net/sched/sch_gred.c

   1 /*
   2  * net/sched/sch_gred.c Generic Random Early Detection queue.
   3  *
   4  *
   5  *              This program is free software; you can redistribute it and/or
   6  *              modify it under the terms of the GNU General Public License
   7  *              as published by the Free Software Foundation; either version
   8  *              2 of the License, or (at your option) any later version.
   9  *
  10  * Authors:    J Hadi Salim (hadi@cyberus.ca) 1998-2002
  11  *
  12  *             991129: -  Bug fix with grio mode
  13  *                     - a better sing. AvgQ mode with Grio(WRED)
  14  *                     - A finer grained VQ dequeue based on sugestion
  15  *                       from Ren Liu
  16  *                     - More error checks
  17  *
  18  *  For all the glorious comments look at include/net/red.h
  19  */
  20
  21 #include <linux/slab.h>
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/kernel.h>
  25 #include <linux/skbuff.h>
  26 #include <net/pkt_cls.h>
  27 #include <net/pkt_sched.h>
  28 #include <net/red.h>
  29
  30 #define GRED_DEF_PRIO (MAX_DPs / 2)
  31 #define GRED_VQ_MASK (MAX_DPs - 1)
  32
  33 #define GRED_VQ_RED_FLAGS       (TC_RED_ECN | TC_RED_HARDDROP)
  34
  35 struct gred_sched_data;
  36 struct gred_sched;
  37
  38 struct gred_sched_data {
  39         u32             limit;          /* HARD maximal queue length    */
  40         u32             DP;             /* the drop parameters */
  41         u32             red_flags;      /* virtualQ version of red_flags */
  42         u64             bytesin;        /* bytes seen on virtualQ so far*/
  43         u32             packetsin;      /* packets seen on virtualQ so far*/
  44         u32             backlog;        /* bytes on the virtualQ */
  45         u8              prio;           /* the prio of this vq */
  46
  47         struct red_parms parms;
  48         struct red_vars  vars;
  49         struct red_stats stats;
  50 };
  51
  52 enum {
  53         GRED_WRED_MODE = 1,
  54         GRED_RIO_MODE,
  55 };
  56
  57 struct gred_sched {
  58         struct gred_sched_data *tab[MAX_DPs];
  59         unsigned long   flags;
  60         u32             red_flags;
  61         u32             DPs;
  62         u32             def;
  63         struct red_vars wred_set;
  64 };
  65
  66 static inline int gred_wred_mode(struct gred_sched *table)
  67 {
  68         return test_bit(GRED_WRED_MODE, &table->flags);
  69 }
  70
  71 static inline void gred_enable_wred_mode(struct gred_sched *table)
  72 {
  73         __set_bit(GRED_WRED_MODE, &table->flags);
  74 }
  75
  76 static inline void gred_disable_wred_mode(struct gred_sched *table)
  77 {
  78         __clear_bit(GRED_WRED_MODE, &table->flags);
  79 }
  80
  81 static inline int gred_rio_mode(struct gred_sched *table)
  82 {
  83         return test_bit(GRED_RIO_MODE, &table->flags);
  84 }
  85
  86 static inline void gred_enable_rio_mode(struct gred_sched *table)
  87 {
  88         __set_bit(GRED_RIO_MODE, &table->flags);
  89 }
  90
  91 static inline void gred_disable_rio_mode(struct gred_sched *table)
  92 {
  93         __clear_bit(GRED_RIO_MODE, &table->flags);
  94 }
  95
  96 static inline int gred_wred_mode_check(struct Qdisc *sch)
  97 {
  98         struct gred_sched *table = qdisc_priv(sch);
  99         int i;
 100
 101         /* Really ugly O(n^2) but shouldn't be necessary too frequent. */
 102         for (i = 0; i < table->DPs; i++) {
 103                 struct gred_sched_data *q = table->tab[i];
 104                 int n;
 105
 106                 if (q == NULL)
 107                         continue;
 108
 109                 for (n = i + 1; n < table->DPs; n++)
 110                         if (table->tab[n] && table->tab[n]->prio == q->prio)
 111                                 return 1;
 112         }
 113
 114         return 0;
 115 }
 116
 117 static inline unsigned int gred_backlog(struct gred_sched *table,
 118                                         struct gred_sched_data *q,
 119                                         struct Qdisc *sch)
 120 {
 121         if (gred_wred_mode(table))
 122                 return sch->qstats.backlog;
 123         else
 124                 return q->backlog;
 125 }
 126
 127 static inline u16 tc_index_to_dp(struct sk_buff *skb)
 128 {
 129         return skb->tc_index & GRED_VQ_MASK;
 130 }
 131
 132 static inline void gred_load_wred_set(const struct gred_sched *table,
 133                                       struct gred_sched_data *q)
 134 {
