xref: /netbsd-src/sys/dist/pf/net/if_pflog.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*	$NetBSD: if_pflog.c,v 1.14 2008/12/19 18:49:38 cegger Exp $	*/
2 /*	$OpenBSD: if_pflog.c,v 1.24 2007/05/26 17:13:30 jason Exp $	*/
3 
4 /*
5  * The authors of this code are John Ioannidis (ji@tla.org),
6  * Angelos D. Keromytis (kermit@csd.uch.gr) and
7  * Niels Provos (provos@physnet.uni-hamburg.de).
8  *
9  * This code was written by John Ioannidis for BSD/OS in Athens, Greece,
10  * in November 1995.
11  *
12  * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
13  * by Angelos D. Keromytis.
14  *
15  * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
16  * and Niels Provos.
17  *
18  * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis
19  * and Niels Provos.
20  * Copyright (c) 2001, Angelos D. Keromytis, Niels Provos.
21  *
22  * Permission to use, copy, and modify this software with or without fee
23  * is hereby granted, provided that this entire notice is included in
24  * all copies of any software which is or includes a copy or
25  * modification of this software.
26  * You may use this code under the GNU public license if you so wish. Please
27  * contribute changes back to the authors under this freer than GPL license
28  * so that we may further the use of strong encryption without limitations to
29  * all.
30  *
31  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
32  * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
33  * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
34  * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
35  * PURPOSE.
36  */
37 
38 #include <sys/cdefs.h>
39 __KERNEL_RCSID(0, "$NetBSD: if_pflog.c,v 1.14 2008/12/19 18:49:38 cegger Exp $");
40 
41 #ifdef _KERNEL_OPT
42 #include "opt_inet.h"
43 #endif
44 
45 #include "bpfilter.h"
46 #include "pflog.h"
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/mbuf.h>
51 #include <sys/proc.h>
52 #include <sys/socket.h>
53 #include <sys/ioctl.h>
54 
55 #include <net/if.h>
56 #include <net/if_types.h>
57 #include <net/route.h>
58 #include <net/bpf.h>
59 
60 #ifdef	INET
61 #include <netinet/in.h>
62 #include <netinet/in_var.h>
63 #include <netinet/in_systm.h>
64 #include <netinet/ip.h>
65 #endif
66 
67 #ifdef INET6
68 #ifndef INET
69 #include <netinet/in.h>
70 #endif
71 #include <netinet6/nd6.h>
72 #endif /* INET6 */
73 
74 #include <net/pfvar.h>
75 #include <net/if_pflog.h>
76 
77 #define PFLOGMTU	(32768 + MHLEN + MLEN)
78 
79 #ifdef PFLOGDEBUG
80 #define DPRINTF(x)    do { if (pflogdebug) printf x ; } while (0)
81 #else
82 #define DPRINTF(x)
83 #endif
84 
85 void	pflogattach(int);
86 #ifdef _LKM
87 void	pflogdetach(void);
88 #endif /* _LKM */
89 int	pflogoutput(struct ifnet *, struct mbuf *, const struct sockaddr *,
90 	    	       struct rtentry *);
91 int	pflogioctl(struct ifnet *, u_long, void *);
92 void	pflogstart(struct ifnet *);
93 int	pflog_clone_create(struct if_clone *, int);
94 int	pflog_clone_destroy(struct ifnet *);
95 
96 LIST_HEAD(, pflog_softc)	pflogif_list;
97 struct if_clone	pflog_cloner =
98     IF_CLONE_INITIALIZER("pflog", pflog_clone_create, pflog_clone_destroy);
99 
100 struct ifnet	*pflogifs[PFLOGIFS_MAX];	/* for fast access */
101 
102 void
103 pflogattach(int npflog)
104 {
105 	int i;
106 
107 	LIST_INIT(&pflogif_list);
108 	for (i = 0; i < PFLOGIFS_MAX; i++)
109 		pflogifs[i] = NULL;
110 	if_clone_attach(&pflog_cloner);
111 }
112 
113 #ifdef _LKM
114 void
115 pflogdetach(void)
116 {
117 	int i;
118 
119 	for (i = 0; i < PFLOGIFS_MAX; i++) {
120 		if (pflogifs[i] != NULL)
121 			pflog_clone_destroy(pflogifs[i]);
122 	}
123 	if_clone_detach(&pflog_cloner);
124 }
125 #endif /* _LKM */
126 
127 int
128 pflog_clone_create(struct if_clone *ifc, int unit)
129 {
130 	struct ifnet *ifp;
131 	struct pflog_softc *pflogif;
132 	int s;
133 
134 	if (unit >= PFLOGIFS_MAX)
135 		return (EINVAL);
136 
137 	if ((pflogif = malloc(sizeof(*pflogif), M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
138 		return (ENOMEM);
139 
140 	pflogif->sc_unit = unit;
141 	ifp = &pflogif->sc_if;
142 	snprintf(ifp->if_xname, sizeof ifp->if_xname, "pflog%d", unit);
143 	ifp->if_softc = pflogif;
144 	ifp->if_mtu = PFLOGMTU;
145 	ifp->if_ioctl = pflogioctl;
146 	ifp->if_output = pflogoutput;
147 	ifp->if_start = pflogstart;
148 	ifp->if_type = IFT_PFLOG;
149 #ifndef __NetBSD__
150 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
151 #endif /* !__NetBSD__ */
152 	ifp->if_hdrlen = PFLOG_HDRLEN;
153 	if_attach(ifp);
154 	if_alloc_sadl(ifp);
155 
156 #if NBPFILTER > 0
157 #ifdef __NetBSD__
158 	bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN);
159 #else
160 	bpfattach(&pflogif->sc_if.if_bpf, ifp, DLT_PFLOG, PFLOG_HDRLEN);
161 #endif /* !__NetBSD__ */
162 #endif
163 
164 	s = splnet();
165 	LIST_INSERT_HEAD(&pflogif_list, pflogif, sc_list);
166 	pflogifs[unit] = ifp;
167 	splx(s);
168 
169 	return (0);
170 }
171 
172 int
173 pflog_clone_destroy(struct ifnet *ifp)
174 {
175 	struct pflog_softc	*pflogif = ifp->if_softc;
176 	int			 s;
177 
178 	s = splnet();
179 	pflogifs[pflogif->sc_unit] = NULL;
180 	LIST_REMOVE(pflogif, sc_list);
181 	splx(s);
182 
183 #if NBPFILTER > 0
184 	bpfdetach(ifp);
185 #endif
186 	if_detach(ifp);
187 	free(pflogif, M_DEVBUF);
188 	return (0);
189 }
190 
191 /*
192  * Start output on the pflog interface.
