if_enc.c revision 1.74 
1/*	$OpenBSD: if_enc.c,v 1.74 2019/06/17 15:13:08 mpi 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 "enc.h"
20#include "bpfilter.h"
21
22#include <sys/param.h>
23#include <sys/systm.h>
24#include <sys/malloc.h>
25#include <sys/socket.h>
26#include <sys/sockio.h>
27#include <sys/mbuf.h>
28
29#include <net/if.h>
30#include <net/if_dl.h>
31#include <net/if_var.h>
32#include <net/if_enc.h>
33#include <net/if_types.h>
34#if NBPFILTER > 0
35#include <net/bpf.h>
36#endif
37
38struct ifnet			**enc_ifps;	/* rdomain-mapped enc ifs */
39u_int				  enc_max_rdomain;
40struct ifnet			**enc_allifps;	/* unit-mapped enc ifs */
41u_int				  enc_max_unit;
42#define ENC_MAX_UNITS		  4096		/* XXX n per rdomain */
43
44void	 encattach(int);
45
46int	 enc_clone_create(struct if_clone *, int);
47int	 enc_clone_destroy(struct ifnet *);
48void	 enc_start(struct ifnet *);
49int	 enc_output(struct ifnet *, struct mbuf *, struct sockaddr *,
50	    struct rtentry *);
51int	 enc_ioctl(struct ifnet *, u_long, caddr_t);
52
53int	 enc_setif(struct ifnet *, u_int);
54void	 enc_unsetif(struct ifnet *);
55
56struct if_clone enc_cloner =
57    IF_CLONE_INITIALIZER("enc", enc_clone_create, enc_clone_destroy);
58
59void
60encattach(int count)
61{
62	/* Create enc0 by default */
63	(void)enc_clone_create(&enc_cloner, 0);
64
65	if_clone_attach(&enc_cloner);
66}
67
68int
69enc_clone_create(struct if_clone *ifc, int unit)
70{
71	struct enc_softc	*sc;
72	struct ifnet		*ifp;
73	struct ifnet		**new;
74	size_t			 newlen;
75	int			 error;
76
77	if (unit > ENC_MAX_UNITS)
78		return (EINVAL);
79
80	if ((sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
81		return (ENOBUFS);
82
83	sc->sc_unit = unit;
84
85	ifp = &sc->sc_if;
86	ifp->if_softc = sc;
87	ifp->if_type = IFT_ENC;
88	ifp->if_xflags = IFXF_CLONED;
89	ifp->if_start = enc_start;
90	ifp->if_output = enc_output;
91	ifp->if_ioctl = enc_ioctl;
92	ifp->if_hdrlen = ENC_HDRLEN;
93
94	snprintf(ifp->if_xname, sizeof(ifp->if_xname), "%s%d",
95	    ifc->ifc_name, unit);
96
97	if_attach(ifp);
98	if (unit == 0)
99		if_addgroup(ifp, ifc->ifc_name);
100	/*
101	 * enc(4) does not have a link-layer address but rtrequest()
102	 * wants an ifa for every route entry.  So let's setup a fake
103	 * and empty ifa of type AF_LINK for this purpose.
104	 */
105	if_alloc_sadl(ifp);
106	sc->sc_ifa.ifa_ifp = ifp;
107	sc->sc_ifa.ifa_addr = sdltosa(ifp->if_sadl);
108	sc->sc_ifa.ifa_netmask = NULL;
109
110#if NBPFILTER > 0
111	bpfattach(&ifp->if_bpf, ifp, DLT_ENC, ENC_HDRLEN);
112#endif
113	NET_LOCK();
114	error = enc_setif(ifp, 0);
115	if (error != 0) {
116		NET_UNLOCK();
117		if_detach(ifp);
118		free(sc, M_DEVBUF, sizeof(*sc));
119		return (error);
120	}
121
122	if (enc_allifps == NULL || unit > enc_max_unit) {
123		if ((new = mallocarray(unit + 1, sizeof(struct ifnet *),
124		    M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL) {
125			NET_UNLOCK();
126			return (ENOBUFS);
127		}
128		newlen = sizeof(struct ifnet *) * (unit + 1);
129
130		if (enc_allifps != NULL) {
131			memcpy(new, enc_allifps,
132			    sizeof(struct ifnet *) * (enc_max_unit + 1));
133			free(enc_allifps, M_DEVBUF,
134			    sizeof(struct ifnet *) * (enc_max_unit + 1));
135		}
136		enc_allifps = new;
137		enc_max_unit = unit;
138	}
139	enc_allifps[unit] = ifp;
140	NET_UNLOCK();
141
142	return (0);
143}
144
145int
146enc_clone_destroy(struct ifnet *ifp)
147{
148	struct enc_softc	*sc = ifp->if_softc;
149
150	/* Protect users from removing enc0 */
151	if (sc->sc_unit == 0)
152		return (EPERM);
153
154	NET_LOCK();
155	enc_allifps[sc->sc_unit] = NULL;
156	enc_unsetif(ifp);
157	NET_UNLOCK();
158
159	if_detach(ifp);
160	free(sc, M_DEVBUF, sizeof(*sc));
161
162	return (0);
163}
164
165void
