summaryrefslogtreecommitdiff
path: root/sys/net/if_pflog.c
blob: 925fa67c6607738f3c105caf87636cd608865462 (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
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
/*	$OpenBSD: if_pflog.c,v 1.32 2010/09/21 22:49:14 sthen Exp $	*/
/*
 * The authors of this code are John Ioannidis (ji@tla.org),
 * Angelos D. Keromytis (kermit@csd.uch.gr) and 
 * Niels Provos (provos@physnet.uni-hamburg.de).
 *
 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 
 * in November 1995.
 *
 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
 * by Angelos D. Keromytis.
 *
 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
 * and Niels Provos.
 *
 * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis
 * and Niels Provos.
 * Copyright (c) 2001, Angelos D. Keromytis, Niels Provos.
 * Copyright (c) 2002 - 2010 Henning Brauer
 *
 * Permission to use, copy, and modify this software with or without fee
 * is hereby granted, provided that this entire notice is included in
 * all copies of any software which is or includes a copy or
 * modification of this software. 
 * You may use this code under the GNU public license if you so wish. Please
 * contribute changes back to the authors under this freer than GPL license
 * so that we may further the use of strong encryption without limitations to
 * all.
 *
 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
 * PURPOSE.
 */

#include "bpfilter.h"
#include "pflog.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/ioctl.h>

#include <net/if.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/bpf.h>

#ifdef	INET
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <netinet/ip_icmp.h>
#endif

#ifdef INET6
#ifndef INET
#include <netinet/in.h>
#endif
#include <netinet6/nd6.h>
#include <netinet/icmp6.h>
#endif /* INET6 */

#include <net/pfvar.h>
#include <net/if_pflog.h>

#define PFLOGMTU	(32768 + MHLEN + MLEN)

#ifdef PFLOGDEBUG
#define DPRINTF(x)    do { if (pflogdebug) printf x ; } while (0)
#else
#define DPRINTF(x)
#endif

void	pflogattach(int);
int	pflogoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
	    	       struct rtentry *);
int	pflogioctl(struct ifnet *, u_long, caddr_t);
void	pflogstart(struct ifnet *);
int	pflog_clone_create(struct if_clone *, int);
int	pflog_clone_destroy(struct ifnet *);

LIST_HEAD(, pflog_softc)	pflogif_list;
struct if_clone	pflog_cloner =
    IF_CLONE_INITIALIZER("pflog", pflog_clone_create, pflog_clone_destroy);

struct ifnet	*pflogifs[PFLOGIFS_MAX];	/* for fast access */
struct mbuf	*mfake = NULL;

void
pflogattach(int npflog)
{
	int	i;
	LIST_INIT(&pflogif_list);
	for (i = 0; i < PFLOGIFS_MAX; i++)
		pflogifs[i] = NULL;
	if (mfake == NULL)
		mfake = m_get(M_DONTWAIT, MT_HEADER);
	if_clone_attach(&pflog_cloner);
}

int
pflog_clone_create(struct if_clone *ifc, int unit)
{
	struct ifnet *ifp;
	struct pflog_softc *pflogif;
	int s;

	if (unit >= PFLOGIFS_MAX)
		return (EINVAL);

	if ((pflogif = malloc(sizeof(*pflogif),
	    M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
		return (ENOMEM);

	pflogif->sc_unit = unit;
	ifp = &pflogif->sc_if;
	snprintf(ifp->if_xname, sizeof ifp->if_xname, "pflog%d", unit);
	ifp->if_softc = pflogif;
	ifp->if_mtu = PFLOGMTU;
	ifp->if_ioctl = pflogioctl;
	ifp->if_output = pflogoutput;
	ifp->if_start = pflogstart;
	ifp->if_type = IFT_PFLOG;
	ifp->if_snd.ifq_maxlen = ifqmaxlen;
	ifp->if_hdrlen = PFLOG_HDRLEN;
	if_attach(ifp);
	if_alloc_sadl(ifp);

#if NBPFILTER > 0
	bpfattach(&pflogif->sc_if.if_bpf, ifp, DLT_PFLOG, PFLOG_HDRLEN);
#endif

	s = splnet();
	LIST_INSERT_HEAD(&pflogif_list, pflogif, sc_list);
	pflogifs[unit] = ifp;
	splx(s);

	return (0);
}

int
pflog_clone_destroy(struct ifnet *ifp)
{
	struct pflog_softc	*pflogif = ifp->if_softc;
	int			 s;

	s = splnet();
	pflogifs[pflogif->sc_unit] = NULL;
	LIST_REMOVE(pflogif, sc_list);
	splx(s);

	if_detach(ifp);
	free(pflogif, M_DEVBUF);
	return (0);
}

/*
 * Start output on the pflog interface.
 */
void
pflogstart(struct ifnet *ifp)
{
	struct mbuf *m;
	int s;

	for (;;) {
		s = splnet();
		IF_DROP(&ifp->if_snd);
		IF_DEQUEUE(&ifp->if_snd, m);
		splx(s);

		if (m == NULL)
			return;
		else
			m_freem(m);
	}
}

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

/* ARGSUSED */
int
pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
	switch (cmd) {
	case SIOCSIFFLAGS:
		if (ifp->if_flags & IFF_UP)
			ifp->if_flags |= IFF_RUNNING;
		else
			ifp->if_flags &= ~IFF_RUNNING;
		break;
	default:
		return (ENOTTY);
	}

