xref: /dragonfly/sys/net/pf/if_pflog.c (revision 335b9e93) 
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 __unused);
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, caddr_t param __unused)
114 {
115 	struct ifnet *ifp;
116 	struct pflog_softc *pflogif;
117 
118 	lwkt_gettoken(&pf_token);
119 
120 	if (unit >= PFLOGIFS_MAX) {
121 		lwkt_reltoken(&pf_token);
122 		return (EINVAL);
123 	}
124 
125 	pflogif = kmalloc(sizeof(*pflogif), M_DEVBUF, M_WAITOK | M_ZERO);
126 	pflogif->sc_unit = unit;
127 	lwkt_reltoken(&pf_token);
128 
129 	ifp = &pflogif->sc_if;
130 	if_initname(ifp, ifc->ifc_name, unit);
131 	ifp->if_softc = pflogif;
132 	ifp->if_mtu = PFLOGMTU;
133 	ifp->if_ioctl = pflogioctl;
134 	ifp->if_output = pflogoutput;
135 	ifp->if_start = pflogstart;
136 	ifp->if_type = IFT_PFLOG;
137 	ifq_set_maxlen(&ifp->if_snd, ifqmaxlen);
138 	ifp->if_hdrlen = PFLOG_HDRLEN;
139 
140 	if_attach(ifp, NULL);
141 #if NBPF > 0
142 	bpfattach(&pflogif->sc_if, DLT_PFLOG, PFLOG_HDRLEN);
143 #endif
144 
145 	lwkt_gettoken(&pf_token);
146 	crit_enter();
147 	LIST_INSERT_HEAD(&pflogif_list, pflogif, sc_list);
148 	pflogifs[unit] = ifp;
149 	crit_exit();
150 	lwkt_reltoken(&pf_token);
151 
152 	return (0);
153 }
154 
155 static int
156 pflog_clone_destroy(struct ifnet *ifp)
157 {
158 	struct pflog_softc	*pflogif = ifp->if_softc;
159 
160 	lwkt_gettoken(&pf_token);
161 
162 	crit_enter();
163 	pflogifs[pflogif->sc_unit] = NULL;
164 	LIST_REMOVE(pflogif, sc_list);
165 	crit_exit();
166 
167 	lwkt_reltoken(&pf_token);
168 #if NBPF > 0
169 	bpfdetach(ifp);
170 #endif
171 	if_detach(ifp);
172 	lwkt_gettoken(&pf_token);
173 	kfree(pflogif, M_DEVBUF);
174 	lwkt_reltoken(&pf_token);
175 
176 	return 0;
177 }
178 
179 /*
180  * Start output on the pflog interface.
181  */
182 static void
183 pflogstart(struct ifnet *ifp, struct ifaltq_subque *ifsq)
184 {
185 	struct mbuf *m;
186 
187 	ASSERT_ALTQ_SQ_DEFAULT(ifp, ifsq);
188 	ASSERT_LWKT_TOKEN_HELD(&pf_token);
189 
190 	for (;;) {
191 		m = ifsq_dequeue(ifsq);
192 		if (m == NULL)
193 			return;
194 		else
195 			m_freem(m);
196 	}
197 }
198 
199 static int
200 pflogoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
201 	    struct rtentry *rt)
202 {
203 	m_freem(m);
204 	return (0);
205 }
206 
207 static int
208 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data __unused,
209 	   struct ucred *cr __unused)
210 {
211 
212 	lwkt_gettoken(&pf_token);
213 
214 	switch (cmd) {
215 	case SIOCSIFFLAGS:
216 		lwkt_reltoken(&pf_token);
217 		if (ifp->if_flags & IFF_UP)
218 			ifp->if_flags |= IFF_RUNNING;
219 		else
220 			ifp->if_flags &= ~IFF_RUNNING;
221 		lwkt_gettoken(&pf_token);
222 		break;
223 	default:
224 		lwkt_reltoken(&pf_token);
225 		return (EINVAL);
226 	}
227 
228 	lwkt_reltoken(&pf_token);
229 	return (0);
230 }
231 
232 int
233 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
234 	     u_int8_t reason, struct pf_rule *rm, struct pf_rule *am,
235 	     struct pf_ruleset *ruleset, struct pf_pdesc *pd)
236 {
