The following commit has been merged in the master branch:
commit 3c12de9a5c756b23fe7c9ab332474ece1568914c
Author: Martin Hundebøll <martin(a)hundeboll.net>
Date: Fri Jan 25 11:12:41 2013 +0100
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(a)hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek(a)yahoo.de>
Signed-off-by: Antonio Quartulli <ordex(a)autistici.org>
diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h
index 8a10619..0afd4ee 100644
--- a/net/batman-adv/main.h
+++ b/net/batman-adv/main.h
@@ -302,4 +302,10 @@ static inline uint64_t batadv_sum_counter(struct batadv_priv *bat_priv,
return sum;
}
+/* Define a macro to reach the control buffer of the skb. The members of the
+ * control buffer are defined in struct batadv_skb_cb in types.h.
+ * The macro is inspired by the similar macro TCP_SKB_CB() in tcp.h.
+ */
+#define BATADV_SKB_CB(__skb) ((struct batadv_skb_cb *)&((__skb)->cb[0]))
+
#endif /* _NET_BATMAN_ADV_MAIN_H_ */
diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c
index 2c38c54..fce2846 100644
--- a/net/batman-adv/network-coding.c
+++ b/net/batman-adv/network-coding.c
@@ -798,6 +798,403 @@ static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv,
}
/**
+ * batadv_nc_random_weight_tq - scale the receivers TQ-value to avoid unfair
+ * selection of a receiver with slightly lower TQ than the other
+ * @tq: to be weighted tq value
+ */
+static uint8_t batadv_nc_random_weight_tq(uint8_t tq)
+{
+ uint8_t rand_val, rand_tq;
+
+ get_random_bytes(&rand_val, sizeof(rand_val));
+
+ /* randomize the estimated packet loss (max TQ - estimated TQ) */
+ rand_tq = rand_val * (BATADV_TQ_MAX_VALUE - tq);
+
+ /* normalize the randomized packet loss */
+ rand_tq /= BATADV_TQ_MAX_VALUE;
+
+ /* convert to (randomized) estimated tq again */
+ return BATADV_TQ_MAX_VALUE - rand_tq;
+}
+
+/**
+ * batadv_nc_memxor - XOR destination with source
+ * @dst: byte array to XOR into
+ * @src: byte array to XOR from
+ * @len: length of destination array
+ */
+static void batadv_nc_memxor(char *dst, const char *src, unsigned int len)
+{
+ unsigned int i;
+
+ for (i = 0; i < len; ++i)
+ dst[i] ^= src[i];
+}
+
+/**
+ * batadv_nc_code_packets - code a received unicast_packet with an nc packet
+ * into a coded_packet and send it
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: data skb to forward
+ * @ethhdr: pointer to the ethernet header inside the skb
+ * @nc_packet: structure containing the packet to the skb can be coded with
+ * @neigh_node: next hop to forward packet to
+ *
+ * Returns true if both packets are consumed, false otherwise.
+ */
+static bool batadv_nc_code_packets(struct batadv_priv *bat_priv,
+ struct sk_buff *skb,
+ struct ethhdr *ethhdr,
+ struct batadv_nc_packet *nc_packet,
+ struct batadv_neigh_node *neigh_node)
+{
+ uint8_t tq_weighted_neigh, tq_weighted_coding;
+ struct sk_buff *skb_dest, *skb_src;
+ struct batadv_unicast_packet *packet1;
+ struct batadv_unicast_packet *packet2;
+ struct batadv_coded_packet *coded_packet;
+ struct batadv_neigh_node *neigh_tmp, *router_neigh;
+ struct batadv_neigh_node *router_coding = NULL;
+ uint8_t *first_source, *first_dest, *second_source, *second_dest;
+ __be32 packet_id1, packet_id2;
+ size_t count;
+ bool res = false;
+ int coding_len;
+ int unicast_size = sizeof(*packet1);
+ int coded_size = sizeof(*coded_packet);
+ int header_add = coded_size - unicast_size;
+
+ router_neigh = batadv_orig_node_get_router(neigh_node->orig_node);
+ if (!router_neigh)
+ goto out;
+
+ neigh_tmp = nc_packet->neigh_node;
+ router_coding = batadv_orig_node_get_router(neigh_tmp->orig_node);
+ if (!router_coding)
+ goto out;
+
+ tq_weighted_neigh = batadv_nc_random_weight_tq(router_neigh->tq_avg);
+ tq_weighted_coding = batadv_nc_random_weight_tq(router_coding->tq_avg);
+
+ /* Select one destination for the MAC-header dst-field based on
+ * weighted TQ-values.
+ */
+ if (tq_weighted_neigh >= tq_weighted_coding) {
+ /* Destination from nc_packet is selected for MAC-header */
+ first_dest = nc_packet->nc_path->next_hop;
+ first_source = nc_packet->nc_path->prev_hop;
+ second_dest = neigh_node->addr;
+ second_source = ethhdr->h_source;
+ packet1 = (struct batadv_unicast_packet *)nc_packet->skb->data;
+ packet2 = (struct batadv_unicast_packet *)skb->data;
+ packet_id1 = nc_packet->packet_id;
+ packet_id2 = batadv_skb_crc32(skb,
+ skb->data + sizeof(*packet2));
+ } else {
+ /* Destination for skb is selected for MAC-header */
+ first_dest = neigh_node->addr;
+ first_source = ethhdr->h_source;
+ second_dest = nc_packet->nc_path->next_hop;
+ second_source = nc_packet->nc_path->prev_hop;
+ packet1 = (struct batadv_unicast_packet *)skb->data;
+ packet2 = (struct batadv_unicast_packet *)nc_packet->skb->data;
+ packet_id1 = batadv_skb_crc32(skb,
+ skb->data + sizeof(*packet1));
+ packet_id2 = nc_packet->packet_id;
+ }
+
+ /* Instead of zero padding the smallest data buffer, we
+ * code into the largest.
