/*
 * Copyright (c) 1991-1997 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 Network Research
 *      Group at Lawrence Berkeley Laboratory.
 * 4. Neither the name of the University nor of the Laboratory 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.
 */
/*
 * class queue definitions extracted from altq_classq.h.
 */

#ifndef _NET_IF_CLASSQ_H_
#define _NET_IF_CLASSQ_H_

struct if_classq {
        struct mbuf     *clq_tail;      /* Tail of packet queue */
};

#ifdef _KERNEL

#define classq_tail(q)  (q)->clq_tail
#define classq_head(q)  ((q)->clq_tail ? (q)->clq_tail->m_nextpkt : NULL)

static __inline void
classq_add(struct if_classq *q, struct mbuf *m)
{
        struct mbuf *m0;

        if ((m0 = classq_tail(q)) != NULL)
                m->m_nextpkt = m0->m_nextpkt;
        else
                m0 = m;
        m0->m_nextpkt = m;
        classq_tail(q) = m;
}

static __inline struct mbuf *
classq_get(struct if_classq *q)
{
        struct mbuf *m, *m0;

        if ((m = classq_tail(q)) == NULL)
                return (NULL);
        if ((m0 = m->m_nextpkt) != m)
                m->m_nextpkt = m0->m_nextpkt;
        else
                classq_tail(q) = NULL;
        m0->m_nextpkt = NULL;
        return (m0);
}

static __inline void
classq_concat(struct if_classq *to, struct if_classq *from)
{
        struct mbuf *head, *tail;

        if (classq_tail(from) == NULL)
                return;
        if (classq_tail(to) == NULL) {
                tail = classq_tail(from);
                goto done;
        }

        head = classq_head(to);

        tail = classq_tail(to);
        tail->m_nextpkt = classq_head(from);

        tail = classq_tail(from);
        tail->m_nextpkt = head;
done:
        classq_tail(to) = tail;
        classq_tail(from) = NULL;
}

#endif  /* _KERNEL */

#endif  /* !_NET_IF_CLASSQ_H_ */