The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/sys/mbuf.h

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*
    2  * Copyright (c) 1982, 1986, 1988, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  * 3. All advertising materials mentioning features or use of this software
   14  *    must display the following acknowledgement:
   15  *      This product includes software developed by the University of
   16  *      California, Berkeley and its contributors.
   17  * 4. Neither the name of the University nor the names of its contributors
   18  *    may be used to endorse or promote products derived from this software
   19  *    without specific prior written permission.
   20  *
   21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   31  * SUCH DAMAGE.
   32  *
   33  *      @(#)mbuf.h      8.5 (Berkeley) 2/19/95
   34  * $FreeBSD: src/sys/sys/mbuf.h,v 1.18.2.1 1999/09/05 08:22:35 peter Exp $
   35  */
   36 
   37 #ifndef _SYS_MBUF_H_
   38 #define _SYS_MBUF_H_
   39 
   40 #ifndef M_WAITOK
   41 #include <sys/malloc.h>
   42 #endif
   43 
   44 /*
   45  * Mbufs are of a single size, MSIZE (machine/machparam.h), which
   46  * includes overhead.  An mbuf may add a single "mbuf cluster" of size
   47  * MCLBYTES (also in machine/machparam.h), which has no additional overhead
   48  * and is used instead of the internal data area; this is done when
   49  * at least MINCLSIZE of data must be stored.
   50  */
   51 
   52 #define MLEN            (MSIZE - sizeof(struct m_hdr))  /* normal data len */
   53 #define MHLEN           (MLEN - sizeof(struct pkthdr))  /* data len w/pkthdr */
   54 
   55 #define MINCLSIZE       (MHLEN + MLEN)  /* smallest amount to put in cluster */
   56 #define M_MAXCOMPRESS   (MHLEN / 2)     /* max amount to copy for compression */
   57 
   58 /*
   59  * Macros for type conversion
   60  * mtod(m,t) -  convert mbuf pointer to data pointer of correct type
   61  * dtom(x) -    convert data pointer within mbuf to mbuf pointer (XXX)
   62  * mtocl(x) -   convert pointer within cluster to cluster index #
   63  * cltom(x) -   convert cluster # to ptr to beginning of cluster
   64  */
   65 #define mtod(m,t)       ((t)((m)->m_data))
   66 #define dtom(x)         ((struct mbuf *)((long)(x) & ~(MSIZE-1)))
   67 #define mtocl(x)        (((u_long)(x) - (u_long)mbutl) >> MCLSHIFT)
   68 #define cltom(x)        ((caddr_t)((u_long)mbutl + ((u_long)(x) << MCLSHIFT)))
   69 
   70 /* header at beginning of each mbuf: */
   71 struct m_hdr {
   72         struct  mbuf *mh_next;          /* next buffer in chain */
   73         struct  mbuf *mh_nextpkt;       /* next chain in queue/record */
   74         caddr_t mh_data;                /* location of data */
   75         int     mh_len;                 /* amount of data in this mbuf */
   76         short   mh_type;                /* type of data in this mbuf */
   77         short   mh_flags;               /* flags; see below */
   78 };
   79 
   80 /* record/packet header in first mbuf of chain; valid if M_PKTHDR set */
   81 struct  pkthdr {
   82         struct  ifnet *rcvif;           /* rcv interface */
   83         int     len;                    /* total packet length */
   84 };
   85 
   86 /* description of external storage mapped into mbuf, valid if M_EXT set */
   87 struct m_ext {
   88         caddr_t ext_buf;                /* start of buffer */
   89         void    (*ext_free)             /* free routine if not the usual */
   90                 __P((caddr_t, u_int));
   91         u_int   ext_size;               /* size of buffer, for ext_free */
   92         void    (*ext_ref)              /* add a reference to the ext object */
   93                 __P((caddr_t, u_int));
   94 };
   95 
   96 struct mbuf {
