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/config.h>
  15 #include <linux/module.h>
  16 #include <asm/uaccess.h>
  17 #include <asm/system.h>
  18 #include <asm/bitops.h>
  19 #include <linux/types.h>
  20 #include <linux/kernel.h>
  21 #include <linux/sched.h>
  22 #include <linux/string.h>
  23 #include <linux/mm.h>
  24 #include <linux/socket.h>
  25 #include <linux/sockios.h>
  26 #include <linux/in.h>
  27 #include <linux/errno.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/if_ether.h>
  30 #include <linux/inet.h>
  31 #include <linux/netdevice.h>
  32 #include <linux/etherdevice.h>
  33 #include <linux/notifier.h>
  34 #include <net/ip.h>
  35 #include <net/route.h>
  36 #include <linux/skbuff.h>
  37 #include <net/sock.h>
  38 #include <net/pkt_sched.h>
  39
  40
  41 struct prio_sched_data
  42 {
  43         int bands;
  44         struct tcf_proto *filter_list;
  45         u8  prio2band[TC_PRIO_MAX+1];
  46         struct Qdisc *queues[TCQ_PRIO_BANDS];
  47 };
  48
  49
  50 static __inline__ unsigned prio_classify(struct sk_buff *skb, struct Qdisc *sch)
  51 {
  52         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
  53         struct tcf_result res;
  54         u32 band;
  55
  56         band = skb->priority;
  57         if (TC_H_MAJ(skb->priority) != sch->handle) {
  58                 if (!q->filter_list || tc_classify(skb, q->filter_list, &res)) {
  59                         if (TC_H_MAJ(band))
  60                                 band = 0;
  61                         return q->prio2band[band&TC_PRIO_MAX];
  62                 }
  63                 band = res.classid;
  64         }
  65         band = TC_H_MIN(band) - 1;
  66         return band < q->bands ? band : q->prio2band[0];
  67 }
  68
  69 static int
  70 prio_enqueue(struct sk_buff *skb, struct Qdisc* sch)
  71 {
  72         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
  73         struct Qdisc *qdisc;
  74         int ret;
  75
  76         qdisc = q->queues[prio_classify(skb, sch)];
  77
  78         if ((ret = qdisc->enqueue(skb, qdisc)) == 0) {
  79                 sch->stats.bytes += skb->len;
  80                 sch->stats.packets++;
  81                 sch->q.qlen++;
  82                 return 0;
  83         }
  84         sch->stats.drops++;
  85         return ret;
  86 }
  87
  88
  89 static int
  90 prio_requeue(struct sk_buff *skb, struct Qdisc* sch)
  91 {
  92         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
  93         struct Qdisc *qdisc;
  94         int ret;
  95
  96         qdisc = q->queues[prio_classify(skb, sch)];
  97
  98         if ((ret = qdisc->ops->requeue(skb, qdisc)) == 0) {
  99                 sch->q.qlen++;
 100                 return 0;
 101         }
 102         sch->stats.drops++;
 103         return ret;
 104 }
 105
 106
 107 static struct sk_buff *
 108 prio_dequeue(struct Qdisc* sch)
 109 {
 110         struct sk_buff *skb;
 111         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 112         int prio;
 113         struct Qdisc *qdisc;
 114
 115         for (prio = 0; prio < q->bands; prio++) {
 116                 qdisc = q->queues[prio];
 117                 skb = qdisc->dequeue(qdisc);
 118                 if (skb) {
 119                         sch->q.qlen--;
 120                         return skb;
 121                 }
 122         }
 123         return NULL;
 124
 125 }
 126
 127 static int
 128 prio_drop(struct Qdisc* sch)
 129 {
 130         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 131         int prio;
 132         struct Qdisc *qdisc;
 133
 134         for (prio = q->bands-1; prio >= 0; prio--) {
 135                 qdisc = q->queues[prio];
 136                 if (qdisc->ops->drop(qdisc)) {
 137                         sch->q.qlen--;
 138                         return 1;
 139                 }
 140         }
 141         return 0;
 142 }
 143
 144
 145 static void
 146 prio_reset(struct Qdisc* sch)
 147 {
 148         int prio;
 149         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 150
 151         for (prio=0; prio<q->bands; prio++)
 152                 qdisc_reset(q->queues[prio]);
 153         sch->q.qlen = 0;
 154 }
 155
 156 static void
 157 prio_destroy(struct Qdisc* sch)
 158 {
 159         int prio;
 160         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 161
 162         for (prio=0; prio<q->bands; prio++) {
 163                 qdisc_destroy(q->queues[prio]);
 164                 q->queues[prio] = &noop_qdisc;
 165         }
 166         MOD_DEC_USE_COUNT;
 167 }
 168
 169 static int prio_tune(struct Qdisc *sch, struct rtattr *opt)
 170 {
 171         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 172         struct tc_prio_qopt *qopt = RTA_DATA(opt);
 173         int i;
 174
 175         if (opt->rta_len < RTA_LENGTH(sizeof(*qopt)))
 176                 return -EINVAL;
 177         if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
 178                 return -EINVAL;
 179
 180         for (i=0; i<=TC_PRIO_MAX; i++) {
 181                 if (qopt->priomap[i] >= qopt->bands)
 182                         return -EINVAL;
 183         }
 184
 185         sch_tree_lock(sch);
 186         q->bands = qopt->bands;
 187         memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
 188
 189         for (i=q->bands; i<TCQ_PRIO_BANDS; i++) {
 190                 struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
 191                 if (child != &noop_qdisc)
 192                         qdisc_destroy(child);
 193         }
 194         sch_tree_unlock(sch);
 195
 196         for (i=0; i<=TC_PRIO_MAX; i++) {
 197                 int band = q->prio2band[i];
 198                 if (q->queues[band] == &noop_qdisc) {
 199                         struct Qdisc *child;
 200                         child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
 201                         if (child) {
 202                                 sch_tree_lock(sch);
