net/sched/sch_htb.c

   1 /* vim: ts=8 sw=8
   2  * net/sched/sch_htb.c  Hierarchical token bucket, feed tree version
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     Martin Devera, <devik@cdi.cz>
  10  *
  11  * Credits (in time order) for older HTB versions:
  12  *              Stef Coene <stef.coene@docum.org>
  13  *                      HTB support at LARTC mailing list
  14  *              Ondrej Kraus, <krauso@barr.cz>
  15  *                      found missing INIT_QDISC(htb)
  16  *              Vladimir Smelhaus, Aamer Akhter, Bert Hubert
  17  *                      helped a lot to locate nasty class stall bug
  18  *              Andi Kleen, Jamal Hadi, Bert Hubert
  19  *                      code review and helpful comments on shaping
  20  *              Tomasz Wrona, <tw@eter.tym.pl>
  21  *                      created test case so that I was able to fix nasty bug
  22  *              Wilfried Weissmann
  23  *                      spotted bug in dequeue code and helped with fix
  24  *              Jiri Fojtasek
  25  *                      fixed requeue routine
  26  *              and many others. thanks.
  27  *
  28  * $Id: sch_htb.c,v 1.25 2003/12/07 11:08:25 devik Exp devik $
  29  */
  30 #include <linux/config.h>
  31 #include <linux/module.h>
  32 #include <asm/uaccess.h>
  33 #include <asm/system.h>
  34 #include <asm/bitops.h>
  35 #include <linux/types.h>
  36 #include <linux/kernel.h>
  37 #include <linux/sched.h>
  38 #include <linux/string.h>
  39 #include <linux/mm.h>
  40 #include <linux/socket.h>
  41 #include <linux/sockios.h>
  42 #include <linux/in.h>
  43 #include <linux/errno.h>
  44 #include <linux/interrupt.h>
  45 #include <linux/if_ether.h>
  46 #include <linux/inet.h>
  47 #include <linux/netdevice.h>
  48 #include <linux/etherdevice.h>
  49 #include <linux/notifier.h>
  50 #include <net/ip.h>
  51 #include <net/route.h>
  52 #include <linux/skbuff.h>
  53 #include <linux/list.h>
  54 #include <linux/compiler.h>
  55 #include <net/sock.h>
  56 #include <net/pkt_sched.h>
  57 #include <linux/rbtree.h>
  58
  59 /* HTB algorithm.
  60     Author: devik@cdi.cz
  61     ========================================================================
  62     HTB is like TBF with multiple classes. It is also similar to CBQ because
  63     it allows to assign priority to each class in hierarchy.
  64     In fact it is another implementation of Floyd's formal sharing.
  65
  66     Levels:
  67     Each class is assigned level. Leaf has ALWAYS level 0 and root
  68     classes have level TC_HTB_MAXDEPTH-1. Interior nodes has level
  69     one less than their parent.
  70 */
  71
  72 #define HTB_HSIZE 16    /* classid hash size */
  73 #define HTB_EWMAC 2     /* rate average over HTB_EWMAC*HTB_HSIZE sec */
  74 #define HTB_DEBUG 1     /* compile debugging support (activated by tc tool) */
  75 #define HTB_RATECM 1    /* whether to use rate computer */
  76 #define HTB_HYSTERESIS 1/* whether to use mode hysteresis for speedup */
  77 #define HTB_QLOCK(S) spin_lock_bh(&(S)->dev->queue_lock)
  78 #define HTB_QUNLOCK(S) spin_unlock_bh(&(S)->dev->queue_lock)
  79 #define HTB_VER 0x30011 /* major must be matched with number suplied by TC as version */
  80
  81 #if HTB_VER >> 16 != TC_HTB_PROTOVER
  82 #error "Mismatched sch_htb.c and pkt_sch.h"
  83 #endif
  84
  85 /* debugging support; S is subsystem, these are defined:
  86   0 - netlink messages
  87   1 - enqueue
  88   2 - drop & requeue
  89   3 - dequeue main
  90   4 - dequeue one prio DRR part
  91   5 - dequeue class accounting
  92   6 - class overlimit status computation
  93   7 - hint tree
  94   8 - event queue
  95  10 - rate estimator
  96  11 - classifier
  97  12 - fast dequeue cache
  98
  99  L is level; 0 = none, 1 = basic info, 2 = detailed, 3 = full
 100  q->debug uint32 contains 16 2-bit fields one for subsystem starting
 101  from LSB
 102  */
 103 #ifdef HTB_DEBUG
 104 #define HTB_DBG_COND(S,L) (((q->debug>>(2*S))&3) >= L)
 105 #define HTB_DBG(S,L,FMT,ARG...) if (HTB_DBG_COND(S,L)) \
 106         printk(KERN_DEBUG FMT,##ARG)
 107 #define HTB_CHCL(cl) BUG_TRAP((cl)->magic == HTB_CMAGIC)
 108 #define HTB_PASSQ q,
 109 #define HTB_ARGQ struct htb_sched *q,
 110 #define static
 111 #undef __inline__
 112 #define __inline__
 113 #undef inline
 114 #define inline
 115 #define HTB_CMAGIC 0xFEFAFEF1
 116 #define htb_safe_rb_erase(N,R) do { BUG_TRAP((N)->rb_color != -1); \
 117                 if ((N)->rb_color == -1) break; \
 118                 rb_erase(N,R); \
 119                 (N)->rb_color = -1; } while (0)
 120 #else
 121 #define HTB_DBG_COND(S,L) (0)
 122 #define HTB_DBG(S,L,FMT,ARG...)
 123 #define HTB_PASSQ
 124 #define HTB_ARGQ
 125 #define HTB_CHCL(cl)
 126 #define htb_safe_rb_erase(N,R) rb_erase(N,R)
 127 #endif
 128
 129
 130 /* used internaly to keep status of single class */
 131 enum htb_cmode {
 132     HTB_CANT_SEND,              /* class can't send and can't borrow */
 133     HTB_MAY_BORROW,             /* class can't send but may borrow */
 134     HTB_CAN_SEND                /* class can send */
 135 };
 136
 137 /* interior & leaf nodes; props specific to leaves are marked L: */
 138 struct htb_class
 139 {
 140 #ifdef HTB_DEBUG
 141         unsigned magic;
 142 #endif
 143     /* general class parameters */
 144     u32 classid;
 145     struct tc_stats     stats;  /* generic stats */
 146     spinlock_t          *stats_lock;
 147     struct tc_htb_xstats xstats;/* our special stats */
 148     int refcnt;                 /* usage count of this class */
 149
 150 #ifdef HTB_RATECM
 151     /* rate measurement counters */
 152     unsigned long rate_bytes,sum_bytes;
 153     unsigned long rate_packets,sum_packets;
 154 #endif
 155
 156     /* topology */
 157     int level;                  /* our level (see above) */
 158     struct htb_class *parent;   /* parent class */
 159     struct list_head hlist;     /* classid hash list item */
 160     struct list_head sibling;   /* sibling list item */
 161     struct list_head children;  /* children list */
 162
 163     union {
 164             struct htb_class_leaf {
 165                     struct Qdisc *q;
 166                     int prio;
 167                     int aprio;
 168                     int quantum;
 169                     int deficit[TC_HTB_MAXDEPTH];
 170                     struct list_head drop_list;
 171             } leaf;
 172             struct htb_class_inner {
 173                     struct rb_root feed[TC_HTB_NUMPRIO]; /* feed trees */
 174                     struct rb_node *ptr[TC_HTB_NUMPRIO]; /* current class ptr */
 175             /* When class changes from state 1->2 and disconnects from
 176                parent's feed then we lost ptr value and start from the
 177               first child again. Here we store classid of the
 178               last valid ptr (used when ptr is NULL). */
 179               u32 last_ptr_id[TC_HTB_NUMPRIO];
 180             } inner;
 181     } un;
 182     struct rb_node node[TC_HTB_NUMPRIO]; /* node for self or feed tree */
 183     struct rb_node pq_node;              /* node for event queue */
 184     unsigned long pq_key;       /* the same type as jiffies global */
 185
 186     int prio_activity;          /* for which prios are we active */
 187     enum htb_cmode cmode;       /* current mode of the class */
 188
 189     /* class attached filters */
 190     struct tcf_proto *filter_list;
 191     int filter_cnt;
 192
 193     int warned;         /* only one warning about non work conserving .. */
 194
 195     /* token bucket parameters */
 196     struct qdisc_rate_table *rate;      /* rate table of the class itself */
 197     struct qdisc_rate_table *ceil;      /* ceiling rate (limits borrows too) */
 198     long buffer,cbuffer;                /* token bucket depth/rate */
 199     long mbuffer;                       /* max wait time */
 200     long tokens,ctokens;                /* current number of tokens */
 201     psched_time_t t_c;                  /* checkpoint time */
 202 };
 203
 204 /* TODO: maybe compute rate when size is too large .. or drop ? */
 205 static __inline__ long L2T(struct htb_class *cl,struct qdisc_rate_table *rate,
 206         int size)
 207 {
 208     int slot = size >> rate->rate.cell_log;
 209     if (slot > 255) {
 210         cl->xstats.giants++;
 211         slot = 255;
 212     }
 213     return rate->data[slot];
 214 }
 215
 216 struct htb_sched
 217 {
 218     struct list_head root;                      /* root classes list */
 219     struct list_head hash[HTB_HSIZE];           /* hashed by classid */
 220     struct list_head drops[TC_HTB_NUMPRIO];     /* active leaves (for drops) */
 221
 222     /* self list - roots of self generating tree */
 223     struct rb_root row[TC_HTB_MAXDEPTH][TC_HTB_NUMPRIO];
 224     int row_mask[TC_HTB_MAXDEPTH];
 225     struct rb_node *ptr[TC_HTB_MAXDEPTH][TC_HTB_NUMPRIO];
 226     u32 last_ptr_id[TC_HTB_MAXDEPTH][TC_HTB_NUMPRIO];
 227
 228     /* self wait list - roots of wait PQs per row */
 229     struct rb_root wait_pq[TC_HTB_MAXDEPTH];
 230
 231     /* time of nearest event per level (row) */
 232     unsigned long near_ev_cache[TC_HTB_MAXDEPTH];
 233
 234     /* cached value of jiffies in dequeue */
 235     unsigned long jiffies;
 236
 237     /* whether we hit non-work conserving class during this dequeue; we use */
 238     int nwc_hit;        /* this to disable mindelay complaint in dequeue */
 239
 240     int defcls;         /* class where unclassified flows go to */
 241     u32 debug;          /* subsystem debug levels */
 242
 243     /* filters for qdisc itself */
 244     struct tcf_proto *filter_list;
 245     int filter_cnt;
 246
 247     int rate2quantum;           /* quant = rate / rate2quantum */
 248     psched_time_t now;          /* cached dequeue time */
 249     struct timer_list timer;    /* send delay timer */
 250 #ifdef HTB_RATECM
 251     struct timer_list rttim;    /* rate computer timer */
 252     int recmp_bucket;           /* which hash bucket to recompute next */
 253 #endif
 254
 255     /* non shaped skbs; let them go directly thru */
 256     struct sk_buff_head direct_queue;
 257     int direct_qlen;  /* max qlen of above */
 258
 259     long direct_pkts;
 260 };
 261
 262 /* compute hash of size HTB_HSIZE for given handle */
 263 static __inline__ int htb_hash(u32 h)
 264 {
 265 #if HTB_HSIZE != 16
 266  #error "Declare new hash for your HTB_HSIZE"
 267 #endif
 268     h ^= h>>8;  /* stolen from cbq_hash */
 269     h ^= h>>4;
 270     return h & 0xf;
 271 }
 272
 273 /* find class in global hash table using given handle */
 274 static __inline__ struct htb_class *htb_find(u32 handle, struct Qdisc *sch)
 275 {
 276         struct htb_sched *q = qdisc_priv(sch);
 277         struct list_head *p;
 278         if (TC_H_MAJ(handle) != sch->handle)
 279                 return NULL;
 280
 281         list_for_each (p,q->hash+htb_hash(handle)) {
 282                 struct htb_class *cl = list_entry(p,struct htb_class,hlist);
 283                 if (cl->classid == handle)
 284                         return cl;
 285         }
 286         return NULL;
 287 }
 288
 289 /**
 290  * htb_classify - classify a packet into class
 291  *
 292  * It returns NULL if the packet should be dropped or -1 if the packet
 293  * should be passed directly thru. In all other cases leaf class is returned.
