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/*
* Copyright (C) 2021 The Android Open Source Project
*
* 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.
*/
#include <linux/if_ether.h>
#include <linux/in.h>
#include <linux/ip.h>
// The resulting .o needs to load on the Android S bpfloader
#define BPFLOADER_MIN_VER BPFLOADER_S_VERSION
#include "bpf_helpers.h"
#include "bpf_net_helpers.h"
#include "bpf_tethering.h"
// Used only by TetheringPrivilegedTests, not by production code.
DEFINE_BPF_MAP_GRW(tether_downstream6_map, HASH, TetherDownstream6Key, Tether6Value, 16,
AID_NETWORK_STACK)
// Used only by BpfBitmapTest, not by production code.
DEFINE_BPF_MAP_GRW(bitmap, ARRAY, int, uint64_t, 2,
AID_NETWORK_STACK)
DEFINE_BPF_PROG_KVER("xdp/drop_ipv4_udp_ether", AID_ROOT, AID_NETWORK_STACK,
xdp_test, KVER(5, 9, 0))
(struct xdp_md *ctx) {
void *data = (void *)(long)ctx->data;
void *data_end = (void *)(long)ctx->data_end;
struct ethhdr *eth = data;
int hsize = sizeof(*eth);
struct iphdr *ip = data + hsize;
hsize += sizeof(struct iphdr);
if (data + hsize > data_end) return XDP_PASS;
if (eth->h_proto != htons(ETH_P_IP)) return XDP_PASS;
if (ip->protocol == IPPROTO_UDP) return XDP_DROP;
return XDP_PASS;
}
LICENSE("Apache 2.0");
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