xref: /freebsd/sys/netpfil/ipfw/dn_sched_rr.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 
31 #ifdef _KERNEL
32 #include <sys/malloc.h>
33 #include <sys/socket.h>
34 #include <sys/socketvar.h>
35 #include <sys/kernel.h>
36 #include <sys/mbuf.h>
37 #include <sys/module.h>
38 #include <net/if.h>	/* IFNAMSIZ */
39 #include <netinet/in.h>
40 #include <netinet/ip_var.h>		/* ipfw_rule_ref */
41 #include <netinet/ip_fw.h>	/* flow_id */
42 #include <netinet/ip_dummynet.h>
43 #include <netpfil/ipfw/dn_heap.h>
44 #include <netpfil/ipfw/ip_dn_private.h>
45 #include <netpfil/ipfw/dn_sched.h>
46 #else
47 #include <dn_test.h>
48 #endif
49 
50 #define DN_SCHED_RR	3 // XXX Where?
51 
52 struct rr_queue {
53 	struct dn_queue q;		/* Standard queue */
54 	int status;			/* 1: queue is in the list */
55 	int credit;			/* Number of bytes to transmit */
56 	int quantum;			/* quantum * C */
57 	struct rr_queue *qnext;		/* */
58 };
59 
60 /* struct rr_schk contains global config parameters
61  * and is right after dn_schk
62  */
63 struct rr_schk {
64 	int min_q;		/* Min quantum */
65 	int max_q;		/* Max quantum */
66 	int q_bytes;		/* Bytes per quantum */
67 };
68 
69 /* per-instance round robin list, right after dn_sch_inst */
70 struct rr_si {
71 	struct rr_queue *head, *tail;	/* Pointer to current queue */
72 };
73 
74 /* Append a queue to the rr list */
75 static inline void
76 rr_append(struct rr_queue *q, struct rr_si *si)
77 {
78 	q->status = 1;		/* mark as in-rr_list */
79 	q->credit = q->quantum;	/* initialize credit */
80 
81 	/* append to the tail */
82 	if (si->head == NULL)
83 		si->head = q;
84 	else
85 		si->tail->qnext = q;
86 	si->tail = q;		/* advance the tail pointer */
87 	q->qnext = si->head;	/* make it circular */
88 }
89 
90 /* Remove the head queue from circular list. */
91 static inline void
92 rr_remove_head(struct rr_si *si)
93 {
94 	if (si->head == NULL)
95 		return; /* empty queue */
96 	si->head->status = 0;
97 
98 	if (si->head == si->tail) {
99 		si->head = si->tail = NULL;
100 		return;
101 	}
102 
103 	si->head = si->head->qnext;
104 	si->tail->qnext = si->head;
105 }
106 
107 /* Remove a queue from circular list.
108  * XXX see if ti can be merge with remove_queue()
109  */
110 static inline void
111 remove_queue_q(struct rr_queue *q, struct rr_si *si)
112 {
113 	struct rr_queue *prev;
114 
115 	if (q->status != 1)
116 		return;
117 	if (q == si->head) {
118 		rr_remove_head(si);
119 		return;
120 	}
121 
122 	for (prev = si->head; prev; prev = prev->qnext) {
123 		if (prev->qnext != q)
124 			continue;
125 		prev->qnext = q->qnext;
126 		if (q == si->tail)
127 			si->tail = prev;
128 		q->status = 0;
129 		break;
130 	}
131 }
132 
133 
134 static inline void
135 next_pointer(struct rr_si *si)
136 {
137 	if (si->head == NULL)
138 		return; /* empty queue */
139 
140 	si->head = si->head->qnext;
141 	si->tail = si->tail->qnext;
142 }
143 
144 static int
145 rr_enqueue(struct dn_sch_inst *_si, struct dn_queue *q, struct mbuf *m)
146 {
147 	struct rr_si *si;
148 	struct rr_queue *rrq;
149 
150 	if (m != q->mq.head) {
151 		if (dn_enqueue(q, m, 0)) /* packet was dropped */
152 			return 1;
153 		if (m != q->mq.head)
154 			return 0;
155 	}
156 
157 	/* If reach this point, queue q was idle */
158 	si = (struct rr_si *)(_si + 1);
159 	rrq = (struct rr_queue *)q;
160 
161 	if (rrq->status == 1) /* Queue is already in the queue list */
162 		return 0;
163 
164 	/* Insert the queue in the queue list */
