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 */
69struct 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 */
78static int
79prio_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 */
107static struct mbuf *
108prio_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
135static int
136prio_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
146static int
147prio_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
154static int
155prio_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
189static int
190prio_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
203static 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
229DECLARE_DNSCHED_MODULE(dn_prio, &prio_desc);
230