Commit Graph

85 Commits

Author SHA1 Message Date
Eric Dumazet 08e39c0dfa inet: move inet->defer_connect to inet->inet_flags
Make room in struct inet_sock by removing this bit field,
using one available bit in inet_flags instead.

Also move local_port_range to fill the resulting hole,
saving 8 bytes on 64bit arches.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:18 +01:00
Eric Dumazet 70f360dd70 tcp: annotate data-races around fastopenq.max_qlen
This field can be read locklessly.

Fixes: 1536e2857b ("tcp: Add a TCP_FASTOPEN socket option to get a max backlog on its listner")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-12-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20 12:34:18 -07:00
Jie Meng 8ea731d4c2 tcp: Make SYN ACK RTO tunable by BPF programs with TFO
Instead of the hardcoded TCP_TIMEOUT_INIT, this diff calls tcp_timeout_init
to initiate req->timeout like the non TFO SYN ACK case.

Tested using the following packetdrill script, on a host with a BPF
program that sets the initial connect timeout to 10ms.

`../../common/defaults.sh`

// Initialize connection
    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
   +0 setsockopt(3, SOL_TCP, TCP_FASTOPEN, [1], 4) = 0
   +0 bind(3, ..., ...) = 0
   +0 listen(3, 1) = 0

   +0 < S 0:0(0) win 32792 <mss 1000,sackOK,FO TFO_COOKIE>
   +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK>
   +.01 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK>
   +.02 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK>
   +.04 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK>
   +.01 < . 1:1(0) ack 1 win 32792

   +0 accept(3, ..., ...) = 4

Signed-off-by: Jie Meng <jmeng@fb.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-17 10:19:22 +01:00
Kuniyuki Iwashima 021266ec64 tcp: Fix data-races around sysctl_tcp_fastopen_blackhole_timeout.
While reading sysctl_tcp_fastopen_blackhole_timeout, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its readers.

Fixes: cf1ef3f071 ("net/tcp_fastopen: Disable active side TFO in certain scenarios")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18 12:21:54 +01:00
Kuniyuki Iwashima 5a54213318 tcp: Fix data-races around sysctl_tcp_fastopen.
While reading sysctl_tcp_fastopen, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 2100c8d2d9 ("net-tcp: Fast Open base")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18 12:21:54 +01:00
Mianhan Liu 222a31408a net/ipv4/tcp_fastopen.c: remove superfluous header files from tcp_fastopen.c
tcp_fastopen.c hasn't use any macro or function declared in crypto.h, err.h,
init.h, list.h, rculist.h and inetpeer.h. Thus, these files can be removed
from tcp_fastopen.c safely without affecting the compilation of the net module.

Signed-off-by: Mianhan Liu <liumh1@shanghaitech.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-20 13:09:06 +01:00
Luke Hsiao e3faa49bce tcp: enable data-less, empty-cookie SYN with TFO_SERVER_COOKIE_NOT_REQD
Since the original TFO server code was implemented in commit
168a8f5805 ("tcp: TCP Fast Open Server -
main code path") the TFO server code has supported the sysctl bit flag
TFO_SERVER_COOKIE_NOT_REQD. Currently, when the TFO_SERVER_ENABLE and
TFO_SERVER_COOKIE_NOT_REQD sysctl bit flags are set, a server connection
will accept a SYN with N bytes of data (N > 0) that has no TFO cookie,
create a new fast open connection, process the incoming data in the SYN,
and make the connection ready for accepting. After accepting, the
connection is ready for read()/recvmsg() to read the N bytes of data in
the SYN, ready for write()/sendmsg() calls and data transmissions to
transmit data.

This commit changes an edge case in this feature by changing this
behavior to apply to (N >= 0) bytes of data in the SYN rather than only
(N > 0) bytes of data in the SYN. Now, a server will accept a data-less
SYN without a TFO cookie if TFO_SERVER_COOKIE_NOT_REQD is set.

Caveat! While this enables a new kind of TFO (data-less empty-cookie
SYN), some firewall rules setup may not work if they assume such packets
are not legit TFOs and will filter them.

Signed-off-by: Luke Hsiao <lukehsiao@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20210816205105.2533289-1-luke.w.hsiao@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-16 17:25:49 -07:00
David S. Miller 5af84df962 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts are simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-23 16:13:06 +01:00
Wei Wang 213ad73d06 tcp: disable TFO blackhole logic by default
Multiple complaints have been raised from the TFO users on the internet
stating that the TFO blackhole logic is too aggressive and gets falsely
triggered too often.
(e.g. https://blog.apnic.net/2021/07/05/tcp-fast-open-not-so-fast/)
Considering that most middleboxes no longer drop TFO packets, we decide
to disable the blackhole logic by setting
/proc/sys/net/ipv4/tcp_fastopen_blackhole_timeout_set to 0 by default.

