NetworkStats - no need for xt_qtaguid clat bw fixups am: d1dd2f9cf3 (df27973f) · Commits · e / os / android_frameworks_base

core/java/android/net/NetworkStats.java

+26 −38

Original line number	Original line	Diff line number	Diff line
	@@ -1047,22 +1047,22 @@ public final class NetworkStats implements Parcelable {
	}		}

	/**		/**
	* Calculate and apply adjustments to captured statistics for 464xlat traffic counted twice.		* Calculate and apply adjustments to captured statistics for 464xlat traffic.
			*
			* <p>This mutates stacked traffic stats, to account for IPv4/IPv6 header size difference.
	*		*
	* <p>This mutates both base and stacked traffic stats, to account respectively for		* <p>UID stats, which are only accounted on the stacked interface, need to be increased
	* double-counted traffic and IPv4/IPv6 header size difference.		* by 20 bytes/packet to account for translation overhead.
	*		*
	* <p>For 464xlat traffic, xt_qtaguid sees every IPv4 packet twice, once as a native IPv4		* <p>The potential additional overhead of 8 bytes/packet for ip fragments is ignored.
	* packet on the stacked interface, and once as translated to an IPv6 packet on the
	* base interface. For correct stats accounting on the base interface, if using xt_qtaguid,
	* every rx 464xlat packet needs to be subtracted from the root UID on the base interface
	* (http://b/12249687, http:/b/33681750), and every tx 464xlat packet which was counted onto
	* clat uid should be ignored.
	*		*
	* As for eBPF, the per uid stats is collected by different hook, the rx packets on base		* <p>Interface stats need to sum traffic on both stacked and base interface because:
	* interface will not be counted. Thus, the adjustment on root uid is not needed. However, the		* - eBPF offloaded packets appear only on the stacked interface
	* tx traffic counted in the same way xt_qtaguid does, so the traffic on clat uid still		* - Non-offloaded ingress packets appear only on the stacked interface
	* needs to be ignored.		* (due to iptables raw PREROUTING drop rules)
			* - Non-offloaded egress packets appear only on the stacked interface
			* (due to ignoring traffic from clat daemon by uid match)
			* (and of course the 20 bytes/packet overhead needs to be applied to stacked interface stats)
	*		*
	* <p>This method will behave fine if {@code stackedIfaces} is an non-synchronized but add-only		* <p>This method will behave fine if {@code stackedIfaces} is an non-synchronized but add-only
	* {@code ConcurrentHashMap}		* {@code ConcurrentHashMap}
	@@ -1074,46 +1074,34 @@ public final class NetworkStats implements Parcelable {
	*/		*/
	public static void apply464xlatAdjustments(NetworkStats baseTraffic,		public static void apply464xlatAdjustments(NetworkStats baseTraffic,
	NetworkStats stackedTraffic, Map<String, String> stackedIfaces, boolean useBpfStats) {		NetworkStats stackedTraffic, Map<String, String> stackedIfaces, boolean useBpfStats) {
	// Total 464xlat traffic to subtract from uid 0 on all base interfaces.
	// stackedIfaces may grow afterwards, but NetworkStats will just be resized automatically.
	final NetworkStats adjustments = new NetworkStats(0, stackedIfaces.size());

	// For recycling		// For recycling
	Entry entry = null;		Entry entry = null;
	Entry adjust = new NetworkStats.Entry(IFACE_ALL, 0, 0, 0, 0, 0, 0, 0L, 0L, 0L, 0L, 0L);

	for (int i = 0; i < stackedTraffic.size; i++) {		for (int i = 0; i < stackedTraffic.size; i++) {
	entry = stackedTraffic.getValues(i, entry);		entry = stackedTraffic.getValues(i, entry);
	if (entry.iface == null \|\| !entry.iface.startsWith(CLATD_INTERFACE_PREFIX)) {		if (entry == null) continue;
	continue;		if (entry.iface == null) continue;
	}		if (!entry.iface.startsWith(CLATD_INTERFACE_PREFIX)) continue;
	final String baseIface = stackedIfaces.get(entry.iface);
	if (baseIface == null) {
	continue;
	}
	// Subtract xt_qtaguid 464lat rx traffic seen for the root UID on the current base
	// interface. As for eBPF, the per uid stats is collected by different hook, the rx
	// packets on base interface will not be counted.
	adjust.iface = baseIface;
	if (!useBpfStats) {
	adjust.rxBytes = -(entry.rxBytes + entry.rxPackets * IPV4V6_HEADER_DELTA);
	adjust.rxPackets = -entry.rxPackets;
	}
	adjustments.combineValues(adjust);

	// For 464xlat traffic, per uid stats only counts the bytes of the native IPv4 packet		// For 464xlat traffic, per uid stats only counts the bytes of the native IPv4 packet
	// sent on the stacked interface with prefix "v4-" and drops the IPv6 header size after		// sent on the stacked interface with prefix "v4-" and drops the IPv6 header size after
	// unwrapping. To account correctly for on-the-wire traffic, add the 20 additional bytes		// unwrapping. To account correctly for on-the-wire traffic, add the 20 additional bytes
	// difference for all packets (http://b/12249687, http:/b/33681750).		// difference for all packets (http://b/12249687, http:/b/33681750).
			//
			// Note: this doesn't account for LRO/GRO/GSO/TSO (ie. >mtu) traffic correctly, nor
			// does it correctly account for the 8 extra bytes in the IPv6 fragmentation header.
			//
			// While the ebpf code path does try to simulate proper post segmentation packet
			// counts, we have nothing of the sort of xt_qtaguid stats.
	entry.rxBytes += entry.rxPackets * IPV4V6_HEADER_DELTA;		entry.rxBytes += entry.rxPackets * IPV4V6_HEADER_DELTA;
	entry.txBytes += entry.txPackets * IPV4V6_HEADER_DELTA;		entry.txBytes += entry.txPackets * IPV4V6_HEADER_DELTA;
	stackedTraffic.setValues(i, entry);		stackedTraffic.setValues(i, entry);
	}		}

	// Traffic on clat uid is v6 tx traffic that is already counted with app uid on the stacked		// Theoretically there should be no traffic accounted to the clat daemon's uid:
	// v4 interface, so it needs to be removed to avoid double-counting.		// see ebpf program 'netd.c's early returns
			// and iptables '-m owner --uid-owner clat -j RETURN' rules prior to accounting
			// TODO: remove this - should definitely be safe once ebpf only.
	baseTraffic.removeUids(new int[] {CLAT_UID});		baseTraffic.removeUids(new int[] {CLAT_UID});
	baseTraffic.combineAllValues(adjustments);
	}		}

	/**		/**