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linux/net/batman-adv/network-coding.h

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batman-adv: update copyright years for 2014 Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2014-01-04 17:04:25 +00:00
/* Copyright (C) 2012-2014 B.A.T.M.A.N. contributors:
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@hundeboll.net> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-01-25 10:12:38 +00:00
*
* 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
batman-adv: remove FSF address from GPL disclaimer As suggested by checkpatch, remove all the references to the FSF address since the kernel already has one reference in its documentation. In this way it is easier to update it in case of future changes. Signed-off-by: Antonio Quartulli <antonio@meshcoding.com> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
2013-11-03 19:40:48 +00:00
* along with this program; if not, see <http://www.gnu.org/licenses/>.
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@hundeboll.net> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-01-25 10:12:38 +00:00
*/
#ifndef _NET_BATMAN_ADV_NETWORK_CODING_H_
#define _NET_BATMAN_ADV_NETWORK_CODING_H_
#ifdef CONFIG_BATMAN_ADV_NC
batman-adv: tvlv - add network coding container Create network coding container to announce network coding capabilities (if enabled). Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-04-23 13:40:00 +00:00
void batadv_nc_status_update(struct net_device *net_dev);
batman-adv: set up network coding packet handlers during module init batman-adv saves its table of packet handlers as a global state, so handlers must be set up only once (and setting them up a second time will fail). The recently-added network coding support tries to set up its handler each time a new softif is registered, which obviously fails when more that one softif is used (and in consequence, the softif creation fails). Fix this by splitting up batadv_nc_init into batadv_nc_init (which is called only once) and batadv_nc_mesh_init (which is called for each softif); in addition batadv_nc_free is renamed to batadv_nc_mesh_free to keep naming consistent. Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-09-27 16:03:39 +00:00
int batadv_nc_init(void);
int batadv_nc_mesh_init(struct batadv_priv *bat_priv);
void batadv_nc_mesh_free(struct batadv_priv *bat_priv);
batman-adv: network coding - detect coding nodes and remove these after timeout To use network coding efficiently, a relay must know when neighbor nodes are likely to have enough information to be able to decode a network coded packet. This is detected by using OGMs from batman-adv to discover when one neighbor is in range of another neighbor. The relay check the TLL to detect when an OGM is forwarded from one neighbor by another neighbor, and thereby knows that the two neighbors are in range and thus overhear packets sent by each other. This information is saved in the orig_node struct to be used when searching for coding opportunities. Two lists are added to the orig_node struct: One for neighbors that can hear the orig_node (outgoing nc_nodes) and one for neighbors that the orig_node can hear (incoming nc_nodes). Information about nc_nodes is kept for 10 seconds and is available through debugfs in batman_adv/nc_nodes to use when debugging network coding. 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>
2013-01-25 10:12:39 +00:00
void batadv_nc_update_nc_node(struct batadv_priv *bat_priv,
struct batadv_orig_node *orig_node,
struct batadv_orig_node *orig_neigh_node,
struct batadv_ogm_packet *ogm_packet,
int is_single_hop_neigh);
void batadv_nc_purge_orig(struct batadv_priv *bat_priv,
struct batadv_orig_node *orig_node,
bool (*to_purge)(struct batadv_priv *,
struct batadv_nc_node *));
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@hundeboll.net> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-01-25 10:12:38 +00:00
void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv);
batman-adv: network coding - detect coding nodes and remove these after timeout To use network coding efficiently, a relay must know when neighbor nodes are likely to have enough information to be able to decode a network coded packet. This is detected by using OGMs from batman-adv to discover when one neighbor is in range of another neighbor. The relay check the TLL to detect when an OGM is forwarded from one neighbor by another neighbor, and thereby knows that the two neighbors are in range and thus overhear packets sent by each other. This information is saved in the orig_node struct to be used when searching for coding opportunities. Two lists are added to the orig_node struct: One for neighbors that can hear the orig_node (outgoing nc_nodes) and one for neighbors that the orig_node can hear (incoming nc_nodes). Information about nc_nodes is kept for 10 seconds and is available through debugfs in batman_adv/nc_nodes to use when debugging network coding. 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>
2013-01-25 10:12:39 +00:00
void batadv_nc_init_orig(struct batadv_orig_node *orig_node);
batman-adv: network coding - buffer unicast packets before forward Two be able to network code two packets, one packet must be buffered until the next is available. This is done in a "coding buffer", which is essentially a hash table with lists of packets. Each entry in the hash table corresponds to a specific src-dst pair, which has a linked list of packets that are buffered. This patch adds skbs to the buffer just before forwarding them. The buffer is traversed every 10 ms, where timed skbs are removed from the buffer and transmitted. To allow experiments with the network coding scheme, the timeout is tunable through a file in debugfs. 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>