 294  * We allow direct class selection by classid in priority. The we examine
 295  * filters in qdisc and in inner nodes (if higher filter points to the inner
 296  * node). If we end up with classid MAJOR:0 we enqueue the skb into special
 297  * internal fifo (direct). These packets then go directly thru. If we still
 298  * have no valid leaf we try to use MAJOR:default leaf. It still unsuccessfull
 299  * then finish and return direct queue.
 300  */
 301 #define HTB_DIRECT (struct htb_class*)-1
 302 static inline u32 htb_classid(struct htb_class *cl)
 303 {
 304         return (cl && cl != HTB_DIRECT) ? cl->classid : TC_H_UNSPEC;
 305 }
 306
 307 static struct htb_class *htb_classify(struct sk_buff *skb, struct Qdisc *sch, int *qres)
 308 {
 309         struct htb_sched *q = qdisc_priv(sch);
 310         struct htb_class *cl;
 311         struct tcf_result res;
 312         struct tcf_proto *tcf;
 313         int result;
 314
 315         /* allow to select class by setting skb->priority to valid classid;
 316            note that nfmark can be used too by attaching filter fw with no
 317            rules in it */
 318         if (skb->priority == sch->handle)
 319                 return HTB_DIRECT;  /* X:0 (direct flow) selected */
 320         if ((cl = htb_find(skb->priority,sch)) != NULL && cl->level == 0)
 321                 return cl;
 322
 323         tcf = q->filter_list;
 324         while (tcf && (result = tc_classify(skb, tcf, &res)) >= 0) {
 325 #ifdef CONFIG_NET_CLS_ACT
 326                 int terminal = 0;
 327                 switch (result) {
 328                 case TC_ACT_SHOT: /* Stop and kfree */
 329                         *qres = NET_XMIT_DROP;
 330                         terminal = 1;
 331                         break;
 332                 case TC_ACT_QUEUED:
 333                 case TC_ACT_STOLEN:
 334                         terminal = 1;
 335                         break;
 336                 case TC_ACT_RECLASSIFY:  /* Things look good */
 337                 case TC_ACT_OK:
 338                 case TC_ACT_UNSPEC:
 339                 default:
 340                 break;
 341                 }
 342
 343                 if (terminal) {
 344                         kfree_skb(skb);
 345                         return NULL;
 346                 }
 347 #else
 348 #ifdef CONFIG_NET_CLS_POLICE
 349                 if (result == TC_POLICE_SHOT)
 350                         return NULL;
 351 #endif
 352 #endif
 353                 if ((cl = (void*)res.class) == NULL) {
 354                         if (res.classid == sch->handle)
 355                                 return HTB_DIRECT;  /* X:0 (direct flow) */
 356                         if ((cl = htb_find(res.classid,sch)) == NULL)
 357                                 break; /* filter selected invalid classid */
 358                 }
 359                 if (!cl->level)
 360                         return cl; /* we hit leaf; return it */
 361
 362                 /* we have got inner class; apply inner filter chain */
 363                 tcf = cl->filter_list;
 364         }
 365         /* classification failed; try to use default class */
 366         cl = htb_find(TC_H_MAKE(TC_H_MAJ(sch->handle),q->defcls),sch);
 367         if (!cl || cl->level)
 368                 return HTB_DIRECT; /* bad default .. this is safe bet */
 369         return cl;
 370 }
 371
 372 #ifdef HTB_DEBUG
 373 static void htb_next_rb_node(struct rb_node **n);
 374 #define HTB_DUMTREE(root,memb) if(root) { \
 375         struct rb_node *n = (root)->rb_node; \
 376         while (n->rb_left) n = n->rb_left; \
 377         while (n) { \
 378                 struct htb_class *cl = rb_entry(n, struct htb_class, memb); \
 379                 printk(" %x",cl->classid); htb_next_rb_node (&n); \
 380         } }
 381
 382 static void htb_debug_dump (struct htb_sched *q)
 383 {
 384         int i,p;
 385         printk(KERN_DEBUG "htb*g j=%lu lj=%lu\n",jiffies,q->jiffies);
 386         /* rows */
 387         for (i=TC_HTB_MAXDEPTH-1;i>=0;i--) {
 388                 printk(KERN_DEBUG "htb*r%d m=%x",i,q->row_mask[i]);
 389                 for (p=0;p<TC_HTB_NUMPRIO;p++) {
 390                         if (!q->row[i][p].rb_node) continue;
 391                         printk(" p%d:",p);
 392                         HTB_DUMTREE(q->row[i]+p,node[p]);
 393                 }
 394                 printk("\n");
 395         }
 396         /* classes */
 397         for (i = 0; i < HTB_HSIZE; i++) {
 398                 struct list_head *l;
 399                 list_for_each (l,q->hash+i) {
 400                         struct htb_class *cl = list_entry(l,struct htb_class,hlist);
 401                         long diff = PSCHED_TDIFF_SAFE(q->now, cl->t_c, (u32)cl->mbuffer);
 402                         printk(KERN_DEBUG "htb*c%x m=%d t=%ld c=%ld pq=%lu df=%ld ql=%d "
 403                                         "pa=%x f:",
 404                                 cl->classid,cl->cmode,cl->tokens,cl->ctokens,
 405                                 cl->pq_node.rb_color==-1?0:cl->pq_key,diff,
 406                                 cl->level?0:cl->un.leaf.q->q.qlen,cl->prio_activity);
 407                         if (cl->level)
 408                         for (p=0;p<TC_HTB_NUMPRIO;p++) {
 409                                 if (!cl->un.inner.feed[p].rb_node) continue;
 410                                 printk(" p%d a=%x:",p,cl->un.inner.ptr[p]?rb_entry(cl->un.inner.ptr[p], struct htb_class,node[p])->classid:0);
 411                                 HTB_DUMTREE(cl->un.inner.feed+p,node[p]);
 412                         }
 413                         printk("\n");
 414                 }
 415         }
 416 }
 417 #endif
 418 /**
 419  * htb_add_to_id_tree - adds class to the round robin list
 420  *
 421  * Routine adds class to the list (actually tree) sorted by classid.
 422  * Make sure that class is not already on such list for given prio.
 423  */
 424 static void htb_add_to_id_tree (HTB_ARGQ struct rb_root *root,
 425                 struct htb_class *cl,int prio)
 426 {
 427         struct rb_node **p = &root->rb_node, *parent = NULL;
 428         HTB_DBG(7,3,"htb_add_id_tree cl=%X prio=%d\n",cl->classid,prio);
 429 #ifdef HTB_DEBUG
 430         if (cl->node[prio].rb_color != -1) { BUG_TRAP(0); return; }
 431         HTB_CHCL(cl);
 432         if (*p) {
 433                 struct htb_class *x = rb_entry(*p,struct htb_class,node[prio]);
 434                 HTB_CHCL(x);
 435         }
 436 #endif
 437         while (*p) {
 438                 struct htb_class *c; parent = *p;
 439                 c = rb_entry(parent, struct htb_class, node[prio]);
 440                 HTB_CHCL(c);
 441                 if (cl->classid > c->classid)
 442                         p = &parent->rb_right;
 443                 else
 444                         p = &parent->rb_left;
 445         }
 446         rb_link_node(&cl->node[prio], parent, p);
 447         rb_insert_color(&cl->node[prio], root);
 448 }
 449
 450 /**
 451  * htb_add_to_wait_tree - adds class to the event queue with delay
 452  *
 453  * The class is added to priority event queue to indicate that class will
 454  * change its mode in cl->pq_key microseconds. Make sure that class is not
 455  * already in the queue.
