xref: /dragonfly/sys/net/pf/if_pflog.c (revision f0e61bb7) 
1 /*	$OpenBSD: if_pflog.c,v 1.27 2007/12/20 02:53:02 brad Exp $	*/
2 /*
3  * The authors of this code are John Ioannidis (ji@tla.org),
4  * Angelos D. Keromytis (kermit@csd.uch.gr) and
5  * Niels Provos (provos@physnet.uni-hamburg.de).
6  *
7  * This code was written by John Ioannidis for BSD/OS in Athens, Greece,
8  * in November 1995.
9  *
10  * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
11  * by Angelos D. Keromytis.
12  *
13  * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
14  * and Niels Provos.
15  *
16  * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis
17  * and Niels Provos.
18  * Copyright (c) 2001, Angelos D. Keromytis, Niels Provos.
19  *
20  * Copyright (c) 2010 The DragonFly Project.  All rights reserved.
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 "opt_inet.h"
39 #include "opt_inet6.h"
40 #include "use_bpf.h"
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/in_cksum.h>
45 #include <sys/mbuf.h>
46 #include <sys/proc.h>
47 #include <sys/socket.h>
48 #include <sys/kernel.h>
49 #include <sys/malloc.h>
50 #include <sys/module.h>
51 #include <sys/sockio.h>
52 #include <sys/thread2.h>
53 
54 #include <net/if.h>
55 #include <net/if_types.h>
56 #include <net/ifq_var.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/pf/pfvar.h>
75 #include <net/pf/if_pflog.h>
76 
77 #define	PFLOGNAME	"pflog"
78 
79 #define PFLOGMTU	(32768 + MHLEN + MLEN)
80 
81 #ifdef PFLOGDEBUG
82 #define DPRINTF(x)	do { if (pflogdebug) kprintf x ; } while (0)
83 #else
84 #define DPRINTF(x)
85 #endif
86 
87 static void	pflogattach(void);
88 static int	pflogoutput(struct ifnet *, struct mbuf *,
89 		    struct sockaddr *, struct rtentry *);
90 static int	pflogioctl(struct ifnet *, u_long, caddr_t __unused,
91 		    struct ucred * __unused);
92 static void	pflogstart(struct ifnet *, struct ifaltq_subque *);
93 static int	pflog_clone_create(struct if_clone *, int, caddr_t, caddr_t);
94 static int	pflog_clone_destroy(struct ifnet *);
95 
96 static struct if_clone pflog_cloner = IF_CLONE_INITIALIZER(
97     PFLOGNAME, pflog_clone_create, pflog_clone_destroy, 1, 1);
98 
99 static LIST_HEAD(, pflog_softc) pflogif_list;
100 static struct ifnet *pflogifs[PFLOGIFS_MAX]; /* for fast access */
101 
102 static void
103 pflogattach(void)
104 {
105 	int	i;
106 	LIST_INIT(&pflogif_list);
107 	for (i = 0; i < PFLOGIFS_MAX; i++)
108 		pflogifs[i] = NULL;
109 	if_clone_attach(&pflog_cloner);
110 }
111 
112 static int
113 pflog_clone_create(struct if_clone *ifc, int unit,
114 		   caddr_t params __unused, caddr_t data __unused)
115 {
116 	struct ifnet *ifp;
117 	struct pflog_softc *pflogif;
118 
119 	lwkt_gettoken(&pf_token);
120 
121 	if (unit >= PFLOGIFS_MAX) {
122 		lwkt_reltoken(&pf_token);
123 		return (EINVAL);
124 	}
125 
126 	pflogif = kmalloc(sizeof(*pflogif), M_DEVBUF, M_WAITOK | M_ZERO);
127 	pflogif->sc_unit = unit;
128 	lwkt_reltoken(&pf_token);
129 
130 	ifp = &pflogif->sc_if;
131 	if_initname(ifp, ifc->ifc_name, unit);
132 	ifp->if_softc = pflogif;
133 	ifp->if_mtu = PFLOGMTU;
134 	ifp->if_ioctl = pflogioctl;
135 	ifp->if_output = pflogoutput;
136 	ifp->if_start = pflogstart;
137 	ifp->if_type = IFT_PFLOG;
138 	ifq_set_maxlen(&ifp->if_snd, ifqmaxlen);
139 	ifp->if_hdrlen = PFLOG_HDRLEN;
140 
141 	if_attach(ifp, NULL);
142 #if NBPF > 0
143 	bpfattach(&pflogif->sc_if, DLT_PFLOG, PFLOG_HDRLEN);
144 #endif
145 
146 	lwkt_gettoken(&pf_token);
147 	crit_enter();
148 	LIST_INSERT_HEAD(&pflogif_list, pflogif, sc_list);
149 	pflogifs[unit] = ifp;
150 	crit_exit();
151 	lwkt_reltoken(&pf_token);
152 
153 	return (0);
154 }
155 
156 static int
157 pflog_clone_destroy(struct ifnet *ifp)
158 {
159 	struct pflog_softc	*pflogif = ifp->if_softc;
160 
161 	lwkt_gettoken(&pf_token);
162 
163 	crit_enter();
164 	pflogifs[pflogif->sc_unit] = NULL;
165 	LIST_REMOVE(pflogif, sc_list);
166 	crit_exit();
167 
168 	lwkt_reltoken(&pf_token);
169 #if NBPF > 0
170 	bpfdetach(ifp);
171 #endif
172 	if_detach(ifp);
173 	lwkt_gettoken(&pf_token);
174 	kfree(pflogif, M_DEVBUF);
175 	lwkt_reltoken(&pf_token);
176 
177 	return 0;
178 }
179 
180 /*
181  * Start output on the pflog interface.