 135         q->vars.qavg = table->wred_set.qavg;
 136         q->vars.qidlestart = table->wred_set.qidlestart;
 137 }
 138
 139 static inline void gred_store_wred_set(struct gred_sched *table,
 140                                        struct gred_sched_data *q)
 141 {
 142         table->wred_set.qavg = q->vars.qavg;
 143         table->wred_set.qidlestart = q->vars.qidlestart;
 144 }
 145
 146 static int gred_use_ecn(struct gred_sched_data *q)
 147 {
 148         return q->red_flags & TC_RED_ECN;
 149 }
 150
 151 static int gred_use_harddrop(struct gred_sched_data *q)
 152 {
 153         return q->red_flags & TC_RED_HARDDROP;
 154 }
 155
 156 static bool gred_per_vq_red_flags_used(struct gred_sched *table)
 157 {
 158         unsigned int i;
 159
 160         /* Local per-vq flags couldn't have been set unless global are 0 */
 161         if (table->red_flags)
 162                 return false;
 163         for (i = 0; i < MAX_DPs; i++)
 164                 if (table->tab[i] && table->tab[i]->red_flags)
 165                         return true;
 166         return false;
 167 }
 168
 169 static int gred_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 170                         struct sk_buff **to_free)
 171 {
 172         struct gred_sched_data *q = NULL;
 173         struct gred_sched *t = qdisc_priv(sch);
 174         unsigned long qavg = 0;
 175         u16 dp = tc_index_to_dp(skb);
 176
 177         if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
 178                 dp = t->def;
 179
 180                 q = t->tab[dp];
 181                 if (!q) {
 182                         /* Pass through packets not assigned to a DP
 183                          * if no default DP has been configured. This
 184                          * allows for DP flows to be left untouched.
 185                          */
 186                         if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <=
 187                                         sch->limit))
 188                                 return qdisc_enqueue_tail(skb, sch);
 189                         else
 190                                 goto drop;
 191                 }
 192
 193                 /* fix tc_index? --could be controversial but needed for
 194                    requeueing */
 195                 skb->tc_index = (skb->tc_index & ~GRED_VQ_MASK) | dp;
 196         }
 197
 198         /* sum up all the qaves of prios < ours to get the new qave */
 199         if (!gred_wred_mode(t) && gred_rio_mode(t)) {
 200                 int i;
 201
 202                 for (i = 0; i < t->DPs; i++) {
 203                         if (t->tab[i] && t->tab[i]->prio < q->prio &&
 204                             !red_is_idling(&t->tab[i]->vars))
 205                                 qavg += t->tab[i]->vars.qavg;
 206                 }
 207
 208         }
 209
 210         q->packetsin++;
 211         q->bytesin += qdisc_pkt_len(skb);
 212
 213         if (gred_wred_mode(t))
 214                 gred_load_wred_set(t, q);
 215
 216         q->vars.qavg = red_calc_qavg(&q->parms,
 217                                      &q->vars,
 218                                      gred_backlog(t, q, sch));
 219
 220         if (red_is_idling(&q->vars))
 221                 red_end_of_idle_period(&q->vars);
 222
 223         if (gred_wred_mode(t))
 224                 gred_store_wred_set(t, q);
 225
 226         switch (red_action(&q->parms, &q->vars, q->vars.qavg + qavg)) {
 227         case RED_DONT_MARK:
 228                 break;
 229
 230         case RED_PROB_MARK:
 231                 qdisc_qstats_overlimit(sch);
 232                 if (!gred_use_ecn(q) || !INET_ECN_set_ce(skb)) {
 233                         q->stats.prob_drop++;
 234                         goto congestion_drop;
 235                 }
 236
 237                 q->stats.prob_mark++;
 238                 break;
 239
 240         case RED_HARD_MARK:
 241                 qdisc_qstats_overlimit(sch);
 242                 if (gred_use_harddrop(q) || !gred_use_ecn(q) ||
 243                     !INET_ECN_set_ce(skb)) {
 244                         q->stats.forced_drop++;
 245                         goto congestion_drop;
 246                 }
 247                 q->stats.forced_mark++;
 248                 break;
 249         }
 250
 251         if (gred_backlog(t, q, sch) + qdisc_pkt_len(skb) <= q->limit) {
 252                 q->backlog += qdisc_pkt_len(skb);
 253                 return qdisc_enqueue_tail(skb, sch);
 254         }
 255
 256         q->stats.pdrop++;
 257 drop:
 258         return qdisc_drop(skb, sch, to_free);
