Signed-off-by: NNikolay Borisov <kernel@kyup.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNikolay Borisov <kernel@kyup.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNikolay Borisov <kernel@kyup.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNikolay Borisov <kernel@kyup.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Refactor and consolidate cwnd and rate updates into a new function
tcp_cong_control().
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NEric Dumazet <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change enables congestion control to update cwnd based on
not only packet cumulatively acked but also packets delivered
out-of-order. This makes congestion control robust against packet
reordering because it may raise cwnd as long as packets are being
delivered once reordering has been detected (i.e., it only cares
the amount of packets delivered, not the ordering among them).
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NEric Dumazet <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A small refactoring that gets number of packets cumulatively acked
from tcp_clean_rtx_queue() directly.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NEric Dumazet <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch changes the accounting of how many packets are
newly acked or sacked when the sender receives an ACK.

The current approach basically computes

   newly_acked_sacked = (prior_packets - prior_sacked) -
                        (tp->packets_out - tp->sacked_out)

   where prior_packets and prior_sacked out are snapshot
   at the beginning of the ACK processing.

The new approach tracks the delivery information via a new
TCP state variable "delivered" which monotically increases
as new packets are delivered in order or out-of-order.

The reason for this change is that the current approach is
brittle that produces negative or inaccurate estimate.

   1) For non-SACK connections, an ACK that advances the SND.UNA
   could reset the DUPACK counters (tp->sacked_out) in
   tcp_process_loss() or tcp_fastretrans_alert(). This inflates
   the inflight suddenly and causes under-estimate or even
   negative estimate. Here is a real example:

                   before   after (processing ACK)
   packets_out     75       73
   sacked_out      23        0
   ca state        Loss     Open

   The old approach computes (75-23) - (73 - 0) = -21 delivered
   while the new approach computes 1 delivered since it
   considers the 2nd-24th packets are delivered OOO.

   2) MSS change would re-count packets_out and sacked_out so
   the estimate is in-accurate and can even become negative.
   E.g., the inflight is doubled when MSS is halved.

   3) Spurious retransmission signaled by DSACK is not accounted

The new approach is simpler and more robust. For SACK connections,
tp->delivered increments as packets are being acked or sacked in
SACK and ACK processing.

For non-sack connections, it's done in tcp_remove_reno_sacks() and
tcp_add_reno_sack(). When an ACK advances the SND.UNA, tp->delivered
is incremented by the number of packets ACKed (less the current
number of DUPACKs received plus one packet hole).  Upon receiving
a DUPACK, tp->delivered is incremented assuming one out-of-order
packet is delivered.

Upon receiving a DSACK, tp->delivered is incremtened assuming one
retransmission is delivered in tcp_sacktag_write_queue().
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NEric Dumazet <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently the cwnd is reduced and increased in various different
places. The reduction happens in various places in the recovery
state processing (tcp_fastretrans_alert) while the increase
happens afterward.

A better sequence is to identify lost packets and update
the congestion control state (icsk_ca_state) first. Then base
on the new state, up/down the cwnd in one central place. It's
more clear to reason cwnd changes.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NEric Dumazet <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The retransmission and F-RTO transmission currently happen inside
recovery state processing (tcp_fastretrans_alert) but before
congestion control.  This refactoring moves the logic after both
s.t. we can determine how much to send (cwnd) before deciding what to
send.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NEric Dumazet <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we acknowledge a FIN, it is not enough to ack the sequence number
and queue the skb into receive queue. We also have to call tcp_fin()
to properly update socket state and send proper poll() notifications.

It seems we also had the problem if we received a SYN packet with the
FIN flag set, but it does not seem an urgent issue, as no known
implementation can do that.

Fixes: 61d2bcae ("tcp: fastopen: accept data/FIN present in SYNACK message")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If we remove the SYN flag from the skbs that tcp_fastopen_add_skb()
places in socket receive queue, then we can remove the test that
tcp_recvmsg() has to perform in fast path.

All we have to do is to adjust SEQ in the slow path.

For the moment, we place an unlikely() and output a message
if we find an skb having SYN flag set.
Goal would be to get rid of the test completely.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RFC 7413 (TCP Fast Open) 4.2.2 states that the SYNACK message
MAY include data and/or FIN

This patch adds support for the client side :

If we receive a SYNACK with payload or FIN, queue the skb instead
of ignoring it.

