Merge "[NFCT.NS.3] Add netfilter conntrack event monitor" am: 9eefc7422a am:... (7929d116) · Commits · e / os / android_packages_modules_NetworkStack

common/moduleutils/Android.bp

+1 −0

Original line number	Diff line number	Diff line
		@@ -50,6 +50,7 @@ filegroup {
		filegroup {
		name: "tethering-module-utils-srcs",
		srcs: [
		"src/android/net/ip/ConntrackMonitor.java",
		"src/android/net/ip/InterfaceController.java",
		"src/android/net/ip/IpNeighborMonitor.java",
		"src/android/net/ip/NetlinkMonitor.java",

common/moduleutils/src/android/net/ip/ConntrackMonitor.java

0 → 100644

+79 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2020 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.ip;

		import android.net.netlink.ConntrackMessage;
		import android.net.netlink.NetlinkMessage;
		import android.net.util.SharedLog;
		import android.os.Handler;
		import android.system.OsConstants;

		import androidx.annotation.NonNull;

		/**
		* ConntrackMonitor.
		*
		* Monitors the netfilter conntrack notifications and presents to callers
		* ConntrackEvents describing each event.
		*
		* @hide
		*/
		public class ConntrackMonitor extends NetlinkMonitor {
		private static final String TAG = ConntrackMonitor.class.getSimpleName();
		private static final boolean DBG = false;
		private static final boolean VDBG = false;

		// Reference kernel/uapi/linux/netfilter/nfnetlink_compat.h
		public static final int NF_NETLINK_CONNTRACK_NEW = 1;
		public static final int NF_NETLINK_CONNTRACK_UPDATE = 2;
		public static final int NF_NETLINK_CONNTRACK_DESTROY = 4;

		/**
		* A class for describing parsed netfilter conntrack events.
		*/
		public static class ConntrackEvent { /TODO/ }

		/**
		* A callback to caller for conntrack event.
		*/
		public interface ConntrackEventConsumer {
		/**
		* Every conntrack event received on the netlink socket is passed in
		* here.
		*/
		void accept(@NonNull ConntrackEvent event);
		}

		private final ConntrackEventConsumer mConsumer;

		public ConntrackMonitor(@NonNull Handler h, @NonNull SharedLog log,
		@NonNull ConntrackEventConsumer cb) {
		super(h, log, TAG, OsConstants.NETLINK_NETFILTER, NF_NETLINK_CONNTRACK_NEW
		\| NF_NETLINK_CONNTRACK_UPDATE \| NF_NETLINK_CONNTRACK_DESTROY);
		mConsumer = cb;
		}

		@Override
		public void processNetlinkMessage(NetlinkMessage nlMsg, final long whenMs) {
		if (!(nlMsg instanceof ConntrackMessage)) {
		mLog.e("non-conntrack msg: " + nlMsg);
		return;
		}

		mConsumer.accept(new ConntrackEvent() /* TODO */);
		}
		}

common/netlinkclient/src/android/net/netlink/ConntrackMessage.java

+23 −4

Original line number	Diff line number	Diff line
		@@ -39,9 +39,6 @@ import java.nio.ByteOrder;
		public class ConntrackMessage extends NetlinkMessage {
		public static final int STRUCT_SIZE = StructNlMsgHdr.STRUCT_SIZE + StructNfGenMsg.STRUCT_SIZE;

		public static final short NFNL_SUBSYS_CTNETLINK = 1;
		public static final short IPCTNL_MSG_CT_NEW = 0;

		// enum ctattr_type
		public static final short CTA_TUPLE_ORIG = 1;
		public static final short CTA_TUPLE_REPLY = 2;
		@@ -84,7 +81,8 @@ public class ConntrackMessage extends NetlinkMessage {

		final ConntrackMessage ctmsg = new ConntrackMessage();
		ctmsg.mHeader.nlmsg_len = bytes.length;
		ctmsg.mHeader.nlmsg_type = (NFNL_SUBSYS_CTNETLINK << 8) \| IPCTNL_MSG_CT_NEW;
		ctmsg.mHeader.nlmsg_type = (NetlinkConstants.NFNL_SUBSYS_CTNETLINK << 8)
		\| NetlinkConstants.IPCTNL_MSG_CT_NEW;
		ctmsg.mHeader.nlmsg_flags = NLM_F_REQUEST \| NLM_F_ACK \| NLM_F_REPLACE;
		ctmsg.mHeader.nlmsg_seq = 1;
		ctmsg.pack(byteBuffer);
		@@ -95,6 +93,22 @@ public class ConntrackMessage extends NetlinkMessage {
		return bytes;
		}

