* Copyright (c) 1982, 1986, 1988 Regents of the University of California.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* 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
* @(#)mbuf.h 7.14 (Berkeley) 12/5/90
* 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 *)((int)(x) & ~(MSIZE-1)))
#define mtocl(x) (((u_int)(x) - (u_int)mbutl) >> MCLSHIFT)
#define cltom(x) ((caddr_t)((u_int)mbutl + ((u_int)(x) >> MCLSHIFT)))
/* header at beginning of each mbuf: */
struct mbuf
*mh_next
; /* next buffer in chain */
struct mbuf
*mh_nextpkt
; /* next chain in queue/record */
int 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 */
int len
; /* total packet length */
struct ifnet
*rcvif
; /* rcv interface */
/* description of external storage mapped into mbuf, valid if M_EXT set */
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 */
struct pkthdr MH_pkthdr
; /* M_PKTHDR set */
struct m_ext MH_ext
; /* M_EXT set */
char M_databuf
[MLEN
]; /* !M_PKTHDR, !M_EXT */
#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_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
#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)
#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 */
/* flags to m_get/MGET */
#define M_DONTWAIT M_NOWAIT
* 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
#define MGET(m, how, type) { \
MALLOC((m), struct mbuf *, MSIZE, mbtypes[type], (how)); \
mbstat.m_mtypes[type]++; \
(m)->m_next = (struct mbuf *)NULL; \
(m)->m_nextpkt = (struct mbuf *)NULL; \
(m)->m_data = (m)->m_dat; \
(m) = m_retry((how), (type)); \
#define MGETHDR(m, how, type) { \
MALLOC((m), struct mbuf *, MSIZE, mbtypes[type], (how)); \
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; \
(m) = m_retryhdr((how), (type)); \
* 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
*mcl_next
;
#define MCLALLOC(p, how) \
(void)m_clalloc(1, (how)); \
if ((p) = (caddr_t)mclfree) { \
mclfree = ((union mcluster *)(p))->mcl_next; \
{ MCLALLOC((m)->m_ext.ext_buf, (how)); \
if ((m)->m_ext.ext_buf != NULL) { \
(m)->m_data = (m)->m_ext.ext_buf; \
(m)->m_ext.ext_size = MCLBYTES; \
if (--mclrefcnt[mtocl(p)] == 0) { \
((union mcluster *)(p))->mcl_next = mclfree; \
mclfree = (union mcluster *)(p); \
* MFREE(struct mbuf *m, struct mbuf *n)
* Free a single mbuf and associated external storage.
* Place the successor, if any, in n.
{ 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, \
MCLFREE((m)->m_ext.ext_buf); \
FREE((m), mbtypes[(m)->m_type]); \
{ mbstat.m_mtypes[(m)->m_type]--; \
if ((m)->m_flags & M_EXT) { \
MCLFREE((m)->m_ext.ext_buf); \
FREE((m), mbtypes[(m)->m_type]); \
* 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) \
{ (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.
#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_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) { \
mbstat.m_mtypes[(m)->m_type]--; \
/* 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)
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 */
extern struct mbuf
*mbutl
; /* virtual address of mclusters */
extern char *mclrefcnt
; /* cluster reference counts */
int max_linkhdr
; /* largest link-level header */
int max_protohdr
; /* largest protocol header */
int max_hdr
; /* largest link+protocol header */
int max_datalen
; /* MHLEN - max_hdr */
struct mbuf
*m_get(), *m_gethdr(), *m_getclr(), *m_retry(), *m_retryhdr();
struct mbuf
*m_free(), *m_copym(), *m_pullup(), *m_prepend();
extern int mbtypes
[]; /* XXX */
int mbtypes
[] = { /* XXX */
M_FREE
, /* MT_FREE 0 /* should be on free list */
M_MBUF
, /* MT_DATA 1 /* dynamic (data) allocation */
M_MBUF
, /* MT_HEADER 2 /* packet header */
M_SOCKET
, /* MT_SOCKET 3 /* socket structure */
M_PCB
, /* MT_PCB 4 /* protocol control block */
M_RTABLE
, /* MT_RTABLE 5 /* routing tables */
M_HTABLE
, /* MT_HTABLE 6 /* IMP host tables */
0, /* MT_ATABLE 7 /* address resolution tables */
M_MBUF
, /* MT_SONAME 8 /* socket name */
M_SOOPTS
, /* MT_SOOPTS 10 /* socket options */
M_FTABLE
, /* MT_FTABLE 11 /* fragment reassembly header */
M_MBUF
, /* MT_RIGHTS 12 /* access rights */
M_IFADDR
, /* MT_IFADDR 13 /* interface address */
M_MBUF
, /* MT_CONTROL 14 /* extra-data protocol message */
M_MBUF
, /* MT_OOBDATA 15 /* expedited data */
25, 26, 27, 28, 29, 30, 31, 32 /* datakit ugliness */