1 /*-
2 * The authors of this code are John Ioannidis (ji@tla.org),
3 * Angelos D. Keromytis (kermit@csd.uch.gr) and
4 * Niels Provos (provos@physnet.uni-hamburg.de).
5 *
6 * This code was written by John Ioannidis for BSD/OS in Athens, Greece,
7 * in November 1995.
8 *
9 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
10 * by Angelos D. Keromytis.
11 *
12 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
13 * and Niels Provos.
14 *
15 * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis
16 * and Niels Provos.
17 * Copyright (c) 2001, Angelos D. Keromytis, Niels Provos.
18 *
19 * Permission to use, copy, and modify this software with or without fee
20 * is hereby granted, provided that this entire notice is included in
21 * all copies of any software which is or includes a copy or
22 * modification of this software.
23 * You may use this code under the GNU public license if you so wish. Please
24 * contribute changes back to the authors under this freer than GPL license
25 * so that we may further the use of strong encryption without limitations to
26 * all.
27 *
28 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
29 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
30 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
31 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
32 * PURPOSE.
33 *
34 * $OpenBSD: if_pflog.c,v 1.26 2007/10/18 21:58:18 mpf Exp $
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39
40 #include "opt_inet.h"
41 #include "opt_inet6.h"
42 #include "opt_bpf.h"
43 #include "opt_pf.h"
44
45 #include <sys/param.h>
46 #include <sys/kernel.h>
47 #include <sys/mbuf.h>
48 #include <sys/module.h>
49 #include <sys/proc.h>
50 #include <sys/socket.h>
51 #include <sys/sockio.h>
52
53 #include <net/bpf.h>
54 #include <net/if.h>
55 #include <net/if_var.h>
56 #include <net/if_clone.h>
57 #include <net/if_pflog.h>
58 #include <net/if_types.h>
59 #include <net/vnet.h>
60 #include <net/pfvar.h>
61
62 #if defined(INET) || defined(INET6)
63 #include <netinet/in.h>
64 #endif
65 #ifdef INET
66 #include <netinet/in_var.h>
67 #include <netinet/ip.h>
68 #endif
69
70 #ifdef INET6
71 #include <netinet6/in6_var.h>
72 #include <netinet6/nd6.h>
73 #endif /* INET6 */
74
75 #ifdef INET
76 #include <machine/in_cksum.h>
77 #endif /* INET */
78
79 #define PFLOGMTU (32768 + MHLEN + MLEN)
80
81 #ifdef PFLOGDEBUG
82 #define DPRINTF(x) do { if (pflogdebug) printf x ; } while (0)
83 #else
84 #define DPRINTF(x)
85 #endif
86
87 static int pflogoutput(struct ifnet *, struct mbuf *,
88 const struct sockaddr *, struct route *);
89 static void pflogattach(int);
90 static int pflogioctl(struct ifnet *, u_long, caddr_t);
91 static void pflogstart(struct ifnet *);
92 static int pflog_clone_create(struct if_clone *, int, caddr_t);
93 static void pflog_clone_destroy(struct ifnet *);
94 static struct if_clone *pflog_cloner;
95
96 static const char pflogname[] = "pflog";
97
98 struct ifnet *pflogifs[PFLOGIFS_MAX]; /* for fast access */
99
100 static void
pflogattach(int npflog)101 pflogattach(int npflog)
102 {
103 int i;
104 for (i = 0; i < PFLOGIFS_MAX; i++)
105 pflogifs[i] = NULL;
106 pflog_cloner = if_clone_simple(pflogname, pflog_clone_create,
107 pflog_clone_destroy, 1);
108 }
109
110 static int
pflog_clone_create(struct if_clone * ifc,int unit,caddr_t param)111 pflog_clone_create(struct if_clone *ifc, int unit, caddr_t param)
112 {
113 struct ifnet *ifp;
114
115 if (unit >= PFLOGIFS_MAX)
116 return (EINVAL);
117
118 ifp = if_alloc(IFT_PFLOG);
119 if (ifp == NULL) {
120 return (ENOSPC);
121 }
122 if_initname(ifp, pflogname, unit);
123 ifp->if_mtu = PFLOGMTU;
124 ifp->if_ioctl = pflogioctl;
125 ifp->if_output = pflogoutput;
126 ifp->if_start = pflogstart;
127 ifp->if_snd.ifq_maxlen = ifqmaxlen;
128 ifp->if_hdrlen = PFLOG_HDRLEN;
129 if_attach(ifp);
130
131 bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN);
132
133 pflogifs[unit] = ifp;
134
135 return (0);
136 }
137
138 static void
pflog_clone_destroy(struct ifnet * ifp)139 pflog_clone_destroy(struct ifnet *ifp)
140 {
141 int i;
142
143 for (i = 0; i < PFLOGIFS_MAX; i++)
144 if (pflogifs[i] == ifp)
145 pflogifs[i] = NULL;
146
147 bpfdetach(ifp);
148 if_detach(ifp);
149 if_free(ifp);
150 }
151
152 /*
153 * Start output on the pflog interface.
