include/net/sch_generic.h

   1 #ifndef __NET_SCHED_GENERIC_H
   2 #define __NET_SCHED_GENERIC_H
   3
   4 #include <linux/netdevice.h>
   5 #include <linux/types.h>
   6 #include <linux/rcupdate.h>
   7 #include <linux/module.h>
   8 #include <linux/pkt_sched.h>
   9 #include <linux/pkt_cls.h>
  10 #include <net/gen_stats.h>
  11 #include <net/rtnetlink.h>
  12
  13 struct Qdisc_ops;
  14 struct qdisc_walker;
  15 struct tcf_walker;
  16 struct module;
  17
  18 struct qdisc_rate_table {
  19         struct tc_ratespec rate;
  20         u32             data[256];
  21         struct qdisc_rate_table *next;
  22         int             refcnt;
  23 };
  24
  25 enum qdisc_state_t {
  26         __QDISC_STATE_SCHED,
  27         __QDISC_STATE_DEACTIVATED,
  28 };
  29
  30 /*
  31  * following bits are only changed while qdisc lock is held
  32  */
  33 enum qdisc___state_t {
  34         __QDISC___STATE_RUNNING,
  35 };
  36
  37 struct qdisc_size_table {
  38         struct list_head        list;
  39         struct tc_sizespec      szopts;
  40         int                     refcnt;
  41         u16                     data[];
  42 };
  43
  44 struct Qdisc {
  45         int                     (*enqueue)(struct sk_buff *skb, struct Qdisc *dev);
  46         struct sk_buff *        (*dequeue)(struct Qdisc *dev);
  47         unsigned                flags;
  48 #define TCQ_F_BUILTIN           1
  49 #define TCQ_F_THROTTLED         2
  50 #define TCQ_F_INGRESS           4
  51 #define TCQ_F_CAN_BYPASS        8
  52 #define TCQ_F_MQROOT            16
  53 #define TCQ_F_WARN_NONWC        (1 << 16)
  54         int                     padded;
  55         struct Qdisc_ops        *ops;
  56         struct qdisc_size_table *stab;
  57         struct list_head        list;
  58         u32                     handle;
  59         u32                     parent;
  60         atomic_t                refcnt;
  61         struct gnet_stats_rate_est      rate_est;
  62         int                     (*reshape_fail)(struct sk_buff *skb,
  63                                         struct Qdisc *q);
  64
  65         void                    *u32_node;
  66
  67         /* This field is deprecated, but it is still used by CBQ
  68          * and it will live until better solution will be invented.
  69          */
  70         struct Qdisc            *__parent;
  71         struct netdev_queue     *dev_queue;
  72         struct Qdisc            *next_sched;
  73
  74         struct sk_buff          *gso_skb;
  75         /*
  76          * For performance sake on SMP, we put highly modified fields at the end
  77          */
  78         unsigned long           state;
  79         struct sk_buff_head     q;
  80         struct gnet_stats_basic_packed bstats;
  81         unsigned long           __state;
  82         struct gnet_stats_queue qstats;
  83         struct rcu_head         rcu_head;
  84         spinlock_t              busylock;
  85 };
  86
  87 static inline bool qdisc_is_running(struct Qdisc *qdisc)
  88 {
  89         return test_bit(__QDISC___STATE_RUNNING, &qdisc->__state);
  90 }
  91
  92 static inline bool qdisc_run_begin(struct Qdisc *qdisc)
  93 {
  94         return !__test_and_set_bit(__QDISC___STATE_RUNNING, &qdisc->__state);
  95 }
  96
  97 static inline void qdisc_run_end(struct Qdisc *qdisc)
  98 {
  99         __clear_bit(__QDISC___STATE_RUNNING, &qdisc->__state);
 100 }
 101
 102 struct Qdisc_class_ops {
 103         /* Child qdisc manipulation */
 104         struct netdev_queue *   (*select_queue)(struct Qdisc *, struct tcmsg *);
 105         int                     (*graft)(struct Qdisc *, unsigned long cl,
 106                                         struct Qdisc *, struct Qdisc **);
 107         struct Qdisc *          (*leaf)(struct Qdisc *, unsigned long cl);
 108         void                    (*qlen_notify)(struct Qdisc *, unsigned long);
 109
 110         /* Class manipulation routines */
 111         unsigned long           (*get)(struct Qdisc *, u32 classid);
 112         void                    (*put)(struct Qdisc *, unsigned long);
 113         int                     (*change)(struct Qdisc *, u32, u32,
 114                                         struct nlattr **, unsigned long *);
 115         int                     (*delete)(struct Qdisc *, unsigned long);
 116         void                    (*walk)(struct Qdisc *, struct qdisc_walker * arg);
 117
 118         /* Filter manipulation */
 119         struct tcf_proto **     (*tcf_chain)(struct Qdisc *, unsigned long);
 120         unsigned long           (*bind_tcf)(struct Qdisc *, unsigned long,
