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>
In C standard any expression different from 0 will be converted to
'true' when casting to bool (whatever is the length of the value).
Therefore all the "!!" conversions can be removed.
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
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@hundeboll.net>
Acked-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
The batadv_priv struct carries a pointer to its own interface
struct. Therefore, it is not necessary to retrieve the soft_iface
via the primary interface.
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
sctp_assoc_lookup_tsn() function searchs which transport a certain TSN
was sent on, if not found in the active_path transport, then go search
all the other transports in the peer's transport_addr_list, however, we
should continue to the next entry rather than break the loop when meet
the active_path transport.
Signed-off-by: Xufeng Zhang <xufeng.zhang@windriver.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When SCTP is done processing a duplicate cookie chunk, it tries
to delete a newly created association. For that, it has to set
the right association for the side-effect processing to work.
However, when it uses the SCTP_CMD_NEW_ASOC command, that performs
more work then really needed (like hashing the associationa and
assigning it an id) and there is no point to do that only to
delete the association as a next step. In fact, it also creates
an impossible condition where an association may be found by
the getsockopt() call, and that association is empty. This
causes a crash in some sctp getsockopts.
The solution is rather simple. We simply use SCTP_CMD_SET_ASOC
command that doesn't have all the overhead and does exactly
what we need.
Reported-by: Karl Heiss <kheiss@gmail.com>
Tested-by: Karl Heiss <kheiss@gmail.com>
CC: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
I had assumed that the only use of module aliases for filesystems
prior to "fs: Limit sys_mount to only request filesystem modules."
was in request_module. It turns out I was wrong. At least mkinitcpio
in Arch linux uses these aliases.
So readd the preexising aliases, to keep from breaking userspace.
Userspace eventually will have to follow and use the same aliases the
kernel does. So at some point we may be delete these aliases without
problems. However that day is not today.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Pull Ceph fix from Sage Weil:
"This fixes a bug in the new message decoding that just went in during
the last window."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
libceph: fix decoding of pgids
Pull nfsd bugfixes from Bruce Fields:
"Some minor fallout from the user-namespace work broke most krb5 mounts
to nfsd, and I screwed up a change to the AF_LOCAL rpc code."
* 'for-3.9' of git://linux-nfs.org/~bfields/linux:
sunrpc: don't attempt to cancel unitialized work
nfsd: fix krb5 handling of anonymous principals
[ Bug added added in commit 05e8ef4ab2 (net: factor out
skb_mac_gso_segment() from skb_gso_segment() ) ]
move vlan_depth out of while loop, or else vlan_depth always is ETH_HLEN,
can not be increased, and lead to infinite loop when frame has two vlan headers.
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is the second of the TLP patch series; it augments the basic TLP
algorithm with a loss detection scheme.
This patch implements a mechanism for loss detection when a Tail
loss probe retransmission plugs a hole thereby masking packet loss
from the sender. The loss detection algorithm relies on counting
TLP dupacks as outlined in Sec. 3 of:
http://tools.ietf.org/html/draft-dukkipati-tcpm-tcp-loss-probe-01
The basic idea is: Sender keeps track of TLP "episode" upon
retransmission of a TLP packet. An episode ends when the sender receives
an ACK above the SND.NXT (tracked by tlp_high_seq) at the time of the
episode. We want to make sure that before the episode ends the sender
receives a "TLP dupack", indicating that the TLP retransmission was
unnecessary, so there was no loss/hole that needed plugging. If the
sender gets no TLP dupack before the end of the episode, then it reduces
ssthresh and the congestion window, because the TLP packet arriving at
the receiver probably plugged a hole.
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch series implement the Tail loss probe (TLP) algorithm described
in http://tools.ietf.org/html/draft-dukkipati-tcpm-tcp-loss-probe-01. The
first patch implements the basic algorithm.
TLP's goal is to reduce tail latency of short transactions. It achieves
this by converting retransmission timeouts (RTOs) occuring due
to tail losses (losses at end of transactions) into fast recovery.
