xref: /netbsd-src/sys/dist/pf/net/if_pflog.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: if_pflog.c,v 1.11 2007/12/11 11:08:19 lukem Exp $	*/
2 /*	$OpenBSD: if_pflog.c,v 1.12 2004/05/19 17:50:51 dhartmei Exp $	*/
3 /*
4  * The authors of this code are John Ioannidis (ji@tla.org),
5  * Angelos D. Keromytis (kermit@csd.uch.gr) and
6  * Niels Provos (provos@physnet.uni-hamburg.de).
7  *
8  * This code was written by John Ioannidis for BSD/OS in Athens, Greece,
9  * in November 1995.
10  *
11  * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
12  * by Angelos D. Keromytis.
13  *
14  * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
15  * and Niels Provos.
16  *
17  * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis
18  * and Niels Provos.
19  * Copyright (c) 2001, Angelos D. Keromytis, Niels Provos.
20  *
21  * Permission to use, copy, and modify this software with or without fee
22  * is hereby granted, provided that this entire notice is included in
23  * all copies of any software which is or includes a copy or
24  * modification of this software.
25  * You may use this code under the GNU public license if you so wish. Please
26  * contribute changes back to the authors under this freer than GPL license
27  * so that we may further the use of strong encryption without limitations to
28  * all.
29  *
30  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
31  * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
32  * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
33  * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
34  * PURPOSE.
35  */
36 
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(0, "$NetBSD: if_pflog.c,v 1.11 2007/12/11 11:08:19 lukem Exp $");
39 
40 #ifdef _KERNEL_OPT
41 #include "opt_inet.h"
42 #endif
43 
44 #include "bpfilter.h"
45 #include "pflog.h"
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/mbuf.h>
50 #include <sys/socket.h>
51 #include <sys/ioctl.h>
52 
53 #include <net/if.h>
54 #include <net/if_types.h>
55 #include <net/route.h>
56 #include <net/bpf.h>
57 
58 #ifdef	INET
59 #include <netinet/in.h>
60 #include <netinet/in_var.h>
61 #include <netinet/in_systm.h>
62 #include <netinet/ip.h>
63 #endif
64 
65 #ifdef INET6
66 #ifndef INET
67 #include <netinet/in.h>
68 #endif
69 #include <netinet6/nd6.h>
70 #endif /* INET6 */
71 
72 #include <net/pfvar.h>
73 #include <net/if_pflog.h>
74 
75 #define PFLOGMTU	(32768 + MHLEN + MLEN)
76 
77 #ifdef PFLOGDEBUG
78 #define DPRINTF(x)    do { if (pflogdebug) printf x ; } while (0)
79 #else
80 #define DPRINTF(x)
81 #endif
82 
83 struct pflog_softc pflogif[NPFLOG];
84 
85 void	pflogattach(int);
86 #ifdef _LKM
87 void	pflogdetach(void);
88 #endif
89 int	pflogoutput(struct ifnet *, struct mbuf *, const struct sockaddr *,
90 	    	       struct rtentry *);
91 int	pflogioctl(struct ifnet *, u_long, void *);
92 void	pflogrtrequest(int, struct rtentry *, struct sockaddr *);
93 void	pflogstart(struct ifnet *);
94 
95 extern int ifqmaxlen;
96 
97 void
98 pflogattach(int npflog)
99 {
100 	struct ifnet *ifp;
101 	int i;
102 
103 	bzero(pflogif, sizeof(pflogif));
104 
105 	for (i = 0; i < NPFLOG; i++) {
106 		ifp = &pflogif[i].sc_if;
107 		snprintf(ifp->if_xname, sizeof ifp->if_xname, "pflog%d", i);
108 		ifp->if_softc = &pflogif[i];
109 		ifp->if_mtu = PFLOGMTU;
110 		ifp->if_ioctl = pflogioctl;
111 		ifp->if_output = pflogoutput;
112 		ifp->if_start = pflogstart;
113 		ifp->if_type = IFT_PFLOG;
114 		ifp->if_snd.ifq_maxlen = ifqmaxlen;
115 		ifp->if_hdrlen = PFLOG_HDRLEN;
116 		if_attach(ifp);
117 		if_alloc_sadl(ifp);
118 
119 #if NBPFILTER > 0
120 #ifdef __OpenBSD__
121 		bpfattach(&pflogif[i].sc_if.if_bpf, ifp, DLT_PFLOG,
122 			  PFLOG_HDRLEN);
123 #else
124 		bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN);
125 #endif
126 #endif
127 	}
128 }
129 
130 #ifdef _LKM
131 void
132 pflogdetach(void)
133 {
134 	struct ifnet *ifp;
135 	int i;
136 
137 	for (i = 0; i < NPFLOG; i++) {
138 		ifp = &pflogif[i].sc_if;
139 		bpfdetach(ifp);
140 		if_detach(ifp);
141 	}
142 }
143 #endif
144 
145 /*
146  * Start output on the pflog interface.
