[mirror_ubuntu-jammy-kernel.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/bpf_helpers.h>

#define SAMPLE_SIZE 64ul

struct {
	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
	__uint(key_size, sizeof(int));
	__uint(value_size, sizeof(u32));
} my_map SEC(".maps");

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>
7cf245a3	5	#include <bpf/bpf_helpers.h>
1e54ad25 THJ	6
1e54ad25 THJ	7	#define SAMPLE_SIZE 64ul
1e54ad25	8
321f6324 DL	9	struct {
	10	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
	11	__uint(key_size, sizeof(int));
	12	__uint(value_size, sizeof(u32));
	13	} my_map SEC(".maps");
1e54ad25 THJ	14
	15	SEC("xdp_sample")
	16	int xdp_sample_prog(struct xdp_md *ctx)
	17	{
	18	void data_end = (void )(long)ctx->data_end;
	19	void data = (void )(long)ctx->data;
	20
	21	/* Metadata will be in the perf event before the packet data. */
	22	struct S {
	23	u16 cookie;
	24	u16 pkt_len;
	25	} __packed metadata;
	26
	27	if (data < data_end) {
	28	/* The XDP perf_event_output handler will use the upper 32 bits
	29	* of the flags argument as a number of bytes to include of the
	30	* packet payload in the event data. If the size is too big, the
	31	* call to bpf_perf_event_output will fail and return -EFAULT.
	32	*
	33	* See bpf_xdp_event_output in net/core/filter.c.
	34	*
	35	* The BPF_F_CURRENT_CPU flag means that the event output fd
	36	* will be indexed by the CPU number in the event map.
	37	*/
	38	u64 flags = BPF_F_CURRENT_CPU;
	39	u16 sample_size;
	40	int ret;
	41
	42	metadata.cookie = 0xdead;
	43	metadata.pkt_len = (u16)(data_end - data);
	44	sample_size = min(metadata.pkt_len, SAMPLE_SIZE);
	45	flags \|= (u64)sample_size << 32;
	46
	47	ret = bpf_perf_event_output(ctx, &my_map, flags,
	48	&metadata, sizeof(metadata));
	49	if (ret)
	50	bpf_printk("perf_event_output failed: %d\n", ret);
	51	}
	52
	53	return XDP_PASS;
	54	}
	55
	56	char _license[] SEC("license") = "GPL";
	57	u32 _version SEC("version") = LINUX_VERSION_CODE;