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altq_fifoq.c revision 1.11 
      1 /*	$NetBSD: altq_fifoq.c,v 1.11 2006/07/21 16:48:45 ad 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 1.11 2006/07/21 16:48:45 ad 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 #include <sys/kauth.h>
     55 
     56 #include <net/if.h>
     57 #include <net/if_types.h>
     58 #include <netinet/in.h>
     59 
     60 #include <altq/altq.h>
     61 #include <altq/altq_conf.h>
     62 #include <altq/altq_fifoq.h>
     63 
     64 /* fifoq_list keeps all fifoq_state_t's allocated. */
     65 static fifoq_state_t *fifoq_list = NULL;
     66 
     67 /* internal function prototypes */
     68 static int		fifoq_enqueue __P((struct ifaltq *, struct mbuf *,
     69 					   struct altq_pktattr *));
     70 static struct mbuf 	*fifoq_dequeue __P((struct ifaltq *, int));
     71 static int 		fifoq_detach __P((fifoq_state_t *));
     72 static int		fifoq_request __P((struct ifaltq *, int, void *));
     73 static void 		fifoq_purge __P((fifoq_state_t *));
     74 
     75 /*
     76  * fifoq device interface
     77  */
     78 altqdev_decl(fifoq);
     79 
     80 int
     81 fifoqopen(dev, flag, fmt, l)
     82 	dev_t dev;
     83 	int flag, fmt;
     84 	struct lwp *l;
     85 {
     86 	/* everything will be done when the queueing scheme is attached. */
     87 	return 0;
     88 }
     89 
     90 /*
     91  * there are 2 ways to act on close.
     92  *   detach-all-on-close:
     93  *	use for the daemon style approach.  if the daemon dies, all the
     94  *	resource will be released.
     95  *   no-action-on-close:
     96  *	use for the command style approach.  (e.g.  fifoq on/off)
     97  *
     98  * note: close is called not on every close but when the last reference
     99  *       is removed (only once with multiple simultaneous references.)
    100  */
    101 int
    102 fifoqclose(dev, flag, fmt, l)
    103 	dev_t dev;
    104 	int flag, 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, cmd, addr, flag, l)
    122 	dev_t dev;
    123 	ioctlcmd_t cmd;
    124 	caddr_t addr;
    125 	int flag;
    126 	struct lwp *l;
    127 {
    128 	fifoq_state_t *q;
    129 	struct fifoq_interface *ifacep;
    130 	struct ifnet *ifp;
    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(l->l_cred,
    143 		    KAUTH_GENERIC_ISSUSER, &l->l_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 		q = malloc(sizeof(fifoq_state_t), M_DEVBUF, M_WAITOK|M_ZERO);
    179 		if (q == NULL) {
    180 			error = ENOMEM;
    181 			break;
    182 		}
    183 
    184 		q->q_ifq = &ifp->if_snd;
    185 		q->q_head = q->q_tail = NULL;
    186 		q->q_len = 0;
    187 		q->q_limit = FIFOQ_LIMIT;
    188 
    189 		/*
    190 		 * set FIFOQ to this ifnet structure.
    191 		 */
    192 		error = altq_attach(q->q_ifq, ALTQT_FIFOQ, q,
    193 				    fifoq_enqueue, fifoq_dequeue, fifoq_request,
    194 				    NULL, NULL);
    195 		if (error) {
    196 			free(q, M_DEVBUF);
    197 			break;
    198 		}
    199 
    200 		/* add this state to the fifoq list */
    201 		q->q_next = fifoq_list;
    202 		fifoq_list = q;
    203 		break;
    204 
    205 	case FIFOQ_IF_DETACH:
    206 		ifacep = (struct fifoq_interface *)addr;
    207 		if ((q = altq_lookup(ifacep->fifoq_ifname, ALTQT_FIFOQ))
    208 		    == NULL) {
    209 			error = EBADF;
    210 			break;
    211 		}
    212 		error = fifoq_detach(q);
    213 		break;
    214 
    215 	case FIFOQ_GETSTATS:
    216 		do {
    217 			struct fifoq_getstats *q_stats;
    218 
    219 			q_stats = (struct fifoq_getstats *)addr;
    220 			if ((q = altq_lookup(q_stats->iface.fifoq_ifname,
    221 					     ALTQT_FIFOQ)) == NULL) {
    222 				error = EBADF;
    223 				break;
    224 			}
    225 
    226 			q_stats->q_len		= q->q_len;
    227 			q_stats->q_limit 	= q->q_limit;
    228 			q_stats->xmit_cnt	= q->q_stats.xmit_cnt;
    229 			q_stats->drop_cnt 	= q->q_stats.drop_cnt;
    230 			q_stats->period   	= q->q_stats.period;
    231 		} while (0);
    232 		break;
    233 
    234 	case FIFOQ_CONFIG:
    235 		do {
    236 			struct fifoq_conf *fc;
    237 			int limit;
    238 
    239 			fc = (struct fifoq_conf *)addr;
    240 			if ((q = altq_lookup(fc->iface.fifoq_ifname,
    241 					     ALTQT_FIFOQ)) == NULL) {
    242 				error = EBADF;
    243 				break;
    244 			}
    245 			limit = fc->fifoq_limit;
    246 			if (limit < 0)
    247 				limit = 0;
    248 			q->q_limit = limit;
    249 			fc->fifoq_limit = limit;
    250 		} while (0);
    251 		break;
    252 
    253 	default:
    254 		error = EINVAL;
    255 		break;
    256 	}
    257 	return error;
    258 }
    259 
    260 /*
    261  * fifoq support routines
    262  */
    263 
    264 /*
    265  * enqueue routine:
    266  *
    267  *	returns: 0 when successfully queued.
