Commit Graph

519184 Commits

Author SHA1 Message Date
Eric Dumazet
b396cca6fa net: sched: deprecate enqueue_root()
Only left enqueue_root() user is netem, and it looks not necessary :

qdisc_skb_cb(skb)->pkt_len is preserved after one skb_clone()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 14:17:32 -04:00
Michal Simek
3824246d37 net: ll_temac: Use one return statement instead of two
Use one return statement instead of two to simplify the code.
Both are returning the same value.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 14:16:18 -04:00
Philippe Reynes
db65f35f50 net: fec: add support of ethtool get_regs
This enables the ethtool's "-d" and "--register-dump"
options for fec devices.

Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 14:09:36 -04:00
Daniel Borkmann
4cda01e86f net: sched: fix typo in net_device ifdef
This should have been #ifdef not #if.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Fixes: d2788d3488 ("net: sched: further simplify handle_ing")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 13:37:42 -04:00
David S. Miller
3bb45001ac Merge branch 'handle_ing_lightweight'
Daniel Borkmann says:

====================
handle_ing update

These are a couple of cleanups to make ingress a bit more lightweight.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 11:10:35 -04:00
Daniel Borkmann
d2788d3488 net: sched: further simplify handle_ing
Ingress qdisc has no other purpose than calling into tc_classify()
that executes attached classifier(s) and action(s).

It has a 1:1 relationship to dev->ingress_queue. After having commit
087c1a601a ("net: sched: run ingress qdisc without locks") removed
the central ingress lock, one major contention point is gone.

The extra indirection layers however, are not necessary for calling
into ingress qdisc. pktgen calling locally into netif_receive_skb()
with a dummy u32, single CPU result on a Supermicro X10SLM-F, Xeon
E3-1240: before ~21,1 Mpps, after patch ~22,9 Mpps.

We can redirect the private classifier list to the netdev directly,
without changing any classifier API bits (!) and execute on that from
handle_ing() side. The __QDISC_STATE_DEACTIVATE test can be removed,
ingress qdisc doesn't have a queue and thus dev_deactivate_queue()
is also not applicable, ingress_cl_list provides similar behaviour.
In other words, ingress qdisc acts like TCQ_F_BUILTIN qdisc.

One next possible step is the removal of the dev's ingress (dummy)
netdev_queue, and to only have the list member in the netdevice
itself.

Note, the filter chain is RCU protected and individual filter elements
are being kfree'd by sched subsystem after RCU grace period. RCU read
lock is being held by __netif_receive_skb_core().

Joint work with Alexei Starovoitov.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 11:10:35 -04:00
Daniel Borkmann
c9e99fd078 net: sched: consolidate handle_ing and ing_filter
Given quite some code has been removed from ing_filter(), we can just
consolidate that function into handle_ing() and get rid of a few
instructions at the same time.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 11:10:34 -04:00
Xi Wang
986ccfdbd9 test: bpf: extend "load 64-bit immediate" testcase
Extend the testcase to catch a signedness bug in the arm64 JIT:

test_bpf: #58 load 64-bit immediate jited:1 ret -1 != 1 FAIL (1 times)

This is useful to ensure other JITs won't have a similar bug.

Link: https://lkml.org/lkml/2015/5/8/458
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 11:02:27 -04:00
David S. Miller
32f89e5c1a Merge branch 'bonding_netlink_lacp'
Jonathan Toppins says:

====================
add netlink support for new lacp bonding parameters

This is a resubmit of Mahesh's last 3 bonding patches from this series
(http://marc.info/?l=linux-netdev&m=142432864626179&w=2) with one
additional kernel patch which adds the netlink bits. I have noted any
modifications I did to the original patches just above my signoff line.
Patch 5 is the iproute2 support for these bonding options. All patches
were coded against the net-next branch of their respective projects.

v2:
  * rebased
  * only send these new parameters via netlink when bond is in mode 4
  * fixed ad_actor_sys_prio to be 0xFFFF by default even when the bond
    is initially created in mode 0 and switched to mode 4

v3:
  * reverted changes to bond_option_ad_actor_system_set() from v1 in Mahesh's
    patch "bonding: Allow userspace to set actors' macaddr in an AD-system."
    Instead implementing all setting in the option specific set function as
    Nik suggested.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 10:59:32 -04:00
Andy Gospodarek
171a42c38c bonding: add netlink support for sys prio, actor sys mac, and port key
Adds netlink support for the following bonding options:
* BOND_OPT_AD_ACTOR_SYS_PRIO
* BOND_OPT_AD_ACTOR_SYSTEM
* BOND_OPT_AD_USER_PORT_KEY

When setting the actor system mac address we assume the netlink message
contains a binary mac and not a string representation of a mac.

Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com>
[jt: completed the setting side of the netlink attributes]
Signed-off-by: Jonathan Toppins <jtoppins@cumulusnetworks.com>
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 10:59:32 -04:00
Mahesh Bandewar
d22a5fc0c3 bonding: Implement user key part of port_key in an AD system.
The port key has three components - user-key, speed-part, and duplex-part.
The LSBit is for the duplex-part, next 5 bits are for the speed while the
remaining 10 bits are the user defined key bits. Get these 10 bits
from the user-space (through the SysFs interface) and use it to form the
admin port-key. Allowed range for the user-key is 0 - 1023 (10 bits). If
it is not provided then use zero for the user-key-bits (default).