+ */
+ if (skb->len <= nc_packet->skb->len) {
+ skb_dest = nc_packet->skb;
+ skb_src = skb;
+ } else {
+ skb_dest = skb;
+ skb_src = nc_packet->skb;
+ }
+
+ /* coding_len is used when decoding the packet shorter packet */
+ coding_len = skb_src->len - unicast_size;
+
+ if (skb_linearize(skb_dest) < 0 || skb_linearize(skb_src) < 0)
+ goto out;
+
+ skb_push(skb_dest, header_add);
+
+ coded_packet = (struct batadv_coded_packet *)skb_dest->data;
+ skb_reset_mac_header(skb_dest);
+
+ coded_packet->header.packet_type = BATADV_CODED;
+ coded_packet->header.version = BATADV_COMPAT_VERSION;
+ coded_packet->header.ttl = packet1->header.ttl;
+
+ /* Info about first unicast packet */
+ memcpy(coded_packet->first_source, first_source, ETH_ALEN);
+ memcpy(coded_packet->first_orig_dest, packet1->dest, ETH_ALEN);
+ coded_packet->first_crc = packet_id1;
+ coded_packet->first_ttvn = packet1->ttvn;
+
+ /* Info about second unicast packet */
+ memcpy(coded_packet->second_dest, second_dest, ETH_ALEN);
+ memcpy(coded_packet->second_source, second_source, ETH_ALEN);
+ memcpy(coded_packet->second_orig_dest, packet2->dest, ETH_ALEN);
+ coded_packet->second_crc = packet_id2;
+ coded_packet->second_ttl = packet2->header.ttl;
+ coded_packet->second_ttvn = packet2->ttvn;
+ coded_packet->coded_len = htons(coding_len);
+
+ /* This is where the magic happens: Code skb_src into skb_dest */
+ batadv_nc_memxor(skb_dest->data + coded_size,
+ skb_src->data + unicast_size, coding_len);
+
+ /* Update counters accordingly */
+ if (BATADV_SKB_CB(skb_src)->decoded &&
+ BATADV_SKB_CB(skb_dest)->decoded) {
+ /* Both packets are recoded */
+ count = skb_src->len + ETH_HLEN;
+ count += skb_dest->len + ETH_HLEN;
+ batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE, 2);
+ batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES, count);
+ } else if (!BATADV_SKB_CB(skb_src)->decoded &&
+ !BATADV_SKB_CB(skb_dest)->decoded) {
+ /* Both packets are newly coded */
+ count = skb_src->len + ETH_HLEN;
+ count += skb_dest->len + ETH_HLEN;
+ batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE, 2);
+ batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES, count);
+ } else if (BATADV_SKB_CB(skb_src)->decoded &&
+ !BATADV_SKB_CB(skb_dest)->decoded) {
+ /* skb_src recoded and skb_dest is newly coded */
+ batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE);
+ batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES,
+ skb_src->len + ETH_HLEN);
+ batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE);
+ batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES,
+ skb_dest->len + ETH_HLEN);
+ } else if (!BATADV_SKB_CB(skb_src)->decoded &&
+ BATADV_SKB_CB(skb_dest)->decoded) {
+ /* skb_src is newly coded and skb_dest is recoded */
+ batadv_inc_counter(bat_priv, BATADV_CNT_NC_CODE);
+ batadv_add_counter(bat_priv, BATADV_CNT_NC_CODE_BYTES,
+ skb_src->len + ETH_HLEN);
+ batadv_inc_counter(bat_priv, BATADV_CNT_NC_RECODE);
+ batadv_add_counter(bat_priv, BATADV_CNT_NC_RECODE_BYTES,
+ skb_dest->len + ETH_HLEN);
+ }
+
+ /* skb_src is now coded into skb_dest, so free it */
+ kfree_skb(skb_src);
+
+ /* avoid duplicate free of skb from nc_packet */
+ nc_packet->skb = NULL;
+ batadv_nc_packet_free(nc_packet);
+
+ /* Send the coded packet and return true */
+ batadv_send_skb_packet(skb_dest, neigh_node->if_incoming, first_dest);
+ res = true;
+out:
+ if (router_neigh)
+ batadv_neigh_node_free_ref(router_neigh);
+ if (router_coding)
+ batadv_neigh_node_free_ref(router_coding);
+ return res;
+}
+
+/**
+ * batadv_nc_skb_coding_possible - true if a decoded skb is available at dst.
+ * @skb: data skb to forward
+ * @dst: destination mac address of the other skb to code with
+ * @src: source mac address of skb
+ *
+ * Whenever we network code a packet we have to check whether we received it in
+ * a network coded form. If so, we may not be able to use it for coding because
+ * some neighbors may also have received (overheard) the packet in the network
+ * coded form without being able to decode it. It is hard to know which of the
+ * neighboring nodes was able to decode the packet, therefore we can only
+ * re-code the packet if the source of the previous encoded packet is involved.
+ * Since the source encoded the packet we can be certain it has all necessary
+ * decode information.
+ *
+ * Returns true if coding of a decoded packet is allowed.
+ */
+static bool batadv_nc_skb_coding_possible(struct sk_buff *skb,
+ uint8_t *dst, uint8_t *src)
+{
+ if (BATADV_SKB_CB(skb)->decoded && !batadv_compare_eth(dst, src))
+ return false;
+ else
+ return true;
+}
+
+/**
+ * batadv_nc_path_search - Find the coding path matching in_nc_node and
+ * out_nc_node to retrieve a buffered packet that can be used for coding.
+ * @bat_priv: the bat priv with all the soft interface information
+ * @in_nc_node: pointer to skb next hop's neighbor nc node
+ * @out_nc_node: pointer to skb source's neighbor nc node
+ * @skb: data skb to forward
+ * @eth_dst: next hop mac address of skb
+ *
+ * Returns true if coding of a decoded skb is allowed.
+ */
+static struct batadv_nc_packet *
+batadv_nc_path_search(struct batadv_priv *bat_priv,
+ struct batadv_nc_node *in_nc_node,
+ struct batadv_nc_node *out_nc_node,
+ struct sk_buff *skb,
+ uint8_t *eth_dst)
+{
+ struct batadv_nc_path *nc_path, nc_path_key;
+ struct batadv_nc_packet *nc_packet_out = NULL;
+ struct batadv_nc_packet *nc_packet, *nc_packet_tmp;
+ struct batadv_hashtable *hash = bat_priv->nc.coding_hash;
+ int idx;
+
+ if (!hash)
+ return NULL;
+
+ /* Create almost path key */
+ batadv_nc_hash_key_gen(&nc_path_key, in_nc_node->addr,
+ out_nc_node->addr);
+ idx = batadv_nc_hash_choose(&nc_path_key, hash->size);
+
+ /* Check for coding opportunities in this nc_path */
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(nc_path, &hash->table[idx], hash_entry) {
+ if (!batadv_compare_eth(nc_path->prev_hop, in_nc_node->addr))
+ continue;
+
+ if (!batadv_compare_eth(nc_path->next_hop, out_nc_node->addr))
+ continue;
+
+ spin_lock_bh(&nc_path->packet_list_lock);
+ if (list_empty(&nc_path->packet_list)) {
+ spin_unlock_bh(&nc_path->packet_list_lock);
+ continue;
+ }
+
+ list_for_each_entry_safe(nc_packet, nc_packet_tmp,
+ &nc_path->packet_list, list) {
+ if (!batadv_nc_skb_coding_possible(nc_packet->skb,
+ eth_dst,
+ in_nc_node->addr))
+ continue;
+
+ /* Coding opportunity is found! */
+ list_del(&nc_packet->list);
+ nc_packet_out = nc_packet;
+ break;
+ }
+
+ spin_unlock_bh(&nc_path->packet_list_lock);
+ break;
+ }
+ rcu_read_unlock();
+
+ return nc_packet_out;
+}
+
+/**
+ * batadv_nc_skb_src_search - Loops through the list of neighoring nodes of the
+ * skb's sender (may be equal to the originator).
