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  1. 04 6月, 2015 2 次提交
  3. 28 5月, 2015 1 次提交
    • E
      tcp/dccp: try to not exhaust ip_local_port_range in connect() · 07f4c900
      由 Eric Dumazet 提交于 
      A long standing problem on busy servers is the tiny available TCP port
range (/proc/sys/net/ipv4/ip_local_port_range) and the default
sequential allocation of source ports in connect() system call.

If a host is having a lot of active TCP sessions, chances are
very high that all ports are in use by at least one flow,
and subsequent bind(0) attempts fail, or have to scan a big portion of
space to find a slot.

In this patch, I changed the starting point in __inet_hash_connect()
so that we try to favor even [1] ports, leaving odd ports for bind()
users.

We still perform a sequential search, so there is no guarantee, but
if connect() targets are very different, end result is we leave
more ports available to bind(), and we spread them all over the range,
lowering time for both connect() and bind() to find a slot.

This strategy only works well if /proc/sys/net/ipv4/ip_local_port_range
is even, ie if start/end values have different parity.

Therefore, default /proc/sys/net/ipv4/ip_local_port_range was changed to
32768 - 60999 (instead of 32768 - 61000)

There is no change on security aspects here, only some poor hashing
schemes could be eventually impacted by this change.

[1] : The odd/even property depends on ip_local_port_range values parity
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      07f4c900
  5. 27 5月, 2015 1 次提交
  7. 23 5月, 2015 5 次提交
  9. 20 5月, 2015 1 次提交
    • D
      tcp: add rfc3168, section 6.1.1.1. fallback · 49213555
      由 Daniel Borkmann 提交于 
      This work as a follow-up of commit f7b3bec6 ("net: allow setting ecn
via routing table") and adds RFC3168 section 6.1.1.1. fallback for outgoing
ECN connections. In other words, this work adds a retry with a non-ECN
setup SYN packet, as suggested from the RFC on the first timeout:

  [...] A host that receives no reply to an ECN-setup SYN within the
  normal SYN retransmission timeout interval MAY resend the SYN and
  any subsequent SYN retransmissions with CWR and ECE cleared. [...]

Schematic client-side view when assuming the server is in tcp_ecn=2 mode,
that is, Linux default since 2009 via commit 255cac91 ("tcp: extend
ECN sysctl to allow server-side only ECN"):

 1) Normal ECN-capable path:

    SYN ECE CWR ----->
                <----- SYN ACK ECE
            ACK ----->

 2) Path with broken middlebox, when client has fallback:

    SYN ECE CWR ----X crappy middlebox drops packet
                      (timeout, rtx)
            SYN ----->
                <----- SYN ACK
            ACK ----->

In case we would not have the fallback implemented, the middlebox drop
point would basically end up as:

    SYN ECE CWR ----X crappy middlebox drops packet
                      (timeout, rtx)
    SYN ECE CWR ----X crappy middlebox drops packet
                      (timeout, rtx)
    SYN ECE CWR ----X crappy middlebox drops packet
                      (timeout, rtx)

In any case, it's rather a smaller percentage of sites where there would
occur such additional setup latency: it was found in end of 2014 that ~56%
of IPv4 and 65% of IPv6 servers of Alexa 1 million list would negotiate
ECN (aka tcp_ecn=2 default), 0.42% of these webservers will fail to connect
when trying to negotiate with ECN (tcp_ecn=1) due to timeouts, which the
fallback would mitigate with a slight latency trade-off. Recent related
paper on this topic:

  Brian Trammell, Mirja Kühlewind, Damiano Boppart, Iain Learmonth,
  Gorry Fairhurst, and Richard Scheffenegger:
    "Enabling Internet-Wide Deployment of Explicit Congestion Notification."
    Proc. PAM 2015, New York.
  http://ecn.ethz.ch/ecn-pam15.pdf

Thus, when net.ipv4.tcp_ecn=1 is being set, the patch will perform RFC3168,
section 6.1.1.1. fallback on timeout. For users explicitly not wanting this
which can be in DC use case, we add a net.ipv4.tcp_ecn_fallback knob that
allows for disabling the fallback.

tp->ecn_flags are not being cleared in tcp_ecn_clear_syn() on output, but
rather we let tcp_ecn_rcv_synack() take that over on input path in case a
SYN ACK ECE was delayed. Thus a spurious SYN retransmission will not prevent
ECN being negotiated eventually in that case.

