xref: /netbsd-src/sys/altq/altq_fifoq.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: altq_fifoq.c,v 1.17 2016/04/20 08:58:48 knakahara Exp $	*/
2 /*	$KAME: altq_fifoq.c,v 1.12 2003/07/10 12:07:48 kjc Exp $	*/
3 
4 /*
5  * Copyright (C) 1997-2002
6  *	Sony Computer Science Laboratories Inc.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY SONY CSL AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL SONY CSL OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __KERNEL_RCSID(0, "$NetBSD: altq_fifoq.c,v 1.17 2016/04/20 08:58:48 knakahara Exp $");
32 
33 #ifdef _KERNEL_OPT
34 #include "opt_altq.h"
35 #endif
36 
37 #ifdef ALTQ_FIFOQ  /* fifoq is enabled by ALTQ_FIFOQ option in opt_altq.h */
38 
39 /*
40  * FIFOQ is an altq sample implementation.  There will be little
41  * need to use FIFOQ as an alternative queueing scheme.
42  * But this code is provided as a template for those who want to
43  * write their own queueing schemes.
44  */
45 
46 #include <sys/param.h>
47 #include <sys/malloc.h>
48 #include <sys/mbuf.h>
49 #include <sys/socket.h>
50 #include <sys/sockio.h>
51 #include <sys/systm.h>
52 #include <sys/proc.h>
53 #include <sys/errno.h>
54 #include <sys/kernel.h>
55 #include <sys/kauth.h>
56 
57 #include <net/if.h>
58 #include <net/if_types.h>
59 #include <netinet/in.h>
60 
61 #include <altq/altq.h>
62 #include <altq/altq_conf.h>
63 #include <altq/altq_fifoq.h>
64 
65 #ifdef ALTQ3_COMPAT
66 
67 #define	FIFOQ_STATS	/* collect statistics */
68 
69 /* fifoq_list keeps all fifoq_state_t's allocated. */
70 static fifoq_state_t *fifoq_list = NULL;
71 
72 /* internal function prototypes */
73 static int		fifoq_enqueue(struct ifaltq *, struct mbuf *);
74 static struct mbuf 	*fifoq_dequeue(struct ifaltq *, int);
75 static int 		fifoq_detach(fifoq_state_t *);
76 static int		fifoq_request(struct ifaltq *, int, void *);
77 static void 		fifoq_purge(fifoq_state_t *);
78 
79 /*
80  * fifoq device interface
81  */
82 altqdev_decl(fifoq);
83 
84 int
85 fifoqopen(dev_t dev, int flag, int fmt,
86     struct lwp *l)
87 {
88 	/* everything will be done when the queueing scheme is attached. */
89 	return 0;
90 }
91 
92 /*
93  * there are 2 ways to act on close.
94  *   detach-all-on-close:
95  *	use for the daemon style approach.  if the daemon dies, all the
96  *	resource will be released.
97  *   no-action-on-close:
98  *	use for the command style approach.  (e.g.  fifoq on/off)
99  *
100  * note: close is called not on every close but when the last reference
101  *       is removed (only once with multiple simultaneous references.)
102  */
103 int
104 fifoqclose(dev_t dev, int flag, int fmt,
105     struct lwp *l)
106 {
107 	fifoq_state_t *q;
108 	int err, error = 0;
109 
110 	while ((q = fifoq_list) != NULL) {
111 		/* destroy all */
112 		err = fifoq_detach(q);
113 		if (err != 0 && error == 0)
114 			error = err;
115 	}
116 
117 	return error;
118 }
119 
120 int
121 fifoqioctl(dev_t dev, ioctlcmd_t cmd, void *addr, int flag,
122     struct lwp *l)
123 {
124 	fifoq_state_t *q;
125 	struct fifoq_interface *ifacep;
126 	struct ifnet *ifp;
127 	int	error = 0;
128 
129 	/* check super-user privilege */
130 	switch (cmd) {
131 	case FIFOQ_GETSTATS:
132 		break;
