net/sched/sch_gred.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/sch_gred.c Generic Random Early Detection queue.
   4  *
   5  * Authors:    J Hadi Salim (hadi@cyberus.ca) 1998-2002
   6  *
   7  *             991129: -  Bug fix with grio mode
   8  *                     - a better sing. AvgQ mode with Grio(WRED)
   9  *                     - A finer grained VQ dequeue based on sugestion
  10  *                       from Ren Liu
  11  *                     - More error checks
  12  *
  13  *  For all the glorious comments look at include/net/red.h
  14  */
  15
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/types.h>
  19 #include <linux/kernel.h>
  20 #include <linux/skbuff.h>
  21 #include <net/pkt_cls.h>
  22 #include <net/pkt_sched.h>
  23 #include <net/red.h>
  24
  25 #define GRED_DEF_PRIO (MAX_DPs / 2)
  26 #define GRED_VQ_MASK (MAX_DPs - 1)
  27
  28 #define GRED_VQ_RED_FLAGS       (TC_RED_ECN | TC_RED_HARDDROP)
  29
  30 struct gred_sched_data;
  31 struct gred_sched;
  32
  33 struct gred_sched_data {
  34         u32             limit;          /* HARD maximal queue length    */
  35         u32             DP;             /* the drop parameters */
  36         u32             red_flags;      /* virtualQ version of red_flags */
  37         u64             bytesin;        /* bytes seen on virtualQ so far*/
  38         u32             packetsin;      /* packets seen on virtualQ so far*/
  39         u32             backlog;        /* bytes on the virtualQ */
  40         u8              prio;           /* the prio of this vq */
  41
  42         struct red_parms parms;
  43         struct red_vars  vars;
  44         struct red_stats stats;
  45 };
  46
  47 enum {
  48         GRED_WRED_MODE = 1,
  49         GRED_RIO_MODE,
  50 };
  51
  52 struct gred_sched {
  53         struct gred_sched_data *tab[MAX_DPs];
  54         unsigned long   flags;
  55         u32             red_flags;
  56         u32             DPs;
  57         u32             def;
  58         struct red_vars wred_set;
  59 };
  60
  61 static inline int gred_wred_mode(struct gred_sched *table)
  62 {
  63         return test_bit(GRED_WRED_MODE, &table->flags);
  64 }
  65
  66 static inline void gred_enable_wred_mode(struct gred_sched *table)
  67 {
  68         __set_bit(GRED_WRED_MODE, &table->flags);
  69 }
  70
  71 static inline void gred_disable_wred_mode(struct gred_sched *table)
  72 {
  73         __clear_bit(GRED_WRED_MODE, &table->flags);
  74 }
  75
  76 static inline int gred_rio_mode(struct gred_sched *table)
  77 {
  78         return test_bit(GRED_RIO_MODE, &table->flags);
  79 }
  80
  81 static inline void gred_enable_rio_mode(struct gred_sched *table)
  82 {
  83         __set_bit(GRED_RIO_MODE, &table->flags);
  84 }
  85
  86 static inline void gred_disable_rio_mode(struct gred_sched *table)
  87 {
  88         __clear_bit(GRED_RIO_MODE, &table->flags);
  89 }
  90
  91 static inline int gred_wred_mode_check(struct Qdisc *sch)
  92 {
  93         struct gred_sched *table = qdisc_priv(sch);
  94         int i;
  95
  96         /* Really ugly O(n^2) but shouldn't be necessary too frequent. */
  97         for (i = 0; i < table->DPs; i++) {
  98                 struct gred_sched_data *q = table->tab[i];
  99                 int n;
 100
 101                 if (q == NULL)
 102                         continue;
 103
 104                 for (n = i + 1; n < table->DPs; n++)
 105                         if (table->tab[n] && table->tab[n]->prio == q->prio)
 106                                 return 1;
 107         }
 108
 109         return 0;
 110 }
 111
 112 static inline unsigned int gred_backlog(struct gred_sched *table,
 113                                         struct gred_sched_data *q,
 114                                         struct Qdisc *sch)
 115 {
 116         if (gred_wred_mode(table))
 117                 return sch->qstats.backlog;
 118         else
 119                 return q->backlog;
 120 }
 121
 122 static inline u16 tc_index_to_dp(struct sk_buff *skb)
 123 {
 124         return skb->tc_index & GRED_VQ_MASK;
 125 }
 126
 127 static inline void gred_load_wred_set(const struct gred_sched *table,
 128                                       struct gred_sched_data *q)
 129 {
 130         q->vars.qavg = table->wred_set.qavg;
 131         q->vars.qidlestart = table->wred_set.qidlestart;
 132 }
 133
 134 static inline void gred_store_wred_set(struct gred_sched *table,
