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Commit Graph

100 Commits

Author SHA1 Message Date
Eric Dumazet
ed53d0ab76 net: shrink struct sock and request_sock by 8 bytes
One 32bit hole is following skc_refcnt, use it.
skc_incoming_cpu can also be an union for request_sock rcv_wnd.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-12 19:28:22 -07:00
Eric Dumazet
6bcfd7f8c2 tcp: fix RFS vs lockless listeners
Before recent TCP listener patches, we were updating listener
sk->sk_rxhash before the cloning of master socket.

children sk_rxhash was therefore correct after the normal 3WHS.

But with lockless listener, we no longer dirty/change listener sk_rxhash
as it would be racy.

We need to correctly update the child sk_rxhash, otherwise first data
packet wont hit correct cpu if RFS is used.

Fixes: 079096f103 ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Willem de Bruijn <willemb@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Acked-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-11 05:33:15 -07:00
Eric Dumazet
a1a5344ddb tcp: avoid two atomic ops for syncookies
inet_reqsk_alloc() is used to allocate a temporary request
in order to generate a SYNACK with a cookie. Then later,
syncookie validation also uses a temporary request.

These paths already took a reference on listener refcount,
we can avoid a couple of atomic operations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-05 02:45:27 -07:00
Eric Dumazet
079096f103 tcp/dccp: install syn_recv requests into ehash table
In this patch, we insert request sockets into TCP/DCCP
regular ehash table (where ESTABLISHED and TIMEWAIT sockets
are) instead of using the per listener hash table.

ACK packets find SYN_RECV pseudo sockets without having
to find and lock the listener.

In nominal conditions, this halves pressure on listener lock.

Note that this will allow for SO_REUSEPORT refinements,
so that we can select a listener using cpu/numa affinities instead
of the prior 'consistent hash', since only SYN packets will
apply this selection logic.

We will shrink listen_sock in the following patch to ease
code review.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ying Cai <ycai@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03 04:32:41 -07:00
Eric Dumazet
3f684b4b1f tcp: cookie_init_sequence() cleanups
Some common IPv4/IPv6 code can be factorized.
Also constify cookie_init_sequence() socket argument.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29 16:53:09 -07:00
Yuchung Cheng
0f1c28ae74 tcp: usec resolution SYN/ACK RTT
Currently SYN/ACK RTT is measured in jiffies. For LAN the SYN/ACK
RTT is often measured as 0ms or sometimes 1ms, which would affect
RTT estimation and min RTT samping used by some congestion control.

This patch improves SYN/ACK RTT to be usec resolution if platform
supports it. While the timestamping of SYN/ACK is done in request
sock, the RTT measurement is carefully arranged to avoid storing
another u64 timestamp in tcp_sock.

For regular handshake w/o SYNACK retransmission, the RTT is sampled
right after the child socket is created and right before the request
sock is released (tcp_check_req() in tcp_minisocks.c)

For Fast Open the child socket is already created when SYN/ACK was
sent, the RTT is sampled in tcp_rcv_state_process() after processing
the final ACK an right before the request socket is released.

If the SYN/ACK was retransmistted or SYN-cookie was used, we rely
on TCP timestamps to measure the RTT. The sample is taken at the
same place in tcp_rcv_state_process() after the timestamp values
are validated in tcp_validate_incoming(). Note that we do not store
TS echo value in request_sock for SYN-cookies, because the value
is already stored in tp->rx_opt used by tcp_ack_update_rtt().

One side benefit is that the RTT measurement now happens before
initializing congestion control (of the passive side). Therefore
the congestion control can use the SYN/ACK RTT.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-21 16:19:01 -07:00
Eric Dumazet
b80c0e7858 tcp: get_cookie_sock() consolidation
IPv4 and IPv6 share same implementation of get_cookie_sock(),
and there is no point inlining it.

We add tcp_ prefix to the common helper name and export it.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-07 15:19:52 -07:00
Eric Dumazet
0144a81ccc tcp: fix ipv4 mapped request socks
ss should display ipv4 mapped request sockets like this :

tcp    SYN-RECV   0      0  ::ffff:192.168.0.1:8080   ::ffff:192.0.2.1:35261

and not like this :

tcp    SYN-RECV   0      0  192.168.0.1:8080   192.0.2.1:35261

We should init ireq->ireq_family based on listener sk_family,
not the actual protocol carried by SYN packet.