Since we already support the same for SYN, we refactor the existing
code and reuse it. Note we need to clone the skb, so this operation
might fail under memory pressure.

Sara Dickinson pointed out FreeBSD server Fast Open implementation
was planned to generate such SYNACK in the future.

The server side might be implemented on linux later.
Reported-by: NSara Dickinson <sara@sinodun.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RFC 4015 section 3.4 says the TCP sender MUST refrain from
reversing the congestion control state when the ACK signals
congestion through the ECN-Echo flag. Currently we may not
always do that when prior_ssthresh is reset upon receiving
ACKs with ECE marks. This patch fixes that.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The fib_table_lookup function had a shift by 32 that triggered a UBSAN
warning.  This was due to the fact that I had placed the shift first and
then followed it with the check for the suffix length to ignore the
undefined behavior.  If we reorder this so that we verify the suffix is
less than 32 before shifting the value we can avoid the issue.
Reported-by: NToralf Förster <toralf.foerster@gmx.de>
Signed-off-by: NAlexander Duyck <aduyck@mirantis.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When CONFIG_PROC_FS, CONFIG_IP_PNP_BOOTP, CONFIG_IP_PNP_DHCP and
CONFIG_IP_PNP_RARP are all disabled, we get a warning about the
ic_proto_used variable being unused:

net/ipv4/ipconfig.c:146:12: error: 'ic_proto_used' defined but not used [-Werror=unused-variable]

This avoids the warning, by making the definition conditional on
whether a dynamic IP configuration protocol is configured. If not,
we know that the value is always zero, so we can optimize away the
variable and all code that depends on it.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We should not assume a valid protocol header is present,
as this is not the case for IPv4 fragments.

Lets avoid extra cache line misses and potential bugs
if we actually find a socket and incorrectly uses its dst.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With some combinations of user provided flags in netlink command,
it is possible to call tcp_get_info() with a buffer that is not 8-bytes
aligned.

It does matter on some arches, so we need to use put_unaligned() to
store the u64 fields.

Current iproute2 package does not trigger this particular issue.

Fixes: 0df48c26 ("tcp: add tcpi_bytes_acked to tcp_info")
Fixes: 977cb0ec ("tcp: add pacing_rate information into tcp_info")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This commit fixes a corner case in tcp_mark_head_lost() which was
causing the WARN_ON(len > skb->len) in tcp_fragment() to fire.

tcp_mark_head_lost() was assuming that if a packet has
tcp_skb_pcount(skb) of N, then it's safe to fragment off a prefix of
M*mss bytes, for any M < N. But with the tricky way TCP pcounts are
maintained, this is not always true.

For example, suppose the sender sends 4 1-byte packets and have the
last 3 packet sacked. It will merge the last 3 packets in the write
queue into an skb with pcount = 3 and len = 3 bytes. If another
recovery happens after a sack reneging event, tcp_mark_head_lost()
may attempt to split the skb assuming it has more than 2*MSS bytes.

This sounds very counterintuitive, but as the commit description for
the related commit c0638c24 ("tcp: don't fragment SACKed skbs in
tcp_mark_head_lost()") notes, this is because tcp_shifted_skb()
coalesces adjacent regions of SACKed skbs, and when doing this it
preserves the sum of their packet counts in order to reflect the
real-world dynamics on the wire. The c0638c24 commit tried to
avoid problems by not fragmenting SACKed skbs, since SACKed skbs are
where the non-proportionality between pcount and skb->len/mss is known
to be possible. However, that commit did not handle the case where
during a reneging event one of these weird SACKed skbs becomes an
un-SACKed skb, which tcp_mark_head_lost() can then try to fragment.

The fix is to simply mark the entire skb lost when this happens.
This makes the recovery slightly more aggressive in such corner
cases before we detect reordering. But once we detect reordering
this code path is by-passed because FACK is disabled.
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Later parts of the stack (including fragmentation) expect that there is
never a socket attached to frag in a frag_list, however this invariant
was not enforced on all defrag paths. This could lead to the
BUG_ON(skb->sk) during ip_do_fragment(), as per the call stack at the
end of this commit message.