 456  */
 457 static void htb_add_to_wait_tree (struct htb_sched *q,
 458                 struct htb_class *cl,long delay,int debug_hint)
 459 {
 460         struct rb_node **p = &q->wait_pq[cl->level].rb_node, *parent = NULL;
 461         HTB_DBG(7,3,"htb_add_wt cl=%X key=%lu\n",cl->classid,cl->pq_key);
 462 #ifdef HTB_DEBUG
 463         if (cl->pq_node.rb_color != -1) { BUG_TRAP(0); return; }
 464         HTB_CHCL(cl);
 465         if ((delay <= 0 || delay > cl->mbuffer) && net_ratelimit())
 466                 printk(KERN_ERR "HTB: suspicious delay in wait_tree d=%ld cl=%X h=%d\n",delay,cl->classid,debug_hint);
 467 #endif
 468         cl->pq_key = q->jiffies + PSCHED_US2JIFFIE(delay);
 469         if (cl->pq_key == q->jiffies)
 470                 cl->pq_key++;
 471
 472         /* update the nearest event cache */
 473         if (time_after(q->near_ev_cache[cl->level], cl->pq_key))
 474                 q->near_ev_cache[cl->level] = cl->pq_key;
 475
 476         while (*p) {
 477                 struct htb_class *c; parent = *p;
 478                 c = rb_entry(parent, struct htb_class, pq_node);
 479                 if (time_after_eq(cl->pq_key, c->pq_key))
 480                         p = &parent->rb_right;
 481                 else
 482                         p = &parent->rb_left;
 483         }
 484         rb_link_node(&cl->pq_node, parent, p);
 485         rb_insert_color(&cl->pq_node, &q->wait_pq[cl->level]);
 486 }
 487
 488 /**
 489  * htb_next_rb_node - finds next node in binary tree
 490  *
 491  * When we are past last key we return NULL.
 492  * Average complexity is 2 steps per call.
 493  */
 494 static void htb_next_rb_node(struct rb_node **n)
 495 {
 496         *n = rb_next(*n);
 497 }
 498
 499 /**
 500  * htb_add_class_to_row - add class to its row
 501  *
 502  * The class is added to row at priorities marked in mask.
 503  * It does nothing if mask == 0.
 504  */
 505 static inline void htb_add_class_to_row(struct htb_sched *q,
 506                 struct htb_class *cl,int mask)
 507 {
 508         HTB_DBG(7,2,"htb_addrow cl=%X mask=%X rmask=%X\n",
 509                         cl->classid,mask,q->row_mask[cl->level]);
 510         HTB_CHCL(cl);
 511         q->row_mask[cl->level] |= mask;
 512         while (mask) {
 513                 int prio = ffz(~mask);
 514                 mask &= ~(1 << prio);
 515                 htb_add_to_id_tree(HTB_PASSQ q->row[cl->level]+prio,cl,prio);
 516         }
 517 }
 518
 519 /**
 520  * htb_remove_class_from_row - removes class from its row
 521  *
 522  * The class is removed from row at priorities marked in mask.
 523  * It does nothing if mask == 0.
 524  */
 525 static __inline__ void htb_remove_class_from_row(struct htb_sched *q,
 526                 struct htb_class *cl,int mask)
 527 {
 528         int m = 0;
 529         HTB_CHCL(cl);
 530         while (mask) {
 531                 int prio = ffz(~mask);
 532                 mask &= ~(1 << prio);
 533                 if (q->ptr[cl->level][prio] == cl->node+prio)
 534                         htb_next_rb_node(q->ptr[cl->level]+prio);
 535                 htb_safe_rb_erase(cl->node + prio,q->row[cl->level]+prio);
 536                 if (!q->row[cl->level][prio].rb_node)
 537                         m |= 1 << prio;
 538         }
 539         HTB_DBG(7,2,"htb_delrow cl=%X mask=%X rmask=%X maskdel=%X\n",
 540                         cl->classid,mask,q->row_mask[cl->level],m);
 541         q->row_mask[cl->level] &= ~m;
 542 }
 543
 544 /**
 545  * htb_activate_prios - creates active classe's feed chain
 546  *
 547  * The class is connected to ancestors and/or appropriate rows
 548  * for priorities it is participating on. cl->cmode must be new
 549  * (activated) mode. It does nothing if cl->prio_activity == 0.
 550  */
 551 static void htb_activate_prios(struct htb_sched *q,struct htb_class *cl)
 552 {
 553         struct htb_class *p = cl->parent;
 554         long m,mask = cl->prio_activity;
 555         HTB_DBG(7,2,"htb_act_prios cl=%X mask=%lX cmode=%d\n",cl->classid,mask,cl->cmode);
 556         HTB_CHCL(cl);
 557
 558         while (cl->cmode == HTB_MAY_BORROW && p && mask) {
 559                 HTB_CHCL(p);
 560                 m = mask; while (m) {
 561                         int prio = ffz(~m);
 562                         m &= ~(1 << prio);
 563
 564                         if (p->un.inner.feed[prio].rb_node)
 565                                 /* parent already has its feed in use so that
 566                                    reset bit in mask as parent is already ok */
 567                                 mask &= ~(1 << prio);
 568
 569                         htb_add_to_id_tree(HTB_PASSQ p->un.inner.feed+prio,cl,prio);
 570                 }
 571                 HTB_DBG(7,3,"htb_act_pr_aft p=%X pact=%X mask=%lX pmode=%d\n",
 572                                 p->classid,p->prio_activity,mask,p->cmode);
 573                 p->prio_activity |= mask;
 574                 cl = p; p = cl->parent;
 575                 HTB_CHCL(cl);
 576         }
 577         if (cl->cmode == HTB_CAN_SEND && mask)
 578                 htb_add_class_to_row(q,cl,mask);
 579 }
 580
 581 /**
 582  * htb_deactivate_prios - remove class from feed chain
 583  *
 584  * cl->cmode must represent old mode (before deactivation). It does
 585  * nothing if cl->prio_activity == 0. Class is removed from all feed
 586  * chains and rows.
 587  */
 588 static void htb_deactivate_prios(struct htb_sched *q, struct htb_class *cl)
 589 {
 590         struct htb_class *p = cl->parent;
 591         long m,mask = cl->prio_activity;
 592         HTB_DBG(7,2,"htb_deact_prios cl=%X mask=%lX cmode=%d\n",cl->classid,mask,cl->cmode);
 593         HTB_CHCL(cl);
 594
 595         while (cl->cmode == HTB_MAY_BORROW && p && mask) {
 596                 m = mask; mask = 0;
 597                 while (m) {
 598                         int prio = ffz(~m);
 599                         m &= ~(1 << prio);
 600
 601                         if (p->un.inner.ptr[prio] == cl->node+prio) {
 602                                 /* we are removing child which is pointed to from
 603                                    parent feed - forget the pointer but remember
 604                                    classid */
 605                                 p->un.inner.last_ptr_id[prio] = cl->classid;
 606                                 p->un.inner.ptr[prio] = NULL;
 607                         }
 608
 609                         htb_safe_rb_erase(cl->node + prio,p->un.inner.feed + prio);
 610
 611                         if (!p->un.inner.feed[prio].rb_node)
 612                                 mask |= 1 << prio;
 613                 }
 614                 HTB_DBG(7,3,"htb_deact_pr_aft p=%X pact=%X mask=%lX pmode=%d\n",
 615                                 p->classid,p->prio_activity,mask,p->cmode);
 616                 p->prio_activity &= ~mask;
 617                 cl = p; p = cl->parent;
 618                 HTB_CHCL(cl);
 619         }
 620         if (cl->cmode == HTB_CAN_SEND && mask)
 621                 htb_remove_class_from_row(q,cl,mask);
 622 }
 623
 624 /**
 625  * htb_class_mode - computes and returns current class mode
 626  *
 627  * It computes cl's mode at time cl->t_c+diff and returns it. If mode
 628  * is not HTB_CAN_SEND then cl->pq_key is updated to time difference
 629  * from now to time when cl will change its state.
 630  * Also it is worth to note that class mode doesn't change simply
 631  * at cl->{c,}tokens == 0 but there can rather be hysteresis of
 632  * 0 .. -cl->{c,}buffer range. It is meant to limit number of
 633  * mode transitions per time unit. The speed gain is about 1/6.
 634  */
 635 static __inline__ enum htb_cmode
 636 htb_class_mode(struct htb_class *cl,long *diff)
 637 {
 638     long toks;
 639
 640     if ((toks = (cl->ctokens + *diff)) < (
 641 #if HTB_HYSTERESIS
 642             cl->cmode != HTB_CANT_SEND ? -cl->cbuffer :
 643 #endif
 644             0)) {
 645             *diff = -toks;
 646             return HTB_CANT_SEND;
 647     }
 648     if ((toks = (cl->tokens + *diff)) >= (
 649 #if HTB_HYSTERESIS
 650             cl->cmode == HTB_CAN_SEND ? -cl->buffer :
 651 #endif
 652             0))
 653             return HTB_CAN_SEND;
 654
 655     *diff = -toks;
 656     return HTB_MAY_BORROW;
 657 }
 658
 659 /**
 660  * htb_change_class_mode - changes classe's mode
 661  *
 662  * This should be the only way how to change classe's mode under normal
 663  * cirsumstances. Routine will update feed lists linkage, change mode
 664  * and add class to the wait event queue if appropriate. New mode should
 665  * be different from old one and cl->pq_key has to be valid if changing
 666  * to mode other than HTB_CAN_SEND (see htb_add_to_wait_tree).
 667  */
 668 static void
 669 htb_change_class_mode(struct htb_sched *q, struct htb_class *cl, long *diff)
 670 {
 671         enum htb_cmode new_mode = htb_class_mode(cl,diff);
 672
 673         HTB_CHCL(cl);
 674         HTB_DBG(7,1,"htb_chging_clmode %d->%d cl=%X\n",cl->cmode,new_mode,cl->classid);
 675
 676         if (new_mode == cl->cmode)
 677                 return;
 678
 679         if (cl->prio_activity) { /* not necessary: speed optimization */
 680                 if (cl->cmode != HTB_CANT_SEND)
 681                         htb_deactivate_prios(q,cl);
 682                 cl->cmode = new_mode;
 683                 if (new_mode != HTB_CANT_SEND)
 684                         htb_activate_prios(q,cl);
 685         } else
 686                 cl->cmode = new_mode;
 687 }
 688
 689 /**
 690  * htb_activate - inserts leaf cl into appropriate active feeds
 691  *
 692  * Routine learns (new) priority of leaf and activates feed chain
 693  * for the prio. It can be called on already active leaf safely.
