1 /*-
2 * SPDX-License-Identifier: ISC
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 * $OpenBSD: if_pflog.c,v 1.26 2007/10/18 21:58:18 mpf Exp $
37 */
38
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41
42 #include "opt_inet.h"
43 #include "opt_inet6.h"
44 #include "opt_bpf.h"
45 #include "opt_pf.h"
46
47 #include <sys/param.h>
48 #include <sys/kernel.h>
49 #include <sys/mbuf.h>
50 #include <sys/module.h>
51 #include <sys/proc.h>
52 #include <sys/socket.h>
53 #include <sys/sockio.h>
54
55 #include <net/bpf.h>
56 #include <net/if.h>
57 #include <net/if_var.h>
58 #include <net/if_clone.h>
59 #include <net/if_pflog.h>
60 #include <net/if_types.h>
61 #include <net/vnet.h>
62 #include <net/pfvar.h>
63
64 #if defined(INET) || defined(INET6)
65 #include <netinet/in.h>
66 #endif
67 #ifdef INET
68 #include <netinet/in_var.h>
69 #include <netinet/ip.h>
70 #endif
71
72 #ifdef INET6
73 #include <netinet6/in6_var.h>
74 #include <netinet6/nd6.h>
75 #endif /* INET6 */
76
77 #ifdef INET
78 #include <machine/in_cksum.h>
79 #endif /* INET */
80
81 #define PFLOGMTU (32768 + MHLEN + MLEN)
82
83 #ifdef PFLOGDEBUG
84 #define DPRINTF(x) do { if (pflogdebug) printf x ; } while (0)
85 #else
86 #define DPRINTF(x)
87 #endif
88
89 static int pflogoutput(struct ifnet *, struct mbuf *,
90 const struct sockaddr *, struct route *);
91 static void pflogattach(int);
92 static int pflogioctl(struct ifnet *, u_long, caddr_t);
93 static void pflogstart(struct ifnet *);
94 static int pflog_clone_create(struct if_clone *, char *, size_t,
95 struct ifc_data *, struct ifnet **);
96 static int pflog_clone_destroy(struct if_clone *, struct ifnet *, uint32_t);
97
98 static const char pflogname[] = "pflog";
99
100 VNET_DEFINE_STATIC(struct if_clone *, pflog_cloner);
101 #define V_pflog_cloner VNET(pflog_cloner)
102
103 VNET_DEFINE(struct ifnet *, pflogifs[PFLOGIFS_MAX]); /* for fast access */
104 #define V_pflogifs VNET(pflogifs)
105
106 static void
107 pflogattach(int npflog __unused)
108 {
109 int i;
110 for (i = 0; i < PFLOGIFS_MAX; i++)
111 V_pflogifs[i] = NULL;
112
113 struct if_clone_addreq req = {
114 .create_f = pflog_clone_create,
115 .destroy_f = pflog_clone_destroy,
116 .flags = IFC_F_AUTOUNIT,
117 };
118 V_pflog_cloner = ifc_attach_cloner(pflogname, &req);
119 struct ifc_data ifd = { .unit = 0 };
120 ifc_create_ifp(pflogname, &ifd, NULL);
121 }
122
123 static int
124 pflog_clone_create(struct if_clone *ifc, char *name, size_t maxlen,
125 struct ifc_data *ifd, struct ifnet **ifpp)
126 {
127 struct ifnet *ifp;
128
129 if (ifd->unit >= PFLOGIFS_MAX)
130 return (EINVAL);
131
132 ifp = if_alloc(IFT_PFLOG);
133 if (ifp == NULL) {
134 return (ENOSPC);
135 }
136 if_initname(ifp, pflogname, ifd->unit);
137 ifp->if_mtu = PFLOGMTU;
138 ifp->if_ioctl = pflogioctl;
139 ifp->if_output = pflogoutput;
140 ifp->if_start = pflogstart;
141 ifp->if_snd.ifq_maxlen = ifqmaxlen;
142 ifp->if_hdrlen = PFLOG_HDRLEN;
143 if_attach(ifp);
144
145 bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN);
146
147 V_pflogifs[ifd->unit] = ifp;
148 *ifpp = ifp;
149
150 return (0);
151 }
152
153 static int
154 pflog_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags)
155 {
156 int i;
157
158 if (ifp->if_dunit == 0 && (flags & IFC_F_FORCE) == 0)
159 return (EINVAL);
160
161 for (i = 0; i < PFLOGIFS_MAX; i++)
162 if (V_pflogifs[i] == ifp)
163 V_pflogifs[i] = NULL;
164
165 bpfdetach(ifp);
166 if_detach(ifp);
167 if_free(ifp);
168
169 return (0);
170 }
171
172 /*
173 * Start output on the pflog interface.