While the call could be added to openvswitch to fix this particular
error, the head and tail of the frags list are already orphaned
indirectly inside ip_defrag(), so it seems like the remaining fragments
should all be orphaned in all circumstances.

kernel BUG at net/ipv4/ip_output.c:586!
[...]
Call Trace:
 <IRQ>
 [<ffffffffa0205270>] ? do_output.isra.29+0x1b0/0x1b0 [openvswitch]
 [<ffffffffa02167a7>] ovs_fragment+0xcc/0x214 [openvswitch]
 [<ffffffff81667830>] ? dst_discard_out+0x20/0x20
 [<ffffffff81667810>] ? dst_ifdown+0x80/0x80
 [<ffffffffa0212072>] ? find_bucket.isra.2+0x62/0x70 [openvswitch]
 [<ffffffff810e0ba5>] ? mod_timer_pending+0x65/0x210
 [<ffffffff810b732b>] ? __lock_acquire+0x3db/0x1b90
 [<ffffffffa03205a2>] ? nf_conntrack_in+0x252/0x500 [nf_conntrack]
 [<ffffffff810b63c4>] ? __lock_is_held+0x54/0x70
 [<ffffffffa02051a3>] do_output.isra.29+0xe3/0x1b0 [openvswitch]
 [<ffffffffa0206411>] do_execute_actions+0xe11/0x11f0 [openvswitch]
 [<ffffffff810b63c4>] ? __lock_is_held+0x54/0x70
 [<ffffffffa0206822>] ovs_execute_actions+0x32/0xd0 [openvswitch]
 [<ffffffffa020b505>] ovs_dp_process_packet+0x85/0x140 [openvswitch]
 [<ffffffff810b63c4>] ? __lock_is_held+0x54/0x70
 [<ffffffffa02068a2>] ovs_execute_actions+0xb2/0xd0 [openvswitch]
 [<ffffffffa020b505>] ovs_dp_process_packet+0x85/0x140 [openvswitch]
 [<ffffffffa0215019>] ? ovs_ct_get_labels+0x49/0x80 [openvswitch]
 [<ffffffffa0213a1d>] ovs_vport_receive+0x5d/0xa0 [openvswitch]
 [<ffffffff810b732b>] ? __lock_acquire+0x3db/0x1b90
 [<ffffffff810b732b>] ? __lock_acquire+0x3db/0x1b90
 [<ffffffff810b732b>] ? __lock_acquire+0x3db/0x1b90
 [<ffffffffa0214895>] ? internal_dev_xmit+0x5/0x140 [openvswitch]
 [<ffffffffa02148fc>] internal_dev_xmit+0x6c/0x140 [openvswitch]
 [<ffffffffa0214895>] ? internal_dev_xmit+0x5/0x140 [openvswitch]
 [<ffffffff81660299>] dev_hard_start_xmit+0x2b9/0x5e0
 [<ffffffff8165fc21>] ? netif_skb_features+0xd1/0x1f0
 [<ffffffff81660f20>] __dev_queue_xmit+0x800/0x930
 [<ffffffff81660770>] ? __dev_queue_xmit+0x50/0x930
 [<ffffffff810b53f1>] ? mark_held_locks+0x71/0x90
 [<ffffffff81669876>] ? neigh_resolve_output+0x106/0x220
 [<ffffffff81661060>] dev_queue_xmit+0x10/0x20
 [<ffffffff816698e8>] neigh_resolve_output+0x178/0x220
 [<ffffffff816a8e6f>] ? ip_finish_output2+0x1ff/0x590
 [<ffffffff816a8e6f>] ip_finish_output2+0x1ff/0x590
 [<ffffffff816a8cee>] ? ip_finish_output2+0x7e/0x590
 [<ffffffff816a9a31>] ip_do_fragment+0x831/0x8a0
 [<ffffffff816a8c70>] ? ip_copy_metadata+0x1b0/0x1b0
 [<ffffffff816a9ae3>] ip_fragment.constprop.49+0x43/0x80
 [<ffffffff816a9c9c>] ip_finish_output+0x17c/0x340
 [<ffffffff8169a6f4>] ? nf_hook_slow+0xe4/0x190
 [<ffffffff816ab4c0>] ip_output+0x70/0x110
 [<ffffffff816a9b20>] ? ip_fragment.constprop.49+0x80/0x80
 [<ffffffff816aa9f9>] ip_local_out+0x39/0x70
 [<ffffffff816abf89>] ip_send_skb+0x19/0x40
 [<ffffffff816abfe3>] ip_push_pending_frames+0x33/0x40
 [<ffffffff816df21a>] icmp_push_reply+0xea/0x120
