[RFC,net-next,v2,3/3] selftests/bpf: Add a test case for vsock sockmap

Add a test case testing the redirection from connectible AF_VSOCK
sockets to connectible AF_UNIX sockets.

Signed-off-by: Bobby Eshleman <bobby.eshleman@bytedance.com>
---
 .../selftests/bpf/prog_tests/sockmap_listen.c      | 163 +++++++++++++++++++++
 1 file changed, 163 insertions(+)

On Mon, Jan 30, 2023 at 08:35:14PM -0800, Bobby Eshleman wrote:
>Add a test case testing the redirection from connectible AF_VSOCK
>sockets to connectible AF_UNIX sockets.
>
>Signed-off-by: Bobby Eshleman <bobby.eshleman@bytedance.com>
>---
> .../selftests/bpf/prog_tests/sockmap_listen.c      | 163 +++++++++++++++++++++
> 1 file changed, 163 insertions(+)

For the vsock part:

Acked-by: Stefano Garzarella <sgarzare@redhat.com>

>
>diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_listen.c b/tools/testing/selftests/bpf/prog_tests/sockmap_listen.c
>index 2cf0c7a3fe23..8b5a2e09c9ed 100644
>--- a/tools/testing/selftests/bpf/prog_tests/sockmap_listen.c
>+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_listen.c
>@@ -18,6 +18,7 @@
> #include <string.h>
> #include <sys/select.h>
> #include <unistd.h>
>+#include <linux/vm_sockets.h>
>
> #include <bpf/bpf.h>
> #include <bpf/libbpf.h>
>@@ -249,6 +250,16 @@ static void init_addr_loopback6(struct sockaddr_storage *ss, socklen_t *len)
> 	*len = sizeof(*addr6);
> }
>
>+static void init_addr_loopback_vsock(struct sockaddr_storage *ss, socklen_t *len)
>+{
>+	struct sockaddr_vm *addr = memset(ss, 0, sizeof(*ss));
>+
>+	addr->svm_family = AF_VSOCK;
>+	addr->svm_port = VMADDR_PORT_ANY;
>+	addr->svm_cid = VMADDR_CID_LOCAL;
>+	*len = sizeof(*addr);
>+}
>+
> static void init_addr_loopback(int family, struct sockaddr_storage *ss,
> 			       socklen_t *len)
> {
>@@ -259,6 +270,9 @@ static void init_addr_loopback(int family, struct sockaddr_storage *ss,
> 	case AF_INET6:
> 		init_addr_loopback6(ss, len);
> 		return;
>+	case AF_VSOCK:
>+		init_addr_loopback_vsock(ss, len);
>+		return;
> 	default:
> 		FAIL("unsupported address family %d", family);
> 	}
>@@ -1434,6 +1448,8 @@ static const char *family_str(sa_family_t family)
> 		return "IPv6";
> 	case AF_UNIX:
> 		return "Unix";
>+	case AF_VSOCK:
>+		return "VSOCK";
> 	default:
> 		return "unknown";
> 	}
>@@ -1644,6 +1660,151 @@ static void test_unix_redir(struct test_sockmap_listen *skel, struct bpf_map *ma
> 	unix_skb_redir_to_connected(skel, map, sotype);
> }
>
>+/* Returns two connected loopback vsock sockets */
>+static int vsock_socketpair_connectible(int sotype, int *v0, int *v1)
>+{
>+	struct sockaddr_storage addr;
>+	socklen_t len = sizeof(addr);
>+	int s, p, c;
>+
>+	s = socket_loopback(AF_VSOCK, sotype);
>+	if (s < 0)
>+		return -1;
>+
>+	c = xsocket(AF_VSOCK, sotype | SOCK_NONBLOCK, 0);
>+	if (c == -1)
>+		goto close_srv;
>+
>+	if (getsockname(s, sockaddr(&addr), &len) < 0)
>+		goto close_cli;
>+
>+	if (connect(c, sockaddr(&addr), len) < 0 && errno != EINPROGRESS) {
>+		FAIL_ERRNO("connect");
>+		goto close_cli;
>+	}
>+
>+	len = sizeof(addr);
>+	p = accept_timeout(s, sockaddr(&addr), &len, IO_TIMEOUT_SEC);
>+	if (p < 0)
>+		goto close_cli;
>+
>+	*v0 = p;
>+	*v1 = c;
>+
>+	return 0;
>+
>+close_cli:
>+	close(c);
>+close_srv:
>+	close(s);
>+
>+	return -1;
>+}
>+
>+static void vsock_unix_redir_connectible(int sock_mapfd, int verd_mapfd,
>+					 enum redir_mode mode, int sotype)
>+{