 203                                 child = xchg(&q->queues[band], child);
 204
 205                                 if (child != &noop_qdisc)
 206                                         qdisc_destroy(child);
 207                                 sch_tree_unlock(sch);
 208                         }
 209                 }
 210         }
 211         return 0;
 212 }
 213
 214 static int prio_init(struct Qdisc *sch, struct rtattr *opt)
 215 {
 216         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 217         int i;
 218
 219         for (i=0; i<TCQ_PRIO_BANDS; i++)
 220                 q->queues[i] = &noop_qdisc;
 221
 222         if (opt == NULL) {
 223                 return -EINVAL;
 224         } else {
 225                 int err;
 226
 227                 if ((err= prio_tune(sch, opt)) != 0)
 228                         return err;
 229         }
 230         MOD_INC_USE_COUNT;
 231         return 0;
 232 }
 233
 234 #ifdef CONFIG_RTNETLINK
 235 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
 236 {
 237         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 238         unsigned char    *b = skb->tail;
 239         struct tc_prio_qopt opt;
 240
 241         opt.bands = q->bands;
 242         memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1);
 243         RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
 244         return skb->len;
 245
 246 rtattr_failure:
 247         skb_trim(skb, b - skb->data);
 248         return -1;
 249 }
 250 #endif
 251
 252 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
 253                       struct Qdisc **old)
 254 {
 255         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 256         unsigned long band = arg - 1;
 257
 258         if (band >= q->bands)
 259                 return -EINVAL;
 260
 261         if (new == NULL)
 262                 new = &noop_qdisc;
 263
 264         sch_tree_lock(sch);
 265         *old = q->queues[band];
 266         q->queues[band] = new;
 267         qdisc_reset(*old);
 268         sch_tree_unlock(sch);
 269
 270         return 0;
 271 }
 272
 273 static struct Qdisc *
 274 prio_leaf(struct Qdisc *sch, unsigned long arg)
 275 {
 276         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 277         unsigned long band = arg - 1;
 278
 279         if (band >= q->bands)
 280                 return NULL;
 281
 282         return q->queues[band];
 283 }
 284
 285 static unsigned long prio_get(struct Qdisc *sch, u32 classid)
 286 {
 287         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 288         unsigned long band = TC_H_MIN(classid);
 289
 290         if (band - 1 >= q->bands)
 291                 return 0;
 292         return band;
 293 }
 294
 295 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
 296 {
 297         return prio_get(sch, classid);
 298 }
 299
 300
 301 static void prio_put(struct Qdisc *q, unsigned long cl)
 302 {
 303         return;
 304 }
 305
 306 static int prio_change(struct Qdisc *sch, u32 handle, u32 parent, struct rtattr **tca, unsigned long *arg)
 307 {
 308         unsigned long cl = *arg;
 309         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 310
 311         if (cl - 1 > q->bands)
 312                 return -ENOENT;
 313         return 0;
 314 }
 315
 316 static int prio_delete(struct Qdisc *sch, unsigned long cl)
 317 {
 318         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 319         if (cl - 1 > q->bands)
 320                 return -ENOENT;
 321         return 0;
 322 }
 323
 324
 325 #ifdef CONFIG_RTNETLINK
 326 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
 327                            struct tcmsg *tcm)
 328 {
 329         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 330
 331         if (cl - 1 > q->bands)
 332                 return -ENOENT;
 333         if (q->queues[cl-1])
 334                 tcm->tcm_info = q->queues[cl-1]->handle;
 335         return 0;
 336 }
 337 #endif
 338
 339 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 340 {
 341         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 342         int prio;
 343
 344         if (arg->stop)
 345                 return;
 346
 347         for (prio = 0; prio < q->bands; prio++) {
 348                 if (arg->count < arg->skip) {
 349                         arg->count++;
 350                         continue;
 351                 }
 352                 if (arg->fn(sch, prio+1, arg) < 0) {
 353                         arg->stop = 1;
 354                         break;
 355                 }
 356                 arg->count++;
 357         }
 358 }
 359
 360 static struct tcf_proto ** prio_find_tcf(struct Qdisc *sch, unsigned long cl)
 361 {
 362         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 363
 364         if (cl)
 365                 return NULL;
 366         return &q->filter_list;
 367 }
 368
 369 static struct Qdisc_class_ops prio_class_ops =
 370 {
 371         prio_graft,
 372         prio_leaf,
 373
 374         prio_get,
 375         prio_put,
 376         prio_change,
 377         prio_delete,
 378         prio_walk,
 379
 380         prio_find_tcf,
 381         prio_bind,
 382         prio_put,
 383
 384 #ifdef CONFIG_RTNETLINK
 385         prio_dump_class,
 386 #endif
 387 };
 388
 389 struct Qdisc_ops prio_qdisc_ops =
 390 {
 391         NULL,
 392         &prio_class_ops,
 393         "prio",
 394         sizeof(struct prio_sched_data),
 395
 396         prio_enqueue,
 397         prio_dequeue,
 398         prio_requeue,
 399         prio_drop,
 400
 401         prio_init,
 402         prio_reset,
 403         prio_destroy,
 404         prio_tune,
 405
 406 #ifdef CONFIG_RTNETLINK
 407         prio_dump,
 408 #endif
 409 };
 410
 411 #ifdef MODULE
 412
 413 int init_module(void)
 414 {
 415         return register_qdisc(&prio_qdisc_ops);
 416 }
 417
 418 void cleanup_module(void)
 419 {
 420         unregister_qdisc(&prio_qdisc_ops);
 421 }
 422
 423 #endif