The updating way of pmtu has changed, but documentation is still in the
old way. So this patch updates the interpretation of ip_no_pmtu_disc and
min_pmtu.
See commit 28d35bcdd3 ("net: ipv4: don't let PMTU updates increase
route MTU")
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
udp_mem is a vector of 3 INTEGERs, which is used to limit the number of
pages allowed for queueing by all UDP sockets.
However, sk_has_memory_pressure() in __sk_mem_raise_allocated() always
return false for udp, as memory pressure is not supported by udp, which
means that __sk_mem_raise_allocated() will fail once pages allocated
for udp socket exceeds udp_mem[0].
Therefor, udp_mem[0] is the only one that limit the number of pages.
However, the document of udp_mem just express that udp_mem[2] is the
limitation. So, just fix it.
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In most situations the neighbor discovery cache should be cleared on a
NOCARRIER event which is currently done unconditionally. But for wireless
roams the neighbor discovery cache can and should remain intact since
the underlying network has not changed.
This patch introduces a sysctl option ndisc_evict_nocarrier which can
be disabled by a wireless supplicant during a roam. This allows packets
to be sent after a roam immediately without having to wait for
neighbor discovery.
A user reported roughly a 1 second delay after a roam before packets
could be sent out (note, on IPv4). This delay was due to the ARP
cache being cleared. During testing of this same scenario using IPv6
no delay was noticed, but regardless there is no reason to clear
the ndisc cache for wireless roams.
Signed-off-by: James Prestwood <prestwoj@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
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>
This reverts the following patches :
- commit 2e05fcae83 ("tcp: fix compile error if !CONFIG_SYSCTL")
- commit 4f661542a4 ("tcp: fix zerocopy and notsent_lowat issues")
- commit 472c2e07ee ("tcp: add one skb cache for tx")
- commit 8b27dae5a2 ("tcp: add one skb cache for rx")
Having a cache of one skb (in each direction) per TCP socket is fragile,
since it can cause a significant increase of memory needs,
and not good enough for high speed flows anyway where more than one skb
is needed.
We want instead to add a generic infrastructure, with more flexible
per-cpu caches, for alien NUMA nodes.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Multiple complaints have been raised from the TFO users on the internet
stating that the TFO blackhole logic is too aggressive and gets falsely
triggered too often.
(e.g. https://blog.apnic.net/2021/07/05/tcp-fast-open-not-so-fast/)
Considering that most middleboxes no longer drop TFO packets, we decide
to disable the blackhole logic by setting
/proc/sys/net/ipv4/tcp_fastopen_blackhole_timeout_set to 0 by default.
Fixes: cf1ef3f071 ("net/tcp_fastopen: Disable active side TFO in certain scenarios")
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add documentation for new IOAM sysctls:
- ioam6_id and ioam6_id_wide: two per-namespace sysctls
- ioam6_enabled, ioam6_id and ioam6_id_wide: three per-interface sysctls
Example of IOAM configuration based on the following simple topology:
_____ _____ _____
| | eth0 eth0 | | eth1 eth0 | |
| A |.----------.| B |.----------.| C |
|_____| |_____| |_____|
1) Node and interface IDs can be configured for IOAM:
# IOAM ID of A = 1, IOAM ID of A.eth0 = 11
(A) sysctl -w net.ipv6.ioam6_id=1
(A) sysctl -w net.ipv6.conf.eth0.ioam6_id=11
# IOAM ID of B = 2, IOAM ID of B.eth0 = 21, IOAM ID of B.eth1 = 22
(B) sysctl -w net.ipv6.ioam6_id=2
(B) sysctl -w net.ipv6.conf.eth0.ioam6_id=21
(B) sysctl -w net.ipv6.conf.eth1.ioam6_id=22
# IOAM ID of C = 3, IOAM ID of C.eth0 = 31
(C) sysctl -w net.ipv6.ioam6_id=3
(C) sysctl -w net.ipv6.conf.eth0.ioam6_id=31
Note that "_wide" IDs equivalents can be configured the same way.