Fixes: cf1ef3f071 ("net/tcp_fastopen: Disable active side TFO in certain scenarios")
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-21 22:50:31 -07:00
Eric Dumazet e93abb840a net/tcp_fastopen: remove tcp_fastopen_ctx_lock
Remove the (per netns) spinlock in favor of xchg() atomic operations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Wei Wang <weiwan@google.com>
Link: https://lore.kernel.org/r/20210719101107.3203943-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-07-20 12:07:07 +02:00
Eric Dumazet 6f20c8adb1 net/tcp_fastopen: fix data races around tfo_active_disable_stamp
tfo_active_disable_stamp is read and written locklessly.
We need to annotate these accesses appropriately.

Then, we need to perform the atomic_inc(tfo_active_disable_times)
after the timestamp has been updated, and thus add barriers
to make sure tcp_fastopen_active_should_disable() wont read
a stale timestamp.

Fixes: cf1ef3f071 ("net/tcp_fastopen: Disable active side TFO in certain scenarios")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-19 10:11:51 -07:00
Zheng Yongjun 974d8f86cd ipv4: Fix spelling mistakes
Fix some spelling mistakes in comments:
Dont  ==> Don't
timout  ==> timeout
incomming  ==> incoming
necesarry  ==> necessary
substract  ==> subtract

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-07 14:08:30 -07:00
Martin KaFai Lau 72be0fe6ba bpf: tcp: Add bpf_skops_established()
In tcp_init_transfer(), it currently calls the bpf prog to give it a
chance to handle the just "ESTABLISHED" event (e.g. do setsockopt
on the newly established sk).  Right now, it is done by calling the
general purpose tcp_call_bpf().

In the later patch, it also needs to pass the just-received skb which
concludes the 3 way handshake. E.g. the SYNACK received at the active side.
The bpf prog can then learn some specific header options written by the
peer's bpf-prog and potentially do setsockopt on the newly established sk.
Thus, instead of reusing the general purpose tcp_call_bpf(), a new function
bpf_skops_established() is added to allow passing the "skb" to the bpf
prog.  The actual skb passing from bpf_skops_established() to the bpf prog
will happen together in a later patch which has the necessary bpf pieces.

A "skb" arg is also added to tcp_init_transfer() such that
it can then be passed to bpf_skops_established().

Calling the new bpf_skops_established() instead of tcp_call_bpf()
should be a noop in this patch.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200820190039.2884750-1-kafai@fb.com
2020-08-24 14:35:00 -07:00
Linus Torvalds a1d21081a6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:
 "Some merge window fallout, some longer term fixes:

   1) Handle headroom properly in lapbether and x25_asy drivers, from
      Xie He.

   2) Fetch MAC address from correct r8152 device node, from Thierry
      Reding.

   3) In the sw kTLS path we should allow MSG_CMSG_COMPAT in sendmsg,
      from Rouven Czerwinski.

   4) Correct fdputs in socket layer, from Miaohe Lin.

   5) Revert troublesome sockptr_t optimization, from Christoph Hellwig.

   6) Fix TCP TFO key reading on big endian, from Jason Baron.

   7) Missing CAP_NET_RAW check in nfc, from Qingyu Li.

   8) Fix inet fastreuse optimization with tproxy sockets, from Tim
      Froidcoeur.

   9) Fix 64-bit divide in new SFC driver, from Edward Cree.

  10) Add a tracepoint for prandom_u32 so that we can more easily
      perform usage analysis. From Eric Dumazet.

  11) Fix rwlock imbalance in AF_PACKET, from John Ogness"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (49 commits)
  net: openvswitch: introduce common code for flushing flows
  af_packet: TPACKET_V3: fix fill status rwlock imbalance
  random32: add a tracepoint for prandom_u32()
  Revert "ipv4: tunnel: fix compilation on ARCH=um"
  net: accept an empty mask in /sys/class/net/*/queues/rx-*/rps_cpus
  net: ethernet: stmmac: Disable hardware multicast filter
  net: stmmac: dwmac1000: provide multicast filter fallback
  ipv4: tunnel: fix compilation on ARCH=um
  vsock: fix potential null pointer dereference in vsock_poll()
  sfc: fix ef100 design-param checking
  net: initialize fastreuse on inet_inherit_port
  net: refactor bind_bucket fastreuse into helper
  net: phy: marvell10g: fix null pointer dereference
  net: Fix potential memory leak in proto_register()
  net: qcom/emac: add missed clk_disable_unprepare in error path of emac_clks_phase1_init
  ionic_lif: Use devm_kcalloc() in ionic_qcq_alloc()
  net/nfc/rawsock.c: add CAP_NET_RAW check.
  hinic: fix strncpy output truncated compile warnings
  drivers/net/wan/x25_asy: Added needed_headroom and a skb->len check
  net/tls: Fix kmap usage
  ...
2020-08-13 20:03:11 -07:00
Jason Baron f19008e676 tcp: correct read of TFO keys on big endian systems
When TFO keys are read back on big endian systems either via the global
sysctl interface or via getsockopt() using TCP_FASTOPEN_KEY, the values
don't match what was written.

