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Diffstat (limited to 'slirp/src/mbuf.h')
| -rw-r--r-- | slirp/src/mbuf.h | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/slirp/src/mbuf.h b/slirp/src/mbuf.h new file mode 100644 index 0000000000..e2d443418a --- /dev/null +++ b/slirp/src/mbuf.h @@ -0,0 +1,126 @@ +/* + * 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 |