed out, false otherwise.
+ */
+static inline bool
+batadv_frag_check_entry(struct batadv_frag_table_entry *frags_entry)
+{
+	if (!hlist_empty(&frags_entry->head) &&
+	    batadv_has_timed_out(frags_entry->timestamp, BATADV_FRAG_TIMEOUT))
+		return true;
+	else
+		return false;
+}
+
+#endif /* _NET_BATMAN_ADV_FRAGMENTATION_H_ */