diff options
Diffstat (limited to 'src/android')
| -rw-r--r-- | src/android/net/ip/IpClientLinkObserver.java | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/src/android/net/ip/IpClientLinkObserver.java b/src/android/net/ip/IpClientLinkObserver.java index 66a4038..dc58e7b 100644 --- a/src/android/net/ip/IpClientLinkObserver.java +++ b/src/android/net/ip/IpClientLinkObserver.java @@ -282,6 +282,12 @@ public class IpClientLinkObserver implements NetworkObserver { } private final AlarmManager.OnAlarmListener mExpirePref64Alarm = () -> { + // TODO: in the rare case where the alarm fires and posts the lambda to the handler + // thread while we are processing an RA that changes the lifetime of the same prefix, + // this code will run anyway even if the alarm is rescheduled or cancelled. If the + // lifetime in the RA is zero this doesn't matter (we just harmlessly cancel the alarm + // one extra time) but if the lifetime is nonzero then the prefix will be added and + // immediately removed by this code. updatePref64(mShim.getNat64Prefix(mLinkProperties), mNat64PrefixExpiry, mNat64PrefixExpiry); }; @@ -321,9 +327,11 @@ public class IpClientLinkObserver implements NetworkObserver { // If we already have a prefix, continue using it and ignore the new one. Stopping and // restarting clatd is disruptive because it will break existing IPv4 connections. - // TODO: this means that if we receive an RA that adds a new prefix and deletes the old + // Note: this means that if we receive an RA that adds a new prefix and deletes the old // prefix, we might receive and ignore the new prefix, then delete the old prefix, and - // have no prefix until the next RA is received. + // have no prefix until the next RA is received. This is because the kernel returns ND + // user options one at a time even if they are in the same RA. + // TODO: keep track of the last few prefixes seen, like DnsServerRepository does. if (mNat64PrefixExpiry > now) return; // The current prefix has expired. Either replace it with the new one or delete it. |