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: data skb to forward
+ * @eth_dst: next hop mac address of skb
+ * @eth_src: source mac address of skb
+ * @in_nc_node: pointer to skb next hop's neighbor nc node
+ *
+ * Returns an nc packet if a suitable coding packet was found, NULL otherwise.
+ */
+static struct batadv_nc_packet *
+batadv_nc_skb_src_search(struct batadv_priv *bat_priv,
+ struct sk_buff *skb,
+ uint8_t *eth_dst,
+ uint8_t *eth_src,
+ struct batadv_nc_node *in_nc_node)
+{
+ struct batadv_orig_node *orig_node;
+ struct batadv_nc_node *out_nc_node;
+ struct batadv_nc_packet *nc_packet = NULL;
+
+ orig_node = batadv_orig_hash_find(bat_priv, eth_src);
+ if (!orig_node)
+ return NULL;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(out_nc_node,
+ &orig_node->out_coding_list, list) {
+ /* Check if the skb is decoded and if recoding is possible */
+ if (!batadv_nc_skb_coding_possible(skb,
+ out_nc_node->addr, eth_src))
+ continue;
+
+ /* Search for an opportunity in this nc_path */
+ nc_packet = batadv_nc_path_search(bat_priv, in_nc_node,
+ out_nc_node, skb, eth_dst);
+ if (nc_packet)
+ break;
+ }
+ rcu_read_unlock();
+
+ batadv_orig_node_free_ref(orig_node);
+ return nc_packet;
+}
+
+/**
+ * batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst.
+ * @skb: data skb to forward
+ * @neigh_node: next hop to forward packet to
+ * @ethhdr: pointer to the ethernet header inside the skb
+ *
+ * Loops through list of neighboring nodes the next hop has a good connection to
+ * (receives OGMs with a sufficient quality). We need to find a neighbor of our
+ * next hop that potentially sent a packet which our next hop also received
+ * (overheard) and has stored for later decoding.
+ *
+ * Returns true if the skb was consumed (encoded packet sent) or false otherwise
+ */
+static bool batadv_nc_skb_dst_search(struct sk_buff *skb,
+ struct batadv_neigh_node *neigh_node,
+ struct ethhdr *ethhdr)
+{
+ struct net_device *netdev = neigh_node->if_incoming->soft_iface;
+ struct batadv_priv *bat_priv = netdev_priv(netdev);
+ struct batadv_orig_node *orig_node = neigh_node->orig_node;
+ struct batadv_nc_node *nc_node;
+ struct batadv_nc_packet *nc_packet = NULL;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(nc_node, &orig_node->in_coding_list, list) {
+ /* Search for coding opportunity with this in_nc_node */
+ nc_packet = batadv_nc_skb_src_search(bat_priv, skb,
+ neigh_node->addr,
+ ethhdr->h_source, nc_node);
+
+ /* Opportunity was found, so stop searching */
+ if (nc_packet)
+ break;
+ }
+ rcu_read_unlock();
+
+ if (!nc_packet)
+ return false;
+
+ /* Code and send packets */
+ if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet,
+ neigh_node))
+ return true;
+
+ /* out of mem ? Coding failed - we have to free the buffered packet
+ * to avoid memleaks. The skb passed as argument will be dealt with
+ * by the calling function.
+ */
+ batadv_nc_send_packet(nc_packet);
+ return false;
+}
+
+/**
* batadv_nc_skb_add_to_path - buffer skb for later encoding / decoding
* @skb: skb to add to path
* @nc_path: path to add skb to
@@ -862,6 +1259,10 @@ bool batadv_nc_skb_forward(struct sk_buff *skb,
if (packet->header.packet_type != BATADV_UNICAST)
goto out;
+ /* Try to find a coding opportunity and send the skb if one is found */
+ if (batadv_nc_skb_dst_search(skb, neigh_node, ethhdr))
+ return true;
+
/* Find or create a nc_path for this src-dst pair */
nc_path = batadv_nc_get_path(bat_priv,
bat_priv->nc.coding_hash,
diff --git a/net/batman-adv/packet.h b/net/batman-adv/packet.h
index ed0aa89..a079958 100644
--- a/net/batman-adv/packet.h
+++ b/net/batman-adv/packet.h
@@ -30,6 +30,7 @@ enum batadv_packettype {
BATADV_TT_QUERY = 0x07,
BATADV_ROAM_ADV = 0x08,
BATADV_UNICAST_4ADDR = 0x09,
+ BATADV_CODED = 0x0a,
};
/**
@@ -278,4 +279,36 @@ struct batadv_tt_change {
uint8_t addr[ETH_ALEN];
} __packed;
+/**
+ * struct batadv_coded_packet - network coded packet
+ * @header: common batman packet header and ttl of first included packet
+ * @reserved: Align following fields to 2-byte boundaries
+ * @first_source: original source of first included packet
+ * @first_orig_dest: original destinal of first included packet
+ * @first_crc: checksum of first included packet
+ * @first_ttvn: tt-version number of first included packet
+ * @second_ttl: ttl of second packet
+ * @second_dest: second receiver of this coded packet
+ * @second_source: original source of second included packet
+ * @second_orig_dest: original destination of second included packet
+ * @second_crc: checksum of second included packet
+ * @second_ttvn: tt version number of second included packet
+ * @coded_len: length of network coded part of the payload
+ */
+struct batadv_coded_packet {
+ struct batadv_header header;
+ uint8_t first_ttvn;
+ /* uint8_t first_dest[ETH_ALEN]; - saved in mac header destination */
+ uint8_t first_source[ETH_ALEN];
+ uint8_t first_orig_dest[ETH_ALEN];
+ __be32 first_crc;
+ uint8_t second_ttl;
+ uint8_t second_ttvn;
+ uint8_t second_dest[ETH_ALEN];
+ uint8_t second_source[ETH_ALEN];
+ uint8_t second_orig_dest[ETH_ALEN];
+ __be32 second_crc;
+ uint16_t coded_len;
+};
+
#endif /* _NET_BATMAN_ADV_PACKET_H_ */
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 7188e07..7e463c3 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -665,6 +665,12 @@ static const struct {
{ "dat_put_rx" },
{ "dat_cached_reply_tx" },
#endif
+#ifdef CONFIG_BATMAN_ADV_NC
+ { "nc_code" },
+ { "nc_code_bytes" },
+ { "nc_recode" },
+ { "nc_recode_bytes" },
+#endif
};
static void batadv_get_strings(struct net_device *dev, uint32_t stringset,
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 43caf7f..42d7438 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)
--
LinuxNextTracking
The following commit has been merged in the master branch:
commit 612d2b4fe0a1ff2f8389462a6f8be34e54124c05
Author: Martin Hundebøll <martin(a)hundeboll.net>
Date: Fri Jan 25 11:12:42 2013 +0100
batman-adv: network coding - save overheard and tx packets for decoding
To be able to decode a network coded packet, a node must already know
one of the two coded packets. This is done by buffering skbs before
transmission and buffering packets sniffed with promiscuous mode from
other hosts.
