mirror of
https://github.com/netbirdio/gvisor.git
synced 2026-05-22 17:12:49 -07:00
51 lines
1.8 KiB
C
51 lines
1.8 KiB
C
// Copyright 2022 The gVisor Authors.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
// clang-format off
|
|
// Contains types needed by later headers.
|
|
#include <linux/types.h>
|
|
// clang-format on
|
|
#include <bpf/bpf_helpers.h>
|
|
#include <linux/bpf.h>
|
|
|
|
#define section(secname) __attribute__((section(secname), used))
|
|
|
|
char __license[] section("license") = "Apache-2.0";
|
|
|
|
// Note: bpf_helpers.h includes a struct definition for bpf_map_def in some, but
|
|
// not all, environments. Define our own equivalent struct to avoid issues with
|
|
// multiple declarations.
|
|
struct gvisor_bpf_map_def {
|
|
unsigned int type;
|
|
unsigned int key_size;
|
|
unsigned int value_size;
|
|
unsigned int max_entries;
|
|
unsigned int map_flags;
|
|
};
|
|
|
|
// A map of RX queue number to AF_XDP socket. We only ever use one key: 0.
|
|
struct gvisor_bpf_map_def section("maps") sock_map = {
|
|
.type = BPF_MAP_TYPE_XSKMAP, // Note: "XSK" means AF_XDP socket.
|
|
.key_size = sizeof(int),
|
|
.value_size = sizeof(int),
|
|
.max_entries = 1,
|
|
};
|
|
|
|
section("xdp") int xdp_prog(struct xdp_md *ctx) {
|
|
// Lookup the socket for the current RX queue. Veth devices by default have
|
|
// only one RX queue. If one is found, redirect the packet to that socket.
|
|
// Otherwise pass it on to the kernel network stack.
|
|
return bpf_redirect_map(&sock_map, ctx->rx_queue_index, XDP_PASS);
|
|
}
|