| David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 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 m_freem m_free |
| 37 | |
| 38 | |
| 39 | #define MINCSIZE 4096 /* Amount to increase mbuf if too small */ |
| 40 | |
| 41 | /* |
| 42 | * Macros for type conversion |
| 43 | * mtod(m,t) - convert mbuf pointer to data pointer of correct type |
| 44 | * dtom(x) - convert data pointer within mbuf to mbuf pointer (XXX) |
| 45 | */ |
| 46 | #define mtod(m,t) ((t)(m)->m_data) |
| 47 | /* #define dtom(x) ((struct mbuf *)((int)(x) & ~(M_SIZE-1))) */ |
| 48 | |
| 49 | /* XXX About mbufs for slirp: |
| 50 | * Only one mbuf is ever used in a chain, for each "cell" of data. |
| 51 | * m_nextpkt points to the next packet, if fragmented. |
| 52 | * If the data is too large, the M_EXT is used, and a larger block |
| 53 | * is alloced. Therefore, m_free[m] must check for M_EXT and if set |
| 54 | * free the m_ext. This is inefficient memory-wise, but who cares. |
| 55 | */ |
| 56 | |
| 57 | /* XXX should union some of these! */ |
| 58 | /* header at beginning of each mbuf: */ |
| 59 | struct m_hdr { |
| 60 | struct mbuf *mh_next; /* Linked list of mbufs */ |
| 61 | struct mbuf *mh_prev; |
| 62 | struct mbuf *mh_nextpkt; /* Next packet in queue/record */ |
| 63 | struct mbuf *mh_prevpkt; /* Flags aren't used in the output queue */ |
| 64 | int mh_flags; /* Misc flags */ |
| 65 | |
| 66 | int mh_size; /* Size of data */ |
| 67 | struct socket *mh_so; |
| 68 | |
| 69 | caddr_t mh_data; /* Location of data */ |
| 70 | int mh_len; /* Amount of data in this mbuf */ |
| 71 | }; |
| 72 | |
| 73 | /* |
| 74 | * How much room is in the mbuf, from m_data to the end of the mbuf |
| 75 | */ |
| 76 | #define M_ROOM(m) ((m->m_flags & M_EXT)? \ |
| 77 | (((m)->m_ext + (m)->m_size) - (m)->m_data) \ |
| 78 | : \ |
| 79 | (((m)->m_dat + (m)->m_size) - (m)->m_data)) |
| 80 | |
| 81 | /* |
| 82 | * How much free room there is |
| 83 | */ |
| 84 | #define M_FREEROOM(m) (M_ROOM(m) - (m)->m_len) |
| 85 | #define M_TRAILINGSPACE M_FREEROOM |
| 86 | |
| 87 | struct mbuf { |
| 88 | struct m_hdr m_hdr; |
| 89 | union M_dat { |
| 90 | char m_dat_[1]; /* ANSI don't like 0 sized arrays */ |
| 91 | char *m_ext_; |
| 92 | } M_dat; |
| 93 | }; |
| 94 | |
| 95 | #define m_next m_hdr.mh_next |
| 96 | #define m_prev m_hdr.mh_prev |
| 97 | #define m_nextpkt m_hdr.mh_nextpkt |
| 98 | #define m_prevpkt m_hdr.mh_prevpkt |
| 99 | #define m_flags m_hdr.mh_flags |
| 100 | #define m_len m_hdr.mh_len |
| 101 | #define m_data m_hdr.mh_data |
| 102 | #define m_size m_hdr.mh_size |
| 103 | #define m_dat M_dat.m_dat_ |
| 104 | #define m_ext M_dat.m_ext_ |
| 105 | #define m_so m_hdr.mh_so |
| 106 | |
| 107 | #define ifq_prev m_prev |
| 108 | #define ifq_next m_next |
| 109 | #define ifs_prev m_prevpkt |
| 110 | #define ifs_next m_nextpkt |
| 111 | #define ifq_so m_so |
| 112 | |
| 113 | #define M_EXT 0x01 /* m_ext points to more (malloced) data */ |
| 114 | #define M_FREELIST 0x02 /* mbuf is on free list */ |
| 115 | #define M_USEDLIST 0x04 /* XXX mbuf is on used list (for dtom()) */ |
| 116 | #define M_DOFREE 0x08 /* when m_free is called on the mbuf, free() |
| 117 | * it rather than putting it on the free list */ |
| 118 | |
| 119 | /* |
| 120 | * Mbuf statistics. XXX |
| 121 | */ |
| 122 | |
| 123 | struct mbstat { |
| 124 | int mbs_alloced; /* Number of mbufs allocated */ |
| 125 | |
| 126 | }; |
| 127 | |
| 128 | extern struct mbstat mbstat; |
| 129 | extern int mbuf_alloced; |
| 130 | extern struct mbuf m_freelist, m_usedlist; |
| 131 | extern int mbuf_max; |
| 132 | |
| 133 | void m_init _P((void)); |
| 134 | struct mbuf * m_get _P((void)); |
| 135 | void m_free _P((struct mbuf *)); |
| 136 | void m_cat _P((register struct mbuf *, register struct mbuf *)); |
| 137 | void m_inc _P((struct mbuf *, int)); |
| 138 | void m_adj _P((struct mbuf *, int)); |
| 139 | int m_copy _P((struct mbuf *, struct mbuf *, int, int)); |
| 140 | struct mbuf * dtom _P((void *)); |
| 141 | |
| 142 | #endif |