2013-01-25 10:12:40 +00:00
bool batadv_nc_skb_forward(struct sk_buff *skb,
batman-adv: Move call to batadv_nc_skb_forward() from routing.c to send.c The call to batadv_nc_skb_forward() fits better in batadv_send_skb_to_orig(), as this is where the actual next hop is looked up. To let the caller of batadv_send_skb_to_orig() know wether the skb is transmitted, buffered or failed, the return value is changed from boolean to int. 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>
2013-04-20 11:54:39 +00:00
struct batadv_neigh_node *neigh_node);
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@hundeboll.net> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-01-25 10:12:42 +00:00
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);
batman-adv: network coding - detect coding nodes and remove these after timeout To use network coding efficiently, a relay must know when neighbor nodes are likely to have enough information to be able to decode a network coded packet. This is detected by using OGMs from batman-adv to discover when one neighbor is in range of another neighbor. The relay check the TLL to detect when an OGM is forwarded from one neighbor by another neighbor, and thereby knows that the two neighbors are in range and thus overhear packets sent by each other. This information is saved in the orig_node struct to be used when searching for coding opportunities. Two lists are added to the orig_node struct: One for neighbors that can hear the orig_node (outgoing nc_nodes) and one for neighbors that the orig_node can hear (incoming nc_nodes). Information about nc_nodes is kept for 10 seconds and is available through debugfs in batman_adv/nc_nodes to use when debugging network coding. 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>
2013-01-25 10:12:39 +00:00
int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset);
int batadv_nc_init_debugfs(struct batadv_priv *bat_priv);
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@hundeboll.net> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-01-25 10:12:38 +00:00
#else /* ifdef CONFIG_BATMAN_ADV_NC */
batman-adv: tvlv - add network coding container Create network coding container to announce network coding capabilities (if enabled). Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-04-23 13:40:00 +00:00
static inline void batadv_nc_status_update(struct net_device *net_dev)
{
}
batman-adv: set up network coding packet handlers during module init batman-adv saves its table of packet handlers as a global state, so handlers must be set up only once (and setting them up a second time will fail). The recently-added network coding support tries to set up its handler each time a new softif is registered, which obviously fails when more that one softif is used (and in consequence, the softif creation fails). Fix this by splitting up batadv_nc_init into batadv_nc_init (which is called only once) and batadv_nc_mesh_init (which is called for each softif); in addition batadv_nc_free is renamed to batadv_nc_mesh_free to keep naming consistent. Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-09-27 16:03:39 +00:00
static inline int batadv_nc_init(void)
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@hundeboll.net> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-01-25 10:12:38 +00:00
{
return 0;
}
batman-adv: set up network coding packet handlers during module init batman-adv saves its table of packet handlers as a global state, so handlers must be set up only once (and setting them up a second time will fail). The recently-added network coding support tries to set up its handler each time a new softif is registered, which obviously fails when more that one softif is used (and in consequence, the softif creation fails). Fix this by splitting up batadv_nc_init into batadv_nc_init (which is called only once) and batadv_nc_mesh_init (which is called for each softif); in addition batadv_nc_free is renamed to batadv_nc_mesh_free to keep naming consistent. Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-09-27 16:03:39 +00:00
static inline int batadv_nc_mesh_init(struct batadv_priv *bat_priv)
{
return 0;
}
static inline void batadv_nc_mesh_free(struct batadv_priv *bat_priv)
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@hundeboll.net> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-01-25 10:12:38 +00:00
{
}
batman-adv: network coding - detect coding nodes and remove these after timeout To use network coding efficiently, a relay must know when neighbor nodes are likely to have enough information to be able to decode a network coded packet. This is detected by using OGMs from batman-adv to discover when one neighbor is in range of another neighbor. The relay check the TLL to detect when an OGM is forwarded from one neighbor by another neighbor, and thereby knows that the two neighbors are in range and thus overhear packets sent by each other. This information is saved in the orig_node struct to be used when searching for coding opportunities. Two lists are added to the orig_node struct: One for neighbors that can hear the orig_node (outgoing nc_nodes) and one for neighbors that the orig_node can hear (incoming nc_nodes). Information about nc_nodes is kept for 10 seconds and is available through debugfs in batman_adv/nc_nodes to use when debugging network coding. 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>
2013-01-25 10:12:39 +00:00