174 */
175 static void
176 pflogstart(struct ifnet *ifp)
177 {
178 struct mbuf *m;
179
180 for (;;) {
181 IF_LOCK(&ifp->if_snd);
182 _IF_DEQUEUE(&ifp->if_snd, m);
183 IF_UNLOCK(&ifp->if_snd);
184
185 if (m == NULL)
186 return;
187 else
188 m_freem(m);
189 }
190 }
191
192 static int
193 pflogoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
194 struct route *rt)
195 {
196 m_freem(m);
197 return (0);
198 }
199
200 /* ARGSUSED */
201 static int
202 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
203 {
204 switch (cmd) {
205 case SIOCSIFFLAGS:
206 if (ifp->if_flags & IFF_UP)
207 ifp->if_drv_flags |= IFF_DRV_RUNNING;
208 else
209 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
210 break;
211 default:
212 return (ENOTTY);
213 }
214
215 return (0);
216 }
217
218 static int
219 pflog_packet(struct pfi_kkif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
220 u_int8_t reason, struct pf_krule *rm, struct pf_krule *am,
221 struct pf_kruleset *ruleset, struct pf_pdesc *pd, int lookupsafe)
222 {
223 struct ifnet *ifn;
224 struct pfloghdr hdr;
225
226 if (kif == NULL || m == NULL || rm == NULL || pd == NULL)
227 return ( 1);
228
229 if ((ifn = V_pflogifs[rm->logif]) == NULL || !ifn->if_bpf)
230 return (0);
231
232 bzero(&hdr, sizeof(hdr));
233 hdr.length = PFLOG_REAL_HDRLEN;
234 hdr.af = af;
235 hdr.action = rm->action;
236 hdr.reason = reason;
237 memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));
238
239 if (am == NULL) {
240 hdr.rulenr = htonl(rm->nr);
241 hdr.subrulenr = -1;
242 } else {
243 hdr.rulenr = htonl(am->nr);
244 hdr.subrulenr = htonl(rm->nr);
245 if (ruleset != NULL && ruleset->anchor != NULL)
246 strlcpy(hdr.ruleset, ruleset->anchor->name,
247 sizeof(hdr.ruleset));
248 }
249 hdr.ridentifier = htonl(rm->ridentifier);
250 /*
251 * XXXGL: we avoid pf_socket_lookup() when we are holding
252 * state lock, since this leads to unsafe LOR.
253 * These conditions are very very rare, however.
254 */
255 if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done && lookupsafe)
256 pd->lookup.done = pf_socket_lookup(dir, pd, m);
257 if (pd->lookup.done > 0)
258 hdr.uid = pd->lookup.uid;
259 else
260 hdr.uid = UID_MAX;
261 hdr.pid = NO_PID;
262 hdr.rule_uid = rm->cuid;
263 hdr.rule_pid = rm->cpid;
264 hdr.dir = dir;
265
266 #ifdef INET
267 if (af == AF_INET && dir == PF_OUT) {
268 struct ip *ip;
269
270 ip = mtod(m, struct ip *);
271 ip->ip_sum = 0;
272 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
273 }
274 #endif /* INET */
275
276 if_inc_counter(ifn, IFCOUNTER_OPACKETS, 1);
277 if_inc_counter(ifn, IFCOUNTER_OBYTES, m->m_pkthdr.len);
278 BPF_MTAP2(ifn, &hdr, PFLOG_HDRLEN, m);
279
280 return (0);
281 }
282
283 static void
284 vnet_pflog_init(const void *unused __unused)
285 {
286
287 pflogattach(1);
288 }
289 VNET_SYSINIT(vnet_pflog_init, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY,
290 vnet_pflog_init, NULL);
291
292 static void
293 vnet_pflog_uninit(const void *unused __unused)
294 {
295
296 ifc_detach_cloner(V_pflog_cloner);
297 }
298 /*
299 * Detach after pf is gone; otherwise we might touch pflog memory
300 * from within pf after freeing pflog.
301 */
302 VNET_SYSUNINIT(vnet_pflog_uninit, SI_SUB_INIT_IF, SI_ORDER_SECOND,
303 vnet_pflog_uninit, NULL);
304
305 static int
306 pflog_modevent(module_t mod, int type, void *data)
307 {
308 int error = 0;
309
310 switch (type) {
311 case MOD_LOAD:
312 PF_RULES_WLOCK();
313 pflog_packet_ptr = pflog_packet;
314 PF_RULES_WUNLOCK();
315 break;
316 case MOD_UNLOAD:
317 PF_RULES_WLOCK();
318 pflog_packet_ptr = NULL;
319 PF_RULES_WUNLOCK();
320 break;
321 default:
322 error = EOPNOTSUPP;
323 break;
324 }
325
326 return error;
327 }
328
329 static moduledata_t pflog_mod = { pflogname, pflog_modevent, 0 };
330
331 #define PFLOG_MODVER 1
332
333 /* Do not run before pf is initialized as we depend on its locks. */
334 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY);
335 MODULE_VERSION(pflog, PFLOG_MODVER);
336 MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER);
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