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 static const char llc_ip_hdr[8] = {0xAA, 0xAA, 0x3, 0, 0, 0, 0x08, 0};
  32
  33 /* given a data frame determine the 802.1p/1d tag to use */
  34 static inline unsigned classify_1d(struct sk_buff *skb, struct Qdisc *qd)
  35 {
  36         struct iphdr *ip;
  37         int dscp;
  38         int offset;
  39
  40         struct ieee80211_sched_data *q = qdisc_priv(qd);
  41         struct tcf_result res = { -1, 0 };
  42
  43         /* if there is a user set filter list, call out to that */
  44         if (q->filter_list) {
  45                 tc_classify(skb, q->filter_list, &res);
  46                 if (res.class != -1)
  47                         return res.class;
  48         }
  49
  50         /* skb->priority values from 256->263 are magic values to
  51          * directly indicate a specific 802.1d priority.
  52          * This is used to allow 802.1d priority to be passed directly in
  53          * from VLAN tags, etc. */
  54         if (skb->priority >= 256 && skb->priority <= 263)
  55                 return skb->priority - 256;
  56
  57         /* check there is a valid IP header present */
  58         offset = ieee80211_get_hdrlen_from_skb(skb);
  59         if (skb->len < offset + sizeof(llc_ip_hdr) + sizeof(*ip) ||
  60             memcmp(skb->data + offset, llc_ip_hdr, sizeof(llc_ip_hdr)))
  61                 return 0;
  62
  63         ip = (struct iphdr *) (skb->data + offset + sizeof(llc_ip_hdr));
  64
  65         dscp = ip->tos & 0xfc;
  66         if (dscp & 0x1c)
  67                 return 0;
  68         return dscp >> 5;
  69 }
  70
  71
  72 static inline int wme_downgrade_ac(struct sk_buff *skb)
  73 {
  74         switch (skb->priority) {
  75         case 6:
  76         case 7:
  77                 skb->priority = 5; /* VO -> VI */
  78                 return 0;
  79         case 4:
  80         case 5:
  81                 skb->priority = 3; /* VI -> BE */
  82                 return 0;
  83         case 0:
  84         case 3:
  85                 skb->priority = 2; /* BE -> BK */
  86                 return 0;
  87         default:
  88                 return -1;
  89         }
  90 }
  91
  92
  93 /* positive return value indicates which queue to use
  94  * negative return value indicates to drop the frame */
  95 static inline int classify80211(struct sk_buff *skb, struct Qdisc *qd)
  96 {
  97         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
  98         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
  99         unsigned short fc = le16_to_cpu(hdr->frame_control);
 100         int qos;
 101         const int ieee802_1d_to_ac[8] = { 2, 3, 3, 2, 1, 1, 0, 0 };
 102
 103         /* see if frame is data or non data frame */
 104         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)) {
 105                 /* management frames go on AC_VO queue, but are sent
 106                 * without QoS control fields */
 107                 return IEEE80211_TX_QUEUE_DATA0;
 108         }
 109
 110         if (0 /* injected */) {
 111                 /* use AC from radiotap */
 112         }
 113
 114         /* is this a QoS frame? */
 115         qos = fc & IEEE80211_STYPE_QOS_DATA;
 116
 117         if (!qos) {
 118                 skb->priority = 0; /* required for correct WPA/11i MIC */
 119                 return ieee802_1d_to_ac[skb->priority];
 120         }
 121
 122         /* use the data classifier to determine what 802.1d tag the
 123          * data frame has */
 124         skb->priority = classify_1d(skb, qd);
 125
 126         /* in case we are a client verify acm is not set for this ac */
 127         while (unlikely(local->wmm_acm & BIT(skb->priority))) {
 128                 if (wme_downgrade_ac(skb)) {
 129                         /* No AC with lower priority has acm=0, drop packet. */
 130                         return -1;
 131                 }
 132         }
 133
 134         /* look up which queue to use for frames with this 1d tag */
 135         return ieee802_1d_to_ac[skb->priority];
 136 }
 137
 138
