Commit Graph

570 Commits

Author SHA1 Message Date
Eric Dumazet 5d2ed0521a tcp: Namespaceify sysctl_tcp_timestamps
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 10:53:29 -04:00
Eric Dumazet 9a568de481 tcp: switch TCP TS option (RFC 7323) to 1ms clock
TCP Timestamps option is defined in RFC 7323

Traditionally on linux, it has been tied to the internal
'jiffies' variable, because it had been a cheap and good enough
generator.

For TCP flows on the Internet, 1 ms resolution would be much better
than 4ms or 10ms (HZ=250 or HZ=100 respectively)

For TCP flows in the DC, Google has used usec resolution for more
than two years with great success [1]

Receive size autotuning (DRS) is indeed more precise and converges
faster to optimal window size.

This patch converts tp->tcp_mstamp to a plain u64 value storing
a 1 usec TCP clock.

This choice will allow us to upstream the 1 usec TS option as
discussed in IETF 97.

[1] https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-tcp-options-for-low-latency-00.pdf

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-17 16:06:01 -04:00
Linus Torvalds a95cfad947 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Track alignment in BPF verifier so that legitimate programs won't be
    rejected on !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS architectures.

 2) Make tail calls work properly in arm64 BPF JIT, from Deniel
    Borkmann.

 3) Make the configuration and semantics Generic XDP make more sense and
    don't allow both generic XDP and a driver specific instance to be
    active at the same time. Also from Daniel.

 4) Don't crash on resume in xen-netfront, from Vitaly Kuznetsov.

 5) Fix use-after-free in VRF driver, from Gao Feng.

 6) Use netdev_alloc_skb_ip_align() to avoid unaligned IP headers in
    qca_spi driver, from Stefan Wahren.

 7) Always run cleanup routines in BPF samples when we get SIGTERM, from
    Andy Gospodarek.

 8) The mdio phy code should bring PHYs out of reset using the shared
    GPIO lines before invoking bus->reset(). From Florian Fainelli.

 9) Some USB descriptor access endian fixes in various drivers from
    Johan Hovold.

10) Handle PAUSE advertisements properly in mlx5 driver, from Gal
    Pressman.

11) Fix reversed test in mlx5e_setup_tc(), from Saeed Mahameed.

12) Cure netdev leak in AF_PACKET when using timestamping via control
    messages. From Douglas Caetano dos Santos.

13) netcp doesn't support HWTSTAMP_FILTER_ALl, reject it. From Miroslav
    Lichvar.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (52 commits)
  ldmvsw: stop the clean timer at beginning of remove
  ldmvsw: unregistering netdev before disable hardware
  net: netcp: fix check of requested timestamping filter
  ipv6: avoid dad-failures for addresses with NODAD
  qed: Fix uninitialized data in aRFS infrastructure
  mdio: mux: fix device_node_continue.cocci warnings
  net/packet: fix missing net_device reference release
  net/mlx4_core: Use min3 to select number of MSI-X vectors
  macvlan: Fix performance issues with vlan tagged packets
  net: stmmac: use correct pointer when printing normal descriptor ring
  net/mlx5: Use underlay QPN from the root name space
  net/mlx5e: IPoIB, Only support regular RQ for now
  net/mlx5e: Fix setup TC ndo
  net/mlx5e: Fix ethtool pause support and advertise reporting
  net/mlx5e: Use the correct pause values for ethtool advertising
  vmxnet3: ensure that adapter is in proper state during force_close
  sfc: revert changes to NIC revision numbers
  net: ch9200: add missing USB-descriptor endianness conversions
  net: irda: irda-usb: fix firmware name on big-endian hosts
  net: dsa: mv88e6xxx: add default case to switch
  ...
2017-05-15 15:50:49 -07:00
WANG Cong 83eaddab43 ipv6/dccp: do not inherit ipv6_mc_list from parent
Like commit 657831ffc3 ("dccp/tcp: do not inherit mc_list from parent")
we should clear ipv6_mc_list etc. for IPv6 sockets too.

