xref: /netbsd-src/sys/dist/pf/net/if_pflog.c (revision cac8e449158efc7261bebc8657cbb0125a2cfdde)
1 /*	$NetBSD: if_pflog.c,v 1.12 2008/06/18 09:06:27 yamt 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 1.12 2008/06/18 09:06:27 yamt 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)) == NULL)
138 		return (ENOMEM);
139 	bzero(pflogif, sizeof(*pflogif));
140 
141 	pflogif->sc_unit = unit;
142 	ifp = &pflogif->sc_if;
143 	snprintf(ifp->if_xname, sizeof ifp->if_xname, "pflog%d", unit);
144 	ifp->if_softc = pflogif;
145 	ifp->if_mtu = PFLOGMTU;
146 	ifp->if_ioctl = pflogioctl;
147 	ifp->if_output = pflogoutput;
148 	ifp->if_start = pflogstart;
149 	ifp->if_type = IFT_PFLOG;
150 #ifndef __NetBSD__
151 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
152 #endif /* !__NetBSD__ */
153 	ifp->if_hdrlen = PFLOG_HDRLEN;
154 	if_attach(ifp);
155 	if_alloc_sadl(ifp);
156 
157 #if NBPFILTER > 0
158 #ifdef __NetBSD__
159 	bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN);
160 #else
161 	bpfattach(&pflogif->sc_if.if_bpf, ifp, DLT_PFLOG, PFLOG_HDRLEN);
162 #endif /* !__NetBSD__ */
163 #endif
164 
165 	s = splnet();
166 	LIST_INSERT_HEAD(&pflogif_list, pflogif, sc_list);
167 	pflogifs[unit] = ifp;
168 	splx(s);
169 
170 	return (0);
171 }
172 
173 int
174 pflog_clone_destroy(struct ifnet *ifp)
175 {
176 	struct pflog_softc	*pflogif = ifp->if_softc;
177 	int			 s;
178 
179 	s = splnet();
180 	pflogifs[pflogif->sc_unit] = NULL;
181 	LIST_REMOVE(pflogif, sc_list);
182 	splx(s);
183 
184 #if NBPFILTER > 0
185 	bpfdetach(ifp);
186 #endif
187 	if_detach(ifp);
188 	free(pflogif, M_DEVBUF);
189 	return (0);
190 }
191 
192 /*
193  * Start output on the pflog interface.
194  */
195 void
196 pflogstart(struct ifnet *ifp)
197 {
198 	struct mbuf *m;
199 	int s;
200 
201 	for (;;) {
202 		s = splnet();
203 		IF_DROP(&ifp->if_snd);
204 		IF_DEQUEUE(&ifp->if_snd, m);
205 		splx(s);
206 
207 		if (m == NULL)
208 			return;
209 		else
210 			m_freem(m);
211 	}
212 }
213 
214 int
215 pflogoutput(struct ifnet *ifp, struct mbuf *m,
216     const struct sockaddr *dst, struct rtentry *rt)
217 {
218 	m_freem(m);
219 	return (0);
220 }
221 
222 /* ARGSUSED */
223 int
224 pflogioctl(struct ifnet *ifp, u_long cmd, void *data)
225 {
226 	switch (cmd) {
227 	case SIOCSIFADDR:
228 	case SIOCAIFADDR:
229 	case SIOCSIFDSTADDR:
230 	case SIOCSIFFLAGS:
231 		if (ifp->if_flags & IFF_UP)
232 			ifp->if_flags |= IFF_RUNNING;
233 		else
234 			ifp->if_flags &= ~IFF_RUNNING;
235 		break;
236 	default:
237 		return (EINVAL);
238 	}
239 
240 	return (0);
241 }
242 
243 int
244 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
245     u_int8_t reason, struct pf_rule *rm, struct pf_rule *am,
246     struct pf_ruleset *ruleset, struct pf_pdesc *pd)
247 {
248 #if NBPFILTER > 0
249 	struct ifnet *ifn;
250 	struct pfloghdr hdr;
251 
252 	if (kif == NULL || m == NULL || rm == NULL || pd == NULL)
253 		return (-1);
254 
255 	if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf)
256 		return (0);
257 
258 	bzero(&hdr, sizeof(hdr));
259 	hdr.length = PFLOG_REAL_HDRLEN;
260 	hdr.af = af;
261 	hdr.action = rm->action;
262 	hdr.reason = reason;
263 	memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));
264 
265 	if (am == NULL) {
266 		hdr.rulenr = htonl(rm->nr);
267 		hdr.subrulenr = -1;
268 	} else {
269 		hdr.rulenr = htonl(am->nr);
270 		hdr.subrulenr = htonl(rm->nr);
271 		if (ruleset != NULL && ruleset->anchor != NULL)
272 			strlcpy(hdr.ruleset, ruleset->anchor->name,
273 			    sizeof(hdr.ruleset));
274 	}
275 	if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done)
276 		pd->lookup.done = pf_socket_lookup(dir, pd);
277 	if (pd->lookup.done > 0) {
278 		hdr.uid = pd->lookup.uid;
279 		hdr.pid = pd->lookup.pid;
280 	} else {
281 		hdr.uid = UID_MAX;
282 		hdr.pid = NO_PID;
283 	}
284 	hdr.rule_uid = rm->cuid;
285 	hdr.rule_pid = rm->cpid;
286 	hdr.dir = dir;
287 
288 #ifdef INET
289 	if (af == AF_INET && dir == PF_OUT) {
290 		struct ip *ip;
291 
292 		ip = mtod(m, struct ip *);
293 		ip->ip_sum = 0;
294 		ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
295 	}
296 #endif /* INET */
297 
298 	ifn->if_opackets++;
299 	ifn->if_obytes += m->m_pkthdr.len;
300 
301 #ifdef __NetBSD__
302 	bpf_mtap2(ifn->if_bpf, &hdr, PFLOG_HDRLEN, m);
303 #else
304 	bpf_mtap_hdr(ifn->if_bpf, (char *)&hdr, PFLOG_HDRLEN, m,
305 	    BPF_DIRECTION_OUT);
306 #endif /* !__NetBSD__ */
307 
308 #endif
309 
310 	return (0);
311 }
312