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altq_fifoq.c revision 1.4 
      1 /*	$NetBSD: altq_fifoq.c,v 1.4 2001/11/12 23:14:21 lukem Exp $	*/
      2 /*	$KAME: altq_fifoq.c,v 1.7 2000/12/14 08:12:45 thorpej Exp $	*/
      3 
      4 /*
      5  * Copyright (C) 1997-2000
      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 1.4 2001/11/12 23:14:21 lukem Exp $");
     32 
     33 #if defined(__FreeBSD__) || defined(__NetBSD__)
     34 #include "opt_altq.h"
     35 #endif /* __FreeBSD__ || __NetBSD__ */
     36 #ifdef ALTQ_FIFOQ  /* fifoq is enabled by ALTQ_FIFOQ option in opt_altq.h */
     37 
     38 /*
     39  * FIFOQ is an altq sample implementation.  There will be little
     40  * need to use FIFOQ as an alternative queueing scheme.
     41  * But this code is provided as a template for those who want to
     42  * write their own queueing schemes.
     43  */
     44 
     45 #include <sys/param.h>
     46 #include <sys/malloc.h>
     47 #include <sys/mbuf.h>
     48 #include <sys/socket.h>
     49 #include <sys/sockio.h>
     50 #include <sys/systm.h>
     51 #include <sys/proc.h>
     52 #include <sys/errno.h>
     53 #include <sys/kernel.h>
     54 
     55 #include <net/if.h>
     56 #include <net/if_types.h>
     57 #include <netinet/in.h>
     58 
     59 #include <altq/altq.h>
     60 #include <altq/altq_conf.h>
     61 #include <altq/altq_fifoq.h>
     62 
     63 #define	FIFOQ_STATS	/* collect statistics */
     64 
     65 /* fifoq_list keeps all fifoq_state_t's allocated. */
     66 static fifoq_state_t *fifoq_list = NULL;
     67 
     68 /* internal function prototypes */
     69 static int		fifoq_enqueue __P((struct ifaltq *, struct mbuf *,
     70 					   struct altq_pktattr *));
     71 static struct mbuf 	*fifoq_dequeue __P((struct ifaltq *, int));
     72 static int 		fifoq_detach __P((fifoq_state_t *));
     73 static int		fifoq_request __P((struct ifaltq *, int, void *));
     74 static void 		fifoq_purge __P((fifoq_state_t *));
     75 
     76 /*
     77  * fifoq device interface
     78  */
     79 altqdev_decl(fifoq);
     80 
     81 int
     82 fifoqopen(dev, flag, fmt, p)
     83 	dev_t dev;
     84 	int flag, fmt;
     85 	struct proc *p;
     86 {
     87 	/* everything will be done when the queueing scheme is attached. */
     88 	return 0;
     89 }
     90 
     91 /*
     92  * there are 2 ways to act on close.
     93  *   detach-all-on-close:
     94  *	use for the daemon style approach.  if the daemon dies, all the
     95  *	resource will be released.
     96  *   no-action-on-close:
     97  *	use for the command style approach.  (e.g.  fifoq on/off)
     98  *
     99  * note: close is called not on every close but when the last reference
    100  *       is removed (only once with multiple simultaneous references.)
    101  */
    102 int
    103 fifoqclose(dev, flag, fmt, p)
    104 	dev_t dev;
    105 	int flag, fmt;
    106 	struct proc *p;
    107 {
    108 	fifoq_state_t *q;
    109 	int err, error = 0;
    110 
    111 	while ((q = fifoq_list) != NULL) {
    112 		/* destroy all */
    113 		err = fifoq_detach(q);
    114 		if (err != 0 && error == 0)
    115 			error = err;
    116 	}
    117 
    118 	return error;
    119 }
    120 
    121 int
    122 fifoqioctl(dev, cmd, addr, flag, p)
    123 	dev_t dev;
    124 	ioctlcmd_t cmd;
    125 	caddr_t addr;
    126 	int flag;
    127 	struct proc *p;
    128 {
    129 	fifoq_state_t *q;
    130 	struct fifoq_interface *ifacep;
    131 	struct ifnet *ifp;
    132 	int	error = 0;
    133 
    134 	/* check super-user privilege */
    135 	switch (cmd) {
    136 	case FIFOQ_GETSTATS:
    137 		break;
