We now have proper per-listener but also per network namespace counters
for SYN packets that might be dropped.

We replace the kfree_skb() by consume_skb() to be drop monitor [1]
friendly, and remove an obsolete comment.
FastOpen SYN packets can carry payload in them just fine.

[1] perf record -a -g -e skb:kfree_skb sleep 1; perf report
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

d894ba18 ("soreuseport: fix ordering for mixed v4/v6 sockets")
was merged as a bug fix to the net tree.  Two conflicting changes
were committed to net-next before the above fix was merged back to
net-next:
ca065d0c ("udp: no longer use SLAB_DESTROY_BY_RCU")
3b24d854 ("tcp/dccp: do not touch listener sk_refcnt under synflood")

These changes switched the datastructure used for TCP and UDP sockets
from hlist_nulls to hlist.  This patch applies the necessary parts
of the net tree fix to net-next which were not automatic as part of the
merge.

Fixes: 1602f49b ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net")
Signed-off-by: NCraig Gallek <kraig@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Linux TCP stack painfully segments all TSO/GSO packets before retransmits.

This was fine back in the days when TSO/GSO were emerging, with their
bugs, but we believe the dark age is over.

Keeping big packets in write queues, but also in stack traversal
has a lot of benefits.
 - Less memory overhead, because write queues have less skbs
 - Less cpu overhead at ACK processing.
 - Better SACK processing, as lot of studies mentioned how
   awful linux was at this ;)
 - Less cpu overhead to send the rtx packets
   (IP stack traversal, netfilter traversal, drivers...)
 - Better latencies in presence of losses.
 - Smaller spikes in fq like packet schedulers, as retransmits
   are not constrained by TCP Small Queues.

1 % packet losses are common today, and at 100Gbit speeds, this
translates to ~80,000 losses per second.
Losses are often correlated, and we see many retransmit events
leading to 1-MSS train of packets, at the time hosts are already
under stress.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 42b18f60 ("tipc: refactor function tipc_link_timeout()"),
introduced a bug which prevents sending of probe messages during
link synchronization phase. This leads to hanging links, if the
bearer is disabled/enabled after links are up.

In this commit, we send the probe messages correctly.

Fixes: 42b18f60 ("tipc: refactor function tipc_link_timeout()")
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When collapsing skbs, txstamp_ack also needs to be merged.

Retrans Collapse Test:
~~~~~~
0.200 accept(3, ..., ...) = 4
+0 setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = 0

0.200 write(4, ..., 730) = 730
+0 setsockopt(4, SOL_SOCKET, 37, [2688], 4) = 0
0.200 write(4, ..., 730) = 730
+0 setsockopt(4, SOL_SOCKET, 37, [2176], 4) = 0
0.200 write(4, ..., 11680) = 11680

0.200 > P. 1:731(730) ack 1
0.200 > P. 731:1461(730) ack 1
0.200 > . 1461:8761(7300) ack 1
0.200 > P. 8761:13141(4380) ack 1

0.300 < . 1:1(0) ack 1 win 257 <sack 1461:2921,nop,nop>
0.300 < . 1:1(0) ack 1 win 257 <sack 1461:4381,nop,nop>
0.300 < . 1:1(0) ack 1 win 257 <sack 1461:5841,nop,nop>
0.300 > P. 1:1461(1460) ack 1
0.400 < . 1:1(0) ack 13141 win 257

BPF Output Before:
~~~~~
<No output due to missing SCM_TSTAMP_ACK timestamp>

BPF Output After:
~~~~~
<...>-2027  [007] d.s.    79.765921: : ee_data:1459

Sacks Collapse Test:
~~~~~
0.200 accept(3, ..., ...) = 4
+0 setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = 0

0.200 write(4, ..., 1460) = 1460
+0 setsockopt(4, SOL_SOCKET, 37, [2688], 4) = 0
0.200 write(4, ..., 13140) = 13140
+0 setsockopt(4, SOL_SOCKET, 37, [2176], 4) = 0

