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  1. 02 10月, 2017 4 次提交
  3. 01 8月, 2017 1 次提交
  5. 16 6月, 2017 1 次提交
    • D
      tcp: ULP infrastructure · 734942cc
      由 Dave Watson 提交于 
      Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP
sockets. Based on a similar infrastructure in tcp_cong.  The idea is that any
ULP can add its own logic by changing the TCP proto_ops structure to its own
methods.

Example usage:

setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls"));

modules will call:
tcp_register_ulp(&tcp_tls_ulp_ops);

to register/unregister their ulp, with an init function and name.

A list of registered ulps will be returned by tcp_get_available_ulp, which is
hooked up to /proc.  Example:

$ cat /proc/sys/net/ipv4/tcp_available_ulp
tls

There is currently no functionality to remove or chain ULPs, but
it should be possible to add these in the future if needed.
Signed-off-by: NBoris Pismenny <borisp@mellanox.com>
Signed-off-by: NDave Watson <davejwatson@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      734942cc
  7. 08 6月, 2017 3 次提交
  9. 25 4月, 2017 2 次提交
    • W
      net/tcp_fastopen: Disable active side TFO in certain scenarios · cf1ef3f0
      由 Wei Wang 提交于 
      Middlebox firewall issues can potentially cause server's data being
blackholed after a successful 3WHS using TFO. Following are the related
reports from Apple:
https://www.nanog.org/sites/default/files/Paasch_Network_Support.pdf
Slide 31 identifies an issue where the client ACK to the server's data
sent during a TFO'd handshake is dropped.
C ---> syn-data ---> S
C <--- syn/ack ----- S
C (accept & write)
C <---- data ------- S
C ----- ACK -> X     S
		[retry and timeout]

https://www.ietf.org/proceedings/94/slides/slides-94-tcpm-13.pdf
Slide 5 shows a similar situation that the server's data gets dropped
after 3WHS.
C ---- syn-data ---> S
C <--- syn/ack ----- S
C ---- ack --------> S
S (accept & write)
C?  X <- data ------ S
		[retry and timeout]

This is the worst failure b/c the client can not detect such behavior to
mitigate the situation (such as disabling TFO). Failing to proceed, the
application (e.g., SSL library) may simply timeout and retry with TFO
again, and the process repeats indefinitely.

The proposed solution is to disable active TFO globally under the
following circumstances:
1. client side TFO socket detects out of order FIN
2. client side TFO socket receives out of order RST

We disable active side TFO globally for 1hr at first. Then if it
happens again, we disable it for 2h, then 4h, 8h, ...
And we reset the timeout to 1hr if a client side TFO sockets not opened
on loopback has successfully received data segs from server.
And we examine this condition during close().

The rational behind it is that when such firewall issue happens,
application running on the client should eventually close the socket as
it is not able to get the data it is expecting. Or application running
on the server should close the socket as it is not able to receive any
response from client.
In both cases, out of order FIN or RST will get received on the client
given that the firewall will not block them as no data are in those
frames.
And we want to disable active TFO globally as it helps if the middle box
is very close to the client and most of the connections are likely to
fail.

Also, add a debug sysctl:
  tcp_fastopen_blackhole_detect_timeout_sec:
    the initial timeout to use when firewall blackhole issue happens.
    This can be set and read.
    When setting it to 0, it means to disable the active disable logic.
Signed-off-by: NWei Wang <weiwan@google.com>
Acked-by: NYuchung Cheng <ycheng@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      cf1ef3f0
    • D
      net: add rcu locking when changing early demux · 58c4c6a3
      由 David Ahern 提交于 
      systemd-sysctl is triggering a suspicious RCU usage message when
net.ipv4.tcp_early_demux or net.ipv4.udp_early_demux is changed via
a sysctl config file:

