xref: /freebsd/sys/netpfil/ipfw/dn_sched_prio.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
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/mbuf.h>
36 #include <sys/module.h>
37 #include <net/if.h>	/* IFNAMSIZ */
38 #include <netinet/in.h>
39 #include <netinet/ip_var.h>		/* ipfw_rule_ref */
40 #include <netinet/ip_fw.h>	/* flow_id */
41 #include <netinet/ip_dummynet.h>
42 #include <netpfil/ipfw/dn_heap.h>
43 #include <netpfil/ipfw/ip_dn_private.h>
44 #include <netpfil/ipfw/dn_sched.h>
45 #else
46 #include <dn_test.h>
47 #endif
48 
49 #define DN_SCHED_PRIO	5 //XXX
50 
51 #if !defined(_KERNEL) || !defined(__linux__)
52 #define test_bit(ix, pData)	((*pData) & (1<<(ix)))
53 #define __set_bit(ix, pData)	(*pData) |= (1<<(ix))
54 #define __clear_bit(ix, pData)	(*pData) &= ~(1<<(ix))
55 #endif
56 
57 #ifdef __MIPSEL__
58 #define __clear_bit(ix, pData)	(*pData) &= ~(1<<(ix))
59 #endif
60 
61 /* Size of the array of queues pointers. */
62 #define BITMAP_T	unsigned long
63 #define MAXPRIO		(sizeof(BITMAP_T) * 8)
64 
65 /*
66  * The scheduler instance contains an array of pointers to queues,
67  * one for each priority, and a bitmap listing backlogged queues.
68  */
69 struct prio_si {
70 	BITMAP_T bitmap;			/* array bitmap */
71 	struct dn_queue *q_array[MAXPRIO];	/* Array of queues pointers */
72 };
73 
74 /*
75  * If a queue with the same priority is already backlogged, use
76  * that one instead of the queue passed as argument.
77  */
78 static int
79 prio_enqueue(struct dn_sch_inst *_si, struct dn_queue *q, struct mbuf *m)
80 {
81 	struct prio_si *si = (struct prio_si *)(_si + 1);
82 	int prio = q->fs->fs.par[0];
83 
84 	if (test_bit(prio, &si->bitmap) == 0) {
85 		/* No queue with this priority, insert */
86 		__set_bit(prio, &si->bitmap);
87 		si->q_array[prio] = q;
88 	} else { /* use the existing queue */
89 		q = si->q_array[prio];
90 	}
91 	if (dn_enqueue(q, m, 0))
92 		return 1;
93 	return 0;
94 }
95 
96 /*
97  * Packets are dequeued only from the highest priority queue.
98  * The function ffs() return the lowest bit in the bitmap that rapresent
99  * the array index (-1) which contains the pointer to the highest priority
100  * queue.
101  * After the dequeue, if this queue become empty, it is index is removed
102  * from the bitmap.
103  * Scheduler is idle if the bitmap is empty
104  *
105  * NOTE: highest priority is 0, lowest is sched->max_prio_q
106  */
107 static struct mbuf *
108 prio_dequeue(struct dn_sch_inst *_si)
109 {
110 	struct prio_si *si = (struct prio_si *)(_si + 1);
111 	struct mbuf *m;
112 	struct dn_queue *q;
113 	int prio;
114 
115 	if (si->bitmap == 0) /* scheduler idle */
116 		return NULL;
117 
118 	prio = ffs(si->bitmap) - 1;
119 
120 	/* Take the highest priority queue in the scheduler */
121 	q = si->q_array[prio];
122 	// assert(q)
123 
124 	m = dn_dequeue(q);
125 	if (q->mq.head == NULL) {
126 		/* Queue is now empty, remove from scheduler
127 		 * and mark it
128 		 */
129 		si->q_array[prio] = NULL;
130 		__clear_bit(prio, &si->bitmap);
131 	}
132 	return m;
133 }
134 
135 static int
136 prio_new_sched(struct dn_sch_inst *_si)
137 {
138 	struct prio_si *si = (struct prio_si *)(_si + 1);
139 
140 	bzero(si->q_array, sizeof(si->q_array));
141 	si->bitmap = 0;
142 
143 	return 0;
144 }
145 
146 static int
147 prio_new_fsk(struct dn_fsk *fs)
148 {
149 	/* Check if the prioritiy is between 0 and MAXPRIO-1 */
150 	ipdn_bound_var(&fs->fs.par[0], 0, 0, MAXPRIO - 1, "PRIO priority");
151 	return 0;
152 }
153 
154 static int
155 prio_new_queue(struct dn_queue *q)
156 {
157 	struct prio_si *si = (struct prio_si *)(q->_si + 1);
158 	int prio = q->fs->fs.par[0];
159 	struct dn_queue *oldq;
160 
161 	q->ni.oid.subtype = DN_SCHED_PRIO;
162 
163 	if (q->mq.head == NULL)
164 		return 0;
165 
166 	/* Queue already full, must insert in the scheduler or append
167 	 * mbufs to existing queue. This partly duplicates prio_enqueue
168 	 */
169 	if (test_bit(prio, &si->bitmap) == 0) {
170 		/* No queue with this priority, insert */
171 		__set_bit(prio, &si->bitmap);
172 		si->q_array[prio] = q;
173 	} else if ( (oldq = si->q_array[prio]) != q) {
174 		/* must append to the existing queue.
175 		 * can simply append q->mq.head to q2->...
176 		 * and add the counters to those of q2
177 		 */
178 		oldq->mq.tail->m_nextpkt = q->mq.head;
179 		oldq->mq.tail = q->mq.tail;
180 		oldq->ni.length += q->ni.length;
181 		q->ni.length = 0;
182 		oldq->ni.len_bytes += q->ni.len_bytes;
183 		q->ni.len_bytes = 0;
184 		q->mq.tail = q->mq.head = NULL;
185 	}
186 	return 0;
187 }
188 
189 static int
190 prio_free_queue(struct dn_queue *q)
191 {
192 	int prio = q->fs->fs.par[0];
193 	struct prio_si *si = (struct prio_si *)(q->_si + 1);
194 
195 	if (si->q_array[prio] == q) {
196 		si->q_array[prio] = NULL;
197 		__clear_bit(prio, &si->bitmap);
198 	}
199 	return 0;
200 }
201 
202 
203 static struct dn_alg prio_desc = {
204 	_SI( .type = ) DN_SCHED_PRIO,
205 	_SI( .name = ) "PRIO",
206 	_SI( .flags = ) DN_MULTIQUEUE,
207 
208 	/* we need extra space in the si and the queue */
209 	_SI( .schk_datalen = ) 0,
210 	_SI( .si_datalen = ) sizeof(struct prio_si),
211 	_SI( .q_datalen = ) 0,
212 
213 	_SI( .enqueue = ) prio_enqueue,
214 	_SI( .dequeue = ) prio_dequeue,
215 
216 	_SI( .config = )  NULL,
217 	_SI( .destroy = )  NULL,
218 	_SI( .new_sched = ) prio_new_sched,
219 	_SI( .free_sched = ) NULL,
220 
221 	_SI( .new_fsk = ) prio_new_fsk,
222 	_SI( .free_fsk = )  NULL,
223 
224 	_SI( .new_queue = ) prio_new_queue,
225 	_SI( .free_queue = ) prio_free_queue,
226 };
227 
228 
229 DECLARE_DNSCHED_MODULE(dn_prio, &prio_desc);
230