/*- * 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. */ #include <sys/cdefs.h> #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)); }
