This patch adds a new queue (list) that tracks the sent but not yet
acked or SACKed skbs for a TCP connection. The list is chronologically
ordered by skb->skb_mstamp (the head is the oldest sent skb).

This list will be used to optimize TCP Rack recovery, which checks
an skb's timestamp to judge if it has been lost and needs to be
retransmitted. Since TCP write queue is ordered by sequence instead
of sent time, RACK has to scan over the write queue to catch all
eligible packets to detect lost retransmission, and iterates through
SACKed skbs repeatedly.

Special cares for rare events:
1. TCP repair fakes skb transmission so the send queue needs adjusted
2. SACK reneging would require re-inserting SACKed skbs into the
   send queue. For now I believe it's not worth the complexity to
   make RACK work perfectly on SACK reneging, so we do nothing here.
3. Fast Open: currently for non-TFO, send-queue correctly queues
   the pure SYN packet. For TFO which queues a pure SYN and
   then a data packet, send-queue only queues the data packet but
   not the pure SYN due to the structure of TFO code. This is okay
   because the SYN receiver would never respond with a SACK on a
   missing SYN (i.e. SYN is never fast-retransmitted by SACK/RACK).

In order to not grow sk_buff, we use an union for the new list and
_skb_refdst/destructor fields. This is a bit complicated because
we need to make sure _skb_refdst and destructor are properly zeroed
before skb is cloned/copied at transmit, and before being freed.
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>

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: NNeal Cardwell <ncardwell@google.com>
Tested-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NWei Wang <weiwan@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Acked-by: NYuchung Cheng <ycheng@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are two state fields: socket->state and sock->sk_state.  The
socket->state field uses SS_UNCONNECTED, SS_CONNECTED, etc while the
sock->sk_state typically uses values that match TCP state constants
(TCP_CLOSE, TCP_ESTABLISHED).  AF_VSOCK does not follow this convention
and instead uses SS_* constants for both fields.

The sk_state field will be exposed to userspace through the vsock_diag
interface for ss(8), netstat(8), and other programs.

This patch switches sk_state to TCP state constants so that the meaning
of this field is consistent with other address families.  Not just
AF_INET and AF_INET6 use the TCP constants, AF_UNIX and others do too.

The following mapping was used to convert the code:

  SS_FREE -> TCP_CLOSE
  SS_UNCONNECTED -> TCP_CLOSE
  SS_CONNECTING -> TCP_SYN_SENT
  SS_CONNECTED -> TCP_ESTABLISHED
  SS_DISCONNECTING -> TCP_CLOSING
  VSOCK_SS_LISTEN -> TCP_LISTEN

In __vsock_create() the sk_state initialization was dropped because
sock_init_data() already initializes sk_state to TCP_CLOSE.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The vsock_diag.ko module will need to check socket table membership.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The socket table symbols need to be exported from vsock.ko so that the
vsock_diag.ko module will be able to traverse sockets.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass extack to do_set_master and down to ndo_add_slave
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

switch the only caller to rtnl_af_unregister.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

no users in the tree.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduces RFC Draft ndata section 3.2 Priority Based
Scheduler (SCTP_SS_RR).

Works by maintaining a list of enqueued streams and tracking the last
one used to send data. When the datamsg is done, it switches to the next
stream.

See-also: https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-13Tested-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduces RFC Draft ndata section 3.4 Priority Based
Scheduler (SCTP_SS_PRIO).

It works by having a struct sctp_stream_priority for each priority
configured. This struct is then enlisted on a queue ordered per priority
if, and only if, there is a stream with data queued, so that dequeueing
is very straightforward: either finish current datamsg or simply dequeue
from the highest priority queued, which is the next stream pointed, and
that's it.

If there are multiple streams assigned with the same priority and with
data queued, it will do round robin amongst them while respecting
datamsgs boundaries (when not using idata chunks), to be reasonably
fair.

We intentionally don't maintain a list of priorities nor a list of all
streams with the same priority to save memory. The first would mean at
least 2 other pointers per priority (which, for 1000 priorities, that
can mean 16kB) and the second would also mean 2 other pointers but per
stream. As SCTP supports up to 65535 streams on a given asoc, that's
1MB. This impacts when giving a priority to some stream, as we have to
find out if the new priority is already being used and if we can free
the old one, and also when tearing down.

The new fields in struct sctp_stream_out_ext and sctp_stream are added
under a union because that memory is to be shared with other schedulers.

