Include iface index in the netlink event

The TrafficController inside netd also get notified when the interface
on device added or removed, and it need both ifaceName and ifaceIndex
information from Netlink event. Add the ifaceIndex in the event can
avoid the TrafficController to run if_nametoindex again when receive
the event.

Bug: 30950746
Bug: 73137611
Test: new interface show up in bpf interface map.
Change-Id: Ia3b4aeb8eff345ce7cf03ccec88f0893cfe125c0
diff --git a/libsysutils/src/NetlinkEvent.cpp b/libsysutils/src/NetlinkEvent.cpp
index 7f92904..35a3063 100644
--- a/libsysutils/src/NetlinkEvent.cpp
+++ b/libsysutils/src/NetlinkEvent.cpp
@@ -137,6 +137,12 @@
         switch(rta->rta_type) {
             case IFLA_IFNAME:
                 asprintf(&mParams[0], "INTERFACE=%s", (char *) RTA_DATA(rta));
+                // We can get the interface change information from sysfs update
+                // already. But in case we missed those message when devices start.
+                // We do a update again when received a kLinkUp event. To make
+                // the message consistent, use IFINDEX here as well since sysfs
+                // uses IFINDEX.
+                asprintf(&mParams[1], "IFINDEX=%d", ifi->ifi_index);
                 mAction = (ifi->ifi_flags & IFF_LOWER_UP) ? Action::kLinkUp :
                                                             Action::kLinkDown;
                 mSubsystem = strdup("net");