xref: /freebsd/sys/net/if_disc.c (revision 953a3198a35204535cc9d450f04da982a4fea59b)
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_disc.c,v 1.6 1995/09/09 18:10:21 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 void discattach __P((void *udata));
84 PSEUDO_SET(discattach, if_disc);
85 
86 static struct	ifnet dsif;
87 static int dsoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
88 		    struct rtentry *);
89 static int dsioctl(struct ifnet *, int, caddr_t);
90 
91 /* ARGSUSED */
92 static void
93 discattach(udata)
94 	void *udata;
95 {
96 	register struct ifnet *ifp = &dsif;
97 
98 	ifp->if_name = "ds";
99 	ifp->if_mtu = DSMTU;
100 	ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
101 	ifp->if_ioctl = dsioctl;
102 	ifp->if_output = dsoutput;
103 	ifp->if_type = IFT_LOOP;
104 	ifp->if_hdrlen = 0;
105 	ifp->if_addrlen = 0;
106 	if_attach(ifp);
107 #if NBPFILTER > 0
108 	bpfattach(&ifp->if_bpf, ifp, DLT_NULL, sizeof(u_int));
109 #endif
110 }
111 
112 static int
113 dsoutput(ifp, m, dst, rt)
114 	struct ifnet *ifp;
115 	register struct mbuf *m;
116 	struct sockaddr *dst;
117 	register struct rtentry *rt;
118 {
119 	int s, isr;
120 	register struct ifqueue *ifq = 0;
121 
122 	if ((m->m_flags & M_PKTHDR) == 0)
123 		panic("dsoutput no HDR");
124 	ifp->if_lastchange = time;
125 #if NBPFILTER > 0
126 	/* BPF write needs to be handled specially */
127 	if (dst->sa_family == AF_UNSPEC) {
128 		dst->sa_family = *(mtod(m, int *));
129 		m->m_len -= sizeof(int);
130 		m->m_pkthdr.len -= sizeof(int);
131 		m->m_data += sizeof(int);
132 	}
133 
134 	if (dsif.if_bpf) {
135 		/*
136 		 * We need to prepend the address family as
137 		 * a four byte field.  Cons up a dummy header
138 		 * to pacify bpf.  This is safe because bpf
139 		 * will only read from the mbuf (i.e., it won't
140 		 * try to free it or keep a pointer a to it).
141 		 */
142 		struct mbuf m0;
143 		u_int af = dst->sa_family;
144 
145 		m0.m_next = m;
146 		m0.m_len = 4;
147 		m0.m_data = (char *)&af;
148 
149 		bpf_mtap(dsif.if_bpf, &m0);
150 	}
151 #endif
152 	m->m_pkthdr.rcvif = ifp;
153 
154 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
155 		m_freem(m);
156 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
157 		        rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
158 	}
159 	ifp->if_opackets++;
160 	ifp->if_obytes += m->m_pkthdr.len;
161 
162 	m_freem(m);
163 	return 0;
164 }
165 
166 /* ARGSUSED */
167 static void
168 dsrtrequest(cmd, rt, sa)
169 	int cmd;
170 	struct rtentry *rt;
171 	struct sockaddr *sa;
172 {
173 	if (rt)
174 		rt->rt_rmx.rmx_mtu = DSMTU;
175 }
176 
177 /*
178  * Process an ioctl request.
179  */
180 /* ARGSUSED */
181 int
182 dsioctl(ifp, cmd, data)
183 	register struct ifnet *ifp;
184 	int cmd;
185 	caddr_t data;
186 {
187 	register struct ifaddr *ifa;
188 	register struct ifreq *ifr = (struct ifreq *)data;
189 	register int error = 0;
190 
191 	switch (cmd) {
192 
193 	case SIOCSIFADDR:
194 		ifp->if_flags |= IFF_UP;
195 		ifa = (struct ifaddr *)data;
196 		if (ifa != 0)
197 			ifa->ifa_rtrequest = dsrtrequest;
198 		/*
199 		 * Everything else is done at a higher level.
200 		 */
201 		break;
202 
203 	case SIOCADDMULTI:
204 	case SIOCDELMULTI:
205 		if (ifr == 0) {
206 			error = EAFNOSUPPORT;		/* XXX */
207 			break;
208 		}
209 		switch (ifr->ifr_addr.sa_family) {
210 
211 #ifdef INET
212 		case AF_INET:
213 			break;
214 #endif
215 
216 		default:
217 			error = EAFNOSUPPORT;
218 			break;
219 		}
220 		break;
221 
222 	case SIOCSIFMTU:
223 		ifp->if_mtu = ifr->ifr_mtu;
224 		break;
225 
226 	default:
227 		error = EINVAL;
228 	}
229 	return (error);
230 }
231