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 */
77struct 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 */
86static int
87prio_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 */
115static struct mbuf *
116prio_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
143static int
144prio_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
154static int
155prio_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
162static int
163prio_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
197static int
198prio_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
211static struct dn_alg prio_desc = {
212	_SI( .type = ) DN_SCHED_PRIO,
213	_SI( .name = ) "PRIO",
214	_SI( .flags = ) DN_MULTIQUEUE,
215
216	/* we need extra space in the si and the queue */
217	_SI( .schk_datalen = ) 0,
218	_SI( .si_datalen = ) sizeof(struct prio_si),
219	_SI( .q_datalen = ) 0,
220
221	_SI( .enqueue = ) prio_enqueue,
222	_SI( .dequeue = ) prio_dequeue,
223
224	_SI( .config = )  NULL,
225	_SI( .destroy = )  NULL,
226	_SI( .new_sched = ) prio_new_sched,
227	_SI( .free_sched = ) NULL,
228
229	_SI( .new_fsk = ) prio_new_fsk,
230	_SI( .free_fsk = )  NULL,
231
232	_SI( .new_queue = ) prio_new_queue,
233	_SI( .free_queue = ) prio_free_queue,
234#ifdef NEW_AQM
235	_SI( .getconfig = )  NULL,
236#endif
237};
238
239
240DECLARE_DNSCHED_MODULE(dn_prio, &prio_desc);
241