Since commit 58e0be1ef6 ("net: use struct_group to copy ip/ipv6
header addresses"), ip and ipv6 headers started to use the __struct_group
definition, which is defined at include/uapi/linux/stddef.h. However,
linux/stddef.h isn't explicitly included in include/uapi/linux/{ip,ipv6}.h,
which breaks build of xskxceiver bpf selftest if you install the uapi
headers in the system:
$ make V=1 xskxceiver -C tools/testing/selftests/bpf
...
make: Entering directory '(...)/tools/testing/selftests/bpf'
gcc -g -O0 -rdynamic -Wall -Werror (...)
In file included from xskxceiver.c:79:
/usr/include/linux/ip.h:103:9: error: expected specifier-qualifier-list before ‘__struct_group’
103 | __struct_group(/* no tag */, addrs, /* no attrs */,
| ^~~~~~~~~~~~~~
...
Include the missing <linux/stddef.h> dependency in ip.h and do the
same for the ipv6.h header.
Fixes: 58e0be1ef6 ("net: use struct_group to copy ip/ipv6 header addresses")
Signed-off-by: Herton R. Krzesinski <herton@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
kernel test robot reported warnings when build bonding module with
make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/net/bonding/:
from ../drivers/net/bonding/bond_main.c:35:
In function ‘fortify_memcpy_chk’,
inlined from ‘iph_to_flow_copy_v4addrs’ at ../include/net/ip.h:566:2,
inlined from ‘bond_flow_ip’ at ../drivers/net/bonding/bond_main.c:3984:3:
../include/linux/fortify-string.h:413:25: warning: call to ‘__read_overflow2_field’ declared with attribute warning: detected read beyond size of f
ield (2nd parameter); maybe use struct_group()? [-Wattribute-warning]
413 | __read_overflow2_field(q_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In function ‘fortify_memcpy_chk’,
inlined from ‘iph_to_flow_copy_v6addrs’ at ../include/net/ipv6.h:900:2,
inlined from ‘bond_flow_ip’ at ../drivers/net/bonding/bond_main.c:3994:3:
../include/linux/fortify-string.h:413:25: warning: call to ‘__read_overflow2_field’ declared with attribute warning: detected read beyond size of f
ield (2nd parameter); maybe use struct_group()? [-Wattribute-warning]
413 | __read_overflow2_field(q_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This is because we try to copy the whole ip/ip6 address to the flow_key,
while we only point the to ip/ip6 saddr. Note that since these are UAPI
headers, __struct_group() is used to avoid the compiler warnings.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: c3f8324188 ("net: Add full IPv6 addresses to flow_keys")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20221115142400.1204786-1-liuhangbin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].
This code was transformed with the help of Coccinelle:
(linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch)
@@
identifier S, member, array;
type T1, T2;
@@
struct S {
...
T1 member;
T2 array[
- 0
];
};
-fstrict-flex-arrays=3 is coming and we need to land these changes
to prevent issues like these in the short future:
../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destination buffer has size 0,
but the source string has length 2 (including NUL byte) [-Wfortify-source]
strcpy(de3->name, ".");
^
Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If
this breaks anything, we can use a union with a new member name.
[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/78
Build-tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%25lkp@intel.com/
Acked-by: Dan Williams <dan.j.williams@intel.com> # For ndctl.h
Signed-off-by: Gustavo A. R. Silva <gustavoars@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>
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>
Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be. This makes it hard for
compliance tools to determine the correct license.
Update these files with an SPDX license identifier. The identifier was
chosen based on the license information in the file.
GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:
NOTE! This copyright does *not* cover user programs that use kernel
services by normal system calls - this is merely considered normal use
of the kernel, and does *not* fall under the heading of "derived work".
This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.
Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier. The format
is:
((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)
SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text. The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne. See the previous patch in this series for the
methodology of how this patch was researched.
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>
In certain 802.11 wireless deployments, there will be ARP proxies
that use knowledge of the network to correctly answer requests.
To prevent gratuitous ARP frames on the shared medium from being
a problem, on such deployments wireless needs to drop them.
Enable this by providing an option called "drop_gratuitous_arp".
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In order to solve a problem with 802.11, the so-called hole-196 attack,
add an option (sysctl) called "drop_unicast_in_l2_multicast" which, if
enabled, causes the stack to drop IPv4 unicast packets encapsulated in
link-layer multi- or broadcast frames. Such frames can (as an attack)
be created by any member of the same wireless network and transmitted
as valid encrypted frames since the symmetric key for broadcast frames
is shared between all stations.
Additionally, enabling this option provides compliance with a SHOULD
clause of RFC 1122.
