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 42 struct mbuf; 43 struct ifnet; 44 struct inpcb; 45 46 /* 47 * The packet filter hooks are designed for anything to call them to 48 * possibly intercept the packet. 49 */ 50 struct packet_filter_hook { 51 TAILQ_ENTRY(packet_filter_hook) pfil_link; 52 int (*pfil_func)(void *, struct mbuf **, struct ifnet *, int, 53 struct inpcb *); 54 void *pfil_arg; 55 int pfil_flags; 56 }; 57 58 #define PFIL_IN 0x00000001 59 #define PFIL_OUT 0x00000002 60 #define PFIL_WAITOK 0x00000004 61 #define PFIL_ALL (PFIL_IN|PFIL_OUT) 62 63 typedef TAILQ_HEAD(pfil_list, packet_filter_hook) pfil_list_t; 64 65 #define PFIL_TYPE_AF 1 /* key is AF_* type */ 66 #define PFIL_TYPE_IFNET 2 /* key is ifnet pointer */ 67 68 struct pfil_head { 69 pfil_list_t ph_in; 70 pfil_list_t ph_out; 71 int ph_type; 72 int ph_nhooks; 73 struct rmlock ph_lock; 74 union { 75 u_long phu_val; 76 void *phu_ptr; 77 } ph_un; 78 #define ph_af ph_un.phu_val 79 #define ph_ifnet ph_un.phu_ptr 80 LIST_ENTRY(pfil_head) ph_list; 81 }; 82 83 int pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *, 84 int, struct inpcb *inp); 85 86 int pfil_add_hook(int (*func)(void *, struct mbuf **, 87 struct ifnet *, int, struct inpcb *), void *, int, struct pfil_head *); 88 int pfil_remove_hook(int (*func)(void *, struct mbuf **, 89 struct ifnet *, int, struct inpcb *), void *, int, struct pfil_head *); 90 91 int pfil_head_register(struct pfil_head *); 92 int pfil_head_unregister(struct pfil_head *); 93 94 struct pfil_head *pfil_head_get(int, u_long); 95 96 #define PFIL_HOOKED(p) ((p)->ph_nhooks > 0) 97 #define PFIL_LOCK_INIT(p) \ 98 rm_init(&(p)->ph_lock, "PFil hook read/write mutex", LO_RECURSABLE) 99 #define PFIL_LOCK_DESTROY(p) rm_destroy(&(p)->ph_lock) 100 #define PFIL_RLOCK(p, t) rm_rlock(&(p)->ph_lock, (t)) 101 #define PFIL_WLOCK(p) rm_wlock(&(p)->ph_lock) 102 #define PFIL_RUNLOCK(p, t) rm_runlock(&(p)->ph_lock, (t)) 103 #define PFIL_WUNLOCK(p) rm_wunlock(&(p)->ph_lock) 104 #define PFIL_LIST_LOCK() mtx_lock(&pfil_global_lock) 105 #define PFIL_LIST_UNLOCK() mtx_unlock(&pfil_global_lock) 106 107 static __inline struct packet_filter_hook * 108 pfil_hook_get(int dir, struct pfil_head *ph) 109 { 110 if (dir == PFIL_IN) 111 return (TAILQ_FIRST(&ph->ph_in)); 112 else if (dir == PFIL_OUT) 113 return (TAILQ_FIRST(&ph->ph_out)); 114 else 115 return (NULL); 116 } 117 118 #endif /* _NET_PFIL_H_ */ 119