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altq_fifoq.c revision 1.9 
      1 /*	$NetBSD: altq_fifoq.c,v 1.9 2006/05/14 21:24:49 elad 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 1.9 2006/05/14 21:24:49 elad 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 /* fifoq_list keeps all fifoq_state_t's allocated. */
     64 static fifoq_state_t *fifoq_list = NULL;
     65 
     66 /* internal function prototypes */
     67 static int		fifoq_enqueue __P((struct ifaltq *, struct mbuf *,
     68 					   struct altq_pktattr *));
     69 static struct mbuf 	*fifoq_dequeue __P((struct ifaltq *, int));
     70 static int 		fifoq_detach __P((fifoq_state_t *));
     71 static int		fifoq_request __P((struct ifaltq *, int, void *));
     72 static void 		fifoq_purge __P((fifoq_state_t *));
     73 
     74 /*
     75  * fifoq device interface
     76  */
     77 altqdev_decl(fifoq);
     78 
     79 int
     80 fifoqopen(dev, flag, fmt, l)
     81 	dev_t dev;
     82 	int flag, fmt;
     83 	struct lwp *l;
     84 {
     85 	/* everything will be done when the queueing scheme is attached. */
     86 	return 0;
     87 }
     88 
     89 /*
     90  * there are 2 ways to act on close.
     91  *   detach-all-on-close:
     92  *	use for the daemon style approach.  if the daemon dies, all the
     93  *	resource will be released.
     94  *   no-action-on-close:
     95  *	use for the command style approach.  (e.g.  fifoq on/off)
     96  *
     97  * note: close is called not on every close but when the last reference
     98  *       is removed (only once with multiple simultaneous references.)
     99  */
    100 int
    101 fifoqclose(dev, flag, fmt, l)
    102 	dev_t dev;
    103 	int flag, fmt;
    104 	struct lwp *l;
    105 {
    106 	fifoq_state_t *q;
    107 	int err, error = 0;
    108 
    109 	while ((q = fifoq_list) != NULL) {
    110 		/* destroy all */
    111 		err = fifoq_detach(q);
    112 		if (err != 0 && error == 0)
    113 			error = err;
    114 	}
    115 
    116 	return error;
    117 }
    118 
    119 int
    120 fifoqioctl(dev, cmd, addr, flag, l)
    121 	dev_t dev;
    122 	ioctlcmd_t cmd;
    123 	caddr_t addr;
    124 	int flag;
    125 	struct lwp *l;
    126 {
    127 	fifoq_state_t *q;
    128 	struct fifoq_interface *ifacep;
    129 	struct ifnet *ifp;
    130 	struct proc *p = l->l_proc;
    131 	int	error = 0;
    132 
    133 	/* check super-user privilege */
    134 	switch (cmd) {
    135 	case FIFOQ_GETSTATS:
    136 		break;
    137 	default:
    138 #if (__FreeBSD_version > 400000)
    139 		if ((error = suser(p)) != 0)
    140 			return (error);
    141 #else
    142 		if ((error = kauth_authorize_generic(p->p_cred,
    143 					       KAUTH_GENERIC_ISSUSER,
    144 					       &p->p_acflag)) != 0)
    145 			return (error);
    146 #endif
    147 		break;
    148 	}
    149 
    150 	switch (cmd) {
    151 	case FIFOQ_ENABLE:
    152 		ifacep = (struct fifoq_interface *)addr;
    153 		if ((q = altq_lookup(ifacep->fifoq_ifname, ALTQT_FIFOQ))
    154 		    == NULL) {
    155 			error = EBADF;
    156 			break;
    157 		}
    158 		error = altq_enable(q->q_ifq);
    159 		break;
    160 
    161 	case FIFOQ_DISABLE:
    162 		ifacep = (struct fifoq_interface *)addr;
    163 		if ((q = altq_lookup(ifacep->fifoq_ifname, ALTQT_FIFOQ))
    164 		    == NULL) {
    165 			error = EBADF;
    166 			break;
    167 		}
    168 		error = altq_disable(q->q_ifq);
    169 		break;
    170 
    171 	case FIFOQ_IF_ATTACH:
    172 		ifp = ifunit(((struct fifoq_interface *)addr)->fifoq_ifname);
    173 		if (ifp == NULL) {
    174 			error = ENXIO;
    175 			break;
    176 		}
    177 
    178 		/* allocate and initialize fifoq_state_t */
    179 		q = malloc(sizeof(fifoq_state_t), M_DEVBUF, M_WAITOK|M_ZERO);
    180 		if (q == NULL) {
    181 			error = ENOMEM;
    182 			break;
    183 		}
    184 
    185 		q->q_ifq = &ifp->if_snd;
    186 		q->q_head = q->q_tail = NULL;
    187 		q->q_len = 0;
    188 		q->q_limit = FIFOQ_LIMIT;
    189 
    190 		/*
    191 		 * set FIFOQ to this ifnet structure.