This means we can set ireq_family in inet_reqsk_alloc()

Fixes: 3f66b083a5 ("inet: introduce ireq_family")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-25 00:57:48 -04:00
Eric Dumazet
fa76ce7328 inet: get rid of central tcp/dccp listener timer
One of the major issue for TCP is the SYNACK rtx handling,
done by inet_csk_reqsk_queue_prune(), fired by the keepalive
timer of a TCP_LISTEN socket.

This function runs for awful long times, with socket lock held,
meaning that other cpus needing this lock have to spin for hundred of ms.

SYNACK are sent in huge bursts, likely to cause severe drops anyway.

This model was OK 15 years ago when memory was very tight.

We now can afford to have a timer per request sock.

Timer invocations no longer need to lock the listener,
and can be run from all cpus in parallel.

With following patch increasing somaxconn width to 32 bits,
I tested a listener with more than 4 million active request sockets,
and a steady SYNFLOOD of ~200,000 SYN per second.
Host was sending ~830,000 SYNACK per second.

This is ~100 times more what we could achieve before this patch.

Later, we will get rid of the listener hash and use ehash instead.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-20 12:40:25 -04:00
Eric Dumazet
08d2cc3b26 inet: request sock should init IPv6/IPv4 addresses
In order to be able to use sk_ehashfn() for request socks,
we need to initialize their IPv6/IPv4 addresses.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-18 22:00:35 -04:00
Eric Dumazet
0470c8ca1d inet: fix request sock refcounting
While testing last patch series, I found req sock refcounting was wrong.

We must set skc_refcnt to 1 for all request socks added in hashes,
but also on request sockets created by FastOpen or syncookies.

It is tricky because we need to defer this initialization so that
future RCU lookups do not try to take a refcount on a not yet
fully initialized request socket.

Also get rid of ireq_refcnt alias.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 13854e5a60 ("inet: add proper refcounting to request sock")
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-17 22:02:29 -04:00
Eric Dumazet
9439ce00f2 tcp: rename struct tcp_request_sock listener
The listener field in struct tcp_request_sock is a pointer
back to the listener. We now have req->rsk_listener, so TCP
only needs one boolean and not a full pointer.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-17 22:01:56 -04:00
Eric Dumazet
407640de21 inet: add sk_listener argument to inet_reqsk_alloc()
listener socket can be used to set net pointer, and will
be later used to hold a reference on listener.

Add a const qualifier to first argument (struct request_sock_ops *),
and factorize all write_pnet(&ireq->ireq_net, sock_net(sk));

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-17 22:01:55 -04:00
Eric Dumazet
13854e5a60 inet: add proper refcounting to request sock
reqsk_put() is the generic function that should be used
to release a refcount (and automatically call reqsk_free())

reqsk_free() might be called if refcount is known to be 0
or undefined.

refcnt is set to one in inet_csk_reqsk_queue_add()

As request socks are not yet in global ehash table,
I added temporary debugging checks in reqsk_put() and reqsk_free()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-16 15:55:29 -04:00
Eric Dumazet
16f86165bd inet: fill request sock ir_iif for IPv4
Once request socks will be in ehash table, they will need to have
a valid ir_iff field.

This is currently true only for IPv6. This patch extends support
for IPv4 as well.

This means inet_diag_fill_req() can now properly use ir_iif,
which is better for IPv6 link locals anyway, as request sockets
and established sockets will propagate consistent netlink idiag_if.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-14 15:05:10 -04:00
Eric Dumazet
3f66b083a5 inet: introduce ireq_family
Before inserting request socks into general hash table,
fill their socket family.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-12 22:58:13 -04:00
Eric Dumazet
d77c555d32 net: fix CONFIG_NET_NS=n compilation
I forgot to use write_pnet() in three locations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 33cf7c90fe ("net: add real socket cookies")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-11 23:28:49 -04:00
Eric Dumazet
33cf7c90fe net: add real socket cookies
A long standing problem in netlink socket dumps is the use
of kernel socket addresses as cookies.