Cc: Eric Dumazet <edumazet@google.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>
2017-05-11 12:17:02 -04:00
Linus Torvalds de4d195308 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "The main changes are:

   - Debloat RCU headers

   - Parallelize SRCU callback handling (plus overlapping patches)

   - Improve the performance of Tree SRCU on a CPU-hotplug stress test

   - Documentation updates

   - Miscellaneous fixes"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (74 commits)
  rcu: Open-code the rcu_cblist_n_lazy_cbs() function
  rcu: Open-code the rcu_cblist_n_cbs() function
  rcu: Open-code the rcu_cblist_empty() function
  rcu: Separately compile large rcu_segcblist functions
  srcu: Debloat the <linux/rcu_segcblist.h> header
  srcu: Adjust default auto-expediting holdoff
  srcu: Specify auto-expedite holdoff time
  srcu: Expedite first synchronize_srcu() when idle
  srcu: Expedited grace periods with reduced memory contention
  srcu: Make rcutorture writer stalls print SRCU GP state
  srcu: Exact tracking of srcu_data structures containing callbacks
  srcu: Make SRCU be built by default
  srcu: Fix Kconfig botch when SRCU not selected
  rcu: Make non-preemptive schedule be Tasks RCU quiescent state
  srcu: Expedite srcu_schedule_cbs_snp() callback invocation
  srcu: Parallelize callback handling
  kvm: Move srcu_struct fields to end of struct kvm
  rcu: Fix typo in PER_RCU_NODE_PERIOD header comment
  rcu: Use true/false in assignment to bool
  rcu: Use bool value directly
  ...
2017-05-10 10:30:46 -07:00
Eric Dumazet 84b114b984 tcp: randomize timestamps on syncookies
Whole point of randomization was to hide server uptime, but an attacker
can simply start a syn flood and TCP generates 'old style' timestamps,
directly revealing server jiffies value.

Also, TSval sent by the server to a particular remote address vary
depending on syncookies being sent or not, potentially triggering PAWS
drops for innocent clients.

Lets implement proper randomization, including for SYNcookies.

Also we do not need to export sysctl_tcp_timestamps, since it is not
used from a module.

In v2, I added Florian feedback and contribution, adding tsoff to
tcp_get_cookie_sock().

v3 removed one unused variable in tcp_v4_connect() as Florian spotted.

Fixes: 95a22caee3 ("tcp: randomize tcp timestamp offsets for each connection")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Tested-by: Florian Westphal <fw@strlen.de>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-05 12:00:11 -04:00
Ingo Molnar 58d30c36d4 Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:

 - Documentation updates.

 - Miscellaneous fixes.

 - Parallelize SRCU callback handling (plus overlapping patches).

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-04-23 11:12:44 +02:00
Paul E. McKenney 5f0d5a3ae7 mm: Rename SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU
A group of Linux kernel hackers reported chasing a bug that resulted
from their assumption that SLAB_DESTROY_BY_RCU provided an existence
guarantee, that is, that no block from such a slab would be reallocated
during an RCU read-side critical section.  Of course, that is not the
case.  Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire
slab of blocks.

However, there is a phrase for this, namely "type safety".  This commit
therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order
to avoid future instances of this sort of confusion.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <linux-mm@kvack.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
[ paulmck: Add comments mentioning the old name, as requested by Eric
  Dumazet, in order to help people familiar with the old name find
  the new one. ]
Acked-by: David Rientjes <rientjes@google.com>
2017-04-18 11:42:36 -07:00
Alexander Duyck e5907459ce tcp: Record Rx hash and NAPI ID in tcp_child_process
While working on some recent busy poll changes we found that child sockets
were being instantiated without NAPI ID being set.  In our first attempt to
fix it, it was suggested that we should just pull programming the NAPI ID
into the function itself since all callers will need to have it set.

In addition to the NAPI ID change I have dropped the code that was
populating the Rx hash since it was actually being populated in
tcp_get_cookie_sock.

Reported-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-24 20:49:30 -07:00
subashab@codeaurora.org dddb64bcb3 net: Add sysctl to toggle early demux for tcp and udp
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: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Suggested-by: Eric 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: David S. Miller <davem@davemloft.net>
2017-03-24 13:17:07 -07:00
Soheil Hassas Yeganeh 4396e46187 tcp: remove tcp_tw_recycle
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: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Cc: Lutz Vieweg <lvml@5t9.de>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-16 20:33:56 -07:00
Soheil Hassas Yeganeh d82bae12dc tcp: remove per-destination timestamp cache
Commit 8a5bd45f6616 (tcp: randomize tcp timestamp offsets for each connection)
randomizes TCP timestamps per connection. After this commit,
there is no guarantee that the timestamps received from the
same destination are monotonically increasing. As a result,
the per-destination timestamp cache in TCP metrics (i.e., tcpm_ts
in struct tcp_metrics_block) is broken and cannot be relied upon.

