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         /* incase 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,
 135                         * drop packet. */
 136                         return -1;
 137                 }
 138         }
 139
 140         /* look up which queue to use for frames with this 1d tag */
 141         return ieee802_1d_to_ac[skb->priority];
 142 }
 143
 144
 145 static int wme_qdiscop_enqueue(struct sk_buff *skb, struct Qdisc* qd)
 146 {
 147         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 148         struct ieee80211_sched_data *q = qdisc_priv(qd);
 149         struct ieee80211_tx_packet_data *pkt_data =
 150                 (struct ieee80211_tx_packet_data *) skb->cb;
 151         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 152         unsigned short fc = le16_to_cpu(hdr->frame_control);
 153         struct Qdisc *qdisc;
 154         int err, queue;
 155
 156         if (pkt_data->flags & IEEE80211_TXPD_REQUEUE) {
 157                 skb_queue_tail(&q->requeued[pkt_data->queue], skb);
 158                 qd->q.qlen++;
 159                 return 0;
 160         }
 161
 162         queue = classify80211(skb, qd);
 163
 164         /* now we know the 1d priority, fill in the QoS header if there is one
 165          */
 166         if (WLAN_FC_IS_QOS_DATA(fc)) {
 167                 u8 *p = skb->data + ieee80211_get_hdrlen(fc) - 2;
 168                 u8 qos_hdr = skb->priority & QOS_CONTROL_TAG1D_MASK;
 169                 if (local->wifi_wme_noack_test)
 170                         qos_hdr |= QOS_CONTROL_ACK_POLICY_NOACK <<
 171                                         QOS_CONTROL_ACK_POLICY_SHIFT;
 172                 /* qos header is 2 bytes, second reserved */
 173                 *p = qos_hdr;
 174                 p++;
 175                 *p = 0;
 176         }
 177
 178         if (unlikely(queue >= local->hw.queues)) {
 179 #if 0
 180                 if (net_ratelimit()) {
 181                         printk(KERN_DEBUG "%s - queue=%d (hw does not "
 182                                "support) -> %d\n",
 183                                __func__, queue, local->hw.queues - 1);
 184                 }
 185 #endif
 186                 queue = local->hw.queues - 1;
 187         }
 188
 189         if (unlikely(queue < 0)) {
 190                         kfree_skb(skb);
 191                         err = NET_XMIT_DROP;
 192         } else {
 193                 pkt_data->queue = (unsigned int) queue;
 194                 qdisc = q->queues[queue];
 195                 err = qdisc->enqueue(skb, qdisc);
 196                 if (err == NET_XMIT_SUCCESS) {
 197                         qd->q.qlen++;
 198                         qd->bstats.bytes += skb->len;
 199                         qd->bstats.packets++;
 200                         return NET_XMIT_SUCCESS;
 201                 }
 202         }
 203         qd->qstats.drops++;
 204         return err;
 205 }
 206
 207
 208 /* TODO: clean up the cases where master_hard_start_xmit
 209  * returns non 0 - it shouldn't ever do that. Once done we
 210  * can remove this function */
 211 static int wme_qdiscop_requeue(struct sk_buff *skb, struct Qdisc* qd)
 212 {
 213         struct ieee80211_sched_data *q = qdisc_priv(qd);
 214         struct ieee80211_tx_packet_data *pkt_data =
 215                 (struct ieee80211_tx_packet_data *) skb->cb;
 216         struct Qdisc *qdisc;
 217         int err;
 218
 219         /* we recorded which queue to use earlier! */
 220         qdisc = q->queues[pkt_data->queue];
 221
 222         if ((err = qdisc->ops->requeue(skb, qdisc)) == 0) {
 223                 qd->q.qlen++;
 224                 return 0;
 225         }
 226         qd->qstats.drops++;
 227         return err;
 228 }
 229
 230
 231 static struct sk_buff *wme_qdiscop_dequeue(struct Qdisc* qd)
 232 {
 233         struct ieee80211_sched_data *q = qdisc_priv(qd);
 234         struct net_device *dev = qd->dev;
 235         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 236         struct ieee80211_hw *hw = &local->hw;
 237         struct sk_buff *skb;
 238         struct Qdisc *qdisc;
 239         int queue;
 240
