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/11.1/sys/net/if_disc.c 302054 2016-06-21 13:48:49Z bz $
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_var.h>
49 #include <net/if_clone.h>
50 #include <net/if_types.h>
51 #include <net/route.h>
52 #include <net/bpf.h>
53 #include <net/vnet.h>
54
55 #include "opt_inet.h"
56 #include "opt_inet6.h"
57
58 #ifdef TINY_DSMTU
59 #define DSMTU (1024+512)
60 #else
61 #define DSMTU 65532
62 #endif
63
64 struct disc_softc {
65 struct ifnet *sc_ifp;
66 };
67
68 static int discoutput(struct ifnet *, struct mbuf *,
69 const struct sockaddr *, struct route *);
70 static int discioctl(struct ifnet *, u_long, caddr_t);
71 static int disc_clone_create(struct if_clone *, int, caddr_t);
72 static void disc_clone_destroy(struct ifnet *);
73
74 static const char discname[] = "disc";
75 static MALLOC_DEFINE(M_DISC, discname, "Discard interface");
76
77 static VNET_DEFINE(struct if_clone *, disc_cloner);
78 #define V_disc_cloner VNET(disc_cloner)
79
80 static int
81 disc_clone_create(struct if_clone *ifc, int unit, caddr_t params)
82 {
83 struct ifnet *ifp;
84 struct disc_softc *sc;
85
86 sc = malloc(sizeof(struct disc_softc), M_DISC, M_WAITOK | M_ZERO);
87 ifp = sc->sc_ifp = if_alloc(IFT_LOOP);
88 if (ifp == NULL) {
89 free(sc, M_DISC);
90 return (ENOSPC);
91 }
92
93 ifp->if_softc = sc;
94 if_initname(ifp, discname, unit);
95 ifp->if_mtu = DSMTU;
96 /*
97 * IFF_LOOPBACK should not be removed from disc's flags because
98 * it controls what PF-specific routes are magically added when
99 * a network address is assigned to the interface. Things just
100 * won't work as intended w/o such routes because the output
101 * interface selection for a packet is totally route-driven.
102 * A valid alternative to IFF_LOOPBACK can be IFF_BROADCAST or
103 * IFF_POINTOPOINT, but it would result in different properties
104 * of the interface.
105 */
106 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
107 ifp->if_drv_flags = IFF_DRV_RUNNING;
108 ifp->if_ioctl = discioctl;
109 ifp->if_output = discoutput;
110 ifp->if_hdrlen = 0;
111 ifp->if_addrlen = 0;
112 ifp->if_snd.ifq_maxlen = 20;
113 if_attach(ifp);
114 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
115
116 return (0);
117 }
118
119 static void
120 disc_clone_destroy(struct ifnet *ifp)
121 {
122 struct disc_softc *sc;
123
124 sc = ifp->if_softc;
125
126 bpfdetach(ifp);
127 if_detach(ifp);
128 if_free(ifp);
129
130 free(sc, M_DISC);
131 }
132
133 static void
134 vnet_disc_init(const void *unused __unused)
135 {
136
137 V_disc_cloner = if_clone_simple(discname, disc_clone_create,
138 disc_clone_destroy, 0);
139 }
140 VNET_SYSINIT(vnet_disc_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
141 vnet_disc_init, NULL);
142
143 static void
144 vnet_disc_uninit(const void *unused __unused)
145 {
146
147 if_clone_detach(V_disc_cloner);
148 }
149 VNET_SYSUNINIT(vnet_disc_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY,
150 vnet_disc_uninit, NULL);
151
152 static int
153 disc_modevent(module_t mod, int type, void *data)
154 {
155
156 switch (type) {
157 case MOD_LOAD:
158 case MOD_UNLOAD:
159 break;
160 default:
161 return (EOPNOTSUPP);
162 }
163 return (0);
164 }
165
166 static moduledata_t disc_mod = {
167 "if_disc",
168 disc_modevent,
169 NULL
170 };
171
172 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
173
174 static int
175 discoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
176 struct route *ro)
177 {
178 u_int32_t af;
179
180 M_ASSERTPKTHDR(m);
181
182 /* BPF writes need to be handled specially. */
183 if (dst->sa_family == AF_UNSPEC)
184 bcopy(dst->sa_data, &af, sizeof(af));
185 else
186 af = dst->sa_family;
187
188 if (bpf_peers_present(ifp->if_bpf))
189 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
190
191 m->m_pkthdr.rcvif = ifp;
192
193 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
194 if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len);
195
196 m_freem(m);
197 return (0);
198 }
199
200 /*
201 * Process an ioctl request.
202 */
203 static int
204 discioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
205 {
206 struct ifreq *ifr = (struct ifreq *)data;
207 int error = 0;
208
209 switch (cmd) {
210 case SIOCSIFADDR:
211 ifp->if_flags |= IFF_UP;
212
213 /*
214 * Everything else is done at a higher level.
215 */
216 break;
217 case SIOCADDMULTI:
218 case SIOCDELMULTI:
219 if (ifr == NULL) {
220 error = EAFNOSUPPORT; /* XXX */
221 break;
222 }
223 switch (ifr->ifr_addr.sa_family) {
224 #ifdef INET
225 case AF_INET:
226 break;
227 #endif
228 #ifdef INET6
229 case AF_INET6:
230 break;
231 #endif
232 default:
233 error = EAFNOSUPPORT;
234 break;
235 }
236 break;
237 case SIOCSIFMTU:
238 ifp->if_mtu = ifr->ifr_mtu;
239 break;
240 default:
241 error = EINVAL;
242 }
243 return (error);
244 }
Cache object: 3e5a155a94fd0f38ff113a59cb2e4594
|