Commit 45f119bf ("tcp: remove header prediction") introduced a
minor bug: the sk_state_change() and sk_wake_async() notifications for
a completed active connection happen twice: once in this new spot
inside tcp_finish_connect() and once in the existing code in
tcp_rcv_synsent_state_process() immediately after it calls
tcp_finish_connect(). This commit remoes the duplicate POLL_OUT
notifications.

Fixes: 45f119bf ("tcp: remove header prediction")
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It's convenient to init ipip offload. We will check
the return value, and print KERN_CRIT info on failure.
Signed-off-by: NTonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We're going to have capable drivers indicate route offload using the
nexthop flags, but for non-multipath routes these flags aren't dumped to
user space.

Instead, set the offload indication in the route message flags.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit c13ee2a4 ("tcp: reindent two spots after prequeue removal")
removed code in tcp_data_queue().

We can go a little farther, removing an always true test,
and removing initializers for fragstolen and eaten variables.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add new proto_ops sendmsg_locked and sendpage_locked that can be
called when the socket lock is already held. Correspondingly, add
kernel_sendmsg_locked and kernel_sendpage_locked as front end
functions.

These functions will be used in zero proxy so that we can take
the socket lock in a ULP sendmsg/sendpage and then directly call the
backend transport proto_ops functions.
Signed-off-by: NTom Herbert <tom@quantonium.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Michał reported a NULL pointer deref during fib_sync_down_dev() when
unregistering a netdevice. The problem is that we don't check for
'in_dev' being NULL, which can happen in very specific cases.

Usually routes are flushed upon NETDEV_DOWN sent in either the netdev or
the inetaddr notification chains. However, if an interface isn't
configured with any IP address, then it's possible for host routes to be
flushed following NETDEV_UNREGISTER, after NULLing dev->ip_ptr in
inetdev_destroy().

To reproduce:
$ ip link add type dummy
$ ip route add local 1.1.1.0/24 dev dummy0
$ ip link del dev dummy0

Fix this by checking for the presence of 'in_dev' before referencing it.

Fixes: 982acb97 ("ipv4: fib: Notify about nexthop status changes")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reported-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Tested-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add the following stats into SCM_TIMESTAMPING_OPT_STATS control msg:
    TCP_NLA_PACING_RATE
    TCP_NLA_DELIVERY_RATE
    TCP_NLA_SND_CWND
    TCP_NLA_REORDERING
    TCP_NLA_MIN_RTT
    TCP_NLA_RECUR_RETRANS
    TCP_NLA_DELIVERY_RATE_APP_LMT
Signed-off-by: NWei Wang <weiwan@google.com>
Acked-by: NYuchung Cheng <ycheng@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Refactor the code to extract the function to compute delivery rate.
This function will be used in later commit.
Signed-off-by: NWei Wang <weiwan@google.com>
Acked-by: NYuchung Cheng <ycheng@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

was used by tcp prequeue and header prediction.
TCPFORWARDRETRANS use was removed in january.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

re-indent tcp_ack, and remove CA_ACK_SLOWPATH; it is always set now.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Like prequeue, I am not sure this is overly useful nowadays.

If we receive a train of packets, GRO will aggregate them if the
headers are the same (HP predates GRO by several years) so we don't
get a per-packet benefit, only a per-aggregated-packet one.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Was only checked by the removed prequeue code.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These two branches are now always true, remove the conditional.
objdiff shows no changes.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

prequeue is a tcp receive optimization that moves part of rx processing
from bh to process context.

This only works if the socket being processed belongs to a process that
is blocked in recv on that socket.

In practice, this doesn't happen anymore that often because nowadays
servers tend to use an event driven (epoll) model.

Even normal client applications (web browsers) commonly use many tcp
connections in parallel.

This has measureable impact only in netperf (which uses plain recv and
thus allows prequeue use) from host to locally running vm (~4%), however,
there were no changes when using netperf between two physical hosts with
ixgbe interfaces.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When using CONFIG_UBSAN_SANITIZE_ALL, the TCP code produces a
false-positive warning:

net/ipv4/tcp_output.c: In function 'tcp_connect':
net/ipv4/tcp_output.c:2207:40: error: array subscript is below array bounds [-Werror=array-bounds]
   tp->chrono_stat[tp->chrono_type - 1] += now - tp->chrono_start;
                                        ^~
net/ipv4/tcp_output.c:2207:40: error: array subscript is below array bounds [-Werror=array-bounds]
   tp->chrono_stat[tp->chrono_type - 1] += now - tp->chrono_start;
   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

I have opened a gcc bug for this, but distros have already shipped
compilers with this problem, and it's not clear yet whether there is
a way for gcc to avoid the warning. As the problem is related to the
bitfield access, this introduces a temporary variable to store the old
enum value.

