xref: /freebsd/sys/netpfil/ipfw/dn_sched_prio.c (revision 43a5ec4eb41567cc92586503212743d89686d78f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2010 Riccardo Panicucci, Universita` di Pisa
5  * All rights reserved
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * $FreeBSD$
31  */
32 #ifdef _KERNEL
33 #include <sys/malloc.h>
34 #include <sys/socket.h>
35 #include <sys/socketvar.h>
36 #include <sys/kernel.h>
37 #include <sys/lock.h>
38 #include <sys/mbuf.h>
39 #include <sys/module.h>
40 #include <sys/rwlock.h>
41 #include <net/if.h>	/* IFNAMSIZ */
42 #include <netinet/in.h>
43 #include <netinet/ip_var.h>		/* ipfw_rule_ref */
44 #include <netinet/ip_fw.h>	/* flow_id */
45 #include <netinet/ip_dummynet.h>
46 #include <netpfil/ipfw/ip_fw_private.h>
47 #include <netpfil/ipfw/dn_heap.h>
48 #include <netpfil/ipfw/ip_dn_private.h>
49 #ifdef NEW_AQM
50 #include <netpfil/ipfw/dn_aqm.h>
51 #endif
52 #include <netpfil/ipfw/dn_sched.h>
53 #else
54 #include <dn_test.h>
55 #endif
56 
57 #define DN_SCHED_PRIO	5 //XXX
58 
59 #if !defined(_KERNEL) || !defined(__linux__)
60 #define test_bit(ix, pData)	((*pData) & (1<<(ix)))
61 #define __set_bit(ix, pData)	(*pData) |= (1<<(ix))
62 #define __clear_bit(ix, pData)	(*pData) &= ~(1<<(ix))
63 #endif
64 
65 #ifdef __MIPSEL__
66 #define __clear_bit(ix, pData)	(*pData) &= ~(1<<(ix))
67 #endif
68 
69 /* Size of the array of queues pointers. */
70 #define BITMAP_T	unsigned long
71 #define MAXPRIO		(sizeof(BITMAP_T) * 8)
72 
73 /*
74  * The scheduler instance contains an array of pointers to queues,
75  * one for each priority, and a bitmap listing backlogged queues.
76  */
77 struct prio_si {
78 	BITMAP_T bitmap;			/* array bitmap */
79 	struct dn_queue *q_array[MAXPRIO];	/* Array of queues pointers */
80 };
81 
82 /*
83  * If a queue with the same priority is already backlogged, use
84  * that one instead of the queue passed as argument.
85  */
86 static int
87 prio_enqueue(struct dn_sch_inst *_si, struct dn_queue *q, struct mbuf *m)
88 {
89 	struct prio_si *si = (struct prio_si *)(_si + 1);
90 	int prio = q->fs->fs.par[0];
91 
92 	if (test_bit(prio, &si->bitmap) == 0) {
93 		/* No queue with this priority, insert */
94 		__set_bit(prio, &si->bitmap);
95 		si->q_array[prio] = q;
96 	} else { /* use the existing queue */
97 		q = si->q_array[prio];
98 	}
99 	if (dn_enqueue(q, m, 0))
100 		return 1;
101 	return 0;
102 }
103 
104 /*
105  * Packets are dequeued only from the highest priority queue.
106  * The function ffs() return the lowest bit in the bitmap that rapresent
107  * the array index (-1) which contains the pointer to the highest priority
108  * queue.
109  * After the dequeue, if this queue become empty, it is index is removed
110  * from the bitmap.
