summaryrefslogtreecommitdiffstats
path: root/sys/net/if_enc.c
blob: 387568957aa7d555e6f86e02ba6441f01118be33 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
/*-
 * Copyright (c) 2006 The FreeBSD Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <machine/bus.h>
#include <sys/rman.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>

#include <net/if.h>
#include <net/if_clone.h>
#include <net/if_types.h>
#include <net/pfil.h>
#include <net/route.h>
#include <net/netisr.h>
#include <net/bpf.h>
#include <net/bpfdesc.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/in_var.h>
#include "opt_inet6.h"

#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#endif

#include <netipsec/ipsec.h>

#define ENCMTU		(1024+512)

/* XXX this define must have the same value as in OpenBSD */
#define M_CONF		0x0400	/* payload was encrypted (ESP-transport) */
#define M_AUTH		0x0800	/* payload was authenticated (AH or ESP auth) */
#define M_AUTH_AH	0x2000	/* header was authenticated (AH) */

struct enchdr {
	u_int32_t af;
	u_int32_t spi;
	u_int32_t flags;
};

static struct ifnet	*encif;
static struct mtx	enc_mtx;

struct enc_softc {
	struct	ifnet *sc_ifp;
};

static int	enc_ioctl(struct ifnet *, u_long, caddr_t);
static int	enc_output(struct ifnet *ifp, struct mbuf *m,
		    struct sockaddr *dst, struct rtentry *rt);
static int	enc_clone_create(struct if_clone *, int, caddr_t);
static void	enc_clone_destroy(struct ifnet *);

IFC_SIMPLE_DECLARE(enc, 1);

static void
enc_clone_destroy(struct ifnet *ifp)
{
	KASSERT(ifp != encif, ("%s: destroying encif", __func__));

	bpfdetach(ifp);
	if_detach(ifp);
	if_free(ifp);
}

static int
enc_clone_create(struct if_clone *ifc, int unit, caddr_t params)
{
	struct ifnet *ifp;
	struct enc_softc *sc;

	sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK|M_ZERO);
	ifp = sc->sc_ifp = if_alloc(IFT_ENC);
	if (ifp == NULL) {
		free(sc, M_DEVBUF);
		return (ENOSPC);
	}

	if_initname(ifp, ifc->ifc_name, unit);
	ifp->if_mtu = ENCMTU;
	ifp->if_ioctl = enc_ioctl;
	ifp->if_output = enc_output;
	ifp->if_snd.ifq_maxlen = ifqmaxlen;
	ifp->if_softc = sc;
	if_attach(ifp);
	bpfattach(ifp, DLT_ENC, sizeof(struct enchdr));

	mtx_lock(&enc_mtx);
	/* grab a pointer to enc0, ignore the rest */
	if (encif == NULL)
		encif = ifp;
	mtx_unlock(&enc_mtx);

	return (0);
}

static int
enc_modevent(module_t mod, int type, void *data)
{
	switch (type) {
	case MOD_LOAD:
		mtx_init(&enc_mtx, "enc mtx", NULL, MTX_DEF);
		if_clone_attach(&enc_cloner);
		break;
	case MOD_UNLOAD:
		printf("enc module unload - not possible for this module\n");
		return (EINVAL);
	default:
		return (EOPNOTSUPP);
	}
	return (0);
}

static moduledata_t enc_mod = {
	"enc",
	enc_modevent,
	0
};

DECLARE_MODULE(enc, enc_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY);

static int
enc_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
    struct rtentry *rt)
{
	m_freem(m);
	return (0);
}

/*
 * Process an ioctl request.
 */
/* ARGSUSED */
static int
enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
	int error = 0;

	mtx_lock(&enc_mtx);

	switch (cmd) {

	case SIOCSIFFLAGS:
		if (ifp->if_flags & IFF_UP)
			ifp->if_drv_flags |= IFF_DRV_RUNNING;
		else
			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;

		break;

	default:
		error = EINVAL;
	}

	mtx_unlock(&enc_mtx);
	return (error);
}

int
ipsec_filter(struct mbuf **mp, int dir)
{
	int error, i;
	struct ip *ip;

	KASSERT(encif != NULL, ("%s: encif is null", __func__));

	if ((encif->if_drv_flags & IFF_DRV_RUNNING) == 0)
		return (0);

	/* Skip pfil(9) if no filters are loaded */
	if (!(PFIL_HOOKED(&inet_pfil_hook)
#ifdef INET6
	    || PFIL_HOOKED(&inet6_pfil_hook)
#endif
	    )) {
		return (0);
	}

	i = min((*mp)->m_pkthdr.len, max_protohdr);
	if ((*mp)->m_len < i) {
		*mp = m_pullup(*mp, i);
		if (*mp == NULL) {
			printf("%s: m_pullup failed\n", __func__);
			return (-1);
		}
	}

	error = 0;
	ip = mtod(*mp, struct ip *);
	switch (ip->ip_v) {
		case 4:
			/*
			 * before calling the firewall, swap fields the same as
			 * IP does. here we assume the header is contiguous
			 */
			ip->ip_len = ntohs(ip->ip_len);
			ip->ip_off = ntohs(ip->ip_off);

			error = pfil_run_hooks(&inet_pfil_hook, mp,
			    encif, dir, NULL);

			if (*mp == NULL || error != 0)
				break;

			/* restore byte ordering */
			ip = mtod(*mp, struct ip *);
			ip->ip_len = htons(ip->ip_len);
			ip->ip_off = htons(ip->ip_off);
			break;

#ifdef INET6
		case 6:
			error = pfil_run_hooks(&inet6_pfil_hook, mp,
			    encif, dir, NULL);
			break;
#endif
		default:
			printf("%s: unknown IP version\n", __func__);
	}

	if (*mp == NULL)
		return (error);
	if (error != 0)
		goto bad;

	return (error);

bad:
	m_freem(*mp);
	*mp = NULL;
	return (error);
}

void
ipsec_bpf(struct mbuf *m, struct secasvar *sav, int af)
{
	int flags;
	struct enchdr hdr;

	KASSERT(encif != NULL, ("%s: encif is null", __func__));
	KASSERT(sav != NULL, ("%s: sav is null", __func__));

	if ((encif->if_drv_flags & IFF_DRV_RUNNING) == 0)
		return;

	if (encif->if_bpf) {
		flags = 0;
		if (sav->alg_enc != SADB_EALG_NONE)
			flags |= M_CONF;
		if (sav->alg_auth != SADB_AALG_NONE)
			flags |= M_AUTH;

		/*
		 * We need to prepend the address family as a four byte
		 * field.  Cons up a dummy header to pacify bpf.  This
		 * is safe because bpf will only read from the mbuf
		 * (i.e., it won't try to free it or keep a pointer a
		 * to it).
		 */
		hdr.af = af;
		hdr.spi = sav->spi;
		hdr.flags = flags;

		bpf_mtap2(encif->if_bpf, &hdr, sizeof(hdr), m);
	}
}
OpenPOWER on IntegriCloud