It can set using following example code -

   # modprobe bonding mode=4
   # usr_port_key=$(( RANDOM & 0x3FF ))
   # echo $usr_port_key > /sys/class/net/bond0/bonding/ad_user_port_key
   # echo +eth1 > /sys/class/net/bond0/bonding/slaves
   ...
   # ip link set bond0 up

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@redhat.com>
[jt: * fixed up style issues reported by checkpatch
     * fixed up context from change in ad_actor_sys_prio patch]
Signed-off-by: Jonathan Toppins <jtoppins@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 10:59:32 -04:00
Mahesh Bandewar
7451495755 bonding: Allow userspace to set actors' macaddr in an AD-system.
In an AD system, the communication between actor and partner is the
business between these two entities. In the current setup anyone on the
same L2 can "guess" the LACPDU contents and then possibly send the
spoofed LACPDUs and trick the partner causing connectivity issues for
the AD system. This patch allows to use a random mac-address obscuring
it's identity making it harder for someone in the L2 is do the same thing.

This patch allows user-space to choose the mac-address for the AD-system.
This mac-address can not be NULL or a Multicast. If the mac-address is set
from user-space; kernel will honor it and will not overwrite it. In the
absence (value from user space); the logic will default to using the
masters' mac as the mac-address for the AD-system.

It can be set using example code below -

   # modprobe bonding mode=4
   # sys_mac_addr=$(printf '%02x:%02x:%02x:%02x:%02x:%02x' \
                    $(( (RANDOM & 0xFE) | 0x02 )) \
                    $(( RANDOM & 0xFF )) \
                    $(( RANDOM & 0xFF )) \
                    $(( RANDOM & 0xFF )) \
                    $(( RANDOM & 0xFF )) \
                    $(( RANDOM & 0xFF )))
   # echo $sys_mac_addr > /sys/class/net/bond0/bonding/ad_actor_system
   # echo +eth1 > /sys/class/net/bond0/bonding/slaves
   ...
   # ip link set bond0 up

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@redhat.com>
[jt: fixed up style issues reported by checkpatch]
Signed-off-by: Jonathan Toppins <jtoppins@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 10:59:32 -04:00
Mahesh Bandewar
6791e4661c bonding: Allow userspace to set actors' system_priority in AD system
This patch allows user to randomize the system-priority in an ad-system.
The allowed range is 1 - 0xFFFF while default value is 0xFFFF. If user
does not specify this value, the system defaults to 0xFFFF, which is
what it was before this patch.

Following example code could set the value -
    # modprobe bonding mode=4
    # sys_prio=$(( 1 + RANDOM + RANDOM ))
    # echo $sys_prio > /sys/class/net/bond0/bonding/ad_actor_sys_prio
    # echo +eth1 > /sys/class/net/bond0/bonding/slaves
    ...
    # ip link set bond0 up

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@redhat.com>
[jt: * fixed up style issues reported by checkpatch
     * changed how the default value is set in bond_check_params(), this
       makes the default consistent between what gets set for a new bond
       and what the default is claimed to be in the bonding options.]
Signed-off-by: Jonathan Toppins <jtoppins@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 10:59:31 -04:00
David S. Miller
0198e09c4b Merge branch 'kernel_socket_netns'
Eric W. Biederman says:

====================
Cleanup the kernel sockets.

Right now the situtation for allocating kernel sockets is a mess.
- sock_create_kern does not take a namespace parameter.
- kernel sockets must not reference count a network namespace and keep
  it alive or else we will have a reference counting loop.
- The way we avoid the reference counting loop with sk_change_net
  and sk_release_kernel are major hacks.

This patchset addresses this mess by fixing sock_create_kern to do
everything necessary to create a kernel socket.  None of the current
users of kernel sockets need the network namespace reference counted.
Either kernel sockets are network namespace aware (and using the current
hacks) or kernel sockets are limited to the initial network namespace
in which case it does not matter.

This patchset starts by addressing tun which should be using normal
userspace sockets like macvtap.

Then sock_create_kern is fixed to take a network namespace.
Then the in kernel status of sockets are passed through to sk_alloc.
Then sk_alloc is fixed to not reference count the network namespace
     of kernel sockets.
Then the callers of sock_create_kern are fixed up to stop using hacks.
Then netlink which uses it's own flavor of sock_create_kern is fixed.

Finally the hacks that are sk_change_net and sk_release_kernel are removed.

When it is all done the code is easier to follow, easier to use, easier
to maintain and shorter by about 70 lines.
====================

Reported-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 10:50:19 -04:00
Eric W. Biederman
affb9792f1 net: kill sk_change_net and sk_release_kernel
These functions are no longer needed and no longer used kill them.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 10:50:18 -04:00
Eric W. Biederman
13d3078e22 netlink: Create kernel netlink sockets in the proper network namespace
Utilize the new functionality of sk_alloc so that nothing needs to be
done to suprress the reference counting on kernel sockets.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 10:50:18 -04:00
Eric W. Biederman
26abe14379 net: Modify sk_alloc to not reference count the netns of kernel sockets.
Now that sk_alloc knows when a kernel socket is being allocated modify
it to not reference count the network namespace of kernel sockets.

