1 /* $FreeBSD$ */ 2 /* $NetBSD: pfil.h,v 1.22 2003/06/23 12:57:08 martin Exp $ */ 3 4 /*- 5 * SPDX-License-Identifier: BSD-3-Clause 6 * 7 * Copyright (c) 1996 Matthew R. Green 8 * All rights reserved. 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 * 3. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef _NET_PFIL_H_ 35 #define _NET_PFIL_H_ 36 37 #include <sys/systm.h> 38 #include <sys/queue.h> 39 #include <sys/_lock.h> 40 #include <sys/_mutex.h> 41 #include <sys/lock.h> 42 #include <sys/rmlock.h> 43 #include <net/vnet.h> 44 45 struct mbuf; 46 struct ifnet; 47 struct inpcb; 48 49 typedef int (*pfil_func_t)(void *, struct mbuf **, struct ifnet *, int, 50 struct inpcb *); 51 52 /* 53 * The packet filter hooks are designed for anything to call them to 54 * possibly intercept the packet. Multiple filter hooks are chained 55 * together and after each other in the specified order. 56 */ 57 struct packet_filter_hook { 58 TAILQ_ENTRY(packet_filter_hook) pfil_chain; 59 pfil_func_t pfil_func; 60 void *pfil_arg; 61 }; 62 63 #define PFIL_IN 0x00000001 64 #define PFIL_OUT 0x00000002 65 #define PFIL_WAITOK 0x00000004 66 #define PFIL_ALL (PFIL_IN|PFIL_OUT) 67 68 typedef TAILQ_HEAD(pfil_chain, packet_filter_hook) pfil_chain_t; 69 70 #define PFIL_TYPE_AF 1 /* key is AF_* type */ 71 #define PFIL_TYPE_IFNET 2 /* key is ifnet pointer */ 72 73 #define PFIL_FLAG_PRIVATE_LOCK 0x01 /* Personal lock instead of global */ 74 75 /* 76 * A pfil head is created by each protocol or packet intercept point. 77 * For packet is then run through the hook chain for inspection. 78 */ 79 struct pfil_head { 80 pfil_chain_t ph_in; 81 pfil_chain_t ph_out; 82 int ph_type; 83 int ph_nhooks; 84 #if defined( __linux__ ) || defined( _WIN32 ) 85 rwlock_t ph_mtx; 86 #else 87 struct rmlock *ph_plock; /* Pointer to the used lock */ 88 struct rmlock ph_lock; /* Private lock storage */ 89 int flags; 90 #endif 91 union { 92 u_long phu_val; 93 void *phu_ptr; 94 } ph_un; 95 #define ph_af ph_un.phu_val 96 #define ph_ifnet ph_un.phu_ptr 97 LIST_ENTRY(pfil_head) ph_list; 98 }; 99 100 VNET_DECLARE(struct rmlock, pfil_lock); 101 #define V_pfil_lock VNET(pfil_lock) 102 103 /* Public functions for pfil hook management by packet filters. */ 104 struct pfil_head *pfil_head_get(int, u_long); 105 int pfil_add_hook(pfil_func_t, void *, int, struct pfil_head *); 106 int pfil_remove_hook(pfil_func_t, void *, int, struct pfil_head *); 107 #define PFIL_HOOKED(p) ((p)->ph_nhooks > 0) 108 109 /* Public functions to run the packet inspection by protocols. */ 110 int pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *, 111 int, struct inpcb *inp); 112 113 /* Public functions for pfil head management by protocols. */ 114 int pfil_head_register(struct pfil_head *); 115 int pfil_head_unregister(struct pfil_head *); 116 117 /* Public pfil locking functions for self managed locks by packet filters. */ 118 int pfil_try_rlock(struct pfil_head *, struct rm_priotracker *); 119 void pfil_rlock(struct pfil_head *, struct rm_priotracker *); 120 void pfil_runlock(struct pfil_head *, struct rm_priotracker *); 121 void pfil_wlock(struct pfil_head *); 122 void pfil_wunlock(struct pfil_head *); 123 int pfil_wowned(struct pfil_head *ph); 124 125 #endif /* _NET_PFIL_H_ */ 126