2) Each node can be configured to form an IOAM domain. For instance,
we allow IOAM from A to C only (not the reverse path), i.e. enable
IOAM on ingress for B.eth0 and C.eth0:
(B) sysctl -w net.ipv6.conf.eth0.ioam6_enabled=1
(C) sysctl -w net.ipv6.conf.eth0.ioam6_enabled=1
3) An IOAM domain (e.g. ID=123) is defined and made known to each node:
(A) ip ioam namespace add 123
(B) ip ioam namespace add 123
(C) ip ioam namespace add 123
4) Finally, an IOAM Pre-allocated Trace can be inserted in traffic sent
by A when C (e.g. db02::2) is the destination:
(A) ip -6 route add db02::2/128 encap ioam6 trace type 0x800000 ns 123
size 12 dev eth0
Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
These is no need to wait for 'interval' period for the next probe
if the last probe is already acked in search state. The 'interval'
period waiting should be only for probe failure timeout and the
current pmtu check when it's in search complete state.
This change will shorten the probe time a lot in search state, and
also fix the document accordingly.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
PLPMTUD can be enabled by doing 'sysctl -w net.sctp.probe_interval=n'.
'n' is the interval for PLPMTUD probe timer in milliseconds, and it
can't be less than 5000 if it's not 0.
All asoc/transport's PLPMTUD in a new socket will be enabled by default.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit adds a new sysctl option: net.ipv4.tcp_migrate_req. If this
option is enabled or eBPF program is attached, we will be able to migrate
child sockets from a listener to another in the same reuseport group after
close() or shutdown() syscalls.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210612123224.12525-2-kuniyu@amazon.co.jp
Add a new multipath hash policy where the packet fields used for hash
calculation are determined by user space via the
fib_multipath_hash_fields sysctl that was introduced in the previous
patch.
The current set of available packet fields includes both outer and inner
fields, which requires two invocations of the flow dissector. Avoid
unnecessary dissection of the outer or inner flows by skipping
dissection if none of the outer or inner fields are required.
In accordance with the existing policies, when an skb is not available,
packet fields are extracted from the provided flow key. In which case,
only outer fields are considered.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
A subsequent patch will add a new multipath hash policy where the packet
fields used for multipath hash calculation are determined by user space.
This patch adds a sysctl that allows user space to set these fields.
The packet fields are represented using a bitmask and are common between
IPv4 and IPv6 to allow user space to use the same numbering across both
protocols. For example, to hash based on standard 5-tuple:
# sysctl -w net.ipv6.fib_multipath_hash_fields=0x0037
net.ipv6.fib_multipath_hash_fields = 0x0037
To avoid introducing holes in 'struct netns_sysctl_ipv6', move the
'bindv6only' field after the multipath hash fields.
The kernel rejects unknown fields, for example:
# sysctl -w net.ipv6.fib_multipath_hash_fields=0x1000
sysctl: setting key "net.ipv6.fib_multipath_hash_fields": Invalid argument
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new multipath hash policy where the packet fields used for hash
calculation are determined by user space via the
fib_multipath_hash_fields sysctl that was introduced in the previous
patch.
The current set of available packet fields includes both outer and inner
fields, which requires two invocations of the flow dissector. Avoid
unnecessary dissection of the outer or inner flows by skipping
dissection if none of the outer or inner fields are required.
In accordance with the existing policies, when an skb is not available,
packet fields are extracted from the provided flow key. In which case,
only outer fields are considered.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
A subsequent patch will add a new multipath hash policy where the packet
fields used for multipath hash calculation are determined by user space.
This patch adds a sysctl that allows user space to set these fields.
The packet fields are represented using a bitmask and are common between
IPv4 and IPv6 to allow user space to use the same numbering across both
protocols. For example, to hash based on standard 5-tuple:
# sysctl -w net.ipv4.fib_multipath_hash_fields=0x0037
net.ipv4.fib_multipath_hash_fields = 0x0037
The kernel rejects unknown fields, for example:
# sysctl -w net.ipv4.fib_multipath_hash_fields=0x1000
sysctl: setting key "net.ipv4.fib_multipath_hash_fields": Invalid argument
More fields can be added in the future, if needed.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
- keep the ZC code, drop the code related to reinit
net/bridge/netfilter/ebtables.c
- fix build after move to net_generic
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Let's have all seg6 sysctl at the same place.