Packets are kept in a buffer similar to the one with forward-skbs: A
hash table, where each entry, which corresponds to a src-dst pair, has a
linked list packets.
Signed-off-by: Martin Hundebøll <martin(a)hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek(a)yahoo.de>
Signed-off-by: Antonio Quartulli <ordex(a)autistici.org>
diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c
index fce2846..3d2ed2f 100644
--- a/net/batman-adv/network-coding.c
+++ b/net/batman-adv/network-coding.c
@@ -27,6 +27,7 @@
#include "hard-interface.h"
static struct lock_class_key batadv_nc_coding_hash_lock_class_key;
+static struct lock_class_key batadv_nc_decoding_hash_lock_class_key;
static void batadv_nc_worker(struct work_struct *work);
@@ -47,8 +48,9 @@ static void batadv_nc_start_timer(struct batadv_priv *bat_priv)
int batadv_nc_init(struct batadv_priv *bat_priv)
{
bat_priv->nc.timestamp_fwd_flush = jiffies;
+ bat_priv->nc.timestamp_sniffed_purge = jiffies;
- if (bat_priv->nc.coding_hash)
+ if (bat_priv->nc.coding_hash || bat_priv->nc.decoding_hash)
return 0;
bat_priv->nc.coding_hash = batadv_hash_new(128);
@@ -58,6 +60,13 @@ int batadv_nc_init(struct batadv_priv *bat_priv)
batadv_hash_set_lock_class(bat_priv->nc.coding_hash,
&batadv_nc_coding_hash_lock_class_key);
+ bat_priv->nc.decoding_hash = batadv_hash_new(128);
+ if (!bat_priv->nc.decoding_hash)
+ goto err;
+
+ batadv_hash_set_lock_class(bat_priv->nc.coding_hash,
+ &batadv_nc_decoding_hash_lock_class_key);
+
INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker);
batadv_nc_start_timer(bat_priv);
@@ -76,6 +85,7 @@ void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv)
atomic_set(&bat_priv->network_coding, 1);
bat_priv->nc.min_tq = 200;
bat_priv->nc.max_fwd_delay = 10;
+ bat_priv->nc.max_buffer_time = 200;
}
/**
@@ -176,6 +186,26 @@ static bool batadv_nc_to_purge_nc_path_coding(struct batadv_priv *bat_priv,
}
/**
+ * batadv_nc_to_purge_nc_path_decoding - checks whether an nc path has timed out
+ * @bat_priv: the bat priv with all the soft interface information
+ * @nc_path: the nc path to check
+ *
+ * Returns true if the entry has to be purged now, false otherwise
+ */
+static bool batadv_nc_to_purge_nc_path_decoding(struct batadv_priv *bat_priv,
+ struct batadv_nc_path *nc_path)
+{
+ if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
+ return true;
+
+ /* purge the path when no packets has been added for 10 times the
+ * max_buffer time
+ */
+ return batadv_has_timed_out(nc_path->last_valid,
+ bat_priv->nc.max_buffer_time*10);
+}
+
+/**
* batadv_nc_purge_orig_nc_nodes - go through list of nc nodes and purge stale
* entries
* @bat_priv: the bat priv with all the soft interface information
@@ -441,6 +471,43 @@ static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet)
}
/**
+ * batadv_nc_sniffed_purge - Checks timestamp of given sniffed nc_packet.
+ * @bat_priv: the bat priv with all the soft interface information
+ * @nc_path: the nc path the packet belongs to
+ * @nc_packet: the nc packet to be checked
+ *
+ * Checks whether the given sniffed (overheard) nc_packet has hit its buffering
+ * timeout. If so, the packet is no longer kept and the entry deleted from the
+ * queue. Has to be called with the appropriate locks.
+ *
+ * Returns false as soon as the entry in the fifo queue has not been timed out
+ * yet and true otherwise.
+ */
+static bool batadv_nc_sniffed_purge(struct batadv_priv *bat_priv,
+ struct batadv_nc_path *nc_path,
+ struct batadv_nc_packet *nc_packet)
+{
+ unsigned long timeout = bat_priv->nc.max_buffer_time;
+ bool res = false;
+
+ /* Packets are added to tail, so the remaining packets did not time
+ * out and we can stop processing the current queue
+ */
+ if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE &&
+ !batadv_has_timed_out(nc_packet->timestamp, timeout))
+ goto out;
+
+ /* purge nc packet */
+ list_del(&nc_packet->list);
+ batadv_nc_packet_free(nc_packet);
+
+ res = true;
+
+out:
+ return res;
+}
+
+/**
* batadv_nc_fwd_flush - Checks the timestamp of the given nc packet.
