--- /home/orly/src/sys/netinet/ip_dummynet.c	Mon Feb  9 12:48:06 2004
+++ ip_dummynet.c	Thu Mar 11 16:13:25 2004
@@ -70,10 +70,13 @@
 #include <sys/proc.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
+#include <sys/sockio.h>
 #include <sys/time.h>
 #include <sys/sysctl.h>
 #include <net/if.h>
+#include <net/if_types.h>
 #include <net/route.h>
+#include <net/bpf.h>
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
 #include <netinet/in_var.h>
@@ -132,6 +135,18 @@
 
 static struct callout_handle dn_timeout;
 
+/*
+ * Statics for Dummynet Discard Interface
+ */
+static void ddattach __P((void));
+static void dddetach __P((void));
+static struct  ifnet ddif;
+static int ddoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
+		    struct rtentry *);
+static void ddrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info);
+static int ddioctl(struct ifnet *, u_long, caddr_t);
+#define DDMTU 65536
+
 #ifdef SYSCTL_NODE
 SYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet,
 		CTLFLAG_RW, 0, "Dummynet");
@@ -1194,16 +1209,16 @@
     q->tot_bytes += len ;
     q->tot_pkts++ ;
     if ( fs->plr && random() < fs->plr )
-	goto dropit ;		/* random pkt drop			*/
+	goto bpf_dropit ;	/* random pkt drop			*/
     if ( fs->flags_fs & DN_QSIZE_IS_BYTES) {
     	if (q->len_bytes > fs->qsize)
-	    goto dropit ;	/* queue size overflow			*/
+	    goto bpf_dropit ;	/* queue size overflow			*/
     } else {
 	if (q->len >= fs->qsize)
-	    goto dropit ;	/* queue count overflow			*/
+	    goto bpf_dropit ;	/* queue count overflow			*/
     }
     if ( fs->flags_fs & DN_IS_RED && red_drops(fs, q, len) )
-	goto dropit ;
+	goto bpf_dropit ;
 
     /* XXX expensive to zero, see if we can remove it*/
     pkt = (struct dn_pkt *)malloc(sizeof (*pkt), M_DUMMYNET, M_NOWAIT|M_ZERO);
@@ -1328,6 +1343,55 @@
     splx(s);
     return 0;
 
+bpf_dropit:
+    if(ddif.if_bpf != NULL) {
+    	/*
+    	* We need to prepend the address family as
+    	* a four byte field.  Cons up a dummy header
+    	* to pacify bpf.  This is safe because bpf
+    	* will only read from the mbuf (i.e., it won't
+    	* try to free it or keep a pointer a to it).
+    	*/
+    	struct mbuf m0;
+	struct ip *ip;
+	struct ether_header *eh;
+    	u_int af;
+
+	switch (dir) {
+	case DN_TO_IP_OUT:
+	case DN_TO_IP_IN:
+		af = AF_INET;
+		ip = mtod(m, struct ip *);
+		ip->ip_len = htons(ip->ip_len);
+		ip->ip_off = htons(ip->ip_off);
+		break;
+	case DN_TO_BDG_FWD:
+	case DN_TO_ETH_DEMUX:
+	case DN_TO_ETH_OUT:
+		eh = mtod(m, struct ether_header *);
+		switch (ntohs(eh->ether_type)) {
+		case ETHERTYPE_IP:
+			af = AF_INET;
+			break;
+		case ETHERTYPE_IPV6:
+			af = AF_INET6;
+			break;
+		}
+		m->m_data += sizeof(struct ether_header);
+		m->m_len -= sizeof(struct ether_header);
+		m->m_pkthdr.len -= sizeof(struct ether_header);
+		break;
+	default:
+		goto dropit;
+	}
+
+    	m0.m_next = m;
+    	m0.m_len = 4;
+    	m0.m_data = (char *)&af;
+
+    	bpf_mtap(&ddif, &m0);
+    }
+
 dropit:
     splx(s);
     if (q)
@@ -1343,7 +1407,6 @@
 #define DN_FREE_PKT(pkt)	{		\
 	struct dn_pkt *n = pkt ;		\
 	rt_unref ( n->ip6opt.ro_or.ro_rt ); /* XXX */	\
-	rt_unref ( n->ro.ro_rt ) ;		\
 	m_freem(n->dn_m);			\
 	pkt = DN_NEXT(n) ;			\
 	free(n, M_DUMMYNET) ;	}
@@ -2036,6 +2099,7 @@
 		    return EEXIST ;
 		}
 		ip_dn_init();
+		ddattach();  /* load dd module */
 		splx(s);
 		break;
 
@@ -2050,6 +2114,7 @@
 		ip_dn_ctl_ptr = NULL;
 		ip_dn_io_ptr = NULL;
 		ip_dn_ruledel_ptr = NULL;
+		dddetach();	/* unload dd interface */
 		splx(s);
 #endif
 		break ;
@@ -2067,3 +2132,111 @@
 DECLARE_MODULE(dummynet, dummynet_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 MODULE_DEPEND(dummynet, ipfw, 1, 1, 1);
 MODULE_VERSION(dummynet, 1);
+
+/* Attach the "Dummynet Discard" Interface */
+static void
+ddattach()
+{
+        register struct ifnet *ifp = &ddif;
+
+        ifp->if_name = "dd";
+        ifp->if_mtu = DDMTU;
+        ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
+        ifp->if_ioctl = ddioctl;
+        ifp->if_output = ddoutput;
+        ifp->if_type = IFT_LOOP;
+        ifp->if_hdrlen = 0;
+        ifp->if_addrlen = 0;
+        ifp->if_snd.ifq_maxlen = 20;
+        if_attach(ifp);
+        bpfattach(ifp, DLT_NULL, sizeof(u_int));
+}
+
+/* Detach the "Dummynet Discard" Interface */
+static void
+dddetach()
+{
+	register struct ifnet *ifp = &ddif;
+
+	bpfdetach(ifp);
+	if_detach(ifp);
+}
+
+static int
+ddoutput(ifp, m, dst, rt)
+        struct ifnet *ifp;
+        register struct mbuf *m;
+        struct sockaddr *dst;
+        register struct rtentry *rt;
+
+{
+        m_freem(m);
+        return 0;
+
+}
+
+static void
+ddrtrequest(cmd, rt, info)
+	int cmd;
+	struct rtentry *rt;
+	struct rt_addrinfo *info;
+{
+	if (rt)
+		rt->rt_rmx.rmx_mtu = DDMTU;
+}
+
+
+static int
+ddioctl(ifp, cmd, data)
+	register struct ifnet *ifp;
+	u_long cmd;
+	caddr_t data;
+{
+	register struct ifaddr *ifa;
+	register struct ifreq *ifr = (struct ifreq *)data;
+	register int error = 0;
+
+	switch (cmd) {
+
+	case SIOCSIFADDR:
+		ifp->if_flags |= IFF_UP;
+		ifa = (struct ifaddr *)data;
+		if (ifa != 0)
+			ifa->ifa_rtrequest = ddrtrequest;
+		/*
+		 * Everything else is done at a higher level.
+		 */
+		break;
+
+	case SIOCADDMULTI:
+	case SIOCDELMULTI:
+		if (ifr == 0) {
+			error = EAFNOSUPPORT;		/* XXX */
+			break;
+		}
+		switch (ifr->ifr_addr.sa_family) {
+
+#ifdef INET
+		case AF_INET:
+			break;
+#endif
+#ifdef INET6
+		case AF_INET6:
+			break;
+#endif
+
+		default:
+			error = EAFNOSUPPORT;
+			break;
+		}
+		break;
+
+	case SIOCSIFMTU:
+		ifp->if_mtu = ifr->ifr_mtu;
+		break;
+
+	default:
+		error = EINVAL;
+	}
+	return (error);
+}