Remove the per-destination timestamp cache and all related code
paths.

Note that this cache was already broken for caching timestamps of
multiple machines behind a NAT sharing the same address.

Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Cc: Lutz Vieweg <lvml@5t9.de>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-16 20:33:56 -07:00
David S. Miller 101c431492 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/broadcom/genet/bcmgenet.c
	net/core/sock.c

Conflicts were overlapping changes in bcmgenet and the
lockdep handling of sockets.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-15 11:59:10 -07:00
Jon Maxwell 45caeaa5ac dccp/tcp: fix routing redirect race
As Eric Dumazet pointed out this also needs to be fixed in IPv6.
v2: Contains the IPv6 tcp/Ipv6 dccp patches as well.

We have seen a few incidents lately where a dst_enty has been freed
with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that
dst_entry. If the conditions/timings are right a crash then ensues when the
freed dst_entry is referenced later on. A Common crashing back trace is:

 #8 [] page_fault at ffffffff8163e648
    [exception RIP: __tcp_ack_snd_check+74]
.
.
 #9 [] tcp_rcv_established at ffffffff81580b64
#10 [] tcp_v4_do_rcv at ffffffff8158b54a
#11 [] tcp_v4_rcv at ffffffff8158cd02
#12 [] ip_local_deliver_finish at ffffffff815668f4
#13 [] ip_local_deliver at ffffffff81566bd9
#14 [] ip_rcv_finish at ffffffff8156656d
#15 [] ip_rcv at ffffffff81566f06
#16 [] __netif_receive_skb_core at ffffffff8152b3a2
#17 [] __netif_receive_skb at ffffffff8152b608
#18 [] netif_receive_skb at ffffffff8152b690
#19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3]
#20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3]
#21 [] net_rx_action at ffffffff8152bac2
#22 [] __do_softirq at ffffffff81084b4f
#23 [] call_softirq at ffffffff8164845c
#24 [] do_softirq at ffffffff81016fc5
#25 [] irq_exit at ffffffff81084ee5
#26 [] do_IRQ at ffffffff81648ff8

Of course it may happen with other NIC drivers as well.

It's found the freed dst_entry here:

 224 static bool tcp_in_quickack_mode(struct sock *sk)↩
 225 {↩
 226 ▹       const struct inet_connection_sock *icsk = inet_csk(sk);↩
 227 ▹       const struct dst_entry *dst = __sk_dst_get(sk);↩
 228 ↩
 229 ▹       return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩
 230 ▹       ▹       (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩
 231 }↩

But there are other backtraces attributed to the same freed dst_entry in
netfilter code as well.

All the vmcores showed 2 significant clues:

- Remote hosts behind the default gateway had always been redirected to a
different gateway. A rtable/dst_entry will be added for that host. Making
more dst_entrys with lower reference counts. Making this more probable.

- All vmcores showed a postitive LockDroppedIcmps value, e.g:

LockDroppedIcmps                  267

A closer look at the tcp_v4_err() handler revealed that do_redirect() will run
regardless of whether user space has the socket locked. This can result in a
race condition where the same dst_entry cached in sk->sk_dst_entry can be
decremented twice for the same socket via:

do_redirect()->__sk_dst_check()-> dst_release().

Which leads to the dst_entry being prematurely freed with another socket
pointing to it via sk->sk_dst_cache and a subsequent crash.

To fix this skip do_redirect() if usespace has the socket locked. Instead let
the redirect take place later when user space does not have the socket
locked.

The dccp/IPv6 code is very similar in this respect, so fixing it there too.

As Eric Garver pointed out the following commit now invalidates routes. Which
can set the dst->obsolete flag so that ipv4_dst_check() returns null and
triggers the dst_release().

Fixes: ceb3320610 ("ipv4: Kill routes during PMTU/redirect updates.")
Cc: Eric Garver <egarver@redhat.com>
Cc: Hannes Sowa <hsowa@redhat.com>
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-13 21:55:47 -07:00
Alexey Kodanev a30aad50c2 tcp: rename *_sequence_number() to *_seq_and_tsoff()
The functions that are returning tcp sequence number also setup
TS offset value, so rename them to better describe their purpose.