* @bat_priv: the bat priv with all the soft interface information
* @nc_path: the nc path the packet belongs to
@@ -540,6 +607,8 @@ static void batadv_nc_worker(struct work_struct *work)
batadv_nc_purge_orig_hash(bat_priv);
batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash,
batadv_nc_to_purge_nc_path_coding);
+ batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash,
+ batadv_nc_to_purge_nc_path_decoding);
timeout = bat_priv->nc.max_fwd_delay;
@@ -549,6 +618,13 @@ static void batadv_nc_worker(struct work_struct *work)
bat_priv->nc.timestamp_fwd_flush = jiffies;
}
+ if (batadv_has_timed_out(bat_priv->nc.timestamp_sniffed_purge,
+ bat_priv->nc.max_buffer_time)) {
+ batadv_nc_process_nc_paths(bat_priv, bat_priv->nc.decoding_hash,
+ batadv_nc_sniffed_purge);
+ bat_priv->nc.timestamp_sniffed_purge = jiffies;
+ }
+
/* Schedule a new check */
batadv_nc_start_timer(bat_priv);
}
@@ -1143,6 +1219,41 @@ batadv_nc_skb_src_search(struct batadv_priv *bat_priv,
}
/**
+ * batadv_nc_skb_store_before_coding - set the ethernet src and dst of the
+ * unicast skb before it is stored for use in later decoding
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: data skb to store
+ * @eth_dst_new: new destination mac address of skb
+ */
+static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv,
+ struct sk_buff *skb,
+ uint8_t *eth_dst_new)
+{
+ struct ethhdr *ethhdr;
+
+ /* Copy skb header to change the mac header */
+ skb = pskb_copy(skb, GFP_ATOMIC);
+ if (!skb)
+ return;
+
+ /* Set the mac header as if we actually sent the packet uncoded */
+ ethhdr = (struct ethhdr *)skb_mac_header(skb);
+ memcpy(ethhdr->h_source, ethhdr->h_dest, ETH_ALEN);
+ memcpy(ethhdr->h_dest, eth_dst_new, ETH_ALEN);
+
+ /* Set data pointer to MAC header to mimic packets from our tx path */
+ skb_push(skb, ETH_HLEN);
+
+ /* Add the packet to the decoding packet pool */
+ batadv_nc_skb_store_for_decoding(bat_priv, skb);
+
+ /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free
+ * our ref
+ */
+ kfree_skb(skb);
+}
+
+/**
* batadv_nc_skb_dst_search - Loops through list of neighboring nodes to dst.
* @skb: data skb to forward
* @neigh_node: next hop to forward packet to
@@ -1181,6 +1292,12 @@ static bool batadv_nc_skb_dst_search(struct sk_buff *skb,
if (!nc_packet)
return false;
+ /* Save packets for later decoding */
+ batadv_nc_skb_store_before_coding(bat_priv, skb,
+ neigh_node->addr);
+ batadv_nc_skb_store_before_coding(bat_priv, nc_packet->skb,
+ nc_packet->neigh_node->addr);
+
/* Code and send packets */
if (batadv_nc_code_packets(bat_priv, skb, ethhdr, nc_packet,
neigh_node))
@@ -1288,14 +1405,98 @@ out:
}
/**
+ * batadv_nc_skb_store_for_decoding - save a clone of the skb which can be used
+ * when decoding coded packets
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: data skb to store
+ */
+void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv,
+ struct sk_buff *skb)
+{
+ struct batadv_unicast_packet *packet;
+ struct batadv_nc_path *nc_path;
+ struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
+ __be32 packet_id;
+ u8 *payload;
+
+ /* Check if network coding is enabled */
+ if (!atomic_read(&bat_priv->network_coding))
+ goto out;
+
+ /* Check for supported packet type */
+ payload = skb_network_header(skb);
+ packet = (struct batadv_unicast_packet *)payload;
+ if (packet->header.packet_type != BATADV_UNICAST)
+ goto out;
+
+ /* Find existing nc_path or create a new */
+ nc_path = batadv_nc_get_path(bat_priv,
+ bat_priv->nc.decoding_hash,
+ ethhdr->h_source,
+ ethhdr->h_dest);
+
+ if (!nc_path)
+ goto out;
+
+ /* Clone skb and adjust skb->data to point at batman header */
+ skb = skb_clone(skb, GFP_ATOMIC);
+ if (unlikely(!skb))
+ goto free_nc_path;
+
+ if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
+ goto free_skb;
+
+ if (unlikely(!skb_pull_rcsum(skb, ETH_HLEN)))
+ goto free_skb;
+
+ /* Add skb to nc_path */
+ packet_id = batadv_skb_crc32(skb, payload + sizeof(*packet));
+ if (!batadv_nc_skb_add_to_path(skb, nc_path, NULL, packet_id))
+ goto free_skb;
+
+ batadv_inc_counter(bat_priv, BATADV_CNT_NC_BUFFER);
+ return;
+
+free_skb:
+ kfree_skb(skb);
+free_nc_path:
+ batadv_nc_path_free_ref(nc_path);
+out:
+ return;
+}
+
+/**
+ * batadv_nc_skb_store_sniffed_unicast - check if a received unicast packet
+ * should be saved in the decoding buffer and, if so, store it there
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: unicast skb to store
+ */
+void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv,
+ struct sk_buff *skb)
+{
+ struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
+
+ if (batadv_is_my_mac(ethhdr->h_dest))
+ return;
+
+ /* Set data pointer to MAC header to mimic packets from our tx path */
+ skb_push(skb, ETH_HLEN);
+
+ batadv_nc_skb_store_for_decoding(bat_priv, skb);
+}
+
+/**
* batadv_nc_free - clean up network coding memory
* @bat_priv: the bat priv with all the soft interface information
*/
void batadv_nc_free(struct batadv_priv *bat_priv)
{
cancel_delayed_work_sync(&bat_priv->nc.work);
+
batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL);
batadv_hash_destroy(bat_priv->nc.coding_hash);
+ batadv_nc_purge_paths(bat_priv, bat_priv->nc.decoding_hash, NULL);
+ batadv_hash_destroy(bat_priv->nc.decoding_hash);
}
/**
@@ -1376,6 +1577,11 @@ int batadv_nc_init_debugfs(struct batadv_priv *bat_priv)
if (!file)
goto out;
+ file = debugfs_create_u32("max_buffer_time", S_IRUGO | S_IWUSR, nc_dir,
+ &bat_priv->nc.max_buffer_time);
+ if (!file)
+ goto out;
+
return 0;
out:
diff --git a/net/batman-adv/network-coding.h b/net/batman-adv/network-coding.h
index c32602a..4fa6d0c 100644
--- a/net/batman-adv/network-coding.h
+++ b/net/batman-adv/network-coding.h
@@ -38,6 +38,10 @@ void batadv_nc_init_orig(struct batadv_orig_node *orig_node);
bool batadv_nc_skb_forward(struct sk_buff *skb,
struct batadv_neigh_node *neigh_node,
struct ethhdr *ethhdr);
+void batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv,
+ struct sk_buff *skb);