0.200 > P. 1:1461(1460) ack 1
0.200 > . 1461:8761(7300) ack 1
0.200 > P. 8761:14601(5840) ack 1

0.300 < . 1:1(0) ack 1 win 257 <sack 1461:14601,nop,nop>
0.300 > P. 1:1461(1460) ack 1
0.400 < . 1:1(0) ack 14601 win 257

BPF Output Before:
~~~~~
<No output due to missing SCM_TSTAMP_ACK timestamp>

BPF Output After:
~~~~~
<...>-2049  [007] d.s.    89.185538: : ee_data:14599
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Tested-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a tcp skb is sliced into two smaller skbs (e.g. in
tcp_fragment() and tso_fragment()),  it does not carry
the txstamp_ack bit to the newly created skb if it is needed.
The end result is a timestamping event (SCM_TSTAMP_ACK) will
be missing from the sk->sk_error_queue.

This patch carries this bit to the new skb2
in tcp_fragment_tstamp().

BPF Output Before:
~~~~~~
<No output due to missing SCM_TSTAMP_ACK timestamp>

BPF Output After:
~~~~~~
<...>-2050  [000] d.s.   100.928763: : ee_data:14599

Packetdrill Script:
~~~~~~
+0 `sysctl -q -w net.ipv4.tcp_min_tso_segs=10`
+0 `sysctl -q -w net.ipv4.tcp_no_metrics_save=1`
+0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+0 bind(3, ..., ...) = 0
+0 listen(3, 1) = 0

0.100 < S 0:0(0) win 32792 <mss 1460,sackOK,nop,nop,nop,wscale 7>
0.100 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 7>
0.200 < . 1:1(0) ack 1 win 257
0.200 accept(3, ..., ...) = 4
+0 setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = 0

+0 setsockopt(4, SOL_SOCKET, 37, [2688], 4) = 0
0.200 write(4, ..., 14600) = 14600
+0 setsockopt(4, SOL_SOCKET, 37, [2176], 4) = 0

0.200 > . 1:7301(7300) ack 1
0.200 > P. 7301:14601(7300) ack 1

0.300 < . 1:1(0) ack 14601 win 257

0.300 close(4) = 0
0.300 > F. 14601:14601(0) ack 1
0.400 < F. 1:1(0) ack 16062 win 257
0.400 > . 14602:14602(0) ack 2
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Tested-by: NSoheil Hassas Yeganeh <soheil@google.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

nla_data() is now aligned on a 64-bit area.
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

nla_data() is now aligned on a 64-bit area.

A temporary version (nla_put_be64_32bit()) is added for nla_put_net64().
This function is removed in the next patch.
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

nla_data() is now aligned on a 64-bit area.
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When using masked actions the ipv6_proto field of an action
to set IPv6 fields may be zero rather than the prevailing protocol
which will result in skipping checksum recalculation.

This patch resolves the problem by relying on the protocol
in the flow key rather than that in the set field action.

Fixes: 83d2b9ba ("net: openvswitch: Support masked set actions.")
Cc: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds support for NETIF_F_TSO_MANGLEID if a given tunnel supports
NETIF_F_TSO.  This way if needed a device can then later enable the TSO
with IP ID mangling and the tunnels on top of that device can then also
make use of the IP ID mangling as well.
Signed-off-by: NAlexander Duyck <aduyck@mirantis.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After receiving sacks, tcp_shifted_skb() will collapse
skbs if possible.  tx_flags and tskey also have to be
merged.

This patch reuses the tcp_skb_collapse_tstamp() to handle
them.

BPF Output Before:
~~~~~
<no-output-due-to-missing-tstamp-event>