 139 static int wme_qdiscop_enqueue(struct sk_buff *skb, struct Qdisc* qd)
 140 {
 141         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 142         struct ieee80211_sched_data *q = qdisc_priv(qd);
 143         struct ieee80211_tx_packet_data *pkt_data =
 144                 (struct ieee80211_tx_packet_data *) skb->cb;
 145         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 146         unsigned short fc = le16_to_cpu(hdr->frame_control);
 147         struct Qdisc *qdisc;
 148         int err, queue;
 149
 150         if (pkt_data->flags & IEEE80211_TXPD_REQUEUE) {
 151                 skb_queue_tail(&q->requeued[pkt_data->queue], skb);
 152                 qd->q.qlen++;
 153                 return 0;
 154         }
 155
 156         queue = classify80211(skb, qd);
 157
 158         /* now we know the 1d priority, fill in the QoS header if there is one
 159          */
 160         if (WLAN_FC_IS_QOS_DATA(fc)) {
 161                 u8 *p = skb->data + ieee80211_get_hdrlen(fc) - 2;
 162                 u8 qos_hdr = skb->priority & QOS_CONTROL_TAG1D_MASK;
 163                 if (local->wifi_wme_noack_test)
 164                         qos_hdr |= QOS_CONTROL_ACK_POLICY_NOACK <<
 165                                         QOS_CONTROL_ACK_POLICY_SHIFT;
 166                 /* qos header is 2 bytes, second reserved */
 167                 *p = qos_hdr;
 168                 p++;
 169                 *p = 0;
 170         }
 171
 172         if (unlikely(queue >= local->hw.queues)) {
 173 #if 0
 174                 if (net_ratelimit()) {
 175                         printk(KERN_DEBUG "%s - queue=%d (hw does not "
 176                                "support) -> %d\n",
 177                                __func__, queue, local->hw.queues - 1);
 178                 }
 179 #endif
 180                 queue = local->hw.queues - 1;
 181         }
 182
 183         if (unlikely(queue < 0)) {
 184                         kfree_skb(skb);
 185                         err = NET_XMIT_DROP;
 186         } else {
 187                 pkt_data->queue = (unsigned int) queue;
 188                 qdisc = q->queues[queue];
 189                 err = qdisc->enqueue(skb, qdisc);
 190                 if (err == NET_XMIT_SUCCESS) {
 191                         qd->q.qlen++;
 192                         qd->bstats.bytes += skb->len;
 193                         qd->bstats.packets++;
 194                         return NET_XMIT_SUCCESS;
 195                 }
 196         }
 197         qd->qstats.drops++;
 198         return err;
 199 }
 200
 201
 202 /* TODO: clean up the cases where master_hard_start_xmit
 203  * returns non 0 - it shouldn't ever do that. Once done we
 204  * can remove this function */
 205 static int wme_qdiscop_requeue(struct sk_buff *skb, struct Qdisc* qd)
 206 {
 207         struct ieee80211_sched_data *q = qdisc_priv(qd);
 208         struct ieee80211_tx_packet_data *pkt_data =
 209                 (struct ieee80211_tx_packet_data *) skb->cb;
 210         struct Qdisc *qdisc;
 211         int err;
 212
 213         /* we recorded which queue to use earlier! */
 214         qdisc = q->queues[pkt_data->queue];
 215
 216         if ((err = qdisc->ops->requeue(skb, qdisc)) == 0) {
 217                 qd->q.qlen++;
 218                 return 0;
 219         }
 220         qd->qstats.drops++;
 221         return err;
 222 }
 223
 224
 225 static struct sk_buff *wme_qdiscop_dequeue(struct Qdisc* qd)
 226 {
 227         struct ieee80211_sched_data *q = qdisc_priv(qd);
 228         struct net_device *dev = qd->dev;
 229         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 230         struct ieee80211_hw *hw = &local->hw;
 231         struct sk_buff *skb;
 232         struct Qdisc *qdisc;
 233         int queue;
 234
 235         /* check all the h/w queues in numeric/priority order */
 236         for (queue = 0; queue < hw->queues; queue++) {
 237                 /* see if there is room in this hardware queue */
 238                 if (test_bit(IEEE80211_LINK_STATE_XOFF,
 239                              &local->state[queue]) ||