For example, on s390x:

# echo "1-2-3-4" > /proc/sys/net/ipv4/tcp_fastopen_key
# cat /proc/sys/net/ipv4/tcp_fastopen_key
02000000-01000000-04000000-03000000

Instead of:

# cat /proc/sys/net/ipv4/tcp_fastopen_key
00000001-00000002-00000003-00000004

Fix this by converting to the correct endianness on read. This was
reported by Colin Ian King when running the 'tcp_fastopen_backup_key' net
selftest on s390x, which depends on the read value matching what was
written. I've confirmed that the test now passes on big and little endian
systems.

Signed-off-by: Jason Baron <jbaron@akamai.com>
Fixes: 438ac88009 ("net: fastopen: robustness and endianness fixes for SipHash")
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Eric Dumazet <edumazet@google.com>
Reported-and-tested-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-10 12:12:35 -07:00
Waiman Long 453431a549 mm, treewide: rename kzfree() to kfree_sensitive()
As said by Linus:

  A symmetric naming is only helpful if it implies symmetries in use.
  Otherwise it's actively misleading.

  In "kzalloc()", the z is meaningful and an important part of what the
  caller wants.

  In "kzfree()", the z is actively detrimental, because maybe in the
  future we really _might_ want to use that "memfill(0xdeadbeef)" or
  something. The "zero" part of the interface isn't even _relevant_.

The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.

Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.

The renaming is done by using the command sequence:

  git grep -w --name-only kzfree |\
  xargs sed -i 's/kzfree/kfree_sensitive/'

followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.

[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:22 -07:00
Jason Baron 480274787d tcp: add TCP_INFO status for failed client TFO
The TCPI_OPT_SYN_DATA bit as part of tcpi_options currently reports whether
or not data-in-SYN was ack'd on both the client and server side. We'd like
to gather more information on the client-side in the failure case in order
to indicate the reason for the failure. This can be useful for not only
debugging TFO, but also for creating TFO socket policies. For example, if
a middle box removes the TFO option or drops a data-in-SYN, we can
can detect this case, and turn off TFO for these connections saving the
extra retransmits.

The newly added tcpi_fastopen_client_fail status is 2 bits and has the
following 4 states:

1) TFO_STATUS_UNSPEC

Catch-all state which includes when TFO is disabled via black hole
detection, which is indicated via LINUX_MIB_TCPFASTOPENBLACKHOLE.

2) TFO_COOKIE_UNAVAILABLE

If TFO_CLIENT_NO_COOKIE mode is off, this state indicates that no cookie
is available in the cache.

3) TFO_DATA_NOT_ACKED

Data was sent with SYN, we received a SYN/ACK but it did not cover the data
portion. Cookie is not accepted by server because the cookie may be invalid
or the server may be overloaded.

4) TFO_SYN_RETRANSMITTED

Data was sent with SYN, we received a SYN/ACK which did not cover the data
after at least 1 additional SYN was sent (without data). It may be the case
that a middle-box is dropping data-in-SYN packets. Thus, it would be more
efficient to not use TFO on this connection to avoid extra retransmits
during connection establishment.

These new fields do not cover all the cases where TFO may fail, but other
failures, such as SYN/ACK + data being dropped, will result in the
connection not becoming established. And a connection blackhole after
session establishment shows up as a stalled connection.

Signed-off-by: Jason Baron <jbaron@akamai.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Christoph Paasch <cpaasch@apple.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-25 19:25:37 -07:00
Eric Dumazet d983ea6f16 tcp: add rcu protection around tp->fastopen_rsk
Both tcp_v4_err() and tcp_v6_err() do the following operations
while they do not own the socket lock :

	fastopen = tp->fastopen_rsk;
 	snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;

The problem is that without appropriate barrier, the compiler
might reload tp->fastopen_rsk and trigger a NULL deref.

request sockets are protected by RCU, we can simply add
the missing annotations and barriers to solve the issue.

Fixes: 168a8f5805 ("tcp: TCP Fast Open Server - main code path")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-13 10:13:08 -07:00
Ard Biesheuvel 438ac88009 net: fastopen: robustness and endianness fixes for SipHash
Some changes to the TCP fastopen code to make it more robust
against future changes in the choice of key/cookie size, etc.

- Instead of keeping the SipHash key in an untyped u8[] buffer
  and casting it to the right type upon use, use the correct
  type directly. This ensures that the key will appear at the
  correct alignment if we ever change the way these data
  structures are allocated. (Currently, they are only allocated
  via kmalloc so they always appear at the correct alignment)

- Use DIV_ROUND_UP when sizing the u64[] array to hold the
  cookie, so it is always of sufficient size, even if
  TCP_FASTOPEN_COOKIE_MAX is no longer a multiple of 8.

