InterfaceController::setBaseReachableTimeMs()

Add an InterfaceController::setBaseReachableTimeMs() method to set
the ARP/ND default reachable time, as configured in:

     /proc/sys/net/ipv4/{interface}/base_reachable_time_ms
     /proc/sys/net/ipv6/{interface}/base_reachable_time_ms

Bug: 18581716
Change-Id: Idc652e81396d81efe0f08bb1d6dc38bc8e554a56

1 files changed, 13 insertions, 0 deletions

diff --git a/server/InterfaceController.cpp b/server/InterfaceController.cpp
index 373bfd0c..640bf8c6 100644
--- a/server/InterfaceController.cpp
+++ b/server/InterfaceController.cpp
@@ -34,6 +34,10 @@ namespace {
 
 const char ipv6_proc_path[] = "/proc/sys/net/ipv6/conf";
 
+const char ipv4_neigh_conf_dir[] = "/proc/sys/net/ipv4/neigh";
+
+const char ipv6_neigh_conf_dir[] = "/proc/sys/net/ipv6/neigh";
+
 const char sys_net_path[] = "/sys/class/net";
 
 const char wl_util_path[] = "/system/xbin/wlutil";
@@ -86,6 +90,9 @@ InterfaceController::InterfaceController() {
 
 	// Enable optimistic DAD for IPv6 addresses on all interfaces.
 	setIPv6OptimisticMode("1");
+
+	// Reduce the ARP/ND base reachable time from the default (30sec) to 15sec.
+	setBaseReachableTimeMs(15 * 1000);
 }
 
 InterfaceController::~InterfaceController() {
@@ -160,6 +167,12 @@ int InterfaceController::setMtu(const char *interface, const char *mtu)
     return writeValueToPath(sys_net_path, interface, "mtu", mtu);
 }
 
+void InterfaceController::setBaseReachableTimeMs(unsigned int millis) {
+    std::string value(StringPrintf("%u", millis));
+    setOnAllInterfaces(ipv4_neigh_conf_dir, "base_reachable_time_ms", value.c_str());
+    setOnAllInterfaces(ipv6_neigh_conf_dir, "base_reachable_time_ms", value.c_str());
+}
+
 void InterfaceController::setIPv6OptimisticMode(const char *value) {
     setOnAllInterfaces(ipv6_proc_path, "optimistic_dad", value);
     setOnAllInterfaces(ipv6_proc_path, "use_optimistic", value);