selftests/bpf: Migrate wildcard destination rewrite test

Migrate test case from bpf/test_sock_addr.c ensuring that sendmsg
respects when sendmsg6 hooks rewrite the destination IP with the IPv6
wildcard IP, [::].

Signed-off-by: Jordan Rife <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>

1 files changed, 20 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/sendmsg6_prog.c b/tools/testing/selftests/bpf/progs/sendmsg6_prog.c
index 7611d9e17dd1..36a7f960799f 100644
--- a/tools/testing/selftests/bpf/progs/sendmsg6_prog.c
+++ b/tools/testing/selftests/bpf/progs/sendmsg6_prog.c
@@ -85,6 +85,26 @@ int sendmsg_v6_v4mapped_prog(struct bpf_sock_addr *ctx)
 }
 
 SEC("cgroup/sendmsg6")
+int sendmsg_v6_wildcard_prog(struct bpf_sock_addr *ctx)
+{
+	/* Rewrite source. */
+	ctx->msg_src_ip6[0] = bpf_htonl(SRC_REWRITE_IP6_0);
+	ctx->msg_src_ip6[1] = bpf_htonl(SRC_REWRITE_IP6_1);
+	ctx->msg_src_ip6[2] = bpf_htonl(SRC_REWRITE_IP6_2);
+	ctx->msg_src_ip6[3] = bpf_htonl(SRC_REWRITE_IP6_3);
+
+	/* Rewrite destination. */
+	ctx->user_ip6[0] = bpf_htonl(0);
+	ctx->user_ip6[1] = bpf_htonl(0);
+	ctx->user_ip6[2] = bpf_htonl(0);
+	ctx->user_ip6[3] = bpf_htonl(0);
+
+	ctx->user_port = bpf_htons(DST_REWRITE_PORT6);
+
+	return 1;
+}
+
+SEC("cgroup/sendmsg6")
 int sendmsg_v6_preserve_dst_prog(struct bpf_sock_addr *ctx)
 {
 	return 1;