 135                                        struct gred_sched_data *q)
 136 {
 137         table->wred_set.qavg = q->vars.qavg;
 138         table->wred_set.qidlestart = q->vars.qidlestart;
 139 }
 140
 141 static int gred_use_ecn(struct gred_sched_data *q)
 142 {
 143         return q->red_flags & TC_RED_ECN;
 144 }
 145
 146 static int gred_use_harddrop(struct gred_sched_data *q)
 147 {
 148         return q->red_flags & TC_RED_HARDDROP;
 149 }
 150
 151 static bool gred_per_vq_red_flags_used(struct gred_sched *table)
 152 {
 153         unsigned int i;
 154
 155         /* Local per-vq flags couldn't have been set unless global are 0 */
 156         if (table->red_flags)
 157                 return false;
 158         for (i = 0; i < MAX_DPs; i++)
 159                 if (table->tab[i] && table->tab[i]->red_flags)
 160                         return true;
 161         return false;
 162 }
 163
 164 static int gred_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 165                         struct sk_buff **to_free)
 166 {
 167         struct gred_sched_data *q = NULL;
 168         struct gred_sched *t = qdisc_priv(sch);
 169         unsigned long qavg = 0;
 170         u16 dp = tc_index_to_dp(skb);
 171
 172         if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
 173                 dp = t->def;
 174
 175                 q = t->tab[dp];
 176                 if (!q) {
 177                         /* Pass through packets not assigned to a DP
 178                          * if no default DP has been configured. This
 179                          * allows for DP flows to be left untouched.
 180                          */
 181                         if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <=
 182                                         sch->limit))
 183                                 return qdisc_enqueue_tail(skb, sch);
 184                         else
 185                                 goto drop;
 186                 }
 187
 188                 /* fix tc_index? --could be controversial but needed for
 189                    requeueing */
 190                 skb->tc_index = (skb->tc_index & ~GRED_VQ_MASK) | dp;
 191         }
 192
 193         /* sum up all the qaves of prios < ours to get the new qave */
 194         if (!gred_wred_mode(t) && gred_rio_mode(t)) {
 195                 int i;
 196
 197                 for (i = 0; i < t->DPs; i++) {
 198                         if (t->tab[i] && t->tab[i]->prio < q->prio &&
 199                             !red_is_idling(&t->tab[i]->vars))
 200                                 qavg += t->tab[i]->vars.qavg;
 201                 }
 202
 203         }
 204
 205         q->packetsin++;
 206         q->bytesin += qdisc_pkt_len(skb);
 207
 208         if (gred_wred_mode(t))
 209                 gred_load_wred_set(t, q);
 210
 211         q->vars.qavg = red_calc_qavg(&q->parms,
 212                                      &q->vars,
 213                                      gred_backlog(t, q, sch));
 214
 215         if (red_is_idling(&q->vars))
 216                 red_end_of_idle_period(&q->vars);
 217
 218         if (gred_wred_mode(t))
 219                 gred_store_wred_set(t, q);
 220
 221         switch (red_action(&q->parms, &q->vars, q->vars.qavg + qavg)) {
 222         case RED_DONT_MARK:
 223                 break;
 224
 225         case RED_PROB_MARK:
 226                 qdisc_qstats_overlimit(sch);
 227                 if (!gred_use_ecn(q) || !INET_ECN_set_ce(skb)) {
 228                         q->stats.prob_drop++;
 229                         goto congestion_drop;
 230                 }
 231
 232                 q->stats.prob_mark++;
 233                 break;
 234
 235         case RED_HARD_MARK:
 236                 qdisc_qstats_overlimit(sch);
 237                 if (gred_use_harddrop(q) || !gred_use_ecn(q) ||
 238                     !INET_ECN_set_ce(skb)) {
 239                         q->stats.forced_drop++;
 240                         goto congestion_drop;
 241                 }
 242                 q->stats.forced_mark++;
 243                 break;
 244         }
 245
 246         if (gred_backlog(t, q, sch) + qdisc_pkt_len(skb) <= q->limit) {
 247                 q->backlog += qdisc_pkt_len(skb);
 248                 return qdisc_enqueue_tail(skb, sch);
 249         }
 250
 251         q->stats.pdrop++;
 252 drop:
 253         return qdisc_drop(skb, sch, to_free);
 254
 255 congestion_drop:
 256         qdisc_drop(skb, sch, to_free);
 257         return NET_XMIT_CN;