Reference: https://www.ietf.org/proceedings/92/slides/slides-92-iccrg-1.pdf
Reference: https://www.ietf.org/proceedings/89/slides/slides-89-tsvarea-1.pdfSigned-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NMirja Kühlewind <mirja.kuehlewind@tik.ee.ethz.ch>
Signed-off-by: NBrian Trammell <trammell@tik.ee.ethz.ch>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Dave That <dave.taht@gmail.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      49213555
  11. 14 5月, 2015 2 次提交
  13. 13 5月, 2015 1 次提交
  15. 11 5月, 2015 3 次提交
    • M
      bonding: Implement user key part of port_key in an AD system. · d22a5fc0
      由 Mahesh Bandewar 提交于 
      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: NMahesh Bandewar <maheshb@google.com>
Reviewed-by: NNikolay 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: NJonathan Toppins <jtoppins@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d22a5fc0
    • M
      bonding: Allow userspace to set actors' macaddr in an AD-system. · 74514957
      由 Mahesh Bandewar 提交于 
      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: NMahesh Bandewar <maheshb@google.com>
Reviewed-by: NNikolay Aleksandrov <nikolay@redhat.com>
[jt: fixed up style issues reported by checkpatch]
Signed-off-by: NJonathan Toppins <jtoppins@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      74514957
    • M
      bonding: Allow userspace to set actors' system_priority in AD system · 6791e466
      由 Mahesh Bandewar 提交于 
      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: NMahesh Bandewar <maheshb@google.com>
Reviewed-by: NNikolay 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: NJonathan Toppins <jtoppins@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6791e466
  17. 10 5月, 2015 2 次提交
    • A
      pktgen: introduce xmit_mode '<start_xmit|netif_receive>' · 62f64aed
      由 Alexei Starovoitov 提交于 
      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: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      62f64aed
    • J
      pktgen: adjust flag NO_TIMESTAMP to be more pktgen compliant · f1f00d8f
      由 Jesper Dangaard Brouer 提交于 
      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: afb84b62 ("pktgen: add flag NO_TIMESTAMP to disable timestamping")
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f1f00d8f
  19. 06 5月, 2015 1 次提交
  21. 04 5月, 2015 1 次提交
    • T
      ipv6: Flow label state ranges · 82a584b7
      由 Tom Herbert 提交于 
      This patch divides the IPv6 flow label space into two ranges:
0-7ffff is reserved for flow label manager, 80000-fffff will be
used for creating auto flow labels (per RFC6438). This only affects how
labels are set on transmit, it does not affect receive. This range split
can be disbaled by systcl.

Background:

IPv6 flow labels have been an unmitigated disappointment thus far
in the lifetime of IPv6. Support in HW devices to use them for ECMP
is lacking, and OSes don't turn them on by default. If we had these
we could get much better hashing in IPv6 networks without resorting
to DPI, possibly eliminating some of the motivations to to define new
encaps in UDP just for getting ECMP.

Unfortunately, the initial specfications of IPv6 did not clarify
how they are to be used. There has always been a vague concept that
these can be used for ECMP, flow hashing, etc. and we do now have a
good standard how to this in RFC6438. The problem is that flow labels
can be either stateful or stateless (as in RFC6438), and we are
presented with the possibility that a stateless label may collide
with a stateful one.  Attempts to split the flow label space were
rejected in IETF. When we added support in Linux for RFC6438, we
could not turn on flow labels by default due to this conflict.