 259
 260 congestion_drop:
 261         qdisc_drop(skb, sch, to_free);
 262         return NET_XMIT_CN;
 263 }
 264
 265 static struct sk_buff *gred_dequeue(struct Qdisc *sch)
 266 {
 267         struct sk_buff *skb;
 268         struct gred_sched *t = qdisc_priv(sch);
 269
 270         skb = qdisc_dequeue_head(sch);
 271
 272         if (skb) {
 273                 struct gred_sched_data *q;
 274                 u16 dp = tc_index_to_dp(skb);
 275
 276                 if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
 277                         net_warn_ratelimited("GRED: Unable to relocate VQ 0x%x after dequeue, screwing up backlog\n",
 278                                              tc_index_to_dp(skb));
 279                 } else {
 280                         q->backlog -= qdisc_pkt_len(skb);
 281
 282                         if (gred_wred_mode(t)) {
 283                                 if (!sch->qstats.backlog)
 284                                         red_start_of_idle_period(&t->wred_set);
 285                         } else {
 286                                 if (!q->backlog)
 287                                         red_start_of_idle_period(&q->vars);
 288                         }
 289                 }
 290
 291                 return skb;
 292         }
 293
 294         return NULL;
 295 }
 296
 297 static void gred_reset(struct Qdisc *sch)
 298 {
 299         int i;
 300         struct gred_sched *t = qdisc_priv(sch);
 301
 302         qdisc_reset_queue(sch);
 303
 304         for (i = 0; i < t->DPs; i++) {
 305                 struct gred_sched_data *q = t->tab[i];
 306
 307                 if (!q)
 308                         continue;
 309
 310                 red_restart(&q->vars);
 311                 q->backlog = 0;
 312         }
 313 }
 314
 315 static void gred_offload(struct Qdisc *sch, enum tc_gred_command command)
 316 {
 317         struct gred_sched *table = qdisc_priv(sch);
 318         struct net_device *dev = qdisc_dev(sch);
 319         struct tc_gred_qopt_offload opt = {
 320                 .command        = command,
 321                 .handle         = sch->handle,
 322                 .parent         = sch->parent,
 323         };
 324
 325         if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
 326                 return;
 327
 328         if (command == TC_GRED_REPLACE) {
 329                 unsigned int i;
 330
 331                 opt.set.grio_on = gred_rio_mode(table);
 332                 opt.set.wred_on = gred_wred_mode(table);
 333                 opt.set.dp_cnt = table->DPs;
 334                 opt.set.dp_def = table->def;
 335
 336                 for (i = 0; i < table->DPs; i++) {
 337                         struct gred_sched_data *q = table->tab[i];
 338
 339                         if (!q)
 340                                 continue;
 341                         opt.set.tab[i].present = true;
 342                         opt.set.tab[i].limit = q->limit;
 343                         opt.set.tab[i].prio = q->prio;
 344                         opt.set.tab[i].min = q->parms.qth_min >> q->parms.Wlog;
 345                         opt.set.tab[i].max = q->parms.qth_max >> q->parms.Wlog;
 346                         opt.set.tab[i].is_ecn = gred_use_ecn(q);
 347                         opt.set.tab[i].is_harddrop = gred_use_harddrop(q);
 348                         opt.set.tab[i].probability = q->parms.max_P;
 349                         opt.set.tab[i].backlog = &q->backlog;
 350                 }
 351                 opt.set.qstats = &sch->qstats;
 352         }
 353
 354         dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_GRED, &opt);
 355 }
 356
 357 static int gred_offload_dump_stats(struct Qdisc *sch)
 358 {
 359         struct gred_sched *table = qdisc_priv(sch);
 360         struct tc_gred_qopt_offload *hw_stats;
 361         unsigned int i;
 362         int ret;
 363
 364         hw_stats = kzalloc(sizeof(*hw_stats), GFP_KERNEL);
 365         if (!hw_stats)
 366                 return -ENOMEM;
 367
 368         hw_stats->command = TC_GRED_STATS;
 369         hw_stats->handle = sch->handle;
 370         hw_stats->parent = sch->parent;
 371
 372         for (i = 0; i < MAX_DPs; i++)
 373                 if (table->tab[i])
 374                         hw_stats->stats.xstats[i] = &table->tab[i]->stats;
 375
 376         ret = qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_GRED, hw_stats);
 377         /* Even if driver returns failure adjust the stats - in case offload
 378          * ended but driver still wants to adjust the values.
