After reading the function rt6_check_neigh(), we can
know that the RT6_NUD_FAIL_SOFT can be returned only
when the IS_ENABLE(CONFIG_IPV6_ROUTER_PREF) is false.
so in function find_match(), there is no need to execute
the statement !IS_ENABLED(CONFIG_IPV6_ROUTER_PREF).
Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The message dispatching part of tipc_recv_msg() is wrapped layers of
while/if/if/switch, causing out-of-control indentation and does not
look very good. We reduce two indentation levels by separating the
message dispatching from the blocks that checks link state and
sequence numbers, allowing longer function and arg names to be
consistently indented without wrapping. Additionally we also rename
"cont" label to "discard" and add one new label called "unlock_discard"
to make code clearer. In all, these are cosmetic changes that do not
alter the operation of TIPC in any way.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Cc: David Laight <david.laight@aculab.com>
Cc: Andreas Bofjäll <andreas.bofjall@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fast Open currently has a fall back feature to address SYN-data being
dropped but it requires the middle-box to pass on regular SYN retry
after SYN-data. This is implemented in commit aab487435 ("net-tcp:
Fast Open client - detecting SYN-data drops")
However some NAT boxes will drop all subsequent packets after first
SYN-data and blackholes the entire connections. An example is in
commit 356d7d8 "netfilter: nf_conntrack: fix tcp_in_window for Fast
Open".
The sender should note such incidents and fall back to use the regular
TCP handshake on subsequent attempts temporarily as well: after the
second SYN timeouts the original Fast Open SYN is most likely lost.
When such an event recurs Fast Open is disabled based on the number of
recurrences exponentially.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This work contains a lightweight BPF-based traffic classifier that can
serve as a flexible alternative to ematch-based tree classification, i.e.
now that BPF filter engine can also be JITed in the kernel. Naturally, tc
actions and policies are supported as well with cls_bpf. Multiple BPF
programs/filter can be attached for a class, or they can just as well be
written within a single BPF program, that's really up to the user how he
wishes to run/optimize the code, e.g. also for inversion of verdicts etc.
The notion of a BPF program's return/exit codes is being kept as follows:
0: No match
-1: Select classid given in "tc filter ..." command
else: flowid, overwrite the default one
As a minimal usage example with iproute2, we use a 3 band prio root qdisc
on a router with sfq each as leave, and assign ssh and icmp bpf-based
filters to band 1, http traffic to band 2 and the rest to band 3. For the
first two bands we load the bytecode from a file, in the 2nd we load it
inline as an example:
echo 1 > /proc/sys/net/core/bpf_jit_enable
tc qdisc del dev em1 root
tc qdisc add dev em1 root handle 1: prio bands 3 priomap 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
tc qdisc add dev em1 parent 1:1 sfq perturb 16
tc qdisc add dev em1 parent 1:2 sfq perturb 16
tc qdisc add dev em1 parent 1:3 sfq perturb 16
tc filter add dev em1 parent 1: bpf run bytecode-file /etc/tc/ssh.bpf flowid 1:1
tc filter add dev em1 parent 1: bpf run bytecode-file /etc/tc/icmp.bpf flowid 1:1
tc filter add dev em1 parent 1: bpf run bytecode-file /etc/tc/http.bpf flowid 1:2
tc filter add dev em1 parent 1: bpf run bytecode "`bpfc -f tc -i misc.ops`" flowid 1:3
BPF programs can be easily created and passed to tc, either as inline
'bytecode' or 'bytecode-file'. There are a couple of front-ends that can
compile opcodes, for example:
1) People familiar with tcpdump-like filters:
tcpdump -iem1 -ddd port 22 | tr '\n' ',' > /etc/tc/ssh.bpf
2) People that want to low-level program their filters or use BPF
extensions that lack support by libpcap's compiler:
bpfc -f tc -i ssh.ops > /etc/tc/ssh.bpf
ssh.ops example code:
ldh [12]
jne #0x800, drop
ldb [23]
jneq #6, drop
ldh [20]
jset #0x1fff, drop
ldxb 4 * ([14] & 0xf)
ldh [%x + 14]
jeq #0x16, pass
ldh [%x + 16]
jne #0x16, drop
pass: ret #-1
drop: ret #0
It was chosen to load bytecode into tc, since the reverse operation,
tc filter list dev em1, is then able to show the exact commands again.
Possible follow-up work could also include a small expression compiler
for iproute2. Tested with the help of bmon. This idea came up during
the Netfilter Workshop 2013 in Copenhagen. Also thanks to feedback from
Eric Dumazet!
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
UFO as well as UDP_CORK do not respect IP_PMTUDISC_DO and
IP_PMTUDISC_PROBE well enough.
