forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
140 lines
3.2 KiB
140 lines
3.2 KiB
/* 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/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 { |
|
__uint(type, BPF_MAP_TYPE_ARRAY); |
|
__type(key, int); |
|
__type(value, struct config); |
|
__uint(max_entries, 1); |
|
} config_map SEC(".maps"); |
|
|
|
/* Common stats data record (shared with userspace) */ |
|
struct datarec { |
|
__u64 processed; |
|
__u64 issue; |
|
}; |
|
|
|
struct { |
|
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); |
|
__type(key, u32); |
|
__type(value, struct datarec); |
|
__uint(max_entries, 1); |
|
} stats_global_map SEC(".maps"); |
|
|
|
#define MAX_RXQs 64 |
|
|
|
/* Stats per rx_queue_index (per CPU) */ |
|
struct { |
|
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); |
|
__type(key, u32); |
|
__type(value, struct datarec); |
|
__uint(max_entries, MAX_RXQs + 1); |
|
} rx_queue_index_map SEC(".maps"); |
|
|
|
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";
|
|
|