 [<ffffffff816df93d>] icmp_reply.constprop.23+0x1ed/0x230
 [<ffffffff816df9ce>] icmp_echo.part.21+0x4e/0x50
 [<ffffffff810b63c4>] ? __lock_is_held+0x54/0x70
 [<ffffffff810d5f9e>] ? rcu_read_lock_held+0x5e/0x70
 [<ffffffff816dfa06>] icmp_echo+0x36/0x70
 [<ffffffff816e0d11>] icmp_rcv+0x271/0x450
 [<ffffffff816a4ca7>] ip_local_deliver_finish+0x127/0x3a0
 [<ffffffff816a4bc1>] ? ip_local_deliver_finish+0x41/0x3a0
 [<ffffffff816a5160>] ip_local_deliver+0x60/0xd0
 [<ffffffff816a4b80>] ? ip_rcv_finish+0x560/0x560
 [<ffffffff816a46fd>] ip_rcv_finish+0xdd/0x560
 [<ffffffff816a5453>] ip_rcv+0x283/0x3e0
 [<ffffffff810b6302>] ? match_held_lock+0x192/0x200
 [<ffffffff816a4620>] ? inet_del_offload+0x40/0x40
 [<ffffffff8165d062>] __netif_receive_skb_core+0x392/0xae0
 [<ffffffff8165e68e>] ? process_backlog+0x8e/0x230
 [<ffffffff810b53f1>] ? mark_held_locks+0x71/0x90
 [<ffffffff8165d7c8>] __netif_receive_skb+0x18/0x60
 [<ffffffff8165e678>] process_backlog+0x78/0x230
 [<ffffffff8165e6dd>] ? process_backlog+0xdd/0x230
 [<ffffffff8165e355>] net_rx_action+0x155/0x400
 [<ffffffff8106b48c>] __do_softirq+0xcc/0x420
 [<ffffffff816a8e87>] ? ip_finish_output2+0x217/0x590
 [<ffffffff8178e78c>] do_softirq_own_stack+0x1c/0x30
 <EOI>
 [<ffffffff8106b88e>] do_softirq+0x4e/0x60
 [<ffffffff8106b948>] __local_bh_enable_ip+0xa8/0xb0
 [<ffffffff816a8eb0>] ip_finish_output2+0x240/0x590
 [<ffffffff816a9a31>] ? ip_do_fragment+0x831/0x8a0
 [<ffffffff816a9a31>] ip_do_fragment+0x831/0x8a0
 [<ffffffff816a8c70>] ? ip_copy_metadata+0x1b0/0x1b0
 [<ffffffff816a9ae3>] ip_fragment.constprop.49+0x43/0x80
 [<ffffffff816a9c9c>] ip_finish_output+0x17c/0x340
 [<ffffffff8169a6f4>] ? nf_hook_slow+0xe4/0x190
 [<ffffffff816ab4c0>] ip_output+0x70/0x110
 [<ffffffff816a9b20>] ? ip_fragment.constprop.49+0x80/0x80
 [<ffffffff816aa9f9>] ip_local_out+0x39/0x70
 [<ffffffff816abf89>] ip_send_skb+0x19/0x40
 [<ffffffff816abfe3>] ip_push_pending_frames+0x33/0x40
 [<ffffffff816d55d3>] raw_sendmsg+0x7d3/0xc30
 [<ffffffff810b732b>] ? __lock_acquire+0x3db/0x1b90
 [<ffffffff816e7557>] ? inet_sendmsg+0xc7/0x1d0
 [<ffffffff810b63c4>] ? __lock_is_held+0x54/0x70
 [<ffffffff816e759a>] inet_sendmsg+0x10a/0x1d0
 [<ffffffff816e7495>] ? inet_sendmsg+0x5/0x1d0
 [<ffffffff8163e398>] sock_sendmsg+0x38/0x50
 [<ffffffff8163ec5f>] ___sys_sendmsg+0x25f/0x270
 [<ffffffff811aadad>] ? handle_mm_fault+0x8dd/0x1320
 [<ffffffff8178c147>] ? _raw_spin_unlock+0x27/0x40
 [<ffffffff810529b2>] ? __do_page_fault+0x1e2/0x460
 [<ffffffff81204886>] ? __fget_light+0x66/0x90
 [<ffffffff8163f8e2>] __sys_sendmsg+0x42/0x80
 [<ffffffff8163f932>] SyS_sendmsg+0x12/0x20
 [<ffffffff8178cb17>] entry_SYSCALL_64_fastpath+0x12/0x6f
Code: 00 00 44 89 e0 e9 7c fb ff ff 4c 89 ff e8 e7 e7 ff ff 41 8b 9d 80 00 00 00 2b 5d d4 89 d8 c1 f8 03 0f b7 c0 e9 33 ff ff f
 66 66 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 55 48
RIP  [<ffffffff816a9a92>] ip_do_fragment+0x892/0x8a0
 RSP <ffff88006d603170>

