First commit
diff --git a/util/sch_htb-ofbuf/Makefile b/util/sch_htb-ofbuf/Makefile
new file mode 100644
index 0000000..c4d714f
--- /dev/null
+++ b/util/sch_htb-ofbuf/Makefile
@@ -0,0 +1,11 @@
+obj-m = sch_htb.o
+KVERSION = $(shell uname -r)
+all:
+ make -C /lib/modules/$(KVERSION)/build M=$(PWD) modules
+install:
+ test -e /lib/modules/$(KVERSION)/kernel/net/sched/sch_htb.ko.bak || mv /lib/modules/$(KVERSION)/kernel/net/sched/sch_htb.ko /lib/modules/$(KVERSION)/kernel/net/sched/sch_htb.ko.bak
+ cp sch_htb.ko /lib/modules/$(KVERSION)/kernel/net/sched/sch_htb.ko
+ rmmod sch_htb
+ modprobe sch_htb
+clean:
+ make -C /lib/modules/$(KVERSION)/build M=$(PWD) clean
diff --git a/util/sch_htb-ofbuf/README b/util/sch_htb-ofbuf/README
new file mode 100644
index 0000000..711ed77
--- /dev/null
+++ b/util/sch_htb-ofbuf/README
@@ -0,0 +1,10 @@
+Modified sch_htb implementation with ofbuf support.
+
+To compile, just type make. To use this module instead
+of regular sch_htb, do:
+
+0. make
+1. rmmod sch_htb
+2. insmod ./sch_htb.ko
+
+To revert, just rmmod sch_htb.
diff --git a/util/sch_htb-ofbuf/sch_htb.c b/util/sch_htb-ofbuf/sch_htb.c
new file mode 100644
index 0000000..baead1c
--- /dev/null
+++ b/util/sch_htb-ofbuf/sch_htb.c
@@ -0,0 +1,1644 @@
+#define OFBUF (1)
+/*
+ * 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 <linux/workqueue.h>
+#include <linux/slab.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_packed 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 */
+
+ int prio; /* these two are used only by leaves... */
+ int quantum; /* but stored for parent-to-leaf return */
+
+ union {
+ struct htb_class_leaf {
+ struct Qdisc *q;
+ 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;
+
+ /* 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 */
+};
+
+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];
+
+ 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;
+
+#if OFBUF
+ /* overflow buffer */
+ struct sk_buff_head ofbuf;
+ int ofbuf_queued; /* # packets queued in above */
+#endif
+
+#define HTB_WARN_TOOMANYEVENTS 0x1
+ unsigned int warned; /* only one warning */
+ struct work_struct work;
+};
+
+/* 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 unsuccessful
+ * then finish and return direct queue.
+ */
+#define HTB_DIRECT ((struct htb_class *)-1L)
+
+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 */
+ cl = htb_find(skb->priority, sch);
+ if (cl && 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
+ cl = (void *)res.class;
+ if (!cl) {
+ if (res.classid == sch->handle)
+ return HTB_DIRECT; /* X:0 (direct flow) */
+ cl = htb_find(res.classid, sch);
+ if (!cl)
+ 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->prio;
+ htb_activate_prios(q, cl);
+ list_add_tail(&cl->un.leaf.drop_list,
+ q->drops + cl->prio);
+ }
+}
+
+/**
+ * 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 uninitialized_var(ret);
+ struct htb_sched *q = qdisc_priv(sch);
+ struct htb_class *cl = htb_classify(skb, sch, &ret);
+
+#if OFBUF
+ if(cl != HTB_DIRECT && cl)
+ skb_get(skb);
+#endif
+
+ 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) {
+ /* We shouldn't drop this, but enqueue it into ofbuf */
+ // TODO: is skb actually valid?
+ // Ans: looks like qdisc_enqueue will end up freeing the packet
+ // if enqueue failed. So we should incr refcnt before calling qdisc_enqueue...
