From 240575ed1f1d0d177f5b1f156fa28d029841ab4b Mon Sep 17 00:00:00 2001
From: Stephen Soltesz <stephen.soltesz@gmail.com>
Date: Fri, 30 Jun 2023 16:32:09 -0400
Subject: [PATCH] Filter interfaces that are up (#52)

---
 main.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/main.go b/main.go
index 8b89ba4..43dbb3a 100644
--- a/main.go
+++ b/main.go
@@ -94,7 +94,10 @@ func processFlags() ([]net.Interface, error) {
 		if err != nil {
 			return ifaces, err
 		}
-		ifaces = append(ifaces, *i)
+		if i.Flags&net.FlagUp != 0 {
+			// We can only capture packets from interfaces that are up.
+			ifaces = append(ifaces, *i)
+		}
 	}
 	return ifaces, nil
 }