selftests/net: Add TCP-AO library

Provide functions to create selftests dedicated to TCP-AO.
They can run in parallel, as they use temporary net namespaces.
They can be very specific to the feature being tested.
This will allow to create a lot of TCP-AO tests, without complicating
one binary with many --options and to create scenarios, that are
hard to put in bash script that uses one binary.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 148 insertions, 0 deletions

diff --git a/tools/testing/selftests/net/tcp_ao/lib/kconfig.c b/tools/testing/selftests/net/tcp_ao/lib/kconfig.c
new file mode 100644
index 000000000000..f279ffc3843b
--- /dev/null
+++ b/tools/testing/selftests/net/tcp_ao/lib/kconfig.c
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Check what features does the kernel support (where the selftest is running).
+ * Somewhat inspired by CRIU kerndat/kdat kernel features detector.
+ */
+#include <pthread.h>
+#include "aolib.h"
+
+struct kconfig_t {
+	int _errno;		/* the returned error if not supported */
+	int (*check_kconfig)(int *error);
+};
+
+static int has_net_ns(int *err)
+{
+	if (access("/proc/self/ns/net", F_OK) < 0) {
+		*err = errno;
+		if (errno == ENOENT)
+			return 0;
+		test_print("Unable to access /proc/self/ns/net: %m");
+		return -errno;
+	}
+	return *err = errno = 0;
+}
+
+static int has_veth(int *err)
+{
+	int orig_netns, ns_a, ns_b;
+
+	orig_netns = open_netns();
+	ns_a = unshare_open_netns();
+	ns_b = unshare_open_netns();
+
+	*err = add_veth("check_veth", ns_a, ns_b);
+
+	switch_ns(orig_netns);
+	close(orig_netns);
+	close(ns_a);
+	close(ns_b);
+	return 0;
+}
+
+static int has_tcp_ao(int *err)
+{
+	struct sockaddr_in addr = {
+		.sin_family = test_family,
+	};
+	struct tcp_ao_add tmp = {};
+	const char *password = DEFAULT_TEST_PASSWORD;
+	int sk, ret = 0;
+
+	sk = socket(test_family, SOCK_STREAM, IPPROTO_TCP);
+	if (sk < 0) {
+		test_print("socket(): %m");
+		return -errno;
+	}
+
+	tmp.sndid = 100;
+	tmp.rcvid = 100;
+	tmp.keylen = strlen(password);
+	memcpy(tmp.key, password, strlen(password));
+	strcpy(tmp.alg_name, "hmac(sha1)");
+	memcpy(&tmp.addr, &addr, sizeof(addr));
+	*err = 0;
+	if (setsockopt(sk, IPPROTO_TCP, TCP_AO_ADD_KEY, &tmp, sizeof(tmp)) < 0) {
+		*err = errno;
+		if (errno != ENOPROTOOPT)
+			ret = -errno;
+	}
+	close(sk);
+	return ret;
+}
+
+static int has_tcp_md5(int *err)
+{
+	union tcp_addr addr_any = {};
+	int sk, ret = 0;
+
+	sk = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+	if (sk < 0) {
+		test_print("socket(): %m");
+		return -errno;
+	}
+
+	/*
+	 * Under CONFIG_CRYPTO_FIPS=y it fails with ENOMEM, rather with
+	 * anything more descriptive. Oh well.
+	 */
+	*err = 0;
+	if (test_set_md5(sk, addr_any, 0, -1, DEFAULT_TEST_PASSWORD)) {
+		*err = errno;
+		if (errno != ENOPROTOOPT && errno == ENOMEM) {
+			test_print("setsockopt(TCP_MD5SIG_EXT): %m");
+			ret = -errno;
+		}
+	}
+	close(sk);
+	return ret;
+}
+
+static int has_vrfs(int *err)
+{
+	int orig_netns, ns_test, ret = 0;
+
+	orig_netns = open_netns();
+	ns_test = unshare_open_netns();
+
+	*err = add_vrf("ksft-check", 55, 101, ns_test);
+	if (*err && *err != -EOPNOTSUPP) {
+		test_print("Failed to add a VRF: %d", *err);
+		ret = *err;
+	}
+
+	switch_ns(orig_netns);
+	close(orig_netns);
+	close(ns_test);
+	return ret;
+}
+
+static pthread_mutex_t kconfig_lock = PTHREAD_MUTEX_INITIALIZER;
+static struct kconfig_t kconfig[__KCONFIG_LAST__] = {
+	{ -1, has_net_ns },
+	{ -1, has_veth },
+	{ -1, has_tcp_ao },
+	{ -1, has_tcp_md5 },
+	{ -1, has_vrfs },
+};
+
+const char *tests_skip_reason[__KCONFIG_LAST__] = {
+	"Tests require network namespaces support (CONFIG_NET_NS)",
+	"Tests require veth support (CONFIG_VETH)",
+	"Tests require TCP-AO support (CONFIG_TCP_AO)",
+	"setsockopt(TCP_MD5SIG_EXT) is not supported (CONFIG_TCP_MD5)",
+	"VRFs are not supported (CONFIG_NET_VRF)",
+};
+
+bool kernel_config_has(enum test_needs_kconfig k)
+{
+	bool ret;
+
+	pthread_mutex_lock(&kconfig_lock);
+	if (kconfig[k]._errno == -1) {
+		if (kconfig[k].check_kconfig(&kconfig[k]._errno))
+			test_error("Failed to initialize kconfig %u", k);
+	}
+	ret = kconfig[k]._errno == 0;
+	pthread_mutex_unlock(&kconfig_lock);
+	return ret;
+}