[   33.896184] ===============================
[   33.899558] [ ERR: suspicious RCU usage.  ]
[   33.900624] 4.11.0-rc7+ #104 Not tainted
[   33.901698] -------------------------------
[   33.903059] /home/dsa/kernel-2.git/net/ipv4/sysctl_net_ipv4.c:305 suspicious rcu_dereference_check() usage!
[   33.905724]
other info that might help us debug this:

[   33.907656]
rcu_scheduler_active = 2, debug_locks = 0
[   33.909288] 1 lock held by systemd-sysctl/143:
[   33.910373]  #0:  (sb_writers#5){.+.+.+}, at: [<ffffffff8123a370>] file_start_write+0x45/0x48
[   33.912407]
stack backtrace:
[   33.914018] CPU: 0 PID: 143 Comm: systemd-sysctl Not tainted 4.11.0-rc7+ #104
[   33.915631] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[   33.917870] Call Trace:
[   33.918431]  dump_stack+0x81/0xb6
[   33.919241]  lockdep_rcu_suspicious+0x10f/0x118
[   33.920263]  proc_configure_early_demux+0x65/0x10a
[   33.921391]  proc_udp_early_demux+0x3a/0x41

add rcu locking to proc_configure_early_demux.

Fixes: dddb64bc ("net: Add sysctl to toggle early demux for tcp and udp")
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      58c4c6a3
  11. 25 3月, 2017 1 次提交
    • S
      net: Add sysctl to toggle early demux for tcp and udp · dddb64bc
      由 subashab@codeaurora.org 提交于 
      Certain system process significant unconnected UDP workload.
It would be preferrable to disable UDP early demux for those systems
and enable it for TCP only.

By disabling UDP demux, we see these slight gains on an ARM64 system-
782 -> 788Mbps unconnected single stream UDPv4
633 -> 654Mbps unconnected UDPv4 different sources

The performance impact can change based on CPU architecure and cache
sizes. There will not much difference seen if entire UDP hash table
is in cache.

Both sysctls are enabled by default to preserve existing behavior.

v1->v2: Change function pointer instead of adding conditional as
suggested by Stephen.

v2->v3: Read once in callers to avoid issues due to compiler
optimizations. Also update commit message with the tests.

v3->v4: Store and use read once result instead of querying pointer
again incorrectly.

v4->v5: Refactor to avoid errors due to compilation with IPV6={m,n}
Signed-off-by: NSubash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Suggested-by: NEric Dumazet <edumazet@google.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Tom Herbert <tom@herbertland.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      dddb64bc
  13. 22 3月, 2017 1 次提交
    • N
      net: ipv4: add support for ECMP hash policy choice · bf4e0a3d
      由 Nikolay Aleksandrov 提交于 
      This patch adds support for ECMP hash policy choice via a new sysctl
called fib_multipath_hash_policy and also adds support for L4 hashes.
The current values for fib_multipath_hash_policy are:
 0 - layer 3 (default)
 1 - layer 4
If there's an skb hash already set and it matches the chosen policy then it
will be used instead of being calculated (currently only for L4).
In L3 mode we always calculate the hash due to the ICMP error special
case, the flow dissector's field consistentification should handle the
address order thus we can remove the address reversals.
If the skb is provided we always use it for the hash calculation,
otherwise we fallback to fl4, that is if skb is NULL fl4 has to be set.
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      bf4e0a3d
  15. 17 3月, 2017 1 次提交
    • S
      tcp: remove tcp_tw_recycle · 4396e461
      由 Soheil Hassas Yeganeh 提交于 
      The tcp_tw_recycle was already broken for connections
behind NAT, since the per-destination timestamp is not
monotonically increasing for multiple machines behind
a single destination address.

After the randomization of TCP timestamp offsets
in commit 8a5bd45f6616 (tcp: randomize tcp timestamp offsets
for each connection), the tcp_tw_recycle is broken for all
types of connections for the same reason: the timestamps
received from a single machine is not monotonically increasing,
anymore.

