1 /*-
2 * Copyright (c) 2010-2012 The NetBSD Foundation, Inc.
3 * All rights reserved.
4 *
5 * This material is based upon work partially supported by The
6 * NetBSD Foundation under a contract with Mindaugas Rasiukevicius.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 /*
31 * NPF logging extension.
32 */
33
34 #ifdef _KERNEL
35 #include <sys/cdefs.h>
36 __KERNEL_RCSID(0, "$NetBSD: npf_ext_log.c,v 1.17 2020/05/30 14:16:56 rmind Exp $");
37
38 #include <sys/types.h>
39 #include <sys/module.h>
40
41 #include <sys/conf.h>
42 #include <sys/kmem.h>
43 #include <sys/mbuf.h>
44 #include <sys/mutex.h>
45 #include <sys/queue.h>
46
47 #include <net/if.h>
48 #include <net/if_types.h>
49 #include <net/bpf.h>
50 #endif
51
52 #include "npf_impl.h"
53 #include "if_npflog.h"
54
55 NPF_EXT_MODULE(npf_ext_log, "");
56
57 #define NPFEXT_LOG_VER 1
58
59 static void * npf_ext_log_id;
60
61 typedef struct {
62 unsigned int if_idx;
63 } npf_ext_log_t;
64
65 static int
npf_log_ctor(npf_rproc_t * rp,const nvlist_t * params)66 npf_log_ctor(npf_rproc_t *rp, const nvlist_t *params)
67 {
68 npf_ext_log_t *meta;
69
70 meta = kmem_zalloc(sizeof(npf_ext_log_t), KM_SLEEP);
71 meta->if_idx = dnvlist_get_number(params, "log-interface", 0);
72 npf_rproc_assign(rp, meta);
73 return 0;
74 }
75
76 static void
npf_log_dtor(npf_rproc_t * rp,void * meta)77 npf_log_dtor(npf_rproc_t *rp, void *meta)
78 {
79 kmem_free(meta, sizeof(npf_ext_log_t));
80 }
81
82 static bool
npf_log(npf_cache_t * npc,void * meta,const npf_match_info_t * mi,int * decision)83 npf_log(npf_cache_t *npc, void *meta, const npf_match_info_t *mi, int *decision)
84 {
85 struct mbuf *m = nbuf_head_mbuf(npc->npc_nbuf);
86 const npf_ext_log_t *log = meta;
87 struct psref psref;
88 ifnet_t *ifp;
89 struct npfloghdr hdr;
90
91 memset(&hdr, 0, sizeof(hdr));
92 /* Set the address family. */
93 if (npf_iscached(npc, NPC_IP4)) {
94 hdr.af = AF_INET;
95 } else if (npf_iscached(npc, NPC_IP6)) {
96 hdr.af = AF_INET6;
97 } else {
98 hdr.af = AF_UNSPEC;
99 }
100
101 hdr.length = NPFLOG_REAL_HDRLEN;
102 hdr.action = *decision == NPF_DECISION_PASS ?
103 0 /* pass */ : 1 /* block */;
104 hdr.reason = 0; /* match */
105
106 struct nbuf *nb = npc->npc_nbuf;
107 npf_ifmap_copyname(npc->npc_ctx, nb ? nb->nb_ifid : 0,
108 hdr.ifname, sizeof(hdr.ifname));
109
110 hdr.rulenr = htonl((uint32_t)mi->mi_rid);
111 hdr.subrulenr = htonl((uint32_t)(mi->mi_rid >> 32));
112 strlcpy(hdr.ruleset, "rules", sizeof(hdr.ruleset));
113
114 hdr.uid = UID_MAX;
115 hdr.pid = (pid_t)-1;
116 hdr.rule_uid = UID_MAX;
117 hdr.rule_pid = (pid_t)-1;
118
119 switch (mi->mi_di) {
120 default:
121 case PFIL_IN|PFIL_OUT:
122 hdr.dir = 0;
123 break;
124 case PFIL_IN:
125 hdr.dir = 1;
126 break;
127 case PFIL_OUT:
128 hdr.dir = 2;
129 break;
130 }
131
132 KERNEL_LOCK(1, NULL);
133
134 /* Find a pseudo-interface to log. */
135 ifp = if_get_byindex(log->if_idx, &psref);
136 if (ifp == NULL) {
137 /* No interface. */
138 KERNEL_UNLOCK_ONE(NULL);
139 return true;
140 }
141
142 if_statadd2(ifp, if_opackets, 1, if_obytes, m->m_pkthdr.len);
143 if (ifp->if_bpf) {
144 /* Pass through BPF. */
145 bpf_mtap2(ifp->if_bpf, &hdr, NPFLOG_HDRLEN, m, BPF_D_OUT);
146 }
147 if_put(ifp, &psref);
148
149 KERNEL_UNLOCK_ONE(NULL);
150
151 return true;
152 }
153
154 __dso_public int
npf_ext_log_init(npf_t * npf)155 npf_ext_log_init(npf_t *npf)
156 {
157 static const npf_ext_ops_t npf_log_ops = {
158 .version = NPFEXT_LOG_VER,
159 .ctx = NULL,
160 .ctor = npf_log_ctor,
161 .dtor = npf_log_dtor,
162 .proc = npf_log
163 };
164 npf_ext_log_id = npf_ext_register(npf, "log", &npf_log_ops);
165 return npf_ext_log_id ? 0 : EEXIST;
166 }
167
168 __dso_public int
npf_ext_log_fini(npf_t * npf)169 npf_ext_log_fini(npf_t *npf)
170 {
171 return npf_ext_unregister(npf, npf_ext_log_id);
172 }
173
174 #ifdef _KERNEL
175 static int
npf_ext_log_modcmd(modcmd_t cmd,void * arg)176 npf_ext_log_modcmd(modcmd_t cmd, void *arg)
177 {
178 npf_t *npf = npf_getkernctx();
179
180 switch (cmd) {
181 case MODULE_CMD_INIT:
182 return npf_ext_log_init(npf);
183 case MODULE_CMD_FINI:
184 return npf_ext_log_fini(npf);
185 break;
186 case MODULE_CMD_AUTOUNLOAD:
187 return npf_autounload_p() ? 0 : EBUSY;
188 default:
189 return ENOTTY;
190 }
191 return 0;
192 }
193 #endif
194