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c7b0200eb5
Eliminate bpf_buffer_alloc() and allocate BPF buffers on descriptor creation and BIOCSBLEN ioctl. This permits us not to allocate buffers inside bpf_attachd() which is protected by global lock. Approved by: kib(mentor) MFC in: 4 weeks
220 lines
6.5 KiB
C
220 lines
6.5 KiB
C
/*-
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* Copyright (c) 2007 Seccuris Inc.
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* All rights reserved.
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*
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* This software was developed by Robert N. M. Watson under contract to
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* Seccuris Inc.
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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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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, 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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* Copyright (c) 1990, 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from the Stanford/CMU enet packet filter,
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* (net/enet.c) distributed as part of 4.3BSD, and code contributed
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* to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
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* Berkeley Laboratory.
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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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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, 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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* @(#)bpf.c 8.4 (Berkeley) 1/9/95
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_bpf.h"
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#include <sys/param.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.h>
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#include <sys/socket.h>
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#include <sys/uio.h>
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#include <sys/kernel.h>
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#include <sys/sysctl.h>
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#include <net/if.h>
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#include <net/bpf.h>
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#include <net/bpf_buffer.h>
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#include <net/bpfdesc.h>
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/*
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* Implement historical kernel memory buffering model for BPF: two malloc(9)
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* kernel buffers are hung off of the descriptor. The size is fixed prior to
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* attaching to an ifnet, ad cannot be changed after that. read(2) simply
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* copies the data to user space using uiomove(9).
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*/
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static int bpf_bufsize = 4096;
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SYSCTL_INT(_net_bpf, OID_AUTO, bufsize, CTLFLAG_RW,
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&bpf_bufsize, 0, "Default capture buffer size in bytes");
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static int bpf_maxbufsize = BPF_MAXBUFSIZE;
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SYSCTL_INT(_net_bpf, OID_AUTO, maxbufsize, CTLFLAG_RW,
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&bpf_maxbufsize, 0, "Maximum capture buffer in bytes");
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/*
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* Simple data copy to the current kernel buffer.
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*/
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void
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bpf_buffer_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset,
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void *src, u_int len)
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{
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u_char *src_bytes;
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src_bytes = (u_char *)src;
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bcopy(src_bytes, buf + offset, len);
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}
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/*
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* Scatter-gather data copy from an mbuf chain to the current kernel buffer.
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*/
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void
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bpf_buffer_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
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u_int len)
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{
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const struct mbuf *m;
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u_char *dst;
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u_int count;
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m = (struct mbuf *)src;
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dst = (u_char *)buf + offset;
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while (len > 0) {
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if (m == NULL)
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panic("bpf_mcopy");
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count = min(m->m_len, len);
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bcopy(mtod(m, void *), dst, count);
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m = m->m_next;
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dst += count;
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len -= count;
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}
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}
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/*
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* Free BPF kernel buffers on device close.
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*/
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void
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bpf_buffer_free(struct bpf_d *d)
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{
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if (d->bd_sbuf != NULL)
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free(d->bd_sbuf, M_BPF);
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if (d->bd_hbuf != NULL)
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free(d->bd_hbuf, M_BPF);
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if (d->bd_fbuf != NULL)
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free(d->bd_fbuf, M_BPF);
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#ifdef INVARIANTS
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d->bd_sbuf = d->bd_hbuf = d->bd_fbuf = (caddr_t)~0;
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#endif
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}
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/*
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* This is a historical initialization that occurs when the BPF descriptor is
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* first opened. It does not imply selection of a buffer mode, so we don't
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* allocate buffers here.
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*/
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void
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bpf_buffer_init(struct bpf_d *d)
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{
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d->bd_bufsize = bpf_bufsize;
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}
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/*
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* Allocate or resize buffers.
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*/
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int
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bpf_buffer_ioctl_sblen(struct bpf_d *d, u_int *i)
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{
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u_int size;
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caddr_t fbuf, sbuf;
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size = *i;
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if (size > bpf_maxbufsize)
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*i = size = bpf_maxbufsize;
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else if (size < BPF_MINBUFSIZE)
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*i = size = BPF_MINBUFSIZE;
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/* Allocate buffers immediately */
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fbuf = (caddr_t)malloc(size, M_BPF, M_WAITOK);
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sbuf = (caddr_t)malloc(size, M_BPF, M_WAITOK);
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BPFD_LOCK(d);
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if (d->bd_bif != NULL) {
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/* Interface already attached, unable to change buffers */
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BPFD_UNLOCK(d);
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free(fbuf, M_BPF);
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free(sbuf, M_BPF);
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return (EINVAL);
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}
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/* Free old buffers if set */
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if (d->bd_fbuf != NULL)
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free(d->bd_fbuf, M_BPF);
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if (d->bd_sbuf != NULL)
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free(d->bd_sbuf, M_BPF);
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/* Fill in new data */
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d->bd_bufsize = size;
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d->bd_fbuf = fbuf;
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d->bd_sbuf = sbuf;
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d->bd_hbuf = NULL;
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d->bd_slen = 0;
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d->bd_hlen = 0;
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BPFD_UNLOCK(d);
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return (0);
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}
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/*
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* Copy buffer storage to user space in read().
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*/
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int
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bpf_buffer_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio)
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{
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return (uiomove(buf, len, uio));
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}
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