linux-user: stack_base is now mandatory on all targets
[qemu.git] / slirp / mbuf.h
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. Neither the name of the University nor the names of its contributors
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 MINCSIZE 4096 /* Amount to increase mbuf if too small */
37
38 /*
39 * Macros for type conversion
40 * mtod(m,t) - convert mbuf pointer to data pointer of correct type
41 */
42 #define mtod(m,t) ((t)(m)->m_data)
43
44 /* XXX About mbufs for slirp:
45 * Only one mbuf is ever used in a chain, for each "cell" of data.
46 * m_nextpkt points to the next packet, if fragmented.
47 * If the data is too large, the M_EXT is used, and a larger block
48 * is alloced. Therefore, m_free[m] must check for M_EXT and if set
49 * free the m_ext. This is inefficient memory-wise, but who cares.
50 */
51
52 /* XXX should union some of these! */
53 /* header at beginning of each mbuf: */
54 struct m_hdr {
55 struct mbuf *mh_next; /* Linked list of mbufs */
56 struct mbuf *mh_prev;
57 struct mbuf *mh_nextpkt; /* Next packet in queue/record */
58 struct mbuf *mh_prevpkt; /* Flags aren't used in the output queue */
59 int mh_flags; /* Misc flags */
60
61 int mh_size; /* Size of data */
62 struct socket *mh_so;
63
64 caddr_t mh_data; /* Location of data */
65 int mh_len; /* Amount of data in this mbuf */
66 };
67
68 /*
69 * How much room is in the mbuf, from m_data to the end of the mbuf
70 */
71 #define M_ROOM(m) ((m->m_flags & M_EXT)? \
72 (((m)->m_ext + (m)->m_size) - (m)->m_data) \
73 : \
74 (((m)->m_dat + (m)->m_size) - (m)->m_data))
75
76 /*
77 * How much free room there is
78 */
79 #define M_FREEROOM(m) (M_ROOM(m) - (m)->m_len)
80 #define M_TRAILINGSPACE M_FREEROOM
81
82 struct mbuf {
83 struct m_hdr m_hdr;
84 Slirp *slirp;
85 bool arp_requested;
86 uint64_t expiration_date;
87 /* start of dynamic buffer area, must be last element */
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
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 *);
126
127 #endif