 121                                         u32 classid);
 122         void                    (*unbind_tcf)(struct Qdisc *, unsigned long);
 123
 124         /* rtnetlink specific */
 125         int                     (*dump)(struct Qdisc *, unsigned long,
 126                                         struct sk_buff *skb, struct tcmsg*);
 127         int                     (*dump_stats)(struct Qdisc *, unsigned long,
 128                                         struct gnet_dump *);
 129 };
 130
 131 struct Qdisc_ops {
 132         struct Qdisc_ops        *next;
 133         const struct Qdisc_class_ops    *cl_ops;
 134         char                    id[IFNAMSIZ];
 135         int                     priv_size;
 136
 137         int                     (*enqueue)(struct sk_buff *, struct Qdisc *);
 138         struct sk_buff *        (*dequeue)(struct Qdisc *);
 139         struct sk_buff *        (*peek)(struct Qdisc *);
 140         unsigned int            (*drop)(struct Qdisc *);
 141
 142         int                     (*init)(struct Qdisc *, struct nlattr *arg);
 143         void                    (*reset)(struct Qdisc *);
 144         void                    (*destroy)(struct Qdisc *);
 145         int                     (*change)(struct Qdisc *, struct nlattr *arg);
 146         void                    (*attach)(struct Qdisc *);
 147
 148         int                     (*dump)(struct Qdisc *, struct sk_buff *);
 149         int                     (*dump_stats)(struct Qdisc *, struct gnet_dump *);
 150
 151         struct module           *owner;
 152 };
 153
 154
 155 struct tcf_result {
 156         unsigned long   class;
 157         u32             classid;
 158 };
 159
 160 struct tcf_proto_ops {
 161         struct tcf_proto_ops    *next;
 162         char                    kind[IFNAMSIZ];
 163
 164         int                     (*classify)(struct sk_buff*, struct tcf_proto*,
 165                                         struct tcf_result *);
 166         int                     (*init)(struct tcf_proto*);
 167         void                    (*destroy)(struct tcf_proto*);
 168
 169         unsigned long           (*get)(struct tcf_proto*, u32 handle);
 170         void                    (*put)(struct tcf_proto*, unsigned long);
 171         int                     (*change)(struct tcf_proto*, unsigned long,
 172                                         u32 handle, struct nlattr **,
 173                                         unsigned long *);
 174         int                     (*delete)(struct tcf_proto*, unsigned long);
 175         void                    (*walk)(struct tcf_proto*, struct tcf_walker *arg);
 176
 177         /* rtnetlink specific */
 178         int                     (*dump)(struct tcf_proto*, unsigned long,
 179                                         struct sk_buff *skb, struct tcmsg*);
 180
 181         struct module           *owner;
 182 };
 183
 184 struct tcf_proto {
 185         /* Fast access part */
 186         struct tcf_proto        *next;
 187         void                    *root;
 188         int                     (*classify)(struct sk_buff*, struct tcf_proto*,
 189                                         struct tcf_result *);
 190         __be16                  protocol;
 191
 192         /* All the rest */
 193         u32                     prio;
 194         u32                     classid;
 195         struct Qdisc            *q;
 196         void                    *data;
 197         struct tcf_proto_ops    *ops;
 198 };
 199
 200 struct qdisc_skb_cb {
 201         unsigned int            pkt_len;
 202         char                    data[];
 203 };
 204
 205 static inline int qdisc_qlen(struct Qdisc *q)
 206 {
 207         return q->q.qlen;
 208 }
 209
 210 static inline struct qdisc_skb_cb *qdisc_skb_cb(struct sk_buff *skb)
 211 {
 212         return (struct qdisc_skb_cb *)skb->cb;
 213 }
 214
 215 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
 216 {
 217         return &qdisc->q.lock;
 218 }
 219
 220 static inline struct Qdisc *qdisc_root(struct Qdisc *qdisc)
 221 {
 222         return qdisc->dev_queue->qdisc;
 223 }
 224
 225 static inline struct Qdisc *qdisc_root_sleeping(struct Qdisc *qdisc)
 226 {
 227         return qdisc->dev_queue->qdisc_sleeping;
 228 }
 229
 230 /* The qdisc root lock is a mechanism by which to top level
 231  * of a qdisc tree can be locked from any qdisc node in the
 232  * forest.  This allows changing the configuration of some
 233  * aspect of the qdisc tree while blocking out asynchronous
 234  * qdisc access in the packet processing paths.
