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 * $FreeBSD$
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_if; /* 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
90 ifp = &sc->sc_if;
91
92 ifp->if_softc = sc;
93 if_initname(ifp, ifc->ifc_name, unit);
94 ifp->if_mtu = DSMTU;
95 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
96 ifp->if_ioctl = discioctl;
97 ifp->if_output = discoutput;
98 ifp->if_type = IFT_LOOP;
99 ifp->if_hdrlen = 0;
100 ifp->if_addrlen = 0;
101 ifp->if_snd.ifq_maxlen = 20;
102 if_attach(ifp);
103 bpfattach(ifp, DLT_NULL, sizeof(u_int));
104 mtx_lock(&disc_mtx);
105 LIST_INSERT_HEAD(&disc_softc_list, sc, sc_list);
106 mtx_unlock(&disc_mtx);
107
108 return (0);
109 }
110
111 static void
112 disc_destroy(struct disc_softc *sc)
113 {
114
115 bpfdetach(&sc->sc_if);
116 if_detach(&sc->sc_if);
117
118 free(sc, M_DISC);
119 }
120
121 static void
122 disc_clone_destroy(struct ifnet *ifp)
123 {
124 struct disc_softc *sc;
125
126 sc = ifp->if_softc;
127 mtx_lock(&disc_mtx);
128 LIST_REMOVE(sc, sc_list);
129 mtx_unlock(&disc_mtx);
130
131 disc_destroy(sc);
132 }
133
134 static int
135 disc_modevent(module_t mod, int type, void *data)
136 {
137 struct disc_softc *sc;
138
139 switch (type) {
140 case MOD_LOAD:
141 mtx_init(&disc_mtx, "disc_mtx", NULL, MTX_DEF);
142 LIST_INIT(&disc_softc_list);
143 if_clone_attach(&disc_cloner);
144 break;
145 case MOD_UNLOAD:
146 if_clone_detach(&disc_cloner);
147
148 mtx_lock(&disc_mtx);
149 while ((sc = LIST_FIRST(&disc_softc_list)) != NULL) {
150 LIST_REMOVE(sc, sc_list);
151 mtx_unlock(&disc_mtx);
152 disc_destroy(sc);
153 mtx_lock(&disc_mtx);
154 }
155 mtx_unlock(&disc_mtx);
156 mtx_destroy(&disc_mtx);
157 break;
158 default:
159 return (EOPNOTSUPP);
160 }
161 return (0);
162 }
163
164 static moduledata_t disc_mod = {
165 "if_disc",
166 disc_modevent,
167 NULL
168 };
169
170 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
171
172 static int
173 discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
174 struct rtentry *rt)
175 {
176
177 M_ASSERTPKTHDR(m);
178
179 /* BPF write needs to be handled specially */
180 if (dst->sa_family == AF_UNSPEC) {
181 dst->sa_family = *(mtod(m, int *));
182 m->m_len -= sizeof(int);
183 m->m_pkthdr.len -= sizeof(int);
184 m->m_data += sizeof(int);
185 }
186
187 if (ifp->if_bpf) {
188 u_int af = dst->sa_family;
189 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
190 }
191 m->m_pkthdr.rcvif = ifp;
192
193 ifp->if_opackets++;
194 ifp->if_obytes += m->m_pkthdr.len;
195
196 m_freem(m);
197 return (0);
198 }
199
200 /* ARGSUSED */
201 static void
202 discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info)
203 {
204 RT_LOCK_ASSERT(rt);
205
206 if (rt)
207 rt->rt_rmx.rmx_mtu = DSMTU;
208 }
209
210 /*
211 * Process an ioctl request.
212 */
213 static int
214 discioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
215 {
216 struct ifaddr *ifa;
217 struct ifreq *ifr = (struct ifreq *)data;
218 int error = 0;
219
220 switch (cmd) {
221
222 case SIOCSIFADDR:
223 ifp->if_flags |= IFF_UP;
224 ifa = (struct ifaddr *)data;
225 if (ifa != 0)
226 ifa->ifa_rtrequest = discrtrequest;
227 /*
228 * Everything else is done at a higher level.
229 */
230 break;
231
232 case SIOCADDMULTI:
233 case SIOCDELMULTI:
234 if (ifr == 0) {
235 error = EAFNOSUPPORT; /* XXX */
236 break;
237 }
238 switch (ifr->ifr_addr.sa_family) {
239
240 #ifdef INET
241 case AF_INET:
242 break;
243 #endif
244 #ifdef INET6
245 case AF_INET6:
246 break;
247 #endif
248
249 default:
250 error = EAFNOSUPPORT;
251 break;
252 }
253 break;
254
255 case SIOCSIFMTU:
256 ifp->if_mtu = ifr->ifr_mtu;
257 break;
258
259 default:
260 error = EINVAL;
261 }
262 return (error);
263 }
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