/*-
* 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
* $FreeBSD$
*/
#ifndef _SYS_MBUF_H_
#define _SYS_MBUF_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. Additionally, it is possible
* to allocate a separate buffer externally and attach it to the mbuf in
* a way similar to that of mbuf clusters.
*/
#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 */
#ifdef _KERNEL
/*-
* 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 *)((intptr_t)(x) & ~(MSIZE-1)))
#endif /* _KERNEL */
/*
* 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 */
short mh_type; /* type of data in this mbuf */
short mh_flags; /* flags; see below */
};
/*
* Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
*/
struct pkthdr {
struct ifnet *rcvif; /* rcv interface */
int len; /* total packet length */
/* 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 */
};
/*
* 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, void *);
void *ext_args; /* optional argument pointer */
u_int ext_size; /* size of buffer, for ext_free */
u_int *ref_cnt; /* pointer to ref count info */
int ext_type; /* type of external storage */
};
/*
* 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_RDONLY 0x0008 /* associated data is marked read-only */
#define M_PROTO1 0x0010 /* protocol-specific */
#define M_PROTO2 0x0020 /* protocol-specific */
#define M_PROTO3 0x0040 /* protocol-specific */
#define M_PROTO4 0x0080 /* protocol-specific */
#define M_PROTO5 0x0100 /* protocol-specific */
/*
* mbuf pkthdr flags (also stored in m_flags).
*/
#define M_BCAST 0x0200 /* send/received as link-level broadcast */
#define M_MCAST 0x0400 /* send/received as link-level multicast */
#define M_FRAG 0x0800 /* packet is a fragment of a larger packet */
#define M_FIRSTFRAG 0x1000 /* packet is first fragment */
#define M_LASTFRAG 0x2000 /* packet is last fragment */
/*
* External buffer types: identify ext_buf type.
*/
#define EXT_CLUSTER 1 /* mbuf cluster */
#define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */
#define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */
#define EXT_MOD_TYPE 200 /* custom module's ext_buf type */
/*
* Flags copied when copying m_pkthdr.
*/
#define M_COPYFLAGS (M_PKTHDR|M_EOR|M_PROTO1|M_PROTO1|M_PROTO2|M_PROTO3 | \
M_PROTO4|M_PROTO5|M_BCAST|M_MCAST|M_FRAG|M_RDONLY)
/*
* Flags indicating hw checksum support and sw checksum requirements.
*/
#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_DELAY_DATA (CSUM_TCP | CSUM_UDP)
#define CSUM_DELAY_IP (CSUM_IP) /* XXX add ipv6 here too? */
/*
* mbuf types.
*/
#define MT_NOTMBUF 0 /* USED INTERNALLY ONLY! Object is not mbuf */
#define MT_DATA 1 /* dynamic (data) allocation */
#define MT_HEADER 2 /* packet header */
#if 0
#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 */
#endif
#define MT_SONAME 8 /* socket name */
#if 0
#define MT_SOOPTS 10 /* socket options */
#endif
#define MT_FTABLE 11 /* fragment reassembly header */
#if 0
#define MT_RIGHTS 12 /* access rights */
#define MT_IFADDR 13 /* interface address */
#endif
#define MT_CONTROL 14 /* extra-data protocol message */
#define MT_OOBDATA 15 /* expedited data */
#define MT_NTYPES 16 /* number of mbuf types for mbtypes[] */
/*
* Mbuf and cluster allocation statistics PCPU structure.
*/
struct mbpstat {
u_long mb_mbfree;
u_long mb_mbpgs;
u_long mb_clfree;
u_long mb_clpgs;
long mb_mbtypes[MT_NTYPES];
short mb_active;
};
/*
* General mbuf allocator statistics structure.
* XXX: Modifications of these are not protected by any mutex locks nor by
* any atomic() manipulations. As a result, we may occasionally lose
* a count or two. Luckily, not all of these fields are modified at all
* and remain static, and those that are manipulated are only manipulated
* in failure situations, which do not occur (hopefully) very often.
*/
struct mbstat {
u_long m_drops; /* times failed to allocate */
u_long m_wait; /* times succesfully returned from wait */
u_long m_drain; /* times drained protocols for space */
u_long m_mcfail; /* XXX: times m_copym failed */
u_long m_mpfail; /* XXX: 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 */
/* Number of mbtypes (gives # elems in mbpstat's mb_mbtypes[] array: */
short m_numtypes;
};
/*
* Flags specifying how an allocation should be made.
* M_DONTWAIT means "don't block if nothing is available" whereas
* M_TRYWAIT means "block for mbuf_wait ticks at most if nothing is
* available."
*/
#define M_DONTWAIT 1
#define M_TRYWAIT 0
#define M_WAIT M_TRYWAIT /* XXX: Deprecated. */
#ifdef _KERNEL
/*-
* mbuf external reference count management macros.
*
* MEXT_IS_REF(m): true if (m) is not the only mbuf referencing
* the external buffer ext_buf.
*
* MEXT_REM_REF(m): remove reference to m_ext object.
*
* MEXT_ADD_REF(m): add reference to m_ext object already
* referred to by (m).
*/
#define MEXT_IS_REF(m) (*((m)->m_ext.ref_cnt) > 1)
#define MEXT_REM_REF(m) do { \
KASSERT(*((m)->m_ext.ref_cnt) > 0, ("m_ext refcnt < 0")); \
atomic_subtract_int((m)->m_ext.ref_cnt, 1); \
} while(0)
#define MEXT_ADD_REF(m) atomic_add_int((m)->m_ext.ref_cnt, 1)
/*
* mbuf, cluster, and external object allocation macros
* (for compatibility purposes).