    268  *		 ENOBUFS when drop occurs.
    269  */
    270 static int
    271 fifoq_enqueue(ifq, m, pktattr)
    272 	struct ifaltq *ifq;
    273 	struct mbuf *m;
    274 	struct altq_pktattr *pktattr;
    275 {
    276 	fifoq_state_t *q = (fifoq_state_t *)ifq->altq_disc;
    277 
    278 	/* if the queue is full, drop the incoming packet(drop-tail) */
    279 	if (q->q_len >= q->q_limit) {
    280 #ifdef FIFOQ_STATS
    281 		PKTCNTR_ADD(&q->q_stats.drop_cnt, m_pktlen(m));
    282 #endif
    283 		m_freem(m);
    284 		return (ENOBUFS);
    285 	}
    286 
    287 	/* enqueue the packet at the taile of the queue */
    288 	m->m_nextpkt = NULL;
    289 	if (q->q_tail == NULL)
    290 		q->q_head = m;
    291 	else
    292 		q->q_tail->m_nextpkt = m;
    293 	q->q_tail = m;
    294 	q->q_len++;
    295 	ifq->ifq_len++;
    296 	return 0;
    297 }
    298 
    299 /*
    300  * dequeue routine:
    301  *	must be called in splnet.
    302  *
    303  *	returns: mbuf dequeued.
    304  *		 NULL when no packet is available in the queue.
    305  */
    306 /*
    307  * ALTDQ_PEEK is provided for drivers which need to know the next packet
    308  * to send in advance.
    309  * when ALTDQ_PEEK is specified, the next packet to be dequeued is
    310  * returned without dequeueing the packet.
    311  * when ALTDQ_DEQUEUE is called *immediately after* an ALTDQ_PEEK
    312  * operation, the same packet should be returned.
    313  */
    314 static struct mbuf *
    315 fifoq_dequeue(ifq, op)
    316 	struct ifaltq *ifq;
    317 	int op;
    318 {
    319 	fifoq_state_t *q = (fifoq_state_t *)ifq->altq_disc;
    320 	struct mbuf *m = NULL;
    321 
    322 	if (op == ALTDQ_POLL)
    323 		return (q->q_head);
    324 
    325 	if ((m = q->q_head) == NULL)
    326 		return (NULL);
    327 
    328 	if ((q->q_head = m->m_nextpkt) == NULL)
    329 		q->q_tail = NULL;
    330 	m->m_nextpkt = NULL;
    331 	q->q_len--;
    332 	ifq->ifq_len--;
    333 #ifdef FIFOQ_STATS
    334 	PKTCNTR_ADD(&q->q_stats.xmit_cnt, m_pktlen(m));
    335 	if (q->q_len == 0)
    336 		q->q_stats.period++;
    337 #endif
    338 	return (m);
    339 }
    340 
    341 static int
    342 fifoq_request(ifq, req, arg)
    343 	struct ifaltq *ifq;
    344 	int req;
    345 	void *arg;
    346 {
    347 	fifoq_state_t *q = (fifoq_state_t *)ifq->altq_disc;
    348 
    349 	switch (req) {
    350 	case ALTRQ_PURGE:
    351 		fifoq_purge(q);
    352 		break;
    353 	}
    354 	return (0);
    355 }
    356 
    357 
    358 static int fifoq_detach(q)
    359 	fifoq_state_t *q;
    360 {
    361 	fifoq_state_t *tmp;
    362 	int error = 0;
    363 
    364 	if (ALTQ_IS_ENABLED(q->q_ifq))
    365 		altq_disable(q->q_ifq);
    366 
    367 	fifoq_purge(q);
    368 
    369 	if ((error = altq_detach(q->q_ifq)))
    370 		return (error);
    371 
    372 	if (fifoq_list == q)
    373 		fifoq_list = q->q_next;
    374 	else {
    375 		for (tmp = fifoq_list; tmp != NULL; tmp = tmp->q_next)
    376 			if (tmp->q_next == q) {
    377 				tmp->q_next = q->q_next;
    378 				break;
    379 			}
    380 		if (tmp == NULL)
    381 			printf("fifoq_detach: no state in fifoq_list!\n");
    382 	}
    383 
    384 	free(q, M_DEVBUF);
    385 	return (error);
    386 }
    387 
    388 /*
    389  * fifoq_purge
    390  * should be called in splnet or after disabling the fifoq.
    391  */
    392 static void fifoq_purge(q)
    393 	fifoq_state_t *q;
    394 {
    395 	struct mbuf *m;
    396 
    397 	while ((m = q->q_head) != NULL) {
    398 		q->q_head = m->m_nextpkt;
    399 		m_freem(m);
    400 	}
    401 	q->q_tail = NULL;
    402 	q->q_len = 0;
    403 	if (ALTQ_IS_ENABLED(q->q_ifq))
    404 		q->q_ifq->ifq_len = 0;
    405 }
    406 
    407 #ifdef KLD_MODULE
    408 
    409 static struct altqsw fifoq_sw =
    410 	{"fifoq", fifoqopen, fifoqclose, fifoqioctl};
    411 
    412 ALTQ_MODULE(altq_fifoq, ALTQT_FIFOQ, &fifoq_sw);
    413 
    414 #endif /* KLD_MODULE */
    415 
    416 #endif /* ALTQ_FIFOQ */
    417