freebsd-src/contrib/libpcap/pcap/bpf.h
2023-05-05 10:56:10 -03:00

310 lines
9.5 KiB
C

/*-
* Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
* 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.
*
* @(#)bpf.h 7.1 (Berkeley) 5/7/91
*/
/*
* This is libpcap's cut-down version of bpf.h; it includes only
* the stuff needed for the code generator and the userland BPF
* interpreter, and the libpcap APIs for setting filters, etc..
*
* "pcap-bpf.c" will include the native OS version, as it deals with
* the OS's BPF implementation.
*
* At least two programs found by Google Code Search explicitly includes
* <pcap/bpf.h> (even though <pcap.h>/<pcap/pcap.h> includes it for you),
* so moving that stuff to <pcap/pcap.h> would break the build for some
* programs.
*/
/*
* If we've already included <net/bpf.h>, don't re-define this stuff.
* We assume BSD-style multiple-include protection in <net/bpf.h>,
* which is true of all but the oldest versions of FreeBSD and NetBSD,
* or Tru64 UNIX-style multiple-include protection (or, at least,
* Tru64 UNIX 5.x-style; I don't have earlier versions available to check),
* or AIX-style multiple-include protection (or, at least, AIX 5.x-style;
* I don't have earlier versions available to check), or QNX-style
* multiple-include protection (as per GitHub pull request #394).
*
* We trust that they will define structures and macros and types in
* a fashion that's source-compatible and binary-compatible with our
* definitions.
*
* We do not check for BPF_MAJOR_VERSION, as that's defined by
* <linux/filter.h>, which is directly or indirectly included in some
* programs that also include pcap.h, and <linux/filter.h> doesn't
* define stuff we need. We *do* protect against <linux/filter.h>
* defining various macros for BPF code itself; <linux/filter.h> says
*
* Try and keep these values and structures similar to BSD, especially
* the BPF code definitions which need to match so you can share filters
*
* so we trust that it will define them in a fashion that's source-compatible
* and binary-compatible with our definitions.
*
* This also provides our own multiple-include protection.
*/
#if !defined(_NET_BPF_H_) && !defined(_NET_BPF_H_INCLUDED) && !defined(_BPF_H_) && !defined(_H_BPF) && !defined(lib_pcap_bpf_h)
#define lib_pcap_bpf_h
#include <pcap/funcattrs.h>
#if defined(__FreeBSD__)
#include <pcap/dlt.h>
#endif
#ifdef __cplusplus
extern "C" {
#endif
/*
* In the past, we modified pcap/pcap.h to include the system net/bpf.h,
* rather than this file. However, starting around 1.10.2, libpcap requires
* the extern functions defined here to build. Simply reverting that local
* change is not a solution, because some ports with '#include <pcap.h>'
* such as mail/spamd and net/xprobe require the system net/bpf.h to be
* pulled in. To accommodate both requirements, make this header a wrapper
* around the system net/bpf.h, but keep the extern function definitions.
*/
#if defined(__FreeBSD__)
#include <net/bpf.h>
#else
/* BSD style release date */
#define BPF_RELEASE 199606
#ifdef MSDOS /* must be 32-bit */
typedef long bpf_int32;
typedef unsigned long bpf_u_int32;
#else
typedef int bpf_int32;
typedef u_int bpf_u_int32;
#endif
/*
* Alignment macros. BPF_WORDALIGN rounds up to the next
* even multiple of BPF_ALIGNMENT.
*
* Tcpdump's print-pflog.c uses this, so we define it here.
*/
#ifndef __NetBSD__
#define BPF_ALIGNMENT sizeof(bpf_int32)
#else
#define BPF_ALIGNMENT sizeof(long)
#endif
#define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
/*
* Structure for "pcap_compile()", "pcap_setfilter()", etc..
*/
struct bpf_program {
u_int bf_len;
struct bpf_insn *bf_insns;
};
/*
* The instruction encodings.
*
* Please inform tcpdump-workers@lists.tcpdump.org if you use any
* of the reserved values, so that we can note that they're used
* (and perhaps implement it in the reference BPF implementation
* and encourage its implementation elsewhere).
*/
/*
* The upper 8 bits of the opcode aren't used. BSD/OS used 0x8000.
