1 /* $OpenBSD: if_enc.c,v 1.79 2022/08/29 07:51:45 bluhm Exp $ */
2
3 /*
4 * Copyright (c) 2010 Reyk Floeter <reyk@vantronix.net>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include "bpfilter.h"
20
21 #include <sys/param.h>
22 #include <sys/systm.h>
23 #include <sys/malloc.h>
24 #include <sys/socket.h>
25 #include <sys/sockio.h>
26 #include <sys/mbuf.h>
27
28 #include <net/if.h>
29 #include <net/if_dl.h>
30 #include <net/if_var.h>
31 #include <net/if_enc.h>
32 #include <net/if_types.h>
33 #if NBPFILTER > 0
34 #include <net/bpf.h>
35 #endif
36
37 struct ifnet **enc_ifps; /* rdomain-mapped enc ifs */
38 u_int enc_max_rdomain;
39 struct ifnet **enc_allifps; /* unit-mapped enc ifs */
40 u_int enc_max_unit;
41 #define ENC_MAX_UNITS 4096 /* XXX n per rdomain */
42
43 void encattach(int);
44
45 int enc_clone_create(struct if_clone *, int);
46 int enc_clone_destroy(struct ifnet *);
47 int enc_output(struct ifnet *, struct mbuf *, struct sockaddr *,
48 struct rtentry *);
49 int enc_ioctl(struct ifnet *, u_long, caddr_t);
50
51 int enc_setif(struct ifnet *, u_int);
52 void enc_unsetif(struct ifnet *);
53
54 struct if_clone enc_cloner =
55 IF_CLONE_INITIALIZER("enc", enc_clone_create, enc_clone_destroy);
56
57 void
encattach(int count)58 encattach(int count)
59 {
60 /* Create enc0 by default */
61 (void)enc_clone_create(&enc_cloner, 0);
62
63 if_clone_attach(&enc_cloner);
64 }
65
66 int
enc_clone_create(struct if_clone * ifc,int unit)67 enc_clone_create(struct if_clone *ifc, int unit)
68 {
69 struct enc_softc *sc;
70 struct ifnet *ifp;
71 struct ifnet **new;
72 size_t oldlen;
73 int error;
74
75 if (unit > ENC_MAX_UNITS)
76 return (EINVAL);
77
78 if ((sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
79 return (ENOBUFS);
80
81 sc->sc_unit = unit;
82
83 ifp = &sc->sc_if;
84 ifp->if_softc = sc;
85 ifp->if_type = IFT_ENC;
86 ifp->if_xflags = IFXF_CLONED;
87 ifp->if_output = enc_output;
88 ifp->if_ioctl = enc_ioctl;
89 ifp->if_hdrlen = ENC_HDRLEN;
90
91 snprintf(ifp->if_xname, sizeof(ifp->if_xname), "%s%d",
92 ifc->ifc_name, unit);
93
94 if_attach(ifp);
95 if (unit == 0)
96 if_addgroup(ifp, ifc->ifc_name);
97 /*
98 * enc(4) does not have a link-layer address but rtrequest()
99 * wants an ifa for every route entry. So let's setup a fake
100 * and empty ifa of type AF_LINK for this purpose.
101 */
102 if_alloc_sadl(ifp);
103 refcnt_init_trace(&sc->sc_ifa.ifa_refcnt, DT_REFCNT_IDX_IFADDR);
104 sc->sc_ifa.ifa_ifp = ifp;
105 sc->sc_ifa.ifa_addr = sdltosa(ifp->if_sadl);
106 sc->sc_ifa.ifa_netmask = NULL;
107
108 #if NBPFILTER > 0
109 bpfattach(&ifp->if_bpf, ifp, DLT_ENC, ENC_HDRLEN);
110 #endif
111 NET_LOCK();
112 error = enc_setif(ifp, 0);
113 if (error != 0) {
114 NET_UNLOCK();
115 if_detach(ifp);
116 free(sc, M_DEVBUF, sizeof(*sc));
117 return (error);
118 }
119
120 if (enc_allifps == NULL || unit > enc_max_unit) {
121 if ((new = mallocarray(unit + 1, sizeof(struct ifnet *),
122 M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL) {
123 NET_UNLOCK();
124 return (ENOBUFS);
125 }
126
127 if (enc_allifps != NULL) {
128 oldlen = sizeof(struct ifnet *) * (enc_max_unit + 1);
129 memcpy(new, enc_allifps, oldlen);
130 free(enc_allifps, M_DEVBUF, oldlen);
131 }
132 enc_allifps = new;
133 enc_max_unit = unit;
134 }
135 enc_allifps[unit] = ifp;
136 NET_UNLOCK();
137
138 return (0);
139 }
140
141 int
enc_clone_destroy(struct ifnet * ifp)142 enc_clone_destroy(struct ifnet *ifp)
143 {
144 struct enc_softc *sc = ifp->if_softc;
145
146 /* Protect users from removing enc0 */
147 if (sc->sc_unit == 0)
148 return (EPERM);
149
150 NET_LOCK();
151 enc_allifps[sc->sc_unit] = NULL;
152 enc_unsetif(ifp);
153 NET_UNLOCK();
154
155 if_detach(ifp);
156 if (refcnt_rele(&sc->sc_ifa.ifa_refcnt) == 0) {
157 panic("%s: ifa refcnt has %u refs", __func__,
158 sc->sc_ifa.ifa_refcnt.r_refs);
