caf32b260a
The 0b70e3e78b changed the original design of a single entry point
into pfil(9) chains providing separate functions for the filtering
points that always provide mbufs and know the direction of a flow.
The motivation was to reduce branching. The logical continuation
would be to do the same for the filtering points that always provide
a memory pointer and retire the single entry point.
o Hooks now provide two functions: one for mbufs and optional for
memory pointers.
o pfil_hook_args() has a new member and pfil_add_hook() has a
requirement to zero out uninitialized data. Bump PFIL_VERSION.
o As it was before, a hook function for a memory pointer may realloc
into an mbuf. Such mbuf would be returned via a pointer that must
be provided in argument.
o The only hook that supports memory pointers is ipfw:default-link.
It is rewritten to provide two functions.
o All remaining uses of pfil_run_hooks() are converted to
pfil_mem_in().
o Transparent union of pfil_packet_t and tricks to fix pointer
alignment are retired. Internal pfil_realloc() reduces down to
m_devget() and thus is retired, too.
Reviewed by: mjg, ocochard
Differential revision: https://reviews.freebsd.org/D37977
196 lines
5.6 KiB
C
196 lines
5.6 KiB
C
/* $FreeBSD$ */
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/* $NetBSD: pfil.h,v 1.22 2003/06/23 12:57:08 martin Exp $ */
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/*-
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (c) 2019 Gleb Smirnoff <glebius@FreeBSD.org>
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* Copyright (c) 1996 Matthew R. Green
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef _NET_PFIL_H_
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#define _NET_PFIL_H_
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#include <sys/ioccom.h>
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enum pfil_types {
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PFIL_TYPE_IP4,
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PFIL_TYPE_IP6,
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PFIL_TYPE_ETHERNET,
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};
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#define MAXPFILNAME 64
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struct pfilioc_head {
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char pio_name[MAXPFILNAME];
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int pio_nhooksin;
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int pio_nhooksout;
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enum pfil_types pio_type;
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};
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struct pfilioc_hook {
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char pio_module[MAXPFILNAME];
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char pio_ruleset[MAXPFILNAME];
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int pio_flags;
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enum pfil_types pio_type;
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};
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struct pfilioc_list {
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u_int pio_nheads;
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u_int pio_nhooks;
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struct pfilioc_head *pio_heads;
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struct pfilioc_hook *pio_hooks;
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};
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struct pfilioc_link {
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char pio_name[MAXPFILNAME];
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char pio_module[MAXPFILNAME];
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char pio_ruleset[MAXPFILNAME];
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int pio_flags;
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};
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#define PFILDEV "pfil"
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#define PFILIOC_LISTHEADS _IOWR('P', 1, struct pfilioc_list)
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#define PFILIOC_LISTHOOKS _IOWR('P', 2, struct pfilioc_list)
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#define PFILIOC_LINK _IOW('P', 3, struct pfilioc_link)
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#define PFIL_IN 0x00010000
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#define PFIL_OUT 0x00020000
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/* UNUSED 0x00040000 */
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#define PFIL_DIR(f) ((f) & (PFIL_IN|PFIL_OUT))
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#define PFIL_HEADPTR 0x00100000
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#define PFIL_HOOKPTR 0x00200000
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#define PFIL_APPEND 0x00400000
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#define PFIL_UNLINK 0x00800000
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#ifdef _KERNEL
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struct mbuf;
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struct ifnet;
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struct inpcb;
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typedef enum {
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PFIL_PASS = 0,
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PFIL_DROPPED,
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PFIL_CONSUMED,
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PFIL_REALLOCED,
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} pfil_return_t;
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typedef pfil_return_t (*pfil_mbuf_chk_t)(struct mbuf **, struct ifnet *, int,
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void *, struct inpcb *);
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typedef pfil_return_t (*pfil_mem_chk_t)(void *, u_int, int, struct ifnet *,
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void *, struct mbuf **);
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/*
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* A pfil head is created by a packet intercept point.
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*
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* A pfil hook is created by a packet filter.
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*
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* Hooks are chained on heads. Historically some hooking happens
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* automatically, e.g. ipfw(4), pf(4) and ipfilter(4) would register
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* theirselves on IPv4 and IPv6 input/output.
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*/
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typedef struct pfil_hook * pfil_hook_t;
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typedef struct pfil_head * pfil_head_t;
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/*
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* Give us a chance to modify pfil_xxx_args structures in future.
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*/
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#define PFIL_VERSION 2
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/* Argument structure used by packet filters to register themselves. */
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struct pfil_hook_args {
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int pa_version;
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int pa_flags;
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enum pfil_types pa_type;
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pfil_mbuf_chk_t pa_mbuf_chk;
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pfil_mem_chk_t pa_mem_chk;
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void *pa_ruleset;
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const char *pa_modname;
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const char *pa_rulname;
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};
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/* Public functions for pfil hook management by packet filters. */
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pfil_hook_t pfil_add_hook(struct pfil_hook_args *);
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void pfil_remove_hook(pfil_hook_t);
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/* Argument structure used by ioctl() and packet filters to set filters. */
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struct pfil_link_args {
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int pa_version;
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int pa_flags;
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union {
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const char *pa_headname;
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pfil_head_t pa_head;
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};
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union {
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struct {
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const char *pa_modname;
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const char *pa_rulname;
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};
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pfil_hook_t pa_hook;
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};
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};
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/* Public function to configure filter chains. Used by ioctl() and filters. */
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int pfil_link(struct pfil_link_args *);
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/* Argument structure used by inspection points to register themselves. */
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struct pfil_head_args {
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int pa_version;
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int pa_flags;
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enum pfil_types pa_type;
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const char *pa_headname;
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};
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/* Public functions for pfil head management by inspection points. */
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pfil_head_t pfil_head_register(struct pfil_head_args *);
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void pfil_head_unregister(pfil_head_t);
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/* Public functions to run the packet inspection by inspection points. */
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int pfil_mem_in(struct pfil_head *, void *, u_int, struct ifnet *,
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struct mbuf **);
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int pfil_mem_out(struct pfil_head *, void *, u_int, struct ifnet *,
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struct mbuf **);
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int pfil_mbuf_in(struct pfil_head *, struct mbuf **, struct ifnet *,
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struct inpcb *inp);
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int pfil_mbuf_out(struct pfil_head *, struct mbuf **, struct ifnet *,
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struct inpcb *inp);
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/*
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* Minimally exposed structure to avoid function call in case of absence
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* of any filters by protocols and macros to do the check.
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*/
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struct _pfil_head {
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int head_nhooksin;
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int head_nhooksout;
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};
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#define PFIL_HOOKED_IN(p) (((struct _pfil_head *)(p))->head_nhooksin > 0)
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#define PFIL_HOOKED_OUT(p) (((struct _pfil_head *)(p))->head_nhooksout > 0)
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#endif /* _KERNEL */
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#endif /* _NET_PFIL_H_ */
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