   97         struct  m_hdr m_hdr;
   98         union {
   99                 struct {
  100                         struct  pkthdr MH_pkthdr;       /* M_PKTHDR set */
  101                         union {
  102                                 struct  m_ext MH_ext;   /* M_EXT set */
  103                                 char    MH_databuf[MHLEN];
  104                         } MH_dat;
  105                 } MH;
  106                 char    M_databuf[MLEN];                /* !M_PKTHDR, !M_EXT */
  107         } M_dat;
  108 };
  109 #define m_next          m_hdr.mh_next
  110 #define m_len           m_hdr.mh_len
  111 #define m_data          m_hdr.mh_data
  112 #define m_type          m_hdr.mh_type
  113 #define m_flags         m_hdr.mh_flags
  114 #define m_nextpkt       m_hdr.mh_nextpkt
  115 #define m_act           m_nextpkt
  116 #define m_pkthdr        M_dat.MH.MH_pkthdr
  117 #define m_ext           M_dat.MH.MH_dat.MH_ext
  118 #define m_pktdat        M_dat.MH.MH_dat.MH_databuf
  119 #define m_dat           M_dat.M_databuf
  120 
  121 /* mbuf flags */
  122 #define M_EXT           0x0001  /* has associated external storage */
  123 #define M_PKTHDR        0x0002  /* start of record */
  124 #define M_EOR           0x0004  /* end of record */
  125 #define M_PROTO1        0x0008  /* protocol-specific */
  126 
  127 /* mbuf pkthdr flags, also in m_flags */
  128 #define M_BCAST         0x0100  /* send/received as link-level broadcast */
  129 #define M_MCAST         0x0200  /* send/received as link-level multicast */
  130 
  131 /* flags copied when copying m_pkthdr */
  132 #define M_COPYFLAGS     (M_PKTHDR|M_EOR|M_PROTO1|M_BCAST|M_MCAST)
  133 
  134 /* mbuf types */
  135 #define MT_FREE         0       /* should be on free list */
  136 #define MT_DATA         1       /* dynamic (data) allocation */
  137 #define MT_HEADER       2       /* packet header */
  138 #define MT_SOCKET       3       /* socket structure */
  139 #define MT_PCB          4       /* protocol control block */
  140 #define MT_RTABLE       5       /* routing tables */
  141 #define MT_HTABLE       6       /* IMP host tables */
  142 #define MT_ATABLE       7       /* address resolution tables */
  143 #define MT_SONAME       8       /* socket name */
  144 #define MT_SOOPTS       10      /* socket options */
  145 #define MT_FTABLE       11      /* fragment reassembly header */
  146 #define MT_RIGHTS       12      /* access rights */
  147 #define MT_IFADDR       13      /* interface address */
  148 #define MT_CONTROL      14      /* extra-data protocol message */
  149 #define MT_OOBDATA      15      /* expedited data  */
  150 
  151 /* flags to m_get/MGET */
  152 #define M_DONTWAIT      M_NOWAIT
  153 #define M_WAIT          M_WAITOK
  154 
  155 /* Freelists:
  156  *
  157  * Normal mbuf clusters are normally treated as character arrays
  158  * after allocation, but use the first word of the buffer as a free list
  159  * pointer while on the free list.
  160  */
  161 union mcluster {
  162         union   mcluster *mcl_next;
  163         char    mcl_buf[MCLBYTES];
  164 };
  165 
  166 /*
  167  * mbuf utility macros:
  168  *
  169  *      MBUFLOCK(code)
  170  * prevents a section of code from from being interrupted by network
  171  * drivers.
  172  */
  173 #define MBUFLOCK(code) \
  174         { int ms = splimp(); \
  175           { code } \
  176           splx(ms); \
  177         }
  178 
  179 /*
  180  * mbuf allocation/deallocation macros:
  181  *
  182  *      MGET(struct mbuf *m, int how, int type)
  183  * allocates an mbuf and initializes it to contain internal data.
  184  *
  185  *      MGETHDR(struct mbuf *m, int how, int type)
  186  * allocates an mbuf and initializes it to contain a packet header
  187  * and internal data.