+#if OFBUF
+ __skb_queue_tail(&q->ofbuf, skb);
+ q->ofbuf_queued++;
+#else
+ if (net_xmit_drop_count(ret)) {
+ sch->qstats.drops++;
+ cl->qstats.drops++;
+ }
+ return ret;
+#endif
+ } else {
+ bstats_update(&cl->bstats, skb);
+ htb_activate(q, cl);
+#if OFBUF
+ kfree_skb(skb);
+#endif
+ }
+
+ sch->q.qlen++;
+ return NET_XMIT_SUCCESS;
+}
+
+static inline void htb_accnt_tokens(struct htb_class *cl, int bytes, long diff)
+{
+ long toks = diff + cl->tokens;
+
+ if (toks > cl->buffer)
+ toks = cl->buffer;
+ toks -= (long) qdisc_l2t(cl->rate, bytes);
+ if (toks <= -cl->mbuffer)
+ toks = 1 - cl->mbuffer;
+
+ cl->tokens = toks;
+}
+
+static inline void htb_accnt_ctokens(struct htb_class *cl, int bytes, long diff)
+{
+ long toks = diff + cl->ctokens;
+
+ if (toks > cl->cbuffer)
+ toks = cl->cbuffer;
+ toks -= (long) qdisc_l2t(cl->ceil, bytes);
+ if (toks <= -cl->mbuffer)
+ toks = 1 - cl->mbuffer;
+
+ cl->ctokens = toks;
+}
+
+/**
+ * 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);
+ enum htb_cmode old_mode;
+ long diff;
+
+ 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(cl, bytes, diff);
+ } else {
+ cl->xstats.borrows++;
+ cl->tokens += diff; /* we moved t_c; update tokens */
+ }
+ htb_accnt_ctokens(cl, bytes, diff);
+ 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 basic stats except for leaves which are already updated */
+ if (cl->level)
+ bstats_update(&cl->bstats, skb);
+
+ 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, q->now for too many events).
+ * Note: Applied are events whose have cl->pq_key <= q->now.
+ */
+static psched_time_t htb_do_events(struct htb_sched *q, int level,
+ unsigned long start)
+{
+ /* 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 = start + 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 after a break for scheduling */
+ if (!(q->warned & HTB_WARN_TOOMANYEVENTS)) {
+ pr_warning("htb: too many events!\n");
+ q->warned |= HTB_WARN_TOOMANYEVENTS;
+ }
+
+ return q->now;
+}
+
+/* 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) {
+ n = n->rb_right;
+ } else if (id < cl->common.classid) {
+ r = n;
+ n = n->rb_left;
+ } else {
+ return n;
+ }
+ }
+ 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;
+
+ BUG_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--;
+ if (!*sp->pptr) {
+ WARN_ON(1);
+ 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:
+ if (unlikely(!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;
+
+ qdisc_warn_nonwc("htb", cl->un.leaf.q);
+ 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->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;
+ struct htb_sched *q = qdisc_priv(sch);
+ int level;
+ psched_time_t next_event;
+ unsigned long start_at;
+ u32 r, i;
+ struct sk_buff *pkt;
+
+ /* try to dequeue direct packets as high prio (!) to minimize cpu work */
+ skb = __skb_dequeue(&q->direct_queue);
+ if (skb != NULL) {
+ok:
+ qdisc_bstats_update(sch, skb);
+ qdisc_unthrottled(sch);
+ sch->q.qlen--;
+#if OFBUF
+ if(q->ofbuf_queued > 0) {
+ i = 0;
+ r = net_random() % q->ofbuf_queued;
+ // enqueue the rth packet and drop the rest
+ while((pkt = __skb_dequeue(&q->ofbuf)) != NULL) {
+ if(i == r) {
+ // the chosen one
+ htb_enqueue(pkt, sch);
+ } else {
+ kfree_skb(pkt);
+ }
+ i++;
+ }
+ q->ofbuf_queued = 0;
+ }
+#endif
+ return skb;
+ }
+
+ if (!sch->q.qlen)
+ goto fin;
+ q->now = psched_get_time();
+ start_at = jiffies;
+
+ next_event = q->now + 5 * PSCHED_TICKS_PER_SEC;
+
+ 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, start_at);
+ if (!event)
+ event = q->now + PSCHED_TICKS_PER_SEC;
+ q->near_ev_cache[level] = event;
+ } else
+ event = q->near_ev_cache[level];
+
+ if (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))
+ goto ok;
+ }
+ }
+ sch->qstats.overlimits++;
+ if (likely(next_event > q->now))
+ qdisc_watchdog_schedule(&q->watchdog, next_event);
+ else
+ schedule_work(&q->work);
