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