BPF Output After:
~~~~~
<...>-2024  [007] d.s.    88.644374: : ee_data:14599

Packetdrill Script:
~~~~~
+0 `sysctl -q -w net.ipv4.tcp_min_tso_segs=10`
+0 `sysctl -q -w net.ipv4.tcp_no_metrics_save=1`
+0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+0 bind(3, ..., ...) = 0
+0 listen(3, 1) = 0

0.100 < S 0:0(0) win 32792 <mss 1460,sackOK,nop,nop,nop,wscale 7>
0.100 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 7>
0.200 < . 1:1(0) ack 1 win 257
0.200 accept(3, ..., ...) = 4
+0 setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = 0

0.200 write(4, ..., 1460) = 1460
+0 setsockopt(4, SOL_SOCKET, 37, [2688], 4) = 0
0.200 write(4, ..., 13140) = 13140

0.200 > P. 1:1461(1460) ack 1
0.200 > . 1461:8761(7300) ack 1
0.200 > P. 8761:14601(5840) ack 1

0.300 < . 1:1(0) ack 1 win 257 <sack 1461:14601,nop,nop>
0.300 > P. 1:1461(1460) ack 1
0.400 < . 1:1(0) ack 14601 win 257

0.400 close(4) = 0
0.400 > F. 14601:14601(0) ack 1
0.500 < F. 1:1(0) ack 14602 win 257
0.500 > . 14602:14602(0) ack 2
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Tested-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If two skbs are merged/collapsed during retransmission, the current
logic does not merge the tx_flags and tskey.  The end result is
the SCM_TSTAMP_ACK timestamp could be missing for a packet.

The patch:
1. Merge the tx_flags
2. Overwrite the prev_skb's tskey with the next_skb's tskey

BPF Output Before:
~~~~~~
<no-output-due-to-missing-tstamp-event>

BPF Output After:
~~~~~~
packetdrill-2092  [001] d.s.   453.998486: : ee_data:1459

Packetdrill Script:
~~~~~~
+0 `sysctl -q -w net.ipv4.tcp_min_tso_segs=10`
+0 `sysctl -q -w net.ipv4.tcp_no_metrics_save=1`
+0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+0 bind(3, ..., ...) = 0
+0 listen(3, 1) = 0

0.100 < S 0:0(0) win 32792 <mss 1460,sackOK,nop,nop,nop,wscale 7>
0.100 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 7>
0.200 < . 1:1(0) ack 1 win 257
0.200 accept(3, ..., ...) = 4
+0 setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = 0

0.200 write(4, ..., 730) = 730
+0 setsockopt(4, SOL_SOCKET, 37, [2688], 4) = 0
0.200 write(4, ..., 730) = 730
+0 setsockopt(4, SOL_SOCKET, 37, [2176], 4) = 0
0.200 write(4, ..., 11680) = 11680
+0 setsockopt(4, SOL_SOCKET, 37, [2688], 4) = 0

0.200 > P. 1:731(730) ack 1
0.200 > P. 731:1461(730) ack 1
0.200 > . 1461:8761(7300) ack 1
0.200 > P. 8761:13141(4380) ack 1

0.300 < . 1:1(0) ack 1 win 257 <sack 1461:2921,nop,nop>
0.300 < . 1:1(0) ack 1 win 257 <sack 1461:4381,nop,nop>
0.300 < . 1:1(0) ack 1 win 257 <sack 1461:5841,nop,nop>
0.300 > P. 1:1461(1460) ack 1
0.400 < . 1:1(0) ack 13141 win 257

0.400 close(4) = 0
0.400 > F. 13141:13141(0) ack 1
0.500 < F. 1:1(0) ack 13142 win 257
0.500 > . 13142:13142(0) ack 2
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Tested-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Removed .type field from NLA to do proper length checking.
Reported by Daniel Borkmann and Julia Lawall.
Signed-off-by: NPeter Heise <peter.heise@airbus.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

EXPIRES_IN_MS macro comes from net/ipv4/inet_diag.c and dates
back to before jiffies_to_msecs() has been introduced.

Now we can remove it and use jiffies_to_msecs().
Suggested-by: NJakub Sitnicki <jkbs@redhat.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NJakub Sitnicki <jkbs@redhat.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Assuming SOF_TIMESTAMPING_TX_ACK is on. When dup acks are received,
it could incorrectly think that a skb has already
been acked and queue a SCM_TSTAMP_ACK cmsg to the
sk->sk_error_queue.

In tcp_ack_tstamp(), it checks
'between(shinfo->tskey, prior_snd_una, tcp_sk(sk)->snd_una - 1)'.
If prior_snd_una == tcp_sk(sk)->snd_una like the following packetdrill
script, between() returns true but the tskey is actually not acked.
e.g. try between(3, 2, 1).

The fix is to replace between() with one before() and one !before().
By doing this, the -1 offset on the tcp_sk(sk)->snd_una can also be
removed.

A packetdrill script is used to reproduce the dup ack scenario.
Due to the lacking cmsg support in packetdrill (may be I
cannot find it),  a BPF prog is used to kprobe to
sock_queue_err_skb() and print out the value of
serr->ee.ee_data.

Both the packetdrill and the bcc BPF script is attached at the end of
this commit message.

BPF Output Before Fix:
~~~~~~
      <...>-2056  [001] d.s.   433.927987: : ee_data:1459  #incorrect
packetdrill-2056  [001] d.s.   433.929563: : ee_data:1459  #incorrect
packetdrill-2056  [001] d.s.   433.930765: : ee_data:1459  #incorrect
packetdrill-2056  [001] d.s.   434.028177: : ee_data:1459
packetdrill-2056  [001] d.s.   434.029686: : ee_data:14599

