1 /* $NetBSD: npf_if.c,v 1.6 2016/05/12 02:24:17 ozaki-r Exp $ */
2
3 /*-
4 * Copyright (c) 2013 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by 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 network interface handling module.
34 *
35 * NPF uses its own interface IDs (npf-if-id). When NPF configuration is
36 * (re)loaded, each required interface name is registered and a matching
37 * network interface gets an ID assigned. If an interface is not present,
38 * it gets an ID on attach.
39 *
40 * IDs start from 1. Zero is reserved to indicate "no interface" case or
41 * an interface of no interest (i.e. not registered).
42 *
43 * The IDs are mapped synchronously based on interface events which are
44 * monitored using pfil(9) hooks.
45 */
46
47 #include <sys/cdefs.h>
48 __KERNEL_RCSID(0, "$NetBSD: npf_if.c,v 1.6 2016/05/12 02:24:17 ozaki-r Exp $");
49
50 #ifdef _KERNEL_OPT
51 #include "pf.h"
52 #if NPF > 0
53 #error "NPF and PF are mutually exclusive; please select one"
54 #endif
55 #endif
56
57 #include <sys/param.h>
58 #include <sys/types.h>
59 #include <sys/kmem.h>
60
61 #include <net/if.h>
62
63 #include "npf_impl.h"
64
65 typedef struct {
66 char n_ifname[IFNAMSIZ];
67 } npf_ifmap_t;
68
69 static npf_ifmap_t npf_ifmap[NPF_MAX_IFMAP] __read_mostly;
70 static u_int npf_ifmap_cnt __read_mostly;
71
72 static u_int
npf_ifmap_new(void)73 npf_ifmap_new(void)
74 {
75 KASSERT(npf_config_locked_p());
76
77 for (u_int i = 0; i < npf_ifmap_cnt; i++)
78 if (npf_ifmap[i].n_ifname[0] == '\0')
79 return i + 1;
80
81 if (npf_ifmap_cnt == NPF_MAX_IFMAP) {
82 printf("npf_ifmap_new: out of slots; bump NPF_MAX_IFMAP\n");
83 return 0;
84 }
85 return ++npf_ifmap_cnt;
86 }
87
88 static u_int
npf_ifmap_lookup(const char * ifname)89 npf_ifmap_lookup(const char *ifname)
90 {
91 KASSERT(npf_config_locked_p());
92
93 for (u_int i = 0; i < npf_ifmap_cnt; i++) {
94 npf_ifmap_t *nim = &npf_ifmap[i];
95
96 if (nim->n_ifname[0] && strcmp(nim->n_ifname, ifname) == 0)
97 return i + 1;
98 }
99 return 0;
100 }
101
102 u_int
npf_ifmap_register(const char * ifname)103 npf_ifmap_register(const char *ifname)
104 {
105 npf_ifmap_t *nim;
106 ifnet_t *ifp;
107 u_int i;
108
109 npf_config_enter();
110 if ((i = npf_ifmap_lookup(ifname)) != 0) {
111 goto out;
112 }
113 if ((i = npf_ifmap_new()) == 0) {
114 goto out;
115 }
116 nim = &npf_ifmap[i - 1];
117 strlcpy(nim->n_ifname, ifname, IFNAMSIZ);
118
119 KERNEL_LOCK(1, NULL);
120 if ((ifp = ifunit(ifname)) != NULL) {
121 ifp->if_pf_kif = (void *)(uintptr_t)i;
122 }
123 KERNEL_UNLOCK_ONE(NULL);
124 out:
125 npf_config_exit();
126 return i;
127 }
128
129 void
npf_ifmap_flush(void)130 npf_ifmap_flush(void)
131 {
132 ifnet_t *ifp;
133
134 KASSERT(npf_config_locked_p());
135
136 for (u_int i = 0; i < npf_ifmap_cnt; i++) {
137 npf_ifmap[i].n_ifname[0] = '\0';
138 }
139 npf_ifmap_cnt = 0;
140
141 KERNEL_LOCK(1, NULL);
142 IFNET_LOCK();
143 IFNET_WRITER_FOREACH(ifp) {
144 ifp->if_pf_kif = (void *)(uintptr_t)0;
145 }
146 IFNET_UNLOCK();
147 KERNEL_UNLOCK_ONE(NULL);
148 }
149
150 u_int
npf_ifmap_getid(const ifnet_t * ifp)151 npf_ifmap_getid(const ifnet_t *ifp)
152 {
153 const u_int i = (uintptr_t)ifp->if_pf_kif;
154 KASSERT(i <= npf_ifmap_cnt);
155 return i;
156 }
157
158 const char *
npf_ifmap_getname(const u_int id)159 npf_ifmap_getname(const u_int id)
160 {
161 const char *ifname;
162
163 KASSERT(npf_config_locked_p());
164 KASSERT(id > 0 && id <= npf_ifmap_cnt);
165
166 ifname = npf_ifmap[id - 1].n_ifname;
167 KASSERT(ifname[0] != '\0');
168 return ifname;
169 }
170
171 void
npf_ifmap_attach(ifnet_t * ifp)172 npf_ifmap_attach(ifnet_t *ifp)
173 {
174 npf_config_enter();
175 ifp->if_pf_kif = (void *)(uintptr_t)npf_ifmap_lookup(ifp->if_xname);
176 npf_config_exit();
177 }
178
179 void
npf_ifmap_detach(ifnet_t * ifp)180 npf_ifmap_detach(ifnet_t *ifp)
181 {
182 /* Diagnostic. */
183 npf_config_enter();
184 ifp->if_pf_kif = (void *)(uintptr_t)0;
185 npf_config_exit();
186 }
187