net/mac80211/wme.c

   1 /*
   2  * Copyright 2004, Instant802 Networks, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/netdevice.h>
  10 #include <linux/skbuff.h>
  11 #include <linux/module.h>
  12 #include <linux/if_arp.h>
  13 #include <linux/types.h>
  14 #include <net/ip.h>
  15 #include <net/pkt_sched.h>
  16
  17 #include <net/mac80211.h>
  18 #include "ieee80211_i.h"
  19 #include "wme.h"
  20
  21 /* maximum number of hardware queues we support. */
  22 #define TC_80211_MAX_QUEUES 8
  23
  24 struct ieee80211_sched_data
  25 {
  26         struct tcf_proto *filter_list;
  27         struct Qdisc *queues[TC_80211_MAX_QUEUES];
  28         struct sk_buff_head requeued[TC_80211_MAX_QUEUES];
  29 };
  30
  31
  32 /* given a data frame determine the 802.1p/1d tag to use */
  33 static inline unsigned classify_1d(struct sk_buff *skb, struct Qdisc *qd)
  34 {
  35         struct iphdr *ip;
  36         int dscp;
  37         int offset;
  38
  39         struct ieee80211_sched_data *q = qdisc_priv(qd);
  40         struct tcf_result res = { -1, 0 };
  41
  42         /* if there is a user set filter list, call out to that */
  43         if (q->filter_list) {
  44                 tc_classify(skb, q->filter_list, &res);
  45                 if (res.class != -1)
  46                         return res.class;
  47         }
  48
  49         /* skb->priority values from 256->263 are magic values to
  50          * directly indicate a specific 802.1d priority.
  51          * This is used to allow 802.1d priority to be passed directly in
  52          * from VLAN tags, etc. */
  53         if (skb->priority >= 256 && skb->priority <= 263)
  54                 return skb->priority - 256;
  55
  56         /* check there is a valid IP header present */
  57         offset = ieee80211_get_hdrlen_from_skb(skb) + 8 /* LLC + proto */;
  58         if (skb->protocol != __constant_htons(ETH_P_IP) ||
  59             skb->len < offset + sizeof(*ip))
  60                 return 0;
  61
  62         ip = (struct iphdr *) (skb->data + offset);
  63
  64         dscp = ip->tos & 0xfc;
  65         if (dscp & 0x1c)
  66                 return 0;
  67         return dscp >> 5;
  68 }
  69
  70
  71 static inline int wme_downgrade_ac(struct sk_buff *skb)
  72 {
  73         switch (skb->priority) {
  74         case 6:
  75         case 7:
  76                 skb->priority = 5; /* VO -> VI */
  77                 return 0;
  78         case 4:
  79         case 5:
  80                 skb->priority = 3; /* VI -> BE */
  81                 return 0;
  82         case 0:
  83         case 3:
  84                 skb->priority = 2; /* BE -> BK */
  85                 return 0;
  86         default:
  87                 return -1;
  88         }
  89 }
  90
  91
  92 /* positive return value indicates which queue to use
  93  * negative return value indicates to drop the frame */
  94 static inline int classify80211(struct sk_buff *skb, struct Qdisc *qd)
  95 {
  96         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
  97         struct ieee80211_tx_packet_data *pkt_data =
  98                 (struct ieee80211_tx_packet_data *) skb->cb;
  99         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 100         unsigned short fc = le16_to_cpu(hdr->frame_control);
 101         int qos;
 102         const int ieee802_1d_to_ac[8] = { 2, 3, 3, 2, 1, 1, 0, 0 };
 103
 104         /* see if frame is data or non data frame */
 105         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)) {
 106                 /* management frames go on AC_VO queue, but are sent
 107                 * without QoS control fields */
 108                 return IEEE80211_TX_QUEUE_DATA0;
 109         }
 110
 111         if (unlikely(pkt_data->flags & IEEE80211_TXPD_MGMT_IFACE)) {
 112                 /* Data frames from hostapd (mainly, EAPOL) use AC_VO
 113                 * and they will include QoS control fields if
 114                 * the target STA is using WME. */
 115                 skb->priority = 7;
 116                 return ieee802_1d_to_ac[skb->priority];
 117         }
 118
 119         /* is this a QoS frame? */
 120         qos = fc & IEEE80211_STYPE_QOS_DATA;
 121
 122         if (!qos) {
 123                 skb->priority = 0; /* required for correct WPA/11i MIC */
