Add link-related methods at NetlinkUtils
This CL adds static methods at NetlinkUtils class that send the
netlink message to kernel to configure the network interface up or down,
rename the interface, and query the interface.
Bug: 364501824
Test: NetworkStackIntegrationTests:android.net.ip.IpClientSignatureTest
Change-Id: Ie545a6617adff2601f405df01dea9edd59952a53
diff --git a/staticlibs/device/com/android/net/module/util/netlink/NetlinkUtils.java b/staticlibs/device/com/android/net/module/util/netlink/NetlinkUtils.java
index 541a375..f34159e 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/NetlinkUtils.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/NetlinkUtils.java
@@ -30,6 +30,7 @@
import static android.system.OsConstants.SO_RCVTIMEO;
import static android.system.OsConstants.SO_SNDTIMEO;
+import static com.android.net.module.util.netlink.NetlinkConstants.RTM_NEWLINK;
import static com.android.net.module.util.netlink.NetlinkConstants.hexify;
import static com.android.net.module.util.netlink.NetlinkConstants.NLMSG_DONE;
import static com.android.net.module.util.netlink.NetlinkConstants.RTNL_FAMILY_IP6MR;
@@ -57,6 +58,7 @@
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
+import java.util.concurrent.atomic.AtomicReference;
import java.util.function.Consumer;
/**
@@ -225,6 +227,96 @@
}
/**
+ * Sends an RTM_NEWLINK message to kernel to set a network interface up or down.
+ *
+ * @param ifName The name of the network interface to modify.
+ * @param isUp {@code true} to set the interface up, {@code false} to set it down.
+ * @return {@code true} if the request was successfully sent, {@code false} otherwise.
+ */
+ public static boolean sendRtmSetLinkStateRequest(@NonNull String ifName, boolean isUp) {
+ final RtNetlinkLinkMessage msg = RtNetlinkLinkMessage.createSetLinkStateMessage(
+ ifName, 1 /*sequenceNumber*/, isUp);
+ if (msg == null) {
+ return false;
+ }
+
+ final byte[] bytes = msg.pack(ByteOrder.nativeOrder());
+ try {
+ NetlinkUtils.sendOneShotKernelMessage(NETLINK_ROUTE, bytes);
+ return true;
+ } catch (ErrnoException e) {
+ Log.e(TAG, "Fail to set the interface " + ifName + " " + (isUp ? "up" : "down"), e);
+ return false;
+ }
+ }
+
+ /**
+ * Sends an RTM_NEWLINK message to kernel to rename a network interface.
+ *
+ * @param ifName The current name of the network interface.
+ * @param newIfName The new name to assign to the interface.
+ * @return {@code true} if the request was successfully sent, {@code false} otherwise.
+ */
+ public static boolean sendRtmSetLinkNameRequest(
+ @NonNull String ifName, @NonNull String newIfName) {
+ final RtNetlinkLinkMessage msg = RtNetlinkLinkMessage.createSetLinkNameMessage(
+ ifName, 1 /*sequenceNumber*/, newIfName);
+ if (msg == null) {
+ return false;
+ }
+
+ final byte[] bytes = msg.pack(ByteOrder.nativeOrder());
+ try {
+ NetlinkUtils.sendOneShotKernelMessage(NETLINK_ROUTE, bytes);
+ return true;
+ } catch (ErrnoException e) {
+ Log.e(TAG, "Fail to rename the interface from " + ifName + " to " + newIfName, e);
+ return false;
+ }
+ }
+
+ /**
+ * Gets the information of a network interface using a Netlink message.
+ * <p>
+ * This method sends a Netlink message to the kernel to request information about the specified
+ * network interface and returns a {@link RtNetlinkLinkMessage} containing the interface status.
+ *
+ * @param ifName The name of the network interface to query.
+ * @return An {@link RtNetlinkLinkMessage} containing the interface status, or {@code null} if
+ * the interface does not exist or an error occurred during the query.
+ */
+ @Nullable
+ public static RtNetlinkLinkMessage getLinkRequest(@NonNull String ifName) {
+ final int ifIndex = new OsAccess().if_nametoindex(ifName);
+ if (ifIndex == OsAccess.INVALID_INTERFACE_INDEX) {
+ return null;
+ }
+
+ final AtomicReference<RtNetlinkLinkMessage> recvMsg = new AtomicReference<>();
+ final Consumer<RtNetlinkLinkMessage> handleNlMsg = (msg) -> {
+ if (msg.getHeader().nlmsg_type == RTM_NEWLINK
+ && msg.getIfinfoHeader().index == ifIndex) {
+ recvMsg.set(msg);
+ }
+ };
+
+ final RtNetlinkLinkMessage msg = RtNetlinkLinkMessage.createGetLinkMessage(
+ ifName, 1 /*sequenceNumber*/);
+ if (msg == null) {
+ return null;
+ }
+
+ final byte[] bytes = msg.pack(ByteOrder.nativeOrder());
+ try {
+ NetlinkUtils.getAndProcessNetlinkDumpMessages(
+ bytes, NETLINK_ROUTE, RtNetlinkLinkMessage.class, handleNlMsg);
+ } catch (SocketException | InterruptedIOException | ErrnoException e) {
+ // Nothing we can do here.
+ }
+ return recvMsg.get();
+ }
+
+ /**
* Create netlink socket with the given netlink protocol type and buffersize.
*
* @param nlProto the netlink protocol