		/**
		* Parses a netfilter conntrack message from a {@link ByteBuffer}.
		*
		* @param header the netlink message header.
		* @param byteBuffer The buffer from which to parse the netfilter conntrack message.
		* @return the parsed netfilter conntrack message, or {@code null} if the netfilter conntrack
		* message could not be parsed successfully (for example, if it was truncated).
		*/
		public static ConntrackMessage parse(StructNlMsgHdr header, ByteBuffer byteBuffer) {
		// Just build the netlink header for now and pretend the whole message was consumed.
		// TODO: Parse the netfilter message header and conntrack attributes.
		final ConntrackMessage conntrackMsg = new ConntrackMessage(header);
		byteBuffer.position(byteBuffer.limit());
		return conntrackMsg;
		}

		protected StructNfGenMsg mNfGenMsg;

		private ConntrackMessage() {
		@@ -102,6 +116,11 @@ public class ConntrackMessage extends NetlinkMessage {
		mNfGenMsg = new StructNfGenMsg((byte) OsConstants.AF_INET);
		}

		private ConntrackMessage(StructNlMsgHdr header) {
		super(header);
		mNfGenMsg = null;
		}

		public void pack(ByteBuffer byteBuffer) {
		mHeader.pack(byteBuffer);
		mNfGenMsg.pack(byteBuffer);

common/netlinkclient/src/android/net/netlink/NetlinkConstants.java

+68 −27

Original line number	Diff line number	Diff line
		@@ -27,8 +27,10 @@ import java.nio.ByteBuffer;
		*
		* Values taken from:
		*
		* <linux_src>/include/uapi/linux/netlink.h
		* <linux_src>/include/uapi/linux/rtnetlink.h
		* include/uapi/linux/netfilter/nfnetlink.h
		* include/uapi/linux/netfilter/nfnetlink_conntrack.h
		* include/uapi/linux/netlink.h
		* include/uapi/linux/rtnetlink.h
		*
		* @hide
		*/
		@@ -104,7 +106,21 @@ public class NetlinkConstants {
		public static final short RTM_GETRULE = 34;
		public static final short RTM_NEWNDUSEROPT = 68;

		/* see <linux_src>/include/uapi/linux/sock_diag.h */
		// 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.
		@@ -163,6 +179,30 @@ public class NetlinkConstants {
		}
		}

		/**
		* 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.
		*/
		@@ -177,6 +217,7 @@ public class NetlinkConstants {
		// 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);
		}

common/netlinkclient/src/android/net/netlink/NetlinkMessage.java

+16 −0

Original line number	Diff line number	Diff line
		@@ -74,6 +74,9 @@ public class NetlinkMessage {
		if (nlFamily == OsConstants.NETLINK_INET_DIAG) {
		return parseInetDiagMessage(nlmsghdr, byteBuffer);
		}
		if (nlFamily == OsConstants.NETLINK_NETFILTER) {
		return parseNfMessage(nlmsghdr, byteBuffer);
		}

		return null;
		}
		@@ -136,4 +139,17 @@ public class NetlinkMessage {
		default: return null;
		}
		}

		@Nullable
		private static NetlinkMessage parseNfMessage(@NonNull StructNlMsgHdr nlmsghdr,
		@NonNull ByteBuffer byteBuffer) {
		switch (nlmsghdr.nlmsg_type) {
		case NetlinkConstants.NFNL_SUBSYS_CTNETLINK << 8
		\| NetlinkConstants.IPCTNL_MSG_CT_NEW:
		case NetlinkConstants.NFNL_SUBSYS_CTNETLINK << 8
		\| NetlinkConstants.IPCTNL_MSG_CT_DELETE:
		return (NetlinkMessage) ConntrackMessage.parse(nlmsghdr, byteBuffer);
		default: return null;
		}
		}
		}