xref: /netbsd-src/sys/dist/pf/net/if_pflog.c (revision 7f21db1c0118155e0dd40b75182e30c589d9f63e)
1 /*	$NetBSD: if_pflog.c,v 1.16 2010/01/19 22:08:00 pooka Exp $	*/
2 /*	$OpenBSD: if_pflog.c,v 1.24 2007/05/26 17:13:30 jason Exp $	*/
3 
4 /*
5  * The authors of this code are John Ioannidis (ji@tla.org),
6  * Angelos D. Keromytis (kermit@csd.uch.gr) and
7  * Niels Provos (provos@physnet.uni-hamburg.de).
8  *
9  * This code was written by John Ioannidis for BSD/OS in Athens, Greece,
10  * in November 1995.
11  *
12  * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
13  * by Angelos D. Keromytis.
14  *
15  * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
16  * and Niels Provos.
17  *
18  * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis
19  * and Niels Provos.
20  * Copyright (c) 2001, Angelos D. Keromytis, Niels Provos.
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 <sys/cdefs.h>
39 __KERNEL_RCSID(0, "$NetBSD: if_pflog.c,v 1.16 2010/01/19 22:08:00 pooka Exp $");
40 
41 #ifdef _KERNEL_OPT
42 #include "opt_inet.h"
43 #endif
44 
45 #include "pflog.h"
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/mbuf.h>
50 #include <sys/proc.h>
51 #include <sys/socket.h>
52 #include <sys/ioctl.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/pfvar.h>
74 #include <net/if_pflog.h>
75 
76 #define PFLOGMTU	(32768 + MHLEN + MLEN)
77 
78 #ifdef PFLOGDEBUG
79 #define DPRINTF(x)    do { if (pflogdebug) printf x ; } while (0)
80 #else
81 #define DPRINTF(x)
82 #endif
83 
84 void	pflogattach(int);
85 int	pflogoutput(struct ifnet *, struct mbuf *, const struct sockaddr *,
86 	    	       struct rtentry *);
87 int	pflogioctl(struct ifnet *, u_long, void *);
88 void	pflogstart(struct ifnet *);
89 int	pflog_clone_create(struct if_clone *, int);
90 int	pflog_clone_destroy(struct ifnet *);
91 
92 LIST_HEAD(, pflog_softc)	pflogif_list;
93 struct if_clone	pflog_cloner =
94     IF_CLONE_INITIALIZER("pflog", pflog_clone_create, pflog_clone_destroy);
95 
96 struct ifnet	*pflogifs[PFLOGIFS_MAX];	/* for fast access */
97 
98 void
99 pflogattach(int npflog)
100 {
101 	int i;
102 
103 	LIST_INIT(&pflogif_list);
104 	for (i = 0; i < PFLOGIFS_MAX; i++)
105 		pflogifs[i] = NULL;
106 	if_clone_attach(&pflog_cloner);
107 }
108 
109 int
110 pflog_clone_create(struct if_clone *ifc, int unit)
111 {
112 	struct ifnet *ifp;
113 	struct pflog_softc *pflogif;
114 	int s;
115 
116 	if (unit >= PFLOGIFS_MAX)
117 		return (EINVAL);
118 
119 	if ((pflogif = malloc(sizeof(*pflogif), M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
120 		return (ENOMEM);
121 
122 	pflogif->sc_unit = unit;
123 	ifp = &pflogif->sc_if;
124 	snprintf(ifp->if_xname, sizeof ifp->if_xname, "pflog%d", unit);
125 	ifp->if_softc = pflogif;
126 	ifp->if_mtu = PFLOGMTU;
127 	ifp->if_ioctl = pflogioctl;
128 	ifp->if_output = pflogoutput;
129 	ifp->if_start = pflogstart;
130 	ifp->if_type = IFT_PFLOG;
131 #ifndef __NetBSD__
132 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
133 #endif /* !__NetBSD__ */
134 	ifp->if_hdrlen = PFLOG_HDRLEN;
135 	if_attach(ifp);
136 	if_alloc_sadl(ifp);
137 
138 #ifdef __NetBSD__
139 	bpf_ops->bpf_attach(ifp, DLT_PFLOG, PFLOG_HDRLEN, &ifp->if_bpf);
140 #else
141 	bpfattach(&pflogif->sc_if.if_bpf, ifp, DLT_PFLOG, PFLOG_HDRLEN);
142 #endif /* !__NetBSD__ */
143 
144 	s = splnet();
145 	LIST_INSERT_HEAD(&pflogif_list, pflogif, sc_list);
146 	pflogifs[unit] = ifp;
147 	splx(s);
148 
149 	return (0);
150 }
151 
152 int
153 pflog_clone_destroy(struct ifnet *ifp)
154 {
155 	struct pflog_softc	*pflogif = ifp->if_softc;
156 	int			 s;
157 
158 	s = splnet();
159 	pflogifs[pflogif->sc_unit] = NULL;
160 	LIST_REMOVE(pflogif, sc_list);
161 	splx(s);
162 
163 	bpf_ops->bpf_detach(ifp);
164 	if_detach(ifp);
165 	free(pflogif, M_DEVBUF);
166 	return (0);
167 }
168 
169 /*
170  * Start output on the pflog interface.
