xref: /dragonfly/sys/net/altq/if_classq.h (revision 0066c2fb)
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 static __inline void
78 classq_concat(struct if_classq *to, struct if_classq *from)
79 {
80 	struct mbuf *head, *tail;
81 
82 	if (classq_tail(from) == NULL)
83 		return;
84 	if (classq_tail(to) == NULL) {
85 		tail = classq_tail(from);
86 		goto done;
87 	}
88 
89 	head = classq_head(to);
90 
91 	tail = classq_tail(to);
92 	tail->m_nextpkt = classq_head(from);
93 
94 	tail = classq_tail(from);
95 	tail->m_nextpkt = head;
96 done:
97 	classq_tail(to) = tail;
98 	classq_tail(from) = NULL;
99 }
100 
101 #endif	/* _KERNEL */
102 
103 #endif	/* !_NET_IF_CLASSQ_H_ */
104