I did not notice this warning earlier, since UBSAN is disabled when
building with COMPILE_TEST, and that was always turned on in both
allmodconfig and randconfig tests.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81601Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When an early demuxed packet reaches __udp6_lib_lookup_skb(), the
sk reference is retrieved and used, but the relevant reference
count is leaked and the socket destructor is never called.
Beyond leaking the sk memory, if there are pending UDP packets
in the receive queue, even the related accounted memory is leaked.

In the long run, this will cause persistent forward allocation errors
and no UDP skbs (both ipv4 and ipv6) will be able to reach the
user-space.

Fix this by explicitly accessing the early demux reference before
the lookup, and properly decreasing the socket reference count
after usage.

Also drop the skb_steal_sock() in __udp6_lib_lookup_skb(), and
the now obsoleted comment about "socket cache".

The newly added code is derived from the current ipv4 code for the
similar path.

v1 -> v2:
  fixed the __udp6_lib_rcv() return code for resubmission,
  as suggested by Eric
Reported-by: NSam Edwards <CFSworks@gmail.com>
Reported-by: NMarc Haber <mh+netdev@zugschlus.de>
Fixes: 5425077d ("net: ipv6: Add early demux handler for UDP unicast")
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We must use pre-processor conditional block or suitable accessors to
manipulate skb->sp elsewhere builds lacking the CONFIG_XFRM will break.

Fixes: dce4551c ("udp: preserve head state for IP_CMSG_PASSSEC")
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Paul Moore reported a SELinux/IP_PASSSEC regression
caused by missing skb->sp at recvmsg() time. We need to
preserve the skb head state to process the IP_CMSG_PASSSEC
cmsg.

With this commit we avoid releasing the skb head state in the
BH even if a secpath is attached to the current skb, and stores
the skb status (with/without head states) in the scratch area,
so that we can access it at skb deallocation time, without
incurring in cache-miss penalties.

This also avoids misusing the skb CB for ipv6 packets,
as introduced by the commit 0ddf3fb2 ("udp: preserve
skb->dst if required for IP options processing").

Clean a bit the scratch area helpers implementation, to
reduce the code differences between 32 and 64 bits build.
Reported-by: NPaul Moore <paul@paul-moore.com>
Fixes: 0a463c78 ("udp: avoid a cache miss on dequeue")
Fixes: 0ddf3fb2 ("udp: preserve skb->dst if required for IP options processing")
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Tested-by: NPaul Moore <paul@paul-moore.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The last (4th) argument of tcp_rcv_established() is redundant as it
always equals to skb->len and the skb itself is always passed as 2th
agrument. There is no reason to have it.
Signed-off-by: NIlya V. Matveychikov <matvejchikov@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds a new NETDEV_UDP_TUNNEL_DROP_INFO event, similar to
NETDEV_UDP_TUNNEL_PUSH_INFO, to signal to un-offload ports.

This also adds udp_tunnel_drop_rx_port(), which calls
ndo_udp_tunnel_del.
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If NETIF_F_RX_UDP_TUNNEL_PORT was disabled on a given netdevice, skip
the tunnel offload ndo call during tunnel port creation and deletion.
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Net stack initialization currently initializes fib-trie after the
first call to netdevice_notifier() call. In fact fib_trie initialization
needs to happen before first rtnl_register(). It does not cause any problem
since there are no devices UP at this moment, but trying to bring 'lo'
UP at initialization would make this assumption wrong and exposes the issue.

Fixes following crash

 Call Trace:
  ? alternate_node_alloc+0x76/0xa0
  fib_table_insert+0x1b7/0x4b0
  fib_magic.isra.17+0xea/0x120
  fib_add_ifaddr+0x7b/0x190
  fib_netdev_event+0xc0/0x130
  register_netdevice_notifier+0x1c1/0x1d0
  ip_fib_init+0x72/0x85
  ip_rt_init+0x187/0x1e9
  ip_init+0xe/0x1a
  inet_init+0x171/0x26c
  ? ipv4_offload_init+0x66/0x66
  do_one_initcall+0x43/0x160
  kernel_init_freeable+0x191/0x219
  ? rest_init+0x80/0x80
  kernel_init+0xe/0x150
  ret_from_fork+0x22/0x30
 Code: f6 46 23 04 74 86 4c 89 f7 e8 ae 45 01 00 49 89 c7 4d 85 ff 0f 85 7b ff ff ff 31 db eb 08 4c 89 ff e8 16 47 01 00 48 8b 44 24 38 <45> 8b 6e 14 4d 63 76 74 48 89 04 24 0f 1f 44 00 00 48 83 c4 08
 RIP: kmem_cache_alloc+0xcf/0x1c0 RSP: ffff9b1500017c28
 CR2: 0000000000000014

