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path: root/net/batman-adv/network-coding.h
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2015-06-07batman-adv: Add required includes to all filesSven Eckelmann
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>
2015-05-29batman-adv: update copyright years for 2015Sven Eckelmann
Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
2014-01-12batman-adv: update copyright years for 2014Simon Wunderlich
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2014-01-12batman-adv: remove returns at the end of void functionsAntonio Quartulli
Return at the end of void functions is not needed. Since most of the void functions in the code do not do so, make all the others consistent by removing the useless returns. Actually all the functions to be "fixed" are in network-coding.h only. Signed-off-by: Antonio Quartulli <antonio@meshcoding.com> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
2014-01-08batman-adv: remove FSF address from GPL disclaimerAntonio Quartulli
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>
2013-10-09batman-adv: tvlv - add network coding containerMarek Lindner
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>
2013-10-02batman-adv: set up network coding packet handlers during module initMatthias Schiffer
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>
2013-05-29batman-adv: Move call to batadv_nc_skb_forward() from routing.c to send.cMartin Hundebøll
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>
2013-03-13batman-adv: network coding - save overheard and tx packets for decodingMartin Hundebøll
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>
2013-03-13batman-adv: network coding - buffer unicast packets before forwardMartin Hundebøll
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>
2013-03-13batman-adv: network coding - detect coding nodes and remove these after timeoutMartin Hundebøll
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>
2013-03-13batman-adv: network coding - add the initial infrastructure codeMartin Hundebøll
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>