No functional changes in this patch.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-09 18:25:34 -08:00
Alexey Kodanev 00355fa5bb tcp: setup timestamp offset when write_seq already set
Found that when randomized tcp offsets are enabled (by default)
TCP client can still start new connections without them. Later,
if server does active close and re-uses sockets in TIME-WAIT
state, new SYN from client can be rejected on PAWS check inside
tcp_timewait_state_process(), because either tw_ts_recent or
rcv_tsval doesn't really have an offset set.

Here is how to reproduce it with LTP netstress tool:
    netstress -R 1 &
    netstress -H 127.0.0.1 -lr 1000000 -a1

    [...]
    < S  seq 1956977072 win 43690 TS val 295618 ecr 459956970
    > .  ack 1956911535 win 342 TS val 459967184 ecr 1547117608
    < R  seq 1956911535 win 0 length 0
+1. < S  seq 1956977072 win 43690 TS val 296640 ecr 459956970
    > S. seq 657450664 ack 1956977073 win 43690 TS val 459968205 ecr 296640

Fixes: 95a22caee3 ("tcp: randomize tcp timestamp offsets for each connection")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-22 16:35:32 -05:00
David S. Miller 3f64116a83 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-02-16 19:34:01 -05:00
Jonathan T. Leighton 052d2369d1 ipv6: Handle IPv4-mapped src to in6addr_any dst.
This patch adds a check on the type of the source address for the case
where the destination address is in6addr_any. If the source is an
IPv4-mapped IPv6 source address, the destination is changed to
::ffff:127.0.0.1, and otherwise the destination is changed to ::1. This
is done in three locations to handle UDP calls to either connect() or
sendmsg() and TCP calls to connect(). Note that udpv6_sendmsg() delays
handling an in6addr_any destination until very late, so the patch only
needs to handle the case where the source is an IPv4-mapped IPv6
address.

Signed-off-by: Jonathan T. Leighton <jtleight@udel.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-14 12:13:51 -05:00
David S. Miller 3efa70d78f Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
The conflict was an interaction between a bug fix in the
netvsc driver in 'net' and an optimization of the RX path
in 'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-07 16:29:30 -05:00
Eric Dumazet ebf6c9cb23 ipv6: tcp: add a missing tcp_v6_restore_cb()
Dmitry reported use-after-free in ip6_datagram_recv_specific_ctl()

A similar bug was fixed in commit 8ce48623f0 ("ipv6: tcp: restore
IP6CB for pktoptions skbs"), but I missed another spot.

tcp_v6_syn_recv_sock() can indeed set np->pktoptions from ireq->pktopts

Fixes: 971f10eca1 ("tcp: better TCP_SKB_CB layout to reduce cache line misses")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-06 10:52:45 -05:00
Eric Dumazet 3541f9e8bd tcp: add tcp_mss_clamp() helper
Small cleanup factorizing code doing the TCP_MAXSEG clamping.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-03 11:19:34 -05:00
David S. Miller 4e8f2fc1a5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Two trivial overlapping changes conflicts in MPLS and mlx5.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-28 10:33:06 -05:00
Pablo Neira 92e55f412c tcp: don't annotate mark on control socket from tcp_v6_send_response()
Unlike ipv4, this control socket is shared by all cpus so we cannot use
it as scratchpad area to annotate the mark that we pass to ip6_xmit().

Add a new parameter to ip6_xmit() to indicate the mark. The SCTP socket
family caches the flowi6 structure in the sctp_transport structure, so
we cannot use to carry the mark unless we later on reset it back, which
I discarded since it looks ugly to me.

Fixes: bf99b4ded5 ("tcp: fix mark propagation with fwmark_reflect enabled")
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-27 10:33:56 -05:00
Wei Wang 19f6d3f3c8 net/tcp-fastopen: Add new API support
This patch adds a new socket option, TCP_FASTOPEN_CONNECT, as an
alternative way to perform Fast Open on the active side (client). Prior
to this patch, a client needs to replace the connect() call with
sendto(MSG_FASTOPEN). This can be cumbersome for applications who want
to use Fast Open: these socket operations are often done in lower layer
libraries used by many other applications. Changing these libraries
and/or the socket call sequences are not trivial. A more convenient
approach is to perform Fast Open by simply enabling a socket option when
the socket is created w/o changing other socket calls sequence:
  s = socket()
    create a new socket
  setsockopt(s, IPPROTO_TCP, TCP_FASTOPEN_CONNECT …);
    newly introduced sockopt
    If set, new functionality described below will be used.
    Return ENOTSUPP if TFO is not supported or not enabled in the
    kernel.