    138 	default:
    139 #if (__FreeBSD_version > 400000)
    140 		if ((error = suser(p)) != 0)
    141 			return (error);
    142 #else
    143 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
    144 			return (error);
    145 #endif
    146 		break;
    147 	}
    148 
    149 	switch (cmd) {
    150 	case FIFOQ_ENABLE:
    151 		ifacep = (struct fifoq_interface *)addr;
    152 		if ((q = altq_lookup(ifacep->fifoq_ifname, ALTQT_FIFOQ))
    153 		    == NULL) {
    154 			error = EBADF;
    155 			break;
    156 		}
    157 		error = altq_enable(q->q_ifq);
    158 		break;
    159 
    160 	case FIFOQ_DISABLE:
    161 		ifacep = (struct fifoq_interface *)addr;
    162 		if ((q = altq_lookup(ifacep->fifoq_ifname, ALTQT_FIFOQ))
    163 		    == NULL) {
    164 			error = EBADF;
    165 			break;
    166 		}
    167 		error = altq_disable(q->q_ifq);
    168 		break;
    169 
    170 	case FIFOQ_IF_ATTACH:
    171 		ifp = ifunit(((struct fifoq_interface *)addr)->fifoq_ifname);
    172 		if (ifp == NULL) {
    173 			error = ENXIO;
    174 			break;
    175 		}
    176 
    177 		/* allocate and initialize fifoq_state_t */
    178 		MALLOC(q, fifoq_state_t *, sizeof(fifoq_state_t),
    179 		       M_DEVBUF, M_WAITOK);
    180 		if (q == NULL) {
    181 			error = ENOMEM;
    182 			break;
    183 		}
    184 		bzero(q, sizeof(fifoq_state_t));
    185 
    186 		q->q_ifq = &ifp->if_snd;
    187 		q->q_head = q->q_tail = NULL;
    188 		q->q_len = 0;
    189 		q->q_limit = FIFOQ_LIMIT;
    190 
    191 		/*
    192 		 * set FIFOQ to this ifnet structure.
    193 		 */
    194 		error = altq_attach(q->q_ifq, ALTQT_FIFOQ, q,
    195 				    fifoq_enqueue, fifoq_dequeue, fifoq_request,
    196 				    NULL, NULL);
    197 		if (error) {
    198 			FREE(q, M_DEVBUF);
    199 			break;
    200 		}
    201 
    202 		/* add this state to the fifoq list */
    203 		q->q_next = fifoq_list;
    204 		fifoq_list = q;
    205 		break;
    206 
    207 	case FIFOQ_IF_DETACH:
    208 		ifacep = (struct fifoq_interface *)addr;
    209 		if ((q = altq_lookup(ifacep->fifoq_ifname, ALTQT_FIFOQ))
    210 		    == NULL) {
    211 			error = EBADF;
    212 			break;
    213 		}
    214 		error = fifoq_detach(q);
    215 		break;
    216 
    217 	case FIFOQ_GETSTATS:
    218 		do {
    219 			struct fifoq_getstats *q_stats;
    220 
    221 			q_stats = (struct fifoq_getstats *)addr;
    222 			if ((q = altq_lookup(q_stats->iface.fifoq_ifname,
    223 					     ALTQT_FIFOQ)) == NULL) {
    224 				error = EBADF;
    225 				break;
    226 			}
    227 
    228 			q_stats->q_len		= q->q_len;
    229 			q_stats->q_limit 	= q->q_limit;
    230 			q_stats->xmit_cnt	= q->q_stats.xmit_cnt;
    231 			q_stats->drop_cnt 	= q->q_stats.drop_cnt;
    232 			q_stats->period   	= q->q_stats.period;
    233 		} while (0);
    234 		break;
    235 
    236 	case FIFOQ_CONFIG:
    237 		do {
    238 			struct fifoq_conf *fc;
    239 			int limit;
    240 
    241 			fc = (struct fifoq_conf *)addr;
    242 			if ((q = altq_lookup(fc->iface.fifoq_ifname,
    243 					     ALTQT_FIFOQ)) == NULL) {
    244 				error = EBADF;
    245 				break;
    246 			}
    247 			limit = fc->fifoq_limit;
    248 			if (limit < 0)
    249 				limit = 0;
    250 			q->q_limit = limit;
    251 			fc->fifoq_limit = limit;
    252 		} while (0);
    253 		break;
    254 
    255 	default:
    256 		error = EINVAL;
    257 		break;
    258 	}
    259 	return error;
    260 }
    261 
    262 /*
    263  * fifoq support routines
    264  */
    265 
    266 /*
    267  * enqueue routine:
    268  *
    269  *	returns: 0 when successfully queued.
    270  *		 ENOBUFS when drop occurs.