 379          */
 380         for (i = 0; i < MAX_DPs; i++) {
 381                 if (!table->tab[i])
 382                         continue;
 383                 table->tab[i]->packetsin += hw_stats->stats.bstats[i].packets;
 384                 table->tab[i]->bytesin += hw_stats->stats.bstats[i].bytes;
 385                 table->tab[i]->backlog += hw_stats->stats.qstats[i].backlog;
 386
 387                 _bstats_update(&sch->bstats,
 388                                hw_stats->stats.bstats[i].bytes,
 389                                hw_stats->stats.bstats[i].packets);
 390                 sch->qstats.qlen += hw_stats->stats.qstats[i].qlen;
 391                 sch->qstats.backlog += hw_stats->stats.qstats[i].backlog;
 392                 sch->qstats.drops += hw_stats->stats.qstats[i].drops;
 393                 sch->qstats.requeues += hw_stats->stats.qstats[i].requeues;
 394                 sch->qstats.overlimits += hw_stats->stats.qstats[i].overlimits;
 395         }
 396
 397         kfree(hw_stats);
 398         return ret;
 399 }
 400
 401 static inline void gred_destroy_vq(struct gred_sched_data *q)
 402 {
 403         kfree(q);
 404 }
 405
 406 static int gred_change_table_def(struct Qdisc *sch, struct nlattr *dps,
 407                                  struct netlink_ext_ack *extack)
 408 {
 409         struct gred_sched *table = qdisc_priv(sch);
 410         struct tc_gred_sopt *sopt;
 411         bool red_flags_changed;
 412         int i;
 413
 414         if (!dps)
 415                 return -EINVAL;
 416
 417         sopt = nla_data(dps);
 418
 419         if (sopt->DPs > MAX_DPs) {
 420                 NL_SET_ERR_MSG_MOD(extack, "number of virtual queues too high");
 421                 return -EINVAL;
 422         }
 423         if (sopt->DPs == 0) {
 424                 NL_SET_ERR_MSG_MOD(extack,
 425                                    "number of virtual queues can't be 0");
 426                 return -EINVAL;
 427         }
 428         if (sopt->def_DP >= sopt->DPs) {
 429                 NL_SET_ERR_MSG_MOD(extack, "default virtual queue above virtual queue count");
 430                 return -EINVAL;
 431         }
 432         if (sopt->flags && gred_per_vq_red_flags_used(table)) {
 433                 NL_SET_ERR_MSG_MOD(extack, "can't set per-Qdisc RED flags when per-virtual queue flags are used");
 434                 return -EINVAL;
 435         }
 436
 437         sch_tree_lock(sch);
 438         table->DPs = sopt->DPs;
 439         table->def = sopt->def_DP;
 440         red_flags_changed = table->red_flags != sopt->flags;
 441         table->red_flags = sopt->flags;
 442
 443         /*
 444          * Every entry point to GRED is synchronized with the above code
 445          * and the DP is checked against DPs, i.e. shadowed VQs can no
 446          * longer be found so we can unlock right here.
 447          */
 448         sch_tree_unlock(sch);
 449
 450         if (sopt->grio) {
 451                 gred_enable_rio_mode(table);
 452                 gred_disable_wred_mode(table);
 453                 if (gred_wred_mode_check(sch))
 454                         gred_enable_wred_mode(table);
 455         } else {
 456                 gred_disable_rio_mode(table);
 457                 gred_disable_wred_mode(table);
 458         }
 459
 460         if (red_flags_changed)
 461                 for (i = 0; i < table->DPs; i++)
 462                         if (table->tab[i])
 463                                 table->tab[i]->red_flags =
 464                                         table->red_flags & GRED_VQ_RED_FLAGS;
 465
 466         for (i = table->DPs; i < MAX_DPs; i++) {
 467                 if (table->tab[i]) {
 468                         pr_warn("GRED: Warning: Destroying shadowed VQ 0x%x\n",
 469                                 i);
 470                         gred_destroy_vq(table->tab[i]);
 471                         table->tab[i] = NULL;
 472                 }
 473         }
 474
 475         gred_offload(sch, TC_GRED_REPLACE);
 476         return 0;
 477 }
 478
 479 static inline int gred_change_vq(struct Qdisc *sch, int dp,
 480                                  struct tc_gred_qopt *ctl, int prio,
 481                                  u8 *stab, u32 max_P,
 482                                  struct gred_sched_data **prealloc,
 483                                  struct netlink_ext_ack *extack)
 484 {
 485         struct gred_sched *table = qdisc_priv(sch);