1) It is a security concern.

2) Sockets can be reused quite quickly, so there is
   no guarantee a cookie is used once and identify
   a flow.

3) request sock, establish sock, and timewait socks
   for a given flow have different cookies.

Part of our effort to bring better TCP statistics requires
to switch to a different allocator.

In this patch, I chose to use a per network namespace 64bit generator,
and to use it only in the case a socket needs to be dumped to netlink.
(This might be refined later if needed)

Note that I tried to carry cookies from request sock, to establish sock,
then timewait sockets.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Eric Salo <salo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-11 21:55:28 -04:00
Florian Westphal
f7b3bec6f5 net: allow setting ecn via routing table
This patch allows to set ECN on a per-route basis in case the sysctl
tcp_ecn is not set to 1. In other words, when ECN is set for specific
routes, it provides a tcp_ecn=1 behaviour for that route while the rest
of the stack acts according to the global settings.

One can use 'ip route change dev $dev $net features ecn' to toggle this.

Having a more fine-grained per-route setting can be beneficial for various
reasons, for example, 1) within data centers, or 2) local ISPs may deploy
ECN support for their own video/streaming services [1], etc.

There was a recent measurement study/paper [2] which scanned the Alexa's
publicly available top million websites list from a vantage point in US,
Europe and Asia:

Half of the Alexa list will now happily use ECN (tcp_ecn=2, most likely
blamed to commit 255cac91c3 ("tcp: extend ECN sysctl to allow server-side
only ECN") ;)); the break in connectivity on-path was found is about
1 in 10,000 cases. Timeouts rather than receiving back RSTs were much
more common in the negotiation phase (and mostly seen in the Alexa
middle band, ranks around 50k-150k): from 12-thousand hosts on which
there _may_ be ECN-linked connection failures, only 79 failed with RST
when _not_ failing with RST when ECN is not requested.

It's unclear though, how much equipment in the wild actually marks CE
when buffers start to fill up.

We thought about a fallback to non-ECN for retransmitted SYNs as another
global option (which could perhaps one day be made default), but as Eric
points out, there's much more work needed to detect broken middleboxes.

Two examples Eric mentioned are buggy firewalls that accept only a single
SYN per flow, and middleboxes that successfully let an ECN flow establish,
but later mark CE for all packets (so cwnd converges to 1).

 [1] http://www.ietf.org/proceedings/89/slides/slides-89-tsvarea-1.pdf, p.15
 [2] http://ecn.ethz.ch/

Joint work with Daniel Borkmann.

Reference: http://thread.gmane.org/gmane.linux.network/335797
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-04 16:06:09 -05:00
Florian Westphal
f1673381b1 syncookies: split cookie_check_timestamp() into two functions
The function cookie_check_timestamp(), both called from IPv4/6 context,
is being used to decode the echoed timestamp from the SYN/ACK into TCP
options used for follow-up communication with the peer.

We can remove ECN handling from that function, split it into a separate
one, and simply rename the original function into cookie_decode_options().
cookie_decode_options() just fills in tcp_option struct based on the
echoed timestamp received from the peer. Anything that fails in this
function will actually discard the request socket.

While this is the natural place for decoding options such as ECN which
commit 172d69e63c ("syncookies: add support for ECN") added, we argue
that in particular for ECN handling, it can be checked at a later point
in time as the request sock would actually not need to be dropped from
this, but just ECN support turned off.

Therefore, we split this functionality into cookie_ecn_ok(), which tells
us if the timestamp indicates ECN support AND the tcp_ecn sysctl is enabled.

This prepares for per-route ECN support: just looking at the tcp_ecn sysctl
won't be enough anymore at that point; if the timestamp indicates ECN
and sysctl tcp_ecn == 0, we will also need to check the ECN dst metric.

This would mean adding a route lookup to cookie_check_timestamp(), which
we definitely want to avoid. As we already do a route lookup at a later
point in cookie_{v4,v6}_check(), we can simply make use of that as well
for the new cookie_ecn_ok() function w/o any additional cost.

