xref: /dflybsd-src/sys/net/pf/if_pflog.c (revision 88abd8b5763f2e5d4b4db5c5dc1b5bb4c489698b) 
1 /*	$OpenBSD: if_pflog.c,v 1.24 2007/05/26 17:13:30 jason 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) 2004 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 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/in_cksum.h>
44 #include <sys/mbuf.h>
45 #include <sys/proc.h>
46 #include <sys/socket.h>
47 #include <sys/kernel.h>
48 #include <sys/malloc.h>
49 #include <sys/module.h>
50 #include <sys/sockio.h>
51 #include <sys/thread2.h>
52 #include <vm/vm_zone.h>
53 
54 #include <net/if.h>
55 #include <net/if_types.h>
56 #include <net/route.h>
57 #include <net/bpf.h>
58 
59 #ifdef	INET
60 #include <netinet/in.h>
61 #include <netinet/in_var.h>
62 #include <netinet/in_systm.h>
63 #include <netinet/ip.h>
64 #endif
65 
66 #ifdef INET6
67 #ifndef INET
68 #include <netinet/in.h>
69 #endif
70 #include <netinet6/nd6.h>
71 #endif /* INET6 */
72 
73 #include <net/pf/pfvar.h>
74 #include <net/pf/if_pflog.h>
75 
76 #define	PFLOGNAME	"pflog"
77 
78 #define PFLOGMTU	(32768 + MHLEN + MLEN)
79 
80 #ifdef PFLOGDEBUG
81 #define DPRINTF(x)    do { if (pflogdebug) kprintf x ; } while (0)
82 #else
83 #define DPRINTF(x)
84 #endif
85 
86 void	pflogattach(int);
87 int	pflogoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
88 	    	       struct rtentry *);
89 int	pflogioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
90 void	pflogrtrequest(int, struct rtentry *, struct sockaddr *);
91 void	pflogstart(struct ifnet *);
92 int	pflog_clone_create(struct if_clone *, int, caddr_t);
93 void pflog_clone_destroy(struct ifnet *);
94 
95 LIST_HEAD(, pflog_softc)	pflogif_list;
96 struct if_clone	pflog_cloner =
97     IF_CLONE_INITIALIZER("pflog", pflog_clone_create, pflog_clone_destroy, 1, 1);
98 
99 struct ifnet	*pflogifs[PFLOGIFS_MAX];	/* for fast access */
100 
101 void
102 pflogattach(int npflog)
103 {
104 	int	i;
105 	LIST_INIT(&pflogif_list);
106 	for (i = 0; i < PFLOGIFS_MAX; i++)
107 		pflogifs[i] = NULL;
108 	if_clone_attach(&pflog_cloner);
109 }
110 
111 int
112 pflog_clone_create(struct if_clone *ifc, int unit, caddr_t param __unused)
113 {
114 	struct ifnet *ifp;
115 	struct pflog_softc *pflogif;
116 
117 	lwkt_gettoken(&pf_token);
118 
119 	if (unit >= PFLOGIFS_MAX) {
120 		lwkt_reltoken(&pf_token);
121 		return (EINVAL);
122 	}
123 
124 	if ((pflogif = kmalloc(sizeof(*pflogif), M_DEVBUF, M_WAITOK)) == NULL) {
125 		lwkt_reltoken(&pf_token);
126 		return (ENOMEM);
127 	}
128 	bzero(pflogif, sizeof(*pflogif));
129 
130 	pflogif->sc_unit = unit;
131 	lwkt_reltoken(&pf_token);
132 	ifp = &pflogif->sc_if;
133 	ksnprintf(ifp->if_xname, sizeof ifp->if_xname, "pflog%d", unit);
134 	ifp->if_softc = pflogif;
135 	ifp->if_mtu = PFLOGMTU;
136 	ifp->if_ioctl = pflogioctl;
137 	ifp->if_output = pflogoutput;
138 	ifp->if_start = pflogstart;
139 	ifp->if_type = IFT_PFLOG;
140 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
141 	ifp->if_hdrlen = PFLOG_HDRLEN;
142 	if_attach(ifp, NULL);
143 
144 	bpfattach(&pflogif->sc_if, DLT_PFLOG, PFLOG_HDRLEN);
145 	lwkt_gettoken(&pf_token);
146 
147 	crit_enter();
148 	LIST_INSERT_HEAD(&pflogif_list, pflogif, sc_list);
149 	pflogifs[unit] = ifp;
150 	crit_exit();
151 
152 	lwkt_reltoken(&pf_token);
153 	return (0);
154 }
155 
156 void
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 NBPFILTER > 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 
178 /*
179  * Start output on the pflog interface.