 124                 return ieee802_1d_to_ac[skb->priority];
 125         }
 126
 127         /* use the data classifier to determine what 802.1d tag the
 128          * data frame has */
 129         skb->priority = classify_1d(skb, qd);
 130
 131         /* in case we are a client verify acm is not set for this ac */
 132         while (unlikely(local->wmm_acm & BIT(skb->priority))) {
 133                 if (wme_downgrade_ac(skb)) {
 134                         /* No AC with lower priority has acm=0, drop packet. */
 135                         return -1;
 136                 }
 137         }
 138
 139         /* look up which queue to use for frames with this 1d tag */
 140         return ieee802_1d_to_ac[skb->priority];
 141 }
 142
 143
 144 static int wme_qdiscop_enqueue(struct sk_buff *skb, struct Qdisc* qd)
 145 {
 146         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 147         struct ieee80211_sched_data *q = qdisc_priv(qd);
 148         struct ieee80211_tx_packet_data *pkt_data =
 149                 (struct ieee80211_tx_packet_data *) skb->cb;
 150         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 151         unsigned short fc = le16_to_cpu(hdr->frame_control);
 152         struct Qdisc *qdisc;
 153         int err, queue;
 154
 155         if (pkt_data->flags & IEEE80211_TXPD_REQUEUE) {
 156                 skb_queue_tail(&q->requeued[pkt_data->queue], skb);
 157                 qd->q.qlen++;
 158                 return 0;
 159         }
 160
 161         queue = classify80211(skb, qd);
 162
 163         /* now we know the 1d priority, fill in the QoS header if there is one
 164          */
 165         if (WLAN_FC_IS_QOS_DATA(fc)) {
 166                 u8 *p = skb->data + ieee80211_get_hdrlen(fc) - 2;
 167                 u8 qos_hdr = skb->priority & QOS_CONTROL_TAG1D_MASK;
 168                 if (local->wifi_wme_noack_test)
 169                         qos_hdr |= QOS_CONTROL_ACK_POLICY_NOACK <<
 170                                         QOS_CONTROL_ACK_POLICY_SHIFT;
 171                 /* qos header is 2 bytes, second reserved */
 172                 *p = qos_hdr;
 173                 p++;
 174                 *p = 0;
 175         }
 176
 177         if (unlikely(queue >= local->hw.queues)) {
 178 #if 0
 179                 if (net_ratelimit()) {
 180                         printk(KERN_DEBUG "%s - queue=%d (hw does not "
 181                                "support) -> %d\n",
 182                                __func__, queue, local->hw.queues - 1);
 183                 }
 184 #endif
 185                 queue = local->hw.queues - 1;
 186         }
 187
 188         if (unlikely(queue < 0)) {
 189                         kfree_skb(skb);
 190                         err = NET_XMIT_DROP;
 191         } else {
 192                 pkt_data->queue = (unsigned int) queue;
 193                 qdisc = q->queues[queue];
 194                 err = qdisc->enqueue(skb, qdisc);
 195                 if (err == NET_XMIT_SUCCESS) {
 196                         qd->q.qlen++;
 197                         qd->bstats.bytes += skb->len;
 198                         qd->bstats.packets++;
 199                         return NET_XMIT_SUCCESS;
 200                 }
 201         }
 202         qd->qstats.drops++;
 203         return err;
 204 }
 205
 206
 207 /* TODO: clean up the cases where master_hard_start_xmit
 208  * returns non 0 - it shouldn't ever do that. Once done we
 209  * can remove this function */
 210 static int wme_qdiscop_requeue(struct sk_buff *skb, struct Qdisc* qd)
 211 {
 212         struct ieee80211_sched_data *q = qdisc_priv(qd);
 213         struct ieee80211_tx_packet_data *pkt_data =
 214                 (struct ieee80211_tx_packet_data *) skb->cb;
 215         struct Qdisc *qdisc;
 216         int err;
 217
 218         /* we recorded which queue to use earlier! */
 219         qdisc = q->queues[pkt_data->queue];
 220
 221         if ((err = qdisc->ops->requeue(skb, qdisc)) == 0) {
 222                 qd->q.qlen++;
 223                 return 0;
 224         }
 225         qd->qstats.drops++;
 226         return err;
 227 }
 228
 229
 230 static struct sk_buff *wme_qdiscop_dequeue(struct Qdisc* qd)
 231 {
 232         struct ieee80211_sched_data *q = qdisc_priv(qd);