>+	const char *log_prefix = redir_mode_str(mode);
>+	char a = 'a', b = 'b';
>+	int u0, u1, v0, v1;
>+	int sfd[2];
>+	unsigned int pass;
>+	int err, n;
>+	u32 key;
>+
>+	zero_verdict_count(verd_mapfd);
>+
>+	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0, sfd))
>+		return;
>+
>+	u0 = sfd[0];
>+	u1 = sfd[1];
>+
>+	err = vsock_socketpair_connectible(sotype, &v0, &v1);
>+	if (err) {
>+		FAIL("vsock_socketpair_connectible() failed");
>+		goto close_uds;
>+	}
>+
>+	err = add_to_sockmap(sock_mapfd, u0, v0);
>+	if (err) {
>+		FAIL("add_to_sockmap failed");
>+		goto close_vsock;
>+	}
>+
>+	n = write(v1, &a, sizeof(a));
>+	if (n < 0)
>+		FAIL_ERRNO("%s: write", log_prefix);
>+	if (n == 0)
>+		FAIL("%s: incomplete write", log_prefix);
>+	if (n < 1)
>+		goto out;
>+
>+	n = recv(mode == REDIR_INGRESS ? u0 : u1, &b, sizeof(b), MSG_DONTWAIT);
>+	if (n < 0)
>+		FAIL("%s: recv() err, errno=%d", log_prefix, errno);
>+	if (n == 0)
>+		FAIL("%s: incomplete recv", log_prefix);
>+	if (b != a)
>+		FAIL("%s: vsock socket map failed, %c != %c", log_prefix, a, b);
>+
>+	key = SK_PASS;
>+	err = xbpf_map_lookup_elem(verd_mapfd, &key, &pass);
>+	if (err)
>+		goto out;
>+	if (pass != 1)
>+		FAIL("%s: want pass count 1, have %d", log_prefix, pass);
>+out:
>+	key = 0;
>+	bpf_map_delete_elem(sock_mapfd, &key);
>+	key = 1;
>+	bpf_map_delete_elem(sock_mapfd, &key);
>+
>+close_vsock:
>+	close(v0);
>+	close(v1);
>+
>+close_uds:
>+	close(u0);
>+	close(u1);
>+}
>+
>+static void vsock_unix_skb_redir_connectible(struct test_sockmap_listen *skel,
>+					     struct bpf_map *inner_map,
>+					     int sotype)
>+{
>+	int verdict = bpf_program__fd(skel->progs.prog_skb_verdict);
>+	int verdict_map = bpf_map__fd(skel->maps.verdict_map);
>+	int sock_map = bpf_map__fd(inner_map);
>+	int err;
>+
>+	err = xbpf_prog_attach(verdict, sock_map, BPF_SK_SKB_VERDICT, 0);
>+	if (err)
>+		return;
>+
>+	skel->bss->test_ingress = false;
>+	vsock_unix_redir_connectible(sock_map, verdict_map, REDIR_EGRESS, sotype);
>+	skel->bss->test_ingress = true;
>+	vsock_unix_redir_connectible(sock_map, verdict_map, REDIR_INGRESS, sotype);
>+
>+	xbpf_prog_detach2(verdict, sock_map, BPF_SK_SKB_VERDICT);
>+}
>+
>+static void test_vsock_redir(struct test_sockmap_listen *skel, struct bpf_map *map)
>+{
>+	const char *family_name, *map_name;
>+	char s[MAX_TEST_NAME];
>+
>+	family_name = family_str(AF_VSOCK);
>+	map_name = map_type_str(map);
>+	snprintf(s, sizeof(s), "%s %s %s", map_name, family_name, __func__);
>+	if (!test__start_subtest(s))
>+		return;
>+
>+	vsock_unix_skb_redir_connectible(skel, map, SOCK_STREAM);
>+	vsock_unix_skb_redir_connectible(skel, map, SOCK_SEQPACKET);
>+}
>+
> static void test_reuseport(struct test_sockmap_listen *skel,
> 			   struct bpf_map *map, int family, int sotype)
> {
>@@ -2015,12 +2176,14 @@ void serial_test_sockmap_listen(void)
> 	run_tests(skel, skel->maps.sock_map, AF_INET6);
> 	test_unix_redir(skel, skel->maps.sock_map, SOCK_DGRAM);
> 	test_unix_redir(skel, skel->maps.sock_map, SOCK_STREAM);
>+	test_vsock_redir(skel, skel->maps.sock_map);
>
> 	skel->bss->test_sockmap = false;
> 	run_tests(skel, skel->maps.sock_hash, AF_INET);
> 	run_tests(skel, skel->maps.sock_hash, AF_INET6);
> 	test_unix_redir(skel, skel->maps.sock_hash, SOCK_DGRAM);
> 	test_unix_redir(skel, skel->maps.sock_hash, SOCK_STREAM);
>+	test_vsock_redir(skel, skel->maps.sock_hash);
>
> 	test_sockmap_listen__destroy(skel);
> }
>
>-- 
>2.35.1
>