Fixes: 7f8a436e ("openvswitch: Add conntrack action")
Signed-off-by: NJoe Stringer <joe@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ESP algorithms using CBC mode require echainiv. Hence INET*_ESP have
to select CRYPTO_ECHAINIV in order to work properly. This solves the
issues caused by a misconfiguration as described in [1].
The original approach, patching crypto/Kconfig was turned down by
Herbert Xu [2].

[1] https://lists.strongswan.org/pipermail/users/2015-December/009074.html
[2] http://marc.info/?l=linux-crypto-vger&m=145224655809562&w=2Signed-off-by: NThomas Egerer <hakke_007@gmx.de>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are many locations that do

  if (memory_was_allocated_by_vmalloc)
    vfree(ptr);
  else
    kfree(ptr);

but kvfree() can handle both kmalloc()ed memory and vmalloc()ed memory
using is_vmalloc_addr().  Unless callers have special reasons, we can
replace this branch with kvfree().  Please check and reply if you found
problems.
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NJan Kara <jack@suse.com>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: NAndreas Dilger <andreas.dilger@intel.com>
Acked-by: N"Rafael J. Wysocki" <rjw@rjwysocki.net>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Boris Petkov <bp@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Neal reported crashes with this stack trace :

 RIP: 0010:[<ffffffff8c57231b>] tcp_v4_send_ack+0x41/0x20f
...
 CR2: 0000000000000018 CR3: 000000044005c000 CR4: 00000000001427e0
...
  [<ffffffff8c57258e>] tcp_v4_reqsk_send_ack+0xa5/0xb4
  [<ffffffff8c1a7caa>] tcp_check_req+0x2ea/0x3e0
  [<ffffffff8c19e420>] tcp_rcv_state_process+0x850/0x2500
  [<ffffffff8c1a6d21>] tcp_v4_do_rcv+0x141/0x330
  [<ffffffff8c56cdb2>] sk_backlog_rcv+0x21/0x30
  [<ffffffff8c098bbd>] tcp_recvmsg+0x75d/0xf90
  [<ffffffff8c0a8700>] inet_recvmsg+0x80/0xa0
  [<ffffffff8c17623e>] sock_aio_read+0xee/0x110
  [<ffffffff8c066fcf>] do_sync_read+0x6f/0xa0
  [<ffffffff8c0673a1>] SyS_read+0x1e1/0x290
  [<ffffffff8c5ca262>] system_call_fastpath+0x16/0x1b

The problem here is the skb we provide to tcp_v4_send_ack() had to
be parked in the backlog of a new TCP fastopen child because this child
was owned by the user at the time an out of window packet arrived.

Before queuing a packet, TCP has to set skb->dev to NULL as the device
could disappear before packet is removed from the queue.

Fix this issue by using the net pointer provided by the socket (being a
timewait or a request socket).

IPv6 is immune to the bug : tcp_v6_send_response() already gets the net
pointer from the socket if provided.