BPF Output After Fix:
~~~~~~
      <...>-2049  [000] d.s.   113.517039: : ee_data:1459
      <...>-2049  [000] d.s.   113.517253: : ee_data:14599

BCC BPF Script:
~~~~~~
#!/usr/bin/env python

from __future__ import print_function
from bcc import BPF

bpf_text = """
#include <uapi/linux/ptrace.h>
#include <net/sock.h>
#include <bcc/proto.h>
#include <linux/errqueue.h>

#ifdef memset
#undef memset
#endif

int trace_err_skb(struct pt_regs *ctx)
{
	struct sk_buff *skb = (struct sk_buff *)ctx->si;
	struct sock *sk = (struct sock *)ctx->di;
	struct sock_exterr_skb *serr;
	u32 ee_data = 0;

	if (!sk || !skb)
		return 0;

	serr = SKB_EXT_ERR(skb);
	bpf_probe_read(&ee_data, sizeof(ee_data), &serr->ee.ee_data);
	bpf_trace_printk("ee_data:%u\\n", ee_data);

	return 0;
};
"""

b = BPF(text=bpf_text)
b.attach_kprobe(event="sock_queue_err_skb", fn_name="trace_err_skb")
print("Attached to kprobe")
b.trace_print()

Packetdrill Script:
~~~~~~
+0 `sysctl -q -w net.ipv4.tcp_min_tso_segs=10`
+0 `sysctl -q -w net.ipv4.tcp_no_metrics_save=1`
+0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+0 bind(3, ..., ...) = 0
+0 listen(3, 1) = 0

0.100 < S 0:0(0) win 32792 <mss 1460,sackOK,nop,nop,nop,wscale 7>
0.100 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 7>
0.200 < . 1:1(0) ack 1 win 257
0.200 accept(3, ..., ...) = 4
+0 setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = 0

+0 setsockopt(4, SOL_SOCKET, 37, [2688], 4) = 0
0.200 write(4, ..., 1460) = 1460
0.200 write(4, ..., 13140) = 13140

0.200 > P. 1:1461(1460) ack 1
0.200 > . 1461:8761(7300) ack 1
0.200 > P. 8761:14601(5840) ack 1

0.300 < . 1:1(0) ack 1 win 257 <sack 1461:2921,nop,nop>
0.300 < . 1:1(0) ack 1 win 257 <sack 1461:4381,nop,nop>
0.300 < . 1:1(0) ack 1 win 257 <sack 1461:5841,nop,nop>
0.300 > P. 1:1461(1460) ack 1
0.400 < . 1:1(0) ack 14601 win 257

0.400 close(4) = 0
0.400 > F. 14601:14601(0) ack 1
0.500 < F. 1:1(0) ack 14602 win 257
0.500 > . 14602:14602(0) ack 2
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Soheil Hassas Yeganeh <soheil.kdev@gmail.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Tested-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Having the tag protocol in dsa_switch_driver for setup time and in
dsa_switch_tree for runtime is enough. Remove dsa_switch's one.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is the IPv6 counterpart to commit 8282f274 ("inet: frag: Always
orphan skbs inside ip_defrag()").

Prior to commit 029f7f3b ("netfilter: ipv6: nf_defrag: avoid/free
clone operations"), ipv6 fragments sent to nf_ct_frag6_gather() would be
cloned (implicitly orphaning) prior to queueing for reassembly. As such,
when the IPv6 message is eventually reassembled, the skb->sk for all
fragments would be NULL. After that commit was introduced, rather than
