batman-adv: network coding - code and transmit packets if possible

Before adding forward-skbs to the coding buffer, the buffer is searched
for a potential coding opportunity. If one is found, the two packets are
network coded and transmitted right away. If not, the forward-skb is
added to the buffer.

Network coded packets are transmitted with information about the two
receivers and the two coded packets. The first receiver is given by the
MAC header, while the second is given in the payload/bat-header. The
second receiver uses promiscuous mode to receive the packet and check
the second destination.

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 43caf7f493c1..42d743850ec2 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -275,6 +275,10 @@ struct batadv_bcast_duplist_entry {
  * @BATADV_CNT_DAT_PUT_RX: received dht PUT traffic packet counter
  * @BATADV_CNT_DAT_CACHED_REPLY_TX: transmitted dat cache reply traffic packet
  *  counter
+ * @BATADV_CNT_NC_CODE: transmitted nc-combined traffic packet counter
+ * @BATADV_CNT_NC_CODE_BYTES: transmitted nc-combined traffic bytes counter
+ * @BATADV_CNT_NC_RECODE: transmitted nc-recombined traffic packet counter
+ * @BATADV_CNT_NC_RECODE_BYTES: transmitted nc-recombined traffic bytes counter
  * @BATADV_CNT_NUM: number of traffic counters
  */
 enum batadv_counters {
@@ -302,6 +306,12 @@ enum batadv_counters {
 	BATADV_CNT_DAT_PUT_RX,
 	BATADV_CNT_DAT_CACHED_REPLY_TX,
 #endif
+#ifdef CONFIG_BATMAN_ADV_NC
+	BATADV_CNT_NC_CODE,
+	BATADV_CNT_NC_CODE_BYTES,
+	BATADV_CNT_NC_RECODE,
+	BATADV_CNT_NC_RECODE_BYTES,
+#endif
 	BATADV_CNT_NUM,
 };
 
@@ -797,6 +807,16 @@ struct batadv_nc_packet {
 };
 
 /**
+ * batadv_skb_cb - control buffer structure used to store private data relevant
+ *  to batman-adv in the skb->cb buffer in skbs.
+ * @decoded: Marks a skb as decoded, which is checked when searching for coding
+ *  opportunities in network-coding.c
+ */
+struct batadv_skb_cb {
+	bool decoded;
+};
+
+/**
  * struct batadv_forw_packet - structure for bcast packets to be sent/forwarded
  * @list: list node for batadv_socket_client::queue_list
  * @send_time: execution time for delayed_work (packet sending)