Joint work with Daniel Borkmann.

Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-04 16:06:09 -05:00
Florian Westphal
274e2da0ec syncookies: avoid magic values and document which-bit-is-what-option
Was a bit more difficult to read than needed due to magic shifts;
add defines and document the used encoding scheme.

Joint work with Daniel Borkmann.

Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-04 16:06:08 -05:00
Florian Westphal
646697b9e3 syncookies: only increment SYNCOOKIESFAILED on validation error
Only count packets that failed cookie-authentication.
We can get SYNCOOKIESFAILED > 0 while we never even sent a single cookie.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-30 16:53:39 -04:00
Linus Torvalds
2e923b0251 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Include fixes for netrom and dsa (Fabian Frederick and Florian
    Fainelli)

 2) Fix FIXED_PHY support in stmmac, from Giuseppe CAVALLARO.

 3) Several SKB use after free fixes (vxlan, openvswitch, vxlan,
    ip_tunnel, fou), from Li ROngQing.

 4) fec driver PTP support fixes from Luwei Zhou and Nimrod Andy.

 5) Use after free in virtio_net, from Michael S Tsirkin.

 6) Fix flow mask handling for megaflows in openvswitch, from Pravin B
    Shelar.

 7) ISDN gigaset and capi bug fixes from Tilman Schmidt.

 8) Fix route leak in ip_send_unicast_reply(), from Vasily Averin.

 9) Fix two eBPF JIT bugs on x86, from Alexei Starovoitov.

10) TCP_SKB_CB() reorganization caused a few regressions, fixed by Cong
    Wang and Eric Dumazet.

11) Don't overwrite end of SKB when parsing malformed sctp ASCONF
    chunks, from Daniel Borkmann.

12) Don't call sock_kfree_s() with NULL pointers, this function also has
    the side effect of adjusting the socket memory usage.  From Cong Wang.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (90 commits)
  bna: fix skb->truesize underestimation
  net: dsa: add includes for ethtool and phy_fixed definitions
  openvswitch: Set flow-key members.
  netrom: use linux/uaccess.h
  dsa: Fix conversion from host device to mii bus
  tipc: fix bug in bundled buffer reception
  ipv6: introduce tcp_v6_iif()
  sfc: add support for skb->xmit_more
  r8152: return -EBUSY for runtime suspend
  ipv4: fix a potential use after free in fou.c
  ipv4: fix a potential use after free in ip_tunnel_core.c
  hyperv: Add handling of IP header with option field in netvsc_set_hash()
  openvswitch: Create right mask with disabled megaflows
  vxlan: fix a free after use
  openvswitch: fix a use after free
  ipv4: dst_entry leak in ip_send_unicast_reply()
  ipv4: clean up cookie_v4_check()
  ipv4: share tcp_v4_save_options() with cookie_v4_check()
  ipv4: call __ip_options_echo() in cookie_v4_check()
  atm: simplify lanai.c by using module_pci_driver
  ...
2014-10-18 09:31:37 -07:00
Cong Wang
461b74c391 ipv4: clean up cookie_v4_check()
We can retrieve opt from skb, no need to pass it as a parameter.
And opt should always be non-NULL, no need to check.

Cc: Krzysztof Kolasa <kkolasa@winsoft.pl>
Cc: Eric Dumazet <edumazet@google.com>
Tested-by: Krzysztof Kolasa <kkolasa@winsoft.pl>
Signed-off-by: Cong Wang <cwang@twopensource.com>
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>
2014-10-17 12:02:57 -04:00
Cong Wang
e25f866fbc ipv4: share tcp_v4_save_options() with cookie_v4_check()
cookie_v4_check() allocates ip_options_rcu in the same way
with tcp_v4_save_options(), we can just make it a helper function.

Cc: Krzysztof Kolasa <kkolasa@winsoft.pl>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
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>
2014-10-17 12:02:57 -04:00
Cong Wang
2077eebf7d ipv4: call __ip_options_echo() in cookie_v4_check()
commit 971f10eca1 ("tcp: better TCP_SKB_CB layout to reduce cache line misses")
missed that cookie_v4_check() still calls ip_options_echo() which uses
IPCB(). It should use TCPCB() at TCP layer, so call __ip_options_echo()
instead.