- Drop the 'len' parameter from the tcp_fastopen_reset_cipher()
  function, which is no longer used.

- Add endian swabbing when setting the keys and calculating the hash,
  to ensure that cookie values are the same for a given key and
  source/destination address pair regardless of the endianness of
  the server.

Note that none of these are functional changes wrt the current
state of the code, with the exception of the swabbing, which only
affects big endian systems.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-22 16:30:37 -07:00
David S. Miller 92ad6325cb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Minor SPDX change conflict.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-22 08:59:24 -04:00
Eric Dumazet 85f9aa7565 inet: clear num_timeout reqsk_alloc()
KMSAN caught uninit-value in tcp_create_openreq_child() [1]
This is caused by a recent change, combined by the fact
that TCP cleared num_timeout, num_retrans and sk fields only
when a request socket was about to be queued.

Under syncookie mode, a temporary request socket is used,
and req->num_timeout could contain garbage.

Lets clear these three fields sooner, there is really no
point trying to defer this and risk other bugs.

[1]

BUG: KMSAN: uninit-value in tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526
CPU: 1 PID: 13357 Comm: syz-executor591 Not tainted 5.2.0-rc4+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x191/0x1f0 lib/dump_stack.c:113
 kmsan_report+0x162/0x2d0 mm/kmsan/kmsan.c:611
 __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:304
 tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526
 tcp_v6_syn_recv_sock+0x761/0x2d80 net/ipv6/tcp_ipv6.c:1152
 tcp_get_cookie_sock+0x16e/0x6b0 net/ipv4/syncookies.c:209
 cookie_v6_check+0x27e0/0x29a0 net/ipv6/syncookies.c:252
 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1039 [inline]
 tcp_v6_do_rcv+0xf1c/0x1ce0 net/ipv6/tcp_ipv6.c:1344
 tcp_v6_rcv+0x60b7/0x6a30 net/ipv6/tcp_ipv6.c:1554
 ip6_protocol_deliver_rcu+0x1433/0x22f0 net/ipv6/ip6_input.c:397
 ip6_input_finish net/ipv6/ip6_input.c:438 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:447
 dst_input include/net/dst.h:439 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:272
 __netif_receive_skb_one_core net/core/dev.c:4981 [inline]
 __netif_receive_skb net/core/dev.c:5095 [inline]
 process_backlog+0x721/0x1410 net/core/dev.c:5906
 napi_poll net/core/dev.c:6329 [inline]
 net_rx_action+0x738/0x1940 net/core/dev.c:6395
 __do_softirq+0x4ad/0x858 kernel/softirq.c:293
 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052
 </IRQ>
 do_softirq kernel/softirq.c:338 [inline]
 __local_bh_enable_ip+0x199/0x1e0 kernel/softirq.c:190
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline]
 ip6_finish_output2+0x213f/0x2670 net/ipv6/ip6_output.c:117
 ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:150
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:167
 dst_output include/net/dst.h:433 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_xmit+0x1f53/0x2650 net/ipv6/ip6_output.c:271
 inet6_csk_xmit+0x3df/0x4f0 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x4076/0x5b40 net/ipv4/tcp_output.c:1156
 tcp_transmit_skb net/ipv4/tcp_output.c:1172 [inline]
 tcp_write_xmit+0x39a9/0xa730 net/ipv4/tcp_output.c:2397
 __tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2573
 tcp_send_fin+0xd43/0x1540 net/ipv4/tcp_output.c:3118
 tcp_close+0x16ba/0x1860 net/ipv4/tcp.c:2403
 inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427
 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470
 __sock_release net/socket.c:601 [inline]
 sock_close+0x156/0x490 net/socket.c:1273
 __fput+0x4c9/0xba0 fs/file_table.c:280
 ____fput+0x37/0x40 fs/file_table.c:313
 task_work_run+0x22e/0x2a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:185 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:168 [inline]
 prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:199
 syscall_return_slowpath+0x90/0x5c0 arch/x86/entry/common.c:279
 do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x401d50
Code: 01 f0 ff ff 0f 83 40 0d 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d dd 8d 2d 00 00 75 14 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 14 0d 00 00 c3 48 83 ec 08 e8 7a 02 00 00
RSP: 002b:00007fff1cf58cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000401d50
RDX: 000000000000001c RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000004a9050 R08: 0000000020000040 R09: 000000000000001c
R10: 0000000020004004 R11: 0000000000000246 R12: 0000000000402ef0
R13: 0000000000402f80 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:201 [inline]
 kmsan_internal_poison_shadow+0x53/0xa0 mm/kmsan/kmsan.c:160
 kmsan_kmalloc+0xa4/0x130 mm/kmsan/kmsan_hooks.c:177
 kmem_cache_alloc+0x534/0xb00 mm/slub.c:2781
 reqsk_alloc include/net/request_sock.h:84 [inline]
 inet_reqsk_alloc+0xa8/0x600 net/ipv4/tcp_input.c:6384
 cookie_v6_check+0xadb/0x29a0 net/ipv6/syncookies.c:173
 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1039 [inline]
 tcp_v6_do_rcv+0xf1c/0x1ce0 net/ipv6/tcp_ipv6.c:1344
 tcp_v6_rcv+0x60b7/0x6a30 net/ipv6/tcp_ipv6.c:1554
 ip6_protocol_deliver_rcu+0x1433/0x22f0 net/ipv6/ip6_input.c:397
 ip6_input_finish net/ipv6/ip6_input.c:438 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:447
 dst_input include/net/dst.h:439 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:272
 __netif_receive_skb_one_core net/core/dev.c:4981 [inline]
 __netif_receive_skb net/core/dev.c:5095 [inline]
 process_backlog+0x721/0x1410 net/core/dev.c:5906
 napi_poll net/core/dev.c:6329 [inline]
 net_rx_action+0x738/0x1940 net/core/dev.c:6395
 __do_softirq+0x4ad/0x858 kernel/softirq.c:293
 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052
 do_softirq kernel/softirq.c:338 [inline]
 __local_bh_enable_ip+0x199/0x1e0 kernel/softirq.c:190
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline]
 ip6_finish_output2+0x213f/0x2670 net/ipv6/ip6_output.c:117
 ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:150
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:167
 dst_output include/net/dst.h:433 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip6_xmit+0x1f53/0x2650 net/ipv6/ip6_output.c:271
 inet6_csk_xmit+0x3df/0x4f0 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x4076/0x5b40 net/ipv4/tcp_output.c:1156
 tcp_transmit_skb net/ipv4/tcp_output.c:1172 [inline]
 tcp_write_xmit+0x39a9/0xa730 net/ipv4/tcp_output.c:2397
 __tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2573
 tcp_send_fin+0xd43/0x1540 net/ipv4/tcp_output.c:3118
 tcp_close+0x16ba/0x1860 net/ipv4/tcp.c:2403
 inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427
 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470
 __sock_release net/socket.c:601 [inline]
 sock_close+0x156/0x490 net/socket.c:1273
 __fput+0x4c9/0xba0 fs/file_table.c:280
 ____fput+0x37/0x40 fs/file_table.c:313
 task_work_run+0x22e/0x2a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:185 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:168 [inline]
 prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:199
 syscall_return_slowpath+0x90/0x5c0 arch/x86/entry/common.c:279
 do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Fixes: 336c39a031 ("tcp: undo init congestion window on false SYNACK timeout")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-19 17:46:57 -04:00
Ard Biesheuvel c681edae33 net: ipv4: move tcp_fastopen server side code to SipHash library
Using a bare block cipher in non-crypto code is almost always a bad idea,
not only for security reasons (and we've seen some examples of this in
the kernel in the past), but also for performance reasons.