Keep track of if a socket needs reference counting by adding a flag to
struct sock called sk_net_refcnt.

Update all of the callers of sock_create_kern to stop using
sk_change_net and sk_release_kernel as those hacks are no longer
needed, to avoid reference counting a kernel socket.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 10:50:18 -04:00
Eric W. Biederman
11aa9c28b4 net: Pass kern from net_proto_family.create to sk_alloc
In preparation for changing how struct net is refcounted
on kernel sockets pass the knowledge that we are creating
a kernel socket from sock_create_kern through to sk_alloc.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 10:50:17 -04:00
Eric W. Biederman
eeb1bd5c40 net: Add a struct net parameter to sock_create_kern
This is long overdue, and is part of cleaning up how we allocate kernel
sockets that don't reference count struct net.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 10:50:17 -04:00
Eric W. Biederman
140e807da1 tun: Utilize the normal socket network namespace refcounting.
There is no need for tun to do the weird network namespace refcounting.
The existing network namespace refcounting in tfile has almost exactly
the same lifetime.  So rewrite the code to use the struct sock network
namespace refcounting and remove the unnecessary hand rolled network
namespace refcounting and the unncesary tfile->net.

This change allows the tun code to directly call sock_put bypassing
sock_release and making SOCK_EXTERNALLY_ALLOCATED unnecessary.

Remove the now unncessary tun_release so that if anything tries to use
the sock_release code path the kernel will oops, and let us know about
the bug.

The macvtap code already uses it's internal socket this way.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 10:50:16 -04:00
Eric Dumazet
80ba92fa1a codel: add ce_threshold attribute
For DCTCP or similar ECN based deployments on fabrics with shallow
buffers, hosts are responsible for a good part of the buffering.

This patch adds an optional ce_threshold to codel & fq_codel qdiscs,
so that DCTCP can have feedback from queuing in the host.

A DCTCP enabled egress port simply have a queue occupancy threshold
above which ECT packets get CE mark.

In codel language this translates to a sojourn time, so that one doesn't
have to worry about bytes or bandwidth but delays.

This makes the host an active participant in the health of the whole
network.

This also helps experimenting DCTCP in a setup without DCTCP compliant
fabric.

On following example, ce_threshold is set to 1ms, and we can see from
'ldelay xxx us' that TCP is not trying to go around the 5ms codel
target.

Queue has more capacity to absorb inelastic bursts (say from UDP
traffic), as queues are maintained to an optimal level.

lpaa23:~# ./tc -s -d qd sh dev eth1
qdisc mq 1: dev eth1 root
 Sent 87910654696 bytes 58065331 pkt (dropped 0, overlimits 0 requeues 42961)
 backlog 3108242b 364p requeues 42961
qdisc codel 8063: dev eth1 parent 1:1 limit 1000p target 5.0ms ce_threshold 1.0ms interval 100.0ms
 Sent 7363778701 bytes 4863809 pkt (dropped 0, overlimits 0 requeues 5503)
 rate 2348Mbit 193919pps backlog 255866b 46p requeues 5503
  count 0 lastcount 0 ldelay 1.0ms drop_next 0us
  maxpacket 68130 ecn_mark 0 drop_overlimit 0 ce_mark 72384
qdisc codel 8064: dev eth1 parent 1:2 limit 1000p target 5.0ms ce_threshold 1.0ms interval 100.0ms
 Sent 7636486190 bytes 5043942 pkt (dropped 0, overlimits 0 requeues 5186)
 rate 2319Mbit 191538pps backlog 207418b 64p requeues 5186
  count 0 lastcount 0 ldelay 694us drop_next 0us
  maxpacket 68130 ecn_mark 0 drop_overlimit 0 ce_mark 69873
qdisc codel 8065: dev eth1 parent 1:3 limit 1000p target 5.0ms ce_threshold 1.0ms interval 100.0ms
 Sent 11569360142 bytes 7641602 pkt (dropped 0, overlimits 0 requeues 5554)
 rate 3041Mbit 251096pps backlog 210446b 59p requeues 5554
  count 0 lastcount 0 ldelay 889us drop_next 0us
  maxpacket 68130 ecn_mark 0 drop_overlimit 0 ce_mark 37780
...

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Glenn Judd <glenn.judd@morganstanley.com>
Cc: Nandita Dukkipati <nanditad@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-10 19:50:20 -04:00
Varka Bhadram
cf9d0dcc5a ethernet: qualcomm: use spi instead of spi_device
All spi based drivers have an instance of struct spi_device
as spi. This patch renames spi_device to spi to synchronize
with all the drivers.

Signed-off-by: Varka Bhadram <varkab@cdac.in>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-10 17:52:54 -04:00
David S. Miller
3e3b34685a Merge branch 'pktgen-next'
Jesper Dangaard Brouer says:

====================
The following series introduce some pktgen changes

Patch01:
 Cleanup my own work when I introduced NO_TIMESTAMP.

