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 typedef int (*pfil_func_t)(void *, struct mbuf **, struct ifnet *, int, 47 struct inpcb *); 48 49 /* 50 * The packet filter hooks are designed for anything to call them to 51 * possibly intercept the packet. Multiple filter hooks are chained 52 * together and after each other in the specified order. 53 */ 54 struct packet_filter_hook { 55 TAILQ_ENTRY(packet_filter_hook) pfil_chain; 56 pfil_func_t pfil_func; 57 void *pfil_arg; 58 }; 59 60 #define PFIL_IN 0x00000001 61 #define PFIL_OUT 0x00000002 62 #define PFIL_WAITOK 0x00000004 63 #define PFIL_ALL (PFIL_IN|PFIL_OUT) 64 65 typedef TAILQ_HEAD(pfil_chain, packet_filter_hook) pfil_chain_t; 66 67 #define PFIL_TYPE_AF 1 /* key is AF_* type */ 68 #define PFIL_TYPE_IFNET 2 /* key is ifnet pointer */ 69 70 #define PFIL_FLAG_PRIVATE_LOCK 0x01 /* Personal lock instead of global */ 71 72 /* 73 * A pfil head is created by each protocol or packet intercept point. 74 * For packet is then run through the hook chain for inspection. 75 */ 76 struct pfil_head { 77 pfil_chain_t ph_in; 78 pfil_chain_t ph_out; 79 int ph_type; 80 int ph_nhooks; 81 #if defined( __linux__ ) || defined( _WIN32 ) 82 rwlock_t ph_mtx; 83 #else 84 struct rmlock *ph_plock; /* Pointer to the used lock */ 85 struct rmlock ph_lock; /* Private lock storage */ 86 int flags; 87 #endif 88 union { 89 u_long phu_val; 90 void *phu_ptr; 91 } ph_un; 92 #define ph_af ph_un.phu_val 93 #define ph_ifnet ph_un.phu_ptr 94 LIST_ENTRY(pfil_head) ph_list; 95 }; 96 97 /* Public functions for pfil hook management by packet filters. */ 98 struct pfil_head *pfil_head_get(int, u_long); 99 int pfil_add_hook(pfil_func_t, void *, int, struct pfil_head *); 100 int pfil_remove_hook(pfil_func_t, void *, int, struct pfil_head *); 101 #define PFIL_HOOKED(p) ((p)->ph_nhooks > 0) 102 103 /* Public functions to run the packet inspection by protocols. */ 104 int pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *, 105 int, struct inpcb *inp); 106 107 /* Public functions for pfil head management by protocols. */ 108 int pfil_head_register(struct pfil_head *); 109 int pfil_head_unregister(struct pfil_head *); 110 111 /* Public pfil locking functions for self managed locks by packet filters. */ 112 struct rm_priotracker; /* Do not require including rmlock header */ 113 int pfil_try_rlock(struct pfil_head *, struct rm_priotracker *); 114 void pfil_rlock(struct pfil_head *, struct rm_priotracker *); 115 void pfil_runlock(struct pfil_head *, struct rm_priotracker *); 116 void pfil_wlock(struct pfil_head *); 117 void pfil_wunlock(struct pfil_head *); 118 int pfil_wowned(struct pfil_head *ph); 119 120 /* Internal pfil locking functions. */ 121 #define PFIL_LOCK_INIT_REAL(l, t) \ 122 rm_init_flags(l, "PFil " t " rmlock", RM_RECURSE) 123 #define PFIL_LOCK_DESTROY_REAL(l) \ 124 rm_destroy(l) 125 #define PFIL_LOCK_INIT(p) do { \ 126 if ((p)->flags & PFIL_FLAG_PRIVATE_LOCK) { \ 127 PFIL_LOCK_INIT_REAL(&(p)->ph_lock, "private"); \ 128 (p)->ph_plock = &(p)->ph_lock; \ 129 } else \ 130 (p)->ph_plock = &V_pfil_lock; \ 131 } while (0) 132 #define PFIL_LOCK_DESTROY(p) do { \ 133 if ((p)->flags & PFIL_FLAG_PRIVATE_LOCK) \ 134 PFIL_LOCK_DESTROY_REAL((p)->ph_plock); \ 135 } while (0) 136 137 #define PFIL_TRY_RLOCK(p, t) rm_try_rlock((p)->ph_plock, (t)) 138 #define PFIL_RLOCK(p, t) rm_rlock((p)->ph_plock, (t)) 139 #define PFIL_WLOCK(p) rm_wlock((p)->ph_plock) 140 #define PFIL_RUNLOCK(p, t) rm_runlock((p)->ph_plock, (t)) 141 #define PFIL_WUNLOCK(p) rm_wunlock((p)->ph_plock) 142 #define PFIL_WOWNED(p) rm_wowned((p)->ph_plock) 143 144 /* Internal locking macros for global/vnet pfil_head_list. */ 145 #define PFIL_HEADLIST_LOCK() mtx_lock(&pfil_global_lock) 146 #define PFIL_HEADLIST_UNLOCK() mtx_unlock(&pfil_global_lock) 147 148 #endif /* _NET_PFIL_H_ */ 149