UFO enabled packet delivery just appends all frags to the cork and hands
it over to the network card. So we just deliver non-DF udp fragments
(DF-flag may get overwritten by hardware or virtual UFO enabled
interface).
UDP_CORK does enqueue the data until the cork is disengaged. At this
point it sets the correct IP_DF and local_df flags and hands it over to
ip_fragment which in this case will generate an icmp error which gets
appended to the error socket queue. This is not reflected in the syscall
error (of course, if UFO is enabled this also won't happen).
Improve this by checking the pmtudisc flags before appending data to the
socket and if we still can fit all data in one packet when IP_PMTUDISC_DO
or IP_PMTUDISC_PROBE is set, only then proceed.
We use (mtu-fragheaderlen) to check for the maximum length because we
ensure not to generate a fragment and non-fragmented data does not need
to have its length aligned on 64 bit boundaries. Also the passed in
ip_options are already aligned correctly.
Maybe, we can relax some other checks around ip_fragment. This needs
more research.
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The code for privacy extentions is very mature, and making it
configurable only gives marginal memory/code savings in exchange
for obfuscation and hard to read code via CPP ifdef'ery.
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes the assignment of skb->dev. We don't need it here because
we use the netdev_alloc_skb_ip_align function which already sets the
skb->dev.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Reviewed-by: Werner Almesberger <werner@almesberger.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch uses the netdev_alloc_skb instead dev_alloc_skb function and
drops the seperate assignment to skb->dev.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Reviewed-by: Werner Almesberger <werner@almesberger.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Two if statements do the same work, we can merge them to
one. And fix some typos. There is just code simplification,
no functional changes.
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
kmem_cache_zalloc had set the allocated memory to zero. I think no need
to initialize with 0. And move the comments to the function begin.
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Alexei reported a performance regression on vxlan, caused
by commit 3347c96029 "ipv4: gso: make inet_gso_segment() stackable"
GSO vxlan packets were not properly segmented, adding IP fragments
while they were not expected.
Rename 'bool tunnel' to 'bool encap', and add a new boolean
to express the fact that UDP should be fragmented.
This fragmentation is triggered by skb->encapsulation being set.
Remove a "skb->encapsulation = 1" added in above commit,
as its not needed, as frags inherit skb->frag from original
GSO skb.
Reported-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We also can defer the initialization of hashrnd in flow_dissector
to its first use. Since net_get_random_once is irq safe now we don't
have to audit the call paths if one of this functions get called by an
interrupt handler.
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
I initial build non irq safe version of net_get_random_once because I
would liked to have the freedom to defer even the extraction process of
get_random_bytes until the nonblocking pool is fully seeded.
I don't think this is a good idea anymore and thus this patch makes
net_get_random_once irq safe. Now someone using net_get_random_once does
not need to care from where it is called.
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The transition from markov state "3 => lost packets within a burst
period" to "1 => successfully transmitted packets within a gap period"
has no *additional* loss event. The loss already happen for transition
from 1 -> 3, this additional loss will make things go wild.
E.g. transition probabilities:
p13: 10%
p31: 100%
Expected:
Ploss = p13 / (p13 + p31)
Ploss = ~9.09%
... but it isn't. Even worse: we get a double loss - each time.
So simple don't return true to indicate loss, rather break and return
false.
Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Stefano Salsano <stefano.salsano@uniroma2.it>
Cc: Fabio Ludovici <fabio.ludovici@yahoo.it>
Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Antonio Quartulli says:
====================
this is another set of changes intended for net-next/linux-3.13.
(probably our last pull request for this cycle)
Patches 1 and 2 reshape two of our main data structures in a way that they can
easily be extended in the future to accommodate new routing protocols.
Patches from 3 to 9 improve our routing protocol API and its users so that all
the protocol-related code is not mixed up with the other components anymore.
Patch 10 limits the local Translation Table maximum size to a value such that it
can be fully transfered over the air if needed. This value depends on
fragmentation being enabled or not and on the mtu values.
Patch 11 makes batman-adv send a uevent in case of soft-interface destruction
while a "bat-Gateway" was configured (this informs userspace about the GW not
being available anymore).
Patches 13 and 14 enable the TT component to detect non-mesh client flag
changes at runtime (till now those flags where set upon client detection and
were not changed anymore).
Patch 16 is a generalisation of our user-to-kernel space communication (and
viceversa) used to exchange ICMP packets to send/received to/from the mesh
network. Now it can easily accommodate new ICMP packet types without breaking
the existing userspace API anymore.
Remaining patches are minor changes and cleanups.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Duan Jiong
Chen Weilong
Ying Xue
Yuchung Cheng
Daniel Borkmann
Zhi Yong Wu
Hannes Frederic Sowa
David S. Miller
Alexander Aring
wangweidong
Eric Dumazet
Alexei Starovoitov
Nikolay Aleksandrov
Hagen Paul Pfeifer