See-also: https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-13Tested-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduces the hooks necessary to do stream scheduling, as
per RFC Draft ndata.  It also introduces the first scheduler, which is
what we do today but now factored out: first come first served (FCFS).

With stream scheduling now we have to track which chunk was enqueued on
which stream and be able to select another other than the in front of
the main outqueue. So we introduce a list on sctp_stream_out_ext
structure for this purpose.

We reuse sctp_chunk->transmitted_list space for the list above, as the
chunk cannot belong to the two lists at the same time. By using the
union in there, we can have distinct names for these moments.

sctp_sched_ops are the operations expected to be implemented by each
scheduler. The dequeueing is a bit particular to this implementation but
it is to match how we dequeue packets today. We first dequeue and then
check if it fits the packet and if not, we requeue it at head. Thus why
we don't have a peek operation but have dequeue_done instead, which is
called once the chunk can be safely considered as transmitted.

The check removed from sctp_outq_flush is now performed by
sctp_stream_outq_migrate, which is only called during assoc setup.
(sctp_sendmsg() also checks for it)

The only operation that is foreseen but not yet added here is a way to
signalize that a new packet is starting or that the packet is done, for
round robin scheduler per packet, but is intentionally left to the
patch that actually implements it.

Support for I-DATA chunks, also described in this RFC, with user message
interleaving is straightforward as it just requires the schedulers to
probe for the feature and ignore datamsg boundaries when dequeueing.

See-also: https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-13Tested-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a helper to fetch the stream number from a given chunk.
Tested-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With the stream schedulers, sctp_stream_out will become too big to be
allocated by kmalloc and as we need to allocate with BH disabled, we
cannot use __vmalloc in sctp_stream_init().

This patch moves out the stats from sctp_stream_out to
sctp_stream_out_ext, which will be allocated only when the application
tries to sendmsg something on it.

Just the introduction of sctp_stream_out_ext would already fix the issue
described above by splitting the allocation in two. Moving the stats
to it also reduces the pressure on the allocator as we will ask for less
memory atomically when creating the socket and we will use GFP_KERNEL
later.

Then, for stream schedulers, we will just use sctp_stream_out_ext.
Tested-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make the skb parameter of skb_metadata_dst() and skb_tunnel_info()
const as they are not modified. This is in preparation for using
them in call-sites where skb is const.
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This function is unused, and furthermore it is buggy since it suffers
from the same issue that requires IP6_ECN_set_ce() to take a pointer
to the skb so that it may (in case of CHECKSUM_COMPLETE) update skb->csum

Instead of fixing it, let's just outright remove it.

Tested: builds, and 'git grep IP6_ECN_clear' comes up empty
Signed-off-by: NMaciej Żenczykowski <maze@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NHaishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NHaishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The 'publish' logic is not necessary after commit dfea2aa6 ("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: NHaishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NLuca BRUNO <lucab@debian.org>
Signed-off-by: NHaishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that the dsa_ptr is a dsa_port instance, there is no need to keep
the tag operations in the dsa_switch_tree structure. Remove it.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation to make DSA master devices point to their corresponding
CPU port instead of the whole tree, add copies of dst and rcv in the
dsa_port structure so that we keep fast access in the receive hot path.

Also keep the copies at the beginning of the dsa_port structure in order
to ensure they are available in cacheline 1.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The DSA tagging protocol operations are specific to each CPU port,
thus the dsa_device_ops pointer belongs to the dsa_port structure.

>From now on assign a slave's xmit copy from its CPU port tagging
operations. This will ease the future support for multiple CPU ports.

Also keep the tag_ops at the beginning of the dsa_port structure so that
we ensure copies for hot path are in cacheline 1.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The UDP early demux can leverate the rx dst cache even for
multicast unconnected sockets.

In such scenario the ipv4 source address is validated only on
the first packet in the given flow. After that, when we fetch
the dst entry  from the socket rx cache, we stop enforcing
the rp_filter and we even start accepting any kind of martian
addresses.

Disabling the dst cache for unconnected multicast socket will
cause large performace regression, nearly reducing by half the
max ingress tput.

Instead we factor out a route helper to completely validate an
skb source address for multicast packets and we call it from
the UDP early demux for mcast packets landing on unconnected
sockets, after successful fetching the related cached dst entry.

This still gives a measurable, but limited performance
regression:

		rp_filter = 0		rp_filter = 1
edmux disabled:	1182 Kpps		1127 Kpps
edmux before:	2238 Kpps		2238 Kpps
edmux after:	2037 Kpps		2019 Kpps

The above figures are on top of current net tree.
Applying the net-next commit 6e617de8 ("net: avoid a full
fib lookup when rp_filter is disabled.") the delta with
rp_filter == 0 will decrease even more.

