xref: /dragonfly/sys/net/altq/altq_classq.h (revision 0ca59c34)
1 /*	$KAME: altq_classq.h,v 1.6 2003/01/07 07:33:38 kjc Exp $	*/
2 /*	$DragonFly: src/sys/net/altq/altq_classq.h,v 1.2 2006/09/03 18:52:29 dillon Exp $ */
3 
4 /*
5  * Copyright (c) 1991-1997 Regents of the University of California.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the Network Research
19  *	Group at Lawrence Berkeley Laboratory.
20  * 4. Neither the name of the University nor of the Laboratory may be used
21  *    to endorse or promote products derived from this software without
22  *    specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 /*
37  * class queue definitions extracted from rm_class.h.
38  */
39 #ifndef _ALTQ_ALTQ_CLASSQ_H_
40 #define	_ALTQ_ALTQ_CLASSQ_H_
41 
42 /*
43  * Packet Queue types: RED or DROPHEAD.
44  */
45 #define	Q_DROPHEAD	0x00
46 #define	Q_RED		0x01
47 #define	Q_RIO		0x02
48 #define	Q_DROPTAIL	0x03
49 
50 #ifdef _KERNEL
51 
52 /*
53  * Packet Queue structures and macros to manipulate them.
54  */
55 struct _class_queue_ {
56 	struct mbuf	*tail_;	/* Tail of packet queue */
57 	int	qlen_;		/* Queue length (in number of packets) */
58 	int	qlim_;		/* Queue limit (in number of packets*) */
59 	int	qtype_;		/* Queue type */
60 };
61 
62 typedef struct _class_queue_	class_queue_t;
63 
64 #define	qtype(q)	(q)->qtype_		/* Get queue type */
65 #define	qlimit(q)	(q)->qlim_		/* Max packets to be queued */
66 #define	qlen(q)		(q)->qlen_		/* Current queue length. */
67 #define	qtail(q)	(q)->tail_		/* Tail of the queue */
68 #define	qhead(q)	((q)->tail_ ? (q)->tail_->m_nextpkt : NULL)
69 
70 #define	qempty(q)	((q)->qlen_ == 0)	/* Is the queue empty?? */
71 #define	q_is_red(q)	((q)->qtype_ == Q_RED)	/* Is the queue a red queue */
72 #define	q_is_rio(q)	((q)->qtype_ == Q_RIO)	/* Is the queue a rio queue */
73 #define	q_is_red_or_rio(q)	((q)->qtype_ == Q_RED || (q)->qtype_ == Q_RIO)
74 
75 static __inline void
76 _addq(class_queue_t *q, struct mbuf *m)
77 {
78         struct mbuf *m0;
79 
80 	if ((m0 = qtail(q)) != NULL)
81 		m->m_nextpkt = m0->m_nextpkt;
82 	else
83 		m0 = m;
84 	m0->m_nextpkt = m;
85 	qtail(q) = m;
86 	qlen(q)++;
87 }
88 
89 static __inline struct mbuf *
90 _getq(class_queue_t *q)
91 {
92 	struct mbuf  *m, *m0;
93 
94 	if ((m = qtail(q)) == NULL)
95 		return (NULL);
96 	if ((m0 = m->m_nextpkt) != m)
97 		m->m_nextpkt = m0->m_nextpkt;
98 	else
99 		qtail(q) = NULL;
100 	qlen(q)--;
101 	m0->m_nextpkt = NULL;
102 	return (m0);
103 }
104 
105 /* drop a packet at the tail of the queue */
106 static __inline struct mbuf *
107 _getq_tail(class_queue_t *q)
108 {
109 	struct mbuf *m, *m0, *prev;
110 
111 	if ((m = m0 = qtail(q)) == NULL)
112 		return NULL;
113 	do {
114 		prev = m0;
115 		m0 = m0->m_nextpkt;
116 	} while (m0 != m);
117 	prev->m_nextpkt = m->m_nextpkt;
118 	if (prev == m)
119 		qtail(q) = NULL;
120 	else
121 		qtail(q) = prev;
122 	qlen(q)--;
123 	m->m_nextpkt = NULL;
124 	return (m);
125 }
126 
127 /* randomly select a packet in the queue */
128 static __inline struct mbuf *
129 _getq_random(class_queue_t *q)
130 {
131 	struct mbuf *m;
132 	int i, n;
133 
134 	if ((m = qtail(q)) == NULL)
135 		return NULL;
136 	if (m->m_nextpkt == m)
137 		qtail(q) = NULL;
138 	else {
139 		struct mbuf *prev = NULL;
140 
141 		n = krandom() % qlen(q) + 1;
142 		for (i = 0; i < n; i++) {
143 			prev = m;
144 			m = m->m_nextpkt;
145 		}
146 		prev->m_nextpkt = m->m_nextpkt;
147 		if (m == qtail(q))
148 			qtail(q) = prev;
149 	}
150 	qlen(q)--;
151 	m->m_nextpkt = NULL;
152 	return (m);
153 }
154 
155 static __inline void
156 _removeq(class_queue_t *q, struct mbuf *m)
157 {
158 	struct mbuf *m0, *prev;
159 
160 	m0 = qtail(q);
161 	do {
162 		prev = m0;
163 		m0 = m0->m_nextpkt;
164 	} while (m0 != m);
165 	prev->m_nextpkt = m->m_nextpkt;
166 	if (prev == m)
167 		qtail(q) = NULL;
168 	else if (qtail(q) == m)
169 		qtail(q) = prev;
170 	qlen(q)--;
171 }
172 
173 static __inline void
174 _flushq(class_queue_t *q)
175 {
176 	struct mbuf *m;
177 
178 	while ((m = _getq(q)) != NULL)
179 		m_freem(m);
180 }
181 
182 #endif /* _KERNEL */
183 
184 #endif /* _ALTQ_ALTQ_CLASSQ_H_ */
185