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 }; 56 57 #define PFIL_IN 0x00000001 58 #define PFIL_OUT 0x00000002 59 #define PFIL_WAITOK 0x00000004 60 #define PFIL_ALL (PFIL_IN|PFIL_OUT) 61 62 typedef TAILQ_HEAD(pfil_list, packet_filter_hook) pfil_list_t; 63 64 #define PFIL_TYPE_AF 1 /* key is AF_* type */ 65 #define PFIL_TYPE_IFNET 2 /* key is ifnet pointer */ 66 67 #define PFIL_FLAG_PRIVATE_LOCK 0x01 /* Personal lock instead of global */ 68 69 struct pfil_head { 70 pfil_list_t ph_in; 71 pfil_list_t ph_out; 72 int ph_type; 73 int ph_nhooks; 74 #if defined( __linux__ ) || defined( _WIN32 ) 75 rwlock_t ph_mtx; 76 #else 77 struct rmlock *ph_plock; /* Pointer to the used lock */ 78 struct rmlock ph_lock; /* Private lock storage */ 79 int flags; 80 #endif 81 union { 82 u_long phu_val; 83 void *phu_ptr; 84 } ph_un; 85 #define ph_af ph_un.phu_val 86 #define ph_ifnet ph_un.phu_ptr 87 LIST_ENTRY(pfil_head) ph_list; 88 }; 89 90 int pfil_add_hook(int (*func)(void *, struct mbuf **, struct ifnet *, 91 int, struct inpcb *), void *, int, struct pfil_head *); 92 int pfil_remove_hook(int (*func)(void *, struct mbuf **, struct ifnet *, 93 int, struct inpcb *), void *, int, struct pfil_head *); 94 int pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *, 95 int, struct inpcb *inp); 96 97 struct rm_priotracker; /* Do not require including rmlock header */ 98 int pfil_try_rlock(struct pfil_head *, struct rm_priotracker *); 99 void pfil_rlock(struct pfil_head *, struct rm_priotracker *); 100 void pfil_runlock(struct pfil_head *, struct rm_priotracker *); 101 void pfil_wlock(struct pfil_head *); 102 void pfil_wunlock(struct pfil_head *); 103 int pfil_wowned(struct pfil_head *ph); 104 105 int pfil_head_register(struct pfil_head *); 106 int pfil_head_unregister(struct pfil_head *); 107 108 struct pfil_head *pfil_head_get(int, u_long); 109 110 #define PFIL_HOOKED(p) ((p)->ph_nhooks > 0) 111 #define PFIL_LOCK_INIT_REAL(l, t) \ 112 rm_init_flags(l, "PFil " t " rmlock", RM_RECURSE) 113 #define PFIL_LOCK_DESTROY_REAL(l) \ 114 rm_destroy(l) 115 #define PFIL_LOCK_INIT(p) do { \ 116 if ((p)->flags & PFIL_FLAG_PRIVATE_LOCK) { \ 117 PFIL_LOCK_INIT_REAL(&(p)->ph_lock, "private"); \ 118 (p)->ph_plock = &(p)->ph_lock; \ 119 } else \ 120 (p)->ph_plock = &V_pfil_lock; \ 121 } while (0) 122 #define PFIL_LOCK_DESTROY(p) do { \ 123 if ((p)->flags & PFIL_FLAG_PRIVATE_LOCK) \ 124 PFIL_LOCK_DESTROY_REAL((p)->ph_plock); \ 125 } while (0) 126 #define PFIL_TRY_RLOCK(p, t) rm_try_rlock((p)->ph_plock, (t)) 127 #define PFIL_RLOCK(p, t) rm_rlock((p)->ph_plock, (t)) 128 #define PFIL_WLOCK(p) rm_wlock((p)->ph_plock) 129 #define PFIL_RUNLOCK(p, t) rm_runlock((p)->ph_plock, (t)) 130 #define PFIL_WUNLOCK(p) rm_wunlock((p)->ph_plock) 131 #define PFIL_WOWNED(p) rm_wowned((p)->ph_plock) 132 #define PFIL_LIST_LOCK() mtx_lock(&pfil_global_lock) 133 #define PFIL_LIST_UNLOCK() mtx_unlock(&pfil_global_lock) 134 135 static __inline struct packet_filter_hook * 136 pfil_hook_get(int dir, struct pfil_head *ph) 137 { 138 139 if (dir == PFIL_IN) 140 return (TAILQ_FIRST(&ph->ph_in)); 141 else if (dir == PFIL_OUT) 142 return (TAILQ_FIRST(&ph->ph_out)); 143 else 144 return (NULL); 145 } 146 147 #endif /* _NET_PFIL_H_ */ 148