 235  *
 236  * It is only legal to do this when the root will not change
 237  * on us.  Otherwise we'll potentially lock the wrong qdisc
 238  * root.  This is enforced by holding the RTNL semaphore, which
 239  * all users of this lock accessor must do.
 240  */
 241 static inline spinlock_t *qdisc_root_lock(struct Qdisc *qdisc)
 242 {
 243         struct Qdisc *root = qdisc_root(qdisc);
 244
 245         ASSERT_RTNL();
 246         return qdisc_lock(root);
 247 }
 248
 249 static inline spinlock_t *qdisc_root_sleeping_lock(struct Qdisc *qdisc)
 250 {
 251         struct Qdisc *root = qdisc_root_sleeping(qdisc);
 252
 253         ASSERT_RTNL();
 254         return qdisc_lock(root);
 255 }
 256
 257 static inline struct net_device *qdisc_dev(struct Qdisc *qdisc)
 258 {
 259         return qdisc->dev_queue->dev;
 260 }
 261
 262 static inline void sch_tree_lock(struct Qdisc *q)
 263 {
 264         spin_lock_bh(qdisc_root_sleeping_lock(q));
 265 }
 266
 267 static inline void sch_tree_unlock(struct Qdisc *q)
 268 {
 269         spin_unlock_bh(qdisc_root_sleeping_lock(q));
 270 }
 271
 272 #define tcf_tree_lock(tp)       sch_tree_lock((tp)->q)
 273 #define tcf_tree_unlock(tp)     sch_tree_unlock((tp)->q)
 274
 275 extern struct Qdisc noop_qdisc;
 276 extern struct Qdisc_ops noop_qdisc_ops;
 277 extern struct Qdisc_ops pfifo_fast_ops;
 278 extern struct Qdisc_ops mq_qdisc_ops;
 279
 280 struct Qdisc_class_common {
 281         u32                     classid;
 282         struct hlist_node       hnode;
 283 };
 284
 285 struct Qdisc_class_hash {
 286         struct hlist_head       *hash;
 287         unsigned int            hashsize;
 288         unsigned int            hashmask;
 289         unsigned int            hashelems;
 290 };
 291
 292 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
 293 {
 294         id ^= id >> 8;
 295         id ^= id >> 4;
 296         return id & mask;
 297 }
 298
 299 static inline struct Qdisc_class_common *
 300 qdisc_class_find(struct Qdisc_class_hash *hash, u32 id)
 301 {
 302         struct Qdisc_class_common *cl;
 303         struct hlist_node *n;
 304         unsigned int h;
 305
 306         h = qdisc_class_hash(id, hash->hashmask);
 307         hlist_for_each_entry(cl, n, &hash->hash[h], hnode) {
 308                 if (cl->classid == id)
 309                         return cl;
 310         }
 311         return NULL;
 312 }
 313
 314 extern int qdisc_class_hash_init(struct Qdisc_class_hash *);
 315 extern void qdisc_class_hash_insert(struct Qdisc_class_hash *, struct Qdisc_class_common *);
 316 extern void qdisc_class_hash_remove(struct Qdisc_class_hash *, struct Qdisc_class_common *);
 317 extern void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
 318 extern void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
 319
 320 extern void dev_init_scheduler(struct net_device *dev);
 321 extern void dev_shutdown(struct net_device *dev);
 322 extern void dev_activate(struct net_device *dev);
 323 extern void dev_deactivate(struct net_device *dev);
 324 extern struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
 325                                      struct Qdisc *qdisc);
 326 extern void qdisc_reset(struct Qdisc *qdisc);
 327 extern void qdisc_destroy(struct Qdisc *qdisc);
 328 extern void qdisc_tree_decrease_qlen(struct Qdisc *qdisc, unsigned int n);
 329 extern struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
 330                                  struct Qdisc_ops *ops);
 331 extern struct Qdisc *qdisc_create_dflt(struct net_device *dev,
 332                                        struct netdev_queue *dev_queue,
 333                                        struct Qdisc_ops *ops, u32 parentid);
 334 extern void qdisc_calculate_pkt_len(struct sk_buff *skb,
 335                                    struct qdisc_size_table *stab);
 336 extern void tcf_destroy(struct tcf_proto *tp);
 337 extern void tcf_destroy_chain(struct tcf_proto **fl);
 338
 339 /* Reset all TX qdiscs of a device.  */
 340 static inline void qdisc_reset_all_tx(struct net_device *dev)
 341 {
 342         unsigned int i;
 343         for (i = 0; i < dev->num_tx_queues; i++)
 344                 qdisc_reset(netdev_get_tx_queue(dev, i)->qdisc);
 345 }
 346
