[mirror_ubuntu-jammy-kernel.git] / samples / bpf / xdp_redirect_map_kern.c

/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 */
#define KBUILD_MODNAME "foo"
#include <uapi/linux/bpf.h>
#include <linux/in.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
#include <linux/if_vlan.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <bpf/bpf_helpers.h>

/* The 2nd xdp prog on egress does not support skb mode, so we define two
 * maps, tx_port_general and tx_port_native.
 */
struct {
	__uint(type, BPF_MAP_TYPE_DEVMAP);
	__uint(key_size, sizeof(int));
	__uint(value_size, sizeof(int));
	__uint(max_entries, 100);
} tx_port_general SEC(".maps");

struct {
	__uint(type, BPF_MAP_TYPE_DEVMAP);
	__uint(key_size, sizeof(int));
	__uint(value_size, sizeof(struct bpf_devmap_val));
	__uint(max_entries, 100);
} tx_port_native SEC(".maps");

/* Count RX packets, as XDP bpf_prog doesn't get direct TX-success
 * feedback.  Redirect TX errors can be caught via a tracepoint.
 */
struct {
	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
	__type(key, u32);
	__type(value, long);
	__uint(max_entries, 1);
} rxcnt SEC(".maps");

/* map to store egress interface mac address */
struct {
	__uint(type, BPF_MAP_TYPE_ARRAY);
	__type(key, u32);
	__type(value, __be64);
	__uint(max_entries, 1);
} tx_mac SEC(".maps");

static 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];
}

static __always_inline int xdp_redirect_map(struct xdp_md *ctx, void *redirect_map)
{
	void *data_end = (void *)(long)ctx->data_end;
	void *data = (void *)(long)ctx->data;
	struct ethhdr *eth = data;
	int rc = XDP_DROP;
	long *value;
	u32 key = 0;
	u64 nh_off;
	int vport;

	nh_off = sizeof(*eth);
	if (data + nh_off > data_end)
		return rc;

	/* constant virtual port */
	vport = 0;

	/* count packet in global counter */
	value = bpf_map_lookup_elem(&rxcnt, &key);
	if (value)
		*value += 1;

	swap_src_dst_mac(data);

	/* send packet out physical port */
	return bpf_redirect_map(redirect_map, vport, 0);
}

SEC("xdp_redirect_general")
int xdp_redirect_map_general(struct xdp_md *ctx)
{
	return xdp_redirect_map(ctx, &tx_port_general);
}

SEC("xdp_redirect_native")
int xdp_redirect_map_native(struct xdp_md *ctx)
{
	return xdp_redirect_map(ctx, &tx_port_native);
}

SEC("xdp_devmap/map_prog")
int xdp_redirect_map_egress(struct xdp_md *ctx)
{
	void *data_end = (void *)(long)ctx->data_end;
	void *data = (void *)(long)ctx->data;
	struct ethhdr *eth = data;
	__be64 *mac;
	u32 key = 0;
	u64 nh_off;

	nh_off = sizeof(*eth);
	if (data + nh_off > data_end)
		return XDP_DROP;

	mac = bpf_map_lookup_elem(&tx_mac, &key);
	if (mac)
		__builtin_memcpy(eth->h_source, mac, ETH_ALEN);

	return XDP_PASS;
}

/* Redirect require an XDP bpf_prog loaded on the TX device */
SEC("xdp_redirect_dummy")
int xdp_redirect_dummy_prog(struct xdp_md *ctx)
{
	return XDP_PASS;
}

