# A patch to add complete support for the BIOCSHDRCMPLT ioctl to Mac OS X 
# Jaguar (Darwin).  This is also known as ETHERSPOOF.
# 
# This patch improves the functionality provided in the ETHERSPOOF patch
# by Peter Bartoli.  NOTE: This patch is incompatible with the ETHERSPOOF patch.
#
# Instead of (potentially) altering the source Ethernet address of all 
# AF_UNSPEC packets, this patch only affects packets when the BIOCSHDRCMPLT 
# ioctl is used.  In other words, this won't break dhcp.
#
# apply in the top level xnu-xxx source directory:
# patch -p0 -b --verbose --suffix=.orig < BIOCSHDRCMPLT-jaguar.patch
#
# Then, build the kernel and install it as you normally would.

--- bsd/net/ether_if_module.c.orig	Fri Oct 24 18:25:55 2003
+++ bsd/net/ether_if_module.c	Tue Nov 18 00:14:46 2003
@@ -438,6 +438,8 @@
 	char			*ether_type;
 {
 	register struct ether_header *eh;
+	int hdrcmplt = 0;
+	u_char esrc[6];
 	int hlen;	/* link layer header lenght */
 	struct arpcom *ac = IFP2AC(ifp);
 
@@ -485,12 +487,22 @@
 	}
 
 
+	if (ndest->sa_family == pseudo_AF_HDRCMPLT)
+	{
+		hdrcmplt = 1;
+		eh = (struct ether_header *)ndest->sa_data;
+		memcpy((u_char *)esrc, (u_char *)eh->ether_shost, sizeof(esrc));
+	}
+
 	eh = mtod(*m, struct ether_header *);
 	(void)memcpy(&eh->ether_type, ether_type,
 		sizeof(eh->ether_type));
  	(void)memcpy(eh->ether_dhost, edst, 6);
- 	(void)memcpy(eh->ether_shost, ac->ac_enaddr,
-	    sizeof(eh->ether_shost));
+	if (hdrcmplt)
+ 	    (void)memcpy(eh->ether_shost, esrc, sizeof(eh->ether_shost));
+	else
+ 	    (void)memcpy(eh->ether_shost, ac->ac_enaddr,
+	        sizeof(eh->ether_shost));
 
 	return 0;
 }