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: stable/10/sys/netpfil/pf/if_pflog.c 310094 2016-12-14 21:30:35Z kp $");
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_clone.h>
56#include <net/if_pflog.h>
57#include <net/if_types.h>
58#include <net/pfvar.h>
59
60#if defined(INET) || defined(INET6)
61#include <netinet/in.h>
62#endif
63#ifdef	INET
64#include <netinet/in_var.h>
65#include <netinet/ip.h>
66#endif
67
68#ifdef INET6
69#include <netinet6/in6_var.h>
70#include <netinet6/nd6.h>
71#endif /* INET6 */
72
73#ifdef INET
74#include <machine/in_cksum.h>
75#endif /* INET */
76
77#define PFLOGMTU	(32768 + MHLEN + MLEN)
78
79#ifdef PFLOGDEBUG
80#define DPRINTF(x)    do { if (pflogdebug) printf x ; } while (0)
81#else
82#define DPRINTF(x)
83#endif
84
85static int	pflogoutput(struct ifnet *, struct mbuf *,
86		    const struct sockaddr *, struct route *);
87static void	pflogattach(int);
88static int	pflogioctl(struct ifnet *, u_long, caddr_t);
89static void	pflogstart(struct ifnet *);
90static int	pflog_clone_create(struct if_clone *, int, caddr_t);
91static void	pflog_clone_destroy(struct ifnet *);
92static struct if_clone *pflog_cloner;
93
94static const char pflogname[] = "pflog";
95
96struct ifnet	*pflogifs[PFLOGIFS_MAX];	/* for fast access */
97
98static void
99pflogattach(int npflog)
100{
101	int	i;
102	for (i = 0; i < PFLOGIFS_MAX; i++)
103		pflogifs[i] = NULL;
104	pflog_cloner = if_clone_simple(pflogname, pflog_clone_create,
105	    pflog_clone_destroy, 1);
106}
107
108static int
109pflog_clone_create(struct if_clone *ifc, int unit, caddr_t param)
110{
111	struct ifnet *ifp;
112
113	if (unit >= PFLOGIFS_MAX)
114		return (EINVAL);
115
116	ifp = if_alloc(IFT_PFLOG);
117	if (ifp == NULL) {
118		return (ENOSPC);
119	}
120	if_initname(ifp, pflogname, unit);
121	ifp->if_mtu = PFLOGMTU;
122	ifp->if_ioctl = pflogioctl;
123	ifp->if_output = pflogoutput;
124	ifp->if_start = pflogstart;
125	ifp->if_snd.ifq_maxlen = ifqmaxlen;
126	ifp->if_hdrlen = PFLOG_HDRLEN;
127	if_attach(ifp);
128
129	bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN);
130
131	pflogifs[unit] = ifp;
132
133	return (0);
134}
135
136static void
137pflog_clone_destroy(struct ifnet *ifp)
138{
139	int i;
140
141	for (i = 0; i < PFLOGIFS_MAX; i++)
142		if (pflogifs[i] == ifp)
143			pflogifs[i] = NULL;
144
145	bpfdetach(ifp);
146	if_detach(ifp);
147	if_free(ifp);
148}
149
150/*
151 * Start output on the pflog interface.
152 */
153static void
154pflogstart(struct ifnet *ifp)
155{
156	struct mbuf *m;
157
158	for (;;) {
159		IF_LOCK(&ifp->if_snd);
160		_IF_DROP(&ifp->if_snd);
161		_IF_DEQUEUE(&ifp->if_snd, m);
162		IF_UNLOCK(&ifp->if_snd);
163
164		if (m == NULL)
165			return;
166		else
167			m_freem(m);
168	}
169}
170
171static int
172pflogoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
173	struct route *rt)
174{
175	m_freem(m);
176	return (0);
177}
178
179/* ARGSUSED */
180static int
181pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
182{
183	switch (cmd) {
184	case SIOCSIFFLAGS:
185		if (ifp->if_flags & IFF_UP)
186			ifp->if_drv_flags |= IFF_DRV_RUNNING;
187		else
188			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
189		break;
190	default:
191		return (ENOTTY);
192	}
193
194	return (0);
195}
196
197static int
198pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
199    u_int8_t reason, struct pf_rule *rm, struct pf_rule *am,
200    struct pf_ruleset *ruleset, struct pf_pdesc *pd, int lookupsafe)
201{
202	struct ifnet *ifn;
203	struct pfloghdr hdr;
204
205	if (kif == NULL || m == NULL || rm == NULL || pd == NULL)
206		return ( 1);
207
208	if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf)
209		return (0);
210
211	bzero(&hdr, sizeof(hdr));
212	hdr.length = PFLOG_REAL_HDRLEN;
213	hdr.af = af;
214	hdr.action = rm->action;
215	hdr.reason = reason;
216	memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));
217
218	if (am == NULL) {
219		hdr.rulenr = htonl(rm->nr);
220		hdr.subrulenr = -1;
221	} else {
222		hdr.rulenr = htonl(am->nr);
223		hdr.subrulenr = htonl(rm->nr);
224		if (ruleset != NULL && ruleset->anchor != NULL)
225			strlcpy(hdr.ruleset, ruleset->anchor->name,
226			    sizeof(hdr.ruleset));
227	}
228	/*
229	 * XXXGL: we avoid pf_socket_lookup() when we are holding
230	 * state lock, since this leads to unsafe LOR.
231	 * These conditions are very very rare, however.
232	 */
233	if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done && lookupsafe)
234		pd->lookup.done = pf_socket_lookup(dir, pd, m);
235	if (pd->lookup.done > 0)
236		hdr.uid = pd->lookup.uid;
237	else
238		hdr.uid = UID_MAX;
239	hdr.pid = NO_PID;
240	hdr.rule_uid = rm->cuid;
241	hdr.rule_pid = rm->cpid;
242	hdr.dir = dir;
243
244#ifdef INET
245	if (af == AF_INET && dir == PF_OUT) {
246		struct ip *ip;
247
248		ip = mtod(m, struct ip *);
249		ip->ip_sum = 0;
250		ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
251	}
252#endif /* INET */
253
254	ifn->if_opackets++;
255	ifn->if_obytes += m->m_pkthdr.len;
256	BPF_MTAP2(ifn, &hdr, PFLOG_HDRLEN, m);
257
258	return (0);
259}
260
261static int
262pflog_modevent(module_t mod, int type, void *data)
263{
264	int error = 0;
265
266	switch (type) {
267	case MOD_LOAD:
268		pflogattach(1);
269		PF_RULES_WLOCK();
270		pflog_packet_ptr = pflog_packet;
271		PF_RULES_WUNLOCK();
272		break;
273	case MOD_UNLOAD:
274		PF_RULES_WLOCK();
275		pflog_packet_ptr = NULL;
276		PF_RULES_WUNLOCK();
277		if_clone_detach(pflog_cloner);
278		break;
279	default:
280		error = EINVAL;
281		break;
282	}
283
284	return error;
285}
286
287static moduledata_t pflog_mod = { pflogname, pflog_modevent, 0 };
288
289#define PFLOG_MODVER 1
290
291DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
292MODULE_VERSION(pflog, PFLOG_MODVER);
293MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER);
294