 347 /* Are all TX queues of the device empty?  */
 348 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
 349 {
 350         unsigned int i;
 351         for (i = 0; i < dev->num_tx_queues; i++) {
 352                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 353                 const struct Qdisc *q = txq->qdisc;
 354
 355                 if (q->q.qlen)
 356                         return false;
 357         }
 358         return true;
 359 }
 360
 361 /* Are any of the TX qdiscs changing?  */
 362 static inline bool qdisc_tx_changing(struct net_device *dev)
 363 {
 364         unsigned int i;
 365         for (i = 0; i < dev->num_tx_queues; i++) {
 366                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 367                 if (txq->qdisc != txq->qdisc_sleeping)
 368                         return true;
 369         }
 370         return false;
 371 }
 372
 373 /* Is the device using the noop qdisc on all queues?  */
 374 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
 375 {
 376         unsigned int i;
 377         for (i = 0; i < dev->num_tx_queues; i++) {
 378                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 379                 if (txq->qdisc != &noop_qdisc)
 380                         return false;
 381         }
 382         return true;
 383 }
 384
 385 static inline unsigned int qdisc_pkt_len(struct sk_buff *skb)
 386 {
 387         return qdisc_skb_cb(skb)->pkt_len;
 388 }
 389
 390 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
 391 enum net_xmit_qdisc_t {
 392         __NET_XMIT_STOLEN = 0x00010000,
 393         __NET_XMIT_BYPASS = 0x00020000,
 394 };
 395
 396 #ifdef CONFIG_NET_CLS_ACT
 397 #define net_xmit_drop_count(e)  ((e) & __NET_XMIT_STOLEN ? 0 : 1)
 398 #else
 399 #define net_xmit_drop_count(e)  (1)
 400 #endif
 401
 402 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 403 {
 404 #ifdef CONFIG_NET_SCHED
 405         if (sch->stab)
 406                 qdisc_calculate_pkt_len(skb, sch->stab);
 407 #endif
 408         return sch->enqueue(skb, sch);
 409 }
 410
 411 static inline int qdisc_enqueue_root(struct sk_buff *skb, struct Qdisc *sch)
 412 {
 413         qdisc_skb_cb(skb)->pkt_len = skb->len;
 414         return qdisc_enqueue(skb, sch) & NET_XMIT_MASK;
 415 }
 416
 417 static inline void __qdisc_update_bstats(struct Qdisc *sch, unsigned int len)
 418 {
 419         sch->bstats.bytes += len;
 420         sch->bstats.packets++;
 421 }
 422
 423 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
 424                                        struct sk_buff_head *list)
 425 {
 426         __skb_queue_tail(list, skb);
 427         sch->qstats.backlog += qdisc_pkt_len(skb);
 428         __qdisc_update_bstats(sch, qdisc_pkt_len(skb));
 429
 430         return NET_XMIT_SUCCESS;
 431 }
 432
 433 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
 434 {
 435         return __qdisc_enqueue_tail(skb, sch, &sch->q);
 436 }
 437
 438 static inline struct sk_buff *__qdisc_dequeue_head(struct Qdisc *sch,
 439                                                    struct sk_buff_head *list)
 440 {
 441         struct sk_buff *skb = __skb_dequeue(list);
 442
 443         if (likely(skb != NULL))
 444                 sch->qstats.backlog -= qdisc_pkt_len(skb);
 445
 446         return skb;
 447 }
 448
 449 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
 450 {
 451         return __qdisc_dequeue_head(sch, &sch->q);
 452 }
 453
 454 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
 455                                               struct sk_buff_head *list)
 456 {
 457         struct sk_buff *skb = __qdisc_dequeue_head(sch, list);
 458
 459         if (likely(skb != NULL)) {
 460                 unsigned int len = qdisc_pkt_len(skb);
 461                 kfree_skb(skb);
 462                 return len;
 463         }
 464
 465         return 0;
 466 }
 467
 468 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch)
 469 {
 470         return __qdisc_queue_drop_head(sch, &sch->q);
 471 }
 472
 473 static inline struct sk_buff *__qdisc_dequeue_tail(struct Qdisc *sch,
 474                                                    struct sk_buff_head *list)
 475 {
 476         struct sk_buff *skb = __skb_dequeue_tail(list);
 477
