1 /* 2 * Copyright (C) 2022 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package com.android.net.module.util; 17 18 import android.os.Build; 19 20 import androidx.annotation.NonNull; 21 import androidx.annotation.RequiresApi; 22 23 import java.io.IOException; 24 25 /** 26 * The classes and the methods for BPF utilization. 27 * 28 * {@hide} 29 */ 30 @RequiresApi(Build.VERSION_CODES.TIRAMISU) 31 public class BpfUtils { 32 static { JniUtil.getJniLibraryName()33 System.loadLibrary(JniUtil.getJniLibraryName(BpfUtils.class.getPackage())); 34 } 35 36 // Defined in include/uapi/linux/bpf.h. Only adding the CGROUPS currently being used for now. 37 public static final int BPF_CGROUP_INET_INGRESS = 0; 38 public static final int BPF_CGROUP_INET_EGRESS = 1; 39 public static final int BPF_CGROUP_INET_SOCK_CREATE = 2; 40 public static final int BPF_CGROUP_INET4_BIND = 8; 41 public static final int BPF_CGROUP_INET6_BIND = 9; 42 public static final int BPF_CGROUP_INET4_CONNECT = 10; 43 public static final int BPF_CGROUP_INET6_CONNECT = 11; 44 public static final int BPF_CGROUP_UDP4_SENDMSG = 14; 45 public static final int BPF_CGROUP_UDP6_SENDMSG = 15; 46 public static final int BPF_CGROUP_UDP4_RECVMSG = 19; 47 public static final int BPF_CGROUP_UDP6_RECVMSG = 20; 48 public static final int BPF_CGROUP_GETSOCKOPT = 21; 49 public static final int BPF_CGROUP_SETSOCKOPT = 22; 50 public static final int BPF_CGROUP_INET_SOCK_RELEASE = 34; 51 52 // Note: This is only guaranteed to be accurate on U+ devices. It is likely to be accurate 53 // on T+ devices as well, but this is not guaranteed. 54 public static final String CGROUP_PATH = "/sys/fs/cgroup/"; 55 56 /** 57 * Get BPF program Id from CGROUP. 58 * 59 * Note: This requires a 4.19 kernel which is only guaranteed on V+. 60 * 61 * @param attachType Bpf attach type. See bpf_attach_type in include/uapi/linux/bpf.h. 62 * @return Positive integer for a Program Id. 0 if no program is attached. 63 * @throws IOException if failed to open the cgroup directory or query bpf program. 64 */ getProgramId(int attachType)65 public static int getProgramId(int attachType) throws IOException { 66 return native_getProgramIdFromCgroup(attachType, CGROUP_PATH); 67 } 68 native_getProgramIdFromCgroup(int type, String cgroupPath)69 private static native int native_getProgramIdFromCgroup(int type, String cgroupPath) 70 throws IOException; 71 } 72