sh4/r2d: update pci, usb and kernel management
[qemu/sh4.git] / slirp / mbuf.h
blobf9f2132556c7a55100372f1f1ba8cb7f3154465e
1 /*
2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
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.
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.
33 * @(#)mbuf.h 8.3 (Berkeley) 1/21/94
34 * mbuf.h,v 1.9 1994/11/14 13:54:20 bde Exp
37 #ifndef _MBUF_H_
38 #define _MBUF_H_
40 #define m_freem m_free
43 #define MINCSIZE 4096 /* Amount to increase mbuf if too small */
46 * Macros for type conversion
47 * mtod(m,t) - convert mbuf pointer to data pointer of correct type
48 * dtom(x) - convert data pointer within mbuf to mbuf pointer (XXX)
50 #define mtod(m,t) ((t)(m)->m_data)
51 /* #define dtom(x) ((struct mbuf *)((int)(x) & ~(M_SIZE-1))) */
53 /* XXX About mbufs for slirp:
54 * Only one mbuf is ever used in a chain, for each "cell" of data.
55 * m_nextpkt points to the next packet, if fragmented.
56 * If the data is too large, the M_EXT is used, and a larger block
57 * is alloced. Therefore, m_free[m] must check for M_EXT and if set
58 * free the m_ext. This is inefficient memory-wise, but who cares.
61 /* XXX should union some of these! */
62 /* header at beginning of each mbuf: */
63 struct m_hdr {
64 struct mbuf *mh_next; /* Linked list of mbufs */
65 struct mbuf *mh_prev;
66 struct mbuf *mh_nextpkt; /* Next packet in queue/record */
67 struct mbuf *mh_prevpkt; /* Flags aren't used in the output queue */
68 int mh_flags; /* Misc flags */
70 int mh_size; /* Size of data */
71 struct socket *mh_so;
73 caddr_t mh_data; /* Location of data */
74 int mh_len; /* Amount of data in this mbuf */
78 * How much room is in the mbuf, from m_data to the end of the mbuf
80 #define M_ROOM(m) ((m->m_flags & M_EXT)? \
81 (((m)->m_ext + (m)->m_size) - (m)->m_data) \
82 : \
83 (((m)->m_dat + (m)->m_size) - (m)->m_data))
86 * How much free room there is
88 #define M_FREEROOM(m) (M_ROOM(m) - (m)->m_len)
89 #define M_TRAILINGSPACE M_FREEROOM
91 struct mbuf {
92 struct m_hdr m_hdr;
93 union M_dat {
94 char m_dat_[1]; /* ANSI don't like 0 sized arrays */
95 char *m_ext_;
96 } M_dat;
99 #define m_next m_hdr.mh_next
100 #define m_prev m_hdr.mh_prev
101 #define m_nextpkt m_hdr.mh_nextpkt
102 #define m_prevpkt m_hdr.mh_prevpkt
103 #define m_flags m_hdr.mh_flags
104 #define m_len m_hdr.mh_len
105 #define m_data m_hdr.mh_data
106 #define m_size m_hdr.mh_size
107 #define m_dat M_dat.m_dat_
108 #define m_ext M_dat.m_ext_
109 #define m_so m_hdr.mh_so
111 #define ifq_prev m_prev
112 #define ifq_next m_next
113 #define ifs_prev m_prevpkt
114 #define ifs_next m_nextpkt
115 #define ifq_so m_so
117 #define M_EXT 0x01 /* m_ext points to more (malloced) data */
118 #define M_FREELIST 0x02 /* mbuf is on free list */
119 #define M_USEDLIST 0x04 /* XXX mbuf is on used list (for dtom()) */
120 #define M_DOFREE 0x08 /* when m_free is called on the mbuf, free()
121 * it rather than putting it on the free list */
124 * Mbuf statistics. XXX
127 struct mbstat {
128 int mbs_alloced; /* Number of mbufs allocated */
132 extern struct mbstat mbstat;
133 extern int mbuf_alloced;
134 extern struct mbuf m_freelist, m_usedlist;
135 extern int mbuf_max;
137 void m_init _P((void));
138 struct mbuf * m_get _P((void));
139 void m_free _P((struct mbuf *));
140 void m_cat _P((register struct mbuf *, register struct mbuf *));
141 void m_inc _P((struct mbuf *, int));
142 void m_adj _P((struct mbuf *, int));
143 int m_copy _P((struct mbuf *, struct mbuf *, int, int));
144 struct mbuf * dtom _P((void *));
146 #endif