Annotation of qemu/slirp/mbuf.h, revision 1.1.1.4

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.
1.1.1.3   root       13:  * 3. Neither the name of the University nor the names of its contributors
1.1       root       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:  */
                     45: #define mtod(m,t)      ((t)(m)->m_data)
                     46: 
                     47: /* XXX About mbufs for slirp:
                     48:  * Only one mbuf is ever used in a chain, for each "cell" of data.
                     49:  * m_nextpkt points to the next packet, if fragmented.
                     50:  * If the data is too large, the M_EXT is used, and a larger block
                     51:  * is alloced.  Therefore, m_free[m] must check for M_EXT and if set
                     52:  * free the m_ext.  This is inefficient memory-wise, but who cares.
                     53:  */
                     54: 
                     55: /* XXX should union some of these! */
                     56: /* header at beginning of each mbuf: */
                     57: struct m_hdr {
                     58:        struct  mbuf *mh_next;          /* Linked list of mbufs */
                     59:        struct  mbuf *mh_prev;
                     60:        struct  mbuf *mh_nextpkt;       /* Next packet in queue/record */
                     61:        struct  mbuf *mh_prevpkt; /* Flags aren't used in the output queue */
                     62:        int     mh_flags;         /* Misc flags */
                     63: 
                     64:        int     mh_size;                /* Size of data */
                     65:        struct  socket *mh_so;
1.1.1.2   root       66: 
1.1       root       67:        caddr_t mh_data;                /* Location of data */
                     68:        int     mh_len;                 /* Amount of data in this mbuf */
                     69: };
                     70: 
1.1.1.2   root       71: /*
1.1       root       72:  * How much room is in the mbuf, from m_data to the end of the mbuf
                     73:  */
                     74: #define M_ROOM(m) ((m->m_flags & M_EXT)? \
                     75:                        (((m)->m_ext + (m)->m_size) - (m)->m_data) \
                     76:                   : \
                     77:                        (((m)->m_dat + (m)->m_size) - (m)->m_data))
                     78: 
                     79: /*
                     80:  * How much free room there is
                     81:  */
                     82: #define M_FREEROOM(m) (M_ROOM(m) - (m)->m_len)
                     83: #define M_TRAILINGSPACE M_FREEROOM
                     84: 
                     85: struct mbuf {
                     86:        struct  m_hdr m_hdr;
1.1.1.4 ! root       87:        Slirp *slirp;
1.1       root       88:        union M_dat {
                     89:                char    m_dat_[1]; /* ANSI don't like 0 sized arrays */
                     90:                char    *m_ext_;
                     91:        } M_dat;
                     92: };
                     93: 
                     94: #define m_next         m_hdr.mh_next
                     95: #define m_prev         m_hdr.mh_prev
                     96: #define m_nextpkt      m_hdr.mh_nextpkt
                     97: #define m_prevpkt      m_hdr.mh_prevpkt
                     98: #define m_flags                m_hdr.mh_flags
                     99: #define        m_len           m_hdr.mh_len
                    100: #define        m_data          m_hdr.mh_data
                    101: #define m_size         m_hdr.mh_size
                    102: #define m_dat          M_dat.m_dat_
                    103: #define m_ext          M_dat.m_ext_
                    104: #define m_so           m_hdr.mh_so
                    105: 
                    106: #define ifq_prev m_prev
                    107: #define ifq_next m_next
                    108: #define ifs_prev m_prevpkt
                    109: #define ifs_next m_nextpkt
                    110: #define ifq_so m_so
                    111: 
                    112: #define M_EXT                  0x01    /* m_ext points to more (malloced) data */
                    113: #define M_FREELIST             0x02    /* mbuf is on free list */
                    114: #define M_USEDLIST             0x04    /* XXX mbuf is on used list (for dtom()) */
                    115: #define M_DOFREE               0x08    /* when m_free is called on the mbuf, free()
                    116:                                         * it rather than putting it on the free list */
                    117: 
1.1.1.4 ! root      118: void m_init(Slirp *);
        !           119: struct mbuf * m_get(Slirp *);
        !           120: void m_free(struct mbuf *);
        !           121: void m_cat(register struct mbuf *, register struct mbuf *);
        !           122: void m_inc(struct mbuf *, int);
        !           123: void m_adj(struct mbuf *, int);
        !           124: int m_copy(struct mbuf *, struct mbuf *, int, int);
        !           125: struct mbuf * dtom(Slirp *, void *);
1.1       root      126: 
                    127: #endif

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