166enc_start(struct ifnet *ifp)
167{
168	struct mbuf	*m;
169
170	for (;;) {
171		IFQ_DEQUEUE(&ifp->if_snd, m);
172		if (m == NULL)
173			break;
174		m_freem(m);
175	}
176}
177
178int
179enc_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
180    struct rtentry *rt)
181{
182	m_freem(m);	/* drop packet */
183	return (EAFNOSUPPORT);
184}
185
186int
187enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
188{
189	struct ifreq	*ifr = (struct ifreq *)data;
190	int		 error;
191
192	switch (cmd) {
193	case SIOCSIFADDR:
194	case SIOCSIFDSTADDR:
195	case SIOCSIFFLAGS:
196		if (ifp->if_flags & IFF_UP)
197			ifp->if_flags |= IFF_RUNNING;
198		else
199			ifp->if_flags &= ~IFF_RUNNING;
200		break;
201	case SIOCSIFRDOMAIN:
202		if ((error = enc_setif(ifp, ifr->ifr_rdomainid)) != 0)
203			return (error);
204		/* FALLTHROUGH */
205	default:
206		return (ENOTTY);
207	}
208
209	return (0);
210}
211
212struct ifnet *
213enc_getif(u_int rdomain, u_int unit)
214{
215	struct ifnet	*ifp;
216
217	NET_ASSERT_LOCKED();
218
219	/* Check if the caller wants to get a non-default enc interface */
220	if (unit > 0) {
221		if (unit > enc_max_unit)
222			return (NULL);
223		ifp = enc_allifps[unit];
224		if (ifp == NULL || ifp->if_rdomain != rdomain)
225			return (NULL);
226		return (ifp);
227	}
228
229	/* Otherwise return the default enc interface for this rdomain */
230	if (enc_ifps == NULL)
231		return (NULL);
232	else if (rdomain > RT_TABLEID_MAX)
233		return (NULL);
234	else if (rdomain > enc_max_rdomain)
235		return (NULL);
236	return (enc_ifps[rdomain]);
237}
238
239struct ifaddr *
240enc_getifa(u_int rdomain, u_int unit)
241{
242	struct ifnet		*ifp;
243	struct enc_softc	*sc;
244
245	ifp = enc_getif(rdomain, unit);
246	if (ifp == NULL)
247		return (NULL);
248
249	sc = ifp->if_softc;
250	return (&sc->sc_ifa);
251}
252int
253enc_setif(struct ifnet *ifp, u_int rdomain)
254{
255	struct ifnet	**new;
256	size_t		 newlen;
257
258	NET_ASSERT_LOCKED();
259
260	enc_unsetif(ifp);
261
262	/*
263	 * There can only be one default encif per rdomain -
264	 * Don't overwrite the existing enc iface that is stored
265	 * for this rdomain, so only the first enc interface that
266	 * was added for this rdomain becomes the default.
267	 */
268	if (enc_getif(rdomain, 0) != NULL)
269		return (0);
270
271	if (rdomain > RT_TABLEID_MAX)
272		return (EINVAL);
273
274	if (enc_ifps == NULL || rdomain > enc_max_rdomain) {
275		if ((new = mallocarray(rdomain + 1, sizeof(struct ifnet *),
276		    M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
277			return (ENOBUFS);
278		newlen = sizeof(struct ifnet *) * (rdomain + 1);
279
280		if (enc_ifps != NULL) {
281			memcpy(new, enc_ifps,
282			    sizeof(struct ifnet *) * (enc_max_rdomain + 1));
283			free(enc_ifps, M_DEVBUF,
284			    sizeof(struct ifnet *) * (enc_max_rdomain + 1));
285		}
286		enc_ifps = new;
287		enc_max_rdomain = rdomain;
288	}
289
290	enc_ifps[rdomain] = ifp;
291
292	/* Indicate that this interface is the rdomain default */
293	ifp->if_link_state = LINK_STATE_UP;
294
295	return (0);
296}
297
298void
299enc_unsetif(struct ifnet *ifp)
300{
301	u_int			 rdomain = ifp->if_rdomain, i;
302	struct ifnet		*oifp, *nifp;
303
304	if ((oifp = enc_getif(rdomain, 0)) == NULL || oifp != ifp)
305		return;
306
307	/* Clear slot for this rdomain */
308	enc_ifps[rdomain] = NULL;
309	ifp->if_link_state = LINK_STATE_UNKNOWN;
310
311	/*
312	 * Now find the next available encif to be the default interface
313	 * for this rdomain.
314	 */
315	for (i = 0; i < (enc_max_unit + 1); i++) {
316		nifp = enc_allifps[i];
317
318		if (nifp == NULL || nifp == ifp || nifp->if_rdomain != rdomain)
319			continue;
320
321		enc_ifps[rdomain] = nifp;
322		nifp->if_link_state = LINK_STATE_UP;
323		break;
324	}
325}
326