180  */
181 void
182 pflogstart(struct ifnet *ifp)
183 {
184 	struct mbuf *m;
185 
186 	ASSERT_LWKT_TOKEN_HELD(&pf_token);
187 
188 	for (;;) {
189 		lwkt_reltoken(&pf_token);
190 		crit_enter();
191 		IF_DROP(&ifp->if_snd);
192 		IF_DEQUEUE(&ifp->if_snd, m);
193 		crit_exit();
194 		lwkt_gettoken(&pf_token);
195 
196 		if (m == NULL)
197 			return;
198 		else
199 			m_freem(m);
200 	}
201 }
202 
203 int
204 pflogoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
205 	struct rtentry *rt)
206 {
207 	m_freem(m);
208 	return (0);
209 }
210 
211 /* ARGSUSED */
212 void
213 pflogrtrequest(int cmd, struct rtentry *rt, struct sockaddr *sa)
214 {
215 	if (rt)
216 		rt->rt_rmx.rmx_mtu = PFLOGMTU;
217 }
218 
219 /* ARGSUSED */
220 int
221 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
222 {
223 
224 	lwkt_gettoken(&pf_token);
225 
226 	switch (cmd) {
227 	case SIOCSIFADDR:
228 	case SIOCAIFADDR:
229 	case SIOCSIFDSTADDR:
230 	case SIOCSIFFLAGS:
231 		lwkt_reltoken(&pf_token);
232 		if (ifp->if_flags & IFF_UP)
233 			ifp->if_flags |= IFF_RUNNING;
234 		else
235 			ifp->if_flags &= ~IFF_RUNNING;
236 		lwkt_gettoken(&pf_token);
237 		break;
238 	default:
239 		lwkt_reltoken(&pf_token);
240 		return (EINVAL);
241 	}
242 
243 	lwkt_reltoken(&pf_token);
244 	return (0);
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 	struct ifnet *ifn = NULL;
253 	struct pfloghdr hdr;
254 
255 	ASSERT_LWKT_TOKEN_HELD(&pf_token);
256 
257 	if (kif == NULL || m == NULL || rm == NULL)
258 		return (-1);
259 
260 	if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf)
261 		return (0);
262 
263 	bzero(&hdr, sizeof(hdr));
264 	hdr.length = PFLOG_REAL_HDRLEN;
265 	hdr.af = af;
266 	hdr.action = rm->action;
267 	hdr.reason = reason;
268 	memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));
269 
270 	if (am == NULL) {
271 		hdr.rulenr = htonl(rm->nr);
272 		hdr.subrulenr = -1;
273 	} else {
274 		hdr.rulenr = htonl(am->nr);
275 		hdr.subrulenr = htonl(rm->nr);
276 		if (ruleset != NULL && ruleset->anchor != NULL)
277 			strlcpy(hdr.ruleset, ruleset->anchor->name,
278 			    sizeof(hdr.ruleset));
279 	}
280 	if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done)
281 		pd->lookup.done = pf_socket_lookup(dir, pd);
282 	if (pd->lookup.done > 0) {
283 		hdr.uid = pd->lookup.uid;
284 		hdr.pid = pd->lookup.pid;
285 	} else {
286 		hdr.uid = UID_MAX;
287 		hdr.pid = NO_PID;
288 	}
289 	hdr.rule_uid = rm->cuid;
290 	hdr.rule_pid = rm->cpid;
291 	hdr.dir = dir;
292 
293 #ifdef INET
294 	if (af == AF_INET) {
295 		struct ip *ip;
296 		ip = mtod(m, struct ip *);
297 		ip->ip_len = htons(ip->ip_len);
298 		ip->ip_off = htons(ip->ip_off);
299 
300 		if (dir == PF_OUT) {
301 			ip->ip_sum = 0;
302 			ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
303 		}
304 	}
305 #endif /* INET */
306 
307 	ifn->if_opackets++;
308 	ifn->if_obytes += m->m_pkthdr.len;
309 	lwkt_reltoken(&pf_token);
310 	bpf_mtap_hdr(ifn->if_bpf, (char *)&hdr, PFLOG_HDRLEN, m,
311 	    BPF_DIRECTION_OUT);
312 	lwkt_gettoken(&pf_token);
313 
314 #ifdef INET
315 	if (af == AF_INET) {
316 		struct ip *ip = mtod(m, struct ip *);
317 
318 		ip->ip_len = ntohs(ip->ip_len);
319 		ip->ip_off = ntohs(ip->ip_off);
320 	}
321 #endif /* INET */
322 
323 	return (0);
324 }
325 
326 static int
327 pflog_modevent(module_t mod, int type, void *data)
328 {
329 	int error = 0;
330 
331 	lwkt_gettoken(&pf_token);
332 
333 	switch (type) {
334 	case MOD_LOAD:
335 		LIST_INIT(&pflogif_list);
336 		lwkt_reltoken(&pf_token);
337 		if_clone_attach(&pflog_cloner);
338 		lwkt_gettoken(&pf_token);
339 		break;
340 
341 	case MOD_UNLOAD:
342 		lwkt_reltoken(&pf_token);
343 		if_clone_detach(&pflog_cloner);
344 		while (!LIST_EMPTY(&pflogif_list)) {
345 			pflog_clone_destroy(
346 				&LIST_FIRST(&pflogif_list)->sc_if);
347 		}
348 		lwkt_gettoken(&pf_token);
349 		break;
350 
351 	default:
352 		error = EINVAL;
353 		break;
354 	}
355 	lwkt_reltoken(&pf_token);
356 	return error;
357 }
358 
359 static moduledata_t pflog_mod = {
360 	"pflog",
361 	pflog_modevent,
362 	0
363 };
364 
365 #define PFLOG_MODVER 1
366 
367 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
368 MODULE_VERSION(pflog, PFLOG_MODVER);
369