1 /* $FreeBSD$ */ 2 /* $NetBSD: pfil.h,v 1.22 2003/06/23 12:57:08 martin Exp $ */ 3 4 /*- 5 * Copyright (c) 1996 Matthew R. Green 6 * All rights reserved. 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 * 3. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 24 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 26 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 27 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #ifndef _NET_PFIL_H_ 33 #define _NET_PFIL_H_ 34 35 #include <sys/systm.h> 36 #include <sys/queue.h> 37 #include <sys/_lock.h> 38 #include <sys/_mutex.h> 39 #include <sys/lock.h> 40 #include <sys/rmlock.h> 41 #include <net/vnet.h> 42 43 struct mbuf; 44 struct ifnet; 45 struct inpcb; 46 47 typedef int (*pfil_func_t)(void *, struct mbuf **, struct ifnet *, int, 48 struct inpcb *); 49 50 /* 51 * The packet filter hooks are designed for anything to call them to 52 * possibly intercept the packet. Multiple filter hooks are chained 53 * together and after each other in the specified order. 54 */ 55 struct packet_filter_hook { 56 TAILQ_ENTRY(packet_filter_hook) pfil_chain; 57 pfil_func_t pfil_func; 58 void *pfil_arg; 59 }; 60 61 #define PFIL_IN 0x00000001 62 #define PFIL_OUT 0x00000002 63 #define PFIL_WAITOK 0x00000004 64 #define PFIL_ALL (PFIL_IN|PFIL_OUT) 65 66 typedef TAILQ_HEAD(pfil_chain, packet_filter_hook) pfil_chain_t; 67 68 #define PFIL_TYPE_AF 1 /* key is AF_* type */ 69 #define PFIL_TYPE_IFNET 2 /* key is ifnet pointer */ 70 71 #define PFIL_FLAG_PRIVATE_LOCK 0x01 /* Personal lock instead of global */ 72 73 /* 74 * A pfil head is created by each protocol or packet intercept point. 75 * For packet is then run through the hook chain for inspection. 76 */ 77 struct pfil_head { 78 pfil_chain_t ph_in; 79 pfil_chain_t ph_out; 80 int ph_type; 81 int ph_nhooks; 82 #if defined( __linux__ ) || defined( _WIN32 ) 83 rwlock_t ph_mtx; 84 #else 85 struct rmlock *ph_plock; /* Pointer to the used lock */ 86 struct rmlock ph_lock; /* Private lock storage */ 87 int flags; 88 #endif 89 union { 90 u_long phu_val; 91 void *phu_ptr; 92 } ph_un; 93 #define ph_af ph_un.phu_val 94 #define ph_ifnet ph_un.phu_ptr 95 LIST_ENTRY(pfil_head) ph_list; 96 }; 97 98 VNET_DECLARE(struct rmlock, pfil_lock); 99 #define V_pfil_lock VNET(pfil_lock) 100 101 /* Public functions for pfil hook management by packet filters. */ 102 struct pfil_head *pfil_head_get(int, u_long); 103 int pfil_add_hook(pfil_func_t, void *, int, struct pfil_head *); 104 int pfil_remove_hook(pfil_func_t, void *, int, struct pfil_head *); 105 #define PFIL_HOOKED(p) ((p)->ph_nhooks > 0) 106 107 /* Public functions to run the packet inspection by protocols. */ 108 int pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *, 109 int, struct inpcb *inp); 110 111 /* Public functions for pfil head management by protocols. */ 112 int pfil_head_register(struct pfil_head *); 113 int pfil_head_unregister(struct pfil_head *); 114 115 /* Public pfil locking functions for self managed locks by packet filters. */ 116 int pfil_try_rlock(struct pfil_head *, struct rm_priotracker *); 117 void pfil_rlock(struct pfil_head *, struct rm_priotracker *); 118 void pfil_runlock(struct pfil_head *, struct rm_priotracker *); 119 void pfil_wlock(struct pfil_head *); 120 void pfil_wunlock(struct pfil_head *); 121 int pfil_wowned(struct pfil_head *ph); 122 123 #endif /* _NET_PFIL_H_ */ 124