159 }
160 free(sc, M_DEVBUF, sizeof(*sc));
161
162 return (0);
163 }
164
165 int
enc_output(struct ifnet * ifp,struct mbuf * m,struct sockaddr * sa,struct rtentry * rt)166 enc_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
167 struct rtentry *rt)
168 {
169 m_freem(m); /* drop packet */
170 return (EAFNOSUPPORT);
171 }
172
173 int
enc_ioctl(struct ifnet * ifp,u_long cmd,caddr_t data)174 enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
175 {
176 struct ifreq *ifr = (struct ifreq *)data;
177 int error;
178
179 switch (cmd) {
180 case SIOCSIFADDR:
181 case SIOCSIFDSTADDR:
182 case SIOCSIFFLAGS:
183 if (ifp->if_flags & IFF_UP)
184 ifp->if_flags |= IFF_RUNNING;
185 else
186 ifp->if_flags &= ~IFF_RUNNING;
187 break;
188 case SIOCSIFRDOMAIN:
189 if ((error = enc_setif(ifp, ifr->ifr_rdomainid)) != 0)
190 return (error);
191 /* FALLTHROUGH */
192 default:
193 return (ENOTTY);
194 }
195
196 return (0);
197 }
198
199 struct ifnet *
enc_getif(u_int rdomain,u_int unit)200 enc_getif(u_int rdomain, u_int unit)
201 {
202 struct ifnet *ifp;
203
204 NET_ASSERT_LOCKED();
205
206 /* Check if the caller wants to get a non-default enc interface */
207 if (unit > 0) {
208 if (unit > enc_max_unit)
209 return (NULL);
210 ifp = enc_allifps[unit];
211 if (ifp == NULL || ifp->if_rdomain != rdomain)
212 return (NULL);
213 return (ifp);
214 }
215
216 /* Otherwise return the default enc interface for this rdomain */
217 if (enc_ifps == NULL)
218 return (NULL);
219 else if (rdomain > RT_TABLEID_MAX)
220 return (NULL);
221 else if (rdomain > enc_max_rdomain)
222 return (NULL);
223 return (enc_ifps[rdomain]);
224 }
225
226 struct ifaddr *
enc_getifa(u_int rdomain,u_int unit)227 enc_getifa(u_int rdomain, u_int unit)
228 {
229 struct ifnet *ifp;
230 struct enc_softc *sc;
231
232 ifp = enc_getif(rdomain, unit);
233 if (ifp == NULL)
234 return (NULL);
235
236 sc = ifp->if_softc;
237 return (&sc->sc_ifa);
238 }
239 int
enc_setif(struct ifnet * ifp,u_int rdomain)240 enc_setif(struct ifnet *ifp, u_int rdomain)
241 {
242 struct ifnet **new;
243 size_t oldlen;
244
245 NET_ASSERT_LOCKED();
246
247 enc_unsetif(ifp);
248
249 /*
250 * There can only be one default encif per rdomain -
251 * Don't overwrite the existing enc iface that is stored
252 * for this rdomain, so only the first enc interface that
253 * was added for this rdomain becomes the default.
254 */
255 if (enc_getif(rdomain, 0) != NULL)
256 return (0);
257
258 if (rdomain > RT_TABLEID_MAX)
259 return (EINVAL);
260
261 if (enc_ifps == NULL || rdomain > enc_max_rdomain) {
262 if ((new = mallocarray(rdomain + 1, sizeof(struct ifnet *),
263 M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
264 return (ENOBUFS);
265
266 if (enc_ifps != NULL) {
267 oldlen = sizeof(struct ifnet *) * (enc_max_rdomain + 1);
268 memcpy(new, enc_ifps, oldlen);
269 free(enc_ifps, M_DEVBUF, oldlen);
270 }
271 enc_ifps = new;
272 enc_max_rdomain = rdomain;
273 }
274
275 enc_ifps[rdomain] = ifp;
276
277 /* Indicate that this interface is the rdomain default */
278 ifp->if_link_state = LINK_STATE_UP;
279
280 return (0);
281 }
282
283 void
enc_unsetif(struct ifnet * ifp)284 enc_unsetif(struct ifnet *ifp)
285 {
286 u_int rdomain = ifp->if_rdomain, i;
287 struct ifnet *oifp, *nifp;
288
289 if ((oifp = enc_getif(rdomain, 0)) == NULL || oifp != ifp)
290 return;
291
292 /* Clear slot for this rdomain */
293 enc_ifps[rdomain] = NULL;
294 ifp->if_link_state = LINK_STATE_UNKNOWN;
295
296 /*
297 * Now find the next available encif to be the default interface
298 * for this rdomain.
299 */
300 for (i = 0; i < (enc_max_unit + 1); i++) {
301 nifp = enc_allifps[i];
302
303 if (nifp == NULL || nifp == ifp || nifp->if_rdomain != rdomain)
304 continue;
305
306 enc_ifps[rdomain] = nifp;
307 nifp->if_link_state = LINK_STATE_UP;
308 break;
309 }
310 }
311