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/* 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 "vmlinux.h"
#include "xdp_sample.bpf.h"
#include "xdp_sample_shared.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, 1);
} 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, 1);
} tx_port_native SEC(".maps");
/* store egress interface mac address */
const volatile __u8 tx_mac_addr[ETH_ALEN];
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;
u32 key = bpf_get_smp_processor_id();
struct ethhdr *eth = data;
struct datarec *rec;
u64 nh_off;
nh_off = sizeof(*eth);
if (data + nh_off > data_end)
return XDP_DROP;
rec = bpf_map_lookup_elem(&rx_cnt, &key);
if (!rec)
return XDP_PASS;
NO_TEAR_INC(rec->processed);
swap_src_dst_mac(data);
return bpf_redirect_map(redirect_map, 0, 0);
}
SEC("xdp")
int xdp_redirect_map_general(struct xdp_md *ctx)
{
return xdp_redirect_map(ctx, &tx_port_general);
}
SEC("xdp")
int xdp_redirect_map_native(struct xdp_md *ctx)
{
return xdp_redirect_map(ctx, &tx_port_native);
}
SEC("xdp/devmap")
int xdp_redirect_map_egress(struct xdp_md *ctx)
{
void *data_end = (void *)(long)ctx->data_end;
void *data = (void *)(long)ctx->data;
u8 *mac_addr = (u8 *) tx_mac_addr;
struct ethhdr *eth = data;
u64 nh_off;
nh_off = sizeof(*eth);
if (data + nh_off > data_end)
return XDP_DROP;
barrier_var(mac_addr); /* prevent optimizing out memcpy */
__builtin_memcpy(eth->h_source, mac_addr, ETH_ALEN);
return XDP_PASS;
}
/* Redirect require an XDP bpf_prog loaded on the TX device */
SEC("xdp")
int xdp_redirect_dummy_prog(struct xdp_md *ctx)
{
return XDP_PASS;
}
char _license[] SEC("license") = "GPL";
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