Fixes: a6dc6670cd ("ipv6: sr: Add documentation for seg_flowlabel sysctl")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If there is overlapp between ip_local_port_range and ip_local_reserved_ports with a huge reserved block, it will affect probability of selecting ephemeral ports, see file net/ipv4/inet_hashtables.c:723
int __inet_hash_connect(
...
for (i = 0; i < remaining; i += 2, port += 2) {
if (unlikely(port >= high))
port -= remaining;
if (inet_is_local_reserved_port(net, port))
continue;
E.g. if there is reserved block of 10000 ports, two ports right after this block will be 5000 more likely selected than others.
If this was intended, we can/should add note into documentation as proposed in this commit, otherwise we should think about different solution. One option could be mapping table of continuous port ranges. Second option could be letting user to modify step (port+=2) in above loop, e.g. using new sysctl parameter.
Signed-off-by: Otto Hollmann <otto.hollmann@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Section 8 of RFC 8335 specifies potential security concerns of
responding to PROBE requests, and states that nodes that support PROBE
functionality MUST be able to enable/disable responses and that
responses MUST be disabled by default
Signed-off-by: Andreas Roeseler <andreas.a.roeseler@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp_rmem[1] has been changed to 131072, we should update the documentation
to reflect this.
Fixes: a337531b94 ("tcp: up initial rmem to 128KB and SYN rwin to around 64KB")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Zhibin Liu <zhibinliu@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Provide documentation for src_valid_mark sysctl, which was added
in commit 28f6aeea3f ("net: restore ip source validation").
Signed-off-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the value '2' to 'fib_notify_on_flag_change' to allow sending
notifications only for failed route installation.
Separate value is added for such notifications because there are less of
them, so they do not impact performance and some users will find them more
important.
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the value '2' to 'fib_notify_on_flag_change' to allow sending
notifications only for failed route installation.
Separate value is added for such notifications because there are less of
them, so they do not impact performance and some users will find them more
important.
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After installing a route to the kernel, user space receives an
acknowledgment, which means the route was installed in the kernel,
but not necessarily in hardware.
The asynchronous nature of route installation in hardware can lead
to a routing daemon advertising a route before it was actually installed in
hardware. This can result in packet loss or mis-routed packets until the
route is installed in hardware.
It is also possible for a route already installed in hardware to change
its action and therefore its flags. For example, a host route that is
trapping packets can be "promoted" to perform decapsulation following
the installation of an IPinIP/VXLAN tunnel.
Emit RTM_NEWROUTE notifications whenever RTM_F_OFFLOAD/RTM_F_TRAP flags
are changed. The aim is to provide an indication to user-space
(e.g., routing daemons) about the state of the route in hardware.
Introduce a sysctl that controls this behavior.
Keep the default value at 0 (i.e., do not emit notifications) for several
reasons:
- Multiple RTM_NEWROUTE notification per-route might confuse existing
routing daemons.
- Convergence reasons in routing daemons.
- The extra notifications will negatively impact the insertion rate.
- Not all users are interested in these notifications.
Move fib6_info_hw_flags_set() to C file because it is no longer a short
function.
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
After installing a route to the kernel, user space receives an
acknowledgment, which means the route was installed in the kernel,
but not necessarily in hardware.
The asynchronous nature of route installation in hardware can lead to a
routing daemon advertising a route before it was actually installed in
hardware. This can result in packet loss or mis-routed packets until the
route is installed in hardware.
It is also possible for a route already installed in hardware to change
its action and therefore its flags. For example, a host route that is
trapping packets can be "promoted" to perform decapsulation following
the installation of an IPinIP/VXLAN tunnel.
