xref: /openbsd-src/sys/net/if_loop.c (revision 6a13ef69787db04ae501a22e92fa10865b44fd7c)
1 /*	$OpenBSD: if_loop.c,v 1.78 2017/01/19 23:16:47 mpi Exp $	*/
2 /*	$NetBSD: if_loop.c,v 1.15 1996/05/07 02:40:33 thorpej Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1982, 1986, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *	@(#)if_loop.c	8.1 (Berkeley) 6/10/93
62  */
63 
64 /*
65  *	@(#)COPYRIGHT	1.1 (NRL) 17 January 1995
66  *
67  * NRL grants permission for redistribution and use in source and binary
68  * forms, with or without modification, of the software and documentation
69  * created at NRL provided that the following conditions are met:
70  *
71  * 1. Redistributions of source code must retain the above copyright
72  *    notice, this list of conditions and the following disclaimer.
73  * 2. Redistributions in binary form must reproduce the above copyright
74  *    notice, this list of conditions and the following disclaimer in the
75  *    documentation and/or other materials provided with the distribution.
76  * 3. All advertising materials mentioning features or use of this software
77  *    must display the following acknowledgements:
78  * 	This product includes software developed by the University of
79  * 	California, Berkeley and its contributors.
80  * 	This product includes software developed at the Information
81  * 	Technology Division, US Naval Research Laboratory.
82  * 4. Neither the name of the NRL nor the names of its contributors
83  *    may be used to endorse or promote products derived from this software
84  *    without specific prior written permission.
85  *
86  * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS
87  * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
88  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
89  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL NRL OR
90  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
91  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
92  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
93  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
94  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
95  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
96  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
97  *
98  * The views and conclusions contained in the software and documentation
99  * are those of the authors and should not be interpreted as representing
100  * official policies, either expressed or implied, of the US Naval
101  * Research Laboratory (NRL).
102  */
103 
104 /*
105  * Loopback interface driver for protocol testing and timing.
106  */
107 
108 #include "bpfilter.h"
109 
110 #include <sys/param.h>
111 #include <sys/systm.h>
112 #include <sys/kernel.h>
113 #include <sys/mbuf.h>
114 #include <sys/socket.h>
115 #include <sys/errno.h>
116 #include <sys/ioctl.h>
117 #include <sys/time.h>
118 
119 
120 #include <net/if.h>
121 #include <net/if_var.h>
122 #include <net/if_types.h>
123 #include <net/netisr.h>
124 #include <net/rtable.h>
125 #include <net/route.h>
126 
127 #include <netinet/in.h>
128 
129 #ifdef INET6
130 #include <netinet/ip6.h>
131 #endif
132 
133 #ifdef MPLS
134 #include <netmpls/mpls.h>
135 #endif
136 
137 #if NBPFILTER > 0
138 #include <net/bpf.h>
139 #endif
140 
141 #define	LOMTU	32768
142 
143 int	loioctl(struct ifnet *, u_long, caddr_t);
144 void	loopattach(int);
145 void	lortrequest(struct ifnet *, int, struct rtentry *);
146 int	looutput(struct ifnet *,
147 	    struct mbuf *, struct sockaddr *, struct rtentry *);
148 
149 int	loop_clone_create(struct if_clone *, int);
150 int	loop_clone_destroy(struct ifnet *);
151 
152 struct if_clone loop_cloner =
153     IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy);
154 
155 void
156 loopattach(int n)
157 {
158 	if (loop_clone_create(&loop_cloner, 0))
159 		panic("unable to create lo0");
160 
161 	if_clone_attach(&loop_cloner);
162 }
163 
164 int
165 loop_clone_create(struct if_clone *ifc, int unit)
166 {
167 	struct ifnet *ifp;
168 
169 	ifp = malloc(sizeof(*ifp), M_DEVBUF, M_NOWAIT|M_ZERO);
170 	if (ifp == NULL)
171 		return (ENOMEM);
172 
173 	snprintf(ifp->if_xname, sizeof ifp->if_xname, "lo%d", unit);
174 	ifp->if_softc = NULL;
175 	ifp->if_mtu = LOMTU;
176 	ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
177 	ifp->if_rtrequest = lortrequest;
178 	ifp->if_ioctl = loioctl;
179 	ifp->if_output = looutput;
180 	ifp->if_type = IFT_LOOP;
181 	ifp->if_hdrlen = sizeof(u_int32_t);
182 	ifp->if_addrlen = 0;
183 	if (unit == 0) {
184 		if_attachhead(ifp);
185 		if_addgroup(ifp, ifc->ifc_name);
186 		rtable_l2set(0, 0, ifp->if_index);
187 	} else
188 		if_attach(ifp);
189 	if_alloc_sadl(ifp);
190 #if NBPFILTER > 0
191 	bpfattach(&ifp->if_bpf, ifp, DLT_LOOP, sizeof(u_int32_t));
192 #endif
193 	return (0);
194 }
195 
196 int
197 loop_clone_destroy(struct ifnet *ifp)
198 {
199 	if (ifp->if_index == rtable_loindex(ifp->if_rdomain))
200 		return (EPERM);
201 
202 	if_detach(ifp);
203 
204 	free(ifp, M_DEVBUF, sizeof(*ifp));
205 	return (0);
206 }
207 
208 int
209 looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
210     struct rtentry *rt)
211 {
212 	if ((m->m_flags & M_PKTHDR) == 0)
213 		panic("looutput: no header mbuf");
214 
215 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
216 		m_freem(m);
217 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
218 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
219 	}
220 
221 	return (if_input_local(ifp, m, dst->sa_family));
222 }
223 
224 void
225 lortrequest(struct ifnet *ifp, int cmd, struct rtentry *rt)
226 {
227 	if (rt && rt->rt_rmx.rmx_mtu == 0)
228 		rt->rt_rmx.rmx_mtu = LOMTU;
229 }
230 
231 /*
232  * Process an ioctl request.
233  */
234 int
235 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
236 {
237 	struct ifreq *ifr;
238 	int error = 0;
239 
240 	switch (cmd) {
241 	case SIOCSIFFLAGS:
242 		break;
243 
244 	case SIOCSIFADDR:
245 		ifp->if_flags |= IFF_RUNNING;
246 		if_up(ifp);		/* send up RTM_IFINFO */
247 		/*
248 		 * Everything else is done at a higher level.
249 		 */
250 		break;
251 
252 	case SIOCADDMULTI:
253 	case SIOCDELMULTI:
254 		break;
255 
256 	case SIOCSIFMTU:
257 		ifr = (struct ifreq *)data;
258 		ifp->if_mtu = ifr->ifr_mtu;
259 		break;
260 
261 	default:
262 		error = ENOTTY;
263 	}
264 	return (error);
265 }
266