sys/net/bpf.h

/*
 * Copyright (c) 1990, 1991, 1993
 *	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	8.1 (Berkeley) 6/10/93
 *	@(#)bpf.h	1.34 (LBL)     6/16/96
 *
 * $FreeBSD: head/sys/net/bpf.h 126263 2004-02-26 03:53:54Z mlaier $
 */

#ifndef _NET_BPF_H_
#define _NET_BPF_H_

/* BSD style release date */
#define	BPF_RELEASE 199606

typedef	int32_t	  bpf_int32;
typedef	u_int32_t bpf_u_int32;

/*
 * Alignment macros.  BPF_WORDALIGN rounds up to the next
 * even multiple of BPF_ALIGNMENT.
 */
#define BPF_ALIGNMENT sizeof(long)
#define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))

#define BPF_MAXINSNS 512
#define BPF_MAXBUFSIZE 0x80000
#define BPF_MINBUFSIZE 32

/*
 *  Structure for BIOCSETF.
 */
struct bpf_program {
	u_int bf_len;
	struct bpf_insn *bf_insns;
};

/*
 * Struct returned by BIOCGSTATS.
 */
struct bpf_stat {
	u_int bs_recv;		/* number of packets received */
	u_int bs_drop;		/* number of packets dropped */
};

/*
 * 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

#define	BIOCGBLEN	_IOR('B',102, u_int)
#define	BIOCSBLEN	_IOWR('B',102, u_int)
#define	BIOCSETF	_IOW('B',103, struct bpf_program)
#define	BIOCFLUSH	_IO('B',104)
#define BIOCPROMISC	_IO('B',105)
#define	BIOCGDLT	_IOR('B',106, u_int)
#define BIOCGETIF	_IOR('B',107, struct ifreq)
#define BIOCSETIF	_IOW('B',108, struct ifreq)
#define BIOCSRTIMEOUT	_IOW('B',109, struct timeval)
#define BIOCGRTIMEOUT	_IOR('B',110, struct timeval)
#define BIOCGSTATS	_IOR('B',111, struct bpf_stat)
#define BIOCIMMEDIATE	_IOW('B',112, u_int)
#define BIOCVERSION	_IOR('B',113, struct bpf_version)
#define BIOCGRSIG	_IOR('B',114, u_int)
#define BIOCSRSIG	_IOW('B',115, u_int)
#define BIOCGHDRCMPLT	_IOR('B',116, u_int)
#define BIOCSHDRCMPLT	_IOW('B',117, u_int)
#define BIOCGSEESENT	_IOR('B',118, u_int)
#define BIOCSSEESENT	_IOW('B',119, u_int)
#define	BIOCSDLT	_IOW('B',120, u_int)
#define	BIOCGDLTLIST	_IOWR('B',121, struct bpf_dltlist)

/*
 * Structure prepended to each packet.
 */
struct bpf_hdr {
	struct timeval	bh_tstamp;	/* time stamp */
	bpf_u_int32	bh_caplen;	/* length of captured portion */
	bpf_u_int32	bh_datalen;	/* original length of packet */
	u_short		bh_hdrlen;	/* length of bpf header (this struct
					   plus alignment padding) */
};
/*
 * Because the structure above is not a multiple of 4 bytes, some compilers
 * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
 * Only the kernel needs to know about it; applications use bh_hdrlen.
 */
#ifdef _KERNEL
#define	SIZEOF_BPF_HDR	(sizeof(struct bpf_hdr) <= 20 ? 18 : \
    sizeof(struct bpf_hdr))
#endif

/*
 * Data-link level type codes.
 */
#define DLT_NULL	0	/* no link-layer 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 */
#define DLT_SLIP	8	/* Serial Line IP */
#define DLT_PPP		9	/* Point-to-point Protocol */
#define DLT_FDDI	10	/* FDDI */
#define DLT_ATM_RFC1483	11	/* LLC/SNAP encapsulated atm */
#define DLT_RAW		12	/* raw IP */

/*
 * These are values from BSD/OS's "bpf.h".
 * These are not the same as the values from the traditional libpcap
 * "bpf.h"; however, these values shouldn't be generated by any
 * OS other than BSD/OS, so the correct values to use here are the
 * BSD/OS values.
 *
 * Platforms that have already assigned these values to other
 * DLT_ codes, however, should give these codes the values
 * from that platform, so that programs that use these codes will
 * continue to compile - even though they won't correctly read
 * files of these types.
 */
#define DLT_SLIP_BSDOS	15	/* BSD/OS Serial Line IP */
#define DLT_PPP_BSDOS	16	/* BSD/OS Point-to-point Protocol */

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

/*
 * 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 */

/*
 * 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 */

/*
 * Values between 106 and 107 are used 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_ new types.
 */

/*
 * 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

/*
 * Values between 109 and 112 are used 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_ new 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

/*
 * Reserved for use in capture-file headers as a link-layer type
 * corresponding to 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.
 */
#define DLT_PFLOG	117
#define DLT_PFSYNC	121

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

/*
 * Reserved 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

/*
 * The instruction encodings.
 */
/* 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
#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

/* 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_JA		0x00
#define		BPF_JEQ		0x10
#define		BPF_JGT		0x20
#define		BPF_JGE		0x30
#define		BPF_JSET	0x40
#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

/* misc */
#define BPF_MISCOP(code) ((code) & 0xf8)
#define		BPF_TAX		0x00
#define		BPF_TXA		0x80

/*
 * 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.
 */
#define BPF_STMT(code, k) { (u_short)(code), 0, 0, k }
#define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k }

/*
 * Structure to retrieve available DLTs for the interface.
 */
struct bpf_dltlist {
	u_int	bfl_len;	/* number of bfd_list array */
	u_int	*bfl_list;	/* array of DLTs */
};

#ifdef _KERNEL
struct bpf_if;
int	 bpf_validate(const struct bpf_insn *, int);
void	 bpf_tap(struct bpf_if *, u_char *, u_int);
void	 bpf_mtap(struct bpf_if *, struct mbuf *);
void	 bpf_mtap2(struct bpf_if *, void *, u_int, struct mbuf *);
void	 bpfattach(struct ifnet *, u_int, u_int);
void	 bpfattach2(struct ifnet *, u_int, u_int, struct bpf_if **);
void	 bpfdetach(struct ifnet *);

void	 bpfilterattach(int);
u_int	 bpf_filter(const struct bpf_insn *, u_char *, u_int, u_int);

#define	BPF_TAP(_ifp,_pkt,_pktlen) do {				\
	if ((_ifp)->if_bpf)					\
		bpf_tap((_ifp)->if_bpf, (_pkt), (_pktlen));	\
} while (0)
#define	BPF_MTAP(_ifp,_m) do {					\
	if ((_ifp)->if_bpf) {					\
		M_ASSERTVALID(_m);				\
		bpf_mtap((_ifp)->if_bpf, (_m));			\
	}							\
} while (0)
#define	BPF_MTAP2(_ifp,_data,_dlen,_m) do {			\
	if ((_ifp)->if_bpf) {					\
		M_ASSERTVALID(_m);				\
		bpf_mtap2((_ifp)->if_bpf,(_data),(_dlen),(_m));	\
	}							\
} while (0)
#endif

/*
 * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
 */
#define BPF_MEMWORDS 16

#endif /* _NET_BPF_H_ */