*/
/* instruction classes */
#define BPF_CLASS(code) ((code) & 0x07)
#define BPF_LD 0x00
#define BPF_LDX 0x01
#define BPF_ST 0x02
#define BPF_STX 0x03
#define BPF_ALU 0x04
#define BPF_JMP 0x05
#define BPF_RET 0x06
#define BPF_MISC 0x07
/* ld/ldx fields */
#define BPF_SIZE(code) ((code) & 0x18)
#define BPF_W 0x00
#define BPF_H 0x08
#define BPF_B 0x10
/* 0x18 reserved; used by BSD/OS */
#define BPF_MODE(code) ((code) & 0xe0)
#define BPF_IMM 0x00
#define BPF_ABS 0x20
#define BPF_IND 0x40
#define BPF_MEM 0x60
#define BPF_LEN 0x80
#define BPF_MSH 0xa0
/* 0xc0 reserved; used by BSD/OS */
/* 0xe0 reserved; used by BSD/OS */
/* alu/jmp fields */
#define BPF_OP(code) ((code) & 0xf0)
#define BPF_ADD 0x00
#define BPF_SUB 0x10
#define BPF_MUL 0x20
#define BPF_DIV 0x30
#define BPF_OR 0x40
#define BPF_AND 0x50
#define BPF_LSH 0x60
#define BPF_RSH 0x70
#define BPF_NEG 0x80
#define BPF_MOD 0x90
#define BPF_XOR 0xa0
/* 0xb0 reserved */
/* 0xc0 reserved */
/* 0xd0 reserved */
/* 0xe0 reserved */
/* 0xf0 reserved */
#define BPF_JA 0x00
#define BPF_JEQ 0x10
#define BPF_JGT 0x20
#define BPF_JGE 0x30
#define BPF_JSET 0x40
/* 0x50 reserved; used on BSD/OS */
/* 0x60 reserved */
/* 0x70 reserved */
/* 0x80 reserved */
/* 0x90 reserved */
/* 0xa0 reserved */
/* 0xb0 reserved */
/* 0xc0 reserved */
/* 0xd0 reserved */
/* 0xe0 reserved */
/* 0xf0 reserved */
#define BPF_SRC(code) ((code) & 0x08)
#define BPF_K 0x00
#define BPF_X 0x08
/* ret - BPF_K and BPF_X also apply */
#define BPF_RVAL(code) ((code) & 0x18)
#define BPF_A 0x10
/* 0x18 reserved */
/* misc */
#define BPF_MISCOP(code) ((code) & 0xf8)
#define BPF_TAX 0x00
/* 0x08 reserved */
/* 0x10 reserved */
/* 0x18 reserved */
/* #define BPF_COP 0x20 NetBSD "coprocessor" extensions */
/* 0x28 reserved */
/* 0x30 reserved */
/* 0x38 reserved */
/* #define BPF_COPX 0x40 NetBSD "coprocessor" extensions */
/* also used on BSD/OS */
/* 0x48 reserved */
/* 0x50 reserved */
/* 0x58 reserved */
/* 0x60 reserved */
/* 0x68 reserved */
/* 0x70 reserved */
/* 0x78 reserved */
#define BPF_TXA 0x80
/* 0x88 reserved */
/* 0x90 reserved */
/* 0x98 reserved */
/* 0xa0 reserved */
/* 0xa8 reserved */
/* 0xb0 reserved */
/* 0xb8 reserved */
/* 0xc0 reserved; used on BSD/OS */
/* 0xc8 reserved */
/* 0xd0 reserved */
/* 0xd8 reserved */
/* 0xe0 reserved */
/* 0xe8 reserved */
/* 0xf0 reserved */
/* 0xf8 reserved */
/*
* The instruction data structure.
*/
struct bpf_insn {
u_short code;
u_char jt;
u_char jf;
bpf_u_int32 k;
};
/*
* Macros for insn array initializers.
*
* In case somebody's included <linux/filter.h>, or something else that
* gives the kernel's definitions of BPF statements, get rid of its
* definitions, so we can supply ours instead. If some kernel's
* definitions aren't *binary-compatible* with what BPF has had
* since it first sprung from the brows of Van Jacobson and Steve
* McCanne, that kernel should be fixed.
*/
#ifdef BPF_STMT
#undef BPF_STMT
#endif
#define BPF_STMT(code, k) { (u_short)(code), 0, 0, k }
#ifdef BPF_JUMP
#undef BPF_JUMP
#endif
#define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k }
#endif /* defined(__FreeBSD__) */
PCAP_AVAILABLE_0_4
PCAP_API u_int bpf_filter(const struct bpf_insn *, const u_char *, u_int, u_int);
PCAP_AVAILABLE_0_6
PCAP_API int bpf_validate(const struct bpf_insn *f, int len);
PCAP_AVAILABLE_0_4
PCAP_API char *bpf_image(const struct bpf_insn *, int);
PCAP_AVAILABLE_0_6
PCAP_API void bpf_dump(const struct bpf_program *, int);
#if !defined(__FreeBSD__)
/*
* Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
*/
#define BPF_MEMWORDS 16
#endif
#ifdef __cplusplus
}
#endif
#endif /* !defined(_NET_BPF_H_) && !defined(_BPF_H_) && !defined(_H_BPF) && !defined(lib_pcap_bpf_h) */