 694  * It also adds leaf into droplist.
 695  */
 696 static __inline__ void htb_activate(struct htb_sched *q,struct htb_class *cl)
 697 {
 698         BUG_TRAP(!cl->level && cl->un.leaf.q && cl->un.leaf.q->q.qlen);
 699         HTB_CHCL(cl);
 700         if (!cl->prio_activity) {
 701                 cl->prio_activity = 1 << (cl->un.leaf.aprio = cl->un.leaf.prio);
 702                 htb_activate_prios(q,cl);
 703                 list_add_tail(&cl->un.leaf.drop_list,q->drops+cl->un.leaf.aprio);
 704         }
 705 }
 706
 707 /**
 708  * htb_deactivate - remove leaf cl from active feeds
 709  *
 710  * Make sure that leaf is active. In the other words it can't be called
 711  * with non-active leaf. It also removes class from the drop list.
 712  */
 713 static __inline__ void
 714 htb_deactivate(struct htb_sched *q,struct htb_class *cl)
 715 {
 716         BUG_TRAP(cl->prio_activity);
 717         HTB_CHCL(cl);
 718         htb_deactivate_prios(q,cl);
 719         cl->prio_activity = 0;
 720         list_del_init(&cl->un.leaf.drop_list);
 721 }
 722
 723 static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 724 {
 725     int ret = NET_XMIT_SUCCESS;
 726     struct htb_sched *q = qdisc_priv(sch);
 727     struct htb_class *cl = htb_classify(skb,sch,&ret);
 728
 729
 730 #ifdef CONFIG_NET_CLS_ACT
 731     if (cl == HTB_DIRECT ) {
 732         if (q->direct_queue.qlen < q->direct_qlen ) {
 733             __skb_queue_tail(&q->direct_queue, skb);
 734             q->direct_pkts++;
 735         }
 736     } else if (!cl) {
 737             if (NET_XMIT_DROP == ret) {
 738                     sch->stats.drops++;
 739             }
 740             return ret;
 741     }
 742 #else
 743     if (cl == HTB_DIRECT || !cl) {
 744         /* enqueue to helper queue */
 745         if (q->direct_queue.qlen < q->direct_qlen && cl) {
 746             __skb_queue_tail(&q->direct_queue, skb);
 747             q->direct_pkts++;
 748         } else {
 749             kfree_skb (skb);
 750             sch->stats.drops++;
 751             return NET_XMIT_DROP;
 752         }
 753     }
 754 #endif
 755     else if (cl->un.leaf.q->enqueue(skb, cl->un.leaf.q) != NET_XMIT_SUCCESS) {
 756         sch->stats.drops++;
 757         cl->stats.drops++;
 758         return NET_XMIT_DROP;
 759     } else {
 760         cl->stats.packets++; cl->stats.bytes += skb->len;
 761         htb_activate (q,cl);
 762     }
 763
 764     sch->q.qlen++;
 765     sch->stats.packets++; sch->stats.bytes += skb->len;
 766     HTB_DBG(1,1,"htb_enq_ok cl=%X skb=%p\n",(cl && cl != HTB_DIRECT)?cl->classid:0,skb);
 767     return NET_XMIT_SUCCESS;
 768 }
 769
 770 /* TODO: requeuing packet charges it to policers again !! */
 771 static int htb_requeue(struct sk_buff *skb, struct Qdisc *sch)
 772 {
 773     struct htb_sched *q = qdisc_priv(sch);
 774     int ret =  NET_XMIT_SUCCESS;
 775     struct htb_class *cl = htb_classify(skb,sch, &ret);
 776     struct sk_buff *tskb;
 777
 778     if (cl == HTB_DIRECT || !cl) {
 779         /* enqueue to helper queue */
 780         if (q->direct_queue.qlen < q->direct_qlen && cl) {
 781             __skb_queue_head(&q->direct_queue, skb);
 782         } else {
 783             __skb_queue_head(&q->direct_queue, skb);
 784             tskb = __skb_dequeue_tail(&q->direct_queue);
 785             kfree_skb (tskb);
 786             sch->stats.drops++;
 787             return NET_XMIT_CN;
 788         }
 789     } else if (cl->un.leaf.q->ops->requeue(skb, cl->un.leaf.q) != NET_XMIT_SUCCESS) {
 790         sch->stats.drops++;
 791         cl->stats.drops++;
 792         return NET_XMIT_DROP;
 793     } else
 794             htb_activate (q,cl);
 795
 796     sch->q.qlen++;
 797     HTB_DBG(1,1,"htb_req_ok cl=%X skb=%p\n",(cl && cl != HTB_DIRECT)?cl->classid:0,skb);
 798     return NET_XMIT_SUCCESS;
 799 }
 800
 801 static void htb_timer(unsigned long arg)
 802 {
 803     struct Qdisc *sch = (struct Qdisc*)arg;
 804     sch->flags &= ~TCQ_F_THROTTLED;
 805     wmb();
 806     netif_schedule(sch->dev);
 807 }
 808
 809 #ifdef HTB_RATECM
 810 #define RT_GEN(D,R) R+=D-(R/HTB_EWMAC);D=0
 811 static void htb_rate_timer(unsigned long arg)
 812 {
 813         struct Qdisc *sch = (struct Qdisc*)arg;
 814         struct htb_sched *q = qdisc_priv(sch);
 815         struct list_head *p;
 816
 817         /* lock queue so that we can muck with it */
 818         HTB_QLOCK(sch);
 819         HTB_DBG(10,1,"htb_rttmr j=%ld\n",jiffies);
 820
 821         q->rttim.expires = jiffies + HZ;
 822         add_timer(&q->rttim);
 823
 824         /* scan and recompute one bucket at time */
 825         if (++q->recmp_bucket >= HTB_HSIZE)
 826                 q->recmp_bucket = 0;
 827         list_for_each (p,q->hash+q->recmp_bucket) {
 828                 struct htb_class *cl = list_entry(p,struct htb_class,hlist);
 829                 HTB_DBG(10,2,"htb_rttmr_cl cl=%X sbyte=%lu spkt=%lu\n",
 830                                 cl->classid,cl->sum_bytes,cl->sum_packets);
 831                 RT_GEN (cl->sum_bytes,cl->rate_bytes);
 832                 RT_GEN (cl->sum_packets,cl->rate_packets);
 833         }
 834         HTB_QUNLOCK(sch);
 835 }
 836 #endif
 837
 838 /**
 839  * htb_charge_class - charges amount "bytes" to leaf and ancestors
 840  *
 841  * Routine assumes that packet "bytes" long was dequeued from leaf cl
 842  * borrowing from "level". It accounts bytes to ceil leaky bucket for
 843  * leaf and all ancestors and to rate bucket for ancestors at levels
 844  * "level" and higher. It also handles possible change of mode resulting
 845  * from the update. Note that mode can also increase here (MAY_BORROW to
 846  * CAN_SEND) because we can use more precise clock that event queue here.
 847  * In such case we remove class from event queue first.
 848  */
 849 static void htb_charge_class(struct htb_sched *q,struct htb_class *cl,
 850                 int level,int bytes)
 851 {
 852         long toks,diff;
 853         enum htb_cmode old_mode;
 854         HTB_DBG(5,1,"htb_chrg_cl cl=%X lev=%d len=%d\n",cl->classid,level,bytes);
 855
 856 #define HTB_ACCNT(T,B,R) toks = diff + cl->T; \
 857         if (toks > cl->B) toks = cl->B; \
 858         toks -= L2T(cl, cl->R, bytes); \
 859         if (toks <= -cl->mbuffer) toks = 1-cl->mbuffer; \
 860         cl->T = toks
 861
 862         while (cl) {
 863                 HTB_CHCL(cl);
 864                 diff = PSCHED_TDIFF_SAFE(q->now, cl->t_c, (u32)cl->mbuffer);
 865 #ifdef HTB_DEBUG
 866                 if (diff > cl->mbuffer || diff < 0 || PSCHED_TLESS(q->now, cl->t_c)) {
 867                         if (net_ratelimit())
 868                                 printk(KERN_ERR "HTB: bad diff in charge, cl=%X diff=%lX now=%Lu then=%Lu j=%lu\n",
 869                                        cl->classid, diff,
 870 #ifdef CONFIG_NET_SCH_CLK_GETTIMEOFDAY
 871                                        q->now.tv_sec * 1000000ULL + q->now.tv_usec,
 872                                        cl->t_c.tv_sec * 1000000ULL + cl->t_c.tv_usec,
 873 #else
 874                                        (unsigned long long) q->now,
 875                                        (unsigned long long) cl->t_c,
 876 #endif
 877                                        q->jiffies);
 878                         diff = 1000;
 879                 }
 880 #endif
 881                 if (cl->level >= level) {
 882                         if (cl->level == level) cl->xstats.lends++;
 883                         HTB_ACCNT (tokens,buffer,rate);
 884                 } else {
 885                         cl->xstats.borrows++;
 886                         cl->tokens += diff; /* we moved t_c; update tokens */
 887                 }
 888                 HTB_ACCNT (ctokens,cbuffer,ceil);
 889                 cl->t_c = q->now;
 890                 HTB_DBG(5,2,"htb_chrg_clp cl=%X diff=%ld tok=%ld ctok=%ld\n",cl->classid,diff,cl->tokens,cl->ctokens);
 891
 892                 old_mode = cl->cmode; diff = 0;
 893                 htb_change_class_mode(q,cl,&diff);
 894                 if (old_mode != cl->cmode) {
 895                         if (old_mode != HTB_CAN_SEND)
 896                                 htb_safe_rb_erase(&cl->pq_node,q->wait_pq+cl->level);
 897                         if (cl->cmode != HTB_CAN_SEND)
 898                                 htb_add_to_wait_tree (q,cl,diff,1);
 899                 }
 900
 901 #ifdef HTB_RATECM
 902                 /* update rate counters */
 903                 cl->sum_bytes += bytes; cl->sum_packets++;
 904 #endif
 905
 906                 /* update byte stats except for leaves which are already updated */
 907                 if (cl->level) {
 908                         cl->stats.bytes += bytes;
 909                         cl->stats.packets++;
 910                 }
 911                 cl = cl->parent;
 912         }
 913 }
 914
 915 /**
 916  * htb_do_events - make mode changes to classes at the level
 917  *
 918  * Scans event queue for pending events and applies them. Returns jiffies to
 919  * next pending event (0 for no event in pq).