237 	struct ifnet *ifn = NULL;
238 	struct pfloghdr hdr;
239 
240 	ASSERT_LWKT_TOKEN_HELD(&pf_token);
241 
242 	if (kif == NULL || m == NULL || rm == NULL)
243 		return (-1);
244 
245 	if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf)
246 		return (0);
247 
248 	bzero(&hdr, sizeof(hdr));
249 	hdr.length = PFLOG_REAL_HDRLEN;
250 	hdr.af = af;
251 	hdr.action = rm->action;
252 	hdr.reason = reason;
253 	memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));
254 
255 	if (am == NULL) {
256 		hdr.rulenr = htonl(rm->nr);
257 		hdr.subrulenr = -1;
258 	} else {
259 		hdr.rulenr = htonl(am->nr);
260 		hdr.subrulenr = htonl(rm->nr);
261 		if (ruleset != NULL && ruleset->anchor != NULL)
262 			strlcpy(hdr.ruleset, ruleset->anchor->name,
263 			    sizeof(hdr.ruleset));
264 	}
265 	if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done)
266 		pd->lookup.done = pf_socket_lookup(dir, pd);
267 	if (pd->lookup.done > 0) {
268 		hdr.uid = pd->lookup.uid;
269 		hdr.pid = pd->lookup.pid;
270 	} else {
271 		hdr.uid = UID_MAX;
272 		hdr.pid = NO_PID;
273 	}
274 	hdr.rule_uid = rm->cuid;
275 	hdr.rule_pid = rm->cpid;
276 	hdr.dir = dir;
277 
278 #ifdef INET
279 	if (af == AF_INET) {
280 		struct ip *ip;
281 		ip = mtod(m, struct ip *);
282 		ip->ip_len = htons(ip->ip_len);
283 		ip->ip_off = htons(ip->ip_off);
284 
285 		if (dir == PF_OUT) {
286 			ip->ip_sum = 0;
287 			ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
288 		}
289 	}
290 #endif /* INET */
291 
292 	IFNET_STAT_INC(ifn, opackets, 1);
293 	IFNET_STAT_INC(ifn, obytes, m->m_pkthdr.len);
294 	if (ifn->if_bpf) {
295 		bpf_gettoken();
296 		if (ifn->if_bpf) {
297 			bpf_mtap_hdr(ifn->if_bpf, (char *)&hdr, PFLOG_HDRLEN, m,
298 			    BPF_DIRECTION_OUT);
299 		}
300 		bpf_reltoken();
301 	}
302 
303 #ifdef INET
304 	if (af == AF_INET) {
305 		struct ip *ip = mtod(m, struct ip *);
306 
307 		ip->ip_len = ntohs(ip->ip_len);
308 		ip->ip_off = ntohs(ip->ip_off);
309 	}
310 #endif /* INET */
311 
312 	return (0);
313 }
314 
315 static int
316 pflog_modevent(module_t mod, int type, void *data)
317 {
318 	int error = 0;
319 
320 	struct pflog_softc *pflogif, *tmp;
321 
322 	lwkt_gettoken(&pf_token);
323 
324 	switch (type) {
325 	case MOD_LOAD:
326 		lwkt_reltoken(&pf_token);
327 		pflogattach();
328 		lwkt_gettoken(&pf_token);
329 		break;
330 
331 	case MOD_UNLOAD:
332 		lwkt_reltoken(&pf_token);
333 		if_clone_detach(&pflog_cloner);
334 		LIST_FOREACH_MUTABLE(pflogif, &pflogif_list, sc_list, tmp)
335 			pflog_clone_destroy(&pflogif->sc_if);
336 		lwkt_gettoken(&pf_token);
337 		break;
338 
339 	default:
340 		error = EINVAL;
341 		break;
342 	}
343 	lwkt_reltoken(&pf_token);
344 	return error;
345 }
346 
347 static moduledata_t pflog_mod = {
348 	"pflog",
349 	pflog_modevent,
350 	0
351 };
352 
353 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
354 MODULE_VERSION(pflog, PFLOG_MODVER);
355 /* Do not run before pf is initialized. */
356 MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER);
357