[RFC PATCH bpf-next 9/9] selftests/bpf: fib_lookup: Add IPv6 link-local tests

[Ido Schimmel <idosch@nvidia.com>]

Add tests that verify that bpf_fib_lookup() is able to resolve the
destination MAC for an IPv6 link-local address when specifying the
BPF_FIB_LOOKUP_OUTPUT flag.

Output without "bpf: fib_lookup: Allow output lookups for IPv6
link-local addresses":

 # ./test_progs -a fib_lookup
 [...]
 Testing IPv6 output route, link-local, via first device set_lookup_params:PASS:inet_pton(IPV6_IFACE_ADDR) 0 nsec
 test_fib_lookup:PASS:bpf_prog_test_run_opts 0 nsec
 test_fib_lookup:FAIL:fib_lookup_ret unexpected fib_lookup_ret: actual 4 != expected 0
 [...]
 Testing IPv6 output route, link-local, via second device set_lookup_params:PASS:inet_pton(IPV6_IFACE_ADDR) 0 nsec
 test_fib_lookup:PASS:bpf_prog_test_run_opts 0 nsec
 test_fib_lookup:FAIL:fib_lookup_ret unexpected fib_lookup_ret: actual 4 != expected 0
 [...]
 #119     fib_lookup:FAIL
 Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED

Output with "bpf: fib_lookup: Allow output lookups for IPv6 link-local
addresses":

 # ./test_progs -a fib_lookup
 #119     fib_lookup:OK
 Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---
 .../testing/selftests/bpf/prog_tests/fib_lookup.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/fib_lookup.c b/tools/testing/selftests/bpf/prog_tests/fib_lookup.c
index 9e933daf56d7..3dca6fde249b 100644
--- a/tools/testing/selftests/bpf/prog_tests/fib_lookup.c
+++ b/tools/testing/selftests/bpf/prog_tests/fib_lookup.c
@@ -47,6 +47,8 @@
 #define IPV4_OUTPUT_DST		"192.0.2.1"
 #define IPV6_OUTPUT_NET		"2001:db8:1::"
 #define IPV6_OUTPUT_DST		"2001:db8:1::1"
+#define IPV6_LL_ADDR		"fe80::1"
+#define IPV6_LL_DST		"fe80::2"
 
 struct fib_lookup_test {
 	const char *desc;
@@ -207,6 +209,14 @@ static const struct fib_lookup_test tests[] = {
 	  .expected_ret = BPF_FIB_LKUP_RET_NOT_FWDED,
 	  .lookup_flags = BPF_FIB_LOOKUP_OUTPUT | BPF_FIB_LOOKUP_SKIP_NEIGH,
 	  .ifindex = IFINDEX_VETH2, },
+	{ .desc = "IPv6 output route, link-local, via first device",
+	  .daddr = IPV6_LL_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
+	  .lookup_flags = BPF_FIB_LOOKUP_OUTPUT, .dmac = DMAC_INIT,
+	  .ifindex = IFINDEX_VETH1, .expected_ifindex = IFINDEX_VETH1, },
+	{ .desc = "IPv6 output route, link-local, via second device",
+	  .daddr = IPV6_LL_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
+	  .lookup_flags = BPF_FIB_LOOKUP_OUTPUT, .dmac = DMAC_INIT2,
+	  .ifindex = IFINDEX_VETH2, .expected_ifindex = IFINDEX_VETH2, },
 };
 
 static int setup_netns(void)
@@ -289,6 +299,11 @@ static int setup_netns(void)
 	SYS(fail, "ip neigh add %s dev veth1 lladdr %s nud perm", IPV6_OUTPUT_DST, DMAC);
 	SYS(fail, "ip neigh add %s dev veth2 lladdr %s nud perm", IPV6_OUTPUT_DST, DMAC2);
 
+	SYS(fail, "ip addr add %s/64 dev veth1 nodad", IPV6_LL_ADDR);
+	SYS(fail, "ip addr add %s/64 dev veth2 nodad", IPV6_LL_ADDR);
+	SYS(fail, "ip neigh add %s dev veth1 lladdr %s nud perm", IPV6_LL_DST, DMAC);
+	SYS(fail, "ip neigh add %s dev veth2 lladdr %s nud perm", IPV6_LL_DST, DMAC2);
+
 	return 0;
 fail:
 	return -1;
-- 
2.53.0