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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. 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 8.3 (Berkeley) 1/21/94
34: * mbuf.h,v 1.9 1994/11/14 13:54:20 bde Exp
35: */
36:
37: #ifndef _MBUF_H_
38: #define _MBUF_H_
39:
40: #define m_freem m_free
41:
42:
43: #define MINCSIZE 4096 /* Amount to increase mbuf if too small */
44:
45: /*
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)
49: */
50: #define mtod(m,t) ((t)(m)->m_data)
51: /* #define dtom(x) ((struct mbuf *)((int)(x) & ~(M_SIZE-1))) */
52:
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.
59: */
60:
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 */
69:
70: int mh_size; /* Size of data */
71: struct socket *mh_so;
72:
73: caddr_t mh_data; /* Location of data */
74: int mh_len; /* Amount of data in this mbuf */
75: };
76:
77: /*
78: * How much room is in the mbuf, from m_data to the end of the mbuf
79: */
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))
84:
85: /*
86: * How much free room there is
87: */
88: #define M_FREEROOM(m) (M_ROOM(m) - (m)->m_len)
89: #define M_TRAILINGSPACE M_FREEROOM
90:
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;
97: };
98:
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
110:
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
116:
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 */
122:
123: /*
124: * Mbuf statistics. XXX
125: */
126:
127: struct mbstat {
128: int mbs_alloced; /* Number of mbufs allocated */
129:
130: };
131:
132: extern struct mbstat mbstat;
133: extern int mbuf_alloced;
134: extern struct mbuf m_freelist, m_usedlist;
135: extern int mbuf_max;
136:
137: void m_init _P((void));
138: void msize_init _P((void));
139: struct mbuf * m_get _P((void));
140: void m_free _P((struct mbuf *));
141: void m_cat _P((register struct mbuf *, register struct mbuf *));
142: void m_inc _P((struct mbuf *, int));
143: void m_adj _P((struct mbuf *, int));
144: int m_copy _P((struct mbuf *, struct mbuf *, int, int));
145: struct mbuf * dtom _P((void *));
146:
147: #endif
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