selftests: ncdevmem: Use YNL to enable TCP header split

In the next patch the hard-coded queue numbers are gonna be removed.
So introduce some initial support for ethtool YNL and use
it to enable header split.

Also, tcp-data-split requires latest ethtool which is unlikely
to be present in the distros right now.

(ideally, we should not shell out to ethtool at all).

Reviewed-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20241107181211.3934153-9-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 56 insertions, 3 deletions

diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index 8c4db5199a42..61cce028f105 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -112,7 +112,7 @@ TEST_INCLUDES := forwarding/lib.sh
 include ../lib.mk
 
 # YNL build
-YNL_GENS := netdev
+YNL_GENS := ethtool netdev
 include ynl.mk
 
 $(OUTPUT)/epoll_busy_poll: LDLIBS += -lcap
diff --git a/tools/testing/selftests/net/ncdevmem.c b/tools/testing/selftests/net/ncdevmem.c
index ad6de8e0e97b..9ca2da3a2f63 100644
--- a/tools/testing/selftests/net/ncdevmem.c
+++ b/tools/testing/selftests/net/ncdevmem.c
@@ -55,10 +55,12 @@
 #include <linux/netlink.h>
 #include <linux/genetlink.h>
 #include <linux/netdev.h>
+#include <linux/ethtool_netlink.h>
 #include <time.h>
 #include <net/if.h>
 
 #include "netdev-user.h"
+#include "ethtool-user.h"
 #include <ynl.h>
 
 #define PAGE_SHIFT 12
@@ -231,10 +233,58 @@ static int reset_flow_steering(void)
 	return 0;
 }
 
+static const char *tcp_data_split_str(int val)
+{
+	switch (val) {
+	case 0:
+		return "off";
+	case 1:
+		return "auto";
+	case 2:
+		return "on";
+	default:
+		return "?";
+	}
+}
+
 static int configure_headersplit(bool on)
 {
-	return run_command("sudo ethtool -G %s tcp-data-split %s >&2", ifname,
-			   on ? "on" : "off");
+	struct ethtool_rings_get_req *get_req;
+	struct ethtool_rings_get_rsp *get_rsp;
+	struct ethtool_rings_set_req *req;
+	struct ynl_error yerr;
+	struct ynl_sock *ys;
+	int ret;
+
+	ys = ynl_sock_create(&ynl_ethtool_family, &yerr);
+	if (!ys) {
+		fprintf(stderr, "YNL: %s\n", yerr.msg);
+		return -1;
+	}
+
+	req = ethtool_rings_set_req_alloc();
+	ethtool_rings_set_req_set_header_dev_index(req, ifindex);
+	/* 0 - off, 1 - auto, 2 - on */
+	ethtool_rings_set_req_set_tcp_data_split(req, on ? 2 : 0);
+	ret = ethtool_rings_set(ys, req);
+	if (ret < 0)
+		fprintf(stderr, "YNL failed: %s\n", ys->err.msg);
+	ethtool_rings_set_req_free(req);
+
+	if (ret == 0) {
+		get_req = ethtool_rings_get_req_alloc();
+		ethtool_rings_get_req_set_header_dev_index(get_req, ifindex);
+		get_rsp = ethtool_rings_get(ys, get_req);
+		ethtool_rings_get_req_free(get_req);
+		if (get_rsp)
+			fprintf(stderr, "TCP header split: %s\n",
+				tcp_data_split_str(get_rsp->tcp_data_split));
+		ethtool_rings_get_rsp_free(get_rsp);
+	}
+
+	ynl_sock_destroy(ys);
+
+	return ret;
 }
 
 static int configure_rss(void)
@@ -382,6 +432,9 @@ int do_server(struct memory_buffer *mem)
 	if (reset_flow_steering())
 		error(1, 0, "Failed to reset flow steering\n");
 
+	if (configure_headersplit(1))
+		error(1, 0, "Failed to enable TCP header split\n");
+
 	/* Configure RSS to divert all traffic from our devmem queues */
 	if (configure_rss())
 		error(1, 0, "Failed to configure rss\n");