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Diffstat (limited to 'net/sched/sch_htb.c')
| -rw-r--r-- | net/sched/sch_htb.c | 1590 |
1 files changed, 1590 insertions, 0 deletions
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c new file mode 100644 index 0000000..d2943a4 --- /dev/null +++ b/net/sched/sch_htb.c @@ -0,0 +1,1590 @@ +/* + * net/sched/sch_htb.c Hierarchical token bucket, feed tree version + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Authors: Martin Devera, <devik@cdi.cz> + * + * Credits (in time order) for older HTB versions: + * Stef Coene <stef.coene@docum.org> + * HTB support at LARTC mailing list + * Ondrej Kraus, <krauso@barr.cz> + * found missing INIT_QDISC(htb) + * Vladimir Smelhaus, Aamer Akhter, Bert Hubert + * helped a lot to locate nasty class stall bug + * Andi Kleen, Jamal Hadi, Bert Hubert + * code review and helpful comments on shaping + * Tomasz Wrona, <tw@eter.tym.pl> + * created test case so that I was able to fix nasty bug + * Wilfried Weissmann + * spotted bug in dequeue code and helped with fix + * Jiri Fojtasek + * fixed requeue routine + * and many others. thanks. + */ +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/skbuff.h> +#include <linux/list.h> +#include <linux/compiler.h> +#include <linux/rbtree.h> +#include <net/netlink.h> +#include <net/pkt_sched.h> + +/* HTB algorithm. + Author: devik@cdi.cz + ======================================================================== + HTB is like TBF with multiple classes. It is also similar to CBQ because + it allows to assign priority to each class in hierarchy. + In fact it is another implementation of Floyd's formal sharing. + + Levels: + Each class is assigned level. Leaf has ALWAYS level 0 and root + classes have level TC_HTB_MAXDEPTH-1. Interior nodes has level + one less than their parent. +*/ + +static int htb_hysteresis __read_mostly = 0; /* whether to use mode hysteresis for speedup */ +#define HTB_VER 0x30011 /* major must be matched with number suplied by TC as version */ + +#if HTB_VER >> 16 != TC_HTB_PROTOVER +#error "Mismatched sch_htb.c and pkt_sch.h" +#endif + +/* Module parameter and sysfs export */ +module_param (htb_hysteresis, int, 0640); +MODULE_PARM_DESC(htb_hysteresis, "Hysteresis mode, less CPU load, less accurate"); + +/* used internaly to keep status of single class */ +enum htb_cmode { + HTB_CANT_SEND, /* class can't send and can't borrow */ + HTB_MAY_BORROW, /* class can't send but may borrow */ + HTB_CAN_SEND /* class can send */ +}; + +/* interior & leaf nodes; props specific to leaves are marked L: */ +struct htb_class { + struct Qdisc_class_common common; + /* general class parameters */ + struct gnet_stats_basic bstats; + struct gnet_stats_queue qstats; + struct gnet_stats_rate_est rate_est; + struct tc_htb_xstats xstats; /* our special stats */ + int refcnt; /* usage count of this class */ + + /* topology */ + int level; /* our level (see above) */ + unsigned int children; + struct htb_class *parent; /* parent class */ + + union { + struct htb_class_leaf { + struct Qdisc *q; + int prio; + int aprio; + int quantum; + int deficit[TC_HTB_MAXDEPTH]; + struct list_head drop_list; + } leaf; + struct htb_class_inner { + struct rb_root feed[TC_HTB_NUMPRIO]; /* feed trees */ + struct rb_node *ptr[TC_HTB_NUMPRIO]; /* current class ptr */ + /* When class changes from state 1->2 and disconnects from + parent's feed then we lost ptr value and start from the + first child again. Here we store classid of the + last valid ptr (used when ptr is NULL). */ + u32 last_ptr_id[TC_HTB_NUMPRIO]; + } inner; + } un; + struct rb_node node[TC_HTB_NUMPRIO]; /* node for self or feed tree */ + struct rb_node pq_node; /* node for event queue */ + psched_time_t pq_key; + + int prio_activity; /* for which prios are we active */ + enum htb_cmode cmode; /* current mode of the class */ + + /* class attached filters */ + struct tcf_proto *filter_list; + int filter_cnt; + + int warned; /* only one warning about non work conserving .. */ + + /* token bucket parameters */ + struct qdisc_rate_table *rate; /* rate table of the class itself */ + struct qdisc_rate_table *ceil; /* ceiling rate (limits borrows too) */ + long buffer, cbuffer; /* token bucket depth/rate */ + psched_tdiff_t mbuffer; /* max wait time */ + long tokens, ctokens; /* current number of tokens */ + psched_time_t t_c; /* checkpoint time */ + + int prio; /* For parent to leaf return possible here */ + int quantum; /* we do backup. Finally full replacement */ + /* of un.leaf originals should be done. */ +}; + +static inline long L2T(struct htb_class *cl, struct qdisc_rate_table *rate, + int size) +{ + long result = qdisc_l2t(rate, size); + return result; +} + +struct htb_sched { + struct Qdisc_class_hash clhash; + struct list_head drops[TC_HTB_NUMPRIO];/* active leaves (for drops) */ + + /* self list - roots of self generating tree */ + struct rb_root row[TC_HTB_MAXDEPTH][TC_HTB_NUMPRIO]; + int row_mask[TC_HTB_MAXDEPTH]; + struct rb_node *ptr[TC_HTB_MAXDEPTH][TC_HTB_NUMPRIO]; + u32 last_ptr_id[TC_HTB_MAXDEPTH][TC_HTB_NUMPRIO]; + + /* self wait list - roots of wait PQs per row */ + struct rb_root wait_pq[TC_HTB_MAXDEPTH]; + + /* time of nearest event per level (row) */ + psched_time_t near_ev_cache[TC_HTB_MAXDEPTH]; + + /* whether we hit non-work conserving class during this dequeue; we use */ + int nwc_hit; /* this to disable mindelay complaint in dequeue */ + + int defcls; /* class where unclassified flows go to */ + + /* filters