In the TCP fastopen case, we call into the bare AES block cipher one or
two times (depending on whether the connection is IPv4 or IPv6). On most
systems, this results in a call chain such as

  crypto_cipher_encrypt_one(ctx, dst, src)
    crypto_cipher_crt(tfm)->cit_encrypt_one(crypto_cipher_tfm(tfm), ...);
      aesni_encrypt
        kernel_fpu_begin();
        aesni_enc(ctx, dst, src); // asm routine
        kernel_fpu_end();

It is highly unlikely that the use of special AES instructions has a
benefit in this case, especially since we are doing the above twice
for IPv6 connections, instead of using a transform which can process
the entire input in one go.

We could switch to the cbcmac(aes) shash, which would at least get
rid of the duplicated overhead in *some* cases (i.e., today, only
arm64 has an accelerated implementation of cbcmac(aes), while x86 will
end up using the generic cbcmac template wrapping the AES-NI cipher,
which basically ends up doing exactly the above). However, in the given
context, it makes more sense to use a light-weight MAC algorithm that
is more suitable for the purpose at hand, such as SipHash.

Since the output size of SipHash already matches our chosen value for
TCP_FASTOPEN_COOKIE_SIZE, and given that it accepts arbitrary input
sizes, this greatly simplifies the code as well.

NOTE: Server farms backing a single server IP for load balancing purposes
      and sharing a single fastopen key will be adversely affected by
      this change unless all systems in the pool receive their kernel
      upgrades at the same time.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-17 13:56:26 -07:00
YueHaibing 948622f984 tcp: Make tcp_fastopen_alloc_ctx static
Fix sparse warning:

net/ipv4/tcp_fastopen.c:75:29: warning:
 symbol 'tcp_fastopen_alloc_ctx' was not declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-10 10:38:50 -07:00
Jason Baron 9092a76d3c tcp: add backup TFO key infrastructure
We would like to be able to rotate TFO keys while minimizing the number of
client cookies that are rejected. Currently, we have only one key which can
be used to generate and validate cookies, thus if we simply replace this
key clients can easily have cookies rejected upon rotation.