+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;
+#if OFBUF
+ __skb_queue_purge(&q->ofbuf);
+ q->ofbuf_queued = 0;
+#endif
+ 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 void htb_work_func(struct work_struct *work)
+{
+ struct htb_sched *q = container_of(work, struct htb_sched, work);
+ struct Qdisc *sch = q->watchdog.qdisc;
+
+ __netif_schedule(qdisc_root(sch));
+}
+
+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) {
+ pr_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) {
+ pr_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);
+ INIT_WORK(&q->work, htb_work_func);
+ skb_queue_head_init(&q->direct_queue);
+
+#if OFBUF
+ skb_queue_head_init(&q->ofbuf);
+ q->ofbuf_queued = 0;
+#endif
+
+ 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->quantum;
+ opt.prio = cl->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, NULL, &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->level)
+ return -EINVAL;
+ if (new == NULL &&
+ (new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
+ cl->common.classid)) == NULL)
+ return -ENOBUFS;
+
+ sch_tree_lock(sch);
+ *old = cl->un.leaf.q;
+ cl->un.leaf.q = new;
+ if (*old != NULL) {
+ qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
+ qdisc_reset(*old);
+ }
+ sch_tree_unlock(sch);
+ return 0;
+}
+
+static struct Qdisc *htb_leaf(struct Qdisc *sch, unsigned long arg)
+{
+ struct htb_class *cl = (struct htb_class *)arg;
+ return !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->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);
+}
+
+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;
+
+ cancel_work_sync(&q->work);
+ 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);
+#if OFBUF
+ __skb_queue_purge(&q->ofbuf);
+ q->ofbuf_queued = 0;
+#endif
+}
+
+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(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);
+
+ BUG_ON(--cl->refcnt == 0);
+ /*
+ * This shouldn't happen: we "hold" one cops->get() when called
+ * from tc_ctl_tclass; the destroy method is done from cops->put().
+ */
+
+ 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_MAX];
+ struct tc_htb_opt *hopt;
+
+ /* extract all subattrs from opt attr */
+ if (!opt)
+ goto failure;
+
+ err = nla_parse_nested(tb, TCA_HTB_MAX, 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) {
+ pr_err("htb: tree is too deep\n");
+ goto failure;
+ }
+ err = -ENOBUFS;
+ cl = kzalloc(sizeof(*cl), GFP_KERNEL);
+ if (!cl)
+ goto failure;
+
+ err = gen_new_estimator(&cl->bstats, &cl->rate_est,
+ qdisc_root_sleeping_lock(sch),
+ tca[TCA_RATE] ? : &est.nla);
+ if (err) {
+ kfree(cl);
+ goto failure;
+ }
+
+ 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(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]) {
+ err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
+ qdisc_root_sleeping_lock(sch),
+ tca[TCA_RATE]);
+ if (err)
+ return err;
+ }
+ 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->quantum = rtab->rate.rate / q->rate2quantum;
+ if (!hopt->quantum && cl->quantum < 1000) {
+ pr_warning(
+ "HTB: quantum of class %X is small. Consider r2q change.\n",
+ cl->common.classid);
+ cl->quantum = 1000;
+ }
+ if (!hopt->quantum && cl->quantum > 200000) {
+ pr_warning(
+ "HTB: quantum of class %X is big. Consider r2q change.\n",
+ cl->common.classid);
+ cl->quantum = 200000;
+ }
+ if (hopt->quantum)
+ cl->quantum = hopt->quantum;
+ if ((cl->prio = hopt->prio) >= TC_HTB_NUMPRIO)
+ cl->prio = TC_HTB_NUMPRIO - 1;
+ }
+
+ 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 = {
+ .cl_ops = &htb_class_ops,
+ .id = "htb",
+ .priv_size = sizeof(struct htb_sched),
+ .enqueue = htb_enqueue,
+ .dequeue = htb_dequeue,
+ .peek = qdisc_peek_dequeued,
+ .drop = htb_drop,
+ .init = htb_init,
+ .reset = htb_reset,
+ .destroy = htb_destroy,
+ .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");