 258 }
 259
 260 static struct sk_buff *gred_dequeue(struct Qdisc *sch)
 261 {
 262         struct sk_buff *skb;
 263         struct gred_sched *t = qdisc_priv(sch);
 264
 265         skb = qdisc_dequeue_head(sch);
 266
 267         if (skb) {
 268                 struct gred_sched_data *q;
 269                 u16 dp = tc_index_to_dp(skb);
 270
 271                 if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
 272                         net_warn_ratelimited("GRED: Unable to relocate VQ 0x%x after dequeue, screwing up backlog\n",
 273                                              tc_index_to_dp(skb));
 274                 } else {
 275                         q->backlog -= qdisc_pkt_len(skb);
 276
 277                         if (gred_wred_mode(t)) {
 278                                 if (!sch->qstats.backlog)
 279                                         red_start_of_idle_period(&t->wred_set);
 280                         } else {
 281                                 if (!q->backlog)
 282                                         red_start_of_idle_period(&q->vars);
 283                         }
 284                 }
 285
 286                 return skb;
 287         }
 288
 289         return NULL;
 290 }
 291
 292 static void gred_reset(struct Qdisc *sch)
 293 {
 294         int i;
 295         struct gred_sched *t = qdisc_priv(sch);
 296
 297         qdisc_reset_queue(sch);
 298
 299         for (i = 0; i < t->DPs; i++) {
 300                 struct gred_sched_data *q = t->tab[i];
 301
 302                 if (!q)
 303                         continue;
 304
 305                 red_restart(&q->vars);
 306                 q->backlog = 0;
 307         }
 308 }
 309
 310 static void gred_offload(struct Qdisc *sch, enum tc_gred_command command)
 311 {
 312         struct gred_sched *table = qdisc_priv(sch);
 313         struct net_device *dev = qdisc_dev(sch);
 314         struct tc_gred_qopt_offload opt = {
 315                 .command        = command,
 316                 .handle         = sch->handle,
 317                 .parent         = sch->parent,
 318         };
 319
 320         if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
 321                 return;
 322
 323         if (command == TC_GRED_REPLACE) {
 324                 unsigned int i;
 325
 326                 opt.set.grio_on = gred_rio_mode(table);
 327                 opt.set.wred_on = gred_wred_mode(table);
 328                 opt.set.dp_cnt = table->DPs;
 329                 opt.set.dp_def = table->def;
 330
 331                 for (i = 0; i < table->DPs; i++) {
 332                         struct gred_sched_data *q = table->tab[i];
 333
 334                         if (!q)
 335                                 continue;
 336                         opt.set.tab[i].present = true;
 337                         opt.set.tab[i].limit = q->limit;
 338                         opt.set.tab[i].prio = q->prio;
 339                         opt.set.tab[i].min = q->parms.qth_min >> q->parms.Wlog;
 340                         opt.set.tab[i].max = q->parms.qth_max >> q->parms.Wlog;
 341                         opt.set.tab[i].is_ecn = gred_use_ecn(q);
 342                         opt.set.tab[i].is_harddrop = gred_use_harddrop(q);
 343                         opt.set.tab[i].probability = q->parms.max_P;
 344                         opt.set.tab[i].backlog = &q->backlog;
 345                 }
 346                 opt.set.qstats = &sch->qstats;
 347         }
 348
 349         dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_GRED, &opt);
 350 }
 351
 352 static int gred_offload_dump_stats(struct Qdisc *sch)
 353 {
 354         struct gred_sched *table = qdisc_priv(sch);
 355         struct tc_gred_qopt_offload *hw_stats;
 356         unsigned int i;
 357         int ret;
 358
 359         hw_stats = kzalloc(sizeof(*hw_stats), GFP_KERNEL);
 360         if (!hw_stats)
 361                 return -ENOMEM;
 362
 363         hw_stats->command = TC_GRED_STATS;
 364         hw_stats->handle = sch->handle;
 365         hw_stats->parent = sch->parent;
 366
 367         for (i = 0; i < MAX_DPs; i++)
 368                 if (table->tab[i])
 369                         hw_stats->stats.xstats[i] = &table->tab[i]->stats;
 370
 371         ret = qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_GRED, hw_stats);
 372         /* Even if driver returns failure adjust the stats - in case offload
 373          * ended but driver still wants to adjust the values.
