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

/* SPDX-License-Identifier: GPL-2.0
 * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
 *
 *  Example howto extract XDP RX-queue info
 */
#include <uapi/linux/bpf.h>
#include <uapi/linux/if_ether.h>
#include <uapi/linux/in.h>
#include "bpf_helpers.h"

/* Config setup from with userspace
 *
 * User-side setup ifindex in config_map, to verify that
 * ctx->ingress_ifindex is correct (against configured ifindex)
 */
struct config {
	__u32 action;
	int ifindex;
	__u32 options;
};
enum cfg_options_flags {
	NO_TOUCH = 0x0U,
	READ_MEM = 0x1U,
	SWAP_MAC = 0x2U,
};
struct bpf_map_def SEC("maps") config_map = {
	.type		= BPF_MAP_TYPE_ARRAY,
	.key_size	= sizeof(int),
	.value_size	= sizeof(struct config),
	.max_entries	= 1,
};

/* Common stats data record (shared with userspace) */
struct datarec {
	__u64 processed;
	__u64 issue;
};

struct bpf_map_def SEC("maps") stats_global_map = {
	.type		= BPF_MAP_TYPE_PERCPU_ARRAY,
	.key_size	= sizeof(u32),
	.value_size	= sizeof(struct datarec),
	.max_entries	= 1,
};

#define MAX_RXQs 64

/* Stats per rx_queue_index (per CPU) */
struct bpf_map_def SEC("maps") rx_queue_index_map = {
	.type		= BPF_MAP_TYPE_PERCPU_ARRAY,
	.key_size	= sizeof(u32),
	.value_size	= sizeof(struct datarec),
	.max_entries	= MAX_RXQs + 1,
};

static __always_inline
void swap_src_dst_mac(void *data)
{
	unsigned short *p = data;
	unsigned short dst[3];

	dst[0] = p[0];
	dst[1] = p[1];
	dst[2] = p[2];
	p[0] = p[3];
	p[1] = p[4];
	p[2] = p[5];
	p[3] = dst[0];
	p[4] = dst[1];
	p[5] = dst[2];
}

SEC("xdp_prog0")
int  xdp_prognum0(struct xdp_md *ctx)
{
	void *data_end = (void *)(long)ctx->data_end;
	void *data     = (void *)(long)ctx->data;
	struct datarec *rec, *rxq_rec;
	int ingress_ifindex;
	struct config *config;
	u32 key = 0;

	/* Global stats record */
	rec = bpf_map_lookup_elem(&stats_global_map, &key);
	if (!rec)
		return XDP_ABORTED;
	rec->processed++;

	/* Accessing ctx->ingress_ifindex, cause BPF to rewrite BPF
	 * instructions inside kernel to access xdp_rxq->dev->ifindex
	 */
	ingress_ifindex = ctx->ingress_ifindex;

	config = bpf_map_lookup_elem(&config_map, &key);
	if (!config)
		return XDP_ABORTED;

	/* Simple test: check ctx provided ifindex is as expected */
	if (ingress_ifindex != config->ifindex) {
		/* count this error case */
		rec->issue++;
		return XDP_ABORTED;
	}

	/* Update stats per rx_queue_index. Handle if rx_queue_index
	 * is larger than stats map can contain info for.
	 */
	key = ctx->rx_queue_index;
	if (key >= MAX_RXQs)
		key = MAX_RXQs;
	rxq_rec = bpf_map_lookup_elem(&rx_queue_index_map, &key);
	if (!rxq_rec)
		return XDP_ABORTED;
	rxq_rec->processed++;
	if (key == MAX_RXQs)
		rxq_rec->issue++;

	/* Default: Don't touch packet data, only count packets */
	if (unlikely(config->options & (READ_MEM|SWAP_MAC))) {
		struct ethhdr *eth = data;

		if (eth + 1 > data_end)
			return XDP_ABORTED;

		/* Avoid compiler removing this: Drop non 802.3 Ethertypes */
		if (ntohs(eth->h_proto) < ETH_P_802_3_MIN)
			return XDP_ABORTED;

		/* XDP_TX requires changing MAC-addrs, else HW may drop.
		 * Can also be enabled with --swapmac (for test purposes)
		 */
		if (unlikely(config->options & SWAP_MAC))
			swap_src_dst_mac(data);
	}