 486         struct gred_sched_data *q = table->tab[dp];
 487
 488         if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog)) {
 489                 NL_SET_ERR_MSG_MOD(extack, "invalid RED parameters");
 490                 return -EINVAL;
 491         }
 492
 493         if (!q) {
 494                 table->tab[dp] = q = *prealloc;
 495                 *prealloc = NULL;
 496                 if (!q)
 497                         return -ENOMEM;
 498                 q->red_flags = table->red_flags & GRED_VQ_RED_FLAGS;
 499         }
 500
 501         q->DP = dp;
 502         q->prio = prio;
 503         if (ctl->limit > sch->limit)
 504                 q->limit = sch->limit;
 505         else
 506                 q->limit = ctl->limit;
 507
 508         if (q->backlog == 0)
 509                 red_end_of_idle_period(&q->vars);
 510
 511         red_set_parms(&q->parms,
 512                       ctl->qth_min, ctl->qth_max, ctl->Wlog, ctl->Plog,
 513                       ctl->Scell_log, stab, max_P);
 514         red_set_vars(&q->vars);
 515         return 0;
 516 }
 517
 518 static const struct nla_policy gred_vq_policy[TCA_GRED_VQ_MAX + 1] = {
 519         [TCA_GRED_VQ_DP]        = { .type = NLA_U32 },
 520         [TCA_GRED_VQ_FLAGS]     = { .type = NLA_U32 },
 521 };
 522
 523 static const struct nla_policy gred_vqe_policy[TCA_GRED_VQ_ENTRY_MAX + 1] = {
 524         [TCA_GRED_VQ_ENTRY]     = { .type = NLA_NESTED },
 525 };
 526
 527 static const struct nla_policy gred_policy[TCA_GRED_MAX + 1] = {
 528         [TCA_GRED_PARMS]        = { .len = sizeof(struct tc_gred_qopt) },
 529         [TCA_GRED_STAB]         = { .len = 256 },
 530         [TCA_GRED_DPS]          = { .len = sizeof(struct tc_gred_sopt) },
 531         [TCA_GRED_MAX_P]        = { .type = NLA_U32 },
 532         [TCA_GRED_LIMIT]        = { .type = NLA_U32 },
 533         [TCA_GRED_VQ_LIST]      = { .type = NLA_NESTED },
 534 };
 535
 536 static void gred_vq_apply(struct gred_sched *table, const struct nlattr *entry)
 537 {
 538         struct nlattr *tb[TCA_GRED_VQ_MAX + 1];
 539         u32 dp;
 540
 541         nla_parse_nested(tb, TCA_GRED_VQ_MAX, entry, gred_vq_policy, NULL);
 542
 543         dp = nla_get_u32(tb[TCA_GRED_VQ_DP]);
 544
 545         if (tb[TCA_GRED_VQ_FLAGS])
 546                 table->tab[dp]->red_flags = nla_get_u32(tb[TCA_GRED_VQ_FLAGS]);
 547 }
 548
 549 static void gred_vqs_apply(struct gred_sched *table, struct nlattr *vqs)
 550 {
 551         const struct nlattr *attr;
 552         int rem;
 553
 554         nla_for_each_nested(attr, vqs, rem) {
 555                 switch (nla_type(attr)) {
 556                 case TCA_GRED_VQ_ENTRY:
 557                         gred_vq_apply(table, attr);
 558                         break;
 559                 }
 560         }
 561 }
 562
 563 static int gred_vq_validate(struct gred_sched *table, u32 cdp,
 564                             const struct nlattr *entry,
 565                             struct netlink_ext_ack *extack)
 566 {
 567         struct nlattr *tb[TCA_GRED_VQ_MAX + 1];
 568         int err;
 569         u32 dp;
 570
 571         err = nla_parse_nested(tb, TCA_GRED_VQ_MAX, entry, gred_vq_policy,
 572                                extack);
 573         if (err < 0)
 574                 return err;
 575
 576         if (!tb[TCA_GRED_VQ_DP]) {
 577                 NL_SET_ERR_MSG_MOD(extack, "Virtual queue with no index specified");
 578                 return -EINVAL;
 579         }
 580         dp = nla_get_u32(tb[TCA_GRED_VQ_DP]);
 581         if (dp >= table->DPs) {
 582                 NL_SET_ERR_MSG_MOD(extack, "Virtual queue with index out of bounds");
 583                 return -EINVAL;
 584         }
 585         if (dp != cdp && !table->tab[dp]) {
 586                 NL_SET_ERR_MSG_MOD(extack, "Virtual queue not yet instantiated");
 587                 return -EINVAL;
 588         }
 589
 590         if (tb[TCA_GRED_VQ_FLAGS]) {
 591                 u32 red_flags = nla_get_u32(tb[TCA_GRED_VQ_FLAGS]);
 592
 593                 if (table->red_flags && table->red_flags != red_flags) {
 594                         NL_SET_ERR_MSG_MOD(extack, "can't change per-virtual queue RED flags when per-Qdisc flags are used");
 595                         return -EINVAL;
 596                 }
 597                 if (red_flags & ~GRED_VQ_RED_FLAGS) {
 598                         NL_SET_ERR_MSG_MOD(extack,
