| /* |
| * Copyright (C) 2015 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. |
| */ |
| |
| package android.net.netlink; |
| |
| import android.annotation.NonNull; |
| import android.system.OsConstants; |
| |
| import java.nio.ByteBuffer; |
| |
| |
| /** |
| * Various constants and static helper methods for netlink communications. |
| * |
| * Values taken from: |
| * |
| * include/uapi/linux/netfilter/nfnetlink.h |
| * include/uapi/linux/netfilter/nfnetlink_conntrack.h |
| * include/uapi/linux/netlink.h |
| * include/uapi/linux/rtnetlink.h |
| * |
| * @hide |
| */ |
| public class NetlinkConstants { |
| private NetlinkConstants() {} |
| |
| public static final int NLA_ALIGNTO = 4; |
| /** |
| * Flag for dumping struct tcp_info. |
| * Corresponding to enum definition in external/strace/linux/inet_diag.h. |
| */ |
| public static final int INET_DIAG_MEMINFO = 1; |
| |
| public static final int SOCKDIAG_MSG_HEADER_SIZE = |
| StructNlMsgHdr.STRUCT_SIZE + StructInetDiagMsg.STRUCT_SIZE; |
| |
| public static final int alignedLengthOf(short length) { |
| final int intLength = (int) length & 0xffff; |
| return alignedLengthOf(intLength); |
| } |
| |
| public static final int alignedLengthOf(int length) { |
| if (length <= 0) { return 0; } |
| return (((length + NLA_ALIGNTO - 1) / NLA_ALIGNTO) * NLA_ALIGNTO); |
| } |
| |
| public static String stringForAddressFamily(int family) { |
| if (family == OsConstants.AF_INET) { return "AF_INET"; } |
| if (family == OsConstants.AF_INET6) { return "AF_INET6"; } |
| if (family == OsConstants.AF_NETLINK) { return "AF_NETLINK"; } |
| return String.valueOf(family); |
| } |
| |
| public static String stringForProtocol(int protocol) { |
| if (protocol == OsConstants.IPPROTO_TCP) { return "IPPROTO_TCP"; } |
| if (protocol == OsConstants.IPPROTO_UDP) { return "IPPROTO_UDP"; } |
| return String.valueOf(protocol); |
| } |
| |
| public static String hexify(byte[] bytes) { |
| if (bytes == null) { return "(null)"; } |
| return toHexString(bytes, 0, bytes.length); |
| } |
| |
| public static String hexify(ByteBuffer buffer) { |
| if (buffer == null) { return "(null)"; } |
| return toHexString( |
| buffer.array(), buffer.position(), buffer.remaining()); |
| } |
| |
| // Known values for struct nlmsghdr nlm_type. |
| public static final short NLMSG_NOOP = 1; // Nothing |
| public static final short NLMSG_ERROR = 2; // Error |
| public static final short NLMSG_DONE = 3; // End of a dump |
| public static final short NLMSG_OVERRUN = 4; // Data lost |
| public static final short NLMSG_MAX_RESERVED = 15; // Max reserved value |
| |
| public static final short RTM_NEWLINK = 16; |
| public static final short RTM_DELLINK = 17; |
| public static final short RTM_GETLINK = 18; |
| public static final short RTM_SETLINK = 19; |
| public static final short RTM_NEWADDR = 20; |
| public static final short RTM_DELADDR = 21; |
| public static final short RTM_GETADDR = 22; |
| public static final short RTM_NEWROUTE = 24; |
| public static final short RTM_DELROUTE = 25; |
| public static final short RTM_GETROUTE = 26; |
| public static final short RTM_NEWNEIGH = 28; |
| public static final short RTM_DELNEIGH = 29; |
| public static final short RTM_GETNEIGH = 30; |
| public static final short RTM_NEWRULE = 32; |
| public static final short RTM_DELRULE = 33; |
| public static final short RTM_GETRULE = 34; |
| public static final short RTM_NEWNDUSEROPT = 68; |
| |
| // Netfilter netlink message types are presented by two bytes: high byte subsystem and |
| // low byte operation. See the macro NFNL_SUBSYS_ID and NFNL_MSG_TYPE in |
| // include/uapi/linux/netfilter/nfnetlink.h |
| public static final short NFNL_SUBSYS_CTNETLINK = 1; |
| |
| public static final short IPCTNL_MSG_CT_NEW = 0; |
| public static final short IPCTNL_MSG_CT_GET = 1; |
| public static final short IPCTNL_MSG_CT_DELETE = 2; |
| public static final short IPCTNL_MSG_CT_GET_CTRZERO = 3; |
| public static final short IPCTNL_MSG_CT_GET_STATS_CPU = 4; |
| public static final short IPCTNL_MSG_CT_GET_STATS = 5; |
| public static final short IPCTNL_MSG_CT_GET_DYING = 6; |
| public static final short IPCTNL_MSG_CT_GET_UNCONFIRMED = 7; |
| |
| /* see include/uapi/linux/sock_diag.h */ |
| public static final short SOCK_DIAG_BY_FAMILY = 20; |
| |
| // Netlink groups. |
| public static final int RTNLGRP_ND_USEROPT = 20; |
