Add extack error message for invalid prefix length and invalid prefix.
Example of the latter is a route spec containing 172.16.100.1/24, where
the /24 mask means the lower 8-bits should be 0. Amazing how easy that
one is to overlook when an EINVAL is returned.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
fib_table_insert and fib_table_delete have the same checks on the prefix
and length. Refactor into a helper. Avoids duplicate extack messages in
the next patch.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Overlapping changes in drivers/net/phy/marvell.c, bug fix in 'net'
restricting a HW workaround alongside cleanups in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Andrey Konovalov reported crashes in ipv4_mtu()
I could reproduce the issue with KASAN kernels, between
10.246.7.151 and 10.246.7.152 :
1) 20 concurrent netperf -t TCP_RR -H 10.246.7.152 -l 1000 &
2) At the same time run following loop :
while :
do
ip ro add 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500
ip ro del 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500
done
Cong Wang attempted to add back rt->fi in commit
82486aa6f1 ("ipv4: restore rt->fi for reference counting")
but this proved to add some issues that were complex to solve.
Instead, I suggested to add a refcount to the metrics themselves,
being a standalone object (in particular, no reference to other objects)
I tried to make this patch as small as possible to ease its backport,
instead of being super clean. Note that we believe that only ipv4 dst
need to take care of the metric refcount. But if this is wrong,
this patch adds the basic infrastructure to extend this to other
families.
Many thanks to Julian Anastasov for reviewing this patch, and Cong Wang
for his efforts on this problem.
Fixes: 2860583fe8 ("ipv4: Kill rt->fi")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds support to return matched fib result when RTM_F_FIB_MATCH
flag is specified in RTM_GETROUTE request. This is useful for user-space
applications/controllers wanting to query a matching route.
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Prefix is needed for returning matching route spec on get route request.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert inet_rtm_getroute to use ip_route_input_rcu and
ip_route_output_key_hash_rcu passing the fib_result arg to both.
The rcu lock is held through the creation of the response, so the
rtable/dst does not need to be attached to the skb and is passed
to rt_fill_info directly.
In converting from ip_route_output_key to ip_route_output_key_hash_rcu
the xfrm_lookup_route in ip_route_output_flow is dropped since
flowi4_proto is not set for a route get request.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rt_fill_info has 1 caller with the event set to RTM_NEWROUTE. Given that
remove the arg and use RTM_NEWROUTE directly in rt_fill_info.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A later patch wants access to the fib result on an input route lookup
with the rcu lock held. Refactor ip_route_input_noref pushing the logic
between rcu_read_lock ... rcu_read_unlock into a new helper that takes
the fib_result as an input arg.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A later patch wants access to the fib result on an output route lookup
with the rcu lock held. Refactor __ip_route_output_key_hash, pushing
the logic between rcu_read_lock ... rcu_read_unlock into a new helper
with the fib_result as an input arg.
To keep the name length under control remove the leading underscores
from the name and add _rcu to the name of the new helper indicating it
is called with the rcu read lock held.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 7d472a59c0 ("arp: always override
existing neigh entries with gratuitous ARP") introduced a compiler
warning:
net/ipv4/arp.c:880:35: warning: 'addr_type' may be used uninitialized in
this function [-Wmaybe-uninitialized]
While the code logic seems to be correct and doesn't allow the variable
to be used uninitialized, and the warning is not consistently
reproducible, it's still worth fixing it for other people not to waste
time looking at the warning in case it pops up in the build environment.
Yes, compiler is probably at fault, but we will need to accommodate.
Fixes: 7d472a59c0 ("arp: always override existing neigh entries with gratuitous ARP")
Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fastopen API should be used to perform fastopen operations on the TCP
socket. It does not make sense to use fastopen API to perform disconnect
by calling it with AF_UNSPEC. The fastopen data path is also prone to
race conditions and bugs when using with AF_UNSPEC.