for qdisc itself */ + struct tcf_proto *filter_list; + + int rate2quantum; /* quant = rate / rate2quantum */ + psched_time_t now; /* cached dequeue time */ + struct qdisc_watchdog watchdog; + + /* non shaped skbs; let them go directly thru */ + struct sk_buff_head direct_queue; + int direct_qlen; /* max qlen of above */ + + long direct_pkts; +}; + +/* find class in global hash table using given handle */ +static inline struct htb_class *htb_find(u32 handle, struct Qdisc *sch) +{ + struct htb_sched *q = qdisc_priv(sch); + struct Qdisc_class_common *clc; + + clc = qdisc_class_find(&q->clhash, handle); + if (clc == NULL) + return NULL; + return container_of(clc, struct htb_class, common); +} + +/** + * htb_classify - classify a packet into class + * + * It returns NULL if the packet should be dropped or -1 if the packet + * should be passed directly thru. In all other cases leaf class is returned. + * We allow direct class selection by classid in priority. The we examine + * filters in qdisc and in inner nodes (if higher filter points to the inner + * node). If we end up with classid MAJOR:0 we enqueue the skb into special + * internal fifo (direct). These packets then go directly thru. If we still + * have no valid leaf we try to use MAJOR:default leaf. It still unsuccessfull + * then finish and return direct queue. + */ +#define HTB_DIRECT (struct htb_class*)-1 + +static struct htb_class *htb_classify(struct sk_buff *skb, struct Qdisc *sch, + int *qerr) +{ + struct htb_sched *q = qdisc_priv(sch); + struct htb_class *cl; + struct tcf_result res; + struct tcf_proto *tcf; + int result; + + /* allow to select class by setting skb->priority to valid classid; + note that nfmark can be used too by attaching filter fw with no + rules in it */ + if (skb->priority == sch->handle) + return HTB_DIRECT; /* X:0 (direct flow) selected */ + if ((cl = htb_find(skb->priority, sch)) != NULL && cl->level == 0) + return cl; + + *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; + tcf = q->filter_list; + while (tcf && (result = tc_classify(skb, tcf, &res)) >= 0) { +#ifdef CONFIG_NET_CLS_ACT + switch (result) { + case TC_ACT_QUEUED: + case TC_ACT_STOLEN: + *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; + case TC_ACT_SHOT: + return NULL; + } +#endif + if ((cl = (void *)res.class) == NULL) { + if (res.classid == sch->handle) + return HTB_DIRECT; /* X:0 (direct flow) */ + if ((cl = htb_find(res.classid, sch)) == NULL) + break; /* filter selected invalid classid */ + } + if (!cl->level) + return cl; /* we hit leaf; return it */ + + /* we have got inner class; apply inner filter chain */ + tcf = cl->filter_list; + } + /* classification failed; try to use default class */ + cl = htb_find(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch); + if (!cl || cl->level) + return HTB_DIRECT; /* bad default .. this is safe bet */ + return cl; +} + +/** + * htb_add_to_id_tree - adds class to the round robin list + * + * Routine adds class to the list (actually tree) sorted by classid. + * Make sure that class is not already on such list for given prio. + */ +static void htb_add_to_id_tree(struct rb_root *root, + struct htb_class *cl, int prio) +{ + struct rb_node **p = &root->rb_node, *parent = NULL; + + while (*p) { + struct htb_class *c; + parent = *p; + c = rb_entry(parent, struct htb_class, node[prio]); + + if (cl->common.classid > c->common.classid) + p = &parent->rb_right; + else + p = &parent->rb_left; + } + rb_link_node(&cl->node[prio], parent, p); + rb_insert_color(&cl->node[prio], root); +} + +/** + * htb_add_to_wait_tree - adds class to the event queue with delay + * + * The class is added to priority event queue to indicate that class will + * change its mode in cl->pq_key microseconds. Make sure that class is not + * already in the queue. + */ +static void htb_add_to_wait_tree(struct htb_sched *q, + struct htb_class *cl, long delay) +{ + struct rb_node **p = &q->wait_pq[cl->level].rb_node, *parent = NULL; + + cl->pq_key = q->now + delay; + if (cl->pq_key == q->now) + cl->pq_key++; + + /* update the nearest event cache */ + if (q->near_ev_cache[cl->level] > cl->pq_key) + q->near_ev_cache[cl->level] = cl->pq_key; + + while (*p) { + struct htb_class *c; + parent = *p; + c = rb_entry(parent, struct htb_class, pq_node); + if (cl->pq_key >= c->pq_key) + p = &parent->rb_right; + else + p = &parent->rb_left; + } + rb_link_node(&cl->pq_node, parent, p); + rb_insert_color(&cl->pq_node, &q->wait_pq[cl->level]); +} + +/** + * htb_next_rb_node - finds next node in binary tree + * + * When we are past last key we return NULL. + * Average complexity is 2 steps per call. + */ +static inline void htb_next_rb_node(struct rb_node **n) +{ + *n = rb_next(*n); +} + +/** + * htb_add_class_to_row - add class to its row + * + * The class is added to row at priorities marked in mask. + * It does nothing if mask == 0. + */ +static inline void htb_add_class_to_row(struct htb_sched *q, + struct htb_class *cl, int mask) +{ + q->row_mask[cl->level] |= mask; + while (mask) { + int prio = ffz(~mask); + mask &= ~(1 << prio); + htb_add_to_id_tree(q->row[cl->level] + prio, cl, prio); + } +} + +/* If this triggers, it is a bug in this code, but it need not be fatal */ +static void htb_safe_rb_erase(struct rb_node *rb, struct rb_root *root) +{ + if (RB_EMPTY_NODE(rb)) { + WARN_ON(1); + } else { + rb_erase(rb, root); + RB_CLEAR_NODE(rb); + } +} + + +/** + * htb_remove_class_from_row - removes class from its row + * + * The class is