Patch02:
 Took over patch from Alexei, and addressed my own concerns, as Alexie
 is too busy with other work, and this will provide an easy tool for
 measuring ingress path performance, which is a hot topic ATM.

 Changes were primarily user interface related.  Introduced a separate
 "xmit_mode" setting, instead of stealing one of the dev flags like
 Alexei did.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:26:06 -04:00
Alexei Starovoitov
62f64aed62 pktgen: introduce xmit_mode '<start_xmit|netif_receive>'
Introduce xmit_mode 'netif_receive' for pktgen which generates the
packets using familiar pktgen commands, but feeds them into
netif_receive_skb() instead of ndo_start_xmit().

Default mode is called 'start_xmit'.

It is designed to test netif_receive_skb and ingress qdisc
performace only. Make sure to understand how it works before
using it for other rx benchmarking.

Sample script 'pktgen.sh':
\#!/bin/bash
function pgset() {
  local result

  echo $1 > $PGDEV

  result=`cat $PGDEV | fgrep "Result: OK:"`
  if [ "$result" = "" ]; then
    cat $PGDEV | fgrep Result:
  fi
}

[ -z "$1" ] && echo "Usage: $0 DEV" && exit 1
ETH=$1

PGDEV=/proc/net/pktgen/kpktgend_0
pgset "rem_device_all"
pgset "add_device $ETH"

PGDEV=/proc/net/pktgen/$ETH
pgset "xmit_mode netif_receive"
pgset "pkt_size 60"
pgset "dst 198.18.0.1"
pgset "dst_mac 90:e2:ba:ff:ff:ff"
pgset "count 10000000"
pgset "burst 32"

PGDEV=/proc/net/pktgen/pgctrl
echo "Running... ctrl^C to stop"
pgset "start"
echo "Done"
cat /proc/net/pktgen/$ETH

Usage:
$ sudo ./pktgen.sh eth2
...
Result: OK: 232376(c232372+d3) usec, 10000000 (60byte,0frags)
  43033682pps 20656Mb/sec (20656167360bps) errors: 10000000

Raw netif_receive_skb speed should be ~43 million packet
per second on 3.7Ghz x86 and 'perf report' should look like:
  37.69%  kpktgend_0   [kernel.vmlinux]  [k] __netif_receive_skb_core
  25.81%  kpktgend_0   [kernel.vmlinux]  [k] kfree_skb
   7.22%  kpktgend_0   [kernel.vmlinux]  [k] ip_rcv
   5.68%  kpktgend_0   [pktgen]          [k] pktgen_thread_worker

If fib_table_lookup is seen on top, it means skb was processed
by the stack. To benchmark netif_receive_skb only make sure
that 'dst_mac' of your pktgen script is different from
receiving device mac and it will be dropped by ip_rcv

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:26:06 -04:00
Jesper Dangaard Brouer
f1f00d8ff6 pktgen: adjust flag NO_TIMESTAMP to be more pktgen compliant
Allow flag NO_TIMESTAMP to turn timestamping on again, like other flags,
with a negation of the flag like !NO_TIMESTAMP.

Also document the option flag NO_TIMESTAMP.

Fixes: afb84b6261 ("pktgen: add flag NO_TIMESTAMP to disable timestamping")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:26:06 -04:00
David S. Miller
4d95b72f61 Merge branch 'netns-scalability'
Nicolas Dichtel says:

====================
netns: ease netlink use with a lot of netns

This idea was informally discussed in Ottawa / netdev0.1. The goal is to
ease the use/scalability of netns, from a userland point of view.
Today, users need to open one netlink socket per family and per netns.
Thus, when the number of netns inscreases (for example 5K or more), the
number of sockets needed to manage them grows a lot.

The goal of this series is to be able to monitor netlink events, for a
specified family, for a set of netns, with only one netlink socket. For
this purpose, a netlink socket option is added: NETLINK_LISTEN_ALL_NSID.
When this option is set on a netlink socket, this socket will receive
netlink notifications from all netns that have a nsid assigned into the
netns where the socket has been opened.
The nsid is sent to userland via an anscillary data.

Here is an example with a patched iproute2. vxlan10 is created in the
current netns (netns0, nsid 0) and then moved to another netns (netns1,
nsid 1):