Fixes: 421b3885 ("udp: ipv4: Add udp early demux")
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently no error is emitted, but this infrastructure will
used by the next patch to allow source address validation
for mcast sockets.
Since early demux can do a route lookup and an ipv4 route
lookup can return an error code this is consistent with the
current ipv4 route infrastructure.
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fib_weight in fib_info is set but not used. Remove it and the
helpers for setting it.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make the ipmr module register as a FIB notifier. To do that, implement both
the ipmr_seq_read and ipmr_dump ops.

The ipmr_seq_read op returns a sequence counter that is incremented on
every notification related operation done by the ipmr. To implement that,
add a sequence counter in the netns_ipv4 struct and increment it whenever a
new MFC route or VIF are added or deleted. The sequence operations are
protected by the RTNL lock.

The ipmr_dump iterates the list of MFC routes and the list of VIF entries
and sends notifications about them. The entries dump is done under RCU
where the VIF dump uses the mrt_lock too, as the vif->dev field can change
under RCU.
Signed-off-by: NYotam Gigi <yotamg@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order for an interface to forward packets according to the kernel
multicast routing table, it must be configured with a VIF index according
to the mroute user API. The VIF index is then used to refer to that
interface in the mroute user API, for example, to set the iif and oifs of
an MFC entry.

In order to allow drivers to be aware and offload multicast routes, they
have to be aware of the VIF add and delete notifications.

Due to the fact that a specific VIF can be deleted and re-added pointing to
another netdevice, and the MFC routes that point to it will forward the
matching packets to the new netdevice, a driver willing to offload MFC
cache entries must be aware of the VIF add and delete events in addition to
MFC routes notifications.
Signed-off-by: NYotam Gigi <yotamg@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce a helper called is_tcf_gact_pass which could be used to
tell if the action is gact pass or not.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Key length can't be negative.

Leave comparisons against nla_len() signed just in case truncated attribute
can sneak in there.

Space savings:

	add/remove: 0/0 grow/shrink: 0/7 up/down: 0/-7 (-7)
	function                                     old     new   delta
	pneigh_delete                                273     272      -1
	mlx5e_rep_netevent_event                    1415    1414      -1
	mlx5e_create_encap_header_ipv6              1194    1193      -1
	mlx5e_create_encap_header_ipv4              1071    1070      -1
	cxgb4_l2t_get                               1104    1103      -1
	__pneigh_lookup                               69      68      -1
	__neigh_create                              2452    2451      -1
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Neigh entry size can't be negative.

Space savings:

	add/remove: 0/0 grow/shrink: 0/5 up/down: 0/-7 (-7)
	function                                     old     new   delta
	lowpan_neigh_construct                        25      24      -1
	clip_seq_sub_iter                            152     151      -1
	clip_ioctl                                  1475    1474      -1
	clip_constructor                              93      92      -1
	__neigh_create                              2455    2452      -3
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When CONFIG_KASAN is enabled, the "--param asan-stack=1" causes rather large
stack frames in some functions. This goes unnoticed normally because
CONFIG_FRAME_WARN is disabled with CONFIG_KASAN by default as of commit
3f181b4d ("lib/Kconfig.debug: disable -Wframe-larger-than warnings with
KASAN=y").

The kernelci.org build bot however has the warning enabled and that led
me to investigate it a little further, as every build produces these warnings:

net/wireless/nl80211.c:4389:1: warning: the frame size of 2240 bytes is larger than 2048 bytes [-Wframe-larger-than=]
net/wireless/nl80211.c:1895:1: warning: the frame size of 3776 bytes is larger than 2048 bytes [-Wframe-larger-than=]
net/wireless/nl80211.c:1410:1: warning: the frame size of 2208 bytes is larger than 2048 bytes [-Wframe-larger-than=]
net/bridge/br_netlink.c:1282:1: warning: the frame size of 2544 bytes is larger than 2048 bytes [-Wframe-larger-than=]

Most of this problem is now solved in gcc-8, which can consolidate
the stack slots for the inline function arguments. On older compilers
we can add a workaround by declaring a local variable in each function
to pass the inline function argument.

Cc: stable@vger.kernel.org
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In linux-4.13, Wei worked hard to convert dst to a traditional
refcounted model, removing GC.

We now want to make sure a dst refcount can not transition from 0 back
to 1.