133 	default:
134 #if (__FreeBSD_version > 400000)
135 		if ((error = suser(p)) != 0)
136 			return (error);
137 #else
138 		if ((error = kauth_authorize_network(l->l_cred,
139 		    KAUTH_NETWORK_ALTQ, KAUTH_REQ_NETWORK_ALTQ_FIFOQ, NULL,
140 		    NULL, NULL)) != 0)
141 			return (error);
142 #endif
143 		break;
144 	}
145 
146 	switch (cmd) {
147 	case FIFOQ_ENABLE:
148 		ifacep = (struct fifoq_interface *)addr;
149 		if ((q = altq_lookup(ifacep->fifoq_ifname, ALTQT_FIFOQ))
150 		    == NULL) {
151 			error = EBADF;
152 			break;
153 		}
154 		error = altq_enable(q->q_ifq);
155 		break;
156 
157 	case FIFOQ_DISABLE:
158 		ifacep = (struct fifoq_interface *)addr;
159 		if ((q = altq_lookup(ifacep->fifoq_ifname, ALTQT_FIFOQ))
160 		    == NULL) {
161 			error = EBADF;
162 			break;
163 		}
164 		error = altq_disable(q->q_ifq);
165 		break;
166 
167 	case FIFOQ_IF_ATTACH:
168 		ifp = ifunit(((struct fifoq_interface *)addr)->fifoq_ifname);
169 		if (ifp == NULL) {
170 			error = ENXIO;
171 			break;
172 		}
173 
174 		/* allocate and initialize fifoq_state_t */
175 		q = malloc(sizeof(fifoq_state_t), M_DEVBUF, M_WAITOK|M_ZERO);
176 		if (q == NULL) {
177 			error = ENOMEM;
178 			break;
179 		}
180 
181 		q->q_ifq = &ifp->if_snd;
182 		q->q_head = q->q_tail = NULL;
183 		q->q_len = 0;
184 		q->q_limit = FIFOQ_LIMIT;
185 
186 		/*
187 		 * set FIFOQ to this ifnet structure.
188 		 */
189 		error = altq_attach(q->q_ifq, ALTQT_FIFOQ, q,
190 				    fifoq_enqueue, fifoq_dequeue, fifoq_request,
191 				    NULL, NULL);
192 		if (error) {
193 			free(q, M_DEVBUF);
194 			break;
195 		}
196 
197 		/* add this state to the fifoq list */
198 		q->q_next = fifoq_list;
199 		fifoq_list = q;
200 		break;
201 
202 	case FIFOQ_IF_DETACH:
203 		ifacep = (struct fifoq_interface *)addr;
204 		if ((q = altq_lookup(ifacep->fifoq_ifname, ALTQT_FIFOQ))
205 		    == NULL) {
206 			error = EBADF;
207 			break;
208 		}
209 		error = fifoq_detach(q);
210 		break;
211 
212 	case FIFOQ_GETSTATS:
213 		do {
214 			struct fifoq_getstats *q_stats;
215 
216 			q_stats = (struct fifoq_getstats *)addr;
217 			if ((q = altq_lookup(q_stats->iface.fifoq_ifname,
218 					     ALTQT_FIFOQ)) == NULL) {
219 				error = EBADF;
220 				break;
221 			}
222 
223 			q_stats->q_len		= q->q_len;
224 			q_stats->q_limit 	= q->q_limit;
225 			q_stats->xmit_cnt	= q->q_stats.xmit_cnt;
226 			q_stats->drop_cnt 	= q->q_stats.drop_cnt;
227 			q_stats->period   	= q->q_stats.period;
228 		} while (/*CONSTCOND*/ 0);
229 		break;
230 
231 	case FIFOQ_CONFIG:
232 		do {
233 			struct fifoq_conf *fc;
234 			int limit;
235 
236 			fc = (struct fifoq_conf *)addr;
237 			if ((q = altq_lookup(fc->iface.fifoq_ifname,
238 					     ALTQT_FIFOQ)) == NULL) {
239 				error = EBADF;
240 				break;
241 			}
242 			limit = fc->fifoq_limit;
243 			if (limit < 0)
244 				limit = 0;
245 			q->q_limit = limit;
246 			fc->fifoq_limit = limit;
247 		} while (/*CONSTCOND*/ 0);
248 		break;
249 
250 	default:
251 		error = EINVAL;
252 		break;
253 	}
254 	return error;
255 }
256 
257 /*
258  * fifoq support routines
259  */
260 
261 /*
262  * enqueue routine:
263  *
264  *	returns: 0 when successfully queued.
265  *		 ENOBUFS when drop occurs.