Fixes: 7b1a74fd ("[NETNS]: Refactor fib initialization so it can handle multiple namespaces.")
Fixes: 7f9b8052 ("[IPV4]: fib hash|trie initialization")
Signed-off-by: NMahesh Bandewar <maheshb@google.com>
Acked-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adjusts the timeout formula to schedule the TCP loss probe
(TLP). The previous formula uses 2*SRTT or 1.5*RTT + DelayACKMax if
only one packet is in flight. It keeps a lower bound of 10 msec which
is too large for short RTT connections (e.g. within a data-center).
The new formula = 2*RTT + (inflight == 1 ? 200ms : 2ticks) which
performs better for short and fast connections.
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>

Eric noticed that in udp_recvmsg() we still need to access
skb->dst while processing the IP options.
Since commit 0a463c78 ("udp: avoid a cache miss on dequeue")
skb->dst is no more available at recvmsg() time and bad things
will happen if we enter the relevant code path.

This commit address the issue, avoid clearing skb->dst if
any IP options are present into the relevant skb.
Since the IP CB is contained in the first skb cacheline, we can
test it to decide to leverage the consume_stateless_skb()
optimization, without measurable additional cost in the faster
path.

v1 -> v2: updated commit message tags

Fixes: 0a463c78 ("udp: avoid a cache miss on dequeue")
Reported-by: NAndrey Konovalov <andreyknvl@google.com>
Reported-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

KMSAN reported use of uninitialized memory in skb_set_hash_from_sk(),
which originated from the TCP request socket created in
cookie_v6_check():

