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freebsd/sys/net/bpf_jitter.c
Jung-uk Kim 06302de20d Initialize scratch memory for JIT-compiled filter when it is allocated.
Previously it may have contained unnecessary (even sensitive) data from
the previous allocation.
As a (good) side effect, scratch memory may be used to store the previous
filter state(s) safely because it is allocated and freed with filter itself.
However, use it carefully because bpf_filter(9) does not have this behavior.

MFC after:	3 days
2008-08-28 16:40:51 +00:00

142 lines
3.8 KiB
C

/*-
* Copyright (C) 2002-2003 NetGroup, Politecnico di Torino (Italy)
* Copyright (C) 2005-2008 Jung-uk Kim <jkim@FreeBSD.org>
* 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. Neither the name of the Politecnico di Torino nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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 COPYRIGHT
* OWNER OR CONTRIBUTORS 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#ifdef _KERNEL
#include "opt_bpf.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/sysctl.h>
#else
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#endif
#include <net/bpf.h>
#include <net/bpf_jitter.h>
bpf_filter_func bpf_jit_compile(struct bpf_insn *, u_int, int *);
static u_int bpf_jit_accept_all(u_char *, u_int, u_int);
#ifdef _KERNEL
MALLOC_DEFINE(M_BPFJIT, "BPF_JIT", "BPF JIT compiler");
SYSCTL_NODE(_net, OID_AUTO, bpf_jitter, CTLFLAG_RW, 0, "BPF JIT compiler");
int bpf_jitter_enable = 1;
SYSCTL_INT(_net_bpf_jitter, OID_AUTO, enable, CTLFLAG_RW,
&bpf_jitter_enable, 0, "enable BPF JIT compiler");
bpf_jit_filter *
bpf_jitter(struct bpf_insn *fp, int nins)
{
bpf_jit_filter *filter;
/* Allocate the filter structure */
filter = (struct bpf_jit_filter *)malloc(sizeof(*filter),
M_BPFJIT, M_NOWAIT | M_ZERO);
if (filter == NULL)
return (NULL);
/* No filter means accept all */
if (fp == NULL || nins == 0) {
filter->func = bpf_jit_accept_all;
return (filter);
}
/* Create the binary */
if ((filter->func = bpf_jit_compile(fp, nins, filter->mem)) == NULL) {
free(filter, M_BPFJIT);
return (NULL);
}
return (filter);
}
void
bpf_destroy_jit_filter(bpf_jit_filter *filter)
{
if (filter->func != bpf_jit_accept_all)
free(filter->func, M_BPFJIT);
free(filter, M_BPFJIT);
}
#else
bpf_jit_filter *
bpf_jitter(struct bpf_insn *fp, int nins)
{
bpf_jit_filter *filter;
/* Allocate the filter structure */
filter = (struct bpf_jit_filter *)malloc(sizeof(*filter));
if (filter == NULL)
return (NULL);
memset(filter, 0, sizeof(*filter));
/* No filter means accept all */
if (fp == NULL || nins == 0) {
filter->func = bpf_jit_accept_all;
return (filter);
}
/* Create the binary */
if ((filter->func = bpf_jit_compile(fp, nins, filter->mem)) == NULL) {
free(filter);
return (NULL);
}
return (filter);
}
void
bpf_destroy_jit_filter(bpf_jit_filter *filter)
{
if (filter->func != bpf_jit_accept_all)
free(filter->func);
free(filter);
}
#endif
static u_int
bpf_jit_accept_all(__unused u_char *p, __unused u_int wirelen,
__unused u_int buflen)
{
return ((u_int)-1);
}