 233         struct net_device *dev = qd->dev;
 234         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 235         struct ieee80211_hw *hw = &local->hw;
 236         struct sk_buff *skb;
 237         struct Qdisc *qdisc;
 238         int queue;
 239
 240         /* check all the h/w queues in numeric/priority order */
 241         for (queue = 0; queue < hw->queues; queue++) {
 242                 /* see if there is room in this hardware queue */
 243                 if (test_bit(IEEE80211_LINK_STATE_XOFF,
 244                              &local->state[queue]) ||
 245                     test_bit(IEEE80211_LINK_STATE_PENDING,
 246                              &local->state[queue]))
 247                         continue;
 248
 249                 /* there is space - try and get a frame */
 250                 skb = skb_dequeue(&q->requeued[queue]);
 251                 if (skb) {
 252                         qd->q.qlen--;
 253                         return skb;
 254                 }
 255
 256                 qdisc = q->queues[queue];
 257                 skb = qdisc->dequeue(qdisc);
 258                 if (skb) {
 259                         qd->q.qlen--;
 260                         return skb;
 261                 }
 262         }
 263         /* returning a NULL here when all the h/w queues are full means we
 264          * never need to call netif_stop_queue in the driver */
 265         return NULL;
 266 }
 267
 268
 269 static void wme_qdiscop_reset(struct Qdisc* qd)
 270 {
 271         struct ieee80211_sched_data *q = qdisc_priv(qd);
 272         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 273         struct ieee80211_hw *hw = &local->hw;
 274         int queue;
 275
 276         /* QUESTION: should we have some hardware flush functionality here? */
 277
 278         for (queue = 0; queue < hw->queues; queue++) {
 279                 skb_queue_purge(&q->requeued[queue]);
 280                 qdisc_reset(q->queues[queue]);
 281         }
 282         qd->q.qlen = 0;
 283 }
 284
 285
 286 static void wme_qdiscop_destroy(struct Qdisc* qd)
 287 {
 288         struct ieee80211_sched_data *q = qdisc_priv(qd);
 289         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 290         struct ieee80211_hw *hw = &local->hw;
 291         int queue;
 292
 293         tcf_destroy_chain(q->filter_list);
 294         q->filter_list = NULL;
 295
 296         for (queue=0; queue < hw->queues; queue++) {
 297                 skb_queue_purge(&q->requeued[queue]);
 298                 qdisc_destroy(q->queues[queue]);
 299                 q->queues[queue] = &noop_qdisc;
 300         }
 301 }
 302
 303
 304 /* called whenever parameters are updated on existing qdisc */
 305 static int wme_qdiscop_tune(struct Qdisc *qd, struct rtattr *opt)
 306 {
 307 /*      struct ieee80211_sched_data *q = qdisc_priv(qd);
 308 */
 309         /* check our options block is the right size */
 310         /* copy any options to our local structure */
 311 /*      Ignore options block for now - always use static mapping
 312         struct tc_ieee80211_qopt *qopt = RTA_DATA(opt);
 313
 314         if (opt->rta_len < RTA_LENGTH(sizeof(*qopt)))
 315                 return -EINVAL;
 316         memcpy(q->tag2queue, qopt->tag2queue, sizeof(qopt->tag2queue));
 317 */
 318         return 0;
 319 }
 320
 321
 322 /* called during initial creation of qdisc on device */
 323 static int wme_qdiscop_init(struct Qdisc *qd, struct rtattr *opt)
 324 {
 325         struct ieee80211_sched_data *q = qdisc_priv(qd);
 326         struct net_device *dev = qd->dev;
 327         struct ieee80211_local *local;
 328         int queues;
 329         int err = 0, i;
 330
 331         /* check that device is a mac80211 device */
 332         if (!dev->ieee80211_ptr ||
 333             dev->ieee80211_ptr->wiphy->privid != mac80211_wiphy_privid)
 334                 return -EINVAL;
 335
 336         /* check this device is an ieee80211 master type device */
 337         if (dev->type != ARPHRD_IEEE80211)
 338                 return -EINVAL;
 339
 340         /* check that there is no qdisc currently attached to device
 341          * this ensures that we will be the root qdisc. (I can't find a better
 342          * way to test this explicitly) */