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This feature is only enabled with the new per-interface or ipv4 global
sysctls called 'ignore_routes_with_linkdown'.
net.ipv4.conf.all.ignore_routes_with_linkdown = 0
net.ipv4.conf.default.ignore_routes_with_linkdown = 0
net.ipv4.conf.lo.ignore_routes_with_linkdown = 0
...
When the above sysctls are set, will report to userspace that a route is
dead and will no longer resolve to this nexthop when performing a fib
lookup. This will signal to userspace that the route will not be
selected. The signalling of a RTNH_F_DEAD is only passed to userspace
if the sysctl is enabled and link is down. This was done as without it
the netlink listeners would have no idea whether or not a nexthop would
be selected. The kernel only sets RTNH_F_DEAD internally if the
interface has IFF_UP cleared.
With the new sysctl set, the following behavior can be observed
(interface p8p1 is link-down):
default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1 proto kernel scope link src 10.0.5.15
70.0.0.0/24 dev p7p1 proto kernel scope link src 70.0.0.1
80.0.0.0/24 dev p8p1 proto kernel scope link src 80.0.0.1 dead linkdown
90.0.0.0/24 via 80.0.0.2 dev p8p1 metric 1 dead linkdown
90.0.0.0/24 via 70.0.0.2 dev p7p1 metric 2
90.0.0.1 via 70.0.0.2 dev p7p1 src 70.0.0.1
cache
local 80.0.0.1 dev lo src 80.0.0.1
cache <local>
80.0.0.2 via 10.0.5.2 dev p9p1 src 10.0.5.15
cache
While the route does remain in the table (so it can be modified if
needed rather than being wiped away as it would be if IFF_UP was
cleared), the proper next-hop is chosen automatically when the link is
down. Now interface p8p1 is linked-up:
default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1 proto kernel scope link src 10.0.5.15
70.0.0.0/24 dev p7p1 proto kernel scope link src 70.0.0.1
80.0.0.0/24 dev p8p1 proto kernel scope link src 80.0.0.1
90.0.0.0/24 via 80.0.0.2 dev p8p1 metric 1
90.0.0.0/24 via 70.0.0.2 dev p7p1 metric 2
192.168.56.0/24 dev p2p1 proto kernel scope link src 192.168.56.2
90.0.0.1 via 80.0.0.2 dev p8p1 src 80.0.0.1
cache
local 80.0.0.1 dev lo src 80.0.0.1
cache <local>
80.0.0.2 dev p8p1 src 80.0.0.1
cache
and the output changes to what one would expect.
If the sysctl is not set, the following output would be expected when
p8p1 is down:
default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1 proto kernel scope link src 10.0.5.15
70.0.0.0/24 dev p7p1 proto kernel scope link src 70.0.0.1
80.0.0.0/24 dev p8p1 proto kernel scope link src 80.0.0.1 linkdown
90.0.0.0/24 via 80.0.0.2 dev p8p1 metric 1 linkdown
90.0.0.0/24 via 70.0.0.2 dev p7p1 metric 2
Since the dead flag does not appear, there should be no expectation that
the kernel would skip using this route due to link being down.
v2: Split kernel changes into 2 patches, this actually makes a
behavioral change if the sysctl is set. Also took suggestion from Alex
to simplify code by only checking sysctl during fib lookup and
suggestion from Scott to add a per-interface sysctl.
v3: Code clean-ups to make it more readable and efficient as well as a
reverse path check fix.
v4: Drop binary sysctl
v5: Whitespace fixups from Dave
v6: Style changes from Dave and checkpatch suggestions
v7: One more checkpatch fixup
Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: Dinesh Dutt <ddutt@cumulusnetworks.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/wireless/iwlwifi/pcie/trans.c
include/linux/inetdevice.h
The inetdevice.h conflict involves moving the IPV4_DEVCONF values
into a UAPI header, overlapping additions of some new entries.
The iwlwifi conflict is a context overlap.
Signed-off-by: David S. Miller <davem@davemloft.net>
IP sends device configuration (see inet_fill_link_af) as an array
in the netlink information, but the indices in that array are not
exposed to userspace through any current santized header file.
It was available back in 2.6.32 (in /usr/include/linux/sysctl.h)
but was broken by:
commit 02291680ff
Author: Eric W. Biederman <ebiederm@xmission.com>
Date: Sun Feb 14 03:25:51 2010 +0000
net ipv4: Decouple ipv4 interface parameters from binary sysctl numbers
Eric was solving the sysctl problem but then the indices were re-exposed
by a later addition of devconf support for IPV4
commit 9f0f7272ac
Author: Thomas Graf <tgraf@infradead.org>
Date: Tue Nov 16 04:32:48 2010 +0000
ipv4: AF_INET link address family
Putting them in /usr/include/linux/ip.h seemed the logical match
for the DEVCONF_ definitions for IPV6 in /usr/include/linux/ip6.h
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
