xref: /freebsd/sys/net/altq/altq_classq.h (revision e8e8c939350bdf3c228a411caa9660c607c27a11)
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  * $KAME: altq_classq.h,v 1.6 2003/01/07 07:33:38 kjc Exp $
34  * $FreeBSD$
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 #ifdef __cplusplus
43 extern "C" {
44 #endif
45 
46 /*
47  * Packet Queue types: RED or DROPHEAD.
48  */
49 #define	Q_DROPHEAD	0x00
50 #define	Q_RED		0x01
51 #define	Q_RIO		0x02
52 #define	Q_DROPTAIL	0x03
53 
54 #ifdef _KERNEL
55 
56 /*
57  * Packet Queue structures and macros to manipulate them.
58  */
59 struct _class_queue_ {
60 	struct mbuf	*tail_;	/* Tail of packet queue */
61 	int	qlen_;		/* Queue length (in number of packets) */
62 	int	qlim_;		/* Queue limit (in number of packets*) */
63 	int	qtype_;		/* Queue type */
64 };
65 
66 typedef struct _class_queue_	class_queue_t;
67 
68 #define	qtype(q)	(q)->qtype_		/* Get queue type */
69 #define	qlimit(q)	(q)->qlim_		/* Max packets to be queued */
70 #define	qlen(q)		(q)->qlen_		/* Current queue length. */
71 #define	qtail(q)	(q)->tail_		/* Tail of the queue */
72 #define	qhead(q)	((q)->tail_ ? (q)->tail_->m_nextpkt : NULL)
73 
74 #define	qempty(q)	((q)->qlen_ == 0)	/* Is the queue empty?? */
75 #define	q_is_red(q)	((q)->qtype_ == Q_RED)	/* Is the queue a red queue */
76 #define	q_is_rio(q)	((q)->qtype_ == Q_RIO)	/* Is the queue a rio queue */
77 #define	q_is_red_or_rio(q)	((q)->qtype_ == Q_RED || (q)->qtype_ == Q_RIO)
78 
79 #if !defined(__GNUC__) || defined(ALTQ_DEBUG)
80 
81 extern void		_addq(class_queue_t *, struct mbuf *);
82 extern struct mbuf	*_getq(class_queue_t *);
83 extern struct mbuf	*_getq_tail(class_queue_t *);
84 extern struct mbuf	*_getq_random(class_queue_t *);
85 extern void		_removeq(class_queue_t *, struct mbuf *);
86 extern void		_flushq(class_queue_t *);
87 
88 #else /* __GNUC__ && !ALTQ_DEBUG */
89 /*
90  * inlined versions
91  */
92 static __inline void
93 _addq(class_queue_t *q, struct mbuf *m)
94 {
95         struct mbuf *m0;
96 
97 	if ((m0 = qtail(q)) != NULL)
98 		m->m_nextpkt = m0->m_nextpkt;
99 	else
100 		m0 = m;
101 	m0->m_nextpkt = m;
102 	qtail(q) = m;
103 	qlen(q)++;
104 }
105 
106 static __inline struct mbuf *
107 _getq(class_queue_t *q)
108 {
109 	struct mbuf  *m, *m0;
110 
111 	if ((m = qtail(q)) == NULL)
112 		return (NULL);
113 	if ((m0 = m->m_nextpkt) != m)
114 		m->m_nextpkt = m0->m_nextpkt;
115 	else
116 		qtail(q) = NULL;
117 	qlen(q)--;
118 	m0->m_nextpkt = NULL;
119 	return (m0);
120 }
121 
122 /* drop a packet at the tail of the queue */
123 static __inline struct mbuf *
124 _getq_tail(class_queue_t *q)
125 {
126 	struct mbuf *m, *m0, *prev;
127 
128 	if ((m = m0 = qtail(q)) == NULL)
129 		return NULL;
130 	do {
131 		prev = m0;
132 		m0 = m0->m_nextpkt;
133 	} while (m0 != m);
134 	prev->m_nextpkt = m->m_nextpkt;
135 	if (prev == m)
136 		qtail(q) = NULL;
137 	else
138 		qtail(q) = prev;
139 	qlen(q)--;
140 	m->m_nextpkt = NULL;
141 	return (m);
142 }
143 
144 /* randomly select a packet in the queue */
145 static __inline struct mbuf *
146 _getq_random(class_queue_t *q)
147 {
148 	struct mbuf *m;
149 	int i, n;
150 
151 	if ((m = qtail(q)) == NULL)
152 		return NULL;
153 	if (m->m_nextpkt == m)
154 		qtail(q) = NULL;
155 	else {
156 		struct mbuf *prev = NULL;
157 
158 		n = random() % qlen(q) + 1;
159 		for (i = 0; i < n; i++) {
160 			prev = m;
161 			m = m->m_nextpkt;
162 		}
163 		prev->m_nextpkt = m->m_nextpkt;
164 		if (m == qtail(q))
165 			qtail(q) = prev;
166 	}
167 	qlen(q)--;
168 	m->m_nextpkt = NULL;
169 	return (m);
170 }
171 
172 static __inline void
173 _removeq(class_queue_t *q, struct mbuf *m)
174 {
175 	struct mbuf *m0, *prev;
176 
177 	m0 = qtail(q);
178 	do {
179 		prev = m0;
180 		m0 = m0->m_nextpkt;
181 	} while (m0 != m);
182 	prev->m_nextpkt = m->m_nextpkt;
183 	if (prev == m)
184 		qtail(q) = NULL;
185 	else if (qtail(q) == m)
186 		qtail(q) = prev;
187 	qlen(q)--;
188 }
189 
190 static __inline void
191 _flushq(class_queue_t *q)
192 {
193 	struct mbuf *m;
194 
195 	while ((m = _getq(q)) != NULL)
196 		m_freem(m);
197 }
198 
199 #endif /* __GNUC__ && !ALTQ_DEBUG */
200 
201 #endif /* _KERNEL */
202 
203 #ifdef __cplusplus
204 }
205 #endif
206 
207 #endif /* _ALTQ_ALTQ_CLASSQ_H_ */
208