	return config->action;
}

char _license[] SEC("license") = "GPL";
Commit	Line	Data
0fca931a JDB	1	/* SPDX-License-Identifier: GPL-2.0
	2	* Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
	3	*
	4	* Example howto extract XDP RX-queue info
	5	*/
	6	#include <uapi/linux/bpf.h>
0d25c43a JDB	7	#include <uapi/linux/if_ether.h>
0d25c43a JDB	8	#include <uapi/linux/in.h>
0fca931a JDB	9	#include "bpf_helpers.h"
	10
	11	/* Config setup from with userspace
	12	*
	13	* User-side setup ifindex in config_map, to verify that
	14	* ctx->ingress_ifindex is correct (against configured ifindex)
	15	*/
	16	struct config {
	17	__u32 action;
	18	int ifindex;
0d25c43a JDB	19	__u32 options;
	20	};
	21	enum cfg_options_flags {
	22	NO_TOUCH = 0x0U,
	23	READ_MEM = 0x1U,
509fda10	24	SWAP_MAC = 0x2U,
0fca931a JDB	25	};
	26	struct bpf_map_def SEC("maps") config_map = {
	27	.type = BPF_MAP_TYPE_ARRAY,
	28	.key_size = sizeof(int),
	29	.value_size = sizeof(struct config),
	30	.max_entries = 1,
	31	};
	32
	33	/* Common stats data record (shared with userspace) */
	34	struct datarec {
	35	__u64 processed;
	36	__u64 issue;
	37	};
	38
	39	struct bpf_map_def SEC("maps") stats_global_map = {
	40	.type = BPF_MAP_TYPE_PERCPU_ARRAY,
	41	.key_size = sizeof(u32),
	42	.value_size = sizeof(struct datarec),
	43	.max_entries = 1,
	44	};
	45
	46	#define MAX_RXQs 64
	47
	48	/* Stats per rx_queue_index (per CPU) */
	49	struct bpf_map_def SEC("maps") rx_queue_index_map = {
	50	.type = BPF_MAP_TYPE_PERCPU_ARRAY,
	51	.key_size = sizeof(u32),
	52	.value_size = sizeof(struct datarec),
	53	.max_entries = MAX_RXQs + 1,
	54	};
	55
509fda10 JDB	56	static __always_inline
	57	void swap_src_dst_mac(void *data)
	58	{
	59	unsigned short *p = data;
	60	unsigned short dst[3];
	61
	62	dst[0] = p[0];
	63	dst[1] = p[1];
	64	dst[2] = p[2];
	65	p[0] = p[3];
	66	p[1] = p[4];
	67	p[2] = p[5];
	68	p[3] = dst[0];
	69	p[4] = dst[1];
	70	p[5] = dst[2];
	71	}
	72
0fca931a JDB	73	SEC("xdp_prog0")
	74	int xdp_prognum0(struct xdp_md *ctx)
	75	{
	76	void data_end = (void )(long)ctx->data_end;
	77	void data = (void )(long)ctx->data;
	78	struct datarec rec, rxq_rec;
	79	int ingress_ifindex;
	80	struct config *config;
	81	u32 key = 0;
	82
	83	/* Global stats record */
	84	rec = bpf_map_lookup_elem(&stats_global_map, &key);
	85	if (!rec)
	86	return XDP_ABORTED;
	87	rec->processed++;
	88
	89	/* Accessing ctx->ingress_ifindex, cause BPF to rewrite BPF
	90	* instructions inside kernel to access xdp_rxq->dev->ifindex
	91	*/
	92	ingress_ifindex = ctx->ingress_ifindex;
	93
	94	config = bpf_map_lookup_elem(&config_map, &key);
	95	if (!config)
	96	return XDP_ABORTED;
	97
	98	/* Simple test: check ctx provided ifindex is as expected */
	99	if (ingress_ifindex != config->ifindex) {
	100	/* count this error case */
	101	rec->issue++;
	102	return XDP_ABORTED;
	103	}
	104
	105	/* Update stats per rx_queue_index. Handle if rx_queue_index
	106	* is larger than stats map can contain info for.
	107	*/
	108	key = ctx->rx_queue_index;
	109	if (key >= MAX_RXQs)
	110	key = MAX_RXQs;
	111	rxq_rec = bpf_map_lookup_elem(&rx_queue_index_map, &key);
	112	if (!rxq_rec)
	113	return XDP_ABORTED;
	114	rxq_rec->processed++;
	115	if (key == MAX_RXQs)
	116	rxq_rec->issue++;
	117
0d25c43a	118	/* Default: Don't touch packet data, only count packets */
509fda10	119	if (unlikely(config->options & (READ_MEM\|SWAP_MAC))) {
0d25c43a JDB	120	struct ethhdr *eth = data;
	121
	122	if (eth + 1 > data_end)
	123	return XDP_ABORTED;
	124
	125	/* Avoid compiler removing this: Drop non 802.3 Ethertypes */
	126	if (ntohs(eth->h_proto) < ETH_P_802_3_MIN)
	127	return XDP_ABORTED;
509fda10 JDB	128
	129	/* XDP_TX requires changing MAC-addrs, else HW may drop.
	130	* Can also be enabled with --swapmac (for test purposes)
	131	*/
	132	if (unlikely(config->options & SWAP_MAC))
	133	swap_src_dst_mac(data);
0d25c43a JDB	134	}
0d25c43a JDB	135
0fca931a JDB	136	return config->action;
	137	}
	138
	139	char _license[] SEC("license") = "GPL";