Adding non-tracking mode support to AddressTracker.

net/base/address_tracker_linux.cc

Index: net/base/address_tracker_linux.cc
diff --git a/net/base/address_tracker_linux.cc b/net/base/address_tracker_linux.cc
index 367381366954f3280e9171f5d93405f05ed667d7..afed4d56fa674a40ebf2ae9f25362d0f75abda3f 100644
--- a/net/base/address_tracker_linux.cc
+++ b/net/base/address_tracker_linux.cc
@@ -116,7 +116,7 @@ AddressTrackerLinux::~AddressTrackerLinux() {
   CloseSocket();
 }
 
-void AddressTrackerLinux::Init() {
+void AddressTrackerLinux::Init(bool track) {
   netlink_fd_ = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
   if (netlink_fd_ < 0) {
     PLOG(ERROR) << "Could not create NETLINK socket";
@@ -124,20 +124,24 @@ void AddressTrackerLinux::Init() {
     return;
   }
 
-  // Request notifications.
-  struct sockaddr_nl addr = {};
-  addr.nl_family = AF_NETLINK;
-  addr.nl_pid = getpid();
-  // TODO(szym): Track RTMGRP_LINK as well for ifi_type, http://crbug.com/113993
-  addr.nl_groups = RTMGRP_IPV4_IFADDR | RTMGRP_IPV6_IFADDR | RTMGRP_NOTIFY |
-      RTMGRP_LINK;
-  int rv = bind(netlink_fd_,
-                reinterpret_cast<struct sockaddr*>(&addr),
-                sizeof(addr));
-  if (rv < 0) {
-    PLOG(ERROR) << "Could not bind NETLINK socket";
-    AbortAndForceOnline();
-    return;
+  int rv;
+
+  if (track) {
+    // Request notifications.
+    struct sockaddr_nl addr = {};
+    addr.nl_family = AF_NETLINK;
+    addr.nl_pid = getpid();
+    // TODO(szym): Track RTMGRP_LINK as well for ifi_type,
+    // http://crbug.com/113993
+    addr.nl_groups =
+        RTMGRP_IPV4_IFADDR | RTMGRP_IPV6_IFADDR | RTMGRP_NOTIFY | RTMGRP_LINK;
+    rv = bind(
+        netlink_fd_, reinterpret_cast<struct sockaddr*>(&addr), sizeof(addr));
+    if (rv < 0) {
+      PLOG(ERROR) << "Could not bind NETLINK socket";
+      AbortAndForceOnline();
+      return;
+    }
   }
 
   // Request dump of addresses.
@@ -191,12 +195,14 @@ void AddressTrackerLinux::Init() {
     is_offline_initialized_cv_.Signal();
   }
 
-  rv = base::MessageLoopForIO::current()->WatchFileDescriptor(
-      netlink_fd_, true, base::MessageLoopForIO::WATCH_READ, &watcher_, this);
-  if (rv < 0) {
-    PLOG(ERROR) << "Could not watch NETLINK socket";
-    AbortAndForceOnline();
-    return;
+  if (track) {
+    rv = base::MessageLoopForIO::current()->WatchFileDescriptor(
+        netlink_fd_, true, base::MessageLoopForIO::WATCH_READ, &watcher_, this);
+    if (rv < 0) {
+      PLOG(ERROR) << "Could not watch NETLINK socket";
+      AbortAndForceOnline();
+      return;
+    }
   }
 }
 
@@ -213,6 +219,11 @@ AddressTrackerLinux::AddressMap AddressTrackerLinux::GetAddressMap() const {
   return address_map_;
 }
 
+base::hash_set<int> AddressTrackerLinux::GetOnlineLinks() const {
+  base::AutoLock lock(online_links_lock_);
+  return online_links_;
+}
+
 NetworkChangeNotifier::ConnectionType
 AddressTrackerLinux::GetCurrentConnectionType() {
   // http://crbug.com/125097
@@ -254,10 +265,15 @@ void AddressTrackerLinux::ReadMessages(bool* address_changed,
       return;
     }
     HandleMessage(buffer, rv, address_changed, link_changed, tunnel_changed);
-  };
+  }
   if (*link_changed) {
+    bool is_offline;
+    {
+      base::AutoLock lock(online_links_lock_);
+      is_offline = online_links_.empty();
+    }
     base::AutoLock lock(is_offline_lock_);
-    is_offline_ = online_links_.empty();
+    is_offline_ = is_offline;
   }
 }
 
@@ -319,12 +335,14 @@ void AddressTrackerLinux::HandleMessage(char* buffer,
             reinterpret_cast<struct ifinfomsg*>(NLMSG_DATA(header));
         if (!(msg->ifi_flags & IFF_LOOPBACK) && (msg->ifi_flags & IFF_UP) &&
             (msg->ifi_flags & IFF_LOWER_UP) && (msg->ifi_flags & IFF_RUNNING)) {
+          base::AutoLock lock(online_links_lock_);
           if (online_links_.insert(msg->ifi_index).second) {
             *link_changed = true;
             if (IsTunnelInterface(msg))
               *tunnel_changed = true;
           }
         } else {
+          base::AutoLock lock(online_links_lock_);
           if (online_links_.erase(msg->ifi_index)) {
             *link_changed = true;
             if (IsTunnelInterface(msg))
@@ -335,6 +353,7 @@ void AddressTrackerLinux::HandleMessage(char* buffer,
       case RTM_DELLINK: {
         const struct ifinfomsg* msg =
             reinterpret_cast<struct ifinfomsg*>(NLMSG_DATA(header));
+        base::AutoLock lock(online_links_lock_);
         if (online_links_.erase(msg->ifi_index)) {
           *link_changed = true;
           if (IsTunnelInterface(msg))