Fixes: commit 971f10eca1 ("tcp: better TCP_SKB_CB layout to reduce cache line misses")
Cc: Krzysztof Kolasa <kkolasa@winsoft.pl>
Cc: Eric Dumazet <edumazet@google.com>
Reported-by: Krzysztof Kolasa <kkolasa@winsoft.pl>
Tested-by: Krzysztof Kolasa <kkolasa@winsoft.pl>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-17 12:02:57 -04:00
Linus Torvalds
0429fbc0bd Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu consistent-ops changes from Tejun Heo:
 "Way back, before the current percpu allocator was implemented, static
  and dynamic percpu memory areas were allocated and handled separately
  and had their own accessors.  The distinction has been gone for many
  years now; however, the now duplicate two sets of accessors remained
  with the pointer based ones - this_cpu_*() - evolving various other
  operations over time.  During the process, we also accumulated other
  inconsistent operations.

  This pull request contains Christoph's patches to clean up the
  duplicate accessor situation.  __get_cpu_var() uses are replaced with
  with this_cpu_ptr() and __this_cpu_ptr() with raw_cpu_ptr().

  Unfortunately, the former sometimes is tricky thanks to C being a bit
  messy with the distinction between lvalues and pointers, which led to
  a rather ugly solution for cpumask_var_t involving the introduction of
  this_cpu_cpumask_var_ptr().

  This converts most of the uses but not all.  Christoph will follow up
  with the remaining conversions in this merge window and hopefully
  remove the obsolete accessors"

* 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (38 commits)
  irqchip: Properly fetch the per cpu offset
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fix
  ia64: sn_nodepda cannot be assigned to after this_cpu conversion. Use __this_cpu_write.
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t
  Revert "powerpc: Replace __get_cpu_var uses"
  percpu: Remove __this_cpu_ptr
  clocksource: Replace __this_cpu_ptr with raw_cpu_ptr
  sparc: Replace __get_cpu_var uses
  avr32: Replace __get_cpu_var with __this_cpu_write
  blackfin: Replace __get_cpu_var uses
  tile: Use this_cpu_ptr() for hardware counters
  tile: Replace __get_cpu_var uses
  powerpc: Replace __get_cpu_var uses
  alpha: Replace __get_cpu_var
  ia64: Replace __get_cpu_var uses
  s390: cio driver &__get_cpu_var replacements
  s390: Replace __get_cpu_var uses
  mips: Replace __get_cpu_var uses
  MIPS: Replace __get_cpu_var uses in FPU emulator.
  arm: Replace __this_cpu_ptr with raw_cpu_ptr
  ...
2014-10-15 07:48:18 +02:00
Florian Westphal
253ff51635 tcp: syncookies: mark cookie_secret read_mostly
only written once.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-27 16:30:49 -07:00
Christoph Lameter
903ceff7ca net: Replace get_cpu_var through this_cpu_ptr
Replace uses of get_cpu_var for address calculation through this_cpu_ptr.

Cc: netdev@vger.kernel.org
Cc: Eric Dumazet <edumazet@google.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-26 13:45:47 -04:00
Octavian Purdila
57b47553f6 tcp: cookie_v4_init_sequence: skb should be const
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-27 15:53:35 -07:00
Lorenzo Colitti
84f39b08d7 net: support marking accepting TCP sockets
When using mark-based routing, sockets returned from accept()
may need to be marked differently depending on the incoming
connection request.

This is the case, for example, if different socket marks identify
different networks: a listening socket may want to accept
connections from all networks, but each connection should be
marked with the network that the request came in on, so that
subsequent packets are sent on the correct network.

This patch adds a sysctl to mark TCP sockets based on the fwmark
of the incoming SYN packet. If enabled, and an unmarked socket
receives a SYN, then the SYN packet's fwmark is written to the
connection's inet_request_sock, and later written back to the
accepted socket when the connection is established.  If the
socket already has a nonzero mark, then the behaviour is the same
as it is today, i.e., the listening socket's fwmark is used.