171  */
172 void
173 pflogstart(struct ifnet *ifp)
174 {
175 	struct mbuf *m;
176 	int s;
177 
178 	for (;;) {
179 		s = splnet();
180 		IF_DROP(&ifp->if_snd);
181 		IF_DEQUEUE(&ifp->if_snd, m);
182 		splx(s);
183 
184 		if (m == NULL)
185 			return;
186 		else
187 			m_freem(m);
188 	}
189 }
190 
191 int
192 pflogoutput(struct ifnet *ifp, struct mbuf *m,
193     const struct sockaddr *dst, struct rtentry *rt)
194 {
195 	m_freem(m);
196 	return (0);
197 }
198 
199 /* ARGSUSED */
200 int
201 pflogioctl(struct ifnet *ifp, u_long cmd, void *data)
202 {
203 	int error = 0;
204 
205 	switch (cmd) {
206 	case SIOCSIFFLAGS:
207 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
208 			break;
209 		/*FALLTHROUGH*/
210 	case SIOCINITIFADDR:
211 	case SIOCAIFADDR:
212 	case SIOCSIFDSTADDR:
213 		if (ifp->if_flags & IFF_UP)
214 			ifp->if_flags |= IFF_RUNNING;
215 		else
216 			ifp->if_flags &= ~IFF_RUNNING;
217 		break;
218 	default:
219 		error = ifioctl_common(ifp, cmd, data);
220 	}
221 
222 	return error;
223 }
224 
225 int
226 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
227     u_int8_t reason, struct pf_rule *rm, struct pf_rule *am,
228     struct pf_ruleset *ruleset, struct pf_pdesc *pd)
229 {
230 	struct ifnet *ifn;
231 	struct pfloghdr hdr;
232 
233 	if (kif == NULL || m == NULL || rm == NULL || pd == NULL)
234 		return (-1);
235 
236 	if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf)
237 		return (0);
238 
239 	bzero(&hdr, sizeof(hdr));
240 	hdr.length = PFLOG_REAL_HDRLEN;
241 	hdr.af = af;
242 	hdr.action = rm->action;
243 	hdr.reason = reason;
244 	memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));
245 
246 	if (am == NULL) {
247 		hdr.rulenr = htonl(rm->nr);
248 		hdr.subrulenr = -1;
249 	} else {
250 		hdr.rulenr = htonl(am->nr);
251 		hdr.subrulenr = htonl(rm->nr);
252 		if (ruleset != NULL && ruleset->anchor != NULL)
253 			strlcpy(hdr.ruleset, ruleset->anchor->name,
254 			    sizeof(hdr.ruleset));
255 	}
256 	if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done)
257 		pd->lookup.done = pf_socket_lookup(dir, pd);
258 	if (pd->lookup.done > 0) {
259 		hdr.uid = pd->lookup.uid;
260 		hdr.pid = pd->lookup.pid;
261 	} else {
262 		hdr.uid = UID_MAX;
263 		hdr.pid = NO_PID;
264 	}
265 	hdr.rule_uid = rm->cuid;
266 	hdr.rule_pid = rm->cpid;
267 	hdr.dir = dir;
268 
269 #ifdef INET
270 	if (af == AF_INET && dir == PF_OUT) {
271 		struct ip *ip;
272 
273 		ip = mtod(m, struct ip *);
274 		ip->ip_sum = 0;
275 		ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
276 	}
277 #endif /* INET */
278 
279 	ifn->if_opackets++;
280 	ifn->if_obytes += m->m_pkthdr.len;
281 
282 #ifdef __NetBSD__
283 	bpf_ops->bpf_mtap2(ifn->if_bpf, &hdr, PFLOG_HDRLEN, m);
284 #else
285 	bpf_mtap_hdr(ifn->if_bpf, (char *)&hdr, PFLOG_HDRLEN, m,
286 	    BPF_DIRECTION_OUT);
287 #endif /* !__NetBSD__ */
288 
289 
290 	return (0);
291 }
292