1/*
2 * Copyright (c) 1982, 1986, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * From: @(#)if_loop.c 8.1 (Berkeley) 6/10/93
34 * $FreeBSD: head/sys/net/if_disc.c 54263 1999-12-07 17:39:16Z shin $
35 */
36
37/*
38 * Discard interface driver for protocol testing and timing.
39 * (Based on the loopback.)
40 */
41
42#include <sys/param.h>
43#include <sys/systm.h>
44#include <sys/kernel.h>
45#include <sys/mbuf.h>
46#include <sys/socket.h>
47#include <sys/sockio.h>
48
49#include <net/if.h>
50#include <net/if_types.h>
51#include <net/route.h>
52#include <net/bpf.h>
53
54#include "opt_inet.h"
55#include "opt_inet6.h"
56
57#ifdef TINY_DSMTU
58#define DSMTU (1024+512)
59#else
60#define DSMTU 65532
61#endif
62
63static void discattach __P((void *dummy));
64PSEUDO_SET(discattach, if_disc);
65
66static struct ifnet discif;
67static int discoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
68 struct rtentry *);
69static void discrtrequest(int cmd, struct rtentry *rt, struct sockaddr *sa);
70static int discioctl(struct ifnet *, u_long, caddr_t);
71
72/* ARGSUSED */
73static void
74discattach(dummy)
75 void *dummy;
76{
77 register struct ifnet *ifp = &discif;
78
79 ifp->if_name = "ds";
80 ifp->if_mtu = DSMTU;
81 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
82 ifp->if_ioctl = discioctl;
83 ifp->if_output = discoutput;
84 ifp->if_type = IFT_LOOP;
85 ifp->if_hdrlen = 0;
86 ifp->if_addrlen = 0;
87 ifp->if_snd.ifq_maxlen = 20;
88 if_attach(ifp);
89 bpfattach(ifp, DLT_NULL, sizeof(u_int));
90}
91
92static int
93discoutput(ifp, m, dst, rt)
94 struct ifnet *ifp;
95 register struct mbuf *m;
96 struct sockaddr *dst;
97 register struct rtentry *rt;
98{
99 if ((m->m_flags & M_PKTHDR) == 0)
100 panic("discoutput no HDR");
101 /* BPF write needs to be handled specially */
102 if (dst->sa_family == AF_UNSPEC) {
103 dst->sa_family = *(mtod(m, int *));
104 m->m_len -= sizeof(int);
105 m->m_pkthdr.len -= sizeof(int);
106 m->m_data += sizeof(int);
107 }
108
109 if (discif.if_bpf) {
110 /*
111 * We need to prepend the address family as
112 * a four byte field. Cons up a dummy header
113 * to pacify bpf. This is safe because bpf
114 * will only read from the mbuf (i.e., it won't
115 * try to free it or keep a pointer a to it).
116 */
117 struct mbuf m0;
118 u_int af = dst->sa_family;
119
120 m0.m_next = m;
121 m0.m_len = 4;
122 m0.m_data = (char *)&af;
123
124 bpf_mtap(&discif, &m0);
125 }
126 m->m_pkthdr.rcvif = ifp;
127
128 ifp->if_opackets++;
129 ifp->if_obytes += m->m_pkthdr.len;
130
131 m_freem(m);
132 return 0;
133}
134
135/* ARGSUSED */
136static void
137discrtrequest(cmd, rt, sa)
138 int cmd;
139 struct rtentry *rt;
140 struct sockaddr *sa;
141{
142 if (rt)
143 rt->rt_rmx.rmx_mtu = DSMTU;
144}
145
146/*
147 * Process an ioctl request.
148 */
149/* ARGSUSED */
150static int
151discioctl(ifp, cmd, data)
152 register struct ifnet *ifp;
153 u_long cmd;
154 caddr_t data;
155{
156 register struct ifaddr *ifa;
157 register struct ifreq *ifr = (struct ifreq *)data;
158 register int error = 0;
159
160 switch (cmd) {
161
162 case SIOCSIFADDR:
163 ifp->if_flags |= IFF_UP;
164 ifa = (struct ifaddr *)data;
165 if (ifa != 0)
166 ifa->ifa_rtrequest = discrtrequest;
167 /*
168 * Everything else is done at a higher level.
169 */
170 break;
171
172 case SIOCADDMULTI:
173 case SIOCDELMULTI:
174 if (ifr == 0) {
175 error = EAFNOSUPPORT; /* XXX */
176 break;
177 }
178 switch (ifr->ifr_addr.sa_family) {
179
180#ifdef INET
181 case AF_INET:
182 break;
183#endif
184#ifdef INET6
185 case AF_INET6:
186 break;
187#endif
188
189 default:
190 error = EAFNOSUPPORT;
191 break;
192 }
193 break;
194
195 case SIOCSIFMTU:
196 ifp->if_mtu = ifr->ifr_mtu;
197 break;
198
199 default:
200 error = EINVAL;
201 }
202 return (error);
203}