The "else" block is on several lines and use bracket.
Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch allows to set ECN on a per-route basis in case the sysctl
tcp_ecn is not set to 1. In other words, when ECN is set for specific
routes, it provides a tcp_ecn=1 behaviour for that route while the rest
of the stack acts according to the global settings.
One can use 'ip route change dev $dev $net features ecn' to toggle this.
Having a more fine-grained per-route setting can be beneficial for various
reasons, for example, 1) within data centers, or 2) local ISPs may deploy
ECN support for their own video/streaming services [1], etc.
There was a recent measurement study/paper [2] which scanned the Alexa's
publicly available top million websites list from a vantage point in US,
Europe and Asia:
Half of the Alexa list will now happily use ECN (tcp_ecn=2, most likely
blamed to commit 255cac91c3 ("tcp: extend ECN sysctl to allow server-side
only ECN") ;)); the break in connectivity on-path was found is about
1 in 10,000 cases. Timeouts rather than receiving back RSTs were much
more common in the negotiation phase (and mostly seen in the Alexa
middle band, ranks around 50k-150k): from 12-thousand hosts on which
there _may_ be ECN-linked connection failures, only 79 failed with RST
when _not_ failing with RST when ECN is not requested.
It's unclear though, how much equipment in the wild actually marks CE
when buffers start to fill up.
We thought about a fallback to non-ECN for retransmitted SYNs as another
global option (which could perhaps one day be made default), but as Eric
points out, there's much more work needed to detect broken middleboxes.
Two examples Eric mentioned are buggy firewalls that accept only a single
SYN per flow, and middleboxes that successfully let an ECN flow establish,
but later mark CE for all packets (so cwnd converges to 1).
[1] http://www.ietf.org/proceedings/89/slides/slides-89-tsvarea-1.pdf, p.15
[2] http://ecn.ethz.ch/
Joint work with Daniel Borkmann.
Reference: http://thread.gmane.org/gmane.linux.network/335797
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The function cookie_check_timestamp(), both called from IPv4/6 context,
is being used to decode the echoed timestamp from the SYN/ACK into TCP
options used for follow-up communication with the peer.
We can remove ECN handling from that function, split it into a separate
one, and simply rename the original function into cookie_decode_options().
cookie_decode_options() just fills in tcp_option struct based on the
echoed timestamp received from the peer. Anything that fails in this
function will actually discard the request socket.
While this is the natural place for decoding options such as ECN which
commit 172d69e63c ("syncookies: add support for ECN") added, we argue
that in particular for ECN handling, it can be checked at a later point
in time as the request sock would actually not need to be dropped from
this, but just ECN support turned off.
Therefore, we split this functionality into cookie_ecn_ok(), which tells
us if the timestamp indicates ECN support AND the tcp_ecn sysctl is enabled.
This prepares for per-route ECN support: just looking at the tcp_ecn sysctl
won't be enough anymore at that point; if the timestamp indicates ECN
and sysctl tcp_ecn == 0, we will also need to check the ECN dst metric.
This would mean adding a route lookup to cookie_check_timestamp(), which
we definitely want to avoid. As we already do a route lookup at a later
point in cookie_{v4,v6}_check(), we can simply make use of that as well
for the new cookie_ecn_ok() function w/o any additional cost.
Joint work with Daniel Borkmann.
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Was a bit more difficult to read than needed due to magic shifts;
add defines and document the used encoding scheme.
Joint work with Daniel Borkmann.
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
else is unnecessary after return 0 in __udp4_lib_rcv()
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
remove __inline__ / inline and let compiler decide what to do
with static functions
Inspired-by: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
Yaogong replaces TCP out of order receive queue by an RB tree.
As netem already does a private skb->{next/prev/tstamp} union
with a 'struct rb_node', lets do this in a cleaner way.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yaogong Wang <wygivan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net_rx_action() can mask irqs a single time to transfert sd->poll_list
into a private list, for a very short duration.
Then, napi_complete() can avoid masking irqs again,
and net_rx_action() only needs to mask irq again in slow path.
This patch removes 2 couples of irq mask/unmask per typical NAPI run,
more if multiple napi were triggered.
Note this also allows to give control back to caller (do_softirq())
more often, so that other softirq handlers can be called a bit earlier,
or ksoftirqd can be wakeup earlier under pressure.
This was developed while testing an alternative to RX interrupt
mitigation to reduce latencies while keeping or improving GRO
aggregation on fast NIC.
Idea is to test napi->gro_list at the end of a napi->poll() and
reschedule one NAPI poll, but after servicing a full round of
softirqs (timers, TX, rcu, ...). This will be allowed only if softirq
is currently serviced by idle task or ksoftirqd, and resched not needed.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a driver supports reading EEPROM but no EEPROM is installed in the system,
the driver's get_eeprom_len function returns 0. ethtool will subsequently
try to read that zero-length EEPROM anyway. If the driver does not support
EEPROM access at all, this operation will return -EOPNOTSUPP. If the driver
does support EEPROM access but no EEPROM is installed, the operation will
return -EINVAL. Return -EOPNOTSUPP in both cases for consistency.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Kconfig already allows mpls to be built as module. Following patch
fixes Makefile to do same.