  connect()
    With cookie present, return 0 immediately.
    With no cookie, initiate 3WHS with TFO cookie-request option and
    return -1 with errno = EINPROGRESS.

  write()/sendmsg()
    With cookie present, send out SYN with data and return the number of
    bytes buffered.
    With no cookie, and 3WHS not yet completed, return -1 with errno =
    EINPROGRESS.
    No MSG_FASTOPEN flag is needed.

  read()
    Return -1 with errno = EWOULDBLOCK/EAGAIN if connect() is called but
    write() is not called yet.
    Return -1 with errno = EWOULDBLOCK/EAGAIN if connection is
    established but no msg is received yet.
    Return number of bytes read if socket is established and there is
    msg received.

The new API simplifies life for applications that always perform a write()
immediately after a successful connect(). Such applications can now take
advantage of Fast Open by merely making one new setsockopt() call at the time
of creating the socket. Nothing else about the application's socket call
sequence needs to change.

Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-25 14:04:38 -05:00
Wei Wang 25776aa943 net: Remove __sk_dst_reset() in tcp_v6_connect()
Remove __sk_dst_reset() in the failure handling because __sk_dst_reset()
will eventually get called when sk is released. No need to handle it in
the protocol specific connect call.
This is also to make the code path consistent with ipv4.

Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-25 14:04:38 -05:00
Josef Bacik aa078842b7 inet: drop ->bind_conflict
The only difference between inet6_csk_bind_conflict and inet_csk_bind_conflict
is how they check the rcv_saddr, so delete this call back and simply
change inet_csk_bind_conflict to call inet_rcv_saddr_equal.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-18 13:04:28 -05:00
Yuchung Cheng bec41a11dd tcp: remove early retransmit
This patch removes the support of RFC5827 early retransmit (i.e.,
fast recovery on small inflight with <3 dupacks) because it is
subsumed by the new RACK loss detection. More specifically when
RACK receives DUPACKs, it'll arm a reordering timer to start fast
recovery after a quarter of (min)RTT, hence it covers the early
retransmit except RACK does not limit itself to specific inflight
or dupack numbers.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-13 22:37:16 -05:00
Yuchung Cheng 57dde7f70d tcp: add reordering timer in RACK loss detection
This patch makes RACK install a reordering timer when it suspects
some packets might be lost, but wants to delay the decision
a little bit to accomodate reordering.

It does not create a new timer but instead repurposes the existing
RTO timer, because both are meant to retransmit packets.
Specifically it arms a timer ICSK_TIME_REO_TIMEOUT when
the RACK timing check fails. The wait time is set to

  RACK.RTT + RACK.reo_wnd - (NOW - Packet.xmit_time) + fudge

This translates to expecting a packet (Packet) should take
(RACK.RTT + RACK.reo_wnd + fudge) to deliver after it was sent.

When there are multiple packets that need a timer, we use one timer
with the maximum timeout. Therefore the timer conservatively uses
the maximum window to expire N packets by one timeout, instead of
N timeouts to expire N packets sent at different times.

The fudge factor is 2 jiffies to ensure when the timer fires, all
the suspected packets would exceed the deadline and be marked lost
by tcp_rack_detect_loss(). It has to be at least 1 jiffy because the
clock may tick between calling icsk_reset_xmit_timer(timeout) and
actually hang the timer. The next jiffy is to lower-bound the timeout
to 2 jiffies when reo_wnd is < 1ms.

When the reordering timer fires (tcp_rack_reo_timeout): If we aren't
in Recovery we'll enter fast recovery and force fast retransmit.
This is very similar to the early retransmit (RFC5827) except RACK
is not constrained to only enter recovery for small outstanding
flights.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-13 22:37:16 -05:00
Ursula Braun 4b9d07a440 net: introduce keepalive function in struct proto
Direct call of tcp_set_keepalive() function from protocol-agnostic
sock_setsockopt() function in net/core/sock.c violates network
layering. And newly introduced protocol (SMC-R) will need its own
keepalive function. Therefore, add "keepalive" function pointer
to "struct proto", and call it from sock_setsockopt() via this pointer.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Reviewed-by: Utz Bacher <utz.bacher@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-09 16:07:37 -05:00
Pau Espin Pedrol bf99b4ded5 tcp: fix mark propagation with fwmark_reflect enabled
Otherwise, RST packets generated by the TCP stack for non-existing
sockets always have mark 0.
The mark from the original packet is assigned to the netns_ipv4/6
socket used to send the response so that it can get copied into the
response skb when the socket sends it.