111  * Scheduler is idle if the bitmap is empty
112  *
113  * NOTE: highest priority is 0, lowest is sched->max_prio_q
114  */
115 static struct mbuf *
116 prio_dequeue(struct dn_sch_inst *_si)
117 {
118 	struct prio_si *si = (struct prio_si *)(_si + 1);
119 	struct mbuf *m;
120 	struct dn_queue *q;
121 	int prio;
122 
123 	if (si->bitmap == 0) /* scheduler idle */
124 		return NULL;
125 
126 	prio = ffs(si->bitmap) - 1;
127 
128 	/* Take the highest priority queue in the scheduler */
129 	q = si->q_array[prio];
130 	// assert(q)
131 
132 	m = dn_dequeue(q);
133 	if (q->mq.head == NULL) {
134 		/* Queue is now empty, remove from scheduler
135 		 * and mark it
136 		 */
137 		si->q_array[prio] = NULL;
138 		__clear_bit(prio, &si->bitmap);
139 	}
140 	return m;
141 }
142 
143 static int
144 prio_new_sched(struct dn_sch_inst *_si)
145 {
146 	struct prio_si *si = (struct prio_si *)(_si + 1);
147 
148 	bzero(si->q_array, sizeof(si->q_array));
149 	si->bitmap = 0;
150 
151 	return 0;
152 }
153 
154 static int
155 prio_new_fsk(struct dn_fsk *fs)
156 {
157 	/* Check if the prioritiy is between 0 and MAXPRIO-1 */
158 	ipdn_bound_var(&fs->fs.par[0], 0, 0, MAXPRIO - 1, "PRIO priority");
159 	return 0;
160 }
161 
162 static int
163 prio_new_queue(struct dn_queue *q)
164 {
165 	struct prio_si *si = (struct prio_si *)(q->_si + 1);
166 	int prio = q->fs->fs.par[0];
167 	struct dn_queue *oldq;
168 
169 	q->ni.oid.subtype = DN_SCHED_PRIO;
170 
171 	if (q->mq.head == NULL)
172 		return 0;
173 
174 	/* Queue already full, must insert in the scheduler or append
175 	 * mbufs to existing queue. This partly duplicates prio_enqueue
176 	 */
177 	if (test_bit(prio, &si->bitmap) == 0) {
178 		/* No queue with this priority, insert */
179 		__set_bit(prio, &si->bitmap);
180 		si->q_array[prio] = q;
181 	} else if ( (oldq = si->q_array[prio]) != q) {
182 		/* must append to the existing queue.
183 		 * can simply append q->mq.head to q2->...
184 		 * and add the counters to those of q2
185 		 */
186 		oldq->mq.tail->m_nextpkt = q->mq.head;
187 		oldq->mq.tail = q->mq.tail;
188 		oldq->ni.length += q->ni.length;
189 		q->ni.length = 0;
190 		oldq->ni.len_bytes += q->ni.len_bytes;
191 		q->ni.len_bytes = 0;
192 		q->mq.tail = q->mq.head = NULL;
193 	}
194 	return 0;
195 }
196 
197 static int
198 prio_free_queue(struct dn_queue *q)
199 {
200 	int prio = q->fs->fs.par[0];
201 	struct prio_si *si = (struct prio_si *)(q->_si + 1);
202 
203 	if (si->q_array[prio] == q) {
204 		si->q_array[prio] = NULL;
205 		__clear_bit(prio, &si->bitmap);
206 	}
207 	return 0;
208 }
209 
210 static struct dn_alg prio_desc = {
211 	_SI( .type = ) DN_SCHED_PRIO,
212 	_SI( .name = ) "PRIO",
213 	_SI( .flags = ) DN_MULTIQUEUE,
214 
215 	/* we need extra space in the si and the queue */
216 	_SI( .schk_datalen = ) 0,
217 	_SI( .si_datalen = ) sizeof(struct prio_si),
218 	_SI( .q_datalen = ) 0,
219 
220 	_SI( .enqueue = ) prio_enqueue,
221 	_SI( .dequeue = ) prio_dequeue,
222 
223 	_SI( .config = )  NULL,
224 	_SI( .destroy = )  NULL,
225 	_SI( .new_sched = ) prio_new_sched,
226 	_SI( .free_sched = ) NULL,
227 
228 	_SI( .new_fsk = ) prio_new_fsk,
229 	_SI( .free_fsk = )  NULL,
230 
231 	_SI( .new_queue = ) prio_new_queue,
232 	_SI( .free_queue = ) prio_free_queue,
233 #ifdef NEW_AQM
234 	_SI( .getconfig = )  NULL,
235 #endif
236 };
237 
238 DECLARE_DNSCHED_MODULE(dn_prio, &prio_desc);
239