static inline void
batadv_nc_update_nc_node(struct batadv_priv *bat_priv,
struct batadv_orig_node *orig_node,
struct batadv_orig_node *orig_neigh_node,
struct batadv_ogm_packet *ogm_packet,
int is_single_hop_neigh)
{
}
static inline void
batadv_nc_purge_orig(struct batadv_priv *bat_priv,
struct batadv_orig_node *orig_node,
bool (*to_purge)(struct batadv_priv *,
struct batadv_nc_node *))
{
}
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@hundeboll.net> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-01-25 10:12:38 +00:00
static inline void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv)
{
}
batman-adv: network coding - detect coding nodes and remove these after timeout To use network coding efficiently, a relay must know when neighbor nodes are likely to have enough information to be able to decode a network coded packet. This is detected by using OGMs from batman-adv to discover when one neighbor is in range of another neighbor. The relay check the TLL to detect when an OGM is forwarded from one neighbor by another neighbor, and thereby knows that the two neighbors are in range and thus overhear packets sent by each other. This information is saved in the orig_node struct to be used when searching for coding opportunities. Two lists are added to the orig_node struct: One for neighbors that can hear the orig_node (outgoing nc_nodes) and one for neighbors that the orig_node can hear (incoming nc_nodes). Information about nc_nodes is kept for 10 seconds and is available through debugfs in batman_adv/nc_nodes to use when debugging network coding. 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>
2013-01-25 10:12:39 +00:00
static inline void batadv_nc_init_orig(struct batadv_orig_node *orig_node)
{
}
batman-adv: network coding - buffer unicast packets before forward Two be able to network code two packets, one packet must be buffered until the next is available. This is done in a "coding buffer", which is essentially a hash table with lists of packets. Each entry in the hash table corresponds to a specific src-dst pair, which has a linked list of packets that are buffered. This patch adds skbs to the buffer just before forwarding them. The buffer is traversed every 10 ms, where timed skbs are removed from the buffer and transmitted. To allow experiments with the network coding scheme, the timeout is tunable through a file in debugfs. 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>
2013-01-25 10:12:40 +00:00
static inline bool batadv_nc_skb_forward(struct sk_buff *skb,
batman-adv: Move call to batadv_nc_skb_forward() from routing.c to send.c The call to batadv_nc_skb_forward() fits better in batadv_send_skb_to_orig(), as this is where the actual next hop is looked up. To let the caller of batadv_send_skb_to_orig() know wether the skb is transmitted, buffered or failed, the return value is changed from boolean to int. 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>
2013-04-20 11:54:39 +00:00
struct batadv_neigh_node *neigh_node)
batman-adv: network coding - buffer unicast packets before forward Two be able to network code two packets, one packet must be buffered until the next is available. This is done in a "coding buffer", which is essentially a hash table with lists of packets. Each entry in the hash table corresponds to a specific src-dst pair, which has a linked list of packets that are buffered. This patch adds skbs to the buffer just before forwarding them. The buffer is traversed every 10 ms, where timed skbs are removed from the buffer and transmitted. To allow experiments with the network coding scheme, the timeout is tunable through a file in debugfs. 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>
2013-01-25 10:12:40 +00:00
{
return false;
}
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@hundeboll.net> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-01-25 10:12:42 +00:00
static inline void
batadv_nc_skb_store_for_decoding(struct batadv_priv *bat_priv,
struct sk_buff *skb)
{
}
static inline void
batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv,
struct sk_buff *skb)
{
}
batman-adv: network coding - detect coding nodes and remove these after timeout To use network coding efficiently, a relay must know when neighbor nodes are likely to have enough information to be able to decode a network coded packet. This is detected by using OGMs from batman-adv to discover when one neighbor is in range of another neighbor. The relay check the TLL to detect when an OGM is forwarded from one neighbor by another neighbor, and thereby knows that the two neighbors are in range and thus overhear packets sent by each other. This information is saved in the orig_node struct to be used when searching for coding opportunities. Two lists are added to the orig_node struct: One for neighbors that can hear the orig_node (outgoing nc_nodes) and one for neighbors that the orig_node can hear (incoming nc_nodes). Information about nc_nodes is kept for 10 seconds and is available through debugfs in batman_adv/nc_nodes to use when debugging network coding. 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>
2013-01-25 10:12:39 +00:00
static inline int batadv_nc_nodes_seq_print_text(struct seq_file *seq,
void *offset)
{
return 0;
}
static inline int batadv_nc_init_debugfs(struct batadv_priv *bat_priv)
{
return 0;
}
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@hundeboll.net> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-01-25 10:12:38 +00:00
#endif /* ifdef CONFIG_BATMAN_ADV_NC */
#endif /* _NET_BATMAN_ADV_NETWORK_CODING_H_ */
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