1 /* $NetBSD: npf_if.c,v 1.5 2015/07/12 23:51:53 rmind 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 1.5 2015/07/12 23:51:53 rmind 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 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 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 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 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_FOREACH(ifp) { 143 ifp->if_pf_kif = (void *)(uintptr_t)0; 144 } 145 KERNEL_UNLOCK_ONE(NULL); 146 } 147 148 u_int 149 npf_ifmap_getid(const ifnet_t *ifp) 150 { 151 const u_int i = (uintptr_t)ifp->if_pf_kif; 152 KASSERT(i <= npf_ifmap_cnt); 153 return i; 154 } 155 156 const char * 157 npf_ifmap_getname(const u_int id) 158 { 159 const char *ifname; 160 161 KASSERT(npf_config_locked_p()); 162 KASSERT(id > 0 && id <= npf_ifmap_cnt); 163 164 ifname = npf_ifmap[id - 1].n_ifname; 165 KASSERT(ifname[0] != '\0'); 166 return ifname; 167 } 168 169 void 170 npf_ifmap_attach(ifnet_t *ifp) 171 { 172 npf_config_enter(); 173 ifp->if_pf_kif = (void *)(uintptr_t)npf_ifmap_lookup(ifp->if_xname); 174 npf_config_exit(); 175 } 176 177 void 178 npf_ifmap_detach(ifnet_t *ifp) 179 { 180 /* Diagnostic. */ 181 npf_config_enter(); 182 ifp->if_pf_kif = (void *)(uintptr_t)0; 183 npf_config_exit(); 184 } 185