 374          */
 375         for (i = 0; i < MAX_DPs; i++) {
 376                 if (!table->tab[i])
 377                         continue;
 378                 table->tab[i]->packetsin += hw_stats->stats.bstats[i].packets;
 379                 table->tab[i]->bytesin += hw_stats->stats.bstats[i].bytes;
 380                 table->tab[i]->backlog += hw_stats->stats.qstats[i].backlog;
 381
 382                 _bstats_update(&sch->bstats,
 383                                hw_stats->stats.bstats[i].bytes,
 384                                hw_stats->stats.bstats[i].packets);
 385                 sch->qstats.qlen += hw_stats->stats.qstats[i].qlen;
 386                 sch->qstats.backlog += hw_stats->stats.qstats[i].backlog;
 387                 sch->qstats.drops += hw_stats->stats.qstats[i].drops;
 388                 sch->qstats.requeues += hw_stats->stats.qstats[i].requeues;
 389                 sch->qstats.overlimits += hw_stats->stats.qstats[i].overlimits;
 390         }
 391
 392         kfree(hw_stats);
 393         return ret;
 394 }
 395
 396 static inline void gred_destroy_vq(struct gred_sched_data *q)
 397 {
 398         kfree(q);
 399 }
 400
 401 static int gred_change_table_def(struct Qdisc *sch, struct nlattr *dps,
 402                                  struct netlink_ext_ack *extack)
 403 {
 404         struct gred_sched *table = qdisc_priv(sch);
 405         struct tc_gred_sopt *sopt;
 406         bool red_flags_changed;
 407         int i;
 408
 409         if (!dps)
 410                 return -EINVAL;
 411
 412         sopt = nla_data(dps);
 413
 414         if (sopt->DPs > MAX_DPs) {
 415                 NL_SET_ERR_MSG_MOD(extack, "number of virtual queues too high");
 416                 return -EINVAL;
 417         }
 418         if (sopt->DPs == 0) {
 419                 NL_SET_ERR_MSG_MOD(extack,
 420                                    "number of virtual queues can't be 0");
 421                 return -EINVAL;
 422         }
 423         if (sopt->def_DP >= sopt->DPs) {
 424                 NL_SET_ERR_MSG_MOD(extack, "default virtual queue above virtual queue count");
 425                 return -EINVAL;
 426         }
 427         if (sopt->flags && gred_per_vq_red_flags_used(table)) {
 428                 NL_SET_ERR_MSG_MOD(extack, "can't set per-Qdisc RED flags when per-virtual queue flags are used");
 429                 return -EINVAL;
 430         }
 431
 432         sch_tree_lock(sch);
 433         table->DPs = sopt->DPs;
 434         table->def = sopt->def_DP;
 435         red_flags_changed = table->red_flags != sopt->flags;
 436         table->red_flags = sopt->flags;
 437
 438         /*
 439          * Every entry point to GRED is synchronized with the above code
 440          * and the DP is checked against DPs, i.e. shadowed VQs can no
 441          * longer be found so we can unlock right here.
 442          */
 443         sch_tree_unlock(sch);
 444
 445         if (sopt->grio) {
 446                 gred_enable_rio_mode(table);
 447                 gred_disable_wred_mode(table);
 448                 if (gred_wred_mode_check(sch))
 449                         gred_enable_wred_mode(table);
 450         } else {
 451                 gred_disable_rio_mode(table);
 452                 gred_disable_wred_mode(table);
 453         }
 454
 455         if (red_flags_changed)
 456                 for (i = 0; i < table->DPs; i++)
 457                         if (table->tab[i])
 458                                 table->tab[i]->red_flags =
 459                                         table->red_flags & GRED_VQ_RED_FLAGS;
 460
 461         for (i = table->DPs; i < MAX_DPs; i++) {
 462                 if (table->tab[i]) {
 463                         pr_warn("GRED: Warning: Destroying shadowed VQ 0x%x\n",
 464                                 i);
 465                         gred_destroy_vq(table->tab[i]);
 466                         table->tab[i] = NULL;
 467                 }
 468         }
 469
 470         gred_offload(sch, TC_GRED_REPLACE);
 471         return 0;
 472 }
 473
 474 static inline int gred_change_vq(struct Qdisc *sch, int dp,
 475                                  struct tc_gred_qopt *ctl, int prio,
 476                                  u8 *stab, u32 max_P,
 477                                  struct gred_sched_data **prealloc,
 478                                  struct netlink_ext_ack *extack)
 479 {
 480         struct gred_sched *table = qdisc_priv(sch);
