linux-toradex.git/tools/testing/selftests/net/pmtu.sh, branch v6.3

selftests/net: Find nettest in current directory

2022-11-21T12:58:26+00:00

The `nettest` binary, built from `selftests/net/nettest.c`,
was expected to be found in the path during test execution of
`fcnal-test.sh` and `pmtu.sh`, leading to tests getting
skipped when the binary is not installed in the system, as can
be seen in these logs found in the wild [1]:

  # TEST: vti4: PMTU exceptions                                         [SKIP]
  [  350.600250] IPv6: ADDRCONF(NETDEV_CHANGE): veth_b: link becomes ready
  [  350.607421] IPv6: ADDRCONF(NETDEV_CHANGE): veth_a: link becomes ready
  # 'nettest' command not found; skipping tests
  #   xfrm6udp not supported
  # TEST: vti6: PMTU exceptions (ESP-in-UDP)                            [SKIP]
  [  351.605102] IPv6: ADDRCONF(NETDEV_CHANGE): veth_b: link becomes ready
  [  351.612243] IPv6: ADDRCONF(NETDEV_CHANGE): veth_a: link becomes ready
  # 'nettest' command not found; skipping tests
  #   xfrm4udp not supported

The `unicast_extensions.sh` tests also rely on `nettest`, but
it runs fine there because it looks for the binary in the
current working directory [2]:

The same mechanism that works for the Unicast extensions tests
is here copied over to the PMTU and functional tests.

[1] https://lkft.validation.linaro.org/scheduler/job/5839508#L6221
[2] https://lkft.validation.linaro.org/scheduler/job/5839508#L7958

Signed-off-by: Daniel Díaz 
Signed-off-by: David S. Miller

selftest: net: Test IPv4 PMTU exceptions with DSCP and ECN

2022-03-18T21:06:45+00:00

Add two tests to pmtu.sh, for verifying that PMTU exceptions get
properly created for routes that don't belong to the main table.

A fib-rule based on the packet's DSCP field is used to jump to the
correct table. ECN shouldn't interfere with this process, so each test
has two components: one that only sets DSCP and one that sets both DSCP
and ECN.

One of the test triggers PMTU exceptions using ICMP Echo Requests, the
other using UDP packets (to test different handlers in the kernel).

A few adjustments are necessary in the rest of the script to allow
policy routing scenarios:

  * Add global variable rt_table that allows setup_routing_*() to
    add routes to a specific routing table. By default rt_table is set
    to "main", so existing tests don't need to be modified.

  * Another global variable, policy_mark, is used to define which
    dsfield value is used for policy routing. This variable has no
    effect on tests that don't use policy routing.

  * The UDP version of the test uses socat. So cleanup() now also need
    to kill socat PIDs.

  * route_get_dst_pmtu_from_exception() and route_get_dst_exception()
    now take an optional third argument specifying the dsfield. If
    not specified, 0 is used, so existing users don't need to be
    modified.

Signed-off-by: Guillaume Nault 
Reviewed-by: David Ahern 
Signed-off-by: Jakub Kicinski

selftests: pmtu.sh: Kill nettest processes launched in subshell.

2022-03-10T04:23:32+00:00

When using "run_cmd  &", then "$!" refers to the PID of the
subshell used to run , not the command itself. Therefore
nettest_pids actually doesn't contain the list of the nettest commands
running in the background. So cleanup() can't kill them and the nettest
processes run until completion (fortunately they have a 5s timeout).

Fix this by defining a new command for running processes in the
background, for which "$!" really refers to the PID of the command run.

Also, double quote variables on the modified lines, to avoid shellcheck
warnings.

Fixes: ece1278a9b81 ("selftests: net: add ESP-in-UDP PMTU test")
Signed-off-by: Guillaume Nault 
Reviewed-by: Shuah Khan 
Signed-off-by: Jakub Kicinski

selftests: pmtu.sh: Kill tcpdump processes launched by subshell.

2022-03-10T04:23:15+00:00

The cleanup() function takes care of killing processes launched by the
test functions. It relies on variables like ${tcpdump_pids} to get the
relevant PIDs. But tests are run in their own subshell, so updated
*_pids values are invisible to other shells. Therefore cleanup() never
sees any process to kill:

$ ./tools/testing/selftests/net/pmtu.sh -t pmtu_ipv4_exception
TEST: ipv4: PMTU exceptions                                         [ OK ]
TEST: ipv4: PMTU exceptions - nexthop objects                       [ OK ]