This patch splits the flow label space and should give us
a path to enabling auto flow labels by default for all IPv6 packets.
This is an API change so we need to consider compatibility with
existing deployment. The stateful range is chosen to be the lower
values in hopes that most uses would have chosen small numbers.

Once we resolve the stateless/stateful issue, we can proceed to
look at enabling RFC6438 flow labels by default (starting with
scaled testing).
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      82a584b7
  23. 03 5月, 2015 1 次提交
  25. 27 4月, 2015 1 次提交
    • E
      net: rfs: fix crash in get_rps_cpus() · a31196b0
      由 Eric Dumazet 提交于 
      Commit 567e4b79 ("net: rfs: add hash collision detection") had one
mistake :

RPS_NO_CPU is no longer the marker for invalid cpu in set_rps_cpu()
and get_rps_cpu(), as @next_cpu was the result of an AND with
rps_cpu_mask

This bug showed up on a host with 72 cpus :
next_cpu was 0x7f, and the code was trying to access percpu data of an
non existent cpu.

In a follow up patch, we might get rid of compares against nr_cpu_ids,
if we init the tables with 0. This is silly to test for a very unlikely
condition that exists only shortly after table initialization, as
we got rid of rps_reset_sock_flow() and similar functions that were
writing this RPS_NO_CPU magic value at flow dismantle : When table is
old enough, it never contains this value anymore.

Fixes: 567e4b79 ("net: rfs: add hash collision detection")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a31196b0
  27. 23 4月, 2015 1 次提交
    • R
      mpls: Per-device enabling of packet input · 37bde799
      由 Robert Shearman 提交于 
      An MPLS network is a single trust domain where the edges must be in
control of what labels make their way into the core. The simplest way
of ensuring this is for the edge device to always impose the labels,
and not allow forward labeled traffic from untrusted neighbours. This
is achieved by allowing a per-device configuration of whether MPLS
traffic input from that interface should be processed or not.

To be secure by default, the default state is changed to MPLS being
disabled on all interfaces unless explicitly enabled and no global
option is provided to change the default. Whilst this differs from
other protocols (e.g. IPv6), network operators are used to explicitly
enabling MPLS forwarding on interfaces, and with the number of links
to the MPLS core typically fairly low this doesn't present too much of
a burden on operators.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NRobert Shearman <rshearma@brocade.com>
Reviewed-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      37bde799
  29. 10 4月, 2015 3 次提交
  31. 09 4月, 2015 1 次提交
  33. 01 4月, 2015 1 次提交
    • O
      can: introduce new raw socket option to join the given CAN filters · a5581ef4
      由 Oliver Hartkopp 提交于 
      The CAN_RAW socket can set multiple CAN identifier specific filters that lead
to multiple filters in the af_can.c filter processing. These filters are
indenpendent from each other which leads to logical OR'ed filters when applied.

This socket option joines the given CAN filters in the way that only CAN frames
are passed to user space that matched *all* given CAN filters. The semantic for
the applied filters is therefore changed to a logical AND.

This is useful especially when the filterset is a combination of filters where
the CAN_INV_FILTER flag is set in order to notch single CAN IDs or CAN ID
ranges from the incoming traffic.

As the raw_rcv() function is executed from NET_RX softirq the introduced
variables are implemented as per-CPU variables to avoid extensive locking at
CAN frame reception time.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>
      a5581ef4
  35. 25 3月, 2015 1 次提交
  37. 24 3月, 2015 2 次提交
  39. 21 3月, 2015 1 次提交
  41. 19 3月, 2015 1 次提交
  43. 09 3月, 2015 1 次提交
  45. 07 3月, 2015 1 次提交
  47. 04 3月, 2015 1 次提交
  49. 25 2月, 2015 1 次提交
  51. 24 2月, 2015 3 次提交