char _license[] SEC("license") = "GPL";
Commit	Line	Data
9d6e0052 JF	1	/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
	2	*
	3	* This program is free software; you can redistribute it and/or
	4	* modify it under the terms of version 2 of the GNU General Public
	5	* License as published by the Free Software Foundation.
	6	*
	7	* This program is distributed in the hope that it will be useful, but
	8	* WITHOUT ANY WARRANTY; without even the implied warranty of
	9	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	10	* General Public License for more details.
	11	*/
	12	#define KBUILD_MODNAME "foo"
	13	#include <uapi/linux/bpf.h>
	14	#include <linux/in.h>
	15	#include <linux/if_ether.h>
	16	#include <linux/if_packet.h>
	17	#include <linux/if_vlan.h>
	18	#include <linux/ip.h>
	19	#include <linux/ipv6.h>
7cf245a3	20	#include <bpf/bpf_helpers.h>
9d6e0052	21
6e66fbb1 HL	22	/* The 2nd xdp prog on egress does not support skb mode, so we define two
	23	* maps, tx_port_general and tx_port_native.
	24	*/
451d1dc8 DL	25	struct {
	26	__uint(type, BPF_MAP_TYPE_DEVMAP);
	27	__uint(key_size, sizeof(int));
	28	__uint(value_size, sizeof(int));
	29	__uint(max_entries, 100);
6e66fbb1 HL	30	} tx_port_general SEC(".maps");
	31
	32	struct {
	33	__uint(type, BPF_MAP_TYPE_DEVMAP);
	34	__uint(key_size, sizeof(int));
	35	__uint(value_size, sizeof(struct bpf_devmap_val));
	36	__uint(max_entries, 100);
	37	} tx_port_native SEC(".maps");
9d6e0052	38
306da4e6 JDB	39	/* Count RX packets, as XDP bpf_prog doesn't get direct TX-success
	40	* feedback. Redirect TX errors can be caught via a tracepoint.
	41	*/
451d1dc8 DL	42	struct {
	43	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
	44	__type(key, u32);
	45	__type(value, long);
	46	__uint(max_entries, 1);
	47	} rxcnt SEC(".maps");
9d6e0052	48
6e66fbb1 HL	49	/* map to store egress interface mac address */
	50	struct {
	51	__uint(type, BPF_MAP_TYPE_ARRAY);
	52	__type(key, u32);
	53	__type(value, __be64);
	54	__uint(max_entries, 1);
	55	} tx_mac SEC(".maps");
	56
9d6e0052 JF	57	static 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
6e66fbb1	73	static __always_inline int xdp_redirect_map(struct xdp_md ctx, void redirect_map)
9d6e0052 JF	74	{
	75	void data_end = (void )(long)ctx->data_end;
	76	void data = (void )(long)ctx->data;
	77	struct ethhdr *eth = data;
	78	int rc = XDP_DROP;
9d6e0052 JF	79	long *value;
	80	u32 key = 0;
	81	u64 nh_off;
6e66fbb1	82	int vport;
9d6e0052 JF	83
	84	nh_off = sizeof(*eth);
	85	if (data + nh_off > data_end)
	86	return rc;
	87
	88	/* constant virtual port */
	89	vport = 0;
	90
	91	/* count packet in global counter */
	92	value = bpf_map_lookup_elem(&rxcnt, &key);
	93	if (value)
	94	*value += 1;
	95
	96	swap_src_dst_mac(data);
	97
	98	/* send packet out physical port */
6e66fbb1 HL	99	return bpf_redirect_map(redirect_map, vport, 0);
	100	}
	101
	102	SEC("xdp_redirect_general")
	103	int xdp_redirect_map_general(struct xdp_md *ctx)
	104	{
	105	return xdp_redirect_map(ctx, &tx_port_general);
	106	}
	107
	108	SEC("xdp_redirect_native")
	109	int xdp_redirect_map_native(struct xdp_md *ctx)
	110	{
	111	return xdp_redirect_map(ctx, &tx_port_native);
	112	}
	113
	114	SEC("xdp_devmap/map_prog")
	115	int xdp_redirect_map_egress(struct xdp_md *ctx)
	116	{
	117	void data_end = (void )(long)ctx->data_end;
	118	void data = (void )(long)ctx->data;
	119	struct ethhdr *eth = data;
	120	__be64 *mac;
	121	u32 key = 0;
	122	u64 nh_off;
	123
	124	nh_off = sizeof(*eth);
	125	if (data + nh_off > data_end)
	126	return XDP_DROP;
	127
	128	mac = bpf_map_lookup_elem(&tx_mac, &key);
	129	if (mac)
	130	__builtin_memcpy(eth->h_source, mac, ETH_ALEN);
	131
	132	return XDP_PASS;
9d6e0052 JF	133	}
9d6e0052 JF	134
306da4e6 JDB	135	/* Redirect require an XDP bpf_prog loaded on the TX device */
306da4e6 JDB	136	SEC("xdp_redirect_dummy")
3edcf18e	137	int xdp_redirect_dummy_prog(struct xdp_md *ctx)
306da4e6 JDB	138	{
	139	return XDP_PASS;
	140	}
	141
9d6e0052	142	char _license[] SEC("license") = "GPL";