 240                     test_bit(IEEE80211_LINK_STATE_PENDING,
 241                              &local->state[queue]))
 242                         continue;
 243
 244                 /* there is space - try and get a frame */
 245                 skb = skb_dequeue(&q->requeued[queue]);
 246                 if (skb) {
 247                         qd->q.qlen--;
 248                         return skb;
 249                 }
 250
 251                 qdisc = q->queues[queue];
 252                 skb = qdisc->dequeue(qdisc);
 253                 if (skb) {
 254                         qd->q.qlen--;
 255                         return skb;
 256                 }
 257         }
 258         /* returning a NULL here when all the h/w queues are full means we
 259          * never need to call netif_stop_queue in the driver */
 260         return NULL;
 261 }
 262
 263
 264 static void wme_qdiscop_reset(struct Qdisc* qd)
 265 {
 266         struct ieee80211_sched_data *q = qdisc_priv(qd);
 267         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 268         struct ieee80211_hw *hw = &local->hw;
 269         int queue;
 270
 271         /* QUESTION: should we have some hardware flush functionality here? */
 272
 273         for (queue = 0; queue < hw->queues; queue++) {
 274                 skb_queue_purge(&q->requeued[queue]);
 275                 qdisc_reset(q->queues[queue]);
 276         }
 277         qd->q.qlen = 0;
 278 }
 279
 280
 281 static void wme_qdiscop_destroy(struct Qdisc* qd)
 282 {
 283         struct ieee80211_sched_data *q = qdisc_priv(qd);
 284         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 285         struct ieee80211_hw *hw = &local->hw;
 286         int queue;
 287
 288         tcf_destroy_chain(q->filter_list);
 289         q->filter_list = NULL;
 290
 291         for (queue=0; queue < hw->queues; queue++) {
 292                 skb_queue_purge(&q->requeued[queue]);
 293                 qdisc_destroy(q->queues[queue]);
 294                 q->queues[queue] = &noop_qdisc;
 295         }
 296 }
 297
 298
 299 /* called whenever parameters are updated on existing qdisc */
 300 static int wme_qdiscop_tune(struct Qdisc *qd, struct nlattr *opt)
 301 {
 302 /*      struct ieee80211_sched_data *q = qdisc_priv(qd);
 303 */
 304         /* check our options block is the right size */
 305         /* copy any options to our local structure */
 306 /*      Ignore options block for now - always use static mapping
 307         struct tc_ieee80211_qopt *qopt = nla_data(opt);
 308
 309         if (opt->nla_len < nla_attr_size(sizeof(*qopt)))
 310                 return -EINVAL;
 311         memcpy(q->tag2queue, qopt->tag2queue, sizeof(qopt->tag2queue));
 312 */
 313         return 0;
 314 }
 315
 316
 317 /* called during initial creation of qdisc on device */
 318 static int wme_qdiscop_init(struct Qdisc *qd, struct nlattr *opt)
 319 {
 320         struct ieee80211_sched_data *q = qdisc_priv(qd);
 321         struct net_device *dev = qd->dev;
 322         struct ieee80211_local *local;
 323         int queues;
 324         int err = 0, i;
 325
 326         /* check that device is a mac80211 device */
 327         if (!dev->ieee80211_ptr ||
 328             dev->ieee80211_ptr->wiphy->privid != mac80211_wiphy_privid)
 329                 return -EINVAL;
 330
 331         /* check this device is an ieee80211 master type device */
 332         if (dev->type != ARPHRD_IEEE80211)
 333                 return -EINVAL;
 334
 335         /* check that there is no qdisc currently attached to device
 336          * this ensures that we will be the root qdisc. (I can't find a better
 337          * way to test this explicitly) */
 338         if (dev->qdisc_sleeping != &noop_qdisc)
 339                 return -EINVAL;
 340
 341         if (qd->flags & TCQ_F_INGRESS)
 342                 return -EINVAL;
 343
 344         local = wdev_priv(dev->ieee80211_ptr);
 345         queues = local->hw.queues;
 346
 347         /* if options were passed in, set them */
 348         if (opt) {
 349                 err = wme_qdiscop_tune(qd, opt);