 343         if (dev->qdisc_sleeping != &noop_qdisc)
 344                 return -EINVAL;
 345
 346         if (qd->flags & TCQ_F_INGRESS)
 347                 return -EINVAL;
 348
 349         local = wdev_priv(dev->ieee80211_ptr);
 350         queues = local->hw.queues;
 351
 352         /* if options were passed in, set them */
 353         if (opt) {
 354                 err = wme_qdiscop_tune(qd, opt);
 355         }
 356
 357         /* create child queues */
 358         for (i = 0; i < queues; i++) {
 359                 skb_queue_head_init(&q->requeued[i]);
 360                 q->queues[i] = qdisc_create_dflt(qd->dev, &pfifo_qdisc_ops,
 361                                                  qd->handle);
 362                 if (!q->queues[i]) {
 363                         q->queues[i] = &noop_qdisc;
 364                         printk(KERN_ERR "%s child qdisc %i creation failed", dev->name, i);
 365                 }
 366         }
 367
 368         return err;
 369 }
 370
 371 static int wme_qdiscop_dump(struct Qdisc *qd, struct sk_buff *skb)
 372 {
 373 /*      struct ieee80211_sched_data *q = qdisc_priv(qd);
 374         unsigned char *p = skb->tail;
 375         struct tc_ieee80211_qopt opt;
 376
 377         memcpy(&opt.tag2queue, q->tag2queue, TC_80211_MAX_TAG + 1);
 378         RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
 379 */      return skb->len;
 380 /*
 381 rtattr_failure:
 382         skb_trim(skb, p - skb->data);*/
 383         return -1;
 384 }
 385
 386
 387 static int wme_classop_graft(struct Qdisc *qd, unsigned long arg,
 388                              struct Qdisc *new, struct Qdisc **old)
 389 {
 390         struct ieee80211_sched_data *q = qdisc_priv(qd);
 391         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 392         struct ieee80211_hw *hw = &local->hw;
 393         unsigned long queue = arg - 1;
 394
 395         if (queue >= hw->queues)
 396                 return -EINVAL;
 397
 398         if (!new)
 399                 new = &noop_qdisc;
 400
 401         sch_tree_lock(qd);
 402         *old = q->queues[queue];
 403         q->queues[queue] = new;
 404         qdisc_reset(*old);
 405         sch_tree_unlock(qd);
 406
 407         return 0;
 408 }
 409
 410
 411 static struct Qdisc *
 412 wme_classop_leaf(struct Qdisc *qd, unsigned long arg)
 413 {
 414         struct ieee80211_sched_data *q = qdisc_priv(qd);
 415         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 416         struct ieee80211_hw *hw = &local->hw;
 417         unsigned long queue = arg - 1;
 418
 419         if (queue >= hw->queues)
 420                 return NULL;
 421
 422         return q->queues[queue];
 423 }
 424
 425
 426 static unsigned long wme_classop_get(struct Qdisc *qd, u32 classid)
 427 {
 428         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 429         struct ieee80211_hw *hw = &local->hw;
 430         unsigned long queue = TC_H_MIN(classid);
 431
 432         if (queue - 1 >= hw->queues)
 433                 return 0;
 434
 435         return queue;
 436 }
 437
 438
 439 static unsigned long wme_classop_bind(struct Qdisc *qd, unsigned long parent,
 440                                       u32 classid)
 441 {
 442         return wme_classop_get(qd, classid);
 443 }
 444
 445
 446 static void wme_classop_put(struct Qdisc *q, unsigned long cl)
 447 {
 448 }
 449
 450
 451 static int wme_classop_change(struct Qdisc *qd, u32 handle, u32 parent,
 452                               struct rtattr **tca, unsigned long *arg)
 453 {
 454         unsigned long cl = *arg;
 455         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 456         struct ieee80211_hw *hw = &local->hw;
 457
 458         if (cl - 1 > hw->queues)
 459                 return -ENOENT;
 460
 461         /* TODO: put code to program hardware queue parameters here,
 462          * to allow programming from tc command line */
 463
 464         return 0;
 465 }
 466
 467
 468 /* we don't support deleting hardware queues
 469  * when we add WMM-SA support - TSPECs may be deleted here */
 470 static int wme_classop_delete(struct Qdisc *qd, unsigned long cl)
 471 {
 472         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 473         struct ieee80211_hw *hw = &local->hw;
 474
 475         if (cl - 1 > hw->queues)