| public static final int RTMGRP_ND_USEROPT = 1 << (RTNLGRP_ND_USEROPT - 1); |
| |
| /** |
| * Convert a netlink message type to a string for control message. |
| */ |
| @NonNull |
| private static String stringForCtlMsgType(short nlmType) { |
| switch (nlmType) { |
| case NLMSG_NOOP: return "NLMSG_NOOP"; |
| case NLMSG_ERROR: return "NLMSG_ERROR"; |
| case NLMSG_DONE: return "NLMSG_DONE"; |
| case NLMSG_OVERRUN: return "NLMSG_OVERRUN"; |
| default: return "unknown control message type: " + String.valueOf(nlmType); |
| } |
| } |
| |
| /** |
| * Convert a netlink message type to a string for NETLINK_ROUTE. |
| */ |
| @NonNull |
| private static String stringForRtMsgType(short nlmType) { |
| switch (nlmType) { |
| case RTM_NEWLINK: return "RTM_NEWLINK"; |
| case RTM_DELLINK: return "RTM_DELLINK"; |
| case RTM_GETLINK: return "RTM_GETLINK"; |
| case RTM_SETLINK: return "RTM_SETLINK"; |
| case RTM_NEWADDR: return "RTM_NEWADDR"; |
| case RTM_DELADDR: return "RTM_DELADDR"; |
| case RTM_GETADDR: return "RTM_GETADDR"; |
| case RTM_NEWROUTE: return "RTM_NEWROUTE"; |
| case RTM_DELROUTE: return "RTM_DELROUTE"; |
| case RTM_GETROUTE: return "RTM_GETROUTE"; |
| case RTM_NEWNEIGH: return "RTM_NEWNEIGH"; |
| case RTM_DELNEIGH: return "RTM_DELNEIGH"; |
| case RTM_GETNEIGH: return "RTM_GETNEIGH"; |
| case RTM_NEWRULE: return "RTM_NEWRULE"; |
| case RTM_DELRULE: return "RTM_DELRULE"; |
| case RTM_GETRULE: return "RTM_GETRULE"; |
| case RTM_NEWNDUSEROPT: return "RTM_NEWNDUSEROPT"; |
| default: return "unknown RTM type: " + String.valueOf(nlmType); |
| } |
| } |
| |
| /** |
| * Convert a netlink message type to a string for NETLINK_INET_DIAG. |
| */ |
| @NonNull |
| private static String stringForInetDiagMsgType(short nlmType) { |
| switch (nlmType) { |
| case SOCK_DIAG_BY_FAMILY: return "SOCK_DIAG_BY_FAMILY"; |
| default: return "unknown SOCK_DIAG type: " + String.valueOf(nlmType); |
| } |
| } |
| |
| /** |
| * Convert a netlink message type to a string for NETLINK_NETFILTER. |
| */ |
| @NonNull |
| private static String stringForNfMsgType(short nlmType) { |
| final byte subsysId = (byte) (nlmType >> 8); |
| final byte msgType = (byte) nlmType; |
| switch (subsysId) { |
| case NFNL_SUBSYS_CTNETLINK: |
| switch (msgType) { |
| case IPCTNL_MSG_CT_NEW: return "IPCTNL_MSG_CT_NEW"; |
| case IPCTNL_MSG_CT_GET: return "IPCTNL_MSG_CT_GET"; |
| case IPCTNL_MSG_CT_DELETE: return "IPCTNL_MSG_CT_DELETE"; |
| case IPCTNL_MSG_CT_GET_CTRZERO: return "IPCTNL_MSG_CT_GET_CTRZERO"; |
| case IPCTNL_MSG_CT_GET_STATS_CPU: return "IPCTNL_MSG_CT_GET_STATS_CPU"; |
| case IPCTNL_MSG_CT_GET_STATS: return "IPCTNL_MSG_CT_GET_STATS"; |
| case IPCTNL_MSG_CT_GET_DYING: return "IPCTNL_MSG_CT_GET_DYING"; |
| case IPCTNL_MSG_CT_GET_UNCONFIRMED: return "IPCTNL_MSG_CT_GET_UNCONFIRMED"; |
| } |
| break; |
| } |
| return "unknown NETFILTER type: " + String.valueOf(nlmType); |
| } |
| |
| /** |
| * Convert a netlink message type to a string by netlink family. |
| */ |
| @NonNull |
| public static String stringForNlMsgType(short nlmType, int nlFamily) { |
| // Reserved control messages. The netlink family is ignored. |
| // See NLMSG_MIN_TYPE in include/uapi/linux/netlink.h. |
| if (nlmType <= NLMSG_MAX_RESERVED) return stringForCtlMsgType(nlmType); |
| |
| // Netlink family messages. The netlink family is required. Note that the reason for using |
| // if-statement is that switch-case can't be used because the OsConstants.NETLINK_* are |
| // not constant. |
| if (nlFamily == OsConstants.NETLINK_ROUTE) return stringForRtMsgType(nlmType); |
| if (nlFamily == OsConstants.NETLINK_INET_DIAG) return stringForInetDiagMsgType(nlmType); |
| if (nlFamily == OsConstants.NETLINK_NETFILTER) return stringForNfMsgType(nlmType); |
| |
| return "unknown type: " + String.valueOf(nlmType); |
| } |
| |
| private static final char[] HEX_DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
| 'A', 'B', 'C', 'D', 'E', 'F' }; |
| /** |
| * Convert a byte array to a hexadecimal string. |
| */ |
| public static String toHexString(byte[] array, int offset, int length) { |
| char[] buf = new char[length * 2]; |
| |
| int bufIndex = 0; |
| for (int i = offset; i < offset + length; i++) { |
| byte b = array[i]; |
| buf[bufIndex++] = HEX_DIGITS[(b >>> 4) & 0x0F]; |
| buf[bufIndex++] = HEX_DIGITS[b & 0x0F]; |
| } |
| |
| return new String(buf); |
| } |
| } |
