sys/net/pfil.h

   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_ */