[PATCH bpf-next 3/6] selftests/xsk: implement get_hw_ring_size function to retrieve current and max interface size

[Tushar Vyavahare <tushar.vyavahare@xxxxxxxxx>]

Introduce a new function called get_hw_size that retrieves both the
current and maximum size of the interface and stores this information in
the 'hw_ring' structure.

Signed-off-by: Tushar Vyavahare <tushar.vyavahare@xxxxxxxxx>
---
 tools/testing/selftests/bpf/xskxceiver.c | 32 ++++++++++++++++++++++++
 tools/testing/selftests/bpf/xskxceiver.h |  8 ++++++
 2 files changed, 40 insertions(+)

diff --git a/tools/testing/selftests/bpf/xskxceiver.c b/tools/testing/selftests/bpf/xskxceiver.c
index eaa102c8098b..32005bfb9c9f 100644
--- a/tools/testing/selftests/bpf/xskxceiver.c
+++ b/tools/testing/selftests/bpf/xskxceiver.c
@@ -81,6 +81,8 @@
 #include <linux/mman.h>
 #include <linux/netdev.h>
 #include <linux/bitmap.h>
+#include <linux/sockios.h>
+#include <linux/ethtool.h>
 #include <arpa/inet.h>
 #include <net/if.h>
 #include <locale.h>
@@ -95,6 +97,7 @@
 #include <sys/socket.h>
 #include <sys/time.h>
 #include <sys/types.h>
+#include <sys/ioctl.h>
 #include <unistd.h>
 
 #include "xsk_xdp_progs.skel.h"
@@ -409,6 +412,35 @@ static void parse_command_line(struct ifobject *ifobj_tx, struct ifobject *ifobj
 	}
 }
 
+static int get_hw_ring_size(struct ifobject *ifobj)
+{
+	struct ethtool_ringparam ring_param = {0};
+	struct ifreq ifr = {0};
+	int sockfd;
+
+	sockfd = socket(AF_INET, SOCK_DGRAM, 0);
+	if (sockfd < 0)
+		return errno;
+
+	memcpy(ifr.ifr_name, ifobj->ifname, sizeof(ifr.ifr_name));
+
+	ring_param.cmd = ETHTOOL_GRINGPARAM;
+	ifr.ifr_data = (char *)&ring_param;
+
+	if (ioctl(sockfd, SIOCETHTOOL, &ifr) < 0) {
+		close(sockfd);
+		return errno;
+	}
+
+	ifobj->ring.default_tx = ring_param.tx_pending;
+	ifobj->ring.default_rx = ring_param.rx_pending;
+	ifobj->ring.max_tx = ring_param.tx_max_pending;
+	ifobj->ring.max_rx = ring_param.rx_max_pending;
+
+	close(sockfd);
+	return 0;
+}
+
 static void __test_spec_init(struct test_spec *test, struct ifobject *ifobj_tx,
 			     struct ifobject *ifobj_rx)
 {
diff --git a/tools/testing/selftests/bpf/xskxceiver.h b/tools/testing/selftests/bpf/xskxceiver.h
index 425304e52f35..4f58b70fa781 100644
--- a/tools/testing/selftests/bpf/xskxceiver.h
+++ b/tools/testing/selftests/bpf/xskxceiver.h
@@ -114,6 +114,13 @@ struct pkt_stream {
 	bool verbatim;
 };
 
+struct hw_ring {
+	u32 default_tx;
+	u32 default_rx;
+	u32 max_tx;
+	u32 max_rx;
+};
+
 struct ifobject;
 struct test_spec;
 typedef int (*validation_func_t)(struct ifobject *ifobj);
@@ -130,6 +137,7 @@ struct ifobject {
 	struct xsk_xdp_progs *xdp_progs;
 	struct bpf_map *xskmap;
 	struct bpf_program *xdp_prog;
+	struct hw_ring ring;
 	enum test_mode mode;
 	int ifindex;
 	int mtu;
-- 
2.34.1