src/slirp/mbuf.h

/*
 * Copyright (c) 1982, 1986, 1988, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)mbuf.h      8.3 (Berkeley) 1/21/94
 * mbuf.h,v 1.9 1994/11/14 13:54:20 bde Exp
 */

#ifndef _MBUF_H_
#define _MBUF_H_

#define m_freem m_free


#define MINCSIZE 4096   /* Amount to increase mbuf if too small */

/*
 * Macros for type conversion
 * mtod(m,t) -  convert mbuf pointer to data pointer of correct type
 * dtom(x) -    convert data pointer within mbuf to mbuf pointer (XXX)
 */
#define mtod(m,t)       ((t)(m)->m_data)
/* #define      dtom(x)         ((struct mbuf *)((int)(x) & ~(M_SIZE-1))) */

/* XXX About mbufs for slirp:
 * Only one mbuf is ever used in a chain, for each "cell" of data.
 * m_nextpkt points to the next packet, if fragmented.
 * If the data is too large, the M_EXT is used, and a larger block
 * is alloced.  Therefore, m_free[m] must check for M_EXT and if set
 * free the m_ext.  This is inefficient memory-wise, but who cares.
 */

/* XXX should union some of these! */
/* header at beginning of each mbuf: */
struct m_hdr {
        struct  mbuf *mh_next;          /* Linked list of mbufs */
        struct  mbuf *mh_prev;
        struct  mbuf *mh_nextpkt;       /* Next packet in queue/record */
        struct  mbuf *mh_prevpkt; /* Flags aren't used in the output queue */
        int     mh_flags;         /* Misc flags */

        int     mh_size;                /* Size of data */
        struct  socket *mh_so;
        
        caddr_t mh_data;                /* Location of data */
        int     mh_len;                 /* Amount of data in this mbuf */
};

/* 
 * How much room is in the mbuf, from m_data to the end of the mbuf
 */
#define M_ROOM(m) ((m->m_flags & M_EXT)? \
                        (((m)->m_ext + (m)->m_size) - (m)->m_data) \
                   : \
                        (((m)->m_dat + (m)->m_size) - (m)->m_data))

/*
 * How much free room there is
 */
#define M_FREEROOM(m) (M_ROOM(m) - (m)->m_len)
#define M_TRAILINGSPACE M_FREEROOM

struct mbuf {
        struct  m_hdr m_hdr;
        union M_dat {
                char    m_dat_[1]; /* ANSI don't like 0 sized arrays */
                char    *m_ext_;
        } M_dat;
};

#define m_next          m_hdr.mh_next
#define m_prev          m_hdr.mh_prev
#define m_nextpkt       m_hdr.mh_nextpkt
#define m_prevpkt       m_hdr.mh_prevpkt
#define m_flags         m_hdr.mh_flags
#define m_len           m_hdr.mh_len
#define m_data          m_hdr.mh_data
#define m_size          m_hdr.mh_size
#define m_dat           M_dat.m_dat_
#define m_ext           M_dat.m_ext_
#define m_so            m_hdr.mh_so

#define ifq_prev m_prev
#define ifq_next m_next
#define ifs_prev m_prevpkt
#define ifs_next m_nextpkt
#define ifq_so m_so

#define M_EXT                   0x01    /* m_ext points to more (malloced) data */
#define M_FREELIST              0x02    /* mbuf is on free list */
#define M_USEDLIST              0x04    /* XXX mbuf is on used list (for dtom()) */
#define M_DOFREE                0x08    /* when m_free is called on the mbuf, free()
                                         * it rather than putting it on the free list */

/*
 * Mbuf statistics. XXX
 */

struct mbstat {
        int mbs_alloced;                /* Number of mbufs allocated */
        
};

extern struct   mbstat mbstat;
extern int mbuf_alloced;
extern struct mbuf m_freelist, m_usedlist;
extern int mbuf_max;

void m_init _P((void));
void msize_init _P((void));
struct mbuf * m_get _P((void));
void m_free _P((struct mbuf *));
void m_cat _P((register struct mbuf *, register struct mbuf *));
void m_inc _P((struct mbuf *, int));
void m_adj _P((struct mbuf *, int));
int m_copy _P((struct mbuf *, struct mbuf *, int, int));
struct mbuf * dtom _P((void *));

#endif
Revision:	1.1
Committed:	2005-05-13T09:00:59Z (19 years, 6 months ago) by gbeauche
Content type:	text/plain
Branch:	MAIN
CVS Tags:	nigel-build-19, nigel-build-17
Log Message:	slirp user mode network emulation code from qemu
#	User	Rev	Content
1	gbeauche	1.1	/*
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