 ==================================================================
 BUG: KMSAN: use of uninitialized memory in tcp_transmit_skb+0xf77/0x3ec0
 CPU: 1 PID: 2949 Comm: syz-execprog Not tainted 4.11.0-rc5+ #2931
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 TCP: request_sock_TCPv6: Possible SYN flooding on port 20028. Sending cookies.  Check SNMP counters.
 Call Trace:
  <IRQ>
  __dump_stack lib/dump_stack.c:16
  dump_stack+0x172/0x1c0 lib/dump_stack.c:52
  kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:927
  __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:469
  skb_set_hash_from_sk ./include/net/sock.h:2011
  tcp_transmit_skb+0xf77/0x3ec0 net/ipv4/tcp_output.c:983
  tcp_send_ack+0x75b/0x830 net/ipv4/tcp_output.c:3493
  tcp_delack_timer_handler+0x9a6/0xb90 net/ipv4/tcp_timer.c:284
  tcp_delack_timer+0x1b0/0x310 net/ipv4/tcp_timer.c:309
  call_timer_fn+0x240/0x520 kernel/time/timer.c:1268
  expire_timers kernel/time/timer.c:1307
  __run_timers+0xc13/0xf10 kernel/time/timer.c:1601
  run_timer_softirq+0x36/0xa0 kernel/time/timer.c:1614
  __do_softirq+0x485/0x942 kernel/softirq.c:284
  invoke_softirq kernel/softirq.c:364
  irq_exit+0x1fa/0x230 kernel/softirq.c:405
  exiting_irq+0xe/0x10 ./arch/x86/include/asm/apic.h:657
  smp_apic_timer_interrupt+0x5a/0x80 arch/x86/kernel/apic/apic.c:966
  apic_timer_interrupt+0x86/0x90 arch/x86/entry/entry_64.S:489
 RIP: 0010:native_restore_fl ./arch/x86/include/asm/irqflags.h:36
 RIP: 0010:arch_local_irq_restore ./arch/x86/include/asm/irqflags.h:77
 RIP: 0010:__msan_poison_alloca+0xed/0x120 mm/kmsan/kmsan_instr.c:440
 RSP: 0018:ffff880024917cd8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
 RAX: 0000000000000246 RBX: ffff8800224c0000 RCX: 0000000000000005
 RDX: 0000000000000004 RSI: ffff880000000000 RDI: ffffea0000b6d770
 RBP: ffff880024917d58 R08: 0000000000000dd8 R09: 0000000000000004
 R10: 0000160000000000 R11: 0000000000000000 R12: ffffffff85abf810
 R13: ffff880024917dd8 R14: 0000000000000010 R15: ffffffff81cabde4
  </IRQ>
  poll_select_copy_remaining+0xac/0x6b0 fs/select.c:293
  SYSC_select+0x4b4/0x4e0 fs/select.c:653
  SyS_select+0x76/0xa0 fs/select.c:634
  entry_SYSCALL_64_fastpath+0x13/0x94 arch/x86/entry/entry_64.S:204
 RIP: 0033:0x4597e7
 RSP: 002b:000000c420037ee0 EFLAGS: 00000246 ORIG_RAX: 0000000000000017
 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004597e7
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
 RBP: 000000c420037ef0 R08: 000000c420037ee0 R09: 0000000000000059
 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000042dc20
 R13: 00000000000000f3 R14: 0000000000000030 R15: 0000000000000003
 chained origin:
  save_stack_trace+0x37/0x40 arch/x86/kernel/stacktrace.c:59
  kmsan_save_stack_with_flags mm/kmsan/kmsan.c:302
  kmsan_save_stack mm/kmsan/kmsan.c:317
  kmsan_internal_chain_origin+0x12a/0x1f0 mm/kmsan/kmsan.c:547
  __msan_store_shadow_origin_4+0xac/0x110 mm/kmsan/kmsan_instr.c:259
  tcp_create_openreq_child+0x709/0x1ae0 net/ipv4/tcp_minisocks.c:472
  tcp_v6_syn_recv_sock+0x7eb/0x2a30 net/ipv6/tcp_ipv6.c:1103
  tcp_get_cookie_sock+0x136/0x5f0 net/ipv4/syncookies.c:212
  cookie_v6_check+0x17a9/0x1b50 net/ipv6/syncookies.c:245
  tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:989
  tcp_v6_do_rcv+0xdd8/0x1c60 net/ipv6/tcp_ipv6.c:1298
  tcp_v6_rcv+0x41a3/0x4f00 net/ipv6/tcp_ipv6.c:1487
  ip6_input_finish+0x82f/0x1ee0 net/ipv6/ip6_input.c:279
  NF_HOOK ./include/linux/netfilter.h:257
  ip6_input+0x239/0x290 net/ipv6/ip6_input.c:322
  dst_input ./include/net/dst.h:492
  ip6_rcv_finish net/ipv6/ip6_input.c:69
  NF_HOOK ./include/linux/netfilter.h:257
  ipv6_rcv+0x1dbd/0x22e0 net/ipv6/ip6_input.c:203
  __netif_receive_skb_core+0x2f6f/0x3a20 net/core/dev.c:4208
  __netif_receive_skb net/core/dev.c:4246
  process_backlog+0x667/0xba0 net/core/dev.c:4866
  napi_poll net/core/dev.c:5268
  net_rx_action+0xc95/0x1590 net/core/dev.c:5333
  __do_softirq+0x485/0x942 kernel/softirq.c:284
 origin:
  save_stack_trace+0x37/0x40 arch/x86/kernel/stacktrace.c:59
  kmsan_save_stack_with_flags mm/kmsan/kmsan.c:302
  kmsan_internal_poison_shadow+0xb1/0x1a0 mm/kmsan/kmsan.c:198
  kmsan_kmalloc+0x7f/0xe0 mm/kmsan/kmsan.c:337
  kmem_cache_alloc+0x1c2/0x1e0 mm/slub.c:2766
  reqsk_alloc ./include/net/request_sock.h:87
  inet_reqsk_alloc+0xa4/0x5b0 net/ipv4/tcp_input.c:6200
  cookie_v6_check+0x4f4/0x1b50 net/ipv6/syncookies.c:169
  tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:989
  tcp_v6_do_rcv+0xdd8/0x1c60 net/ipv6/tcp_ipv6.c:1298
  tcp_v6_rcv+0x41a3/0x4f00 net/ipv6/tcp_ipv6.c:1487
  ip6_input_finish+0x82f/0x1ee0 net/ipv6/ip6_input.c:279
  NF_HOOK ./include/linux/netfilter.h:257
  ip6_input+0x239/0x290 net/ipv6/ip6_input.c:322
  dst_input ./include/net/dst.h:492
  ip6_rcv_finish net/ipv6/ip6_input.c:69
  NF_HOOK ./include/linux/netfilter.h:257
  ipv6_rcv+0x1dbd/0x22e0 net/ipv6/ip6_input.c:203
  __netif_receive_skb_core+0x2f6f/0x3a20 net/core/dev.c:4208
  __netif_receive_skb net/core/dev.c:4246
  process_backlog+0x667/0xba0 net/core/dev.c:4866
  napi_poll net/core/dev.c:5268
  net_rx_action+0xc95/0x1590 net/core/dev.c:5333
  __do_softirq+0x485/0x942 kernel/softirq.c:284
 ==================================================================

Similar error is reported for cookie_v4_check().