 920  * Note: Aplied are events whose have cl->pq_key <= jiffies.
 921  */
 922 static long htb_do_events(struct htb_sched *q,int level)
 923 {
 924         int i;
 925         HTB_DBG(8,1,"htb_do_events l=%d root=%p rmask=%X\n",
 926                         level,q->wait_pq[level].rb_node,q->row_mask[level]);
 927         for (i = 0; i < 500; i++) {
 928                 struct htb_class *cl;
 929                 long diff;
 930                 struct rb_node *p = q->wait_pq[level].rb_node;
 931                 if (!p) return 0;
 932                 while (p->rb_left) p = p->rb_left;
 933
 934                 cl = rb_entry(p, struct htb_class, pq_node);
 935                 if (time_after(cl->pq_key, q->jiffies)) {
 936                         HTB_DBG(8,3,"htb_do_ev_ret delay=%ld\n",cl->pq_key - q->jiffies);
 937                         return cl->pq_key - q->jiffies;
 938                 }
 939                 htb_safe_rb_erase(p,q->wait_pq+level);
 940                 diff = PSCHED_TDIFF_SAFE(q->now, cl->t_c, (u32)cl->mbuffer);
 941 #ifdef HTB_DEBUG
 942                 if (diff > cl->mbuffer || diff < 0 || PSCHED_TLESS(q->now, cl->t_c)) {
 943                         if (net_ratelimit())
 944                                 printk(KERN_ERR "HTB: bad diff in events, cl=%X diff=%lX now=%Lu then=%Lu j=%lu\n",
 945                                        cl->classid, diff,
 946 #ifdef CONFIG_NET_SCH_CLK_GETTIMEOFDAY
 947                                        q->now.tv_sec * 1000000ULL + q->now.tv_usec,
 948                                        cl->t_c.tv_sec * 1000000ULL + cl->t_c.tv_usec,
 949 #else
 950                                        (unsigned long long) q->now,
 951                                        (unsigned long long) cl->t_c,
 952 #endif
 953                                        q->jiffies);
 954                         diff = 1000;
 955                 }
 956 #endif
 957                 htb_change_class_mode(q,cl,&diff);
 958                 if (cl->cmode != HTB_CAN_SEND)
 959                         htb_add_to_wait_tree (q,cl,diff,2);
 960         }
 961         if (net_ratelimit())
 962                 printk(KERN_WARNING "htb: too many events !\n");
 963         return HZ/10;
 964 }
 965
 966 /* Returns class->node+prio from id-tree where classe's id is >= id. NULL
 967    is no such one exists. */
 968 static struct rb_node *
 969 htb_id_find_next_upper(int prio,struct rb_node *n,u32 id)
 970 {
 971         struct rb_node *r = NULL;
 972         while (n) {
 973                 struct htb_class *cl = rb_entry(n,struct htb_class,node[prio]);
 974                 if (id == cl->classid) return n;
 975
 976                 if (id > cl->classid) {
 977                         n = n->rb_right;
 978                 } else {
 979                         r = n;
 980                         n = n->rb_left;
 981                 }
 982         }
 983         return r;
 984 }
 985
 986 /**
 987  * htb_lookup_leaf - returns next leaf class in DRR order
 988  *
 989  * Find leaf where current feed pointers points to.
 990  */
 991 static struct htb_class *
 992 htb_lookup_leaf(HTB_ARGQ struct rb_root *tree,int prio,struct rb_node **pptr,u32 *pid)
 993 {
 994         int i;
 995         struct {
 996                 struct rb_node *root;
 997                 struct rb_node **pptr;
 998                 u32 *pid;
 999         } stk[TC_HTB_MAXDEPTH],*sp = stk;
1000
1001         BUG_TRAP(tree->rb_node);
1002         sp->root = tree->rb_node;
1003         sp->pptr = pptr;
1004         sp->pid = pid;
1005
1006         for (i = 0; i < 65535; i++) {
1007                 HTB_DBG(4,2,"htb_lleaf ptr=%p pid=%X\n",*sp->pptr,*sp->pid);
1008
1009                 if (!*sp->pptr && *sp->pid) {
1010                         /* ptr was invalidated but id is valid - try to recover
1011                            the original or next ptr */
1012                         *sp->pptr = htb_id_find_next_upper(prio,sp->root,*sp->pid);
1013                 }
1014                 *sp->pid = 0; /* ptr is valid now so that remove this hint as it
1015                                  can become out of date quickly */
1016                 if (!*sp->pptr) { /* we are at right end; rewind & go up */
1017                         *sp->pptr = sp->root;
1018                         while ((*sp->pptr)->rb_left)
1019                                 *sp->pptr = (*sp->pptr)->rb_left;
1020                         if (sp > stk) {
1021                                 sp--;
1022                                 BUG_TRAP(*sp->pptr); if(!*sp->pptr) return NULL;
1023                                 htb_next_rb_node (sp->pptr);
1024                         }
1025                 } else {
1026                         struct htb_class *cl;
1027                         cl = rb_entry(*sp->pptr,struct htb_class,node[prio]);
1028                         HTB_CHCL(cl);
1029                         if (!cl->level)
1030                                 return cl;
1031                         (++sp)->root = cl->un.inner.feed[prio].rb_node;
1032                         sp->pptr = cl->un.inner.ptr+prio;
1033                         sp->pid = cl->un.inner.last_ptr_id+prio;
1034                 }
1035         }
1036         BUG_TRAP(0);
1037         return NULL;
1038 }
1039
1040 /* dequeues packet at given priority and level; call only if
1041    you are sure that there is active class at prio/level */
1042 static struct sk_buff *
1043 htb_dequeue_tree(struct htb_sched *q,int prio,int level)
1044 {
1045         struct sk_buff *skb = NULL;
1046         struct htb_class *cl,*start;
1047         /* look initial class up in the row */
1048         start = cl = htb_lookup_leaf (HTB_PASSQ q->row[level]+prio,prio,
1049                         q->ptr[level]+prio,q->last_ptr_id[level]+prio);
1050
1051         do {
1052 next:
1053                 BUG_TRAP(cl);
1054                 if (!cl) return NULL;
1055                 HTB_DBG(4,1,"htb_deq_tr prio=%d lev=%d cl=%X defic=%d\n",
1056                                 prio,level,cl->classid,cl->un.leaf.deficit[level]);
1057
1058                 /* class can be empty - it is unlikely but can be true if leaf
1059                    qdisc drops packets in enqueue routine or if someone used
1060                    graft operation on the leaf since last dequeue;
1061                    simply deactivate and skip such class */
1062                 if (unlikely(cl->un.leaf.q->q.qlen == 0)) {
1063                         struct htb_class *next;
1064                         htb_deactivate(q,cl);
1065
1066                         /* row/level might become empty */
1067                         if ((q->row_mask[level] & (1 << prio)) == 0)
1068                                 return NULL;
1069
1070                         next = htb_lookup_leaf (HTB_PASSQ q->row[level]+prio,
1071                                         prio,q->ptr[level]+prio,q->last_ptr_id[level]+prio);
1072
1073                         if (cl == start) /* fix start if we just deleted it */
1074                                 start = next;
1075                         cl = next;
1076                         goto next;
1077                 }
1078
1079                 if (likely((skb = cl->un.leaf.q->dequeue(cl->un.leaf.q)) != NULL))
1080                         break;
1081                 if (!cl->warned) {
1082                         printk(KERN_WARNING "htb: class %X isn't work conserving ?!\n",cl->classid);
1083                         cl->warned = 1;
1084                 }
1085                 q->nwc_hit++;
1086                 htb_next_rb_node((level?cl->parent->un.inner.ptr:q->ptr[0])+prio);
1087                 cl = htb_lookup_leaf (HTB_PASSQ q->row[level]+prio,prio,q->ptr[level]+prio,
1088                                 q->last_ptr_id[level]+prio);
1089
1090         } while (cl != start);
1091
1092         if (likely(skb != NULL)) {
1093                 if ((cl->un.leaf.deficit[level] -= skb->len) < 0) {
1094                         HTB_DBG(4,2,"htb_next_cl oldptr=%p quant_add=%d\n",
1095                                 level?cl->parent->un.inner.ptr[prio]:q->ptr[0][prio],cl->un.leaf.quantum);
1096                         cl->un.leaf.deficit[level] += cl->un.leaf.quantum;
1097                         htb_next_rb_node((level?cl->parent->un.inner.ptr:q->ptr[0])+prio);
