xref: /freebsd/sys/net/if_disc.c (revision 17ee9d00bc1ae1e598c38f25826f861e4bc6c3ce)
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  *	$Id: if_loop.c,v 1.6 1994/08/08 12:07:25 davidg Exp $
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/errno.h>
48 #include <sys/ioctl.h>
49 #include <sys/time.h>
50 #include <machine/cpu.h>
51 
52 #include <net/if.h>
53 #include <net/if_types.h>
54 #include <net/netisr.h>
55 #include <net/route.h>
56 #include <net/bpf.h>
57 
58 #ifdef	INET
59 #include <netinet/in.h>
60 #include <netinet/in_systm.h>
61 #include <netinet/in_var.h>
62 #include <netinet/ip.h>
63 #endif
64 
65 #ifdef NS
66 #include <netns/ns.h>
67 #include <netns/ns_if.h>
68 #endif
69 
70 #ifdef ISO
71 #include <netiso/iso.h>
72 #include <netiso/iso_var.h>
73 #endif
74 
75 #include "bpfilter.h"
76 
77 #ifdef TINY_DSMTU
78 #define	DSMTU	(1024+512)
79 #else
80 #define DSMTU	65532
81 #endif
82 
83 static struct	ifnet dsif;
84 static int dsoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
85 		    struct rtentry *);
86 static int dsioctl(struct ifnet *, int, caddr_t);
87 
88 /* ARGSUSED */
89 static void
90 discattach(void)
91 {
92 	register struct ifnet *ifp = &dsif;
93 
94 	ifp->if_name = "ds";
95 	ifp->if_mtu = DSMTU;
96 	ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
97 	ifp->if_ioctl = dsioctl;
98 	ifp->if_output = dsoutput;
99 	ifp->if_type = IFT_LOOP;
100 	ifp->if_hdrlen = 0;
101 	ifp->if_addrlen = 0;
102 	if_attach(ifp);
103 #if NBPFILTER > 0
104 	bpfattach(&ifp->if_bpf, ifp, DLT_NULL, sizeof(u_int));
105 #endif
106 }
107 
108 TEXT_SET(pseudo_set, discattach);
109 
110 static int
111 dsoutput(ifp, m, dst, rt)
112 	struct ifnet *ifp;
113 	register struct mbuf *m;
114 	struct sockaddr *dst;
115 	register struct rtentry *rt;
116 {
117 	int s, isr;
118 	register struct ifqueue *ifq = 0;
119 
120 	if ((m->m_flags & M_PKTHDR) == 0)
121 		panic("dsoutput no HDR");
122 	ifp->if_lastchange = time;
123 #if NBPFILTER > 0
124 	if (dsif.if_bpf) {
125 		/*
126 		 * We need to prepend the address family as
127 		 * a four byte field.  Cons up a dummy header
128 		 * to pacify bpf.  This is safe because bpf
129 		 * will only read from the mbuf (i.e., it won't
130 		 * try to free it or keep a pointer a to it).
131 		 */
132 		struct mbuf m0;
133 		u_int af = dst->sa_family;
134 
135 		m0.m_next = m;
136 		m0.m_len = 4;
137 		m0.m_data = (char *)&af;
138 
139 		bpf_mtap(dsif.if_bpf, &m0);
140 	}
141 #endif
142 	m->m_pkthdr.rcvif = ifp;
143 
144 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
145 		m_freem(m);
146 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
147 		        rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
148 	}
149 	ifp->if_opackets++;
150 	ifp->if_obytes += m->m_pkthdr.len;
151 
152 	m_freem(m);
153 	return 0;
154 }
155 
156 /* ARGSUSED */
157 static void
158 dsrtrequest(cmd, rt, sa)
159 	int cmd;
160 	struct rtentry *rt;
161 	struct sockaddr *sa;
162 {
163 	if (rt)
164 		rt->rt_rmx.rmx_mtu = DSMTU;
165 }
166 
167 /*
168  * Process an ioctl request.
169  */
170 /* ARGSUSED */
171 int
172 dsioctl(ifp, cmd, data)
173 	register struct ifnet *ifp;
174 	int cmd;
175 	caddr_t data;
176 {
177 	register struct ifaddr *ifa;
178 	register struct ifreq *ifr = (struct ifreq *)data;
179 	register int error = 0;
180 
181 	switch (cmd) {
182 
183 	case SIOCSIFADDR:
184 		ifp->if_flags |= IFF_UP;
185 		ifa = (struct ifaddr *)data;
186 		if (ifa != 0)
187 			ifa->ifa_rtrequest = dsrtrequest;
188 		/*
189 		 * Everything else is done at a higher level.
190 		 */
191 		break;
192 
193 	case SIOCADDMULTI:
194 	case SIOCDELMULTI:
195 		if (ifr == 0) {
196 			error = EAFNOSUPPORT;		/* XXX */
197 			break;
198 		}
199 		switch (ifr->ifr_addr.sa_family) {
200 
201 #ifdef INET
202 		case AF_INET:
203 			break;
204 #endif
205 
206 		default:
207 			error = EAFNOSUPPORT;
208 			break;
209 		}
210 		break;
211 
212 	case SIOCSIFMTU:
213 		ifp->if_mtu = ifr->ifr_mtu;
214 		break;
215 
216 	default:
217 		error = EINVAL;
218 	}
219 	return (error);
220 }
221