154 */
155 static void
pflogstart(struct ifnet * ifp)156 pflogstart(struct ifnet *ifp)
157 {
158 struct mbuf *m;
159
160 for (;;) {
161 IF_LOCK(&ifp->if_snd);
162 _IF_DEQUEUE(&ifp->if_snd, m);
163 IF_UNLOCK(&ifp->if_snd);
164
165 if (m == NULL)
166 return;
167 else
168 m_freem(m);
169 }
170 }
171
172 static int
pflogoutput(struct ifnet * ifp,struct mbuf * m,const struct sockaddr * dst,struct route * rt)173 pflogoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
174 struct route *rt)
175 {
176 m_freem(m);
177 return (0);
178 }
179
180 /* ARGSUSED */
181 static int
pflogioctl(struct ifnet * ifp,u_long cmd,caddr_t data)182 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
183 {
184 switch (cmd) {
185 case SIOCSIFFLAGS:
186 if (ifp->if_flags & IFF_UP)
187 ifp->if_drv_flags |= IFF_DRV_RUNNING;
188 else
189 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
190 break;
191 default:
192 return (ENOTTY);
193 }
194
195 return (0);
196 }
197
198 static int
pflog_packet(struct pfi_kif * kif,struct mbuf * m,sa_family_t af,u_int8_t dir,u_int8_t reason,struct pf_rule * rm,struct pf_rule * am,struct pf_ruleset * ruleset,struct pf_pdesc * pd,int lookupsafe)199 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
200 u_int8_t reason, struct pf_rule *rm, struct pf_rule *am,
201 struct pf_ruleset *ruleset, struct pf_pdesc *pd, int lookupsafe)
202 {
203 struct ifnet *ifn;
204 struct pfloghdr hdr;
205
206 if (kif == NULL || m == NULL || rm == NULL || pd == NULL)
207 return ( 1);
208
209 if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf)
210 return (0);
211
212 bzero(&hdr, sizeof(hdr));
213 hdr.length = PFLOG_REAL_HDRLEN;
214 hdr.af = af;
215 hdr.action = rm->action;
216 hdr.reason = reason;
217 memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));
218
219 if (am == NULL) {
220 hdr.rulenr = htonl(rm->nr);
221 hdr.subrulenr = 1;
222 } else {
223 hdr.rulenr = htonl(am->nr);
224 hdr.subrulenr = htonl(rm->nr);
225 if (ruleset != NULL && ruleset->anchor != NULL)
226 strlcpy(hdr.ruleset, ruleset->anchor->name,
227 sizeof(hdr.ruleset));
228 }
229 /*
230 * XXXGL: we avoid pf_socket_lookup() when we are holding
231 * state lock, since this leads to unsafe LOR.
232 * These conditions are very very rare, however.
233 */
234 if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done && lookupsafe)
235 pd->lookup.done = pf_socket_lookup(dir, pd, m);
236 if (pd->lookup.done > 0)
237 hdr.uid = pd->lookup.uid;
238 else
239 hdr.uid = UID_MAX;
240 hdr.pid = NO_PID;
241 hdr.rule_uid = rm->cuid;
242 hdr.rule_pid = rm->cpid;
243 hdr.dir = dir;
244
245 #ifdef INET
246 if (af == AF_INET && dir == PF_OUT) {
247 struct ip *ip;
248
249 ip = mtod(m, struct ip *);
250 ip->ip_sum = 0;
251 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
252 }
253 #endif /* INET */
254
255 if_inc_counter(ifn, IFCOUNTER_OPACKETS, 1);
256 if_inc_counter(ifn, IFCOUNTER_OBYTES, m->m_pkthdr.len);
257 BPF_MTAP2(ifn, &hdr, PFLOG_HDRLEN, m);
258
259 return (0);
260 }
261
262 static int
pflog_modevent(module_t mod,int type,void * data)263 pflog_modevent(module_t mod, int type, void *data)
264 {
265 int error = 0;
266
267 switch (type) {
268 case MOD_LOAD:
269 pflogattach(1);
270 PF_RULES_WLOCK();
271 pflog_packet_ptr = pflog_packet;
272 PF_RULES_WUNLOCK();
273 break;
274 case MOD_UNLOAD:
275 PF_RULES_WLOCK();
276 pflog_packet_ptr = NULL;
277 PF_RULES_WUNLOCK();
278 if_clone_detach(pflog_cloner);
279 break;
280 default:
281 error = EINVAL;
282 break;
283 }
284
285 return error;
286 }
287
288 static moduledata_t pflog_mod = { pflogname, pflog_modevent, 0 };
289
290 #define PFLOG_MODVER 1
291
292 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
293 MODULE_VERSION(pflog, PFLOG_MODVER);
294 MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER);
295