[linux-2.6-block.git] / samples / bpf / xdp_sample_pkts_kern.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/ptrace.h>
#include <linux/version.h>
#include <uapi/linux/bpf.h>
#include "bpf_helpers.h"

#define SAMPLE_SIZE 64ul
#define MAX_CPUS 128

struct bpf_map_def SEC("maps") my_map = {
	.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
	.key_size = sizeof(int),
	.value_size = sizeof(u32),
	.max_entries = MAX_CPUS,
};

SEC("xdp_sample")
int xdp_sample_prog(struct xdp_md *ctx)
{
	void *data_end = (void *)(long)ctx->data_end;
	void *data = (void *)(long)ctx->data;

	/* Metadata will be in the perf event before the packet data. */
	struct S {
		u16 cookie;
		u16 pkt_len;
	} __packed metadata;

	if (data < data_end) {
		/* The XDP perf_event_output handler will use the upper 32 bits
		 * of the flags argument as a number of bytes to include of the
		 * packet payload in the event data. If the size is too big, the
		 * call to bpf_perf_event_output will fail and return -EFAULT.
		 *
		 * See bpf_xdp_event_output in net/core/filter.c.
		 *
		 * The BPF_F_CURRENT_CPU flag means that the event output fd
		 * will be indexed by the CPU number in the event map.
		 */
		u64 flags = BPF_F_CURRENT_CPU;
		u16 sample_size;
		int ret;

		metadata.cookie = 0xdead;
		metadata.pkt_len = (u16)(data_end - data);
		sample_size = min(metadata.pkt_len, SAMPLE_SIZE);
		flags |= (u64)sample_size << 32;

		ret = bpf_perf_event_output(ctx, &my_map, flags,
					    &metadata, sizeof(metadata));
		if (ret)
			bpf_printk("perf_event_output failed: %d\n", ret);
	}

	return XDP_PASS;
}

char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;
Commit	Line	Data
1e54ad25 THJ	1	// SPDX-License-Identifier: GPL-2.0
	2	#include <linux/ptrace.h>
	3	#include <linux/version.h>
	4	#include <uapi/linux/bpf.h>
	5	#include "bpf_helpers.h"
	6
	7	#define SAMPLE_SIZE 64ul
	8	#define MAX_CPUS 128
	9
1e54ad25 THJ	10	struct bpf_map_def SEC("maps") my_map = {
	11	.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
	12	.key_size = sizeof(int),
	13	.value_size = sizeof(u32),
	14	.max_entries = MAX_CPUS,
	15	};
	16
	17	SEC("xdp_sample")
	18	int xdp_sample_prog(struct xdp_md *ctx)
	19	{
	20	void data_end = (void )(long)ctx->data_end;
	21	void data = (void )(long)ctx->data;
	22
	23	/* Metadata will be in the perf event before the packet data. */
	24	struct S {
	25	u16 cookie;
	26	u16 pkt_len;
	27	} __packed metadata;
	28
	29	if (data < data_end) {
	30	/* The XDP perf_event_output handler will use the upper 32 bits
	31	* of the flags argument as a number of bytes to include of the
	32	* packet payload in the event data. If the size is too big, the
	33	* call to bpf_perf_event_output will fail and return -EFAULT.
	34	*
	35	* See bpf_xdp_event_output in net/core/filter.c.
	36	*
	37	* The BPF_F_CURRENT_CPU flag means that the event output fd
	38	* will be indexed by the CPU number in the event map.
	39	*/
	40	u64 flags = BPF_F_CURRENT_CPU;
	41	u16 sample_size;
	42	int ret;
	43
	44	metadata.cookie = 0xdead;
	45	metadata.pkt_len = (u16)(data_end - data);
	46	sample_size = min(metadata.pkt_len, SAMPLE_SIZE);
	47	flags \|= (u64)sample_size << 32;
	48
	49	ret = bpf_perf_event_output(ctx, &my_map, flags,
	50	&metadata, sizeof(metadata));
	51	if (ret)
	52	bpf_printk("perf_event_output failed: %d\n", ret);
	53	}
	54
	55	return XDP_PASS;
	56	}
	57
	58	char _license[] SEC("license") = "GPL";
	59	u32 _version SEC("version") = LINUX_VERSION_CODE;