1098                 }
1099                 /* this used to be after charge_class but this constelation
1100                    gives us slightly better performance */
1101                 if (!cl->un.leaf.q->q.qlen)
1102                         htb_deactivate (q,cl);
1103                 htb_charge_class (q,cl,level,skb->len);
1104         }
1105         return skb;
1106 }
1107
1108 static void htb_delay_by(struct Qdisc *sch,long delay)
1109 {
1110         struct htb_sched *q = qdisc_priv(sch);
1111         if (delay <= 0) delay = 1;
1112         if (unlikely(delay > 5*HZ)) {
1113                 if (net_ratelimit())
1114                         printk(KERN_INFO "HTB delay %ld > 5sec\n", delay);
1115                 delay = 5*HZ;
1116         }
1117         /* why don't use jiffies here ? because expires can be in past */
1118         mod_timer(&q->timer, q->jiffies + delay);
1119         sch->flags |= TCQ_F_THROTTLED;
1120         sch->stats.overlimits++;
1121         HTB_DBG(3,1,"htb_deq t_delay=%ld\n",delay);
1122 }
1123
1124 static struct sk_buff *htb_dequeue(struct Qdisc *sch)
1125 {
1126         struct sk_buff *skb = NULL;
1127         struct htb_sched *q = qdisc_priv(sch);
1128         int level;
1129         long min_delay;
1130 #ifdef HTB_DEBUG
1131         int evs_used = 0;
1132 #endif
1133
1134         q->jiffies = jiffies;
1135         HTB_DBG(3,1,"htb_deq dircnt=%d qlen=%d\n",skb_queue_len(&q->direct_queue),
1136                         sch->q.qlen);
1137
1138         /* try to dequeue direct packets as high prio (!) to minimize cpu work */
1139         if ((skb = __skb_dequeue(&q->direct_queue)) != NULL) {
1140                 sch->flags &= ~TCQ_F_THROTTLED;
1141                 sch->q.qlen--;
1142                 return skb;
1143         }
1144
1145         if (!sch->q.qlen) goto fin;
1146         PSCHED_GET_TIME(q->now);
1147
1148         min_delay = LONG_MAX;
1149         q->nwc_hit = 0;
1150         for (level = 0; level < TC_HTB_MAXDEPTH; level++) {
1151                 /* common case optimization - skip event handler quickly */
1152                 int m;
1153                 long delay;
1154                 if (time_after_eq(q->jiffies, q->near_ev_cache[level])) {
1155                         delay = htb_do_events(q,level);
1156                         q->near_ev_cache[level] = q->jiffies + (delay ? delay : HZ);
1157 #ifdef HTB_DEBUG
1158                         evs_used++;
1159 #endif
1160                 } else
1161                         delay = q->near_ev_cache[level] - q->jiffies;
1162
1163                 if (delay && min_delay > delay)
1164                         min_delay = delay;
1165                 m = ~q->row_mask[level];
1166                 while (m != (int)(-1)) {
1167                         int prio = ffz (m);
1168                         m |= 1 << prio;
1169                         skb = htb_dequeue_tree(q,prio,level);
1170                         if (likely(skb != NULL)) {
1171                                 sch->q.qlen--;
1172                                 sch->flags &= ~TCQ_F_THROTTLED;
1173                                 goto fin;
1174                         }
1175                 }
1176         }
1177 #ifdef HTB_DEBUG
1178         if (!q->nwc_hit && min_delay >= 10*HZ && net_ratelimit()) {
1179                 if (min_delay == LONG_MAX) {
1180                         printk(KERN_ERR "HTB: dequeue bug (%d,%lu,%lu), report it please !\n",
1181                                         evs_used,q->jiffies,jiffies);
1182                         htb_debug_dump(q);
1183                 } else
1184                         printk(KERN_WARNING "HTB: mindelay=%ld, some class has "
1185                                         "too small rate\n",min_delay);
1186         }
1187 #endif
1188         htb_delay_by (sch,min_delay > 5*HZ ? 5*HZ : min_delay);
1189 fin:
1190         HTB_DBG(3,1,"htb_deq_end %s j=%lu skb=%p\n",sch->dev->name,q->jiffies,skb);
1191         return skb;
1192 }
1193
1194 /* try to drop from each class (by prio) until one succeed */
1195 static unsigned int htb_drop(struct Qdisc* sch)
1196 {
1197         struct htb_sched *q = qdisc_priv(sch);
1198         int prio;
1199
1200         for (prio = TC_HTB_NUMPRIO - 1; prio >= 0; prio--) {
1201                 struct list_head *p;
1202                 list_for_each (p,q->drops+prio) {
1203                         struct htb_class *cl = list_entry(p, struct htb_class,
1204                                                           un.leaf.drop_list);
1205                         unsigned int len;
1206                         if (cl->un.leaf.q->ops->drop &&
1207                                 (len = cl->un.leaf.q->ops->drop(cl->un.leaf.q))) {
1208                                 sch->q.qlen--;
1209                                 if (!cl->un.leaf.q->q.qlen)
1210                                         htb_deactivate (q,cl);
1211                                 return len;
1212                         }
1213                 }
1214         }
1215         return 0;
1216 }
1217
1218 /* reset all classes */
1219 /* always caled under BH & queue lock */
1220 static void htb_reset(struct Qdisc* sch)
1221 {
1222         struct htb_sched *q = qdisc_priv(sch);
1223         int i;
1224         HTB_DBG(0,1,"htb_reset sch=%p, handle=%X\n",sch,sch->handle);
1225
1226         for (i = 0; i < HTB_HSIZE; i++) {
1227                 struct list_head *p;
1228                 list_for_each (p,q->hash+i) {
1229                         struct htb_class *cl = list_entry(p,struct htb_class,hlist);
1230                         if (cl->level)
1231                                 memset(&cl->un.inner,0,sizeof(cl->un.inner));
1232                         else {
1233                                 if (cl->un.leaf.q)
1234                                         qdisc_reset(cl->un.leaf.q);
1235                                 INIT_LIST_HEAD(&cl->un.leaf.drop_list);
1236                         }
1237                         cl->prio_activity = 0;
1238                         cl->cmode = HTB_CAN_SEND;
1239 #ifdef HTB_DEBUG
1240                         cl->pq_node.rb_color = -1;
1241                         memset(cl->node,255,sizeof(cl->node));
1242 #endif
1243
1244                 }
1245         }
1246         sch->flags &= ~TCQ_F_THROTTLED;
1247         del_timer(&q->timer);
1248         __skb_queue_purge(&q->direct_queue);
1249         sch->q.qlen = 0;
1250         memset(q->row,0,sizeof(q->row));
1251         memset(q->row_mask,0,sizeof(q->row_mask));
1252         memset(q->wait_pq,0,sizeof(q->wait_pq));
1253         memset(q->ptr,0,sizeof(q->ptr));
1254         for (i = 0; i < TC_HTB_NUMPRIO; i++)
1255                 INIT_LIST_HEAD(q->drops+i);
1256 }
1257
1258 static int htb_init(struct Qdisc *sch, struct rtattr *opt)
1259 {
1260         struct htb_sched *q = qdisc_priv(sch);
1261         struct rtattr *tb[TCA_HTB_INIT];
1262         struct tc_htb_glob *gopt;
1263         int i;
1264 #ifdef HTB_DEBUG
1265         printk(KERN_INFO "HTB init, kernel part version %d.%d\n",
1266                           HTB_VER >> 16,HTB_VER & 0xffff);
1267 #endif
1268         if (!opt || rtattr_parse(tb, TCA_HTB_INIT, RTA_DATA(opt), RTA_PAYLOAD(opt)) ||
1269                         tb[TCA_HTB_INIT-1] == NULL ||
1270                         RTA_PAYLOAD(tb[TCA_HTB_INIT-1]) < sizeof(*gopt)) {
1271                 printk(KERN_ERR "HTB: hey probably you have bad tc tool ?\n");
1272                 return -EINVAL;
1273         }
1274         gopt = RTA_DATA(tb[TCA_HTB_INIT-1]);
1275         if (gopt->version != HTB_VER >> 16) {
1276                 printk(KERN_ERR "HTB: need tc/htb version %d (minor is %d), you have %d\n",
1277                                 HTB_VER >> 16,HTB_VER & 0xffff,gopt->version);
1278                 return -EINVAL;
1279         }
1280         q->debug = gopt->debug;
1281         HTB_DBG(0,1,"htb_init sch=%p handle=%X r2q=%d\n",sch,sch->handle,gopt->rate2quantum);
1282
1283         INIT_LIST_HEAD(&q->root);
1284         for (i = 0; i < HTB_HSIZE; i++)
1285                 INIT_LIST_HEAD(q->hash+i);
1286         for (i = 0; i < TC_HTB_NUMPRIO; i++)
1287                 INIT_LIST_HEAD(q->drops+i);
1288
1289         init_timer(&q->timer);
1290         skb_queue_head_init(&q->direct_queue);
1291
1292         q->direct_qlen = sch->dev->tx_queue_len;