Black-box tested using user-mode linux:

- IPv4/IPv6 SYN+ACK, FIN, etc. packets are routed based on the
  mark of the incoming SYN packet.
- The socket returned by accept() is marked with the mark of the
  incoming SYN packet.
- Tested with syncookies=1 and syncookies=2.

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 18:35:09 -04:00
Weilong Chen
0c9a67d2ed ipv4: fix checkpatch error "space prohibited"
Signed-off-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-26 13:43:21 -05:00
Hannes Frederic Sowa
b23a002fc6 inet: split syncookie keys for ipv4 and ipv6 and initialize with net_get_random_once
This patch splits the secret key for syncookies for ipv4 and ipv6 and
initializes them with net_get_random_once. This change was the reason I
did this series. I think the initialization of the syncookie_secret is
way to early.

Cc: Florian Westphal <fw@strlen.de>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-19 19:45:35 -04:00
Eric Dumazet
b44084c2c8 inet: rename ir_loc_port to ir_num
In commit 634fb979e8 ("inet: includes a sock_common in request_sock")
I forgot that the two ports in sock_common do not have same byte order :

skc_dport is __be16 (network order), but skc_num is __u16 (host order)

So sparse complains because ir_loc_port (mapped into skc_num) is
considered as __u16 while it should be __be16

Let rename ir_loc_port to ireq->ir_num (analogy with inet->inet_num),
and perform appropriate htons/ntohs conversions.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-10 14:37:35 -04:00
Eric Dumazet
634fb979e8 inet: includes a sock_common in request_sock
TCP listener refactoring, part 5 :

We want to be able to insert request sockets (SYN_RECV) into main
ehash table instead of the per listener hash table to allow RCU
lookups and remove listener lock contention.

This patch includes the needed struct sock_common in front
of struct request_sock

This means there is no more inet6_request_sock IPv6 specific
structure.

Following inet_request_sock fields were renamed as they became
macros to reference fields from struct sock_common.
Prefix ir_ was chosen to avoid name collisions.

loc_port   -> ir_loc_port
loc_addr   -> ir_loc_addr
rmt_addr   -> ir_rmt_addr
rmt_port   -> ir_rmt_port
iif        -> ir_iif

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-10 00:08:07 -04:00
Florian Westphal
086293542b tcp: syncookies: reduce mss table to four values
Halve mss table size to make blind cookie guessing more difficult.
This is sad since the tables were already small, but there
is little alternative except perhaps adding more precise mss information
in the tcp timestamp.  Timestamps are unfortunately not ubiquitous.

Guessing all possible cookie values still has 8-in 2**32 chance.

Reported-by: Jakob Lell <jakob@jakoblell.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-24 10:39:58 -04:00
Florian Westphal
8c27bd75f0 tcp: syncookies: reduce cookie lifetime to 128 seconds
We currently accept cookies that were created less than 4 minutes ago
(ie, cookies with counter delta 0-3).  Combined with the 8 mss table
values, this yields 32 possible values (out of 2**32) that will be valid.

Reducing the lifetime to < 2 minutes halves the guessing chance while
still providing a large enough period.

While at it, get rid of jiffies value -- they overflow too quickly on
32 bit platforms.

getnstimeofday is used to create a counter that increments every 64s.
perf shows getnstimeofday cost is negible compared to sha_transform;
normal tcp initial sequence number generation uses getnstimeofday, too.

Reported-by: Jakob Lell <jakob@jakoblell.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-24 10:39:58 -04:00
Patrick McHardy
0198230b77 net: syncookies: export cookie_v4_init_sequence/cookie_v4_check
Extract the local TCP stack independant parts of tcp_v4_init_sequence()
and cookie_v4_check() and export them for use by the upcoming SYNPROXY
target.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: Martin Topholm <mph@one.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-08-28 00:27:44 +02:00
David S. Miller
6e0895c2ea Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/emulex/benet/be_main.c
	drivers/net/ethernet/intel/igb/igb_main.c
	drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c
	include/net/scm.h
	net/batman-adv/routing.c
	net/ipv4/tcp_input.c

The e{uid,gid} --> {uid,gid} credentials fix conflicted with the
cleanup in net-next to now pass cred structs around.