  188  */
  189 #define MGET(m, how, type) { \
  190           int _ms = splimp(); \
  191           if (mmbfree == 0) \
  192                 (void)m_mballoc(1, (how)); \
  193           if (((m) = mmbfree) != 0) { \
  194                 mmbfree = (m)->m_next; \
  195                 mbstat.m_mtypes[MT_FREE]--; \
  196                 (m)->m_type = (type); \
  197                 mbstat.m_mtypes[type]++; \
  198                 (m)->m_next = (struct mbuf *)NULL; \
  199                 (m)->m_nextpkt = (struct mbuf *)NULL; \
  200                 (m)->m_data = (m)->m_dat; \
  201                 (m)->m_flags = 0; \
  202                 splx(_ms); \
  203         } else { \
  204                 splx(_ms); \
  205                 (m) = m_retry((how), (type)); \
  206         } \
  207 }
  208 
  209 #define MGETHDR(m, how, type) { \
  210           int _ms = splimp(); \
  211           if (mmbfree == 0) \
  212                 (void)m_mballoc(1, (how)); \
  213           if (((m) = mmbfree) != 0) { \
  214                 mmbfree = (m)->m_next; \
  215                 mbstat.m_mtypes[MT_FREE]--; \
  216                 (m)->m_type = (type); \
  217                 mbstat.m_mtypes[type]++; \
  218                 (m)->m_next = (struct mbuf *)NULL; \
  219                 (m)->m_nextpkt = (struct mbuf *)NULL; \
  220                 (m)->m_data = (m)->m_pktdat; \
  221                 (m)->m_flags = M_PKTHDR; \
  222                 splx(_ms); \
  223         } else { \
  224                 splx(_ms); \
  225                 (m) = m_retryhdr((how), (type)); \
  226         } \
  227 }
  228 
  229 /*
  230  * Mbuf cluster macros.
  231  * MCLALLOC(caddr_t p, int how) allocates an mbuf cluster.
  232  * MCLGET adds such clusters to a normal mbuf;
  233  * the flag M_EXT is set upon success.
  234  * MCLFREE releases a reference to a cluster allocated by MCLALLOC,
  235  * freeing the cluster if the reference count has reached 0.
  236  */
  237 #define MCLALLOC(p, how) \
  238         MBUFLOCK( \
  239           if (mclfree == 0) \
  240                 (void)m_clalloc(1, (how)); \
  241           if (((p) = (caddr_t)mclfree) != 0) { \
  242                 ++mclrefcnt[mtocl(p)]; \
  243                 mbstat.m_clfree--; \
  244                 mclfree = ((union mcluster *)(p))->mcl_next; \
  245           } \
  246         )
  247 
  248 #define MCLGET(m, how) \
  249         { MCLALLOC((m)->m_ext.ext_buf, (how)); \
  250           if ((m)->m_ext.ext_buf != NULL) { \
  251                 (m)->m_data = (m)->m_ext.ext_buf; \
  252                 (m)->m_flags |= M_EXT; \
  253                 (m)->m_ext.ext_free = NULL;  \
  254                 (m)->m_ext.ext_ref = NULL;  \
  255                 (m)->m_ext.ext_size = MCLBYTES;  \
  256           } \
  257         }
  258 
  259 #define MCLFREE(p) \
  260         MBUFLOCK ( \
  261           if (--mclrefcnt[mtocl(p)] == 0) { \
  262                 ((union mcluster *)(p))->mcl_next = mclfree; \
  263                 mclfree = (union mcluster *)(p); \
  264                 mbstat.m_clfree++; \
  265           } \
  266         )
  267 
  268 /*
  269  * MFREE(struct mbuf *m, struct mbuf *n)
  270  * Free a single mbuf and associated external storage.
  271  * Place the successor, if any, in n.
