FreeBSD/Linux Kernel Cross Reference
sys/net/if_disc.c
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 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * From: @(#)if_loop.c 8.1 (Berkeley) 6/10/93
30 * $FreeBSD: releng/6.4/sys/net/if_disc.c 166110 2007-01-19 23:01:34Z jhb $
31 */
32
33 /*
34 * Discard interface driver for protocol testing and timing.
35 * (Based on the loopback.)
36 */
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/malloc.h>
42 #include <sys/module.h>
43 #include <sys/mbuf.h>
44 #include <sys/socket.h>
45 #include <sys/sockio.h>
46
47 #include <net/if.h>
48 #include <net/if_clone.h>
49 #include <net/if_types.h>
50 #include <net/route.h>
51 #include <net/bpf.h>
52
53 #include "opt_inet.h"
54 #include "opt_inet6.h"
55
56 #ifdef TINY_DSMTU
57 #define DSMTU (1024+512)
58 #else
59 #define DSMTU 65532
60 #endif
61
62 #define DISCNAME "disc"
63
64 struct disc_softc {
65 struct ifnet *sc_ifp; /* must be first */
66 LIST_ENTRY(disc_softc) sc_list;
67 };
68
69 static int discoutput(struct ifnet *, struct mbuf *,
70 struct sockaddr *, struct rtentry *);
71 static void discrtrequest(int, struct rtentry *, struct rt_addrinfo *);
72 static int discioctl(struct ifnet *, u_long, caddr_t);
73 static int disc_clone_create(struct if_clone *, int);
74 static void disc_clone_destroy(struct ifnet *);
75
76 static struct mtx disc_mtx;
77 static MALLOC_DEFINE(M_DISC, DISCNAME, "Discard interface");
78 static LIST_HEAD(, disc_softc) disc_softc_list;
79
80 IFC_SIMPLE_DECLARE(disc, 0);
81
82 static int
83 disc_clone_create(struct if_clone *ifc, int unit)
84 {
85 struct ifnet *ifp;
86 struct disc_softc *sc;
87
88 sc = malloc(sizeof(struct disc_softc), M_DISC, M_WAITOK | M_ZERO);
89 ifp = sc->sc_ifp = if_alloc(IFT_LOOP);
90 if (ifp == NULL) {
91 free(sc, M_DISC);
92 return (ENOSPC);
93 }
94
95 ifp->if_softc = sc;
96 if_initname(ifp, ifc->ifc_name, unit);
97 ifp->if_mtu = DSMTU;
98 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
99 ifp->if_drv_flags = IFF_DRV_RUNNING;
100 ifp->if_ioctl = discioctl;
101 ifp->if_output = discoutput;
102 ifp->if_hdrlen = 0;
103 ifp->if_addrlen = 0;
104 ifp->if_snd.ifq_maxlen = 20;
105 if_attach(ifp);
106 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
107 mtx_lock(&disc_mtx);
108 LIST_INSERT_HEAD(&disc_softc_list, sc, sc_list);
109 mtx_unlock(&disc_mtx);
110
111 return (0);
112 }
113
114 static void
115 disc_destroy(struct disc_softc *sc)
116 {
117
118 bpfdetach(sc->sc_ifp);
119 if_detach(sc->sc_ifp);
120 if_free(sc->sc_ifp);
121
122 free(sc, M_DISC);
123 }
124
125 static void
126 disc_clone_destroy(struct ifnet *ifp)
127 {
128 struct disc_softc *sc;
129
130 sc = ifp->if_softc;
131 mtx_lock(&disc_mtx);
132 LIST_REMOVE(sc, sc_list);
133 mtx_unlock(&disc_mtx);
134
135 disc_destroy(sc);
136 }
137
138 static int
139 disc_modevent(module_t mod, int type, void *data)
140 {
141 struct disc_softc *sc;
142
143 switch (type) {
144 case MOD_LOAD:
145 mtx_init(&disc_mtx, "disc_mtx", NULL, MTX_DEF);
146 LIST_INIT(&disc_softc_list);
147 if_clone_attach(&disc_cloner);
148 break;
149 case MOD_UNLOAD:
150 if_clone_detach(&disc_cloner);
151
152 mtx_lock(&disc_mtx);
153 while ((sc = LIST_FIRST(&disc_softc_list)) != NULL) {
154 LIST_REMOVE(sc, sc_list);
155 mtx_unlock(&disc_mtx);
156 disc_destroy(sc);
157 mtx_lock(&disc_mtx);
158 }
159 mtx_unlock(&disc_mtx);
160 mtx_destroy(&disc_mtx);
161 break;
162 default:
163 return (EOPNOTSUPP);
164 }
165 return (0);
166 }
167
168 static moduledata_t disc_mod = {
169 "if_disc",
170 disc_modevent,
171 NULL
172 };
173
174 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
175
176 static int
177 discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
178 struct rtentry *rt)
179 {
180 u_int32_t af;
181
182 M_ASSERTPKTHDR(m);
183
184 /* BPF writes need to be handled specially. */
185 if (dst->sa_family == AF_UNSPEC) {
186 bcopy(dst->sa_data, &af, sizeof(af));
187 dst->sa_family = af;
188 }
189
190 if (bpf_peers_present(ifp->if_bpf)) {
191 u_int af = dst->sa_family;
192 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
193 }
194 m->m_pkthdr.rcvif = ifp;
195
196 ifp->if_opackets++;
197 ifp->if_obytes += m->m_pkthdr.len;
198
199 m_freem(m);
200 return (0);
201 }
202
203 /* ARGSUSED */
204 static void
205 discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info)
206 {
207 RT_LOCK_ASSERT(rt);
208 rt->rt_rmx.rmx_mtu = DSMTU;
209 }
210
211 /*
212 * Process an ioctl request.
213 */
214 static int
215 discioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
216 {
217 struct ifaddr *ifa;
218 struct ifreq *ifr = (struct ifreq *)data;
219 int error = 0;
220
221 switch (cmd) {
222
223 case SIOCSIFADDR:
224 ifp->if_flags |= IFF_UP;
225 ifa = (struct ifaddr *)data;
226 if (ifa != 0)
227 ifa->ifa_rtrequest = discrtrequest;
228 /*
229 * Everything else is done at a higher level.
230 */
231 break;
232
233 case SIOCADDMULTI:
234 case SIOCDELMULTI:
235 if (ifr == 0) {
236 error = EAFNOSUPPORT; /* XXX */
237 break;
238 }
239 switch (ifr->ifr_addr.sa_family) {
240
241 #ifdef INET
242 case AF_INET:
243 break;
244 #endif
245 #ifdef INET6
246 case AF_INET6:
247 break;
248 #endif
249
250 default:
251 error = EAFNOSUPPORT;
252 break;
253 }
254 break;
255
256 case SIOCSIFMTU:
257 ifp->if_mtu = ifr->ifr_mtu;
258 break;
259
260 default:
261 error = EINVAL;
262 }
263 return (error);
264 }
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