selftests: ioam: refactoring to align with the fix

ioam6_parser uses a packet socket. After the fix to prevent writing to
cloned skb's, the receiver does not see its IOAM data anymore, which
makes input/forward ioam-selftests to fail. As a workaround,
ioam6_parser now uses an IPv6 raw socket and leverages ancillary data to
get hop-by-hop options. As a consequence, the hook is "after" the IOAM
data insertion by the receiver and all tests are working again.

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

selftests/net: convert ioam6.sh to run it in unique namespace

Here is the test result after conversion.

]# ./ioam6.sh

--------------------------------------------------------------------------
OUTPUT tests
--------------------------------------------------------------------------
TEST: Unknown IOAM namespace (inline mode) [ OK ]
TEST: Unknown IOAM namespace (encap mode) [ OK ]
TEST: Missing trace room (inline mode) [ OK ]
TEST: Missing trace room (encap mode) [ OK ]
TEST: Trace type with bit 0 only (inline mode) [ OK ]
...
TEST: Full supported trace (encap mode) [ OK ]

--------------------------------------------------------------------------
GLOBAL tests
--------------------------------------------------------------------------
TEST: Forward - Full supported trace (inline mode) [ OK ]
TEST: Forward - Full supported trace (encap mode) [ OK ]

- Tests passed: 88
- Tests failed: 0

Acked-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

selftests: net: fix IOAM test skip return code

The ioam6.sh test script exits with an error code (1) when tests are
skipped due to lack of support from userspace/kernel or not enough
permissions. It should return the kselftests SKIP code instead.

Reviewed-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Link: https://lore.kernel.org/r/20220801124615.256416-1-kleber.souza@canonical.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

selftests: net: Test for the IOAM encapsulation with IPv6

This patch adds support for testing the encap (ip6ip6) mode of IOAM.

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests: net: modify IOAM tests for undef bits

The output behavior for undefined bits is now directly tested inside the bash
script. Trying to set an undefined bit should be refused.

The input behavior for undefined bits has been removed due to the fact that we
would need another sender allowed to set undefined bits.

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests: net: improved IOAM tests

As previously discussed with David Ahern, here is a refactored and improved
version of the IOAM self-test. It is now more complete and more robust. Now,
all tests are divided into three categories: OUTPUT (evaluates the IOAM
processing by the sender), INPUT (evaluates the IOAM processing by the receiver)
and GLOBAL (evaluates wider use cases that do not fall into the other two
categories). Both OUTPUT and INPUT tests only use a two-node topology (alpha and
beta), while GLOBAL tests use the entire three-node topology (alpha, beta,
gamma). Each test is documented inside its own handler in the (bash) script.

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests: net: Test for the IOAM insertion with IPv6

This test evaluates the IOAM insertion for IPv6 by checking the IOAM data
integrity on the receiver.

The topology is formed by 3 nodes: Alpha (sender), Beta (router in-between)
and Gamma (receiver). An IOAM domain is configured from Alpha to Gamma only,
which means not on the reverse path. When Gamma is the destination, Alpha
adds an IOAM option (Pre-allocated Trace) inside a Hop-by-hop and fills the
trace with its own IOAM data. Beta and Gamma also fill the trace. The IOAM
data integrity is checked on Gamma, by comparing with the pre-defined IOAM
configuration (see below).

+-------------------+ +-------------------+
| | | |
| alpha netns | | gamma netns |
| | | |
| +-------------+ | | +-------------+ |
| | veth0 | | | | veth0 | |
| | db01::2/64 | | | | db02::2/64 | |
| +-------------+ | | +-------------+ |
| . | | . |
+-------------------+ +-------------------+
. .
. .
. .
+----------------------------------------------------+
| . . |
| +-------------+ +-------------+ |
| | veth0 | | veth1 | |
| | db01::1/64 | ................ | db02::1/64 | |
| +-------------+ +-------------+ |
| |
| beta netns |
| |
+--------------------------+-------------------------+

~~~~~~~~~~~~~~~~~~~~~~
| IOAM configuration |
~~~~~~~~~~~~~~~~~~~~~~

Alpha
+-----------------------------------------------------------+
| Type | Value |
+-----------------------------------------------------------+
| Node ID | 1 |
+-----------------------------------------------------------+
| Node Wide ID | 11111111 |
+-----------------------------------------------------------+
| Ingress ID | 0xffff (default value) |
+-----------------------------------------------------------+
| Ingress Wide ID | 0xffffffff (default value) |
+-----------------------------------------------------------+
| Egress ID | 101 |
+-----------------------------------------------------------+
| Egress Wide ID | 101101 |
+-----------------------------------------------------------+
| Namespace Data | 0xdeadbee0 |
+-----------------------------------------------------------+
| Namespace Wide Data | 0xcafec0caf00dc0de |
+-----------------------------------------------------------+
| Schema ID | 777 |
+-----------------------------------------------------------+
| Schema Data | something that will be 4n-aligned |
+-----------------------------------------------------------+

Note: When Gamma is the destination, Alpha adds an IOAM Pre-allocated Trace
option inside a Hop-by-hop, where 164 bytes are pre-allocated for the
trace, with 123 as the IOAM-Namespace and with 0xfff00200 as the trace
type (= all available options at this time). As a result, and based on
IOAM configurations here, only both Alpha and Beta should be capable of
inserting their IOAM data while Gamma won't have enough space and will
set the overflow bit.

Beta
+-----------------------------------------------------------+
| Type | Value |
+-----------------------------------------------------------+
| Node ID | 2 |
+-----------------------------------------------------------+
| Node Wide ID | 22222222 |
+-----------------------------------------------------------+
| Ingress ID | 201 |
+-----------------------------------------------------------+
| Ingress Wide ID | 201201 |
+-----------------------------------------------------------+
| Egress ID | 202 |
+-----------------------------------------------------------+
| Egress Wide ID | 202202 |
+-----------------------------------------------------------+
| Namespace Data | 0xdeadbee1 |
+-----------------------------------------------------------+
| Namespace Wide Data | 0xcafec0caf11dc0de |
+-----------------------------------------------------------+
| Schema ID | 0xffffff (= None) |
+-----------------------------------------------------------+
| Schema Data | |
+-----------------------------------------------------------+

Gamma
+-----------------------------------------------------------+
| Type | Value |
+-----------------------------------------------------------+
| Node ID | 3 |
+-----------------------------------------------------------+
| Node Wide ID | 33333333 |
+-----------------------------------------------------------+
| Ingress ID | 301 |
+-----------------------------------------------------------+
| Ingress Wide ID | 301301 |
+-----------------------------------------------------------+
| Egress ID | 0xffff (default value) |
+-----------------------------------------------------------+
| Egress Wide ID | 0xffffffff (default value) |
+-----------------------------------------------------------+
| Namespace Data | 0xdeadbee2 |
+-----------------------------------------------------------+
| Namespace Wide Data | 0xcafec0caf22dc0de |
+-----------------------------------------------------------+
| Schema ID | 0xffffff (= None) |
+-----------------------------------------------------------+
| Schema Data | |
+-----------------------------------------------------------+

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: David S. Miller <davem@davemloft.net>