1293         if (q->direct_qlen < 2) /* some devices have zero tx_queue_len */
1294                 q->direct_qlen = 2;
1295         q->timer.function = htb_timer;
1296         q->timer.data = (unsigned long)sch;
1297
1298 #ifdef HTB_RATECM
1299         init_timer(&q->rttim);
1300         q->rttim.function = htb_rate_timer;
1301         q->rttim.data = (unsigned long)sch;
1302         q->rttim.expires = jiffies + HZ;
1303         add_timer(&q->rttim);
1304 #endif
1305         if ((q->rate2quantum = gopt->rate2quantum) < 1)
1306                 q->rate2quantum = 1;
1307         q->defcls = gopt->defcls;
1308
1309         return 0;
1310 }
1311
1312 static int htb_dump(struct Qdisc *sch, struct sk_buff *skb)
1313 {
1314         struct htb_sched *q = qdisc_priv(sch);
1315         unsigned char    *b = skb->tail;
1316         struct rtattr *rta;
1317         struct tc_htb_glob gopt;
1318         HTB_DBG(0,1,"htb_dump sch=%p, handle=%X\n",sch,sch->handle);
1319         /* stats */
1320         HTB_QLOCK(sch);
1321         gopt.direct_pkts = q->direct_pkts;
1322
1323 #ifdef HTB_DEBUG
1324         if (HTB_DBG_COND(0,2))
1325                 htb_debug_dump(q);
1326 #endif
1327         gopt.version = HTB_VER;
1328         gopt.rate2quantum = q->rate2quantum;
1329         gopt.defcls = q->defcls;
1330         gopt.debug = q->debug;
1331         rta = (struct rtattr*)b;
1332         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
1333         RTA_PUT(skb, TCA_HTB_INIT, sizeof(gopt), &gopt);
1334         rta->rta_len = skb->tail - b;
1335         sch->stats.qlen = sch->q.qlen;
1336         RTA_PUT(skb, TCA_STATS, sizeof(sch->stats), &sch->stats);
1337         HTB_QUNLOCK(sch);
1338         return skb->len;
1339 rtattr_failure:
1340         HTB_QUNLOCK(sch);
1341         skb_trim(skb, skb->tail - skb->data);
1342         return -1;
1343 }
1344
1345 static int htb_dump_class(struct Qdisc *sch, unsigned long arg,
1346         struct sk_buff *skb, struct tcmsg *tcm)
1347 {
1348 #ifdef HTB_DEBUG
1349         struct htb_sched *q = qdisc_priv(sch);
1350 #endif
1351         struct htb_class *cl = (struct htb_class*)arg;
1352         unsigned char    *b = skb->tail;
1353         struct rtattr *rta;
1354         struct tc_htb_opt opt;
1355
1356         HTB_DBG(0,1,"htb_dump_class handle=%X clid=%X\n",sch->handle,cl->classid);
1357
1358         HTB_QLOCK(sch);
1359         tcm->tcm_parent = cl->parent ? cl->parent->classid : TC_H_ROOT;
1360         tcm->tcm_handle = cl->classid;
1361         if (!cl->level && cl->un.leaf.q) {
1362                 tcm->tcm_info = cl->un.leaf.q->handle;
1363                 cl->stats.qlen = cl->un.leaf.q->q.qlen;
1364         }
1365
1366         rta = (struct rtattr*)b;
1367         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
1368
1369         memset (&opt,0,sizeof(opt));
1370
1371         opt.rate = cl->rate->rate; opt.buffer = cl->buffer;
1372         opt.ceil = cl->ceil->rate; opt.cbuffer = cl->cbuffer;
1373         opt.quantum = cl->un.leaf.quantum; opt.prio = cl->un.leaf.prio;
1374         opt.level = cl->level;
1375         RTA_PUT(skb, TCA_HTB_PARMS, sizeof(opt), &opt);
1376         rta->rta_len = skb->tail - b;
1377
1378 #ifdef HTB_RATECM
1379         cl->stats.bps = cl->rate_bytes/(HTB_EWMAC*HTB_HSIZE);
1380         cl->stats.pps = cl->rate_packets/(HTB_EWMAC*HTB_HSIZE);
1381 #endif
1382
1383         cl->xstats.tokens = cl->tokens;
1384         cl->xstats.ctokens = cl->ctokens;
1385         RTA_PUT(skb, TCA_STATS, sizeof(cl->stats), &cl->stats);
1386         RTA_PUT(skb, TCA_XSTATS, sizeof(cl->xstats), &cl->xstats);
1387         HTB_QUNLOCK(sch);
1388         return skb->len;
1389 rtattr_failure:
1390         HTB_QUNLOCK(sch);
1391         skb_trim(skb, b - skb->data);
1392         return -1;
1393 }
1394
1395 static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1396         struct Qdisc **old)
1397 {
1398         struct htb_class *cl = (struct htb_class*)arg;
1399
1400         if (cl && !cl->level) {
1401                 if (new == NULL && (new = qdisc_create_dflt(sch->dev,
1402                                         &pfifo_qdisc_ops)) == NULL)
1403                                         return -ENOBUFS;
1404                 sch_tree_lock(sch);
1405                 if ((*old = xchg(&cl->un.leaf.q, new)) != NULL) {
1406                         if (cl->prio_activity)
1407                                 htb_deactivate (qdisc_priv(sch),cl);
1408
1409                         /* TODO: is it correct ? Why CBQ doesn't do it ? */
1410                         sch->q.qlen -= (*old)->q.qlen;
1411                         qdisc_reset(*old);
1412                 }
1413                 sch_tree_unlock(sch);
1414                 return 0;
1415         }
1416         return -ENOENT;
1417 }
1418
1419 static struct Qdisc * htb_leaf(struct Qdisc *sch, unsigned long arg)
1420 {
1421         struct htb_class *cl = (struct htb_class*)arg;
1422         return (cl && !cl->level) ? cl->un.leaf.q : NULL;
1423 }
1424
1425 static unsigned long htb_get(struct Qdisc *sch, u32 classid)
1426 {
1427 #ifdef HTB_DEBUG
1428         struct htb_sched *q = qdisc_priv(sch);
1429 #endif
1430         struct htb_class *cl = htb_find(classid,sch);
1431         HTB_DBG(0,1,"htb_get clid=%X q=%p cl=%p ref=%d\n",classid,q,cl,cl?cl->refcnt:0);
1432         if (cl)
1433                 cl->refcnt++;
1434         return (unsigned long)cl;
1435 }
1436
1437 static void htb_destroy_filters(struct tcf_proto **fl)
1438 {
1439         struct tcf_proto *tp;
1440
1441         while ((tp = *fl) != NULL) {
1442                 *fl = tp->next;
1443                 tcf_destroy(tp);
1444         }
1445 }
1446
1447 static void htb_destroy_class(struct Qdisc* sch,struct htb_class *cl)
1448 {
1449         struct htb_sched *q = qdisc_priv(sch);
1450         HTB_DBG(0,1,"htb_destrycls clid=%X ref=%d\n", cl?cl->classid:0,cl?cl->refcnt:0);
1451         if (!cl->level) {
1452                 BUG_TRAP(cl->un.leaf.q);
1453                 sch->q.qlen -= cl->un.leaf.q->q.qlen;
1454                 qdisc_destroy(cl->un.leaf.q);
1455         }
1456         qdisc_put_rtab(cl->rate);
1457         qdisc_put_rtab(cl->ceil);
1458
1459 #ifdef CONFIG_NET_ESTIMATOR
1460         qdisc_kill_estimator(&cl->stats);
1461 #endif
1462         htb_destroy_filters (&cl->filter_list);
1463
1464         while (!list_empty(&cl->children))
1465                 htb_destroy_class (sch,list_entry(cl->children.next,
1466                                         struct htb_class,sibling));
1467
1468         /* note: this delete may happen twice (see htb_delete) */
1469         list_del(&cl->hlist);
1470         list_del(&cl->sibling);
1471
1472         if (cl->prio_activity)
1473                 htb_deactivate (q,cl);
1474
1475         if (cl->cmode != HTB_CAN_SEND)
1476                 htb_safe_rb_erase(&cl->pq_node,q->wait_pq+cl->level);
1477
1478         kfree(cl);
1479 }
1480
1481 /* always caled under BH & queue lock */
1482 static void htb_destroy(struct Qdisc* sch)
1483 {
1484         struct htb_sched *q = qdisc_priv(sch);
1485         HTB_DBG(0,1,"htb_destroy q=%p\n",q);
1486
1487         del_timer_sync (&q->timer);
1488 #ifdef HTB_RATECM
1489         del_timer_sync (&q->rttim);
1490 #endif
1491         /* This line used to be after htb_destroy_class call below
1492            and surprisingly it worked in 2.4. But it must precede it
1493            because filter need its target class alive to be able to call
1494            unbind_filter on it (without Oops). */
1495         htb_destroy_filters(&q->filter_list);
1496
1497         while (!list_empty(&q->root))
1498                 htb_destroy_class (sch,list_entry(q->root.next,
1499                                         struct htb_class,sibling));
1500
1501         __skb_queue_purge(&q->direct_queue);
1502 }
1503
1504 static int htb_delete(struct Qdisc *sch, unsigned long arg)
1505 {
1506         struct htb_sched *q = qdisc_priv(sch);
1507         struct htb_class *cl = (struct htb_class*)arg;
1508         HTB_DBG(0,1,"htb_delete q=%p cl=%X ref=%d\n",q,cl?cl->classid:0,cl?cl->refcnt:0);
1509
1510         // TODO: why don't allow to delete subtree ? references ? does
1511         // tc subsys quarantee us that in htb_destroy it holds no class
1512         // refs so that we can remove children safely there ?