  272  */
  273 #define MFREE(m, n) \
  274         MBUFLOCK(  \
  275           mbstat.m_mtypes[(m)->m_type]--; \
  276           if ((m)->m_flags & M_EXT) { \
  277                 if ((m)->m_ext.ext_free) \
  278                         (*((m)->m_ext.ext_free))((m)->m_ext.ext_buf, \
  279                             (m)->m_ext.ext_size); \
  280                 else { \
  281                         char *p = (m)->m_ext.ext_buf; \
  282                         if (--mclrefcnt[mtocl(p)] == 0) { \
  283                                 ((union mcluster *)(p))->mcl_next = mclfree; \
  284                                 mclfree = (union mcluster *)(p); \
  285                                 mbstat.m_clfree++; \
  286                         } \
  287                 } \
  288           } \
  289           (n) = (m)->m_next; \
  290           (m)->m_type = MT_FREE; \
  291           mbstat.m_mtypes[MT_FREE]++; \
  292           (m)->m_next = mmbfree; \
  293           mmbfree = (m); \
  294         )
  295 
  296 /*
  297  * Copy mbuf pkthdr from from to to.
  298  * from must have M_PKTHDR set, and to must be empty.
  299  */
  300 #define M_COPY_PKTHDR(to, from) { \
  301         (to)->m_pkthdr = (from)->m_pkthdr; \
  302         (to)->m_flags = (from)->m_flags & M_COPYFLAGS; \
  303         (to)->m_data = (to)->m_pktdat; \
  304 }
  305 
  306 /*
  307  * Set the m_data pointer of a newly-allocated mbuf (m_get/MGET) to place
  308  * an object of the specified size at the end of the mbuf, longword aligned.
  309  */
  310 #define M_ALIGN(m, len) \
  311         { (m)->m_data += (MLEN - (len)) &~ (sizeof(long) - 1); }
  312 /*
  313  * As above, for mbufs allocated with m_gethdr/MGETHDR
  314  * or initialized by M_COPY_PKTHDR.
  315  */
  316 #define MH_ALIGN(m, len) \
  317         { (m)->m_data += (MHLEN - (len)) &~ (sizeof(long) - 1); }
  318 
  319 /*
  320  * Compute the amount of space available
  321  * before the current start of data in an mbuf.
  322  */
  323 #define M_LEADINGSPACE(m) \
  324         ((m)->m_flags & M_EXT ? /* (m)->m_data - (m)->m_ext.ext_buf */ 0 : \
  325             (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \
  326             (m)->m_data - (m)->m_dat)
  327 
  328 /*
  329  * Compute the amount of space available
  330  * after the end of data in an mbuf.
  331  */
  332 #define M_TRAILINGSPACE(m) \
  333         ((m)->m_flags & M_EXT ? (m)->m_ext.ext_buf + (m)->m_ext.ext_size - \
  334             ((m)->m_data + (m)->m_len) : \
  335             &(m)->m_dat[MLEN] - ((m)->m_data + (m)->m_len))
  336 
  337 /*
  338  * Arrange to prepend space of size plen to mbuf m.
  339  * If a new mbuf must be allocated, how specifies whether to wait.
  340  * If how is M_DONTWAIT and allocation fails, the original mbuf chain
  341  * is freed and m is set to NULL.
  342  */
  343 #define M_PREPEND(m, plen, how) { \
  344         if (M_LEADINGSPACE(m) >= (plen)) { \
  345                 (m)->m_data -= (plen); \
  346                 (m)->m_len += (plen); \
  347         } else \
  348                 (m) = m_prepend((m), (plen), (how)); \
  349         if ((m) && (m)->m_flags & M_PKTHDR) \
  350                 (m)->m_pkthdr.len += (plen); \
  351 }
  352 
  353 /* change mbuf to new type */
  354 #define MCHTYPE(m, t) { \
  355         MBUFLOCK(mbstat.m_mtypes[(m)->m_type]--; mbstat.m_mtypes[t]++;) \
  356         (m)->m_type = t;\
  357 }
  358 
  359 /* length to m_copy to copy all */
  360 #define M_COPYALL       1000000000
  361 
  362 /* compatibility with 4.3 */
  363 #define  m_copy(m, o, l)        m_copym((m), (o), (l), M_DONTWAIT)
  364 
  365 /*
  366  * Mbuf statistics.
