release/src-rt-6.x/linux/linux-2.6/net/sched/sch_prio.c

   1 /*
   2  * net/sched/sch_prio.c Simple 3-band priority "scheduler".
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  * Fixes:       19990609: J Hadi Salim <hadi@nortelnetworks.com>:
  11  *              Init --  EINVAL when opt undefined
  12  */
  13
  14 #include <linux/module.h>
  15 #include <asm/uaccess.h>
  16 #include <asm/system.h>
  17 #include <linux/bitops.h>
  18 #include <linux/types.h>
  19 #include <linux/kernel.h>
  20 #include <linux/string.h>
  21 #include <linux/mm.h>
  22 #include <linux/socket.h>
  23 #include <linux/sockios.h>
  24 #include <linux/in.h>
  25 #include <linux/errno.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/if_ether.h>
  28 #include <linux/inet.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/etherdevice.h>
  31 #include <linux/notifier.h>
  32 #include <net/ip.h>
  33 #include <net/route.h>
  34 #include <linux/skbuff.h>
  35 #include <net/netlink.h>
  36 #include <net/sock.h>
  37 #include <net/pkt_sched.h>
  38
  39
  40 struct prio_sched_data
  41 {
  42         int bands;
  43         struct tcf_proto *filter_list;
  44         u8  prio2band[TC_PRIO_MAX+1];
  45         struct Qdisc *queues[TCQ_PRIO_BANDS];
  46 };
  47
  48
  49 static struct Qdisc *
  50 prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
  51 {
  52         struct prio_sched_data *q = qdisc_priv(sch);
  53         u32 band = skb->priority;
  54         struct tcf_result res;
  55         int err;
  56
  57         *qerr = NET_XMIT_BYPASS;
  58         if (TC_H_MAJ(skb->priority) != sch->handle) {
  59                 err = tc_classify(skb, q->filter_list, &res);
  60 #ifdef CONFIG_NET_CLS_ACT
  61                 switch (tc_classify(skb, q->filter_list, &res)) {
  62                 case TC_ACT_STOLEN:
  63                 case TC_ACT_QUEUED:
  64                         *qerr = NET_XMIT_SUCCESS;
  65                 case TC_ACT_SHOT:
  66                         return NULL;
  67                 }
  68 #endif
  69                 if (!q->filter_list || err < 0) {
  70                         if (TC_H_MAJ(band))
  71                                 band = 0;
  72                         return q->queues[q->prio2band[band&TC_PRIO_MAX]];
  73                 }
  74                 band = res.classid;
  75         }
  76         band = TC_H_MIN(band) - 1;
  77         if (band >= q->bands)
  78                 return q->queues[q->prio2band[0]];
  79
  80         return q->queues[band];
  81 }
  82
  83 static int
  84 prio_enqueue(struct sk_buff *skb, struct Qdisc *sch)
  85 {
  86         struct Qdisc *qdisc;
  87         int ret;
  88
  89         qdisc = prio_classify(skb, sch, &ret);
  90 #ifdef CONFIG_NET_CLS_ACT
  91         if (qdisc == NULL) {
  92
  93                 if (ret == NET_XMIT_BYPASS)
  94                         sch->qstats.drops++;
  95                 kfree_skb(skb);
  96                 return ret;
  97         }
  98 #endif
  99
 100         if ((ret = qdisc->enqueue(skb, qdisc)) == NET_XMIT_SUCCESS) {
 101                 sch->bstats.bytes += skb->len;
 102                 sch->bstats.packets++;
 103                 sch->q.qlen++;
 104                 return NET_XMIT_SUCCESS;
 105         }
 106         sch->qstats.drops++;
 107         return ret;
 108 }
 109
 110
 111 static int
 112 prio_requeue(struct sk_buff *skb, struct Qdisc* sch)
 113 {
 114         struct Qdisc *qdisc;
 115         int ret;
 116
 117         qdisc = prio_classify(skb, sch, &ret);
 118 #ifdef CONFIG_NET_CLS_ACT
 119         if (qdisc == NULL) {
 120                 if (ret == NET_XMIT_BYPASS)
 121                         sch->qstats.drops++;
 122                 kfree_skb(skb);
 123                 return ret;
 124         }
 125 #endif
 126
 127         if ((ret = qdisc->ops->requeue(skb, qdisc)) == NET_XMIT_SUCCESS) {
 128                 sch->q.qlen++;
 129                 sch->qstats.requeues++;
 130                 return 0;
 131         }
 132         sch->qstats.drops++;
 133         return NET_XMIT_DROP;
 134 }
 135
 136
 137 static struct sk_buff *
 138 prio_dequeue(struct Qdisc* sch)
 139 {
 140         struct sk_buff *skb;
 141         struct prio_sched_data *q = qdisc_priv(sch);
 142         int prio;
 143         struct Qdisc *qdisc;
 144
 145         for (prio = 0; prio < q->bands; prio++) {
 146                 qdisc = q->queues[prio];
 147                 skb = qdisc->dequeue(qdisc);
 148                 if (skb) {
 149                         sch->q.qlen--;
 150                         return skb;
 151                 }
 152         }
 153         return NULL;
 154
 155 }
 156
 157 static unsigned int prio_drop(struct Qdisc* sch)
 158 {
 159         struct prio_sched_data *q = qdisc_priv(sch);
 160         int prio;
 161         unsigned int len;
 162         struct Qdisc *qdisc;
