sys/net/bpf_jitter.h

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (C) 2002-2003 NetGroup, Politecnico di Torino (Italy)
   5  * Copyright (C) 2005-2009 Jung-uk Kim <jkim@FreeBSD.org>
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  * notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  * notice, this list of conditions and the following disclaimer in the
  16  * documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the Politecnico di Torino nor the names of its
  18  * contributors may be used to endorse or promote products derived from
  19  * this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #ifndef _NET_BPF_JITTER_H_
  35 #define _NET_BPF_JITTER_H_
  36
  37 #ifdef _KERNEL
  38 MALLOC_DECLARE(M_BPFJIT);
  39 #endif
  40
  41 extern int bpf_jitter_enable;
  42
  43 /*
  44  * Prototype of a filtering function created by the jitter.
  45  *
  46  * The syntax and the meaning of the parameters is analogous to the one of
  47  * bpf_filter(). Notice that the filter is not among the parameters because
  48  * it is hardwired in the function.
  49  */
  50 typedef u_int (*bpf_filter_func)(u_char *, u_int, u_int);
  51
  52 /* Structure describing a native filtering program created by the jitter. */
  53 typedef struct bpf_jit_filter {
  54         /* The native filtering binary, in the form of a bpf_filter_func. */
  55         bpf_filter_func func;
  56         size_t          size;
  57 } bpf_jit_filter;
  58
  59 /*
  60  * BPF jitter, builds a machine function from a BPF program.
  61  *
  62  * param fp     The BPF pseudo-assembly filter that will be translated
  63  *              into native code.
  64  * param nins   Number of instructions of the input filter.
  65  * return       The bpf_jit_filter structure containing the native filtering
  66  *              binary.
  67  *
  68  * bpf_jitter allocates the buffers for the new native filter and
  69  * then translates the program pointed by fp calling bpf_jit_compile().
  70  */
  71 bpf_jit_filter  *bpf_jitter(struct bpf_insn *fp, int nins);
  72
  73 /*
  74  * Deletes a filtering function that was previously created by bpf_jitter().
  75  *
  76  * param filter The filter to destroy.
  77  *
  78  * This function frees the variuos buffers (code, memory, etc.) associated
  79  * with a filtering function.
  80  */
  81 void            bpf_destroy_jit_filter(bpf_jit_filter *filter);
  82
  83 /*
  84  * Declarations for machine-dependent functions.
  85  */
  86 struct bpf_insn;
  87
  88 bpf_filter_func bpf_jit_compile(struct bpf_insn *, u_int, size_t *);
  89
  90 #endif  /* _NET_BPF_JITTER_H_ */