removed from row at priorities marked in mask. + * It does nothing if mask == 0. + */ +static inline void htb_remove_class_from_row(struct htb_sched *q, + struct htb_class *cl, int mask) +{ + int m = 0; + + while (mask) { + int prio = ffz(~mask); + + mask &= ~(1 << prio); + if (q->ptr[cl->level][prio] == cl->node + prio) + htb_next_rb_node(q->ptr[cl->level] + prio); + + htb_safe_rb_erase(cl->node + prio, q->row[cl->level] + prio); + if (!q->row[cl->level][prio].rb_node) + m |= 1 << prio; + } + q->row_mask[cl->level] &= ~m; +} + +/** + * htb_activate_prios - creates active classe's feed chain + * + * The class is connected to ancestors and/or appropriate rows + * for priorities it is participating on. cl->cmode must be new + * (activated) mode. It does nothing if cl->prio_activity == 0. + */ +static void htb_activate_prios(struct htb_sched *q, struct htb_class *cl) +{ + struct htb_class *p = cl->parent; + long m, mask = cl->prio_activity; + + while (cl->cmode == HTB_MAY_BORROW && p && mask) { + m = mask; + while (m) { + int prio = ffz(~m); + m &= ~(1 << prio); + + if (p->un.inner.feed[prio].rb_node) + /* parent already has its feed in use so that + reset bit in mask as parent is already ok */ + mask &= ~(1 << prio); + + htb_add_to_id_tree(p->un.inner.feed + prio, cl, prio); + } + p->prio_activity |= mask; + cl = p; + p = cl->parent; + + } + if (cl->cmode == HTB_CAN_SEND && mask) + htb_add_class_to_row(q, cl, mask); +} + +/** + * htb_deactivate_prios - remove class from feed chain + * + * cl->cmode must represent old mode (before deactivation). It does + * nothing if cl->prio_activity == 0. Class is removed from all feed + * chains and rows. + */ +static void htb_deactivate_prios(struct htb_sched *q, struct htb_class *cl) +{ + struct htb_class *p = cl->parent; + long m, mask = cl->prio_activity; + + while (cl->cmode == HTB_MAY_BORROW && p && mask) { + m = mask; + mask = 0; + while (m) { + int prio = ffz(~m); + m &= ~(1 << prio); + + if (p->un.inner.ptr[prio] == cl->node + prio) { + /* we are removing child which is pointed to from + parent feed - forget the pointer but remember + classid */ + p->un.inner.last_ptr_id[prio] = cl->common.classid; + p->un.inner.ptr[prio] = NULL; + } + + htb_safe_rb_erase(cl->node + prio, p->un.inner.feed + prio); + + if (!p->un.inner.feed[prio].rb_node) + mask |= 1 << prio; + } + + p->prio_activity &= ~mask; + cl = p; + p = cl->parent; + + } + if (cl->cmode == HTB_CAN_SEND && mask) + htb_remove_class_from_row(q, cl, mask); +} + +static inline long htb_lowater(const struct htb_class *cl) +{ + if (htb_hysteresis) + return cl->cmode != HTB_CANT_SEND ? -cl->cbuffer : 0; + else + return 0; +} +static inline long htb_hiwater(const struct htb_class *cl) +{ + if (htb_hysteresis) + return cl->cmode == HTB_CAN_SEND ? -cl->buffer : 0; + else + return 0; +} + + +/** + * htb_class_mode - computes and returns current class mode + * + * It computes cl's mode at time cl->t_c+diff and returns it. If mode + * is not HTB_CAN_SEND then cl->pq_key is updated to time difference + * from now to time when cl will change its state. + * Also it is worth to note that class mode doesn't change simply + * at cl->{c,}tokens == 0 but there can rather be hysteresis of + * 0 .. -cl->{c,}buffer range. It is meant to limit number of + * mode transitions per time unit. The speed gain is about 1/6. + */ +static inline enum htb_cmode +htb_class_mode(struct htb_class *cl, long *diff) +{ + long toks; + + if ((toks = (cl->ctokens + *diff)) < htb_lowater(cl)) { + *diff = -toks; + return HTB_CANT_SEND; + } + + if ((toks = (cl->tokens + *diff)) >= htb_hiwater(cl)) + return HTB_CAN_SEND; + + *diff = -toks; + return HTB_MAY_BORROW; +} + +/** + * htb_change_class_mode - changes classe's mode + * + * This should be the only way how to change classe's mode under normal + * cirsumstances. Routine will update feed lists linkage, change mode + * and add class to the wait event queue if appropriate. New mode should + * be different from old one and cl->pq_key has to be valid if changing + * to mode other than HTB_CAN_SEND (see htb_add_to_wait_tree). + */ +static void +htb_change_class_mode(struct htb_sched *q, struct htb_class *cl, long *diff) +{ + enum htb_cmode new_mode = htb_class_mode(cl, diff); + + if (new_mode == cl->cmode) + return; + + if (cl->prio_activity) { /* not necessary: speed optimization */ + if (cl->cmode != HTB_CANT_SEND) + htb_deactivate_prios(q, cl); + cl->cmode = new_mode; + if (new_mode != HTB_CANT_SEND) + htb_activate_prios(q, cl); + } else + cl->cmode = new_mode; +} + +/** + * htb_activate - inserts leaf cl into appropriate active feeds + * + * Routine learns (new) priority of leaf and activates feed chain + * for the prio. It can be called on already active leaf safely. + * It also adds leaf into droplist. + */ +static inline void htb_activate(struct htb_sched *q, struct htb_class *cl) +{ + WARN_ON(cl->level || !cl->un.leaf.q || !cl->un.leaf.q->q.qlen); + + if (!cl->prio_activity) { + cl->prio_activity = 1 << (cl->un.leaf.aprio = cl->un.leaf.prio); + htb_activate_prios(q, cl); + list_add_tail(&cl->un.leaf.drop_list, + q->drops + cl->un.leaf.aprio); + } +} + +/** + * htb_deactivate - remove leaf cl from active feeds + * + * Make sure that leaf is active. In the other words it can't be called + * with non-active leaf. It also removes class from the drop list. + */ +static inline void htb_deactivate(struct htb_sched *q, struct htb_class *cl) +{ + WARN_ON(!cl->prio_activity); + + htb_deactivate_prios(q, cl); + cl->prio_activity = 0; + list_del_init(&cl->un.leaf.drop_list); +} + +static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch) +{ + int ret; + struct htb_sched *q = qdisc_priv(sch); + struct htb_class *cl = htb_classify(skb, sch, &ret); + + if (cl == HTB_DIRECT) { + /* enqueue to helper queue */ + if (q->direct_queue.qlen < q->direct_qlen) { + __skb_queue_tail(&q->direct_queue, skb); + q->direct_pkts++; + } else { + kfree_skb(skb); + sch->qstats.drops++; + return NET_XMIT_DROP; + } +#ifdef CONFIG_NET_CLS_ACT + } else if (!cl) { + if (ret & __NET_XMIT_BYPASS) + sch->qstats.drops++; + kfree_skb(skb); + return ret; +#endif + } else if ((ret = qdisc_enqueue(skb, cl->un.leaf.q)) != NET_XMIT_SUCCESS) { + if (net_xmit_drop_count(ret)) { + sch->qstats.drops++; + cl->qstats.drops++; + } + return ret; + } else { + cl->bstats.packets += + skb_is_gso(skb)?skb_shinfo(skb)->gso_segs:1; + cl->bstats.bytes += qdisc_pkt_len(skb); + htb_activate(q, cl); + } + + sch->q.qlen++; + sch->bstats.packets += skb_is_gso(skb)?skb_shinfo(skb)->gso_segs:1; + sch->bstats.bytes += qdisc_pkt_len(skb); + return NET_XMIT_SUCCESS; +} + +/* TODO: requeuing packet charges it to policers again !! */ +static int htb_requeue(struct sk_buff *skb, struct Qdisc *sch) +{ + int ret; + struct htb_sched *q = qdisc_priv(sch); + struct htb_class *cl = htb_classify(skb, sch, &ret); + struct sk_buff *tskb; + + if (cl == HTB_DIRECT) { + /* enqueue to helper queue */ + if (q->direct_queue.qlen < q->direct_qlen) { + __skb_queue_head(&q->direct_queue, skb); + } else { + __skb_queue_head(&q->direct_queue, skb); + tskb = __skb_dequeue_tail(&q->direct_queue); + kfree_skb(tskb); + sch->qstats.drops++; + return NET_XMIT_CN; + } +#ifdef CONFIG_NET_CLS_ACT + } else if (!cl) { + if (ret & __NET_XMIT_BYPASS) + sch->qstats.drops++; + kfree_skb(skb); + return ret; +#endif + } else if ((ret = cl->un.leaf.q->ops->requeue(skb, cl->un.leaf.q)) != + NET_XMIT_SUCCESS) { + if (net_xmit_drop_count(ret)) { + sch->qstats.drops++; + cl->qstats.drops++; + } + return ret; + } else + htb_activate(q, cl); + + sch->q.qlen++; + sch->qstats.requeues++; + return NET_XMIT_SUCCESS; +} + +/** + * htb_charge_class - charges amount "bytes" to leaf and ancestors + * + * Routine assumes that packet "bytes" long was dequeued from leaf cl + * borrowing from "level". It accounts bytes to ceil leaky bucket for + * leaf and all ancestors and to rate bucket for ancestors at levels + * "level" and higher. It also handles possible change of mode resulting + * from the update. Note that mode can also increase here (MAY_BORROW to + * CAN_SEND) because we can use more precise clock that event queue here. + * In such case we remove class from event queue first. + */ +static void htb_charge_class(struct htb_sched *q, struct htb_class *cl, + int level, struct sk_buff *skb) +{ + int bytes = qdisc_pkt_len(skb); + long toks, diff; + enum htb_cmode old_mode; + +#define HTB_ACCNT(T,B,R) toks = diff + cl->T; \ + if (toks > cl->B) toks = cl->B; \ + toks -= L2T(cl, cl->R, bytes); \ + if (toks <= -cl->mbuffer) toks = 1-cl->mbuffer; \ + cl->T = toks + + while (cl) { + diff = psched_tdiff_bounded(q->now, cl->t_c, cl->mbuffer); + if (cl->level >= level) { + if (cl->level == level) + cl->xstats.lends++; + HTB_ACCNT(tokens, buffer, rate); + } else { + cl->xstats.borrows++; + cl->tokens += diff; /* we moved t_c; update tokens */ + } + HTB_ACCNT(ctokens, cbuffer, ceil); + cl->t_c = q->now; + + old_mode = cl->cmode; + diff = 0; + htb_change_class_mode(q, cl, &diff); + if (old_mode != cl->cmode) { + if (old_mode != HTB_CAN_SEND) + htb_safe_rb_erase(&cl->pq_node, q->wait_pq + cl->level); + if (cl->cmode != HTB_CAN_SEND) + htb_add_to_wait_tree(q, cl, diff); + } + + /* update byte stats except for leaves which are already updated */ + if (cl->level) { + cl->bstats.bytes += bytes; + cl->bstats.packets += skb_is_gso(skb)? + skb_shinfo(skb)->gso_segs:1; + } + cl = cl->parent; + } +} + +/** + * htb_do_events - make mode changes to classes at the level + * + * Scans event queue for pending events and applies them. Returns time of + * next pending event (0 for no event in pq). + * Note: Applied are events whose have cl->pq_key <= q->now. + */ +static psched_time_t htb_do_events(struct htb_sched *q, int level) +{ + /* don't run for longer than 2 jiffies; 2 is used instead of + 1 to simplify things when jiffy is going to be incremented + too soon */ + unsigned long stop_at = jiffies + 2; + while (time_before(jiffies, stop_at)) { + struct htb_class *cl; + long diff; + struct rb_node *p = rb_first(&q->wait_pq[level]); + + if (!p) + return 0; + + cl = rb_entry(p, struct htb_class, pq_node); + if (cl->pq_key > q->now) + return cl->pq_key; + + htb_safe_rb_erase(p, q->wait_pq + level); + diff = psched_tdiff_bounded(q->now, cl->t_c, cl->mbuffer); + htb_change_class_mode(q, cl, &diff); + if (cl->cmode != HTB_CAN_SEND) + htb_add_to_wait_tree(q, cl, diff); + } + /* too much load - let's continue on next jiffie */ + return q->now + PSCHED_TICKS_PER_SEC / HZ; +} + +/* Returns class->node+prio from id-tree where classe's id is >= id. NULL + is no such one exists. */ +static struct rb_node *htb_id_find_next_upper(int prio, struct rb_node *n, + u32 id) +{ + struct rb_node *r = NULL; + while (n) { + struct htb_class *cl = + rb_entry(n, struct htb_class, node[prio]); + if (id == cl->common.classid) + return n; + + if (id > cl->common.classid) { + n = n->rb_right; + } else { + r = n; + n = n->rb_left; + } + } + return r; +} + +/** + * htb_lookup_leaf - returns next leaf class in DRR order + * + * Find leaf where current feed pointers points to. + */ +static struct htb_class *htb_lookup_leaf(struct rb_root *tree, int prio, + struct rb_node **pptr, u32 * pid) +{ + int i; + struct { + struct rb_node *root; + struct rb_node **pptr; + u32 *pid; + } stk[TC_HTB_MAXDEPTH], *sp = stk; + + WARN_ON(!tree->rb_node); + sp->root = tree->rb_node; + sp->pptr = pptr; + sp->pid = pid; + + for (i = 0; i < 65535; i++) { + if (!*sp->pptr && *sp->pid) { + /* ptr was invalidated but id is valid - try to recover + the original or next ptr */ + *sp->pptr = + htb_id_find_next_upper(prio, sp->root, *sp->pid); + } + *sp->pid = 0; /* ptr is valid now so that remove this hint as it + can become out of date quickly */ + if (!*sp->pptr) { /* we are at right end; rewind & go up */ + *sp->pptr = sp->root; + while ((*sp->pptr)->rb_left) + *sp->pptr = (*sp->pptr)->rb_left; + if (sp > stk) { + sp--; + WARN_ON(!*sp->pptr); + if (!*sp->pptr) + return NULL; + htb_next_rb_node(sp->pptr); + } + } else { + struct htb_class *cl; + cl = rb_entry(*sp->pptr, struct htb_class, node[prio]); + if (!cl->level) + return cl; + (++sp)->root = cl->un.inner.feed[prio].rb_node; + sp->pptr = cl->un.inner.ptr + prio; + sp->pid = cl->un.inner.last_ptr_id + prio; + } + } + WARN_ON(1); + return NULL; +} + +/* dequeues packet at given priority and level; call only if + you are sure that there is active class at prio/level */ +static struct sk_buff *htb_dequeue_tree(struct htb_sched *q, int prio, + int level) +{ + struct sk_buff *skb = NULL; + struct htb_class *cl, *start; + /* look initial class up in the row */ + start = cl = htb_lookup_leaf(q->row[level] + prio, prio, + q->ptr[level] + prio, + q->last_ptr_id[level] + prio); + + do { +next: + WARN_ON(!cl); + if (!cl) + return NULL; + + /* class can be empty - it is unlikely but can be true if leaf + qdisc drops packets in enqueue routine or if someone used + graft operation on the leaf since last dequeue; + simply deactivate and skip such class */ + if (unlikely(cl->un.leaf.q->q.qlen == 0)) { + struct htb_class *next; + htb_deactivate(q, cl); + + /* row/level might become empty */ + if ((q->row_mask[level] & (1 << prio)) == 0) + return NULL; + + next = htb_lookup_leaf(q->row[level] + prio, + prio, q->ptr[level] + prio, + q->last_ptr_id[level] + prio); + + if (cl == start) /* fix start if we just deleted it */ + start = next; + cl = next; + goto next; + } + + skb = cl->un.leaf.q->dequeue(cl->un.leaf.q); + if (likely(skb != NULL)) + break; + if (!cl->warned) { + printk(KERN_WARNING + "htb: class %X isn't work conserving ?!\n", + cl->common.classid); + cl->warned = 1; + } + q->nwc_hit++; + htb_next_rb_node((level ? cl->parent->un.inner.ptr : q-> + ptr[0]) + prio); + cl = htb_lookup_leaf(q->row[level] + prio, prio, + q->ptr[level] + prio, + q->last_ptr_id[level] + prio); + + } while (cl != start); + + if (likely(skb != NULL)) { + cl->un.leaf.deficit[level] -= qdisc_pkt_len(skb); + if (cl->un.leaf.deficit[level] < 0) { + cl->un.leaf.deficit[level] += cl->un.leaf.quantum; + htb_next_rb_node((level ? cl->parent->un.inner.ptr : q-> + ptr[0]) + prio); + } + /* this used to be after charge_class but this constelation + gives us slightly better performance */ + if (!cl->un.leaf.q->q.qlen) + htb_deactivate(q, cl); + htb_charge_class(q, cl, level, skb); + } + return skb; +} + +static struct sk_buff *htb_dequeue(struct Qdisc *sch) +{ + struct sk_buff *skb = NULL; + struct htb_sched *q = qdisc_priv(sch); + int level; + psched_time_t next_event; + + /* try to dequeue direct packets as high prio (!) to minimize cpu work */ + skb = __skb_dequeue(&q->direct_queue); + if (skb != NULL) { + sch->flags &= ~TCQ_F_THROTTLED; + sch->q.qlen--; + return skb; + } + + if (!sch->q.qlen) + goto fin; + q->now = psched_get_time(); + + next_event = q->now + 5 * PSCHED_TICKS_PER_SEC; + q->nwc_hit = 0; + for (level = 0; level < TC_HTB_MAXDEPTH; level++) { + /* common case optimization - skip event handler quickly */ + int m; + psched_time_t event; + + if (q->now >= q->near_ev_cache[level]) { + event = htb_do_events(q, level); + if (!event) + event = q->now + PSCHED_TICKS_PER_SEC; + q->near_ev_cache[level] = event; + } else + event = q->near_ev_cache[level]; + + if (event && next_event > event) + next_event = event; + + m = ~q->row_mask[level]; + while (m != (int)(-1)) { + int prio = ffz(m); + m |= 1 << prio; + skb = htb_dequeue_tree(q, prio, level); + if (likely(skb != NULL)) { + sch->q.qlen--; + sch->flags &= ~TCQ_F_THROTTLED; + goto fin; + } + } + } + sch->qstats.overlimits++; + qdisc_watchdog_cancel(&q->watchdog); + qdisc_watchdog_schedule(&q->watchdog, next_event); +fin: + return skb; +} + +/* try to drop from each class (by prio) until one succeed */ +static unsigned int htb_drop(struct Qdisc *sch) +{ + struct htb_sched *q = qdisc_priv(sch); + int prio; + + for (prio = TC_HTB_NUMPRIO - 1; prio >= 0; prio--) { + struct list_head *p; + list_for_each(p, q->drops + prio) { + struct htb_class *cl = list_entry(p, struct htb_class, + un.leaf.drop_list); + unsigned int len; + if (cl->un.leaf.q->ops->drop && + (len = cl->un.leaf.q->ops->drop(cl->un.leaf.q))) { + sch->q.qlen--; + if (!cl->un.leaf.q->q.qlen) + htb_deactivate(q, cl); + return len; + } + } + } + return 0; +} + +/* reset all classes */ +/* always caled under BH & queue lock */ +static void htb_reset(struct Qdisc *sch) +{ + struct htb_sched *q = qdisc_priv(sch); + struct htb_class *cl; + struct