isisd: IS-IS over tunnel (GRE, GENEVE)

[miegl]

This patch introduces a new BFP filter in isis_pfpacket.c, which in addition to IS-IS over LLC also permits IS-IS over Ethertype 0x00fe. This makes IS-IS work over tunnels such as GRE.

Tested IS-IS over Ethernet, IS-IS over GRE and IS-IS over GENEVE (GENEVE requires upstreaming a kernel patch).

Resolves #2330 (may need setting isis network point-to-point).

[vjardin]

Which kernel patch is needed for GENEVE case ? Please, share a URL.

[miegl]

These are the kernel patches in question:
https://patchwork.kernel.org/project/netdevbpf/patch/20230312163726.55257-1-josef@miegl.cz/
https://patchwork.kernel.org/project/netdevbpf/patch/20230312164557.55354-1-josef@miegl.cz/

With these two patches, a GENEVE tunnel created with innerprotoinherit (man 8 ip-link) can carry IS-IS traffic (byte 0x83) with Protocol Type 0x00fe, without the overhead of Ethernet. One usecase for this is a virtual MPLS/SR-MPLS network, as GENEVE can carry MPLS and IS-IS directly, without Ethernet.

[NetDEF-CI]

Continuous Integration Result: SUCCESSFUL

Congratulations, this patch passed basic tests

Tested-by: NetDEF / OpenSourceRouting.org CI System

CI System Testrun URL: https://ci1.netdef.org/browse/FRR-PULLREQ2-10121/

This is a comment from an automated CI system.
For questions and feedback in regards to this CI system, please feel free to email
Martin Winter - mwinter (at) opensourcerouting.org.

Warnings Generated during build:

Checkout code: Successful with additional warnings

Report for isis_pfpacket.c | 2 issues
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< WARNING: Block comments use a trailing */ on a separate line
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[riw777]

looks good

[clay584]

@riw777 Do you know when this will be pulled into a release?