 350         }
 351
 352         /* create child queues */
 353         for (i = 0; i < queues; i++) {
 354                 skb_queue_head_init(&q->requeued[i]);
 355                 q->queues[i] = qdisc_create_dflt(qd->dev, &pfifo_qdisc_ops,
 356                                                  qd->handle);
 357                 if (!q->queues[i]) {
 358                         q->queues[i] = &noop_qdisc;
 359                         printk(KERN_ERR "%s child qdisc %i creation failed", dev->name, i);
 360                 }
 361         }
 362
 363         return err;
 364 }
 365
 366 static int wme_qdiscop_dump(struct Qdisc *qd, struct sk_buff *skb)
 367 {
 368 /*      struct ieee80211_sched_data *q = qdisc_priv(qd);
 369         unsigned char *p = skb->tail;
 370         struct tc_ieee80211_qopt opt;
 371
 372         memcpy(&opt.tag2queue, q->tag2queue, TC_80211_MAX_TAG + 1);
 373         NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
 374 */      return skb->len;
 375 /*
 376 nla_put_failure:
 377         skb_trim(skb, p - skb->data);*/
 378         return -1;
 379 }
 380
 381
 382 static int wme_classop_graft(struct Qdisc *qd, unsigned long arg,
 383                              struct Qdisc *new, struct Qdisc **old)
 384 {
 385         struct ieee80211_sched_data *q = qdisc_priv(qd);
 386         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 387         struct ieee80211_hw *hw = &local->hw;
 388         unsigned long queue = arg - 1;
 389
 390         if (queue >= hw->queues)
 391                 return -EINVAL;
 392
 393         if (!new)
 394                 new = &noop_qdisc;
 395
 396         sch_tree_lock(qd);
 397         *old = q->queues[queue];
 398         q->queues[queue] = new;
 399         qdisc_reset(*old);
 400         sch_tree_unlock(qd);
 401
 402         return 0;
 403 }
 404
 405
 406 static struct Qdisc *
 407 wme_classop_leaf(struct Qdisc *qd, unsigned long arg)
 408 {
 409         struct ieee80211_sched_data *q = qdisc_priv(qd);
 410         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 411         struct ieee80211_hw *hw = &local->hw;
 412         unsigned long queue = arg - 1;
 413
 414         if (queue >= hw->queues)
 415                 return NULL;
 416
 417         return q->queues[queue];
 418 }
 419
 420
 421 static unsigned long wme_classop_get(struct Qdisc *qd, u32 classid)
 422 {
 423         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 424         struct ieee80211_hw *hw = &local->hw;
 425         unsigned long queue = TC_H_MIN(classid);
 426
 427         if (queue - 1 >= hw->queues)
 428                 return 0;
 429
 430         return queue;
 431 }
 432
 433
 434 static unsigned long wme_classop_bind(struct Qdisc *qd, unsigned long parent,
 435                                       u32 classid)
 436 {
 437         return wme_classop_get(qd, classid);
 438 }
 439
 440
 441 static void wme_classop_put(struct Qdisc *q, unsigned long cl)
 442 {
 443 }
 444
 445
 446 static int wme_classop_change(struct Qdisc *qd, u32 handle, u32 parent,
 447                               struct nlattr **tca, unsigned long *arg)
 448 {
 449         unsigned long cl = *arg;
 450         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 451         struct ieee80211_hw *hw = &local->hw;
 452
 453         if (cl - 1 > hw->queues)
 454                 return -ENOENT;
 455
 456         /* TODO: put code to program hardware queue parameters here,
 457          * to allow programming from tc command line */
 458
 459         return 0;
 460 }
 461
 462
 463 /* we don't support deleting hardware queues
 464  * when we add WMM-SA support - TSPECs may be deleted here */
 465 static int wme_classop_delete(struct Qdisc *qd, unsigned long cl)
 466 {
 467         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 468         struct ieee80211_hw *hw = &local->hw;
 469
 470         if (cl - 1 > hw->queues)
 471                 return -ENOENT;
 472         return 0;
 473 }
 474
 475
 476 static int wme_classop_dump_class(struct Qdisc *qd, unsigned long cl,
 477                                   struct sk_buff *skb, struct tcmsg *tcm)
