/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2007 Seccuris Inc.
* All rights reserved.
*
* This software was developed by Robert N. M. Watson under contract to
* Seccuris Inc.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* Copyright (c) 1990, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from the Stanford/CMU enet packet filter,
* (net/enet.c) distributed as part of 4.3BSD, and code contributed
* to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
* Berkeley Laboratory.
*
* 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 University 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 REGENTS 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 REGENTS 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.
*
* @(#)bpf.c 8.4 (Berkeley) 1/9/95
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_bpf.h"
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/bpf.h>
#include <net/bpf_buffer.h>
#include <net/bpfdesc.h>
/*
* Implement historical kernel memory buffering model for BPF: two malloc(9)
* kernel buffers are hung off of the descriptor. The size is fixed prior to
* attaching to an ifnet, ad cannot be changed after that. read(2) simply
* copies the data to user space using uiomove(9).
*/
static int bpf_bufsize = 4096;
SYSCTL_INT(_net_bpf, OID_AUTO, bufsize, CTLFLAG_RW,
&bpf_bufsize, 0, "Default capture buffer size in bytes");
static int bpf_maxbufsize = BPF_MAXBUFSIZE;
SYSCTL_INT(_net_bpf, OID_AUTO, maxbufsize, CTLFLAG_RW,
&bpf_maxbufsize, 0, "Maximum capture buffer in bytes");
/*
* Simple data copy to the current kernel buffer.
*/
void
bpf_buffer_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset,
void *src, u_int len)
{
u_char *src_bytes;
src_bytes = (u_char *)src;
bcopy(src_bytes, buf + offset, len);
}
/*
* Scatter-gather data copy from an mbuf chain to the current kernel buffer.
*/
void
bpf_buffer_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
u_int len)
{
const struct mbuf *m;
u_char *dst;
m = (struct mbuf *)src;
dst = (u_char *)buf + offset;
m_copydata(m, 0, len, dst);
}
/*
* Free BPF kernel buffers on device close.
*/
void
bpf_buffer_free(struct bpf_d *d)
{
if (d->bd_sbuf != NULL)
free(d->bd_sbuf, M_BPF);
if (d->bd_hbuf != NULL)
free(d->bd_hbuf, M_BPF);
if (d->bd_fbuf != NULL)
free(d->bd_fbuf, M_BPF);
#ifdef INVARIANTS
d->bd_sbuf = d->bd_hbuf = d->bd_fbuf = (caddr_t)~0;
#endif
}
/*
* This is a historical initialization that occurs when the BPF descriptor is
* first opened. It does not imply selection of a buffer mode, so we don't
* allocate buffers here.
*/
void
bpf_buffer_init(struct bpf_d *d)
{
d->bd_bufsize = bpf_bufsize;
}
/*
* Allocate or resize buffers.
*/
int
bpf_buffer_ioctl_sblen(struct bpf_d *d, u_int *i)
{
u_int size;
caddr_t fbuf, sbuf;
size = *i;
if (size > bpf_maxbufsize)
*i = size = bpf_maxbufsize;
else if (size < BPF_MINBUFSIZE)
*i = size = BPF_MINBUFSIZE;
/* Allocate buffers immediately */
fbuf = (caddr_t)malloc(size, M_BPF, M_WAITOK);
sbuf = (caddr_t)malloc(size, M_BPF, M_WAITOK);
BPFD_LOCK(d);
if (d->bd_bif != NULL) {
/* Interface already attached, unable to change buffers */
BPFD_UNLOCK(d);
free(fbuf, M_BPF);
free(sbuf, M_BPF);
return (EINVAL);
}
/* Free old buffers if set */
if (d->bd_fbuf != NULL)
free(d->bd_fbuf, M_BPF);
if (d->bd_sbuf != NULL)
free(d->bd_sbuf, M_BPF);
/* Fill in new data */
d->bd_bufsize = size;
d->bd_fbuf = fbuf;
d->bd_sbuf = sbuf;
d->bd_hbuf = NULL;
d->bd_slen = 0;
d->bd_hlen = 0;
BPFD_UNLOCK(d);
return (0);
}
/*
* Copy buffer storage to user space in read().
*/
int
bpf_buffer_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio)
{
return (uiomove(buf, len, uio));
}