193  */
194 void
195 pflogstart(struct ifnet *ifp)
196 {
197 	struct mbuf *m;
198 	int s;
199 
200 	for (;;) {
201 		s = splnet();
202 		IF_DROP(&ifp->if_snd);
203 		IF_DEQUEUE(&ifp->if_snd, m);
204 		splx(s);
205 
206 		if (m == NULL)
207 			return;
208 		else
209 			m_freem(m);
210 	}
211 }
212 
213 int
214 pflogoutput(struct ifnet *ifp, struct mbuf *m,
215     const struct sockaddr *dst, struct rtentry *rt)
216 {
217 	m_freem(m);
218 	return (0);
219 }
220 
221 /* ARGSUSED */
222 int
223 pflogioctl(struct ifnet *ifp, u_long cmd, void *data)
224 {
225 	int error = 0;
226 
227 	switch (cmd) {
228 	case SIOCSIFFLAGS:
229 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
230 			break;
231 		/*FALLTHROUGH*/
232 	case SIOCINITIFADDR:
233 	case SIOCAIFADDR:
234 	case SIOCSIFDSTADDR:
235 		if (ifp->if_flags & IFF_UP)
236 			ifp->if_flags |= IFF_RUNNING;
237 		else
238 			ifp->if_flags &= ~IFF_RUNNING;
239 		break;
240 	default:
241 		error = ifioctl_common(ifp, cmd, data);
242 	}
243 
244 	return error;
245 }
246 
247 int
248 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
249     u_int8_t reason, struct pf_rule *rm, struct pf_rule *am,
250     struct pf_ruleset *ruleset, struct pf_pdesc *pd)
251 {
252 #if NBPFILTER > 0
253 	struct ifnet *ifn;
254 	struct pfloghdr hdr;
255 
256 	if (kif == NULL || m == NULL || rm == NULL || pd == NULL)
257 		return (-1);
258 
259 	if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf)
260 		return (0);
261 
262 	bzero(&hdr, sizeof(hdr));
263 	hdr.length = PFLOG_REAL_HDRLEN;
264 	hdr.af = af;
265 	hdr.action = rm->action;
266 	hdr.reason = reason;
267 	memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));
268 
269 	if (am == NULL) {
270 		hdr.rulenr = htonl(rm->nr);
271 		hdr.subrulenr = -1;
272 	} else {
273 		hdr.rulenr = htonl(am->nr);
274 		hdr.subrulenr = htonl(rm->nr);
275 		if (ruleset != NULL && ruleset->anchor != NULL)
276 			strlcpy(hdr.ruleset, ruleset->anchor->name,
277 			    sizeof(hdr.ruleset));
278 	}
279 	if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done)
280 		pd->lookup.done = pf_socket_lookup(dir, pd);
281 	if (pd->lookup.done > 0) {
282 		hdr.uid = pd->lookup.uid;
283 		hdr.pid = pd->lookup.pid;
284 	} else {
285 		hdr.uid = UID_MAX;
286 		hdr.pid = NO_PID;
287 	}
288 	hdr.rule_uid = rm->cuid;
289 	hdr.rule_pid = rm->cpid;
290 	hdr.dir = dir;
291 
292 #ifdef INET
293 	if (af == AF_INET && dir == PF_OUT) {
294 		struct ip *ip;
295 
296 		ip = mtod(m, struct ip *);
297 		ip->ip_sum = 0;
298 		ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
299 	}
300 #endif /* INET */
301 
302 	ifn->if_opackets++;
303 	ifn->if_obytes += m->m_pkthdr.len;
304 
305 #ifdef __NetBSD__
306 	bpf_mtap2(ifn->if_bpf, &hdr, PFLOG_HDRLEN, m);
307 #else
308 	bpf_mtap_hdr(ifn->if_bpf, (char *)&hdr, PFLOG_HDRLEN, m,
309 	    BPF_DIRECTION_OUT);
310 #endif /* !__NetBSD__ */
311 
312 #endif
313 
314 	return (0);
315 }
316