	return (0);
}

int
pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
    u_int8_t reason, struct pf_rule *rm, struct pf_rule *am,
    struct pf_ruleset *ruleset, struct pf_pdesc *pd)
{
#if NBPFILTER > 0
	struct ifnet *ifn;
	struct pfloghdr hdr;

	if (kif == NULL || m == NULL || rm == NULL || pd == NULL)
		return (-1);

	if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf)
		return (0);

	bzero(&hdr, sizeof(hdr));
	hdr.length = PFLOG_REAL_HDRLEN;
	hdr.af = af;
	hdr.action = rm->action;
	hdr.reason = reason;
	memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));

	if (am == NULL) {
		hdr.rulenr = htonl(rm->nr);
		hdr.subrulenr = -1;
	} else {
		hdr.rulenr = htonl(am->nr);
		hdr.subrulenr = htonl(rm->nr);
		if (ruleset != NULL && ruleset->anchor != NULL)
			strlcpy(hdr.ruleset, ruleset->anchor->name,
			    sizeof(hdr.ruleset));
	}
	if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done)
		pd->lookup.done = pf_socket_lookup(dir, pd);
	if (pd->lookup.done > 0) {
		hdr.uid = pd->lookup.uid;
		hdr.pid = pd->lookup.pid;
	} else {
		hdr.uid = UID_MAX;
		hdr.pid = NO_PID;
	}
	hdr.rule_uid = rm->cuid;
	hdr.rule_pid = rm->cpid;
	hdr.dir = dir;

	PF_ACPY(&hdr.saddr, &pd->nsaddr, pd->af);
	PF_ACPY(&hdr.daddr, &pd->ndaddr, pd->af);
	hdr.sport = pd->nsport;
	hdr.dport = pd->ndport;

	ifn->if_opackets++;
	ifn->if_obytes += m->m_pkthdr.len;

	bpf_mtap_pflog(ifn->if_bpf, (caddr_t)&hdr, m);
#endif

	return (0);
}

void
pflog_bpfcopy(const void *src_arg, void *dst_arg, size_t len)
{
	const struct mbuf	*m;
	struct pfloghdr		*pfloghdr;
	u_int			 count;
	u_char			*dst;
	u_short			 action, reason;
	int			 off = 0, hdrlen = 0;
	union {
		struct tcphdr		tcp;
		struct udphdr		udp;
		struct icmp		icmp;
#ifdef INET6
		struct icmp6_hdr	icmp6;
#endif /* INET6 */
	} pf_hdrs;

	struct pf_pdesc		 pd;
	struct pf_addr		 osaddr, odaddr;
	u_int16_t		 osport = 0, odport = 0;

	m = src_arg;
	dst = dst_arg;

	if (m == NULL)
		panic("pflog_bpfcopy got no mbuf");

	/* first mbuf holds struct pfloghdr */
	pfloghdr = mtod(m, struct pfloghdr *);
	count = min(m->m_len, len);
	bcopy(pfloghdr, dst, count);
	pfloghdr = (struct pfloghdr *)dst;
	dst += count;
	len -= count;
	m = m->m_next;

	/* second mbuf is pkthdr */
	if (len > 0) {
		if (m == NULL)
			panic("no second mbuf");
		bcopy(m, mfake, sizeof(*mfake));
		mfake->m_flags &= ~(M_EXT|M_CLUSTER);
		mfake->m_next = NULL;
		mfake->m_nextpkt = NULL;
		mfake->m_data = dst;
		mfake->m_len = len;
	} else
		return;

	while (len > 0) {
		if (m == 0)
			panic("bpf_mcopy");
		count = min(m->m_len, len);
		bcopy(mtod(m, caddr_t), (caddr_t)dst, count);
		m = m->m_next;
		dst += count;
		len -= count;
	}

	if (mfake->m_flags & M_PKTHDR)
		mfake->m_pkthdr.len = min(mfake->m_pkthdr.len, mfake->m_len);

	/* rewrite addresses if needed */
	memset(&pd, 0, sizeof(pd));
	pd.hdr.any = &pf_hdrs;
	if (pf_setup_pdesc(pfloghdr->af, pfloghdr->dir, &pd, mfake, &action,
	    &reason, NULL, NULL, NULL, NULL, &off, &hdrlen) == -1)
		return;

	PF_ACPY(&osaddr, pd.src, pd.af);
	PF_ACPY(&odaddr, pd.dst, pd.af);
	if (pd.sport)
		osport = *pd.sport;
	if (pd.dport)
		odport = *pd.dport;

	if ((pfloghdr->rewritten = pf_translate(&pd, &pfloghdr->saddr,
	    pfloghdr->sport, &pfloghdr->daddr, pfloghdr->dport, 0,
	    pfloghdr->dir, mfake))) {
		m_copyback(mfake, off, min(mfake->m_len - off, hdrlen),
		    pd.hdr.any, M_NOWAIT);
		PF_ACPY(&pfloghdr->saddr, &osaddr, pd.af);
		PF_ACPY(&pfloghdr->daddr, &odaddr, pd.af);
		pfloghdr->sport = osport;
		pfloghdr->dport = odport;
	}
}