Fixes: 168a8f58 ("tcp: TCP Fast Open Server - main code path")
Reported-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Jerry Chu <hkchu@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Lorenzo reported that we could not properly find v4mapped sockets
in inet_diag_find_one_icsk(). This patch fixes the issue.
Reported-by: NLorenzo Colitti <lorenzo@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NLorenzo Colitti <lorenzo@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcp_memcontrol.c only contains legacy memory.tcp.kmem.* file definitions
and mem_cgroup->tcp_mem init/destroy stuff.  This doesn't belong to
network subsys.  Let's move it to memcontrol.c.  This also allows us to
reuse generic code for handling legacy memcg files.
Signed-off-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Let the user know that CONFIG_MEMCG_KMEM does not apply to the cgroup2
interface. This also makes legacy-only code sections stand out better.

[arnd@arndb.de: mm: memcontrol: only manage socket pressure for CONFIG_INET]
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This series adds accounting of the historical "kmem" memory consumers to
the cgroup2 memory controller.

These consumers include the dentry cache, the inode cache, kernel stack
pages, and a few others that are pointed out in patch 7/8.  The
footprint of these consumers is directly tied to userspace activity in
common workloads, and so they have to be part of the minimally viable
configuration in order to present a complete feature to our users.

The cgroup2 interface of the memory controller is far from complete, but
this series, along with the socket memory accounting series, provides
the final semantic changes for the existing memory knobs in the cgroup2
interface, which is scheduled for initial release in the next merge
window.

This patch (of 8):

Remove unused css argument frmo memcg_init_kmem()
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Using a combination of connected and un-connected sockets, Dmitry
was able to trigger soft lockups with his fuzzer.

The problem is that sockets in the SO_REUSEPORT array might have
different scores.

Right after sk2=socket(), setsockopt(sk2,...,SO_REUSEPORT, on) and
bind(sk2, ...), but _before_ the connect(sk2) is done, sk2 is added into
the soreuseport array, with a score which is smaller than the score of
first socket sk1 found in hash table (I am speaking of the regular UDP
hash table), if sk1 had the connect() done, giving a +8 to its score.

hash bucket [X] -> sk1 -> sk2 -> NULL

sk1 score = 14  (because it did a connect())
sk2 score = 6

SO_REUSEPORT fast selection is an optimization. If it turns out the
score of the selected socket does not match score of first socket, just
fallback to old SO_REUSEPORT logic instead of trying to be too smart.

Normal SO_REUSEPORT users do not mix different kind of sockets, as this
mechanism is used for load balance traffic.

Fixes: e32ea7e7 ("soreuseport: fast reuseport UDP socket selection")
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Craig Gallek <kraigatgoog@gmail.com>
Acked-by: NCraig Gallek <kraig@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Skb_gso_segment() uses skb control block during segmentation.
This patch adds 32-bytes room for previous control block which
will be copied into all resulting segments.

This patch fixes kernel crash during fragmenting forwarded packets.
Fragmentation requires valid IP CB in skb for clearing ip options.
Also patch removes custom save/restore in ovs code, now it's redundant.
Signed-off-by: NKonstantin Khlebnikov <koct9i@gmail.com>
Link: http://lkml.kernel.org/r/CALYGNiP-0MZ-FExV2HutTvE9U-QQtkKSoE--KN=JQE5STYsjAA@mail.gmail.comSigned-off-by: NDavid S. Miller <davem@davemloft.net>

According to <linux/jump_label.h> the direct use of struct static_key is
deprecated.  Update the socket and slab accounting code accordingly.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Reported-by: NJason Baron <jbaron@akamai.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The unified hierarchy memory controller is going to use this jump label
as well to control the networking callbacks.  Move it to the memory
controller code and give it a more generic name.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There won't be any separate counters for socket memory consumed by
protocols other than TCP in the future.  Remove the indirection and link
sockets directly to their owning memory cgroup.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There won't be a tcp control soft limit, so integrating the memcg code
into the global skmem limiting scheme complicates things unnecessarily.
Replace this with simple and clear charge and uncharge calls--hidden
behind a jump label--to account skb memory.

Note that this is not purely aesthetic: as a result of shoehorning the
per-memcg code into the same memory accounting functions that handle the
global level, the old code would compare the per-memcg consumption
against the smaller of the per-memcg limit and the global limit.  This
allowed the total consumption of multiple sockets to exceed the global
limit, as long as the individual sockets stayed within bounds.  After
this change, the code will always compare the per-memcg consumption to
the per-memcg limit, and the global consumption to the global limit, and
thus close this loophole.