CC: Simon Horman <simon.horman@netronome.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
mpls gso handler needs to pull skb after segmenting skb.
CC: Simon Horman <simon.horman@netronome.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
netfilter/ipvs fixes for net
The following patchset contains fixes for netfilter/ipvs. This round of
fixes is larger than usual at this stage, specifically because of the
nf_tables bridge reject fixes that I would like to see in 3.18. The
patches are:
1) Fix a null-pointer dereference that may occur when logging
errors. This problem was introduced by 4a4739d56b ("ipvs: Pull
out crosses_local_route_boundary logic") in v3.17-rc5.
2) Update hook mask in nft_reject_bridge so we can also filter out
packets from there. This fixes 36d2af5 ("netfilter: nf_tables: allow
to filter from prerouting and postrouting"), which needs this chunk
to work.
3) Two patches to refactor common code to forge the IPv4 and IPv6
reject packets from the bridge. These are required by the nf_tables
reject bridge fix.
4) Fix nft_reject_bridge by avoiding the use of the IP stack to reject
packets from the bridge. The idea is to forge the reject packets and
inject them to the original port via br_deliver() which is now
exported for that purpose.
5) Restrict nft_reject_bridge to bridge prerouting and input hooks.
the original skbuff may cloned after prerouting when the bridge stack
needs to flood it to several bridge ports, it is too late to reject
the traffic.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Restrict the reject expression to the prerouting and input bridge
hooks. If we allow this to be used from forward or any other later
bridge hook, if the frame is flooded to several ports, we'll end up
sending several reject packets, one per cloned packet.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If the packet is received via the bridge stack, this cannot reject
packets from the IP stack.
This adds functions to build the reject packet and send it from the
bridge stack. Comments and assumptions on this patch:
1) Validate the IPv4 and IPv6 headers before further processing,
given that the packet comes from the bridge stack, we cannot assume
they are clean. Truncated packets are dropped, we follow similar
approach in the existing iptables match/target extensions that need
to inspect layer 4 headers that is not available. This also includes
packets that are directed to multicast and broadcast ethernet
addresses.
2) br_deliver() is exported to inject the reject packet via
bridge localout -> postrouting. So the approach is similar to what
we already do in the iptables reject target. The reject packet is
sent to the bridge port from which we have received the original
packet.
3) The reject packet is forged based on the original packet. The TTL
is set based on sysctl_ip_default_ttl for IPv4 and per-net
ipv6.devconf_all hoplimit for IPv6.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
That can be reused by the reject bridge expression to build the reject
packet. The new functions are:
* nf_reject_ip6_tcphdr_get(): to sanitize and to obtain the TCP header.
* nf_reject_ip6hdr_put(): to build the IPv6 header.
* nf_reject_ip6_tcphdr_put(): to build the TCP header.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
That can be reused by the reject bridge expression to build the reject
packet. The new functions are:
* nf_reject_ip_tcphdr_get(): to sanitize and to obtain the TCP header.
* nf_reject_iphdr_put(): to build the IPv4 header.
* nf_reject_ip_tcphdr_put(): to build the TCP header.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
UFO is now disabled on all drivers that work with virtio net headers,
but userland may try to send UFO/IPv6 packets anyway. Instead of
sending with ID=0, we should select identifiers on their behalf (as we
used to).
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Fixes: 916e4cf46d ("ipv6: reuse ip6_frag_id from ip6_ufo_append_data")
Signed-off-by: David S. Miller <davem@davemloft.net>
Some drivers are unable to perform TX completions in a bound time.
They instead call skb_orphan()
Problem is skb_fclone_busy() has to detect this case, otherwise
we block TCP retransmits and can freeze unlucky tcp sessions on
mostly idle hosts.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 1f3279ae0c ("tcp: avoid retransmits of TCP packets hanging in host queues")
Signed-off-by: David S. Miller <davem@davemloft.net>
Challenge ACK is described in RFC 5961, fix typo.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, skb_inner_network_header is used but this does not account
for Ethernet header for ETH_P_TEB. Use skb_inner_mac_header which
handles TEB and also should work with IP encapsulation in which case
inner mac and inner network headers are the same.
Tested: Ran TCP_STREAM over GRE, worked as expected.
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes checkpatch warning:
"WARNING: Prefer seq_puts to seq_printf"
Signed-off-by: Michele Baldessari <michele@acksyn.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It is often quite helpful to be able to know the state of a transport
outside of the application itself (for troubleshooting purposes or for
monitoring purposes). Add it under /proc/net/sctp/remaddr.
Signed-off-by: Michele Baldessari <michele@acksyn.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If we cache them, the kernel will reuse them, independently of
whether forwarding is enabled or not. Which means that if forwarding is
disabled on the input interface where the first routing request comes
from, then that unreachable result will be cached and reused for
other interfaces, even if forwarding is enabled on them. The opposite
is also true.
This can be verified with two interfaces A and B and an output interface
C, where B has forwarding enabled, but not A and trying
ip route get $dst iif A from $src && ip route get $dst iif B from $src
Signed-off-by: Nicolas Cavallari <nicolas.cavallari@green-communications.fr>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
Only count packets that failed cookie-authentication.
