pcap-bpf.h

“网络安全技术实践与代码详解”实例代码

/*-
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 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.h       7.1 (Berkeley) 5/7/91
 *
 * @(#) $Header: /tcpdump/master/libpcap/pcap-bpf.h,v 1.34.2.5 2005/05/27 23:33:00 guy Exp $ (LBL)
 */

/*
 * 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.
 *
 * XXX - should this all just be moved to "pcap.h"?
 */

#ifndef BPF_MAJOR_VERSION

#ifdef __cplusplus
extern "C" {
#endif

/* 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. 
 */
#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))

#define BPF_MAXINSNS 512
#define BPF_MAXBUFSIZE 0x8000
#define BPF_MINBUFSIZE 32

/*
 * Structure for "pcap_compile()", "pcap_setfilter()", etc..
 */
struct bpf_program {
	u_int bf_len;
	struct bpf_insn *bf_insns;
};
 
/*
 * Struct return by BIOCVERSION.  This represents the version number of 
 * the filter language described by the instruction encodings below.
 * bpf understands a program iff kernel_major == filter_major &&
 * kernel_minor >= filter_minor, that is, if the value returned by the
 * running kernel has the same major number and a minor number equal
 * equal to or less than the filter being downloaded.  Otherwise, the
 * results are undefined, meaning an error may be returned or packets
 * may be accepted haphazardly.
 * It has nothing to do with the source code version.
 */
struct bpf_version {
	u_short bv_major;
	u_short bv_minor;
};
/* Current version number of filter architecture. */
#define BPF_MAJOR_VERSION 1
#define BPF_MINOR_VERSION 1

/*
 * Data-link level type codes.
 *
 * Do *NOT* add new values to this list without asking
 * "[e-mail]" for a value.  Otherwise, you run the
 * risk of using a value that's already being used for some other purpose,
 * and of having tools that read libpcap-format captures not being able
 * to handle captures with your new DLT_ value, with no hope that they
 * will ever be changed to do so (as that would destroy their ability
 * to read captures using that value for that other purpose).
 */

/*
 * These are the types that are the same on all platforms, and that
 * have been defined by <net/bpf.h> for ages.
 */
#define DLT_NULL	0	/* BSD loopback encapsulation */
#define DLT_EN10MB	1	/* Ethernet (10Mb) */
#define DLT_EN3MB	2	/* Experimental Ethernet (3Mb) */
#define DLT_AX25	3	/* Amateur Radio AX.25 */
#define DLT_PRONET	4	/* Proteon ProNET Token Ring */
#define DLT_CHAOS	5	/* Chaos */
#define DLT_IEEE802	6	/* IEEE 802 Networks */
#define DLT_ARCNET	7	/* ARCNET, with BSD-style header */
#define DLT_SLIP	8	/* Serial Line IP */
#define DLT_PPP		9	/* Point-to-point Protocol */
#define DLT_FDDI	10	/* FDDI */

/*
 * These are types that are different on some platforms, and that
 * have been defined by <net/bpf.h> for ages.  We use #ifdefs to
 * detect the BSDs that define them differently from the traditional
 * libpcap <net/bpf.h>
 *
 * XXX - DLT_ATM_RFC1483 is 13 in BSD/OS, and DLT_RAW is 14 in BSD/OS,
 * but I don't know what the right #define is for BSD/OS.
 */
#define DLT_ATM_RFC1483	11	/* LLC-encapsulated ATM */

#ifdef __OpenBSD__
#define DLT_RAW		14	/* raw IP */
#else
#define DLT_RAW		12	/* raw IP */
#endif

/*
 * Given that the only OS that currently generates BSD/OS SLIP or PPP
 * is, well, BSD/OS, arguably everybody should have chosen its values
 * for DLT_SLIP_BSDOS and DLT_PPP_BSDOS, which are 15 and 16, but they
 * didn't.  So it goes.
 */
#if defined(__NetBSD__) || defined(__FreeBSD__)
#ifndef DLT_SLIP_BSDOS
#define DLT_SLIP_BSDOS	13	/* BSD/OS Serial Line IP */
#define DLT_PPP_BSDOS	14	/* BSD/OS Point-to-point Protocol */
#endif
#else
#define DLT_SLIP_BSDOS	15	/* BSD/OS Serial Line IP */
#define DLT_PPP_BSDOS	16	/* BSD/OS Point-to-point Protocol */
#endif

/*
 * 17 is used for DLT_OLD_PFLOG in OpenBSD;
 *     OBSOLETE: DLT_PFLOG is 117 in OpenBSD now as well. See below.
 * 18 is used for DLT_PFSYNC in OpenBSD; don't use it for anything else.
 */

#define DLT_ATM_CLIP	19	/* Linux Classical-IP over ATM */

/*
 * Apparently Redback uses this for its SmartEdge 400/800.  I hope
 * nobody else decided to use it, too.
 */
#define DLT_REDBACK_SMARTEDGE	32

/*
 * These values are defined by NetBSD; other platforms should refrain from
 * using them for other purposes, so that NetBSD savefiles with link
 * types of 50 or 51 can be read as this type on all platforms.
 */
#define DLT_PPP_SERIAL	50	/* PPP over serial with HDLC encapsulation */
#define DLT_PPP_ETHER	51	/* PPP over Ethernet */

