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/*
* 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
/*
* 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.
*/
/*
* mbufs allow to have a gap between the start of the allocated buffer (m_ext if
* M_EXT is set, m_dat otherwise) and the in-use data:
*
* |--gapsize----->|---m_len------->
* |----------m_size------------------------------>
* |----M_ROOM-------------------->
* |-M_FREEROOM-->
*
* ^ ^ ^
* m_dat/m_ext m_data end of buffer
*/
/*
* 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)
struct mbuf {
/* XXX should union some of these! */
/* header at beginning of each mbuf: */
struct mbuf *m_next; /* Linked list of mbufs */
struct mbuf *m_prev;
struct mbuf *m_nextpkt; /* Next packet in queue/record */
struct mbuf *m_prevpkt; /* Flags aren't used in the output queue */
int m_flags; /* Misc flags */
int m_size; /* Size of mbuf, from m_dat or m_ext */
struct socket *m_so;
char *m_data; /* Current location of data */
int m_len; /* Amount of data in this mbuf, from m_data */
Slirp *slirp;
bool resolution_requested;
uint64_t expiration_date;
char *m_ext;
/* start of dynamic buffer area, must be last element */
char m_dat[];
};
#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 *);
void m_cleanup(Slirp *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
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