/*
* 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. 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
* $FreeBSD: src/sys/sys/mbuf.h,v 1.169 2005/03/17 19:34:57 jmg Exp $
*/
#ifndef _SYS_MBUF_H_
#define _SYS_MBUF_H_
#ifndef M_WAITOK
#include <sys/malloc.h>
#endif
/*
* 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 + MLEN) /* 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).
* 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 *)((intptr_t)(x) & ~(MSIZE-1)))
#define mtocl(x) (((uintptr_t)(x) - (uintptr_t)mbutl) >> MCLSHIFT)
#define cltom(x) ((caddr_t)((u_long)mbutl + ((u_long)(x) << MCLSHIFT)))
/*
* Header present at the beginning of every mbuf.
*/
struct m_hdr {
struct mbuf *mh_next; /* next buffer in chain */
struct mbuf *mh_nextpkt; /* next chain in queue/record */
caddr_t mh_data; /* location of data */
int mh_len; /* amount of data in this mbuf */
int mh_flags; /* flags; see below */
short mh_type; /* type of data in this mbuf */
};
/*
* Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
*/
struct pkthdr {
struct ifnet *rcvif; /* rcv interface */
int32_t len; /* total packet length */
};
/*
* Description of external storage mapped into mbuf; valid only if M_EXT is set.
*/
struct m_ext {
caddr_t ext_buf; /* start of buffer */
void (*ext_free) /* free routine if not the usual */
(caddr_t, u_int);
u_int ext_size; /* size of buffer, for ext_free */
void (*ext_ref) /* add a reference to the ext object */
(caddr_t, u_int);
};
/*
* The core of the mbuf object along with some shortcut defines for
* practical purposes.
*/
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 */
/*
* mbuf pkthdr flags (also stored 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_PROTO1|M_BCAST|M_MCAST)
/*
* 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 */
/*
* General mbuf allocator statistics structure.
*/
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 */
};
/* flags to m_get/MGET */
#define M_DONTWAIT M_NOWAIT
#define M_WAIT M_WAITOK
/* Freelists:
*
* 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];
};
/*
* mbuf utility macros:
*
* MBUFLOCK(code)
* prevents a section of code from from being interrupted by network
* drivers.
*/
#define MBUFLOCK(code) \
{ int ms = splimp(); \
{ code } \
splx(ms); \
}
/*
* 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.
*/
#define MGET(m, how, type) { \
int _ms = splimp(); \
if (mmbfree == 0) \
(void)m_mballoc(1, (how)); \
if (((m) = mmbfree) != 0) { \
mmbfree = (m)->m_next; \
mbstat.m_mtypes[MT_FREE]--; \
(m)->m_type = (type); \
mbstat.m_mtypes[type]++; \
(m)->m_next = (struct mbuf *)NULL; \
(m)->m_nextpkt = (struct mbuf *)NULL; \
(m)->m_data = (m)->m_dat; \
(m)->m_flags = 0; \
splx(_ms); \
} else { \
splx(_ms); \
(m) = m_retry((how), (type)); \
} \
}
#define MGETHDR(m, how, type) { \
int _ms = splimp(); \
if (mmbfree == 0) \
(void)m_mballoc(1, (how)); \
if (((m) = mmbfree) != 0) { \
mmbfree = (m)->m_next; \
mbstat.m_mtypes[MT_FREE]--; \
(m)->m_type = (type); \
mbstat.m_mtypes[type]++; \
(m)->m_next = (struct mbuf *)NULL; \
(m)->m_nextpkt = (struct mbuf *)NULL; \
(m)->m_data = (m)->m_pktdat; \
(m)->m_flags = M_PKTHDR; \
splx(_ms); \
} else { \
splx(_ms); \
(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.