1513         if (!list_empty(&cl->children) || cl->filter_cnt)
1514                 return -EBUSY;
1515
1516         sch_tree_lock(sch);
1517
1518         /* delete from hash and active; remainder in destroy_class */
1519         list_del_init(&cl->hlist);
1520         if (cl->prio_activity)
1521                 htb_deactivate (q,cl);
1522
1523         if (--cl->refcnt == 0)
1524                 htb_destroy_class(sch,cl);
1525
1526         sch_tree_unlock(sch);
1527         return 0;
1528 }
1529
1530 static void htb_put(struct Qdisc *sch, unsigned long arg)
1531 {
1532 #ifdef HTB_DEBUG
1533         struct htb_sched *q = qdisc_priv(sch);
1534 #endif
1535         struct htb_class *cl = (struct htb_class*)arg;
1536         HTB_DBG(0,1,"htb_put q=%p cl=%X ref=%d\n",q,cl?cl->classid:0,cl?cl->refcnt:0);
1537
1538         if (--cl->refcnt == 0)
1539                 htb_destroy_class(sch,cl);
1540 }
1541
1542 static int htb_change_class(struct Qdisc *sch, u32 classid,
1543                 u32 parentid, struct rtattr **tca, unsigned long *arg)
1544 {
1545         int err = -EINVAL;
1546         struct htb_sched *q = qdisc_priv(sch);
1547         struct htb_class *cl = (struct htb_class*)*arg,*parent;
1548         struct rtattr *opt = tca[TCA_OPTIONS-1];
1549         struct qdisc_rate_table *rtab = NULL, *ctab = NULL;
1550         struct rtattr *tb[TCA_HTB_RTAB];
1551         struct tc_htb_opt *hopt;
1552
1553         /* extract all subattrs from opt attr */
1554         if (!opt || rtattr_parse(tb, TCA_HTB_RTAB, RTA_DATA(opt), RTA_PAYLOAD(opt)) ||
1555                         tb[TCA_HTB_PARMS-1] == NULL ||
1556                         RTA_PAYLOAD(tb[TCA_HTB_PARMS-1]) < sizeof(*hopt))
1557                 goto failure;
1558
1559         parent = parentid == TC_H_ROOT ? NULL : htb_find (parentid,sch);
1560
1561         hopt = RTA_DATA(tb[TCA_HTB_PARMS-1]);
1562         HTB_DBG(0,1,"htb_chg cl=%p(%X), clid=%X, parid=%X, opt/prio=%d, rate=%u, buff=%d, quant=%d\n", cl,cl?cl->classid:0,classid,parentid,(int)hopt->prio,hopt->rate.rate,hopt->buffer,hopt->quantum);
1563         rtab = qdisc_get_rtab(&hopt->rate, tb[TCA_HTB_RTAB-1]);
1564         ctab = qdisc_get_rtab(&hopt->ceil, tb[TCA_HTB_CTAB-1]);
1565         if (!rtab || !ctab) goto failure;
1566
1567         if (!cl) { /* new class */
1568                 struct Qdisc *new_q;
1569                 /* check for valid classid */
1570                 if (!classid || TC_H_MAJ(classid^sch->handle) || htb_find(classid,sch))
1571                         goto failure;
1572
1573                 /* check maximal depth */
1574                 if (parent && parent->parent && parent->parent->level < 2) {
1575                         printk(KERN_ERR "htb: tree is too deep\n");
1576                         goto failure;
1577                 }
1578                 err = -ENOBUFS;
1579                 if ((cl = kmalloc(sizeof(*cl), GFP_KERNEL)) == NULL)
1580                         goto failure;
1581
1582                 memset(cl, 0, sizeof(*cl));
1583                 cl->refcnt = 1;
1584                 INIT_LIST_HEAD(&cl->sibling);
1585                 INIT_LIST_HEAD(&cl->hlist);
1586                 INIT_LIST_HEAD(&cl->children);
1587                 INIT_LIST_HEAD(&cl->un.leaf.drop_list);
1588 #ifdef HTB_DEBUG
1589                 cl->magic = HTB_CMAGIC;
1590 #endif
1591
1592                 /* create leaf qdisc early because it uses kmalloc(GFP_KERNEL)
1593                    so that can't be used inside of sch_tree_lock
1594                    -- thanks to Karlis Peisenieks */
1595                 new_q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
1596                 sch_tree_lock(sch);
1597                 if (parent && !parent->level) {
1598                         /* turn parent into inner node */
1599                         sch->q.qlen -= parent->un.leaf.q->q.qlen;
1600                         qdisc_destroy (parent->un.leaf.q);
1601                         if (parent->prio_activity)
1602                                 htb_deactivate (q,parent);
1603
1604                         /* remove from evt list because of level change */
1605                         if (parent->cmode != HTB_CAN_SEND) {
1606                                 htb_safe_rb_erase(&parent->pq_node,q->wait_pq /*+0*/);
1607                                 parent->cmode = HTB_CAN_SEND;
1608                         }
1609                         parent->level = (parent->parent ? parent->parent->level
1610                                         : TC_HTB_MAXDEPTH) - 1;
1611                         memset (&parent->un.inner,0,sizeof(parent->un.inner));
1612                 }
1613                 /* leaf (we) needs elementary qdisc */
1614                 cl->un.leaf.q = new_q ? new_q : &noop_qdisc;
1615
1616                 cl->classid = classid; cl->parent = parent;
1617
1618                 /* set class to be in HTB_CAN_SEND state */
1619                 cl->tokens = hopt->buffer;
1620                 cl->ctokens = hopt->cbuffer;
1621                 cl->mbuffer = 60000000; /* 1min */
1622                 PSCHED_GET_TIME(cl->t_c);
1623                 cl->cmode = HTB_CAN_SEND;
1624
1625                 /* attach to the hash list and parent's family */
1626                 list_add_tail(&cl->hlist, q->hash+htb_hash(classid));
1627                 list_add_tail(&cl->sibling, parent ? &parent->children : &q->root);
1628 #ifdef HTB_DEBUG
1629                 {
1630                         int i;
1631                         for (i = 0; i < TC_HTB_NUMPRIO; i++) cl->node[i].rb_color = -1;
1632                         cl->pq_node.rb_color = -1;
1633                 }
1634 #endif
1635         } else sch_tree_lock(sch);
1636
1637         /* it used to be a nasty bug here, we have to check that node
1638            is really leaf before changing cl->un.leaf ! */
1639         if (!cl->level) {
1640                 cl->un.leaf.quantum = rtab->rate.rate / q->rate2quantum;
1641                 if (!hopt->quantum && cl->un.leaf.quantum < 1000) {
1642                         printk(KERN_WARNING "HTB: quantum of class %X is small. Consider r2q change.\n", cl->classid);
1643                         cl->un.leaf.quantum = 1000;
1644                 }
1645                 if (!hopt->quantum && cl->un.leaf.quantum > 200000) {
1646                         printk(KERN_WARNING "HTB: quantum of class %X is big. Consider r2q change.\n", cl->classid);
1647                         cl->un.leaf.quantum = 200000;
1648                 }
1649                 if (hopt->quantum)
1650                         cl->un.leaf.quantum = hopt->quantum;
1651                 if ((cl->un.leaf.prio = hopt->prio) >= TC_HTB_NUMPRIO)
1652                         cl->un.leaf.prio = TC_HTB_NUMPRIO - 1;
1653         }
1654
1655         cl->buffer = hopt->buffer;
1656         cl->cbuffer = hopt->cbuffer;
1657         if (cl->rate) qdisc_put_rtab(cl->rate); cl->rate = rtab;
1658         if (cl->ceil) qdisc_put_rtab(cl->ceil); cl->ceil = ctab;
1659         sch_tree_unlock(sch);
1660
1661         *arg = (unsigned long)cl;
1662         return 0;
1663
1664 failure:
1665         if (rtab) qdisc_put_rtab(rtab);
1666         if (ctab) qdisc_put_rtab(ctab);
1667         return err;
1668 }
1669
1670 static struct tcf_proto **htb_find_tcf(struct Qdisc *sch, unsigned long arg)
1671 {
1672         struct htb_sched *q = qdisc_priv(sch);
1673         struct htb_class *cl = (struct htb_class *)arg;
1674         struct tcf_proto **fl = cl ? &cl->filter_list : &q->filter_list;
1675         HTB_DBG(0,2,"htb_tcf q=%p clid=%X fref=%d fl=%p\n",q,cl?cl->classid:0,cl?cl->filter_cnt:q->filter_cnt,*fl);
1676         return fl;
1677 }
1678
1679 static unsigned long htb_bind_filter(struct Qdisc *sch, unsigned long parent,
1680         u32 classid)
1681 {
1682         struct htb_sched *q = qdisc_priv(sch);
1683         struct htb_class *cl = htb_find (classid,sch);
1684         HTB_DBG(0,2,"htb_bind q=%p clid=%X cl=%p fref=%d\n",q,classid,cl,cl?cl->filter_cnt:q->filter_cnt);
1685         /*if (cl && !cl->level) return 0;
1686           The line above used to be there to prevent attaching filters to
1687           leaves. But at least tc_index filter uses this just to get class
1688           for other reasons so that we have to allow for it.
1689           ----
1690           19.6.2002 As Werner explained it is ok - bind filter is just
1691           another way to "lock" the class - unlike "get" this lock can
1692           be broken by class during destroy IIUC.
1693          */
1694         if (cl)
1695                 cl->filter_cnt++;
1696         else
1697                 q->filter_cnt++;
1698         return (unsigned long)cl;
1699 }
1700
1701 static void htb_unbind_filter(struct Qdisc *sch, unsigned long arg)
1702 {
1703         struct htb_sched *q = qdisc_priv(sch);
1704         struct htb_class *cl = (struct htb_class *)arg;
1705         HTB_DBG(0,2,"htb_unbind q=%p cl=%p fref=%d\n",q,cl,cl?cl->filter_cnt:q->filter_cnt);
1706         if (cl)
1707                 cl->filter_cnt--;
1708         else
1709                 q->filter_cnt--;
1710 }
1711
1712 static void htb_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1713 {
1714         struct htb_sched *q = qdisc_priv(sch);
1715         int i;
1716
1717         if (arg->stop)
1718                 return;
1719
1720         for (i = 0; i < HTB_HSIZE; i++) {
1721                 struct list_head *p;
1722                 list_for_each (p,q->hash+i) {
1723                         struct htb_class *cl = list_entry(p,struct htb_class,hlist);
1724                         if (arg->count < arg->skip) {
1725                                 arg->count++;
1726                                 continue;
1727                         }
1728                         if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
1729                                 arg->stop = 1;
1730                                 return;
1731                         }
1732                         arg->count++;
1733                 }
1734         }
1735 }
1736
1737 static struct Qdisc_class_ops htb_class_ops = {
1738         .graft          =       htb_graft,
1739         .leaf           =       htb_leaf,
1740         .get            =       htb_get,
1741         .put            =       htb_put,
1742         .change         =       htb_change_class,
1743         .delete         =       htb_delete,
1744         .walk           =       htb_walk,
1745         .tcf_chain      =       htb_find_tcf,
1746         .bind_tcf       =       htb_bind_filter,
1747         .unbind_tcf     =       htb_unbind_filter,
1748         .dump           =       htb_dump_class,
1749 };
1750
1751 static struct Qdisc_ops htb_qdisc_ops = {
1752         .next           =       NULL,
1753         .cl_ops         =       &htb_class_ops,
1754         .id             =       "htb",
1755         .priv_size      =       sizeof(struct htb_sched),
1756         .enqueue        =       htb_enqueue,
1757         .dequeue        =       htb_dequeue,
1758         .requeue        =       htb_requeue,
1759         .drop           =       htb_drop,
1760         .init           =       htb_init,
1761         .reset          =       htb_reset,
1762         .destroy        =       htb_destroy,
1763         .change         =       NULL /* htb_change */,
1764         .dump           =       htb_dump,
1765         .owner          =       THIS_MODULE,
1766 };
1767
1768 static int __init htb_module_init(void)
1769 {
1770     return register_qdisc(&htb_qdisc_ops);
1771 }
1772 static void __exit htb_module_exit(void)
1773 {
1774     unregister_qdisc(&htb_qdisc_ops);
1775 }
1776 module_init(htb_module_init)
1777 module_exit(htb_module_exit)
1778 MODULE_LICENSE("GPL");