 599                                            "invalid RED flags specified");
 600                         return -EINVAL;
 601                 }
 602         }
 603
 604         return 0;
 605 }
 606
 607 static int gred_vqs_validate(struct gred_sched *table, u32 cdp,
 608                              struct nlattr *vqs, struct netlink_ext_ack *extack)
 609 {
 610         const struct nlattr *attr;
 611         int rem, err;
 612
 613         err = nla_validate_nested(vqs, TCA_GRED_VQ_ENTRY_MAX,
 614                                   gred_vqe_policy, extack);
 615         if (err < 0)
 616                 return err;
 617
 618         nla_for_each_nested(attr, vqs, rem) {
 619                 switch (nla_type(attr)) {
 620                 case TCA_GRED_VQ_ENTRY:
 621                         err = gred_vq_validate(table, cdp, attr, extack);
 622                         if (err)
 623                                 return err;
 624                         break;
 625                 default:
 626                         NL_SET_ERR_MSG_MOD(extack, "GRED_VQ_LIST can contain only entry attributes");
 627                         return -EINVAL;
 628                 }
 629         }
 630
 631         if (rem > 0) {
 632                 NL_SET_ERR_MSG_MOD(extack, "Trailing data after parsing virtual queue list");
 633                 return -EINVAL;
 634         }
 635
 636         return 0;
 637 }
 638
 639 static int gred_change(struct Qdisc *sch, struct nlattr *opt,
 640                        struct netlink_ext_ack *extack)
 641 {
 642         struct gred_sched *table = qdisc_priv(sch);
 643         struct tc_gred_qopt *ctl;
 644         struct nlattr *tb[TCA_GRED_MAX + 1];
 645         int err, prio = GRED_DEF_PRIO;
 646         u8 *stab;
 647         u32 max_P;
 648         struct gred_sched_data *prealloc;
 649
 650         if (opt == NULL)
 651                 return -EINVAL;
 652
 653         err = nla_parse_nested(tb, TCA_GRED_MAX, opt, gred_policy, extack);
 654         if (err < 0)
 655                 return err;
 656
 657         if (tb[TCA_GRED_PARMS] == NULL && tb[TCA_GRED_STAB] == NULL) {
 658                 if (tb[TCA_GRED_LIMIT] != NULL)
 659                         sch->limit = nla_get_u32(tb[TCA_GRED_LIMIT]);
 660                 return gred_change_table_def(sch, tb[TCA_GRED_DPS], extack);
 661         }
 662
 663         if (tb[TCA_GRED_PARMS] == NULL ||
 664             tb[TCA_GRED_STAB] == NULL ||
 665             tb[TCA_GRED_LIMIT] != NULL) {
 666                 NL_SET_ERR_MSG_MOD(extack, "can't configure Qdisc and virtual queue at the same time");
 667                 return -EINVAL;
 668         }
 669
 670         max_P = tb[TCA_GRED_MAX_P] ? nla_get_u32(tb[TCA_GRED_MAX_P]) : 0;
 671
 672         ctl = nla_data(tb[TCA_GRED_PARMS]);
 673         stab = nla_data(tb[TCA_GRED_STAB]);
 674
 675         if (ctl->DP >= table->DPs) {
 676                 NL_SET_ERR_MSG_MOD(extack, "virtual queue index above virtual queue count");
 677                 return -EINVAL;
 678         }
 679
 680         if (tb[TCA_GRED_VQ_LIST]) {
 681                 err = gred_vqs_validate(table, ctl->DP, tb[TCA_GRED_VQ_LIST],
 682                                         extack);
 683                 if (err)
 684                         return err;
 685         }
 686
 687         if (gred_rio_mode(table)) {
 688                 if (ctl->prio == 0) {
 689                         int def_prio = GRED_DEF_PRIO;
 690
 691                         if (table->tab[table->def])
 692                                 def_prio = table->tab[table->def]->prio;
 693
 694                         printk(KERN_DEBUG "GRED: DP %u does not have a prio "
 695                                "setting default to %d\n", ctl->DP, def_prio);
 696
 697                         prio = def_prio;
 698                 } else
 699                         prio = ctl->prio;
 700         }
 701
 702         prealloc = kzalloc(sizeof(*prealloc), GFP_KERNEL);
 703         sch_tree_lock(sch);
 704
 705         err = gred_change_vq(sch, ctl->DP, ctl, prio, stab, max_P, &prealloc,
 706                              extack);
 707         if (err < 0)
 708                 goto err_unlock_free;
 709
 710         if (tb[TCA_GRED_VQ_LIST])
 711                 gred_vqs_apply(table, tb[TCA_GRED_VQ_LIST]);
 712
 713         if (gred_rio_mode(table)) {
 714                 gred_disable_wred_mode(table);
