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[apple/xnu.git] / bsd / sys / mbuf.h

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1998, 1999 Apple Computer, Inc. All Rights Reserved */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/* 
 * Mach Operating System
 * Copyright (c) 1987 Carnegie-Mellon University
 * All rights reserved.  The CMU software License Agreement specifies
 * the terms and conditions for use and redistribution.
 */
/*
 * Copyright (c) 1994 NeXT Computer, Inc. All rights reserved.
 *
 * Copyright (c) 1982, 1986, 1988 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	8.3 (Berkeley) 1/21/94
 **********************************************************************
 * HISTORY
 * 20-May-95  Mac Gillon (mgillon) at NeXT
 *	New version based on 4.4
 *	Purged old history
 */

#ifndef	_SYS_MBUF_H_
#define	_SYS_MBUF_H_

#include <sys/lock.h>

/*
 * Mbufs are of a single size, MSIZE (machine/param.h), which
 * includes overhead.  An mbuf may add a single "mbuf cluster" of size
 * MCLBYTES (also in machine/param.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 + MLEN)	/* smallest amount to put in cluster */
#define	M_MAXCOMPRESS	(MHLEN / 2)	/* max amount to copy for compression */

#define NMBPCL		(sizeof(union mcluster) / sizeof(struct mbuf))


/*
 * 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)
 * mtocl(x) -	convert pointer within cluster to cluster index #
 * cltom(x) -	convert cluster # to ptr to beginning of cluster
 */
#define mtod(m,t)	((t)((m)->m_data))
#define	dtom(x)		((struct mbuf *)((u_long)(x) & ~(MSIZE-1)))
#define	mtocl(x)	((union mcluster *)(x) - (union mcluster *)mbutl)
#define	cltom(x)	((union mcluster *)(mbutl + (x)))

#define MCLREF(p)	(++mclrefcnt[mtocl(p)])
#define MCLUNREF(p)	(--mclrefcnt[mtocl(p)] == 0)

/* 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 */
	long	mh_len;			/* amount of data in this mbuf */
	caddr_t	mh_data;		/* location of data */
	short	mh_type;		/* type of data in this mbuf */
	short	mh_flags;		/* flags; see below */
};

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

	/* variables for ip and tcp reassembly */
	void	*header;		/* pointer to packet header */
        /* variables for hardware checksum */
        int     csum_flags;             /* flags regarding checksum */       
        int     csum_data;              /* data field used by csum routines */
	struct mbuf *aux;		/* extra data buffer; ipsec/others */
	void	*reserved1;		/* for future use */
	void	*reserved2;		/* for future use */
};


/* description of external storage mapped into mbuf, valid if M_EXT set */
struct m_ext {
	caddr_t	ext_buf;		/* start of buffer */
	void	(*ext_free)();		/* free routine if not the usual */
	u_int	ext_size;		/* size of buffer, for ext_free */
	caddr_t	ext_arg;		/* additional ext_free argument */
	struct	ext_refsq {		/* references held */
		struct ext_refsq *forward, *backward;
	} ext_refs;
};

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 */
				char	MH_databuf[MHLEN];
			} MH_dat;
		} MH;
		char	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 */
#define	M_PROTO1	0x0008	/* protocol-specific */

#define	M_MIP6TUNNEL	0x0010	/* MIP6 temporary use */

/* 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 */
#define M_FRAG		0x0400	/* packet is a fragment of a larger packet */
#define M_ANYCAST6	0x0800  /* received as IPv6 anycast */

/* mbuf pkthdr flags, also in m_flags */
#define M_AUTHIPHDR	0x1000	/* data origin authentication for IP header */
#define M_DECRYPTED	0x2000	/* confidentiality */
#define M_LOOP		0x4000	/* for Mbuf statistics */
#define M_AUTHIPDGM	0x8000	/* data origin authentication */

/* flags copied when copying m_pkthdr */
#define	M_COPYFLAGS	(M_PKTHDR|M_EOR|M_BCAST|M_MCAST|M_FRAG|M_ANYCAST6|M_AUTHIPHDR|M_DECRYPTED|M_LOOP|M_AUTHIPDGM)

