linux/tools/testing
Andrea Mayer 32dfd742f0 selftests: seg6: add test for dst_cache isolation in seg6 lwtunnel
Add a selftest that verifies the dst_cache in seg6 lwtunnel is not
shared between the input (forwarding) and output (locally generated)
paths.

The test creates three namespaces (ns_src, ns_router, ns_dst)
connected in a line. An SRv6 encap route on ns_router encapsulates
traffic destined to cafe::1 with SID fc00::100. The SID is
reachable only for forwarded traffic (from ns_src) via an ip rule
matching the ingress interface (iif veth-r0 lookup 100), and
blackholed in the main table.

The test verifies that:

  1. A packet generated locally on ns_router does not reach
     ns_dst with an empty cache, since the SID is blackholed;
  2. A forwarded packet from ns_src populates the input cache
     from table 100 and reaches ns_dst;
  3. A packet generated locally on ns_router still does not
     reach ns_dst after the input cache is populated,
     confirming the output path does not reuse the input
     cache entry.

Both the forwarded and local packets are pinned to the same CPU
with taskset, since dst_cache is per-cpu.

Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Justin Iurman <justin.iurman@gmail.com>
Link: https://patch.msgid.link/20260404004405.4057-3-andrea.mayer@uniroma2.it
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-07 20:20:56 -07:00
..
crypto/chacha20-s390
cxl cxl changes for v7.0 2026-02-12 16:33:05 -08:00
fault-injection
ktest ktest.pl: Fix uninitialized var in config-bisect.pl 2025-12-03 18:25:18 -05:00
kunit kunit: tool: copy caller args in run_kernel to prevent mutation 2026-03-02 10:02:06 -07:00
memblock memblock: drop redundant 'struct page *' argument from memblock_free_pages() 2026-01-09 11:53:51 +02:00
nvdimm tools/testing/nvdimm: Use per-DIMM device handle 2025-11-03 16:47:13 -06:00
radix-tree idr: fix idr_alloc() returning an ID out of range 2025-12-23 11:23:11 -08:00
rbtree
scatterlist mm: remove nth_page() 2025-09-21 14:22:10 -07:00
selftests selftests: seg6: add test for dst_cache isolation in seg6 lwtunnel 2026-04-07 20:20:56 -07:00
shared tools: Update context analysis macros in compiler_types.h 2026-01-28 09:25:45 +01:00
vma tools/testing/vma: add VMA userland tests for VMA flag functions 2026-02-12 15:42:59 -08:00
vsock vsock/test: fix send_buf()/recv_buf() EINTR handling 2026-04-06 18:46:03 -07:00