 481         struct gred_sched_data *q = table->tab[dp];
 482
 483         if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog)) {
 484                 NL_SET_ERR_MSG_MOD(extack, "invalid RED parameters");
 485                 return -EINVAL;
 486         }
 487
 488         if (!q) {
 489                 table->tab[dp] = q = *prealloc;
 490                 *prealloc = NULL;
 491                 if (!q)
 492                         return -ENOMEM;
 493                 q->red_flags = table->red_flags & GRED_VQ_RED_FLAGS;
 494         }
 495
 496         q->DP = dp;
 497         q->prio = prio;
 498         if (ctl->limit > sch->limit)
 499                 q->limit = sch->limit;
 500         else
 501                 q->limit = ctl->limit;
 502
 503         if (q->backlog == 0)
 504                 red_end_of_idle_period(&q->vars);
 505
 506         red_set_parms(&q->parms,
 507                       ctl->qth_min, ctl->qth_max, ctl->Wlog, ctl->Plog,
 508                       ctl->Scell_log, stab, max_P);
 509         red_set_vars(&q->vars);
 510         return 0;
 511 }
 512
 513 static const struct nla_policy gred_vq_policy[TCA_GRED_VQ_MAX + 1] = {
 514         [TCA_GRED_VQ_DP]        = { .type = NLA_U32 },
 515         [TCA_GRED_VQ_FLAGS]     = { .type = NLA_U32 },
 516 };
 517
 518 static const struct nla_policy gred_vqe_policy[TCA_GRED_VQ_ENTRY_MAX + 1] = {
 519         [TCA_GRED_VQ_ENTRY]     = { .type = NLA_NESTED },
 520 };
 521
 522 static const struct nla_policy gred_policy[TCA_GRED_MAX + 1] = {
 523         [TCA_GRED_PARMS]        = { .len = sizeof(struct tc_gred_qopt) },
 524         [TCA_GRED_STAB]         = { .len = 256 },
 525         [TCA_GRED_DPS]          = { .len = sizeof(struct tc_gred_sopt) },
 526         [TCA_GRED_MAX_P]        = { .type = NLA_U32 },
 527         [TCA_GRED_LIMIT]        = { .type = NLA_U32 },
 528         [TCA_GRED_VQ_LIST]      = { .type = NLA_NESTED },
 529 };
 530
 531 static void gred_vq_apply(struct gred_sched *table, const struct nlattr *entry)
 532 {
 533         struct nlattr *tb[TCA_GRED_VQ_MAX + 1];
 534         u32 dp;
 535
 536         nla_parse_nested_deprecated(tb, TCA_GRED_VQ_MAX, entry,
 537                                     gred_vq_policy, NULL);
 538
 539         dp = nla_get_u32(tb[TCA_GRED_VQ_DP]);
 540
 541         if (tb[TCA_GRED_VQ_FLAGS])
 542                 table->tab[dp]->red_flags = nla_get_u32(tb[TCA_GRED_VQ_FLAGS]);
 543 }
 544
 545 static void gred_vqs_apply(struct gred_sched *table, struct nlattr *vqs)
 546 {
 547         const struct nlattr *attr;
 548         int rem;
 549
 550         nla_for_each_nested(attr, vqs, rem) {
 551                 switch (nla_type(attr)) {
 552                 case TCA_GRED_VQ_ENTRY:
 553                         gred_vq_apply(table, attr);
 554                         break;
 555                 }
 556         }
 557 }
 558
 559 static int gred_vq_validate(struct gred_sched *table, u32 cdp,
 560                             const struct nlattr *entry,
 561                             struct netlink_ext_ack *extack)
 562 {
 563         struct nlattr *tb[TCA_GRED_VQ_MAX + 1];
 564         int err;
 565         u32 dp;
 566
 567         err = nla_parse_nested_deprecated(tb, TCA_GRED_VQ_MAX, entry,
 568                                           gred_vq_policy, extack);
 569         if (err < 0)
 570                 return err;
 571
 572         if (!tb[TCA_GRED_VQ_DP]) {
 573                 NL_SET_ERR_MSG_MOD(extack, "Virtual queue with no index specified");
 574                 return -EINVAL;
 575         }
 576         dp = nla_get_u32(tb[TCA_GRED_VQ_DP]);
 577         if (dp >= table->DPs) {
 578                 NL_SET_ERR_MSG_MOD(extack, "Virtual queue with index out of bounds");
 579                 return -EINVAL;
 580         }
 581         if (dp != cdp && !table->tab[dp]) {
 582                 NL_SET_ERR_MSG_MOD(extack, "Virtual queue not yet instantiated");
 583                 return -EINVAL;
 584         }
 585
 586         if (tb[TCA_GRED_VQ_FLAGS]) {
 587                 u32 red_flags = nla_get_u32(tb[TCA_GRED_VQ_FLAGS]);
 588
 589                 if (table->red_flags && table->red_flags != red_flags) {
 590                         NL_SET_ERR_MSG_MOD(extack, "can't change per-virtual queue RED flags when per-Qdisc flags are used");
 591                         return -EINVAL;
 592                 }
 593                 if (red_flags & ~GRED_VQ_RED_FLAGS) {
 594                         NL_SET_ERR_MSG_MOD(extack,