    271  */
    272 static int
    273 fifoq_enqueue(ifq, m, pktattr)
    274 	struct ifaltq *ifq;
    275 	struct mbuf *m;
    276 	struct altq_pktattr *pktattr;
    277 {
    278 	fifoq_state_t *q = (fifoq_state_t *)ifq->altq_disc;
    279 
    280 	/* if the queue is full, drop the incoming packet(drop-tail) */
    281 	if (q->q_len >= q->q_limit) {
    282 #ifdef FIFOQ_STATS
    283 		PKTCNTR_ADD(&q->q_stats.drop_cnt, m_pktlen(m));
    284 #endif
    285 		m_freem(m);
    286 		return (ENOBUFS);
    287 	}
    288 
    289 	/* enqueue the packet at the taile of the queue */
    290 	m->m_nextpkt = NULL;
    291 	if (q->q_tail == NULL)
    292 		q->q_head = m;
    293 	else
    294 		q->q_tail->m_nextpkt = m;
    295 	q->q_tail = m;
    296 	q->q_len++;
    297 	ifq->ifq_len++;
    298 	return 0;
    299 }
    300 
    301 /*
    302  * dequeue routine:
    303  *	must be called in splnet.
    304  *
    305  *	returns: mbuf dequeued.
    306  *		 NULL when no packet is available in the queue.
    307  */
    308 /*
    309  * ALTDQ_PEEK is provided for drivers which need to know the next packet
    310  * to send in advance.
    311  * when ALTDQ_PEEK is specified, the next packet to be dequeued is
    312  * returned without dequeueing the packet.
    313  * when ALTDQ_DEQUEUE is called *immediately after* an ALTDQ_PEEK
    314  * operation, the same packet should be returned.
    315  */
    316 static struct mbuf *
    317 fifoq_dequeue(ifq, op)
    318 	struct ifaltq *ifq;
    319 	int op;
    320 {
    321 	fifoq_state_t *q = (fifoq_state_t *)ifq->altq_disc;
    322 	struct mbuf *m = NULL;
    323 
    324 	if (op == ALTDQ_POLL)
    325 		return (q->q_head);
    326 
    327 	if ((m = q->q_head) == NULL)
    328 		return (NULL);
    329 
    330 	if ((q->q_head = m->m_nextpkt) == NULL)
    331 		q->q_tail = NULL;
    332 	m->m_nextpkt = NULL;
    333 	q->q_len--;
    334 	ifq->ifq_len--;
    335 #ifdef FIFOQ_STATS
    336 	PKTCNTR_ADD(&q->q_stats.xmit_cnt, m_pktlen(m));
    337 	if (q->q_len == 0)
    338 		q->q_stats.period++;
    339 #endif
    340 	return (m);
    341 }
    342 
    343 static int
    344 fifoq_request(ifq, req, arg)
    345 	struct ifaltq *ifq;
    346 	int req;
    347 	void *arg;
    348 {
    349 	fifoq_state_t *q = (fifoq_state_t *)ifq->altq_disc;
    350 
    351 	switch (req) {
    352 	case ALTRQ_PURGE:
    353 		fifoq_purge(q);
    354 		break;
    355 	}
    356 	return (0);
    357 }
    358 
    359 
    360 static int fifoq_detach(q)
    361 	fifoq_state_t *q;
    362 {
    363 	fifoq_state_t *tmp;
    364 	int error = 0;
    365 
    366 	if (ALTQ_IS_ENABLED(q->q_ifq))
    367 		altq_disable(q->q_ifq);
    368 
    369 	fifoq_purge(q);
    370 
    371 	if ((error = altq_detach(q->q_ifq)))
    372 		return (error);
    373 
    374 	if (fifoq_list == q)
    375 		fifoq_list = q->q_next;
    376 	else {
    377 		for (tmp = fifoq_list; tmp != NULL; tmp = tmp->q_next)
    378 			if (tmp->q_next == q) {
    379 				tmp->q_next = q->q_next;
    380 				break;
    381 			}
    382 		if (tmp == NULL)
    383 			printf("fifoq_detach: no state in fifoq_list!\n");
    384 	}
    385 
    386 	FREE(q, M_DEVBUF);
    387 	return (error);
    388 }
    389 
    390 /*
    391  * fifoq_purge
    392  * should be called in splnet or after disabling the fifoq.
    393  */
    394 static void fifoq_purge(q)
    395 	fifoq_state_t *q;
    396 {
    397 	struct mbuf *m;
    398 
    399 	while ((m = q->q_head) != NULL) {
    400 		q->q_head = m->m_nextpkt;
    401 		m_freem(m);
    402 	}
    403 	q->q_tail = NULL;
    404 	q->q_len = 0;
    405 	if (ALTQ_IS_ENABLED(q->q_ifq))
    406 		q->q_ifq->ifq_len = 0;
    407 }
    408 
    409 #ifdef KLD_MODULE
    410 
    411 static struct altqsw fifoq_sw =
    412 	{"fifoq", fifoqopen, fifoqclose, fifoqioctl};
    413 
    414 ALTQ_MODULE(altq_fifoq, ALTQT_FIFOQ, &fifoq_sw);
    415 
    416 #endif /* KLD_MODULE */
    417 
    418 #endif /* ALTQ_FIFOQ */
    419