+void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv,
+ struct sk_buff *skb);
int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset);
int batadv_nc_init_debugfs(struct batadv_priv *bat_priv);
@@ -89,6 +93,20 @@ static inline bool batadv_nc_skb_forward(struct sk_buff *skb,
return false;
}
+static inline void
+batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv,
+ struct sk_buff *skb)
+{
+ return;
+}
+
+static inline void
+batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv,
+ struct sk_buff *skb)
+{
+ return;
+}
+
static inline int batadv_nc_nodes_seq_print_text(struct seq_file *seq,
void *offset)
{
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 44fda7c..8f88967 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -1047,7 +1047,7 @@ int batadv_recv_unicast_packet(struct sk_buff *skb,
struct batadv_unicast_4addr_packet *unicast_4addr_packet;
uint8_t *orig_addr;
struct batadv_orig_node *orig_node = NULL;
- int hdr_size = sizeof(*unicast_packet);
+ int check, hdr_size = sizeof(*unicast_packet);
bool is4addr;
unicast_packet = (struct batadv_unicast_packet *)skb->data;
@@ -1058,7 +1058,16 @@ int batadv_recv_unicast_packet(struct sk_buff *skb,
if (is4addr)
hdr_size = sizeof(*unicast_4addr_packet);
- if (batadv_check_unicast_packet(skb, hdr_size) < 0)
+ /* function returns -EREMOTE for promiscuous packets */
+ check = batadv_check_unicast_packet(skb, hdr_size);
+
+ /* Even though the packet is not for us, we might save it to use for
+ * decoding a later received coded packet
+ */
+ if (check == -EREMOTE)
+ batadv_nc_skb_store_sniffed_unicast(bat_priv, skb);
+
+ if (check < 0)
return NET_RX_DROP;
if (!batadv_check_unicast_ttvn(bat_priv, skb))
diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
index a67cffd..263cfd1 100644
--- a/net/batman-adv/send.c
+++ b/net/batman-adv/send.c
@@ -27,6 +27,7 @@
#include "vis.h"
#include "gateway_common.h"
#include "originator.h"
+#include "network-coding.h"
#include <linux/if_ether.h>
@@ -39,6 +40,7 @@ int batadv_send_skb_packet(struct sk_buff *skb,
struct batadv_hard_iface *hard_iface,
const uint8_t *dst_addr)
{
+ struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
struct ethhdr *ethhdr;
if (hard_iface->if_status != BATADV_IF_ACTIVE)
@@ -70,6 +72,9 @@ int batadv_send_skb_packet(struct sk_buff *skb,
skb->dev = hard_iface->net_dev;
+ /* Save a clone of the skb to use when decoding coded packets */
+ batadv_nc_skb_store_for_decoding(bat_priv, skb);
+
/* dev_queue_xmit() returns a negative result on error. However on
* congestion and traffic shaping, it drops and returns NET_XMIT_DROP
* (which is > 0). This will not be treated as an error.
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 7e463c3..75204ec 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -670,6 +670,7 @@ static const struct {
{ "nc_code_bytes" },
{ "nc_recode" },
{ "nc_recode_bytes" },
+ { "nc_buffer" },
#endif
};
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 42d7438..5f3640d 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -279,6 +279,7 @@ struct batadv_bcast_duplist_entry {
* @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_NC_BUFFER: counter for packets buffered for later nc decoding
* @BATADV_CNT_NUM: number of traffic counters
*/
enum batadv_counters {
@@ -311,6 +312,7 @@ enum batadv_counters {
BATADV_CNT_NC_CODE_BYTES,
BATADV_CNT_NC_RECODE,
BATADV_CNT_NC_RECODE_BYTES,
+ BATADV_CNT_NC_BUFFER,
#endif
BATADV_CNT_NUM,
};
@@ -453,18 +455,27 @@ struct batadv_priv_dat {
* @debug_dir: dentry for nc subdir in batman-adv directory in debugfs
* @min_tq: only consider neighbors for encoding if neigh_tq > min_tq
* @max_fwd_delay: maximum packet forward delay to allow coding of packets
+ * @max_buffer_time: buffer time for sniffed packets used to decoding
* @timestamp_fwd_flush: timestamp of last forward packet queue flush
+ * @timestamp_sniffed_purge: timestamp of last sniffed packet queue purge
* @coding_hash: Hash table used to buffer skbs while waiting for another
* incoming skb to code it with. Skbs are added to the buffer just before being
* forwarded in routing.c
+ * @decoding_hash: Hash table used to buffer skbs that might be needed to decode
+ * a received coded skb. The buffer is used for 1) skbs arriving on the
+ * soft-interface; 2) skbs overheard on the hard-interface; and 3) skbs
+ * forwarded by batman-adv.
*/
struct batadv_priv_nc {
struct delayed_work work;
struct dentry *debug_dir;
u8 min_tq;
u32 max_fwd_delay;
+ u32 max_buffer_time;
unsigned long timestamp_fwd_flush;
+ unsigned long timestamp_sniffed_purge;
struct batadv_hashtable *coding_hash;
+ struct batadv_hashtable *decoding_hash;
};
/**
--
LinuxNextTracking
The following commit has been merged in the master branch:
commit f86ce0ad107bc0e33ead8ba2498fc22dfb747479
Author: Martin Hundebøll <martin(a)hundeboll.net>
Date: Mon Jan 14 00:20:32 2013 +0100
batman-adv: Return reason for failure in batadv_check_unicast_packet()
batadv_check_unicast_packet() is changed to return a value based on the
reason to drop the packet, which will be useful information for
future users of batadv_check_unicast_packet().
Signed-off-by: Martin Hundebøll <martin(a)hundeboll.net>
Acked-by: Antonio Quartulli <ordex(a)autistici.org>
Signed-off-by: Marek Lindner <lindner_marek(a)yahoo.de>
Signed-off-by: Antonio Quartulli <ordex(a)autistici.org>
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 5ee21ce..322c97a 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -548,27 +548,37 @@ batadv_find_ifalter_router(struct batadv_orig_node *primary_orig,
return router;
}
+/**
+ * batadv_check_unicast_packet - Check for malformed unicast packets
+ * @skb: packet to check
+ * @hdr_size: size of header to pull
+ *
+ * Check for short header and bad addresses in given packet. Returns negative
+ * value when check fails and 0 otherwise. The negative value depends on the
+ * reason: -ENODATA for bad header, -EBADR for broadcast destination or source,
+ * and -EREMOTE for non-local (other host) destination.
