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/* 53 * How much room is in the mbuf, from m_data to the end of the mbuf 54 */ 55#define M_ROOM(m) ((m->m_flags & M_EXT)? \ 56 (((m)->m_ext + (m)->m_size) - (m)->m_data) \ 57 : \ 58 (((m)->m_dat + (m)->m_size) - (m)->m_data)) 59 60/* 61 * How much free room there is 62 */ 63#define M_FREEROOM(m) (M_ROOM(m) - (m)->m_len) 64#define M_TRAILINGSPACE M_FREEROOM 65 66struct mbuf { 67 /* XXX should union some of these! */ 68 /* header at beginning of each mbuf: */ 69 struct mbuf *m_next; /* Linked list of mbufs */ 70 struct mbuf *m_prev; 71 struct mbuf *m_nextpkt; /* Next packet in queue/record */ 72 struct mbuf *m_prevpkt; /* Flags aren't used in the output queue */ 73 int m_flags; /* Misc flags */ 74 75 int m_size; /* Size of data */ 76 struct socket *m_so; 77 78 caddr_t m_data; /* Location of data */ 79 int m_len; /* Amount of data in this mbuf */ 80 81 Slirp *slirp; 82 bool resolution_requested; 83 uint64_t expiration_date; 84 char *m_ext; 85 /* start of dynamic buffer area, must be last element */ 86 char m_dat[]; 87}; 88 89#define ifq_prev m_prev 90#define ifq_next m_next 91#define ifs_prev m_prevpkt 92#define ifs_next m_nextpkt 93#define ifq_so m_so 94 95#define M_EXT 0x01 /* m_ext points to more (malloced) data */ 96#define M_FREELIST 0x02 /* mbuf is on free list */ 97#define M_USEDLIST 0x04 /* XXX mbuf is on used list (for dtom()) */ 98#define M_DOFREE 0x08 /* when m_free is called on the mbuf, free() 99 * it rather than putting it on the free list */ 100 101void m_init(Slirp *); 102void m_cleanup(Slirp *slirp); 103struct mbuf * m_get(Slirp *); 104void m_free(struct mbuf *); 105void m_cat(register struct mbuf *, register struct mbuf *); 106void m_inc(struct mbuf *, int); 107void m_adj(struct mbuf *, int); 108int m_copy(struct mbuf *, struct mbuf *, int, int); 109struct mbuf * dtom(Slirp *, void *); 110 111static inline void ifs_init(struct mbuf *ifm) 112{ 113 ifm->ifs_next = ifm->ifs_prev = ifm; 114} 115 116#endif 117