 241         /* check all the h/w queues in numeric/priority order */
 242         for (queue = 0; queue < hw->queues; queue++) {
 243                 /* see if there is room in this hardware queue */
 244                 if (test_bit(IEEE80211_LINK_STATE_XOFF,
 245                              &local->state[queue]) ||
 246                     test_bit(IEEE80211_LINK_STATE_PENDING,
 247                              &local->state[queue]))
 248                         continue;
 249
 250                 /* there is space - try and get a frame */
 251                 skb = skb_dequeue(&q->requeued[queue]);
 252                 if (skb) {
 253                         qd->q.qlen--;
 254                         return skb;
 255                 }
 256
 257                 qdisc = q->queues[queue];
 258                 skb = qdisc->dequeue(qdisc);
 259                 if (skb) {
 260                         qd->q.qlen--;
 261                         return skb;
 262                 }
 263         }
 264         /* returning a NULL here when all the h/w queues are full means we
 265          * never need to call netif_stop_queue in the driver */
 266         return NULL;
 267 }
 268
 269
 270 static void wme_qdiscop_reset(struct Qdisc* qd)
 271 {
 272         struct ieee80211_sched_data *q = qdisc_priv(qd);
 273         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 274         struct ieee80211_hw *hw = &local->hw;
 275         int queue;
 276
 277         /* QUESTION: should we have some hardware flush functionality here? */
 278
 279         for (queue = 0; queue < hw->queues; queue++) {
 280                 skb_queue_purge(&q->requeued[queue]);
 281                 qdisc_reset(q->queues[queue]);
 282         }
 283         qd->q.qlen = 0;
 284 }
 285
 286
 287 static void wme_qdiscop_destroy(struct Qdisc* qd)
 288 {
 289         struct ieee80211_sched_data *q = qdisc_priv(qd);
 290         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 291         struct ieee80211_hw *hw = &local->hw;
 292         int queue;
 293
 294         tcf_destroy_chain(q->filter_list);
 295         q->filter_list = NULL;
 296
 297         for (queue=0; queue < hw->queues; queue++) {
 298                 skb_queue_purge(&q->requeued[queue]);
 299                 qdisc_destroy(q->queues[queue]);
 300                 q->queues[queue] = &noop_qdisc;
 301         }
 302 }
 303
 304
 305 /* called whenever parameters are updated on existing qdisc */
 306 static int wme_qdiscop_tune(struct Qdisc *qd, struct rtattr *opt)
 307 {
 308 /*      struct ieee80211_sched_data *q = qdisc_priv(qd);
 309 */
 310         /* check our options block is the right size */
 311         /* copy any options to our local structure */
 312 /*      Ignore options block for now - always use static mapping
 313         struct tc_ieee80211_qopt *qopt = RTA_DATA(opt);
 314
 315         if (opt->rta_len < RTA_LENGTH(sizeof(*qopt)))
 316                 return -EINVAL;
 317         memcpy(q->tag2queue, qopt->tag2queue, sizeof(qopt->tag2queue));
 318 */
 319         return 0;
 320 }
 321
 322
 323 /* called during initial creation of qdisc on device */
 324 static int wme_qdiscop_init(struct Qdisc *qd, struct rtattr *opt)
 325 {
 326         struct ieee80211_sched_data *q = qdisc_priv(qd);
 327         struct net_device *dev = qd->dev;
 328         struct ieee80211_local *local;
 329         int queues;
 330         int err = 0, i;
 331
 332         /* check that device is a mac80211 device */
 333         if (!dev->ieee80211_ptr ||
 334             dev->ieee80211_ptr->wiphy->privid != mac80211_wiphy_privid)
 335                 return -EINVAL;
 336
 337         /* check this device is an ieee80211 master type device */
 338         if (dev->type != ARPHRD_IEEE80211)
 339                 return -EINVAL;
 340
 341         /* check that there is no qdisc currently attached to device
 342          * this ensures that we will be the root qdisc. (I can't find a better
 343          * way to test this explicitly) */
 344         if (dev->qdisc_sleeping != &noop_qdisc)
 345                 return -EINVAL;
 346
 347         if (qd->flags & TCQ_F_INGRESS)
 348                 return -EINVAL;
 349