 595                                            "invalid RED flags specified");
 596                         return -EINVAL;
 597                 }
 598         }
 599
 600         return 0;
 601 }
 602
 603 static int gred_vqs_validate(struct gred_sched *table, u32 cdp,
 604                              struct nlattr *vqs, struct netlink_ext_ack *extack)
 605 {
 606         const struct nlattr *attr;
 607         int rem, err;
 608
 609         err = nla_validate_nested_deprecated(vqs, TCA_GRED_VQ_ENTRY_MAX,
 610                                              gred_vqe_policy, extack);
 611         if (err < 0)
 612                 return err;
 613
 614         nla_for_each_nested(attr, vqs, rem) {
 615                 switch (nla_type(attr)) {
 616                 case TCA_GRED_VQ_ENTRY:
 617                         err = gred_vq_validate(table, cdp, attr, extack);
 618                         if (err)
 619                                 return err;
 620                         break;
 621                 default:
 622                         NL_SET_ERR_MSG_MOD(extack, "GRED_VQ_LIST can contain only entry attributes");
 623                         return -EINVAL;
 624                 }
 625         }
 626
 627         if (rem > 0) {
 628                 NL_SET_ERR_MSG_MOD(extack, "Trailing data after parsing virtual queue list");
 629                 return -EINVAL;
 630         }
 631
 632         return 0;
 633 }
 634
 635 static int gred_change(struct Qdisc *sch, struct nlattr *opt,
 636                        struct netlink_ext_ack *extack)
 637 {
 638         struct gred_sched *table = qdisc_priv(sch);
 639         struct tc_gred_qopt *ctl;
 640         struct nlattr *tb[TCA_GRED_MAX + 1];
 641         int err, prio = GRED_DEF_PRIO;
 642         u8 *stab;
 643         u32 max_P;
 644         struct gred_sched_data *prealloc;
 645
 646         if (opt == NULL)
 647                 return -EINVAL;
 648
 649         err = nla_parse_nested_deprecated(tb, TCA_GRED_MAX, opt, gred_policy,
 650                                           extack);
 651         if (err < 0)
 652                 return err;
 653
 654         if (tb[TCA_GRED_PARMS] == NULL && tb[TCA_GRED_STAB] == NULL) {
 655                 if (tb[TCA_GRED_LIMIT] != NULL)
 656                         sch->limit = nla_get_u32(tb[TCA_GRED_LIMIT]);
 657                 return gred_change_table_def(sch, tb[TCA_GRED_DPS], extack);
 658         }
 659
 660         if (tb[TCA_GRED_PARMS] == NULL ||
 661             tb[TCA_GRED_STAB] == NULL ||
 662             tb[TCA_GRED_LIMIT] != NULL) {
 663                 NL_SET_ERR_MSG_MOD(extack, "can't configure Qdisc and virtual queue at the same time");
 664                 return -EINVAL;
 665         }
 666
 667         max_P = tb[TCA_GRED_MAX_P] ? nla_get_u32(tb[TCA_GRED_MAX_P]) : 0;
 668
 669         ctl = nla_data(tb[TCA_GRED_PARMS]);
 670         stab = nla_data(tb[TCA_GRED_STAB]);
 671
 672         if (ctl->DP >= table->DPs) {
 673                 NL_SET_ERR_MSG_MOD(extack, "virtual queue index above virtual queue count");
 674                 return -EINVAL;
 675         }
 676
 677         if (tb[TCA_GRED_VQ_LIST]) {
 678                 err = gred_vqs_validate(table, ctl->DP, tb[TCA_GRED_VQ_LIST],
 679                                         extack);
 680                 if (err)
 681                         return err;
 682         }
 683
 684         if (gred_rio_mode(table)) {
 685                 if (ctl->prio == 0) {
 686                         int def_prio = GRED_DEF_PRIO;
 687
 688                         if (table->tab[table->def])
 689                                 def_prio = table->tab[table->def]->prio;
 690
 691                         printk(KERN_DEBUG "GRED: DP %u does not have a prio "
 692                                "setting default to %d\n", ctl->DP, def_prio);
 693
 694                         prio = def_prio;
 695                 } else
 696                         prio = ctl->prio;
 697         }
 698
 699         prealloc = kzalloc(sizeof(*prealloc), GFP_KERNEL);
 700         sch_tree_lock(sch);
 701
 702         err = gred_change_vq(sch, ctl->DP, ctl, prio, stab, max_P, &prealloc,
 703                              extack);
 704         if (err < 0)
 705                 goto err_unlock_free;
 706
 707         if (tb[TCA_GRED_VQ_LIST])
 708                 gred_vqs_apply(table, tb[TCA_GRED_VQ_LIST]);
 709
 710         if (gred_rio_mode(table)) {
 711                 gred_disable_wred_mode(table);
