xref: /freebsd/sys/netpfil/ipfw/dn_sched_prio.c (revision ca987d4641cdcd7f27e153db17c5bf064934faf5)
1 /*
2  * Copyright (c) 2010 Riccardo Panicucci, Universita` di Pisa
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  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 /*
28  * $FreeBSD$
29  */
30 #ifdef _KERNEL
31 #include <sys/malloc.h>
32 #include <sys/socket.h>
33 #include <sys/socketvar.h>
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/mbuf.h>
37 #include <sys/module.h>
38 #include <sys/rwlock.h>
39 #include <net/if.h>	/* IFNAMSIZ */
40 #include <netinet/in.h>
41 #include <netinet/ip_var.h>		/* ipfw_rule_ref */
42 #include <netinet/ip_fw.h>	/* flow_id */
43 #include <netinet/ip_dummynet.h>
44 #include <netpfil/ipfw/ip_fw_private.h>
45 #include <netpfil/ipfw/dn_heap.h>
46 #include <netpfil/ipfw/ip_dn_private.h>
47 #ifdef NEW_AQM
48 #include <netpfil/ipfw/dn_aqm.h>
49 #endif
50 #include <netpfil/ipfw/dn_sched.h>
51 #else
52 #include <dn_test.h>
53 #endif
54 
55 #define DN_SCHED_PRIO	5 //XXX
56 
57 #if !defined(_KERNEL) || !defined(__linux__)
58 #define test_bit(ix, pData)	((*pData) & (1<<(ix)))
59 #define __set_bit(ix, pData)	(*pData) |= (1<<(ix))
60 #define __clear_bit(ix, pData)	(*pData) &= ~(1<<(ix))
61 #endif
62 
63 #ifdef __MIPSEL__
64 #define __clear_bit(ix, pData)	(*pData) &= ~(1<<(ix))
65 #endif
66 
67 /* Size of the array of queues pointers. */
68 #define BITMAP_T	unsigned long
69 #define MAXPRIO		(sizeof(BITMAP_T) * 8)
70 
71 /*
72  * The scheduler instance contains an array of pointers to queues,
73  * one for each priority, and a bitmap listing backlogged queues.
74  */
75 struct prio_si {
76 	BITMAP_T bitmap;			/* array bitmap */
77 	struct dn_queue *q_array[MAXPRIO];	/* Array of queues pointers */
78 };
79 
80 /*
81  * If a queue with the same priority is already backlogged, use
82  * that one instead of the queue passed as argument.
83  */
84 static int
85 prio_enqueue(struct dn_sch_inst *_si, struct dn_queue *q, struct mbuf *m)
86 {
87 	struct prio_si *si = (struct prio_si *)(_si + 1);
88 	int prio = q->fs->fs.par[0];
89 
90 	if (test_bit(prio, &si->bitmap) == 0) {
91 		/* No queue with this priority, insert */
92 		__set_bit(prio, &si->bitmap);
93 		si->q_array[prio] = q;
94 	} else { /* use the existing queue */
95 		q = si->q_array[prio];
96 	}
97 	if (dn_enqueue(q, m, 0))
98 		return 1;
99 	return 0;
100 }
101 
102 /*
103  * Packets are dequeued only from the highest priority queue.
104  * The function ffs() return the lowest bit in the bitmap that rapresent
105  * the array index (-1) which contains the pointer to the highest priority
106  * queue.
107  * After the dequeue, if this queue become empty, it is index is removed
108  * from the bitmap.