$ pgrep -af tcpdump
6084 tcpdump -s 0 -i veth_A-R1 -w pmtu_ipv4_exception_veth_A-R1.pcap
6085 tcpdump -s 0 -i veth_R1-A -w pmtu_ipv4_exception_veth_R1-A.pcap
6086 tcpdump -s 0 -i veth_R1-B -w pmtu_ipv4_exception_veth_R1-B.pcap
6087 tcpdump -s 0 -i veth_B-R1 -w pmtu_ipv4_exception_veth_B-R1.pcap
6088 tcpdump -s 0 -i veth_A-R2 -w pmtu_ipv4_exception_veth_A-R2.pcap
6089 tcpdump -s 0 -i veth_R2-A -w pmtu_ipv4_exception_veth_R2-A.pcap
6090 tcpdump -s 0 -i veth_R2-B -w pmtu_ipv4_exception_veth_R2-B.pcap
6091 tcpdump -s 0 -i veth_B-R2 -w pmtu_ipv4_exception_veth_B-R2.pcap
6228 tcpdump -s 0 -i veth_A-R1 -w pmtu_ipv4_exception_veth_A-R1.pcap
6229 tcpdump -s 0 -i veth_R1-A -w pmtu_ipv4_exception_veth_R1-A.pcap
6230 tcpdump -s 0 -i veth_R1-B -w pmtu_ipv4_exception_veth_R1-B.pcap
6231 tcpdump -s 0 -i veth_B-R1 -w pmtu_ipv4_exception_veth_B-R1.pcap
6232 tcpdump -s 0 -i veth_A-R2 -w pmtu_ipv4_exception_veth_A-R2.pcap
6233 tcpdump -s 0 -i veth_R2-A -w pmtu_ipv4_exception_veth_R2-A.pcap
6234 tcpdump -s 0 -i veth_R2-B -w pmtu_ipv4_exception_veth_R2-B.pcap
6235 tcpdump -s 0 -i veth_B-R2 -w pmtu_ipv4_exception_veth_B-R2.pcap

Fix this by running cleanup() in the context of the test subshell.
Now that each test cleans the environment after completion, there's no
need for calling cleanup() again when the next test starts. So let's
drop it from the setup() function. This is okay because cleanup() is
also called when pmtu.sh starts, so even the first test starts in a
clean environment.

Also, use tcpdump's immediate mode. Otherwise it might not have time to
process buffered packets, resulting in missing packets or even empty
pcap files for short tests.

Note: PAUSE_ON_FAIL is still evaluated before cleanup(), so one can
still inspect the test environment upon failure when using -p.

Fixes: a92a0a7b8e7c ("selftests: pmtu: Simplify cleanup and namespace names")
Signed-off-by: Guillaume Nault 
Reviewed-by: Shuah Khan 
Signed-off-by: Jakub Kicinski

selftests: net: add ESP-in-UDP PMTU test

2021-07-21T15:50:35+00:00

The case of ESP in UDP encapsulation was not covered before. Add
cases of local changes of MTU and difference on routed path.

Signed-off-by: Vadim Fedorenko 
Signed-off-by: David S. Miller

tools: selftests: add test for changing routes with PTMU exceptions

2021-01-07T20:03:36+00:00

Adds new 2 new tests to the PTMU script: pmtu_ipv4/6_route_change.

These tests explicitly test for a recently discovered problem in the
IPv6 routing framework where PMTU exceptions were not properly released
when replacing a route via "ip route change ...".

After creating PMTU exceptions, the route from the device A to R1 will be
replaced with a new route, then device A will be deleted. If the PMTU
exceptions were properly cleaned up by the kernel, this device deletion
will succeed. Otherwise, the unregistration of the device will stall, and
messages such as the following will be logged in dmesg:

unregister_netdevice: waiting for veth_A-R1 to become free. Usage count = 4

Signed-off-by: Sean Tranchetti 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/1609892546-11389-2-git-send-email-stranche@quicinc.com
Signed-off-by: Jakub Kicinski

selftests: pmtu.sh: improve the test result processing

2020-11-12T15:56:30+00:00

This test will treat all non-zero return codes as failures, it will
make the pmtu.sh test script being marked as FAILED when some
sub-test got skipped.

Improve the result processing by
  * Only mark the whole test script as SKIP when all of the
    sub-tests were skipped
  * If the sub-tests were either passed or skipped, the overall
    result will be PASS
  * If any of them has failed with return code 1 or anything bad
    happened (e.g. return code 127 for command not found), the
    overall result will be FAIL

Signed-off-by: Po-Hsu Lin 
Signed-off-by: Jakub Kicinski

selftests: pmtu.sh: use $ksft_skip for skipped return code

2020-11-12T15:56:30+00:00

This test uses return code 2 as a hard-coded skipped state, let's use
the kselftest framework skip code variable $ksft_skip instead to make
it more readable and easier to maintain.

Signed-off-by: Po-Hsu Lin 
Signed-off-by: Jakub Kicinski

selftests: pmtu.sh: Add tests for UDP tunnels handled by Open vSwitch

2020-08-04T20:01:46+00:00

The new tests check that IP and IPv6 packets exceeding the local PMTU
estimate, forwarded by an Open vSwitch instance from another node,
result in the correct route exceptions being created, and that
communication with end-to-end fragmentation, over GENEVE and VXLAN
Open vSwitch ports, is now possible as a result of PMTU discovery.

Signed-off-by: Stefano Brivio 
Signed-off-by: David S. Miller

selftests: pmtu.sh: Add tests for bridged UDP tunnels

2020-08-04T20:01:45+00:00

The new tests check that IP and IPv6 packets exceeding the local PMTU
estimate, both locally generated and forwarded by a bridge from
another node, result in the correct route exceptions being created,
and that communication with end-to-end fragmentation over VXLAN and
GENEVE tunnels is now possible as a result of PMTU discovery.

Part of the existing setup functions aren't generic enough to simply
add a namespace and a bridge to the existing routing setup. This
rework is in progress and we can easily shrink this once more generic
topology functions are available.

Signed-off-by: Stefano Brivio 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller