Added `ds', a black-hole network interface.

1 files changed, 220 insertions, 0 deletions

diff --git a/sys/net/if_disc.c b/sys/net/if_disc.c
new file mode 100644
index 0000000..a6031dd
--- /dev/null
+++ b/sys/net/if_disc.c
@@ -0,0 +1,220 @@
+/*
+ * Copyright (c) 1982, 1986, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	From: @(#)if_loop.c	8.1 (Berkeley) 6/10/93
+ *	$Id: if_loop.c,v 1.6 1994/08/08 12:07:25 davidg Exp $
+ */
+
+/*
+ * Discard interface driver for protocol testing and timing.
+ * (Based on the loopback.)
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/errno.h>
+#include <sys/ioctl.h>
+#include <sys/time.h>
+#include <machine/cpu.h>
+
+#include <net/if.h>
+#include <net/if_types.h>
+#include <net/netisr.h>
+#include <net/route.h>
+#include <net/bpf.h>
+
+#ifdef	INET
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/in_var.h>
+#include <netinet/ip.h>
+#endif
+
+#ifdef NS
+#include <netns/ns.h>
+#include <netns/ns_if.h>
+#endif
+
+#ifdef ISO
+#include <netiso/iso.h>
+#include <netiso/iso_var.h>
+#endif
+
+#include "bpfilter.h"
+
+#ifdef TINY_DSMTU
+#define	DSMTU	(1024+512)
+#else
+#define DSMTU	65532
+#endif
+
+static struct	ifnet dsif;
+static int dsoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
+		    struct rtentry *);
+static int dsioctl(struct ifnet *, int, caddr_t);
+
+/* ARGSUSED */
+static void
+discattach(void)
+{
+	register struct ifnet *ifp = &dsif;
+
+	ifp->if_name = "ds";
+	ifp->if_mtu = DSMTU;
+	ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
+	ifp->if_ioctl = dsioctl;
+	ifp->if_output = dsoutput;
+	ifp->if_type = IFT_LOOP;
+	ifp->if_hdrlen = 0;
+	ifp->if_addrlen = 0;
+	if_attach(ifp);
+#if NBPFILTER > 0
+	bpfattach(&ifp->if_bpf, ifp, DLT_NULL, sizeof(u_int));
+#endif
+}
+
+TEXT_SET(pseudo_set, discattach);
+
+static int
+dsoutput(ifp, m, dst, rt)
+	struct ifnet *ifp;
+	register struct mbuf *m;
+	struct sockaddr *dst;
+	register struct rtentry *rt;
+{
+	int s, isr;
+	register struct ifqueue *ifq = 0;
+
+	if ((m->m_flags & M_PKTHDR) == 0)
+		panic("dsoutput no HDR");
+	ifp->if_lastchange = time;
+#if NBPFILTER > 0
+	if (dsif.if_bpf) {
+		/*
+		 * 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;
+		u_int af = dst->sa_family;
+
+		m0.m_next = m;
+		m0.m_len = 4;
+		m0.m_data = (char *)&af;
+		
+		bpf_mtap(dsif.if_bpf, &m0);
+	}
+#endif
+	m->m_pkthdr.rcvif = ifp;
+
+	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
+		m_freem(m);
+		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
+		        rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
+	}
+	ifp->if_opackets++;
+	ifp->if_obytes += m->m_pkthdr.len;
+
+	m_freem(m);
+	return 0;
+}
+
+/* ARGSUSED */
+static void
+dsrtrequest(cmd, rt, sa)
+	int cmd;
+	struct rtentry *rt;
+	struct sockaddr *sa;
+{
+	if (rt)
+		rt->rt_rmx.rmx_mtu = DSMTU;
+}
+
+/*
+ * Process an ioctl request.
+ */
+/* ARGSUSED */
+int
+dsioctl(ifp, cmd, data)
+	register struct ifnet *ifp;
+	int 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 = dsrtrequest;
+		/*
+		 * 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
+
+		default:
+			error = EAFNOSUPPORT;
+			break;
+		}
+		break;
+
+	case SIOCSIFMTU:
+		ifp->if_mtu = ifr->ifr_mtu;
+		break;
+
+	default:
+		error = EINVAL;
+	}
+	return (error);
+}