LXR qemu/slirp/mbuf.h

   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. Neither the name of the University nor the names of its contributors
  14 *    may be used to endorse or promote products derived from this software
  15 *    without specific prior written permission.
  16 *
  17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27 * SUCH DAMAGE.
  28 *
  29 *      @(#)mbuf.h      8.3 (Berkeley) 1/21/94
  30 * mbuf.h,v 1.9 1994/11/14 13:54:20 bde Exp
  31 */
  32
  33#ifndef _MBUF_H_
  34#define _MBUF_H_
  35
  36#define MINCSIZE 4096   /* Amount to increase mbuf if too small */
  37
  38/*
  39 * Macros for type conversion
  40 * mtod(m,t) -  convert mbuf pointer to data pointer of correct type
  41 */
  42#define mtod(m,t)       ((t)(m)->m_data)
  43
  44/* XXX About mbufs for slirp:
  45 * Only one mbuf is ever used in a chain, for each "cell" of data.
  46 * m_nextpkt points to the next packet, if fragmented.
  47 * If the data is too large, the M_EXT is used, and a larger block
  48 * is alloced.  Therefore, m_free[m] must check for M_EXT and if set
  49 * free the m_ext.  This is inefficient memory-wise, but who cares.
  50 */
  51
  52/*
  53 * How much room is in the mbuf, from m_data to the end of the mbuf
  54 */
  55#define M_ROOM(m) ((m->m_flags & M_EXT)? \
  56                        (((m)->m_ext + (m)->m_size) - (m)->m_data) \
  57                   : \
  58                        (((m)->m_dat + (m)->m_size) - (m)->m_data))
  59
  60/*
  61 * How much free room there is
  62 */
  63#define M_FREEROOM(m) (M_ROOM(m) - (m)->m_len)
  64#define M_TRAILINGSPACE M_FREEROOM
  65
  66struct mbuf {
  67        /* XXX should union some of these! */
  68        /* header at beginning of each mbuf: */
  69        struct  mbuf *m_next;           /* Linked list of mbufs */
  70        struct  mbuf *m_prev;
  71        struct  mbuf *m_nextpkt;        /* Next packet in queue/record */
  72        struct  mbuf *m_prevpkt;        /* Flags aren't used in the output queue */
  73        int     m_flags;                /* Misc flags */
  74
  75        int     m_size;                 /* Size of data */
  76        struct  socket *m_so;
  77
  78        caddr_t m_data;                 /* Location of data */
  79        int     m_len;                  /* Amount of data in this mbuf */
  80
  81        Slirp *slirp;
  82        bool    resolution_requested;
  83        uint64_t expiration_date;
  84        char   *m_ext;
  85        /* start of dynamic buffer area, must be last element */
  86        char    m_dat[];
  87};
  88
  89#define ifq_prev m_prev
  90#define ifq_next m_next
  91#define ifs_prev m_prevpkt
  92#define ifs_next m_nextpkt
  93#define ifq_so m_so
  94
  95#define M_EXT                   0x01    /* m_ext points to more (malloced) data */
  96#define M_FREELIST              0x02    /* mbuf is on free list */
  97#define M_USEDLIST              0x04    /* XXX mbuf is on used list (for dtom()) */
  98#define M_DOFREE                0x08    /* when m_free is called on the mbuf, free()
  99                                         * it rather than putting it on the free list */
 100
 101void m_init(Slirp *);
 102void m_cleanup(Slirp *slirp);
 103struct mbuf * m_get(Slirp *);
 104void m_free(struct mbuf *);
 105void m_cat(register struct mbuf *, register struct mbuf *);
 106void m_inc(struct mbuf *, int);
 107void m_adj(struct mbuf *, int);
 108int m_copy(struct mbuf *, struct mbuf *, int, int);
 109struct mbuf * dtom(Slirp *, void *);
 110
 111static inline void ifs_init(struct mbuf *ifm)
 112{
 113    ifm->ifs_next = ifm->ifs_prev = ifm;
 114}
 115
 116#endif
 117