 350         local = wdev_priv(dev->ieee80211_ptr);
 351         queues = local->hw.queues;
 352
 353         /* if options were passed in, set them */
 354         if (opt) {
 355                 err = wme_qdiscop_tune(qd, opt);
 356         }
 357
 358         /* create child queues */
 359         for (i = 0; i < queues; i++) {
 360                 skb_queue_head_init(&q->requeued[i]);
 361                 q->queues[i] = qdisc_create_dflt(qd->dev, &pfifo_qdisc_ops,
 362                                                  qd->handle);
 363                 if (!q->queues[i]) {
 364                         q->queues[i] = &noop_qdisc;
 365                         printk(KERN_ERR "%s child qdisc %i creation failed", dev->name, i);
 366                 }
 367         }
 368
 369         return err;
 370 }
 371
 372 static int wme_qdiscop_dump(struct Qdisc *qd, struct sk_buff *skb)
 373 {
 374 /*      struct ieee80211_sched_data *q = qdisc_priv(qd);
 375         unsigned char *p = skb->tail;
 376         struct tc_ieee80211_qopt opt;
 377
 378         memcpy(&opt.tag2queue, q->tag2queue, TC_80211_MAX_TAG + 1);
 379         RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
 380 */      return skb->len;
 381 /*
 382 rtattr_failure:
 383         skb_trim(skb, p - skb->data);*/
 384         return -1;
 385 }
 386
 387
 388 static int wme_classop_graft(struct Qdisc *qd, unsigned long arg,
 389                              struct Qdisc *new, struct Qdisc **old)
 390 {
 391         struct ieee80211_sched_data *q = qdisc_priv(qd);
 392         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 393         struct ieee80211_hw *hw = &local->hw;
 394         unsigned long queue = arg - 1;
 395
 396         if (queue >= hw->queues)
 397                 return -EINVAL;
 398
 399         if (!new)
 400                 new = &noop_qdisc;
 401
 402         sch_tree_lock(qd);
 403         *old = q->queues[queue];
 404         q->queues[queue] = new;
 405         qdisc_reset(*old);
 406         sch_tree_unlock(qd);
 407
 408         return 0;
 409 }
 410
 411
 412 static struct Qdisc *
 413 wme_classop_leaf(struct Qdisc *qd, unsigned long arg)
 414 {
 415         struct ieee80211_sched_data *q = qdisc_priv(qd);
 416         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 417         struct ieee80211_hw *hw = &local->hw;
 418         unsigned long queue = arg - 1;
 419
 420         if (queue >= hw->queues)
 421                 return NULL;
 422
 423         return q->queues[queue];
 424 }
 425
 426
 427 static unsigned long wme_classop_get(struct Qdisc *qd, u32 classid)
 428 {
 429         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 430         struct ieee80211_hw *hw = &local->hw;
 431         unsigned long queue = TC_H_MIN(classid);
 432
 433         if (queue - 1 >= hw->queues)
 434                 return 0;
 435
 436         return queue;
 437 }
 438
 439
 440 static unsigned long wme_classop_bind(struct Qdisc *qd, unsigned long parent,
 441                                       u32 classid)
 442 {
 443         return wme_classop_get(qd, classid);
 444 }
 445
 446
 447 static void wme_classop_put(struct Qdisc *q, unsigned long cl)
 448 {
 449 }
 450
 451
 452 static int wme_classop_change(struct Qdisc *qd, u32 handle, u32 parent,
 453                               struct rtattr **tca, unsigned long *arg)
 454 {
 455         unsigned long cl = *arg;
 456         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 457         struct ieee80211_hw *hw = &local->hw;
 458
 459         if (cl - 1 > hw->queues)
 460                 return -ENOENT;
 461
 462         /* TODO: put code to program hardware queue parameters here,
 463          * to allow programming from tc command line */
 464
 465         return 0;
 466 }
 467
 468
 469 /* we don't support deleting hardware queues
 470  * when we add WMM-SA support - TSPECs may be deleted here */
 471 static int wme_classop_delete(struct Qdisc *qd, unsigned long cl)
 472 {
 473         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 474         struct ieee80211_hw *hw = &local->hw;
 475
 476         if (cl - 1 > hw->queues)
 477                 return -ENOENT;
 478         return 0;
 479 }
 480
 481