/*
 * The Axent Raptor firewall - now the Symantec Enterprise Firewall - uses
 * a link-layer type of 99 for the tcpdump it supplies.  The link-layer
 * header has 6 bytes of unknown data, something that appears to be an
 * Ethernet type, and 36 bytes that appear to be 0 in at least one capture
 * I've seen.
 */
#define DLT_SYMANTEC_FIREWALL	99

/*
 * Values between 100 and 103 are used in capture file headers as
 * link-layer types corresponding to DLT_ types that differ
 * between platforms; don't use those values for new DLT_ new types.
 */

/*
 * This value was defined by libpcap 0.5; platforms that have defined
 * it with a different value should define it here with that value -
 * a link type of 104 in a save file will be mapped to DLT_C_HDLC,
 * whatever value that happens to be, so programs will correctly
 * handle files with that link type regardless of the value of
 * DLT_C_HDLC.
 *
 * The name DLT_C_HDLC was used by BSD/OS; we use that name for source
 * compatibility with programs written for BSD/OS.
 *
 * libpcap 0.5 defined it as DLT_CHDLC; we define DLT_CHDLC as well,
 * for source compatibility with programs written for libpcap 0.5.
 */
#define DLT_C_HDLC	104	/* Cisco HDLC */
#define DLT_CHDLC	DLT_C_HDLC

#define DLT_IEEE802_11	105	/* IEEE 802.11 wireless */

/*
 * 106 is reserved for Linux Classical IP over ATM; it's like DLT_RAW,
 * except when it isn't.  (I.e., sometimes it's just raw IP, and
 * sometimes it isn't.)  We currently handle it as DLT_LINUX_SLL,
 * so that we don't have to worry about the link-layer header.)
 */

/*
 * Frame Relay; BSD/OS has a DLT_FR with a value of 11, but that collides
 * with other values.
 * DLT_FR and DLT_FRELAY packets start with the Q.922 Frame Relay header
 * (DLCI, etc.).
 */
#define DLT_FRELAY	107

/*
 * OpenBSD DLT_LOOP, for loopback devices; it's like DLT_NULL, except
 * that the AF_ type in the link-layer header is in network byte order.
 *
 * OpenBSD defines it as 12, but that collides with DLT_RAW, so we
 * define it as 108 here.  If OpenBSD picks up this file, it should
 * define DLT_LOOP as 12 in its version, as per the comment above -
 * and should not use 108 as a DLT_ value.
 */
#define DLT_LOOP	108

/*
 * Encapsulated packets for IPsec; DLT_ENC is 13 in OpenBSD, but that's
 * DLT_SLIP_BSDOS in NetBSD, so we don't use 13 for it in OSes other
 * than OpenBSD.
 */
#ifdef __OpenBSD__
#define DLT_ENC		13
#else
#define DLT_ENC		109
#endif

/*
 * Values between 110 and 112 are reserved for use in capture file headers
 * as link-layer types corresponding to DLT_ types that might differ
 * between platforms; don't use those values for new DLT_ types
 * other than the corresponding DLT_ types.
 */

/*
 * This is for Linux cooked sockets.
 */
#define DLT_LINUX_SLL	113

/*
 * Apple LocalTalk hardware.
 */
#define DLT_LTALK	114

/*
 * Acorn Econet.
 */
#define DLT_ECONET	115

/*
 * Reserved for use with OpenBSD ipfilter.
 */
#define DLT_IPFILTER	116

/*
 * OpenBSD DLT_PFLOG; DLT_PFLOG is 17 in OpenBSD, but that's DLT_LANE8023
 * in SuSE 6.3, so we can't use 17 for it in capture-file headers.
 *
 * XXX: is there a conflict with DLT_PFSYNC 18 as well?
 */
#ifdef __OpenBSD__
#define DLT_OLD_PFLOG	17
#define DLT_PFSYNC	18
#endif
#define DLT_PFLOG	117

/*
 * Registered for Cisco-internal use.
 */
#define DLT_CISCO_IOS	118

/*
 * For 802.11 cards using the Prism II chips, with a link-layer
 * header including Prism monitor mode information plus an 802.11
 * header.
 */
#define DLT_PRISM_HEADER	119

/*
 * Reserved for Aironet 802.11 cards, with an Aironet link-layer header
 * (see Doug Ambrisko's FreeBSD patches).
 */
#define DLT_AIRONET_HEADER	120

/*
 * Reserved for Siemens HiPath HDLC.
 */
#define DLT_HHDLC		121

/*
 * This is for RFC 2625 IP-over-Fibre Channel.
 *
 * This is not for use with raw Fibre Channel, where the link-layer
 * header starts with a Fibre Channel frame header; it's for IP-over-FC,
 * where the link-layer header starts with an RFC 2625 Network_Header
 * field.
 */
#define DLT_IP_OVER_FC		122

/*
 * This is for Full Frontal ATM on Solaris with SunATM, with a
 * pseudo-header followed by an AALn PDU.
 *
 * There may be other forms of Full Frontal ATM on other OSes,