    192 		 */
    193 		error = altq_attach(q->q_ifq, ALTQT_FIFOQ, q,
    194 				    fifoq_enqueue, fifoq_dequeue, fifoq_request,
    195 				    NULL, NULL);
    196 		if (error) {
    197 			free(q, M_DEVBUF);
    198 			break;
    199 		}
    200 
    201 		/* add this state to the fifoq list */
    202 		q->q_next = fifoq_list;
    203 		fifoq_list = q;
    204 		break;
    205 
    206 	case FIFOQ_IF_DETACH:
    207 		ifacep = (struct fifoq_interface *)addr;
    208 		if ((q = altq_lookup(ifacep->fifoq_ifname, ALTQT_FIFOQ))
    209 		    == NULL) {
    210 			error = EBADF;
    211 			break;
    212 		}
    213 		error = fifoq_detach(q);
    214 		break;
    215 
    216 	case FIFOQ_GETSTATS:
    217 		do {
    218 			struct fifoq_getstats *q_stats;
    219 
    220 			q_stats = (struct fifoq_getstats *)addr;
    221 			if ((q = altq_lookup(q_stats->iface.fifoq_ifname,
    222 					     ALTQT_FIFOQ)) == NULL) {
    223 				error = EBADF;
    224 				break;
    225 			}
    226 
    227 			q_stats->q_len		= q->q_len;
    228 			q_stats->q_limit 	= q->q_limit;
    229 			q_stats->xmit_cnt	= q->q_stats.xmit_cnt;
    230 			q_stats->drop_cnt 	= q->q_stats.drop_cnt;
    231 			q_stats->period   	= q->q_stats.period;
    232 		} while (0);
    233 		break;
    234 
    235 	case FIFOQ_CONFIG:
    236 		do {
    237 			struct fifoq_conf *fc;
    238 			int limit;
    239 
    240 			fc = (struct fifoq_conf *)addr;
    241 			if ((q = altq_lookup(fc->iface.fifoq_ifname,
    242 					     ALTQT_FIFOQ)) == NULL) {
    243 				error = EBADF;
    244 				break;
    245 			}
    246 			limit = fc->fifoq_limit;
    247 			if (limit < 0)
    248 				limit = 0;
    249 			q->q_limit = limit;
    250 			fc->fifoq_limit = limit;
    251 		} while (0);
    252 		break;
    253 
    254 	default:
    255 		error = EINVAL;
    256 		break;
    257 	}
    258 	return error;
    259 }
    260 
    261 /*
    262  * fifoq support routines
    263  */
    264 
    265 /*
    266  * enqueue routine:
    267  *
    268  *	returns: 0 when successfully queued.
    269  *		 ENOBUFS when drop occurs.
    270  */
    271 static int
    272 fifoq_enqueue(ifq, m, pktattr)
    273 	struct ifaltq *ifq;
    274 	struct mbuf *m;
    275 	struct altq_pktattr *pktattr;
    276 {
    277 	fifoq_state_t *q = (fifoq_state_t *)ifq->altq_disc;
    278 
    279 	/* if the queue is full, drop the incoming packet(drop-tail) */
    280 	if (q->q_len >= q->q_limit) {
    281 #ifdef FIFOQ_STATS
    282 		PKTCNTR_ADD(&q->q_stats.drop_cnt, m_pktlen(m));
    283 #endif
    284 		m_freem(m);
    285 		return (ENOBUFS);
    286 	}
    287 
    288 	/* enqueue the packet at the taile of the queue */
    289 	m->m_nextpkt = NULL;
    290 	if (q->q_tail == NULL)
    291 		q->q_head = m;
    292 	else
    293 		q->q_tail->m_nextpkt = m;
    294 	q->q_tail = m;
    295 	q->q_len++;
    296 	ifq->ifq_len++;
    297 	return 0;
    298 }
    299 
    300 /*
    301  * dequeue routine:
    302  *	must be called in splnet.