We can get SYNCOOKIESFAILED > 0 while we never even sent a single cookie.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The fallback device is in ipv6 mode by default.
The mode can not be changed in runtime, so there
is no way to decapsulate ip4in6 packets coming from
various sources without creating the specific tunnel
ifaces for each peer.
This allows to update the fallback tunnel device, but only
the mode could be changed. Usual command should work for the
fallback device: `ip -6 tun change ip6tnl0 mode any`
The fallback device can not be hidden from the packet receiver
as a regular tunnel, but there is no need for synchronization
as long as we do single assignment.
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexey Andriyanov <alan@al-an.info>
Signed-off-by: David S. Miller <davem@davemloft.net>
Do assignment before if condition and test !skb like in rawv6_recvmsg()
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
remove __inline__ / inline and let compiler decide what to do
with static functions
Inspired-by: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
Apply commit e0f36310f7
("ipx: remove unnecessary casting on ntohl")
to all seq_printf/08lX
Inspired-by: "David S. Miller" <davem@davemloft.net>
Inspired-by: Joe Perches <joe@perches.com>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for reading switch registers with 'ethtool -d'.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
On some chips it is possible to access the switch eeprom.
Add infrastructure support for it.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some switches provide chip temperature data.
Add support for reporting it through the hwmon subsystem.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Setting skb->protocol to a private protocol type may result in warning
messages such as
e1000e 0000:00:19.0 em1: checksum_partial proto=dada!
This happens if the L3 protocol is IP or IPv6 and skb->ip_summed is set
to CHECKSUM_PARTIAL. Looking through the code, it appears that changing
skb->protocol for transmitted packets is not necessary and may actually
be harmful. For example, it prevents purposely unmodified (from a DSA
perspective) network drivers from properly setting up their transmit
checksum offload pointers since they inspect skb->protocol to set up the
IPv4 header or IPv6 header pointers. So don't unnecessarily change the
protocol field.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
In neigh_parms_release() we loop over all entries to find the entry given in
argument and being able to remove it from the list. By using a double linked
list, we can avoid this loop.
Here are some numbers with 30 000 dummy interfaces configured:
Before the patch:
$ time rmmod dummy
real 2m0.118s
user 0m0.000s
sys 1m50.048s
After the patch:
$ time rmmod dummy
real 1m9.970s
user 0m0.000s
sys 0m47.976s
Suggested-by: Thierry Herbelot <thierry.herbelot@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
napi_schedule() can be called from any context and has to mask hard
irqs.
Add a variant that can only be called from hard interrupts handlers
or when irqs are already masked.
Many NIC drivers can use it from their hard IRQ handler instead of
generic variant.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The WARN_ON in inet_evict_bucket can be triggered by a valid case:
inet_frag_kill and inet_evict_bucket can be running in parallel on the
same queue which means that there has been at least one more ref added
by a previous inet_frag_find call, but inet_frag_kill can delete the
timer before inet_evict_bucket which will cause the WARN_ON() there to
trigger since we'll have refcnt!=1. Now, this case is valid because the
queue is being "killed" for some reason (removed from the chain list and
its timer deleted) so it will get destroyed in the end by one of the
inet_frag_put() calls which reaches 0 i.e. refcnt is still valid.
CC: Florian Westphal <fw@strlen.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McLean <chutzpah@gentoo.org>
Fixes: b13d3cbfb8 ("inet: frag: move eviction of queues to work queue")
Reported-by: Patrick McLean <chutzpah@gentoo.org>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the evictor is running it adds some chosen frags to a local list to
be evicted once the chain lock has been released but at the same time
the *frag_queue can be running for some of the same queues and it
may call inet_frag_kill which will wait on the chain lock and
will then delete the queue from the wrong list since it was added in the
eviction one. The fix is simple - check if the queue has the evict flag
set under the chain lock before deleting it, this is safe because the
evict flag is set only under that lock and having the flag set also means
that the queue has been detached from the chain list, so no need to delete
it again.
An important note to make is that we're safe w.r.t refcnt because
inet_frag_kill and inet_evict_bucket will sync on the del_timer operation
where only one of the two can succeed (or if the timer is executing -
none of them), the cases are:
1. inet_frag_kill succeeds in del_timer
- then the timer ref is removed, but inet_evict_bucket will not add
this queue to its expire list but will restart eviction in that chain
2. inet_evict_bucket succeeds in del_timer
- then the timer ref is kept until the evictor "expires" the queue, but
inet_frag_kill will remove the initial ref and will set
INET_FRAG_COMPLETE which will make the frag_expire fn just to remove
its ref.
In the end all of the queue users will do an inet_frag_put and the one
that reaches 0 will free it. The refcount balance should be okay.
CC: Florian Westphal <fw@strlen.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McLean <chutzpah@gentoo.org>
Fixes: b13d3cbfb8 ("inet: frag: move eviction of queues to work queue")
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Reported-by: Patrick McLean <chutzpah@gentoo.org>
Tested-by: Patrick McLean <chutzpah@gentoo.org>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fabian Frederick