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/condvar.h> /* XXX */ 40 41 struct mbuf; 42 struct ifnet; 43 44 /* 45 * The packet filter hooks are designed for anything to call them to 46 * possibly intercept the packet. 47 */ 48 struct packet_filter_hook { 49 TAILQ_ENTRY(packet_filter_hook) pfil_link; 50 int (*pfil_func)(void *, struct mbuf **, struct ifnet *, int); 51 void *pfil_arg; 52 int pfil_flags; 53 }; 54 55 #define PFIL_IN 0x00000001 56 #define PFIL_OUT 0x00000002 57 #define PFIL_WAITOK 0x00000004 58 #define PFIL_ALL (PFIL_IN|PFIL_OUT) 59 60 typedef TAILQ_HEAD(pfil_list, packet_filter_hook) pfil_list_t; 61 62 #define PFIL_TYPE_AF 1 /* key is AF_* type */ 63 #define PFIL_TYPE_IFNET 2 /* key is ifnet pointer */ 64 65 struct pfil_head { 66 pfil_list_t ph_in; 67 pfil_list_t ph_out; 68 int ph_type; 69 /* 70 * Locking: use a busycounter per pfil_head. 71 * Use ph_busy_count = -1 to indicate pfil_head is empty. 72 */ 73 int ph_busy_count; /* count of threads with read lock */ 74 int ph_want_write; /* want write lock flag */ 75 struct cv ph_cv; /* for waking up writers */ 76 struct mtx ph_mtx; /* mutex on locking state */ 77 union { 78 u_long phu_val; 79 void *phu_ptr; 80 } ph_un; 81 #define ph_af ph_un.phu_val 82 #define ph_ifnet ph_un.phu_ptr 83 LIST_ENTRY(pfil_head) ph_list; 84 }; 85 86 int pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *, 87 int); 88 89 int pfil_add_hook(int (*func)(void *, struct mbuf **, 90 struct ifnet *, int), void *, int, struct pfil_head *); 91 int pfil_remove_hook(int (*func)(void *, struct mbuf **, 92 struct ifnet *, int), void *, int, struct pfil_head *); 93 94 int pfil_head_register(struct pfil_head *); 95 int pfil_head_unregister(struct pfil_head *); 96 97 struct pfil_head *pfil_head_get(int, u_long); 98 99 static __inline struct packet_filter_hook * 100 pfil_hook_get(int dir, struct pfil_head *ph) 101 { 102 KASSERT(ph->ph_busy_count > 0, 103 ("pfil_hook_get: called on unbusy pfil_head")); 104 if (dir == PFIL_IN) 105 return (TAILQ_FIRST(&ph->ph_in)); 106 else if (dir == PFIL_OUT) 107 return (TAILQ_FIRST(&ph->ph_out)); 108 else 109 return (NULL); 110 } 111 112 #endif /* _NET_PFIL_H_ */ 113