Fixes: 58d607d3 ("tcp: provide skb->hash to synack packets")
Signed-off-by: NAlexander Potapenko <glider@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After rcu conversions performance degradation in forward tests isn't that
noticeable anymore.

See next patch for some numbers.

A followup patcg could then also remove genid from the policies
as we do not cache bundles anymore.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

revert c386578f ("xfrm: Let the flowcache handle its size by default.").

Once we remove flow cache, we don't have a flow cache limit anymore.
We must not allow (virtually) unlimited allocations of xfrm dst entries.
Revert back to the old xfrm dst gc limits.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

flow cache is removed in next commit.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rename udp{4,6}_ufo_fragment() to udp{4,6}_tunnel_segment() and only
handle tunnel segmentation.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Such packets are no longer possible.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As discussed in Faro during Netfilter Workshop 2017, RB trees can be
used with RCU, using a seqlock.

Note that net/rxrpc/conn_service.c is already using this.

This patch converts inetpeer from AVL tree to RB tree, since it allows
to remove private AVL implementation in favor of shared RB code.

$ size net/ipv4/inetpeer.before net/ipv4/inetpeer.after
   text    data     bss     dec     hex filename
   3195      40     128    3363     d23 net/ipv4/inetpeer.before
   1562      24       0    1586     632 net/ipv4/inetpeer.after

The same technique can be used to speed up
net/netfilter/nft_set_rbtree.c (removing rwlock contention in fast path)
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

arp packets cannot be forwarded.

They can be bridged, but then they can be filtered using
either ebtables or nftables bridge family.

The bridge netfilter exposes a "call-arptables" switch which
pushes packets into arptables, but lets not expose this for nftables, so better
close this asap.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Fixes the following behavior: for connections that had no RTT sample
at the time of initializing congestion control, BBR was initializing
the pacing rate to a high nominal rate (based an a guess of RTT=1ms,
in case this is LAN traffic). Then BBR never adjusted the pacing rate
downward upon obtaining an actual RTT sample, if the connection never
filled the pipe (e.g. all sends were small app-limited writes()).

This fix adjusts the pacing rate upon obtaining the first RTT sample.

Fixes: 0f8782ea ("tcp_bbr: add BBR congestion control")
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix a corner case noticed by Eric Dumazet, where BBR's setting
sk->sk_pacing_rate to 0 during initialization could theoretically
cause packets in the sending host to hang if there were packets "in
flight" in the pacing infrastructure at the time the BBR congestion
control state is initialized. This could occur if the pacing
infrastructure happened to race with bbr_init() in a way such that the
pacer read the 0 rather than the immediately following non-zero pacing
rate.

Fixes: 0f8782ea ("tcp_bbr: add BBR congestion control")
Reported-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce a helper to initialize the BBR pacing rate unconditionally,
based on the current cwnd and RTT estimate. This is a pure refactor,
but is needed for two following fixes.

Fixes: 0f8782ea ("tcp_bbr: add BBR congestion control")
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce a helper to convert a BBR bandwidth and gain factor to a
pacing rate in bytes per second. This is a pure refactor, but is
needed for two following fixes.

Fixes: 0f8782ea ("tcp_bbr: add BBR congestion control")
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In bbr_set_pacing_rate(), which decides whether to cut the pacing
rate, there was some code that considered exiting STARTUP to be
equivalent to the notion of filling the pipe (i.e.,
bbr_full_bw_reached()). Specifically, as the code was structured,
exiting STARTUP and going into PROBE_RTT could cause us to cut the
pacing rate down to something silly and low, based on whatever
bandwidth samples we've had so far, when it's possible that all of
them have been small app-limited bandwidth samples that are not
representative of the bandwidth available in the path. (The code was
correct at the time it was written, but the state machine changed
without this spot being adjusted correspondingly.)

Fixes: 0f8782ea ("tcp_bbr: add BBR congestion control")
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some time ago David Woodhouse reported skb_under_panic
when we try to push ethernet header to fragmented ipv6 skbs.
It was fixed for ipv6 by Florian Westphal in
commit 1d325d21 ("ipv6: ip6_fragment: fix headroom tests and skb leak")

However similar problem still exist in ipv4.

It does not trigger skb_under_panic due paranoid check
in ip_finish_output2, however according to Alexey Kuznetsov
current state is abnormal and ip_fragment should be fixed too.
Signed-off-by: NVasily Averin <vvs@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ipmr_get_table() function doesn't return error pointers it returns
NULL on error.

Fixes: 4f75ba69 ("net: ipmr: Add ipmr_rtm_getroute")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>