Without a soft limit, the per-memcg memory pressure state in sockets is
generally questionable.  However, we did it until now, so we continue to
enter it when the hard limit is hit, and packets are dropped, to let
other sockets in the cgroup know that they shouldn't grow their transmit
windows, either.  However, keep it simple in the new callback model and
leave memory pressure lazily when the next packet is accepted (as
opposed to doing it synchroneously when packets are processed).  When
packets are dropped, network performance will already be in the toilet,
so that should be a reasonable trade-off.

As described above, consumption is now checked on the per-memcg level
and the global level separately.  Likewise, memory pressure states are
maintained on both the per-memcg level and the global level, and a
socket is considered under pressure when either level asserts as much.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

tcp_memcontrol replicates the global sysctl_mem limit array per cgroup,
but it only ever sets these entries to the value of the memory_allocated
page_counter limit.  Use the latter directly.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The number of allocated sockets is used for calculations in the soft
limit phase, where packets are accepted but the socket is under memory
pressure.
 Since there is no soft limit phase in tcp_memcontrol, and memory
pressure is only entered when packets are already dropped, this is
actually dead code.  Remove it.

As this is the last user of parent_cg_proto(), remove that too.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Reviewed-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move the jump-label from sock_update_memcg() and sock_release_memcg() to
the callsite, and so eliminate those function calls when socket
accounting is not enabled.

This also eliminates the need for dummy functions because the calls will
be optimized away if the Kconfig options are not enabled.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Reviewed-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are two bits defined for cg_proto->flags - MEMCG_SOCK_ACTIVATED
and MEMCG_SOCK_ACTIVE - both are set in tcp_update_limit, but the former
is never cleared while the latter can be cleared by unsetting the limit.
This allows to disable tcp socket accounting for new sockets after it
was enabled by writing -1 to memory.kmem.tcp.limit_in_bytes while still
guaranteeing that memcg_socket_limit_enabled static key will be
decremented on memcg destruction.

This functionality looks dubious, because it is not clear what a use
case would be.  By enabling tcp accounting a user accepts the price.  If
they then find the performance degradation unacceptable, they can always
restart their workload with tcp accounting disabled.  It does not seem
there is any need to flip it while the workload is running.

Besides, it contradicts to how kmem accounting API works: writing
whatever to memory.kmem.limit_in_bytes enables kmem accounting for the
cgroup in question, after which it cannot be disabled.  Therefore one
might expect that writing -1 to memory.kmem.tcp.limit_in_bytes just
enables socket accounting w/o limiting it, which might be useful by
itself, but it isn't true.

Since this API peculiarity is not documented anywhere, I propose to drop
it.  This will allow to simplify the code by dropping cg_proto->flags.
Signed-off-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit acf8dd0a ("udp: only allow UFO for packets from SOCK_DGRAM
sockets") disallows UFO for packets sent from raw sockets. We need to do
the same also for SOCK_DGRAM sockets with SO_NO_CHECK options, even if
for a bit different reason: while such socket would override the
CHECKSUM_PARTIAL set by ip_ufo_append_data(), gso_size is still set and
bad offloading flags warning is triggered in __skb_gso_segment().

In the IPv6 case, SO_NO_CHECK option is ignored but we need to disallow
UFO for packets sent by sockets with UDP_NO_CHECK6_TX option.
Signed-off-by: NMichal Kubecek <mkubecek@suse.cz>
Tested-by: NShannon Nelson <shannon.nelson@intel.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For tcp_yeah, use an ssthresh floor of 2, the same floor used by Reno
and CUBIC, per RFC 5681 (equation 4).

tcp_yeah_ssthresh() was sometimes returning a 0 or negative ssthresh
value if the intended reduction is as big or bigger than the current
cwnd. Congestion control modules should never return a zero or
negative ssthresh. A zero ssthresh generally results in a zero cwnd,
causing the connection to stall. A negative ssthresh value will be
interpreted as a u32 and will set a target cwnd for PRR near 4
billion.

Oleksandr Natalenko reported that a system using tcp_yeah with ECN
could see a warning about a prior_cwnd of 0 in
tcp_cwnd_reduction(). Testing verified that this was due to
tcp_yeah_ssthresh() misbehaving in this way.
Reported-by: NOleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is the final part required to namespaceify the tcp
keep alive mechanism.
Signed-off-by: NNikolay Borisov <kernel@kyup.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>