 482 static int wme_classop_dump_class(struct Qdisc *qd, unsigned long cl,
 483                                   struct sk_buff *skb, struct tcmsg *tcm)
 484 {
 485         struct ieee80211_sched_data *q = qdisc_priv(qd);
 486         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 487         struct ieee80211_hw *hw = &local->hw;
 488
 489         if (cl - 1 > hw->queues)
 490                 return -ENOENT;
 491         tcm->tcm_handle = TC_H_MIN(cl);
 492         tcm->tcm_parent = qd->handle;
 493         tcm->tcm_info = q->queues[cl-1]->handle; /* do we need this? */
 494         return 0;
 495 }
 496
 497
 498 static void wme_classop_walk(struct Qdisc *qd, struct qdisc_walker *arg)
 499 {
 500         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 501         struct ieee80211_hw *hw = &local->hw;
 502         int queue;
 503
 504         if (arg->stop)
 505                 return;
 506
 507         for (queue = 0; queue < hw->queues; queue++) {
 508                 if (arg->count < arg->skip) {
 509                         arg->count++;
 510                         continue;
 511                 }
 512                 /* we should return classids for our internal queues here
 513                  * as well as the external ones */
 514                 if (arg->fn(qd, queue+1, arg) < 0) {
 515                         arg->stop = 1;
 516                         break;
 517                 }
 518                 arg->count++;
 519         }
 520 }
 521
 522
 523 static struct tcf_proto ** wme_classop_find_tcf(struct Qdisc *qd,
 524                                                 unsigned long cl)
 525 {
 526         struct ieee80211_sched_data *q = qdisc_priv(qd);
 527
 528         if (cl)
 529                 return NULL;
 530
 531         return &q->filter_list;
 532 }
 533
 534
 535 /* this qdisc is classful (i.e. has classes, some of which may have leaf qdiscs attached)
 536  * - these are the operations on the classes */
 537 static struct Qdisc_class_ops class_ops =
 538 {
 539         .graft = wme_classop_graft,
 540         .leaf = wme_classop_leaf,
 541
 542         .get = wme_classop_get,
 543         .put = wme_classop_put,
 544         .change = wme_classop_change,
 545         .delete = wme_classop_delete,
 546         .walk = wme_classop_walk,
 547
 548         .tcf_chain = wme_classop_find_tcf,
 549         .bind_tcf = wme_classop_bind,
 550         .unbind_tcf = wme_classop_put,
 551
 552         .dump = wme_classop_dump_class,
 553 };
 554
 555
 556 /* queueing discipline operations */
 557 static struct Qdisc_ops wme_qdisc_ops =
 558 {
 559         .next = NULL,
 560         .cl_ops = &class_ops,
 561         .id = "ieee80211",
 562         .priv_size = sizeof(struct ieee80211_sched_data),
 563
 564         .enqueue = wme_qdiscop_enqueue,
 565         .dequeue = wme_qdiscop_dequeue,
 566         .requeue = wme_qdiscop_requeue,
 567         .drop = NULL, /* drop not needed since we are always the root qdisc */
 568
 569         .init = wme_qdiscop_init,
 570         .reset = wme_qdiscop_reset,
 571         .destroy = wme_qdiscop_destroy,
 572         .change = wme_qdiscop_tune,
 573
 574         .dump = wme_qdiscop_dump,
 575 };
 576
 577
 578 void ieee80211_install_qdisc(struct net_device *dev)
 579 {
 580         struct Qdisc *qdisc;
 581
 582         qdisc = qdisc_create_dflt(dev, &wme_qdisc_ops, TC_H_ROOT);
 583         if (!qdisc) {
 584                 printk(KERN_ERR "%s: qdisc installation failed\n", dev->name);
 585                 return;
 586         }
 587
 588         /* same handle as would be allocated by qdisc_alloc_handle() */
 589         qdisc->handle = 0x80010000;
 590
 591         qdisc_lock_tree(dev);
 592         list_add_tail(&qdisc->list, &dev->qdisc_list);
 593         dev->qdisc_sleeping = qdisc;
 594         qdisc_unlock_tree(dev);
 595 }
 596
 597
 598 int ieee80211_qdisc_installed(struct net_device *dev)
 599 {
 600         return dev->qdisc_sleeping->ops == &wme_qdisc_ops;
 601 }
 602
 603
 604 int ieee80211_wme_register(void)
 605 {
 606         return register_qdisc(&wme_qdisc_ops);
 607 }
 608
 609
 610 void ieee80211_wme_unregister(void)
 611 {
 612         unregister_qdisc(&wme_qdisc_ops);
 613 }