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Annotation of previous_trunk/src/slirp/mbuf.h, revision 1.1

1.1     ! root        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 m_freem m_free
        !            37: 
        !            38: 
        !            39: #define MINCSIZE 4096  /* Amount to increase mbuf if too small */
        !            40: 
        !            41: /*
        !            42:  * Macros for type conversion
        !            43:  * mtod(m,t) - convert mbuf pointer to data pointer of correct type
        !            44:  * dtom(x) -   convert data pointer within mbuf to mbuf pointer (XXX)
        !            45:  */
        !            46: #define mtod(m,t)      ((t)(m)->m_data)
        !            47: /* #define     dtom(x)         ((struct mbuf *)((int)(x) & ~(M_SIZE-1))) */
        !            48: 
        !            49: /* XXX About mbufs for slirp:
        !            50:  * Only one mbuf is ever used in a chain, for each "cell" of data.
        !            51:  * m_nextpkt points to the next packet, if fragmented.
        !            52:  * If the data is too large, the M_EXT is used, and a larger block
        !            53:  * is alloced.  Therefore, m_free[m] must check for M_EXT and if set
        !            54:  * free the m_ext.  This is inefficient memory-wise, but who cares.
        !            55:  */
        !            56: 
        !            57: /* XXX should union some of these! */
        !            58: /* header at beginning of each mbuf: */
        !            59: struct m_hdr {
        !            60:        struct  mbuf *mh_next;          /* Linked list of mbufs */
        !            61:        struct  mbuf *mh_prev;
        !            62:        struct  mbuf *mh_nextpkt;       /* Next packet in queue/record */
        !            63:        struct  mbuf *mh_prevpkt; /* Flags aren't used in the output queue */
        !            64:        int     mh_flags;         /* Misc flags */
        !            65: 
        !            66:        size_t  mh_size;                /* Size of data */
        !            67:        struct  socket *mh_so;
        !            68:        
        !            69:        caddr_t mh_data;                /* Location of data */
        !            70:        size_t  mh_len;                 /* Amount of data in this mbuf */
        !            71: };
        !            72: 
        !            73: /* 
        !            74:  * How much room is in the mbuf, from m_data to the end of the mbuf
        !            75:  */
        !            76: #define M_ROOM(m) ((m->m_flags & M_EXT)? \
        !            77:                        (((m)->m_ext + (m)->m_size) - (m)->m_data) \
        !            78:                   : \
        !            79:                        (((m)->m_dat + (m)->m_size) - (m)->m_data))
        !            80: 
        !            81: /*
        !            82:  * How much free room there is
        !            83:  */
        !            84: #define M_FREEROOM(m) (M_ROOM(m) - (m)->m_len)
        !            85: #define M_TRAILINGSPACE M_FREEROOM
        !            86: 
        !            87: struct mbuf {
        !            88:        struct  m_hdr m_hdr;
        !            89:        union M_dat {
        !            90:                char    m_dat_[1]; /* ANSI don't like 0 sized arrays */
        !            91:                char    *m_ext_;
        !            92:        } M_dat;
        !            93: };
        !            94: 
        !            95: #define m_next         m_hdr.mh_next
        !            96: #define m_prev         m_hdr.mh_prev
        !            97: #define m_nextpkt      m_hdr.mh_nextpkt
        !            98: #define m_prevpkt      m_hdr.mh_prevpkt
        !            99: #define m_flags                m_hdr.mh_flags
        !           100: #define        m_len           m_hdr.mh_len
        !           101: #define        m_data          m_hdr.mh_data
        !           102: #define m_size         m_hdr.mh_size
        !           103: #define m_dat          M_dat.m_dat_
        !           104: #define m_ext          M_dat.m_ext_
        !           105: #define m_so           m_hdr.mh_so
        !           106: 
        !           107: #define ifq_prev m_prev
        !           108: #define ifq_next m_next
        !           109: #define ifs_prev m_prevpkt
        !           110: #define ifs_next m_nextpkt
        !           111: #define ifq_so m_so
        !           112: 
        !           113: #define M_EXT                  0x01    /* m_ext points to more (malloced) data */
        !           114: #define M_FREELIST             0x02    /* mbuf is on free list */
        !           115: #define M_USEDLIST             0x04    /* XXX mbuf is on used list (for dtom()) */
        !           116: #define M_DOFREE               0x08    /* when m_free is called on the mbuf, free()
        !           117:                                         * it rather than putting it on the free list */
        !           118: 
        !           119: /*
        !           120:  * Mbuf statistics. XXX
        !           121:  */
        !           122: 
        !           123: struct mbstat {
        !           124:        int mbs_alloced;                /* Number of mbufs allocated */
        !           125:        
        !           126: };
        !           127: 
        !           128: extern struct  mbstat mbstat;
        !           129: extern int mbuf_alloced;
        !           130: extern struct mbuf m_freelist, m_usedlist;
        !           131: extern int mbuf_max;
        !           132: 
        !           133: void m_init(void);
        !           134: void msize_init(void);
        !           135: struct mbuf * m_get(void);
        !           136: void m_free(struct mbuf *);
        !           137: void m_cat(register struct mbuf *, register struct mbuf *);
        !           138: void m_inc(struct mbuf *, u_int);
        !           139: void m_adj(struct mbuf *, int);
        !           140: int m_copy(struct mbuf *, struct mbuf *, u_int, u_int);
        !           141: struct mbuf * dtom(void *);
        !           142: 
        !           143: #endif

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