Emit RTM_NEWROUTE notifications whenever RTM_F_OFFLOAD/RTM_F_TRAP flags
are changed. The aim is to provide an indication to user-space
(e.g., routing daemons) about the state of the route in hardware.
Introduce a sysctl that controls this behavior.
Keep the default value at 0 (i.e., do not emit notifications) for several
reasons:
- Multiple RTM_NEWROUTE notification per-route might confuse existing
routing daemons.
- Convergence reasons in routing daemons.
- The extra notifications will negatively impact the insertion rate.
- Not all users are interested in these notifications.
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Acked-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
drivers/net/can/dev.c
b552766c87 ("can: dev: prevent potential information leak in can_fill_info()")
3e77f70e73 ("can: dev: move driver related infrastructure into separate subdir")
0a042c6ec9 ("can: dev: move netlink related code into seperate file")
Code move.
drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
57ac4a31c4 ("net/mlx5e: Correctly handle changing the number of queues when the interface is down")
214baf2287 ("net/mlx5e: Support HTB offload")
Adjacent code changes
net/switchdev/switchdev.c
20776b465c ("net: switchdev: don't set port_obj_info->handled true when -EOPNOTSUPP")
ffb68fc58e ("net: switchdev: remove the transaction structure from port object notifiers")
bae33f2b5a ("net: switchdev: remove the transaction structure from port attributes")
Transaction parameter gets dropped otherwise keep the fix.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
For IPv4, default route is learned via DHCPv4 and user is allowed to change
metric using config etc/network/interfaces. But for IPv6, default route can
be learned via RA, for which, currently a fixed metric value 1024 is used.
Ideally, user should be able to configure metric on default route for IPv6
similar to IPv4. This patch adds sysctl for the same.
Logs:
For IPv4:
Config in etc/network/interfaces:
auto eth0
iface eth0 inet dhcp
metric 4261413864
IPv4 Kernel Route Table:
$ ip route list
default via 172.21.47.1 dev eth0 metric 4261413864
FRR Table, if a static route is configured:
[In real scenario, it is useful to prefer BGP learned default route over DHCPv4 default route.]
Codes: K - kernel route, C - connected, S - static, R - RIP,
O - OSPF, I - IS-IS, B - BGP, P - PIM, E - EIGRP, N - NHRP,
T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
> - selected route, * - FIB route
S>* 0.0.0.0/0 [20/0] is directly connected, eth0, 00:00:03
K 0.0.0.0/0 [254/1000] via 172.21.47.1, eth0, 6d08h51m
i.e. User can prefer Default Router learned via Routing Protocol in IPv4.
Similar behavior is not possible for IPv6, without this fix.
After fix [for IPv6]:
sudo sysctl -w net.ipv6.conf.eth0.net.ipv6.conf.eth0.ra_defrtr_metric=1996489705
IP monitor: [When IPv6 RA is received]
default via fe80::xx16:xxxx:feb3:ce8e dev eth0 proto ra metric 1996489705 pref high
Kernel IPv6 routing table
$ ip -6 route list
default via fe80::be16:65ff:feb3:ce8e dev eth0 proto ra metric 1996489705 expires 21sec hoplimit 64 pref high
FRR Table, if a static route is configured:
[In real scenario, it is useful to prefer BGP learned default route over IPv6 RA default route.]
Codes: K - kernel route, C - connected, S - static, R - RIPng,
O - OSPFv3, I - IS-IS, B - BGP, N - NHRP, T - Table,
v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
> - selected route, * - FIB route
S>* ::/0 [20/0] is directly connected, eth0, 00:00:06
K ::/0 [119/1001] via fe80::xx16:xxxx:feb3:ce8e, eth0, 6d07h43m
If the metric is changed later, the effect will be seen only when next IPv6
RA is received, because the default route must be fully controlled by RA msg.
Below metric is changed from 1996489705 to 1996489704.
