Android7.1 關閉路由器DHCP後還能獲取到ip地址
阿新 • • 發佈：2021-12-14
frameworks\base\services\net\java\android\net\dhcp\DhcpClient.java
確定mIsIpRecoverEnabled=false;解決此問題。
原因：
private boolean doIpRecover() {
if (mIsIpRecoverEnabled == false) {
Log.d(TAG, "IP recover: it was disabled");
return false;
}
if (mPastDhcpLease == null) {
Log.d(TAG, "IP recover: mPastDhcpLease is empty");
return false;
}
Log.d(TAG, "IP recover: mPastDhcpLease = " + mPastDhcpLease);
long reCaculatedLeaseMillis =
mPastDhcpLease.systemExpiredTime - SystemClock.elapsedRealtime();
Log.d(TAG, "IP recover: reCaculatedLeaseMillis = " + reCaculatedLeaseMillis);
if (reCaculatedLeaseMillis < 0) {
// configure infinite lease
mDhcpLeaseExpiry = 0;
Log.e(TAG, "IP recover: lease had been expired! configure to infinite lease");
} else {
mDhcpLeaseExpiry = SystemClock.elapsedRealtime() + reCaculatedLeaseMillis;
Log.d(TAG, "IP recover: mDhcpLeaseExpiry = " + mDhcpLeaseExpiry);
}
byte arpResult[] = null;
ArpPeer ap = null;
boolean retVal = false;
try {
InetAddress ipAddress = mPastDhcpLease.ipAddress.getAddress();
Log.d(TAG, "IP recover: arp address = " +
"#$%K" +
logDumpIpv4(3, ipAddress.getHostAddress()));
ap = new ArpPeer(mIfaceName, Inet4Address.ANY, ipAddress);
// doArp will blocking several seconds, to create thread if needed
arpResult = ap.doArp(5000);
if (arpResult == null) {
int leaseDuration = (int)reCaculatedLeaseMillis/1000;
mPastDhcpLease.setLeaseDuration(leaseDuration);
acceptDhcpResults(mPastDhcpLease, "Confirmed");
Log.d(TAG, "doIpRecover no arp response, IP can be reused");
retVal = true;
} else {
Log.d(TAG, "doIpRecover DAD detected!!");
}
} catch (ErrnoException ee) {
Log.d(TAG, "err :" + ee);
} catch (IllegalArgumentException ie) {
Log.d(TAG, "err :" + ie);
} catch (SocketException se) {
Log.d(TAG, "err :" + se);
} finally {
if (ap != null) ap.close();
}
return retVal;
}
/// @}