The problem here is that input path attached a not refcounted dst to an
skb. Then later, because packet is forwarded and hits skb_dst_force()
before exiting RCU section, we might try to take a refcount on one dst
that is about to be freed, if another cpu saw 1 -> 0 transition in
dst_release() and queued the dst for freeing after one RCU grace period.

Lets unify skb_dst_force() and skb_dst_force_safe(), since we should
always perform the complete check against dst refcount, and not assume
it is not zero.

Bugzilla : https://bugzilla.kernel.org/show_bug.cgi?id=197005

[  989.919496]  skb_dst_force+0x32/0x34
[  989.919498]  __dev_queue_xmit+0x1ad/0x482
[  989.919501]  ? eth_header+0x28/0xc6
[  989.919502]  dev_queue_xmit+0xb/0xd
[  989.919504]  neigh_connected_output+0x9b/0xb4
[  989.919507]  ip_finish_output2+0x234/0x294
[  989.919509]  ? ipt_do_table+0x369/0x388
[  989.919510]  ip_finish_output+0x12c/0x13f
[  989.919512]  ip_output+0x53/0x87
[  989.919513]  ip_forward_finish+0x53/0x5a
[  989.919515]  ip_forward+0x2cb/0x3e6
[  989.919516]  ? pskb_trim_rcsum.part.9+0x4b/0x4b
[  989.919518]  ip_rcv_finish+0x2e2/0x321
[  989.919519]  ip_rcv+0x26f/0x2eb
[  989.919522]  ? vlan_do_receive+0x4f/0x289
[  989.919523]  __netif_receive_skb_core+0x467/0x50b
[  989.919526]  ? tcp_gro_receive+0x239/0x239
[  989.919529]  ? inet_gro_receive+0x226/0x238
[  989.919530]  __netif_receive_skb+0x4d/0x5f
[  989.919532]  netif_receive_skb_internal+0x5c/0xaf
[  989.919533]  napi_gro_receive+0x45/0x81
[  989.919536]  ixgbe_poll+0xc8a/0xf09
[  989.919539]  ? kmem_cache_free_bulk+0x1b6/0x1f7
[  989.919540]  net_rx_action+0xf4/0x266
[  989.919543]  __do_softirq+0xa8/0x19d
[  989.919545]  irq_exit+0x5d/0x6b
[  989.919546]  do_IRQ+0x9c/0xb5
[  989.919548]  common_interrupt+0x93/0x93
[  989.919548]  </IRQ>

Similarly dst_clone() can use dst_hold() helper to have additional
debugging, as a follow up to commit 44ebe791 ("net: add debug
atomic_inc_not_zero() in dst_hold()")

In net-next we will convert dst atomic_t to refcount_t for peace of
mind.

Fixes: a4c2fd7f ("net: remove DST_NOCACHE flag")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Reported-by: NPaweł Staszewski <pstaszewski@itcare.pl>
Bisected-by: NPaweł Staszewski <pstaszewski@itcare.pl>
Acked-by: NWei Wang <weiwan@google.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

> net/ipv4/fib_frontend.c: In function 'fib_validate_source':
> net/ipv4/fib_frontend.c:411:16: error: 'struct netns_ipv4' has no member named 'fib_has_custom_local_routes'
>    if (net->ipv4.fib_has_custom_local_routes)
>                 ^
> net/ipv4/fib_frontend.c: In function 'inet_rtm_newroute':
> net/ipv4/fib_frontend.c:773:12: error: 'struct netns_ipv4' has no member named 'fib_has_custom_local_routes'
>    net->ipv4.fib_has_custom_local_routes = true;
>             ^

Fixes: 6e617de8 ("net: avoid a full fib lookup when rp_filter is disabled.")
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit 1dced6a8 ("ipv4: Restore accept_local behaviour
in fib_validate_source()") a full fib lookup is needed even if
the rp_filter is disabled, if accept_local is false - which is
the default.

What we really need in the above scenario is just checking
that the source IP address is not local, and in most case we
can do that is a cheaper way looking up the ifaddr hash table.

This commit adds a helper for such lookup, and uses it to
validate the src address when rp_filter is disabled and no
'local' routes are created by the user space in the relevant
namespace.

A new ipv4 netns flag is added to account for such routes.
We need that to preserve the same behavior we had before this
patch.

It also drops the checks to bail early from __fib_validate_source,
added by the commit 1dced6a8 ("ipv4: Restore accept_local
behaviour in fib_validate_source()") they do not give any
measurable performance improvement: if we do the lookup with are
on a slower path.