*/
#define MCLALLOC(p, how) \
MBUFLOCK( \
if (mclfree == 0) \
(void)m_clalloc(1, (how)); \
if (((p) = (caddr_t)mclfree) != 0) { \
++mclrefcnt[mtocl(p)]; \
mbstat.m_clfree--; \
mclfree = ((union mcluster *)(p))->mcl_next; \
} \
)
#define MCLGET(m, how) \
{ MCLALLOC((m)->m_ext.ext_buf, (how)); \
if ((m)->m_ext.ext_buf != NULL) { \
(m)->m_data = (m)->m_ext.ext_buf; \
(m)->m_flags |= M_EXT; \
(m)->m_ext.ext_free = NULL; \
(m)->m_ext.ext_ref = NULL; \
(m)->m_ext.ext_size = MCLBYTES; \
} \
}
#define MCLFREE(p) \
MBUFLOCK ( \
if (--mclrefcnt[mtocl(p)] == 0) { \
((union mcluster *)(p))->mcl_next = mclfree; \
mclfree = (union mcluster *)(p); \
mbstat.m_clfree++; \
} \
)
/*
* 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) \
MBUFLOCK( \
mbstat.m_mtypes[(m)->m_type]--; \
if ((m)->m_flags & M_EXT) { \
if ((m)->m_ext.ext_free) \
(*((m)->m_ext.ext_free))((m)->m_ext.ext_buf, \
(m)->m_ext.ext_size); \
else { \
char *p = (m)->m_ext.ext_buf; \
if (--mclrefcnt[mtocl(p)] == 0) { \
((union mcluster *)(p))->mcl_next = mclfree; \
mclfree = (union mcluster *)(p); \
mbstat.m_clfree++; \
} \
} \
} \
(n) = (m)->m_next; \
(m)->m_type = MT_FREE; \
mbstat.m_mtypes[MT_FREE]++; \
(m)->m_next = mmbfree; \
mmbfree = (m); \
)
/*
* Copy mbuf pkthdr from from to to.
* from must have M_PKTHDR set, and to must be empty.
*/
#define M_COPY_PKTHDR(to, from) { \
(to)->m_pkthdr = (from)->m_pkthdr; \
(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) do { \
(m)->m_data += (MLEN - (len)) & ~(sizeof(long) - 1); \
} while (0)
/*
* As above, for mbufs allocated with m_gethdr/MGETHDR
* or initialized by M_COPY_PKTHDR.
*/
#define MH_ALIGN(m, len) do { \
(m)->m_data += (MHLEN - (len)) & ~(sizeof(long) - 1); \
} while (0)
/*
* Compute the amount of space available
* before the current start of data in an mbuf.
*/
#define M_LEADINGSPACE(m) \
((m)->m_flags & M_EXT ? /* (m)->m_data - (m)->m_ext.ext_buf */ 0 : \
(m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \
(m)->m_data - (m)->m_dat)
/*
* Compute the amount of space available
* after the end of data in an mbuf.
*/
#define M_TRAILINGSPACE(m) \
((m)->m_flags & M_EXT ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size - \
((m)->m_data + (m)->m_len) : \
&(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
/*
* 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.
* This is a relatively expensive operation and should be avoided.
*/
#define MCHTYPE(m, t) { \
MBUFLOCK(mbstat.m_mtypes[(m)->m_type]--; mbstat.m_mtypes[t]++;) \
(m)->m_type = t;\
}
/* Length to m_copy to copy all. */
#define M_COPYALL (uint32_t)1000000000L
/* Compatibility with 4.3. */
#define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT)
#ifdef _KERNEL
extern struct mbuf *mbutl; /* virtual address of mclusters */
extern char *mclrefcnt; /* cluster reference counts */
extern struct mbstat mbstat;
extern uint32_t nmbclusters;
extern uint32_t nmbufs;
extern struct mbuf *mmbfree;
extern union mcluster *mclfree;
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(struct mbuf *, int, uint32_t, int);
struct mbuf *m_copypacket(struct mbuf *, int);
struct mbuf *m_devget(char *, int, int, struct ifnet *,
void (*copy)(char *, caddr_t, u_int));
struct mbuf *m_free(struct mbuf *);
struct mbuf *m_get(int, int);
struct mbuf *m_getclr(int, int);
struct mbuf *m_gethdr(int, int);
struct mbuf *m_prepend(struct mbuf *,int,int);
struct mbuf *m_pullup(struct mbuf *, int);
struct mbuf *m_retry(int, int);
struct mbuf *m_retryhdr(int, int);
struct mbuf *m_split(struct mbuf *,int,int);
void m_adj(struct mbuf *, int);
void m_cat(struct mbuf *,struct mbuf *);
int m_mballoc(int, int);
int m_clalloc(int, int);
int m_copyback(struct mbuf *, int, int, caddr_t);
int m_copydata(const struct mbuf *, int, int, caddr_t);
void m_freem(struct mbuf *);
void m_reclaim(void);
#endif /* _KERNEL */
#endif /* !_SYS_MBUF_H_ */
