From bb86a878602bd05f91176ed2c3d554ee5a1bf8cc Mon Sep 17 00:00:00 2001
From: Bruno Bodin <bruno.bodin@cea.fr>
Date: Thu, 12 Jan 2017 12:05:52 +0100
Subject: [PATCH] ZSYS_INTERFACE variable can be a single digit

---
 src/zbeacon.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/src/zbeacon.c b/src/zbeacon.c
index b92eff1c4..5c3b1f782 100644
--- a/src/zbeacon.c
+++ b/src/zbeacon.c
@@ -101,6 +101,32 @@ s_self_prepare_udp (self_t *self)
         send_to = INADDR_BROADCAST;
         found_iface = 1;
     }
+    // if ZSYS_INTERFACE is a single digit, use the corresponding interface in
+    // the interface list
+    else if (strlen(iface) == 1 && iface[0] >= '0' && iface[0] <= '9')
+    {
+      int if_number = atoi(iface);
+      ziflist_t *iflist = ziflist_new();
+      assert(iflist);
+      const char *name = ziflist_first(iflist);
+      int idx = -1;
+      while (name) {
+        idx++;
+        if (idx==if_number) {
+          //  Using inet_addr instead of inet_aton or inet_atop
+          //  because these are not supported in Win XP
+          send_to = inet_addr(ziflist_broadcast(iflist));
+          bind_to = inet_addr(ziflist_address(iflist));
+          if (self->verbose)
+            zsys_info("zbeacon: interface=%s address=%s broadcast=%s",
+              name, ziflist_address(iflist), ziflist_broadcast(iflist));
+          found_iface = 1;
+          break;      //  iface is known, so allow it
+        }
+        name = ziflist_next(iflist);
+      }
+      ziflist_destroy(&iflist);
+    }
     else {
         //  Look for matching interface, or first ziflist item
         ziflist_t *iflist = ziflist_new ();