 163
 164         for (prio = q->bands-1; prio >= 0; prio--) {
 165                 qdisc = q->queues[prio];
 166                 if (qdisc->ops->drop && (len = qdisc->ops->drop(qdisc)) != 0) {
 167                         sch->q.qlen--;
 168                         return len;
 169                 }
 170         }
 171         return 0;
 172 }
 173
 174
 175 static void
 176 prio_reset(struct Qdisc* sch)
 177 {
 178         int prio;
 179         struct prio_sched_data *q = qdisc_priv(sch);
 180
 181         for (prio=0; prio<q->bands; prio++)
 182                 qdisc_reset(q->queues[prio]);
 183         sch->q.qlen = 0;
 184 }
 185
 186 static void
 187 prio_destroy(struct Qdisc* sch)
 188 {
 189         int prio;
 190         struct prio_sched_data *q = qdisc_priv(sch);
 191
 192         tcf_destroy_chain(q->filter_list);
 193         for (prio=0; prio<q->bands; prio++)
 194                 qdisc_destroy(q->queues[prio]);
 195 }
 196
 197 static int prio_tune(struct Qdisc *sch, struct rtattr *opt)
 198 {
 199         struct prio_sched_data *q = qdisc_priv(sch);
 200         struct tc_prio_qopt *qopt = RTA_DATA(opt);
 201         int i;
 202
 203         if (opt->rta_len < RTA_LENGTH(sizeof(*qopt)))
 204                 return -EINVAL;
 205         if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
 206                 return -EINVAL;
 207
 208         for (i=0; i<=TC_PRIO_MAX; i++) {
 209                 if (qopt->priomap[i] >= qopt->bands)
 210                         return -EINVAL;
 211         }
 212
 213         sch_tree_lock(sch);
 214         q->bands = qopt->bands;
 215         memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
 216
 217         for (i=q->bands; i<TCQ_PRIO_BANDS; i++) {
 218                 struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
 219                 if (child != &noop_qdisc) {
 220                         qdisc_tree_decrease_qlen(child, child->q.qlen);
 221                         qdisc_destroy(child);
 222                 }
 223         }
 224         sch_tree_unlock(sch);
 225
 226         for (i=0; i<q->bands; i++) {
 227                 if (q->queues[i] == &noop_qdisc) {
 228                         struct Qdisc *child;
 229                         child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops,
 230                                                   TC_H_MAKE(sch->handle, i + 1));
 231                         if (child) {
 232                                 sch_tree_lock(sch);
 233                                 child = xchg(&q->queues[i], child);
 234
 235                                 if (child != &noop_qdisc) {
 236                                         qdisc_tree_decrease_qlen(child,
 237                                                                  child->q.qlen);
 238                                         qdisc_destroy(child);
 239                                 }
 240                                 sch_tree_unlock(sch);
 241                         }
 242                 }
 243         }
 244         return 0;
 245 }
 246
 247 static int prio_init(struct Qdisc *sch, struct rtattr *opt)
 248 {
 249         struct prio_sched_data *q = qdisc_priv(sch);
 250         int i;
 251
 252         for (i=0; i<TCQ_PRIO_BANDS; i++)
 253                 q->queues[i] = &noop_qdisc;
 254
 255         if (opt == NULL) {
 256                 return -EINVAL;
 257         } else {
 258                 int err;
 259
 260                 if ((err= prio_tune(sch, opt)) != 0)
 261                         return err;
 262         }
 263         return 0;
 264 }
 265
 266 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
 267 {
 268         struct prio_sched_data *q = qdisc_priv(sch);
 269         unsigned char *b = skb_tail_pointer(skb);
 270         struct tc_prio_qopt opt;
 271
 272         opt.bands = q->bands;
 273         memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1);
 274         RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
 275         return skb->len;
 276
 277 rtattr_failure:
 278         nlmsg_trim(skb, b);
 279         return -1;
 280 }
 281
 282 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
 283                       struct Qdisc **old)
 284 {
 285         struct prio_sched_data *q = qdisc_priv(sch);
 286         unsigned long band = arg - 1;
 287
 288         if (band >= q->bands)
 289                 return -EINVAL;
 290
 291         if (new == NULL)
 292                 new = &noop_qdisc;
 293
 294         sch_tree_lock(sch);
 295         *old = q->queues[band];
 296         q->queues[band] = new;
 297         qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
 298         qdisc_reset(*old);
 299         sch_tree_unlock(sch);
 300
 301         return 0;
 302 }
 303
 304 static struct Qdisc *
 305 prio_leaf(struct Qdisc *sch, unsigned long arg)
 306 {