$ ip netns exec netns0 ip monitor all-nsid label
[nsid 0][NSID]nsid 1 (iproute2 netns name: netns1)
[nsid 0][NEIGH]??? lladdr 00:00:00:00:00:00 REACHABLE,PERMANENT
[nsid 0][LINK]5: vxlan10@NONE: <BROADCAST,MULTICAST> mtu 1450 qdisc noop state DOWN group default
    link/ether 92:33:17:e6:e7:1d brd ff:ff:ff:ff:ff:ff
[nsid 0][LINK]Deleted 5: vxlan10@NONE: <BROADCAST,MULTICAST> mtu 1450 qdisc noop state DOWN group default
    link/ether 92:33:17:e6:e7:1d brd ff:ff:ff:ff:ff:ff
[nsid 1][NSID]nsid 0 (iproute2 netns name: netns0)
[nsid 1][LINK]5: vxlan10@NONE: <BROADCAST,MULTICAST> mtu 1450 qdisc noop state DOWN group default
    link/ether 92:33:17:e6:e7:1d brd ff:ff:ff:ff:ff:ff link-netnsid 0
[nsid 1][ADDR]5: vxlan10    inet 192.168.0.249/24 brd 192.168.0.255 scope global vxlan10
       valid_lft forever preferred_lft forever
[nsid 1][ROUTE]local 192.168.0.249 dev vxlan10  table local  proto kernel  scope host  src 192.168.0.249
[nsid 1][ROUTE]ff00::/8 dev vxlan10  table local  metric 256  pref medium
[nsid 1][ROUTE]2001:123::/64 dev vxlan10  proto kernel  metric 256  pref medium
[nsid 1][LINK]5: vxlan10@NONE: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UNKNOWN group default
    link/ether 92:33:17:e6:e7:1d brd ff:ff:ff:ff:ff:ff link-netnsid 0
[nsid 1][ROUTE]broadcast 192.168.0.255 dev vxlan10  table local  proto kernel  scope link  src 192.168.0.249
[nsid 1][ROUTE]192.168.0.0/24 dev vxlan10  proto kernel  scope link  src 192.168.0.249
[nsid 1][ROUTE]broadcast 192.168.0.0 dev vxlan10  table local  proto kernel  scope link  src 192.168.0.249
[nsid 1][ROUTE]fe80::/64 dev vxlan10  proto kernel  metric 256  pref medium
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:15:31 -04:00
Nicolas Dichtel
59324cf35a netlink: allow to listen "all" netns
More accurately, listen all netns that have a nsid assigned into the netns
where the netlink socket is opened.
For this purpose, a netlink socket option is added:
NETLINK_LISTEN_ALL_NSID. When this option is set on a netlink socket, this
socket will receive netlink notifications from all netns that have a nsid
assigned into the netns where the socket has been opened. The nsid is sent
to userland via an anscillary data.

With this patch, a daemon needs only one socket to listen many netns. This
is useful when the number of netns is high.

Because 0 is a valid value for a nsid, the field nsid_is_set indicates if
the field nsid is valid or not. skb->cb is initialized to 0 on skb
allocation, thus we are sure that we will never send a nsid 0 by error to
the userland.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:15:31 -04:00
Nicolas Dichtel
cc3a572fe6 netlink: rename private flags and states
These flags and states have the same prefix (NETLINK_) that netlink socket
options. To avoid confusion and to be able to name a flag like a socket
option, let's use an other prefix: NETLINK_[S|F]_.

Note: a comment has been fixed, it was talking about
NETLINK_RECV_NO_ENOBUFS socket option instead of NETLINK_NO_ENOBUFS.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:15:31 -04:00
Nicolas Dichtel
95f38411df netns: use a spin_lock to protect nsid management
Before this patch, nsid were protected by the rtnl lock. The goal of this
patch is to be able to find a nsid without needing to hold the rtnl lock.

The next patch will introduce a netlink socket option to listen to all
netns that have a nsid assigned into the netns where the socket is opened.
Thus, it's important to call rtnl_net_notifyid() outside the spinlock, to
avoid a recursive lock (nsid are notified via rtnl). This was the main
reason of the previous patch.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:15:31 -04:00
Nicolas Dichtel
3138dbf881 netns: notify new nsid outside __peernet2id()
There is no functional change with this patch. It will ease the refactoring
of the locking system that protects nsids and the support of the netlink
socket option NETLINK_LISTEN_ALL_NSID.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:15:31 -04:00
Nicolas Dichtel
7a0877d4b4 netns: rename peernet2id() to peernet2id_alloc()
In a following commit, a new function will be introduced to only lookup for
a nsid (no allocation if the nsid doesn't exist). To avoid confusion, the
existing function is renamed.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:15:30 -04:00
Nicolas Dichtel
cab3c8ec8d netns: always provide the id to rtnl_net_fill()
The goal of this commit is to prepare the rework of the locking of nsnid
protection.
After this patch, rtnl_net_notifyid() will not call anymore __peernet2id(),
ie no idr_* operation into this function.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:15:30 -04:00
Nicolas Dichtel
109582af18 netns: returns always an id in __peernet2id()
All callers of this function expect a nsid, not an error.
Thus, returns NETNSA_NSID_NOT_ASSIGNED in case of error so that callers
don't have to convert the error to NETNSA_NSID_NOT_ASSIGNED.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:15:30 -04:00
David S. Miller
43996fdd9b linux-can-next-for-4.2-20150506
-----BEGIN PGP SIGNATURE-----
 