266  */
267 static int
268 fifoq_enqueue(struct ifaltq *ifq, struct mbuf *m)
269 {
270 	fifoq_state_t *q = (fifoq_state_t *)ifq->altq_disc;
271 
272 	/* if the queue is full, drop the incoming packet(drop-tail) */
273 	if (q->q_len >= q->q_limit) {
274 #ifdef FIFOQ_STATS
275 		PKTCNTR_ADD(&q->q_stats.drop_cnt, m_pktlen(m));
276 #endif
277 		m_freem(m);
278 		return (ENOBUFS);
279 	}
280 
281 	/* enqueue the packet at the taile of the queue */
282 	m->m_nextpkt = NULL;
283 	if (q->q_tail == NULL)
284 		q->q_head = m;
285 	else
286 		q->q_tail->m_nextpkt = m;
287 	q->q_tail = m;
288 	q->q_len++;
289 	ifq->ifq_len++;
290 	return 0;
291 }
292 
293 /*
294  * dequeue routine:
295  *	must be called in splnet.
296  *
297  *	returns: mbuf dequeued.
298  *		 NULL when no packet is available in the queue.
299  */
300 /*
301  * ALTDQ_PEEK is provided for drivers which need to know the next packet
302  * to send in advance.
303  * when ALTDQ_PEEK is specified, the next packet to be dequeued is
304  * returned without dequeueing the packet.
305  * when ALTDQ_DEQUEUE is called *immediately after* an ALTDQ_PEEK
306  * operation, the same packet should be returned.
307  */
308 static struct mbuf *
309 fifoq_dequeue(struct ifaltq *ifq, int op)
310 {
311 	fifoq_state_t *q = (fifoq_state_t *)ifq->altq_disc;
312 	struct mbuf *m = NULL;
313 
314 	if (op == ALTDQ_POLL)
315 		return (q->q_head);
316 
317 	if ((m = q->q_head) == NULL)
318 		return (NULL);
319 
320 	if ((q->q_head = m->m_nextpkt) == NULL)
321 		q->q_tail = NULL;
322 	m->m_nextpkt = NULL;
323 	q->q_len--;
324 	ifq->ifq_len--;
325 #ifdef FIFOQ_STATS
326 	PKTCNTR_ADD(&q->q_stats.xmit_cnt, m_pktlen(m));
327 	if (q->q_len == 0)
328 		q->q_stats.period++;
329 #endif
330 	return (m);
331 }
332 
333 static int
334 fifoq_request(struct ifaltq *ifq, int req, void *arg)
335 {
336 	fifoq_state_t *q = (fifoq_state_t *)ifq->altq_disc;
337 
338 	switch (req) {
339 	case ALTRQ_PURGE:
340 		fifoq_purge(q);
341 		break;
342 	}
343 	return (0);
344 }
345 
346 
347 static int
348 fifoq_detach(fifoq_state_t *q)
349 {
350 	fifoq_state_t *tmp;
351 	int error = 0;
352 
353 	if (ALTQ_IS_ENABLED(q->q_ifq))
354 		altq_disable(q->q_ifq);
355 
356 	fifoq_purge(q);
357 
358 	if ((error = altq_detach(q->q_ifq)))
359 		return (error);
360 
361 	if (fifoq_list == q)
362 		fifoq_list = q->q_next;
363 	else {
364 		for (tmp = fifoq_list; tmp != NULL; tmp = tmp->q_next)
365 			if (tmp->q_next == q) {
366 				tmp->q_next = q->q_next;
367 				break;
368 			}
369 		if (tmp == NULL)
370 			printf("fifoq_detach: no state in fifoq_list!\n");
371 	}
372 
373 	free(q, M_DEVBUF);
374 	return (error);
375 }
376 
377 /*
378  * fifoq_purge
379  * should be called in splnet or after disabling the fifoq.
380  */
381 static void
382 fifoq_purge(fifoq_state_t *q)
383 {
384 	struct mbuf *m;
385 
386 	while ((m = q->q_head) != NULL) {
387 		q->q_head = m->m_nextpkt;
388 		m_freem(m);
389 	}
390 	q->q_tail = NULL;
391 	q->q_len = 0;
392 	if (ALTQ_IS_ENABLED(q->q_ifq))
393 		q->q_ifq->ifq_len = 0;
394 }
395 
396 #ifdef KLD_MODULE
397 
398 static struct altqsw fifoq_sw =
399 	{"fifoq", fifoqopen, fifoqclose, fifoqioctl};
400 
401 ALTQ_MODULE(altq_fifoq, ALTQT_FIFOQ, &fifoq_sw);
402 
403 #endif /* KLD_MODULE */
404 
405 #endif /* ALTQ3_COMPAT */
406 #endif /* ALTQ_FIFOQ */
407