147  */
148 void
149 pflogstart(struct ifnet *ifp)
150 {
151 	struct mbuf *m;
152 	int s;
153 
154 	for (;;) {
155 #ifdef __OpenBSD__
156 		s = splimp();
157 #else
158 		s = splnet();
159 #endif
160 		IF_DROP(&ifp->if_snd);
161 		IF_DEQUEUE(&ifp->if_snd, m);
162 		splx(s);
163 
164 		if (m == NULL)
165 			return;
166 		else
167 			m_freem(m);
168 	}
169 }
170 
171 int
172 pflogoutput(struct ifnet *ifp, struct mbuf *m,
173     const struct sockaddr *dst, struct rtentry *rt)
174 {
175 	m_freem(m);
176 	return (0);
177 }
178 
179 /* ARGSUSED */
180 void
181 pflogrtrequest(int cmd, struct rtentry *rt,
182     struct sockaddr *sa)
183 {
184 	if (rt)
185 		rt->rt_rmx.rmx_mtu = PFLOGMTU;
186 }
187 
188 /* ARGSUSED */
189 int
190 pflogioctl(struct ifnet *ifp, u_long cmd, void *data)
191 {
192 	switch (cmd) {
193 	case SIOCSIFADDR:
194 	case SIOCAIFADDR:
195 	case SIOCSIFDSTADDR:
196 	case SIOCSIFFLAGS:
197 		if (ifp->if_flags & IFF_UP)
198 			ifp->if_flags |= IFF_RUNNING;
199 		else
200 			ifp->if_flags &= ~IFF_RUNNING;
201 		break;
202 	default:
203 		return (EINVAL);
204 	}
205 
206 	return (0);
207 }
208 
209 int
210 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
211     u_int8_t reason, struct pf_rule *rm, struct pf_rule *am,
212     struct pf_ruleset *ruleset)
213 {
214 #if NBPFILTER > 0
215 	struct ifnet *ifn;
216 	struct pfloghdr hdr;
217 #ifndef __NetBSD__
218 	struct mbuf m1;
219 #endif
220 
221 	if (kif == NULL || m == NULL || rm == NULL)
222 		return (-1);
223 
224 	bzero(&hdr, sizeof(hdr));
225 	hdr.length = PFLOG_REAL_HDRLEN;
226 	hdr.af = af;
227 	hdr.action = rm->action;
228 	hdr.reason = reason;
229 	memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));
230 
231 	if (am == NULL) {
232 		hdr.rulenr = htonl(rm->nr);
233 		hdr.subrulenr = -1;
234 	} else {
235 		hdr.rulenr = htonl(am->nr);
236 		hdr.subrulenr = htonl(rm->nr);
237 		if (ruleset != NULL && ruleset->anchor != NULL)
238 			strlcpy(hdr.ruleset, ruleset->anchor->name,
239 			    sizeof(hdr.ruleset));
240 	}
241 	hdr.dir = dir;
242 
243 #ifdef INET
244 	if (af == AF_INET && dir == PF_OUT) {
245 		struct ip *ip;
246 
247 		ip = mtod(m, struct ip *);
248 		ip->ip_sum = 0;
249 		ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
250 	}
251 #endif /* INET */
252 
253 #ifndef __NetBSD__
254 	m1.m_next = m;
255 	m1.m_len = PFLOG_HDRLEN;
256 	m1.m_data = (char *) &hdr;
257 #endif
258 
259 	ifn = &(pflogif[0].sc_if);
260 
261 	if (ifn->if_bpf)
262 #ifndef __NetBSD__
263 		bpf_mtap(ifn->if_bpf, &m1);
264 #else
265 		bpf_mtap2(ifn->if_bpf, &hdr, PFLOG_HDRLEN, m);
266 #endif
267 #endif
268 
269 	return (0);
270 }
271