amiga-roadshow/netinclude/sys/mbuf.h

/*
 * :ts=8
 *
 * 'Roadshow' -- Amiga TCP/IP stack
 * Copyright © 2001-2016 by Olaf Barthel.
 * All Rights Reserved.
 *
 * Amiga specific TCP/IP 'C' header files;
 * Freely Distributable
 */

/*
 * Copyright (c) 1982, 1986, 1988, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * 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.
 *
 *	@(#)mbuf.h	8.5 (Berkeley) 2/19/95
 */

#ifndef _SYS_MBUF_H
#define _SYS_MBUF_H

/****************************************************************************/

#ifndef _SYS_NETINCLUDE_TYPES_H
#include <sys/netinclude_types.h>
#endif /* _SYS_NETINCLUDE_TYPES_H */

#ifndef _NET_IF_H
#include <net/if.h>
#endif /* _NET_IF_H */

/****************************************************************************/

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

/****************************************************************************/

#ifdef __GNUC__
 #ifdef __PPC__
  #pragma pack(2)
 #endif
#elif defined(__VBCC__)
 #pragma amiga-align
#endif

/****************************************************************************/

/*
 * Constants related to network buffer management.
 * MCLBYTES must be no larger than CLBYTES (the software page size), and,
 * on machines that exchange pages of input or output buffers with mbuf
 * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
 * of the hardware page size.
 */
#define	MSIZE		128		/* size of an mbuf */
#define	MCLBYTES	2048		/* large enough for ether MTU */
#define	MCLSHIFT	11
#define	MCLOFSET	(MCLBYTES - 1)

/*
 * Mbufs are of a single size, MSIZE (machine/machparam.h), which
 * includes overhead.  An mbuf may add a single "mbuf cluster" of size
 * MCLBYTES (also in machine/machparam.h), which has no additional overhead
 * and is used instead of the internal data area; this is done when
 * at least MINCLSIZE of data must be stored.
 */

#define	MLEN		(MSIZE - sizeof(struct m_hdr))	/* normal data len */
#define	MHLEN		(MLEN - sizeof(struct pkthdr))	/* data len w/pkthdr */

#define	MINCLSIZE	(MHLEN + 1)	/* smallest amount to put in cluster */
#define	M_MAXCOMPRESS	(MHLEN / 2)	/* max amount to copy for compression */

/*
 * Macros for type conversion
 * mtod(m,t) -	convert mbuf pointer to data pointer of correct type
 * dtom(x) -	convert data pointer within mbuf to mbuf pointer (XXX)
 */
#define	mtod(m,t)	((t)((m)->m_data))
#define	dtom(x)		((struct mbuf *)((__ULONG)(x) & ~(MSIZE-1)))

/* header at beginning of each mbuf: */
struct m_hdr {
	struct	mbuf *mh_next;		/* next buffer in chain */
	struct	mbuf *mh_nextpkt;	/* next chain in queue/record */
	__APTR	mh_data;		/* location of data */
	__LONG	mh_len;			/* amount of data in this mbuf */
	__WORD	mh_type;		/* type of data in this mbuf */
	__WORD	mh_flags;		/* flags; see below */
};

/* record/packet header in first mbuf of chain; valid if M_PKTHDR set */
struct	pkthdr {
	struct	ifnet *rcvif;		/* rcv interface */
	__LONG	len;			/* total packet length */
};

/* description of external storage mapped into mbuf, valid if M_EXT set */
struct m_ext {
	__APTR	ext_buf;		/* start of buffer */
	__APTR	ext_free;		/* free routine if not the usual */
	__ULONG	ext_size;		/* size of buffer, for ext_free */
};

struct mbuf {
	struct	m_hdr m_hdr;
	union {
		struct {
			struct	pkthdr MH_pkthdr;	/* M_PKTHDR set */
			union {
				struct	m_ext MH_ext;	/* M_EXT set */
				__UBYTE	MH_databuf[MHLEN];
			} MH_dat;
		} MH;
		__UBYTE	M_databuf[MLEN];		/* !M_PKTHDR, !M_EXT */
	} M_dat;
};
#define	m_next		m_hdr.mh_next
#define	m_len		m_hdr.mh_len
#define	m_data		m_hdr.mh_data
#define	m_type		m_hdr.mh_type
#define	m_flags		m_hdr.mh_flags
#define	m_nextpkt	m_hdr.mh_nextpkt
#define	m_act		m_nextpkt
#define	m_pkthdr	M_dat.MH.MH_pkthdr
#define	m_ext		M_dat.MH.MH_dat.MH_ext
#define	m_pktdat	M_dat.MH.MH_dat.MH_databuf
#define	m_dat		M_dat.M_databuf

/* mbuf flags */
#define	M_EXT		0x0001	/* has associated external storage */
#define	M_PKTHDR	0x0002	/* start of record */
#define	M_EOR		0x0004	/* end of record */

/* mbuf pkthdr flags, also in m_flags */
#define	M_BCAST		0x0100	/* send/received as link-level broadcast */
#define	M_MCAST		0x0200	/* send/received as link-level multicast */

/* flags copied when copying m_pkthdr */
#define	M_COPYFLAGS	(M_PKTHDR|M_EOR|M_BCAST|M_MCAST)

/* length to m_copy to copy all */
#define	M_COPYALL	1000000000

/*
 * Mbuf statistics.
 */
struct mbstat {
	__ULONG	m_mbufs;	/* mbufs obtained from page pool */
	__ULONG	m_clusters;	/* clusters obtained from page pool */
	__ULONG	m_spare;	/* spare field */
	__ULONG	m_clfree;	/* free clusters */
	__ULONG	m_drops;	/* times failed to find space */
	__ULONG	m_wait;		/* times waited for space */
	__ULONG	m_drain;	/* times drained protocols for space */
};

/****************************************************************************/

#ifdef __GNUC__
 #ifdef __PPC__
  #pragma pack()
 #endif
#elif defined(__VBCC__)
 #pragma default-align
#endif

/****************************************************************************/

#ifdef __cplusplus
}
#endif /* __cplusplus */

/****************************************************************************/

#endif /* _SYS_MBUF_H */