Remove tcp_tw_recycle, since it is not functional. Also, remove
the PAWSPassive SNMP counter since it is only used for
tcp_tw_recycle, and simplify tcp_v4_route_req and tcp_v6_route_req
since the strict argument is only set when tcp_tw_recycle is
enabled.
Signed-off-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Cc: Lutz Vieweg <lvml@5t9.de>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4396e461
  17. 31 1月, 2017 1 次提交
    • R
      net: Avoid receiving packets with an l3mdev on unbound UDP sockets · 63a6fff3
      由 Robert Shearman 提交于 
      Packets arriving in a VRF currently are delivered to UDP sockets that
aren't bound to any interface. TCP defaults to not delivering packets
arriving in a VRF to unbound sockets. IP route lookup and socket
transmit both assume that unbound means using the default table and
UDP applications that haven't been changed to be aware of VRFs may not
function correctly in this case since they may not be able to handle
overlapping IP address ranges, or be able to send packets back to the
original sender if required.

So add a sysctl, udp_l3mdev_accept, to control this behaviour with it
being analgous to the existing tcp_l3mdev_accept, namely to allow a
process to have a VRF-global listen socket. Have this default to off
as this is the behaviour that users will expect, given that there is
no explicit mechanism to set unmodified VRF-unaware application into a
default VRF.
Signed-off-by: NRobert Shearman <rshearma@brocade.com>
Acked-by: NDavid Ahern <dsa@cumulusnetworks.com>
Tested-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      63a6fff3
  19. 25 1月, 2017 1 次提交
    • K
      Introduce a sysctl that modifies the value of PROT_SOCK. · 4548b683
      由 Krister Johansen 提交于 
      Add net.ipv4.ip_unprivileged_port_start, which is a per namespace sysctl
that denotes the first unprivileged inet port in the namespace.  To
disable all privileged ports set this to zero.  It also checks for
overlap with the local port range.  The privileged and local range may
not overlap.

The use case for this change is to allow containerized processes to bind
to priviliged ports, but prevent them from ever being allowed to modify
their container's network configuration.  The latter is accomplished by
ensuring that the network namespace is not a child of the user
namespace.  This modification was needed to allow the container manager
to disable a namespace's priviliged port restrictions without exposing
control of the network namespace to processes in the user namespace.
Signed-off-by: NKrister Johansen <kjlx@templeofstupid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4548b683
  21. 14 1月, 2017 1 次提交
    • Y
      tcp: remove thin_dupack feature · 4a7f6009
      由 Yuchung Cheng 提交于 
      Thin stream DUPACK is to start fast recovery on only one DUPACK
provided the connection is a thin stream (i.e., low inflight).  But
this older feature is now subsumed with RACK. If a connection
receives only a single DUPACK, RACK would arm a reordering timer
and soon starts fast recovery instead of timeout if no further
ACKs are received.

The socket option (THIN_DUPACK) is kept as a nop for compatibility.
Note that this patch does not change another thin-stream feature
which enables linear RTO. Although it might be good to generalize
that in the future (i.e., linear RTO for the first say 3 retries).
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4a7f6009
  23. 10 1月, 2017 1 次提交
  25. 30 12月, 2016 2 次提交
  27. 28 12月, 2016 1 次提交
  29. 23 10月, 2016 1 次提交
    • W
      ipv4: use the right lock for ping_group_range · 396a30cc
      由 WANG Cong 提交于 
      This reverts commit a681574c
("ipv4: disable BH in set_ping_group_range()") because we never
read ping_group_range in BH context (unlike local_port_range).

Then, since we already have a lock for ping_group_range, those
using ip_local_ports.lock for ping_group_range are clearly typos.

We might consider to share a same lock for both ping_group_range
and local_port_range w.r.t. space saving, but that should be for
net-next.