This improves UDP performances for unconnected sockets
when rp_filter is disabled by 5% and also gives small but
measurable performance improvement for TCP flood scenarios.

v1 -> v2:
 - use the ifaddr lookup helper in __ip_dev_find(), as suggested
   by Eric
 - fall-back to full lookup if custom local routes are present
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement exit_batch() method to dismantle more devices
per round.

(rtnl_lock() ...
 unregister_netdevice_many() ...
 rtnl_unlock())

Tested:
$ cat add_del_unshare.sh
for i in `seq 1 40`
do
 (for j in `seq 1 100` ; do unshare -n /bin/true >/dev/null ; done) &
done
wait ; grep net_namespace /proc/slabinfo

Before patch :
$ time ./add_del_unshare.sh
net_namespace        126    282   5504    1    2 : tunables    8    4    0 : slabdata    126    282      0

real    1m38.965s
user    0m0.688s
sys     0m37.017s

After patch:
$ time ./add_del_unshare.sh
net_namespace        135    291   5504    1    2 : tunables    8    4    0 : slabdata    135    291      0

real	0m22.117s
user	0m0.728s
sys	0m35.328s
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Having a global list of labels do not scale to thousands of
netns in the cloud era. This causes quadratic behavior on
netns creation and deletion.

This is time having a per netns list of ~10 labels.

Tested:

$ time perf record (for f in `seq 1 3000` ; do ip netns add tast$f; done)
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 3.637 MB perf.data (~158898 samples) ]

real    0m20.837s # instead of 0m24.227s
user    0m0.328s
sys     0m20.338s # instead of 0m23.753s

    16.17%       ip  [kernel.kallsyms]  [k] netlink_broadcast_filtered
    12.30%       ip  [kernel.kallsyms]  [k] netlink_has_listeners
     6.76%       ip  [kernel.kallsyms]  [k] _raw_spin_lock_irqsave
     5.78%       ip  [kernel.kallsyms]  [k] memset_erms
     5.77%       ip  [kernel.kallsyms]  [k] kobject_uevent_env
     5.18%       ip  [kernel.kallsyms]  [k] refcount_sub_and_test
     4.96%       ip  [kernel.kallsyms]  [k] _raw_read_lock
     3.82%       ip  [kernel.kallsyms]  [k] refcount_inc_not_zero
     3.33%       ip  [kernel.kallsyms]  [k] _raw_spin_unlock_irqrestore
     2.11%       ip  [kernel.kallsyms]  [k] unmap_page_range
     1.77%       ip  [kernel.kallsyms]  [k] __wake_up
     1.69%       ip  [kernel.kallsyms]  [k] strlen
     1.17%       ip  [kernel.kallsyms]  [k] __wake_up_common
     1.09%       ip  [kernel.kallsyms]  [k] insert_header
     1.04%       ip  [kernel.kallsyms]  [k] page_remove_rmap
     1.01%       ip  [kernel.kallsyms]  [k] consume_skb
     0.98%       ip  [kernel.kallsyms]  [k] netlink_trim
     0.51%       ip  [kernel.kallsyms]  [k] kernfs_link_sibling
     0.51%       ip  [kernel.kallsyms]  [k] filemap_map_pages
     0.46%       ip  [kernel.kallsyms]  [k] memcpy_erms
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

gen estimator has been rewritten in commit 1c0d32fd
("net_sched: gen_estimator: complete rewrite of rate estimators"),
the caller no longer needs to wait for a grace period. So this
patch gets rid of it.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is no need to store a copy of the master ethtool ops, storing the
original pointer in DSA and the new one in the master netdev itself is
enough.

In the meantime, set orig_ethtool_ops to NULL when restoring the master
ethtool ops and check the presence of the master original ethtool ops as
well as its needed functions before calling them.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

skb->rbnode shares space with skb->next, skb->prev and skb->tstamp

Current uses (TCP receive ofo queue and netem) need to save/restore
tstamp, while skb->dev is either NULL (TCP) or a constant for a given
queue (netem).

Since we plan using an RB tree for TCP retransmit queue to speedup SACK
processing with large BDP, this patch exchanges skb->dev and
skb->tstamp.

This saves some overhead in both TCP and netem.

v2: removes the swtstamp field from struct tcp_skb_cb
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Wei Wang <weiwan@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

remove tcp_may_send_now and tcp_snd_test that are no longer used

Fixes: 840a3cbe ("tcp: remove forward retransmit feature")
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>