Fixes: e110861f86 ("net: add a sysctl to reflect the fwmark on replies")
Cc: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Pau Espin Pedrol <pau.espin@tessares.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-01-09 18:01:03 +01:00
Haishuang Yan 1946e672c1 ipv4: Namespaceify tcp_tw_recycle and tcp_max_tw_buckets knob
Different namespace application might require fast recycling
TIME-WAIT sockets independently of the host.

Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-29 11:38:31 -05:00
Eric Dumazet 7aa5470c2c tcp: tsq: move tsq_flags close to sk_wmem_alloc
tsq_flags being in the same cache line than sk_wmem_alloc
makes a lot of sense. Both fields are changed from tcp_wfree()
and more generally by various TSQ related functions.

Prior patch made room in struct sock and added sk_tsq_flags,
this patch deletes tsq_flags from struct tcp_sock.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-05 13:32:24 -05:00
Florian Westphal 95a22caee3 tcp: randomize tcp timestamp offsets for each connection
jiffies based timestamps allow for easy inference of number of devices
behind NAT translators and also makes tracking of hosts simpler.

commit ceaa1fef65 ("tcp: adding a per-socket timestamp offset")
added the main infrastructure that is needed for per-connection ts
randomization, in particular writing/reading the on-wire tcp header
format takes the offset into account so rest of stack can use normal
tcp_time_stamp (jiffies).

So only two items are left:
 - add a tsoffset for request sockets
 - extend the tcp isn generator to also return another 32bit number
   in addition to the ISN.

Re-use of ISN generator also means timestamps are still monotonically
increasing for same connection quadruple, i.e. PAWS will still work.

Includes fixes from Eric Dumazet.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02 12:49:59 -05:00
David S. Miller bb598c1b8c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Several cases of bug fixes in 'net' overlapping other changes in
'net-next-.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-15 10:54:36 -05:00
Eric Dumazet ac6e780070 tcp: take care of truncations done by sk_filter()
With syzkaller help, Marco Grassi found a bug in TCP stack,
crashing in tcp_collapse()

Root cause is that sk_filter() can truncate the incoming skb,
but TCP stack was not really expecting this to happen.
It probably was expecting a simple DROP or ACCEPT behavior.

We first need to make sure no part of TCP header could be removed.
Then we need to adjust TCP_SKB_CB(skb)->end_seq

Many thanks to syzkaller team and Marco for giving us a reproducer.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Marco Grassi <marco.gra@gmail.com>
Reported-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-13 12:30:02 -05:00
David Ahern 9b6c14d51b net: tcp response should set oif only if it is L3 master
Lorenzo noted an Android unit test failed due to e0d56fdd7342:
"The expectation in the test was that the RST replying to a SYN sent to a
closed port should be generated with oif=0. In other words it should not
prefer the interface where the SYN came in on, but instead should follow
whatever the routing table says it should do."

Revert the change to ip_send_unicast_reply and tcp_v6_send_response such
that the oif in the flow is set to the skb_iif only if skb_iif is an L3
master.

Fixes: e0d56fdd73 ("net: l3mdev: remove redundant calls")
Reported-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Tested-by: Lorenzo Colitti <lorenzo@google.com>
Acked-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-09 22:32:10 -05:00
Lorenzo Colitti e2d118a1cb net: inet: Support UID-based routing in IP protocols.
- Use the UID in routing lookups made by protocol connect() and
  sendmsg() functions.
- Make sure that routing lookups triggered by incoming packets
  (e.g., Path MTU discovery) take the UID of the socket into
  account.
- For packets not associated with a userspace socket, (e.g., ping
  replies) use UID 0 inside the user namespace corresponding to
  the network namespace the socket belongs to. This allows
  all namespaces to apply routing and iptables rules to
  kernel-originated traffic in that namespaces by matching UID 0.
  This is better than using the UID of the kernel socket that is
  sending the traffic, because the UID of kernel sockets created
  at namespace creation time (e.g., the per-processor ICMP and
  TCP sockets) is the UID of the user that created the socket,
  which might not be mapped in the namespace.