/* flags indicating hw checksum support and sw checksum requirements [freebsd4.1]*/
#define CSUM_IP                 0x0001          /* will csum IP */
#define CSUM_TCP                0x0002          /* will csum TCP */
#define CSUM_UDP                0x0004          /* will csum UDP */
#define CSUM_IP_FRAGS           0x0008          /* will csum IP fragments */
#define CSUM_FRAGMENT           0x0010          /* will do IP fragmentation */
        
#define CSUM_IP_CHECKED         0x0100          /* did csum IP */
#define CSUM_IP_VALID           0x0200          /*   ... the csum is valid */
#define CSUM_DATA_VALID         0x0400          /* csum_data field is valid */
#define CSUM_PSEUDO_HDR         0x0800          /* csum_data has pseudo hdr */
#define CSUM_TCP_SUM16          0x1000          /* simple TCP Sum16 computation */
 
#define CSUM_DELAY_DATA         (CSUM_TCP | CSUM_UDP)
#define CSUM_DELAY_IP           (CSUM_IP)       /* XXX add ipv6 here too? */


/* mbuf types */
#define	MT_FREE		0	/* should be on free list */
#define	MT_DATA		1	/* dynamic (data) allocation */
#define	MT_HEADER	2	/* packet header */
#define	MT_SOCKET	3	/* socket structure */
#define	MT_PCB		4	/* protocol control block */
#define	MT_RTABLE	5	/* routing tables */
#define	MT_HTABLE	6	/* IMP host tables */
#define	MT_ATABLE	7	/* address resolution tables */
#define	MT_SONAME	8	/* socket name */
#define	MT_SOOPTS	10	/* socket options */
#define	MT_FTABLE	11	/* fragment reassembly header */
#define	MT_RIGHTS	12	/* access rights */
#define	MT_IFADDR	13	/* interface address */
#define MT_CONTROL	14	/* extra-data protocol message */
#define MT_OOBDATA	15	/* expedited data  */
#define MT_MAX		32	/* enough? */

/* flags to m_get/MGET */
/* Need to include malloc.h to get right options for malloc  */
#include	<sys/malloc.h>

#define	M_DONTWAIT	M_NOWAIT
#define	M_WAIT		M_WAITOK

/*
 * mbuf utility macros:
 *
 *	MBUFLOCK(code)
 * prevents a section of code from from being interrupted by network
 * drivers.
 */


extern
decl_simple_lock_data(, mbuf_slock);
#define MBUF_LOCK() usimple_lock(&mbuf_slock);
#define MBUF_UNLOCK() usimple_unlock(&mbuf_slock);
#define MBUF_LOCKINIT() simple_lock_init(&mbuf_slock);


/*
 * mbuf allocation/deallocation macros:
 *
 *	MGET(struct mbuf *m, int how, int type)
 * allocates an mbuf and initializes it to contain internal data.
 *
 *	MGETHDR(struct mbuf *m, int how, int type)
 * allocates an mbuf and initializes it to contain a packet header
 * and internal data.
 */

#if 1
#define MCHECK(m) if ((m)->m_type != MT_FREE) panic("mget MCHECK: m_type=%x m=%x", m->m_type, m)
#else
#define MCHECK(m)
#endif

extern struct mbuf *mfree;				/* mbuf free list */
extern simple_lock_data_t   mbuf_slock;

#define _MINTGET(m, type) { 						\
	MBUF_LOCK();							\
	if (((m) = mfree) != 0) {					\
		MCHECK(m);								\
		++mclrefcnt[mtocl(m)]; 					\
		mbstat.m_mtypes[MT_FREE]--;				\
		mbstat.m_mtypes[type]++;				\
		mfree = (m)->m_next;					\
	}								\
	MBUF_UNLOCK();							\
}
	
#define	MGET(m, how, type) {						\
	_MINTGET(m, type);						\
	if (m) { 							\
		(m)->m_next = (m)->m_nextpkt = 0; 			\
		(m)->m_type = (type); 					\
		(m)->m_data = (m)->m_dat; 				\
		(m)->m_flags = 0; 					\
	} else 								\
		(m) = m_retry((how), (type)); 				\
}

