In many deployments, we want the option to not learn a neighbor from
garp if the src ip is not in the same subnet as an address configured
on the interface that received the garp message. net.ipv4.arp_accept
sysctl is currently used to control creation of a neigh from a
received garp packet. This patch adds a new option '2' to
net.ipv4.arp_accept which extends option '1' by including the subnet
check.
Signed-off-by: Jaehee Park <jhpark1013@gmail.com>
Suggested-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch adds a new protocol attribute to IPv4 and IPv6 addresses.
Inspiration was taken from the protocol attribute of routes. User space
applications like iproute2 can set/get the protocol with the Netlink API.
The attribute is stored as an 8-bit unsigned integer.
The protocol attribute is set by kernel for these categories:
- IPv4 and IPv6 loopback addresses
- IPv6 addresses generated from router announcements
- IPv6 link local addresses
User space may pass custom protocols, not defined by the kernel.
Grouping addresses on their origin is useful in scenarios where you want
to distinguish between addresses based on who added them, e.g. kernel
vs. user space.
Tagging addresses with a string label is an existing feature that could be
used as a solution. Unfortunately the max length of a label is
15 characters, and for compatibility reasons the label must be prefixed
with the name of the device followed by a colon. Since device names also
have a max length of 15 characters, only -1 characters is guaranteed to be
available for any origin tag, which is not that much.
A reference implementation of user space setting and getting protocols
is available for iproute2:
9a6ea18bd7
Signed-off-by: Jacques de Laval <Jacques.De.Laval@westermo.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220217150202.80802-1-Jacques.De.Laval@westermo.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This change introduces a new sysctl parameter, arp_evict_nocarrier.
When set (default) the ARP cache will be cleared on a NOCARRIER event.
This new option has been defaulted to '1' which maintains existing
behavior.
Clearing the ARP cache on NOCARRIER is relatively new, introduced by:
commit 859bd2ef1f
Author: David Ahern <dsahern@gmail.com>
Date: Thu Oct 11 20:33:49 2018 -0700
net: Evict neighbor entries on carrier down
The reason for this changes is to prevent the ARP cache from being
cleared when a wireless device roams. Specifically for wireless roams
the ARP cache should not be cleared because the underlying network has not
changed. Clearing the ARP cache in this case can introduce significant
delays sending out packets after a roam.
A user reported such a situation here:
https://lore.kernel.org/linux-wireless/CACsRnHWa47zpx3D1oDq9JYnZWniS8yBwW1h0WAVZ6vrbwL_S0w@mail.gmail.com/
After some investigation it was found that the kernel was holding onto
packets until ARP finished which resulted in this 1 second delay. It
was also found that the first ARP who-has was never responded to,
which is actually what caues the delay. This change is more or less
working around this behavior, but again, there is no reason to clear
the cache on a roam anyways.
As for the unanswered who-has, we know the packet made it OTA since
it was seen while monitoring. Why it never received a response is
unknown. In any case, since this is a problem on the AP side of things
all that can be done is to work around it until it is solved.
Some background on testing/reproducing the packet delay:
Hardware:
- 2 access points configured for Fast BSS Transition (Though I don't
see why regular reassociation wouldn't have the same behavior)
- Wireless station running IWD as supplicant
- A device on network able to respond to pings (I used one of the APs)
Procedure:
- Connect to first AP
- Ping once to establish an ARP entry
- Start a tcpdump
- Roam to second AP
- Wait for operstate UP event, and note the timestamp
- Start pinging
Results:
Below is the tcpdump after UP. It was recorded the interface went UP at
10:42:01.432875.