 307         struct prio_sched_data *q = qdisc_priv(sch);
 308         unsigned long band = arg - 1;
 309
 310         if (band >= q->bands)
 311                 return NULL;
 312
 313         return q->queues[band];
 314 }
 315
 316 static unsigned long prio_get(struct Qdisc *sch, u32 classid)
 317 {
 318         struct prio_sched_data *q = qdisc_priv(sch);
 319         unsigned long band = TC_H_MIN(classid);
 320
 321         if (band - 1 >= q->bands)
 322                 return 0;
 323         return band;
 324 }
 325
 326 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
 327 {
 328         return prio_get(sch, classid);
 329 }
 330
 331
 332 static void prio_put(struct Qdisc *q, unsigned long cl)
 333 {
 334         return;
 335 }
 336
 337 static int prio_change(struct Qdisc *sch, u32 handle, u32 parent, struct rtattr **tca, unsigned long *arg)
 338 {
 339         unsigned long cl = *arg;
 340         struct prio_sched_data *q = qdisc_priv(sch);
 341
 342         if (cl - 1 > q->bands)
 343                 return -ENOENT;
 344         return 0;
 345 }
 346
 347 static int prio_delete(struct Qdisc *sch, unsigned long cl)
 348 {
 349         struct prio_sched_data *q = qdisc_priv(sch);
 350         if (cl - 1 > q->bands)
 351                 return -ENOENT;
 352         return 0;
 353 }
 354
 355
 356 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
 357                            struct tcmsg *tcm)
 358 {
 359         struct prio_sched_data *q = qdisc_priv(sch);
 360
 361         if (cl - 1 > q->bands)
 362                 return -ENOENT;
 363         tcm->tcm_handle |= TC_H_MIN(cl);
 364         if (q->queues[cl-1])
 365                 tcm->tcm_info = q->queues[cl-1]->handle;
 366         return 0;
 367 }
 368
 369 static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 370                                  struct gnet_dump *d)
 371 {
 372         struct prio_sched_data *q = qdisc_priv(sch);
 373         struct Qdisc *cl_q;
 374
 375         cl_q = q->queues[cl - 1];
 376         if (gnet_stats_copy_basic(d, &cl_q->bstats) < 0 ||
 377             gnet_stats_copy_queue(d, &cl_q->qstats) < 0)
 378                 return -1;
 379
 380         return 0;
 381 }
 382
 383 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 384 {
 385         struct prio_sched_data *q = qdisc_priv(sch);
 386         int prio;
 387
 388         if (arg->stop)
 389                 return;
 390
 391         for (prio = 0; prio < q->bands; prio++) {
 392                 if (arg->count < arg->skip) {
 393                         arg->count++;
 394                         continue;
 395                 }
 396                 if (arg->fn(sch, prio+1, arg) < 0) {
 397                         arg->stop = 1;
 398                         break;
 399                 }
 400                 arg->count++;
 401         }
 402 }
 403
 404 static struct tcf_proto ** prio_find_tcf(struct Qdisc *sch, unsigned long cl)
 405 {
 406         struct prio_sched_data *q = qdisc_priv(sch);
 407
 408         if (cl)
 409                 return NULL;
 410         return &q->filter_list;
 411 }
 412
 413 static struct Qdisc_class_ops prio_class_ops = {
 414         .graft          =       prio_graft,
 415         .leaf           =       prio_leaf,
 416         .get            =       prio_get,
 417         .put            =       prio_put,
 418         .change         =       prio_change,
 419         .delete         =       prio_delete,
 420         .walk           =       prio_walk,
 421         .tcf_chain      =       prio_find_tcf,
 422         .bind_tcf       =       prio_bind,
 423         .unbind_tcf     =       prio_put,
 424         .dump           =       prio_dump_class,
 425         .dump_stats     =       prio_dump_class_stats,
 426 };
 427
 428 static struct Qdisc_ops prio_qdisc_ops = {
 429         .next           =       NULL,
 430         .cl_ops         =       &prio_class_ops,
 431         .id             =       "prio",
 432         .priv_size      =       sizeof(struct prio_sched_data),
 433         .enqueue        =       prio_enqueue,
 434         .dequeue        =       prio_dequeue,
 435         .requeue        =       prio_requeue,
 436         .drop           =       prio_drop,
 437         .init           =       prio_init,
 438         .reset          =       prio_reset,
 439         .destroy        =       prio_destroy,
 440         .change         =       prio_tune,
 441         .dump           =       prio_dump,
 442         .owner          =       THIS_MODULE,
 443 };
 444
 445 static int __init prio_module_init(void)
 446 {
 447         return register_qdisc(&prio_qdisc_ops);
 448 }
 449
 450 static void __exit prio_module_exit(void)
 451 {
 452         unregister_qdisc(&prio_qdisc_ops);
 453 }
 454
 455 module_init(prio_module_init)
 456 module_exit(prio_module_exit)
 457
 458 MODULE_LICENSE("GPL");