The be2net driver had a bug fix in 'net' that overlapped with the VLAN
interface changes by Patrick McHardy in net-next.

An IGB conflict existed because in 'net' the build_skb() support was
reverted, and in 'net-next' there was a comment style fix within that
code.

Several batman-adv conflicts were resolved by making sure that all
calls to batadv_is_my_mac() are changed to have a new bat_priv first
argument.

Eric Dumazet's TS ECR fix in TCP in 'net' conflicted with the F-RTO
rewrite in 'net-next', mostly overlapping changes.

Thanks to Stephen Rothwell and Antonio Quartulli for help with several
of these merge resolutions.

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-22 20:32:51 -04:00
Dmitry Popov
d66954a066 tcp: incoming connections might use wrong route under synflood
There is a bug in cookie_v4_check (net/ipv4/syncookies.c):
	flowi4_init_output(&fl4, 0, sk->sk_mark, RT_CONN_FLAGS(sk),
			   RT_SCOPE_UNIVERSE, IPPROTO_TCP,
			   inet_sk_flowi_flags(sk),
			   (opt && opt->srr) ? opt->faddr : ireq->rmt_addr,
			   ireq->loc_addr, th->source, th->dest);

Here we do not respect sk->sk_bound_dev_if, therefore wrong dst_entry may be
taken. This dst_entry is used by new socket (get_cookie_sock ->
tcp_v4_syn_recv_sock), so its packets may take the wrong path.

Signed-off-by: Dmitry Popov <dp@highloadlab.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-11 16:01:46 -04:00
Christoph Paasch
1a2c6181c4 tcp: Remove TCPCT
TCPCT uses option-number 253, reserved for experimental use and should
not be used in production environments.
Further, TCPCT does not fully implement RFC 6013.

As a nice side-effect, removing TCPCT increases TCP's performance for
very short flows:

Doing an apache-benchmark with -c 100 -n 100000, sending HTTP-requests
for files of 1KB size.

before this patch:
	average (among 7 runs) of 20845.5 Requests/Second
after:
	average (among 7 runs) of 21403.6 Requests/Second

Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-17 14:35:13 -04:00
Hannes Frederic Sowa
5d134f1c1f tcp: make sysctl_tcp_ecn namespace aware
As per suggestion from Eric Dumazet this patch makes tcp_ecn sysctl
namespace aware.  The reason behind this patch is to ease the testing
of ecn problems on the internet and allows applications to tune their
own use of ecn.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-06 21:09:56 -08:00
Eric Dumazet
e6c022a4fa tcp: better retrans tracking for defer-accept
For passive TCP connections using TCP_DEFER_ACCEPT facility,
we incorrectly increment req->retrans each time timeout triggers
while no SYNACK is sent.

SYNACK are not sent for TCP_DEFER_ACCEPT that were established (for
which we received the ACK from client). Only the last SYNACK is sent
so that we can receive again an ACK from client, to move the req into
accept queue. We plan to change this later to avoid the useless
retransmit (and potential problem as this SYNACK could be lost)

TCP_INFO later gives wrong information to user, claiming imaginary
retransmits.

Decouple req->retrans field into two independent fields :

num_retrans : number of retransmit
num_timeout : number of timeouts

num_timeout is the counter that is incremented at each timeout,
regardless of actual SYNACK being sent or not, and used to
compute the exponential timeout.

Introduce inet_rtx_syn_ack() helper to increment num_retrans
only if ->rtx_syn_ack() succeeded.

Use inet_rtx_syn_ack() from tcp_check_req() to increment num_retrans
when we re-send a SYNACK in answer to a (retransmitted) SYN.
Prior to this patch, we were not counting these retransmits.

Change tcp_v[46]_rtx_synack() to increment TCP_MIB_RETRANSSEGS
only if a synack packet was successfully queued.

