1 files changed, 94 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/connect_force_port6.c b/tools/testing/selftests/bpf/progs/connect_force_port6.c
new file mode 100644
index 000000000000..c1a2b555e9ad
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/connect_force_port6.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <string.h>
+
+#include <linux/bpf.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <sys/socket.h>
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+char _license[] SEC("license") = "GPL";
+int _version SEC("version") = 1;
+
+struct svc_addr {
+	__be32 addr[4];
+	__be16 port;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_SK_STORAGE);
+	__uint(map_flags, BPF_F_NO_PREALLOC);
+	__type(key, int);
+	__type(value, struct svc_addr);
+} service_mapping SEC(".maps");
+
+SEC("cgroup/connect6")
+int connect6(struct bpf_sock_addr *ctx)
+{
+	struct sockaddr_in6 sa = {};
+	struct svc_addr *orig;
+
+	/* Force local address to [::1]:22223. */
+	sa.sin6_family = AF_INET6;
+	sa.sin6_port = bpf_htons(22223);
+	sa.sin6_addr.s6_addr32[3] = bpf_htonl(1);
+
+	if (bpf_bind(ctx, (struct sockaddr *)&sa, sizeof(sa)) != 0)
+		return 0;
+
+	/* Rewire service [fc00::1]:60000 to backend [::1]:60124. */
+	if (ctx->user_port == bpf_htons(60000)) {
+		orig = bpf_sk_storage_get(&service_mapping, ctx->sk, 0,
+					  BPF_SK_STORAGE_GET_F_CREATE);
+		if (!orig)
+			return 0;
+
+		orig->addr[0] = ctx->user_ip6[0];
+		orig->addr[1] = ctx->user_ip6[1];
+		orig->addr[2] = ctx->user_ip6[2];
+		orig->addr[3] = ctx->user_ip6[3];
+		orig->port = ctx->user_port;
+
+		ctx->user_ip6[0] = 0;
+		ctx->user_ip6[1] = 0;
+		ctx->user_ip6[2] = 0;
+		ctx->user_ip6[3] = bpf_htonl(1);
+		ctx->user_port = bpf_htons(60124);
+	}
+	return 1;
+}
+
+SEC("cgroup/getsockname6")
+int getsockname6(struct bpf_sock_addr *ctx)
+{
+	/* Expose local server as [fc00::1]:60000 to client. */
+	if (ctx->user_port == bpf_htons(60124)) {
+		ctx->user_ip6[0] = bpf_htonl(0xfc000000);
+		ctx->user_ip6[1] = 0;
+		ctx->user_ip6[2] = 0;
+		ctx->user_ip6[3] = bpf_htonl(1);
+		ctx->user_port = bpf_htons(60000);
+	}
+	return 1;
+}
+
+SEC("cgroup/getpeername6")
+int getpeername6(struct bpf_sock_addr *ctx)
+{
+	struct svc_addr *orig;
+
+	/* Expose service [fc00::1]:60000 as peer instead of backend. */
+	if (ctx->user_port == bpf_htons(60124)) {
+		orig = bpf_sk_storage_get(&service_mapping, ctx->sk, 0, 0);
+		if (orig) {
+			ctx->user_ip6[0] = orig->addr[0];
+			ctx->user_ip6[1] = orig->addr[1];
+			ctx->user_ip6[2] = orig->addr[2];
+			ctx->user_ip6[3] = orig->addr[3];
+			ctx->user_port = orig->port;
+		}
+	}
+	return 1;
+}