if_enc.c revision 1.61 
1/*	$OpenBSD: if_enc.c,v 1.61 2015/10/22 15:37:47 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 "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_id;
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(struct enc_softc),
81	    M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
82		return (ENOBUFS);
83
84	sc->sc_unit = unit;
85
86	ifp = &sc->sc_if;
87	ifp->if_softc = sc;
88	ifp->if_type = IFT_ENC;
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 rtrequest1()
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_rtrequest = link_rtrequest;
108	sc->sc_ifa.ifa_addr = sdltosa(ifp->if_sadl);
109	sc->sc_ifa.ifa_netmask = NULL;
110
111#if NBPFILTER > 0
112	bpfattach(&ifp->if_bpf, ifp, DLT_ENC, ENC_HDRLEN);
113#endif
114
115	if ((error = enc_setif(ifp, 0)) != 0) {
116		if_detach(ifp);
117		free(sc, M_DEVBUF, 0);
118		return (error);
119	}
120
121	if (unit == 0 || unit > enc_max_unit) {
122		if ((new = mallocarray(unit + 1, sizeof(struct ifnet *),
123		    M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
124			return (ENOBUFS);
125		newlen = sizeof(struct ifnet *) * (unit + 1);
126
127		if (enc_allifps != NULL) {
128			memcpy(new, enc_allifps,
129			    sizeof(struct ifnet *) * (enc_max_unit + 1));
130			free(enc_allifps, M_DEVBUF, 0);
131		}
132		enc_allifps = new;
133		enc_max_unit = unit;
134	}
135	enc_allifps[unit] = ifp;
136
137	return (0);
138}
139
140int
141enc_clone_destroy(struct ifnet *ifp)
142{
143	struct enc_softc	*sc = ifp->if_softc;
144	int			 s;
145
146	/* Protect users from removing enc0 */
147	if (sc->sc_unit == 0)
148		return (EPERM);
149
150	s = splnet();
151	enc_allifps[sc->sc_unit] = NULL;
152	enc_unsetif(ifp);
153	if_detach(ifp);
154	free(sc, M_DEVBUF, 0);
155	splx(s);
156
157	return (0);
158}
159
160void
161enc_start(struct ifnet *ifp)
162{
163	struct mbuf	*m;
164
165	for (;;) {
166		IF_DROP(&ifp->if_snd);
167		IF_DEQUEUE(&ifp->if_snd, m);
168		if (m == NULL)
169			break;
170		m_freem(m);
171	}
172}
173
174int
175enc_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
176    struct rtentry *rt)
177{
178	m_freem(m);	/* drop packet */
179	return (0);
180}
181
182int
183enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
184{
185	struct ifreq	*ifr = (struct ifreq *)data;
186	int		 error;
187
188	switch (cmd) {
189	case SIOCAIFADDR:
190	case SIOCSIFADDR:
191	case SIOCSIFDSTADDR:
192	case SIOCSIFFLAGS:
193		if (ifp->if_flags & IFF_UP)
194			ifp->if_flags |= IFF_RUNNING;
195		else
196			ifp->if_flags &= ~IFF_RUNNING;
197		break;
198	case SIOCSIFRDOMAIN:
199		if ((error = enc_setif(ifp, ifr->ifr_rdomainid)) != 0)
200			return (error);
201		/* FALLTHROUGH */
202	default:
203		return (ENOTTY);
204	}
205
206	return (0);
207}
208
209struct ifnet *
210enc_getif(u_int id, u_int unit)
211{
212	struct ifnet	*ifp;
213
214	/* Check if the caller wants to get a non-default enc interface */
215	if (unit > 0) {
216		if (unit > enc_max_unit)
217			return (NULL);
218		ifp = enc_allifps[unit];
219		if (ifp == NULL || ifp->if_rdomain != id)
220			return (NULL);
221		return (ifp);
222	}
223
224	/* Otherwise return the default enc interface for this rdomain */
225	if (enc_ifps == NULL)
226		return (NULL);
227	else if (id > RT_TABLEID_MAX)
228		return (NULL);
229	else if (id > enc_max_id)
230		return (NULL);
231	return (enc_ifps[id]);
232}
233
234struct ifaddr
235*enc_getifa(u_int id, u_int unit)
236{
237	struct ifnet		*ifp;
238	struct enc_softc	*sc;
239
240	ifp = enc_getif(id, unit);
241	if (ifp == NULL)
242		return (NULL);
243
244	sc = ifp->if_softc;
245	return (&sc->sc_ifa);
246}
247int
248enc_setif(struct ifnet *ifp, u_int id)
249{
250	struct ifnet	**new;
251	size_t		 newlen;
252
253	enc_unsetif(ifp);
254
255	/*
256	 * There can only be one default encif per rdomain -
257	 * Don't overwrite the existing enc iface that is stored
258	 * for this rdomain, so only the first enc interface that
259	 * was added for this rdomain becomes the default.
260	 */
261	if (enc_getif(id, 0) != NULL)
262		return (0);
263
264	if (id > RT_TABLEID_MAX)
265		return (EINVAL);
266
267	if (id == 0 || id > enc_max_id) {
268		if ((new = mallocarray(id + 1, sizeof(struct ifnet *),
269		    M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
270			return (ENOBUFS);
271		newlen = sizeof(struct ifnet *) * (id + 1);
272
273		if (enc_ifps != NULL) {
274			memcpy(new, enc_ifps,
275			    sizeof(struct ifnet *) * (enc_max_id + 1));
276			free(enc_ifps, M_DEVBUF, 0);
277		}
278		enc_ifps = new;
279		enc_max_id = id;
280	}
281
282	enc_ifps[id] = ifp;
283
284	/* Indicate that this interface is the rdomain default */
285	ifp->if_link_state = LINK_STATE_UP;
286
287	return (0);
288}
289
290void
291enc_unsetif(struct ifnet *ifp)
292{
293	u_int			 id = ifp->if_rdomain, i;
294	struct ifnet		*oifp, *nifp;
295
296	if ((oifp = enc_getif(id, 0)) == NULL || oifp != ifp)
297		return;
298
299	/* Clear slot for this rdomain */
300	enc_ifps[id] = NULL;
301	ifp->if_link_state = LINK_STATE_UNKNOWN;
302
303	/*
304	 * Now find the next available encif to be the default interface
305	 * for this rdomain.
306	 */
307	for (i = 0; i < (enc_max_unit + 1); i++) {
308		nifp = enc_allifps[i];
309
310		if (nifp == NULL || nifp == ifp || nifp->if_rdomain != id)
311			continue;
312
313		enc_ifps[id] = nifp;
314		nifp->if_link_state = LINK_STATE_UP;
315		break;
316	}
317}
318