i386/linux/linux-2.3.21/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  */
  11
  12 #include <linux/config.h>
  13 #include <linux/module.h>
  14 #include <asm/uaccess.h>
  15 #include <asm/system.h>
  16 #include <asm/bitops.h>
  17 #include <linux/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/sched.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/sock.h>
  36 #include <net/pkt_sched.h>
  37
  38
  39 struct prio_sched_data
  40 {
  41         int bands;
  42         struct tcf_proto *filter_list;
  43         u8  prio2band[TC_PRIO_MAX+1];
  44         struct Qdisc *queues[TCQ_PRIO_BANDS];
  45 };
  46
  47
  48 static __inline__ unsigned prio_classify(struct sk_buff *skb, struct Qdisc *sch)
  49 {
  50         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
  51         struct tcf_result res;
  52         u32 band;
  53
  54         band = skb->priority;
  55         if (TC_H_MAJ(skb->priority) != sch->handle) {
  56                 if (!q->filter_list || tc_classify(skb, q->filter_list, &res)) {
  57                         if (TC_H_MAJ(band))
  58                                 band = 0;
  59                         return q->prio2band[band&TC_PRIO_MAX];
  60                 }
  61                 band = res.classid;
  62         }
  63         band = TC_H_MIN(band) - 1;
  64         return band < q->bands ? band : q->prio2band[0];
  65 }
  66
  67 static int
  68 prio_enqueue(struct sk_buff *skb, struct Qdisc* sch)
  69 {
  70         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
  71         struct Qdisc *qdisc;
  72         int ret;
  73
  74         qdisc = q->queues[prio_classify(skb, sch)];
  75
  76         if ((ret = qdisc->enqueue(skb, qdisc)) == 0) {
  77                 sch->stats.bytes += skb->len;
  78                 sch->stats.packets++;
  79                 sch->q.qlen++;
  80                 return 0;
  81         }
  82         sch->stats.drops++;
  83         return ret;
  84 }
  85
  86
  87 static int
  88 prio_requeue(struct sk_buff *skb, struct Qdisc* sch)
  89 {
  90         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
  91         struct Qdisc *qdisc;
  92         int ret;
  93
  94         qdisc = q->queues[prio_classify(skb, sch)];
  95
  96         if ((ret = qdisc->ops->requeue(skb, qdisc)) == 0) {
  97                 sch->q.qlen++;
  98                 return 0;
  99         }
 100         sch->stats.drops++;
 101         return ret;
 102 }
 103
 104
 105 static struct sk_buff *
 106 prio_dequeue(struct Qdisc* sch)
 107 {
 108         struct sk_buff *skb;
 109         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 110         int prio;
 111         struct Qdisc *qdisc;
 112
 113         for (prio = 0; prio < q->bands; prio++) {
 114                 qdisc = q->queues[prio];
 115                 skb = qdisc->dequeue(qdisc);
 116                 if (skb) {
 117                         sch->q.qlen--;
 118                         return skb;
 119                 }
 120         }
 121         return NULL;
 122
 123 }
 124
 125 static int
 126 prio_drop(struct Qdisc* sch)
 127 {
 128         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 129         int prio;
 130         struct Qdisc *qdisc;
 131
 132         for (prio = q->bands-1; prio >= 0; prio--) {
 133                 qdisc = q->queues[prio];
 134                 if (qdisc->ops->drop(qdisc)) {
 135                         sch->q.qlen--;
 136                         return 1;
 137                 }
 138         }
 139         return 0;
 140 }
 141
 142
 143 static void
 144 prio_reset(struct Qdisc* sch)
 145 {
 146         int prio;
 147         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 148
 149         for (prio=0; prio<q->bands; prio++)
 150                 qdisc_reset(q->queues[prio]);
 151         sch->q.qlen = 0;
 152 }
 153
 154 static void
 155 prio_destroy(struct Qdisc* sch)
 156 {
 157         int prio;
 158         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 159
 160         for (prio=0; prio<q->bands; prio++) {
 161                 qdisc_destroy(q->queues[prio]);
 162                 q->queues[prio] = &noop_qdisc;
 163         }
 164         MOD_DEC_USE_COUNT;
 165 }
 166
 167 static int prio_tune(struct Qdisc *sch, struct rtattr *opt)
 168 {
 169         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 170         struct tc_prio_qopt *qopt = RTA_DATA(opt);
 171         int i;
 172
 173         if (opt->rta_len < RTA_LENGTH(sizeof(*qopt)))
 174                 return -EINVAL;
 175         if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
 176                 return -EINVAL;
 177
 178         for (i=0; i<=TC_PRIO_MAX; i++) {
 179                 if (qopt->priomap[i] >= qopt->bands)
 180                         return -EINVAL;
 181         }
 182
 183         sch_tree_lock(sch);
 184         q->bands = qopt->bands;
 185         memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
 186
 187         for (i=q->bands; i<TCQ_PRIO_BANDS; i++) {
 188                 struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
 189                 if (child != &noop_qdisc)
 190                         qdisc_destroy(child);
 191         }
 192         sch_tree_unlock(sch);
 193
 194         for (i=0; i<=TC_PRIO_MAX; i++) {
 195                 int band = q->prio2band[i];
 196                 if (q->queues[band] == &noop_qdisc) {
 197                         struct Qdisc *child;
 198                         child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
 199                         if (child) {
 200                                 sch_tree_lock(sch);
 201                                 child = xchg(&q->queues[band], child);
 202
 203                                 if (child != &noop_qdisc)
 204                                         qdisc_destroy(child);
 205                                 sch_tree_unlock(sch);
 206                         }
 207                 }
 208         }
 209         return 0;