 715                 if (gred_wred_mode_check(sch))
 716                         gred_enable_wred_mode(table);
 717         }
 718
 719         sch_tree_unlock(sch);
 720         kfree(prealloc);
 721
 722         gred_offload(sch, TC_GRED_REPLACE);
 723         return 0;
 724
 725 err_unlock_free:
 726         sch_tree_unlock(sch);
 727         kfree(prealloc);
 728         return err;
 729 }
 730
 731 static int gred_init(struct Qdisc *sch, struct nlattr *opt,
 732                      struct netlink_ext_ack *extack)
 733 {
 734         struct nlattr *tb[TCA_GRED_MAX + 1];
 735         int err;
 736
 737         if (!opt)
 738                 return -EINVAL;
 739
 740         err = nla_parse_nested(tb, TCA_GRED_MAX, opt, gred_policy, extack);
 741         if (err < 0)
 742                 return err;
 743
 744         if (tb[TCA_GRED_PARMS] || tb[TCA_GRED_STAB]) {
 745                 NL_SET_ERR_MSG_MOD(extack,
 746                                    "virtual queue configuration can't be specified at initialization time");
 747                 return -EINVAL;
 748         }
 749
 750         if (tb[TCA_GRED_LIMIT])
 751                 sch->limit = nla_get_u32(tb[TCA_GRED_LIMIT]);
 752         else
 753                 sch->limit = qdisc_dev(sch)->tx_queue_len
 754                              * psched_mtu(qdisc_dev(sch));
 755
 756         return gred_change_table_def(sch, tb[TCA_GRED_DPS], extack);
 757 }
 758
 759 static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
 760 {
 761         struct gred_sched *table = qdisc_priv(sch);
 762         struct nlattr *parms, *vqs, *opts = NULL;
 763         int i;
 764         u32 max_p[MAX_DPs];
 765         struct tc_gred_sopt sopt = {
 766                 .DPs    = table->DPs,
 767                 .def_DP = table->def,
 768                 .grio   = gred_rio_mode(table),
 769                 .flags  = table->red_flags,
 770         };
 771
 772         if (gred_offload_dump_stats(sch))
 773                 goto nla_put_failure;
 774
 775         opts = nla_nest_start(skb, TCA_OPTIONS);
 776         if (opts == NULL)
 777                 goto nla_put_failure;
 778         if (nla_put(skb, TCA_GRED_DPS, sizeof(sopt), &sopt))
 779                 goto nla_put_failure;
 780
 781         for (i = 0; i < MAX_DPs; i++) {
 782                 struct gred_sched_data *q = table->tab[i];
 783
 784                 max_p[i] = q ? q->parms.max_P : 0;
 785         }
 786         if (nla_put(skb, TCA_GRED_MAX_P, sizeof(max_p), max_p))
 787                 goto nla_put_failure;
 788
 789         if (nla_put_u32(skb, TCA_GRED_LIMIT, sch->limit))
 790                 goto nla_put_failure;
 791
 792         /* Old style all-in-one dump of VQs */
 793         parms = nla_nest_start(skb, TCA_GRED_PARMS);
 794         if (parms == NULL)
 795                 goto nla_put_failure;
 796
 797         for (i = 0; i < MAX_DPs; i++) {
 798                 struct gred_sched_data *q = table->tab[i];
 799                 struct tc_gred_qopt opt;
 800                 unsigned long qavg;
 801
 802                 memset(&opt, 0, sizeof(opt));
 803
 804                 if (!q) {
 805                         /* hack -- fix at some point with proper message
 806                            This is how we indicate to tc that there is no VQ
 807                            at this DP */
 808
 809                         opt.DP = MAX_DPs + i;
 810                         goto append_opt;
 811                 }
 812
 813                 opt.limit       = q->limit;
 814                 opt.DP          = q->DP;
 815                 opt.backlog     = gred_backlog(table, q, sch);
 816                 opt.prio        = q->prio;
 817                 opt.qth_min     = q->parms.qth_min >> q->parms.Wlog;
 818                 opt.qth_max     = q->parms.qth_max >> q->parms.Wlog;
 819                 opt.Wlog        = q->parms.Wlog;
 820                 opt.Plog        = q->parms.Plog;
 821                 opt.Scell_log   = q->parms.Scell_log;
 822                 opt.other       = q->stats.other;
 823                 opt.early       = q->stats.prob_drop;
 824                 opt.forced      = q->stats.forced_drop;
 825                 opt.pdrop       = q->stats.pdrop;
 826                 opt.packets     = q->packetsin;
 827                 opt.bytesin     = q->bytesin;
 828
 829                 if (gred_wred_mode(table))
 830                         gred_load_wred_set(table, q);
 831
