npf_ext_log.c revision 1.10 
1/*	$NetBSD: npf_ext_log.c,v 1.10 2016/12/26 23:05:06 christos Exp $	*/
2
3/*-
4 * Copyright (c) 2010-2012 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This material is based upon work partially supported by The
8 * NetBSD Foundation under a contract with Mindaugas Rasiukevicius.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/*
33 * NPF logging extension.
34 */
35
36#ifdef _KERNEL
37#include <sys/cdefs.h>
38__KERNEL_RCSID(0, "$NetBSD: npf_ext_log.c,v 1.10 2016/12/26 23:05:06 christos Exp $");
39
40#include <sys/types.h>
41#include <sys/module.h>
42
43#include <sys/conf.h>
44#include <sys/kmem.h>
45#include <sys/mbuf.h>
46#include <sys/mutex.h>
47#include <sys/queue.h>
48
49#include <net/if.h>
50#include <net/if_types.h>
51#include <net/bpf.h>
52#endif
53
54#include "npf_impl.h"
55
56NPF_EXT_MODULE(npf_ext_log, "");
57
58#define	NPFEXT_LOG_VER		1
59
60static void *		npf_ext_log_id;
61
62typedef struct {
63	unsigned int	if_idx;
64} npf_ext_log_t;
65
66static int
67npf_log_ctor(npf_rproc_t *rp, prop_dictionary_t params)
68{
69	npf_ext_log_t *meta;
70
71	meta = kmem_zalloc(sizeof(npf_ext_log_t), KM_SLEEP);
72	prop_dictionary_get_uint32(params, "log-interface", &meta->if_idx);
73	npf_rproc_assign(rp, meta);
74	return 0;
75}
76
77static void
78npf_log_dtor(npf_rproc_t *rp, void *meta)
79{
80	kmem_free(meta, sizeof(npf_ext_log_t));
81}
82
83static bool
84npf_log(npf_cache_t *npc, void *meta, int *decision)
85{
86	struct mbuf *m = nbuf_head_mbuf(npc->npc_nbuf);
87	const npf_ext_log_t *log = meta;
88	struct psref psref;
89	ifnet_t *ifp;
90	int family;
91
92	/* Set the address family. */
93	if (npf_iscached(npc, NPC_IP4)) {
94		family = AF_INET;
95	} else if (npf_iscached(npc, NPC_IP6)) {
96		family = AF_INET6;
97	} else {
98		family = AF_UNSPEC;
99	}
100
101	KERNEL_LOCK(1, NULL);
102
103	/* Find a pseudo-interface to log. */
104	ifp = if_get_byindex(log->if_idx, &psref);
105	if (ifp == NULL) {
106		/* No interface. */
107		KERNEL_UNLOCK_ONE(NULL);
108		return true;
109	}
110
111	/* Pass through BPF. */
112	ifp->if_opackets++;
113	ifp->if_obytes += m->m_pkthdr.len;
114	bpf_mtap_af(ifp, family, m);
115	if_put(ifp, &psref);
116
117	KERNEL_UNLOCK_ONE(NULL);
118
119	return true;
120}
121
122/*
123 * Module interface.
124 */
125static int
126npf_ext_log_modcmd(modcmd_t cmd, void *arg)
127{
128	static const npf_ext_ops_t npf_log_ops = {
129		.version	= NPFEXT_LOG_VER,
130		.ctx		= NULL,
131		.ctor		= npf_log_ctor,
132		.dtor		= npf_log_dtor,
133		.proc		= npf_log
134	};
135	npf_t *npf = npf_getkernctx();
136	int error;
137
138	switch (cmd) {
139	case MODULE_CMD_INIT:
140		/*
141		 * Initialise the NPF logging extension.
142		 */
143		npf_ext_log_id = npf_ext_register(npf, "log", &npf_log_ops);
144		if (!npf_ext_log_id) {
145			return EEXIST;
146		}
147		break;
148
149	case MODULE_CMD_FINI:
150		error = npf_ext_unregister(npf, npf_ext_log_id);
151		if (error) {
152			return error;
153		}
154		break;
155
156	case MODULE_CMD_AUTOUNLOAD:
157		/* Allow auto-unload only if NPF permits it. */
158		return npf_autounload_p() ? 0 : EBUSY;
159
160	default:
161		return ENOTTY;
162	}
163	return 0;
164}
165