1 /* $NetBSD: pfil.h,v 1.29 2008/05/29 14:51:27 mrg Exp $ */ 2 3 /* 4 * Copyright (c) 1996 Matthew R. Green 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #ifndef _NET_PFIL_H_ 30 #define _NET_PFIL_H_ 31 32 #ifdef _KERNEL_OPT 33 #include "opt_pfil_hooks.h" 34 #endif 35 36 #include <sys/queue.h> 37 #include <net/dlt.h> 38 #include <sys/null.h> 39 40 struct mbuf; 41 struct ifnet; 42 43 /* 44 * The packet filter hooks are designed for anything to call them to 45 * possibly intercept the packet. 46 */ 47 struct packet_filter_hook { 48 TAILQ_ENTRY(packet_filter_hook) pfil_link; 49 int (*pfil_func)(void *, struct mbuf **, struct ifnet *, int); 50 void *pfil_arg; 51 int pfil_flags; 52 }; 53 54 #define PFIL_IN 0x00000001 55 #define PFIL_OUT 0x00000002 56 #define PFIL_ALL (PFIL_IN|PFIL_OUT) 57 #define PFIL_WAITOK 0x00000004 58 #define PFIL_IFADDR 0x00000008 59 #define PFIL_IFNET 0x00000010 60 61 /* events notified by PFIL_IFNET */ 62 #define PFIL_IFNET_ATTACH 0 63 #define PFIL_IFNET_DETACH 1 64 65 typedef TAILQ_HEAD(pfil_list, packet_filter_hook) pfil_list_t; 66 67 #define PFIL_TYPE_AF 1 /* key is AF_* type */ 68 #define PFIL_TYPE_IFNET 2 /* key is ifnet pointer */ 69 70 struct pfil_head { 71 pfil_list_t ph_in; 72 pfil_list_t ph_out; 73 pfil_list_t ph_ifaddr; 74 pfil_list_t ph_ifnetevent; /* XXX naming collision */ 75 int ph_type; 76 union { 77 u_long phu_val; 78 void *phu_ptr; 79 } ph_un; 80 #define ph_af ph_un.phu_val 81 #define ph_ifnet ph_un.phu_ptr 82 LIST_ENTRY(pfil_head) ph_list; 83 }; 84 typedef struct pfil_head pfil_head_t; 85 86 #ifdef _KERNEL 87 88 int pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *, 89 int); 90 91 int pfil_add_hook(int (*func)(void *, struct mbuf **, 92 struct ifnet *, int), void *, int, struct pfil_head *); 93 int pfil_remove_hook(int (*func)(void *, struct mbuf **, 94 struct ifnet *, int), void *, int, struct pfil_head *); 95 96 int pfil_head_register(struct pfil_head *); 97 int pfil_head_unregister(struct pfil_head *); 98 99 struct pfil_head *pfil_head_get(int, u_long); 100 101 static __inline struct packet_filter_hook * 102 pfil_hook_get(int dir, struct pfil_head *ph) 103 { 104 105 if (dir == PFIL_IN) 106 return (TAILQ_FIRST(&ph->ph_in)); 107 else if (dir == PFIL_OUT) 108 return (TAILQ_FIRST(&ph->ph_out)); 109 else if (dir == PFIL_IFADDR) 110 return (TAILQ_FIRST(&ph->ph_ifaddr)); 111 else if (dir == PFIL_IFNET) 112 return (TAILQ_FIRST(&ph->ph_ifnetevent)); 113 else 114 return (NULL); 115 } 116 117 #endif /* _KERNEL */ 118 119 /* XXX */ 120 #if defined(_KERNEL_OPT) 121 #include "ipfilter.h" 122 #endif 123 124 #if NIPFILTER > 0 125 #ifdef PFIL_HOOKS 126 #undef PFIL_HOOKS 127 #endif 128 #define PFIL_HOOKS 129 #endif /* NIPFILTER */ 130 131 #ifdef _KERNEL 132 /* in sys/net/if.c */ 133 extern struct pfil_head if_pfil; /* packet filtering hook for interfaces */ 134 #endif /* _KERNEL */ 135 136 #endif /* !_NET_PFIL_H_ */ 137