*/
#define m_getclr m_get_clrd
#define MGET(m, how, type) (m) = m_get((how), (type))
#define MGETHDR(m, how, type) (m) = m_gethdr((how), (type))
#define MCLGET(m, how) m_clget((m), (how))
#define MEXTADD(m, buf, size, free, args, flags, type) \
m_extadd((m), (caddr_t)(buf), (size), (free), (args), (flags), (type))
/*
* MEXTFREE(m): disassociate (and possibly free) an external object from (m).
*
* If the atomic_cmpset_int() returns 0, then we effectively do nothing
* in terms of "cleaning up" (freeing the ext buf and ref. counter) as
* this means that either there are still references, or another thread
* is taking care of the clean-up.
*/
#define MEXTFREE(m) do { \
struct mbuf *_mb = (m); \
\
MEXT_REM_REF(_mb); \
if (atomic_cmpset_int(_mb->m_ext.ref_cnt, 0, 1)) \
_mext_free(_mb); \
_mb->m_flags &= ~M_EXT; \
} while (0)
/*
* Evaluate TRUE if it's safe to write to the mbuf m's data region (this
* can be both the local data payload, or an external buffer area,
* depending on whether M_EXT is set).
*/
#define M_WRITABLE(m) (!((m)->m_flags & M_RDONLY) && (!((m)->m_flags \
& M_EXT) || !MEXT_IS_REF(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) do { \
struct mbuf *_mfrom = (from); \
struct mbuf *_mto = (to); \
\
_mto->m_data = _mto->m_pktdat; \
_mto->m_flags = _mfrom->m_flags & M_COPYFLAGS; \
_mto->m_pkthdr = _mfrom->m_pkthdr; \
_mfrom->m_pkthdr.aux = NULL; \
} while (0)
/*
* 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_WRITABLE(m) ? (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 the allocation fails, the original mbuf chain is freed and m is
* set to NULL.
*/
#define M_PREPEND(m, plen, how) do { \
struct mbuf **_mmp = &(m); \
struct mbuf *_mm = *_mmp; \
int _mplen = (plen); \
int __mhow = (how); \
\
if (M_LEADINGSPACE(_mm) >= _mplen) { \
_mm->m_data -= _mplen; \
_mm->m_len += _mplen; \
} else \
_mm = m_prepend(_mm, _mplen, __mhow); \
if (_mm != NULL && _mm->m_flags & M_PKTHDR) \
_mm->m_pkthdr.len += _mplen; \
*_mmp = _mm; \
} while (0)
/*
* Change mbuf to new type.
* This is a relatively expensive operation and should be avoided.
*/
#define MCHTYPE(m, t) m_chtype((m), (t))
/* Length to m_copy to copy all. */
#define M_COPYALL 1000000000
/* Compatibility with 4.3 */
#define m_copy(m, o, l) m_copym((m), (o), (l), M_DONTWAIT)
/*
* pkthdr.aux type tags.
*/
struct mauxtag {
int af;
int type;
void *p;
};
extern int max_datalen; /* MHLEN - max_hdr */
extern int max_hdr; /* largest link + protocol header */
extern int max_linkhdr; /* largest link-level header */
extern int max_protohdr; /* largest protocol header */
extern struct mbpstat mb_statpcpu[]; /* Per-CPU allocation stats. */
extern struct mbstat mbstat; /* General mbuf stats/infos. */
extern int nmbclusters; /* Maximum number of clusters */
extern int nmbcnt; /* Scale kmem_map for counter space */
extern int nmbufs; /* Maximum number of mbufs */
extern int nsfbufs; /* Number of sendfile(2) bufs */
void _mext_free(struct mbuf *);
void m_adj(struct mbuf *, int);
struct mbuf *m_aux_add(struct mbuf *, int, int);
struct mbuf *m_aux_add2(struct mbuf *, int, int, void *);
void m_aux_delete(struct mbuf *, struct mbuf *);
struct mbuf *m_aux_find(struct mbuf *, int, int);
struct mbuf *m_aux_find2(struct mbuf *, int, int, void *);
void m_cat(struct mbuf *, struct mbuf *);
void m_chtype(struct mbuf *, short);
void m_clget(struct mbuf *, int);
void m_extadd(struct mbuf *, caddr_t, u_int,
void (*free)(caddr_t, void *), void *, short, int);
void m_copyback(struct mbuf *, int, int, caddr_t);
void m_copydata(const struct mbuf *, int, int, caddr_t);
struct mbuf *m_copym(struct mbuf *, int, int, 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_dup(struct mbuf *, int);
struct mbuf *m_free(struct mbuf *);
void m_freem(struct mbuf *);
struct mbuf *m_get(int, int);
struct mbuf *m_get_clrd(int, int);
struct mbuf *m_gethdr(int, int);
struct mbuf *m_gethdr_clrd(int, int);
struct mbuf *m_getm(struct mbuf *, int, int, int);
struct mbuf *m_prepend(struct mbuf *, int, int);
void m_print(const struct mbuf *m);
struct mbuf *m_pulldown(struct mbuf *, int, int, int *);
struct mbuf *m_pullup(struct mbuf *, int);
struct mbuf *m_split(struct mbuf *, int, int);
#endif /* _KERNEL */
#endif /* !_SYS_MBUF_H_ */
