/* $FreeBSD$ */
/* $NetBSD: pfil.h,v 1.22 2003/06/23 12:57:08 martin Exp $ */
/*-
* Copyright (c) 1996 Matthew R. Green
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _NET_PFIL_H_
#define _NET_PFIL_H_
#include <sys/systm.h>
#include <sys/queue.h>
#include <sys/_lock.h>
#include <sys/_mutex.h>
#include <sys/lock.h>
#include <sys/rmlock.h>
struct mbuf;
struct ifnet;
struct inpcb;
typedef int (*pfil_func_t)(void *, struct mbuf **, struct ifnet *, int,
struct inpcb *);
/*
* The packet filter hooks are designed for anything to call them to
* possibly intercept the packet. Multiple filter hooks are chained
* together and after each other in the specified order.
*/
struct packet_filter_hook {
TAILQ_ENTRY(packet_filter_hook) pfil_chain;
pfil_func_t pfil_func;
void *pfil_arg;
};
#define PFIL_IN 0x00000001
#define PFIL_OUT 0x00000002
#define PFIL_WAITOK 0x00000004
#define PFIL_ALL (PFIL_IN|PFIL_OUT)
typedef TAILQ_HEAD(pfil_chain, packet_filter_hook) pfil_chain_t;
#define PFIL_TYPE_AF 1 /* key is AF_* type */
#define PFIL_TYPE_IFNET 2 /* key is ifnet pointer */
#define PFIL_FLAG_PRIVATE_LOCK 0x01 /* Personal lock instead of global */
/*
* A pfil head is created by each protocol or packet intercept point.
* For packet is then run through the hook chain for inspection.
*/
struct pfil_head {
pfil_chain_t ph_in;
pfil_chain_t ph_out;
int ph_type;
int ph_nhooks;
#if defined( __linux__ ) || defined( _WIN32 )
rwlock_t ph_mtx;
#else
struct rmlock *ph_plock; /* Pointer to the used lock */
struct rmlock ph_lock; /* Private lock storage */
int flags;
#endif
union {
u_long phu_val;
void *phu_ptr;
} ph_un;
#define ph_af ph_un.phu_val
#define ph_ifnet ph_un.phu_ptr
LIST_ENTRY(pfil_head) ph_list;
};
/* Public functions for pfil hook management by packet filters. */
struct pfil_head *pfil_head_get(int, u_long);
int pfil_add_hook(pfil_func_t, void *, int, struct pfil_head *);
int pfil_remove_hook(pfil_func_t, void *, int, struct pfil_head *);
#define PFIL_HOOKED(p) ((p)->ph_nhooks > 0)
/* Public functions to run the packet inspection by protocols. */
int pfil_run_hooks(struct pfil_head *, struct mbuf **, struct ifnet *,
int, struct inpcb *inp);
/* Public functions for pfil head management by protocols. */
int pfil_head_register(struct pfil_head *);
int pfil_head_unregister(struct pfil_head *);
/* Public pfil locking functions for self managed locks by packet filters. */
struct rm_priotracker; /* Do not require including rmlock header */
int pfil_try_rlock(struct pfil_head *, struct rm_priotracker *);
void pfil_rlock(struct pfil_head *, struct rm_priotracker *);
void pfil_runlock(struct pfil_head *, struct rm_priotracker *);
void pfil_wlock(struct pfil_head *);
void pfil_wunlock(struct pfil_head *);
int pfil_wowned(struct pfil_head *ph);
/* Internal pfil locking functions. */
#define PFIL_LOCK_INIT_REAL(l, t) \
rm_init_flags(l, "PFil " t " rmlock", RM_RECURSE)
#define PFIL_LOCK_DESTROY_REAL(l) \
rm_destroy(l)
#define PFIL_LOCK_INIT(p) do { \
if ((p)->flags & PFIL_FLAG_PRIVATE_LOCK) { \
PFIL_LOCK_INIT_REAL(&(p)->ph_lock, "private"); \
(p)->ph_plock = &(p)->ph_lock; \
} else \
(p)->ph_plock = &V_pfil_lock; \
} while (0)
#define PFIL_LOCK_DESTROY(p) do { \
if ((p)->flags & PFIL_FLAG_PRIVATE_LOCK) \
PFIL_LOCK_DESTROY_REAL((p)->ph_plock); \
} while (0)
#define PFIL_TRY_RLOCK(p, t) rm_try_rlock((p)->ph_plock, (t))
#define PFIL_RLOCK(p, t) rm_rlock((p)->ph_plock, (t))
#define PFIL_WLOCK(p) rm_wlock((p)->ph_plock)
#define PFIL_RUNLOCK(p, t) rm_runlock((p)->ph_plock, (t))
#define PFIL_WUNLOCK(p) rm_wunlock((p)->ph_plock)
#define PFIL_WOWNED(p) rm_wowned((p)->ph_plock)
/* Internal locking macros for global/vnet pfil_head_list. */
#define PFIL_HEADLIST_LOCK() mtx_lock(&pfil_global_lock)
#define PFIL_HEADLIST_UNLOCK() mtx_unlock(&pfil_global_lock)
#endif /* _NET_PFIL_H_ */