TLP transmits one packet in two round-trips when a connection is in
Open state and isn't receiving any ACKs. The transmitted packet, aka
loss probe, can be either new or a retransmission. When there is tail
loss, the ACK from a loss probe triggers FACK/early-retransmit based
fast recovery, thus avoiding a costly RTO. In the absence of loss,
there is no change in the connection state.
PTO stands for probe timeout. It is a timer event indicating
that an ACK is overdue and triggers a loss probe packet. The PTO value
is set to max(2*SRTT, 10ms) and is adjusted to account for delayed
ACK timer when there is only one oustanding packet.
TLP Algorithm
On transmission of new data in Open state:
-> packets_out > 1: schedule PTO in max(2*SRTT, 10ms).
-> packets_out == 1: schedule PTO in max(2*RTT, 1.5*RTT + 200ms)
-> PTO = min(PTO, RTO)
Conditions for scheduling PTO:
-> Connection is in Open state.
-> Connection is either cwnd limited or no new data to send.
-> Number of probes per tail loss episode is limited to one.
-> Connection is SACK enabled.
When PTO fires:
new_segment_exists:
-> transmit new segment.
-> packets_out++. cwnd remains same.
no_new_packet:
-> retransmit the last segment.
Its ACK triggers FACK or early retransmit based recovery.
ACK path:
-> rearm RTO at start of ACK processing.
-> reschedule PTO if need be.
In addition, the patch includes a small variation to the Early Retransmit
(ER) algorithm, such that ER and TLP together can in principle recover any
N-degree of tail loss through fast recovery. TLP is controlled by the same
sysctl as ER, tcp_early_retrans sysctl.
tcp_early_retrans==0; disables TLP and ER.
==1; enables RFC5827 ER.
==2; delayed ER.
==3; TLP and delayed ER. [DEFAULT]
==4; TLP only.
The TLP patch series have been extensively tested on Google Web servers.
It is most effective for short Web trasactions, where it reduced RTOs by 15%
and improved HTTP response time (average by 6%, 99th percentile by 10%).
The transmitted probes account for <0.5% of the overall transmissions.
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Using for_each_set_bit() to simplify the code.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Using for_each_set_bit_from() to simplify the code.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/intel/e1000e/netdev.c
Minor conflict in e1000e, a line that got fixed in 'net'
has been removed in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
The bridge multicast fast leave feature was added sufficient space
was not reserved in the netlink message. This means the flag may be
lost in netlink events and results of queries.
Found by observation while looking up some netlink stuff for discussion with Vlad.
Problem introduced by commit c2d3babfaf
Author: David S. Miller <davem@davemloft.net>
Date: Wed Dec 5 16:24:45 2012 -0500
bridge: implement multicast fast leave
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is needed in order to detect if the timestamp option appears
more than once in a packet, to remove the option if the packet is
fragmented, etc. My previous change neglected to store the option
location when the router addresses were prespecified and Pointer >
Length. But now the option location is also stored when Flag is an
unrecognized value, to ensure these option handling behaviors are
still performed.
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for L2 GRE tunnels, so that RPS can be more effective.
Signed-off-by: Michael Dalton <mwdalton@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
batadv_iv_ogm_process() accesses the packet using the tt_num_changes
attribute regardless of the real packet len (assuming the length check
was done before). Therefore a length check is needed to avoid reading
random memory.
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
In 4f6a7e5ee1 we effectively dropped support
for the legacy encoding for the OSDMap and incremental. However, we didn't
fix the decoding for the pgid.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Pull networking fixes from David Miller:
1) Missing cancel of work items in mac80211 MLME, from Ben Greear.
2) Fix DMA mapping handling in iwlwifi by using coherent DMA for
command headers, from Johannes Berg.
3) Decrease the amount of pressure on the page allocator by using order
1 pages less in iwlwifi, from Emmanuel Grumbach.
4) Fix mesh PS broadcast OOPS in mac80211, from Marco Porsch.
5) Don't forget to recalculate idle state in mac80211 monitor
interface, from Felix Fietkau.
6) Fix varargs in netfilter conntrack handler, from Joe Perches.
7) Need to reset entire chip when command queue fills up in iwlwifi,
from Emmanuel Grumbach.
