bpftool: Refactor xdp attach/detach type judgment

This commit no logical changed, just increases code readability and
facilitates TCX prog expansion, which will be implemented in the next
patch.
Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240721143353.95980-2-chen.dylane@gmail.comSigned-off-by: Andrii Nakryiko <andrii@kernel.org>

tools/bpf/bpftool/net.c

@@ -684,10 +684,18 @@ static int do_attach(int argc, char **argv)
 		}
 	}
 
+	switch (attach_type) {
 	/* attach xdp prog */
-	if (is_prefix("xdp", attach_type_strings[attach_type]))
-		err = do_attach_detach_xdp(progfd, attach_type, ifindex,
-					   overwrite);
+	case NET_ATTACH_TYPE_XDP:
+	case NET_ATTACH_TYPE_XDP_GENERIC:
+	case NET_ATTACH_TYPE_XDP_DRIVER:
+	case NET_ATTACH_TYPE_XDP_OFFLOAD:
+		err = do_attach_detach_xdp(progfd, attach_type, ifindex, overwrite);
+		break;
+	default:
+		break;
+	}
+
 	if (err) {
 		p_err("interface %s attach failed: %s",
 		      attach_type_strings[attach_type], strerror(-err));
@@ -721,10 +729,18 @@ static int do_detach(int argc, char **argv)
 	if (ifindex < 1)
 		return -EINVAL;
 
+	switch (attach_type) {
 	/* detach xdp prog */
-	progfd = -1;
-	if (is_prefix("xdp", attach_type_strings[attach_type]))
+	case NET_ATTACH_TYPE_XDP:
+	case NET_ATTACH_TYPE_XDP_GENERIC:
+	case NET_ATTACH_TYPE_XDP_DRIVER:
+	case NET_ATTACH_TYPE_XDP_OFFLOAD:
+		progfd = -1;
 		err = do_attach_detach_xdp(progfd, attach_type, ifindex, NULL);
+		break;
+	default:
+		break;
+	}
 
 	if (err < 0) {
 		p_err("interface %s detach failed: %s",