 210 }
 211
 212 static int prio_init(struct Qdisc *sch, struct rtattr *opt)
 213 {
 214         static const u8 prio2band[TC_PRIO_MAX+1] =
 215         { 1, 2, 2, 2, 1, 2, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1 };
 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                 q->bands = 3;
 224                 memcpy(q->prio2band, prio2band, sizeof(prio2band));
 225                 for (i=0; i<3; i++) {
 226                         struct Qdisc *child;
 227                         child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
 228                         if (child)
 229                                 q->queues[i] = child;
 230                 }
 231         } else {
 232                 int err;
 233
 234                 if ((err= prio_tune(sch, opt)) != 0)
 235                         return err;
 236         }
 237         MOD_INC_USE_COUNT;
 238         return 0;
 239 }
 240
 241 #ifdef CONFIG_RTNETLINK
 242 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
 243 {
 244         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 245         unsigned char    *b = skb->tail;
 246         struct tc_prio_qopt opt;
 247
 248         opt.bands = q->bands;
 249         memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1);
 250         RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
 251         return skb->len;
 252
 253 rtattr_failure:
 254         skb_trim(skb, b - skb->data);
 255         return -1;
 256 }
 257 #endif
 258
 259 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
 260                       struct Qdisc **old)
 261 {
 262         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 263         unsigned long band = arg - 1;
 264
 265         if (band >= q->bands)
 266                 return -EINVAL;
 267
 268         if (new == NULL)
 269                 new = &noop_qdisc;
 270
 271         sch_tree_lock(sch);
 272         *old = q->queues[band];
 273         q->queues[band] = new;
 274         qdisc_reset(*old);
 275         sch_tree_unlock(sch);
 276
 277         return 0;
 278 }
 279
 280 static struct Qdisc *
 281 prio_leaf(struct Qdisc *sch, unsigned long arg)
 282 {
 283         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 284         unsigned long band = arg - 1;
 285
 286         if (band >= q->bands)
 287                 return NULL;
 288
 289         return q->queues[band];
 290 }
 291
 292 static unsigned long prio_get(struct Qdisc *sch, u32 classid)
 293 {
 294         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 295         unsigned long band = TC_H_MIN(classid);
 296
 297         if (band - 1 >= q->bands)
 298                 return 0;
 299         return band;
 300 }
 301
 302 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
 303 {
 304         return prio_get(sch, classid);
 305 }
 306
 307
 308 static void prio_put(struct Qdisc *q, unsigned long cl)
 309 {
 310         return;
 311 }
 312
 313 static int prio_change(struct Qdisc *sch, u32 handle, u32 parent, struct rtattr **tca, unsigned long *arg)
 314 {
 315         unsigned long cl = *arg;
 316         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 317
 318         if (cl - 1 > q->bands)
 319                 return -ENOENT;
 320         return 0;
 321 }
 322
 323 static int prio_delete(struct Qdisc *sch, unsigned long cl)
 324 {
 325         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 326         if (cl - 1 > q->bands)
 327                 return -ENOENT;
 328         return 0;
 329 }
 330
 331
 332 #ifdef CONFIG_RTNETLINK
 333 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
 334                            struct tcmsg *tcm)
 335 {
 336         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 337
 338         if (cl - 1 > q->bands)
 339                 return -ENOENT;
 340         if (q->queues[cl-1])
 341                 tcm->tcm_info = q->queues[cl-1]->handle;
 342         return 0;
 343 }
 344 #endif
 345
 346 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 347 {
 348         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 349         int prio;
 350
 351         if (arg->stop)
 352                 return;
 353
 354         for (prio = 0; prio < q->bands; prio++) {
 355                 if (arg->count < arg->skip) {
 356                         arg->count++;
 357                         continue;
 358                 }
 359                 if (arg->fn(sch, prio+1, arg) < 0) {
 360                         arg->stop = 1;
 361                         break;
 362                 }
 363                 arg->count++;
 364         }
 365 }
 366
 367 static struct tcf_proto ** prio_find_tcf(struct Qdisc *sch, unsigned long cl)
 368 {
 369         struct prio_sched_data *q = (struct prio_sched_data *)sch->data;
 370
 371         if (cl)
 372                 return NULL;
 373         return &q->filter_list;
 374 }
 375
 376 static struct Qdisc_class_ops prio_class_ops =
 377 {
 378         prio_graft,
 379         prio_leaf,
 380
 381         prio_get,
 382         prio_put,
 383         prio_change,
 384         prio_delete,
 385         prio_walk,
 386
 387         prio_find_tcf,
 388         prio_bind,
 389         prio_put,
 390
 391 #ifdef CONFIG_RTNETLINK
 392         prio_dump_class,
 393 #endif
 394 };
 395
 396 struct Qdisc_ops prio_qdisc_ops =
 397 {
 398         NULL,
 399         &prio_class_ops,
 400         "prio",
 401         sizeof(struct prio_sched_data),
 402
 403         prio_enqueue,
 404         prio_dequeue,
 405         prio_requeue,
 406         prio_drop,
 407
 408         prio_init,
 409         prio_reset,
 410         prio_destroy,
 411         prio_tune,
 412
 413 #ifdef CONFIG_RTNETLINK
 414         prio_dump,
 415 #endif
 416 };
 417
 418 #ifdef MODULE
 419
 420 int init_module(void)
 421 {
 422         return register_qdisc(&prio_qdisc_ops);
 423 }
 424
 425 void cleanup_module(void)
 426 {
 427         unregister_qdisc(&prio_qdisc_ops);
 428 }
 429
 430 #endif