cache getifaddrs - linux

osdep/LinuxEthernetTap.cpp

@@ -126,12 +126,14 @@ LinuxEthernetTap::LinuxEthernetTap(
 	_mtu(mtu),
 	_fd(0),
 	_enabled(true),
-	_run(true)
+	_run(true),
+	_lastIfAddrsUpdate(0)
 {
 	static std::mutex s_tapCreateLock;
 	char procpath[128],nwids[32];
 	struct stat sbuf;
 
+
 	// Create only one tap at a time globally.
 	std::lock_guard<std::mutex> tapCreateLock(s_tapCreateLock);
 
@@ -438,6 +440,14 @@ bool LinuxEthernetTap::removeIp(const InetAddress &ip)
 
 std::vector<InetAddress> LinuxEthernetTap::ips() const
 {
+
+	uint64_t now = OSUtils::now();
+
+	if ((now - _lastIfAddrsUpdate) <= GETIFADDRS_CACHE_TIME) {
+		return _ifaddrs;
+	}
+	_lastIfAddrsUpdate = now;
+
 	struct ifaddrs *ifa = (struct ifaddrs *)0;
 	if (getifaddrs(&ifa))
 		return std::vector<InetAddress>();
@@ -471,6 +481,8 @@ std::vector<InetAddress> LinuxEthernetTap::ips() const
 	std::sort(r.begin(),r.end());
 	r.erase(std::unique(r.begin(),r.end()),r.end());
 
+	_ifaddrs = r;
+
 	return r;
 }
 

osdep/LinuxEthernetTap.hpp

@@ -57,6 +57,9 @@ public:
 	virtual void setMtu(unsigned int mtu);
 	virtual void setDns(const char *domain, const std::vector<InetAddress> &servers) {}
 
+
+
+
 private:
 	void (*_handler)(void *,void *,uint64_t,const MAC &,const MAC &,unsigned int,unsigned int,const void *,unsigned int);
 	void *_arg;
@@ -71,6 +74,8 @@ private:
 	std::atomic_bool _enabled;
 	std::atomic_bool _run;
 	std::thread _tapReaderThread;
+	mutable std::vector<InetAddress> _ifaddrs;
+	mutable uint64_t _lastIfAddrsUpdate;
 };
 
 } // namespace ZeroTier