2 * Copyright (c) 2007 Seccuris Inc.
5 * This software was developed by Robert N. M. Watson under contract to
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * Copyright (c) 1990, 1991, 1993
30 * The Regents of the University of California. All rights reserved.
32 * This code is derived from the Stanford/CMU enet packet filter,
33 * (net/enet.c) distributed as part of 4.3BSD, and code contributed
34 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
35 * Berkeley Laboratory.
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 * 4. Neither the name of the University nor the names of its contributors
46 * may be used to endorse or promote products derived from this software
47 * without specific prior written permission.
49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61 * @(#)bpf.c 8.4 (Berkeley) 1/9/95
64 #include <sys/cdefs.h>
65 __FBSDID("$FreeBSD$");
69 #include <sys/param.h>
70 #include <sys/malloc.h>
72 #include <sys/socket.h>
74 #include <sys/kernel.h>
75 #include <sys/sysctl.h>
79 #include <net/bpf_buffer.h>
80 #include <net/bpfdesc.h>
83 * Implement historical kernel memory buffering model for BPF: two malloc(9)
84 * kernel buffers are hung off of the descriptor. The size is fixed prior to
85 * attaching to an ifnet, ad cannot be changed after that. read(2) simply
86 * copies the data to user space using uiomove(9).
89 static int bpf_bufsize = 4096;
90 SYSCTL_INT(_net_bpf, OID_AUTO, bufsize, CTLFLAG_RW,
91 &bpf_bufsize, 0, "Default capture buffer size in bytes");
92 static int bpf_maxbufsize = BPF_MAXBUFSIZE;
93 SYSCTL_INT(_net_bpf, OID_AUTO, maxbufsize, CTLFLAG_RW,
94 &bpf_maxbufsize, 0, "Maximum capture buffer in bytes");
97 bpf_buffer_alloc(struct bpf_d *d)
100 KASSERT(d->bd_fbuf == NULL, ("bpf_buffer_alloc: bd_fbuf != NULL"));
101 KASSERT(d->bd_sbuf == NULL, ("bpf_buffer_alloc: bd_sbuf != NULL"));
102 KASSERT(d->bd_hbuf == NULL, ("bpf_buffer_alloc: bd_hbuf != NULL"));
104 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK);
105 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK);
112 * Simple data copy to the current kernel buffer.
115 bpf_buffer_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset,
116 void *src, u_int len)
120 src_bytes = (u_char *)src;
121 bcopy(src_bytes, buf + offset, len);
125 * Scatter-gather data copy from an mbuf chain to the current kernel buffer.
128 bpf_buffer_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
131 const struct mbuf *m;
135 m = (struct mbuf *)src;
136 dst = (u_char *)buf + offset;
140 count = min(m->m_len, len);
141 bcopy(mtod(m, void *), dst, count);
149 * Free BPF kernel buffers on device close.
152 bpf_buffer_free(struct bpf_d *d)
155 if (d->bd_sbuf != NULL)
156 free(d->bd_sbuf, M_BPF);
157 if (d->bd_hbuf != NULL)
158 free(d->bd_hbuf, M_BPF);
159 if (d->bd_fbuf != NULL)
160 free(d->bd_fbuf, M_BPF);
163 d->bd_sbuf = d->bd_hbuf = d->bd_fbuf = (caddr_t)~0;
168 * This is a historical initialization that occurs when the BPF descriptor is
169 * first opened. It does not imply selection of a buffer mode, so we don't
170 * allocate buffers here.
173 bpf_buffer_init(struct bpf_d *d)
176 d->bd_bufsize = bpf_bufsize;
180 * Allocate or resize buffers.
183 bpf_buffer_ioctl_sblen(struct bpf_d *d, u_int *i)
188 if (d->bd_bif != NULL) {
193 if (size > bpf_maxbufsize)
194 *i = size = bpf_maxbufsize;
195 else if (size < BPF_MINBUFSIZE)
196 *i = size = BPF_MINBUFSIZE;
197 d->bd_bufsize = size;
203 * Copy buffer storage to user space in read().
206 bpf_buffer_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio)
209 return (uiomove(buf, len, uio));