    303  *
    304  *	returns: mbuf dequeued.
    305  *		 NULL when no packet is available in the queue.
    306  */
    307 /*
    308  * ALTDQ_PEEK is provided for drivers which need to know the next packet
    309  * to send in advance.
    310  * when ALTDQ_PEEK is specified, the next packet to be dequeued is
    311  * returned without dequeueing the packet.
    312  * when ALTDQ_DEQUEUE is called *immediately after* an ALTDQ_PEEK
    313  * operation, the same packet should be returned.
    314  */
    315 static struct mbuf *
    316 fifoq_dequeue(ifq, op)
    317 	struct ifaltq *ifq;
    318 	int op;
    319 {
    320 	fifoq_state_t *q = (fifoq_state_t *)ifq->altq_disc;
    321 	struct mbuf *m = NULL;
    322 
    323 	if (op == ALTDQ_POLL)
    324 		return (q->q_head);
    325 
    326 	if ((m = q->q_head) == NULL)
    327 		return (NULL);
    328 
    329 	if ((q->q_head = m->m_nextpkt) == NULL)
    330 		q->q_tail = NULL;
    331 	m->m_nextpkt = NULL;
    332 	q->q_len--;
    333 	ifq->ifq_len--;
    334 #ifdef FIFOQ_STATS
    335 	PKTCNTR_ADD(&q->q_stats.xmit_cnt, m_pktlen(m));
    336 	if (q->q_len == 0)
    337 		q->q_stats.period++;
    338 #endif
    339 	return (m);
    340 }
    341 
    342 static int
    343 fifoq_request(ifq, req, arg)
    344 	struct ifaltq *ifq;
    345 	int req;
    346 	void *arg;
    347 {
    348 	fifoq_state_t *q = (fifoq_state_t *)ifq->altq_disc;
    349 
    350 	switch (req) {
    351 	case ALTRQ_PURGE:
    352 		fifoq_purge(q);
    353 		break;
    354 	}
    355 	return (0);
    356 }
    357 
    358 
    359 static int fifoq_detach(q)
    360 	fifoq_state_t *q;
    361 {
    362 	fifoq_state_t *tmp;
    363 	int error = 0;
    364 
    365 	if (ALTQ_IS_ENABLED(q->q_ifq))
    366 		altq_disable(q->q_ifq);
    367 
    368 	fifoq_purge(q);
    369 
    370 	if ((error = altq_detach(q->q_ifq)))
    371 		return (error);
    372 
    373 	if (fifoq_list == q)
    374 		fifoq_list = q->q_next;
    375 	else {
    376 		for (tmp = fifoq_list; tmp != NULL; tmp = tmp->q_next)
    377 			if (tmp->q_next == q) {
    378 				tmp->q_next = q->q_next;
    379 				break;
    380 			}
    381 		if (tmp == NULL)
    382 			printf("fifoq_detach: no state in fifoq_list!\n");
    383 	}
    384 
    385 	free(q, M_DEVBUF);
    386 	return (error);
    387 }
    388 
    389 /*
    390  * fifoq_purge
    391  * should be called in splnet or after disabling the fifoq.
    392  */
    393 static void fifoq_purge(q)
    394 	fifoq_state_t *q;
    395 {
    396 	struct mbuf *m;
    397 
    398 	while ((m = q->q_head) != NULL) {
    399 		q->q_head = m->m_nextpkt;
    400 		m_freem(m);
    401 	}
    402 	q->q_tail = NULL;
    403 	q->q_len = 0;
    404 	if (ALTQ_IS_ENABLED(q->q_ifq))
    405 		q->q_ifq->ifq_len = 0;
    406 }
    407 
    408 #ifdef KLD_MODULE
    409 
    410 static struct altqsw fifoq_sw =
    411 	{"fifoq", fifoqopen, fifoqclose, fifoqioctl};
    412 
    413 ALTQ_MODULE(altq_fifoq, ALTQT_FIFOQ, &fifoq_sw);
    414 
    415 #endif /* KLD_MODULE */
    416 
    417 #endif /* ALTQ_FIFOQ */
    418