One issue reported and analyzed by Vegard Nossum is as follows:
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Thread A: Thread B:
------------------------------------------------------------------------
sendto()
- tcp_sendmsg()
- sk_stream_memory_free() = 0
- goto wait_for_sndbuf
- sk_stream_wait_memory()
- sk_wait_event() // sleep
| sendto(flags=MSG_FASTOPEN, dest_addr=AF_UNSPEC)
| - tcp_sendmsg()
| - tcp_sendmsg_fastopen()
| - __inet_stream_connect()
| - tcp_disconnect() //because of AF_UNSPEC
| - tcp_transmit_skb()// send RST
| - return 0; // no reconnect!
| - sk_stream_wait_connect()
| - sock_error()
| - xchg(&sk->sk_err, 0)
| - return -ECONNRESET
- ... // wake up, see sk->sk_err == 0
- skb_entail() on TCP_CLOSE socket
If the connection is reopened then we will send a brand new SYN packet
after thread A has already queued a buffer. At this point I think the
socket internal state (sequence numbers etc.) becomes messed up.
When the new connection is closed, the FIN-ACK is rejected because the
sequence number is outside the window. The other side tries to
retransmit,
but __tcp_retransmit_skb() calls tcp_trim_head() on an empty skb which
corrupts the skb data length and hits a BUG() in copy_and_csum_bits().
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Hence, this patch adds a check for AF_UNSPEC in the fastopen data path
and return EOPNOTSUPP to user if such case happens.
Fixes: cf60af03ca ("tcp: Fast Open client - sendmsg(MSG_FASTOPEN)")
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Paul Fiterau Brostean reported :
<quote>
Linux TCP stack we analyze exhibits behavior that seems odd to me.
The scenario is as follows (all packets have empty payloads, no window
scaling, rcv/snd window size should not be a factor):
TEST HARNESS (CLIENT) LINUX SERVER
1. - LISTEN (server listen,
then accepts)
2. - --> <SEQ=100><CTL=SYN> --> SYN-RECEIVED
3. - <-- <SEQ=300><ACK=101><CTL=SYN,ACK> <-- SYN-RECEIVED
4. - --> <SEQ=101><ACK=301><CTL=ACK> --> ESTABLISHED
5. - <-- <SEQ=301><ACK=101><CTL=FIN,ACK> <-- FIN WAIT-1 (server
opts to close the data connection calling "close" on the connection
socket)
6. - --> <SEQ=101><ACK=99999><CTL=FIN,ACK> --> CLOSING (client sends
FIN,ACK with not yet sent acknowledgement number)
7. - <-- <SEQ=302><ACK=102><CTL=ACK> <-- CLOSING (ACK is 102
instead of 101, why?)
... (silence from CLIENT)
8. - <-- <SEQ=301><ACK=102><CTL=FIN,ACK> <-- CLOSING
(retransmission, again ACK is 102)
Now, note that packet 6 while having the expected sequence number,
acknowledges something that wasn't sent by the server. So I would
expect
the packet to maybe prompt an ACK response from the server, and then be
ignored. Yet it is not ignored and actually leads to an increase of the
acknowledgement number in the server's retransmission of the FIN,ACK
packet. The explanation I found is that the FIN in packet 6 was
processed, despite the acknowledgement number being unacceptable.
Further experiments indeed show that the server processes this FIN,
transitioning to CLOSING, then on receiving an ACK for the FIN it had
send in packet 5, the server (or better said connection) transitions
from CLOSING to TIME_WAIT (as signaled by netstat).
</quote>
Indeed, tcp_rcv_state_process() calls tcp_ack() but
does not exploit the @acceptable status but for TCP_SYN_RECV
state.
What we want here is to send a challenge ACK, if not in TCP_SYN_RECV
state. TCP_FIN_WAIT1 state is not the only state we should fix.
Add a FLAG_NO_CHALLENGE_ACK so that tcp_rcv_state_process()
can choose to send a challenge ACK and discard the packet instead
of wrongly change socket state.
With help from Neal Cardwell.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Paul Fiterau Brostean <p.fiterau-brostean@science.ru.nl>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After the mentioned commit, some of our packetdrill tests became flaky.
TCP_SYNCNT socket option can limit the number of SYN retransmits.
retransmits_timed_out() has to compare times computations based on
local_clock() while timers are based on jiffies. With NTP adjustments
and roundings we can observe 999 ms delay for 1000 ms timers.
We end up sending one extra SYN packet.
Gimmick added in commit 6fa12c8503 ("Revert Backoff [v3]: Calculate
TCP's connection close threshold as a time value") makes no
real sense for TCP_SYN_SENT sockets where no RTO backoff can happen at
all.
Lets use a simpler logic for TCP_SYN_SENT sockets and remove @syn_set
parameter from retransmits_timed_out()
Fixes: 9a568de481 ("tcp: switch TCP TS option (RFC 7323) to 1ms clock")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Steffen Klassert says:
====================
pull request (net): ipsec 2017-05-23
1) Fix wrong header offset for esp4 udpencap packets.
