1 | /* SPDX-License-Identifier: BSD-3-Clause */ |
2 | /* |
3 | * Copyright (c) 1982, 1986, 1988, 1993 |
4 | * The Regents of the University of California. All rights reserved. |
5 | * |
6 | * Redistribution and use in source and binary forms, with or without |
7 | * modification, are permitted provided that the following conditions |
8 | * are met: |
9 | * 1. Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * 2. Redistributions in binary form must reproduce the above copyright |
12 | * notice, this list of conditions and the following disclaimer in the |
13 | * documentation and/or other materials provided with the distribution. |
14 | * 3. Neither the name of the University nor the names of its contributors |
15 | * may be used to endorse or promote products derived from this software |
16 | * without specific prior written permission. |
17 | * |
18 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
19 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
20 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
21 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
22 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
23 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
24 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
25 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
26 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
27 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
28 | * SUCH DAMAGE. |
29 | * |
30 | * @(#)mbuf.h 8.3 (Berkeley) 1/21/94 |
31 | * mbuf.h,v 1.9 1994/11/14 13:54:20 bde Exp |
32 | */ |
33 | |
34 | #ifndef MBUF_H |
35 | #define MBUF_H |
36 | |
37 | /* |
38 | * Macros for type conversion |
39 | * mtod(m,t) - convert mbuf pointer to data pointer of correct type |
40 | */ |
41 | #define mtod(m, t) ((t)(m)->m_data) |
42 | |
43 | /* XXX About mbufs for slirp: |
44 | * Only one mbuf is ever used in a chain, for each "cell" of data. |
45 | * m_nextpkt points to the next packet, if fragmented. |
46 | * If the data is too large, the M_EXT is used, and a larger block |
47 | * is alloced. Therefore, m_free[m] must check for M_EXT and if set |
48 | * free the m_ext. This is inefficient memory-wise, but who cares. |
49 | */ |
50 | |
51 | /* |
52 | * mbufs allow to have a gap between the start of the allocated buffer (m_ext if |
53 | * M_EXT is set, m_dat otherwise) and the in-use data: |
54 | * |
55 | * |--gapsize----->|---m_len-------> |
56 | * |----------m_size------------------------------> |
57 | * |----M_ROOM--------------------> |
58 | * |-M_FREEROOM--> |
59 | * |
60 | * ^ ^ ^ |
61 | * m_dat/m_ext m_data end of buffer |
62 | */ |
63 | |
64 | /* |
65 | * How much room is in the mbuf, from m_data to the end of the mbuf |
66 | */ |
67 | #define M_ROOM(m) \ |
68 | ((m->m_flags & M_EXT) ? (((m)->m_ext + (m)->m_size) - (m)->m_data) : \ |
69 | (((m)->m_dat + (m)->m_size) - (m)->m_data)) |
70 | |
71 | /* |
72 | * How much free room there is |
73 | */ |
74 | #define M_FREEROOM(m) (M_ROOM(m) - (m)->m_len) |
75 | |
76 | struct mbuf { |
77 | /* XXX should union some of these! */ |
78 | /* header at beginning of each mbuf: */ |
79 | struct mbuf *m_next; /* Linked list of mbufs */ |
80 | struct mbuf *m_prev; |
81 | struct mbuf *m_nextpkt; /* Next packet in queue/record */ |
82 | struct mbuf *m_prevpkt; /* Flags aren't used in the output queue */ |
83 | int m_flags; /* Misc flags */ |
84 | |
85 | int m_size; /* Size of mbuf, from m_dat or m_ext */ |
86 | struct socket *m_so; |
87 | |
88 | char *m_data; /* Current location of data */ |
89 | int m_len; /* Amount of data in this mbuf, from m_data */ |
90 | |
91 | Slirp *slirp; |
92 | bool resolution_requested; |
93 | uint64_t expiration_date; |
94 | char *m_ext; |
95 | /* start of dynamic buffer area, must be last element */ |
96 | char m_dat[]; |
97 | }; |
98 | |
99 | #define ifq_prev m_prev |
100 | #define ifq_next m_next |
101 | #define ifs_prev m_prevpkt |
102 | #define ifs_next m_nextpkt |
103 | #define ifq_so m_so |
104 | |
105 | #define M_EXT 0x01 /* m_ext points to more (malloced) data */ |
106 | #define M_FREELIST 0x02 /* mbuf is on free list */ |
107 | #define M_USEDLIST 0x04 /* XXX mbuf is on used list (for dtom()) */ |
108 | #define M_DOFREE \ |
109 | 0x08 /* when m_free is called on the mbuf, free() \ |
110 | * it rather than putting it on the free list */ |
111 | |
112 | void m_init(Slirp *); |
113 | void m_cleanup(Slirp *slirp); |
114 | struct mbuf *m_get(Slirp *); |
115 | void m_free(struct mbuf *); |
116 | void m_cat(register struct mbuf *, register struct mbuf *); |
117 | void m_inc(struct mbuf *, int); |
118 | void m_adj(struct mbuf *, int); |
119 | int m_copy(struct mbuf *, struct mbuf *, int, int); |
120 | struct mbuf *dtom(Slirp *, void *); |
121 | |
122 | static inline void ifs_init(struct mbuf *ifm) |
123 | { |
124 | ifm->ifs_next = ifm->ifs_prev = ifm; |
125 | } |
126 | |
127 | #endif |
128 | |