$ sudo sysctl -w net.ipv6.conf.eth0.ra_defrtr_metric=1996489704
net.ipv6.conf.eth0.ra_defrtr_metric = 1996489704
IP monitor:
[On next IPv6 RA msg, Kernel deletes prev route and installs new route with updated metric]
Deleted default via fe80::xx16:xxxx:feb3:ce8e dev eth0 proto ra metric 1996489705 expires 3sec hoplimit 64 pref high
default via fe80::xx16:xxxx:feb3:ce8e dev eth0 proto ra metric 1996489704 pref high
Signed-off-by: Praveen Chaudhary <pchaudhary@linkedin.com>
Signed-off-by: Zhenggen Xu <zxu@linkedin.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20210125214430.24079-1-pchaudhary@linkedin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch adds documentation for sysctl conf/all/disable_ipv6 and
conf/default/disable_ipv6 settings which is currently missing.
Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20210121150244.20483-1-pali@kernel.org
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>
This patch is to enable udp tunneling socks by calling
sctp_udp_sock_start() in sctp_ctrlsock_init(), and
sctp_udp_sock_stop() in sctp_ctrlsock_exit().
Also add sysctl udp_port to allow changing the listening
sock's port by users.
Wit this patch, the whole sctp over udp feature can be
enabled and used.
v1->v2:
- Also update ctl_sock udp_port in proc_sctp_do_udp_port()
where netns udp_port gets changed.
v2->v3:
- Call htons() when setting sk udp_port from netns udp_port.
v3->v4:
- Not call sctp_udp_sock_start() when new_value is 0.
- Add udp_port entry in ip-sysctl.rst.
v4->v5:
- Not call sctp_udp_sock_start/stop() in sctp_ctrlsock_init/exit().
- Improve the description of udp_port in ip-sysctl.rst.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
encap_port is added as per netns/sock/assoc/transport, and the
latter one's encap_port inherits the former one's by default.
The transport's encap_port value would mostly decide if one
packet should go out with udp encapsulated or not.
This patch also allows users to set netns' encap_port by sysctl.
v1->v2:
- Change to define encap_port as __be16 for sctp_sock, asoc and
transport.
v2->v3:
- No change.
v3->v4:
- Add 'encap_port' entry in ip-sysctl.rst.
v4->v5:
- Improve the description of encap_port in ip-sysctl.rst.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Keyu Man reported that the ICMP rate limiter could be used
by attackers to get useful signal. Details will be provided
in an upcoming academic publication.
Our solution is to add some noise, so that the attackers
no longer can get help from the predictable token bucket limiter.
Fixes: 4cdf507d54 ("icmp: add a global rate limitation")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Drop the doubled word "that".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement the upcoming rev of RFC4941 (IPv6 temporary addresses):
https://tools.ietf.org/html/draft-ietf-6man-rfc4941bis-09
* Reduces the default Valid Lifetime to 2 days
The number of extra addresses employed when Valid Lifetime was
7 days exacerbated the stress caused on network
elements/devices. Additionally, the motivation for temporary
addresses is indeed privacy and reduced exposure. With a
default Valid Lifetime of 7 days, an address that becomes
revealed by active communication is reachable and exposed for
one whole week. The only use case for a Valid Lifetime of 7
days could be some application that is expecting to have long
lived connections. But if you want to have a long lived
connections, you shouldn't be using a temporary address in the
first place. Additionally, in the era of mobile devices, general
applications should nevertheless be prepared and robust to
address changes (e.g. nodes swap wifi <-> 4G, etc.)
* Employs different IIDs for different prefixes
To avoid network activity correlation among addresses configured
for different prefixes
* Uses a simpler algorithm for IID generation
No need to store "history" anywhere
Signed-off-by: Fernando Gont <fgont@si6networks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a sysctl to control hrtimer slack, default of 100 usec.
This gives the opportunity to reduce system overhead,
and help very short RTT flows.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Not much to be done here:
- add SPDX header;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
- add SPDX header;
- adjust titles and chapters, adding proper markups;
- mark code blocks and literals as such;
- mark lists as such;
- mark tables as such;
- use footnote markup;
- adjust identation, whitespaces and blank lines;
- add to networking/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
xu xin