10:42:01.461871 ARP, Request who-has 192.168.254.1 tell 192.168.254.71, length 28
10:42:02.497976 ARP, Request who-has 192.168.254.1 tell 192.168.254.71, length 28
10:42:02.507162 ARP, Reply 192.168.254.1 is-at ac:86:74:55:b0:20, length 46
10:42:02.507185 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 1, length 64
10:42:02.507205 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 2, length 64
10:42:02.507212 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 3, length 64
10:42:02.507219 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 4, length 64
10:42:02.507225 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 5, length 64
10:42:02.507232 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 6, length 64
10:42:02.515373 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 1, length 64
10:42:02.521399 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 2, length 64
10:42:02.521612 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 3, length 64
10:42:02.521941 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 4, length 64
10:42:02.522419 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 5, length 64
10:42:02.523085 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 6, length 64
You can see the first ARP who-has went out very quickly after UP, but
was never responded to. Nearly a second later the kernel retries and
gets a response. Only then do the ping packets go out. If an ARP entry
is manually added prior to UP (after the cache is cleared) it is seen
that the first ping is never responded to, so its not only an issue with
ARP but with data packets in general.
As mentioned prior, the wireless interface was also monitored to verify
the ping/ARP packet made it OTA which was observed to be true.
Signed-off-by: James Prestwood <prestwoj@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since dynamic registration of the gifconf() helper is only used for
IPv4, and this can not be in a loadable module, this can be simplified
noticeably by turning it into a direct function call as a preparation
for cleaning up the compat handling.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduced in 65324144b5, the "proxy_arp_vlan" sysctl is a
per-interface sysctl to tune proxy ARP support for private VLANs.
While the "all" variant is exposed, it was a noop and never evaluated.
We use the usual "or" logic for this kind of sysctls.
Fixes: 65324144b5 ("net: RFC3069, private VLAN proxy arp support")
Signed-off-by: Vincent Bernat <vincent@bernat.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Introduced in 0eeb075fad, the "ignore_routes_with_linkdown" sysctl
ignores a route whose interface is down. It is provided as a
per-interface sysctl. However, while a "all" variant is exposed, it
was a noop since it was never evaluated. We use the usual "or" logic
for this kind of sysctls.
Tested with:
ip link add type veth # veth0 + veth1
ip link add type veth # veth1 + veth2
ip link set up dev veth0
ip link set up dev veth1 # link-status paired with veth0
ip link set up dev veth2
ip link set up dev veth3 # link-status paired with veth2
# First available path
ip -4 addr add 203.0.113.${uts#H}/24 dev veth0
ip -6 addr add 2001:db8:1::${uts#H}/64 dev veth0
# Second available path
ip -4 addr add 192.0.2.${uts#H}/24 dev veth2
ip -6 addr add 2001:db8:2::${uts#H}/64 dev veth2
# More specific route through first path
ip -4 route add 198.51.100.0/25 via 203.0.113.254 # via veth0
ip -6 route add 2001:db8:3::/56 via 2001:db8:1::ff # via veth0
# Less specific route through second path
ip -4 route add 198.51.100.0/24 via 192.0.2.254 # via veth2
ip -6 route add 2001:db8:3::/48 via 2001:db8:2::ff # via veth2
# H1: enable on "all"
# H2: enable on "veth0"
for v in ipv4 ipv6; do
case $uts in
H1)
sysctl -qw net.${v}.conf.all.ignore_routes_with_linkdown=1
;;
H2)
sysctl -qw net.${v}.conf.veth0.ignore_routes_with_linkdown=1
;;
esac
done
set -xe
# When veth0 is up, best route is through veth0
ip -o route get 198.51.100.1 | grep -Fw veth0
ip -o route get 2001:db8:3::1 | grep -Fw veth0
# When veth0 is down, best route should be through veth2 on H1/H2,
# but on veth0 on H2
ip link set down dev veth1 # down veth0
ip route show
[ $uts != H3 ] || ip -o route get 198.51.100.1 | grep -Fw veth0
[ $uts != H3 ] || ip -o route get 2001:db8:3::1 | grep -Fw veth0
[ $uts = H3 ] || ip -o route get 198.51.100.1 | grep -Fw veth2
[ $uts = H3 ] || ip -o route get 2001:db8:3::1 | grep -Fw veth2
Without this patch, the two last lines would fail on H1 (the one using
the "all" sysctl). With the patch, everything succeeds as expected.