Reported-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Julian Anastasov <ja@ssi.bg>
Cc: Vijay Subramanian <subramanian.vijay@gmail.com>
Cc: Elliott Hughes <enh@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-03 14:45:00 -04:00
Jerry Chu
8336886f78 tcp: TCP Fast Open Server - support TFO listeners
This patch builds on top of the previous patch to add the support
for TFO listeners. This includes -

1. allocating, properly initializing, and managing the per listener
fastopen_queue structure when TFO is enabled

2. changes to the inet_csk_accept code to support TFO. E.g., the
request_sock can no longer be freed upon accept(), not until 3WHS
finishes

3. allowing a TCP_SYN_RECV socket to properly poll() and sendmsg()
if it's a TFO socket

4. properly closing a TFO listener, and a TFO socket before 3WHS
finishes

5. supporting TCP_FASTOPEN socket option

6. modifying tcp_check_req() to use to check a TFO socket as well
as request_sock

7. supporting TCP's TFO cookie option

8. adding a new SYN-ACK retransmit handler to use the timer directly
off the TFO socket rather than the listener socket. Note that TFO
server side will not retransmit anything other than SYN-ACK until
the 3WHS is completed.

The patch also contains an important function
"reqsk_fastopen_remove()" to manage the somewhat complex relation
between a listener, its request_sock, and the corresponding child
socket. See the comment above the function for the detail.

Signed-off-by: H.K. Jerry Chu <hkchu@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-31 20:02:19 -04:00
Yuchung Cheng
2100c8d2d9 net-tcp: Fast Open base
This patch impelements the common code for both the client and server.

1. TCP Fast Open option processing. Since Fast Open does not have an
   option number assigned by IANA yet, it shares the experiment option
   code 254 by implementing draft-ietf-tcpm-experimental-options
   with a 16 bits magic number 0xF989. This enables global experiments
   without clashing the scarce(2) experimental options available for TCP.

   When the draft status becomes standard (maybe), the client should
   switch to the new option number assigned while the server supports
   both numbers for transistion.

2. The new sysctl tcp_fastopen

3. A place holder init function

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19 10:55:36 -07:00
Eric Dumazet
dfd25ffffc tcp: fix syncookie regression
commit ea4fc0d619 (ipv4: Don't use rt->rt_{src,dst} in ip_queue_xmit())
added a serious regression on synflood handling.

Simon Kirby discovered a successful connection was delayed by 20 seconds
before being responsive.

In my tests, I discovered that xmit frames were lost, and needed ~4
retransmits and a socket dst rebuild before being really sent.

In case of syncookie initiated connection, we use a different path to
initialize the socket dst, and inet->cork.fl.u.ip4 is left cleared.

As ip_queue_xmit() now depends on inet flow being setup, fix this by
copying the temp flowi4 we use in cookie_v4_check().

Reported-by: Simon Kirby <sim@netnation.com>
Bisected-by: Simon Kirby <sim@netnation.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-11 15:52:12 -07:00
Vijay Subramanian
ab56222a32 tcp: Replace constants with #define macros
to record the state of SACK/FACK and DSACK for better readability and maintenance.

Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-21 01:03:23 -05:00
Paul Gortmaker
bc3b2d7fb9 net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules
These files are non modular, but need to export symbols using
the macros now living in export.h -- call out the include so
that things won't break when we remove the implicit presence
of module.h from everywhere.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:30:30 -04:00
Eric Dumazet
cf533ea53e tcp: add const qualifiers where possible
Adding const qualifiers to pointers can ease code review, and spot some
bugs. It might allow compiler to optimize code further.

For example, is it legal to temporary write a null cksum into tcphdr
in tcp_md5_hash_header() ? I am afraid a sniffer could catch the
temporary null value...

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-21 05:22:42 -04:00
Mike Waychison
f0e3d0689d tcp: initialize variable ecn_ok in syncookies path
Using a gcc 4.4.3, warnings are emitted for a possibly uninitialized use
of ecn_ok.

This can happen if cookie_check_timestamp() returns due to not having
seen a timestamp.  Defaulting to ecn off seems like a reasonable thing
to do in this case, so initialized ecn_ok to false.

Signed-off-by: Mike Waychison <mikew@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-10 21:59:57 -07:00