8) The TX antenna value must be valid when calibrations are performed
in iwlwifi, fix from Dor Shaish.
9) Don't generate netfilter audit log entries when audit is disabled,
from Gao Feng.
10) Deal with DMA unit hang on e1000e during power state transitions,
from Bruce Allan.
11) Remove BUILD_BUG_ON check from igb driver, from Alexander Duyck.
12) Fix lockdep warning on i2c handling of igb driver, from Carolyn
Wyborny.
13) Fix several TTY handling issues in IRDA ircomm tty driver, from
Peter Hurley.
14) Several QFQ packet scheduler fixes from Paolo Valente.
15) When VXLAN encapsulates on transmit, we have to reset the netfilter
state. From Zang MingJie.
16) Fix jiffie check in net_rx_action() so that we really cap the
processing at 2HZ. From Eric Dumazet.
17) Fix erroneous trigger of IP option space exhaustion, when routers
are pre-specified and we are looking to see if we can insert a
timestamp, we will have the space. From David Ward.
18) Fix various issues in benet driver wrt waiting for firmware to
finish POST after resets or errors. From Gavin Shan and Sathya
Perla.
19) Fix TX locking in SFC driver, from Ben Hutchings.
20) Like the VXLAN fix above, when we encap in a TUN device we have to
reset the netfilter state. This should fix several strange crashes
reported by Dave Jones and others. From Eric Dumazet.
21) Don't forget to clean up MAC address resources when shutting down a
port in mlx4 driver, from Yan Burman.
22) Fix divide by zero in vmxnet3 driver, from Bhavesh Davda.
23) Fix device statistic regression in tg3 when the driver is using
phylib, from Nithin Sujir.
24) Fix info leak in several netlink handlers, from Mathias Krause.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (79 commits)
6lowpan: Fix endianness issue in is_addr_link_local().
rrunner.c: fix possible memory leak in rr_init_one()
dcbnl: fix various netlink info leaks
rtnl: fix info leak on RTM_GETLINK request for VF devices
bridge: fix mdb info leaks
tg3: Update link_up flag for phylib devices
ipv6: stop multicast forwarding to process interface scoped addresses
bridging: fix rx_handlers return code
netlabel: fix build problems when CONFIG_IPV6=n
drivers/isdn: checkng length to be sure not memory overflow
net/rds: zero last byte for strncpy
bnx2x: Fix SFP+ misconfiguration in iSCSI boot scenario
bnx2x: Fix intermittent long KR2 link up time
macvlan: Set IFF_UNICAST_FLT flag to prevent unnecessary promisc mode.
team: unsyc the devices addresses when port is removed
bridge: add missing vid to br_mdb_get()
Fix: sparse warning in inet_csk_prepare_forced_close
afkey: fix a typo
MAINTAINERS: Update qlcnic maintainers list
netlabel: correctly list all the static label mappings
...
Some devices have multicast filter capability for each individual
virtual interface rather than just a global one. Add an interface
specific driver callback allowing such drivers to configure this.
Signed-off-by: Alexander Bondar <alexander.bondar@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Instead of calling synchronize_net() for every key
on an interface or when a station is removed, do it
only once for all keys in both of these cases.
As a side-effect, removing station keys now always
calls synchronize_net() even if there are no keys,
which fixes an issue with station removal happening
in the driver while the station could still be used
for TX.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When a key is allocated but not really added, there's no
need to go through the entire teardown process. Also, if
adding a key fails, ieee80211_key_link() can take care of
freeing it instead of the (only) caller.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Replace printk(KERN_ERR with pr_err
Add space before {
Removed OOM messages
Signed-off-by: Valentin Ilie <valentin.ilie@gmail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a P2P Device interface receives an unhandled action
frame, we attempt to return it. This crashes because it
doesn't have a channel context. Fix the crash by using
status->band and properly mark the return frame as an
off-channel frame.
Reported-by: Ilan Peer <ilan.peer@intel.com>
Reviewed-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
If the remote LLC doesn't reply in time to our SNL requests we remove
them from the list of pending requests. The timeout is fixed to an
arbitrary value of 3 times remote_lto.