2) Fix a stack access out of bounds when creating a bundle
with sub policies. From Sabrina Dubroca.
3) Fix slab-out-of-bounds in pfkey due to an incorrect
sadb_x_sec_len calculation.
4) We checked the wrong feature flags when taking down
an interface with IPsec offload enabled.
Fix from Ilan Tayari.
5) Copy the anti replay sequence numbers when doing a state
migration, otherwise we get out of sync with the sequence
numbers. Fix from Antony Antony.
Please pull or let me know if there are problems.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add messages for non-obvious errors (e.g, no need to add text for malloc
failures or ENODEV failures). This mostly covers the annoying EINVAL errors
Some message strings violate the 80-columns but searchable strings need to
trump that rule.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TCP_USER_TIMEOUT is still converted to jiffies value in
icsk_user_timeout
So we need to make a conversion for the cases HZ != 1000
Fixes: 9a568de481 ("tcp: switch TCP TS option (RFC 7323) to 1ms clock")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The build header functions are not used by any other code.
net/ipv6/fou6.c:36:5: warning: no previous prototype for ‘fou6_build_header’ [-Wmissing-prototypes]
net/ipv6/fou6.c:54:5: warning: no previous prototype for ‘gue6_build_header’ [-Wmissing-prototypes]
Need to do some code rearranging to satisfy different Kconfig possiblities.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The TCP New Vegas congestion control was exporting an internal
function tcpnv_get_info which is not used by any other in tree
kernel code. Make it static.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The prototype for inet_rcv_saddr_equal was not being included.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, when arp_accept is 1, we always override existing neigh
entries with incoming gratuitous ARP replies. Otherwise, we override
them only if new replies satisfy _locktime_ conditional (packets arrive
not earlier than _locktime_ seconds since the last update to the neigh
entry).
The idea behind locktime is to pick the very first (=> close) reply
received in a unicast burst when ARP proxies are used. This helps to
avoid ARP thrashing where Linux would switch back and forth from one
proxy to another.
This logic has nothing to do with gratuitous ARP replies that are
generally not aligned in time when multiple IP address carriers send
them into network.
This patch enforces overriding of existing neigh entries by all incoming
gratuitous ARP packets, irrespective of their time of arrival. This will
make the kernel honour all incoming gratuitous ARP packets.
Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The addr_type retrieval can be costly, so it's worth trying to avoid its
calculation as much as possible. This patch makes it calculated only
for gratuitous ARP packets. This is especially important since later we
may want to move is_garp calculation outside of arp_accept block, at
which point the costly operation will be executed for all setups.
The patch is the result of a discussion in net-dev:
http://marc.info/?l=linux-netdev&m=149506354216994
Suggested-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The code is quite involving already to earn a separate function for
itself. If anything, it helps arp_process readability.
Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
the is_garp code deals just with gratuitous ARP packets, not every
unsolicited packet.
This patch is a result of a discussion in netdev:
http://marc.info/?l=linux-netdev&m=149506354216994
Suggested-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When tcp_disconnect() is called, inet_csk_delack_init() sets
icsk->icsk_ack.rcv_mss to 0.
This could potentially cause tcp_recvmsg() => tcp_cleanup_rbuf() =>
__tcp_select_window() call path to have division by 0 issue.
So this patch initializes rcv_mss to TCP_MIN_MSS instead of 0.
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This bit was introduced with commit 5a21232983 ("net: Support for
csum_bad in skbuff") to reduce the stack workload when processing RX
packets carrying a wrong Internet Checksum. Up to now, only one driver and
GRO core are setting it.
Suggested-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit bafbb9c732 ("tcp: eliminate negative reordering
in tcp_clean_rtx_queue") fixes an issue for negative
reordering metrics.
To be resilient to such errors, warn and return
when a negative metric is passed to tcp_update_reordering().
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
skbs in (re)transmit queue no longer have a copy of jiffies
at the time of the transmit : skb->skb_mstamp is now in usec unit,
with no correlation to tcp_jiffies32.
We have to convert rto from jiffies to usec, compute a time difference
in usec, then convert the delta to HZ units.
Fixes: 9a568de481 ("tcp: switch TCP TS option (RFC 7323) to 1ms clock")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This function has to return NULL on a error case, because there is a
separate error variable.