 478 {
 479         struct ieee80211_sched_data *q = qdisc_priv(qd);
 480         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 481         struct ieee80211_hw *hw = &local->hw;
 482
 483         if (cl - 1 > hw->queues)
 484                 return -ENOENT;
 485         tcm->tcm_handle = TC_H_MIN(cl);
 486         tcm->tcm_parent = qd->handle;
 487         tcm->tcm_info = q->queues[cl-1]->handle; /* do we need this? */
 488         return 0;
 489 }
 490
 491
 492 static void wme_classop_walk(struct Qdisc *qd, struct qdisc_walker *arg)
 493 {
 494         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 495         struct ieee80211_hw *hw = &local->hw;
 496         int queue;
 497
 498         if (arg->stop)
 499                 return;
 500
 501         for (queue = 0; queue < hw->queues; queue++) {
 502                 if (arg->count < arg->skip) {
 503                         arg->count++;
 504                         continue;
 505                 }
 506                 /* we should return classids for our internal queues here
 507                  * as well as the external ones */
 508                 if (arg->fn(qd, queue+1, arg) < 0) {
 509                         arg->stop = 1;
 510                         break;
 511                 }
 512                 arg->count++;
 513         }
 514 }
 515
 516
 517 static struct tcf_proto ** wme_classop_find_tcf(struct Qdisc *qd,
 518                                                 unsigned long cl)
 519 {
 520         struct ieee80211_sched_data *q = qdisc_priv(qd);
 521
 522         if (cl)
 523                 return NULL;
 524
 525         return &q->filter_list;
 526 }
 527
 528
 529 /* this qdisc is classful (i.e. has classes, some of which may have leaf qdiscs attached)
 530  * - these are the operations on the classes */
 531 static const struct Qdisc_class_ops class_ops =
 532 {
 533         .graft = wme_classop_graft,
 534         .leaf = wme_classop_leaf,
 535
 536         .get = wme_classop_get,
 537         .put = wme_classop_put,
 538         .change = wme_classop_change,
 539         .delete = wme_classop_delete,
 540         .walk = wme_classop_walk,
 541
 542         .tcf_chain = wme_classop_find_tcf,
 543         .bind_tcf = wme_classop_bind,
 544         .unbind_tcf = wme_classop_put,
 545
 546         .dump = wme_classop_dump_class,
 547 };
 548
 549
 550 /* queueing discipline operations */
 551 static struct Qdisc_ops wme_qdisc_ops __read_mostly =
 552 {
 553         .next = NULL,
 554         .cl_ops = &class_ops,
 555         .id = "ieee80211",
 556         .priv_size = sizeof(struct ieee80211_sched_data),
 557
 558         .enqueue = wme_qdiscop_enqueue,
 559         .dequeue = wme_qdiscop_dequeue,
 560         .requeue = wme_qdiscop_requeue,
 561         .drop = NULL, /* drop not needed since we are always the root qdisc */
 562
 563         .init = wme_qdiscop_init,
 564         .reset = wme_qdiscop_reset,
 565         .destroy = wme_qdiscop_destroy,
 566         .change = wme_qdiscop_tune,
 567
 568         .dump = wme_qdiscop_dump,
 569 };
 570
 571
 572 void ieee80211_install_qdisc(struct net_device *dev)
 573 {
 574         struct Qdisc *qdisc;
 575
 576         qdisc = qdisc_create_dflt(dev, &wme_qdisc_ops, TC_H_ROOT);
 577         if (!qdisc) {
 578                 printk(KERN_ERR "%s: qdisc installation failed\n", dev->name);
 579                 return;
 580         }
 581
 582         /* same handle as would be allocated by qdisc_alloc_handle() */
 583         qdisc->handle = 0x80010000;
 584
 585         qdisc_lock_tree(dev);
 586         list_add_tail(&qdisc->list, &dev->qdisc_list);
 587         dev->qdisc_sleeping = qdisc;
 588         qdisc_unlock_tree(dev);
 589 }
 590
 591
 592 int ieee80211_qdisc_installed(struct net_device *dev)
 593 {
 594         return dev->qdisc_sleeping->ops == &wme_qdisc_ops;
 595 }
 596
 597
 598 int ieee80211_wme_register(void)
 599 {
 600         return register_qdisc(&wme_qdisc_ops);
 601 }
 602
 603
 604 void ieee80211_wme_unregister(void)
 605 {
 606         unregister_qdisc(&wme_qdisc_ops);
 607 }