When not replied, the local LLC broadcasts NFC_EVENT_LLC_SDRES nl events for
the concerned uris with sap values set to LLCP_SDP_UNBOUND (which is 65).
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This adds a netlink interface for service name lookup support.
Multiple URIs can be passed nested into the NFC_ATTR_LLC_SDP attribute
using the NFC_CMD_LLC_SDREQ netlink command.
When the SNL reply is received, a NFC_EVENT_LLC_SDRES event is sent to
the user space. URI and SAP tuples are passed back, nested into
NFC_ATTR_LLC_SDP attribute.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This modifies the way SDRES PDUs are sent back. If multiple SDREQs are
received within a single SNL PDU, all SDRES replies are sent packed in
one SNL PDU too.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Some LLCP services (e.g. the validation ones) require some control over
the LLCP link parameters like the receive window (RW) or the MIU extension
(MIUX). This can only be done through socket options.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
They really are remote peer parameters, and we need to distinguish them
from the local ones as we'll modify the latter with socket options.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Similar to iptunnel_xmit(), group these operations into a
helper function.
This by the way fixes the missing u64_stats_update_begin()
and u64_stats_update_end() for 32 bit arch.
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
nla_data() cannot return NULL, so these NULL pointer checks are
superfluous.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The dcb netlink interface leaks stack memory in various places:
* perm_addr[] buffer is only filled at max with 12 of the 32 bytes but
copied completely,
* no in-kernel driver fills all fields of an IEEE 802.1Qaz subcommand,
so we're leaking up to 58 bytes for ieee_ets structs, up to 136 bytes
for ieee_pfc structs, etc.,
* the same is true for CEE -- no in-kernel driver fills the whole
struct,
Prevent all of the above stack info leaks by properly initializing the
buffers/structures involved.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initialize the mac address buffer with 0 as the driver specific function
will probably not fill the whole buffer. In fact, all in-kernel drivers
fill only ETH_ALEN of the MAX_ADDR_LEN bytes, i.e. 6 of the 32 possible
bytes. Therefore we currently leak 26 bytes of stack memory to userland
via the netlink interface.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The bridging code discloses heap and stack bytes via the RTM_GETMDB
netlink interface and via the notify messages send to group RTNLGRP_MDB
afer a successful add/del.
Fix both cases by initializing all unset members/padding bytes with
memset(0).
Cc: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With recent patches from Pravin, most tunnels can't use iptunnel_xmit()
any more, due to ip_select_ident() and skb->ip_summed. But we can just
move these operations out of iptunnel_xmit(), so that tunnels can
use it again.
This by the way fixes a bug in vxlan (missing nf_reset()) for net-next.
Cc: Pravin B Shelar <pshelar@nicira.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull namespace bugfixes from Eric Biederman:
"This is three simple fixes against 3.9-rc1. I have tested each of
these fixes and verified they work correctly.
The userns oops in key_change_session_keyring and the BUG_ON triggered
by proc_ns_follow_link were found by Dave Jones.
I am including the enhancement for mount to only trigger requests of
filesystem modules here instead of delaying this for the 3.10 merge
window because it is both trivial and the kind of change that tends to
bit-rot if left untouched for two months."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
proc: Use nd_jump_link in proc_ns_follow_link
fs: Limit sys_mount to only request filesystem modules (Part 2).
fs: Limit sys_mount to only request filesystem modules.
userns: Stop oopsing in key_change_session_keyring
Allow IPIP to make use of tx-checksum offloading.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tunnel_ip_select_ident() is more efficient when generating ip-header
id given inner packet is of ipv4 type.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add header with function definitions to quiet warnings and avoid future errors.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adds generic tunneling offloading support for IPv4-UDP based
tunnels.
GSO type is added to request this offload for a skb.
netdev feature NETIF_F_UDP_TUNNEL is added for hardware offloaded
udp-tunnel support. Currently no device supports this feature,
software offload is used.
This can be used by tunneling protocols like VXLAN.
CC: Jesse Gross <jesse@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds inner mac header. This will be used in next patch
to find tunner header length. Header len is required to copy tunnel
header to each gso segment.
This patch does not change any functionality.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
