xref: /dragonfly/sys/net/pf/if_pflog.c (revision b7367ef6) 
1 /*	$FreeBSD: src/sys/contrib/pf/net/if_pflog.c,v 1.9 2004/06/22 20:13:24 brooks Exp $	*/
2 /*	$OpenBSD: if_pflog.c,v 1.11 2003/12/31 11:18:25 cedric Exp $	*/
3 /*	$DragonFly: src/sys/net/pf/if_pflog.c,v 1.6 2006/12/22 23:44:57 swildner Exp $ */
4 
5 /*
6  * The authors of this code are John Ioannidis (ji@tla.org),
7  * Angelos D. Keromytis (kermit@csd.uch.gr) and
8  * Niels Provos (provos@physnet.uni-hamburg.de).
9  *
10  * This code was written by John Ioannidis for BSD/OS in Athens, Greece,
11  * in November 1995.
12  *
13  * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
14  * by Angelos D. Keromytis.
15  *
16  * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
17  * and Niels Provos.
18  *
19  * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis
20  * and Niels Provos.
21  * Copyright (c) 2001, Angelos D. Keromytis, Niels Provos.
22  *
23  * Copyright (c) 2004 The DragonFly Project.  All rights reserved.
24  *
25  * Permission to use, copy, and modify this software with or without fee
26  * is hereby granted, provided that this entire notice is included in
27  * all copies of any software which is or includes a copy or
28  * modification of this software.
29  * You may use this code under the GNU public license if you so wish. Please
30  * contribute changes back to the authors under this freer than GPL license
31  * so that we may further the use of strong encryption without limitations to
32  * all.
33  *
34  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
35  * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
36  * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
37  * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
38  * PURPOSE.
39  */
40 
41 #include "opt_inet.h"
42 #include "opt_inet6.h"
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/in_cksum.h>
47 #include <sys/mbuf.h>
48 #include <sys/socket.h>
49 #include <sys/kernel.h>
50 #include <sys/malloc.h>
51 #include <sys/module.h>
52 #include <sys/sockio.h>
53 #include <sys/thread2.h>
54 #include <vm/vm_zone.h>
55 
56 #include <net/if.h>
57 #include <net/if_types.h>
58 #include <net/route.h>
59 #include <net/bpf.h>
60 
61 #ifdef	INET
62 #include <netinet/in.h>
63 #include <netinet/in_var.h>
64 #include <netinet/in_systm.h>
65 #include <netinet/ip.h>
66 #endif
67 
68 #ifdef INET6
69 #ifndef INET
70 #include <netinet/in.h>
71 #endif
72 #include <netinet6/nd6.h>
73 #endif /* INET6 */
74 
75 #include <net/pf/pfvar.h>
76 #include <net/pf/if_pflog.h>
77 
78 #define	PFLOGNAME	"pflog"
79 
80 #define PFLOGMTU	(32768 + MHLEN + MLEN)
81 
82 #ifdef PFLOGDEBUG
83 #define DPRINTF(x)    do { if (pflogdebug) kprintf x ; } while (0)
84 #else
85 #define DPRINTF(x)
86 #endif
87 
88 
89 static void	pflog_clone_destroy(struct ifnet *);
90 static int	pflog_clone_create(struct if_clone *, int);
91 int	pflogoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
92 	    	       struct rtentry *);
93 int	pflogioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
94 void	pflogrtrequest(int, struct rtentry *, struct sockaddr *);
95 void	pflogstart(struct ifnet *);
96 
97 static MALLOC_DEFINE(M_PFLOG, PFLOGNAME, "Packet Filter Logging Interface");
98 static LIST_HEAD(pflog_list, pflog_softc) pflog_list;
99 struct if_clone pflog_cloner = IF_CLONE_INITIALIZER("pflog", pflog_clone_create,
100 	    pflog_clone_destroy, 1, 1);
101 
102 static void
103 pflog_clone_destroy(struct ifnet *ifp)
104 {
105 	struct pflog_softc *sc;
106 
107 	sc = ifp->if_softc;
108 
109 	/*
110 	 * Do we really need this?
111 	 */
112 	IF_DRAIN(&ifp->if_snd);
113 
114 	bpfdetach(ifp);
115 	if_detach(ifp);
116 	LIST_REMOVE(sc, sc_next);
117 	kfree(sc, M_PFLOG);
118 }
119 
120 static int
121 pflog_clone_create(struct if_clone *ifc, int unit)
122 {
123 	struct pflog_softc *sc;
124 
125 	MALLOC(sc, struct pflog_softc *, sizeof(*sc), M_PFLOG, M_WAITOK|M_ZERO);
126 
127 	if_initname(&sc->sc_if, ifc->ifc_name, unit);
128         sc->sc_if.if_mtu = PFLOGMTU;
129         sc->sc_if.if_ioctl = pflogioctl;
130         sc->sc_if.if_output = pflogoutput;
131         sc->sc_if.if_start = pflogstart;
132         sc->sc_if.if_type = IFT_PFLOG;
133         sc->sc_if.if_snd.ifq_maxlen = ifqmaxlen;
134         sc->sc_if.if_hdrlen = PFLOG_HDRLEN;
135         sc->sc_if.if_softc = sc;
136         if_attach(&sc->sc_if, NULL);
137 
138         LIST_INSERT_HEAD(&pflog_list, sc, sc_next);
139 	bpfattach(&sc->sc_if, DLT_PFLOG, PFLOG_HDRLEN);
140 
141         return (0);
142 }
143 
144 /*
145  * Start output on the pflog interface.