We propose having the ability to have both a primary key and a backup key.
The primary key is used to generate as well as to validate cookies.
The backup is only used to validate cookies. Thus, keys can be rotated as:

1) generate new key
2) add new key as the backup key
3) swap the primary and backup key, thus setting the new key as the primary

We don't simply set the new key as the primary key and move the old key to
the backup slot because the ip may be behind a load balancer and we further
allow for the fact that all machines behind the load balancer will not be
updated simultaneously.

We make use of this infrastructure in subsequent patches.

Suggested-by: Igor Lubashev <ilubashe@akamai.com>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-30 13:41:26 -07:00
Christoph Paasch 483642e5ea tcp: introduce __tcp_fastopen_cookie_gen_cipher()
Restructure __tcp_fastopen_cookie_gen() to take a 'struct crypto_cipher'
argument and rename it as __tcp_fastopen_cookie_gen_cipher(). Subsequent
patches will provide different ciphers based on which key is being used for
the cookie generation.

Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-30 13:41:26 -07:00
Yuchung Cheng 7268586baa tcp: pause Fast Open globally after third consecutive timeout
Prior to this patch, active Fast Open is paused on a specific
destination IP address if the previous connections to the
IP address have experienced recurring timeouts . But recent
experiments by Microsoft (https://goo.gl/cykmn7) and Mozilla
browsers indicate the isssue is often caused by broken middle-boxes
sitting close to the client. Therefore it is much better user
experience if Fast Open is disabled out-right globally to avoid
experiencing further timeouts on connections toward other
destinations.

This patch changes the destination-IP disablement to global
disablement if a connection experiencing recurring timeouts
or aborts due to timeout.  Repeated incidents would still
exponentially increase the pause time, starting from an hour.
This is extremely conservative but an unfortunate compromise to
minimize bad experience due to broken middle-boxes.

Reported-by: Dragana Damjanovic <ddamjanovic@mozilla.com>
Reported-by: Patrick McManus <mcmanus@ducksong.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Wei Wang <weiwan@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-13 15:51:12 -05:00
David S. Miller 2a171788ba Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Files removed in 'net-next' had their license header updated
in 'net'.  We take the remove from 'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-04 09:26:51 +09:00
Eric Dumazet 9eba935338 tcp: fix a lockdep issue in tcp_fastopen_reset_cipher()
icsk_accept_queue.fastopenq.lock is only fully initialized at listen()
time.

LOCKDEP is not happy if we attempt a spin_lock_bh() on it, because
of missing annotation. (Although kernel runs just fine)

Lets use net->ipv4.tcp_fastopen_ctx_lock to protect ctx access.

Fixes: 1fba70e5b6 ("tcp: socket option to set TCP fast open key")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-03 15:51:39 +09:00
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Christoph Paasch 71c02379c7 tcp: Configure TFO without cookie per socket and/or per route
We already allow to enable TFO without a cookie by using the
fastopen-sysctl and setting it to TFO_SERVER_COOKIE_NOT_REQD (or
TFO_CLIENT_NO_COOKIE).
This is safe to do in certain environments where we know that there
isn't a malicous host (aka., data-centers) or when the
application-protocol already provides an authentication mechanism in the
first flight of data.

A server however might be providing multiple services or talking to both
sides (public Internet and data-center). So, this server would want to
enable cookie-less TFO for certain services and/or for connections that
go to the data-center.

This patch exposes a socket-option and a per-route attribute to enable such
fine-grained configurations.

Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-24 18:48:08 +09:00
Yuchung Cheng 1fba70e5b6 tcp: socket option to set TCP fast open key
New socket option TCP_FASTOPEN_KEY to allow different keys per
listener.  The listener by default uses the global key until the
socket option is set.  The key is a 16 bytes long binary data. This
option has no effect on regular non-listener TCP sockets.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-20 13:21:36 +01:00
Eric Dumazet 18a4c0eab2 net: add rb_to_skb() and other rb tree helpers
Geeralize private netem_rb_to_skb()

TCP rtx queue will soon be converted to rb-tree,
so we will need skb_rbtree_walk() helpers.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07 00:28:53 +01:00
Wei Wang 27204aaa9d tcp: uniform the set up of sockets after successful connection
Currently in the TCP code, the initialization sequence for cached
metrics, congestion control, BPF, etc, after successful connection
is very inconsistent. This introduces inconsistent bevhavior and is
prone to bugs. The current call sequence is as follows:

(1) for active case (tcp_finish_connect() case):
        tcp_mtup_init(sk);
        icsk->icsk_af_ops->rebuild_header(sk);
        tcp_init_metrics(sk);
        tcp_call_bpf(sk, BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB);
        tcp_init_congestion_control(sk);
        tcp_init_buffer_space(sk);