  367  */
  368 struct mbstat {
  369         u_long  m_mbufs;        /* mbufs obtained from page pool */
  370         u_long  m_clusters;     /* clusters obtained from page pool */
  371         u_long  m_spare;        /* spare field */
  372         u_long  m_clfree;       /* free clusters */
  373         u_long  m_drops;        /* times failed to find space */
  374         u_long  m_wait;         /* times waited for space */
  375         u_long  m_drain;        /* times drained protocols for space */
  376         u_short m_mtypes[256];  /* type specific mbuf allocations */
  377 };
  378 
  379 #ifdef  KERNEL
  380 extern struct mbuf *mbutl;              /* virtual address of mclusters */
  381 extern char     *mclrefcnt;             /* cluster reference counts */
  382 extern struct mbstat mbstat;
  383 extern int      nmbclusters;
  384 extern int      nmbufs;
  385 extern struct mbuf *mmbfree;
  386 extern union mcluster *mclfree;
  387 extern int      max_linkhdr;            /* largest link-level header */
  388 extern int      max_protohdr;           /* largest protocol header */
  389 extern int      max_hdr;                /* largest link+protocol header */
  390 extern int      max_datalen;            /* MHLEN - max_hdr */
  391 extern int      mbtypes[];              /* XXX */
  392 
  393 struct  mbuf *m_copym __P((struct mbuf *, int, int, int));
  394 struct  mbuf *m_copypacket __P((struct mbuf *, int));
  395 struct  mbuf *m_devget __P((char *, int, int, struct ifnet *,
  396                             void (*copy)(char *, caddr_t, u_int)));
  397 struct  mbuf *m_free __P((struct mbuf *));
  398 struct  mbuf *m_get __P((int, int));
  399 struct  mbuf *m_getclr __P((int, int));
  400 struct  mbuf *m_gethdr __P((int, int));
  401 struct  mbuf *m_prepend __P((struct mbuf *,int,int));
  402 struct  mbuf *m_pullup __P((struct mbuf *, int));
  403 struct  mbuf *m_retry __P((int, int));
  404 struct  mbuf *m_retryhdr __P((int, int));
  405 struct  mbuf *m_split __P((struct mbuf *,int,int));
  406 void    m_adj __P((struct mbuf *, int));
  407 void    m_cat __P((struct mbuf *,struct mbuf *));
  408 int     m_mballoc __P((int, int));
  409 int     m_clalloc __P((int, int));
  410 void    m_copyback __P((struct mbuf *, int, int, caddr_t));
  411 void    m_copydata __P((struct mbuf *,int,int,caddr_t));
  412 void    m_freem __P((struct mbuf *));
  413 
  414 #ifdef MBTYPES
  415 int mbtypes[] = {                               /* XXX */
  416         M_FREE,         /* MT_FREE      0          should be on free list */
  417         M_MBUF,         /* MT_DATA      1          dynamic (data) allocation */
  418         M_MBUF,         /* MT_HEADER    2          packet header */
  419         M_SOCKET,       /* MT_SOCKET    3          socket structure */
  420         M_PCB,          /* MT_PCB       4          protocol control block */
  421         M_RTABLE,       /* MT_RTABLE    5          routing tables */
  422         M_HTABLE,       /* MT_HTABLE    6          IMP host tables */
  423         0,              /* MT_ATABLE    7          address resolution tables */
  424         M_MBUF,         /* MT_SONAME    8          socket name */
  425         0,              /*              9 */
  426         M_SOOPTS,       /* MT_SOOPTS    10         socket options */
  427         M_FTABLE,       /* MT_FTABLE    11         fragment reassembly header */
  428         M_MBUF,         /* MT_RIGHTS    12         access rights */
  429         M_IFADDR,       /* MT_IFADDR    13         interface address */
  430         M_MBUF,         /* MT_CONTROL   14         extra-data protocol message */
  431         M_MBUF,         /* MT_OOBDATA   15         expedited data  */
  432 #ifdef DATAKIT
  433         25, 26, 27, 28, 29, 30, 31, 32          /* datakit ugliness */
  434 #endif
  435 };
  436 #endif
  437 #endif
  438 
  439 #endif /* !_SYS_MBUF_H_ */

Cache object: 83a9bc7e61726fb9d3640c03bd479e73


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.