 iQIcBAABCgAGBQJVSoLGAAoJECte4hHFiupU6h0P/inQp/gltr5gqJ5iCscB5SMc
 wft/Fy9zIcZtxUSCdVIv1GQD1I4UbS9KLunXb/fXdeGrIKAZ6xP4X7TqherY58V6
 8b2MdxNG5cOlcldDq7ti9uMiR/ro4M5IVLnUHLOVZNW+eZ0jcXEIxwgrgeVs8ecq
 SSQPw3CfQQegYP492Iwq2vcljUpB5iZq4py1JVUQb+yACrPQTq/PBEXQ3ZFcn5nF
 plRaJgZYHs2cCHBQFW+g4xYmGkx3LlolQ4TVvtOQA1eUsn3v4xw7/KXb0HZEdvRZ
 oknrgA8hgS2U61UuEEW+9A4R8nwOiuEtlMo8BltyctYlNzlo+zdftSBJXNlewLxu
 sGSy1Zd4+mmYU5dVc3c+mZnDBQ4Rw7fuGZLIhUwp/hZY+wEiGMbFQ3+dc9kyMlP+
 rWhMr3vRihqBi2OrWrf8KraEuRmWwQzThT78PMtFFkKEz3HigFWKy61OUDHSjCsy
 a31BbaoKTMwZnIrnS30C5WeNUcY+CTxmibh/wVkeGsjI0knKcSgExkNXZp0dj12v
 sNspIVCs0MbCLDw72PPwjJ8SjDe4j7Mt9j1kSKCU8AaWh6gLMz2xmKvMIaICanJo
 2nDBYKxoLGRkJoHKxMW8G4g/6KIAGpQGQ17d6FArGc2GpxmxUUbwQxvQZDSGmnwn
 W+yTmBO2/89+ogIFOK8E
 =dcJu
 -----END PGP SIGNATURE-----

Merge tag 'linux-can-next-for-4.2-20150506' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2015-05-06

this is a pull request of a seven patches for net-next/master.

Andreas Gröger contributes two patches for the janz-ican3 driver. In
the first patch, the documentation for already existing sysfs entries
is added, the second patch adds support for another module/firmware
variant. A patch by Shawn Landden makes the padding in the struct
can_frame explicit. The next 4 patches target the flexcan driver, the
first one is by David Jander adding some documentation, the reaming
three by me add more documentation and two small code cleanups.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:12:17 -04:00
Harini Katakam
a5898ea09a net: macb: Add change_mtu callback with jumbo support
Add macb_change_mtu callback; if jumbo frame support is present allow
mtu size changes upto (jumbo max length allowed - headers).

Signed-off-by: Harini Katakam <harinik@xilinx.com>
Reviewed-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:41:54 -04:00
Harini Katakam
98b5a0f4a2 net: macb: Add support for jumbo frames
Enable jumbo frame support for Zynq Ultrascale+ MPSoC.
Update the NWCFG register and descriptor length masks accordingly.
Jumbo max length register should be set according to support in SoC; it is
set to 10240 for Zynq Ultrascale+ MPSoC.

Signed-off-by: Harini Katakam <harinik@xilinx.com>
Reviewed-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:41:54 -04:00
Harini Katakam
7b61f9c132 net: macb: Add compatible string for Zynq Ultrascale+ MPSoC
Add compatible string and config structure for Zynq Ultrascale+ MPSoC

Signed-off-by: Harini Katakam <harinik@xilinx.com>
Reviewed-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:41:53 -04:00
Harini Katakam
988d6f07fc devicetree: Add compatible string for Zynq Ultrascale+ MPSoC
Add "cdns,zynqmp-gem" to be used for Zynq Ultrascale+ MPSoC.

Signed-off-by: Harini Katakam <harinik@xilinx.com>
Reviewed-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:41:53 -04:00
Jason Baron
790ba4566c tcp: set SOCK_NOSPACE under memory pressure
Under tcp memory pressure, calling epoll_wait() in edge triggered
mode after -EAGAIN, can result in an indefinite hang in epoll_wait(),
even when there is sufficient memory available to continue making
progress. The problem is that when __sk_mem_schedule() returns 0
under memory pressure, we do not set the SOCK_NOSPACE flag in the
tcp write paths (tcp_sendmsg() or do_tcp_sendpages()). Then, since
SOCK_NOSPACE is used to trigger wakeups when incoming acks create
sufficient new space in the write queue, all outstanding packets
are acked, but we never wake up with the the EPOLLOUT that we are
expecting from epoll_wait().

This issue is currently limited to epoll() when used in edge trigger
mode, since 'tcp_poll()', does in fact currently set SOCK_NOSPACE.
This is sufficient for poll()/select() and epoll() in level trigger
mode. However, in edge trigger mode, epoll() is relying on the write
path to set SOCK_NOSPACE. EPOLL(7) says that in edge-trigger mode we
can only call epoll_wait() after read/write return -EAGAIN. Thus, in
the case of the socket write, we are relying on the fact that
tcp_sendmsg()/network write paths are going to issue a wakeup for
us at some point in the future when we get -EAGAIN.

Normally, epoll() edge trigger works fine when we've exceeded the
sk->sndbuf because in that case we do set SOCK_NOSPACE. However, when
we return -EAGAIN from the write path b/c we are over the tcp memory
limits and not b/c we are over the sndbuf, we are never going to get
another wakeup.

I can reproduce this issue, using SO_SNDBUF, since __sk_mem_schedule()
will return 0, or failure more readily with SO_SNDBUF:

1) create socket and set SO_SNDBUF to N
2) add socket as edge trigger
3) write to socket and block in epoll on -EAGAIN
4) cause tcp mem pressure via: echo "<small val>" > net.ipv4.tcp_mem

The fix here is simply to set SOCK_NOSPACE in sk_stream_wait_memory()
when the socket is non-blocking. Note that SOCK_NOSPACE, in addition
to waking up outstanding waiters is also used to expand the size of
the sk->sndbuf. However, we will not expand it by setting it in this
case because tcp_should_expand_sndbuf(), ensures that no expansion
occurs when we are under tcp memory pressure.