The offset has to be changed only if skb is returned
v2: fix udp code to not use an extra variable
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: David S. Miller <davem@davemloft.net>
Fixes: 65101aeca5 ("net/sock: factor out dequeue/peek with offset cod")
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since the udp memory accounting refactor, we don't need any more
to export the *udp*_queue_rcv_skb(). Make them static and fix
a couple of sparse warnings:
net/ipv4/udp.c:1615:5: warning: symbol 'udp_queue_rcv_skb' was not
declared. Should it be static?
net/ipv6/udp.c:572:5: warning: symbol 'udpv6_queue_rcv_skb' was not
declared. Should it be static?
Fixes: 850cbaddb5 ("udp: use it's own memory accounting schema")
Fixes: c915fe13cb ("udplite: fix NULL pointer dereference")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Function udp_skb_dtor_locked does not need to be in global scope
so make it static to fix sparse warning:
net/ipv4/udp.c: warning: symbol 'udp_skb_dtor_locked' was not
declared. Should it be static?
Fixes: 6dfb4367cd ("udp: keep the sk_receive_queue held when splicing")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TCP Timestamps option is defined in RFC 7323
Traditionally on linux, it has been tied to the internal
'jiffies' variable, because it had been a cheap and good enough
generator.
For TCP flows on the Internet, 1 ms resolution would be much better
than 4ms or 10ms (HZ=250 or HZ=100 respectively)
For TCP flows in the DC, Google has used usec resolution for more
than two years with great success [1]
Receive size autotuning (DRS) is indeed more precise and converges
faster to optimal window size.
This patch converts tp->tcp_mstamp to a plain u64 value storing
a 1 usec TCP clock.
This choice will allow us to upstream the 1 usec TS option as
discussed in IETF 97.
[1] https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-tcp-options-for-low-latency-00.pdf
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After this patch, all uses of tcp_time_stamp will require
a change when we introduce 1 ms and/or 1 us TCP TS option.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp_time_stamp will become slightly more expensive soon,
cache its value.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This CC does not need 1 ms tcp_time_stamp and can use
the jiffy based 'timestamp'.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This place wants to use tcp_jiffies32, this is good enough.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp_time_stamp will no longer be tied to jiffies.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use tcp_jiffies32 instead of tcp_time_stamp, since
tcp_time_stamp will soon be only used for TCP TS option.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use tcp_jiffies32 instead of tcp_time_stamp, since
tcp_time_stamp will soon be only used for TCP TS option.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use tcp_jiffies32 instead of tcp_time_stamp, since
tcp_time_stamp will soon be only used for TCP TS option.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use tcp_jiffies32 instead of tcp_time_stamp, since
tcp_time_stamp will soon be only used for TCP TS option.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use tcp_jiffies32 instead of tcp_time_stamp to feed
tp->snd_cwnd_stamp.
tcp_time_stamp will soon be a litle bit more expensive
than simply reading 'jiffies'.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use tcp_jiffies32 instead of tcp_time_stamp to feed
tp->lsndtime.
tcp_time_stamp will soon be a litle bit more expensive
than simply reading 'jiffies'.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Idea is to later convert tp->tcp_mstamp to a full u64 counter
using usec resolution, so that we can later have fine
grained TCP TS clock (RFC 7323), regardless of HZ value.
We try to refresh tp->tcp_mstamp only when necessary.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When arp_accept is 1, gratuitous ARPs are supposed to override matching
entries irrespective of whether they arrive during locktime. This was
implemented in commit 56022a8fdd ("ipv4: arp: update neighbour address
when a gratuitous arp is received and arp_accept is set")
There is a glitch in the patch though. RFC 2002, section 4.6, "ARP,
Proxy ARP, and Gratuitous ARP", defines gratuitous ARPs so that they can
be either of Request or Reply type. Those Reply gratuitous ARPs can be
triggered with standard tooling, for example, arping -A option does just
that.
This patch fixes the glitch, making both Request and Reply flavours of
gratuitous ARPs to behave identically.
As per RFC, if gratuitous ARPs are of Reply type, their Target Hardware
Address field should also be set to the link-layer address to which this
cache entry should be updated. The field is present in ARP over Ethernet
but not in IEEE 1394. In this patch, I don't consider any broadcasted
ARP replies as gratuitous if the field is not present, to conform the
standard. It's not clear whether there is such a thing for IEEE 1394 as
a gratuitous ARP reply; until it's cleared up, we will ignore such
broadcasts. Note that they will still update existing ARP cache entries,
assuming they arrive out of locktime time interval.
Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
BBR congestion control depends on pacing, and pacing is
currently handled by sch_fq packet scheduler for performance reasons,
and also because implemening pacing with FQ was convenient to truly
avoid bursts.
However there are many cases where this packet scheduler constraint
is not practical.
- Many linux hosts are not focusing on handling thousands of TCP
flows in the most efficient way.
- Some routers use fq_codel or other AQM, but still would like
to use BBR for the few TCP flows they initiate/terminate.
This patch implements an automatic fallback to internal pacing.
Pacing is requested either by BBR or use of SO_MAX_PACING_RATE option.
If sch_fq happens to be in the egress path, pacing is delegated to
the qdisc, otherwise pacing is done by TCP itself.
One advantage of pacing from TCP stack is to get more precise rtt
estimations, and less work done from TX completion, since TCP Small
queue limits are not generally hit. Setups with single TX queue but
many cpus might even benefit from this.
Note that unlike sch_fq, we do not take into account header sizes.
Taking care of these headers would add additional complexity for
no practical differences in behavior.
Some performance numbers using 800 TCP_STREAM flows rate limited to
~48 Mbit per second on 40Gbit NIC.
If MQ+pfifo_fast is used on the NIC :
$ sar -n DEV 1 5 | grep eth
14:48:44 eth0 725743.00 2932134.00 46776.76 4335184.68 0.00 0.00 1.00
14:48:45 eth0 725349.00 2932112.00 46751.86 4335158.90 0.00 0.00 0.00
14:48:46 eth0 725101.00 2931153.00 46735.07 4333748.63 0.00 0.00 0.00
14:48:47 eth0 725099.00 2931161.00 46735.11 4333760.44 0.00 0.00 1.00
14:48:48 eth0 725160.00 2931731.00 46738.88 4334606.07 0.00 0.00 0.00
Average: eth0 725290.40 2931658.20 46747.54 4334491.74 0.00 0.00 0.40
$ vmstat 1 5
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
r b swpd free buff cache si so bi bo in cs us sy id wa st
4 0 0 259825920 45644 2708324 0 0 21 2 247 98 0 0 100 0 0
4 0 0 259823744 45644 2708356 0 0 0 0 2400825 159843 0 19 81 0 0
0 0 0 259824208 45644 2708072 0 0 0 0 2407351 159929 0 19 81 0 0
1 0 0 259824592 45644 2708128 0 0 0 0 2405183 160386 0 19 80 0 0
1 0 0 259824272 45644 2707868 0 0 0 32 2396361 158037 0 19 81 0 0
Now use MQ+FQ :
lpaa23:~# echo fq >/proc/sys/net/core/default_qdisc
lpaa23:~# tc qdisc replace dev eth0 root mq
$ sar -n DEV 1 5 | grep eth
14:49:57 eth0 678614.00 2727930.00 43739.13 4033279.14 0.00 0.00 0.00
14:49:58 eth0 677620.00 2723971.00 43674.69 4027429.62 0.00 0.00 1.00
14:49:59 eth0 676396.00 2719050.00 43596.83 4020125.02 0.00 0.00 0.00
14:50:00 eth0 675197.00 2714173.00 43518.62 4012938.90 0.00 0.00 1.00
14:50:01 eth0 676388.00 2719063.00 43595.47 4020171.64 0.00 0.00 0.00
Average: eth0 676843.00 2720837.40 43624.95 4022788.86 0.00 0.00 0.40
$ vmstat 1 5
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
r b swpd free buff cache si so bi bo in cs us sy id wa st
2 0 0 259832240 46008 2710912 0 0 21 2 223 192 0 1 99 0 0
1 0 0 259832896 46008 2710744 0 0 0 0 1702206 198078 0 17 82 0 0
0 0 0 259830272 46008 2710596 0 0 0 0 1696340 197756 1 17 83 0 0
4 0 0 259829168 46024 2710584 0 0 16 0 1688472 197158 1 17 82 0 0
3 0 0 259830224 46024 2710408 0 0 0 0 1692450 197212 0 18 82 0 0
As expected, number of interrupts per second is very different.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Van Jacobson <vanj@google.com>
Cc: Jerry Chu <hkchu@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>