146  */
147 void
148 pflogstart(struct ifnet *ifp)
149 {
150 	crit_enter();
151 	IF_DROP(&ifp->if_snd);
152 	IF_DRAIN(&ifp->if_snd);
153 	crit_exit();
154 }
155 
156 int
157 pflogoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
158 	struct rtentry *rt)
159 {
160 	m_freem(m);
161 	return (0);
162 }
163 
164 /* ARGSUSED */
165 void
166 pflogrtrequest(int cmd, struct rtentry *rt, struct sockaddr *sa)
167 {
168 	if (rt)
169 		rt->rt_rmx.rmx_mtu = PFLOGMTU;
170 }
171 
172 /* ARGSUSED */
173 int
174 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
175 {
176 	switch (cmd) {
177 	case SIOCSIFADDR:
178 	case SIOCAIFADDR:
179 	case SIOCSIFDSTADDR:
180 	case SIOCSIFFLAGS:
181 		if (ifp->if_flags & IFF_UP)
182 			ifp->if_flags |= IFF_RUNNING;
183 		else
184 			ifp->if_flags &= ~IFF_RUNNING;
185 		break;
186 	default:
187 		return (EINVAL);
188 	}
189 
190 	return (0);
191 }
192 
193 int
194 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
195     u_int8_t reason, struct pf_rule *rm, struct pf_rule *am,
196     struct pf_ruleset *ruleset)
197 {
198 	struct ifnet *ifn;
199 	struct pfloghdr hdr;
200 	struct mbuf m1;
201 
202 	if (kif == NULL || m == NULL || rm == NULL)
203 		return (-1);
204 
205 	bzero(&hdr, sizeof(hdr));
206 	hdr.length = PFLOG_REAL_HDRLEN;
207 	hdr.af = af;
208 	hdr.action = rm->action;
209 	hdr.reason = reason;
210 	memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));
211 
212 	if (am == NULL) {
213 		hdr.rulenr = htonl(rm->nr);
214 		hdr.subrulenr = -1;
215 	} else {
216 		hdr.rulenr = htonl(am->nr);
217 		hdr.subrulenr = htonl(rm->nr);
218 		if (ruleset != NULL)
219 			memcpy(hdr.ruleset, ruleset->name,
220 			    sizeof(hdr.ruleset));
221 
222 
223 	}
224 	hdr.dir = dir;
225 
226 #ifdef INET
227 	if (af == AF_INET) {
228 		struct ip *ip = mtod(m, struct ip *);
229 
230 		ip->ip_len = htons(ip->ip_len);
231 		ip->ip_off = htons(ip->ip_off);
232 
233 		if (dir == PF_OUT) {
234 			ip->ip_sum = 0;
235 			ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
236 		}
237 	}
238 #endif /* INET */
239 
240 	m1.m_next = m;
241 	m1.m_len = PFLOG_HDRLEN;
242 	m1.m_data = (char *) &hdr;
243 
244 	KASSERT((!LIST_EMPTY(&pflog_list)), ("pflog: no interface"));
245 	ifn = &LIST_FIRST(&pflog_list)->sc_if;
246 
247 	BPF_MTAP(ifn, &m1);
248 
249 #ifdef INET
250 	if (af == AF_INET) {
251 		struct ip *ip = mtod(m, struct ip *);
252 
253 		ip->ip_len = ntohs(ip->ip_len);
254 		ip->ip_off = ntohs(ip->ip_off);
255 	}
256 #endif /* INET */
257 
258 	return (0);
259 }
260 
261 static int
262 pflog_modevent(module_t mod, int type, void *data)
263 {
264 	int error = 0;
265 
266 	switch (type) {
267 	case MOD_LOAD:
268 		LIST_INIT(&pflog_list);
269 		if_clone_attach(&pflog_cloner);
270 		break;
271 
272 	case MOD_UNLOAD:
273 		if_clone_detach(&pflog_cloner);
274 		while (!LIST_EMPTY(&pflog_list))
275 			pflog_clone_destroy(
276 				&LIST_FIRST(&pflog_list)->sc_if);
277 		break;
278 
279 	default:
280 		error = EINVAL;
281 		break;
282 	}
283 
284 	return error;
285 }
286 
287 static moduledata_t pflog_mod = {
288 	"pflog",
289 	pflog_modevent,
290 	0
291 };
292 
293 #define PFLOG_MODVER 1
294 
295 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
296 MODULE_VERSION(pflog, PFLOG_MODVER);
297