cloning, the original skbs were queued directly without orphaning. The
end result is that all frags except for the first and last may have a
socket attached.

This commit explicitly orphans such skbs during nf_ct_frag6_gather() to
prevent BUG_ON(skb->sk) during a later call to ip6_fragment().

kernel BUG at net/ipv6/ip6_output.c:631!
[...]
Call Trace:
 <IRQ>
 [<ffffffff810be8f7>] ? __lock_acquire+0x927/0x20a0
 [<ffffffffa042c7c0>] ? do_output.isra.28+0x1b0/0x1b0 [openvswitch]
 [<ffffffff810bb8a2>] ? __lock_is_held+0x52/0x70
 [<ffffffffa042c587>] ovs_fragment+0x1f7/0x280 [openvswitch]
 [<ffffffff810bdab5>] ? mark_held_locks+0x75/0xa0
 [<ffffffff817be416>] ? _raw_spin_unlock_irqrestore+0x36/0x50
 [<ffffffff81697ea0>] ? dst_discard_out+0x20/0x20
 [<ffffffff81697e80>] ? dst_ifdown+0x80/0x80
 [<ffffffffa042c703>] do_output.isra.28+0xf3/0x1b0 [openvswitch]
 [<ffffffffa042d279>] do_execute_actions+0x709/0x12c0 [openvswitch]
 [<ffffffffa04340a4>] ? ovs_flow_stats_update+0x74/0x1e0 [openvswitch]
 [<ffffffffa04340d1>] ? ovs_flow_stats_update+0xa1/0x1e0 [openvswitch]
 [<ffffffff817be387>] ? _raw_spin_unlock+0x27/0x40
 [<ffffffffa042de75>] ovs_execute_actions+0x45/0x120 [openvswitch]
 [<ffffffffa0432d65>] ovs_dp_process_packet+0x85/0x150 [openvswitch]
 [<ffffffff817be387>] ? _raw_spin_unlock+0x27/0x40
 [<ffffffffa042def4>] ovs_execute_actions+0xc4/0x120 [openvswitch]
 [<ffffffffa0432d65>] ovs_dp_process_packet+0x85/0x150 [openvswitch]
 [<ffffffffa04337f2>] ? key_extract+0x442/0xc10 [openvswitch]
 [<ffffffffa043b26d>] ovs_vport_receive+0x5d/0xb0 [openvswitch]
 [<ffffffff810be8f7>] ? __lock_acquire+0x927/0x20a0
 [<ffffffff810be8f7>] ? __lock_acquire+0x927/0x20a0
 [<ffffffff810be8f7>] ? __lock_acquire+0x927/0x20a0
 [<ffffffff817be416>] ? _raw_spin_unlock_irqrestore+0x36/0x50
 [<ffffffffa043c11d>] internal_dev_xmit+0x6d/0x150 [openvswitch]
 [<ffffffffa043c0b5>] ? internal_dev_xmit+0x5/0x150 [openvswitch]
 [<ffffffff8168fb5f>] dev_hard_start_xmit+0x2df/0x660
 [<ffffffff8168f5ea>] ? validate_xmit_skb.isra.105.part.106+0x1a/0x2b0
 [<ffffffff81690925>] __dev_queue_xmit+0x8f5/0x950
 [<ffffffff81690080>] ? __dev_queue_xmit+0x50/0x950
 [<ffffffff810bdab5>] ? mark_held_locks+0x75/0xa0
 [<ffffffff81690990>] dev_queue_xmit+0x10/0x20
 [<ffffffff8169a418>] neigh_resolve_output+0x178/0x220
 [<ffffffff81752759>] ? ip6_finish_output2+0x219/0x7b0
 [<ffffffff81752759>] ip6_finish_output2+0x219/0x7b0
 [<ffffffff817525a5>] ? ip6_finish_output2+0x65/0x7b0
 [<ffffffff816cde2b>] ? ip_idents_reserve+0x6b/0x80
 [<ffffffff8175488f>] ? ip6_fragment+0x93f/0xc50
 [<ffffffff81754af1>] ip6_fragment+0xba1/0xc50
 [<ffffffff81752540>] ? ip6_flush_pending_frames+0x40/0x40
 [<ffffffff81754c6b>] ip6_finish_output+0xcb/0x1d0
 [<ffffffff81754dcf>] ip6_output+0x5f/0x1a0
 [<ffffffff81754ba0>] ? ip6_fragment+0xc50/0xc50