182  */
183 static void
184 pflogstart(struct ifnet *ifp, struct ifaltq_subque *ifsq)
185 {
186 	struct mbuf *m;
187 
188 	ASSERT_ALTQ_SQ_DEFAULT(ifp, ifsq);
189 	ASSERT_LWKT_TOKEN_HELD(&pf_token);
190 
191 	for (;;) {
192 		m = ifsq_dequeue(ifsq);
193 		if (m == NULL)
194 			return;
195 		else
196 			m_freem(m);
197 	}
198 }
199 
200 static int
201 pflogoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
202 	    struct rtentry *rt)
203 {
204 	m_freem(m);
205 	return (0);
206 }
207 
208 static int
209 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data __unused,
210 	   struct ucred *cr __unused)
211 {
212 
213 	lwkt_gettoken(&pf_token);
214 
215 	switch (cmd) {
216 	case SIOCSIFFLAGS:
217 		lwkt_reltoken(&pf_token);
218 		if (ifp->if_flags & IFF_UP)
219 			ifp->if_flags |= IFF_RUNNING;
220 		else
221 			ifp->if_flags &= ~IFF_RUNNING;
222 		lwkt_gettoken(&pf_token);
223 		break;
224 	default:
225 		lwkt_reltoken(&pf_token);
226 		return (EINVAL);
227 	}
228 
229 	lwkt_reltoken(&pf_token);
230 	return (0);
231 }
232 
233 int
234 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
235 	     u_int8_t reason, struct pf_rule *rm, struct pf_rule *am,
236 	     struct pf_ruleset *ruleset, struct pf_pdesc *pd)
237 {
238 	struct ifnet *ifn = NULL;
239 	struct pfloghdr hdr;
240 
241 	ASSERT_LWKT_TOKEN_HELD(&pf_token);
242 
243 	if (kif == NULL || m == NULL || rm == NULL)
244 		return (-1);
245 
246 	if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf)
247 		return (0);
248 
249 	bzero(&hdr, sizeof(hdr));
250 	hdr.length = PFLOG_REAL_HDRLEN;
251 	hdr.af = af;
252 	hdr.action = rm->action;
253 	hdr.reason = reason;
254 	memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));
255 
256 	if (am == NULL) {
257 		hdr.rulenr = htonl(rm->nr);
258 		hdr.subrulenr = -1;
259 	} else {
260 		hdr.rulenr = htonl(am->nr);
261 		hdr.subrulenr = htonl(rm->nr);
262 		if (ruleset != NULL && ruleset->anchor != NULL)
263 			strlcpy(hdr.ruleset, ruleset->anchor->name,
264 			    sizeof(hdr.ruleset));
265 	}
266 	if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done)
267 		pd->lookup.done = pf_socket_lookup(dir, pd);
268 	if (pd->lookup.done > 0) {
269 		hdr.uid = pd->lookup.uid;
270 		hdr.pid = pd->lookup.pid;
271 	} else {
272 		hdr.uid = UID_MAX;
273 		hdr.pid = NO_PID;
274 	}
275 	hdr.rule_uid = rm->cuid;
276 	hdr.rule_pid = rm->cpid;
277 	hdr.dir = dir;
278 
279 #ifdef INET
280 	if (af == AF_INET) {
281 		struct ip *ip;
282 		ip = mtod(m, struct ip *);
283 
284 		if (dir == PF_OUT) {
285 			ip->ip_sum = 0;
286 			ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
287 		}
288 	}
289 #endif /* INET */
290 
291 	IFNET_STAT_INC(ifn, opackets, 1);
292 	IFNET_STAT_INC(ifn, obytes, m->m_pkthdr.len);
293 	if (ifn->if_bpf) {
294 		bpf_gettoken();
295 		if (ifn->if_bpf) {
296 			bpf_mtap_hdr(ifn->if_bpf, (char *)&hdr, PFLOG_HDRLEN, m,
297 			    BPF_DIRECTION_OUT);
298 		}
299 		bpf_reltoken();
300 	}
301 
302 	return (0);
303 }
304 
305 static int
306 pflog_modevent(module_t mod, int type, void *data)
307 {
308 	int error = 0;
309 
310 	struct pflog_softc *pflogif, *tmp;
311 
312 	lwkt_gettoken(&pf_token);
313 
314 	switch (type) {
315 	case MOD_LOAD:
316 		lwkt_reltoken(&pf_token);
317 		pflogattach();
318 		lwkt_gettoken(&pf_token);
319 		break;
320 
321 	case MOD_UNLOAD:
322 		lwkt_reltoken(&pf_token);
323 		if_clone_detach(&pflog_cloner);
324 		LIST_FOREACH_MUTABLE(pflogif, &pflogif_list, sc_list, tmp)
325 			pflog_clone_destroy(&pflogif->sc_if);
326 		lwkt_gettoken(&pf_token);
327 		break;
328 
329 	default:
330 		error = EINVAL;
331 		break;
332 	}
333 	lwkt_reltoken(&pf_token);
334 	return error;
335 }
336 
337 static moduledata_t pflog_mod = {
338 	"pflog",
339 	pflog_modevent,
340 	0
341 };
342 
343 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
344 MODULE_VERSION(pflog, PFLOG_MODVER);
345 /* Do not run before pf is initialized. */
346 MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER);
347