+ */
static int batadv_check_unicast_packet(struct sk_buff *skb, int hdr_size)
{
struct ethhdr *ethhdr;
/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb, hdr_size)))
- return -1;
+ return -ENODATA;
ethhdr = (struct ethhdr *)skb_mac_header(skb);
/* packet with unicast indication but broadcast recipient */
if (is_broadcast_ether_addr(ethhdr->h_dest))
- return -1;
+ return -EBADR;
/* packet with broadcast sender address */
if (is_broadcast_ether_addr(ethhdr->h_source))
- return -1;
+ return -EBADR;
/* not for me */
if (!batadv_is_my_mac(ethhdr->h_dest))
- return -1;
+ return -EREMOTE;
return 0;
}
--
LinuxNextTracking
The following commit has been merged in the master branch:
commit d353d8d4d9f0184ac43a90c6e04b593c33bd28ea
Author: Martin Hundebøll <martin(a)hundeboll.net>
Date: Fri Jan 25 11:12:38 2013 +0100
batman-adv: network coding - add the initial infrastructure code
Network coding exploits the 802.11 shared medium to allow multiple
packets to be sent in a single transmission. In brief, a relay can XOR
two packets, and send the coded packet to two destinations. The
receivers can decode one of the original packets by XOR'ing the coded
packet with the other original packet. This will lead to increased
throughput in topologies where two packets cross one relay.
In a simple topology with three nodes, it takes four transmissions
without network coding to get one packet from Node A to Node B and one
from Node B to Node A:
1. Node A ---- p1 ---> Node R Node B
2. Node A Node R <--- p2 ---- Node B
3. Node A <--- p2 ---- Node R Node B
4. Node A Node R ---- p1 ---> Node B
With network coding, the relay only needs one transmission, which saves
us one slot of valuable airtime:
1. Node A ---- p1 ---> Node R Node B
2. Node A Node R <--- p2 ---- Node B
3. Node A <- p1 x p2 - Node R - p1 x p2 -> Node B
The same principle holds for a topology including five nodes. Here the
packets from Node A and Node B are overheard by Node C and Node D,
respectively. This allows Node R to send a network coded packet to save
one transmission:
Node A Node B
| \ / |
| p1 p2 |
| \ / |
p1 > Node R < p2
| |
| / \ |
| p1 x p2 p1 x p2 |
v / \ v
/ \
Node C < > Node D
More information is available on the open-mesh.org wiki[1].
This patch adds the initial code to support network coding in
batman-adv. It sets up a worker thread to do house keeping and adds a
sysfs file to enable/disable network coding. The feature is disabled by
default, as it requires a wifi-driver with working promiscuous mode, and
also because it adds a small delay at each hop.
[1] http://www.open-mesh.org/projects/batman-adv/wiki/Catwoman
Signed-off-by: Martin Hundebøll <martin(a)hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek(a)yahoo.de>
Signed-off-by: Antonio Quartulli <ordex(a)autistici.org>
diff --git a/Documentation/ABI/testing/sysfs-class-net-mesh b/Documentation/ABI/testing/sysfs-class-net-mesh
index bc41da6..bdcd8b4 100644
--- a/Documentation/ABI/testing/sysfs-class-net-mesh
+++ b/Documentation/ABI/testing/sysfs-class-net-mesh
@@ -67,6 +67,14 @@ Description:
Defines the penalty which will be applied to an
originator message's tq-field on every hop.
+What: /sys/class/net/<mesh_iface>/mesh/network_coding
+Date: Nov 2012
+Contact: Martin Hundeboll <martin(a)hundeboll.net>
+Description:
+ Controls whether Network Coding (using some magic
+ to send fewer wifi packets but still the same
+ content) is enabled or not.
+
What: /sys/class/net/<mesh_iface>/mesh/orig_interval
Date: May 2010
Contact: Marek Lindner <lindner_marek(a)yahoo.de>
diff --git a/net/batman-adv/Kconfig b/net/batman-adv/Kconfig
index 8d8afb1..fa780b7 100644
--- a/net/batman-adv/Kconfig
+++ b/net/batman-adv/Kconfig
@@ -36,6 +36,20 @@ config BATMAN_ADV_DAT
mesh networks. If you think that your network does not need
this option you can safely remove it and save some space.
+config BATMAN_ADV_NC
+ bool "Network Coding"
+ depends on BATMAN_ADV
+ default n
+ help
+ This option enables network coding, a mechanism that aims to
+ increase the overall network throughput by fusing multiple
+ packets in one transmission.
+ Note that interfaces controlled by batman-adv must be manually
+ configured to have promiscuous mode enabled in order to make
+ network coding work.
+ If you think that your network does not need this feature you
+ can safely disable it and save some space.
+
config BATMAN_ADV_DEBUG
bool "B.A.T.M.A.N. debugging"
depends on BATMAN_ADV
diff --git a/net/batman-adv/Makefile b/net/batman-adv/Makefile
index e45e3b4..4b8f192 100644
--- a/net/batman-adv/Makefile
+++ b/net/batman-adv/Makefile
@@ -30,6 +30,7 @@ batman-adv-y += hard-interface.o
batman-adv-y += hash.o
batman-adv-y += icmp_socket.o
batman-adv-y += main.o
+batman-adv-$(CONFIG_BATMAN_ADV_NC) += network-coding.o
batman-adv-y += originator.o
batman-adv-y += ring_buffer.o
batman-adv-y += routing.o
diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index 0488d70..0495a7d 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -35,6 +35,7 @@
#include "vis.h"
#include "hash.h"
#include "bat_algo.h"
+#include "network-coding.h"
/* List manipulations on hardif_list have to be rtnl_lock()'ed,
@@ -135,6 +136,10 @@ int batadv_mesh_init(struct net_device *soft_iface)
if (ret < 0)
goto err;
+ ret = batadv_nc_init(bat_priv);
+ if (ret < 0)
+ goto err;
+
atomic_set(&bat_priv->gw.reselect, 0);
atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
@@ -157,6 +162,7 @@ void batadv_mesh_free(struct net_device *soft_iface)
batadv_gw_node_purge(bat_priv);
batadv_originator_free(bat_priv);
+ batadv_nc_free(bat_priv);
batadv_tt_free(bat_priv);
diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h
index ced08b9..59ba2ff 100644
--- a/net/batman-adv/main.h
+++ b/net/batman-adv/main.h
@@ -185,6 +185,7 @@ __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr);
* @BATADV_DBG_TT: translation table messages