165 	rr_append(rrq, si);
166 
167 	return 0;
168 }
169 
170 static struct mbuf *
171 rr_dequeue(struct dn_sch_inst *_si)
172 {
173 	/* Access scheduler instance private data */
174 	struct rr_si *si = (struct rr_si *)(_si + 1);
175 	struct rr_queue *rrq;
176 	uint64_t len;
177 
178 	while ( (rrq = si->head) ) {
179 		struct mbuf *m = rrq->q.mq.head;
180 		if ( m == NULL) {
181 			/* empty queue, remove from list */
182 			rr_remove_head(si);
183 			continue;
184 		}
185 		len = m->m_pkthdr.len;
186 
187 		if (len > rrq->credit) {
188 			/* Packet too big */
189 			rrq->credit += rrq->quantum;
190 			/* Try next queue */
191 			next_pointer(si);
192 		} else {
193 			rrq->credit -= len;
194 			return dn_dequeue(&rrq->q);
195 		}
196 	}
197 
198 	/* no packet to dequeue*/
199 	return NULL;
200 }
201 
202 static int
203 rr_config(struct dn_schk *_schk)
204 {
205 	struct rr_schk *schk = (struct rr_schk *)(_schk + 1);
206 	ND("called");
207 
208 	/* use reasonable quantums (64..2k bytes, default 1500) */
209 	schk->min_q = 64;
210 	schk->max_q = 2048;
211 	schk->q_bytes = 1500;	/* quantum */
212 
213 	return 0;
214 }
215 
216 static int
217 rr_new_sched(struct dn_sch_inst *_si)
218 {
219 	struct rr_si *si = (struct rr_si *)(_si + 1);
220 
221 	ND("called");
222 	si->head = si->tail = NULL;
223 
224 	return 0;
225 }
226 
227 static int
228 rr_free_sched(struct dn_sch_inst *_si)
229 {
230 	ND("called");
231 	/* Nothing to do? */
232 	return 0;
233 }
234 
235 static int
236 rr_new_fsk(struct dn_fsk *fs)
237 {
238 	struct rr_schk *schk = (struct rr_schk *)(fs->sched + 1);
239 	/* par[0] is the weight, par[1] is the quantum step */
240 	ipdn_bound_var(&fs->fs.par[0], 1,
241 		1, 65536, "RR weight");
242 	ipdn_bound_var(&fs->fs.par[1], schk->q_bytes,
243 		schk->min_q, schk->max_q, "RR quantum");
244 	return 0;
245 }
246 
247 static int
248 rr_new_queue(struct dn_queue *_q)
249 {
250 	struct rr_queue *q = (struct rr_queue *)_q;
251 
252 	_q->ni.oid.subtype = DN_SCHED_RR;
253 
254 	q->quantum = _q->fs->fs.par[0] * _q->fs->fs.par[1];
255 	ND("called, q->quantum %d", q->quantum);
256 	q->credit = q->quantum;
257 	q->status = 0;
258 
259 	if (_q->mq.head != NULL) {
260 		/* Queue NOT empty, insert in the queue list */
261 		rr_append(q, (struct rr_si *)(_q->_si + 1));
262 	}
263 	return 0;
264 }
265 
266 static int
267 rr_free_queue(struct dn_queue *_q)
268 {
269 	struct rr_queue *q = (struct rr_queue *)_q;
270 
271 	ND("called");
272 	if (q->status == 1) {
273 		struct rr_si *si = (struct rr_si *)(_q->_si + 1);
274 		remove_queue_q(q, si);
275 	}
276 	return 0;
277 }
278 
279 /*
280  * RR scheduler descriptor
281  * contains the type of the scheduler, the name, the size of the
282  * structures and function pointers.
283  */
284 static struct dn_alg rr_desc = {
285 	_SI( .type = ) DN_SCHED_RR,
286 	_SI( .name = ) "RR",
287 	_SI( .flags = ) DN_MULTIQUEUE,
288 
289 	_SI( .schk_datalen = ) 0,
290 	_SI( .si_datalen = ) sizeof(struct rr_si),
291 	_SI( .q_datalen = ) sizeof(struct rr_queue) - sizeof(struct dn_queue),
292 
293 	_SI( .enqueue = ) rr_enqueue,
294 	_SI( .dequeue = ) rr_dequeue,
295 
296 	_SI( .config = ) rr_config,
297 	_SI( .destroy = ) NULL,
298 	_SI( .new_sched = ) rr_new_sched,
299 	_SI( .free_sched = ) rr_free_sched,
300 	_SI( .new_fsk = ) rr_new_fsk,
301 	_SI( .free_fsk = ) NULL,
302 	_SI( .new_queue = ) rr_new_queue,
303 	_SI( .free_queue = ) rr_free_queue,
304 };
305 
306 
307 DECLARE_DNSCHED_MODULE(dn_rr, &rr_desc);
308