Fixes: a681574c ("ipv4: disable BH in set_ping_group_range()")
Fixes: ba6b918a ("ping: move ping_group_range out of CONFIG_SYSCTL")
Cc: Eric Dumazet <edumazet@google.com>
Cc: Eric Salo <salo@google.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      396a30cc
  31. 21 10月, 2016 1 次提交
  33. 24 5月, 2016 1 次提交
    • E
      ipv4: Fix non-initialized TTL when CONFIG_SYSCTL=n · 049bbf58
      由 Ezequiel Garcia 提交于 
      Commit fa50d974 ("ipv4: Namespaceify ip_default_ttl sysctl knob")
moves the default TTL assignment, and as side-effect IPv4 TTL now
has a default value only if sysctl support is enabled (CONFIG_SYSCTL=y).

The sysctl_ip_default_ttl is fundamental for IP to work properly,
as it provides the TTL to be used as default. The defautl TTL may be
used in ip_selected_ttl, through the following flow:

  ip_select_ttl
    ip4_dst_hoplimit
      net->ipv4.sysctl_ip_default_ttl

This commit fixes the issue by assigning net->ipv4.sysctl_ip_default_ttl
in net_init_net, called during ipv4's initialization.

Without this commit, a kernel built without sysctl support will send
all IP packets with zero TTL (unless a TTL is explicitly set, e.g.
with setsockopt).

Given a similar issue might appear on the other knobs that were
namespaceify, this commit also moves them.

Fixes: fa50d974 ("ipv4: Namespaceify ip_default_ttl sysctl knob")
Signed-off-by: NEzequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      049bbf58
  35. 12 4月, 2016 1 次提交
    • D
      net: ipv4: Consider failed nexthops in multipath routes · a6db4494
      由 David Ahern 提交于 
      Multipath route lookups should consider knowledge about next hops and not
select a hop that is known to be failed.

Example:

                     [h2]                   [h3]   15.0.0.5
                      |                      |
                     3|                     3|
                    [SP1]                  [SP2]--+
                     1  2                   1     2
                     |  |     /-------------+     |
                     |   \   /                    |
                     |     X                      |
                     |    / \                     |
                     |   /   \---------------\    |
                     1  2                     1   2
         12.0.0.2  [TOR1] 3-----------------3 [TOR2] 12.0.0.3
                     4                         4
                      \                       /
                        \                    /
                         \                  /
                          -------|   |-----/
                                 1   2
                                [TOR3]
                                  3|
                                   |
                                  [h1]  12.0.0.1

host h1 with IP 12.0.0.1 has 2 paths to host h3 at 15.0.0.5:

    root@h1:~# ip ro ls
    ...
    12.0.0.0/24 dev swp1  proto kernel  scope link  src 12.0.0.1
    15.0.0.0/16
            nexthop via 12.0.0.2  dev swp1 weight 1
            nexthop via 12.0.0.3  dev swp1 weight 1
    ...

If the link between tor3 and tor1 is down and the link between tor1
and tor2 then tor1 is effectively cut-off from h1. Yet the route lookups
in h1 are alternating between the 2 routes: ping 15.0.0.5 gets one and
ssh 15.0.0.5 gets the other. Connections that attempt to use the
12.0.0.2 nexthop fail since that neighbor is not reachable:

    root@h1:~# ip neigh show
    ...
    12.0.0.3 dev swp1 lladdr 00:02:00:00:00:1b REACHABLE
    12.0.0.2 dev swp1  FAILED
    ...

The failed path can be avoided by considering known neighbor information
when selecting next hops. If the neighbor lookup fails we have no
knowledge about the nexthop, so give it a shot. If there is an entry
then only select the nexthop if the state is sane. This is similar to
what fib_detect_death does.

To maintain backward compatibility use of the neighbor information is
based on a new sysctl, fib_multipath_use_neigh.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Reviewed-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a6db4494
  37. 17 2月, 2016 3 次提交
  39. 11 2月, 2016 4 次提交
  41. 08 2月, 2016 8 次提交