1 files changed, 169 insertions, 0 deletions
diff --git a/samples/bpf/xdp_sample_pkts_user.c b/samples/bpf/xdp_sample_pkts_user.c
new file mode 100644
index 000000000000..8dd87c1eb560
--- /dev/null
+++ b/samples/bpf/xdp_sample_pkts_user.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <linux/perf_event.h>
+#include <linux/bpf.h>
+#include <net/if.h>
+#include <errno.h>
+#include <assert.h>
+#include <sys/sysinfo.h>
+#include <sys/ioctl.h>
+#include <signal.h>
+#include <libbpf.h>
+#include <bpf/bpf.h>
+
+#include "perf-sys.h"
+#include "trace_helpers.h"
+
+#define MAX_CPUS 128
+static int pmu_fds[MAX_CPUS], if_idx;
+static struct perf_event_mmap_page *headers[MAX_CPUS];
+static char *if_name;
+
+static int do_attach(int idx, int fd, const char *name)
+{
+	int err;
+
+	err = bpf_set_link_xdp_fd(idx, fd, 0);
+	if (err < 0)
+		printf("ERROR: failed to attach program to %s\n", name);
+
+	return err;
+}
+
+static int do_detach(int idx, const char *name)
+{
+	int err;
+
+	err = bpf_set_link_xdp_fd(idx, -1, 0);
+	if (err < 0)
+		printf("ERROR: failed to detach program from %s\n", name);
+
+	return err;
+}
+
+#define SAMPLE_SIZE 64
+
+static int print_bpf_output(void *data, int size)
+{
+	struct {
+		__u16 cookie;
+		__u16 pkt_len;
+		__u8  pkt_data[SAMPLE_SIZE];
+	} __packed *e = data;
+	int i;
+
+	if (e->cookie != 0xdead) {
+		printf("BUG cookie %x sized %d\n",
+		       e->cookie, size);
+		return LIBBPF_PERF_EVENT_ERROR;
+	}
+
+	printf("Pkt len: %-5d bytes. Ethernet hdr: ", e->pkt_len);
+	for (i = 0; i < 14 && i < e->pkt_len; i++)
+		printf("%02x ", e->pkt_data[i]);
+	printf("\n");
+
+	return LIBBPF_PERF_EVENT_CONT;
+}
+
+static void test_bpf_perf_event(int map_fd, int num)
+{
+	struct perf_event_attr attr = {
+		.sample_type = PERF_SAMPLE_RAW,
+		.type = PERF_TYPE_SOFTWARE,
+		.config = PERF_COUNT_SW_BPF_OUTPUT,
+		.wakeup_events = 1, /* get an fd notification for every event */
+	};
+	int i;
+
+	for (i = 0; i < num; i++) {
+		int key = i;
+
+		pmu_fds[i] = sys_perf_event_open(&attr, -1/*pid*/, i/*cpu*/,
+						 -1/*group_fd*/, 0);
+
+		assert(pmu_fds[i] >= 0);
+		assert(bpf_map_update_elem(map_fd, &key,
+					   &pmu_fds[i], BPF_ANY) == 0);
+		ioctl(pmu_fds[i], PERF_EVENT_IOC_ENABLE, 0);
+	}
+}
+
+static void sig_handler(int signo)
+{
+	do_detach(if_idx, if_name);
+	exit(0);
+}
+
+int main(int argc, char **argv)
+{
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type	= BPF_PROG_TYPE_XDP,
+	};
+	struct bpf_object *obj;
+	struct bpf_map *map;
+	int prog_fd, map_fd;
+	char filename[256];
+	int ret, err, i;
+	int numcpus;
+
+	if (argc < 2) {
+		printf("Usage: %s <ifname>\n", argv[0]);
+		return 1;
+	}
+
+	numcpus = get_nprocs();
+	if (numcpus > MAX_CPUS)
+		numcpus = MAX_CPUS;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	prog_load_attr.file = filename;
+
+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
+		return 1;
+
+	if (!prog_fd) {
+		printf("load_bpf_file: %s\n", strerror(errno));
+		return 1;
+	}
+
+	map = bpf_map__next(NULL, obj);
+	if (!map) {
+		printf("finding a map in obj file failed\n");
+		return 1;
+	}
+	map_fd = bpf_map__fd(map);
+
+	if_idx = if_nametoindex(argv[1]);
+	if (!if_idx)
+		if_idx = strtoul(argv[1], NULL, 0);
+
+	if (!if_idx) {
+		fprintf(stderr, "Invalid ifname\n");
+		return 1;
+	}
+	if_name = argv[1];
+	err = do_attach(if_idx, prog_fd, argv[1]);
+	if (err)
+		return err;
+
+	if (signal(SIGINT, sig_handler) ||
+	    signal(SIGHUP, sig_handler) ||
+	    signal(SIGTERM, sig_handler)) {
+		perror("signal");
+		return 1;
+	}
+
+	test_bpf_perf_event(map_fd, numcpus);
+
+	for (i = 0; i < numcpus; i++)
+		if (perf_event_mmap_header(pmu_fds[i], &headers[i]) < 0)
+			return 1;
+
+	ret = perf_event_poller_multi(pmu_fds, headers, numcpus,
+				      print_bpf_output);
+	kill(0, SIGINT);
+	return ret;
+}