 476                 return -ENOENT;
 477         return 0;
 478 }
 479
 480
 481 static int wme_classop_dump_class(struct Qdisc *qd, unsigned long cl,
 482                                   struct sk_buff *skb, struct tcmsg *tcm)
 483 {
 484         struct ieee80211_sched_data *q = qdisc_priv(qd);
 485         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 486         struct ieee80211_hw *hw = &local->hw;
 487
 488         if (cl - 1 > hw->queues)
 489                 return -ENOENT;
 490         tcm->tcm_handle = TC_H_MIN(cl);
 491         tcm->tcm_parent = qd->handle;
 492         tcm->tcm_info = q->queues[cl-1]->handle; /* do we need this? */
 493         return 0;
 494 }
 495
 496
 497 static void wme_classop_walk(struct Qdisc *qd, struct qdisc_walker *arg)
 498 {
 499         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 500         struct ieee80211_hw *hw = &local->hw;
 501         int queue;
 502
 503         if (arg->stop)
 504                 return;
 505
 506         for (queue = 0; queue < hw->queues; queue++) {
 507                 if (arg->count < arg->skip) {
 508                         arg->count++;
 509                         continue;
 510                 }
 511                 /* we should return classids for our internal queues here
 512                  * as well as the external ones */
 513                 if (arg->fn(qd, queue+1, arg) < 0) {
 514                         arg->stop = 1;
 515                         break;
 516                 }
 517                 arg->count++;
 518         }
 519 }
 520
 521
 522 static struct tcf_proto ** wme_classop_find_tcf(struct Qdisc *qd,
 523                                                 unsigned long cl)
 524 {
 525         struct ieee80211_sched_data *q = qdisc_priv(qd);
 526
 527         if (cl)
 528                 return NULL;
 529
 530         return &q->filter_list;
 531 }
 532
 533
 534 /* this qdisc is classful (i.e. has classes, some of which may have leaf qdiscs attached)
 535  * - these are the operations on the classes */
 536 static struct Qdisc_class_ops class_ops =
 537 {
 538         .graft = wme_classop_graft,
 539         .leaf = wme_classop_leaf,
 540
 541         .get = wme_classop_get,
 542         .put = wme_classop_put,
 543         .change = wme_classop_change,
 544         .delete = wme_classop_delete,
 545         .walk = wme_classop_walk,
 546
 547         .tcf_chain = wme_classop_find_tcf,
 548         .bind_tcf = wme_classop_bind,
 549         .unbind_tcf = wme_classop_put,
 550
 551         .dump = wme_classop_dump_class,
 552 };
 553
 554
 555 /* queueing discipline operations */
 556 static struct Qdisc_ops wme_qdisc_ops =
 557 {
 558         .next = NULL,
 559         .cl_ops = &class_ops,
 560         .id = "ieee80211",
 561         .priv_size = sizeof(struct ieee80211_sched_data),
 562
 563         .enqueue = wme_qdiscop_enqueue,
 564         .dequeue = wme_qdiscop_dequeue,
 565         .requeue = wme_qdiscop_requeue,
 566         .drop = NULL, /* drop not needed since we are always the root qdisc */
 567
 568         .init = wme_qdiscop_init,
 569         .reset = wme_qdiscop_reset,
 570         .destroy = wme_qdiscop_destroy,
 571         .change = wme_qdiscop_tune,
 572
 573         .dump = wme_qdiscop_dump,
 574 };
 575
 576
 577 void ieee80211_install_qdisc(struct net_device *dev)
 578 {
 579         struct Qdisc *qdisc;
 580
 581         qdisc = qdisc_create_dflt(dev, &wme_qdisc_ops, TC_H_ROOT);
 582         if (!qdisc) {
 583                 printk(KERN_ERR "%s: qdisc installation failed\n", dev->name);
 584                 return;
 585         }
 586
 587         /* same handle as would be allocated by qdisc_alloc_handle() */
 588         qdisc->handle = 0x80010000;
 589
 590         qdisc_lock_tree(dev);
 591         list_add_tail(&qdisc->list, &dev->qdisc_list);
 592         dev->qdisc_sleeping = qdisc;
 593         qdisc_unlock_tree(dev);
 594 }
 595
 596
 597 int ieee80211_qdisc_installed(struct net_device *dev)
 598 {
 599         return dev->qdisc_sleeping->ops == &wme_qdisc_ops;
 600 }
 601
 602
 603 int ieee80211_wme_register(void)
 604 {
 605         return register_qdisc(&wme_qdisc_ops);
 606 }
 607
 608
 609 void ieee80211_wme_unregister(void)
 610 {
 611         unregister_qdisc(&wme_qdisc_ops);
 612 }