hlist_node *n; + unsigned int i; + + for (i = 0; i < q->clhash.hashsize; i++) { + hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) { + if (cl->level) + memset(&cl->un.inner, 0, sizeof(cl->un.inner)); + else { + if (cl->un.leaf.q) + qdisc_reset(cl->un.leaf.q); + INIT_LIST_HEAD(&cl->un.leaf.drop_list); + } + cl->prio_activity = 0; + cl->cmode = HTB_CAN_SEND; + + } + } + qdisc_watchdog_cancel(&q->watchdog); + __skb_queue_purge(&q->direct_queue); + sch->q.qlen = 0; + memset(q->row, 0, sizeof(q->row)); + memset(q->row_mask, 0, sizeof(q->row_mask)); + memset(q->wait_pq, 0, sizeof(q->wait_pq)); + memset(q->ptr, 0, sizeof(q->ptr)); + for (i = 0; i < TC_HTB_NUMPRIO; i++) + INIT_LIST_HEAD(q->drops + i); +} + +static const struct nla_policy htb_policy[TCA_HTB_MAX + 1] = { + [TCA_HTB_PARMS] = { .len = sizeof(struct tc_htb_opt) }, + [TCA_HTB_INIT] = { .len = sizeof(struct tc_htb_glob) }, + [TCA_HTB_CTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE }, + [TCA_HTB_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE }, +}; + +static int htb_init(struct Qdisc *sch, struct nlattr *opt) +{ + struct htb_sched *q = qdisc_priv(sch); + struct nlattr *tb[TCA_HTB_INIT + 1]; + struct tc_htb_glob *gopt; + int err; + int i; + + if (!opt) + return -EINVAL; + + err = nla_parse_nested(tb, TCA_HTB_INIT, opt, htb_policy); + if (err < 0) + return err; + + if (tb[TCA_HTB_INIT] == NULL) { + printk(KERN_ERR "HTB: hey probably you have bad tc tool ?\n"); + return -EINVAL; + } + gopt = nla_data(tb[TCA_HTB_INIT]); + if (gopt->version != HTB_VER >> 16) { + printk(KERN_ERR + "HTB: need tc/htb version %d (minor is %d), you have %d\n", + HTB_VER >> 16, HTB_VER & 0xffff, gopt->version); + return -EINVAL; + } + + err = qdisc_class_hash_init(&q->clhash); + if (err < 0) + return err; + for (i = 0; i < TC_HTB_NUMPRIO; i++) + INIT_LIST_HEAD(q->drops + i); + + qdisc_watchdog_init(&q->watchdog, sch); + skb_queue_head_init(&q->direct_queue); + + q->direct_qlen = qdisc_dev(sch)->tx_queue_len; + if (q->direct_qlen < 2) /* some devices have zero tx_queue_len */ + q->direct_qlen = 2; + + if ((q->rate2quantum = gopt->rate2quantum) < 1) + q->rate2quantum = 1; + q->defcls = gopt->defcls; + + return 0; +} + +static int htb_dump(struct Qdisc *sch, struct sk_buff *skb) +{ + spinlock_t *root_lock = qdisc_root_sleeping_lock(sch); + struct htb_sched *q = qdisc_priv(sch); + struct nlattr *nest; + struct tc_htb_glob gopt; + + spin_lock_bh(root_lock); + + gopt.direct_pkts = q->direct_pkts; + gopt.version = HTB_VER; + gopt.rate2quantum = q->rate2quantum; + gopt.defcls = q->defcls; + gopt.debug = 0; + + nest = nla_nest_start(skb, TCA_OPTIONS); + if (nest == NULL) + goto nla_put_failure; + NLA_PUT(skb, TCA_HTB_INIT, sizeof(gopt), &gopt); + nla_nest_end(skb, nest); + + spin_unlock_bh(root_lock); + return skb->len; + +nla_put_failure: + spin_unlock_bh(root_lock); + nla_nest_cancel(skb, nest); + return -1; +} + +static int htb_dump_class(struct Qdisc *sch, unsigned long arg, + struct sk_buff *skb, struct tcmsg *tcm) +{ + struct htb_class *cl = (struct htb_class *)arg; + spinlock_t *root_lock = qdisc_root_sleeping_lock(sch); + struct nlattr *nest; + struct tc_htb_opt opt; + + spin_lock_bh(root_lock); + tcm->tcm_parent = cl->parent ? cl->parent->common.classid : TC_H_ROOT; + tcm->tcm_handle = cl->common.classid; + if (!cl->level && cl->un.leaf.q) + tcm->tcm_info = cl->un.leaf.q->handle; + + nest = nla_nest_start(skb, TCA_OPTIONS); + if (nest == NULL) + goto nla_put_failure; + + memset(&opt, 0, sizeof(opt)); + + opt.rate = cl->rate->rate; + opt.buffer = cl->buffer; + opt.ceil = cl->ceil->rate; + opt.cbuffer = cl->cbuffer; + opt.quantum = cl->un.leaf.quantum; + opt.prio = cl->un.leaf.prio; + opt.level = cl->level; + NLA_PUT(skb, TCA_HTB_PARMS, sizeof(opt), &opt); + + nla_nest_end(skb, nest); + spin_unlock_bh(root_lock); + return skb->len; + +nla_put_failure: + spin_unlock_bh(root_lock); + nla_nest_cancel(skb, nest); + return -1; +} + +static int +htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d) +{ + struct htb_class *cl = (struct htb_class *)arg; + + if (!cl->level && cl->un.leaf.q) + cl->qstats.qlen = cl->un.leaf.q->q.qlen; + cl->xstats.tokens = cl->tokens; + cl->xstats.ctokens = cl->ctokens; + + if (gnet_stats_copy_basic(d, &cl->bstats) < 0 || + gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 || + gnet_stats_copy_queue(d, &cl->qstats) < 0) + return -1; + + return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats)); +} + +static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, + struct Qdisc **old) +{ + struct htb_class *cl = (struct htb_class *)arg; + + if (cl && !cl->level) { + if (new == NULL && + (new = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue, + &pfifo_qdisc_ops, + cl->common.classid)) + == NULL) + return -ENOBUFS; + sch_tree_lock(sch); + if ((*old = xchg(&cl->un.leaf.q, new)) != NULL) { + qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); + qdisc_reset(*old); + } + sch_tree_unlock(sch); + return 0; + } + return -ENOENT; +} + +static struct Qdisc *htb_leaf(struct Qdisc *sch, unsigned long arg) +{ + struct htb_class *cl = (struct htb_class *)arg; + return (cl && !cl->level) ? cl->un.leaf.q : NULL; +} + +static void htb_qlen_notify(struct Qdisc *sch, unsigned long arg) +{ + struct htb_class *cl = (struct htb_class *)arg; + + if (cl->un.leaf.q->q.qlen == 0) + htb_deactivate(qdisc_priv(sch), cl); +} + +static unsigned long htb_get(struct Qdisc *sch, u32 classid) +{ + struct htb_class *cl = htb_find(classid, sch); + if (cl) + cl->refcnt++; + return (unsigned long)cl; +} + +static inline int htb_parent_last_child(struct htb_class *cl) +{ + if (!cl->parent) + /* the root class */ + return 0; + if (cl->parent->children > 1) + /* not the last child */ + return 0; + return 1; +} + +static void htb_parent_to_leaf(struct htb_sched *q, struct htb_class *cl, + struct Qdisc *new_q) +{ + struct htb_class *parent = cl->parent; + + WARN_ON(cl->level || !cl->un.leaf.q || cl->prio_activity); + + if (parent->cmode != HTB_CAN_SEND) + htb_safe_rb_erase(&parent->pq_node, q->wait_pq + parent->level); + + parent->level = 0; + memset(&parent->un.inner, 0, sizeof(parent->un.inner)); + INIT_LIST_HEAD(&parent->un.leaf.drop_list); + parent->un.leaf.q = new_q ? new_q : &noop_qdisc; + parent->un.leaf.quantum = parent->quantum; + parent->un.leaf.prio = parent->prio; + parent->tokens = parent->buffer; + parent->ctokens = parent->cbuffer; + parent->t_c = psched_get_time(); + parent->cmode = HTB_CAN_SEND; +} + +static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl) +{ + if (!cl->level) { + WARN_ON(!cl->un.leaf.q); + qdisc_destroy(cl->un.leaf.q); + } + gen_kill_estimator(&cl->bstats, &cl->rate_est); + qdisc_put_rtab(cl->rate); + qdisc_put_rtab(cl->ceil); + + tcf_destroy_chain(&cl->filter_list); + kfree(cl); +} + +/* always caled under BH & queue lock */ +static void htb_destroy(struct Qdisc *sch) +{ + struct htb_sched *q = qdisc_priv(sch); + struct hlist_node *n, *next; + struct htb_class *cl; + unsigned int i; + + qdisc_watchdog_cancel(&q->watchdog); + /* This line used to be after htb_destroy_class call below + and surprisingly it worked in 2.4. But it must precede it + because filter need its target class alive to be able to call + unbind_filter on it (without Oops). */ + tcf_destroy_chain(&q->filter_list); + + for (i = 0; i < q->clhash.hashsize; i++) { + hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) + tcf_destroy_chain(&cl->filter_list); + } + for (i = 0; i < q->clhash.hashsize; i++) { + hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[i], + common.hnode) + htb_destroy_class(sch, cl); + } + qdisc_class_hash_destroy(&q->clhash); + __skb_queue_purge(&q->direct_queue); +} + +static int htb_delete(struct Qdisc *sch, unsigned long arg) +{ + struct htb_sched *q = qdisc_priv(sch); + struct htb_class *cl = (struct htb_class *)arg; + unsigned int qlen; + struct Qdisc *new_q = NULL; + int last_child = 0; + + // TODO: why don't allow to delete subtree ? references ? does + // tc subsys quarantee us that in htb_destroy it holds no class + // refs so that we can remove children safely there ? + if (cl->children || cl->filter_cnt) + return -EBUSY; + + if (!cl->level && htb_parent_last_child(cl)) { + new_q = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue, + &pfifo_qdisc_ops, + cl->parent->common.classid); + last_child = 1; + } + + sch_tree_lock(sch); + + if (!cl->level) { + qlen = cl->un.leaf.q->q.qlen; + qdisc_reset(cl->un.leaf.q); + qdisc_tree_decrease_qlen(cl->un.leaf.q, qlen); + } + + /* delete from hash and active; remainder in destroy_class */ + qdisc_class_hash_remove(&q->clhash, &cl->common); + if (cl->parent) + cl->parent->children--; + + if (cl->prio_activity) + htb_deactivate(q, cl); + + if (cl->cmode != HTB_CAN_SEND) + htb_safe_rb_erase(&cl->pq_node, q->wait_pq + cl->level); + + if (last_child) + htb_parent_to_leaf(q, cl, new_q); + + if (--cl->refcnt == 0) + htb_destroy_class(sch, cl); + + sch_tree_unlock(sch); + return 0; +} + +static void htb_put(struct Qdisc *sch, unsigned long arg) +{ + struct htb_class *cl = (struct htb_class *)arg; + + if (--cl->refcnt == 0) + htb_destroy_class(sch, cl); +} + +static int htb_change_class(struct Qdisc *sch, u32 classid, + u32 parentid, struct nlattr **tca, + unsigned long *arg) +{ + int err = -EINVAL; + struct htb_sched *q = qdisc_priv(sch); + struct htb_class *cl = (struct htb_class *)*arg, *parent; + struct nlattr *opt = tca[TCA_OPTIONS]; + struct qdisc_rate_table *rtab = NULL, *ctab = NULL; + struct nlattr *tb[TCA_HTB_RTAB + 1]; + struct tc_htb_opt *hopt; + + /* extract all subattrs from opt attr */ + if (!opt) + goto failure; + + err = nla_parse_nested(tb, TCA_HTB_RTAB, opt, htb_policy); + if (err < 0) + goto failure; + + err = -EINVAL; + if (tb[TCA_HTB_PARMS] == NULL) + goto failure; + + parent = parentid == TC_H_ROOT ? NULL : htb_find(parentid, sch); + + hopt = nla_data(tb[TCA_HTB_PARMS]); + + rtab = qdisc_get_rtab(&hopt->rate, tb[TCA_HTB_RTAB]); + ctab = qdisc_get_rtab(&hopt->ceil, tb[TCA_HTB_CTAB]); + if (!rtab || !ctab) + goto failure; + + if (!cl) { /* new class */ + struct Qdisc *new_q; + int prio; + struct { + struct nlattr nla; + struct gnet_estimator opt; + } est = { + .nla = { + .nla_len = nla_attr_size(sizeof(est.opt)), + .nla_type = TCA_RATE, + }, + .opt = { + /* 4s interval, 16s averaging constant */ + .interval = 2, + .ewma_log = 2, + }, + }; + + /* check for valid classid */ + if (!classid || TC_H_MAJ(classid ^ sch->handle) + || htb_find(classid, sch)) + goto failure; + + /* check maximal depth */ + if (parent && parent->parent && parent->parent->level < 2) { + printk(KERN_ERR "htb: tree is too deep\n"); + goto failure; + } + err = -ENOBUFS; + if ((cl = kzalloc(sizeof(*cl), GFP_KERNEL)) == NULL) + goto failure; + + gen_new_estimator(&cl->bstats, &cl->rate_est, + qdisc_root_sleeping_lock(sch), + tca[TCA_RATE] ? : &est.nla); + cl->refcnt = 1; + cl->children = 0; + INIT_LIST_HEAD(&cl->un.leaf.drop_list); + RB_CLEAR_NODE(&cl->pq_node); + + for (prio = 0; prio < TC_HTB_NUMPRIO; prio++) + RB_CLEAR_NODE(&cl->node[prio]); + + /* create leaf qdisc early because it uses kmalloc(GFP_KERNEL) + so that can't be used inside of sch_tree_lock + -- thanks to Karlis Peisenieks */ + new_q = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue, + &pfifo_qdisc_ops, classid); + sch_tree_lock(sch); + if (parent && !parent->level) { + unsigned int qlen = parent->un.leaf.q->q.qlen; + + /* turn parent into inner node */ + qdisc_reset(parent->un.leaf.q); + qdisc_tree_decrease_qlen(parent->un.leaf.q, qlen); + qdisc_destroy(parent->un.leaf.q); + if (parent->prio_activity) + htb_deactivate(q, parent); + + /* remove from evt list because of level change */ + if (parent->cmode != HTB_CAN_SEND) { + htb_safe_rb_erase(&parent->pq_node, q->wait_pq); + parent->cmode = HTB_CAN_SEND; + } + parent->level = (parent->parent ? parent->parent->level + : TC_HTB_MAXDEPTH) - 1; + memset(&parent->un.inner, 0, sizeof(parent->un.inner)); + } + /* leaf (we) needs elementary qdisc */ + cl->un.leaf.q = new_q ? new_q : &noop_qdisc; + + cl->common.classid = classid; + cl->parent = parent; + + /* set class to be in HTB_CAN_SEND state */ + cl->tokens = hopt->buffer; + cl->ctokens = hopt->cbuffer; + cl->mbuffer = 60 * PSCHED_TICKS_PER_SEC; /* 1min */ + cl->t_c = psched_get_time(); + cl->cmode = HTB_CAN_SEND; + + /* attach to the hash list and parent's family */ + qdisc_class_hash_insert(&q->clhash, &cl->common); + if (parent) + parent->children++; + } else { + if (tca[TCA_RATE]) + gen_replace_estimator(&cl->bstats, &cl->rate_est, + qdisc_root_sleeping_lock(sch), + tca[TCA_RATE]); + sch_tree_lock(sch); + } + + /* it used to be a nasty bug here, we have to check that node + is really leaf before changing cl->un.leaf ! */ + if (!cl->level) { + cl->un.leaf.quantum = rtab->rate.rate / q->rate2quantum; + if (!hopt->quantum && cl->un.leaf.quantum < 1000) { + printk(KERN_WARNING + "HTB: quantum of class %X is small. Consider r2q change.\n", + cl->common.classid); + cl->un.leaf.quantum = 1000; + } + if (!hopt->quantum && cl->un.leaf.quantum > 200000) { + printk(KERN_WARNING + "HTB: quantum of class %X is big. Consider r2q change.\n", + cl->common.classid); + cl->un.leaf.quantum = 200000; + } + if (hopt->quantum) + cl->un.leaf.quantum = hopt->quantum; + if ((cl->un.leaf.prio = hopt->prio) >= TC_HTB_NUMPRIO) + cl->un.leaf.prio = TC_HTB_NUMPRIO - 1; + + /* backup for htb_parent_to_leaf */ + cl->quantum = cl->un.leaf.quantum; + cl->prio = cl->un.leaf.prio; + } + + cl->buffer = hopt->buffer; + cl->cbuffer = hopt->cbuffer; + if (cl->rate) + qdisc_put_rtab(cl->rate); + cl->rate = rtab; + if (cl->ceil) + qdisc_put_rtab(cl->ceil); + cl->ceil = ctab; + sch_tree_unlock(sch); + + qdisc_class_hash_grow(sch, &q->clhash); + + *arg = (unsigned long)cl; + return 0; + +failure: + if (rtab) + qdisc_put_rtab(rtab); + if (ctab) + qdisc_put_rtab(ctab); + return err; +} + +static struct tcf_proto **htb_find_tcf(struct Qdisc *sch, unsigned long arg) +{ + struct htb_sched *q = qdisc_priv(sch); + struct htb_class *cl = (struct htb_class *)arg; + struct tcf_proto **fl = cl ? &cl->filter_list : &q->filter_list; + + return fl; +} + +static unsigned long htb_bind_filter(struct Qdisc *sch, unsigned long parent, + u32 classid) +{ + struct htb_class *cl = htb_find(classid, sch); + + /*if (cl && !cl->level) return 0; + The line above used to be there to prevent attaching filters to + leaves. But at least tc_index filter uses this just to get class + for other reasons so that we have to allow for it. + ---- + 19.6.2002 As Werner explained it is ok - bind filter is just + another way to "lock" the class - unlike "get" this lock can + be broken by class during destroy IIUC. + */ + if (cl) + cl->filter_cnt++; + return (unsigned long)cl; +} + +static void htb_unbind_filter(struct Qdisc *sch, unsigned long arg) +{ + struct htb_class *cl = (struct htb_class *)arg; + + if (cl) + cl->filter_cnt--; +} + +static void htb_walk(struct Qdisc *sch, struct qdisc_walker *arg) +{ + struct htb_sched *q = qdisc_priv(sch); + struct htb_class *cl; + struct hlist_node *n; + unsigned int i; + + if (arg->stop) + return; + + for (i = 0; i < q->clhash.hashsize; i++) { + hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) { + if (arg->count < arg->skip) { + arg->count++; + continue; + } + if (arg->fn(sch, (unsigned long)cl, arg) < 0) { + arg->stop = 1; + return; + } + arg->count++; + } + } +} + +static const struct Qdisc_class_ops htb_class_ops = { + .graft = htb_graft, + .leaf = htb_leaf, + .qlen_notify = htb_qlen_notify, + .get = htb_get, + .put = htb_put, + .change = htb_change_class, + .delete = htb_delete, + .walk = htb_walk, + .tcf_chain = htb_find_tcf, + .bind_tcf = htb_bind_filter, + .unbind_tcf = htb_unbind_filter, + .dump = htb_dump_class, + .dump_stats = htb_dump_class_stats, +}; + +static struct Qdisc_ops htb_qdisc_ops __read_mostly = { + .next = NULL, + .cl_ops = &htb_class_ops, + .id = "htb", + .priv_size = sizeof(struct htb_sched), + .enqueue = htb_enqueue, + .dequeue = htb_dequeue, + .requeue = htb_requeue, + .drop = htb_drop, + .init = htb_init, + .reset = htb_reset, + .destroy = htb_destroy, + .change = NULL /* htb_change */, + .dump = htb_dump, + .owner = THIS_MODULE, +}; + +static int __init htb_module_init(void) +{ + return register_qdisc(&htb_qdisc_ops); +} +static void __exit htb_module_exit(void) +{ + unregister_qdisc(&htb_qdisc_ops); +} + +module_init(htb_module_init) +module_exit(htb_module_exit) +MODULE_LICENSE("GPL"); |
