xref: /openbsd-src/sys/net/if_enc.c (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /*	$OpenBSD: if_enc.c,v 1.55 2014/07/12 18:44:22 tedu 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 
38 struct ifnet			**enc_ifps;	/* rdomain-mapped enc ifs */
39 u_int				  enc_max_id;
40 struct ifnet			**enc_allifps;	/* unit-mapped enc ifs */
41 u_int				  enc_max_unit;
42 #define ENC_MAX_UNITS		  4096		/* XXX n per rdomain */
43 
44 void	 encattach(int);
45 
46 int	 enc_clone_create(struct if_clone *, int);
47 int	 enc_clone_destroy(struct ifnet *);
48 void	 enc_start(struct ifnet *);
49 int	 enc_output(struct ifnet *, struct mbuf *, struct sockaddr *,
50 	    struct rtentry *);
51 int	 enc_ioctl(struct ifnet *, u_long, caddr_t);
52 
53 int	 enc_setif(struct ifnet *, u_int);
54 void	 enc_unsetif(struct ifnet *);
55 
56 struct if_clone enc_cloner =
57     IF_CLONE_INITIALIZER("enc", enc_clone_create, enc_clone_destroy);
58 
59 void
60 encattach(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 
68 int
69 enc_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 
135 int
136 enc_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 
155 void
156 enc_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 
169 int
170 enc_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 
177 int
178 enc_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 
204 struct ifnet *
205 enc_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 
229 int
230 enc_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 
271 void
272 enc_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