From b75943d2e69db29dd5a8fc5bc1902f755c2a97f3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juhani=20Krekel=C3=A4?= <juhani@krekelä.fi>
Date: Sat, 6 Jul 2019 20:41:31 +0300
Subject: [PATCH] Act only on stuff directed at us or broadcast

---
 ethermess.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/ethermess.c b/ethermess.c
index 112090f..50194f9 100644
--- a/ethermess.c
+++ b/ethermess.c
@@ -71,13 +71,23 @@ void read_command(void) {
 
 void process_frame(void) {
 	unsigned char frame[1518]; // Largest a 802.3 frame can be without FCS
+	unsigned char broadcast_addr[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 
 	errno = 0;
 	if (recv(packet_socket, frame, sizeof(frame), 0) == -1) {
 		errx(1, "recv");
 	}
 
-	fprintf(stderr, "."); // debg
+	if (memcmp(frame, own_mac, sizeof(own_mac)) == 0) {
+		// Targetted at us
+		fprintf(stderr, "."); // debg
+	} else if (memcmp(frame, broadcast_addr, sizeof(broadcast_addr)) == 0) {
+		// Broadcast
+		fprintf(stderr, "^"); // debg
+	} else {
+		// No concern
+		return;
+	}
 }
 
 void eventloop(void) {