(2) for passive case (tcp_rcv_state_process() TCP_SYN_RECV case):
        icsk->icsk_af_ops->rebuild_header(sk);
        tcp_call_bpf(sk, BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB);
        tcp_init_congestion_control(sk);
        tcp_mtup_init(sk);
        tcp_init_buffer_space(sk);
        tcp_init_metrics(sk);

(3) for TFO passive case (tcp_fastopen_create_child()):
        inet_csk(child)->icsk_af_ops->rebuild_header(child);
        tcp_init_congestion_control(child);
        tcp_mtup_init(child);
        tcp_init_metrics(child);
        tcp_call_bpf(child, BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB);
        tcp_init_buffer_space(child);

This commit uniforms the above functions to have the following sequence:
        tcp_mtup_init(sk);
        icsk->icsk_af_ops->rebuild_header(sk);
        tcp_init_metrics(sk);
        tcp_call_bpf(sk, BPF_SOCK_OPS_ACTIVE/PASSIVE_ESTABLISHED_CB);
        tcp_init_congestion_control(sk);
        tcp_init_buffer_space(sk);
This sequence is the same as the (1) active case. We pick this sequence
because this order correctly allows BPF to override the settings
including congestion control module and initial cwnd, etc from
the route, and then allows the CC module to see those settings.

Suggested-by: Neal Cardwell <ncardwell@google.com>
Tested-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-05 21:10:16 -07:00
Haishuang Yan 3733be14a3 ipv4: Namespaceify tcp_fastopen_blackhole_timeout knob
Different namespace application might require different time period in
second to disable Fastopen on active TCP sockets.

Tested:
Simulate following 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]

And then print netstat of TCPFastOpenBlackhole, the counter increased as
expected when the firewall blackhole issue is detected and active TFO is
disabled.
# cat /proc/net/netstat | awk '{print $91}'
TCPFastOpenBlackhole
1

Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-01 17:55:54 -07:00
Haishuang Yan 4371384856 ipv4: Namespaceify tcp_fastopen_key knob
Different namespace application might require different tcp_fastopen_key
independently of the host.

David Miller pointed out there is a leak without releasing the context
of tcp_fastopen_key during netns teardown. So add the release action in
exit_batch path.

Tested:
1. Container namespace:
# cat /proc/sys/net/ipv4/tcp_fastopen_key:
2817fff2-f803cf97-eadfd1f3-78c0992b

cookie key in tcp syn packets:
Fast Open Cookie
    Kind: TCP Fast Open Cookie (34)
    Length: 10
    Fast Open Cookie: 1e5dd82a8c492ca9

2. Host:
# cat /proc/sys/net/ipv4/tcp_fastopen_key:
107d7c5f-68eb2ac7-02fb06e6-ed341702

cookie key in tcp syn packets:
Fast Open Cookie
    Kind: TCP Fast Open Cookie (34)
    Length: 10
    Fast Open Cookie: e213c02bf0afbc8a

Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-01 17:55:54 -07:00
Haishuang Yan dd000598a3 ipv4: Remove the 'publish' logic in tcp_fastopen_init_key_once
The 'publish' logic is not necessary after commit dfea2aa654 ("tcp:
Do not call tcp_fastopen_reset_cipher from interrupt context"), because
in tcp_fastopen_cookie_gen,it wouldn't call tcp_fastopen_init_key_once.

Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-01 17:55:54 -07:00
Haishuang Yan e1cfcbe82b ipv4: Namespaceify tcp_fastopen knob
Different namespace application might require enable TCP Fast Open
feature independently of the host.

This patch series continues making more of the TCP Fast Open related
sysctl knobs be per net-namespace.

Reported-by: Luca BRUNO <lucab@debian.org>
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-01 17:55:54 -07:00
Tonghao Zhang 1119936927 tcp: Remove the unused parameter for tcp_try_fastopen.
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-22 14:16:12 -07:00
Lawrence Brakmo 9872a4bde3 bpf: Add TCP connection BPF callbacks
Added callbacks to BPF SOCK_OPS type program before an active
connection is intialized and after a passive or active connection is
established.

The following patch demostrates how they can be used to set send and
receive buffer sizes.

Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01 16:15:14 -07:00
Reshetova, Elena 41c6d650f6 net: convert sock.sk_refcnt from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

This patch uses refcount_inc_not_zero() instead of
atomic_inc_not_zero_hint() due to absense of a _hint()
version of refcount API. If the hint() version must
be used, we might need to revisit API.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01 07:39:08 -07:00
Wei Wang 46c2fa3987 net/tcp_fastopen: Add snmp counter for blackhole detection
This counter records the number of times the firewall blackhole issue is
detected and active TFO is disabled.