* @BATADV_DBG_BLA: bridge loop avoidance messages
* @BATADV_DBG_DAT: ARP snooping and DAT related messages
+ * @BATADV_DBG_NC: network coding related messages
* @BATADV_DBG_ALL: the union of all the above log levels
*/
enum batadv_dbg_level {
@@ -193,7 +194,8 @@ enum batadv_dbg_level {
BATADV_DBG_TT = BIT(2),
BATADV_DBG_BLA = BIT(3),
BATADV_DBG_DAT = BIT(4),
- BATADV_DBG_ALL = 31,
+ BATADV_DBG_NC = BIT(5),
+ BATADV_DBG_ALL = 63,
};
#ifdef CONFIG_BATMAN_ADV_DEBUG
diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c
new file mode 100644
index 0000000..9c2d54b
--- /dev/null
+++ b/net/batman-adv/network-coding.c
@@ -0,0 +1,81 @@
+/* Copyright (C) 2012-2013 B.A.T.M.A.N. contributors:
+ *
+ * Martin Hundebøll, Jeppe Ledet-Pedersen
+ *
+ * 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
+ */
+
+#include "main.h"
+#include "network-coding.h"
+
+static void batadv_nc_worker(struct work_struct *work);
+
+/**
+ * batadv_nc_start_timer - initialise the nc periodic worker
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_nc_start_timer(struct batadv_priv *bat_priv)
+{
+ queue_delayed_work(batadv_event_workqueue, &bat_priv->nc.work,
+ msecs_to_jiffies(10));
+}
+
+/**
+ * batadv_nc_init - initialise coding hash table and start house keeping
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+int batadv_nc_init(struct batadv_priv *bat_priv)
+{
+ INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker);
+ batadv_nc_start_timer(bat_priv);
+
+ return 0;
+}
+
+/**
+ * batadv_nc_init_bat_priv - initialise the nc specific bat_priv variables
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv)
+{
+ atomic_set(&bat_priv->network_coding, 1);
+}
+
+/**
+ * batadv_nc_worker - periodic task for house keeping related to network coding
+ * @work: kernel work struct
+ */
+static void batadv_nc_worker(struct work_struct *work)
+{
+ struct delayed_work *delayed_work;
+ struct batadv_priv_nc *priv_nc;
+ struct batadv_priv *bat_priv;
+
+ delayed_work = container_of(work, struct delayed_work, work);
+ priv_nc = container_of(delayed_work, struct batadv_priv_nc, work);
+ bat_priv = container_of(priv_nc, struct batadv_priv, nc);
+
+ /* Schedule a new check */
+ batadv_nc_start_timer(bat_priv);
+}
+
+/**
+ * batadv_nc_free - clean up network coding memory
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+void batadv_nc_free(struct batadv_priv *bat_priv)
+{
+ cancel_delayed_work_sync(&bat_priv->nc.work);
+}
diff --git a/net/batman-adv/network-coding.h b/net/batman-adv/network-coding.h
new file mode 100644
index 0000000..7483cba
--- /dev/null
+++ b/net/batman-adv/network-coding.h
@@ -0,0 +1,48 @@
+/* Copyright (C) 2012-2013 B.A.T.M.A.N. contributors:
+ *
+ * Martin Hundebøll, Jeppe Ledet-Pedersen
+ *
+ * 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_NETWORK_CODING_H_
+#define _NET_BATMAN_ADV_NETWORK_CODING_H_
+
+#ifdef CONFIG_BATMAN_ADV_NC
+
+int batadv_nc_init(struct batadv_priv *bat_priv);
+void batadv_nc_free(struct batadv_priv *bat_priv);
+void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv);
+
+#else /* ifdef CONFIG_BATMAN_ADV_NC */
+
+static inline int batadv_nc_init(struct batadv_priv *bat_priv)
+{
+ return 0;
+}
+
+static inline void batadv_nc_free(struct batadv_priv *bat_priv)
+{
+ return;
+}
+
+static inline void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv)
+{
+ return;
+}
+
+#endif /* ifdef CONFIG_BATMAN_ADV_NC */
+
+#endif /* _NET_BATMAN_ADV_NETWORK_CODING_H_ */
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 2711e87..7188e07 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -37,6 +37,7 @@
#include <linux/if_ether.h>
#include "unicast.h"
#include "bridge_loop_avoidance.h"
+#include "network-coding.h"
static int batadv_get_settings(struct net_device *dev, struct ethtool_cmd *cmd);
@@ -544,6 +545,8 @@ struct net_device *batadv_softif_create(const char *name)
if (ret < 0)
goto unreg_soft_iface;
+ batadv_nc_init_bat_priv(bat_priv);
+
ret = batadv_sysfs_add_meshif(soft_iface);
if (ret < 0)
goto unreg_soft_iface;
diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c
index 6a44fed..ce39f62 100644
--- a/net/batman-adv/sysfs.c
+++ b/net/batman-adv/sysfs.c
@@ -442,6 +442,9 @@ static BATADV_ATTR(gw_bandwidth, S_IRUGO | S_IWUSR, batadv_show_gw_bwidth,
#ifdef CONFIG_BATMAN_ADV_DEBUG
BATADV_ATTR_SIF_UINT(log_level, S_IRUGO | S_IWUSR, 0, BATADV_DBG_ALL, NULL);
#endif
+#ifdef CONFIG_BATMAN_ADV_NC
+BATADV_ATTR_SIF_BOOL(network_coding, S_IRUGO | S_IWUSR, NULL);
+#endif
static struct batadv_attribute *batadv_mesh_attrs[] = {
&batadv_attr_aggregated_ogms,
@@ -464,6 +467,9 @@ static struct batadv_attribute *batadv_mesh_attrs[] = {
#ifdef CONFIG_BATMAN_ADV_DEBUG
&batadv_attr_log_level,
#endif
+#ifdef CONFIG_BATMAN_ADV_NC
+ &batadv_attr_network_coding,
+#endif
NULL,
};
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 4cd87a0..83bfe7c 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -428,6 +428,14 @@ struct batadv_priv_dat {
#endif
/**
+ * struct batadv_priv_nc - per mesh interface network coding private data
+ * @work: work queue callback item for cleanup
+ */
+struct batadv_priv_nc {
+ struct delayed_work work;
+};
+
+/**
* struct batadv_priv - per mesh interface data
* @mesh_state: current status of the mesh (inactive/active/deactivating)
* @soft_iface: net device which holds this struct as private data
@@ -470,6 +478,8 @@ struct batadv_priv_dat {
* @tt: translation table data
* @vis: vis data
* @dat: distributed arp table data
+ * @network_coding: bool indicating whether network coding is enabled
+ * @batadv_priv_nc: network coding data
*/
struct batadv_priv {
atomic_t mesh_state;
@@ -522,6 +532,10 @@ struct batadv_priv {
#ifdef CONFIG_BATMAN_ADV_DAT
struct batadv_priv_dat dat;
#endif
+#ifdef CONFIG_BATMAN_ADV_NC
+ atomic_t network_coding;
+ struct batadv_priv_nc nc;
+#endif /* CONFIG_BATMAN_ADV_NC */
};
/**
--
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