 712                 if (gred_wred_mode_check(sch))
 713                         gred_enable_wred_mode(table);
 714         }
 715
 716         sch_tree_unlock(sch);
 717         kfree(prealloc);
 718
 719         gred_offload(sch, TC_GRED_REPLACE);
 720         return 0;
 721
 722 err_unlock_free:
 723         sch_tree_unlock(sch);
 724         kfree(prealloc);
 725         return err;
 726 }
 727
 728 static int gred_init(struct Qdisc *sch, struct nlattr *opt,
 729                      struct netlink_ext_ack *extack)
 730 {
 731         struct nlattr *tb[TCA_GRED_MAX + 1];
 732         int err;
 733
 734         if (!opt)
 735                 return -EINVAL;
 736
 737         err = nla_parse_nested_deprecated(tb, TCA_GRED_MAX, opt, gred_policy,
 738                                           extack);
 739         if (err < 0)
 740                 return err;
 741
 742         if (tb[TCA_GRED_PARMS] || tb[TCA_GRED_STAB]) {
 743                 NL_SET_ERR_MSG_MOD(extack,
 744                                    "virtual queue configuration can't be specified at initialization time");
 745                 return -EINVAL;
 746         }
 747
 748         if (tb[TCA_GRED_LIMIT])
 749                 sch->limit = nla_get_u32(tb[TCA_GRED_LIMIT]);
 750         else
 751                 sch->limit = qdisc_dev(sch)->tx_queue_len
 752                              * psched_mtu(qdisc_dev(sch));
 753
 754         return gred_change_table_def(sch, tb[TCA_GRED_DPS], extack);
 755 }
 756
 757 static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
 758 {
 759         struct gred_sched *table = qdisc_priv(sch);
 760         struct nlattr *parms, *vqs, *opts = NULL;
 761         int i;
 762         u32 max_p[MAX_DPs];
 763         struct tc_gred_sopt sopt = {
 764                 .DPs    = table->DPs,
 765                 .def_DP = table->def,
 766                 .grio   = gred_rio_mode(table),
 767                 .flags  = table->red_flags,
 768         };
 769
 770         if (gred_offload_dump_stats(sch))
 771                 goto nla_put_failure;
 772
 773         opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
 774         if (opts == NULL)
 775                 goto nla_put_failure;
 776         if (nla_put(skb, TCA_GRED_DPS, sizeof(sopt), &sopt))
 777                 goto nla_put_failure;
 778
 779         for (i = 0; i < MAX_DPs; i++) {
 780                 struct gred_sched_data *q = table->tab[i];
 781
 782                 max_p[i] = q ? q->parms.max_P : 0;
 783         }
 784         if (nla_put(skb, TCA_GRED_MAX_P, sizeof(max_p), max_p))
 785                 goto nla_put_failure;
 786
 787         if (nla_put_u32(skb, TCA_GRED_LIMIT, sch->limit))
 788                 goto nla_put_failure;
 789
 790         /* Old style all-in-one dump of VQs */
 791         parms = nla_nest_start_noflag(skb, TCA_GRED_PARMS);
 792         if (parms == NULL)
 793                 goto nla_put_failure;
 794
 795         for (i = 0; i < MAX_DPs; i++) {
 796                 struct gred_sched_data *q = table->tab[i];
 797                 struct tc_gred_qopt opt;
 798                 unsigned long qavg;
 799
 800                 memset(&opt, 0, sizeof(opt));
 801
 802                 if (!q) {
 803                         /* hack -- fix at some point with proper message
 804                            This is how we indicate to tc that there is no VQ
 805                            at this DP */
 806
 807                         opt.DP = MAX_DPs + i;
 808                         goto append_opt;
 809                 }
 810
 811                 opt.limit       = q->limit;
 812                 opt.DP          = q->DP;
 813                 opt.backlog     = gred_backlog(table, q, sch);
 814                 opt.prio        = q->prio;
 815                 opt.qth_min     = q->parms.qth_min >> q->parms.Wlog;
 816                 opt.qth_max     = q->parms.qth_max >> q->parms.Wlog;
 817                 opt.Wlog        = q->parms.Wlog;
 818                 opt.Plog        = q->parms.Plog;
 819                 opt.Scell_log   = q->parms.Scell_log;
 820                 opt.other       = q->stats.other;
 821                 opt.early       = q->stats.prob_drop;
 822                 opt.forced      = q->stats.forced_drop;
 823                 opt.pdrop       = q->stats.pdrop;
 824                 opt.packets     = q->packetsin;
 825                 opt.bytesin     = q->bytesin;
 826
 827                 if (gred_wred_mode(table))