#define	MGETHDR(m, how, type) { 					\
	_MINTGET(m, type);						\
	if (m) { 							\
		(m)->m_next = (m)->m_nextpkt = 0; 			\
		(m)->m_type = (type); 					\
		(m)->m_data = (m)->m_pktdat; 				\
		(m)->m_flags = M_PKTHDR; 				\
		(m)->m_pkthdr.rcvif = NULL; 				\
		(m)->m_pkthdr.header = NULL; 				\
		(m)->m_pkthdr.csum_flags = 0; 				\
		(m)->m_pkthdr.csum_data = 0; 				\
		(m)->m_pkthdr.aux = (struct mbuf *)NULL; 		\
		(m)->m_pkthdr.reserved1 = NULL; 			\
		(m)->m_pkthdr.reserved2 = NULL; 			\
	} else 								\
		(m) = m_retryhdr((how), (type)); 			\
}

/*
 * Mbuf cluster macros.
 * MCLALLOC(caddr_t p, int how) allocates an mbuf cluster.
 * MCLGET adds such clusters to a normal mbuf;
 * the flag M_EXT is set upon success.
 * MCLFREE releases a reference to a cluster allocated by MCLALLOC,
 * freeing the cluster if the reference count has reached 0.
 *
 * Normal mbuf clusters are normally treated as character arrays
 * after allocation, but use the first word of the buffer as a free list
 * pointer while on the free list.
 */
union mcluster {
	union	mcluster *mcl_next;
	char	mcl_buf[MCLBYTES];
};

#define	MCLALLOC(p, how) {							\
	(void)m_clalloc(1, (how)); 						\
	if (((p) = (caddr_t)mclfree)) { 					\
		++mclrefcnt[mtocl(p)]; 						\
		mbstat.m_clfree--; 							\
		mclfree = ((union mcluster *)(p))->mcl_next; 		\
	} 								\
	MBUF_UNLOCK(); 							\
}

#define	MCLGET(m, how) { 						\
	MCLALLOC((m)->m_ext.ext_buf, (how)); 				\
	if ((m)->m_ext.ext_buf) { 					\
		(m)->m_data = (m)->m_ext.ext_buf; 			\
		(m)->m_flags |= M_EXT; 					\
		(m)->m_ext.ext_size = MCLBYTES; 			\
		(m)->m_ext.ext_free = 0; 				\
		(m)->m_ext.ext_refs.forward = (m)->m_ext.ext_refs.backward = \
			&(m)->m_ext.ext_refs; \
	} 								\
}

#define	MCLFREE(p) {							\
	MBUF_LOCK(); 							\
	if (--mclrefcnt[mtocl(p)] == 0) { 				\
		((union mcluster *)(p))->mcl_next = mclfree; 		\
		mclfree = (union mcluster *)(p); 			\
		mbstat.m_clfree++; 					\
	} 								\
	MBUF_UNLOCK(); 							\
}

#define MCLHASREFERENCE(m) \
	((m)->m_ext.ext_refs.forward != &((m)->m_ext.ext_refs))

/*
 * MFREE(struct mbuf *m, struct mbuf *n)
 * Free a single mbuf and associated external storage.
 * Place the successor, if any, in n.
 */

#define	MFREE(m, n) (n) = m_free(m)

/*
 * Copy mbuf pkthdr from from to to.
 * from must have M_PKTHDR set, and to must be empty.
 * aux pointer will be moved to `to'.
 */
#define	M_COPY_PKTHDR(to, from) { \
	(to)->m_pkthdr = (from)->m_pkthdr; \
	(from)->m_pkthdr.aux = (struct mbuf *)NULL; \
	(to)->m_flags = (from)->m_flags & M_COPYFLAGS; \
	(to)->m_data = (to)->m_pktdat; \
}

/*
 * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place
 * an object of the specified size at the end of the mbuf, longword aligned.
 */
#define	M_ALIGN(m, len) 						\
	{ (m)->m_data += (MLEN - (len)) &~ (sizeof(long) - 1); }
/*
 * As above, for mbufs allocated with m_gethdr/MGETHDR
 * or initialized by M_COPY_PKTHDR.
 */
#define	MH_ALIGN(m, len) \
	{ (m)->m_data += (MHLEN - (len)) &~ (sizeof(long) - 1); }

/*
 * Compute the amount of space available
 * before the current start of data in an mbuf.
 * Subroutine - data not available if certain references.
 */
int m_leadingspace(struct mbuf *);
#define	M_LEADINGSPACE(m)	m_leadingspace(m)

