linux/tools
David Ahern 40867d74c3 net: Add l3mdev index to flow struct and avoid oif reset for port devices
The fundamental premise of VRF and l3mdev core code is binding a socket
to a device (l3mdev or netdev with an L3 domain) to indicate L3 scope.
Legacy code resets flowi_oif to the l3mdev losing any original port
device binding. Ben (among others) has demonstrated use cases where the
original port device binding is important and needs to be retained.
This patch handles that by adding a new entry to the common flow struct
that can indicate the l3mdev index for later rule and table matching
avoiding the need to reset flowi_oif.

In addition to allowing more use cases that require port device binds,
this patch brings a few datapath simplications:

1. l3mdev_fib_rule_match is only called when walking fib rules and
   always after l3mdev_update_flow. That allows an optimization to bail
   early for non-VRF type uses cases when flowi_l3mdev is not set. Also,
   only that index needs to be checked for the FIB table id.

2. l3mdev_update_flow can be called with flowi_oif set to a l3mdev
   (e.g., VRF) device. By resetting flowi_oif only for this case the
   FLOWI_FLAG_SKIP_NH_OIF flag is not longer needed and can be removed,
   removing several checks in the datapath. The flowi_iif path can be
   simplified to only be called if the it is not loopback (loopback can
   not be assigned to an L3 domain) and the l3mdev index is not already
   set.

3. Avoid another device lookup in the output path when the fib lookup
   returns a reject failure.

Note: 2 functional tests for local traffic with reject fib rules are
updated to reflect the new direct failure at FIB lookup time for ping
rather than the failure on packet path. The current code fails like this:

    HINT: Fails since address on vrf device is out of device scope
    COMMAND: ip netns exec ns-A ping -c1 -w1 -I eth1 172.16.3.1
    ping: Warning: source address might be selected on device other than: eth1
    PING 172.16.3.1 (172.16.3.1) from 172.16.3.1 eth1: 56(84) bytes of data.

    --- 172.16.3.1 ping statistics ---
    1 packets transmitted, 0 received, 100% packet loss, time 0ms

where the test now directly fails:

    HINT: Fails since address on vrf device is out of device scope
    COMMAND: ip netns exec ns-A ping -c1 -w1 -I eth1 172.16.3.1
    ping: connect: No route to host

Signed-off-by: David Ahern <dsahern@kernel.org>
Tested-by: Ben Greear <greearb@candelatech.com>
Link: https://lore.kernel.org/r/20220314204551.16369-1-dsahern@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-15 20:20:02 -07:00
..
accounting delayacct: track delays from memory compact 2022-01-20 08:52:55 +02:00
arch - Mitigate Spectre v2-type Branch History Buffer attacks on machines 2022-03-07 17:29:47 -08:00
bootconfig bootconfig: Cleanup dummy headers in tools/bootconfig 2021-10-10 22:16:02 -04:00
bpf bpftool: Remove redundant slashes 2022-02-28 16:06:21 +01:00
build Merge remote-tracking branch 'torvalds/master' into perf/core 2022-01-13 10:20:59 -03:00
cgroup tools/cgroup/slabinfo: update to work with struct slab 2022-02-21 11:34:49 +01:00
counter tools/counter: Create Counter tools 2021-10-17 10:54:16 +01:00
debugging
edid
firewire
firmware
gpio
hv
iio iio: event_monitor: Flush output on event 2021-12-16 12:20:35 +00:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-03-03 11:55:12 -08:00
io_uring
kvm/kvm_stat KVM: kvm_stat: do not show halt_wait_ns 2021-10-18 14:07:18 -04:00
laptop
leds
lib libbpf: Add a check to ensure that page_cnt is non-zero 2022-03-03 16:23:22 +01:00
memory-model tools/memory-model: litmus: Add two tests for unlock(A)+lock(B) ordering 2021-11-30 17:47:08 -08:00
objtool objtool: Fix truncated string warning 2022-01-24 10:09:06 -08:00
pci
pcmcia
perf Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-03-03 11:55:12 -08:00
power More ACPI updates for 5.17-rc1 2022-01-18 08:51:51 +02:00
rcu
scripts tools: Ignore errors from `which' when searching a GCC toolchain 2022-02-01 23:04:12 +01:00
spi
testing net: Add l3mdev index to flow struct and avoid oif reset for port devices 2022-03-15 20:20:02 -07:00
thermal/tmon thermal: tools: tmon: remove unneeded local variable 2021-11-24 17:26:13 +01:00
time
tracing rtla/osnoise: Fix error message when failing to enable trace instance 2022-02-25 21:05:30 -05:00
usb
virtio tools/virtio: handle fallout from folio work 2022-03-06 06:06:50 -05:00
vm tools/vm/page-types.c: print file offset in hexadecimal 2021-11-06 13:30:40 -07:00
wmi
Makefile tools/lib/lockdep: drop liblockdep 2021-11-12 11:07:17 -08:00