Signed-off-by: Wei Wang <weiwan@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>
2017-04-24 14:27:17 -04:00
Wei Wang cf1ef3f071 net/tcp_fastopen: Disable active side TFO in certain scenarios
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: Wei Wang <weiwan@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>
2017-04-24 14:27:17 -04:00
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
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 065263f40f net/tcp-fastopen: refactor cookie check logic
Refactor the cookie check logic in tcp_send_syn_data() into a function.
This function will be called else where in later changes.

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
Alexey Kodanev 0dbd7ff3ac tcp: initialize max window for a new fastopen socket
Found that if we run LTP netstress test with large MSS (65K),
the first attempt from server to send data comparable to this
MSS on fastopen connection will be delayed by the probe timer.

Here is an example:

     < S  seq 0:0 win 43690 options [mss 65495 wscale 7 tfo cookie] length 32
     > S. seq 0:0 ack 1 win 43690 options [mss 65495 wscale 7] length 0
     < .  ack 1 win 342 length 0

Inside tcp_sendmsg(), tcp_send_mss() returns max MSS in 'mss_now',
as well as in 'size_goal'. This results the segment not queued for
transmition until all the data copied from user buffer. Then, inside
__tcp_push_pending_frames(), it breaks on send window test and
continues with the check probe timer.

Fragmentation occurs in tcp_write_wakeup()...

+0.2 > P. seq 1:43777 ack 1 win 342 length 43776
     < .  ack 43777, win 1365 length 0
     > P. seq 43777:65001 ack 1 win 342 options [...] length 21224
     ...

This also contradicts with the fact that we should bound to the half
of the window if it is large.

Fix this flaw by correctly initializing max_window. Before that, it
could have large values that affect further calculations of 'size_goal'.

Fixes: 168a8f5805 ("tcp: TCP Fast Open Server - main code path")
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>
2017-01-19 11:35:26 -05:00
Shannon Nelson 003c941057 tcp: fix tcp_fastopen unaligned access complaints on sparc
Fix up a data alignment issue on sparc by swapping the order
of the cookie byte array field with the length field in
struct tcp_fastopen_cookie, and making it a proper union
to clean up the typecasting.

This addresses log complaints like these:
    log_unaligned: 113 callbacks suppressed
    Kernel unaligned access at TPC[976490] tcp_try_fastopen+0x2d0/0x360
    Kernel unaligned access at TPC[9764ac] tcp_try_fastopen+0x2ec/0x360
    Kernel unaligned access at TPC[9764c8] tcp_try_fastopen+0x308/0x360
    Kernel unaligned access at TPC[9764e4] tcp_try_fastopen+0x324/0x360
    Kernel unaligned access at TPC[976490] tcp_try_fastopen+0x2d0/0x360

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Shannon Nelson <shannon.nelson@oracle.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-13 12:31:24 -05:00
Eric Dumazet 76061f631c tcp: fastopen: avoid negative sk_forward_alloc
When DATA and/or FIN are carried in a SYN/ACK message or SYN message,
we append an skb in socket receive queue, but we forget to call
sk_forced_mem_schedule().

Effect is that the socket has a negative sk->sk_forward_alloc as long as
the message is not read by the application.

Josh Hunt fixed a similar issue in commit d22e153718 ("tcp: fix tcp
fin memory accounting")

Fixes: 168a8f5805 ("tcp: TCP Fast Open Server - main code path")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Josh Hunt <johunt@akamai.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-08 16:08:10 -07:00
Neal Cardwell 28b346cbc0 tcp: fastopen: fix rcv_wup initialization for TFO server on SYN/data
Yuchung noticed that on the first TFO server data packet sent after
the (TFO) handshake, the server echoed the TCP timestamp value in the
SYN/data instead of the timestamp value in the final ACK of the
handshake. This problem did not happen on regular opens.

The tcp_replace_ts_recent() logic that decides whether to remember an
incoming TS value needs tp->rcv_wup to hold the latest receive
sequence number that we have ACKed (latest tp->rcv_nxt we have
ACKed). This commit fixes this issue by ensuring that a TFO server
properly updates tp->rcv_wup to match tp->rcv_nxt at the time it sends
a SYN/ACK for the SYN/data.

Reported-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Fixes: 168a8f5805 ("tcp: TCP Fast Open Server - main code path")
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-01 16:40:15 -07:00
Eric Dumazet c10d9310ed tcp: do not assume TCP code is non preemptible
We want to to make TCP stack preemptible, as draining prequeue
and backlog queues can take lot of time.

Many SNMP updates were assuming that BH (and preemption) was disabled.

Need to convert some __NET_INC_STATS() calls to NET_INC_STATS()
and some __TCP_INC_STATS() to TCP_INC_STATS()

Before using this_cpu_ptr(net->ipv4.tcp_sk) in tcp_v4_send_reset()
and tcp_v4_send_ack(), we add an explicit preempt disabled section.

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>
2016-05-02 17:02:25 -04:00