/*
 * Compute the amount of space available
 * after the end of data in an mbuf.
 * Subroutine - data not available if certain references.
 */
int m_trailingspace(struct mbuf *);
#define	M_TRAILINGSPACE(m)	m_trailingspace(m)

/*
 * Arrange to prepend space of size plen to mbuf m.
 * If a new mbuf must be allocated, how specifies whether to wait.
 * If how is M_DONTWAIT and allocation fails, the original mbuf chain
 * is freed and m is set to NULL.
 */
#define	M_PREPEND(m, plen, how) { 					\
	if (M_LEADINGSPACE(m) >= (plen)) { 				\
		(m)->m_data -= (plen); 					\
		(m)->m_len += (plen); 					\
	} else 								\
		(m) = m_prepend((m), (plen), (how)); 			\
	if ((m) && (m)->m_flags & M_PKTHDR) 				\
		(m)->m_pkthdr.len += (plen); 				\
}

/* change mbuf to new type */
#define MCHTYPE(m, t) { 						\
	MBUF_LOCK();							\
	mbstat.m_mtypes[(m)->m_type]--;					\
	mbstat.m_mtypes[t]++; 						\
	(m)->m_type = t;						\
	MBUF_UNLOCK();							\
}

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

/* compatiblity with 4.3 */
#define  m_copy(m, o, l)	m_copym((m), (o), (l), M_DONTWAIT)

/*
 * Mbuf statistics.
 */
struct mbstat {
	u_long	m_mbufs;	/* mbufs obtained from page pool */
	u_long	m_clusters;	/* clusters obtained from page pool */
	u_long	m_spare;	/* spare field */
	u_long	m_clfree;	/* free clusters */
	u_long	m_drops;	/* times failed to find space */
	u_long	m_wait;		/* times waited for space */
	u_long	m_drain;	/* times drained protocols for space */
	u_short	m_mtypes[256];	/* type specific mbuf allocations */
	u_long	m_mcfail;	/* times m_copym failed */
	u_long	m_mpfail;	/* times m_pullup failed */
	u_long	m_msize;	/* length of an mbuf */
	u_long	m_mclbytes;	/* length of an mbuf cluster */
	u_long	m_minclsize;	/* min length of data to allocate a cluster */
	u_long	m_mlen;		/* length of data in an mbuf */
	u_long	m_mhlen;	/* length of data in a header mbuf */
};

/*
 * pkthdr.aux type tags.
 */
struct mauxtag {
	int af;
	int type;
};

#ifdef	KERNEL
extern union 	mcluster *mbutl;	/* virtual address of mclusters */
extern union 	mcluster *embutl;	/* ending virtual address of mclusters */
extern short 	*mclrefcnt;		/* cluster reference counts */
extern int 	*mcl_paddr;		/* physical addresses of clusters */
extern struct 	mbstat mbstat;		/* statistics */
extern int 	nmbclusters;		/* number of mapped clusters */
extern union 	mcluster *mclfree;	/* free mapped cluster list */
extern int	max_linkhdr;		/* largest link-level header */
extern int	max_protohdr;		/* largest protocol header */
extern int	max_hdr;		/* largest link+protocol header */
extern int	max_datalen;		/* MHLEN - max_hdr */

struct	mbuf *m_copym __P((struct mbuf *, int, int, int));
struct	mbuf *m_free __P((struct mbuf *));
struct	mbuf *m_get __P((int, int));
struct	mbuf *m_getpacket __P((void));
struct	mbuf *m_getclr __P((int, int));
struct	mbuf *m_gethdr __P((int, int));
struct	mbuf *m_prepend __P((struct mbuf *, int, int));
struct	mbuf *m_pullup __P((struct mbuf *, int));
struct	mbuf *m_retry __P((int, int));
struct	mbuf *m_retryhdr __P((int, int));
void m_adj __P((struct mbuf *, int));
int	 m_clalloc __P((int, int));
void m_freem __P((struct mbuf *));
int m_freem_list __P((struct mbuf *));
struct	mbuf *m_devget __P((char *, int, int, struct ifnet *, void (*)()));
char   *mcl_to_paddr __P((char *));
struct mbuf *m_aux_add __P((struct mbuf *, int, int));
struct mbuf *m_aux_find __P((struct mbuf *, int, int));
void m_aux_delete __P((struct mbuf *, struct mbuf *));
#endif
#endif	/* !_SYS_MBUF_H_ */