Note that we could still hang if sk->sk_wmem_queue is 0, when we get
the -EAGAIN. In this case the SOCK_NOSPACE bit will not help, since we
are waiting for and event that will never happen. I believe
that this case is harder to hit (and did not hit in my testing),
in that over the tcp 'soft' memory limits, we continue to guarantee a
minimum write buffer size. Perhaps, we could return -ENOSPC in this
case, or maybe we simply issue a wakeup in this case, such that we
keep retrying the write. Note that this case is not specific to
epoll() ET, but rather would affect blocking sockets as well. So I
view this patch as bringing epoll() edge-trigger into sync with the
current poll()/select()/epoll() level trigger and blocking sockets
behavior.

Signed-off-by: Jason Baron <jbaron@akamai.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:38:36 -04:00
Claudiu Manoil
3d23a05c75 gianfar: Enable changing mac addr when if up
Use device flag IFF_LIVE_ADDR_CHANGE to signal that
the device supports changing the hardware address when
the device is running.
This allows eth_mac_addr() to change the mac address
also when the network device's interface is open.
This capability is required by certain applications,
like bonding mode 6 (Adaptive Load Balancing).

Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:37:46 -04:00
Claudiu Manoil
bc60228087 gianfar: Move TxFIFO underrun handling to reset path
Handle TxFIFO underrun exceptions outside the fast path.
A controller reset is more reliable in this exceptional
case, as opposed to re-enabling on-the-fly the Tx DMA.

As the controller reset is handled outside the fast path
by the reset_gfar() workqueue handler, the locking
scheme on the Tx path is significantly simplified.
Because the Tx processing (xmit queues and tx napi) is
disabled during controller reset, tstat access from xmit
does not require locking.  So the scope of the txlock on
the processing path is now reduced to num_txbdfree, which
is shared only between process context (xmit) and softirq
(clean_tx_ring).  As a result, the txlock must not guard
against interrupt context, and the spin_lock_irqsave()
from xmit can be replaced by spin_lock_bh().  Likewise,
the locking has been downgraded for clean_tx_ring().

Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:37:46 -04:00
David S. Miller
39d726b76c Merge branch 'bpf_seccomp'
Daniel Borkmann says:

====================
BPF updates

This set gets rid of BPF special handling in seccomp filter preparation
and provides generic infrastructure from BPF side, which eventually also
allows for classic BPF JITs to add support for seccomp filters.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:35:05 -04:00
Daniel Borkmann
ac67eb2c53 seccomp, filter: add and use bpf_prog_create_from_user from seccomp
Seccomp has always been a special candidate when it comes to preparation
of its filters in seccomp_prepare_filter(). Due to the extra checks and
filter rewrite it partially duplicates code and has BPF internals exposed.

This patch adds a generic API inside the BPF code code that seccomp can use
and thus keep it's filter preparation code minimal and better maintainable.
The other side-effect is that now classic JITs can add seccomp support as
well by only providing a BPF_LDX | BPF_W | BPF_ABS translation.

Tested with seccomp and BPF test suites.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Nicolas Schichan <nschichan@freebox.fr>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:35:05 -04:00
Daniel Borkmann
658da9379d net: filter: add __GFP_NOWARN flag for larger kmem allocs
When seccomp BPF was added, it was discussed to add __GFP_NOWARN
flag for their configuration path as f.e. up to 32K allocations are
more prone to fail under stress. As we're going to reuse BPF API,
add __GFP_NOWARN flags where larger kmalloc() and friends allocations
could fail.

It doesn't make much sense to pass around __GFP_NOWARN everywhere as
an extra argument only for seccomp while we just as well could run
into similar issues for socket filters, where it's not desired to
have a user application throw a WARN() due to allocation failure.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Nicolas Schichan <nschichan@freebox.fr>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:35:05 -04:00
Nicolas Schichan
d9e12f42e5 seccomp: simplify seccomp_prepare_filter and reuse bpf_prepare_filter
Remove the calls to bpf_check_classic(), bpf_convert_filter() and
bpf_migrate_runtime() and let bpf_prepare_filter() take care of that
instead.

seccomp_check_filter() is passed to bpf_prepare_filter() so that it
gets called from there, after bpf_check_classic().

We can now remove exposure of two internal classic BPF functions
previously used by seccomp. The export of bpf_check_classic() symbol,
previously known as sk_chk_filter(), was there since pre git times,
and no in-tree module was using it, therefore remove it.

Joint work with Daniel Borkmann.

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:35:05 -04:00
Nicolas Schichan
4ae92bc77a net: filter: add a callback to allow classic post-verifier transformations
This is in preparation for use by the seccomp code, the rationale is
not to duplicate additional code within the seccomp layer, but instead,
have it abstracted and hidden within the classic BPF API.

As an interim step, this now also makes bpf_prepare_filter() visible
(not as exported symbol though), so that seccomp can reuse that code
path instead of reimplementing it.

