16193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline/* 26193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * Copyright (C) 2015 The Android Open Source Project 36193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * 46193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * Licensed under the Apache License, Version 2.0 (the "License"); 56193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * you may not use this file except in compliance with the License. 66193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * You may obtain a copy of the License at 76193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * 86193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * http://www.apache.org/licenses/LICENSE-2.0 96193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * 106193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * Unless required by applicable law or agreed to in writing, software 116193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * distributed under the License is distributed on an "AS IS" BASIS, 126193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 136193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * See the License for the specific language governing permissions and 146193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * limitations under the License. 156193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline */ 166193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 176193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Klinepackage android.net.netlink; 186193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 196193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Klineimport android.system.Os; 206193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Klineimport android.system.OsConstants; 216193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 226193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Klineimport java.nio.ByteBuffer; 236193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 246193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 256193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline/** 266193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * struct nda_cacheinfo 276193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * 286193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * see: <linux_src>/include/uapi/linux/neighbour.h 296193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * 306193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * @hide 316193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline */ 326193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Klinepublic class StructNdaCacheInfo { 336193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline // Already aligned. 346193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline public static final int STRUCT_SIZE = 16; 356193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 366193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline private static boolean hasAvailableSpace(ByteBuffer byteBuffer) { 376193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline return byteBuffer != null && byteBuffer.remaining() >= STRUCT_SIZE; 386193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline } 396193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 406193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline public static StructNdaCacheInfo parse(ByteBuffer byteBuffer) { 416193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline if (!hasAvailableSpace(byteBuffer)) { return null; } 426193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 436193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline // The ByteOrder must have already been set by the caller. In most 446193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline // cases ByteOrder.nativeOrder() is correct, with the possible 456193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline // exception of usage within unittests. 466193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline final StructNdaCacheInfo struct = new StructNdaCacheInfo(); 476193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline struct.ndm_used = byteBuffer.getInt(); 486193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline struct.ndm_confirmed = byteBuffer.getInt(); 496193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline struct.ndm_updated = byteBuffer.getInt(); 506193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline struct.ndm_refcnt = byteBuffer.getInt(); 516193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline return struct; 526193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline } 536193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 546193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline // TODO: investigate whether this can change during device runtime and 556193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline // decide what (if anything) should be done about that. 566193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline private static final long CLOCK_TICKS_PER_SECOND = Os.sysconf(OsConstants._SC_CLK_TCK); 576193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 586193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline private static long ticksToMilliSeconds(int intClockTicks) { 596193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline final long longClockTicks = (long) intClockTicks & 0xffffffff; 606193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline return (longClockTicks * 1000) / CLOCK_TICKS_PER_SECOND; 616193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline } 626193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 636193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline /** 646193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * Explanatory notes, for reference. 656193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * 666193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * Before being returned to user space, the neighbor entry times are 676193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * converted to clock_t's like so: 686193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * 696193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * ndm_used = jiffies_to_clock_t(now - neigh->used); 706193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * ndm_confirmed = jiffies_to_clock_t(now - neigh->confirmed); 716193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * ndm_updated = jiffies_to_clock_t(now - neigh->updated); 726193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * 736193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * meaning that these values are expressed as "clock ticks ago". To 746193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * convert these clock ticks to seconds divide by sysconf(_SC_CLK_TCK). 756193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * When _SC_CLK_TCK is 100, for example, the ndm_* times are expressed 766193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * in centiseconds. 776193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * 786193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * These values are unsigned, but fortunately being expressed as "some 796193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * clock ticks ago", these values are typically very small (and 806193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * 2^31 centiseconds = 248 days). 816193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * 826193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * By observation, it appears that: 836193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * ndm_used: the last time ARP/ND took place for this neighbor 846193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * ndm_confirmed: the last time ARP/ND succeeded for this neighbor OR 856193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * higher layer confirmation (TCP or MSG_CONFIRM) 866193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * was received 876193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline * ndm_updated: the time when the current NUD state was entered 886193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline */ 896193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline public int ndm_used; 906193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline public int ndm_confirmed; 916193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline public int ndm_updated; 926193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline public int ndm_refcnt; 936193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 946193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline public StructNdaCacheInfo() {} 956193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 966193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline public long lastUsed() { 976193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline return ticksToMilliSeconds(ndm_used); 986193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline } 996193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 1006193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline public long lastConfirmed() { 1016193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline return ticksToMilliSeconds(ndm_confirmed); 1026193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline } 1036193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 1046193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline public long lastUpdated() { 1056193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline return ticksToMilliSeconds(ndm_updated); 1066193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline } 1076193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline 1086193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline @Override 1096193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline public String toString() { 1106193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline return "NdaCacheInfo{ " 1116193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline + "ndm_used{" + lastUsed() + "}, " 1126193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline + "ndm_confirmed{" + lastConfirmed() + "}, " 1136193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline + "ndm_updated{" + lastUpdated() + "}, " 1146193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline + "ndm_refcnt{" + ndm_refcnt + "} " 1156193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline + "}"; 1166193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline } 1176193aa3305bc2aa5b7f0a983f4b08c99065cfb82Erik Kline} 118