aboutsummaryrefslogtreecommitdiff
path: root/slirp/mbuf.h
blob: 8d7951fb42334868f4dff15ea9b9abb713fe71da (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
/*
 * 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. 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 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
 */
#define mtod(m,t)	((t)(m)->m_data)

/* 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;
	Slirp *slirp;
	bool	arp_requested;
	uint64_t expiration_date;
	/* start of dynamic buffer area, must be last element */
	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 */

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

static inline void ifs_init(struct mbuf *ifm)
{
    ifm->ifs_next = ifm->ifs_prev = ifm;
}

#endif