 478         if (likely(skb != NULL))
 479                 sch->qstats.backlog -= qdisc_pkt_len(skb);
 480
 481         return skb;
 482 }
 483
 484 static inline struct sk_buff *qdisc_dequeue_tail(struct Qdisc *sch)
 485 {
 486         return __qdisc_dequeue_tail(sch, &sch->q);
 487 }
 488
 489 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
 490 {
 491         return skb_peek(&sch->q);
 492 }
 493
 494 /* generic pseudo peek method for non-work-conserving qdisc */
 495 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
 496 {
 497         /* we can reuse ->gso_skb because peek isn't called for root qdiscs */
 498         if (!sch->gso_skb) {
 499                 sch->gso_skb = sch->dequeue(sch);
 500                 if (sch->gso_skb)
 501                         /* it's still part of the queue */
 502                         sch->q.qlen++;
 503         }
 504
 505         return sch->gso_skb;
 506 }
 507
 508 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
 509 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
 510 {
 511         struct sk_buff *skb = sch->gso_skb;
 512
 513         if (skb) {
 514                 sch->gso_skb = NULL;
 515                 sch->q.qlen--;
 516         } else {
 517                 skb = sch->dequeue(sch);
 518         }
 519
 520         return skb;
 521 }
 522
 523 static inline void __qdisc_reset_queue(struct Qdisc *sch,
 524                                        struct sk_buff_head *list)
 525 {
 526         /*
 527          * We do not know the backlog in bytes of this list, it
 528          * is up to the caller to correct it
 529          */
 530         __skb_queue_purge(list);
 531 }
 532
 533 static inline void qdisc_reset_queue(struct Qdisc *sch)
 534 {
 535         __qdisc_reset_queue(sch, &sch->q);
 536         sch->qstats.backlog = 0;
 537 }
 538
 539 static inline unsigned int __qdisc_queue_drop(struct Qdisc *sch,
 540                                               struct sk_buff_head *list)
 541 {
 542         struct sk_buff *skb = __qdisc_dequeue_tail(sch, list);
 543
 544         if (likely(skb != NULL)) {
 545                 unsigned int len = qdisc_pkt_len(skb);
 546                 kfree_skb(skb);
 547                 return len;
 548         }
 549
 550         return 0;
 551 }
 552
 553 static inline unsigned int qdisc_queue_drop(struct Qdisc *sch)
 554 {
 555         return __qdisc_queue_drop(sch, &sch->q);
 556 }
 557
 558 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
 559 {
 560         kfree_skb(skb);
 561         sch->qstats.drops++;
 562
 563         return NET_XMIT_DROP;
 564 }
 565
 566 static inline int qdisc_reshape_fail(struct sk_buff *skb, struct Qdisc *sch)
 567 {
 568         sch->qstats.drops++;
 569
 570 #ifdef CONFIG_NET_CLS_ACT
 571         if (sch->reshape_fail == NULL || sch->reshape_fail(skb, sch))
 572                 goto drop;
 573
 574         return NET_XMIT_SUCCESS;
 575
 576 drop:
 577 #endif
 578         kfree_skb(skb);
 579         return NET_XMIT_DROP;
 580 }
 581
 582 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
 583    long it will take to send a packet given its size.
 584  */
 585 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
 586 {
 587         int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
 588         if (slot < 0)
 589                 slot = 0;
 590         slot >>= rtab->rate.cell_log;
 591         if (slot > 255)
 592                 return (rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF]);
 593         return rtab->data[slot];
 594 }
 595
 596 #ifdef CONFIG_NET_CLS_ACT
 597 static inline struct sk_buff *skb_act_clone(struct sk_buff *skb, gfp_t gfp_mask,
 598                                             int action)
 599 {
 600         struct sk_buff *n;
 601
 602         if ((action == TC_ACT_STOLEN || action == TC_ACT_QUEUED) &&
 603             !skb_shared(skb))
 604                 n = skb_get(skb);
 605         else
 606                 n = skb_clone(skb, gfp_mask);
 607
 608         if (n) {
 609                 n->tc_verd = SET_TC_VERD(n->tc_verd, 0);
 610                 n->tc_verd = CLR_TC_OK2MUNGE(n->tc_verd);
 611                 n->tc_verd = CLR_TC_MUNGED(n->tc_verd);
 612         }
 613         return n;
 614 }
 615 #endif
 616
 617 #endif