1 files changed, 95 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/bind_perm.c b/tools/testing/selftests/bpf/prog_tests/bind_perm.c
new file mode 100644
index 000000000000..a1766a298bb7
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/bind_perm.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sched.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include "test_progs.h"
+#include "cap_helpers.h"
+#include "bind_perm.skel.h"
+
+static int duration;
+
+static int create_netns(void)
+{
+	if (!ASSERT_OK(unshare(CLONE_NEWNET), "create netns"))
+		return -1;
+
+	return 0;
+}
+
+void try_bind(int family, int port, int expected_errno)
+{
+	struct sockaddr_storage addr = {};
+	struct sockaddr_in6 *sin6;
+	struct sockaddr_in *sin;
+	int fd = -1;
+
+	fd = socket(family, SOCK_STREAM, 0);
+	if (CHECK(fd < 0, "fd", "errno %d", errno))
+		goto close_socket;
+
+	if (family == AF_INET) {
+		sin = (struct sockaddr_in *)&addr;
+		sin->sin_family = family;
+		sin->sin_port = htons(port);
+	} else {
+		sin6 = (struct sockaddr_in6 *)&addr;
+		sin6->sin6_family = family;
+		sin6->sin6_port = htons(port);
+	}
+
+	errno = 0;
+	bind(fd, (struct sockaddr *)&addr, sizeof(addr));
+	ASSERT_EQ(errno, expected_errno, "bind");
+
+close_socket:
+	if (fd >= 0)
+		close(fd);
+}
+
+void test_bind_perm(void)
+{
+	const __u64 net_bind_svc_cap = 1ULL << CAP_NET_BIND_SERVICE;
+	struct bind_perm *skel;
+	__u64 old_caps = 0;
+	int cgroup_fd;
+
+	if (create_netns())
+		return;
+
+	cgroup_fd = test__join_cgroup("/bind_perm");
+	if (CHECK(cgroup_fd < 0, "cg-join", "errno %d", errno))
+		return;
+
+	skel = bind_perm__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel"))
+		goto close_cgroup_fd;
+
+	skel->links.bind_v4_prog = bpf_program__attach_cgroup(skel->progs.bind_v4_prog, cgroup_fd);
+	if (!ASSERT_OK_PTR(skel, "bind_v4_prog"))
+		goto close_skeleton;
+
+	skel->links.bind_v6_prog = bpf_program__attach_cgroup(skel->progs.bind_v6_prog, cgroup_fd);
+	if (!ASSERT_OK_PTR(skel, "bind_v6_prog"))
+		goto close_skeleton;
+
+	ASSERT_OK(cap_disable_effective(net_bind_svc_cap, &old_caps),
+		  "cap_disable_effective");
+
+	try_bind(AF_INET, 110, EACCES);
+	try_bind(AF_INET6, 110, EACCES);
+
+	try_bind(AF_INET, 111, 0);
+	try_bind(AF_INET6, 111, 0);
+
+	if (old_caps & net_bind_svc_cap)
+		ASSERT_OK(cap_enable_effective(net_bind_svc_cap, NULL),
+			  "cap_enable_effective");
+
+close_skeleton:
+	bind_perm__destroy(skel);
+close_cgroup_fd:
+	close(cgroup_fd);
+}