Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-29 15:41:36 +00:00
Code Issues Packages Projects Releases Wiki Activity
ce48ebdd56
linux/net/batman-adv/network-coding.h

107 lines
2.7 KiB
C
Raw Normal View History

batman-adv: Add SPDX license identifier above copyright header The "Linux kernel licensing rules" require that each file has a SPDX license identifier as first line (and sometimes as second line). The FSFE REUSE practices [1] would also require the same tags but have no restrictions on the placement in the source file. Using the "Linux kernel licensing rules" is therefore also fulfilling the FSFE REUSE practices requirements at the same time. [1] https://reuse.software/practices/ Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2017-11-19 14:05:11 +00:00
/* SPDX-License-Identifier: GPL-2.0 */
batman-adv: Drop publication years from copyright info The batman-adv source code was using the year of publication (to net-next) as "last" year for the copyright statement. The whole source code mentioned in the MAINTAINERS "BATMAN ADVANCED" section was handled as a single entity regarding the publishing year. This avoided having outdated (in sense of year information - not copyright holder) publishing information inside several files. But since the simple "update copyright year" commit (without other changes) in the file was not well received in the upstream kernel, the option to not have a copyright year (for initial and last publication) in the files are chosen instead. More detailed information about the years can still be retrieved from the SCM system. Signed-off-by: Sven Eckelmann <sven@narfation.org> Acked-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2020-12-31 23:00:01 +00:00
/* Copyright (C) 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
*/
#ifndef _NET_BATMAN_ADV_NETWORK_CODING_H_
#define _NET_BATMAN_ADV_NETWORK_CODING_H_
batman-adv: Add required includes to all files The header files could not be build indepdent from each other. This is happened because headers didn't include the files for things they've used. This was problematic because the success of a build depended on the knowledge about the right order of local includes. Also source files were not including everything they've used explicitly. Instead they required that transitive includes are always stable. This is problematic because some transitive includes are not obvious, depend on config settings and may not be stable in the future. The order for include blocks are: * primary headers (main.h and the *.h file of a *.c file) * global linux headers * required local headers * extra forward declarations for pointers in function/struct declarations The only exceptions are linux/bitops.h and linux/if_ether.h in packet.h. This header file is shared with userspace applications like batctl and must therefore build together with userspace applications. The header linux/bitops.h is not part of the uapi headers and linux/if_ether.h conflicts with the musl implementation of netinet/if_ether.h. The maintainers rejected the use of __KERNEL__ preprocessor checks and thus these two headers are only in main.h. All files using packet.h first have to include main.h to work correctly. Reported-by: Markus Pargmann <mpa@pengutronix.de> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
2015-04-17 17:40:28 +00:00
#include "main.h"
batman-adv: Use includes instead of fwdecls While it can be slightly beneficial for the build performance to use forward declarations instead of includes, the handling of them together with changes in the included headers makes it unnecessary complicated and fragile. Just replace them with actual includes since some parts (hwmon, ..) of the kernel even request avoidance of forward declarations and net/ is mostly not using them in *.c file. Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2019-05-24 18:11:17 +00:00
#include <linux/netdevice.h>
#include <linux/skbuff.h>
batman-adv: Add required includes to all files The header files could not be build indepdent from each other. This is happened because headers didn't include the files for things they've used. This was problematic because the success of a build depended on the knowledge about the right order of local includes. Also source files were not including everything they've used explicitly. Instead they required that transitive includes are always stable. This is problematic because some transitive includes are not obvious, depend on config settings and may not be stable in the future. The order for include blocks are: * primary headers (main.h and the *.h file of a *.c file) * global linux headers * required local headers * extra forward declarations for pointers in function/struct declarations The only exceptions are linux/bitops.h and linux/if_ether.h in packet.h. This header file is shared with userspace applications like batctl and must therefore build together with userspace applications. The header linux/bitops.h is not part of the uapi headers and linux/if_ether.h conflicts with the musl implementation of netinet/if_ether.h. The maintainers rejected the use of __KERNEL__ preprocessor checks and thus these two headers are only in main.h. All files using packet.h first have to include main.h to work correctly. Reported-by: Markus Pargmann <mpa@pengutronix.de> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
2015-04-17 17:40:28 +00:00
#include <linux/types.h>
batman-adv: Use includes instead of fwdecls While it can be slightly beneficial for the build performance to use forward declarations instead of includes, the handling of them together with changes in the included headers makes it unnecessary complicated and fragile. Just replace them with actual includes since some parts (hwmon, ..) of the kernel even request avoidance of forward declarations and net/ is mostly not using them in *.c file. Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2019-05-24 18:11:17 +00:00
#include <uapi/linux/batadv_packet.h>
batman-adv: Add required includes to all files The header files could not be build indepdent from each other. This is happened because headers didn't include the files for things they've used. This was problematic because the success of a build depended on the knowledge about the right order of local includes. Also source files were not including everything they've used explicitly. Instead they required that transitive includes are always stable. This is problematic because some transitive includes are not obvious, depend on config settings and may not be stable in the future. The order for include blocks are: * primary headers (main.h and the *.h file of a *.c file) * global linux headers * required local headers * extra forward declarations for pointers in function/struct declarations The only exceptions are linux/bitops.h and linux/if_ether.h in packet.h. This header file is shared with userspace applications like batctl and must therefore build together with userspace applications. The header linux/bitops.h is not part of the uapi headers and linux/if_ether.h conflicts with the musl implementation of netinet/if_ether.h. The maintainers rejected the use of __KERNEL__ preprocessor checks and thus these two headers are only in main.h. All files using packet.h first have to include main.h to work correctly. Reported-by: Markus Pargmann <mpa@pengutronix.de> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
2015-04-17 17:40:28 +00:00
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
#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 - 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 - 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_ */
Reference in New Issue Copy Permalink