The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/net/bpf_buffer.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * SPDX-License-Identifier: BSD-3-Clause
    3  *
    4  * Copyright (c) 2007 Seccuris Inc.
    5  * All rights reserved.
    6  *
    7  * This software was developed by Robert N. M. Watson under contract to
    8  * Seccuris Inc.
    9  *
   10  * Redistribution and use in source and binary forms, with or without
   11  * modification, are permitted provided that the following conditions
   12  * are met:
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  * 2. Redistributions in binary form must reproduce the above copyright
   16  *    notice, this list of conditions and the following disclaimer in the
   17  *    documentation and/or other materials provided with the distribution.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  * Copyright (c) 1990, 1991, 1993
   32  *      The Regents of the University of California.  All rights reserved.
   33  *
   34  * This code is derived from the Stanford/CMU enet packet filter,
   35  * (net/enet.c) distributed as part of 4.3BSD, and code contributed
   36  * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
   37  * Berkeley Laboratory.
   38  *
   39  * Redistribution and use in source and binary forms, with or without
   40  * modification, are permitted provided that the following conditions
   41  * are met:
   42  * 1. Redistributions of source code must retain the above copyright
   43  *    notice, this list of conditions and the following disclaimer.
   44  * 2. Redistributions in binary form must reproduce the above copyright
   45  *    notice, this list of conditions and the following disclaimer in the
   46  *    documentation and/or other materials provided with the distribution.
   47  * 3. Neither the name of the University nor the names of its contributors
   48  *    may be used to endorse or promote products derived from this software
   49  *    without specific prior written permission.
   50  *
   51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   61  * SUCH DAMAGE.
   62  *
   63  *      @(#)bpf.c       8.4 (Berkeley) 1/9/95
   64  */
   65 
   66 #include <sys/cdefs.h>
   67 __FBSDID("$FreeBSD$");
   68 
   69 #include "opt_bpf.h"
   70 
   71 #include <sys/param.h>
   72 #include <sys/malloc.h>
   73 #include <sys/mbuf.h>
   74 #include <sys/socket.h>
   75 #include <sys/uio.h>
   76 #include <sys/kernel.h>
   77 #include <sys/sysctl.h>
   78 
   79 #include <net/if.h>
   80 #include <net/bpf.h>
   81 #include <net/bpf_buffer.h>
   82 #include <net/bpfdesc.h>
   83 
   84 /*
   85  * Implement historical kernel memory buffering model for BPF: two malloc(9)
   86  * kernel buffers are hung off of the descriptor.  The size is fixed prior to
   87  * attaching to an ifnet, ad cannot be changed after that.  read(2) simply
   88  * copies the data to user space using uiomove(9).
   89  */
   90 
   91 static int bpf_bufsize = 4096;
   92 SYSCTL_INT(_net_bpf, OID_AUTO, bufsize, CTLFLAG_RW,
   93     &bpf_bufsize, 0, "Default capture buffer size in bytes");
   94 static int bpf_maxbufsize = BPF_MAXBUFSIZE;
   95 SYSCTL_INT(_net_bpf, OID_AUTO, maxbufsize, CTLFLAG_RW,
   96     &bpf_maxbufsize, 0, "Maximum capture buffer in bytes");
   97 
   98 /*
   99  * Simple data copy to the current kernel buffer.
  100  */
  101 void
  102 bpf_buffer_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset,
  103     void *src, u_int len)
  104 {
  105         u_char *src_bytes;
  106 
  107         src_bytes = (u_char *)src;
  108         bcopy(src_bytes, buf + offset, len);
  109 }
  110 
  111 /*
  112  * Scatter-gather data copy from an mbuf chain to the current kernel buffer.
  113  */
  114 void
  115 bpf_buffer_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
  116     u_int len)
  117 {
  118         const struct mbuf *m;
  119         u_char *dst;
  120         u_int count;
  121 
  122         m = (struct mbuf *)src;
  123         dst = (u_char *)buf + offset;
  124         while (len > 0) {
  125                 if (m == NULL)
  126                         panic("bpf_mcopy");
  127                 count = min(m->m_len, len);
  128                 bcopy(mtod(m, void *), dst, count);
  129                 m = m->m_next;
  130                 dst += count;
  131                 len -= count;
  132         }
  133 }
  134 
  135 /*
  136  * Free BPF kernel buffers on device close.
  137  */
  138 void
  139 bpf_buffer_free(struct bpf_d *d)
  140 {
  141 
  142         if (d->bd_sbuf != NULL)
  143                 free(d->bd_sbuf, M_BPF);
  144         if (d->bd_hbuf != NULL)
  145                 free(d->bd_hbuf, M_BPF);
  146         if (d->bd_fbuf != NULL)
  147                 free(d->bd_fbuf, M_BPF);
  148 
  149 #ifdef INVARIANTS
  150         d->bd_sbuf = d->bd_hbuf = d->bd_fbuf = (caddr_t)~0;
  151 #endif
  152 }
  153 
  154 /*
  155  * This is a historical initialization that occurs when the BPF descriptor is
  156  * first opened.  It does not imply selection of a buffer mode, so we don't
  157  * allocate buffers here.
  158  */
  159 void
  160 bpf_buffer_init(struct bpf_d *d)
  161 {
  162 
  163         d->bd_bufsize = bpf_bufsize;
  164 }
  165 
  166 /*
  167  * Allocate or resize buffers.
  168  */
  169 int
  170 bpf_buffer_ioctl_sblen(struct bpf_d *d, u_int *i)
  171 {
  172         u_int size;
  173         caddr_t fbuf, sbuf;
  174 
  175         size = *i;
  176         if (size > bpf_maxbufsize)
  177                 *i = size = bpf_maxbufsize;
  178         else if (size < BPF_MINBUFSIZE)
  179                 *i = size = BPF_MINBUFSIZE;
  180 
  181         /* Allocate buffers immediately */
  182         fbuf = (caddr_t)malloc(size, M_BPF, M_WAITOK);
  183         sbuf = (caddr_t)malloc(size, M_BPF, M_WAITOK);
  184 
  185         BPFD_LOCK(d);
  186         if (d->bd_bif != NULL) {
  187                 /* Interface already attached, unable to change buffers */
  188                 BPFD_UNLOCK(d);
  189                 free(fbuf, M_BPF);
  190                 free(sbuf, M_BPF);
  191                 return (EINVAL);
  192         }
  193 
  194         /* Free old buffers if set */
  195         if (d->bd_fbuf != NULL)
  196                 free(d->bd_fbuf, M_BPF);
  197         if (d->bd_sbuf != NULL)
  198                 free(d->bd_sbuf, M_BPF);
  199 
  200         /* Fill in new data */
  201         d->bd_bufsize = size;
  202         d->bd_fbuf = fbuf;
  203         d->bd_sbuf = sbuf;
  204 
  205         d->bd_hbuf = NULL;
  206         d->bd_slen = 0;
  207         d->bd_hlen = 0;
  208 
  209         BPFD_UNLOCK(d);
  210         return (0);
  211 }
  212 
  213 /*
  214  * Copy buffer storage to user space in read().
  215  */
  216 int
  217 bpf_buffer_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio)
  218 {
  219 
  220         return (uiomove(buf, len, uio));
  221 }

Cache object: 86db55ce515396eef473d959d85387e8


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.