diff options
author | Amit Cohen <amcohen@nvidia.com> | 2021-02-01 21:47:52 +0200 |
---|---|---|
committer | Jakub Kicinski <kuba@kernel.org> | 2021-02-02 17:45:59 -0800 |
commit | 680aea08e78c003292415518ad270bc20f9c80b1 (patch) | |
tree | 1215e16fb0586bf8b296e70a26c6f4ccd031cd31 /include | |
parent | 1e7bdec6bbc7816cdc6a093374f4bf4e732c3d44 (diff) |
net: ipv4: Emit notification when fib hardware flags are changed
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>
Diffstat (limited to 'include')
-rw-r--r-- | include/net/netns/ipv4.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index 8e4fcac4df72..70a2a085dd1a 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -188,6 +188,8 @@ struct netns_ipv4 { int sysctl_udp_wmem_min; int sysctl_udp_rmem_min; + int sysctl_fib_notify_on_flag_change; + #ifdef CONFIG_NET_L3_MASTER_DEV int sysctl_udp_l3mdev_accept; #endif |