From f789a3bab755850d22335f292766ea9c051ed45b Mon Sep 17 00:00:00 2001
From: Thomas Bernard <miniupnp@free.fr>
Date: Fri, 11 Apr 2014 00:03:13 +0200
Subject: [PATCH] miniupnpd/getifaddr.c: check if interface is up

---
 miniupnpd/getifaddr.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/miniupnpd/getifaddr.c b/miniupnpd/getifaddr.c
index be57050..f9e2c6d 100644
--- a/miniupnpd/getifaddr.c
+++ b/miniupnpd/getifaddr.c
@@ -47,6 +47,19 @@ getifaddr(const char * ifname, char * buf, int len,
 		return -1;
 	}
 	strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
+	if(ioctl(s, SIOCGIFFLAGS, &ifr, &ifrlen) < 0)
+	{
+		syslog(LOG_DEBUG, "ioctl(s, SIOCGIFFLAGS, ...): %m");
+		close(s);
+		return -1;
+	}
+	if ((ifr.ifr_flags & IFF_UP) == 0)
+	{
+		syslog(LOG_DEBUG, "network interface %s is down", ifname);
+		close(s);
+		return -1;
+	}
+	strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
 	if(ioctl(s, SIOCGIFADDR, &ifr, &ifrlen) < 0)
 	{
 		syslog(LOG_ERR, "ioctl(s, SIOCGIFADDR, ...): %m");