if_enc.c revision 1.57 
1/*	$OpenBSD: if_enc.c,v 1.57 2014/12/05 15:50:04 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/kernel.h>
25#include <sys/malloc.h>
26#include <sys/socket.h>
27#include <sys/sockio.h>
28#include <sys/mbuf.h>
29
30#include <net/if.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 allocate
103	 * a fake and empty ifa of type AF_LINK for this purpose.
104	 */
105	if_alloc_sadl(ifp);
106
107#if NBPFILTER > 0
108	bpfattach(&ifp->if_bpf, ifp, DLT_ENC, ENC_HDRLEN);
109#endif
110
111	if ((error = enc_setif(ifp, 0)) != 0) {
112		if_detach(ifp);
113		free(sc, M_DEVBUF, 0);
114		return (error);
115	}
116
117	if (unit == 0 || unit > enc_max_unit) {
118		newlen = sizeof(struct ifnet *) * (unit + 1);
119
120		if ((new = malloc(newlen, M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
121			return (ENOBUFS);
122		if (enc_allifps != NULL) {
123			memcpy(new, enc_allifps,
124			    sizeof(struct ifnet *) * (enc_max_unit + 1));
125			free(enc_allifps, M_DEVBUF, 0);
126		}
127		enc_allifps = new;
128		enc_max_unit = unit;
129	}
130	enc_allifps[unit] = ifp;
131
132	return (0);
133}
134
135int
136enc_clone_destroy(struct ifnet *ifp)
137{
138	struct enc_softc	*sc = ifp->if_softc;
139	int			 s;
140
141	/* Protect users from removing enc0 */
142	if (sc->sc_unit == 0)
143		return (EPERM);
144
145	s = splnet();
146	enc_allifps[sc->sc_unit] = NULL;
147	enc_unsetif(ifp);
148	if_detach(ifp);
149	free(sc, M_DEVBUF, 0);
150	splx(s);
151
152	return (0);
153}
154
155void
156enc_start(struct ifnet *ifp)
157{
158	struct mbuf	*m;
159
160	for (;;) {
161		IF_DROP(&ifp->if_snd);
162		IF_DEQUEUE(&ifp->if_snd, m);
163		if (m == NULL)
164			break;
165		m_freem(m);
166	}
167}
168
169int
170enc_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
171    struct rtentry *rt)
172{
173	m_freem(m);	/* drop packet */
174	return (0);
175}
176
177int
178enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
179{
180	struct ifreq	*ifr = (struct ifreq *)data;
181	int		 error;
182
183	switch (cmd) {
184	case SIOCAIFADDR:
185	case SIOCSIFADDR:
186	case SIOCSIFDSTADDR:
187	case SIOCSIFFLAGS:
188		if (ifp->if_flags & IFF_UP)
189			ifp->if_flags |= IFF_RUNNING;
190		else
191			ifp->if_flags &= ~IFF_RUNNING;
192		break;
193	case SIOCSIFRDOMAIN:
194		if ((error = enc_setif(ifp, ifr->ifr_rdomainid)) != 0)
195			return (error);
196		/* FALLTHROUGH */
197	default:
198		return (ENOTTY);
199	}
200
201	return (0);
202}
203
204struct ifnet *
205enc_getif(u_int id, u_int unit)
206{
207	struct ifnet	*ifp;
208
209	/* Check if the caller wants to get a non-default enc interface */
210	if (unit > 0) {
211		if (unit > enc_max_unit)
212			return (NULL);
213		ifp = enc_allifps[unit];
214		if (ifp == NULL || ifp->if_rdomain != id)
215			return (NULL);
216		return (ifp);
217	}
218
219	/* Otherwise return the default enc interface for this rdomain */
220	if (enc_ifps == NULL)
221		return (NULL);
222	else if (id > RT_TABLEID_MAX)
223		return (NULL);
224	else if (id > enc_max_id)
225		return (NULL);
226	return (enc_ifps[id]);
227}
228
229int
230enc_setif(struct ifnet *ifp, u_int id)
231{
232	struct ifnet	**new;
233	size_t		 newlen;
234
235	enc_unsetif(ifp);
236
237	/*
238	 * There can only be one default encif per rdomain -
239	 * Don't overwrite the existing enc iface that is stored
240	 * for this rdomain, so only the first enc interface that
241	 * was added for this rdomain becomes the default.
242	 */
243	if (enc_getif(id, 0) != NULL)
244		return (0);
245
246	if (id > RT_TABLEID_MAX)
247		return (EINVAL);
248
249	if (id == 0 || id > enc_max_id) {
250		newlen = sizeof(struct ifnet *) * (id + 1);
251
252		if ((new = malloc(newlen, M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
253			return (ENOBUFS);
254		if (enc_ifps != NULL) {
255			memcpy(new, enc_ifps,
256			    sizeof(struct ifnet *) * (enc_max_id + 1));
257			free(enc_ifps, M_DEVBUF, 0);
258		}
259		enc_ifps = new;
260		enc_max_id = id;
261	}
262
263	enc_ifps[id] = ifp;
264
265	/* Indicate that this interface is the rdomain default */
266	ifp->if_link_state = LINK_STATE_UP;
267
268	return (0);
269}
270
271void
272enc_unsetif(struct ifnet *ifp)
273{
274	u_int			 id = ifp->if_rdomain, i;
275	struct ifnet		*oifp, *nifp;
276
277	if ((oifp = enc_getif(id, 0)) == NULL || oifp != ifp)
278		return;
279
280	/* Clear slot for this rdomain */
281	enc_ifps[id] = NULL;
282	ifp->if_link_state = LINK_STATE_UNKNOWN;
283
284	/*
285	 * Now find the next available encif to be the default interface
286	 * for this rdomain.
287	 */
288	for (i = 0; i < (enc_max_unit + 1); i++) {
289		nifp = enc_allifps[i];
290
291		if (nifp == NULL || nifp == ifp || nifp->if_rdomain != id)
292			continue;
293
294		enc_ifps[id] = nifp;
295		nifp->if_link_state = LINK_STATE_UP;
296		break;
297	}
298}
299