bpf: selftests: Support custom type and proto for client sockets

Extend connect_to_fd_opts() to take optional type and protocol
parameters for the client socket. These parameters are useful when
opening a raw socket to send IP fragments.
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/9067db539efdfd608aa86a2b143c521337c111fc.1689970773.git.dxu@dxuuu.xyzSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/network_helpers.c

@@ -270,14 +270,23 @@ int connect_to_fd_opts(int server_fd, const struct network_helper_opts *opts)
 		opts = &default_opts;
 
 	optlen = sizeof(type);
-	if (getsockopt(server_fd, SOL_SOCKET, SO_TYPE, &type, &optlen)) {
-		log_err("getsockopt(SOL_TYPE)");
-		return -1;
+
+	if (opts->type) {
+		type = opts->type;
+	} else {
+		if (getsockopt(server_fd, SOL_SOCKET, SO_TYPE, &type, &optlen)) {
+			log_err("getsockopt(SOL_TYPE)");
+			return -1;
+		}
 	}
 
-	if (getsockopt(server_fd, SOL_SOCKET, SO_PROTOCOL, &protocol, &optlen)) {
-		log_err("getsockopt(SOL_PROTOCOL)");
-		return -1;
+	if (opts->proto) {
+		protocol = opts->proto;
+	} else {
+		if (getsockopt(server_fd, SOL_SOCKET, SO_PROTOCOL, &protocol, &optlen)) {
+			log_err("getsockopt(SOL_PROTOCOL)");
+			return -1;
+		}
 	}
 
 	addrlen = sizeof(addr);

tools/testing/selftests/bpf/network_helpers.h

@@ -22,6 +22,8 @@ struct network_helper_opts {
 	int timeout_ms;
 	bool must_fail;
 	bool noconnect;
+	int type;
+	int proto;
 };
 
 /* ipv4 test vector */