diff options
Diffstat (limited to 'sys/net/bpf_buffer.c')
| -rw-r--r-- | sys/net/bpf_buffer.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/sys/net/bpf_buffer.c b/sys/net/bpf_buffer.c new file mode 100644 index 0000000..74e1ae4 --- /dev/null +++ b/sys/net/bpf_buffer.c @@ -0,0 +1,224 @@ +/*- + * 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. + * 4. 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/malloc.h> +#include <sys/mbuf.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> + +#define PRINET 26 /* interruptible */ + +/* + * 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; + u_int count; + + m = (struct mbuf *)src; + dst = (u_char *)buf + offset; + while (len > 0) { + if (m == NULL) + panic("bpf_mcopy"); + count = min(m->m_len, len); + bcopy(mtod(m, void *), dst, count); + m = m->m_next; + dst += count; + len -= count; + } +} + +/* + * 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); + } + + while (d->bd_hbuf_in_use) + mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, + PRINET, "bd_hbuf", 0); + /* 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)); +} |
