1 files changed, 131 insertions, 0 deletions
diff --git a/tools/testing/selftests/net/lib/xdp_helper.c b/tools/testing/selftests/net/lib/xdp_helper.c
new file mode 100644
index 000000000000..eb025a9f35b1
--- /dev/null
+++ b/tools/testing/selftests/net/lib/xdp_helper.c
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/socket.h>
+#include <linux/if_xdp.h>
+#include <linux/if_link.h>
+#include <net/if.h>
+#include <inttypes.h>
+
+#include "ksft.h"
+
+#define UMEM_SZ (1U << 16)
+#define NUM_DESC (UMEM_SZ / 2048)
+
+
+static void print_usage(const char *bin)
+{
+	fprintf(stderr, "Usage: %s ifindex queue_id [-z]\n\n"
+		"where:\n\t-z: force zerocopy mode", bin);
+}
+
+/* this is a simple helper program that creates an XDP socket and does the
+ * minimum necessary to get bind() to succeed.
+ *
+ * this test program is not intended to actually process packets, but could be
+ * extended in the future if that is actually needed.
+ *
+ * it is used by queues.py to ensure the xsk netlinux attribute is set
+ * correctly.
+ */
+int main(int argc, char **argv)
+{
+	struct xdp_umem_reg umem_reg = { 0 };
+	struct sockaddr_xdp sxdp = { 0 };
+	int num_desc = NUM_DESC;
+	void *umem_area;
+	int retry = 0;
+	int ifindex;
+	int sock_fd;
+	int queue;
+
+	if (argc != 3 && argc != 4) {
+		print_usage(argv[0]);
+		return 1;
+	}
+
+	sock_fd = socket(AF_XDP, SOCK_RAW, 0);
+	if (sock_fd < 0) {
+		perror("socket creation failed");
+		/* if the kernel doesn't support AF_XDP, let the test program
+		 * know with -1. All other error paths return 1.
+		 */
+		if (errno == EAFNOSUPPORT)
+			return -1;
+		return 1;
+	}
+
+	/* "Probing mode", just checking if AF_XDP sockets are supported */
+	if (!strcmp(argv[1], "-") && !strcmp(argv[2], "-")) {
+		printf("AF_XDP support detected\n");
+		close(sock_fd);
+		return 0;
+	}
+
+	ifindex = atoi(argv[1]);
+	queue = atoi(argv[2]);
+
+	umem_area = mmap(NULL, UMEM_SZ, PROT_READ | PROT_WRITE, MAP_PRIVATE |
+			MAP_ANONYMOUS, -1, 0);
+	if (umem_area == MAP_FAILED) {
+		perror("mmap failed");
+		return 1;
+	}
+
+	umem_reg.addr = (uintptr_t)umem_area;
+	umem_reg.len = UMEM_SZ;
+	umem_reg.chunk_size = 2048;
+	umem_reg.headroom = 0;
+
+	setsockopt(sock_fd, SOL_XDP, XDP_UMEM_REG, &umem_reg,
+		   sizeof(umem_reg));
+	setsockopt(sock_fd, SOL_XDP, XDP_UMEM_FILL_RING, &num_desc,
+		   sizeof(num_desc));
+	setsockopt(sock_fd, SOL_XDP, XDP_UMEM_COMPLETION_RING, &num_desc,
+		   sizeof(num_desc));
+	setsockopt(sock_fd, SOL_XDP, XDP_RX_RING, &num_desc, sizeof(num_desc));
+
+	sxdp.sxdp_family = AF_XDP;
+	sxdp.sxdp_ifindex = ifindex;
+	sxdp.sxdp_queue_id = queue;
+	sxdp.sxdp_flags = 0;
+
+	if (argc > 3) {
+		if (!strcmp(argv[3], "-z")) {
+			sxdp.sxdp_flags = XDP_ZEROCOPY;
+		} else {
+			print_usage(argv[0]);
+			return 1;
+		}
+	}
+
+	while (1) {
+		if (bind(sock_fd, (struct sockaddr *)&sxdp, sizeof(sxdp)) == 0)
+			break;
+
+		if (errno == EBUSY && retry < 3) {
+			retry++;
+			sleep(1);
+			continue;
+		} else {
+			perror("bind failed");
+			munmap(umem_area, UMEM_SZ);
+			close(sock_fd);
+			return 1;
+		}
+	}
+
+	ksft_ready();
+	ksft_wait();
+
+	/* parent program will write a byte to stdin when its ready for this
+	 * helper to exit
+	 */
+
+	close(sock_fd);
+	return 0;
+}