 832                 qavg = red_calc_qavg(&q->parms, &q->vars,
 833                                      q->vars.qavg >> q->parms.Wlog);
 834                 opt.qave = qavg >> q->parms.Wlog;
 835
 836 append_opt:
 837                 if (nla_append(skb, sizeof(opt), &opt) < 0)
 838                         goto nla_put_failure;
 839         }
 840
 841         nla_nest_end(skb, parms);
 842
 843         /* Dump the VQs again, in more structured way */
 844         vqs = nla_nest_start(skb, TCA_GRED_VQ_LIST);
 845         if (!vqs)
 846                 goto nla_put_failure;
 847
 848         for (i = 0; i < MAX_DPs; i++) {
 849                 struct gred_sched_data *q = table->tab[i];
 850                 struct nlattr *vq;
 851
 852                 if (!q)
 853                         continue;
 854
 855                 vq = nla_nest_start(skb, TCA_GRED_VQ_ENTRY);
 856                 if (!vq)
 857                         goto nla_put_failure;
 858
 859                 if (nla_put_u32(skb, TCA_GRED_VQ_DP, q->DP))
 860                         goto nla_put_failure;
 861
 862                 if (nla_put_u32(skb, TCA_GRED_VQ_FLAGS, q->red_flags))
 863                         goto nla_put_failure;
 864
 865                 /* Stats */
 866                 if (nla_put_u64_64bit(skb, TCA_GRED_VQ_STAT_BYTES, q->bytesin,
 867                                       TCA_GRED_VQ_PAD))
 868                         goto nla_put_failure;
 869                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PACKETS, q->packetsin))
 870                         goto nla_put_failure;
 871                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_BACKLOG,
 872                                 gred_backlog(table, q, sch)))
 873                         goto nla_put_failure;
 874                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PROB_DROP,
 875                                 q->stats.prob_drop))
 876                         goto nla_put_failure;
 877                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PROB_MARK,
 878                                 q->stats.prob_mark))
 879                         goto nla_put_failure;
 880                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_FORCED_DROP,
 881                                 q->stats.forced_drop))
 882                         goto nla_put_failure;
 883                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_FORCED_MARK,
 884                                 q->stats.forced_mark))
 885                         goto nla_put_failure;
 886                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PDROP, q->stats.pdrop))
 887                         goto nla_put_failure;
 888                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_OTHER, q->stats.other))
 889                         goto nla_put_failure;
 890
 891                 nla_nest_end(skb, vq);
 892         }
 893         nla_nest_end(skb, vqs);
 894
 895         return nla_nest_end(skb, opts);
 896
 897 nla_put_failure:
 898         nla_nest_cancel(skb, opts);
 899         return -EMSGSIZE;
 900 }
 901
 902 static void gred_destroy(struct Qdisc *sch)
 903 {
 904         struct gred_sched *table = qdisc_priv(sch);
 905         int i;
 906
 907         for (i = 0; i < table->DPs; i++) {
 908                 if (table->tab[i])
 909                         gred_destroy_vq(table->tab[i]);
 910         }
 911         gred_offload(sch, TC_GRED_DESTROY);
 912 }
 913
 914 static struct Qdisc_ops gred_qdisc_ops __read_mostly = {
 915         .id             =       "gred",
 916         .priv_size      =       sizeof(struct gred_sched),
 917         .enqueue        =       gred_enqueue,
 918         .dequeue        =       gred_dequeue,
 919         .peek           =       qdisc_peek_head,
 920         .init           =       gred_init,
 921         .reset          =       gred_reset,
 922         .destroy        =       gred_destroy,
 923         .change         =       gred_change,
 924         .dump           =       gred_dump,
 925         .owner          =       THIS_MODULE,
 926 };
 927
 928 static int __init gred_module_init(void)
 929 {
 930         return register_qdisc(&gred_qdisc_ops);
 931 }
 932
 933 static void __exit gred_module_exit(void)
 934 {
 935         unregister_qdisc(&gred_qdisc_ops);
 936 }
 937
 938 module_init(gred_module_init)
 939 module_exit(gred_module_exit)
 940
 941 MODULE_LICENSE("GPL");