Joint work with Daniel Borkmann.

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:35:05 -04:00
David S. Miller
0e00a0f73f Lots of updates for net-next for this cycle. As usual, we have
a lot of small fixes and cleanups, the bigger items are:
  * proper mac80211 rate control locking, to fix some random crashes
    (this required changing other locking as well)
  * mac80211 "fast-xmit", a mechanism to reduce, in most cases, the
    amount of code we execute while going from ndo_start_xmit() to
    the driver
  * this also clears the way for properly supporting S/G and checksum
    and segmentation offloads
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABCAAGBQJVSh65AAoJEDBSmw7B7bqrudwP/0iXyNQhF0mLTENrx+rdsDZS
 qQhB/8wejJaOJb89Re7M+bhwri7Q6S5BM/G24vhMc01dxmqNMcdKfEV3+nlmc5C+
 KeEgTI9aZiCnUt4WAd54Zwbkc9o+1kBtaFuaWDvOdQHUf0WDwEIQxjnV4+SZujV9
 xl1TV5yV35hRQgrDE8ZSbtOYRmhSVoi0MEgwqAjzdN2fEPyWVeqwYULDtpOopjL2
 UHQgv0E2fYVRWennHyQQ88tWBQg+EsRaG1U1/rYHhNBmAJ+f9AOxKi7ErzxYfkbM
 961B+3E++pM+zUeqw6+jaMKqT5jeCCM5ugCNSG4NrIvfxDIDgecAFV9Fs2islnI4
 8xd3GqyA5iqaitAWIUsaYaQfaAcwSIlpSinfQW9EUm2wuCkPyZboFP+GRd2K7sQn
 FnRJSJ9PkGPdWwdDE3gunLHBHtbDS0z+R8VegIeS0qT8LamkqICiNQSyPlsTeluW
 ig2kwHsDdj3k11wyelhfp/RdtsOch/brKpLSjdzPXC1BzIWhQLwmsPh9qZ83vSB9
 qbLsdnM/IPQXocWB6fOhmwaGsLeRalxs2yQFM0zdJCwpaU9dzKsJrxepAXVuq31p
 r0fygWTp8GVevHXzfS7fRya8xjsTRrSs6n2kH7ErOfiep13HQypAjbyLswNe4kW/
 D6x8pVC3AhdGkl/9CW4m
 =oUlh
 -----END PGP SIGNATURE-----

Merge tag 'mac80211-next-for-davem-2015-05-06' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next

Johannes Berg says:

====================
Lots of updates for net-next for this cycle. As usual, we have
a lot of small fixes and cleanups, the bigger items are:
 * proper mac80211 rate control locking, to fix some random crashes
   (this required changing other locking as well)
 * mac80211 "fast-xmit", a mechanism to reduce, in most cases, the
   amount of code we execute while going from ndo_start_xmit() to
   the driver
 * this also clears the way for properly supporting S/G and checksum
   and segmentation offloads
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:27:25 -04:00
David S. Miller
82ae9c6060 Merge branch 'tcp-more-reliable-window-probes'
Eric Dumazet says:

====================
tcp: more reliable window probes

This series address a problem caused by small rto_min timers in DC,
leading to either timer storms or early flow terminations.

We also add two new SNMP counters for proper monitoring :
TCPWinProbe and TCPKeepAlive

v2: added TCPKeepAlive counter, as suggested by Yuchung & Neal
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 16:42:32 -04:00
Eric Dumazet
e520af48c7 tcp: add TCPWinProbe and TCPKeepAlive SNMP counters
Diagnosing problems related to Window Probes has been hard because
we lack a counter.

TCPWinProbe counts the number of ACK packets a sender has to send
at regular intervals to make sure a reverse ACK packet opening back
a window had not been lost.

TCPKeepAlive counts the number of ACK packets sent to keep TCP
flows alive (SO_KEEPALIVE)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 16:42:32 -04:00
Eric Dumazet
21c8fe9915 tcp: adjust window probe timers to safer values
With the advent of small rto timers in datacenter TCP,
(ip route ... rto_min x), the following can happen :

1) Qdisc is full, transmit fails.

   TCP sets a timer based on icsk_rto to retry the transmit, without
   exponential backoff.
   With low icsk_rto, and lot of sockets, all cpus are servicing timer
   interrupts like crazy.
   Intent of the code was to retry with a timer between 200 (TCP_RTO_MIN)
   and 500ms (TCP_RESOURCE_PROBE_INTERVAL)

2) Receivers can send zero windows if they don't drain their receive queue.

   TCP sends zero window probes, based on icsk_rto current value, with
   exponential backoff.
   With /proc/sys/net/ipv4/tcp_retries2 being 15 (or even smaller in
   some cases), sender can abort in less than one or two minutes !
   If receiver stops the sender, it obviously doesn't care of very tight
   rto. Probability of dropping the ACK reopening the window is not
   worth the risk.

Lets change the base timer to be at least 200ms (TCP_RTO_MIN) for these
events (but not normal RTO based retransmits)

A followup patch adds a new SNMP counter, as it would have helped a lot
diagnosing this issue.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 16:42:32 -04:00