 828                         gred_load_wred_set(table, q);
 829
 830                 qavg = red_calc_qavg(&q->parms, &q->vars,
 831                                      q->vars.qavg >> q->parms.Wlog);
 832                 opt.qave = qavg >> q->parms.Wlog;
 833
 834 append_opt:
 835                 if (nla_append(skb, sizeof(opt), &opt) < 0)
 836                         goto nla_put_failure;
 837         }
 838
 839         nla_nest_end(skb, parms);
 840
 841         /* Dump the VQs again, in more structured way */
 842         vqs = nla_nest_start_noflag(skb, TCA_GRED_VQ_LIST);
 843         if (!vqs)
 844                 goto nla_put_failure;
 845
 846         for (i = 0; i < MAX_DPs; i++) {
 847                 struct gred_sched_data *q = table->tab[i];
 848                 struct nlattr *vq;
 849
 850                 if (!q)
 851                         continue;
 852
 853                 vq = nla_nest_start_noflag(skb, TCA_GRED_VQ_ENTRY);
 854                 if (!vq)
 855                         goto nla_put_failure;
 856
 857                 if (nla_put_u32(skb, TCA_GRED_VQ_DP, q->DP))
 858                         goto nla_put_failure;
 859
 860                 if (nla_put_u32(skb, TCA_GRED_VQ_FLAGS, q->red_flags))
 861                         goto nla_put_failure;
 862
 863                 /* Stats */
 864                 if (nla_put_u64_64bit(skb, TCA_GRED_VQ_STAT_BYTES, q->bytesin,
 865                                       TCA_GRED_VQ_PAD))
 866                         goto nla_put_failure;
 867                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PACKETS, q->packetsin))
 868                         goto nla_put_failure;
 869                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_BACKLOG,
 870                                 gred_backlog(table, q, sch)))
 871                         goto nla_put_failure;
 872                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PROB_DROP,
 873                                 q->stats.prob_drop))
 874                         goto nla_put_failure;
 875                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PROB_MARK,
 876                                 q->stats.prob_mark))
 877                         goto nla_put_failure;
 878                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_FORCED_DROP,
 879                                 q->stats.forced_drop))
 880                         goto nla_put_failure;
 881                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_FORCED_MARK,
 882                                 q->stats.forced_mark))
 883                         goto nla_put_failure;
 884                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_PDROP, q->stats.pdrop))
 885                         goto nla_put_failure;
 886                 if (nla_put_u32(skb, TCA_GRED_VQ_STAT_OTHER, q->stats.other))
 887                         goto nla_put_failure;
 888
 889                 nla_nest_end(skb, vq);
 890         }
 891         nla_nest_end(skb, vqs);
 892
 893         return nla_nest_end(skb, opts);
 894
 895 nla_put_failure:
 896         nla_nest_cancel(skb, opts);
 897         return -EMSGSIZE;
 898 }
 899
 900 static void gred_destroy(struct Qdisc *sch)
 901 {
 902         struct gred_sched *table = qdisc_priv(sch);
 903         int i;
 904
 905         for (i = 0; i < table->DPs; i++) {
 906                 if (table->tab[i])
 907                         gred_destroy_vq(table->tab[i]);
 908         }
 909         gred_offload(sch, TC_GRED_DESTROY);
 910 }
 911
 912 static struct Qdisc_ops gred_qdisc_ops __read_mostly = {
 913         .id             =       "gred",
 914         .priv_size      =       sizeof(struct gred_sched),
 915         .enqueue        =       gred_enqueue,
 916         .dequeue        =       gred_dequeue,
 917         .peek           =       qdisc_peek_head,
 918         .init           =       gred_init,
 919         .reset          =       gred_reset,
 920         .destroy        =       gred_destroy,
 921         .change         =       gred_change,
 922         .dump           =       gred_dump,
 923         .owner          =       THIS_MODULE,
 924 };
 925
 926 static int __init gred_module_init(void)
 927 {
 928         return register_qdisc(&gred_qdisc_ops);
 929 }
 930
 931 static void __exit gred_module_exit(void)
 932 {
 933         unregister_qdisc(&gred_qdisc_ops);
 934 }
 935
 936 module_init(gred_module_init)
 937 module_exit(gred_module_exit)
 938
 939 MODULE_LICENSE("GPL");