Also document the sysctl in `ip-sysctl.rst`.
Fixes: 0eeb075fad ("net: ipv4 sysctl option to ignore routes when nexthop link is down")
Signed-off-by: Vincent Bernat <vincent@bernat.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ifa_list is protected by rcu, yet code doesn't reflect this.
Add the __rcu annotations and fix up all places that are now reported by
sparse.
I've done this in the same commit to not add intermediate patches that
result in new warnings.
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ifa_list is protected either by rcu or rtnl lock, but the
current iterators do not account for this.
This adds two iterators as replacement, a later patch in
the series will update them with the needed rcu/rtnl_dereference calls.
Its not done in this patch yet to avoid sparse warnings -- the fields
lack the proper __rcu annotation.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
in_dev lookup followed by IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN check
is called in several places, some with the rcu lock and others with the
rtnl held.
Move the check to a helper similar to what IPv6 has. Since the helper
can be invoked from either context use rcu_dereference_rtnl to
dereference ip_ptr.
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Similiar with ipv6 mcast commit 89225d1ce6 ("net: ipv6: mld: fix v1/v2
switchback timeout to rfc3810, 9.12.")
i) RFC3376 8.12. Older Version Querier Present Timeout says:
The Older Version Querier Interval is the time-out for transitioning
a host back to IGMPv3 mode once an older version query is heard.
When an older version query is received, hosts set their Older
Version Querier Present Timer to Older Version Querier Interval.
This value MUST be ((the Robustness Variable) times (the Query
Interval in the last Query received)) plus (one Query Response
Interval).
Currently we only use a hardcode value IGMP_V1/v2_ROUTER_PRESENT_TIMEOUT.
Fix it by adding two new items mr_qi(Query Interval) and mr_qri(Query Response
Interval) in struct in_device.
Now we can calculate the switchback time via (mr_qrv * mr_qi) + mr_qri.
We need update these values when receive IGMPv3 queries.
Reported-by: Ying Xu <yinxu@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch implements the feature described in rfc1812#section-5.3.5.2
and rfc2644. It allows the router to forward directed broadcast when
sysctl bc_forwarding is enabled.
Note that this feature could be done by iptables -j TEE, but it would
cause some problems:
- target TEE's gateway param has to be set with a specific address,
and it's not flexible especially when the route wants forward all
directed broadcasts.
- this duplicates the directed broadcasts so this may cause side
effects to applications.
Besides, to keep consistent with other os router like BSD, it's also
necessary to implement it in the route rx path.
Note that route cache needs to be flushed when bc_forwarding is
changed.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for IFA_RT_PRIORITY to ipv4 addresses.
If the metric is changed on an existing address then the new route
is inserted before removing the old one. Since the metric is one
of the route keys, the prefix route can not be replaced.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Files removed in 'net-next' had their license header updated
in 'net'. We take the remove from 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add extack to in_validator_info and in6_validator_info. Update the one
user of each, ipvlan, to return an error message for failures.
Only manual configuration of an address is plumbed in the IPv6 code path.
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit 1dced6a854 ("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 1dced6a854 ("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: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ipvlan code already knows how to detect when a duplicate address is
about to be assigned to an ipvlan device. However, that failure is not
propogated outward and leads to a silent failure.
Introduce a validation step at ip address creation time and allow device
drivers to register to validate the incoming ip addresses. The ipvlan
code is the first consumer. If it detects an address in use, we can
return an error to the user before beginning to commit the new ifa in
the networking code.
This can be especially useful if it is necessary to provision many
ipvlans in containers. The provisioning software (or operator) can use
this to detect situations where an ip address is unexpectedly in use.
Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Refactor inet_netconf_notify_devconf to take the event as an input arg.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch makes bad_mask return bool due to this particular function
only using either one or zero as its return value.
No functional change.
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch makes inet_ifa_match return bool due to this
particular function only using either one or zero as its return
value.
No functional change.
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
