if_enc.c revision 1.52 
1/*	$OpenBSD: if_enc.c,v 1.52 2010/07/03 04:44:51 guenther 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_enc.h>
32#include <net/if_types.h>
33#include <net/route.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
76	if (unit > ENC_MAX_UNITS)
77		return (EINVAL);
78
79	if ((sc = malloc(sizeof(struct enc_softc),
80	    M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
81		return (ENOMEM);
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_start = enc_start;
89	ifp->if_output = enc_output;
90	ifp->if_ioctl = enc_ioctl;
91	ifp->if_hdrlen = ENC_HDRLEN;
92
93	snprintf(ifp->if_xname, sizeof(ifp->if_xname), "%s%d",
94	    ifc->ifc_name, unit);
95
96	if_attach(ifp);
97	if (unit == 0)
98		if_addgroup(ifp, ifc->ifc_name);
99	if_alloc_sadl(ifp);
100
101#if NBPFILTER > 0
102	bpfattach(&ifp->if_bpf, ifp, DLT_ENC, ENC_HDRLEN);
103#endif
104
105	if (enc_setif(ifp, 0) != 0) {
106		if_detach(ifp);
107		free(sc, M_DEVBUF);
108		return (-1);
109	}
110
111	if (unit == 0 || unit > enc_max_unit) {
112		newlen = sizeof(struct ifnet *) * (unit + 1);
113
114		if ((new = malloc(newlen, M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
115			return (-1);
116		if (enc_allifps != NULL) {
117			memcpy(new, enc_allifps,
118			    sizeof(struct ifnet *) * (enc_max_unit + 1));
119			free(enc_allifps, M_DEVBUF);
120		}
121		enc_allifps = new;
122		enc_max_unit = unit;
123	}
124	enc_allifps[unit] = ifp;
125
126	return (0);
127}
128
129int
130enc_clone_destroy(struct ifnet *ifp)
131{
132	struct enc_softc	*sc = ifp->if_softc;
133	int			 s;
134
135	/* Protect users from removing enc0 */
136	if (sc->sc_unit == 0)
137		return (EPERM);
138
139	s = splnet();
140	enc_allifps[sc->sc_unit] = NULL;
141	enc_unsetif(ifp);
142	if_detach(ifp);
143	free(sc, M_DEVBUF);
144	splx(s);
145
146	return (0);
147}
148
149void
150enc_start(struct ifnet *ifp)
151{
152	struct mbuf	*m;
153
154	for (;;) {
155		IF_DROP(&ifp->if_snd);
156		IF_DEQUEUE(&ifp->if_snd, m);
157		if (m == NULL)
158			break;
159		m_freem(m);
160	}
161}
162
163int
164enc_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
165    struct rtentry *rt)
166{
167	m_freem(m);	/* drop packet */
168	return (0);
169}
170
171int
172enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
173{
174	struct ifreq	*ifr = (struct ifreq *)data;
175	int		 error = 0;
176
177	switch (cmd) {
178	case SIOCAIFADDR:
179	case SIOCSIFADDR:
180	case SIOCSIFDSTADDR:
181	case SIOCSIFFLAGS:
182		if (ifp->if_flags & IFF_UP)
183			ifp->if_flags |= IFF_RUNNING;
184		else
185			ifp->if_flags &= ~IFF_RUNNING;
186		break;
187	case SIOCSIFRDOMAIN:
188		if ((error = enc_setif(ifp, ifr->ifr_rdomainid)) != 0)
189			return (error);
190		/* FALLTHROUGH */
191	default:
192		return (ENOTTY);
193	}
194
195	return (0);
196}
197
198struct ifnet *
199enc_getif(u_int id, u_int unit)
200{
201	struct ifnet	*ifp;
202
203	/* Check if the caller wants to get a non-default enc interface */
204	if (unit > 0) {
205		if (unit > enc_max_unit)
206			return (NULL);
207		ifp = enc_allifps[unit];
208		if (ifp == NULL || ifp->if_rdomain != id)
209			return (NULL);
210		return (ifp);
211	}
212
213	/* Otherwise return the default enc interface for this rdomain */
214	if (enc_ifps == NULL)
215		return (NULL);
216	else if (id > RT_TABLEID_MAX)
217		return (NULL);
218	else if (id > enc_max_id)
219		return (NULL);
220	return (enc_ifps[id]);
221}
222
223int
224enc_setif(struct ifnet *ifp, u_int id)
225{
226	struct ifnet	**new;
227	size_t		 newlen;
228
229	enc_unsetif(ifp);
230
231	/*
232	 * There can only be one default encif per rdomain -
233	 * Don't overwrite the existing enc iface that is stored
234	 * for this rdomain, so only the first enc interface that
235	 * was added for this rdomain becomes the default.
236	 */
237	if (enc_getif(id, 0) != NULL)
238		return (0);
239
240	if (id > RT_TABLEID_MAX)
241		return (-1);
242
243	if (id == 0 || id > enc_max_id) {
244		newlen = sizeof(struct ifnet *) * (id + 1);
245
246		if ((new = malloc(newlen, M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
247			return (-1);
248		if (enc_ifps != NULL) {
249			memcpy(new, enc_ifps,
250			    sizeof(struct ifnet *) * (enc_max_id + 1));
251			free(enc_ifps, M_DEVBUF);
252		}
253		enc_ifps = new;
254		enc_max_id = id;
255	}
256
257	enc_ifps[id] = ifp;
258
259	/* Indicate that this interface is the rdomain default */
260	ifp->if_link_state = LINK_STATE_UP;
261
262	return (0);
263}
264
265void
266enc_unsetif(struct ifnet *ifp)
267{
268	u_int			 id = ifp->if_rdomain, i;
269	struct ifnet		*oifp, *nifp;
270
271	if ((oifp = enc_getif(id, 0)) == NULL || oifp != ifp)
272		return;
273
274	/* Clear slot for this rdomain */
275	enc_ifps[id] = NULL;
276	ifp->if_link_state = LINK_STATE_UNKNOWN;
277
278	/*
279	 * Now find the next available encif to be the default interface
280	 * for this rdomain.
281	 */
282	for (i = 0; i < (enc_max_unit + 1); i++) {
283		nifp = enc_allifps[i];
284
285		if (nifp == NULL || nifp == ifp || nifp->if_rdomain != id)
286			continue;
287
288		enc_ifps[id] = nifp;
289		nifp->if_link_state = LINK_STATE_UP;
290		break;
291	}
292}
293