 [<ffffffff81797fbd>] ip6_local_out+0x3d/0x80
 [<ffffffff817554df>] ip6_send_skb+0x2f/0xc0
 [<ffffffff817555bd>] ip6_push_pending_frames+0x4d/0x50
 [<ffffffff817796cc>] icmpv6_push_pending_frames+0xac/0xe0
 [<ffffffff8177a4be>] icmpv6_echo_reply+0x42e/0x500
 [<ffffffff8177acbf>] icmpv6_rcv+0x4cf/0x580
 [<ffffffff81755ac7>] ip6_input_finish+0x1a7/0x690
 [<ffffffff81755925>] ? ip6_input_finish+0x5/0x690
 [<ffffffff817567a0>] ip6_input+0x30/0xa0
 [<ffffffff81755920>] ? ip6_rcv_finish+0x1a0/0x1a0
 [<ffffffff817557ce>] ip6_rcv_finish+0x4e/0x1a0
 [<ffffffff8175640f>] ipv6_rcv+0x45f/0x7c0
 [<ffffffff81755fe6>] ? ipv6_rcv+0x36/0x7c0
 [<ffffffff81755780>] ? ip6_make_skb+0x1c0/0x1c0
 [<ffffffff8168b649>] __netif_receive_skb_core+0x229/0xb80
 [<ffffffff810bdab5>] ? mark_held_locks+0x75/0xa0
 [<ffffffff8168c07f>] ? process_backlog+0x6f/0x230
 [<ffffffff8168bfb6>] __netif_receive_skb+0x16/0x70
 [<ffffffff8168c088>] process_backlog+0x78/0x230
 [<ffffffff8168c0ed>] ? process_backlog+0xdd/0x230
 [<ffffffff8168db43>] net_rx_action+0x203/0x480
 [<ffffffff810bdab5>] ? mark_held_locks+0x75/0xa0
 [<ffffffff817c156e>] __do_softirq+0xde/0x49f
 [<ffffffff81752768>] ? ip6_finish_output2+0x228/0x7b0
 [<ffffffff817c070c>] do_softirq_own_stack+0x1c/0x30
 <EOI>
 [<ffffffff8106f88b>] do_softirq.part.18+0x3b/0x40
 [<ffffffff8106f946>] __local_bh_enable_ip+0xb6/0xc0
 [<ffffffff81752791>] ip6_finish_output2+0x251/0x7b0
 [<ffffffff81754af1>] ? ip6_fragment+0xba1/0xc50
 [<ffffffff816cde2b>] ? ip_idents_reserve+0x6b/0x80
 [<ffffffff8175488f>] ? ip6_fragment+0x93f/0xc50
 [<ffffffff81754af1>] ip6_fragment+0xba1/0xc50
 [<ffffffff81752540>] ? ip6_flush_pending_frames+0x40/0x40
 [<ffffffff81754c6b>] ip6_finish_output+0xcb/0x1d0
 [<ffffffff81754dcf>] ip6_output+0x5f/0x1a0
 [<ffffffff81754ba0>] ? ip6_fragment+0xc50/0xc50
 [<ffffffff81797fbd>] ip6_local_out+0x3d/0x80
 [<ffffffff817554df>] ip6_send_skb+0x2f/0xc0
 [<ffffffff817555bd>] ip6_push_pending_frames+0x4d/0x50
 [<ffffffff81778558>] rawv6_sendmsg+0xa28/0xe30
 [<ffffffff81719097>] ? inet_sendmsg+0xc7/0x1d0
 [<ffffffff817190d6>] inet_sendmsg+0x106/0x1d0
 [<ffffffff81718fd5>] ? inet_sendmsg+0x5/0x1d0
 [<ffffffff8166d078>] sock_sendmsg+0x38/0x50
 [<ffffffff8166d4d6>] SYSC_sendto+0xf6/0x170
 [<ffffffff8100201b>] ? trace_hardirqs_on_thunk+0x1b/0x1d
 [<ffffffff8166e38e>] SyS_sendto+0xe/0x10
 [<ffffffff817bebe5>] entry_SYSCALL_64_fastpath+0x18/0xa8
Code: 06 48 83 3f 00 75 26 48 8b 87 d8 00 00 00 2b 87 d0 00 00 00 48 39 d0 72 14 8b 87 e4 00 00 00 83 f8 01 75 09 48 83 7f 18 00 74 9a <0f> 0b 41 8b 86 cc 00 00 00 49 8#
RIP  [<ffffffff8175468a>] ip6_fragment+0x73a/0xc50
 RSP <ffff880072803120>

Fixes: 029f7f3b ("netfilter: ipv6: nf_defrag: avoid/free clone
operations")
Reported-by: NDaniele Di Proietto <diproiettod@vmware.com>
