From 5aa782acc063597252b17d70b91e7005a9cee16c Mon Sep 17 00:00:00 2001
From: Dan Sumorok <dsumorok@gmail.com>
Date: Mon, 27 May 2013 13:55:38 -0400
Subject: [PATCH] Changed ethernet address when using tap interface.

---
 BasiliskII/src/MacOSX/etherslavetool.c |  4 ++--
 BasiliskII/src/Unix/ether_unix.cpp     | 21 ++++++++++++++++-----
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/BasiliskII/src/MacOSX/etherslavetool.c b/BasiliskII/src/MacOSX/etherslavetool.c
index e60c6ce9..baa5b46f 100644
--- a/BasiliskII/src/MacOSX/etherslavetool.c
+++ b/BasiliskII/src/MacOSX/etherslavetool.c
@@ -126,7 +126,7 @@ static int main_loop(int sd, int use_bpf)
                         return -1;
                 }
         } else {
-                blen = 2048;
+                blen = 4096;
         }
 
 	incoming = malloc(blen);
@@ -239,7 +239,7 @@ static int main_loop(int sd, int use_bpf)
 		if (!use_bpf && FD_ISSET(sd, &readSet)) {
 			in_len = (unsigned short *)incoming;
 
-			pkt_len = read(sd, incoming+2, blen-2);
+			pkt_len = read(sd, in_len + 1, blen-2);
 			if (pkt_len < 14) {
 				fret = -8;
 				break;
diff --git a/BasiliskII/src/Unix/ether_unix.cpp b/BasiliskII/src/Unix/ether_unix.cpp
index 947ea080..8e005308 100644
--- a/BasiliskII/src/Unix/ether_unix.cpp
+++ b/BasiliskII/src/Unix/ether_unix.cpp
@@ -1188,11 +1188,22 @@ static bool open_ether_slave(const std::string &if_name)
 		dev_name.erase(pos);
 	}
 
-	if (get_mac_address(dev_name.c_str(), ether_addr) != 0) {
-		snprintf(str, sizeof(str), "Unable to find interface %s.",
-			 dev_name.c_str());
-		WarningAlert(str);
-		return false;
+	if(strncmp(if_name.c_str(), "tap", 3) != 0) {
+		if (get_mac_address(dev_name.c_str(), ether_addr) != 0) {
+			snprintf(str, sizeof(str), "Unable to find interface %s.",
+				 dev_name.c_str());
+			WarningAlert(str);
+			return false;
+		}
+	} else {
+		/* There is something special about this address. */
+		pid_t p = getpid();
+		ether_addr[0] = 0xfe;
+		ether_addr[1] = 0xfd;
+		ether_addr[2] = p >> 24;
+		ether_addr[3] = p >> 16;
+		ether_addr[4] = p >> 8;
+		ether_addr[5] = p;
 	}
 
 	fd = dup(fileno(fp));