Tested: compiles allnoconfig, allyesconfig, allmodconfig
Tested: https://android-review.googlesource.com/253302
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-04 14:45:23 -04:00
Eric Dumazet 8ce48623f0 ipv6: tcp: restore IP6CB for pktoptions skbs
Baozeng Ding reported following KASAN splat :

BUG: KASAN: use-after-free in ip6_datagram_recv_specific_ctl+0x13f1/0x15c0 at addr ffff880029c84ec8
Read of size 1 by task poc/25548
Call Trace:
 [<ffffffff82cf43c9>] dump_stack+0x12e/0x185 /lib/dump_stack.c:15
 [<     inline     >] print_address_description /mm/kasan/report.c:204
 [<ffffffff817ced3b>] kasan_report_error+0x48b/0x4b0 /mm/kasan/report.c:283
 [<     inline     >] kasan_report /mm/kasan/report.c:303
 [<ffffffff817ced9e>] __asan_report_load1_noabort+0x3e/0x40 /mm/kasan/report.c:321
 [<ffffffff85c71da1>] ip6_datagram_recv_specific_ctl+0x13f1/0x15c0 /net/ipv6/datagram.c:687
 [<ffffffff85c734c3>] ip6_datagram_recv_ctl+0x33/0x40
 [<ffffffff85c0b07c>] do_ipv6_getsockopt.isra.4+0xaec/0x2150
 [<ffffffff85c0c7f6>] ipv6_getsockopt+0x116/0x230
 [<ffffffff859b5a12>] tcp_getsockopt+0x82/0xd0 /net/ipv4/tcp.c:3035
 [<ffffffff855fb385>] sock_common_getsockopt+0x95/0xd0 /net/core/sock.c:2647
 [<     inline     >] SYSC_getsockopt /net/socket.c:1776
 [<ffffffff855f8ba2>] SyS_getsockopt+0x142/0x230 /net/socket.c:1758
 [<ffffffff8685cdc5>] entry_SYSCALL_64_fastpath+0x23/0xc6
Memory state around the buggy address:
 ffff880029c84d80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff880029c84e00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> ffff880029c84e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff880029c84f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff880029c84f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

He also provided a syzkaller reproducer.

Issue is that ip6_datagram_recv_specific_ctl() expects to find IP6CB
data that was moved at a different place in tcp_v6_rcv()

This patch moves tcp_v6_restore_cb() up and calls it from
tcp_v6_do_rcv() when np->pktoptions is set.

Fixes: 971f10eca1 ("tcp: better TCP_SKB_CB layout to reduce cache line misses")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Baozeng Ding <sploving1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-13 11:07:34 -04:00
David Ahern e0d56fdd73 net: l3mdev: remove redundant calls
A previous patch added l3mdev flow update making these hooks
redundant. Remove them.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-10 23:12:52 -07:00
David S. Miller 6abdd5f593 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
All three conflicts were cases of simple overlapping
changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-30 00:54:02 -04:00
Eric Dumazet c9c3321257 tcp: add tcp_add_backlog()
When TCP operates in lossy environments (between 1 and 10 % packet
losses), many SACK blocks can be exchanged, and I noticed we could
drop them on busy senders, if these SACK blocks have to be queued
into the socket backlog.

While the main cause is the poor performance of RACK/SACK processing,
we can try to avoid these drops of valuable information that can lead to
spurious timeouts and retransmits.

Cause of the drops is the skb->truesize overestimation caused by :

- drivers allocating ~2048 (or more) bytes as a fragment to hold an
  Ethernet frame.

- various pskb_may_pull() calls bringing the headers into skb->head
  might have pulled all the frame content, but skb->truesize could
  not be lowered, as the stack has no idea of each fragment truesize.

The backlog drops are also more visible on bidirectional flows, since
their sk_rmem_alloc can be quite big.

Let's add some room for the backlog, as only the socket owner
can selectively take action to lower memory needs, like collapsing
receive queues or partial ofo pruning.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-29 00:20:24 -04:00
Eric Dumazet 72145a68e4 tcp: md5: add LINUX_MIB_TCPMD5FAILURE counter
Adds SNMP counter for drops caused by MD5 mismatches.

The current syslog might help, but a counter is more precise and helps
monitoring.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-25 16:43:11 -07:00
Eric Dumazet e65c332de8 tcp: md5: increment sk_drops on syn_recv state
TCP MD5 mismatches do increment sk_drops counter in all states but
SYN_RECV.

