xref: /dflybsd-src/sys/net/pf/if_pflog.c (revision 211d4362597aee676ecea315377d5cb13da26bb5) 
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 
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 
53 #include <net/if.h>
54 #include <net/if_types.h>
55 #include <net/ifq_var.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 int	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),
125 		M_DEVBUF, M_WAITOK|M_ZERO)) == NULL) {
126 		lwkt_reltoken(&pf_token);
127 		return (ENOMEM);
128 	}
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 	ifq_set_maxlen(&ifp->if_snd, 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 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 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 	return 0;
178 }
179 
180 /*
181  * Start output on the pflog interface.
182  */
183 void
184 pflogstart(struct ifnet *ifp)
185 {
186 	struct mbuf *m;
187 
188 	ASSERT_LWKT_TOKEN_HELD(&pf_token);
189 
190 	for (;;) {
191 		m = ifq_dequeue(&ifp->if_snd, NULL);
192 		if (m == NULL)
193 			return;
194 		else
195 			m_freem(m);
196 	}
197 }
198 
199 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 /* ARGSUSED */
208 void
209 pflogrtrequest(int cmd, struct rtentry *rt, struct sockaddr *sa)
210 {
211 	if (rt)
212 		rt->rt_rmx.rmx_mtu = PFLOGMTU;
213 }
214 
215 /* ARGSUSED */
216 int
217 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
218 {
219 
220 	lwkt_gettoken(&pf_token);
221 
222 	switch (cmd) {
223 	case SIOCSIFFLAGS:
224 		lwkt_reltoken(&pf_token);
225 		if (ifp->if_flags & IFF_UP)
226 			ifp->if_flags |= IFF_RUNNING;
227 		else
228 			ifp->if_flags &= ~IFF_RUNNING;
229 		lwkt_gettoken(&pf_token);
230 		break;
231 	default:
232 		lwkt_reltoken(&pf_token);
233 		return (EINVAL);
234 	}
235 
236 	lwkt_reltoken(&pf_token);
237 	return (0);
238 }
239 
240 int
241 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
242     u_int8_t reason, struct pf_rule *rm, struct pf_rule *am,
243     struct pf_ruleset *ruleset, struct pf_pdesc *pd)
244 {
245 	struct ifnet *ifn = NULL;
246 	struct pfloghdr hdr;
247 
248 	ASSERT_LWKT_TOKEN_HELD(&pf_token);
249 
250 	if (kif == NULL || m == NULL || rm == NULL)
251 		return (-1);
252 
253 	if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf)
254 		return (0);
255 
256 	bzero(&hdr, sizeof(hdr));
257 	hdr.length = PFLOG_REAL_HDRLEN;
258 	hdr.af = af;
259 	hdr.action = rm->action;
260 	hdr.reason = reason;
261 	memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));
262 
263 	if (am == NULL) {
264 		hdr.rulenr = htonl(rm->nr);
265 		hdr.subrulenr = -1;
266 	} else {
267 		hdr.rulenr = htonl(am->nr);
268 		hdr.subrulenr = htonl(rm->nr);
269 		if (ruleset != NULL && ruleset->anchor != NULL)
270 			strlcpy(hdr.ruleset, ruleset->anchor->name,
271 			    sizeof(hdr.ruleset));
272 	}
273 	if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done)
274 		pd->lookup.done = pf_socket_lookup(dir, pd);
275 	if (pd->lookup.done > 0) {
276 		hdr.uid = pd->lookup.uid;
277 		hdr.pid = pd->lookup.pid;
278 	} else {
279 		hdr.uid = UID_MAX;
280 		hdr.pid = NO_PID;
281 	}
282 	hdr.rule_uid = rm->cuid;
283 	hdr.rule_pid = rm->cpid;
284 	hdr.dir = dir;
285 
286 #ifdef INET
287 	if (af == AF_INET) {
288 		struct ip *ip;
289 		ip = mtod(m, struct ip *);
290 		ip->ip_len = htons(ip->ip_len);
291 		ip->ip_off = htons(ip->ip_off);
292 
293 		if (dir == PF_OUT) {
294 			ip->ip_sum = 0;
295 			ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
296 		}
297 	}
298 #endif /* INET */
299 
300 	ifn->if_opackets++;
301 	ifn->if_obytes += m->m_pkthdr.len;
302 	if (ifn->if_bpf) {
303 		bpf_gettoken();
304 		if (ifn->if_bpf) {
305 			bpf_mtap_hdr(ifn->if_bpf, (char *)&hdr, PFLOG_HDRLEN, m,
306 			    BPF_DIRECTION_OUT);
307 		}
308 		bpf_reltoken();
309 	}
310 
311 #ifdef INET
312 	if (af == AF_INET) {
313 		struct ip *ip = mtod(m, struct ip *);
314 
315 		ip->ip_len = ntohs(ip->ip_len);
316 		ip->ip_off = ntohs(ip->ip_off);
317 	}
318 #endif /* INET */
319 
320 	return (0);
321 }
322 
323 static int
324 pflog_modevent(module_t mod, int type, void *data)
325 {
326 	int error = 0;
327 
328 	struct pflog_softc *pflogif, *tmp;
329 
330 	lwkt_gettoken(&pf_token);
331 
332 	switch (type) {
333 	case MOD_LOAD:
334 		LIST_INIT(&pflogif_list);
335 		lwkt_reltoken(&pf_token);
336 		if_clone_attach(&pflog_cloner);
337 		lwkt_gettoken(&pf_token);
338 		break;
339 
340 	case MOD_UNLOAD:
341 		lwkt_reltoken(&pf_token);
342 		if_clone_detach(&pflog_cloner);
343 		LIST_FOREACH_MUTABLE(pflogif, &pflogif_list, sc_list, tmp) {
344 			pflog_clone_destroy(&pflogif->sc_if);
345 		}
346 		lwkt_gettoken(&pf_token);
347 		break;
348 
349 	default:
350 		error = EINVAL;
351 		break;
352 	}
353 	lwkt_reltoken(&pf_token);
354 	return error;
355 }
356 
357 static moduledata_t pflog_mod = {
358 	"pflog",
359 	pflog_modevent,
360 	0
361 };
362 
363 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
364 MODULE_VERSION(pflog, PFLOG_MODVER);
365