109  * Scheduler is idle if the bitmap is empty
110  *
111  * NOTE: highest priority is 0, lowest is sched->max_prio_q
112  */
113 static struct mbuf *
114 prio_dequeue(struct dn_sch_inst *_si)
115 {
116 	struct prio_si *si = (struct prio_si *)(_si + 1);
117 	struct mbuf *m;
118 	struct dn_queue *q;
119 	int prio;
120 
121 	if (si->bitmap == 0) /* scheduler idle */
122 		return NULL;
123 
124 	prio = ffs(si->bitmap) - 1;
125 
126 	/* Take the highest priority queue in the scheduler */
127 	q = si->q_array[prio];
128 	// assert(q)
129 
130 	m = dn_dequeue(q);
131 	if (q->mq.head == NULL) {
132 		/* Queue is now empty, remove from scheduler
133 		 * and mark it
134 		 */
135 		si->q_array[prio] = NULL;
136 		__clear_bit(prio, &si->bitmap);
137 	}
138 	return m;
139 }
140 
141 static int
142 prio_new_sched(struct dn_sch_inst *_si)
143 {
144 	struct prio_si *si = (struct prio_si *)(_si + 1);
145 
146 	bzero(si->q_array, sizeof(si->q_array));
147 	si->bitmap = 0;
148 
149 	return 0;
150 }
151 
152 static int
153 prio_new_fsk(struct dn_fsk *fs)
154 {
155 	/* Check if the prioritiy is between 0 and MAXPRIO-1 */
156 	ipdn_bound_var(&fs->fs.par[0], 0, 0, MAXPRIO - 1, "PRIO priority");
157 	return 0;
158 }
159 
160 static int
161 prio_new_queue(struct dn_queue *q)
162 {
163 	struct prio_si *si = (struct prio_si *)(q->_si + 1);
164 	int prio = q->fs->fs.par[0];
165 	struct dn_queue *oldq;
166 
167 	q->ni.oid.subtype = DN_SCHED_PRIO;
168 
169 	if (q->mq.head == NULL)
170 		return 0;
171 
172 	/* Queue already full, must insert in the scheduler or append
173 	 * mbufs to existing queue. This partly duplicates prio_enqueue
174 	 */
175 	if (test_bit(prio, &si->bitmap) == 0) {
176 		/* No queue with this priority, insert */
177 		__set_bit(prio, &si->bitmap);
178 		si->q_array[prio] = q;
179 	} else if ( (oldq = si->q_array[prio]) != q) {
180 		/* must append to the existing queue.
181 		 * can simply append q->mq.head to q2->...
182 		 * and add the counters to those of q2
183 		 */
184 		oldq->mq.tail->m_nextpkt = q->mq.head;
185 		oldq->mq.tail = q->mq.tail;
186 		oldq->ni.length += q->ni.length;
187 		q->ni.length = 0;
188 		oldq->ni.len_bytes += q->ni.len_bytes;
189 		q->ni.len_bytes = 0;
190 		q->mq.tail = q->mq.head = NULL;
191 	}
192 	return 0;
193 }
194 
195 static int
196 prio_free_queue(struct dn_queue *q)
197 {
198 	int prio = q->fs->fs.par[0];
199 	struct prio_si *si = (struct prio_si *)(q->_si + 1);
200 
201 	if (si->q_array[prio] == q) {
202 		si->q_array[prio] = NULL;
203 		__clear_bit(prio, &si->bitmap);
204 	}
205 	return 0;
206 }
207 
208 
209 static struct dn_alg prio_desc = {
210 	_SI( .type = ) DN_SCHED_PRIO,
211 	_SI( .name = ) "PRIO",
212 	_SI( .flags = ) DN_MULTIQUEUE,
213 
214 	/* we need extra space in the si and the queue */
215 	_SI( .schk_datalen = ) 0,
216 	_SI( .si_datalen = ) sizeof(struct prio_si),
217 	_SI( .q_datalen = ) 0,
218 
219 	_SI( .enqueue = ) prio_enqueue,
220 	_SI( .dequeue = ) prio_dequeue,
221 
222 	_SI( .config = )  NULL,
223 	_SI( .destroy = )  NULL,
224 	_SI( .new_sched = ) prio_new_sched,
225 	_SI( .free_sched = ) NULL,
226 
227 	_SI( .new_fsk = ) prio_new_fsk,
228 	_SI( .free_fsk = )  NULL,
229 
230 	_SI( .new_queue = ) prio_new_queue,
231 	_SI( .free_queue = ) prio_free_queue,
232 #ifdef NEW_AQM
233 	_SI( .getconfig = )  NULL,
234 #endif
235 };
236 
237 
238 DECLARE_DNSCHED_MODULE(dn_prio, &prio_desc);
239