Signed-off-by: NJoe Stringer <joe@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds a new RTM_GETSTATS message to query link stats via netlink
from the kernel. RTM_NEWLINK also dumps stats today, but RTM_NEWLINK
returns a lot more than just stats and is expensive in some cases when
frequent polling for stats from userspace is a common operation.

RTM_GETSTATS is an attempt to provide a light weight netlink message
to explicity query only link stats from the kernel on an interface.
The idea is to also keep it extensible so that new kinds of stats can be
added to it in the future.

This patch adds the following attribute for NETDEV stats:
struct nla_policy ifla_stats_policy[IFLA_STATS_MAX + 1] = {
        [IFLA_STATS_LINK_64]  = { .len = sizeof(struct rtnl_link_stats64) },
};

Like any other rtnetlink message, RTM_GETSTATS can be used to get stats of
a single interface or all interfaces with NLM_F_DUMP.

Future possible new types of stat attributes:
link af stats:
    - IFLA_STATS_LINK_IPV6  (nested. for ipv6 stats)
    - IFLA_STATS_LINK_MPLS  (nested. for mpls/mdev stats)
extended stats:
    - IFLA_STATS_LINK_EXTENDED (nested. extended software netdev stats like bridge,
      vlan, vxlan etc)
    - IFLA_STATS_LINK_HW_EXTENDED (nested. extended hardware stats which are
      available via ethtool today)

This patch also declares a filter mask for all stat attributes.
User has to provide a mask of stats attributes to query. filter mask
can be specified in the new hdr 'struct if_stats_msg' for stats messages.
Other important field in the header is the ifindex.

This api can also include attributes for global stats (eg tcp) in the future.
When global stats are included in a stats msg, the ifindex in the header
must be zero. A single stats message cannot contain both global and
netdev specific stats. To easily distinguish them, netdev specific stat
attributes name are prefixed with IFLA_STATS_LINK_

Without any attributes in the filter_mask, no stats will be returned.

This patch has been tested with mofified iproute2 ifstat.
Suggested-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If skb_recv_datagram returns an skb, we should ignore the err
value returned. Otherwise, datagram receives will return EAGAIN
when they have to wait for a datagram.
Acked-by: NAdit Ranadive <aditr@vmware.com>
Signed-off-by: NJorgen Hansen <jhansen@vmware.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The dsa_slave_priv structure does not need a pointer to its net_device.
Kill it.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds a new helper for cls/act programs that can push events
to user space applications. For networking, this can be f.e. for sampling,
debugging, logging purposes or pushing of arbitrary wake-up events. The
idea is similar to a43eec30 ("bpf: introduce bpf_perf_event_output()
