sys/net/altq/if_classq.h

   1 /*
   2  * Copyright (c) 1991-1997 Regents of the University of California.
   3  * 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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the Network Research
  16  *      Group at Lawrence Berkeley Laboratory.
  17  * 4. Neither the name of the University nor of the Laboratory may be used
  18  *    to endorse or promote products derived from this software without
  19  *    specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33 /*
  34  * class queue definitions extracted from altq_classq.h.
  35  */
  36
  37 #ifndef _NET_IF_CLASSQ_H_
  38 #define _NET_IF_CLASSQ_H_
  39
  40 struct if_classq {
  41         struct mbuf     *clq_tail;      /* Tail of packet queue */
  42 };
  43
  44 #ifdef _KERNEL
  45
  46 #define classq_tail(q)  (q)->clq_tail
  47 #define classq_head(q)  ((q)->clq_tail ? (q)->clq_tail->m_nextpkt : NULL)
  48
  49 static __inline void
  50 classq_add(struct if_classq *q, struct mbuf *m)
  51 {
  52         struct mbuf *m0;
  53
  54         if ((m0 = classq_tail(q)) != NULL)
  55                 m->m_nextpkt = m0->m_nextpkt;
  56         else
  57                 m0 = m;
  58         m0->m_nextpkt = m;
  59         classq_tail(q) = m;
  60 }
  61
  62 static __inline struct mbuf *
  63 classq_get(struct if_classq *q)
  64 {
  65         struct mbuf *m, *m0;
  66
  67         if ((m = classq_tail(q)) == NULL)
  68                 return (NULL);
  69         if ((m0 = m->m_nextpkt) != m)
  70                 m->m_nextpkt = m0->m_nextpkt;
  71         else
  72                 classq_tail(q) = NULL;
  73         m0->m_nextpkt = NULL;
  74         return (m0);
  75 }
  76
  77 #endif  /* _KERNEL */
  78
  79 #endif  /* !_NET_IF_CLASSQ_H_ */