diff --git a/slirp/mbuf.h b/slirp/mbuf.h
new file mode 100644
index 0000000..8cc292b
--- /dev/null
+++ b/slirp/mbuf.h
@@ -0,0 +1,147 @@
+/*
+ * 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. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. 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_
+
+#define m_freem m_free
+
+
+#define MINCSIZE 4096	/* Amount to increase mbuf if too small */
+
+/*
+ * Macros for type conversion
+ * mtod(m,t) -	convert mbuf pointer to data pointer of correct type
+ * dtom(x) -	convert data pointer within mbuf to mbuf pointer (XXX)
+ */
+#define mtod(m,t)	((t)(m)->m_data)
+/* #define	dtom(x)		((struct mbuf *)((int)(x) & ~(M_SIZE-1))) */
+
+/* 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.
+ */
+
+/* XXX should union some of these! */
+/* header at beginning of each mbuf: */
+struct m_hdr {
+	struct	mbuf *mh_next;		/* Linked list of mbufs */
+	struct	mbuf *mh_prev;
+	struct	mbuf *mh_nextpkt;	/* Next packet in queue/record */
+	struct	mbuf *mh_prevpkt; /* Flags aren't used in the output queue */
+	int	mh_flags;	  /* Misc flags */
+
+	int	mh_size;		/* Size of data */
+	struct	socket *mh_so;
+	
+	caddr_t	mh_data;		/* Location of data */
+	int	mh_len;			/* Amount of data in this mbuf */
+};
+
+/* 
+ * 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)
+#define M_TRAILINGSPACE M_FREEROOM
+
+struct mbuf {
+	struct	m_hdr m_hdr;
+	union M_dat {
+		char	m_dat_[1]; /* ANSI don't like 0 sized arrays */
+		char	*m_ext_;
+	} M_dat;
+};
+
+#define m_next		m_hdr.mh_next
+#define m_prev		m_hdr.mh_prev
+#define m_nextpkt	m_hdr.mh_nextpkt
+#define m_prevpkt	m_hdr.mh_prevpkt
+#define m_flags		m_hdr.mh_flags
+#define	m_len		m_hdr.mh_len
+#define	m_data		m_hdr.mh_data
+#define m_size		m_hdr.mh_size
+#define m_dat		M_dat.m_dat_
+#define m_ext		M_dat.m_ext_
+#define m_so		m_hdr.mh_so
+
+#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 */
+
+/*
+ * Mbuf statistics. XXX
+ */
+
+struct mbstat {
+	int mbs_alloced;		/* Number of mbufs allocated */
+	
+};
+
+extern struct	mbstat mbstat;
+extern int mbuf_alloced;
+extern struct mbuf m_freelist, m_usedlist;
+extern int mbuf_max;
+
+void m_init _P((void));
+void msize_init _P((void));
+struct mbuf * m_get _P((void));
+void m_free _P((struct mbuf *));
+void m_cat _P((register struct mbuf *, register struct mbuf *));
+void m_inc _P((struct mbuf *, int));
+void m_adj _P((struct mbuf *, int));
+int m_copy _P((struct mbuf *, struct mbuf *, int, int));
+struct mbuf * dtom _P((void *));
+
+#endif