helper") and 39111695 ("samples: bpf: add bpf_perf_event_output example").

The eBPF program utilizes a perf event array map that user space populates
with fds from perf_event_open(), the eBPF program calls into the helper
f.e. as skb_event_output(skb, &my_map, BPF_F_CURRENT_CPU, raw, sizeof(raw))
so that the raw data is pushed into the fd f.e. at the map index of the
current CPU.

User space can poll/mmap/etc on this and has a data channel for receiving
events that can be post-processed. The nice thing is that since the eBPF
program and user space application making use of it are tightly coupled,
they can define their own arbitrary raw data format and what/when they
want to push.

While f.e. packet headers could be one part of the meta data that is being
pushed, this is not a substitute for things like packet sockets as whole
packet is not being pushed and push is only done in a single direction.
Intention is more of a generically usable, efficient event pipe to applications.
Workflow is that tc can pin the map and applications can attach themselves
e.g. after cls/act setup to one or multiple map slots, demuxing is done by
the eBPF program.

Adding this facility is with minimal effort, it reuses the helper
introduced in a43eec30 ("bpf: introduce bpf_perf_event_output() helper")
and we get its functionality for free by overloading its BPF_FUNC_ identifier
for cls/act programs, ctx is currently unused, but will be made use of in
future. Example will be added to iproute2's BPF example files.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Separated from previous patch for readability.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Struct ctl_table_header holds pointer to sysctl table which could be used
for freeing it after unregistration. IPv4 sysctls already use that.
Remove redundant NULL assignment: ndev allocated using kzalloc.

This also saves some bytes: sysctl table could be shorter than
DEVCONF_MAX+1 if some options are disable in config.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Suggested-by: NEric Dumazet <eric.dumazet@gmail.com>
Suggested-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since the nlattr header is 4 bytes in size, it can cause the netlink
attribute payload to not be 8-byte aligned.

This is particularly troublesome for IFLA_STATS64 which contains 64-bit
statistic values.

Solve this by creating a dummy IFLA_PAD attribute which has a payload
which is zero bytes in size.  When HAVE_EFFICIENT_UNALIGNED_ACCESS is
false, we insert an IFLA_PAD attribute into the netlink response when
necessary such that the IFLA_STATS64 payload will be properly aligned.

With help and suggestions from Eric Dumazet.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

read access doesn't need any lock here.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>