This is very unlikely to happen in the real world, but worth adding
to help diagnostics.

We increase the parent (listener) sk_drops.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-25 16:43:11 -07:00
Eric Dumazet 391bb6be65 ipv6: tcp: get rid of tcp_v6_clear_sk()
Now RCU lookups of IPv6 TCP sockets no longer dereference pinet6,
we do not need tcp_v6_clear_sk() anymore.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-23 23:25:29 -07:00
Eric Dumazet 20a2b49fc5 tcp: properly scale window in tcp_v[46]_reqsk_send_ack()
When sending an ack in SYN_RECV state, we must scale the offered
window if wscale option was negotiated and accepted.

Tested:
 Following packetdrill test demonstrates the issue :

0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0

+0 bind(3, ..., ...) = 0
+0 listen(3, 1) = 0

// Establish a connection.
+0 < S 0:0(0) win 20000 <mss 1000,sackOK,wscale 7, nop, TS val 100 ecr 0>
+0 > S. 0:0(0) ack 1 win 28960 <mss 1460,sackOK, TS val 100 ecr 100, nop, wscale 7>

+0 < . 1:11(10) ack 1 win 156 <nop,nop,TS val 99 ecr 100>
// check that window is properly scaled !
+0 > . 1:1(0) ack 1 win 226 <nop,nop,TS val 200 ecr 100>

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-23 16:55:49 -07:00
Linus Torvalds 7a1e8b80fb Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
 "Highlights:

   - TPM core and driver updates/fixes
   - IPv6 security labeling (CALIPSO)
   - Lots of Apparmor fixes
   - Seccomp: remove 2-phase API, close hole where ptrace can change
     syscall #"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (156 commits)
  apparmor: fix SECURITY_APPARMOR_HASH_DEFAULT parameter handling
  tpm: Add TPM 2.0 support to the Nuvoton i2c driver (NPCT6xx family)
  tpm: Factor out common startup code
  tpm: use devm_add_action_or_reset
  tpm2_i2c_nuvoton: add irq validity check
  tpm: read burstcount from TPM_STS in one 32-bit transaction
  tpm: fix byte-order for the value read by tpm2_get_tpm_pt
  tpm_tis_core: convert max timeouts from msec to jiffies
  apparmor: fix arg_size computation for when setprocattr is null terminated
  apparmor: fix oops, validate buffer size in apparmor_setprocattr()
  apparmor: do not expose kernel stack
  apparmor: fix module parameters can be changed after policy is locked
  apparmor: fix oops in profile_unpack() when policy_db is not present
  apparmor: don't check for vmalloc_addr if kvzalloc() failed
  apparmor: add missing id bounds check on dfa verification
  apparmor: allow SYS_CAP_RESOURCE to be sufficient to prlimit another task
  apparmor: use list_next_entry instead of list_entry_next
  apparmor: fix refcount race when finding a child profile
  apparmor: fix ref count leak when profile sha1 hash is read
  apparmor: check that xindex is in trans_table bounds
  ...
2016-07-29 17:38:46 -07:00
James Morris d011a4d861 Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/selinux into next 2016-07-07 10:15:34 +10:00
Eric Dumazet 19689e38ec tcp: md5: use kmalloc() backed scratch areas
Some arches have virtually mapped kernel stacks, or will soon have.

tcp_md5_hash_header() uses an automatic variable to copy tcp header
before mangling th->check and calling crypto function, which might
be problematic on such arches.

David says that using percpu storage is also problematic on non SMP
builds.

Just use kmalloc() to allocate scratch areas.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-01 04:02:55 -04:00
Huw Davies 56ac42bc94 ipv6: Allow request socks to contain IPv6 options.
If set, these will take precedence over the parent's options during
both sending and child creation.  If they're not set, the parent's
options (if any) will be used.

This is to allow the security_inet_conn_request() hook to modify the
IPv6 options in just the same way that it already may do for IPv4.

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-27 15:05:28 -04:00
Hannes Frederic Sowa 5119bd1681 ipv6: tcp: fix endianness annotation in tcp_v6_send_response
Cc: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
Fixes: 1d13a96c74 ("ipv6: tcp: fix flowlabel value in ACK messages send from TIME_WAIT")
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 15:25:35 -04:00